Sulfur dioxide exposure enhances Th2 inflammatory responses via activating STAT6 pathway in asthmatic mice.

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Sulfur dioxide exposure enhances Th2 inflammatory responses via activating STAT6 pathway in asthmatic mice.

Toxicol Lett. 2017 Dec 27;:

Authors: Li X, Huang L, Wang N, Yi H, Wang H

Abstract
Sulfur dioxide (SO2) is one of potential risk factors for induction and/or exacerbation of asthma, but the underlying mechanisms are not well understood. In this study, we investigate the role of SO2 in asthma using a classical asthmatic model with allergic airway inflammation by treating C57BL/6 mice with ovalbumin (OVA) and/or 10 mg/m3 SO2. Our results showed that SO2 exposure alone induced slight pathological changes but did not significantly increase inflammatory cell counts, pro-inflammatory cytokine expression, and mucus production in the airway of mice, whereas SO2 exposure in OVA-induced asthmatic mice caused marked pulmonary pathological changes and significantly increased the counts of eosinophil-rich leukocytes compared with OVA alone asthmatic mice. The expression of MUC5AC, TNF-α, Th2 cytokines (IL-4, IL-5, and IL-13) and STAT6 was further up-regulated in OVA plus SO2 treated mice compared with OVA alone treated mice. In addition, exposure to SO2 alone markedly elevated STAT6 mRNA levels and hydrogen peroxide (H2O2) content in the lung. These findings suggest that SO2 amplifies Th2 inflammatory responses in OVA-induced asthmatic mice by activating STAT6, which can further induce Th2 cytokine expression. Induction of STAT6 expression might be an important mechanism underlying the increased risk for asthma after environmental exposure.

PMID: 29288730 [PubMed - as supplied by publisher]

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The human papillomavirus E6 oncoprotein targets USP15 and TRIM25 to suppress RIG-I-mediated innate immune signaling.

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The human papillomavirus E6 oncoprotein targets USP15 and TRIM25 to suppress RIG-I-mediated innate immune signaling.

J Virol. 2017 Dec 20;:

Authors: Chiang C, Pauli EK, Biryukov J, Feister KF, Meng M, White EA, Münger K, Howley PM, Meyers C, Gack MU

Abstract
Retinoic acid-inducible gene-I (RIG-I) is a key pattern-recognition receptor that senses viral RNA and interacts with the mitochondrial adaptor MAVS, triggering a signaling cascade that results in the production of type I interferons (IFNs). This signaling axis is initiated by K63-linked ubiquitination of RIG-I mediated by the E3 ubiquitin ligase TRIM25, which promotes the interaction of RIG-I with MAVS. USP15 was recently identified as an upstream regulator of TRIM25 stabilizing the enzyme through removal of degradative K48-linked polyubiquitin, ultimately promoting RIG-I-dependent cytokine responses. Here we show that the E6 oncoprotein of human papillomavirus type 16 (HPV16) as well as of other HPV types form a complex with TRIM25 and USP15 in human cells. In the presence of E6, the K48-linked ubiquitination of TRIM25 was markedly increased, and in line with this, TRIM25 degradation was enhanced. Our results further showed that E6 inhibited the TRIM25-mediated K63-linked ubiquitination of RIG-I and its CARD-dependent interaction with MAVS. HPV16 E6, but not E7, suppressed the RIG-I-mediated induction of IFN-β, chemokines and IFN-stimulated genes (ISGs). Finally, CRISPR-Cas9 gene-targeting in human keratinocytes showed that the TRIM25-RIG-I-MAVS triad is important for eliciting an antiviral immune response to HPV16 infection. Our study thus identifies a novel immune escape mechanism that is conserved among different HPV strains, and further indicates that the RIG-I signaling pathway plays an important role in the innate immune response to HPV infection.IMPORTANCE Persistent infection and tumorigenesis by human papillomaviruses (HPVs) are known to require viral manipulation of a variety of cellular processes, including those involved in innate immune responses. Here we show that the HPV E6 oncoprotein antagonizes the activation of the cytoplasmic innate immune sensor RIG-I by targeting its upstream regulatory enzymes TRIM25 and USP15. We further show that the RIG-I signaling cascade is important for an antiviral innate immune response to HPV16 infection, providing evidence that RIG-I, whose role in sensing RNA virus infections has been well characterized, also plays a crucial role in the antiviral host response to small DNA viruses of the Papillomaviridae family.

PMID: 29263274 [PubMed - as supplied by publisher]

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Cytokine contributions to alterations of the volatile metabolome induced by inflammation.

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Cytokine contributions to alterations of the volatile metabolome induced by inflammation.

Brain Behav Immun. 2017 Dec 11;:

Authors: Millet P, Opiekun M, Martin T, Beauchamp GK, Kimball BA

Abstract
Several studies demonstrate that inflammation affects body odor. Volatile signals associated with inflammation induced by pyrogens like LPS are detectable both by conspecifics and chemical analyses. However, little is known about the mechanisms which translate detection of a foreign molecule or pathogen into a unique body odor, or even how unique that odor may be. Here, we utilized C57BL/6J trained mice to identify the odor of LPS-treated conspecifics to investigate potential pathways between LPS-induced inflammation and changes in body odor, as represented by changes in urine odor. We hypothesized that the change in volatile metabolites could be caused directly by the pro-inflammatory cytokine response mediated by TNF or IL-1β, or by the compensatory anti-inflammatory response mediated by IL-10. We found that trained biosensors generalized learned LPS-associated odors to TNF-induced odors, but not to IL-1β or IL-10-induced odors. Analyses of urine volatiles using headspace gas chromatography revealed distinct profiles of volatile compounds for each treatment. Instrumental discrimination relied on a mixture of compounds, including 2-sec-butyl-4,5-dihydrothiazole, cedrol, nonanal, benzaldehyde, acetic acid, 2-ethyl-1-hexanol, and dehydro-exo-brevicomin. Although interpretation of LDA modeling differed from behavioral testing, it does suggest that treatment with TNF, IL-1β, and LPS can be distinguished by their resultant volatile profiles. These findings indicate there is information found in body odors on the presence of specific cytokines. This result is encouraging for the future of disease diagnosis via analysis of volatiles.

PMID: 29241669 [PubMed - as supplied by publisher]

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Aging Decreases Chorda-Tympani Nerve Responses to NaCl and Alters Morphology of Fungiform Taste Pores in Rats.

Aging Decreases Chorda-Tympani Nerve Responses to NaCl and Alters Morphology of Fungiform Taste Pores in Rats.

Chem Senses. 2017 Dec 09;:

Authors: Whiddon ZD, Rynberg ST, Mast TG, Breza JM

Abstract
Sensory processing is susceptible to decline with age. The sense of taste is, however, generally thought to be resistant to aging. We investigated how chorda-tympani nerve responses and fungiform-taste pores are affected by aging in the Sprague-Dawley rat, a model system for salt taste. First, we measured chorda-tympani nerve responses to NH4Cl and NaCl solutions in young (3-5 months old) and aged (14-15 months old) rats. Aged rats had significantly attenuated chorda-tympani responses to 0.01, 0.03, 0.1, and 0.3M NaCl, whereas responses to NH4Cl were statistically similar between age groups. Second, we investigated if fungiform papillae, which harbor taste buds innervated by the chorda-tympani nerve, were affected by aging in "young" (4-7 months old) and "aged" ("aged1" 18 months old and "aged2" 24-28 months old) rats. Using scanning electron microscopy, we found that aging significantly reduced morphological characteristics associated with intact fungiform-taste pores (hillock, rim, pore presence, and open pore). We conclude that the structure and function of the peripheral-taste system may not be as resistant to aging as previously reported.

PMID: 29236959 [PubMed - as supplied by publisher]

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The intraparietal sulcus governs multisensory integration of audiovisual information based on task difficulty.

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The intraparietal sulcus governs multisensory integration of audiovisual information based on task difficulty.

Hum Brain Mapp. 2017 Dec 12;:

Authors: Regenbogen C, Seubert J, Johansson E, Finkelmeyer A, Andersson P, Lundström JN

Abstract
Object recognition benefits maximally from multimodal sensory input when stimulus presentation is noisy, or degraded. Whether this advantage can be attributed specifically to the extent of overlap in object-related information, or rather, to object-unspecific enhancement due to the mere presence of additional sensory stimulation, remains unclear. Further, the cortical processing differences driving increased multisensory integration (MSI) for degraded compared with clear information remain poorly understood. Here, two consecutive studies first compared behavioral benefits of audio-visual overlap of object-related information, relative to conditions where one channel carried information and the other carried noise. A hierarchical drift diffusion model indicated performance enhancement when auditory and visual object-related information was simultaneously present for degraded stimuli. A subsequent fMRI study revealed visual dominance on a behavioral and neural level for clear stimuli, while degraded stimulus processing was mainly characterized by activation of a frontoparietal multisensory network, including IPS. Connectivity analyses indicated that integration of degraded object-related information relied on IPS input, whereas clear stimuli were integrated through direct information exchange between visual and auditory sensory cortices. These results indicate that the inverse effectiveness observed for identification of degraded relative to clear objects in behavior and brain activation might be facilitated by selective recruitment of an executive cortical network which uses IPS as a relay mediating crossmodal sensory information exchange.

PMID: 29235185 [PubMed - as supplied by publisher]

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Biomimetic Sensors for the Senses: Towards Better Understanding of Taste and Odor Sensation.

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Biomimetic Sensors for the Senses: Towards Better Understanding of Taste and Odor Sensation.

Sensors (Basel). 2017 Dec 11;17(12):

Authors: Wu C, Du YW, Huang L, Ben-Shoshan Galeczki Y, Dagan-Wiener A, Naim M, Niv MY, Wang P

Abstract
Taste and smell are very important chemical senses that provide indispensable information on food quality, potential mates and potential danger. In recent decades, much progress has been achieved regarding the underlying molecular and cellular mechanisms of taste and odor senses. Recently, biosensors have been developed for detecting odorants and tastants as well as for studying ligand-receptor interactions. This review summarizes the currently available biosensing approaches, which can be classified into two main categories: in vitro and in vivo approaches. The former is based on utilizing biological components such as taste and olfactory tissues, cells and receptors, as sensitive elements. The latter is dependent on signals recorded from animals' signaling pathways using implanted microelectrodes into living animals. Advantages and disadvantages of these two approaches, as well as differences in terms of sensing principles and applications are highlighted. The main current challenges, future trends and prospects of research in biomimetic taste and odor sensors are discussed.

PMID: 29232897 [PubMed - in process]

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Where is the TMT? GC-MS analyses of fox feces and behavioral responses of rats to fear-inducing odors.

Where is the TMT? GC-MS analyses of fox feces and behavioral responses of rats to fear-inducing odors.

Chem Senses. 2017 Dec 08;:

Authors: Rampin O, Jerôme N, Saint-Albin A, Ouali C, Boué F, Meunier N, Nielsen BL

Abstract
TMT (2,5-dihydro-2,4,5-trimethylthiazoline) is known as a component of fox feces inducing fear in rodents. However, no recent chemical analyses of fox feces are available, and few studies make direct comparisons between TMT and fox feces. Fox feces from 3 individuals were used to prepare 24 samples to be analyzed for the presence of TMT using gas chromatography-mass spectrometry (GC-MS). When TMT was added in low amounts (50-2000 nmol/g), TMT was detected in 10 out of 11 samples. When no TMT was added, TMT was detected in only 1 out of 13 samples. In a second experiment, we tested the behavioral response of male Brown Norway (BN) and Wistar rats to either fox feces, a low amount of TMT (0.6 nmol) or 1-hexanol. TMT induced freezing in the rats, but fox feces induced significantly more freezing episodes and longer total duration of freezing in both rat strains. In experiment 3, male BN rats were exposed over several days to fox feces, rat feces, 1-hexanol, cadaverine, 2-phenylethylamine, and TMT, one odor at a time. Fox feces induced significantly more freezing episodes of a longer total duration than any of the other odors, with rat feces and 1-hexanol giving rise to the lowest amount of freezing. This finding, together with our inability to verify the presence of TMT in fox feces, indicates that the concentration of TMT in our fox feces samples was below 50 nmol/g. It may also be that other compounds in fox feces play a role in its fear-inducing properties.

PMID: 29228118 [PubMed - as supplied by publisher]

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Skn-1a/Pou2f3 functions as a master regulator to generate Trpm5-expressing chemosensory cells in mice.

Skn-1a/Pou2f3 functions as a master regulator to generate Trpm5-expressing chemosensory cells in mice.

PLoS One. 2017;12(12):e0189340

Authors: Yamashita J, Ohmoto M, Yamaguchi T, Matsumoto I, Hirota J

Abstract
Transient receptor potential channel M5 (Trpm5)-expressing cells, such as sweet, umami, and bitter taste cells in the oropharyngeal epithelium, solitary chemosensory cells in the nasal respiratory epithelium, and tuft cells in the small intestine, that express taste-related genes function as chemosensory cells. Previous studies demonstrated that Skn-1a/Pou2f3, a POU homeodomain transcription factor is expressed in these Trpm5-expressing chemosensory cells, and is necessary for their generation. Trpm5-expressing cells have recently been found in trachea, auditory tube, urethra, thymus, pancreatic duct, stomach, and large intestine. They are considered to be involved in protective responses to potential hazardous compounds as Skn-1a-dependent bitter taste cells, respiratory solitary chemosensory cells, and intestinal tuft cells are. In this study, we examined the expression and function of Skn-1a/Pou2f3 in Trpm5-expressing cells in trachea, auditory tube, urethra, thymus, pancreatic duct, stomach, and large intestine. Skn-1a/Pou2f3 is expressed in a majority of Trpm5-expressing cells in all tissues examined. In Skn-1a/Pou2f3-deficient mice, the expression of Trpm5 as well as marker genes for Trpm5-expressing cells were absent in all tested tissues. Immunohistochemical analyses demonstrated that two types of microvillous cells exist in trachea, urethra, and thymus, Trpm5-positive and Trpm5-negative cells. In Skn-1a/Pou2f3-deficient mice, a considerable proportion of Trpm5-negative and villin-positive microvillous cells remained present in these tissues. Thus, we propose that Skn-1a/Pou2f3 is the master regulator for the generation of the Trpm5-expressing microvillous cells in multiple tissues.

PMID: 29216297 [PubMed - in process]

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Effect of Ovarian Hormones and Mating Experience on the Preference of Female Mice to Investigate Male Urinary Pheromones.

Effect of Ovarian Hormones and Mating Experience on the Preference of Female Mice to Investigate Male Urinary Pheromones.

Chem Senses. 2017 Dec 02;:

Authors: McCarthy EA, Naik AS, Coyne AF, Cherry JA, Baum MJ

Abstract
In female mice the expression of receptive lordosis behavior requires estradiol and progesterone actions in the nervous system; however, the contribution of these hormones to females' motivation to seek out male pheromones is less clear. In an initial experiment, sexually naïve ovary-intact female mice preferred to investigate (make nasal contact with) testes-intact male as opposed to estrous female urine, provided they were in vaginal estrus. In a second experiment, groups of sexually naïve and mating-experienced, ovariectomized females were tested for urinary pheromone preference first without and then with ovarian hormone replacement. Without hormone replacement, sexually naïve ovariectomized females showed no preference for male over female urinary pheromones whereas mating-experienced females preferred to investigate male pheromones. Ovariectomized females in both groups preferred male over female urine after sequential s.c. injections with estradiol benzoate followed 2 days later with progesterone and after prolonged (7 days) exposure to estradiol alone. Our results indicate that in sexually naïve female mice estradiol, perhaps aided by progesterone, is required to motivate a preference to seek out male pheromones whereas after mating experience females' preference to investigate male pheromones persists even in the absence of ovarian hormone action.

PMID: 29211837 [PubMed - as supplied by publisher]

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A workshop on 'Dietary sweetness-Is it an issue?'

A workshop on 'Dietary sweetness-Is it an issue?'

Int J Obes (Lond). 2017 Dec 06;:

Authors: Wittekind A, Higgins K, McGale L, Schwartz C, Stamataki NS, Beauchamp GK, Bonnema A, Dussort P, Gibson S, de Graaf C, Halford JCG, Marsaux CFM, Mattes RD, McLaughlin J, Mela DJ, Nicklaus S, Rogers PJ, Macdonald IA

Abstract
This report summarises a workshop convened by ILSI Europe on 3rd and 4th April 2017 to discuss the issue of dietary sweetness. The objectives were to understand the roles of sweetness in the diet; establish whether exposure to sweetness affects diet quality and energy intake; and consider whether sweetness per se affects health. Although there may be evidence for tracking of intake of some sweet components of the diet through childhood, evidence for tracking of whole diet sweetness, or through other stages of maturity are lacking. The evidence to date does not support adverse effects of sweetness on diet quality or energy intake, except where sweet food choices increase intake of free sugars. There is some evidence for improvements in diet quality and reduced energy intake where sweetness without calories replaces sweetness with calories. There is a need to understand the physiological and metabolic relevance of sweet taste receptors on the tongue, in the gut and elsewhere in the body, as well as possible differentiation in the effects of sustained consumption of individual sweeteners. Despite a plethora of studies, there is no consistent evidence for an association of sweetness sensitivity/preference with obesity or type 2 diabetes. A multifaceted integrated approach, characterising nutritive and sensory aspects of the whole diet or dietary patterns, may be more valuable in providing contextual insight. The outcomes of the workshop could be used as a scientific basis to inform the expert community and create more useful dialogue among health care professionals.International Journal of Obesity accepted article preview online, 06 December 2017. doi:10.1038/ijo.2017.296.

PMID: 29211705 [PubMed - as supplied by publisher]

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Adiposity QTL Adip20 decomposes into at least four loci when dissected using congenic strains.

Adiposity QTL Adip20 decomposes into at least four loci when dissected using congenic strains.

PLoS One. 2017;12(12):e0188972

Authors: Lin C, Fesi BD, Marquis M, Bosak NP, Lysenko A, Koshnevisan MA, Duke FF, Theodorides ML, Nelson TM, McDaniel AH, Avigdor M, Arayata CJ, Shaw L, Bachmanov AA, Reed DR

Abstract
An average mouse in midlife weighs between 25 and 30 g, with about a gram of tissue in the largest adipose depot (gonadal), and the weight of this depot differs between inbred strains. Specifically, C57BL/6ByJ mice have heavier gonadal depots on average than do 129P3/J mice. To understand the genetic contributions to this trait, we mapped several quantitative trait loci (QTLs) for gonadal depot weight in an F2 intercross population. Our goal here was to fine-map one of these QTLs, Adip20 (formerly Adip5), on mouse chromosome 9. To that end, we analyzed the weight of the gonadal adipose depot from newly created congenic strains. Results from the sequential comparison method indicated at least four rather than one QTL; two of the QTLs were less than 0.5 Mb apart, with opposing directions of allelic effect. Different types of evidence (missense and regulatory genetic variation, human adiposity/body mass index orthologues, and differential gene expression) implicated numerous candidate genes from the four QTL regions. These results highlight the value of mouse congenic strains and the value of this sequential method to dissect challenging genetic architecture.

PMID: 29194435 [PubMed - in process]

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Taste Responses to Linoleic Acid: A Crowdsourced Population Study.

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Taste Responses to Linoleic Acid: A Crowdsourced Population Study.

Chem Senses. 2017 Oct 31;42(9):769-775

Authors: Garneau NL, Nuessle TM, Tucker RM, Yao M, Santorico SA, Mattes RD, Genetics of Taste Lab Citizen Scientists

Abstract
Dietary fats serve multiple essential roles in human health but may also contribute to acute and chronic health complications. Thus, understanding mechanisms that influence fat ingestion are critical. All sensory systems may contribute relevant cues to fat detection, with the most recent evidence supporting a role for the sense of taste. Taste detection thresholds for fat vary markedly between individuals and responses are not normally distributed. Genetics may contribute to these observations. Using crowdsourced data obtained from families visiting the Denver Museum of Nature & Science, our objective was to estimate the heritability of fat taste (oleogustus). A pedigree analysis was conducted with 106 families (643 individuals) who rated the fat taste intensity of graded concentrations of linoleic acid (LA) embedded in taste strips. The findings estimate that 19% (P = 0.043) of the variability of taste response to LA relative to baseline is heritable at the highest concentration tested.

PMID: 28968903 [PubMed - indexed for MEDLINE]

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Cognitive Load Alters Neuronal Processing of Food Odors.

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Cognitive Load Alters Neuronal Processing of Food Odors.

Chem Senses. 2017 Oct 31;42(9):723-736

Authors: Hoffmann-Hensel SM, Sijben R, Rodriguez-Raecke R, Freiherr J

Abstract
Obesity is a major health concern in modern societies. Although decreased physical activity and enhanced intake of high-caloric foods are important risk factors for developing obesity, human behavior during eating also plays a role. Previous studies have shown that distraction while eating increases food intake and leads to impaired processing of food stimuli. As olfaction is the most important sense involved in flavor perception, we used functional magnetic resonance imaging techniques to investigate the influence of cognitive memory load on olfactory perception and processing. Low- and high-caloric food odors were presented in combination with either low or high cognitive loads utilizing a memory task. The efficacy of the memory task was verified by a decrease in participant recall accuracy and an increase in skin conductance response during high cognitive load. Our behavioral data reveal a diminished perceived intensity for low- but not high-caloric food odors during high cognitive load. For low-caloric food odors, bilateral orbitofrontal (OFC) and piriform cortices (pirC) showed significantly lower activity during high compared with low cognitive load. For high-caloric food odors, a similar effect was established in pirC, but not in OFC. Insula activity correlates with higher intensity ratings found during the low cognitive load condition. We conclude lower activity in pirC and OFC to be responsible for diminished intensity perception, comparable to results in olfactory impaired patients and elderly. Further studies should investigate the influence of olfactory/gustatory intensities on food choices under distraction with special regards to low-caloric food.

PMID: 28968851 [PubMed - indexed for MEDLINE]

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The Accessory Olfactory System Facilitates the Recovery of the Attraction to Familiar Volatile Female Odors in Male Mice.

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The Accessory Olfactory System Facilitates the Recovery of the Attraction to Familiar Volatile Female Odors in Male Mice.

Chem Senses. 2017 Oct 31;42(9):737-745

Authors: Muroi Y, Nishimura M, Ishii T

Abstract
Odors in female mice induce sexual arousal in male mice. Repeated exposure to female odors attenuates male attraction, which recovers when the odors are removed. The neuronal mechanisms for the recovery of male attraction have not been clarified. In this study, we examined how olfactory systems are involved in the recovery of male attraction to female odors following habituation in mice. Presentation with volatile female odors for 5 min induced habituation in males. To evaluate male attraction to familiar volatile female odors, we measured the duration for investigating volatile female odors from the same female mouse, which was presented twice for 5 min with 1-, 3-, or 5-min interval. Intranasal irrigation with ZnSO4 solution almost completely suppressed investigating behavior, indicating that the main olfactory system is indispensable for inducing the attraction to volatile female odors. In contrast, removal of the vomeronasal organ, bilateral lesions of the accessory olfactory bulb (AOB), or pharmacological blockage of neurotransmission in the AOB did not affect the investigation time at the first odor presentation. However, each one of the treatments decreased the investigation time in the second presentation, compared to that in the first presentation, at longer intervals than control treatment, indicating that the disturbance of neurotransmission in the accessory olfactory system delayed the recovery of the attraction attenuated by the first presentation. These results suggest that the accessory olfactory system facilitates the recovery of the attraction to familiar volatile female odors in male mice.

PMID: 28968801 [PubMed - indexed for MEDLINE]

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Olfactory Context-Dependent Memory and the Effects of Affective Congruency.

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Olfactory Context-Dependent Memory and the Effects of Affective Congruency.

Chem Senses. 2017 Oct 31;42(9):777-788

Authors: Hackländer RPM, Bermeitinger C

Abstract
Odors have been claimed to be particularly effective mnemonic cues, possibly because of the strong links between olfaction and emotion processing. Indeed, past research has shown that odors can bias processing towards affectively congruent material. In order to determine whether this processing bias translates to memory, we conducted 2 olfactory-enhanced-context memory experiments where we manipulated affective congruency between the olfactory context and to-be-remembered material. Given the presumed importance of valence to olfactory perception, we hypothesized that memory would be best for affectively congruent material in the olfactory enhanced context groups. Across the 2 experiments, groups which encoded and retrieved material in the presence of an odorant exhibited better memory performance than groups that did not have the added olfactory context during encoding and retrieval. While context-enhanced memory was exhibited in the presence of both pleasant and unpleasant odors, there was no indication that memory was dependent on affective congruency between the olfactory context and the to-be-remembered material. While the results provide further support for the notion that odors can act as powerful contextual mnemonic cues, they call into question the notion that affective congruency between context and focal material is important for later memory performance.

PMID: 28968744 [PubMed - indexed for MEDLINE]

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Type III Cells in Anterior Taste Fields Are More Immunohistochemically Diverse Than Those of Posterior Taste Fields in Mice.

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Type III Cells in Anterior Taste Fields Are More Immunohistochemically Diverse Than Those of Posterior Taste Fields in Mice.

Chem Senses. 2017 Oct 31;42(9):759-767

Authors: Wilson CE, Finger TE, Kinnamon SC

Abstract
Activation of Type III cells in mammalian taste buds is implicated in the transduction of acids (sour) and salty stimuli. Several lines of evidence suggest that function of Type III cells in the anterior taste fields may differ from that of Type III cells in posterior taste fields. Underlying anatomy to support this observation is, however, scant. Most existing immunohistochemical data characterizing this cell type focus on circumvallate taste buds in the posterior tongue. Equivalent data from anterior taste fields-fungiform papillae and soft palate-are lacking. Here, we compare Type III cells in four taste fields: fungiform, soft palate, circumvallate, and foliate in terms of reactivity to four canonical markers of Type III cells: polycystic kidney disease 2-like 1 (PKD2L1), synaptosomal associated protein 25 (SNAP25), serotonin (5-HT), and glutamate decarboxylase 67 (GAD67). Our findings indicate that while PKD2L1, 5-HT, and SNAP25 are highly coincident in posterior taste fields, they diverge in anterior taste fields. In particular, a subset of taste cells expresses PKD2L1 without the synaptic markers, and a subset of SNAP25 cells lacks expression of PKD2L1. In posterior taste fields, GAD67-positive cells are a subset of PKD2L1 expressing taste cells, but anterior taste fields also contain a significant population of GAD67-only expressing cells. These differences in expression patterns may underlie the observed functional differences between anterior and posterior taste fields.

PMID: 28968659 [PubMed - indexed for MEDLINE]

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Influence of airflow rate and stimulus concentration on olfactory event-related potentials (OERP) in humans.

Influence of airflow rate and stimulus concentration on olfactory event-related potentials (OERP) in humans.

Chem Senses. 2017 Nov 14;:

Authors: Han P, Schriever VA, Peters P, Olze H, Uecker FC, Hummel T

Abstract
Although the association between odor concentration and olfactory event-related potential (OERP) has been studied, less is known about the influence of airflow on OERP. The aim of this study was to investigate the influence of airflow rate and stimulus concentration on OERP in humans. EEG data were collected from young healthy volunteers (n=17) in separate sessions where 2-phenylethanol (PEA) was delivered in the following conditions: 8L/min 50%v/v, 8L/min 30%v/v, 4L/min 100%v/v and 4L/min 60%v/v. Odor concentrations are referred to the %v/v achieved with air dilution and was not measured in the nose. Odor intensity ratings were recorded immediately after stimulus presentation. Data recorded at five electrodes (Fz, Cz, Pz, C3 and C4) were pooled and analyzed using both time domain averaging and single-trial time-frequency domain approaches. Higher airflow rate significantly increased intensity ratings (F=10.98, p<0.01), and improved the signal-to-noise-ratio (F=5.42, p=0.025). Results from time-frequency analysis showed higher concentration vs. lower concentration increased brain oscillations in the slow frequency band (1-3 Hz) at 0-600 ms; while higher airflow rates vs. lower airflow rate increased theta-band oscillations (300-600 ms and 5-9 Hz) and decreased delta-band oscillations at 900-1500ms after stimulus onset. In conclusion, compared to stimulus concentration, airflow rate was associated with improved OERP quality and more pronounced responses. The results suggest that intensity ratings and OERP are strongly related to the steepness of stimulus onset. High airflow rates are suggested for odor delivery in order to record OERP.

PMID: 29145567 [PubMed - as supplied by publisher]

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Primary Cilium-Dependent Signaling Mechanisms.

Primary Cilium-Dependent Signaling Mechanisms.

Int J Mol Sci. 2017 Oct 28;18(11):

Authors: Pala R, Alomari N, Nauli SM

Abstract
Primary cilia are hair-like organelles and play crucial roles in vertebrate development, organogenesis, health, and many genetic disorders. A primary cilium is a mechano-sensory organelle that responds to mechanical stimuli in the micro-environment. A cilium is also a chemosensor that senses chemical signals surrounding a cell. The overall function of a cilium is therefore to act as a communication hub to transfer extracellular signals into intracellular responses. Although intracellular calcium has been one of the most studied signaling messengers that transmit extracellular signals into the cells, calcium signaling by various ion channels remains a topic of interest in the field. This may be due to a broad spectrum of cilia functions that are dependent on or independent of utilizing calcium as a second messenger. We therefore revisit and discuss the calcium-dependent and calcium-independent ciliary signaling pathways of Hedgehog, Wnt, PDGFR, Notch, TGF-β, mTOR, OFD1 autophagy, and other GPCR-associated signaling. All of these signaling pathways play crucial roles in various cellular processes, such as in organ and embryonic development, cardiac functioning, planar cell polarity, transactivation, differentiation, the cell cycle, apoptosis, tissue homeostasis, and the immune response.

PMID: 29143784 [PubMed - in process]

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Differences in Taste Perception and Spicy Preference: a Thai - Japanese Cross-cultural Study.

Differences in Taste Perception and Spicy Preference: a Thai - Japanese Cross-cultural Study.

Chem Senses. 2017 Nov 09;:

Authors: Trachootham D, Sato-Kuriwada S, Lam-Ubol A, Promkam C, Chotechuang N, Sasano T, Shoji N

Abstract
Taste perception is influenced by several factors. However, the relation between taste perception and food culture is unclear. This study compared taste thresholds between populations with different food culture, i.e. Thai and Japanese. A matched case-control study was conducted in 168 adults (84 for each; aged between 50-90 years). The age, sex, systemic disease, medication, smoking, xerostomia and oral hygiene of both groups were not different. Recognition thresholds of sweet, salty, sour, bitter and umami were measured using filter paper disc (FPD). Detection taste thresholds were measured using electrogustometry. Spicy preference was measured by calibrated questionnaires. Higher recognition thresholds of all tastes and higher detection taste thresholds were found in Thai as compared to those of Japanese (p<0.0001). Separate analyses of healthy and unhealthy persons confirmed the significant differences between two countries. The average thresholds for sweet, salty, sour and bitter in Thai and Japanese were 4 and 2, respectively. The average threshold for umami in Thai and Japanese was 5 and 3, respectively. Moreover, Thai population had stronger preference for spicy food (p<0.0001) with 70% mild- or moderate and 10% strong lovers, compared to over 90% non- or mild-spicy lovers in Japanese. In addition, 70% of Thai consumed spicy food weekly, whilst 80% of Japanese consumed it monthly. Our findings suggested that population with stronger spicy preference such as Thai had much poorer taste sensitivity and perception than that with milder preference like Japanese. Extensive international survey is needed to conclude the influence of food culture on taste perception.

PMID: 29136162 [PubMed - as supplied by publisher]

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In vivo bioelectronic nose using transgenic mice for specific odor detection.

In vivo bioelectronic nose using transgenic mice for specific odor detection.

Biosens Bioelectron. 2017 Oct 10;102:150-156

Authors: Gao K, Li S, Zhuang L, Qin Z, Zhang B, Huang L, Wang P

Abstract
The olfactory system is a natural biosensor since its peripheral olfactory sensory neurons (OSNs) respond to the external stimuli and transmit the signals to the olfactory bulb (OB) where they are integrated and processed. The axonal connections from the OSNs expressing about 1000 different types of odorant receptors are precisely organized and sorted out onto 1800 glomeruli in the OB, from which the olfactory information is delivered to and perceived by the central nervous system. This process is carried out with particularly high sensitivity, specificity and rapidity, which can be used for explosive detection. Biomimetic olfactory biosensors use various biological components from the olfactory system as sensing elements, possessing great commercial prospects. In this study, we utilized the genetically labeled murine M72 olfactory sensory neurons with the green fluorescent protein (GFP) as sensing components and obtained long-term in vivo electrophysiological recordings from the M72 OSNs by implanting the microelectrode arrays (MEAs) into the behaving mouse's OB. The electrophysiological responses showed high reliability, reproducibility and specificity for odor detection, and particularly, the high sensitivity for the detection of odorants that contain benzene rings. Furthermore, our results indicated that it can detect trinitrotoluene (TNT) in liquid at a concentration as low as 10(-5)M and can distinguish TNT from other chemicals with a similar structure. Thus our study demonstrated that the in vivo biomimetic olfactory system could provide novel approaches to enhancing the specificity and increasing working lifespan of olfactory biosensors capable of detecting explosives.

PMID: 29128717 [PubMed - as supplied by publisher]

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The association between diabetes and olfactory function in adults.

The association between diabetes and olfactory function in adults.

Chem Senses. 2017 Nov 08;:

Authors: Chan JYK, García-Esquinas E, Ko OH, Tong MCF, Lin SY

Abstract
Diabetes is a significant chronic disease that in limited studies has been linked with olfactory dysfunction. We investigated the cross-sectional association between diabetes and olfactory dysfunction in 3,151 adults aged ≥40 years who participated in NHANES 2013-2014 with information on olfactory dysfunction and diabetes. Diabetes was defined from fasting serum glucose ≥126 mg/dl, oral glucose tolerance test ≥200 mg/dl, HbA1c levels ≥6.5%, physician-diagnosed diabetes, or current use of oral hypoglycemic agents and/or insulin. Self-reported olfactory dysfunction was defined as a positive answer to any of the following questions: 1) "Have you had problem with smell in the past 12 months?"; 2) "Have you had a change in the ability to smell since age 25?", or 3) "Do you have phantom smells?". Participants were considered to have severe hyposmia or anosmia if they had <5 correct answers in the 8-item pocket smell test. Analyses were adjusted for the main confounders, including olfactory dysfunction risk factors. Compared to non-diabetics, diabetics under insulin treatment showed a higher prevalence of phantom odors (OR(95%CI): 2.42 (1.16; 5.06)) and a non- significant higher prevalence of severe hyposmia/anosmia (OR(95%CI): 1.57 (0.89; 2.78)). Amongst diabetics, there was a significant trend to severe hyposmia/anosmia for those on more aggressive treatments (OR (95%CI) including oral and insulin treatment compared to those who reported no use of drug treatment, respectively: 1.33 (0.60; 2.96) and 2.86 (1.28; 6.40); p trend 0.01. No association was observed between diabetes duration and prevalence of olfactory dysfunction.

PMID: 29126164 [PubMed - as supplied by publisher]

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Characterization of Whole Grain Pasta: Integrating Physical, Chemical, Molecular, and Instrumental Sensory Approaches.

Characterization of Whole Grain Pasta: Integrating Physical, Chemical, Molecular, and Instrumental Sensory Approaches.

J Food Sci. 2017 Nov;82(11):2583-2590

Authors: Marti A, Cattaneo S, Benedetti S, Buratti S, Abbasi Parizad P, Masotti F, Iametti S, Pagani MA

Abstract
The consumption of whole-grain food-including pasta-has been increasing steadily. In the case of whole-grain pasta, given the many different producers, it seems important to have some objective parameters to define its overall quality. In this study, commercial whole-grain pasta samples representative of the Italian market have been characterized from both molecular and electronic-senses (electronic nose and electronic tongue) standpoint in order to provide a survey of the properties of different commercial samples. Only 1 pasta product showed very low levels of heat damage markers (furosine and pyrraline), suggesting that this sample underwent to low temperature dry treatment. In all samples, the furosine content was directly correlated to protein structural indices, since protein structure compactness increased with increasing levels of heat damage markers. Electronic senses were able to discriminate among pasta samples according to the intensity of heat treatment during the drying step. Pasta sample with low furosine content was discriminated by umami taste and by sensors responding to aliphatic and inorganic compounds. Data obtained with this multidisciplinary approach are meant to provide hints for identifying useful indices for pasta quality.
PRACTICAL APPLICATION: As observed for semolina pasta, objective parameters based on heat-damage were best suited to define the overall quality of wholegrain pasta, almost independently of compositional differences among commercial samples. Drying treatments of different intensity also had an impact on instrumental sensory traits that may provide a reliable alternative to analytical determination of chemical markers of heat damage in all cases where there is a need for avoiding time-consuming procedures.

PMID: 29125640 [PubMed - in process]

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An Investigation into Spike-Based Neuromorphic Approaches for Artificial Olfactory Systems.

An Investigation into Spike-Based Neuromorphic Approaches for Artificial Olfactory Systems.

Sensors (Basel). 2017 Nov 10;17(11):

Authors: Vanarse A, Osseiran A, Rassau A

Abstract
The implementation of neuromorphic methods has delivered promising results for vision and auditory sensors. These methods focus on mimicking the neuro-biological architecture to generate and process spike-based information with minimal power consumption. With increasing interest in developing low-power and robust chemical sensors, the application of neuromorphic engineering concepts for electronic noses has provided an impetus for research focusing on improving these instruments. While conventional e-noses apply computationally expensive and power-consuming data-processing strategies, neuromorphic olfactory sensors implement the biological olfaction principles found in humans and insects to simplify the handling of multivariate sensory data by generating and processing spike-based information. Over the last decade, research on neuromorphic olfaction has established the capability of these sensors to tackle problems that plague the current e-nose implementations such as drift, response time, portability, power consumption and size. This article brings together the key contributions in neuromorphic olfaction and identifies future research directions to develop near-real-time olfactory sensors that can be implemented for a range of applications such as biosecurity and environmental monitoring. Furthermore, we aim to expose the computational parallels between neuromorphic olfaction and gustation for future research focusing on the correlation of these senses.

PMID: 29125586 [PubMed - in process]

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Chemotaxis to self-generated AI-2 promotes biofilm formation in Escherichia coli.

Chemotaxis to self-generated AI-2 promotes biofilm formation in Escherichia coli.

Microbiology. 2017 Nov 09;:

Authors: Jani S, Seely AL, Peabody V GL, Jayaraman A, Manson MD

Abstract
Responses to the interspecies quorum-sensing signal autoinducer-2 (AI-2) regulate the patterns of gene expression that promote biofilm development. Escherichia coli also senses AI-2 as a chemoattractant, a response that requires the periplasmic AI-2-binding protein LsrB and the chemoreceptor Tsr. Here, we confirm, as previously observed, that under static conditions highly motile E. coli cells self-aggregate and form surface-adherent structures more readily than cells lacking LsrB and Tsr, or than ΔluxS cells unable to produce AI-2. This difference is observed both at 37 and 30 °C. Cells deleted for the genes encoding the lsrACDBFG operon repressor (ΔlsrR), or the AI-2 kinase (ΔlsrK), or an AI-2 uptake channel protein (ΔlsrC), or an AI-2 metabolism enzyme (ΔlsrG) are also defective in biofilm formation. The Δtsr and ΔlsrB cells are totally defective in AI-2 chemotaxis, whereas the other mutants show normal or near-normal chemotaxis to external gradients of AI-2. These data demonstrate that chemotaxis to external AI-2 is necessary but not sufficient to induce the full range of density-dependent behaviours that are required for optimal biofilm formation. We also demonstrate that, compared to other binding-protein-dependent chemotaxis systems in E. coli, low levels (on the order of ~250 molecules of periplasmic LsrB per wild-type cell and as low as ~50 molecules per cell in some mutants) are adequate for a strong chemotaxis response to external gradients of AI-2.

PMID: 29125461 [PubMed - as supplied by publisher]

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Cell-to-cell variation sets a tissue-rheology-dependent bound on collective gradient sensing.

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Cell-to-cell variation sets a tissue-rheology-dependent bound on collective gradient sensing.

Proc Natl Acad Sci U S A. 2017 Nov 07;:

Authors: Camley BA, Rappel WJ

Abstract
When a single cell senses a chemical gradient and chemotaxes, stochastic receptor-ligand binding can be a fundamental limit to the cell's accuracy. For clusters of cells responding to gradients, however, there is a critical difference: Even genetically identical cells have differing responses to chemical signals. With theory and simulation, we show collective chemotaxis is limited by cell-to-cell variation in signaling. We find that when different cells cooperate, the resulting bias can be much larger than the effects of ligand-receptor binding. Specifically, when a strongly responding cell is at one end of a cell cluster, cluster motion is biased toward that cell. These errors are mitigated if clusters average measurements over times long enough for cells to rearrange. In consequence, fluid clusters are better able to sense gradients: We derive a link between cluster accuracy, cell-to-cell variation, and the cluster rheology. Because of this connection, increasing the noisiness of individual cell motion can actually increase the collective accuracy of a cluster by improving fluidity.

PMID: 29114053 [PubMed - as supplied by publisher]

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Bitter taste responses of gustducin-positive taste cells in mouse fungiform and circumvallate papillae.

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Bitter taste responses of gustducin-positive taste cells in mouse fungiform and circumvallate papillae.

Neuroscience. 2017 Nov 04;:

Authors: Yoshida R, Takai S, Sanematsu K, Margolskee RF, Shigemura N, Ninomiya Y

Abstract
Bitter taste serves as an important signal for potentially poisonous compounds in foods to avoid their ingestion. Thousands of compounds are estimated to taste bitter and presumed to activate taste receptor cells expressing bitter taste receptors (Tas2rs) and coupled transduction components including gustducin, phospholipase Cβ2 (PLCβ2) and transient receptor potential channel M5 (TRPM5). Indeed, some gustducin-positive taste cells have been shown to respond to bitter compounds. However, there has been no systematic characterization of their response properties to multiple bitter compounds and the role of transduction molecules in these cells. In this study, we investigated bitter taste responses of gustducin-positive taste cells in situ in mouse fungiform (anterior tongue) and circumvallate (posterior tongue) papillae by using transgenic mice expressing green fluorescent protein in gustducin-positive cells. The overall response profile of gustducin-positive taste cells to multiple bitter compounds (quinine, denatonium, cyclohexamide, caffeine, sucrose octaacetate, tetraethylammonium, phenylthiourea, L-phenylalanine, MgSO4, and high concentration of saccharin) was not significantly different between fungiform and circumvallate papillae. These bitter-sensitive taste cells were classified into several groups according to their responsiveness to multiple bitter compounds. Bitter responses of gustducin-positive taste cells were significantly suppressed by inhibitors of TRPM5 or PLCβ2. In contrast, several bitter inhibitors did not show any effect on bitter responses of taste cells. These results indicate that bitter-sensitive taste cells display heterogeneous responses and that TRPM5 and PLCβ2 are indispensable for eliciting bitter taste responses of gustducin-positive taste cells.

PMID: 29113930 [PubMed - as supplied by publisher]

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Activation of the Aryl Hydrocarbon Receptor Interferes with Early Embryonic Development.

Activation of the Aryl Hydrocarbon Receptor Interferes with Early Embryonic Development.

Stem Cell Reports. 2017 Oct 24;:

Authors: Gialitakis M, Tolaini M, Li Y, Pardo M, Yu L, Toribio A, Choudhary JS, Niakan K, Papayannopoulos V, Stockinger B

Abstract
The transcriptional program of early embryonic development is tightly regulated by a set of well-defined transcription factors that suppress premature expression of differentiation genes and sustain the pluripotent identity. It is generally accepted that this program can be perturbed by environmental factors such as chemical pollutants; however, the precise molecular mechanisms remain unknown. The aryl hydrocarbon receptor (AHR) is a widely expressed nuclear receptor that senses environmental stimuli and modulates target gene expression. Here, we have investigated the AHR interactome in embryonic stem cells by mass spectrometry and show that ectopic activation of AHR during early differentiation disrupts the differentiation program via the chromatin remodeling complex NuRD (nucleosome remodeling and deacetylation). The activated AHR/NuRD complex altered the expression of differentiation-specific genes that control the first two developmental decisions without affecting the pluripotency program. These findings identify a mechanism that allows environmental stimuli to disrupt embryonic development through AHR signaling.

PMID: 29107595 [PubMed - as supplied by publisher]

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Genetic Labeling of Car4-expressing Cells Reveals Subpopulations of Type III Taste Cells.

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Genetic Labeling of Car4-expressing Cells Reveals Subpopulations of Type III Taste Cells.

Chem Senses. 2017 Oct 31;42(9):747-758

Authors: Lossow K, Hermans-Borgmeyer I, Behrens M, Meyerhof W

Abstract
Carbonic anhydrases form an enzyme family of 16 members, which reversibly catalyze the hydration of carbon dioxide to bicarbonate and protons. In lung, kidney, and brain, presence of carbonic anhydrases is associated with protons and bicarbonate transport in capillary endothelium of lung, reabsorption of bicarbonate in proximal renal tubules, and extracellular buffering. In contrast, their role in taste is less clear. Recently, carbonic anhydrase IV expression was detected in sour-sensing presynaptic taste cells and was associated with the taste of carbonation, yet the precise role and cell population remained uncertain. To examine the role of carbonic anhydrase 4-expressing cells in taste reception, we generated a mouse strain carrying a modified allele of the carbonic anhydrase 4 gene in which the coding region of the red fluorescent protein monomeric Cherry is attached to that of carbonic anhydrase 4 via an internal ribosome entry site. Monomeric Cherry fluorescence was detected in lingual papillae as well as taste buds of soft palate and naso-incisor duct. However, expression patterns on the tongue differ between posterior and fungiform papillae. Whereas monomeric Cherry auto-fluorescence was almost always co-localized with presynaptic cell markers aromatic L-amino-acid decarboxylase, synaptosomal-associated protein 25 or glutamic acid decarboxylase 67 in fungiform papillae and taste buds of palate and naso-incisor duct, monomeric Cherry-positive cells in posterior tongue papillae represent only a subpopulation of presynaptic cells. We conclude that this model is well suited for detailed investigation into the role of carbonic anhydrase in gustation and other processes.

PMID: 29099943 [PubMed - in process]

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The Role of Templating in the Emergence of RNA from the Prebiotic Chemical Mixture.

The Role of Templating in the Emergence of RNA from the Prebiotic Chemical Mixture.

Life (Basel). 2017 Oct 31;7(4):

Authors: Tupper AS, Shi K, Higgs PG

Abstract
Biological RNA is a uniform polymer in three senses: it uses nucleotides of a single chirality; it uses only ribose sugars and four nucleobases rather than a mixture of other sugars and bases; and it uses only 3'-5' bonds rather than a mixture of different bond types. We suppose that prebiotic chemistry would generate a diverse mixture of potential monomers, and that random polymerization would generate non-uniform strands of mixed chirality, monomer composition, and bond type. We ask what factors lead to the emergence of RNA from this mixture. We show that template-directed replication can lead to the emergence of all the uniform properties of RNA by the same mechanism. We study a computational model in which nucleotides react via polymerization, hydrolysis, and template-directed ligation. Uniform strands act as templates for ligation of shorter oligomers of the same type, whereas mixed strands do not act as templates. The three uniform properties emerge naturally when the ligation rate is high. If there is an exact symmetry, as with the chase of chirality, the uniform property arises via a symmetry-breaking phase transition. If there is no exact symmetry, as with monomer selection and backbone regioselectivity, the uniform property emerges gradually as the rate of template-directed ligation is increased.

PMID: 29088116 [PubMed]

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Salmonella enterica Serovar Typhimurium Strategies for Host Adaptation.

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Salmonella enterica Serovar Typhimurium Strategies for Host Adaptation.

Front Microbiol. 2017;8:1983

Authors: Anderson CJ, Kendall MM

Abstract
Bacterial pathogens must sense and respond to newly encountered host environments to regulate the expression of critical virulence factors that allow for niche adaptation and successful colonization. Among bacterial pathogens, non-typhoidal serovars of Salmonella enterica, such as serovar Typhimurium (S. Tm), are a primary cause of foodborne illnesses that lead to hospitalizations and deaths worldwide. S. Tm causes acute inflammatory diarrhea that can progress to invasive systemic disease in susceptible patients. The gastrointestinal tract and intramacrophage environments are two critically important niches during S. Tm infection, and each presents unique challenges to limit S. Tm growth. The intestinal tract is home to billions of commensal microbes, termed the microbiota, which limits the amount of available nutrients for invading pathogens such as S. Tm. Therefore, S. Tm encodes strategies to manipulate the commensal population and side-step this nutritional competition. During subsequent stages of disease, S. Tm resists host immune cell mechanisms of killing. Host cells use antimicrobial peptides, acidification of vacuoles, and nutrient limitation to kill phagocytosed microbes, and yet S. Tm is able to subvert these defense systems. In this review, we discuss recently described molecular mechanisms that S. Tm uses to outcompete the resident microbiota within the gastrointestinal tract. S. Tm directly eliminates close competitors via bacterial cell-to-cell contact as well as by stimulating a host immune response to eliminate specific members of the microbiota. Additionally, S. Tm tightly regulates the expression of key virulence factors that enable S. Tm to withstand host immune defenses within macrophages. Additionally, we highlight the chemical and physical signals that S. Tm senses as cues to adapt to each of these environments. These strategies ultimately allow S. Tm to successfully adapt to these two disparate host environments. It is critical to better understand bacterial adaptation strategies because disruption of these pathways and mechanisms, especially those shared by multiple pathogens, may provide novel therapeutic intervention strategies.

PMID: 29075247 [PubMed]

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Detection of trace concentrations of S-nitrosothiols by means of a capacitive sensor.

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Detection of trace concentrations of S-nitrosothiols by means of a capacitive sensor.

PLoS One. 2017;12(10):e0187149

Authors: Seckler JM, Meyer NM, Burton ST, Bates JN, Gaston B, Lewis SJ

Abstract
Small molecule S-nitrosothiols are a class of endogenous chemicals in the body, which have been implicated in a variety of biological functions. However, the labile nature of NO and the limits of current detection assays have made studying these molecules difficult. Here we present a method for detecting trace concentrations of S-nitrosothiols in biological fluids. Capacitive sensors when coupled to a semiconducting material represent a method for detecting trace quantities of a chemical in complex solutions. We have taken advantage of the semiconducting and chemical properties of polydopamine to construct a capacitive sensor and associated method of use, which specifically senses S-nitrosothiols in complex biological solutions.

PMID: 29073241 [PubMed - in process]

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Motor signatures in autism spectrum disorder: the importance of variability.

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Motor signatures in autism spectrum disorder: the importance of variability.

J Neurophysiol. 2016 Mar;115(3):1081-4

Authors: Parma V, de Marchena AB

Abstract
In a recent study, Wang et al. (J Neurophysiol 113: 1989-2001, 2015) used a precision grip force control task to unveil the contribution of feedforward and feedback mechanisms to sensorimotor dysfunction in autism spectrum disorder (ASD). Impairment of both motor control mechanisms was observed, along with significant variability in the motor response. In this Neuro Forum article we discuss these findings within the conceptual framework of the grasping circuit and within the broader context of clinical and research applications based on motor behavior.

PMID: 26269560 [PubMed - indexed for MEDLINE]

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Unsolved mysteries: Magnetoreception-A sense without a receptor.

Unsolved mysteries: Magnetoreception-A sense without a receptor.

PLoS Biol. 2017 Oct 23;15(10):e2003234

Authors: Nordmann GC, Hochstoeger T, Keays DA

Abstract
Evolution has equipped life on our planet with an array of extraordinary senses, but perhaps the least understood is magnetoreception. Despite compelling behavioral evidence that this sense exists, the cells, molecules, and mechanisms that mediate sensory transduction remain unknown. So how could animals detect magnetic fields? We introduce and discuss 3 concepts that attempt to address this question: (1) a mechanically sensitive magnetite-based magnetoreceptor, (2) a light-sensitive chemical-based mechanism, and (3) electromagnetic induction within accessory structures. In discussing the merits and issues with each of these ideas, we draw on existing precepts in sensory biology. We argue that solving this scientific mystery will require the development of new genetic tools in magnetosensitive species, coupled with an interdisciplinary approach that bridges physics, behavior, anatomy, physiology, molecular biology, and genetics.

PMID: 29059181 [PubMed - as supplied by publisher]

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A mammalian blood odor component serves as an approach-avoidance cue across phylum border - from flies to humans.

A mammalian blood odor component serves as an approach-avoidance cue across phylum border - from flies to humans.

Sci Rep. 2017 Oct 20;7(1):13635

Authors: Arshamian A, Laska M, Gordon AR, Norberg M, Lahger C, Porada DK, Jelvez Serra N, Johansson E, Schaefer M, Amundin M, Melin H, Olsson A, Olsson MJ, Stensmyr M, Lundström JN

Abstract
Chemosignals are used by predators to localize prey and by prey to avoid predators. These cues vary between species, but the odor of blood seems to be an exception and suggests the presence of an evolutionarily conserved chemosensory cue within the blood odor mixture. A blood odor component, E2D, has been shown to trigger approach responses identical to those triggered by the full blood odor in mammalian carnivores and as such, is a key candidate as a food/alarm cue in blood. Using a multidisciplinary approach, we demonstrate that E2D holds the dual function of affecting both approach and avoidance behavior in a predator-prey predicted manner. E2D evokes approach responses in two taxonomically distant blood-seeking predators, Stable fly and Wolf, while evoking avoidance responses in the prey species Mouse. We extend this by demonstrating that this chemical cue is preserved in humans as well; E2D induces postural avoidance, increases physiological arousal, and enhances visual perception of affective stimuli. This is the first demonstration of a single chemical cue with the dual function of guiding both approach and avoidance in a predator-prey predicted manner across taxonomically distant species, as well as the first known chemosignal that affects both human and non-human animals alike.

PMID: 29057956 [PubMed - in process]

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Bitter and sweet taste tests are reflective of disease status in chronic rhinosinusitis.

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Bitter and sweet taste tests are reflective of disease status in chronic rhinosinusitis.

J Allergy Clin Immunol Pract. 2017 Oct 17;:

Authors: Workman AD, Brooks SG, Kohanski MA, Blasetti MT, Cowart BJ, Mansfield C, Kennedy DW, Palmer JN, Adappa ND, Reed DR, Cohen NA

PMID: 29054707 [PubMed - as supplied by publisher]

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Adhesion force sensing and activation of a membrane-bound sensor to activate nisin efflux pumps in Staphylococcus aureus under mechanical and chemical stresses.

Adhesion force sensing and activation of a membrane-bound sensor to activate nisin efflux pumps in Staphylococcus aureus under mechanical and chemical stresses.

J Colloid Interface Sci. 2017 Oct 07;512:14-20

Authors: Carniello V, Harapanahalli AK, Busscher HJ, van der Mei HC

Abstract
Nisin-associated-sensitivity-response-regulator (NsaRS) in Staphylococcus aureus is important for its adhesion to surfaces and resistance against antibiotics, like nisin. NsaRS consists of an intra-membrane-located sensor NsaS and a cytoplasmatically-located response-regulator NsaR, which becomes activated upon receiving phosphate groups from the intra-membrane-located sensor.
HYPOTHESIS: The intra-membrane location of the NsaS sensor leads us to hypothesize that the two-component NsaRS system not only senses "chemical" (nisin) but also "mechanical" (adhesion) stresses to modulate efflux of antibiotics from the cytoplasm.
EXPERIMENTS: NsaS sensor and NsaAB efflux pump transcript levels in S. aureus SH1000 adhering to surfaces exerting different adhesion forces were compared, in presence and absence of nisin. Adhesion forces were measured using single-bacterial contact probe atomic force microscopy.
FINDINGS: Gene expression became largest when staphylococci experienced strong adhesion forces combined with nisin-presence and the two-component NsaRS response to antibiotics was enhanced at a stronger adhesion force. This confirms that the intra-membrane-located sensor NsaS senses both chemical and mechanical stresses to modulate antibiotic clearance through the NsaAB efflux pump. This finding creates better understanding of the antibiotic resistance of bacteria adhering to surfaces and, in the fight against antibiotic-resistant pathogens, may aid development of advanced biomaterials on which bacterial efflux pumps are not activated.

PMID: 29054003 [PubMed - as supplied by publisher]

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Effect of radiation on sucrose detection thresholds of mice.

Effect of radiation on sucrose detection thresholds of mice.

Chem Senses. 2017 Oct 19;:

Authors: Jewkes BC, Barlow LA, Delay ER

Abstract
Radiotherapy is one of the most common treatments for head and neck cancers, with an almost obligate side effect of altered taste (Conger 1973). In mice, targeted irradiation of the head and neck causes transient repression of proliferation of basal epithelial cells responsible for taste cell replacement, leading to a temporary depletion of taste sensory cells within taste buds, including Type II taste cells involved in detection of sweet stimuli (Nguyen et al. 2012). These findings suggest that irradiation may elevate sucrose detection thresholds, peaking at 7 days post-irradiation when loss of Type II cells is greatest. To test this hypothesis, sucrose detection thresholds (concentration detected in 50% of presentations) were measured in mice for 15 days after treatment of: 1) irradiation while anesthetized, 2) anesthetic alone, or 3) saline. Mice were trained to distinguish water from several concentrations of sucrose. Mice were irradiated with one 8 Gy dose (RADSOURCE-2000 X-ray Irradiator) to the nose and mouth while under 2,2,2-tribromethanol anesthesia (Avertin). Unexpectedly, mice given anesthesia showed a small elevation in sucrose thresholds compared to saline-injected mice, but irradiated mice show significantly elevated sucrose thresholds compared to either control group, an effect that peaked at 6-8 days post-irradiation. The timing of loss and recovery of sucrose sensitivity generally coincides with the reported maximal reduction and recovery of Type II taste cells (Nguyen et al. 2012). Thus, even a single dose of irradiation can significantly alter detection of carbohydrates, an important consideration for patients undergoing radiotherapy.

PMID: 29053803 [PubMed - as supplied by publisher]

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The Influence of Circadian Timing on Olfactory Sensitivity.

The Influence of Circadian Timing on Olfactory Sensitivity.

Chem Senses. 2017 Oct 17;:

Authors: Herz RS, Van Reen E, Barker D, Hilditch CJ, Bartz A, Carskadon MA

Abstract
Olfactory sensitivity has traditionally been viewed as a trait that varies according to individual differences but is not expected to change with one's momentary state. Recent research has begun to challenge this position and time of day has been shown to alter detection levels. Links between obesity and the timing of food intake further raise the issue of whether odor detection may vary as a function of circadian processes. To investigate this question, thirty-seven (21 male) adolescents (M age =13.7 years) took part in a 28-hr forced-desynchrony (FD) protocol with 17.5 hours awake and 10.5 hours of sleep, for seven FD cycles. Odor threshold was measured using Sniffin' Sticks six times for each FD cycle (total threshold tests = 42). Circadian phase was determined by intrinsic period derived from dim light melatonin onsets. Odor threshold showed a significant effect of circadian phase, with lowest threshold occurring on average slightly after the onset of melatonin production, or about 1.5 ○ (approximately 21:08 hours). Considerable individual variability was observed, however, peak olfactory acuity never occurred between 80.5 ○- 197.5 ○ (~02:22-10:10 hours). These data are the first to show that odor threshold is differentially and consistently influenced by circadian timing, and is not a stable trait. Potential biological relevance for connections between circadian phase and olfactory sensitivity are discussed.

PMID: 29045623 [PubMed - as supplied by publisher]

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Super- and subadditive neural processing of dynamic auditory-visual objects in the presence of congruent odors.

Super- and subadditive neural processing of dynamic auditory-visual objects in the presence of congruent odors.

Chem Senses. 2017 Oct 16;:

Authors: Ohla K, Höchenberger R, Freiherr J, Lundström JN

Abstract
Our sensory experiences comprise a variety of different inputs at any given time. Some of these experiences are unmistakable, others are ambiguous and profit from additional sensory information. Here, we explored whether the presence of a congruent odor influences the neural processing and sensory interaction of audio-visual objects using degraded videos (V) and sounds (A) of dynamic objects in unimodal and bimodal (AV) combinations without or with a congruent odor (VO, AO, AVO). Analyses of EEG data revealed super- and subadditive interaction effects. The topography and timing of these effects suggest evaluative rather than sensory processes as the underlying cause. Together, the results suggest that the mere presence of an odor affects the processing of A, V, and AV objects differently while multisensory interactions of AV and AVO objects have common neuronal mechanisms pointing to a robust, modality-independent network for the processing of redundant sensory information.

PMID: 29045615 [PubMed - as supplied by publisher]

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Zebrafish aversive taste co-receptor is expressed in both chemo- and mechanosensory cells and plays a role in lateral line development.

Zebrafish aversive taste co-receptor is expressed in both chemo- and mechanosensory cells and plays a role in lateral line development.

Sci Rep. 2017 Oct 18;7(1):13475

Authors: Mojib N, Xu J, Bartolek Z, Imhoff B, McCarty NA, Shin CH, Kubanek J

Abstract
Fishes rely on both chemical and tactile senses to orient themselves to avoid predators, and to detect and taste food. This is likely achieved by highly coordinated reception of signals by mechano- and chemosensory receptors in fish. A small co-receptor from zebrafish, receptor activity modifying protein (RAMP)-like triterpene glycoside receptor (RL-TGR), was previously found to be involved in recognition of triterpene glycosides, a family of naturally occurring compounds that act as chemical defenses in various prey species. However, its localization, function, and how it impacts sensory organ development in vivo is not known. Here we show that RL-TGR is expressed in zebrafish in both i) apical microvilli of the chemosensory cells of taste buds including the epithelium of lips and olfactory epithelium, and ii) mechanosensory cells of neuromasts belonging to the lateral line system. Loss-of-function analyses of RL-TGR resulted in significantly decreased number of neuromasts in the posterior lateral line system and decreased body length, suggesting that RL-TGR is involved in deposition and migration of the neuromasts. Collectively, these results provide the first in vivo genetic evidence of sensory cell-specific expression of this unusual co-receptor and reveal its additional role in the lateral line development in zebrafish.

PMID: 29044184 [PubMed - in process]

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From nose to memory: the involuntary nature of odor-evoked autobiographical memories in Alzheimer's disease.

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From nose to memory: the involuntary nature of odor-evoked autobiographical memories in Alzheimer's disease.

Chem Senses. 2017 Oct 11;:

Authors: El Haj M, Gandolphe MC, Gallouj K, Kapogiannis D, Antoine P

Abstract
Research suggests that odors may serve as a potent cue for autobiographical retrieval. We tested this hypothesis in Alzheimer's disease (AD) and investigated whether odor-evoked autobiographical memory is an involuntary process that shares similarities with music-evoked autobiographical memory. Participants with mild AD and controls were asked to retrieve two personal memories after odor exposure, after music exposure, and in an odor-and-music-free condition. AD participants showed better specificity, emotional experience, mental time travel, and retrieval time after odor and music exposure than in the control condition. Similar beneficial effects of odor and music exposure were observed for autobiographical characteristics (i.e., specificity, emotional experience, and mental time travel), except for retrieval time which was more improved after odor than after music exposure. Interestingly, regression analyses suggested executive involvement in memories evoked in the control condition but not in those evoked after music or odor exposure. These findings suggest the involuntary nature of odor-evoked autobiographical memory in AD. They also suggest that olfactory cuing could serve as a useful and ecologically valid tool to stimulate autobiographical memory, at least in the mild stage of the disease.

PMID: 29040475 [PubMed - as supplied by publisher]

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Differences in the Density of Fungiform Papillae and Composition of Saliva in Patients With Taste Disorders Compared to Healthy Controls.

Differences in the Density of Fungiform Papillae and Composition of Saliva in Patients With Taste Disorders Compared to Healthy Controls.

Chem Senses. 2017 Oct 01;42(8):699-708

Authors: Walliczek-Dworschak U, Schöps F, Feron G, Brignot H, Hähner A, Hummel T

Abstract
This study investigated the relation of the fungiform taste papillae density and saliva composition with the taste perception of patients suffering from diagnosed taste disorders. For this purpose, 81 patients and 40 healthy subjects were included. Taste was measured by means of regional and whole mouth chemosensory tests, and electrogustometry. Olfaction was assessed using the Sniffin Sticks. Fungiform papillae were quantified using the "Denver Papillae Protocol for Objective Analysis of Fungiform Papillae". In addition, salivary parameters [flow rate, total proteins, catalase, total anti-oxidative capacity (TAC), carbonic anhydrase VI (caVI), and pH] were determined and the Beck Depression Inventory was administered. Patients showed less taste papillae compared to healthy subjects. The number of papillae correlated with total taste strip score and salivary flow rate. Regarding salivary parameters, the flow rate, protein concentration, and TAC of patients were higher compared to controls. In addition, salivary flow rate, protease, caVI, and catalase values correlated with the summed taste strip score. Regarding various taste disorders, salty-dysgeusia patients showed the lowest taste test scores compared to those with bitter or metal-dysgeusia. Olfactory function of patients was significantly worse compared to healthy controls. This difference was most pronounced for ageusia patients. Compared to controls, patients also exhibited higher depressive symptoms. The density of fungiform papillae seemed to be positively associated with taste perception. Furthermore, patients exhibited changes in saliva composition (higher salivary flow rate, increased protein concentration, proteolysis, and TAC) compared to controls indicating that assessment of saliva may be critical for the diagnostic procedure in taste disorders.

PMID: 28981826 [PubMed - in process]

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The Influence of Sniffing on Airflow and Odorant Deposition in the Canine Nasal Cavity.

The Influence of Sniffing on Airflow and Odorant Deposition in the Canine Nasal Cavity.

Chem Senses. 2017 Oct 01;42(8):683-698

Authors: Rygg AD, Van Valkenburgh B, Craven BA

Abstract
Nasal airflow plays a critical role in olfaction by transporting odorant from the environment to the olfactory epithelium, where chemical detection occurs. Most studies of olfaction neglect the unsteadiness of sniffing and assume that nasal airflow and odorant transport are "quasi-steady," wherein reality most mammals "sniff." Here, we perform computational fluid dynamics simulations of airflow and odorant deposition in an anatomically accurate model of the coyote (Canis latrans) nasal cavity during quiet breathing, a notional quasi-steady sniff, and unsteady sniffing to: quantify the influence of unsteady sniffing, assess the validity of the quasi-steady assumption, and investigate the functional advantages of sniffing compared to breathing. Our results reveal that flow unsteadiness during sniffing does not appreciably influence qualitative (gross airflow and odorant deposition patterns) or quantitative (time-averaged olfactory flow rate and odorant uptake) measures of olfactory function. A quasi-steady approximation is, therefore, justified for simulating time-averaged olfactory function in the canine nose. Simulations of sniffing versus quiet breathing demonstrate that sniffing delivers about 2.5 times more air to the olfactory recess and results in 2.5-3 times more uptake of highly- and moderately-soluble odorants in the sensory region per unit time, suggesting one reason why dogs actively sniff. Simulations also reveal significantly different deposition patterns in the olfactory region during inspiration for different odorants, and that during expiration there is little retronasal odorant deposition in the sensory region. These results significantly improve our understanding of canine olfaction, and have several practical implications regarding computer simulation of olfactory function.

PMID: 28981825 [PubMed - in process]

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Thirst Increases Chorda Tympani Responses to Sodium Chloride.

Thirst Increases Chorda Tympani Responses to Sodium Chloride.

Chem Senses. 2017 Oct 01;42(8):675-681

Authors: Mast TG, Breza JM, Contreras RJ

Abstract
In nature, water is present as a low-salt solution, thus we hypothesized that thirst would increase taste responses to low-salt solutions. We investigated the effect of thirst on the 2 different salt detection mechanisms present in the rat chorda tympani (CT) nerve. The first mechanism is dependent upon the epithelial sodium channel (ENaC), is blocked by benzamil, and is specific to the cation sodium. The second mechanism, while undefined, is independent of ENaC, and detects multiple cations. We expected thirst to increase benzamil-sensitive sodium responses due to mechanistically increasing the benzamil-sensitive ENaC. We recorded CT whole-nerve electrophysiological responses to lingual application of NaCl, KCl (30, 75, 150, 300, 500, and 600 mM), and imitation rainwater in both control and 24-h water-restricted male rats. NaCl solutions were presented in artificial saliva before and after lingual application of 5µM benzamil. Water restriction significantly increased the integrated CT responses to NaCl but not to KCl or imitation rainwater. Consistent with our hypothesis, only the benzamil-sensitive, and not the benzamil-insensitive, CT sodium response significantly increased. Additionally, CT responses to salt were recorded following induction of either osmotic or volemic thirst. Both thirsts significantly enhanced the integrated CT responses to NaCl and KCl, but not imitation rainwater. Interestingly, osmotic and volemic thirsts increased CT responses by increasing both the benzamil-sensitive and benzamil-insensitive CT sodium responses. We propose that thirst increases the sensitivity of the CT nerve to sodium.

PMID: 28981824 [PubMed - in process]

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Developmental Fine-tuning of Human Olfactory Discriminability.

Developmental Fine-tuning of Human Olfactory Discriminability.

Chem Senses. 2017 Oct 01;42(8):655-662

Authors: Zhang X, Chen W, Li S, Zhou W

Abstract
Unlike vision or audition, human olfaction is generally considered evolutionarily ancient and well-functioning at birth, yet there have been few empirical data on the development of olfactory acuity. The current study has assessed olfactory discriminability in children aged 3 to 6 years with 16 pairs of single-compound odorants that differ in various degrees in structure and smell. We report a significant improvement over age in young children's overall olfactory discriminability. Critically, such improvement is modulated by the degree of structural similarity between odorants independent of odor familiarity. Our findings indicate that odor representations in the olfactory system are fine-tuned during early childhood (3-6 years of age) to allow refined discrimination. Moreover, they suggest the need to take molecular similarity into consideration in the evaluation of olfactory discrimination in pediatric populations.

PMID: 28981823 [PubMed - in process]

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Human Fear Chemosignaling: Evidence from a Meta-Analysis.

Human Fear Chemosignaling: Evidence from a Meta-Analysis.

Chem Senses. 2017 Oct 01;42(8):663-673

Authors: de Groot JHB, Smeets MAM

Abstract
Alarm pheromones are widely used in the animal kingdom. Notably, there are 26 published studies (N = 1652) highlighting a human capacity to communicate fear, stress, and anxiety via body odor from one person (66% males) to another (69% females). The question is whether the findings of this literature reflect a true effect, and what the average effect size is. These questions were answered by combining traditional meta-analysis with novel meta-analytical tools, p-curve analysis and p-uniform-techniques that could indicate whether findings are likely to reflect a true effect based on the distribution of P-values. A traditional random-effects meta-analysis yielded a small-to-moderate effect size (Hedges' g: 0.36, 95% CI: 0.31-0.41), p-curve analysis showed evidence diagnostic of a true effect (ps < 0.0001), and there was no evidence for publication bias. This meta-analysis did not assess the internal validity of the current studies; yet, the combined results illustrate the statistical robustness of a field in human olfaction dealing with the human capacity to communicate certain emotions (fear, stress, anxiety) via body odor.

PMID: 28981822 [PubMed - in process]

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Sodium Carbonate is Saltier Than Sodium Chloride to Sodium-Depleted Rats.

Sodium Carbonate is Saltier Than Sodium Chloride to Sodium-Depleted Rats.

Chem Senses. 2017 Oct 01;42(8):647-653

Authors: St John SJ, McBrayer AM, Krauskopf EE

Abstract
In a series of behavioral experiments in the 1960s, G.R. Morrison identified several unique features of the taste of Na2CO3 to rats; namely, it is 1) considerably more intense than NaCl at isomolar concentrations, 2) avoided at 10 times lower concentrations than NaCl to thirsty rats, 3) preferred at 10 times lower concentrations than NaCl in sodium-depleted rats. He also demonstrated its qualitatively similarity to NaCl. In Experiment 1, we confirmed and extended many of Morrison's observations. Rats were injected with furosemide on 3 occasions to stimulate a sodium appetite. After each depletion, rats were given a brief-access taste test in a lickometer presenting, in random order, water and 7 concentrations of salt. One test used NaCl (0.028-0.89 M, quarter log steps), another used Na2CO3, and the third used Na2CO3, but at a tenfold lower concentration range (0.0028-0.089 M). Rats licked NaCl in an inverted-U shaped concentration-response function peaking at 0.158-0.281 M. As Morrison's results predicted, rats licked Na2CO3 in nearly identical fashion, but at a tenfold lower concentration range (peak at 0.0158-0.028 M). In a second experiment, furosemide-treated rats were repeatedly tested with the lower Na2CO3 range but mixed in the epithelial sodium channel blocker amiloride at various concentrations (3-300 μM, half log steps). Amiloride reduced licking for Na2CO3 and shifted the peak response rightward up to about half a log unit. Thus, this "super-saltiness" of Na2CO3 to rats is at least partly amiloride-dependent.

PMID: 28981821 [PubMed - in process]

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Oral Digestion and Perception of Starch: Effects of Cooking, Tasting Time, and Salivary α-Amylase Activity.

Oral Digestion and Perception of Starch: Effects of Cooking, Tasting Time, and Salivary α-Amylase Activity.

Chem Senses. 2017 Oct 01;42(8):635-645

Authors: Lapis TJ, Penner MH, Balto AS, Lim J

Abstract
Since starch is a significant part of human diet, its oral detection would be highly beneficial. This study was designed to determine whether starch or its degradation products can be tasted and what factors influence its perception. Subjects were asked 1) to taste 8% raw and cooked starch samples for 5, 15, and 35 s and rate perceived intensities of sweetness and "other" taste (i.e., other than sweet), 2) to donate saliva to obtain salivary flow rate (mg/s) and salivary α-amylase activity (per mg saliva), and 3) to fill out a carbohydrate consumption survey. Subsequently, in vitro hydrolysis of starch was performed; saliva was collected from 5 subjects with low and high amylase activities and reacted with 8% raw and cooked starch at 2, 15, and 30 s. Hydrolysis products were then quantified using a High performance liquid chromatography. The results showed cooking increased the digestibility of starch such that the amount of hydrolysis products increased with reaction time. However, cooking did not influence taste ratings, nor were they influenced by tasting time. Subjects' salivary amylase activities were associated with the efficacy of their saliva to degrade starch, in particular cooked starch, and thus the amount of maltooligosaccharide products generated. Effective α-amylase activity [i.e. α-amylase activity (per mg saliva) × salivary flow rate (mg/s)] and carbohydrate consumption score (i.e. consumption frequency × number of servings) were also independently associated with sensory taste ratings. Human perception of starch is undoubtedly complex as shown in this study; the data herein point to the potential roles of salivary α-amylase activity and carbohydrate consumption in the perception of cooked starch.

PMID: 28981820 [PubMed - in process]

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Nostril Differences in the Olfactory Performance in Health and Disease.

Nostril Differences in the Olfactory Performance in Health and Disease.

Chem Senses. 2017 Oct 01;42(8):625-634

Authors: Poupon D, Hummel T, Haehner A, Welge-Luessen A, Frasnelli J

Abstract
In the past few decades, several olfactory tests have been developed to assess olfactory performance and detect disorders. Contrary to other sensory systems, both nostrils are usually tested together; we hypothesized that monorhinal testing may reveal side differences in sensitivity which may be useful for the diagnosis of olfactory dysfunction. Using the "Sniffin' Sticks" test, we assessed olfactory function of 458 participants (278 healthy controls, 180 hyposmic patients), one nostril after the other, with 3 different tasks. For each participant and each task, we compared the scores obtained with both nostrils, and defined the best and worst nostrils. Thus we were able to establish normative data and to define cut-off values. Our results suggest that scores obtained with the worst nostril are the most efficient in detecting an olfactory disorder. This supports the importance of monorhinal testing, as it can allow an earlier and more accurate diagnosis than birhinal testing. This may be especially useful in the context of early detection of neurodegenerative diseases.

PMID: 28981819 [PubMed - in process]

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Bacterial d-amino acids suppress sinonasal innate immunity through sweet taste receptors in solitary chemosensory cells.

Related Articles

Bacterial d-amino acids suppress sinonasal innate immunity through sweet taste receptors in solitary chemosensory cells.

Sci Signal. 2017 Sep 05;10(495):

Authors: Lee RJ, Hariri BM, McMahon DB, Chen B, Doghramji L, Adappa ND, Palmer JN, Kennedy DW, Jiang P, Margolskee RF, Cohen NA

Abstract
In the upper respiratory epithelium, bitter and sweet taste receptors present in solitary chemosensory cells influence antimicrobial innate immune defense responses. Whereas activation of bitter taste receptors (T2Rs) stimulates surrounding epithelial cells to release antimicrobial peptides, activation of the sweet taste receptor (T1R) in the same cells inhibits this response. This mechanism is thought to control the magnitude of antimicrobial peptide release based on the sugar content of airway surface liquid. We hypothesized that d-amino acids, which are produced by various bacteria and activate T1R in taste receptor cells in the mouth, may also activate T1R in the airway. We showed that both the T1R2 and T1R3 subunits of the sweet taste receptor (T1R2/3) were present in the same chemosensory cells of primary human sinonasal epithelial cultures. Respiratory isolates of Staphylococcus species, but not Pseudomonas aeruginosa, produced at least two d-amino acids that activate the sweet taste receptor. In addition to inhibiting P. aeruginosa biofilm formation, d-amino acids derived from Staphylococcus inhibited T2R-mediated signaling and defensin secretion in sinonasal cells by activating T1R2/3. d-Amino acid-mediated activation of T1R2/3 also enhanced epithelial cell death during challenge with Staphylococcus aureus in the presence of the bitter receptor-activating compound denatonium benzoate. These data establish a potential mechanism for interkingdom signaling in the airway mediated by bacterial d-amino acids and the mammalian sweet taste receptor in airway chemosensory cells.

PMID: 28874606 [PubMed - in process]

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Development of a Nonionic Azobenzene Amphiphile for Remote Photocontrol of a Model Biomembrane.

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Development of a Nonionic Azobenzene Amphiphile for Remote Photocontrol of a Model Biomembrane.

J Phys Chem B. 2016 05 05;120(17):4053-63

Authors: Benedini LA, Sequeira MA, Fanani ML, Maggio B, Dodero VI

Abstract
We report the synthesis and characterization of a simple nonionic azoamphiphile, C12OazoE3OH, which behaves as an optically controlled molecule alone and in a biomembrane environment. First, Langmuir monolayer and Brewster angle microscopy (BAM) experiments showed that pure C12OazoE3OH enriched in the (E) isomer was able to form solidlike mesophase even at low surface pressure associated with supramolecular organization of the azobenzene derivative at the interface. On the other hand, pure C12OazoE3OH enriched in the (Z) isomer formed a less solidlike monolayer due to the bent geometry around the azobenzene moiety. Second, C12OazoE3OH is well-mixed in a biological membrane model, Lipoid s75 (up to 20%mol), and photoisomerization among the lipids proceeded smoothly depending on light conditions. It is proposed that the cross-sectional area of the hydroxyl triethylenglycol head of C12OazoE3OH inhibits azobenzenes H-aggregation in the model membrane; thus, the tails conformation change due to photoisomerization is transferred efficiently to the lipid membrane. We showed that the lipid membrane effectively senses the azobenzene geometrical change photomodulating some properties, like compressibility modulus, transition temperature, and morphology. In addition, photomodulation proceeds with a color change from yellow to orange, providing the possibility to externally monitor the system. Finally, Gibbs monolayers showed that C12OazoE3OH is able to penetrate the highly packing biomembrane model; thus, C12OazoE3OH might be used as photoswitchable molecular probe in real systems.

PMID: 27070294 [PubMed - indexed for MEDLINE]

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Total synthesis of architecturally complex indole terpenoids: strategic and tactical evolution.

Related Articles

Total synthesis of architecturally complex indole terpenoids: strategic and tactical evolution.

J Antibiot (Tokyo). 2017 Aug 30;:

Authors: Zou Y, Smith Iii AB

Abstract
Indole terpenes have attracted the interests of synthetic chemists due to their complex architectures and potent biological activities. Examples of total syntheses of several indole terpenes were reviewed in this article to honor Professor KC Nicolaou.The Journal of Antibiotics advance online publication, 30 August 2017; doi:10.1038/ja.2017.94.

PMID: 28852179 [PubMed - as supplied by publisher]

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Medical Management of Chronic Rhinosinusitis - A review of traditional and novel medical therapies.

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Medical Management of Chronic Rhinosinusitis - A review of traditional and novel medical therapies.

Expert Opin Investig Drugs. 2017 Aug 29;:

Authors: Schwartz JS, Tajudeen BA, Cohen NA

Abstract
INTRODUCTION: Chronic rhinosinusitis (CRS) is a commonly seen persistent inflammatory disease process affecting the paranasal sinuses with extensively reported economic implications. Despite an elusive pathophysiologic mechanism underlying this disease process, treatment outcomes are encouraging with the employment of an array of medical and surgical therapies. Areas covered: The goal of this paper is to provide a comprehensive, up to date analysis of the literature concerning the medical management of CRS by summarizing the evidence in support of traditional medical therapies for the management of CRS in addition to highlighting novel medical therapies currently under investigation. Expert opinion: The current staples of medical therapy for CRS based on the strength of available evidence include topical and oral corticosteroids, oral antibiotics and topical saline. The introduction of immunomodulatory therapies ("Biologics") for the treatment of CRS shows promise but have yet to be employed in a widespread fashion due to the need for additional research to better elucidate their role.

PMID: 28847168 [PubMed - as supplied by publisher]

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