Transient receptor potential vanilloid 4 gene-deficiency attenuates the inhibitory effect of 5,6-dihydroxy-8Z,11Z,14Z,17Z-eicosatetraenoic acid on vascular permeability in mice.

We investigated whether an anti-inflammatory lipid metabolite named 5,6-DiHETE reduces vascular permeability by inhibiting TRPV4 channels in vivo. In wild-type (WT) mice, histamine-induced dye extravasation was reduced by pre-administration of 5,6-DiHETE. In TRPV4-deficient mice, extravasation and histamine-induced edema were already reduced, and 5,6-DiHETE had no additional effect.

Thermosensation and TRP Channels.

Somatosensory neurons can sense external temperature by converting sensation of temperature information to neural activity via afferent input to the central nervous system. Various populations of somatosensory neurons have specialized gene expression, including expression of thermosensitive transient receptor potential (TRP) ion channels. Thermosensitive TRP channels are responsible for thermal transduction at the peripheral ends of somatosensory neurons and can sense a wide range of temperatures.

Involvement of TRPV4 in temperature-dependent perspiration in mice.

Reports indicate that an interaction between TRPV4 and anoctamin 1 (ANO1) could be widely involved in water efflux of exocrine glands, suggesting that the interaction could play a role in perspiration. In secretory cells of sweat glands present in mouse foot pads, TRPV4 clearly colocalized with cytokeratin 8, ANO1, and aquaporin-5 (AQP5). Mouse sweat glands showed TRPV4-dependent cytosolic Ca increases that were inhibited by menthol.

Thermal gradient ring for analysis of temperature-dependent behaviors involving TRP channels in mice.

There are a lot of temperature-sensitive proteins including transient receptor potential (TRP) channels. Some TRP channels are temperature receptors having specific activation temperatures in vitro that are within the physiological temperature range. Mice deficient in specific TRP channels show abnormal thermal behaviors, but the role of TRP channels in these behaviors is not fully understood.

Cell death induction and protection by activation of ubiquitously expressed anion/cation channels. Part 3: the roles and properties of TRPM2 and TRPM7.

Cell volume regulation (CVR) is a prerequisite for animal cells to survive and fulfill their functions. CVR dysfunction is essentially involved in the induction of cell death. In fact, sustained normotonic cell swelling and shrinkage are associated with necrosis and apoptosis, and thus called the necrotic volume increase (NVI) and the apoptotic volume decrease (AVD), respectively.

Protein kinase C-mediated phosphorylation of transient receptor potential melastatin type 2 Thr738 counteracts the effect of cytosolic Ca and elevates the temperature threshold.

The transient receptor potential melastatin type 2 (TRPM2) channel is a non-selective cation channel that has high Ca permeability. TRPM2 is sensitive to warm temperatures and is expressed in cells and tissues that are maintained at core body temperature. TRPM2 activity is also regulated by endogenous factors including redox signalling, cytosolic Ca and adenosine diphosphate ribose.

Single amino acids set apparent temperature thresholds for heat-evoked activation of mosquito transient receptor potential channel TRPA1.

Animals detect heat using thermosensitive transient receptor potential (TRP) channels. In insects, these include TRP ankyrin 1 (TRPA1), which in mosquitoes is crucial for noxious heat avoidance and thus is an appealing pest control target. However, the molecular basis for heat-evoked activation has not been fully elucidated, impeding both studies of the molecular evolution of temperature sensitivity and rational design of inhibitors.

TRP channels in thermosensation.

The ability to sense external temperature is assumed by somatosensory neurons, in which temperature information is converted to neural activity by afferent input to the central nervous system. Somatosensory neurons consist of various populations with specialized gene expression, including thermosensitive transient receptor potential ion channels (thermo-TRPs). Thermo-TRPs are responsible for thermal transduction at the peripheral ends of somatosensory neurons and over a wide range of temperatures.

Thermal gradient ring reveals different temperature-dependent behaviors in mice lacking thermosensitive TRP channels.

Transient receptor potential (TRP) channels are known as temperature receptors. Each channel has an activation temperature in vitro within the physiological temperature range. Mice deficient in specific TRP channels show abnormal thermal behaviors.

[Mechanisms Underlying Thermosensation].

The ability to sense ambient temperatures is essential for human survival. Sensory nerve endings contain ion channels that are activated by temperature stimuli, which lead to cation influx and depolarization with consequent action potential generation via activation of voltage-gated Na channels. Thermosensitive transient receptor potential channels play a key role in cation channels.

Thermosensitive TRPV4 channels mediate temperature-dependent microglia movement.

Microglia maintain central nervous system homeostasis by monitoring changes in their environment (resting state) and by taking protective actions to equilibrate such changes (activated state). These surveillance and protective roles both require constant movement of microglia. Interestingly, induced hypothermia can reduce microglia migration caused by ischemia, suggesting that microglia movement can be modulated by temperature.

Thermosensation involving thermo-TRPs.

The transient receptor potential (TRP) channels constitute a superfamily of large ion channels that are activated by a wide range of chemical, mechanical and thermal stimuli. TRP channels with temperature sensitivity are called thermo-TRPs. They are involved in diverse physiological functions through their detection of external environmental temperature and internal body temperature.

Involvement of TRPM2 and TRPM8 in temperature-dependent masking behavior.

Masking is a direct behavioral response to environmental changes and plays an important role in the temporal distribution of activity. However, the mechanisms responsible for masking remain unclear. Here we identify thermosensors and a possible neural circuit regulating temperature-dependent masking behavior in mice.

CALHM1/CALHM3 channel is intrinsically sorted to the basolateral membrane of epithelial cells including taste cells.

The CALHM1/CALHM3 channel in the basolateral membrane of polarized taste cells mediates neurotransmitter release. However, mechanisms regulating its localization remain unexplored. Here, we identified CALHM1/CALHM3 in the basolateral membrane of type II taste cells in discrete puncta localized close to afferent nerve fibers.

AAV-Mediated Gene Delivery to Taste Cells of the Tongue.

Taste sensation is initiated in sensory cells within the taste buds (taste cells), in which the cooperation of many signaling molecules leads to the coding and transmission of information on the quality and intensity of taste to the afferent gustatory nerves. Here, we describe our method for inducing foreign gene expression in taste cells of fungiform papillae in a living mouse using a recombinant adeno-associated virus (AAV) vector, enabling us to study and control the function of a gene product in vivo. Among the serotypes tested to date, only AAV-DJ, a synthetic serotype, can transduce taste cells in vivo.

HsTRPA of the Red Imported Fire Ant, , Functions as a Nocisensor and Uncovers the Evolutionary Plasticity of HsTRPA Channels.

, the red imported fire ant, represents one of the most devastating invasive species. To understand their sensory physiology, we identified and characterized their Hymenoptera-specific (Hs) TRPA channel, SiHsTRPA. Consistent with the sensory functions of SiHsTRPA, it is activated by heat, an electrophile, and an insect repellent.

The TRPM2 channel: A thermo-sensitive metabolic sensor.

Living organisms continually experience changes in ambient temperature. To detect such temperature changes for adaptive behavioral responses, we evolved the ability to sense temperature. Thermosensitive transient receptor potential (TRP) channels, so-called thermo-TRPs, are involved in many physiologic functions in diverse organisms and constitute important temperature sensors.

Adeno-Associated Virus-Mediated Gene Transfer into Taste Cells In Vivo.

The sense of taste is achieved by cooperation of many signaling molecules expressed in taste cells, which code and transmit information on quality and intensity of taste to the nervous system. Viral vector-mediated gene transfer techniques have been proven to be useful to study and control function of a gene product in vivo However, there is no transduction method for taste cells in live animals. Here, we have established a method for inducing foreign gene expression in mouse taste cells in vivo by recombinant adeno-associated virus (AAV) vector.

TRPA1 Channels in and Honey Bee Ectoparasitic Mites Share Heat Sensitivity and Temperature-Related Physiological Functions.

The transient receptor potential cation channel, subfamily A, member 1 (TRPA1) is conserved between many arthropods, and in some has been shown to function as a chemosensor for noxious compounds. Activation of arthropod TRPA1 channels by temperature fluctuations has been tested in only a few insect species, and all of them were shown to be activated by heat. The recent identification of chemosensitive TRPA1 channels from two honey bee ectoparasitic mite species (VdTRPA1 and TmTRPA1) have provided an opportunity to study the temperature-dependent activation and the temperature-associated physiological functions of TRPA1 channels in non-insect arthropods.

Quercetin is a Useful Medicinal Compound Showing Various Actions Including Control of Blood Pressure, Neurite Elongation and Epithelial Ion Transport.

Quercetin has multiple potential to control various cell function keeping our body condition healthy. In this review article, we describe the molecular mechanism on how quercetin exerts its action on blood pressure, neurite elongation and epithelial ion transport based from a viewpoint of cytosolic Cl- environments, which is recently recognized as an important signaling factor in various types of cells. Recent studies show various roles of cytosolic Cl- in regulation of blood pressure and neurite elongation, and prevention from bacterial and viral infection.

Isoform-specific modulation of the chemical sensitivity of conserved TRPA1 channel in the major honeybee ectoparasitic mite, Tropilaelaps mercedesae.

We identified and characterized the TRPA1 channel of Tropilaelaps mercedesae (TmTRPA1), one of two major species of honeybee ectoparasitic mite. Three TmTRPA1 isoforms with unique N-terminal sequences were activated by heat, and the isoform highly expressed in the mite's front legs, TmTRPA1b, was also activated by 27 plant-derived compounds including electrophiles. This suggests that the heat- and electrophile-dependent gating mechanisms as nocisensitive TRPA1 channel are well conserved between arthropod species.

Plant-Derived Tick Repellents Activate the Honey Bee Ectoparasitic Mite TRPA1.

We have identified and characterized the TRPA1 channel of Varroa destructor (VdTRPA1), a major ectoparasitic mite of honey bee. One of the two VdTRPA1 isoforms, VdTRPA1L, was activated by a variety of plant-derived compounds, including electrophilic compounds, suggesting that chemical activation profiles are mostly shared between arthropod TRPA1 channels. Nevertheless, carvacrol and α-terpineol activated VdTRPA1L but not a honey bee noxious-stimuli-sensitive TRPA, AmHsTRPA, and Drosophila melanogaster TRPA1.

Redox Signal-mediated Enhancement of the Temperature Sensitivity of Transient Receptor Potential Melastatin 2 (TRPM2) Elevates Glucose-induced Insulin Secretion from Pancreatic Islets.

Transient receptor potential melastatin 2 (TRPM2) is a thermosensitive Ca(2+)-permeable cation channel expressed by pancreatic β cells where channel function is constantly affected by body temperature. We focused on the physiological functions of redox signal-mediated TRPM2 activity at body temperature. H2O2, an important molecule in redox signaling, reduced the temperature threshold for TRPM2 activation in pancreatic β cells of WT mice but not in TRPM2KO cells.

Late-onset of spinal neurodegeneration in knock-in mice expressing a mutant BiP.

Most human neurodegenerative diseases are sporadic, and appear later in life. While the underlying mechanisms of the progression of those diseases are still unclear, investigations into the familial forms of comparable diseases suggest that endoplasmic reticulum (ER) stress is involved in the pathogenesis. Binding immunoglobulin protein (BiP) is an ER chaperone that is central to ER function.