title: The role of thermosensitive TRP (transient receptor potential) channels in insulin secretion.
abstract: Insulin secretion from pancreatic β-cells is the only efficient means to decrease blood glucose concentrations. Glucose is the principal stimulator of insulin secretion with the ATP-sensitive K+ channel-voltage-gated Ca2+ channel-mediated pathway being the primary one involved in glucose-stimulated insulin secretion. Recently, several reports demonstrated that some transient receptor potential (TRP) channels are expressed in pancreatic β-cells and contribute to pancreatic β-cell functions. Interestingly, six of them (TRPM2, TRPM4, TRPM5, TRPV1, TRPV2 and TRPV4) are thermosensitive TRP channels. Thermosensitive TRP channels in pancreatic β-cells can function as multimodal receptors and cause Ca2+ influx and membrane depolarization at physiological body temperature. TRPM channels (TRPM2, TRPM4 and TRPM5) control insulin secretion levels by sensing intracellular Ca2+ increase, NAD metabolites, or hormone receptor activation. TRPV2 is involved not only in insulin secretion but also cell proliferation, and is regulated by the autocrine effects of insulin. TRPV1 expressed in sensory neurons is involved in β-cell stress and islet inflammation by controlling neuropeptide release levels. It is thus clear that thermosensitive TRP channels play important roles in pancreatic β-cell functions, and future analyses of TRP channel function will lead to better understanding of the complicated mechanisms involved in insulin secretion and diabetes pathogenesis.
authors.affiliation: Division of Cell Signaling, Okazaki Institute for Integrative Bioscience (National Institute for Physiological Sciences), National Institutes of Natural Sciences, Aichi 444-8787 Japan. kuchida@nips.ac.jp
authors.forename: Kunitoshi
authors.initials: K
authors.lastname: Uchida
authors.forename: Makoto
authors.initials: M
authors.lastname: Tominaga
mesh_terms: D000818:Animals; D001831:Body Temperature; D002118:Calcium / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000378:metabolism*; D011984:Sensory Receptor Cells / Q000502:physiology; D050053:TRPM Cation Channels / Q000502:physiology; D050916:TRPV Cation Channels / Q000502:physiology; D050051:Transient Receptor Potential Channels / Q000502:physiology*
chemical_list: D007328:Insulin; D050053:TRPM Cation Channels; C121934:TRPM2 protein, human; C437888:TRPM4 protein, human; C404409:TRPM5 protein, human; D050916:TRPV Cation Channels; D050051:Transient Receptor Potential Channels; D002118:Calcium