TRPM8, a Sensor for Mild Cooling in Mammalian Sensory Nerve Endings
Abstract:Temperature sensing is a crucial feature of the nervous system, enabling organisms to avoid physical danger and choose optimal environments for survival. TRPM8 (Transient Receptor Potential Melastatin type 8) belongs to a select group of ion channels which are gated by changes in temperature, are expressed in sensory nerves and/or skin cells and may be involved in temperature sensing. This channel is activated by a moderate decrease in temperature, with a threshold of ∼25 °C in heterologous expression systems, and by a variety of natural and synthetic compounds, including menthol. While the physiological role of TRPM8 as a transducer of gentle cooling is widely accepted, its involvement in acute noxious cold sensing in healthy tissues is still under debate. Although accumulating evidence indicates that TRPM8 is involved in neuropathic cold allodynia, in some animal models of nerve injury peripheral and central activation of TRPM8 is followed by analgesia. A variety of inflammatory mediators, including bradykinin and prostaglandin E2, modulate TRPM8 by inhibiting the channel and shifting its activation threshold to colder temperatures, most likely counteracting the analgesic action of TRPM8. While important progress has been made in unraveling the biophysical features of TRPM8, including the revelation of its voltage dependence, the precise mechanism involved in temperature sensing by this channel is still not completely understood. This article will review the current status of knowledge regarding the (patho)physiological role(s) of TRPM8, its modulation by inflammatory mediators, the signaling pathways involved in this regulation, and the biophysical properties of the channel.
Keywords: Brain-Derived Neurotrophic Factor; C-fibres; CCI model; CMR1; CPS-369; Cold; Coolact P; DRG neurons; GPCRs; HEK293 cells; PKC phosphorylation; PMD-38; S4-S5 linker; TRP channels; TRPM8; TRPM8 mRNA; TRPV1; bradykinin; cDNA; cancer; cold allodynia; cysteines C929; geniculate ganglia; inflammation; innocuous cold nociception; lung epithelia; micturition reflex; mutagenesis; neuropathy; orthologue; pain; prostaglandin; prostaglandin E2; thermal grill illusion; trigeminal ganglion
Document Type: Research Article
Publication date: 2011-01-01
- Current Pharmaceutical Biotechnology aims to cover all the latest and outstanding developments in Pharmaceutical Biotechnology. Each issue of the journal contains a series of timely in-depth reviews written by leaders in the field covering a range of current topics in both pre-clinical and clinical areas of Pharmaceutical Biotechnology. Current Pharmaceutical Biotechnology is an essential journal for academic, clinical, government and pharmaceutical scientists who wish to be kept informed and up-to-date with the latest and most important developments.