Transient receptor potential cation channel subfamily V member 4 is an ion channel protein that in humans is encoded by the TRPV4 gene.
The TRPV4 gene encodes TRPV4, initially named "vanilloid-receptor related osmotically activated channel" (VR-OAC) and "OSM9-like transient receptor potential channel, member 4 (OTRPC4)", [5] [6] a member of the vanilloid subfamily in the transient receptor potential (TRP) superfamily of ion channels. [7] [8] [9] The encoded protein is a Ca2+-permeable, nonselective cation channel that has been found involved in multiple physiologic functions, dysfunctions and also disease. It functions in the regulation of systemic osmotic pressure by the brain, in vascular function, in liver, intestinal, renal and bladder function, in skin barrier function and response of the skin to ultraviolet-B radiation, in growth and structural integrity of the skeleton, in function of joints, in airway- and lung function, in retinal and inner ear function, and in pain. The channel is activated by osmotic, mechanical and chemical cues. It also responds to thermal changes (warmth). Channel activation can be sensitized by inflammation and injury.
The TRPV4 gene has been co-discovered by W. Liedtke et al. [5] and R. Strotmann et al. [6]
Channelopathy mutations in the TRPV4 gene lead to skeletal dysplasias, premature osteoarthritis, and neurological motor function disorders and are associated with a range of disorders, including brachyolmia type 3, congenital distal spinal muscular atrophy, Familial digital arthropathy-brachydactyly (FDAB), [10] scapuloperoneal spinal muscular atrophy, and subtype 2C of Charcot–Marie–Tooth disease. [11]
A number of TRPV4 agonists and antagonists have been identified since its discovery. [12] The discovery of unselective modulators (e.g. antagonist ruthenium red) was followed by the apparition of more potent (agonist 4aPDD) [13] or selective (antagonist RN-1734) [14] compounds, including some with bioavailability suitable for in vivo pharmacology studies such as agonist GSK1016790A [15] (with ~10 fold selectivity vs TRPV1), and antagonists HC-067047 [16] (with ~5 fold selectivity vs hERG and ~10 fold selectivity vs TRPM8) and RN-9893 [17] (with ~50 fold selectivity vs TRPM8 and ~10 fold selectivity vs M1).
Resolvin D1 (RvD1), a metabolite of the omega 3 fatty acid, docosahexaenoic acid, is a member of the specialized proresolving mediators (SPMs) class of metabolites that function to resolve diverse inflammatory reactions and diseases in animal models and, it is proposed, humans. This SPM also dampens pain perception arising from various inflammation-based causes in animal models. The mechanism behind this pain-dampening effect involves the inhibition of TRPV4, probably (in at least certain cases) by an indirect effect wherein it activates another receptor located on neurons or nearby microglia or astrocytes. CMKLR1, GPR32, FPR2, and NMDA receptors have been proposed to be the receptors through which a SPM may operate to down-regulate TRPs and thereby pain perception. [18] [19] [20] [21] [22]
TRPV4 has been shown to interact with MAP7 [23] and LYN. [24]
TRPV4 has been proposed to be the thermal sensor in gonads of Alligator mississipiensis , a species with temperature-dependent sex determination. [25] However the data were over interpreted and TRPV4 is probably not involved in temperature-dependent sex determination due to large overlap of expression at male producing temperature and female producing temperature for example.
Transient receptor potential channels are a group of ion channels located mostly on the plasma membrane of numerous animal cell types. Most of these are grouped into two broad groups: Group 1 includes TRPC, TRPV, TRPVL, TRPM, TRPS, TRPN, and TRPA. Group 2 consists of TRPP and TRPML. Other less-well categorized TRP channels exist, including yeast channels and a number of Group 1 and Group 2 channels present in non-animals. Many of these channels mediate a variety of sensations such as pain, temperature, different kinds of taste, pressure, and vision. In the body, some TRP channels are thought to behave like microscopic thermometers and used in animals to sense hot or cold. Some TRP channels are activated by molecules found in spices like garlic (allicin), chili pepper (capsaicin), wasabi ; others are activated by menthol, camphor, peppermint, and cooling agents; yet others are activated by molecules found in cannabis or stevia. Some act as sensors of osmotic pressure, volume, stretch, and vibration. Most of the channels are activated or inhibited by signaling lipids and contribute to a family of lipid-gated ion channels.
WIN 55,212-2 is a chemical described as an aminoalkylindole derivative, which produces effects similar to those of cannabinoids such as tetrahydrocannabinol (THC) but has an entirely different chemical structure.
The transient receptor potential cation channel subfamily V member 1 (TRPV1), also known as the capsaicin receptor and the vanilloid receptor 1, is a protein that, in humans, is encoded by the TRPV1 gene. It was the first isolated member of the transient receptor potential vanilloid receptor proteins that in turn are a sub-family of the transient receptor potential protein group. This protein is a member of the TRPV group of transient receptor potential family of ion channels. Fatty acid metabolites with affinity for this receptor are produced by cyanobacteria, which diverged from eukaryotes at least 2000 million years ago (MYA). The function of TRPV1 is detection and regulation of body temperature. In addition, TRPV1 provides a sensation of scalding heat and pain (nociception). In primary afferent sensory neurons, it cooperates with TRPA1 to mediate the detection of noxious environmental stimuli.
TRPV is a family of transient receptor potential cation channels in animals. All TRPVs are highly calcium selective.
The nociceptin opioid peptide receptor (NOP), also known as the nociceptin/orphanin FQ (N/OFQ) receptor or kappa-type 3 opioid receptor, is a protein that in humans is encoded by the OPRL1 gene. The nociceptin receptor is a member of the opioid subfamily of G protein-coupled receptors whose natural ligand is the 17 amino acid neuropeptide known as nociceptin (N/OFQ). This receptor is involved in the regulation of numerous brain activities, particularly instinctive and emotional behaviors. Antagonists targeting NOP are under investigation for their role as treatments for depression and Parkinson's disease, whereas NOP agonists have been shown to act as powerful, non-addictive painkillers in non-human primates.
Transient receptor potential cation channel, subfamily A, member 1, also known as transient receptor potential ankyrin 1, TRPA1, or The Wasabi Receptor, is a protein that in humans is encoded by the TRPA1 gene.
Transient receptor potential cation channel subfamily V member 2 is a protein that in humans is encoded by the TRPV2 gene. TRPV2 is a nonspecific cation channel that is a part of the TRP channel family. This channel allows the cell to communicate with its extracellular environment through the transfer of ions, and responds to noxious temperatures greater than 52 °C. It has a structure similar to that of potassium channels, and has similar functions throughout multiple species; recent research has also shown multiple interactions in the human body.
Transient receptor potential cation channel subfamily M (melastatin) member 8 (TRPM8), also known as the cold and menthol receptor 1 (CMR1), is a protein that in humans is encoded by the TRPM8 gene. The TRPM8 channel is the primary molecular transducer of cold somatosensation in humans. In addition, mints can desensitize a region through the activation of TRPM8 receptors.
Transient receptor potential cation channel subfamily M member 3 is a protein that in humans is encoded by the TRPM3 gene.
Transient receptor potential cation channel, subfamily V, member 3, also known as TRPV3, is a human gene encoding the protein of the same name.
N-Arachidonyl glycine receptor, also known as G protein-coupled receptor 18 (GPR18), is a protein that in humans is encoded by the GPR18 gene. Along with the other previously "orphan" receptors GPR55 and GPR119, GPR18 has been found to be a receptor for endogenous lipid neurotransmitters, several of which also bind to cannabinoid receptors. It has been found to be involved in the regulation of intraocular pressure.
Iodoresiniferatoxin (I-RTX) is a strong competitive antagonist of the Transient Receptor Potential Vanilloid 1 (TRPV1) receptor. I-RTX is derived from resiniferatoxin (RTX).
Relief from chronic pain remains a recognized unmet medical need. Consequently, the search for new analgesic agents is being intensively studied by the pharmaceutical industry. The TRPV1 receptor is a ligand gated ion channel that has been implicated in mediation of many types of pain and therefore studied most extensively. The first competitive antagonist, capsazepine, was first described in 1990; since then, several TRPV1 antagonists have entered clinical trials as analgesic agents. Should these new chemical entities relieve symptoms of chronic pain, then this class of compounds may offer one of the first novel mechanisms for the treatment of pain in many years.
Zucapsaicin (Civanex) is a medication used to treat osteoarthritis of the knee and other neuropathic pain. Zucapsaicin is a member of phenols and a member of methoxybenzenes. It is a modulator of transient receptor potential cation channel subfamily V member 1 (TRPV-1), also known as the vanilloid or capsaicin receptor 1 that reduces pain, and improves articular functions. It is the cis-isomer of capsaicin. Civamide, manufactured by Winston Pharmaceuticals, is produced in formulations for oral, nasal, and topical use.
Specialized pro-resolving mediators are a large and growing class of cell signaling molecules formed in cells by the metabolism of polyunsaturated fatty acids (PUFA) by one or a combination of lipoxygenase, cyclooxygenase, and cytochrome P450 monooxygenase enzymes. Pre-clinical studies, primarily in animal models and human tissues, implicate SPM in orchestrating the resolution of inflammation. Prominent members include the resolvins and protectins.
GSK1016790A is a drug developed by GlaxoSmithKline which acts as a potent and selective agonist for the TRPV4 receptor. It has been used to study the role of TRPV4 receptors in the function of smooth muscle tissue, particularly that lining blood vessels, lymphatic system, and the bladder.
AMG-9810 is a drug which acts as a potent and selective antagonist for the TRPV1 receptor. It has analgesic and antiinflammatory effects and is used in scientific research, but has not been developed for medical use. It has high antagonist potency and good bioavailability and pharmacokinetics, and so has been used to study the role of TRPV1 in areas other than pain perception, such as its roles in the brain.
HC-067047 is a drug which acts as a potent and selective antagonist for the TRPV4 receptor. It has been used to investigate the role of TRPV4 receptors in a number of areas, such as regulation of blood pressure, bladder function and some forms of pain, as well as neurological functions.
AMG-517 is a drug which acts as a potent and selective blocker of the TRPV1 ion channel. It was developed as a potential treatment for chronic pain, but while it was an effective analgesic in animal studies it was dropped from human clinical trials at Phase I due to producing hyperthermia as a side effect, as well as poor water solubility. It is still used in scientific research into the function of the TRPV1 channel and its role in pain and inflammation, and has been used as a template for the design of several newer analogues which have improved properties.
SB-705498 is a drug which acts as a potent and selective blocker of the TRPV1 ion channel. It has been evaluated in clinical trials for the treatment of rhinitis and chronic cough.
This article incorporates text from the United States National Library of Medicine, which is in the public domain.