The transient receptor potential vanilloid 4 (TRPV4) cation channel, a member of the TRP vanilloid subfamily, is expressed in a broad range of tissues where it participates in the generation of Ca2+ signals and/or depolarization of the membrane potential. Regulation of TRPV4 abundance at the cell surface is critical for osmo- and mechanotransduction. Defects in TRPV4 are the cause of several human diseases, including brachyolmia type 3 (MIM:113500) (also known as brachyrachia or spondylometaphyseal dysplasia Kozlowski type [MIM:118452]), and metatropic dysplasia (MIM:156530) (also called metatropic dwarfism or parastremmatic dwarfism [MIM:168400]). These bone dysplasia mutants are characterized by severe dwarfism, kyphoscoliosis, distortion and bowing of the extremities, and contractures of the large joints. These diseases are characterized by a combination of decreased bone density, bowing of the long bones, platyspondyly, and striking irregularities of endochondral ossification with areas of calcific stippling and streaking in radiolucent epiphyses, metaphyses, and apophyses. In this review, we discuss the potential effect of the mutation on the regulation of TRPV4 functions, which are related to human diseases through deviated function. In particular, we emphasize how the constitutive active TRPV4 mutant affects endochondral ossification with a reduced number of hypertrophic chondrocytes and the presence of cartilage islands within the zone of primary mineralization. In addition, we summarize current knowledge about the role of TRPV4 in the pathogenesis of several diseases.
Humans ; *Mutation ; Osteochondrodysplasias/*genetics ; Osteogenesis/genetics ; TRPV Cation Channels/chemistry/*genetics/metabolism

Capsaicin in chili peppers bestows the sensation of spiciness. Since the discovery of its receptor, transient receptor potential vanilloid 1 (TRPV1) ion channel, how capsaicin activates this channel has been under extensive investigation using a variety of experimental techniques including mutagenesis, patch-clamp recording, crystallography, cryo-electron microscopy, computational docking and molecular dynamic simulation. A framework of how capsaicin binds and activates TRPV1 has started to merge: capsaicin binds to a pocket formed by the channel's transmembrane segments, where it takes a "tail-up, head-down" configuration. Binding is mediated by both hydrogen bonds and van der Waals interactions. Upon binding, capsaicin stabilizes the open state of TRPV1 by "pull-and-contact" with the S4-S5 linker. Understanding the ligand-host interaction will greatly facilitate pharmaceutical efforts to develop novel analgesics targeting TRPV1.
Binding Sites ; Capsaicin ; chemistry ; pharmacokinetics ; Humans ; Hydrogen Bonding ; Protein Binding ; TRPV Cation Channels ; chemistry ; genetics ; metabolism

OBJECTIVETo investigate the expression of transient receptor potential melastatin (TRPM) and transient receptor potential vanilloid (TRPV) channel family genes in rat spermatogenic cells.

METHODSRat spermatogenic cells were isolated by a mechanical procedure and the total RNA was extracted using TRIzol reagent. TRPM and TRPV channel family genes were amplified by RT-PCR and the presence of the target genes was detected by agarose gel electrophoresis. The relative gene expression levels were measured by real-time quantitative RT-PCR.

RESULTSTRPV5, TRPM3, TRPM4 and TRPM7 mRNAs were expressed in rat spermatogenic cells, but TRPV1, TRPV2, TRPV3, TRPV4, TRPV6, TRPM1, TRPM2, TRPM5, TRPM6, TRPM7 and TRPM8 mRNAs were not detected. The relative expressions of TRPM and TRPV mRNA were determined by quantitative real-time RT-PCR. TRPM7 expression was the highest among all the TRPM subtypes in rat spermatogenic cells, at a level equivalent to (0.0430-/+0.0034)% of beta-actin expression. TRPM3 and TRPM4 were also highly expressed, but their expression levels were only approximately 56% and 63% of that of TRPM7, respectively. For the TRPV subfamily, only TRPV5 mRNA was abundantly expressed at the level of (0.0157-/+0.0029)% relative to that of beta-actin.

CONCLUSIONTRPV5, TRPM3, TRPM4 and TRPM7 mRNAs were coexpressed in spermatogenic cells in rats, among which TRPM4 and TRPM7 mRNA were expressed at high levels. TRPM4 and TRPM7 channels may be involved in the regulation of growth, differentiation and maturation of rat spermatogenic cells and are associated with the generation of the sperms.

Animals ; Male ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; Spermatocytes ; cytology ; metabolism ; Spermatogonia ; cytology ; metabolism ; TRPM Cation Channels ; genetics ; metabolism ; TRPV Cation Channels ; genetics ; metabolism

OBJECTIVETo study the expression of the mRNAs of transient receptor potential (TRP) gene subfamily TRPV and TRPM in rat testes.

METHODSNormal SD rat testes were collected and the expression of TRPV and TRPM mRNAs were detected by routine RT-PCR.

RESULTSThe TRPV4, TRPV5, TRPV6, TRPM3, TRPM4 and TRPM8 mRNAs were detected in the rat testes, but the other members of TRPV and TRPM family were not detected.

CONCLUSIONSTRPV4, TRPV5, TRPV6, TRPM3, TRPM4 and TRPM8 are expressed in rat testes. This finding provides the basis for exploring the functions of TRPV and TRPM in the testes and the relation between testis diseases and the TRP family.

Animals ; Male ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; TRPM Cation Channels ; genetics ; metabolism ; TRPV Cation Channels ; genetics ; metabolism ; Testis ; metabolism

OBJECTIVETo study the effects of the ingredients from Chinese herbs with the nature of cold or hot on the expression of TRPV1 and TRPM8.

METHODThe effects of ingredients from herbs on primary culture DRG neurons are observed in vitro. The expression quantity of gene is detected by the method of real time PCR. the 2 (-deltadeltaCT) method is applied to analyze the data.

RESULTIngredients from herbs with the nature of cold up-regulate the expression level of TRPV1 and down-regulate that of TRPM8, especially under the temperature condition of 39 degrees C; while ingredients from herbs with the nature of hot up-regulate the expression level of TRPM8 and down-regulated that of TRPV1, which is more significant under the temperature condition of 19 degrees C.

CONCLUSIONThe regulatory changes of TRPV1 and TRPM8 mRNA expression induced by the chemical ingredients might be related to the cold and hot natures of the herbs from which the ingredients are extracted. And this could be one of the therapeutic mechanisms for the treatment of Chinese herbal medicines to cold- and heat-related diseases.

Animals ; Drugs, Chinese Herbal ; administration & dosage ; analysis ; Gene Expression ; drug effects ; Male ; Rats ; Rats, Sprague-Dawley ; TRPM Cation Channels ; genetics ; metabolism ; TRPV Cation Channels ; genetics ; metabolism

This paper was designed in middle cerebral artery occlusion (MCAO) model of rats, to explore the role of transient receptor potential channel 4 (TRPC4) as Ca(2+) selective channel by detecting the changes of the expression of TRPC4 in different parts of cerebral tissues under the condition of focal cerebral ischemia. The rats were sacrificed after MCAO surviving time 6 h, 12 h, 1 d, 3 d. As determined by Western blot, the expressions of TRPC4 in striatum and hippocampus of 12 h, 1 d, 3 d groups were significant higher than that in the control group (P<0.05). Immunohistochemical staining showed that the TRPC4 immunoreactive substances were present in the membrane of neurons. Compared with the control group, immunostaining positive cells increased in hippocampus and striatum of cerebral ischemia groups. The TRPC4 immunostaining positive cells increased significantly in 1d-group and 3d-group (P<0.05). It suggests that as a Ca(2+) selective channel, the variance of the expression of TRPC4 may play a role in acute and delayed neuronal injury in focal cerebral ischemia.
Animals ; Cation Transport Proteins ; biosynthesis ; genetics ; Corpus Striatum ; metabolism ; Hippocampus ; metabolism ; Infarction, Middle Cerebral Artery ; metabolism ; Ion Channels ; biosynthesis ; genetics ; Male ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury ; metabolism ; TRPV Cation Channels

Transient receptor potential vanilloid 1 (TRPV1) is a non-selective positive ion channel that is mainly expressed in sensory neurons and a member of transient receptor potential (TRP) family. The receptor could be activated by mechanical irritation, chemical irritation or endogenous ligand to mediate pains and cause injury to body functions. Traditional Chinese medicine believes that the mechanism of pain is that "stagnation leads to pain". Specifically, both of the contracture and tautness caused by cold and the blood stasis could result in blood impassability and pain. Most of traditional Chinese medicines for clearing heat and removing toxicity have the anti-inflammatory effect, while those for warming interior, and promoting blood circulation to remove blood stasis have the effect in smoothening blood vessels. Therefore, either with the anti-inflammatory effect or the effect in smoothening blood vessels, traditional Chinese medicines for clearing heat and removing toxicity, warming interior, and promoting blood circulation have the analgesic effect In this paper, the authors summarize the analgesic effect of the above three traditional Chinese medicines, with TRPV1 as the target.
Analgesics ; administration & dosage ; Animals ; Drugs, Chinese Herbal ; administration & dosage ; Humans ; Pain ; drug therapy ; genetics ; metabolism ; TRPV Cation Channels ; antagonists & inhibitors ; genetics ; metabolism

Artemin is a neuronal survival and differentiation factor in the glial cell line-derived neurotrophic factor family. Its receptor GFRalpha3 is expressed by a subpopulation of nociceptor type sensory neurons in the dorsal root and trigeminal ganglia (DRG and TG). These neurons co-express the heat, capsaicin and proton-sensitive channel TRPV1 and the cold and chemical-sensitive channel TRPA1. To further investigate the effects of artemin on sensory neurons, we isolated transgenic mice (ARTN-OE mice) that overexpress artemin in keratinocytes of the skin and tongue. Enhanced levels of artemin led to a 20% increase in the total number of DRG neurons and increases in the level of mRNA encoding TRPV1 and TRPA1. Calcium imaging showed that isolated sensory neurons from ARTN-OE mice were hypersensitive to the TRPV1 agonist capsaicin and the TRPA1 agonist mustard oil. Behavioral testing of ARTN-OE mice also showed an increased sensitivity to heat, cold, capsaicin and mustard oil stimuli applied either to the skin or in the drinking water. Sensory neurons from wildtype mice also exhibited potentiated capsaicin responses following artemin addition to the media. In addition, injection of artemin into hindpaw skin produced transient thermal hyperalgesia. These findings indicate that artemin can modulate sensory function and that this regulation may occur through changes in channel gene expression. Because artemin mRNA expression is up-regulated in inflamed tissue and following nerve injury, it may have a significant role in cellular changes that underlie pain associated with pathological conditions. Manipulation of artemin expression may therefore offer a new pain treatment strategy.
Animals ; Hot Temperature ; Hyperalgesia ; metabolism ; Keratinocytes ; physiology ; Mice ; Mice, Transgenic ; Nerve Tissue Proteins ; genetics ; metabolism ; Nociceptors ; physiology ; Skin ; cytology ; TRPA1 Cation Channel ; TRPV Cation Channels ; metabolism ; Tongue ; cytology ; Transient Receptor Potential Channels ; metabolism

We established a cell based high throughput screening model by calcium assay on fluorometric imaging plate reader for finding modulators of TRPV3. The TRPV3 expression vector was transfected into HEK-293 and stable cell line expressing TRPV3 was selected with antibiotics. Upon TRPV3 specific modulators stimulated, pharmacological characteristics of TRPV3 over expression cell line were detected by calcium assay on fluorometric imaging plate reader. Assay conditions were optimized and stability of the model was observed. The reliability and accuracy of application to 96 and 384 well format high throughput screening were also evaluated. A stable HEK-293 cell line highly expressing TRPV3 was established. TRPV3 specific modulators could modulate calcium signal through TRPV3 in dose dependent manner. Optimized screening condition was established by assay development. This model is stable and sensitive, and meets the requirement of high throughput screening by Z'factor validation and Spiking test. This cell model can be applied to screening TRPV3 modulators by calcium assay.
Calcium ; metabolism ; Cell Line ; Humans ; Ion Transport ; Kidney ; cytology ; Membrane Transport Modulators ; metabolism ; Models, Biological ; TRPV Cation Channels ; biosynthesis ; genetics ; Transfection

OBJECTIVETo explore the analgesic effect and action mechanism of electroacupuncture (EA) on gastric ulcer rats with liver-depression syndrome.

METHODSThrough open-field experimental method, 45 qualified SPF-grade male SD rats were selected and divided into a blank group, a model group and an EA group according to random number table method, 15 rats in each group. The model of gastric ulcer rats with liver-depression syndrome was established in the model group and the EA group by using chronic unpredictable stimulation combined with acetic acid burning method. Rats in the blank group did not receive intervention. Rats in the model group were treated with fixation and immobilization for 13 days. Rats in the EA group were treated with EA at "Liangqiu" (ST 34) and "Ganshu" (BL 18); EA voltage was 2 V; disperse-dense wave was selected with 4 Hz of disperse wave and 15 Hz of dense wave, and the intensity of EA was according to the slight vibration of local skin and; muscles; the needles were retained for 20 min, once a day for consecutive 6 days; there was an interval of 1 day' and the treatment was given for 2 weeks. The general condition, open-field experimental result and gastric ulcer index were observed; the western blotting method was applied to measure the expression of vanilloid receptor subtype 1 (VR1) in hypothalamus and gastric antral mucosal, and ELISA method was applied to test the expression of 5-hydroxytryptamine (5-HT) and norepinephrine (NE) in hippocampus.

RESULTSAfter model establishment, the general behavior condition in the model group was inferior to that in the blank group, which was obviously improved after EA. The range of motion in the model group was less than that in the blank group (P<0.01) while that in the EA group was higher than that in the model group (P<0.01). The ulcer inhibition rate was. 54.95%, and the ulcer index in the EA group was lower than that in the model group (P<0.01). Compared with; the blank group, the expression of VR1 in hypothalamus and gastric antral mucosal in the model group was increased (P<0.05); compared with the model group, the expression of VR1 in the EA group was reduced (P<0.05). Compared with the blank group, the expression of 5-HT an NE in hippocampus in the model group was significantly reduced (both P<0.01); compared with the model group, the expression of 5-HT and NE in the EA group was increased (both P<0.01).

CONCLUSIONEA at "Liangqiu" (ST 34) and "Ganshu" (BL 18) has certain analgesic effect in gastric ulcer rats with liver-depression syndrome, which is likely to be related with lowering the contents of VR1 in hypothalamus and gastric antral mucosal and increasing the content of 5-HT and NE in hippocampus.

Acupuncture Analgesia ; Acupuncture Points ; Animals ; Electroacupuncture ; Humans ; Liver ; physiopathology ; Male ; Nociceptive Pain ; genetics ; metabolism ; physiopathology ; therapy ; Rats ; Rats, Sprague-Dawley ; Serotonin ; metabolism ; Stomach Ulcer ; genetics ; metabolism ; physiopathology ; therapy ; TRPV Cation Channels ; genetics ; metabolism