TRPV1 participates in the protective effect of propolis on colonic tissue of ulcerative colitis / 中南大学学报(医学版)

OBJECTIVES@#Ulcerative colitis (UC) is a type of inflammatory bowel disease (IBD) mainly characterized by inflammation, ulceration and erosion of colonic mucosa and submucosa. Transient receptor potential vanilloid 1 (TRPV1) is an important mediator of visceral pain and inflammatory bowel disease. This study aims to investigate the protective effect of water soluble propolis (WSP) on UC colon inflammatory tissue and the role of TRPV1.@*METHODS@#Male SD rats were randomly divided into 6 groups (n=8): a normal control (NC) group, an ulcerative colitis model (UC) group, a low-WSP (L-WSP) group, a medium-WSP (M-WSP) group, a high-WSP (H-WSP) group, and a salazosulfapyridine (SASP) group. The rats in the NC group drank water freely, and the other groups drank 4% dextran sulfate sodium (DSS) solution freely for 7 d to replicate the ulcerative colitis model. Based on the successful replication of the UC, the L-WSP, M-WSP, and H-WSP groups were given 50, 100, and 200 mg/kg of water-soluble propolis by gavage for 7 d, and the SASP group was given 100 mg/kg of sulfasalazine by gavage for 7 d. The body weight of rats in each group was measured at the same time every day, the fecal traits and occult blood were observed to record the disease activity index (DAI). After intragastric administration, the animals were sacrificed after fasted 24 h. Serum and colonic tissue were collected, and the changes of MDA, IL-6 and TNF-α were detected. The pathological changes of colon tissues were observed by HE staining, and the expression of TRPV1 in colon tissues was observed by Western blotting, immunohistochemistry, and immunofluorescence.@*RESULTS@#The animals in each group that drank DSS freely showed symptoms such as weight loss, decreased appetite, depressed state, and hematochezia, indicating that the model was successfully established. Compared with the NC group, DAI scores of other groups were increased (all P<0.05). MDA, IL-6, TNF-α in serum and colon tissues of the UC group were increased compared with the NC group (all P<0.01), and they were decreased after WSP and SASP treatment (all P<0.01). The results of showed that the colon tissue structure was obviously broken and inflammatory infiltration in the UC group, while the H-WSP group and the SASP group significantly improved the colon tissue and alleviated inflammatory infiltration. The expression of TRPV1 in colon tissues in the UC group was increased compared with the NC group (all P<0.01), and it was decreased after WSP and SASP treatment.@*CONCLUSIONS@#WSP can alleviate the inflammatory state of ulcerative colitis induced by DSS, which might be related to the inhibition of inflammatory factors release, and down-regulation or desensitization of TRPV1.

Mechanism of Aconiti Kusnezoffii Radix Processed with Chebulae Fructus Against H9c2 Cardiomyocyte Toxicity Based on TRPV1 Channel / 中国实验方剂学杂志

ObjectiveTo explore the role of transient receptor potential vanilloid 1 （TRPV1） channel in reducing cardiomyocyte toxicity of Aconiti Kusnezoffii Radix processed with Chebulae Fructus. MethodH9c2 cardiomyocytes cultured in vitro were used as a model to assess cell viability by methyl thiazolyl tetrazolium （MTT） assay， the expression of TRPV1 mRNA was detected by real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）， and the leakage rate of lactate dehydrogenase （LDH）， the changes of nucleus， reactive oxygen species （ROS）， mitochondrial membrane potential and Ca2+ contents were detected by enzyme linked immunosorbent assay （ELISA）. ResultCompared with the blank group， when the concentration was ≥0.5 g·L-1， the cell viability was significantly decreased （P<0.01）， the leakage rate of LDH， the release of ROS and Ca2+ were increased， the mitochondrial membrane potential was decreased， and the nucleus was pyknosis or even broken in raw Aconiti Kusnezoffii Radix and Aconiti Kusnezoffii Radix processed with Chebulae Fructus groups. When the concentration was ≥0.5 g·L-1， compared with the same mass concentration of raw Aconiti Kusnezoffii Radix group， the cell viability increased significantly （P<0.01）， the leakage rate of LDH， the release of ROS and Ca2+ decreased， the mitochondrial membrane potential increased， and the nuclear morphology improved in Aconiti Kusnezoffii Radix processed with Chebulae Fructus group. Application of the same mass concentration of raw Aconiti Kusnezoffii Radix to H9c2 cardiomyocytes pretreated with the TRPV1 inhibitor BCTC significantly increased cell viability， decreased leakage rate of LDH， ROS and Ca2+ release， increased mitochondrial membrane potential and improved nuclear pyknosis compared with untreated H9c2 cardiomyocytes. Application of the same mass concentration of Aconiti Kusnezoffii Radix processed with Chebulae Fructus to H9c2 cardiomyocytes pretreated with BCTC decreased cell viability， increased LDH leakage rate， ROS and Ca2+ release， reduced mitochondrial membrane potential compared with untreated H9c2 cardiomyocytes. Real-time PCR results showed that both raw Aconiti Kusnezoffii Radix and Chebulae Fructus decoction could increase the expression of TRPV1 mRNA in cardiomyocytes in a concentration dependent manner. ConclusionRaw Aconiti Kusnezoffii Radix can induce cardiomyocyte apoptosis and cardiotoxicity by activating TRPV1 channel， while Aconiti Kusnezoffii Radix processed with Chebulae Fructus can attenuate the toxicity through TRPV1 channel， which may be related to the synergistic effect of acid components in Chebulae Fructus and alkaloids in Aconiti Kusnezoffii Radix on TRPV1 channel.

Exploration on effect mechanism of Miao medicinal acupuncture therapy in treatment of knee osteoarthritis based on TRPV ion channel / 中国针灸

OBJECTIVE@#To observe the effect of Miao medicinal acupuncture therapy on transient receptor potential vanilloid (TRPV) channel in knee joint synovial tissue of the rabbits with knee osteoarthritis (KOA) model and to explore the mechanism of Miao medicinal acupuncture therapy in treatment of KOA.@*METHODS@#Of 34 New Zealand male rabbits, 6 rabbits were selected randomly as the normal group. KOA model was established in the rest rabbits by injecting a mixture of papain and L-cysteine in right knee joints. The 24 successfully modeled rabbits were randomized into a model group, a Miao medicinal acupuncture therapy group, a dermal needle group and a smearing group, 6 rabbits in each one. In the Miao medicinal acupuncture therapy group, Miao medicinal acupuncture therapy was adopted, in which, the roller type of dermal needle was used on the surface of right knee joint [a rectangle shape formed by "Xuehai" (SP 10), "Liangqiu" (ST 34), "Yanglingquan" (GB 34) and "Yinlingquan" (SP 9)], rolling in a " shape, on which, Miao medicinal solution was smeared in advance. In the dermal needle group, the rolling stimulation was exerted on the right the right knee joint surface with the roller type of dermal needle. In the smearing group, Miao medicinal solution was smeared on the right knee joint surface. The intervention was given once every two days, 3 times weekly and the intervention was exerted consecutively for 4 weeks. Successively, on day 1, 21, 28, 35, 42 and 49 of experiment, paw withdrawal threshold (von Frey threshold) after mechanical stimulation was detected in the rabbits. HE staining was adopted to observe the histomorphological changes of the right knee joint cartilage in the rabbits. ELISA was used to determine the contents of interleukin-1 (IL-1β) and tumor necrosis factor-α (TNF-α) in the right knee synovial fluid. Western blot method and real-time PCR were used to determine the relative expressions of protein and mRNA of TRPV1 and TRPV4 in knee synovial tissue of the rabbits.@*RESULTS@#Compared with the normal group, on day 49 of experiment, von Frey threshold was reduced significantly in the rabbits of the model group (@*CONCLUSION@#Miao medicinal acupuncture therapy plays a role in treatment of KOA probably through inhibiting the expressions of IL-1β and TNF-α of knee synovial fluid and down-regulating the expressions of protein and mRNA of TRPV1 and TRPV4 in knee synovial tissue.

Effect of small dose capsaicin for treatment of pulmonary fibrosis in mice and its mechanism / 中国应用生理学杂志

To observe whether the mechanism of small dose capsaicin (Cap) against pulmonary fibrosis in mouse is mediated by agitating transient receptor potential vanilloid 1 (TRPV1). Methods: A total of 60 BALB/c mice were randomly divided into control (CON) group, bleomycin (BLM)group, Cap (0.5, 1,2 mg/kg) groups and Cap (2 mg/kg) plus SB-452533 (2.5 mg/kg) group. C57BL/6 mice were intratracheally injected with 3.5 mg/kg BLM to induce pulmonary fibrosis model. Animals for drugs treatment received daily drug via subcutaneous injection for 21 days. The morphological changes and collagen deposition in lung tissues were analysed by HE staining, Masson staining and immunohistochemistry. The concentration of calcitonin gene-related peptide (CGRP) in plasma was determined by ELISA. The mRNA and (or) proteins levels of α-CGRP, β-CGRP, collagen I, collagen III, E-Cadherin, zonula occludens-1 (ZO-1), vimentin, alpha smooth muscle actin (α-SMA), TRPV1, p-ERK1/2 and eukaryotic initiation factor 3a (eIF3a) were detected by qPCR and (or) Western blot. Compared with the BLM group, small dose Cap significantly reduced bleomycin-induced pulmonary fibrosis in mice and obviously reversed alveolar epithelial cells epithelial-mesenchymal transition (EMT) (the expression of E-cadherin and ZO-1 were increased(P＜0.05 or P＜0.01)and the expression of α-SMA and Vimentin were decreased (P＜0.05 or P＜0.01) after drugs treatment for 21 day, concomitantly with the increase the expressions of TRPV1 and CGRP (P＜0.05 or P＜0.01), and inhibiting ERK1/2 phosphorylation and eIF3a expression (P＜0.05 or P＜0.01). These effects of small dose Cap were abolished in the presence of TRPV1 receptor antagonist SB-452533. The results suggest that small dose Cap can reverse alveolar epithelial cells EMT and alleviate bleomycin-induced pulmonary fibrosis in mice by inhibiting ERK1/2/eIF3asignaling pathway, which is related to agitating TRPV1 receptor and releasing of CGRP.

Inhibitory effect of activation of cardiac TRPV1 receptors on cardiovascular activity in rats / 吉林大学学报(医学版)

Objective: To investigate the cardiovascular reflex induced by the activation of cardiac transient receptor potential vanillic acid receptor 1(TRPV1), the central location of reflex and its peripheral neurotransmitters of the rats, and to elucidate the central and peripheral neural mechanisms of cardiovascular reflex mediated by TRPV1 receptor. Methods: A total of 60 healthy male SD rats were randomly divided into control group, ido-RTX group, atropine group, immunofluorescence group and nerve tract tracking group; there were 12 rats in each group. Pericardial intubation was performed in the rats in various groups after anesthesia. The changes of heart rates and blood pressures of the rats in control group, ido-RTX group and atropine group were observed by arterial intubation. The tissue samples were collected 1 h after intropericardial injection of capsaicin in imunofluorescence group, and the co-expression of c-Fos positive neurons induced by capsaicin and cholinesterase positive neurons in the medulla oblongata was observed by immunofluorescence technigue. Intraopericardial injected carbonyl cyanine fluorescent dye (Dil) was used as retrograde tracer in nerve tract group, and the distribution of Dil positive cells in the medulla oblongata was observed by fluorescence microscope 1 week later. Results: The blood pressure and heart rate of the rats in control group were decreased significantly after intrapericardial injection of capsaicin of the rats in control group (P0. 05); after intrapericardial injection of capsaicin, the number of c-Fos positive neurons in nucleus tractus solitarii, dorsal motor nucleus of vagus and nucleus ambiguous of medulla oblongata was increased significantly (P<0. 05); most of these neurons were cholinesterase positive neurons; after intrapericardial injection of Dil, a large number of red fluorescent labeled neurons and nerve endings appeared in the nucleus tractus solitarii, dorsal motor nucleus of vagus and nucleus ambiguous. Conclusion: Intrapericardial injection of capsaicin can selectively activate the TRPV1 receptors in the heart, increase the excitability of cholinergic neurons in the cardiovascular center of the medulla oblongata, increase the peripheral release of acetylcholine, and produce an inhibitory effect on the cardiovascular activity by activating the M receptor.

Adrenaline, transient receptor potential vanilloid 1 channel and substance P in rats with acute spinal cord injury complicated with lung injury / 第二军医大学学报

ObjectiveTo study the changes and significance of adrenaline, transient receptor potential vanilloid 1 (TRPV1) channel and substance P in rats with acute spinal cord injury (ASCI) complicated with lung injury. Methods Two hundred and twenty eight female Sprague-Dawley rats were randomly divided into sham operation group (sham group, n=90), ASCI group (n=108), bilateral adrenalectomy group (n=15), and ASCI after bilateral adrenalectomy group (n= 15). The ASCI model was established on the T10 spinal cord segment using a modified Allen's strike model (10 g, 25 mm). The sham group only exposed the T10 spinal cord, and the ASCI after bilateral adrenalectomy group was established 5 days after bilateral adrenalectomy. High-performance liquid chromatography was used to detect the changes of serum adrenaline. The pulmonary tissue specimens were collected from rats. Wet-to-dry lung weight ratio was used to detect the changes of pulmonary edema, and H-E staining was used to detect the pathological changes of lung tissue. The expression of TRPV1 protein in lung tissue was detected by immunohistochemistry and Western blotting. The contents of substance P in the lung tissue were detected by enzyme-linked immunosorbent assay. Results Serum adrenaline levels in the ASCI group were significantly higher than those in the sham group at 2, 6, 12, 24, 48, and 72 h after spinal injury (all P<0.01). The pulmonary edema and lung injury gradually aggravated in the ASCI group at 24, 48 and 72 h after spinal injury, and began to recover at 1 week. The expression levels of TRPV1 protein and substance P contents in ASCI group were significantly upregulated compared with the sham group at 24, 48, and 72 h after spinal injury (all P<0.05, P<0.01). The edema of lung tissue and pathological injury in the ASCI after bilateral adrenalectomy group were alleviated compared with the ASCI group 72 h after spinal injury. Conclusion Adrenaline may involve in the pathogenesis of pulmonary edema and lung injury in rats with ASCI, which may be related to the upregulation of TRPV1 and P substance expression. The pulmonary edema and lung injury after ASCI can be alleviated by adrenalectomy.

In vitro study of effects of transient receptor potential vanilloid 1 on autophagy in early hypoxic mouse cardiomyocytes and the mechanism / 中华烧伤杂志

Objective@#To explore the effects of transient receptor potential vanilloid 1 (TRPV1) on autophagy in early hypoxic mouse cardiomyocytes and the mechanism in vitro.@*Methods@#The hearts of 120 C57BL/6 mice aged 1-2 days, no matter male or female, were isolated, and then primary cardiomyocytes were cultured and used for the following experiments, the random number table was used for grouping. (1) The cells were divided into normoxia group and hypoxia 3, 6, and 9 h groups, with one well in each group. The cells in normoxia group were routinely cultured (the same below), the cells in hypoxia 3, 6, and 9 h groups were treated with fetal bovine serum-free and glucose-free Dulbecco′ s modified Eagle medium under low oxygen condition in a volume fraction of 1% oxygen, 5% carbon dioxide, and 94% nitrogen for 3, 6, and 9 h, respectively. The protein expressions of microtubule-associated protein 1 light chain 3 (LC3), Beclin-1, TRPV1 were determined with Western botting. (2) The cells were divided into normoxia group and hypoxia group, with two coverslips in each group. The cells in hypoxia group were treated with hypoxia for 6 h as above. The positive expression of TRPV1 was detected by immunofluorescence assay. (3) The cells were divided into 4 groups, with one well in each group. The cells in simple hypoxia group were treated with hypoxia for 6 h as above, and the cells in hypoxia+ 0.1 μmol/L capsaicin group, hypoxia+ 1.0 μmol/L capsaicin group, and hypoxia+ 10.0 μmol/L capsaicin group were respectively treated with 0.1, 1.0, 10.0 μmol/L capsaicin for 30 min before hypoxia for 6 h. The protein expressions of LC3, Beclin-1, and TRPV1 were detected by Western blotting. (4) The cells were divided into 5 groups, with 5 wells in each group. The cells in hypoxia group were treated with hypoxia for 6 h as above, the cells in hypoxia+ chloroquine group, hypoxia+ capsaicin group, and hypoxia+ capsaicin+ chloroquine group were treated with hypoxia for 6 h after being cultured with 50 μmol/L chloroquine, 10.0 μmol/L capsaicin, and 50 μmol/L chloroquine+ 10.0 μmol/L capsaicin for 30 min, respectively. Viability of cells was detected by cell counting kit 8 assay. (5) The cells were divided into simple hypoxia group and hypoxia+ 10.0 μmol/L capsaicin group, with one well in each group. The cells in hypoxia group were treated with hypoxia for 6 h as above, the cells in hypoxia+ 10.0 μmol/L capsaicin group were treated with 10.0 μmol/L capsaicin for 30 minutes and then with hypoxia for 6 h. The protein expressions of lysosomal associated membrane protein 1 (LAMP-1) and LAMP-2 were detected by Western blotting. Each experiment was repeated for 3 or 5 times. Data were processed with one-way analysis of variance, least significant difference t test, and Bonferroni correction.@*Results@#(1) Compared with those of normoxia group, the protein expressions of LC3, Beclin-1, and TRPV1 were significantly increased in cardiomyocytes of hypoxia 3, 6, and 9 h groups (t3 h=4.891, 5.890, 4.928; t6 h=9.790, 6.750, 10.590; t9 h=6.948, 6.764, 5.049, P<0.05 or P<0.01), which of hypoxia 6 h group were the highest (1.08±0.05, 1.12±0.10, 0.953±0.071, respectively). (2) The density of TRPV1 in cell membrane and inside the cardiomyocytes in hypoxia group was significantly increased with lump-like distribution, and the expression of TRPV1 was higher than that in normoxia group. (3) Compared with those of simple hypoxia group, the protein expression of Beclin-1 in cardiomyocytes of hypoxia+ 0.1 μmol/L capsaicin group was increased (t=10.488, P<0.01), while the protein expressions of LC3 and TRPV1 were increased without statistically significant differences (t=4.372, 3.026, P>0.05); the protein expressions of LC3, TRPV1, and Beclin-1 in cardiomyocytes of hypoxia+ 1.0 μmol/L capsaicin group and hypoxia+ 10.0 μmol/L capsaicin group were significantly increased (t=15.505, 5.773, 13.430; 20.915, 8.054, 16.384; P<0.05 or P<0.01), which of hypoxia+ 10.0 μmol/L capsaicin group were the highest (2.33±0.09, 1.34±0.07, 1.246±0.053, respectively). (4) Compared with 0.585±0.045 in normoxia group, the cardiomyocyte viability in hypoxia group was significantly decreased (0.471±0.037, t=4.365, P<0.05). Compared with that in hypoxia group, the cardiomyocyte viability in hypoxia+ chloroquine group was further decreased (0.350±0.023, t=6.216, P<0.01), while 0.564±0.047 in hypoxia+ capsaicin group was significantly increased (t=3.489, P<0.05). Compared with that in hypoxia+ chloroquine group, the cardiomyocyte viability in hypoxia+ capsaicin+ chloroquine group did not significantly change (0.364±0.050, t=0.545, P>0.05). (5) Compared with 0.99±0.04 and 0.54±0.04 in simple hypoxia group, the protein expressions of LAMP-1 and LAMP-2 in hypoxia+ 10.0 μmol/L capsaicin group were significantly increased (1.49±0.06, 0.81±0.05, t=12.550, 7.442, P<0.01).@*Conclusions@#TRPV1 can further promote the expression of autophagy-related proteins in hypoxic cardiomyocytes through autophagy-lysosomal pathway, enhance autophagy activity, and improve autophagic flow for alleviating early hypoxic cardiomyocyte injury.

Effect of Genkwa Flos on Transient Receptor Potential Vanilloid 1 of Thermosensitive Channel / 中国实验方剂学杂志

Objective:To study the effect of Genkwa Flos on the thermosensitive channel, transient receptor potential vanilloid 1 (TRPV1) by electrophysiological whole cell patch clamp technique and animal behavior experiment, in order to explore its mechanism. Method:The whole-cell patch clamp technique was used to measure transmembrane currents induced by 75%ethanol extract from different concentrations of Genkwa Flos in HEK293 cells that expressed human TRPV1.TRPV1 specific antagonist capsaicin was used to observe whether it could inhibit the transmembrane current induced by Genkwa Flos. Totally 30 C57BL/6 mice were taken for behavioral detection, and divided into blank group (6 mice), high-dose group (6 mice), medium-dose group (6 mice), low-dose group (6 mice) and ibuprofen positive control group (6 mice). Genkwa Flos treatment group was given low dose (0.195 g·kg-1·d-1), medium dose (0.39 g·kg-1·d-1) and high dose (0.78 g·kg-1·d-1) by gavage. One hour later, the changes of behavioral latency of cold pain and hot pain in mice were observed in cold plate at (0±2)℃ and hot plate at (55±1)℃. Result:Whole cell patch clamp experiment showed that 75%ethanol extract of Genkwa Flos in hTRPV1/HEK293 cells could activate TRPV1 channel to generate obvious transmembrane current, which was similar with that generated by the known TRPV1 agonist capsaicin in current density and current-voltage relationship. The dose-effect experiments showed that compared with extracellular fluid, 10 g·L-1 ethanol extract of Genkwa Flos could activate hTRPV1/HEK293 cells to induce significant transmembrane current (P-1 ethanol extract of Genkwa Flos was more than 3 g·L-1(P-1 ethanol extract of Genkwa Flos. In the experiment of cold plate and hot plate in mice, there was a dose-effect relationship between the latencies of cold pain behavior and hot pain behavior in mice prolonged by Genkwa Flos. In the experiment of cold plate, compared with the blank group, the cold pain behavior latency of mice in the medium-dose group was significantly prolonged (PPPPPConclusion:More than one TRPV1 agonist was included in 75%ethanol extract of Genkwa Flos. The warm, analgesic and anti-inflammatory effects of Genkwa Flos may be a series of effects after activation of TRPV1.

Transient receptor potential type vanilloid 1 regulates EGFR related functions in pancreatic cancer cells / 药学实践杂志

Objective To evaluate the regulation of the TRPV1 receptor on the expression of EGFR protein and the effects on related cell functions.Methods Human pancreatic cancer cells PANC-1 were cultured and treated by over-expression and siRNA.Cell proliferations were detected by CCK-8 experiment.RT-PCR test was used to detect the expression of onco-genes Akt2 and K-ras.Results EGFR protein was down-regulated by TRPV1 over-expression or by agonist activation in pan-creatic cancer cells.EGFR protein was increased by the interference of TRPV 1 expression.The proliferation rate of pancreatic cancer cells was decreased and Akt2,K-ras were significantly inhibited by TRPV1 over-expressing.Conclusion The expres-sion of TRPV1 in pancreatic cancer cells regulated the EGFR protein content.The cell proliferation and oncogene expression were inhibited by TRPV1 over-expressing.

Effects of capsaicin on cognitive function and expression of TRPV1 protein in hippocampus of rats with chronic cerebral hypoperfusion / 中华行为医学与脑科学杂志

Objective To investigate the effect of capsaicin on cognitive function and the expression of TRPV1 protein in hippocampus of rats with chronic cerebral hypoperfusion (CCH).Methods 60 SD rats were randomly divided into control group (SHAM group),chronic cerebral hypoperfusion group (CCH group),placebo control group(PC group) and capsaicin group(CAP group) with 15 in each group.The chronic cerebral hypoperfusion rat model was established by permanent bilateral common carotid artery occlusion.The rats in CAP group and PC group were given capsaicin and saline respectively by intraperitoneal injection,twice a week.The spatial learning and memory ability and emotion of rats were observed by Morris water maze test and open field test,and the expression of TRPV1 in the hippocampus of rats was detected by Western blot.Results (1) In the open field experiment,compared with the SHAM group (22.60±4.60),the standing times of the CCH group(12.10±2.80) decreased (P＜0.01),but the standing times of CAP group (19.30± 4.16) increased compared with that of h PC group(12.50 ±2.68) (P＜0.01).(2) In Morris water maze test,positioning navigation experiment showed that compared with the SHAM group,the escape latency of the CCH group and the PC group increased (P＜0.05),while the escape latency of CAP group was shorter than that of the PC group (P＜ 0.05).And in the space exploration experiment,compared with the SHAM group (1.87 ± 0.64),the times of crossing the platform in CCH group (0.75 ± 0.89) and the PC group (1.00± 0.93) decreased,while the latency of crossing the platform increased (P＜0.01).And the times of crossing the platform in CAP group((2.38±0.74) increased compared with that of PC group,and the latency of crossing the platform of CAP group decreased compared with that of PC group (P＜0.01).(3) Results of Western blot showed that compared with the SHAM group,the level of TRPV1 in rat hippocampus of CCH group was down regulated (P＜0.05),and the expression of TRPV1 in CAP group was higher than that of PC group (P＜0.05).Conclusion Capsaicin can effectively improve cognitive impairment in rats with chronic cerebral hypoperfusion,which may be related to the up-regulation of TRPV1 protein expression in hippocampal tissues.

Expressions of TRPV1 and TRPA1 in the dorsal root ganglion in the rat model of orchialgia / 中华男科学杂志

Objective@#To explore the expressions of transient receptor potential vanilloid 1 (TRPV1) and TRP ankyrin 1 (TRPA1) in the dorsal root ganglion (DRG) and their action mechanisms in the rat model of orchialgia.@*METHODS@#The models of orchialgia were established in male SD rats by injection of 2% acetic acid into the testis. Then the number of spontaneous pain responses and withdrawal latency in the model rats were recorded by behavioral tests and the expressions of TRPV1 and TRPA1 in T13－L1 DRGs determined by RT-qPCR, Western blot and immunofluorescence staining.@*RESULTS@#Compared with the normal control rats, the orchialgia models showed a significant increase in the number of spontaneous pain responses (0.13 ± 0.35 vs 22.63 ± 3.42, P<0.01) and a decrease in the withdrawal latency at 4 hours after injection (［12.75 ± 1.50］ vs ［4.85 ± 1.00］ s, P<0.05). The mRNA expressions of both TRPV1 and TRPA1 were observed in the membrane of the neurons in the DRG, the former increased by 1.77 times and the latter by 1.75 times that of the control (P<0.05).@*CONCLUSIONS@#The expressions of TRPV1 and TRPA1 were up-regulated in the DRG of the rat models of orchialgia, which may be involved in the allodynia and hyperalgesia of the rats.

Neuroprotective effect of therapeutic hypothermia induced by dihydrocapsaicin on cerebral ischemia reperfusion injury in mice / 新乡医学院学报

Objective To investigate the neuroprotective effect and its mechanism of therapeutic hypothermia induced by dihydrocapsaicin (DHC) on cerebral ischemia reperfusion injury in mice.Methods Twenty adult wild type (WT) mice were randomly divided into WT group and WT + DHC group,ten mice in each group.Twenty transient receptor potential receptor 1 (TRPV1) knockout mice were randomly divided into TRPV1 KO group and TRPV1 KO + DHC group,ten mice in each group.The model of focal cerebral ischemia reperfusion injury was established in all mice.The mice in the WT group and TRPV1 KO group were subcutaneously injected with physiological saline 1.25 mg · kg-1 · h-1 after reperfusion.The mice in the WT + DHC group and TRPV1 KO + DHC group were subcutaneously injected with DHC 1.25 mg · kg-1 · h-1 after reperfusion.All the mice were moved into the cage at 22 degrees centigrade after 90 minutes of reperfusion.The core body temperature during the reperfusion period was recorded in every 5 minutes to 24 hours after reperfusion.The neurobehavioral score was performed before anesthesia and 24 hours after anesthesia.After the neurobehavioral test,the brain tissue sections of mice were stained with 2,3,5-triphenyltetrazolium chloride;and the infarction rate of the brain tissue was calculated.Results There was no significant difference in the core body temperature among the four groups at 0,30 and 60 minutes after reperfusion (P ＞ 0.05).There was no significant difference in the core body temperature between 90 minutes and 0,30 and 60 minutes after reperfusion (P ＞ 0.05);but the core body temperature at 2,3,4,6,12 and 24 hours after reperfusion was significantly lower than that at 0,30,60 and 90 minutes after reperfusion in WT group,TRPV1 KO group and TRPV1 KO + DHC group(P ＜ 0.05).There was no significant difference in the core body temperature among the WT group,TRPV1 KO group and TRPV1 KO + DHC group at 2,3,4,6,12 and 24 hours after reperfusion (P ＞ 0.05).The core body temperature at 90 minutes and 2,3,4,6,12,24 hours after reperfusion was significantly lower than that at 0,30 and 60 minutes after reperfusion in WT + DHC group(P ＜ 0.05);and the core body temperature in WT + DHC group was significantly lower than that in WT group,TRPV1 KO group and TRPV1 KO + DHC group at the same time point(P ＜ 0.05).There was no significant difference in the total neurobehavioral score among the four groups before anesthesia (P ＞ 0.05).The total neurobehavioral score at 24 hours after reperfusion was significantly lower than that before anesthesia in the four groups (P ＜ 0.05).The total neurobehavioral score in WT + DHC group was significantly higher than that in WT group,TRPV1 KO group and TRPV1 KO + DHC group at 24 hours after reperfusion(P ＜0.05).There was no significant difference in the total neurobehavioral score among WT group,TRPV1 KO group and TRPV1 KO + DHC group at 24 hours after reperfusion (P ＞ 0.05).There was no significant difference in the score of spontaneous activity,climbing test,body proprioception and response to vibrissae touch among the four groups at 24 hours after reperfusion (P ＞ 0.05).The score of symmetry test of limbs movement and forepaw stretching test in WT + DHC group was significantly higher than that in WT group,TRPV1 KO group and TRPV1 KO + DHC group at 24 hours after reperfusion(P ＜ 0.05).There was no significant difference in the score of symmetry test of limbs movement and forepaw stretching test among the WT group,TRPV1 KO group and TRPV1 KO + DHC group at 24 hours after reperfusion (P ＞ 0.05).The infarction rate of brain tissue in WT + DHC group was significantly lower than that in the other three groups at 24 hours after reperfusion (P ＜ 0.05);but there was no significant difference in the infarction rate of brain tissue among the WT group,TRPV1 KO group and TRPV1 KO + DHC group (P ＞ 0.05).Conclusion Subcutaneous injection of DHC after focal cerebral ischemia and repeffusion of mice can induce therapeutic hypothermia by activating TRPV1 receptor,and reduce brain tissue damage and improve neurological function.

Impacts of Volatile Oil from Portulaca Oleracea L.on the Inner Cellular Signaling of Itch Model Stimulated by Capsaicine / 世界科学技术-中医药现代化

This study aimed to explore the mechanism of volatile oil from purslane in treating itch induced by eczema through establishing the itch model,stimulating the keratinocyte with capsaicine (CAP).SD rats were divided into the control group,the model group,the high dose group of volatile oil from purslane,and low dose group of volatile oil from purslane.After finishing the experiment,the morphology of keratinocytes was observed by immunofluorescence technique,while Ca2+ concentration was detected by flow cytometry,and the contents of leukotriene A4 methyl ester (LTA4),interleukin-31 (IL-31) and hydroxy trptamine H1 (HTH1) were quantified by ELISA assay.The expression of TRPV1 mRNA in keratinocytes was tested by RT-PCR,while the protein level of TRPV1 was quantified by western blot.Compared with the model group,it was found that the cell count of positive keratinocytes,the Ca2+ concentration,the levels of LTA4,IL-31 and HTH1,and the mRNA and protein expressions of TRPV1 in the high dose and low dose groups were significantly decreased (P ＜ 0.05).In conclusion,it was demonstrated that the volatile oil from purslane may relieve itch through inhibiting the activation of TRPV1 and reducing secondary inflammatory reaction.

The antagonist of TRPV1 attenuates cytotoxicity of DRG neurons induced by lidocaine / 临床麻醉学杂志

Objective To determine whether or not capsazepine(CPZ),a transient receptor po-tential vanilloid-1(TRPV1)antagonist,attenuates lidocaine-induced cytotoxicity on rat dorsal root ganglion (DRG)neurons in vitro.Methods Adequate DRG neurons from 3-day neonatal Wistar rats were obtained,cultured and purified in vitro.To achieve higher cell viability,we reduced the concen-tration of trypsin to 0.125% compared with others.The purified DRG neurons were incubated with 0,2.5,5,10,20 and 40 mmol/L lidocaine for 10 min,respectively,their viabilities were examined using Cell Counting Kit(CCK-8)assay,and the lethal concentration 50(LC50 )of lidocaine on DRG neurons was calculated.Then,the variation of lidocaine-induced cell viability at LC50 ,when 0,1,10 and 100 μmol/L CPZ were respectively added to the incubations,was examined with CCK-8 assay. Results The purified percentage of DRG neurons was as high as 91% after digesting by 0.125%trypsin and purifying in vitro.Cell viability of DRG neurons in group L1,L2,L3,L4,L5 was signifi-cantly down regulated compared with the control group,to be specific,that of L3,L4,L5 being re-markably lower than that of L1,that of L4,L5 lower than that of L2 and that of L5 lower than that L3 and L4.After lidocaine induced DRG neurons for 10 min,LC50 was 30 mmol/L;10 μmol/L and 100 μmol/L CPZ significantly reduced LC50 DRG neuron toxicity induced by lidocaine (P <0.05). The effect of 10 μmol/L CPZ had reached the maximal effect,decreasing the cell viability decrease from 50% to 35%.Conclusion The novel method in this experiment is effective to obtain good DRG neurons,the LC50 of lidocaine on rat DRG neurons is 30 mmol/L,and CPZ attenuates the cytotoxicity induced by lidocaine on rat DRG neurons.

The Effects of UrsoIic Acid on CispIatin-Induced Expression of Transient Receptor PotentiaI VaniIIoid 1 in Mouse CochIea / 听力学及言语疾病杂志

Objective To investigate the effects of ursolic acid (UA) on cisplatin (CDDP)-induced expres_sion of transient receptor potential vanilloid 1 (TRPV1) in mouse cochlea .Methods Sixty BALB/c mice were ran_domly divided into 4 groups (15 mice in each group) and received introperitoneal injection once daily for 5 days:Control group (normol saline) ,UA group (80 mg/kg/day) ,CDDP group (4 .5 mg/kg/day) ,and CDPP (4 .5 mg/kg/day) plus UA group (80 mg/kg/day) .The expression of TRPV1 in mouse cochlea was determined by immuno_histochemistry ,microscope image analysis and western blot ,and auditory thresholds were evaluated by auditory brainstem response (ABR) measurement .ResuIts The expression of cochlea TRPV1 and ABR threshold shift was significantly increased in the mice treated with CDDP (P0 .7 , P<0 .05) .ConcIusion UA effectively attenuated CDDP -induced ototoxicity and improved auditory function through inhibition of TR_PV1 .

Increase of TRPV1-Immunoreactivity in Dorsal Root Ganglia Neurons Innervating the Femur in a Rat Model of Osteoporosis

PURPOSE: Transient receptor potential vanilloid 1 (TRPV1) is a ligand-gated nonselective cation channel, which can be activated by capsaicin and other noxious stimuli. Recently, an association between bone pain and TRPV1 has been reported. However, the influence of osteoporosis on TRPV1 in the sensory system innervating the femur has not been reported. MATERIALS AND METHODS: TRPV1-immunoreactive (ir) in dorsal root ganglia (DRG) neurons labeled with neurotracer [Fluoro-Gold (FG)] innervating the femurs of Sprague Dawley rats were examined in control, sham, and ovariectomized (OVX) rats. We evaluated osteoporosis in the femurs and compared the proportion of TRPV1-ir DRG neurons innervating femur between the 3 groups of rats. RESULTS: OVX rats showed osteoporotic cancellous bone in the femur. FG labeled neurons were distributed from L1 to L6 DRG, but there was no significant difference in the proportion of labeled neurons between the 3 groups (p>0.05). The proportions of FG labeled TRPV1-ir DRG neurons were 1.7%, 1.7%, and 2.8% of DRG neurons innervating the femur, in control, sham-operated, and OVX rats, respectively. The proportion of TRPV1-ir neurons in DRG innervating the femur in OVX rats was significantly higher than that in control and sham-operated rats (p<0.05). CONCLUSION: Under physiological conditions, DRG neurons innervating femurs in rats contain TRPV1. Osteoporosis increases the numbers of TRPV1-ir neurons in DRG innervating osteoporotic femurs in rats. These findings suggest that TRPV1 may have a role in sensory perception of osteoporotic femurs.

Transient Receptor Potential Vanilloid 1-Immunoreactive Innervation Increases in Fractured Rat Femur

PURPOSE: Pain from vertebral or femoral neck fractures is a particularly important problem in clinical orthopaedics. Transient receptor potential vanilloid 1 (TRPV1) is a ligand-gated nonselective cation channel, and there are recent reports on an association between bone pain and TRPV1. However, an increase in TRPV1 activity has not been reported following femoral fracture. MATERIALS AND METHODS: We applied a neurotracer [Fluoro-gold (FG)] onto femur to detect dorsal root ganglia (DRGs) innervating the cortex of the femur in 30 Sprague Dawley rats. Seven days after application, a closed mid-diaphyseal fracture of the femur was performed. FG labeled TRPV1-immunoreactive (ir) DRGs innervating the femur were examined in nonfractured controls, and 3 days, 1 week, 2 weeks, and 4 weeks after fracture. We evaluated bone healing of the femur and compared the ratio of TRPV1-ir DRG neurons innervating the femur at the time points. RESULTS: Four weeks after fracture, complete bone union was observed. There was no significant difference in the ratio of FG labeled DRG neurons to total DRG neurons at each time point. The percentages of TRPV1-ir neurons in DRGs innervating the femur at 3 days and 1 week after fracture were significantly higher than those in control, 2 weeks, and 4 weeks after fracture (p<0.05). CONCLUSION: Fracture induced an increase of TRPV1-ir neurons in DRGs innervating the fractured femur within 3 days, and decreased during bone healing over 4 weeks. These findings show that TRPV1 may play a role in sensory sensation of bone fracture pain.

Role of TRPV1 in the Regulation of Gastric Motility by Electroacupuncture / 上海针灸杂志

ObjectiveTo discuss the role of transient receptor potential vanilloid 1 (TRPV 1) in the regulation effect of electroacupuncture on gastric motility.MethodTRPV1 gene knock-out mice (KO mice) and wild-type C57BL/6 mice (WT mice) were selected to receive acupuncture at Zusanli (ST36),Quchi (LI11), Zhongwan (CV12), and Weishu (BL21), and the intragastric pressure was observed before and after acupuncture.ResultElectroacupuncture at Zusanli caused both excitation and inhibition in WT mice, predominated by mild excitation, while electroacupuncture at Weishu, Quchi and Zhongwan all caused inhibition effect; in the KO mice, electroacupuncture at Zusanli, Quchi, Zhongwan, and Weishu all inhibited gastric motility.Conclusion TRPV1 bears certain regulating effect on gastric motility, andacupuncture can inhibit the gastric motility in TRPV gene KO mice.

Effects of capsaicin on oxidative stress in lipopolysaccharide-induced acute lung injury in mice / 中华急诊医学杂志

Objective To investigate the effects of transient receptor potential vanilloid 1 activation by capsaicin on the oxidative stress in lipopolysaccharide-induced lung injury in mice in order to elucidate the potential mechanisms.Methods A total of 108 specific pathogen free (SPF) ICR male mice were randomly divided into six groups:normal control group (n =18),capsaicin control group (CAP control group,n =18),capsazepine control group (CAPZ control group,n =18),acute lung injury group (n =18),capsaicin treatment group (CAP treatment group,n =18) and capsazepine treatment group (CAPZ treatment group,n =18).After modeling,superoxide dismutase (SOD),catalase (CAT) and malondiachehyche (MDA) levels in lung were measured with the method of chromatometry,and the expression of heme oxygenase 1 (HO-1) in lung tissue was assessed with enzyme linked immunosorbent assay (ELISA),while the level of NF-E2-related factor-2 (Nrf2) was determined by western blotting and the expression of Nrf2 mRNA was measured by RTPCR.Pathological changes of lung tissue were observed under light microscope.Results The activities of SOD and CAT in lung tissue at 3,8,16 h were dramatically lower in acute lung injury group than those in normal control group (P ＜ 0.05),while the level of MDA was higher.Compared with acute lung injury group,the lung levels of SOD and CAT at 8 h and 16 h were higher in CAP treatment group (P ＜0.05),while the lung level of MDA was lower (P ＜ 0.05).The levels of SOD and CAT in CAPZ treatment group were decreased at 8 h and 16 h,while the levels of MDA in this group were increased at 3,8,16 h (P ＜0.05).The pulmonary levels of HO-1,Nrf2 and expression of Nrf2 mRNA were significantly higher in acute lung injury group than those in normal control group (P ＜ 0.05).Compared with acute lung injury group,the levels of HO-1,NRF2 and expression of NRF2 mRNA were increased markedly in CAP treatment group (P ＜ 0.05)and were obviously decreased in CAPZ treatment group (P ＜0.05).At 8 h,16 h after modeling,the degree of lung damage was ameliorated in CAP treatment group compared with acute lung injury group under light microscope,while the lung damage was aggravated in CAPZ treatment group.Conclusions The activation of TRPV1 could apparently up-regulate the levels of CAT,SOD,Nrf2,HO-1,and reduce the MDA level in lung tissue of mice with acute lung injury,ultimately protecting the endotoxemia mice from oxidative stress.

Role of transient receptor potential vanilloid 1 channel in pancreatitis / 第二军医大学学报

Transient receptor potential vanilloid 1 (TRPV1) is a non-selective cation channel, which can be activated by multiple pathways during the course of the diseases. Recent studies indicate that primary sensory neurons of the pancreas express TRPV1 receptor and the activation of TRPV1 receptor promotes pancreatic inflammation. Moreover, blockade of these transient receptor potential channels can greatly ameliorate the pain response in experimental pancreatitis.