Disseminated intravascular coagulation phenotype is regulated by the TRPM7 channel during sepsis

BACKGROUND: Sepsis is an uncontrolled inflammatory response against a systemic infection that results in elevated mortality, mainly induced by bacterial products known as endotoxins, producing endotoxemia. Disseminated intravascular coagulation (DIC) is frequently observed in septic patients and is associated with organ failure and death. Sepsis activates endothelial cells (ECs), promoting a prothrombotic phenotype contributing to DIC. Ion channel mediated calcium permeability participates in coagulation. The transient reception potential melastatin 7 (TRPM7) non-selective divalent cation channel that also contains an α-kinase domain, which is permeable to divalent cations including Ca2+, regulates endotoxin-stimulated calcium permeability in ECs and is associated with increased mortality in septic patients. However, whether endothelial TRPM7 mediates endotoxemia-induced coagulation is not known. Therefore, our aim was to examine if TRPM7 mediates coagulation during endotoxemia. RESULTS: The results showed that TRPM7 regulated endotoxin-induced platelet and neutrophil adhesion to ECs, dependent on the TRPM7 ion channel activity and by the α-kinase function. Endotoxic animals showed that TRPM7 mediated neutrophil rolling on blood vessels and intravascular coagulation. TRPM7 mediated the increased expression of the adhesion proteins, von Willebrand factor (vWF), intercellular adhesion molecule 1 (ICAM-1), and P-selectin, which were also mediated by the TRPM7 α-kinase function. Notably, endotoxin-induced expression of vWF, ICAM-1 and P-selectin were required for endotoxin-induced platelet and neutrophil adhesion to ECs. Endotoxemic rats showed increased endothelial TRPM7 expression associated with a procoagulant phenotype, liver and kidney dysfunction, increased death events and an increased relative risk of death. Interestingly, circulating ECs (CECs) from septic shock patients (SSPs) showed increased TRPM7 expression associated with increased DIC scores and decreased survival times. Additionally, SSPs with a high expression of TRPM7 in CECs showed increased mortality and relative risk of death. Notably, CECs from SSPs showed significant results from the AUROC analyses for predicting mortality in SSPs that were better than the Acute Physiology and Chronic Health Evaluation II (APACHE II) and the Sequential Organ Failure Assessment (SOFA) scores. CONCLUSIONS: Our study demonstrates that sepsis-induced DIC is mediated by TRPM7 in ECs. TRPM7 ion channel activity and α-kinase function are required by DIC-mediated sepsis-induced organ dysfunction and its expression are associated with increased mortality during sepsis. TRPM7 appears as a new prognostic biomarker to predict mortality associated to DIC in SSPs, and as a novel target for drug development against DIC during infectious inflammatory diseases.

Lianmei Qiwu Decoction relieves diabetic cardiac autonomic neuropathy by regulating AMPK/TrkA/TRPM7 signaling pathway / 中国中药杂志

This study investigated the effect of Lianmei Qiwu Decoction(LMQWD) on the improvement of cardiac autonomic nerve remodeling in the diabetic rat model induced by the high-fat diet and explored the underlying mechanism of LMQWD through the AMP-activated protein kinase(AMPK)/tropomyosin receptor kinase A(TrkA)/transient receptor potential melastatin 7(TRPM7) signaling pathway. The diabetic rats were randomly divided into a model group, an LMQWD group, an AMPK agonist group, an unloaded TRPM7 adenovirus group(TRPM7-N), an overexpressed TRPM7 adenovirus group(TRPM7), an LMQWD + unloaded TRPM7 adenovirus group(LMQWD+TRPM7-N), an LMQWD + overexpressed TRPM7 adenovirus group(LMQWD+TRPM7), and a TRPM7 channel inhibitor group(TRPM7 inhibitor). After four weeks of treatment, programmed electrical stimulation(PES) was employed to detect the arrhythmia susceptibility of rats. The myocardial cell structure and myocardial tissue fibrosis of myocardial and ganglion samples in diabetic rats were observed by hematoxylin-eosin(HE) staining and Masson staining. The immunohistochemistry, immunofluorescence, real-time quantitative polymerase chain reaction(RT-PCR), and Western blot were adopted to detect the distribution and expression of TRPM7, tyrosine hydroxylase(TH), choline acetyltransferase(ChAT), growth associated protein-43(GAP-43), nerve growth factor(NGF), p-AMPK/AMPK, and other genes and related neural markers. The results showed that LMQWD could significantly reduce the arrhythmia susceptibility and the degree of fibrosis in myocardial tissues, decrease the levels of TH, ChAT, and GAP-43 in the myocardium and ganglion, increase NGF, inhibit the expression of TRPM7, and up-regulate p-AMPK/AMPK and p-TrkA/TrkA levels. This study indicated that LMQWD could attenuate cardiac autonomic nerve remodeling in the diabetic state, and its mechanism was associated with the activation of AMPK, further phosphorylation of TrkA, and inhibition of TRPM7 expression.

D. Julius y A. Patapoutian. Premios Nobel de Medicina 2021, descubren nuevos canales iónicos que detectan temperatura y estímulos mecánicos / D. Julius y A. Patapoutian. 2021 Nobel Prize Awardees discover new ionic channels that detect temperature and mechanical stimuli

D. Julius was awarded the 2021 Medicine Nobel prize for the discovery of new cationic channels that detect temperatures either over 40 °C (TRPV1) or cold (TRPM8) ranging from 8-15 °C, followed by the latter identification of other channels that sense temperatures within other ranges. On the other hand, A. Patapoutian shared the 2021 Nobel prize for the independent and simultaneous co-discovery of the TRPM8 cationic channel. Furthermore, Patapoutian iden-tified piezo 1 and 2 channels previously referred to as the cell mechanosensors related to the sense of touch and proprioception. These experimental findings indicate that these novel cationic channels localized in nerve endings of the skin, mouth, lips, bronchial tree, the nephron, plus a variety of tissues transduce phy-sical stimuli into electrical activity that reach the brain sensory cortex to process these stimuli and elicit animal behavior.

Research progress on transient receptor potential melastatin 2 channel in nervous system diseases / 浙江大学学报·医学版

Transient receptor potential M2 (TRPM2) ion channel is a non-selective cationic channel that can permeate calcium ions, and plays an important role in neuroinflammation, ischemic reperfusion brain injury, neurodegenerative disease, neuropathic pain, epilepsy and other neurological diseases. In ischemic reperfusion brain injury, TRPM2 mediates neuronal death by modulating the different subunits of glutamate N-methyl-D-aspartic acid receptor in response to calcium/zinc signal. In Alzheimer's disease, TRPM2 is activated by reactive oxygen species generated by β-amyloid peptide to form a malignant positive feedback loop that induces neuronal death and is involved in the pathological process of glial cells by promoting inflammatory response and oxidative stress. In epilepsy, the TRPM2-knockout alleviates epilepsy induced neuronal degeneration by inhibiting autophagy and apoptosis related proteins. The roles of TRPM2 channel in the pathogenesis of various central nervous system diseases and its potential drug development and clinical application prospects are summarized in this review.

Protective effect of transient receptor potential melastatin 2 inhibitor A10 on oxygen glucose deprivation/reperfusion model / 浙江大学学报·医学版

:To investigate the effect of transient receptor potential melastatin 2 （TRPM2） inhibitor A10 on oxygen glucose deprivation/reperfusion （OGD/R） injury in SH-SY5Y cells．:Human neuroblastoma SH-SY5Y cells were subject to OGD/R injury，and then were divided into blank control group，model control group and A10 group randomly. The cell survival rate was detected by cell counting kit 8 （CCK-8）; the level of cellular reactive oxygen species （ROS） was detected by reactive oxygen detection kit; the mitochondrial membrane potential was detected by tetramethylrhodamine （TMRM） method; the number of apoptotic cells was detected by TUNEL apoptosis assay kit; the protein expression level of cleaved caspase 3 was detected by Western blot．:Compared with 3，20，30，50， has lower cytotoxicity and better inhibition effect on channel activity. Compared with the model control group，ROS level was reduced，the mitochondrial membrane potential was improved，the number of apoptosis cells was reduced ，and the expression of cleaved caspase 3 was significantly reduced in the A10 group（all <0.05）. : A10 can alleviate cell damage after OGD/R by inhibiting TRPM2 channel function，reducing extracellular calcium influx，reducing cell ROS levels，stabilizing mitochondrial membrane potential levels，and reducing apoptosis.

The expression and significance of TRPM8 among chronic rhinosinusitis with nasal polyps / 中华耳鼻咽喉头颈外科杂志

Objective: To compare the expression and difference of melastatin-related transient receptor potential 8(TRPM8) among chronic rhinosinusitis, nasal polyps and normal mucosa tissues. And to explore the significant expression of TRPM8 among CRSwNP. Methods: Fifty-one patients underwent endoscopic sinus surgery in the Department of Otorhinolaryngology Head and Neck Surgery of Renmin Hospital of Wuhan University from February 2019 to January 2020 were recruited, including 33 males and 18 females, aged from 14 to 65 years old (34.55±1.689).Immunohistochemistry was used to detected the expression of TRPM8 protein among CRSsNP(17),CRSwNP (17) and control tissuses(17). In addition, the correlation between the expression of TRPM8 protein in CRSwNP patients and preoperative CT Lund-Mackay scores and preoperative VAS scores and sinonasal outcome test-20 scores was analyzed, respectively. The primary human nasal epithelial cells were cultured in vitro and the expression of TRPM8 was detected by quantitative real-time PCR and western blotting . The tissue in control group, chronic rhinosinusitis without nasal polyps (CRSsNP) group and the CRSwNP group were collected and grinded into tissue homogenized. The expression of TRPM8 protein was detected by western blotting after 24 h stimulation after homogenate was added into the medium of RPMI 2650 and primary nasal epithelial cells. Results: Compared with the control, the expression of TRPM8 was significantly up-regulated in nasal polyps (t=6.852, P<0.05). TRPM8 was mainly expressed in epithelial cells. The expression of TRPM8 in the epithelial cells of CRSsNP had no difference with the control group (t=1.980, P>0.05). In addition, the expression of TRPM8 in CRSwNP patients was positively correlated with the preoperative CT Lund-Mackay scores and VAS scores and SNOT-20 scores (r=0.512, P<0.05;r=0.853, P<0.01;r=0.814, P<0.01). After cultured primary epithelial cells in vitro, the expression level of TRPM8 in epithelial cells derived from nasal polyp was significantly higher than that in control group (t=8.845, P<0.05). By adding the homogenization of control and CRSsNP and CRSwNP tissues, the expression of TRPM8 in RPMI 2650 cells and primary nasal epithelial cells was changed and that was significantly increased after adding the homogenization of the group of CRSwNP. Conclusion: TRPM8 is highly expressed in nasal polyps epithelial cells, suggesting that TRPM8 may be involved in the pathogenesis of nasal polyps regulated by nasal epithelial cells.

Role of transient receptor potential cation channel subfamily M member 2 in hepatic ischemia-reperfusion injury in the mouse and the underlying mechanisms / 中南大学学报(医学版)

OBJECTIVES@#To investigate the role of transient receptor potential cation channel subfamily M member 2 (TRPM2) in hepatic ischemia-reperfusion injury of mouse (HIRI) and the possible mechanisms.@*METHODS@#Sixty adult male C57BL/6 mice were randomly divided into 4 groups: a sham group (S group), a HIRI model group (M group), a TRPM2 adenovirus interference vector group (T group), and a TRPM2 adenovirus control vector group (C group) (=15 in each group). The liver tissues of mice before perfusion were obtained. The efficiency of adenovirus infection was detected by fluorescence microscopy, and the silencing efficiency of adenovirus against TRPM2 was detected by real-time PCR.The abdominal aorta blood and liver tissues were collected from mice at 2, 4 and 8 h after reperfusion. The activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in serum of mice were detected. Hepatic pathological changes were examined by hematoxylin-eosin (HE) staining. The protein expression of TRPM2 and Rac family small GTPase 1 (RAC1) in liver tissues was detected by Western blotting. Changes of malondialdehyde (MDA), superoxide dismutase (SOD) and myeloperoxidase (MPO) activities in liver tissues were detected by enzyme-linked immunosorbent assay.@*RESULTS@#A strong signal of green fluorescence was observed in the liver tissues of mice in the T and C groups compared to the S or M group. Compared with the S, M or C group, the expression of TRPM2 mRNA in liver tissue in the T group was significantly down-regulated (all <0.05). The morphology of hepatocytes was normal in the S group under light microscope.Hepatic sinus dilatation, congestion, hepatocyte degeneration, central necrosis of lobule, and massive inflammatory granulocyte infiltration were observed in the M and C group, respectively. The degree of hepatocyte damage in the T group was significantly reduced compared with that in the M and C group, respectively. Compared with the S group, the serum ALT and AST activities in the M, T and C groups were significantly increased at 2, 4 and 8 h after reperfusion (all <0.05). Compared with the M or C group, the serum ALT and AST activities in the T group were significantly lower in serum of mice at 2, 4, and 8 h after reperfusion (all <0.05). Compared with the M or C group, the serum SOD activity in the T group was significantly increased at 2, 4, and 8 h after reperfusion (all <0.05), while the serum MDA and MPO activities were significantly decreased (all <0.05). The protein expression of TRPM2 and RAC1 in liver tissues in the T group were significantly lower than those in the M and C groups at 2, 4 and 8 h after reperfusion (all <0.05).@*CONCLUSIONS@#Pretreatment with TRPM2 adenovirus interference vector can effectively silence TRPM2 gene expression in liver tissues of mice and attenuate HIRI, which may be related to inhibiting oxidative stress and reducing the expression of RAC1 protein.

Extraction and purification of NUDT9 homology domain of human transient receptor potential melastatin 2 channel / 浙江大学学报·医学版

OBJECTIVE@#To develop methods of extraction and purification of Cterminal NUDT9 homology domain of human transient receptor potential melastatin 2 (TRPM2) channel.@*METHODS@#After sonication and centrifuge of strain Rosetta (DE3) which was induced by isopropylthio-β-D-galactoside, GST-NUDT9-H was collected after the binding of supernatant with GST beads and eluted with reduced glutathione. Then the elution buffer containing fusion protein was purified by size exclusion chromatography after concentration and centrifuge. Finally, with the cleavage of thrombin and binding with the GST beads, NUDT9-H with high purity in supernatant was collected.@*RESULTS@#The GST-NUDT9-H fusion protein was stabilized with lysis buffer containing 0.5% n-dodecyl -β-d-maltoside (DDM), and wash buffer containing 0.025% DDM in size-exclusion chromatography system, and finally the NUDT9-H with high purity was obtained after cleaved by thrombin (1 U/2 mg fusion protein) for 24 h.@*CONCLUSIONS@#Due to the poor stability of NUDT9-H, it is necessary to add DDM in extraction and purification buffer to stabilize the conformation of NUDT9-H, so as to increase its yields and purity.

Structural modeling of selectivity filter in transient receptor pontential melastatin 8 ion channel / 浙江大学学报·医学版

OBJECTIVE@#To construct a three-dimensional structural model for the selectivity filter in the transient receptor pontential melastatin 8 (TRPM8) ion channel.@*METHODS@#In the Rosetta computational structural biology suite, multiple rounds of modeling with the kinematic loop closure algorithm were performed.@*RESULTS@#After nine rounds of computational modeling, we obtained the models of the selectivity filter within the TRPM8 channel with the lowest energy and high convergence. The model showed that the sidechain of D918 points were away from the central ion permeation pathway, while the sidechains of Q914, D920 and T923 pointed towards it. The glycosylation site N934 was located outside the pore region and its side chain directed to the extracellular water environment.@*CONCLUSIONS@#A three-dimensional structural model for the selectivity filter in the TRPM8 ion channel was constructed, which provides reliable structural information for exploring the mechanism of ion selectivity.

Analysis of TRPM6 gene variant in a pedigree affected with hypocalcemia secondary to hypomagnesemia / 中华医学遗传学杂志

OBJECTIVE@#To explore the molecular pathogenesis for a pedigree affected with hypocalcemia secondary to hypomagnesemia.@*METHODS@#Sanger sequencing was used to detect potential variant of the TRPM6 gene in the patient and their parents.@*RESULTS@#The results showed that the patient has carried novel homozygous c.3311C>T (p.Pro1104Leu) variant of the TRMP6 gene, for which both of his parents were heterozygous carriers. Analysis of protein functions using software predicted high risk of pathogenicity.@*CONCLUSION@#The homozygous c.3311C>T (p.Pro1104Leu) variant of the TRPM6 gene probably underlies the disease in this patient.

Clinical features and TRPM6 mutations of an infant with hypomagnesemia with secondary hypocalcemia / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical features and mutations of the TRPM6 gene in an infant featuring hypomagnesemia and secondary hypocalcemia.@*METHODS@#Clinical data of the patient was collected. Genomic DNA was extracted from peripheral blood samples from the patient and her parents. Targeted exome sequencing was carried out to screen the potential mutations. Suspected mutations were verified by Sanger sequencing.@*RESULTS@#A novel homozygous c.5538delA (p.Q1846Qfs*2) mutation in the TRPM6 gene was identified in the proband, for which both of her parents were heterozygous carriers.@*CONCLUSION@#The homozygous frameshift mutation of TRPM6 gene (c.5538delA) probably underlies the disease in the proband. The finding has expanded the mutation spectrum of TRPM6 gene.

Association of single nucleotide polymorphism in exon of transient receptor potential melastatin 2 gene with sepsis / 浙江大学学报·医学版

To investigate the association between single nucleotide polymorphism (SNP) in the 11th exon of transient receptor potential melastatin 2 (TRPM2) gene with the susceptibility and outcome of sepsis.A total of 119 septic patients and 112 normal subjects were enrolled from the First Affiliated Hospital, Zhejiang University School of Medicine. Among 119 septic patients, 62 died (fatal group) and 57 survived (survival group) within 28 days of disease onset. The genotypes of these individuals were detected using TaqMan allelic discrimination assays, and its correlations with susceptibility and outcome of sepsis were analyzed.There was no significant difference in genotype frequencies and allelic frequencies of TRPM2 SNP rs1556314 between septic patients and the controls (all>0.05). And no significant difference in genotype frequencies and allelic frequencies of TRPM2 SNP rs1556314 was observed between the survivors and fatal cases of septic patients (all>0.05).The TRPM2 SNP rs1556314 does not have significant association with sepsis, but this result need to be confirmed by large scale studies.

Transient Receptor Potential Melastatin 2:an Ion Channel for Oxidative Stress Sensing / 中国医学科学院学报

Transient receptor potential (TRP) channel is a superfamily of cation channels located on the cell membrane. TRP channels are classified into seven subfamilies based on the amino acid sequence homology,and transient receptor potential melastatin 2(TRPM2) is the second member of the TRPM subfamily. More evidences have revealed the important roles of TRPM2 in physiological and pathological events such as release of insulin from pancreatic Β-cells,inflammatory cytokines production from cells,and oxidative stress-induced cell death. As a cellular sensor for oxidative stress channel,TRPM2 is activated by a variety of factors. TRPM2 is a potential therapeutic target for oxidative stress-related diseases.

TRPM7 and tumor / 中南大学学报(医学版)

The transient receptor potential (TRP) family is a superfamily of cation channels located on the cell membrane. Transient receptor potential melastatin (TRPM) 7, a member of the TRPM subgroup of TRP channels, and was the most representative biofunctional membrane protein. It conducts calcium and monovalent cations to depolarize cells and increase intracellular calcium. It is capable of phosphorylating TRPM7 and other substrates. TRPM7 can mediate sensory transmission, regulate cellular Ca2+ and Mg2+ homeostasis and affect embryonic development. Abnormal expression and/or activity of the TRPM7 channel kinase is involved in a variety of diseases, particularly the development and progression of cancer. TRPM7 channel-kinase is essential for cellular processes, such as proliferation, survival, differentiation, growth, and migration.

Novel identification and characterisation of Transient receptor potential melastatin 3 ion channels on Natural Killer cells and B lymphocytes: effects on cell signalling in Chronic fatigue syndrome/Myalgic encephalomyelitis patients

BACKGROUND: Transient receptor potential melastatin 3 (TRPM3) cation channels are ubiquitously expressed by multiple cells and have an important regulatory role in calcium-dependent cell signalling to help maintain cellular homeostasis. TRPM3 protein expression has yet to be determined on Natural Killer (NK) cells and B lymphocytes. Multiple single nucleotide polymorphisms have been reported in TRPM3 genes from isolated peripheral blood mononuclear cells, NK and B cells in Chronic fatigue syndrome/Myalgic encephalomyelitis (CFS/ME) patients and have been proposed to correlate with illness presentation. The object of the study was to assess TRPM3 surface expression on NK and B lymphocytes from healthy controls, followed by a comparative investigation examining TRPM3 surface expression, and cytoplasmic and mitochondrial calcium influx in CD19+ B cells, CD56bnght and CD56dim cell populations from CFS/ME patients. RESULTS: TRPM3 cell surface expression was identified for NK and B lymphocytes in healthy controls (CD56bright TRPM3 35.72 % ± 7.37; CD56dim 5.74 % ± 2.00; B lymphocytes 2.05 % ± 0.19, respectively). There was a significant reduction of TRPM3 surface expression on CD19+ B cells (1.56 ± 0.191) and CD56bright NK cells (17.37 % ± 5.34) in CFS/ME compared with healthy controls. Anti-CD21 and anti-IgM conjugated biotin was cross-linked with streptavidin,and subsequently treatment with thapsigargin. This showed a significant reduction in cytoplasmic calcium ion concentration in CD19+ B lymphocytes. CD56bright NK cells also had a significant decrease in cytoplasmic calcium in the presence of 2-APB and thapsigargin in CFS/ME patients. CONCLUSIONS: The results from this preliminary investigation identify, for the first time, TRPM3 surface expression on both NK and B lymphocytes in healthy controls. We also report for the first time, significant reduction in TRPM3 cell surface expression in NK and B lymphocytes, as well as decreased intracellular calcium within specific conditions in CFS/ME patients. This warrants further examination of these pathways to elucidate whether TRPM3 and impaired calcium mobilisation has a role in CFS/ME.

Role of transient receptor potential melastatin 8 channels in migraine mechanism in rats / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the role of transient receptor potential melastatin 8 (TRPM8) channels in migraine mechanism in rats by measuring the changes in expression of TRPM8 in the trigeminal nerve of rats with migraine.</p><p><b>METHODS</b>Twenty male Sprague-Dawley rats were randomly and equally divided into a blank control group and a model group. Nitroglycerin (10 mg/kg) was injected subcutaneously in the back of the neck once a week for 5 weeks, to prepared a rat model of migraine without aura. Normal saline was injected subcutaneously instead of nitroglycerin in the control group. At 4 hours after the final injection, behavior scoring of all rats was performed, and then the trigeminal nerve ganglions of rats in both groups were collected for measurement of expression of N-methyl-D-aspartate receptor (NMDAR), protein kinase A (PKA), and TRPM8 using immunohistochemical staining, immunofluorescence, and Western blot, respectively.</p><p><b>RESULTS</b>The behavior score in each week during the rat model preparing was significantly higher in the model group than in the control group (P<0.05). The expression of NMDAR, PKA, and TRPM8 in the model group was significantly higher than in the control group (P<0.01). Both the behavior score and the expression of NMDAR were positively correlated with the expression of TRPM8 (r=0.822 and 0.794 respectively; P<0.01).</p><p><b>CONCLUSIONS</b>TRPM8 may be involved in migraine mechanism probably by activation of the NMDAR pathway.</p>

Early diagnosis of prostate cancer by combined use of Trp-p8 expression and PSA density of the transition zone / 中华男科学杂志

<p><b>OBJECTIVE</b>To study the expression of the Trp-p8 protein in the prostate tissue of the PSA "grey zone" with different PSA density of the transition zone (PSADTZ) and explore the value of determining Trp-p8 expression and PSADTZ in the early diagnosis of prostate cancer (PCa).</p><p><b>METHODS</b>This study involved 30 cases of benign prostatic hyperplasia (BPH) and another 30 cases of PCa with different PSADTZ values. Using a data imaging and analysis system, we determined the expression levels of Trp-p8 in BPH and PCa tissues and analyzed their correlation with PSADTZ.</p><p><b>RESULTS</b>The expression of Trp-p8 was weak or negative in the BPH but strong in the PCa tissue and even stronger in the PCa tissue with high PSADTZ (F = 34. 05, P < 0.05).</p><p><b>CONCLUSION</b>The Trp-p8 protein is expressed differently in BPH and PCa tissues of the PSA " grey zone" and its expression is positively correlated with PSADTZ. Determination of the Trp-p8 expression and PSADTZ contributes to the early diagnosis of prostate cancer.</p>

Effect of traditional Chinese medicines with different properties on thermoregulation and temperature-sensitive transient receptor potentialion channel protein of rats with yeast-induced fever / 中国中药杂志

<p><b>OBJECTIVE</b>To compare the intervention effects of four traditional Chinese medicines (TCMs) with typical cold or hot property on body temperature and temperature-sensitive transient receptor potential ion channel proteins (TRPs) of rats with yeast-induced fever.</p><p><b>METHOD</b>The pyrexia model was induced by injecting yeast suspension subcutaneously. Totally 108 male SD rats were randomly divided into the normal group, the model group, the Rhei Radix et Rhizoma treated group, the Coptidis Rhizoma treated group, the Euodiae Fructus treated group, and the Alpiniae Officinarum Rhizoma treated group, with 18 rats in each group. At the 4 h, 8 h and 12 h after injection of yeast, the rats were sacrificed to collect their hypothalamus and dorsal root ganglion. The expressions of TRPV1 and TRPM8 were detected by immunohistochemistry and Western blot method.</p><p><b>RESULT</b>Compared with the normal group, after injection of yeast, the temperature of rats in the model group notably increased, and reached the peak at 8 h (P < 0.01). The TRPV1 level in hypothalamus and dorsal root ganglia (DRG) of the model group significantly increased, whereas the TRPM8 level significantly reduced. Compared with the model group, the Rhei Radix et Rhizoma group and the Coptidis Rhizoma group showed significant decrease in the high body temperature of rats caused by yeast, down-regulation in the expression of TRPV1, and up-regulation in the expression of TRPM8 (P < 0.05 or P < 0.01). Euodiae Fructus and Alpiniae Officinarum Rhizoma had no significant effect on either temperature or TRPs of fever rats.</p><p><b>CONCLUSION</b>Rhei Radix et Rhizoma and Coptidis Rhizoma, both are TCMs with cold property, can reduce the temperature of fever rats induced by yeast, which may be related to their effective regulation of TRPV1 and TRPM8 in hypothalamus and DRG, while Euodiae Fructus and Alpiniae Officinarum Rhizoma had no relevant effect.</p>

TRPM2: a multifunctional ion channel for oxidative stress sensing / 生理学报

Transient receptor potential (TRP) superfamily is a superfamily of cation channels that can be divided into seven subfamilies. TRPM2 is the second member of the TRPM subfamily, which includes eight members, namely TRPM1-8. TRPM2 is widely expressed in excitable and non-excitable cells, where it forms a Ca(2+)-permeable cation channel and performs diverse cellular functions. TRPM2 channels are activated by ADP-ribose (ADPR), Ca(2+), H2O2 and other reactive oxygen species (ROS). It is established that TRPM2 serves as a cellular sensor for oxidative stress, mediating oxidative stress-induced [Ca(2+)]i increase and contributing to pathological processes in many cell types. Accumulating evidence has indicated that TRPM2 is a potential therapeutic target for oxidative stress-related diseases. This review will highlight recent progress in this field.

Decreased amplitude of Ca²⁺i elevation induced by menthol in pulmonary arterial smooth muscle cells of pulmonary hypertensive rats / 生理学报

The study was designed to explore the alteration of intracellular calcium concentration ([Ca²⁺]i), induced by transient receptor potential melastatin 8 (TRPM8) channel-specific agonist menthol, in pulmonary arterial smooth muscle cells (PASMCs) between control and pulmonary hypertensive (PH) rats. PH rat models were established by means of chronic hypoxia (CH) and monocrotaline (MCT) injection, respectively. PASMCs from control and PH rats were cultured. The change of [Ca²⁺]i in PASMCs induced by menthol, and the effect of TRPM8 channel-specific antagonist BCTC on the change of [Ca²⁺]i, were observed. Cellular localization of TRPM8 was examined by using immunohistochemistry. Results showed that menthol increased [Ca²⁺]i in the control PASMCs both in Ca²⁺ -normal and Ca²⁺ - free Tyrode's solutions, and at the same time BCTC could inhibit these two kinds of elevations. Compared with the control group, elevations of [Ca²⁺]i were decreased notably in CH- and MCT-pretreated PASMCs superfused with 2 mmol/L Ca²⁺ - or 0 Ca²⁺ -Tyrode's solutions. Immunohistochemical localization experiments showed that the whole PASMCs were dyed brown except for the nucleus. This study verified that TRPM8 exists both in membrane and sarcoplasmic reticulum of PASMCs. In addition, CH- and MCT-pretreatment could independently down-regulate the Ca²⁺ influx and Ca²⁺ release mediated by TRPM8 channel.