This paper aims to investigate the influence of eucalyptol on the biological effects of spleen cold and spleen heat syndromes in rats and its regulation of transient receptor potential vanilloid 1(TRPV1), transient receptor potential melastatin 8(TRPM8), and uncoupling protein 1(UCP1), so as to explore the cold-heat properties of eucalyptol. Rats were randomly divided into groups as follows: blank group, spleen cold syndrome model group, spleen cold syndrome+Atractylodis Rhizoma group, spleen cold syndrome + low-dose eucalyptol group, and spleen cold syndrome+high-dose eucalyptol group, as well as blank group, spleen heat syndrome model group, spleen heat syndrome+Coptidis Rhizoma group, spleen heat syndrome + low-dose eucalyptol group, and spleen heat syndrome + high-dose eucalyptol group. Spleen cold and spleen heat syndromes were induced by disorders of hunger and satiety combined with bitter cold drugs, as well as a high-fat diet combined with liquor. Except for the blank and model groups, the other groups were administered once a day during the modeling process for 14 consecutive days. The general condition and body weight of rats in each group were observed, and the histopathological morphology of the gastric antrum and small intestine was observed by hematoxylin-eosin(HE) staining. The contents of cyclic adenosine monophosphate(cAMP), cyclic guanosine monophosphate(cGMP), triiodothyronine(T3), thyroxine(T4), Na~+-K~+-ATPase, total cholesterol(TC), triglyceride(TG), gastrin(GAS), motilin(MTL), D-xylose, and other related indices were detected in rats. The expression levels of TRPV1, TRPM8, and UCP1 in small intestine tissue of rats with spleen cold syndrome were detected. The results showed that eucalyptol had a certain degree of improvement in the overall state and body weight of rats with spleen cold syndrome. Compared with the spleen cold syndrome model group, high-dose eucalyptol significantly increased the levels of serum cAMP, cAMP/cGMP, TG, and TC in rats with spleen cold syndrome(P<0.05, P<0.01), decreased the content of cGMP, and significantly elevated the levels of gastrointestinal function-related indicators GAS, MTL, and D-xylose(P<0.05, P<0.01). Low-dose eucalyptol significantly increased the level of cAMP/cGMP in the serum and Na~+-K~+-ATPase levels in hepatic tissue(P<0.05, P<0.01), and significantly increased the levels of GAS and D-xylose(P<0.01). Eucalyptol showed similar effects to Atractylodis Rhizoma with a warm nature on rats with spleen cold syndrome. Compared with the spleen heat syndrome model group, the high-dose and low-dose eucalyptol groups showed a trend of increase in gastrointestinal indicators, with no significant changes in other indicators. In addition, high-dose eucalyptol increased the expression of TRPV1 and UCP1 and decreased the expression of TRPM8 in the small intestine tissue of rats with spleen cold syndrome. Eucalyptol could affect the cyclic nucleotide and material energy metabolism levels of rats with spleen cold syndrome and had a certain improvement effect on their gastrointestinal digestion and absorption function, thereby improving spleen cold syndrome. Eucalyptol had no significant improvement effect on rats with spleen heat syndrome, suggesting that eucalyptol may have a warm nature and regulate spleen meridians. It is speculated that eucalyptol may exhibit its medicinal properties by activating the TRPV1 pathway, promoting the expression of UCP1, and inhibiting the TRPM8 channel.
Animals ; Rats ; Spleen/metabolism* ; Male ; TRPV Cation Channels/genetics* ; Rats, Sprague-Dawley ; Eucalyptol/administration & dosage* ; TRPM Cation Channels/genetics* ; Uncoupling Protein 1/genetics* ; Humans ; Drugs, Chinese Herbal/administration & dosage* ; Cold Temperature ; Cyclic GMP/metabolism*

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.
Rats ; Animals ; AMP-Activated Protein Kinases/metabolism* ; Nerve Growth Factor/metabolism* ; Diabetes Mellitus, Experimental/drug therapy* ; TRPM Cation Channels/metabolism* ; GAP-43 Protein/metabolism* ; Signal Transduction ; Diabetic Neuropathies/genetics* ; Fibrosis

Mice ; Animals ; Actins/metabolism* ; Actin Depolymerizing Factors/metabolism* ; TRPM Cation Channels ; Actin Cytoskeleton/metabolism* ; Nervous System/metabolism*

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.
Apoptosis ; Benzeneacetamides ; Cell Survival ; Glucose ; Humans ; Oxygen/metabolism* ; Piperidones ; Reactive Oxygen Species/metabolism* ; Reperfusion ; TRPM Cation Channels

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.
Amyloid beta-Peptides/metabolism* ; Humans ; Neurodegenerative Diseases ; Neuroglia ; TRPM Cation Channels/genetics* ; Transient Receptor Potential Channels

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.
Escherichia coli ; genetics ; Glucosides ; chemistry ; Humans ; Protein Domains ; Protein Stability ; Pyrophosphatases ; chemistry ; genetics ; isolation & purification ; Recombinant Fusion Proteins ; chemistry ; isolation & purification ; TRPM Cation Channels ; chemistry ; isolation & purification ; Thrombin ; metabolism

As a crucial signaling molecule, calcium plays a critical role in many physiological and pathological processes by regulating ion channel activity. Recently, one study resolved the structure of the transient receptor potential melastatin 2 (TRPM2) channel from Nematostella vectensis (nvTRPM2). This identified a calcium-binding site in the S2-S3 loop, while its effect on channel gating remains unclear. Here, we investigated the role of this calcium-binding site in both nvTRPM2 and human TRPM2 (hTRPM2) by mutagenesis and patch-clamp recording. Unlike hTRPM2, nvTRPM2 cannot be activated by calcium alone. Moreover, the inactivation rate of nvTRPM2 was decreased as intracellular calcium concentration was increased. In addition, our results showed that the four key residues in the calcium-binding site of S2-S3 loop have similar effects on the gating processes of nvTRPM2 and hTRPM2. Among them, the mutations at negatively charged residues (glutamate and aspartate) substantially decreased the currents of nvTRPM2 and hTRPM2. This suggests that these sites are essential for calcium-dependent channel gating. For the charge-neutralizing residues (glutamine and asparagine) in the calcium-binding site, our data showed that glutamine mutating to alanine or glutamate did not affect the channel activity, but glutamine mutating to lysine caused loss of function. Asparagine mutating to aspartate still remained functional, while asparagine mutating to alanine or lysine led to little channel activity. These results suggest that the side chain of glutamine has a less contribution to channel gating than does asparagine. However, our data indicated that both glutamine mutating to alanine or glutamate and asparagine mutating to aspartate accelerated the channel inactivation rate, suggesting that the calcium-binding site in the S2-S3 loop is important for calcium-dependent channel inactivation. Taken together, our results uncovered the effect of four key residues in the S2-S3 loop of TRPM2 on the TRPM2 gating process.
Animals ; Asparagine/physiology* ; Binding Sites ; Calcium/metabolism* ; Glutamine/physiology* ; HEK293 Cells ; Humans ; Ion Channel Gating/physiology* ; Sea Anemones ; TRPM Cation Channels/physiology*

OBJECTIVETo 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).

METHODSThis 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.

RESULTSThe 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).

CONCLUSIONThe 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.

Biomarkers, Tumor ; metabolism ; Early Detection of Cancer ; methods ; Humans ; Male ; Prostate ; metabolism ; Prostate-Specific Antigen ; metabolism ; Prostatic Hyperplasia ; diagnosis ; metabolism ; Prostatic Neoplasms ; diagnosis ; metabolism ; TRPM Cation Channels ; metabolism

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.
Animals ; Calcium ; metabolism ; Cells, Cultured ; Menthol ; pharmacology ; Myocytes, Smooth Muscle ; drug effects ; metabolism ; Pulmonary Artery ; cytology ; Rats ; Sarcoplasmic Reticulum ; metabolism ; TRPM Cation Channels ; metabolism

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.
Adenosine Diphosphate Ribose ; metabolism ; Calcium ; physiology ; Calcium Channels ; physiology ; Humans ; Hydrogen Peroxide ; metabolism ; Oxidative Stress ; Reactive Oxygen Species ; metabolism ; TRPM Cation Channels ; physiology