TRPM7 Expression Research Articles

The Effect of Osthole on Transient Receptor Potential Channels: A Possible Alternative Therapy for Atopic Dermatitis.

Chronic recurrent skin inflammation and severe itching in patients with atopic dermatitis (AD) significantly impair their quality of life. The H4 histamine receptor plays a key role in histamine-induced itching. During the skin inflammation associated with AD, pro-inflammatory mediators (interleukins, cytokines) are released from neurons. Ultimately, a cascade of reactions leads to the activation and sensitization of transient receptor potential channels (TRP), which exacerbate the inflammation and itching associated with AD. Osthole (OST) is a natural coumarin with a proven versatile pharmacological effect: anti-cancer, anti-inflammatory and immunomodulatory. However, the molecular mechanism of OST in relieving inflammation in histamine-mediated itching is not yet clear. In the studies presented, the possible effect of the OST action on the inhibition of the gene expression of the histamine H4 receptor and the key genes of the TRP channels as well as on the concentration of proinflammatory interleukins was analyzed. Inflammation was induced in a 3D skin model and a keratinocyte cell line Normal Human Epidermal Keratinocytes (NHEK) identical to that of AD, and then OST was administered at various doses. The concentrations of IL-4/-13 were determined by ELISA. RNA was isolated from the 3D skin cells and the NHEK cell line, and the qPCR method was used to determine the expression of: IL-4α, H4R, TRPV1, TRPV4, TRPM8 analyzed. The study showed that OST significantly reduced the secretion of IL-4/-13 in a keratinocyte cell line and in a 3D skin model. In addition, OST was found to significantly decrease the gene expression of IL-4α, H4R, TRPV1, TRPV4 and increase TRPM8 in both the NHEK cell line and the organotypic 3D skin model. The data obtained provide the first in vitro evidence of itch relief following the application of OST to atopic skin. Research on the use of OST as an active component of emollients in the treatment of AD should be continued in the future.

Cold temperature induces a TRPM8-independent calcium release from the endoplasmic reticulum in human platelets.

The detection of temperature by the human sensory system is life-preserving and highly evolutionarily conserved. Platelets are sensitive to temperature changes and are activated by a decrease in temperature, akin to sensory neurons. However, the molecular mechanism of this temperature-sensing ability is unknown. Yet, platelet activation by temperature could contribute to numerous clinical sequelae, most importantly to reduced quality of ex vivo-stored platelets for transfusion. In this multidisciplinary study, we present evidence for the expression of the temperature-sensitive ion channel transient receptor potential cation channel subfamily member 8 (TRPM8) in human platelets and precursor cells. We found the TRPM8 mRNA and protein in MEG-01 cells and platelets. Inhibition of TRPM8 prevented temperature-induced platelet activation and shape change. However, chemical agonists of TRPM8 did not seem to have an acute effect on platelets. When exposing platelets to below-normal body temperature, we detected a cytosolic calcium increase which was independent of TRPM8 but was completely dependent on the calcium release from the endoplasmic reticulum. Because of the high interindividual variability of TRPM8 expression, a population-based approach should be the focus of future studies. Our study suggests that the cold response of platelets is complex and TRPM8 appears to play a role in early temperature-induced activation of platelets, while other mechanisms likely contribute to later stages of temperature-mediated platelet response.

Carotid body denervation improves hyperglycemia in obese mice.

The carotid bodies (CBs) have been implicated in glucose abnormalities in obesity via elevation of activity of the sympathetic nervous system. Obesity-induced hypertension is mediated by insulin receptor (INSR) signaling and by leptin, which binds to the leptin receptor (LEPRb) in CB and activates transient receptor potential channel subfamily M member 7 (TRPM7). We hypothesize that in mice with diet-induced obesity, hyperglycemia, glucose intolerance, and insulin resistance will be attenuated by the CB denervation (carotid sinus nerve dissection, CSND) and by knockdown of Leprb, Trpm7, and Insr gene expression in CB. In series of experiments in 75 male diet-induced obese (DIO) mice, we performed either CSND (vs. sham) surgeries or shRNA-induced suppression of Leprb, Trpm7, or Insr gene expression in CB, followed by blood pressure telemetry, intraperitoneal glucose tolerance and insulin tolerance tests, and measurements of fasting plasma insulin, leptin, corticosterone, glucagon and free fatty acids (FFAs) levels, hepatic expression of gluconeogenesis enzymes phosphoenolpyruvate carboxykinase (PEPCK) and glucose 6-phosphatase (G-6-Pase) mRNA and liver glycogen levels. CSND decreased blood pressure, fasting blood glucose levels and improved glucose tolerance without any effect on insulin resistance. CSND did not affect any hormone levels and gluconeogenesis enzymes, but increased liver glycogen level. Genetic knockdown of CB Leprb, Trpm7, and Insr had no effect on glucose metabolism. We conclude that CB contributes to hyperglycemia of obesity, probably by modulation of the glycogen-glucose equilibrium. Diabetogenic effects of obesity on CB in mice do not occur via activation of CB Leprb, Trpm7, and Insr.NEW & NOTEWORTHY This paper provides first evidence that carotid body denervation abolishes hypertension and improves fasting blood glucose levels and glucose tolerance in mice with diet-induced obesity. Furthermore, we have shown that this phenomenon is associated with increased liver glycogen content, whereas insulin sensitivity and enzymes of gluconeogenesis were not affected.

TRPM8 Contributes to Early Temperature-Induced Platelet Activation

Background: Like sensory neurons, platelets are activated by a decrease in temperature. However, the molecular mechanism of this temperature-sensing ability is unknown. Platelet activation by temperature could contribute to numerous clinical observations, most importantly to the well-known reduced lifespan of ex vivo-stored platelets for transfusion. In this study, we sought to dissect the molecular basis of the cold-induced platelet activation response and specifically, evaluate the role of the thermosensitive ion channel transient receptor potential cation channel subfamily member 8 (TRPM8) in platelets and their precursor cells. Methods: We tested for the presence of TRPM8 on the megakaryocytic cell line MEG-01 and human platelets by immunoblotting, confocal microscopy, and imaging flow cytometry. The effect of TRPM8 on platelets was evaluated using the commercially available TRPM8 inhibitor PF-05105679. In addition, we used TRPM8 agonists such as menthol, WS-12, and icilin. Platelet shape change and αIIbβ3 integrin activation were assessed by imaging flow cytometry and conventional flow cytometry. We tested for platelet aggregation using light transmission aggregometry and for intracellular calcium by reading fluorescence on a plate reader after loading platelets with Fura-2-AM. Calcium release in response to temperature decrease was assessed after loading platelets or TRPM8-transfected HEK293T/17 and reading fluorescence in a Real-Time PCR Detection System. Results: We detected TRPM8 mRNA and protein in MEG-01 cells and platelets but there was a remarkable variability among donors. Further evidence for TRPM8's presence in platelets came from the fact that inhibitors of TRPM8 prevented early temperature-induced platelet activation events, such as αIIbβ3 integrin activation and shape change. Unlike temperature changes, chemical agonists of TRPM8 did not seem to have an acute effect on platelets. Platelets exposed to below-normal body temperature displayed a cytosolic calcium increase, but this was independent of TRPM8 and entirely dependent on the calcium release from the endoplasmic reticulum. Conclusion: We found evidence for TRPM8 expression in platelets but the expression varies greatly between individuals and is of unclear physiologic significance. Our study suggests that the cold response of platelets is complex, and TRPM8 appears to play a calcium-independent role in the early temperature-induced activation of platelets, while other mechanisms likely contribute to later stages of temperature-mediated platelet response. Because of the high interindividual variability of TRPM8 expression, a population-based approach should be the focus of future studies.

Expression of transient receptor potential channels on peripheral blood leukocytes of patients with chronic obstructive pulmonary disease

It is known that transient receptor potential (TRP) channels are receptors for reactive oxygen species and components of cigarette smoke, and therefore may be involved in the pathogenesis of chronic obstructive pulmonary disease (COPD).Aim: To investigate the expression of TRPV1, TRPV4, TRPM8 and TRPA1 channels on peripheral blood leukocytes of COPD patients and healthy individuals and to establish its possible relationships with inflammatory markers and lung function parameters.Methodology and Research Methods. 23 patients with COPD of varying severity and 17 individuals without bronchial obstruction were examined. The expression of TRP channels on monocytes, lymphocytes and granulocytes was determined by indirect flow cytometry. Plasma concentrations of cytokines were measured in a multiplex assay. Lung function parameters were assessed by spirometry.Results. Monocytes from COPD patients were characterized by increased expression of TRPV1 (98.8 (97.6; 99.6)% vs. 97.8 (96.3; 98.6)%, p = 0.03) and TRPA1 (99.2 (98.7; 99.8)% vs. 95.1 (94.2; 98.4)%, p = 0.003). In addition, COPD was associated with an increased ratio of TRPV4/TRPM8 expression on monocytes (0.66 (0.51, 0.90) vs. 0.27 (0.12, 0.70), p = 0.02) and granulocytes (0.97 (0.86; 0.92) vs. 0.29 (0.06; 0.89), p = 0.003). TRPV4 expression on monocytes showed correlation with CXCL10 level (ρ = 0.55, p = 0.01), and for TRPM8 inverse relationships were found with the concentrations of IL-6 (ρ = –0.56, p = 0.02) and IL-10 (ρ = –0.55, p = 0.02). We did not find any associations between the expression of TRP channels and lung function parameters.Conclusion. Increased expression of TRPV1 and TRPA1, as well as an increased TRPV4/TRPM8 ratio on peripheral blood monocytes of COPD patients may indicate the contribution of these receptors to the proinflammatory activation of the cells and indicate possible prospects of TRP channels pharmacological modulation for the purpose of the disease therapy.

Ischemia-Reperfusion Increases TRPM7 Expression in Mouse Retinas.

Ischemia is the main cause of cell death in retinal diseases such as vascular occlusions, diabetic retinopathy, glaucoma, or retinopathy of prematurity. Although excitotoxicity is considered the primary mechanism of cell death during an ischemic event, antagonists of glutamatergic receptors have been unsuccessful in clinical trials with patients suffering ischemia or stroke. Our main purpose was to analyze if the transient receptor potential channel 7 (TRPM7) could contribute to retinal dysfunction in retinal pathologies associated with ischemia. By using an experimental model of acute retinal ischemia, we analyzed the changes in retinal function by electroretinography and the changes in retinal morphology by optical coherence tomography (OCT) and OCT-angiography (OCTA). Immunohistochemistry was performed to assess the pattern of TRPM7 and its expression level in the retina. Our results show that ischemia elicited a decrease in retinal responsiveness to light stimuli along with reactive gliosis and a significant increase in the expression of TRPM7 in Müller cells. TRPM7 could emerge as a new drug target to be explored in retinal pathologies associated with ischemia.

Electrophysiological evidence that TRPM3 is a candidate in latent spinal sensitization of chronic low back pain

Latent spinal sensitization is one key mechanism developing at the early stage of chronic low back pain (LBP). TRPM3-mediated calcium transients of dorsal root ganglia (DRG) neurons are considered critical presynaptic signals involved in this latent sensitization. However, postsynaptic consequences in input laminae of the spinal cord have not been addressed so far. Here, by electrophysiological recordings in acute spinal cord slices from adult rats, we show that perfusion of the TRPM3 agonist pregnenolone sulfate (PregS) induced a significant increase in the frequency but not amplitude of spontaneous postsynaptic currents in lamina I and II neurons. This frequency increase started slowly during PregS perfusion but was reversible following washout. This result is consistent with a presynaptic action of the neurosteroid PregS, indicating the presynaptic expression of functional TRPM3 in the superficial dorsal horn of adult rats. Thus, PregS-induced TRPM3 activation enhances spinal synaptic strength, implying a mediating role of TRPM3 between neuroendocrine and nociceptive signaling, which might as well exist in chronic LBP primed by chronic stress that promotes the biosynthesis of PregS.

Improvement of actin dynamics and cognitive impairment in diabetes through troxerutin-mediated downregulation of TRPM7/CaN/cofilin

Diabetic cognitive impairment is a central nervous complication of diabetes mellitus. Its specific pathogenesis is unknown, and no effective treatment strategy is currently available. An imbalance in actin dynamics is an important mechanism underlying cognitive impairment. Transient receptor potential channel 7 (TRPM7) mediates actin dynamics imbalance through calcineurin (CaN) and cofilin cascades involved in various neurodegenerative diseases. We previously demonstrated that TRPM7 expression is increased in diabetic cognitive impairment, and troxerutin has been shown to ameliorate diabetic cognitive impairment. However, the relationship between troxerutin and TRPM7 remains unclear. In this study, we hypothesize that troxerutin may improve diabetic cognitive impairment by enhancing actin dynamics through downregulation of the TRPM7/CaN/cofilin pathway. To test this hypothesis, we divided db/m and db/db mice into the following groups: normal control group (NC), normal + troxerutin group (NT), diabetic group (DM), diabetic + troxerutin group (DT) and diabetic + troxerutin + bradykinin group (DTB). The results showed that diabetic mice exhibited cognitive impairment at 17 weeks of age, TRPM7, CaN, cofilin and G-actin were highly expressed in the CA1 region of hippocampus, while p-cofilin and F-actin expression decreased. Furthermore, hippocampal neuronal cellsshowed varying degrees of damage. The length of synaptic active zone, the width of synaptic cleft, and the number of synapses per high-power field were decreased. Troxerutin intervention alleviated these manifestations in the DT group; however, the effect of troxerutin was weakened in the DTB group. In conclusion, our findings suggest that diabetes leads to cognitive impairment, activation of the TRPM7/CaN/cofilin pathway, actin dynamics imbalance, and destruction of hippocampal neuronal cells and synapses. Troxerutin can downregulate TRPM7/CaN/cofilin, improve actin dynamics imbalance, and ameliorate cognitive impairment in diabetic mice. This study provides a new avenue for exploring and treating cognitive impairment in diabetes.

Association of higher transient receptor potential melastatin 8 expression with higher tumor histologic grades, lymph node metastasis, risk factors, and worse survival in patients with head and neck squamous cell carcinoma

Background/purposeTransient receptor potential melastatin 8 (TRPM8), a thermosensitive ion channel known for its role in cold sensation and menthol response, has emerged as a potential regulator in various cancers. This study aimed to investigate expression trends of TRPM8 in head and neck squamous cell carcinoma (HNSCC) cases and oral squamous cell carcinoma (OSCC) cell lines and its association with clinicopathological features. Materials and methodsThe noncancerous matched tissues and HNSCC paired tissue samples from 84 HNSCC patients were utilized to evaluate the association of TRPM8 with HNSCC clinicopathological features. TRPM8 expression was examined in HNSCC patient tissues and OSCC cell lines treated with arecoline. ResultsKaplan-Meier survival analysis of TCGA data revealed high TRPM8 expression correlated with unfavorable outcomes and higher tumor histologic grades. TRPM8 mRNA expression was upregulated in HNSCC cell lines and patients’ tissue samples. Arecoline treatment led to significantly increased TRPM8 mRNA and protein expression in OSCC cell lines. Lymph node metastasis showed a significant association with upregulated TRPM8 expression in combined OSCC and oropharyngeal squamous cell carcinoma (OPSCC) cases. TRPM8 mRNA expression was upregulated in HNSCC and OSCC patients with alcohol drinking and cigarette smoking habits, but not in betel quid chewing. ConclusionThese findings reveal the involvement of TRPM8 in HNSCC's malignant development and metastasis, suggesting that high expression of TRMP8 may be mutually causal with addiction to tobacco, alcohol, and betel nut in HNSCC patients. Further investigations are needed to determine the underlying pathways of TRPM8 in HNSCC's development and progression.

Abstract P229: Beyond Cooling Sensation: Topical Penile Administration Of The Trpm8 Agonist Improves Hypertension Associated-erectile Dysfunction

Background and Purpose: Erectile dysfunction (ED) is an indicator for futurecardiovascular events. The search for new targets is crucial due to the low efficacy ofPDE5 inhibitors in patients with endothelial dysfunction. Menthol, a TRPM8 agonist, iswidely used in preparations to improve sensation during sexual intercourse, although nodata are reported for the improvement of ED. So, we hypothesize that chronic topicalactivation of TRPM8 improves hypertension associated-ED. Experimental Approach: Adult (9-12 weeks) male spontaneously hypertensive rats (SHR) and Wistar rats wereused for protein expression analysis and TRPM8 agonist curves in isolated CC. We alsotreated rats topically on the penis for 30 days with carbopol 940 (hydrogel, vehicle) ormenthol (carbopol 940 + menthol 0.1%). After treatment, we measured the mean bloodpressure (MBP), CC and iliac (IL) artery contractility. Key Results: Both strains of rathad similar TRPM8 expression in CC by western blotting and immunofluorescence.TRPM8 activation by cooling compounds, icilin (10 -8 –10 -4 M) or menthol (10 -7 –10 -3 M),relaxed CC strips pre-contracted by phenylephrine (PE, 10 -6 or 10 -5 M), but with reducedeffect in SHR. Interestingly, the topical penile treatment with menthol decreased the MBPof the SHR (151.8±6.8 mmHg, n=6) compared to the SHR vehicle group (174.6±2.6mmHg, n=5; p<0.05). In addition, in CC, the concentration-response curves to PE andthromboxane agonists were shifted to the left after menthol treatment. Interestingly, nochange in acetylcholine and sodium nitroprusside (SNP) relaxation were observed aftertopical penile treatment with menthol. The concentration-response curves to PE and SNPwere shifted to the left in IL arterial rings. This suggests topical menthol administrationinduced systemic vascular influence leading to a response like the normotensive Wistar. Conclusion: TRPM8 channels are expressed and functional in the CC, with decreasedsensitivity in SHR. Also, our data suggest that topical administration of menthol improvesthe reactivity of vascular tissue, demonstrating the potential of TRPM8 activation fortherapeutic benefits in hypertension associated-ED.

TRPM7 transactivates the FOSL1 gene through STAT3 and enhances glioma stemness

IntroductionWe previously reported that TRPM7 regulates glioma cells’ stemness through STAT3. In addition, we demonstrated that FOSL1 is a response gene for TRPM7, and the FOSL1 gene serves as an oncogene to promote glioma proliferation and invasion.MethodsIn the present study, we determined the effects of FOSL1 on glioma stem cell (GSC) markers CD133 and ALDH1 by flow cytometry, and the maintenance of stem cell activity by extreme limiting dilution assays (ELDA). To further gain insight into the mechanism by which TRPM7 activates transcription of the FOSL1 gene to contribute to glioma stemness, we constructed a FOSL1 promoter and its GAS mutants followed by luciferase reporter assays and ChIP-qPCR in a glioma cell line and glioma patient-derived xenoline. We further examined GSC markers ALDH1 and TRPM7 as well as FOSL1 by immunohistochemistry staining (IHC) in brain tissue microarray (TMA) of glioma patients.ResultsWe revealed that FOSL1 knockdown reduces the expression of GSC markers CD133 and ALDH1, and FOSL1 is required to maintain stem cell activity in glioma cells. The experiments also showed that mutations of − 328 to − 336 and − 378 to − 386 GAS elements markedly reduced FOSL1 promoter activity. Constitutively active STAT3 increased while dominant-negative STAT3 decreased FOSL1 promoter activity. Furthermore, overexpression of TRPM7 enhanced while silencing of TRPM7 reduced FOSL1 promoter activity. ChIP-qPCR assays revealed that STAT3, present in nuclear lysates of glioma cells stimulated by constitutively activated STAT3, can bind to two GAS elements, respectively. We demonstrated that deacetylation of FOSL1 at the Lys-116 residue located within its DNA binding domain led to an increase in FOSL1 transcriptional activity. We found that the expression of TRPM7, ALDH1, and FOSL1 protein is associated with grades of malignant glioma, and TRPM7 protein expression correlates to the expression of ALDH1 and FOSL1 in glioma patients.ConclusionsThese combined results demonstrated that TRPM7 induced FOSL1 transcriptional activation, which is mediated by the action of STAT3, a mechanism shown to be important in glioma stemness. These results indicated that FOSL1, similar to GSC markers ALDH1 and TRPM7, is a diagnostic marker and potential drug target for glioma patients.

TCAF2 in Pericytes Promotes Colorectal Cancer Liver Metastasis via Inhibiting Cold-Sensing TRPM8 Channel.

Hematogenous metastasis is the main approach for colorectal cancer liver metastasis (CRCLM). However, as the gatekeepers in the tumor vessels, the role of TPCs in hematogenous metastasis remains largely unknown, which may be attributed to the lack of specific biomarkers for TPC isolation. Here, microdissection combined with a pericyte medium-based approach is developed to obtain TPCs from CRC patients. Proteomic analysis reveals that TRP channel-associated factor 2(TCAF2), a partner protein of the transient receptor potential cation channel subfamily M member 8 (TRPM8), is overexpressed in TPCs from patients with CRCLM. TCAF2 in TPCs is correlated with liver metastasis, short overall survival, and disease-free survival in CRC patients. Gain- and loss-of-function experiments validate that TCAF2 in TPCs promotes tumor cell motility, epithelial-mesenchymal transition (EMT), and CRCLM, which is attenuated in pericyte-conditional Tcaf2-knockout mice. Mechanistically, TCAF2 inhibits the expression and activity of TRPM8, leading to Wnt5a secretion in TPCs, which facilitates EMT via the activation of the STAT3 signaling pathway in tumor cells. Menthol, a TRPM8 agonist, significantly suppresses Wnt5a secretion in TPCs and CRCLM. This study reveals the previously unidentified pro-metastatic effects of TPCs from the perspective of cold-sensory receptors, providing a promising diagnostic biomarker and therapeutic target for CRCLM.

Identification of TRPM2 as a prognostic factor correlated with immune infiltration in ovarian cancer

IntroductionOvarian cancer (OC) is one of the most common gynecologic malignant cancers with the current survival rate remaining low. TRPM2 has been reported as a survival predictor in various cancers but not in OC. The aim of this study is to explore the role and its underlying mechanism of TRPM2 in OC.MethodsThe transcriptome data and clinical data were obtained from TCGA, GTEx, and GEO (GSE17260). DriverDBv3 and PrognoScan were used to analyze survival correlations. GSEA analysis was performed to uncover the underlying mechanism. The correlations between TRPM2 and immune score, immune cell infiltration were analyzed by TIMER2.0.ResultsTRPM2 was highly expressed in OC and high TRPM2 expression was related to the poor prognosis based on the Kaplan-Meier curves, univariate and multivariate analysis. The enrichment analysis suggested that TRPM2 was involved in immune-related pathways. Positive correlations were also observed between TRPM2 expression and immune score and immune cells covering B cells, T cells, macrophage, neutrophil, and myeloid dendritic cells. We also found that TRPM2 was positively related to immune checkpoints including ICOSLG, CD40, CD86, etc. TRPM2 expression had a positive correlation with M2 macrophage, but not with M1 macrophage. Besides, TRPM2 showed a strong positive correlation with pyroptosis-related genes including NLRP3, NLRC4, NOD2, NOD1, IL1B, GSDMD.ConclusionOur study demonstrated that TRPM2 is a poor prognostic prediction factor in ovarian cancer and is correlated to the immune microenvironment and pyroptosis. TRPM2 may act as a new immunotherapy target, which promoted the survival rate of OC patients.

Macrophage RIPK3 triggers inflammation and cell death via the XBP1–Foxo1 axis in liver ischaemia–reperfusion injury

Receptor-interacting serine/threonine-protein kinase 3 (RIPK3) is a central player in triggering necroptotic cell death. However, whether macrophage RIPK3 may regulate NOD1-dependent inflammation and calcineurin/transient receptor potential cation channel subfamily M member 7 (TRPM7)-induced hepatocyte death in oxidative stress-induced liver inflammatory injury remains elusive. A mouse model of hepatic ischaemia-reperfusion (IR) injury, the primary hepatocytes, and bone marrow-derived macrophages were used in the myeloid-specific RIPK3 knockout (RIPK3M-KO) and RIPK3-proficient (RIPK3FL/FL) mice. RIPK3M-KO diminished IR stress-induced liver damage with reduced serum alanine aminotransferase/aspartate aminotransferase levels, macrophage/neutrophil infiltration, and pro-inflammatory mediators compared with the RIPK3FL/FL controls. IR stress activated RIPK3, inositol-requiring transmembrane kinase/endoribonuclease 1α (IRE1α), x-box binding protein 1 (XBP1), nucleotide-binding oligomerisation domain-containing protein 1 (NOD1), NF-κB, forkhead box O1 (Foxo1), calcineurin A, and TRPM7 in ischaemic livers. Conversely, RIPK3M-KO depressed IRE1α, XBP1, NOD1, calcineurin A, and TRPM7 activation with reduced serum tumour necrosis factor α (TNF-α) levels. Moreover, Foxo1M-KO alleviated IR-induced liver injury with reduced NOD1 and TRPM7 expression. Interestingly, chromatin immunoprecipitation coupled with massively parallel sequencing revealed that macrophage Foxo1 colocalised with XBP1 and activated its target gene Zc3h15 (zinc finger CCCH domain-containing protein 15). Activating macrophage XBP1 enhanced Zc3h15, NOD1, and NF-κB activity. However, disruption of macrophage Zc3h15 inhibited NOD1 and hepatocyte calcineurin/TRPM7 activation, with reduced reactive oxygen species production and lactate dehydrogenase release after macrophage/hepatocyte coculture. Furthermore, adoptive transfer of Zc3h15-expressing macrophages in RIPK3M-KO mice augmented IR-triggered liver inflammation and cell death. Macrophage RIPK3 activates the IRE1α-XBP1 pathway and Foxo1 signalling in IR-stress livers. The XBP1-Foxo1 interaction is essential for modulating target gene Zc3h15 function, which is crucial for the control of NOD1 and calcineurin-mediated TRPM7 activation. XBP1 functions as a transcriptional coactivator of Foxo1 in regulating NOD1-driven liver inflammation and calcineurin/TRPM7-induced cell death. Our findings underscore a novel role of macrophage RIPK3 in stress-induced liver inflammation and cell death, implying the potential therapeutic targets in liver inflammatory diseases. Macrophage RIPK3 promotes NOD1-dependent inflammation and calcineurin/TRPM7-induced cell death cascade by triggering the XBP1-Foxo1 axis and its target gene Zc3h15, which is crucial for activating NOD1 and calcineurin/TRPM7 function, implying the potential therapeutic targets in stress-induced liver inflammatory injury.

Transient receptor potential M2 channel in the hypothalamic preoptic area and its impact on thermoregulation during menopause

BackgroundDecreased estrogen levels can cause abnormal thermosensitivity of the preoptic area (POA) in the hypothalamus during menopause, which may cause hot flashes. Thermosensitive transient receptors (ThermoTRPs) affect the thermosensitivity of neurons. It is worth exploring whether ThermoTRPs change under low estrogen state and participate in the abnormal thermoregulation of POA. MethodsAdult female Sprague–Dawley rats were randomly divided into sham operation (SHAM), ovariectomy (OVX) and estrogen treatment after ovariectomy (OVX+E) groups. Under 10 ℃, 18 ℃, 25 ℃, 37 ℃ and 45 ℃ incubations, their skin temperature was monitored and the expression of TRPA1, TRPM8, TRPM2, and TRPV1 in POA were investigated. ResultsThe skin temperature of ovariectomized rats changed faster and more dramatically under different incubation temperatures. The results at mRNA level show that only the expression of TRPM2 decreased in POA of OVX group compared with the other two groups at 25 ℃, TRPA1 expression in POA of the three groups increased at 10 ℃, TRPM8 increased at 10 ℃ and 18 ℃, TRPV1 increased at 10 ℃ and 45 ℃, while the expression of TRPM2 decreased at 10 ℃ and 18 ℃ and increased at 37 ℃ and 45 ℃. In all these cases, the magnitudes of the changes were less in the OVX group relative to the other two groups. The further immunohistochemical and Western blot results of TRPM2 and the activated TRPM2 positive cells labeled by c-Fos were consistent with the results of mRNA level. ConclusionsThe expression and thermosensitivity of TRPM2 in POA changed greatly under different incubation temperatures, but the changes in ovariectomized rats were less. This may be the key factor triggering thermoregulation dysfunction under low estrogen and may cause hot flashes.

Long Noncoding RNA ST7-AS1 Upregulates TRPM7 Expression by Sponging microRNA-543 to Promote Cervical Cancer Progression [Retraction

[This retracts the article DOI: 10.2147/OTT.S253868.].

TRPM2 Channels: A Potential Therapeutic Target in Melanoma?

The transient receptor potential, the melastatin (TRPM) subfamily, which consists of eight known members, appears to have significant importance in melanoma progression, treatment, and prognosis. As several members were originally cloned from cancerous tissue, initial studies aimed towards identifying TRPM involvement in cancer progression and tumorigenesis. For relevance in skin cancer, previous research has shown roles for several TRPM members in skin cancer progression, growth, and patient prognosis. One unique member, TRPM2, appears to have notable therapeutic potential in the treatment of melanoma. Previous and recent studies have demonstrated increased TRPM2 expression levels in melanoma, as well as important roles for TRPM2 in melanoma growth, proliferation, and survival. TRPM2 is thus an emerging target in the treatment of melanoma, where TRPM2 antagonism may offer an additional treatment option for melanoma patients in the future.

Functional expression of the thermally activated transient receptor potential channels TRPA1 and TRPM8 in human myotubes

Transient potential (TRP) ion channels expressed in primary sensory neurons act as the initial detectors of environmental cold and heat, information which controls muscle energy expenditure. We hypothesize that non-neuronal TRPs have direct cellular responses to thermal exposure, also affecting cellular metabolism. In the present study we show expression of TRPA1, TRPM8 and TRPV1 in rat skeletal muscle and human primary myotubes by qPCR. Effects of TRP activity on metabolism in human myotubes were studied using radiolabeled glucose. FURA-2 was used for Ca2+ imaging.TRPA1, TRPM8 and TRPV1 were expressed at low levels in primary human myotubes and in m. gastrocnemius, m. soleus, and m. trapezius from rat. Activation of TRPA1 by ligustilide resulted in an increased glucose uptake and oxidation in human myotubes, whereas activation of TRPM8 by menthol and icilin significantly decreased glucose uptake and oxidation. Activation of heat sensing TRPV1 by capsaicin had no effect on glucose metabolism. Agonist-induced increases in intracellular Ca2+ levels by ligustilide and icilin in human myotubes confirmed a direct activation of TRPA1 and TRPM8, respectively. The mRNA expression of some genes involved in thermogenesis, i.e. peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), uncoupling protein (UCP) 1 and UCP3, were downregulated in human myotubes following TRPA1 activation, while the mRNA expression of TRPM8 and TRPA1 were downregulated following TRPM8 activation by menthol and icilin, respectively. Cold exposure (18 °C) of cultured myotubes followed by a short recovery period had no effect on glucose uptake and oxidation in the basal situation, however when TRPA1 and TRPM8 channels were chemically inhibited a temperature-induced difference in glucose metabolism was found.In conclusion, mRNA of TRPA1, TRPM8 and TRPV1 are expressed in rat skeletal muscle and human skeletal muscle cells. Modulation of TRPA1 and TRPM8 by chemical agents induced changes in Ca2+ levels and glucose metabolism in human skeletal muscle cells, indicating functional receptors.

Human Osteoarthritic Chondrocytes Express Nineteen Different TRP-Genes-TRPA1 and TRPM8 as Potential Drug Targets.

Transient receptor potential (TRP) ion channels are expressed in neuronal and some non-neuronal cells and are involved particularly in pain and thermosensation. We previously showed that TRPA1 is functionally expressed in human osteoarthritic (OA) chondrocytes and mediates inflammation, cartilage degradation, and pain in monosodium-iodoacetate-induced experimental OA. In the present study, we explored the expression of TRP-channels in primary human OA chondrocytes and investigated whether drugs used in the treatment of OA, ibuprofen and glucocorticoids, have effects on TRP-channel expression. OA cartilage was obtained from knee replacement surgery and chondrocytes were isolated with enzyme digestion. NGS analysis showed the expression of 19 TRP-genes in OA chondrocytes, with TRPM7, TRPV4, TRPC1, and TRPM8 having the highest counts in unstimulated cells. These results were verified with RT-PCR in samples from a different group of patients. Interleukin-1β (IL-1β) significantly increased TRPA1 expression, while TRPM8 and TRPC1 expression was decreased, and TRPM7 and TRPV4 expression remained unaffected. Furthermore, dexamethasone attenuated the effect of IL-1β on TRPA1 and TRPM8 expression. The TRPM8 and TRPA1 agonist menthol increased the expression of the cartilage-degrading enzymes MMP-1, MMP-3, and MMP-13 and the inflammatory factors iNOS and IL-6 in OA chondrocytes. In conclusion, human OA chondrocytes express 19 different TRP-genes, of which the significant TRPM8 expression is a novel finding. Dexamethasone attenuated IL-1β-induced TRPA1 expression. Interestingly, the TRPM8 and TRPA1 agonist menthol increased MMP expression. These results support the concept of TRPA1 and TRMP8 as potential novel drug targets in arthritis.

"ThermoTRP" Channel Expression in Cancers: Implications for Diagnosis and Prognosis (Practical Approach by a Pathologist).

Temperature-sensitive transient receptor potential (TRP) channels (so-called "thermoTRPs") are multifunctional signaling molecules with important roles in cell growth and differentiation. Several "thermoTRP" channels show altered expression in cancers, though it is unclear if this is a cause or consequence of the disease. Regardless of the underlying pathology, this altered expression may potentially be used for cancer diagnosis and prognostication. "ThermoTRP" expression may distinguish between benign and malignant lesions. For example, TRPV1 is expressed in benign gastric mucosa, but is absent in gastric adenocarcinoma. TRPV1 is also expressed both in normal urothelia and non-invasive papillary urothelial carcinoma, but no TRPV1 expression has been seen in invasive urothelial carcinoma. "ThermoTRP" expression can also be used to predict clinical outcomes. For instance, in prostate cancer, TRPM8 expression predicts aggressive behavior with early metastatic disease. Furthermore, TRPV1 expression can dissect a subset of pulmonary adenocarcinoma patients with bad prognosis and resistance to a number of commonly used chemotherapeutic agents. This review will explore the current state of this rapidly evolving field with special emphasis on immunostains that can already be added to the armoire of diagnostic pathologists.