Polypeptide nanoparticles conjugated with an NIR-II organic dye for TRPV1 channel blockade enhance mild phototheranostics.

Photothermal therapy (PTT) has attracted attention as a highly effective non-invasive treatment method. However, the high localized temperatures (>50 °C) required for its treatment will inevitably cause damage to the surrounding normal tissues. Therefore, it is important to develop novel and effective strategies to achieve mild photothermal therapy (mPTT). The overexpression of heat shock proteins (HSPs), a widespread heat stress protein, leads to the generation of heat resistance in cancer cells, which seriously affects the therapeutic effect. Thus, inhibiting the expression of HSPs to reduce the heat resistance of tumor cells is expected to enhance the therapeutic effect of mPTT. Here, we successfully synthesized a fluorescent probe bonded with an amphiphilic polypeptide to a cyanine dye and achieved physical encapsulation of the blocker SB705498 through a self-assembly process. SB705498 promotes transient receptor potential vanilloid member 1 (TRPV1) channel blockade that can inhibit the translocation of the heat shock transcription factor 1 (HSF 1) by blocking the influx of calcium and thus affecting the expression of HSPs, which has the potential to enhance the thermotherapy of cancer under mild conditions. In addition, the nanoparticles enabled NIR-II fluorescence imaging with good stability and high photothermal conversion efficiency (48.10 %). Therefore, this study provides a new strategy for realizing precise mPTT(<45 °C) guided by NIR-II imaging. STATEMENT OF SIGNIFICANCE: Inhibition of overexpression of heat shock proteins (HSPs) in cancer photothermal therapy (PTT) is expected to enhance the therapeutic effect of mild photothermal therapy (mPTT). In this study, we synthesized a fluorescent probe bonded to cyanine dyes with amphiphilic polypeptides and physically wrapped the blocker SB705498 through a self-assembly process. As a transient receptor potential vanillin 1 (TRPV1) channel blocker, SB705498 inhibits heat shock transcription factor 1 (HSF1) translocation by blocking calcium ion influx, thereby improving mPTT efficacy by inhibiting the expression of HSPs. The nanoparticles also enable NIR-II fluorescence imaging with good stability and high photothermal conversion efficiency (48.10 %). Thus, this study provides a new strategy for NIR-II mPTT.

TRPM4 mRNA stabilization by METTL3-mediated m6A modification promotes calcific aortic valve inflammation.

Background: Transient receptor potential melastatin 4 (TRPM4) affects immune responses by regulating calcium homeostasis, but its role in calcific aortic valve inflammation remains unclear. This study aimed to assess the expression and function of TRPM4 in patients with or without calcific aortic valve disease (CAVD). Methods: The mRNA and protein expression levels of TRPM4 and related factors in calcified and noncalcified tissues were measured using qRT-PCR and Western blot. The proteins interacting with TRPM4 were confirmed by RNA pull-down and RNA immunoprecipitation assays. Dual-Luciferase Reporter Assay was performed to confirm the m6A site of TRPM4. Results: The mRNA expression levels of TRPM4, TLR4, IL-6, MCP-1, TNF-α, and NF-κB p65 were significantly higher in calcified aortic valve tissues than in noncalcified tissues, and TRPM4 was significantly positively correlated with inflammation-related factors. The protein expression level of TRPM4, TLR4 and NF-κB p65 were significantly higher in calcified aortic valve tissues than in noncalcified tissues. N6-methyladenosine (m6A) modification of TRPM4 mRNA by METTL3-YTHDF1 up-regulated its expression in CAVD. And TRPM4 promoted the level of inflammation via activation of the JNK-MAPK signaling pathway, after knockdown TRPM4, the production of proinflammatory cytokines was significantly suppressed. Conclusion: The results indicate the pivotal role of TRPM4 in CAVD and highlight METTL3-mediated m6A modification of TRPM4 in promoting inflammation through JNK-MAPK signaling pathway. This work provides potential therapeutic strategy to impede inflammation in CAVD.

Involvement of the TRPV1 receptor and the endocannabinoid system in schizophrenia.

BACKGROUND: Schizophrenia (SCZ) is a severe mental disorder, but its pathogenesis is still unknown, and its clinical treatment effect is very limited. Transient receptor potential vanilloid 1 (TRPV1) channel and the Endocannabinoid System (ECS)have been confirmed to be involved in the pathogenesis of SCZ, although their actions have not been fully clarified yet. The objective is to examine TRPV1 and ECS expression in the blood of schizophrenia patients and investigate their correlation with disease severity. METHODS: This is a cross-sectional investigation. Peripheral blood samples were gathered from normal controls (NC, n=37), as well as individuals with schizophrenia, including first episode (n=30) and recurrent (n=30) cases. We employed western blot and ELISA techniques to quantify TRPV1, cannabinoid receptors 1(CB1), anandamide (AEA), and 2-arachidonoylglycerol (2-AG), and assess the severity of the patient's symptoms by means of the PANSS scale. RESULTS: Compared to NC, TRPV1 levels showed a noticeable decrease in both first episode schizophrenia (f-SCZ group) and recurrent schizophrenia (r-SCZ group) subjects. Additionally, CB1 levels appeared increased in f-SCZ group. Furthermore, 2-AG levels were found to be elevated in both f-SCZ group and r-SCZ group compared to NC, whereas AEA levels were decreased in f-SCZ group but increased in r-SCZ group. Moreover, among schizophrenia patients, TRPV1 demonstrated a negative correlation with negative symptoms. Within r-SCZ subjects, CB1 displayed a negative correlation with relapse number, while 2-AG showed a correlation in the opposite direction. CONCLUSIONS: This study provides initial clinical evidence of changed TRPV1 expression in schizophrenia, potentially linked to negative symptoms. These results suggest a possible dysfunction of TRPV1 and the endocannabinoid system (ECS), which might offer new avenues for medical interventions.

Discovery of pyridazinone derivatives bearing tetrahydroimidazo[1,2-a]pyrazine scaffold as potent inhibitors of transient receptor potential canonical 5 to ameliorate hypertension-induced renal injury in rats.

Transient receptor potential canonical 5 (TRPC5) is a calcium-permeable non-selective cation channel involved in various pathophysiological processes, including renal injury. Recently, GFB-887, an investigational pyridazinone TRPC5 inhibitor, demonstrated significant therapeutic potential in a Phase II clinical trial for focal segmental glomerulosclerosis (FSGS), a rare and severe form of chronic kidney disease (CKD). In the current study, based on the structure of GFB-887, we conducted extensive structural modification to explore novel TRPC5 inhibitors with desirable drug-like properties and robust nephroprotective efficacy. A series of pyridazinone derivatives featuring a novel tetrahydroimidazo[1,2-a]pyrazine scaffold were synthesized and their activities were evaluated in HEK-293 cells stably expressing TRPC5 using a fluorescence-based Ca2+ mobilization assay. Among these compounds, compound 12 is turned out to be a potent TRPC5 inhibitor with apparent affinity comparable to the parent compound GBF-887. Compound 12 is highly selective on TRPC4/5 over TRPC3/6/7 and hERG channels, along with acceptable pharmacokinetic properties and a favorable safety profile. More importantly, in a rat model of hypertension-induced renal injury, oral administration of compound 12 (10 mg/kg, BID) efficaciously reduced mean blood pressure, inhibited proteinuria, and protected podocyte damage. These findings further confirmed the potential of TRPC5 inhibitors on the CKD treatment and provided compound 12 to be a valuable tool for exploring TRPC4/5 pathophysiology.

Effect of Oleuropein on Anti-Obesity and Uncoupling Protein 1 Level in Brown Adipose Tissue in Mild Treadmill Walking Rats with Diet-Induced Obesity.

Oleuropein aglycone (OA), which is the absorbed form of oleuropein, is a major phenolic compound in extra virgin olive oil. We analyzed the anti-obesity effect of OA intake combined with mild treadmill walking (MTW, 4 m/min for 20 min/d, 5-6 d/wk, without electric shocks and slope) in rats under a high-fat diet (HF). Four-week-old male Sprague-Dawley rats (n=28) were equally divided into four groups: control (HF), 0.08% oleuropein-supplemented HF (HFO), HF with MTW (HF+W), and HFO with MTW (HFO+W) groups. After 28 d, the inguinal subcutaneous fat content and weight gain were significantly lower in the HFO+W group than in the control group. The HFO+W group also had significantly higher levels of urinary noradrenaline secretion, interscapular brown adipose tissue, uncoupling protein 1, brain transient receptor potential ankyrin subtype 1 (TRPA1), vanilloid subtype 1 (TRPV1), and brain-derived neurotrophic factor (BDNF) than the control group. Especially, the HFO+W group showed a synergistic effect on noradrenaline secretion. Therefore, OA combined with MTW may accelerate the enhancement of UCP1 and BDNF levels in rats with HF-induced obesity by increasing noradrenaline secretion after TRPA1 and TRPV1 activation.

Transient receptor potential mucolipin 1 circumvents oxidative stress in primary human melanocytes.

BACKGROUND: Transient Receptor Potential Mucolipin 1 (TRPML1) serves as a pivotal reactive oxygen species (ROS) sensor in cells, which is implicated in the regulation of autophagy. However, its function in melanocyte autophagy under oxidative stress remains elusive. METHODS: The expression and ion channel function of TRPML1 were investigated using immunofluorescence and calcium imaging in primary human melanocytes (MCs). After activating TRPML1 with MLSA1 (TRPML1 agonist), autophagy-related molecules were investigated via western blot. ROS level, apoptosis- and autophagy-related molecules were investigated after pretreatment with MLSA1. After interference with TRPML1 expression, mitochondrial structures were visualized by electron microscopy with hydrogen peroxide (H2O2）treatment. RESULTS: TRPML1 was expressed and functionally active in primary human MCs, and its activation promotes elevated expression of LC3-II and reduced apoptosis and ROS levels under oxidative stress. TRPML1 downregulation caused mitochondrial swelling and disruption of cristae structures under oxidative stress in primary human MCs. CONCLUSIONS: TRPML1 might mediate lysosomal autophagy in primary human MCs under oxidative stress, participating in mechanisms that maintain the oxidative and antioxidant systems in balance.

Post-traumatic stress disorder: the role of the amygdala and potential therapeutic interventions - a review.

Introduction: Post-traumatic stress disorder (PTSD) is a psychiatric disorder triggered by exposure to a life-threatening or sexually violent traumatic event, and is characterized by symptoms involving intrusive re-experiencing, persistent avoidance of associated stimuli, emotional and cognitive disturbances, and hyperarousal for long periods after the trauma has occurred. These debilitating symptoms induce occupational and social impairments that contribute to a significant clinical burden for PTSD patients, and substantial socioeconomic costs, reaching approximately $20,000 dollars per individual with PTSD each year in the US. Despite increased translational research focus in the field of PTSD, the development of novel, effective pharmacotherapies for its treatment remains an important unmet clinical need. Observations: In this review, we summarize the evidence implicating dysfunctional activity of the amygdala in the pathophysiology of PTSD. We identify the transient receptor potential canonical (TRPC) ion channels as promising drug targets given their distribution in the amygdala, and evidence from animal studies demonstrating their role in fear response modulation. We discuss the evidence-based pharmacotherapy and psychotherapy treatment approaches for PTSD. Discussion: In view of the prevalence and economic burden associated with PTSD, further investigation is warranted into novel treatment approaches based on our knowledge of the involvement of brain circuitry and the role of the amygdala in PTSD, as well as the potential added value of combined pharmacotherapy and psychotherapy to better manage PTSD symptoms.

Far-infrared irradiation increases the uptake of LDL cholesterol by downregulating PCSK9 through the activation of TRPV4 calcium channels in HepG2 cells.

This study investigated the effects of far-infrared (FIR) irradiation on low-density lipoprotein cholesterol (LDL-C) uptake by human hepatocellular carcinoma G2 (HepG2) cells via the regulation of proprotein convertase subtilisin/kexin type 9 (PCSK9). FIR irradiation for 30 min significantly decreased PCSK9 expression (p < 0.01) in HepG2 cells. FIR irradiation substantially increased the low-density lipoprotein receptor (p < 0.0001) and LDL-C uptake (p < 0.01). Activation of transient receptor potential vanilloid (TRPV) channels mimicked the effects of FIR irradiation, significantly decreasing the protein expression of PCSK9 (p < 0.05). Conversely, inhibition of TRP channels using ruthenium red reversed the reduction in PCSK9 protein expression following FIR irradiation (p < 0.01). The specific activation of TRPV4 using 4α-PDD mimicked the effect of FIR irradiation (p < 0.01), whereas PCSK9 reduction by FIR irradiation was significantly reversed by the inhibition of TRPV4 using RN1734 (p < 0.05). These findings implied that FIR irradiation emitted from a ceramic lamp specifically increased TRPV4 activity. These findings provide insights into a novel therapeutic approach using FIR irradiation for LDL-C regulation and its implications for cardiovascular health.

(S)-ML-SA1 ACTIVATES AUTOPHAGY VIA TRPML1-TFEB PATHWAY.

Autophagic flux plays a crucial role in various diseases. Recently, the lysosomal ion channel TRPML1 has emerged as a promising target in lysosomal storage diseases, such as mucolipidosis. The discovery of mucolipin synthetic agonist-1 (ML-SA1) has expanded our understanding of TRPML1's function and its potential therapeutic uses. However, ML-SA1 is a racemate with limited cellular potency and poor water solubility. In this study, we synthetized rac-ML-SA1, separated the enantiomers by chiral liquid chromatography and determined their absolute configuration by vibrational circular dichroism (VCD). In addition, we focused on investigating the impact of each enantiomer of ML-SA1 on the TRPML1-TFEB axis. Our findings revealed that (S)-ML-SA1 acts as an agonist for TRPML1 at the lysosomal membrane. This activation prompts transcription factor EB (TFEB) to translocate from the cytosol to the nucleus in a dose-dependent manner within live cells. Consequently, this signaling pathway enhances the expression of coordinated lysosomal expression and regulation (CLEAR) genes and activates autophagic flux. Our study presents evidence for the potential use of (S)-ML-SA1 in the development of new therapies for lysosomal storage diseases that target TRPML1.

An updated patent review of TRPA1 antagonists (2020 - present).

INTRODUCTION: TRPA1 is a nonselective calcium channel, a member of the transient receptor potential (TRP) superfamily, also referred to as the 'irritant' receptor, being activated by pungent and noxious exogenous chemicals as well as by endogenous algogenic stimuli, to elicit pain, itching, and inflammatory conditions. For this reason, it is considered an attractive therapeutic target to treat a wide range of diseases including acute and chronic pain, itching, and inflammatory airway diseases. AREAS COVERED: The present review covers patents on TRPA1 antagonists disclosed from 2020 to present, falling in the following main classes: i) novel therapeutic applications for known or already disclosed antagonists, ii) identification and characterization of TRPA1 antagonists from natural sources, and iii) synthesis and evaluation of novel compounds. EXPERT OPINION: Despite the limited number of TRPA1 antagonists in clinical trials, there is an ever-growing interest on this receptor-channel as therapeutic target, mainly due to the relevant outcomes from basic research, which unveiled novel physio-pathological mechanisms where TRPA1 is believed to play a pivotal role, for example the Alzheimer's disease or ocular diseases, expanding the panel of potential therapeutic applications for TRPA1 modulators.

Latest Insights into the In Vivo Studies in Murine Regarding the Role of TRP Channels in Wound Healing-A Review.

Wound healing involves physical, chemical and immunological processes. Transient receptor potential (TRP) and other ion channels are implicated in epidermal re-epithelization. Ion movement across ion channels can induce transmembrane potential that leads to transepithelial potential (TEP) changes. TEP is present in epidermis surrounding the lesion decreases and induces an endogenous direct current generating an epithelial electric field (EF) that could be implicated in wound re-epithelialization. TRP channels are involved in the activation of immune cells during mainly the inflammatory phase of wound healing. The aim of the study was to review the mechanisms of ion channel involvement in wound healing in in vivo experiments in murine (mice, rats) and how can this process be influenced. This review used the latest results published in scientific journals over the last year and this year to date (1 January 2023-31 December 3000) in order to include the in-press articles. Some types of TRP channels, such as TRPV1, TRPV3 and TRPA1, are expressed in immune cells and can be activated by inflammatory mediators. The most beneficial effects in wound healing are produced using agonists of TRPV1, TRPV4 and TRPA1 channels or by inhibiting with antagonists, antisense oligonucleotides or knocking down TRPV3 and TRPM8 channels.

Role of transient receptor potential channels in the regulation of vascular tone.

Vascular tone is a major element in the control of hemodynamics. Transient receptor potential (TRP) channels conducting monovalent and/or divalent cations (e.g. Na+ and Ca2+) are expressed in the vasculature. Accumulating evidence suggests that TRP channels participate in regulating vascular tone by regulating intracellular Ca2+ signaling in both vascular smooth muscle cells (VSMCs) and endothelial cells (ECs). Aberrant expression/function of TRP channels in the vasculature is associated with vascular dysfunction in systemic/pulmonary hypertension and metabolic syndromes. This review intends to summarize our current knowledge of TRP-mediated regulation of vascular tone in both physiological and pathophysiological conditions and to discuss potential therapeutic approaches to tackle abnormal vascular tone due to TRP dysfunction.

Genetic and immune identification and functional analysis of TRPM8 as a potential biomarker for pancreatic adenocarcinoma proliferation.

BACKGROUND: Pancreatic adenocarcinoma (PAAD), a member of highly lethal malignant tumors, has a poor outcome and extremely poor prognosis. The transient receptor potential (TRP) superfamily, a group of nonselective cation channels, is capable of influencing cellular functions by regulating calcium homeostasis. In addition, it has been shown that TRP channels can also affect various cellular phenotypes by regulating gene transcription levels and are involved in the development of a variety of malignant tumors. AIMS: In order to find new therapeutic targets and biomarkers to improve the clinical prognosis of pancreatic cancer, we performed genetic and immunological characterization of TRP channels in PAAD, as well as related functional and prognostic analyses. METHODS AND RESULTS: We investigated the expression, genetic alterations, methylation levels, and immune infiltration levels of TRP channels in PAAD, and further also analyzed the function of TRP channels in PAAD and their prognostic value for PAAD patients. Our results suggest that TRPM8 may contribute to tumor proliferation by controlling the PI3K-AKT-mTOR signaling pathway in PAAD. CONCLUSION: After careful evaluation of the accumulated data, we concluded that TRPM8 has potential as a prognostic indicator and prospective therapeutic target in PAAD.

Roles of Thermosensitive Transient Receptor Channels TRPV1 and TRPM8 in Paclitaxel-Induced Peripheral Neuropathic Pain.

Paclitaxel, a microtubule-stabilizing chemotherapy drug, can cause severe paclitaxel-induced peripheral neuropathic pain (PIPNP). The roles of transient receptor potential (TRP) ion channel vanilloid 1 (TRPV1, a nociceptor and heat sensor) and melastatin 8 (TRPM8, a cold sensor) in PIPNP remain controversial. In this study, Western blotting, immunofluorescence staining, and calcium imaging revealed that the expression and functional activity of TRPV1 were upregulated in rat dorsal root ganglion (DRG) neurons in PIPNP. Behavioral assessments using the von Frey and brush tests demonstrated that mechanical hyperalgesia in PIPNP was significantly inhibited by intraperitoneal or intrathecal administration of the TRPV1 antagonist capsazepine, indicating that TRPV1 played a key role in PIPNP. Conversely, the expression of TRPM8 protein decreased and its channel activity was reduced in DRG neurons. Furthermore, activation of TRPM8 via topical application of menthol or intrathecal injection of WS-12 attenuated the mechanical pain. Mechanistically, the TRPV1 activity triggered by capsaicin (a TRPV1 agonist) was reduced after menthol application in cultured DRG neurons, especially in the paclitaxel-treated group. These findings showed that upregulation of TRPV1 and inhibition of TRPM8 are involved in the generation of PIPNP, and they suggested that inhibition of TRPV1 function in DRG neurons via activation of TRPM8 might underlie the analgesic effects of menthol.

Effect of moxibustion at "Xinshu" (BL15) and "Feishu" (BL13) on expression of TRPV1 and CGRP in the myocardial tissue of chronic heart failure rats. / 艾灸"心俞""肺俞"å¯¹æ ¢æ€§å¿ƒåŠ›è¡°ç«­å¤§é¼ å¿ƒè‚Œçž¬æ—¶å—ä½“ç”µä½é¦™è‰é ¸äºšåž‹1ã€é™é’™ç´ åŸºå› ç›¸å ³è‚½è¡¨è¾¾çš„å½±å“.

OBJECTIVES: To observe the effect of moxibustion at "Xinshu" (BL15) and "Feishu" (BL13) on transient receptor potential vanilloid type 1(TRPV1), calcitonin gene-related peptide (CGRP), and serum interleukin-10 (IL-10) in the myocardial tissue of rats with chronic heart failure (CHF), so as to explore its underlying mechanisms in improvement of CHF. METHODS: Male SD rats were randomly divided into the normal, model, moxibustion, capsaicin, moxibustion + capsaicin, and moxibustion + solvent groups, with 10 rats in each group. The CHF model was established by permanent ligation of the anterior descending branch of the left coronary artery. Mild moxibustion was applied to bilateral BL13 and BL15 for 30 min once daily for 4 weeks. Rats in the capsaicin group were smeared with capsaicin in the acupoint area once a day for 4 weeks. For rats of the moxibustion + capsaicin and moxibustion + solvent groups, capsaicin and solvent were applied to the acupoint area before moxibustion for 4 weeks, respectively. The ejection fraction (EF) and left ventricular fractional shortening rate (FS) were examined by echocardiography. HE staining was used to observe the myecardial morphological structure. The mRNA and protein expression levels of TRPV1, CGRP and galectin-3 (Gal-3) in myocardial tissue were detected by real-time quantitative PCR and Western blot, respectively. The content of IL-10 in serum was detected by ELISA. RESULTS: After modeling, the pathological changes of myocardium (as cardiac muscle fiber disorder, inflammatory cell infiltration, etc.) were obvious, and the EF, FS, serum IL-10, protein and mRNA exspression of TRPV1 and CGRP were significantly decreased (P<0.01) in the model group compared with the normal group, while the protein and mRNA exspression of Gal-3 were significantly up-regulated (P<0.01). Following the interventions, the above-mentioned indexes were all reversed in moxibustion, capsaicin, and moxibustion + capsaicin groups (P<0.01), and the effect of moxibustion + capsaicin was the best (P<0.05, P<0.01). CONCLUSIONS: Moxibustion can reduce myocardial injury and improve cardiac function in CHF rats, which may be related to its effects in up-regulating the expression of TRPV1 and CGRP, and down-regulating the expression of Gal-3 to alleviate myocardial fibrosis.

Effect of electroacupuncture on myocardial transient receptor potential channels in mice with myocardial hypertrophy. / ç”µé’ˆå¯¹å¿ƒè‚Œè‚¥åŽšå°é¼ å¿ƒè‚Œç»„ç»‡çž¬æ—¶å—ä½“ç”µä½é€šé“çš„å½±å“.

OBJECTIVES: To observe the effect of electroacupuncture (EA) at "Neiguan"(PC6) on cardiac function, cardiac morphology and transient receptor potential channel (TRPC) protein expressions in myocardial tissue of mice with myocardial hypertrophy, so as to explore its mechanisms underlying improvement of myocardial hypertrophy. METHODS: Forty-five male C57BL/6 mice were randomly divided into control, model and EA groups (15 mice/group). The myocardial hypertrophy model was established by subcutaneous injection of isoproterenol hydrochloride (15 mg·kg-1·d-1) for 14 days. The mice of the control group received subcutaneous injection of same amount of normal saline. The mice of the EA group received EA stimulation (frequency of 2 Hz, intensity of 1 mA) of bilateral PC6 for 20 min each time, once a day for 14 consecutive days. After the intervention, the body weight, tibia length and heart weight were measured. The left ventricular ejection fraction (EF), fractional shortening index (FS), left ventricular end-systolic volume (LVEV), left ventricular end-systolic internal diameter (LVID) and left ventricular posterior wall thickness (LVPW) were measured by using echocardiography for evaluating the cardiac function. The mean number and surface area of myocardial cells was detected by wheat germ agglutinin (WGA) staining, and changes of the cardiac morphology were observed under light microscopy after HE staining. The expression levels of TRPC1, TRPC3, TRPC4 and TRPC6 (TRPC1/3/4/6) in the myocardial tissue were detected by real-time quantitative PCR (qPCR) and Western blot, separately. RESULTS: Compared with the control group, the heart-body weight ratio(P<0.05) and heart-weight-to-tibia-length ratio (P<0.01), LVEV and LVID levels, the relative surface area, left ventricular area ratio, and the expression levels of cardiac TRPC1/3/4/6 were significantly increased (P<0.01, P<0.05), while the EF, FS, LVPW, number of cardiomyocytes, and the left ventricular posterior wall ratio were obviously decreased (P<0.01, P<0.05) in the model group. In comparison with the model group, the heart/body weight ratio, heart-weight-to-tibia-length ratio, LVEV and LVID levels, relative surface area, left ventricular area ratio, and the expression levels of cardiac TRPC1/3/4/6 were significantly decreased (P<0.01, P<0.05), while the EF, FS, LVPW, number of cardiomyocytes and left ventricular posterior wall ratio were significantly increased (P<0.01, P<0.05) in the EA group. H.E. staining showed disordered arrangement of cardiomyocytes and obvious myocardial interstitial inflammatory cell infiltration in the model group, and evident reduction of degree of cardiac fibrosis and interstitial edema in the EA group. CONCLUSIONS: EA of PC6 can improve the cardiac function and cardiac morphology in mice with myocardial hypertrophy, which may be related to its functions in down-regulating the expression of transient receptor potential channels.

Overexpression of TRPV1 activates autophagy in human lens epithelial cells under hyperosmotic stress through Ca2+-dependent AMPK/mTOR pathway.

AIM: To explore whether autophagy functions as a cellular adaptation mechanism in lens epithelial cells (LECs) under hyperosmotic stress. METHODS: LECs were treated with hyperosmotic stress at the concentration of 270, 300, 400, 500, or 600 mOsm for 6, 12, 18, 24h in vitro. Polymerase chain reaction (PCR) was employed for the mRNA expression of autophagy-related genes, while Western blotting detected the targeted protein expression. The transfection of stub-RFP-sens-GFP-LC3 autophagy-related double fluorescence lentivirus was conducted to detect the level of autophagy flux. Scanning electron microscopy was used to detect the existence of autolysosome. Short interfering RNA of autophagy-related gene (ATG) 7, transient receptor potential vanilloid (TRPV) 1 overexpression plasmid, related agonists and inhibitors were employed to their influence on autophagy related pathway. Flow cytometry was employed to test the apoptosis and intracellular Ca2+ level. Mitochondrial membrane potential was measured by JC-1 staining. The cell counting kit-8 assay was used to calculate the cellular viability. The wound healing assay was used to evaluate the wound closure rate. GraphPad 6.0 software was utilized to evaluate the data. RESULTS: The hyperosmotic stress activated autophagy in a pressure- and time-dependent manner in LECs. Beclin 1 protein expression and conversion of LC3B II to LC3B I increased, whereas sequestosome-1 (SQSTM1) protein expression decreased. Transient Ca2+ influx was stimulated caused by hyperosmotic stress, levels of mammalian target of rapamycin (mTOR) phosphorylation decreased, and the level of AMP-activated protein kinase (AMPK) phosphorylation increased in the early stage. Based on this evidence, autophagy activation through the Ca2+-dependent AMPK/mTOR pathway might represent an adaptation process in LECs under hyperosmotic stress. Hyperosmotic stress decreased cellular viability and accelerated apoptosis in LECs and cellular migration decreased. Inhibition of autophagy by ATG7 knockdown had similar results. TRPV1 overexpression increased autophagy and might be crucial in the occurrence of autophagy promoted by hyperosmotic stress. CONCLUSION: A combination of hyperosmotic stress and autophagy inhibition may be a promising approach to decrease the number of LECs in the capsular bag and pave the way for improving prevention of posterior capsular opacification and capsular fibrosis.

Divergent effects of olfactory receptors on transient receptor potential vanilloid 1 activation by capsaicin and eugenol.

We analyzed the effects of olfactory receptors (ORs) on transient receptor potential vanilloid 1 (TRPV1) activation using HEK293T cells co-expressing TRPV1 and OR51E1. We demonstrate here that the effect of OR51E1 on TRPV1 activation varies depending on the two TRPV1 ligands: capsaicin and eugenol. Notably, both of these ligands are vanilloid analogs. OR51E1 enhanced the response of TRPV1 to capsaicin but diminished that to eugenol. OR51E2 also showed similar effects. Based on the susceptibility to the OR's modulatory effects, various TRPV1 ligands could be classified into capsaicin and eugenol types. Activation of OR51E1 enhanced cAMP production. In addition, forskolin (FSK) exhibited almost identical effects as ORs on TRPV1 responses to both types of ligands. These results suggest that OR51E1-induced cAMP elevation leads to a modification of TRPV1, presumably phosphorylation of TRPV1, which amplifies the susceptibility of TRPV1 to the two types of ligands differently.

Atopic Dermatitis: Managing the Itch.

Atopic dermatitis has a substantial impact on sleep, appearance, psychological well-being, and other qualities of life. The visual appearance of lichenification, cheilitis, hyperpigmentation, ichthyosis, and erythema can be socially stigmatizing, and treatment of these symptoms is challenging. In managing pruritus in patients, practitioners should assess and document pruritus through questionnaires at each routine visit. Initially, practitioners should advise patients to employ nonpharmaceutical treatments such as emollients with wet wraps, elimination of triggers, changing scratching habits, and psychological interventions. If these methods of treatment are not successful or if the disease presentation is severe, pharmacological therapies should be employed. This chapter describes the therapeutic ladder for pruritus in atopic dermatitis and discusses each treatment modality in further detail for practitioners to advise their patients.First-line topical pharmaceutical agents include topical glucocorticoids and topical calcineurin inhibitors. Second-line topical agents include coal tar, menthol, capsaicin, or doxepin. After the use of topical agents has been exhausted, primary systemic agents can be applied. These include sedating antihistamines, nonsedating antihistamines, oral glucocorticoids, or cyclosporine A. Finally, neuromodulating or immunomodulating agents can be attempted, including SSRI/SNRIs, TCAs, immunosuppressants, neural modulators, and opioid receptor modulators. Outside of pharmacological treatments, phototherapy has been shown to provide a dramatic improvement of pruritus in atopic dermatitis and can be used at any stage of treatment including as a first-line agent.

Anti-Nociceptive Effects of Sphingomyelinase and Methyl-Beta-Cyclodextrin in the Icilin-Induced Mouse Pain Model.

The thermo- and pain-sensitive Transient Receptor Potential Melastatin 3 and 8 (TRPM3 and TRPM8) ion channels are functionally associated in the lipid rafts of the plasma membrane. We have already described that cholesterol and sphingomyelin depletion, or inhibition of sphingolipid biosynthesis decreased the TRPM8 but not the TRPM3 channel opening on cultured sensory neurons. We aimed to test the effects of lipid raft disruptors on channel activation on TRPM3- and TRPM8-expressing HEK293T cells in vitro, as well as their potential analgesic actions in TRPM3 and TRPM8 channel activation involving acute pain models in mice. CHO cell viability was examined after lipid raft disruptor treatments and their effects on channel activation on channel expressing HEK293T cells by measurement of cytoplasmic Ca2+ concentration were monitored. The effects of treatments were investigated in Pregnenolone-Sulphate-CIM-0216-evoked and icilin-induced acute nocifensive pain models in mice. Cholesterol depletion decreased CHO cell viability. Sphingomyelinase and methyl-beta-cyclodextrin reduced the duration of icilin-evoked nocifensive behavior, while lipid raft disruptors did not inhibit the activity of recombinant TRPM3 and TRPM8. We conclude that depletion of sphingomyelin or cholesterol from rafts can modulate the function of native TRPM8 receptors. Furthermore, sphingolipid cleavage provided superiority over cholesterol depletion, and this method can open novel possibilities in the management of different pain conditions.