Receptor Potential Cation Channel Subfamily Research Articles

Abstract PR010: TRPV1+ sensory innervation as a novel driver of ovarian cancer progression

Abstract Introduction: A primary challenge currently faced in ovarian cancer (OVCA) treatment is that patient prognoses remain poor despite current therapeutic interventions. Overall survival for OVCA patients with advanced disease is <30%, and most patients recur within 5 years. As such, there is a critical need for new therapies that can overcome OVCA chemoresistance and produce meaningful increases in patient survival. Recent efforts that have targeted the tumor microenvironment (TME), such as immune checkpoint inhibitors, have been successful in some cancers but have limited therapeutic benefit when used to treat OVCA. Thus, new TME targeting therapies must be developed to effectively treat OVCA patients. A novel TME component ripe for therapeutic targeting are the nerve fibers that infiltrate tumors. Recent studies in several cancers have shown that tumor innervation can promote tumor growth/metastasis. However, in ovarian cancer the role of innervation in promoting cancer progression remains a gap in knowledge. Here we show that Transient Receptor Potential Cation Channel Subfamily V Member 1 (TRPV1)+ sensory innervation plays a significant role in driving ovarian cancer progression. Methods: We performed IHC staining to determine the extent of TRPV1+ nerve infiltration in OVCA vs normal reproductive tissue in patients. We examined the ability of OVCA cells to promote tumor innervation using a neurite outgrowth assay. We utilized both syngeneic and patient derived xenograft (PDX) mouse models of ovarian cancer metastasis, where mouse or human OVCA cells were injected intraperitoneally, to explore the functional role of TRPV1+ sensory nerves in OVCA. TRPV1+ sensory nerves were ablated genetically using TRPV1 driven expression of diphtheria toxin alpha (DTA) or chemically using resiniferatoxin. TRPV1+ sensory nerves were activated pharmacologically using capsaicin. Results: Analysis of patient samples showed that TRPV1+ sensory innervation is much higher in ovarian tumors vs benign reproductive tissue. We found that conditioned media from OVCA cells was able to promote neurite outgrowth of dissociated mouse sensory neurons. Ablation of TRPV1+ sensory nerve fibers in vivo caused reduced tumor burden and prolonged survival in our syngeneic and PDX OVCA mouse models. Stimulation of TRPV1+ sensory nerves with capsaicin accelerated OVCA growth and decreased survival in tumor bearing mice. Conclusions: Our results establish TRPV1+ sensory innervation as a novel driver of OVCA growth/metastasis and a potential therapeutic target for OVCA treatment. Significance to tumor microenvironment field: Our data add to a growing body of evidence that sensory nerves are pro-tumorigenic in multiple cancer types and could be therapeutically targeted for cancer treatment. Citation Format: Matthew Knarr, Katherine Cummins, Dusan Racordon, Hunter Reavis, Timothy Lippert, Ryan Hausler, Priyanka Rawat, Jamie Moon, Dave S.B. Hoon, Roger Greenberg, Paola Vermeer, Ronny Drapkin. TRPV1+ sensory innervation as a novel driver of ovarian cancer progression [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr PR010.

3-O-Ethyl Ascorbic Acid and Cannabigerol in Modulating the Phospholipid Metabolism of Keratinocytes

Phospholipids and their metabolites play an important role in maintaining the membrane integrity and the metabolic functions of keratinocytes under physiological conditions and in the regeneration process after exposure to high-energy UVB radiation. Therefore, in the search for compounds with a protective and regenerative effect on keratinocyte phospholipids, the effectiveness of two antioxidant compounds has been tested: a stable derivative of ascorbic acid, 3-O-ethyl ascorbic acid (EAA) and cannabigerol (CBG), both of which are primarily located in the membrane structures of keratinocytes. In addition, this study has demonstrated that EAA and CBG, especially in a two-component combination, enhance the antioxidant properties of keratinocytes and reduce lipid peroxidation assessed at the level of MDA (malondialdehyde)/neuroprostanes. Moreover, by reducing the activity of enzymes that metabolise phospholipids, free PUFAs (polyunsaturated fatty acids) and endocannabinoids (PLA2; phospholipase A2, COX1/2; cyclooxygenases 1/2, LOX-5; lipoxygenase 5, FAAH; fatty acid amide hydrolase, MAGL; monoacylglycerol lipase), antioxidants have been found to regulate the levels of endocannabinoids (AEA; anandamide, 2-AG; 2-arachidonoylglycerol, PEA; palmitoylethanolamide) and eicosanoids (PGD2; prostaglandin D2, PGE2; prostaglandin E2, 15-d-PGJ2; 15-deoxy-Δ12,14-prostaglandin J2, 15-HETE; 15-hydroxyeicosatetraenoic acid), that are enhanced by UVB radiation. The metabolic effect of both groups of PUFA metabolites is mainly related to the activation of G protein-related receptors (CB1/2; cannabinoid receptor 1 and 2, PPARγ; peroxisome proliferator-activated receptor gamma, TRPV1; transient receptor potential cation channel subfamily V member 1), the expression of which is reduced under the influence of EAA, CBG, and especially the two-component combination. It promotes the regeneration of keratinocyte metabolism disrupted by UVB, particularly in relation to redox balance and inflammation.

8515 Role of Insulin Receptor in Trpv1-positive Adipocyte Progenitor Cellsin Adipocyte Differentiation and Metabolic Function

Abstract Disclosure: C. Sahin: None. H. Camara: None. F. Shamsi: None. M. Lynes: None. Y. Tseng: None. Brown adipose tissue (BAT), a specialized fat that dissipates energy to produce heat, is an important endocrine organ in the regulation of energy balance. Stimulating BAT activation and beiging of white adipose tissue (WAT) are new strategies to combat metabolic diseases, such as obesity and diabetes. Traditionally, thermogenic adipocytes are known to originate from mesenchymal Pdgfrα-expressing adipocyte progenitor cells (APCs). A previous study conducted by our lab identified vascular smooth muscle cells as a novel cellular origin of APCs. These cells are characterized by the expression of transient receptor potential cation channel subfamily V member 1 (Trpv1+). With cold exposure, the Trpv1+ APC-derived adipocytes are increased in BAT and WAT and differentiated into highly thermogenic adipocytes. These findings indicate that the Trpv1+-APCs may play an important role in the development of brown and beige adipocytes in response to cold. This study was designed to explore the function of the Trpv1+ APC-derived adipocytes in thermogenic adipocyte differentiation and metabolic regulation. We generated a mouse model in which insulin receptor (IR), a well-known player in adipocyte differentiation, was deleted in the Trpv1+ APCs to impair their adipogenic potential. Trpv1-Cre::mTmG::IRflox transgenic and IRwt control mice were housed at cold temperature (5°C) for 7 days. Because the lineage tracing mTmG system was included, we were able to trace the fate of Trpv1+ APCs in the presence or absence of IR. We first examined the adipogenic capacity of the IR-deficient Trpv1+ cells in BAT and WAT tissues using whole-mounted adipose tissue imaging. In control mice, approximately 30% of all mature adipocytes were derived from Trpv1+ APCs in adipose tissue in response to cold. With ablation of IR in Trpv1+ APCs, this contribution was significantly reduced in BAT (by 11.7 % in females; 6.1% in males), inguinal WAT (by 16.8% in females; 19.3% males), and perigonadal WAT (by 11.4% in females; 14.8% in males) in transgenic mice compared to control mice. These results showed that IR-deficiency in the Trpv1-expressing cells impaired their adipogenesis in both male and female mice. In contrast, thermogenic genes (e.g., Ucp1, Pparγc1a, Cox7a1) were not significantly altered in BAT and inguinal WAT of the IR-deficient Trpv1+ APCs mice. Despite the changes in the adipocyte populations, we observed that deletion of IR in Trpv1+ APCs has no impact on body weight, food intake, fat mass, glucose tolerance, and insulin sensitivity relative to control mice. Taken together, blocking the contribution of Trpv1+ APCs to the mature adipocyte population results in no metabolic changes in mice, suggesting that the other APCs, such as PdgfRα+ APCs, may potentially compensate for impaired adipogenesis in different adipose tissues. Presentation: 6/1/2024

Methylcobalamin as a candidate for chronic peripheral neuropathic pain therapy: review of molecular pharmacology actiona.

Chronic peripheral neuropathic pain therapy currently focuses on modulating neuroinflammatory conditions. Methylcobalamin (MeCbl), a neuroregenerative agent, modulates neuroinflammation. This review aimed to explore the molecular pharmacology action of MeCbl as a chronic peripheral neuropathic pain therapeutic agent. MeCbl plays a role in various cellular processes and may have therapeutic potential in neurodegenerative diseases. Intracellular MeCbl modulates inflammation by regulating the activity of T lymphocytes and natural killer cells as well as secretion of inflammatory cytokines, namely, tumor necrosis factor-α, interleukin-6, interleukin-1β, epidermal growth factor, and neuronal growth factor. MeCbl can reduce pain symptoms in chronic neuropathic pain conditions by decreasing excitation and hyperpolarization-induced ion channel activity in medium-sized dorsal root ganglion (DRG) neurons and the expression of transient receptor potential ankyrin 1, transient receptor potential cation channel subfamily M member 8, phosphorylated p38MAPK, transient receptor potential cation channel subfamily V members 1 and 4 in the DRG, and the voltage-gated sodium channel in axons.

Mild therapeutic hypothermic protection activates the PI3K/AKT signaling pathway to inhibit TRPM7 and suppress ferroptosis induced by myocardial ischemia‑reperfusion injury.

The present study aimed to investigate the role of PI3K‑mediated ferroptosis signaling induced by mild therapeutic hypothermia (MTH), which was defined as a temperature of 34˚C, in protecting against myocardial ischemia-reperfusion (I/R) injury (MIRI). To meet this aim, H9C2 cells underwent hypoxia‑reperfusion (H/R) and/or MTH. The MTT assay was used to assess cell viability, cytotoxicity was measured using a lactate dehydrogenase cytotoxicity assay, and Annexin V‑FITC/PI flow cytometric analysis was used to analyze early and late cell apoptosis. In addition, 84 healthy adult male Sprague‑Dawley rats were randomly divided into seven groups (n=12), and underwent I/R and various treatments. Hemodynamics were monitored, and the levels of myocardial injury marker enzymes and oxidative stress markers in myocardial tissue were measured using ELISA. The expression levels of PI3K, AKT, transient receptor potential cation channel subfamily M member 7 (TRPM7), glutathione peroxidase 4 (GPX4) and acyl‑CoA synthetase long chain family member 4 (ACSL4) in animals and cells were measured using western blot analysis. These experiments revealed that MTH could effectively reduce myocardial infarct size, improve hemodynamic performance following MIRI and suppress myocardial apoptosis, thereby contributing to the recovery from H/R injury. Mechanistically, MTH was revealed to be able to activate the PI3K/AKT signaling pathway in cells, upregulating GPX4, and downregulating the expression levels of TRPM7 and ACSL4. Treatment with 2‑aminoethoxydiphenyl borate (an inhibitor of TRPM7) could further strengthen the myocardial protective effects of MTH, whereas treatment with erastin (promoter of ferroptosis) and wortmannin (inhibitor of PI3K) led to the effective elimination of the myocardial protective effects of MTH. Compared with in the I/R group, the PI3K/AKT activation level and the expression levels of GPX4 were both significantly increased, whereas the expression levels of TRPM7 and ACSL4 were significantly decreased in the I/R + MTH group. Taken together, the results of the present study indicated that MTH may activate the PI3K/AKT signaling pathway to inhibit TRPM7 and suppress ferroptosis induced by MIRI.

MUC1‑ND interacts with TRPV1 to promote corneal epithelial cell proliferation in diabetic dry eye mice by partly activating the AKT signaling pathway.

Although both mucin1 (MUC1) and transient receptor potential cation channel subfamily V member 1 (TRPV1) have been reported to be associated with dry eye (DE) disease, whether they interact and their regulatory roles in diabetic DE disease are unknown. Diabetic DE model mice were generated by streptozotocin induction and assessed by corneal fluorescein staining, tear ferning (TF) tests, phenol red thread tests, hematoxylin and eosin staining of corneal sections and periodic acid Schiff staining of conjunctival sections. Cell proliferation was measured by CCK8 assay. Western blotting was performed to measure protein expression. Primary mouse corneal epithelial cells (MCECs) were cultured after enzymatic digestion. Immunofluorescence staining of MCECs and frozen corneal sections was conducted to assess protein expression and colocalization. Coimmunoprecipitation was performed to detect protein‑protein interactions. It was found that, compared with control mice, diabetic DE mice exhibited increased corneal epithelial defects, reduced tear production, poorer TF pattern grades and impaired corneal and conjunctival tissues. In vivo and in vitro experiments showed that hyperglycemia impaired cell proliferation, accompanied by decreased levels of the MUC1 extracellular domain (MUC1‑ND) and TRPV1. Additionally, it was found that capsazepine (a TRPV1 antagonist) inhibited the proliferation of MCECs. Notably, MUC1‑ND was shown to interact with the TRPV1 protein in the control group but not in the diabetic DE group. It was also found that the AKT signaling pathway was attenuated in the diabetic DE mice and downstream of TRPV1. MUC1‑ND interacted with TRPV1, partly activating the AKT signaling pathway to promote MCEC proliferation. The present study found that the interaction of MUC1‑ND with TRPV1 promotes MCEC proliferation by partly activating the AKT signaling pathway, providing new insight into the pathogenesis of corneal epithelial dysfunction in diabetic DE disease.

Tet1-mediated activation of the Ampk signaling by Trpv1 DNA hydroxymethylation exerts neuroprotective effects in a rat model of Parkinson's disease.

Epigenetic regulation plays a role in Parkinson's disease (PD), and ten-eleven translocation methylcytosine dioxygenase 1 (TET1) catalyzes the first step in DNA demethylation by converting 5-methylcytosine to 5-hydroxymethylcytosine. We investigated whether TET1 binds to the promoter of the transient receptor potential cation channel subfamily V member 1 (TRPV1) and regulates its expression, thereby controlling oxidative stress in PD. TRPV1 was identified as an oxidative stress-associated gene in the GSE20186 dataset including substantia nigra from 14 patients with PD and 14 healthy controls and the Genecards database. Lentiviral vectors were used to manipulate Trpv1 expression in rats, followed by 6-hydroxydopamine hydrochloride (6-OHDA) injection for modeling. Behavioral tests, immunofluorescence, Nissl staining, western blot assays, DHE fluorescent probe, biochemical analysis, and ELISA were conducted to assess oxidative stress and neurotoxicity. Trpv1 expression was significantly reduced in the brain tissues of 6-OHDA-treated Parkinsonian rats. Trpv1 alleviated behavioral dysfunction, oxidative stress, and dopamine neuron loss in rats. TET1 mediated TRPV1 hydroxymethylation to promote its expression, and Trpv1 inhibition reversed the mitigating effect of Tet1 on oxidative stress and behavioral dysfunction in PD. TRPV1 activated the AMPK signaling by promoting AMPK phosphorylation to alleviate neurotoxicity and oxidative stress in SH-SY5Y cells. Tet1-mediated Trpv1 hydroxymethylation modification promotes the Ampk signaling activation, thereby eliciting neuroprotection in 6-OHDA-treated Parkinsonian rats. These findings provide experimental evidence that targeting the TET1/TRPV1 axis may be neuroprotective for PD by acting on the AMPK signaling.

Capsaicin modulates TRPV1, induces β-defensin expression, and regulates NF-κB in oral senescent cells and a murine model.

Aging is associated with a decline in oral immune function, marked by reduced levels of antimicrobial peptides such as defensins. Capsaicin, a bioactive component found in chili peppers, has been theorized to modulate immune responses through specific receptor pathways. This study examined the effects of aging on oral defensin levels and the potential mitigating role of capsaicin, mediated by the immune response in oral tissues. We conducted a comparative analysis between young and aged mice, with or without capsaicin supplementation, for 3 months. The effect of capsaicin was also studied in vitro in senescence-induced human oral keratinocytes. We found that aging did not reduce defensin levels uniformly but did so in some instances. Capsaicin treatment increased defensin levels in these cases, potentially through transient receptor potential cation channel subfamily V member 1 (TRPV1)-mediated pathways in the oral cavity. Capsaicin supplementation may counteract age-related declines in oral defensin levels, enabling the maintenance of oral immune function during aging.

David Julius and Ardem Patapoutian: Pioneers in Sensory Biology and Neuroscience.

Sensory biology is a critical area within neuroscience, exploring how organisms respond to environmental stimuli such as temperature, pain, and mechanical forces. David Julius and Ardem Patapoutian have made landmark contributions to this field by identifying crucial receptors. Julius's discovery of transient receptor potential (TRP) channels, including transient receptor potential cation channel subfamily V member 1 (TRPV1), which detects heat and pain, revolutionized sensory biology and opened new paths for pain management. Similarly, Patapoutian's identification of Piezo channels, which respond to mechanical stimuli like touch and pressure, has deepened our understanding of sensory perception. Their combined work has not only advanced scientific knowledge but also introduced potential treatments for chronic pain and sensory disorders. This paper reviews their contributions and the broader implications for sensory biology and therapeutic developments.

A proteomics-based study of the mechanism of oxymatrine to ameliorate hepatic fibrosis in mice

ObjectiveThis study investigated the protective effect of oxymatrine (OMT) on carbon tetrachloride (CCl4)-induced hepatic fibrosis in mice and explored its possible targets and signaling pathways. MethodsMale BALB/c mice were randomly divided into blank control, model, positive drug (silymarin), and OMT administration groups, respectively, with 10 mice in each group. Hepatic fibrosis was induced in mice using CCl4 and the corresponding drug intervention was given. After the final administration, ultrasonography tests, blood tests, and analysis of liver differential proteins using tandem mass tag labeling and liquid chromatography-mass spectrometry were performed. ResultsOMT intervention ameliorated CCl4-induced hepatic fibrosis in mice, significantly reduced serum alanine aminotransferase and aspartate aminotransferase levels, down-regulated the expression of fibrosis factors, such as type IV collagen IV, laminin, type III procollagen III, and alpha-smooth muscle actin, and improved liver function. The results of the proteomic analysis showed that the intervention of OMT significantly down-regulated 130 out of 440 up-regulated proteins and up-regulated 70 out of 294 down-regulated proteins, primarily involving the transient receptor potential (TRP) signaling pathway, the peroxisome proliferator-activated receptors (PPAR) signaling pathway, and the metabolic pathway of arachidonic acid. The main differential proteins involved were Cyp2c37, SCP-2, and Tbxas1. In addition, OMT intervention significantly reversed the expression of sterol carrier protein-2 (SCP2) and upregulated the expression of peroxisome proliferator-activated receptor gamma, Cyp2c37, and transient receptor potential cation channel subfamily V member 1 proteins. ConclusionOMT inhibited the proliferative capacity of hepatic stellate cells, induced apoptotic properties, and suppressed the development of fibrosis by elevating Cyp2c37/TRP signaling axis activity and upregulating PPAR pathway activity by inhibiting SCP2.

TRPM2-AS promotes ovarian cancer cell proliferation and inhibits cell apoptosis by upregulating the nearby gene TRPM2 via miR-6764-5p

Ovarian cancer (OC) becomes a fatal gynecologic malignant cancer in females worldwide. Target therapy is a promising therapeutical choice for patients with OC, and identifying biomarkers and exploring molecular mechanisms are necessary. In this study, the functions and mechanism of long noncoding RNA transient receptor potential cation channel subfamily M member 2 antisense RNA (TRPM2-AS) in OC were explored. TRPM2-AS expression in OC cells was analyzed utilizing reverse transcription quantitative polymerase chain reaction (RT-qPCR). Cell counting kit-8 (CCK-8) and colony forming assays were carried out to explore the influence of TRPM2-AS on OC cell viability and proliferation. Cell apoptosis was detected using TdT-mediated dUTP Nick-End labeling (TUNEL) and flow cytometry analysis. Protein expression of apoptotic markers was subjected to western blotting. RNA pulldown or luciferase reporter assays were applied to explore the interaction between TRPM2-AS and miR-6764-5p or the binding of miR-6764-5p and TRPM2. The results showed that TRPM2-AS is highly expressed in OC cells and was mainly localized in cytoplasm. TRPM2-AS depletion suppressed OC cell viability and proliferation while increasing cell apoptotic rate. TRPM2 displayed a high level in OC cells and was positively regulated by TRPM2-AS. TRPM2-AS interacted with miR-6764-5p and thereby upregulated TRPM2 expression. In addition, TRPM2 overexpression reversed the repressive impact of TRPM2-AS depletion on malignant OC cellular process. In conclusion, TRPM2-AS promotes OC cell viability and proliferation while enhancing cell apoptosis through interaction with miR-6764-5p to regulate TRPM2 level.

Abstract Mo037: Cardiac-Selective TRPV1 Afferent Ablation in Subacute Myocardial Infarction Ameliorates Adverse Remodeling and Ventricular Arrhythmogenesis

Background: Ventricular arrhythmias (VT/VF), the most common cause of sudden death after myocardial infarction (MI), can be ameliorated by cardiac-selective transient receptor potential cation channel subfamily V member 1 (TRPV1) afferent ablation at the time of infarction in animal models. To enable translation to human, it remains unknown whether afferent depletion in the subacute phase of MI will reduce arrhythmias and mitigate long-term structural remodeling. Objectives: To assess the role of cardiac-selective TRPV1 afferent ablation two weeks after MI on the long-term ventricular arrhythmogenesis and adverse structural remodeling. Methods: Yorkshire pigs were randomized to resiniferatoxin (RTX 5.0µg/ml: n=10) or vehicle(n=6) 14days after the left anterior descending artery infarct. Four weeks later, terminal experiments were conducted to evaluate the effect of RTX on cardiac structural and functional remodeling, ventricular arrhythmogenesis, and autonomic reflex function. Results: Cardiac afferent depletion via RTX administration was confirmed by diminished sympathetic response to TRPV1 agonists (bradykinin and capsaicin) and by immunohistochemical analysis of ventricular innervation. Compared to the vehicle treated group, the RTX administration reduced LV dimension (p<0.01), repolarization heterogeneity (p<0.01) and ventricular arrhythmogenesis (program stimulation; p=0.01 and CsCl induced PVCs;p<0.01). In the scar-border zone, myocytolysis and nerve sprouting, which are associated with VT/VF, were attenuated in the RTX group (abnormality score; p=0.01 and nerve sprouting index; p < 0.01). T cell infiltration in dorsal root ganglia was suppressed in the RTX group (p = 0.02). RNA-sequencing of stellate ganglia revealed downregulation of adrenergic genes tyrosine hydroxylase and neuropeptide-Y in the RTX group. Taken together, these results suggest that cardiac afferent ablation in subacute MI alleviates adverse structural remodeling and ventricular arrhythmogenesis by targeting neuroinflammation and reducing stellate ganglion sympathetic overexcitation. Conclusion: Cardiac TRPV1 afferent depletion in subacute MI is a promising disease altering treatment for patients suffering from MI.

METTL3/IGF2BP1 influences the development of non-small-cell lung cancer by mediating m6A methylation modification of TRPV1.

Methyltransferase 3 (METTL3) accelerates N6-methyladenosine (m6A) modifications and affects cancer progression, including non-small-cell lung cancer (NSCLC). In this study, we aimed to explore the regulatory mechanisms of METTL3 underling NSCLC. Immunohistochemical assay, quantitative real-time polymerase chain reaction (qRT-PCR)assay, and western blot assay were conducted for gene expression. MTT assay and colony formation assay were performed to explore cell proliferation capacity. Cell apoptosis and THP-1 cell polarization were estimated by flow cytometry analysis. Cell migration and invasion capacities were evaluated by transwell assay. Methylated RNA immunoprecipitation assay, dual-luciferase reporter assay, actinomycin D treatment and RIP assay were performed to analyze the relationships of METTL3, insulin-like growth factor 2 mRNA binding protein 1 (IGF2BP1), and transient receptor potential cation channel subfamily V member 1 (TRPV1). The functions of METTL3 and TRPV1 in vivo were investigated through establishing the murine xenograft model. TRPV1 expression was upregulated in NSCLC and related poor prognosis. TRPV1 silencing inhibited NSCLC cell growth and metastasis, induced NSCLC cell apoptosis, and repressed M2 macrophage polarization. The results showed that METTL3 and IGF2BP1 could regulate TRPV1 expression through m6A methylation modification. Moreover, METTL3 deficiency inhibited NSCLC cell growth, metastasis, and M2 macrophage polarization and facilitated NSCLC cell apoptosis, while TRPV1 overexpression restored the impacts. In addition, METTL3 knockdown restrained tumor growth in vivo via regulating TRPV1 expression. METTL3 bound to IGF2BP1 and enhanced IGF2BP1's m6A recognition of TRPV1 mRNA, thereby promoting NSCLC cell growth and metastasis, and inhibiting M2 macrophage polarization.

The TRPA1 Ion Channel Mediates Oxidative Stress-Related Migraine Pathogenesis.

Although the introduction of drugs targeting calcitonin gene-related peptide (CGRP) revolutionized migraine treatment, still a substantial proportion of migraine patients do not respond satisfactorily to such a treatment, and new therapeutic targets are needed. Therefore, molecular studies on migraine pathogenesis are justified. Oxidative stress is implicated in migraine pathogenesis, as many migraine triggers are related to the production of reactive oxygen and nitrogen species (RONS). Migraine has been proposed as a superior mechanism of the brain to face oxidative stress resulting from energetic imbalance. However, the precise mechanism behind the link between migraine and oxidative stress is not known. Nociceptive primary afferent nerve fiber endings express ion channel receptors that change harmful stimuli into electric pain signals. Transient receptor potential cation channel subfamily A member 1 (TRPA1) is an ion channel that can be activated by oxidative stress products and stimulate the release of CGRP from nerve endings. It is a transmembrane protein with ankyrin repeats and conserved cysteines in its N-terminus embedded in the cytosol. TRPA1 may be a central element of the signaling pathway from oxidative stress and NO production to CGRP release, which may play a critical role in headache induction. In this narrative review, we present information on the role of oxidative stress in migraine pathogenesis and provide arguments that TRPA1 may be "a missing link" between oxidative stress and migraine and therefore a druggable target in this disease.

Neuregulin 1 mitigated prolactin deficiency through enhancing TRPM8 signaling under the influence of melatonin in senescent pituitary lactotrophs

The age-related alterations in pituitary function, including changes in prolactin (PRL) production contributes to the systemic susceptibility to age-related diseases. Our previous research has shown the involvement of Nrg1 in regulating the expression and secretion of PRL. However, the precise role of Nrg1 in mitigating the senescence of pituitary lactotrophs and the underlying mechanisms are yet to be comprehended. Here, data from the GEPIA database was used to evaluate the association between transient receptor potential cation channel subfamily M member 8 (TRPM8) and PRL in normal human pituitary tissues, followed by immunofluorescence verification using a human pituitary tissue microarray. TRPM8 levels showed a significant positive association with PRL expression in normal human pituitary tissues, and both TRPM8 and PRL levels declined during aging, suggesting that TRPM8 may regulate pituitary aging by affecting PRL production. It was also found that treatment with exogenous neuregulin 1 (Nrg1) markedly delayed the senescence of GH3 cells (rat lactotroph cell line) generated by D-galactose (D-gal). In addition, melatonin reduced the levels of senescence-related markers in senescent pituitary cells by promoting Nrg1 / ErbB4 signaling, stimulating PRL expression and secretion. Further investigation showed that Nrg1 attenuated senescence in pituitary cells by increasing TRPM8 expression. Downregulation of TRPM8 activation eliminated Nrg1-mediated amelioration of pituitary cell senescence. These findings demonstrate the critical function of Nrg1 / ErbB signaling in delaying pituitary lactotroph cell senescence and enhancing PRL production via promoting TRPM8 expression under the modulation of melatonin.

Effects of Cannabinoids on Intestinal Motility, Barrier Permeability, and Therapeutic Potential in Gastrointestinal Diseases.

Cannabinoids and their receptors play a significant role in the regulation of gastrointestinal (GIT) peristalsis and intestinal barrier permeability. This review critically evaluates current knowledge about the mechanisms of action and biological effects of endocannabinoids and phytocannabinoids on GIT functions and the potential therapeutic applications of these compounds. The results of ex vivo and in vivo preclinical data indicate that cannabinoids can both inhibit and stimulate gut peristalsis, depending on various factors. Endocannabinoids affect peristalsis in a cannabinoid (CB) receptor-specific manner; however, there is also an important interaction between them and the transient receptor potential cation channel subfamily V member 1 (TRPV1) system. Phytocannabinoids such as Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) impact gut motility mainly through the CB1 receptor. They were also found to improve intestinal barrier integrity, mainly through CB1 receptor stimulation but also via protein kinase A (PKA), mitogen-associated protein kinase (MAPK), and adenylyl cyclase signaling pathways, as well as by influencing the expression of tight junction (TJ) proteins. The anti-inflammatory effects of cannabinoids in GIT disorders are postulated to occur by the lowering of inflammatory factors such as myeloperoxidase (MPO) activity and regulation of cytokine levels. In conclusion, there is a prospect of utilizing cannabinoids as components of therapy for GIT disorders.

(003) LOCALIZED PROVOKED VULVODYNIA: THE ROLE OF CYCLOOXYGENASE ENZYMES IN PROMOTING INFLAMMATION AND PAIN SIGNALING

Abstract Introduction Localized provoked vulvodynia (LPV) is a chronic condition in which patients experience disabling pain in the vulvar vestibule. This condition’s mechanisms are poorly understood, and the lack of adequate treatment reflects the misunderstanding of the disease’s origins. Many LPV patients attempt to treat their pain with NSAIDS, but their use has been clinically shown to be ineffective against LPV associated vulvar pain. Recent evidence, utilizing fibroblasts isolated from vestibular and vulvar tissue of LPV patients, supports a link between inflammation and symptomology of LPV. These fibroblasts have shown to be sensitive to pro-inflammatory stimuli and overproduce inflammatory mediators such as Interleukin-6 (IL-6) and Prostaglandin E2 (PGE2). Increased production of IL-6 and PGE2 correlates with decreased pain thresholds, endorsing these levels as a surrogate measure for pain. Lipidomic data collected via mass spectroscopy also demonstrates LPV fibroblast strains have dysregulated arachidonic acid metabolism, resulting in an imbalance in pro-resolving lipids. Utilizing this fibroblast model, different cyclooxygenase (COX) inhibitors were used to better illuminate the mechanism behind fibroblast inflammation in LPV. Objective Using a fibroblast cell model, we set out to better understand pathophysiology of LPV and use that information to guide development of effective and pragmatic medical treatments. Methods Fibroblast strains were generated from vulvar and vestibular tissue samples of LPV patients and non-LPV age and race-matched controls. These cells were then treated with Interleukin 1 beta (IL-1β), selective cyclooxygenase-1 inhibitor (SC560), celecoxib (selective COX-2 inhibitor), and ibuprofen (nonselective COX inhibitor) to investigate differences in cellular response when blocking different enzymes in the inflammatory pathway. IL-1β is known to induce IL-6 and PGE2 which acted as a positive control. Results were then quantified via ELISA assay. Results Vestibular and vulvar tissues showed an increase in IL-6 and PGE2 production following treatment with IL-1B. When concurrently treated with IL-1B (to stimulate inflammation) and SC560 (to inhibit COX-1 signaling) ELISA analysis showed a significant decrease in PGE2. A significant PGE2 decrease was shown with concurrent IL-1B/Ibuprofen treatment as well as with IL-1B/Celecoxib treatments. In all three cases, IL-6 signaling was generally not decreased, while PGE2 was decreased, but not to baseline levels. Ibuprofen treatment in fact showed a trend towards increased IL-6 production. Conclusions Fibroblast response to inflammation in the case of LPV is complex. COX inhibitors do not fully inhibit the pain signaling that contributes to the symptomology of LPV patients (IL-6 production remains elevated). NSAIDs leave patients with dysregulated inflammation cascades, which does not remediate pain. Future areas of study for pharmaceutical targets include investigating lipid regulation, other pain signaling mechanisms, such as transient receptor potential cation channel subfamily V member 4 (TRPV4), and combination topical NSAID use to create more appropriate and robust treatment for patients with LPV. Disclosure Any of the authors act as a consultant, employee or shareholder of an industry for: SPM Therapeutics.

Alterations of the peptidomic composition of peripheral plasma after portal hypertension correction by transjugular intrahepatic portosystemic shunt

Portal hypertension develops in patients with advanced chronic liver diseases (CLD), especially cirrhosis and is associated with complications, such as gastrointestinal bleeding and ascites resulting in high mortality. The transjugular intrahepatic portosystemic shunt (TIPS) is a treatment option for portal hypertension, aiming to decrease portal venous pressure by establishing an artificial passage for blood from the gastrointestinal tract to the liver vein. This study focuses on the differences in the molecular composition of plasma samples from patients with portal hypertension before and after TIPS intervention to identify and characterise potential mediators influencing gut-liver cross-talk. The plasma of 23 patients displaying advanced CLD with portal hypertension was collected from peripheral veins before and after TIPS treatment and analysed using a well-established non-targeted chromatography-mass spectrometric (LC-MS) approach. Sialomucin core protein 24(CD164)(160–180), meckelin(99-118), Histone-lysine N-methyltransferase(MLL3)(3019-3045) and transient receptor potential cation channel subfamily V member 5(TRPV5)(614-630) were identified to be downregulated after the TIPS treatment. In addition, the metabolites 3-carboxy-4-methyl-5-propyl-2-furanpropionic acid (CMPF), uric acid, dopamine, homoarginine, leucylproline and 5-methyluridine were significantly decreased after TIPS, whereas one yet unidentified low molecular-weight metabolite showed an increase after the medical procedure. In conclusion, these substances are novel potential biomarkers for portal hypertension in patients with CLD, with mechanistic clues of involvement in regulating pathological gut-liver cross-talk.

Serum TRPA1 mediates the association between olfactory function and cognitive function.

Olfactory dysfunction was associated with poorer cognition. However, the association between transient receptor potential cation channel subfamily A member 1 (TRPA1) and cognitive function have not been studied. This study aimed to evaluate the mediation effect of TRPA1 on the association between olfactory and cognitive function among Chinese older adults. We recruited 121 participants with cognitive impairment (CI) and 135 participants with normal cognition (NC) from a memory clinic and the "Shanghai Aging Study." Olfactory identification of each participant was measured by the Sniffin' Sticks Screening Test 12 (SSST-12). Serum TRPA1 were quantified using the Enzyme-Linked Immunosorbent Assay. The mediation effects of TRPA1 on the association between olfactory function and cognitive function were explored using mediation analysis. The CI group had a significantly higher proportion of the high level of serum TRPA1 (58.7%) than the NC group (42.2%) (p = 0.0086). After adjusted for gender, age, and years of education, mediation analysis verified that TRPA1 partially mediated the association between SSST-12 and Mini Mental State Examination (MMSE). It also verified that TRPA1 partially mediated the association between the identification of peppermint and MMSE. Our study emphasizes the mediation role of TRPA1 in the relationship between olfactory and cognitive function among older adults. Further research is necessary to explore the mechanism of TRPA1 on the relationship between olfactory and cognitive decline.

Graphdiyne as a Highly Efficient and Neuron-Targeted Photothermal Transducer for in Vivo Neuromodulation.

Photothermal modulation of neural activity offers a promising approach for understanding brain circuits and developing therapies for neurological disorders. However, the low neuron selectivity and inefficient light-to-heat conversion of existing photothermal nanomaterials significantly limit their potential for neuromodulation. Here, we report that graphdiyne (GDY) can be developed into an efficient neuron-targeted photothermal transducer for in vivo modulation of neuronal activity through rational surface functionalization. We functionalize GDY with polyethylene glycol (PEG) through noncovalent hydrophobic interactions, followed by antibody conjugation to specifically target the temperature-sensitive transient receptor potential cation channel subfamily V member 1 (TRPV1) on the surface of neural cells. The nanotransducer not only exhibits high photothermal conversion efficiency in the near-infrared region but also shows great TRPV1-targeting capability. This enables photothermal activation of TRPV1, leading to neurotransmitter release in cells and modulation of neural firing in living mice. With its precision and selectivity, the GDY-based transducer provides an innovative avenue for understanding brain function and developing therapeutic strategies for neurodegenerative diseases.