Search Results (467)

The vitamin D receptor (VDR) acts as both a nuclear transcription factor and a non-genomic mediator that regulates a broad spectrum of physiological processes beyond calcium and phosphate homeostasis. VDR plays an important role in the modulation of ion channels across multiple tissues, including osteoblasts, renal and intestinal epithelial cells, neurons, and vascular smooth muscle. These regulatory mechanisms encompass genomic actions through vitamin D response elements in target genes—such as TRPV5, TRPV6, KCNK3, and KCNH1—as well as rapid, non-genomic actions at the plasma membrane involving protein disulfide isomerase A3 and associated signaling cascades. VDR-mediated transcriptional control of calcium, potassium, and chloride channels contributes to the fine-tuning of cellular excitability, calcium transport, and mitochondrial function. Evidence also implicates VDR–ion channel crosstalk in various pathological contexts, including renal cell carcinoma, breast and cervical cancers, pulmonary arterial hypertension, and osteoporosis. Understanding the molecular interplay between VDR and ion channels provides new perspectives on the pleiotropic effects of vitamin D and offers promising therapeutic opportunities in oncology, cardiovascular disease, and skeletal disorders. This review synthesizes previous and current evidence on the genomic and non-genomic mechanisms underlying VDR–ion channel regulation and highlights novel frontiers in vitamin D signaling relevant to human health and disease. Full article

Tyrosine kinases (TKs) are drug targets in diffuse intrinsic pontine glioma (DIPG). Ion channels are emerging targets in cancer. TKIs targeting different kinases such as everolimus, crizotinib, dasatinib, erlotinib, lapatinib, perifosine and midostaurin (0.001–100 μM) were investigated on cell proliferation and ion channel currents. Methods: Cell viability assays in parallel with a patch-clamp study and Western blot of target proteins are performed in SU-DIPG-36 and SU-DIPG-50 cells. Results: Midostaurin is the most effective drug in different assays. Patch-clamp investigations show that the application of midostaurin reduced the inward and outward whole-cell cation channel currents vs. controls in the presence of low internal ATP. These currents were sensitive to the KATP channel inhibitors glibenclamide and repaglinide and were fully reduced by the unselective blocker TEA-BaCl₂. Midostaurin also reduced currents that are sensitive to TRPV1 channel blockers capsazepine and ruthenium-red. The IC₅₀ values of midostaurin as an antiproliferative drug and ion channel inhibitor in either cell line are in the sub-micromolar range. In SU-DIPG-36 cells midostaurin causes a concentration-dependent upregulation of autophagy markers. Conclusions: The inhibition of cation channel currents by midostaurin in SU-DIPG-36 and SU-DIPG-50 cells and the autophagy potentiation in SU-DIPG-36 cells can be novel mechanisms in DIPG. Full article

Transient receptor potential vanilloid 4 (TRPV4) is a polymodal cation channel that is widely expressed in sensory neurons, immune cells, and structural tissues, where it integrates mechanical, osmotic, and chemical stimuli to regulate both physiological responses and disease-associated signaling. Mast cells (MCs), key immune effector cells capable of rapid mediator release through degranulation, also express TRPV4. Increasing evidence supports TRPV4-MC signaling as an important neuroimmune interface, linking mechanical and inflammatory stimuli to tissue hypersensitivity and pain. In this review, we synthesize current evidence supporting a role for TRPV4 in MC-associated neuroimmune signaling across multiple disease contexts while distinguishing settings in which TRPV4 directly regulates MC activation from those in which MC responses arise through multicellular tissue interactions. Direct TRPV4-dependent MC activation has been described in conditions such as LL-37–driven rosacea and mechanically induced inflammation, whereas in disorders including asthma, visceral hypersensitivity, bladder pain syndromes, and osteoarthritis, TRPV4 activity in epithelial, neuronal, or stromal compartments more often influences MC function indirectly through ATP–purinergic signaling, cytokine release, and neuropeptide-mediated crosstalk. Across systems, TRPV4 emerges not as a single pathogenic switch but as part of a context-dependent signaling network whose functional consequences depend on cell type, tissue microenvironment, and disease stage. Altogether, these findings identify TRPV4 as a therapeutically actionable node within neuroimmune signaling pathways and support the development of tissue-specific and combination strategies targeting both TRPV4 activity and MC-mediated signaling in chronic inflammatory and pain disorders. Full article

Dry eye disease (DED) is an ocular surface disorder characterized by tear film instability, inflammation, epithelial damage, and neurosensory abnormalities. Due to its multifactorial etiology and pathophysiology, conventional therapies that focus on lubrication and immunosuppression often fall short in addressing the neuropathic component of ocular pain experienced by a growing subset of patients. Recent developments in sensory neuroscience have highlighted the pivotal role of ion channels in mediating ocular surface homeostasis, pain signaling, and inflammation. This review examines the role of the following major ion channel families in the pathophysiology of DED and neuropathic ocular pain: transient receptor potential (TRP) channels, voltage-gated sodium (Nav) channels, and purinergic P2X receptors. The review details their anatomical distribution, molecular function, and responses to environmental stimuli such as heat, cold, osmolarity, and injury. Current treatments, such as artificial tears, anti-inflammatory drops, and systemic neuromodulators, are also reviewed in relation to their effects on ion channel modulation. Additionally, emerging therapies that directly target sensory transduction pathways are introduced. This review highlights the therapeutic potential of ion channel modulation in personalizing treatment for patients with ocular surface pain, particularly those with neuropathic features unresponsive to standard care. Full article

Cardiovascular disease (CVD) remains the leading cause of morbidity and mortality worldwide, necessitating a deeper understanding of novel regulatory mechanisms and therapeutic targets. Transient receptor potential vanilloid subtype 1 (TRPV1), a non-selective cation channel extensively expressed in the cardiovascular system, has been implicated in the pathogenesis and progression of various CVDs, including myocardial infarction, ischemia–reperfusion injury, adverse cardiac remodeling, heart failure, hypertension, and diabetes. Recent studies demonstrate that TRPV1 modulates key signaling pathways associated with inflammation, oxidative stress, mitochondrial function, and apoptosis, exerting both protective and detrimental effects depending on specific disease contexts and experimental conditions. The dual regulatory roles of TRPV1, mediated through pathways such as TRPV1/CGRP/SP and TRPV1/eNOS/NO, underline its complexity and clinical relevance. This review summarizes current findings on the expression and function of TRPV1 in diverse cardiovascular tissues and models, critically evaluates its role in CVD pathophysiology, and discusses the therapeutic potential of modulating TRPV1-associated signaling. Understanding these mechanisms may provide valuable insights into developing precise intervention strategies against cardiovascular diseases. Full article

Protease-activated receptor 2 (PAR2) is a G protein-coupled receptor (GPCR) expressed in both the peripheral and central nervous systems. It plays a pivotal role in mediating neuroimmune interactions, particularly in the context of inflammation and pain. Upon activation by proteases, PAR2 modulates nociception through signaling cascades that influence key ion channels, including transient receptor potential (TRP) ion channels vanilloid 1 and 4 (TRPV1 and TRPV4), ankyrin 1 (TRPA1), acid-sensing ion channel 3 (ASIC3), P2X purinoceptor 3 (P2X3), Cav3.2 (T-type Ca²⁺ channel), and potassium Kv7 (M-current) channels, altering their expression and function. Through this crosstalk, PAR2 contributes to heightened neuronal excitability and pain hypersensitivity in various inflammatory conditions. In this narrative review, we highlight and discuss the mechanistic and functional interplay between PAR2 and nociceptive ion channels, which might be contributing to the pathogenesis of inflammatory pain. Targeting these specific molecular interactions between PAR2 and nociceptive ion channels may offer a promising therapeutic strategy for treating inflammatory pain. Full article

The transient receptor potential vanilloid 4 channel (TRPV4) is thought to play a pivotal role in pulmonary arterial circulation. The present study hypothesizes that TRPV4 activation increases nitric oxide (NO) release and activates calcium-activated potassium of intermediate conductance (KCa3.1) in pulmonary arteries. Pulmonary arteries were isolated from wild-type mice (wt) and mice deficient in KCa3.1 channels (Kcnn4^−/−) and mounted for simultaneous NO concentration and relaxation measurements. Human small pulmonary arteries were isolated and mounted in microvascular myographs for isometric tension recordings. Acetylcholine-induced increases in NO and relaxation of pulmonary arteries were slightly decreased in pulmonary arteries from Kcnn4^−/− versus wt mice. An activator of TRPV4 channels, GSK1016790A, increased NO and relaxation to the same degree in pulmonary arteries from wt and Kcnn4^−/− mice. A blocker of TRPV4 channels, HC06704, inhibited increases in NO concentration with no effect on acetylcholine (ACh) relaxation in pulmonary arteries from wt mice, but blocked increases in NO concentration and relaxation in pulmonary arteries from Kcnn4^−/− mice and responses to GSK1016790A in pulmonary arteries from wt and Kcnn4^−/− mice. Concentration-dependent relaxations induced by an inhibitor of sarcoplasmic Ca-ATPase, cyclopiazonic acid, were blocked in the presence of an inhibitor of NO synthase and a blocker of KCa3.1 channels, TRAM-34, in pulmonary arteries from wt mice, but were unaltered in the presence of TRAM-34 in arteries from Kcnn4^−/− mice, or the presence of a blocker of TRPV4 channels. In small human pulmonary arteries, ACh and sodium nitroprusside (SNP) induced concentration-dependent relaxations, blocked by endothelial cell removal, in the presence of an inhibitor of NO synthase and the KCa3.1 channel blocker TRAM-34. GSK1016790A induced relaxation of human pulmonary arteries with endothelium, but failed to relax arteries without endothelium. The findings suggest that TRPV4 channels are involved in endothelium-dependent relaxation and likely regulate pulmonary vascular tone by modulating NO release. Full article

The purpose of this study was to investigate the effect of capsaicin (CAP) on lipid metabolism in weaned piglets and its related mechanisms. Twenty-four weaned piglets with an initial body weight of 9.00 ± 0.30 kg were randomly divided into three groups, with eight replicates in each group. The control (CON) and lipopolysaccharide (LPS) groups were fed a basal diet, while the LPS and capsaicin group (LCA) received the basal diet supplemented with 4 mg/kg pure capsaicin (delivered via 800 mg/kg additive) for 35 days. About 4 h before sampling, piglets in the LPS and LCA groups were intraperitoneally injected with LPS at a dose of 100 μg/kg body weight, while those in the CON group were intraperitoneally injected with the same dose of normal saline. In this study, we found that the addition of 800 mg/kg CAP to the diet of piglets significantly reduced the accumulation of serum triglyceride (TG), non-esterified fatty acids (NEFA), and liver fat, and that CAP up-regulates expression of genes and proteins in the PPARα pathway, consistent with enhanced fatty acid oxidation. The intervention with 4 mg/kg CAP was also found to down-regulate cholesterol synthesis precursors (such as mevalonate, MVA), reduce pro-inflammatory phospholipids (such as phosphatidic acid–phosphatidylcholine, PA–PC), and modulate bile acid metabolism, thereby beneficially regulating blood lipid profiles (TC, TG, LDL-C) and disrupting the “lipid metabolism–inflammation” interaction cycle. Furthermore, CAP promoted fatty acid β-oxidation and bile acid metabolism by activating the TRPV1 channel, which alleviated hepatic lipid accumulation. These findings indicated that CAP has potential application value in improving lipid metabolism, intestinal health, and immune function in weaned piglets. However, its long-term safety and dose-dependent effects require further investigation. Full article

Most transient receptor potential (TRP) channels are Ca²⁺-permeable non-selective cation channels that function as polymodal receptors activated by a wide variety of stimuli, including natural compounds such as pungent substances, physical stimuli, lipids, intracellular signaling molecules, and ions. Their physiological roles are diverse, including sensory perception, ion transport, and intracellular signaling. Similarly, Piezo channels, which are also Ca²⁺-permeable non-selective cation channels, are activated by mechanical stimuli such as membrane stretching and contribute to touch sensation, blood flow regulation, and bladder-filling sensation, among other functions. While research on non-selective cation channels in relation to energy metabolism has primarily focused on TRP channels expressed in primary afferent neurons, studies over the past decade have revealed the important roles of TRP and Piezo channels in brown adipocytes. In this review, we highlight evidence regarding the contributions of TRPV2 and Piezo1 to brown adipocyte differentiation and thermogenesis and briefly summarize recent advances regarding other TRP channels expressed in brown adipocytes. Furthermore, we propose a conceptual framework in which a “modal shift” in TRP/Piezo channels, defined as developmental stage-dependent changes in their functional properties, may contribute to the regulation of brown adipocytes’ functions. Full article

Infrasound, physically defined as sound at frequencies below 20 Hertz, can travel long distances with minimal attenuation and permeate biological tissues due to its marked particle displacement and deep penetration. Generated by both natural phenomena and human-made systems, infrasound has drawn increasing scientific and public attention regarding its potential physiological and psychological effects. Experimental studies demonstrate that infrasound can modulate mechanosensitive structures at the cellular level, particularly pressure-sensitive ion channels such as PIEZO1 and TRPV4, leading to intracellular calcium influx, oxidative stress, altered intercellular communication, and in some settings, apoptosis. These responses vary according to sound pressure levels, frequencies, exposure duration, and tissue type. In the cardiovascular system, higher sound pressures have been associated with mitochondrial injury and fibrosis, whereas low sound pressures may exert context-dependent protective effects. In animal models, prolonged or intense exposure to infrasound has been shown to induce neuroinflammatory responses and memory impairment. Short-term studies in humans at moderate intensities have reported minimal physiological changes, with psychological and contextual factors influencing symptom perception. Occupational environments such as factories and agricultural settings may contain elevated levels of infrasound, underscoring the importance of systematic measurements and exposure assessments. At the same time, controlled infrasound stimulation has shown potential as an adjunct modality in bone repair and tissue regeneration, highlighting its dual capacity as both a biological stressor and a possible therapeutic tool. Overall, existing data indicate that infrasound may be harmful at chronic exposure depending on intensity and frequency, yet beneficial when precisely regulated. Future research should standardize exposure metrics, refine measurement technologies, and clarify dose–response relationships to better define the health risks and therapeutic applications of infrasound. Full article

One of the attractive targets for the relief of stress conditions is TRPV1, which is expressed mostly in primary afferent neurons (nociceptors) and in the central nervous system, mainly in the cortex and hippocampus. We evaluated the action of a potent low-molecular-weight antagonist of TRPV1 (AMG517) and peptide modulator of this channel (APHC3) on long-term potentiation (LTP) and Paired-Pulse Ratio (PPR) in the CA3-CA1 region of the hippocampus of mice. In vivo, we used intranasal administration to provide effective peptide delivery into the brain and analyzed the effects of APHC3 in acute stress tests in comparison with intramuscular administration of APHC3, AMG517, and the reference anxiolytic drug Fabomotizole (Fab). In electrophysiology studies, APHC3 significantly enhanced LTP and PPR, while AMG517 enhanced only PPR. Intranasal administration of APHC3 to mice provided a moderate anxiolytic effect in the single dose (0.01 mg/kg). Intramuscular administration of APHC3 and AMG517 significantly reduced acute stress in mice equal to the reference drug Fab. Thus, TRPV1 modulation in either the peripheral or central nervous system is sufficient to produce an anxiolytic-like effect, likely through distinct underlying mechanisms. Full article

Endothelial ion signaling is crucial for the proper function of the arterial microcirculation, regulating local blood flow to meet metabolic demands and contributing to the regulation of systemic arterial pressure. The role of endothelial ion channels in the precise control of vascular resistance has been primarily investigated in animal models, where the microvasculature is more readily accessible. This review aims to discuss current knowledge on the role of endothelial ion signaling in vasomotor regulation in the human microcirculation, focusing on potassium (K⁺) channels (K_IR2.1, K_ATP, SK_Ca/IK_Ca), Transient Receptor Potential (TRP) channels, particularly TRP Vanilloid 1 (TRPV1) and TRPV4, and Piezo1 channels. The analysis examines the organization of the endothelial ionic signaling machinery in the most extensively studied human microvascular beds, such as the skin, skeletal muscle, and brain, while also discussing vascular reactivity in vessels isolated ex vivo. Accumulating evidence indicates that a distinct repertoire of endothelial ion channels engages diverse endothelium-dependent vasorelaxant pathways across different vascular beds. Understanding how endothelial channels regulate the microvascular unit is predicted to foster the search for alternative therapeutic strategies for treating cardiovascular and neurodegenerative disorders associated with endothelial dysfunction. Full article

Eye drops derived from human blood components (Eye Drops of Human Origin—EDHO) have proven effective in reducing ocular pain associated with severe keratopathies. Among these, Cord Blood Serum (CBS) is particularly promising for its high content of growth and neurotrophic factors. This study evaluated the ability of CBS to modulate inflammatory and nociceptive activation in the human conjunctival epithelial cell (HCEC) line exposed to hyperosmotic stress. CBS batches were characterized for brain-derived neurotrophic factor (BDNF) content and classified as CBS_high (levels > 18.0 ng/mL) or CBS_low (levels < 10.0 ng/mL). HCECs were exposed to NaCl (450 mOsm/L) with or without 5% CBS. Cell viability was evaluated, and the expression of Major Histocompatibility Complex Class II (HLA-DR) (a marker of immune activation) and Transient Receptor Potential Vanilloid 1 (TRPV1) (a nociceptive ion channel responsive to osmotic stress) was assessed via Real Time PCR (RT-PCR). CBS significantly improved HCEC viability under hyperosmotic stress. Exposure to NaCl alone upregulated HLA-DR and TRPV-1 expression. Both CBS preparations attenuated these responses, producing comparable reductions in HLA-DR mRNA and decreasing TRPV-1 expression. Partial reversal of CBS effects by the pan-neurotrophin receptor inhibitor K252a supported neurotrophin involvement. CBS reduces hyperosmolarity-driven inflammation and nociception via HLA-DR and TRPV1 downregulation, supporting its role as a bioactive tear substitute in neuroinflammatory ocular surface disease. Full article

Pathological scars (PSs), which encompass hypertrophic scars (HSs and keloids, pose significant challenges in the realm of plastic surgery due to their characteristics of excessive fibrosis and persistent pruritus. This fibrosis can lead to both functional limitations and aesthetic issues, while pruritus often indicates ongoing scar development and greatly impacts quality of life. Although the underlying cause of both conditions is linked to dysregulated inflammation, the specific connections between fibrosis and pruritus are not well understood. Transient receptor potential channels (TRP), known for their roles in systemic fibrotic diseases and as mediators of chronic pruritus in skin disorders, may play a crucial role in the environment of pathological scars. This review compiles existing research to investigate the idea that certain TRP subfamilies (TRPA1, TRPV1, TRPV3, TRPV4) could link fibrosis and pruritus in pathological scars by interacting with common inflammatory mediators. We suggest that these channels might act as central molecular hubs that connect the signaling pathways of fibrosis and pruritus in these scars. Therefore, targeting TRP channels pharmacologically could be a promising approach to simultaneously alleviate both fibrosis and pruritus, potentially leading to a new dual-pathway treatment strategy for managing pathological scars. Our review also critically examines the current landscape of TRP-targeted therapies, pointing out challenges such as limited selectivity for specific subtypes and the lack of clinical trials focused on pathological scars, while emphasizing the necessity for interdisciplinary advancements in this area. In conclusion, while TRP channels are attractive targets for therapeutic intervention in pathological scars, their effective clinical application necessitates a more profound understanding of the mechanisms specific to scars and the creation of targeted delivery methods. Full article

Capsaicin, a naturally occurring polyphenol, is known to affect energy expenditure and muscle fatigue and modulate contractions in skeletal muscle. The L-type Ca²⁺ channels are known to be an important ion channel involved in the various muscle functions and the effect of capsaicin on the skeletal L-type Ca²⁺ channels is currently unknown. In this study, the effects of capsaicin and capsaicin analogs on depolarization-induced Ca²⁺ effluxes through L-type Ca²⁺ channels in transverse tubule membranes from rabbit skeletal muscle and L-type Ca²⁺ currents recorded using the whole-cell patch clamp technique in rat myotubes were examined. Capsaicin, in the concentration range of 3–100 µM, inhibited depolarization-induced Ca²⁺ effluxes. The effect of capsaicin was not reversed by TRPV1 antagonist SB-366791 (10 µM). While vanilloids (30 µM) including vanillin, vanillyl alcohol, and vanillylamine were ineffective, other capsaicinoids (30 µM) including dihydrocapsaicin, nonivamide, and nordihydrocapsaicin significantly inhibited Ca²⁺ effluxes, suggesting that hydrocarbon chains are required for inhibition. In rat myotubes, capsaicin inhibited L-type Ca²⁺ currents with an IC₅₀ value of 27.2 μM in the presence of SB-366791. Furthermore, in docking studies and molecular dynamic simulations, capsaicinoids with an aliphatic tail showed stronger binding and stable bent conformations in CaV1.1, forming hydrogen bonds with Ser1011 and Thr935 and hydrophobic/π–alkyl contacts with Phe1008, Ile1052, Met1366, and Ala1369, resembling the binding mode of amlodipine. In conclusion, the results indicate that the function of L-type Ca²⁺ channels in mammalian skeletal muscle was inhibited by capsaicin and capsaicin analogs in a TRPV1-independent manner. Full article