Search Results (261)

Transient receptor potential cation channel, subfamily M, member 7 (TRPM7) is a unique protein that functions as both a nonselective cation channel and an alpha kinase (chanzyme). It is ubiquitously expressed across a wide range of tissues and cell types. Through its chanzyme activities, TRPM7 is implicated in many fundamental processes such as intracellular cation homeostasis, cell growth, proliferation, differentiation, and cell cycle progression. Increasing evidence has revealed a crucial role of TRPM7 in regulating immune cell development, activation, and inflammatory responses. This review summarizes recent advances in understanding TRPM7’s structure, function, pharmacology, and roles in innate and adaptive immune cells. In particular, we discuss its impact on immune cells in the central nervous system and its potential implications for neuroinflammatory and neurodegenerative diseases. Full article

Dental pain due to dentine hypersensitivity or pulpitis is characterized by short or lasting episodes of pain triggered by normally innocuous stimuli originating from exposed dentine. Both represent the most frequent pain of the orofacial region. Transient receptor potential (TRP) superfamily of ion channels participates in the detection of different modalities of sensibility in the mammalian sensory teeth system, i.e., trigeminal neurons and odontoblasts. In particular, some members of the melastatin family (TRPM) serve as molecular thermal sensors, and temperature is one of the most potent stimuli in triggering dentine hypersensitivity. Here we review and update the information about the distribution of TRPM channels in the trigeminal ganglion and dental pulp cells, especially odontoblasts, in humans and animal models. In addition to the well-known sensory roles of TRPM, other functions such as the development and mineralization of teeth are considered. Full article

Abdominal aortic aneurysm (AAA) is a life-threatening vascular disease characterized by vascular smooth muscle cell (VSMC) dysfunction and disrupted calcium homeostasis. While transient receptor potential canonical 6 (TRPC6) and transient receptor potential canonical 1 (TRPC1) are known to mediate receptor-operated calcium entry (ROCE) and store-operated calcium entry (SOCE), respectively, the specific contributions of SOCE and ROCE to AAA pathogenesis, and the regulatory interaction between transient receptor potential melastatin 8 (TRPM8) and TRPC1 remain unexplored. In this study, we analyzed human AAA tissues, a papain-induced mouse model, and angiotensin II (Ang II)-treated human aortic smooth muscle cells using histology, wire myography, calcium imaging, and patch-clamp electrophysiology. We observed significant upregulation of TRPM8, TRPC1, and TRPC6 in both human and experimental AAA, with TRPC1 identified as a key mediator of SOCE under pathological conditions. Pharmacological activation of TRPM8 by menthol attenuated TRPC1-mediated SOCE and associated vasoconstriction, effects that were partially reversed by the TRPM8 antagonist A-2. In Ang II-treated cells, TRPM8 activation reduced SOCE and store-operated calcium currents (I_SOCC), effects that were largely abolished by TRPC1 knockdown. These findings suggest that TRPM8 may limit excessive calcium ion (Ca²⁺) influx and vascular remodeling in AAA, pointing to a potential endogenous mechanism to counteract maladaptive calcium signaling in AAA progression. Full article

Nasal hyperreactivity (NHR) is a core symptom of allergic rhinitis (AR) and chronic rhinosinusitis (CRS), frequently induced by cold stimuli. Accumulating evidence indicates that NHR is largely mediated by neuroimmune mechanisms rather than classical allergen-driven inflammation alone. Among the molecular sensors involved, the cold-sensitive transient receptor potential channels transient receptor potential ankyrin 1 (TRPA1) and transient receptor potential melastatin 8 (TRPM8) have emerged as key regulators linking environmental cold exposure to sensory nerve activation, neuropeptide release, and immune modulation. This review systematically summarizes the expression, functions, and neuroimmune mechanisms mediated by TRPA1 and TRPM8 in AR and CRS, with a particular focus on their roles in NHR. Furthermore, it discusses the therapeutic potential of targeting these channels to alleviate neurogenic inflammation and refractory nasal symptoms, aiming to provide new perspectives for understanding disease mechanisms and developing precise treatments. Full article

The human corneal endothelium (HCE) is critical for maintaining corneal transparency. Dysfunctions due to cell loss are linked to altered intracellular calcium ([Ca²⁺]_i) homeostasis. Transient receptor potential channels (TRPs) are key regulators of [Ca²⁺]_i, and both L-ascorbic acid (Asc) and cannabinoid receptor (CB) agonists have been implicated in modulating TRP activity. This study investigated the effects of 1 mM Asc and the CB agonist WIN 55,212-2 (WIN) (10 µM) on [Ca²⁺]_i regulation in human corneal endothelial cells (HCECs). HCEC-12 was used as the established HCE cell model. [Ca²⁺]_i dynamics were assessed by fura-2/AM fluorescence imaging, and membrane currents were analyzed using planar patch-clamp recordings. Adding 1 mM Asc increased [Ca²⁺]_i, which was partially suppressed by the TRPV1 blocker AMG-9810 (AMG) (20 µM) and the TRPV4 blocker GSK2193874 (GSK219) (10 µM). Furthermore, 1 mM Asc increased whole-cell currents. WIN also induced [Ca²⁺]_i transients that were partially attenuated by AMG, the TRPM8 blocker AMTB (20 µM), GSK219, and the CB1 inverse agonist AM251 (10 µM). In addition, combined treatment with Asc and WIN enhanced [Ca²⁺]_i elevations compared with either treatment alone. These findings provide the first evidence for a functional interaction between TRP channel activity and CB signaling in HCECs. The inhibitory effect of AM251 suggests a predominant contribution of CB1 receptors. Given the central role of Ca²⁺ homeostasis in corneal endothelial function and disease, these results may contribute to a better understanding of endothelial pathophysiology and support further investigation of TRPs and cannabinoid signaling as potential targets in corneal 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

This study presents the successful expression, purification, and functional characterization of the human TRPM8 ion channel, a key player in temperature sensing and pain modulation. Using a modified bacterial expression protocol and DDM-based solubilization, TRPM8 was purified via HPLC-SEC and analyzed for its membrane-binding properties. FRET-based assays with synthetic lipid rafts revealed a strong and selective affinity of TRPM8 for cholesterol-containing membranes, suggesting cholesterol’s role in modulating TRPM8 localization and activity. These findings provide quantitative in vitro evidence of TRPM8–cholesterol interactions and establish a robust model system for future structural and functional studies of membrane-associated proteins. Full article

Gitelman syndrome (GS) is a rare, autosomal recessive salt-losing tubulopathy caused by mutations in the SLC12A3 gene. It involves dysfunction of the sodium-chloride cotransporter positioned on the apical membranes of the distal convoluted tubule cells, causing sodium shortage and mimicking the use of thiazide diuretics. Hyperaldosteronism secondary to sodium depletion and hypovolemia causes hypokalaemia and metabolic alkalosis. This is associated with inhibition of the Transient Receptor Potential Cation Channel, Subfamily M, Member 6 –TRPM6 channel, which leads to urinary magnesium leakage and hypomagnesemia, subsequently stopping PTH secretion and resulting in hypocalcemia and hypocalciuria. Gitelman syndrome frequently presents later in life, as the symptoms are usually not very threatening. However, early identification, diagnosis, and urgent intervention are essential to improve patient prognosis and quality of life. Importantly, both hypomagnesemia and hypokalaemia can impair insulin secretion and sensitivity. Furthermore, hyperaldosteronism caused by the secondary activation of the R-A-A system can also lead to these disorders. Glucose metabolism problems have been shown to prevail amongst GS patients and manifest more frequently in comparison to the general population. When it comes to the treatment used to reduce hyperglycemia in GS-related T2DM, we consider which of the available drugs are the best for those patients. The article analyses the association of Gitelman syndrome with diabetes mellitus based on the available medical literature—as there are no clinical trials or meta-analyses available for this group, it is presented as a narrative review. Full article

Cisplatin (CSP) is a first-line chemotherapeutic for laryngeal squamous cell carcinoma (LSCC), but its clinical effectiveness is limited by resistance and toxicity. Hesperidin (HESP), a citrus flavonoid, may enhance chemotherapeutic efficacy through pro-apoptotic properties. This study investigated the involvement of the transient receptor potential melastatin-2 (TRPM2) channel in the HESP-mediated potentiation of CSP-induced cytotoxicity in human laryngeal carcinoma (Hep-2) cells. Hep-2 cells were treated with CSP (25 µM), HESP (25 µM), or their combination for 24 h. The findings showed that the combined application of HESP and CSP reduced cell viability by approximately 50% (p < 0.001), which was the lowest compared to CSP alone. Western blot analysis revealed that TRPM2 protein expression was higher in the CSP+HESP group compared to the control group (p < 0.001). This synergistic treatment resulted in an increase in ROS production and a decrease in MDA levels, accompanied by a reduction in cellular GSH levels (p < 0.001). Furthermore, the combination therapy increased pro-inflammatory cytokines such as IL-1β and TNF-α (p < 0.001). Functional analyses showed that HESP treatment enhanced CSP-induced Ca²⁺ influx and altered mitochondrial membrane potential (p < 0.001). The pharmacological inhibition of TRPM2 with ACA and 2-APB reversed these effects, restoring redox balance and reducing cellular damage. In conclusion, HESP amplifies CSP-induced apoptosis in Hep-2 cells through TRPM2-dependent oxidative stress, Ca²⁺ dysregulation, and mitochondrial dysfunction. These findings identify TRPM2 as a mechanistic mediator of HESP-enhanced chemosensitivity in LSCC. Full article

Background/Objectives: Magnesium (Mg²⁺) supplements can contain different types of Mg²⁺ salts, which influence their bioavailability. A highly bioavailable and bioaccessible Mg²⁺ source is essential to meet requirements for many physiological processes that are fundamental to human health. The objective of this study was to compare the bioavailability of Mg²⁺ from different sources, with different composition and chemical structure, namely, Aquamin Mg Soluble (seawater), magnesium oxide, commercial magnesium bisglycinate 1, and analytical grade magnesium bisglycinate 2. In addition, the influence of the different Mg²⁺ sources on transported Mg²⁺ and expression of TRPM6 and TRPM7 genes in Caco-2 cell monolayers was also evaluated to estimate bioavailability. TRPM6 and TRPM7 are members of the transient receptor potential melastatin subfamily characterized as Mg²⁺ permeable channels. Method: The study involved analyzing bioavailability of the Mg²⁺ sources predigested with and without food using the Infogest model prior to application to a Caco-2 cell monolayer in transwells for assessing transport. Mg²⁺ concentration on the basolateral side was analyzed by ICP-MS, and expression of TRPM6 and TRPM7 genes in the monolayer was analyzed using real-time qPCR. Results: Aquamin Mg Soluble showed significantly higher bioavailability compared to magnesium bisglycinate 2 (p = 0.016) when digested with food prior to application to the Caco-2 monolayer. In the digestion without food prior to the Caco-2 monolayer, there was no significant difference between Mg²⁺ bioavailability among the tested supplements. The TRPM6 gene was significantly downregulated in Caco-2 monolayers exposed to Aquamin Mg Soluble compared to untreated Caco-2 cells (p < 0.001). Conclusions: The INFOGEST digestion model showed that Aquamin Mg Soluble provides a highly bioavailable form of Mg²⁺, while the Caco-2 monolayer model also demonstrated its increased bioavailability by the modulation of TRPM6 gene expression. Full article

Dysregulated magnesium (Mg²⁺) homeostasis contributes to colorectal cancer (CRC), yet its context-dependent function within the tumor microenvironment remains unresolved. This study aimed to determine how sustained low and high extracellular Mg²⁺ environments affect CRC spheroid (SP) growth and Mg²⁺ homeostasis using HT-29 SPs. We analyzed Mg²⁺ flux, the expression of Mg²⁺ transporters (e.g., Transient Receptor Potential Melastatin (TRPM) 6), viability, apoptotic and autophagic markers, and phospho-/oxidoproteomic alterations. Both Mg²⁺ extremes destabilized SP architecture, reduced viability, and induced apoptosis and autophagy, with SPs displaying heightened vulnerability relative to 2D cultures. Mg²⁺ stress impaired Mg²⁺ influx and eliminated adaptive transporter regulation in SPs. Loss of membrane TRPM6/7 heterodimers, driven by altered phosphorylation (e.g., TRPM6 Serine 141, Serine 1252, Threonine 1851) and elevated oxidation (e.g., Methionine 1755), suppressed channel activity. High Mg²⁺ caused profound metabolic failure despite increased total Mg²⁺, reflecting functional Mg²⁺ deficiency. CRC spheroids are acutely susceptible to Mg²⁺ imbalance due to collapsed transporter homeostasis and post-translational inhibition of Mg²⁺ channels. These findings reveal a targetable metabolic vulnerability and support the therapeutic potential of localized Mg²⁺ modulation in CRC. Full article

Background: Oxytocin (OT) is a nonapeptide hormone produced in the hypothalamus, released into the brain and peripheral circulation, and plays a key role in social behavior. Recent studies indicate that complement component C4a is an OT-binding protein, which modulates plasma OT concentrations in mice. However, the role of C4a is unclear as to whether it contributes to consolation behavior. Methods: Social behavior, especially allogrooming, which is a form of empathy that depends on detecting the emotional states of others, was measured in wild-type or C4a/Slp knockout (Slp^−/−) male mice. Results: Observer mice of both genotypes exhibited comforting (allogrooming) behavior toward a cage-mate demonstrator during reunion after brief isolation of the demonstrator mice. When demonstrator mice experienced body restraint stress during isolation, the allogrooming behavior was significantly increased in both genotypes, with a markedly greater increase in Slp^−/− than in Slp^+/+ mice. Allogrooming behavior in observer Slp^−/− mice was significantly suppressed by an OT receptor antagonist. Furthermore, immunohistochemical analysis revealed that activation was significantly elevated in OT-positive hypothalamic neurons in observer Slp^−/− mice that interacted with stressed demonstrator mice. OT release from the isolated hypothalamus, stimulated via CD38 and TRPM2 channel activation, was greater in Slp^−/− mice than in Slp^+/+ mice. Conclusions: Our results highlight that the data are consistent with a potential role for C4a in modulating neural circuits, possibly via its peripheral action on OT bioavailability. Direct evidence for C4a’s action within the brain remains a hypothesis for future investigation, for example, via site-specific manipulations. Full article

Mutual interaction between the nervous and immune systems underpins many pathophysiological processes. Transient Receptor Potential Melastatin 2 (TRPM2) channels are abundantly expressed in both systems, acting as a critical interface of neuroimmune interaction. TRPM2 channels in immune cells participate in innate immunity and immune inflammation by acting as an oxidative stress and metabolic sensor. TRPM2 in neurons functions not only as an oxidative sensor but also a temperature sensor and a pain transducer critical to neuronal death, temperature sensing, thermoregulation, and chronic pain. Cooperation between immune and neuronal TRPM2 influences the outcome of neuroimmune interaction and many diseases such as infection, inflammation, ischemic stroke, pain, and neurodegenerative diseases. Improved understanding of neuronal and immune TRPM2 interaction is essential for therapeutic interventions for the treatment of diseases mediated by TRPM2 channels. Full article

This study evaluated the protective effects of naringin (NG) against intestinal injury in 7-day-old piglets infected with porcine epidemic diarrhea virus (PEDV). Eighteen piglets (Duroc × Landrace × Large, body weight = 2.58 ± 0.05 kg) were divided into three treatment groups based on similar body weights and equal numbers of males and females: the blank control group (CON group), the PEDV infection group (PEDV group), and the NG intervention + PEDV infection group (NG + PEDV group) (n = 6 per group). The experiment lasted for 11 days, comprising a pre-feeding period from days 0 to 3 and a formal experimental period from days 4 to 10. On days 4–10 of the experiment, piglets in the NG + PEDV group were orally administered NG (10 mg/kg). On Day 8 of the experiment, piglets in the PEDV and NG + PEDV groups were inoculated with PEDV (3 mL, 10⁶ 50% tissue culture infective dose (TCID₅₀) per milliliter). On day 11 of the experiment, piglets were euthanized for sample collection. PEDV infection caused significant intestinal damage, including a decreased (p < 0.05) villus height in the duodenum and ileum and an increased (p < 0.05) crypt depth in all intestinal segments. This intestinal damage was accompanied by an impaired absorptive function, as indicated by reduced (p < 0.05) serum D-xylose. Further results showed that PEDV compromised the intestinal antioxidant capacity by decreasing (p < 0.05) glutathione peroxidase and catalase activities, and it stimulated the intestinal inflammatory response by upregulating (p < 0.05) the expression of key inflammatory genes, including regenerating family member 3 gamma (REG3G; duodenum, jejunum, colon), S100 calcium binding protein A9 (S100A9; ileum, colon), interleukin 1 beta (IL-1β; ileum, colon), and S100 calcium binding protein A8 (S100A8; colon). PEDV also suppressed the intestinal lipid metabolism pathway by downregulating (p < 0.05) the ileal expression of Solute Carrier Family 27 Member 4 (SLC27A4), Microsomal Triglyceride Transfer Protein (MTTP), Apolipoprotein A4 (APOA4), Apolipoprotein C3 (APOC3), Diacylglycerol O-Acyltransferase 1 (DGAT1), and Cytochrome P450 Family 2 Subfamily J Member 34 (CYP2J34). Moreover, PEDV suppressed the intestinal antiviral ability by downregulating (p < 0.05) interferon (IFN) signaling pathway genes, including MX dynamin like GTPase 1 (MX1) and ISG15 ubiquitin like modifier (ISG15) in the duodenum; weakened intestinal water and ion transport by downregulating (p < 0.05) aquaporin 10 (AQP10) and potassium inwardly rectifying channel subfamily J member 13 (KCNJ13) in the duodenum, aquaporin 7 (AQP7) and transient receptor potential cation channel subfamily V member 6 (TRPV6) in the ileum, and TRPV6 and transient receptor potential cation channel subfamily M member 6 (TRPM6) in the colon; and inhibited intestinal digestive and absorptive function by downregulating (p < 0.05) phosphoenolpyruvate carboxykinase 1 (PCK1) in the duodenum and sucrase-isomaltase (SI) in the ileum. Notably, NG effectively counteracted these detrimental effects. Moreover, NG activated the IFN signaling pathway in the jejunum and suppressed PEDV replication in the colon. In conclusion, NG alleviates PEDV-induced intestinal injury by enhancing the antioxidant capacity, suppressing inflammation, normalizing the expression of metabolic and transport genes, and improving the antiviral ability. Full article

Dental pain often arises from the compromised integrity of the tooth pulp due to dental injury or caries. The dentin–pulp complex has long been considered to be central to the unique biology of dental pain. Most trigeminal ganglion afferents projecting into tooth pulp are myelinated neurons, which lose their myelination at the site of peripheral dentin innervation. The pulpal afferents likely combine multiple internal and external stimuli to mediate nociception and maintain pulp homeostasis. Transient receptor potential (TRP) ion channels in neurons and odontoblasts, along with mechanosensitive ion channels such as Piezo, form a key molecular hub for pulpal nociception by sensing thermal, chemical, and hydrodynamic stimuli. Among these, TRP vanilloid 1 (TRPV1) mediates nociception and the release of calcitonin-gene-related peptides (CGRPs), while TRP canonical 5 (TRPC5) mediates cold pain. TRP melastatin 8 (TRPM8) mediates the transduction of hyperosmotic stimuli. Pulpitis elevates endogenous TRPV1 and TRPA1 agonists, while inflammatory mediators sensitize TRP channels, amplifying pain. CGRP recruits immune cells and promotes bacterial clearance and reparative dentinogenesis, yet the roles of TRP channels in these processes remain unclear. Future studies should use advanced multi-omics and in vivo or organotypic models in animal and human teeth to define TRP channel contributions to pain, immune responses, and regeneration. Understanding neuronal and non-neuronal TRP channel interactions and their integration with other ion channels may enable novel analgesic and regenerative strategies in dentistry. Full article