TRPV1 Channels Research Articles

Novel 3-D Macrophage Spheroid Model Reveals Reciprocal Regulation of Immunomechanical Stress and Mechano-Immunological Response

Abstract Purpose In many diseases, an overabundance of macrophages contributes to adverse outcomes. While numerous studies have compared macrophage phenotype after mechanical stimulation or with varying local stiffness, it is unclear if and how macrophages directly contribute to mechanical forces in their microenvironment. Methods Raw 264.7 murine macrophages were embedded in a confining agarose gel, and proliferated to form spheroids over days/weeks. Gels were synthesized at various concentrations to tune stiffness and were shown to support cell viability and spheroid growth. These cell-agarose constructs were treated with media supplements to promote macrophage polarization. Spheroid geometries were used to computationally model the strain generated in the agarose by macrophage spheroid growth. Agarose-embedded macrophages were analyzed for viability, spheroid size, stress generation, and gene expression. Results Macrophages form spheroids and generate growth-induced mechanical forces (i.e., solid stress) within confining agarose gels, which can be maintained for at least 16 days in culture. Increasing agarose concentration increases gel stiffness, restricts spheroid expansion, limits gel deformation, and causes a decrease in Ki67 expression. Lipopolysaccharide (LPS) stimulation increases spheroid growth, though this effect is reversed with the addition of IFNγ. The mechanosensitive ion channels Piezo1 and TRPV4 have reduced expression with increased stiffness, externally applied compression, LPS stimulation, and M1-like polarization. Conclusions Macrophages alone both respond to and generate solid stress. Understanding how macrophage generation of growth-induced solid stress responds to different environmental conditions will help to inform treatment strategies for the plethora of diseases that involve macrophage accumulation and inflammation.

Capsaicin attenuates the effect of inflammatory cytokines in a HaCaT cell model for basal keratinocytes.

The resolution of the skin's inflammatory response is only possible if its barrier function is restored. TRPV1 channel activation plays an important role during inflammation but the effect of this activation on the skin barrier under inflammatory conditions has not been clarified. We hypothesize that it could potentially aid the keratinocyte barrier by reducing inflammatory cytokine release and promoting tight junction development. To explore the role of TRPV1 activation in inflammation, we designed and optimized an in vitro model of keratinocytes with basal epidermal layer characteristics using HaCaT cells and TNFα to induce inflammation. TNFα increased the gene expression of tight junction protein claudin 1 (CLDN1) by at least 2.60 ± 0.16-fold, in a concentration-dependent manner, over a 48h period. The administration of a capsaicin pre-treatment reduced the CLDN1 expression to 1.51 ± 0.16-fold during the first 6h after TNFα induction, whereas IL-8 cytokine release was reduced 0.64 ± 0.17-fold. After 48h, CLDN1 protein levels increased by a factor of 6.57 ± 1.39 compared to cells only treated with TNFα. These results suggest that activation of TRPV1 by capsaicin can potentiate the increase in CLDN1 expression and CLDN1 protein synthesis induced by TNFα in cultured keratinocytes, while reducing the release of IL-8.

Investigation of local stimulation effects of embedding PGLA at Zusanli (ST36) acupoint in rats based on TRPV2 and TRPV4 ion channels.

Acupoint Catgut Embedding (ACE) is an extended and developed form of traditional acupuncture that serves as a composite stimulation therapy for various diseases. However, its local stimulation effects on acupoints remain unclear. Acupuncture can activate mechanically sensitive calcium ion channels, TRPV2 and TRPV4, located on various cell membranes, promoting Ca2+ influx in acupoint tissues to exert effects. Whether ACE can form mechanical physical stimulation to regulate these channels and the related linkage effect requires validation. This study investigates the influence of TRPV2 and TRPV4 ion channels on the local stimulation effects of ACE by embedding PGLA suture at the Zusanli (ST36) acupoint in rats and using TRPV2 and TRPV4 inhibitors. Flow cytometry, immunofluorescence, Western blot, and Real-time quantitative PCR were employed to detect intracellular Ca2+ fluorescence intensity, the expression of macrophage (Mac) CD68 and mast cell (MC) tryptase, as well as the protein and mRNA expression of TRPV2 and TRPV4 in acupoint tissues after PGLA embedding. The results indicate that ACE using PGLA suture significantly increases the mRNA and protein expression of TRPV2 and TRPV4, Ca2+ fluorescence intensity, and the expression of Mac CD68 and MC tryptase in acupoint tissues, with these effects diminishing over time. The increasing trends are reduced after using inhibitors, particularly when both inhibitors are used simultaneously. Furthermore, correlation analysis shows that embedding PGLA suture at the ST36 acupoint regulates Mac and MC functions through Ca2+ signaling involving not only TRPV2 and TRPV4 but multiple pathways. These results suggest that embedding PGLA suture at the ST36 acupoint generates mechanical physical stimulation and regulates TRPV2 and TRPV4 ion channels, which couple with Ca2+ signaling to form a linkage effect that gradually weakens over time. This provides new reference data for further studies on the stimulation effects and clinical promotion of ACE.

Altered Expression of Thyroid- and Calcium Ion Channels-Related Genes in Rat Testes by Short-Term Exposure to Commercial Herbicides Paraquat or 2,4-D.

Exposure to pesticides such as paraquat and 2,4-dichlorophenoxyacetic acid (2,4-D) has been linked to harmful health effects, including alterations in male reproduction. Both herbicides are widely used in developing countries and have been associated with reproductive alterations, such as disruption of spermatogenesis and steroidogenesis. The thyroid axis and Ca2+-permeable ion channels play a key role in these processes, and their disruption can lead to reproductive issues and even infertility. This study evaluated the short-term effects of exposure to commercial herbicides based on paraquat and 2,4-D on gene expression in rat testes. At the molecular level, exposure to paraquat increased the expression of the thyroid hormone transporters monocarboxylate transporter 8 (Mct8) and organic anion-transporting polypeptide 1C1 (Oatp1c1) and the thyroid receptor alpha (TRα), suggesting a possible endocrine disruption. However, it did not alter the expression of the sperm-associated cation channels (CatSper1-2) or vanilloid receptor-related osmotically activated channel (Trpv4) related to sperm motility. In contrast, exposure to 2,4-D reduced the expression of the Mct10 transporter, Dio2 deiodinase, and CatSper1, which could affect both the availability of T3 in testicular cells and sperm quality, consistent with previous studies. However, 2,4-D did not affect the expression of CatSper2 or Trpv4. Deregulation of gene expression could explain the alterations in male reproductive processes reported by exposure to paraquat and 2,4-D. These thyroid hormone-related genes can serve as molecular biomarkers to assess endocrine disruption due to exposure to these herbicides, aiding in evaluating the health risks of pesticides.

Unraveling TRPV1's Role in Cancer: Expression, Modulation, and Therapeutic Opportunities with Capsaicin.

Cancer is a global health challenge with rising incidence and mortality rates, posing significant concerns. The World Health Organization reports cancer as a leading cause of death worldwide, contributing to nearly one in six deaths. Cancer pathogenesis involves disruptions in cellular signaling pathways, resulting in uncontrolled cell growth and metastasis. Among emerging players in cancer biology, Transient Receptor Potential (TRP) channels, notably TRPV1, have garnered attention due to their altered expression in cancer cells and roles in tumorigenesis and progression. TRPV1, also known as the capsaicin receptor, is pivotal in cancer cell death and pain mediation, offering promise as a therapeutic target. Activation of TRPV1 triggers calcium influx and affects cell signaling linked to growth and death. Additionally, TRPV1 is implicated in cancer-induced pain and chemo-sensitivity, with upregulation observed in sensory neurons innervating oral cancers. Also, when capsaicin, a compound from chili peppers, interacts with TRPV1, it elicits a "hot" sensation and influences cancer processes through calcium influx. Understanding TRPV1's multifaceted roles in cancer may lead to novel therapeutic strategies for managing cancer-related symptoms and improving patient outcomes. The current review elucidates the comprehensive role of capsaicin in cancer therapy, particularly through the TRPV1 channel, highlighting its effects in various cells via different signaling pathways and discussing its limitations.

Sex differences in the orofacial antinociceptive effect of metformin and the role of transient receptor potential channels.

Metformin is classified as a biguanide and is used in the treatment of type 2 diabetes. It is used worldwide and has been investigated in drug repositioning. The present study aims to investigate whether there is sexual dimorphism in the orofacial antinociceptive effect of metformin and the participation of TRP channels. Acute nociceptive behavior was induced by administering cinnamaldehyde or capsaicin to the upper lip. Nociceptive behavior was assessed through orofacial rubbing, and the effects of pre-treatment with metformin (125 or 250mg/Kg) or vehicle (control) were tested on the behavior. Nociceptive behavior was also induced by formalin injected into the temporomandibular joint. The chronic pain model involved infraorbital nerve transection (IONX) was evaluated using Von Frey electronic filaments. Trpv1 gene expression was analyzed in the nerve ganglion. Docking experiments were performed. Metformin, but not the vehicle, produced antinociception (p < 0.0001) in all acute nociceptive behaviors in both sexes, and these effects were attenuated by the TRPV1 antagonist capsazepine and the TRPA1 antagonist HC-030031. In IONX with better (**p < 0.01, ****p < 0.0001 vs. control) results in females. TRPV1 gene expression was observed in the metformin treated group (*p < 0.05 vs. control). Docking experiments revealed that metformin may interact with TRPV1 and TRPA1 channels. Metformin promotes orofacial antinociception in both sexes in acute pain and is more effective in chronic pain in females than in males, through the modulation of TRPV1 and TRPA1 channels. These preclinical findings suggest a potential repositioning of metformin as an analgesic agent in acute and chronic orofacial pain states.

Investigation of the anti-inflammatory, anti-pruritic, and analgesic effects of sophocarpine inhibiting TRP channels in a mouse model of inflammatory itch and pain

Ethnopharmacological relevanceSophocarpine is a bioactive compound extracted from the dried root of Sophorae Flavesentis Aiton, a plant that has been used for thousands of years for various conditions including skin itch and pain. Its antipruritic and analgesic effects are suggested in publications, while the molecular mechanisms underneath interacting with TRP channels are not understood. Aim of the studyWe investigated the anti-inflammatory, antipruritic, and analgesic effects of sophocarpine in a murine inflammatory itch and pain model to elucidate the underlying mechanisms. Materials and methodsWe evaluated sophocarpine's anti-pruritic and analgesic effects by monitoring mice's scratching and wiping behaviors, and the anti-inflammatory effect by measuring psoriasis area and severity index (PASI) score. The mRNA and protein expression of TRPA1/TRPV1 was analyzed by real-time quantitative polymerase chain reaction and western blotting. We further investigated the relationship between sophocarpine and TRPA1/TRPV1 in mice administered allyl-isothiocyanate (AITC) or capsaicin and by molecular docking. ResultsWe found that sophocarpine decreased scratching bouts, wipes, and the PASI score, reduced the TNF-α and IL-1β in the skin and TRPA1 and TRPV1 in the trigeminal ganglion. Pretreatment of sophocarpine decreased AITC-induced scratching bouts and wipes and capsaicin-induced wipes. We also found potential competitive bindings between sophocarpine and AITC/capsaicin to TRPA1/TRPV1. ConclusionsSophocarpine is a potential competitive inhibitor of TRPA1 and TRPV1 channels eliciting strong anti-inflammatory, anti-pruritic, and analgesic effects, suggesting its significant therapeutic potential in treating diseases with inflammatory itch and pain.

Uncaria Rhynchophylla and hirsuteine as TRPV1 agonists inducing channel desensitization

Ethnopharmacological relevanceUncaria rhynchophylla (UR) is recognized for its therapeutic applications in treating hypertension and inflammation. However, the specific molecular mechanisms how UR and its bioactive constituents modulate inflammatory pathways remain unknown. This study investigates the effects of UR extract and its constituent, hirsuteine (HST), on TRPV1 channel modulation which is related to hypertension and inflammation. Materials and methodsElectrophysiological recordings and calcium imaging experiments were conducted to assess TRPV1 activation by UR extract and HST in HEK293T cells and sensory neurons. ResultsUR extract and HST activated TRPV1 in HEK293T cells, with repeated applications causing channel desensitization. HST application on TRPV1-positive sensory neurons significantly reduced electrical activity compared to capsaicin. ConclusionThis study demonstrated UR extract and HST are a novel TRPV1 agonists inducing channel desensitization and a potent agent for treatment of TRPV1 dependent pain relief.

Infrared neuroglial modulation of spinal locomotor networks

Infrared neural stimulation (INS) emerges as a promising tool for stimulating the nervous system by its high spatial precision and absence of the use of exogenous agents into the tissue, which led to the first successful proof of concept in human brain. While neural networks have been the focal point of INS research, this technique is also non cell type specific as it triggers activity in non electrically excitable cells. Despite increasing interest, there remains to demonstrate well defined simultaneous astrocytic and neuronal signals in response to INS. Using calcium imaging, we show that INS has the capacity to initiate calcium signaling in both astrocytes and neurons simultaneously from the rostral lumbar spinal cord, each exhibiting distinct temporal and amplitude characteristics. Importantly, the mechanism underlying infrared-induced neuronal and astrocytic calcium signaling differ, with neuronal activity relying on sodium channels, whereas induced astrocytic signaling is predominantly influenced by extracellular calcium and TRPV4 channels. Furthermore, our findings demonstrate the frequency shift of neuronal calcium oscillations through infrared stimulation. By deepening our understanding in INS fundamentals, this technique holds great promise for advancing neuroscience, deepening our understanding of pathologies, and potentially paving the way for future clinical applications.

Tubulin interaction at tubulin-binding sequence 1 (TBS1) is required for proper surface expression and TRPV1 channel activity

TRPV1, a polymodal and nonselective cation channel has unique gating mechanisms which is regulated by supramolecular complexes at the plasma membrane formed with membrane proteins, lipids and kinase pathways. Crosstalk between microtubule cytoskeleton with TRPV1 at various level has been established. Previously we demonstrated that the positively-charged residues present at specific tubulin-binding stretch sequences (i.e. TBS1 and TBS2, AA 710–730 and 770–797 respectively) located at the C-terminus of TRPV1 are crucial for tubulin interaction and such sequences have evolutionary origin. The nature of TRPV1-tubulin complex and its functional importance remain poorly understood. Here, we made several mutations in the TBS1 and TBS2 regions and characterized such mutants. Though these mutations reduce tubulin interaction drastically, a low and basal-level of tubulin interaction remains with these mutants. Substitution of positively-charged residues (Lys and Arg) to Ala in the TBS1, but not in TBS2 region results in reduced ligand-sensitivity. Such ligand-sensitivity is altered in response to Taxol or Nocodazole. We suggest that tubulin interaction at the TBS1 region favours channel opening while interaction in TBS2 favours channel closure. We demonstrate for the first time the functional significance of TRPV1-tubulin complex and endorse microtubule dynamics as a parameter that can alter TRPV1 channel functions. These findings can be relevant for several physiological functions and also in the context of chemotherapy-induced neuropathic pain caused by various microtubule stabilizing chemotherapeutic drugs. Thus, this characterization may indicate TRPV1 as a potential therapeutic target relevant for chemotherapeutic drug-induced peripheral neuropathies, neurodegeneration and other neurological disorders.

Signaling Paradigms of H2S-Induced Vasodilation: A Comprehensive Review.

Hydrogen sulfide (H2S), a gas traditionally considered toxic, is now recognized as a vital endogenous signaling molecule with a complex physiology. This comprehensive study encompasses a systematic literature review that explores the intricate mechanisms underlying H2S-induced vasodilation. The vasodilatory effects of H2S are primarily mediated by activating ATP-sensitive potassium (K_ATP) channels, leading to membrane hyperpolarization and subsequent relaxation of vascular smooth muscle cells (VSMCs). Additionally, H2S inhibits L-type calcium channels, reducing calcium influx and diminishing VSMC contraction. Beyond ion channel modulation, H2S profoundly impacts cyclic nucleotide signaling pathways. It stimulates soluble guanylyl cyclase (sGC), increasing the production of cyclic guanosine monophosphate (cGMP). Elevated cGMP levels activate protein kinase G (PKG), which phosphorylates downstream targets like vasodilator-stimulated phosphoprotein (VASP) and promotes smooth muscle relaxation. The synergy between H2S and nitric oxide (NO) signaling further amplifies vasodilation. H2S enhances NO bioavailability by inhibiting its degradation and stimulating endothelial nitric oxide synthase (eNOS) activity, increasing cGMP levels and potent vasodilatory responses. Protein sulfhydration, a post-translational modification, plays a crucial role in cell signaling. H2S S-sulfurates oxidized cysteine residues, while polysulfides (H2Sn) are responsible for S-sulfurating reduced cysteine residues. Sulfhydration of key proteins like K_ATP channels and sGC enhances their activity, contributing to the overall vasodilatory effect. Furthermore, H2S interaction with endothelium-derived hyperpolarizing factor (EDHF) pathways adds another layer to its vasodilatory mechanism. By enhancing EDHF activity, H2S facilitates the hyperpolarization and relaxation of VSMCs through gap junctions between endothelial cells and VSMCs. Recent findings suggest that H2S can also modulate transient receptor potential (TRP) channels, particularly TRPV4 channels, in endothelial cells. Activating these channels by H2S promotes calcium entry, stimulating the production of vasodilatory agents like NO and prostacyclin, thereby regulating vascular tone. The comprehensive understanding of H2S-induced vasodilation mechanisms highlights its therapeutic potential. The multifaceted approach of H2S in modulating vascular tone presents a promising strategy for developing novel treatments for hypertension, ischemic conditions, and other vascular disorders. The interaction of H2S with ion channels, cyclic nucleotide signaling, NO pathways, ROS (Reactive Oxygen Species) scavenging, protein sulfhydration, and EDHF underscores its complexity and therapeutic relevance. In conclusion, the intricate signaling paradigms of H2S-induced vasodilation offer valuable insights into its physiological role and therapeutic potential, promising innovative approaches for managing various vascular diseases through the modulation of vascular tone.

NIR Laser Irradiation Promotes Osteogenic Differentiation of PDLSCs Through the Activation of TRPV1 Channels and Subsequent Calcium Signaling.

Near-infrared (NIR) irradiation has shown potential to stimulate osteogenic differentiation, but the mechanisms are not fully understood. The study is to investigate the effects of NIR laser irradiation on osteoblastic differentiation. Human periodontal ligament stem cells (hPDLSCs) were cultured in osteogenic medium and exposed to 810 nm NIR laser at 0.5 J/cm2 every 48 h. The transient receptor potential vanilloid (TRPV1) channel inhibitor capsazepine (CPZ) was used to evaluate the role of calcium influx. Osteogenic differentiation was assessed by proliferation (CCK-8), alkaline phosphatase (ALP) activity, mineralization (Alizarin Red), and expression of bone markers by PCR and Western blot over 2 weeks. Intracellular calcium was measured by Fluo-4M dye and flow cytometry. Results showed that NIR irradiation enhanced hPDLSC proliferation, ALP activity, mineralization, and bone marker expression, indicating increased osteogenic differentiation. These effects were inhibited by CPZ. NIR induced a transient rise in intracellular calcium peaking at 3 min, which was blocked by CPZ. In conclusion, this study demonstrates that NIR laser irradiation promotes osteogenic differentiation of PDLSCs through the activation of TRPV1 channels and subsequent calcium signaling. Further research is warranted to optimize the treatment parameters and elucidate the detailed signaling pathways involved, paving the way for the clinical application of NIR therapy in the treatment of bone disorders and periodontal disease.

TRPV1-targeted ion-responsive hydrogel against pyroptosis of dry eye disease

Dry eye disease (DED) is a complex ocular surface abnormality characterized by tear film hyperosmolarity, inflammation, and damage. Left untreated, DED can lead to a self-perpetuating vicious cycle of worsening symptoms. Existing treatments for DED face challenges related to limited drug delivery to the ocular surface and potential side effects from nonspecific drug targeting. In an effort to address these issues, we developed a novel ion-responsive in situ gelling system targeting the transient receptor potential vanilloid 1 (TRPV1), based on co-assembly of the hydrogelator KFQ12 with the functional peptide V1-Cal. The KFQ12/V1-Cal (KVC) aqueous solution, when dripped and mixed with the ionic tear film on the ocular surface, rapidly transformed into a honeycomb-like hydrogel. This hydrogel exhibited prolonged retention on the ocular surface, serving as a stable scaffold for corneal epithelium regeneration and providing protection against external pathogens while maintaining gas exchange. In a murine model of DED, the KVC hydrogel demonstrated superior therapeutic efficacy due to its sustained release characteristics and specific inhibition of the TRPV1 channel activated by hyperosmotic or desiccating stress. By performing transcriptome sequencing and experimental validation both in vivo and in vitro, we confirmed the mechanism of the TRPV1-Ca2+-Pyroptosis axis in the pathogenesis of DED. Our research provides novel perspectives on the understanding and treatment of DED, and introduces a potential ocular surface drug delivery system characterized by superior biosafety, prolonged retention, and improved therapeutic outcomes.

The role of TRPV1 in chronic prostatitis: a review.

Chronic prostatitis is a prevalent male urinary system disorder characterized by pelvic discomfort or pain, bladder dysfunction, sexual dysfunction, and infertility. Pain and lower urinary tract symptoms (LUTS) are the most common symptoms, significantly impacting patients' quality of life and driving them to seek medical attention. Transient receptor potential vanilloid subtype 1 (TRPV1) is a non-selective calcium ion-dependent cation channel in the TRPV channel family that is widely distributed in neural tissue and plays a role in signal transmission. In this review, we provide a comprehensive overview of the current understanding of the role of TRPV1 in chronic prostatitis. The discussion focuses on the connection between TRPV1 and prostatitis pain and LUTS, and highlights the potential for targeting this channel in the development of novel treatment strategies.

Mirtazapine Improves Locomotor Activity and Attenuates Neuropathic Pain Following Spinal Cord Injury in Rats via Neuroinflammation Modulation.

Neuroinflammation-related locomotor deficits and neuropathic pain are expected outcomes of spinal cord injury (SCI). The atypical antidepressant mirtazapine has exhibited potential neuroprotective and anti-inflammatory effects. This research aims to investigate the impacts of mirtazapine on post-SCI neuropathic pain and locomotor recovery, with a particular focus on neuroinflammation. The study utilized 30 male Wistar rats divided into five groups: Sham, SCI with vehicle treatment, and SCI administered with mirtazapine (3, 10, and 30mg/kg/day,ip, for one week). Locomotor activity was assessed using the Basso, Beattie, and Bresnahan (BBB) scale. Mechanical, thermal, and cold allodynia were assessed using von-Frey filaments, tail flick latency, and the acetone test, respectively. ELISA was utilized to measure cytokines, while Western blotting was used to determine TRPV1 channel, 5-HT2A receptor, NLRP3, and iNOS expression. Histopathological analyses were also examined, including hematoxylin and eosin (H&E) and Luxol fast blue (LFB) staining. Mirtazapine (10 and 30mg/kg/day) significantly improved locomotor recovery according to BBB score. It attenuated mechanical, thermal, and cold allodynia post-SCI. Moreover, it decreased pro-inflammatory cytokines TNF-α, IL-1β, IL-6, and IL-18, while increasing anti-inflammatory cytokine IL-4 and IL-10. Furthermore, it downregulated iNOS, NLRP3, and TRPV1 expression and upregulated the 5-HT2A receptor. H&E and LFB staining further revealed attenuated tissue damage and decreased demyelination. Our findings suggest that mirtazapine can alleviate neuropathic pain and reinforce locomotor recovery post-SCI by modulating neuroinflammatory responses, NLRP3, iNOS, TRPV1 channel, and 5-HT2A receptor expression.

Effect of capsaicin on monocyte differentiation in patients with chronic obstructive pulmonary disease

Introduction. It is known that monocytes and derived macrophages play an important role in the development of chronic obstructive pulmonary disease (COPD). Previously, we found that cigarette smoke-sensitive TRPV1 channels have higher expression on monocytes and macrophages of COPD patients.Aim. To investigate the effect of chronic TRPV1 activation on the differentiation of monocytes into macrophages in vitro.Materials and methods. The study included 11 patients with COPD and 7 healthy non-smoking volunteers (control). Monocytes were obtained from peripheral blood mononuclear cells by plastic adhesion. Cells were cultured for 10 days in the presence of granulocytemacrophage colony-stimulating factor (GM-CSF) or GM-CSF and the TRPV1 agonist capsaicin. On the 11th day, the cells were stimulated with lipopolysaccharides (LPS). Expression of the genes encoding the transcription factors STAT1, STAT6, IRF3, JUN, MAF, RELA, cytokines IL1B, IL6, IL8, and three reference genes B2M, RACK1 and HPRT1 was assessed by quantitative PCR with reverse transcription.Results. Initially, macrophages of COPD patients differentiated in the presence of GM-CSF had higher expression of STAT1 (2.98-fold, p=0.03) and JUN (1.6-fold, p=0.02). LPS stimulation was accompanied by upregulation of IRF3 (4.3-fold, p=0.04), RELA (1.3-fold, p=0.05) and interleukin genes. Under the action of LPS COPD macrophages had 3.2-fold higher expression of IRF3 as compared to the control (p=0.05). Capsaicin also caused upregulation of IRF3 in cells from COPD patients, thus the expression of this factor became 3.2-fold higher than in the control group (p=0.03). Differentiation with capsaicin sensitized macrophages to LPS. Under these conditions JUN expression increased both in COPD patients (1.8-fold, p=0.01) and in the control group (2.2-fold, p=0.02) as compared with cells differentiated with GM-CSF alone.Conclusion. The obtained results indicate that in resting state macrophages from COPD patients are mostly characterized by a proinflammatory M1 polarization. LPS probably leads to an additional polarization towards M2b phenotype, when compared with the control, as indicated by an increase in the level of IRF3 transcripts. Capsaicin also promotes M2b polarization of COPD macrophages and may enhance the inflammatory response of cells to LPS.

The multicomponent Passerini reaction as a means of accessing diversity in structure, activity and properties: Soft and hard vanilloid/cannabinoid modulators

A growing body of evidence points to the existence of a crosstalk between the endovanilloid (EV)- and the endocannabinoid (EC) systems, leading to the concept of a single system based on a shared set of endogenous ligands and regulation mechanisms. The EV/EC system encompasses the ion channel TRPV1, the G protein coupled receptors CB1 and CB2, their endogenous ligands and the enzymes for biosynthesis and inactivation. Disorders in which the EV/EC interaction is involved are inflammation, pain, neurodegenerative diseases and disorders of bones and skin.In the present paper, with the aim of targeting the EV/EC system, the Passerini reaction is used in a diversity-oriented approach to generate a series of α-acyloxycarboxamides bearing different substructures that resemble endogenous ligands. Compounds have been screened for activity on TRPV1, CB1 and CB2 and metabolic stability in skin cells, liver subcellular fractions and plasma. This protocol allowed to generate agents characterized by a diverse activity on TRPV1, CB1 and CB2, as well as heterogeneous metabolic stability that could allow different routes of administration, from soft drugs for topical treatment of skin diseases to hard drugs for systemic use in inflammation and pain. Compared to natural mediators, these compounds have a better drug-likeness. Among them, 41 stands out as an agonist endowed with a well-balanced activity on both TRPV1 and CB2, high selectivity over TRPM8, TRPA1 and CB1, metabolic stability and synthetic accessibility.

Inhibition of transient receptor potential vanilloid 3 channels by antimalarial hydroxychloroquine alleviates TRPV3-dependent dermatitis

Transient receptor potential vanilloid 3 channel (TRPV3) is closely associated with skin inflammation, but there is a lack of effective and specific inhibitors for clinical use. In this study, we identified antimalarial HCQ as a selective TRPV3 inhibitor following the prediction by network pharmacology data analysis. In whole-cell patch-clamp recordings, HCQ inhibited the current of the TRPV3 channel, with an IC50 of 51.69 ± 4.78 μM. At the single-channel level, HCQ reduced the open probability of TRPV3 and decreased single-channel conductance. Molecular docking and site-directed mutagenesis confirmed that residues in the pore domain were critical for the activity of HCQ. In vivo, HCQ effectively reduced carvacrol-induced epidermal thickening, erythema, and desquamation. Additionally, the serum IgE and inflammatory factors such as TNF-α and IL-6 were markedly decreased in the dorsal skin tissues in the HCQ treatment group, as compared to the model group. Our results suggested the antimalarial HCQ may represent a potential alleviator for treating skin inflammation by inhibiting TRPV3 channels.

Beyond the stings: Decoding the venom of the oak processionary caterpillar and navigating therapeutic innovation through TRPV1 channel insights

Beyond the stings: Decoding the venom of the oak processionary caterpillar and navigating therapeutic innovation through TRPV1 channel insights

Fallopian tube rheology regulates epithelial cell differentiation and function to enhance cilia formation and coordination

The rheological properties of the extracellular fluid in the female reproductive tract vary spatiotemporally, however, the effect on the behaviour of epithelial cells that line the tract is unexplored. Here, we reveal that epithelial cells respond to the elevated viscosity of culture media by modulating their development and functionality to enhance cilia formation and coordination. Specifically, ciliation increases by 4-fold and cilia beating frequency decreases by 30% when cells are cultured at 100 mPa·s. Further, cilia manifest a coordinated beating pattern that can facilitate the formation of metachronal waves. At the cellular level, viscous loading activates the TRPV4 channel in the epithelial cells to increase intracellular Ca2+, subsequently decreasing the mitochondrial membrane potential level for ATP production to maintain cell viability and function. Our findings provide additional insights into the role of elevated tubal fluid viscosity in promoting ciliation and coordinating their beating—a potential mechanism to facilitate the transport of egg and embryo, suggesting possible therapeutic opportunities for infertility treatment.