RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: Panax notoginseng flowers, which are the buds of the traditional Chinese medicinal herb Sanqi, are widely used in China for their cough-ameliorating properties, with demonstrated therapeutic effects in the treatment of both acute and chronic coughs. However, both the antitussive mechanism and active compound basis of P. notoginseng flowers remain poorly understood. AIM OF THE STUDY: We investigated the antitussive effects of P. notoginseng flowers, identified the bioactive constituents responsible for alleviating cough symptoms, and elucidated the underlying pharmacological mechanisms. MATERIALS AND METHODS: We analyzed the major chemical constituents of aqueous extracts of P. notoginseng flowers using liquid chromatography-mass spectrometry and quantitatively analyzed the key component, 20S-ginsenoside Rh2, using high-performance liquid chromatography. Using a cough reflex model in healthy mice and an ovalbumin-induced, highly sensitive guinea pig cough model, we verified the suppressive effects of P. notoginseng flowers and their saponin constituents on coughing. Furthermore, we explored the mechanisms of action of the key ion channels, NaV1.7 and TRPV1, using whole-cell patch-clamp techniques and molecular docking. Finally, the therapeutic mechanisms of P. notoginseng flowers on pathological cough were revealed using hematoxylin and eosin staining, immunohistochemistry, and western blotting. RESULTS: The active components of P. notoginseng flowers were primarily protopanaxadiol-type saponins, among which 20S-ginsenoside Rh2 had the highest content (51.46 mg/g). In the mouse model, P. notoginseng flowers exhibited antitussive effects comparable to those of pentoxyverine citrate. Although its main saponin component, 20S-ginsenoside Rh2, showed slightly weaker effects, it still demonstrated concentration-dependent inhibition of channel activity. The whole-cell patch-clamp technique and virtual molecular docking showed that Rh2 might exert its effects by directly binding to the NaV1.7 and TRPV1 channels. In the guinea pig model, P. notoginseng flowers and their saponin components not only reduced cough frequency and prolonged the latency period before cough onset, but also significantly inhibited tracheal and pulmonary inflammation and the overexpression of TRPV1. CONCLUSIONS: 20S-Ginsenoside Rh2, the major bioactive saponin in P. notoginseng flowers, exhibits potent antitussive effects. The potential mechanism of action of 20S-Ginsenoside Rh2 in the treatment of cough may involve inhibiting NaV1.7 and TRPV1 channel currents through direct binding to core protein active sites and downregulating TRPV1 expression.

Asunto(s)

Antitusígenos , Tos , Regulación hacia Abajo , Flores , Ginsenósidos , Canal de Sodio Activado por Voltaje NAV1.7 , Panax notoginseng , Canales Catiónicos TRPV , Animales , Canales Catiónicos TRPV/metabolismo , Cobayas , Flores/química , Tos/tratamiento farmacológico , Ginsenósidos/farmacología , Antitusígenos/farmacología , Masculino , Ratones , Panax notoginseng/química , Regulación hacia Abajo/efectos de los fármacos , Humanos , Canal de Sodio Activado por Voltaje NAV1.7/metabolismo , Canal de Sodio Activado por Voltaje NAV1.7/efectos de los fármacos , Células HEK293 , Simulación del Acoplamiento Molecular , Cricetulus , Modelos Animales de Enfermedad , Células CHO , Saponinas/farmacología , Ovalbúmina

RESUMEN

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.

Asunto(s)

Metilación de ADN , Estrés Oxidativo , Enfermedad de Parkinson , Ratas Sprague-Dawley , Transducción de Señal , Canales Catiónicos TRPV , Animales , Ratas , Estrés Oxidativo/efectos de los fármacos , Masculino , Canales Catiónicos TRPV/metabolismo , Canales Catiónicos TRPV/genética , Enfermedad de Parkinson/genética , Enfermedad de Parkinson/metabolismo , Humanos , Modelos Animales de Enfermedad , Proteínas Quinasas Activadas por AMP/metabolismo , Proteínas Quinasas Activadas por AMP/genética , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas/genética , Oxidopamina , Epigénesis Genética , Oxigenasas de Función Mixta/metabolismo , Oxigenasas de Función Mixta/genética , Fármacos Neuroprotectores/farmacología , Dioxigenasas

RESUMEN

Alzheimer's disease (AD) is the leading form of dementia, characterized by the accumulation and aggregation of amyloid in brain. Transient receptor potential vanilloid 2 (TRPV2) is an ion channel involved in diverse physiopathological processes, including microglial phagocytosis. Previous studies suggested that cannabidiol (CBD), an activator of TRPV2, improves microglial amyloid-ß (Aß) phagocytosis by TRPV2 modulation. However, the molecular mechanism of TRPV2 in microglial Aß phagocytosis remains unknown. In this study, we aimed to investigate the involvement of TRPV2 channel in microglial Aß phagocytosis and the underlying mechanisms. Utilizing human datasets, mouse primary neuron and microglia cultures, and AD model mice, to evaluate TRPV2 expression and microglial Aß phagocytosis in both in vivo and in vitro. TRPV2 was expressed in cortex, hippocampus, and microglia.Cannabidiol (CBD) could activate and sensitize TRPV2 channel. Short-term CBD (1 week) injection intraperitoneally (i.p.) reduced the expression of neuroinflammation and microglial phagocytic receptors, but long-term CBD (3 week) administration (i.p.) induced neuroinflammation and suppressed the expression of microglial phagocytic receptors in APP/PS1 mice. Furthermore, the hyper-sensitivity of TRPV2 channel was mediated by tyrosine phosphorylation at the molecular sites Tyr(338), Tyr(466), and Tyr(520) by protein tyrosine kinase JAK1, and these sites mutation reduced the microglial Aß phagocytosis partially dependence on its localization. While TRPV2 was palmitoylated at Cys 277 site and blocking TRPV2 palmitoylation improved microglial Aß phagocytosis. Moreover, it was demonstrated that TRPV2 palmitoylation was dynamically regulated by ZDHHC21. Overall, our findings elucidated the intricate interplay between TRPV2 channel regulated by tyrosine phosphorylation/dephosphorylation and cysteine palmitoylation/depalmitoylation, which had divergent effects on microglial Aß phagocytosis. These findings provide valuable insights into the underlying mechanisms linking microglial phagocytosis and TRPV2 sensitivity, and offer potential therapeutic strategies for managing AD.

Asunto(s)

Péptidos beta-Amiloides , Lipoilación , Ratones Transgénicos , Microglía , Fagocitosis , Canales Catiónicos TRPV , Tirosina , Animales , Ratones , Microglía/metabolismo , Microglía/efectos de los fármacos , Canales Catiónicos TRPV/metabolismo , Péptidos beta-Amiloides/metabolismo , Fagocitosis/efectos de los fármacos , Humanos , Fosforilación/efectos de los fármacos , Tirosina/metabolismo , Lipoilación/efectos de los fármacos , Células Cultivadas , Enfermedad de Alzheimer/metabolismo , Cannabidiol/farmacología , Ratones Endogámicos C57BL , Canales de Calcio

RESUMEN

Sensing of noxious heat has been reported to be mediated by TRPV1, TRPA1, TRPM3, and ANO1 in mice, and this is redundant so that the loss of one receptor is at least partially compensated for by others. We have established an infusion-based human heat pain model. Heat-induced pain probed with antagonists for the four receptors did not match the redundancy found in mice. In healthy participants, only TRPV1 contributes to the detection of noxious heat; none of the other three receptors are involved. TRPV1 inhibition reduced the pain at all noxious temperatures, which can also be seen as an increase in the temperature that causes a particular level of pain. However, even if the TRPV1-dependent shift in heat detection is about 1°C, at the end of the temperature ramp to 52°C, most heat-induced pain remains unexplained. This difference between species reopens the quest for the molecular safety net for the detection of noxious heat in humans.

Asunto(s)

Calor , Canales Catiónicos TRPV , Sensación Térmica , Humanos , Canales Catiónicos TRPV/antagonistas & inhibidores , Canales Catiónicos TRPV/metabolismo , Masculino , Adulto , Animales , Femenino , Ratones , Estudios Cruzados , Dolor , Canal Catiónico TRPA1/metabolismo , Canal Catiónico TRPA1/genética , Canal Catiónico TRPA1/antagonistas & inhibidores , Adulto Joven

RESUMEN

The factors that contribute to pain after nerve injury remain incompletely understood. Laser-assisted in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK) are common surgical techniques to correct refractive errors. After LASIK or PRK, a subset of patients suffers intense and persistent pain, of unknown origin, described by patients as feeling like shards of glass in their eye. Here, we evaluated a TRPV1 variant, p.V527M, found in a 49-y-old woman who developed corneal pain after LASIK and subsequent PRK enhancement, reporting an Ocular Surface Disease Index score of 100. Using patch-clamp and Ca2+ imaging, we found that the V527M mutation enhances the response to acidic pH. Increasing proton concentration induced a stronger leftward shift in the activation curve of V527M compared to WT, resulting in channel activity of the mutant in acidic pH at more physiological membrane potentials. Finally, comparing the responses to consecutive applications of different agonists, we found in V527M channels a reduced capsaicin-induced desensitization and increased sensitization by the arachidonic acid metabolite 12-hydroxyeicosatetraenoic acid (12-HETE). We hypothesize that the increased response in V527M channels to protons and enhanced sensitization by 12-HETE, two inflammatory mediators released in the cornea after tissue damage, may contribute to the pathogenesis of corneal neuralgia after refractive surgery.

Asunto(s)

Bradiquinina , Capsaicina , Mutación , Neuralgia , Canales Catiónicos TRPV , Animales , Humanos , Ratas , Bradiquinina/metabolismo , Bradiquinina/farmacología , Capsaicina/farmacología , Córnea/metabolismo , Córnea/patología , Células HEK293 , Concentración de Iones de Hidrógeno , Neuralgia/genética , Neuralgia/metabolismo , Neuralgia/etiología , Queratectomía Fotorrefractiva/efectos adversos , Canales Catiónicos TRPV/genética , Canales Catiónicos TRPV/metabolismo

RESUMEN

Transient receptor potential (TRP) ion channels serve as sensors for variations in ambient temperature, modulating both thermoregulation and temperature responsive cellular processes. Among these, the vanilloid TRP subfamily (TRPV) comprises six members and at least four of these members (TRPV1-TRPV4) have been associated with thermal sensation. TRPV2 has been described as a sensor for noxious heat, but subsequent studies have unveiled a more complex role for TRPV2 beyond temperature perception. This comprehensive review aims to elucidate the intricate thermosensitivity of TRPV2 by synthesizing current knowledge on its biophysical properties, expression pattern and known physiological functions associated with thermosensation.

Asunto(s)

Canales Catiónicos TRPV , Sensación Térmica , Canales Catiónicos TRPV/metabolismo , Humanos , Animales , Sensación Térmica/fisiología , Regulación de la Temperatura Corporal/fisiología

RESUMEN

Ginger, a Zingeberaceae family member, is notable for its anti-inflammatory properties. This study explores the pharmaceutical mechanisms of ginger and red palm wax co-extract, developing novel niosomal formulations for enhanced transdermal delivery. Evaluations included physical characteristics, drug loading, in vitro release, network pharmacology, molecular docking, and biocompatibility. The niosomal ginger with red palm wax gel (NGPW) exhibited non-Newtonian fluid properties. The optimized niosome formulation (cholesterol: Tween80: Span60 = 12.5: 20: 5 w/w) showed a high yield (93.23 %), high encapsulation efficiency (54.71 %), and small size (264.33 ± 5.84 nm), prolonging in vitro anti-inflammatory activity. Human skin irritation and biocompatibility tests on 1 % NGPW showed favorable cytotoxicity and hemocompatibility results (ISO10993). Network pharmacology identified potential targets, while molecular docking highlighted high affinities between gingerol and red palm wax compounds with TRPM8 and TRPV1 proteins, suggesting pain inhibition via serotonergic synapse pathways. NGPW presents a promising transdermal pain inhibitory drug delivery strategy.

Asunto(s)

Liposomas , Simulación del Acoplamiento Molecular , Zingiber officinale , Zingiber officinale/química , Humanos , Liposomas/química , Geles/química , Extractos Vegetales/química , Extractos Vegetales/farmacología , Alcoholes Grasos/química , Alcoholes Grasos/farmacología , Catecoles/química , Catecoles/farmacología , Canales Catiónicos TRPV/metabolismo , Antiinflamatorios/farmacología , Antiinflamatorios/química , Liberación de Fármacos , Ceras/química , Ceras/farmacología

RESUMEN

Neuropathic pain, a common symptom of several disorders, exerts a substantial socioeconomic burden worldwide. Transient receptor potential vanilloid 1 (TRPV1), a non-selective cation channel predominantly ex-pressed in nociceptive neurons, plays a pivotal role in nociception, by detecting various endogenous and exogenous stimuli, including heat, pro-inflammatory mediators, and physical stressors. Dysregulation of TRPV1 signaling further contributes to the pathophysiology of neuropathic pain. Therefore, targeting TRPV1 is a promising strategy for developing novel analgesics with improved efficacy and safety profiles. Several pharmacological approaches to modulate TRPV1 activity, including agonists, antagonists, and biological TRPV1 RNA interference (RNAi, small interfering RNA [siRNA]) have been explored. Despite preclinical success, the clinical translation of TRPV1-targeted therapies has encountered challenges, including hyperthermia, hypothermia, pungency, and desensitization. Nevertheless, ongoing research efforts aim to refine TRPV1-targeted interventions through structural modifications, development of selective modulators, and discovery of natural, peptide-based drug candidates. Herein, we provide guidance for researchers and clinicians involved in the development of new interventions specifically targeting TRPV1 by reviewing the existing literature and highlighting current research activities. This study further discusses potential future research endeavors for enhancing the efficacy, safety, and tolerability of TRPV1 candidates, and thereby facilitates the translation of these discoveries into effective clinical interventions to alleviate neuropathic pain disorders.

Asunto(s)

Neuralgia , Canales Catiónicos TRPV , Canales Catiónicos TRPV/antagonistas & inhibidores , Canales Catiónicos TRPV/metabolismo , Neuralgia/tratamiento farmacológico , Neuralgia/metabolismo , Humanos , Animales , Analgésicos/farmacología , Analgésicos/uso terapéutico

RESUMEN

Ursolic acid (UA), a pentacyclic triterpene, exhibits diverse pharmacological effects, including potential treatment for allergic diseases. It downregulates thymic stromal lymphopoietin (TSLP) and disrupts mast cell signaling pathways. However, the exact molecular mechanism by which UA interferes with mast cell action remains unclear. Therefore, the current study aimed to uncover molecular entities underlying the effect of UA on mast cells and its potential antipruritic effect, specifically investigating its modulation of key molecules such as TRPV4, PAR2, and MRGPRX2, which are involved in TSLP regulation and sensation. Calcium imaging experiments revealed that UA pretreatment significantly suppressed MRGPRX2 activation (and its mouse orthologue MrgprB2), a G protein-coupled receptor predominantly expressed in mast cells. Molecular docking predictions suggested potential interactions between UA and MRGPRX2/MrgprB2. UA pretreatment also reduced mast cell degranulation through MRGPRX2 and MrgprB2-dependent mechanisms. In a dry skin mouse model, UA administration decreased tryptase and TSLP production in the skin, and diminished TSLP response in the sensory neurons. While PAR2 and TRPV4 activation enhances TSLP production, UA did not inhibit their activity. Notably, UA attenuated compound 48/80-induced scratching behaviors in mice and suppressed spontaneous scratching in a dry skin model. The present study confirms the effective inhibition of UA on MRGPRX2/MrgprB2, leading to reduced mast cell degranulation and suppressed scratching behaviors. These findings highlight the potential of UA as an antipruritic agent for managing various allergy- or itch-related conditions.

Asunto(s)

Degranulación de la Célula , Citocinas , Mastocitos , Receptores Acoplados a Proteínas G , Linfopoyetina del Estroma Tímico , Triterpenos , Ácido Ursólico , Animales , Mastocitos/efectos de los fármacos , Mastocitos/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Degranulación de la Célula/efectos de los fármacos , Citocinas/metabolismo , Ratones , Triterpenos/farmacología , Proteínas del Tejido Nervioso/metabolismo , Proteínas del Tejido Nervioso/genética , Canales Catiónicos TRPV/metabolismo , Prurito/tratamiento farmacológico , Prurito/metabolismo , Simulación del Acoplamiento Molecular , Receptores de Neuropéptido/metabolismo , Masculino , Piel/efectos de los fármacos , Piel/metabolismo

RESUMEN

Chronic low-grade inflammation (CLGI) is associated with obesity and is one of its pathogenetic mechanisms. Lipopolysaccharide (LPS), a component of Gram-negative bacterial cell walls, is the principal cause of CLGI. Studies have found that capsaicin significantly reduces the relative abundance of LPS-producing bacteria. In the present study, TRPV1-knockout (TRPV1-/-) C57BL/6J mice and the intestinal epithelial cell line Caco-2 (TRPV1-/-) were used as models to determine the effect of capsaicin on CLGI and elucidate the mechanism by which it mediates weight loss in vivo and in vitro. We found that the intragastric administration of capsaicin significantly blunted increases in body weight, food intake, blood lipid, and blood glucose in TRPV1-/- mice fed a high-fat diet, suggesting an anti-obesity effect of capsaicin. Capsaicin reduced LPS levels in the intestine by reducing the relative abundance of Proteobacteria such as Helicobacter, Desulfovibrio, and Sutterella. Toll-like receptor 4 (TLR4) levels decreased following decreases in LPS levels. Then, the local inflammation of the intestine was reduced by reducing the expression of tumor necrosis factor (TNF)-α and interleukin (IL)-6 mediated by TLR4. Attenuating local intestinal inflammation led to the increased expression of tight junction proteins zonula occludens 1 (ZO-1) and occludin and the restoration of the intestinal barrier function. Capsaicin increased the expression of ZO-1 and occludin at the transcriptional and translational levels, thereby increasing trans-endothelial electrical resistance and restoring intestinal barrier function. The restoration of intestinal barrier function decreases intestinal permeability, which reduces the concentration of LPS entering the circulation, and reduced endotoxemia leads to decreased serum concentrations of inflammatory cytokines such as TNF-α and IL-6, thereby attenuating CLGI. This study sheds light on the anti-obesity effect of capsaicin and its mechanism by reducing CLGI, increasing our understanding of the anti-obesity effects of capsaicin. It has been confirmed that capsaicin can stimulate the expression of intestinal transmembrane protein ZO-1 and cytoplasmic protein occludin, increase the trans-epithelial electrical resistance value, and repair intestinal barrier function.

Asunto(s)

Capsaicina , Inflamación , Lipopolisacáridos , Ratones Endogámicos C57BL , Obesidad , Canales Catiónicos TRPV , Receptor Toll-Like 4 , Animales , Obesidad/metabolismo , Obesidad/tratamiento farmacológico , Capsaicina/farmacología , Canales Catiónicos TRPV/metabolismo , Canales Catiónicos TRPV/genética , Inflamación/metabolismo , Inflamación/tratamiento farmacológico , Humanos , Ratones , Receptor Toll-Like 4/metabolismo , Células CACO-2 , Ratones Noqueados , Dieta Alta en Grasa/efectos adversos , Masculino , Ocludina/metabolismo , Ocludina/genética , Proteína de la Zonula Occludens-1/metabolismo , Proteína de la Zonula Occludens-1/genética , Mucosa Intestinal/metabolismo , Mucosa Intestinal/efectos de los fármacos

RESUMEN

Endometriosis is a chronic inflammatory disease that causes debilitating pelvic pain in women. Macrophages are considered to be key players in promoting disease progression, as abundant macrophages are present in ectopic lesions and elevated in the peritoneum. In the present study, we examined the role of GATA6+ peritoneal macrophages on endometriosis-associated hyperalgesia using mice with a specific myeloid deficiency of GATA6. Lesion induction induced the disappearance of TIM4hi MHCIIlo residential macrophages and the influx of increased Ly6C+ monocytes and TIM4lo MHCIIhi macrophages. The recruitment of MHCIIhi inflammatory macrophages was extensive in Mac Gata6 KO mice due to the severe disappearance of TIM4hi MHCIIlo residential macrophages. Ki67 expression confirmed GATA6-dependent proliferative ability, showing different proliferative phenotypes of TIM4+ residential macrophages in Gata6f/f and Mac Gata6 KO mice. Peritoneal proinflammatory cytokines were elevated after lesion induction. When cytokine levels were compared between Gata6f/f and Mac Gata6 KO mice, TNFα at day 21 in Gata6f/f mice was higher than in Mac Gata6 KO mice. Lesion induction increased both abdominal and hind paw sensitivities. Gata6f/f mice tended to show higher sensitivity in the abdomen after day 21. Elevated expression of TRPV1 and CGRP was observed in the dorsal root ganglia after ELL induction in Gata6f/f mice until days 21 and 42, respectively. These results support that peritoneal GATA6+ macrophages are involved in the recruitment and reprogramming of monocyte-derived macrophages. The extensive recruitment of monocyte-derived macrophages in Mac Gata6 KO mice might protect against inflammatory stimuli during the resolution phase, whereas GATA6 deficiency did not affect lesion initiation and establishment at the acute phase of inflammation. GATA6+ residential macrophages act to sustain local inflammation in the peritoneum and sensitivities in the neurons, reflecting endometriosis-associated hyperalgesia.

Asunto(s)

Endometriosis , Factor de Transcripción GATA6 , Macrófagos Peritoneales , Animales , Femenino , Ratones , Citocinas/metabolismo , Modelos Animales de Enfermedad , Endometriosis/inmunología , Endometriosis/patología , Endometriosis/metabolismo , Ganglios Espinales/metabolismo , Ganglios Espinales/inmunología , Factor de Transcripción GATA6/metabolismo , Factor de Transcripción GATA6/genética , Hiperalgesia/etiología , Hiperalgesia/metabolismo , Hiperalgesia/inmunología , Macrófagos Peritoneales/inmunología , Macrófagos Peritoneales/metabolismo , Ratones Endogámicos C57BL , Ratones Noqueados , Peritoneo/patología , Peritoneo/inmunología , Canales Catiónicos TRPV/metabolismo , Canales Catiónicos TRPV/genética

RESUMEN

The conjunctiva has immune-responsive properties to protect the eye from infections. Its innate immune system reacts against external pathogens, such as fungi. The complement factor C5a is an important contributor to the initial immune response. It is known that activation of transient-receptor-potential-vanilloid 1 (TRPV1) and TRP-melastatin 8 (TRPM8) channels is involved in different immune reactions and inflammation in the human body. The aim of this study was to determine if C5a and mucor racemosus e voluminae cellulae (MR) modulate Ca2+-signaling through changes in TRPs activity in human conjunctival epithelial cells (HCjECs). Furthermore, crosstalk was examined between C5a and MR in mediating calcium regulation. Intracellular Ca2+-concentration ([Ca2+]i) was measured by fluorescence calcium imaging, and whole-cell currents were recorded using the planar-patch-clamp technique. MR was used as a purified extract. Application of C5a (0.05-50 ng/mL) increased both [Ca2+]i and whole-cell currents, which were suppressed by either the TRPV1-blocker AMG 9810 or the TRPM8-blocker AMTB (both 20 µM). The N-terminal peptide C5L2p (20-50 ng/mL) blocked rises in [Ca2+]i induced by C5a. Moreover, the MR-induced rise in Ca2+-influx was suppressed by AMG 9810 and AMTB, as well as 0.05 ng/mL C5a. In conclusion, crosstalk between C5a and MR controls human conjunctival cell function through modulating interactions between TRPV1 and TRPM8 channel activity.

Asunto(s)

Calcio , Complemento C5a , Conjuntiva , Células Epiteliales , Humanos , Células Epiteliales/metabolismo , Células Epiteliales/microbiología , Conjuntiva/metabolismo , Conjuntiva/microbiología , Calcio/metabolismo , Complemento C5a/metabolismo , Canales de Potencial de Receptor Transitorio/metabolismo , Señalización del Calcio , Canales Catiónicos TRPV/metabolismo

RESUMEN

Inflammatory arthritis leads to peripheral nerve sensitization, but the therapeutic effect is often unsatisfactory. Our preliminary studies have found that in mice with inflammatory arthritis, the use of ionotropic glutamate receptor antagonists can produce a good analgesic effect without altering foot swelling, suggesting that pain relief may be related to the improvement of neuropathic pain. However, the underlying mechanisms remain unclear. To further investigate the effects of neuropathic pain medications on inflammatory arthritis and the impact of the ionotropic glutamate receptor NR2B subunit (NR2B) on inflammatory arthritis, this study employed gabapentin (GBP) treatment on the inflammatory arthritis mouse model (the adjuvant induced arthritis, AIA), and we found a significant reduction in pain. Further studies revealed that in AIA, the expression levels of NR2B, TRPV1, pain-related molecules (substance P, PGE2), inflammatory cytokines (IL-1, IL-6, TNF-α, and GM-CSF) and Ca2+ were elevated in the foot and dorsal root ganglia (DRG). GBP treatment was able to influence the downregulation of the expression levels of NR2B, TRPV1, pain-related molecules, inflammatory cytokines and Ca2+. Mechanistic studies have shown that GBP treatment affects the downregulation of NR2B, and the downregulation of NR2B expression leads to the downregulation of TRPV1, pain-related molecules and inflammatory cytokines, thereby alleviating pain. These results suggest that in peripheral sensitization caused by AIA, GBP can play a role in improving pain, and NR2B may be a key target of peripheral nerve sensitization induced by inflammatory arthritis. GBP provides a theoretical basis for the clinical treatment of inflammatory arthritis.

Asunto(s)

Analgésicos , Gabapentina , Receptores de N-Metil-D-Aspartato , Animales , Receptores de N-Metil-D-Aspartato/metabolismo , Receptores de N-Metil-D-Aspartato/antagonistas & inhibidores , Gabapentina/farmacología , Masculino , Ratones , Analgésicos/farmacología , Artritis Experimental/tratamiento farmacológico , Artritis Experimental/metabolismo , Ganglios Espinales/metabolismo , Ganglios Espinales/efectos de los fármacos , Neuralgia/tratamiento farmacológico , Neuralgia/metabolismo , Canales Catiónicos TRPV/metabolismo , Citocinas/metabolismo , Artritis/tratamiento farmacológico , Artritis/metabolismo , Artritis/inducido químicamente

RESUMEN

Sexual dimorphism among mammals includes variations in the pain threshold. These differences are influenced by hormonal fluctuations in females during the estrous and menstrual cycles of rodents and humans, respectively. These physiological conditions display various phases, including proestrus and diestrus in rodents and follicular and luteal phases in humans, distinctly characterized by varying estrogen levels. In this study, we evaluated the capsaicin responses in male and female mice at different estrous cycle phases, using two murine acute pain models. Our findings indicate that the capsaicin-induced pain threshold was lower in the proestrus phase than in the other three phases in both pain assays. We also found that male mice exhibited a higher pain threshold than females in the proestrus phase, although it was similar to females in the other cycle phases. We also assessed the mRNA and protein levels of TRPV1 in the dorsal root and trigeminal ganglia of mice. Our results showed higher TRPV1 protein levels during proestrus compared to diestrus and male mice. Unexpectedly, we observed that the diestrus phase was associated with higher TRPV1 mRNA levels than those in both proestrus and male mice. These results underscore the hormonal influence on TRPV1 expression regulation and highlight the role of sex steroids in capsaicin-induced pain.

Asunto(s)

Capsaicina , Dolor , Canales Catiónicos TRPV , Animales , Canales Catiónicos TRPV/metabolismo , Canales Catiónicos TRPV/genética , Capsaicina/farmacología , Masculino , Femenino , Ratones , Dolor/metabolismo , Dolor/genética , Hormonas Esteroides Gonadales/metabolismo , Ciclo Estral/efectos de los fármacos , Umbral del Dolor/efectos de los fármacos , Ganglios Espinales/metabolismo , Ganglios Espinales/efectos de los fármacos , Ganglio del Trigémino/metabolismo , Ganglio del Trigémino/efectos de los fármacos , Regulación de la Expresión Génica/efectos de los fármacos , Caracteres Sexuales , ARN Mensajero/metabolismo , ARN Mensajero/genética

RESUMEN

The potential role of the transient receptor potential Vanilloid 1 (TRPV1) non-selective cation channel in gastric carcinogenesis remains unclear. The main objective of this study was to evaluate TRPV1 expression in gastric cancer (GC) and precursor lesions compared with controls. Patient inclusion was based on a retrospective review of pathology records. Patients were subdivided into five groups: Helicobacter pylori (H. pylori)-associated gastritis with gastric intestinal metaplasia (GIM) (n = 12), chronic atrophic gastritis (CAG) with GIM (n = 13), H. pylori-associated gastritis without GIM (n = 19), GC (n = 6) and controls (n = 5). TRPV1 expression was determined with immunohistochemistry and was significantly higher in patients with H. pylori-associated gastritis compared with controls (p = 0.002). TRPV1 expression was even higher in the presence of GIM compared with patients without GIM and controls (p < 0.001). There was a complete loss of TRPV1 expression in patients with GC. TRPV1 expression seems to contribute to gastric-mucosal inflammation and precursors of GC, which significantly increases in cancer precursor lesions but is completely lost in GC. These findings suggest TRPV1 expression to be a potential marker for precancerous conditions and a target for individualized treatment. Longitudinal studies are necessary to further address the role of TRPV1 in gastric carcinogenesis.

Asunto(s)

Infecciones por Helicobacter , Neoplasias Gástricas , Canales Catiónicos TRPV , Humanos , Canales Catiónicos TRPV/metabolismo , Canales Catiónicos TRPV/genética , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patología , Masculino , Femenino , Persona de Mediana Edad , Anciano , Infecciones por Helicobacter/metabolismo , Infecciones por Helicobacter/complicaciones , Infecciones por Helicobacter/patología , Carcinogénesis/metabolismo , Carcinogénesis/patología , Estudios Retrospectivos , Lesiones Precancerosas/metabolismo , Lesiones Precancerosas/patología , Helicobacter pylori/patogenicidad , Metaplasia/metabolismo , Metaplasia/patología , Gastritis/metabolismo , Gastritis/patología , Gastritis/microbiología , Adulto , Inmunohistoquímica , Mucosa Gástrica/metabolismo , Mucosa Gástrica/patología , Gastritis Atrófica/metabolismo , Gastritis Atrófica/patología

RESUMEN

Olfactory perception is an important physiological function for human well-being and health. Loss of olfaction, or anosmia, caused by viral infections such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has received considerable attention, especially in persistent cases that take a long time to recover. This review discusses the integration of different components of the olfactory epithelium to serve as a structural and functional unit and explores how they are affected during viral infections, leading to the development of olfactory dysfunction. The review mainly focused on the role of receptors mediating the disruption of olfactory signal transduction pathways such as angiotensin converting enzyme 2 (ACE2), transmembrane protease serine type 2 (TMPRSS2), neuropilin 1 (NRP1), basigin (CD147), olfactory, transient receptor potential vanilloid 1 (TRPV1), purinergic, and interferon gamma receptors. Furthermore, the compromised function of the epithelial sodium channel (ENaC) induced by SARS-CoV-2 infection and its contribution to olfactory dysfunction are also discussed. Collectively, this review provides fundamental information about the many types of receptors that may modulate olfaction and participate in olfactory dysfunction. It will help to understand the underlying pathophysiology of virus-induced anosmia, which may help in finding and designing effective therapies targeting molecules involved in viral invasion and olfaction. To the best of our knowledge, this is the only review that covered all the receptors potentially involved in, or mediating, the disruption of olfactory signal transduction pathways during COVID-19 infection. This wide and complex spectrum of receptors that mediates the pathophysiology of olfactory dysfunction reflects the many ways in which anosmia can be therapeutically managed.

Asunto(s)

Anosmia , COVID-19 , SARS-CoV-2 , Humanos , COVID-19/metabolismo , COVID-19/complicaciones , COVID-19/fisiopatología , COVID-19/virología , Anosmia/fisiopatología , Anosmia/etiología , Anosmia/metabolismo , Enzima Convertidora de Angiotensina 2/metabolismo , Mucosa Olfatoria/metabolismo , Mucosa Olfatoria/virología , Transducción de Señal , Serina Endopeptidasas/metabolismo , Neuropilina-1/metabolismo , Basigina/metabolismo , Canales Catiónicos TRPV/metabolismo

RESUMEN

Acute nociceptive pain in mice caused by subcutaneous (intraplantar) injection of TRPV1 ion channel agonist capsaicin (1.6 µg/mouse) and the effects of protein kinase A inhibitor H-89 (0.05 mg/mouse, intraplantar injection) and NMDA receptor channel antagonists MK-801 (7.5 and 15 µg/mouse, topical application) and hemantane (0.5 mg/mouse, topical application) on the pain were assessed. MK-801 and hemantane were found to reduce the duration of the pain response. H-89 did not significantly affect the pain in animals, but preliminary administration of this drug abolished the antinociceptive effect of MK-801 (7.5 µg/mouse) and weakens the effect of hemantane (0.5 mg/mouse).

Asunto(s)

Analgésicos , Capsaicina , Maleato de Dizocilpina , Receptores de N-Metil-D-Aspartato , Animales , Capsaicina/farmacología , Ratones , Receptores de N-Metil-D-Aspartato/antagonistas & inhibidores , Masculino , Maleato de Dizocilpina/farmacología , Analgésicos/farmacología , Canales Catiónicos TRPV/antagonistas & inhibidores , Canales Catiónicos TRPV/metabolismo , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Proteínas Quinasas Dependientes de AMP Cíclico/antagonistas & inhibidores , Inhibidores de Proteínas Quinasas/farmacología , Dolor Nociceptivo/tratamiento farmacológico , Dolor Nociceptivo/inducido químicamente , Dimensión del Dolor/efectos de los fármacos , Dimensión del Dolor/métodos

RESUMEN

INTRODUCTION: The olfactory and trigeminal system are closely interlinked. Existing literature has primarily focused on characterizing trigeminal stimulation through mechanical and chemical stimulation, neglecting thermal stimulation thus far. The present study aimed to characterize the intranasal sensitivity to heat and the expression of trigeminal receptors (transient receptor potential channels, TRP). METHODS: A total of 20 healthy participants (aged 21-27 years, 11 women) were screened for olfactory function and trigeminal sensitivity using several tests. Under endoscopic control, a thermal stimulator was placed in 7 intranasal locations: anterior septum, lateral vestibulum, interior nose tip, lower turbinate, middle septum, middle turbinate, and olfactory cleft to determine the thermal threshold. Nasal swabs were obtained in 3 different locations (anterior septum, middle turbinate, olfactory cleft) to analyze the expression of trigeminal receptors TRP: TRPV1, TRPV3, TRPA1, TRPM8. RESULTS: The thermal threshold differed between locations (p = 0.018), with a trend for a higher threshold at the anterior septum (p = 0.092). There were no differences in quantitative receptor expression (p = 0.46) at the different sites. The highest overall receptor RNA expression was detected for TRPV1 over all sites (p<0.001). The expression of TRPV3 was highest at the anterior septum compared to the middle turbinate or the olfactory cleft. The thermal sensitivity correlated with olfactory sensitivity and results from tests were related to trigeminal function like intensity ratings of ammonium, a questionnaire regarding trigeminal function, nasal patency, and CO2 thresholds. However, no correlation was found between receptor expression and psychophysical measures of trigeminal function. DISCUSSION: This study provided the first insights about intranasal thermal sensitivity and suggested the presence of topographical differences in thermal thresholds. There was no correlation between thermal sensitivity and trigeminal mRNA receptor expression. However, thermal sensitivity was found to be associated with psychophysical measures of trigeminal and olfactory function.

Asunto(s)

Mucosa Nasal , Canales Catiónicos TRPV , Humanos , Femenino , Adulto , Masculino , Mucosa Nasal/metabolismo , Adulto Joven , Canales Catiónicos TRPV/metabolismo , Canales Catiónicos TRPV/genética , Calor , Nervio Trigémino/fisiología , Nervio Trigémino/metabolismo , Umbral Sensorial/fisiología , Canales de Potencial de Receptor Transitorio/metabolismo , Canales de Potencial de Receptor Transitorio/genética , Canales Catiónicos TRPM/metabolismo , Canales Catiónicos TRPM/genética , Sensación Térmica/fisiología , Canal Catiónico TRPA1/metabolismo , Canal Catiónico TRPA1/genética

RESUMEN

Neuroimmune cross-talk participates in intestinal tissue homeostasis and host defense. However, the matrix of interactions between arrays of molecularly defined neuron subsets and of immunocyte lineages remains unclear. We used a chemogenetic approach to activate eight distinct neuronal subsets, assessing effects by deep immunophenotyping, microbiome profiling, and immunocyte transcriptomics in intestinal organs. Distinct immune perturbations followed neuronal activation: Nitrergic neurons regulated T helper 17 (TH17)-like cells, and cholinergic neurons regulated neutrophils. Nociceptor neurons, expressing Trpv1, elicited the broadest immunomodulation, inducing changes in innate lymphocytes, macrophages, and RORγ+ regulatory T (Treg) cells. Neuroanatomical, genetic, and pharmacological follow-up showed that Trpv1+ neurons in dorsal root ganglia decreased Treg cell numbers via the neuropeptide calcitonin gene-related peptide (CGRP). Given the role of these neurons in nociception, these data potentially link pain signaling with gut Treg cell function.

Asunto(s)

Péptido Relacionado con Gen de Calcitonina , Ganglios Espinales , Neuroinmunomodulación , Nociceptores , Linfocitos T Reguladores , Canales Catiónicos TRPV , Células Th17 , Animales , Ratones , Péptido Relacionado con Gen de Calcitonina/metabolismo , Péptido Relacionado con Gen de Calcitonina/genética , Neuronas Colinérgicas/metabolismo , Ganglios Espinales/metabolismo , Ganglios Espinales/citología , Microbioma Gastrointestinal , Intestinos/inmunología , Intestinos/citología , Macrófagos/inmunología , Macrófagos/metabolismo , Ratones Endogámicos C57BL , Nocicepción , Nociceptores/metabolismo , Miembro 3 del Grupo F de la Subfamilia 1 de Receptores Nucleares/metabolismo , Linfocitos T Reguladores/inmunología , Linfocitos T Reguladores/metabolismo , Células Th17/inmunología , Canales Catiónicos TRPV/metabolismo , Canales Catiónicos TRPV/genética

RESUMEN

The prevalence of bacterial infections significantly increases among patients with severe traumatic brain injury (STBI), leading to a notable rise in mortality rates. While immune dysfunctions are linked to the incidence of pneumonia, our observations indicate that endogenous pathogens manifest in the lungs post-STBI due to the migration of gut commensal bacteria. This translocation involves gut-innervating nociceptor sensory neurons, which are crucial for host defense. Following STBI, the expression of transient receptor potential vanilloid 1 (TRPV1) in dorsal root ganglion (DRG) neurons significantly decreases, despite an initial brief increase. The timing of TRPV1 defects coincides with the occurrence of pulmonary infections post-STBI. This alteration in TRPV1+ neurons diminishes their ability to signal bacterial injuries, weakens defense mechanisms against intestinal bacteria, and increases susceptibility to pulmonary infections via bacterial translocation. Experimental evidence demonstrates that pulmonary infections can be successfully replicated through the chemical ablation and gene interference of TRPV1+ nociceptors, and that these infections can be mitigated by TRPV1 activation, thereby confirming the crucial role of nociceptor neurons in controlling intestinal bacterial migration. Furthermore, TRPV1+ nociceptors regulate the immune response of microfold cells by releasing calcitonin gene-related peptide (CGRP), thereby influencing the translocation of gut bacteria to the lungs. Our study elucidates how changes in nociceptive neurons post-STBI impact intestinal pathogen defense. This new understanding of endogenous risk factors within STBI pathology offers novel insights for preventing and treating pulmonary infections.

Asunto(s)

Lesiones Traumáticas del Encéfalo , Nociceptores , Canales Catiónicos TRPV , Animales , Lesiones Traumáticas del Encéfalo/metabolismo , Lesiones Traumáticas del Encéfalo/microbiología , Canales Catiónicos TRPV/metabolismo , Nociceptores/metabolismo , Ratones , Masculino , Ganglios Espinales/metabolismo , Traslocación Bacteriana , Intestinos/microbiología , Ratones Endogámicos C57BL , Microbioma Gastrointestinal/fisiología , Pulmón/metabolismo , Pulmón/microbiología