Purinergic Signalling最新文献

Interactions of effector T cells with laminins during their trafficking across basement membranes play a crucial role in the development of the adaptive immune response and inflammatory diseases. However, the mechanisms involved in this process are not fully understood. In this study, we report that human Th17 cells express and use integrins α3 and α6 to migrate in laminin 10, which is predominant in basement membranes. We showed that laminin 10 induces via integrins α3 and α6, a sustained release of ATP from the mitochondria through pannexin-1 hemichannels, and that extracellular ATP is necessary for Th17 cell migration suggesting the implication of purinergic signaling. Inhibition studies identified a major role for the ionotropic purinergic receptor P2X4 in Th17 cell migration whereas purinergic receptors P2X7 and P2Y₁₁ had no role. Along these lines, our results showed that laminin 10 induced calcium entry into Th17 cells via the P2X4 receptor. Together these results show that integrins α3 and α6 induce Th17 cell migration by activating the P2X4 receptor. Our findings uncovered a crosstalk between laminin-binding integrins and purinergic signaling in promoting human Th17 cell migration and suggest that this pathway can play an important role in the immune response.

Polycystic kidney diseases (PKD) are a group of inherited nephropathies marked by the formation of fluid-filled cysts along the nephron, which cause renal failure. Bulk RNA sequencing of microdissected renal cysts from Pkd1^RC/RC mice identifies 4,970 differentially expressed genes in comparison to intact collecting ducts. A poorly understood factor of cyst growth is the high ATP level in the cyst fluid, probably released by pannexin-1 hemichannels. Here, we evaluate a novel pannexin-1 inhibitor SIL14 as a potential therapeutic agent for cyst reduction and investigate proteins involved in cystogenesis, with a focus on purinergic signaling. In patch-clamp experiments, acute SIL14 application demonstrated strong, dose-dependent inhibition of Pannexin-1-dependent currents (IC₅₀ = 12.96 µM). Chronic treatment of renal collecting duct cells with 30 μM SIL14 significantly reduced cyst size in a Matrigel model of cyst formation. Notably, RNA sequencing reveals that purinergic receptors P2Y2 and P2Y4, normally expressed in collecting ducts, were downregulated, while P2X5, P2X7, P2Y6, and P2Y12 were upregulated in the cystic epithelium. Stimulation with α,βMe-ATP or Bz-ATP (P2X7 agonists) increased cyst size and pannexin-1 expression in Matrigel cultures. Our findings indicate that the transition of normal collecting ducts to cystic epithelium is accompanied by distorted purinergic signaling and propose inhibition of luminal ATP release via pannexin-1 is a potential method to limit cystogenesis.

Metabolic syndrome (MetS) is a cluster of interrelated and co-occurring metabolic disorders, including abdominal obesity, hyperglycemia, dyslipidemia, the reduced high-density lipoprotein (HDL) cholesterol, and/or hypertension. Cardiovascular diseases are the leading causes of death and disability in metabolic syndrome. Each component of MetS is an independent risk factor for cardiovascular diseases, and the combination of these factors can increase the incidence and severity of cardiovascular diseases, such as atherosclerosis, myocardial infarction, and heart failure, with atherosclerosis being the primary cause of cardiovascular-related death in MetS. The specific pathogenic mechanism in the occurrence and development of atherosclerosis in MetS is still not fully understood. An increasing number of studies have shown that the purinergic signaling pathway plays a significant role in atherosclerosis. ATP and ADP, key signaling molecules in the purinergic signaling pathway, are not only involved in cellular energy metabolism but also activate the purinergic signaling pathway by binding to P1 and P2 purinergic receptors (P1R and P2R), regulating vascular contraction and relaxation, and inhibiting platelet aggregation. Purinergic signaling can act as both a promoter and a resistance factor in the formation of atherosclerosis, depending on the receptor subtype and downstream signaling network. This review summarizes the specific roles and mechanisms of the purinergic signaling network in MetS-related atherosclerosis and analyzes the clinical application of targeting the purinergic signaling pathway, providing a theoretical basis and innovative ideas for basic research and clinical treatment in this field.

Postoperative pain following hemorrhoid surgery is often accompanied by emotional and cognitive disturbances, complicating recovery. Acupuncture has shown promise in modulating pain and related neuroinflammatory pathways. A rat model of mixed hemorrhoid surgery was established in seventy male Sprague-Dawley rats, and randomly divided into seven groups: control, model, acupuncture, non-acupoint acupuncture, P2X7 agonist (BzATP), normal saline, and acupuncture + agonist. Behavioral assays including open field, sucrose preference, and Von Frey tests evaluated motor activity, anhedonia, and mechanical pain threshold. ELISA measured IL-6 and TNF-α levels. ATP concentration was assessed by colorimetric assay. RT-qPCR quantified P2X7 mRNA expression. Western blot and immunohistochemistry assessed P2X7 and p-ERK protein expression in dorsal root ganglia (DRG). P2X7 antagonist A-438079 was also used to validate the involvement of P2X7 in acupuncture-mediated effects. Mind-regulating and pain-relieving acupuncture significantly improved locomotion, sucrose preference, and pain threshold compared to the model group (P < 0.01), while non-acupoint and agonist treatments showed no significant benefits. Acupuncture increased ATP levels and decreased IL-6 and TNF-α levels in DRG tissues (P < 0.01). P2X7 and p-ERK expression were elevated in the model group and suppressed following acupuncture, as confirmed by qPCR, Western blot, and immunohistochemistry. The P2X7 agonist reversed many of acupuncture's beneficial effects, indicating a role of the P2X7/ERK signaling pathway. Notably, co-administration of the P2X7 selective antagonist A-438079 counteracted the detrimental effects of BzATP and restored behavioral and biochemical outcomes to acupuncture-treated levels. Mind-regulating and pain-relieving acupuncture alleviates postoperative pain and reduces depressive-like behavior and locomotor impairments in a rat model of mixed hemorrhoids, likely through suppression of peripheral P2X7/ERK signaling and inflammation. These findings highlight P2X7 as a therapeutic target in postoperative pain and underscore the translational relevance of P2X receptors.

Neutrophils are essential effector cells of the innate immune system, acting as the first line of defense against infection and tissue injury. Among the purinergic receptors expressed in these cells, P2Y14 has gained increasing attention in recent years for its role in modulating neutrophil recruitment and activation in inflammatory contexts. This receptor is activated mainly by uridine diphosphoglucose (UDP-glucose) and other UDP-sugars released during cellular stress or damage. Through the activation of G protein-coupled pathways, particularly via Gi/o and RhoA signaling, P2Y14 influences key neutrophil functions, including chemotaxis, cytoskeletal rearrangements, and oxidative responses. Despite its pro-inflammatory potential, and the increasing amount of literature data in recent years, P2Y14's complete physiological and pathological roles remain underexplored. Literature data also highlight its involvement in diseases like glioblastoma and COVID-19, where, due to increased neutrophil infiltration, it exacerbates inflammation, tissue damage, and stress. Therefore, targeting P2Y14 may be a promising strategy to modulate neutrophil chemotaxis and mitigate unwanted harmful inflammatory responses. This review discusses the characteristics and signaling mechanisms of P2Y14 in neutrophils, as well as the relevant implications of this pathway for neutrophil function.

Individual variability in stress responses contributes to susceptibility or resilience to mood and anxiety disorders. The adenosinergic system, particularly A1 and A2A receptors, modulates synaptic activity in brain regions involved in emotional regulation, including the nucleus accumbens (NAc), a central hub of reward processing and stress responsivity. Despite high adenosine receptor expression in the NAc, their specific role in stress resilience remains poorly understood. Here, we investigated the effects of 10 days of chronic social defeat stress (CSDS) on A1 and A2A receptor expression and synaptic proteins in the NAc of male C57BL/6 mice categorized as resilient (RES) or susceptible (SS) based on their sociability. SS mice exhibited social avoidance and elevated anxiety-like behaviors, whereas RES mice behaved comparably to controls. Neurochemical analyses revealed that RES mice had lower A2A receptor mRNA levels and decreased PSD-95 expression, suggesting reduced excitatory synaptic tone, while A1 receptor and gephyrin levels remained unchanged. To assess whether baseline adenosine signaling predicts stress vulnerability, we applied a caffeine responsiveness index. Caffeine, a non-selective adenosine receptor antagonist (7.5 mg/kg, i.p.), was used to classify Swiss mice as caffeine-responsive or non-responsive based on its psychostimulant effects, which are primarily attributed to A2A receptor antagonism. Following a 14-day washout, animals were exposed to chronic variable stress (CVS), and caffeine-responsive mice showed deficits in motivational and exploratory behaviors. Together, these findings indicate that lower A2A receptor signaling in the NAc supports stress resilience, whereas heightened baseline caffeine sensitivity may predict vulnerability to stress-induced affective disturbances.

Microglial activation drives neuroinflammation, a key factor in many neurological diseases. The purinergic system is a major regulator of inflammatory responses and represents a promising target for controlling neuroinflammation. Capsaicin, a bioactive compound found in chili peppers, exhibits significant anti-inflammatory and antioxidant properties. This study aimed to investigate the modulatory effects of capsaicin on microglial activation and purinergic system regulation. For this, BV-2 microglial cells were exposed to lipopolysaccharide (1 μg/mL) and treated with capsaicin (25 and 50 μM) for 24 hours. Cell viability was assessed by MTT and trypan blue assays. Cell cycle and apoptosis were evaluated by flow cytometry. Nitric oxide, reactive species and malondialdehyde levels were evaluated as markers of oxidative stress. Activities of NTPDase, 5'-nucleotidase (5'-NT), and adenosine deaminase (ADA) were evaluated. Gene expression of inflammatory mediators and purinergic receptors were analyzed by qRT-PCR, and molecular docking analyses were performed. As a result, capsaicin decreased the expression of pro-inflammatory mediators (NLRP3, CASP-1, IL-1β, IL-6, and TNF-α), increased IL-10 expression, and attenuated oxidative stress. It reduced NTPDase, 5'-NT, and ADA activities, downregulated P2X7 and A2A receptor expression, and upregulated A1 receptor expression. Molecular docking revealed that capsaicin has a high affinity for the A1 and A2A receptors, as well as for ADA. Collectively, these findings suggest that capsaicin exerts neuroprotective effect by suppressing pro-inflammatory signaling, enhancing anti-inflammatory responses, reducing oxidative stress, and modulating key components of the purinergic system, including ectoenzyme activities and P2X7, A1, and A2A receptor expression.

The epithelial sodium channel (ENaC) localized in the cell membrane is crucial for sodium transport and blood pressure regulation. Discovered in frog skin, ENaC is expressed in the colon, lungs, exocrine glands, and most notably in the distal nephron of the kidneys, where it limits sodium reabsorption. Mutations in ENaC cause hereditary hypertension (Liddle's syndrome) or hypotension (pseudohypoaldosteronism type 1). ENaC activity and expression are tightly controlled by various signaling molecules and second messengers. For example, urinary ATP binding to the P2Y2 receptor inhibits ENaC. ENaC also interacts with PI(4,5)P2 and the ubiquitin ligase Nedd4-2 via specific motifs. PI(4,5)P2 is essential for ENaC stability, trafficking, and gating. This review focuses on the regulatory roles of the P2Y2 receptor and PI(4,5)P2 on ENaC regulation.

Atherosclerosis, a chronic inflammatory disease driven by lipid deposition and immune cell activation, remains a leading cause of cardiovascular morbidity and mortality. Emerging evidence highlights the role of purinergic signalling in atherogenesis, particularly the P2Y₆ receptor in macrophages [1]. Using RNA sequencing, proteomics, expression and functional validation in cells, mouse models and human materials, this study provides comprehensive mechanistic insights into how macrophage P2Y₆ receptors contribute to foam cell formation and plaque development through the phospholipase Cβ (PLCβ)/store-operated Ca²⁺ entry/calreticulin/scavenger receptor A (SR-A) pathway. Furthermore, the study identifies thiamine pyrophosphate (TPP) as a potent P2Y₆ receptor antagonist, effectively inhibiting foam cell formation and reducing plaque burden in atherosclerotic mice, without inducing toxicity. These findings establish P2Y₆ receptors as promising therapeutic targets in atherosclerosis and introduce TPP as a potential clinical candidate for intervention.