Purinergic Signalling最新文献

Periodontal disease (PD) is characterized by the presence of a chronic inflammatory process, due to the accumulation of bacterial biofilm and the host's response to these pathogens, resulting in the destruction of the supporting tissues of dental structures. Studies have revealed that components of the purinergic system and inflammation are related to the development and progression of PD. The objective was to evaluate periodontal clinical parameters, modulation of the purinergic system and inflammation in patients with PD, compared to individuals without the disease. This is a cross-sectional study with 25 healthy individuals (CT group) and 57 individuals with PD, where blood and saliva collection and isolation of blood components were carried out. The results showed that there was a significant reduction in the hydrolysis of adenosine triphosphate (ATP; p < 0.0001), adenosine diphosphate (ADP; p < 0.05) and adenosine monophosphate (AMP; p < 0.01) in peripheral blood mononuclear cells (PBMCs) from individuals in the PD group compared to the CT group, indicating that individuals with PD showed reduced NTPDase 1 and Ecto-5'-nucleotidase activity. Adenosine deaminase activity in saliva (p < 0.0001) and serum p < 0.05) from individuals with PD were significantly higher compared to the CT group. Extracellular ATP and the serum concentration of C-Reactive Protein showed a statistically significant increase in the PD group ((p < 0.0001 and p < 0.001, respectively). Therefore, the enzymes of the purinergic system are present in the modulation of PD, leading individuals affected by the disease to a pro-inflammatory state, hindering the action of the immune system and increasing serum markers of inflammation.

Neuroblastoma is a pediatric tumor accounting for approximately 8% of childhood cancers and is associated with high mortality rates among children aged 1 to 5 years. Standard treatments often fall short, leading to recurrence and metastasis due to the development of chemoresistance. A promising approach to address this challenge involves targeting purinergic signaling pathways and drug repurposing. The combination of flubendazole in nanoformulation and vincristine exhibited synergistic effects in ACN cells, enhancing treatment efficacy. Vincristine combined with the P2X7 receptor antagonist Brilliant Blue-G showed antagonistic effects, and interactions between nanoFBZ and Brilliant Blue-G were dose-dependent. Furthermore, ACN cells exposed to 213 nM of vincristine weekly for three weeks resulted in vincristine-resistant cells with significantly higher resistance (IC₅₀ approximately 300 times greater) compared to parental cells. P2Y₂ receptor expression was augmented in vincristine-resistant cells, particularly after treatment with nanoFBZ and Brilliant Blue-G, while adenosine A1, A2B, and P2Y₆ receptor expression levels decreased. P2X7 receptor expression was also reduced in vincristine-resistant cells treated with nanoFBZ. P2X7 receptor agonism and P2Y₂ receptor blockade slightly elevated resistance. In conclusion, this study suggests that combining nanoFBZ with vincristine chemotherapy may offer a promising strategy for improving the treatment efficacy of neuroblastoma. The synergy between nanoFBZ and vincristine enhanced therapeutic outcomes, and P2X7 receptor antagonism further reduced neuroblastoma cell viability.

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.

Over the past few years, transcriptomics has emerged as a pillar for modern scientific research, enabling the comprehensive profiling of gene expression. The availability of large-scale public datasets, such as NCBI Gene Expression Omnibus, International Cancer Genome Consortium, and The Cancer Genome Atlas, has significantly boosted many scientific discoveries. However, to analyze and interpret these vast datasets, sophisticated bioinformatic tools are often necessary. Phantasus is a user-friendly web application designed to streamline gene expression analysis. By integrating data loading, normalization, filtering, enrichment pathways analysis, and principal component analysis, Phantasus enables researchers to promptly investigate and evaluate complex gene expression patterns. This tool simplifies the identification of differentially expressed genes and the discovery of novel biological insights. Here, we demonstrate how Phantasus can be utilized for gene expression analysis in glioblastoma (GBM), the most common primary malignant brain tumour in adults. Specifically, we focus on the role of purinergic signaling, with particular emphasis on the P2RX7 mRNA coding for the P2X7 receptor (P2RX7). To illustrate our proposal, we analyzed the expression of genes related to purinergic signaling in GBM patients stratified by high and low levels of P2RX7 expression. By harnessing Phantasus, researchers can further explore and navigate the nuances of gene regulation and its impact on human health and diseases.

Elevated interleukin-6 (IL-6) levels are linked to an increased risk of cardiovascular mortality in myocardial infarction (MI). Targeting IL-6 and its downstream signalling pathways represents a therapeutic strategy; however, its cellular sources and regulatory mechanisms of IL-6 remain incompletely understood. In this study, Alter and colleagues investigated the primary cell type that produces IL-6 in post-MI murine heart and the role of purinergic signalling in regulating IL-6 formation. Using cellular and mouse models, the authors identified cardiac fibroblasts as the predominant source of IL-6. Further analysis revealed that the IL-6 formation in cardiac fibroblasts is regulated by adenosine A_2B receptors. Of further importance, they elucidated that T cells highly express CD73, leading to significant adenosine formation, which in turn enhances IL-6 production via Gq activation in cardiac fibroblasts following MI. These findings reveal a dynamic interplay between immune cells and fibroblasts in shaping the post-MI inflammatory response. This study suggests the adenosine-A_2B receptor-IL6 axis as a potential therapeutic target to mitigate inflammation and improve cardiomyocytes salvage in MI.

The P2X7 receptor is an adenosine triphosphate (ATP)-gated ion channel expressed in different cell types of the brain. Polymorphisms in the P2RX7 gene have repeatedly been associated with psychiatric disorders including major depression. Depression is a stress-related disorder in which a dysregulation of the immune system has attracted increasing attention as a potential disease mechanism. The well-documented role of P2X7 in inflammatory conditions advocates its involvement in immune system dysregulation and depression genesis. However, understanding its exact role requires further research using appropriate animal models. Unfortunately, some of the most widely used P2X7 knockout mouse models are limited in their utility by the continuous expression of certain P2rx7 splice variants or even activation of de novo transcripts. To overcome this limitation, we generated a novel constitutive and complete P2X7 KO mouse line. These KO mice lack all known murine splice variants and protein expression resulting in a loss-of-function as confirmed by calcium imaging and by the inability of P2X7-deficient peritoneal macrophages to mount an appropriate interleukin (IL)-1β response. Comprehensive characterization using a battery of tests assessing locomotion, anxiety- and depression-related as well as social behaviour revealed differences in locomotor and exploratory behaviours. P2X7 KO mice showed slightly increased locomotor activity and reduced anxiety-related behaviour at baseline. Under conditions of chronic stress exposure, genotype-dependent differences largely dissolved while P2X7 deficiency promoted enhanced stress resilience with regard to social behaviour. Taken together, our findings add further evidence for an involvement of the P2X7 in shaping different behavioural responses and their modulation by stressful environments. This novel loss-of-function model will contribute to a better understanding of P2X7 in stress-associated behaviours in basic and translational neuropsychiatric research.

Hormonal contraceptives, one of the most widely used contraceptive methods, are associated with the development of thromboembolism. Purinergic mediators such as soluble agonists, ectonucleotidases, and receptors play a prominent role in regulating hemostasis. This study aimed to evaluate E-NTPDase, E-5'-NT, and E-ADA activities in lymphocytes and platelets from women using combined oral contraceptives. Participants used third-generation (3G) oral contraceptives, such as drospirenone or cyproterone acetate, or fourth-generation (4G) oral contraceptives, such as gestodene or desogestrel, both combined with ethinylestradiol. The findings indicated decreased adenosine (ADO) deamination in lymphocytes (78%, p < 0.001) and decreased AMP hydrolysis (69%, p < 0.01) and ADO deamination (66%, p < 0.001) in platelets from women using 3G contraceptives compared with the control. Furthermore, the results showed decreased ADO deamination (66%, p < 0.05) in lymphocytes and decreased ATP hydrolysis (52%, p < 0.05) and decreased ADO deamination (57%, p < 0.001) in platelets from women using 4G contraceptives compared with the control. The observed patterns of AMP hydrolysis are compatible with an ADO-poor vascular microenvironment. Likewise, the decrease in E-ADA activity may be associated with lower concentrations of ADO in the vascular microenvironment, which has antiplatelet and anti-inflammatory effects. Overall, the findings demonstrated that hormonal contraceptives alter the activity of purinergic ectoenzymes, which might be related to their effects on hemostasis and a predisposition to thromboembolic events.

Immunotherapies, such as immune checkpoint inhibitors (ICI), anti-cancer vaccines and adoptive T cell transfer, are promising treatments for cancer patients. However, ICI have not shown therapeutic benefit for most mismatch repair-proficient colorectal and pancreatic ductal adenocarcinoma tumors (PDAC), which are aggressive and deadly (Li et al. in Biomedicines 12:2175, 2024). Tumor metabolism can enhance immunological tolerance, but hinder immune cell function. In a recent publication in Nature Cancer, Scolaro et al. (Scolaro et al. in Nature Cancer 5:1206-1226, 2024) showed that cytidine deaminase (CDA) upregulation may play a crucial role in shaping the immunosuppressive landscape of human PDAC and other tumors. CDA targeting in pancreatic cancer cell lines led to reduced tumor growth, weight and total regression after treatment aimed at the programmed cell death protein 1 receptor (PD-1) immune checkpoint protein. CDA inhibition, both genetically and pharmacologically, overcame immunotherapy resistance in PDAC models. CDA targeting in PDAC cells altered the tumor microenvironment (TME), enabling T cells to respond to anti-PD-1. In mice with sgNT and sgCda tumors receiving anti-PD-1 treatment, they reduced the number of CD8⁺ T cells. CDA reduction in cancer cells makes tumors more sensitive to immunotherapy, presumably by overcoming immunosuppressive tumor-associated macrophages (TAMs) and forcing them to adopt an immunostimulatory phenotype. The study also found that cancer cells produce a TME rich in UDP (and UTP) by taking advantage of the CDA-mediated pyrimidine salvage pathway. This setting inhibits the recruitment and activation of CD8⁺ T cells by promoting the infiltration and immunosuppressive characteristics of P2Y₆ receptor-expressing TAMs.