Caveolin-1 modulates P2X7R-mediated monocyte adhesion and shows increased colocalization with endothelial P2X7R during schistosomiasis

Introduction: Chronic schistosomiasis induces persistent mesenteric vascular inflammation due to intravascular Schistosoma mansoni and eggs. Endothelial injury releases ATP activating purinergic receptors. Schistosomiasis alters endothelial function and increases leukocyte adhesion [PLoS One (2011) 6:e23547]. Increased Cav-1 degradation is linked to endothelial dysfunction [Front. Immunol. (2023) 14:1254762]. We previously demonstrated that P2Y2 and P2X7 receptors (P2Y2R/P2X7R) act cooperatively, amplifying NF-κB and inflammasome signaling, IL-1β release and monocyte adhesion [Front. Immunol. (2024) 14:1328897]. Here, we investigated the potential interaction between endothelial P2X7R and Cav-1 in mesenteric inflammation during schistosomiasis. Methods: Primary mesenteric endothelial cells (MECs) from control and infected mice (50-70 dpi; CEUA-UFRJ 124/22) were stimulated with vehicle or ATP (500 µM, 10 min), with or without Cav-1 silencing (siRNA; 1 pmol, 48 h). Monocytes isolated by Ficoll-Paque PLUS were co-incubated with MECs (10⁴/well, 30 min); four fields/well were imaged to quantify adhesion. Cav-1/P2X7R colocalization was evaluated by double immunofluorescence using confocal microscopy (Zeiss Celldiscover 7/LSM 900) and analyzed with Puncta Analyzer. Results: Cav-1 knockdown was confirmed in both groups. In the control group, Cav-1 silencing did not affect monocyte adhesion in response to P2X7R activation (p = 0.99, ATP vs. siRNA Cav-1 + ATP). However, in the infected group, silencing reduced monocyte adhesion in response to P2X7R activation from 9.2 ± 0.6 to 6.2 ± 0.3 cells/field (p < 0.001; n = 4), restoring basal levels. Cav-1/P2X7R colocalization increased from 6.5 ± 0.9 to 10.0 ± 1.4 puncta in MECs from infected group (p < 0.01). Conclusion: Altogether, our data suggest that endothelial P2X7R signaling is modulated by Cav-1 during schistosomiasis, with increased P2X7R/Cav-1 colocalization potentially contributing to mesenteric vascular inflammation.