Methyl gallate nanomicelles impairs neutrophil accumulated in zymosan-induced arthritis.

Arthritis is a chronic disease that affects, approximately, 1 % of the total global population. It is characterized by chronic inflammation, accompanied in most of the cases of motor disability and sever pain. The main therapies available have high risk of failure and advanced treatments are scarce and highly cost. In this scenario, search for effective, safe and low-cost treatments is quite desirable. Methyl gallate (MG) is a plant-derived phenolic compound described to present remarkable anti-inflammatory effect in experimental models of arthritis. Thus, in this study we formulated nanomicelles of MG using Pluronic (F-127) as matrix and evaluated in vivo the pharmacokinetic, biodistribution and its effect in the mice model of zymosan-induced arthritis. The nanomicelles were formed with a size 126 nm. The biodistribution showed a ubiquitous tissue deposition with a renal excretion. The pharmacokinetics showed elimination half-life of 1.72 h and a clearance of 0.006 L/h. The oral pretreatment with nanomicelles containing MG (3.5 or 7 mg/kg) demonstrated a reduction in total leukocytes, neutrophils, and mononuclear cells from the inflammation site. The data supports the use of methyl gallate nanomicelles as an alternative drug for arthritis. DATA AVAILABILITY: All the data of this study are transparent.

P2Y2-P2X7 receptors cross-talk in primed mesenteric endothelial cells upregulates NF-κB signaling favoring mononuclear cell adhesion in schistosomiasis.

Schistosomiasis is an intravascular infectious disease that impacts over 200 million people globally. In its chronic stage, it leads to mesenteric inflammation with significant involvement of monocytes/macrophages. Endothelial cells lining the vessel lumens play a crucial role, and mount of evidence links this disease to a downregulation of endoprotective cell signaling favoring a primed and proinflammatory endothelial cell phenotype and therefore the loss of immunovascular homeostasis. One hallmark of infectious and inflammatory conditions is the release of nucleotides into the extracellular milieu, which, in turn, act as innate messengers, activating purinergic receptors and triggering cell-to-cell communication. ATP influences the progression of various diseases through P2X and P2Y purinergic receptor subtypes. Among these receptors, P2Y2 (P2Y2R) and P2X7 (P2X7R) receptors stand out, known for their roles in inflammation. However, their specific role in schistosomiasis has remained largely unexplored. Therefore, we hypothesized that endothelial P2Y2R and P2X7R could contribute to monocyte adhesion to mesenteric endothelial cells in schistosomiasis. Using a preclinical murine model of schistosomiasis associated with endothelial dysfunction and age-matched control mice, we showed that endothelial P2Y2R and P2X7R activation increased monocyte adhesion to cultured primary endothelial cells in both groups. However, a distinct upregulation of endothelial P2Y2R-driven canonical Ca2+ signaling was observed in the infected group, amplifying adhesion. In the control group, the coactivation of endothelial P2Y2R and P2X7R did not alter the maximal monocyte adhesion induced by each receptor individually. However, in the infected group, this coactivation induced a distinct upregulation of P2Y2R-P2X7R-driven canonical signaling, IL-1ß release, and VCAM-1 expression, with underlying mechanisms involving inflammasome and NF-κB signaling. Therefore, current data suggest that schistosomiasis alters endothelial cell P2Y2R/P2X7R signaling during inflammation. These discoveries advance our understanding of schistosomiasis. This intricate interplay, driven by PAMP-triggered endothelial P2Y2R/P2X7R cross-talk, emerges as a potential key player in the mesenteric inflammation during schistosomiasis.