Modulation of Purinergic Signaling Attenuates Neuroinflammation and Edema in Experimental Cerebral Malaria

Extracellular ATP (eATP) is a potent danger signal that triggers immune responses and tissue damage^1-2. In experimental cerebral malaria (ECM), caused by Plasmodium berghei ANKA, excessive eATP in the central nervous system drives glial activation, neuroinflammation, and blood-brain barrier (BBB) dysfunction. Pannexin-1 (Panx1) channels mediate ATP release, while the ectonucleotidase CD39 counterbalances this cascade by hydrolyzing eATP. Here, we show that CD39−/− mice exhibited worsened clinical outcomes and accelerated mortality, whereas P2X7−/− mice, lacking a key eATP sensor, showed partial clinical protection, validating the Panx1/ATP/P2X7 axis as a driver of ECM immunopathology. Based on this, we investigated Panx1 inhibition using probenecid (PBN). PBN treatment significantly improved clinical outcomes, attenuating weight loss, neurological scores, and histopathological damage. Treated animals showed preserved BBB integrity and reduced cerebral edema. Notably, microglial and astrocyte morphology shifted from a pro-inflammatory amoeboid phenotype to a homeostatic ramified state, accompanied by reduced microglial TNF-α production. At 6 days post-infection, PBN treatment blunted neuroinflammation without preventing T cell infiltration. Pathogenic CD8+ and CD4+ T cells continued to accumulate in the brain and maintained CXCR3 expression. However, Panx1 blockade induced a functional disarmament of these cells, marked by a reduction in CX3CR1 expression and suppressed intracellular production of IFN-γ and granzyme B. Together, these results identify Panx1-mediated ATP release as a central driver of ECM immunopathology. Our findings highlight Panx1 inhibition as a promising neuroprotective strategy, suggesting that targeting purinergic signaling could serve as an essential adjunctive therapy to antimalarials to limit neuroinflammation and prevent severe neurological damage.

1.Nature (2014) 509:310

2.Front. Pharmacol. (2018) 9:52

FAPESP: 2025/05135-9  

CEUA:  1948280725