Análise dos efeitos da indometacina na infecção por SARS-CoV-2 e na resposta inflamatória associada ao sistema purinérgico

Abstract

Indomethacin (INDO) reduces SARS-CoV replication in vitro and in vivo, but its effects against SARS-CoV-2 are poorly known. In addition to possible direct antiviral effects, we hypothesized that INDO could also modulate SARS-CoV-2-induced inflammatory response. The purinergic system controls extracellular metabolism and signaling activated by ATP which, in a viral infection process, is released by infected cells and can activate, via the P2X7 receptor, the release of pro-inflammatory cytokines. Furthermore, ATP, by itself, can act as a chemoattractant and recruit immune cells to the site of injury. In this study we evaluated whether INDO alters the cytopathic effect of SARS-CoV-2 in Vero E6 and Calu-3 cells and whether INDO alters the inflammatory response induced by the serum from patients with severe COVID-19 (intensive care unit) in peripheral blood mononuclear cells (PBMCs), by measuring selected targets involved in purinergic signalling. INDO protected cells against SARS-CoV-2 infection [multiplicity of infection (MOI) 0.1 and 0.01]- and COVID-19 serum stimulusinduced cytopathic effect. Experimental data revealed an IC50 of 50 µM for INDO in Vero E6 cells upon MOI 0.01. INDO (10 µM) completely abolished the cytopathic effect in Calu-3 and PBMCs. In addition, PBMCs exposed to serum from COVID-19 patients presented higher extracellular ATP hydrolytic activity than cells exposed to control serum. The addition of 10 μM and 100 μM INDO drastically reduced COVID-19 serum-induced increase of extracellular ATP hydrolysis. SARS-CoV-2 exposure increased the expression of P2X7 receptor, CD39 and CD73 in Vero E6 cells. Interestingly, 10 μM INDO also suppressed SARS-CoV-2 infectioninduced increase of TNF-α in the supernatant of PBMCs and Vero E6 cultures. Reactive oxygen species were also reduced in the Vero E6 cell line supernatant after treatment of 10 μM INDO. Taken together, our results suggest that INDO protects against SARS-CoV-2-induced cytopathic effects and suppresses ATP-associated inflammatory responses. Thus, this drug may be an excellent candidate for the treatment of COVID-19.