Antagonism of Na,K‐ATPase signaling by pNaKtide can attenuate systemic inflammatory response in murine sepsis model induced by cecal ligation and puncture

Abstract

IntroductionOxidative stress and associated inflammatory processes are crucial in the development and progression of sepsis, resulting in an immune response that leads to multiple organ failure or dysfunction. Hence, the strategies to limit this systemic inflammatory response might result in the development of an effective sepsis therapy. Previous studies from our lab have demonstrated the role of Na/K‐ATPase signaling in exacerbating systemic oxidative stress and inflammation and the potential role of Na/K‐ATPase signaling antagonist, pNaKtide, in ameliorating several pathophysiological abnormalities.HypothesisThe aim of this study is to demonstrate the role of Na,K‐ATPase signaling in exacerbating oxidant stress and inflammatory response noted in a murine model of sepsis. Furthermore, we aim to demonstrate the effect of systemic administration of Na,K‐ATPase signaling antagonist, pNaKtide, in experimental sepsis using cecal ligation and puncture (CLP) model, as a drug intervention against septic shock.MethodMurine sepsis was induced by CLP in male C57BL6 mice with or without pNaKtide (25 mg/kg body wt) which was administered, intraperitoneally, 24 hours before CLP procedure. Sham surgery was performed without the ligation and puncture, which served as controls for the study. All mice were assessed for Murine Sepsis Score (MSS) at baseline (before Sham or CLP), at 4hours, 8hours and 24 hours after Sham or CLP. Mice were euthanized after 24 hours of Sham or CLP surgery and tissues were collected for morphological and biochemical assessment. Blood was used to measure plasma levels of inflammatory cytokines.ResultsSystemic administration of pNaKtide demonstrated improved MSS at 24 hours following CLP surgery, as compared to CLP mice without pNaKtide. Histological assessment of lung tissues by H&E staining showed significantly less congestion, edema, infiltration of inflammatory cells and hemorrhage in CLP mice administered with pNaKtide, as compared to CLP alone. pNaKtide also improved systemic inflammatory cytokines assessed by plasma levels of TNFα and MCP1, as well as improved mRNA expression of inflammatory and macrophage infiltration markers, in lung tissues of CLP mice.ConclusionOur study demonstrates that antagonism of Na,K‐ATPase signaling by pNaKtide may attenuate CLP‐induced sepsis by inhibition of inflammatory milieu noted in this pathophysiological condition. Hence, Na,K‐ATPase signaling may serve as a viable clinical target for therapeutic intervention of sepsis and associated inflammatory mechanisms.