Src‐phosphorylation at the α1‐Na/K‐ATPase is Associated with Microbiota Community Changes in Diet‐Induced NASH in the Murine

Abstract

Background Obesity is a rising epidemic, leading to the increased prevalence of NAFLD/NASH (Non-alcoholic Fatty Liver Disease/Non-alcoholic steatohepatitis) that affects 25% of the US population. Gut microbiota has been implicated in NASH for its metabolic and inflammatory alterations, while the inhibition of Src phosphorylation (Src-p) signaling at the α1-Na/K-ATPase has been shown to attenuate established NASH. This study aimed to determine the effects of Src-p inhibition on gut microbiota communities and its association with NASH progression. Methods DNA from the terminal ileum microbiota habitat was obtained from rodents with diet induced NASH and amplified by PCR to develop DNA bacterial phylogenic sequence analysis of wild type and treated animals at 12, 24 and 48 weeks. For animals at 24 weeks, Src-p inhibition was correlated with liver morphological changes, intestinal CD4+/CD8+ ratio, and liver macrophage CD14+ expression. Differences among groups were evaluated by ANOVA/t-test and Principal Component Analysis (PCA). Results Microbiota communities varied significantly at all time points (12, 24 and 48 weeks, p<0.01, PCA), with an increase of Verrucomicrobia and a decrease of Bacteroidetes and Firmicutes in the HFD vs. NMC group. Microbiota communities regressed to their wild type state at 24 weeks through Src-p inhibition (p<0.05). This Src-p inhibited microbiota phenotype was associated with a decrease in liver inflammation and senescence, as well as associated with lower ileum CD4+ & CD8+ T cell levels and higher liver CD14+ expression (p<0.05). Conclusions Intestinal microbiota changes in NASH are significantly associated with Src-phosphorylation at the α1-Na/K-ATPase. Src-p inhibition returned microbiota communities to their wild type, concomitantly observed with amelioration of liver inflammation, cellular senescence, and both adaptive and innate immune responses in the gut and liver.