PRDX1 is involved in palmitate induced insulin resistance via regulating the activity of p38MAPK in HepG2 cells.

ABSTRACT

Studies have identified that type 2 diabetes mellitus (T2DM) patients displayed higher levels of plasma peroxiredoxin1(PRDX1) than non-diabetics. However, the impact of PRDX1 on insulin resistance and the underlying mechanism remains totally unknown. Here, we investigated the influence of PRDX1 on hepatic insulin resistance. We showed that the protein and mRNA levels of PRDX1 were significantly elevated under insulin-resistant conditions. In addition, we showed that interference of PRDX1 ameliorated palmitate-induced insulin resistance in HepG2 cells, which was indicated by elevated phosphorylation of protein kinase B (AKT) and of glycogen synthase kinase-3 (GSK3ß). Furthermore, the expression of phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase), two key gluconeogenic enzymes, were down-regulated following PRDX1 depletion. Accordingly, glucose uptake was suppressed in PRDX1-interferred HepG2 cells. In addition, Over-expression of PRDX1 enhanced PA-induced insulin resistance in HepG2 cells. Moreover, we found that knocking down PRDX1 improves insulin sensitivity and decreased the activation of p38 mitogen-activated protein kinase (p38MAPK). Our results demonstrate that PRDX1 can induce hepatic insulin resistance by activating p38MAPK signaling and identifies potential targets for new treatments.