JAB1 promotes palmitate-induced insulin resistance via ERK pathway in hepatocytes.

Insulin resistance (IR) is the primary pathological mechanism underlying Type 2 diabetes mellitus (T2DM). Many researches have reported the relationship between chronic inflammation and IR, while the extracellular signal-regulated kinase 1/2 (ERK1/2) pathway is rapidly activated in inflammatory conditions. However, the functional role of ERK1/2 in IR remains to be identified. We here reported that C-Jun activation domain-binding protein-1 (JAB1) was upregulated in IR. In addition, we showed that depletion of JAB1 led to recovery of insulin sensitivity. Given the fact that JAB1 played as an activator of ERK1/2, we assumed JAB1 was involved in IR through ERK pathway. So we assessed the effects of JAB1 knockdown in palmitate acid (PA) treated HepG2 cells. Importantly, JAB1 siRNA blocked the effect of PA-induced activation of ERK1/2. Furthermore, silencing of JAB1 could reduce the release of inflammatory factors, facilitate hepatic glucose uptake and improve lipid metabolism. All these data implicated that JAB1 knockdown might alleviate PA-induced IR through ERK pathway in hepatocytes.