Deficiency of CKIP-1 aggravates high-fat diet-induced fatty liver in mice

•CKIP-1 deficiency aggravates fatty liver in mice fed with high-fat diet.•CKIP-1 deficiency exacerbates insulin resistance in mice fed with high-fat diet.•CKIP-1 deficiency increases hepatic pJNK1 and pIRS1 in mice fed with high-fat diet.•CKIP-1 deficiency enhances JNK1 phosphorylation in hepatocytes in vitro.•There is the interaction and co-location between CKIP-1 and JNK1 in cells in vitro.

Casein kinase 2 interacting protein-1(CKIP-1) is widely expressed in a variety of tissues and cells, and plays an important role in various critical cellular and physiological processes including cell growth, apoptosis, differentiation, cytoskeleton and bone formation. Here, we found: (1) CKIP-1 deficient mice exhibited increased body weight, liver weight, number and size of lipid droplets, and TG content comparing with WT mice after being exposed to high fat diet (HFD); (2) the levels of serum insulin, liver glycogen, phosphorylated C-Jun-N-terminal kinase-1 (pJNK1) and phosphorylated insulin receptor substrate −1(pIRS1) in CKIP-1-/- mice were higher than those of WT mice; (3) CKIP-1 interacted with JNK1 in vitro. Our results indicate that CKIP-1 deficiency in mice aggravates HFD-induced fatty liver by upregulating JNK1 phosphorylation and further upregulating IRS-1 phosphorylation and RI.