Hepatic DKK1 driven steatosis is CD36-dependent

With the improvement of people's living standards and lifestyle changes, nonalcoholic fatty liver disease (NAFLD) has become one of the most common chronic liver diseases worldwide. However, few drugs are available for NAFLD, partly due to an incomplete understanding of its pathogenic mechanisms. Here, using in vivo and in vitro gain- and loss-of function approaches, we identified DKK1 as a pivotal mediator of the progression of NAFLD and its accompanying metabolic disorders in dietary obese mice. Mechanistic study reveals that DKK1 enhances the capacity of hepatocytes to uptake fatty acids through ERK-PPARγ-CD36 pathway. Moreover, DKK1 increased insulin resistance by activating the JNK signaling pathway, which in turn exacerbates disorders of hepatic lipid metabolism. These results suggest that DKK1 is a regulator of fatty acid uptake in lipid metabolism and insulin signaling, and may be a potential therapeutic candidate for NAFLD hepatocyte mRNA profiles of overexpression DKK1 (OE-DKK1) and green fluorescent protein negative control (GFP-NC) AML12 cells treated with 0.5mM free fatty acid (FFA ) for 24 hours.