Aim: 

Adipocyte differentiation-related protein (ADRP) plays a central role in the formation of lipid droplets. The present study was aimed to investigate if changes in ADRP expression were coupled with the extent of fat accumulation and with the lipid droplet morphology in rat hepatocytes.

Methods: 

Lipid accumulation in hepatic cells was induced in rats by high fat diet (HFD) or, alternatively, by culturing isolated hepatocytes for 24 h in DMEM supplemented with 1 mM Oleic/0.5 mM Palmitic acids (O/P). Lipid accumulation and lipid droplet morphology were assessed by Oil Red-O and Nile Red staining, ADRP protein was detected by immunostaining. In parallel, the expression of ADRP was assessed by quantitative real-time RT-PCR.

Results: 

In rat hepatocytes, fat-induced lipid accumulation, both in vivo and in vitro, was associated with an induction of ADRP expression and with a drastic increase in ADRP-positive droplets when compared to controls. Moreover, the lipid droplet morphology was modified as a function of the extent of fat accumulation in the cell.

Conclusion: 

The observed increase in ADRP expression induced by hepatocyte exposure to fats both in vivo and in vitro confirms the role of ADRP in promoting the formation of lipid droplets to store the excess of lipid intake. Therefore, ADRP could represent a reliable and sensitive marker of fatty liver.