Role of Perilipin 2 in microvesicular hepatic steatosis induced by CGI-58 specific knockout in mice

Objective To explore whether hepatocyte Perilipin-2 (Plin2) is involved in the development of fatty liver related to comparative gene identification-58 (CGI-58) deficiency mice and compare the effects of Plin2 and Plin3 on lipid droplet formation and lipid accumulation. Methods Based on CGI-58Flox/Flox mice as animal model, the adeno-associated viruses targeting mouse liver, CGI-58 knockout and Plin2 knockdown were achieved by co-expression Cre protein and micro-RNA targeting Plin2 (Mi-KD). Then CGI-58 deficiency mice were used as control (NC) to detect the differences in metabolic phenotype and liver pathology. AML-12 mouse hepatocytes were used as cellular model and interfered with siRNA to achieve Plin2/Plin3 knockdown in AML-12 cells. Lipid droplet formation and lipid accumulation were compared with Bodipy staining and enzyme colorimetry in basal condition or lipid-overloaded condition (OA inducement) after Plin2/Plin3 knockdown. Results Plin2 knockdown (Mi-KD) reduced PLIN2 protein level by >99% in mouse livers. Mi-KD decreased hepatomegaly (P=0.019 5) and liver injury (P=0.000 4), while reduced the histological NAS score (P=0.000 2) and hepatic triglyceride content (P=0.016 6) in the CGI-58 deficiency female mice. Mi-KD prevented microvesicular hepatic steatosis in the CGI-58 deficient female mice. Plin3 knockdown significantly reduced the triglyceride content in basal condition of hepatocytes (P=0.001 4), and Plin2 knockdown just showed a decreased trend. Plin2 or Plin3 knockdown significantly reduced the triglyceride content separately in lipid-overloaded hepatocytes (P < 0.05). Conclusion Hepatocyte Plin2 is essential in the development of microvesicular hepatic steatosis caused by CGI-58 deficiency. Both Plin2 and Plin3 are involved in lipid droplet formation and lipid accumulation in hepatocytes, and Plin3 shows a stronger effect.