Effects of Energy Levels on Autophagy, Adipogenic Differentiation and Lipid Metabolism in Subcutaneous and Visceral Pre-Adipocytes

This study aimed to investigate the differences in energy levels on autophagy, adipogenic differentiation and fat metabolism between subcutaneous and visceral pre-adipocytes. C57BL/6J male mouse primary subcutaneous and visceral pre-adipocytes were isolated and in-vitro adipogenic differentiation was performed in high-glucose medium (4500 mg/L glucose, HGM) or low-glucose medium (1000 mg/L glucose, LGM). Lipid contents in adipocytes were determined by oil red-O staining. Autophagy, adipogenic differentiation and fat metabolism were evaluated by western blot. Subcutaneous pre-adipocytes proliferation rate, differentiation degree and lipid accumulation were higher than that of visceral pre-adipocytes both in HGM and LGM. In HGM group, autophagy marker genes i.e., microtubule-associated protein 1A/1B-light chain 3 (LC-3) and lipolysis protein i.e., hormone-sensitive lipase (HSL) expression in visceral pre-adipocytes were higher than that in subcutaneous pre-adipocytes, but adipogenesis transcriptional factors such as sterol regulatory element-binding protein 1c (SREBP-1c) and peroxisome proliferator-activated receptor-gamma (PPAR-gamma) were lower than that in subcutaneous pre-adipocytes. Moreover, the LGM group increased the expressions of LC-3, reduced the p62 in both subcutaneous and visceral pre-adipocytes, and decreased the expression of the PPAR-gamma, SREBP-1c, and HSL. It is shown that triglyceride accumulation of pre-adipocytes in LGM was more than that of HGM. There were differences in autophagy, adipogenesis differentiation and lipolysis between subcutaneous and visceral pre-adipocytes in vitro. In addition, the low energy levels on the adipogenesis differentiation and lipid metabolism of subcutaneous pre-adipocytes were greater than that of visceral pre-adipocytes, but not the responses to autophagy.

Automated summary

This study aimed to investigate the differences in energy levels on autophagy, adipogenic differentiation and fat metabolism between subcutaneous and visceral pre-adipocytes. The results showed that subcutaneous pre-adipocytes had higher proliferation rate, differentiation degree, and lipid accumulation than visceral pre-adipocytes. In the high-glucose group, autophagy marker genes and lipolysis protein expression in visceral pre-adipocytes were higher than that in subcutaneous pre-adipocytes, but adipogenesis transcriptional factors were lower. The low-glucose group increased autophagy and reduced the expression of adipogenesis transcriptional factors and lipolysis protein in both subcutaneous and visceral pre-adipocytes.