Role of autophagy in high glucose-induced podocyte lipid droplet accumulation / 中华肾脏病杂志

ABSTRACT

Objective To investigate the role of autophagy in high glucose-induced podocyte lipid droplet metabolism.Methods (1) Cultured,conditionally immortalized human podocytes (HPC)were divided into normal control group,high glucose group and mannitol group.Oil red O staining and oil red O staining extraction assay was used to observe the degree of lipid accumulation;Protein level of SREBP-1 was analyzed by Western blotting.(2) HPC were cultured and divided into normal control group,high glucose group,high glucose+3-methyladenine (3-MA) group,and mannitol group.Acridine orange staining was used to observe the formation of autophagosomes.Western blotting was used to detect the protein levels of beclin-1 and LC3-Ⅱ/LC3-Ⅰ.Oil red O staining and oil red O staining extraction assay was used to observe the degree of lipid accumulation;Western blotting was used to analyze the expression of SREBP-1.Results (1) Compared with the normal control group,the lipid accumulation in the high glucose group was increased and the lipid metabolism related molecule SREBP-1 was up-regulated (P ＜ 0.05);There was no significant difference between the normal control group and the mannitol group in lipid accumulation (P ＞ 0.05).(2) Compared with the normal group,the number of autophagosomes was increased and autophagy-related proteins beclin-1 and LC3-Ⅱ/LC3-Ⅰ were up-regulated in high glucose group (all P ＜ 0.05).After intervened with 3-methyladenine,a significant decrease in autophagosomes was observed;Protein levels of autophagy-related proteinsbeclin-1 and LC3-Ⅱ/LC3-Ⅰ were decreased (all P ＜ 0.05);The lipid droplets in the high glucose+3-MA group was decreased and lipid metabolism related molecule SREBP-1 was down-regulated (all P ＜0.05).Conclusion Autophagy may be involved in the process of high-glucose-induced podocyte lipid accumulation by affecting SREBP-1 expression,and inhibition of autophagy can alleviate the high-glucose-induced podocyte lipid accumulation.