Role Of Autophagy In High Glucose-induced Lipid Droplet Accumulation In Podocyte

Objective To investigate the change of lipid accumulation and autophagy level of conditionally immortalized human podocytes,and to explore role of autophagy in high glucose-induced podocyte lipid droplet metabolism.Methods Conditionally immortalized human podocytes were divided into normal,high glucose and mannitol groups;oil red O staining and oil red O staining extraction assay was used to observe the degree of lipid accumulation;Expression of SREBP-1 was analyzed by Western blot.HPC were cultured and divided into normal,high glucose,high glucose+3-Methyladenine(3-MA),and mannitol groups.Acridine orange staining was used to observe the formation of autophagsomes.Western Blot was used to detect the protein levels of beclin-1 and LC3-Ⅱ/LC3-Ⅰ.Western blot was used to analyze expression of SREBP-1.Oil red O staining and oil red O staining extraction assay was used to observe the degree of lipid accumulation.Results There was no significant difference between the normal and the mannitol groups in lipid accumulation;Compared with the normal 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).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(P<0.05).After intervention with 3-methyladenine,a significant decrease in autophagosomes was observed;Protein levels of autophagy-related proteins beclin-1 and LC3-Ⅱ/LC3-Ⅰ were decreased(P<0.05);Lipid metabolism related molecule SREBP-1 was down-regulated and lipid droplets in the high glucose+3-MA group was decreased(P<0.05).Conclusion High glucose stimulation can lead to increased lipid accumulation in podocytes and up-regulation of lipid metabolism-related molecule SREBP-1.Inhibition of autophagy on the basis of high glucose stimulation can down-regulate the expression of SREBP-1 in podocytes and alleviate lipid accumulation;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.