Regulation of Lipophagy on the Size of Lipid Droplets in Bovine Mammary Epithelial Cells
Lipophagy is a new form of autophagy,which can selectively recognize and degrade lipid droplets,and plays an important role in maintaining intracellular lipid homeostasis.The aim of this study was to investigate the effect of starvation induced lipophagy on the size of lipid droplets in bovine mammary epithelial cells.The cells were treated with 100 μmol·L-1 linoleic acid for 24 h to establish a lipid accumulation cell model,and then the cells were starved for 0,6,12,24,and 48 h,respectively.Oil red O staining was used to observe the changes in the size and number of intracellular lipid droplets with starvation time.Immunofluorescence was used to observe the co-localization of lipid droplets and autophagy protein LC3.Western blot was used to detect the expression of autophagy-related proteins LC3 and P62.The results showed that the diameter of lipid droplets significantly increased from 1.57 μm to 2.12 μm,the number of lipid droplets per cell significantly decreased from 39 to 24·cell-1,the proportion of large lipid droplets significantly increased,and the proportion of small lipid droplets significantly decreased with the extension of starvation treatment time(P＜0.05),immunofluorescence showed that LC3 co-localized with lipid droplets,and transmission electron microscopy showed that lipid droplets were encapsulated in autolysosomes.After 24 hours of starvation,the ratio of LC3 Ⅱ/LC3 Ⅰ protein increased by 1 fold,and the expression of P62 protein decreased significantly(P＜0.05).These results suggest that lipophagy plays a regulatory role in the size of lipid droplets in the bovine mammary epithelium.
万方数据
维普
