Analysis And Identification Of Differential Expression Of Lipid Droplet Surface Proteins In Skeletal Muscle And Adipose Tissue Cells

Lipid droplets are distributed in individual cells as an organelle,controlling the storage and turnover of neutral lipids.However,with the further study of lipid droplets,we found that the lipid droplet size varies and the function is different in different tissues.For example,in white adipose tissue cells,lipid droplets are in the form of a single-chamber fat droplet.The main function is as a storage warehouse for energy;in brown adipose tissue cells,there are multiple small lipid droplets,the main function is to generate energy;in skeletal muscle cells,lipid droplets are arranged according to the regular distribution of muscle fibers,mainly the function is also to provide energy.Lipid droplet surface proteins are the basis of their biological functions.Studies have shown that hundreds of lipid droplets related proteins have been identified by Label free proteomics technology,and lipid droplets surface proteins determine fat metabolism and thus affect the function and size of lipid droplets.Therefore,the analysis of different tissue lipoprotein group differences is conducive to further analysis of the heterogeneity of lipid droplets,in order to provide material for animal meat quality improvement.For this reason,we used DIA proteomics to analyze lipid droplet surface proteins in white adipose tissue,brown adipose tissue,and skeletal muscle cells.The main findings are as follows:1.A total of 2833 lipid droplet related proteins were identified in white adipose tissue,brown adipose tissue and skeletal muscle by the DIA proteome.Proteins on lipid droplets were found to be associated with redox and catalytic processes,in which brown adipose tissue and skeletal muscle contain large amounts of mitochondria-associated proteins.2.In the lipid surface proteins of white adipose tissue,we screened metabolically related active enzymes such as FMO2,CYP2E1,GSTA3,etc.,which may be involved in the formation of single-compartment large lipid droplets in white adipose tissue;white adipose tissue was also found 211 proteins specific to the surface of lipid droplets,such as VTILB,SLC2A3,UGT1A6 B,etc.3.There are a large number of mitochondria-associated proteins and fatty acid oxidation-related proteins SLC25A20,HADHB,ACAA2 on the lipid droplets of brown adipose tissue.GLUL,FASN,PDHB,TKT,and DECR1 may play important roles in lipid deposition in brown adipose tissue.4.The surface protein of lipid droplets in skeletal muscle is associated with muscle development regeneration,creatine kinase isoenzyme and mitochondria.We believe that PLA2G7 and GPCPD1 proteins specific to lipid droplet surface in skeletal muscle may play an important role in lipid metabolism in muscle.It is mainly regulated by a pathway related to phospholipid metabolism.The above results indicate that the surface protein of lipid droplets determines the function of lipid metabolism and lipid droplets in cells.The surface of lipid droplets in white adipose tissue is rich in nutrient metabolism related proteins and catalytic absorption efficiency proteins;the surface of lipid droplets in brown adipose tissue is rich in fatty acids.Metabolism and energy-related proteins;the surface of lipid droplets in skeletal muscle is rich in various lipid-degradation pathway-related proteins.