Regulation Of Malonyl-CoA On Lipid Accumulation In Goat Intramuscular Adipocytes

Malonyl-CoA(Malonyl-CoA)is an essential substance in the body’s process of fatty acid synthesis.It is formed by carboxylation of acetyl-CoA under the action of Acetyl-CoA carboxylase(ACC),and decarboxylased by malonyl-CoA decarboxylase(MCD).Earlier studies believed that malonyl-CoA was only used as an intermediate product of fatty acid metabolism.Later,it was discovered that malonyl-CoA can also regulate fatty acid β oxidation by inhibiting carnitine palmityl transferase-1(CPT1).It can be seen that malonyl-CoA participates in the process of fatty acid synthesis and fatty acid oxidation at the same time.It is a regulatory link connecting the synthesis and oxidation of long-chain fatty acids,and is considered to be a molecular signal that regulates fat metabolism in animals.The molecular regulation mechanism of how malonyl-CoA regulates cell lipid metabolism is still unclear.Therefore,this study used exogenous malonyl-CoA to explore the effect of malonyl-CoA on lipid accumulation in goat intramuscular preadipocytes,and preliminarily studied the molecular mechanism of malonyl-CoA regulating cell lipid metabolism through transcriptome sequencing technology.The main findings are as follows:(1)Compared with the control group,20 μM,50 μM,100 μM,150 μM and 200μM malonyl-CoA significantly reduced the lipid droplet content in goat intramuscular preadipocytes(P<0.01).When the concentration of malonyl-CoA increased from 0μM to 50 μM,the lipid droplet content in the cells decreased rapidly and then stabilized.(2)3488 differential mRNAs were screened by transcriptome sequencing technology.GO analysis of differentially expressed mRNA found that after 20 μM malonyl-CoA treated cells,up-regulated differential genes were mainly enriched in items such as transcription regulation,transcription factor complex,RNA polymerase II cis-regulatory region sequence-specific DNA binding,etc.,and down-regulated genes are mainly enriched in entries such as translation,RNA polymerase III complex,and folded protein binding.After the cells were treated with 50 μM malonyl-CoA,upregulated differentially expressed genes were mainly enriched in entries such as translation,ribosomes,and ribosomal structural components;down-regulated genes were mainly enriched in entries such as sarcomere tissue,Z membrane,and actin binding.KEGG enrichment analysis of differential mRNA found that differentially expressed genes are mainly enriched in FoxO signaling pathway,PI3K-Akt signaling pathway,MAPK signaling pathway,etc.In addition,LIPG was predicted to play a role in intracellular lipid deposition under the regulation of malonyl-CoA in goat.(3)We successfully reduced the expression of CPT1A and CPT1B using RNA interference technology in goat intramuscular preadipocytes.CPT1A-siRNA-1 downregulated by 67.80%,CPT1A-siRNA-2 down-regulated by 64.11%;CPT1B-siRNA-1down-regulated by 59.19%,CPT1B-siRNA-2 down-regulated by 66.98%,indicating that CPT1A-siRNA-1 and CPT1B-siRNA-2 are on purpose the gene interference effect is better,reaching a very significant effect(P<0.01).Overexpression of CPT1A suing pcDNA3.1-CPT1A up-regulated by 83605 times,while using pcDNA3.1-CPT1B up-regulated by 45,331 times.CPT1A and CPT1B can play an independent role in the lipid accumulation process of goat preadipocytes,and it is speculated that the two can play a synergistic effectThe above results show that malonyl-CoA can affect lipid accumulation in goat intramuscular adipocytes,possibly by promoting the expression of LIPG gene,inhibiting the expression of fatty acid elongation and transport-related genes,and regulate the synergistic effect of CPT1A and CPT1B in the process of fatty acid βoxidation.This provides a reference for subsequent studies on the molecular mechanism of malonyl-CoA regulating lipid production in goat intramuscular preadipocytes.