The Role Of LncINF4 In Porcine Intramuscular Preadipocytes Proliferation,Differentiation And Autophagy

Muscle and fat are the two main factors determining the quality of pork.Intramuscular fat is an important aspect affecting the fat content in muscle tissue.Therefore,exploring the regulation mechanism of intramuscular fat deposition is of great significance to improve pork quality.Long noncoding RNA(lncRNA)is a kind of non-coding RNA produced by the body and participates in many life activities,including cell proliferation and differentiation.Current research indicates that lncRNAs participate in the differentiation of adipocytes in many ways,and less research on intramuscular fat deposition in pigs.In this study,intramuscular adipocytes were isolated from the longissimus dorsi muscle of fat-type Bamei pigs and lean-type Large white pigs.After differentiation in vitro for 0,2,4 and 8 days,they were sequenced and screened in pigs.The effects of lncIMF4 were studied on intramuscular fat deposition in this study.Firstly,in this study,two different types of pig breeds and intramuscular adipocytes in different differentiation stages were sequenced,and some differentially expressed lncRNAs were screened.Secondly,lncIMF4 was selected as a research object by bioinformatics analysis.Then,we synthesised and transfected the lncIMF4 siRNA,and the effects of lncIMF4 on the proliferation of porcine intramuscular adipocytes detected by EDU,CCK-8 and flow cytometry.And the effects of lncIMF4 on cell differentiation were explored by using oil red O and Bodipy staining.Finally,this study constructed a model of autophagy in pig intramuscular adipocytes,studied the effect of lncIMF4 on autophagy in porcine intramuscular adipocytes,and found that lncIMF4 participates in the regulation of intramuscular adipocytes lipolysis by autophagy.The main findings obtained are as follows:1.There are many differentially expressed lncRNAs in the intramuscular fat of Bamei pigs and Large white pigs;lncIMF4 expression level increased first and then decreased during the differentiation of intramuscular adipocytes,and was expressed at the 2 day of differentiation at the highest amount;lncIMF4 has a certain expression level in pig tissues and a high expression in adipose tissue;lncIMF4 is distributed in the nucleus and cytoplasm of pig intramuscular fat cells,mainly located in the nucleus;2.Interference with lncIMF4 promoted the expression of mRNA and protein of CyclinD and CyclinE in the proliferative phase of pig intramuscular progenitor adipocytes,indicatied that lncIMF4 is involved in promoting the proliferation of intramuscular fat cells;3.Interference with lncIMF4 promoted the expression of mRNA and protein of PPAR? and CEBP? in pig intramuscular adipocytes differentiation,and oil red O staining showed increased lipid droplets,indicatied that lncIMF4 interfered with the differentiation of intramuscular adipocytes;4.Interference lncIMF4 down-regulated the expression of autophagy-related gene mRNA and protein in porcine intramuscular precursor adipocytes,and found that interferenced with lncIMF4 inhibited lipolysis by autophagy.In summary,lncIMF4 was differentially expressed in the process of adipogenic fat cells of pigs;interference lncIMF4 promoted the proliferation and differentiation of porcine intramuscular precursor adipocytes and inhibit autophagy of intramuscular adipocytes.This study screened lncIMF4 participated in the regulation of proliferation,differentiation and autophagy of pig intramuscular precursor fat cells.The results provide reference and reference for lncRNAs to regulate intramuscular fat deposition in pigs.