Men1 Gene Regulates The Lipid Metabolism And Inflammatory Reaction Of Mouse Hepatocytes

In the dairy industry,the natural incidence of fatty liver syndrome is generally high,it has brought great economic loss,the prevention and/or treatment of fatty liver syndrome has become the goal of animal breeders.Studies have shown that menin is a key factor in regulating liver lipid metabolism,and directly interacts with transciption factors or indirectly regulates the liver lipid metabolism.Men1 is mainly inductive multiple endocrine neoplasia type 1 in human.Menin is encoded by Men1 gene that not only can interact with many important transcription factors,also join different intracellular signaling pathways and widely regulate the metabolism.Studies have shown that Men1-hemizygous deletion of mice showed the increased body weight,higher levels of insulin and glucagon in serum,increased triglycerides in the liver,adipose degenerationThe related genes,such as uncoupling protein 2(Ucp2)peroxisome proliferator-activated receptor gamma coactivator 1(Pgc-1?)and glucokinase(GK)were further indicated up-regulated in expression.In this study,as an important candidate gene for liver metabolism,the Men1 gene was investigated for its roles in lipid metabolism,glucose metabolism,insulin response and/or inflammatory response.PI3K/Akt,AMPK and NF-?B signaling pathways are important signaling pathways regulating glucose metabolism,lipid metabolism and inflammatory response.Thus,studying the gene expression of factors involved in these signal pathways is important to reveal its regulation role in liver metabolism.The Recombinant plasmid pcDNA3.1-Myc-His-mMen1 was successfully constructed and transiently transfected into the model of mouse normal liver cell line NCTC-1469 for Men1 gene overexpression experiments;RNAi method was used to transfect Men1 si RNA in the Men1 gene inhibition system.The expression of Men1 gene was detected by qRT-PCR,and the RNA samples were sequenced.The mouse liver cells were treated with insulin and glucose to verify and study Men1 for fat metabolism,inflammatory response regulation.The results show that:(1)The recombinant plasmid pcDNA3.1-Myc-His-m Men1 was successfully expressedin NCTC-1469 cells and the expression of Men1 gene at mRNA level was significantly increased(P<0.01);NCTC-1469 transfected with siMEN-2 and we found that the expression level of Men1 m RNA was significantly decreased at 48 h after transfection(P <0.01).(2)RNA samples were extracted for transcriptome sequencing.Overexpression of Men1 resulted in upregulation of 32 differentially expressed genes,Low expression of Men1 resulted in 157 differentially expressed genes(the number of up-regulation of DEGs is 51;the number of down-regulation of DEGs is 106).By GO analysis and KEGG analysis,the insulin-related signal pathway,glucose metabolism,fatty acid metabolic pathway,inflammatory pathway and some of the interaction proteins were screened.(3)In the treatment of 6 ?g / mL insulin at 8 h and 35 mmol / L glucose at 48 h respectively.It was found that both of them could down-regulate the expression of Men1gene(P<0.01),which indicated that Men1 gene was involved in glucose and insulin-mediated lipid synthesis and inflammatory response.Then,the data of the transcripts were screened with lipid metabolism,glucose metabolism,insulin reaction.The results showed that the addition of glucose and insulin could upregulate the mRNA expression the genes,for example,Pgc-1?,Srebp-1c,Fas,Acc1,and Akt involving the lipid synthesis,While reduce the mRNA expression of Ampk,Nf-?b,Il-1b,Tnf-? inflammatory.In conclusion,Men1 gene can regulate the fat metabolism and inflammatory response in mouse hepatocytes through PI3 K / Akt signaling pathway,AMPK signal pathway and/orNF-?B signaling pathway,indicating that menin is a key factor regulating the lipid metabolism in the mouse liver.The study would provide important fundamentals for the further investigations of Men1/menin in the regulation of fat metabolism in other species.