The Study On Transcription Regulation Of FGF21 Gene And DsbA-L Gene

Objective:Fibroblast growth factor 21(FGF21)is a metabolic hormone with multiple beneficial effects on lipid and glucose homeostasis.Recent studies reported that FGF21 can up-regulate the expression of DsbA-L.As a key regulation protein involved in adiponectin multimerization,DsbA-L has some beneficial effects including increasing insulin sensitivity and energy expenditure.FGF21 and DsbA-L have some connections in promoting the expression of Adiponecin.This study aimed to analyze the transcription regulation of FGF21 and DsbA-L.Methods:We generated a series of luciferase reporter gene constructs containing the promoter sequence of the mouse FGF21 gene and human DsbA-L gene respectively.Online software(MAPPER)was uesd to predict the potencial transcription factor bingding sites.Related experiments were carried out to investigate the effect of key transcriptional factors on promoter activity.We also demonstrated the functions of related transcriptional factors in the adipose of the obeses.Results:Our study demonstrated that the proximal promoter of mouse FGF21 is located between-63 and-20 bp relative to the TSS.In sillico analysis revealed two putative Sp1-binding sites within the proximal promoter.Mutation analysis demonstrated that the Sp1-binding site located between-46 to-38 plays a primary role in transcription regulation of FGF21.EMSA and ChIP analysis indicated that Sp1 specifically bound to the promoter region of FGF21.The binding activity of Sp1 was significantly increased in adipose tissues of diet-induced obesity mice.In our study,the promoter of human Disulfide-bond-A oxidoreductase-like protein was successfully cloned.Deletion analysis of the promoter revealed that the key transcriptional region was located between-2114 to-1228.MAPPER predict several potential transcriptional factors related to the differentiation and development of fat.Comparing the expression levels of these transcription factors in the adipose tissue of the obese and non-obese people,we found that NF-?B and FOXO1 are upregulated in obese people,implying that NF-?B and FOXO1 are the upstream repressor.Conclusion:1 The first part of our study demonstrated that Sp1 can positively regulates the basal transcription of FGF21 and may provide a mechanism underlying the obesityinduced FGF21 upregulation in adipose tissue of HFD induced obese mice.2 In the second part,the promoter of human Disulfide-bond-A oxidoreductase-like Protein was analyzed preliminary.And we speculated the key upstream repressor.