The Mechanism And The Effect Of GDF-15 On Adipogenesis In MSC

Background:Obesity has become a global public health problem.Obesity increases the incidence of many diseases including cardiovascular diseases,type 2 diabetes,hypertension,and cancer.Obesity is a common chronic metabolic disease,mainly in the pathological manifestations of the increase of fat cells or the increase of adipocytes.The differentiation of mesenchymal stem cells and adipose precursor cells is the basis for the formation of adipocytes.Recent studies have shown that growth differentiation factor-15(GDF-15)is closely related to metabolic-related cardiovascular disease and diabetes.It remains unclear whether GDF-15 regulates the differentiation of adipocytes.Objective: 1.To detect the expression characteristics of GDF-15 in adipose tissue of hypertensive rats and normal rats by gene sequencing;2.To study the effect of GDF-15 on adipogenic differentiation of mesenchymal stem cells and explore its regulation in order to explore potential new targets for clinical treatments in obesity.Methods: 1.Isolating human primary mesenchymal stem cells and rat primary mesenchymal stem cells divided from retroperitoneal.Using classical "cocktail" program: insulin,dexamethasone,rosiglitazone(with the exception of 3T3-L1 cells),3-Isobutyl-1-Methylxanthine(IBMX)to induce the differentiation of preadipocytes into mature adipocytes;2.Mesenchymal stem cells were treated with inhibitor of GDF-15(Isoniazid,INH)before differentiation.After differentiated into mature adipocytes in vitro.Adipogenesis as confirmed by oil red O staining,cholesterol、triacylglycerol content;3 The expression levels of key genes(PPARγ,C/EBP-α,Fas,ACC,FABP4)were detected by Western Blotting.Results: 1.Gene sequencing revealed that the expression of GDF-15 in the fat of SHR rats was more than four times that of WKY rats.2.INH significantly reduced the expression of GDF-15 in mesenchymal stem cells.3 After inhibiting GDF-15,the differentiation of mesenchymal stem cells was significantly reduced,and the markers of adipogenesis such as ACC,fas,fabp4,and AP all decreased significantly compared with the control group,and the synthesis of triglycerides and cholesterol significantly reduced.4.After inhibiting GDF-15,the expression of PPARγ and C/EBP-α proteins were significantly decreased,but the adipogenesis decreasing of mesenchymal stem cells by inhibiting GDF-15 was reversed after activating PPARγ pathway with PPARγ agonists.Expression of adipogenesis markers such as Fas,Fabp4,and AP was upregulated.Conclusion: 1.GDF-15 was highly expressed in SHR rats and was lowly expressed in WKY rats;2.Inhibition of GDF-15 decreased adipogenesis of mesenchymal stem cells through PPAR-γ pathway.