The Effects Of MafA Gene Interfered By SiRNA On The Proliferation Of The Pancreatic β-cells And The Expression Of Insulin Gene Of The Mouse

Objective(1) The best siRNA was selected to interfere with MafA mRNA.(2)Toinvestigate the effect of MafA on the expression of insulin gene and the proliferationof the pancreatic β-cell of mouse.(3)The relation was explored between MafA andFoxO1protein.Methods(1)MIN6cells were infected with siRNA, then the expression of MafAmRNA was detected by the method of Real Time PCR and the expression of MafAprotein by the method of Western blot.(2)The proliferation of MIN6cells, infectedwith siRNA in different concentrations of glucose, was measured by the method ofMTT. The expressions of FoxO1,PDX-1,insulin1and insulin2mRNA in MIN6cellsinfected with siRNA in different concentration of glucose were assayed by the methodof Real Time PCR.(4)The expression of MafA,FoxO1and PDX-1proteins in MIN6cells, infected with siRNA in different concentration of glucose, were detected by themethod of Western blot.Results (1) The expression of MafA mRNA and the level of its protein in groupsiMafA-2were significantly decreased compared with the group Cy3. It was suggested thatthe siRNA in group siMafA-2could interfered more effectively with MafA.(2)Theproliferation of MIN6cells was significantly decreased in the group with siRNAcompared with the control group in different concentrations of glucose.(3)The expressionof FoxO1mRNA in the siRNA group was remarkably lower than that in the controlgroup in25mM glucose.(4)The expressions of MafA, FoxO1and PDX-1proteins weresignificantly decreased in the siRNA group compared with the control group in25mMglucose. Compared with the control group in2.5mM glucose, the expressions of FoxO1and PDX-1proteins were remarkably increased in the siRNA group, and there was nosignificant difference in the expression of MafA protein between the two groups.(5)The expression of insulin2mRNA in the siRNA group was significantly lower than that in the control group in25mM glucose, while insulin2mRNA had no significantchange in2.5mM glucose. The expression of insulin1mRNA was not changed in thesiRNA group compared with the control group in different concentrations of glucose.Conclusion (1) The siRNA in siMafA-2group was the best effective siRNAwhich could make MafA expression decreased significantly.(2) Down-regulation ofMafA could inhibit the proliferation of the mouse Pancreatic β cells.(3)Down-regulation of MafA could directly inhibit the insulin2mRNA expression andindirectly do it through decreasing FoxO1and PDX-1.(4) MafA could regulate theexpression of FoxO1and PDX-1.