Figure 5.

VPA elevates PDX1 expression and insulin secretion. (A) MIN6 and INS-1 cells were treated with increasing concentrations of VPA. Following 48 h treatment, PDX1 mRNA levels were analyzed by reverse transcription quantitative polymerase chain reaction analysis (*P<0.05 vs. 0 mM VPA). (B) SIRT5 was knocked down in MIN6 and INS-1 cells prior to treatment with 20 mM glucose and increasing concentrations of VPA for 48 h, and the level of insulin secretion was subsequently determined. Each experiment was repeated three times. The results are presented as the mean ± standard deviation (*P<0.05 vs. Vector). VPA, valproic acid; PDX1, pancreatic and duodenal homeobox 1; SIRT5, sirtuin 5; Vector, pcDNA3.1 plasmid vector.