High Glucose Induces β Cell De-differentiation Via Downregulation Of TCF7L2

Objective:To Investigate the role of β cell de-differentiation in high glucose induced β cell dysfunction.Methods:In this study, MIN6 cells were cultured and treated with different concentration of glucose for 48 h, which were divided into several groups, including control group(25mmol/L glucose) and different concentration of glucose groups(30,35,40mmol/L glucose). Transcription factor 7-like-2(TCF7L2) specific siRNA lentivirus vector( LV-TCF7L2-siRNA) was constructed with TCF7L2 mRNA coding sequence as the interference target. Empty vector virus was used to transfect the cells in control group. Glucose-stimulated insulin secretion(GSIS) method was used to assess the pancreatic function of MIN6 cells. Real-time PCR and western blot were performed to determine the mRNA and protein expression of progenitor like-cell marker genes, β cell marker genes and TCF7L2. Immunofluorescence was used to detect the expression of Nanog and Pdx-1 in MIN6 cells.Result:(1)The results showed that the expression of progenitor like-cell marker genes were significantly increased in 35mmol/L glucose group. Additionally, 35 mmol/L glucose treatment down-regulated the GSIS with reduced expression of β cell marker gene.(2)35 mmol/L glucose treatment also markedly decreased both the mRNA and protein expression of TCF7L2.(3)After down regulating the expression of TCF7L2 by TCF7L2 specific siRNA lentivirus vector, the GSIS was significantly inhibited accompanied by increased expression of progenitor like-cell marker genes and the decreased expression of β cell marker gene.Conclusion:High glucose induced β cell de-differentiation, which might be mediated by TCF7L2.