Abstract: Objective To investigate the effect of P-glycoprotein overexpression on the differentiation of INS-1 cells and pancreatic β cells. Methods INS-1 cells were infected with adenovirus overexpressing P-glycoprotein. Ins2-abcb1b gene was randomly inserted into the rat islets, and P-glycoprotein overexpression model was successfully constructed. Empty adenovirus and wild-type SD rats were used as control groups. INS-1 cells and P-glycoprotein overexpression rats were used as experimental group. Total RNA was extracted both in INS-1 cells and rat islets. Transcription factors such as Abcb1b， Pdx1，Ins1，Ins2，Mafa，Mafb，Ngn3，Nkx6.1，Nkx2.2, Neurod1 and Pax6 were detected by real-time quantitative PCR. Results Compared with the control group，the transcription levels of Ngn3 and Mafb in INS-1 cells increased (P＜0.05), while Mafa decreased (P＜0.001). No significance was detected in other transcription factors. Unlike INS-1 cells, all of the transcription factors of islets were not affected (P＞0.05). Conclusion The overexpression of P-glycoprotein may dedifferentiate INS-1 cells, but has no effect on the differentiation of rat pancreatic beta cells.

Key words: P-glycoprotein, insulin-secreting cells, cell differentiation, diabetes mellitus, regeneration