Cdc42 Promotes ADSC-Derived IPC Induction, Proliferation, And Insulin Secretion Via Wnt/β-Catenin Signaling

Xing-Hua Xiao,* Qi-Yuan Huang,* Xian-Ling Qian,* Jing Duan, Xue-Qiao Jiao, Long-Yuan Wu, Qing-Yun Huang, Jun Li, Xing-Ning Lai, Yu-Bo Shi, Li-Xia Xiong Department of Pathophysiology, Medical College, Nanchang University, Nanchang 330006, People’s Republic of China*These authors contributed equally to this workCorrespondence: Li-Xia XiongDepartment of Pathophysiology, Medical College, Nanchang University, 461 Bayi Road, Nanchang 330006, People’s Republic of ChinaTel +86-791-8636-0556Email xionglixia@ncu.edu.cnPurpose: Type 1 diabetes mellitus (T1DM) is characterized by irreversible islet β cell destruction. Accumulative evidence indicated that Cdc42 and Wnt/β-catenin signaling both play a critical role in the pathogenesis and development of T1DM. Further, bio-molecular mechanisms in adipose-derived mesenchymal stem cells (ADSCs)-derived insulin-producing cells (IPCs) remain largely unknown. Our aim was to investigate the underlying mechanism of Cdc42/Wnt/β-catenin pathway in ADSC-derived IPCs, which may provide new insights into the therapeutic strategy for T1DM patients.Methods: ADSC induction was accomplished with DMSO under high-glucose condition. ML141 (Cdc42 inhibitor) and Wnt-3a (Wnt signaling activator) were administered to ADSCs from day 2 until the induction finished. Morphological changes were determined by an inverted microscope. Dithizone staining was employed to evaluate the induction of ADSC-derived IPCs. qPCR and Western blotting were employed to measure the mRNA and protein expression level of islet cell development-related genes and Wnt signaling-related genes. The proliferation ability of ADSC-derived IPCs was also detected with a cell counting kit (CCK) assay. The expression and secretion of Insulin were detected with immunofluorescence test and enzyme-linked immunosorbent assay (ELISA) respectively.Results: During induction, morphological characters of ADSCs changed into spindle and round shape, and formed islet-line cell clusters, with brown dithizone–stained cytoplasm. Expression levels of islet cell development-related genes were up-regulated in ADSC-derived IPCs. Wnt-3a promoted Wnt signaling markers and islet cell development-related gene expression at mRNA and protein levels, while ML141 played a negative effect. Wnt-3a promoted ADSC-derived IPC proliferation and glucose-stimulated insulin secretion (GSIS), while ML141 played a negative effect.Conclusion: Our research demonstrated that DMSO and high-glucose condition can induce ADSCs into IPCs, and Wnt signaling promotes the induction. Cdc42 may promote IPC induction, IPC proliferation and insulin secretion via Wnt/β-catenin pathway, meaning that Cdc42 may be regarded as a potential target in the treatment of T1DM.Keywords: Cdc42, ML141, ADSCs, IPCs, Wnt signaling, insulin