Data_Sheet_1_miR-212/132-Enriched Extracellular Vesicles Promote Differentiation of Induced Pluripotent Stem Cells Into Pancreatic Beta Cells.PDF

Pancreatic beta cell transplantation is the ideal method for treatment of type 1 diabetes mellitus (T1DM), and the generation of beta cells from induced pluripotent stem cells (iPSCs) of patients is a promising strategy. In this study, we improved a previous strategy to produce beta cells using extracellular vesicles (EVs) derived from mature beta cells and differentiated beta cells from iPSCs (i-Beta cells), which secreted insulin under glucose stimulation in vitro and ameliorated hyperglycemia in vivo. Mechanistic analyses revealed that EV-carried microRNA (miR)-212/132 (EV-miR-212/132) directly bound to the 3′ UTR of FBW7 to prevent its translation and FBW7 combined with NGN3 to accelerate its proteasomal degradation. EV-miR-212/132 stabilized NGN3 expression to promote differentiation of endocrine cells from induced iPSCs. Moreover, NGN3 bound to PDX1 to enhance transcription of endogenous miR-212/132 and formed a positive regulatory circuit that maintained the functions of mature pancreatic beta cells.
ConclusionThis study describes a novel approach for beta cell production and supports the use of iPSCs for cell replacement therapy of T1DM.

胰腺β细胞移植是治疗1型糖尿病（type 1 diabetes mellitus, T1DM）的理想手段，而从患者诱导多能干细胞（induced pluripotent stem cells, iPSCs）中获取β细胞是极具临床转化前景的治疗策略。本研究对既往利用成熟β细胞来源的细胞外囊泡（extracellular vesicles, EVs）制备β细胞的方案进行了优化，成功从iPSCs中分化得到β细胞（以下简称i-β细胞），该细胞在体外可响应葡萄糖刺激分泌胰岛素，并在体内有效改善高血糖状态。机制分析显示，细胞外囊泡携带的微小RNA（microRNA, miR）-212/132（EV-miR-212/132）可直接结合FBW7的3'非翻译区（3' UTR），阻断其翻译过程；同时FBW7可与NGN3结合，加速后者的蛋白酶体降解。EV-miR-212/132通过稳定NGN3的表达水平，促进诱导多能干细胞向内分泌细胞分化。此外，NGN3可结合PDX1，增强内源性miR-212/132的转录活性，形成一套维持成熟胰腺β细胞功能的正反馈调控环路。结论：本研究提出了一种制备β细胞的全新方法，为利用iPSCs开展1型糖尿病的细胞替代治疗提供了坚实的理论支持。