Generation of insulin-secreting β cells in vitro is a promising approach for diabetes cell therapy. Human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs) are differentiated to β cells (SC-β cells) and mature to undergo glucose-stimulated insulin secretion, but molecular regulation of this defining β cell phenotype is unknown. Here, we show that maturation of SC-β cells is regulated by the transcription factor SIX2. Knockdown (KD) or knockout (KO) of SIX2 in SC-β cells drastically limits glucose-stimulated insulin secretion in both static and dynamic assays, along with the upstream processes of cytoplasmic calcium flux and mitochondrial respiration. Furthermore, SIX2 regulates the expression of genes associated with these key β cell processes, and its expression is restricted to endocrine cells. Our results demonstrate that expression of SIX2 influences the generation of human SC-β cells in vitro.

体外分泌胰岛素分泌的β细胞是用于糖尿病细胞治疗的有前途的方法。人类胚胎干细胞（hESCs）和人类诱导性多能干细胞（hiPSCs）分化为β细胞（SC-β细胞）并成熟以经历葡萄糖刺激的胰岛素分泌，但是这种定义β细胞表型的分子调控尚不清楚。在这里，我们显示出SC-β细胞的成熟受转录因子SIX2调控。SIX2的组合式（KD）或组合式（KO）在静态和动态测定中，SC-β细胞中的α-β-内啡肽都极大地限制了葡萄糖刺激的胰岛素分泌，以及细胞质钙通量和线粒体呼吸的上游过程。此外，SIX2调节与这些关键β细胞过程相关的基因的表达，并且其表达仅限于内分泌细胞。我们的结果证明SIX2的表达影响体外人SC-β细胞的生成。