Section of Islet Cell Biology and Regenerative Medicine, Joslin Diabetes Center and Harvard Medical School, Boston, MA, 02215, USA; Division of Endocrinology, Department of Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA, 02115, USA.
Section of Islet Cell Biology and Regenerative Medicine, Joslin Diabetes Center and Harvard Medical School, Boston, MA, 02215, USA.
Mol Metab. 2021 May;47:101164. doi: 10.1016/j.molmet.2021.101164. Epub 2021 Jan 14.
The insulin and insulin-like growth factor-1 (IGF-1) receptors are important for the growth and development of embryonic tissues. To directly define their roles in the maintenance of pluripotency and differentiation of stem cells, we knocked out both receptors in induced pluripotent stem cells (iPSCs). iPSCs lacking both insulin and IGF-1 receptors (double knockout, DKO) exhibited preserved pluripotency potential despite decreased expression of transcription factors Lin28a and Tbx3 compared to control iPSCs. While embryoid body and teratoma assays revealed an intact ability of DKO iPSCs to form all three germ layers, the latter were composed of primitive neuroectodermal tumor-like cells in the DKO group. RNA-seq analyses of control vs DKO iPSCs revealed differential regulation of pluripotency, developmental, E2F1, and apoptosis pathways. Signaling analyses pointed to downregulation of the AKT/mTOR pathway and upregulation of the STAT3 pathway in DKO iPSCs in the basal state and following stimulation with insulin/IGF-1. Directed differentiation toward the three lineages was dysregulated in DKO iPSCs, with significant downregulation of key markers (Cebpα, Fas, Pparγ, and Fsp27) in adipocytes and transcription factors (Ngn3, Isl1, Pax6, and Neurod1) in pancreatic endocrine progenitors. Furthermore, differentiated pancreatic endocrine progenitor cells from DKO iPSCs showed increased apoptosis. We conclude that insulin and insulin-like growth factor-1 receptors are indispensable for normal lineage development and perturbations in the function and signaling of these receptors leads to upregulation of alternative compensatory pathways to maintain pluripotency.
胰岛素和胰岛素样生长因子-1（IGF-1）受体对于胚胎组织的生长和发育非常重要。为了直接确定它们在维持多能性和干细胞分化中的作用，我们在诱导多能干细胞（iPSC）中敲除了这两个受体。与对照 iPSC 相比，缺乏胰岛素和 IGF-1 受体的 iPSC（双敲除，DKO）表现出保留的多能性潜力，尽管转录因子 Lin28a 和 Tbx3 的表达降低。虽然胚状体和畸胎瘤试验显示 DKO iPSC 具有形成所有三个胚层的完整能力，但后者在 DKO 组中由原始神经外胚层肿瘤样细胞组成。对照与 DKO iPSC 的 RNA-seq 分析显示，多能性、发育、E2F1 和细胞凋亡途径的调控存在差异。信号转导分析表明，在基础状态和用胰岛素/IGF-1 刺激后，DKO iPSC 中的 AKT/mTOR 途径下调，STAT3 途径上调。DKO iPSC 的定向分化受到干扰，脂肪细胞中关键标记物（Cebpα、Fas、Pparγ 和 Fsp27）和胰腺内分泌祖细胞中转录因子（Ngn3、Isl1、Pax6 和 Neurod1）的表达显著下调。此外，来自 DKO iPSC 的分化的胰腺内分泌祖细胞显示出增加的细胞凋亡。我们得出结论，胰岛素和胰岛素样生长因子-1 受体对于正常的谱系发育是不可或缺的，这些受体的功能和信号转导的改变导致替代性补偿途径的上调，以维持多能性。
