Rönkkö Julius, Rodriguez Yago, Rasila Tiina, Torregrosa-Muñumer Rubén, Pennonen Jana, Kvist Jouni, Kuuluvainen Emilia, Bosch Ludo Van Den, Hietakangas Ville, Bultynck Geert, Tyynismaa Henna, Ylikallio Emil
Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, 00290, Finland.
Molecular and Integrative Bioscience Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, 00790, Finland; Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, 00790, Finland.
Cell Calcium. 2023 Sep;114:102782. doi: 10.1016/j.ceca.2023.102782. Epub 2023 Jul 17.
Inositol 1,4,5-trisphosphate receptors (IPRs) are ER Ca-release channels that control a broad set of cellular processes. Animal models lacking IPRs in different combinations display severe developmental phenotypes. Given the importance of IPRs in human diseases, we investigated their role in human induced pluripotent stem cells (hiPSC) by developing single IPR and triple IPR knockouts (TKO). Genome edited TKO-hiPSC lacking all three IPR isoforms, IPR1, IPR2, IPR3, failed to generate Ca signals in response to agonists activating GPCRs, but retained stemness and pluripotency. Steady state metabolite profiling and flux analysis of TKO-hiPSC indicated distinct alterations in tricarboxylic acid cycle metabolites consistent with a deficiency in their pyruvate utilization via pyruvate dehydrogenase, shifting towards pyruvate carboxylase pathway. These results demonstrate that IPRs are not essential for hiPSC identity and pluripotency but regulate mitochondrial metabolism. This set of knockout hiPSC is a valuable resource for investigating IPRs in human cell types of interest.
肌醇1,4,5 -三磷酸受体（IPRs）是内质网钙释放通道，可控制一系列广泛的细胞过程。缺乏不同组合IPRs的动物模型表现出严重的发育表型。鉴于IPRs在人类疾病中的重要性，我们通过构建单IPR和三IPR基因敲除（TKO）的人类诱导多能干细胞（hiPSC）来研究它们在hiPSC中的作用。基因编辑的TKO - hiPSC缺乏所有三种IPR亚型，即IPR1、IPR2、IPR3，在响应激活GPCR的激动剂时无法产生钙信号，但保留了干性和多能性。TKO - hiPSC的稳态代谢物谱分析和通量分析表明，三羧酸循环代谢物存在明显改变，这与它们通过丙酮酸脱氢酶利用丙酮酸的能力不足一致，转而倾向于丙酮酸羧化酶途径。这些结果表明，IPRs对hiPSC的特性和多能性并非必不可少，但可调节线粒体代谢。这组基因敲除的hiPSC是研究感兴趣的人类细胞类型中IPRs的宝贵资源。
