Sugimoto Kouji, Matsuura Takashi, Nakazono Ayako, Igawa Kazunari, Yamada Shizuka, Hayashi Yoshihiko
Department of Cariology, Nagasaki University Graduate School of Biomedical Sciences, Sakamoto 1-7-1, Nagasaki 852-8588, Japan.
Microsc Res Tech. 2018 Jul;81(7):749-754. doi: 10.1002/jemt.23032. Epub 2018 Apr 6.
A hypoxic condition is known to contribute to pluripotency. In the present article, the effects of transcription factors were first assessed regarding the proliferation and differentiation of human induced pluripotent stem (iPS) cells under hypoxic conditions using cell morphology and real-time polymerase chain reaction (RT-PCR). Morphology evaluations and RT-PCR revealed that the colony formation was promoted and the expression of pluripotent markers was increased under hypoxic conditions. In addition, the function of hypoxia inducible factors (HIFs) in human iPS cells under hypoxic conditions was evaluated in relation to the morphology and the expression of pluripotency markers by siRNA and RT-PCR. The HIF-2α silencing group showed a reduction in the colony size of human iPS cells and a statistically significant reduction in the expression of undifferentiation markers compared to the control group. Furthermore, the expression of HIF-2α was decreased when signal transducer and activator of transcription 3 (STAT3) was suppressed by its inhibitor, Stattic or S31 201. The inhibition using Stattic did not produce colony formation. The expression of pluripotent markers was also decreased using Stattic or S31 201. This study indicates that the HIF-2α expression in human iPS cells was activated under hypoxic conditions, similarly to that in murine iPS cells, and that HIF-2α among HIFs is the most effective compound for maintaining the pluripotency of human iPS cells. Furthermore, the STAT3 signal pathway regulates the expression of HIF-2α.
已知低氧条件有助于多能性。在本文中，首先使用细胞形态学和实时聚合酶链反应（RT-PCR）评估了转录因子在低氧条件下对人诱导多能干细胞（iPS细胞）增殖和分化的影响。形态学评估和RT-PCR显示，在低氧条件下集落形成得到促进，多能性标志物的表达增加。此外，通过小干扰RNA（siRNA）和RT-PCR，评估了低氧条件下人iPS细胞中低氧诱导因子（HIFs）的功能与形态学和多能性标志物表达的关系。与对照组相比，HIF-2α沉默组显示人iPS细胞的集落大小减小，未分化标志物的表达有统计学意义的降低。此外，当信号转导子和转录激活子3（STAT3）被其抑制剂Stattic或S31 201抑制时，HIF-2α的表达降低。使用Stattic进行抑制未产生集落形成。使用Stattic或S31 201时多能性标志物的表达也降低。本研究表明，与小鼠iPS细胞类似，人iPS细胞中的HIF-2α表达在低氧条件下被激活，并且在HIFs中，HIF-2α是维持人iPS细胞多能性最有效的化合物。此外，STAT3信号通路调节HIF-2α的表达。
