Kim Narae, Minami Naojiro, Yamada Masayasu, Imai Hiroshi
Laboratory of Reproductive Biology Graduate School of Agriculture Kyoto University Kyoto Japan.
Reprod Med Biol. 2016 Dec 22;16(1):58-66. doi: 10.1002/rmb2.12011. eCollection 2017 Jan.
One of the parameters that greatly affects homeostasis in the body is the pH. Regarding reproductive biology, germ cells, such as oocytes or sperm, are exposed to severe changes in pH, resulting in dramatic changes in their characteristics. To date, the effect of the pH has not been investigated regarding the reprogramming of somatic cells and the maintenance and differentiation of pluripotent stem cells.
In order to investigate the effects of the pH on cell culture, the methods to produce induced pluripotent stem cells (iPSCs) and to differentiate embryonic stem cells (ESCs) into mesendoderm and neuroectoderm were performed at each medium pH from 6.6 to 7.8. Using the cells of the -GFP (green fluorescent protein) carrying mouse, the effects of pH changes were examined on the timing and colony formation at cell reprogramming and on the cell morphology and direction of the differentiation of the ESCs.
The colony formation rate and timing of the reprogramming of the somatic cells varied depending on the pH of the culture medium. In addition, mesendodermal differentiation of the mouse ESCs was enhanced at the high pH level of 7.8.
These results suggest that the pH in the culture medium is one of the key factors in the induction of the reprogramming of somatic cells and in the differentiation of pluripotent stem cells.
体内对稳态影响极大的参数之一是pH值。在生殖生物学领域，生殖细胞，如卵母细胞或精子，会暴露于pH值的剧烈变化中，导致其特性发生显著改变。迄今为止，尚未研究pH值对体细胞重编程以及多能干细胞的维持和分化的影响。
为了研究pH值对细胞培养的影响，在pH值从6.6至7.8的每种培养基中，进行了诱导多能干细胞（iPSC）的制备以及胚胎干细胞（ESC）向中胚层和神经外胚层分化的操作。使用携带绿色荧光蛋白（-GFP）的小鼠细胞，研究了pH值变化对细胞重编程时的时间和集落形成以及对ESC分化的细胞形态和方向的影响。
体细胞重编程的集落形成率和时间因培养基的pH值而异。此外，在pH值为7.8的高水平下，小鼠ESC的中胚层分化增强。
这些结果表明，培养基中的pH值是诱导体细胞重编程和多能干细胞分化的关键因素之一。
