Clinical Medicine Division, Korea Institute of Oriental Medicine, Daejeon 34054, Korea.
Herbal Medicine Research Division, Korea Institute of Oriental Medicine, Daejeon 34054, Korea.
Nutrients. 2020 Mar 9;12(3):721. doi: 10.3390/nu12030721.
Induced pluripotent stem cells (iPSCs) have similar properties to embryonic stem cells in terms of indefinite self-renewal and differentiation capacity. After in vitro differentiation of iPSCs, undifferentiated iPSCs (USCs) may exist in cell therapy material and can form teratomas after in vivo transplantation. Selective elimination of residual USCs is, therefore, very important. Prunellae Spica (PS) is a traditional medicinal plant that has been shown to exert anti-cancer, antioxidant, and anti-inflammatory activities; however, its effects on iPSCs have not been previously characterized. In this study, we find that ethanol extract of PS (EPS) effectively induces apoptotic cell death of USCs through G2/M cell cycle arrest, generation of intracellular reactive oxygen species, alteration of mitochondrial membrane potentials, and caspase activation of USCs. In addition, EPS increases p53 accumulation and expression of its downstream targets. In p53 knockout (KO) iPSCs, the EPS did not induce apoptosis, indicating that EPS-mediated apoptosis of USCs was p53-dependent. In addition, EPS was not genotoxic towards iPSCs-derived differentiated cells. EPS treatment before injection efficiently prevented in ovo teratoma formation of p53 wild-type (WT) iPSCs but not p53KO iPSCs. Collectively, these results indicate that EPS has potent anti-teratoma activity and no genotoxicity to differentiated cells. It can, therefore, be used in the development of safe and efficient iPSC-based cell therapies.
诱导多能干细胞（iPSCs）在无限自我更新和分化能力方面与胚胎干细胞具有相似的特性。iPSCs 体外分化后，未分化的 iPSCs（USCs）可能存在于细胞治疗材料中，并在体内移植后形成畸胎瘤。因此，选择性消除残留的 USCs 非常重要。夏枯草（PS）是一种传统的药用植物，已被证明具有抗癌、抗氧化和抗炎作用；然而，其对 iPSCs 的影响尚未得到表征。在这项研究中，我们发现 PS 的乙醇提取物（EPS）通过 G2/M 细胞周期阻滞、细胞内活性氧的产生、线粒体膜电位的改变和 USCs 中半胱天冬酶的激活，有效地诱导 USCs 的凋亡性细胞死亡。此外，EPS 增加了 p53 的积累和其下游靶标的表达。在 p53 敲除（KO）iPSCs 中，EPS 不会诱导细胞凋亡，表明 EPS 介导的 USCs 凋亡是 p53 依赖性的。此外，EPS 对 iPSCs 衍生的分化细胞没有遗传毒性。在注射前进行 EPS 处理，可有效防止 p53 野生型（WT）iPSCs 的胚胎畸胎瘤形成，但对 p53KO iPSCs 无效。总之，这些结果表明 EPS 具有强大的抗畸胎瘤活性，对分化细胞没有遗传毒性。因此，它可以用于开发安全有效的基于 iPSC 的细胞疗法。
