Cytoplasmic dsRNA induces the expression of OCT3/4 and NANOG mRNAs in differentiated human cells
Cytoplasmic dsRNA induces the expression of OCT3/4 and NANOG mRNAs in differentiated human cells
复制标题
DOI：
10.1074/jbc.ra119.009783
复制
发表时间：
2019-12-13
影响因子：
4.8
通讯作者：
Oshiumi, Hiroyuki
中科院分区：
文献类型：
--
作者：
Wang, Guanming;Kouwaki, Takahisa;Oshiumi, Hiroyuki
细胞质dsRNA被RNA解旋酶RIG-I（RIG-I）和黑色素瘤分化相关蛋白5（MDA 5）识别，通过线粒体抗病毒信号蛋白（MAVS）触发先天免疫应答的诱导。相比之下，细胞外dsRNA内化到内体中并被Toll样受体3（TLR 3）识别，其通过Toll样受体衔接分子1（TICAM-1）触发信号传导。Poly I：C是一种合成的dsRNA类似物，在多能性诱导过程中增加八聚体结合蛋白3/4（OCT 3/4）、NANOG和SRY盒（SOX）mRNA的表达。然而，这种增加的机制尚不清楚。在这里，我们集中在多聚I：C诱导的干细胞特异性基因在人体细胞中的表达的机制。在人成纤维细胞培养基中加入poly I：C并不增加OCT 3/4 mRNA的表达，但poly I：C转染显著增加OCT 3/4的表达，并诱导OCT 3/4蛋白的核定位，这意味着OCT 3/4表达所需的不是TLR 3，而是RIG-1和MDA 5。此外，虽然胞质dsRNA增加OCT 3/4 mRNA，胞质dsDNA，如鲑鱼精子DNA和聚dA：dT，没有。有趣的是，NANOG，SOX 2，Kruppel样因子4（KLF 4）和原癌基因c-Myc的表达也被胞质dsRNA增加。值得注意的是，沉默MAVS和干扰素调节因子1（IRF 1）表达的siRNA在用聚I：C刺激后降低了OCT 3/4水平;然而，NF-B抑制剂和siRNA介导的原癌基因c-Jun敲低并未显著降低mRNA水平。我们的结论是，细胞质dsRNA增加干细胞特异性基因在人体细胞中的表达，在MAVS和IRF 1依赖的方式。
Cytoplasmic dsRNA is recognized by RNA helicase RIG-I (RIG-I) and melanoma differentiation-associated protein 5 (MDA5), triggering induction of the innate immune response via the mitochondrial antiviral signaling protein (MAVS). In contrast, extracellular dsRNA is internalized into endosomes and recognized by Toll-like receptor 3 (TLR3), which triggers signaling via the Toll-like receptor adaptor molecule 1 (TICAM-1). Poly I:C is a synthetic dsRNA analog and increases the expression of octamer-binding protein 3/4 (OCT3/4), NANOG, and SRY-box (SOX) mRNAs during pluripotency induction. However, the mechanism underlying this increase is unclear. Here, we focused on the mechanism of poly I:C-induced expression of stem cell-specific genes in human somatic cells. Addition of poly I:C to human fibroblast culture medium did not increase OCT3/4 mRNA expression, but poly I:C transfection markedly increased OCT3/4 expression and induced nuclear localization of the OCT3/4 protein, implying that not TLR3, but RIG-I and MDA5 are required for OCT3/4 expression. Moreover, although cytoplasmic dsRNA increased OCT3/4 mRNA, cytoplasmic dsDNAs, such as salmon-sperm DNA and poly dA:dT, did not. Interestingly, the expression of NANOG, SOX2, Kruppel-like factor 4 (KLF4), and proto-oncogene c-Myc was also increased by cytoplasmic dsRNA. Of note, siRNAs that silenced MAVS and interferon regulatory factor 1 (IRF1) expression reduced OCT3/4 levels after stimulation with poly I:C; however, an NF-.B inhibitor and siRNA-mediated knockdown of proto-oncogene c-Jun did not significantly reduce the mRNA levels. We conclude that cytoplasmic dsRNA increases the expression of stem cell-specific genes in human somatic cells in a MAVS- and IRF1-dependent manner.