Induction of reprogramming of human amniotic epithelial cells into iPS cells by overexpression of Yap, Oct4, and Sox2 through the activation of the Hippo-Yap pathway

Abstract

The present study has reported a novel method for producing induced pluripotent stem (iPS) cells. Primary human amniotic epithelial cells (HuAECs) were isolated from the amniotic membranes of pregnant women who received Cesarean sections. These cells were infected with retroviruses carrying octamer-binding transcription factor 4 (Oct4), (sex determining region Y)-box 2 (Sox2) and Yes-associated protein (Yap) (OSY). Following in vitro culture for ~14 days, epithelial-like HuAECs exhibited several iPS clone-like cell colonies (OSY-iPS). These cell clones presented positive alkaline phosphatase features and expressed high levels of embryonic stem cell-like markers (Nanog homeobox, Sox2, Oct4, reduced expression protein 1, and SSES3/4). Additionally, epigenetic analysis results indicated that the methylation of CpG islands on endogenous Oct4 and Sox2 promoters was reduced in OSY-iPS cells. Furthermore, the majority of the histone H3 at lysine 9 sites that interacted with the Oct4 and Sox2 promoters were acetylated, suggesting that the transcription activities of the above two transcription factors significantly increased. In vivo and in vitro induced differentiation experiments demonstrated that OSY-iPS could develop into embryoid bodies in vitro, and express numerous cellular markers in the three germ layers. Furthermore, OSY-iPS could form teratomas in immunodeficient mice. The pathological detection results suggest that these teratomas contain numerous types of cells from the three germ layers. However, the results from the quantitative polymerase chain reaction and western blot analyses suggest that the Hippo-Yap signaling pathway was significantly activated in OSY-iPS cells. In conclusion, a novel method for iPS induction was established in the present study. HuAECs were successfully induced to reprogram iPS cells through the introduction of OSY to activate the Hippo-Yap signaling pathway.

WW Domain-Containing Proteins YAP and TAZ in the Hippo Pathway as Key Regulators in Stemness Maintenance, Tissue Homeostasis, and Tumorigenesis

“…The role of YAP in controlling pluripotency is seen in induced pluripotent stem cells (iPSCs), which was established by using the ectopic expression of Oct3/4, Sox2, Klf4 , and c-Myc genes closely resemble that of ESCs in phenotype and differentiation potential (124, 134). YAP is activated during the reprogramming process of human embryonic fibroblasts into iPSCs, and the addition of YAP to original four factors increases the reprogramming efficiency in mouse embryonic fibroblasts, further confirming a positive role of YAP in stemness (135). As in human ESCs, the interaction between YAP and TEADs directs transcriptional circumstances important for maintaining pluripotency.…”

“…In human iPSC, knockdown of LATS2 increases the reprogramming efficiency of iPSCs (136). Moreover, a recent study reported the success in reprograming of iPSCs derived from primary human amniotic epithelial cells (HuAECs) through the introduction of OSY ( OCT3/4, SOX2 , and YAP ) to activate the Hippo-Yap signaling pathway (135).…”

Role of YAP/TAZ in Cell Lineage Fate Determination and Related Signaling Pathways

“…Perhaps the most compelling evidence of the role of YAP/TAZ in the self-renewal and pluripotency of human pluripotent stem cells comes from studies on reprogramming adult somatic cells into iPSCs. Zhao et al (2017) reported that when YAP is ectopically expressed, only two reprogramming factors -Oct4 and Sox2 -instead of the usual four reprogramming factors (Oct4, Sox2, c-Myc and Klf4) are required to reprogram human amniotic epithelial cells into iPSCs. Qin et al (2012) showed that knockdown of LATS2, a key component of the Hippo pathway involved in the phosphorylation of YAP, which facilitates its retention within the cytosol, could increase the efficiency of reprogramming of human somatic cells into iPSCs.…”

Oxidized low‐density lipoprotein promotes vascular endothelial cell dysfunction by stimulating miR‐496 expression and inhibiting the Hippo pathway effector YAP

“…miRNAs have no open reading frame and do not encode a protein product with a specific function, but as single-stranded ncRNAs, they can reverse-complement with the mRNA transcripts of other genes to silence the target genes after transcription. In addition, YAP plays an important role in cell division and differentiation, stem cell fate decisions, and tumorigenesis and progression (Zhao et al, 2011;Xie et al, 2012;He et al, 2017;Li et al, 2017;Xiao et al, 2017;Zhang et al, 2017;Zhao et al, 2017;Zhuo and Kang, 2017). The Hippo-YAP/TAZ (Yesassociated protein/YLP motif-containing 1) pathway is a kinase cascade consisting of a series of protein kinases and transcription factors.…”

“…The loss of nuclear YAP blocks Hippo-YAP/TAZ pathway activity and inhibits further cell and tissue growth (Xie et al, 2012;Cabochette et al, 2015). In addition, YAP plays an important role in cell division and differentiation, stem cell fate decisions, and tumorigenesis and progression (Zhao et al, 2011;Xie et al, 2012;He et al, 2017;Li et al, 2017;Xiao et al, 2017;Zhang et al, 2017;Zhao et al, 2017;Zhuo and Kang, 2017). Recently, an increasing number of studies have shown that Hippo-YAP/TAZ signaling has emerged as a new pathway for blood vessel development (Park and Kwon, 2018).…”