iPSCs are transcriptionally and post-transcriptionally indistinguishable from fESCs

ArticleinFrontiers in Bioscience 17:1659-68 · January 2012with2 Reads
Source: PubMed
Induced pluripotent stem cells (iPSCs) are generated by reprogramming mouse or human somatic cells to a pluripotent state by introducing key transcription factors and have great therapeutic potential. It has been illustrated that the transcriptional and post-transcriptional profiles of nuclear-transferred embryonic stem cells (ntESCs) is identical to those of embryonic stem cells derived from fertilized blastocysts (fESCs). Although iPSCs seem to be indistinguishable from fESCs, the degree of transcriptomic and proteomic similarity among iPSCs, ntESCs, and fESCs has not yet been elucidated completely. To investigate whether iPSCs and fESCs have similar therapeutic potential, we compared mRNA and protein pro?les of mouse iPSC, ntESCs, and matching fESCs lines using microarray technology, iTRAQ method, and bioinformatic analyses. Real-time PCR, two-dimensional LC, and MS/MS analyses were further conducted to study the expression of speci?c transcripts and identify and quantitate 929 proteins. Our results demonstrate that, like ntESCs, the iPSC and matching fESCs lines have very similar transcriptional and protein expression profiles. This is consistent with their similar developmental potential.
    • "In agreement with the aforementioned studies, the significant reduction in global DNA methylation and H3K9me3 observed in the murine somatic cells in this study indicates that reprogramming has been initiated. Other proteomic studies have compared proteomic profiles of iPSCs with ESCs ( Jin et al., 2011; Kim et al., 2012; Munoz et al., 2011; Wang et al., 2012), or protein expression changes of iPSCs that have been cultured for days or weeks post-reprogramming compared to the somatic cells from which they were derived (Huang et al., 2012; Kim et al., 2012; Munoz et al., 2011; Pewsey et al., 2009). In the current study, we chose to concentrate on global nuclear protein expression changes during the early stages of reprogramming, before the cells express pluripotency markers. "
    [Show abstract] [Hide abstract] ABSTRACT: Abstract The reprogramming of somatic cells into a pluripotent/embryonic-like state holds great potential for regenerative medicine, bypassing ethical issues associated with embryonic stem cells (ESCs). Numerous methods, including somatic cell nuclear transfer (SCNT), fusion to pluripotent cells, the use of cell extracts, and expression of transcription factors, have been used to reprogram cells into ES-like cells [termed induced pluripotent stem cells (iPSCs)]. This study investigated early events in the nuclei of permeabilized murine somatic cells incubated in cytoplasmic extract prepared from Xenopus laevis germinal vesicle-stage oocytes by identifying proteins that showed significant quantitative changes using proteomic techniques. A total of 69 protein spots from two-dimensional electrophoresis were identified as being significantly altered in expression after treatment, and 38 proteins were identified by tandem mass spectrometry. Network analysis was used to highlight pathway connections and interactions between these identified proteins, which were found to be involved in many functions-primarily nuclear structure and dynamics, transcription, and translation. The pluripotency markers Klf4, c-Myc, Nanog, and POU5F1 were highlighted by the interaction network analysis, as well as other compounds/proteins known to be repressed in pluripotent cells [e.g., protein kinase C (PRKC)] or enhanced during differentiation of ESCs (e.g., retinoic acid). The network analysis also indicated additional proteins and pathways potentially involved in early reprogramming events.
    Full-text · Article · Jun 2013