Dataset Information

Post-irradiation promotes susceptibility to reprogramming to pluripotent state in human fibroblasts.

ABSTRACT: Ionizing radiation causes not only targeted effects in cells that have been directly irradiated but also non-targeted effects in several cell generations after initial exposure. Recent studies suggest that radiation can enrich for a population of stem cells, derived from differentiated cells, through cellular reprogramming. Here, we elucidate the effect of irradiation on reprogramming, subjected to two different responses, using an induced pluripotent stem cell (iPSC) model. iPSCs were generated from non-irradiated cells, directly-irradiated cells, or cells subsequently generated after initial radiation exposure. We found that direct irradiation negatively affected iPSC induction in a dose-dependent manner. However, in the post-irradiated group, after five subsequent generations, cells became increasingly sensitive to the induction of reprogramming compared to that in non-irradiated cells as observed by an increased number of Tra1-81-stained colonies as well as enhanced alkaline phosphatase and Oct4 promoter activity. Comparative analysis, based on reducing the number of defined factors utilized for reprogramming, also revealed enhanced efficiency of iPSC generation in post-irradiated cells. Furthermore, the phenotypic acquisition of characteristics of pluripotent stem cells was observed in all resulting iPSC lines, as shown by morphology, the expression of pluripotent markers, DNA methylation patterns of pluripotency genes, a normal diploid karyotype, and teratoma formation. Overall, these results suggested that reprogramming capability might be differentially modulated by altered radiation-induced responses. Our findings provide that susceptibility to reprogramming in somatic cells might be improved by the delayed effects of non-targeted response, and contribute to a better understanding of the biological effects of radiation exposure.

SUBMITTER: Lee SB

PROVIDER: S-EPMC5731415 | biostudies-literature | 2017

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Post-irradiation promotes susceptibility to reprogramming to pluripotent state in human fibroblasts.

Lee Seung Bum SB Han Sung-Hoon SH Kim Min-Jung MJ Shim Sehwan S Shin Hye-Yun HY Lee Sun-Joo SJ Kim Hye Won HW Jang Won-Suk WS Seo Songwon S Jang Seongjae S Lee Yanghee Y Park Sunhoo S

Cell cycle (Georgetown, Tex.) 20170914 21

Ionizing radiation causes not only targeted effects in cells that have been directly irradiated but also non-targeted effects in several cell generations after initial exposure. Recent studies suggest that radiation can enrich for a population of stem cells, derived from differentiated cells, through cellular reprogramming. Here, we elucidate the effect of irradiation on reprogramming, subjected to two different responses, using an induced pluripotent stem cell (iPSC) model. iPSCs were generated ...[more]

PMID: 28902577

Similar Datasets

Project description:Reprogramming of somatic cells to the phenotypic state termed "induced pluripotency" is thought to occur through three consecutive stages: initiation, maturation, and stabilisation. The initiation phase is stochastic but nevertheless very important as it sets the gene expression pattern that permits completion of reprogramming; hence a better understanding of this phase and how this is regulated may provide the molecular cues for improving the reprogramming process. c-Jun N-terminal kinase (JNK)/stress-activated protein kinase (SAPKs) are stress activated MAPK kinases that play an essential role in several processes known to be important for successful completion of the initiation phase such as cellular proliferation, mesenchymal to epithelial transition (MET) and cell cycle regulation. In view of this, we postulated that manipulation of this pathway would have significant impacts on reprogramming of human fibroblasts to induced pluripotent stem cells. Accordingly, we found that key components of the JNK/SAPK signaling pathway increase expression as early as day 3 of the reprogramming process and continue to rise in reprogrammed cells throughout the initiation and maturation stages. Using both chemical inhibitors and RNA interference of MKK4, MKK7 and JNK1, we tested the role of JNK/SAPK signaling during the initiation stage of neonatal and adult fibroblast reprogramming. These resulted in complete abrogation of fully reprogrammed colonies and the emergence of partially reprogrammed colonies which disaggregated and were lost from culture during the maturation stage. Inhibition of JNK/SAPK signaling resulted in reduced cell proliferation, disruption of MET and loss of the pluripotent phenotype, which either singly or in combination prevented establishment of pluripotent colonies. Together these data provide new evidence for an indispensable role for JNK/SAPK signaling to overcome the well-established molecular barriers in human somatic cell induced reprogramming. Stem Cells 2016;34:1198-1212.

Project description:Reprogramming somatic cells to induced pluripotent stem cells (iPSCs) eliminates many epigenetic modifications that characterize differentiated cells. In this study, we tested whether functional differences between chronic obstructive pulmonary disease (COPD) and non-COPD fibroblasts could be reduced utilizing this approach. Primary fibroblasts from non-COPD and COPD patients were reprogrammed to iPSCs. Reprogrammed iPSCs were positive for oct3/4, nanog, and sox2, formed embryoid bodies in vitro, and induced teratomas in nonobese diabetic/severe combined immunodeficient mice. Reprogrammed iPSCs were then differentiated into fibroblasts (non-COPD-i and COPD-i) and were assessed either functionally by chemotaxis and gel contraction or for gene expression by microarrays and compared with their corresponding primary fibroblasts. Primary COPD fibroblasts contracted three-dimensional collagen gels and migrated toward fibronectin less robustly than non-COPD fibroblasts. In contrast, redifferentiated fibroblasts from iPSCs derived from the non-COPD and COPD fibroblasts were similar in response in both functional assays. Microarray analysis identified 1,881 genes that were differentially expressed between primary COPD and non-COPD fibroblasts, with 605 genes differing by more than twofold. After redifferentiation, 112 genes were differentially expressed between COPD-i and non-COPD-i with only three genes by more than twofold. Similar findings were observed with microRNA (miRNA) expression: 56 miRNAs were differentially expressed between non-COPD and COPD primary cells; after redifferentiation, only 3 miRNAs were differentially expressed between non-COPD-i and COPD-i fibroblasts. Interestingly, of the 605 genes that were differentially expressed between COPD and non-COPD fibroblasts, 293 genes were changed toward control after redifferentiation. In conclusion, functional and epigenetic alterations of COPD fibroblasts can be reprogrammed through formation of iPSCs.

Dataset Information

Post-irradiation promotes susceptibility to reprogramming to pluripotent state in human fibroblasts.

Publications

Post-irradiation promotes susceptibility to reprogramming to pluripotent state in human fibroblasts.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure