المؤلفون: Hiroyuki Imai, Kiyoshi Kano, Wataru Fujii, Ken Takasawa, Shoichi Wakitani, Masato Hiyama, Koichiro Nishino, Ken Takeshi Kusakabe, Yasuo Kiso

المصدر: PLoS ONE, Vol 10, Iss 6, p e0130585 (2015)

مصطلحات موضوعية: Medicine, Science

الوصف: Polyploid amphibians and fishes occur naturally in nature, while polyploid mammals do not. For example, tetraploid mouse embryos normally develop into blastocysts, but exhibit abnormalities and die soon after implantation. Thus, polyploidization is thought to be harmful during early mammalian development. However, the mechanisms through which polyploidization disrupts development are still poorly understood. In this study, we aimed to elucidate how genome duplication affects early mammalian development. To this end, we established tetraploid embryonic stem cells (TESCs) produced from the inner cell masses of tetraploid blastocysts using electrofusion of two-cell embryos in mice and studied the developmental potential of TESCs. We demonstrated that TESCs possessed essential pluripotency and differentiation potency to form teratomas, which differentiated into the three germ layers, including diploid embryonic stem cells. TESCs also contributed to the inner cell masses in aggregated chimeric blastocysts, despite the observation that tetraploid embryos fail in normal development soon after implantation in mice. In TESCs, stability after several passages, colony morphology, and alkaline phosphatase activity were similar to those of diploid ESCs. TESCs also exhibited sufficient expression and localization of pluripotent markers and retained the normal epigenetic status of relevant reprogramming factors. TESCs proliferated at a slower rate than ESCs, indicating that the difference in genomic dosage was responsible for the different growth rates. Thus, our findings suggested that mouse ESCs maintained intrinsic pluripotency and differentiation potential despite tetraploidization, providing insights into our understanding of developmental elimination in polyploid mammals.

وصف الملف: electronic resource

العلاقة: http://europepmc.org/articles/PMC4474668?pdf=renderTest; https://doaj.org/toc/1932-6203Test

الوصول الحر: https://doaj.org/article/60cd8c08f91341058cb98998a16cbf12Test

المؤلفون: Yoshiaki Yamagata, Koichiro Nishino, Eiichi Takaki, Shun Sato, Ryo Maekawa, Akira Nakai, Norihiro Sugino

المصدر: PLoS ONE, Vol 9, Iss 1, p e83612 (2014)

مصطلحات موضوعية: Medicine, Science

الوصف: The objective of this study was to characterize the genome-wide DNA methylation profiles of isolated endometrial stromal cells obtained from eutopic endometria with (euESCa) and without endometriosis (euESCb) and ovarian endometrial cysts (choESC). Three samples were analyzed in each group. The infinium methylation array identified more hypermethylated and hypomethylated CpGs in choESC than in euESCa, and only a few genes were methylated differently in euESCa and euESCb. A functional analysis revealed that signal transduction, developmental processes, immunity, etc. were different in choESC and euESCa. A clustering analysis and a principal component analysis performed based on the methylation levels segregated choESC from euESC, while euESCa and euESCb were identical. A transcriptome analysis was then conducted and the results were compared with those of the DNA methylation analysis. Interestingly, the hierarchical clustering and principal component analyses showed that choESC were segregated from euESCa and euESCb in the DNA methylation analysis, while no segregation was recognized in the transcriptome analysis. The mRNA expression levels of the epigenetic modification enzymes, including DNA methyltransferases, obtained from the specimens were not significantly different between the groups. Some of the differentially methylated and/or expressed genes (NR5A1, STAR, STRA6 and HSD17B2), which are related with steroidogenesis, were validated by independent methods in a larger number of samples. Our findings indicate that different DNA methylation profiles exist in ectopic ESC, highlighting the benefits of genome wide DNA methylation analyses over transcriptome analyses in clarifying the development and characterization of endometriosis.

وصف الملف: electronic resource

العلاقة: http://europepmc.org/articles/PMC3900404?pdf=renderTest; https://doaj.org/toc/1932-6203Test

الوصول الحر: https://doaj.org/article/06eeb3ab3d1b4713b30cfdc946034701Test

المؤلفون: Koichiro Nishino, Masashi Toyoda, Mayu Yamazaki-Inoue, Yoshihiro Fukawatase, Emi Chikazawa, Hironari Sakaguchi, Hidenori Akutsu, Akihiro Umezawa

المصدر: PLoS Genetics, Vol 7, Iss 5, p e1002085 (2011)

مصطلحات موضوعية: Genetics, QH426-470

الوصف: Epigenetic reprogramming is a critical event in the generation of induced pluripotent stem cells (iPSCs). Here, we determined the DNA methylation profiles of 22 human iPSC lines derived from five different cell types (human endometrium, placental artery endothelium, amnion, fetal lung fibroblast, and menstrual blood cell) and five human embryonic stem cell (ESC) lines, and we followed the aberrant methylation sites in iPSCs for up to 42 weeks. The iPSCs exhibited distinct epigenetic differences from ESCs, which were caused by aberrant methylation at early passages. Multiple appearances and then disappearances of random aberrant methylation were detected throughout iPSC reprogramming. Continuous passaging of the iPSCs diminished the differences between iPSCs and ESCs, implying that iPSCs lose the characteristics inherited from the parent cells and adapt to very closely resemble ESCs over time. Human iPSCs were gradually reprogrammed through the "convergence" of aberrant hyper-methylation events that continuously appeared in a de novo manner. This iPS reprogramming consisted of stochastic de novo methylation and selection/fixation of methylation in an environment suitable for ESCs. Taken together, random methylation and convergence are driving forces for long-term reprogramming of iPSCs to ESCs.

وصف الملف: electronic resource

العلاقة: http://europepmc.org/articles/PMC3102737?pdf=renderTest; https://doaj.org/toc/1553-7390Test; https://doaj.org/toc/1553-7404Test

الوصول الحر: https://doaj.org/article/0a482068ad184801baf1e2363f72a32aTest

المؤلفون: Koichiro Nishino, Masashi Toyoda, Mayu Yamazaki-Inoue, Hatsune Makino, Yoshihiro Fukawatase, Emi Chikazawa, Yoriko Takahashi, Yoshitaka Miyagawa, Hajime Okita, Nobutaka Kiyokawa, Hidenori Akutsu, Akihiro Umezawa

المصدر: PLoS ONE, Vol 5, Iss 9, p e13017 (2010)

مصطلحات موضوعية: Medicine, Science

الوصف: BACKGROUND: Human induced pluripotent stem (iPS) cells are currently used as powerful resources in regenerative medicine. During very early developmental stages, DNA methylation decreases to an overall low level at the blastocyst stage, from which embryonic stem cells are derived. Therefore, pluripotent stem cells, such as ES and iPS cells, are considered to have hypo-methylated status compared to differentiated cells. However, epigenetic mechanisms of "stemness" remain unknown in iPS cells derived from extra-embryonic and embryonic cells. METHODOLOGY/PRINCIPAL FINDINGS: We examined genome-wide DNA methylation (24,949 CpG sites covering 1,3862 genes, mostly selected from promoter regions) with six human iPS cell lines derived from human amniotic cells and fetal lung fibroblasts as well as two human ES cell lines, and eight human differentiated cell lines using Illumina's Infinium HumanMethylation27. A considerable fraction (807 sites) exhibited a distinct difference in the methylation level between the iPS/ES cells and differentiated cells, with 87.6% hyper-methylation seen in iPS/ES cells. However, a limited fraction of CpG sites with hypo-methylation was found in promoters of genes encoding transcription factors. Thus, a group of genes becomes active through a decrease of methylation in their promoters. Twenty-three genes including SOX15, SALL4, TDGF1, PPP1R16B and SOX10 as well as POU5F1 were defined as genes with hypo-methylated SS-DMR (Stem cell-Specific Differentially Methylated Region) and highly expression in iPS/ES cells. CONCLUSIONS/SIGNIFICANCE: We show that DNA methylation profile of human amniotic iPS cells as well as fibroblast iPS cells, and defined the SS-DMRs. Knowledge of epigenetic information across iPS cells derived from different cell types can be used as a signature for "stemness" and may allow us to screen for optimum iPS/ES cells and to validate and monitor iPS/ES cell derivatives for human therapeutic applications.

وصف الملف: electronic resource

العلاقة: http://europepmc.org/articles/PMC2946409?pdf=renderTest; https://doaj.org/toc/1932-6203Test

الوصول الحر: https://doaj.org/article/c8579aa4ed5147ff8222381a9ba652e2Test

المؤلفون: Masato Hiyama, Hiroyuki Imai, Koichiro Nishino, Kiyoshi Kano, Ken Takeshi Kusakabe, Shoichi Wakitani, Ken Takasawa, Wataru Fujii, Yasuo Kiso

المصدر: PLoS ONE
PLoS ONE, Vol 10, Iss 6, p e0130585 (2015)

مصطلحات موضوعية: lcsh:Medicine, Germ layer, Biology, Mice, Polyploid, Genes, Reporter, Animals, Epigenetics, lcsh:Science, Embryonic Stem Cells, Cell Proliferation, Genetics, Multidisciplinary, Tetraploid complementation assay, lcsh:R, fungi, food and beverages, Cell Differentiation, Embryo, DNA Methylation, Embryo, Mammalian, Embryonic stem cell, Cell biology, Tetraploidy, Blastocyst, embryonic structures, lcsh:Q, Female, Ploidy, Reprogramming, Germ Layers, Transcription Factors, Research Article

الوصف: Polyploid amphibians and fishes occur naturally in nature, while polyploid mammals do not. For example, tetraploid mouse embryos normally develop into blastocysts, but exhibit abnormalities and die soon after implantation. Thus, polyploidization is thought to be harmful during early mammalian development. However, the mechanisms through which polyploidization disrupts development are still poorly understood. In this study, we aimed to elucidate how genome duplication affects early mammalian development. To this end, we established tetraploid embryonic stem cells (TESCs) produced from the inner cell masses of tetraploid blastocysts using electrofusion of two-cell embryos in mice and studied the developmental potential of TESCs. We demonstrated that TESCs possessed essential pluripotency and differentiation potency to form teratomas, which differentiated into the three germ layers, including diploid embryonic stem cells. TESCs also contributed to the inner cell masses in aggregated chimeric blastocysts, despite the observation that tetraploid embryos fail in normal development soon after implantation in mice. In TESCs, stability after several passages, colony morphology, and alkaline phosphatase activity were similar to those of diploid ESCs. TESCs also exhibited sufficient expression and localization of pluripotent markers and retained the normal epigenetic status of relevant reprogramming factors. TESCs proliferated at a slower rate than ESCs, indicating that the difference in genomic dosage was responsible for the different growth rates. Thus, our findings suggested that mouse ESCs maintained intrinsic pluripotency and differentiation potential despite tetraploidization, providing insights into our understanding of developmental elimination in polyploid mammals.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::cd0c35ff30da4889285f44be8342be60Test
https://doi.org/10.1371/journal.pone.0130585Test

المؤلفون: Yoshihiro Fukawatase, Akihiro Umezawa, Yoshitaka Miyagawa, Nobutaka Kiyokawa, Emi Chikazawa, Mayu Yamazaki-Inoue, Hatsune Makino, Koichiro Nishino, Masashi Toyoda, Yoriko Takahashi, Hajime Okita, Hidenori Akutsu

المصدر: PLoS ONE
PLoS ONE, Vol 5, Iss 9, p e13017 (2010)

مصطلحات موضوعية: Cell type, Cellular differentiation, Induced Pluripotent Stem Cells, lcsh:Medicine, Biology, Molecular Biology/Bioinformatics, Cell Line, Epigenesis, Genetic, Genetics and Genomics/Epigenetics, Humans, Amnion, Epigenetics, lcsh:Science, Promoter Regions, Genetic, Induced pluripotent stem cell, Lung, Molecular Biology/DNA Methylation, Cells, Cultured, Embryonic Stem Cells, Multidisciplinary, lcsh:R, Cell Differentiation, DNA Methylation, Fibroblasts, Embryonic stem cell, Molecular biology, Developmental Biology/Stem Cells, Cell culture, DNA methylation, lcsh:Q, Stem cell, Research Article, Transcription Factors

الوصف: Background Human induced pluripotent stem (iPS) cells are currently used as powerful resources in regenerative medicine. During very early developmental stages, DNA methylation decreases to an overall low level at the blastocyst stage, from which embryonic stem cells are derived.Therefore, pluripotent stem cells, such as ES and iPS cells, are considered to have hypo-methylated status compared to differentiated cells. However, epigenetic mechanisms of “stemness” remain unknown in iPS cells derived from extra-embryonic and embryonic cells. Methodology/Principal Findings We examined genome-wide DNA methylation (24,949 CpG sites covering 1,3862 genes, mostly selected from promoter regions) with six human iPS cell lines derived from human amniotic cells and fetal lung fibroblasts as well as two human ES cell lines, and eight human differentiated cell lines using Illumina's Infinium HumanMethylation27. A considerable fraction (807 sites) exhibited a distinct difference in the methylation level between the iPS/ES cells and differentiated cells, with 87.6% hyper-methylation seen in iPS/ES cells. However, a limited fraction of CpG sites with hypo-methylation was found in promoters of genes encoding transcription factors. Thus, a group of genes becomes active through a decrease of methylation in their promoters. Twenty-three genes including SOX15, SALL4, TDGF1, PPP1R16B and SOX10 as well as POU5F1 were defined as genes with hypo-methylated SS-DMR (Stem cell-Specific Differentially Methylated Region) and highly expression in iPS/ES cells. Conclusions/Significance We show that DNA methylation profile of human amniotic iPS cells as well as fibroblast iPS cells, and defined the SS-DMRs. Knowledge of epigenetic information across iPS cells derived from different cell types can be used as a signature for “stemness” and may allow us to screen for optimum iPS/ES cells and to validate and monitor iPS/ES cell derivatives for human therapeutic applications.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::d74a348af4f6041f0cf287f8ca3439e7Test
https://doi.org/10.1371/journal.pone.0013017Test