The Experts below are selected from a list of 5991 Experts worldwide ranked by ideXlab platform
Eisuke Nishida - One of the best experts on this subject based on the ideXlab platform.
-
Identification and characterization of secreted factors that are upregulated during somatic cell Reprogramming.
FEBS letters, 2017Co-Authors: Yoshimi Bansho, Eisuke Nishida, Joonseong Lee, May Nakajima-koyamaAbstract:The process of cell Reprogramming has been characterized considerably since the successful generation of induced pluripotent stem cells. However, the importance of cell-cell communications for cellular Reprogramming remains largely unknown. Secreted factors, which are expressed and secreted during Reprogramming, may influence the Reprogramming Efficiency. Here, we have identified Sostdc1, Glb1l2, Fetub, Dpp4, Gdf3, Trh, and Tdgf1 as prominently upregulated secreted factors during Reprogramming. Our detailed analysis reveals that these seven factors may be categorized into four groups based on their expression patterns in relation to the Reprogramming stages. Remarkably, knockdown of Sostdc1, which is the most prominently upregulated factor and which is expressed earlier than the other six factors, results in reduced Reprogramming Efficiency, suggesting its involvement in the Reprogramming process. This article is protected by copyright. All rights reserved.
-
transient expression of wnt2 promotes somatic cell Reprogramming by inducing β catenin nuclear accumulation
Stem cell reports, 2016Co-Authors: Mizuki Kimura, May Nakajimakoyama, Eisuke NishidaAbstract:Treatment with several Wnt/β-catenin signaling pathway regulators can change the cellular Reprogramming Efficiency; however, the dynamics and role of endogenous Wnt/β-catenin signaling in Reprogramming remain largely unanswered. Here we identify the upregulation of WNT2 and subsequent β-catenin nuclear accumulation as key events in Reprogramming. Transient nuclear accumulation of β-catenin occurs early in MEF Reprogramming. Wnt2 is strongly expressed in the early stage of Reprogramming. Wnt2 knockdown suppresses the nuclear accumulation of β-catenin and reduces the Reprogramming Efficiency. WNT2 overexpression promotes β-catenin nuclear accumulation and enhances the Reprogramming Efficiency. WNT2 contributes to the promotion of cell proliferation. Experiments with several drugs that control the Wnt pathway also indicate the importance of β-catenin nuclear accumulation in Reprogramming. Our findings reveal the role of WNT2/β-catenin signaling in Reprogramming.
-
Secreted Ephrin Receptor A7 Promotes Somatic Cell Reprogramming by Inducing ERK Activity Reduction
Stem cell reports, 2015Co-Authors: Joonseong Lee, May Nakajima-koyama, Masamitsu Sone, Makito Koga, Miki Ebisuya, Takuya Yamamoto, Eisuke NishidaAbstract:The role of secreted molecules in cellular Reprogramming has been poorly understood. Here we identify a truncated form of ephrin receptor A7 (EPHA7) as a key regulator of Reprogramming. Truncated EPHA7 is prominently upregulated and secreted during Reprogramming. EPHA7 expression is directly regulated by OCT3/4. EphA7 knockdown results in marked reduction of Reprogramming Efficiency, and the addition of truncated EPHA7 is able to restore it. ERK activity is markedly reduced during Reprogramming, and the secreted, truncated EPHA7 is responsible for ERK activity reduction. Remarkably, treatment of EphA7-knockdown MEFs with the ERK pathway inhibitor restores Reprogramming Efficiency. Analyses show that truncated EPHA7-induced ERK activity reduction plays an important role in the middle phase of Reprogramming. Thus, our findings uncover the importance of secreted EPHA7-induced ERK activity reduction in Reprogramming.
Alexander Kleger - One of the best experts on this subject based on the ideXlab platform.
-
TBX3 Knockdown Decreases Reprogramming Efficiency of Human Cells
Stem cells international, 2015Co-Authors: Moritz Klingenstein, Alexander Kleger, Stefan Liebau, Stefanie Raab, Kevin Achberger, Leonhard LintaAbstract:TBX3 is a member of the T-box transcription factor family and is involved in the core pluripotency network. Despite this role in the pluripotency network, its contribution to the Reprogramming process during the generation of human induced pluripotent stem cells remains elusive. In this respect, we performed Reprogramming experiments applying TBX3 knockdown in human fibroblasts and keratinocytes. Knockdown of TBX3 in both somatic cell types decreased the Reprogramming efficiencies in comparison to control cells but with unchanged Reprogramming kinetics. The resulting iPSCs were indistinguishable from control cells and displayed a normal in vitro differentiation capacity by generating cells of all three germ layers comparable to the controls.
-
A hierarchy in Reprogramming capacity in different tissue microenvironments: what we know and what we need to know
Stem cells and development, 2013Co-Authors: Stefan Liebau, Pallavi U. Mahaddalkar, Hans A. Kestler, Anett Illing, Thomas Seufferlein, Alexander KlegerAbstract:Ectopic expression of certain transcription factors induces Reprogramming of somatic cells to a pluripotent state. A number of studies have shed light on the Reprogramming capacity of various cell populations. As a result, it has been shown that stem/progenitor cells derived from organs of all germ layers exhibit a superior Reprogramming Efficiency compared to their differentiated progeny. Although proliferative capacity and endogenous expression levels of pluripotency factors are likely to be involved in this superiority, the detailed molecular understanding remains elusive so far. Recently, we have shown that the BAF-complex (BAF155 and Brg1), mediating epigenetic changes during Reprogramming, is critical for the increased Reprogramming Efficiency of liver progenitor cells. In this review, we summarize recently acquired findings of the increased Reprogramming capacity of adult stem/progenitor cell populations compared to their differentiated counterparts and discuss the potential mechanisms involved.
-
Increased Reprogramming Capacity of Mouse Liver Progenitor Cells, Compared With Differentiated Liver Cells, Requires the BAF Complex
Gastroenterology, 2012Co-Authors: Alexander Kleger, Pallavi U. Mahaddalkar, Sarah–fee Katz, André Lechel, Jin Young Joo, Komal Loya, Qiong Lin, Daniel Hartmann, Stefan Liebau, Johann M. KrausAbstract:BACKGROUND & AIMS: Ectopic expression of certain transcription factors can reprogram somatic cells to a pluripotent state. Hematopoietic and muscle stem cells can be more efficiently reprogrammed than differentiated blood or muscle cells, yet similar findings have not been shown in other primary organ systems. Moreover, molecular characteristics of the cellular hierarchy of tissues that influence Reprogramming capacities need to be delineated. We analyzed the effect of differentiation stage of freshly isolated, mouse liver cells on the Reprogramming Efficiency. METHODS: Liver progenitor cell (LPC)-enriched cell fractions were isolated from adult (6‐8 wk) and fetal (embryonic day 14.5) livers of mice and reprogrammed to become induced pluripotent stem (iPS) cells. Different transcription factors were expressed in liver cells, and markers of pluripotency were examined, along with the ability of iPS cells to differentiate, in vitro and in vivo, into different germ layers. RESULTS: Fetal and adult LPCs had significantly greater Reprogramming Efficiency after transduction with 3 or 4 Reprogramming factors. Transduction Efficiency-corrected Reprogramming rates of fetal LPCs were 275-fold higher, compared with unsorted fetal liver cells, when 3 Reprogramming factors were transduced. The increased Reprogramming Efficiency of LPCs, compared with differentiated liver cells, occurred independently of proliferation rates, but was associated with endogenous expression of Reprogramming factors (Klf4 and c-Myc) and BAF (Brg1/Brm associated factor)-complex members Baf155 and Brg1, which mediate epigenetic changes during Reprogramming. Knockdown of BAF complex members negated the increased Reprogramming Efficiency of LPCs, compared with non-LPCs. CONCLUSIONS: LPCs have intrinsic, cell proliferation– independent characteristics resulting in an increased Reprogramming capacity compared to differentiated liver cells.
Hal E. Broxmeyer - One of the best experts on this subject based on the ideXlab platform.
-
mir 31 sdha axis regulates Reprogramming Efficiency through mitochondrial metabolism
Stem cell reports, 2016Co-Authors: Man Ryul Lee, Charlie Mantel, Sang A. Lee, Sung-hwan Moon, Hal E. BroxmeyerAbstract:Metabolism is remodeled when somatic cells are reprogrammed into induced pluripotent stem cells (iPSCs), but the majority of iPSCs are not fully reprogrammed. In a shift essential for Reprogramming, iPSCs use less mitochondrial respiration but increased anaerobic glycolysis for bioenergetics. We found that microRNA 31 (miR-31) suppressed succinate dehydrogenase complex subunit A (SDHA) expression, vital for mitochondrial electron transport chain (ETC) complex II. MiR-31 overexpression in partially reprogrammed iPSCs lowered SDHA expression levels and oxygen consumption rates to that of fully reprogrammed iPSCs, but did not increase the proportion of fully reprogrammed TRA1-60(+) cells in colonies unless miR-31 was co-transduced with Yamanaka factors, which resulted in a 2.7-fold increase in full Reprogramming. Thus switching from mitochondrial respiration to glycolytic metabolism through regulation of the miR-31/SDHA axis is critical for lowering the Reprogramming threshold. This is supportive of multi-stage Reprogramming whereby metabolic remodeling is fundamental.
-
MiR-31/SDHA Axis Regulates Reprogramming Efficiency through Mitochondrial Metabolism.
Stem cell reports, 2016Co-Authors: Man Ryul Lee, Charlie Mantel, Sang A. Lee, Sung-hwan Moon, Hal E. BroxmeyerAbstract:Metabolism is remodeled when somatic cells are reprogrammed into induced pluripotent stem cells (iPSCs), but the majority of iPSCs are not fully reprogrammed. In a shift essential for Reprogramming, iPSCs use less mitochondrial respiration but increased anaerobic glycolysis for bioenergetics. We found that microRNA 31 (miR-31) suppressed succinate dehydrogenase complex subunit A (SDHA) expression, vital for mitochondrial electron transport chain (ETC) complex II. MiR-31 overexpression in partially reprogrammed iPSCs lowered SDHA expression levels and oxygen consumption rates to that of fully reprogrammed iPSCs, but did not increase the proportion of fully reprogrammed TRA1-60(+) cells in colonies unless miR-31 was co-transduced with Yamanaka factors, which resulted in a 2.7-fold increase in full Reprogramming. Thus switching from mitochondrial respiration to glycolytic metabolism through regulation of the miR-31/SDHA axis is critical for lowering the Reprogramming threshold. This is supportive of multi-stage Reprogramming whereby metabolic remodeling is fundamental.
Man Ryul Lee - One of the best experts on this subject based on the ideXlab platform.
-
mir 31 sdha axis regulates Reprogramming Efficiency through mitochondrial metabolism
Stem cell reports, 2016Co-Authors: Man Ryul Lee, Charlie Mantel, Sang A. Lee, Sung-hwan Moon, Hal E. BroxmeyerAbstract:Metabolism is remodeled when somatic cells are reprogrammed into induced pluripotent stem cells (iPSCs), but the majority of iPSCs are not fully reprogrammed. In a shift essential for Reprogramming, iPSCs use less mitochondrial respiration but increased anaerobic glycolysis for bioenergetics. We found that microRNA 31 (miR-31) suppressed succinate dehydrogenase complex subunit A (SDHA) expression, vital for mitochondrial electron transport chain (ETC) complex II. MiR-31 overexpression in partially reprogrammed iPSCs lowered SDHA expression levels and oxygen consumption rates to that of fully reprogrammed iPSCs, but did not increase the proportion of fully reprogrammed TRA1-60(+) cells in colonies unless miR-31 was co-transduced with Yamanaka factors, which resulted in a 2.7-fold increase in full Reprogramming. Thus switching from mitochondrial respiration to glycolytic metabolism through regulation of the miR-31/SDHA axis is critical for lowering the Reprogramming threshold. This is supportive of multi-stage Reprogramming whereby metabolic remodeling is fundamental.
-
MiR-31/SDHA Axis Regulates Reprogramming Efficiency through Mitochondrial Metabolism.
Stem cell reports, 2016Co-Authors: Man Ryul Lee, Charlie Mantel, Sang A. Lee, Sung-hwan Moon, Hal E. BroxmeyerAbstract:Metabolism is remodeled when somatic cells are reprogrammed into induced pluripotent stem cells (iPSCs), but the majority of iPSCs are not fully reprogrammed. In a shift essential for Reprogramming, iPSCs use less mitochondrial respiration but increased anaerobic glycolysis for bioenergetics. We found that microRNA 31 (miR-31) suppressed succinate dehydrogenase complex subunit A (SDHA) expression, vital for mitochondrial electron transport chain (ETC) complex II. MiR-31 overexpression in partially reprogrammed iPSCs lowered SDHA expression levels and oxygen consumption rates to that of fully reprogrammed iPSCs, but did not increase the proportion of fully reprogrammed TRA1-60(+) cells in colonies unless miR-31 was co-transduced with Yamanaka factors, which resulted in a 2.7-fold increase in full Reprogramming. Thus switching from mitochondrial respiration to glycolytic metabolism through regulation of the miR-31/SDHA axis is critical for lowering the Reprogramming threshold. This is supportive of multi-stage Reprogramming whereby metabolic remodeling is fundamental.
Yigang Wang - One of the best experts on this subject based on the ideXlab platform.
-
Blockade of senescence‐associated microRNA‐195 in aged skeletal muscle cells facilitates Reprogramming to produce induced pluripotent stem cells.
Aging cell, 2015Co-Authors: Hideyuki Kondo, Lei Wang, Ha Won Kim, Motoi Okada, Christian Paul, Ronald W. Millard, Yigang WangAbstract:The low Reprogramming Efficiency in cells from elderly patients is a challenge that must be overcome. Recently, it has been reported that senescence-associated microRNA (miR)-195 targets Sirtuin 1 (SIRT1) to advance cellular senescence. Thus, we hypothesized that a blockade of miR-195 expression could improve Reprogramming Efficiency in old skeletal myoblasts (SkMs). We found that miR-195 expression was significantly higher in old SkMs (24 months) isolated from C57BL/6 mice as compared to young SkMs (2 months, 2.3-fold). Expression of SIRT1 and telomerase reverse transcriptase (TERT) was downregulated in old SkMs, and transduction of old SkMs with lentiviral miR-195 inhibitor significantly restored their expression. Furthermore, quantitative in situ hybridization analysis demonstrated significant telomere elongation in old SkMs transduced with anti-miR-195 (1.7-fold increase). It is important to note that blocking miR-195 expression markedly increased the Reprogramming Efficiency of old SkMs as compared to scramble (2.2-fold increase). Transduction of anti-miR-195 did not alter karyotype or pluripotency marker expression. Induced pluripotent stem cells (iPSCs) from old SkMs transduced with anti-miR-195 successfully formed embryoid bodies that spontaneously differentiated into three germ layers, indicating that deletion of miR-195 does not affect pluripotency in transformed SkMs. In conclusion, this study provided novel evidence that the blockade of age-induced miR-195 is a promising approach for efficient iPSC generation from aging donor subjects, which has the potential for autologous transplantation of iPSCs in elderly patients.
-
Abstract 15481: Abrogation of Senescence-associated Microrna-195 in Aged Skeletal Myoblasts Facilitates Reprogramming to Produce Induced Pluripotent Stem Cells
Circulation, 2014Co-Authors: Hideyuki Kondo, Ha Won Kim, Ronald W. Millard, Yigang WangAbstract:Background: Older age is the major risk factors for heart failure, and Reprogramming a patient’s own cells to produce induced pluripotent stem cells (iPSCs) is a promising strategy for autologous cell transplantation therapy. However, low Reprogramming Efficiency of senescent cells remains as a major pitfall. Recently, we have shown that inhibition of senescence-associated miR-195 rejuvenated aged stem cells by reactivating telomerase reverse transcriptase (Tert). This study investigated the effects of abrogation of miR-195 expression on the Reprogramming Efficiency of old skeletal myoblasts (OSkMs). Methods and Results: MiR-195 expression was significantly higher in OSkMs isolated from aged mice (24 months) as compared to SkMs from young mice (2 months), as examined by RT-PCR. In addition, OSkMs showed impaired expression of anti-aging factors (Tert and Sirt1) and higher expression of pro-aging markers (p53, p21, p16). Intriguingly, blockage of miR-195 expression in OSkMs by transfection with anti-miR-195 significantly induced expression of Tert and Sirt1 as well as telomere re-lengthening as examined by RT-PCR and quantitative fluorescent in situ hybridization (Q-FISH). It is important to note that lower Reprogramming Efficiency of OSkMs was improved by miR-195 abrogation. Notably, inhibition of miR-195 did not alter karyotype or expression of pluripotency markers, and iPSCs lacking miR-195 successfully differentiated into all three germ layers, indicating that deletion of miR-195 does not affect pluripotency. Furthermore, contraction rates were markedly higher in beating cells transfected with anti-miR-195 as compared to that with scramble (68.5±5.6 vs 47.3±2.8/min). Conclusions: Abrogation of age-induced miR-195 is a novel promising approach for efficient iPSCs generation from senescent cells, which will contribute to successful autologous transplantation therapy in elderly patients.