Author
Margaret S. Inokuma
Bio: Margaret S. Inokuma is an academic researcher from Geron Corporation. The author has contributed to research in topics: Stem cell & Embryonic stem cell. The author has an hindex of 14, co-authored 35 publications receiving 5234 citations.
Papers
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TL;DR: A successful feeder-free hES culture system in which undifferentiated cells can be maintained for at least 130 population doublings and are suitable for scaleup production is demonstrated.
Abstract: Previous studies have shown that maintenance of undifferentiated human embryonic stem (hES) cells requires culture on mouse embryonic fibroblast (MEF) feeders. Here we demonstrate a successful feeder-free hES culture system in which undifferentiated cells can be maintained for at least 130 population doublings. In this system, hES cells are cultured on Matrigel or laminin in medium conditioned by MEF. The hES cells maintained on feeders or off feeders express integrin alpha6 and beta1, which may form a laminin-specific receptor. The hES cell populations in feeder-free conditions maintained a normal karyotype, stable proliferation rate, and high telomerase activity. Similar to cells cultured on feeders, hES cells maintained under feeder-free conditions expressed OCT-4, hTERT, alkaline phosphatase, and surface markers including SSEA-4, Tra 1-60, and Tra 1-81. In addition, hES cells maintained without direct feeder contact formed teratomas in SCID/beige mice and differentiated in vitro into cells from all three germ layers. Thus, the cells retain fundamental characteristics of hES cells in this culture system and are suitable for scaleup production.
2,092 citations
TL;DR: The clonal derivation of two human ES cell lines, H9.1 and H.2, demonstrates the pluripotency of single human ES cells, the maintenance of pluripOTency during an extended period of culture, and the long-term self-renewing properties of cultured human ES Cells.
1,680 citations
TL;DR: The properties of the hES-derived progenitors and neurons were found to be similar to those of cells derived from primary tissue and indicate that hES cells could provide a cell source for the neural progenitor cells and mature neurons for therapeutic and toxicological uses.
556 citations
Patent•
10 Jan 2001
TL;DR: In this article, an improved system for culturing human pluripotent stem (pPS) cells in the absence of feeder cells is described, which allows for bulk proliferation of pPS cells for use in studying the biology of PPS cell differentiation.
Abstract: This disclosure provides an improved system for culturing human pluripotent stem (pPS) cells in the absence of feeder cells. The role of the feeder cells can be replaced by supporting the culture on an extracellular matrix, and culturing the cells in a conditioned medium. Permanent cell lines are provided that can produce conditioned medium on a commercial scale. Methods have also been discovered to genetically alter pPS cells by introducing the cells with a viral vector or DNA/lipid complex. The system described in this disclosure allows for bulk proliferation of pPS cells for use in studying the biology of pPS cell differentiation, and the production of important products for use in human therapy.
216 citations
Patent•
06 Dec 2002TL;DR: In this paper, a system for producing pancreatic islet cells from embryonic stem cells was presented, where differentiation was initiated towards endoderm cells, and focused using reagents that promote emergence of islet precursors and mature insulin-secreting cells.
Abstract: This disclosure provides a system for producing pancreatic islet cells from embryonic stem cells. Differentiation is initiated towards endoderm cells, and focused using reagents that promote emergence of islet precursors and mature insulin-secreting cells. High quality populations of islet cells can be produced in commercial quantities for use in research, drug screening, or regenerative medicine.
187 citations
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TL;DR: It is demonstrated that iPS cells can be generated from adult human fibroblasts with the same four factors: Oct3/4, Sox2, Klf4, and c-Myc.
18,175 citations
TL;DR: This work generated induced pluripotent stem cells capable of germline transmission from murine somatic cells by transd, and demonstrated the ability of these cells to reprogram into patient-specific and disease-specific stem cells.
Abstract: If it were possible to reprogram differentiated human somatic cells into a pluripotent state, patient-specific and disease-specific stem cells could be developed. Previous work generated induced pluripotent stem (iPS) cells capable of germline transmission from murine somatic cells by transd
4,034 citations
TL;DR: It is shown that activation of the canonical Wnt pathway is sufficient to maintain self-renewal of both HESCs and MESCs, and the use of GSK-3-specific inhibitors such as BIO may have practical applications in regenerative medicine.
Abstract: Human and mouse embryonic stem cells (HESCs and MESCs, respectively) self-renew indefinitely while maintaining the ability to generate all three germ-layer derivatives. Despite the importance of ESCs in developmental biology and their potential impact on tissue replacement therapy, the molecular mechanism underlying ESC self-renewal is poorly understood. Here we show that activation of the canonical Wnt pathway is sufficient to maintain self-renewal of both HESCs and MESCs. Although Stat-3 signaling is involved in MESC self-renewal, stimulation of this pathway does not support self-renewal of HESCs. Instead we find that Wnt pathway activation by 6-bromoindirubin-3'-oxime (BIO), a specific pharmacological inhibitor of glycogen synthase kinase-3 (GSK-3), maintains the undifferentiated phenotype in both types of ESCs and sustains expression of the pluripotent state-specific transcription factors Oct-3/4, Rex-1 and Nanog. Wnt signaling is endogenously activated in undifferentiated MESCs and is downregulated upon differentiation. In addition, BIO-mediated Wnt activation is functionally reversible, as withdrawal of the compound leads to normal multidifferentiation programs in both HESCs and MESCs. These results suggest that the use of GSK-3-specific inhibitors such as BIO may have practical applications in regenerative medicine.
2,263 citations
TL;DR: This work generated highly purified human cardiomyocytes using a readily scalable system for directed differentiation that relies on activin A and BMP4, and identified a cocktail of pro-survival factors that limitsCardiomyocyte death after transplantation.
Abstract: Cardiomyocytes derived from human embryonic stem (hES) cells potentially offer large numbers of cells to facilitate repair of the infarcted heart. However, this approach has been limited by inefficient differentiation of hES cells into cardiomyocytes, insufficient purity of cardiomyocyte preparations and poor survival of hES cell-derived myocytes after transplantation. Seeking to overcome these challenges, we generated highly purified human cardiomyocytes using a readily scalable system for directed differentiation that relies on activin A and BMP4. We then identified a cocktail of pro-survival factors that limits cardiomyocyte death after transplantation. These techniques enabled consistent formation of myocardial grafts in the infarcted rat heart. The engrafted human myocardium attenuated ventricular dilation and preserved regional and global contractile function after myocardial infarction compared with controls receiving noncardiac hES cell derivatives or vehicle. The ability of hES cell-derived cardiomyocytes to partially remuscularize myocardial infarcts and attenuate heart failure encourages their study under conditions that closely match human disease.
2,173 citations
TL;DR: Application of a selective Rho-associated kinase (ROCK) inhibitor, Y-27632, to hES cells markedly diminishes dissociation-induced apoptosis, increases cloning efficiency and facilitates subcloning after gene transfer, and enables SFEB-cultured hES Cells to survive and differentiate into Bf1+ cortical and basal telencephalic progenitors.
Abstract: Poor survival of human embryonic stem (hES) cells after cell dissociation is an obstacle to research, hindering manipulations such as subcloning. Here we show that application of a selective Rho-associated kinase (ROCK) inhibitor1,2, Y-27632, to hES cells markedly diminishes dissociation-induced apoptosis, increases cloning efficiency (from ∼1% to ∼27%) and facilitates subcloning after gene transfer. Furthermore, dissociated hES cells treated with Y-27632 are protected from apoptosis even in serum-free suspension (SFEB) culture3 and form floating aggregates. We demonstrate that the protective ability of Y-27632 enables SFEB-cultured hES cells to survive and differentiate into Bf1+ cortical and basal telencephalic progenitors, as do SFEB-cultured mouse ES cells.
2,094 citations