Talk:Stem Cells - Induced
Li L, Li Y, Sottas C, Culty M, Fan J, Hu Y, Cheung G, Chemes HE & Papadopoulos V. (2019). Directing differentiation of human induced pluripotent stem cells toward androgen-producing Leydig cells rather than adrenal cells. Proc. Natl. Acad. Sci. U.S.A. , 116, 23274-23283. PMID: 31591190 DOI.
Abstract Reduced serum testosterone (T), or hypogonadism, affects millions of men and is associated with many pathologies, including infertility, cardiovascular diseases, metabolic syndrome, and decreased libido and sexual function. Administering T-replacement therapy (TRT) reverses many of the symptoms associated with low T levels. However, TRT is linked to side effects such as infertility and increased risk of prostate cancer and cardiovascular diseases. Thus, there is a need to obtain T-producing cells that could be used to treat hypogonadism via transplantation and reestablishment of T-producing cell lineages in the body. T is synthesized by Leydig cells (LCs), proposed to derive from mesenchymal cells of mesonephric origin. Although mesenchymal cells have been successfully induced into LCs, the limited source and possible trauma to donors hinders their application to clinical therapies. Alternatively, human induced pluripotent stem cells (hiPSCs), which are expandable in culture and have the potential to differentiate into all somatic cell types, have become the emerging source of autologous cell therapies. We have successfully induced the differentiation of hiPSCs into either human Leydig-like (hLLCs) or adrenal-like cells (hALCs) using chemically defined culture conditions. Factors critical for the development of LCs were added to both culture systems. hLLCs expressed all steroidogenic genes and proteins important for T biosynthesis, synthesized T rather than cortisol, secreted steroid hormones in response to dibutyryl-cAMP and 22(R)-hydroxycholesterol, and displayed ultrastructural features resembling LCs. By contrast, hALCs synthesized cortisol rather than T. The success in generating hiPSC-derived hLLCs with broad human LC (hLC) features supports the potential for hiPSC-based hLC regeneration. KEYWORDS: differentiation; human Leydig cells; human induced pluripotent stem cells; steroidogenesis; testosterone PMID: 31591190 DOI: 10.1073/pnas.1908207116
Distinct SoxB1 networks are required for naïve and primed pluripotency
Elife. 2017 Dec 19;6. pii: e27746. doi: 10.7554/eLife.27746.
Corsinotti A1,2, Wong FC1, Tatar T1, Szczerbinska I1, Halbritter F1, Colby D1, Gogolok S1, Pantier R1, Liggat K1, Mirfazeli ES1, Hall-Ponsele E1, Mullin NP1, Wilson V1, Chambers I1.
Deletion of Sox2 from mouse embryonic stem cells (ESCs) causes trophectodermal differentiation. While this can be prevented by enforced expression of the related SOXB1 proteins, SOX1 or SOX3, the roles of SOXB1 proteins in epiblast stem cell (EpiSC) pluripotency are unknown. Here, we show that Sox2 can be deleted from EpiSCs with impunity. This is due to a shift in the balance of SoxB1 expression in EpiSCs, which have decreased Sox2 and increased Sox3 compared to ESCs. Consistent with functional redundancy, Sox3 can also be deleted from EpiSCs without eliminating self-renewal. However, deletion of both Sox2 and Sox3 prevents self-renewal. The overall SOXB1 levels in ESCs affect differentiation choices: neural differentiation of Sox2 heterozygous ESCs is compromised, while increased SOXB1 levels divert the ESC to EpiSC transition towards neural differentiation. Therefore, optimal SOXB1 levels are critical for each pluripotent state and for cell fate decisions during exit from naïve pluripotency. KEYWORDS: Embryonic stem cells; Epiblast stem cells; Pluripotency; Sox; developmental biology; mouse; stem cells; transcription factors PMID: 29256862 PMCID: PMC5758114 DOI: 10.7554/eLife.27746
Characterization and therapeutic potential of induced pluripotent stem cell-derived cardiovascular progenitor cells
PLoS One. 2012;7(10):e45603. doi: 10.1371/journal.pone.0045603. Epub 2012 Oct 9.
Nsair A, Schenke-Layland K, Van Handel B, Evseenko D, Kahn M, Zhao P, Mendelis J, Heydarkhan S, Awaji O, Vottler M, Geist S, Chyu J, Gago-Lopez N, Crooks GM, Plath K, Goldhaber J, Mikkola HK, Maclellan WR. Source Department of Medicine and Physiology, Cardiovascular Research Laboratory, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America ; The Edythe and Eli Broad Center for Regenerative Medicine and Stem Cell Research, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America.
BACKGROUND: Cardiovascular progenitor cells (CPCs) have been identified within the developing mouse heart and differentiating pluripotent stem cells by intracellular transcription factors Nkx2.5 and Islet 1 (Isl1). Study of endogenous and induced pluripotent stem cell (iPSC)-derived CPCs has been limited due to the lack of specific cell surface markers to isolate them and conditions for their in vitro expansion that maintain their multipotency. METHODOLOGY/PRINCIPAL FINDINGS: We sought to identify specific cell surface markers that label endogenous embryonic CPCs and validated these markers in iPSC-derived Isl1(+)/Nkx2.5(+) CPCs. We developed conditions that allow propagation and characterization of endogenous and iPSC-derived Isl1(+)/Nkx2.5(+) CPCs and protocols for their clonal expansion in vitro and transplantation in vivo. Transcriptome analysis of CPCs from differentiating mouse embryonic stem cells identified a panel of surface markers. Comparison of these markers as well as previously described surface markers revealed the combination of Flt1(+)/Flt4(+) best identified and facilitated enrichment for Isl1(+)/Nkx2.5(+) CPCs from embryonic hearts and differentiating iPSCs. Endogenous mouse and iPSC-derived Flt1(+)/Flt4(+) CPCs differentiated into all three cardiovascular lineages in vitro. Flt1(+)/Flt4(+) CPCs transplanted into left ventricles demonstrated robust engraftment and differentiation into mature cardiomyocytes (CMs). CONCLUSION/SIGNIFICANCE: The cell surface marker combination of Flt1 and Flt4 specifically identify and enrich for an endogenous and iPSC-derived Isl1(+)/Nkx2.5(+) CPC with trilineage cardiovascular potential in vitro and robust ability for engraftment and differentiation into morphologically and electrophysiologically mature adult CMs in vivo post transplantation into adult hearts.
The tumorigenicity of human embryonic and induced pluripotent stem cells
Nat Rev Cancer. 2011 Apr;11(4):268-77. Epub 2011 Mar 10.
Ben-David U, Benvenisty N. Source Stem Cell Unit, Department of Genetics, Silberman Institute of Life Sciences, The Hebrew University, Jerusalem 91904, Israel.
The unique abilities of human pluripotent stem cells to self-renew and to differentiate into cells of the three germ layers make them an invaluable tool for the future of regenerative medicine. However, the same properties also make them tumorigenic, and therefore hinder their clinical application. Hence, the tumorigenicity of human embryonic stem cells (HESCs) has been extensively studied. Until recently, it was assumed that human induced pluripotent stem cells (HiPSCs) would behave like their embryonic counterparts in respect to their tumorigenicity. However, a rapidly accumulating body of evidence suggests that there are important genetic and epigenetic differences between these two cell types, which seem to influence their tumorigenicity.
PMID: 21390058 http://www.ncbi.nlm.nih.gov/pubmed/21390058
Interplay of Oct4 with Sox2 and Sox17: a molecular switch from stem cell pluripotency to specifying a cardiac fate
J Cell Biol. 2009 Sep 7;186(5):665-73.
Stefanovic S, Abboud N, Désilets S, Nury D, Cowan C, Pucéat M. Source Institut National de la Santé et de la Recherche Médicale (INSERM), Avenir Team, Stem Cells and Cardiogenesis, Evry 91058, France.
Oct4 exerts a dose-dependent dual action, as both a gatekeeper for stem cell pluripotency and in driving cells toward specific lineages. Here, we identify the molecular mechanism underlying this dual function. BMP2- or transgene-induced Oct4 up-regulation drives human embryonic and induced pluripotent stem cells to become cardiac progenitors. When embryonic stem cell pluripotency is achieved, Oct4 switches from the Sox2 to the Sox17 promoter. This switch allows the cells to turn off the pluripotency Oct4-Sox2 loop and to turn on the Sox17 promoter. This powerful process generates a subset of endoderm-expressing Sox17 and Hex, both regulators of paracrine signals for cardiogenesis (i.e., Wnt, BMP2) released into the medium surrounding colonies of embryonic stem cells. Our data thus reveal a novel molecular Oct4- and Sox17-mediated mechanism that disrupts the stem cell microenvironment favoring pluripotency to provide a novel paracrine endodermal environment in which cell lineage is determined and commits the cells to a cardiogenic fate.
PMID: 19736317 http://www.ncbi.nlm.nih.gov/pubmed/19736317?
Direct cell reprogramming is a stochastic process amenable to acceleration
Nature. 2009 Dec 3;462(7273):595-601. Epub 2009 Nov 8.
Hanna J, Saha K, Pando B, van Zon J, Lengner CJ, Creyghton MP, van Oudenaarden A, Jaenisch R. Source The Whitehead Institute for Biomedical Research, Cambridge, Massachusetts 02142, USA. Hanna@wi.mit.edu
Direct reprogramming of somatic cells into induced pluripotent stem (iPS) cells can be achieved by overexpression of Oct4, Sox2, Klf4 and c-Myc transcription factors, but only a minority of donor somatic cells can be reprogrammed to pluripotency. Here we demonstrate that reprogramming by these transcription factors is a continuous stochastic process where almost all mouse donor cells eventually give rise to iPS cells on continued growth and transcription factor expression. Additional inhibition of the p53/p21 pathway or overexpression of Lin28 increased the cell division rate and resulted in an accelerated kinetics of iPS cell formation that was directly proportional to the increase in cell proliferation. In contrast, Nanog overexpression accelerated reprogramming in a predominantly cell-division-rate-independent manner. Quantitative analyses define distinct cell-division-rate-dependent and -independent modes for accelerating the stochastic course of reprogramming, and suggest that the number of cell divisions is a key parameter driving epigenetic reprogramming to pluripotency.
PMID: 19898493 http://www.ncbi.nlm.nih.gov/pubmed/19898493
Regulation of stem cell pluripotency and differentiation involves a mutual regulatory circuit of the NANOG, OCT4, and SOX2 pluripotency transcription factors with polycomb repressive complexes and stem cell microRNAs
Stem Cells Dev. 2009 Sep;18(7):1093-108.
Kashyap V, Rezende NC, Scotland KB, Shaffer SM, Persson JL, Gudas LJ, Mongan NP. Source Department of Pharmacology, Graduate Programs in Pharmacology, Weill Cornell Medical College, New York, New York 10065, USA.
Coordinated transcription factor networks have emerged as the master regulatory mechanisms of stem cell pluripotency and differentiation. Many stem cell-specific transcription factors, including the pluripotency transcription factors, OCT4, NANOG, and SOX2 function in combinatorial complexes to regulate the expression of loci, which are involved in embryonic stem (ES) cell pluripotency and cellular differentiation. This review will address how these pathways form a reciprocal regulatory circuit whereby the equilibrium between stem cell self-renewal, proliferation, and differentiation is in perpetual balance. We will discuss how distinct epigenetic repressive pathways involving polycomb complexes, DNA methylation, and microRNAs cooperate to reduce transcriptional noise and to prevent stochastic and aberrant induction of differentiation. We will provide a brief overview of how these networks cooperate to modulate differentiation along hematopoietic and neuronal lineages. Finally, we will describe how aberrant functioning of components of the stem cell regulatory network may contribute to malignant transformation of adult stem cells and the establishment of a "cancer stem cell" phenotype and thereby underlie multiple types of human malignancies.
PMID: 19480567 http://www.ncbi.nlm.nih.gov/pubmed/19480567
Pluripotent stem cells induced from adult neural stem cells by reprogramming with two factors
Nature. 2008 Jul 31;454(7204):646-50. Epub 2008 Jun 29.
Kim JB, Zaehres H, Wu G, Gentile L, Ko K, Sebastiano V, Araúzo-Bravo MJ, Ruau D, Han DW, Zenke M, Schöler HR. Source Department of Cell and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Röntgenstrasse 20, 48149 Münster, NRW, Germany.
Reprogramming of somatic cells is a valuable tool to understand the mechanisms of regaining pluripotency and further opens up the possibility of generating patient-specific pluripotent stem cells. Reprogramming of mouse and human somatic cells into pluripotent stem cells, designated as induced pluripotent stem (iPS) cells, has been possible with the expression of the transcription factor quartet Oct4 (also known as Pou5f1), Sox2, c-Myc and Klf4 (refs 1-11). Considering that ectopic expression of c-Myc causes tumorigenicity in offspring and that retroviruses themselves can cause insertional mutagenesis, the generation of iPS cells with a minimal number of factors may hasten the clinical application of this approach. Here we show that adult mouse neural stem cells express higher endogenous levels of Sox2 and c-Myc than embryonic stem cells, and that exogenous Oct4 together with either Klf4 or c-Myc is sufficient to generate iPS cells from neural stem cells. These two-factor iPS cells are similar to embryonic stem cells at the molecular level, contribute to development of the germ line, and form chimaeras. We propose that, in inducing pluripotency, the number of reprogramming factors can be reduced when using somatic cells that endogenously express appropriate levels of complementing factors.
Characterization of stage-specific embryonic antigen-1 expression during early stages of human embryogenesis
Oncol Rep. 2004 Dec;12(6):1251-6.
Liu S, Liu H, Tang S, Pan Y, Ji K, Ning H, Wang S, Qi Z, Li L. Source Department of Histology and Embryology, Second Military Medical University, Shanghai 200433, PR China.
Extensive expression of stage-specific embryonic antigen-1 (SSEA-1) has been documented in some animal species, but not in human embryos. In this study, SSEA-1 was detected during human embryogenesis by whole-mount immunohistochemistry. Alkaline phosphatase (Ap) activity was detected to identify human primordial germ cells. SSEA-1 was expressed steadily and restrictedly in some cells/tissues, especially in the nephric duct and nephric tubule (including the pronephric duct and tubule, mesonephric duct and tubule, metanephric tissues) besides embryonic ectodermal cells and yolk sac from 3 to 7 weeks. High level of Ap activity was observed in vessels, part of the mesonephric duct, especially in embryonic primordial germ cells localized in the yolk sac, primitive gut, dorsal mesenteries and genital ridges. No colocalization of AP and SSEA-1 cells was observed. SSEA-1 was expressed in human embryos in a different pattern at early stages compared to that in mouse embryos. It was expressed in the nephric duct, nephric tubule, yolk sac and on the surface of embryonic ectodermal cells of the epidermis, but not in human primordial germ cells.
PMID: 15547746 http://www.ncbi.nlm.nih.gov/pubmed/15547746