The different shades of mammalian pluripotent stem cells

Abstract

The different shades of mammalian pluripotent stem cells Abstract BACKGROUND Pluripotent stem cells have been derived from a variety of sources such as from the inner cell mass of preimplantation embryos, from primordial germ cells, from teratocarcinomas and from male germ cells. The recent development of induced pluripotent stem cells demonstrates that somatic cells can be reprogrammed to a pluripotent state in vitro. METHODS This review summarizes our current understanding of the origins of mouse and human pluripotent cells. We pay specific attention to transcriptional and epigenetic regulation in pluripotent cells and germ cells. Furthermore, we discuss developmental aspects in the germline that seem to be of importance for the transition of germ cells towards pluripotency. This review is based on literature from the Pubmed database, using Boolean search statements with relevant keywords on the subject. RESULTS There are distinct molecular mechanisms involved in the generation and maintenance of the various pluripotent cell types. Furthermore, there are important similarities and differences between the different categories of pluripotent cells in terms of phenotype and epigenetic modifications. Pluripotent cell lines from various origins differ in growth characteristics, developmental potential, transcriptional activity and epigenetic regulation. Upon derivation, pluripotent stem cells generally acquire new properties, but they often also retain a ‘footprint’ of their tissue of origin. CONCLUSIONS In order to further our knowledge of the mechanisms underlying self-renewal and pluripotency, a thorough comparison between different pluripotent stem cell types is required. This will progress the use of stem cells in basic biology, drug discovery and future clinical applications. Key words pluripotency embryonic stem cells epigenetics germ cells iPS cells Ewart W. Kuijk1,2, Susana M. Chuva de Sousa Lopes3, Niels Geijsen2,4,5, Nick Macklon1,6 and Bernard A.J. Roelen7,* + Author Affiliations 1Department of Reproductive Medicine and Gynaecology, University Medical Center Utrecht, Utrecht, The Netherlands 2Hubrecht Institute-KNAW & University Medical Center Utrecht, Utrecht, The Netherlands 3Department of Anatomy & Embryology, Leiden University Medical Center, Leiden University, Leiden, The Netherlands 4Center for Regenerative Medicine, Harvard Medical School, Massachusetts General Hospital, Boston, MA, USA 5Harvard Stem Cell Institute, Harvard University, Boston, MA, USA 6Division of Developmental Origins of Adult Disease, Department of Obstetrics and Gynaecology, University of Southampton, Princess Anne Hospital, Southampton, UK 7Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 104, 3584 CM Utrecht, The Netherlands *Correspondence address. Tel: +31-30-2533352; Fax: +31-30-2534811; E-mail: b.a.j.roelen@uu.nl Received November 30, 2009. Revision received June 24, 2010. Accepted July 13, 2010. Received November 30, 2009. Revision received June 24, 2010. Accepted July 13, 2010.