title: Non-integrating episomal plasmid-based reprogramming of human amniotic fluid stem cells into induced pluripotent stem cells in chemically defined conditions.
abstract: Amniotic fluid stem cells (AFSC) represent an attractive potential cell source for fetal and pediatric cell-based therapies. However, upgrading them to pluripotency confers refractoriness toward senescence, higher proliferation rate and unlimited differentiation potential. AFSC were observed to rapidly and efficiently reacquire pluripotency which together with their easy recovery makes them an attractive cell source for reprogramming. The reprogramming process as well as the resulting iPSC epigenome could potentially benefit from the unspecialized nature of AFSC. iPSC derived from AFSC also have potential in disease modeling, such as Down syndrome or β-thalassemia. Previous experiments involving AFSC reprogramming have largely relied on integrative vector transgene delivery and undefined serum-containing, feeder-dependent culture. Here, we describe non-integrative oriP/EBNA-1 episomal plasmid-based reprogramming of AFSC into iPSC and culture in fully chemically defined xeno-free conditions represented by vitronectin coating and E8 medium, a system that we found uniquely suited for this purpose. The derived AF-iPSC lines uniformly expressed a set of pluripotency markers Oct3/4, Nanog, Sox2, SSEA-1, SSEA-4, TRA-1-60, TRA-1-81 in a pattern typical for human primed PSC. Additionally, the cells formed teratomas, and were deemed pluripotent by PluriTest, a global expression microarray-based in-silico pluripotency assay. However, we found that the PluriTest scores were borderline, indicating a unique pluripotent signature in the defined condition. In the light of potential future clinical translation of iPSC technology, non-integrating reprogramming and chemically defined culture are more acceptable.
authors.affiliation: a Swiss Center for Regenerative Medicine, University and University Hospital of Zurich , Zurich , Switzerland.|b Division of Surgical Research, University Hospital Zurich , Zurich , Switzerland.|c Clinic for Cardiovascular Surgery, University Hospital Zurich , Zurich , Switzerland.|d Mitchell Cancer Institute, University of South Alabama , Mobile , AL , USA.|e Research Institute for Animal Production Nitra, National Agricultural and Food Center , Nitra , Slovak Republic.
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Slamecka
authors.affiliation: a Swiss Center for Regenerative Medicine, University and University Hospital of Zurich , Zurich , Switzerland.|b Division of Surgical Research, University Hospital Zurich , Zurich , Switzerland.|c Clinic for Cardiovascular Surgery, University Hospital Zurich , Zurich , Switzerland.|f School of Life Sciences, École Polytechnique Federale de Lausanne , Lausanne , Switzerland.
authors.forename: Lilia
authors.initials: L
authors.lastname: Salimova
authors.affiliation: d Mitchell Cancer Institute, University of South Alabama , Mobile , AL , USA.
authors.forename: Steven
authors.initials: S
authors.lastname: McClellan
authors.affiliation: a Swiss Center for Regenerative Medicine, University and University Hospital of Zurich , Zurich , Switzerland.|b Division of Surgical Research, University Hospital Zurich , Zurich , Switzerland.|c Clinic for Cardiovascular Surgery, University Hospital Zurich , Zurich , Switzerland.|g Department of Biomedical Engineering , Eindhoven University of Technology , Eindhoven , The Netherlands.
authors.forename: Mathieu
authors.initials: M
authors.lastname: van Kelle
authors.affiliation: a Swiss Center for Regenerative Medicine, University and University Hospital of Zurich , Zurich , Switzerland.|b Division of Surgical Research, University Hospital Zurich , Zurich , Switzerland.|c Clinic for Cardiovascular Surgery, University Hospital Zurich , Zurich , Switzerland.
authors.forename: Debora
authors.initials: D
authors.lastname: Kehl
authors.affiliation: h College of Medicine, University of South Alabama , Mobile , AL , USA.
authors.forename: Javier
authors.initials: J
authors.lastname: Laurini
authors.affiliation: i Institute of Laboratory Animal Science, University of Zurich , Zurich , Switzerland.|j Center for Applied Biotechnology and Molecular Medicine, University of Zurich , Zurich , Switzerland.|k Division of Trauma Surgery, Center for Clinical Research, University Hospital Zurich , Zurich , Switzerland.
authors.forename: Paolo
authors.initials: P
authors.lastname: Cinelli
authors.affiliation: d Mitchell Cancer Institute, University of South Alabama , Mobile , AL , USA.
authors.forename: Laurie
authors.initials: L
authors.lastname: Owen
authors.affiliation: a Swiss Center for Regenerative Medicine, University and University Hospital of Zurich , Zurich , Switzerland.|b Division of Surgical Research, University Hospital Zurich , Zurich , Switzerland.|c Clinic for Cardiovascular Surgery, University Hospital Zurich , Zurich , Switzerland.
authors.forename: Simon P
authors.initials: SP
authors.lastname: Hoerstrup
authors.affiliation: a Swiss Center for Regenerative Medicine, University and University Hospital of Zurich , Zurich , Switzerland.|b Division of Surgical Research, University Hospital Zurich , Zurich , Switzerland.|c Clinic for Cardiovascular Surgery, University Hospital Zurich , Zurich , Switzerland.|l Department of Dermatology and Venerology , University Hospital Zurich , Zurich , Switzerland.
authors.forename: Benedikt
authors.initials: B
authors.lastname: Weber
mesh_terms: D000653:Amniotic Fluid / Q000166:cytology / Q000187:drug effects; D000954:Antigens, Surface / Q000235:genetics / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D018929:Cell Culture Techniques; D002454:Cell Differentiation; D049109:Cell Proliferation; D065150:Cellular Reprogramming; D003470:Culture Media / Q000494:pharmacology; D015870:Gene Expression; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D057026:Induced Pluripotent Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D016256:Lewis X Antigen / Q000235:genetics / Q000378:metabolism; D000071317:Nanog Homeobox Protein; D050814:Octamer Transcription Factor-3 / Q000235:genetics / Q000378:metabolism; D010957:Plasmids / Q000737:chemistry* / Q000378:metabolism; D040081:Protein Array Analysis; D011509:Proteoglycans / Q000235:genetics / Q000378:metabolism; D055748:SOXB1 Transcription Factors / Q000235:genetics / Q000378:metabolism; D055746:Stage-Specific Embryonic Antigens / Q000235:genetics / Q000378:metabolism; D014162:Transfection / Q000379:methods*
chemical_list: D000954:Antigens, Surface; D015415:Biomarkers; D003470:Culture Media; D018398:Homeodomain Proteins; D016256:Lewis X Antigen; C486780:NANOG protein, human; D000071317:Nanog Homeobox Protein; D050814:Octamer Transcription Factor-3; C494173:POU5F1 protein, human; D011509:Proteoglycans; C527782:SOX2 protein, human; D055748:SOXB1 Transcription Factors; D055746:Stage-Specific Embryonic Antigens; C107064:TRA-1-60 antigen, human; C519803:TRA-1-81 antigen, human; C066584:stage-specific embryonic antigen-4
keywords: E8; PluriTest; amniotic fluid stem cells; episomal reprogramming; induced pluripotent stem cells; vitronectin; xeno-free culture