title: Ultrastructural demonstration of Cx43 gap junctions in induced pluripotent stem cells from human cord blood.
abstract: Gap junction proteins are essential for direct intercellular communication but also influence cellular differentiation and migration. The expression of various connexin gap junction proteins has been demonstrated in embryonic stem cells, with Cx43 being the most intensely studied. As Cx43 is the most prominent gap junction protein in the heart, cardiomyocyte-differentiated stem cells have been studied intensely. To date, however, little is known about the expression and the subcellular distribution of Cx43 in undifferentiated stem cells or about the structural arrangement of channels. We, therefore, here investigate expression of Cx43 in undifferentiated human cord-blood-derived induced pluripotent stem cells (hCBiPS2). For this purpose, we carried out quantitative real-time PCR and immunohistochemistry. For analysis of Cx43 ultrastructure and protein assembly, we performed freeze-fracture replica immunogold labeling (FRIL). Cx43 expression was detected at mRNA and protein level in hCBIPS2 cells. For the first time, ultrastructural data are presented on gap junction morphology in induced pluripotent stem (iPS) cells from cord blood: Our FRIL and electron microscopical analysis revealed the occurrence of gap junction plaques in undifferentiated iPS cells. In addition, these gap junctions were shown to contain the gap junction protein Cx43.
authors.affiliation: Department of Anatomy and Cell Biology, Saarland University, Kirrberger Straße, Building 61, 66421, Homburg/Saar, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Beckmann
authors.affiliation: Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiac, Thoracic, Transplant and Vascular Surgery, Hannover Medical School, 30625, Hannover, Germany.|REBIRTH-Cluster of Excellence, Hannover Medical School, 30625, Hannover, Germany.
authors.forename: Madline
authors.initials: M
authors.lastname: Schubert
authors.affiliation: Department of Anatomy and Cell Biology, Saarland University, Kirrberger Straße, Building 61, 66421, Homburg/Saar, Germany.
authors.forename: Nadine
authors.initials: N
authors.lastname: Hainz
authors.affiliation: Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiac, Thoracic, Transplant and Vascular Surgery, Hannover Medical School, 30625, Hannover, Germany.|REBIRTH-Cluster of Excellence, Hannover Medical School, 30625, Hannover, Germany.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Haase
authors.affiliation: Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiac, Thoracic, Transplant and Vascular Surgery, Hannover Medical School, 30625, Hannover, Germany.|REBIRTH-Cluster of Excellence, Hannover Medical School, 30625, Hannover, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Martin
authors.affiliation: Department of Anatomy and Cell Biology, Saarland University, Kirrberger Straße, Building 61, 66421, Homburg/Saar, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Tschernig
authors.affiliation: Department of Anatomy and Cell Biology, Saarland University, Kirrberger Straße, Building 61, 66421, Homburg/Saar, Germany. carola.meier@uks.eu.
authors.forename: Carola
authors.initials: C
authors.lastname: Meier
mesh_terms: D002478:Cells, Cultured; D018031:Connexin 43 / Q000378:metabolism / Q000648:ultrastructure*; D005312:Fetal Blood / Q000166:cytology* / Q000378:metabolism*; D017629:Gap Junctions / Q000378:metabolism / Q000648:ultrastructure*; D006801:Humans; D057026:Induced Pluripotent Stem Cells / Q000378:metabolism* / Q000648:ultrastructure*
chemical_list: D018031:Connexin 43
keywords: Cx43; Freeze-fracture replica immunogold labeling; iPSC