title: Rat embryonic fibroblasts improve reprogramming of human keratinocytes into induced pluripotent stem cells.
abstract: Patient-specific human induced pluripotent stem (hiPS) cells not only provide a promising tool for cellular disease models in general, but also open up the opportunity to establish cell-type-specific systems for personalized medicine. One of the crucial prerequisites for these strategies, however, is a fast and efficient reprogramming strategy from easy accessible somatic cell populations. Keratinocytes from plucked human hair had been introduced as a superior cell source for reprogramming purposes compared with the widely used skin fibroblasts. The starting cell population is, however, limited and thereby further optimization in terms of time, efficiency, and quality is inevitable. Here we show that rat embryonic fibroblasts (REFs) should replace mouse embryonic fibroblasts as feeder cells in the reprogramming process. REFs enable a significantly more efficient reprogramming procedure as shown by colony number and total amount of SSEA4-positive cells. We successfully produced keratinocyte-derived hiPS (k-hiPS) cells from various donors. The arising k-hiPS cells display the hallmarks of pluripotency such as expression of stem cell markers and differentiation into all 3 germ layers. The increased reprogramming efficiency using REFs as a feeder layer occurred independent of the proliferation rate in the parental keratinocytes and acts, at least in part, in a non-cell autonomous way by secreting factors known to facilitate pluripotency such as Tgfb1, Inhba and Grem1. Hence, we provide an easy to use and highly efficient reprogramming system that could be very useful for a broad application to generate human iPS cells.
authors.affiliation: Institute for Anatomy and Cell Biology, Ulm University, Ulm, Germany.
authors.forename: Leonhard
authors.initials: L
authors.lastname: Linta
authors.forename: Marianne
authors.initials: M
authors.lastname: Stockmann
authors.forename: Karin N
authors.initials: KN
authors.lastname: Kleinhans
authors.forename: Anja
authors.initials: A
authors.lastname: Böckers
authors.forename: Alexander
authors.initials: A
authors.lastname: Storch
authors.forename: Holm
authors.initials: H
authors.lastname: Zaehres
authors.forename: Qiong
authors.initials: Q
authors.lastname: Lin
authors.forename: Gotthold
authors.initials: G
authors.lastname: Barbi
authors.forename: Tobias M
authors.initials: TM
authors.lastname: Böckers
authors.forename: Alexander
authors.initials: A
authors.lastname: Kleger
authors.forename: Stefan
authors.initials: S
authors.lastname: Liebau
mesh_terms: D000818:Animals; D065150:Cellular Reprogramming; D053595:Embryonic Stem Cells / Q000166:cytology*; D005347:Fibroblasts / Q000166:cytology*; D006801:Humans; D057026:Induced Pluripotent Stem Cells / Q000166:cytology*; D015603:Keratinocytes / Q000166:cytology*; D008722:Methods; D051379:Mice; D051381:Rats