Open AccessSkin keratinocytes pre‐treated with embryonic stem cell‐conditioned medium or BMP4 can be directed to an alternative cell lineage
Author(s) -
Grinnell K. L.,
Bickenbach J. R.
Publication year - 2007
Publication title -
cell proliferation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.647
H-Index - 74
eISSN - 1365-2184
pISSN - 0960-7722
DOI - 10.1111/j.1365-2184.2007.00464.x
Subject(s) - embryonic stem cell , keratinocyte , reprogramming , microbiology and biotechnology , biology , stem cell , homeobox protein nanog , population , cellular differentiation , bone morphogenetic protein 4 , cell culture , cell , induced pluripotent stem cell , genetics , medicine , environmental health , gene
. Objectives : In this study, we have investigated whether secreted factors from embryonic stem cells (ESCs) could reprogramme keratinocytes and increase their potential to be directed into alternative cell lineages. Materials and methods : Contact and non‐contact co‐cultures of skin keratinocytes and murine ESCs were used initially to confirm any reprogramming ability of ESC‐conditioned medium (CM). Immunofluoresence was used to assess nuclear expression of octamer‐4 (Oct‐4), as well as to confirm neuronal protein expression in neuroectodermally directed keratinocytes. Transcript expression changes were evaluated using semiquantitative reverse transcription‐polymerase chain reaction. Western blotting, accompanied by densitometry analysis, was used to evaluate protein expression following morphology changes. Results : We found that keratinocytes treated with ESC‐CM changed their morphology and were stimulated to express the pluripotency regulator, Oct‐4 , and its target transcripts, Sox‐2 , Nanog , Utf1 and Rex‐1 . We demonstrate that at least one of the reprogramming factors is bone morphogenetic factor‐4 (BMP4). Pre‐treated keratinocytes could be specifically directed to differentiate into cells of the neuronal lineage. The majority of responsive keratinocytes were the epidermal stem cell population, with a small percentage of transit‐amplifying cells also being affected. Conclusions : Our results suggest that ESC‐CM contains a number of factors, including BMP4, which are capable of reprogramming mouse skin keratinocytes to make them more developmentally potent, as evidenced by their ability to be re‐differentiated into cells of the neuronal lineage. Our findings also imply a continuum of differentiation within the basal keratinocyte population. An increase in developmental potential combined with directed differentiation could increase the therapeutic relevancy of somatic cells.