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Contribution of Sp1 to Telomerase Expression and Activity in Skin Keratinocytes Cultured With a Feeder Layer
Author(s) -
Bisson Francis,
Paquet Claudie,
Bourget JeanMichel,
Zaniolo Karine,
Rochette Patrick J.,
Landreville Solange,
Damour Odile,
Boudreau François,
Auger François A.,
Guérin Sylvain L.,
Germain Lucie
Publication year - 2015
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.24706
Subject(s) - telomerase , telomerase reverse transcriptase , microbiology and biotechnology , biology , cell culture , keratinocyte , rna interference , transcription factor , gene expression , rna , gene , genetics
The growth of primary keratinocytes is improved by culturing them with a feeder layer. The aim of this study was to assess whether the feeder layer increases the lifespan of cultured epithelial cells by maintaining or improving telomerase activity and expression. The addition of an irradiated fibroblast feeder layer of either human or mouse origin (i3T3) helped maintain telomerase activity as well as expression of the transcription factor Sp1 in cultured keratinocytes. In contrast, senescence occurred earlier, together with a reduction of Sp1 expression and telomerase activity, in keratinocytes cultured without a feeder layer. Telomerase activity was consistently higher in keratinocytes grown on the three different feeder layers tested relative to cells grown without them. Suppression of Sp1 expression by RNA inhibition (RNAi) reduced both telomerase expression and activity in keratinocytes and also abolished their long‐term growth capacity suggesting that Sp1 is a key regulator of both telomerase gene expression and cell cycle progression of primary cultured human skin keratinocytes. The results of the present study therefore suggest that the beneficial influence of the feeder layer relies on its ability to preserve telomerase activity in cultured human keratinocytes through the maintenance of stable levels of Sp1 expression. J. Cell. Physiol. 230: 308–317, 2015. © 2014 Wiley Periodicals, Inc.