Genome-wide analysis of keratinocyte gene expression during their course of differentiation in presence or absence of JNK1,2-deficient or wildtype immortalized mouse embryonic fibroblasts (MEFs)

Analysis of keratinocyte differentiation in presence or absence of fibroblast-derived JNK-dependent soluble factors in vitro. The hypothesis tested in the present study was that JNK-dependent fibroblast-derived soluble factors promote an efficient keratinocyte differentiation. Results provide important information about reduced expression of a subset of differentiation associated genes in keratinocytes in the absence of JNK-dependent fibroblast-derived soluble factors. In vitro transwell co-culture experiments were performed using jnk1-/-jnk2-/- or wildtype immortalized mouse embryonic fibroblasts (MEFs) and differentiating primary normal human epidermal keratinocytes (NHEK) over a time course of 6 days. Total RNA was obtained from NHEK prior to cultivation with MEFs (day 0) and every second day (days 2, 4, and 6) during co-culture. MEFs have been described previously in Sabapathy et al. (2004) Mol Cell 15:713-25.