| description |
Adult stem cells are a focus of research in developmental skin biology and skin carcinogenesis attributable tobecause of their life-long pivotalcritical role in epidermal renewal. This study aimed at a thorough transcriptional characterization of stem cells carrying the Lgr6 receptor (cofactor of Frizzled in Wnt signaling). We used quantitative RNA deep seq and gene set enrichment analysis on α6+/Lgr6- and α6+/Lgr6+ epidermal basal (α6+) cells. These basal cells were isolated from epidermal sheets of transgenic hairless mice containing the Lgr6-EGFP-Ires-CreERT2/R26R-LacZ cassettes (Tg/Tg and Tg/wt) by flow cytometric sorting on EGFP fluorescence.Epidermal cell suspensions were prepared from transgenic hairless mouse strains containing the Lgr6-EGFP-Ires-CreERT2/R26R-LacZ cassettes (Tg/Tg and Tg/wt). Basal cells (integrin α6+) were sorted by EGFP expression (Lgr6+ vs -). Quantitative RNA deep seq and gene set enrichment analysis was performed on α6+/Lgr6- and α6+/Lgr6+ cells.We demonstrated that this approach permits isolation of cells expressing the cassette with a high purity in isolating cells that transcribe the cassette, and identified a collection of protein encoding genes as well as non-coding RNAs differentially expressed between Lgr6+ and Lgr6-these basal cells (Tg/wt) types. In addition, we discovered that in presumed Lgr6-null mice (Tg/Tg), a Lgr6 isoform (delta-Lgr6) is transcribed encoding a protein isoform lacking 75 N-terminal amino acids (delta-Lgr6). Evidence for the existence of a human orthologue (delta-LGR6) was found by screening a proteome database. Thus, we have established in Lgr6+ cells a RNA expression profile characteristic of cancer-related pathways and stem cells, and identified a set of genes co-expressed with Lgr6 which may serve further (functional) characterization and identification of these cells, also in human skin. |