| First Author | Zhu S | Year | 1999 |
| Journal | Mol Cell Biol | Volume | 19 |
| Issue | 10 | Pages | 7181-90 |
| PubMed ID | 10490653 | Mgi Jnum | J:119890 |
| Mgi Id | MGI:3703419 | Doi | 10.1128/mcb.19.10.7181 |
| Citation | Zhu S, et al. (1999) C/EBPbeta modulates the early events of keratinocyte differentiation involving growth arrest and keratin 1 and keratin 10 expression. Mol Cell Biol 19(10):7181-90 |
| abstractText | The epidermis is a stratified squamous epithelium composed primarily of keratinocytes that become postmitotic and undergo sequential changes in gene expression during terminal differentiation. The expression of the transcription factor CCAAT/enhancer binding protein beta (C/EBPbeta) within mouse epidermis and primary keratinocytes has recently been described; however, the function of C/EBPbeta within the epidermal keratinocyte is unknown. We report here that transient transfection of mouse primary keratinocytes with a C/EBP-responsive promoter-reporter construct resulted in a sevenfold increase in luciferase activity when keratinocytes were switched to culture conditions that induce growth arrest and differentiation. Forced expression of C/EBPbeta in BALB/MK2 keratinocytes inhibited growth, induced morphological changes consistent with a more differentiated phenotype, and upregulated two early markers of differentiation, keratin 1 (K1) and keratin 10 (K10) but had a minimal effect on the expression of late-stage markers, loricrin and involucrin. Analysis of the epidermis of C/EBPbeta-deficient mice revealed a mild epidermal hyperplasia and decreased expression of K1 and K10 but not of involucrin and loricrin. C/EBPbeta-deficient primary keratinocytes were partially resistant to calcium-induced growth arrest. Analysis of terminally differentiated spontaneously detached keratinocytes or those induced to differentiate by suspension culture revealed that C/EBPbeta-deficient keratinocytes displayed striking decreases in K1 and K10, while expression of later-stage markers was only minimally altered. Our results demonstrate that C/EBPbeta plays an important role in the early events of stratified squamous differentiation in keratinocytes involving growth arrest and K1 and K10 expression. |
