title: Effect of 1.2 mmol/l calcium, triamcinolone acetonide, and retinoids on low-calcium regulated keratinocyte differentiation.
abstract: Neonatal mouse keratinocytes cultured in low calcium (0.01 mmol/l) show rapid growth and little stratification when compared with cells grown in normal 1.2 mmol/l calcium. The effect of low calcium on the amount and synthesis of specific differentiation proteins was studied; additionally, the effect of 10(-8) mol/l triamcinolone acetonide, and 6 micrograms/ml of retinoic acid and of etretinate (Ro 10-9359) on low-calcium regulated keratinocyte hyperproliferation and differentiation was determined. Low-calcium regulated keratinocytes contained less non-covalently cross-linked and disulphide cross-linked keratins, less cell envelopes, much greater amounts of SDS-soluble viable cell proteins, and slightly more keratohyaline granule-related proteins than normal-calcium regulated keratinocytes. A 24 h switching time to 1.2 mmol/l calcium medium did not affect the amounts or synthesis of these proteins. Both retinoids and triamcinolone acetonide inhibited by approximately 50% the proliferation of the low-calcium regulated keratinocytes. Growth of low-calcium cells in these drugs for 9 days increased the amounts of both keratins and cell envelope proteins in the cultures. We concluded that calcium-dependent processes can regulate epidermal keratinocyte proliferation and differentiation. Our studies suggest that these calcium-regulated events may occur via changes in calcium-dependent proteins.
mesh_terms: D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D004247:DNA / Q000096:biosynthesis; D004591:Electrophoresis, Polyacrylamide Gel; D005050:Etretinate / Q000494:pharmacology*; D007633:Keratins / Q000096:biosynthesis; D007930:Leucine / Q000378:metabolism; D051379:Mice; D014176:Protein Biosynthesis; D012867:Skin / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D013936:Thymidine / Q000378:metabolism; D014212:Tretinoin / Q000494:pharmacology*; D014222:Triamcinolone Acetonide / Q000494:pharmacology*
chemical_list: D014212:Tretinoin; D005050:Etretinate; D007633:Keratins; D004247:DNA; D014222:Triamcinolone Acetonide; D007930:Leucine; D002118:Calcium; D013936:Thymidine