Stimulation of collagenase synthesis by a 20,000-dalton epithelial cytokine. Evidence for pretranslational regulation.
Certain products of cultured rabbit corneal epithelium or epidermis regulate collagenase production by rabbit corneal stromal cells. Here, we examined the effects of a 20-kDa cytokine derived from cultured epithelium on collagenase expression by normal human skin fibroblasts and by cells from recessive dystrophic epidermolysis bullosa, a disease characterized by over-production of a structurally altered collagenase. Culturing cells for 24 h in the presence of the cytokine resulted in an approximately 2-fold increase in trypsin-activatable collagenase activity paralleled by an increase in immunoreactive protein, suggesting enhanced synthesis. There was no change in the activity/immunoreactive protein, indicating a catalytically unaltered enzyme. In kinetic studies, stimulation of collagenase synthesis was first observed approximately 8 h after exposure to the epidermal cytokine. Conversely, when cells were primed with cytokine for 24 h and the stimulator was then removed, an increased rate of synthesis was seen for an additional approximately 9 h, after which the rate reverted to control levels. Since the kinetic data suggested an effect at a pretranslational level, fibroblasts cultured with 20-kDa stimulator were used to prepare mRNA. In cell-free translation total protein synthesis was unaltered; however, the cytokine caused a greater than 2-fold increase in translatable collagenase mRNA. The data suggest that this epithelial cytokine specifically modulates collagenase synthesis through transcription and that epithelial-stromal interactions are important to cutaneous connective tissue metabolism.
Johnson-Wint
B
B
Bauer
E A
EA
D000818:Animals; D001688:Biological Products / Q000494:pharmacology*; D002478:Cells, Cultured; D016207:Cytokines; D004817:Epidermis / Q000378:metabolism; D004820:Epidermolysis Bullosa / Q000201:enzymology*; D004848:Epithelium / Q000378:metabolism; D005347:Fibroblasts / Q000201:enzymology*; D006801:Humans; D007700:Kinetics; D003012:Microbial Collagenase / Q000096:biosynthesis*; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000096:biosynthesis; D011817:Rabbits; D014158:Transcription, Genetic; D014357:Trypsin / Q000494:pharmacology
D001688:Biological Products; D016207:Cytokines; D012333:RNA, Messenger; D014357:Trypsin; D003012:Microbial Collagenase