Biomaterial Database

Regulation and inhibition of collagenase expression by long-wavelength ultraviolet radiation in cultured human skin fibroblasts. 1995

M Petersen, and T Hamilton, and H L Li

Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City 84132, USA.

The cellular mechanisms responsible for the connective tissue changes produced by chronic exposure to UV light are poorly understood. Collagenase, a metalloproteinase, initiates degradation of types I and III collagen and thus plays a key role in the remodeling of dermal collagen. Collagenase synthesis by fibroblasts and keratinocytes involves the protein kinase C (PKC) second messenger system, and corticosteroids have been shown to suppress its synthesis at the level of gene transcription. Long-wavelength UV light (UVA, 320-400 nm) stimulates the synthesis of interstitial collagenase, as well as increasing PKC activity, in human skin fibroblasts in vitro. This study explores the regulation of collagenase expression by UVA in cultured human skin fibroblasts. Specifically, the time course, the effect of actinomycin D, an inhibitor of RNA synthesis, as well as the effect of PKC inhibitors and dexamethasone on expression of collagenase following UVA irradiation were examined. After UVA irradiation, collagenase mRNA rose rapidly between 4 and 12 h postirradiation, peaking 18 h post-UVA. Actinomycin D completely suppressed the UVA-induced increase in collagenase mRNA. Thus, new RNA synthesis is required for the UVA-induced increase in collagenase mRNA. The PKC inhibitor, H-7, blocked the increase in collagenase mRNA in response to UVA in a dose-dependent manner. Similarly, dexamethasone also inhibited collagenase gene expression induced by UVA in a dose-dependent fashion; the majority of the inhibitory effect was seen within the first 4 h after irradiation. These studies demonstrate that the effect of UVA on collagenase gene expression is regulated at the pretranscriptional level and may involve the PKC pathway.

UI	MeSH Term	Description	Entries
D002478	Cells, Cultured	Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.	Cultured Cells,Cell, Cultured,Cultured Cell
D004790	Enzyme Induction	An increase in the rate of synthesis of an enzyme due to the presence of an inducer which acts to derepress the gene responsible for enzyme synthesis.	Induction, Enzyme
D005347	Fibroblasts	Connective tissue cells which secrete an extracellular matrix rich in collagen and other macromolecules.	Fibroblast
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D012867	Skin	The outer covering of the body that protects it from the environment. It is composed of the DERMIS and the EPIDERMIS.
D014466	Ultraviolet Rays	That portion of the electromagnetic spectrum immediately below the visible range and extending into the x-ray frequencies. The longer wavelengths (near-UV or biotic or vital rays) are necessary for the endogenous synthesis of vitamin D and are also called antirachitic rays; the shorter, ionizing wavelengths (far-UV or abiotic or extravital rays) are viricidal, bactericidal, mutagenic, and carcinogenic and are used as disinfectants.	Actinic Rays,Black Light, Ultraviolet,UV Light,UV Radiation,Ultra-Violet Rays,Ultraviolet Light,Ultraviolet Radiation,Actinic Ray,Light, UV,Light, Ultraviolet,Radiation, UV,Radiation, Ultraviolet,Ray, Actinic,Ray, Ultra-Violet,Ray, Ultraviolet,Ultra Violet Rays,Ultra-Violet Ray,Ultraviolet Black Light,Ultraviolet Black Lights,Ultraviolet Radiations,Ultraviolet Ray
D017364	Collagenases	Enzymes that catalyze the degradation of collagen by acting on the peptide bonds.	Collagen Peptidase,Collagen-Degrading Enzyme,Collagenase,Collagen Degrading Enzyme,Peptidase, Collagen
D061965	Matrix Metalloproteinase Inhibitors	Compounds that inhibit the enzyme activity or activation of MATRIX METALLOPROTEINASES.	Collagenase Inhibitor,Gelatinase Inhibitor,MMP Inhibitor,Matrix Metalloproteinase Inhibitor,Collagenase Inhibitors,Gelatinase Inhibitors,MMP Inhibitors,Stromelysin Inhibitors,Inhibitor, Collagenase,Inhibitor, Gelatinase,Inhibitor, MMP,Inhibitor, Matrix Metalloproteinase,Inhibitors, Collagenase,Inhibitors, Gelatinase,Inhibitors, MMP,Inhibitors, Matrix Metalloproteinase,Inhibitors, Stromelysin,Metalloproteinase Inhibitor, Matrix,Metalloproteinase Inhibitors, Matrix