Matrix metalloproteinase secretion is stimulated by TGF-beta in cultured lens epithelial cells.
OBJECTIVE
To determine if TGF-beta regulates the expression of metalloproteinases in chick lens annular pad cells.


METHODS
The activity of secreted matrix metalloproteinases was examined with gelatin zymography in primary cultures exposed to TGF-beta.


RESULTS
Metalloproteinases with electrophoretic mobilities corresponding to MMP2 and MMP9 were tentatively identified. Activated, processed forms of the two metalloproteinases were also observed. Plasminogen activators potentially capable of initiating metalloproteinase cascades were concomitantly elicited. Metalloproteinase secretion was shown to be specific for TGF-beta stimulation and independent of substrate composition.


CONCLUSIONS
These results indicate that TGF-beta-mediated processes could be responsible for localized lens capsular heterogeneity, establishing a substrate suitable for cell migration or the release of matrix-bound factors which influence the terminal differentiation of lens cells.
Richiert
D M
DM
Wayne State University School of Medicine Department of Anatomy and Cell Biology 540 E. Canfield, MI 48201, Detroit, USA. mireland@med.wayne.edu
Ireland
M E
ME
D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects; D002478:Cells, Cultured; D002645:Chickens; D017077:Culture Media, Conditioned / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004492:Edetic Acid / Q000037:antagonists & inhibitors / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects*; D005109:Extracellular Matrix / Q000378:metabolism; D005780:Gelatin / Q000378:metabolism; D007908:Lens, Crystalline / Q000166:cytology / Q000187:drug effects*; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D061965:Matrix Metalloproteinase Inhibitors; D020782:Matrix Metalloproteinases / Q000096:biosynthesis / Q000378:metabolism*; D010662:Phenylmercuric Acetate / Q000031:analogs & derivatives / Q000494:pharmacology; D010958:Plasminogen / Q000378:metabolism; D012680:Sensitivity and Specificity; D013997:Time Factors; D016212:Transforming Growth Factor beta / Q000494:pharmacology*
D017077:Culture Media, Conditioned; D061965:Matrix Metalloproteinase Inhibitors; D016212:Transforming Growth Factor beta; C010024:4-aminophenylmercuriacetate; D005780:Gelatin; D010958:Plasminogen; D004492:Edetic Acid; D020782:Matrix Metalloproteinases; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9; D010662:Phenylmercuric Acetate