Identification of type IV collagenase in rat testicular cell culture: influence of peritubular-Sertoli cell interactions

• Published in: Biology of reproduction Vol. 43; no. 6; pp. 956 - 964
• Main Authors: Q X Sang, W G Stetler-Stevenson, L A Liotta, S W Byers
• Format: Journal Article
• Language: English
• Published: United States Society for the Study of Reproduction 01-12-1990
• Subjects: Amino Acid Sequence; Animals; Cell Communication; Cells, Cultured; Collagenases; Edetic Acid - pharmacology; Enzyme Activation - drug effects; Enzyme Precursors - chemistry; Enzyme Precursors - immunology; Enzyme Precursors - metabolism; Immunochemistry; Male; Matrix Metalloproteinase 9; Microbial Collagenase - chemistry; Microbial Collagenase - immunology; Microbial Collagenase - metabolism; Molecular Sequence Data; Molecular Weight; Phenylmercuric Acetate - analogs & derivatives; Phenylmercuric Acetate - pharmacology; Rats; Sertoli Cells - drug effects; Sertoli Cells - enzymology; Testis - cytology; Testis - drug effects; Testis - enzymology
• ISSN: 0006-3363; 1529-7268
• DOI: 10.1095/biolreprod43.6.956

In the testis, interactions between peritubular cells (mesenchyme) and Sertoli cells (epithelium), together with proteolytic
remodeling of the extracellular matrix, may play a central role in testicular development, morphogenesis, and spermatogenesis.
In this study we demonstrate that a metalloproteinase of 72 kDa present in rat Sertoli cell and Sertoli-peritubular cell coculture
medium is activated by p-aminophenylmercuric acetate (p-APMA) to a lower molecular mass form, indicating that it is likely
to be a latent collagenase. Immunoblots using antibodies to three different domains of type IV collagenase show that the 72-kDa
protease and a 76-kDa protease are type IV pro-collagenases. Sertoli cells cultured alone produce basal levels of type IV
collagenase that can be immunolocalized in the cytoplasm of cultured cells. Peritubular cells cultured alone produce much
less type IV collagenase. However, Sertoli and peritubular cells in coculture do produce type IV pro-collagenase, and in cultures
consisting predominantly of peritubular cells, the activated form of type IV collagenase was detected by both zymography and
immunoblotting. Cells growing during the transitional phase (from cell attachment to confluence) secrete more metalloproteinases
than during the confluent phase. In contrast, plasminogen activator levels are unaffected by time in culture. These results
show that rat testicular cells in culture produce and secrete type IV collagenase, and that the secretion and activation of
this enzyme and other metalloproteases is regulated by the ratio of mesenchymal cells to epithelial cells and time in culture.