COLLAGENASE FROM CORNEAL CELL-CULTURES AND ITS MODULATION BY PHAGOCYTOSIS

  • 1 January 1979
    • journal article
    • research article
    • Vol. 18  (6) , 588-601
Abstract
The uptake of latex by fibroblasts [rabbit] in confluent primary culture results in the secretion of collagenase at a linear rate for a prolonged period. Phagocytosis might constitute an important level of collagenase regulation in corneal ulceration. The collagenase in cell cultures is present in a latent form (40,000 MW) like that obtained from organ cultures of ulcerating corneas and can be activated proteolytically. Production of the latent collagenase in cell culture depends upon the presence of serum and diminishes greatly when serum is removed from the medium. Collagenase activity can be demonstrated after the latent collagenase was separated from serum antiproteases in the media. Alternatively, careful titration of the crude media with trypsin to saturate serum antiproteases, to release collagenase from the complex with .alpha.2-macroglobulin, and to activate latent collagenase also results in measurable collagenase activity. The collagenase that is secreted cleaves fibrillar type I collagen and cleaves soluble type I collagen into the typical 3/4 and 1/4 length fragments, as demonstrated by SDS[sodium dodecyl sulfate]-gel electrophoresis and EM.