Autocrine Induction of Collagenase by Serum Amyloid A-Like and β ₂ -Microglobulin-Like Proteins

Abstract

Two autocrine proteins of 14 and 12 kilodaltons that induce the synthesis of rabbit fibroblast collagenase were identified. The proteins were purified from serum-free culture medium taken from rabbit synovial fibroblasts stimulated with phorbol myristate acetate. The amino-terminal sequences of the 14- and 12-kilodalton species were approximately 60 to 80 percent homologous with serum amyloid A and beta 2 microglobulin, respectively. The polyacrylamide gel-eluted proteins retained the ability to induce collagenase synthesis in rabbit and human fibroblasts. These autocrine proteins may provide a means to modulate collagenase synthesis in normal remodeling as well as in inflammation and disease states.

Synergistic, additive, and antagonistic effects of interleukin‐1β, tumor necrosis factor α, and γ‐interferon on prostaglandin e, hyaluronic acid, and collagenase production by cultured synovial fibroblasts

“…Regulation of cyclooxygenase levels may also have a role, since synthesis of this enzyme is induced by IL-1 (41). Induction of collagenase by IL-1 and TNFa most likely involves increased transcription of the procollagenase gene (10) and may be mediated by an autocnne-dependent mechanism (42).…”

Activation of Transcription Factor SAF Involves Its Phosphorylation by Protein Kinase C

“…The consequence of this action is the induction of expression of genes responsive to these transcription factors. SAA is one such gene shown to be activated by PMA (3)(4)(5)33). To determine whether PMA treatment cause induction of SAA in rabbit synoviocyte HIG82 cells (ATCC) under the present culturing condition, HIG82 cells were cultured with PMA (100 nM) for 24 h, and the level of SAA mRNA was measured by Northern blot analysis (Fig.…”

Serum Amyloid A Protein Binds to Outer Membrane Protein A of Gram-negative Bacteria

“…For instance, SAA has been reported to cause chemotaxis and activation of several cell types (5-7), but HDL can inhibit these responses (5, 6) leaving it uncertain whether this occurs in vivo. SAA has also been reported to induce a number of other cellular responses, including collagenase production (8) and induction of secretory phospholipase A2 (9). Previously described binding properties include interaction with a number of cell types such as platelets and T cells (10,11) as well as binding to extracellular matrix glycoproteins such as laminin (11,12) and the proteoglycans heparin and heparan sulfate (13).…”