Collagenase in a guinea PK3 model of natural osteoarthrftis
The Hartley strain albino guinea pig spontaneously develops osteoarthritis (OA) of the knees and hips, reaching advanced stages by age 10-12 months1. Histological and biochemical characterization of the Hartley strain guinea pig model of OA has shown it to be a useful animal model for studying the pathogenesis of OA in man. The hallmark of early OA is cartilage matrix degradation. Metalloproteinases (MMPs) are thought to play a major role in this cartilage destruction. The objective of our work is to characterize the regulation of gene expression for metalloproteinases implicated in the pathogenesis of OA in this animal model. We have developed a successful method for extracting quantities of RNA suitable for RT/PCR experiments from the knee joints of Hartley guinea pigs. Initial experiments were undertaken to obtain a cDNA clone of MMP-1 (iniersitial collagenase), an MMP upregulated in other model systems of OA. MMP-1 specific primers, designed by analysis of human, bovine, porcine and rabbit MMP-1 sequence, yielded a 173 bp product which was then cloned into the pNoTAH7 shuttle vector. Its identity was confirmed to be MMP-1 based upon % sequence homologies with MMP-1 from other species: 97% to bovine MMP-1, 90% to human and porcine MMP-1, and 88% to rabbit MMP-1; only 67% to human MMP-8 and 62% to human MMP-3, confirming the clone identity as MMP-1. Interestingly, the done is only 59% homologous to mouse MMP-1 and to rat MMP-1. MMP-1 from mouse and rat are homologous to collagenase 3, an MMP from breast carcinoma, and are likely members of a new MMP family, MMP-13<2>, to which they share >90% nucleotide sequence homology. The primers used to isolate guinea pig MMP-1 have failed to detect products from rat chondrosarcoma cells (Carl Flannery unpublished observation). To date, mis guinea pig MMP-1 clone appears to be the only bona fide MMP-1 isolated from rodents. Experiments are ongoing comparing the differential expression of MMP-1 from 2 month old (no pathology) versus 12 month old guinea pigs (OA pathology) by RNase protection assays. 18S rRNA control and MMP-1 signals are detectable in preliminary experiments using 1-6 |ig total RNA from 12 mo. old guinea pig knee cartilage. 1} A. M. Bendele, J. F. Hulman, Arth. & Rheum. 31,561-565(1988). 2) C. R. Planner/, J.D.Sandy, Trans, of the Ortho. fles.Soc. 20,102(1995).
Kraus, VB; Freund, EMN; Huebner, JL; Caterson, B
Volume / Issue
International Standard Serial Number (ISSN)