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Absolute concentrations of mRNA for type I and type VI collagen in the canine meniscus in normal and ACL‐deficient knee joints obtained by RNase protection assay
Author(s) -
Wildey G. M.,
Billetz A. C.,
Matyas J. R.,
Adams M. E.,
McDevitt C. A.
Publication year - 2001
Publication title -
journal of orthopaedic research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.041
H-Index - 155
eISSN - 1554-527X
pISSN - 0736-0266
DOI - 10.1016/s0736-0266(00)00053-x
Subject(s) - anterior cruciate ligament , messenger rna , meniscus , osteoarthritis , knee joint , rna , chemistry , gene expression , rnase p , microbiology and biotechnology , dna , acl injury , gene , anatomy , pathology , biology , medicine , surgery , biochemistry , physics , alternative medicine , incidence (geometry) , optics
Relatively little is known about the cellular and molecular responses of the knee joint meniscus to joint injury, despite the functional importance of the tissue. We investigated how meniscus cells respond to joint injury in the early stages of post‐traumatic osteoarthritis by characterizing the changes in matrix gene expression in menisci at 3 and 12 weeks post‐surgery in dogs in which the anterior cruciate ligament (ACL) in one joint was transected and the other unoperated joint served as a control. Changes in the total RNA and DNA concentrations of the menisci were determined. Absolute concentrations of the mRNA of the COL1A1 gene of type 1 collagen, the major fibrillar collagen of the meniscus, and the COL6A3 gene of type VI collagen, a major repair molecule, were determined by quantitative ribonuclease (RNase) protection assay. The concentration of total RNA in medial and lateral menisci increased from 40 to 60 μg RNA/g wet wt in unoperated, control joints to 200—350 μg RNA/g wet wt in ACL‐deficient joints. No significant changes were detected in the concentration of DNA (900—1200 μg DNA/g wet wt). Low concentrations of COL1A1 (2—3 pmol mRNA/g DNA) and COL6A3 (0.3–0.6 pmol mRNA/g DNA) mRNA transcripts were measured in normal menisci. ACL‐deficiency induced a 20–38 fold increase in COL1A1 and COL6A3 mRNA concentration at 3 weeks, and an 11–19 fold increase at 12 weeks post‐surgery. In general, the increase in COL1A1 and COL6A3 mRNA concentrations was greater in medial menisci than in lateral menisci. These results demonstrate that the menisci initiate a vigorous biosynthetic response to transection of the ACL. © 2001 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.