Articular cartilage gene expression patterns in the tissue surrounding the impact site following applications of shear and axial loads

• Published in: BMC musculoskeletal disorders 2018-12, Vol.19 (1), p.449-449, Article 449
• Main Authors: McCulloch, R S, Mente, P L, O'Nan, A T, Ashwell, M S
• Format: Article
• Language: English
• Subjects: Animals; Apoptosis; Arthritis; Articular injury; Care and treatment; Cartilage (articular); Cartilage diseases; Cartilage, Articular - metabolism; Cartilage, Articular - pathology; Collagen (type II); Collagen Type II - genetics; Collagen Type II - metabolism; Enzymes; fas Receptor - genetics; fas Receptor - metabolism; Gene expression; Gene Expression Profiling - methods; Gene Expression Regulation, Enzymologic; Genomics; Hogs; Inflammation; Joint diseases; Knee; Musculoskeletal diseases; Osteoarthritis; Osteoarthritis, Knee - genetics; Osteoarthritis, Knee - metabolism; Osteoarthritis, Knee - pathology; Patella - metabolism; Patella - pathology; Physiology; Porcine; Sports injuries; Stress, Mechanical; Sus scrofa; Time Factors; Tissue Culture Techniques; Transcriptome; Trauma
• ISSN: 1471-2474; 1471-2474
• DOI: 10.1186/s12891-018-2374-2

Osteoarthritis is a degradative joint disease found in humans and commercial swine which can develop from a number of factors, including prior joint trauma. An impact injury model was developed to deliver in vitro loads to disease-free porcine patellae in a model of OA. Axial impactions (2000 N normal) and shear impactions (500 N normal with induced shear forces) were delivered to 48 randomly assigned patellae. The patellae were then cultured for 0, 3, 7, or 14 days following the impact. Specimens in the tissue surrounding the loading site were harvested and expression of 18 OA related genes was studied via quantitative PCR. The selected genes were previously identified from published work and fell into four categories: cartilage matrix, degradative enzymes, inflammatory response, and apoptosis. Type II collagen (Col2a1) showed significantly lower expression in shear vs. axial adjacent tissue at day 0 and 7 (fold changes of 0.40 & 0.19, respectively). In addition, higher expression of degradative enzymes and Fas, an apoptosis gene, was observed in the shear specimens. The results suggest that a more physiologically valid shear load may induce more damage to surrounding articular cartilage than a normal load alone.