A role for the interleukin-1 receptor in the pathway linking static mechanical compression to decreased proteoglycan synthesis in surface articular cartilage

• Published in: Archives of biochemistry and biophysics 2003-05, Vol.413 (2), p.229-235
• Main Authors: Murata, Minako, Bonassar, Lawrence J., Wright, Marianne, Mankin, Henry J., Towle, Christine A.
• Format: Article
• Language: English
• Subjects: Animals; Cartilage; Cartilage - metabolism; Cartilage - physiology; Cartilage biomechanics; Cartilage, Articular - metabolism; Cattle; Dose-Response Relationship, Drug; Glycosaminoglycans - metabolism; Humans; Interleukin-1; Interleukin-1 - metabolism; Kinetics; Nitric Oxide Synthase - metabolism; Nitric Oxide Synthase Type II; Proteoglycan; Proteoglycans - metabolism; Receptors, Interleukin-1 - metabolism; Receptors, Interleukin-1 - physiology; Reverse Transcriptase Polymerase Chain Reaction; RNA - metabolism; RNA, Messenger - metabolism; Signal Transduction; Static compression; Stress, Mechanical; Time Factors
• ISSN: 0003-9861; 1096-0384
• DOI: 10.1016/S0003-9861(03)00129-2

Loading of articular cartilage during weight bearing is essential for the maintenance of cartilage function. Although certain cyclic loading protocols stimulate extracellular matrix synthesis, constant or static compression decreases proteoglycan and collagen synthesis in cartilage explants. The goal of this study was to determine whether the compression-induced decrease in proteoglycan synthesis involves an interleukin-1 (IL-1) signaling pathway. Cartilage explants were compressed 50% in the presence of IL-1 receptor antagonist (IL-1ra), and the incorporation of [ 35 S ]sulfate into macromolecules was measured. IL-1ra increased sulfate incorporation in compressed cartilage but not in cartilage maintained at the in situ thickness (0% compression). IL-1α and IL-1β mRNAs were detected in cartilage compressed 50% for at least 3 h, while nitric oxide synthase II mRNA was only detected in cartilage compressed 50% for 6 h. The data support a role for the IL-1 receptor in the pathway linking static compression to reduced proteoglycan synthesis.