Regulation of the friction coefficient of articular cartilage by TGF‐β1 and IL‐1β

• DOI: 10.1002/jor.20713
• Publication Date: 2008-08-06T22:18:16Z
• Authors: Grayson DuRaine; Corey P. Neu; Stephanie M.T. Chan; Kyriakos Komvopoulos; Ronald K. June; A. Hari Reddi
• Keywords: Boundary lubrication; Tribometer

Abstract Articular cartilage functions to provide a low‐friction surface for joint movement many decades of life. Superficial zone protein (SZP) is glycoprotein secreted by chondrocytes in the superficial layer articular that contributes effective boundary lubrication. In both cell and explant cultures, TGF‐β1 IL‐1β have been demonstrated to, respectively, upregulate downregulate SZP levels. It was hypothesized friction coefficient could also be modulated these cytokines through regulation. The between explants (both untreated treated with or IL‐1β) smooth glass due sliding lubrication regime measured pin‐on‐disk tribometer. quantified using an enzyme‐linked immunosorbant assay localized immunohistochemistry. Both treatments resulted decrease location‐ time‐dependent manner. Changes treatment corresponded increased depth staining within zone, while changes were independent staining. However, induced roughness, determined from analysis images obtained atomic force microscope. These findings demonstrate low can modified depends on multiple factors, including localization roughness. © 2008 Orthopaedic Research Society. Published Wiley Periodicals, Inc. J Orthop Res 27:249–256, 2009