Experimental diabetes modulates collagen remodelling of joints in rats
Sandra A. Atayde1, Natalino H. Yoshinari1, Dafne P. Nascimento1, Sérgio Catanozi2, Priscila C. Andrade1, Ana Paula P. Velosa1, Edwin R Parra3, Marisa Passarelli2, Edna R Nakandakare2, Vera L Capelozzi3 and Walcy R. Teodoro1
1Rheumatology (LIM/17), 2Endocrinology (LIM/10) Division and 3Department of Pathology from Medical School of the University of Sao Paulo.
Offprint requests to: Walcy Rosolia Teodoro, Av. Dr. Arnaldo, 455 - sala: 3124, Cerqueira César. e-mail: walcyteodoro@terra.com.br, matrix@lim17.fm.usp.br, vcapelozzi@lim05.fm.usp.br
Summary. The aim of this study was to evaluate extracellular matrix components in articular cartilage, ligaments and synovia in an experimental model of diabetes. Young Wistar rats were divided into a streptozotocin-induced (STZ; 35 mg/kg) diabetic group (DG; n=15) and a control group (CG; n=15). Weight, blood glucose and plasma anti-carboxymethyllysine were measured 70 days after STZ infusions. Knee joints, patellar ligaments, and lateral and medial collateral ligaments were isolated and stained with hematoxylin-eosin and Picrosirius. The total collagen content was determined by morphometry. Immunofluorescence was employed to evaluate types I, III, and V collagen in ligaments and synovial tissues and types II and XI collagen in cartilage. Results: Higher blood glucose levels and plasma anti-carboxymethyllysine were observed in DG rats when compared to those in CG rats. The final weight was significantly lower in the DG rats than in the CG rats. Histomorphometric evaluation depicted a small quantity of collagen fibers in ligaments and articular cartilage in DG rats, as well as increased collagen in synovial tissue. There was a decrease in cartilage proteoglycans in DG rats when compared with CG rats. Immunofluorescence staining revealed an increase of collagen III and V in ligaments, collagen XI in cartilage, and collagen I in synovial tissue of DG rats compared with CG rats. Conclusion: The ligaments, cartilage and synovia are highly affected following STZ-induced diabetes in rats, due the remodeling of collagen types in these tissues. This process may promote the degradation of the extracellular matrix, thus compromising joint function. Our data may help to better understand the pathogenesis of joint involvement related to diabetes. Histol Histopathol 27, 1471-1479 (2012)
Key words: Diabetes, Streptozotocin, Collagen remodeling, Joint
DOI: 10.14670/HH-27.1471