Пространственное распределение протеогликанов суставного хряща бедренных мыщелков и тибиального плато при экспериментальном остеоартрозе у крыс

Abstract

Introduction. Very few works have studied the spatial distribution of proteoglycans of the articular cartilage of femoral condyles (FCs) and the tibial plateau (TP) in normal and experimental osteoarthritis (OA). The aim of the paper was to analyze the spatial distribution of lubricin and aggrecan in the articular cartilage of FCs and the TP in normal and experimental OA in rats. Materials and methods. We divided 15 male Wistar rats (weight 250–300 g) into three groups: intact, undergone sham surgery, and having experimental OA. Sham surgery was done with intra-articular injection of saline solution, and experimental OA was modeled by intra-articular injection of medical talc. We performed morphological and immunohistochemical studies using antibodies to Aggrecan and Lubricin to assess the spatial distribution of proteoglycans. Results. After 3 weeks in the group with OA, the thickness of the articular cartilage of FCs and the TP was 15% greater and 11% less, respectively, in comparison with that in the intact rats (p<0.05). In the intact group, the numerical density of chondrocytes of the superficial zone of the articular cartilage of the TP was 2.6 times higher compared to that of FCs; after 3 weeks, the group with OA showed the opposite trend. A similar pattern was in the middle and deep zones. Immunohistochemistry revealed the presence of intense staining on lubricin of isogenic groups of chondrocytes and extracellular matrix (ECM) of the middle zone of the articular cartilage of the TP in experimental OA. Conclusion. In experimental OA, we observed interstitial growth in the articular cartilage of FCs and signs of ECM destruction in superficial and middle zones of the articular cartilage of the TP. In experimental OA, the distribution of lubricin synthesis changes. For the middle zone chondrocytes, localized close to the surface zone, the color on lubricin is characteristic. Keywords: morphology, articular cartilage, aggrecan, lubricin, femoral condyles, tibial plateau, osteoarthritis, rat