Specific metabolism of proteoglycans from different topographical zones of the knee in patients with osteoarthritis: the variability of chondrocytes phenotype
The content and properties of cartilage proteoglycans from different topographical zones of knee joint of patients with idiopathic knee osteoarthritis (OA) of Grade III were investigated. The expression of cartilage main structural genes – proteoglycans (PG) – aggrecan, lumikan, versican, collagens type I and II, as well as proliferation and differentiation genes of chondrocytes – SOX-9, TGFβ-3, TGFβR, and KLF4 were examined in the cartilage specimens from these zones. The content and properties of proteoglycans differ between topographical zones: the zone with maximum mechanical load has minimal PG level. They are more firmly bounded to the collagen fibrils, more flexible in electric field and less aggregated. It has been revealed that the cells from all topographic zones despite the degeneration degree and mechanical load retain the capability to express genes of main components of extracellular matrix as well as signal proteins of proliferation and differentiation at the same level. However, the gene expression of proteoglycan versican and regulatory protein KLF4 was reduced in the most loaded zone.Thus, the phenotypical variant chondrocytes produce proteoglycans differing in quantity and property in varied zones of the knee cartilage.
About Authors (Correspondence):
Rusova T.V. – candidate of biological sciences, senior researcher of the laboratory-experimental department, e-mail: TRusova@niito.ru
Strokova E.L. – researcher of the laboratory-experimental department, e-mail: EZavyalova@niito.ru
Voropaeva A.A. – candidate of biological sciences, researcher of the innovations and intellectual property department, e-mail: Voropaeva2011@rambler.ru
Shchelkunova E.I. – researcher of the laboratory-experimental department, e-mail: EShelkunova@niito.ru