Metabolic Characteristics of in Vitro Cultured Human Chondrocytes in Relation to the Histopathologic Grade of Osteoarthritis

Proteoglycan fragments in joint fluid

“…This loss of matrix, possibly combined with a decreased chondrocyte activity, may cause the decrease in the concentration of cartilage matrix components in synovial fluid, which we observe in the present study. This suggested sequence of events is supported both by observations on human arthrotic joint cartilage and by animal studies (Mankin et al 1971, Vignon et al 1983, Carney et al 1984, Adams 1989, Bulstra et al 1989.…”

Chondrocyte gene expression in osteoarthritis: Correlation with disease severity

“…In comparison to previous studies using cultured cells, the method used herein measures gene expression at the time of cell isolation and avoids changes introduced by cell culture conditions. 7,17,18 The experimental approach of the present study is more likely to reflect cellular function in vivo.…”

“…To the contrary, numerous in vitro studies indicate that the rates of synthesis and secretion by the chondrocyte are increased, at least in some regions. [6][7][8][9][10][11] Quantitative assessment of protein synthesis, for example by Western immunoblotting, has been hampered by the fact that chondrocyte metabolism is very slow; thus long culture periods are necessary to detect small differences in protein accumulation. Behavior of explants or isolated cells in vitro may not reflect the status of tissue metabolism in vivo.…”

Toll‐like receptors and chondrocytes: The lipopolysaccharide‐induced decrease in cartilage matrix synthesis is dependent on the presence of toll‐like receptor 4 and antagonized by bone morphogenetic protein 7

“…Specimens were embedded in paraffin and sectioned at 4 m. After deparaffination, the sections were stained with Safranin O according to standard protocols. The histopathologic changes in the cartilage sections were then evaluated by 2 independent assessors using the modified Mankin score (scale 0-14) (21).…”