Osteogenic protein-1 is most effective in stimulating nucleus pulposus and annulus fibrosus cells to repair their matrix after chondroitinase ABC-induced in vitro chemonucleolysis.

Background Context: Chondroitinase ABC (C-ABC) is used in chemonucleolysis to degrade, with great specificity, the chondroitin sulfate and dermatan sulfate chains of proteoglycans (PGs). A recent study showed that osteogenic protein-1 (OP-1) is very effective in stimulating the production and formation of the extracellular matrix by rabbit intervertebral disc cells.

Purpose: To test the hypothesis that the repair of the extracellular matrix of the intervertebral disc after chemonucleolysis by C-ABC can be stimulated by exposure to a low dose of a growth factor, OP-1.

Recombinant osteogenic protein-1 upregulates extracellular matrix metabolism by rabbit annulus fibrosus and nucleus pulposus cells cultured in alginate beads.

This study was performed to determine if recombinant human osteogenic protein-1 (rhOP-1) is effective in promoting matrix synthesis and matrix formation by rabbit nucleus pulposus (NP) and annulus fibrosus (AF) cells cultured in alginate beads. The effects of culturing the cells in the presence of various concentrations of rhOP-1 were assessed by measuring changes in cell proliferation, proteoglycan (PG) and collagen synthesis and mRNA expression, and in the matrix contents of PG and collagen, as indicators of matrix accumulation. At high concentrations, rhOP-1 had a moderate mitogenic effect on both NP and AF cells.

Cyclic tensile stretch on bovine articular chondrocytes inhibits protein kinase C activity.

Osteoarthrosis, a common pathway of joint deterioration, is caused by mechanical stress loaded on articular cartilage. We previously demonstrated the involvement of protein kinase C (PKC) in the development of osteoarthritis in vitro. In this study, we examined the effect of mechanical stress on chondrocyte metabolism and the activity of PKC in vitro.

Hyaluronic acid inhibits interleukin-1-induced superoxide anion in bovine chondrocytes.

Objective: To examine the effect of hyaluronic acid (HA) on the induction of superoxide anion by IL-1 in chondrocytes.

Materials And Methods: Bovine articular chondrocytes were treated with different concentrations of IL-1. A chemiluminescent probe (L-012) was added to the medium and chemiluminescence detection was used to measure super oxide anion.

Hyaluronic acid increases proteoglycan synthesis in bovine articular cartilage in the presence of interleukin-1.

Osteoarthritis is a common joint disorder in humans. Although intra-articular injection of hyaluronic acid (HA) is in widespread clinical use, there are limited data on the effect of HA on degenerated cartilage. When bovine articular cartilage is degraded with interleukin-1, HA penetrates the cartilage and accumulates in the pericellular matrix of chondrocytes.