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

Abstract

This study was performed to determine if recombinant human osteogenic protein-] (rhOP-I) 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-l had a moderate mitogenic effect on both NP and A F cells. It also stimulated the synthesis of PG and collagen in a dose-dependent manner: this was associated with a corresponding increase in the expression of mRNA for aggrecan core protein and collagen type 11. The stimulatory effect of rhOP-1 on PG synthesis was more pronounced than that on collagen synthesis. Continuous treatment with rhOP-1 led to an increase in the total DNA, P G and collagen contents in both N P and A F cultures. The results presented here provide evidence of the ability of rhOP-l to stimulate the metabolism of both rabbit A F and N P cells cultured in alginate beads.

PDGF, bFGF and IGF-I stimulate the proliferation of intervertebral disc cells in vitro via the activation of the ERK and Akt signaling pathways

“…This is in agreement with most in vitro studies, where the mitogenic responses of AF and NP cells are comparable [7,25].…”

Transfection of NF-κB decoy oligodeoxynucleotide suppresses pulmonary metastasis by murine osteosarcoma

“…The cells were recovered by centrifugation at 100 g for 5 min. 25 The cells were then resuspended in hypotonic buffer (Active Motif, Carlsbad, CA), and the cytoplasmic fraction was isolated by centrifugation (14 000 g, 4 1C). The nuclear fraction was separated by resuspending the residual pellet in complete lysis buffer (Active Motif) followed by centrifugation (14 000 g, 4 1C).…”

New Challenges for Intervertebral Disc Treatment Using Regenerative Medicine

“…If the purpose is to screen a large number of compounds, a highdensity monolayer culture of primary cells may be suitable because the format permits the use of robotic manipulation. Three-dimensional culture systems, such as alginate bead culture, 70,71 are useful to study disc cells in a phenotypically stable state. 64 Although other culture systems, such as collagen gel, or collagen-coated monolayer culture, may be suitable for AF cells, the use of two different culture systems in the same experiment may add complications for protocol development and data interpretation.…”