The Effect of Extracellular Collagen on Synthesis of Extracellular Matrix in a 3-Dimensional Culture of Intervertebral Disc Cells / 대한척추외과학회지

ABSTRACT

STUDY DESIGN: In-vitro experimental study. OBJECTIVES: To determine the proteoglycan synthesis of the rabbit nucleus pulposus cells in various concentration of extracellular collagen type I and II under the stimulation of TGF-beta1. SUMMARY OF LITERATURE REVIEW Therapeutic effect of growth factor and gene therapy can be altered by composition of extracellular matrix. However, the effect of extracellular collagen types I and II on synthetic activity of intervertebral disc cells is not thoroughly studied before. MATERIALS AND METHODS: The nucleus pulposus cells were isolated and cultured from 10 skeletally mature rabbits. Cultures were trypsinized and incorporated into alginate beads with different concentration of extracellular collagen type I and II (0.5%, 1.0% and 1.5%). Those cultures with TGF-beta1 (10 ng/ml) served stimulated condition of matrix synthesis. Newly synthesized proteoglycans were assessed by 35 S-sulfate incorporation using chromatography on Sephadex G-25 in PD-10 columns. Scintillation count was normalized with DNA content by Hoechst dye method. RESULTS: In basal condition, difference in proteoglycan synthesis in given concentration of extracellular collagen type I and II were statistically insignificant. In stimulated condition with TGF-beta1, difference in proteoglycan synthesis in given concentration of extracellular collagen type I and II was also statistically insignificant. However, cultures in stimulated condition with TGF-beta1 showed increased amount of newly synthesized proteoglycans compared to those of basal condition regardless of the concentration of extracellular collagen type I and II (p < 0.05). CONCLUSION: Anabolic response of rabbit nucleus pulposus cells is relatively insensitive to extracellular matrix composition, which facilitates application of gene therapy in various conditions of disc degeneration.