Experimental Research Of PDGF-BB Anti-Apoptosis Of Cultured Lumbar Nucleus Pulposus Cells Induced By IL-L β In Vitro

Objective: To Study the effective molecular biology mechanism of PDGF-BB in retarding or preventing lumbar disc degeneration in cultured cells isolated from nucleus pulpsus exposed to IL-1β multaneously. Methods: Nucleus pulposus were microsurgically harvested from lumbar spine of 30 day SD rats . Chondrocytic cells were isolated, cultured in monolayer culture system and tested under the following conditions : 1) control group: growth in the presence of 15% felal bovine serum 2) IL-1βgroup, development of apoptosis model added with 100ng/ml IL-1β.3) IL-1β+PDGF-BB group,growth in the presence of 100ng/ml and 500ng/ml PDGF-BB were added simultaneously. 4)PDGF-BB group, growth in the presence of 500 ng/ml PDGF-BB. The effect of nucleus pulposus chondrocytive cells proliferation were measured by using MTT method. Apoptotic cells and the incidence of apoptosis were identified and determined by annexin-V-FITC and DNA analysis Flow Cytometry. The effect of IL-1βand PDGF-BB on the course of cell apoptosis were evaluated .Cultured cells ultrastructure were also observated with transmission electron microscopy. Results were analyzed with standard slatisctical techniques. Results: IL-1β group was used as a positive apoptosis model in vitro and treated with 100ng/ml IL-1β,resulting in a significantly greater percentage of apoptosis compared with the control group . IL-1β+PDGF-BB group was exposured to 500ng/ml PDGF-BB and 100ng/ml IL-1β simultaneously resulting in a significant decrease in the rate of apoptosis in cultured cells ,compared with those group whose cells were be treat with IL-1β.Conclusions:The results of this study demonstrate that it is feasible to develop a quantitative nucleus chondrocytic cells cuture system in vitro. Cultured SD Rate-derived cells have capacity of responding to biochemical stilmuli such as IL-1β in a manner that could engender degeneration change. These discoveries show that PDGF-BB can stimulate nucleus pulpous cells proliferation, retard or prevent programmed cells death in vitro. IL-1β can inducematrix degraduation in interverbral disc. But cultured cells which have been exposed to IL-1βhave lost none of their potential to upregulate extracellular matrix sythesis in response to stimulation with PDGF-BB. Administration of PDGF-BB may have therapeutic potential in the treatment of disc degeneration in the future...