Regulation of Niacinamide on intervertebral disc cell apoptosis and energy metabolism related gene in vitro / 中国组织工程研究

ABSTRACT

BACKGROUND: Studies have reported that Niacinamide is capable of promoting the proliferation of intervertebral cell and protecting intervertebral disc (IVD) against interleukin-1 β-induced degeneration. However,the mechanism of Niacinamide underlying protecting IVD degeneration remains uncertain. OBJECTIVE: To investigate the regulatory effect of Niacinamide on interleukin-1 β-induced cell apoptosis and energy metabolism related gene in IVD in vitro. DESIGN, TIME AND SETTING: Experiments were performed in the Central Laboratory of Union Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology from November 2007 to May 2008. MATERIALS Fifty-six IVDs from L16 lumbar spine often Japanese white rabbits,aged 3-4 months and weighing 1.5-2.0 kg,were harvested and cultured in alginate gel for further experiments. METHODS: IVD cultured models were randomly divided into 4 groups normal control group (with the absence of drags), Niacinamide group (administrating 0.5 g/L Niacinamide), degeneration group (administrating 10 μg/L interlenkin-1β),treatment group (administrating 10 μg/L interleukin-1β and 0.5 g/L Niacinamide).After 2 weeks of culture,TUNEL staining and immunohistochcmical staining for FAS,Bcl-2, Caspase-3, hypoxia induced factor 1a, glucose transporter-1 and vascular endothelial cell growth factor were used to detect alternated cell apoptosis and expression of energy metabolism related genes. MAIN OUTCOME MEASURES: The positive cell rates of TUNEL staining and immunohistochemical staining in each group. RESULTS: The rate of TUNEL positive-staining cells of degeneration group was higher than normal control group (P=0.001). The rate of FAS positive-staining cells of degeneration group was obviously higher than normal control group (P＜0.01). The rate of Bcl-2 positive-staining cells of Niacinamide group was higher than normal control group (P=0.004). The rate of Caspase-3 positive-staining cells of treatment group was lower than degeneration group significantly (P=0,024).The rate of hypoxia induced factor- 1α positive-staining cells of Niacinamide group was lower than normal control group (P＜0.01),and the rate of degeneration group was higher than normal control group (P＜0.01 ). The rate of glucose transporter-1 positive-staining cells of treatment group was higher than normal control group(P＜0.01). CONCLUSION: Niacinamide can inhibit interleukin-1β-induced IVD cell apoptosis and alleviates interleukin-1β induced disturbance of energy metabolism.