左卡尼汀对高糖诱导雪旺细胞凋亡的影响

Effect of L-carnitine on apoptosis in Schwann cells induced by high glucose

目的 探讨左卡尼汀对高糖诱导雪旺细胞凋亡的影响.方法 将体外培养的细胞株RSC96以1.5×104个/ml的密度接种于96孔培养板（200 μ/孔）或以2× 105个/ml的密度接种于6孔培养板（2ml/孔）,培养24h.采用随机数字表法,将其分为4组（n=24）：正常对照组（C组）、高糖组（H组）、高糖＋左卡尼汀组（H＋L组）和甘露醇渗透压对照组（M组）.C组于含5.6 mmoUL葡萄糖的正常培养基中孵育;H组于含50 mmol/L葡萄糖的培养基中孵育;H＋L组于含50 mmoUL葡萄糖和终浓度为50 μmoUL左卡尼汀的培养基中孵育;M组于含5.6 mmol/L葡萄糖和44.4 mmol/L甘露醇的培养基中孵育.于孵育48 h时,倒置显微镜下观察细胞生长情况,采用黄嘌呤氧化酶法测定SOD的活性,硫代巴比妥酸法测定MDA的含量,MTT法测定细胞活力,流式细胞术检测细胞凋亡率,Western blot法检测活化的半胱氨酸天冬氨酸酶3（caspase-3）以及多聚腺苷酸二磷酸-1（PARP-1）蛋白表达.结果 与C组比较,H组和H＋L组细胞活力和SOD活性降低,细胞凋亡率和MDA含量升高,活化的caspase-3和PARP-1蛋白表达上调（P＜0.05）,M组上述各指标差异无统计学意义（P＞0.05）;与H组比较,H＋L组细胞活力和SOD活性升高,细胞凋亡率和MDA含量降低,活化的caspase-3和PARP-1蛋白表达下调（P＜0.05）.结论 左卡尼汀可减轻高糖诱导雪旺细胞的凋亡,其机制与抑制氧化应激反应,从而下调活化的caspase-3和PARP-1的表达有关.

Objective To investigate the effect of L-carnitine on the apoptosis in Schwann cells induced by high glucose.Methods The cell line RSC96 cultured in vitro were seeded in 96-well plates at a density of 1.5 × 104/ml （200 μl/well） or in 6-well plates at a density of 2 × 105/ml （2 ml/well） and cultured for 24 h.The cells were randomly divided into 4 groups （n =24 each） using a random number table：normal control group （group C）,high glucose group （group H）,high glucose ＋ L-carnitine group （group H ＋ L）,and mannitol osmotic control group （group M）.The cells in group C were incubated in the plain culture medium containing normal glucose （5.6 mmol/L）.The cells were incubated in the medium containing glucose 50 mmol/L in group H or in the medium containing glucose 50 mmol/L and L-carnitine 50 μmol/L （final concentration） in group H ＋ L.The cells were incubated in the medium containing normal glucose （5.6 mtmol/L） and mannitol 44.4 mmol/L in group M.At 48 h of incubation,cell growth conditions were observed under inverted microscope,superoxide dismutase （SOD） activity was measured by xanthine oxidase method,malondialdehyde （MDA） content was measured by thiobarbituric acid test,cell viability was measured by MTT assay and cell apoptosis was measured by flow cytometry.The expression of activated caspase-3 and poly （ADP-ribose） polymerase-1 （PARP-1） protein was detected by Western blot.Results Compared with group C,the cell viability and SOD activity were significantly decreased,MDA content and apoptotic rate were increased,and the expression of activated caspase-3 and PARP-1 protein was up-regulated in H and H ＋ L groups,and no significant changes were found in group M.Compared with group H,the cell viability and SOD activity were significantly increased,MDA content and apoptotic rate were decreased,and the expression of activated caspase-3 and PARP-1 protein was down-regulated in group H ＋ L.Conclusion L-camitine can attenuate high glucose-induced apoptosis in Schwann cells by inhibiting oxidative stress responses and down-regulating the expression of activated caspase-3 and PARP-1.