右美托咪定对脂多糖诱导脐静脉内皮细胞凋亡的影响

Effect of dexmedetomidine on lipopolysaccharide 4nduced apoptosis in human umbilical vein endothelial cells

目的评价右美托咪定对脂多糖（lipopolysaccharide，LPS）诱导的血管内皮细胞凋亡的影响。方法参照随机数字表法将人脐静脉内皮细胞HUVEC．12随机分为4组（每组20孔）：正常对照组（C组）、右美托咪定组（D组）、LPS组（L组）、LPS＋右美托咪定组（L＋D组），培养24h后：四甲基偶氮唑盐微量酶反应比色法（MTF法）和流式细胞术分别检测细胞活力和细胞凋亡率，黄嘌呤氧化酶法和硫代巴比妥酸法（thiobarbituric acid，TBA）测定各组细胞超氧化物歧化酶（superoxide dismutase，SOD）的活性和丙二醛（malonaldehyde，MDA）的含量，Westernblot法检测细胞多聚腺苷酸二磷酸-1（Poly-ADPRibosypolymerase-1，PARPA）蛋白裂解片段的表达。结果L组和L＋D组细胞活力分别是0．95±0．08和1．08±0．10（P〈O．05），与C组比较，分别降低36％和27％；L组和L＋D组细胞凋亡率分别是（14．7＋1．8）％和（8．8±1．1）％（P〈O．05），分别是C组的2．6倍和1．1倍；L组和L＋D组细胞SOD活性分别是（99±6）U／nag和（182±9）U／mg（P〈0．05），与C组比较，分别降低53％和14％；L组和L＋D组细胞MDA含量分别是（29．9±1．8）nmol／mg和（19．3±2．1）nmol／mg（P〈0．05），分别是C组的1．6倍和79％；L组和L＋D组细胞内PARP-1片段（相对分子质量89x10。）表达分别是1．152±0．095和0．564±0．045（P〈0．05），分别是C组的4．8倍和1．8倍；D组上述指标的差异无统计学意义（P〉0．05）。结论右美托咪定可有效减少LPS诱导下脐静脉内皮细胞的凋亡，其机制可能与抑制氧化应激、下调PARP-1裂解片段的表达有关。

Objective To study the effect of dexmedetomidine on lipopolysaccharide （LPS） -induced apoptosis in human umbilical vein endothelial ceils. Methods Human umbilical vein endothelial cells were randomly divided into four group （n=20）： normal control group （group C ）, dexmedetomidine group （group D ）, LPS group （group L）, LPS plus dexmedetomidine group（group L＋D）. The cell viability and apoptosis was measured by MTT assay and flow cytometry respectively after 24 h of cell culture. The superoxide dismutase （SOD） activity and malonaldehyde（ MDA ） content was measured by xanthine oxidase method and thiobarbituric acid （TBA） test respectively. The expression of cleaved Poly-ADP Ribosy polymerase-1 （PARP-1） protein was detected by Western blot. Results The cell survival rate in group L and group L＋D were 0.95±0.08 and 1.08±0.10（P〈0.05）,which were decreased by 36% and 27% respectively when compared with group C. The apoptotie rate in group L and group L＋D were（ 14.70±1.8 ）% and （8.80±1.1）% （P〈0.05）, which were increased by 2.6 times and 1.1 times respectively when compared with group C. SOD activity in group L and group L＋D were （99±6） U/rng and （182±9） U/mg （P〈0.05）,which were decreased by 53% and 14% respectively when compared with group C. MDA content in group L and group L＋D were （29.9±1.8） nmol/mg and （19.3±2.1） nmol/mg（P〈0.05 ）, which were increased by 1.6 times and 79% respectively when compared with group C. The expression of PARP-1 protein fragment in group L and group L＋D were 1.152±0.095 and 0.564±0.045 （P〈0.05）, which were increased by 4.8 times and 1.8 times respectively when compared with group C. No significant difference was found in group D when compared with group C （P〉0.05）. Conclusions Dexmedetomidine can effectively reduce LPS-induced apoptosis in human umbilical vein endothelial cells by inhibiting oxidative stress and down-regulating expression of PARP-1 protein fragment.