烟酸对兔动脉粥样硬化斑块及MK2和骨桥蛋白表达的影响

摘要

ObjectiveToinvestigatetheeffectsofnicotinicacidontheatheroscleroticplaquesformationand theexpressionofosteopontin(OPN)andmitogen-activatedproteinkinase-activatedproteinkinase2(MK2)inrabbits. Methods Twenty-fourNewZealandwhiterabbitswererandomlydividedintothreegroups:controlgroup,hyperlipi-demiagroupandniacingroup.Controlgroupwasfedwithnormaldietandhyperlipidemiagroupwithhighfatdietfor 14weeks.Afterbeingfedwithfatdietfor8weeks,niacingroupwasfedthesamefatdietplusniacin[200mg/(kg·d)] for6weeks.Thebloodlipidlevelsweredetectedbeforeandafterexperiment.Allrabbitsweresacrificedtodetectthe histopathologicalchangesinaortasattheendofthe14thweek,real-timefluorescencequantitativepolymerasechain reactionwasusedtodetecttheexpressionsofMK2mRNAandOPNmRNAinaortasineachgroup,andimmunohisto-chemistrywasusedtodetecttheexpressionofOPNinaortas.Results Comparedwithcontrolgroup,rabbitsfedwith highfatdietshowedhigherserum levelsofTC,TGandLDL-Candmoreaortaplaquearea(P<0.05),theexpressions ofMK2andOPNincreasedsignificantly(P<0.01).Comparedwithhyperlipidemiagroup,rabbitstreatedwithniacin showedlessserumlevelsofTC,TGandLDL-Candlessaortaplaquearea(P<0.05),theexpressionsofMK2and OPNdecreasedsignificantly(P<0.01).Conclusion Niacin′sroleofanti-atherosclerosismayberelatedtoitseffect ofdown-regulatingtheexpressionofMK2andOPN.%　　目的探讨烟酸对兔动脉粥样硬化斑块形成（AS）和丝裂原活化蛋白激酶激活蛋白激酶2（MK2）及骨桥蛋白（OPN）的影响。方法24只新西兰兔按随机数字表法分为对照组、高脂组和烟酸组，每组8只，对照组和高脂组分别给予普通饮食和高脂饮食14周，烟酸组给予高脂饮食8周后加用烟酸200mg·kg-1·d-1共6周。实验前后抽血检测血脂水平，14周末进行主动脉病理学检查，采用实时荧光定量聚合酶链反应检测各组兔主动脉壁MK2mRNA、OPNmRNA表达，采用免疫组化法检测兔主动脉壁OPN表达。结果与对照组相比，高脂组TG、TC和LDL-C显著升高（P＜0．05），主动脉斑块面积明显增大（P＜0．05），MK2、OPN表达显著增加（P＜0．01）。与高脂组相比，烟酸组 TC、TG和LDL-C显著降低（P＜0．05），主动脉斑块面积显著缩小（P＜0．05），MK2、OPN表达显著减少（P＜0．01）。结论烟酸具有抗 AS作用，其机制可能与下调 OPN和MK2的表达有关。