抗TNF-α中和抗体通过升高脂联素水平减轻小鼠心肌缺血/再灌注损伤的作用

Protective effect of neutralizing TNF-α against myocardial ischemia/reperfusion injury in mice is partially exerted via adiponectin upregulation

目的:阐明心肌缺血/再灌注(MI/R)时,脂联素(APN)与肿瘤坏死因子-α(TNF-α)的关系,以及使用中和抗体阻断TNF-α可否提高血浆APN,进而发挥心肌保护作用。方法:96只成年雄性C57小鼠和36只ob/ob小鼠均采用30 min缺血/再灌注(I/R)建立MI/R模型。96只C57小鼠分为假手术组、手术+盐水对照组及手术+抗TNF-α中和抗体治疗组(n=32);36只ob/ob小鼠分为ob/ob假手术组、ob/ob手术+盐水对照组及ob/ob手术+抗TNF-α中和抗体治疗组(n=12)。假手术或缺血20 min后,腹腔注射给予单次抗TNF-α中和抗体或盐水干预。分别采用ELISA检测TNF-α与APN血浆水平;小鼠心脏超声评估心脏LVEF;伊文氏蓝/TTC染色检测心脏梗死面积;以及TUNEL/Caspase-3活性检测观察心肌细胞凋亡。结果:血浆ELISA测定发现,MI/R后,小鼠血浆TNF-α水平在再灌后1 h即显著升高,后缓慢下降。注射抗TNF-α中和抗体可在再灌后1 h即中和TNF-α(P<0.01),同时在再灌注3 h、8 h、1 d及3 d后4个时间点,较给予盐水对照显著升高血浆APN(P<0.01)。通过小鼠心脏超声、伊文氏蓝/TTC染色和TUNEL/Caspase-3活性检测发现,与给予盐水的对照相比,腹腔注射抗TNF-α中和抗体可提高小鼠的心肌功能(P<0.05)、减少梗死面积(P<0.01)及心肌细胞的凋亡(P<0.01)。而在ob/ob小鼠中,通过以同样的实验方法证实,单次注射抗TNF-α中和抗体已不能提高血浆APN的含量,其减轻心肌损伤的作用同样被显著削弱,但给予APN球状片段仍可发挥心肌保护作用。结论:以抗TNF-α的中和抗体阻断TNF-α可逆转MI/R后血浆APN的降低并发挥心肌保护作用,提示抗TNF-α中和抗体发挥的心肌保护作用可能部分通过提高APN实现。

Adult male mice and ob/ob mice were subjected to 30 min of MI followed by R. Animals were injected with TNF-α antagonist or vehicle 10 min before R. Mice were divided into six groups： sham group, MI/R ＋ vehicle group, MI/R ＋ TNF-eL blockade group, ob/ob sham group, ob/ob ＋ MI/R ＋ vehicle group, and ob/ob ＋ MI/R ＋ TNF-et blockade group. RESULTS ： Compared with that of vehicle, elevation of plasma APN concentration at 3 h, 8 h, 1 day, and 3 days after MI/R was observed in TNF-α antagonist treatment group. Administration of TNF-α antagonist ameliorated MI/R injury in WT mice, evidenced by consistently augmented cardiac function, reduced infarct size and apoptosis. TNF-α antagonist failed to augment APN levels or exert significant cardioprotective effects in ob/ob mice, but administration of glob-