Hong Hua, Zeng Jin-Sheng, Kreulen David L, Kaufman David I, Chen Alex F
Depts. of Pharmacology and Neurology, B403 Life Sciences Bldg., Michigan State Univ., East Lansing, MI 48824-1317, USA.
Am J Physiol Heart Circ Physiol. 2006 Nov;291(5):H2210-5. doi: 10.1152/ajpheart.01270.2005. Epub 2006 Jun 9.
Statins have recently been shown to exert neuronal protection in ischemic stroke. Reactive oxygen species, specifically superoxide formed during the early phase of reperfusion, augment neuronal injury. NADPH oxidase is a key enzyme for superoxide production. The present study tested the hypothesis that atorvastatin protects against cerebral infarction via inhibition of NADPH oxidase-derived superoxide in transient focal ischemia. Transient focal ischemia was created in halothane-anesthetized adult male Sprague-Dawley rats (250-300 g) by middle cerebral artery occlusion (MCAO). Atorvastatin (Lipitor, 10 mg/kg sc) was administered three times before MCAO. Infarct volume was measured by triphenyltetrazolium chloride staining. NADPH oxidase enzymatic activity and superoxide levels were quantified in the ischemic core and penumbral regions by lucigenin (5 microM)-enhanced chemiluminescence. Expression of NADPH oxidase membrane subunit gp91(phox) and membrane-translocated subunit p47(phox) and small GTPase Rac-1 was analyzed by Western blot. NADPH oxidase activity and superoxide levels increased after reperfusion and peaked within 2 h of reperfusion in the penumbra, but not in the ischemic core, in MCAO rats. Atorvastatin pretreatment prevented these increases, blunted expression of membrane subunit gp91(phox), and prevented translocation of cytoplasmic subunit p47(phox) to the membrane in the penumbra 2 h after reperfusion. Consequently, cerebral infarct volume was significantly reduced in atorvastatin-treated compared with nontreated MCAO rats 24 h after reperfusion. These results indicate that atorvastatin protects against cerebral infarction via inhibition of NADPH oxidase-derived superoxide in transient focal ischemia.
他汀类药物最近被证明在缺血性中风中具有神经保护作用。活性氧，特别是在再灌注早期形成的超氧化物，会加剧神经元损伤。NADPH氧化酶是产生超氧化物的关键酶。本研究检验了阿托伐他汀通过抑制短暂性局灶性缺血中NADPH氧化酶衍生的超氧化物来预防脑梗死的假说。通过大脑中动脉闭塞（MCAO）在氟烷麻醉的成年雄性Sprague-Dawley大鼠（250-300克）中制造短暂性局灶性缺血。在MCAO前三次给予阿托伐他汀（立普妥，10毫克/千克皮下注射）。通过氯化三苯基四氮唑染色测量梗死体积。通过光泽精（5微摩尔）增强的化学发光法定量缺血核心区和半暗带区域的NADPH氧化酶活性和超氧化物水平。通过蛋白质印迹分析NADPH氧化酶膜亚基gp91(phox)、膜转位亚基p47(phox)和小GTP酶Rac-1的表达。在MCAO大鼠中，再灌注后NADPH氧化酶活性和超氧化物水平升高，并在再灌注后2小时内在半暗带达到峰值，但在缺血核心区未达到峰值。阿托伐他汀预处理可防止这些升高，使膜亚基gp91(phox)的表达减弱，并防止再灌注后2小时半暗带中细胞质亚基p47(phox)向膜的转位。因此，与未治疗的MCAO大鼠相比，再灌注后24小时阿托伐他汀治疗组的脑梗死体积显著减小。这些结果表明，阿托伐他汀通过抑制短暂性局灶性缺血中NADPH氧化酶衍生的超氧化物来预防脑梗死。
