Qi Jingzong, Li Yizhao, Zhang Hongwei, Cheng Yanna, Sung Yongfu, Cao Jichao, Zhao Ying, Wang Fengshan
Institute of Biochemical and Biotechnological Drug, School of Pharmaceutical Sciences, Shandong University, Jinan 250012, Shandong, China.
Brain Res. 2009 Mar 13;1260:76-83. doi: 10.1016/j.brainres.2008.12.079. Epub 2009 Jan 18.
Low-molecular-weight heparin (LMWH) and Cu,Zn-superoxide dismutase (SOD) were extensively investigated on preventing brain reperfusion injury after ischemia (BRII) in the past few years and both exhibited some advantages as well as limits in practice. To explore whether chemical modification for LMWH and SOD can lead to improved bioactivity,in our present study, we examined the efficacy of LMWH conjugated SOD (LMWH−SOD) in the model of BRII gerbils. Ischemia/reperfusion was performed for 5 min by clamping the bilateral common carotid arteries of gerbils. LMWH−SOD, SOD and the mixture of LMWH and SOD (LMWH+SOD) were administered intravenously to corresponding animals just before ischemia. 24 h after reperfusion, serum malondialdehyde (MDA) content and SOD activity were measured, the expression of intercellular adhesion molecule-1 (ICAM-1) was examined by immunohistochemistry, and the brain sections were processed for Nissl staining and terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end-labeling.The results showed that LMWH−SOD significantly lowered MDA content (P<0.001, versus SOD and LMWH+SOD) and elevated SOD activity (P<0.05, versus SOD and LMWH+SOD) in the serum of BRII gerbils. Immunohistochemical results indicated ICAM-1 positive staining was lighter, pyramidal cells of hippocampal CA1 region were more regular and the changes in cell edema were minor, and apoptosis of hippocampal cells was milder in LMWH−SOD treated animals than in SOD or LMWH+SOD treated animals, untreated BRII animals and sham-operated animals. The results suggest that the novel LMWH−SOD conjugate can inhibit upregulation of ICAM-1 and prevent neuronal cell apoptosis in BRII gerbils, and the LMWH−SOD conjugate has better anti-inflammatory and neuroprotective effects in BRII than native SOD and the mixture of LMWH and SOD.
在过去几年中，低分子量肝素（LMWH）和铜锌超氧化物歧化酶（SOD）在预防缺血后脑再灌注损伤（BRII）方面得到了广泛研究，两者在实际应用中均表现出一些优点和局限性。为了探讨对LMWH和SOD进行化学修饰是否能提高其生物活性，在本研究中，我们检测了LMWH偶联SOD（LMWH-SOD）在沙土鼠BRII模型中的疗效。通过夹闭沙土鼠双侧颈总动脉进行5分钟的缺血/再灌注。在缺血前，将LMWH-SOD、SOD以及LMWH与SOD的混合物（LMWH+SOD）静脉注射给相应的动物。再灌注24小时后，检测血清丙二醛（MDA）含量和SOD活性，通过免疫组织化学检测细胞间黏附分子-1（ICAM-1）的表达，并对脑切片进行尼氏染色和末端脱氧核苷酸转移酶（TdT）介导的dUTP缺口末端标记。结果显示，LMWH-SOD显著降低了BRII沙土鼠血清中的MDA含量（与SOD和LMWH+SOD相比，P<0.001），并提高了SOD活性（与SOD和LMWH+SOD相比，P<0.05）。免疫组织化学结果表明，LMWH-SOD处理的动物中ICAM-1阳性染色更浅，海马CA1区锥体细胞更规则，细胞水肿变化更小，海马细胞凋亡比SOD或LMWH+SOD处理的动物、未处理的BRII动物和假手术动物更轻。结果表明，新型LMWH-SOD偶联物可抑制ICAM-1的上调，预防BRII沙土鼠神经元细胞凋亡，且LMWH-SOD偶联物在BRII中比天然SOD以及LMWH与SOD的混合物具有更好的抗炎和神经保护作用。
