Kubo Masayuki, Li Tao-Sheng, Kamota Takahiro, Ohshima Mako, Qin Shu-Lan, Hamano Kimikazu
Department of Surgery and Clinical Science, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan.
J Cell Physiol. 2009 Aug;220(2):508-14. doi: 10.1002/jcp.21803.
Cell-based angiogenesis is a promising method for the treatment of ischemic diseases, but the poor retention of implanted cells in targeted tissues is a major drawback. We tested whether hypoxic preconditioning increased retention and angiogenic potency of implanted cells in ischemic tissue. Hypoxic preconditioning of mouse peripheral blood mononuclear cells (PBMNCs) was done with 24 h of culture under 2% O(2). Normoxia-cultured PBMNCs were used as a control. Hypoxic preconditioning increased the adhesion capacity of the PBMNCs. Moreover, the expression of integrin alphaM and CXCR4 was significantly higher in the hypoxia-preconditioned PBMNCs than in the normoxia-cultured PBMNCs. Interestingly, the expression of intercellular adhesion molecule-1 (ICAM-1), a ligand of integrin alphaM, and stromal cell-derived factor-1 (SDF-1), a chemokine for CXCR4, were remarkably increased in the ischemic hindlimbs. The retention of the hypoxia-preconditioned PBMNCs was significantly higher than that of the normoxia-cultured PBMNCs, 3 days after their intramuscular implantation into ischemic hindlimbs. We also noted better blood flow in the ischemic hindlimbs implanted with the hypoxia-preconditioned PBMNCs than in those implanted with the normoxia-cultured PBMNCs, 14 days after treatment. Furthermore, antibody neutralization of integrin alphaM and CXCR4 abolished completely the increased cell retention and angiogenic potency of the hypoxia-preconditioned PBMNCs after implantation into the ischemic hindlimbs. These results indicate that hypoxic preconditioning of implanted cells is a feasible method of enhancing therapeutic angiogenesis by increasing their retention.
基于细胞的血管生成是治疗缺血性疾病的一种有前景的方法，但植入细胞在靶组织中的低留存率是一个主要缺点。我们测试了低氧预处理是否能提高植入细胞在缺血组织中的留存率和血管生成能力。对小鼠外周血单个核细胞（PBMNCs）进行低氧预处理，方法是在2%氧气条件下培养24小时。常氧培养的PBMNCs用作对照。低氧预处理提高了PBMNCs的黏附能力。此外，低氧预处理的PBMNCs中整合素αM和CXCR4的表达明显高于常氧培养的PBMNCs。有趣的是，整合素αM的配体细胞间黏附分子-1（ICAM-1）和CXCR4的趋化因子基质细胞衍生因子-1（SDF-1）在缺血后肢中的表达显著增加。将低氧预处理的PBMNCs肌肉注射到缺血后肢3天后，其留存率明显高于常氧培养的PBMNCs。我们还注意到，治疗14天后，植入低氧预处理的PBMNCs的缺血后肢的血流比植入常氧培养的PBMNCs的缺血后肢更好。此外，整合素αM和CXCR4的抗体中和完全消除了低氧预处理的PBMNCs植入缺血后肢后细胞留存率和血管生成能力的增加。这些结果表明，对植入细胞进行低氧预处理是通过提高其留存率来增强治疗性血管生成的一种可行方法。
