Kim Hyun Ah, Lee Byung-Wan, Kang Dongchul, Kim Jae Hyeon, Ihm Sung Hee, Lee Minhyung
Department of Bioengineering, College of Engineering Hanyang University, Seoul, South Korea.
J Drug Target. 2009 Jan;17(1):1-9. doi: 10.1080/10611860802392982.
Islet transplantation is a promising strategy for treatment of diabetes. However, islets are exposed to hypoxia in the process of isolation and transplantation and prone to apoptosis. Vascular endothelial growth factor (VEGF) gene transfer is one of the promising strategies to address this problem. However, VEGF expression in the cells under normoxia is undesirable since it may induce pathological angiogenesis. Therefore, VEGF expression should be regulated to avoid this problem. In this study, hypoxia-inducible VEGF gene was transferred to islets using a non-viral carrier. Rat islets were transfected with high molecular weight PEI (25 kDa, PEI25K), low molecular weight PEI (2 kDa, PEI2K), and polyamidoamine dendrimer (PAMAM). PEI25K had higher transfection efficiency to rat islets than PAMAM or PEI2K. The hypoxia-inducible gene expression vector, pRTP801-Luc or pRTP801-VEGF was transferred to rat islets using PEI25K. Transfection assay with pRTP801-Luc showed that luciferase expression was induced in rat islets under hypoxia. In addition, transfer of pRTP801-VEGF showed that VEGF gene expression was higher under hypoxia than normoxia in rat islets. In conclusion, delivery of pRTP801-VEGF using PEI25K induces VEGF level specifically under hypoxia and may be useful for the development of anti-apoptotic strategies for islet transplantation.
胰岛移植是治疗糖尿病的一种有前景的策略。然而，胰岛在分离和移植过程中会暴露于缺氧环境，并且容易发生凋亡。血管内皮生长因子（VEGF）基因转移是解决这一问题的一种有前景的策略。然而，在常氧条件下细胞中的VEGF表达并不理想，因为它可能会诱导病理性血管生成。因此，应该调节VEGF的表达以避免这个问题。在本研究中，使用非病毒载体将缺氧诱导的VEGF基因转移到胰岛中。用高分子量聚乙烯亚胺（25 kDa，PEI25K）、低分子量聚乙烯亚胺（2 kDa，PEI2K）和聚酰胺胺树枝状大分子（PAMAM）转染大鼠胰岛。PEI25K对大鼠胰岛的转染效率高于PAMAM或PEI2K。使用PEI25K将缺氧诱导基因表达载体pRTP801-Luc或pRTP801-VEGF转移到大鼠胰岛中。用pRTP801-Luc进行的转染试验表明，在缺氧条件下大鼠胰岛中诱导了荧光素酶表达。此外，pRTP801-VEGF的转移表明，在缺氧条件下大鼠胰岛中VEGF基因表达高于常氧条件。总之，使用PEI25K递送pRTP801-VEGF可在缺氧条件下特异性诱导VEGF水平，可能有助于开发胰岛移植的抗凋亡策略。
