GENE THERAPY FOR PULMONARY HYPOPLASIA IN CONGENITAL DIAPHRAGMATIC HERNIA

背景/目的：尽管近年来治疗先天性膈疝（CDH）伴肺发育不全的方法取得进展，但其预后仍较差，胎儿和新生儿时期的肺发育被认为更为重要。初步研究表明，肾上腺髓质素（AM）增加了硝基酚处理大鼠CDH模型的分支形态发生。在本研究中，我们检测了AM基因转移对家兔CDH模型肺生长的影响。方法：在妊娠第24天（孕期31天）手术制造新西兰大白兔胎左侧先天性膈疝。对照动物在妊娠第24天开腹。利用带正电的可生物降解明胶制备离子连接DNA-明胶复合物，延缓DNA降解。实验动物左膈切开后气管注射AM- DNA明胶复合物（AM-明胶组）、明胶（明胶组）和生理盐水（生理盐水组）。结果：妊娠第30天，AM明胶组大鼠肺体重比显著高于明胶组和生理盐水组，但显著低于对照组。与明胶组、生理盐水组和对照组相比，AM明胶组肺内AM显著升高。AM明胶组免疫组化显示AM在气道细胞和血管细胞中有较强的染色。AM明胶组AM m-RNA升高。结论：AM基因转染对兔先天性膈疝模型有一定的治疗作用。

Background/Purpose : While the prognosis in congenital diaphragmatic hernia (CDH) with hypoplastic lung is still poor in spite of recent progress of the therapy, lung growth in the period of fetus and newborn has been thought to be more important. Preliminary study indicated that adrenomedullin (AM) increased branching morphogenesis in a nitrophen-treated rat model of CDH. In this study, we examined an effect of AM gene transfer on growth of the lung in a rabbit model of CDH.Methods : Left-sided congenital diaphragmatic hernia was surgically created in fetuses of timed-pregnant New Zealand white rabbits on day 24 of gestation (term: 31 days). In control animals, laparotomy was performed on day 24 of gestation. Positively charged biodegradable gelatin was used to produce ionically linked DNA-gelatin complex that could delay DNA degradation. After an incision of the left diaphragm, experimental animals were underwent tracheal injection of AM DNA gelatin complex (AM-gelatin group), gelatin (gelatin group) and saline (saline group).Results : On day f 30 of gestation, lung-to-body weight ratio in AM gelatin group was significantly higher than that in gelatin and saline group, though that was significantly lower than that in controls. Pulmonary AM in AM gelatin group was significantly increased as compared to that in gelatin, saline and control group. Immunohistochemistry in AM gelatin group indicated strong staining of AM in the airway cells and vascular cells. AM m-RNA also increased in AM gelatin group.Conclusion : AM gene transfer induced therapeutic effects in a rabbit model of congenital diaphragmatic hernia.