Ohata T, Sawa Y, Takagi M, Inoue T, Yoshida T, Kogaki S, Matsuda H
First Department of Surgery, Osaka University Medical School, Japan.
Circulation. 1998 Nov 10;98(19 Suppl):II269-74.
Recently, the research on hybrid artificial organs such as heart, liver, and kidney has been reported to yield new possibilities for clinical use. However, there have been few reports on the practical use of a hybrid artificial lung, primarily due to difficulties in the concept for its application and techniques for cell attachment. In this study, we investigated the possibility for developing a novel strategy: a hybrid artificial lung with constitutive nitric oxide synthase (NOS) and interleukin (IL)-10 gene-transfected endothelial cells to attenuate inflammatory reactions induced by cardiopulmonary bypass.
First, we performed an in vitro study to confirm the efficacy of our gene transfection into endothelial cells. Constitutive nitric oxide synthase and IL-10 cDNA were transfected into endothelial cells according to the hemagglutinating virus of Japan-liposome method. Levels of nitric oxide released from the endothelial constitutive NOS (ecNOS)-transfected endothelial cells were significantly higher than those of control cells (24 hours after the stimulation by lipopolysaccharide: 284.5 +/- 54.0 versus 95.7 +/- 27.9 mumol/L, P = 0.0001). On the other hand, IL-8 levels in the transfected endothelial cells were significantly lower than those in the control group (48 hours after stimulation by tumor necrosis factor-alpha: 3.1 +/- 2.4 versus 62.1 +/- 1.3 ng/mL, P = 0.0002), and IL-10 was detected in the transfected group but not in the control group. Next, we performed an in vivo study to evaluate the possibility of developing a hybrid artificial lung. One-hour partial cardiopulmonary bypass with this lung was established in rats undergoing femorofemoral bypass. Artificial lungs with no cells (group C; n = 5), that were coated with untreated endothelial cells (group E; n = 5), or that were coated with ecNOS and IL-10 gene-transfected endothelial cells (group T; n = 3) were used. At 45 minutes after the initiation of cardiopulmonary bypass, group T showed higher nitric oxide levels than groups C and E (T versus C versus E: 75.2 +/- 6.8 versus 67.2 +/- 4.3 versus 68.6 +/- 5.2 mumol/L, P = NS). The serum IL-8 levels just after cardiopulmonary bypass in group T were significantly lower than those in group C (1728 +/- 282 versus 4275 +/- 145 pg/mL, P = 0.0151). The Pao2 levels in group T just after weaning from cardiopulmonary bypass were significantly higher than those in group C (271.3 +/- 41.7 versus 136.6 +/- 12.3 mm Hg, P = 0.0362).
These results demonstrate that a hybrid artificial lung with IL-10 and ecNOS gene-transfected endothelial cells inhibited IL-8 release and increased nitric oxide production. This suggests the possibility of developing a hybrid artificial lung capable of preserving native lung function by attenuating cardiopulmonary bypass-induced inflammatory reactions via inhibition of IL-8 release and enhanced nitric oxide production.
最近，有报道称对心脏、肝脏和肾脏等混合人工器官的研究为临床应用带来了新的可能性。然而，关于混合人工肺实际应用的报道很少，主要是由于其应用概念和细胞附着技术存在困难。在本研究中，我们探讨了开发一种新策略的可能性：构建一种具有组成型一氧化氮合酶（NOS）和白细胞介素（IL）-10基因转染内皮细胞的混合人工肺，以减轻体外循环引起的炎症反应。
首先，我们进行了一项体外研究，以确认基因转染到内皮细胞中的效果。根据日本血凝病毒-脂质体法，将组成型一氧化氮合酶和IL-10 cDNA转染到内皮细胞中。内皮组成型NOS（ecNOS）转染的内皮细胞释放的一氧化氮水平显著高于对照细胞（脂多糖刺激后24小时：284.5±54.0对95.7±27.9μmol/L，P = 0.0001）。另一方面，转染内皮细胞中的IL-8水平显著低于对照组（肿瘤坏死因子-α刺激后48小时：3.1±2.4对62.1±1.3 ng/mL，P = 0.0002），并且在转染组中检测到IL-10，而对照组中未检测到。接下来，我们进行了一项体内研究，以评估开发混合人工肺的可能性。在接受股-股旁路手术的大鼠中建立了使用该肺进行1小时部分体外循环。使用无细胞的人工肺（C组；n = 5）、涂有未处理内皮细胞的人工肺（E组；n = 5）或涂有ecNOS和IL-10基因转染内皮细胞的人工肺（T组；n = 3）。在体外循环开始后45分钟，T组的一氧化氮水平高于C组和E组（T组对C组对E组：75.2±6.8对67.2±4.3对68.6±5.2μmol/L，P =无显著差异）。体外循环刚结束时，T组的血清IL-8水平显著低于C组（1728±282对4275±145 pg/mL，P = 0.0151）。体外循环撤机后即刻，T组的动脉血氧分压水平显著高于C组（271.3±41.7对136.6±12.3 mmHg，P = 0.0362）。
这些结果表明，具有IL-10和ecNOS基因转染内皮细胞的混合人工肺可抑制IL-8释放并增加一氧化氮生成。这表明有可能开发一种混合人工肺，通过抑制IL-8释放和增强一氧化氮生成来减轻体外循环引起的炎症反应，从而保护天然肺功能。
