Woolley Steven M, Farivar Alexander S, Naidu Babu V, Salzman Andrew, Szabo Csaba, Thomas Robert, Fraga Charles, Mulligan Michael S
Department of Cardiothoracic Surgery, University of Washington School of Medicine, Seattle, Washington 98195, USA.
J Heart Lung Transplant. 2004 Nov;23(11):1290-6. doi: 10.1016/j.healun.2003.08.036.
The activation of poly (adenosine diphosphate) ribose synthetase (PARS) is known to be important in the cellular response to oxidative stress. Previous studies have reported that PARS inhibition confers protection in models of endotoxic shock and ischemia-reperfusion. The purpose of this study was to determine the role of PARS inhibition in lung ischemia-reperfusion injury (LIRI).
Left lungs of Long-Evans rats were rendered ischemic for 90 minutes and reperfused for up to 4 hours. Treated animals received 3 mg/kg of INO-1001 (a PARS inhibitor) intravenously 30 minutes before ischemia. Injury was quantitated in terms of tissue myeloperoxidase (MPO) content, vascular permeability ((125)I radiolabeled bovine serum albumin extravasation) and bronchoalveolar lavage (BAL) leukocyte content. BAL fluid was assessed for cytokine and chemokine content by enzyme-linked immunoassay. Further samples were processed for nuclear protein analysis by electromobility shift assay (EMSA) and cellular death by terminal deoxyribonucleotidyl transferase-mediated d-UTP biotin nick-end labeling (TUNEL) assay and caspase-3 staining.
Lung vascular permeability was reduced in treated animals by 73% compared with positive controls (p < 0.009). The protective effects of PARS inhibition correlated with a 46% reduction in tissue MPO content (p < 0.008) and marked reductions in BAL leukocyte accumulation. This positively correlated with the diminished expression of pro-inflammatory mediators and nuclear transcription factors, as well as decreased levels of cellular death.
The deleterious effects of LIRI are in part mediated by the formation of free radicals and superoxides, which lead to DNA single-strand breaks. This leads to activation of PARS, which causes rapid cellular energy depletion and cell death. PARS inhibition is protective against this and represents a potentially useful therapeutic tool in the prevention of LIRI.
已知多聚（二磷酸腺苷）核糖合成酶（PARS）的激活在细胞对氧化应激的反应中起重要作用。先前的研究报道，PARS抑制在内毒素休克和缺血再灌注模型中具有保护作用。本研究的目的是确定PARS抑制在肺缺血再灌注损伤（LIRI）中的作用。
将Long-Evans大鼠的左肺缺血90分钟，再灌注长达4小时。治疗组动物在缺血前30分钟静脉注射3mg/kg的INO-1001（一种PARS抑制剂）。通过组织髓过氧化物酶（MPO）含量、血管通透性（（125）I放射性标记的牛血清白蛋白外渗）和支气管肺泡灌洗（BAL）白细胞含量来定量损伤。通过酶联免疫吸附测定法评估BAL液中的细胞因子和趋化因子含量。进一步的样本通过电泳迁移率变动分析（EMSA）进行核蛋白分析，并通过末端脱氧核苷酸转移酶介导的d-UTP生物素缺口末端标记（TUNEL）测定法和半胱天冬酶-3染色进行细胞死亡分析。
与阳性对照组相比，治疗组动物的肺血管通透性降低了73%（p<0.009）。PARS抑制的保护作用与组织MPO含量降低46%（p<0.008）以及BAL白细胞积聚的显著减少相关。这与促炎介质和核转录因子的表达减少以及细胞死亡水平降低呈正相关。
LIRI的有害作用部分由自由基和超氧化物的形成介导，这会导致DNA单链断裂。这会导致PARS激活，进而导致细胞能量迅速耗竭和细胞死亡。PARS抑制对此具有保护作用，是预防LIRI中一种潜在有用的治疗工具。
