Marruchella G, Giacominelli-Stuffler R, Baffoni M, Maccarrone M
Department of Comparative Biomedical Sciences, University of Teramo, Teramo, Italy.
J Comp Pathol. 2010 Feb-Apr;142(2-3):139-46. doi: 10.1016/j.jcpa.2009.09.004. Epub 2009 Nov 10.
Eicosanoids are products of arachidonic acid metabolism and have numerous biological roles. The present study aimed to investigate the role of 5-lipoxygenase (5-LOX)- and cyclooxygenase-2 (COX-2)- dependent enzymatic pathways in the pathogenesis of porcine parasitic bronchopneumonia caused by Metastrongylus spp. Pulmonary tissue samples from healthy control and parasitized pigs were processed for histopathological, immunohistochemical and biochemical investigations. In control animals, immunohistochemistry demonstrated that 5-LOX and COX-2 expression was almost exclusively limited to the bronchiolar epithelial cells. Parasitized pigs had greater 5-LOX- and COX-2- specific immunoreactivity, involving a wide range of cell types within foci of granulomatous and eosinophilic bronchopneumonia. Biochemical investigations demonstrated the presence of 5-LOX (and the related product Leukotriene B(4)) and COX-2 (and the related product prostaglandin E(2); PGE(2)) in all tissues under study. COX-2 activity and PGE(2) concentration were significantly higher in diseased lungs compared with normal healthy controls. These findings demonstrate that 5-LOX and COX-2 are differentially expressed in normal versus lungworm-infected lungs and therefore suggest that both biochemical pathways are likely to be involved in the pathogenesis of porcine parasitic bronchopneumonia.
类二十烷酸是花生四烯酸代谢产物，具有多种生物学作用。本研究旨在探讨5-脂氧合酶（5-LOX）和环氧化酶-2（COX-2）依赖性酶促途径在由后圆线虫属引起的猪寄生性支气管肺炎发病机制中的作用。对来自健康对照猪和感染寄生虫猪的肺组织样本进行组织病理学、免疫组织化学和生化研究。在对照动物中，免疫组织化学显示5-LOX和COX-2表达几乎仅局限于细支气管上皮细胞。感染寄生虫的猪具有更强的5-LOX和COX-2特异性免疫反应性，涉及肉芽肿性和嗜酸性支气管肺炎病灶内的多种细胞类型。生化研究表明，在所研究的所有组织中均存在5-LOX（以及相关产物白三烯B4）和COX-2（以及相关产物前列腺素E2；PGE2）。与正常健康对照相比，患病肺组织中的COX-2活性和PGE2浓度显著更高。这些发现表明，5-LOX和COX-2在正常肺与感染肺线虫的肺中差异表达，因此提示这两条生化途径可能均参与猪寄生性支气管肺炎的发病机制。
