Protein identification by LMD-MS/MS.

Amyloidosis is a group of protein misfolding diseases and a well-recognized disorder in avian species. However, the knowledge of wild avian amyloid proteome is scarce. We report here gross, histopathological, ultrastructural, immunohistochemical and proteomic findings of systemic amyloidosis in seven Eurasian stone-curlews (Burhinus oedicnemus) necropsied in the Canary Islands. Spleen (5/6–83.33%), liver (3/5–60%), kidney (3/5–60%), proventricle (3/5–60%) and intestine (3/6–50%) were the more severely affected organs. All cases underwent chronic inflammatory processes associated to helminth, bacteria or fungi infection. Verminous chronic ventriculitis was the most frequent associated pathology in 5/7 (71.43%) followed by bumblefoot in 2/7 (28.57%) cases. Electron microscopy revealed a predominantly amorphous substance with 10 nm diameter non-branching amyloid fibrils. AA amyloidosis was characterized by immunohistochemistry and mass spectrometry analysis. By mass spectrometry three amyloid signature proteins were also identified: vitronectin, apolipoprotein A-IV and apolipoprotein A-I in 6/7 (85.71%), 4/7 (57.14%), and 3/7 (42.86%) cases, respectively, contributing with new knowledge about the amyloid proteome of amyloidosis in wild avian species.

淀粉样变（Amyloidosis）是一组蛋白质错误折叠疾病，亦是鸟类中一类已被广泛认知的病症。然而，当前学界对野生鸟类淀粉样蛋白质组（amyloid proteome）的认知仍较为匮乏。本研究报道了在加那利群岛（Canary Islands）经尸体解剖的7只欧亚石鸻（Burhinus oedicnemus）的全身性淀粉样变的大体观察、组织病理学、超微结构、免疫组织化学及蛋白质组学研究结果。受累最为严重的器官依次为脾脏（5/6–83.33%）、肝脏（3/5–60%）、肾脏（3/5–60%）、腺胃（proventricle）（3/5–60%）与肠道（intestine）（3/6–50%）。所有病例均存在与蠕虫、细菌或真菌感染相关的慢性炎症病变，其中蠕虫性慢性腺胃炎（verminous chronic ventriculitis）为最常见的伴随病变，见于5/7（71.43%）的病例，其次为脚垫病（bumblefoot），检出率为2/7（28.57%）。电子显微镜观察显示，病变部位主要存在无定形物质及直径为10nm的无分支淀粉样原纤维（amyloid fibrils）。AA型淀粉样变（AA amyloidosis）通过免疫组织化学与质谱分析得以明确鉴定。通过质谱分析，本研究还鉴定出3种淀粉样特征蛋白：玻连蛋白（vitronectin）、载脂蛋白A-IV（apolipoprotein A-IV）与载脂蛋白A-I（apolipoprotein A-I），其检出率分别为6/7（85.71%）、4/7（57.14%）及3/7（42.86%），该研究为野生鸟类淀粉样变的淀粉样蛋白质组研究提供了新的科学认知。