Lin Xuguang, Kuragano Masahiro, Watanabe Kenichi, Tokuraku Kiyotaka
13317Muroran Institute of Technology, Muroran, Japan.
52746Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Japan.
Vet Pathol. 2021 Mar;58(2):369-375. doi: 10.1177/0300985820970490. Epub 2020 Nov 18.
Amyloid fibrils are characterized by a linear morphology and a cross-β structure. Polymorphic and multiple fibril morphologies can be found when amyloid fibrils are extracted from amyloid-laden tissue. In this study, we report on the purification and transmission electron microscopic analysis of amyloid fibrils from 5 different animal species (mouse, cow, goat, dog, and camel) with AA amyloidosis. The results show that amyloid fibrils had a linear morphology with a cross-structure and irregular length in vivo. Although the fibrils from these different species showed highly similar conformations, there were significant differences in fibril width and crossover distance. We analyzed the sequences of homologous amyloid proteins and serum amyloid A, an evolutionarily conserved protein and a major amyloid precursor. We found 78.23% homology between the most distant amyloid proteins. The findings suggested similar fibril width and crossover distance in different animal species that displayed high homology of amyloid protein sequences. Dog and camel, as well as goat and cow, showed high genetic homology and similar fibril morphology. These data indicate that the fibrils from different animal species have similar genetic homology and morphology, which may provide a better understanding of the pathogenesis of amyloidosis.
淀粉样纤维的特征在于线性形态和交叉β结构。当从富含淀粉样蛋白的组织中提取淀粉样纤维时，可以发现多态性和多种纤维形态。在本研究中，我们报告了来自5种患有AA淀粉样变性的不同动物物种（小鼠、牛、山羊、狗和骆驼）的淀粉样纤维的纯化及透射电子显微镜分析。结果表明，淀粉样纤维在体内具有线性形态、交叉结构且长度不规则。尽管来自这些不同物种的纤维显示出高度相似的构象，但在纤维宽度和交叉距离上存在显著差异。我们分析了同源淀粉样蛋白和血清淀粉样蛋白A（一种进化上保守的蛋白且是主要的淀粉样前体）的序列。我们发现，在亲缘关系最远的淀粉样蛋白之间存在78.23%的同源性。这些发现表明，在淀粉样蛋白序列具有高度同源性的不同动物物种中，纤维宽度和交叉距离相似。狗和骆驼，以及山羊和牛，显示出高度的遗传同源性和相似的纤维形态。这些数据表明，来自不同动物物种的纤维具有相似的遗传同源性和形态，这可能有助于更好地理解淀粉样变性的发病机制。
