Peng Siwei, Glennert Johanna, Westermark Per
Department of Genetics and Pathology, Uppsala University, Sweden.
Amyloid. 2005 Jun;12(2):96-102. doi: 10.1080/13506120500107006.
Amyloid deposition occurs commonly in the aging aortic media. We recently found that a 50 amino acid amyloid fibril protein, which we called medin, forms the fibrils of this amyloid form. Medin is an internal fragment of the 364 long precursor lactadherin, which is expressed by several kinds of cells including vascular smooth muscle cells. With the use of specific antibodies we have now studied the vascular distribution of medin (AMed) amyloid in a series of 18 individuals, 57 years of age and older. All individuals had widely spread AMed amyloid in the media of the thoracic aorta while this type of amyloid occurred less commonly in the abdominal aorta. In 8 of the 18 individuals, AMed-amyloid was also found in the basilar artery while the frequency was lower in other studied arteries. Amyloid was usually seen in close association with the internal elastic lamina. Analysis of proteins extracted from amyloid-rich aortic media showed presence of both lactadherin and medin. This study shows that AMed amyloid is not restricted to the aorta and the temporal artery but also occurs in other arteries, mainly in the upper part of the body. AMed amyloid has to be added to the forms of amyloid that may be seen in intracranial vessels.
淀粉样沉积常见于衰老的主动脉中膜。我们最近发现一种由50个氨基酸组成的淀粉样纤维蛋白（我们称之为medin）构成了这种淀粉样物质的纤维。Medin是364个氨基酸长的前体乳酸粘附素的内部片段，乳酸粘附素由包括血管平滑肌细胞在内的多种细胞表达。我们使用特异性抗体，对18名57岁及以上个体的medin（AMed）淀粉样物质的血管分布进行了研究。所有个体的胸主动脉中膜均广泛存在AMed淀粉样物质，而这种类型的淀粉样物质在腹主动脉中较少见。18名个体中有8名在基底动脉中也发现了AMed淀粉样物质，而在其他研究的动脉中其出现频率较低。淀粉样物质通常与内弹性膜紧密相连。对富含淀粉样物质的主动脉中膜提取的蛋白质进行分析，结果显示同时存在乳酸粘附素和medin。这项研究表明，AMed淀粉样物质不仅局限于主动脉和颞动脉，也存在于其他动脉中，主要分布在身体上部。AMed淀粉样物质必须被纳入可能在颅内血管中出现的淀粉样物质类型中。
