Zweers Manon C, Peeters Anita C T M, Graafsma Sietze, Kranendonk Steef, van der Vliet J Adam, den Heijer Martin, Schalkwijk Joost
Department of Dermatology, Nijmegen Centre for Molecular Life Sciences, Nijmegen, The Netherlands.
Circulation. 2006 Apr 4;113(13):1702-7. doi: 10.1161/CIRCULATIONAHA.104.513820. Epub 2006 Mar 27.
Tenascin-X is a large extracellular matrix protein that is abundantly expressed in several connective tissues. A 140-kDa C-terminal fragment of tenascin-X is present in human serum. Complete deficiency of tenascin-X is associated with Ehlers-Danlos syndrome, and these patients show major connective tissue alterations in their skin, as well as blood vessel fragility. In this study, we investigated whether tenascin-X is present in normal human aorta and abdominal aortic aneurysm (AAA) tissues and whether an association exists between serum tenascin-X levels and AAA.
Five normal aortas and 5 AAA tissues were immunostained for tenascin-X and elastin. Tenascin-X was present throughout the entire aorta and was especially abundant near the elastic lamellae, whereas tenascin-X expression was strongly decreased in AAA tissue. Measurement of tenascin-X serum concentration by enzyme-linked immunosorbent assay (ELISA) in 87 AAA patients and 86 controls demonstrated an increasing risk for AAA with increasing tenascin-X serum concentrations. After adjustment for established risk factors, tenascin-X serum concentrations in the highest quartile were associated with a 5-fold increase in risk of AAA (odds ratio, 5.3; 95% confidence interval, 2.0 to 13.8).
Tenascin-X expression is markedly decreased in AAA tissue, and AAA is associated with high serum concentrations of tenascin-X.
腱生蛋白-X是一种大型细胞外基质蛋白，在多种结缔组织中大量表达。腱生蛋白-X的一个140 kDa C末端片段存在于人体血清中。腱生蛋白-X的完全缺乏与埃勒斯-当洛综合征相关，这些患者的皮肤出现主要的结缔组织改变，以及血管脆性增加。在本研究中，我们调查了腱生蛋白-X是否存在于正常人体主动脉和腹主动脉瘤（AAA）组织中，以及血清腱生蛋白-X水平与AAA之间是否存在关联。
对5个正常主动脉和5个AAA组织进行腱生蛋白-X和弹性蛋白免疫染色。腱生蛋白-X存在于整个主动脉中，在弹性板附近尤其丰富，而在AAA组织中腱生蛋白-X表达明显降低。通过酶联免疫吸附测定（ELISA）测量87例AAA患者和86例对照的血清腱生蛋白-X浓度，结果显示随着血清腱生蛋白-X浓度升高，患AAA的风险增加。在对既定风险因素进行校正后，最高四分位数的血清腱生蛋白-X浓度与AAA风险增加5倍相关（优势比，5.3；95%置信区间，2.0至13.8）。
AAA组织中腱生蛋白-X表达明显降低，且AAA与血清腱生蛋白-X高浓度相关。
