Abdominal aortic aneurysm is associated with high serum levels of tenascin-X and decreased aneurysmal tissue tenascin-X.
BACKGROUND
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.


RESULTS
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).


CONCLUSIONS
Tenascin-X expression is markedly decreased in AAA tissue, and AAA is associated with high serum concentrations of tenascin-X.
Department of Dermatology, Nijmegen Centre for Molecular Life Sciences, Nijmegen, The Netherlands.
Manon C
MC
Zweers
Anita C T M
AC
Peeters
Sietze
S
Graafsma
Steef
S
Kranendonk
J Adam
JA
van der Vliet
Martin
M
den Heijer
Joost
J
Schalkwijk
D000368:Aged; D000369:Aged, 80 and over; D001011:Aorta / Q000378:metabolism; D001012:Aorta, Abdominal / Q000378:metabolism*; D017544:Aortic Aneurysm, Abdominal / Q000097:blood / Q000378:metabolism*; D016022:Case-Control Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D008875:Middle Aged; D009994:Osmolar Concentration; D019063:Tenascin / Q000097:blood / Q000378:metabolism*; D014018:Tissue Distribution
D019063:Tenascin; C081865:tenascin X