Soluble elastin decreases in the progress of atheroma formation in human aorta.
BACKGROUND
The serum levels of soluble elastin increase in patients with aortic dissection, but its distribution and characteristics are unclear.


RESULTS
The 173 aortic specimens were categorized into 4 groups under microscopy (non-atherosclerotic aorta, n=13; fiber-rich plaque, n=77; lipid-rich plaque, n=66; ruptured plaque, n=17). Soluble elastin was abundant within the intima of both the non-atherosclerotic aorta and fiber-rich plaque, rather than in the media, and was decreased within the intima of lipid-rich and ruptured plaques. Soluble elastin levels decreased with progress of atherosclerosis (6.0 +/-0.3 microg/mg protein in non-atherosclerotic aorta; 5.8 +/-0.2 microg/mg protein in fiber-rich plaque; 4.9 +/-0.2 microg/mg protein in lipid-rich plaque; 2.8 +/-0.4 microg/mg protein in ruptured plaque, P<0.05). As well, both matrix metalloprotease-9 activity and elastin mRNA expression showed inverse distribution against soluble elastin (r=0.437, P<0.0001; r=0.186, P<0.05, respectively). Multivariable analysis revealed a decrease in the level of soluble elastin in ruptured plaque (2.8 +/-0.4 microg/mg protein in ruptured plaque, n=18; 5.5 +/-0.2 microg/mg protein in non-ruptured plaque, n=155, P<0.01). Furthermore, western blot showed soluble elastin consists of heterogeneous molecular pattern proteins.


CONCLUSIONS
Both the synthesis and degradation of elastin may be enhanced in active atherosclerotic lesions.
Akima
Takashi
T
Department of Pathology and Laboratory Medicine, National Defense Medical College, Tokorozawa, Japan.
Nakanishi
Kuniaki
K
Suzuki
Kimihiro
K
Katayama
Masahiko
M
Ohsuzu
Fumitaka
F
Kawai
Toshiaki
T
D000368:Aged; D000369:Aged, 80 and over; D001011:Aorta / Q000378:metabolism* / Q000473:pathology; D050197:Atherosclerosis / Q000209:etiology* / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D001483:Base Sequence; D015153:Blotting, Western; D017931:DNA Primers / Q000235:genetics; D004549:Elastin / Q000235:genetics / Q000378:metabolism*; D005260:Female; D006801:Humans; D017403:In Situ Hybridization; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D008875:Middle Aged; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012995:Solubility; D014018:Tissue Distribution
D017931:DNA Primers; D012333:RNA, Messenger; D004549:Elastin; D020780:Matrix Metalloproteinase 9