In situ localization and quantification of mRNA for 92-kD type IV collagenase and its inhibitor in aneurysmal, occlusive, and normal aorta.
Ninety-two-kilodalton type IV collagenase (MMP-9) is present in aortic aneurysms and may be important to the pathogenesis of this disease. Alteration in expression of MMP-9 or its inhibitor, the tissue inhibitor of metalloproteinase type 1 (TIMP-1), could increase degradation of extracellular matrix and lead to aneurysm formation. The purpose of this study was (1) to measure tissue levels of MMP-9 and TIMP-1 mRNA in aneurysmal (AAA), atherosclerotic occlusive (AOD), and normal (NL) human infrarenal aorta; (2) to test for their expression by cultured AAA and NL vascular smooth muscle cells (VSMCs); and (3) to locate in situ the cells responsible for mRNA production within AAA, AOD, and NL aortic wall. Total RNA extracted from AAA (n = 8), AOD (n = 8), and NL (n = 7) tissue was subjected to Northern analysis. Signals for MMP-9 and TIMP-1 were normalized to alpha-tubulin. Mean values +/- SEM were compared by ANOVA. NL and AAA VSMCs were cultured, passaged, and grown to confluence before RNA extraction and Northern analysis. In situ hybridization with digoxigenin-labeled RNA probes localized cells responsible for MMP-9 and TIMP-1 mRNA expression within sections of AAA (n = 5), AOD (n = 2), and NL (n = 2) aorta. MMP-9 mRNA levels were significantly greater in AAA (0.855 +/- 0.180) than NL (0.046 +/- 0.23) (P < .02), but differences between AOD (0.406 +/- 0.196) and AAA or AOD and NL were not significant.(ABSTRACT TRUNCATED AT 250 WORDS)
McMillan
W D
WD
Department of Surgery, Northwestern University Medical School, Chicago, Ill, USA.
Patterson
B K
BK
Keen
R R
RR
Shively
V P
VP
Cipollone
M
M
Pearce
W H
WH
D000783:Aneurysm / Q000235:genetics; D001011:Aorta / Q000201:enzymology*; D002478:Cells, Cultured; D017364:Collagenases / Q000235:genetics*; D015870:Gene Expression; D006023:Glycoproteins / Q000235:genetics*; D006801:Humans; D017403:In Situ Hybridization; D066298:In Vitro Techniques; D020780:Matrix Metalloproteinase 9; D009131:Muscle, Smooth, Vascular / Q000201:enzymology; D012333:RNA, Messenger / Q000235:genetics; D019714:Tissue Inhibitor of Metalloproteinases
D006023:Glycoproteins; D012333:RNA, Messenger; D019714:Tissue Inhibitor of Metalloproteinases; D017364:Collagenases; D020780:Matrix Metalloproteinase 9