Arterial enlargement in response to high flow requires early expression of matrix metalloproteinases to degrade extracellular matrix.
This study investigated the effects of high flow and shear stress on the expression of matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinase-2 (TIMP-2) during flow-induced arterial enlargement using a model of arteriovenous fistula (AVF) creation on the carotid artery with the corresponding jugular vein in Japanese white male rabbits. Flow increased 8-fold 7 days after AVF. Endothelial cells (EC) and smooth muscle cells (SMC) proliferated with internal elastic lamina (IEL) degradation in response to high flow and shear stress. Expression of MMP-2 mRNA peaked at 2 days (1700-fold) and maintained high level expression. MMP-9 mRNA gave a 10.8-fold increase within 2 days and decreased later. Their proteins were detected in EC and SMC. Membrane type-1-MMP (MT1-MMP) mRNA increased 121-fold at 3 days and maintained high expression. TGF-beta1 was increased after AVF. Two-peak up-regulation of Egr-1 mRNA was recognized at 1 and 5 days of AVF. These results suggest that high flow and shear stress can mediate EC and SMC to express MMP-2 and MMP-9, which degrade cell basement membranes and IEL to induce arterial enlargement. The disproportional increase in MT1-MMP and TIMP-2 might contribute to MMP-2 activation. Egr-1 and TGF-beta1 might play important roles in this process.
Sho
Eiketsu
E
Department of Surgery, Stanford University School of Medicine, Stanford, California 94305-5642, USA.
Sho
Mien
M
Singh
Tej M
TM
Nanjo
Hiroshi
H
Komatsu
Masayo
M
Xu
Chengpei
C
Masuda
Hirotake
H
Zarins
Christopher K
CK
D000818:Animals; D001158:Arteries / Q000033:anatomy & histology* / Q000201:enzymology*; D001164:Arteriovenous Fistula; D001783:Blood Flow Velocity; D002339:Carotid Arteries / Q000033:anatomy & histology / Q000201:enzymology / Q000502:physiology / Q000601:surgery; D004730:Endothelium, Vascular / Q000254:growth & development / Q000648:ultrastructure; D005109:Extracellular Matrix / Q000378:metabolism*; D007601:Jugular Veins / Q000502:physiology / Q000601:surgery; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000096:biosynthesis / Q000235:genetics; D020780:Matrix Metalloproteinase 9 / Q000096:biosynthesis / Q000235:genetics; D020782:Matrix Metalloproteinases / Q000096:biosynthesis* / Q000235:genetics; D009130:Muscle, Smooth / Q000254:growth & development / Q000648:ultrastructure; D012333:RNA, Messenger / Q000378:metabolism; D011817:Rabbits; D012039:Regional Blood Flow; D013314:Stress, Mechanical; D013997:Time Factors; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000096:biosynthesis / Q000235:genetics; D016212:Transforming Growth Factor beta / Q000096:biosynthesis; D015854:Up-Regulation
D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D019716:Tissue Inhibitor of Metalloproteinase-2; D020782:Matrix Metalloproteinases; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9