Surgical handling of saphenous vein grafts induces expression of matrix metalloproteinase 9.
OBJECTIVE
To investigate whether human veins responded to surgical handling with acute remodelling by measuring matrix metalloproteinase 9 (MMP9) expression and activity.


METHODS
Saphenous veins were collected from 24 patients (12 stable angina, 12 unstable angina) undergoing coronary artery bypass grafting. Expression of MMP9 and its regulators (plasminogen activators, plasminogen activator inhibitor-1, tissue inhibitor of metalloproteinase-1) was evaluated by semiquantitative RT-PCR in veins sampled at the start of and after surgical preparation, while protein was detected by western blotting. The proteolytic activity of MMP9 was analyzed by zymography.


RESULTS
Gene (p=0.01) and protein (p=0.001) expression of MMP9 increased after surgical manipulation of vein grafts in all patients, accompanied by increased pro-MMP9 (p=0.04), but not active MMP9 (p=0.6). Grafts from stable patients had increased gene (p=0.05) and protein (p=0.006) expression, as well as increased pro- (p=0.04) and active (p=0.04) MMP9. Grafts from unstable patients increased only in MMP9 protein expression (p=0.05). The MMP9 regulators were unchanged.


CONCLUSIONS
Surgical handling of vein grafts increased expression and activity of MMP9. However, the surgery-induced increase was attenuated in veins from unstable patients.
Chen
Fei
F
King Gustaf V:s Research Institute, Karolinska Institute, Stockholm, Sweden.
Eriksson
Per
P
Whatling
Carl
C
Vaage
Jarle
J
Valen
Guro
G
D000787:Angina Pectoris / Q000378:metabolism*; D000789:Angina, Unstable / Q000378:metabolism; D015153:Blotting, Western; D001026:Coronary Artery Bypass; D005260:Female; D015870:Gene Expression; D006801:Humans; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000096:biosynthesis*; D017395:Plasminogen Activator Inhibitor 1 / Q000378:metabolism; D010960:Plasminogen Activators / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012501:Saphenous Vein / Q000378:metabolism* / Q000601:surgery*; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000378:metabolism
D017395:Plasminogen Activator Inhibitor 1; D019715:Tissue Inhibitor of Metalloproteinase-1; D010960:Plasminogen Activators; D020780:Matrix Metalloproteinase 9