Plasma MMP-2 and MMP-9 and their inhibitors TIMP-1 and TIMP-2 during human orthotopic liver transplantation. The effect of aprotinin and the relation to ischemia/reperfusion injury.
Uncontrolled activation of matrix metalloproteinases (MMPs) can result in tissue injury and inflammation, yet little is known about the activation of MMPs during orthotopic liver transplantation (OLT). OLT is associated with increased fibrinolytic activity due to elevated plasmin generation. The serine-protease plasmin not only causes degradation of fibrin clots but is also thought, amongst others, to play a role in the activation of some matrix metalloproteinases. We therefore studied the evolution of MMP-2 and -9 plasma concentrations during OLT and the effect of serine-protease inhibition by aprotinin on the level and activation of these MMPs. In a group of 24 patients who participated in a randomized, double-blind, placebo-controlled study we determined serial MMP-2 and MMP-9 plasma levels during transplantation using ELISA (total MMP), activity assays (activatable MMP) and zymography. In addition, the MMP-inhibitors TIMP-1 and TIMP-2 were assessed by ELISA. The putative regulating factors tumor necrosis factor alpha (TNF-alpha) and tissue-type plasminogen activator (t-PA) were assessed as well. Patients were administered high-dose aprotinin, regular-dose aprotinin or placebo during surgery. Plasma TIMP-1, TIMP-2 and MMP-2 level gradually decreased during transplantation. Approximately two-thirds of total MMP-2 appeared to be in its activatable proMMP form. No release of MMP-2 from the graft could be detected. In contrast, plasma levels of MMP-9 increased sharply during the anhepatic and postreperfusion periods. Peak MMP-9 levels of about eight times above baseline were found at 30 minutes after reperfusion. Most MMP-9 appeared to be in its active/inhibitor-complexed form. No significant differences were observed between the three treatment groups. However, in patients with more severe ischemia/reperfusion (I/R) injury the MMP-9 concentration, particularly of the active/inhibitor-complexed form, remained high at 120 minutes postreperfusion compared to patients with no or mild I/R injury. The decrease in plasma levels of MMP-2, TIMP-1 and TIMP-2 during OLT occurred irrespective of the severity of the I/R injury. There was a significant correlation between MMP-9 and t-PA levels, but not with TNF-alpha. In conclusion, OLT is associated with a sharp increase of MMP-9 during the anhepatic and postreperfusion periods, which coincided with the changes in t-PA. MMP-2, TIMP-1 and TIMP-2 gradually decreased during OLT. The composition of these MMPs was not altered by the use of aprotinin, suggesting that serine-protease/plasmin-independent pathways are responsible for MMP regulation during OLT. In addition, only MMP-9 seems to be involved in I/R injury during human liver transplantation.
Department of Gastroenterology and Hepatology, Leiden University Medical Center, C4-P, PO. Box 9600, 2300 RC Leiden, The Netherlands.
Johan Ph
JP
Kuyvenhoven
I Quintus
IQ
Molenaar
Hein W
HW
Verspaget
Marietta G
MG
Veldman
Gualtiero
G
Palareti
Cristina
C
Legnani
Sanne E
SE
Moolenburgh
Onno T
OT
Terpstra
Cornelis B H W
CB
Lamers
Bart
B
van Hoek
Robert J
RJ
Porte
D000293:Adolescent; D000328:Adult; D000368:Aged; D007611:Aprotinin / Q000494:pharmacology*; D001219:Aspartate Aminotransferases / Q000097:blood; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D016031:Liver Transplantation; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000097:blood*; D020780:Matrix Metalloproteinase 9 / Q000097:blood*; D008875:Middle Aged; D010919:Placebos; D015427:Reperfusion Injury; D013997:Time Factors; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000097:blood*; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000097:blood*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D010919:Placebos; D019715:Tissue Inhibitor of Metalloproteinase-1; D014409:Tumor Necrosis Factor-alpha; D019716:Tissue Inhibitor of Metalloproteinase-2; D007611:Aprotinin; D001219:Aspartate Aminotransferases; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9