Matrix Metalloproteinase-2 (MMP-2) Gene Deletion Enhances MMP-9 Activity, Impairs PARP-1 Degradation, and Exacerbates Hepatic Ischemia and Reperfusion Injury in Mice.
Hepatic ischemia and reperfusion injury (IRI) is an inflammatory condition and a significant cause of morbidity and mortality after surgery. Matrix metalloproteinases (MMPs) have been widely implicated in the pathogenesis of inflammatory diseases. Among the different MMPs, gelatinases (MMP-2 and MMP-9) are within the most prominent MMPs detected during liver IRI. While the role of MMP-9 in liver damage has been fairly documented, direct evidence of the role for MMP-2 activity in hepatic IRI remains to be established. Due to the lack of suitable inhibitors to target individual MMPs in vivo, gene manipulation is as an essential tool to assess MMP direct contribution to liver injury. Hence, we used MMP-2-/- deficient mice and MMP-2+/+ wild-type littermates to examine the function of MMP-2 activity in hepatic IRI. MMP-2 expression was detected along the sinusoids of wild-type livers before and after surgery and in a small population of leukocytes post-IRI. Compared to MMP-2+/+ mice, MMP-2 null (MMP-2-/-) mice showed exacerbated liver damage at 6, 24, and 48 hours post-reperfusion, which was fatal in some cases. MMP-2 deficiency resulted in upregulation of MMP-9 activity, spontaneous leukocyte infiltration in naïve livers, and amplified MMP-9-dependent transmigration of leukocytes in vitro and after hepatic IRI. Moreover, complete loss of MMP-2 activity impaired the degradation of poly (ADP-ribose) polymerase (PARP-1) in extensively damaged livers post-reperfusion. However, the administration of a PARP-1 inhibitor to MMP-2 null mice restored liver preservation to almost comparable levels of MMP-2+/+ mice post-IRI. Deficient PARP-1 degradation in MMP-2-null sinusoidal endothelial cells correlated with their increased cytotoxicity, evaluated by the measurement of LDH efflux in the medium. In conclusion, our results show for the first time that MMP-2 gene deletion exacerbates liver IRI. Moreover, they offer new insights into the MMP-2 modulation of inflammatory responses, which could be relevant for the design of new pharmacological MMP-targeted agents to treat hepatic IRI.
The Dumont-UCLA Transplant Center, Division of Liver and Pancreas Transplantation, Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States of America.
Hiroyuki
H
Kato
The Dumont-UCLA Transplant Center, Division of Liver and Pancreas Transplantation, Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States of America.
Sergio
S
Duarte
The Dumont-UCLA Transplant Center, Division of Liver and Pancreas Transplantation, Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States of America.
Daniel
D
Liu
The Dumont-UCLA Transplant Center, Division of Liver and Pancreas Transplantation, Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States of America.
Ronald W
RW
Busuttil
The Dumont-UCLA Transplant Center, Division of Liver and Pancreas Transplantation, Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States of America.
Ana J
AJ
Coito
D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D002465:Cell Movement / Q000235:genetics / Q000276:immunology; D016207:Cytokines / Q000378:metabolism; D004195:Disease Models, Animal; D004789:Enzyme Activation; D017353:Gene Deletion; D015870:Gene Expression; D018836:Inflammation Mediators / Q000378:metabolism; D007958:Leukocyte Count; D007962:Leukocytes / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D008099:Liver / Q000098:blood supply / Q000378:metabolism* / Q000473:pathology; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000235:genetics*; D020780:Matrix Metalloproteinase 9 / Q000235:genetics / Q000378:metabolism*; D061965:Matrix Metalloproteinase Inhibitors / Q000494:pharmacology; D051379:Mice; D018345:Mice, Knockout; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism*; D059748:Proteolysis; D015427:Reperfusion Injury / Q000235:genetics* / Q000378:metabolism* / Q000401:mortality / Q000473:pathology
D000911:Antibodies, Monoclonal; D016207:Cytokines; D018836:Inflammation Mediators; D061965:Matrix Metalloproteinase Inhibitors; C499321:Parp1 protein, mouse; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9