The membrane attack complex (C5b-9) in liver cold ischemia and reperfusion injury.
Activation of the complement cascade represents an important event during ischemia/reperfusion injury (IRI). This work was designed to investigate the role of the membrane attack complex (MAC; C5b-9) in the pathogenesis of hepatic IRI. Livers from B&W/Stahl/rC6(+) and C6(-) rats were harvested, stored for 24 hours at 4 degrees C, and then transplanted [orthotopic liver transplantation (OLT)] to syngeneic recipients. There were 4 experimental groups: (1) C6(+)-->C6(+), (2) C6(+)-->C6(-), (3) C6(-)-->C6(+), and (4) C6(-)-->C6(-). At day +1, C6(-) OLTs showed decreased vascular congestion/necrosis, contrasting with extensive necrosis in C6(+) livers, that was independent of the recipient C6 status (Suzuki score: 7.2 +/- 0.9, 7.3 +/- 1.3, 4.5 +/- 0.6, and 4.8 +/- 0.4 for groups 1-4, respectively, P < 0.05). The liver function improved in recipients of C6(-) grafts (serum glutamic oxaloacetic transaminase: 2573 +/- 488, 1808 +/- 302, 1170 +/- 111, and 1188 +/- 184 in groups 1-4, respectively, P < 0.05). Intragraft macrophage infiltration (ED-1 immunostaining) and neutrophil infiltration (myeloperoxidase activity) were reduced in C6(-) grafts versus C6(+) grafts (P = 0.001); these data were confirmed by esterase staining (naphthol). The expression of proinflammatory interferon-gamma, interleukin-1beta, and tumor necrosis factor messenger RNA/protein was also reduced in C6(-) OLTs in comparison with C6(+) OLTs. Western blot-assisted expression of proapoptotic caspase-3 was decreased in C6(-) OLTs versus C6(+) OLTs (P = 0.006), whereas antiapoptotic Bcl-2/Bag-1 was enhanced in C6(-) OLTs compared with C6(+) OLTs (P = 0.001). Terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling staining of apoptotic cells was enhanced (P < 0.05) in C6(+) OLTs compared with C6(-) OLTs. Thus, the terminal products of the complement system are essential in the mechanism of hepatic IRI. This is the first report using a clinically relevant liver cold ischemia model to show that local MAC inhibition attenuates IRI cascade in OLT recipients.
Fondevila
Constantino
C
Dumont-University of California at Los Angeles Transplant Center, Division of Liver and Pancreas Transplantation, Department of Surgery, David Geffen School of Medicine at the University of California at Los Angeles, Los Angeles, CA 90095, USA.
Shen
Xiu-Da
XD
Tsuchihashi
Seiichiro
S
Uchida
Yoichiro
Y
Freitas
Maria Cecilia
MC
Ke
Bibo
B
Busuttil
Ronald W
RW
Kupiec-Weglinski
Jerzy W
JW
D000818:Animals; D017209:Apoptosis; D050377:Cold Ischemia; D003183:Complement C6 / Q000172:deficiency* / Q000235:genetics; D015938:Complement Membrane Attack Complex / Q000378:metabolism*; D016207:Cytokines / Q000378:metabolism; D005260:Female; D008099:Liver / Q000473:pathology; D008107:Liver Diseases / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D016031:Liver Transplantation / Q000276:immunology / Q000473:pathology; D008264:Macrophages / Q000502:physiology; D020556:Neutrophil Infiltration; D051381:Rats; D015427:Reperfusion Injury / Q000276:immunology / Q000378:metabolism* / Q000473:pathology
D003183:Complement C6; D015938:Complement Membrane Attack Complex; D016207:Cytokines