Inhibiting the complement system does not reduce injury in renal ischemia reperfusion

• Published in: Journal of the American Society of Nephrology Vol. 12; no. 7; pp. 1383 - 1390
• Main Authors: PARK, Pierce, HAAS, Mark, CUNNINGHAM, Patrick N, ALEXANDER, Jessy J, LIHUA BAO, GUTHRIDGE, Joel M, KRAUS, Damian M, HOLERS, V. Michael, QUIGG, Richard J
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD Lippincott Williams & Wilkins 01-07-2001
• Subjects: Animals; Biological and medical sciences; Complement C3 - deficiency; Complement C3 - metabolism; Complement Inactivator Proteins - pharmacology; Ischemia - pathology; Ischemia - physiopathology; Kidney - drug effects; Kidney - pathology; Kidney - physiopathology; Kidneys; Male; Medical sciences; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; Nephrology. Urinary tract diseases; Receptors, Complement 3b - deficiency; Receptors, Complement 3d - deficiency; Renal Circulation; Reperfusion Injury - pathology; Reperfusion Injury - physiopathology; Staining and Labeling; Urinary system involvement in other diseases. Miscellaneous; Kidney disease; Animal model; Urinary system disease; Pathogenesis; Complement C3; Rodentia; Cell adhesion molecule; Cardiovascular disease; Kidney; Vertebrata; Mammalia; Reperfusion; Ischemia; Mouse; Cell death; Animal; Inhibition; Apoptosis
• ISSN: 1046-6673; 1533-3450
• DOI: 10.1681/ASN.V1271383

The complex pathogenesis of ischemia reperfusion injury (IRI) includes endothelial expression of adhesion molecules, leukocyte recruitment and activation, reactive oxygen species production, and apoptotic and necrotic cell death. A role for complement in IRI of different organs, including kidney, has been proposed on the basis of results of experiments that used pharmacologic inhibitors as well as animals that were deficient in individual complement proteins. Here, renal IRI in mice was examined. Animals that were deficient in C3 had partial protection from IRI induced by 27.5 min of bilateral renal ischemia, followed by 20 h of reperfusion (blood urea nitrogen [BUN] values, 46.6 +/- 6.9 and 68.4 +/- 7.9 mg/dl in C3 -/- and C3 +/+ mice; n = 7 and 8, respectively; P = 0.033). Given the reduction in IRI in C3 -/- mice, it was investigated, by use of the rodent C3 convertase inhibitor CR1-related gene/protein y-Ig (Crry-Ig), whether exogenous administration of a complement inhibitor could lessen renal injury. Despite the use of Crry-Ig in high doses, there was no significant reduction of injury induced by 20 to 30 min of ischemia followed by up to 30 h of reperfusion. Histologic examination revealed acute tubular necrosis and neutrophilic infiltration, both of which correlated significantly with BUN values (P < 0.001). Of interest, C3 deposition around renal tubules was significantly less in animals with IRI, compared with that in unmanipulated controls (P < 0.001). In Crry-Ig-treated animals, C3 deposition was inversely proportional to BUN values (r = -0.63; P < 0.001), which presumably indicates that severe vascular IRI allowed access of the 160 kD Crry-Ig to the interstitium. Thus, renal IRI in mice may have a partial complement dependence, yet pharmacologic inhibition of the complement system does not seem to be effective, likely because of the presence of other mediator systems that operate in parallel.