concanavalin-a and Thrombosis

Despite the importance of endothelial injury and healing for primary and secondary renal disease and the availability of genetically engineered mouse models, to date no generally applicable murine disease model with site-specific renal endothelial injury has been established. We induced specific microvascular renal injury via selective renal arterial perfusion of the lectin concanavalin A (Con A) followed by sheep anti-concanavalin A and harvested tissues after 4 h, 24 h, days 3 and 7. Compared to control kidneys, histological evaluation demonstrated endothelial cell injury with subsequent complement, and platelet activation and thrombosis by light and electron microscopy. Mouse kidneys showed histologic evidence of severe glomerular and peritubular microvascular thrombosis with acute tubular necrosis, proteinuria, increased BUN and presence of schistocytes. Initial cell death of intrinsic renal cells resulted in a decrease of the glomerular cell count by 50% after 4 h followed by a proliferative response of glomerular (day 3, P < 0.05), interstitial (day 3, P < 0.05) and tubular cells leading to increased total glomerular cell count by day 7. This study establishes the Con A anti-Con A model as specific endothelial injury model in the mouse kidney providing a novel tool for investigating endothelial injury and repair mechanisms as well as elucidating the role of platelets in genetically engineered mice.

Topics: Animals; Apoptosis; Concanavalin A; Disease Models, Animal; Endothelium, Vascular; Immunohistochemistry; In Situ Nick-End Labeling; Kidney Glomerulus; Kidney Tubular Necrosis, Acute; Male; Mice; Mice, Inbred C57BL; Microcirculation; Microscopy, Electron; Mitogens; Platelet Endothelial Cell Adhesion Molecule-1; Proteinuria; Renal Circulation; Severity of Illness Index; Thrombosis; Vascular Endothelial Growth Factor A

We studied the role of the C5b-9 membrane attack complex in two models of inflammatory glomerulonephritis (GN) initiated by acute glomerular endothelial injury in Piebold-viral-Glaxo (PVG) complement-sufficient rats (C+), C6-deficient rats (C6-), and rats systematically depleted of complement with cobra venom factor (CVF). GN was induced by performing a left nephrectomy and selectively perfusing the right kidney with either 1) the lectin concanavalin A (Con A) followed by complement-fixing anti-Con A (Con A GN) or 2) purified complement-fixing goat anti-rat glomerular endothelial cell (GEN) antibody [immune-mediated thrombotic microangiopathy (ITM)]. Comparable levels of GEN apoptosis were detected in C+ animals in both models. CVF administration reduced GEN apoptosis by 10- to 12-fold. GEN apoptosis was C5b-9 dependent because PVG C6- rats were protected from GEN loss. Furthermore, functional inhibition of the cell surface complement regulatory protein CD59 by renal perfusion with anti-CD59 antibody in ITM resulted in a 3.5-fold increase in GEN apoptosis. Last, in Con A GN, abrogation of GEN apoptosis preserved endothelial integrity and renal function. This study demonstrates the specific role of C5b-9 in the induction of GEN apoptosis in experimental inflammatory GN, a finding with implications for diseases associated with the presence of antiendothelial cell antibodies.

Topics: Animals; Apoptosis; Complement C6; Complement Membrane Attack Complex; Concanavalin A; Disease Models, Animal; Endothelium; Glomerulonephritis; Kidney Glomerulus; Male; Rats; Thrombosis

Topics: Adult; Aprotinin; Aspirin; Blood Coagulation; Blood Platelets; Cell Survival; Concanavalin A; Dipyridamole; Female; Humans; Lymphocyte Activation; Lymphokines; Male; Phenylmethylsulfonyl Fluoride; Platelet Aggregation; Thrombosis; Tranexamic Acid

Topics: Cell Migration Inhibition; Concanavalin A; Fibrinolysis; Granulocytes; Humans; Leukocytes; Lymphocytes; Lymphokines; Thrombosis