Complement C5 mediates experimental tubulointerstitial fibrosis.
Renal fibrosis is the final common pathway of most progressive renal diseases. C5 was recently identified as a risk factor for liver fibrosis. This study investigated the role of C5 in the development of renal tubulointerstitial fibrosis by (1) induction of renal fibrosis in wild-type and C5(-/-) mice by unilateral ureteral ligation (UUO) and (2) investigation of the effects of a C5a receptor antagonist (C5aRA) in UUO. In C5(-/-) mice, when compared with wild-type controls, markers of renal fibrosis (Sirius Red, type I collagen, fibronectin, alpha-smooth muscle actin, vimentin, and infiltrating macrophages) were significantly reduced on day 5 of UUO. On day 10, fibronectin mRNA and protein expression were still reduced in the C5(-/-) mice. Cortical mRNA of all PDGF isoforms and of TGF-beta(1) (i.e., central mediators of renal disease) were significantly reduced in C5(-/-) mice when compared with controls. Renal tubular cell expression of the C5aR was sparse in normal cortex but markedly upregulated after UUO. Treatment of wild-type UUO mice with C5aRA also led to a significant reduction of cortical Sirius Red staining, fibronectin protein expression, and PDGF-B mRNA expression on day 5. Neither genetic C5 deficiency nor C5aRA treatment caused any histologic changes in the nonobstructed kidneys. In cultured murine cortical tubular cells, C5a stimulated production of TGF-beta(1), and this was inhibited by C5aRA. Using a combined genetic and pharmacologic approach, C5, in particular C5a, is identified as a novel profibrotic factor in renal disease and as a potential new therapeutic target.
Boor
Peter
P
Division of Nephrology, Rheinische-Westfälische Technische Hochschule, University of Aachen, Aachen, Germany.
Konieczny
Andrzej
A
Villa
Luigi
L
Schult
Anna-Lisa
AL
Bücher
Eva
E
Rong
Song
S
Kunter
Uta
U
van Roeyen
Claudia R C
CR
Polakowski
Thomas
T
Hawlisch
Heiko
H
Hillebrandt
Sonja
S
Lammert
Frank
F
Eitner
Frank
F
Floege
Jürgen
J
Ostendorf
Tammo
T
D000818:Animals; D002478:Cells, Cultured; D003182:Complement C5 / Q000235:genetics*; D015936:Complement C5a / Q000235:genetics / Q000378:metabolism; D004195:Disease Models, Animal; D005355:Fibrosis; D005786:Gene Expression Regulation; D006801:Humans; D007668:Kidney / Q000473:pathology*; D007674:Kidney Diseases / Q000188:drug therapy / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D008264:Macrophages / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010982:Platelet-Derived Growth Factor / Q000235:genetics / Q000378:metabolism; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D011951:Receptors, Complement / Q000627:therapeutic use; D053773:Transforming Growth Factor beta1 / Q000235:genetics / Q000378:metabolism; D014517:Ureteral Obstruction / Q000188:drug therapy / Q000235:genetics / Q000473:pathology; D014945:Wound Healing / Q000187:drug effects
D003182:Complement C5; D010982:Platelet-Derived Growth Factor; D020033:Protein Isoforms; D011951:Receptors, Complement; D053773:Transforming Growth Factor beta1; D015936:Complement C5a