The Role Of Complement C3 In Chymase Promoting Renal Interstitial Fibrosis

Objective: To observe the role of complement C3 in chymase promoting renal interstitial fibrosis.Methods:1.The effect of C3 gene knockout on unilateral ureteral obstruction(UUO)mice.To establish UUO mouse model,and divide 12 wild type C57BL/6 mice into 2 groups: WTcontrol group and WTuuo group.12 C3 gene knockout(C3 gene knockout,C3KO)C57BL/6 mice were randomly divided into 2 groups: C3 KOcontrol group and C3 KO group.2.The effect of chymase inhibitor chymostatin on UUO mice.18 wild type C57BL/6 mice were randomly divided into 3 groups: WTcontrol group,WTuuo group,and WTuuo+chymostatin group.WTuuo+chymostatin group was intraperitoneally injected with 10mg/Kg chymostatin in the first to fourteenth day after operation.All mice were sacrificed at fourteenth days and ipsilateral renal tissue.Masson staining was used to observe the renal interstitial fibrosis,immunohistochemistry was used to observe and semi quantitative detection in C3 and mast cell tryptase(tryptase),AngII,TGF-beta 1,MMP9.Immunofluorescence was used to detect chymase's level,chymase activity of renal tissue was detected by kit.ELISA kit was used to detect AngII,C3 a,MMP9.Q-PCR was used to detect rennin mRNA changes.WB was used to detect chymase,rennin and TGF-beta 1.Results:1.Compared with WTcontrol group,obvious renal tubular injury(P<0.001)and renal interstitial fibrosis can be seen in WTuuo group(P<0.001),C3 and C3 a significantly increased(P<0.001),mast cells,chymase significantly increased(P<0.001),renin,AngII significantly increased(P<0.001),TGF-beta 1 was significantly increased(P<0.001),MMP9 significantly increased(P<0.01).Compared with the mice in C3 KO control group,C3 KOuuo group showed obvious renal tub?lar injury(P<0.001)and interstitial fibrosis(P<0.001),mast cells and chymase increased(P<0.001),renin and AngII significantly increased(P<0.001),and TGF-beta 1 increased significantly(P<0.01).Compared with WTuuo mice,C3 KOuuo micerenal tubule injury and renal interstitial fibrosis was significantly reduced(P< 0.001),mast cell infiltration and the release of chymase was significantly reduced(P<0.001),renin reduced(P<0.001),the level of AngII decreased(P<0.05),TGF-beta 1 and MMP9 both decreased significantly(P<0.05).2.Compared with WTcontrol group,WTuuo group had obvious renal tubular injury(P<0.001)and renal interstitial fibrosis(P<0.001),the activity of chymase increased significantly(P<0.001),AngII increased significantly(P<0.001),TGF-beta 1 was significantly increased(P<0.001),MMP9 increased significantly(P<0.01).Compared with WTuuo group,WTuuo+chymostatin group renal tubular injury significantly reduced(P<0.001),renal interstitial fibrosis was significantly reduced(P<0.001),chymase activity was significantly decreased(P<0.001),AngII reduced significantly(P<0.01),TGF-beta 1 significantly reduced(P<0.001),MMP9 reduced(P<0.05).Conclusion: C3/C3 a may promote renal interstitial fibrosis by participating in recruitment and activation of mast cells.Mast cells and C3/C3 a may interact with each other in renal interstitial fibrosis and form an amplification effect.