Suppression of choroidal neovascularization by thioredoxin-1 via interaction with complement factor H.
OBJECTIVE
To examine the role of thioredoxin-1 (TRX-1), an endogenous protein with a variety of redox-related roles, in the formation of choroidal neovascularization (CNV).


METHODS
CNV was induced by laser photocoagulation of the ocular fundus in wild-type and transgenic mice overexpressing human TRX-1 (TRX-1 Tg). Mice were injected intraperitoneally with TRX-1, mutant TRX, or vehicle. The incidence of CNV was evaluated by lectin staining. Leukocyte recruitment and C3b deposition after laser injury were determined by immunohistochemistry and Western blotting. Moreover, TRX-1-associated proteins from human plasma were isolated by two-dimensional gel electrophoresis with the use of a column coupled with a mutant TRX-1 and were identified by mass spectrometry and proteomics analysis. Complement activation was determined by a fluid-phase


METHODS



RESULTS
The incidence of laser-induced CNV was reduced in TRX-1 Tg mice (56.1%) and in C57B/6 mice treated with TRX-1 (46.7%) but not in mutant TRX-1 (79.2%) compared with wild-type mice (85.7%). Furthermore, leukocyte recruitment was prevented in TRX-1-treated mice; C3b deposition was decreased in these and TRX-1 Tg mice. In human plasma, five proteins associated with TRX-1 were identified as apolipoprotein A-I, the CD5 antigen-like member of the scavenger receptor, cysteine-rich superfamily fibrinogen, albumin, and complement factor H (CFH). TRX-1 inhibited the alternative pathway C3 convertase, and its effect was additive with CFH.


CONCLUSIONS
These findings show that TRX-1 interacts with CFH, regulates complement activity, and inhibits CNV, suggesting novel preventive and interventional therapeutic strategies for AMD.
Department of Ophthalmology and Visual Science, Kumamoto University Graduate School of Medical Sciences, Kumamoto, Japan.
Yasuya
Y
Inomata
Hidenobu
H
Tanihara
Masaki
M
Tanito
Hiroaki
H
Okuyama
Yuma
Y
Hoshino
Tomoya
T
Kinumi
Takahiro
T
Kawaji
Norihiko
N
Kondo
Junji
J
Yodoi
Hajime
H
Nakamura
D000818:Animals; D015153:Blotting, Western; D020256:Choroidal Neovascularization / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D017242:Complement Factor H / Q000187:drug effects / Q000378:metabolism*; D004195:Disease Models, Animal; D015180:Electrophoresis, Gel, Two-Dimensional; D006801:Humans; D007150:Immunohistochemistry; D007274:Injections, Intraperitoneal; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D013879:Thioredoxins / Q000008:administration & dosage / Q000627:therapeutic use*
D013879:Thioredoxins; D017242:Complement Factor H