Prophylactic adenovirus-mediated human kallistatin gene therapy suppresses rat arthritis by inhibiting angiogenesis and inflammation.
OBJECTIVE
Kallistatin has been shown to be an angiogenesis inhibitor. In this study, we investigated whether adenovirus-mediated kallistatin gene delivery has a prophylactic effect in a rat arthritis model.


METHODS
Adenovirus containing the human kallistatin gene (AdHKBP) was injected intraarticularly into ankle joints before the onset of arthritis in a rat model. The effect of kallistatin gene transfer on endothelial cell proliferation in joint extracts was assayed. The response to kallistatin treatment was determined according to clinical parameters, including ankle circumference, articular index, and radiographic scores. Hematoxylin and eosin staining was performed in order to score joint tissues and count neutrophil numbers. In addition, small vessels were quantified by identification of von Willebrand factor-positive endothelial cells. The inflammatory responses were determined by measuring tumor necrosis factor alpha (TNFalpha) and interleukin-1beta (IL-1beta) levels in ankle homogenates.


RESULTS
The expression of recombinant human kallistatin in rat ankle joints after gene transfer was identified by immunohistochemical analysis and Western blotting. Significant reductions in the ankle circumference, articular index, and radiographic score were observed in AdHKBP-treated rats compared with control rats treated with the adenoviral plasmid carrying green fluorescent protein. Kallistatin gene transfer also significantly ameliorated the histologic scores in ankle joints and reduced vessel density and neutrophil numbers. The inhibitory effect of kallistatin on the accumulation of inflammatory cells in ankle joints was accompanied by reduced TNFalpha and IL-1beta levels in joint homogenates. Furthermore, an in vitro experiment showed that the proliferation of endothelial cells was markedly inhibited by the addition of AdHKBP-treated joint extract to the culture media, supporting a role of kallistatin in inhibiting angiogenesis.


CONCLUSIONS
This study demonstrates that kallistatin gene therapy has a prophylactic effect in inhibiting arthritis in the rat ankle. Kallistatin inhibits arthritis through its antiangiogenesis and antiinflammation activities. These results implicate potential therapeutic applications for suppression of arthritis by kallistatin gene therapy.
Wang
Chrong-Reen
CR
Department of Internal Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan. wangcr@mail.ncku.edu.tw
Chen
Shih-Yao
SY
Wu
Chao-Liang
CL
Liu
Ming-Fei
MF
Jin
Ying-Tai
YT
Chao
Lee
L
Chao
Julie
J
D000260:Adenoviruses, Human / Q000235:genetics* / Q000276:immunology; D000818:Animals; D001169:Arthritis, Experimental / Q000276:immunology / Q000473:pathology / Q000517:prevention & control*; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D004195:Disease Models, Animal; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods; D006801:Humans; D007596:Joints / Q000378:metabolism / Q000473:pathology; D007610:Kallikreins; D008297:Male; D009389:Neovascularization, Pathologic / Q000276:immunology / Q000473:pathology / Q000517:prevention & control*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015843:Serpins / Q000235:genetics* / Q000378:metabolism
D002352:Carrier Proteins; D015843:Serpins; C051324:kallistatin; D007610:Kallikreins