Inhibition of angiogenesis by interleukin-4 gene therapy in rat adjuvant-induced arthritis.
OBJECTIVE
Interleukin-4 (IL-4) can modulate neovascularization. In this study, we used a gene therapy approach to investigate the role of IL-4 in angiogenesis in rat adjuvant-induced arthritis (AIA), a model for rheumatoid arthritis.


METHODS
Rats received an adenovirus producing IL-4 (AxCAIL-4), a control virus without insert, or control vehicle (phosphate buffered saline) intraarticularly before arthritis onset. At peak onset of arthritis, rats were killed. Vascularization was determined in the synovial tissue, and correlations with inflammation were assessed. Ankle homogenates were used in angiogenesis assays in vitro and in vivo, and protein levels of cytokines and growth factors were assessed by enzyme-linked immunosorbent assay. Synovial tissue expression of alphav integrins was determined by immunohistochemistry.


RESULTS
IL-4 induced a reduction in synovial tissue vessel density, which was paralleled by a decrease in inflammation. AxCAIL-4 joint homogenates significantly (P < 0.05) inhibited both endothelial cell (EC) migration and tube formation in vitro. Similarly, AxCAIL-4 inhibited capillary sprouting in the rat aortic ring assay, and vessel growth in the in vivo Matrigel plug assay. The angiostatic effect occurred despite high levels of vascular endothelial growth factor (VEGF), and was associated with down-regulation of the proangiogenic cytokines IL-18, CXCL16, and CXCL5 and up-regulation of the angiogenesis inhibitor endostatin. Of interest, AxCAIL-4 also resulted in decreased EC expression of the alphav and beta3 integrin chains.


CONCLUSIONS
In rat AIA, IL-4 reduces synovial tissue vascularization via angiostatic effects, mediates inhibition of angiogenesis via an association with altered pro- and antiangiogenic cytokines, and may inhibit VEGF-mediated angiogenesis and exert its angiostatic role in part via alphavbeta3 integrin. This knowledge of the specific angiostatic effects of IL-4 may help optimize target-oriented treatment of inflammatory arthritis.
Haas
Christian S
CS
University of Michigan Medical School, Ann Arbor, MI 48109-0680, USA.
Amin
M Asif
MA
Allen
Brittany B
BB
Ruth
Jeffrey H
JH
Haines
G Kenneth
GK
Woods
James M
JM
Koch
Alisa E
AE
D000276:Adjuvants, Immunologic / Q000235:genetics* / Q000378:metabolism; D020533:Angiogenesis Inhibitors / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D001011:Aorta / Q000187:drug effects; D001169:Arthritis, Experimental / Q000235:genetics / Q000628:therapy*; D002465:Cell Movement / Q000187:drug effects; D002478:Cells, Cultured; D005260:Female; D015316:Genetic Therapy; D006614:Hindlimb / Q000737:chemistry; D039302:Integrin alphaVbeta3 / Q000378:metabolism; D015847:Interleukin-4 / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D009389:Neovascularization, Pathologic / Q000473:pathology / Q000503:physiopathology / Q000517:prevention & control*; D051381:Rats; D011917:Rats, Inbred Lew; D017207:Rats, Sprague-Dawley; D013583:Synovial Membrane / Q000098:blood supply / Q000378:metabolism / Q000473:pathology; D014020:Tissue Extracts / Q000494:pharmacology
D000276:Adjuvants, Immunologic; D020533:Angiogenesis Inhibitors; D039302:Integrin alphaVbeta3; D014020:Tissue Extracts; D015847:Interleukin-4