title: Interleukin-35 attenuates collagen-induced arthritis through suppression of vascular endothelial growth factor and its receptors.
abstract: OBJECTIVE
  To investigate the effect of interleukin-35 (IL-35) on vascular endothelial growth factor (VEGF) and its receptors, Flt-1 and Flk-1, in a collagen-induced arthritis (CIA) mouse model of rheumatoid arthritis (RA).
  
  
  METHODS
  We established a CIA mouse model and injected IL-35 intraperitoneally. The articular index (AI) was measured based on the amount of erythema, swelling, or joint rigidity and synovial histology was measured by hematoxylin and eosin staining (HE staining). The levels of VEGF, Flt-1, Flk-1, and von Willebrand factor (vWF) expression in CIA synovial tissue were determined by immunohistochemistry. The mRNA and protein expression levels of VEGF, Flt-1, Flk-1, TNF-α, and INF-γ were detected by reverse transcription PCR (RT-PCR) and western blots, respectively.
  
  
  RESULTS
  The IL-35 treatment decreased the AI and the synovial histological scores of CIA mice. Immunohistochemistry results revealed that the IL-35 treatment downregulated VEGF, Flt-1, Flk-1, and vWF expression in the CIA mice. RT-PCR results showed that the IL-35-treated mice had lower levels of VEGF, Flt-1, Flk-1, and TNF-α mRNA expression than those of the PBS-treated mice. While there was no significant difference in the level of INF-γ mRNA expression between IL-35-treated and PBS-treated mice. Western blot results showed that the IL-35 treatment downregulated the levels of VEGF, Flt-1, Flk-1, and TNF-α in CIA mice, but the level of INF-γ was not significantly affected.
  
  
  CONCLUSIONS
  These findings show that IL-35 may represent a novel therapeutic agent for RA, and the probable mechanisms may rely on inhibiting VEGF and its receptors Flt-1 and Flk-1.
authors.affiliation: Department of Rheumatology and Immunology, the First Affiliated Hospital of China Medical University, 155 Nanjing North Street, Heping District, Shenyang 110001, PR China; Department of Immunology and Microbiology, Liaoning, Vocational College of Medicine, No. 2 Qiaosong Road, Shenyang 110101, PR China.
authors.forename: Suqin
authors.initials: S
authors.lastname: Wu
authors.affiliation: Department of Rheumatology and Immunology, the First Affiliated Hospital of China Medical University, 155 Nanjing North Street, Heping District, Shenyang 110001, PR China.
authors.forename: Yunxia
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Rheumatology and Immunology, the First Affiliated Hospital of China Medical University, 155 Nanjing North Street, Heping District, Shenyang 110001, PR China.
authors.forename: Yuxuan
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Sports Medicine and Joint Surgery/Orthopedic, The First Affiliated Hospital of China Medical University, 155 Nanjing North Street, Heping District, Shenyang 110001, PR China.
authors.forename: Lutian
authors.initials: L
authors.lastname: Yao
authors.affiliation: Department of Rheumatology and Immunology, the First Affiliated Hospital of China Medical University, 155 Nanjing North Street, Heping District, Shenyang 110001, PR China.
authors.forename: Tiantian
authors.initials: T
authors.lastname: Lin
authors.affiliation: Department of Rheumatology and Immunology, the First Affiliated Hospital of China Medical University, 155 Nanjing North Street, Heping District, Shenyang 110001, PR China.
authors.forename: Shenyi
authors.initials: S
authors.lastname: Jiang
authors.affiliation: Department of Rheumatology and Immunology, the First Affiliated Hospital of China Medical University, 155 Nanjing North Street, Heping District, Shenyang 110001, PR China.
authors.forename: Hui
authors.initials: H
authors.lastname: Shen
authors.affiliation: Department of Rheumatology and Immunology, the First Affiliated Hospital of China Medical University, 155 Nanjing North Street, Heping District, Shenyang 110001, PR China.
authors.forename: Liping
authors.initials: L
authors.lastname: Xia
authors.affiliation: Department of Rheumatology and Immunology, the First Affiliated Hospital of China Medical University, 155 Nanjing North Street, Heping District, Shenyang 110001, PR China. Electronic address: lujingtan@163.com.
authors.forename: Jing
authors.initials: J
authors.lastname: Lu
mesh_terms: D000818:Animals; D001169:Arthritis, Experimental / Q000276:immunology*; D001172:Arthritis, Rheumatoid / Q000276:immunology*; D004195:Disease Models, Animal; D005786:Gene Expression Regulation / Q000276:immunology; D006801:Humans; D007378:Interleukins / Q000502:physiology*; D008297:Male; D051379:Mice; D008811:Mice, Inbred DBA; D009389:Neovascularization, Pathologic / Q000276:immunology; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism*; D040281:Vascular Endothelial Growth Factor Receptor-1 / Q000235:genetics / Q000378:metabolism*; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000235:genetics / Q000378:metabolism; D014841:von Willebrand Factor
chemical_list: D007378:Interleukins; D042461:Vascular Endothelial Growth Factor A; C029417:Von Willebrand antigen; C569375:interleukin-35, mouse; C467480:vascular endothelial growth factor A, mouse; D014841:von Willebrand Factor; C501163:Flt1 protein, mouse; D040281:Vascular Endothelial Growth Factor Receptor-1; D040301:Vascular Endothelial Growth Factor Receptor-2
keywords: Collagen-induced arthritis; Interleukin-35; Rheumatoid arthritis; Vascular endothelial growth factor