Interleukin-35 attenuates collagen-induced arthritis through suppression of vascular endothelial growth factor and its receptors

Int Immunopharmacol. 2016 May:34:71-77. doi: 10.1016/j.intimp.2016.02.018. Epub 2016 Feb 26.

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.

Conclusion: 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.

Keywords: Collagen-induced arthritis; Interleukin-35; Rheumatoid arthritis; Vascular endothelial growth factor.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Arthritis, Experimental / immunology*
  • Arthritis, Rheumatoid / immunology*
  • Disease Models, Animal
  • Gene Expression Regulation / immunology
  • Humans
  • Interleukins / physiology*
  • Male
  • Mice
  • Mice, Inbred DBA
  • Neovascularization, Pathologic / immunology
  • Vascular Endothelial Growth Factor A / genetics
  • Vascular Endothelial Growth Factor A / metabolism*
  • Vascular Endothelial Growth Factor Receptor-1 / genetics
  • Vascular Endothelial Growth Factor Receptor-1 / metabolism*
  • Vascular Endothelial Growth Factor Receptor-2 / genetics
  • Vascular Endothelial Growth Factor Receptor-2 / metabolism
  • von Willebrand Factor

Substances

  • Interleukins
  • Vascular Endothelial Growth Factor A
  • Von Willebrand antigen
  • interleukin-35, mouse
  • vascular endothelial growth factor A, mouse
  • von Willebrand Factor
  • Flt1 protein, mouse
  • Vascular Endothelial Growth Factor Receptor-1
  • Vascular Endothelial Growth Factor Receptor-2