Effect of Interleukin-34 on Secretion of Angiogenesis Cytokines by Peripheral Blood Mononuclear Cells of Rheumatoid Arthritis

ABSTRACT

Background: Interleukin (IL)-34 is a new pro-inflammatory cytokine. Previous studies showed that IL-34 plays a key role in inflammation and osteoporosis in rheumatoid arthritis (RA). However, whether IL-34 participates in angiogenesis in RA remains unknown. Vascular endothelial growth factor (VEGF) and hypoxia-inducible factor-1α (HIF-1α) play critical roles in the angiogenesis of RA. Methods: 22 patients with RA, 18 patients with ankylosing spondylitis (AS), and 8 healthy subjects were enrolled in this study. Peripheral blood mononuclear cells (PBMCs) were isolated and purified from peripheral blood by density gradient centrifugation. PBMCs were stimulated using anti-CD3/CD28 antibody and different concentrations of recombinant human (rh) IL-34 (0, 10, 20, 50, 100 ng/mL). Cell-free supernatants were collected after 72 h incubation, and VEGF and HIF-1α levels were determined by enzyme-linked immunosorbent assay (ELISA). Results: IL-34 promotes the secretion of VEGF and HIF-1α by PBMCs in RA patients in a dose-dependent manner. In contrast, IL-34 has no effect on VEGF and HIF-1α secretion by PBMCs in AS and healthy controls. Conclusion: IL-34 may indirectly contribute to angiogenesis by promoting the production of VEGF and HIF-1α and participate in the pathogenesis of RA.

KEYWORDS:

• Rheumatoid arthritis
• interleukin-34
• vascular endothelial growth factor
• hypoxia-inducible factor-1α
• angiogenesis

Acknowledgments

This work was supported by the National Natural Science Foundation of China under Grant No.81373219.

Disclosure Statement

The authors declare no competing interests.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [No. 81373219].