Interleukin 29 is a novel antiangiogenic factor in angiogenesis

Angiogenesis is tightly controlled by growth factors and cytokines in pathophysiological settings. Despite the importance of Interleukin 29 (IL-29), a newly identified cytokine of type III interferon family, its role in angiogenesis remains unknown. We aimed to elucidate IL-29's impact on angiogenesis under both and physiological and pathological conditions.

We employed various assays to evaluate IL-29's effect on proliferation, apoptosis, migration and tube formation of human umbilical vein endothelial cells (HUVEC) in vitro. IL-29's angiogenic effect was assessed using mouse aortic rings ex vivo, and oxygen-induced retinopathy (OIR) mouse model in vivo. Signaling pathways possibly involved in IL-29-induced angiogenesis were investigated by Western blot. Finally, IL-29's impact on tube formation was blocked by inhibiting IL-29/interleukin 10 receptor 2 (IL-10R2) binding.

IL-29 treatment inhibited endothelial cell migration, tube formation and vessel sprouting, without affecting proliferation or apoptosis. Notably, IL-29 (100 ng/ml) attenuated vessel growth in pathological angiogenesis in OIR mice, accompanied by decreased expression of vascular endothelial growth factor (VEGF) and hypoxia inducible factor-1α (HIF-1α). Mechanistically, IL-29 activated Stat3 signaling pathway, and blocking IL-29/IL-10R2 binding remarkably reversed IL-29's anti-angiogenic effect on tube formation.

Our findings demonstrated that IL-29, at a relative low concentration, modulates angiogenesis in both physiological and pathological contexts. Targeting IL-29 or its receptor IL-10R2 offers a promising strategy for angiogenesis regulation in various conditions.