IL-17 signaling induces iNOS plus microglia activation in retinal vascular diseases

Activation of microglia and inflammation-mediated vascular damages are suggested to play a decisive role in the pathogenesis of various retinopathies. The inducible nitric oxide synthase (iNOS) was required for activated microglia-mediated injuries. However, the induction mechanism of microglia activation during retinal vascular diseases is still elusive. Here we showed that IL-17 induced microglia activation with high expression of iNOS and promoted the development of retinal vascular diseases. IL-17-dependent activation of the STAT3-iNOS pathway was essentially required for microglia activation, which promoted endothelial cell growth and accelerated vascular leakage and leukostasis via IL-6 in vitro and in vivo. Taken together, our data provide novel mechanistic insights on microglia activation-mediated retinopathy, unveil the specific role of IL-17 on microglia, and define novel therapeutic targets for treating retinal vascular diseases.

Automated summary

Inflammatory-mediated activation of microglia and iNOS play a crucial role in retinopathies, with IL-17 inducing microglia activation and promoting the development of retinal vascular diseases. Activation of the STAT3-iNOS pathway by IL-17 is essential for microglia activation, leading to endothelial cell growth and vascular leakage via IL-6.