Chrysin alleviates DNA damage to improve disturbed immune homeostasis and pro-angiogenic environment in laser-induced choroidal neovascularization

Choroidal neovascularization (CNV) is a devastating pathology of numerous ocular diseases, such as wet age-related macular degeneration (wAMD), which causes irreversible vision loss. Although anti-vascular endothelial growth factor (VEGF) therapy has been widely used, poor response or no response still exists in some cases, suggesting that there are other components involved in the angiogenic process. Therefore, the underlying mechanism needs to be clarified and new target of anti-angiogenic therapy is urgently needed. It has been demonstrated that damaged retinal pigment epithelium (RPE) cells can activate inflammasome, driving a degenerative tissue environment and an enhanced pro-angiogenic response, which implies that RPE dysfunction may be a hallmark of the pathogenesis. Previously, we have shown that DNA damage can induce RPE dysfunction, triggering senescence-associated secretory phenotype (SASP) and local inflammation. In this study, we identify that chrysin can reduce DNA damage, especially telomere erosion in vitro, thus compromise the dysfunction of RPE and the decreased expression of SASP factor. Importantly, we find that DNA damage of RPE cells is remarkable in laser-induced CNV lesion, resulting in inflammatory response, which can be ameliorated by chrysin, mainly through IL-17 signaling pathway and its downstream signal transducer and activator of transcription 3 (STAT3) activities. In summary, our results indicate the interplay between DNA damage, perturbed RPE homeostasis, inflammatory response and angiogenesis in laser-induced CNV, and more importantly, chrysin may be an effective therapeutic supplement for CNV.