Inhibiting PRMT1 protects against CoNV by regulating macrophages through the FGF2/PI3K/Akt pathway

Abstract

Corneal neovascularization (CoNV) is predominantly initiated by inflammatory processes, resulting in aberrant vascular proliferation and consequent visual impairment. Existing therapeutic interventions for CoNV demonstrate limited efficacy and potential for adverse reactions. Protein arginine methyltransferase 1 (PRMT1) is associated with the regulation of inflammation and M2 macrophage polarization. Nevertheless, the precise mechanism by which PRMT1 operates in CoNV remains uncertain. This study explored the impact of PRMT1 inhibition in a murine model of CoNV induced by alkali burn. Our findings indicated a direct relationship between PRMT1 levels and corneal damage. Moreover, our observations indicated an increase in fibroblast growth factor 2 (FGF2) expression in CoNV, which was reduced after treatment with a PRMT1 inhibitor. The inhibition of PRMT1 alleviated both corneal injury and CoNV, as evidenced by decreased corneal opacity and neovascularization. Immunofluorescence analysis and evaluation of inflammatory factor expression demonstrated that PRMT1 inhibition attenuated M2 macrophage polarization, a phenomenon that was reversed by the administration of recombinant FGF2 protein. These results were confirmed through experimentation on Human Umbilical Vein Endothelial Cells (HUVECs) and Mouse leukemia cells of monocyte macrophage cells (RAW264.7). Furthermore, it was established that FGF2 played a role in PI3K/Akt signal transduction, a critical regulatory pathway for M2 macrophage polarization. Importantly, the activity of this pathway was found to be suppressed by PRMT1 inhibitors. Mechanistically, PRMT1 was shown to promote M2 macrophage polarization, thereby contributing to CoNV, through the FGF2/PI3K/Akt pathway. Therefore, targeting PRMT1 may offer a promising therapeutic approach.