MYDGF promotes pathological and physiological retinal angiogenesis via the Gαi1/3-Gab1-Akt-mTOR signaling.

Retinal neovascularization (RNV) is a potential vision-threatening process characterized by the abnormal growth of retinal vessels. Despite its clinical prevalence, the precise mechanisms governing RNV initiation and progression remain incompletely defined. Here we identify myeloid-derived growth factor (MYDGF) as a critical regulator of retinal vascular dynamics. Using single-cell RNA sequencing and human patient validation, we show that MYDGF is upregulated in retinal endothelial cells during proliferative diabetic retinopathy and mouse models of pathological neovascularization. In vitro, MYDGF promotes retinal endothelial cell proliferation, migration, and sprouting. In vivo, endothelial-specific MYDGF depletion inhibits both normal vascular development and pathological neovascularization in neonatal mice, and disrupting adult vascular homeostasis in male mice. MYDGF drives angiogenesis by activating the Akt-mTOR cascade through the Gαi1/3-Gab1 signaling complex; genetic depleting or mutation these components suppress MYDGF-induced Akt-mTOR activation and angiogenic responses. Together, MYDGF promotes retinal angiogenesis and maintains vascular homeostasis via the Gαi1/3-Gab1-Akt-mTOR signaling axis.