Overexpression of EGFL7 promotes angiogenesis and nerve regeneration in peripheral nerve injury

Peripheral nerve injury (PNI) often leads to significant functional impairment. Here, we investigated the impact of epidermal growth factor-like domain-containing protein 7 (EGFL7) on angiogenesis and nerve regeneration following PNI. Using a sciatic nerve injury model, we assessed nerve function using the sciatic nerve function index. We analyzed the expression levels of EGFL7, forkhead box proteins A1 (FOXA1), nerve growth factor (NGF), brain-derived neurotrophic factors (BDNF), Neurofilament 200 (NF200), myelin protein zero (P0), cell adhesion molecule 1 (CD31), vascular endothelial growth factor (VEGF), and NOTCH-related proteins in tissues and cells. Cell proliferation, migration, and angiogenesis were evaluated through cell counting kit assays, 5-ethynyl-2'deoxyuridine staining, and Transwell assays. We investigated the binding of FOXA1 to the EGFL7 promoter using dual-luciferase assays and chromatin immunoprecipitation. We observed decreased EGFL7 expression and increased FOXA1 expression in PNI, and EGFL7 overexpression alleviated gastrocnemius muscle atrophy, increased muscle weight, and improved motor function. Additionally, EGFL7 overexpression enhanced Schwann cell and endothelial cell proliferation and migration, promoted tube formation, and upregulated NGF, BDNF, NF200, P0, CD31, and VEGF expression. FOXA1 was found to bind to the EGFL7 promoter region, inhibiting EGFL7 expression and activating the NOTCH signaling pathway. Notably, FOXA1 overexpression counteracted the effects of EGFL7 on Schwann cells and endothelial cells. In conclusion, EGFL7 holds promise as a therapeutic molecule for treating sciatic nerve injury.