Study on the Role of Short Peptide LCKLSL Targeting ANXA2 in Retinal Neovascularization.

Abstract

BACKGROUND/AIM: Annexin A2 (ANXA2), functioning as a co-receptor for tissue plasminogen activator (tPA) and plasminogen, plays a critical role in retinal neovascularization (RNV). The hexapeptide LCKLSL competitively inhibits ANXA2 activity, offering a potential therapeutic strategy for RNV in retinopathy of prematurity (ROP). This study investigated the efficacy and biosafety of LCKLSL in suppressing RNV using an oxygen-induced retinopathy (OIR) model in C57BL/6J mice. MATERIALS AND METHODS: LCKLSL was administeredintravitreal injection, with RNV inhibition evaluated through retinal immunofluorescence and hematoxylin-eosin (HE) staining. Comprehensive safety assessments encompassing short- and long-term evaluations were performed using retinal thickness measurements, electroretinography (ERG), and histological analyses of hepatic/renal tissues. Immunohistochemistry confirmed ANXA2-RNV colocalization and LCKLSL targeting specificity. Molecular mechanisms were analyzed using enzyme-linked immunosorbent assay (ELISA) to quantify cell-surface tPA binding in human retinal microvascular endothelial cells (HRMECs), while qRT-PCR and western blot were employed to detect RNV-related factors. Complementaryexperiments using hypoxia-induced human umbilical vein endothelial cells (HUVECs) assessed cellular safety (CCK-8 and TUNEL assays) and therapeutic effects on migration (Wound healing assay), angiogenesis (Matrigel tube formation), and invasion (Transwell assay). RESULTS: LCKLSL significantly attenuated RNV formation without inducing pathological alterations in retinal structure or systemic toxicity. Mechanistically, LCKLSL reduced cell-surface tPA binding and suppressed vascular endothelial growth factor (VEGF) and metalloproteinase (MMP) expression at mRNA and protein levels., LCKLSL inhibited HUVEC migration, tube formation, and invasion under hypoxia. CONCLUSION: LCKLSL acts as a potent ANXA2-targeted inhibitor of pathological angiogenesis and demonstrates a favorable biosafety profile, highlighting its promising therapeutic potential for the treatment of RNV-related disorder.