Matrix metalloproteinase-9 and vascular endothelial growth factor expression change in experimental retinal...

Area of Science:

• Ophthalmology
• Molecular Biology
• Pathology

Background:

• Retinal neovascularization (RNV) is a hallmark of several blinding conditions, including retinopathy of prematurity (ROP).
• Matrix metalloproteinase-9 (MMP-9) and vascular endothelial growth factor (VEGF) are implicated in RNV pathogenesis.
• The precise signaling pathway linking MMP-9 to VEGF and subsequent RNV in oxygen-induced retinopathy (OIR) requires elucidation.

Purpose of the Study:

• To investigate the signal transduction mechanism of MMP-9-mediated VEGF expression in an OIR model.
• To determine the role of MMP-9 and VEGF in promoting retinal neovascularization (RNV) in OIR.
• To evaluate the therapeutic potential of tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) in mitigating OIR-induced changes.

Main Methods:

• An oxygen-induced retinopathy (OIR) model was established in C57BL/6J mice.
• Mice were divided into control, OIR, OIR with vehicle injection, and OIR with TIMP-1 injection groups.
• mRNA and protein levels of MMP-9, TIMP-1, and VEGF were quantified using real-time PCR and Western blotting; localization was assessed via immunohistochemistry.

Main Results:

• OIR significantly increased retinal MMP-9 and VEGF levels while decreasing TIMP-1 levels.
• A significant positive correlation was observed between MMP-9 and VEGF expression.
• Intravitreal injection of TIMP-1 significantly reduced both MMP-9 and VEGF expression in the OIR model (P<0.05).

Conclusions:

• MMP-9 upregulates VEGF, thereby promoting retinal neovascularization (RNV) in the context of retinopathy of prematurity (ROP).
• TIMP-1 effectively suppressed MMP-9 and VEGF, indicating its potential as a therapeutic agent for ROP.
• Targeting the MMP-9/VEGF pathway with TIMP-1 offers a promising strategy for preventing and treating ROP.