MMP12 Inhibits Corneal Neovascularization and Inflammation through Regulation of CCL2

Area of Science:

• Ophthalmology
• Immunology
• Wound Healing

Background:

• Corneal injury triggers cellular and protein interactions to restore homeostasis.
• Chronic inflammation, neovascularization, and fibrosis can arise if this response is unregulated.
• Chemokine (C-C motif) ligand 2 (CCL2) and its receptor CCR2 are critical regulators of inflammatory and neovascular responses.

Purpose of the Study:

• To investigate the role of macrophage-associated matrix metalloproteinase 12 (MMP12) in regulating CCL2 and CCR2 expression following corneal injury.
• To elucidate the mechanism by which MMP12 influences corneal wound healing and inflammatory responses.

Main Methods:

• Utilized two distinct corneal injury models in Mmp12 knockout (Mmp12^-/-) and wild-type (WT) mice.
• Examined the temporal and spatial expression patterns of CCL2 and CCR2 in both genotypes.
• Assessed the impact of CCL2 blockade on macrophage infiltration and neovascularization in Mmp12^-/- and WT corneas.

Main Results:

• MMP12 was found to downregulate CCL2 and CCR2 expression in a manner dependent on injury timing and mechanism.
• Macrophage infiltration and corneal neovascularization were significantly reduced in Mmp12^-/- corneas compared to WT corneas after CCL2 blockade.
• MMP12 plays a crucial role in modulating the inflammatory and neovascular cascades post-corneal injury.

Conclusions:

• MMP12 inhibits corneal inflammation and neovascularization after injury by regulating CCL2 and CCR2.
• Targeting MMP12 may offer a therapeutic strategy for managing complications following corneal injury, such as chronic inflammation and excessive neovascularization.