Sulfated CXCR3 Peptide Trap Use as a Promising Therapeutic Approach for Age-Related Macular Degeneration

Background: and Objectives: Chemokines have various biological functions and potential roles in the development or progression of neuroinflammatory diseases. However, the specific pathogenic roles of chemokines in age-related macular degeneration (AMD), the leading cause of blindness in older individuals, remain elusive. Chemokines interact with their receptors expressed in the endothelium and on leukocytes. The sulfation of tyrosine residues in chemokine receptors increases the strength of ligand–receptor interaction and modulates signaling. Therefore, in the present study, we aimed to construct a human recombinant sulfated CXCR3 peptide trap (hCXCR3-S2) and mouse recombinant sulfated CXCR3 peptide trap (mCXCR3-S2) to demonstrate in vivo effects in preventing choroidal neovascularization and chemotaxis. Materials and Methods: First, the effect of hCXCR3-S was validated in vitro. Interestingly, hCXCR3-S2 inhibited the migration and invasion of two human cancer cell lines. Subsequently, the in vivo efficacy of mCXCR3-S2 was investigated using a mouse model of neovascular AMD. Results: Intravitreal injection of mCXCR3-S2 attenuated choroidal neovascularization and macrophage recruitment in neovascular lesions. These in vitro and in vivo effects were significantly stronger with CXCR3-S2 than with wild-type CXCR3 peptides. Conclusion: These findings demonstrate that the sulfated form of the CXCR3 peptide trap is a valuable tool that could be supplemented with antivascular endothelial growth factors in AMD treatment.