Targeting CCL5 Attenuates Fibrosis via Activation of PI3k/Akt Signaling Axis After Glaucoma Filtration Surgery

Abstract

Purpose: Glaucoma filtration surgery (GFS) stands as a paramount clinical intervention for glaucoma. Nonetheless, the prevalent cause of GFS failure is filtration bleb scarring, and the role of inflammation and immune response in contributing to fibrosis remains elusive.

Methods: The study employed 30 female Sprague-Dawley rats (8 weeks old, 200-250 g) to assess the anti-scarring impact of the Chemokine (C-C motif) receptor 5 (CCR5)-Chemokine (C-C motif) ligand 5 (CCL5) antibody after GFS. Additionally, anti-fibrotic effects on HConFs were examined, creating an intra-operative inflammatory response using damaged-HConFs supernatant medium (DHSM). In vitro and in vivo validation aimed to elucidate the potential anti-fibrotic molecular mechanism of the CCR5-CCL5 antibody.

Results: The CCR5-CCL5 antibody effectively prolonged filtration bleb duration and enhanced the functionality of the filtered bleb. Improved postoperative intraocular pressure values (IOP) and morphological images were observed in the CCR5-CCL5 antibody-treated group. Histochemical staining and cellular experiments confirmed the antifibrotic function of the CCR5-CCL5 antibody. Notably, M2-type macrophage polarization was reduced in the CCR5-CCL5 antibody-treated model. CCL5-induced fibrosis in HConFs was mediated through the PI3K/Akt signaling pathway. Consistently, inhibition of PI3K/Akt significantly attenuated the profibrotic effects of CCR5-CCL5. Mechanistically, the CCL5 antibody exerts its antifibrotic effect by targeting CCR5 on HConFs, leading to the inhibition of the PI3K/Akt mechanism.

Conclusions: This study unveils that CCR5-CCL5 promotes fibrosis in GFS through inflammatory stimulation of HConFs and enhanced activation of the PI3K/Akt signaling pathway. The findings suggest that intraoperative CCR5-CCL5 antibody treatment could serve as a cost-effective therapeutic agent or a useful adjuvant in preventing ocular bleb scar formation.

Keywords: Chemokine (C-C motif) receptor 5/Chemokine (C-C motif) ligand 5 (CCR5/CCL5); Glaucoma filtration surgery (GFS); PI3K/Akt; fibrosis; macrophages.