Lycium barbarum glycopeptide reduces inflammation and fibrosis in corneal injury by modulating the NF-κB/NLRP3/IL-1 β signaling pathway and microRNA-21a-5p/SMAD7

Abstract

Lycium barbarum glycopeptide (LbGp), derived from the Chinese medicinal plant Lycium barbarum, has demonstrated anti-inflammatory properties; however, its precise role and mechanism in corneal repair following injury remain elusive. The present research investigated the mechanisms and effects of LbGp on corneal repair following alkali burn injury using in vivo mouse models of corneal alkali burn and in vitro human keratocyte fibrosis models. Corneal inflammation, opacity, and epithelial defects were assessed via a slit lamp microscope. Results showed that LbGp-treated mice exhibited reduced edema, accelerated re-epithelialization, and decreased corneal opacity compared to the phosphate-buffered saline (PBS)-treated controls. Proteomic analysis revealed altered proteins enriched in the extracellular matrix among the control, injury, and LbGp treatment groups. Moreover, LbGp significantly attenuated TGFβ-1-induced myofibroblasts transdifferentiation from keratocytes. Consistently, LbGp treatment inhibited the upregulation of fibrosis markers (αSMA, fibronectin, and collagen III) at both the protein and mRNA levels after corneal alkali burns. LbGp also effectively suppressed the activation of the NF-κB/NLRP3/IL-1β signaling pathway and neutrophil infiltration following corneal alkali burn injury. Additionally, miR-21 was upregulated in TGFβ-1-stimulated keratocytes and in the alkali-burned mouse cornea. LbGp decreased miR-21 expression, while increasing expression of its target, Smad7, thereby dampening the TGFβ/Smad2/3 signaling pathway. This research demonstrates that LbGp promotes corneal healing by inhibiting inflammation and fibrosis after alkali burns, suggesting its potential as a supplementary therapy for corneal injury repair.