Chiglitazar Activates PPAR-α/γ to Suppress Oxidative Stress and Angiogenesis in Corneal Neovascularization

Chiglitazar (Chi) is a pan-peroxisome proliferator-activated receptor (PPAR) agonist with reported anti-oxidative effects in metabolic disorders. In this study, we investigate its therapeutic effects and potential mechanisms in corneal neovascularization (CNV).

Scratch-wound and tube formation assays in human umbilical vein endothelial cells (HUVECs) were performed to evaluate the effects of Chi under recombinant human vascular endothelial growth factor (VEGF) stimulation. An oxidative stress model was established in human corneal epithelial cells (HCEs), and intracellular reactive oxygen species (ROS) levels were quantified by flow cytometry. A corneal alkali burn mouse model of CNV was established. Chi was then administered and compared with vehicle, pioglitazone, or fenofibrate. Corneal epithelial healing and neovascularization were assessed. Public drug-disease-target resources were integrated with RNA-seq data and single-cell transcriptomes to prioritize Chi-associated targets and pathways, which were examined by immunofluorescence, RT-PCR, and Western blotting. Ocular safety was evaluated by comprehensive ophthalmic evaluation.

Chi significantly inhibited migration and tube formation in VEGF-induced HUVECs, and flow cytometry confirmed effective ROS reduction. In vivo, Chi markedly improved corneal conditions compared with the vehicle and showed efficacy comparable to or superior to selective PPAR-α/γ agonists, depending on the outcome measures. Bioinformatic analyses predicted PPAR-γ as the dominant isoform, with PPAR-α secondary and PPAR-δ appearing less prominent, collectively implicating oxidative stress and VEGF pathways. Immunofluorescence verified PPAR-γ activation, predominantly localized to the corneal epithelium. RT-PCR and Western blotting supported activation of antioxidant pathways and suppression of angiogenic signals, with Western blotting confirming PPAR-γ and PPAR-α activation, whereas PPAR-δ activation appeared less evident under the present conditions. Ocular examinations demonstrated a favorable safety profile.

Chi primarily activates PPAR-γ and PPAR-α, producing antioxidant and anti-angiogenic benefits, supporting its potential as a multi-target PPAR therapy for CNV.