Celastrol Alleviates Corneal Stromal Fibrosis by Inhibiting TGF-β1/Smad2/3-YAP/TAZ Signaling After Descemet Stripping Endothelial Keratoplasty.

Abstract

The purpose of this study was to investigate the effect of celastrol (CEL) on corneal stromal fibrosis after Descemet stripping endothelial keratoplasty (DSEK) and its associated mechanism. Rabbit corneal fibroblasts (RCFs) were isolated, cultured, and identified. A CEL-loaded positive nanomedicine (CPNM) was developed to enhance corneal penetration. CCK-8 and scratch assays were performed to evaluate cytotoxicity and the effects of CEL on the migration of RCFs. The RCFs were activated by TGF-β1 with or without CEL treatment, and then the protein expression levels of TGFβRII, Smad2/3, YAP, TAZ, TEAD1, α-SMA, TGF-β1, FN, and COLI were assessed by immunofluorescence or Western blotting (WB). An in vivo DSEK model was established in New Zealand White rabbits. The corneas were stained using H&E, YAP, TAZ, TGF-β1, Smad2/3, TGFβRII, Masson, and COLI. H&E staining of the eyeball was performed to assess the tissue toxicity of CEL at 8 weeks after DSEK. In vitro CEL treatment inhibited the proliferation and migration of RCFs induced by TGF-β1. Immunofluorescence and WB showed that CEL significantly inhibited the protein expression of TGF-β1, Smad2/3, YAP, TAZ, TEAD1, α-SMA, TGF-βRII, FN, and COL1 induced by TGF-β1 in RCFs. In the rabbit DSEK model, CEL significantly reduced the levels of YAP, TAZ, TGF-β1, Smad2/3, TGFβRII, and collagen. No obvious tissue toxicity was observed in the CPNM group. CEL effectively inhibited corneal stromal fibrosis after DSEK. The TGF-β1/Smad2/3-YAP/TAZ pathway may be involved in the mechanism by which CEL alleviates corneal fibrosis. The CPNM is a safe and effective treatment strategy for corneal stromal fibrosis after DSEK.