SPARC-YAP/TAZ inhibition prevents the fibroblasts-myofibroblasts transformation

Jingxiao Du; Tianwei Qian; Yi Lu; Wenkai Zhou; Xun Xu; Chaoyang Zhang; Jingfa Zhang; Zhihua Zhang

doi:10.1016/j.yexcr.2023.113649

SPARC-YAP/TAZ inhibition prevents the fibroblasts-myofibroblasts transformation

Exp Cell Res. 2023 Aug 1;429(1):113649. doi: 10.1016/j.yexcr.2023.113649. Epub 2023 May 22.

Authors

Jingxiao Du¹, Tianwei Qian¹, Yi Lu¹, Wenkai Zhou¹, Xun Xu¹, Chaoyang Zhang², Jingfa Zhang³, Zhihua Zhang⁴

Affiliations

¹ Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; National Clinical Research Center for Eye Diseases, Shanghai Clinical Research Center for Eye Diseases, Shanghai Key Clinical Specialty, Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai engineering center for precise diagnosis and treatment of eye diseases, Shanghai, China.
² Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; National Clinical Research Center for Eye Diseases, Shanghai Clinical Research Center for Eye Diseases, Shanghai Key Clinical Specialty, Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai engineering center for precise diagnosis and treatment of eye diseases, Shanghai, China. Electronic address: chaoyang.zhang@shgh.cn.
³ Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; National Clinical Research Center for Eye Diseases, Shanghai Clinical Research Center for Eye Diseases, Shanghai Key Clinical Specialty, Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai engineering center for precise diagnosis and treatment of eye diseases, Shanghai, China. Electronic address: 13917311571@139.com.
⁴ Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; National Clinical Research Center for Eye Diseases, Shanghai Clinical Research Center for Eye Diseases, Shanghai Key Clinical Specialty, Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai engineering center for precise diagnosis and treatment of eye diseases, Shanghai, China. Electronic address: drzhihuazhang@126.com.

PMID: 37225012
DOI: 10.1016/j.yexcr.2023.113649

Abstract

Background: Fibrotic scar is a severe side effect of trabeculectomy, resulting in unsatisfactory outcomes for glaucoma surgery. Accumulating evidence showed human Tenon's fibroblasts (HTFs) play an important role in fibrosis formation. We previously reported that the aqueous level of secreted protein acidic and rich in cysteine (SPARC) was higher in the patients with primary angle closure glaucoma, which was associated with the failure of trabeculectomy. In this study, the potential effect and mechanism of SPARC in promoting fibrosis were explored by using HTFs.

Methods: HTFs were employed in this study and examined under a phase-contrast microscope. Cell viability was determined by CCK-8. The expressions of SPARC-YAP/TAZ signaling and the fibrosis-related markers were examined with reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR), Western blot, and immunofluorescence, subcellular fractionation was conducted to further determined the variation of YAP and phosphorylated YAP. The differential gene expressions were analyzed with RNA sequencing (RNAseq), followed by Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses.

Results: Exogenous SPARC induced HTFs-myofibroblast transformation, as evidenced by the increased expression of α-SMA, collagen I and fibronectin in both protein and mRNA levels. SPARC knockdown decreased the expressions of the above genes in TGF-β2-treated HTFs. KEGG analysis showed that the Hippo signaling pathway was mostly enriched. SPARC treatment increased the expressions of YAP, TAZ, CTGF and CYR61 as well as enhanced YAP translocation from cytoplasm to nucleus, and decreased the phosphorylation of YAP and LAST1/2, which was reversed by SPARC knockdown. Knockdown of YAP1 decreased the fibrosis-related markers, such as α-SMA, collagen I and Fibronectin, in SPARC-treated HTFs.

Conclusions: SPARC induced HTFs-myofibroblast transformation via activating YAP/TAZ signaling. Targeting SPARC-YAP/TAZ axis in HTFs might provide a novel strategy for inhibiting fibrosis formation after trabeculectomy.

Keywords: Extracellular matrix; Fibroblast; Glaucoma; SPARC; YAP; α-SMA.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Cells, Cultured
Collagen Type I / metabolism
Fibroblasts / metabolism
Fibronectins* / metabolism
Fibrosis
Humans
Myofibroblasts* / metabolism
Osteonectin / genetics
Osteonectin / metabolism

Substances

Fibronectins
Osteonectin
Collagen Type I
SPARC protein, human