Knockdown of YAP/TAZ Inhibits the Migration and Invasion of Fibroblast Synovial Cells in Rheumatoid Arthritis by Regulating Autophagy.

Wei Zhou,Yang Zhou,Jing Zeng,Zijing Deng,Chen Zhang,Jie Yang,Yu Zhang,Weigan Shen,Keyan Wu,Qin Shen,Hui Wang,Elizabeth Soares Fernandes

doi:10.1155/2020/9510594

Abstract

The purpose of this study was to investigate the effect of knockdown of the yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ) on the migration and invasion of the rheumatoid arthritis fibroblast-like synoviocytes (RA-FLS) and to preliminarily elucidate the mechanisms between YAP/TAZ and autophagy in the migration and invasion of RA-FLS. RA-FLS stable knockdown of YAP or TAZ was successfully established by using lentiviral-mediated gene knockdown techniques. Wound healing assay and Transwell assay were used to evaluate the effect of knockdown of YAP or TAZ on the migration and invasion of RA-FLS. Reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) and western blotting assays were performed to examine the expression of indicated genes. The results showed that YAP and TAZ were upregulated in RA-FLS, and knockdown of YAP or TAZ inhibited the migration and invasion, reduced the expression of N-cadherin and Vimentin, and increased the accumulation of E-cadherin and β-catenin in RA-FLS. Our results also demonstrated that knockdown of YAP or TAZ promoted autophagy which increased the accumulation of LC3B-II and ULK1 and decreased the amount of SQSTM1/p62 in RA-FLS. Furthermore, our data displayed that inhibition of autophagy either with 3-MA or CQ can partially reverse the decrease of migration and invasion induced by YAP and TAZ knockdown in RA-FLS. Our experiments preliminarily revealed that YAP/TAZ and autophagy play important roles in the migration and invasion of RA-FLS, which might provide novel targets for the treatment of RA.

Highlights

Rheumatoid arthritis (RA) is a chronic, systemic autoimmune disease characterized by inflammation of the synovium, leading to destruction of cartilage and underlying bone
We found that both mRNA and protein levels of yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ) in rheumatoid arthritis fibroblast-like synoviocytes (RA-FLS) were obviously upregulated in RA-FLS compared with those in NC-FLS, suggesting that YAP and TAZ might serve function as regulators in RA-FLS
The results showed that the mRNA levels of connective tissue growth factor (CTGF) and cysteine-rich angiogenic inducer 61 (CYR61) were significantly decreased in YAP or TAZ knocking down RA-FLS compared with the stably expressing control shRNA (see Figure 2(d))

Summary

Introduction

Rheumatoid arthritis (RA) is a chronic, systemic autoimmune disease characterized by inflammation of the synovium, leading to destruction of cartilage and underlying bone. YAP (yes-associated protein) and TAZ (transcriptional coactivator with PDZ-binding motif) are downstream effectors of the Hippo signaling pathway [10, 11]. Both YAP and TAZ are transcriptional coactivators and can translocate into the nucleus and interact with transcription factors including TEA domain family members (TEADs) to regulate the expression of related genes that participate in the regulation of cell proliferation, epithelial-mesenchymal transition (EMT), cell motility, and cell fate [12, 13]

Objectives

Methods

Results

Conclusion