PT  - JOURNAL ARTICLE
AU  - Zihao Li
AU  - Siwen Chen
AU  - Haowen Cui
AU  - Xiang Li
AU  - Dongying Chen
AU  - Wenjun Hao
AU  - Jianru Wang
AU  - Zemin Li
AU  - Zhaomin Zheng
AU  - Zhongping Zhang
AU  - Hui Liu
TI  - Tenascin-C-mediated suppression of extracellular matrix adhesion force promotes entheseal new bone formation through activation of Hippo signalling in ankylosing spondylitis
AID  - 10.1136/annrheumdis-2021-220002
DP  - 2021 Jul 01
TA  - Annals of the Rheumatic Diseases
PG  - 891--902
VI  - 80
IP  - 7
4099  - http://ard.bmj.com/content/80/7/891.short
4100  - http://ard.bmj.com/content/80/7/891.full
SO  - Ann Rheum Dis2021 Jul 01; 80
AB  - Objectives The aim of this study was to identify the role of tenascin-C (TNC) in entheseal new bone formation and to explore the underlying molecular mechanism.Methods Ligament tissue samples were obtained from patients with ankylosing spondylitis (AS) during surgery. Collagen antibody-induced arthritis and DBA/1 models were established to observe entheseal new bone formation. TNC expression was determined by immunohistochemistry staining. Systemic inhibition or genetic ablation of TNC was performed in animal models. Mechanical properties of extracellular matrix (ECM) were measured by atomic force microscopy. Downstream pathway of TNC was analysed by RNA sequencing and confirmed with pharmacological modulation both in vitro and in vivo. Cellular source of TNC was analysed by single-cell RNA sequencing (scRNA-seq) and confirmed by immunofluorescence staining.Results TNC was aberrantly upregulated in ligament and entheseal tissues from patients with AS and animal models. TNC inhibition significantly suppressed entheseal new bone formation. Functional assays revealed that TNC promoted new bone formation by enhancing chondrogenic differentiation during endochondral ossification. Mechanistically, TNC suppressed the adhesion force of ECM, resulting in the activation of downstream Hippo/yes-associated protein signalling, which in turn increased the expression of chondrogenic genes. scRNA-seq and immunofluorescence staining further revealed that TNC was majorly secreted by fibroblast-specific protein-1 (FSP1)+fibroblasts in the entheseal inflammatory microenvironment.Conclusion Inflammation-induced aberrant expression of TNC by FSP1+fibroblasts promotes entheseal new bone formation by suppressing ECM adhesion forces and activating Hippo signalling.Data are available upon reasonable request. The data that support the findings in this study are available from the corresponding author upon request.