The extracellular matrix glycoprotein ADAMTSL2 is increased in heart failure and inhibits TGF\u03b2 signalling in cardiac fibroblasts

Karoline B Rypdal,Ida G Lunde,Geir Christensen,Christen P Dahl,Mari E Strand,Pugazendhi M Erusappan,Dirk Hubmacher,Suneel S Apte,Theis Tønnessen,Vibeke Almaas,Sheryl Palmero,Deborah E Seifert,A Olav Melleby

doi:10.1038/s41598-021-99032-2

Abstract

Fibrosis accompanies most heart diseases and is associated with adverse patient outcomes. Transforming growth factor (TGF)β drives extracellular matrix remodelling and fibrosis in the failing heart. Some members of the ADAMTSL (a disintegrin-like and metalloproteinase domain with thrombospondin type 1 motifs-like) family of secreted glycoproteins bind to matrix microfibrils, and although their function in the heart remains largely unknown, they are suggested to regulate TGFβ activity. The aims of this study were to determine ADAMTSL2 levels in failing hearts, and to elucidate the role of ADAMTSL2 in fibrosis using cultured human cardiac fibroblasts (CFBs). Cardiac ADAMTSL2 mRNA was robustly increased in human and experimental heart failure, and mainly expressed by fibroblasts. Over-expression and treatment with extracellular ADAMTSL2 in human CFBs led to reduced TGFβ production and signalling. Increased ADAMTSL2 attenuated myofibroblast differentiation, with reduced expression of the signature molecules α-smooth muscle actin and osteopontin. Finally, ADAMTSL2 mitigated the pro-fibrotic CFB phenotypes, proliferation, migration and contractility. In conclusion, the extracellular matrix-localized glycoprotein ADAMTSL2 was upregulated in fibrotic and failing hearts of patients and mice. We identified ADAMTSL2 as a negative regulator of TGFβ in human cardiac fibroblasts, inhibiting myofibroblast differentiation and pro-fibrotic properties.

Highlights

HfCFB Human foetal cardiac fibroblast hypertrophic obstructive cardiomyopathy (HOCM) Hypertrophic obstructive cardiomyopathy left atrium (LA) Left atrium large latent complex (LLC) Large latent complex LTBP1 Latent TGFβ binding protein left ventricles (LV) Left ventricle small latency complex (SLC) Small latent complex TGFβ Transforming growth factor beta
Cardiac fibrosis and increased TGFβ signalling was present at all three time-points, with increased α-smooth muscle actin (α-SMA) observed at two w eeks[25]
In line with reduced production of TGFβ, we found that LTBP1 and the LLC were reduced in L2 cell fractions from the cytosol, extracellular matrix (ECM), and medium of mature ECM Human foetal cardiac fibroblasts (hfCFBs) cultures. (Fig. 2i–j)

Summary

Introduction

HfCFB Human foetal cardiac fibroblast HOCM Hypertrophic obstructive cardiomyopathy LA Left atrium LLC Large latent complex LTBP1 Latent TGFβ binding protein LV Left ventricle SLC Small latent complex TGFβ Transforming growth factor beta. Cardiac fibrosis results from dysregulated deposition of extracellular matrix (ECM) molecules by activated cardiac fibroblasts (CFBs), termed myofibroblasts, leading to tissue s tiffening[5,6,7]. Recessive lossof-function ADAMTSL2 mutations cause geleophysic dysplasia (GD), an inherited connective tissue disorder resulting in severe musculoskeletal, pulmonary, and cardiac anomalies, with increased TGFβ levels and activity observed in patient-derived skin fibroblasts[21,22]. Adamtsl2−/− mice fail to survive past birth, likely as a result of lung anomalies associated with bronchial fibrillin microfibril accumulation, and have cardiac developmental defects[24]. These data suggest that ADAMTSL2 regulates ECM deposition and TGFβ signalling and may have an important role in cardiac fibrosis and heart failure. In cultured foetal and adult human CFBs, ADAMTSL2 negatively regulated TGFβ signalling, and attenuated myofibroblast differentiation and pro-fibrotic properties of CFBs

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