Long non-coding RNA H19X as a regulator of mononuclear cell adhesion to the endothelium in systemic sclerosis

Francesca Tirelli; Elena Pachera; Sabrina Gmür; Robert Lafyatis; Mengqi Huang; Francesco Zulian; Eva Camarillo Retamosa; Gabriela Kania; Oliver Distler

doi:10.1093/rheumatology/keae034

Long non-coding RNA H19X as a regulator of mononuclear cell adhesion to the endothelium in systemic sclerosis

Rheumatology (Oxford). 2024 Feb 1:keae034. doi: 10.1093/rheumatology/keae034. Online ahead of print.

Authors

Francesca Tirelli^{1

2}, Elena Pachera¹, Sabrina Gmür¹, Robert Lafyatis³, Mengqi Huang³, Francesco Zulian², Eva Camarillo Retamosa¹, Gabriela Kania¹, Oliver Distler¹

Affiliations

¹ Center of Experimental Rheumatology, Department of Rheumatology, University Hospital Zurich, University of Zurich, Zürich, Switzerland.
² Rheumatology Unit, Department of Woman and Child Health, University Hospital of Padua, Padua, Italy.
³ Division of Rheumatology and Clinical Immunology, University of Pittsburgh, Pittsburgh, Pennsylvania.

PMID: 38305495
DOI: 10.1093/rheumatology/keae034

Abstract

Objective: To define the functional relevance of H19 X-linked co-expressed lncRNA (H19X) in endothelial cell (EC) activation as a key process in systemic sclerosis (SSc) vasculopathy.

Methods: H19X expression in SSc skin biopsies was analyzed from single cell RNA sequencing (scRNA-seq) data. Differential expression and pathway enrichment analysis between cells expressing (H19Xpos) and non expressing H19X (H19Xneg) cells was performed. H19X function was investigated in human dermal microvascular EC (HDMECs) by silencing. H19X and EC adhesion molecules levels were analyzed by RT-qPCR and Western Blot after stimulation with proinflammatory cytokines. Cytoskeletal rearrangements were analyzed by fluorescent staining. Endothelial adhesion was evaluated by co-culture of HDMECs and fluorescent labelled peripheral blood mononuclear cells (PBMCs). Shedding VCAM1 was evaluated by ELISA on HDMEC supernatant.

Results: scRNA-seq showed significant upregulation of H19X in SSc compared with healthy EC. In HDMEC, H19X was consistently induced by type I and II interferons. H19X knockdown lead to a significant decrease of the mRNA of several adhesion molecules. Particularly, vascular cell adhesion protein 1 (VCAM1) was significantly reduced at protein and mRNA levels. Co-expression analysis of the scRNA-seq data confirmed a higher expression of VCAM1 in (H19Xpos) EC. EC were also strongly associated with the 'cell adhesion molecule' pathway. Moreover, VCAM1 downstream pathway displayed less activation following H19X knockdown. Contractility of HDMEC, PBMC adhesion to HDMEC and VCAM1 shedding were also reduced following H19X knockdown.

Conclusions: lncRNA H19X may contribute to EC activation in SSc vasculopathy, acting as a regulator of expression of adhesion molecules in EC.

Keywords: H19X; VCAM1; activated endothelium; adhesion molecules; interferons; long non-coding RNAs; microvascular endothelial cells; scRNA-seq; systemic sclerosis; vasculopathy.