Background: Endothelial to mesenchymal transition (EndMT) is a transdifferentiation process of cells that is associated with the development of aortic valve stenosis (AVS) in adulthood. It was shown that long non-coding RNAs are dysregulated in this process and might play a crucial role in EndMT-mediated AVS. Here we aim to elucidate the role of long non-coding RNA H19 (LncRNA H19) in the pathogenesis of EndMT-related AVS.

Methods and results: RNA sequencing of aortic valve tissue explanted from AVS-patients with coronary artery disease (CAD) revealed that H19 was significantly dysregulated. EndMT was induced in vitro in vascular and valvular endothelial cells (VECs) via TNFα and TGFß+IL1ß stimulation and expression of endothelial marker genes vWF and eNOS and mesenchymal marker genes αSMA, SM22, Vimentin and SNAI2 was confirmed by RT-qPCR. Loss of function of H19 followed by EndMT induction demonstrated distinct changes in gene expression profile and protein levels which were detected by qRT-PCR, immunoblotting, and immunofluorescence. Further experiments indicate that loss of H19 may promote EndMT. Functional assays in vascular and valvular endothelial cells suggested that H19 is a critical regulator of angiogenic sprouting and migration. To unveil the specific molecular signature in angiogenesis a RT² profiler array was performed to identify the regulation of angiogenesis with 84 angiogenesis-related genes. Our assay revealed JAG1 as a potential dysregulated candidate with a 4.43-fold regulation. Further molecular mechanism will be investigated via identification of binding partners and downstream targets of H19 in EndMT by using primary cells and VECs.

Conclusion: Our data suggests that H19 might play a role in EndMT in context of AVS. Further investigation by using a murine model of AVS should confirm the H19-mediated of EndMT in the development of AVS.