Almazov National Medical Research Centre Saint-Petersburg, Saint Petersburg City, Russia
Abstract: The Notch signaling pathway is an evolutionarily conservative mechanism of cellular communication, regulating the processes of differentiation. Notch is essential for bone regeneration through the regulation of osteoblasts (OBs) and osteoclasts production as well as arteriovenous differentiation of endothelial cells (ECs). Calcific aortic valve disease (CAVD) is characterized by pathological osteogenic differentiation of aortic valve interstitial cells. The Notch pathway is an essential signaling pathway of aortic valve development and the NOTCH1 mutations are the first genetic variants identified for CAVD in human. However, the role of Notch in the pathologic osteogenic differentiation in CAVD remains unclear. The aim of this work was to analyze how the activation/suppression of Notch pathway components in endothelial cells influences osteogenic differentiation in endothelial-mesenchymal cocultures in normal and pathological osteogenic differentiation. Primary human OBs and HUVECs cocultures were used as normal osteogenic differentiation; aortic valve endothelial cells (VECs) and valve interstitial cell (VICs) were used for the analysis of pathological osteogenic differentiation. ECs were modified with lentiviral human intracellular domains of Notch1 or Notch3 receptors for activation, or by short hairpin RNA to a NOTCH1 or NOTCH3 genes for knockdown. Transduced ECs were co-cultured with intact OBs/VICs in osteogenic conditions. NOTCH1 activation increased osteogenic differentiation only in HUVECs-OBs co-cultures, while activation of NOTCH3 in ECs enhanced calcium deposition in both VECs-VICs and HUVECs-OBs cocultures. Suppression of the NOTCH1 in ECs had an inhibitory effect on osteogenic differentiation of both cocultures. Suppression of the NOTCH3 inhibited osteogenic differentiation in HUVECs-OBs, but had the opposite effect in VECs-VICs cocultures. Thus, modification of the Notch pathway in aortic valve endothelial cells could be a promising tool for developing a therapy to prevent CAVD progression.
Funding Source: Supported by RSF grant 23-15-00320
