Research Fellow Institute of Cytology RAS Saint Petersburg, Saint Petersburg City, Russia
Abstract: Calcific aortic valve disease (CAVD) is a progressive disorder characterized by pathological calcification of human aortic valve interstitial cells (HAVICs). Despite advances in understanding its pathogenesis, the molecular pathways underlying sex-specific differences in CAVD remain poorly understood. This study aims to explore mechanisms regulating osteogenic differentiation in HAVICs. Clinical assessments revealed that men exhibited a higher calcification burden, with significantly elevated Agatston scores and 18F-NaF uptake, while women demonstrated increased fibrosis, consistent with differences in the OPG/sRANKL axis. To investigate these differences, we isolated HAVICs from men and women and performed transcriptomic and proteomic analyses. These analyses revealed that 1,210 genes and 70 proteins exhibited sex-specific expression during osteogenic differentiation, with Wnt/β-catenin signaling emerging as a key regulatory pathway. To further examine the functional impact of Wnt signaling, we activated the canonical Wnt pathway in HAVIC cultures undergoing osteogenic differentiation. Remarkably, Wnt activation inhibited differentiation, as evidenced by reduced calcium deposition and lower expression of osteogenic markers. Furthermore, Wnt activation decreased caspase-1 activity, suggesting a suppression of inflammation. Transcriptomic analysis of Wnt-activated HAVICs revealed downregulation of FGD4, a gene that was previously upregulated during differentiation. Interestingly, endothelial-associated markers were also upregulated, indicating a potential proangiogenic shift under Wnt activation. This study highlights key sex-specific molecular mechanisms involved in CAVD. Our transcriptomic and proteomic findings identify Wnt/β-catenin signaling as a central pathway regulating osteogenic differentiation in HAVICs. Activation of this pathway not only suppressed osteogenesis but also reduced caspase-1 activity and induced endothelial phenotypic changes, accompanied by decreased FGD4 expression. These results provide new insights into the links between inflammation, endothelial transitions, and calcification, suggesting that targeting Wnt/β-catenin signaling could hold therapeutic potential for developing sex-specific treatments for CAVD.
Funding Source: This study was supported by the Ministry of Science and Higher Education of the Russian Federation (Agreement No. 075-15-2022-301, dated 04/20/2022).
