GO:0003180 aortic valve morphogenesis: Genes & Methods

Aortic valve morphogenesis (GO:0003180) is the developmental process that generates and organizes the structure of the aortic valve, a trileaflet structure that ensures unidirectional blood flow from the left ventricle to the aorta. This process involves precise spatiotemporal coordination of endocardial cushion formation, cellular differentiation, extracellular matrix remodeling, and valve leaflet stratification. Defects in aortic valve morphogenesis can lead to congenital aortic valve anomalies, including bicuspid aortic valve, and increase susceptibility to calcific aortic valve disease (CAVD), a progressive disorder characterized by fibro-calcific remodeling and valve stenosis. CAVD affects a substantial proportion of the elderly population, and its molecular underpinnings are increasingly linked to developmental pathways that are reactivated or dysregulated in adulthood. Research into aortic valve morphogenesis has revealed that valve interstitial cells (VICs) and valve endothelial cells (VECs) are key players in maintaining valve homeostasis. Under pathological conditions, VICs can undergo osteogenic differentiation, a process driven by transcription factors such as RUNX2 and modulated by signaling cascades including FOXO1/SMURF2-mediated ubiquitination. Mechanical forces, including shear stress and stretch, are sensed by mechanosensitive channels like Piezo1, which promote osteogenic differentiation through YAP-dependent glutaminolysis. Metabolic shifts, such as enhanced glycolysis and inflammation, further contribute to valve calcification. Additionally, epigenetic modifications, including histone lactylation, and non-coding RNAs such as PIWI-interacting RNAs, have been implicated in the pathogenesis of CAVD [1,7]. Given the clinical burden of aortic valve disease, understanding the molecular and cellular mechanisms of aortic valve morphogenesis is essential for identifying therapeutic targets. This article synthesizes current knowledge on the genes, pathways, and experimental models relevant to GO:0003180, with a focus on how CRISPR-based approaches can accelerate discovery.

GO:0003180 aortic valve morphogenesis is defined as the process in which the structure of the aortic valve is generated and organized. This encompasses the coordinated cellular and molecular events that shape the valve leaflets, including endocardial cushion formation, cell proliferation, differentiation, extracellular matrix deposition, and remodeling. The term is a biological process within the Gene Ontology, and its proper execution is essential for normal cardiac function.

Aortic valve morphogenesis is critical for establishing a functional aortic valve that maintains unidirectional blood flow and withstands lifelong mechanical stress. Disruptions in this process can result in congenital valve malformations, such as bicuspid aortic valve, which affects approximately 1-2% of the population and is a major risk factor for calcific aortic valve disease (CAVD). CAVD is the most common valvular heart disease in developed countries, with no effective pharmacological therapy to halt its progression, making valve replacement the only definitive treatment. Understanding the molecular mechanisms of aortic valve morphogenesis provides insight into disease pathogenesis and identifies potential targets for therapeutic intervention.

The following genes and proteins have been implicated in aortic valve morphogenesis and calcific aortic valve disease, based on published literature.

Aortic valve morphogenesis and its pathological reactivation in CAVD are regulated by a complex network of signaling pathways, transcription factors, and epigenetic modifiers. Key regulatory nodes include the FOXO1/SMURF2/RUNX2 axis, which controls osteogenic differentiation through ubiquitin-mediated degradation of RUNX2. Mechanical forces sensed by Piezo1 activate YAP-dependent glutaminolysis, linking mechanotransduction to metabolic reprogramming. Epigenetic regulation via histone lactylation, driven by lumican, modulates pro-calcific gene expression. Additionally, non-coding RNAs such as AVCAPIR promote calcification, while inflammatory signaling through NF-κB and cytokines like IL6 exacerbates valve disease [7,8]. These regulatory mechanisms offer potential targets for therapeutic intervention.

Calcific aortic valve disease is characterized by progressive fibro-calcific remodeling of the aortic valve, leading to stenosis and heart failure. It involves osteogenic differentiation of valve interstitial cells, driven by transcription factors such as RUNX2 and modulated by FOXO1/SMURF2 signaling. Mechanical stress via Piezo1 promotes osteogenic differentiation through YAP-dependent glutaminolysis. Epigenetic modifications, including histone lactylation, and non-coding RNAs like AVCAPIR further contribute to calcification [1,7]. Inflammation and metabolic reprogramming are also key features. CAVD is the most common valvular heart disease, and current treatment is limited to valve replacement.

Bicuspid aortic valve is a congenital anomaly resulting from defective aortic valve morphogenesis, affecting 1-2% of the population. It is associated with mutations in NOTCH1 and other developmental genes. BAV predisposes to early-onset calcific aortic valve disease and aortic dilation. Understanding the developmental origins of BAV is critical for early diagnosis and management.

Disruptions in aortic valve morphogenesis can lead to other congenital heart defects, including aortic stenosis and regurgitation. These defects often require surgical intervention in infancy or childhood. Research into the molecular mechanisms of valve development is essential for improving outcomes.

CRISPR-Cas9 enables precise knockout, knock-in, and point mutations in genes of interest. In aortic valve research, it is used to create isogenic cell lines and animal models to study gene function in valve morphogenesis and calcification. For example, knockout of RUNX2 or FOXO1 can reveal their roles in osteogenic differentiation.

RNA-seq and ChIP-seq provide global views of gene expression and chromatin modifications. In CAVD, RNA-seq has identified differentially expressed genes and non-coding RNAs such as AVCAPIR. ChIP-seq can map histone modifications like H3 lactylation.

Microfluidic and stretch systems simulate hemodynamic forces on valve cells. Piezo1 activation and YAP signaling can be studied using these platforms.

Seahorse extracellular flux analysis and metabolomics measure glycolysis and glutaminolysis. These assays have been used to link metabolism to osteogenic differentiation in VICs [3,8].

Researchers studying aortic valve morphogenesis-related genes often need to determine whether a candidate gene is causally involved in valve development or disease. EDITGENE provides comprehensive CRISPR-based services to accelerate this discovery process, from knockout to knock-in and library screening.

Aortic valve morphogenesis (GO:0003180) is a complex developmental process essential for normal heart function. Its dysregulation contributes to congenital valve anomalies and calcific aortic valve disease, a major clinical burden. Research has identified key molecular players, including RUNX2, FOXO1, Piezo1, and epigenetic modifiers, offering potential therapeutic targets. CRISPR-based models are powerful tools to dissect these mechanisms and accelerate the development of new treatments.