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Anzell AR, Kunz AB, Donovan JP, Tran TG, Lu X, Young S, Roman BL. Blood flow regulates acvrl1 transcription via ligand-dependent Alk1 activity. bioRxiv 2024:2024.01.25.576046. [PMID: 38328175 PMCID: PMC10849739 DOI: 10.1101/2024.01.25.576046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disease characterized by the development of arteriovenous malformations (AVMs) that can result in significant morbidity and mortality. HHT is caused primarily by mutations in bone morphogenetic protein receptors ACVRL1/ALK1, a signaling receptor, or endoglin (ENG), an accessory receptor. Because overexpression of Acvrl1 prevents AVM development in both Acvrl1 and Eng null mice, enhancing ACVRL1 expression may be a promising approach to development of targeted therapies for HHT. Therefore, we sought to understand the molecular mechanism of ACVRL1 regulation. We previously demonstrated in zebrafish embryos that acvrl1 is predominantly expressed in arterial endothelial cells and that expression requires blood flow. Here, we document that flow dependence exhibits regional heterogeneity and that acvrl1 expression is rapidly restored after reinitiation of flow. Furthermore, we find that acvrl1 expression is significantly decreased in mutants that lack the circulating Alk1 ligand, Bmp10, and that BMP10 microinjection into the vasculature in the absence of flow enhances acvrl1 expression in an Alk1-dependent manner. Using a transgenic acvrl1:egfp reporter line, we find that flow and Bmp10 regulate acvrl1 at the level of transcription. Finally, we observe similar ALK1 ligand-dependent increases in ACVRL1 in human endothelial cells subjected to shear stress. These data suggest that Bmp10 acts downstream of blood flow to maintain or enhance acvrl1 expression via a positive feedback mechanism, and that ALK1 activating therapeutics may have dual functionality by increasing both ALK1 signaling flux and ACVRL1 expression.
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Affiliation(s)
- Anthony R. Anzell
- Department of Human Genetics, University of Pittsburgh School of Public Health, Pittsburgh, PA, USA
- Pittsburgh Heart, Lung and Blood Vascular Medicine Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Amy Biery Kunz
- Department of Human Genetics, University of Pittsburgh School of Public Health, Pittsburgh, PA, USA
- Current affiliation: Allegheny Health Network, Pittsburgh, PA, USA
| | - James P. Donovan
- Department of Human Genetics, University of Pittsburgh School of Public Health, Pittsburgh, PA, USA
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Thanhlong G. Tran
- Department of Human Genetics, University of Pittsburgh School of Public Health, Pittsburgh, PA, USA
- Current affiliation: National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Xinyan Lu
- Department of Human Genetics, University of Pittsburgh School of Public Health, Pittsburgh, PA, USA
| | - Sarah Young
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
- Current affiliation: Carnegie Mellon University, University Libraries, Pittsburgh, PA, USA
| | - Beth L. Roman
- Department of Human Genetics, University of Pittsburgh School of Public Health, Pittsburgh, PA, USA
- Pittsburgh Heart, Lung and Blood Vascular Medicine Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
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