title: NOTCH1-Dependent Nitric Oxide Signaling Deficiency in Hypoplastic Left Heart Syndrome Revealed Through Patient-Specific Phenotypes Detected in Bioengineered Cardiogenesis.
abstract: Hypoplastic left heart syndrome (HLHS) is a severe congenital heart defect (CHD) attributable to multifactorial molecular underpinnings. Multiple genetic loci have been implicated to increase the risk of disease, yet genotype-phenotype relationships remain poorly defined. Whole genome sequencing complemented by cardiac phenotype from five individuals in an HLHS-affected family enabled the identification of NOTCH1 as a prioritized candidate gene linked to CHD in three individuals with mutant allele burden significantly impairing Notch signaling in the HLHS-affected proband. To better understand a mechanistic basis through which NOTCH1 contributes to heart development, human induced pluripotent stem cells (hiPSCs) were created from the HLHS-affected parent-proband triad and differentiated into cardiovascular cell lineages for molecular characterization. HLHS-affected hiPSCs exhibited a deficiency in Notch signaling pathway components and a diminished capacity to generate hiPSC-cardiomyocytes. Optimization of conditions to procure HLHS-hiPSC-cardiomyocytes led to an approach that compensated for dysregulated nitric oxide (NO)-dependent Notch signaling in the earliest specification stages. Augmentation of HLHS-hiPSCs with small molecules stimulating NO signaling in the first 4 days of differentiation provided a cardiomyocyte yield equivalent to the parental hiPSCs. No discernable differences in calcium dynamics were observed between the bioengineered cardiomyocytes derived from the proband and the parents. We conclude that in vitro modeling with HLHS-hiPSCs bearing NOTCH1 mutations facilitated the discovery of a NO-dependent signaling component essential for cardiovascular cell lineage specification. Potentiation of NO signaling with small therapeutic molecules restored cardiogenesis in vitro and may identify a potential therapeutic target for patients affected by functionally compromised NOTCH1 variants. Stem Cells 2017;35:1106-1119.
authors.affiliation: Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota, USA.|Department of Molecular Pharmacology & Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Sybil C L
authors.initials: SC
authors.lastname: Hrstka
authors.affiliation: Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota, USA.|Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Xing
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Molecular Pharmacology & Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota, USA.|General Internal Medicine and Transplant Center, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota, USA.|Center for Regenerative Medicine, Mayo Clinic, Rochester, Minnesota, USA.|Division of Pediatric Cardiology, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Nelson
mesh_terms: D000328:Adult; D057005:Bioengineering; D020013:Calcium Signaling / Q000187:drug effects; D006801:Humans; D018636:Hypoplastic Left Heart Syndrome / Q000378:metabolism* / Q000473:pathology*; D057026:Induced Pluripotent Stem Cells / Q000187:drug effects / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D038081:Organogenesis / Q000187:drug effects; D010641:Phenotype; D051881:Receptor, Notch1 / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D020030:Nitric Oxide Donors; D051881:Receptor, Notch1; D009569:Nitric Oxide
keywords: Cardiac; Developmental biology; Differentiation; Drug target; Hypoplastic left heart syndrome; NOTCH1; Pluripotent stem cells