5'RNA-seq analysis of hypertrophic cardiomyopathy (HCM) in mice that carry a human missence mutation in the myosin heavy chain
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE52038 | GEO | 2013/11/05
SECONDARY ACCESSION(S): PRJNA226563
REPOSITORIES: GEO
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Project description:We developed a 5'RNA-seq methodology to concurrently assess gene expression and start-site usage changes. We applied this methodology to study hypertrophic cardiomyopathy in mice harboring a human deleterious mutation. 5'RNA-seq analysis of transcriptomes from mouse hearts with or without hypertrophic cardiomyopathy. Biological replicates were pooled into a single sequencing run. 5'RNA-seq methodology consists of enhanced sequencing of 5' ends and computational assessment of changes at start-sites of genes.
2013-11-05 | E-GEOD-52038 | biostudies-arrayexpress
Project description:RationaleApproximately 40% of hypertrophic cardiomyopathy (HCM) is caused by heterozygous missense mutations in β-cardiac myosin heavy chain (β-MHC). Associating disease phenotype with mutation is confounded by extensive background genetic and lifestyle/environmental differences between subjects even from the same family.ObjectiveTo characterize disease caused by β-cardiac myosin heavy chain Val606Met substitution (VM) that has been identified in several HCM families with wide variation of clinical outcomes, in mice.Methods and resultsUnlike 2 mouse lines bearing the malignant myosin mutations Arg453Cys (RC/+) or Arg719Trp (RW/+), VM/+ mice with an identical inbred genetic background lacked hallmarks of HCM such as left ventricular hypertrophy, disarray of myofibers, and interstitial fibrosis. Even homozygous VM/VM mice were indistinguishable from wild-type animals, whereas RC/RC- and RW/RW-mutant mice died within 9 days after birth. However, hypertrophic effects of the VM mutation were observed both in mice treated with cyclosporine, a known stimulator of the HCM response, and compound VM/RC heterozygous mice, which developed a severe HCM phenotype. In contrast to all heterozygous mutants, both systolic and diastolic function of VM/RC hearts was severely impaired already before the onset of cardiac remodeling.ConclusionsThe VM mutation per se causes mild HCM-related phenotypes; however, in combination with other HCM activators it exacerbates the HCM phenotype. Double-mutant mice are suitable for assessing the severity of benign mutations.
| S-EPMC4086907 | biostudies-literature
Project description:More than 60% of hypertrophic cardiomyopathy (HCM)-causing mutations are found in the gene loci encoding cardiac myosin-associated proteins including myosin heavy chain (MHC) and myosin binding protein C (MyBP-C). Moreover, patients with more than one independent HCM mutation may be at increased risk for more severe disease expression and adverse outcomes. However detailed mechanistic understanding, especially at early stages of disease progression, is limited. To identify early-stage HCM triggers, we generated single (MYH7 c.2167C > T [R723C] with a known pathogenic significance in the MHC converter domain) and double (MYH7 c.2167C > T [R723C]; MYH6 c.2173C > T [R725C] with unknown significance) myosin gene mutations in human induced pluripotent stem cells (hiPSCs) using a base-editing strategy. Cardiomyocytes (CMs) derived from hiPSCs with either single or double mutation exhibited phenotypic characteristics consistent with later-stage HCM including hypertrophy, multinucleation, altered calcium handling, metabolism, and arrhythmia. We then probed mutant CMs at time points prior to the detection of known HCM characteristics. We found MYH7/MYH6 dual mutation dysregulated extracellular matrix (ECM) remodeling, altered integrin expression, and interrupted cell-ECM adhesion by limiting the formation of focal adhesions. These results point to a new phenotypic feature of early-stage HCM and reveal novel therapeutic avenues aimed to delay or prohibit disease onset.
| S-EPMC9245526 | biostudies-literature
Project description:Hypertrophic cardiomyopathy (HCM) is the most common genetic cardiac disease. Fourteen sarcomeric and sarcomere-related genes have been implicated in HCM etiology, those encoding ?-myosin heavy chain (MYH7) and cardiac myosin binding protein C (MYBPC3) reported as the most frequently mutated: in fact, these account for around 50% of all cases related to sarcomeric gene mutations, which are collectively responsible for approximately 70% of all HCM cases. Here, we used denaturing high-performance liquid chromatography followed by bidirectional sequencing to screen the coding regions of MYH7 and MYBPC3 in a cohort (n?=?125) of Italian patients presenting with HCM. We found 6 MHY7 mutations in 9/125 patients and 18 MYBPC3 mutations in 19/125 patients. Of the three novel MYH7 mutations found, two were missense, and one was a silent mutation; of the eight novel MYBPC3 mutations, one was a substitution, three were stop codons, and four were missense mutations. Thus, our cohort of Italian HCM patients did not harbor the high frequency of mutations usually found in MYH7 and MYBPC3. This finding, coupled to the clinical diversity of our cohort, emphasizes the complexity of HCM and the need for more inclusive investigative approaches in order to fully understand the pathogenesis of this disease.
| S-EPMC3229838 | biostudies-literature
Project description:The R403Q mutation in the beta-myosin heavy chain (MHC) was the first mutation to be linked to familial hypertrophic cardiomyopathy (FHC), a primary disease of heart muscle. The initial studies with R403Q myosin, isolated from biopsies of patients, showed a large decrease in myosin motor function, leading to the hypothesis that hypertrophy was a compensatory response. The introduction of the mouse model for FHC (the mouse expresses predominantly alpha-MHC as opposed to the beta-isoform in larger mammals) created a new paradigm for FHC based on finding enhanced motor function for R403Q alpha-MHC. To help resolve these conflicting mechanisms, we used a transgenic mouse model in which the endogenous alpha-MHC was largely replaced with transgenically encoded beta-MHC. A His(6) tag was cloned at the N terminus of the alpha-and beta-MHC to facilitate protein isolation by Ni(2+)-chelating chromatography. Characterization of the R403Q alpha-MHC by the in vitro motility assay showed a 30-40% increase in actin filament velocity compared with wild type, consistent with published studies. In contrast, the R403Q mutation in a beta-MHC backbone showed no enhancement in velocity. Cleavage of the His-tagged myosin by chymotrypsin made it possible to isolate homogeneous myosin subfragment 1 (S1), uncontaminated by endogenous myosin. We find that the actin-activated MgATPase activity for R403Q alpha-S1 is approximately 30% higher than for wild type, whereas the enzymatic activity for R403Q beta-S1 is reduced by approximately 10%. Thus, the functional consequences of the mutation are fundamentally changed depending upon the context of the cardiac MHC isoform.
| S-EPMC2459289 | biostudies-literature
Project description:BackgroundThe HCMR (Hypertrophic Cardiomyopathy Registry) is a National Heart, Lung, and Blood Institute-funded, prospective registry of 2,755 patients with hypertrophic cardiomyopathy (HCM) recruited from 44 sites in 6 countries.ObjectivesThe authors sought to improve risk prediction in HCM by incorporating cardiac magnetic resonance (CMR), genetic, and biomarker data.MethodsDemographic and echocardiographic data were collected. Patients underwent CMR including cine imaging, late gadolinium enhancement imaging (LGE) (replacement fibrosis), and T1 mapping for measurement of extracellular volume as a measure of interstitial fibrosis. Blood was drawn for the biomarkers N-terminal pro-B-type natriuretic peptide (NT-proBNP) and high-sensitivity cardiac troponin T (cTnT), and genetic analysis.ResultsA total of 2,755 patients were studied. Mean age was 49 ± 11 years, 71% were male, and 17% non-white. Mean ESC (European Society of Cardiology) risk score was 2.48 ± 0.56. Eighteen percent had a resting left ventricular outflow tract (LVOT) gradient ≥30 mm Hg. Thirty-six percent had a sarcomere mutation identified, and 50% had any LGE. Sarcomere mutation-positive patients were more likely to have reverse septal curvature morphology, LGE, and no significant resting LVOT obstruction. Those that were sarcomere mutation negative were more likely to have isolated basal septal hypertrophy, less LGE, and more LVOT obstruction. Interstitial fibrosis was present in segments both with and without LGE. Serum NT-proBNP and cTnT levels correlated with increasing LGE and extracellular volume in a graded fashion.ConclusionsThe HCMR population has characteristics of low-risk HCM. Ninety-three percent had no or only mild functional limitation. Baseline data separated patients broadly into 2 categories. One group was sarcomere mutation positive and more likely had reverse septal curvature morphology, more fibrosis, but less resting obstruction, whereas the other was sarcomere mutation negative and more likely had isolated basal septal hypertrophy with obstruction, but less fibrosis. Further follow-up will allow better understanding of these subgroups and development of an improved risk prediction model incorporating all these markers.
| S-EPMC6905038 | biostudies-literature
Project description:Cardiac biopsies were obtained from hypertrophic cardiomyopathy (HCM) patients and controls and subjected to mRNA profiling.
2024-11-12 | GSE249925 | GEO
Project description:Our aim was to investigate the potential functional consequences of myosin heavy chain (MHC) mutations identified in patients with familial hypertrophic cardiomyopathy. We observed the presence of a mutated beta-MHC mRNA in a formalin-fixed paraffin-embedded myocardial tissue of a proband from family A, which Geisterfer-Lowrance et al. [Geisterfer-Lowrance, Kass, Tanigawa, Vosberg, McKenna, Seidman and Seidman (1990) Cell 62, 999-1006] identified as carrying the Arg-403 to Gln mutation. Recombinant DNA methods were then used to obtain size-limited, soluble and undenatured fragments of mutated myosin subfragment 1 focused around the 403 mutation. The present analysis indicated that the 403 mutation did not quantitatively alter the actin- or ATP-binding capacities of two 246-residue or 524-residue-long recombinant MHC fragments containing this mutation. The absence of any apparent impact of the 403 mutation in the recombinant MHC fragments on interactions between actin and ATP is discussed in relation to numerous biochemical and structural reports which demonstrate the crucial role of the central MHC segment, where the 403 mutation occurs, in myosin functions.
| S-EPMC1136527 | biostudies-other
Project description:Familial hypertrophic cardiomyopathy (FHCM) is a genetic disease characterized by left ventricle (LV) or interventricular septum hypertrophy. FHCM is a common heart disease (affecting 1 out of 500 individuals) associated with genetic variants in genes related to the sarcomere, including the MYL2 (myosin light chain 2) gene that is affected in 1 to 3% of the cases. As described in this report, the genetic mutation p.Gly87Ala, rs 397516399 in the MYL2 gene is likely pathogenic. Reported here is the case of a 37-year-old Colombian man with asymmetric septal hypertrophic cardiomyopathy and ventricular tachycardia. The man had progressive symptomatology, a family history of FHCM with a dominant inheritance pattern, a mother and 2 brothers with FHCM, and 2 brothers who died suddenly before the age of 35. A molecular panel of 17 genes for hypertrophic cardiomyopathy identified a heterozygous variant, p.Gly87Ala, of the MYL2 gene. This variant can be found in Ensembl, dbSNP, and ClinVar, where it has conflicting interpretations: it either has an uncertain significance or it is likely pathogenic. This is the first report of a Colombian case of FHCM secondary to a mutation in the MYL2 gene, highlighting the importance of molecular diagnosis, genetic counseling, and bioinformatic analysis in these patients.
| S-EPMC7586884 | biostudies-literature
Project description:Human Hypertrophic Cardiomyopathy mRNA Profiling.
| PRJNA1051135 | ENA