Investigating the Pathogenesis of MYH7 Mutation Gly823Glu in Familial Hypertrophic Cardiomyopathy using a Mouse Model
August 8th, 2022
Based on the familial hereditary cardiomyopathy family found in our clinical work, we created a C57BL/6N mouse model with a point mutation (G823E) at the mouse MYH7 locus through CRISPR/Cas9-mediated genome engineering to verify this mutation.
This protocol is significant as it can provide a demonstration of ultrasound in small animals. This technique may provide insights into the discovery of pathogenic genes in hereditary cardiomyopathy. Fix the knockin mice horizontally on the platform then tilt the platform 30 degrees coddle to the knockin mouse.
Remove hair on the anterior chest wall of the knockin mice using a depilatory cream position the probe vertically with the bump facing the animal's head. Then rotate the probe counterclockwise approximately 45 degrees in the para sternal long axis view. Rotate the probe 90 degrees clockwise to obtain the para sternal short axis view.
After rotating the probe, adjust the Y axis displacement to get the correct slice. Observe the long axis image of the heart and then select M mode measurement data. Acquire ultrasound data from para sternal long axis views of mice and measure the heart rate, left ventricular ejection fraction, cardiac output, left ventricular and diastolic dimension, left ventricular and systolic dimension.
Left ventricular posterior wall and ventricular septum. The family pedigrees of hypertrophic cardiomyopathy were obtained, and all the documented family members were diagnosed with hypertrophic cardiomyopathy enrollment. Sanger sequencing confirmed the same M Y H 7 P G 8 23 E variant in all patients, but not in the healthy individuals in the families.
And 174 controls, the heterozygous M Y H 7 P G 8 23 E completely co segregated in this family. The glycine residue at Codon 8 23 in the neck domain region of M Y H 7 was highly conserved in all the available vertebrate myocin sequences. According to A C M G standards and guidelines the M Y H 7 P G 8 23 E variant was predicted to be a pathogenic variant.
The knockin mice developed age-dependent cardiac hypertrophy after birth. Echocardiography revealed that the inter ventricular septum and left ventricular posterior wall developed with increased heart rate in the knockin mice. Also confirmed by the histological analysis.
Virus ultrasound data can be obtained by rotating the probe at different angles on different sections of the mouse term.
View the full transcript and gain access to thousands of scientific videos
Overview
This study presents a C57BL/6N mouse model with a point mutation (G823E) at the MYH7 locus, created through CRISPR/Cas9. The model aims to explore the implications of this mutation in hereditary cardiomyopathy.
Key Study Components
Area of Science
- Genetics
- Cardiomyopathy
- Mouse Models
Background
- Familial hereditary cardiomyopathy is a significant health concern.
- Understanding genetic mutations can aid in disease modeling.
- CRISPR/Cas9 technology allows precise genome editing.
- Mouse models are crucial for studying human diseases.
Purpose of Study
- To create a mouse model that mimics a specific genetic mutation.
- To investigate the effects of the G823E mutation on cardiac function.
- To provide insights into the genetic basis of hereditary cardiomyopathy.
Methods Used
- CRISPR/Cas9-mediated genome engineering.
- Creation of knockin mice with the G823E mutation.
- Ultrasound imaging techniques for small animals.
- Assessment of cardiac function in the mouse model.
Main Results
- The successful generation of a mouse model with the G823E mutation.
- Demonstration of ultrasound techniques in assessing cardiac structure.
- Insights into the role of the MYH7 mutation in cardiomyopathy.
- Potential pathways for further research into pathogenic genes.
Conclusions
- The created mouse model is a valuable tool for studying hereditary cardiomyopathy.
- Ultrasound imaging can enhance our understanding of cardiac conditions.
- Future research can build on these findings to explore therapeutic avenues.
Frequently Asked Questions
Executive Industry Relevance
Genetic modeling of MYH7 mutations in familial hypertrophic cardiomyopathy (HCM) addresses a critical gap in understanding disease mechanisms and target validation for inherited cardiac disorders. The use of CRISPR/Cas9-engineered mouse models enables precise interrogation of pathogenic variants, supporting predictive confidence in early discovery and translational research. This approach informs portfolio decisions by clarifying the functional impact of candidate mutations on cardiac phenotypes.
Strategic Applications in Biopharma R&D
Early Discovery & Target Validation
- Enables direct testing of the pathogenicity of MYH7 G823E in a controlled in vivo system.
- Supports functional target validation by linking genotype to cardiac hypertrophy phenotypes.
- Facilitates mechanistic de-risking for candidate gene variants implicated in HCM.
- Provides a foundation for predictive confidence in genetic target selection.
Screening & Assay Development
- Establishes a validated mouse model for quantitative echocardiographic and histological readouts.
- Enables reproducible measurement of cardiac parameters such as wall thickness and ejection fraction.
- Supports assay standardization for downstream compound or genetic modifier screening.
- Prepares a scalable platform for evaluating therapeutic interventions targeting MYH7-driven pathology.
Translational & Preclinical Research
- Aligns preclinical model outputs with human familial HCM phenotypes for translational continuity.
- Enables risk-adjusted advancement of genetic targets based on in vivo disease relevance.
- Supports biomarker development by correlating genotype, phenotype, and quantitative cardiac measurements.
- Provides a mechanistic bridge from discovery genetics to preclinical validation in cardiac disease.
Pipeline & Workflow Integration
This CRISPR/Cas9 mouse model integrates into the discovery-to-preclinical continuum by enabling hypothesis-driven validation of MYH7 variants and supporting quantitative phenotyping workflows.
- Discovery Biology: Facilitates null hypothesis testing for variant pathogenicity and clarifies MYH7's mechanistic role in HCM.
- Screening: Provides standardized, reproducible cardiac measurements for comparative studies and intervention testing.
- Analytics: Delivers quantitative outputs such as heart rate, wall thickness, and ejection fraction for robust statistical analysis.
- Translational Research: Ensures disease-relevant modeling and continuity from genetic discovery to preclinical assessment.
- Enterprise Reuse: Establishes a reusable in vivo platform for future genetic or pharmacological studies in cardiomyopathy.
Operational & Enterprise Impact
- Scientific Value: Increases predictive confidence and reduces mechanistic ambiguity in target validation for inherited cardiac diseases.
- Operational Value: Standardizes in vivo phenotyping and supports reproducibility across research teams.
- Strategic Value: Improves go/no-go decisions and capital allocation by clarifying variant pathogenicity early in the pipeline.
- Portfolio Impact: Enables risk-adjusted prioritization of genetic targets for further development in cardiovascular indications.
Implementation Considerations
- Requires expertise in CRISPR/Cas9 genome engineering and mouse model generation.
- Demands access to echocardiography instrumentation and histological analysis capabilities.
- Necessitates cross-team standardization of cardiac measurement protocols for reproducibility.
- May require adaptation for other MYH7 variants or cardiomyopathy models as portfolio needs evolve.
- Dependent on robust statistical analysis to interpret quantitative phenotypic outputs.
