Congenital heart diseases (CHDs), including hypoplastic left heart syndrome (HLHS), are genetically complex and poorly understood. Here, a multi-disciplinary platform was established to functionally evaluate novel CHD gene candidates, based on whole genome and iPSC RNA sequencing of a HLHS family-trio. Filtering for rare variants and altered expression in proband iPSCs prioritized 10 candidates. siRNA/RNAi-mediated knockdown in generic human iPSC-derived cardiomyocytes (hiPSC-CM) and in developing Drosophila and zebrafish hearts revealed that LDL receptor-related protein LRP2 is required for cardiomyocyte proliferation and differentiation. Consistent with hypoplastic heart defects, compared to patents the proband's iPSC-CMs exhibited reduced proliferation. Interestingly, rare, predicted-damaging LRP2 variants were enriched in a HLHS cohort; however, understanding their contribution to HLHS requires further investigation. Collectively, we have established a multi-species high-throughput platform to rapidly evaluate candidate genes and their interactions during heart development, which are crucial first steps towards deciphering oligogenic underpinnings of CHDs, including maladaptive left hearts.
- Alexandre R Colas
- Rolf Bodmer
- Rolf Bodmer
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Animal experimentation: SBP has retained the services of a veterinarian who is a diplomat of the American College of Laboratory Animal Medicine. Close contact with Animal Facility personnel is maintained through telephone calls and on-campus visits once a week. This person is a member of the Institute's Animal Care and Use Committee (IACUC)and attends monthly meetings. This study was performed in strict accordance with the recommendations in the Guide for the Care and Use of Laboratory Animals of the National Institutes of Health. All of the animals were handled according to the Institute's Animal Care and Use Program, which is accredited by AAALAC International, and a Multiple Project Assurance A3053-1 is on file in the OLAW, DHHS. The protocol was approved by SBP IACUC (Permit Number: 19-087). Animals are euthanized after filming hearts by an overdose of anesthetic (3-aminobenzoic acid ethyl ester (MS-222) at 250-300 mg/L.
Human subjects: Written informed consent was obtained for the index family and an HLHS cohort, under a research protocol approved by the Mayo Clinic Institutional Review Board (11-000114 "Genetic Investigations in Hypoplastic Left Heart Syndrome").
- Antje Ebert
© 2020, Theis et al.
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