Mutations in Hnrnpa1 cause congenital heart defects
Zhe Yu, … , Binbin Wang, You-Qiang Song
Zhe Yu, … , Binbin Wang, You-Qiang Song
Published January 25, 2018
Citation Information: JCI Insight. 2018;3(2):e98555. https://doi.org/10.1172/jci.insight.98555.
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Research Article Development Genetics

Mutations in Hnrnpa1 cause congenital heart defects

Abstract

Incomplete penetrance of congenital heart defects (CHDs) was observed in a mouse model. We hypothesized that the contribution of a major genetic locus modulates the manifestation of the CHDs. After genome-wide linkage mapping, fine mapping, and high-throughput targeted sequencing, a recessive frameshift mutation of the heterogeneous nuclear ribonucleoprotein A1 (Hnrnpa1) gene was confirmed (Hnrnpa1ct). Hnrnpa1 was expressed in both the first heart field (FHF) and second heart field (SHF) at the cardiac crescent stage but was only maintained in SHF progenitors after heart tube formation. Hnrnpa1ct/ct homozygous mutants displayed complete CHD penetrance, including truncated and incomplete looped heart tube at E9.5, ventricular septal defect (VSD) and persistent truncus arteriosus (PTA) at E13.5, and VSD and double outlet right ventricle at P0. Impaired development of the dorsal mesocardium and sinoatrial node progenitors was also observed. Loss of Hnrnpa1 expression leads to dysregulation of cardiac transcription networks and multiple signaling pathways, including BMP, FGF, and Notch in the SHF. Finally, two rare heterozygous mutations of HNRNPA1 were detected in human CHDs. These findings suggest a role of Hnrnpa1 in embryonic heart development in mice and humans.

Authors

Zhe Yu, Paul L.F. Tang, Jing Wang, Suying Bao, Joseph T. Shieh, Alan W.L. Leung, Zhao Zhang, Fei Gao, Sandra Y.Y. Wong, Andy L.C. Hui, Yuan Gao, Nelson Dung, Zhi-Gang Zhang, Yanhui Fan, Xueya Zhou, Yalun Zhang, Dana S.M. Wong, Pak C. Sham, Abid Azhar, Pui-Yan Kwok, Patrick P.L. Tam, Qizhou Lian, Kathryn S.E. Cheah, Binbin Wang, You-Qiang Song

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Figure 7

KO of Hnrnpa1 impaired cardiomyocyte differentiation in vitro.

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KO of Hnrnpa1 impaired cardiomyocyte differentiation in vitro. (A) Hnrnp...
(A) Hnrnpa1 KO 1 and KO 2 mESC lines were established by the CRISPR/Cas9 method. PCR products of exon 6 in Nkx2.5-EGFP-mESCs (lane 2, 3 and 5, 425 bp), Hnrnpa1 KO 1 (lane 4, 343 bp), and KO 2 (lane 6, 404 bp) were shown. Sequencing and blasting results demonstrate that 82-bp and 21-bp fragments of exon6 of Hnrnpa1 are deleted in Hnrnpa1 KO 1 and KO 2, respectively, by the CRISPR/Cas9 technique. (B) For each group, in vitro differentiation was performed 3 times. mESCs were induced into cardiomyocytes. Embryonic bodies (EBs) formed 2–3 days later. Loosely aggregated EBs were observed in Hnrnpa1 KO 1 and KO 2 groups (day 3–5). After attachment of EBs to the plate at day 6, outgrowths were impaired in both Hnrnpa1 KO 1 and KO 2 groups (day 7–day 9). Scale bar: 200 μm. (C) The percentage of Nkx2.5-EGFP–positive cells was analyzed by flow cytometry at day 7. Compared with the Nkx2.5-EGFP-mESC group, significantly reduced Nkx2.5-EGFP–positive cells were detected in both Hnrnpa1 KO 1 and KO 2 groups. Data in C are presented as mean ± SD, with n = 3 per group. **P < 0.01; ***P < 0.001 by unpaired 2-tailed t tests with Bonferroni correction.