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Jang MY, Patel PN, Pereira AC, Willcox JA, Haghighi A, Tai AC, Ito K, Morton SU, Gorham JM, McKean DM, DePalma SR, Bernstein D, Brueckner M, Chung WK, Giardini A, Goldmuntz E, Kaltman JR, Kim R, Newburger JW, Shen Y, Srivastava D, Tristani-Firouzi M, Gelb BD, Porter GA, Seidman CE, Seidman JG. Contribution of Previously Unrecognized RNA Splice-Altering Variants to Congenital Heart Disease. Circ Genom Precis Med 2023; 16:224-231. [PMID: 37165897 PMCID: PMC10404383 DOI: 10.1161/circgen.122.003924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 03/13/2023] [Indexed: 05/12/2023]
Abstract
BACKGROUND Known genetic causes of congenital heart disease (CHD) explain <40% of CHD cases, and interpreting the clinical significance of variants with uncertain functional impact remains challenging. We aim to improve diagnostic classification of variants in patients with CHD by assessing the impact of noncanonical splice region variants on RNA splicing. METHODS We tested de novo variants from trio studies of 2649 CHD probands and their parents, as well as rare (allele frequency, <2×10-6) variants from 4472 CHD probands in the Pediatric Cardiac Genetics Consortium through a combined computational and in vitro approach. RESULTS We identified 53 de novo and 74 rare variants in CHD cases that alter splicing and thus are loss of function. Of these, 77 variants are in known dominant, recessive, and candidate CHD genes, including KMT2D and RBFOX2. In 1 case, we confirmed the variant's predicted impact on RNA splicing in RNA transcripts from the proband's cardiac tissue. Two probands were found to have 2 loss-of-function variants for recessive CHD genes HECTD1 and DYNC2H1. In addition, SpliceAI-a predictive algorithm for altered RNA splicing-has a positive predictive value of ≈93% in our cohort. CONCLUSIONS Through assessment of RNA splicing, we identified a new loss-of-function variant within a CHD gene in 78 probands, of whom 69 (1.5%; n=4472) did not have a previously established genetic explanation for CHD. Identification of splice-altering variants improves diagnostic classification and genetic diagnoses for CHD. REGISTRATION URL: https://clinicaltrials.gov; Unique identifier: NCT01196182.
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Affiliation(s)
- Min Young Jang
- Departments of Genetics (M.Y.J., P.N.P., A.C.P., J.A.L.W., A.H., A.C.T., S.U.M., J.M.G., D.M.M., S.R.D., C.E.S., J.G.S.), Harvard Medical School, Boston, MA
- Department of Medicine (M.Y.J., A.H.), Brigham and Women’s Hospital, Boston, MA
| | - Parth N. Patel
- Departments of Genetics (M.Y.J., P.N.P., A.C.P., J.A.L.W., A.H., A.C.T., S.U.M., J.M.G., D.M.M., S.R.D., C.E.S., J.G.S.), Harvard Medical School, Boston, MA
- Division of Cardiology, Massachusetts General Hospital, Boston, MA (P.N.P.)
| | - Alexandre C. Pereira
- Departments of Genetics (M.Y.J., P.N.P., A.C.P., J.A.L.W., A.H., A.C.T., S.U.M., J.M.G., D.M.M., S.R.D., C.E.S., J.G.S.), Harvard Medical School, Boston, MA
| | - Jon A.L. Willcox
- Departments of Genetics (M.Y.J., P.N.P., A.C.P., J.A.L.W., A.H., A.C.T., S.U.M., J.M.G., D.M.M., S.R.D., C.E.S., J.G.S.), Harvard Medical School, Boston, MA
| | - Alireza Haghighi
- Departments of Genetics (M.Y.J., P.N.P., A.C.P., J.A.L.W., A.H., A.C.T., S.U.M., J.M.G., D.M.M., S.R.D., C.E.S., J.G.S.), Harvard Medical School, Boston, MA
- Department of Medicine (M.Y.J., A.H.), Brigham and Women’s Hospital, Boston, MA
| | - Angela C. Tai
- Departments of Genetics (M.Y.J., P.N.P., A.C.P., J.A.L.W., A.H., A.C.T., S.U.M., J.M.G., D.M.M., S.R.D., C.E.S., J.G.S.), Harvard Medical School, Boston, MA
| | - Kaoru Ito
- Laboratory for Cardiovascular Diseases, RIKEN Center for Integrative Medical Sciences, Yokohama, Japan (K.I.)
| | - Sarah U. Morton
- Departments of Genetics (M.Y.J., P.N.P., A.C.P., J.A.L.W., A.H., A.C.T., S.U.M., J.M.G., D.M.M., S.R.D., C.E.S., J.G.S.), Harvard Medical School, Boston, MA
- Pediatrics (S.U.M.), Harvard Medical School, Boston, MA
| | - Joshua M. Gorham
- Departments of Genetics (M.Y.J., P.N.P., A.C.P., J.A.L.W., A.H., A.C.T., S.U.M., J.M.G., D.M.M., S.R.D., C.E.S., J.G.S.), Harvard Medical School, Boston, MA
| | - David M. McKean
- Departments of Genetics (M.Y.J., P.N.P., A.C.P., J.A.L.W., A.H., A.C.T., S.U.M., J.M.G., D.M.M., S.R.D., C.E.S., J.G.S.), Harvard Medical School, Boston, MA
| | - Steven R. DePalma
- Departments of Genetics (M.Y.J., P.N.P., A.C.P., J.A.L.W., A.H., A.C.T., S.U.M., J.M.G., D.M.M., S.R.D., C.E.S., J.G.S.), Harvard Medical School, Boston, MA
- Division of Cardiology (S.R.D., C.E.S.), Brigham and Women’s Hospital, Boston, MA
| | - Daniel Bernstein
- Department of Pediatrics, Stanford University, Palo Alto, CA (D.B.)
| | - Martina Brueckner
- Departments of Genetics (M.B.), Yale University School of Medicine, New Haven, CT
- Pediatric Cardiology (M.B.), Yale University School of Medicine, New Haven, CT
| | - Wendy K. Chung
- Departments of Pediatrics (W.K.C.), Columbia University Medical Center, New York, NY
- Medicine (W.K.C.), Columbia University Medical Center, New York, NY
| | - Alessandro Giardini
- Cardiorespiratory Unit, Great Ormond Street Hospital, London, United Kingdom (A.G.)
| | - Elizabeth Goldmuntz
- Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA (E.G.)
| | - Jonathan R. Kaltman
- Heart Development and Structural Diseases Branch, Division of Cardiovascular Sciences, National Institute of Heart, Lung, and Blood, National Institutes of Health, Bethesda, MD (J.R.K.)
| | - Richard Kim
- Department of Cardiac Surgery, Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA (R.K.)
| | - Jane W. Newburger
- Department of Cardiology (J.W.N.), Boston Children’s Hospital, MA
- Department of Cardiology (J.W.N.), Boston Children’s Hospital, MA
| | - Yufeng Shen
- Systems Biology (Y.S.), Columbia University Medical Center, New York, NY
- Biomedical Informatics (Y.S.), Columbia University Medical Center, New York, NY
| | - Deepak Srivastava
- Gladstone Institute of Cardiovascular Disease, San Francisco, CA (D.S.)
| | - Martin Tristani-Firouzi
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT (M.T.-F.)
| | - Bruce D. Gelb
- Mindich Child Health and Development Institute (B.D.G.), Icahn School of Medicine at Mount Sinai, New York
- Department of Pediatrics (B.D.G.), Icahn School of Medicine at Mount Sinai, New York
- Department of Genetics (B.D.G.), Icahn School of Medicine at Mount Sinai, New York
- Department of Genomic Sciences (B.D. co-occurrence G.), Icahn School of Medicine at Mount Sinai, New York
| | - George A. Porter
- Department of Pediatrics, University of Rochester Medical Center, NY (G.A.P.)
| | - Christine E. Seidman
- Departments of Genetics (M.Y.J., P.N.P., A.C.P., J.A.L.W., A.H., A.C.T., S.U.M., J.M.G., D.M.M., S.R.D., C.E.S., J.G.S.), Harvard Medical School, Boston, MA
- Division of Cardiology (S.R.D., C.E.S.), Brigham and Women’s Hospital, Boston, MA
- Howard Hughes Medical Institute, Chevy Chase, MD (C.E.S.)
| | - Jonathan G. Seidman
- Departments of Genetics (M.Y.J., P.N.P., A.C.P., J.A.L.W., A.H., A.C.T., S.U.M., J.M.G., D.M.M., S.R.D., C.E.S., J.G.S.), Harvard Medical School, Boston, MA
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Martin-Trujillo A, Patel N, Richter F, Jadhav B, Garg P, Morton SU, McKean DM, DePalma SR, Goldmuntz E, Gruber D, Kim R, Newburger JW, Porter GA, Giardini A, Bernstein D, Tristani-Firouzi M, Seidman JG, Seidman CE, Chung WK, Gelb BD, Sharp AJ. Rare genetic variation at transcription factor binding sites modulates local DNA methylation profiles. PLoS Genet 2020; 16:e1009189. [PMID: 33216750 PMCID: PMC7679001 DOI: 10.1371/journal.pgen.1009189] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 10/11/2020] [Indexed: 12/20/2022] Open
Abstract
Although DNA methylation is the best characterized epigenetic mark, the mechanism by which it is targeted to specific regions in the genome remains unclear. Recent studies have revealed that local DNA methylation profiles might be dictated by cis-regulatory DNA sequences that mainly operate via DNA-binding factors. Consistent with this finding, we have recently shown that disruption of CTCF-binding sites by rare single nucleotide variants (SNVs) can underlie cis-linked DNA methylation changes in patients with congenital anomalies. These data raise the hypothesis that rare genetic variation at transcription factor binding sites (TFBSs) might contribute to local DNA methylation patterning. In this work, by combining blood genome-wide DNA methylation profiles, whole genome sequencing-derived SNVs from 247 unrelated individuals along with 133 predicted TFBS motifs derived from ENCODE ChIP-Seq data, we observed an association between the disruption of binding sites for multiple TFs by rare SNVs and extreme DNA methylation values at both local and, to a lesser extent, distant CpGs. While the majority of these changes affected only single CpGs, 24% were associated with multiple outlier CpGs within ±1kb of the disrupted TFBS. Interestingly, disruption of functionally constrained sites within TF motifs lead to larger DNA methylation changes at nearby CpG sites. Altogether, these findings suggest that rare SNVs at TFBS negatively influence TF-DNA binding, which can lead to an altered local DNA methylation profile. Furthermore, subsequent integration of DNA methylation and RNA-Seq profiles from cardiac tissues enabled us to observe an association between rare SNV-directed DNA methylation and outlier expression of nearby genes. In conclusion, our findings not only provide insights into the effect of rare genetic variation at TFBS on shaping local DNA methylation and its consequences on genome regulation, but also provide a rationale to incorporate DNA methylation data to interpret the functional role of rare variants. One of the major challenges for human genetics in the post-genomic era is to interpret the functional relevance of genetic variation. Quantitative trait locus (QTL) analyses have associated an important fraction of genetic variants with a wide range of molecular phenotypes including gene expression (eQTL) and DNA methylation (meQTL), providing insights into the mechanisms by which genetic variation can contribute to health and disease. Although QTL mapping represents an excellent approach to identify biologically relevant functional variants, these studies have been mainly focused on common variants and do not include low-frequency and rare variants. Here, we observed that rare regulatory variants, i.e, single nucleotide variants (SNVs) that disrupt transcription factor binding sites (TFBSs), are associated with changes in DNA methylation at both local and, to a lesser extent, broader locations, most likely, by altering the DNA-binding affinity of transcription factors (TFs). Interestingly, we have also shown that this change in DNA methylation can alter expression levels of nearby genes. Overall, these data suggest a role of rare regulatory SNVs in shaping DNA methylation, and suggest that the incorporation of DNA methylation data may help to interpret the functional consequences of human genetic variation.
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Affiliation(s)
- Alejandro Martin-Trujillo
- The Mindich Child Health and Development Institute and Department of Genetics & Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Nihir Patel
- The Mindich Child Health and Development Institute and Department of Genetics & Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Felix Richter
- The Mindich Child Health and Development Institute and Department of Genetics & Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Bharati Jadhav
- The Mindich Child Health and Development Institute and Department of Genetics & Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Paras Garg
- The Mindich Child Health and Development Institute and Department of Genetics & Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Sarah U. Morton
- Department of Newborn Medicine, Boston Children’s Hospital, Boston, Massachusetts, United States of America
| | - David M. McKean
- Division of Cardiovascular Medicine, Brigham and Women’s Hospital, Boston, Massachusetts, United States of America
| | - Steven R. DePalma
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America
- Howard Hughes Medical Institute, Harvard University, Boston, Massachusetts, United States of America
| | - Elizabeth Goldmuntz
- Division of Cardiology, Children’s Hospital of Philadelphia, Philadelphia, PA, United States of America
- Department of Pediatrics, University of Pennsylvania Perlman School of Medicine, Philadelphia, PA, United States of America
| | - Dorota Gruber
- Department of Pediatrics, Cohen Children’s Medical Center, Northwell Health, New Hyde Park, NY, Unites States of America
| | - Richard Kim
- Department of Pediatrics, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Jane W. Newburger
- Department of Cardiology, Boston Children's Hospital, Boston, Massachusetts, United States of America
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - George A. Porter
- Department of Pediatrics, University of Rochester Medical Center, Rochester, NY, United States of America
| | | | - Daniel Bernstein
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, United States of America
| | - Martin Tristani-Firouzi
- Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT, United States of America
| | - Jonathan G. Seidman
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Christine E. Seidman
- Division of Cardiovascular Medicine, Brigham and Women’s Hospital, Boston, Massachusetts, United States of America
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America
- Howard Hughes Medical Institute, Harvard University, Boston, Massachusetts, United States of America
| | - Wendy K. Chung
- Departments of Pediatrics and Medicine, Columbia University, New York, NY, United States of America
| | - Bruce D. Gelb
- The Mindich Child Health and Development Institute and Department of Genetics & Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, United States of America
| | - Andrew J. Sharp
- The Mindich Child Health and Development Institute and Department of Genetics & Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- * E-mail:
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3
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Jang MY, Tai AC, Patel PN, Ito K, Gorham J, Pereira AC, McKean DM, Seidman CE, Seidman JG. Abstract 467: Identification of Novel Pathogenic Mutations in Non-Canonical RNA Splice Sites in Congenital Heart Disease. Circ Res 2019. [DOI: 10.1161/res.125.suppl_1.467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Rationale:
Congenital heart disease (CHD) occurs in about 1 in 100 live births, yet known genetic causes explain less than 20% of CHD cases. While variants that cause frameshift, nonsense, start/stop site gain or loss, and canonical splice site alterations are readily categorized as being pathogenic or loss-of-function (LOF), interpreting the clinical significance of variants without obvious functional consequences remains challenging. Here, we aim to improve classification of variants of unknown significance (VUS) in non-canonical RNA splice sites that may be pathogenic for CHD.
Methods:
We tested candidate LOF
de novo
(DNV) and rare (p < 2E-5) inherited variants from whole exome sequencing of 4474 CHD probands and their parents in the NHLBI Pediatric Cardiac Genetics Consortium. Briefly, variants underwent computational selection to prioritize VUS in splice regions that are likely to alter splicing (“high-likelihood VUS”). These variants then underwent
in vitro
analysis including Minigene construction, transfection, RNA isolation, and sequencing to confirm splicing outcomes.
Results:
Preliminary results limited to DNV variants showed that 163 of 2678 (6.08%) were high-likelihood VUS. Subsequent analysis
in vitro
assay of high-likelihood VUS yielded 53 as splice-altering (p < 0.05) and thus LOF. Combined with previously identified 366 DNV LOF variants, the addition of these splice-altering variants represents a 15.3% increase in total LOF DNV variant calls. This includes new pathogenic mutations in known CHD genes such as
KMT2D
. In one case, a CHD proband with features of Kabuki Syndrome without a definitive diagnosis was found to have a splice-altering variant in
KMT2D
. We have extended this assay to 34518 rare, inherited variants in the same cohort, of which 868 (2.54%) are in genes previously associated with CHD.
Conclusion:
Consideration of non-canonical RNA splice sites in this assay increased the yield of LOF mutations from traditional sequencing methods by 15.3% in the CHD cohort. Further analysis of splice-altering variants in both known and unknown pathogenic genes will improve diagnostic classification of VUS and gene-based diagnosis of CHD.
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McKean DM, Homsy J, Wakimoto H, Patel N, Gorham J, DePalma SR, Ware JS, Zaidi S, Ma W, Patel N, Lifton RP, Chung WK, Kim R, Shen Y, Brueckner M, Goldmuntz E, Sharp AJ, Seidman CE, Gelb BD, Seidman JG. Loss of RNA expression and allele-specific expression associated with congenital heart disease. Nat Commun 2016; 7:12824. [PMID: 27670201 PMCID: PMC5052634 DOI: 10.1038/ncomms12824] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 08/04/2016] [Indexed: 12/22/2022] Open
Abstract
Congenital heart disease (CHD), a prevalent birth defect occurring in 1% of newborns, likely results from aberrant expression of cardiac developmental genes. Mutations in a variety of cardiac transcription factors, developmental signalling molecules and molecules that modify chromatin cause at least 20% of disease, but most CHD remains unexplained. We employ RNAseq analyses to assess allele-specific expression (ASE) and biallelic loss-of-expression (LOE) in 172 tissue samples from 144 surgically repaired CHD subjects. Here we show that only 5% of known imprinted genes with paternal allele silencing are monoallelic versus 56% with paternal allele expression-this cardiac-specific phenomenon seems unrelated to CHD. Further, compared with control subjects, CHD subjects have a significant burden of both LOE genes and ASE events associated with altered gene expression. These studies identify FGFBP2, LBH, RBFOX2, SGSM1 and ZBTB16 as candidate CHD genes because of significantly altered transcriptional expression.
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Affiliation(s)
- David M McKean
- Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA.,Cardiovascular Division, Brigham and Women's Hospital, Harvard University, Boston, Massachusetts 02115, USA
| | - Jason Homsy
- Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA.,Cardiovascular Division, Brigham and Women's Hospital, Harvard University, Boston, Massachusetts 02115, USA.,Cardiovascular Research Center, Massachusetts General Hospital, Boston, Massachusetts 02114, USA
| | - Hiroko Wakimoto
- Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Neil Patel
- The Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Joshua Gorham
- Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Steven R DePalma
- Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA.,Howard Hughes Medical Institute, Harvard University, Boston, Massachusetts 02115, USA
| | - James S Ware
- Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA.,National Institute for Health Research Cardiovascular Biomedical Research Unit at Royal Brompton and Harefield National Health Service Foundation Trust and Imperial College London, London SW3 6NP, UK.,National Heart and Lung Institute, Imperial College London, London SW3 6NP, UK
| | - Samir Zaidi
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA
| | - Wenji Ma
- Department of Systems Biology, Columbia University Medical Center, New York, New York 10032, USA
| | - Nihir Patel
- The Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Richard P Lifton
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA.,Howard Hughes Medical Institute, Yale University, Connecticut 06510, USA
| | - Wendy K Chung
- Department of Pediatrics and Medicine, Columbia University Medical Center, New York, New York 10032, USA
| | - Richard Kim
- Section of Cardiothoracic Surgery, University of Southern California Keck School of Medicine, Los Angeles, California 90089, USA
| | - Yufeng Shen
- Department of Systems Biology, Columbia University Medical Center, New York, New York 10032, USA.,Department of Biomedical Informatics, Columbia University Medical Center, New York, New York 10032, USA
| | - Martina Brueckner
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA
| | - Elizabeth Goldmuntz
- Department of Pediatrics, The Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Andrew J Sharp
- The Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA.,Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Christine E Seidman
- Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA.,Cardiovascular Division, Brigham and Women's Hospital, Harvard University, Boston, Massachusetts 02115, USA.,Howard Hughes Medical Institute, Harvard University, Boston, Massachusetts 02115, USA
| | - Bruce D Gelb
- The Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA.,Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA.,Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - J G Seidman
- Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA
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Christodoulou DC, Wakimoto H, Onoue K, Eminaga S, Gorham JM, DePalma SR, Herman DS, Teekakirikul P, Conner DA, McKean DM, Domenighetti AA, Aboukhalil A, Chang S, Srivastava G, McDonough B, De Jager PL, Chen J, Bulyk ML, Muehlschlegel JD, Seidman CE, Seidman JG. 5'RNA-Seq identifies Fhl1 as a genetic modifier in cardiomyopathy. J Clin Invest 2014; 124:1364-70. [PMID: 24509080 DOI: 10.1172/jci70108] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Accepted: 11/27/2013] [Indexed: 11/17/2022] Open
Abstract
The transcriptome is subject to multiple changes during pathogenesis, including the use of alternate 5' start-sites that can affect transcription levels and output. Current RNA sequencing techniques can assess mRNA levels, but do not robustly detect changes in 5' start-site use. Here, we developed a transcriptome sequencing strategy that detects genome-wide changes in start-site usage (5'RNA-Seq) and applied this methodology to identify regulatory events that occur in hypertrophic cardiomyopathy (HCM). Compared with transcripts from WT mice, 92 genes had altered start-site usage in a mouse model of HCM, including four-and-a-half LIM domains protein 1 (Fhl1). HCM-induced altered transcriptional regulation of Fhl1 resulted in robust myocyte expression of a distinct protein isoform, a response that was conserved in humans with genetic or acquired cardiomyopathies. Genetic ablation of Fhl1 in HCM mice was deleterious, which suggests that Fhl1 transcriptional changes provide salutary effects on stressed myocytes in this disease. Because Fhl1 is a chromosome X-encoded gene, stress-induced changes in its transcription may contribute to gender differences in the clinical severity of HCM. Our findings indicate that 5'RNA-Seq has the potential to identify genome-wide changes in 5' start-site usage that are associated with pathogenic phenotypes.
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McKean DM, Niswander L. Defects in GPI biosynthesis perturb Cripto signaling during forebrain development in two new mouse models of holoprosencephaly. Biol Open 2012; 1:874-83. [PMID: 23213481 PMCID: PMC3507239 DOI: 10.1242/bio.20121982] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Accepted: 06/06/2012] [Indexed: 11/20/2022] Open
Abstract
Holoprosencephaly is the most common forebrain defect in humans. We describe two novel mouse mutants that display a holoprosencephaly-like phenotype. Both mutations disrupt genes in the glycerophosphatidyl inositol (GPI) biosynthesis pathway: gonzo disrupts Pign and beaker disrupts Pgap1. GPI anchors normally target and anchor a diverse group of proteins to lipid raft domains. Mechanistically we show that GPI anchored proteins are mislocalized in GPI biosynthesis mutants. Disruption of the GPI-anchored protein Cripto (mouse) and TDGF1 (human ortholog) have been shown to result in holoprosencephaly, leading to our hypothesis that Cripto is the key GPI anchored protein whose altered function results in an HPE-like phenotype. Cripto is an obligate Nodal co-factor involved in TGFβ signaling, and we show that TGFβ signaling is reduced both in vitro and in vivo. This work demonstrates the importance of the GPI anchor in normal forebrain development and suggests that GPI biosynthesis genes should be screened for association with human holoprosencephaly.
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Affiliation(s)
- David M McKean
- HHMI, Department of Pediatrics, Cell Biology, Stem Cells and Development Graduate Program, and Children's Hospital Colorado, University of Colorado Anschutz Medical Campus Aurora , CO 80045 , USA
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7
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Mao J, McKean DM, Warrier S, Corbin JG, Niswander L, Zohn IE. The iron exporter ferroportin 1 is essential for development of the mouse embryo, forebrain patterning and neural tube closure. Development 2010; 137:3079-88. [PMID: 20702562 DOI: 10.1242/dev.048744] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Neural tube defects (NTDs) are some of the most common birth defects observed in humans. The incidence of NTDs can be reduced by peri-conceptional folic acid supplementation alone and reduced even further by supplementation with folic acid plus a multivitamin. Here, we present evidence that iron maybe an important nutrient necessary for normal development of the neural tube. Following implantation of the mouse embryo, ferroportin 1 (Fpn1) is essential for the transport of iron from the mother to the fetus and is expressed in the visceral endoderm, yolk sac and placenta. The flatiron (ffe) mutant mouse line harbors a hypomorphic mutation in Fpn1 and we have created an allelic series of Fpn1 mutations that result in graded developmental defects. A null mutation in the Fpn1 gene is embryonic lethal before gastrulation, hypomorphic Fpn1(ffe/ffe) mutants exhibit NTDs consisting of exencephaly, spina bifida and forebrain truncations, while Fpn1(ffe/KI) mutants exhibit even more severe NTDs. We show that Fpn1 is not required in the embryo proper but rather in the extra-embryonic visceral endoderm. Our data indicate that loss of Fpn1 results in abnormal morphogenesis of the anterior visceral endoderm (AVE). Defects in the development of the forebrain in Fpn1 mutants are compounded by defects in multiple signaling centers required for maintenance of the forebrain, including the anterior definitive endoderm (ADE), anterior mesendoderm (AME) and anterior neural ridge (ANR). Finally, we demonstrate that this loss of forebrain maintenance is due in part to the iron deficiency that results from the absence of fully functional Fpn1.
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Affiliation(s)
- Jinzhe Mao
- Center for Neuroscience Research, Children's Research Institute, Children's National Medical Center, Washington, DC 20010, USA
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McKean DM, Niswander L. Cripto links GPI biosynthesis and TGFb signaling in forebrain development. Dev Biol 2009. [DOI: 10.1016/j.ydbio.2009.05.151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Ihida-Stansbury K, McKean DM, Lane KB, Loyd JE, Wheeler LA, Morrell NW, Jones PL. Tenascin-C is induced by mutated BMP type II receptors in familial forms of pulmonary arterial hypertension. Am J Physiol Lung Cell Mol Physiol 2006; 291:L694-702. [PMID: 16782755 DOI: 10.1152/ajplung.00119.2006] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Familial forms of human pulmonary arterial hypertension (FPAH) have been linked to mutations in bone morphogenetic protein (BMP) type II receptors (BMPR2s), yet the downstream targets of these receptors remain obscure. Here we show that pulmonary vascular lesions from patients harboring BMPR2 mutations express high levels of tenascin-C (TN-C), an extracellular matrix glycoprotein that promotes pulmonary artery (PA) smooth muscle cell (SMC) proliferation. To begin to define how TN-C is regulated, PA SMCs were cultured from normal subjects and from those with FPAH due to BMPR2 mutations. FPAH SMCs expressed higher levels of TN-C than normal SMCs. Similarly, expression of Prx1, a factor that drives TN-C transcription, was elevated in FPAH vascular lesions and SMCs derived thereof. Furthermore, Prx1 and TN-C promoter activities were significantly higher in FPAH vs. normal SMCs. To delineate how BMPR2s control TN-C, we focused on receptor (R)-Smads, downstream effectors activated by wild-type BMPR2s. Nuclear localization and phosphorylation of R-Smads was greater in normal vs. FPAH SMCs. As well, indirect blockade of R-Smad signaling with a kinase-deficient BMP receptor Ib upregulated TN-C in normal SMCs. Because ERK1/2 MAPKs inhibit the transcriptional activity of R-Smads, and because ERK1/2 promotes TN-C transcription, we determined whether ERK1/2 inhibits R-Smad signaling in FPAH SMCs and whether this activity is required for TN-C transcription. Indeed, ERK1/2 activity was greater in FPAH SMCs, and inhibition of ERK1/2 resulted in nuclear localization of R-Smads and inhibition of TN-C. These studies define a novel signaling network relevant to PAH underscored by BMPR2 mutations.
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Affiliation(s)
- Kaori Ihida-Stansbury
- University of Pennsylvania, Institute for Medicine & Engineering, Department of Pathology and Laboratory Medicine, Philadelphia, PA 19104-6383, USA
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Ihida-Stansbury K, McKean DM, Gebb SA, Martin JF, Stevens T, Nemenoff R, Vaughn J, Lane K, Loyd J, Wheeler L, Morrell NW, Ivy D, Jones PL. Regulation and functions of the paired-related homeobox gene PRX1 in pulmonary vascular development and disease. Chest 2006; 128:591S. [PMID: 16373852 DOI: 10.1378/chest.128.6_suppl.591s] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Affiliation(s)
- K Ihida-Stansbury
- Department of Pediatrics, University of Colorado Health Sciences Center, Denver, CO, USA
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Ihida-Stansbury K, McKean DM, Gebb SA, Martin JF, Stevens T, Nemenoff R, Akeson A, Vaughn J, Jones PL. Paired-related homeobox gene Prx1 is required for pulmonary vascular development. Circ Res 2004; 94:1507-14. [PMID: 15117820 DOI: 10.1161/01.res.0000130656.72424.20] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Herein, we show that the paired-related homeobox gene, Prx1, is required for lung vascularization. Initial studies revealed that Prx1 localizes to differentiating endothelial cells (ECs) within the fetal lung mesenchyme, and later within ECs forming vascular networks. To begin to determine whether Prx1 promotes EC differentiation, fetal lung mesodermal cells were transfected with full-length Prx1 cDNA, resulting in their morphological transformation to an endothelial-like phenotype. In addition, Prx1-transformed cells acquired the ability to form vascular networks on Matrigel. Thus, Prx1 might function by promoting pulmonary EC differentiation within the fetal lung mesoderm, as well as their subsequent incorporation into vascular networks. To understand how Prx1 participates in network formation, we focused on tenascin-C (TN-C), an extracellular matrix (ECM) protein induced by Prx1. Immunocytochemistry/histochemistry showed that a TN-C-rich ECM surrounds Prx1-positive pulmonary vascular networks both in vivo and in tissue culture. Furthermore, antibody-blocking studies showed that TN-C is required for Prx1-dependent vascular network formation on Matrigel. Finally, to determine whether these results were relevant in vivo, we examined newborn Prx1-wild-type (+/+) and Prx1-null (-/-) mice and showed that Prx1 is critical for expression of TN-C and lung vascularization. These studies provide a framework to understand how Prx1 controls EC differentiation and their subsequent incorporation into functional pulmonary vascular networks.
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Affiliation(s)
- Kaori Ihida-Stansbury
- Department of Pediatrics, University of Colorado Health Sciences Center, Denver, CO 80262, USA
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McKean DM, Sisbarro L, Ilic D, Kaplan-Alburquerque N, Nemenoff R, Weiser-Evans M, Kern MJ, Jones PL. FAK induces expression of Prx1 to promote tenascin-C-dependent fibroblast migration. J Cell Biol 2003; 161:393-402. [PMID: 12741393 PMCID: PMC2172901 DOI: 10.1083/jcb.jcb.200302126] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Fibroblast migration depends, in part, on activation of FAK and cellular interactions with tenascin-C (TN-C). Consistent with the idea that FAK regulates TN-C, migration-defective FAK-null cells expressed reduced levels of TN-C. Furthermore, expression of FAK in FAK-null fibroblasts induced TN-C, whereas inhibition of FAK activity in FAK-wild-type cells had the opposite effect. Paired-related homeobox 1 (Prx1) encodes a homeobox transcription factor that induces TN-C by interacting with a binding site within the TN-C promoter, and it also promotes fibroblast migration. Therefore, we hypothesized that FAK regulates TN-C by controlling the DNA-binding activity of Prx1 and/or by inducing Prx1 expression. Prx1-homeodomain binding site complex formation observed with FAK-wild-type fibroblasts failed to occur in FAK-null fibroblasts, yet expression of Prx1 in these cells induced TN-C promoter activity. Thus, FAK is not essential for Prx1 DNA-binding activity. However, activated FAK was essential for Prx1 expression. Functionally, Prx1 expression in FAK-null fibroblasts restored their ability to migrate toward fibronectin, in a manner that depends on TN-C. These results appear to be relevant in vivo because Prx1 and TN-C expression levels were reduced in FAK-null embryos. This paper suggests a model whereby FAK induces Prx1, and subsequently the formation of a TN-C-enriched ECM that contributes to fibroblast migration.
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Affiliation(s)
- David M McKean
- Department of Pediatrics, University of Colorado Health Sciences Center, Denver, CO 80262, USA
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Jones FS, McKean DM, Meech R, Edelman DB, Oakey RJ, Jones PL. Regulation of Vascular Smooth Muscle Cell Growth and Adhesion by Paired-Related Homeobox Genes. Chest 2002. [DOI: 10.1016/s0012-3692(15)35496-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Jones FS, McKean DM, Meech R, Edelman DB, Oakey RJ, Jones PL. Regulation of vascular smooth muscle cell growth and adhesion by paired-related homeobox genes. Chest 2002; 121:89S-90S. [PMID: 11893718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023] Open
Affiliation(s)
- Frederick S Jones
- Department of Neurobiology, The Scripps Research Institute, La Jolla, CA, USA
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