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Aono‐Setoguchi H, Yagi H, Akiyama N, Takeda N, Ando M, Yamauchi H, Komuro I, Takeda N. Management of an elderly patient with nonsyndromic TGFBR1-related aortopathy: A case report. Clin Case Rep 2024; 12:e9317. [PMID: 39130808 PMCID: PMC11310403 DOI: 10.1002/ccr3.9317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Revised: 07/09/2024] [Accepted: 07/19/2024] [Indexed: 08/13/2024] Open
Abstract
Key Clinical Message Genetic variants associated with hereditary TAAD may contribute to nonsyndromic TAAD. We present the case of a 72-year-old man with nonsyndromic TAAD undergoing prophylactic surgery after a gene panel test revealed a pathogenic variant in TGFBR1, but the indication for genetic testing in such elderly-onset cases still warrants further discussion. Abstract Hereditary thoracic aortic aneurysm and dissection (TAAD) is a serious clinical condition resulting in a fatal outcome. Recently, variants in causative genes for syndromic hereditary TAAD, such as Marfan syndrome and Loeys-Dietz syndrome (LDS), have been reported to predispose to the development of nonsyndromic TAAD; however, genetic testing for patients with elderly-onset nonsyndromic TAAD warrants further discussion. We present a 72-year-old nonsyndromic Japanese man with moderate-sized aortic annulus ectasia (AAE) with moderate aortic regurgitation and ascending to distal arch aortic dilatation (maximum diameter: 46 mm). He had been treated for hypertension and dyslipidemia for 7 years, and his eldest son had AAE at 33 years old and type A aortic dissection at 43 years old. Surgical repair was considered a treatment option because the patient potentially had a nonsyndromic hereditary aortic disease, and genetic panel testing for TAAD identified a pathogenic missense variant in TGFBR1 (c.934G > A, p.[Gly312Ser]), previously reported in patients with LDS type 1. He was diagnosed with nonsyndromic TGFBR1-related aortopathy and underwent prophylactic surgery using a modified Bentall operation and total arch replacement with open stent graft implantation. Genetic testing was useful in guiding the treatment strategy, but further analysis is warranted to establish the clinical value in the treatment plan for patients with elderly-onset nonsyndromic TAAD.
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Affiliation(s)
- Hitomi Aono‐Setoguchi
- Department of Cardiovascular Medicine, Graduate School of MedicineUniversity of TokyoTokyoJapan
| | - Hiroki Yagi
- Department of Cardiovascular Medicine, Graduate School of MedicineUniversity of TokyoTokyoJapan
- Marfan Syndrome CenterUniversity of Tokyo HospitalTokyoJapan
| | - Nana Akiyama
- Marfan Syndrome CenterUniversity of Tokyo HospitalTokyoJapan
- Department of Genomic MedicineUniversity of Tokyo HospitalTokyoJapan
| | - Norifumi Takeda
- Department of Cardiovascular Medicine, Graduate School of MedicineUniversity of TokyoTokyoJapan
- Marfan Syndrome CenterUniversity of Tokyo HospitalTokyoJapan
| | - Masahiko Ando
- Marfan Syndrome CenterUniversity of Tokyo HospitalTokyoJapan
- Department of Cardiovascular SurgeryUniversity of Tokyo HospitalTokyoJapan
| | - Haruo Yamauchi
- Marfan Syndrome CenterUniversity of Tokyo HospitalTokyoJapan
- Department of Cardiovascular SurgeryUniversity of Tokyo HospitalTokyoJapan
| | - Issei Komuro
- Department of Frontier Cardiovascular Science, Graduate School of MedicineUniversity of TokyoTokyoJapan
- International University of Health and WelfareTokyoJapan
| | - Norihiko Takeda
- Department of Cardiovascular Medicine, Graduate School of MedicineUniversity of TokyoTokyoJapan
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Ishii S, Fujiwara T, Yagi H, Takeda N, Ando M, Yamauchi H, Inuzuka R, Taniguchi Y, Hatano M, Komuro I. A novel pathogenic variant located just upstream of the C-terminal Ser423-X-Ser425 phosphorylation motif in SMAD3 causing Loeys-Dietz syndrome. Mol Genet Genomic Med 2023; 11:e2257. [PMID: 37864304 PMCID: PMC10724497 DOI: 10.1002/mgg3.2257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 04/21/2023] [Accepted: 07/14/2023] [Indexed: 10/22/2023] Open
Abstract
OBJECTIVE Loeys-Dietz syndrome (LDS) is a heritable disorder of connective tissue closely related to Marfan syndrome (MFS). LDS is caused by loss-of-function variants of genes that encode components of transforming growth factor-β (TGF-β) signaling; nevertheless, LDS type 1/2 caused by TGFBR1/2 pathogenic variants is frequently found to have paradoxical increases in TGF-β signaling in the aneurysmal aortic wall. Here, we present a Japanese LDS family having a novel SMAD3 variant. METHODS The proband was tested via clinical, genetic, and histological analyses. In vitro analysis was performed for pathogenic evaluation. RESULTS The novel heterozygous missense variant of SMAD3 [c.1262G>A, p.(Cys421Tyr)], located just upstream of the C-terminal Ser423-X-Ser425 phosphorylation motif, was found in this instance of LDS type 3. This variant led to reduced phospho-SMAD3 (Ser423/Ser425) levels and transcription activity in vitro; however, a paradoxical upregulation of TGF-β signaling was evident in the aortic wall. CONCLUSIONS Our results revealed the presence of TGF-β paradox in this case with the novel loss-of-function SMAD3 variant. The precise mechanism underlying the paradox is unknown, but further research is warranted to clarify the influence of the SMAD3 variant type and location on the LDS3 phenotype as well as the molecular mechanism leading to LDS3 aortopathy.
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Affiliation(s)
- Satoshi Ishii
- Department of Cardiovascular MedicineThe University of Tokyo HospitalTokyoJapan
| | - Takayuki Fujiwara
- Department of Cardiovascular MedicineThe University of Tokyo HospitalTokyoJapan
- Department of Computational Diagnostic Radiology and Preventive MedicineThe University of Tokyo HospitalTokyoJapan
| | - Hiroki Yagi
- Department of Cardiovascular MedicineThe University of Tokyo HospitalTokyoJapan
- Marfan Syndrome CenterThe University of Tokyo HospitalTokyoJapan
| | - Norifumi Takeda
- Department of Cardiovascular MedicineThe University of Tokyo HospitalTokyoJapan
- Marfan Syndrome CenterThe University of Tokyo HospitalTokyoJapan
| | - Masahiko Ando
- Marfan Syndrome CenterThe University of Tokyo HospitalTokyoJapan
- Department of Cardiac SurgeryThe University of Tokyo HospitalTokyoJapan
| | - Haruo Yamauchi
- Marfan Syndrome CenterThe University of Tokyo HospitalTokyoJapan
- Department of Cardiac SurgeryThe University of Tokyo HospitalTokyoJapan
| | - Ryo Inuzuka
- Marfan Syndrome CenterThe University of Tokyo HospitalTokyoJapan
- Department of PediatricsThe University of Tokyo HospitalTokyoJapan
| | - Yuki Taniguchi
- Marfan Syndrome CenterThe University of Tokyo HospitalTokyoJapan
- Department of Orthopedic SurgeryThe University of Tokyo HospitalTokyoJapan
| | - Masaru Hatano
- Department of Cardiovascular MedicineThe University of Tokyo HospitalTokyoJapan
- Department of Advanced Medical Center for Heart FailureThe University of Tokyo HospitalTokyoJapan
| | - Issei Komuro
- Department of Cardiovascular MedicineThe University of Tokyo HospitalTokyoJapan
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3
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Lin W, Xiong J, Jiang Y, Liu H, Bian J, Wang J, Shao Y, Ni B. Fibrillin-1 mutation contributes to Marfan syndrome by inhibiting Cav1.2-mediated cell proliferation in vascular smooth muscle cells. Channels (Austin) 2023; 17:2192377. [PMID: 36972239 PMCID: PMC10054150 DOI: 10.1080/19336950.2023.2192377] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Accepted: 03/14/2023] [Indexed: 03/29/2023] Open
Abstract
Marfan syndrome (MFS) is an autosomal dominant connective tissue disorder caused by mutation in fibrillin-1 (FBN1). However, the molecular mechanism underlying MFS remains poorly understood. The study aimed to explore how the L-type calcium channel (CaV1.2) modulates disease progression of MFS and to identify a potential effective target for attenuating MFS. KEGG enrichment analysis showed that the calcium signaling pathway gene set was significantly enriched. We demonstrated that FBN1 deficiency exhibited inhibition on both the expression of Cav1.2 and proliferation of vascular smooth muscle cells (VSMCs). Then, we examined whether FBN1 mediates Cav1.2 via regulating TGF-β1. Higher levels of TGF-β1 were observed in the serum and aortic tissues from patients with MFS. TGF-β1 modulated Cav1.2 expression in a concentration-dependent manner. We evaluated the role of Cav1.2 in MFS by small interfering RNA and Cav1.2 agonist Bay K8644. The effect of Cav1.2 on cell proliferation was dependent on c-Fos activity. These results demonstrated FBN1 deficiency decreased the expression levels of Cav1.2 via regulation of TGF-β1, and downregulation of Cav1.2 inhibited cell proliferation of human aortic smooth muscle cells (HASMCs) in MFS patients. These findings suggest that Cav1.2 may be an appealing therapeutic target for MFS.
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Affiliation(s)
- Wenfeng Lin
- Department of Cardiovascular Surgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Jiaqi Xiong
- Department of Cardiovascular Surgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Yefan Jiang
- Department of Cardiovascular Surgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Hao Liu
- Department of Cardiovascular Surgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Jinhui Bian
- Department of Cardiovascular Surgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Juejin Wang
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Yongfeng Shao
- Department of Cardiovascular Surgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Buqing Ni
- Department of Cardiovascular Surgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
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4
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Alaamery M, Albesher N, Alhabshan F, Barnett P, Salim Kabbani M, Chaikhouni F, Ilgun A, Mook ORF, Alsaif H, Christoffels VM, van Tintelen P, Wilde AAM, Houweling AC, Massadeh S, Postma AV. TGFBR1 Variants Can Associate with Non-Syndromic Congenital Heart Disease without Aortopathy. J Cardiovasc Dev Dis 2023; 10:455. [PMID: 37998513 PMCID: PMC10672196 DOI: 10.3390/jcdd10110455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 10/31/2023] [Accepted: 11/04/2023] [Indexed: 11/25/2023] Open
Abstract
BACKGROUND Congenital heart diseases (CHD) are the most common congenital malformations in newborns and remain the leading cause of mortality among infants under one year old. Molecular diagnosis is crucial to evaluate the recurrence risk and to address future prenatal diagnosis. Here, we describe two families with various forms of inherited non-syndromic CHD and the genetic work-up and resultant findings. METHODS Next-generation sequencing (NGS) was employed in both families to uncover the genetic cause. In addition, we performed functional analysis to investigate the consequences of the identified variants in vitro. RESULTS NGS identified possible causative variants in both families in the protein kinase domain of the TGFBR1 gene. These variants occurred on the same amino acid, but resulted in differently substituted amino acids (p.R398C/p.R398H). Both variants co-segregate with the disease, are extremely rare or unique, and occur in an evolutionary highly conserved domain of the protein. Furthermore, both variants demonstrated a significantly altered TGFBR1-smad signaling activity. Clinical investigation revealed that none of the carriers had (signs of) aortopathy. CONCLUSION In conclusion, we describe two families, with various forms of inherited non-syndromic CHD without aortopathies, associated with unique/rare variants in TGFBR1 that display altered TGF-beta signaling. These findings highlight involvement of TGFBR1 in CHD, and warrant consideration of potential causative TGFBR1 variants also in CHD patients without aortopathies.
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Affiliation(s)
- Manal Alaamery
- Developmental Medicine Department, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, King Abdulaziz Medical City, Ministry of National Guard—Health Affairs, Riyadh 11481, Saudi Arabia
- Saudi Genome Program, National Centre for Genomic Technologies, King Abdulaziz City for Science and Technology (KACST), Riyadh 11442, Saudi Arabia
- KACST-BWH Centre of Excellence for Biomedicine, Joint Centres of Excellence Program, King Abdulaziz City for Science and Technology (KACST), Riyadh 11442, Saudi Arabia
| | - Nour Albesher
- KACST-BWH Centre of Excellence for Biomedicine, Joint Centres of Excellence Program, King Abdulaziz City for Science and Technology (KACST), Riyadh 11442, Saudi Arabia
- Department of Biological Sciences, Faculty of Sciences, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Fahad Alhabshan
- Department of Cardiac Sciences, Ministry of the National Guard—Health Affairs, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh 11481, Saudi Arabia
| | - Phil Barnett
- Department of Medical Biology, Amsterdam University Medical Centre, 1105 AZ Amsterdam, The Netherlands; (P.B.); (A.I.)
| | - Mohamed Salim Kabbani
- Department of Cardiac Sciences, Ministry of the National Guard—Health Affairs, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh 11481, Saudi Arabia
| | - Farah Chaikhouni
- Department of Cardiac Sciences, Ministry of the National Guard—Health Affairs, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh 11481, Saudi Arabia
| | - Aho Ilgun
- Department of Medical Biology, Amsterdam University Medical Centre, 1105 AZ Amsterdam, The Netherlands; (P.B.); (A.I.)
| | - Olaf R. F. Mook
- Department of Human Genetics, Amsterdam University Medical Centre, 1105 AZ Amsterdam, The Netherlands; (O.R.F.M.); (A.C.H.)
| | - Hessa Alsaif
- KACST-BWH Centre of Excellence for Biomedicine, Joint Centres of Excellence Program, King Abdulaziz City for Science and Technology (KACST), Riyadh 11442, Saudi Arabia
| | - Vincent M. Christoffels
- Department of Medical Biology, Amsterdam University Medical Centre, 1105 AZ Amsterdam, The Netherlands; (P.B.); (A.I.)
| | - Peter van Tintelen
- Department of Genetics, University Medical Center Utrecht, Utrecht University, 3584 CS Utrecht, The Netherlands;
| | - Arthur A. M. Wilde
- Department of Cardiology, Amsterdam University Medical Centre, 1105 AZ Amsterdam, The Netherlands;
| | - Arjan C. Houweling
- Department of Human Genetics, Amsterdam University Medical Centre, 1105 AZ Amsterdam, The Netherlands; (O.R.F.M.); (A.C.H.)
| | - Salam Massadeh
- Developmental Medicine Department, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, King Abdulaziz Medical City, Ministry of National Guard—Health Affairs, Riyadh 11481, Saudi Arabia
- Saudi Genome Program, National Centre for Genomic Technologies, King Abdulaziz City for Science and Technology (KACST), Riyadh 11442, Saudi Arabia
- KACST-BWH Centre of Excellence for Biomedicine, Joint Centres of Excellence Program, King Abdulaziz City for Science and Technology (KACST), Riyadh 11442, Saudi Arabia
| | - Alex V. Postma
- Department of Medical Biology, Amsterdam University Medical Centre, 1105 AZ Amsterdam, The Netherlands; (P.B.); (A.I.)
- Department of Human Genetics, Amsterdam University Medical Centre, 1105 AZ Amsterdam, The Netherlands; (O.R.F.M.); (A.C.H.)
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5
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Starr LJ, Lindsay ME, Lino Cardenas CL, Yetman AT. Siblings with profound connective tissue disease: First report of biallelic TGFBR1-related Loeys-Dietz syndrome. Am J Med Genet A 2023; 191:786-793. [PMID: 36584339 DOI: 10.1002/ajmg.a.63075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 09/21/2022] [Accepted: 09/26/2022] [Indexed: 12/31/2022]
Abstract
Heterozygous missense variants in TGFBR1, encoding one subunit of the transforming growth factor-beta receptor, are a well-established cause of Loeys-Dietz syndrome (LDS)-an autosomal dominant disorder with variable phenotypic expression. Patients with LDS have compromised connective tissues that can result in life-threatening arterial aneurysms, craniosynostosis, characteristic craniofacial and skeletal anomalies, skin translucency, and abnormal wound healing. We report a full sibship with a biallelic type of TGFBR1-related disease. Each born at 38 weeks had aortic root dilation, congenital diaphragmatic hernia (CDH), skin translucency, and profound joint laxity at birth. Both had progressive dilation of the aorta and recurrence of a diaphragmatic defect after plication early in infancy. Patient 1 died at 66 days of age and Patient 2 is alive at 4 years and 4 months of age with multiple morbidities including cystic lung disease complicated by recurrent pneumothoraces and ventilator dependence, craniosynostosis, cervical spine instability, progressive dilation of the aorta, worsening pectus excavatum, large lateral abdominal wall hernia, and diffuse aortic ectasia. Fibroblasts cultured from Patient 2 showed decreased TGF-β responsiveness when compared to control fibroblasts, consistent with previous observations in cells from individuals with autosomal dominant LDS. Whole genome copy number evaluation and sequencing for both patients including their parents as reference revealed compound heterozygous variants of uncertain clinical significance in exon 2 of TGFBR1 (c.239G>A; p.Arg80Gln paternal and c.313C>G; p.His105Asp maternal) in both siblings in trans. Each parent with their respective variant has no apparent medical issues and specifically no LDS characteristics. Neither of these variants have been previously reported. Thousands of patients have been diagnosed with LDS-an established autosomal dominant disease. These siblings represent the first reports of biallelic TGFBR1-related LDS and expand the differential diagnosis of CDH.
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Affiliation(s)
- Lois Janelle Starr
- Department of Pediatrics, Munroe-Meyer Institute, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Mark Evan Lindsay
- Thoracic Aortic Center, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA.,Division of Pediatric Cardiology, Department of Pediatrics, Mass General for Children, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA.,Division of Cardiology, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA.,Cardiovascular Research Center, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Christian Lacks Lino Cardenas
- Cardiovascular Research Center, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Anji T Yetman
- Division of Cardiology, Children's Hospital and Medical Center, Omaha, Nebraska, USA
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6
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El-Gazzar A, Kang H, Fratzl-Zelman N, Webb E, Barnes AM, Jovanovic M, Mehta SG, Datta V, Saraff V, Dale RK, Rauch F, Marini JC, Högler W. SMAD3 mutation in LDS3 causes bone fragility by impairing the TGF-β pathway and enhancing osteoclastogenesis. Bone Rep 2022; 17:101603. [PMID: 35874167 PMCID: PMC9301510 DOI: 10.1016/j.bonr.2022.101603] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 07/12/2022] [Indexed: 11/30/2022] Open
Abstract
Loss-of-function mutations in SMAD3 cause Loeys-Dietz syndrome type 3 (LDS3), a rare autosomal-dominant connective tissue disorder characterized by vascular pathology and skeletal abnormalities. Dysregulation of TGF-β/SMAD signaling is associated with abnormal skeletal features and bone fragility. To date, histomorphometric and ultrastructural characteristics of bone with SMAD3 mutations have not been reported in humans and the exact mechanism by which SMAD3 mutations cause the LDS3 phenotype is poorly understood. Here, we investigated bone histomorphometry and matrix mineralization in human bone with a SMAD3 mutation and explored the associated cellular defect in the TGF-β/SMAD pathway in vitro. The index patient had recurrent fractures, mild facial dysmorphism, arachnodactyly, pectus excavatum, chest asymmetry and kyphoscoliosis. Bone histomorphometry revealed markedly reduced cortical thickness (−68 %), trabecular thickness (−32 %), bone formation rate (−50 %) and delayed mineralization. Quantitative backscattered electron imaging demonstrated undermineralized bone matrix with increased heterogeneity in mineralization. The patient's SMAD3 mutation (c.200 T > G; p.I67S), when expressed from plasmid vectors in HEK293 cells, showed reduced phosphorylation and transcription factor activity compared to normal control and SMAD3 (p.S264Y), a gain-of-function mutation, somatic mosaicism of which causes melorheostosis. Transfection study of the patients' SMAD3 (p.I67S) mutation displayed lower luciferase reporter activity than normal SMAD3 and reduced expression of TGF-β signaling target genes. Patient fibroblasts also demonstrated impaired SMAD3 protein stability. Osteoclastogenic differentiation significantly increased and osteoclast-associated genes, including ACP5 (encoding TRAP), ATP6V0D2, and DCSTAMP, were up-regulated in CD14 (+) peripheral blood mononuclear cells (PBMCs) with the SMAD3 (p.I67S) mutation. Upregulation of osteoclastogenic genes was associated with decreased expression of TGF-β signaling target genes. We conclude that bone with the SMAD3 (p.I67S) mutation features reduced bone formation, and our functional studies revealed decreased SMAD3 activation and protein stability as well as increased osteoclastogenesis. These findings enhance our understanding of the pathophysiology of LDS3 caused by SMAD3 mutations. Emerging therapies targeting in the TGF-β/SMAD pathway also raise hope for treatment of LDS3. Increased bone fragility Low bone matrix mineralization SMAD3 (p.I67S) decreased TGF-b signaling and SMAD3 activity. SMAD3 (p.I67S) reduced SMAD3 protein stability. SMAD3 (p.I67S) mediated osteoclastogenesis.
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Affiliation(s)
- Ahmed El-Gazzar
- Department of Paediatrics and Adolescent Medicine, Johannes Kepler University Linz, Linz, Austria
| | - Heeseog Kang
- Section on Heritable Disorders of Bone and Extracellular Matrix, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Nadja Fratzl-Zelman
- Ludwig Boltzmann Institute of Osteology at Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1 Medical Department Hanusch Hospital, Vienna, Austria.,Vienna Bone and Growth Center, Vienna, Austria
| | - Emma Webb
- Department of Paediatrics, Jenny Lind Children's Hospital, Norfolk and Norwich University Hospital NHS Foundation Trust, Norwich, UK.,Norwich Medical School, University of East Anglia, Norwich, UK
| | - Aileen M Barnes
- Section on Heritable Disorders of Bone and Extracellular Matrix, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Milena Jovanovic
- Section on Heritable Disorders of Bone and Extracellular Matrix, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Sarju G Mehta
- East Anglian Regional Medical Genetics Service, Addenbrookes Hospital, Cambridge, UK
| | - Vipan Datta
- Department of Paediatrics, Jenny Lind Children's Hospital, Norfolk and Norwich University Hospital NHS Foundation Trust, Norwich, UK
| | - Vrinda Saraff
- Department of Endocrinology and Diabetes, Birmingham Women's and Children's Hospital NHS Foundation Trust, Birmingham, UK
| | - Ryan K Dale
- Bioinformatics and Scientific Programming Core, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD, USA
| | - Frank Rauch
- Shriners Hospital for Children-Canada, Montreal, QC H4A 0A9, Canada.,Department of Human Genetics, McGill University, Montreal, QC H3A 0C7, Canada
| | - Joan C Marini
- Section on Heritable Disorders of Bone and Extracellular Matrix, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Wolfgang Högler
- Department of Paediatrics and Adolescent Medicine, Johannes Kepler University Linz, Linz, Austria.,Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, UK
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7
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Neonatal presentation of Loeys-Dietz syndrome: two case reports and review of the literature. Ital J Pediatr 2022; 48:85. [PMID: 35668506 PMCID: PMC9169291 DOI: 10.1186/s13052-022-01281-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 05/13/2022] [Indexed: 01/24/2023] Open
Abstract
Background Loeys-Dietz syndrome (LDS) is a rare connective tissue disorder characterized by cardiovascular manifestations, especially aortic dilatations and arterial tortuosity, craniofacial and skeletal features, joint laxity or contractures, skin abnormalities, hypotonia and motor delay. Its diagnosis is established by the identification of a pathogenic variant in TGFBR1, TGFBR2, SMAD2, SMAD3, TGFB2 or TGFB3 genes. In newborns and toddlers, vascular complications such as aneurism rupture, aortic dissection, and intracerebral incidents, can occur already in the weeks of life. To avoid these events, it is crucial to precociously identify this condition and to start an apunderwent a surgical procedurepropriate treatment which, depending on the severity of the vascular involvement, might be medical or surgical. Case presentation We report two cases of Loeys-Dietz syndrome precociously diagnosed. The first describes a male, born at 38 + 1 weeks of gestation, with hypotonia, joint hypermobility, arachnodactyly, and fingers joint contractures, as well as senile appearance and facial dysmorphisms. In the suspect of a connective tissue disorder, an echocardiography was performed and revealed an aortic root dilatation of 13 mm (Z score + 3). A trio based Whole Exome Sequencing found a novel de novo variant in the TGFBR2 gene. Despite the onset of a low-dose angiotensin receptor blocker therapy, the aneurysm progressed. The second case describes a female, born at 41 + 3 weeks of gestation. During the neonatal examination a cleft palate was noticed, as well as minor dysmorphisms. Since the family history was suspicious for connective tissue disorders, a genetic panel was performed and identified a pathogenetic variant in TGFB3 gene. In this case, the echocardiography revealed no abnormalities. Conclusions In addition to our cases, we identified 14 subjects with neonatal LDS in the medical literature. All of them had aortic involvement. Skeletal and face abnormalities, including eyes and palate malformations, were also highly frequent. Overall, 10 subjects required medical therapy to avoid aneurysm progression, and 8 patients underwent surgical procedures. Benefits of an early diagnosis of LDS are various and imply a potential modification of the natural history of the disease with early interventions on its complications.
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8
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Chen J, Chang R. Association of TGF-β Canonical Signaling-Related Core Genes With Aortic Aneurysms and Aortic Dissections. Front Pharmacol 2022; 13:888563. [PMID: 35517795 PMCID: PMC9065418 DOI: 10.3389/fphar.2022.888563] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 04/04/2022] [Indexed: 01/17/2023] Open
Abstract
Transforming growth factor-beta (TGF-β) signaling is essential for the maintenance of the normal structure and function of the aorta. It includes SMAD-dependent canonical pathways and noncanonical signaling pathways. Accumulated genetic evidence has shown that TGF-β canonical signaling-related genes have key roles in aortic aneurysms (AAs) and aortic dissections and many gene mutations have been identified in patients, such as those for transforming growth factor-beta receptor one TGFBR1, TGFBR2, SMAD2, SMAD3, SMAD4, and SMAD6. Aortic specimens from patients with these mutations often show paradoxically enhanced TGF-β signaling. Some hypotheses have been proposed and new AA models in mice have been constructed to reveal new mechanisms, but the role of TGF-β signaling in AAs is controversial. In this review, we focus mainly on the role of canonical signaling-related core genes in diseases of the aorta, as well as recent advances in gene-mutation detection, animal models, and in vitro studies.
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Affiliation(s)
- Jicheng Chen
- Department of Vasculocardiology, Shenzhen Longhua District Central Hospital, Guangdong Medical University, Shenzhen, China
| | - Rong Chang
- Department of Vasculocardiology, Shenzhen Longhua District Central Hospital, Guangdong Medical University, Shenzhen, China
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9
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Abstract
Loeys-Dietz syndrome is an autosomal dominant aortic aneurysm syndrome characterized by multisystemic involvement. The most typical clinical triad includes hypertelorism, bifid uvula or cleft palate and aortic aneurysm with tortuosity. Natural history is significant for aortic dissection at smaller aortic diameter and arterial aneurysms throughout the arterial tree. The genetic cause is heterogeneous and includes mutations in genes encoding for components of the transforming growth factor beta (TGFβ) signalling pathway: TGFBR1, TGFBR2, SMAD2, SMAD3, TGFB2 and TGFB3. Despite the loss of function nature of these mutations, the patient-derived aortic tissues show evidence of increased (rather than decreased) TGFβ signalling. These insights offer new options for therapeutic interventions.
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10
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Agnew C, Ayaz P, Kashima R, Loving HS, Ghatpande P, Kung JE, Underbakke ES, Shan Y, Shaw DE, Hata A, Jura N. Structural basis for ALK2/BMPR2 receptor complex signaling through kinase domain oligomerization. Nat Commun 2021; 12:4950. [PMID: 34400635 PMCID: PMC8368100 DOI: 10.1038/s41467-021-25248-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 07/30/2021] [Indexed: 01/10/2023] Open
Abstract
Upon ligand binding, bone morphogenetic protein (BMP) receptors form active tetrameric complexes, comprised of two type I and two type II receptors, which then transmit signals to SMAD proteins. The link between receptor tetramerization and the mechanism of kinase activation, however, has not been elucidated. Here, using hydrogen deuterium exchange mass spectrometry (HDX-MS), small angle X-ray scattering (SAXS) and molecular dynamics (MD) simulations, combined with analysis of SMAD signaling, we show that the kinase domain of the type I receptor ALK2 and type II receptor BMPR2 form a heterodimeric complex via their C-terminal lobes. Formation of this dimer is essential for ligand-induced receptor signaling and is targeted by mutations in BMPR2 in patients with pulmonary arterial hypertension (PAH). We further show that the type I/type II kinase domain heterodimer serves as the scaffold for assembly of the active tetrameric receptor complexes to enable phosphorylation of the GS domain and activation of SMADs.
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Affiliation(s)
- Christopher Agnew
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, USA
| | | | - Risa Kashima
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, USA
| | - Hanna S Loving
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA, USA
| | - Prajakta Ghatpande
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, USA
| | - Jennifer E Kung
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, USA
- Department of Structural Biology, Genentech, Inc., South San Francisco, USA
| | - Eric S Underbakke
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA, USA.
| | | | - David E Shaw
- D. E. Shaw Research, New York, NY, USA.
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA.
| | - Akiko Hata
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, USA
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA
| | - Natalia Jura
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, USA.
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA, USA.
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11
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Morningstar JE, Nieman A, Wang C, Beck T, Harvey A, Norris RA. Mitral Valve Prolapse and Its Motley Crew-Syndromic Prevalence, Pathophysiology, and Progression of a Common Heart Condition. J Am Heart Assoc 2021; 10:e020919. [PMID: 34155898 PMCID: PMC8403286 DOI: 10.1161/jaha.121.020919] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 04/21/2021] [Indexed: 01/01/2023]
Abstract
Mitral valve prolapse (MVP) is a commonly occurring heart condition defined by enlargement and superior displacement of the mitral valve leaflet(s) during systole. Although commonly seen as a standalone disorder, MVP has also been described in case reports and small studies of patients with various genetic syndromes. In this review, we analyzed the prevalence of MVP within syndromes where an association to MVP has previously been reported. We further discussed the shared biological pathways that cause MVP in these syndromes, as well as how MVP in turn causes a diverse array of cardiac and noncardiac complications. We found 105 studies that identified patients with mitral valve anomalies within 18 different genetic, developmental, and connective tissue diseases. We show that some disorders previously believed to have an increased prevalence of MVP, including osteogenesis imperfecta, fragile X syndrome, Down syndrome, and Pseudoxanthoma elasticum, have few to no studies that use up-to-date diagnostic criteria for the disease and therefore may be overestimating the prevalence of MVP within the syndrome. Additionally, we highlight that in contrast to early studies describing MVP as a benign entity, the clinical course experienced by patients can be heterogeneous and may cause significant cardiovascular morbidity and mortality. Currently only surgical correction of MVP is curative, but it is reserved for severe cases in which irreversible complications of MVP may already be established; therefore, a review of clinical guidelines to allow for earlier surgical intervention may be warranted to lower cardiovascular risk in patients with MVP.
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Affiliation(s)
- Jordan E. Morningstar
- Department of Regenerative Medicine and Cell BiologyMedical University of South CarolinaCharlestonSC
| | - Annah Nieman
- Department of Regenerative Medicine and Cell BiologyMedical University of South CarolinaCharlestonSC
| | - Christina Wang
- Department of Regenerative Medicine and Cell BiologyMedical University of South CarolinaCharlestonSC
| | - Tyler Beck
- Department of Regenerative Medicine and Cell BiologyMedical University of South CarolinaCharlestonSC
| | - Andrew Harvey
- Department of Regenerative Medicine and Cell BiologyMedical University of South CarolinaCharlestonSC
| | - Russell A. Norris
- Department of Regenerative Medicine and Cell BiologyMedical University of South CarolinaCharlestonSC
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12
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Gori I, George R, Purkiss AG, Strohbuecker S, Randall RA, Ogrodowicz R, Carmignac V, Faivre L, Joshi D, Kjær S, Hill CS. Mutations in SKI in Shprintzen-Goldberg syndrome lead to attenuated TGF-β responses through SKI stabilization. eLife 2021; 10:e63545. [PMID: 33416497 PMCID: PMC7834018 DOI: 10.7554/elife.63545] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 01/07/2021] [Indexed: 12/12/2022] Open
Abstract
Shprintzen-Goldberg syndrome (SGS) is a multisystemic connective tissue disorder, with considerable clinical overlap with Marfan and Loeys-Dietz syndromes. These syndromes have commonly been associated with enhanced TGF-β signaling. In SGS patients, heterozygous point mutations have been mapped to the transcriptional co-repressor SKI, which is a negative regulator of TGF-β signaling that is rapidly degraded upon ligand stimulation. The molecular consequences of these mutations, however, are not understood. Here we use a combination of structural biology, genome editing, and biochemistry to show that SGS mutations in SKI abolish its binding to phosphorylated SMAD2 and SMAD3. This results in stabilization of SKI and consequently attenuation of TGF-β responses, both in knockin cells expressing an SGS mutation and in fibroblasts from SGS patients. Thus, we reveal that SGS is associated with an attenuation of TGF-β-induced transcriptional responses, and not enhancement, which has important implications for other Marfan-related syndromes.
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Affiliation(s)
- Ilaria Gori
- Developmental Signalling Laboratory, The Francis Crick InstituteLondonUnited Kingdom
| | - Roger George
- Structural Biology Facility, The Francis Crick InstituteLondonUnited Kingdom
| | - Andrew G Purkiss
- Structural Biology Facility, The Francis Crick InstituteLondonUnited Kingdom
| | - Stephanie Strohbuecker
- Bioinformatics and Biostatistics Facility, The Francis Crick InstituteLondonUnited Kingdom
| | - Rebecca A Randall
- Developmental Signalling Laboratory, The Francis Crick InstituteLondonUnited Kingdom
| | - Roksana Ogrodowicz
- Structural Biology Facility, The Francis Crick InstituteLondonUnited Kingdom
| | | | - Laurence Faivre
- INSERM - Université de Bourgogne UMR1231 GAD, FHU-TRANSLADDijonFrance
| | - Dhira Joshi
- Peptide Chemistry Facility, The Francis Crick InstituteLondonUnited Kingdom
| | - Svend Kjær
- Structural Biology Facility, The Francis Crick InstituteLondonUnited Kingdom
| | - Caroline S Hill
- Developmental Signalling Laboratory, The Francis Crick InstituteLondonUnited Kingdom
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13
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Luo X, Deng S, Jiang Y, Wang X, Al-Raimi AMA, Wu L, Liu X, Song Y, Chen X, Zhu F. Identification of a Pathogenic TGFBR2 Variant in a Patient With Loeys-Dietz Syndrome. Front Genet 2020; 11:479. [PMID: 32528524 PMCID: PMC7266969 DOI: 10.3389/fgene.2020.00479] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Accepted: 04/17/2020] [Indexed: 12/21/2022] Open
Abstract
Loeys-Dietz syndrome (LDS) is a rare connective tissue genetic disorder that is caused by a pathogenic variant in genes of transforming growth factor (TGF) beta receptor 1 (TGFBR1), TGFBR2, mothers against decapentaplegic homolog 2 (SMAD2), SMAD3, TGFB2, or TGFB3. It is characterized by aggressive vascular pathology, aneurysms, arterial tortuosity, bifid uvula, hypertelorism, and cleft palate. Here we present a 42-year-old female patient with LDS. The patient underwent rapidly progressing artery aneurysms and life-threatening aortic dissection. Spontaneous fracture of the first metatarsal bone was noted in her medical record. Physical examination revealed a delayed wound healing on her left abdomen. Considering these clinical manifestations, we speculated that there was a genetic defect in the connective tissue, which provides strength and flexibility to structures such as bones, skins, ligaments, and blood vessels. Thus, whole exome sequencing (WES) was performed on the proband and revealed a heterozygous missense pathogenic variant (c.1613T > C/p.Val538Ala) in TGFBR2, which was a de novo variant in the proband as confirmed by the segregation analysis in parental samples. Although this variant was discovered and associated with the phenotype of LDS previously, the pathogenicity of the variant had not been confirmed by cellular functional assay yet. To further validate the effects of the variant in vitro, we assessed the canonical TGF-β signaling pathway in mutant cells. Our results showed that the p.Val538Ala variant significantly decreased TGF-β-induced gene transcription and the phosphorylation of Smad2, which were consistent with other pathogenic variants of TGFBR2. In conclusion, this study demonstrates that the p.Val538Ala pathogenic variant in TGFBR2 leads to aberrant TGF-β signaling and LDS in this patient.
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Affiliation(s)
- Xi Luo
- Department of Cardiology, Wuhan Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Clinic Center of Human Gene Research, Wuhan Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Shan Deng
- Department of Cardiology, Wuhan Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Clinic Center of Human Gene Research, Wuhan Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ying Jiang
- Department of Cardiology, Wuhan Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiang Wang
- Department of Cardiology, Wuhan Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | | | - Long Wu
- Department of Cardiovascular Surgery, Wuhan Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiaobin Liu
- Department of Cardiovascular Surgery, Wuhan Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yu Song
- Department of Cardiovascular Surgery, Wuhan Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiao Chen
- Department of Cardiology, Wuhan Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Feng Zhu
- Department of Cardiology, Wuhan Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Clinic Center of Human Gene Research, Wuhan Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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14
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Abstract
Dissections or ruptures of aortic aneurysms remain a leading cause of death in the developed world, with the majority of deaths being preventable if individuals at risk are identified and properly managed. Genetic variants predispose individuals to these aortic diseases. In the case of thoracic aortic aneurysm and dissections (thoracic aortic disease), genetic data can be used to identify some at-risk individuals and dictate management of the associated vascular disease. For abdominal aortic aneurysms, genetic associations have been identified, which provide insight on the molecular pathogenesis but cannot be used clinically yet to identify individuals at risk for abdominal aortic aneurysms. This compendium will discuss our current understanding of the genetic basis of thoracic aortic disease and abdominal aortic aneurysm disease. Although both diseases share several pathogenic similarities, including proteolytic elastic tissue degeneration and smooth muscle dysfunction, they also have several distinct differences, including population prevalence and modes of inheritance.
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Affiliation(s)
- Amélie Pinard
- From the Division of Medical Genetics, Department of Internal Medicine, McGovern Medical School; University of Texas Health Science Center at Houston (A.P., D.M.M.)
| | - Gregory T Jones
- Department of Surgical Sciences, Dunedin School of Medicine, University of Otago, New Zealand (G.T.J.)
| | - Dianna M Milewicz
- From the Division of Medical Genetics, Department of Internal Medicine, McGovern Medical School; University of Texas Health Science Center at Houston (A.P., D.M.M.)
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15
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Brunner P, Hastar N, Kaehler C, Burdzinski W, Jatzlau J, Knaus P. AMOT130 drives BMP-SMAD signaling at the apical membrane in polarized cells. Mol Biol Cell 2019; 31:118-130. [PMID: 31800378 PMCID: PMC6960409 DOI: 10.1091/mbc.e19-03-0179] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The large isoform of the transmembrane protein angiomotin (AMOT130) controls cell proliferation and migration of many cell types. AMOT130 associates to the actin cytoskeleton and regulates tight-junction maintenance and signaling often via endosomal uptake of polarity proteins at tight junctions. AMOT130 is highly polarized and present only at the apical side of polarized cells. Here we show that bone morphogenetic protein (BMP) growth factor signaling and AMOT function are interlinked in apical-basal polarized cells. BMP6 controls AMOT internalization and endosomal trafficking in epithelial cells. AMOT130 interacts with the BMP receptor BMPR2 and facilitates SMAD activation and target gene expression. We further demonstrate that this effect of AMOT on BMP-SMAD signaling is dependent on endocytosis and specific to the apical side of polarized epithelial and endothelial cells. Knockdown of AMOT reduces SMAD signaling only from the apical side of polarized cells, while basolateral BMP-SMAD signaling is unaffected. This allows for the first time interference with BMP signaling in a polarized manner and identifies AMOT130 as a novel BMP signaling regulator.
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Affiliation(s)
- Patrizia Brunner
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany.,Berlin School of Integrative Oncology, Charité-Universitätsmedizin Berlin, 13353 Berlin, Germany
| | - Nurcan Hastar
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany.,Berlin-Brandenburg School for Regenerative Therapies, Charité-Universitätsmedizin Berlin, 13353 Berlin, Germany
| | - Christian Kaehler
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany
| | - Wiktor Burdzinski
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany
| | - Jerome Jatzlau
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany.,Berlin-Brandenburg School for Regenerative Therapies, Charité-Universitätsmedizin Berlin, 13353 Berlin, Germany
| | - Petra Knaus
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany.,Berlin-Brandenburg School for Regenerative Therapies, Charité-Universitätsmedizin Berlin, 13353 Berlin, Germany
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16
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Fujiwara T, Takeda N, Ishii S, Morita H, Komuro I. Unique Mechanism by Which TGFBR1 Variants Cause 2 Distinct System Diseases - Loeys-Dietz Syndrome and Multiple Self-Healing Squamous Epithelioma. Circ Rep 2019; 1:487-492. [PMID: 33693090 PMCID: PMC7897567 DOI: 10.1253/circrep.cr-19-0098] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Variant types and sites in a single gene could influence the age of onset, severity, and pattern of affected organs of the genetic disease, such as in Marfan syndrome (MFS)-causing
FBN1, and understanding the genotype-phenotype relationship could aid in determining the treatment strategy. In contrast, completely distinct system and/or organ diseases induced by 1 gene mutation have been rarely reported. Transforming growth factor-β (TGF-β) type I receptor-encoding
TGFBR1
is such a gene, causing Loeys-Dietz syndrome (LDS) closely related to MFS, and also multiple self-healing squamous epithelioma (MSSE) without clinical overlap. The detailed mechanisms underlying this effect, however, remain elusive. We recently reported the significance of 2 distinct intronic variants (c.973+1G>A and c.806-2A>C) of
TGFBR1, which were both predicted to mediate in-frame exon 5 skipping but caused LDS and MSSE, respectively. On ex vivo minigene splicing assay analysis we demonstrated that 2 different cryptic splice sites were activated, and in-frame and out-of-frame transcripts were produced in LDS and MSSE, respectively, supporting the previously proposed but not yet approved mechanism that loss-of-function and haploinsufficiency-causing variants in serine/threonine kinase domains induce LDS and MSSE, respectively. In this review, we briefly summarize the recent findings and unresolved problems for the pathogenesis of LDS, including the TGF-β signaling paradox: most variants have been verified or predicted to be loss of function in vitro, but these variants enhanced TGF-β signaling in vivo.
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Affiliation(s)
- Takayuki Fujiwara
- Department of Cardiovascular Medicine, The University of Tokyo Hospital Tokyo Japan.,Department of Therapeutic Strategy for Heart Failure, Graduate School of Medicine, The University of Tokyo Tokyo Japan
| | - Norifumi Takeda
- Department of Cardiovascular Medicine, The University of Tokyo Hospital Tokyo Japan
| | - Satoshi Ishii
- Department of Cardiovascular Medicine, The University of Tokyo Hospital Tokyo Japan
| | - Hiroyuki Morita
- Department of Cardiovascular Medicine, The University of Tokyo Hospital Tokyo Japan
| | - Issei Komuro
- Department of Cardiovascular Medicine, The University of Tokyo Hospital Tokyo Japan
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17
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Malhotra S, Alsulami AF, Heiyun Y, Ochoa BM, Jubb H, Forbes S, Blundell TL. Understanding the impacts of missense mutations on structures and functions of human cancer-related genes: A preliminary computational analysis of the COSMIC Cancer Gene Census. PLoS One 2019; 14:e0219935. [PMID: 31323058 PMCID: PMC6641202 DOI: 10.1371/journal.pone.0219935] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Accepted: 07/03/2019] [Indexed: 12/12/2022] Open
Abstract
Genomics and genome screening are proving central to the study of cancer. However, a good appreciation of the protein structures coded by cancer genes is also invaluable, especially for the understanding of functions, for assessing ligandability of potential targets, and for designing new drugs. To complement the wealth of information on the genetics of cancer in COSMIC, the most comprehensive database for cancer somatic mutations available, structural information obtained experimentally has been brought together recently in COSMIC-3D. Even where structural information is available for a gene in the Cancer Gene Census, a list of genes in COSMIC with substantial evidence supporting their impacts in cancer, this information is quite often for a single domain in a larger protein or for a single protomer in a multiprotein assembly. Here, we show that over 60% of the genes included in the Cancer Gene Census are predicted to possess multiple domains. Many are also multicomponent and membrane-associated molecular assemblies, with mutations recorded in COSMIC affecting such assemblies. However, only 469 of the gene products have a structure represented in the PDB, and of these only 87 structures have 90-100% coverage over the sequence and 69 have less than 10% coverage. As a first step to bridging gaps in our knowledge in the many cases where individual protein structures and domains are lacking, we discuss our attempts of protein structure modelling using our pipeline and investigating the effects of mutations using two of our in-house methods (SDM2 and mCSM) and identifying potential driver mutations. This allows us to begin to understand the effects of mutations not only on protein stability but also on protein-protein, protein-ligand and protein-nucleic acid interactions. In addition, we consider ways to combine the structural information with the wealth of mutation data available in COSMIC. We discuss the impacts of COSMIC missense mutations on protein structure in order to identify and assess the molecular consequences of cancer-driving mutations.
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Affiliation(s)
- Sony Malhotra
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Ali F. Alsulami
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Yang Heiyun
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | | | - Harry Jubb
- Wellcome Genome Campus, Hinxton, Cambridgeshire, United Kingdom
| | - Simon Forbes
- Wellcome Genome Campus, Hinxton, Cambridgeshire, United Kingdom
| | - Tom L. Blundell
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
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18
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Lin J, Vora M, Kane NS, Gleason RJ, Padgett RW. Human Marfan and Marfan-like Syndrome associated mutations lead to altered trafficking of the Type II TGFβ receptor in Caenorhabditis elegans. PLoS One 2019; 14:e0216628. [PMID: 31071172 PMCID: PMC6508650 DOI: 10.1371/journal.pone.0216628] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 04/24/2019] [Indexed: 12/14/2022] Open
Abstract
The transforming growth factor-β (TGFβ) family plays an important role in many developmental processes and when mutated often contributes to various diseases. Marfan syndrome is a genetic disease with an occurrence of approximately 1 in 5,000. The disease is caused by mutations in fibrillin, which lead to an increase in TGFβ ligand activity, resulting in abnormalities of connective tissues which can be life-threatening. Mutations in other components of TGFβ signaling (receptors, Smads, Schnurri) lead to similar diseases with attenuated phenotypes relative to Marfan syndrome. In particular, mutations in TGFβ receptors, most of which are clustered at the C-terminal end, result in Marfan-like (MFS-like) syndromes. Even though it was assumed that many of these receptor mutations would reduce or eliminate signaling, in many cases signaling is active. From our previous studies on receptor trafficking in C. elegans, we noticed that many of these receptor mutations that lead to Marfan-like syndromes overlap with mutations that cause mis-trafficking of the receptor, suggesting a link between Marfan-like syndromes and TGFβ receptor trafficking. To test this hypothesis, we introduced three of these key MFS and MFS-like mutations into the C. elegans TGFβ receptor and asked if receptor trafficking is altered. We find that in every case studied, mutated receptors mislocalize to the apical surface rather than basolateral surface of the polarized intestinal cells. Further, we find that these mutations result in longer animals, a phenotype due to over-stimulation of the nematode TGFβ pathway and, importantly, indicating that function of the receptor is not abrogated in these mutants. Our nematode models of Marfan syndrome suggest that MFS and MFS-like mutations in the type II receptor lead to mis-trafficking of the receptor and possibly provides an explanation for the disease, a phenomenon which might also occur in some cancers that possess the same mutations within the type II receptor (e.g. colon cancer).
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MESH Headings
- Amino Acid Sequence
- Amino Acid Substitution
- Animals
- Animals, Genetically Modified
- Caenorhabditis elegans/genetics
- Caenorhabditis elegans/metabolism
- Caenorhabditis elegans Proteins/chemistry
- Caenorhabditis elegans Proteins/genetics
- Caenorhabditis elegans Proteins/metabolism
- Disease Models, Animal
- Humans
- Marfan Syndrome/genetics
- Marfan Syndrome/metabolism
- Mutation, Missense
- Protein Domains
- Receptor, Transforming Growth Factor-beta Type II/chemistry
- Receptor, Transforming Growth Factor-beta Type II/genetics
- Receptor, Transforming Growth Factor-beta Type II/metabolism
- Receptors, Cell Surface/genetics
- Receptors, Cell Surface/metabolism
- Receptors, Transforming Growth Factor beta/chemistry
- Receptors, Transforming Growth Factor beta/genetics
- Receptors, Transforming Growth Factor beta/metabolism
- Recombinant Proteins/chemistry
- Recombinant Proteins/genetics
- Recombinant Proteins/metabolism
- Sequence Homology, Amino Acid
- Species Specificity
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Affiliation(s)
- Jing Lin
- Waksman Institute, Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, New Jersey, United States of America
| | - Mehul Vora
- Waksman Institute, Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, New Jersey, United States of America
- * E-mail: (MV); (RWP)
| | - Nanci S. Kane
- Waksman Institute, Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, New Jersey, United States of America
| | - Ryan J. Gleason
- Department of Biology, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Richard W. Padgett
- Waksman Institute, Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, New Jersey, United States of America
- * E-mail: (MV); (RWP)
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19
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Takeda N, Hara H, Fujiwara T, Kanaya T, Maemura S, Komuro I. TGF-β Signaling-Related Genes and Thoracic Aortic Aneurysms and Dissections. Int J Mol Sci 2018; 19:ijms19072125. [PMID: 30037098 PMCID: PMC6073540 DOI: 10.3390/ijms19072125] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 07/13/2018] [Accepted: 07/16/2018] [Indexed: 12/29/2022] Open
Abstract
Transforming growth factor-β (TGF)-β signaling plays a crucial role in the development and maintenance of various organs, including the vasculature. Accordingly, the mutations in TGF-β signaling pathway-related genes cause heritable disorders of the connective tissue, such as Marfan syndrome (MFS), Loeys-Dietz syndrome (LDS), and Shprintzen-Goldberg syndrome (SGS), and these syndromes may affect skeletal, ocular, pulmonary, and cardiovascular systems. Aortic root aneurysms are common problems that can result in aortic dissection or rupture, which is the leading cause of sudden death in the natural history of MFS and LDS, and recent improvements in surgical treatment have improved life expectancy. However, there is currently no genotype-specific medical treatment. Accumulating evidence suggest that not only structural weakness of connective tissue but also increased TGF-β signaling contributes to the complicated pathogenesis of aortic aneurysm formation, but a comprehensive understanding of governing molecular mechanisms remains lacking. Inhibition of angiotensin II receptor signaling and endothelial dysfunction have gained attention as a possible MFS treatment strategy, but interactions with TGF-β signaling remain elusive. Heterozygous loss-of-function mutations in TGF-β receptors 1 and 2 (TGFBR1 and TGFBR2) cause LDS, but TGF-β signaling is activated in the aorta (referred to as the TGF-β paradox) by mechanisms yet to be elucidated. In this review, we present and discuss the current understanding of molecular mechanisms responsible for aortopathies of MFS and related disorders.
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Affiliation(s)
- Norifumi Takeda
- Department of Cardiovascular Medicine, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
| | - Hironori Hara
- Department of Cardiovascular Medicine, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
| | - Takayuki Fujiwara
- Department of Cardiovascular Medicine, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
| | - Tsubasa Kanaya
- Department of Cardiovascular Medicine, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
| | - Sonoko Maemura
- Department of Cardiovascular Medicine, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
| | - Issei Komuro
- Department of Cardiovascular Medicine, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
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20
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Distinct variants affecting differential splicing of TGFBR1 exon 5 cause either Loeys-Dietz syndrome or multiple self-healing squamous epithelioma. Eur J Hum Genet 2018; 26:1151-1158. [PMID: 29706644 DOI: 10.1038/s41431-018-0127-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Revised: 01/12/2018] [Accepted: 02/13/2018] [Indexed: 11/09/2022] Open
Abstract
Variants in TGFBR1 have been reported to induce two completely distinct diseases, namely Loeys-Dietz syndrome (LDS) and multiple self-healing squamous epithelioma (MSSE). However, detailed mechanisms underlying this effect remain unknown. We report a Japanese familial case of LDS with a novel splice donor site variant in TGFBR1 gene (c.973 + 1 G > A; NG_007461.1). The intronic variant was predicted to mediate in-frame exon 5 skipping within the serine/threonine kinase (STK) domain, which may also be mediated by a similar TGFBR1 variant of a splice acceptor site in intron 4 (c.806-2 A > C), identified in a British familial case of MSSE. Therefore, ex vivo splicing and functional assays were performed in mammalian cells to evaluate the effect of these sequence variants. The MSSE variant activated a cryptic acceptor site at 76 bp downstream of the 3' natural splice acceptor site, which produced an out-of-frame transcript (r.807_882del, p.Asn270Thrfs*8). In contrast, the LDS variant generated two types of in-frame transcription products, r.[806_973del, 965_973 del], and produced two functionally inactivated proteins, p.[Asp269_Gln324del, Thr323_Gly325del], as a result of exon 5 skipping and the activation of a cryptic donor splice site at 9 bp upstream of the 5' natural splice donor site, respectively. Our results support the previously proposed but not yet approved mechanism that dominant-negative and truncating variants in STK domain induce LDS and MSSE, respectively.
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21
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Guo DC, Regalado ES, Pinard A, Chen J, Lee K, Rigelsky C, Zilberberg L, Hostetler EM, Aldred M, Wallace SE, Prakash SK, Leal SM, Bamshad MJ, Nickerson DA, Natowicz M, Rifkin DB, Milewicz DM, Milewicz DM. LTBP3 Pathogenic Variants Predispose Individuals to Thoracic Aortic Aneurysms and Dissections. Am J Hum Genet 2018; 102:706-712. [PMID: 29625025 DOI: 10.1016/j.ajhg.2018.03.002] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 02/20/2018] [Indexed: 01/30/2023] Open
Abstract
The major diseases affecting the thoracic aorta are aneurysms and acute dissections, and pathogenic variants in 11 genes are confirmed to lead to heritable thoracic aortic disease. However, many families in which multiple members have thoracic aortic disease do not have alterations in the known aortopathy genes. Genes highly expressed in the aorta were assessed for rare variants in exome sequencing data from such families, and compound rare heterozygous variants (p.Pro45Argfs∗25 and p.Glu750∗) in LTBP3 were identified in affected members of one family. A homozygous variant (p.Asn678_Gly681delinsThrCys) that introduces an additional cysteine into an epidermal growth factor (EGF)-like domain in the corresponding protein, latent TGF-β binding protein (LTBP-3), was identified in a second family. Individuals with compound heterozygous or homozygous variants in these families have aneurysms and dissections of the thoracic aorta, as well as aneurysms of the abdominal aorta and other arteries, along with dental abnormalities and short stature. Heterozygous carriers of the p.Asn678_Gly681delinsThrCys variant have later onset of thoracic aortic disease, as well as dental abnormalities. In these families, LTBP3 variants segregated with thoracic aortic disease with a combined LOD score of 3.9. Additionally, heterozygous rare LTBP3 variants were found in individuals with early onset of acute aortic dissections, and some of these variants disrupted LTBP-3 levels or EGF-like domains. When compared to wild-type mice, Ltbp3-/- mice have enlarged aortic roots and ascending aortas. In summary, homozygous LTBP3 pathogenic variants predispose individuals to thoracic aortic aneurysms and dissections, along with the previously described skeletal and dental abnormalities.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Dianna M Milewicz
- Department of Internal Medicine, University of Texas Health Science Center at Houston McGovern Medical School, Houston, TX 77030, USA.
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22
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Goumans MJ, Ten Dijke P. TGF-β Signaling in Control of Cardiovascular Function. Cold Spring Harb Perspect Biol 2018; 10:cshperspect.a022210. [PMID: 28348036 DOI: 10.1101/cshperspect.a022210] [Citation(s) in RCA: 192] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Genetic studies in animals and humans indicate that gene mutations that functionally perturb transforming growth factor β (TGF-β) signaling are linked to specific hereditary vascular syndromes, including Osler-Rendu-Weber disease or hereditary hemorrhagic telangiectasia and Marfan syndrome. Disturbed TGF-β signaling can also cause nonhereditary disorders like atherosclerosis and cardiac fibrosis. Accordingly, cell culture studies using endothelial cells or smooth muscle cells (SMCs), cultured alone or together in two- or three-dimensional cell culture assays, on plastic or embedded in matrix, have shown that TGF-β has a pivotal effect on endothelial and SMC proliferation, differentiation, migration, tube formation, and sprouting. Moreover, TGF-β can stimulate endothelial-to-mesenchymal transition, a process shown to be of key importance in heart valve cushion formation and in various pathological vascular processes. Here, we discuss the roles of TGF-β in vasculogenesis, angiogenesis, and lymphangiogenesis and the deregulation of TGF-β signaling in cardiovascular diseases.
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Affiliation(s)
- Marie-José Goumans
- Department of Molecular Cell Biology and Cancer Genomics Centre Netherlands, Leiden University Medical Center, 2300 RC Leiden, The Netherlands
| | - Peter Ten Dijke
- Department of Molecular Cell Biology and Cancer Genomics Centre Netherlands, Leiden University Medical Center, 2300 RC Leiden, The Netherlands
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23
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MacFarlane EG, Haupt J, Dietz HC, Shore EM. TGF-β Family Signaling in Connective Tissue and Skeletal Diseases. Cold Spring Harb Perspect Biol 2017; 9:cshperspect.a022269. [PMID: 28246187 DOI: 10.1101/cshperspect.a022269] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The transforming growth factor β (TGF-β) family of signaling molecules, which includes TGF-βs, activins, inhibins, and numerous bone morphogenetic proteins (BMPs) and growth and differentiation factors (GDFs), has important functions in all cells and tissues, including soft connective tissues and the skeleton. Specific TGF-β family members play different roles in these tissues, and their activities are often balanced with those of other TGF-β family members and by interactions with other signaling pathways. Perturbations in TGF-β family pathways are associated with numerous human diseases with prominent involvement of the skeletal and cardiovascular systems. This review focuses on the role of this family of signaling molecules in the pathologies of connective tissues that manifest in rare genetic syndromes (e.g., syndromic presentations of thoracic aortic aneurysm), as well as in more common disorders (e.g., osteoarthritis and osteoporosis). Many of these diseases are caused by or result in pathological alterations of the complex relationship between the TGF-β family of signaling mediators and the extracellular matrix in connective tissues.
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Affiliation(s)
- Elena Gallo MacFarlane
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Julia Haupt
- Department of Orthopedic Surgery, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104.,Center for Research in FOP and Related Disorders, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Harry C Dietz
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205.,Howard Hughes Medical Institute, Bethesda, Maryland 21205
| | - Eileen M Shore
- Department of Orthopedic Surgery, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104.,Center for Research in FOP and Related Disorders, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104.,Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104
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24
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Cousin MA, Zimmermann MT, Mathison AJ, Blackburn PR, Boczek NJ, Oliver GR, Lomberk GA, Urrutia RA, Deyle DR, Klee EW. Functional validation reveals the novel missense V419L variant in TGFBR2 associated with Loeys-Dietz syndrome (LDS) impairs canonical TGF-β signaling. Cold Spring Harb Mol Case Stud 2017; 3:mcs.a001727. [PMID: 28679693 PMCID: PMC5495030 DOI: 10.1101/mcs.a001727] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 04/12/2017] [Indexed: 12/31/2022] Open
Abstract
TGF-β-related heritable connective tissue disorders are characterized by a similar pattern of cardiovascular defects, including aortic root dilatation, mitral valve prolapse, vascular aneurysms, and vascular dissections and exhibit incomplete penetrance and variable expressivity. Because of the phenotypic overlap of these disorders, panel-based genetic testing is frequently used to confirm the clinical findings. Unfortunately in many cases, variants of uncertain significance (VUSs) obscure the genetic diagnosis until more information becomes available. Here, we describe and characterize the functional impact of a novel VUS in the TGFBR2 kinase domain (c.1255G>T; p.Val419Leu), in a patient with the clinical diagnosis of Marfan syndrome spectrum. We assessed the structural and functional consequence of this VUS using molecular modeling, molecular dynamic simulations, and in vitro cell-based assays. A high-quality homology-based model of TGFBR2 was generated and computational mutagenesis followed by refinement and molecular dynamics simulations were used to assess structural and dynamic changes. Relative to wild type, the V419L induced conformational and dynamic changes that may affect ATP binding, increasing the likelihood of adopting an inactive state, and, we hypothesize, alter canonical signaling. Experimentally, we tested this by measuring the canonical TGF-β signaling pathway activation at two points; V419L significantly delayed SMAD2 phosphorylation by western blot and significantly decreased TGF-β-induced gene transcription by reporter assays consistent with known pathogenic variants in this gene. Thus, our results establish that the V419L variant leads to aberrant TGF-β signaling and confirm the diagnosis of Loeys-Dietz syndrome in this patient.
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Affiliation(s)
- Margot A Cousin
- Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota 55905, USA.,Center for Individualized Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA
| | - Michael T Zimmermann
- Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota 55905, USA
| | - Angela J Mathison
- Laboratory of Epigenetics and Chromatin Dynamics, Gastroenterology Research Unit, Department of Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA
| | - Patrick R Blackburn
- Department of Health Sciences Research, Mayo Clinic, Jacksonville, Florida 32224, USA.,Center for Individualized Medicine, Mayo Clinic, Jacksonville, Florida 32224, USA
| | - Nicole J Boczek
- Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota 55905, USA.,Center for Individualized Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA
| | - Gavin R Oliver
- Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota 55905, USA
| | - Gwen A Lomberk
- Laboratory of Epigenetics and Chromatin Dynamics, Gastroenterology Research Unit, Department of Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA.,Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota 55905, USA
| | - Raul A Urrutia
- Center for Individualized Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA.,Laboratory of Epigenetics and Chromatin Dynamics, Gastroenterology Research Unit, Department of Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA
| | - David R Deyle
- Center for Individualized Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA.,Department of Clinic Genomics, Mayo Clinic, Rochester, Minnesota 55905, USA
| | - Eric W Klee
- Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota 55905, USA.,Center for Individualized Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA.,Department of Clinic Genomics, Mayo Clinic, Rochester, Minnesota 55905, USA
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25
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Smooth muscle cell-specific Tgfbr1 deficiency promotes aortic aneurysm formation by stimulating multiple signaling events. Sci Rep 2016; 6:35444. [PMID: 27739498 PMCID: PMC5064316 DOI: 10.1038/srep35444] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 09/29/2016] [Indexed: 12/21/2022] Open
Abstract
Transforming growth factor (TGF)-β signaling disorder has emerged as a common molecular signature for aortic aneurysm development. The timing of postnatal maturation plays a key role in dictating the biological outcome of TGF-β signaling disorders in the aortic wall. In this study, we investigated the impact of deficiency of TGFβ receptors on the structural homeostasis of mature aortas. We used an inducible Cre-loxP system driven by a Myh11 promoter to delete Tgfbr1, Tgfbr2, or both in smooth muscle cells (SMCs) of adult mice. TGFBR1 deficiency resulted in rapid and severe aneurysmal degeneration, with 100% penetrance of ascending thoracic aortas, whereas TGFBR2 deletion only caused mild aortic pathology with low (26%) lesion prevalence. Removal of TGFBR2 attenuated the aortic pathology caused by TGFBR1 deletion and correlated with a reduction of early ERK phosphorylation. In addition, the production of angiotensin (Ang)-converting enzyme was upregulated in TGFBR1 deficient aortas at the early stage of aneurysmal degeneration. Inhibition of ERK phosphorylation or blockade of AngII type I receptor AT1R prevented aneurysmal degeneration of TGFBR1 deficient aortas. In conclusion, loss of SMC-Tgfbr1 triggers multiple deleterious pathways, including abnormal TGFBR2, ERK, and AngII/AT1R signals that disrupt aortic wall homeostasis to cause aortic aneurysm formation.
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26
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Abstract
Transforming growth factor β (TGF-β) family members signal via heterotetrameric complexes of type I and type II dual specificity kinase receptors. The activation and stability of the receptors are controlled by posttranslational modifications, such as phosphorylation, ubiquitylation, sumoylation, and neddylation, as well as by interaction with other proteins at the cell surface and in the cytoplasm. Activation of TGF-β receptors induces signaling via formation of Smad complexes that are translocated to the nucleus where they act as transcription factors, as well as via non-Smad pathways, including the Erk1/2, JNK and p38 MAP kinase pathways, and the Src tyrosine kinase, phosphatidylinositol 3'-kinase, and Rho GTPases.
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Affiliation(s)
- Carl-Henrik Heldin
- Ludwig Institute for Cancer Research Ltd., Science for Life Laboratory, Uppsala University, SE-751 24 Uppsala, Sweden
| | - Aristidis Moustakas
- Ludwig Institute for Cancer Research Ltd., Science for Life Laboratory, Uppsala University, SE-751 24 Uppsala, Sweden Department of Medical Biochemistry and Microbiology, Science for Life Laboratory, Uppsala University, SE-751 23 Uppsala, Sweden
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27
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Verstraeten A, Alaerts M, Van Laer L, Loeys B. Marfan Syndrome and Related Disorders: 25 Years of Gene Discovery. Hum Mutat 2016; 37:524-31. [DOI: 10.1002/humu.22977] [Citation(s) in RCA: 112] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 02/09/2016] [Accepted: 02/18/2016] [Indexed: 12/22/2022]
Affiliation(s)
- Aline Verstraeten
- Center of Medical Genetics, Faculty of Medicine and Health Sciences; University of Antwerp and Antwerp University Hospital; Antwerp Belgium
| | - Maaike Alaerts
- Center of Medical Genetics, Faculty of Medicine and Health Sciences; University of Antwerp and Antwerp University Hospital; Antwerp Belgium
| | - Lut Van Laer
- Center of Medical Genetics, Faculty of Medicine and Health Sciences; University of Antwerp and Antwerp University Hospital; Antwerp Belgium
| | - Bart Loeys
- Center of Medical Genetics, Faculty of Medicine and Health Sciences; University of Antwerp and Antwerp University Hospital; Antwerp Belgium
- Department of Human Genetics; Radboud University Nijmegen Medical Center; Nijmegen The Netherlands
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28
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Takeda N, Yagi H, Hara H, Fujiwara T, Fujita D, Nawata K, Inuzuka R, Taniguchi Y, Harada M, Toko H, Akazawa H, Komuro I. Pathophysiology and Management of Cardiovascular Manifestations in Marfan and Loeys–Dietz Syndromes. Int Heart J 2016; 57:271-7. [DOI: 10.1536/ihj.16-094] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Norifumi Takeda
- Department of Cardiovascular Medicine, The University of Tokyo Hospital
| | - Hiroki Yagi
- Department of Cardiovascular Medicine, The University of Tokyo Hospital
| | - Hironori Hara
- Department of Cardiovascular Medicine, The University of Tokyo Hospital
| | - Takayuki Fujiwara
- Department of Cardiovascular Medicine, The University of Tokyo Hospital
| | - Daishi Fujita
- Department of Cardiovascular Medicine, The University of Tokyo Hospital
| | - Kan Nawata
- Department of Cardiovascular Surgery, The University of Tokyo Hospital
| | - Ryo Inuzuka
- Department of Pediatrics, The University of Tokyo Hospital
| | - Yuki Taniguchi
- Department of Orthopedic Surgery, The University of Tokyo Hospital
| | - Mutsuo Harada
- Department of Cardiovascular Medicine, The University of Tokyo Hospital
| | - Haruhiro Toko
- Department of Cardiovascular Medicine, The University of Tokyo Hospital
| | - Hiroshi Akazawa
- Department of Cardiovascular Medicine, The University of Tokyo Hospital
| | - Issei Komuro
- Department of Cardiovascular Medicine, The University of Tokyo Hospital
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29
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Hu JH, Wei H, Jaffe M, Airhart N, Du L, Angelov SN, Yan J, Allen JK, Kang I, Wight TN, Fox K, Smith A, Enstrom R, Dichek DA. Postnatal Deletion of the Type II Transforming Growth Factor-β Receptor in Smooth Muscle Cells Causes Severe Aortopathy in Mice. Arterioscler Thromb Vasc Biol 2015; 35:2647-56. [PMID: 26494233 DOI: 10.1161/atvbaha.115.306573] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2014] [Accepted: 10/14/2015] [Indexed: 01/18/2023]
Abstract
OBJECTIVE Prenatal deletion of the type II transforming growth factor-β (TGF-β) receptor (TBRII) prevents normal vascular morphogenesis and smooth muscle cell (SMC) differentiation, causing embryonic death. The role of TBRII in adult SMC is less well studied. Clarification of this role has important clinical implications because TBRII deletion should ablate TGF-β signaling, and blockade of TGF-β signaling is envisioned as a treatment for human aortopathies. We hypothesized that postnatal loss of SMC TBRII would cause aortopathy. APPROACH AND RESULTS We generated mice with either of 2 tamoxifen-inducible SMC-specific Cre (SMC-CreER(T2)) alleles and homozygous floxed Tgfbr2 alleles. Mice were injected with tamoxifen, and their aortas examined 4 and 14 weeks later. Both SMC-CreER(T2) alleles efficiently and specifically rearranged a floxed reporter gene and efficiently rearranged a floxed Tgfbr2 allele, resulting in loss of aortic medial TBRII protein. Loss of SMC TBRII caused severe aortopathy, including hemorrhage, ulceration, dissection, dilation, accumulation of macrophage markers, elastolysis, abnormal proteoglycan accumulation, and aberrant SMC gene expression. All areas of the aorta were affected, with the most severe pathology in the ascending aorta. Cre-mediated loss of SMC TBRII in vitro ablated both canonical and noncanonical TGF-β signaling and reproduced some of the gene expression abnormalities detected in vivo. CONCLUSIONS SMC TBRII plays a critical role in maintaining postnatal aortic homeostasis. Loss of SMC TBRII disrupts TGF-β signaling, acutely alters SMC gene expression, and rapidly results in severe and durable aortopathy. These results suggest that pharmacological blockade of TGF-β signaling in humans could cause aortic disease rather than prevent it.
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Affiliation(s)
- Jie Hong Hu
- From the Department of Medicine, University of Washington School of Medicine, Seattle, WA (J.H.H., H.W., M.J., N.A., L.D., S.N.A., J.Y., J.K.A., K.F., A.S., R.E., D.A.D); and the Matrix Biology Program at the Benaroya Research Institute, Seattle, WA (I.K., T.N.W.)
| | - Hao Wei
- From the Department of Medicine, University of Washington School of Medicine, Seattle, WA (J.H.H., H.W., M.J., N.A., L.D., S.N.A., J.Y., J.K.A., K.F., A.S., R.E., D.A.D); and the Matrix Biology Program at the Benaroya Research Institute, Seattle, WA (I.K., T.N.W.)
| | - Mia Jaffe
- From the Department of Medicine, University of Washington School of Medicine, Seattle, WA (J.H.H., H.W., M.J., N.A., L.D., S.N.A., J.Y., J.K.A., K.F., A.S., R.E., D.A.D); and the Matrix Biology Program at the Benaroya Research Institute, Seattle, WA (I.K., T.N.W.)
| | - Nathan Airhart
- From the Department of Medicine, University of Washington School of Medicine, Seattle, WA (J.H.H., H.W., M.J., N.A., L.D., S.N.A., J.Y., J.K.A., K.F., A.S., R.E., D.A.D); and the Matrix Biology Program at the Benaroya Research Institute, Seattle, WA (I.K., T.N.W.)
| | - Liang Du
- From the Department of Medicine, University of Washington School of Medicine, Seattle, WA (J.H.H., H.W., M.J., N.A., L.D., S.N.A., J.Y., J.K.A., K.F., A.S., R.E., D.A.D); and the Matrix Biology Program at the Benaroya Research Institute, Seattle, WA (I.K., T.N.W.)
| | - Stoyan N Angelov
- From the Department of Medicine, University of Washington School of Medicine, Seattle, WA (J.H.H., H.W., M.J., N.A., L.D., S.N.A., J.Y., J.K.A., K.F., A.S., R.E., D.A.D); and the Matrix Biology Program at the Benaroya Research Institute, Seattle, WA (I.K., T.N.W.)
| | - James Yan
- From the Department of Medicine, University of Washington School of Medicine, Seattle, WA (J.H.H., H.W., M.J., N.A., L.D., S.N.A., J.Y., J.K.A., K.F., A.S., R.E., D.A.D); and the Matrix Biology Program at the Benaroya Research Institute, Seattle, WA (I.K., T.N.W.)
| | - Julie K Allen
- From the Department of Medicine, University of Washington School of Medicine, Seattle, WA (J.H.H., H.W., M.J., N.A., L.D., S.N.A., J.Y., J.K.A., K.F., A.S., R.E., D.A.D); and the Matrix Biology Program at the Benaroya Research Institute, Seattle, WA (I.K., T.N.W.)
| | - Inkyung Kang
- From the Department of Medicine, University of Washington School of Medicine, Seattle, WA (J.H.H., H.W., M.J., N.A., L.D., S.N.A., J.Y., J.K.A., K.F., A.S., R.E., D.A.D); and the Matrix Biology Program at the Benaroya Research Institute, Seattle, WA (I.K., T.N.W.)
| | - Thomas N Wight
- From the Department of Medicine, University of Washington School of Medicine, Seattle, WA (J.H.H., H.W., M.J., N.A., L.D., S.N.A., J.Y., J.K.A., K.F., A.S., R.E., D.A.D); and the Matrix Biology Program at the Benaroya Research Institute, Seattle, WA (I.K., T.N.W.)
| | - Kate Fox
- From the Department of Medicine, University of Washington School of Medicine, Seattle, WA (J.H.H., H.W., M.J., N.A., L.D., S.N.A., J.Y., J.K.A., K.F., A.S., R.E., D.A.D); and the Matrix Biology Program at the Benaroya Research Institute, Seattle, WA (I.K., T.N.W.)
| | - Alexandra Smith
- From the Department of Medicine, University of Washington School of Medicine, Seattle, WA (J.H.H., H.W., M.J., N.A., L.D., S.N.A., J.Y., J.K.A., K.F., A.S., R.E., D.A.D); and the Matrix Biology Program at the Benaroya Research Institute, Seattle, WA (I.K., T.N.W.)
| | - Rachel Enstrom
- From the Department of Medicine, University of Washington School of Medicine, Seattle, WA (J.H.H., H.W., M.J., N.A., L.D., S.N.A., J.Y., J.K.A., K.F., A.S., R.E., D.A.D); and the Matrix Biology Program at the Benaroya Research Institute, Seattle, WA (I.K., T.N.W.)
| | - David A Dichek
- From the Department of Medicine, University of Washington School of Medicine, Seattle, WA (J.H.H., H.W., M.J., N.A., L.D., S.N.A., J.Y., J.K.A., K.F., A.S., R.E., D.A.D); and the Matrix Biology Program at the Benaroya Research Institute, Seattle, WA (I.K., T.N.W.).
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30
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Chambers JE, Dalton LE, Subramanian DN, Gooptu B, Balan A, Park SM, Holden S, Marciniak SJ. Spontaneous pneumothorax can be associated with TGFBR2 mutation. Eur Respir J 2015; 46:1832-5. [PMID: 26493799 DOI: 10.1183/13993003.00952-2015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 08/24/2015] [Indexed: 11/05/2022]
Affiliation(s)
- Joseph E Chambers
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK These authors contributed equally
| | - Lucy E Dalton
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK These authors contributed equally
| | - Deepak N Subramanian
- Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK These authors contributed equally
| | - Bibek Gooptu
- School of Crystallography, ISMB, Birkbeck College, University of London, London, UK
| | - Anu Balan
- Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Soo-Mi Park
- Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Simon Holden
- Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Stefan J Marciniak
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
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31
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Dewan AK, Tomlinson RE, Mitchell S, Goh BC, Yung RM, Kumar S, Tan EW, Faugere MC, Dietz HC, Clemens TL, Sponseller PD. Dysregulated TGF-β signaling alters bone microstructure in a mouse model of Loeys-Dietz syndrome. J Orthop Res 2015; 33:1447-54. [PMID: 26173585 DOI: 10.1002/jor.22920] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Accepted: 04/07/2015] [Indexed: 02/04/2023]
Abstract
Loeys-Dietz syndrome (LDS) is a connective tissue disorder characterized by vascular and skeletal abnormalities resembling Marfan syndrome, including a predisposition for pathologic fracture. LDS is caused by heterozygous mutations in the genes encoding transforming growth factor-β (TGF-β) type 1 and type 2 receptors. In this study, we characterized the skeletal phenotype of mice carrying a mutation in the TGF-β type 2 receptor associated with severe LDS in humans. Cortical bone in LDS mice showed significantly reduced tissue area, bone area, and cortical thickness with increased eccentricity. However, no significant differences in trabecular bone volume were observed. Dynamic histomorphometry performed in calcein-labeled mice showed decreased mineral apposition rates in cortical and trabecular bone with normal numbers of osteoblasts and osteoclasts. Mechanical testing of femurs by three-point bending revealed reduced femoral strength and fracture resistance. In vitro, osteoblasts from LDS mice demonstrated increased mineralization with enhanced expression of osteoblast differentiation markers compared with control cells. These changes were associated with impaired TGF-β1-induced Smad2 and Erk1/2 phosphorylation and upregulated TGF-β1 ligand mRNA expression, compatible with G357W as a loss-of-function mutation in the TGF-β type 2 receptor. Paradoxically, phosphorylated Smad2/3 in cortical osteocytes measured by immunohistochemistry was increased relative to controls, possibly suggesting the cross-activation of TGF-β-related receptors. The skeletal phenotype observed in the LDS mouse closely resembles the principal structural features of bone in humans with LDS and establishes this mouse as a valid in vivo model for further investigation of TGF-β receptor signaling in bone.
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Affiliation(s)
- Ashvin K Dewan
- Department of Orthopaedic Surgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Ryan E Tomlinson
- Department of Orthopaedic Surgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Stuart Mitchell
- Department of Orthopaedic Surgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Brian C Goh
- Department of Orthopaedic Surgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Rachel M Yung
- Department of Orthopaedic Surgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Sarvesh Kumar
- Department of Orthopaedic Surgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Eric W Tan
- Department of Orthopaedic Surgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | | | - Harry C Dietz
- McKusick-Nathans Institute of Genetic Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland.,Howard Hughes Medical Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Thomas L Clemens
- Department of Orthopaedic Surgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland.,Baltimore Veterans Administration Medical Center, Baltimore, Maryland
| | - Paul D Sponseller
- Department of Orthopaedic Surgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland
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Abstract
Gene identification in human aortic aneurysm conditions is proceeding at a rapid pace and the integration of pathogenesis-based management strategies in clinical practice is an emerging reality. Human genetic alterations causing aneurysm involve diverse gene products including constituents of the extracellular matrix, cell surface receptors, intracellular signaling molecules, and elements of the contractile cytoskeleton. Animal modeling experiments and human genetic discoveries have extensively implicated the transforming growth factor-β (TGF-β) cytokine-signaling cascade in aneurysm progression, but mechanistic links between many gene products remain obscure. This chapter will integrate human genetic alterations associated with aortic aneurysm with current basic research findings in an attempt to form a reconciling if not unifying model for hereditary aortic aneurysm.
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Affiliation(s)
- Mark E Lindsay
- Massachusetts General Hospital Thoracic Aortic Center, Departments of Medicine and Pediatrics, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114
| | - Harry C Dietz
- McKusick-Nathans Institute of Genetic Medicine, Departments of Pediatrics, Medicine, and Molecular Biology & Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205 Howard Hughes Medical Institute, Baltimore, Maryland 21205
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33
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Current evidence and insights about genetics in thoracic aorta disease. ScientificWorldJournal 2013; 2013:962097. [PMID: 24453931 PMCID: PMC3886571 DOI: 10.1155/2013/962097] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Accepted: 10/08/2013] [Indexed: 12/20/2022] Open
Abstract
Thoracic aortic aneurysms have been historically considered to be caused by etiologic factors similar to those implied in abdominal aortic aneurysms. However, during the past decade, there has been increasing evidence that almost 20% of thoracic aortic aneurysms may be associated with a genetic disease, often within a syndromic or familial disorder. Moreover, the presence of congenital anomalies, such as bicuspid aortic valve, may have a unique common genetic underlying cause. Finally, also sporadic forms have been found to be potentially associated with genetic disorders, as highlighted by the analysis of rare variants and expression of specific microRNAs. We therefore sought to perform a comprehensive review of the role of genetic causes in the development of thoracic aortic aneurysms, by analyzing in detail the current evidence of genetic alterations in syndromes such as Marfan, Loeys-Dietz, and Ehler-Danlos, familial or sporadic forms, or forms associated with bicuspid aortic valve.
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34
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Gallo EM, Loch DC, Habashi JP, Calderon JF, Chen Y, Bedja D, van Erp C, Gerber EE, Parker SJ, Sauls K, Judge DP, Cooke SK, Lindsay ME, Rouf R, Myers L, ap Rhys CM, Kent KC, Norris RA, Huso DL, Dietz HC. Angiotensin II-dependent TGF-β signaling contributes to Loeys-Dietz syndrome vascular pathogenesis. J Clin Invest 2013; 124:448-60. [PMID: 24355923 DOI: 10.1172/jci69666] [Citation(s) in RCA: 182] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Accepted: 10/10/2013] [Indexed: 12/19/2022] Open
Abstract
Loeys-Dietz syndrome (LDS) is a connective tissue disorder that is characterized by a high risk for aneurysm and dissection throughout the arterial tree and phenotypically resembles Marfan syndrome. LDS is caused by heterozygous missense mutations in either TGF-β receptor gene (TGFBR1 or TGFBR2), which are predicted to result in diminished TGF-β signaling; however, aortic surgical samples from patients show evidence of paradoxically increased TGF-β signaling. We generated 2 knockin mouse strains with LDS mutations in either Tgfbr1 or Tgfbr2 and a transgenic mouse overexpressing mutant Tgfbr2. Knockin and transgenic mice, but not haploinsufficient animals, recapitulated the LDS phenotype. While heterozygous mutant cells had diminished signaling in response to exogenous TGF-β in vitro, they maintained normal levels of Smad2 phosphorylation under steady-state culture conditions, suggesting a chronic compensation. Analysis of TGF-β signaling in the aortic wall in vivo revealed progressive upregulation of Smad2 phosphorylation and TGF-β target gene output, which paralleled worsening of aneurysm pathology and coincided with upregulation of TGF-β1 ligand expression. Importantly, suppression of Smad2 phosphorylation and TGF-β1 expression correlated with the therapeutic efficacy of the angiotensin II type 1 receptor antagonist losartan. Together, these data suggest that increased TGF-β signaling contributes to postnatal aneurysm progression in LDS.
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MESH Headings
- Angiotensin II/physiology
- Angiotensin II Type 1 Receptor Blockers/therapeutic use
- Animals
- Aorta/pathology
- Aortic Aneurysm/metabolism
- Aortic Aneurysm/prevention & control
- Cells, Cultured
- Disease Progression
- Female
- Haploinsufficiency
- Humans
- Loeys-Dietz Syndrome/drug therapy
- Loeys-Dietz Syndrome/metabolism
- Loeys-Dietz Syndrome/pathology
- Losartan/therapeutic use
- Mice
- Mice, 129 Strain
- Mice, Inbred C57BL
- Mice, Transgenic
- Mutation, Missense
- Myocytes, Smooth Muscle/metabolism
- Phenotype
- Protein Serine-Threonine Kinases/genetics
- Protein Serine-Threonine Kinases/metabolism
- Receptor, Transforming Growth Factor-beta Type I
- Receptor, Transforming Growth Factor-beta Type II
- Receptors, Transforming Growth Factor beta/genetics
- Receptors, Transforming Growth Factor beta/metabolism
- Signal Transduction
- Smad2 Protein/metabolism
- Transforming Growth Factor beta/metabolism
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35
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Felgentreff K, Siepe M, Kotthoff S, von Kodolitsch Y, Schachtrup K, Notarangelo LD, Walter JE, Ehl S. Severe eczema and Hyper-IgE in Loeys-Dietz-syndrome - contribution to new findings of immune dysregulation in connective tissue disorders. Clin Immunol 2013; 150:43-50. [PMID: 24333532 DOI: 10.1016/j.clim.2013.11.008] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Revised: 11/06/2013] [Accepted: 11/10/2013] [Indexed: 01/09/2023]
Abstract
Loeys-Dietz syndrome (LDS) is a connective tissue disorder caused by monoallelic mutations in TGFBR1 and TGFBR2, which encode for subunits of the transforming growth factor beta (TGFβ) receptor. Affected patients are identified by vascular aneurysms with tortuosity and distinct morphological presentations similar to Marfan syndrome; however, an additional predisposition towards asthma and allergy has recently been found. We describe two patients with a novel missense mutation in TGFBR1 presenting with highly elevated levels of IgE and severe eczema similar to autosomal-dominant Hyper-IgE syndrome (HIES). Mild allergic manifestations with normal up to moderately increased IgE were observed in 3 out of 6 additional LDS patients. A comparison of this cohort with 4 HIES patients illustrates the significant overlap of both syndromes including eczema and elevated IgE as well as skeletal and connective tissue manifestations.
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Affiliation(s)
- Kerstin Felgentreff
- Division of Immunology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA; Center of Chronic Immunodeficiency, University Hospital Freiburg, Freiburg, Germany; The Manton Center for Orphan Disease Research, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
| | - Matthias Siepe
- University Heart Center Freiburg Bad Krozingen, Freiburg, Germany
| | - Stefan Kotthoff
- Department of Pediatric Cardiology, University Hospital Münster, Münster, Germany
| | | | - Kristina Schachtrup
- Center of Chronic Immunodeficiency, University Hospital Freiburg, Freiburg, Germany
| | - Luigi D Notarangelo
- Division of Immunology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA; Harvard Stem Cell Institute, Harvard Medical School, Boston, MA, USA; The Manton Center for Orphan Disease Research, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Jolan E Walter
- Division of Allergy and Immunology, Massachusetts General Hospital, Boston, MA, USA
| | - Stephan Ehl
- Center of Chronic Immunodeficiency, University Hospital Freiburg, Freiburg, Germany.
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36
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Jakobsson L, van Meeteren LA. Transforming growth factor β family members in regulation of vascular function: in the light of vascular conditional knockouts. Exp Cell Res 2013; 319:1264-70. [PMID: 23454603 DOI: 10.1016/j.yexcr.2013.02.015] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Revised: 02/12/2013] [Accepted: 02/13/2013] [Indexed: 10/27/2022]
Abstract
Blood vessels are composed of endothelial cells, mural cells (smooth muscle cells and pericytes) and their shared basement membrane. During embryonic development a multitude of signaling components orchestrate the formation of new vessels. The process is highly dependent on correct dosage, spacing and timing of these signaling molecules. As vessels mature some cascades remain active, albeit at very low levels, and may be reactivated upon demand. Members of the Transforming growth factor β (TGF-β) protein family are strongly engaged in developmental angiogenesis but are also regulators of vascular integrity in the adult. In humans various genetic alterations within this protein family cause vascular disorders, involving disintegration of vascular integrity. Here we summarize and discuss recent data gathered from conditional and endothelial cell specific genetic loss-of-function of members of the TGF-β family in the mouse.
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Affiliation(s)
- Lars Jakobsson
- Department of Medical Biochemistry and Biophysics, Division of Vascular Biology, Karolinska Institutet, SE-171 77 Stockholm, Sweden.
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37
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Agota A, Agg B, Benke K, Joó JG, Langmár Z, Marosi K, Lelovics Z, Lelelovics Z, Deé K, Nagy P, Köles B, Horváth E, Crespo Z, Szabolcs Z, Nagy ZB. [The establishment of the Marfan syndrome biobank in Hungary]. Orv Hetil 2012; 153:296-302. [PMID: 22330841 DOI: 10.1556/oh.2012.29295] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
UNLABELLED Marfan syndrome is a genetic disorder of the connective tissue, which affects approximately 2000-3000 individuals in Hungary. Given its multi-systemic manifestations, this disorder is often difficult to diagnose. To date, the National Marfan Register system contains approximately 250 cases, and this number is dynamically increasing. AIMS Collection of data from biological samples, clinical parameters, and lifestyle factors in Hungarian patients with Marfan syndrome. METHODS In terms of the criteria used for selection, those cases were chosen where the disorder could be clearly diagnosed on the basis of the patients' cardiovascular and systemic symptoms, as well as of their family history, in line with the guidelines set by the Revised Ghent Nosology. RESULTS For the purposes of developing the biobank used for the research, 102 cases were selected from the Marfan Register (cDNA from 55 patients, genomic DNA and serum from 102 patients). In addition to the samples, data have been obtained by using internationally validated surveys to further examine the role of physical activity, nutrition and various psychological factors. CONCLUSIONS The establishment of the Marfan Biobank enables scientists to effectively carry out research based on genetic, gene-expression and protein analysis. The biobank also provides new opportunities to study Hungarian patients with Marfan syndrome.
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38
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Ben Amor IM, Edouard T, Glorieux FH, Chabot G, Tischkowitz M, Roschger P, Klaushofer K, Rauch F. Low bone mass and high material bone density in two patients with Loeys-Dietz syndrome caused by transforming growth factor beta receptor 2 mutations. J Bone Miner Res 2012; 27:713-8. [PMID: 22095581 DOI: 10.1002/jbmr.1470] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Loeys-Dietz syndrome (LDS) is a rare autosomal-dominant connective tissue disorder caused by heterozygous mutations in the genes encoding transforming growth factor beta receptor 1 or 2 (TGFBR1 or TGFBR2). Although an association between LDS and osteoporosis has been reported, the skeletal phenotype regarding bone mass is not well characterized. Here, we report on two LDS patients with mutations in TGFBR2. Patient 1 was a 24-year-old man who had a total of three fractures involving the left radius, the left metacarpal, and the right femur. At the age of 14 years, lumbar spine areal bone mineral density Z-score was -4.0 and iliac bone histomorphometry showed elevated bone turnover (bone formation rate per bone surface: 91 µm³/µm²/year; age-matched control values 37 [10], mean [SD]) and mildly low trabecular bone volume per tissue volume (17.2%; age-matched control values 25.7 [5.3]). Bone mineralization density distribution (BMDD) in trabecular bone was increased (Ca(Peak) 22.70 wt% Ca; age-matched control values 21.66 [0.52]). Patient 2, a 17-year-old girl, suffered from diffuse bone pain but had not sustained fractures. At 14 years of age, her lumbar spine areal bone mineral density Z-score was -3.4. Iliac bone histomorphometry at that age confirmed low bone mass (bone volume to tissue volume 10.1%, same control values as above) and high bone turnover (bone formation rate per bone surface 70 µm³/µm²/year). BMDD in trabecular bone was significantly shifted toward increased mineralization (Ca(Peak) 22.36 wt% Ca). Thus, it appears that LDS can be associated with low bone mass and high bone turnover but increased matrix mineralization of trabecular bone.
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Affiliation(s)
- I Mouna Ben Amor
- Shriners Hospital for Children and McGill University, Montreal, Quebec, Canada
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39
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Iwata JI, Hacia JG, Suzuki A, Sanchez-Lara PA, Urata M, Chai Y. Modulation of noncanonical TGF-β signaling prevents cleft palate in Tgfbr2 mutant mice. J Clin Invest 2012; 122:873-85. [PMID: 22326956 DOI: 10.1172/jci61498] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2011] [Accepted: 01/04/2012] [Indexed: 11/17/2022] Open
Abstract
Patients with mutations in either TGF-β receptor type I (TGFBR1) or TGF-β receptor type II (TGFBR2), such as those with Loeys-Dietz syndrome, have craniofacial defects and signs of elevated TGF-β signaling. Similarly, mutations in TGF-β receptor gene family members cause craniofacial deformities, such as cleft palate, in mice. However, it is unknown whether TGF-β ligands are able to elicit signals in Tgfbr2 mutant mice. Here, we show that loss of Tgfbr2 in mouse cranial neural crest cells results in elevated expression of TGF-β2 and TGF-β receptor type III (TβRIII); activation of a TβRI/TβRIII-mediated, SMAD-independent, TRAF6/TAK1/p38 signaling pathway; and defective cell proliferation in the palatal mesenchyme. Strikingly, Tgfb2, Tgfbr1 (also known as Alk5), or Tak1 haploinsufficiency disrupted TβRI/TβRIII-mediated signaling and rescued craniofacial deformities in Tgfbr2 mutant mice, indicating that activation of this noncanonical TGF-β signaling pathway was responsible for craniofacial malformations in Tgfbr2 mutant mice. Thus, modulation of TGF-β signaling may be beneficial for the prevention of congenital craniofacial birth defects.
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Affiliation(s)
- Jun-ichi Iwata
- Center for Craniofacial Molecular Biology, Ostrow School of Dentistry, University of Southern California, Los Angeles, California 90033, USA
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40
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Pardali E, Ten Dijke P. TGFβ signaling and cardiovascular diseases. Int J Biol Sci 2012; 8:195-213. [PMID: 22253564 PMCID: PMC3258560 DOI: 10.7150/ijbs.3805] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Accepted: 12/01/2011] [Indexed: 12/19/2022] Open
Abstract
Transforming growth factor β (TGFβ) family members are involved in a wide range of diverse functions and play key roles in embryogenesis, development and tissue homeostasis. Perturbation of TGFβ signaling may lead to vascular and other diseases. In vitro studies have provided evidence that TGFβ family members have a wide range of diverse effects on vascular cells, which are highly dependent on cellular context. Consistent with these observations genetic studies in mice and humans showed that TGFβ family members have ambiguous effects on the function of the cardiovascular system. In this review we discuss the recent advances on TGFβ signaling in (cardio)vascular diseases, and describe the value of TGFβ signaling as both a disease marker and therapeutic target for (cardio)vascular diseases.
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Affiliation(s)
- Evangelia Pardali
- Department of Cardiology and Angiology, University Hospital Münster, Münster, Germany.
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41
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Horbelt D, Denkis A, Knaus P. A portrait of Transforming Growth Factor β superfamily signalling: Background matters. Int J Biochem Cell Biol 2011; 44:469-74. [PMID: 22226817 DOI: 10.1016/j.biocel.2011.12.013] [Citation(s) in RCA: 136] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Revised: 12/20/2011] [Accepted: 12/22/2011] [Indexed: 12/21/2022]
Abstract
Ligands of the Transforming Growth Factor β superfamily like Transforming Growth Factor β and Bone Morphogenetic Proteins govern developmental processes and regulate adult homeostasis by controlling cellular proliferation, survival, differentiation and migration. Aberrant signalling activity is associated with human disorders such as cancer, cardiovascular, musculoskeletal, or fibrotic disease. Upon binding to specific sets of cognate cell surface receptors, family members induce highly similar pathways which include canonical SMAD dependent signalling as well as pathways without direct involvement of SMAD proteins, which activate signalling molecules like mitogen-activated protein kinases or small GTPases. The diverse ligand functionalities are achieved through regulation and modulation of the pathways at all levels, resulting in a highly quantitative and context sensitive signal integration reflecting the cellular state and background. Strategies to target Transforming Growth Factor β or Bone Morphogenetic Protein pathways have been developed on the basis of our current understanding and have proven a highly beneficial potential.
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Affiliation(s)
- Daniel Horbelt
- Institute for Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany
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42
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Kalra VB, Gilbert JW, Malhotra A. Loeys-Dietz syndrome: cardiovascular, neuroradiological and musculoskeletal imaging findings. Pediatr Radiol 2011; 41:1495-504; quiz 1616. [PMID: 21785848 DOI: 10.1007/s00247-011-2195-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2011] [Revised: 06/04/2011] [Accepted: 06/10/2011] [Indexed: 11/29/2022]
Abstract
Loeys-Dietz syndrome (LDS) is an increasingly recognized autosomal-dominant connective tissue disorder with distinctive radiological manifestations, including arterial tortuosity/aneurysms, craniofacial malformations and skeletal abnormalities. LDS exhibits a more aggressive course than similar disorders, such as Marfan or the vascular subtype of Ehlers-Danlos syndrome, with morbidity and mortality typically resulting from complications of aortic/arterial dissections. Early diagnosis, short-interval follow-up imaging and prophylactic surgical intervention are essential in preventing catastrophic cardiovascular complications. This review focuses on the cardiovascular, neuroradiological and musculoskeletal imaging findings in this disorder and recommendations for follow-up imaging.
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Affiliation(s)
- Vivek B Kalra
- Department of Diagnostic Radiology, Yale-New Haven Medical Center, Box 208042, Tompkins East 2, 333 Cedar St., New Haven, CT 06520-8042, USA
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43
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Halushka MK. Single gene disorders of the aortic wall. Cardiovasc Pathol 2011; 21:240-4. [PMID: 22036072 DOI: 10.1016/j.carpath.2011.09.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Revised: 08/08/2011] [Accepted: 09/13/2011] [Indexed: 01/15/2023] Open
Abstract
Genetic diseases that affect the vasculature primarily affect the aortic root and ascending aorta. These conditions lead to aortic root dilatation, which, if not treated, will result in dissection and death. Often, aortic disease is just one manifestation of a syndrome with diverse findings. Some of these diseases were described over 100 years ago based on physical manifestations, and their causative genes are among the first described Mendelian causes of cardiovascular disease. Within the pediatric and young adult population, there are over 15 causes of ascending aortic disease. Previously, these diverse diseases, along with their histopathology, have been extensively characterized. Most genetic causes of root aneurysm are extremely rare. Amongst these, five diseases are relatively common with known genetic mutations for which pathologists should be familiar. These are Marfan syndrome, vascular Ehlers-Danlos syndrome, Loeys-Dietz syndrome, Turner syndrome, and familial thoracic aneurysm and dissection. This review will focus on these important causes of genetic aortic disease. The aim is to briefly describe the historical record and physical manifestations and then focus on cardiovascular complications, the causative genes, and current research into these entities.
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Affiliation(s)
- Marc K Halushka
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
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44
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Doetschman T, Barnett JV, Runyan RB, Camenisch TD, Heimark RL, Granzier HL, Conway SJ, Azhar M. Transforming growth factor beta signaling in adult cardiovascular diseases and repair. Cell Tissue Res 2011; 347:203-23. [PMID: 21953136 DOI: 10.1007/s00441-011-1241-3] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2011] [Accepted: 09/02/2011] [Indexed: 01/15/2023]
Abstract
The majority of children with congenital heart disease now live into adulthood due to the remarkable surgical and medical advances that have taken place over the past half century. Because of this, adults now represent the largest age group with adult cardiovascular diseases. It includes patients with heart diseases that were not detected or not treated during childhood, those whose defects were surgically corrected but now need revision due to maladaptive responses to the procedure, those with exercise problems and those with age-related degenerative diseases. Because adult cardiovascular diseases in this population are relatively new, they are not well understood. It is therefore necessary to understand the molecular and physiological pathways involved if we are to improve treatments. Since there is a developmental basis to adult cardiovascular disease, transforming growth factor beta (TGFβ) signaling pathways that are essential for proper cardiovascular development may also play critical roles in the homeostatic, repair and stress response processes involved in adult cardiovascular diseases. Consequently, we have chosen to summarize the current information on a subset of TGFβ ligand and receptor genes and related effector genes that, when dysregulated, are known to lead to cardiovascular diseases and adult cardiovascular deficiencies and/or pathologies. A better understanding of the TGFβ signaling network in cardiovascular disease and repair will impact genetic and physiologic investigations of cardiovascular diseases in elderly patients and lead to an improvement in clinical interventions.
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45
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Campbell IM, Kolodziejska KE, Quach MM, Wolf VL, Cheung SW, Lalani SR, Ramocki MB, Stankiewicz P. TGFBR2 deletion in a 20-month-old female with developmental delay and microcephaly. Am J Med Genet A 2011; 155A:1442-7. [PMID: 21567932 DOI: 10.1002/ajmg.a.34015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Accepted: 03/07/2011] [Indexed: 11/07/2022]
Abstract
To date, over 70 mutations in the TGFBR2 gene have been reported in patients with Loeys-Dietz syndrome (LDS), Marfan syndrome type 2 (MFS2), or other hereditary thoracic aortic aneurysms and dissections. Whereas almost all of mutations analyzed thus far are predicted to disrupt the constitutively active C-terminal serine/threonine kinase domain of TGFBR2, mounting evidence suggests that the molecular mechanism underlying these diseases is more complex than simple haploinsufficiency. Using exon-targeted oligonucleotide array comparative genomic hybridization, we identified an ∼896 kb deletion of TGFBR2 in a 20-month-old female with microcephaly and global developmental delay, but no stigmata of LDS. FISH analysis showed no evidence of this deletion in the parental peripheral blood samples; however, somatic mosaicism was detected using PCR in the paternal DNA from peripheral blood lymphocytes and lymphoblasts. Our data suggest that TGFBR2 haploinsufficiency may cause a phenotype, which is distinct from LDS. Moreover, we propose that somatic mosaicism below the detection threshold of FISH analysis in asymptomatic parents of children with genomic disorders may be more common than previously recognized.
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Affiliation(s)
- Ian M Campbell
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
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46
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Moltzer E, Essers J, van Esch JHM, Roos-Hesselink JW, Danser AHJ. The role of the renin-angiotensin system in thoracic aortic aneurysms: clinical implications. Pharmacol Ther 2011; 131:50-60. [PMID: 21504760 DOI: 10.1016/j.pharmthera.2011.04.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2011] [Accepted: 03/26/2011] [Indexed: 01/06/2023]
Abstract
Thoracic aortic aneurysms (TAAs) are a potential life-threatening disease with limited pharmacological treatment options. Current treatment options are aimed at lowering aortic hemodynamic stress, predominantly with β-adrenoceptor blockers. Increasing evidence supports a role for the renin-angiotensin system (RAS) in aneurysm development. RAS blockade would not only lower blood pressure, but might also target the molecular pathways involved in aneurysm formation, in particular the transforming growth factor-β and extracellular signal-regulated kinase 1/2 pathways. Indeed, the angiotensin II type 1 (AT₁) receptor blocker losartan was effective in lowering aortic root growth in mice and patients with Marfan's syndrome. RAS inhibition (currently possible at 3 levels, i.e. renin, ACE and the AT₁ receptor) is always accompanied by a rise in renin due to interference with the negative feedback loop between renin and angiotensin II. Only during AT₁ receptor blockade will this result in stimulation of the non-blocked angiotensin II type 2 (AT₂) receptor. This review summarizes the clinical aspects of TAAs, provides an overview of the current mouse models for TAAs, and focuses on the RAS as a new target for TAA treatment, discussing in particular the possibility that AT₂ receptor stimulation might be crucial in this regard. If true, this would imply that AT₁ receptor blockers (and not ACE inhibitors or renin inhibitors) should be the preferred treatment option for TAAs.
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Affiliation(s)
- Els Moltzer
- Division of Vascular Medicine and Pharmacology, Department of Internal Medicine, Erasmus MC, Rotterdam, The Netherlands
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