101
|
Couto JA, Huang AY, Konczyk DJ, Goss JA, Fishman SJ, Mulliken JB, Warman ML, Greene AK. Somatic MAP2K1 Mutations Are Associated with Extracranial Arteriovenous Malformation. Am J Hum Genet 2017; 100:546-554. [PMID: 28190454 DOI: 10.1016/j.ajhg.2017.01.018] [Citation(s) in RCA: 173] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 01/06/2017] [Indexed: 01/09/2023] Open
Abstract
Arteriovenous malformation (AVM) is a fast-flow, congenital vascular anomaly that may arise anywhere in the body. AVMs typically progress, causing destruction of surrounding tissue and, sometimes, cardiac overload. AVMs are difficult to control; they often re-expand after embolization or resection, and pharmacologic therapy is unavailable. We studied extracranial AVMs in order to identify their biological basis. We performed whole-exome sequencing (WES) and whole-genome sequencing (WGS) on AVM tissue from affected individuals. Endothelial cells were separated from non-endothelial cells by immune-affinity purification. We used droplet digital PCR (ddPCR) to confirm mutations found by WES and WGS, to determine whether mutant alleles were enriched in endothelial or non-endothelial cells, and to screen additional AVM specimens. In seven of ten specimens, WES and WGS detected and ddPCR confirmed somatic mutations in mitogen activated protein kinase kinase 1 (MAP2K1), the gene that encodes MAP-extracellular signal-regulated kinase 1 (MEK1). Mutant alleles were enriched in endothelial cells and were not present in blood or saliva. 9 of 15 additional AVM specimens contained mutant MAP2K1 alleles. Mutations were missense or small in-frame deletions that affect amino acid residues within or adjacent to the protein's negative regulatory domain. Several of these mutations have been found in cancers and shown to increase MEK1 activity. In summary, somatic mutations in MAP2K1 are a common cause of extracranial AVM. The likely mechanism is endothelial cell dysfunction due to increased MEK1 activity. MEK1 inhibitors, which are approved to treat several forms of cancer, are potential therapeutic agents for individuals with extracranial AVM.
Collapse
|
102
|
Huang L, Couto JA, Pinto A, Alexandrescu S, Madsen JR, Greene AK, Sahin M, Bischoff J. Somatic GNAQ Mutation is Enriched in Brain Endothelial Cells in Sturge-Weber Syndrome. Pediatr Neurol 2017; 67:59-63. [PMID: 27919468 PMCID: PMC5303551 DOI: 10.1016/j.pediatrneurol.2016.10.010] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 10/11/2016] [Accepted: 10/14/2016] [Indexed: 02/08/2023]
Abstract
BACKGROUND Sturge-Weber syndrome (SWS) is a rare congenital neurocutaneous disorder characterized by facial and extracraniofacial capillary malformations and capillary-venule malformations in the leptomeninges. A somatic mosaic mutation in GNAQ (c.548G>A; p.R183Q) was found in SWS brain and skin capillary malformations. Our laboratory showed endothelial cells in skin capillary malformations are enriched for the GNAQ mutation. The purpose of this study is to determine whether the GNAQ mutation is also enriched in endothelial cells in affected SWS brain. METHODS Two human SWS brain specimens were fractionated by fluorescence-activated cell sorting into hematopoietic (CD45), endothelial (CD31, VE-Cadherin, and vascular endothelial growth factor receptor 2), and perivascular (platelet-derived growth factor receptor beta) cells and cells negative for all markers. The sorted cell populations were analyzed for GNAQ p.R183Q mutation by droplet digital polymerase chain reaction. SWS patient-derived brain endothelial cells were selected by anti-CD31-coated magnetic beads and cultured in endothelial growth medium in vitro. RESULTS The GNAQ p.R183Q mutation was present in brain endothelial cells in two SWS specimens, with mutant allelic frequencies of 34.7% and 24.0%. Cells negative for all markers also harbored the GNAQ mutation. The mutant allelic frequencies in these unidentified cells were 9.2% and 8.4%. SWS patient-derived brain endothelial cells with mutant allelic frequencies of 14.7% and 21% survived and proliferated in vitro. CONCLUSIONS Our study provides evidence that GNAQ p.R183Q mutation is enriched in endothelial cells in SWS brain lesions and thereby reveals endothelial cells as a source of aberrant Gαq signaling. This will help to understand the pathophysiology of SWS, to discover biomarkers for predicting cerebral involvement, and to develop therapeutic targets to prevent neurological impairments in SWS.
Collapse
Affiliation(s)
- Lan Huang
- Vascular Biology Program, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115,Department of Surgery, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115
| | - Javier A. Couto
- Department of Plastic and Oral Surgery, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115
| | - Anna Pinto
- Department of Neurology, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115
| | - Sanda Alexandrescu
- Department of Pathology, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115
| | - Joseph R. Madsen
- Department of Neurosurgery, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115
| | - Arin K. Greene
- Department of Plastic and Oral Surgery, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115,Vascular Anomalies Center, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115
| | - Mustafa Sahin
- Department of Neurology, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115
| | - Joyce Bischoff
- Vascular Biology Program, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts; Department of Surgery, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts.
| |
Collapse
|
103
|
Couto JA, Ayturk UM, Konczyk DJ, Goss JA, Huang AY, Hann S, Reeve JL, Liang MG, Bischoff J, Warman ML, Greene AK. A somatic GNA11 mutation is associated with extremity capillary malformation and overgrowth. Angiogenesis 2017; 20:303-306. [PMID: 28120216 DOI: 10.1007/s10456-016-9538-1] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 12/24/2016] [Indexed: 11/26/2022]
Abstract
BACKGROUND Capillary malformation is a cutaneous vascular anomaly that is present at birth, darkens over time, and can cause overgrowth of tissues beneath the stain. The lesion is caused by a somatic activating mutation in GNAQ. In a previous study, we were unable to identify a GNAQ mutation in patients with a capillary malformation involving an overgrown lower extremity. We hypothesized that mutations in GNA11 or GNA14, genes closely related to GNAQ, also may cause capillary malformations. METHODS Human capillary malformation tissue obtained from 8 patients that had tested negative for GNAQ mutations were studied. Lesions involved an extremity (n = 7) or trunk (n = 1). Droplet digital PCR (ddPCR) was used to detect GNA11 or GNA14 mutant cells (p.Arg183) in the specimens. Single molecule molecular inversion probe sequencing (smMIP-seq) was performed to search for other mutations in GNA11. Mutations were validated by subcloning and sequencing amplimers. RESULTS We found a somatic GNA11 missense mutation (c.547C > T; p.Arg183Cys) in 3 patients with a diffuse capillary malformation of an extremity. Mutant allelic frequencies ranged from 0.3 to 5.0%. GNA11 or GNA14 mutations were not found in 5 affected tissues or in unaffected tissues (white blood cell DNA). CONCULSIONS GNA11 mutations are associated with extremity capillary malformations causing overgrowth. Pharmacotherapy that affects GNA11 signaling may prevent the progression of capillary malformations.
Collapse
Affiliation(s)
- Javier A Couto
- Department of Plastic and Oral Surgery, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Ugur M Ayturk
- Department of Orthopedic Surgery, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Dennis J Konczyk
- Department of Plastic and Oral Surgery, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Jeremy A Goss
- Department of Plastic and Oral Surgery, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - August Y Huang
- Department of Orthopedic Surgery, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Steve Hann
- Department of Orthopedic Surgery, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Jennifer L Reeve
- Department of Dermatology, University of Michigan, Ann Arbor, MI, USA
| | - Marilyn G Liang
- Department of Dermatology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Joyce Bischoff
- Department of Surgery, Vascular Biology Program, Boston Children's Hospital, Boston, MA, USA
| | - Matthew L Warman
- Department of Orthopedic Surgery, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
- Howard Hughes Medical Institute, Boston Children's Hospital, Boston, MA, USA
| | - Arin K Greene
- Department of Plastic and Oral Surgery, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
| |
Collapse
|