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Yang KY, Zhao S, Feng H, Shen J, Chen Y, Wang ST, Wang SJ, Zhang YX, Wang Y, Guo C, Liu H, Tang TS. Ca 2+ homeostasis maintained by TMCO1 underlies corpus callosum development via ERK signaling. Cell Death Dis 2022; 13:674. [PMID: 35927240 PMCID: PMC9352667 DOI: 10.1038/s41419-022-05131-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 07/22/2022] [Accepted: 07/25/2022] [Indexed: 01/21/2023]
Abstract
Transmembrane of coiled-coil domains 1 (TMCO1) plays an important role in maintaining homeostasis of calcium (Ca2+) stores in the endoplasmic reticulum (ER). TMCO1-defect syndrome shares multiple features with human cerebro-facio-thoracic (CFT) dysplasia, including abnormal corpus callosum (CC). Here, we report that TMCO1 is required for the normal development of CC through sustaining Ca2+ homeostasis. Tmco1-/- mice exhibit severe agenesis of CC with stalled white matter fiber bundles failing to pass across the midline. Mechanistically, the excessive Ca2+ signals caused by TMCO1 deficiency result in upregulation of FGFs and over-activation of ERK, leading to an excess of glial cell migration and overpopulated midline glia cells in the indusium griseum which secretes Slit2 to repulse extension of the neural fiber bundles before crossing the midline. Supportingly, using the clinical MEK inhibitors to attenuate the over-activated FGF/ERK signaling can significantly improve the CC formation in Tmco1-/- brains. Our findings not only unravel the underlying mechanism of abnormal CC in TMCO1 defect syndrome, but also offer an attractive prevention strategy to relieve the related agenesis of CC in patients.
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Affiliation(s)
- Ke-Yan Yang
- grid.410726.60000 0004 1797 8419State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100101 China
| | - Song Zhao
- grid.410726.60000 0004 1797 8419State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100101 China
| | - Haiping Feng
- grid.410726.60000 0004 1797 8419State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100101 China
| | - Jiaqi Shen
- grid.410726.60000 0004 1797 8419State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100101 China
| | - Yuwei Chen
- grid.410726.60000 0004 1797 8419Beijing Institute of Genomics, University of Chinese Academy of Sciences, Chinese Academy of Sciences/China National Center for Bioinformation, Beijing, 100101 China
| | - Si-Tong Wang
- grid.410726.60000 0004 1797 8419State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100101 China
| | - Si-Jia Wang
- grid.410726.60000 0004 1797 8419State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100101 China
| | - Yu-Xin Zhang
- grid.410726.60000 0004 1797 8419State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100101 China
| | - Yun Wang
- grid.410726.60000 0004 1797 8419State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100101 China
| | - Caixia Guo
- grid.410726.60000 0004 1797 8419Beijing Institute of Genomics, University of Chinese Academy of Sciences, Chinese Academy of Sciences/China National Center for Bioinformation, Beijing, 100101 China
| | - Hongmei Liu
- grid.410726.60000 0004 1797 8419State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100101 China ,grid.9227.e0000000119573309Institute for Stem cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101 China ,grid.512959.3Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, 100101 China
| | - Tie-Shan Tang
- grid.410726.60000 0004 1797 8419State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100101 China ,grid.9227.e0000000119573309Institute for Stem cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101 China ,grid.512959.3Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, 100101 China
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Yang W, Yao YW, Zeng JL, Liang WJ, Wang L, Bai CQ, Liu CH, Song Y. Prognostic value of FGFR1 gene copy number in patients with non-small cell lung cancer: a meta-analysis. J Thorac Dis 2014; 6:803-9. [PMID: 24977006 DOI: 10.3978/j.issn.2072-1439.2014.05.02] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Accepted: 05/06/2014] [Indexed: 01/22/2023]
Abstract
BACKGROUND A number of studies have investigated the relationship between fibroblast growth factor receptor1 (FGFR1) gene copy number and survival in non-small cell lung cancer (NSCLC) patients. However, conclusions reported by different parties seem to be inconsistent, especially regarding the differences among different histopathologic subtypes. To derive a more precise estimate of the prognostic significance of FGFR1 gene copy number, we have reviewed published studies and carried out a meta-analysis. METHODS The meta-analysis was conducted in accordance with PRISMA guidelines. The required data for estimation of individual hazard ratios (HRs) for survival were extracted from the publications and an overall HR was calculated. RESULTS We identified 6 eligible studies, all dealing with NSCLC. The global quality score ranged 32.5-80%, with a median of 53.33%. For FGFR1 amplification in three studies including differed according to histological type, the overall RR was 0.86 which 95% confidence interval (CI) was 0.75 to 0.99 and P value was 0.048. Combined HR for the six evaluable studies was 1.17 (95% CI: 0.95 to 1.43). In the subgroup of squamous cell lung cancer (SQCC), the combined HR was 1.24 (95% CI: 0.89 to 1.73). For the Asian populations' studies, the combined HR was 1.67 (95% CI: 1.1 to 2.52). CONCLUSIONS FGFR1 amplification significantly was more frequent in SQCC. FGFR1 was not associated with poorer survival in patients with NSCLC. Furthermore studies will be needed in terms of survival implications.
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Affiliation(s)
- Wen Yang
- 1 Department of Respiratory Medicine, Jinling Hospital, Nanjing University, School of Medicine, Nanjing 210002, China ; 2 Southern Medical University, Guangzhou 510515, China
| | - Yan-Wen Yao
- 1 Department of Respiratory Medicine, Jinling Hospital, Nanjing University, School of Medicine, Nanjing 210002, China ; 2 Southern Medical University, Guangzhou 510515, China
| | - Jun-Li Zeng
- 1 Department of Respiratory Medicine, Jinling Hospital, Nanjing University, School of Medicine, Nanjing 210002, China ; 2 Southern Medical University, Guangzhou 510515, China
| | - Wen-Jun Liang
- 1 Department of Respiratory Medicine, Jinling Hospital, Nanjing University, School of Medicine, Nanjing 210002, China ; 2 Southern Medical University, Guangzhou 510515, China
| | - Li Wang
- 1 Department of Respiratory Medicine, Jinling Hospital, Nanjing University, School of Medicine, Nanjing 210002, China ; 2 Southern Medical University, Guangzhou 510515, China
| | - Cui-Qing Bai
- 1 Department of Respiratory Medicine, Jinling Hospital, Nanjing University, School of Medicine, Nanjing 210002, China ; 2 Southern Medical University, Guangzhou 510515, China
| | - Chun-Hua Liu
- 1 Department of Respiratory Medicine, Jinling Hospital, Nanjing University, School of Medicine, Nanjing 210002, China ; 2 Southern Medical University, Guangzhou 510515, China
| | - Yong Song
- 1 Department of Respiratory Medicine, Jinling Hospital, Nanjing University, School of Medicine, Nanjing 210002, China ; 2 Southern Medical University, Guangzhou 510515, China
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Manjila S, Chim H, Eisele S, Chowdhry SA, Gosain AK, Cohen AR. History of the Kleeblattschädel deformity: origin of concepts and evolution of management in the past 50 years. Neurosurg Focus 2011; 29:E7. [PMID: 21121721 DOI: 10.3171/2010.9.focus10212] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The history and evolution of surgical strategies for the treatment of Kleeblattschädel deformity are not well described in the medical literature. Kleeblattschädel anomaly is one of the most formidable of the craniosynostoses, requiring a multidisciplinary team for surgical treatment. The initial descriptions of this cloverleaf deformity and the evolution of surgical treatment are detailed in the present report. Two illustrative cases of Kleeblattschädel deformity, syndromic and nonsyndromic craniosynostoses treated by the senior authors, are also described along with insights into operative strategies.
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Affiliation(s)
- Sunil Manjila
- Division of Pediatric Neurosurgery, Rainbow Babies and Children's Hospital, Cleveland, Ohio 44106, USA
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4
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Guzmán-Aránguez A, Irazu M, Yayon A, Pintor J. P2Y receptors activated by diadenosine polyphosphates reestablish Ca(2+) transients in achondroplasic chondrocytes. Bone 2008; 42:516-23. [PMID: 18093889 DOI: 10.1016/j.bone.2007.10.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2007] [Revised: 09/27/2007] [Accepted: 10/24/2007] [Indexed: 10/22/2022]
Abstract
Achondroplasia is the most common type of dwarfism, characterised by a mutation in the gene that encodes the fibroblast growth factor receptor 3 (FGFR3). Achondroplasia mainly affects the chondrocytes and therefore bones do not grow properly since intracellular pathways are altered. In this sense, defective calcium signaling by mutant FGFR3 has been previously described. The purpose of this study was to investigate the presence of purinergic P2Y receptors and how the activation of these receptors can have influence on defective calcium signaling observed in achondroplasic chondrocytes. The presence of P2Y receptors was determined by immunocytochemical and western blot techniques. Calcium mobilization after stimulation with nucleotides, dinucleotides, or, FGF9 application, was measured using the ratiometric dye fura-2/AM and fluorescence imaging. Our results demonstrate the expression of P2Y(1), P2Y(2), P2Y(6) and P2Y(11) receptors in achondroplasic chondrocytes, as well as the activation of these receptors after nucleotides and dinucleotides exposure. The altered calcium signaling of achondroplasic chondrocytes was confirmed, since FGF9 treatment fails to induce calcium mobilization. However, achondroplasic chondrocytes pre-treated with Ap(4)A are able to respond with increases in intracellular calcium after FGF9 stimulation. These findings show the rescue effect of diadenosine tetraphosphate (Ap(4)A), acting by means of P2Y receptors, on defective calcium response triggered by achondroplasic FGFR3.
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Affiliation(s)
- Ana Guzmán-Aránguez
- Departamento de Bioquímica y Biología Molecular IV, E.U. Optica, Universidad Complutense de Madrid, c/Arcos de Jalón s/n 28037 Madrid, Spain
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5
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Britto JA. Advances in the molecular pathogenesis of craniofacial conditions. Oral Maxillofac Surg Clin North Am 2007; 16:567-86. [PMID: 18088755 DOI: 10.1016/j.coms.2004.07.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The impact that the understanding of fibroblast growth factor receptor (FGFR) biology and its relevance to the pathogenesis of the craniosynostoses has made cannot be underestimated. As the genetic and molecular pathology of other conditions become increasingly understood, there is much hope that robust and relevant animal models of these conditions may be generated. From these models-and in conjunction with laboratory studies in vitro-comes a real hope of improved therapeutic strategies. The future lies in increased cooperation between clinicians working in high-volume centers and basic scientists. This article decribes the results of a decade of research in which the molecular pathology of the craniosynostoses was unravelled. The understanding of the importance of FGFR mutations to the genetic etiology of craniosynostosis opened up novel studies in developmental biology in various tissues. Such studies describe the functional effects of FGFR mutations. Investigations of FGFR expression in human craniofacial development have related functional molecular studies to human craniosynostosis syndromes, which provides a link between the gene mutation and the affected child.
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Affiliation(s)
- Jonathan A Britto
- Craniofacial Centre, Great Ormond Street Hospital for Children NHS Trust, Great Ormond Street, London WC1N3JH, UK
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6
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Wilkie AOM. Bad bones, absent smell, selfish testes: The pleiotropic consequences of human FGF receptor mutations. Cytokine Growth Factor Rev 2005; 16:187-203. [PMID: 15863034 DOI: 10.1016/j.cytogfr.2005.03.001] [Citation(s) in RCA: 195] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The discovery in 1994 that highly specific mutations of fibroblast growth factor (FGF) receptor 3 caused the most common form of human short-limbed dwarfism, achondroplasia, heralded a new era in FGF receptor (FGFR) biology. A decade later, the purpose of this review is to survey how the study of humans with FGFR mutations continues to provide insights into FGFR function in health and disease, and the clinical applications of these findings. Amongst the most interesting recent discoveries have been the description of novel phenotypes associated with FGFR1 and FGFR3 mutations; identification of fundamental differences in the cellular mechanisms of mutant FGFR2 and FGFR3 action; and the direct identification of FGFR2 and FGFR3 mutations in sperm. These clinical observations illustrate the pleiotropism of FGFR action and fuel ongoing efforts to understand the rich biology and pathophysiology of the FGF signalling system.
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Affiliation(s)
- Andrew O M Wilkie
- Weatherall Institute of Molecular Medicine, NDCLS, University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK.
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7
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Chen CP, Chern SR, Chang TY, Lin CJ, Wang W, Tzen CY. Second trimester molecular diagnosis of a stop codon FGFR3 mutation in a type I thanatophoric dysplasia fetus following abnormal ultrasound findings. Prenat Diagn 2002; 22:736-7. [PMID: 12210587 DOI: 10.1002/pd.377] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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8
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Okajima K, Asai K, Niwa T, Ohki S, Sobajima H, Tyson J, Malcolm S, Wada Y. Clinical and biochemical findings of a patient with thanatophoric dysplasia type I: additional finding of dicarboxylic aciduria. Cleft Palate Craniofac J 2002; 39:246-8. [PMID: 11879084 DOI: 10.1597/1545-1569_2002_039_0246_cabfoa_2.0.co_2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVE A long-surviving thanatophoric dysplasia type I patient to age of 6 years is presented. RESULTS AND CONCLUSIONS Molecular studies revealed a heterozygous point mutation, S249C in the fibroblast growth factor receptor 3 gene. Most of the clinical course was similar to previous reports, including hearing loss and acanthosis nigricans. Abnormal urinary excretion of dicarboxylic acids and 3-hydroxydicarboxylic acids was observed. We hypothesize that this was a consequence of the FGFR3 mutation.
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Affiliation(s)
- Kazuki Okajima
- Clinical and Molecular Genetics Unit, Institute of Child Health, London, United Kingdom.
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9
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Okajima K, Asai K, Niwa T, Ohki S, Sobajima H, Tyson J, Malcolm S, Wada Y. Clinical and Biochemical Findings of a Patient With Thanatophoric Dysplasia Type I: Additional Finding of Dicarboxylic Aciduria. Cleft Palate Craniofac J 2002. [DOI: 10.1597/1545-1569(2002)039<0246:cabfoa>2.0.co;2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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10
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Camera G, Baldi M, Strisciuglio G, Concolino D, Mastroiacovo P, Baffico M. Occurrence of thanatophoric dysplasia type I (R248C) and hypochondroplasia (N540K) mutations in two patients with achondroplasia phenotype. AMERICAN JOURNAL OF MEDICAL GENETICS 2001; 104:277-81. [PMID: 11754059 DOI: 10.1002/ajmg.10092] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
We report two patients with clinical and radiological findings of achondroplasia, who had the most common FGFR3 mutation occurring in thanatophoric dysplasia type I and hypochondroplasia, respectively. Thanatophoric dysplasia is usually a lethal condition, but the patient carrying this mutation is alive and presents a medical history similar to that of patients with achondroplasia. The events leading to such a discrepancy between genotype and phenotype are unclear. These rare cases may influence an appropriate medical and genetic counseling.
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Affiliation(s)
- G Camera
- Department of Pediatrics and Regional Center of Hand Surgery, San Paolo Hospital, Savona, Italy
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11
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Britto JA, Evans RD, Hayward RD, Jones BM. From genotype to phenotype: the differential expression of FGF, FGFR, and TGFbeta genes characterizes human cranioskeletal development and reflects clinical presentation in FGFR syndromes. Plast Reconstr Surg 2001; 108:2026-39; discussion 2040-6. [PMID: 11743396 DOI: 10.1097/00006534-200112000-00030] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Mutations in the fibroblast growth factor receptor (FGFR) genes 1, 2, and 3 are causal in a number of craniofacial dysostosis syndromes featuring craniosynostosis with basicranial and midfacial deformity. Great clinical variability is displayed in the pathologic phenotypes encountered. To investigate the influence of developmental genetics on clinical diversity in these syndromes, the expression of several genes implicated in their pathology was studied at sequential stages of normal human embryo-fetal cranial base and facial ossification (n = 6). At 8 weeks of gestation, FGFR1, FGFR2, and FGFR3 are equally expressed throughout the predifferentiated mesenchyme of the cranium, the endochondral skull base, and midfacial mesenchyme. Both clinically significant isoforms of FGFR2, IgIIIa/c and IgIIIa/b, are coexpressed in maxillary and basicranial ossification. By 10 to 13 weeks, FGFR1 and FGFR2 are broadly expressed in epithelia, osteogenic, and chondrogenic cell lineages. FGFR3, however, is maximally expressed in dental epithelia and proliferating chondrocytes of the skull base, but poorly expressed in the osteogenic tissues of the midface. FGF2 and FGF4, but not FGF7, and TGFbeta1 and TGFbeta3 are expressed throughout both osteogenic and chondrogenic tissues in early human craniofacial skeletogenesis. Maximal FGFR expression in the skull base proposes a pivotal role for syndromic growth dysplasia at this site. Paucity of FGFR3 expression in human midfacial development correlates with the relatively benign human mutant FGFR3 midfacial phenotypes. The regulation of FGFR expression in human craniofacial skeletogenesis against background excess ligand and selected cofactors may therefore play a profound role in the pathologic craniofacial development of children bearing FGFR mutations.
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Affiliation(s)
- J A Britto
- Craniofacial Centre, Great Ormond Street Hospital for Children, the Developmental Biology Unit, Institute of Child Health, London, England.
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12
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Britto JA, Moore RL, Evans RD, Hayward RD, Jones BM. Negative autoregulation of fibroblast growth factor receptor 2 expression characterizing cranial development in cases of Apert (P253R mutation) and Pfeiffer (C278F mutation) syndromes and suggesting a basis for differences in their cranial phenotypes. J Neurosurg 2001; 95:660-73. [PMID: 11596961 DOI: 10.3171/jns.2001.95.4.0660] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECT Heterogeneous mutations in the fibroblast growth factor receptor 2 gene (FGFR2) cause a range of craniosynostosis syndromes. The specificity of the Apert syndrome-affected cranial phenotype reflects its narrow mutational range: 98% of cases of Apert syndrome result from an Ser252Trp or Pro253Arg mutation in the immunoglobulin-like (Ig)IIIa extracellular subdomain of FGFR2. In contrast, a broad range of mutations throughout the extracellular domain of FGFR2 causes the overlapping cranial phenotypes of Pfeiffer and Crouzon syndromes and related craniofacial dysostoses. METHODS In this paper the expression of FGFR1, the IgIIIa/c and IgIIIa/b isoforms of FGFR2, and FGFR3 is investigated in Apert syndrome (P253R mutation)- and Pfeiffer syndrome (C278F mutation)-affected fetal cranial tissue and is contrasted with healthy human control tissues. Both FGFR1 and FGFR3 are normally expressed in the differentiated osteoblasts of the periosteum and osteoid, in domains overlapped by that of FGFR2, which widely include preosseous cranial mesenchyme. Expression of FGFR2, however, is restricted to domains of advanced osseous differentiation in both Apert syndrome- and Pfeiffer syndrome-affected cranial skeletogenesis in the presence of fibroblast growth factor (FGF)2, but not in the presence of FGF4 or FGF7. Whereas expression of the FGFR2-IgIIIa/b (KGFR) isoform is restricted in normal human cranial osteogenesis, there is preliminary evidence that KGFR is ectopically expressed in Pfeiffer syndrome-affected cranial osteogenesis. CONCLUSIONS Contraction of the FGFR2-IgIIIa/c (BEK) expression domain in cases of Apert syndrome- and Pfeiffer syndrome-affected fetal cranial ossification suggests that the mutant activation of this receptor, by ligand-dependent or ligand-independent means, results in negative autoregulation. This phenomenon, resulting from different mechanisms in the two syndromes, offers a model by which to explain differences in their cranial phenotypes.
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Affiliation(s)
- J A Britto
- The Craniofacial Centre, Great Ormond Street Hospital for Children, London, United Kingdom.
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13
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Britto JA, Chan JC, Evans RD, Hayward RD, Jones BM. Differential expression of fibroblast growth factor receptors in human digital development suggests common pathogenesis in complex acrosyndactyly and craniosynostosis. Plast Reconstr Surg 2001; 107:1331-8; discussion 1339-45. [PMID: 11335797 DOI: 10.1097/00006534-200105000-00001] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The Apert hand is characterized by metaphyseal fusions of the metacarpals and distal phalanges, symphalangism, and soft-tissue syndactyly. More subtle skeletal anomalies of the limb characterize Pfeiffer and Crouzon syndromes. Different mutations in the fibroblast growth factor receptor 2 (FGFR2) gene cause these syndromes, and offer the opportunity to relate genotype to phenotype. The expression of FGFR1 and of the Bek and KGFR isoforms of FGFR2 has, therefore, been studied in human hand development at 12 weeks by in situ hybridization. FGFRs are differentially expressed in the mesenchyme and skeletal elements during endochondral ossification of the developing human hand. KGFR expression characterizes the metaphyseal periosteum and interphalangeal joints. FGFR1 is preferentially expressed in the diaphyses, whereas FGFR2-Bek expression characterizes metaphyseal and diaphyseal elements, and the interdigital mesenchyme. Apert metaphyseal synostosis and symphalangism reflect KGFR expression, which has independently been quantitatively related ex vivo to the severity of clinical digital presentations in these syndromes. Studies in avian development implicate FGF signaling in preventing interdigital apoptosis and maintaining the interdigital mesenchyme. Herein is proposed that in human FGFR syndromes the balance of signaling by means of KGFR and Bek in digital development determines the clinical severity of soft-tissue and bony syndactyly.
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Affiliation(s)
- J A Britto
- Craniofacial Centre, Great Ormond Street Hospital for Children, London, England.
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Jiang L, Jha V, Dhanabal M, Sukhatme VP, Alper SL. Intracellular Ca(2+) signaling in endothelial cells by the angiogenesis inhibitors endostatin and angiostatin. Am J Physiol Cell Physiol 2001; 280:C1140-50. [PMID: 11287327 DOI: 10.1152/ajpcell.2001.280.5.c1140] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Intracellular signaling mechanisms by the angiogenesis inhibitors endostatin and angiostatin remain poorly understood. We have found that endostatin (2 microg/ml) and angiostatin (5 microg/ml) elicited transient, approximately threefold increases in intracellular Ca(2+) concentration ([Ca(2+)](i)). Acute exposure to angiostatin or endostatin nearly abolished subsequent endothelial [Ca(2+)](i) responses to carbachol or to thapsigargin; conversely, thapsigargin attenuated the Ca(2+) signal elicited by endostatin. The phospholipase C inhibitor U-73122 and the inositol trisphosphate (IP(3)) receptor inhibitor xestospongin C both inhibited endostatin-induced elevation in [Ca(2+)](i), and endostatin rapidly elevated endothelial cell IP(3) levels. Pertussis toxin and SB-220025 modestly inhibited the endostatin-induced Ca(2+) signal. Removal of extracellular Ca(2+) inhibited the endostatin-induced rise in [Ca(2+)](i), as did a subset of Ca(2+)-entry inhibitors. Peak Ca(2+) responses to endostatin and angiostatin in endothelial cells exceeded those in epithelial cells and were minimal in NIH/3T3 cells. Overnight pretreatment of endothelial cells with endostatin reduced the subsequent acute elevation in [Ca(2+)](i) in response to vascular endothelial growth factor or to fibroblast growth factor by approximately 70%. Intracellular Ca(2+) signaling may initiate or mediate some of the cellular actions of endostatin and angiostatin.
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Affiliation(s)
- L Jiang
- Molecular Medicine and Renal Units and The Cancer Center, Beth Israel Deaconess Medical Center and Departments of Medicine and Cell Biology, Harvard Medical School, Boston, Massachusetts 02215, USA
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15
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Raffioni S, Zhu YZ, Bradshaw RA, Thompson LM. Effect of transmembrane and kinase domain mutations on fibroblast growth factor receptor 3 chimera signaling in PC12 cells. A model for the control of receptor tyrosine kinase activation. J Biol Chem 1998; 273:35250-9. [PMID: 9857065 DOI: 10.1074/jbc.273.52.35250] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The effect of six point mutations causing various human skeletal dysplasias, occurring in the transmembrane (TM) and kinase domains (KD) of fibroblast growth factor receptor 3, were introduced into a chimera composed of the extracellular domain of human platelet-derived growth factor beta and the TM and intracellular domains of hFGFR3. Stable transfectants in rat PC12 cells showed distinct differences in the two classes of mutations. The cells containing TM mutants displayed normal expression and activation but higher responsiveness to lower doses of ligand. The KD mutants showed significantly altered expression patterns. Normal amounts of a lower Mr receptor (p130) reflecting incomplete glycosylation, but only greatly decreased amounts of the mature (p170) form, were observed. However, the latter material showed normal ligand-dependent activation. In contrast, the p130 form, which is regularly observed in the expression of both native and chimeric receptors, exhibits strong ligand-independent tyrosine phosphorylation, particularly with the K650E mutation. Expression of two of the KD mutants (K650M and K650E), under control of an inducible metallothionein promoter, indicated that this receptor was sufficiently autoactivated to produce at least partial differentiation and, in the case of the K650E mutation, to induce ligand-independent neurite outgrowth. A model is presented that suggests that the low Mr (p130) KD mutants can, under the right conditions, signal intracellularly, but when they are fully glycosylated and move to the cell surface they adopt a normal, inhibited conformation, in the form of ligand-independent dimers, that neutralizes the effects of the mutations. When ligands bind, these dimeric receptors are activated in a normal manner. This model suggests that unliganded dimers may be a common intermediate in receptor tyrosine kinase signaling.
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Affiliation(s)
- S Raffioni
- Department of Physiology and Biophysics, College of Medicine, University of California, Irvine, California 92697, USA
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