46 results on '"Gregory LC"'
Search Results
2. Mutations in the Gene Encoding Fibroblast Growth Factor 8,FGF8,Are Associated with Complex Midline and Hypothalamo-Pituitary Defects.
- Author
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McCabe, MJ, primary, Tziaferi, V, additional, Gaston-Massuet, C, additional, Gregory, LC, additional, Walker, J, additional, Tsai, PS, additional, Pitteloud, N, additional, Martinez-Barbera, JP, additional, and Dattani, MT, additional
- Published
- 2010
- Full Text
- View/download PDF
3. Carbonate and silicate intercomparison materials for cosmogenic ³⁶Cl measurements
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Mechernich, S, Dunai, TJ, Binnie, SA, Goral, T, Heinze, S, Dewald, A, Schimmelpfennig, I, Keddadouche, K, Aumaître, G, Bourlès, D, Marrero, S, Wilcken, K, Simon, K, Fink, D, Phillips, FM, Caffee, MW, Gregory, LC, Phillips, R, Freeman, SPHT, Shanks, R, Akif Sarıkaya, M, Pavetich, S, Rugel, G, Merchel, S, Akçar, N, Yesilyurt, S, Ivy-Ochs, S, and Vockenhuber, C
- Abstract
Two natural mineral separates, labeled CoCal-N and CoFsp-N, have been prepared to serve as intercomparison material (ICM) for in situ-produced cosmogenic ³⁶Cl and natural chlorine (Clnat) analysis. The sample CoCal-N is derived from calcite crystals in a Namibian lag deposit, while the sample CoFsp-N is derived from a single crystal of alkali-feldspar from a Namibian pegmatite. The sample preparation took place at the University of Cologne and a rotating splitter was used to obtain homogeneous splits of both ICMs. Forty-five measurements of CoCal-N (between 1 and 16 per facility) and forty-four measurements of CoFsp-N (between 2 and 20 per facility) have been undertaken by ten target preparation laboratories measured by seven different AMS facilities. The internal laboratory scatter of the ³⁶Cl concentrations indicates no overdispersion for half of the laboratories and 3.9 to 7.3% (1σ) overdispersion for the others. We show that the CoCal-N and CoFsp-N splits are homogeneous regarding their ³⁶Cl and Clnat concentrations. The grand average (average calculated from the average of each laboratory) yields initial consensus ³⁶Cl concentrations of (3.74 ± 0.10) × 10⁶ at ³⁶Cl/g (CoCal-N) and (2.93 ± 0.07) × 10⁶ at ³⁶Cl/g (CoFsp-N) at 95% confidence intervals. The coefficient of variation is 5.1% and 4.2% for CoCal-N and CoFsp-N, respectively. The Clnat concentration corresponds to the lower and intermediate range of typical rock samples with (0.73 ± 0.18) µg/g in CoCal-N and (73.9 ± 6.8) µg/g in CoFsp-N. We discuss the most relevant points of the sample preparation and measurement and the chlorine concentration calculation to further approach inter-laboratory comparability. We propose to use continuous measurements of the ICMs to provide a valuable quality control for future determination of ³⁶Cl and Clnat concentrations.
- Published
- 2019
4. Orogen-scale uplift drives episodic behaviour of earthquake faults
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Cowie, Pa, Phillips, Rj, Roberts, Gp, Mccaffrey, K, Zijerveld, Ljj, Gregory, Lc, Faure Walker, J, Wedmore, L, Dunai, Tj, Binnie, Sa, Freeman, Spht, Wilcken, K, Shanks, Rp, Huismans, Rs, Papanikolaou, I, Michetti, ALESSANDRO MARIA, and Wilkinson, M.
- Published
- 2017
5. Surface faulting during the August 24, 2016, Central Italy earthquake (Mw 6.0): preliminary results
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Livio, F, Michetti, AM, Vittori, E, Gregory, LC, Wedmore, L, Piccardi, I, Tondi, E, and Roberts, G
- Abstract
We present some preliminary results on the mapping of coseismically-induced ground ruptures following the Aug. 24, 2016, Central Italy earthquake (Mw 6.0). The seismogenic source, as highlighted by InSAR and seismological data, ruptured across two adjacent structures: the Mt. Vettore and Laga faults. We col-lected field data on ground breaks along the whole deformed area and two different scenarios of on-fault coseismic displacement arise from these observations. To the north, along the Mt. Vettore fault, surface faulting can be mapped quite continuously along a well-defined fault strand while such features are almost absent to the south, along the Laga fault, where flysch-like marly units are present. A major lithological control affects the surface expression of faulting, resulting in a complex deformation pattern.
- Published
- 2016
6. Novel application of luciferase assay for the in vitro functional assessment of KAL1 variants in three females with septo-optic dysplasia (SOD).
- Author
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McCabe, MJ, Hu, Y, Gregory, LC, Gaston-Massuet, C, Alatzoglou, KS, Saldanha, JW, Gualtieri, A, Thankamony, A, Hughes, I, Townshend, S, Martinez-Barbera, JP, Bouloux, PM, Dattani, MT, McCabe, MJ, Hu, Y, Gregory, LC, Gaston-Massuet, C, Alatzoglou, KS, Saldanha, JW, Gualtieri, A, Thankamony, A, Hughes, I, Townshend, S, Martinez-Barbera, JP, Bouloux, PM, and Dattani, MT
- Abstract
KAL1 is implicated in 5% of Kallmann syndrome cases, a disorder which genotypically overlaps with septo-optic dysplasia (SOD). To date, a reporter-based assay to assess the functional consequences of KAL1 mutations is lacking. We aimed to develop a luciferase assay for novel application to functional assessment of rare KAL1 mutations detected in a screen of 422 patients with SOD.Quantitative analysis was performed using L6-myoblasts stably expressing FGFR1, transfected with a luciferase-reporter vector containing elements of the FGF-responsive osteocalcin promoter.The two variants assayed [p.K185N, p.P291T], were detected in three females with SOD (presenting with optic nerve hypoplasia, midline and pituitary defects). Our novel assay revealed significant decreasesin transcriptional activity [p.K185N: 21% (p < 0.01); p.P291T: 40% (p < 0.001)].Our luciferase-reporter assay, developed for assessment of KAL1 mutations, determined that two variants in females with hypopituitarism/SOD are loss-of-function; demonstrating that this assay is suitable for quantitative assessment of mutations in this gene.
- Published
- 2015
7. The role of the sonic hedgehog signalling pathway in patients with midline defects and congenital hypopituitarism.
- Author
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Gregory, LC, Gaston-Massuet, C, Andoniadou, CL, Carreno, G, Webb, EA, Kelberman, D, McCabe, MJ, Panagiotakopoulos, L, Saldanha, JW, Spoudeas, HA, Torpiano, J, Rossi, M, Raine, J, Canham, N, Martinez-Barbera, JP, Dattani, MT, Gregory, LC, Gaston-Massuet, C, Andoniadou, CL, Carreno, G, Webb, EA, Kelberman, D, McCabe, MJ, Panagiotakopoulos, L, Saldanha, JW, Spoudeas, HA, Torpiano, J, Rossi, M, Raine, J, Canham, N, Martinez-Barbera, JP, and Dattani, MT
- Published
- 2015
8. Structural pituitary abnormalities associated with CHARGE syndrome
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Gregory, LC, Gevers, EF, Baker, J, Kasia, T, Chong, K, Josifova, DJ, Caimari, M, Bilan, F, McCabe, MJ, Dattani, MT, Gregory, LC, Gevers, EF, Baker, J, Kasia, T, Chong, K, Josifova, DJ, Caimari, M, Bilan, F, McCabe, MJ, and Dattani, MT
- Abstract
Introduction: CHARGE syndrome is a multi system disorder that, in addition to Kallmann syndrome/isolated hypogonadotrophic hypogonadism, has been associated with anterior pituitary hypopla-sia (APH). However, structural abnormalities such as an ectopic posterior pituitary (EPP) have not yet been described in such patients. Objective: The aims of the study were: 1) to describe the association between CHARGE syndrome and a structurally abnormal pituitary gland; and 2) to investigate whether CHD7 variants, which are identified in 65% of CHARGE patients, are common in septo-optic dysplasia/hypopituitarism. Methods: We describe 2 patients with features of CHARGE and EPP. CHD7 was sequenced in these and other patients with septo-optic dysplasia/hypopituitarism. Results: EPP, APH, and GH, TSH, and probable LH/FSH deficiency were present in 1 patient, and EPP and APH with GH, TSH, LH/FSH, and ACTH deficiency were present in another patient, both of whom had features of CHARGE syndrome. Both had variations in CHD7 that were novel and undetected in control cohorts or in the international database of CHARGE patients, but were also present in their unaffected mothers. No CHD7 variants were detected in the patients with septo-optic dysplasia/hypopituitarism without additional CHARGE features. Conclusion: We report a novel association between CHARGE syndrome and structural abnormalities of the pituitary gland in 2 patients with variations in CHD7 that are of unknown significance. However, CHD7 mutations are an uncommon cause of septo-optic dysplasia or hypopituitarism. Our data suggest the need for evaluation of pituitary function/anatomy in patients with CHARGE syndrome. Copyright © 2013 by The Endocrine Society.
- Published
- 2013
9. Variations in, But Not, Are Associated With Hypopituitarism and Septo-optic Dysplasia
- Author
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McCabe, MJ, Gaston-Massuet, C, Gregory, LC, Alatzoglou, KS, Tziaferi, V, Sbai, O, Rondard, P, Masumoto, K-H, Nagano, M, Shigeyoshi, Y, Pfeifer, M, Hulse, T, Buchanan, CR, Pitteloud, N, Martinez-Barbera, J-P, Dattani, MT, McCabe, MJ, Gaston-Massuet, C, Gregory, LC, Alatzoglou, KS, Tziaferi, V, Sbai, O, Rondard, P, Masumoto, K-H, Nagano, M, Shigeyoshi, Y, Pfeifer, M, Hulse, T, Buchanan, CR, Pitteloud, N, Martinez-Barbera, J-P, and Dattani, MT
- Published
- 2013
10. Pituitary Gland Development: An Update
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Mullis, PE, Bancalari, RE, Gregory, LC, McCabe, MJ, Dattani, MT, Mullis, PE, Bancalari, RE, Gregory, LC, McCabe, MJ, and Dattani, MT
- Abstract
The embryonic development of the pituitary gland involves a complex and highly spatio- temporally regulated network of integrating signalling molecules and transcription factors. Genetic mutations in any of these factors can lead to congenital hypopituitarism in association with a wide spectrum of craniofacial/midline defects ranging from incompatibility with life to holoprosencephaly (HPE) and cleft palate and septo- optic dysplasia (SOD). Increasing evidence supports a genotypic overlap with hypogonadotrophic hypogonadal disorders such as Kallmann syndrome, which is consistent with the known overlap in phenotypes between these disorders. This chapter reviews the cascade of events leading up to the successful development of the pituitary gland and to highlight key areas where genetic variations can occur thus leading to congenital hypopituitarism and associated defects.
- Published
- 2012
11. Genetic overlap in Kallmann syndrome, combined pituitary hormone deficiency, and septo-optic dysplasia
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Raivio, T, Avbelj, M, McCabe, MJ, Romero, CJ, Dwyer, AA, Tommiska, J, Sykiotis, GP, Gregory, LC, Diaczok, D, Tziaferi, V, Elting, MW, Padidela, R, Plummer, L, Martin, C, Feng, B, Zhang, C, Zhou, QY, Chen, H, Mohammadi, M, Quinton, R, Sidis, Y, Radovick, S, Dattani, MT, Pitteloud, N, Raivio, T, Avbelj, M, McCabe, MJ, Romero, CJ, Dwyer, AA, Tommiska, J, Sykiotis, GP, Gregory, LC, Diaczok, D, Tziaferi, V, Elting, MW, Padidela, R, Plummer, L, Martin, C, Feng, B, Zhang, C, Zhou, QY, Chen, H, Mohammadi, M, Quinton, R, Sidis, Y, Radovick, S, Dattani, MT, and Pitteloud, N
- Abstract
Context: Kallmann syndrome (KS), combined pituitary hormone deficiency (CPHD), and septo-optic dysplasia (SOD) all result from development defects of the anterior midline in the human forebrain. Objective: The objective of the study was to investigate whether KS, CPHD, and SOD have shared genetic origins. Design and Participants: A total of 103 patients with either CPHD (n = 35) or SOD (n = 68) were investigated for mutations in gene simplicated in the etiology of KS (FGFR1, FGF8, PROKR2, PROK2, and KAL1). Consequences of identified FGFR1, FGF8, and PROKR2 mutations were investigated in vitro. Results: Three patients with SOD had heterozygous mutations in FGFR1; these were either shown to alter receptor signaling (p.S450F, p.P483S) or predicted to affect splicing (c.336C>T, p.T112T). One patient had a synonymous change in FGF8 (c.216G>A, p.T72T) that was shown to affect splicing and ligand signaling activity. Four patients with CPHD/SOD were found to harbor heterozygous rare loss-of-function variants in PROKR2 (p.R85G, p.R85H, p.R268C). Conclusions: Mutations in FGFR1/FGF8/PROKR2 contributed to 7.8% of our patients with CPHD/ SOD. These data suggest a significant genetic overlap between conditions affecting the development of anterior midline in the human forebrain. Copyright © 2012 by The Endocrine Society.
- Published
- 2012
12. NovelMutations Associated with Recessive Holoprosencephaly, Craniofacial Defects, and Hypothalamo-Pituitary Dysfunction
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McCabe, MJ, Gaston-Massuet, C, Tziaferi, V, Gregory, LC, Alatzoglou, KS, Signore, M, Puelles, E, Gerrelli, D, Farooqi, IS, Raza, J, Walker, J, Kavanaugh, SI, Tsai, P-S, Pitteloud, N, Martinez-Barbera, J-P, Dattani, MT, McCabe, MJ, Gaston-Massuet, C, Tziaferi, V, Gregory, LC, Alatzoglou, KS, Signore, M, Puelles, E, Gerrelli, D, Farooqi, IS, Raza, J, Walker, J, Kavanaugh, SI, Tsai, P-S, Pitteloud, N, Martinez-Barbera, J-P, and Dattani, MT
- Published
- 2011
13. Identification of genetic variants and phenotypic characterization of a large cohort of patients with congenital hypopituitarism and related disorders.
- Author
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Gregory LC, Cionna C, Cerbone M, and Dattani MT
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- Humans, Mutation, Transcription Factors genetics, Phenotype, Genes, Homeobox, Hypopituitarism genetics
- Abstract
Purpose: Congenital hypopituitarism (CH) disorders are phenotypically variable. Variants in multiple genes are associated with these disorders, with variable penetrance and inheritance., Methods: We screened a large cohort (N = 1765) of patients with or at risk of CH using Sanger sequencing, selected according to phenotype, and conducted next-generation sequencing (NGS) in 51 families within our cohort. We report the clinical, hormonal, and neuroradiological phenotypes of patients with variants in known genes associated with CH., Results: We identified variants in 178 patients: GH1/GHRHR (51 patients of 414 screened), PROP1 (17 of 253), POU1F1 (15 of 139), SOX2 (13 of 59), GLI2 (7 of 106), LHX3/LHX4 (8 of 110), HESX1 (8 of 724), SOX3 (9 of 354), OTX2 (5 of 59), SHH (2 of 64), and TCF7L1, KAL1, FGFR1, and FGF8 (2 of 585, respectively). NGS identified 26 novel variants in 35 patients (from 24 families). Magnetic resonance imaging showed prevalent hypothalamo-pituitary abnormalities, present in all patients with PROP1, GLI2, SOX3, HESX1, OTX2, LHX3, and LHX4 variants. Normal hypothalamo-pituitary anatomy was reported in 24 of 121, predominantly those with GH1, GHRHR, POU1F1, and SOX2 variants., Conclusion: We identified variants in 10% (178 of 1765) of our CH cohort. NGS has revolutionized variant identification, and careful phenotypic patient characterization has improved our understanding of CH. We have constructed a flow chart to guide genetic analysis in these patients, which will evolve upon novel gene discoveries., Competing Interests: Conflict of Interest The authors declare no conflicts of interest., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2023
- Full Text
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14. Beyond basic research: the contribution of cathepsin B to cancer development, diagnosis and therapy.
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Zamyatnin AA Jr, Gregory LC, Townsend PA, and Soond SM
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- Humans, Peptide Hydrolases, Cathepsin B metabolism, Neoplasms diagnosis, Neoplasms therapy
- Abstract
Introduction: In view of other candidate proteins from the cathepsin family of proteases holding great potential in being targeted during cancer therapy, the importance of Cathepsin B (CtsB) stands out as being truly exceptional. Based on its contribution to oncogenesis, its intimate connection with regulating apoptosis and modulating extracellular and intracellular functions through its secretion or compartmentalized subcellular localization, collectively highlight its complex molecular involvement with a myriad of normal and pathological regulatory processes. Despite its complex functional nature, CtsB is emerging as one of the few cathepsin proteases that has been extensively researched to yield tangible outcomes for cancer therapy., Areas Covered: In this article, we review the scientific literature that has justified or shaped the importance of CtsB expression in cancer progression, from the perspective of highlighting a paradigm that is rapidly changing from basic research toward a broader clinical and translational context., Expert Opinion: In doing so, we detail its maturation as a diagnostic marker through describing the development of CtsB-specific Activity-Based Probes, the rapid evolution of these toward a new generation of Prodrugs, and the evaluation of these in model systems for their therapeutic potential as anti-cancer agents in the clinic.
- Published
- 2022
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15. Pathogenic variants in RNPC3 are associated with hypopituitarism and primary ovarian insufficiency.
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Akin L, Rizzoti K, Gregory LC, Corredor B, Le Quesne Stabej P, Williams H, Buonocore F, Mouilleron S, Capra V, McGlacken-Byrne SM, Martos-Moreno GÁ, Azmanov DN, Kendirci M, Kurtoglu S, Suntharalingham JP, Galichet C, Gustincich S, Tasic V, Achermann JC, Accogli A, Filipovska A, Tuilpakov A, Maghnie M, Gucev Z, Gonen ZB, Pérez-Jurado LA, Robinson I, Lovell-Badge R, Argente J, and Dattani MT
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- Animals, Female, Humans, Male, Mice, Nuclear Proteins genetics, Pedigree, Phenotype, Prolactin genetics, RNA-Binding Proteins genetics, Hypopituitarism genetics, Primary Ovarian Insufficiency genetics
- Abstract
Purpose: We aimed to investigate the molecular basis underlying a novel phenotype including hypopituitarism associated with primary ovarian insufficiency., Methods: We used next-generation sequencing to identify variants in all pedigrees. Expression of Rnpc3/RNPC3 was analyzed by in situ hybridization on murine/human embryonic sections. CRISPR/Cas9 was used to generate mice carrying the p.Leu483Phe pathogenic variant in the conserved murine Rnpc3 RRM2 domain., Results: We described 15 patients from 9 pedigrees with biallelic pathogenic variants in RNPC3, encoding a specific protein component of the minor spliceosome, which is associated with a hypopituitary phenotype, including severe growth hormone (GH) deficiency, hypoprolactinemia, variable thyrotropin (also known as thyroid-stimulating hormone) deficiency, and anterior pituitary hypoplasia. Primary ovarian insufficiency was diagnosed in 8 of 9 affected females, whereas males had normal gonadal function. In addition, 2 affected males displayed normal growth when off GH treatment despite severe biochemical GH deficiency. In both mouse and human embryos, Rnpc3/RNPC3 was expressed in the developing forebrain, including the hypothalamus and Rathke's pouch. Female Rnpc3 mutant mice displayed a reduction in pituitary GH content but with no reproductive impairment in young mice. Male mice exhibited no obvious phenotype., Conclusion: Our findings suggest novel insights into the role of RNPC3 in female-specific gonadal function and emphasize a critical role for the minor spliceosome in pituitary and ovarian development and function., Competing Interests: Conflict of Interest All authors declare that they have no conflicts of interest., (Copyright © 2021 American College of Medical Genetics and Genomics. All rights reserved.)
- Published
- 2022
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16. A recessive PRDM13 mutation results in congenital hypogonadotropic hypogonadism and cerebellar hypoplasia.
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Whittaker DE, Oleari R, Gregory LC, Le Quesne-Stabej P, Williams HJ, Torpiano JG, Formosa N, Cachia MJ, Field D, Lettieri A, Ocaka LA, Paganoni AJ, Rajabali SH, Riegman KL, De Martini LB, Chaya T, Robinson IC, Furukawa T, Cariboni A, Basson MA, and Dattani MT
- Subjects
- Animals, Cerebellum enzymology, Developmental Disabilities enzymology, Developmental Disabilities genetics, Disease Models, Animal, Humans, Mice, Mice, Mutant Strains, Neurons enzymology, Cerebellum abnormalities, Histone-Lysine N-Methyltransferase genetics, Histone-Lysine N-Methyltransferase metabolism, Hypogonadism enzymology, Hypogonadism genetics, Hypothalamus enzymology, Mutation, Nervous System Malformations enzymology, Nervous System Malformations genetics, Transcription Factors genetics, Transcription Factors metabolism
- Abstract
The positive regulatory (PR) domain containing 13 (PRDM13) putative chromatin modifier and transcriptional regulator functions downstream of the transcription factor PTF1A, which controls GABAergic fate in the spinal cord and neurogenesis in the hypothalamus. Here, we report a recessive syndrome associated with PRDM13 mutation. Patients exhibited intellectual disability, ataxia with cerebellar hypoplasia, scoliosis, and delayed puberty with congenital hypogonadotropic hypogonadism (CHH). Expression studies revealed Prdm13/PRDM13 transcripts in the developing hypothalamus and cerebellum in mouse and human. An analysis of hypothalamus and cerebellum development in mice homozygous for a Prdm13 mutant allele revealed a significant reduction in the number of Kisspeptin (Kiss1) neurons in the hypothalamus and PAX2+ progenitors emerging from the cerebellar ventricular zone. The latter was accompanied by ectopic expression of the glutamatergic lineage marker TLX3. Prdm13-deficient mice displayed cerebellar hypoplasia and normal gonadal structure, but delayed pubertal onset. Together, these findings identify PRDM13 as a critical regulator of GABAergic cell fate in the cerebellum and of hypothalamic kisspeptin neuron development, providing a mechanistic explanation for the cooccurrence of CHH and cerebellar hypoplasia in this syndrome. To our knowledge, this is the first evidence linking disrupted PRDM13-mediated regulation of Kiss1 neurons to CHH in humans.
- Published
- 2021
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17. The phenotypic spectrum associated with OTX2 mutations in humans.
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Gregory LC, Gergics P, Nakaguma M, Bando H, Patti G, McCabe MJ, Fang Q, Ma Q, Ozel AB, Li JZ, Poina MM, Jorge AAL, Benedetti AFF, Lerario AM, Arnhold IJP, Mendonca BB, Maghnie M, Camper SA, Carvalho LRS, and Dattani MT
- Subjects
- Adolescent, Animals, Animals, Genetically Modified, Brazil, Cell Line, Child, Child, Preschool, Cohort Studies, Female, Humans, Hypopituitarism embryology, Hypopituitarism genetics, Hypothalamus cytology, Infant, Male, Mice, Microphthalmos embryology, Microphthalmos genetics, Mutation, Neurons pathology, Pedigree, Pituitary Gland embryology, Pituitary Gland pathology, Septo-Optic Dysplasia embryology, Septo-Optic Dysplasia genetics, United Kingdom, Hypopituitarism physiopathology, Microphthalmos physiopathology, Neurons physiology, Otx Transcription Factors genetics, Pituitary Gland physiopathology, Septo-Optic Dysplasia physiopathology
- Abstract
Objective: The transcription factor OTX2 is implicated in ocular, craniofacial, and pituitary development., Design: We aimed to establish the contribution of OTX2 mutations in congenital hypopituitarism patients with/without eye abnormalities, study functional consequences, and establish OTX2 expression in the human brain, with a view to investigate the mechanism of action., Methods: We screened patients from the UK (n = 103), international centres (n = 24), and Brazil (n = 282); 145 were within the septo-optic dysplasia spectrum, and 264 had no eye phenotype. Transactivation ability of OTX2 variants was analysed in murine hypothalamic GT1-7 neurons. In situ hybridization was performed on human embryonic brain sections. Genetically engineered mice were generated with a series of C-terminal OTX2 variants., Results: Two chromosomal deletions and six haploinsufficient mutations were identified in individuals with eye abnormalities; an affected relative of one patient harboured the same mutation without an ocular phenotype. OTX2 truncations led to significant transactivation reduction. A missense variant was identified in another patient without eye abnormalities; however, studies revealed it was most likely not causative. In the mouse, truncations proximal to aa219 caused anophthalmia, while distal truncations and the missense variant were tolerated. During human embryogenesis, OTX2 was expressed in the posterior pituitary, retina, ear, thalamus, choroid plexus, and partially in the hypothalamus, but not in the anterior pituitary., Conclusions: OTX2 mutations are rarely associated with hypopituitarism in isolation without eye abnormalities, and may be variably penetrant, even within the same pedigree. Our data suggest that the endocrine phenotypes in patients with OTX2 mutations are of hypothalamic origin.
- Published
- 2021
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18. Activating mutations in BRAF disrupt the hypothalamo-pituitary axis leading to hypopituitarism in mice and humans.
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Gualtieri A, Kyprianou N, Gregory LC, Vignola ML, Nicholson JG, Tan R, Inoue SI, Scagliotti V, Casado P, Blackburn J, Abollo-Jimenez F, Marinelli E, Besser REJ, Högler W, Karen Temple I, Davies JH, Gagunashvili A, Robinson ICAF, Camper SA, Davis SW, Cutillas PR, Gevers EF, Aoki Y, Dattani MT, and Gaston-Massuet C
- Subjects
- Animals, Cell Cycle Proteins genetics, Cell Cycle Proteins metabolism, Cells, Cultured, Child, Child, Preschool, Corticotrophs cytology, Corticotrophs metabolism, Ectodermal Dysplasia genetics, Facies, Failure to Thrive genetics, HEK293 Cells, Heart Defects, Congenital genetics, Humans, Infant, MAP Kinase Signaling System genetics, Melanotrophs cytology, Melanotrophs metabolism, Mice, Knockout, Mice, Transgenic, Proto-Oncogene Proteins B-raf metabolism, Exome Sequencing methods, Mice, Gain of Function Mutation, Hypopituitarism genetics, Hypothalamus metabolism, Pituitary Gland metabolism, Proto-Oncogene Proteins B-raf genetics
- Abstract
Germline mutations in BRAF and other components of the MAPK pathway are associated with the congenital syndromes collectively known as RASopathies. Here, we report the association of Septo-Optic Dysplasia (SOD) including hypopituitarism and Cardio-Facio-Cutaneous (CFC) syndrome in patients harbouring mutations in BRAF. Phosphoproteomic analyses demonstrate that these genetic variants are gain-of-function mutations leading to activation of the MAPK pathway. Activation of the MAPK pathway by conditional expression of the Braf
V600E/+ allele, or the knock-in BrafQ241R/+ allele (corresponding to the most frequent human CFC-causing mutation, BRAF p.Q257R), leads to abnormal cell lineage determination and terminal differentiation of hormone-producing cells, causing hypopituitarism. Expression of the BrafV600E/+ allele in embryonic pituitary progenitors leads to an increased expression of cell cycle inhibitors, cell growth arrest and apoptosis, but not tumour formation. Our findings show a critical role of BRAF in hypothalamo-pituitary-axis development both in mouse and human and implicate mutations found in RASopathies as a cause of endocrine deficiencies in humans.- Published
- 2021
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19. The Molecular Basis of Congenital Hypopituitarism and Related Disorders.
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Gregory LC and Dattani MT
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- Humans, Hypopituitarism genetics, Hypopituitarism metabolism, Prognosis, Transcription Factors metabolism, Gene Expression Regulation, Hypopituitarism congenital, Hypopituitarism pathology, Mutation, Transcription Factors genetics
- Abstract
Context: Congenital hypopituitarism (CH) is characterized by the presence of deficiencies in one or more of the 6 anterior pituitary (AP) hormones secreted from the 5 different specialized cell types of the AP. During human embryogenesis, hypothalamo-pituitary (HP) development is controlled by a complex spatio-temporal genetic cascade of transcription factors and signaling molecules within the hypothalamus and Rathke's pouch, the primordium of the AP., Evidence Acquisition: This mini-review discusses the genes and pathways involved in HP development and how mutations of these give rise to CH. This may present in the neonatal period or later on in childhood and may be associated with craniofacial midline structural abnormalities such as cleft lip/palate, visual impairment due to eye abnormalities such as optic nerve hypoplasia (ONH) and microphthalmia or anophthalmia, or midline forebrain neuroradiological defects including agenesis of the septum pellucidum or corpus callosum or the more severe holoprosencephaly., Evidence Synthesis: Mutations give rise to an array of highly variable disorders ranging in severity. There are many known causative genes in HP developmental pathways that are routinely screened in CH patients; however, over the last 5 years this list has rapidly increased due to the identification of variants in new genes and pathways of interest by next-generation sequencing., Conclusion: The majority of patients with these disorders do not have an identified molecular basis, often making management challenging. This mini-review aims to guide clinicians in making a genetic diagnosis based on patient phenotype, which in turn may impact on clinical management., (© Endocrine Society 2019. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2020
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20. Development of the Pituitary Gland.
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Alatzoglou KS, Gregory LC, and Dattani MT
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- Animals, Humans, Morphogenesis, Pituitary Diseases genetics, Pituitary Diseases metabolism, Pituitary Diseases pathology, Pituitary Gland cytology, Pituitary Gland embryology, Pituitary Gland metabolism, Transcription Factors genetics, Transcription Factors metabolism, Pituitary Gland growth & development
- Abstract
The development of the anterior pituitary gland occurs in distinct sequential developmental steps, leading to the formation of a complex organ containing five different cell types secreting six different hormones. During this process, the temporal and spatial expression of a cascade of signaling molecules and transcription factors plays a crucial role in organ commitment, cell proliferation, patterning, and terminal differentiation. The morphogenesis of the gland and the emergence of distinct cell types from a common primordium are governed by complex regulatory networks involving transcription factors and signaling molecules that may be either intrinsic to the developing pituitary or extrinsic, originating from the ventral diencephalon, the oral ectoderm, and the surrounding mesenchyme. Endocrine cells of the pituitary gland are organized into structural and functional networks that contribute to the coordinated response of endocrine cells to stimuli; these cellular networks are formed during embryonic development and are maintained or may be modified in adulthood, contributing to the plasticity of the gland. Abnormalities in any of the steps of pituitary development may lead to congenital hypopituitarism that includes a spectrum of disorders from isolated to combined hormone deficiencies including syndromic disorders such as septo-optic dysplasia. Over the past decade, the acceleration of next-generation sequencing has allowed for rapid analysis of the patient genome to identify novel mutations and novel candidate genes associated with hypothalmo-pituitary development. Subsequent functional analysis using patient fibroblast cells, and the generation of stem cells derived from patient cells, is fast replacing the need for animal models while providing a more physiologically relevant characterization of novel mutations. Furthermore, CRISPR-Cas9 as the method for gene editing is replacing previous laborious and time-consuming gene editing methods that were commonly used, thus yielding knockout cell lines in a fraction of the time. © 2020 American Physiological Society. Compr Physiol 10:389-413, 2020., (Copyright © 2020 American Physiological Society. All rights reserved.)
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- 2020
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21. Mutations in MAGEL2 and L1CAM Are Associated With Congenital Hypopituitarism and Arthrogryposis.
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Gregory LC, Shah P, Sanner JRF, Arancibia M, Hurst J, Jones WD, Spoudeas H, Le Quesne Stabej P, Williams HJ, Ocaka LA, Loureiro C, Martinez-Aguayo A, and Dattani MT
- Subjects
- Child, Child, Preschool, Diencephalon metabolism, Female, Humans, Hypothalamus metabolism, Infant, Infant, Newborn, Male, Mutation, Pedigree, Phenotype, Exome Sequencing, Arthrogryposis genetics, Genetic Diseases, X-Linked genetics, Hypopituitarism congenital, Neural Cell Adhesion Molecule L1 genetics, Proteins genetics
- Abstract
Context: Congenital hypopituitarism (CH) is rarely observed in combination with severe joint contractures (arthrogryposis). Schaaf-Yang syndrome (SHFYNG) phenotypically overlaps with Prader-Willi syndrome, with patients also manifesting arthrogryposis. L1 syndrome, a group of X-linked disorders that include hydrocephalus and lower limb spasticity, also rarely presents with arthrogryposis., Objective: We investigated the molecular basis underlying the combination of CH and arthrogryposis in five patients., Patients: The heterozygous p.Q666fs*47 mutation in the maternally imprinted MAGEL2 gene, previously described in multiple patients with SHFYNG, was identified in patients 1 to 4, all of whom manifested growth hormone deficiency and variable SHFYNG features, including dysmorphism, developmental delay, sleep apnea, and visual problems. Nonidentical twins (patients 2 and 3) had diabetes insipidus and macrocephaly, and patient 4 presented with ACTH insufficiency. The hemizygous L1CAM variant p.G452R, previously implicated in patients with L1 syndrome, was identified in patient 5, who presented with antenatal hydrocephalus., Results: Human embryonic expression analysis revealed MAGEL2 transcripts in the developing hypothalamus and ventral diencephalon at Carnegie stages (CSs) 19, 20, and 23 and in the Rathke pouch at CS20 and CS23. L1CAM was expressed in the developing hypothalamus, ventral diencephalon, and hindbrain (CS19, CS20, CS23), but not in the Rathke pouch., Conclusion: We report MAGEL2 and L1CAM mutations in four pedigrees with variable CH and arthrogryposis. Patients presenting early in life with this combined phenotype should be examined for features of SHFYNG and/or L1 syndrome. This study highlights the association of hypothalamo-pituitary disease with MAGEL2 and L1CAM mutations., (Copyright © 2019 Endocrine Society.)
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- 2019
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22. Impaired EIF2S3 function associated with a novel phenotype of X-linked hypopituitarism with glucose dysregulation.
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Gregory LC, Ferreira CB, Young-Baird SK, Williams HJ, Harakalova M, van Haaften G, Rahman SA, Gaston-Massuet C, Kelberman D, GOSgene, Qasim W, Camper SA, Dever TE, Shah P, Robinson ICAF, and Dattani MT
- Subjects
- Amino Acid Substitution, Apoptosis, Brain diagnostic imaging, Brain metabolism, Cell Line, Child, Preschool, Eukaryotic Initiation Factor-2 chemistry, Eukaryotic Initiation Factor-2 metabolism, Gene Knockdown Techniques, Humans, Hypopituitarism diagnosis, In Situ Hybridization, Infant, Magnetic Resonance Imaging, Mutation, Pedigree, Polymorphism, Single Nucleotide, Protein Biosynthesis, Eukaryotic Initiation Factor-2 genetics, Genes, X-Linked, Glucose metabolism, Hypopituitarism etiology, Hypopituitarism metabolism, Phenotype
- Abstract
Background: The heterotrimeric GTP-binding protein eIF2 forms a ternary complex with initiator methionyl-tRNA and recruits it to the 40S ribosomal subunit for start codon selection and thereby initiates protein synthesis. Mutations in EIF2S3, encoding the eIF2γ subunit, are associated with severe intellectual disability and microcephaly, usually as part of MEHMO syndrome., Methods: Exome sequencing of the X chromosome was performed on three related males with normal head circumferences and mild learning difficulties, hypopituitarism (GH and TSH deficiencies), and an unusual form of glucose dysregulation. In situ hybridisation on human embryonic tissue, EIF2S3-knockdown studies in a human pancreatic cell line, and yeast assays on the mutated corresponding eIF2γ protein, were performed in this study., Findings: We report a novel hemizygous EIF2S3 variant, p.Pro432Ser, in the three boys (heterozygous in their mothers). EIF2S3 expression was detectable in the developing pituitary gland and pancreatic islets of Langerhans. Cells lacking EIF2S3 had increased caspase activity/cell death. Impaired protein synthesis and relaxed start codon selection stringency was observed in mutated yeast., Interpretation: Our data suggest that the p.Pro432Ser mutation impairs eIF2γ function leading to a relatively mild novel phenotype compared with previous EIF2S3 mutations. Our studies support a critical role for EIF2S3 in human hypothalamo-pituitary development and function, and glucose regulation, expanding the range of phenotypes associated with EIF2S3 mutations beyond classical MEHMO syndrome. Untreated hypoglycaemia in previous cases may have contributed to their more severe neurological impairment and seizures in association with impaired EIF2S3. FUND: GOSH, MRF, BRC, MRC/Wellcome Trust and NIGMS funded this study., (Copyright © 2019. Published by Elsevier B.V.)
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- 2019
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23. Near-field fault slip of the 2016 Vettore M w 6.6 earthquake (Central Italy) measured using low-cost GNSS.
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Wilkinson MW, McCaffrey KJW, Jones RR, Roberts GP, Holdsworth RE, Gregory LC, Walters RJ, Wedmore L, Goodall H, and Iezzi F
- Abstract
The temporal evolution of slip on surface ruptures during an earthquake is important for assessing fault displacement, defining seismic hazard and for predicting ground motion. However, measurements of near-field surface displacement at high temporal resolution are elusive. We present a novel record of near-field co-seismic displacement, measured with 1-second temporal resolution during the 30
th October 2016 Mw 6.6 Vettore earthquake (Central Italy), using low-cost Global Navigation Satellite System (GNSS) receivers located in the footwall and hangingwall of the Mt. Vettore - Mt. Bove fault system, close to new surface ruptures. We observe a clear temporal and spatial link between our near-field record and InSAR, far-field GPS data, regional measurements from the Italian Strong Motion and National Seismic networks, and field measurements of surface ruptures. Comparison of these datasets illustrates that the observed surface ruptures are the propagation of slip from depth on a surface rupturing (i.e. capable) fault array, as a direct and immediate response to the 30th October earthquake. Large near-field displacement ceased within 6-8 seconds of the origin time, implying that shaking induced gravitational processes were not the primary driving mechanism. We demonstrate that low-cost GNSS is an accurate monitoring tool when installed as custom-made, short-baseline networks.- Published
- 2017
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24. Orogen-scale uplift in the central Italian Apennines drives episodic behaviour of earthquake faults.
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Cowie PA, Phillips RJ, Roberts GP, McCaffrey K, Zijerveld LJ, Gregory LC, Faure Walker J, Wedmore LN, Dunai TJ, Binnie SA, Freeman SP, Wilcken K, Shanks RP, Huismans RS, Papanikolaou I, Michetti AM, and Wilkinson M
- Abstract
Many areas of the Earth's crust deform by distributed extensional faulting and complex fault interactions are often observed. Geodetic data generally indicate a simpler picture of continuum deformation over decades but relating this behaviour to earthquake occurrence over centuries, given numerous potentially active faults, remains a global problem in hazard assessment. We address this challenge for an array of seismogenic faults in the central Italian Apennines, where crustal extension and devastating earthquakes occur in response to regional surface uplift. We constrain fault slip-rates since ~18 ka using variations in cosmogenic
36 Cl measured on bedrock scarps, mapped using LiDAR and ground penetrating radar, and compare these rates to those inferred from geodesy. The36 Cl data reveal that individual faults typically accumulate meters of displacement relatively rapidly over several thousand years, separated by similar length time intervals when slip-rates are much lower, and activity shifts between faults across strike. Our rates agree with continuum deformation rates when averaged over long spatial or temporal scales (104 yr; 102 km) but over shorter timescales most of the deformation may be accommodated by <30% of the across-strike fault array. We attribute the shifts in activity to temporal variations in the mechanical work of faulting.- Published
- 2017
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25. Partial Loss of Function of the GHRH Receptor Leads to Mild Growth Hormone Deficiency.
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Gregory LC, Alatzoglou KS, McCabe MJ, Hindmarsh PC, Saldanha JW, Romano N, Le Tissier P, and Dattani MT
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- Adolescent, Child, Consanguinity, Female, Humans, Male, Mutation, Missense, Pakistan, Pedigree, Phenotype, Dwarfism, Pituitary genetics, Dwarfism, Pituitary physiopathology, Receptors, Neuropeptide genetics, Receptors, Pituitary Hormone-Regulating Hormone genetics
- Abstract
Objective: Recessive mutations in GHRHR are associated with severe isolated growth hormone deficiency (IGHD), with a final height in untreated patients of 130 cm ± 10 cm (-7.2 ± 1.6 SDS; males) and 114 ± 0.7 cm (-8.3 ± 0.1 SDS; females)., Design: We hypothesized that a consanguineous Pakistani family with IGHD in three siblings (two males, one female) would have mutations in GH1 or GHRHR., Results: Two novel homozygous missense variants [c.11G>A (p.R4Q), c.236C>T (p.P79L)] at conserved residues were identified in all three siblings. Both were absent from control databases, aside from pR4Q appearing once in heterozygous form in the Exome Aggregation Consortium Browser. The brothers were diagnosed with GH deficiency at 9.8 and 6.0 years (height SDS: -2.24 and -1.23, respectively), with a peak GH of 2.9 μg/liter with low IGF-1/IGF binding protein 3. Their sister presented at 16 years with classic GH deficiency (peak GH <0.1 μg/liter, IGF-1 <3.3 mmol/liter) and attained an untreated near-adult height of 144 cm (-3.0 SDS); the tallest untreated patient with GHRHR mutations reported. An unrelated Pakistani female IGHD patient was also compound homozygous. All patients had a small anterior pituitary on magnetic resonance imaging. Functional analysis revealed a 50% reduction in maximal cAMP response to stimulation with GHRH by the p.R4Q/p.P79L double mutant receptor, with a 100-fold increase in EC50., Conclusion: We report the first coexistence of two novel compound homozygous GHRHR variants in two unrelated pedigrees associated with a partial loss of function. Surprisingly, the patients have a relatively mild IGHD phenotype. Analysis revealed that the pP79L mutation is associated with the compromise in function, with the residual partial activity explaining the mild phenotype.
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- 2016
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26. Transcription factor 7-like 1 is involved in hypothalamo-pituitary axis development in mice and humans.
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Gaston-Massuet C, McCabe MJ, Scagliotti V, Young RM, Carreno G, Gregory LC, Jayakody SA, Pozzi S, Gualtieri A, Basu B, Koniordou M, Wu CI, Bancalari RE, Rahikkala E, Veijola R, Lopponen T, Graziola F, Turton J, Signore M, Mousavy Gharavy SN, Charolidi N, Sokol SY, Andoniadou CL, Wilson SW, Merrill BJ, Dattani MT, and Martinez-Barbera JP
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- Animals, Cohort Studies, Humans, Mice, Pituitary Gland abnormalities, Pituitary Gland metabolism, Pituitary Gland physiopathology, Prosencephalon abnormalities, Prosencephalon metabolism, Hypothalamo-Hypophyseal System, Transcription Factor 7-Like 1 Protein physiology
- Abstract
Aberrant embryonic development of the hypothalamus and/or pituitary gland in humans results in congenital hypopituitarism (CH). Transcription factor 7-like 1 (TCF7L1), an important regulator of the WNT/β-catenin signaling pathway, is expressed in the developing forebrain and pituitary gland, but its role during hypothalamo-pituitary (HP) axis formation or involvement in human CH remains elusive. Using a conditional genetic approach in the mouse, we first demonstrate that TCF7L1 is required in the prospective hypothalamus to maintain normal expression of the hypothalamic signals involved in the induction and subsequent expansion of Rathke's pouch progenitors. Next, we reveal that the function of TCF7L1 during HP axis development depends exclusively on the repressing activity of TCF7L1 and does not require its interaction with β-catenin. Finally, we report the identification of two independent missense variants in human TCF7L1, p.R92P and p.R400Q, in a cohort of patients with forebrain and/or pituitary defects. We demonstrate that these variants exhibit reduced repressing activity in vitro and in vivo relative to wild-type TCF7L1. Together, our data provide support for a conserved molecular function of TCF7L1 as a transcriptional repressor during HP axis development in mammals and identify variants in this transcription factor that are likely to contribute to the etiology of CH.
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- 2016
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27. Novel application of luciferase assay for the in vitro functional assessment of KAL1 variants in three females with septo-optic dysplasia (SOD).
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McCabe MJ, Hu Y, Gregory LC, Gaston-Massuet C, Alatzoglou KS, Saldanha JW, Gualtieri A, Thankamony A, Hughes I, Townshend S, Martinez-Barbera JP, Bouloux PM, and Dattani MT
- Subjects
- Animals, COS Cells, Chlorocebus aethiops, Female, Humans, In Vitro Techniques, Models, Molecular, Pedigree, Pituitary Gland metabolism, Septo-Optic Dysplasia metabolism, Septo-Optic Dysplasia pathology, Extracellular Matrix Proteins genetics, Extracellular Matrix Proteins metabolism, Luciferases metabolism, Nerve Tissue Proteins genetics, Nerve Tissue Proteins metabolism, Polymorphism, Single Nucleotide, Septo-Optic Dysplasia genetics
- Abstract
KAL1 is implicated in 5% of Kallmann syndrome cases, a disorder which genotypically overlaps with septo-optic dysplasia (SOD). To date, a reporter-based assay to assess the functional consequences of KAL1 mutations is lacking. We aimed to develop a luciferase assay for novel application to functional assessment of rare KAL1 mutations detected in a screen of 422 patients with SOD. Quantitative analysis was performed using L6-myoblasts stably expressing FGFR1, transfected with a luciferase-reporter vector containing elements of the FGF-responsive osteocalcin promoter. The two variants assayed [p.K185N, p.P291T], were detected in three females with SOD (presenting with optic nerve hypoplasia, midline and pituitary defects). Our novel assay revealed significant decreases in transcriptional activity [p.K185N: 21% (p < 0.01); p.P291T: 40% (p < 0.001)]. Our luciferase-reporter assay, developed for assessment of KAL1 mutations, determined that two variants in females with hypopituitarism/SOD are loss-of-function; demonstrating that this assay is suitable for quantitative assessment of mutations in this gene., (Copyright © 2015 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.)
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- 2015
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28. Novel Lethal Form of Congenital Hypopituitarism Associated With the First Recessive LHX4 Mutation.
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Gregory LC, Humayun KN, Turton JP, McCabe MJ, Rhodes SJ, and Dattani MT
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- Base Sequence, Female, Genes, Recessive, HEK293 Cells, Humans, Infant, Newborn, LIM-Homeodomain Proteins chemistry, Male, Models, Molecular, Pedigree, Siblings, Transcription Factors chemistry, Genes, Lethal, Hypopituitarism congenital, Hypopituitarism genetics, LIM-Homeodomain Proteins genetics, Mutation, Missense, Perinatal Death, Transcription Factors genetics
- Abstract
Background: LHX4 encodes a member of the LIM-homeodomain family of transcription factors that is required for normal development of the pituitary gland. To date, only incompletely penetrant heterozygous mutations in LHX4 have been described in patients with variable combined pituitary hormone deficiencies., Objective/hypothesis: To report a unique family with a novel recessive variant in LHX4 associated with a lethal form of congenital hypopituitarism that was identified through screening a total of 97 patients., Method: We screened 97 unrelated patients with combined pituitary hormone deficiency, including 65% with an ectopic posterior pituitary, for variants in the LHX4 gene using Sanger sequencing. Control databases (1000 Genomes, dbSNP, Exome Variant Server, ExAC Browser) were consulted upon identification of variants., Results: We identified the first novel homozygous missense variant (c.377C>T, p.T126M) in two deceased male patients of Pakistani origin with severe panhypopituitarism associated with anterior pituitary aplasia and posterior pituitary ectopia. Both were born small for gestational age with a small phallus, undescended testes, and mid-facial hypoplasia. The parents' first-born child was a female with mid-facial hypoplasia (DNA was unavailable). Despite rapid commencement of hydrocortisone and T4 in the brothers, all three children died within the first week of life. The LHX4(p.T126M) variant is located within the LIM2 domain, in a highly conserved location. The absence of homozygosity for the variant in over 65 000 controls suggests that it is likely to be responsible for the phenotype., Conclusion: We report, for the first time to our knowledge, a novel homozygous mutation in LHX4 associated with a lethal phenotype, implying that recessive mutations in LHX4 may be incompatible with life.
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- 2015
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29. The role of the sonic hedgehog signalling pathway in patients with midline defects and congenital hypopituitarism.
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Gregory LC, Gaston-Massuet C, Andoniadou CL, Carreno G, Webb EA, Kelberman D, McCabe MJ, Panagiotakopoulos L, Saldanha JW, Spoudeas HA, Torpiano J, Rossi M, Raine J, Canham N, Martinez-Barbera JP, and Dattani MT
- Subjects
- Adolescent, Animals, Cell Cycle Proteins genetics, Child, Child, Preschool, Cohort Studies, Enhancer Elements, Genetic genetics, Female, GPI-Linked Proteins genetics, Gene Deletion, Genetic Variation, Heterozygote, Holoprosencephaly metabolism, Humans, Hypopituitarism congenital, Hypopituitarism metabolism, Kruppel-Like Transcription Factors genetics, Male, Mice, Mutation, NIH 3T3 Cells, Nuclear Proteins genetics, Phenotype, Sequence Analysis, DNA, Zinc Finger Protein Gli2, Zinc Fingers, Gene Expression Regulation, Hedgehog Proteins genetics, Hypopituitarism blood, Signal Transduction
- Abstract
Introduction: The Gli family of zinc finger (GLI) transcription factors mediates the sonic hedgehog signalling pathway (HH) essential for CNS, early pituitary and ventral forebrain development in mice. Human mutations in this pathway have been described in patients with holoprosencephaly (HPE), isolated congenital hypopituitarism (CH) and cranial/midline facial abnormalities. Mutations in Sonic hedgehog (SHH) have been associated with HPE but not CH, despite murine studies indicating involvement in pituitary development., Objectives/methods: We aimed to establish the role of the HH pathway in the aetiology of hypothalamo-pituitary disorders by screening our cohort of patients with midline defects and/or CH for mutations in SHH, GLI2, Shh brain enhancer 2 (SBE2) and growth-arrest specific 1 (GAS1)., Results: Two variants and a deletion of GLI2 were identified in three patients. A novel variant at a highly conserved residue in the zinc finger DNA-binding domain, c.1552G > A [pE518K], was identified in a patient with growth hormone deficiency and low normal free T4. A nonsynonymous variant, c.2159G > A [p.R720H], was identified in a patient with a short neck, cleft palate and hypogonadotrophic hypogonadism. A 26·6 Mb deletion, 2q12·3-q21·3, encompassing GLI2 and 77 other genes, was identified in a patient with short stature and impaired growth. Human embryonic expression studies and molecular characterisation of the GLI2 mutant p.E518K support the potential pathogenicity of GLI2 mutations. No mutations were identified in GAS1 or SBE2. A novel SHH variant, c.1295T>A [p.I432N], was identified in two siblings with variable midline defects but normal pituitary function., Conclusions: Our data suggest that mutations in SHH, GAS1 and SBE2 are not associated with hypopituitarism, although GLI2 is an important candidate for CH., (© 2014 John Wiley & Sons Ltd.)
- Published
- 2015
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30. Neuropathy target esterase impairments cause Oliver-McFarlane and Laurence-Moon syndromes.
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Hufnagel RB, Arno G, Hein ND, Hersheson J, Prasad M, Anderson Y, Krueger LA, Gregory LC, Stoetzel C, Jaworek TJ, Hull S, Li A, Plagnol V, Willen CM, Morgan TM, Prows CA, Hegde RS, Riazuddin S, Grabowski GA, Richardson RJ, Dieterich K, Huang T, Revesz T, Martinez-Barbera JP, Sisk RA, Jefferies C, Houlden H, Dattani MT, Fink JK, Dollfus H, Moore AT, and Ahmed ZM
- Subjects
- Alleles, Amino Acid Sequence, Animals, Carboxylic Ester Hydrolases chemistry, Central Nervous System pathology, Developmental Disabilities enzymology, Developmental Disabilities genetics, Embryonic Development genetics, Gene Expression Regulation, Developmental, Humans, Molecular Sequence Data, Mutation genetics, Phenotype, Phospholipases chemistry, Phospholipases genetics, Protein Structure, Tertiary, Retina pathology, Zebrafish embryology, Blepharoptosis enzymology, Blepharoptosis genetics, Carboxylic Ester Hydrolases genetics, Dwarfism enzymology, Dwarfism genetics, Genetic Predisposition to Disease, Hypertrichosis enzymology, Hypertrichosis genetics, Intellectual Disability enzymology, Intellectual Disability genetics, Laurence-Moon Syndrome enzymology, Laurence-Moon Syndrome genetics, Retinitis Pigmentosa enzymology, Retinitis Pigmentosa genetics
- Abstract
Background: Oliver-McFarlane syndrome is characterised by trichomegaly, congenital hypopituitarism and retinal degeneration with choroidal atrophy. Laurence-Moon syndrome presents similarly, though with progressive spinocerebellar ataxia and spastic paraplegia and without trichomegaly. Both recessively inherited disorders have no known genetic cause., Methods: Whole-exome sequencing was performed to identify the genetic causes of these disorders. Mutations were functionally validated in zebrafish pnpla6 morphants. Embryonic expression was evaluated via in situ hybridisation in human embryonic sections. Human neurohistopathology was performed to characterise cerebellar degeneration. Enzymatic activities were measured in patient-derived fibroblast cell lines., Results: Eight mutations in six families with Oliver-McFarlane or Laurence-Moon syndrome were identified in the PNPLA6 gene, which encodes neuropathy target esterase (NTE). PNPLA6 expression was found in the developing human eye, pituitary and brain. In zebrafish, the pnpla6 curly-tailed morphant phenotype was fully rescued by wild-type human PNPLA6 mRNA and not by mutation-harbouring mRNAs. NTE enzymatic activity was significantly reduced in fibroblast cells derived from individuals with Oliver-McFarlane syndrome. Intriguingly, adult brain histology from a patient with highly overlapping features of Oliver-McFarlane and Laurence-Moon syndromes revealed extensive cerebellar degeneration and atrophy., Conclusions: Previously, PNPLA6 mutations have been associated with spastic paraplegia type 39, Gordon-Holmes syndrome and Boucher-Neuhäuser syndromes. Discovery of these additional PNPLA6-opathies further elucidates a spectrum of neurodevelopmental and neurodegenerative disorders associated with NTE impairment and suggests a unifying mechanism with diagnostic and prognostic importance., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)
- Published
- 2015
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31. "There's an app for that" bringing nursing education to the bedside.
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Gregory LC, Lowder E, and Issah F
- Subjects
- Attitude to Computers, Humans, United States, Computers, Handheld, Nursing Informatics education, Point-of-Care Systems, Software
- Abstract
Although many educators may not consider themselves technologically savvy, the reality is that the use of technology in nursing education is sharply rising and we must meet the needs of the adult learner. Now more than ever, learners utilize technology for their daily lives and actually prefer this form of education. The use of iPads can greatly impact nursing education which not only engages the staff, but provides an environment that is conducive to learning, is cost effective, and fun. iPads really do have an app for that!
- Published
- 2013
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32. Structural pituitary abnormalities associated with CHARGE syndrome.
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Gregory LC, Gevers EF, Baker J, Kasia T, Chong K, Josifova DJ, Caimari M, Bilan F, McCabe MJ, and Dattani MT
- Subjects
- Amino Acid Sequence, Base Sequence, CHARGE Syndrome epidemiology, CHARGE Syndrome genetics, Child, Cohort Studies, Consensus Sequence, DNA Helicases genetics, DNA Mutational Analysis, DNA-Binding Proteins genetics, Humans, Hypopituitarism epidemiology, Hypopituitarism etiology, Hypopituitarism genetics, Male, Models, Biological, Septo-Optic Dysplasia complications, Septo-Optic Dysplasia epidemiology, Septo-Optic Dysplasia genetics, CHARGE Syndrome complications, Hypopituitarism complications, Pituitary Gland abnormalities
- Abstract
Introduction: CHARGE syndrome is a multisystem disorder that, in addition to Kallmann syndrome/isolated hypogonadotrophic hypogonadism, has been associated with anterior pituitary hypoplasia (APH). However, structural abnormalities such as an ectopic posterior pituitary (EPP) have not yet been described in such patients., Objective: The aims of the study were: 1) to describe the association between CHARGE syndrome and a structurally abnormal pituitary gland; and 2) to investigate whether CHD7 variants, which are identified in 65% of CHARGE patients, are common in septo-optic dysplasia /hypopituitarism., Methods: We describe 2 patients with features of CHARGE and EPP. CHD7 was sequenced in these and other patients with septo-optic dysplasia/hypopituitarism., Results: EPP, APH, and GH, TSH, and probable LH/FSH deficiency were present in 1 patient, and EPP and APH with GH, TSH, LH/FSH, and ACTH deficiency were present in another patient, both of whom had features of CHARGE syndrome. Both had variations in CHD7 that were novel and undetected in control cohorts or in the international database of CHARGE patients, but were also present in their unaffected mothers. No CHD7 variants were detected in the patients with septo-optic dysplasia/hypopituitarism without additional CHARGE features., Conclusion: We report a novel association between CHARGE syndrome and structural abnormalities of the pituitary gland in 2 patients with variations in CHD7 that are of unknown significance. However, CHD7 mutations are an uncommon cause of septo-optic dysplasia or hypopituitarism. Our data suggest the need for evaluation of pituitary function/anatomy in patients with CHARGE syndrome.
- Published
- 2013
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33. Variations in PROKR2, but not PROK2, are associated with hypopituitarism and septo-optic dysplasia.
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McCabe MJ, Gaston-Massuet C, Gregory LC, Alatzoglou KS, Tziaferi V, Sbai O, Rondard P, Masumoto KH, Nagano M, Shigeyoshi Y, Pfeifer M, Hulse T, Buchanan CR, Pitteloud N, Martinez-Barbera JP, and Dattani MT
- Subjects
- Animals, Child, Child, Preschool, Cohort Studies, Female, Genetic Testing, Genotype, HEK293 Cells, Heterozygote, Homozygote, Humans, Hypopituitarism congenital, Hypothalamo-Hypophyseal System embryology, Hypothalamo-Hypophyseal System physiology, Infant, Infant, Newborn, Male, Mice, Mice, Knockout, Pedigree, Phenotype, Gastrointestinal Hormones genetics, Hypopituitarism genetics, Kallmann Syndrome genetics, Neuropeptides genetics, Receptors, G-Protein-Coupled genetics, Receptors, Peptide genetics, Septo-Optic Dysplasia genetics
- Abstract
Context: Loss-of-function mutations in PROK2 and PROKR2 have been implicated in Kallmann syndrome (KS), characterized by hypogonadotropic hypogonadism and anosmia. Recent data suggest overlapping phenotypes/genotypes between KS and congenital hypopituitarism (CH), including septo-optic dysplasia (SOD)., Objective: We screened a cohort of patients with complex forms of CH (n = 422) for mutations in PROK2 and PROKR2., Results: We detected 5 PROKR2 variants in 11 patients with SOD/CH: novel p.G371R and previously reported p.A51T, p.R85L, p.L173R, and p.R268C-the latter 3 being known functionally deleterious variants. Surprisingly, 1 patient with SOD was heterozygous for the p.L173R variant, whereas his phenotypically unaffected mother was homozygous for the variant. We sought to clarify the role of PROKR2 in hypothalamopituitary development through analysis of Prokr2(-/-) mice. Interestingly, these revealed predominantly normal hypothalamopituitary development and terminal cell differentiation, with the exception of reduced LH; this was inconsistent with patient phenotypes and more analogous to the healthy mother, although she did not have KS, unlike the Prokr2(-/-) mice., Conclusions: The role of PROKR2 in the etiology of CH, SOD, and KS is uncertain, as demonstrated by no clear phenotype-genotype correlation; loss-of-function variants in heterozygosity or homozygosity can be associated with these disorders. However, we report a phenotypically normal parent, homozygous for p.L173R. Our data suggest that the variants identified herein are unlikely to be implicated in isolation in these disorders; other genetic or environmental modifiers may also impact on the etiology. Given the phenotypic variability, genetic counseling may presently be inappropriate.
- Published
- 2013
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34. Genetic overlap in Kallmann syndrome, combined pituitary hormone deficiency, and septo-optic dysplasia.
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Raivio T, Avbelj M, McCabe MJ, Romero CJ, Dwyer AA, Tommiska J, Sykiotis GP, Gregory LC, Diaczok D, Tziaferi V, Elting MW, Padidela R, Plummer L, Martin C, Feng B, Zhang C, Zhou QY, Chen H, Mohammadi M, Quinton R, Sidis Y, Radovick S, Dattani MT, and Pitteloud N
- Subjects
- Animals, Female, Fibroblast Growth Factor 8 metabolism, Genetic Association Studies, Heterozygote, Humans, Hypopituitarism metabolism, Kallmann Syndrome metabolism, Male, Mice, Mice, Transgenic, Nerve Tissue Proteins genetics, Nerve Tissue Proteins metabolism, Neurons metabolism, Neurons pathology, Pituitary Gland, Posterior metabolism, Pituitary Gland, Posterior pathology, Receptors, G-Protein-Coupled metabolism, Receptors, Peptide metabolism, Recombinant Fusion Proteins metabolism, Septo-Optic Dysplasia metabolism, Signal Transduction, United Kingdom, United States, Fibroblast Growth Factor 8 genetics, Hypopituitarism genetics, Kallmann Syndrome genetics, Mutation, Receptor, Fibroblast Growth Factor, Type 1 genetics, Receptors, G-Protein-Coupled genetics, Receptors, Peptide genetics, Septo-Optic Dysplasia genetics
- Abstract
Context: Kallmann syndrome (KS), combined pituitary hormone deficiency (CPHD), and septo-optic dysplasia (SOD) all result from development defects of the anterior midline in the human forebrain., Objective: The objective of the study was to investigate whether KS, CPHD, and SOD have shared genetic origins., Design and Participants: A total of 103 patients with either CPHD (n = 35) or SOD (n = 68) were investigated for mutations in genes implicated in the etiology of KS (FGFR1, FGF8, PROKR2, PROK2, and KAL1). Consequences of identified FGFR1, FGF8, and PROKR2 mutations were investigated in vitro., Results: Three patients with SOD had heterozygous mutations in FGFR1; these were either shown to alter receptor signaling (p.S450F, p.P483S) or predicted to affect splicing (c.336C>T, p.T112T). One patient had a synonymous change in FGF8 (c.216G>A, p.T72T) that was shown to affect splicing and ligand signaling activity. Four patients with CPHD/SOD were found to harbor heterozygous rare loss-of-function variants in PROKR2 (p.R85G, p.R85H, p.R268C)., Conclusions: Mutations in FGFR1/FGF8/PROKR2 contributed to 7.8% of our patients with CPHD/SOD. These data suggest a significant genetic overlap between conditions affecting the development of anterior midline in the human forebrain.
- Published
- 2012
- Full Text
- View/download PDF
35. Pituitary gland development: an update.
- Author
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Bancalari RE, Gregory LC, McCabe MJ, and Dattani MT
- Subjects
- Abnormalities, Multiple embryology, Abnormalities, Multiple etiology, Abnormalities, Multiple genetics, Animals, Endocrinology methods, Humans, Hypopituitarism complications, Hypopituitarism congenital, Hypopituitarism embryology, Hypopituitarism genetics, Models, Biological, Organogenesis genetics, Organogenesis physiology, Pituitary Gland anatomy & histology, Pituitary Gland physiology, Endocrinology trends, Pituitary Gland embryology, Pituitary Gland growth & development
- Abstract
The embryonic development of the pituitary gland involves a complex and highly spatio-temporally regulated network of integrating signalling molecules and transcription factors. Genetic mutations in any of these factors can lead to congenital hypopituitarism in association with a wide spectrum of craniofacial/midline defects ranging from incompatibility with life to holoprosencephaly (HPE) and cleft palate and septo-optic dysplasia (SOD). Increasing evidence supports a genotypic overlap with hypogonadotrophic hypogonadal disorders such as Kallmann syndrome, which is consistent with the known overlap in phenotypes between these disorders. This chapter reviews the cascade of events leading up to the successful development of the pituitary gland and to highlight key areas where genetic variations can occur thus leading to congenital hypopituitarism and associated defects., (Copyright © 2012 S. Karger AG, Basel.)
- Published
- 2012
- Full Text
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36. Novel FGF8 mutations associated with recessive holoprosencephaly, craniofacial defects, and hypothalamo-pituitary dysfunction.
- Author
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McCabe MJ, Gaston-Massuet C, Tziaferi V, Gregory LC, Alatzoglou KS, Signore M, Puelles E, Gerrelli D, Farooqi IS, Raza J, Walker J, Kavanaugh SI, Tsai PS, Pitteloud N, Martinez-Barbera JP, and Dattani MT
- Subjects
- Agenesis of Corpus Callosum complications, Agenesis of Corpus Callosum genetics, Arginine Vasopressin metabolism, DNA Mutational Analysis, Female, Fibroblast Growth Factor 8 physiology, Human Growth Hormone blood, Humans, Hydrocortisone blood, Immunohistochemistry, In Situ Hybridization, Infant, Magnetic Resonance Imaging, Pituitary Gland growth & development, Pituitary Gland physiology, Prosencephalon growth & development, Prosencephalon physiology, Receptor, Fibroblast Growth Factor, Type 1 biosynthesis, Receptor, Fibroblast Growth Factor, Type 1 genetics, Septo-Optic Dysplasia genetics, Thyrotropin blood, Craniofacial Abnormalities genetics, Fibroblast Growth Factor 8 genetics, Holoprosencephaly genetics, Hypothalamic Diseases genetics, Hypothalamo-Hypophyseal System physiopathology, Mutation physiology, Pituitary Diseases genetics
- Abstract
Context: Fibroblast growth factor (FGF) 8 is important for GnRH neuronal development with human mutations resulting in Kallmann syndrome. Murine data suggest a role for Fgf8 in hypothalamo-pituitary development; however, its role in the etiology of wider hypothalamo-pituitary dysfunction in humans is unknown., Objective: The objective of this study was to screen for FGF8 mutations in patients with septo-optic dysplasia (n = 374) or holoprosencephaly (HPE)/midline clefts (n = 47)., Methods: FGF8 was analyzed by PCR and direct sequencing. Ethnically matched controls were then screened for mutated alleles (n = 480-686). Localization of Fgf8/FGF8 expression was analyzed by in situ hybridization in developing murine and human embryos. Finally, Fgf8 hypomorphic mice (Fgf8(loxPNeo/-)) were analyzed for the presence of forebrain and hypothalamo-pituitary defects., Results: A homozygous p.R189H mutation was identified in a female patient of consanguineous parentage with semilobar HPE, diabetes insipidus, and TSH and ACTH insufficiency. Second, a heterozygous p.Q216E mutation was identified in a female patient with an absent corpus callosum, hypoplastic optic nerves, and Moebius syndrome. FGF8 was expressed in the ventral diencephalon and anterior commissural plate but not in Rathke's pouch, strongly suggesting early onset hypothalamic and corpus callosal defects in these patients. This was consolidated by significantly reduced vasopressin and oxytocin staining neurons in the hypothalamus of Fgf8 hypomorphic mice compared with controls along with variable hypothalamo-pituitary defects and HPE., Conclusion: We implicate FGF8 in the etiology of recessive HPE and potentially septo-optic dysplasia/Moebius syndrome for the first time to our knowledge. Furthermore, FGF8 is important for the development of the ventral diencephalon, hypothalamus, and pituitary.
- Published
- 2011
- Full Text
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37. Manufacture of measles viruses.
- Author
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Langfield KK, Walker HJ, Gregory LC, and Federspiel MJ
- Subjects
- Animals, Cell Line, Culture Media, Conditioned chemistry, Endodeoxyribonucleases chemistry, Endoribonucleases chemistry, Filtration instrumentation, Filtration methods, Humans, Measles virus growth & development, Measles virus isolation & purification, Oncolytic Virotherapy methods, Titrimetry methods, Virion growth & development, Virion isolation & purification, Cell Culture Techniques, Measles virus genetics, Virion genetics
- Abstract
Measles viruses have shown potent oncolytic activity as a therapeutic against a variety of human cancers in animal models and are currently being tested in clinical trials in patients. In contrast to using measles virus as a vaccine, oncolytic activity depends on high concentrations of infectious virus. For use in humans, the high-titer measles virus preparations must also be purified to remove significant levels of cellular proteins and nucleic acid resulting from the cytolytic products of measles virus replication and release. Pleomorphic measles virus must be treated as >1-μm particles that are extremely shear sensitive to maximize recoveries and retain infectivity. Therefore, to maximize the recovery of sterile, high titer infectious measles viruses, the entire production and purification process must be done using gentle conditions and aseptic processing. Here we describe a procedure applicable to the production of small (a few liters) to large (50-60 L) batches of measles virus amplified in Vero cells adapted to serum-free growth. Cell culture supernatant containing the measles virus is clarified by filtration to remove intact Vero cells and other debris, and then treated with Benzonase(®) in the presence of magnesium chloride to digest contaminating nucleic acid. The measles virus in the treated cell culture supernatant is then concentrated and purified using tangential flow filtration (TFF) and diafiltration. The concentrated and diafiltered measles virus is passed through a final clarifying filter prior to final vialing and storage at <-65°C. An infectivity assay to quantify infectious measles virus concentration based on the TCID(50) method is also described. This procedure can be readily adapted to the production and purification of measles viruses using good manufacturing practices (GMP).
- Published
- 2011
- Full Text
- View/download PDF
38. In vitro interference of the red cell substitute pyridoxalated hemoglobin-polyoxyethylene with blood compatibility, coagulation, and clinical chemistry testing.
- Author
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Alonsozana GL, Elfath MD, Mackenzie C, Gregory LC, Duh SH, Trump B, and Christenson RH
- Subjects
- Chemistry, Clinical, Humans, Blood Coagulation, Blood Grouping and Crossmatching, Blood Substitutes pharmacology, Hemoglobins pharmacology, Polyethylene Glycols pharmacology
- Abstract
Objectives: Pyridoxalated hemoglobin-polyoxyethylene (PHP) is a prototypical red cell substitute approved for phase I studies. Peripheral blood smears of human blood mixed with PHP in 1 to 4 g/dL concentrations showed dose-dependent red cell aggregation and rouleaux. Whether this aggregation limits interpretation of blood compatibility testing and whether the intense coloration of serum or plasma containing PHP affects routine coagulation and clinical chemistry measurements was tested., Design: In vitro studies., Setting: University hospital laboratory., Participants: Four healthy volunteers, blood types A, B, AB, and O. All were Rh+., Measurements and Main Results: ABO typing, Rh typing, and antibody screening and coagulation studies were performed on blood: PHP admixtures having final concentrations of 1, 2, and 4 g/dL. For clinical chemistry interference studies, known concentrations of analytes were added to a serum matrix containing PHP. ABO (forward) and Rh typing showed no interference in the three concentrations tested. Reverse ABO typing and antibody screening showed rouleaux at 4 g/dL, which corrected with routine saline replacement. Partial thromboplastin time (PTT), prothrombin time (PT), and fibrinogen showed no clinically significant differences from the controls. Results for electrolytes, renal function analytes, and markers of cardiac injury were acceptable by standard laboratory methods. However, results of liver function tests were unacceptable in PHP-containing specimens., Conclusions: PHP-induced aggregation was observed with high PHP concentration; however, compatibility testing was not affected because agglutination was corrected by saline replacement, which is standard practice. Although routine blood banking, coagulation, and most clinical chemistry analytes can be measured reliably, alternative methods and strategies are needed for assessing liver function in the presence of PHP.
- Published
- 1997
- Full Text
- View/download PDF
39. Eight compact analysis systems evaluated for measuring total cholesterol.
- Author
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Gregory LC, Duh SH, and Christenson RH
- Subjects
- Bias, Chemistry, Clinical methods, Chemistry, Clinical statistics & numerical data, Evaluation Studies as Topic, Hemolysis, Humans, Sensitivity and Specificity, Chemistry, Clinical instrumentation, Cholesterol blood
- Abstract
We examined the analytical performance of eight compact systems for measuring total cholesterol: AccuMeter, Cobas Ready, Discovery f2, DT60, L-D-X, Reflotron, QCA, and Vision. We determined average bias at two decision levels, the mean absolute bias, and the percentage of results differing from the comparison method results by > 8.9% allowable total error limit for multiple reagent lots. Average bias was < 3% for all lots tested for AccuMeter, Discovery f2, and DT60, but > 3% for one or more lots or sample types tested with the other systems. Of results from each reagent lot, > 95% were within the 8.9% total error specifications with Discovery f2, DT60, and QCA, whereas the performance of L-D-X, Vision, and Reflotron depended on reagent lot and (or) sample type. Of all results from each lot tested with AccuMeter and Cobas Ready, > 5% exceeded the total allowable error limit. We determined imprecision for five systems: Cobas Ready, Discovery f2, and QCA had CVs < 3%, whereas CVs for AccuMeter and L-D-X were > 3% but < 5%.
- Published
- 1994
40. Suramin interferes with measurements of total calcium and serum amylase by the Kodak Ektachem 700 analyzer and may inhibit liver enzyme activity.
- Author
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Gregory LC, Eisenberger M, Sinibaldi V, and Koch TR
- Subjects
- Autoanalysis standards, False Negative Reactions, Humans, Suramin adverse effects, Alanine Transaminase blood, Amylases blood, Aspartate Aminotransferases blood, Calcium blood, Suramin blood
- Published
- 1992
41. Effects of small C-ANF receptor ligands on plasma levels of atrial natriuretic factor, blood pressure, and renal function in the rat.
- Author
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Okolicany J, McEnroe GA, Gregory LC, Lewicki JA, and Maack T
- Subjects
- Amino Acid Sequence, Animals, Atrial Natriuretic Factor pharmacology, Glomerular Filtration Rate, Iodine Radioisotopes, Kidney Function Tests, Ligands, Male, Molecular Sequence Data, Potassium urine, Rats, Rats, Inbred Strains, Receptors, Atrial Natriuretic Factor, Sodium urine, Urodynamics drug effects, Atrial Natriuretic Factor blood, Blood Pressure drug effects, Kidney drug effects, Receptors, Cell Surface drug effects
- Abstract
In this article, after a very brief review on ANF receptors, we report our study on the effects of small C-ANF receptor ligands in the rat. Two small ligands were synthesized: 2-naphthoxyacetyl-isonipecotyl-rANF11-15-NH2 (5 aa), containing 5 amino acids; and Ala7-rANF8-17-NH2 (10 aa), containing 10 amino acids from the ring structure of ANF1-28. After control periods, 5 aa or 10 aa were infused i.v. at a dose of 10 micrograms.min-1.kg-1 body weight for 70 min in anesthetized rats, followed by a 60-min recovery period. The 5 aa and 10 aa peptides significantly and reversibly increased plasma levels of endogenous immunoreactive ANF by 106 +/- 29 and 52 +/- 24 pg/mL, respectively. Infusion of the 5 aa peptide significantly decreased mean arterial blood pressure from 113 +/- 1 to 100 +/- 3 mmHg (1 mmHg = 133.32 Pa) and increased glomerular filtration rate from 1.6 +/- 0.2 to 2.3 +/- 0.2 mL/min, sodium excretion from 0.6 +/- 0.3 to 3.4 +/- 0.4 mumol/min, and potassium excretion from 0.5 +/- 0.2 to 1.2 +/- 0.2 mumol/min. Similar results were obtained with the 10 aa peptide. The effects of both peptides on blood pressure and sodium excretion persisted throughout the recovery period. The results confirm and extend previous observations showing that C-ANF receptors mediate the removal of ANF from the circulation. The shortening of the minimal peptide length necessary to bind to C-ANF receptors markedly enhances the possibility of developing orally active C-ANF receptor ligands for the treatment of cardiovascular and renal diseases.
- Published
- 1991
- Full Text
- View/download PDF
42. Isolation and functional expression of the human atrial natriuretic peptide clearance receptor cDNA.
- Author
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Porter JG, Arfsten A, Fuller F, Miller JA, Gregory LC, and Lewicki JA
- Subjects
- Amino Acid Sequence, Animals, Atrial Natriuretic Factor metabolism, Base Sequence, Blotting, Northern, DNA isolation & purification, Female, Fetus, Gene Expression, Gene Library, Humans, Kidney metabolism, Lung metabolism, Mice, Molecular Sequence Data, Placenta metabolism, Pregnancy, RNA, Messenger analysis, RNA, Messenger genetics, Receptors, Atrial Natriuretic Factor, Receptors, Cell Surface metabolism, Transfection, DNA genetics, Receptors, Cell Surface genetics
- Abstract
The amino acid sequence of the human atrial natriuretic peptide clearance receptor (ANP C-receptor) was deduced from the nucleotide sequence of cDNA clones obtained from human placental and kidney cDNA libraries. The human sequence is highly homologous to the bovine C-receptor sequence already described, and the corresponding mRNA is expressed in human placenta, adult and fetal kidney and fetal heart. Upon transfection of this cDNA into mammalian cells, recombinant expression experiments revealed that the human ANP C-receptor has a high affinity for ANP (6 x 10(-9) M), similar to that observed for the receptor in other species. These data indicate that the human ANP C-receptor, previously characterized in other mammalian species, is highly conserved structurally and is expressed in various human tissues.
- Published
- 1990
- Full Text
- View/download PDF
43. Effect of renal denervation on the suppression of renin secretion by vasopressin in conscious dogs.
- Author
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Gregory LC and Reid IA
- Subjects
- Angiotensin II pharmacology, Animals, Consciousness, Dogs, Female, Kidney Cortex metabolism, Male, Norepinephrine metabolism, Renin antagonists & inhibitors, Denervation, Kidney innervation, Renin metabolism, Vasopressins physiology
- Abstract
Previous studies have shown that the inhibition of renin secretion by vasopressin (AVP) in conscious dogs is related to vasoconstrictor activity and may be a reflex response mediated by the renal nerves. The aim of the present experiments was to determine whether the suppression of plasma renin activity (PRA) by AVP is blocked by renal denervation. AVP and, for comparison, angiotensin II (ANG II) were infused intravenously for 45 min in seven conscious dogs before and after bilateral renal denervation. Before denervation, AVP infusion at 0.2 and 1.0 ng X kg-1 X min-1 suppressed PRA from 7.4 +/- 1.1 to 4.7 +/- 1.0 (P less than 0.01) and from 7.9 +/- 1.8 to 3.8 +/- 0.8 ng X ml-1 X 3 h-1 (P less than 0.01), respectively. ANG II infusion at 5.0 and 10.0 ng X kg-1 X min-1 decreased PRA from 7.5 +/- 2.3 to 2.5 +/- 0.7 (P less than 0.01) and from 6.0 +/- 1.1 to 1.8 +/- 0.4 ng X ml-1 X 3 h-1 (P less than 0.01), respectively. One to three weeks following renal denervation, PRA had decreased from 6.7 +/- 1.3 to 2.9 +/- 0.5 ng X ml-1 X 3 h-1 (P less than 0.01), and renal norepinephrine was undetectable. After denervation, neither AVP infusion at 0.2 (3.0 +/- 0.5 to 2.4 +/- 0.4 ng X ml-1 X 3 h-1) nor 1.0 ng X kg-1 X min-1 (3.1 +/- 0.8 to 2.8 +/- 1.0 ng X ml-1 X 3 h-1) suppressed PRA.(ABSTRACT TRUNCATED AT 250 WORDS)
- Published
- 1984
- Full Text
- View/download PDF
44. Effect of baroreceptor denervation on the inhibition of renin release by vasopressin.
- Author
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Gregory LC, Quillen EW Jr, Keil LC, and Reid IA
- Subjects
- Angiotensin II pharmacology, Animals, Blood Pressure drug effects, Dogs, Female, Heart Conduction System drug effects, Heart Rate drug effects, Male, Pressoreceptors drug effects, Reference Values, Renin antagonists & inhibitors, Renin blood, Arginine Vasopressin pharmacology, Denervation, Heart Conduction System physiology, Pressoreceptors physiology, Renin metabolism
- Abstract
Previous studies have suggested that the inhibition of renin secretion by acute administration of vasopressin in conscious dogs results from a reflex reduction in renal nerve activity. In the present investigation, this hypothesis was tested by studying the effect of total baroreceptor denervation or selective low pressure baroreceptor denervation on the suppression of PRA by vasopressin in conscious, chronically prepared dogs. In eight sham-operated dogs, a 45-min infusion of vasopressin (2.0 ng/kg.min, iv) decreased PRA from 10.5 +/- 1.9 to 5.9 +/- 1.0 ng/ml.3 h (P less than 0.01). Mean arterial pressure did not change (110 +/- 10 to 107 +/- 7 mm Hg), but heart rate decreased from 84 +/- 9 to 69 +/- 8 beats/min (P less than 0.05). In contrast, vasopressin infusion failed to significantly decrease PRA in seven sinoaortic/cardiac denervated dogs (9.5 +/- 1.7 to 7.4 +/- 2.0 ng/ml.3 h), although decreases did occur in three of the dogs. Mean arterial pressure increased from 104 +/- 5 to 125 +/- 6 mm Hg (P less than 0.01), but heart rate did not change (112 +/- 4 to 107 +/- 5 beats/min). When renal perfusion pressure was maintained at the preinfusion level in three sinoaortic/cardiac denervated dogs, vasopressin infusion failed to decrease PRA (2.3 +/- 0.6 to 2.4 +/- 0.6 ng/ml.3 h). In six cardiac denervated dogs, vasopressin infusion decreased PRA from 5.3 to 0.9 to 3.1 +/- 0.7 ng/ml.3 h (P less than 0.01). Results obtained with two lower doses of vasopressin (0.5 and 1.0 ng/kg.min) were generally similar to the responses observed during infusion at 2.0 ng/kg.min. Angiotensin II (5.0 ng/kg.min) suppressed PRA in all groups of dogs. These experiments demonstrate that the inhibition of renin secretion by acute administration of vasopressin in conscious dogs is prevented by total baroreceptor denervation, but not by denervation of the low pressure baroreceptors alone. These results suggest that the suppression of renin release by vasopressin is a reflex response resulting from activation of the high pressure baroreceptors.
- Published
- 1988
- Full Text
- View/download PDF
45. Effect of vasopressin blockade on blood pressure during water deprivation in intact and baroreceptor-denervated conscious dogs.
- Author
-
Gregory LC, Quillen EW Jr, Keil LC, Chang D, and Reid IA
- Subjects
- Animals, Arginine Vasopressin pharmacology, Dogs, Female, Heart Rate drug effects, Male, Nitroglycerin pharmacology, Phenylephrine pharmacology, Renin blood, Arginine Vasopressin analogs & derivatives, Blood Pressure drug effects, Pressoreceptors physiology, Vasopressins antagonists & inhibitors, Water Deprivation
- Abstract
Previous studies have provided evidence that vasopressin plays an important role in blood pressure regulation during water deprivation. However, these investigations have been complicated by reflex compensatory increases in cardiac output and renin secretion. The aim of the present study was to investigate the effect of blockade of the vasoconstrictor action of vasopressin in conscious water-deprived dogs in which the low- and/or high-pressure baroreceptors were denervated to minimize reflex responses. Vasopressin blockade in sham-operated dogs (n = 7) did not change arterial pressure. Heart rate rose from 78 +/- 9 to 119 +/- 13 beats/min (P less than 0.01), and plasma renin activity increased from 10.9 +/- 2.1 to 21.6 +/- 4.6 ng.ml-1.3 h-1 (P less than 0.01). In carotid sinus-denervated dogs (n = 6), vasopressin blockade again failed to decrease arterial pressure. Heart rate increased from 105 +/- 10 to 132 +/- 10 beats/min (P less than 0.01), and plasma renin activity rose from 6.8 +/- 1.7 to 15.5 +/- 2.4 ng.ml-1.3 h-1 (P less than 0.01). The antagonist also failed to change blood pressure in cardiac-denervated dogs (n = 5). Heart rate increased from 111 +/- 9 to 119 +/- 1 beats/min (P less than 0.01), but plasma renin activity did not increase significantly. In marked contrast, vasopressin blockade in sinoaortic/cardiac-denervated dogs (n = 7) promptly decreased arterial pressure from 115 +/- 8 to 94 +/- 7 mmHg (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
- Published
- 1988
- Full Text
- View/download PDF
46. Effect of subunit III removal on control of cytochrome c oxidase activity by pH.
- Author
-
Gregory LC and Ferguson-Miller S
- Subjects
- Animals, Cattle, Dicyclohexylcarbodiimide pharmacology, Hydrogen-Ion Concentration, Kinetics, Macromolecular Substances, Mitochondria, Heart enzymology, Electron Transport Complex IV metabolism
- Abstract
Studies were undertaken to assess the postulated involvement of subunit III in the proton-linked functions of cytochrome c oxidase. The effect of pH on the steady-state kinetic [corrected] parameters of subunit III containing and subunit III depleted cytochrome oxidase was determined by using beef heart and rat liver enzymes reconstituted into phospholipid vesicles. The TNmax and Km values for the III-containing enzyme increase with decreasing pH in a manner quantitatively similar to that reported by Thornstrom et al. [(1984) Chem. Scr. 24, 230-235], giving three apparent pKa values of less than 5.0, 6.2, and 7.8. The maximal activities of the subunit III depleted enzymes (beef heart and rat liver) show a similar dependence on pH, but the Km values are consistently higher than those of the III-containing enzyme, an effect that is accentuated at low pH. The pH dependence of TNmax/Km for both forms of the enzyme (+/- subunit III) indicates that protonation of a group with an apparent pKa of 5.7 lowers the affinity for substrate (cytochrome c) independently of a continued increase in maximal velocity. N,N'-Dicyclohexylcarbodiimide (DCCD) decreases the pH responsiveness of the electron-transfer activity to the same extent in both III-containing and III-depleted enzymes, indicating that this effect is mediated by a peptide other than subunit III. Control of intramolecular electron transfer by a transmembrane pH gradient (or alkaline intravesicular pH) is shown to occur in cytochrome oxidase vesicles with cytochrome c as the electron donor, in agreement with results of Moroney et al. [(1984) Biochemistry 23, 4991-4997] using hexaammineruthenium(II) as the reductant.(ABSTRACT TRUNCATED AT 250 WORDS)
- Published
- 1988
- Full Text
- View/download PDF
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