A mutation of the β-domain in POU1F1 causes pituitary deficiency due to dominant PIT-1β expression

2021 ◽  
Author(s):  
Shigeru Suzuki ◽  
Kumihiro Matsuo ◽  
Yoshiya Ito ◽  
Atsushi Kobayashi ◽  
Takahide Kokumai ◽  
...  
Keyword(s):  
Hormone Deficiency ◽  
Luciferase Reporter ◽  
Heterozygous Mutation ◽  
Pituitary Hormone ◽  
Pituitary Cells ◽  
Transactivation Domain ◽  
Exon 2 ◽  
Pituitary Development ◽  
Long Term Follow Up ◽  
Alternatively Spliced

Background: POU1F1 encodes both PIT-1α, which plays pivotal roles in pituitary development and GH, PRL and TSHB expression, and the alternatively spliced isoform PIT-1β, which contains an insertion of 26-amino acids (β-domain) in the transactivation domain of PIT-1α due to the use of an alternative splice acceptor at the end of the first intron. PIT-1β is expressed at much lower levels than PIT-1α and represses endogenous PIT-1α transcriptional activity. Although POU1F1 mutations lead to combined pituitary hormone deficiency (CPHD), no patients with β-domain mutations have been reported. Results: Here, we report that a three-generation family exhibited different degrees of CPHD, including growth hormone deficiency with intrafamilial variability of prolactin/TSH insufficiency and unexpected prolactinoma occurrence. The CPHD was due to a novel POU1F1 heterozygous variant (c.143-69T>G) in intron 1 of PIT-1α (RefSeq number NM_000306) or as c.152T>G (p.Ile51Ser) in exon 2 of PIT-1β (NM_001122757). Gene splicing experiments showed that this mutation yielded the PIT-1β transcript without other transcripts. Lymphocyte PIT-1β mRNA expression was significantly higher in the patients with the heterozygous mutation than a control. A luciferase reporter assay revealed that the PIT-1β-Ile51Ser mutant repressed PIT-1α and abolished transactivation capacity for the rat prolactin promoter in GH3 pituitary cells. Conclusions: We describe, for the first time, that PIT-1β mutation can cause CPHD through a novel genetic mechanism, such as PIT-1β overexpression, and that POU1F1 mutation might be associated with a prolactinoma. Analysis of new patients and long-term follow-up are needed to clarify the characteristics of PIT-1β mutations.

Lhx4 and Prop1 are required for cell survival and expansion of the pituitary primordia

Development ◽  
2002 ◽  
Vol 129 (18) ◽  
pp. 4229-4239 ◽  
Author(s):  
Lori T. Raetzman ◽  
Robert Ward ◽  
Sally A. Camper
Keyword(s):  
Cell Survival ◽  
Anterior Pituitary ◽  
Molecular Genetic ◽  
Cell Types ◽  
Hormone Deficiency ◽  
Pituitary Hormone ◽  
Pituitary Cells ◽  
Temporal Shift ◽  
Pituitary Development ◽  
Show Evidence

Deficiencies in the homeobox transcription factors LHX4 and PROP1 cause pituitary hormone deficiency in both humans and mice. Lhx4 and Prop1 mutants exhibit severe anterior pituitary hypoplasia resulting from limited differentiation and expansion of most specialized cell types. Little is known about the mechanism through which these genes promote pituitary development. In this study we determined that the hypoplasia in Lhx4 mutants results from increased cell death and that the reduced differentiation is attributable to a temporal shift in Lhx3 activation. In contrast, Prop1 mutants exhibit normal cell proliferation and cell survival but show evidence of defective dorsal-ventral patterning. Molecular genetic analyses reveal that Lhx4 and Prop1 have overlapping functions in early pituitary development. Double mutants exhibit delayed corticotrope specification and complete failure of all other anterior pituitary cell types to differentiate. Thus, Lhx4 and Prop1 have critical, but mechanistically different roles in specification and expansion of specialized anterior pituitary cells.

scholarly journals Auxological and endocrine phenotype in a population-based cohort of patients with PROP1 gene defects

2005 ◽  
Vol 153 (3) ◽  
pp. 389-396 ◽  
Author(s):  
Jan Lebl ◽  
Jan Vosáhlo ◽  
Roland W Pfaeffle ◽  
Heike Stobbe ◽  
Jana Černá ◽  
...  
Keyword(s):  
Genomic Analysis ◽  
Population Based ◽  
Hormone Deficiency ◽  
Heterozygous Mutation ◽  
Pituitary Hormone ◽  
Phenotypic Analysis ◽  
Phenotypic Data ◽  
Sibling Pairs ◽  
Pituitary Development ◽  
Gene Defects

Objective: Multiple pituitary hormone deficiency (MPHD) may result from defects of transcription factors that govern early pituitary development. We aimed to establish the prevalence of HESX1, PROP1, and POU1F1 gene defects in a population-based cohort of patients with MPHD and to analyse the phenotype of affected individuals. Design and methods: Genomic analysis was carried out on 74 children and adults with MPHD from the Czech Republic (including four sibling pairs). Phenotypic data were collected from medical records and referring physicians. Results: One patient carried a heterozygous mutation of POU1F1 (71C > T), and 18 patients (including three sibling pairs) had a PROP1 mutation (genotypes 150delA/301delGA/9/, 301delGA/301-delGA/8/, or 301delGA/349T > A/1/). A detailed longitudinal phenotypic analysis was performed for patients with PROP1 mutations (n = 17). The mean ( ±s.d.) birth length SDS of these patients (0.12 ± 0.76) was lower than expected based on their mean ( ±s.d.) birth weight SDS (0.63 ± 1.27; P = 0.01). Parental heights were normal. The patients’ mean ( ±s.d.) height SDS declined to −1.5 ± 0.9, −3.6 ± 1.3 and −4.1 ± 1.2 at 1.5, 3 and 5 years of age, respectively. GH therapy, initiated at 6.8 ± 3.2 years of age (mean dose: 0.022 mg/kg per day), led to substantial growth acceleration in all patients. Mean adult height (n = 7) was normal when adjusted for mid-parental height. ACTH deficiency developed in two out of seven young adult patients. Conclusions: PROP1 defects are a prevalent cause of MPHD. We suggest that testing for PROP1 mutations in patients with MPHD might become standard practice in order to predict risk of additional pituitary hormone deficiencies.

scholarly journals PROP1 Gene Screening in Patients with Multiple Pituitary Hormone Deficiency Reveals Two Sites of Hypermutability and a High Incidence of Corticotroph Deficiency

2001 ◽  
Vol 86 (9) ◽  
pp. 4529-4535 ◽  
Author(s):  
S. Vallette-Kasic ◽  
A. Barlier ◽  
C. Teinturier ◽  
A. Diaz ◽  
M. Manavela ◽  
...  
Keyword(s):  
Point Mutations ◽  
Hormone Deficiency ◽  
Heterozygous Mutation ◽  
Pituitary Hormone ◽  
Gene Encoding ◽  
Exon 2 ◽  
High Incidence ◽  
Prop1 Gene ◽  
Gene Alterations

Alterations of the gene encoding the pituitary transcription factor PROP1 were associated with congenital forms of multiple pituitary hormone deficiencies in several families. Among 23 patients with multiple pituitary hormone deficiencies screened for a PROP1 gene abnormality, nine belonging to eight unrelated families had homozygous PROP1 gene defects. All mutations were located in exon 2 and affected only two different sites: a homozygous AG deletion at codons 99/100/101 (n = 5); homozygous point mutations affecting codon 73: R73C (n = 2) or R73H (n = 1), and a R73C/R99X double-heterozygous mutation (n= 1). R73H and R99X were never described. All patients were born to unaffected parents, and consanguinity was documented in two patients. They had complete GH, LH-FSH, and TSH deficiencies and normal basal levels of PRL. Delayed ACTH deficiency was diagnosed in four of nine patients. At magnetic resonance imaging the anterior pituitary was hypoplastic in seven patients and hyperplastic in two. This study found two novel mutations (R73H and R99X) and underlines the high incidence of PROP1 gene alterations in patients with multiple pituitary hormone deficiencies. A corticotroph deficiency was frequently observed in association with GH, TSH, and gonadotropin deficiencies and should be carefully sought during follow-up.

scholarly journals Dynamic Interactions between Pit-1 and C/EBPα in the Pituitary Cell Nucleus

2006 ◽  
Vol 26 (21) ◽  
pp. 8087-8098 ◽  
Author(s):  
Ignacio A. Demarco ◽  
Ty C. Voss ◽  
Cynthia F. Booker ◽  
Richard N. Day
Keyword(s):  
Transcriptional Control ◽  
Point Mutations ◽  
Binding Activity ◽  
Hormone Deficiency ◽  
Pituitary Hormone ◽  
Pituitary Cells ◽  
Dynamic Interactions ◽  
Dna Binding Activity ◽  
Control Patterns ◽  
Α Helix

ABSTRACT The homeodomain (HD) transcription factors are a structurally conserved family of proteins that, through networks of interactions with other nuclear proteins, control patterns of gene expression during development. For example, the network interactions of the pituitary-specific HD protein Pit-1 control the development of anterior pituitary cells and regulate the expression of the hormone products in the adult cells. Inactivating mutations in Pit-1 disrupt these processes, giving rise to the syndrome of combined pituitary hormone deficiency. Pit-1 interacts with CCAAT/enhancer-binding protein alpha (C/EBPα) to regulate prolactin transcription. Here, we used the combination of biochemical analysis and live-cell microscopy to show that two different point mutations in Pit-1, which disrupted distinct activities, affected the dynamic interactions between Pit-1 and C/EBPα in different ways. The results showed that the first α-helix of the POU-S domain is critical for the assembly of Pit-1 with C/EBPα, and they showed that DNA-binding activity conferred by the HD is critical for the final intranuclear positioning of the metastable complex. This likely reflects more general mechanisms that govern cell-type-specific transcriptional control, and the results from the analysis of the point mutations could indicate an important link between the mislocalization of transcriptional complexes and disease processes.

scholarly journals A PIT-1 Homeodomain Mutant Blocks the Intranuclear Recruitment Of the CCAAT/Enhancer Binding Protein α Required for Prolactin Gene Transcription

2003 ◽  
Vol 17 (2) ◽  
pp. 209-222 ◽  
Author(s):  
John F. Enwright ◽  
Margaret A. Kawecki-Crook ◽  
Ty C. Voss ◽  
Fred Schaufele ◽  
Richard N. Day
Keyword(s):  
Gene Transcription ◽  
Binding Protein ◽  
Hormone Deficiency ◽  
Centromeric Heterochromatin ◽  
Pituitary Hormone ◽  
Homeodomain Protein ◽  
Pituitary Cells ◽  
Enhancer Binding Protein ◽  
Ccaat Enhancer Binding Protein ◽  
Prl Gene

Abstract The pituitary-specific homeodomain protein Pit-1 cooperates with other transcription factors, including CCAAT/enhancer binding protein α (C/EBPα), in the regulation of pituitary lactotrope gene transcription. Here, we correlate cooperative activation of prolactin (PRL) gene transcription by Pit-1 and C/EBPα with changes in the subnuclear localization of these factors in living pituitary cells. Transiently expressed C/EBPα induced PRL gene transcription in pituitary GHFT1–5 cells, whereas the coexpression of Pit-1 and C/EBPα in HeLa cells demonstrated their cooperativity at the PRL promoter. Individually expressed Pit-1 or C/EBPα, fused to color variants of fluorescent proteins, occupied different subnuclear compartments in living pituitary cells. When coexpressed, Pit-1 recruited C/EBPα from regions of transcriptionally quiescent centromeric heterochromatin to the nuclear regions occupied by Pit-1. The homeodomain region of Pit-1 was necessary for the recruitment of C/EBPα. A point mutation in the Pit-1 homeodomain associated with the syndrome of combined pituitary hormone deficiency in humans also failed to recruit C/EBPα. This Pit-1 mutant functioned as a dominant inhibitor of PRL gene transcription and, instead of recruiting C/EBPα, was itself recruited by C/EBPα to centromeric heterochromatin. Together our results suggest that the intranuclear positioning of these factors determines whether they activate or silence PRL promoter activity.

scholarly journals Signal Transduction Mechanisms for Glucagon-Induced Somatolactin Secretion and Gene Expression in Nile Tilapia (Oreochromis niloticus) Pituitary Cells

2021 ◽  
Vol 11 ◽  
Author(s):  
Chaoyi Zhang ◽  
Anji Lian ◽  
Yue Xu ◽  
Quan Jiang
Keyword(s):  
Gene Expression ◽  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Primary Cultures ◽  
Hormone Secretion ◽  
Hek293 Cells ◽  
Luciferase Reporter ◽  
Pituitary Hormone ◽  
Pituitary Cells ◽  
Mrna Levels

Glucagon (GCG) plays a stimulatory role in pituitary hormone regulation, although previous studies have not defined the molecular mechanism whereby GCG affects pituitary hormone secretion. To this end, we identified two distinct proglucagons, Gcga and Gcgb, as well as GCG receptors, Gcgra and Gcgrb, in Nile tilapia (Oreochromis niloticus). Using the cAMP response element (CRE)-luciferase reporter system, tilapia GCGa and GCGb could reciprocally activate the two GCG receptors expressed in human embryonic kidney 293 (HEK293) cells. Quantitative real-time PCR analysis revealed that differential expression of the Gcga and Gcgb and their cognate receptors Gcgra and Gcgrb was found in the various tissues of tilapia. In particular, the Gcgrb is abundantly expressed in the neurointermediate lobe (NIL) of the pituitary gland. In primary cultures of tilapia NIL cells, GCGb effectively stimulated SL release, with parallel rises in the mRNA levels, and co-incubation with the GCG antagonist prevented GCGb-stimulated SL release. In parallel experiments, GCGb treatment dose-dependently enhanced intracellular cyclic adenosine monophosphate (cAMP) accumulation with increasing inositol 1,4,5-trisphosphate (IP3) concentration and the resulting in transient increases of Ca2+ signals in the primary NIL cell culture. Using selective pharmacological approaches, the adenylyl cyclase (AC)/cAMP/protein kinase A (PKA) and phospholipase C (PLC)/IP3/Ca2+/calmodulin (CaM)/CaMK-II pathways were shown to be involved in GCGb-induced SL release and mRNA expression. Together, these results provide evidence for the first time that GCGb can act at the pituitary level to stimulate SL release and gene expression via GCGRb through the activation of the AC/cAMP/PKA and PLC/IP3/Ca2+/CaM/CaMK-II cascades.

scholarly journals The PROP1 2-Base Pair Deletion Is a Common Cause of Combined Pituitary Hormone Deficiency1

1998 ◽  
Vol 83 (9) ◽  
pp. 3346-3349 ◽  
Author(s):  
Joy D. Cogan ◽  
Wei Wu ◽  
John A. Phillips ◽  
Ivo J. P. Arnhold ◽  
Ana Agapito ◽  
...  
Keyword(s):  
Human Subjects ◽  
Polymorphic Marker ◽  
Hormone Deficiency ◽  
Pituitary Hormone ◽  
Degree Relative ◽  
Exon 2 ◽  
Base Pair Deletion ◽  
Stimulation Tests ◽  
Sporadic Cases ◽  
Prop1 Gene

Combined pituitary hormone deficiency (CPHD) has an incidence of approximately 1 in 8000 births. Although the proportion of familial CPHD cases is unknown, about 10% have an affected first degree relative. We have recently reported three mutations in the PROP1 gene that cause CPHD in human subjects. We report here the frequency of one of these mutations, a 301–302delAG deletion in exon 2 of PROP1, in 10 independently ascertained CPHD kindreds and 21 sporadic cases of CPHD from 8 different countries. Our results show that 55% (11 of 20) of PROP1 alleles have the 301–302delAG deletion in familial CPHD cases. Interestingly, although only 12% (5 of 42) of the PROP1 alleles of our 21 sporadic cases were 301–302delAG, the frequency of this allele (in 20 of 21 of the sporadic subjects given TRH stimulation tests) was 50% (3 of 6) and 0% (0 of 34) in the CPHD cases with pituitary and hypothalamic defects, respectively. Using whole genome radiation hybrid analysis, we localized the PROP1 gene to the distal end of chromosome 5q and identified a tightly linked polymorphic marker, D5S408, which can be used in segregation studies. Analysis of this marker in affected subjects with the 301–302delAG deletion suggests that rather than being inherited from a common founder, the 301–302delAG may be a recurring mutation.

scholarly journals A Novel LHX3 Mutation Presenting as Combined Pituitary Hormonal Deficiency

2006 ◽  
Vol 91 (3) ◽  
pp. 747-753 ◽  
Author(s):  
Amrit P. S. Bhangoo ◽  
Chad S. Hunter ◽  
Jesse J. Savage ◽  
Henry Anhalt ◽  
Steven Pavlakis ◽  
...  
Keyword(s):  
Cervical Spine ◽  
Novel Mutation ◽  
Laboratory Data ◽  
Nervous System Development ◽  
In Vitro Translation ◽  
Hormone Deficiency ◽  
Pituitary Hormone ◽  
Free T4 ◽  
Exon 2 ◽  
Base Pair Deletion

Abstract Context: LHX3 encodes LIM homeodomain class transcription factors with important roles in pituitary and nervous system development. The only previous report of LHX3 mutations described patients with two types of recessive mutations displaying combined pituitary hormone deficiency coupled with neck rigidity. Objective: We report a patient presenting a unique phenotype associated with a novel mutation in the LHX3 gene. Patient: We report a 6-yr, 9-month-old boy born from a consanguineous relationship who presented shortly after birth with cyanosis, feeding difficulty, persistent jaundice, micropenis, and poor weight gain and growth rate. Laboratory data, including an undetectable TSH, low free T4, low IGF-I and IGF binding protein-3, prolactin deficiency, and LH and FSH deficiency were consistent with hypopituitarism. A rigid cervical spine leading to limited head rotation was noticed on follow-up examination. Magnetic resonance imaging revealed an apparently structurally normal cervical spine and a postcontrast hypointense lesion in the anterior pituitary. Results: Analysis of the LHX3 gene revealed homozygosity for a novel single-base-pair deletion in exon 2. This mutation leads to a frame shift predicted to result in the production of short, inactive LHX3 proteins. The results of in vitro translation experiments are consistent with this prediction. The parents of the patients are heterozygotes, indicating a recessive mode of action for the deletion allele. Conclusions: The presence of a hypointense pituitary lesion and other clinical findings broadens the phenotype associated with LHX3 gene mutation.

scholarly journals Functional SNPs within the Intron 1 of the PROP1 Gene Contribute to Combined Growth Hormone Deficiency (CPHD)

2012 ◽  
Vol 97 (9) ◽  
pp. E1791-E1797 ◽  
Author(s):  
Michela Godi ◽  
Simona Mellone ◽  
Luigi Tiradani ◽  
Rita Marabese ◽  
Claudio Bardelli ◽  
...  
Keyword(s):  
Regulatory Element ◽  
Hormone Deficiency ◽  
Luciferase Reporter ◽  
Pituitary Hormone ◽  
Mcf7 Cells ◽  
Luciferase Reporter Gene ◽  
Risk Alleles ◽  
Intron 1 ◽  
Sporadic Cases ◽  
Prop1 Gene

Context: Mutations within the PROP1 gene represent one of the main causes of familial combined pituitary hormone deficiency (CPHD). However, most of the cases are sporadic with an unknown genetic cause. Objective: The aim of this study was the search for low penetrance variations within and around a conserved regulatory element in the intron 1 of PROP1, contributing to a multifactorial form of the disease in sporadic patients. Methods and Patients: A fragment of 570 bp encompassing the conserved region was sequenced in 107 CPHD patients and 294 controls, and an association study was performed with the four identified variants, namely c.109+435G>A (rs73346254), c.109+463C>T (rs4498267), c.109+768C>G (rs4431364), and c.109+915_917ins/delTAG (rs148607624). The functional role of the associated polymorphisms was evaluated by luciferase reporter gene expression analyses and EMSA. Results: A statistically significant increased frequency was observed in the patients for rs73346254A (P = 5 × 10−4) and rs148607624delTAG (P = 0.01) alleles. Among all the possible allele combinations, only the haplotype bearing both risk alleles showed a significantly higher frequency in the patients vs. controls (P = 4.7 × 10−4) and conferred a carrier risk of 4.19 (P = 1.2 × 10−4). This haplotype determined a significant decrease of the luciferase activity in comparison with a basal promoter and the other allelic combinations in GH4C and MCF7 cells (P = 4.6 × 10−6; P = 5.5 × 10−4, respectively). The EMSA showed a differential affinity for nuclear proteins for the alternative alleles of the two associated variations. Conclusions: Variations with a functional significance conferring susceptibility to CPHD have been identified in the PROP1 gene, indicating a multifactorial origin of this disorder in sporadic cases.

scholarly journals Heterozygous defects in PAX6 gene and congenital hypopituitarism

2015 ◽  
Vol 172 (1) ◽  
pp. 37-45 ◽  
Author(s):  
Masaki Takagi ◽  
Keisuke Nagasaki ◽  
Ikuma Fujiwara ◽  
Tomohiro Ishii ◽  
Naoko Amano ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
De Novo ◽  
Chromosomal Rearrangements ◽  
Copy Number Variations ◽  
Hormone Deficiency ◽  
Comparative Genomic ◽  
Pituitary Hormone ◽  
Pax6 Gene ◽  
Pituitary Development ◽  
Congenital Hypopituitarism

BackgroundThe prevalence of congenital hypopituitarism (CH) attributable to known transcription factor mutations appears to be rare and other causative genes for CH remain to be identified. Due to the sporadic occurrence of CH, de novo chromosomal rearrangements could be one of the molecular mechanisms participating in its etiology, especially in syndromic cases.ObjectiveTo identify the role of copy number variations (CNVs) in the etiology of CH and to identify novel genes implicated in CH.Subjects and methodsWe enrolled 88 (syndromic: 30; non-syndromic: 58) Japanese CH patients. We performed an array comparative genomic hybridization screening in the 30 syndromic CH patients. For all the 88 patients, we analyzed PAX6 by PCR-based sequencing.ResultsWe identified one heterozygous 310-kb deletion of the PAX6 enhancer region in one patient showing isolated GH deficiency (IGHD), cleft palate, and optic disc cupping. We also identified one heterozygous 6.5-Mb deletion encompassing OTX2 in a patient with bilateral anophthalmia and multiple pituitary hormone deficiency. We identified a novel PAX6 mutation, namely p.N116S in one non-syndromic CH patient showing IGHD. The p.N116S PAX6 was associated with an impairment of the transactivation capacities of the PAX6-binding elements.ConclusionsThis study showed that heterozygous PAX6 mutations are associated with CH patients. PAX6 mutations may be associated with diverse clinical features ranging from severely impaired ocular and pituitary development to apparently normal phenotype. Overall, this study identified causative CNVs with a possible role in the etiology of CH in <10% of syndromic CH patients.

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