scholarly journals Hypothalamic and pituitary development: novel insights into the aetiology

2007 ◽  
Vol 157 (suppl_1) ◽  
pp. S3-S14 ◽  
Author(s):  
Daniel Kelberman ◽  
Mehul Tulsidas Dattani
Keyword(s):  
Transcription Factor ◽  
Transcription Factors ◽  
Cell Types ◽  
Hormone Deficiency ◽  
Pituitary Hormone ◽  
Gene Encoding ◽  
Complex Disorders ◽  
Signalling Molecules ◽  
Pituitary Development ◽  
Transgenic Murine Models

The anterior pituitary gland is a central regulator of growth, reproduction and homeostasis, and is the end-product of a carefully orchestrated pattern of expression of signalling molecules and transcription factors leading to the development of this complex organ secreting six hormones from five different cell types. Naturally occurring and transgenic murine models have demonstrated a role for many of these molecules in the aetiology of combined pituitary hormone deficiency (CPHD). These include the transcription factors HESX1, PROP1, POU1F1, LHX3, LHX4, TBX19, SOX2 and SOX3. The expression pattern of these transcription factors dictates the phenotype that results when the gene encoding the relevant transcription factor is mutated. The highly variable phenotype may consist of isolated hypopituitarism, or more complex disorders such as septo-optic dysplasia and holoprosencephaly. Since mutations in any one transcription factor are uncommon, and since the overall incidence of mutations in known transcription factors is low in patients with CPHD, it is clear that many genes remain to be identified, and the characterization of these will further elucidate the pathogenesis of these complex conditions and also shed light on normal pituitary development.

scholarly journals MECHANISMS IN ENDOCRINOLOGY: An update in the genetic aetiologies of combined pituitary hormone deficiency

2016 ◽  
Vol 174 (6) ◽  
pp. R239-R247 ◽  
Author(s):  
Frederic Castinetti ◽  
Rachel Reynaud ◽  
Alexandru Saveanu ◽  
Nicolas Jullien ◽  
Marie Helene Quentien ◽  
...  
Keyword(s):  
Transcription Factors ◽  
G Protein Coupled Receptors ◽  
Hormone Deficiency ◽  
Immunoglobulin Superfamily ◽  
Pituitary Hormone ◽  
Pituitary Hormone Deficiency ◽  
Combined Pituitary Hormone Deficiency ◽  
Signalling Molecules ◽  
Genes Encoding ◽  
G Protein Coupled

Over the last 5 years, new actors involved in the pathogenesis of combined pituitary hormone deficiency in humans have been reported: they included a member of the immunoglobulin superfamily glycoprotein and ciliary G protein-coupled receptors, as well as new transcription factors and signalling molecules. New modes of inheritance for alterations of genes encoding transcription factors have also been described. Finally, actors known to be involved in a very specific phenotype (hypogonadotroph hypogonadism for instance) have been identified in a wider range of phenotypes. These data thus suggest that new mechanisms could explain the low rate of aetiological identification in this heterogeneous group of diseases. Taking into account the fact that several reviews have been published in recent years on classical aetiologies of CPHD such as mutations ofPOU1F1orPROP1, we focused the present overview on the data published in the last 5 years, to provide the reader with an updated review on this rapidly evolving field of knowledge.

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 Genetikai tényezők a hypopituitarismus kialakulásában. A transzkripciós faktorok szerepe az agyalapimirigy-elégtelenség hátterében

2018 ◽  
Vol 159 (7) ◽  
pp. 278-284
Author(s):  
Judit Tőke ◽  
Rita Bertalan ◽  
Péter Gergics ◽  
Zita Halász
Keyword(s):  
Transcription Factor ◽  
Transcription Factors ◽  
Developmental Disorders ◽  
Late Phase ◽  
World Health ◽  
Hormone Deficiency ◽  
Pituitary Hormone ◽  
Pituitary Hormone Deficiency ◽  
Transcription Factor Genes ◽  
Essential Knowledge

Abstract: Developmental disorders affecting the hypothalamic-pituitary system can result in pituitary hormone deficiency showing a diverse clinical presentation. A significant majority of these disorders are closely linked to defects in transcription factor genes which play a major role in pituitary development. Those affecting the early phase of organogenesis typically lead to complex conditions affecting the pituitary as well as structures in the central nervous system. Transcription factors involved in the late phase can result in combined but rarely isolated pituitary hormone deficiency without extra-pituitary manifestation. Identifying the defects in these pituitary transcription factor genes may provide a useful tool in predicting disease progression as well as screening family members. Several pituitary transcription factors can be detected in the adult gland as well which is strongly emphasized in the World Health Organization’s most recent guideline for pituitary tumor classification. Our review summarizes the current essential knowledge relevant for clinical endocrinologists. Orv Hetil. 2018; 159(7): 278–284.

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.

scholarly journals HOT or not: examining the basis of high-occupancy target regions

2017 ◽  
Author(s):  
Katarzyna Wreczycka ◽  
Vedran Franke ◽  
Bora Uyar ◽  
Ricardo Wurmus ◽  
Altuna Akalin
Keyword(s):  
Transcription Factor ◽  
Transcription Factors ◽  
Binding Sites ◽  
Cell Types ◽  
Data Sets ◽  
Gene Promoters ◽  
Quadruplex Dna ◽  
Golden Standard ◽  
Multiple Cell ◽  
Multiple Species

AbstractHigh-occupancy target (HOT) regions are the segments of the genome with unusually high number of transcription factor binding sites. These regions are observed in multiple species and thought to have biological importance due to high transcription factor occupancy. Furthermore, they coincide with house-keeping gene promoters and the associated genes are stably expressed across multiple cell types. Despite these features, HOT regions are solemnly defined using ChIP-seq experiments and shown to lack canonical motifs for transcription factors that are thought to be bound there. Although, ChIP-seq experiments are the golden standard for finding genome-wide binding sites of a protein, they are not noise free. Here, we show that HOT regions are likely to be ChIP-seq artifacts and they are similar to previously proposed “hyper-ChIPable” regions. Using ChIP-seq data sets for knocked-out transcription factors, we demonstrate presence of false positive signals on HOT regions. We observe sequence characteristics and genomic features that are discriminatory of HOT regions, such as GC/CpG-rich k-mers and enrichment of RNA-DNA hybrids (R-loops) and DNA tertiary structures (G-quadruplex DNA). The artificial ChIP-seq enrichment on HOT regions could be associated to these discriminatory features. Furthermore, we propose strategies to deal with such artifacts for the future ChIP-seq studies.

scholarly journals Virtual ChIP-seq: predicting transcription factor binding by learning from the transcriptome

2018 ◽  
Author(s):  
Mehran Karimzadeh ◽  
Michael M. Hoffman
Keyword(s):  
Transcription Factor ◽  
Transcription Factors ◽  
Binding Sites ◽  
Cell Types ◽  
Transcription Factor Binding ◽  
Regulatory Function ◽  
Factor Binding ◽  
Link Type ◽  
Genomic Regions ◽  
Factor Sequence

AbstractMotivationIdentifying transcription factor binding sites is the first step in pinpointing non-coding mutations that disrupt the regulatory function of transcription factors and promote disease. ChIP-seq is the most common method for identifying binding sites, but performing it on patient samples is hampered by the amount of available biological material and the cost of the experiment. Existing methods for computational prediction of regulatory elements primarily predict binding in genomic regions with sequence similarity to known transcription factor sequence preferences. This has limited efficacy since most binding sites do not resemble known transcription factor sequence motifs, and many transcription factors are not even sequence-specific.ResultsWe developed Virtual ChIP-seq, which predicts binding of individual transcription factors in new cell types using an artificial neural network that integrates ChIP-seq results from other cell types and chromatin accessibility data in the new cell type. Virtual ChIP-seq also uses learned associations between gene expression and transcription factor binding at specific genomic regions. This approach outperforms methods that predict TF binding solely based on sequence preference, pre-dicting binding for 36 transcription factors (Matthews correlation coefficient > 0.3).AvailabilityThe datasets we used for training and validation are available at https://virchip.hoffmanlab.org. We have deposited in Zenodo the current version of our software (http://doi.org/10.5281/zenodo.1066928), datasets (http://doi.org/10.5281/zenodo.823297), predictions for 36 transcription factors on Roadmap Epigenomics cell types (http://doi.org/10.5281/zenodo.1455759), and predictions in Cistrome as well as ENCODE-DREAM in vivo TF Binding Site Prediction Challenge (http://doi.org/10.5281/zenodo.1209308).

scholarly journals An Algorithm for Cellular Reprogramming

2017 ◽  
Author(s):  
Scott Ronquist ◽  
Geoff Patterson ◽  
Markus Brown ◽  
Stephen Lindsly ◽  
Haiming Chen ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Transcription Factor ◽  
Transcription Factors ◽  
Cell Biology ◽  
Human Fibroblasts ◽  
Cell Types ◽  
Approximate Model ◽  
Cellular Reprogramming ◽  
Biological Processes ◽  
Moderate Complexity

AbstractThe day we understand the time evolution of subcellular elements at a level of detail comparable to physical systems governed by Newton’s laws of motion seems far away. Even so, quantitative approaches to cellular dynamics add to our understanding of cell biology, providing data-guided frameworks that allow us to develop better predictions about, and methods for, control over specific biological processes and system-wide cell behavior. In this paper, we describe an approach to optimizing the use of transcription factors (TFs) in the context of cellular reprogramming. We construct an approximate model for the natural evolution of a cell cycle synchronized population of human fibroblasts, based on data obtained by sampling the expression of 22,083 genes at several time points along the cell cycle. In order to arrive at a model of moderate complexity, we cluster gene expression based on the division of the genome into topologically associating domains (TADs) and then model the dynamics of the TAD expression levels. Based on this dynamical model and known bioinformatics, such as transcription factor binding sites (TFBS) and functions, we develop a methodology for identifying the top transcription factor candidates for a specific cellular reprogramming task. The approach used is based on a device commonly used in optimal control. Our data-guided methodology identifies a number of transcription factors previously validated for reprogramming and/or natural differentiation. Our findings highlight the immense potential of dynamical models, mathematics, and data-guided methodologies for improving strategies for control over biological processes.Significance StatementReprogramming the human genome toward any desirable state is within reach; application of select transcription factors drives cell types toward different lineages in many settings. We introduce the concept of data-guided control in building a universal algorithm for directly reprogramming any human cell type into any other type. Our algorithm is based on time series genome transcription and architecture data and known regulatory activities of transcription factors, with natural dimension reduction using genome architectural features. Our algorithm predicts known reprogramming factors, top candidates for new settings, and ideal timing for application of transcription factors. This framework can be used to develop strategies for tissue regeneration, cancer cell reprogramming, and control of dynamical systems beyond cell biology.

scholarly journals Evaluation of pituitary imaging in patients with PROP-1 gene mutation

Medicina ◽  
2009 ◽  
Vol 45 (9) ◽  
pp. 693 ◽  
Author(s):  
Natalija Tkačenko ◽  
Danutė Lašienė ◽  
Silvija Jakštienė ◽  
Algidas Basevičius ◽  
Rasa Verkauskienė
Keyword(s):  
Transcription Factor ◽  
Pituitary Gland ◽  
Gene Mutation ◽  
Anterior Pituitary ◽  
Hormone Deficiency ◽  
Pituitary Hormone ◽  
Imaging Studies ◽  
Pituitary Hyperplasia ◽  
Pituitary Hypoplasia ◽  
Genetically Determined

The most common genetically determined cause of multiple pituitary hormone deficiency is PROP-1 gene mutation. PROP-1 is a transcription factor involved in the development of pituitary gland and affects hormonal synthesis of anterior pituitary. The aim of our study was to evaluate radiological aspects of the pituitary region in patients with PROP-1 gene mutation. Pituitary imaging studies were performed in 12 patients with a confirmed PROP-1 gene mutation. Pituitary hyperplasia was found in 5 (42%) and pituitary hypoplasia in 4 (33%) patients. Changes in pituitary size were not associated with the type of PROP-1 gene mutation.

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