scholarly journals NeuroD Expression in Podocytes and Interrelationships with Nephrin at Both Nuclear and Cytoplasmic Sites

2018 ◽  
Vol 46 (3) ◽  
pp. 873-889 ◽  
Author(s):  
Silvia Armelloni ◽  
Masami Ikehata ◽  
Deborah Mattinzoli ◽  
Min Li ◽  
Carlo Maria Alfieri ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Cell Fate ◽  
Promoter Region ◽  
Cell Shape ◽  
Chip Assay ◽  
Glomerular Function ◽  
Functional Roles ◽  
The Central Nervous System ◽  
Object Of Study ◽  
System Differentiation

Background/Aims The research of genes implicated in kidney glomerular function, eliciting cell fate program, is always at the forefront in nephrological studies. Several neurological molecules have been recently the object of study not only for their involvement in the central nervous system differentiation but also for their importance in the functionality of other organs and for mature phenotype, as in kidney. NeuroD, in CNS, is related to two functional roles, the early survival and the differentiation. The aim of our study was to ascertain the presence of NeuroD transcription factor in glomeruli and to understand which targets and mechanisms NeuroD controls. Methods: We used immunofluorescence (IF) studies on both human and mice renal tissues and on cultured podocytes to describe NeuroD distribution; then we investigated NeuroD binding to the nephrin promoter region in cultured podocytes by chromatin-immuno-precipitation (ChIP) assay. The overexpression of NeuroD in podocytes was used to establish first its role in nephrin synthesis, evaluated by real-time quantitative (RTq) PCR and western-blot (WB) and successively to determine the recovery of cell morphology after adriamycin injury, measuring foot processes length. Results: We identified NeuroD transcription factor in glomeruli, in the same cells positive for WT1 and synaptopodin, namely podocytes; subsequently we observed a differentiation dependent NeuroD distribution in cultured podocytes, and a consistent link of NeuroD with the Nephrin promoter leading to the regulation of Nephrin translation and transcription. Our data also describes NeuroD expression in cytoplasm as phosphoprotein linked to nephrin and actinin4. Preliminary experiments seem to indicate NeuroD involved in dynamics of cell shape regulation after adriamycin injury. Conclusion: we propose that NeuroD possess in podocytes a dual ability acting in the nucleus as a transcription factor and in cytoplasm stabilizing cell shape.

Mechanism of Platelet Factor (PF4) Deficiency with RUNX1 Mutations: RUNX1 Is a Transcriptional Regulator of PF4.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 227-227 ◽  
Author(s):  
Kawalpreet Aneja ◽  
Gauthami S Jalagadugula ◽  
Guangfen Mao ◽  
A. Koneti Rao
Keyword(s):  
Transcription Factor ◽  
Promoter Region ◽  
Luciferase Activity ◽  
Allelic Variant ◽  
Upstream Region ◽  
Chip Assay ◽  
Platelet Factor ◽  
Hel Cells ◽  
Gray Platelet Syndrome

Abstract Abstract 227 RUNX1/CBFA2 (Core binding factor A2) is a major transcription factor involved in hematopoiesis. RUNX1 mutations are associated with mild thrombocytopenia, platelet dysfunction, and predisposition to acute leukemia. Several patients with mutations in RUNX1 have been shown to have alpha granule deficiency characterized by decreased platelet factor 4 (PF4) content. The mechanisms leading to PF4 deficiency remain unclear in most patients with α-granule abnormalities or the Gray platelet Syndrome (GPS). GPS is a heterogeneous disorder, and defective granule formation and targeting of proteins to the granule have been postulated. Previous studies from our group have documented a patient with mild thrombocytopenia, impaired platelet aggregation, secretion, phosphorylation of pleckstrin and myosin light chain (MLC), and GPIIb-IIIa activation, which was associated with a heterozygous mutation in transcription factor RUNX1. Platelet expression profiling of this patient showed decreased expression of several genes including chemokine PF4 and its non-allelic variant PF4V1. Platelet PF4 protein was also decreased. PF4 is mainly expressed in megakaryocytes and platelets, and it serves as a lineage-specific marker of megakaryocytic differentiation. Because PF4 is downregulated in platelets from our patient with a RUNX1 mutation, we addressed the hypothesis that PF4 and PF4V1 may be direct transcriptional targets of RUNX1. Computer based TFSEARCH analysis showed six RUNX1 consensus sites on PF4 upstream (2 kb) region and eleven RUNX1 sites on PF4V1 upstream sequence (2 kb). To assess in vivo binding of RUNX1 to PF4 upstream region chromatin immunoprecipitation (ChIP) assay was performed using HEL cell genomic DNA and RUNX1 antibody. These studies were done in HEL cells treated with phorbol 12-myristate 13-acetate (PMA) to induce megakaryocytic transformation. ChIP assay revealed in vivo RUNX1 binding in two regions encompassing RUNX1 sites at −1768 (TGTGGT) and −151 (ACCGCA) on PF4 promoter. These sites were pursued with electrophoretic mobility shift assay (EMSA) using PMA treated HEL cell nuclear extract. EMSA showed specific protein binding to DNA probes encompassing each of the above sites; this was abolished by RUNX1 antibody. The ChIP and EMSA suggest that RUNX1 binds to the PF4 promoter region. To test the functional relevance of the RUNX1 binding sites wild type PF4 upstream promoter region (−1936/−27) containing both RUNX1 sites (−1768, and −151) or containing one or both sites mutated were cloned into firefly luciferase reporter gene vector pGL4 and expressed in PMA-treated HEL cells. Mutation of the −1768 site caused ∼50% reduction in luciferase activity, mutation at −151 site caused 60% reduction in activity and mutation of both sites caused 75-80% reduction in activity. These studies suggest that each RUNX1 site contributes to the transcriptional activity of PF4 promoter. Moreover, the upstream region (−1837 to +25) of the non-allelic variant PF4V1 was cloned into pGL4 plasmid; it showed negligible luciferase activity as compared to the wild PF4 promoter containing plasmid. These studies suggest that the regulation of PF4 and its variant PF4V1 is distinctly different in HEL cells. Conclusions: Our results provide the first evidence that PF4 promoter is regulated by RUNX1, and the two RUNX1 sites at −1768 and −151 are involved in its regulation. These studies provide a cogent explanation for the α-granule PF4 deficiency in our patient and others with RUNX1/CBFA2 haplodeficiency. They extend our understanding of the potential mechanisms involved in the pathogenesis of the Gray platelet syndrome. Disclosures: No relevant conflicts of interest to declare.

scholarly journals The EGL-13 SOX Domain Transcription Factor Affects the Uterine Cell Lineages in Caenorhabditis elegans

Genetics ◽  
2003 ◽  
Vol 165 (3) ◽  
pp. 1623-1628
Author(s):  
Hediye Nese Cinar ◽  
Keri L Richards ◽  
Kavita S Oommen ◽  
Anna P Newman
Keyword(s):  
Transcription Factor ◽  
Cell Division ◽  
Caenorhabditis Elegans ◽  
Cell Fate ◽  
Cell Lineages

Abstract We isolated egl-13 mutants in which the cells of the Caenorhabditis elegans uterus initially appeared to develop normally but then underwent an extra round of cell division. The data suggest that egl-13 is required for maintenance of the cell fate.

scholarly journals NEUROD1 Is Required for the Early α and β Endocrine Differentiation in the Pancreas

2021 ◽  
Vol 22 (13) ◽  
pp. 6713
Author(s):  
Romana Bohuslavova ◽  
Ondrej Smolik ◽  
Jessica Malfatti ◽  
Zuzana Berkova ◽  
Zaneta Novakova ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Cell Fate ◽  
Cell Mass ◽  
Neonatal Diabetes ◽  
Diabetes Research ◽  
Pancreas Development ◽  
Β Cells ◽  
Β Cell ◽  
Pancreatic Islet Cell ◽  
Endocrine Differentiation

Diabetes is a metabolic disease that involves the death or dysfunction of the insulin-secreting β cells in the pancreas. Consequently, most diabetes research is aimed at understanding the molecular and cellular bases of pancreatic development, islet formation, β-cell survival, and insulin secretion. Complex interactions of signaling pathways and transcription factor networks regulate the specification, growth, and differentiation of cell types in the developing pancreas. Many of the same regulators continue to modulate gene expression and cell fate of the adult pancreas. The transcription factor NEUROD1 is essential for the maturation of β cells and the expansion of the pancreatic islet cell mass. Mutations of the Neurod1 gene cause diabetes in humans and mice. However, the different aspects of the requirement of NEUROD1 for pancreas development are not fully understood. In this study, we investigated the role of NEUROD1 during the primary and secondary transitions of mouse pancreas development. We determined that the elimination of Neurod1 impairs the expression of key transcription factors for α- and β-cell differentiation, β-cell proliferation, insulin production, and islets of Langerhans formation. These findings demonstrate that the Neurod1 deletion altered the properties of α and β endocrine cells, resulting in severe neonatal diabetes, and thus, NEUROD1 is required for proper activation of the transcriptional network and differentiation of functional α and β cells.

scholarly journals Linking metabolic dysfunction with cardiovascular diseases: Brn-3b/POU4F2 transcription factor in cardiometabolic tissues in health and disease

2021 ◽  
Vol 12 (3) ◽  
Author(s):  
Vishwanie S. Budhram-Mahadeo ◽  
Matthew R. Solomons ◽  
Eeshan A. O. Mahadeo-Heads
Keyword(s):  
Transcription Factor ◽  
Cardiovascular Diseases ◽  
Cell Fate ◽  
Target Genes ◽  
Cardiovascular Responses ◽  
Normal Function ◽  
Valuable Insight ◽  
Metabolic Dysfunction ◽  
Pathological Changes ◽  
Cardiac Responses

AbstractMetabolic and cardiovascular diseases are highly prevalent and chronic conditions that are closely linked by complex molecular and pathological changes. Such adverse effects often arise from changes in the expression of genes that control essential cellular functions, but the factors that drive such effects are not fully understood. Since tissue-specific transcription factors control the expression of multiple genes, which affect cell fate under different conditions, then identifying such regulators can provide valuable insight into the molecular basis of such diseases. This review explores emerging evidence that supports novel and important roles for the POU4F2/Brn-3b transcription factor (TF) in controlling cellular genes that regulate cardiometabolic function. Brn-3b is expressed in insulin-responsive metabolic tissues (e.g. skeletal muscle and adipose tissue) and is important for normal function because constitutive Brn-3b-knockout (KO) mice develop profound metabolic dysfunction (hyperglycaemia; insulin resistance). Brn-3b is highly expressed in the developing hearts, with lower levels in adult hearts. However, Brn-3b is re-expressed in adult cardiomyocytes following haemodynamic stress or injury and is necessary for adaptive cardiac responses, particularly in male hearts, because male Brn-3b KO mice develop adverse remodelling and reduced cardiac function. As a TF, Brn-3b regulates the expression of multiple target genes, including GLUT4, GSK3β, sonic hedgehog (SHH), cyclin D1 and CDK4, which have known functions in controlling metabolic processes but also participate in cardiac responses to stress or injury. Therefore, loss of Brn-3b and the resultant alterations in the expression of such genes could potentially provide the link between metabolic dysfunctions with adverse cardiovascular responses, which is seen in Brn-3b KO mutants. Since the loss of Brn-3b is associated with obesity, type II diabetes (T2DM) and altered cardiac responses to stress, this regulator may provide a new and important link for understanding how pathological changes arise in such endemic diseases.

scholarly journals Syntaxin 1A Gene Is Negatively Regulated in a Cell/Tissue Specific Manner by YY1 Transcription Factor, Which Binds to the −183 to −137 Promoter Region Together with Gene Silencing Factors Including Histone Deacetylase

Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 146
Author(s):  
Takahiro Nakayama ◽  
Toshiyuki Fukutomi ◽  
Yasuo Terao ◽  
Kimio Akagawa
Keyword(s):  
Transcription Factor ◽  
Gene Silencing ◽  
Protein Complex ◽  
Promoter Region ◽  
Neuronal Cell ◽  
Syntaxin 1A ◽  
Tissue Specific ◽  
Cell Tissue ◽  
Specific Manner ◽  
A Cell

The HPC-1/syntaxin 1A (Stx1a) gene, which is involved in synaptic transmission and neurodevelopmental disorders, is a TATA-less gene with several transcription start sites. It is activated by the binding of Sp1 and acetylated histone H3 to the −204 to +2 core promoter region (CPR) in neuronal cell/tissue. Furthermore, it is depressed by the association of class 1 histone deacetylases (HDACs) to Stx1a–CPR in non-neuronal cell/tissue. To further clarify the factors characterizing Stx1a gene silencing in non-neuronal cell/tissue not expressing Stx1a, we attempted to identify the promoter region forming DNA–protein complex only in non-neuronal cells. Electrophoresis mobility shift assays (EMSA) demonstrated that the −183 to −137 OL2 promoter region forms DNA–protein complex only in non-neuronal fetal rat skin keratinocyte (FRSK) cells which do not express Stx1a. Furthermore, the Yin-Yang 1 (YY1) transcription factor binds to the −183 to −137 promoter region of Stx1a in FRSK cells, as shown by competitive EMSA and supershift assay. Chromatin immunoprecipitation assay revealed that YY1 in vivo associates to Stx1a–CPR in cell/tissue not expressing Stx1a and that trichostatin A treatment in FRSK cells decreases the high-level association of YY1 to Stx1a-CPR in default. Reporter assay indicated that YY1 negatively regulates Stx1a transcription. Finally, mass spectrometry analysis showed that gene silencing factors, including HDAC1, associate onto the −183 to −137 promoter region together with YY1. The current study is the first to report that Stx1a transcription is negatively regulated in a cell/tissue-specific manner by YY1 transcription factor, which binds to the −183 to −137 promoter region together with gene silencing factors, including HDAC.

scholarly journals Histone demethylase JMJD2B/KDM4B regulates transcriptional program via distinctive epigenetic targets and protein interactors for the maintenance of trophoblast stem cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kylie Hin-Man Mak ◽  
Yuk Man Lam ◽  
Ray Kit Ng
Keyword(s):  
Stem Cells ◽  
Transcription Factor ◽  
Cell Fate ◽  
Histone Demethylase ◽  
Gene Promoters ◽  
Transcriptional Program ◽  
Binding Motifs ◽  
Trophoblast Stem Cells ◽  
Trophoblast Stem ◽  
Trophoblast Stem Cell

AbstractTrophoblast stem cell (TSC) is crucial to the formation of placenta in mammals. Histone demethylase JMJD2 (also known as KDM4) family proteins have been previously shown to support self-renewal and differentiation of stem cells. However, their roles in the context of the trophoblast lineage remain unclear. Here, we find that knockdown of Jmjd2b resulted in differentiation of TSCs, suggesting an indispensable role of JMJD2B/KDM4B in maintaining the stemness. Through the integration of transcriptome and ChIP-seq profiling data, we show that JMJD2B is associated with a loss of H3K36me3 in a subset of embryonic lineage genes which are marked by H3K9me3 for stable repression. By characterizing the JMJD2B binding motifs and other transcription factor binding datasets, we discover that JMJD2B forms a protein complex with AP-2 family transcription factor TFAP2C and histone demethylase LSD1. The JMJD2B–TFAP2C–LSD1 complex predominantly occupies active gene promoters, whereas the TFAP2C–LSD1 complex is located at putative enhancers, suggesting that these proteins mediate enhancer–promoter interaction for gene regulation. We conclude that JMJD2B is vital to the TSC transcriptional program and safeguards the trophoblast cell fate via distinctive protein interactors and epigenetic targets.

Transcription factor-induced enhancer modulations during cell fate conversions

2013 ◽  
Vol 23 (5) ◽  
pp. 562-567 ◽  
Author(s):  
C van Oevelen ◽  
EM Kallin ◽  
T Graf
Keyword(s):  
Transcription Factor ◽  
Cell Fate

scholarly journals The mitochondrial iron exporter genes MMT1 and MMT2 in yeast are transcriptionally regulated by Aft1 and Yap1

2020 ◽  
Vol 295 (6) ◽  
pp. 1716-1726 ◽  
Author(s):  
Liangtao Li ◽  
Sophie Bertram ◽  
Jerry Kaplan ◽  
Xuan Jia ◽  
Diane M. Ward
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Transcription Factor ◽  
Promoter Region ◽  
Iron Transport ◽  
Mitochondrial Proteins ◽  
Upstream Region ◽  
Iron Sulfur Cluster ◽  
High Affinity ◽  
Iron Sulfur ◽  
Mitochondrial Iron

Budding yeast (Saccharomyces cerevisiae) responds to low cytosolic iron by up-regulating the expression of iron import genes; iron import can reflect iron transport into the cytosol or mitochondria. Mmt1 and Mmt2 are nuclearly encoded mitochondrial proteins that export iron from the mitochondria into the cytosol. Here we report that MMT1 and MMT2 expression is transcriptionally regulated by two pathways: the low-iron-sensing transcription factor Aft1 and the oxidant-sensing transcription factor Yap1. We determined that MMT1 and MMT2 expression is increased under low-iron conditions and decreased when mitochondrial iron import is increased through overexpression of the high-affinity mitochondrial iron importer Mrs3. Moreover, loss of iron-sulfur cluster synthesis induced expression of MMT1 and MMT2. We show that exposure to the oxidant H2O2 induced MMT1 expression but not MMT2 expression and identified the transcription factor Yap1 as being involved in oxidant-mediated MMT1 expression. We defined Aft1- and Yap1-dependent transcriptional sites in the MMT1 promoter that are necessary for low-iron- or oxidant-mediated MMT1 expression. We also found that the MMT2 promoter contains domains that are important for regulating its expression under low-iron conditions, including an upstream region that appears to partially repress expression under low-iron conditions. Our findings reveal that MMT1 and MMT2 are induced under low-iron conditions and that the low-iron regulator Aft1 is required for this induction. We further uncover an Aft1-binding site in the MMT1 promoter sufficient for inducing MMT1 transcription and identify an MMT2 promoter region required for low iron induction.

scholarly journals Dissecting Hes-centered transcriptional networks in neural stem cell maintenance and tumorigenesis in Drosophila

2020 ◽  
Author(s):  
Srivathsa S. Magadi ◽  
Chrysanthi Voutyraki ◽  
Gerasimos Anagnostopoulos ◽  
Evanthia Zacharioudaki ◽  
Ioanna K. Poutakidou ◽  
...  
Keyword(s):  
Stem Cells ◽  
Nervous System ◽  
Transcription Factor ◽  
Stem Cell ◽  
Neural Stem Cells ◽  
Cell Fate ◽  
Asymmetric Cell Division ◽  
Transcriptional Networks ◽  
Malignant Tumours ◽  
Stem Cell Maintenance

ABSTRACTNeural stem cells divide during embryogenesis and post embryonic development to generate the entire complement of neurons and glia in the nervous system of vertebrates and invertebrates. Studies of the mechanisms controlling the fine balance between neural stem cells and more differentiated progenitors have shown that in every asymmetric cell division progenitors send a Delta-Notch signal back to their sibling stem cells. Here we show that excessive activation of Notch or overexpression of its direct targets of the Hes family causes stem-cell hyperplasias in the Drosophila larval central nervous system, which can progress to malignant tumours after allografting to adult hosts. We combined transcriptomic data from these hyperplasias with chromatin occupancy data for Dpn, a Hes transcription factor, to identify genes regulated by Hes factors in this process. We show that the Notch/Hes axis represses a cohort of transcription factor genes. These are excluded from the stem cells and promote early differentiation steps, most likely by preventing the reversion of immature progenitors to a stem-cell fate. Our results suggest that Notch signalling sets up a network of mutually repressing stemness and anti-stemness transcription factors, which include Hes proteins and Zfh1, respectively. This mutual repression ensures robust transition to neuronal and glial differentiation and its perturbation can lead to malignant transformation.

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