Recruitment of histone deacetylase 4 by transcription factors represses interleukin-5 transcription

The critical role of IL-5 (interleukin-5) in eosinophilic inflammation implicates it as a therapeutic target for allergic diseases. The aim of the present study was to elucidate the molecular basis for the involvement of reversible histone acetylation in IL-5 transcriptional regulation. We provide evidence that HDAC4 (histone deacetylase 4) and p300, a known HAT (histone acetyltransferase), reversibly controlled the activity of the IL-5 promoter in vivo and in vitro, with a concurrent alteration of histone H3 acetylation status at the promoter regions. The nucleo-cytoplasmic shuttling of HDAC4 was shown to play an important role in the suppressive function of HDAC4 in IL-5 gene expression. Point mutation and reporter ChIP (chromatin immunoprecipitation) studies determined that the four transcription factors binding on the IL-5 promoter, i.e. C/EBPβ (CAAT/enhancer-binding protein β), GATA3 (GATA binding protein 3), NFAT (nuclear factor of activated T cells) and YY1 (Yin and Yang 1), were essential for the recruitment of HDAC4. Consistent with these observations, HDAC4 was found to form protein complexes with GATA3 and YY1, and to co-exist in the nuclei with GATA3. We propose that the unique regulatory mechanism of IL-5 gene transcription involves the reversible histone modification catalysed by HDAC4 and p300, which are recruited by the transcription factors. The dynamic balance in IL-5 transcriptional regulation is achieved through interactions among HATs/HDACs, histones and transcription factors. These data contribute to understanding the molecular mechanisms of IL-5 regulation, which is crucial to the development of new therapeutic strategies for IL-5-related allergic diseases.

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Study of expression analysis of SIRT4 and the coordinate regulation of bovine adipocyte differentiation by SIRT4 and its transcription factors

Bioscience Reports ◽

10.1042/bsr20181705 ◽

2018 ◽

Vol 38 (6) ◽

Cited By ~ 6

Author(s):

Jieyun Hong ◽

Shijun Li ◽

Xiaoyu Wang ◽

Chugang Mei ◽

Linsen Zan

Keyword(s):

Transcriptional Regulation ◽

Transcription Factors ◽

Adipocyte Differentiation ◽

Binding Protein ◽

Core Promoter ◽

Critical Role ◽

Luciferase Reporter ◽

Marker Genes ◽

Gene Assay ◽

Bovine Adipocytes

Sirtuins, NAD+-dependent deacylases and ADP-ribosyltransferases, are critical regulators of metabolism involved in many biological processes, and are involved in mediating adaptive responses to the cellular environment. SIRT4 is a mitochondrial sirtuin and has been shown to play a critical role in maintaining insulin secretion and glucose homeostasis. As a regulator of lipid homeostasis, SIRT4 can repress fatty acid oxidation and promote lipid anabolism in nutrient-replete conditions. Using real-time quantitative PCR (qPCR) to explore the molecular mechanisms of transcriptional regulation of bovine SIRT4 during adipocyte differentiation, we found that bovine SIRT4 is expressed at high levels in bovine subcutaneous adipose tissue. SIRT4 knockdown led to decreased expression of adipogenic differentiation marker genes during adipocyte differentiation. The core promoter of bovine SIRT4 was identified in the −402/−60 bp region of the cloned 2-kb fragment containing the 5′-regulatory region. Binding sites were identified in this region for E2F transcription factor-1 (E2F1), CCAAT/enhancer-binding protein β (CEBPβ), homeobox A5 (HOXA5), interferon regulatory factor 4 (IRF4), paired box 4 (PAX4), and cAMP responsive element-binding protein 1 (CREB1) by using Electrophoretic mobility shift assay (EMSA) and luciferase reporter gene assay. We also found that E2F1, CEBPβ, and HOXA5 transcriptionally activate SIRT4 expression, whereas, IRF4, PAX4, and CREB1 transcriptionally repress SIRT4 expression. We further verified that SIRT4 knockdown could affect the ability of these transcription factors (TFs) to regulate the differentiation of bovine adipocytes. In conclusion, our results shed light on the mechanisms underlying the transcriptional regulation of SIRT4 expression in bovine adipocytes.

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Understanding Adipocyte Differentiation

Physiological Reviews ◽

10.1152/physrev.1998.78.3.783 ◽

1998 ◽

Vol 78 (3) ◽

pp. 783-809 ◽

Cited By ~ 1498

Author(s):

FRANCINE M. GREGOIRE ◽

CYNTHIA M. SMAS ◽

HEI SOOK SUL

Keyword(s):

Adipose Tissue ◽

Transcription Factors ◽

Transcriptional Activation ◽

Molecular Mechanisms ◽

Adipocyte Differentiation ◽

Binding Protein ◽

Critical Role ◽

Tissue Growth ◽

Fatty Acid Binding ◽

Ppar Γ

Gregoire, Francine M., Cynthia M. Smas, and Hei Sook Sul. Understanding Adipocyte Differentiation. Physiol. Rev. 78: 783–809, 1998. — The adipocyte plays a critical role in energy balance. Adipose tissue growth involves an increase in adipocyte size and the formation of new adipocytes from precursor cells. For the last 20 years, the cellular and molecular mechanisms of adipocyte differentiation have been extensively studied using preadipocyte culture systems. Committed preadipocytes undergo growth arrest and subsequent terminal differentiation into adipocytes. This is accompanied by a dramatic increase in expression of adipocyte genes including adipocyte fatty acid binding protein and lipid-metabolizing enzymes. Characterization of regulatory regions of adipose-specific genes has led to the identification of the transcription factors peroxisome proliferator-activated receptor-γ (PPAR-γ) and CCAAT/enhancer binding protein (C/EBP), which play a key role in the complex transcriptional cascade during adipocyte differentiation. Growth and differentiation of preadipocytes is controlled by communication between individual cells or between cells and the extracellular environment. Various hormones and growth factors that affect adipocyte differentiation in a positive or negative manner have been identified. In addition, components involved in cell-cell or cell-matrix interactions such as preadipocyte factor-1 and extracellular matrix proteins are also pivotal in regulating the differentiation process. Identification of these molecules has yielded clues to the biochemical pathways that ultimately result in transcriptional activation via PPAR-γ and C/EBP. Studies on the regulation of the these transcription factors and the mode of action of various agents that influence adipocyte differentiation will reveal the physiological and pathophysiological mechanisms underlying adipose tissue development.

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LRRK2 mediates microglial neurotoxicity via NFATc2 in rodent models of synucleinopathies

Science Translational Medicine ◽

10.1126/scitranslmed.aay0399 ◽

2020 ◽

Vol 12 (565) ◽

pp. eaay0399

Author(s):

Changyoun Kim ◽

Alexandria Beilina ◽

Nathan Smith ◽

Yan Li ◽

Minhyung Kim ◽

...

Keyword(s):

Molecular Mechanisms ◽

Nuclear Translocation ◽

Critical Role ◽

Lewy Bodies ◽

Neuronal Loss ◽

Activated T Cells ◽

Behavioral Deficits ◽

Downstream Signaling ◽

Toll Like Receptor 2 ◽

Factor Α

Synucleinopathies are neurodegenerative disorders characterized by abnormal α-synuclein deposition that include Parkinson’s disease, dementia with Lewy bodies, and multiple system atrophy. The pathology of these conditions also includes neuronal loss and neuroinflammation. Neuron-released α-synuclein has been shown to induce neurotoxic, proinflammatory microglial responses through Toll-like receptor 2, but the molecular mechanisms involved are poorly understood. Here, we show that leucine-rich repeat kinase 2 (LRRK2) plays a critical role in the activation of microglia by extracellular α-synuclein. Exposure to α-synuclein was found to enhance LRRK2 phosphorylation and activity in mouse primary microglia. Furthermore, genetic and pharmacological inhibition of LRRK2 markedly diminished α-synuclein–mediated microglial neurotoxicity via lowering of tumor necrosis factor–α and interleukin-6 expression in mouse cultures. We determined that LRRK2 promoted a neuroinflammatory cascade by selectively phosphorylating and inducing nuclear translocation of the immune transcription factor nuclear factor of activated T cells, cytoplasmic 2 (NFATc2). NFATc2 activation was seen in patients with synucleinopathies and in a mouse model of synucleinopathy, where administration of an LRRK2 pharmacological inhibitor restored motor behavioral deficits. Our results suggest that modulation of LRRK2 and its downstream signaling mediator NFATc2 might be therapeutic targets for treating synucleinopathies.

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c-Jun, Foxo3a, and c-Myc Transcription Factors are Key Regulators of ATP-Mediated Angiogenic Responses in Pulmonary Artery Vasa Vasorum Endothelial Cells †

Cells ◽

10.3390/cells9020416 ◽

2020 ◽

Vol 9 (2) ◽

pp. 416

Author(s):

Derek Strassheim ◽

Vijaya Karoor ◽

Hala Nijmeh ◽

Philip Weston ◽

Martin Lapel ◽

...

Keyword(s):

Endothelial Cells ◽

Transcription Factors ◽

Pulmonary Artery ◽

Molecular Mechanisms ◽

Cell Cycle Control ◽

Critical Role ◽

Mammalian Target Of Rapamycin ◽

Vasa Vasorum ◽

Angiogenic Factor ◽

Angiogenic Genes

Angiogenic vasa vasorum (VV) expansion plays an essential role in the pathogenesis of hypoxia-induced pulmonary hypertension (PH), a cardiovascular disease. We previously showed that extracellular ATP released under hypoxic conditions is an autocrine/paracrine, the angiogenic factor for pulmonary artery (PA) VV endothelial cells (VVECs), acting via P2Y purinergic receptors (P2YR) and the Phosphoinositide 3-kinase (PI3K)-Akt-Mammalian Target of Rapamycin (mTOR) signaling. To further elucidate the molecular mechanisms of ATP-mediated VV angiogenesis, we determined the profile of ATP-inducible transcription factors (TFs) in VVECs using a TranSignal protein/DNA array. C-Jun, c-Myc, and Foxo3 were found to be upregulated in most VVEC populations and formed nodes connecting several signaling networks. siRNA-mediated knockdown (KD) of these TFs revealed their critical role in ATP-induced VVEC angiogenic responses and the regulation of downstream targets involved in tissue remodeling, cell cycle control, expression of endothelial markers, cell adhesion, and junction proteins. Our results showed that c-Jun was required for the expression of ATP-stimulated angiogenic genes, c-Myc was repressive to anti-angiogenic genes, and Foxo3a predominantly controlled the expression of anti-apoptotic and junctional proteins. The findings from our study suggest that pharmacological targeting of the components of P2YR-PI3K-Akt-mTOR axis and specific TFs reduced ATP-mediated VVEC angiogenic response and may have a potential translational significance in attenuating pathological vascular remodeling.

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Nuclear Factor of Activated T Cells (NFAT)-dependent Transactivation Regulated by the Coactivators p300/CREB-binding Protein (CBP)

Journal of Experimental Medicine ◽

10.1084/jem.187.12.2031 ◽

1998 ◽

Vol 187 (12) ◽

pp. 2031-2036 ◽

Cited By ~ 134

Author(s):

Carmen García-Rodríguez ◽

Anjana Rao

Keyword(s):

T Cells ◽

Binding Protein ◽

Critical Role ◽

Regulation Of Transcription ◽

Dependent Manner ◽

Nuclear Factor ◽

Transactivation Domain ◽

Creb Binding Protein ◽

Activated T Cells ◽

Viral Oncoprotein

p300 and cAMP response element–binding protein (CREB)–binding protein (CBP) are members of a family of coactivators involved in the regulation of transcription and chromatin. We show that transcription factors of the nuclear factor of activated T cells (NFAT) family bind p300/CBP and recruit histone acetyltransferase activity from T cell nuclear extracts. The NH2-terminal transactivation domain of NFAT1 and the phospho-CREB- and E1A-binding sites of p300/CBP are involved in the interaction. The viral oncoprotein E1A inhibits NFAT-dependent transactivation in a p300-dependent manner. Recruitment of the coactivators p300/CBP by the transactivation domains of NFAT proteins is likely to play a critical role in NFAT-dependent gene expression during the immune response.

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NFAT pulls the strings during CD4+ T helper cell effector functions

Blood ◽

10.1182/blood-2009-10-233585 ◽

2010 ◽

Vol 115 (15) ◽

pp. 2989-2997 ◽

Cited By ~ 115

Author(s):

Natascha Hermann-Kleiter ◽

Gottfried Baier

Keyword(s):

Transcription Factors ◽

T Cell ◽

Target Genes ◽

Binding Capacity ◽

Critical Role ◽

T Helper Cell ◽

Helper Cell ◽

T Helper ◽

Activated T Cells ◽

T Helper Subsets

Abstract The Ca2+ dependent transcription factor family known as nuclear factor of activated T cells (NFAT) has been shown to be important in T-cell immune responses. Because NFAT proteins have a weak DNA-binding capacity, they cooperate with other transcription factors at composite sites within the promoters of target genes. Recently, NFAT was shown to also be important for the induction of specific genetic programs that guide the differentiation and effector or regulatory activities of CD4+ T helper subsets via the transcriptional regulation of their lineage-specific transcription factors, specifically T-bet (Th1), Gata3 (Th2), RORγt (Th17), and Foxp3 (iTregs). In addition, the NFAT family governs the transcription of several signature cytokines, including their cytokine receptors. Subsequently, the integration of these complex intracellular signal transduction cascades is considered to critically determine the crosstalk between the T-cell receptor and receptors that are activated by both the adaptive and innate immune systems to determine pathways of T helper cell differentiation and function. Here, we carefully review the critical role of the established transcriptional partners and functional outcomes of these NFAT interactions in regard to the effector responses of these clinically relevant CD4+ T helper subsets.

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C-terminal truncated HBx initiates hepatocarcinogenesis by downregulating TXNIP and reprogramming glucose metabolism

Oncogene ◽

10.1038/s41388-020-01593-5 ◽

2020 ◽

Author(s):

Yu Zhang ◽

Qian Yan ◽

Lanqi Gong ◽

Hang Xu ◽

Beilei Liu ◽

...

Keyword(s):

Glucose Metabolism ◽

Molecular Mechanisms ◽

Critical Role ◽

Genetic Alterations ◽

Metabolic Reprogramming ◽

Mice Model ◽

Activated T Cells ◽

Chronic Hepatitis B Virus

AbstractChronic hepatitis B virus (HBV) infection is strongly associated with the initiation and development of hepatocellular carcinoma (HCC). However, the genetic alterations and pathogenesis mechanisms remain significantly unexplored, especially for HBV-induced metabolic reprogramming. Analysis of integration breakpoints in HBV-positive HCC samples revealed the preferential clustering pattern within the 3′-end of X gene in the HBV genome, leading to the production of C-terminal truncated X protein (Ct-HBx). In this study, we not only characterized the oncogenic role of two Ct-HBx (HBx-120 and HBx-134) via in vitro and in vivo functional assays but also deciphered their underlying molecular mechanisms. Gene expression profiling by transcriptome sequencing identified potential targets of Ct-HBx and novel malignant hallmarks such as glycolysis, cell cycle, and m-TORC1 signaling in Ct-HBx-expressing cells. TXNIP, a well-established regulator of glucose metabolism, was shown to be downregulated by Ct-HBx and play a pivotal role in Ct-HBx-mediated HCC progression. Suppression of TXNIP is frequently observed in HCC patients with Ct-HBx expression and significantly (P = 0.015) correlated to a poorer prognosis. Re-introduction of TXNIP attenuated the metabolic reprogramming induced by the Ct-HBx and inhibited the tumor growth in the mice model. Further study suggested that Ct-HBx could downregulate TXNIP via a transcriptional repressor nuclear factor of activated T cells 2 (NFACT2). Collectively, our findings indicate that TXNIP plays a critical role in Ct-HBx-mediated hepatocarcinogenesis, serving as a novel therapeutic strategy in HCC treatment.

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Metabolic and transcriptome responses of RNAi-mediated AMPKα knockdown in Tribolium castaneum

10.21203/rs.3.rs-24958/v3 ◽

2020 ◽

Author(s):

Heng Jiang ◽

Nan Zhang ◽

Caihong Ji ◽

Xiangkun Meng ◽

Kun Qian ◽

...

Keyword(s):

Transcription Factors ◽

Carbohydrate Metabolism ◽

Tribolium Castaneum ◽

Binding Protein ◽

Quantitative Polymerase Chain Reaction ◽

Critical Role ◽

Whole Body ◽

Regulation Of Transcription ◽

Valuable Insight ◽

Element Binding Protein

Abstract Background The AMP-activated protein kinase (AMPK) is an intracellular fuel sensor for lipid and glucose metabolism. In addition to the short-term regulation of metabolic enzymes by phosphorylation, AMPK may also exert long-term effects on the transcription of downstream genes through the regulation of transcription factors and coactivators. In this study, RNA interference (RNAi) was conducted to investigate the effects of knockdown of TcAMPKα on lipid and carbohydrate metabolism in the red flour beetle, Tribolium castaneum, and the transcriptome profiles of dsTcAMPKα-injected and dsEGFP-injected beetles under normal conditions were compared by RNA-sequencing.Results RNAi-mediated suppression of TcAMPKα increased whole-body triglyceride (TG) level and the ratio between glucose and trehalose, as was confirmed by in vivo treatment with the AMPK-activating compound, 5-Aminoimidazole-4-carboxamide1-β-D-ribofuranoside (AICAR). A total of 1184 differentially expressed genes (DEGs) were identified between dsTcAMPKα-injected and dsEGFP-injected beetles. These include genes involved in lipid and carbohydrate metabolism as well as insulin/insulin-like growth factor signaling (IIS). Real-time quantitative polymerase chain reaction analysis confirmed the differential expression of selected genes. Interestingly, metabolism-related transcription factors such as sterol regulatory element-binding protein 1 (SREBP1) and carbohydrate response element-binding protein (ChREBP) were also significantly upregulated in dsTcAMPKα-injected beetles. Conclusions AMPK plays a critical role in the regulation of beetle metabolism. The findings of DEGs involved in lipid and carbohydrate metabolism provide valuable insight into the role of AMPK signaling in the transcriptional regulation of insect metabolism.

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Metabolic and transcriptome responses of RNAi-mediated AMPKα knockdown in Tribolium castaneum

10.21203/rs.3.rs-24958/v1 ◽

2020 ◽

Author(s):

Heng Jiang ◽

Nan Zhang ◽

Caihong Ji ◽

Xiangkun Meng ◽

Kun Qian ◽

...

Keyword(s):

Transcription Factors ◽

Carbohydrate Metabolism ◽

Tribolium Castaneum ◽

Binding Protein ◽

Quantitative Polymerase Chain Reaction ◽

Critical Role ◽

Whole Body ◽

Regulation Of Transcription ◽

Valuable Insight ◽

Element Binding Protein

Abstract Background The AMP-activated protein kinase (AMPK) is an intracellular fuel sensor for lipid and glucose metabolism. In addition to the short-term regulation of metabolic enzymes by phosphorylation, AMPK may also exert long-term effects on the transcription of downstream genes through the regulation of transcription factors and coactivators. In this study, RNA interference (RNAi) was conducted to investigate the effects of knockdown of TcAMPKα on lipid and carbohydrate metabolism in the red flour beetle, Tribolium castaneum, and the transcriptome profiles of dsTcAMPKα-injected and dsEGFP-injected beetles under normal conditions were comparatively analyzed by RNA-sequencing. Results RNAi-mediated suppression of TcAMPKα increased whole-body triglyceride (TG) level and the ratio between glucose and trehalose, as was confirmed by in vivo treatment with the AMPK-activating compound, 5-Aminoimidazole-4-carboxamide1-β-D-ribofuranoside (AICAR). A total of 1184 differentially expressed genes (DEGs) were identified between dsTcAMPKα-injected and dsEGFP-injected beetles. These include genes involved in lipid and carbohydrate metabolism as well as insulin/insulin-like growth factor signaling (IIS). Real-time quantitative polymerase chain reaction analysis confirmed the differential expression of selected genes. Interestingly, metabolism-related transcription factors such as sterol regulatory element-binding protein 1 (SREBP1) and carbohydrate response element-binding protein (ChREBP) were also significantly upregulated in dsTcAMPKα-injected beetles. Conclusions AMPK plays a critical role in the regulation of beetle metabolism. The findings of DEGs involved in lipid and carbohydrate metabolism provide valuable insight into the role of AMPK signaling in the transcriptional regulation of insect metabolism.

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Importins and Exportins Regulating Allergic Immune Responses

Mediators of Inflammation ◽

10.1155/2014/476357 ◽

2014 ◽

Vol 2014 ◽

pp. 1-14 ◽

Cited By ~ 18

Author(s):

Ankita Aggarwal ◽

Devendra K. Agrawal

Keyword(s):

Transcription Factors ◽

Nuclear Export ◽

Molecular Mechanisms ◽

Allergic Diseases ◽

Nuclear Pore ◽

Nuclear Pore Complexes ◽

Immune Modulators ◽

Nuclear Localization Signals ◽

Intracellular Signals ◽

Pore Complexes

Nucleocytoplasmic shuttling of macromolecules is a well-controlled process involving importins and exportins. These karyopherins recognize and bind to receptor-mediated intracellular signals through specific signal sequences that are present on cargo proteins and transport into and out of the nucleus through nuclear pore complexes. Nuclear localization signals (NLS) present on cargo molecules to be imported while nuclear export signals (NES) on the molecules to be exported are recognized by importins and exportins, respectively. The classical NLS are found on many transcription factors and molecules that are involved in the pathogenesis of allergic diseases. In addition, several immune modulators, including corticosteroids and vitamin D, elicit their cellular responses by regulating the expression and activity of importin molecules. In this review article, we provide a comprehensive list of importin and exportin molecules and their specific cargo that shuttled between cytoplasm and the nucleus. We also critically review the role and regulation of specific importin and exportin involved in the transport of activated transcription factors in allergic diseases, the underlying molecular mechanisms, and the potential target sites for developing better therapeutic approaches.

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