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1.
Drug Resist Updat ; 66: 100913, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36603431

RESUMO

AIMS: Chemoresistance remains a major challenge in gastric cancer (GC). Chromodomain helicase DNA-binding protein 4 (CHD4) mediated chromatin remodeling plays critical roles in various tumor types, but its role in chemoresistance in GC remains uncharacterized. METHODS: CHD4 expression was examined by immunohistochemistry and Western blotting. The role of CHD4 on cell proliferation and chemoresistance of GC was examined in vitro and in vivo. Immunoprecipitation and liquid chromatography-mass spectrometry were used to identify CHD4-binding proteins and a proximity ligation assay was used to explore protein-protein interaction. RESULTS: Chemoresistance is associated with upregulation of CHD4 in the tumor tissues of GC patients. Overexpression of CHD4 increased chemoresistance and cell proliferation. Knockdown of CHD4 induced cell apoptosis and cell cycle arrest. CHD4 mediates the decrease of the intracellular concentration of cisplatin by inducing drug efflux. Additionally, CHD4 promotes the interaction between ERK1/2 and MEK1/2, resulting in continuous activation of MEK/ERK pathway. Knockdown of CHD4 in GC increased sensitivity to chemotherapy and suppressed tumor growth in a mouse xenograft model. CONCLUSIONS: This study identifies CHD4 dominated multi-drug efflux as a promising therapeutic target for overcoming acquired chemoresistance in GC.


Assuntos
Cisplatino , Resistencia a Medicamentos Antineoplásicos , Animais , Humanos , Camundongos , Pontos de Checagem do Ciclo Celular , Linhagem Celular Tumoral , Proliferação de Células , Cisplatino/farmacologia , Cisplatino/uso terapêutico , Resistencia a Medicamentos Antineoplásicos/genética , Regulação Neoplásica da Expressão Gênica , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase , Quinases de Proteína Quinase Ativadas por Mitógeno , MAP Quinases Reguladas por Sinal Extracelular/metabolismo
2.
J Transl Med ; 21(1): 38, 2023 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-36681835

RESUMO

BACKGROUND: The overall survival rate of patients with advanced ovarian cancer (OC) has remained static for several decades. Advanced ovarian cancer is known for its poor prognosis due to extensive metastasis. Epigenetic alterations contribute to tumour progression and therefore are of interest for potential therapeutic strategies. METHODS: Following our previous study, we identified that CHD4, a chromatin remodelling factor, plays a strong role in ovarian cancer cell metastasis. We investigated the clinical significance of CHD4 through TCGA and GEO database analyses and explored the effect of CHD4 expression modulation and romidepsin treatment on the biological behaviour of ovarian cancer through CCK-8 and transwell assays. Bioluminescence imaging of tumours in xenografted mice was applied to determine the therapeutic effect of romidepsin. GSEA and western blotting were used to screen the regulatory mechanism of CHD4. RESULTS: In ovarian cancer patient specimens, high CHD4 expression was associated with a poor prognosis. Loss of function of CHD4 in ovarian cancer cells induced suppression of migration and invasion. Mechanistically, CHD4 knockdown suppressed the expression of EZH2 and the nuclear accumulation of ß-catenin. CHD4 also suppressed the metastasis of ovarian cancer cells and prevented disease progression in a mouse model. To inhibit the functions of CHD4 that are mediated by histone deacetylase, we evaluated the effect of the HDAC1/2 selective inhibitor romidepsin. Our findings indicated that treatment with romidepsin suppressed the progression of metastases in vitro and in vivo. CONCLUSIONS: Collectively, our results uncovered an oncogenic function of CHD4 in ovarian cancer and provide a rationale for clinical trials of romidepsin in ovarian cancer patients.


Assuntos
Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase , Neoplasias Ovarianas , Humanos , Feminino , Animais , Camundongos , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/genética , beta Catenina , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/genética , Epigênese Genética , Linhagem Celular Tumoral , Proteína Potenciadora do Homólogo 2 de Zeste/genética
3.
Nat Commun ; 14(1): 448, 2023 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-36707513

RESUMO

Chromatin regulators are frequently mutated in human cancer and are attractive drug targets. They include diverse proteins that share functional domains and assemble into related multi-subunit complexes. To investigate functional relationships among these regulators, here we apply combinatorial CRISPR knockouts (KOs) to test over 35,000 gene-gene pairings in leukemia cells, using a library of over 300,000 constructs. Top pairs that demonstrate either compensatory non-lethal interactions or synergistic lethality enrich for paralogs and targets that occupy the same protein complex. The screen highlights protein complex dependencies not apparent in single KO screens, for example MCM histone exchange, the nucleosome remodeling and deacetylase (NuRD) complex, and HBO1 (KAT7) complex. We explore two approaches to NuRD complex inactivation. Paralog and non-paralog combinations of the KAT7 complex emerge as synergistic lethal and specifically nominate the ING5 PHD domain as a potential therapeutic target when paired with other KAT7 complex member losses. These findings highlight the power of combinatorial screening to provide mechanistic insight and identify therapeutic targets within redundant networks.


Assuntos
Cromatina , Leucemia , Humanos , Cromatina/genética , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/metabolismo , Montagem e Desmontagem da Cromatina , Leucemia/tratamento farmacológico , Leucemia/genética , Histona Acetiltransferases/metabolismo
4.
J Biol Chem ; 299(1): 102812, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36539038

RESUMO

CXXC5, a member of the CXXC family of zinc-finger proteins, is associated with numerous pathological processes. However, the pathophysiological function of CXXC5 has not been clearly established. Herein, we found that CXXC5 interacts with the CRL4B and NuRD complexes. Screening of transcriptional targets downstream of the CXXC5-CRL4B-NuRD complex by next-generation sequencing (chromatin immunoprecipitation sequencing) revealed that the complex regulates the transcriptional repression process of a cohort of genes, including TSC1 (tuberous sclerosis complex subunit 1), which play important roles in cell growth and mammalian target of rapamycin signaling pathway regulation, and whose abnormal regulation results in the activation of programmed cell death-ligand protein 1 (PD-L1). Intriguingly, CXXC5 expression increased after stimulation with vitamin B2 but decreased after vitamin D treatment. We also found that the CXXC5-CRL4B-NuRD complex promotes the proliferation of tumor cells in vitro and accelerates the growth of breast cancer in vivo. The expression of CXXC5, CUL4B, and MTA1 increased during the occurrence and development of breast cancer, and correspondingly, TSC1 expression decreased. Meanwhile, a high expression of CXXC5 was positively correlated with the histological grade of high malignancy and poor survival of patients. In conclusion, our study revealed that CXXC5-mediated TSC1 suppression activates the mammalian target of rapamycin pathway, reduces autophagic cell death, induces PD-L1-mediated immune suppression, and results in tumor development, shedding light on the mechanism of the pathophysiological function of CXXC5.


Assuntos
Antígeno B7-H1 , Neoplasias da Mama , Humanos , Feminino , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/genética , Transdução de Sinais , Serina-Treonina Quinases TOR/genética , Transformação Celular Neoplásica , Neoplasias da Mama/genética , Zinco , Proteínas Repressoras , Transativadores , Proteínas Culina , Proteínas de Ligação a DNA/genética
5.
Pathol Res Pract ; 240: 154173, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36306724

RESUMO

Inorganic arsenic (iAs), a known human carcinogen, induces oxidative DNA damage and epigenetic silencing of tumor suppressor genes related to tumor progression. Chromodomain-helicase-DNA-binding protein 4 (CHD4) is a chromatin remodeling protein that acts on DNA repair and DNA methylation under oxidative damage in malignancies, but the role of CHD4 in arsenical urothelial carcinoma (UC) is unidentified. Our purpose was to observe CHD4-related repair effects on As-stimulated oxidative damage in human UC. The markers of oxidative DNA damage 8-hydroxy-2'-deoxyguanosine (8-OHdG) and CHD4 were investigated by immunohistochemistry in 45 UC tissues from non-blackfoot disease (BFD) areas and BFD areas respectively. The cellular mechanisms of CHD4 involved in the oxidative DNA repair and DNA methylation were evaluated by immunocytochemistry and western blot. The expressions of CHD4 and 8-OHdG were significantly increased in UC patients from the As-exposed areas. The underlying mechanism of CHD4-mediated DNA repair and DNA methylation involved the activation of zinc finger MYND-type containing 8 (ZMYND8) and DNA methyltransferase (DNMTs) in SV-HUC-1, T24 and BFTC-905 cells. These results highlight the potential clinical significance of CHD4 in UCs from BFD areas. The CHD4-mediated oxidative DNA repair and epigenetic DNA methylation in UC cells stimulated by arsenic was revealed. CHD4 might be used as a prognostic indicator in arsenical UC.


Assuntos
Arsênio , Arsenitos , Carcinoma de Células de Transição , Neoplasias da Bexiga Urinária , Humanos , Carcinoma de Células de Transição/induzido quimicamente , Carcinoma de Células de Transição/metabolismo , Arsenitos/toxicidade , Neoplasias da Bexiga Urinária/induzido quimicamente , Estresse Oxidativo , Dano ao DNA , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/metabolismo
6.
BMC Biol ; 20(1): 209, 2022 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-36153585

RESUMO

BACKGROUND: SWI/SNF (BAF) chromatin remodeling complexes regulate lineage-specific enhancer activity by promoting accessibility for diverse DNA-binding factors and chromatin regulators. Additionally, they are known to modulate the function of the epigenome through regulation of histone post-translational modifications and nucleosome composition, although the way SWI/SNF complexes govern the epigenome remains poorly understood. Here, we investigate the function of ARID1A, a subunit of certain mammalian SWI/SNF chromatin remodeling complexes associated with malignancies and benign diseases originating from the uterine endometrium. RESULTS: Through genome-wide analysis of human endometriotic epithelial cells, we show that more than half of ARID1A binding sites are marked by the variant histone H3.3, including active regulatory elements such as super-enhancers. ARID1A knockdown leads to H3.3 depletion and gain of canonical H3.1/3.2 at ARID1A-bound active regulatory elements, and a concomitant redistribution of H3.3 toward genic elements. ARID1A interactions with the repressive chromatin remodeler CHD4 (NuRD) are associated with H3.3, and ARID1A is required for CHD4 recruitment to H3.3. ZMYND8 interacts with CHD4 to suppress a subset of ARID1A, CHD4, and ZMYND8 co-bound, H3.3+ H4K16ac+ super-enhancers near genes governing extracellular matrix, motility, adhesion, and epithelial-to-mesenchymal transition. Moreover, these gene expression alterations are observed in human endometriomas. CONCLUSIONS: These studies demonstrate that ARID1A-containing BAF complexes are required for maintenance of the histone variant H3.3 at active regulatory elements, such as super-enhancers, and this function is required for the physiologically relevant activities of alternative chromatin remodelers.


Assuntos
Cromatina , Proteínas de Ligação a DNA , Histonas , Fatores de Transcrição , Cromatina/genética , Montagem e Desmontagem da Cromatina , DNA , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Feminino , Histonas/genética , Humanos , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/genética , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/metabolismo , Nucleossomos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
7.
Int J Mol Sci ; 23(17)2022 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-36076959

RESUMO

The sarcomere regulates striated muscle contraction. This structure is composed of several myofibril proteins, isoforms of which are encoded by genes specific to either the heart or skeletal muscle. The chromatin remodeler complex Chd4/NuRD regulates the transcriptional expression of these specific sarcomeric programs by repressing genes of the skeletal muscle sarcomere in the heart. Aberrant expression of skeletal muscle genes induced by the loss of Chd4 in the heart leads to sudden death due to defects in cardiomyocyte contraction that progress to arrhythmia and fibrosis. Identifying the transcription factors (TFs) that recruit Chd4/NuRD to repress skeletal muscle genes in the myocardium will provide important information for understanding numerous cardiac pathologies and, ultimately, pinpointing new therapeutic targets for arrhythmias and cardiomyopathies. Here, we sought to find Chd4 interactors and their function in cardiac homeostasis. We therefore describe a physical interaction between Chd4 and the TF Znf219 in cardiac tissue. Znf219 represses the skeletal-muscle sarcomeric program in cardiomyocytes in vitro and in vivo, similarly to Chd4. Aberrant expression of skeletal-muscle sarcomere proteins in mouse hearts with knocked down Znf219 translates into arrhythmias, accompanied by an increase in PR interval. These data strongly suggest that the physical and genetic interaction of Znf219 and Chd4 in the mammalian heart regulates cardiomyocyte identity and myocardial contraction.


Assuntos
DNA Helicases/metabolismo , Proteínas de Ligação a DNA/metabolismo , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase , Miócitos Cardíacos/citologia , Miócitos Cardíacos/metabolismo , Fatores de Transcrição , Animais , Regulação da Expressão Gênica , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/metabolismo , Camundongos , Proteínas Musculares/genética , Proteínas Musculares/metabolismo , Nucleossomos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
8.
Protein Sci ; 31(9): e4387, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36040254

RESUMO

The nucleosome remodeling and deacetylase (NuRD) complex is a chromatin-modifying assembly that regulates gene expression and DNA damage repair. Despite its importance, limited structural information describing the complete NuRD complex is available and a detailed understanding of its mechanism is therefore lacking. Drawing on information from SEC-MALLS, DIA-MS, XLMS, negative-stain EM, X-ray crystallography, NMR spectroscopy, secondary structure predictions, and homology models, we applied Bayesian integrative structure determination to investigate the molecular architecture of three NuRD sub-complexes: MTA1-HDAC1-RBBP4, MTA1N -HDAC1-MBD3GATAD2CC , and MTA1-HDAC1-RBBP4-MBD3-GATAD2A [nucleosome deacetylase (NuDe)]. The integrative structures were corroborated by examining independent crosslinks, cryo-EM maps, biochemical assays, known cancer-associated mutations, and structure predictions from AlphaFold. The robustness of the models was assessed by jack-knifing. Localization of the full-length MBD3, which connects the deacetylase and chromatin remodeling modules in NuRD, has not previously been possible; our models indicate two different locations for MBD3, suggesting a mechanism by which MBD3 in the presence of GATAD2A asymmetrically bridges the two modules in NuRD. Further, our models uncovered three previously unrecognized subunit interfaces in NuDe: HDAC1C -MTA1BAH , MTA1BAH -MBD3MBD , and HDAC160-100 -MBD3MBD . Our approach also allowed us to localize regions of unknown structure, such as HDAC1C and MBD3IDR , thereby resulting in the most complete and robustly cross-validated structural characterization of these NuRD sub-complexes so far.


Assuntos
Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase , Nucleossomos , Teorema de Bayes , Montagem e Desmontagem da Cromatina , Histona Desacetilases/química , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/genética , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/metabolismo
9.
J Biol Chem ; 298(10): 102428, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36037972

RESUMO

The methyl-CpG-binding domain 2 and 3 proteins (MBD2 and MBD3) provide structural and DNA-binding function for the Nucleosome Remodeling and Deacetylase (NuRD) complex. The two proteins form distinct NuRD complexes and show different binding affinity and selectivity for methylated DNA. Previous studies have shown that MBD2 binds with high affinity and selectivity for a single methylated CpG dinucleotide while MBD3 does not. However, the NuRD complex functions in regions of the genome that contain many CpG dinucleotides (CpG islands). Therefore, in this work, we investigate the binding and diffusion of MBD2 and MBD3 on more biologically relevant DNA templates that contain a large CpG island or limited CpG sites. Using a combination of single-molecule and biophysical analyses, we show that both MBD2 and MBD3 diffuse freely and rapidly across unmethylated CpG-rich DNA. In contrast, we found methylation of large CpG islands traps MBD2 leading to stable and apparently static binding on the CpG island while MBD3 continues to diffuse freely. In addition, we demonstrate both proteins bend DNA, which is augmented by methylation. Together, these studies support a model in which MBD2-NuRD strongly localizes to and compacts methylated CpG islands while MBD3-NuRD can freely mobilize nucleosomes independent of methylation status.


Assuntos
Metilação de DNA , Proteínas de Ligação a DNA , Ilhas de CpG , Proteínas de Ligação a DNA/metabolismo , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/genética , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/metabolismo , Nucleossomos , Ligação Proteica , Fatores de Transcrição/metabolismo , Humanos , Imagem Individual de Molécula
10.
Sci Immunol ; 7(72): eabn5917, 2022 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-35687698

RESUMO

Although BTB-zinc finger (BTB-ZF) transcription factors control the differentiation of multiple hematopoietic and immune lineages, how they function is poorly understood. The BTB-ZF factor Thpok controls intrathymic CD4+ T cell development and the expression of most CD4+ and CD8+ lineage genes. Here, we identify the nucleosome remodeling and deacetylase (NuRD) complex as a critical Thpok cofactor. Using mass spectrometry and coimmunoprecipitation in primary T cells, we show that Thpok binds NuRD components independently of DNA association. We locate three amino acid residues within the Thpok BTB domain that are required for both NuRD binding and Thpok functions. Conversely, a chimeric protein merging the NuRD component Mta2 to a BTB-less version of Thpok supports CD4+ T cell development, indicating that NuRD recruitment recapitulates the functions of the Thpok BTB domain. We found that NuRD mediates Thpok repression of CD8+ lineage genes, including the transcription factor Runx3, but is dispensable for Cd4 expression. We show that these functions cannot be performed by the BTB domain of the Thpok-related factor Bcl6, which fails to bind NuRD. Thus, cofactor binding critically contributes to the functional specificity of BTB-ZF factors, which control the differentiation of most hematopoietic subsets.


Assuntos
Linfócitos T CD4-Positivos , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase , Diferenciação Celular , Linhagem da Célula , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/metabolismo , Fatores de Transcrição
11.
Development ; 149(11)2022 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-35695185

RESUMO

In the developing subpallium, the fate decision between neurons and glia is driven by expression of Dlx1/2 or Olig1/2, respectively, two sets of transcription factors with a mutually repressive relationship. The mechanism by which Dlx1/2 repress progenitor and oligodendrocyte fate, while promoting transcription of genes needed for differentiation, is not fully understood. We identified a motif within DLX1 that binds RBBP4, a NuRD complex subunit. ChIP-seq studies of genomic occupancy of DLX1 and six different members of the NuRD complex show that DLX1 and NuRD colocalize to putative regulatory elements enriched near other transcription factor genes. Loss of Dlx1/2 leads to dysregulation of genome accessibility at putative regulatory elements near genes repressed by Dlx1/2, including Olig2. Consequently, heterozygosity of Dlx1/2 and Rbbp4 leads to an increase in the production of OLIG2+ cells. These findings highlight the importance of the interplay between transcription factors and chromatin remodelers in regulating cell-fate decisions.


Assuntos
Proteínas de Homeodomínio , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase , Diferenciação Celular/genética , Genes Homeobox , Proteínas de Homeodomínio/metabolismo , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
12.
Immun Inflamm Dis ; 10(7): e644, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35759243

RESUMO

Chromodomain helicase DNA binding protein 4 (CHD4) is an ATPase subunit of the nucleosome remodeling and deacetylation complex. It has been implicated in gene transcription, DNA damage repair, maintenance of genome stability, and chromatin assembly. Meanwhile, it is highly related to cell cycle progression and the proceeding of malignancy. Most of the previous studies were focused on the function of CHD4 with tumor cells, cancer stem cells, and cancer cells multidrug resistance. Recently, some researchers have explored the CHD4 functions on the development and differentiation of adaptive immune cells, such as T and B lymphocytes. In this review, we will discuss details of CHD4 in lymphocyte differentiation and development, as well as the critical role of CHD4 in the pathogenesis of the autoimmune disease.


Assuntos
Doenças Autoimunes , Montagem e Desmontagem da Cromatina , Linfócitos B/metabolismo , Diferenciação Celular , Humanos , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/genética , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/metabolismo , Nucleossomos , Linfócitos T
13.
Epigenetics Chromatin ; 15(1): 16, 2022 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-35568926

RESUMO

Testis development and sustained germ cell production in adults rely on the establishment and maintenance of spermatogonia stem cells and their proper differentiation into spermatocytes. Chromatin remodeling complexes regulate critical processes during gamete development by restricting or promoting accessibility of DNA repair and gene expression machineries to the chromatin. Here, we investigated the role of Chd4 and Chd3 catalytic subunits of the NURD complex during spermatogenesis. Germ cell-specific deletion of chd4 early in gametogenesis, but not chd3, resulted in arrested early gamete development due to failed cell survival of neonate undifferentiated spermatogonia stem cell population. Candidate assessment revealed that Chd4 controls expression of dmrt1 and its downstream target plzf, both described as prominent regulators of spermatogonia stem cell maintenance. Our results show the requirement of Chd4 in mammalian gametogenesis pointing to functions in gene expression early in the process.


Assuntos
DNA Helicases/metabolismo , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase , Espermatogônias , Animais , Diferenciação Celular , Gônadas , Masculino , Mamíferos , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/genética , Camundongos , Fatores de Transcrição/genética
14.
Cell Rep ; 39(6): 110788, 2022 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-35545047

RESUMO

Kaposi sarcoma-associated herpesvirus (KSHV) establishes a latent infection in the cell nucleus, but where KSHV episomal genomes are tethered and the mechanisms underlying KSHV lytic reactivation are unclear. Here, we study the nuclear microenvironment of KSHV episomes and show that the KSHV latency-lytic replication switch is regulated via viral long non-coding (lnc)RNA-CHD4 (chromodomain helicase DNA binding protein 4) interaction. KSHV episomes localize with CHD4 and ADNP proteins, components of the cellular ChAHP complex. The CHD4 and ADNP proteins occupy the 5'-region of the highly inducible lncRNAs and terminal repeats of the KSHV genome together with latency-associated nuclear antigen (LANA). Viral lncRNA binding competes with CHD4 DNA binding, and KSHV reactivation sequesters CHD4 from the KSHV genome, which is also accompanied by detachment of KSHV episomes from host chromosome docking sites. We propose a model in which robust KSHV lncRNA expression determines the latency-lytic decision by regulating LANA/CHD4 binding to KSHV episomes.


Assuntos
Herpesvirus Humano 8 , RNA Longo não Codificante , Sarcoma de Kaposi , Antígenos Virais/genética , Antígenos Virais/metabolismo , Cromossomos/metabolismo , Herpesvirus Humano 8/genética , Humanos , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/genética , Plasmídeos , RNA Longo não Codificante/genética , Microambiente Tumoral , Latência Viral/genética
15.
J Mol Endocrinol ; 69(2): 329-341, 2022 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-35521759

RESUMO

Type 2 diabetes (T2D) is associated with loss of transcription factors (TFs) from a subset of failing ß-cells. Among these TFs is Pdx1, which controls the expression of numerous genes involved in maintaining ß-cell function and identity. Pdx1 activity is modulated by transcriptional coregulators and has recently been shown, through an unbiased screen, to interact with the Chd4 ATPase subunit of the nucleosome remodeling and deacetylase complex. Chd4 contributes to the maintenance of cellular identity and functional status of numerous different cell types. Here, we demonstrated that Pdx1 dynamically interacts with Chd4 under physiological and stimulatory conditions within islet ß-cells and established a fundamental role for Chd4 in regulating insulin secretion and modulating numerous Pdx1-bound genes in vitro, including the MafA TF, where we discovered Chd4 is bound to the MafA region 3 enhancer. Furthermore, we found that Pdx1:Chd4 interactions are significantly compromised in islet ß-cells under metabolically induced stress in vivo and in human donor tissues with T2D. Our findings establish a fundamental role for Chd4 in regulating insulin secretion and modulating Pdx1-bound genes in vitro, and disruption of Pdx1:Chd4 interactions coincides with ß-cell dysfunction associated with T2D.


Assuntos
Diabetes Mellitus Tipo 2 , Células Secretoras de Insulina , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Proteínas de Homeodomínio/metabolismo , Humanos , Células Secretoras de Insulina/metabolismo , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/genética , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/metabolismo , Transativadores/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
16.
Br J Cancer ; 127(4): 612-623, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35501390

RESUMO

BACKGROUND: The mechanism of recurrence and metastasis of hepatocellular carcinoma (HCC) is complex and challenging. Methyl-CpG binding domain protein 3 (MBD3) is a key epigenetic regulator involved in the progression and metastasis of several cancers, but its role in HCC remains unknown. METHODS: MBD3 expression in HCC was detected by immunohistochemistry and its association with clinicopathological features and patient's survival was analysed. The effects of MBD3 on hepatoma cells growth and metastasis were investigated, and the mechanism was explored. RESULTS: MBD3 is significantly highly expressed in HCC, associated with the advanced tumour stage and poor prognosis in HCC patients. MBD3 promotes the growth, angiogenesis and metastasis of HCC cells by inhibiting the tumour suppressor tissue factor pathway inhibitor 2 (TFPI2). Mechanistically, MBD3 can inhibit the TFPI2 transcription via the Nucleosome Remodeling and Deacetylase (NuRD) complex-mediated deacetylation, thus reactivating the activity of matrix metalloproteinases (MMPs) and PI3K/AKT signaling pathway, leading to the progression and metastasis of HCC CONCLUSIONS: Our results unravel the novel regulatory function of MBD3 in the progression and metastasis of HCC and identify MBD3 as an independent unfavourable prognostic factor for HCC patients, suggesting its potential as a promising therapeutic target as well.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Carcinoma Hepatocelular/metabolismo , Linhagem Celular Tumoral , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Regulação Neoplásica da Expressão Gênica , Glicoproteínas , Humanos , Neoplasias Hepáticas/metabolismo , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/metabolismo , Metástase Neoplásica , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Fatores de Transcrição/metabolismo
17.
Genes Dev ; 36(7-8): 468-482, 2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-35450884

RESUMO

The nucleosome remodeling and deacetylase (NuRD) complex is one of the central chromatin remodeling complexes that mediates gene repression. NuRD is essential for numerous developmental events, including heart development. Clinical and genetic studies have provided direct evidence for the role of chromodomain helicase DNA-binding protein 4 (CHD4), the catalytic component of NuRD, in congenital heart disease (CHD), including atrial and ventricular septal defects. Furthermore, it has been demonstrated that CHD4 is essential for mammalian cardiomyocyte formation and function. A key unresolved question is how CHD4/NuRD is localized to specific cardiac target genes, as neither CHD4 nor NuRD can directly bind DNA. Here, we coupled a bioinformatics-based approach with mass spectrometry analyses to demonstrate that CHD4 interacts with the core cardiac transcription factors GATA4, NKX2-5, and TBX5 during embryonic heart development. Using transcriptomics and genome-wide occupancy data, we characterized the genomic landscape of GATA4, NKX2-5, and TBX5 repression and defined the direct cardiac gene targets of the GATA4-CHD4, NKX2-5-CHD4, and TBX5-CHD4 complexes. These data were used to identify putative cis-regulatory elements controlled by these complexes. We genetically interrogated two of these silencers in vivo: Acta1 and Myh11 We show that deletion of these silencers leads to inappropriate skeletal and smooth muscle gene misexpression, respectively, in the embryonic heart. These results delineate how CHD4/NuRD is localized to specific cardiac loci and explicates how mutations in the broadly expressed CHD4 protein lead to cardiac-specific disease states.


Assuntos
DNA Helicases , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase , Animais , DNA Helicases/metabolismo , Genes Homeobox , Mamíferos/genética , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/genética , Miócitos Cardíacos/metabolismo , Nucleossomos , Fatores de Transcrição/genética
18.
Arch Toxicol ; 96(6): 1739-1749, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35362730

RESUMO

Epigenetic complex NuRD (nucleosome remodeling and deacetylase) engages in a range of basic cellular processes, including chromatin modification. Changes in the activity of NuRD complex can influence gastric cancer progression. Multivariate logistic regression analyses were used to estimate the association between single-nucleotide polymorphisms (SNPs) and gastric cancer risk. Expression quantitative trait loci (eQTL) analysis was used to analyze the relationship between the genotypes and gene expression levels using data from the genotype tissue expression project (GTEx). Gene expression was calculated using databases from The Cancer Genome Atlas (TCGA) and The Gene Expression Omnibus (GEO). Kaplan-Meier plotter was used to evaluate the association between gene expression and survival. SNP rs11064275 T allele in CHD4, rs892022 A allele and rs2033481 A allele in GATAD2A were found to contribute to the decreased risk of gastric cancer. The increase in the number of favorable alleles of these three SNPs was associated with a lower risk of gastric cancer. rs2033481 and rs892022 were substantially correlated with GATAD2A mRNA expression levels. Meanwhile, we detected that the CHD4 and GATAD2A mRNA expression was increased in gastric cancer tissues compared with the adjacent normal tissues. Furthermore, we found that patients with higher CHD4 or GATAD2A mRNA expression level had more advantageous overall survival. Our findings indicated that genetic variants in NuRD complex subunits encoding genes may be promising predictors of gastric cancer risk.


Assuntos
Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase , Neoplasias Gástricas , Humanos , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/genética , Nucleossomos/genética , RNA Mensageiro , Neoplasias Gástricas/genética
19.
Genet Med ; 24(6): 1283-1296, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35346573

RESUMO

PURPOSE: Common diagnostic next-generation sequencing strategies are not optimized to identify inherited variants in genes associated with dominant neurodevelopmental disorders as causal when the transmitting parent is clinically unaffected, leaving a significant number of cases with neurodevelopmental disorders undiagnosed. METHODS: We characterized 21 families with inherited heterozygous missense or protein-truncating variants in CHD3, a gene in which de novo variants cause Snijders Blok-Campeau syndrome. RESULTS: Computational facial and Human Phenotype Ontology-based comparisons showed that the phenotype of probands with inherited CHD3 variants overlaps with the phenotype previously associated with de novo CHD3 variants, whereas heterozygote parents are mildly or not affected, suggesting variable expressivity. In addition, similarly reduced expression levels of CHD3 protein in cells of an affected proband and of healthy family members with a CHD3 protein-truncating variant suggested that compensation of expression from the wild-type allele is unlikely to be an underlying mechanism. Notably, most inherited CHD3 variants were maternally transmitted. CONCLUSION: Our results point to a significant role of inherited variation in Snijders Blok-Campeau syndrome, a finding that is critical for correct variant interpretation and genetic counseling and warrants further investigation toward understanding the broader contributions of such variation to the landscape of human disease.


Assuntos
DNA Helicases , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase , Transtornos do Neurodesenvolvimento , DNA Helicases/genética , Heterozigoto , Humanos , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/genética , Transtornos do Neurodesenvolvimento/genética , Fenótipo , Síndrome
20.
Genetics ; 221(1)2022 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-35323946

RESUMO

During proteotoxic stress, a pathway known as the heat shock response is induced to maintain protein-folding homeostasis or proteostasis. Previously, we identified the Caenorhabditis elegans GATAD2 ortholog, dcp-66, as a novel regulator of the heat shock response. Here, we extend these findings to show that dcp-66 positively regulates the heat shock response at the cellular, molecular, and organismal levels. As GATAD2 is a subunit of the nucleosome remodeling and deacetylase chromatin remodeling complex, we examined other nucleosome remodeling and deacetylase subunits and found that the let-418 (CHD4) nucleosome repositioning core also regulates the heat shock response. However, let-418 acts as a negative regulator of the heat shock response, in contrast to positive regulation by dcp-66. The divergent effects of these two nucleosome remodeling and deacetylase subunits extend to the regulation of other stress responses including oxidative, genotoxic, and endoplasmic reticulum stress. Furthermore, a transcriptomic approach reveals additional divergently regulated pathways, including innate immunity and embryogenesis. Taken together, this work establishes new insights into the role of nucleosome remodeling and deacetylase subunits in organismal physiology. We incorporate these findings into a molecular model whereby different mechanisms of recruitment to promoters can result in the divergent effects of nucleosome remodeling and deacetylase subunits.


Assuntos
Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase , Nucleossomos , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Montagem e Desmontagem da Cromatina , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/genética , Nucleossomos/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
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