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1.
bioRxiv ; 2024 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-38746145

RESUMO

Signal-induced transcriptional programs regulate critical biological processes through the precise spatiotemporal activation of Immediate Early Genes (IEGs); however, the mechanisms of transcription induction remain poorly understood. By combining an acute depletion system with high resolution genomics approaches to interrogate synchronized, temporal transcription, we reveal that KAP1/TRIM28 is a first responder that fulfills the temporal and heightened transcriptional demand of IEGs. Unexpectedly, acute KAP1 loss triggers an increase in RNA polymerase II elongation kinetics during early stimulation time points. This elongation defect derails the normal progression through the transcriptional cycle during late stimulation time points, ultimately leading to decreased recruitment of the transcription apparatus for re-initiation thereby dampening IEGs transcriptional output. Collectively, KAP1 plays a counterintuitive role by negatively regulating transcription elongation to support full activation across multiple transcription cycles of genes critical for cell physiology and organismal functions.

2.
bioRxiv ; 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38659934

RESUMO

Estradiol (E2) and relaxin (Rln) are steroid and polypeptide hormones, respectively, with important roles in the female reproductive tract, including myometrium. Some actions of Rln, which are mediated by its membrane receptor RXFP1, require or are augmented by E2 signaling through its cognate nuclear steroid receptor, estrogen receptor alpha (ERα). In contrast, other actions of Rln act in opposition to the effects of E2. Here we explore the molecular and genomic mechanisms that underlie the functional interplay between E2 and Rln in the myometrium. We used both ovariectomized female mice and immortalized human myometrial cells expressing wild type or mutant ERα (hTERT-HM-ERα cells). Our results indicate that Rln attenuates the genomic actions and biological effects of estrogen in the myometrium and myometrial cells by reducing phosphorylation ERα on serine 118 (S118). Interestingly, we observed a potent inhibitory effect of Rln on the E2-dependent binding of ERα across the genome. The reduction in ERα binding was associated with changes in the hormone-regulated transcriptome, including a decrease in the E2-dependent expression of neighboring genes. The inhibitory effects of Rln cotreatment on the E2-dependent phosphorylation of ERα required the nuclear dual-specificity phosphatases DUSP1 and DUSP5. Moreover, the inhibitory effects of Rln were reflected in a concomitant inhibition of the E2-dependent contraction of myometrial cells. Collectively, our results identify a pathway that integrates Rln/RXFP1 and E2/ERα signaling, resulting in a convergence of membrane and nuclear signaling pathways to control genomic and biological outcomes.

3.
bioRxiv ; 2023 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-37873085

RESUMO

Mono(ADP-ribosyl)ation (MARylation), a post-translational modification (PTM) of proteins, is emerging as a critical regulator of ribosome function and translation. Herein, we demonstrate that RACK1, a member of the tryptophan-aspartate repeat (WD-repeat) family of proteins and an integral component of the ribosome, is MARylated by the mono(ADP-ribosyl) transferase (MART) PARP14 in ovarian cancer cells. We mapped and confirmed the sites of MARylation, which occur on three acidic residues within blades 4 and 5 of ß-propeller domain of RACK1, a chaperone that shuttles and anchors proteins where needed. Site-specific MARylation of RACK1 is required for stress granule formation and promotes the colocalization of RACK1 to stress granules with key components, such as G3BP1, eIF3η, and 40S ribosomal proteins. In parallel, we observed reduced translation of a subset of mRNAs, including those encoding key cancer regulators (e.g., AKT). Treatment with a PARP14 inhibitor or mutation of the sites of MARylation on RACK1 blocks these outcomes. To re-set the system after prolonged stress and recovery, the ADP-ribosyl hydrolase TARG1 deMARylates RACK1 to dissociate the stress granules and return RACK1 and the 40S ribosomal subunit to the cytoplasm, allowing for a restoration of translation. Collectively, our results highlight the discovery of a PARP14/TARG1-regulated RACK1 MARylation cycle that controls stress granule assembly and disassembly in ovarian cancer cells.

4.
Biol Reprod ; 109(6): 965-981, 2023 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-37694817

RESUMO

The placenta is a dynamic organ that must perform a remarkable variety of functions during its relatively short existence in order to support a developing fetus. These functions include nutrient delivery, gas exchange, waste removal, hormone production, and immune barrier protection. Proper placenta development and function are critical for healthy pregnancy outcomes, but the underlying genomic regulatory events that control this process remain largely unknown. We hypothesized that mapping sites of transcriptional enhancer activity and associated changes in gene expression across gestation in human placenta tissue would identify genomic loci and predicted transcription factor activity related to critical placenta functions. We used a suite of genomic assays [i.e., RNA-sequencing (RNA-seq), Precision run-on-sequencing (PRO-seq), and Chromatin immunoprecipitation-sequencing (ChIP-seq)] and computational pipelines to identify a set of >20 000 enhancers that are active at various time points in gestation. Changes in the activity of these enhancers correlate with changes in gene expression. In addition, some of these enhancers encode risk for adverse pregnancy outcomes. We further show that integrating enhancer activity, transcription factor motif analysis, and transcription factor expression can identify distinct sets of transcription factors predicted to be more active either in early pregnancy or at term. Knockdown of selected identified transcription factors in a trophoblast stem cell culture model altered the expression of key placental marker genes. These observations provide a framework for future mechanistic studies of individual enhancer-transcription factor-target gene interactions and have the potential to inform genetic risk prediction for adverse pregnancy outcomes.


Assuntos
Placenta , Placentação , Humanos , Feminino , Gravidez , Placentação/genética , Placenta/metabolismo , Elementos Facilitadores Genéticos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Regulação da Expressão Gênica
5.
Mol Cancer Res ; 20(11): 1623-1635, 2022 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-35997635

RESUMO

Long noncoding RNAs have been implicated in many of the hallmarks of cancer. Herein, we found that the expression of lncRNA152 (lnc152; a.k.a. DRAIC), which we annotated previously, is highly upregulated in luminal breast cancer (LBC) and downregulated in triple-negative breast cancer (TNBC). Knockdown of lnc152 promotes cell migration and invasion in LBC cell lines. In contrast, ectopic expression of lnc152 inhibits growth, migration, invasion, and angiogenesis in TNBC cell lines. In mice, lnc152 inhibited the growth of TNBC cell xenografts, as well as metastasis of TNBC cells in an intracardiac injection model. Transcriptome analysis of the xenografts indicated that lnc152 downregulates genes controlling angiogenesis. Using pull down assays followed by LC/MS-MS, we identified RBM47, a known tumor suppressor in breast cancer, as a lnc152-interacting protein. The effects of lnc152 in TNBC cells are mediated, in part, by regulating the expression of RBM47. Collectively, our results demonstrate that lnc152 is an angiogenesis-inhibiting tumor suppressor that attenuates the aggressive cancer-related phenotypes found in TNBC. IMPLICATIONS: This study identifies lncRNA152 as an angiogenesis-inhibiting tumor suppressor that attenuates the aggressive cancer-related phenotypes found in TNBC by upregulating the expression of the tumor suppressor RBM47. As such, lncRNA152 may serve as a biomarker to track aggressiveness of breast cancer, as well as therapeutic target for treating TNBC.


Assuntos
RNA Longo não Codificante , Neoplasias de Mama Triplo Negativas , Animais , Humanos , Camundongos , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Genes Supressores de Tumor , Invasividade Neoplásica/genética , Neovascularização Patológica/genética , Proteínas de Ligação a RNA/genética , Neoplasias de Mama Triplo Negativas/patologia , RNA Longo não Codificante/genética
6.
Mol Cancer Res ; 20(8): 1183-1192, 2022 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-35503086

RESUMO

Cervical cancer continues to be a significant cause of cancer-related deaths in women. The most common treatment for cervical cancer involves the use of the drug cisplatin in conjunction with other therapeutics. However, the development of cisplatin resistance in patients can hinder the efficacy of these treatments, so alternatives are needed. In this study, we found that PARP inhibitors (PARPi) could attenuate the growth of cells representing cervical adenocarcinoma and cervical squamous cell carcinoma. Moreover, a combination of PARPi with cisplatin increased cisplatin-mediated cytotoxicity in cervical cancer cells. This was accompanied by a dramatic alteration of the transcriptome. The FOS gene, which encodes the transcription factor Fos, was one of the most highly upregulated genes in the dual treatment condition, leading to increased Fos protein levels, greater Fos binding to chromatin, and the subsequent induction of Fos target genes. Increased expression of Fos was sufficient to hinder cervical cancer growth, as shown by ectopic expression of Fos in cervical cancer cells. Conversely, Fos knockdown enhanced cell growth. Collectively, these results indicate that by inducing FOS expression, PARPi treatment in combination with cisplatin leads to inhibition of cervical cancer proliferation, likely through a Fos-specific gene expression program. IMPLICATIONS: Our observations, which link the gene regulatory effects of PARPi + cisplatin to the growth inhibitory effects of FOS expression in cervical cancer cells, strengthen the rationale for using PARPi with cisplatin as a therapy for cervical cancer.


Assuntos
Antineoplásicos , Cisplatino , Inibidores de Poli(ADP-Ribose) Polimerases , Proteínas Proto-Oncogênicas c-fos , Neoplasias do Colo do Útero , Antineoplásicos/farmacologia , Apoptose , Cisplatino/farmacologia , Resistencia a Medicamentos Antineoplásicos , Feminino , Expressão Gênica , Humanos , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Proteínas Proto-Oncogênicas c-fos/genética , Fatores de Transcrição/genética , Neoplasias do Colo do Útero/tratamento farmacológico , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/patologia
7.
Cell ; 184(17): 4531-4546.e26, 2021 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-34314702

RESUMO

Defects in translation lead to changes in the expression of proteins that can serve as drivers of cancer formation. Here, we show that cytosolic NAD+ synthesis plays an essential role in ovarian cancer by regulating translation and maintaining protein homeostasis. Expression of NMNAT-2, a cytosolic NAD+ synthase, is highly upregulated in ovarian cancers. NMNAT-2 supports the catalytic activity of the mono(ADP-ribosyl) transferase (MART) PARP-16, which mono(ADP-ribosyl)ates (MARylates) ribosomal proteins. Depletion of NMNAT-2 or PARP-16 leads to inhibition of MARylation, increased polysome association and enhanced translation of specific mRNAs, aggregation of their translated protein products, and reduced growth of ovarian cancer cells. Furthermore, MARylation of the ribosomal proteins, such as RPL24 and RPS6, inhibits polysome assembly by stabilizing eIF6 binding to ribosomes. Collectively, our results demonstrate that ribosome MARylation promotes protein homeostasis in cancers by fine-tuning the levels of protein synthesis and preventing toxic protein aggregation.


Assuntos
ADP-Ribosilação , Neoplasias Ovarianas/metabolismo , Biossíntese de Proteínas , Proteostase , Ribossomos/metabolismo , Regiões 3' não Traduzidas/genética , Animais , Sequência de Bases , Linhagem Celular Tumoral , Proliferação de Células , Estresse do Retículo Endoplasmático , Tubas Uterinas/metabolismo , Feminino , Humanos , Camundongos Endogâmicos NOD , Camundongos SCID , NAD/metabolismo , Nicotinamida-Nucleotídeo Adenililtransferase , Conformação de Ácido Nucleico , Neoplasias Ovarianas/patologia , Poli(ADP-Ribose) Polimerases/metabolismo , Polirribossomos/metabolismo , RNA Mensageiro/química , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/metabolismo , Proteínas Ribossômicas/metabolismo
8.
Nat Commun ; 12(1): 3931, 2021 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-34168143

RESUMO

STAT1α is a key transcription factor driving pro-inflammatory responses in macrophages. We found that the interferon gamma (IFNγ)-regulated transcriptional program in macrophages is controlled by ADP-ribosylation (ADPRylation) of STAT1α, a post-translational modification resulting in the site-specific covalent attachment of ADP-ribose moieties. PARP-1, the major nuclear poly(ADP-ribose) polymerase (PARP), supports IFNγ-stimulated enhancer formation by regulating the genome-wide binding and IFNγ-dependent transcriptional activation of STAT1α. It does so by ADPRylating STAT1α on specific residues in its DNA-binding domain (DBD) and transcription activation (TA) domain. ADPRylation of the DBD controls STAT1α binding to its cognate DNA elements, whereas ADPRylation of the TA domain regulates enhancer activation by modulating STAT1α phosphorylation and p300 acetyltransferase activity. Loss of ADPRylation at either site leads to diminished IFNγ-dependent transcription and downstream pro-inflammatory responses. We conclude that PARP-1-mediated ADPRylation of STAT1α drives distinct enhancer activation mechanisms and is a critical regulator of inflammatory responses in macrophages.


Assuntos
ADP-Ribosilação , Interferon gama/metabolismo , Macrófagos/fisiologia , Fator de Transcrição STAT1/genética , Fator de Transcrição STAT1/metabolismo , Animais , Sítios de Ligação , DNA/metabolismo , Elementos Facilitadores Genéticos , Feminino , Técnicas de Silenciamento de Genes , Células HEK293 , Humanos , Inflamação/metabolismo , Inflamação/patologia , Macrófagos/patologia , Masculino , Camundongos Endogâmicos C57BL , Fosforilação , Poli(ADP-Ribose) Polimerase-1/genética , Poli(ADP-Ribose) Polimerase-1/metabolismo , Fator de Transcrição STAT1/química , Ativação Transcricional
9.
Elife ; 102021 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-33475085

RESUMO

PARP-7 (TiPARP) is a mono(ADP-ribosyl) transferase whose protein substrates and biological activities are poorly understood. We observed that PARP7 mRNA levels are lower in ovarian cancer patient samples compared to non-cancerous tissue, but PARP-7 protein nonetheless contributes to several cancer-related biological endpoints in ovarian cancer cells (e.g. growth, migration). Global gene expression analyses in ovarian cancer cells subjected to PARP-7 depletion indicate biological roles for PARP-7 in cell-cell adhesion and gene regulation. To identify the MARylated substrates of PARP-7 in ovarian cancer cells, we developed an NAD+ analog-sensitive approach, which we coupled with mass spectrometry to identify the PARP-7 ADP-ribosylated proteome in ovarian cancer cells, including cell-cell adhesion and cytoskeletal proteins. Specifically, we found that PARP-7 MARylates α-tubulin to promote microtubule instability, which may regulate ovarian cancer cell growth and motility. In sum, we identified an extensive PARP-7 ADP-ribosylated proteome with important roles in cancer-related cellular phenotypes.


Cancer is a complex illness where changes inside healthy cells causes them to grow and reproduce rapidly. Specialized proteins called enzymes ­ which regulate chemical reactions in the cell ­ often help cancer develop and spread through the body. One such enzyme called PARP-7 labels other proteins by attaching a chemical group which changes their behavior. However, it was unknown which proteins PARP-7 modifies and how this tag alters the actions of these proteins. To investigate this, Parsons, Challa, Gibson et al. developed a method to find and identify the proteins labelled by PARP-7 in ovarian cancer cells taken from patients and cultured in the laboratory. This revealed that PARP-7 labels hundreds of different proteins, including adhesion proteins which affect the connections between cells and cytoskeletal proteins which regulate a cell's shape and how it moves. One of the cytoskeletal proteins modified by PARP-7 is α-tubulin, which joins together with other tubulins to form long, tube-like structures known as microtubules. Parsons et al. found that when α-tubulin is labelled by PARP-7, it creates unstable microtubules that alter how the cancer cells grow and move. They discovered that depleting PARP-7 or mutating the sites where it modifies α-tubulin increased the stability of microtubules and slowed the growth of ovarian cancer cells. Ovarian cancer is the fifth leading cause of cancer-related deaths among women in the United States. A new drug which suppresses the activity of PARP-7 has recently been developed, and this drug could potentially be used to treat ovarian cancer patients with high levels of PARP-7. Clinical trials are ongoing to see how this drug affects the behavior of cancer cells in patients.


Assuntos
ADP-Ribosilação , Microtúbulos/metabolismo , Proteínas de Transporte de Nucleosídeos/genética , Linhagem Celular Tumoral , Feminino , Humanos , Masculino , Proteínas de Transporte de Nucleosídeos/metabolismo , Neoplasias Ovarianas/metabolismo
10.
Mol Cell Endocrinol ; 506: 110746, 2020 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-32035111

RESUMO

Estrogen-responsive breast cancer cells exhibit both basal and estrogen-regulated transcriptional programs, which lead to the transcription of many different transcription units (i.e., genes), including those that produce coding and non-coding sense (e.g., mRNA, lncRNA) and antisense (i.e., asRNA) transcripts. We have previously characterized the global basal and estrogen-regulated transcriptomes in estrogen receptor alpha (ERα)-positive MCF-7 breast cancer cells. Herein, we have mined genomic data to define three classes of antisense transcription in MCF-7 cells based on where their antisense transcription termination sites reside relative to their cognate sense mRNA and lncRNA genes. These three classes differ in their response to estrogen treatment, the enrichment of a number of genomic features associated with active promoters (H3K4me3, RNA polymerase II, open chromatin architecture), and the biological functions of their cognate sense genes as analyzed by DAVID gene ontology. We further characterized two estrogen-regulated antisense transcripts arising from the MYC gene in MCF-7 cells, showing that these antisense transcripts are 5'-capped, 3'-polyadenylated, and localized to different compartments of the cell. Together, our analyses have revealed distinct classes of antisense transcription correlated to different biological processes and response to estrogen stimulation, uncovering another layer of hormone-regulated gene regulation.


Assuntos
Adenocarcinoma/genética , Neoplasias da Mama/genética , DNA Antissenso/genética , Estrogênios/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Adenocarcinoma/patologia , Metabolismo Basal/efeitos dos fármacos , Metabolismo Basal/genética , Neoplasias da Mama/patologia , DNA Antissenso/efeitos dos fármacos , Feminino , Perfilação da Expressão Gênica , Humanos , Células MCF-7 , Análise em Microsséries , Regiões Promotoras Genéticas/efeitos dos fármacos , Regiões Promotoras Genéticas/genética , RNA Antissenso/efeitos dos fármacos , RNA Antissenso/genética , RNA Antissenso/metabolismo , Transcrição Gênica/efeitos dos fármacos , Transcriptoma/efeitos dos fármacos
11.
Biol Reprod ; 102(2): 327-338, 2020 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-31511857

RESUMO

The ovarian hormones estrogen and progesterone orchestrate the transcriptional programs required to direct functions of the uterus for initiation and maintenance of pregnancy. Estrogen, acting via estrogen receptor alpha, regulates gene expression by activating and repressing distinct genes involved in signaling pathways that regulate cellular and physiological responses including cell division, water influx, and immune cell recruitment. Historically, these transcriptional responses have been postulated to reflect a biphasic physiological response. In this study, we explored the transcriptional responses of the ovariectomized mouse uterus to 17ß-estradiol (E2) by RNA-seq to obtain global expression profiles of protein-coding transcripts (mRNAs) and long noncoding RNAs (lncRNAs) following 0.5, 1, 2, and 6 hours of treatment. The E2-regulated mRNA and lncRNA expression profiles in the mouse uterus indicate an association between lncRNAs and mRNAs that regulate E2-driven pathways and reproductive phenotypes in the mouse. The transient E2-regulated transcriptome is reflected in the time-dependent shifting of biological processes regulated in the uterus in response to E2. Moreover, high expression of some conserved lncRNAs that are E2 regulated in the mouse uterus are predictive of low overall survival in endometrial carcinoma patients (e.g., H19, KCNQ1OT1, MIR17HG, and FTX). Collectively, this study (1) describes a genomic approach for identifying E2-regulated lncRNAs that may serve critical function in the uterus and (2) provides new insights into our understanding of the regulation of hormone-regulated transcriptional responses with implications in pregnancy and endometrial pathologies.


Assuntos
Estradiol/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , RNA Longo não Codificante/metabolismo , RNA Mensageiro/metabolismo , Transcriptoma/efeitos dos fármacos , Útero/efeitos dos fármacos , Animais , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Neoplasias da Mama/mortalidade , Bases de Dados Genéticas , Feminino , Ontologia Genética , Neoplasias dos Genitais Femininos/genética , Neoplasias dos Genitais Femininos/metabolismo , Neoplasias dos Genitais Femininos/mortalidade , Humanos , Camundongos , Ovariectomia , RNA Longo não Codificante/genética , RNA Mensageiro/genética , Taxa de Sobrevida , Útero/metabolismo
12.
Mol Cancer Ther ; 19(1): 282-291, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31594824

RESUMO

Inhibitors of nuclear PARP enzymes (e.g., PARP-1) have improved clinical outcomes in ovarian cancer, especially in patients with BRCA1/2 gene mutations or additional homologous recombination (HR) DNA repair pathway deficiencies. These defects serve as biomarkers for response to PARP inhibitors (PARPi). We sought to identify an additional biomarker that could predict responses to both conventional chemotherapy and PARPi in ovarian cancers. We focused on cellular ADP-ribosylation (ADPRylation), which is catalyzed by PARP enzymes and detected by detection reagents we developed previously. We determined molecular phenotypes of 34 high-grade serous ovarian cancers and associated them with clinical outcomes. We used the levels and patterns of ADPRylation and PARP-1 to distribute ovarian cancers into distinct molecular phenotypes, which exhibit dramatically different gene expression profiles. In addition, the levels and patterns of ADPRylation, PARP-1 protein, and gene expression correlated with clinical outcomes in response to platinum-based chemotherapy, with cancers exhibiting the highest levels of ADPRylation having the best outcomes independent of BRCA1/2 status. Finally, in cell culture-based assays using patient-derived ovarian cancer cell lines, ADPRylation levels correlated with sensitivity to the PARPi, Olaparib, with cell lines exhibiting high levels of ADPRylation having greater sensitivity to Olaparib. Collectively, our study demonstrates that ovarian cancers exhibit a wide range of ADPRylation levels, which correlate with therapeutic responses and clinical outcomes. These results suggest ADPRylation may be a useful biomarker for PARPi sensitivity in ovarian cancers, independent of BRCA1/2 or homologous recombination deficiency status.


Assuntos
ADP-Ribosilação/genética , Expressão Gênica/genética , Neoplasias Ovarianas/genética , Adulto , Idoso , Linhagem Celular Tumoral , Feminino , Humanos , Pessoa de Meia-Idade
13.
Science ; 360(6389)2018 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-29748257

RESUMO

NAD+ (nicotinamide adenine dinucleotide in its oxidized state) is an essential molecule for a variety of physiological processes. It is synthesized in distinct subcellular compartments by three different synthases (NMNAT-1, -2, and -3). We found that compartmentalized NAD+ synthesis by NMNATs integrates glucose metabolism and adipogenic transcription during adipocyte differentiation. Adipogenic signaling rapidly induces cytoplasmic NMNAT-2, which competes with nuclear NMNAT-1 for the common substrate, nicotinamide mononucleotide, leading to a precipitous reduction in nuclear NAD+ levels. This inhibits the catalytic activity of poly[adenosine diphosphate (ADP)-ribose] polymerase-1 (PARP-1), a NAD+-dependent enzyme that represses adipogenic transcription by ADP-ribosylating the adipogenic transcription factor C/EBPß. Reversal of PARP-1-mediated repression by NMNAT-2-mediated nuclear NAD+ depletion in response to adipogenic signals drives adipogenesis. Thus, compartmentalized NAD+ synthesis functions as an integrator of cellular metabolism and signal-dependent transcriptional programs.


Assuntos
Adipócitos/citologia , Adipogenia/genética , NAD/biossíntese , Nicotinamida-Nucleotídeo Adenililtransferase/metabolismo , Transcrição Gênica , Adipócitos/metabolismo , Animais , Proteína beta Intensificadora de Ligação a CCAAT , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Citoplasma/metabolismo , Glucose/metabolismo , Humanos , Camundongos , NAD/genética , Células NIH 3T3 , Poli(ADP-Ribose) Polimerase-1/metabolismo , Especificidade por Substrato
14.
Biol Reprod ; 98(3): 408-421, 2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29281003

RESUMO

With half a million babies born preterm each year in the USA and about 15 million worldwide, preterm birth (PTB) remains a global health issue. Preterm birth is a primary cause of infant morbidity and mortality and can impact lives long past infancy. The fact that there are numerous, and many currently unidentified, etiologies of PTB has hindered development of tools for risk evaluation and preventative therapies. Infection is estimated to be involved in nearly 40% of PTBs of known etiology; therefore, understanding how infection-mediated inflammation alters the cervical milieu and leads to preterm tissue biomechanical changes are questions of interest. Using RNA-seq, we identified enrichment of components involved in inflammasome activation and unique proteases in the mouse cervix during lipopolysaccharide (LPS)-mediated PTB and not physiologically at term before labor. Despite transcriptional induction of inflammasome components, there was no evidence of functional activation based on assessment of mature IL1B and IL18 proteins. The increased transcription of proteases that target both elastic fibers and collagen and concentration of myeloid-derived cells capable of protease synthesis in the cervical stroma support the structural disruption of elastic fibers as a functional output of protease activity. The recent demonstration that elastic fibers contribute to the biomechanical function of the pregnant cervix suggests their protease-induced disruption in the infection model of LPS-mediated PTB and may contribute to premature loss of mechanical competency and preterm delivery. Collectively, the transcriptomics and ultrastructural data provide new insights into the distinct mechanisms of premature cervical remodeling in response to infection.


Assuntos
Colo do Útero/metabolismo , Lipopolissacarídeos , Nascimento Prematuro/metabolismo , Transcriptoma , Animais , Feminino , Interleucina-18/metabolismo , Interleucina-1beta/metabolismo , Camundongos , Nascimento Prematuro/induzido quimicamente , Nascimento Prematuro/genética
15.
Mol Cell ; 65(2): 260-271, 2017 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-28107648

RESUMO

Poly(ADP-ribosyl)ation (PARylation) is a post-translational modification of proteins mediated by PARP family members, such as PARP-1. Although PARylation has been studied extensively, few examples of definitive biological roles for site-specific PARylation have been reported. Here we show that C/EBPß, a key pro-adipogenic transcription factor, is PARylated by PARP-1 on three amino acids in a conserved regulatory domain. PARylation at these sites inhibits C/EBPß's DNA binding and transcriptional activities and attenuates adipogenesis in various genetic and cell-based models. Interestingly, PARP-1 catalytic activity drops precipitously during the first 48 hr of differentiation, corresponding to a release of C/EBPß from PARylation-mediated inhibition. This promotes the binding of C/EBPß at enhancers controlling the expression of adipogenic target genes and continued differentiation. Depletion or chemical inhibition of PARP-1, or mutation of the PARylation sites on C/EBPß, enhances these early adipogenic events. Collectively, our results provide a clear example of how site-specific PARylation drives biological outcomes.


Assuntos
Adipócitos/enzimologia , Adipogenia , Proteína beta Intensificadora de Ligação a CCAAT/metabolismo , Células-Tronco Embrionárias/enzimologia , Poli(ADP-Ribose) Polimerase-1/metabolismo , Poli Adenosina Difosfato Ribose/metabolismo , Processamento de Proteína Pós-Traducional , Transcrição Gênica , Células 3T3-L1 , Adipócitos/efeitos dos fármacos , Adipogenia/efeitos dos fármacos , Animais , Sítios de Ligação , Proteína beta Intensificadora de Ligação a CCAAT/genética , DNA/genética , DNA/metabolismo , Células-Tronco Embrionárias/efeitos dos fármacos , Genótipo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mutação , Células NIH 3T3 , Fenótipo , Poli(ADP-Ribose) Polimerase-1/antagonistas & inibidores , Poli(ADP-Ribose) Polimerase-1/deficiência , Poli(ADP-Ribose) Polimerase-1/genética , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Ligação Proteica , Domínios Proteicos , Interferência de RNA , Transdução de Sinais , Fatores de Tempo , Transcrição Gênica/efeitos dos fármacos , Ativação Transcricional , Transfecção
16.
Nat Commun ; 7: 13796, 2016 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-27982029

RESUMO

Some polypeptide N-acetyl-galactosaminyltransferases (GALNTs) are associated with cancer, but their function in organ-specific metastasis remains unclear. Here, we report that GALNT14 promotes breast cancer metastasis to the lung by enhancing the initiation of metastatic colonies as well as their subsequent growth into overt metastases. Our results suggest that GALNT14 augments the self-renewal properties of breast cancer cells (BCCs). Furthermore, GALNT14 overcomes the inhibitory effect of lung-derived bone morphogenetic proteins (BMPs) on self-renewal and therefore facilitates metastasis initiation within the lung microenvironment. In addition, GALNT14 supports continuous growth of BCCs in the lung by not only inducing macrophage infiltration but also exploiting macrophage-derived fibroblast growth factors (FGFs). Finally, we identify KRAS-PI3K-c-JUN signalling as an upstream pathway that accounts for the elevated expression of GALNT14 in lung-metastatic BCCs. Collectively, our findings uncover an unprecedented role for GALNT14 in the pulmonary metastasis of breast cancer and elucidate the underlying molecular mechanisms.


Assuntos
Neoplasias da Mama/patologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Neoplasias Pulmonares/secundário , N-Acetilgalactosaminiltransferases/metabolismo , Animais , Benzamidas/farmacologia , Receptores de Proteínas Morfogenéticas Ósseas/antagonistas & inibidores , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Diaminas/farmacologia , Dioxóis/farmacologia , Feminino , Glicosilação , Fatores de Troca do Nucleotídeo Guanina , Humanos , Pulmão/patologia , Pulmão/fisiologia , Camundongos , Camundongos Nus , Mutação , N-Acetilgalactosaminiltransferases/genética , Neoplasias Experimentais/patologia , Pirazóis/farmacologia , Quinolinas/farmacologia , Receptores Notch/antagonistas & inibidores , Receptores de Fatores de Crescimento Transformadores beta/antagonistas & inibidores , Tiazóis/farmacologia , Polipeptídeo N-Acetilgalactosaminiltransferase
17.
Sci Rep ; 6: 20179, 2016 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-26888216

RESUMO

Histone acetylation plays a pivotal role in transcriptional regulation, and ATP-dependent nucleosome remodeling activity is required for optimal transcription from chromatin. While these two activities have been well characterized, how they are coordinated remains to be determined. We discovered ATP-dependent histone H2A acetylation activity in Drosophila nuclear extracts. This activity was column purified and demonstrated to be composed of the enzymatic activities of CREB-binding protein (CBP) and SMARCAD1, which belongs to the Etl1 subfamily of the Snf2 family of helicase-related proteins. SMARCAD1 enhanced acetylation by CBP of H2A K5 and K8 in nucleosomes in an ATP-dependent fashion. Expression array analysis of S2 cells having ectopically expressed SMARCAD1 revealed up-regulated genes. Using native genome templates of these up-regulated genes, we found that SMARCAD1 activates their transcription in vitro. Knockdown analysis of SMARCAD1 and CBP indicated overlapping gene control, and ChIP-seq analysis of these commonly controlled genes showed that CBP is recruited to the promoter prior to SMARCAD1. Moreover, Drosophila genetic experiments demonstrated interaction between SMARCAD1/Etl1 and CBP/nej during development. The interplay between the remodeling activity of SMARCAD1 and histone acetylation by CBP sheds light on the function of chromatin and the genome-integrity network.


Assuntos
DNA Helicases/metabolismo , Proteínas de Drosophila/metabolismo , Histonas/metabolismo , Processamento de Proteína Pós-Traducional/fisiologia , Transcrição Gênica/fisiologia , Fatores de Transcrição de p300-CBP/metabolismo , Acetilação , Animais , Linhagem Celular , DNA Helicases/genética , Proteínas de Drosophila/genética , Drosophila melanogaster , Histonas/genética , Fatores de Transcrição de p300-CBP/genética
18.
Indian J Clin Biochem ; 27(1): 74-82, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23277716

RESUMO

To analyse the association of high sensitivity C-reactive (hsCRP) protein levels and -717A/G single nucleotide polymorphism of CRP with acute myocardial infarction (AMI) in the Indian population. Study population included 100 MI cases wherein 32 patients had experienced previous MI (MI-Group-1), 68 MI cases were recruited at presentation (MI-Group-2) and equal number of age and gender matched healthy individuals. hsCRP levels were determined by ELISA and genotyping of -717A/G was carried out by polymerase chain reaction-based restriction digestion method. The -717A/G genotypes did not influence hsCRP level and their distribution did not differ between groups. However, in the present study hsCRP demonstrated significant correlation with BMI in controls of both the genders and with triglycerides in females of AMI at presentation who otherwise are with low risk profile. Identifying traditional risk factors associated with inflammation may help in controlling the acute event.

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