Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 31
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
BMC Biol ; 18(1): 32, 2020 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-32209106

RESUMO

BACKGROUND: Nuclear factor-κB (NF-κB) plays a prominent role in promoting inflammation and resistance to DNA damaging therapy. We searched for proteins that modulate the NF-κB response as a prerequisite to identifying novel factors that affect sensitivity to DNA damaging chemotherapy. RESULTS: Using streptavidin-agarose pull-down, we identified the DExD/H-box RNA helicase, DDX39B, as a factor that differentially interacts with κB DNA probes. Subsequently, using both RNA interference and CRISPR/Cas9 technology, we demonstrated that DDX39B inhibits NF-κB activity by a general mechanism involving inhibition of p65 phosphorylation. Mechanistically, DDX39B mediates this effect by interacting with the pattern recognition receptor (PRR), LGP2, a pathway that required the cellular response to cytoplasmic double-stranded RNA (dsRNA). From a functional standpoint, loss of DDX39B promoted resistance to alkylating chemotherapy in glioblastoma cells. Further examination of DDX39B demonstrated that its protein abundance was regulated by site-specific sumoylation that promoted its poly-ubiquitination and degradation. These post-translational modifications required the presence of the SUMO E3 ligase, PIASx-ß. Finally, genome-wide analysis demonstrated that despite the link to the PRR system, DDX39B did not generally inhibit interferon-stimulated gene expression, but rather acted to attenuate expression of factors associated with the extracellular matrix, cellular migration, and angiogenesis. CONCLUSIONS: These results identify DDX39B, a factor with known functions in mRNA splicing and nuclear export, as an RNA-binding protein that blocks a subset of the inflammatory response. While these findings identify a pathway by which DDX39B promotes sensitization to DNA damaging therapy, the data also reveal a mechanism by which this helicase may act to mitigate autoimmune disease.


Assuntos
RNA Helicases DEAD-box/genética , NF-kappa B/metabolismo , Receptores de Reconhecimento de Padrão/genética , Transdução de Sinais , Alquilação , Animais , RNA Helicases DEAD-box/metabolismo , Sondas de DNA , Tratamento Farmacológico , Humanos , Camundongos , Receptores de Reconhecimento de Padrão/metabolismo
2.
Gastroenterology ; 155(1): 144-155, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29621481

RESUMO

BACKGROUND & AIMS: Inflammation affects regeneration of the intestinal epithelia; long noncoding RNAs (lncRNAs) regulate cell functions, such as proliferation, differentiation, and migration. We investigated the mechanisms by which the lncRNA H19, imprinted maternally expressed transcript (H19) regulates regeneration of intestinal epithelium using cell cultures and mouse models of inflammation. METHODS: We performed RNA-sequencing transcriptome analyses of intestinal tissues from mice with lipopolysaccharide (LPS)-induced sepsis to identify lncRNAs associated with inflammation; findings were confirmed by quantitative real-time polymerase chain reaction and in situ hybridization analyses of intestinal tissues from mice with sepsis or dextran sulfate sodium (DSS)-induced mucosal wound healing and patients with ulcerative colitis compared to healthy individuals (controls). We screened cytokines for their ability to induce expression of H19 in HT-29 cells and intestinal epithelial cells (IECs), and confirmed findings in crypt epithelial organoids derived from mouse small intestine. IECs were incubated with different signal transduction inhibitors and effects on H19 lncRNA levels were measured. We assessed intestinal epithelial proliferation or regeneration in H19ΔEx1/+ mice given LPS or DSS vs wild-type littermates (control mice). H19 was overexpressed in IECs using lentiviral vectors and cell proliferation was measured. We performed RNA antisense purification, RNA immunoprecipitation, and luciferase reporter assays to study functions of H19 in IECs. RESULTS: In RNA-sequencing transcriptome analysis of lncRNA expression in intestinal tissues from mice, we found that levels of H19 lncRNA changed significantly with LPS exposure. Levels of H19 lncRNA increased in intestinal tissues of patients with ulcerative colitis, mice with LPS-induced and polymicrobial sepsis, or mice with DSS-induced colitis, compared with controls. Increased H19 lncRNA localized to epithelial cells in the intestine, regardless of Lgr5 messenger RNA expression. Exposure of IECs to interleukin 22 (IL22) increased levels of H19 lncRNA with time and dose, which required STAT3 and protein kinase A activity. IL22 induced expression of H19 in mouse intestinal epithelial organoids within 6 hours. Exposure to IL22 increased growth of intestinal epithelial organoids derived from control mice, but not H19ΔEx1/+ mice. Overexpression of H19 in HT-29 cells increased their proliferation. Intestinal mucosa healed more slowly after withdrawal of DSS from H19ΔEx1/+ mice vs control mice. Crypt epithelial cells from H19ΔEx1/+ mice proliferated more slowly than those from control mice after exposure to LPS. H19 lncRNA bound to p53 and microRNAs that inhibit cell proliferation, including microRNA 34a and let-7; H19 lncRNA binding blocked their function, leading to increased expression of genes that promote regeneration of the epithelium. CONCLUSIONS: The level of lncRNA H19 is increased in inflamed intestinal tissues from mice and patients. The inflammatory cytokine IL22 induces expression of H19 in IECs, which is required for intestinal epithelial proliferation and mucosal healing. H19 lncRNA appears to inhibit p53 protein and microRNA 34a and let-7 to promote proliferation of IECs and epithelial regeneration.


Assuntos
Colite Ulcerativa/imunologia , Regulação da Expressão Gênica/imunologia , Interleucinas/imunologia , Mucosa Intestinal/imunologia , RNA Longo não Codificante/genética , Regeneração/fisiologia , Sepse/imunologia , Animais , Estudos de Casos e Controles , Proliferação de Células , Modelos Animais de Doenças , Células Epiteliais , Perfilação da Expressão Gênica , Células HT29 , Humanos , Inflamação , Mucosa Intestinal/fisiologia , Camundongos , RNA Longo não Codificante/imunologia , Reação em Cadeia da Polimerase em Tempo Real , Interleucina 22
3.
Genome Res ; 22(2): 322-31, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22179855

RESUMO

Androgen receptor (AR) is a hormone-activated transcription factor that plays important roles in prostate development and function, as well as malignant transformation. The downstream pathways of AR, however, are incompletely understood. AR has been primarily known as a transcriptional activator inducing prostate-specific gene expression. Through integrative analysis of genome-wide AR occupancy and androgen-regulated gene expression, here we report AR as a globally acting transcriptional repressor. This repression is mediated by androgen-responsive elements (ARE) and dictated by Polycomb group protein EZH2 and repressive chromatin remodeling. In embryonic stem cells, AR-repressed genes are occupied by EZH2 and harbor bivalent H3K4me3 and H3K27me3 modifications that are characteristic of differentiation regulators, the silencing of which maintains the undifferentiated state. Concordantly, these genes are silenced in castration-resistant prostate cancer rendering a stem cell-like lack of differentiation and tumor progression. Collectively, our data reveal an unexpected role of AR as a transcriptional repressor inhibiting non-prostatic differentiation and, upon excessive signaling, resulting in cancerous dedifferentiation.


Assuntos
Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Receptores Androgênicos/metabolismo , Proteínas Repressoras/metabolismo , Sequência de Bases , Linhagem Celular Tumoral , Análise por Conglomerados , Proteínas de Ligação a DNA/metabolismo , Células-Tronco Embrionárias/metabolismo , Proteína Potenciadora do Homólogo 2 de Zeste , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Motivos de Nucleotídeos , Orquiectomia , Complexo Repressor Polycomb 2 , Proteínas do Grupo Polycomb , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , Ligação Proteica , Elementos de Resposta , Transdução de Sinais , Fatores de Transcrição/metabolismo , Ativação Transcricional
4.
Mol Biol Rep ; 40(11): 6233-44, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24091942

RESUMO

Retinoid-X-receptor (RXR) plays an essential role in the molting process of decapod crustaceans, by forming a heterodimeric complex with the ecdysteroid receptor. However, its role during female reproduction, especially in the process of ovarian maturation, has not been characterized. To get an insight into the molecular events governing the process of ovarian maturation in shrimps, the full-length cDNA of RXR from Metapenaeus ensis was cloned by extension of truncated cDNA by using the RACE technique. The open reading frame of MeRXR encodes a 410 amino acid protein with a deduced molecular weight of 44.8 kDa, and putative pI of 6.64, which roughly matched our observation from 2DE gel. Phylogenetic analysis showed that MeRXR has high similarity to RXR of Penaeus chinensis and P. japonicus. RT-PCR revealed that MeRXR was universally expressed in all tissues investigated. The variation in MeRXR mRNA expression pattern during ovarian maturation was further analyzed by real-time PCR. In contrast to the decrease in MeRXR at protein level with ovarian maturation, MeRXR mRNA level was low in pre-vitellogenic and mid-vitellogenic ovaries, and increased significantly from mid-vitellogenic to late-vitellogenic stages. This result suggests that MeRXR transcripts in the mature ovary probably act as maternal messages for regulating early molting events during embryonic development.


Assuntos
Clonagem Molecular , Expressão Gênica , Ovário/metabolismo , Penaeidae/genética , Penaeidae/metabolismo , Receptores X de Retinoides/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , DNA Complementar/química , DNA Complementar/genética , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Dados de Sequência Molecular , Especificidade de Órgãos/genética , Ovário/efeitos dos fármacos , Filogenia , Receptores X de Retinoides/metabolismo , Retinoides/farmacologia , Alinhamento de Sequência , Transcriptoma
5.
Nat Commun ; 14(1): 5586, 2023 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-37696809

RESUMO

A large spread in model estimates of the equilibrium climate sensitivity (ECS), defined as the global mean near-surface air-temperature increase following a doubling of atmospheric CO2 concentration, leaves us greatly disadvantaged in guiding policy-making for climate change adaptation and mitigation. In this study, we show that the projected ECS in the latest generation of climate models is highly related to seasonal variations of extratropical low-cloud fraction (LCF) in historical simulations. Marked reduction of extratropical LCF from winter to summer is found in models with ECS > 4.75 K, in accordance with the significant reduction of extratropical LCF under a warming climate in these models. In contrast, a pronounced seasonal cycle of extratropical LCF, as supported by satellite observations, is largely absent in models with ECS < 3.3 K. The distinct seasonality in extratropical LCF in climate models is ascribed to their different prevailing cloud regimes governing the extratropical LCF variability.

6.
Cell Death Differ ; 30(5): 1166-1183, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36813924

RESUMO

Peptides/small proteins, encoded by noncanonical open reading frames (ORF) of previously claimed non-coding RNAs, have recently been recognized possessing important biological functions, but largely uncharacterized. 1p36 is an important tumor suppressor gene (TSG) locus frequently deleted in multiple cancers, with critical TSGs like TP73, PRDM16, and CHD5 already validated. Our CpG methylome analysis identified a silenced 1p36.3 gene KIAA0495, previously thought coding long non-coding RNA. We found that the open reading frame 2 of KIAA0495 is actually protein-coding and translating, encoding a small protein SP0495. KIAA0495 transcript is broadly expressed in multiple normal tissues, but frequently silenced by promoter CpG methylation in multiple tumor cell lines and primary tumors including colorectal, esophageal and breast cancers. Its downregulation/methylation is associated with poor survival of cancer patients. SP0495 induces tumor cell apoptosis, cell cycle arrest, senescence and autophagy, and inhibits tumor cell growth in vitro and in vivo. Mechanistically, SP0495 binds to phosphoinositides (PtdIns(3)P, PtdIns(3,5)P2) as a lipid-binding protein, inhibits AKT phosphorylation and its downstream signaling, and further represses oncogenic AKT/mTOR, NF-κB, and Wnt/ß-catenin signaling. SP0495 also regulates the stability of autophagy regulators BECN1 and SQSTM1/p62 through modulating phosphoinositides turnover and autophagic/proteasomal degradation. Thus, we discovered and validated a 1p36.3 small protein SP0495, functioning as a novel tumor suppressor regulating AKT signaling activation and autophagy as a phosphoinositide-binding protein, being frequently inactivated by promoter methylation in multiple tumors as a potential biomarker.


Assuntos
RNA Longo não Codificante , Humanos , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fosforilação , Metilação de DNA/genética , Proteínas de Transporte/metabolismo , Genes Supressores de Tumor , Proliferação de Células/genética , Linhagem Celular Tumoral , Via de Sinalização Wnt , Autofagia/genética , Regulação Neoplásica da Expressão Gênica , DNA Helicases/metabolismo , Proteínas do Tecido Nervoso/metabolismo
7.
ACS Synth Biol ; 11(1): 92-102, 2022 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-34927418

RESUMO

Promoters are one of the most critical regulatory elements controlling metabolic pathways. However, the fast and accurate prediction of promoter strength remains challenging, leading to time- and labor-consuming promoter construction and characterization processes. This dilemma is caused by the lack of a big promoter library that has gradient strengths, broad dynamic ranges, and clear sequence profiles that can be used to train an artificial intelligence model of promoter strength prediction. To overcome this challenge, we constructed and characterized a mutant library of Trc promoters (Ptrc) using 83 rounds of mutation-construction-screening-characterization engineering cycles. After excluding invalid mutation sites, we established a synthetic promoter library that consisted of 3665 different variants, displaying an intensity range of more than two orders of magnitude. The strongest variant was ∼69-fold stronger than the original Ptrc and 1.52-fold stronger than a 1 mM isopropyl-ß-d-thiogalactoside-driven PT7 promoter, with an ∼454-fold difference between the strongest and weakest expression levels. Using this synthetic promoter library, different machine learning models were built and optimized to explore the relationships between promoter sequences and transcriptional strength. Finally, our XgBoost model exhibited optimal performance, and we utilized this approach to precisely predict the strength of artificially designed promoter sequences (R2 = 0.88, mean absolute error = 0.15, and Pearson correlation coefficient = 0.94). Our work provides a powerful platform that enables the predictable tuning of promoters to achieve optimal transcriptional strength.


Assuntos
Inteligência Artificial , Redes e Vias Metabólicas , Biblioteca Gênica , Aprendizado de Máquina , Regiões Promotoras Genéticas/genética
8.
Cell Biosci ; 12(1): 43, 2022 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-35379326

RESUMO

BACKGROUND: Nuclear factor-κB is a multi-subunit transcription factor that plays a central role in cellular senescence. We previously reported that an increase in the p52 subunit is seen in senescent cells and aged tissue. In the current work, we examined the mechanism by which p52 is activated and whether the increase in p52 promotes senescence. RESULTS: Using both primary mouse embryonic fibroblasts (MEFs) and WI-38 human lung fibroblasts, we examined cells after serial passage and following prolonged culture. An increase in p52 was found in the nucleus relative to pre-senescent cells. The increase in p52 protein was not reflected by an increase in NFKB2 mRNA or by an increase in the abundance of upstream activating kinases, IKKα and NIK. To examine whether p52 promotes senescence, we over-expressed mature p52 in primary MEFs. Significantly more senescence was seen compared to control, a finding not seen with p52 mutated at critical DNA binding residues. In addition, blocking p52 nuclear translocation with the peptide inhibitor, SN52, decreased ß-galactosidase (ß-gal) formation. Subsequent filtration studies demonstrated that proteins in conditioned media (CM) were necessary for the increase in p52 and mass spectrometry identified S100A4 and cyclophilin A (CYPA) as potential factors in CM necessary for induction of p52. The requirement of these proteins in CM for induction of p52 was confirmed using depletion and supplementation studies. In addition, we found that activation of STAT3 signaling was required for the increase in p52. Finally, genome wide ChIP-sequencing analysis confirmed that there is an increase in p52 chromatin enrichment with senescence and identified several downstream factors whose expression is regulated by increased p52 binding. CONCLUSIONS: These results demonstrate that p52 nuclear translocation is increased in senescent cells by factors in conditioned media and that mature p52 induces cellular senescence. The data are consistent with the prior observation that p52 is elevated in aged tissue and support the hypothesis that p52 contributes to organismal aging.

9.
Front Immunol ; 12: 679482, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34177923

RESUMO

Infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes COVID-19, a disease that involves significant lung tissue damage. How SARS-CoV-2 infection leads to lung injury remains elusive. The open reading frame 8 (ORF8) protein of SARS-CoV-2 (ORF8SARS-CoV-2) is a unique accessory protein, yet little is known about its cellular function. We examined the cellular distribution of ORF8SARS-CoV-2 and its role in the regulation of human lung epithelial cell proliferation and antiviral immunity. Using live imaging and immunofluorescent staining analyses, we found that ectopically expressed ORF8SARS-CoV-2 forms aggregates in the cytosol and nuclear compartments of lung epithelial cells. Using in silico bioinformatic analysis, we found that ORF8SARS-CoV-2 possesses an intrinsic aggregation characteristic at its N-terminal residues 1-18. Cell culture did not reveal any effects of ORF8SARS-CoV-2 expression on lung epithelial cell proliferation and cell cycle progression, suggesting that ORF8SARS-CoV-2 aggregates do not affect these cellular processes. Interestingly, ectopic expression of ORF8SARS-CoV-2 in lung epithelial cells suppressed basal expression of several antiviral molecules, including DHX58, ZBP1, MX1, and MX2. In addition, expression of ORF8SARS-CoV-2 attenuated the induction of antiviral molecules by IFNγ but not by IFNß in lung epithelial cells. Taken together, ORF8SARS-CoV-2 is a unique viral accessory protein that forms aggregates when expressing in lung epithelial cells. It potently inhibits the expression of lung cellular anti-viral proteins at baseline and in response to IFNγ in lung epithelial cells, which may facilitate SARS-CoV-2 escape from the host antiviral innate immune response during early viral infection. In addition, it seems that formation of ORF8SARS-CoV-2 aggregate is independent from the viral infection. Thus, it would be interesting to examine whether any COVID-19 patients exhibit persistent ORF8 SARS-CoV-2 expression after recovering from SARS-CoV-2 infection. If so, the pathogenic effect of prolonged ORF8SARS-CoV-2 expression and its association with post-COVID symptoms warrant investigation in the future.


Assuntos
COVID-19/imunologia , Pulmão/patologia , Mucosa Respiratória/fisiologia , SARS-CoV-2/fisiologia , Proteínas Virais/metabolismo , COVID-19/virologia , Regulação da Expressão Gênica , Células HEK293 , Humanos , Imunidade , Interferon gama/metabolismo , Espaço Intracelular , Agregação Patológica de Proteínas , Mucosa Respiratória/virologia
10.
Sci Rep ; 11(1): 5665, 2021 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-33707466

RESUMO

The alkylating agent, temozolomide (TMZ), is the most commonly used chemotherapeutic for the treatment of glioblastoma (GBM). The anti-glioma effect of TMZ involves a complex response that includes G2-M cell cycle arrest and cyclin-dependent kinase 1 (CDK1) activation. While CDK1 phosphorylation is a well-described consequence of TMZ treatment, we find that TMZ also robustly induces CDK1 expression. Analysis of this pathway demonstrates that CDK1 is regulated by NF-κB via a putative κB-site in its proximal promoter. CDK1 was induced in a manner dependent on mature p50 and the atypical inhibitor κB protein, BCL-3. Treatment with TMZ induced binding of NF-κB to the κB-site as assessed by gel shift analysis and chromatin immunoprecipitation. Examination of a CDK1 promoter-reporter demonstrated the functional relevance of the κB-site and underlined the requirement of p50 and BCL-3 for activation. Targeted knockdown of CDK1 or chemical inhibition with the selective CDK1 inhibitor, RO-3306, potentiated the cytotoxic effect of TMZ. These results identify CDK1 as an NF-κB target gene regulated by p50 and BCL-3 and suggest that targeting CDK1 may be a strategy to improve the efficacy of TMZ against GBM.


Assuntos
Neoplasias Encefálicas/metabolismo , Proteína Quinase CDC2/metabolismo , Glioblastoma/metabolismo , NF-kappa B/metabolismo , Temozolomida/farmacologia , Proteína 3 do Linfoma de Células B/metabolismo , Sequência de Bases , Sítios de Ligação , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Proteína Quinase CDC2/genética , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glioblastoma/genética , Glioblastoma/patologia , Humanos , Regiões Promotoras Genéticas/genética
11.
Nat Commun ; 11(1): 5007, 2020 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-33024116

RESUMO

p50, the mature product of NFKB1, is constitutively produced from its precursor, p105. Here, we identify BARD1 as a p50-interacting factor. p50 directly associates with the BARD1 BRCT domains via a C-terminal phospho-serine motif. This interaction is induced by ATR and results in mono-ubiquitination of p50 by the BARD1/BRCA1 complex. During the cell cycle, p50 is mono-ubiquitinated in S phase and loss of this post-translational modification increases S phase progression and chromosomal breakage. Genome-wide studies reveal a substantial decrease in p50 chromatin enrichment in S phase and Cycln E is identified as a factor regulated by p50 during the G1 to S transition. Functionally, interaction with BARD1 promotes p50 protein stability and consistent with this, in human cancer specimens, low nuclear BARD1 protein strongly correlates with low nuclear p50. These data indicate that p50 mono-ubiquitination by BARD1/BRCA1 during the cell cycle regulates S phase progression to maintain genome integrity.


Assuntos
Neoplasias da Mama/metabolismo , Ciclo Celular/fisiologia , Instabilidade Genômica , Subunidade p50 de NF-kappa B/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Animais , Sítios de Ligação , Neoplasias da Mama/mortalidade , Linhagem Celular Tumoral , Feminino , Fibroblastos , Humanos , Lisina/metabolismo , Camundongos , Subunidade p50 de NF-kappa B/genética , Neuroblastoma/metabolismo , Domínios Proteicos , Processamento de Proteína Pós-Traducional , Serina/metabolismo , Proteínas Supressoras de Tumor/genética , Ubiquitina-Proteína Ligases/genética , Ubiquitinação
12.
Fish Shellfish Immunol ; 26(5): 744-50, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19328855

RESUMO

A high-quality cDNA library was constructed from whole body tissues of the zhikong scallop, Chlamys farreri, challenged by Listonella anguillarum. A total of 5720 clones were sequenced, yielding 5123 expressed sequence tags (ESTs). Among the 3326 unique genes identified, 2289 (69%) genes had no significant (E-value < 1e-5) matches to known sequences in public databases and 194 (6%) matched proteins of unknown functions. The remaining 843 (25%) genes that exhibited homology with genes of known functions, showed broad involvement in metabolic processes (31%), cell structure and motility (20%), gene and protein expression (12%), cell signaling and cell communication (8%), cell division (4%), and notably, 25% of those genes were related to immune function. They included stress response genes, complement-like genes, proteinase and proteinase inhibitors, immune recognition receptors and immune effectors. The EST collection obtained in this study provides a useful resource for gene discovery and especially for the identification of host-defense genes and systems in scallops and other molluscs.


Assuntos
Etiquetas de Sequências Expressas , Pectinidae/genética , Pectinidae/imunologia , Animais , Proteínas do Sistema Complemento/genética , Dados de Sequência Molecular , Muramidase/genética , Pectinidae/enzimologia , Peptídeo Hidrolases/genética , Inibidores de Proteases , Estresse Fisiológico/genética
13.
Mol Biol Rep ; 36(6): 1637-45, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18819019

RESUMO

Cyclophilin A (CypA), a receptor for the immunosuppressive agent cyclosporin A (CsA), is a cis-trans peptidyl-prolyl isomerase (PPIase) which accelerates the cis-trans isomerization of prolyl-peptide bonds, interacts with a variety of proteins and therefore regulates their activities. One CypA (designated CfCypA) cDNA was cloned from Chlamys farreri by expressed sequence tag (EST) and rapid amplification of cDNA ends (RACE) techniques. The full-length cDNA of CfCypA consisted of 1,248 nucleotides with a canonical polyadenylation signal sequence AATAAA, a poly (A) tail, and an open reading frame (ORF) of 495 nucleotides encoding a polypeptide of 164 amino acids. The deduced amino acid sequence shared high similarity with CypA from the other species, indicating that CfCypA should be a new member of the CypA family. Quantitative real-time (RT) PCR was employed to assess the mRNA expression of CfCypA in various tissues and its temporal expression in haemocytes and gonad of scallops challenged with Vibrio anguillarum. The mRNA transcripts of CfCypA could be detected in all the examined tissues with highest expression level in gonad. After bacterial challenge, the expression level of CfCypA was almost unchanged in haemocytes, but up-regulated in gonad and increased to the peak (22.59-fold; P < 0.05) at 4 h post-injection, and then dropped to the original level at 8 h post-injection. These results indicated that CfCypA was constitutive expressed in haemocytes, but could be induced in gonad, and perhaps played a critical role in response to the bacterial challenge in gonad.


Assuntos
Ciclofilina A/genética , Regulação da Expressão Gênica/imunologia , Pectinidae/genética , Animais , Sequência de Bases , Clonagem Molecular , DNA Complementar/genética , Gônadas , Hemócitos , Dados de Sequência Molecular , Pectinidae/imunologia , RNA Mensageiro/análise , Distribuição Tecidual , Vibrio/imunologia
14.
Cancer Res ; 79(10): 2536-2548, 2019 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-30940658

RESUMO

Alkylating chemotherapy is a central component of the management of glioblastoma (GBM). Among the factors that regulate the response to alkylation damage, NF-κB acts to both promote and block cytotoxicity. In this study, we used genome-wide expression analysis in U87 GBM to identify NF-κB-dependent factors altered in response to temozolomide and found the long noncoding RNA (lncRNA) MALAT1 as one of the most significantly upregulated. In addition, we demonstrated that MALAT1 expression was coregulated by p50 (p105) and p53 via novel κB- and p53-binding sites in the proximal MALAT1 coding region. Temozolomide treatment inhibited p50 recruitment to its cognate element as a function of Ser329 phosphorylation while concomitantly increasing p53 recruitment. Moreover, luciferase reporter studies demonstrated that both κB and p53 cis-elements were required for efficient transactivation in response to temozolomide. Depletion of MALAT1 sensitized patient-derived GBM cells to temozolomide cytotoxicity, and in vivo delivery of nanoparticle-encapsulated anti-MALAT1 siRNA increased the efficacy of temozolomide in mice bearing intracranial GBM xenografts. Despite these observations, in situ hybridization of GBM specimens and analysis of publicly available datasets revealed that MALAT1 expression within GBM tissue was not prognostic of overall survival. Together, these findings support MALAT1 as a target for chemosensitization of GBM and identify p50 and p52 as primary regulators of this ncRNA. SIGNIFICANCE: These findings identify NF-κB and p53 as regulators of the lncRNA MALAT1 and suggest MALAT1 as a potential target for the chemosensitization of GBM.


Assuntos
Antineoplásicos Alquilantes/uso terapêutico , Neoplasias Encefálicas/metabolismo , Glioblastoma/tratamento farmacológico , NF-kappa B/metabolismo , RNA Longo não Codificante/biossíntese , Temozolomida/uso terapêutico , Proteína Supressora de Tumor p53/metabolismo , Animais , Linhagem Celular Tumoral , Dano ao DNA/genética , Técnicas de Silenciamento de Genes , Glioblastoma/metabolismo , Humanos , Masculino , Camundongos , Camundongos Nus , Prognóstico , RNA Longo não Codificante/genética , Ensaios Antitumorais Modelo de Xenoenxerto
15.
Mol Immunol ; 44(4): 360-8, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16597463

RESUMO

Antimicrobial peptides are important components of the host innate immune responses by exerting broad-spectrum microbicidal activity against pathogenic microbes. The first mollusk big defensin (designated AiBD) cDNA was cloned from bay scallop Argopecten irradians by expressed sequence tag (EST) and rapid amplification of cDNA ends (RACE) techniques. The scallop AiBD consisted of 531 nucleotides with a canonical polyadenylation signal sequence AATAAA and a poly(A) tail, encoding a polypeptide of 122 amino acids. The high similarity of AiBD deduced amino acid sequence with big defensin from Tachypleus tridentatus and Branchiostoma belcheri tsingtaunese indicated that AiBD should be a member of big defensin family. The expression of AiBD in various tissues was measured by using Northern blotting analysis. mRNA transcripts of AiBD could be detected in haemocytes of unchallenged scallops. The temporal expression of AiBD in haemolymph after Vibrio anguilarum challenge was recorded by quantitative real time PCR. The relative expression level of AiBD in haemolymph was up-regulated evenly in the first 8 h, followed by a drastic increase, and increased 131.1-fold at 32 h post-injection. These results indicated that AiBD could be induced by bacterial challenge, and it should participate in the immune responses of A. irradians. Biological activity assay revealed that recombinant AiBD could inhibit the growth of both Gram-positive and Gram-negative bacteria, and also showed strong fungicidal activity towards the expression host. Recombinant expression of AiBD made it possible to further characterize its functions involved in immune responses, and also provided a potential therapeutic agent for disease control in aquaculture.


Assuntos
Defensinas/genética , Pectinidae/genética , Sequência de Aminoácidos , Animais , Anti-Infecciosos/farmacologia , Bactérias/efeitos dos fármacos , Sequência de Bases , Clonagem Molecular , DNA Complementar/genética , DNA Complementar/isolamento & purificação , Defensinas/biossíntese , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Proteínas Recombinantes/genética , Proteínas Recombinantes/farmacologia , Alinhamento de Sequência
16.
Hydrol Process ; 32(22): 3365-3390, 2018 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31073260

RESUMO

Accurate and reliable reservoir inflow forecast is instrumental to the efficient operation of the hydroelectric power systems. It has been discovered that natural and anthropogenic aerosols have a great influence on meteorological variables such as temperature, snow water equivalent, and precipitation, which in turn impact the reservoir inflow. Therefore, it is imperative for us to quantify the impact of aerosols on reservoir inflow and to incorporate the aerosol models into future reservoir inflow forecasting models. In this paper, a comprehensive framework was developed to quantify the impact of aerosols on reservoir inflow by integrating the Weather Research and Forecasting model with Chemistry (WRF-Chem) and a dynamic regression model. The statistical dynamic regression model produces forecasts for reservoir inflow based on the meteorological output variables from the WRF-Chem model. The case study was performed on the Florence Lake and Lake Thomas Alva Edison of the Big Creek Hydroelectric Project in the San Joaquin Region. The simulation results show that the presence of aerosols results in a significant reduction of annual reservoir inflow by 4-14%. In the summer, aerosols reduce precipitation, snow water equivalent, and snowmelt that leads to a reduction in inflow by 11-26%. In the spring, aerosols increase temperature and snowmelt which leads to an increase in inflow by 0.6-2%. Aerosols significantly reduce the amount of inflow in the summer when the marginal value of water is extremely high and slightly increase the inflow in the spring when the run-off risk is high. In summary, the presence of aerosols is detrimental to the optimal utilization of hydroelectric power systems.

17.
Sci Transl Med ; 10(448)2018 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-29973405

RESUMO

The response of patients with gliomas to alkylating chemotherapy is heterogeneous. However, there are currently no universally accepted predictors of patient response to these agents. We identify the nuclear factor κB (NF-κB) co-regulator B cell CLL/lymphoma 3 (BCL-3) as an independent predictor of response to temozolomide (TMZ) treatment. In glioma patients with tumors that have a methylated O6-methylguanine DNA methyltransferase (MGMT) promoter, high BCL-3 expression was associated with a poor response to TMZ. Mechanistically, BCL-3 promoted a more malignant phenotype by inducing an epithelial-to-mesenchymal transition in glioblastomas through promoter-specific NF-κB dimer exchange. Carbonic anhydrase II (CAII) was identified as a downstream factor promoting BCL-3-mediated resistance to chemotherapy. Experiments in glioma xenograft mouse models demonstrated that the CAII inhibitor acetazolamide enhanced survival of TMZ-treated animals. Our data suggest that BCL-3 might be a useful indicator of glioma response to alkylating chemotherapy and that acetazolamide might be repurposed as a chemosensitizer for treating TMZ-resistant gliomas.


Assuntos
Antineoplásicos Alquilantes/uso terapêutico , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/genética , Resistencia a Medicamentos Antineoplásicos , Regulação Neoplásica da Expressão Gênica , Glioma/tratamento farmacológico , Glioma/genética , Proteínas Proto-Oncogênicas/genética , Fatores de Transcrição/genética , Antineoplásicos Alquilantes/farmacologia , Proteína 3 do Linfoma de Células B , Anidrase Carbônica II/metabolismo , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Análise Multivariada , NF-kappa B/metabolismo , Regiões Promotoras Genéticas/genética , Modelos de Riscos Proporcionais , Multimerização Proteica , Proteínas Proto-Oncogênicas/metabolismo , Análise de Sobrevida , Temozolomida/farmacologia , Temozolomida/uso terapêutico , Fator de Transcrição RelA/metabolismo , Fatores de Transcrição/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
18.
Dev Comp Immunol ; 31(6): 548-58, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17064771

RESUMO

Peptidoglycan recognition proteins (PGRPs) are a type of pattern recognition molecules (PRM) that recognize the unique cell wall component peptidoglycan (PGN) of bacteria and are involved in innate immunity. The first bivalve PGRP cDNA sequence was cloned from bay scallop Argopecten irradians by expressed sequence tag (EST) and PCR technique. The full-length cDNA of bay scallop PGRP (designated AiPGRP) gene contained 1018bp with a 615-bp open reading frame that encoded a polypeptide of 205 amino acids. The predicted amino acid sequence of AiPGRP shared high identity with PGRP in other organisms, such as PGRP precursor in Trichoplusia ni and PGRP SC2 in Drosophila melanogaster. A quantitative reverse transcriptase Real-Time PCR (qRT-PCR) assay was developed to assess the mRNA expression of AiPGRP in different tissues and the temporal expression of AiPGRP in the mixed primary cultured hemocytes challenged by microbial components lipopolyssacharide (LPS) from Escherichia coli and PGN from Micrococcus luteus. Higher-level mRNA expression of AiPGRP was detected in the tissues of hemocytes, gonad and kidney. The expression of AiPGRP in the mixed primary cultured hemocytes was up regulated after stimulated by PGN, while LPS from E. coli did not induce AiPGRP expression. The results indicated that AiPGRP was a constitutive and inducible expressed protein that was mainly induced by PGN and could be involved in scallop immune response against Gram-positive bacteria infection.


Assuntos
Proteínas de Transporte/genética , Pectinidae/genética , Pectinidae/imunologia , RNA Mensageiro/biossíntese , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , DNA Complementar/análise , Expressão Gênica , Biblioteca Gênica , Humanos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homologia de Sequência de Aminoácidos
19.
Comp Biochem Physiol B Biochem Mol Biol ; 147(4): 704-15, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17553718

RESUMO

Heat shock protein 90 (HSP90) is a highly conserved molecular chaperone contributing to the folding, maintenance of structural integrity and proper regulation of a subset of cytosolic proteins. The full-length cDNA of Zhikong scallop Chlamys farreri HSP90 (designated CfHSP90) was cloned by EST and rapid RACE techniques. It was of 2710 bp, including an open reading frame (ORF) of 2181 bp encoding a polypeptide of 726 amino acids with all the five HSP90 family signatures. BLAST analysis revealed that the CfHSP90 gene shared high similarity with other known HSP90 genes. Fluorescent real-time quantitative RT-PCR was used to examine the expression pattern of CfHSP90 mRNA in haemocytes of scallops exposed to Cd2+, Pb2+ and Cu2+ for 10 and 20 days, respectively. All the three heavy metals could induce CfHSP90 expression. There was a clear dose-dependent expression pattern of CfHSP90 after heavy metals exposure for 10 days or 20 days. Different concentrations of the same metal resulted in different effects on CfHSP90 expression. The results indicated that CfHSP90 responded to various heavy metal stresses with a dose-dependent expression pattern as well as exposure time effect, and could be used as a molecular biomarker in a heavy metal polluted environment.


Assuntos
Clonagem Molecular , Monitoramento Ambiental/métodos , Proteínas de Choque Térmico HSP90/genética , Hemócitos/metabolismo , Pectinidae/genética , Sequência de Aminoácidos , Animais , Biomarcadores , DNA Complementar/isolamento & purificação , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/efeitos dos fármacos , Proteínas de Choque Térmico HSP90/metabolismo , Metais Pesados/farmacologia , Dados de Sequência Molecular , Pectinidae/metabolismo , Filogenia , RNA Mensageiro/metabolismo , Homologia de Sequência de Aminoácidos , Poluição Química da Água/análise
20.
Earth Space Sci ; 4(8): 574-587, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-29104900

RESUMO

This paper describes a forward radiative transfer model and retrieval system (FMRS) for the Tropospheric Water and cloud ICE (TWICE) CubeSat instrument. We use the FMRS to simulate radiances for the TWICE's 14 millimeter- and submillimeter-wavelength channels for a tropical atmospheric state produced by a Weather Research and Forecasting model simulation. We also perform simultaneous retrievals of cloud ice particle size, ice water content (IWC), water vapor content (H2O), and temperature from the simulated TWICE radiances using the FMRS. We show that the TWICE instrument is capable of retrieving ice particle size in the range of ~50-1000 µm in mass mean effective diameter with approximately 50% uncertainty. The uncertainties of other retrievals from TWICE are about 1 K for temperature, 50% for IWC, and 20% for H2O.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA