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1.
Nat Immunol ; 15(2): 152-60, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24317040

RESUMO

High-density lipoprotein (HDL) mediates reverse cholesterol transport and is known to be protective against atherosclerosis. In addition, HDL has potent anti-inflammatory properties that may be critical for protection against other inflammatory diseases. The molecular mechanisms of how HDL can modulate inflammation, particularly in immune cells such as macrophages, remain poorly understood. Here we identify the transcriptional regulator ATF3, as an HDL-inducible target gene in macrophages that downregulates the expression of Toll-like receptor (TLR)-induced proinflammatory cytokines. The protective effects of HDL against TLR-induced inflammation were fully dependent on ATF3 in vitro and in vivo. Our findings may explain the broad anti-inflammatory and metabolic actions of HDL and provide the basis for predicting the success of new HDL-based therapies.


Assuntos
Fator 3 Ativador da Transcrição/metabolismo , Anti-Inflamatórios não Esteroides/uso terapêutico , Aterosclerose/terapia , Colesterol/metabolismo , Inflamação/terapia , Lipoproteínas HDL/uso terapêutico , Macrófagos/efeitos dos fármacos , Fator 3 Ativador da Transcrição/genética , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Células Cultivadas , Imunoprecipitação da Cromatina , Citocinas/metabolismo , Feminino , Perfilação da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Lipoproteínas HDL/farmacologia , Ativação de Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Biologia de Sistemas , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/imunologia
2.
Immunity ; 36(5): 795-806, 2012 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-22633459

RESUMO

Primary resistance to pathogens is reliant on both basal and inducible immune defenses. To date, research has focused upon inducible innate immune responses. In contrast to resistance via cytokine induction, basal defense mechanisms are less evident. Here we showed that the antiviral protein kinase R (PKR) inhibited the key actin-modifying protein gelsolin to regulate actin dynamics and control cytoskeletal cellular functions under homeostatic conditions. Through this mechanism, PKR controlled fundamental innate immune, actin-dependent processes that included membrane ruffling and particle engulfment. Accordingly, PKR counteracted viral entry into the cell. These findings identify a layer of host resistance, showing that the regulation of actin-modifying proteins during the innate immune response bolsters first-line defense against intracellular pathogens and has a sustained effect on virus production. Moreover, these data provide proof of principle for a concept in which the cell cytoskeleton could be targeted to elicit broad antiviral protection.


Assuntos
Actinas/metabolismo , Gelsolina/metabolismo , Imunidade Inata/imunologia , eIF-2 Quinase/metabolismo , Actinas/imunologia , Linhagem Celular Transformada , Linhagem Celular Tumoral , Citocinas/imunologia , Citocinas/metabolismo , Citoesqueleto/imunologia , Citoesqueleto/metabolismo , Gelsolina/antagonistas & inibidores , Gelsolina/imunologia , Células HEK293 , Células HeLa , Humanos , Proteínas dos Microfilamentos/imunologia , Proteínas dos Microfilamentos/metabolismo , Domínios e Motivos de Interação entre Proteínas/imunologia , Vírus/imunologia , Vírus/metabolismo , eIF-2 Quinase/imunologia
3.
Immunity ; 35(4): 491-3, 2011 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-22035841

RESUMO

The crystal structure of the interferon-induced member of the dynamin family MxA presented by Gao et al. (2011) in this issue of Immunity reveals the molecule's higher-order structure, thereby providing insight into the protein's antiviral action as a molecular machine.

4.
J Immunol ; 2017 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-28794235

RESUMO

The pathology of inflammatory bowel diseases is driven by the inflammatory signaling pathways associated with mucosal epithelial damage. Myeloid cells are known to play an essential role in mediating epithelial inflammatory responses during injury. However, the precise role of these cells in stimulating intestinal inflammation and the subsequent tissue damage is unclear. In this article, we show that expression of integrin-linked kinase (ILK) in myeloid cells is critical for the epithelial inflammatory signaling during colitis induced by dextran sodium sulfate. Myeloid ILK (M-ILK) deficiency significantly ameliorates the pathology of experimental colitis. In response to dextran sodium sulfate, colonic infiltration of neutrophils and inflammatory cytokine production are impaired in M-ILK-deficient mice, and activation of epithelial NF-κB and PI3K signaling pathways are restricted by the M-ILK deficiency. In contrast, reduced epithelial damage in M-ILK-deficient mice is correlated with elevated levels of epithelial Stat3 activation and proliferation. Moreover, M-ILK-dependent inflammatory signaling in the mucosal epithelium can be therapeutically targeted by the pharmacological inhibition of ILK during experimental colitis. Collectively, these findings identify M-ILK as a critical regulator of epithelial inflammatory signaling pathways during colitis and, as a consequence, targeting M-ILK could provide therapeutic benefit.

5.
Nucleic Acids Res ; 45(1): 198-205, 2017 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-27694309

RESUMO

Acridine dyes, including proflavine and acriflavine, were commonly used as antiseptics before the advent of penicillins in the mid-1940s. While their mode of action on pathogens was originally attributed to their DNA intercalating activity, work in the early 1970s suggested involvement of the host immune responses, characterized by induction of interferon (IFN)-like activities through an unknown mechanism. We demonstrate here that sub-toxic concentrations of a mixture of acriflavine and proflavine instigate a cyclic-GMP-AMP (cGAMP) synthase (cGAS)-dependent type-I IFN antiviral response. This pertains to the capacity of these compounds to induce low level DNA damage and cytoplasmic DNA leakage, resulting in cGAS-dependent cGAMP-like activity. Critically, acriflavine:proflavine pre-treatment of human primary bronchial epithelial cells significantly reduced rhinovirus infection. Collectively, our findings constitute the first evidence that non-toxic DNA binding agents have the capacity to act as indirect agonists of cGAS, to exert potent antiviral effects in mammalian cells.


Assuntos
Acriflavina/farmacologia , Antivirais/farmacologia , Fatores Imunológicos/farmacologia , Substâncias Intercalantes/farmacologia , Proteínas de Membrana/genética , Nucleotidiltransferases/genética , Proflavina/farmacologia , Animais , Brônquios/efeitos dos fármacos , Brônquios/imunologia , Brônquios/virologia , Linhagem Celular Transformada , Chlorocebus aethiops , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/imunologia , Células Epiteliais/virologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/imunologia , Fibroblastos/virologia , Regulação da Expressão Gênica , Células HEK293 , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Interações Hospedeiro-Patógeno/imunologia , Humanos , Proteínas de Membrana/agonistas , Proteínas de Membrana/imunologia , Camundongos , Nucleotídeos Cíclicos/imunologia , Nucleotídeos Cíclicos/metabolismo , Nucleotidiltransferases/imunologia , Cultura Primária de Células , Rhinovirus/efeitos dos fármacos , Rhinovirus/crescimento & desenvolvimento , Transdução de Sinais , Células Vero , Carga Viral/efeitos dos fármacos
6.
Cytokine ; 108: 225-231, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29102683

RESUMO

Cytokines and chemokines are intricately connected to cancer initiation, progression and metastasis as well as to innate and adaptive host defense mechanisms against transformed cells. The Aegean Conference on Cytokine Signaling in Cancer (ACCSC) aims to bring together researchers in this highly targeted area of cancer research in a lovely and relaxing Greek-Mediterranean backdrop to discuss latest developments. Being small in size with about one hundred participants, this conference fosters scientific and social interactions among established and emerging scientists in clinical and basic research in diverse fields of oncology, biochemistry, biophysics, genetics and immunology. The 2nd ACCSC held at Heraklion on the Greek island of Crete was organized by Serge Fuchs (University of Pennsylvania), Mathias Muller (University of Veterinary Medicine Vienna), Leonidas Platanias (Northwestern University, Chicago) and Belinda Parker (La Trobe University, Melbourne) between May 30 and June 04, 2017, was a great success in every single aspect of a high level scientific meeting. Signaling within cancer cells as well as in stromal and immune cells is the common thread of this conference series. An outline of the research topics discussed at this conference is presented here to emphasize its high quality and to stimulate interest among cytokine researchers to participate in future ACCSC meetings.


Assuntos
Citocinas/imunologia , Neoplasias/imunologia , Transdução de Sinais , Grécia , Humanos
7.
Immunity ; 30(6): 802-16, 2009 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-19523849

RESUMO

Interferons (IFNs) direct innate and acquired immune responses and, accordingly, are used therapeutically to treat a number of diseases, yet the diverse effects they elicit are not fully understood. Here, we identified the promyelocytic leukemia zinc finger (PLZF) protein as a previously unrecognized component of the IFN response. IFN stimulated an association of PLZF with promyelocytic leukemia protein (PML) and histone deacetylase 1 (HDAC1) to induce a decisive subset of IFN-stimulated genes (ISGs). Consequently, PLZF-deficient mice had a specific ISG expression defect and as a result were more susceptible to viral infection. This susceptibility correlated with a marked decrease in the expression of the key antiviral mediators and an impaired IFN-mediated induction of natural killer cell function. These results provide new insights into the regulatory mechanisms of IFN signaling and the induction of innate antiviral immunity.


Assuntos
Infecções por Alphavirus/imunologia , Imunidade Inata/genética , Interferon-alfa/imunologia , Células Matadoras Naturais/imunologia , Fatores de Transcrição Kruppel-Like/metabolismo , Infecções por Alphavirus/genética , Infecções por Alphavirus/virologia , Animais , Linhagem Celular Tumoral , Fibroblastos/efeitos dos fármacos , Fibroblastos/imunologia , Fibroblastos/virologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Histona Desacetilase 1 , Histona Desacetilases/imunologia , Histona Desacetilases/metabolismo , Interferon-alfa/farmacologia , Células Matadoras Naturais/efeitos dos fármacos , Células Matadoras Naturais/metabolismo , Fatores de Transcrição Kruppel-Like/genética , Fatores de Transcrição Kruppel-Like/imunologia , Camundongos , Camundongos Knockout , Análise de Sequência com Séries de Oligonucleotídeos , Proteína com Dedos de Zinco da Leucemia Promielocítica , Vírus da Floresta de Semliki/efeitos dos fármacos , Vírus da Floresta de Semliki/imunologia , Transdução de Sinais/genética , Transdução de Sinais/imunologia
8.
Proc Natl Acad Sci U S A ; 112(5): 1535-40, 2015 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-25605927

RESUMO

Inflammation is critical for host defense, but without appropriate control, it can cause chronic disease or even provoke fatal responses. Here we identify a mechanism that limits the inflammatory response. Probing the responses of macrophages to the key sensory Toll-like receptors, we identify that the Broad-complex, Tramtrack and Bric-a-brac/poxvirus and zinc finger (BTB/POZ), transcriptional regulator promyelocytic leukemia zinc finger (PLZF) limits the expression of inflammatory gene products. In accord with this finding, PLZF-deficient animals express higher levels of potent inflammatory cytokines and mount exaggerated inflammatory responses to infectious stimuli. Temporal quantitation of inflammatory gene transcripts shows increased gene induction in the absence of PLZF. Genome-wide analysis of histone modifications distinguish that PLZF establishes basal activity states of early response genes to maintain immune homeostasis and limit damaging inflammation. We show that PLZF stabilizes a corepressor complex that encompasses histone deacetylase activity to control chromatin. Together with our previous demonstration that PLZF promotes the antiviral response, these results suggest a strategy that could realize one of the major goals of immune therapy to retain immune resistance to pathogens while curbing damaging inflammation.


Assuntos
Cromatina/metabolismo , Inflamação/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , Transdução de Sinais , Animais , Infecções Bacterianas/metabolismo , Imunoprecipitação da Cromatina , Transferência Ressonante de Energia de Fluorescência , Histona Desacetilases/metabolismo , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Proteína com Dedos de Zinco da Leucemia Promielocítica , Reação em Cadeia da Polimerase em Tempo Real
9.
J Transl Med ; 15(1): 206, 2017 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-29025424

RESUMO

BACKGROUND: Understanding immune phenotypes and human gastric disease in situ requires an approach that leverages multiplexed immunohistochemistry (mIHC) with multispectral imaging to facilitate precise image analyses. METHODS: We developed a novel 4-color mIHC assay based on tyramide signal amplification that allowed us to reliably interrogate immunologic checkpoints, including programmed death-ligand 1 (PD-L1), cytotoxic T cells (CD8+T) and regulatory T cells (Foxp3), in formalin-fixed, paraffin-embedded tissues of various human gastric diseases. By observing cell phenotypes within the disease tissue microenvironment, we were able to determine specific co-localized staining combinations and various measures of cell density. RESULTS: We found that PD-L1 was expressed in gastric ulcer and in tumor cells (TCs), as well as in tumor-infiltrating immune cells (TIICs), but not in normal gastric mucosa or other gastric intraepithelial neoplastic tissues. Furthermore, we found no significant reduction in CD8+T cells, whereas the ratio of CD8+T:Foxp3 cells and CD8+T:PD-L1 cells was suppressed in tumor tissues and elevated in adjacent normal tissues. An unsupervised hierarchical analysis also identified correlations between CD8+T and Foxp3+ tumor-infiltrating lymphocyte (TIL) densities and average PD-L1 levels. Three main groups were identified based on the results of CD8+T:PD-L1 ratios in gastric tumor tissues. Furthermore, integrating CD8+T:Foxp3 ratios, which increased the complexity for immune phenotype status, revealed 6-7 clusters that enabled the separation of gastric cancer patients at the same clinical stage into different risk-group subsets. CONCLUSIONS: Characterizing immune phenotypes in human gastric disease tissues via multiplexed immunohistochemistry may help guide PD-L1 clinical therapy. Observing unique disease tissue microenvironments can improve our understanding of immune phenotypes and cell interactions within these microenvironments, providing the ability to predict safe responses to immunotherapies.


Assuntos
Imuno-Histoquímica/métodos , Gastropatias/imunologia , Gastropatias/patologia , Antígeno B7-H1/metabolismo , Linfócitos T CD8-Positivos/imunologia , Fatores de Transcrição Forkhead/metabolismo , Humanos , Fenótipo
10.
Nucleic Acids Res ; 43(2): 1177-88, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25539920

RESUMO

Anti-microRNA (miRNA) oligonucleotides (AMOs) with 2'-O-Methyl (2'OMe) residues are commonly used to study miRNA function and can achieve high potency, with low cytotoxicity. Not withstanding this, we demonstrate the sequence-dependent capacity of 2'OMe AMOs to inhibit Toll-like receptor (TLR) 7 and 8 sensing of immunostimulatory RNA, independent of their miRNA-targeting function. Through a screen of 29 AMOs targeting common miRNAs, we found a subset of sequences highly inhibitory to TLR7 sensing in mouse macrophages. Interspecies conservation of this inhibitory activity was confirmed on TLR7/8 activity in human peripheral blood mononuclear cells. Significantly, we identified a core motif governing the inhibitory activity of these AMOs, which is present in more than 50 AMOs targeted to human miRNAs in miRBaseV20. DNA/locked nucleic acids (LNA) AMOs synthesized with a phosphorothioate backbone also inhibited TLR7 sensing in a sequence-dependent manner, demonstrating that the off-target effects of AMOs are not restricted to 2'OMe modification. Taken together, our work establishes the potential for off-target effects of AMOs on TLR7/8 function, which should be taken into account in their therapeutic development and in vivo application.


Assuntos
MicroRNAs/antagonistas & inibidores , Oligonucleotídeos/química , Receptor 7 Toll-Like/antagonistas & inibidores , Receptor 8 Toll-Like/antagonistas & inibidores , Adjuvantes Imunológicos/farmacologia , Animais , Sequência de Bases , Células HEK293 , Humanos , Camundongos , Motivos de Nucleotídeos , RNA/farmacologia
11.
J Biol Chem ; 290(52): 30813-29, 2015 Dec 25.
Artigo em Inglês | MEDLINE | ID: mdl-26518879

RESUMO

Mutations of human telomerase RNA component (TERC) and telomerase reverse transcriptase (TERT) are associated with a subset of lung aging diseases, but the mechanisms by which TERC and TERT participate in lung diseases remain unclear. In this report, we show that knock-out (KO) of the mouse gene Terc or Tert causes pulmonary alveolar stem cell replicative senescence, epithelial impairment, formation of alveolar sacs, and characteristic inflammatory phenotype. Deficiency in TERC or TERT causes a remarkable elevation in various proinflammatory cytokines, including IL-1, IL-6, CXCL15 (human IL-8 homolog), IL-10, TNF-α, and monocyte chemotactic protein 1 (chemokine ligand 2 (CCL2)); decrease in TGF-ß1 and TGFßRI receptor in the lungs; and spillover of IL-6 and CXCL15 into the bronchoalveolar lavage fluids. In addition to increased gene expressions of α-smooth muscle actin and collagen 1α1, suggesting myofibroblast differentiation, TERC deficiency also leads to marked cellular infiltrations of a mononuclear cell population positive for the leukocyte common antigen CD45, low-affinity Fc receptor CD16/CD32, and pattern recognition receptor CD11b in the lungs. Our data demonstrate for the first time that telomerase deficiency triggers alveolar stem cell replicative senescence-associated low-grade inflammation, thereby driving pulmonary premature aging, alveolar sac formation, and fibrotic lesion.


Assuntos
Pneumopatias/imunologia , Alvéolos Pulmonares/enzimologia , Células-Tronco/citologia , Telomerase/deficiência , Animais , Senescência Celular , Feminino , Humanos , Interleucina-1/genética , Interleucina-1/imunologia , Interleucina-6/genética , Interleucina-6/imunologia , Pulmão/citologia , Pulmão/imunologia , Pneumopatias/enzimologia , Pneumopatias/genética , Pneumopatias/fisiopatologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Alvéolos Pulmonares/citologia , Alvéolos Pulmonares/imunologia , RNA/genética , Células-Tronco/imunologia , Telomerase/genética , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/imunologia
12.
J Biol Chem ; 289(40): 27776-93, 2014 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-25100717

RESUMO

Integrin-linked kinase (ILK) is a ubiquitously expressed and highly conserved serine-threonine protein kinase that regulates cellular responses to a wide variety of extracellular stimuli. ILK is involved in cell-matrix interactions, cytoskeletal organization, and cell signaling. ILK signaling has also been implicated in oncogenesis and progression of cancers. However, its role in the innate immune system remains unknown. Here, we show that ILK mediates pro-inflammatory signaling in response to lipopolysaccharide (LPS). Pharmacological or genetic inhibition of ILK in mouse embryonic fibroblasts and macrophages selectively blocks LPS-induced production of the pro-inflammatory cytokine tumor necrosis factor α (TNF-α). ILK is required for LPS-induced activation of nuclear factor κB (NF-κB) and transcriptional induction of TNF-α. The modulation of LPS-induced TNF-α synthesis by ILK does not involve the classical NF-κB pathway, because IκB-α degradation and p65 nuclear translocation are both unaffected by ILK inhibition. Instead, ILK is involved in an alternative activation of NF-κB signaling by modulating the phosphorylation of p65 at Ser-536. Furthermore, ILK-mediated alternative NF-κB activation through p65 Ser-536 phosphorylation also occurs during Helicobacter pylori infection in macrophages and gastric cancer cells. Moreover, ILK is required for H. pylori-induced TNF-α secretion in macrophages. Although ILK-mediated phosphorylation of p65 at Ser-536 is independent of the phosphatidylinositol 3-kinase (PI3K)/Akt pathway during LPS stimulation, upon H. pylori infection this event is dependent on the PI3K/Akt pathway. Our findings implicate ILK as a critical regulatory molecule for the NF-κB-mediated pro-inflammatory signaling pathway, which is essential for innate immune responses against pathogenic microorganisms.


Assuntos
Infecções por Helicobacter/enzimologia , Helicobacter pylori/fisiologia , Lipopolissacarídeos/metabolismo , NF-kappa B/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , eIF-2 Quinase/química , eIF-2 Quinase/metabolismo , Motivos de Aminoácidos , Animais , Regulação da Expressão Gênica , Infecções por Helicobacter/genética , Infecções por Helicobacter/metabolismo , Infecções por Helicobacter/microbiologia , Humanos , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/genética , Fosforilação , Proteínas Serina-Treonina Quinases/genética , Serina/metabolismo , Fator de Necrose Tumoral alfa/genética , eIF-2 Quinase/genética
13.
J Biol Chem ; 289(7): 4316-25, 2014 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-24362029

RESUMO

MicroRNA-155 (miR-155) is highly expressed in many cancers such as B cell lymphomas and myeloid leukemia and inflammatory disorders such as rheumatoid arthritis, atopic dermatitis, and multiple sclerosis. The role of miR-155 as both a promoter of inflammation and an oncogenic agent provides a clear need for miR-155 itself to be stringently regulated. We therefore investigated the transcriptional regulation of miR-155 in response to the respective pro- and anti-inflammatory mediators LPS and IL-10. Bioinformatic analysis revealed Ets binding sites on the miR-155 promoter, and we found that Ets2 is critical for miR-155 induction by LPS. Truncation and mutational analysis of the miR-155 promoter confirmed the role of the Ets2 binding site proximal to the transcription start site for LPS responsiveness. We observed increased binding of Ets2 to the miR-155 promoter and Ets2 deficient mice displayed decreased induction of miR-155 in response to LPS. IL-10 inhibited the induction of Ets2 mRNA and protein by LPS, thereby decreasing Ets2 function on the pri-155 promoter. We have thus identified Ets2 as a key novel regulator in both the positive and negative control of miR-155 in the inflammatory response.


Assuntos
Lipopolissacarídeos/toxicidade , MicroRNAs/biossíntese , Proteína Proto-Oncogênica c-ets-2/metabolismo , Elementos de Resposta , Animais , Linhagem Celular , Humanos , Inflamação/induzido quimicamente , Inflamação/genética , Inflamação/metabolismo , Inflamação/patologia , Interleucina-10/biossíntese , Interleucina-10/genética , Camundongos , MicroRNAs/genética , Proteína Proto-Oncogênica c-ets-2/genética
14.
RNA ; 19(7): 876-88, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23709276

RESUMO

Recent studies have established that mutations or deletions in microRNA (miRNA) processing enzymes resulting in a global decrease of miRNA expression are frequent across cancers and can be associated with a poorer prognosis. While very popular in miRNA profiling studies, it remains unclear whether miRNA microarrays are suited or not to accurately detecting global miRNA decreases seen in cancers. In this work, we analyzed the miRNA profiles of samples with global miRNA decreases using Affymetrix miRNA microarrays following the inducible genetic deletion of Dicer1. Surprisingly, up to a third of deregulated miRNAs identified upon Dicer1 depletion were found to be up-regulated following standard robust multichip average (RMA) background correction and quantile normalization, indicative of normalization bias. Our comparisons of five preprocess steps performed at the probe level demonstrated that the use of cyclic loess relying on non-miRNA small RNAs present on the Affymetrix platform significantly improved specificity and sensitivity of detection of decreased miRNAs. These findings were validated in samples from patients with prostate cancer, where conjugation of robust normal-exponential background correction with cyclic loess normalization and array weights correctly identified the greatest number of decreased miRNAs, and the lowest amount of false-positive up-regulated miRNAs. These findings highlight the importance of miRNA microarray normalization for the detection of miRNAs that are truly differentially expressed and suggest that the use of cyclic loess based on non-miRNA small RNAs can help to improve the sensitivity and specificity of miRNA profiling in cancer samples with global miRNA decrease.


Assuntos
RNA Helicases DEAD-box/genética , Regulação Neoplásica da Expressão Gênica , MicroRNAs/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Neoplasias da Próstata/diagnóstico , RNA Neoplásico/metabolismo , Ribonuclease III/genética , Animais , Biologia Computacional/métodos , RNA Helicases DEAD-box/metabolismo , Regulação para Baixo , Fibroblastos/metabolismo , Deleção de Genes , Humanos , Masculino , Camundongos , MicroRNAs/genética , Sondas RNA/genética , Sondas RNA/metabolismo , RNA Neoplásico/genética , Ribonuclease III/metabolismo , Sensibilidade e Especificidade , Regulação para Cima
15.
J Virol ; 88(2): 799-810, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24227841

RESUMO

RNA-specific adenosine deaminase (ADAR)-mediated adenosine-to-inosine (A-to-I) editing is a critical arm of the antiviral response. However, mechanistic insights into how A-to-I RNA editing affects viral infection are lacking. We posited that inosine incorporation into RNA facilitates sensing of nonself RNA by innate immune sensors and accordingly investigated the impact of inosine-modified RNA on Toll-like receptor 7 and 8 (TLR7/8) sensing. Inosine incorporation into synthetic single-stranded RNA (ssRNA) potentiated tumor necrosis factor alpha (TNF-α) or alpha interferon (IFN-α) production in human peripheral blood mononuclear cells (PBMCs) in a sequence-dependent manner, indicative of TLR7/8 recruitment. The effect of inosine incorporation on TLR7/8 sensing was restricted to immunostimulatory ssRNAs and was not seen with inosine-containing short double-stranded RNAs or with a deoxy-inosine-modified ssRNA. Inosine-mediated increase of self-secondary structure of an ssRNA resulted in potentiated IFN-α production in human PBMCs through TLR7 recruitment, as established through the use of a TLR7 antagonist and Tlr7-deficient cells. There was a correlation between hyperediting of influenza A viral ssRNA and its ability to stimulate TNF-α, independent of 5'-triphosphate residues, and involving Adar-1. Furthermore, A-to-I editing of viral ssRNA directly enhanced mouse Tlr7 sensing, when present in proportions reproducing biologically relevant levels of RNA editing. Thus, we demonstrate for the first time that inosine incorporation into immunostimulatory ssRNA can potentiate TLR7/8 activation. Our results suggest a novel function of A-to-I RNA editing, which is to facilitate TLR7/8 sensing of phagocytosed viral RNA.


Assuntos
Vírus da Influenza A Subtipo H1N1/genética , Influenza Humana/imunologia , Influenza Humana/virologia , Inosina/genética , Edição de RNA , RNA Viral/genética , Receptor 7 Toll-Like/imunologia , Receptor 8 Toll-Like/imunologia , Adenosina/genética , Adenosina/imunologia , Adenosina Desaminase/genética , Adenosina Desaminase/imunologia , Animais , Sequência de Bases , Feminino , Humanos , Vírus da Influenza A Subtipo H1N1/imunologia , Influenza Humana/genética , Inosina/imunologia , Interferon-alfa/genética , Interferon-alfa/imunologia , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/virologia , Masculino , Camundongos , Camundongos Knockout , Dados de Sequência Molecular , Conformação de Ácido Nucleico , RNA Viral/química , RNA Viral/imunologia , Receptor 7 Toll-Like/genética , Receptor 8 Toll-Like/genética
16.
Nucleic Acids Res ; 41(5): 3436-45, 2013 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-23325848

RESUMO

The retinoic acid inducible gene-I (RIG-I)-like family of receptors is positioned at the front line of our innate cellular defence system. RIG-I detects and binds to foreign duplex RNA in the cytoplasm of both immune and non-immune cells, and initiates the induction of type I interferons and pro-inflammatory cytokines. The mechanism of RIG-I activation by double-stranded RNA (dsRNA) involves a molecular rearrangement proposed to expose the N-terminal pair of caspase activation recruitment domains, enabling an interaction with interferon-beta promoter stimulator 1 (IPS-1) and thereby initiating downstream signalling. dsRNA is particularly stimulatory when longer than 20 bp, potentially through allowing binding of more than one RIG-I molecule. Here, we characterize full-length RIG-I and RIG-I subdomains combined with a stimulatory 29mer dsRNA using multi-angle light scattering and size-exclusion chromatography-coupled small-angle X-ray scattering, to build up a molecular model of RIG-I before and after the formation of a 2:1 protein:dsRNA assembly. We report the small-angle X-ray scattering-derived solution structure of the human apo-RIG-I and observe that on binding of RIG-I to dsRNA in a 2:1 ratio, the complex becomes highly extended and flexible. Hence, here we present the first model of the fully activated oligomeric RIG-I.


Assuntos
Apoproteínas/química , RNA Helicases DEAD-box/química , RNA de Cadeia Dupla/química , Cromatografia em Gel , Proteína DEAD-box 58 , Humanos , Modelos Moleculares , Fragmentos de Peptídeos/química , Ligação Proteica , Estrutura Quaternária de Proteína , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Proteólise , Receptores Imunológicos , Espalhamento a Baixo Ângulo , Tripsina/química , Difração de Raios X
17.
EMBO J ; 29(10): 1762-73, 2010 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-20360684

RESUMO

Upon infection with many RNA viruses, the cytoplasmic retinoic acid inducible gene-I (RIG-I) pathway activates the latent transcription factor IRF-3, causing its nuclear translocation and the induction of many antiviral genes, including those encoding interferons. Here, we report a novel and distinct activity of IRF-3, in virus-infected cells, that induces apoptosis. Using genetically defective mouse and human cell lines, we demonstrated that, although both pathways required the presence of RIG-I, IPS1, TRAF3 and TBK1, only the apoptotic pathway required the presence of TRAF2 and TRAF6 in addition. More importantly, transcriptionally inactive IRF-3 mutants, such as the one missing its DNA-binding domain, could efficiently mediate apoptosis. Apoptosis was triggered by the direct interaction of IRF-3, through a newly identified BH3 domain, with the pro-apoptotic protein Bax, their co-translocation to the mitochondria and the resulting activation of the mitochondrial apoptotic pathway. Thus, IRF-3 is a dual-action cytoplasmic protein that, upon activation, translocates to the nucleus or to the mitochondrion and triggers two complementary antiviral responses of the infected cell.


Assuntos
Apoptose , Regulação Viral da Expressão Gênica , Fator Regulador 3 de Interferon/metabolismo , Proteína X Associada a bcl-2/metabolismo , Transporte Ativo do Núcleo Celular , Animais , Linhagem Celular , Citoplasma/metabolismo , Humanos , Camundongos , Transporte Proteico , RNA de Cadeia Dupla/metabolismo , Tretinoína/metabolismo
18.
Nucleic Acids Res ; 40(16): 8048-58, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22684508

RESUMO

Fine-tuning of inflammatory responses by microRNAs (miRNAs) is complex, as they can both enhance and repress expression of pro-inflammatory mediators. In this study, we investigate inflammatory responses following global miRNA depletion, to better define the overall contribution of miRNAs to inflammation. We demonstrate that miRNAs positively regulate Toll-like receptor signaling using inducible Dicer1 deletion and global miRNA depletion. We establish an important contribution of miR-19b in this effect, which potentiates nuclear factor-κB (NF-κB) activity in human and mouse cells. Positive regulation of NF-κB signaling by miR-19b involves the coordinated suppression of a regulon of negative regulators of NF-κB signaling (including A20/Tnfaip3, Rnf11, Fbxl11/Kdm2a and Zbtb16). Transfection of miR-19b mimics exacerbated the inflammatory activation of rheumatoid arthritis primary fibroblast-like synoviocytes, demonstrating its physiological importance in the pathology of this disease. This study constitutes, to our knowledge, the first description of a miR-19 regulon that controls NF-κB signaling, and suggests that targeting this miRNA and linked family members could regulate the activity of NF-κB signaling in inflammation.


Assuntos
MicroRNAs/metabolismo , NF-kappa B/metabolismo , Regulon , Transdução de Sinais , Animais , Células da Medula Óssea/metabolismo , Células Cultivadas , Fibroblastos/metabolismo , Humanos , Inflamação/genética , Mediadores da Inflamação/metabolismo , Macrófagos/metabolismo , Camundongos , Membrana Sinovial/citologia , Membrana Sinovial/metabolismo , Receptores Toll-Like/metabolismo
19.
Front Oncol ; 14: 1347694, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38525424

RESUMO

Pediatric high-grade gliomas (pHGG) are a rare yet devastating malignancy of the central nervous system's glial support cells, affecting children, adolescents, and young adults. Tumors of the central nervous system account for the leading cause of pediatric mortality of which high-grade gliomas present a significantly grim prognosis. While the past few decades have seen many pediatric cancers experiencing significant improvements in overall survival, the prospect of survival for patients diagnosed with pHGGs has conversely remained unchanged. This can be attributed in part to tumor heterogeneity and the existence of the blood-brain barrier. Advances in discovery research have substantiated the existence of unique subgroups of pHGGs displaying alternate responses to different therapeutics and varying degrees of overall survival. This highlights a necessity to approach discovery research and clinical management of the disease in an alternative subtype-dependent manner. This review covers traditional approaches to the therapeutic management of pHGGs, limitations of such methods and emerging alternatives. Novel mutations which predominate the pHGG landscape are highlighted and the therapeutic potential of targeting them in a subtype specific manner discussed. Collectively, this provides an insight into issues in need of transformative progress which arise during the management of pHGGs.

20.
Clin Cancer Res ; 30(2): 304-314, 2024 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-37976042

RESUMO

PURPOSE: We assessed the safety and efficacy of an EGFR-targeted, super-cytotoxic drug, PNU-159682-packaged nanocells with α-galactosyl ceramide-packaged nanocells (E-EDV-D682/GC) in patients with advanced pancreatic ductal adenocarcinoma (PDAC) who had exhausted all treatment options. PATIENTS AND METHODS: ENG9 was a first-in-man, single-arm, open-label, phase I/IIa, dose-escalation clinical trial. Eligible patients had advanced PDAC, Eastern Cooperative Oncology Group status 0 to 1, and failed all treatments. Primary endpoints were safety and overall survival (OS). RESULTS: Of 25 enrolled patients, seven were withdrawn due to rapidly progressive disease and one patient withdrew consent. All 25 patients were assessed for toxicity, 24 patients were assessed for OS, which was also assessed for 17 patients completing one treatment cycle [evaluable subset (ES)]. Nineteen patients (76.0%) experienced at least one treatment-related adverse event (graded 1 to 2) resolving within hours. There were no safety concerns, dose reductions, patient withdrawal, or treatment-related deaths.Median OS (mOS) was 4.4 months; however, mOS of the 17 ES patients was 6.9 months [208 days; range, 83-591 days; 95.0% confidence interval (CI), 5.6-10.3 months] and mOS of seven patients who did not complete one cycle was 1.8 months (54 days; range, 21-72; 95.0% CI, 1.2-2.2 months). Of the ES, 47.1% achieved stable disease and one partial response. Ten subjects in the ES survived over 6 months, the longest 19.7 months. During treatments, 82.0% of the ES maintained stable weight. CONCLUSIONS: E-EDV-D682/GC provided significant OS, minimal side effects, and weight stabilization in patients with advanced PDAC. Advanced PDAC can be safely treated with super-cytotoxic drugs via EnGeneIC Dream Vectors to overcome multidrug resistance.


Assuntos
Adenocarcinoma , Antineoplásicos , Neoplasias Pancreáticas , Humanos , Adenocarcinoma/patologia , Antineoplásicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Receptores ErbB/genética , Neoplasias Pancreáticas/patologia
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