Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Nat Commun ; 12(1): 2419, 2021 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-33893298

RESUMO

Chronic inflammation can drive tumor development. Here, we have identified microRNA-146a (miR-146a) as a major negative regulator of colonic inflammation and associated tumorigenesis by modulating IL-17 responses. MiR-146a-deficient mice are susceptible to both colitis-associated and sporadic colorectal cancer (CRC), presenting with enhanced tumorigenic IL-17 signaling. Within myeloid cells, miR-146a targets RIPK2, a NOD2 signaling intermediate, to limit myeloid cell-derived IL-17-inducing cytokines and restrict colonic IL-17. Accordingly, myeloid-specific miR-146a deletion promotes CRC. Moreover, within intestinal epithelial cells (IECs), miR-146a targets TRAF6, an IL-17R signaling intermediate, to restrict IEC responsiveness to IL-17. MiR-146a within IECs further suppresses CRC by targeting PTGES2, a PGE2 synthesis enzyme. IEC-specific miR-146a deletion therefore promotes CRC. Importantly, preclinical administration of miR-146a mimic, or small molecule inhibition of the miR-146a targets, TRAF6 and RIPK2, ameliorates colonic inflammation and CRC. MiR-146a overexpression or miR-146a target inhibition represent therapeutic approaches that limit pathways converging on tumorigenic IL-17 signaling in CRC.


Assuntos
Carcinogênese/genética , Neoplasias Colorretais/genética , Inflamação/genética , MicroRNAs/genética , Animais , Células Cultivadas , Colite/genética , Colite/metabolismo , Colite/patologia , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Regulação Neoplásica da Expressão Gênica , Humanos , Interleucina-17/genética , Interleucina-17/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Proteína Serina-Treonina Quinase 2 de Interação com Receptor/genética , Proteína Serina-Treonina Quinase 2 de Interação com Receptor/metabolismo , Transdução de Sinais/genética , Fator 6 Associado a Receptor de TNF/genética , Fator 6 Associado a Receptor de TNF/metabolismo
2.
iScience ; 24(4): 102356, 2021 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-33898947

RESUMO

Splenic Ly6Chigh monocytes are innate immune cells involved in the regulation of central nervous system-related diseases. Recent studies have reported the shaping of peripheral immune responses by the gut microbiome via mostly unexplored pathways. In this study, we report that a 4-day antibiotic treatment eliminates certain families of the Bacteroidetes, Firmicutes, Tenericutes, and Actinobacteria phyla in the gut and reduces the levels of multiple pattern recognition receptor (PRR) ligands in the serum. Reduction of PRR ligands was associated with reduced numbers and perturbed function of splenic Ly6Chigh monocytes, which acquired an immature phenotype producing decreased levels of inflammatory cytokines and exhibiting increased phagocytic and anti-microbial abilities. Addition of PRR ligands in antibiotic-treated mice restored the number and functions of splenic Ly6Chigh monocytes. Our data identify circulating PRR ligands as critical regulators of the splenic Ly6Chigh monocyte behavior and suggest possible intervention pathways to manipulate this crucial immune cell subset.

3.
Polymers (Basel) ; 13(7)2021 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-33805240

RESUMO

The non-toxic inorganic antimicrobial agents iodine (I2) and copper (Cu) are interesting alternatives for biocidal applications. Iodine is broad-spectrum antimicrobial agent but its use is overshadowed by compound instability, uncontrolled iodine release and short-term effectiveness. These disadvantages can be reduced by forming complex-stabilized, polymeric polyiodides. In a facile, in-vitro synthesis we prepared the copper-pentaiodide complex [Cu(H2O)6(12-crown-4)5]I6 · 2I2, investigated its structure and antimicrobial properties. The chemical structure of the compound has been verified. We used agar well and disc-diffusion method assays against nine microbial reference strains in comparison to common antibiotics. The stable complex revealed excellent inhibition zones against C. albicans WDCM 00054, and strong antibacterial activities against several pathogens. [Cu(H2O)6(12-crown-4)5]I6 · 2I2 is a strong antimicrobial agent with an interesting crystal structure consisting of complexes located on an inversion center and surrounded by six 12-crown-4 molecules forming a cationic substructure. The six 12-crown-4 molecules form hydrogen bonds with the central Cu(H2O)6. The anionic substructure is a halogen bonded polymer which is formed by formal I5- repetition units. The topology of this chain-type polyiodide is unique. The I5- repetition units can be understood as a triodide anion connected to two iodine molecules.

5.
Sci Rep ; 10(1): 12405, 2020 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-32709905

RESUMO

MOG-antibody associated disease (MOG-AAD) is a recently recognized demyelinating disorder predominantly affecting children but also occurs in adults, with a relapsing course in approximately 50% of patients. We evaluated peripheral blood mononuclear cells from MOG-AAD patients by flow cytometry and found a strong antigen specific central memory cell (CMC) response with increased Th1 and Th17 cells at the time of a relapse. Transcriptomic analysis of CMCs by three independent sequencing platforms revealed TNFAIP3 as a relapse biomarker, whose expression was down regulated at a relapse compared to remission in MOG-AAD patients. Serum in an additional cohort of patients showed decreased TNFAIP3 levels at relapse compared to remission state in MOG-AAD patients. Our studies suggest that alterations in TNFAIP3 levels are associated with relapses in MOG-AAD patients, which may have clinical utility as a disease course biomarker and therapeutic target.


Assuntos
Doenças Desmielinizantes/tratamento farmacológico , Doenças Desmielinizantes/metabolismo , Terapia de Alvo Molecular , Glicoproteína Mielina-Oligodendrócito/metabolismo , Proteína 3 Induzida por Fator de Necrose Tumoral alfa/metabolismo , Adulto , Biomarcadores/metabolismo , Criança , Doenças Desmielinizantes/imunologia , Feminino , Regulação da Expressão Gênica , Humanos , Interferon gama/metabolismo , Interleucina-17/metabolismo , Masculino , Recidiva , Células Th17/citologia , Células Th17/metabolismo , Proteína 3 Induzida por Fator de Necrose Tumoral alfa/genética
6.
Genome Biol ; 21(1): 33, 2020 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-32039742

RESUMO

BACKGROUND: Quiescence (G0) is a transient, cell cycle-arrested state. By entering G0, cancer cells survive unfavorable conditions such as chemotherapy and cause relapse. While G0 cells have been studied at the transcriptome level, how post-transcriptional regulation contributes to their chemoresistance remains unknown. RESULTS: We induce chemoresistant and G0 leukemic cells by serum starvation or chemotherapy treatment. To study post-transcriptional regulation in G0 leukemic cells, we systematically analyzed their transcriptome, translatome, and proteome. We find that our resistant G0 cells recapitulate gene expression profiles of in vivo chemoresistant leukemic and G0 models. In G0 cells, canonical translation initiation is inhibited; yet we find that inflammatory genes are highly translated, indicating alternative post-transcriptional regulation. Importantly, AU-rich elements (AREs) are significantly enriched in the upregulated G0 translatome and transcriptome. Mechanistically, we find the stress-responsive p38 MAPK-MK2 signaling pathway stabilizes ARE mRNAs by phosphorylation and inactivation of mRNA decay factor, Tristetraprolin (TTP) in G0. This permits expression of ARE mRNAs that promote chemoresistance. Conversely, inhibition of TTP phosphorylation by p38 MAPK inhibitors and non-phosphorylatable TTP mutant decreases ARE-bearing TNFα and DUSP1 mRNAs and sensitizes leukemic cells to chemotherapy. Furthermore, co-inhibiting p38 MAPK and TNFα prior to or along with chemotherapy substantially reduces chemoresistance in primary leukemic cells ex vivo and in vivo. CONCLUSIONS: These studies uncover post-transcriptional regulation underlying chemoresistance in leukemia. Our data reveal the p38 MAPK-MK2-TTP axis as a key regulator of expression of ARE-bearing mRNAs that promote chemoresistance. By disrupting this pathway, we develop an effective combination therapy against chemosurvival.


Assuntos
Elementos Ricos em Adenilato e Uridilato , Resistencia a Medicamentos Antineoplásicos , Processamento Pós-Transcricional do RNA , Tristetraprolina/metabolismo , Animais , Ciclo Celular , Células Cultivadas , Fosfatase 1 de Especificidade Dupla/genética , Fosfatase 1 de Especificidade Dupla/metabolismo , Células Hep G2 , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Células K562 , Células MCF-7 , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteoma/genética , Proteoma/metabolismo , Células THP-1 , Transcriptoma , Tristetraprolina/genética , Fator de Necrose Tumoral alfa/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/genética , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
7.
Cell Rep ; 28(13): 3353-3366.e5, 2019 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-31553906

RESUMO

Smad7, a negative regulator of TGF-ß signaling, has been implicated in the pathogenesis and treatment of inflammatory bowel diseases (IBDs), including Crohn's disease (CD) and ulcerative colitis (UC). Here, we found that Smad7 mediates intestinal inflammation by limiting the PDL2/1-PD1 axis in dendritic cells (DCs) and CD4+T cells. Smad7 deficiency in DCs promotes TGF-ß responsiveness and the co-inhibitory molecules PDL2/1 on DCs, and it further imprints T cell-PD1 signaling to promote Treg differentiation. DC-specific Smad7 deletion mitigates DSS-induced colitis by inducing CD103+PDL2/1+DCs and Tregs. In addition, Smad7 deficiency in CD4+T cells promotes PD1 and PD1-induced Tregs in vitro. The transfer of Smad7-deficient CD4+T cells enhances Tregs in vivo and protects against T cell-mediated colitis. Furthermore, Smad7 antisense ameliorates DSS-induced UC, increasing TGF-ß and PDL2/1-PD1 signaling. Enhancing PD1 signaling directly via Fc-fused PDL2/1 is also beneficial. Our results identify how Smad7 mediates intestinal inflammation and leverages these pathways therapeutically, providing additional strategies for IBD intervention.


Assuntos
Autoimunidade/genética , Inflamação/genética , Intestinos/patologia , Proteína Smad7/genética , Humanos , Transdução de Sinais
9.
Mult Scler ; 25(1): 63-71, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-29106333

RESUMO

BACKGROUND: Dimethyl fumarate (DMF) and its active metabolite monomethyl fumarate (MMF) effectively lead to reduction in disease relapses and active magnetic resonance imaging (MRI) lesions. DMF and MMF are known to be effective in modulating T- and B-cell responses; however, their effect on the phenotype and function of human myeloid dendritic cells (mDCs) is not fully understood. OBJECTIVE: To investigate the role of MMF on human mDCs maturation and function. METHODS: mDCs from healthy controls were isolated and cultured in vitro with MMF. The effect of MMF on mDC gene expression was determined by polymerase chain reaction (PCR) array after in vitro MMF treatment. The ability of mDCs to activate T cells was assessed by in vitro co-culture system. mDCs from DMF-treated multiple sclerosis (MS) patients were analyzed by flow cytometry and PCR. RESULTS: MMF treatment induced a less mature phenotype of mDCs with reduced expression of major histocompatibility complex class II (MHC-II), co-stimulatory molecules CD86, CD40, CD83, and expression of nuclear factor κB (NF-κB) subunits RELA and RELB. mDCs from DMF-treated MS patients also showed the same immature phenotype. T cells co-cultured with MMF-treated mDCs showed reduced proliferation with decreased production of interferon gamma (IFN-γ), interleukin-17 (IL-17), and granulocyte-macrophage colony-stimulating factor (GM-CSF) compared to untreated cells. CONCLUSION: We report that MMF can modulate immune response by affecting human mDC function.


Assuntos
Células Dendríticas/efeitos dos fármacos , Fumarato de Dimetilo/farmacologia , Fumaratos/farmacologia , Fatores Imunológicos/farmacologia , Esclerose Múltipla Recidivante-Remitente/sangue , Esclerose Múltipla Recidivante-Remitente/tratamento farmacológico , Células Mieloides/efeitos dos fármacos , Linfócitos T/efeitos dos fármacos , Humanos
10.
Neurol Neuroimmunol Neuroinflamm ; 5(5): e491, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30175165

RESUMO

Objective: To identify circulating microRNAs (miRNAs) linked to disease, disease stage, and disability in MS across cohorts. Methods: Samples were obtained from the Comprehensive Longitudinal Investigation of Multiple Sclerosis (CLIMB, Boston, MA), EPIC (San Francisco, CA), AMIR (Beirut, Lebanon) as part of the SUMMIT consortium, and Stockholm Prospective Assessment of Multiple Sclerosis (Stockholm, Sweden) cohorts. Serum miRNA expression was measured using locked nucleic acid-based quantitative PCR. Four groups were compared: (1) MS vs healthy control (HC), (2) relapsing-remitting (RR) vs HC, (3) secondary progressive (SP) vs HC, and (4) RR vs SP. A Wilcoxon rank-sum test was used for the comparisons. The association between each miRNA and the Expanded Disability Status Scale (EDSS) score was assessed using the Spearman correlation coefficient. For each comparison, the p values were corrected for multiple comparisons using the approach of Benjamini and Hochberg to control the false discovery rate. Results: In the CLIMB cohort, 5 miRNAs (hsa-miR-484, hsa-miR-140-5p, hsa-miR-320a, hsa-miR-486-5p, and hsa-miR-320c) showed a significant difference between patients with MS and healthy individuals; among these, miR-484 remained significant after accounting for multiple comparisons (p = 0.01). When comparing RRMS with HCs, hsa-miR-484 showed a significant difference (p = 0.004) between the groups after accounting for multiple group comparisons. When SP and HC were compared, 6 miRNAs (hsa-miR-484, hsa-miR-140-5p, hsa-miR-142-5p, hsa-miR-320a, hsa-miR-320b, and hsa-miR-320c) remained significantly different after accounting for multiple comparisons. Disability correlation analysis with miRNA provided 4 miRNAs (hsa-miR-320a, hsa-miR-337-3p, hsa-miR-199a-5p, and hsa-miR-142-5p) that correlated with the EDSS during the internal reproducibility phase. Among these, hsa-miR-337-3p was the most statistically significant miRNA that negatively correlated with the EDSS in three of the MS cohorts tested. Conclusions: These findings further confirm the use of circulating serum miRNAs as biomarkers to diagnose and monitor disease status in MS. Classification of evidence: This study provides Class III evidence that levels of circulating miRNAs identify patients with MS.

11.
Muscle Nerve ; 58(2): 261-269, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29466830

RESUMO

INTRODUCTION: Amyotrophic lateral sclerosis (ALS) is a debilitating neurologic disorder with poor survival rates and no clear biomarkers for disease diagnosis and prognosis. METHODS: We compared serum microRNA (miRNA) expression from patients with ALS with healthy controls and patients with multiple sclerosis and Alzheimer disease. We also correlated miRNA expression in cross-sectional and longitudinal cohorts of ALS patients with clinical parameters. RESULTS: We identified 7 miRNAs (miR-192-5p, miR-192-3p, miR-1, miR-133a-3p, miR-133b, miR-144-5p, miR-19a-3p) that were upregulated and 6 miRNAs (miR-320c, miR-320a, let-7d-3p, miR-425-5p, miR-320b, miR-139-5p) that were downregulated in patients with ALS compared with healthy controls, patients with Alzheimer disease, and patients with multiple sclerosis. Changes in 4 miRNAs (miR-136-3p, miR-30b-5p, miR-331-3p, miR-496) correlated positively and change in 1 miRNA (miR-2110) correlated negatively with changes in clinical parameters in longitudinal analysis. DISCUSSION: Our findings identified serum miRNAs that can serve as biomarkers for ALS diagnosis and progression. Muscle Nerve 58: 261-269, 2018.


Assuntos
Esclerose Amiotrófica Lateral/sangue , Esclerose Amiotrófica Lateral/fisiopatologia , MicroRNAs/sangue , Adulto , Doença de Alzheimer/sangue , Doença de Alzheimer/fisiopatologia , Biomarcadores/sangue , Estudos de Coortes , Estudos Transversais , Progressão da Doença , Feminino , Regulação da Expressão Gênica , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/sangue , Esclerose Múltipla/fisiopatologia
12.
JAMA Neurol ; 74(3): 275-285, 2017 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-28114622

RESUMO

Importance: MicroRNAs (miRNAs) are promising multiple sclerosis (MS) biomarkers. Establishing the association between miRNAs and magnetic resonance imaging (MRI) measures of disease severity will help define their significance and potential impact. Objective: To correlate circulating miRNAs in the serum of patients with MS to brain and spinal MRI. Design, Setting, and Participants: A cross-sectional study comparing serum miRNA samples with MRI metrics was conducted at a tertiary MS referral center. Two independent cohorts (41 and 79 patients) were retrospectively identified from the Comprehensive Longitudinal Investigation of Multiple Sclerosis at the Brigham and Women's Hospital. Expression of miRNA was determined by locked nucleic acid-based quantitative real-time polymerase chain reaction. Spearman correlation coefficients were used to test the association between miRNA and brain lesions (T2 hyperintense lesion volume [T2LV]), the ratio of T1 hypointense lesion volume [T1LV] to T2LV [T1:T2]), brain atrophy (whole brain and gray matter), and cervical spinal cord lesions (T2LV) and atrophy. The study was conducted from December 2013 to April 2016. Main Outcomes and Measures: miRNA expression. Results: Of the 120 patients included in the study, cohort 1 included 41 participants (7 [17.1%] men), with mean (SD) age of 47.7 (9.5) years; cohort 2 had 79 participants (26 [32.9%] men) with a mean (SD) age of 43.0 (7.5) years. Associations between miRNAs and MRIs were both protective and pathogenic. Regarding miRNA signatures, a topographic specificity differed for the brain vs the spinal cord, and the signature differed between T2LV and atrophy/destructive measures. Four miRNAs showed similar significant protective correlations with T1:T2 in both cohorts, with the highest for hsa.miR.143.3p (cohort 1: Spearman correlation coefficient rs = -0.452, P = .003; cohort 2: rs = -0.225, P = .046); the others included hsa.miR.142.5p (cohort 1: rs = -0.424, P = .006; cohort 2: rs = -0.226, P = .045), hsa.miR.181c.3p (cohort 1: rs = -0.383, P = .01; cohort 2: rs = -0.222, P = .049), and hsa.miR.181c.5p (cohort 1: rs = -0.433, P = .005; cohort 2: rs = -0.231, P = .04). In the 2 cohorts, hsa.miR.486.5p (cohort 1: rs = 0.348, P = .03; cohort 2: rs = 0.254, P = .02) and hsa.miR.92a.3p (cohort 1: rs = 0.392, P = .01; cohort 2: rs = 0.222, P = .049) showed similar significant pathogenic correlations with T1:T2; hsa.miR.375 (cohort 1: rs = -0.345, P = .03; cohort 2: rs = -0.257, P = .022) and hsa.miR.629.5p (cohort 1: rs = -0.350, P = .03; cohort 2: rs = -0.269, P = .02) showed significant pathogenic correlations with brain atrophy. Although we found several miRNAs associated with MRI outcomes, none of these associations remained significant when correcting for multiple comparisons, suggesting that further validation of our findings is needed. Conclusions and Relevance: Serum miRNAs may serve as MS biomarkers for monitoring disease progression and act as surrogate markers to identify underlying disease processes.


Assuntos
Imageamento por Ressonância Magnética , MicroRNAs/sangue , Esclerose Múltipla/sangue , Esclerose Múltipla/tratamento farmacológico , Adolescente , Adulto , Atrofia/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Estudos de Coortes , Avaliação da Deficiência , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , MicroRNAs/genética , Pessoa de Meia-Idade , RNA Mensageiro/sangue , Reprodutibilidade dos Testes , Índice de Gravidade de Doença , Medula Espinal/diagnóstico por imagem , Medula Espinal/patologia , Estatísticas não Paramétricas , Adulto Jovem
13.
Neurol Neuroimmunol Neuroinflamm ; 3(5): e267, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27606352

RESUMO

OBJECTIVE: To identify circulating microRNAs (miRNAs) linked to disease stage and disability in multiple sclerosis (MS). METHODS: Sera from 296 participants including patients with MS, other neurologic diseases (Alzheimer disease and amyotrophic lateral sclerosis), and inflammatory diseases (rheumatoid arthritis and asthma) and healthy controls (HCs) were tested. miRNA profiles were determined using LNA (locked nucleic acid)-based quantitative PCR. Patients with MS were categorized according to disease stage and disability. In the discovery phase, 652 miRNAs were measured in sera from 26 patients with MS and 20 HCs. Following this, significant miRNAs (p < 0.05) from the discovery set were validated using quantitative PCR in 58 patients with MS, 30 HCs, and in 74 samples from other disease controls (Alzheimer disease, amyotrophic lateral sclerosis, asthma, and rheumatoid arthritis). RESULTS: We validated 7 miRNAs that differentiate patients with MS from HCs (p < 0.05 in both the discovery and validation phase); miR-320a upregulation was the most significantly changing serum miRNA in patients with MS. We also identified 2 miRNAs linked to disease progression, with miR-27a-3p being the most significant. Ten miRNAs correlated with the Expanded Disability Status Scale of which miR.199a.5p had the strongest correlation with disability. Of the 15 unique miRNAs we identified in the different group comparisons, 12 have previously been reported to be associated with MS but not in serum. CONCLUSIONS: Our findings identify circulating serum miRNAs as potential biomarkers to diagnose and monitor disease status in MS. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that circulating serum miRNAs can be used as biomarker for MS.

15.
J Neuroinflammation ; 12: 245, 2015 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-26714756

RESUMO

BACKGROUND: Fingolimod (FTY720), the first oral treatment for multiple sclerosis (MS), blocks immune cell trafficking and prevents disease relapses by downregulation of sphingosine-1-phosphate receptor. We determined the effect of FTY720 on human T cell activation and effector function. METHODS: T cells from MS patients and healthy controls were isolated to measure gene expression profiles in the presence or absence of FTY720 using nanostring and quantitative real-time polymerase chain reaction (qPCR). Cytokine protein expression was measured using luminex assay and flow cytometry analysis. Lentivirus vector carrying short hairpin RNA (shRNA) was used to knock down the expression of specific genes in CD4+ T cells. Chromatin immunoprecipitation was performed to assess T cell factor 1 (TCF-1) binding to promoter regions. Luciferase assays were performed to test the direct regulation of interferon gamma (IFN-γ) and granzyme B (GZMB) by TCF-1. Western blot analysis was used to assess the phosphorylation status of Akt and GSK3ß. RESULTS: We showed that FTY720 treatment not only affects T cell trafficking but also T cell activation. Patients treated with FTY720 showed a significant reduction in circulating CD4 T cells. Activation of T cells in presence of FTY720 showed a less inflammatory phenotype with reduced production of IFN-γ and GZMB. This decreased effector phenotype of FTY720-treated T cells was dependent on the upregulation of TCF-1. FTY720-induced TCF-1 downregulated the pathogenic cytokines IFN-γ and GZMB by binding to their promoter/enhancer regions and mediating epigenetic modifications. Furthermore, we observed that TCF-1 expression was lower in T cells from multiple sclerosis patients than in those from healthy individuals, and FTY720 treatment increased TCF-1 expression in multiple sclerosis patients. CONCLUSIONS: These results reveal a previously unknown mechanism of the effect of FTY720 on human CD4+ T cell modulation in multiple sclerosis and demonstrate the role of TCF-1 in human T cell activation and effector function.


Assuntos
Linfócitos T CD4-Positivos/metabolismo , Cloridrato de Fingolimode/farmacologia , Imunossupressores/farmacologia , Esclerose Múltipla/metabolismo , Fator 1 de Transcrição de Linfócitos T/biossíntese , Regulação para Cima/fisiologia , Linfócitos T CD4-Positivos/efeitos dos fármacos , Feminino , Cloridrato de Fingolimode/uso terapêutico , Humanos , Imunossupressores/uso terapêutico , Masculino , Esclerose Múltipla/tratamento farmacológico , Regulação para Cima/efeitos dos fármacos
16.
Nat Genet ; 46(6): 588-94, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24793136

RESUMO

Coordinate control of different classes of cyclins is fundamentally important for cell cycle regulation and tumor suppression, yet the underlying mechanisms are incompletely understood. Here we show that the PARK2 tumor suppressor mediates this coordination. The PARK2 E3 ubiquitin ligase coordinately controls the stability of both cyclin D and cyclin E. Analysis of approximately 5,000 tumor genomes shows that PARK2 is a very frequently deleted gene in human cancer and uncovers a striking pattern of mutual exclusivity between PARK2 deletion and amplification of CCND1, CCNE1 or CDK4-implicating these genes in a common pathway. Inactivation of PARK2 results in the accumulation of cyclin D and acceleration of cell cycle progression. Furthermore, PARK2 is a component of a new class of cullin-RING-containing ubiquitin ligases targeting both cyclin D and cyclin E for degradation. Thus, PARK2 regulates cyclin-CDK complexes, as does the CDK inhibitor p16, but acts as a master regulator of the stability of G1/S cyclins.


Assuntos
Ciclo Celular , Ciclina D1/metabolismo , Ciclina E/metabolismo , Quinase 4 Dependente de Ciclina/metabolismo , Regulação Neoplásica da Expressão Gênica , Proteínas Oncogênicas/metabolismo , Ubiquitina-Proteína Ligases/genética , Animais , Linhagem Celular Tumoral , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Fase G1 , Deleção de Genes , Perfilação da Expressão Gênica , Genes Supressores de Tumor , Genoma Humano , Genômica , Humanos , Insetos , RNA Interferente Pequeno/metabolismo , Fase S
17.
Biochem J ; 458(3): 537-45, 2014 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-24393003

RESUMO

Mutation of the TRIM (tripartite motif)-NHL family members brat and mei-P26 perturb the differentiation of transit-amplifying progenitor cells resulting in tumour-like phenotypes. The NHL (named after the NCL1, HT2A and LIN41 repeat) domain is essential for their growth suppressive activity, and they can induce cell-cycle exit in a RING-independent manner. TRIM3 is the only bona fide tumour suppressor in the mammalian TRIM-NHL subfamily and similar to the other members of this family, its ability to inhibit cell proliferation depends on the NHL domain. However, whether the RING domain was required for TRIM3-dependent cell-cycle exit had not been investigated. In the present study, we establish that the RING domain is required for TRIM3-induced growth suppression. Furthermore, we show that this domain is necessary to promote ubiquitination of p21 in a reconstituted in vitro system where UbcH5a is the preferred E2. Thus the ability of TRIM3 to suppress growth is associated with its ability to ubiquitinate proteins.


Assuntos
Proteínas de Transporte/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Animais , Proteínas de Transporte/genética , Linhagem Celular Tumoral , Proliferação de Células , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Humanos , Camundongos , Mutação , Estrutura Terciária de Proteína , Enzimas de Conjugação de Ubiquitina/metabolismo , Ubiquitinação
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...