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1.
J Exp Med ; 221(6)2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38563819

RESUMO

The outcome of cancer and autoimmunity is often dictated by the effector functions of CD4+ conventional T cells (Tconv). Although activation of the NF-κB signaling pathway has long been implicated in Tconv biology, the cell-autonomous roles of the separate NF-κB transcription-factor subunits are unknown. Here, we dissected the contributions of the canonical NF-κB subunits RelA and c-Rel to Tconv function. RelA, rather than c-Rel, regulated Tconv activation and cytokine production at steady-state and was required for polarization toward the TH17 lineage in vitro. Accordingly, RelA-deficient mice were fully protected against neuroinflammation in a model of multiple sclerosis due to defective transition to a pathogenic TH17 gene-expression program. Conversely, Tconv-restricted ablation of c-Rel impaired their function in the microenvironment of transplanted tumors, resulting in enhanced cancer burden. Moreover, Tconv required c-Rel for the response to PD-1-blockade therapy. Our data reveal distinct roles for canonical NF-κB subunits in different disease contexts, paving the way for subunit-targeted immunotherapies.


Assuntos
Esclerose Múltipla , Neoplasias , Animais , Camundongos , Linfócitos T CD4-Positivos , NF-kappa B , Transdução de Sinais , Microambiente Tumoral , Proteínas Proto-Oncogênicas c-rel/metabolismo
2.
Sci Rep ; 13(1): 19614, 2023 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-37950057

RESUMO

Ras guanine nucleotide exchange factor member 1b (RasGEF1b) of the RasGEF/CDC25 domain-containing family is preferentially expressed by macrophages. However, information is lacking about its role in macrophage function. In this study, we generated mice with ubiquitous deletion of Rasgef1b and used RNA-seq-based transcriptomics to compare the global gene expression in wild-type and knock-out primary bone-marrow-derived macrophages under basal conditions and after lipopolysaccharide (LPS) treatment. Transcriptional filtering identified several genes with significantly different transcript levels between wild-type and knock-out macrophages. In total, 49 and 37 differentially expressed genes were identified at baseline and in LPS-activated macrophages, respectively. Distinct biological processes were significantly linked to down-regulated genes at the basal condition only, and largely included chemotaxis, response to cytokines, and positive regulation of GTPase activity. Importantly, validation by RT-qPCR revealed that the expression of genes identified as down-regulated after LPS stimulation was also decreased in the knock-out cells under basal conditions. We used a luciferase-based reporter assay to showcase the capability of RasGEF1b in activating the Serpinb2 promoter. Notably, knockdown of RasGEF1b in RAW264.7 macrophages resulted in impaired transcriptional activation of the Serpinb2 promoter, both in constitutive and LPS-stimulated conditions. This study provides a small collection of genes that shows relative expression changes effected by the absence of RasGEF1b in macrophages. Thus, we present the first evidence that RasGEF1b mediates the regulation of both steady-state and signal-dependent expression of genes and propose that this GEF plays a role in the maintenance of the basal transcriptional level in macrophages.


Assuntos
Citocinas , Lipopolissacarídeos , Animais , Camundongos , Quimiotaxia , Citocinas/genética , Citocinas/metabolismo , Lipopolissacarídeos/farmacologia , Lipopolissacarídeos/metabolismo , Macrófagos/metabolismo , Transcriptoma
3.
Proc Natl Acad Sci U S A ; 120(46): e2312595120, 2023 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-37931099

RESUMO

The NF-κB family of transcription factors and the Ras family of small GTPases are important mediators of proproliferative signaling that drives tumorigenesis and carcinogenesis. The κB-Ras proteins were previously shown to inhibit both NF-κB and Ras activation through independent mechanisms, implicating them as tumor suppressors with potentially broad relevance to human cancers. In this study, we have used two mouse models to establish the relevance of the κB-Ras proteins for tumorigenesis. Additionally, we have utilized a pan-cancer bioinformatics analysis to explore the role of the κB-Ras proteins in human cancers. Surprisingly, we find that the genes encoding κB-Ras 1 (NKIRAS1) and κB-Ras 2 (NKIRAS2) are rarely down-regulated in tumor samples with oncogenic Ras mutations. Reduced expression of human NKIRAS1 alone is associated with worse prognosis in at least four cancer types and linked to a network of genes implicated in tumorigenesis. Our findings provide direct evidence that loss of NKIRAS1 in human tumors that do not carry oncogenic RAS mutations is associated with worse clinical outcomes.


Assuntos
Carcinogênese , Proteínas de Transporte , Genes Supressores de Tumor , Animais , Humanos , Camundongos , Carcinogênese/genética , Transformação Celular Neoplásica/genética , Genes ras , NF-kappa B/metabolismo , Proteínas ras/metabolismo , Proteínas de Transporte/genética
4.
Nat Immunol ; 24(8): 1256-1264, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37400674

RESUMO

Innate lymphoid cells (ILCs) can quickly switch from a quiescent state to an active state and rapidly produce effector molecules that provide critical early immune protection. How the post-transcriptional machinery processes different stimuli and initiates robust gene expression in ILCs is poorly understood. Here, we show that deletion of the N6-methyladenosine (m6A) writer protein METTL3 has little impact on ILC homeostasis or cytokine-induced ILC1 or ILC3 responses but significantly diminishes ILC2 proliferation, migration and effector cytokine production and results in impaired antihelminth immunity. m6A RNA modification supports an increase in cell size and transcriptional activity in activated ILC2s but not in ILC1s or ILC3s. Among other transcripts, the gene encoding the transcription factor GATA3 is highly m6A methylated in ILC2s. Targeted m6A demethylation destabilizes nascent Gata3 mRNA and abolishes the upregulation of GATA3 and ILC2 activation. Our study suggests a lineage-specific requirement of m6A for ILC2 responses.


Assuntos
Imunidade Inata , Linfócitos , Citocinas/metabolismo , Homeostase , Imunidade Inata/genética , Imunidade Inata/imunologia , Linfócitos/imunologia , RNA/metabolismo , Animais , Camundongos
5.
Ecancermedicalscience ; 17: 1503, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37113717

RESUMO

Background: We investigated the role of DNA repair proteins breast cancer susceptibility 2 (BRCA2), xeroderma pigmentosum group D (XPD) and apurinic/apyrimidinic endodeoxyribonuclease 1 (APE1) in determining the risk for head and neck squamous cell cancer (HNSCC) in a case-control study from North-East India. Methods: Expression of BRCA2, XPD and APE1 genes in the matched tumour, normal adjacent tissue (NAT) and blood of 12 HNSCC patients and blood of 8 age- and gender-matched controls was determined by quantitative real-time PCR. Results were validated by expression analysis of the corresponding proteins in the peripheral blood lymphocytes (PBLs) of 228 subjects (106 patients and 122 controls) by a slot-blot immunoassay. Findings: Expression of the BRCA2 and XPD genes in tumour tissue of HNSCC patients declined progressively as the cancer stage advanced, was reverse that of the NAT, but was mirrored by the expression in the blood. BRCA2 and XPD proteins were significantly (p < 0.0001) downregulated in the PBL of HNSCC patients to 71% and 77% the levels in controls, showing significant negative correlation with HNSCC stage (Spearman correlation coefficient (r s) of -0.9060, p < 0.0001 for BRCA2; r s of -0.8008, p < 0.01 for XPD). On the contrary, APE1 was significantly upregulated in PBL of HNSCC patients to 1.47 fold the level in controls, showing significant positive correlation with HNSCC stage (r s of 0.7023, p < 0.01). Classification and regression tree analyses predicted low levels of BRCA2 protein in PBL as the single most important risk factor for HNSCC, independent of gender. Smokers above 36 years of age with low level of BRCA2 appeared to exhibit a 1.78-fold increased risk for HNSCC (with a 1.78-fold increased risk for HNSCC (OR = 1.78, 95% confidence interval (CI) = 0.33-9.52) though this risk was not significant statistically. Similarly, low levels of BRCA2 appeared to indicate a moderate, but non-significant risk for HNSCC in non-smokers aged between 36 and 56 years (OR = 1.15, 95% CI = 0.21-6.37). Conclusions: Low level of BRCA2 protein in the peripheral blood indicates increased risk for HNSCC.

6.
J Biomol Struct Dyn ; 41(6): 2090-2107, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-35037836

RESUMO

Head and neck cancer (HNC), the sixth most common cancer globally, stands first in India, especially Northeast India, where tobacco usage is predominant, which introduces various carcinogens leading to malignancies by accumulating DNA damages. Consequently, the present work aimed to predict the impact of significant germline variants in DNA repair and Tumour Suppressor genes on HNC development. WES in Ion ProtonTM platform on 'discovery set' (n = 15), followed by recurrence assessment of the observed variants on 'confirmation set' (n = 40) using Sanger Sequencing was performed on the HNC-prevalent NE Indian populations. Initially, 53 variants were identified, of which seven HNC-linked DNA damage response gene variants were frequent in the studied populations. Different tools ascertained the biological consequences of these variants, of which the non-coding variants viz. EXO1_rs4150018, RAD52_rs6413436, CHD5_rs2746066, HACE1_rs6918700 showed risk, while FLT3_rs2491227 and BMPR1A_rs7074064 conferred protection against HNC by affecting transcriptional regulation and splicing mechanism. Molecular Dynamics Simulation of the full-length p53 model predicted that the observed coding TP53_rs1042522 variant conferred HNC-risk by altering the structural dynamics of the protein, which displayed difficulty in the transition between active and inactive conformations due to high-energy barrier. Subsequent pathway and gene ontology analysis revealed that EXO1, RAD52 and TP53 variants affected the Double-Strand Break Repair pathway, whereas CHD5 and HACE1 variants inactivated DNA repair cascade, facilitating uncontrolled cell proliferation, impaired apoptosis and malignant transformation. Conversely, FLT3 and BMPR1A variants protected against HNC by controlling tumorigenesis, which requires experimental validation. These findings may serve as prognostic markers for developing preventive measures against HNC.


Assuntos
Predisposição Genética para Doença , Neoplasias de Cabeça e Pescoço , Humanos , Polimorfismo de Nucleotídeo Único , Reparo do DNA/genética , Neoplasias de Cabeça e Pescoço/genética , Dano ao DNA/genética , DNA Helicases/genética , Proteínas do Tecido Nervoso/genética , Ubiquitina-Proteína Ligases/genética
7.
Int J Mol Sci ; 23(24)2022 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-36555493

RESUMO

Long-read sequencing (LRS) has been adopted to meet a wide variety of research needs, ranging from the construction of novel transcriptome annotations to the rapid identification of emerging virus variants. Amongst other advantages, LRS preserves more information about RNA at the transcript level than conventional high-throughput sequencing, including far more accurate and quantitative records of splicing patterns. New studies with LRS datasets are being published at an exponential rate, generating a vast reservoir of information that can be leveraged to address a host of different research questions. However, mining such publicly available data in a tailored fashion is currently not easy, as the available software tools typically require familiarity with the command-line interface, which constitutes a significant obstacle to many researchers. Additionally, different research groups utilize different software packages to perform LRS analysis, which often prevents a direct comparison of published results across different studies. To address these challenges, we have developed the Long-Read Analysis Pipeline for Transcriptomics (L-RAPiT), a user-friendly, free pipeline requiring no dedicated computational resources or bioinformatics expertise. L-RAPiT can be implemented directly through Google Colaboratory, a system based on the open-source Jupyter notebook environment, and allows for the direct analysis of transcriptomic reads from Oxford Nanopore and PacBio LRS machines. This new pipeline enables the rapid, convenient, and standardized analysis of publicly available or newly generated LRS datasets.


Assuntos
Computação em Nuvem , RNA , RNA/genética , Perfilação da Expressão Gênica/métodos , Biologia Computacional/métodos , Software , Análise de Sequência de RNA , Sequenciamento de Nucleotídeos em Larga Escala/métodos
8.
Heredity (Edinb) ; 129(6): 346-355, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36319737

RESUMO

Cat domestication likely initiated as a symbiotic relationship between wildcats (Felis silvestris subspecies) and the peoples of developing agrarian societies in the Fertile Crescent. As humans transitioned from hunter-gatherers to farmers ~12,000 years ago, bold wildcats likely capitalized on increased prey density (i.e., rodents). Humans benefited from the cats' predation on these vermin. To refine the site(s) of cat domestication, over 1000 random-bred cats of primarily Eurasian descent were genotyped for single-nucleotide variants and short tandem repeats. The overall cat population structure suggested a single worldwide population with significant isolation by the distance of peripheral subpopulations. The cat population heterozygosity decreased as genetic distance from the proposed cat progenitor's (F.s. lybica) natural habitat increased. Domestic cat origins are focused in the eastern Mediterranean Basin, spreading to nearby islands, and southernly via the Levantine coast into the Nile Valley. Cat population diversity supports the migration patterns of humans and other symbiotic species.


Assuntos
Domesticação , Repetições de Microssatélites , Animais , Gatos/genética , Genótipo , Oriente Médio
9.
Nat Commun ; 13(1): 6869, 2022 11 11.
Artigo em Inglês | MEDLINE | ID: mdl-36369293

RESUMO

Although skeletal progenitors provide a reservoir for bone-forming osteoblasts, the major energy source for their osteogenesis remains unclear. Here, we demonstrate a requirement for mitochondrial oxidative phosphorylation in the osteogenic commitment and differentiation of skeletal progenitors. Deletion of Evolutionarily Conserved Signaling Intermediate in Toll pathways (ECSIT) in skeletal progenitors hinders bone formation and regeneration, resulting in skeletal deformity, defects in the bone marrow niche and spontaneous fractures followed by persistent nonunion. Upon skeletal fracture, Ecsit-deficient skeletal progenitors migrate to adjacent skeletal muscle causing muscle atrophy. These phenotypes are intrinsic to ECSIT function in skeletal progenitors, as little skeletal abnormalities were observed in mice lacking Ecsit in committed osteoprogenitors or mature osteoblasts. Mechanistically, Ecsit deletion in skeletal progenitors impairs mitochondrial complex assembly and mitochondrial oxidative phosphorylation and elevates glycolysis. ECSIT-associated skeletal phenotypes were reversed by in vivo reconstitution with wild-type ECSIT expression, but not a mutant displaying defective mitochondrial localization. Collectively, these findings identify mitochondrial oxidative phosphorylation as the prominent energy-driving force for osteogenesis of skeletal progenitors, governing musculoskeletal integrity.


Assuntos
Fosforilação Oxidativa , Células-Tronco , Camundongos , Animais , Células-Tronco/metabolismo , Transdução de Sinais , Osteogênese/genética , Diferenciação Celular , Estresse Oxidativo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo
10.
Adv Exp Med Biol ; 1363: 147-160, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35220569

RESUMO

Genome wide association studies (GWAS) have identified many loci contributing to genetic variation of complex traits. Immune mediated disorders are complex diseases for which hundreds of risk alleles have been identified by GWAS. However, the intergenic location of most of the signals has make it difficult to decipher their implication in disease pathogenesis. A significant number of immune disease-associated SNPs are located within long noncoding RNAs (lncRNAs). LncRNAs have gained importance due to their involvement in the regulation of a wide range of biological processes, including immune responses. GWAS SNPs located within lncRNAs can affect their regulatory capacity by modifying their secondary structure, altering their expression levels or regulating the transcription of different isoforms. In this review we discuss the functional implications of immune-related lncRNAs harboring disease associated SNPs on various disease conditions.


Assuntos
Estudo de Associação Genômica Ampla , RNA Longo não Codificante , Alelos , Predisposição Genética para Doença , Humanos , Polimorfismo de Nucleotídeo Único , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo
11.
Gene ; 812: 146099, 2022 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-34906645

RESUMO

Nasopharyngeal Carcinoma (NPC) found to be dependent on geographical and racial variation and is more prevalent in Northeast (NE) India. WES-based study was conducted in three states (tribes); Nagaland (Naga), Mizoram (Mizo) and Manipur (Manipuri), which provided an overview of germline variants involved inthemajor signaling pathways. Validation and recurrence assessment of WES data confirmed the risk effect of STEAP3_rs138941861 and JAG1_rs2273059, and the protective role of PARP4_rs17080653 and TGFBR1_rs11568778 variants, where STEAP3_rs138941861conferring Arg290His substitution was the only exonic non-synonymous variant and to be located in proximity to the linking region between the transmembrane and oxidoreductasedomainsof STEAP3 protein, andaffectedits structural and functional dynamics by altering the Electrostatic Potential around this connecting region. Moreover, these significantly associated variants having deleterious effect were observed to have interactions in p53 signaling pathway which emphasizes the importance of this pathway in the causation of NPC.


Assuntos
Proteínas de Ciclo Celular/genética , Sequenciamento do Exoma/métodos , Proteína Jagged-1/genética , Carcinoma Nasofaríngeo/genética , Neoplasias Nasofaríngeas/genética , Proteínas Nucleares/genética , Oxirredutases/genética , Receptor do Fator de Crescimento Transformador beta Tipo I/genética , Adulto , Substituição de Aminoácidos , Estudos de Casos e Controles , Proteínas de Ciclo Celular/química , Feminino , Predisposição Genética para Doença , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Índia , Masculino , Pessoa de Meia-Idade , Modelos Moleculares , Oxirredutases/química , Polimorfismo de Nucleotídeo Único , Conformação Proteica , Domínios Proteicos
12.
Gene ; 813: 146098, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-34952175

RESUMO

BACKGROUND: Northeast (NE) India is a subject of debate for predicting its involvement in prehistoric anatomically modern human (AMH) dispersal. The unique lifestyle and genetic characteristics of native ethnic groups in this region are believed to be responsible for their susceptibility to tobacco-related oral cancer (TrOC). The present study assessed mitochondrial macro-haplogroup (mHG) diversity and TrOC susceptibility autosomal loci to evaluate the impact of prehistoric AMH dispersal on the present day's high TrOC prevalence in major NE Indian ethnics. METHODS: We considered 175 unrelated individuals from 35 ethnic groups and previously published 374 sequences for sequencing-based assessment of mtDNA-based marker by subsequent analyses like haplogroup diversity, phylogenetic, genetic structure by AMOVA, and MDS, descriptive statistics of demographic parameters, and migration analysis. Besides, we selected prolonged tobacco-chewing 124 case-control individuals from similar ethnic backgrounds for genotyping 115 autosomal loci in Sequenom iPLEX MassARRAY™ platform and mined 1000genome data (n = 398) for consequent global admixture and ancestry-specific allele frequencies-based analyses. RESULTS: Our mtDNA-based findings suggested that NE populations were distinct from other Indian populations, owing to the first wave of migration from ancient southern China (∼54kya) and two successive spatial expansion events at âˆ¼45kya and âˆ¼43kya. Consequently, it probably acted as another source for prehistoric AMH dispersal in N/NE Asia. Besides, the second wave of back-migration from SE Asia (∼40kya) probably replaced the mitochondrial footprints of survivors from the first migrants and introduced the TrOC susceptibility traits in this region. Afterward, the autosomal marker-based observations on the transition of the disease-associated admixture component 'K6' from SE Asia reconfirmed these results. Moreover, we also observed that the mitochondrial mHG 'R' is significantly associated with the risk of TrOC (OR > 9.5) in NE India. Furthermore, the possible onset of the phenotypic expression of those traits was predicted at âˆ¼4kya, thus, contributing to present-day's TrOC prevalence. CONCLUSIONS: This study reflects its uniqueness by revealing an updated AMH dispersal route for the peopling in and out of NE India, which probably introduced the disease-causing traits in the ancestral NE Indian population. Those traits were then imprinted in their genome to get transferred through their respective generations, forming the present-day's TrOC-prevalent NE Indian population.


Assuntos
Neoplasias Bucais/epidemiologia , Uso de Tabaco/epidemiologia , Adulto , Povo Asiático/genética , Estudos de Casos e Controles , DNA Mitocondrial/genética , Etnicidade/genética , Feminino , Frequência do Gene , Predisposição Genética para Doença , Variação Genética , Genética Populacional/métodos , Haplótipos , Migração Humana , Humanos , Índia/epidemiologia , Masculino , Pessoa de Meia-Idade , Neoplasias Bucais/sangue , Neoplasias Bucais/etiologia , Neoplasias Bucais/genética , Filogenia , Fumar Tabaco , Uso de Tabaco/sangue , Uso de Tabaco/genética , Adulto Jovem
13.
Front Immunol ; 12: 741938, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34745114

RESUMO

T helper 17 (TH17) cells are involved in several autoimmune diseases such as multiple sclerosis (MS) and rheumatoid arthritis (RA). In addition to retinoic acid receptor-related orphan nuclear receptor gamma t (ROR-γt), hypoxia-inducible factor-1α (HIF-1α) is essential for the differentiation and inflammatory function of TH17 cells. To investigate the roles of HIF-1α in the functional regulation of TH17 cells under the normal physiological condition without genetic modification, the nucleus-transducible form of transcription modulation domain (TMD) of HIF-1α (ntHIF-1α-TMD) was generated by conjugating HIF-1α-TMD to Hph-1 protein transduction domain (PTD). ntHIF-1α-TMD was effectively delivered into the nucleus of T cells without cellular cytotoxicity. ntHIF-1α-TMD significantly blocked the differentiation of naïve T cells into TH17 cells in a dose-dependent manner via IL-17A and ROR-γt expression inhibition. However, T-cell activation events such as induction of CD69, CD25, and IL-2 and the differentiation potential of naïve T cells into TH1, TH2, or Treg cells were not affected by ntHIF-1α-TMD. Interestingly, TH17 cells differentiated from naïve T cells in the presence of ntHIF-1α-TMD showed a substantial level of suppressive activity toward the activated T cells, and the increase of Foxp3 and IL-10 expression was detected in these TH17 cells. When mRNA expression pattern was compared between TH17 cells and ntHIF-1α-TMD-treated TH17 cells, the expression of the genes involved in the differentiation and functions of TH17 cells was downregulated, and that of the genes necessary for immune-suppressive functions of Treg cells was upregulated. When the mice with experimental autoimmune encephalomyelitis (EAE) were treated with ntHIF-1α-TMD with anti-IL-17A mAb as a positive control, the therapeutic efficacy of ntHIF-1α-TMD in vivo was comparable with that of anti-IL-17A mAb, and ntHIF-1α-TMD-mediated therapeutic effect was contributed by the functional conversion of TH17 cells into immune-suppressive T cells. The results in this study demonstrate that ntHIF-1α-TMD can be a new therapeutic reagent for the treatment of various autoimmune diseases in which TH17 cells are dominant and pathogenic T cells.


Assuntos
Encefalomielite Autoimune Experimental/imunologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/imunologia , Células Th17/imunologia , Animais , Diferenciação Celular/imunologia , Feminino , Camundongos , Camundongos Endogâmicos C57BL
14.
Sci Rep ; 11(1): 19674, 2021 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-34608221

RESUMO

NF-kappaB (NF-κB) is a family of transcription factors with pleiotropic functions in immune responses. The alternative NF-κB pathway that leads to the activation of RelB and NF-κB2, was previously associated with the activation and function of T cells, though the exact contribution of these NF-κB subunits remains unclear. Here, using mice carrying conditional ablation of RelB in T cells, we evaluated its role in the development of conventional CD4+ T (Tconv) cells and their function in autoimmune diseases. RelB was largely dispensable for Tconv cell homeostasis, activation and proliferation, and for their polarization toward different flavors of Thelper cells in vitro. Moreover, ablation of RelB had no impact on the capacity of Tconv cells to induce autoimmune colitis. Conversely, clinical severity of experimental autoimmune encephalomyelitis (EAE), a mouse model of multiple sclerosis (MS) was significantly reduced in mice with RelB-deficient T cells. This was associated with impaired expression of granulocyte-macrophage colony-stimulating factor (GM-CSF) specifically in the central nervous system. Our data reveal a discrete role for RelB in the pathogenic function of Tconv cells during EAE, and highlight this transcription factor as a putative therapeutic target in MS.


Assuntos
Autoimunidade , Suscetibilidade a Doenças , Encefalomielite Autoimune Experimental/etiologia , Encefalomielite Autoimune Experimental/metabolismo , Linfócitos T/imunologia , Linfócitos T/metabolismo , Fator de Transcrição RelB/metabolismo , Animais , Biomarcadores , Colite/etiologia , Colite/metabolismo , Colite/patologia , Suscetibilidade a Doenças/imunologia , Encefalomielite Autoimune Experimental/patologia , Homeostase/imunologia , Ativação Linfocitária , Camundongos , Linfócitos T Auxiliares-Indutores/imunologia , Linfócitos T Auxiliares-Indutores/metabolismo
15.
Sci Rep ; 11(1): 18721, 2021 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-34548527

RESUMO

Metformin is a first-line drug in the treatment of type-2 diabetes mellitus (T2DM). In addition to its antigluconeogenic and insulin-sensitizing properties, metformin has emerged as a potent inhibitor of the chronic inflammatory response of macrophages. In particular, metformin treatment has been shown to reduce expression of interleukin (IL-) 1ß during long-term exposure to the pro-inflammatory stimulus lipopolysaccharide (LPS) through a reduction in reactive oxygen species (ROS), which decreases the levels of the hypoxia-inducible factor (HIF) 1-α, and through enhanced expression of IL-10. However, the effect of metformin on the acute inflammatory response, before significant levels of ROS accumulate in the cell, has not been explored. Here, we show that metformin alters the acute inflammatory response through its activation of AMP-activated protein kinase (AMPK), but independently of HIF1-α and IL-10, in primary macrophages and two macrophage-like cell lines. Thus, metformin changes the acute and the chronic inflammatory response through fundamentally distinct mechanisms. Furthermore, RNA-seq analysis reveals that metformin pretreatment affects the levels of a large yet selective subset of inflammatory genes, dampening the response to short-term LPS exposure and affecting a wide range of pathways and biological functions. Taken together, these findings reveal an unexpected complexity in the anti-inflammatory properties of this widely used drug.


Assuntos
Adenilato Quinase/metabolismo , Hipoglicemiantes/uso terapêutico , Inflamação/prevenção & controle , Metformina/uso terapêutico , Humanos , Hipoglicemiantes/farmacologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Interleucina-10/genética , Interleucina-1beta/genética , Lipopolissacarídeos/farmacologia , Metformina/farmacologia , NF-kappa B/genética , RNA Mensageiro/genética , Espécies Reativas de Oxigênio/metabolismo
16.
J Immunol ; 206(8): 1776-1783, 2021 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-33789982

RESUMO

Regulatory T (Treg) cells have an essential role in maintaining immune homeostasis, in part by suppressing effector T cell functions. Phosphoinositide-dependent kinase 1 (PDK1) is a pleiotropic kinase that acts as a key effector downstream of PI3K in many cell types. In T cells, PDK1 has been shown to be critical for activation of NF-κB and AKT signaling upon TCR ligation and is therefore essential for effector T cell activation, proliferation, and cytokine production. Using Treg cell-specific conditional deletion, we now demonstrate that PDK1 is also essential for Treg cell suppressive activity in vivo. Ablation of Pdk1 specifically in Treg cells led to systemic, lethal, scurfy-like inflammation in mice. Genome-wide analysis confirmed that PDK1 is essential for the regulation of key Treg cell signature gene expression and, further, suggested that PDK1 acts primarily to control Treg cell gene expression through regulation of the canonical NF-κB pathway. Consistent with these results, the scurfy-like phenotype of mice lacking PDK1 in Treg cells was rescued by enforced activation of NF-κB downstream of PDK1. Therefore, PDK1-mediated activation of the NF-κB signaling pathway is essential for regulation of Treg cell signature gene expression and suppressor function.


Assuntos
Proteínas Quinases Dependentes de 3-Fosfoinositídeo/metabolismo , Transtornos Linfoproliferativos/genética , Linfócitos T Reguladores/imunologia , Proteínas Quinases Dependentes de 3-Fosfoinositídeo/genética , Animais , Antígenos CD4/metabolismo , Proliferação de Células , Células Cultivadas , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Terapia de Imunossupressão , Ativação Linfocitária , Camundongos , Camundongos Knockout , NF-kappa B/metabolismo , Transdução de Sinais , Transcriptoma
17.
J Endocrinol ; 249(3): 163-175, 2021 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-33764312

RESUMO

The ß-cell response to injury may be as critical for the development of diabetes as the specific insult. In the current study, we used streptozotocin (STZ) to injure the ß-cell in order to study the response with a focus on NFκB. MIN6 cells were exposed to STZ (0.5-8 mM, 0-24h) ±TNFα (100 ng/mL) and ±IκBß siRNA to lower the threshold to NFκB activation. Cell viability was determined by trypan blue exclusion. NFκB activation was determined by the expression of the target genes Nos2 and Cxcl10, localization of the NFκB proteins p65 and p50, and expression and localization of the NFκB inhibitors, IκBß and IκBα. There was no NFκB activation in MIN6 cell exposed to STZ (2 mM) alone. However, knocking down IκBß expression using siRNA resulted in STZ-induced expression of NFκB target genes and increased cell death, while co-incubation with STZ and TNFα enhanced cell death compared to either exposure alone. Adult male IκBß-/- and WT mice were exposed to STZ and monitored for diabetes. The IκBß-/- mice developed hyperglycemia and diabetes more frequently than controls following STZ exposure. Based on these results we conclude that STZ exposure alone does not induce NFκB activity. However, lowering the threshold to NFκB activation by co-incubation with TNFα or lowering IκBß levels by siRNA sensitizes the NFκB response to STZ and results in a higher likelihood of developing diabetes in vivo. Therefore, increasing the threshold to NFκB activation through stabilizing NFκB inhibitory proteins may prevent ß-cell injury and the development of diabetes.


Assuntos
Células Secretoras de Insulina/efeitos dos fármacos , NF-kappa B/metabolismo , Estreptozocina/toxicidade , Animais , Linhagem Celular Tumoral , Sobrevivência Celular , Quimiocina CXCL10/genética , Quimiocina CXCL10/metabolismo , Diabetes Mellitus Experimental , Regulação da Expressão Gênica/efeitos dos fármacos , Inativação Gênica , Quinase I-kappa B/genética , Quinase I-kappa B/metabolismo , Células Secretoras de Insulina/metabolismo , Insulinoma/metabolismo , Masculino , Camundongos , Camundongos Knockout , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo II/metabolismo , Fator de Necrose Tumoral alfa/farmacologia
18.
Int J Biochem Cell Biol ; 127: 105840, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32866686

RESUMO

Ras Guanine Exchange Factor (RasGEF) domain family member 1b is encoded by a Toll-like receptor (TLR)-inducible gene expressed in macrophages, but transcriptional mechanisms that govern its expression are still unknown. Here, we have functionally characterized the 5' flanking Rasgef1b sequence and analyzed its transcriptional activation. We have identified that the inflammation-responsive promoter is contained within a short sequence (-183 to +119) surrounding the transcriptional start site. The promoter sequence is evolutionarily conserved and harbors a cluster of five NF-κB binding sites. Luciferase reporter gene assay showed that the promoter is responsive to TLR activation and RelA or cRel, but not RelB, transcription factors. Besides, site-directed mutagenesis showed that the κB binding sites are required for maximal promoter activation induced by LPS. Analysis by Assay for Transposase-Accessible Chromatin using sequencing (ATAC-seq) revealed that the promoter is located in an accessible chromatin region. More important, Chromatin Immunoprecipitation sequencing (ChIP-seq) showed that RelA is recruited to the promoter region upon LPS stimulation of bone marrow-derived macrophages. Finally, studies with Rela-deficient macrophages or pharmacological inhibition by Bay11-7082 showed that NF-κB is required for optimal Rasgef1b expression induced by TLR agonists. Our data provide evidence of the regulatory mechanism mediated by NF-κB that facilitates Rasgef1b expression after TLR activation in macrophages.


Assuntos
Macrófagos/metabolismo , NF-kappa B/metabolismo , Receptores Toll-Like/metabolismo , Fatores ras de Troca de Nucleotídeo Guanina/biossíntese , Animais , Células Cultivadas , Lipopolissacarídeos/farmacologia , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/genética , Regiões Promotoras Genéticas , Ativação Transcricional , Fatores ras de Troca de Nucleotídeo Guanina/genética , Fatores ras de Troca de Nucleotídeo Guanina/metabolismo
19.
Life Sci ; 258: 118189, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32781060

RESUMO

Origin of drug and radio-refractory clones, cancer stem-like cells, and rapid angiogenesis and metastasis are among the primary concerns that limit the efficacy of anticancer treatments, emphasizing the urgency of developing new therapeutics. Factors like high attrition rates, huge investments, patients' heterogeneity, and diverse molecular subtypes have challenged the rapid development of anticancer drugs. Treatment with repurposing pleiotropic benzimidazole antihelminthics, like mebendazole, albendazole, and flubendazole has recently opened a new window, owing to their easy access, low cost as a generic drug, and long track record of safe use in the human population. This review highlights the outcomes of preclinical and clinical studies of these drugs as a potent anticancer agent(s) conducted in the last two decades. Substantial preclinical studies, as well as limited clinical trials, suggest noteworthy anticancer potency of these pleiotropic benzimidazoles, particularly as potent microtubule disrupting, anti-angiogenic, and anti-metastatic agents, inhibitors of the immune checkpoint, hypoxia-inducible factor, epithelial-mesenchymal transition, cancer stemness, and multidrug resistance protein 1, and inducers of apoptosis and M1 polarization. These anticancer effects are attributed to multiple action points, including intrinsic apoptosis, canonical Wnt/ß-catenin, JAK/STAT-3, JNK, MEK/ERK, and hedgehog signaling pathways. The effective anticancer properties of mebendazole, albendazole, and flubendazole either alone or synergistically with frontline drugs, warrant their validation through controlled clinical trials to use them as promising avenues to anticancer therapy.


Assuntos
Anti-Helmínticos/uso terapêutico , Antineoplásicos/uso terapêutico , Benzimidazóis/uso terapêutico , Reposicionamento de Medicamentos , Neoplasias/tratamento farmacológico , Animais , Ensaios Clínicos como Assunto , Humanos
20.
Nat Commun ; 11(1): 3409, 2020 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-32641778

RESUMO

Pancreatic ductal adenocarcinoma (PDAC) is associated with high mortality and therapy resistance. Here, we show that low expression of κB-Ras GTPases is frequently detected in PDAC and correlates with higher histologic grade. In a model of KRasG12D-driven PDAC, loss of κB-Ras accelerates tumour development and shortens median survival. κB-Ras deficiency promotes acinar-to-ductal metaplasia (ADM) during tumour initiation as well as tumour progression through intrinsic effects on proliferation and invasion. κB-Ras proteins are also required for acinar regeneration after pancreatitis, demonstrating a general role in control of plasticity. Molecularly, upregulation of Ral GTPase activity and Sox9 expression underlies the observed phenotypes, identifying a previously unrecognized function of Ral signalling in ADM. Our results provide evidence for a tumour suppressive role of κB-Ras proteins and highlight low κB-Ras levels and consequent loss of Ral control as risk factors, thus emphasizing the necessity for therapeutic options that allow interference with Ral-driven signalling.


Assuntos
Células Acinares/metabolismo , Carcinoma Ductal Pancreático/genética , GTP Fosfo-Hidrolases/genética , Neoplasias Pancreáticas/genética , Pancreatite/genética , Proteínas/genética , Células Acinares/patologia , Idoso , Animais , Carcinoma Ductal Pancreático/metabolismo , Carcinoma Ductal Pancreático/patologia , Linhagem Celular Tumoral , Feminino , GTP Fosfo-Hidrolases/metabolismo , Regulação da Expressão Gênica , Humanos , Proteínas I-kappa B/genética , Proteínas I-kappa B/metabolismo , Estimativa de Kaplan-Meier , Masculino , Metaplasia/genética , Metaplasia/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Pancreatite/metabolismo , Proteínas/metabolismo , Fatores de Transcrição SOX9/genética , Fatores de Transcrição SOX9/metabolismo , Proteínas ral de Ligação ao GTP/genética , Proteínas ral de Ligação ao GTP/metabolismo , Proteínas ras/genética , Proteínas ras/metabolismo
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