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1.
Cell ; 184(16): 4186-4202.e20, 2021 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-34216540

RESUMO

Polyamine synthesis represents one of the most profound metabolic changes during T cell activation, but the biological implications of this are scarcely known. Here, we show that polyamine metabolism is a fundamental process governing the ability of CD4+ helper T cells (TH) to polarize into different functional fates. Deficiency in ornithine decarboxylase, a crucial enzyme for polyamine synthesis, results in a severe failure of CD4+ T cells to adopt correct subset specification, underscored by ectopic expression of multiple cytokines and lineage-defining transcription factors across TH cell subsets. Polyamines control TH differentiation by providing substrates for deoxyhypusine synthase, which synthesizes the amino acid hypusine, and mice in which T cells are deficient for hypusine develop severe intestinal inflammatory disease. Polyamine-hypusine deficiency caused widespread epigenetic remodeling driven by alterations in histone acetylation and a re-wired tricarboxylic acid (TCA) cycle. Thus, polyamine metabolism is critical for maintaining the epigenome to focus TH cell subset fidelity.


Assuntos
Linhagem da Célula , Poliaminas/metabolismo , Linfócitos T Auxiliares-Indutores/citologia , Linfócitos T Auxiliares-Indutores/metabolismo , Animais , Diferenciação Celular/efeitos dos fármacos , Linhagem da Célula/efeitos dos fármacos , Polaridade Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Cromatina/metabolismo , Ciclo do Ácido Cítrico/efeitos dos fármacos , Colite/imunologia , Colite/patologia , Citocinas/metabolismo , Modelos Animais de Doenças , Inibidores Enzimáticos/farmacologia , Epigenoma , Histonas/metabolismo , Inflamação/imunologia , Inflamação/patologia , Subpopulações de Linfócitos/efeitos dos fármacos , Subpopulações de Linfócitos/metabolismo , Lisina/análogos & derivados , Lisina/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Ornitina Descarboxilase/metabolismo , Linfócitos T Auxiliares-Indutores/efeitos dos fármacos , Células Th17/efeitos dos fármacos , Células Th17/imunologia , Fatores de Transcrição/metabolismo
2.
Immunity ; 56(9): 2036-2053.e12, 2023 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-37572656

RESUMO

Arginase 1 (Arg1), the enzyme catalyzing the conversion of arginine to ornithine, is a hallmark of IL-10-producing immunoregulatory M2 macrophages. However, its expression in T cells is disputed. Here, we demonstrate that induction of Arg1 expression is a key feature of lung CD4+ T cells during mouse in vivo influenza infection. Conditional ablation of Arg1 in CD4+ T cells accelerated both virus-specific T helper 1 (Th1) effector responses and its resolution, resulting in efficient viral clearance and reduced lung pathology. Using unbiased transcriptomics and metabolomics, we found that Arg1-deficiency was distinct from Arg2-deficiency and caused altered glutamine metabolism. Rebalancing this perturbed glutamine flux normalized the cellular Th1 response. CD4+ T cells from rare ARG1-deficient patients or CRISPR-Cas9-mediated ARG1-deletion in healthy donor cells phenocopied the murine cellular phenotype. Collectively, CD4+ T cell-intrinsic Arg1 functions as an unexpected rheostat regulating the kinetics of the mammalian Th1 lifecycle with implications for Th1-associated tissue pathologies.


Assuntos
Arginase , Influenza Humana , Animais , Humanos , Camundongos , Arginase/genética , Arginase/metabolismo , Linfócitos T CD4-Positivos/metabolismo , Glutamina , Cinética , Pulmão/metabolismo , Mamíferos
3.
BMC Cancer ; 22(1): 1254, 2022 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-36460969

RESUMO

The integrated stress response (ISR) facilitates cellular adaptation to unfavorable conditions by reprogramming the cellular response. ISR activation was reported in neurological disorders and solid tumors; however, the function of ISR and its role as a possible therapeutic target in hematological malignancies still remain largely unexplored. Previously, we showed that the ISR is activated in chronic myeloid leukemia (CML) cells and correlates with blastic transformation and tyrosine kinase inhibitor (TKI) resistance. Moreover, the ISR was additionally activated in response to imatinib as a type of protective internal signaling. Here, we show that ISR inhibition combined with imatinib treatment sensitized and more effectively eradicated leukemic cells both in vitro and in vivo compared to treatment with single agents. The combined treatment specifically inhibited the STAT5 and RAS/RAF/MEK/ERK pathways, which are recognized as drivers of resistance. Mechanistically, this drug combination attenuated both interacting signaling networks, leading to BCR-ABL1- and ISR-dependent STAT5 activation. Consequently, leukemia engraftment in patient-derived xenograft mice bearing CD34+ TKI-resistant CML blasts carrying PTPN11 mutation responsible for hyperactivation of the RAS/RAF/MAPK and JAK/STAT5 pathways was decreased upon double treatment. This correlated with the downregulation of genes related to the RAS/RAF/MAPK, JAK/STAT5 and stress response pathways and was associated with lower expression of STAT5-target genes regulating proliferation, viability and the stress response. Collectively, these findings highlight the effect of imatinib plus ISRIB in the eradication of leukemic cells resistant to TKIs and suggest potential clinical benefits for leukemia patients with TKI resistance related to RAS/RAF/MAPK or STAT5 signaling. We propose that personalized treatment based on the genetic selection of patients carrying mutations that cause overactivation of the targeted pathways and therefore make their sensitivity to such treatment probable should be considered as a possible future direction in leukemia treatment.


Assuntos
Leucemia Mielogênica Crônica BCR-ABL Positiva , Leucemia Mieloide , Humanos , Animais , Camundongos , Fator de Transcrição STAT5/genética , Mesilato de Imatinib/farmacologia , Mesilato de Imatinib/uso terapêutico , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Transdução de Sinais , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico
4.
Haemophilia ; 28(2): 270-277, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35182444

RESUMO

INTRODUCTION: Inhibitor development affects about 30% of patients with severe haemophilia A (HA) and results from different environmental and genetic risk factors. Previously, we identified the missense variant rs3754689 in the LCT gene linked with this predisposition. Since rs3754689 variant is benign and is located in a conserved haplotype region, we hypothesized that the association signal captured by this variant is located in coinherited, neighbouring genes. AIM: To identify novel genetic risk factors associated with inhibitor development in coding regions of R3HDM1, UBXN4, CXCR4, MCM6, DARS and miR128-1 genes. METHODS: Targeted sequencing was performed in 246 severe HA patients (72 with and 174 without inhibitor): 181 previously and 65 newly enrolled. RESULTS: Forty-one common and 152 rare variants passed the quality control. Logistic regression analysis of common variants identified rs3754689 and four additional variants (.011 < P < .047; FDR ranging .2-.38). Logistic regression analysis performed only in the 220 Italian patients showed similar results (.004 < P < .05; FDR ranging .12-.22). Three of these variants (rs3213892 and rs3816155 in the LCT intron 13 and rs961360 in the R3HDM1 intron10-exon11 junction) may affect the expression of UBXN4 and R3HDM1, respectively. Rare variants did not show association with inhibitor development. Identified variants were not replicated in the multi-ethnic SIPPET cohort of 230 severe HA patients. CONCLUSION: Due to the limited sample size that may be responsible of the high FDR values, we could not confirm with certainty the analysed association. Further evaluation of the expression levels of analysed genes will confirm or not their role in inhibitor development.


Assuntos
Hemofilia A , Estudos de Coortes , Predisposição Genética para Doença , Genótipo , Hemofilia A/genética , Humanos , Mutação de Sentido Incorreto , Polimorfismo de Nucleotídeo Único
5.
Nature ; 532(7599): 389-93, 2016 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-27064903

RESUMO

Asymmetric cell division, the partitioning of cellular components in response to polarizing cues during mitosis, has roles in differentiation and development. It is important for the self-renewal of fertilized zygotes in Caenorhabditis elegans and neuroblasts in Drosophila, and in the development of mammalian nervous and digestive systems. T lymphocytes, upon activation by antigen-presenting cells (APCs), can undergo asymmetric cell division, wherein the daughter cell proximal to the APC is more likely to differentiate into an effector-like T cell and the distal daughter is more likely to differentiate into a memory-like T cell. Upon activation and before cell division, expression of the transcription factor c-Myc drives metabolic reprogramming, necessary for the subsequent proliferative burst. Here we find that during the first division of an activated T cell in mice, c-Myc can sort asymmetrically. Asymmetric distribution of amino acid transporters, amino acid content, and activity of mammalian target of rapamycin complex 1 (mTORC1) is correlated with c-Myc expression, and both amino acids and mTORC1 activity sustain the differences in c-Myc expression in one daughter cell compared to the other. Asymmetric c-Myc levels in daughter T cells affect proliferation, metabolism, and differentiation, and these effects are altered by experimental manipulation of mTORC1 activity or c-Myc expression. Therefore, metabolic signalling pathways cooperate with transcription programs to maintain differential cell fates following asymmetric T-cell division.


Assuntos
Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/metabolismo , Divisão Celular , Polaridade Celular , Ativação Linfocitária , Sistemas de Transporte de Aminoácidos/metabolismo , Aminoácidos/metabolismo , Animais , Diferenciação Celular/genética , Polaridade Celular/genética , Feminino , Masculino , Alvo Mecanístico do Complexo 1 de Rapamicina , Camundongos , Complexos Multiproteicos/metabolismo , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , Transdução de Sinais/genética , Serina-Treonina Quinases TOR/metabolismo , Transcrição Gênica
6.
Proc Natl Acad Sci U S A ; 116(22): 10705-10710, 2019 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-31061125

RESUMO

The third millennium BCE was a period of major cultural and demographic changes in Europe that signaled the beginning of the Bronze Age. People from the Pontic steppe expanded westward, leading to the formation of the Corded Ware complex and transforming the genetic landscape of Europe. At the time, the Globular Amphora culture (3300-2700 BCE) existed over large parts of Central and Eastern Europe, but little is known about their interaction with neighboring Corded Ware groups and steppe societies. Here we present a detailed study of a Late Neolithic mass grave from southern Poland belonging to the Globular Amphora culture and containing the remains of 15 men, women, and children, all killed by blows to the head. We sequenced their genomes to between 1.1- and 3.9-fold coverage and performed kinship analyses that demonstrate that the individuals belonged to a large extended family. The bodies had been carefully laid out according to kin relationships by someone who evidently knew the deceased. From a population genetic viewpoint, the people from Koszyce are clearly distinct from neighboring Corded Ware groups because of their lack of steppe-related ancestry. Although the reason for the massacre is unknown, it is possible that it was connected with the expansion of Corded Ware groups, which may have resulted in competition for resources and violent conflict. Together with the archaeological evidence, these analyses provide an unprecedented level of insight into the kinship structure and social behavior of a Late Neolithic community.


Assuntos
Sepultamento/história , DNA Antigo/análise , Violência/história , Adolescente , Adulto , Arqueologia , Criança , Pré-Escolar , Feminino , História Antiga , Migração Humana , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Linhagem , Polônia , Adulto Jovem
7.
Int J Mol Sci ; 23(4)2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-35216274

RESUMO

Inflammatory bowel diseases (IBD) are chronic and relapsing gastrointestinal disorders, where a significant proportion of patients are unresponsive or lose response to traditional and currently used therapies. In the current study, we propose a new concept for anti-inflammatory treatment based on a selective acidic mammalian chitinase (AMCase) inhibitor. The functions of chitinases remain unclear, but they have been shown to be implicated in the pathology of various inflammatory disorders regarding the lung (asthma, idiopathic pulmonary fibrosis) and gastrointestinal tract (IBD and colon cancer). The aim of the study is to investigate the impact of AMCase inhibitor (OAT-177) on the dextran sulfate sodium (DSS)-induced models of colitis. In the short-term therapeutic protocol, OAT-177 given intragastrically in a 30 mg/kg dose, twice daily, produced a significant (p < 0.001) anti-inflammatory effect, as shown by the macroscopic score. Additionally, OAT-177 significantly decreased TNF-α mRNA levels and MPO activity compared to DSS-only treated mice. Intraperitoneal administration of OAT-177 at a dose of 50 mg/kg caused statistically relevant reduction of the colon length. In the long-term therapeutic protocol, OAT-177 given intragastrically in a dose of 30 mg/kg, twice daily, significantly improved colon length and body weight compared to DSS-induced colitis. This is the first study proving that AMCase inhibitors may have therapeutic potential in the treatment of IBD.


Assuntos
Anti-Inflamatórios/farmacologia , Quitinases/antagonistas & inibidores , Colite/tratamento farmacológico , Animais , Colite/induzido quimicamente , Colite/metabolismo , Colo/efeitos dos fármacos , Colo/metabolismo , Citocinas/metabolismo , Sulfato de Dextrana/farmacologia , Modelos Animais de Doenças , Feminino , Doenças Inflamatórias Intestinais/induzido quimicamente , Doenças Inflamatórias Intestinais/tratamento farmacológico , Doenças Inflamatórias Intestinais/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL
8.
Eur J Haematol ; 106(3): 320-326, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33190294

RESUMO

BACKGROUND: Ibrutinib, an inhibitor of the Bruton's kinase (BTK), is characterized by high efficacy in the therapy of patients with relapsed and refractory chronic lymphocytic leukemia (RR-CLL). AIMS: To analyze the potential significance of the mutational status of selected 30 genes on the disease outcome in 45 patients with RR-CLL using custom-made gene panel and sequencing on Illumina MiSeq FGx platform. RESULTS: The highest rate of mutations was observed in TP53 (n = 18; 40.0%), NOTCH1 (n = 13; 28.8%), SF3B1 (n = 11; 24.4%), ATM (n = 7; 15.6%), MED12 (n = 6, 13.3%), CHD2 (n = 5; 11.1%), XPO1 (n = 5; 11.1%), NFKBIE (n = 5; 11.1%), BIRC3 (n = 4; 8.9%), SPEN (n = 4; 8.9%), POT1 (n = 4; 8.9%), EGR2 (n = 3; 6.7%), and RPS15 (n = 3; 6.7%). With a median observation time of 45.9 months, the median progression-free survival (PFS) and overall survival (OS) were not reached. The 36-month estimated rate of PFS and OS were 64% and 68.2%, respectively. The overall response rate was noted in 23 patients (51.1%), while twenty (44.4%) patients achieved stability. Progression was noted in 2 (4.5%) cases. Analyzed molecular factors had no impact on PFS and OS. CONCLUSION: Despite accumulation of several poor prognostic factors in our real-life cohort of heavily pretreated patients with CLL, ibrutinib treatment showed long-term clinical benefit.


Assuntos
Adenina/análogos & derivados , Biomarcadores Tumorais/genética , Leucemia Linfocítica Crônica de Células B/genética , Mutação , Piperidinas/uso terapêutico , Inibidores de Proteínas Quinases/uso terapêutico , Adenina/administração & dosagem , Adenina/efeitos adversos , Adenina/uso terapêutico , Resistencia a Medicamentos Antineoplásicos , Testes Genéticos , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Leucemia Linfocítica Crônica de Células B/diagnóstico , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Leucemia Linfocítica Crônica de Células B/mortalidade , Terapia de Alvo Molecular , Piperidinas/administração & dosagem , Piperidinas/efeitos adversos , Prognóstico , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/efeitos adversos , Recidiva , Resultado do Tratamento
9.
Neurol Sci ; 42(7): 2819-2827, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33170376

RESUMO

BACKGROUND: Myofibrillar myopathies (MFM) are a subgroup of protein aggregate myopathies (PAM) characterized by a common histological picture of myofibrillar dissolution, Z-disk disintegration, and accumulation of degradation products into inclusions. Mutations in genes encoding components of the Z-disk or Z-disk-associated proteins occur in some patients whereas in most of the cases, the causative gene defect is still unknown. We aimed to search for pathogenic mutations in genes not previously associated with MFM phenotype. METHODS: We performed whole-exome sequencing in four patients from three unrelated families who were diagnosed with PAM without aberrations in causative genes for MFM. RESULTS: In the first patient and her affected daughter, we identified a heterozygous p.(Arg89Cys) missense mutation in LMNA gene which has not been linked with PAM pathology before. In the second patient, a heterozygous p.(Asn4807Phe) mutation in RYR1 not previously described in PAM represents a novel, candidate gene with a possible causative role in the disease. Finally, in the third patient and his symptomatic daughter, we found a previously reported heterozygous p.(Cys30071Arg) mutation in TTN gene that was clinically associated with cardiac involvement. CONCLUSIONS: Our study identifies a new genetic background in PAM pathology and expands the clinical phenotype of known pathogenic mutations.


Assuntos
Miopatias Congênitas Estruturais , Agregados Proteicos , Feminino , Humanos , Mutação/genética , Miopatias Congênitas Estruturais/genética , Fenótipo , Sequenciamento do Exoma
10.
Int J Mol Sci ; 22(13)2021 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-34203467

RESUMO

Chitinases belong to the evolutionarily conserved glycosyl hydrolase family 18 (GH18). They catalyze degradation of chitin to N-acetylglucosamine by hydrolysis of the ß-(1-4)-glycosidic bonds. Although mammals do not synthesize chitin, they possess two enzymatically active chitinases, i.e., chitotriosidase (CHIT1) and acidic mammalian chitinase (AMCase), as well as several chitinase-like proteins (YKL-40, YKL-39, oviductin, and stabilin-interacting protein). The latter lack enzymatic activity but still display oligosaccharides-binding ability. The physiologic functions of chitinases are still unclear, but they have been shown to be involved in the pathogenesis of various human fibrotic and inflammatory disorders, particularly those of the lung (idiopathic pulmonary fibrosis, chronic obstructive pulmonary disease, sarcoidosis, and asthma) and the gastrointestinal tract (inflammatory bowel diseases (IBDs) and colon cancer). In this review, we summarize the current knowledge about chitinases, particularly in IBDs, and demonstrate that chitinases can serve as prognostic biomarkers of disease progression. Moreover, we suggest that the inhibition of chitinase activity may be considered as a novel therapeutic strategy for the treatment of IBDs.


Assuntos
Quitinases/metabolismo , Inflamação/metabolismo , Doenças Inflamatórias Intestinais/metabolismo , Animais , Proteína 1 Semelhante à Quitinase-3/genética , Proteína 1 Semelhante à Quitinase-3/metabolismo , Quitinases/genética , Humanos , Inflamação/genética , Doenças Inflamatórias Intestinais/genética
11.
Cent Eur J Immunol ; 46(1): 121-126, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33897294

RESUMO

Myeloproliferative neoplasms (MPNs) are a group of hematologic disorders characterized by clonal proliferation of myeloid lineage cells. The diagnostic criteria are based on morphological features of bone marrow and peripheral blood cells but also include specific genomic mutations. In some patients, co-occurrence of hematologic and rheumatic diseases could be observed. To date, most of the reported cases concerned patients with myelodysplastic syndrome (MDS) or essential thrombocythemia (ET). In this paper, we present a case of a patient with a complicated diagnostic process leading to the diagnosis of unclassified MPN and giant cell arteritis (GCA). Routine tests did not reveal any mutations typical for MPNs such as JAK-2, CALR, MPL or BCR-ABL. Targeted next-generation sequencing (NGS) helped to confirm the diagnosis by demonstrating the presence of heterozygous ASXL1, TET2, SRSF2, and CBL mutations. The second important issue was the overlapping of symptoms of MPN and seronegative rheumatic disease, which finally was diagnosed as GCA. Leukocytosis and musculoskeletal pain, which were present at the time of diagnosis, resolved after allogeneic hematopoietic stem cell transplantation but recurred after a few months along with decreasing donor cell chimerism. Differentiation of the causes of recurrence of the symptoms was an important issue. This case shows the diagnostic challenge posed by co-incidence of MPN and rheumatic disease, especially its atypical variants.

12.
Blood ; 132(1): 67-77, 2018 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-29784639

RESUMO

Mutations in FMS-like tyrosine kinase 3 (FLT3), such as internal tandem duplications (ITDs), can be found in up to 23% of patients with acute myeloid leukemia (AML) and confer a poor prognosis. Current treatment options for FLT3(ITD)-positive AMLs include genotoxic therapy and FLT3 inhibitors (FLT3i's), which are rarely curative. PARP1 inhibitors (PARP1i's) have been successfully applied to induce synthetic lethality in tumors harboring BRCA1/2 mutations and displaying homologous recombination (HR) deficiency. We show here that inhibition of FLT3(ITD) activity by the FLT3i AC220 caused downregulation of DNA repair proteins BRCA1, BRCA2, PALB2, RAD51, and LIG4, resulting in inhibition of 2 major DNA double-strand break (DSB) repair pathways, HR, and nonhomologous end-joining. PARP1i, olaparib, and BMN673 caused accumulation of lethal DSBs and cell death in AC220-treated FLT3(ITD)-positive leukemia cells, thus mimicking synthetic lethality. Moreover, the combination of FLT3i and PARP1i eliminated FLT3(ITD)-positive quiescent and proliferating leukemia stem cells, as well as leukemic progenitors, from human and mouse leukemia samples. Notably, the combination of AC220 and BMN673 significantly delayed disease onset and effectively reduced leukemia-initiating cells in an FLT3(ITD)-positive primary AML xenograft mouse model. In conclusion, we postulate that FLT3i-induced deficiencies in DSB repair pathways sensitize FLT3(ITD)-positive AML cells to synthetic lethality triggered by PARP1i's. Therefore, FLT3(ITD) could be used as a precision medicine marker for identifying AML patients that may benefit from a therapeutic regimen combining FLT3 and PARP1i's.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Reparo do DNA/efeitos dos fármacos , Leucemia Mieloide Aguda , Poli(ADP-Ribose) Polimerase-1/antagonistas & inibidores , Tirosina Quinase 3 Semelhante a fms/metabolismo , Animais , Proteína BRCA1/genética , Proteína BRCA1/metabolismo , Proteína BRCA2/genética , Proteína BRCA2/metabolismo , Benzotiazóis/farmacologia , Linhagem Celular Tumoral , DNA Ligase Dependente de ATP/genética , DNA Ligase Dependente de ATP/metabolismo , Proteína do Grupo de Complementação N da Anemia de Fanconi/genética , Proteína do Grupo de Complementação N da Anemia de Fanconi/metabolismo , Humanos , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/patologia , Camundongos , Mutação , Compostos de Fenilureia/farmacologia , Ftalazinas/farmacologia , Piperazinas/farmacologia , Poli(ADP-Ribose) Polimerase-1/genética , Poli(ADP-Ribose) Polimerase-1/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Rad51 Recombinase/genética , Rad51 Recombinase/metabolismo , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto , Tirosina Quinase 3 Semelhante a fms/genética
13.
Nature ; 511(7510): 488-492, 2014 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-25043028

RESUMO

The c-myc proto-oncogene product, Myc, is a transcription factor that binds thousands of genomic loci. Recent work suggested that rather than up- and downregulating selected groups of genes, Myc targets all active promoters and enhancers in the genome (a phenomenon termed 'invasion') and acts as a general amplifier of transcription. However, the available data did not readily discriminate between direct and indirect effects of Myc on RNA biogenesis. We addressed this issue with genome-wide chromatin immunoprecipitation and RNA expression profiles during B-cell lymphomagenesis in mice, in cultured B cells and fibroblasts. Consistent with long-standing observations, we detected general increases in total RNA or messenger RNA copies per cell (hereby termed 'amplification') when comparing actively proliferating cells with control quiescent cells: this was true whether cells were stimulated by mitogens (requiring endogenous Myc for a proliferative response) or by deregulated, oncogenic Myc activity. RNA amplification and promoter/enhancer invasion by Myc were separable phenomena that could occur without one another. Moreover, whether or not associated with RNA amplification, Myc drove the differential expression of distinct subsets of target genes. Hence, although having the potential to interact with all active or poised regulatory elements in the genome, Myc does not directly act as a global transcriptional amplifier. Instead, our results indicate that Myc activates and represses transcription of discrete gene sets, leading to changes in cellular state that can in turn feed back on global RNA production and turnover.


Assuntos
Proliferação de Células , Transformação Celular Neoplásica/genética , Regulação Neoplásica da Expressão Gênica , Linfoma de Células B/genética , Linfoma de Células B/patologia , Proteínas Proto-Oncogênicas c-myc/metabolismo , Transcrição Gênica , Animais , Linfócitos B/metabolismo , Linfócitos B/patologia , Transformação Celular Neoplásica/patologia , Cromatina/genética , Cromatina/metabolismo , Imunoprecipitação da Cromatina , Progressão da Doença , Regulação para Baixo/genética , Feminino , Fibroblastos/citologia , Fibroblastos/metabolismo , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica/genética , Genoma/genética , Linfoma de Células B/metabolismo , Masculino , Camundongos , Mitógenos/farmacologia , Regiões Promotoras Genéticas/genética , Proteínas Proto-Oncogênicas c-myc/genética , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Fatores de Transcrição/metabolismo , Transcrição Gênica/genética , Regulação para Cima/genética
14.
Semin Immunol ; 28(5): 525-534, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27771141

RESUMO

T cell activation results in a rapidly proliferating T cell endowed with a metabolic phenotype necessary for growth and division. However, before the cell can proceed towards this burst of cell division a phase of quiescence occurs, during which the basic mechanisms governing regulation of metabolic reprograming are established. This review focuses on key cellular processes controlling early metabolic regulation and how these circuits of metabolic control dictate distinct cellular fates upon the first asymmetric division.


Assuntos
Divisão Celular Assimétrica , Metabolismo Energético , Ativação Linfocitária/imunologia , Linfócitos T/imunologia , Linfócitos T/metabolismo , Animais , Divisão Celular Assimétrica/genética , Divisão Celular Assimétrica/imunologia , Biomarcadores , Regulação da Expressão Gênica , Humanos , Ativação Linfocitária/genética , Transdução de Sinais
15.
J Biol Chem ; 293(28): 11088-11099, 2018 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-29784881

RESUMO

In higher eukaryotes, several ATP-utilizing enzymes known as hexokinases activate glucose in the glycolysis pathway by phosphorylation to glucose 6-phosphate. In contrast to canonical hexokinases, which use ATP, ADP-dependent glucokinase (ADPGK) catalyzes noncanonical phosphorylation of glucose to glucose 6-phosphate using ADP as a phosphate donor. Initially discovered in Archaea, the human homolog of ADPGK was described only recently. ADPGK's involvement in modified bioenergetics of activated T cells has been postulated, and elevated ADPGK expression has been reported in various cancer tissues. However, the physiological role of ADPGK is still poorly understood, and effective ADPGK inhibitors still await discovery. Here, we show that 8-bromo-substituted adenosine nucleotide inhibits human ADPGK. By solving the crystal structure of archaeal ADPGK in complex with 8-bromoadenosine phosphate (8-Br-AMP) at 1.81 Å resolution, we identified the mechanism of inhibition. We observed that 8-Br-AMP is a competitive inhibitor of ADPGK and that the bromine substitution induces marked structural changes within the protein's active site by engaging crucial catalytic residues. The results obtained using the Jurkat model of activated human T cells suggest its moderate activity in a cellular setting. We propose that our structural insights provide a critical basis for rational development of novel ADPGK inhibitors.


Assuntos
Adenosina/análogos & derivados , Glucoquinase/química , Adenosina/química , Adenosina/farmacologia , Domínio Catalítico , Cristalografia por Raios X , Glucoquinase/antagonistas & inibidores , Glucose/metabolismo , Humanos , Células Jurkat , Conformação Proteica
16.
Genome Res ; 26(4): 554-65, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26821571

RESUMO

The regulation of miRNAs is critical to the definition of cell identity and behavior in normal physiology and disease. To date, the dynamics of miRNA degradation and the mechanisms involved in remain largely obscure, in particular, in higher organisms. Here, we developed a pulse-chase approach based on metabolic RNA labeling to calculate miRNA decay rates at genome-wide scale in mammalian cells. Our analysis revealed heterogeneous miRNA half-lives, with many species behaving as stable molecules (T1/2> 24 h), while others, including passenger miRNAs and a number (25/129) of guide miRNAs, are quickly turned over (T1/2= 4-14 h). Decay rates were coupled with other features, including genomic organization, transcription rates, structural heterogeneity (isomiRs), and target abundance, measured through quantitative experimental approaches. This comprehensive analysis highlighted functional mechanisms that mediate miRNA degradation, as well as the importance of decay dynamics in the regulation of the miRNA pool under both steady-state conditions and during cell transitions.


Assuntos
MicroRNAs/genética , Animais , Proteínas Argonautas/metabolismo , Fibroblastos , Regulação da Expressão Gênica , Estudo de Associação Genômica Ampla , Camundongos , MicroRNAs/metabolismo , Interferência de RNA , Estabilidade de RNA , Ribonuclease III/metabolismo , Fatores de Tempo , Transcrição Gênica
17.
Haematologica ; 104(10): 2084-2090, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-30819905

RESUMO

Primary platelet secretion defects constitute a heterogeneous group of functional defects characterized by reduced platelet granule secretion upon stimulation by different agonists. The clinical and laboratory heterogeneity of primary platelet secretion defects warrants a tailored approach. We performed a pilot study in order to develop DNA sequence analysis pipelines for gene discovery and to create a list of candidate causal genes for platelet secretion defects. Whole-exome sequencing analysis of 14 unrelated Italian patients with primary secretion defects and 16 controls was performed on Illumina HiSeq. Variant prioritization was carried out using two filtering approaches: identification of rare, potentially damaging variants in platelet candidate genes or by selecting singletons. To corroborate the results, exome sequencing was applied in a family in which platelet secretion defects and a bleeding diathesis were present. Platelet candidate gene analysis revealed gene defects in 10/14 patients, which included ADRA2A, ARHGAP1, DIAPH1, EXOC1, FCGR2A, ITPR1, LTBP1, PTPN7, PTPN12, PRKACG, PRKCD, RAP1GAP, STXBP5L, and VWF The analysis of singletons identified additional gene defects in PLG and PHACTR2 in two other patients. The family analysis confirmed a missense variant p.D1144N in the STXBP5L gene and p.P83H in the KCNMB3 gene as potentially causal. In summary, exome sequencing revealed potential causal variants in 12 of 14 patients with primary platelet secretion defects, highlighting the limitations of the genomic approaches for causal gene identification in this heterogeneous clinical and laboratory phenotype.


Assuntos
Transtornos Plaquetários/genética , Sequenciamento do Exoma , Adulto , Transtornos Plaquetários/metabolismo , Transtornos Plaquetários/patologia , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto
18.
Blood ; 127(23): 2924-33, 2016 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-27060170

RESUMO

The development of neutralizing antibodies (inhibitors) against coagulation factor VIII (FVIII) is the most problematic and costly complication of FVIII replacement therapy that affects up to 30% of previously untreated patients with severe hemophilia A. The development of inhibitors is a multifactorial complication involving environmental and genetic factors. Among the latter, F8 gene mutations, ethnicity, family history of inhibitors, and polymorphisms affecting genes involved in the immune response have been previously investigated. To identify novel genetic elements underling the risk of inhibitor development in patients with severe hemophilia A, we applied whole-exome sequencing (WES) and data analysis in a selected group of 26 Italian patients with (n = 17) and without (n = 9) inhibitors. WES revealed several rare, damaging variants in immunoregulatory genes as novel candidate mutations. A case-control association analysis using Cochran-Armitage and Fisher's exact statistical tests identified 1364 statistically significant variants. Hierarchical clustering of these genetic variants showed 2 distinct patterns of homozygous variants with a protective or harmful role in inhibitor development. When looking solely at coding variants, a total of 28 nonsynonymous variants were identified and replicated in 53 inhibitor-positive and 174 inhibitor-negative Italian severe hemophilia A patients using a TaqMan genotyping assay. The genotyping results revealed 10 variants showing estimated odds ratios in the same direction as in the discovery phase and confirmed the association of the rs3754689 missense variant (OR 0.58; 95% CI 0.36-0.94; P = .028) in a highly conserved haplotype region surrounding the LCT locus on chromosome 2q21 with inhibitor development.


Assuntos
Anticorpos Neutralizantes/biossíntese , Inibidores dos Fatores de Coagulação Sanguínea/biossíntese , Predisposição Genética para Doença , Hemofilia A/genética , Mutação , Estudos de Casos e Controles , Análise Mutacional de DNA/métodos , Estudo de Associação Genômica Ampla , Hemofilia A/imunologia , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Polimorfismo de Nucleotídeo Único , Fatores de Risco , Índice de Gravidade de Doença
19.
J Sep Sci ; 41(23): 4304-4314, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30303602

RESUMO

The review presents general principles for choosing optimal conditions for ecdysteroid separation, identification, and isolation using HPLC/TLC techniques in RP, NP-HILIC or NP modes. Analytics of ecdyteroids pose a still insufficiently resolved problem. Plant-derived ecdysteroids are a point of interest of pharmaceutical industry and sport medicine due to their postulated adaptogenic and anabolic properties. In insects, ecdysteroids regulate larval transformation. Maral root (Rhaponticum carthamoides, Leuzea carthamoides), traditional Siberian folk-medicine plant used as stimulant to boost overall health and fitness, is a particularly rich source of a wide variety of phytoecdysteroids. The similarity of molecular structures of ecdysteroids present in its extracts together with high content of unrelated compounds of similar chromatographic characteristics makes optimization of separation, identification and isolation of ecdysteroids a difficult analytical task. In that respect, two-dimensional separations, two-dimensional separations, 2D HPLC or 2D TLC, could be of use. For identification, the hyphenated techniques are particularly important. Thus, comprehensive overview of MS spectral parameters of ecdysteroids is provided. Described principles could easily be applied for separation of ecdysteroids in extracts from other sources. They are also useful for development of separation procedures for isolation of ecysteroids in preparative-scale applications.


Assuntos
Ecdisteroides/análise , Leuzea/química , Extratos Vegetais/análise , Raízes de Plantas/química , Cromatografia Líquida de Alta Pressão , Cromatografia em Camada Fina , Tamanho da Partícula , Propriedades de Superfície
20.
Neurol Neurochir Pol ; 50(2): 98-100, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26969565

RESUMO

The problem of executive functions in patients with normal pressure hydrocephalus (NPH) was investigated in the study. Executive function parameters were assumed to be among factors that may differentiate the clinical pattern in NPH. Two major indicators of executive functioning, i.e. flexibility and productivity of thinking, were assessed in neuropsychological examination using the Trail Making Test (TMT), Verbal Fluency Test (COWAT), and the Wisconsin Card Sorting Test (WCST). Participants in the study were 18 patients with NPH divided using a set of diagnostic criteria into two subgroups: with idiopathic active hydrocephalus (ACT) or with arrested hydrocephalus (ARR). Executive functioning patterns were found to differentiate between the two NPH subgroups. Namely, patients diagnosed with active hydrocephalus (who qualify for shunt implantation surgery) tended to present lower levels of verbal fluency in all semantic categories, which suggests a decreased productivity of thinking. Besides, ACT patients' performance on the WCST was significantly inferior on two measures: (1) they committed more non-perseverative errors (which indicates their chaotic way of working on the test and the occurrence of random responses) and (2) displayed lower ability of "learning to learn" (which suggests their impaired flexibility of thinking). These aspects of executive function, with productivity and flexibility of thinking first and foremost, seem promising as additional prognostic indicators to consider in patient selection for shunt implantation.


Assuntos
Derivações do Líquido Cefalorraquidiano , Função Executiva/fisiologia , Hidrocefalia de Pressão Normal/fisiopatologia , Adulto , Humanos , Hidrocefalia de Pressão Normal/cirurgia , Prognóstico
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