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1.
Brief Bioinform ; 23(6)2022 11 19.
Artigo em Inglês | MEDLINE | ID: mdl-36305426

RESUMO

The ongoing coronavirus disease 2019 (COVID-19) pandemic has highlighted the need to better understand virus-host interactions. We developed a network-based method that expands the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2)-host protein interaction network and identifies host targets that modulate viral infection. To disrupt the SARS-CoV-2 interactome, we systematically probed for potent compounds that selectively target the identified host proteins with high expression in cells relevant to COVID-19. We experimentally tested seven chemical inhibitors of the identified host proteins for modulation of SARS-CoV-2 infection in human cells that express ACE2 and TMPRSS2. Inhibition of the epigenetic regulators bromodomain-containing protein 4 (BRD4) and histone deacetylase 2 (HDAC2), along with ubiquitin-specific peptidase (USP10), enhanced SARS-CoV-2 infection. Such proviral effect was observed upon treatment with compounds JQ1, vorinostat, romidepsin and spautin-1, when measured by cytopathic effect and validated by viral RNA assays, suggesting that the host proteins HDAC2, BRD4 and USP10 have antiviral functions. We observed marked differences in antiviral effects across cell lines, which may have consequences for identification of selective modulators of viral infection or potential antiviral therapeutics. While network-based approaches enable systematic identification of host targets and selective compounds that may modulate the SARS-CoV-2 interactome, further developments are warranted to increase their accuracy and cell-context specificity.


Assuntos
Tratamento Farmacológico da COVID-19 , SARS-CoV-2 , Humanos , Mapas de Interação de Proteínas , Proteínas Nucleares , Fatores de Transcrição , Antivirais/farmacologia , Ubiquitina Tiolesterase , Proteínas de Ciclo Celular
2.
Hepatology ; 77(6): 2052-2062, 2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-36811400

RESUMO

BACKGROUND AND AIMS: Patients with compensated cirrhosis with clinically significant portal hypertension (CSPH: HVPG > 10 mm Hg) have a high risk of decompensation. HVPG is, however, an invasive procedure not available in all centers. The present study aims to assess whether metabolomics can improve the capacity of clinical models in predicting clinical outcomes in these compensated patients. APPROACH AND RESULTS: This is a nested study from the PREDESCI cohort (an RCT of nonselective beta-blockers vs. placebo in 201 patients with compensated cirrhosis and CSPH), including 167 patients for whom a blood sample was collected. A targeted metabolomic serum analysis, using ultra-high-performance liquid chromatography-mass spectrometry, was performed. Metabolites underwent univariate time-to-event cox regression analysis. Top-ranked metabolites were selected using Log-Rank p -value to generate a stepwise cox model. Comparison between models was done using DeLong test. Eighty-two patients with CSPH were randomized to nonselective beta-blockers and 85 to placebo. Thirty-three patients developed the main endpoint (decompensation/liver-related death). The model, including HVPG, Child-Pugh, and treatment received ( HVPG/Clinical model ), had a C-index of 0.748 (CI95% 0.664-0.827). The addition of 2 metabolites, ceramide (d18:1/22:0) and methionine (HVPG/Clinical/Metabolite model), significantly improved the model's performance [C-index of 0.808 (CI95% 0.735-0.882); p =0.032]. The combination of these 2 metabolites together with Child-Pugh and the type of treatment received (Clinical/Metabolite model) had a C-index of 0.785 (CI95% 0.710-0.860), not significantly different from the HVPG-based models including or not metabolites. CONCLUSIONS: In patients with compensated cirrhosis and CSPH, metabolomics improves the capacity of clinical models and achieves similar predictive capacity than models including HVPG.


Assuntos
Hipertensão Portal , Cirrose Hepática , Humanos , Hipertensão Portal/complicações , Antagonistas Adrenérgicos beta/uso terapêutico , Modelos de Riscos Proporcionais , Pressão na Veia Porta
3.
J Neuroinflammation ; 20(1): 207, 2023 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-37691115

RESUMO

Vascular endothelial function is challenged during cerebral ischemia and reperfusion. The endothelial responses are involved in inflammatory leukocyte attraction, adhesion and infiltration, blood-brain barrier leakage, and angiogenesis. This study investigated gene expression changes in brain endothelial cells after acute ischemic stroke using transcriptomics and translatomics. We isolated brain endothelial mRNA by: (i) translating ribosome affinity purification, enabling immunoprecipitation of brain endothelial ribosome-attached mRNA for translatome sequencing and (ii) isolating CD31+ endothelial cells by fluorescence-activating cell sorting for classical transcriptomic analysis. Both techniques revealed similar pathways regulated by ischemia but they showed specific differences in some transcripts derived from non-endothelial cells. We defined a gene set characterizing the endothelial response to acute stroke (24h) by selecting the differentially expressed genes common to both techniques, thus corresponding with the translatome and minimizing non-endothelial mRNA contamination. Enriched pathways were related to inflammation and immunoregulation, angiogenesis, extracellular matrix, oxidative stress, and lipid trafficking and storage. We validated, by flow cytometry and immunofluorescence, the protein expression of several genes encoding cell surface proteins. The inflammatory response was associated with the endothelial upregulation of genes related to lipid storage functions and we identified lipid droplet biogenesis in the endothelial cells after ischemia. The study reports a robust translatomic signature of brain endothelial cells after acute stroke and identifies enrichment in novel pathways involved in membrane signaling and lipid storage. Altogether these results highlight the endothelial contribution to the inflammatory response, and identify novel molecules that could be targets to improve vascular function after ischemic stroke.


Assuntos
AVC Isquêmico , Acidente Vascular Cerebral , Humanos , AVC Isquêmico/genética , Transcriptoma , Encéfalo , Acidente Vascular Cerebral/genética , Lipídeos
4.
Proc Natl Acad Sci U S A ; 117(23): 12806-12816, 2020 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-32444488

RESUMO

The most prevalent human carcinogen is sunlight-associated ultraviolet (UV), a physiologic dose of which generates thousands of DNA lesions per cell, mostly of two types: cyclobutane pyrimidine dimers (CPDs) and 6-4 photoproducts (6-4PPs). It has not been possible, in living cells, to precisely characterize the respective contributions of these two lesion types to the signals that regulate cell cycle progression, DNA replication, and cell survival. Here we coupled multiparameter flow cytometry with lesion-specific photolyases that eliminate either CPDs or 6-4PPs and determined their respective contributions to DNA damage responses. Strikingly, only 6-4PP lesions activated the ATR-Chk1 DNA damage response pathway. Mechanistically, 6-4PPs, but not CPDs, impeded DNA replication across the genome as revealed by microfluidic-assisted replication track analysis. Furthermore, single-stranded DNA accumulated preferentially at 6-4PPs during DNA replication, indicating selective and prolonged replication blockage at 6-4PPs. These findings suggest that 6-4PPs, although eightfold fewer in number than CPDs, are the trigger for UV-induced DNA damage responses.


Assuntos
Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Dano ao DNA , Replicação do DNA , Dímeros de Pirimidina/genética , Raios Ultravioleta , Animais , Células Cultivadas , Quinase 1 do Ponto de Checagem/metabolismo , Reparo do DNA , Células HCT116 , Humanos
5.
Proc Natl Acad Sci U S A ; 117(45): 28287-28296, 2020 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-33093209

RESUMO

Head and neck squamous cell carcinoma (HNSCC) associated with high-risk human papilloma virus (HPV) infection is a growing clinical problem. The WEE1 kinase inhibitor AZD1775 (WEE1i) overrides cell cycle checkpoints and is being studied in HNSCC regimens. We show that the HPV16 E6/E7 oncoproteins sensitize HNSCC cells to single-agent WEE1i treatment through activation of a FOXM1-CDK1 circuit that drives mitotic gene expression and DNA damage. An isogenic cell system indicated that E6 largely accounts for these phenotypes in ways that extend beyond p53 inactivation. A targeted genomic analysis implicated FOXM1 signaling downstream of E6/E7 expression and analyses of primary tumors and The Cancer Genome Atlas (TCGA) data revealed an activated FOXM1-directed promitotic transcriptional signature in HPV+ versus HPV- HNSCCs. Finally, we demonstrate the causality of FOXM1 in driving WEE1i sensitivity. These data suggest that elevated basal FOXM1 activity predisposes HPV+ HNSCC to WEE1i-induced toxicity and provide mechanistic insights into WEE1i and HPV+ HNSCC therapies.


Assuntos
Proteínas de Ciclo Celular/efeitos dos fármacos , Proteína Forkhead Box M1/metabolismo , Infecções por Papillomavirus/tratamento farmacológico , Proteínas Tirosina Quinases/efeitos dos fármacos , Pirazóis/antagonistas & inibidores , Pirimidinonas/antagonistas & inibidores , Carcinoma de Células Escamosas de Cabeça e Pescoço/tratamento farmacológico , Proteína Quinase CDC2/metabolismo , Pontos de Checagem do Ciclo Celular , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Dano ao DNA/efeitos dos fármacos , Neoplasias de Cabeça e Pescoço , Humanos , Proteínas Oncogênicas Virais/metabolismo , Proteínas E7 de Papillomavirus/metabolismo , Proteínas Tirosina Quinases/metabolismo , Proteínas Repressoras/metabolismo , Regulação para Cima
6.
Am J Transplant ; 21(8): 2749-2761, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33756051

RESUMO

The description of protective humoral and T cell immune responses specific against SARS-CoV-2 has been reported among immunocompetent (IC) individuals developing COVID-19 infection. However, its characterization and determinants of poorer outcomes among the at-risk solid organ transplant (SOT) patient population have not been thoroughly investigated. Cytokine-producing T cell responses, such as IFN-γ, IL-2, IFN-γ/IL-2, IL-6, IL-21, and IL-5, against main immunogenic SARS-CoV-2 antigens and IgM/IgG serological immunity were tracked in SOT (n = 28) during acute infection and at two consecutive time points over the following 40 days of convalescence and were compared to matched IC (n = 16) patients admitted with similar moderate/severe COVID-19. We describe the development of a robust serological and functional T cell immune responses against SARS-CoV-2 among SOT patients, similar to IC patients during early convalescence. However, at the infection onset, SOT displayed lower IgG seroconversion rates (77% vs. 100%; p = .044), despite no differences on IgG titers, and a trend toward decreased SARS-CoV-2-reactive T cell frequencies, especially against the membrane protein (7 [0-34] vs. 113 [15-245], p = .011, 2 [0-9] vs. 45 [5-74], p = .009, and 0 [0-2] vs. 13 [1-24], p = .020, IFN-γ, IL-2, and IFN-γ/IL-2 spots, respectively). In summary, our data suggest that despite a certain initial delay, SOT population achieve comparable functional immune responses than the general population after moderate/severe COVID-19.


Assuntos
COVID-19 , Transplante de Órgãos , Anticorpos Antivirais , Formação de Anticorpos , Convalescença , Humanos , SARS-CoV-2 , Linfócitos T
7.
J Hepatol ; 75(4): 924-934, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34052252

RESUMO

BACKGROUND & AIMS: Porto-sinusoidal vascular disease (PSVD) is a rare vascular liver disease of unknown etiology that causes portal hypertension. It usually affects young individuals and shortens live expectancy. The deregulated pathways involved in PSVD development are unknown and therefore we lack curative treatments. The purpose of this study was to integrate transcriptomic and clinical data by comprehensive network-based modeling in order to uncover altered biological processes in patients with PSVD. METHODS: We obtained liver tissue samples from 20 consecutive patients with PSVD and 21 sex- and age-matched patients with cirrhosis and 13 histologically normal livers (HNL) (initial cohort) and performed transcriptomic analysis. Microarray data were analyzed using weighted gene correlation network analysis to identify clusters of highly correlated genes differently expressed in patients with PSVD. We next evaluated the molecular pathways enriched in patients with PSVD and the core-related genes from the most significantly enriched pathways in patients with PSVD. Our main findings were validated using RNA sequencing in a different cohort of PSVD, cirrhosis and HNL (n = 8 for each group). RESULTS: Patients with PSVD have a distinctive genetic profile enriched mainly in canonical pathways involving hemostasis and coagulation but also lipid metabolism and oxidative phosphorylation. Serpin family (SERPINC1), the apolipoproteins (APOA, APOB, APOC), ATP synthases (ATP5G1, ATP5B), fibrinogen genes (FGB, FGA) and alpha-2-macroglobulin were identified as highly connective genes that may have an important role in PSVD pathogenesis. CONCLUSION: PSVD has a unique transcriptomic profile and we have identified deregulation of pathways involved in vascular homeostasis as the main pathogenic event of disease development. LAY SUMMARY: Porto-sinusoidal vascular disease is a rare but life-shortening disease that affects mainly young people. Knowledge of the disrupted pathways involved in its development will help to identify novel therapeutic targets and new treatments. Using a systems biology approach, we identify that pathways regulating endothelial function and tone may act as drivers of porto-sinusoidal vascular disease.


Assuntos
Expressão Gênica/genética , Redes Reguladoras de Genes/genética , Doenças Vasculares/genética , Adulto , Feminino , Expressão Gênica/imunologia , Redes Reguladoras de Genes/imunologia , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Vasculares/fisiopatologia
8.
J Hepatol ; 75(6): 1409-1419, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34437910

RESUMO

BACKGROUND & AIMS: Management of long-term immunosuppression following liver transplantation (LT) remains empirical. Surveillance liver biopsies in combination with transcriptional profiling could overcome this challenge by identifying recipients with active alloimmune-mediated liver damage despite normal liver tests, but this approach lacks applicability. Our aim was to investigate the utility of non-invasive tools for the stratification of stable long-term survivors of LT, according to their immunological risk and need for immunosuppression. METHODS: We conducted a cross-sectional multicentre study of 190 adult LT recipients assessed to determine their eligibility to participate in an immunosuppression withdrawal trial. Patients had stable liver allograft function and had been transplanted for non-autoimmune non-replicative viral liver disease >3 years before inclusion. We performed histological, immunogenetic and serological studies and measured the intrahepatic transcript levels of an 11-gene classifier highly specific for T cell-mediated rejection (TCMR). RESULTS: In this cohort, 35.8% of patients harboured clinically silent fibro-inflammatory liver lesions (13.7% had mild damage and 22.1% had moderate-to-severe damage). The severity of liver allograft damage was positively associated with TCMR-related transcripts, class II donor-specific antibodies (DSAs), ALT, AST, and liver stiffness measurement (LSM), and negatively correlated with serum creatinine and tacrolimus trough levels. Liver biopsies were stratified according to their TCMR transcript levels using a cut-off derived from biopsies with clinically significant TCMR. Two multivariable prediction models, integrating ALT+LSM or ALT+class II DSAs, had a high discriminative capacity for classifying patients with or without alloimmune damage. The latter model performed well in an independent cohort of 156 liver biopsies obtained from paediatric liver recipients with similar inclusion/exclusion criteria. CONCLUSION: ALT, class II DSAs and LSM are valuable tools to non-invasively identify stable LT recipients without significant underlying alloimmunity who could benefit from minimisation of immunosuppression. LAY SUMMARY: A large proportion of liver transplant patients with normal liver tests have inflammatory liver lesions, which in 17% of cases are molecularly indistinguishable from those seen at the time of rejection. ALT, class II donor-specific antibodies and liver stiffness are useful in identifying patients with this form of subclinical rejection. We propose these markers as a useful tool to help clinicians determine if the immunosuppression administered is adequate.


Assuntos
Hemocromatose/diagnóstico , Transplante de Fígado/efeitos adversos , Medição de Risco/normas , Adulto , Idoso , Biópsia/métodos , Biópsia/estatística & dados numéricos , Estudos Transversais , Feminino , Hemocromatose/epidemiologia , Humanos , Transplante de Fígado/métodos , Transplante de Fígado/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Medição de Risco/métodos , Medição de Risco/estatística & dados numéricos , Tolerância ao Transplante
9.
J Biol Chem ; 291(47): 24487-24503, 2016 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-27672210

RESUMO

The WRN helicase/exonuclease is mutated in Werner syndrome of genomic instability and premature aging. WRN-depleted fibroblasts, although remaining largely viable, have a reduced capacity to maintain replication forks active during a transient hydroxyurea-induced arrest. A strand exchange protein, RAD51, is also required for replication fork maintenance, and here we show that recruitment of RAD51 to stalled forks is reduced in the absence of WRN. We performed a siRNA screen for genes that are required for viability of WRN-depleted cells after hydroxyurea treatment, and identified HDAC1, a member of the class I histone deacetylase family. One of the functions of HDAC1, which it performs together with a close homolog HDAC2, is deacetylation of new histone H4 deposited at replication forks. We show that HDAC1 depletion exacerbates defects in fork reactivation and progression after hydroxyurea treatment observed in WRN- or RAD51-deficient cells. The additive WRN, HDAC1 loss-of-function phenotype is also observed with a catalytic mutant of HDAC1; however, it does not correlate with changes in histone H4 deacetylation at replication forks. On the other hand, inhibition of histone deacetylation by an inhibitor specific to HDACs 1-3, CI-994, correlates with increased processing of newly synthesized DNA strands in hydroxyurea-stalled forks. WRN co-precipitates with HDAC1 and HDAC2. Taken together, our findings indicate that WRN interacts with HDACs 1 and 2 to facilitate activity of stalled replication forks under conditions of replication stress.


Assuntos
Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Replicação do DNA/efeitos dos fármacos , Histona Desacetilase 1/metabolismo , Hidroxiureia/farmacologia , Helicase da Síndrome de Werner/metabolismo , Pontos de Checagem do Ciclo Celular/genética , Linhagem Celular Transformada , Replicação do DNA/genética , Histona Desacetilase 1/genética , Histona Desacetilase 2/genética , Histona Desacetilase 2/metabolismo , Histona Desacetilases/genética , Histona Desacetilases/metabolismo , Humanos , Rad51 Recombinase/genética , Rad51 Recombinase/metabolismo , Helicase da Síndrome de Werner/genética
10.
Methods ; 108: 99-110, 2016 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-27130890

RESUMO

Functional studies of the roles that DNA helicases play in human cells have benefited immensely from DNA fiber (or single molecule) technologies, which enable us to discern minute differences in behaviors of individual replication forks in genomic DNA in vivo. DNA fiber technologies are a group of methods that use different approaches to unravel and stretch genomic DNA to its contour length, and display it on a glass surface in order to immuno-stain nucleoside analog incorporation into DNA to reveal tracks (or tracts) of replication. We have previously adopted a microfluidic approach to DNA stretching and used it to analyze DNA replication. This method was introduced under the moniker maRTA or microfluidic-assisted Replication Track Analysis, and we have since used it to analyze roles of the RECQ helicases WRN and BLM, and other proteins in normal and perturbed replication. Here we describe a novel application of maRTA to detect and measure repair of DNA damage produced by three different agents relevant to etiology or therapy of cancer: methyl-methanesulfonate, UV irradiation, and mitomycin C. Moreover, we demonstrate the utility of this method by analyzing DNA repair in cells with reduced levels of WRN or of the base excision repair protein XRCC1.


Assuntos
DNA Helicases/genética , Reparo do DNA/genética , Replicação do DNA/genética , Técnicas Analíticas Microfluídicas/métodos , Animais , Dano ao DNA/genética , DNA Helicases/química , Humanos , Camundongos , Proteína 1 Complementadora Cruzada de Reparo de Raio-X/genética
11.
PLoS Genet ; 9(7): e1003639, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23874233

RESUMO

Telomeres are chromosome end structures and are essential for maintenance of genome stability. Highly repetitive telomere sequences appear to be susceptible to oxidative stress-induced damage. Oxidation may therefore have a severe impact on telomere integrity and function. A wide spectrum of oxidative pyrimidine-derivatives has been reported, including thymine glycol (Tg), that are primarily removed by a DNA glycosylase, Endonuclease III-like protein 1 (Nth1). Here, we investigate the effect of Nth1 deficiency on telomere integrity in mice. Nth1 null (Nth1(-/-) ) mouse tissues and primary MEFs harbor higher levels of Endonuclease III-sensitive DNA lesions at telomeric repeats, in comparison to a non-telomeric locus. Furthermore, oxidative DNA damage induced by acute exposure to an oxidant is repaired slowly at telomeres in Nth1(-/-) MEFs. Although telomere length is not affected in the hematopoietic tissues of Nth1(-/-) adult mice, telomeres suffer from attrition and increased recombination and DNA damage foci formation in Nth1(-/-) bone marrow cells that are stimulated ex vivo in the presence of 20% oxygen. Nth1 deficiency also enhances telomere fragility in mice. Lastly, in a telomerase null background, Nth1(-/-) bone marrow cells undergo severe telomere loss at some chromosome ends and cell apoptosis upon replicative stress. These results suggest that Nth1 plays an important role in telomere maintenance and base repair against oxidative stress-induced base modifications. The fact that telomerase deficiency can exacerbate telomere shortening in Nth1 deficient mouse cells supports that base excision repair cooperates with telomerase to maintain telomere integrity.


Assuntos
Dano ao DNA , Desoxirribonuclease (Dímero de Pirimidina)/genética , Instabilidade Genômica , Telômero/genética , Animais , Células da Medula Óssea/metabolismo , Células da Medula Óssea/patologia , Cromossomos/genética , Cromossomos/metabolismo , Cromossomos/ultraestrutura , Camundongos , Camundongos Knockout , Estresse Oxidativo , Oxigênio/metabolismo , Recombinação Genética , Sequências Repetitivas de Ácido Nucleico/genética , Telomerase/genética , Telomerase/metabolismo , Telômero/metabolismo , Telômero/patologia
12.
Proc Natl Acad Sci U S A ; 110(22): 8954-9, 2013 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-23671119

RESUMO

Cyclin-dependent kinases (Cdks) coordinate cell division, and their activities are tightly controlled. Phosphorylation of threonine 14 (T14) and tyrosine 15 (Y15) inhibits Cdks and regulates their activities in numerous physiologic contexts. Although the roles of Cdk1 inhibitory phosphorylation during mitosis are well described, studies of Cdk2 inhibitory phosphorylation during S phrase have largely been indirect. To specifically study the functions of Cdk2 inhibitory phosphorylation, we used gene targeting to make an endogenous Cdk2 knockin allele in human cells, termed Cdk2AF, which prevents Cdk2 T14 and Y15 phosphorylation. Cdk2AF caused premature S-phase entry, rapid cyclin E degradation, abnormal DNA replication, and genome instability. Cdk2AF cells also exhibited strikingly abnormal responses to replication stress, accumulated irreparable DNA damage, and permanently exited the cell cycle after transient exposure to S-phase inhibitors. Our results reveal the specific and essential roles of Cdk2 inhibitory phosphorylation in the successful execution of the replication stress checkpoint response and in maintaining genome integrity.


Assuntos
Quinase 2 Dependente de Ciclina/metabolismo , Replicação do DNA/fisiologia , Fase S/fisiologia , Transdução de Sinais/fisiologia , Proteínas de Ciclo Celular/metabolismo , Células Cultivadas , Ciclina E/metabolismo , Quinase 2 Dependente de Ciclina/genética , Dano ao DNA/fisiologia , Proteínas de Ligação a DNA/metabolismo , Eletroforese em Gel de Campo Pulsado , Citometria de Fluxo , Técnicas de Introdução de Genes , Instabilidade Genômica/fisiologia , Humanos , Microfluídica , Proteínas Nucleares/metabolismo , Fosforilação , Proteínas Tirosina Quinases/metabolismo , Interferência de RNA , RNA Interferente Pequeno/genética , Pontos de Checagem da Fase S do Ciclo Celular/fisiologia , Fatores de Transcrição/metabolismo
13.
Geroscience ; 46(2): 2771-2775, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37603195

RESUMO

A progeroid family was found to harbor a pathogenic variant in the CASP5 gene that encodes inflammatory caspase 5. Caspase 5-depleted fibroblasts exhibited hyper-activation of inflammatory cytokines in response to pro-inflammatory stimuli. Long-term intermittent hyper-inflammatory response is likely the cause of the accelerated aging phenotype comprised of earlier onset of common aging diseases, supporting inflammaging as a potential common disease mechanism of progeroid syndromes and possibly normative aging.


Assuntos
Progéria , Humanos , Progéria/genética , Fenótipo
14.
Inflamm Bowel Dis ; 30(2): 167-182, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-37536268

RESUMO

BACKGROUND AND AIMS: Inflammatory bowel disease (IBD) is a prevalent chronic noncurable disease associated with profound metabolic changes. The discovery of novel molecular indicators for unraveling IBD etiopathogenesis and the diagnosis and prognosis of IBD is therefore pivotal. We sought to determine the distinctive metabolic signatures from the different IBD subgroups before treatment initiation. METHODS: Serum and urine samples from newly diagnosed treatment-naïve IBD patients and age and sex-matched healthy control (HC) individuals were investigated using proton nuclear magnetic resonance spectroscopy. Metabolic differences were identified based on univariate and multivariate statistical analyses. RESULTS: A total of 137 Crohn's disease patients, 202 ulcerative colitis patients, and 338 HC individuals were included. In the IBD cohort, several distinguishable metabolites were detected within each subgroup comparison. Most of the differences revealed alterations in energy and amino acid metabolism in IBD patients, with an increased demand of the body for energy mainly through the ketone bodies. As compared with HC individuals, differences in metabolites were more marked and numerous in Crohn's disease than in ulcerative colitis patients, and in serum than in urine. In addition, clustering analysis revealed 3 distinct patient profiles with notable differences among them based on the analysis of their clinical, anthropometric, and metabolomic variables. However, relevant phenotypical differences were not found among these 3 clusters. CONCLUSIONS: This study highlights the molecular alterations present within the different subgroups of newly diagnosed treatment-naïve IBD patients. The metabolomic profile of these patients may provide further understanding of pathogenic mechanisms of IBD subgroups. Serum metabotype seemed to be especially sensitive to the onset of IBD.


Assuntos
Colite Ulcerativa , Doença de Crohn , Doenças Inflamatórias Intestinais , Humanos , Colite Ulcerativa/diagnóstico , Doença de Crohn/diagnóstico , Metabolômica , Intestinos
15.
J Biol Chem ; 287(26): 21980-91, 2012 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-22570476

RESUMO

Dna2 is an essential helicase/nuclease that is postulated to cleave long DNA flaps that escape FEN1 activity during Okazaki fragment (OF) maturation in yeast. We previously demonstrated that the human Dna2 orthologue (hDna2) localizes to the nucleus and contributes to genomic stability. Here we investigated the role hDna2 plays in DNA replication. We show that Dna2 associates with the replisome protein And-1 in a cell cycle-dependent manner. Depletion of hDna2 resulted in S/G(2) phase-specific DNA damage as evidenced by increased γ-H2AX, replication protein A foci, and Chk1 kinase phosphorylation, a readout for activation of the ATR-mediated S phase checkpoint. In addition, we observed reduced origin firing in hDna2-depleted cells consistent with Chk1 activation. We next examined the impact of hDna2 on OF maturation and replication fork progression in human cells. As expected, FEN1 depletion led to a significant reduction in OF maturation. Strikingly, the reduction in OF maturation had no impact on replication fork progression, indicating that fork movement is not tightly coupled to lagging strand maturation. Analysis of hDna2-depleted cells failed to reveal a defect in OF maturation or replication fork progression. Prior work in yeast demonstrated that ectopic expression of FEN1 rescues Dna2 defects. In contrast, we found that FEN1 expression in hDna2-depleted cells failed to rescue genomic instability. These findings suggest that the genomic instability observed in hDna2-depleted cells does not arise from defective OF maturation and that hDna2 plays a role in DNA replication that is distinct from FEN1 and OF maturation.


Assuntos
DNA Helicases/fisiologia , Replicação do DNA , DNA , Ciclo Celular , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Cromatina/metabolismo , DNA/química , Dano ao DNA , DNA Helicases/química , Reparo do DNA , Regulação da Expressão Gênica , Células HeLa , Humanos , Cinética , Testes para Micronúcleos , Microscopia de Fluorescência/métodos
16.
Nucleic Acids Res ; 39(6): 2103-15, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21062817

RESUMO

Many mutation events in microsatellite DNA sequences were traced to the first embryonic divisions. It was not known what makes the first replication cycles of embryonic DNA different from subsequent replication cycles. Here we demonstrate that an unusual replication mode is involved in the first cycle of replication of DNA introduced in mammalian cells. This alternative replication starts at random positions, and occurs before the chromatin is fully assembled. It is detected in various cell lines and primary cells. The presence of single-stranded regions increases the efficiency of this alternative replication mode. The alternative replication cannot progress through the A/T-rich FRA16B fragile site, while the regular replication mode is not affected by it. A/T-rich microsatellites are associated with the majority of chromosomal breakpoints in cancer. We suggest that the alternative replication mode may be initiated at the regions with immature chromatin structure in embryonic and cancer cells resulting in increased genomic instability. This work demonstrates, for the first time, differences in the replication progression during the first and subsequent replication cycles in mammalian cells.


Assuntos
Replicação do DNA , Sequência Rica em At , Animais , Antígenos Transformantes de Poliomavirus/metabolismo , Células COS , Chlorocebus aethiops , Sítios Frágeis do Cromossomo , DNA/química , Dano ao DNA , Metilação de DNA , Células HEK293 , Células HeLa , Humanos , Repetições de Microssatélites , Nucleossomos/química , Recombinação Genética , Origem de Replicação , Fase S/genética , Vírus 40 dos Símios/genética , Transfecção
17.
JMIR Ment Health ; 10: e40342, 2023 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-36649063

RESUMO

BACKGROUND: Disturbed heart dynamics in depression seriously increases mortality risk. Heart rate variability (HRV) is a rich source of information for studying this dynamics. This paper is a meta-analytic review with methodological commentary of the application of nonlinear analysis of HRV and its possibility to address cardiovascular diseases in depression. OBJECTIVE: This paper aimed to appeal for the introduction of cardiological screening to patients with depression, because it is still far from established practice. The other (main) objective of the paper was to show that nonlinear methods in HRV analysis give better results than standard ones. METHODS: We systematically searched on the web for papers on nonlinear analyses of HRV in depression, in line with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) 2020 framework recommendations. We scrutinized the chosen publications and performed random-effects meta-analysis, using the esci module in jamovi software where standardized effect sizes (ESs) are corrected to yield the proof of the practical utility of their results. RESULTS: In all, 26 publications on the connection of nonlinear HRV measures and depression meeting our inclusion criteria were selected, examining a total of 1537 patients diagnosed with depression and 1041 healthy controls (N=2578). The overall ES (unbiased) was 1.03 (95% CI 0.703-1.35; diamond ratio 3.60). We performed 3 more meta-analytic comparisons, demonstrating the overall effectiveness of 3 groups of nonlinear analysis: detrended fluctuation analysis (overall ES 0.364, 95% CI 0.237-0.491), entropy-based measures (overall ES 1.05, 95% CI 0.572-1.52), and all other nonlinear measures (overall ES 0.702, 95% CI 0.422-0.982). The effectiveness of the applied methods of electrocardiogram analysis was compared and discussed in the light of detection and prevention of depression-related cardiovascular risk. CONCLUSIONS: We compared the ESs of nonlinear and conventional time and spectral methods (found in the literature) and demonstrated that those of the former are larger, which recommends their use for the early screening of cardiovascular abnormalities in patients with depression to prevent possible deleterious events.

18.
Nat Commun ; 14(1): 7471, 2023 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-37978290

RESUMO

Acute inflammation can either resolve through immunosuppression or persist, leading to chronic inflammation. These transitions are driven by distinct molecular and metabolic reprogramming of immune cells. The anti-diabetic drug Metformin inhibits acute and chronic inflammation through mechanisms still not fully understood. Here, we report that the anti-inflammatory and reactive-oxygen-species-inhibiting effects of Metformin depend on the expression of the plasticity factor ZEB1 in macrophages. Using mice lacking Zeb1 in their myeloid cells and human patient samples, we show that ZEB1 plays a dual role, being essential in both initiating and resolving inflammation by inducing macrophages to transition into an immunosuppressed state. ZEB1 mediates these diverging effects in inflammation and immunosuppression by modulating mitochondrial content through activation of autophagy and inhibition of mitochondrial protein translation. During the transition from inflammation to immunosuppression, Metformin mimics the metabolic reprogramming of myeloid cells induced by ZEB1. Mechanistically, in immunosuppression, ZEB1 inhibits amino acid uptake, leading to downregulation of mTORC1 signalling and a decrease in mitochondrial translation in macrophages. These results identify ZEB1 as a driver of myeloid cell metabolic plasticity, suggesting that targeting its expression and function could serve as a strategy to modulate dysregulated inflammation and immunosuppression.


Assuntos
Macrófagos , Metformina , Humanos , Animais , Camundongos , Macrófagos/metabolismo , Células Mieloides , Inflamação/metabolismo , Metformina/farmacologia , Terapia de Imunossupressão
19.
EBioMedicine ; 91: 104555, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37054630

RESUMO

BACKGROUND: Reprogramming of immunosuppressive tumor-associated macrophages (TAMs) presents an attractive therapeutic strategy in cancer. The aim of this study was to explore the role of macrophage CD5L protein in TAM activity and assess its potential as a therapeutic target. METHODS: Monoclonal antibodies (mAbs) against recombinant CD5L were raised by subcutaneous immunization of BALB/c mice. Peripheral blood monocytes were isolated from healthy donors and stimulated with IFN/LPS, IL4, IL10, and conditioned medium (CM) from different cancer cell lines in the presence of anti-CD5L mAb or controls. Subsequently, phenotypic markers, including CD5L, were quantified by flow cytometry, IF and RT-qPCR. Macrophage CD5L protein expression was studied in 55 human papillary lung adenocarcinoma (PAC) samples by IHC and IF. Anti-CD5L mAb and isotype control were administered intraperitoneally into a syngeneic Lewis Lung Carcinoma mouse model and tumor growth was measured. Tumor microenvironment (TME) changes were determined by flow cytometry, IHC, IF, Luminex, RNAseq and RT-qPCR. FINDINGS: Cancer cell lines CM induced an immunosuppressive phenotype (increase in CD163, CD206, MERTK, VEGF and CD5L) in cultured macrophages. Accordingly, high TAM expression of CD5L in PAC was associated with poor patient outcome (Log-rank (Mantel-Cox) test p = 0.02). We raised a new anti-CD5L mAb that blocked the immunosuppressive phenotype of macrophages in vitro. Its administration in vivo inhibited tumor progression of lung cancer by altering the intratumoral myeloid cell population profile and CD4+ T-cell exhaustion phenotype, thereby significantly modifying the TME and increasing the inflammatory milieu. INTERPRETATION: CD5L protein plays a key function in modulating the activity of macrophages and their interactions within the TME, which supports its role as a therapeutic target in cancer immunotherapy. FUNDING: For a full list of funding bodies, please see the Acknowledgements.


Assuntos
Neoplasias Pulmonares , Macrófagos , Animais , Humanos , Camundongos , Linhagem Celular Tumoral , Imunoterapia , Neoplasias Pulmonares/terapia , Macrófagos/metabolismo , Monócitos , Células Mieloides/patologia , Microambiente Tumoral
20.
Exp Dermatol ; 21(1): 57-60, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21995276

RESUMO

PCR-based clonality assay of rearranged T-cell receptor genes gamma and beta (TCRG and TCRB) in a number of cases could be essential to discriminate between cutaneous T-cell lymphomas and reactive lymphoproliferative lesions in the skin. However, extraction of good-quality DNA from skin specimens (especially formalin-fixed paraffin-embedded) remains a challenge. Common procedures, being labour-intensive and time-consuming and requiring toxic solvents such as phenol and chloroform, still may end up with DNA sample of insufficient quality. We herewith present a simple and efficient method for DNA isolation based on ammonia extraction of tissue, followed by neutralization and simultaneous salting out of proteins with acetic acid. We have analysed 30 samples - 24 fresh (16 skin, two spleen and six lymph node) and six paraffin-embedded. Standard procedure (proteinase K digestion, followed by phenol/chloroform extraction) has been carried out simultaneously. We observed good PCR signal for TCRG rearrangements in 30 samples processed with the new protocol and only in 20 extracted with proteinase K/phenol/chloroform. For TCRB, the success rate was 29 of 30 with the new protocol, compared to 11 of 30 with conventional protocol. The proposed method of DNA extraction should improve the value of T-cell clonality assay, because insufficient DNA quality and quantity may bias analysis towards monoclonality and therefore cause false-positive results.


Assuntos
DNA/isolamento & purificação , Pele/química , Ácido Acético/química , Amônia/química , Rearranjo Gênico do Linfócito T , Humanos , Inclusão em Parafina
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