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1.
Nat Immunol ; 25(6): 1046-1058, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38816618

RESUMO

The durability of an antitumor immune response is mediated in part by the persistence of progenitor exhausted CD8+ T cells (Tpex). Tpex serve as a resource for replenishing effector T cells and preserve their quantity through self-renewal. However, it is unknown how T cell receptor (TCR) engagement affects the self-renewal capacity of Tpex in settings of continued antigen exposure. Here we use a Lewis lung carcinoma model that elicits either optimal or attenuated TCR signaling in CD8+ T cells to show that formation of Tpex in tumor-draining lymph nodes and their intratumoral persistence is dependent on optimal TCR engagement. Notably, attenuated TCR stimulation accelerates the terminal differentiation of optimally primed Tpex. This TCR-reinforced Tpex development and self-renewal is coupled to proximal positioning to dendritic cells and epigenetic imprinting involving increased chromatin accessibility at Egr2 and Tcf1 target loci. Collectively, this study highlights the critical function of TCR engagement in sustaining Tpex during tumor progression.


Assuntos
Linfócitos T CD8-Positivos , Carcinoma Pulmonar de Lewis , Fator 1-alfa Nuclear de Hepatócito , Camundongos Endogâmicos C57BL , Receptores de Antígenos de Linfócitos T , Animais , Linfócitos T CD8-Positivos/imunologia , Receptores de Antígenos de Linfócitos T/metabolismo , Receptores de Antígenos de Linfócitos T/imunologia , Camundongos , Carcinoma Pulmonar de Lewis/imunologia , Carcinoma Pulmonar de Lewis/patologia , Carcinoma Pulmonar de Lewis/metabolismo , Fator 1-alfa Nuclear de Hepatócito/metabolismo , Diferenciação Celular/imunologia , Células Dendríticas/imunologia , Transdução de Sinais/imunologia , Camundongos Knockout , Ativação Linfocitária/imunologia , Autorrenovação Celular , Camundongos Transgênicos , Proteína 2 de Resposta de Crescimento Precoce
2.
Nat Immunol ; 23(1): 86-98, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34845392

RESUMO

Ineffective antibody-mediated responses are a key characteristic of chronic viral infection. However, our understanding of the intrinsic mechanisms that drive this dysregulation are unclear. Here, we identify that targeting the epigenetic modifier BMI-1 in mice improves humoral responses to chronic lymphocytic choriomeningitis virus. BMI-1 was upregulated by germinal center B cells in chronic viral infection, correlating with changes to the accessible chromatin landscape, compared to acute infection. B cell-intrinsic deletion of Bmi1 accelerated viral clearance, reduced splenomegaly and restored splenic architecture. Deletion of Bmi1 restored c-Myc expression in B cells, concomitant with improved quality of antibody and coupled with reduced antibody-secreting cell numbers. Specifically, BMI-1-deficiency induced antibody with increased neutralizing capacity and enhanced antibody-dependent effector function. Using a small molecule inhibitor to murine BMI-1, we could deplete antibody-secreting cells and prohibit detrimental immune complex formation in vivo. This study defines BMI-1 as a crucial immune modifier that controls antibody-mediated responses in chronic infection.


Assuntos
Linfócitos B/imunologia , Imunidade Humoral/imunologia , Coriomeningite Linfocítica/imunologia , Vírus da Coriomeningite Linfocítica/imunologia , Complexo Repressor Polycomb 1/imunologia , Proteínas Proto-Oncogênicas/imunologia , Imunidade Adaptativa/imunologia , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Formação de Anticorpos/imunologia , Feminino , Centro Germinativo/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL
3.
Immunity ; 56(4): 847-863.e8, 2023 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-36958335

RESUMO

Seasonal influenza vaccination elicits hemagglutinin (HA)-specific memory B (Bmem) cells, and although multiple Bmem cell populations have been characterized, considerable heterogeneity exists. We found that HA-specific human Bmem cells differed in the expression of surface marker FcRL5 and transcriptional factor T-bet. FcRL5+T-bet+ Bmem cells were transcriptionally similar to effector-like memory cells, while T-betnegFcRL5neg Bmem cells exhibited stem-like central memory properties. FcRL5+ Bmem cells did not express plasma-cell-commitment factors but did express transcriptional, epigenetic, metabolic, and functional programs that poised these cells for antibody production. Accordingly, HA+ T-bet+ Bmem cells at day 7 post-vaccination expressed intracellular immunoglobulin, and tonsil-derived FcRL5+ Bmem cells differentiated more rapidly into antibody-secreting cells (ASCs) in vitro. The T-bet+ Bmem cell response positively correlated with long-lived humoral immunity, and clonotypes from T-bet+ Bmem cells were represented in the secondary ASC response to repeat vaccination, suggesting that this effector-like population predicts influenza vaccine durability and recall potential.


Assuntos
Vacinas contra Influenza , Influenza Humana , Humanos , Influenza Humana/prevenção & controle , Formação de Anticorpos , Células B de Memória , Vacinação , Memória Imunológica , Anticorpos Antivirais
4.
Nat Immunol ; 20(8): 1071-1082, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31263277

RESUMO

Systemic lupus erythematosus (SLE) is characterized by the expansion of extrafollicular pathogenic B cells derived from newly activated naive cells. Although these cells express distinct markers, their epigenetic architecture and how it contributes to SLE remain poorly understood. To address this, we determined the DNA methylomes, chromatin accessibility profiles and transcriptomes from five human B cell subsets, including a newly defined effector B cell subset, from subjects with SLE and healthy controls. Our data define a differentiation hierarchy for the subsets and elucidate the epigenetic and transcriptional differences between effector and memory B cells. Importantly, an SLE molecular signature was already established in resting naive cells and was dominated by enrichment of accessible chromatin in motifs for AP-1 and EGR transcription factors. Together, these factors acted in synergy with T-BET to shape the epigenome of expanded SLE effector B cell subsets. Thus, our data define the molecular foundation of pathogenic B cell dysfunction in SLE.


Assuntos
Subpopulações de Linfócitos B/patologia , Metilação de DNA/genética , Epigênese Genética/genética , Lúpus Eritematoso Sistêmico/genética , Subpopulações de Linfócitos B/imunologia , Montagem e Desmontagem da Cromatina/fisiologia , Fatores de Transcrição de Resposta de Crescimento Precoce/genética , Humanos , Lúpus Eritematoso Sistêmico/imunologia , Fator de Transcrição AP-1/genética , Transcriptoma/genética
5.
Proc Natl Acad Sci U S A ; 120(14): e2219086120, 2023 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-36972454

RESUMO

Regulatory T cell (Treg) therapy is a promising approach to improve outcomes in transplantation and autoimmunity. In conventional T cell therapy, chronic stimulation can result in poor in vivo function, a phenomenon termed exhaustion. Whether or not Tregs are also susceptible to exhaustion, and if so, if this would limit their therapeutic effect, was unknown. To "benchmark" exhaustion in human Tregs, we used a method known to induce exhaustion in conventional T cells: expression of a tonic-signaling chimeric antigen receptor (TS-CAR). We found that TS-CAR-expressing Tregs rapidly acquired a phenotype that resembled exhaustion and had major changes in their transcriptome, metabolism, and epigenome. Similar to conventional T cells, TS-CAR Tregs upregulated expression of inhibitory receptors and transcription factors such as PD-1, TIM3, TOX and BLIMP1, and displayed a global increase in chromatin accessibility-enriched AP-1 family transcription factor binding sites. However, they also displayed Treg-specific changes such as high expression of 4-1BB, LAP, and GARP. DNA methylation analysis and comparison to a CD8+ T cell-based multipotency index showed that Tregs naturally exist in a relatively differentiated state, with further TS-CAR-induced changes. Functionally, TS-CAR Tregs remained stable and suppressive in vitro but were nonfunctional in vivo, as tested in a model of xenogeneic graft-versus-host disease. These data are the first comprehensive investigation of exhaustion in Tregs and reveal key similarities and differences with exhausted conventional T cells. The finding that human Tregs are susceptible to chronic stimulation-driven dysfunction has important implications for the design of CAR Treg adoptive immunotherapy strategies.


Assuntos
Doença Enxerto-Hospedeiro , Receptores de Antígenos Quiméricos , Humanos , Linfócitos T Reguladores , Exaustão das Células T , Imunoterapia Adotiva/métodos , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/metabolismo
6.
J Immunol ; 209(9): 1778-1787, 2022 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-36162870

RESUMO

Lung tissue-resident memory T cells are crucial mediators of cellular immunity against respiratory viruses; however, their gradual decline hinders the development of T cell-based vaccines against respiratory pathogens. Recently, studies using adenovirus (Ad)-based vaccine vectors have shown that the number of protective lung-resident CD8+ TRMs can be maintained long term. In this article, we show that immunization of mice with a replication-deficient Ad serotype 5 expressing influenza (A/Puerto Rico/8/34) nucleoprotein (AdNP) generates a long-lived lung TRM pool that is transcriptionally indistinct from those generated during a primary influenza infection. In addition, we demonstrate that CD4+ T cells contribute to the long-term maintenance of AdNP-induced CD8+ TRMs. Using a lineage tracing approach, we identify alveolar macrophages as a cell source of persistent NP Ag after immunization with AdNP. Importantly, depletion of alveolar macrophages after AdNP immunization resulted in significantly reduced numbers of NP-specific CD8+ TRMs in the lungs and airways. Combined, our results provide further insight to the mechanisms governing the enhanced longevity of Ag-specific CD8+ lung TRMs observed after immunization with recombinant Ad.


Assuntos
Vacinas contra Influenza , Influenza Humana , Animais , Linfócitos T CD8-Positivos , Proteínas de Homeodomínio , Humanos , Memória Imunológica , Pulmão , Macrófagos Alveolares , Camundongos , Proteínas do Tecido Nervoso , Nucleoproteínas
7.
Appl Microbiol Biotechnol ; 108(1): 19, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38170315

RESUMO

In this research, a recombinant Bacillus Calmette Guerin (rBCG) vector vaccine carrying a human IL-2 and EBV BZLF1 fusion gene (IL-2-BZLF1-rBCG) was constructed. The IL-2-BZLF1-rBCG construct was successfully generated and stably expressed the IL-2 and BZLF1 proteins. IL-2-BZLF1-rBCG activated the immune system and promoted the secretion of IFN-γ and TNF-α by CD4+ and CD8+ T cells. IL-2-BZLF1-rBCG activated lymphocytes to effectively kill EBV-positive NPC cells in vitro. Additionally, IL-2-BZLF1-rBCG stimulated the proliferation of NK cells and lymphocytes in vivo, activated related immune responses, and effectively treated EBV-positive NPC. The immune response to and pharmacological effect of IL-2-BZLF1-rBCG were explored in vitro and in vivo to provide a theoretical and experimental basis for the prevention and treatment of EBV-positive tumors with an rBCG vector vaccine. KEY POINTS: • rBCG with human IL-2 and BZLF1 of EB virus was constructed • The IL-2-BZLF1 fusion gene was stably expressed with rBCG • rBCG with IL-2-BZLF1 has an obvious immune response in vitro and in vivo.


Assuntos
Mycobacterium bovis , Neoplasias , Humanos , Interleucina-2/genética , Linfócitos T CD8-Positivos , Mycobacterium bovis/genética , Vacina BCG , Transativadores/genética
8.
Int J Mol Sci ; 24(19)2023 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-37834145

RESUMO

Chlorophyll is an indispensable photoreceptor in plant photosynthesis. Its anabolic imbalance is detrimental to individual growth and development. As an essential epigenetic modification, DNA methylation can induce phenotypic variations, such as leaf color transformation, by regulating gene expression. Albino line XN1376B is a natural mutation of winter wheat cultivar XN1376; however, the regulatory mechanism of its albinism is still unclear. In this study, we found that low temperatures induced albinism in XN1376B. The number of chloroplasts decreased as the phenomenon of bleaching intensified and the fence tissue and sponge tissue slowly dissolved. We identified six distinct TaPOR (protochlorophyllide oxidoreductase) genes in the wheat genome, and TaPOR2D was deemed to be related to the phenomenon of albinism based on the expression in different color leaves (green leaves, white leaves and returned green leaves) and the analysis of promoters' cis-acting elements. TaPOR2D was localized to chloroplasts. TaPOR2D overexpression (TaPOR2D-OE) enhanced the chlorophyll significantly in Arabidopsis, especially at two weeks; the amount of chlorophyll was 6.46 mg/L higher than in WT. The methylation rate of the TaPOR2D promoter in low-temperature albino leaves is as high as 93%, whereas there was no methylation in green leaves. Correspondingly, three DNA methyltransferase genes (TaMET1, TaDRM and TaCMT) were up-regulated in white leaves. Our study clarified that the expression of TaPOR2D is associated with its promoter methylation at a low temperature; it affects the level of chlorophyll accumulation, which probably causes the abnormal development of plant chloroplasts in albino wheat XN1376B. The results provide a theoretical basis for in-depth analysis of the regulation of development of plant chloroplasts and color variation in wheat XN1376B leaves.


Assuntos
Albinismo , Arabidopsis , Clorofila/metabolismo , Triticum/metabolismo , Temperatura , Fotossíntese/genética , Metilação de DNA , Arabidopsis/metabolismo , Albinismo/genética , Albinismo/metabolismo , Folhas de Planta/metabolismo
9.
Angew Chem Int Ed Engl ; 61(33): e202204395, 2022 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-35691827

RESUMO

The tumor suppressor p53 is the most frequently mutated gene in human cancer and more than half of cancers contain p53 mutations. The development of novel and effective therapeutic strategies for p53 mutant cancer therapy is a big challenge and highly desirable. Ubiquitin-specific protease 7 (USP7), also known as HAUSP, is a deubiquitinating enzyme and proposed to stabilize the oncogenic E3 ubiquitin ligase MDM2 that promotes the proteosomal degradation of p53. Herein, we report the design and characterization of U7D-1 as the first selective USP7-degrading Proteolysis Targeting Chimera (PROTAC). U7D-1 showed selective and effective USP7 degradation, and maintained potent cell growth inhibition in p53 mutant cancer cells, with USP7 inhibitor showing no activity. These data clearly demonstrated the practicality and importance of PROTAC as a preliminary chemical tool for investigating USP7 protein functions and a promising method for potential p53 mutant cancer therapy.


Assuntos
Neoplasias , Proteína Supressora de Tumor p53 , Linhagem Celular Tumoral , Humanos , Neoplasias/metabolismo , Proteólise , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Ubiquitina Tiolesterase/química , Ubiquitina Tiolesterase/genética , Ubiquitina-Proteína Ligases/metabolismo , Peptidase 7 Específica de Ubiquitina/metabolismo
10.
Drug Metab Dispos ; 48(7): 544-552, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32350062

RESUMO

Several cytochrome P450 enzymes are known to be down-regulated by nitric oxide (NO). CYP2A6 is responsible for the metabolism of nicotine and several other xenobiotics, but its susceptibility to down-regulation by NO has not been reported. To address this question, we used Huh7 human hepatoma cell lines to express CYP2A6 with a C-terminal V5 tag (CYP2A6V5). NO donor treatment [dipropylenetriamine NONOate (DPTA)] down-regulated CYP2A6 protein to approximately 40% of control levels in 4 hours. An NO scavenging agent protected CYP2A6 from down-regulation by DPTA in a concentration-dependent manner, demonstrating that the down-regulation is NO-dependent. Experiments with the protein synthesis inhibitor cycloheximide showed that CYP2A6 protein down-regulation occurs posttranslationally. In the presence of proteasome inhibitors MG132 or bortezomib, NO-treated cells showed an accumulation of a high molecular mass signal, whereas autophagy inhibitors chloroquine and 3-methyladenine and the lysosomal and calpain inhibitor E64d had no effect. Immunoprecipitation of CYP2A6 followed by Western blotting with an antiubiquitin antibody showed that the high molecular mass species contain polyubiquitinated CYP2A6 protein. This suggests that NO led to the degradation of protein via the ubiquitin-proteasome pathway. The down-regulation by NO was blocked by the reversible CYP2A6 inhibitor pilocarpine but not by the suicide inhibitor methoxsalen, demonstrating that down-regulation requires NO access to the active site but does not require catalytic activity of the enzyme. These findings provide novel insights toward the regulation of CYP2A6 in a human cell line and can influence our understanding of CYP2A6-related drug metabolism. SIGNIFICANCE STATEMENT: This study demonstrates that the nicotine metabolizing enzyme CYP2A6 is down-regulated by nitric oxide, a molecule produced in large amounts in the context of inflammation and that is also inhaled from cigarette smoke. This occurs via ubiquitination and proteasomal degradation, and does not require catalytic activity of the enzyme. This work adds to the growing knowledge of the selective effect and mechanism of action of nitric oxide (NO) on cytochrome P450 enzymes and suggests a possible novel mode of interaction between nicotine and NO in cigarette smokers.


Assuntos
Citocromo P-450 CYP2A6/antagonistas & inibidores , Óxido Nítrico/farmacologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Linhagem Celular Tumoral , Fumar Cigarros/metabolismo , Citocromo P-450 CYP2A6/metabolismo , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/fisiologia , Humanos , Nicotina/metabolismo , Óxido Nítrico/metabolismo , Inibidores de Proteassoma/farmacologia , Inibidores da Síntese de Proteínas/farmacologia , Proteólise/efeitos dos fármacos , Ubiquitinação/efeitos dos fármacos , Ubiquitinação/fisiologia
11.
Acta Pharmacol Sin ; 37(7): 908-18, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27238210

RESUMO

AIM: Bufalin is one of the active components in the traditional Chinese medicine ChanSu that is used to treat arrhythmia, inflammation and cancer. BF211 is a bufalin derivative with stronger cytotoxic activity in cancer cells. The aim of this study was to identify the putative target proteins of BF211 and the signaling pathways in cancer cells. METHODS: A549 human lung cancer cells were treated with BF211. A SILAC-based proteomic analysis was used to detect the protein expression profiles of BF211-treated A549 cells. Cellular proteasome activities were examined using fluorogenic peptide substrates, and the binding affinities of BF211 to recombinant proteasome subunit proteins were evaluated using the Biacore assay. The expression levels of proteasome subunits were determined using RT-PCR and Western blotting, and the levels of the integral 26S proteasome were evaluated using native PAGE analysis. RESULTS: The proteomic analysis revealed that 1282 proteins were differentially expressed in BF211-treated A549 cells, and the putative target proteins of BF211 were associated with various cellular functions, including transcription, translation, mRNA splicing, ribosomal protein synthesis and proteasome function. In A549 cells, BF211 (5, 10, and 20 nmol/L) dose-dependently inhibited the enzymatic activities of proteasome. But BF211 displayed a moderate affinity in binding to proteasome ß1 subunit and no binding affinity to the ß2 and ß5 subunits. Moreover, BF211 (0.1, 1, and 10 nmol/L) did not inhibit the proteasome activities in the cell lysates. BF211 (5, 10, and 20 nmol/L) significantly decreased the expression level of proteasome ß1 subunit and the levels of integral 26S proteasome in A549 cells. Similarly, knockdown of the ß1 subunit with siRNA in A549 cells significantly decreased integral 26S proteasome and proteasome activity. CONCLUSION: BF211 inhibits proteasome activity in A549 cells by decreasing ß1 subunit expression and disrupting proteasome assembly.


Assuntos
Bufanolídeos/farmacologia , Neoplasias Pulmonares/enzimologia , Piperazinas/farmacologia , Complexo de Endopeptidases do Proteassoma/biossíntese , Complexo de Endopeptidases do Proteassoma/química , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Humanos , Neoplasias Pulmonares/patologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Subunidades Proteicas/química , Subunidades Proteicas/metabolismo , Proteômica , RNA Interferente Pequeno/farmacologia
12.
Nucleic Acids Res ; 40(Database issue): D252-60, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22146221

RESUMO

Minimotif Miner (MnM available at http://minimotifminer.org or http://mnm.engr.uconn.edu) is an online database for identifying new minimotifs in protein queries. Minimotifs are short contiguous peptide sequences that have a known function in at least one protein. Here we report the third release of the MnM database which has now grown 60-fold to approximately 300,000 minimotifs. Since short minimotifs are by their nature not very complex we also summarize a new set of false-positive filters and linear regression scoring that vastly enhance minimotif prediction accuracy on a test data set. This online database can be used to predict new functions in proteins and causes of disease.


Assuntos
Motivos de Aminoácidos , Bases de Dados de Proteínas , Sequência de Aminoácidos , Sequência Consenso , Modelos Biológicos , Mapas de Interação de Proteínas , Proteínas/genética , Análise de Sequência de Proteína
13.
Chem Biol Interact ; 392: 110926, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38431053

RESUMO

Metabolic reprogramming enables cancer cells to generate energy mainly through aerobic glycolysis, which is achieved by increasing the expression levels of glycolysis-related enzymes. Therefore, the development of drugs targeting aerobic glycolysis could be an effective strategy for cancer treatment. Icaritin (ICT) is an active ingredient from the Chinese herbal plant Epimedium with several biological activities, but its anti-cancer mechanism remains inconclusive. Using normal hepatocytes and hepatoma cells, our results showed that ICT suppressed cell proliferation and clonal formation and decreased glucose consumption and lactate production in liver cancer cells. In consistent, the mRNA and protein levels of several aerobic glycolysis-related genes were decreased upon ICT treatment. Furthermore, our results demonstrated that the expression levels of the aerobic glycolysis-related proteins were correlated with the p53 status in hepatoma cells. Using PFT-α or siRNA-p53, our results confirmed that ICT regulated aerobic glycolysis in a p53-dependent manner. In addition, ICT was found to stabilize p53 at the post-translational level which might be mediated by inhibiting MDM2 expression and affecting its interaction with p53. Finally, our results demonstrated that ICT increased the levels of ROS that activated p53 via the p38 MAPK pathway. In conclusion, ICT increased intracellular ROS levels in liver cancer cells, which promoted the stabilization and activation of p53, inhibiting the expression of aerobic glycolysis-related genes and glycolysis, and ultimately leading to the suppression of liver cancer development.


Assuntos
Carcinoma Hepatocelular , Flavonoides , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/metabolismo , Glicólise , Proliferação de Células , Linhagem Celular Tumoral
14.
Nat Aging ; 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38867059

RESUMO

Chronological aging correlates with epigenetic modifications at specific loci, calibrated to species lifespan. Such 'epigenetic clocks' appear conserved among mammals, but whether they are cell autonomous and restricted by maximal organismal lifespan remains unknown. We used a multilifetime murine model of repeat vaccination and memory T cell transplantation to test whether epigenetic aging tracks with cellular replication and if such clocks continue 'counting' beyond species lifespan. Here we found that memory T cell epigenetic clocks tick independently of host age and continue through four lifetimes. Instead of recording chronological time, T cells recorded proliferative experience through modification of cell cycle regulatory genes. Applying this epigenetic profile across a range of human T cell contexts, we found that naive T cells appeared 'young' regardless of organism age, while in pediatric patients, T cell acute lymphoblastic leukemia appeared to have epigenetically aged for up to 200 years. Thus, T cell epigenetic clocks measure replicative history and can continue to accumulate well-beyond organismal lifespan.

15.
Nat Commun ; 15(1): 1899, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38429276

RESUMO

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by multiple autoantibody types, some of which are produced by long-lived plasma cells (LLPC). Active SLE generates increased circulating antibody-secreting cells (ASC). Here, we examine the phenotypic, molecular, structural, and functional features of ASC in SLE. Relative to post-vaccination ASC in healthy controls, circulating blood ASC from patients with active SLE are enriched with newly generated mature CD19-CD138+ ASC, similar to bone marrow LLPC. ASC from patients with SLE displayed morphological features of premature maturation and a transcriptome epigenetically initiated in SLE B cells. ASC from patients with SLE exhibited elevated protein levels of CXCR4, CXCR3 and CD138, along with molecular programs that promote survival. Furthermore, they demonstrate autocrine production of APRIL and IL-10, which contributed to their prolonged in vitro survival. Our work provides insight into the mechanisms of generation, expansion, maturation and survival of SLE ASC.


Assuntos
Doenças Autoimunes , Lúpus Eritematoso Sistêmico , Humanos , Citocinas , Transcriptoma , Lúpus Eritematoso Sistêmico/genética , Células Produtoras de Anticorpos
16.
BMC Bioinformatics ; 14: 161, 2013 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-23679045

RESUMO

BACKGROUND: Motifs are significant patterns in DNA, RNA, and protein sequences, which play an important role in biological processes and functions, like identification of open reading frames, RNA transcription, protein binding, etc. Several versions of the motif search problem have been studied in the literature. One such version is called the Planted Motif Search (PMS)or (l, d)-motif Search. PMS is known to be NP complete. The time complexities of most of the planted motif search algorithms depend exponentially on the alphabet size. Recently a new version of the motif search problem has been introduced by Kuksa and Pavlovic. We call this version as the Motif Stems Search (MSS) problem. A motif stem is an l-mer (for some relevant value of l)with some wildcard characters and hence corresponds to a set of l-mers (without wildcards), some of which are (l, d)-motifs. Kuksa and Pavlovic have presented an efficient algorithm to find motif stems for inputs from large alphabets. Ideally, the number of stems output should be as small as possible since the stems form a superset of the motifs. RESULTS: In this paper we propose an efficient algorithm for MSS and evaluate it on both synthetic and real data. This evaluation reveals that our algorithm is much faster than Kuksa and Pavlovic's algorithm. CONCLUSIONS: Our MSS algorithm outperforms the algorithm of Kuksa and Pavlovic in terms of the run time as well as the number of stems output. Specifically, the stems output by our algorithm form a proper (and much smaller)subset of the stems output by Kuksa and Pavlovic's algorithm.


Assuntos
Algoritmos , Motivos de Aminoácidos , Motivos de Nucleotídeos , DNA/química , RNA/química , Análise de Sequência de DNA , Análise de Sequência de Proteína
17.
Front Med ; 17(3): 388-431, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37402952

RESUMO

Metformin has been used for the treatment of type II diabetes mellitus for decades due to its safety, low cost, and outstanding hypoglycemic effect clinically. The mechanisms underlying these benefits are complex and still not fully understood. Inhibition of mitochondrial respiratory-chain complex I is the most described downstream mechanism of metformin, leading to reduced ATP production and activation of AMP-activated protein kinase (AMPK). Meanwhile, many novel targets of metformin have been gradually discovered. In recent years, multiple pre-clinical and clinical studies are committed to extend the indications of metformin in addition to diabetes. Herein, we summarized the benefits of metformin in four types of diseases, including metabolic associated diseases, cancer, aging and age-related diseases, neurological disorders. We comprehensively discussed the pharmacokinetic properties and the mechanisms of action, treatment strategies, the clinical application, the potential risk of metformin in various diseases. This review provides a brief summary of the benefits and concerns of metformin, aiming to interest scientists to consider and explore the common and specific mechanisms and guiding for the further research. Although there have been countless studies of metformin, longitudinal research in each field is still much warranted.


Assuntos
Diabetes Mellitus Tipo 2 , Metformina , Humanos , Metformina/uso terapêutico , Metformina/farmacocinética , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Hipoglicemiantes/uso terapêutico , Hipoglicemiantes/farmacologia , Proteínas Quinases Ativadas por AMP/metabolismo , Envelhecimento
18.
Res Sq ; 2023 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-37461641

RESUMO

Systemic Lupus Erythematosus (SLE) is an autoimmune disease characterized by multiple autoantibodies, some of which are present in high titers in a sustained, B cell-independent fashion consistent with their generation from long-lived plasma cells (LLPC). Active SLE displays high numbers of circulating antibody-secreting cells (ASC). Understanding the mechanisms of generation and survival of SLE ASC would contribute important insight into disease pathogenesis and novel targeted therapies. We studied the properties of SLE ASC through a systematic analysis of their phenotypic, molecular, structural, and functional features. Our results indicate that in active SLE, relative to healthy post-immunization responses, blood ASC contain a much larger fraction of newly generated mature CD19- CD138+ ASC similar to bone marrow (BM) LLPC. SLE ASC were characterized by morphological and structural features of premature maturation. Additionally, SLE ASC express high levels of CXCR4 and CD138, and molecular programs consistent with increased longevity based on pro-survival and attenuated pro-apoptotic pathways. Notably, SLE ASC demonstrate autocrine production of APRIL and IL-10 and experience prolonged in vitro survival. Combined, our findings indicate that SLE ASC are endowed with enhanced peripheral maturation, survival and BM homing potential suggesting that these features likely underlie BM expansion of autoreactive PC.

19.
J Affect Disord ; 343: 77-85, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37741468

RESUMO

BACKGROUND: The COVID-19 pandemic has a heavy impact on the mental health of elderly surgical patients worldwide. In particular, the elderly patients faced considerable psychological stress due to various environmental and medical factors during the outbreak. This study aims to examine changes in mental health trends among non-cardiac surgical patients aged 65 and above in China during the COVID-19 pandemic. METHODS: This multi-center, convenient sampling, longitudinal observational study was conducted from April 1, 2020 to April 30, 2022. Primary outcome was the prevalence of postoperative depression. Secondary outcome was the prevalence of postoperative anxiety. Follow-up was conducted separately at 7 days and 30 days after surgery. Depression symptoms were assessed using the Patient Health Questionnaire 9 (PHQ-9) scale. Anxiety symptoms were assessed using Generalized Anxiety Disorder-7 (GAD-7) scale, with scores of ≥5 defining positive depression or anxiety symptoms. Multivariate logistic regression analysis was used to investigate risk factors of mental health status in more elderly patients undergoing non-cardiac surgery. RESULTS: A total of 4639 patients were included, of whom 2279 (46.0 %) were male, 752 (15.2 %) were over the age of 75, and 4346 (93.7 %) were married. The monthly prevalence trends demonstrated that compared to the outbreak period, a significant reduction in the prevalence of depression and anxiety symptoms in elderly patients who underwent surgery during the post-pandemic period. In post-pandemic period, a statistically significant decrease in the prevalence of all severity depression and anxiety patients was noted at the 7-day follow-up, but no significant decrease was observed for severe depression and anxiety in the 30-day follow-up. In COVID-19 low-risk area, a significant overall decrease in prevalence of mental health was observed during the post-pandemic period compared to the outbreak period, including 7-day depression, 7-day anxiety, 30-day depression, and 30-day anxiety (all with P < 0.001). Female and patients with ≥2 comorbidities appeared to be more susceptible to postoperative depression and anxiety during the pandemic. LIMITATION: The absence of data from the early days of the COVID-19 outbreak. CONCLUSIONS: This study analyzed the prevalence of depression and anxiety in elderly non-cardiac patients during and after the COVID-19 pandemic, focusing on dimensions such as severity, risk-areas, gender, and comorbidity. Our findings revealed a significant decrease in the prevalence of depression and anxiety in elderly surgery patients during the post-pandemic period.

20.
BMC Med Inform Decis Mak ; 12: 59, 2012 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-22741525

RESUMO

BACKGROUND: Recent large scale deployments of health information technology have created opportunities for the integration of patient medical records with disparate public health, human service, and educational databases to provide comprehensive information related to health and development. Data integration techniques, which identify records belonging to the same individual that reside in multiple data sets, are essential to these efforts. Several algorithms have been proposed in the literatures that are adept in integrating records from two different datasets. Our algorithms are aimed at integrating multiple (in particular more than two) datasets efficiently. METHODS: Hierarchical clustering based solutions are used to integrate multiple (in particular more than two) datasets. Edit distance is used as the basic distance calculation, while distance calculation of common input errors is also studied. Several techniques have been applied to improve the algorithms in terms of both time and space: 1) Partial Construction of the Dendrogram (PCD) that ignores the level above the threshold; 2) Ignoring the Dendrogram Structure (IDS); 3) Faster Computation of the Edit Distance (FCED) that predicts the distance with the threshold by upper bounds on edit distance; and 4) A pre-processing blocking phase that limits dynamic computation within each block. RESULTS: We have experimentally validated our algorithms on large simulated as well as real data. Accuracy and completeness are defined stringently to show the performance of our algorithms. In addition, we employ a four-category analysis. Comparison with FEBRL shows the robustness of our approach. CONCLUSIONS: In the experiments we conducted, the accuracy we observed exceeded 90% for the simulated data in most cases. 97.7% and 98.1% accuracy were achieved for the constant and proportional threshold, respectively, in a real dataset of 1,083,878 records.


Assuntos
Algoritmos , Bases de Dados Factuais , Registros Eletrônicos de Saúde , Análise por Conglomerados , Coleta de Dados , Mineração de Dados/métodos , Humanos
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