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1.
Immunity ; 55(11): 2044-2058.e5, 2022 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-36288724

RESUMO

Tumors are populated by antigen-presenting cells (APCs) including macrophage subsets with distinct origins and functions. Here, we examined how cancer impacts mononuclear phagocytic APCs in a murine model of breast cancer. Tumors induced the expansion of monocyte-derived tumor-associated macrophages (TAMs) and the activation of type 1 dendritic cells (DC1s), both of which expressed and required the transcription factor interferon regulatory factor-8 (IRF8). Although DC1s mediated cytotoxic T lymphocyte (CTL) priming in tumor-draining lymph nodes, TAMs promoted CTL exhaustion in the tumor, and IRF8 was required for TAMs' ability to present cancer cell antigens. TAM-specific IRF8 deletion prevented exhaustion of cancer-cell-reactive CTLs and suppressed tumor growth. Tumors from patients with immune-infiltrated renal cell carcinoma had abundant TAMs that expressed IRF8 and were enriched for an IRF8 gene expression signature. Furthermore, the TAM-IRF8 signature co-segregated with CTL exhaustion signatures across multiple cancer types. Thus, CTL exhaustion is promoted by TAMs via IRF8.


Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Humanos , Animais , Camundongos , Macrófagos Associados a Tumor , Fatores Reguladores de Interferon/genética , Fatores Reguladores de Interferon/metabolismo , Linfócitos T Citotóxicos , Células Dendríticas
2.
Cell ; 142(3): 456-67, 2010 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-20691904

RESUMO

RNA import into mammalian mitochondria is considered essential for replication, transcription, and translation of the mitochondrial genome but the pathway(s) and factors that control this import are poorly understood. Previously, we localized polynucleotide phosphorylase (PNPASE), a 3' --> 5' exoribonuclease and poly-A polymerase, in the mitochondrial intermembrane space, a location lacking resident RNAs. Here, we show a new role for PNPASE in regulating the import of nuclear-encoded RNAs into the mitochondrial matrix. PNPASE reduction impaired mitochondrial RNA processing and polycistronic transcripts accumulated. Augmented import of RNase P, 5S rRNA, and MRP RNAs depended on PNPASE expression and PNPASE-imported RNA interactions were identified. PNPASE RNA processing and import activities were separable and a mitochondrial RNA targeting signal was isolated that enabled RNA import in a PNPASE-dependent manner. Combined, these data strongly support an unanticipated role for PNPASE in mediating the translocation of RNAs into mitochondria.


Assuntos
Mitocôndrias/metabolismo , Polirribonucleotídeo Nucleotidiltransferase/metabolismo , RNA/metabolismo , Animais , Linhagem Celular , Técnicas de Inativação de Genes , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Polirribonucleotídeo Nucleotidiltransferase/genética , Processamento Pós-Transcricional do RNA , Ribonuclease P/metabolismo , Saccharomyces cerevisiae/metabolismo
3.
Am J Gastroenterol ; 119(4): 662-670, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-37795907

RESUMO

INTRODUCTION: Endoscopic eradication therapy (EET) is standard of care for T1a esophageal adenocarcinoma (EAC). However, data on outcomes in high-risk T1a EAC are limited. We assessed and compared outcomes after EET of low-risk and high-risk T1a EAC, including intraluminal EAC recurrence, extraesophageal metastases, and overall survival. METHODS: Patients who underwent EET for T1a EAC at 3 referral Barrett's esophagus endotherapy units between 1996 and 2022 were included. Patients with submucosal invasion, positive deep margins, or metastases at initial diagnosis were excluded. High-risk T1a EAC was defined as T1a EAC with poor differentiation and/or lymphovascular invasion, with low-risk disease being defined without these features. All pathology was systematically assessed by expert gastrointestinal pathologists. Baseline and follow-up endoscopy and pathology data were abstracted. Time-to-event analyses were performed to compare outcomes between groups. RESULTS: One hundred eighty-eight patients with T1a EAC were included (high risk, n = 45; low risk, n = 143) with a median age of 70 years, and 84% were men. Groups were comparable for age, sex, Barrett's esophagus length, lesion size, and EET technique. Rates of delayed extraesophageal metastases (11.1% vs 1.4%) were significantly higher in the high-risk group ( P = 0.02). There was no significant difference in the rates of intraluminal EAC recurrence ( P = 0.79) and overall survival ( P = 0.73) between the 2 groups. DISCUSSION: Patients with high-risk T1a EAC undergoing successful EET had a substantially higher rate of extraesophageal metastases compared with those with low-risk T1a EAC on long-term follow-up. These data should be factored into discussions with patients while selecting treatment approaches. Additional prospective data in this area are critical.


Assuntos
Adenocarcinoma , Esôfago de Barrett , Neoplasias Esofágicas , Masculino , Humanos , Idoso , Feminino , Esôfago de Barrett/cirurgia , Esôfago de Barrett/patologia , Estudos Prospectivos , Neoplasias Esofágicas/patologia , Adenocarcinoma/patologia , Endoscopia Gastrointestinal
4.
Immunity ; 43(3): 463-74, 2015 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-26320659

RESUMO

TREX1 is an endoplasmic reticulum (ER)-associated negative regulator of innate immunity. TREX1 mutations are associated with autoimmune and autoinflammatory diseases. Biallelic mutations abrogating DNase activity cause autoimmunity by allowing immunogenic self-DNA to accumulate, but it is unknown how dominant frameshift (fs) mutations that encode DNase-active but mislocalized proteins cause disease. We found that the TREX1 C terminus suppressed immune activation by interacting with the ER oligosaccharyltransferase (OST) complex and stabilizing its catalytic integrity. C-terminal truncation of TREX1 by fs mutations dysregulated the OST complex, leading to free glycan release from dolichol carriers, as well as immune activation and autoantibody production. A connection between OST dysregulation and immune disorders was demonstrated in Trex1(-/-) mice, TREX1-V235fs patient lymphoblasts, and TREX1-V235fs knock-in mice. Inhibiting OST with aclacinomycin corrects the glycan and immune defects associated with Trex1 deficiency or fs mutation. This function of the TREX1 C terminus suggests a potential therapeutic option for TREX1-fs mutant-associated diseases.


Assuntos
Citosol/enzimologia , Exodesoxirribonucleases/metabolismo , Hexosiltransferases/metabolismo , Proteínas de Membrana/metabolismo , Fosfoproteínas/metabolismo , Aclarubicina/análogos & derivados , Aclarubicina/farmacologia , Animais , Células Cultivadas , Embrião de Mamíferos/citologia , Exodesoxirribonucleases/antagonistas & inibidores , Exodesoxirribonucleases/genética , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Mutação da Fase de Leitura , Células HEK293 , Células HeLa , Hexosiltransferases/genética , Humanos , Imunidade Inata/genética , Immunoblotting , Proteínas de Membrana/genética , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Microscopia de Fluorescência , Fosfoproteínas/antagonistas & inibidores , Fosfoproteínas/genética , Polissacarídeos/metabolismo , Ligação Proteica , Interferência de RNA , Reação em Cadeia da Polimerase Via Transcriptase Reversa
5.
J Chem Phys ; 161(3)2024 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-39007388

RESUMO

We investigate the effects of solvents on the geometry, absorption spectrum, and first hyperpolarizability of six push-pull molecules, each containing a 4,5-dicyanoimidazole group as an electron acceptor and a N,N-dimethylamino group as an electron donor, with systematically extended π-conjugated systems. Geometry optimizations in dichloromethane, methanol, water, and formamide under normal thermodynamic conditions were performed using the average solvent electrostatic configuration-free energy gradient method, which employs a discrete solvent model. The conformational structure of molecules is moderately affected by the environment, with the π-conjugated system becoming more planar in protic solvents. Solvent effects on the first hyperpolarizability result in marked increases that are in line with the red shifts of the absorption spectrum. The hyperpolarizability of smaller molecules within the set may be significantly influenced by the effects of geometry relaxation in highly polar protic solvents. The results illustrate the role of hydrogen bonds in the structure and electronic properties of push-pull molecules in protic environments. For smaller molecules, hydrogen bonds significantly contribute to enhancing the hyperpolarizability, but the effect of these specific interactions becomes less significant with the length of the π-conjugated system.

6.
Trends Immunol ; 41(7): 601-613, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32446878

RESUMO

The mature naïve B cell repertoire consists of three well-defined populations: B1, B2 (follicular B, FOB), and marginal zone B (MZB) cells. FOB cells are the dominant mature B cell population in the secondary lymphoid organs and blood of both humans and mice. The driving forces behind mature B lineage selection have been linked to B cell receptor (BCR) signaling strength and environmental cues, but how these fate-determination factors are transcriptionally regulated remains poorly understood. We summarize emerging data on the role of transcription factors (TFs) - particularly the ETS and IRF families - in regulating MZB and FOB lineage selection. Indeed, genomic analyses have identified four major groups of target genes that are crucial for FOB differentiation, revealing previously unrecognized pathways that ultimately determine biological responses specific to this lineage.


Assuntos
Linfócitos B , Diferenciação Celular , Regulação da Expressão Gênica , Baço , Animais , Linfócitos B/citologia , Linfócitos B/imunologia , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Regulação da Expressão Gênica/imunologia , Humanos , Receptores de Antígenos de Linfócitos B/imunologia , Baço/citologia , Baço/imunologia
7.
Immunity ; 40(2): 187-98, 2014 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-24485804

RESUMO

Recent epidemiological studies have identified interferon regulatory factor 8 (IRF8) as a susceptibility factor for multiple sclerosis (MS). However, how IRF8 influences the neuroinflammatory disease has remained unknown. By studying the role of IRF8 in experimental autoimmune encephalomyelitis (EAE), a mouse model of MS, we found that Irf8(-/-) mice are resistant to EAE. Furthermore, expression of IRF8 in antigen-presenting cells (APCs, such as macrophages, dendritic cells, and microglia), but not in T cells, facilitated disease onset and progression through multiple pathways. IRF8 enhanced αvß8 integrin expression in APCs and activated TGF-ß signaling leading to T helper 17 (Th17) cell differentiation. IRF8 induced a cytokine milieu that favored growth and maintenance of Th1 and Th17 cells, by stimulating interleukin-12 (IL-12) and IL-23 production, but inhibiting IL-27 during EAE. Finally, IRF8 activated microglia and exacerbated neuroinflammation. Together, this work provides mechanistic bases by which IRF8 contributes to the pathogenesis of MS.


Assuntos
Inflamação/fisiopatologia , Integrinas/metabolismo , Fatores Reguladores de Interferon/metabolismo , Transdução de Sinais , Fator de Crescimento Transformador beta/metabolismo , Animais , Células Cultivadas , Células Dendríticas/imunologia , Encefalomielite Autoimune Experimental/fisiopatologia , Citometria de Fluxo , Fatores Reguladores de Interferon/genética , Macrófagos/imunologia , Camundongos , Camundongos Knockout , RNA Mensageiro/genética
8.
Gastrointest Endosc ; 98(5): 713-721, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37356631

RESUMO

BACKGROUND AND AIMS: Endoscopic eradication therapy (EET) is guideline endorsed for management of early-stage (T1) esophageal adenocarcinoma (EAC). Patients with baseline high-grade dysplasia (HGD) and EAC are at highest risk of recurrence after successful EET, but limited data exist on long-term (>5 year) recurrence outcomes. Our aim was to assess the incidence and predictors of long-term recurrence in a multicenter cohort of patients with T1 EAC treated with EET. METHODS: Patients with T1 EAC achieving successful endoscopic cancer eradication with a minimum of 5 years' clinical follow-up were included. The primary outcome was neoplastic recurrence, defined as dysplasia or EAC, and it was characterized as early (<2 years), intermediate (2-5 years), or late (>5 years). Predictors of recurrence were assessed by time to event analysis. RESULTS: A total of 84 T1 EAC patients (75 T1a, 9 T1b) with a median 9.1 years (range, 5.1-18.3 years) of follow-up were included. The overall incidence of neoplastic recurrence was 2.0 per 100 person-years of follow-up. Seven recurrences (3 dysplasia, 4 EAC) occurred after 5 years of EAC remission. Overall, 88% of recurrences were treated successfully endoscopically. EAC recurrence-related mortality occurred in 3 patients at a median of 5.2 years from EAC remission. Complete eradication of intestinal metaplasia was independently associated with reduced recurrence (hazard ratio, .13). CONCLUSIONS: Following successful EET of T1 EAC, neoplastic recurrence occurred after 5 years in 8.3% of cases. Careful long-term surveillance should be continued in this patient population. Complete eradication of intestinal metaplasia should be the therapeutic end point for EET.

9.
J Chem Phys ; 159(7)2023 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-37594066

RESUMO

We present a theoretical study on the structural and electronic properties of the p-dimethylamino-cinnamaldehyde (DMACA) merocyanine molecule in solvents of different polarities by combining the free energy gradient and the average solvent electrostatic configuration methods via an iterative procedure based on the sequential quantum mechanics/molecular mechanics hybrid methodology. Studying such a system in solution is a crucial step for understanding the solvent effects on its properties, which can have implications in fields such as optoelectronics and biophysics. We found that the DMACA molecule presents different geometries in nonpolar and polar solvents, changing from a polyene-like structure with a pyramidal dimethylamino group (in gas phase or nonpolar solvents) to a cyanine-like structure with a planar dimethylamino group in water due to the stabilizing effect of hydrogen bonds between DMACA and water. The molecular absorption spectrum showed a significant change, increasing solvent polarity with a large shift of the lower energy band, while the other two low lying bands did not shift significantly. The study accurately described the solvatochromic shift of the lowest-energy band and analyzed the structure of the excited states in terms of the one-electron transition density matrix, which showed that the dominant excited state (associated with the first lower energy band) is characterized by a local excitation on the benzene ring with charge transfer character to the carbon conjugated segment.

10.
Clin Gastroenterol Hepatol ; 20(2): e74-e88, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-33640480

RESUMO

BACKGROUND AND AIMS: We conducted a retrospective cohort study comparing the risk of serious infections between patients treated with tumor necrosis factor-a (TNFa) antagonists vs. vedolizumab in patients with inflammatory bowel diseases (IBD). METHODS: Using an administrative claims database, we identified patients with IBD who were new-users of either TNFa antagonists or vedolizumab between 2014-2018 and had insurance coverage for at least 1y before and after treatment initiation. We compared the risk of serious infections (infections requiring hospitalization) between patients treated with vedolizumab or TNFa antagonists using marginal structural Cox proportional hazard models adjusted for baseline disease characteristics, healthcare utilization, comorbidities, and time-varying use of corticosteroids, immunomodulators and opiates. RESULTS: We included 4881 patients treated with TNFa antagonists (age, 41 ± 15y, 60% with Crohn's disease [CD]) of whom 434 developed serious infections over 5786 person-year [PY] follow-up, and 1106 patients treated with vedolizumab (age, 44 ± 16y, 39% with CD) of whom 86 developed serious infections over 1040-PY follow-up. Vedolizumab was associated with 46% lower risk of serious infections as compared with TNFa antagonists in patients with ulcerative colitis (HR,0.54 [95% CI,0.35-0.83), but no significant differences were observed in patients with CD (HR,1.30 [0.80-2.11]). Vedolizumab was associated with lower risk of extra-intestinal serious infections in patients with UC, but higher risk of gastrointestinal serious infections in patients with CD. CONCLUSIONS: In an observational study of patients with IBD, vedolizumab was associated with lower risk of serious infections as compared with TNFa antagonists, in patients with UC, but not in patients with CD.


Assuntos
Colite Ulcerativa , Fármacos Gastrointestinais , Doenças Inflamatórias Intestinais , Adulto , Anticorpos Monoclonais Humanizados , Colite Ulcerativa/tratamento farmacológico , Fármacos Gastrointestinais/efeitos adversos , Fármacos Gastrointestinais/uso terapêutico , Humanos , Doenças Inflamatórias Intestinais/complicações , Doenças Inflamatórias Intestinais/tratamento farmacológico , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento , Inibidores do Fator de Necrose Tumoral , Fator de Necrose Tumoral alfa
11.
Phys Rev Lett ; 129(3): 034502, 2022 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-35905359

RESUMO

Processes leading to anomalous fluctuations in turbulent flows, referred to as intermittency, are still challenging. We consider cascade trajectories through scales as realizations of a stochastic Langevin process for which multiplicative noise is an intrinsic feature of the turbulent state. The trajectories are conditioned on their entropy exchange. Such selected trajectories concentrate around an optimal path, called instanton, which is the minimum of an effective action. The action is derived from the Langevin equation, estimated from measured data. In particular instantons with negative entropy pinpoint the trajectories responsible for the emergence of non-Gaussian statistics at small scales.

12.
Dig Dis Sci ; 67(6): 2510-2516, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-34085174

RESUMO

BACKGROUND AND AIMS: We conducted a retrospective cohort study comparing the risk of malignancy between patients treated with vedolizumab vs. tumor necrosis factor-α (TNFα) antagonists in patients with inflammatory bowel diseases (IBD). METHODS: Using an administrative claims database, we identified patients with IBD without prior malignancy who were new users of either vedolizumab or TNFα antagonists between 2014-2018, with no prior exposure to either biologic or in preceding 1 y and had insurance coverage for at least 1 y after treatment initiation. We estimated incidence rate of malignancy (solid organ, hematological or skin cancers) in patients treated with vedolizumab and TNFα antagonists, and compared risk using Cox proportional hazard analysis. RESULTS: We included 4807 patients treated with TNFα antagonists (age, 41 ± 15 y, 60% with Crohn's disease [CD]) of whom 65 developed malignancy over 7214 person-year [PY] follow-up (incidence rate [IR], 9.0 per 1000-PY), and 759 patients treated with vedolizumab (age, 46 ± 16y, 42% CD) of whom 11 developed malignancy over 950-PY follow-up (IR, 11.6). No difference was observed in the incidence of malignancy between vedolizumab versus TNFα antagonists (incidence rate ratio, 1.28; 95% CI, 0.61-2.45). After adjusting for age, sex, race, comorbidity burden, disease phenotype and concomitant use of immunomodulators, no difference was observed in time to incident malignancy between vedolizumab versus TNFα antagonists (HR, 1.15; 95% CI, 0.61-2.19). Similar results were observed on stratified analysis by age and concomitant immunomodulators, and after excluding non-melanoma skin cancers. CONCLUSIONS: In an observational study of patients with IBD, no differences were observed in the risk of incident malignancy in patients treated with vedolizumab versus TNFα antagonists.


Assuntos
Anticorpos Monoclonais Humanizados , Colite Ulcerativa , Doença de Crohn , Neoplasias , Inibidores do Fator de Necrose Tumoral , Anticorpos Monoclonais Humanizados/efeitos adversos , Colite Ulcerativa/tratamento farmacológico , Doença de Crohn/tratamento farmacológico , Fármacos Gastrointestinais/efeitos adversos , Humanos , Fatores Imunológicos/efeitos adversos , Neoplasias/induzido quimicamente , Estudos Retrospectivos , Inibidores do Fator de Necrose Tumoral/efeitos adversos
13.
Am J Emerg Med ; 55: 51-56, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35279577

RESUMO

BACKGROUND: Patients with mental illness have been shown to receive lower quality of care and experience worse cardiovascular (CV) outcomes compared to those without mental illness. This present study examined mental health-related disparities in CV outcomes after an Emergency Department (ED) visit for chest pain. METHODS: This retrospective cohort included adult Medicaid beneficiaries in Washington state discharged from the ED with a primary diagnosis of unspecified chest pain in 2010-2017. Outcomes for patients with any mental illness (any mental health diagnosis or mental-health specific service use within 1 year of an index ED visit) and serious mental illness (at least two claims (on different dates of service) within 1 year of an index ED visit with a diagnosis of schizophrenia, other psychotic disorder, or major mood disorder) were compared to those of patients without mental illness. Our outcomes of interest were the incidence of major adverse cardiac events (MACE) within 30 days and 6 months of discharge of their ED visit, defined as a composite of death, acute myocardial infarction (AMI), CV rehospitalization, or revascularization. Secondary outcomes included cardiovascular diagnostic testing (diagnostic angiography, stress testing, echocardiography, and coronary computed tomography (CT) angiography) rates within 30 days of ED discharge. Only treat-and-release visits were included for outcomes assessment. Hierarchical logistic random effects regression models assessed the association between mental illness and the outcomes of interest, controlling for age, gender, race, ethnicity, Elixhauser comorbidities, and health care use in the past year, as well as fixed year effects. RESULTS: There were 98,812 treat-and-release ED visits in our dataset. At 30 days, enrollees with any mental illness had no differences in rates of MACE (AOR 0.96; 95% CI, 0.72-1.27) or any of the individual components. At 6 months, enrollees with any mental illness (AOR 1.86; 95% CI, 1.11-3.09) and serious mental illness (AOR 2.60; 95% CI 1.33-5.13) were significantly more likely to be hospitalized for a CV condition compared to those without mental illness. Individuals with any mental illness had higher rates of testing at 30 days (AOR 1.16; 95% CI 1.07-1.27). CONCLUSION: Patients with mental illness have similar rates of MACE, but higher rates of certain CV outcomes, such as CV hospitalization and diagnostic testing, after an ED visit for chest pain.


Assuntos
Dor no Peito , Transtornos Mentais , Adulto , Dor no Peito/diagnóstico , Dor no Peito/epidemiologia , Dor no Peito/etiologia , Angiografia Coronária/métodos , Serviço Hospitalar de Emergência , Humanos , Transtornos Mentais/diagnóstico , Transtornos Mentais/epidemiologia , Estudos Retrospectivos , Estados Unidos/epidemiologia
14.
Proc Natl Acad Sci U S A ; 116(19): 9511-9520, 2019 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-31000603

RESUMO

The IRF and Ets families of transcription factors regulate the expression of a range of genes involved in immune cell development and function. However, the understanding of the molecular mechanisms of each family member has been limited due to their redundancy and broad effects on multiple lineages of cells. Here, we report that double deletion of floxed Irf8 and Spi1 (encoding PU.1) by Mb1-Cre (designated DKO mice) in the B cell lineage resulted in severe defects in the development of follicular and germinal center (GC) B cells. Class-switch recombination and antibody affinity maturation were also compromised in DKO mice. RNA-seq (sequencing) and ChIP-seq analyses revealed distinct IRF8 and PU.1 target genes in follicular and activated B cells. DKO B cells had diminished expression of target genes vital for maintaining follicular B cell identity and GC development. Moreover, our findings reveal that expression of B-cell lymphoma protein 6 (BCL6), which is critical for development of germinal center B cells, is dependent on IRF8 and PU.1 in vivo, providing a mechanism for the critical role for IRF8 and PU.1 in the development of GC B cells.


Assuntos
Linfócitos B/imunologia , Centro Germinativo/imunologia , Fatores Reguladores de Interferon/imunologia , Proteínas Proto-Oncogênicas c-bcl-6/imunologia , Proteínas Proto-Oncogênicas/imunologia , Transativadores/imunologia , Animais , Linfócitos B/citologia , Centro Germinativo/citologia , Switching de Imunoglobulina/imunologia , Fatores Reguladores de Interferon/genética , Ativação Linfocitária/genética , Camundongos , Camundongos Knockout , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas c-bcl-6/genética , Transativadores/genética
15.
Mol Biol Evol ; 37(8): 2211-2227, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32181804

RESUMO

Understanding how organisms adapt to extreme environments is fundamental and can provide insightful case studies for both evolutionary biology and climate-change biology. Here, we take advantage of the vast diversity of lifestyles in ants to identify genomic signatures of adaptation to extreme habitats such as high altitude. We hypothesized two parallel patterns would occur in a genome adapting to an extreme habitat: 1) strong positive selection on genes related to adaptation and 2) a relaxation of previous purifying selection. We tested this hypothesis by sequencing the high-elevation specialist Tetramorium alpestre and four other phylogenetically related species. In support of our hypothesis, we recorded a strong shift of selective forces in T. alpestre, in particular a stronger magnitude of diversifying and relaxed selection when compared with all other ants. We further disentangled candidate molecular adaptations in both gene expression and protein-coding sequence that were identified by our genome-wide analyses. In particular, we demonstrate that T. alpestre has 1) a higher level of expression for stv and other heat-shock proteins in chill-shock tests and 2) enzymatic enhancement of Hex-T1, a rate-limiting regulatory enzyme that controls the entry of glucose into the glycolytic pathway. Together, our analyses highlight the adaptive molecular changes that support colonization of high-altitude environments.


Assuntos
Aclimatação/genética , Formigas/genética , Evolução Biológica , Genoma de Inseto , Seleção Genética , Animais , Clima Frio , Proteínas de Choque Térmico/genética
16.
Clin Gastroenterol Hepatol ; 19(6): 1160-1169.e2, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-32434069

RESUMO

BACKGROUND & AIMS: Radiofrequency ablation (RFA) is the most common treatment for flat Barrett's esophagus (BE), but reasons for varying outcomes are poorly understood. A recently developed contrast-enhancement algorithm allows reliable measurement of Barrett's epithelial thickness (BET) from volumetric laser endomicroscopy (VLE) images and correlation with response to RFA. Using this algorithm, we investigated whether patients with thicker Barrett's mucosa are less likely to respond to RFA. In the future, this algorithm may guide choice of RFA dosing or endoscopic resection. METHODS: We performed a retrospective analysis on all patients with BE who received a baseline VLE scan between May 2015 and October 2016, followed by RFA and 1 follow-up exam, from 14 institutions participating in the United States VLE registry. We measured BET on equidistant locations by estimating the distance between the esophageal surface and the superficial edge of the deepest lamina propria. The primary outcome variable was the percentage reduction in Prague length; secondary outcome variables were complete remission of intestinal metaplasia (CRIM) and presence of strictures after 12 months. RESULTS: Images from 61 patients were included in our final analysis. Mean BET per patient ranged from 224 µm to 705 µm. A 100 µm thicker mean BET per patient resulted in a 12% lower response to treatment, measured by a reduction of Prague length (P = .03), after adjustment for confounders. We found an association between mean BET and CRIM, but not with stricture formation. CONCLUSIONS: Based on measurements on contrast-enhanced VLE images, we found that BET correlates with response to RFA. For clinical implementation, larger studies with a standardized follow-up and development of computer-aided image analysis systems are needed.


Assuntos
Esôfago de Barrett , Ablação por Cateter , Neoplasias Esofágicas , Ablação por Radiofrequência , Esôfago de Barrett/cirurgia , Neoplasias Esofágicas/cirurgia , Esofagoscopia , Humanos , Lasers , Estudos Retrospectivos , Resultado do Tratamento
17.
Mol Phylogenet Evol ; 155: 107016, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33242582

RESUMO

Social parasitism, i.e. the parasitic dependence of a social species on another free-living social species, is one of the most intriguing phenomena in social insects. It has evolved to various levels, the most extreme form being inquiline social parasites which have lost the worker caste, and produce only male and female sexual offspring that are reared by the host worker force. The inquiline syndrome has been reported in 4 species within the ant genus Plagiolepis, in Europe. Whether inquiline social parasitism evolved once or multiple times within the genus remains however unknown. To address this question, we generated data for 5 inquiline social parasites - 3 species previously described and 2 unidentified species - and their free-living hosts from Europe, and we inferred their phylogenetic relationships. We tested Emery's rule, which predicts that inquiline social parasites and their hosts are close relatives. Our results show that inquiline parasitism evolved independently at least 5 times in the genus. Furthermore, we found that all inquilines were associated with one of the descendants of their most related free-living species, suggesting sympatric speciation is the main process leading to the emergence of the parasitic species, consistent with the stricter version of Emery's rule.


Assuntos
Formigas/fisiologia , Evolução Biológica , Interações Hospedeiro-Parasita , Parasitos/fisiologia , Animais , Feminino , Masculino , Modelos Teóricos , Filogenia , Simbiose
18.
Blood ; 133(17): 1803-1813, 2019 04 25.
Artigo em Inglês | MEDLINE | ID: mdl-30796024

RESUMO

Dendritic cells (DCs), which are vital for immune responses, are derived from bone marrow hematopoietic stem cells via common DC progenitors (CDPs). DC lineage fate decisions occurring at stages much earlier than CDPs have recently been recognized, yet the mechanism remains elusive. By single-cell RNA-sequencing, in vivo cell transfer experiments, and an assay for transposase-accessible chromatin sequencing using wild-type, IRF8-GFP chimera knock-in or IRF8-knockout mice, we demonstrate that IRF8 regulates chromatin at the lymphoid-primed multipotent progenitor (LMPP) stage to induce early commitment toward DCs. A low but significant expression of IRF8, a transcription factor essential for DC and monocyte development, was initiated in a subpopulation within LMPPs. These IRF8+ LMPPs were derived from IRF8- LMPPs and predominantly produced DCs, especially classical DC1s, potentially via known progenitors, such as monocyte-DC progenitors, CDPs, and preclassical DCs. IRF8+ LMPPs did not generate significant numbers of monocytes, neutrophils, or lymphocytes. Although IRF8- and IRF8+ LMPPs displayed very similar global gene expression patterns, the chromatin of enhancers near DC lineage genes was more accessible in IRF8+ LMPPs than in IRF8- LMPPs, an epigenetic change dependent on IRF8. The majority of the genes epigenetically primed by IRF8 were still transcriptionally inactive at the LMPP stage, but were highly expressed in the downstream DC lineage populations such as CDPs. Therefore, early expression of the key transcription factor IRF8 changes chromatin states in otherwise multipotent progenitors, biasing their fate decision toward DCs.


Assuntos
Linhagem da Célula/genética , Células Dendríticas/citologia , Epigênese Genética , Regulação da Expressão Gênica , Fatores Reguladores de Interferon/fisiologia , Células-Tronco Multipotentes/citologia , Células Precursoras de Linfócitos B/citologia , Animais , Células Cultivadas , Células Dendríticas/metabolismo , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Células-Tronco Multipotentes/metabolismo , Células Precursoras de Linfócitos B/metabolismo
19.
Gastrointest Endosc ; 93(6): 1276-1282, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33309653

RESUMO

BACKGROUND AND AIMS: EMR and endoscopic submucosal dissection (ESD) are treatment modalities for Barrett's esophagus involving high-grade dysplasia or early cancer. Injectional corticosteroid therapy decreases the risk of procedure-related esophageal stricture (ES) formation. Our aim was to assess the efficacy of topical budesonide on the rate of ES formation after EMR or ESD. METHODS: Patients included prospectively from 3 tertiary endoscopy centers received 3 mg budesonide orally twice a day for 8 weeks after esophageal EMR or ESD of 50% or more of the esophageal circumference between January 1, 2014 and June 30, 2018. These patients were matched (1:3 ratio) retrospectively with a consecutive patient cohort who underwent EMR or ESD of 50% or more of the esophageal circumference without concomitant corticosteroid therapy. The primary endpoint was the presence of ES at the 12-week follow-up. RESULTS: Twenty-five patients (budesonide) were matched with 75 patients (no budesonide). Most underwent EMR for Barrett's esophagus with biopsy-proven high-grade dysplasia or suspected T1a cancer. Although most baseline characteristics did not differ significantly, patients in the budesonide cohort tended to have a higher proportion of circumferential EMR. The proportion of patients with ES was not significantly lower in the budesonide cohort (16% vs 28%). On logistic regression analysis, budesonide remained associated with a lower incidence of ES (P = .023); however, when controlling for baseline characteristics with a propensity score weighted logistic regression model, there was no significant effect on ES formation (P = .176). CONCLUSIONS: Topical budesonide might be associated with a reduction of ES after EMR or ESD; however, further studies are needed to verify our results.


Assuntos
Adenocarcinoma , Esôfago de Barrett , Ressecção Endoscópica de Mucosa , Neoplasias Esofágicas , Estenose Esofágica , Budesonida/uso terapêutico , Ressecção Endoscópica de Mucosa/efeitos adversos , Estenose Esofágica/etiologia , Estenose Esofágica/prevenção & controle , Humanos , Estudos Retrospectivos
20.
Gastrointest Endosc ; 94(3): 498-505, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33857451

RESUMO

BACKGROUND AND AIMS: We previously identified a 5 methylated DNA marker (MDM) panel for the detection of nonendoscopic Barrett's esophagus (BE). In this study, we aimed to recalibrate the performance of the 5 MDM panel using a simplified assay in a training cohort, validate the panel in an independent test cohort, and explore the accuracy of an MDM panel with only 3 markers. METHODS: Participants were recruited from 3 medical centers. The sponge on a string device (EsophaCap; CapNostics, Concord, NC, USA) was swallowed and withdrawn, followed by endoscopy, in BE cases and control subjects. A 5 MDM panel was blindly assayed using a simplified assay. Random forest modeling analysis was performed, in silico cross-validated in the training set, and then locked down, before test set analysis. RESULTS: The training set had 199 patients: 110 BE cases and 89 control subjects, and the test set had 89 patients: 60 BE cases and 29 control subjects. Sensitivity of the 5 MDM panel for BE diagnosis was 93% at 90% specificity in the training set and 93% at 93% specificity in the test set. Areas under the receiver operating characteristic curves were .96 and .97 in the training and test sets, respectively. Model accuracy was not influenced by age, sex, or smoking history. Multiple 3 MDM panels achieved similar accuracy. CONCLUSIONS: A 5 MDM panel for BE is highly accurate in training and test sets in a blinded multisite case-control analysis using a simplified assay. This panel may be reduced to only 3 MDMs in the future. (Clinical trial registration number: NCT02560623.).


Assuntos
Esôfago de Barrett , Neoplasias Esofágicas , Esôfago de Barrett/diagnóstico , Estudos de Casos e Controles , Estudos de Coortes , Marcadores Genéticos , Humanos , Curva ROC
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