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The vertebrate adaptive immune system modifies the genome of individual B cells to encode antibodies that bind particular antigens1. In most mammals, antibodies are composed of heavy and light chains that are generated sequentially by recombination of V, D (for heavy chains), J and C gene segments. Each chain contains three complementarity-determining regions (CDR1-CDR3), which contribute to antigen specificity. Certain heavy and light chains are preferred for particular antigens2-22. Here we consider pairs of B cells that share the same heavy chain V gene and CDRH3 amino acid sequence and were isolated from different donors, also known as public clonotypes23,24. We show that for naive antibodies (those not yet adapted to antigens), the probability that they use the same light chain V gene is around 10%, whereas for memory (functional) antibodies, it is around 80%, even if only one cell per clonotype is used. This property of functional antibodies is a phenomenon that we call light chain coherence. We also observe this phenomenon when similar heavy chains recur within a donor. Thus, although naive antibodies seem to recur by chance, the recurrence of functional antibodies reveals surprising constraint and determinism in the processes of V(D)J recombination and immune selection. For most functional antibodies, the heavy chain determines the light chain.
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Anticorpos , Seleção Clonal Mediada por Antígeno , Cadeias Pesadas de Imunoglobulinas , Cadeias Leves de Imunoglobulina , Animais , Sequência de Aminoácidos , Anticorpos/química , Anticorpos/genética , Anticorpos/imunologia , Antígenos/química , Antígenos/imunologia , Linfócitos B/citologia , Linfócitos B/imunologia , Linfócitos B/metabolismo , Regiões Determinantes de Complementaridade/química , Regiões Determinantes de Complementaridade/imunologia , Cadeias Pesadas de Imunoglobulinas/química , Cadeias Pesadas de Imunoglobulinas/genética , Cadeias Pesadas de Imunoglobulinas/imunologia , Mamíferos , Cadeias Leves de Imunoglobulina/química , Cadeias Leves de Imunoglobulina/genética , Cadeias Leves de Imunoglobulina/imunologia , Memória Imunológica , Recombinação V(D)J , Seleção Clonal Mediada por Antígeno/genética , Seleção Clonal Mediada por Antígeno/imunologiaRESUMO
Antisense oligonucleotides (ASOs) are a novel therapeutic strategy that targets a specific gene and suppresses its expression. The cryopyrin-associated periodic syndromes (CAPS) are a spectrum of autoinflammatory diseases characterized by systemic and tissue inflammation that is caused by heterozygous gain-of-function mutations in the nucleotide-binding and oligomerization domain-like receptor (NLR) family pyrin domain containing 3 (NLRP3) gene. The aim of this study was to investigate the efficacy of an Nlrp3-specific ASO treatment in CAPS. An Nlrp3-specific ASO was designed and tested in murine cell lines and bone marrow-derived macrophages (BMDMs) from wild-type and CAPS mouse models. Nlrp3 knock-in mice were treated in vivo with Nlrp3-specific ASO, survival was monitored, and expression of organ-specific Nlrp3 and IL-1ß was measured. Nlrp3-specific ASO treatment of murine cell lines and BMDMs showed a significant downregulation of Nlrp3 and mature IL-1ß protein expression. Ex vivo treatment of Nlrp3 mutant mouse-derived BMDMs with Nlrp3-specific ASO demonstrated significantly reduced IL-1ß release. In vivo, Nlrp3-specific ASO treatment of Nlrp3 mutant mice prolonged survival, reduced systemic inflammation, and decreased tissue-specific expression of Nlrp3 and mature IL-1ß protein. The results of this study demonstrate that Nlrp3-specific ASO treatment downregulates Nlrp3 expression and IL-1ß release in CAPS models, suggesting ASO therapy as a potential treatment of CAPS and other NLRP3-mediated diseases.
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Síndromes Periódicas Associadas à Criopirina , Proteína 3 que Contém Domínio de Pirina da Família NLR , Camundongos , Animais , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Inflamassomos/metabolismo , Síndromes Periódicas Associadas à Criopirina/genética , Inflamação , Proteínas de Transporte/genética , Interleucina-1beta/metabolismoRESUMO
Dendritic cells (DC) are key sentinels of the host immune response with an important role in linking innate and adaptive immunity and maintaining tolerance. There is increasing recognition that DC are critical determinants of initiating and sustaining effective T-cell-mediated anti-tumor immune responses. Recent progress in immuno-oncology has led to the evolving insight that the presence and function of DC within the tumor microenvironment (TME) may dictate efficacy of cancer immunotherapies as well as conventional cancer therapies, including immune checkpoint blockade, radiotherapy and chemotherapy. As such, improved understanding of dendritic cell immunobiology specifically focusing on their role in T-cell priming, migration into tissues and TME, and the coordinated in vivo responses of functionally specialized DC subsets will facilitate a better mechanistic understanding of how tumor-immune surveillance can be leveraged to improve patient outcomes and to develop novel DC-targeted therapeutic approaches.
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Células Dendríticas , Neoplasias , Imunidade Adaptativa , Humanos , Imunoterapia , Neoplasias/terapia , Microambiente TumoralRESUMO
SETD2 (SET-domain containing protein 2) is a histone methyltransferase (HMT) of the SET family responsible for the trimethylation of K36 of histone H3, thus producing the epigenetic mark H3K36me3. Recent studies have shown that certain SET family HMTs, such as SMYD2, SMYD3 or SETDB1 can also methylate protein kinases and therefore be involved in signaling pathways. Here we provide structural and enzymatic evidence showing that SETD2 methylates the protein tyrosine kinase ACK1 in vitro. ACK1 is recognized as a major integrator of signaling from various receptor tyrosine kinases. Using ACK1 peptides and recombinant proteins, we show that SETD2 methylates the K514 residue of ACK1 generating K514 mono, di or tri-methylation. Interestingly, K514 is found in a "H3K36-like" motif of ACK1 which is known to be post-translationally modified and to be involved in protein-protein interaction. The crystal structure of SETD2 catalytic domain in complex with an ACK1 peptide further provides the structural basis for the methylation of ACK1 K514 by SETD2. Our work therefore strongly suggests that ACK1 could be a novel non-histone substrate of SETD2 and further supports that SET HMTs, such as SETD2, could be involved in both epigenetic regulations and cell signaling.
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Histonas , Proteínas Tirosina Quinases , Proteínas Tirosina Quinases/metabolismo , Histonas/metabolismo , Metilação , Histona-Lisina N-Metiltransferase/genética , Processamento de Proteína Pós-TraducionalRESUMO
BACKGROUND AND AIMS: Nucleotide-binding oligomerization domain-like receptor-family pyrin domain-containing 3 (NLRP3) inflammasome activation has been shown to result in liver fibrosis. Mechanisms and downstream signaling remain incompletely understood. Here, we studied the role of IL-18 in hepatic stellate cells (HSCs), and its impact on liver fibrosis. APPROACH AND RESULTS: We observed significantly increased serum levels of IL-18 (128.4 pg/ml vs. 74.9 pg/ml) and IL-18 binding protein (BP; 46.50 ng/ml vs. 15.35 ng/ml) in patients with liver cirrhosis compared with healthy controls. Single cell RNA sequencing data showed that an immunoregulatory subset of murine HSCs highly expresses Il18 and Il18r1 . Treatment of cultured primary murine HSC with recombinant mouse IL-18 accelerated their transdifferentiation into myofibroblasts. In vivo , IL-18 receptor-deficient mice had reduced liver fibrosis in a model of fibrosis induced by HSC-specific NLRP3 overactivation. Whole liver RNA sequencing analysis from a murine model of severe NASH-induced fibrosis by feeding a choline-deficient, L-amino acid-defined, high fat diet showed that genes related to IL-18 and its downstream signaling were significantly upregulated, and Il18-/- mice receiving this diet for 10 weeks showed protection from fibrotic changes with decreased number of alpha smooth muscle actin-positive cells and collagen deposition. HSC activation triggered by NLRP3 inflammasome activation was abrogated when IL-18 signaling was blocked by its naturally occurring antagonist IL-18BP. Accordingly, we observed that the severe inflammatory phenotype associated with myeloid cell-specific NLRP3 gain-of-function was rescued by IL-18BP. CONCLUSIONS: Our study highlights the role of IL-18 in the development of liver fibrosis by its direct effect on HSC activation identifying IL-18 as a target to treat liver fibrosis.
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Células Estreladas do Fígado , Inflamassomos , Camundongos , Animais , Inflamassomos/metabolismo , Células Estreladas do Fígado/metabolismo , Interleucina-18 , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Cirrose Hepática/patologia , Fibrose , Proteínas de Transporte/metabolismo , Fígado/patologiaRESUMO
Orosomucoid, or alpha-1 acid glycoprotein (AGP), is a major acute-phase protein expressed in response to systemic injury and inflammation. AGP has been described as an inhibitor of neutrophil migration on sepsis, particularly its immunomodulation effects. AGP's biological functions in coronavirus disease 2019 (COVID-19) are not understood. We sought to investigate the role of AGP in severe COVID-19 infection patients and neutrophils infected with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Epidemiological data, AGP levels, and other laboratory parameters were measured in blood samples from 56 subjects hospitalized in the ICU with SARS-CoV-2 infection. To evaluate the role of AGP in NETosis in neutrophils, blood samples from health patients were collected, and neutrophils were separated and infected with SARS-CoV-2. Those neutrophils were treated with AGP or vehicle, and NETosis was analyzed by flow cytometry. AGP was upregulated in severe COVID-19 patients (p<0.05). AGP level was positively correlated with IL-6 and C-reactive protein (respectively, p=0.005, p=0.002) and negatively correlated with lactate (p=0.004). AGP treatment downregulated early and late NETosis (respectively, 35.7% and 43.5%) in neutrophils infected with SARS-CoV-2 and up-regulated IL-6 supernatant culture expression (p<0.0001). Our data showed increased AGP in COVID-19 infection and contributed to NETosis regulation and increased IL-6 production, possibly related to the Cytokine storm in COVID-19.
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COVID-19 , Humanos , COVID-19/metabolismo , Neutrófilos/metabolismo , Orosomucoide/metabolismo , Orosomucoide/farmacologia , SARS-CoV-2 , Interleucina-6/metabolismo , Receptores Proteína Tirosina Quinases/metabolismo , Imunoproteínas/metabolismoRESUMO
PURPOSE/AIM: Cartilage injury and subsequent osteoarthritis (OA) are debilitating conditions affecting millions worldwide. As there are no cures for these ailments, novel therapies are needed to suppress disease pathogenesis. Given that joint injuries are known to produce damage-associated molecular patterns (DAMPs), our central premise is that the Toll-like receptor 4 (TLR4) pathway is a principal driver in the early response to cartilage damage and subsequent pathology. We postulate that TLR4 activation is initiated/perpetuated by DAMPs released following joint damage. Thus, antagonism of the TLR4 pathway immediately after injury may suppress the development of joint surface defects. MATERIALS AND METHODS: Two groups were utilized: (1) 8-week-old, male C57BL6 mice treated systemically with a known TLR4 antagonist and (2) mice injected with vehicle control. A full-depth cartilage lesion on the midline of the patellofemoral groove was created in the right knee of each mouse. The left knee was used as a sham surgery control. Gait changes were evaluated over 4 weeks using a quantitative gait analysis system. At harvest, knee joints were processed for pathologic assessment, Nanostring® transcript expression, and immunohistochemistry (IHC). RESULTS: Short-term treatment with a TLR4 antagonist at 14-days significantly improved relevant gait parameters; improved cartilage metrics and modified Mankin scores were also seen. Additionally, mRNA expression and IHC showed reduced expression of inflammatory mediators in animals treated with the TLR4 antagonist. CONCLUSIONS: Collectively, this work demonstrates that systemic treatment with a TLR4 antagonist is protective to further cartilage damage 14-days post-injury in a murine model of induced disease.
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Doenças das Cartilagens , Cartilagem Articular , Osteoartrite do Joelho , Osteoartrite , Camundongos , Masculino , Animais , Receptor 4 Toll-Like , Modelos Animais de Doenças , Camundongos Endogâmicos C57BL , Osteoartrite/patologia , Cartilagem/patologia , Doenças das Cartilagens/patologia , Cartilagem Articular/patologia , Osteoartrite do Joelho/patologiaRESUMO
Sterile inflammation is a central element in liver diseases. The immune response following injurious stimuli involves hepatic infiltration of neutrophils and monocytes. Neutrophils are major effectors of liver inflammation, rapidly recruited to sites of inflammation, and can augment the recruitment of other leukocytes. The NLRP3 inflammasome has been increasingly implicated in severe liver inflammation, fibrosis, and cell death. In this study, the role of NLRP3 activation in neutrophils during liver inflammation and fibrosis was investigated. Mouse models with neutrophil-specific expression of mutant NLRP3 were developed. Mutant mice develop severe liver inflammation and lethal autoinflammation phenocopying mice with a systemic expression of mutant NLRP3. NLRP3 activation in neutrophils leads to a pro-inflammatory cytokine and chemokine profile in the liver, infiltration by neutrophils and macrophages, and an increase in cell death. Furthermore, mutant mice develop liver fibrosis associated with increased expression of pro-fibrogenic genes. Taken together, the present work demonstrates how neutrophils, driven by the NLRP3 inflammasome, coordinate other inflammatory myeloid cells in the liver, and propagate the inflammatory response in the context of inflammation-driven fibrosis.
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Hepatite , Inflamassomos , Camundongos , Animais , Inflamassomos/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Neutrófilos/metabolismo , Hepatite/genética , Fibrose , Inflamação/metabolismo , Interleucina-1beta/metabolismoRESUMO
OBJECTIVES: The primary objective of this study is to further explore associations between social influencers of health and markers of disease severity at the time of presentation of patients with pediatric metabolic dysfunction-associated steatotic liver disease (MASLD) using neighborhood-level Area Deprivation Index (ADI) scores. METHODS: A retrospective cross-sectional study was conducted among 344 pediatric MASLD patients. Each patient received an ADI score based on their 9-digit zip code. Groups were defined as low (≤5) and high (6≥) ADI. Associations between ADI and symptomatology and laboratory values at presentation, as well as initial liver biopsy pathology were tested via analyses of covariance, χ2 testing, and logistic regressions. RESULTS: The mean ADI was 6.54 (standard deviation = 2.09). ADI groups did not significantly differ in age of presentation, type of presentation, or associated conditions, except for the higher ADI group having on average lower vitamin D levels (26.70 vs. 29.91, p = 0.02) and being two times more likely to also be diagnosed with low high-density lipoprotein (HDL) levels (p = 0.04, 95% CI 1.04-3.89). Mean transaminases and histopathologic nonalcoholic fatty liver disease (NAFLD) Activity Scores did not significantly differ between ADI groups. CONCLUSIONS: Pediatric patients with MASLD in this study span the entire spectrum of neighborhood deprivation. There were no differences in presentation characteristics or severity of MASLD, aside from lower HDL-cholesterol and vitamin D values in the high ADI group. Area deprivation was not predictive of more severe disease as assessed by serum transaminases and liver biopsy NAFLD activity scores.
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Características de Residência , Humanos , Masculino , Estudos Transversais , Feminino , Criança , Estudos Retrospectivos , Adolescente , Pré-Escolar , Índice de Gravidade de Doença , Hepatopatia Gordurosa não Alcoólica/complicações , Fígado Gorduroso/etiologia , Fígado/patologiaRESUMO
It is the realization of a long-dreamed aspiration to create a university that would advance global health delivery by training a new generation of global health leaders who are equipped to not just build, but sustain effective and equitable health systems.
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Dermatologia , Humanos , RuandaRESUMO
INTRODUCTION: Typically, oncology is not a structured part of the curriculum in Brazilian medical schools. Furthermore, sarcomas, which are uncommon tumors, are seldom covered in depth. A lack of comprehensive education on sarcomas might result in medical professionals being ill-equipped to care for patients with this condition. OBJECTIVES: To assess medical students' understanding and awareness of sarcomas and the specific principles related to these tumors. MATERIALS AND METHODS: A quantitative, cross-sectional study was conducted using a questionnaire, applied to medical students, focusing on the epidemiology, pathophysiology, and treatments of bone and soft tissue sarcomas. In all tests, the significance level adopted was 5%. The SPSS version 25.0 software was used. RESULTS: Of the 825 questionnaires distributed, 325 were returned. Educational sessions on sarcomas did not appear to significantly improve the student's knowledge. Only 29.5% of students identified the lack of pain as an indicator of potential malignancy in soft tissue sarcomas, while 73.8% correctly recognized pain as a symptom of bone sarcomas. Limb amputation as the optimal surgical method for patient recovery was incorrectly reported by 39.1% of the sample. CONCLUSION: A great part of the surveyed population does not have adequate knowledge about the basic concepts associated with limb sarcomas. The minority of them are satisfied with the knowledge gained during their medical education about these tumors. Inadequate medical academic training may initially lead to the wrong clinical management of patients with bone and soft tissue tumor lesions. An educational effort is needed to enhance oncology education for medical students, especially concerning sarcomas.
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Sarcoma , Estudantes de Medicina , Humanos , Estudos Transversais , Sarcoma/diagnóstico , Sarcoma/epidemiologia , Sarcoma/terapia , Currículo , DorRESUMO
OBJECTIVE: This study aims to reduce the waste generated from primary cleft lip and/or palate (CL/P) repair. DESIGN: A retrospective chart review examined a single surgeon's experience with CL/P repair using standard draping technique and reduced draping technique. Fisher's exact tests were performed comparing complication rates between techniques. SETTING: All procedures were conducted at a single academic medical center under the care of a board-certified pediatric plastic surgeon and fellowship-trained pediatric anesthesiologists. PATIENTS: The study included all patients ≤ 24 months of age who underwent primary CL/P repair using a reduced draping technique at the senior author's institution. An equivalent number of patients who underwent CL/P repair by the senior author immediately prior to implementation of the reduced draping technique were included for comparison. INTERVENTION: Patients undergoing CL/P repair before the change in technique were draped using the standard CL/P draping. The senior author then switched to using a reduced draping on all CL/P repairs afterwards. MAIN OUTCOME MEASURES: Weights and costs of both draping sets were obtained and differences calculated. A manual chart review was performed to assess rates of accidental intraoperative extubation, postoperative infection, fistula formation, and wound dehiscence. RESULTS: The implementation of a reduced draping technique resulted in a 530 gram weight savings and $7.49 cost savings per procedure. Fisher's exact tests revealed no statistically significant differences in complication rates except for oral mucosal dehiscence, which was lower in the reduced draping group. CONCLUSIONS: Reduced draping in CL/P repairs significantly reduces operative waste without compromising surgical outcomes.
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The cytokine storm in SARS-CoV-2 infection contributes to the onset of inflammation and target-organ damage. The endothelium is a key player in COVID-19 pathophysiology and it is an important target for cytokines. Considering that cytokines trigger oxidative stress and negatively impact endothelial cell function, we sought to determine whether serum from individuals with severe COVID-19 decreases endothelial cells' main antioxidant defense, i.e., the antioxidant transcriptional factor Nrf2. Human umbilical vein endothelial cells (HUVECs) were incubated with serum from patients with severe COVID-19 at different time points and the effects on redox balance and Nrf2 activity were determined. Serum from individuals with COVID-19 increased oxidant species, as indicated by higher DHE (dihydroethydine) oxidation, increased protein carbonylation, and induced mitochondrial reactive oxygen species (ROS) generation and dysfunction. Serum from patients with COVID-19, but not serum from healthy individuals, induced cell death and diminished nitric oxide (NO) bioavailability. In parallel, Nrf2 nuclear accumulation and the expression of Nrf2-targeted genes were decreased in endothelial cells exposed to serum from individuals with COVID-19. In addition, these cells exhibited higher expression of Bach-1, a negative regulator of Nrf2 that competes for DNA binding. All events were prevented by tocilizumab, an IL-6 receptor blocker, indicating that IL-6 is key to the impairment of endothelial antioxidant defense. In conclusion, endothelial dysfunction related to SARS-CoV-2 infection is linked to decreased endothelial antioxidant defense via IL-6-dependent mechanisms. Pharmacological activation of Nrf2 may decrease endothelial cell damage in individuals with severe COVID-19.NEW & NOTEWORTHY We demonstrate that endothelial cell dysfunction in SARS-CoV-2-infected individuals is linked to decreased activity of the major antioxidant system regulator, the Nrf2 transcription factor. We provide evidence that this phenomenon relies on IL-6, an important cytokine involved in the pathophysiology of COVID-19. Our data support the view that Nrf2 activation is a potential therapeutical strategy to prevent oxidative stress and vascular inflammation in severe cases of COVID-19.
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Antioxidantes , COVID-19 , Humanos , Antioxidantes/farmacologia , Antioxidantes/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Regulação para Baixo , Síndrome da Liberação de Citocina , Interleucina-6/metabolismo , Células Cultivadas , SARS-CoV-2/metabolismo , Estresse Oxidativo , Células Endoteliais da Veia Umbilical Humana/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Citocinas/metabolismoRESUMO
PURPOSE: Among women with non-metastatic breast cancer, marked disparities in stage at presentation, receipt of guideline-concordant treatment and stage-specific survival have been shown in national cohorts based on race, ethnicity, insurance and language. Little is published on the performance of safety-net hospitals to achieve equitable care. We evaluate differences in treatment and survival by race, ethnicity, language and insurance status among women with non-metastatic invasive breast cancer at a single, urban academic safety-net hospital. METHODS: We conducted a retrospective study of patients with invasive ductal or lobular breast cancer, diagnosed and treated between 2009 and 2014 at an urban, academic safety-net hospital. Demographic, tumor and treatment characteristics were obtained. Stage at presentation, stage-specific overall survival, and receipt of guideline-concordant surgical and adjuvant therapies were analyzed. Chi-square analysis and ANOVA were used for statistical analysis. Unadjusted survival analysis was conducted by Kaplan-Meier method using log-rank test; adjusted 5 year survival analysis was completed stratified by early and late stage, using flexible parametric survival models incorporating age, race, primary language and insurance status. RESULTS: 520 women with stage 1-3 invasive breast cancer were identified. Median age was 58.5 years, 56.1% were non-white, 31.7% were non-English-speaking, 16.4% were Hispanic, and 50.1% were Medicaid/uninsured patients. There were no statistically significant differences in stage at presentation between age group, race, ethnicity, language or insurance. The rate of breast conserving surgery (BCS) among stage 1-2 patients did not vary by race, insurance or language. Among patients indicated for adjuvant therapies, the rates of recommendation and completion of therapy did not vary by race, ethnicity, insurance or language. Unadjusted survival at 5 years was 93.7% for stage 1-2 and 73.5% for stage 3. Adjusting for age, race, insurance status and primary language, overall survival at 5 years was 93.8% (95% CI 86.3-97.2%) for stage 1-2 and 83.4% (95% CI 35.5-96.9%) for stage 3 disease. Independently, for patients with early- and late-stage disease, age, race, language and insurance were not associated with survival at 5-years. CONCLUSION: Among patients diagnosed and treated at an academic safety-net hospital, there were no differences in the stage at presentation or receipt of guideline-concordant treatment by race, ethnicity, insurance or language. Overall survival did not vary by race, insurance or language. Additional research is needed to assess how hospitals and healthcare systems mitigate breast cancer disparities.
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Neoplasias da Mama , Disparidades em Assistência à Saúde , Feminino , Humanos , Pessoa de Meia-Idade , Neoplasias da Mama/patologia , Etnicidade , Estudos Retrospectivos , Provedores de Redes de Segurança , Estados Unidos/epidemiologiaRESUMO
Demographic factors are fundamental in shaping infectious disease dynamics. Aspects of populations that create structure, like age and sex, can affect patterns of transmission, infection intensity and population outcomes. However, studies rarely link these processes from individual to population-scale effects. Moreover, the mechanisms underlying demographic differences in disease are frequently unclear. Here, we explore sex-biased infections for a multi-host fungal disease of bats, white-nose syndrome, and link disease-associated mortality between sexes, the distortion of sex ratios and the potential mechanisms underlying sex differences in infection. We collected data on host traits, infection intensity and survival of five bat species at 42 sites across seven years. We found females were more infected than males for all five species. Females also had lower apparent survival over winter and accounted for a smaller proportion of populations over time. Notably, female-biased infections were evident by early hibernation and likely driven by sex-based differences in autumn mating behaviour. Male bats were more active during autumn which likely reduced replication of the cool-growing fungus. Higher disease impacts in female bats may have cascading effects on bat populations beyond the hibernation season by limiting recruitment and increasing the risk of Allee effects.
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Quirópteros , Hibernação , Micoses , Feminino , Masculino , Animais , Animais Selvagens , Quirópteros/microbiologia , Micoses/epidemiologia , Micoses/veterinária , Micoses/microbiologia , FungosRESUMO
The NOD-like receptor pyrin domain-containing protein 3 (NLRP3) inflammasome is a multiprotein complex and component of the innate immune system that is activated by exogenous and endogenous danger signals to promote activation of caspase-1 and the maturation and release of the proinflammatory cytokines interleukin (IL)-1ß and IL-18. Inappropriate activation of NLRP3 has been implicated in the pathophysiology of multiple inflammatory and autoimmune diseases, including cardiovascular disease, neurodegenerative diseases, and nonalcoholic steatohepatitis (NASH), thus increasing the clinical interest of this target. We describe in this study the preclinical pharmacologic, pharmacokinetic, and pharmacodynamic properties of a novel and highly specific NLRP3 inhibitor, JT001 (6,7-dihydro-5H-pyrazolo[5,1-b][1,3]oxazine-3-sulfonylurea). In cell-based assays, JT001 potently and selectively inhibited NLRP3 inflammasome assembly, resulting in the inhibition of cytokine release and the prevention of pyroptosis, a form of inflammatory cell death triggered by active caspase-1. Oral administration of JT001 to mice inhibited IL-1ß production in peritoneal lavage fluid at plasma concentrations that correlated with mouse in vitro whole blood potency. Orally administered JT001 was effective in reducing hepatic inflammation in three different murine models, including the Nlrp3A350V /+CreT model of Muckle-Wells syndrome (MWS), a diet-induced obesity NASH model, and a choline-deficient diet-induced NASH model. Significant reductions in hepatic fibrosis and cell damage were also observed in the MWS and choline-deficient models. Our findings demonstrate that blockade of NLRP3 attenuates hepatic inflammation and fibrosis and support the use of JT001 to investigate the role of NLRP3 in other inflammatory disease models. SIGNIFICANCE STATEMENT: Persistent inflammasome activation is the consequence of inherited mutations of NLRP3 and results in the development of cryopyrin-associated periodic syndromes associated with severe systemic inflammation. NLRP3 is also upregulated in nonalcoholic steatohepatitis, a metabolic chronic liver disease currently missing a cure. Selective and potent inhibitors of NLRP3 hold great promise and have the potential to overcome an urgent unmet need.
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Hepatopatia Gordurosa não Alcoólica , Camundongos , Animais , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/metabolismo , Inflamassomos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Proteínas NLR , Domínio Pirina , Cirrose Hepática/tratamento farmacológico , Cirrose Hepática/prevenção & controle , Caspase 1/metabolismo , Inflamação , Colina/efeitos adversos , Interleucina-1beta/metabolismoRESUMO
Intercalation-type metal oxides are promising negative electrode materials for safe rechargeable lithium-ion batteries due to the reduced risk of Li plating at low voltages. Nevertheless, their lower energy and power density along with cycling instability remain bottlenecks for their implementation, especially for fast-charging applications. Here, we report a nanostructured rock-salt Nb2O5 electrode formed through an amorphous-to-crystalline transformation during repeated electrochemical cycling with Li+. This electrode can reversibly cycle three lithiums per Nb2O5, corresponding to a capacity of 269 mAh g-1 at 20 mA g-1, and retains a capacity of 191 mAh g-1 at a high rate of 1 A g-1. It exhibits superb cycling stability with a capacity of 225 mAh g-1 at 200 mA g-1 for 400 cycles, and a Coulombic efficiency of 99.93%. We attribute the enhanced performance to the cubic rock-salt framework, which promotes low-energy migration paths. Our work suggests that inducing crystallization of amorphous nanomaterials through electrochemical cycling is a promising avenue for creating unconventional high-performance metal oxide electrode materials.
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Coronavirus disease 2019 (COVID-19) infection has a negative impact on the cytokine profile of pregnant women. Increased levels of proinflammatory cytokines seem to be correlated with the severity of the disease, in addition to predisposing to miscarriage or premature birth. Proinflammatory cytokines increase the generation of reactive oxygen species (ROS). It is unclear how interleukin-6 (IL-6) found in the circulation of patients with severe COVID-19 might affect gestational health, particularly concerning umbilical cord function. This study tested the hypothesis that IL-6 present in the circulation of women with severe COVID-19 causes umbilical cord artery dysfunction by increasing ROS generation and activating redox-sensitive proteins. Umbilical cord arteries were incubated with serum from healthy women and women with severe COVID-19. Vascular function was assessed using concentration-effect curves to serotonin in the presence or absence of pharmacological agents, such as tocilizumab (antibody against the IL-6 receptor), tiron (ROS scavenger), ML171 (Nox1 inhibitor), and Y27632 (Rho kinase inhibitor). ROS generation was assessed by the dihydroethidine probe and Rho kinase activity by an enzymatic assay. Umbilical arteries exposed to serum from women with severe COVID-19 were hyperreactive to serotonin. This effect was abolished in the presence of tocilizumab, tiron, ML171, and Y27632. In addition, serum from women with severe COVID-19 increased Nox1-dependent ROS generation and Rho kinase activity. Increased Rho kinase activity was abolished by tocilizumab and tiron. Serum cytokines in women with severe COVID-19 promote umbilical artery dysfunction. IL-6 is key to Nox-linked vascular oxidative stress and activation of the Rho kinase pathway.
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COVID-19 , Interleucina-6 , Feminino , Humanos , Gravidez , Sal Dissódico do Ácido 1,2-Di-Hidroxibenzeno-3,5 Dissulfônico , Artérias/metabolismo , Citocinas , Espécies Reativas de Oxigênio/metabolismo , Quinases Associadas a rho , Serotonina , Cordão UmbilicalRESUMO
BACKGROUND AND AIMS: The NOD-like receptor protein 3 (NLRP3) inflammasome is a central contributor to human acute and chronic liver disease, yet the molecular and cellular mechanisms by which its activation precipitates injury remain incompletely understood. Here, we present single cell transcriptomic profiling of livers from a global transgenic tamoxifen-inducible constitutively activated Nlrp3A350V mutant mouse, and we investigate the changes in parenchymal and nonparenchymal liver cell gene expression that accompany inflammation and fibrosis. APPROACH AND RESULTS: Our results demonstrate that NLRP3 activation causes chronic extramedullary myelopoiesis marked by myeloid progenitors that differentiate into proinflammatory neutrophils, monocytes, and monocyte-derived macrophages. We observed prominent neutrophil infiltrates with increased Ly6gHI and Ly6gINT cells exhibiting transcriptomic signatures of granulopoiesis typically found in the bone marrow. This was accompanied by a marked increase in Ly6cHI monocytes differentiating into monocyte-derived macrophages that express transcriptional programs similar to macrophages of NASH models. NLRP3 activation also down-regulated metabolic pathways in hepatocytes and shifted hepatic stellate cells toward an activated profibrotic state based on expression of collagen and extracellular matrix regulatory genes. CONCLUSIONS: These results define the single cell transcriptomes underlying hepatic inflammation and fibrosis precipitated by NLRP3 activation. Clinically, our data support the notion that NLRP3-induced mechanisms should be explored as therapeutic target in NASH-like inflammation.
Assuntos
Proteína 3 que Contém Domínio de Pirina da Família NLR , Hepatopatia Gordurosa não Alcoólica , Animais , Fibrose , Humanos , Inflamassomos/metabolismo , Inflamação , Camundongos , Proteína 3 que Contém Domínio de Pirina da Família NLR/fisiologia , Proteínas NLRRESUMO
Antibody-drug conjugates (ADCs) have garnered worldwide attention for disease treatment, as they possess high target specificity, a long half-life, and outstanding potency to kill or modulate the functions of targets. FDA approval of multiple ADCs for cancer therapy has generated a strong desire for novel conjugation strategies with high biocompatibility and controllable bioproperties. Herein, we present a bisecting glycan-bridged conjugation strategy that enables site-specific conjugation without the need for the oligosaccharide synthesis and genetic engineering of antibodies. Application of this method is demonstrated by conjugation of anti-HER2 human and mouse IgGs with a cytotoxic drug, monomethyl auristatin E. The glycan bridge showed outstanding stability, and the resulting ADCs eliminated HER2-expressing cancer cells effectively. Moreover, our strategy preserves the feasibility of glycan structure remodeling to fine-tune the immunogenicity and pharmacokinetic properties of ADCs through glycoengineering.