RESUMO
The rise of antibiotic resistance and declining discovery of new antibiotics has created a global health crisis. Of particular concern, no new antibiotic classes have been approved for treating Gram-negative pathogens in decades. Here, we characterize a compound, SCH-79797, that kills both Gram-negative and Gram-positive bacteria through a unique dual-targeting mechanism of action (MoA) with undetectably low resistance frequencies. To characterize its MoA, we combined quantitative imaging, proteomic, genetic, metabolomic, and cell-based assays. This pipeline demonstrates that SCH-79797 has two independent cellular targets, folate metabolism and bacterial membrane integrity, and outperforms combination treatments in killing methicillin-resistant Staphylococcus aureus (MRSA) persisters. Building on the molecular core of SCH-79797, we developed a derivative, Irresistin-16, with increased potency and showed its efficacy against Neisseria gonorrhoeae in a mouse vaginal infection model. This promising antibiotic lead suggests that combining multiple MoAs onto a single chemical scaffold may be an underappreciated approach to targeting challenging bacterial pathogens.
Assuntos
Bactérias Gram-Negativas/efeitos dos fármacos , Pirróis/metabolismo , Pirróis/farmacologia , Quinazolinas/metabolismo , Quinazolinas/farmacologia , Animais , Antibacterianos/farmacologia , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Farmacorresistência Bacteriana/efeitos dos fármacos , Farmacorresistência Bacteriana/genética , Feminino , Ácido Fólico/metabolismo , Bactérias Gram-Positivas/efeitos dos fármacos , Células HEK293 , Humanos , Masculino , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana , Ovariectomia , Proteômica , Pseudomonas aeruginosa/efeitos dos fármacosRESUMO
Resident-tissue macrophages (RTMs) arise from embryonic precursors1,2, yet the developmental signals that shape their longevity remain largely unknown. Here we demonstrate in mice genetically deficient in 12-lipoxygenase and 15-lipoxygenase (Alox15-/- mice) that neonatal neutrophil-derived 12-HETE is required for self-renewal and maintenance of alveolar macrophages (AMs) during lung development. Although the seeding and differentiation of AM progenitors remained intact, the absence of 12-HETE led to a significant reduction in AMs in adult lungs and enhanced senescence owing to increased prostaglandin E2 production. A compromised AM compartment resulted in increased susceptibility to acute lung injury induced by lipopolysaccharide and to pulmonary infections with influenza A virus or SARS-CoV-2. Our results highlight the complexity of prenatal RTM programming and reveal their dependency on in trans eicosanoid production by neutrophils for lifelong self-renewal.
Assuntos
Ácido 12-Hidroxi-5,8,10,14-Eicosatetraenoico , Autorrenovação Celular , Macrófagos Alveolares , Neutrófilos , Animais , Camundongos , Ácido 12-Hidroxi-5,8,10,14-Eicosatetraenoico/metabolismo , Lesão Pulmonar Aguda , Animais Recém-Nascidos , Araquidonato 12-Lipoxigenase/deficiência , Araquidonato 15-Lipoxigenase/deficiência , COVID-19 , Vírus da Influenza A , Lipopolissacarídeos , Pulmão/citologia , Pulmão/virologia , Macrófagos Alveolares/citologia , Macrófagos Alveolares/metabolismo , Neutrófilos/metabolismo , Infecções por Orthomyxoviridae , Prostaglandinas E , SARS-CoV-2 , Suscetibilidade a DoençasRESUMO
The heart, the first organ to develop in the embryo, undergoes complex morphogenesis that when defective results in congenital heart disease (CHD). With current therapies, more than 90% of patients with CHD survive into adulthood, but many suffer premature death from heart failure and non-cardiac causes1. Here, to gain insight into this disease progression, we performed single-nucleus RNA sequencing on 157,273 nuclei from control hearts and hearts from patients with CHD, including those with hypoplastic left heart syndrome (HLHS) and tetralogy of Fallot, two common forms of cyanotic CHD lesions, as well as dilated and hypertrophic cardiomyopathies. We observed CHD-specific cell states in cardiomyocytes, which showed evidence of insulin resistance and increased expression of genes associated with FOXO signalling and CRIM1. Cardiac fibroblasts in HLHS were enriched in a low-Hippo and high-YAP cell state characteristic of activated cardiac fibroblasts. Imaging mass cytometry uncovered a spatially resolved perivascular microenvironment consistent with an immunodeficient state in CHD. Peripheral immune cell profiling suggested deficient monocytic immunity in CHD, in agreement with the predilection in CHD to infection and cancer2. Our comprehensive phenotyping of CHD provides a roadmap towards future personalized treatments for CHD.
Assuntos
Cardiopatias Congênitas , Fenótipo , Receptores de Proteínas Morfogenéticas Ósseas/metabolismo , Cardiomiopatia Dilatada/genética , Cardiomiopatia Dilatada/imunologia , Cardiomiopatia Dilatada/metabolismo , Cardiomiopatia Dilatada/patologia , Cardiomiopatia Hipertrófica/genética , Cardiomiopatia Hipertrófica/imunologia , Cardiomiopatia Hipertrófica/metabolismo , Cardiomiopatia Hipertrófica/patologia , Progressão da Doença , Fibroblastos/metabolismo , Fibroblastos/patologia , Fatores de Transcrição Forkhead/metabolismo , Cardiopatias Congênitas/genética , Cardiopatias Congênitas/imunologia , Cardiopatias Congênitas/metabolismo , Cardiopatias Congênitas/patologia , Humanos , Síndrome do Coração Esquerdo Hipoplásico/genética , Síndrome do Coração Esquerdo Hipoplásico/imunologia , Síndrome do Coração Esquerdo Hipoplásico/metabolismo , Síndrome do Coração Esquerdo Hipoplásico/patologia , Citometria por Imagem , Resistência à Insulina , Monócitos/imunologia , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , RNA-Seq , Transdução de Sinais/genética , Análise de Célula Única , Tetralogia de Fallot/genética , Tetralogia de Fallot/imunologia , Tetralogia de Fallot/metabolismo , Tetralogia de Fallot/patologia , Proteínas de Sinalização YAP/metabolismoRESUMO
Cardiac fibroblasts (CFs) respond to injury by transitioning through multiple cell states, including resting CFs, activated CFs, and myofibroblasts. We report here that Hippo signaling cell-autonomously regulates CF fate transitions and proliferation, and non-cell-autonomously regulates both myeloid and CF activation in the heart. Conditional deletion of Hippo pathway kinases, Lats1 and Lats2, in uninjured CFs initiated a self-perpetuating fibrotic response in the adult heart that was exacerbated by myocardial infarction (MI). Single cell transcriptomics showed that uninjured Lats1/2 mutant CFs spontaneously transitioned to a myofibroblast cell state. Through gene regulatory network reconstruction, we found that Hippo-deficient myofibroblasts deployed a network of transcriptional regulators of endoplasmic reticulum (ER) stress, and the unfolded protein response (UPR) consistent with elevated secretory activity. We observed an expansion of myeloid cell heterogeneity in uninjured Lats1/2 CKO hearts with similarity to cells recovered from control hearts post-MI. Integrated genome-wide analysis of Yap chromatin occupancy revealed that Yap directly activates myofibroblast cell identity genes, the proto-oncogene Myc, and an array of genes encoding pro-inflammatory factors through enhancer-promoter looping. Our data indicate that Lats1/2 maintain the resting CF cell state through restricting the Yap-induced injury response.
Assuntos
Fibroblastos/citologia , Fibrose/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais/genética , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Proteínas de Ciclo Celular/metabolismo , Fibroblastos/patologia , Fibrose/fisiopatologia , Deleção de Genes , Camundongos Endogâmicos C57BL , Infarto do Miocárdio/fisiopatologia , Proteínas de Sinalização YAPRESUMO
Mitochondria, which act as sensors of metabolic homeostasis and metabolite signaling, form a dynamic intracellular network that continuously changes shape, size and localization to respond to localized cellular energy demands. Mitochondrial dynamics and function depend on interactions with the F-actin cytoskeleton that are poorly understood. Here, we show that SET domain protein 3 (SETD3), a recently described actin histidine methyltransferase, directly methylates actin at histidine-73 and enhances F-actin polymerization on mitochondria. SETD3 is a mechano-sensitive enzyme that is localized on the outer mitochondrial membrane and promotes actin polymerization around mitochondria. SETD3 loss of function leads to diminished F-actin around mitochondria and a decrease in mitochondrial branch length, branch number and mitochondrial movement. Our functional analysis revealed that SETD3 is required for oxidative phosphorylation, and mitochondrial complex I assembly and function. Our data further indicate that SETD3 regulates F-actin formation around mitochondria and is essential for maintaining mitochondrial morphology, movement and function. Finally, we discovered that SETD3 levels are regulated by extracellular matrix (ECM) stiffness and regulate mitochondrial shape in response to changes in ECM stiffness. These findings provide new insight into the mechanism for F-actin polymerization around mitochondria.
Assuntos
Actinas , Mitocôndrias , Dinâmica Mitocondrial , Actinas/metabolismo , Humanos , Mitocôndrias/metabolismo , Metilação , Histidina/metabolismo , Matriz Extracelular/metabolismo , Metiltransferases/metabolismo , Metiltransferases/genética , Animais , Células HeLa , Histona MetiltransferasesRESUMO
BACKGROUND: Delays in the detection or treatment of postpartum hemorrhage can result in complications or death. A blood-collection drape can help provide objective, accurate, and early diagnosis of postpartum hemorrhage, and delayed or inconsistent use of effective interventions may be able to be addressed by a treatment bundle. METHODS: We conducted an international, cluster-randomized trial to assess a multicomponent clinical intervention for postpartum hemorrhage in patients having vaginal delivery. The intervention included a calibrated blood-collection drape for early detection of postpartum hemorrhage and a bundle of first-response treatments (uterine massage, oxytocic drugs, tranexamic acid, intravenous fluids, examination, and escalation), supported by an implementation strategy (intervention group). Hospitals in the control group provided usual care. The primary outcome was a composite of severe postpartum hemorrhage (blood loss, ≥1000 ml), laparotomy for bleeding, or maternal death from bleeding. Key secondary implementation outcomes were the detection of postpartum hemorrhage and adherence to the treatment bundle. RESULTS: A total of 80 secondary-level hospitals across Kenya, Nigeria, South Africa, and Tanzania, in which 210,132 patients underwent vaginal delivery, were randomly assigned to the intervention group or the usual-care group. Among hospitals and patients with data, a primary-outcome event occurred in 1.6% of the patients in the intervention group, as compared with 4.3% of those in the usual-care group (risk ratio, 0.40; 95% confidence interval [CI], 0.32 to 0.50; P<0.001). Postpartum hemorrhage was detected in 93.1% of the patients in the intervention group and in 51.1% of those in the usual-care group (rate ratio, 1.58; 95% CI, 1.41 to 1.76), and the treatment bundle was used in 91.2% and 19.4%, respectively (rate ratio, 4.94; 95% CI, 3.88 to 6.28). CONCLUSIONS: Early detection of postpartum hemorrhage and use of bundled treatment led to a lower risk of the primary outcome, a composite of severe postpartum hemorrhage, laparotomy for bleeding, or death from bleeding, than usual care among patients having vaginal delivery. (Funded by the Bill and Melinda Gates Foundation; E-MOTIVE ClinicalTrials.gov number, NCT04341662.).
Assuntos
Diagnóstico Precoce , Hemorragia Pós-Parto , Feminino , Humanos , Gravidez , Ocitócicos/uso terapêutico , Hemorragia Pós-Parto/diagnóstico , Hemorragia Pós-Parto/terapia , Risco , Ácido Tranexâmico/uso terapêuticoRESUMO
BACKGROUND: Much of our knowledge of organ rejection after transplantation is derived from rodent models. METHODS: We used single-nucleus RNA sequencing to investigate the inflammatory myocardial microenvironment in human pediatric cardiac allografts at different stages after transplantation. We distinguished donor- from recipient-derived cells using naturally occurring genetic variants embedded in single-nucleus RNA sequencing data. RESULTS: Donor-derived tissue resident macrophages, which accompany the allograft into the recipient, are lost over time after transplantation. In contrast, monocyte-derived macrophages from the recipient populate the heart within days after transplantation and form 2 macrophage populations: recipient MP1 and recipient MP2. Recipient MP2s have cell signatures similar to donor-derived resident macrophages; however, they lack signatures of pro-reparative phagocytic activity typical of donor-derived resident macrophages and instead express profibrotic genes. In contrast, recipient MP1s express genes consistent with hallmarks of cellular rejection. Our data suggest that recipient MP1s activate a subset of natural killer cells, turning them into a cytotoxic cell population through feed-forward signaling between recipient MP1s and natural killer cells. CONCLUSIONS: Our findings reveal an imbalance of donor-derived and recipient-derived macrophages in the pediatric cardiac allograft that contributes to allograft failure.
Assuntos
Aloenxertos , Rejeição de Enxerto , Transplante de Coração , Macrófagos , Humanos , Transplante de Coração/efeitos adversos , Macrófagos/metabolismo , Rejeição de Enxerto/imunologia , Rejeição de Enxerto/genética , Masculino , Feminino , Criança , Pré-Escolar , Miocárdio/patologia , Sobrevivência de Enxerto , Lactente , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/metabolismo , AdolescenteRESUMO
In asthma, CD4+ T-cell interaction with airway smooth muscle (ASM) may enhance its contractile properties and promote its proliferation. However, less is known about the effects of this interaction on T cells. To explore the consequences of interaction of CD4+ T cells with ASM we placed the cells in co-culture and analyzed the phenotypic and functional changes in the T cells. Effector status as well as cytokine expression was assessed by flow cytometry. An increase in CD45RA-CD45RO+ memory T cells was observed after co-culture; however, these cells were not more responsive to CD3/28 restimulation. A reduction in mitochondrial coupling and an increase in the production of mitochondrial reactive oxygen species by CD4+ T cells post-restimulation suggested altered mitochondrial metabolism after co-culture. RNA sequencing analysis of the T cells revealed characteristic downregulation of effector T-cell-associated genes, but a lack of upregulation of memory T-cell-associated genes. The results of this study demonstrate that ASM cells can induce a phenotypic shift in CD4+ T cells into memory-like T cells but with reduced capacity for activation.
Assuntos
Miócitos de Músculo Liso , Sistema Respiratório , Miócitos de Músculo Liso/metabolismo , Técnicas de Cocultura , Linfócitos T CD4-Positivos , FenótipoRESUMO
Hippo signaling, an evolutionarily conserved kinase cascade involved in organ size control, plays key roles in various tissue developmental processes, but its role in craniofacial development remains poorly understood. Using the transgenic Wnt1-Cre2 driver, we inactivated the Hippo signaling components Lats1 and Lats2 in the cranial neuroepithelium of mouse embryos and found that the double conditional knockout (DCKO) of Lats1/2 resulted in neural tube and craniofacial defects. Lats1/2 DCKO mutant embryos had microcephaly with delayed and defective neural tube closure. Furthermore, neuroepithelial cell shape and architecture were disrupted within the cranial neural tube in Lats1/2 DCKO mutants. RNA sequencing of embryonic neural tubes revealed increased TGFB signaling in Lats1/2 DCKO mutants. Moreover, markers of epithelial-to-mesenchymal transition (EMT) were upregulated in the cranial neural tube. Inactivation of Hippo signaling downstream effectors, Yap and Taz, suppressed neuroepithelial defects, aberrant EMT and TGFB upregulation in Lats1/2 DCKO embryos, indicating that LATS1/2 function via YAP and TAZ. Our findings reveal important roles for Hippo signaling in modulating TGFB signaling during neural crest EMT.
Assuntos
Proteínas de Ciclo Celular , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Animais , Proteínas de Ciclo Celular/genética , Transição Epitelial-Mesenquimal/genética , Camundongos , Proteínas Serina-Treonina Quinases/genética , Transdução de Sinais/genética , Crânio , Fator de Crescimento Transformador beta/metabolismoRESUMO
Airway smooth muscle (ASM) remodeling in asthmatic airways may contribute to persistent airflow limitation and airway hyperresponsiveness. CD4+ T cells infiltrate the ASM layer where they may induce a proliferative and secretory ASM cell phenotype. We studied the interaction between activated CD4+ T cells and ASM cells in co-culture in vitro and investigated the effects of CD4+ T cells on chemokine production by ASM cells. CD4+ T cells induced marked upregulation of C-X-C motif chemokine ligands (CXCL) 9, 10, and 11 in ASM cells. Blockade of the IFN-γ receptor on ASM cells prevented this upregulation. Furthermore, T cell-derived IFN-γ and LIGHT (lymphotoxin, exhibits inducible expression and competes with HSV glycoprotein D for binding to herpesvirus entry mediator, a receptor expressed on T lymphocytes) synergize in a dose-dependent manner to coordinately enhance CXCL9, 10, and 11 expression. The synergistic property of LIGHT was mediated exclusively through the lymphotoxin-ß receptor (LTBR), but not herpes virus entry mediator (HVEM). Disruption of LTBR signaling in ASM cells reduced CXCL9, 10, and 11 production and ASM cell-mediated CD4+ T cell chemotaxis. We conclude that the LIGHT-LTBR signaling axis acts together with IFN-γ to regulate chemokines that mediate lymphocyte infiltration in asthmatics.
Assuntos
Asma , Linfócitos T , Humanos , Miócitos de Músculo Liso , Músculo Liso , Remodelação das Vias Aéreas , Linfócitos T CD4-PositivosRESUMO
The transcription factors (TFs) MyoCD (myocardin) and Elk-1 (ETS Like-1 protein) competitively bind to SRF (serum response factor) and control myogenic- and mitogenic-related gene expression in smooth muscle, respectively. Their functions are therefore mutually inhibitory, which results in a contractile-versus-proliferative phenotype dichotomy. Airway smooth muscle cell (ASMC) phenotype alterations occur in various inflammatory airway diseases, promoting pathological remodeling and contributing to airflow obstruction. We characterized MyoCD and Elk-1 interactions and their roles in phenotype determination in human ASMCs. MyoCD overexpression in ASMCs increased smooth muscle gene expression, force generation, and partially restored the loss of smooth muscle protein associated with prolonged culturing while inhibiting Elk-1 transcriptional activities and proliferation induced by EGF (epidermal growth factor). However, MyoCD overexpression failed to suppress these responses induced by FBS, as FBS also upregulated SRF expression to a degree that allowed unopposed function of both TFs. Inhibition of the RhoA pathway reversed said SRF changes, allowing inhibition of Elk-1 by MyoCD overexpression and suppressing FBS-mediated contractile protein gene upregulation. Our study confirmed that MyoCD in increased abundance can competitively inhibit Elk-1 function. However, SRF upregulation permits a dual contractile-proliferative ASMC phenotype that is anticipated to exacerbate pathological alterations, whereas therapies targeting SRF may inhibit pathological ASMC proliferation and contractile protein gene expression.
Assuntos
Proliferação de Células , Contração Muscular , Miócitos de Músculo Liso , Proteínas Nucleares , Fenótipo , Fator de Resposta Sérica , Transativadores , Proteínas Elk-1 do Domínio ets , Proteína rhoA de Ligação ao GTP , Humanos , Fator de Resposta Sérica/metabolismo , Fator de Resposta Sérica/genética , Proteínas Elk-1 do Domínio ets/metabolismo , Proteínas Elk-1 do Domínio ets/genética , Miócitos de Músculo Liso/metabolismo , Miócitos de Músculo Liso/patologia , Proteína rhoA de Ligação ao GTP/metabolismo , Transativadores/metabolismo , Transativadores/genética , Proteínas Nucleares/metabolismo , Proteínas Nucleares/genética , Células Cultivadas , Regulação da Expressão Gênica , Transdução de Sinais , Fator de Crescimento Epidérmico/metabolismoRESUMO
Crosstalk between T cells and airway smooth muscle (ASM) may play a role in modulating asthmatic airway inflammation and remodelling. Infiltrating T cells have been observed within the ASM bundles of asthmatics, and a wide range of direct and indirect interactions between T cells and ASM have been demonstrated using various in vitro and in vivo model systems. Contact-dependent mechanisms such as ligation and activation of cellular adhesion and costimulatory molecules, as well as the formation of lymphocyte-derived membrane conduits, facilitate the adhesion, bidirectional communication and transfer of materials between T and ASM cells. T cell-derived cytokines, particularly of the Th1, Th2 and Th17 subsets, modulate the secretome, proliferation and contractility of ASM cells. This review summarizes the mechanisms governing T cell-ASM crosstalk in the context of asthma. Understanding the underlying mechanistic basis is important for directing future research and developing therapeutic interventions targeted towards this complex interaction.
RESUMO
BACKGROUND: Mucus plugs have been described in the airways of asthmatic subjects, particularly those with associated with type 2 inflammation and sputum eosinophilia. In the current study we addressed the question of whether smoking, neutrophilic inflammation and airway dimensions affected the prevalence of mucus plugs. METHODS: In a cohort of moderate to severe asthmatics (n = 50), including a group of ex-smokers and current smokers, the prevalence of mucus plugs was quantified using a semi-quantitative score based on thoracic computerized tomography. The relationships between mucus score, sputum inflammatory profile and airway architecture were tested according to patient's smoking status. RESULTS: Among the asthmatics (37% former or active smokers), 74% had at least one mucus plug. The median score was 3 and was unrelated to smoking status. A significant but weak correlation was found between mucus score, FEV1 and FEV1/FVC. Mucus score was significantly correlated with sputum eosinophils. Among former and active smokers, mucus score was correlated with sputum neutrophils. Mucus score was positively associated with FeNO in non-smoking subjects. The lumen dimensions of the main and lobar bronchi were significantly inversely correlated with mucus score. CONCLUSION: Airway mucus plugs could define an asthma phenotype with altered airway architecture and can occur in asthmatic subjects with either neutrophilic or eosinophilic sputum according to their smoking status.
Assuntos
Asma , Humanos , Muco , Escarro , Brônquios , InflamaçãoRESUMO
Long distance enhancers can physically interact with promoters to regulate gene expression through formation of enhancer-promoter (E-P) interactions. Identification of E-P interactions is also important for profound understanding of normal developmental and disease-associated risk variants. Although the state-of-art predictive computation methods facilitate the identification of E-P interactions to a certain extent, currently there is no efficient method that can meet various requirements of usage. Here we developed EPIXplorer, a user-friendly web server for efficient prediction, analysis and visualization of E-P interactions. EPIXplorer integrates 9 robust predictive algorithms, supports multiple types of 3D contact data and multi-omics data as input. The output from EPIXplorer is scored, fully annotated by regulatory elements and risk single-nucleotide polymorphisms (SNPs). In addition, the Visualization and Downstream module provide further functional analysis, all the output files and high-quality images are available for download. Together, EPIXplorer provides a user-friendly interface to predict the E-P interactions in an acceptable time, as well as understand how the genome-wide association study (GWAS) variants influence disease pathology by altering DNA looping between enhancers and the target gene promoters. EPIXplorer is available at https://www.csuligroup.com/EPIXplorer.
Assuntos
Estudo de Associação Genômica Ampla , Sequências Reguladoras de Ácido Nucleico , Software , Humanos , Algoritmos , Computadores , Suscetibilidade a Doenças , Elementos Facilitadores Genéticos , Regiões Promotoras Genéticas , InternetRESUMO
Human genetic studies identified a strong association between loss of function mutations in RBFOX2 and hypoplastic left heart syndrome (HLHS). There are currently no Rbfox2 mouse models that recapitulate HLHS. Therefore, it is still unknown how RBFOX2 as an RNA binding protein contributes to heart development. To address this, we conditionally deleted Rbfox2 in embryonic mouse hearts and found profound defects in cardiac chamber and yolk sac vasculature formation. Importantly, our Rbfox2 conditional knockout mouse model recapitulated several molecular and phenotypic features of HLHS. To determine the molecular drivers of these cardiac defects, we performed RNA-sequencing in Rbfox2 mutant hearts and identified dysregulated alternative splicing (AS) networks that affect cell adhesion to extracellular matrix (ECM) mediated by Rho GTPases. We identified two Rho GTPase cycling genes as targets of RBFOX2. Modulating AS of these two genes using antisense oligos led to cell cycle and cell-ECM adhesion defects. Consistently, Rbfox2 mutant hearts displayed cell cycle defects and inability to undergo endocardial-mesenchymal transition, processes dependent on cell-ECM adhesion and that are seen in HLHS. Overall, our work not only revealed that loss of Rbfox2 leads to heart development defects resembling HLHS, but also identified RBFOX2-regulated AS networks that influence cell-ECM communication vital for heart development.
Assuntos
Processamento Alternativo , Coração/embriologia , Fatores de Processamento de RNA/metabolismo , Animais , Regulação da Expressão Gênica no Desenvolvimento , Camundongos , Camundongos Knockout , Organogênese , RNA/metabolismo , Fatores de Processamento de RNA/genética , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismoRESUMO
For decades, surgeons have utilized 0.9% normal saline (NS) for joint irrigation to improve visualization during arthroscopic procedures. This continues despite mounting evidence that NS exposure impairs chondrocyte metabolism and compromises articular cartilage function. We hypothesized that chondrocyte oxidative stress induced by low pH is the dominant factor driving NS toxicity, and that buffering NS to increase its pH would mitigate these effects. Effects on chondrocyte viability, reactive oxygen species (ROS) production, and overall metabolic function were assessed. Even brief exposure to NS caused cell death, ROS overproduction, and disruption of glycolysis, pentose phosphate, and tricarboxylic acid (TCA) cycle pathways. NS also stimulated ROS overproduction in synovial cells that could adversely alter the synovial function and subsequently the entire joint health. Buffering NS with 25 mM 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) significantly increased chondrocyte viability, reduced ROS production, and returned metabolite levels to near control levels while also reducing ROS production in synovial cells. These results confirm that chondrocytes and synoviocytes are vulnerable to insult from the acidic pH of NS and demonstrate that adding a buffering agent to NS averts many of its most harmful effects.
Assuntos
Cartilagem Articular , Condrócitos , Condrócitos/metabolismo , Solução Salina , Espécies Reativas de Oxigênio/metabolismo , Estresse Oxidativo/fisiologia , Morte Celular , Cartilagem Articular/metabolismoRESUMO
BACKGROUND: Chikungunya virus (CHIKV) is an arbovirus that periodically emerges to cause large epidemics of arthritic disease. Although the robust immunity elicited by live-attenuated virus (LAV) vaccine candidates makes them attractive, CHIKV vaccine development has been hampered by a high threshold for acceptable adverse events. METHODS: We evaluated the vaccine potential of a recently described LAV, skeletal muscle-restricted virus (SKE), that exhibits diminished replication in skeletal muscle due to insertion of target sequences for skeletal muscle-specific miR-206. We also evaluated whether these target sequences could augment safety of an LAV encoding a known attenuating mutation, E2 G82R. Attenuation of viruses containing these mutations was compared with a double mutant, SKE G82R. RESULTS: SKE was attenuated in both immunodeficient and immunocompetent mice and induced a robust neutralizing antibody response, indicating its vaccine potential. However, only SKE G82R elicited diminished swelling in immunocompetent mice at early time points postinoculation, indicating that these mutations synergistically enhance safety of the vaccine candidate. CONCLUSIONS: These data suggest that restriction of LAV replication in skeletal muscle enhances tolerability of reactogenic vaccine candidates and may improve the rational design of CHIKV vaccines.
Assuntos
Febre de Chikungunya , Vírus Chikungunya , Vacinas Virais , Animais , Camundongos , Vírus Chikungunya/genética , Febre de Chikungunya/prevenção & controle , Vacinas Virais/genética , Anticorpos Neutralizantes , Mutação , Vacinas Atenuadas/genética , Anticorpos AntiviraisRESUMO
Transcriptional enhancers commonly work over long genomic distances to precisely regulate spatiotemporal gene expression patterns. Dissecting the promoters physically contacted by these distal regulatory elements is essential for understanding developmental processes as well as the role of disease-associated risk variants. Modern proximity-ligation assays, like HiChIP and ChIA-PET, facilitate the accurate identification of long-range contacts between enhancers and promoters. However, these assays are technically challenging, expensive, and time-consuming, making it difficult to investigate enhancer topologies, especially in uncharacterized cell types. To overcome these shortcomings, we therefore designed LoopPredictor, an ensemble machine learning model, to predict genome topology for cell types which lack long-range contact maps. To enrich for functional enhancer-promoter loops over common structural genomic contacts, we trained LoopPredictor with both H3K27ac and YY1 HiChIP data. Moreover, the integration of several related multi-omics features facilitated identifying and annotating the predicted loops. LoopPredictor is able to efficiently identify cell type-specific enhancer-mediated loops, and promoter-promoter interactions, with a modest feature input requirement. Comparable to experimentally generated H3K27ac HiChIP data, we found that LoopPredictor was able to identify functional enhancer loops. Furthermore, to explore the cross-species prediction capability of LoopPredictor, we fed mouse multi-omics features into a model trained on human data and found that the predicted enhancer loops outputs were highly conserved. LoopPredictor enables the dissection of cell type-specific long-range gene regulation and can accelerate the identification of distal disease-associated risk variants.
Assuntos
Biologia Computacional/métodos , Elementos Facilitadores Genéticos , Fatores Reguladores de Interferon/genética , Melanoma/genética , Animais , Linhagem Celular Tumoral , Cães , Cavalos , Humanos , Aprendizado de Máquina , Camundongos , Modelos Genéticos , Transplante de Neoplasias , Regiões Promotoras Genéticas , Suínos , Peixe-ZebraRESUMO
BACKGROUND: It is not clear whether conventional vascular risk factors are responsible for most strokes in patients younger than 45 years of age. Our objective was to evaluate the association of common risk factors with stroke in individuals under 45 years. METHODS: INTERSTROKE was a case-control study carried out in 32 countries between 2007 and 2015. Patients presenting within 5 days of symptom onset of a first stroke were enrolled as cases. Controls were age and sex matched to cases and had no history of stroke. Cases and controls underwent similar evaluations. Odds ratios (ORs) and population attributable risks (PARs) were calculated to determine the association of various risk factors with all stroke, ischemic stroke, and intracranial hemorrhage, for patients 45 years of age or younger. FINDINGS: 1,582 case-control pairs were included in this analysis. The mean age of this cohort was 38.5 years (SD 6.32). Overall, 71% strokes were ischemic. Cardiac causes {OR: 8.42 (95% confidence interval [CI]: 3.01-23.5)}; binge drinking of alcohol (OR: 5.44 [95% CI: 1.81-16.4]); hypertension (OR: 5.41 [95% CI: 3.40-8.58]); ApoB/ApoA1 ratio (OR: 2.74 [95% CI: 1.69-4.46]); psychosocial stress (OR: 2.33 [95% CI: 1.01-5.41]); smoking (OR: 1.85 [95% CI: 1.17-2.94]); and increased waist-to-hip ratio (OR: 1.69 [95% CI: 1.04-2.75]) were the most important risk factors for ischemic stroke in these young cases. For intracerebral hemorrhage, only hypertension (OR: 9.08 [95% CI: 5.46-15.1]) and binge drinking (OR: 4.06 [95% CI: 1.27-13.0]) were significant risk factors. The strength of association and population attributable risk (PAR) for hypertension increased with age (PAR 23.3% in those <35 years of age, 50.7% in 35-45 years of age). INTERPRETATION: Conventional risk factors such as hypertension, smoking, binge drinking of alcohol, central obesity, cardiac causes, dyslipidemia, and psychosocial stress are important risk factors for stroke in those younger than 45 years of age. Hypertension is the most significant risk factor in all age groups and across all regions and both stroke subtypes. These risk factors should be identified and modified in early adulthood to prevent strokes in young individuals.
Assuntos
Consumo Excessivo de Bebidas Alcoólicas , Hipertensão , AVC Isquêmico , Acidente Vascular Cerebral , Humanos , Adulto , Pessoa de Meia-Idade , Estudos de Casos e Controles , Consumo Excessivo de Bebidas Alcoólicas/complicações , Acidente Vascular Cerebral/complicações , Fatores de Risco , Hipertensão/epidemiologiaRESUMO
[Figure: see text].