RESUMO
Chronic hepatitis B virus (HBV) infection remains a major global health burden. It affects more than 290 million individuals worldwide and is responsible for approximately 900,000 deaths annually. Anti-HBV treatment with a nucleoside analog in combination with pegylated interferon are considered first-line therapy for patients with chronic HBV infection and liver inflammation. However, because cure rates are low, most patients will require lifetime treatment. HBV Capsid Assembly Modulators (CAMs) have emerged as a promising new class of compounds as they can affect levels of HBV covalently closed-circular DNA (cccDNA) associated with viral persistence. SAR studies around the core structure of lead HBV CAM GLP-26 (Fig. 1B) was performed and led to the discovery of non-toxic compound 10a displaying sub-nanomolar anti-HBV activity. Advanced toxicity and cellular pharmacology profiles of compounds 10a were also established and the results are discussed herein.
Assuntos
Capsídeo , Hepatite B Crônica , Humanos , Vírus da Hepatite B , Hepatite B Crônica/tratamento farmacológico , Antivirais/química , Proteínas do CapsídeoRESUMO
The most recent 2021 IPCC climate science update reminds us yet again that accelerating the transition to a just and resilient zero-carbon future clearly remains humanity's most urgent task. A great deal of hard work and a lot of luck may enable us to avoid some of the most dangerous climate change and ecological tipping points. Current and future generations are however on a journey into a world of more frequent and severe extreme weather events; more heatwaves, fires, floods and famines and more rapid extinctions of animals, birds and insects. Awareness, that this is going to be a very long emergency is a source of deep distress for many people passionately committed to decisive climate action. A rapidly expanding body of research highlights the extent to which this distress is experienced most acutely by children and young people with large numbers reporting deeply pessimistic views about the future. This article explores diverse sources of learning and wisdom - from climate scientists and activists; philosophers and social theorists; Indigenous cultures and ways of life; faith-based and spiritual traditions; artists and writers - which can strengthen our capacity to live courageous, compassionate and creative lives in a world of rapidly accelerating climatic and ecological risk.
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Coragem , Incêndios , Adolescente , Animais , Mudança Climática , Inundações , Previsões , HumanosRESUMO
Cataract, the world-leading cause of blindness, is formed when crystallin aggregates cloud the eye lens. We overexpressed PA28αß, a proteasome activator with properties protective against aggregation and oxidative stress, and examined whether they are less prone to develop cataract arisen from aging and/or hydrogen peroxide (H2O2) treatment. Another objective of this work was to compare the H2O2-induced cataracts of mouse lenses ex vivo to cataracts formed upon aging in mice. As part of an aging study of F2 hybrid C57BL/6NxBALB/c mice, ocular lenses of mature adult (7 months), middle-aged (15 months), and old (22 months of age) PA28αOE mice and their wildtype littermates (n = 22-44 lenses per group) were dissected and evaluated with regard to their cataractous state. In parallel, ocular lenses from 3 to 4 months old PA28αOE and wildtype C57BL/6 N littermates were treated with 100 µM H2O2 every 24 h for 7 days, with progression of cataract and physical appearance monitored daily. Lenses from both studies were also subjected to analysis of oxidative protein damage (carbonylation) and protein solubility. We found that overexpression of PA28αß had no effect on neither age-related nor H2O2-induced cataract and conclude that overexpression of PA28αß does not protect mice from developing cataract. The inefficiency of PA28αß against cataract could be due to its anti-aggregation activity being already excessively present in the eye lens, exerted by crystallins. Crystallins are likely also constituting the 20-25 kDa proteins that were the dominant carbonyl targets in the eye lens irrespective of cataractous state. Assessment of H2O2-induced cataract in relation to age-related cataract demonstrated that high molecular weight protein carbonylation correlates to cataract both in vivo and ex vivo, while reduced protein solubility is more pronounced in age-related cataract. Furthermore, this work highlights vast dissimilarities in the physical manifestations of cataract upon aging and H2O2 ex vivo treatment. Age-related cataract initiation can take various forms, as a vague general blurriness or as a barely visible demarcated opacity, while H2O2-induced cataractogenesis seems to follow a specific scheme. In mice, this scheme begins with relatively opaque peripheral areas emerging that clear up later on as the lenses start to display a hat-like appearance. This transformation takes place synchronous to swelling of the eye lens, and is likely a result of osmotic disturbances causing a phase separation between the viscous lens cortex and the more solid fibers of the lens nucleus.
Assuntos
Envelhecimento , Catarata/induzido quimicamente , Peróxido de Hidrogênio/toxicidade , Cristalino/efeitos dos fármacos , Oxidantes/toxicidade , Complexo de Endopeptidases do Proteassoma/metabolismo , Animais , Western Blotting , Catarata/metabolismo , Catarata/patologia , Quimera , Modelos Animais de Doenças , Feminino , Regulação da Expressão Gênica/fisiologia , Cristalino/metabolismo , Cristalino/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Técnicas de Cultura de Órgãos , Complexo de Endopeptidases do Proteassoma/genética , Carbonilação ProteicaRESUMO
BACKGROUND: The proteasome system plays an important role in synaptic plasticity. Induction and maintenance of long term potentiation is directly dependent on selective targeting of proteins for proteasomal degradation. The 20S proteasome activator PA28αß activates hydrolysis of small nonubiquitinated peptides and possesses protective functions upon oxidative stress and proteinopathy. The effect of PA28αß activity on behavior and memory function is, however, not known. We generated a mouse model that overexpresses PA28α (PA28αOE) to understand PA28αß function during healthy adult homeostasis via assessment of physiological and behavioral profiles, focusing on female mice. RESULTS: PA28α and PA28ß protein levels were markedly increased in all PA28αOE tissues analyzed. PA28αOE displayed reduced depressive-like behavior in the forced swim test and improved memory/learning function assessed by intersession habituation in activity box and shuttle box passive avoidance test, with no significant differences in anxiety or general locomotor activity. Nor were there any differences found when compared to WT for body composition or immuno-profile. The cognitive effects of PA28αOE were female specific, but could not be explained by alterations in estrogen serum levels or hippocampal regulation of estrogen receptor ß. Further, there were no differences in hippocampal protein expression of neuronal or synaptic markers between PA28αOE and WT. Biochemical analysis of hippocampal extracts demonstrated that PA28α overexpression did not increase PA28-20S peptidase activity or decrease K48-polyubiquitin levels. Instead, PA28αOE exhibited elevated efficiency in preventing aggregation in the hippocampus. CONCLUSIONS: This study reveals, for the first time, a connection between PA28αß and neuronal function. We found that PA28α overexpressing female mice displayed reduced depressive-like behavior and enhanced learning and memory. Since the positive effects of PA28α overexpression arose without an activation of 20S proteasome capacity, they are likely independent of PA28αß's role as a 20S proteasome activator and instead depend on a recognized chaperone-like function. These findings suggest that proteostasis in synaptic plasticity is more diverse than previously reported, and demonstrates a novel function of PA28αß in the brain.
Assuntos
Aprendizagem/fisiologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Animais , Depressão/metabolismo , Receptor beta de Estrogênio/metabolismo , Estrogênios/sangue , Feminino , Expressão Gênica , Técnicas de Introdução de Genes , Hipocampo/metabolismo , Homeostase/fisiologia , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Complexo de Endopeptidases do Proteassoma/genéticaRESUMO
BACKGROUND: Oxytocin (Oxt) and its receptor (Oxtr) gene system has been implicated in cardiomyogenesis and cardioprotection; however, effects of chronic activation of Oxtr are not known. We generated and investigated transgenic (TG) mice that overexpress Oxtr specifically in the heart. METHODS AND RESULTS: Cardiac-specific overexpression of Oxtr was obtained by having the α-major histocompatibility complex promoter drive the mouse Oxtr gene (α-Mhc-Oxtr). Left ventricular (LV) function and remodeling were assessed by magnetic resonance imaging and echocardiography. In α-Mhc-Oxtr TG mice, LV ejection fraction was severely compromised at 14 weeks of age compared with wild-type (WT) littermates (25 ± 6% vs 63 ± 3%; P < .001). LV end-diastolic volume was larger in the TG mice (103 ± 6 µL vs 67 ± 5 µL; P < .001). α-Mhc-Oxtr TG animals displayed cardiac fibrosis, atrial thrombus, and increased expression of pro-fibrogenic genes. Mortality of α-Mhc-Oxtr TG animals was 45% compared with 0% (P < .0001) of WT littermates by 20 weeks of age. Most cardiomyocytes of α-Mhc-Oxtr TG animals but not WT littermates (68.0 ± 12.1% vs 5.6 ± 2.4%; P = .008) were positive in staining for nuclear factor of activated T cells (NFAT). To study if thrombin inhibitor prevents thrombus formation, a cohort of 7-week-old α-Mhc-Oxtr TG mice were treated for 12 weeks with AZD0837, a potent thrombin inhibitor. Treatment with AZD0837 reduced thrombus formation (P < .05) and tended to attenuate fibrosis and increase survival. CONCLUSIONS: Cardiac-specific overexpression of Oxtr had negative consequences on LV function and survival in mice. The present findings necessitate further studies to investigate potential adverse effects of chronic Oxt administration. We provide a possible mechanism of Oxtr overexpression leading to heart failure by nuclear factor of activated T cell signaling. The recapitulation of human heart failure and the beneficial effects of the antithrombin inhibitor render the α-Mhc-Oxtr TG mice a promising tool in drug discovery for heart failure.
Assuntos
Cardiomiopatias/genética , Regulação da Expressão Gênica , Miocárdio/metabolismo , RNA/genética , Receptores de Ocitocina/genética , Animais , Cardiomiopatias/diagnóstico , Cardiomiopatias/metabolismo , Modelos Animais de Doenças , Ecocardiografia , Imagem Cinética por Ressonância Magnética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Miocárdio/patologia , Reação em Cadeia da Polimerase em Tempo Real , Receptores de Ocitocina/biossínteseRESUMO
Humanized mouse models are important tools in many areas of biological drug development including, within oncology research, the development of antagonistic antibodies that have the potential to block tumor growth by controlling vascularization and are key to the generation of in vivo proof-of-concept efficacy data. However, due to cross reactivity between human antibodies and mouse target such studies regularly require mouse models expressing only the human version of the target molecule. Such humanized knock-in/knock-out, KIKO, models are dependent upon the generation of homozygous mice expressing only the human molecule, compensating for loss of the mouse form. However, KIKO strategies can fail to generate homozygous mice, even though the human form is expressed and the endogenous mouse locus is correctly targeted. A typical strategy for generating KIKO mice is by ATG fusion where the human cDNA is inserted downstream of the endogenous mouse promoter elements. However, when adopting this strategy it is possible that the mouse promoter fails to express the human form in a manner compensating for loss of the mouse form or alternatively the human protein is incompatible in the context of the mouse pathway being investigated. So to understand more around the biology of KIKO models, and to overcome our failure with a number of ATG fusion strategies, we developed a range of humanized models focused on Delta-like 4 (Dll4), a target where we initially failed to generate a humanized model. By adopting a broader biologic strategy, we successfully generated a humanized DLL4 KIKO which led to a greater understanding of critical biological aspects for consideration when developing humanized models.
Assuntos
Antineoplásicos/farmacologia , Peptídeos e Proteínas de Sinalização Intercelular/genética , Camundongos Transgênicos/genética , Proteínas Adaptadoras de Transdução de Sinal , Animais , Anticorpos Monoclonais/farmacologia , Proteínas de Ligação ao Cálcio , Feminino , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/imunologia , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Masculino , Proteínas de Membrana/genética , Camundongos Knockout , Camundongos SCID , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Modern methods of molecular diagnostics and therapy have revolutionized the field of medicine in recent years by providing more precise and effective tools for detecting and treating diseases. This progress includes a growing exploration of the body's secreted vesicles, known as extracellular vesicles (EVs), for both diagnostic and therapeutic purposes. EVs are a heterogeneous population of lipid bilayer vesicles secreted by almost every cell type studied so far. They are detected in body fluids and conditioned culture media from living cells. EVs play a crucial role in communication between cells and organs, both locally and over long distances. They are recognized for their ability to transport endogenous RNA and proteins between cells, including messenger RNA (mRNA), microRNA (miRNA), misfolded neurodegenerative proteins, and several other biomolecules. This review explores the dual utilization of EVs, serving not only for diagnostic purposes but also as a platform for delivering therapeutic molecules to cells and tissues. Through an exploration of their composition, biogenesis, and selective cargo packaging, we elucidate the intricate mechanisms behind RNA transport between cells via EVs, highlighting their potential use for both diagnostic and therapeutic applications. Finally, it addresses challenges and outlines prospective directions for the clinical utilization of EVs.
RESUMO
Heart failure remains a leading cause of mortality. Therapeutic intervention for heart failure would benefit from targeted delivery to the damaged heart tissue. Here, we applied in vivo peptide phage display coupled with high-throughput Next-Generation Sequencing (NGS) and identified peptides specifically targeting damaged cardiac tissue. We established a bioinformatics pipeline for the identification of cardiac targeting peptides. Hit peptides demonstrated preferential uptake by human induced pluripotent stem cell (iPSC)-derived cardiomyocytes and immortalized mouse HL1 cardiomyocytes, without substantial uptake in human liver HepG2 cells. These novel peptides hold promise for use in targeted drug delivery and regenerative strategies and open new avenues in cardiovascular research and clinical practice.
Assuntos
Células-Tronco Pluripotentes Induzidas , Miócitos Cardíacos , Peptídeos , Humanos , Animais , Camundongos , Miócitos Cardíacos/metabolismo , Peptídeos/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Células-Tronco Pluripotentes Induzidas/citologia , Biblioteca de Peptídeos , Células Hep G2 , Técnicas de Visualização da Superfície Celular/métodos , Sistemas de Liberação de Medicamentos , Sequenciamento de Nucleotídeos em Larga Escala , Insuficiência Cardíaca/metabolismo , Insuficiência Cardíaca/terapiaRESUMO
Efficient and targeted delivery of therapeutic agents remains a bottleneck in modern medicine. Here, biochemical engineering approaches to advance the repurposing of extracellular vesicles (EVs) as drug delivery vehicles are explored. Targeting ligands such as the sugar GalNAc are displayed on the surface of EVs using a HaloTag-fused to a protein anchor that is enriched on engineered EVs. These EVs are successfully targeted to human primary hepatocytes. In addition, the authors are able to decorate EVs with an antibody that recognizes a GLP1 cell surface receptor by using an Fc and Fab region binding moiety fused to an anchor protein, and they show that this improves EV targeting to cells that overexpress the receptor. The authors also use two different protein-engineering approaches to improve the loading of Cre recombinase into the EV lumen and demonstrate that functional Cre protein is delivered into cells in the presence of chloroquine, an endosomal escape enhancer. Lastly, engineered EVs are well tolerated upon intravenous injection into mice without detectable signs of liver toxicity. Collectively, the data show that EVs can be engineered to improve cargo loading and specific cell targeting, which will aid their transformation into tailored drug delivery vehicles.
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Vesículas Extracelulares , Camundongos , Animais , Humanos , Ligantes , Vesículas Extracelulares/metabolismo , Proteínas/metabolismo , Sistemas de Liberação de Medicamentos , Comunicação CelularRESUMO
Lipid nanoparticles (LNPs) are currently used to transport functional mRNAs, such as COVID-19 mRNA vaccines. The delivery of angiogenic molecules, such as therapeutic VEGF-A mRNA, to ischemic tissues for producing new blood vessels is an emerging strategy for the treatment of cardiovascular diseases. Here, the authors deliver VEGF-A mRNA via LNPs and study stoichiometric quantification of their uptake kinetics and how the transport of exogenous LNP-mRNAs between cells is functionally extended by cells' own vehicles called extracellular vesicles (EVs). The results show that cellular uptake of LNPs and their mRNA molecules occurs quickly, and that the translation of exogenously delivered mRNA begins immediately. Following the VEGF-A mRNA delivery to cells via LNPs, a fraction of internalized VEGF-A mRNA is secreted via EVs. The overexpressed VEGF-A mRNA is detected in EVs secreted from three different cell types. Additionally, RNA-Seq analysis reveals that as cells' response to LNP-VEGF-A mRNA treatment, several overexpressed proangiogenic transcripts are packaged into EVs. EVs are further deployed to deliver VEGF-A mRNA in vitro and in vivo. Upon equal amount of VEGF-A mRNA delivery via three EV types or LNPs in vitro, EVs from cardiac progenitor cells are the most efficient in promoting angiogenesis per amount of VEGF-A protein produced. Intravenous administration of luciferase mRNA shows that EVs could distribute translatable mRNA to different organs with the highest amounts of luciferase detected in the liver. Direct injections of VEGF-A mRNA (via EVs or LNPs) into mice heart result in locally produced VEGF-A protein without spillover to liver and circulation. In addition, EVs from cardiac progenitor cells cause minimal production of inflammatory cytokines in cardiac tissue compared with all other treatment types. Collectively, the data demonstrate that LNPs transform EVs as functional extensions to distribute therapeutic mRNA between cells, where EVs deliver this mRNA differently than LNPs.
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COVID-19 , Vesículas Extracelulares , Camundongos , Animais , RNA Mensageiro/metabolismo , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo , COVID-19/metabolismo , Vesículas Extracelulares/metabolismoRESUMO
With age, protein damage accumulates and increases the risk of age-related diseases. The proteasome activator PA28αß is involved in protein damage clearance during early embryogenesis and has demonstrated protective effects against proteinopathy. We have recently discovered that adult female mice overexpressing PA28α (PA28αOE) have enhanced learning and memory, and protein extracts from their hippocampi prevent aggregation more efficiently than wild type. In this study, we investigated the effect of overexpressing PA28α on aging using C57BL/6N×BALB/c F2 hybrid mice. We found that the hippocampal anti-aggregation effect was maintained in young adult (7 months) to middle-aged (15 months) and old (22 months) PA28αOE females. While the PA28αOE influence on learning and memory gradually decreased with aging, old PA28αOE females did not display the typical drop in explorative behavior-a behavioral hallmark of aging-but were as explorative as young mice. PA28αOE lowered PA28-dependent proteasome capacity in both heart and hippocampus, and there was no indication of lower protein damage load in PA28αOE. The life span of PA28αOE was also similar to wild type. In both wild type and PA28αOE, PA28-dependent proteasome capacity increased with aging in the heart, while 26S and 20S proteasome capacities were unchanged in the timepoints analyzed. Thus, PA28αOE females exhibit improved hippocampal ability to prevent aggregation throughout life and enhanced cognitive capabilities with different behavioral outcomes dependent on age; improved memory at early age and a youth-like exploration at old age. The cognitive effects of PA28αß combined with its anti-aggregation molecular effect highlight the therapeutical potential of PA28αß in combating proteinopathies.
Assuntos
Envelhecimento/metabolismo , Comportamento Exploratório , Hipocampo/metabolismo , Complexo de Endopeptidases do Proteassoma/genética , Complexo de Endopeptidases do Proteassoma/metabolismo , Agregados Proteicos/genética , Transdução de Sinais/genética , Envelhecimento/genética , Animais , Quimera , Cognição , Feminino , Técnicas de Introdução de Genes/métodos , Memória , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Miocárdio/metabolismoRESUMO
Endothelial integrity is vital for homeostasis and adjusted to tissue demands. Although fluid uptake by lymphatic capillaries is a critical attribute of the lymphatic vasculature, the barrier function of collecting lymphatic vessels is also important by ensuring efficient fluid drainage as well as lymph node delivery of antigens and immune cells. Here, we identified the transmembrane ligand EphrinB2 and its receptor EphB4 as critical homeostatic regulators of collecting lymphatic vessel integrity. Conditional gene deletion in mice revealed that EphrinB2/EphB4 signalling is dispensable for blood endothelial barrier function, but required for stabilization of lymphatic endothelial cell (LEC) junctions in different organs of juvenile and adult mice. Studies in primary human LECs further showed that basal EphrinB2/EphB4 signalling controls junctional localisation of the tight junction protein CLDN5 and junction stability via Rac1/Rho-mediated regulation of cytoskeletal contractility. EphrinB2/EphB4 signalling therefore provides a potential therapeutic target to selectively modulate lymphatic vessel permeability and function.
Lymph vessels are thin walled tubes that, similar to blood vessels, carry white blood cells, fluids and waste. Unlike veins and arteries, however, lymph vessels do not carry red blood cells and their main function is to remove excess fluid from tissues. The cells that line vessels in the body are called endothelial cells, and they are tightly linked together by proteins to control what goes into and comes out of the vessels. The chemical, physical and mechanical signals that control the junctions between endothelial cells are often the same in different vessel types, but their effects can vary. The endothelial cells of both blood and lymph vessels have two interacting proteins on their membrane known as EphrinB2 and its receptor, EphB4. When these two proteins interact, the EphB4 receptor becomes activated, which leads to changes in the junctions that link endothelial cells together. Frye et al. examined the role of EphrinB2 and EphB4 in the lymphatic system of mice. When either EphrinB2 or EphB4 are genetically removed in newborn or adult mice, lymph vessels become disrupted, but no significant effect is observed on blood vessels. The reason for the different responses in blood and lymph vessels is unknown. The results further showed that lymphatic endothelial cells need EphB4 and EphrinB2 to be constantly interacting to maintain the integrity of the lymph vessels. Further examination of human endothelial cells grown in the laboratory revealed that this constant signalling controls the internal protein scaffold that determines a cell's shape and integrity. Changes in the internal scaffold affect the organization of the junctions that link neighboring lymphatic endothelial cells together. The loss of signalling between EphrinB2 and EphB4 in lymph vessels reflects the increase in vessel leakage seen in response to bacterial infections and in some genetic conditions such as lymphoedema. Finding ways to control the signalling between these two proteins could help treat these conditions by developing drugs that improve endothelial cell integrity in lymph vessels.
Assuntos
Células Endoteliais/metabolismo , Efrina-B2/genética , Homeostase , Junções Intercelulares/metabolismo , Vasos Linfáticos/fisiologia , Receptor EphB4/genética , Transdução de Sinais , Animais , Claudina-5/genética , Efrina-B2/metabolismo , Deleção de Genes , Camundongos , Receptor EphB4/metabolismoRESUMO
GPR81 (G-protein-coupled receptor 81) is highly expressed in adipocytes, and activation by the endogenous ligand lactate inhibits lipolysis. GPR81 is also expressed in the heart, liver, and kidney, but roles in nonadipose tissues are poorly defined. GPR81 agonists, developed to improve blood lipid profile, might also provide insights into GPR81 physiology. Here, we assessed the blood pressure and renal hemodynamic responses to the GPR81 agonist, AZ'5538. In male wild-type mice, intravenous AZ'5538 infusion caused a rapid and sustained increase in systolic and diastolic blood pressure. Renal artery blood flow, intrarenal tissue perfusion, and glomerular filtration rate were all significantly reduced. AZ'5538 had no effect on blood pressure or renal hemodynamics in Gpr81-/- mice. Gpr81 mRNA was expressed in renal artery vascular smooth muscle, in the afferent arteriole, in glomerular and medullary perivascular cells, and in pericyte-like cells isolated from kidney. Intravenous AZ'5538 increased plasma ET-1 (endothelin 1), and pretreatment with BQ123 (endothelin-A receptor antagonist) prevented the pressor effects of GPR81 activation, whereas BQ788 (endothelin-B receptor antagonist) did not. Renal ischemia-reperfusion injury, which increases renal extracellular lactate, increased the renal expression of genes encoding ET-1, KIM-1 (Kidney Injury Molecule 1), collagen type 1-α1, TNF-α (tumor necrosis factor-α), and F4/80 in wild-type mice but not in Gpr81-/- mice. In summary, activation of GPR81 in vascular smooth muscle and perivascular cells regulates renal hemodynamics, mediated by release of the potent vasoconstrictor ET-1. This suggests that lactate may be a paracrine regulator of renal blood flow, particularly relevant when extracellular lactate is high as occurs during ischemic renal disease.
Assuntos
Endotelina-1/fisiologia , Hemodinâmica/efeitos dos fármacos , Receptores Acoplados a Proteínas G/agonistas , Animais , Artérias/efeitos dos fármacos , Pressão Sanguínea/efeitos dos fármacos , Pressão Sanguínea/fisiologia , Bosentana/farmacologia , Endotelina-1/sangue , Taxa de Filtração Glomerular/efeitos dos fármacos , Coração/efeitos dos fármacos , Hemodinâmica/fisiologia , Infusões Intravenosas , Rim/irrigação sanguínea , Rim/efeitos dos fármacos , Lactatos/sangue , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/metabolismo , Oligopeptídeos/farmacologia , Comunicação Parácrina , Peptídeos Cíclicos/farmacologia , Pericitos/efeitos dos fármacos , Pericitos/metabolismo , Piperidinas/farmacologia , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Receptores Acoplados a Proteínas G/deficiência , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/fisiologia , Circulação Renal/efeitos dos fármacos , Circulação Renal/fisiologia , Traumatismo por Reperfusão/sangue , Traumatismo por Reperfusão/tratamento farmacológico , Traumatismo por Reperfusão/genética , Traumatismo por Reperfusão/fisiopatologiaRESUMO
Due to strain-specific behavioral idiosyncrasies, inbred mouse strains are suboptimal research models for behavioral aging studies. The aim of this study is to determine age-related behavioral changes of F2 hybrid C57BL/6NxBALB/c male and female mice. Lifespan was followed (nmales=48, nfemales=51) and cohorts of mature adult (7 months), middle-aged (15 months), and old mice (22 months of age; n=7-12 per group) were assessed regarding open-field activity, exploration, passive avoidance learning/memory, and depressive-like behavior. We found that both males and females demonstrated decreased exploratory behavior with age, while memory and depressive-like behavior were maintained. Females exhibited enhanced depressive-like behavior compared to males; however, a correlation between fat mass and swimming activity in the test directly accounted for 30-46% of this behavioral sex difference. In addition, we suggest a method to qualitatively estimate natural lifespan from survival analyses in which animals with signs of pain or severe disease are euthanized. This is, to our knowledge, the first behavioral study to consider both sex and aging in hybrid mice. We here define decreased exploratory behavior as a conserved hallmark of aging independent of sex, highlight the effect of buoyancy in water tests, and provide a method to assay lifespan with reduced animal suffering.
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Envelhecimento/psicologia , Natação/psicologia , Adiposidade , Envelhecimento/fisiologia , Animais , Comportamento Exploratório , Feminino , Masculino , Memória , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Natação/fisiologiaRESUMO
The homeostasis of heart and other organs relies on the appropriate provision of nutrients and functional specialization of the local vasculature. Here, we have used mouse genetics, imaging and cell biology approaches to investigate how homeostasis in the adult heart is controlled by endothelial EphB4 and its ligand ephrin-B2, which are known regulators of vascular morphogenesis and arteriovenous differentiation during development. We show that inducible and endothelial cell-specific inactivation of Ephb4 in adult mice is compatible with survival, but leads to rupturing of cardiac capillaries, cardiomyocyte hypertrophy, and pathological cardiac remodeling. In contrast, EphB4 is not required for integrity and homeostasis of capillaries in skeletal muscle. Our analysis of mutant mice and cultured endothelial cells shows that EphB4 controls the function of caveolae, cell-cell adhesion under mechanical stress and lipid transport. We propose that EphB4 maintains critical functional properties of the adult cardiac vasculature and thereby prevents dilated cardiomyopathy-like defects.
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Endotélio Vascular/crescimento & desenvolvimento , Efrina-B2/genética , Coração/crescimento & desenvolvimento , Receptor EphB4/genética , Adulto , Animais , Adesão Celular/genética , Diferenciação Celular/genética , Desenvolvimento Embrionário/genética , Células Endoteliais/metabolismo , Endotélio Vascular/metabolismo , Homeostase/genética , Humanos , Ligantes , Camundongos , Morfogênese/genética , Músculo Esquelético/crescimento & desenvolvimento , Neovascularização Fisiológica/genéticaRESUMO
This essay explores the changing nature of the concept of community wellbeing and the richness of the concept for enhancing measurement of societal progress beyond the use of indicators focused more narrowly on economic growth. Beginning with the history of the concept of wellbeing in several disciplines, the authors pursue an integrated and ecological understanding of community wellbeing and present examples of recent developments and applications of community wellbeing indicators in international settings and in Australia.
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Meio Ambiente , Nível de Saúde , Saúde Pública/tendências , Características de Residência , Austrália , Humanos , Saúde Mental , Fatores SocioeconômicosRESUMO
A complex, whole-of-economy issue such as climate change demands an interdisciplinary, multi-sectoral response. However, evidence suggests that human health has remained elusive in its influence on the development of ambitious climate change mitigation policies for many national governments, despite a recognition that the combustion of fossil fuels results in pervasive short- and long-term health consequences. We use insights from literature on the political economy of health and climate change, the science–policy interface and power in policy-making, to identify additional barriers to the meaningful incorporation of health co-benefits into climate change mitigation policy development. Specifically, we identify four key interrelated areas where barriers may exist in relation to health co-benefits: discourse, efficiency, vested interests and structural challenges. With these insights in mind, we argue that the current politico-economic paradigm in which climate change is situated and the processes used to develop climate change mitigation policies do not adequately support accounting for health co-benefits. We present approaches for enhancing the role of health co-benefits in the development of climate change mitigation policies to ensure that health is embedded in the broader climate change agenda.
Assuntos
Mudança Climática/economia , Atenção à Saúde/economia , Atenção à Saúde/legislação & jurisprudência , Política de Saúde/economia , Política de Saúde/legislação & jurisprudência , Política , HumanosRESUMO
α1-antitrypsin (AAT) is a circulating serine protease inhibitor secreted from the liver and important in preventing proteolytic neutrophil elastase associated tissue damage, primarily in lungs. In humans, AAT is encoded by the SERPINA1 (hSERPINA1) gene in which a point mutation (commonly referred to as PiZ) causes aggregation of the miss-folded protein in hepatocytes resulting in subsequent liver damage. In an attempt to rescue the pathologic liver phenotype of a mouse model of human AAT deficiency (AATD), we used adenovirus to deliver Cas9 and a guide-RNA (gRNA) molecule targeting hSERPINA1. Our single dose therapeutic gene editing approach completely reverted the phenotype associated with the PiZ mutation, including circulating transaminase and human AAT (hAAT) protein levels, liver fibrosis and protein aggregation. Furthermore, liver histology was significantly improved regarding inflammation and overall morphology in hSERPINA1 gene edited PiZ mice. Genomic analysis confirmed significant disruption to the hSERPINA1 transgene resulting in a reduction of hAAT protein levels and quantitative mRNA analysis showed a reduction in fibrosis and hepatocyte proliferation as a result of editing. Our findings indicate that therapeutic gene editing in hepatocytes is possible in an AATD mouse model.
Assuntos
Sistemas CRISPR-Cas , Edição de Genes , Fenótipo , Deficiência de alfa 1-Antitripsina/genética , Deficiência de alfa 1-Antitripsina/metabolismo , alfa 1-Antitripsina/genética , Adenoviridae/genética , Animais , Proliferação de Células , Modelos Animais de Doenças , Expressão Gênica , Vetores Genéticos/genética , Humanos , Camundongos , Camundongos Transgênicos , Transdução Genética , Transgenes , alfa 1-Antitripsina/sangue , alfa 1-Antitripsina/metabolismo , Deficiência de alfa 1-Antitripsina/patologia , Deficiência de alfa 1-Antitripsina/terapiaRESUMO
ISSUE ADDRESSED: The development of an integrated set of mental health promotion indicators at individual, organisational and community levels. DISCUSSION: There is increasing recognition that the implementation of effective and sustainable strategies for the promotion of mental health and well-being requires the development of indicators to support priority setting, establishing targets and measuring progress. This article aims to contribute to this task by bringing together recent work on individual, organisational and community indicators that shows progress in the promotion of mental health and well-being. CONCLUSIONS: An initial set of indicators is proposed, informed by current knowledge from research and practice settings.
Assuntos
Promoção da Saúde/organização & administração , Saúde Mental , Política Organizacional , Características de Residência , Autoimagem , Indicadores Básicos de Saúde , Humanos , Fatores SocioeconômicosRESUMO
GPR81 is a receptor for the metabolic intermediate lactate with an established role in regulating adipocyte lipolysis. Potentially novel GPR81 agonists were identified that suppressed fasting plasma free fatty acid levels in rodents and in addition improved insulin sensitivity in mouse models of insulin resistance and diabetes. Unexpectedly, the agonists simultaneously induced hypertension in rodents, including wild-type, but not GPR81-deficient mice. Detailed cardiovascular studies in anesthetized dogs showed that the pressor effect was associated with heterogenous effects on vascular resistance among the measured tissues: increasing in the kidney while remaining unchanged in hindlimb and heart. Studies in rats revealed that the pressor effect could be blocked, and the renal resistance effect at least partially blocked, with pharmacological antagonism of endothelin receptors. In situ hybridization localized GPR81 to the microcirculation, notably afferent arterioles of the kidney. In conclusion, these results provide evidence for a potentially novel role of GPR81 agonism in blood pressure control and regulation of renal vascular resistance including modulation of a known vasoeffector mechanism, the endothelin system. In addition, support is provided for the concept of fatty acid lowering as a means of improving insulin sensitivity.