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1.
Genes Dev ; 33(23-24): 1739-1750, 2019 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-31753914

RESUMO

Proliferating cells, typically considered "nonexcitable," nevertheless, exhibit regulation by bioelectric signals. Notably, voltage-gated sodium channels (VGSC) that are crucial for neuronal excitability are also found in progenitors and up-regulated in cancer. Here, we identify a role for VGSC in proliferation of Drosophila neuroblast (NB) lineages within the central nervous system. Loss of paralytic (para), the sole gene that encodes Drosophila VGSC, reduces neuroblast progeny cell number. The type II neuroblast lineages, featuring a population of transit-amplifying intermediate neural progenitors (INP) similar to that found in the developing human cortex, are particularly sensitive to para manipulation. Following a series of asymmetric divisions, INPs normally exit the cell cycle through a final symmetric division. Our data suggests that loss of Para induces apoptosis in this population, whereas overexpression leads to an increase in INPs and overall neuroblast progeny cell numbers. These effects are cell autonomous and depend on Para channel activity. Reduction of Para expression not only affects normal NB development, but also strongly suppresses brain tumor mass, implicating a role for Para in cancer progression. To our knowledge, our studies are the first to identify a role for VGSC in neural progenitor proliferation. Elucidating the contribution of VGSC in proliferation will advance our understanding of bioelectric signaling within development and disease states.


Assuntos
Proliferação de Células/genética , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila/citologia , Drosophila/genética , Células-Tronco Neurais/citologia , Canais de Sódio/genética , Canais de Sódio/metabolismo , Animais , Apoptose , Contagem de Células , Linhagem da Célula/genética , Expressão Gênica , Técnicas de Silenciamento de Genes
2.
Eur J Immunol ; 54(7): e2451028, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38616772

RESUMO

Vitamin C (ascorbic acid) is a potent antioxidant and a cofactor for various enzymes including histone demethylases and methylcytosine dioxygenases. Vitamin C also exerts direct cytotoxicity toward selected tumor cells including colorectal carcinoma. Moreover, vitamin C has been shown to impact immune cell differentiation at various levels including maturation and/or functionality of T cells and their progenitors, dendritic cells, B cells, and NK cells. γδ T cells have recently attracted great interest as effector cells for cell-based cancer immunotherapy, due to their HLA-independent recognition of a large variety of tumor cells. While γδ T cells can thus be also applied as an allogeneic off-the-shelf product, it is obvious that the effector function of γδ T cells needs to be optimized to ensure the best possible clinical efficacy. Here we review the immunomodulatory mechanisms of vitamin C with a special focus on how vitamin C enhances the effector function of γδ T cells. We also discuss future directions of how vitamin C can be used in the clinical setting to boost the efficacy of adoptive cell therapies.


Assuntos
Ácido Ascórbico , Receptores de Antígenos de Linfócitos T gama-delta , Ácido Ascórbico/farmacologia , Humanos , Receptores de Antígenos de Linfócitos T gama-delta/imunologia , Receptores de Antígenos de Linfócitos T gama-delta/metabolismo , Animais , Imunoterapia Adotiva/métodos , Linfócitos T/imunologia , Neoplasias/imunologia , Neoplasias/terapia , Neoplasias/tratamento farmacológico , Diferenciação Celular/imunologia , Diferenciação Celular/efeitos dos fármacos
3.
Blood ; 139(1): 104-117, 2022 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-34329392

RESUMO

Tyrosine phosphorylation of extracellular proteins is observed in cell cultures and in vivo, but little is known about the functional roles of tyrosine phosphorylation of extracellular proteins. Vertebrate lonesome kinase (VLK) is a broadly expressed secretory pathway tyrosine kinase present in platelet α-granules. It is released from platelets upon activation and phosphorylates substrates extracellularly. Its role in platelet function, however, has not been previously studied. In human platelets, we identified phosphorylated tyrosines mapped to luminal or extracellular domains of transmembrane and secreted proteins implicated in the regulation of platelet activation. To determine the role of VLK in extracellular tyrosine phosphorylation and platelet function, we generated mice with a megakaryocyte/platelet-specific deficiency of VLK. Platelets from these mice are normal in abundance and morphology but have significant changes in function both in vitro and in vivo. Resting and thrombin-stimulated VLK-deficient platelets exhibit a significant decrease in several tyrosine phosphobands. Results of functional testing of VLK-deficient platelets show decreased protease-activated receptor 4-mediated and collagen-mediated platelet aggregation but normal responses to adenosine 5'-diphosphate. Dense granule and α-granule release are reduced in these platelets. Furthermore, VLK-deficient platelets exhibit decreased protease-activated receptor 4-mediated Akt (S473) and Erk1/2 (T202/Y204) phosphorylation, indicating altered proximal signaling. In vivo, mice lacking VLK in megakaryocytes/platelets display strongly reduced platelet accumulation and fibrin formation after laser-induced injury of cremaster arterioles compared with control mice but with normal bleeding times. These studies show that the secretory pathway tyrosine kinase VLK is critical for stimulus-dependent platelet activation and thrombus formation, providing the first evidence that a secreted protein kinase is required for normal platelet function.


Assuntos
Plaquetas/metabolismo , Ativação Plaquetária , Proteínas Tirosina Quinases/metabolismo , Trombose/metabolismo , Animais , Plaquetas/patologia , Deleção de Genes , Células HEK293 , Humanos , Camundongos Transgênicos , Proteínas Tirosina Quinases/genética , Trombose/patologia
4.
Nephrol Dial Transplant ; 38(10): 2131-2142, 2023 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-36460034

RESUMO

BACKGROUND: Vitamin K deficiency is highly prevalent in patients on dialysis and may contribute to their low bone mineral density (BMD) and increased risk of fracture. This study investigated the effect of menaquinone-7 (MK-7) supplementation on BMD in patients on chronic dialysis. METHODS: In a multicentre, double-blind, placebo-controlled intervention trial, 123 patients on chronic dialysis were randomised to a daily oral supplement of either MK-7 360 µg or placebo for 2 years. BMD of the distal radius (1/3, mid, ultradistal and total), femoral neck, lumbar spine (L1-L4) and whole body was assessed by dual-energy X-ray absorptiometry. Serum levels of vitamin K1 and MK-7 and plasma levels of total osteocalcin, dephosphorylated-uncarboxylated matrix Gla protein and protein induced by vitamin K absence II were measured to assess vitamin K status. RESULTS: After 2 years, an accelerated BMD loss of the 1/3 distal radius was found with MK-7 supplementation {mean difference of changes relative to placebo -0.023 g/cm2 [95% confidence interval (CI) -0.039 to -0.008]}, whereas the decrease in lumbar spine BMD seen in the placebo group was prevented [mean difference of changes between groups 0.050 g/cm2 (95% CI 0.015-0.085)]. No significant effects were observed at the remaining skeletal sites. Vitamin K status strongly improved in MK-7-supplemented participants. CONCLUSION: Compared with placebo, an accelerated BMD loss of the 1/3 distal radius was found after 2 years of MK-7 supplementation, whereas a decline in lumbar spine BMD was prevented. As such, MK-7 supplementation might modify BMD site-specifically in patients on dialysis. In aggregate, our findings do not support MK-7 supplementation to preserve bone in patients on dialysis.


Assuntos
Densidade Óssea , Vitamina K , Humanos , Diálise Renal/efeitos adversos , Absorciometria de Fóton , Vitamina K 2/farmacologia , Vitamina K 2/uso terapêutico , Suplementos Nutricionais , Método Duplo-Cego
5.
Nature ; 552(7685): 426-429, 2017 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-29236684

RESUMO

Calcium-activated chloride channels (CaCCs) encoded by TMEM16A control neuronal signalling, smooth muscle contraction, airway and exocrine gland secretion, and rhythmic movements of the gastrointestinal system. To understand how CaCCs mediate and control anion permeation to fulfil these physiological functions, knowledge of the mammalian TMEM16A structure and identification of its pore-lining residues are essential. TMEM16A forms a dimer with two pores. Previous CaCC structural analyses have relied on homology modelling of a homologue (nhTMEM16) from the fungus Nectria haematococca that functions primarily as a lipid scramblase, as well as subnanometre-resolution electron cryo-microscopy. Here we present de novo atomic structures of the transmembrane domains of mouse TMEM16A in nanodiscs and in lauryl maltose neopentyl glycol as determined by single-particle electron cryo-microscopy. These structures reveal the ion permeation pore and represent different functional states. The structure in lauryl maltose neopentyl glycol has one Ca2+ ion resolved within each monomer with a constricted pore; this is likely to correspond to a closed state, because a CaCC with a single Ca2+ occupancy requires membrane depolarization in order to open (C.J.P. et al., manuscript submitted). The structure in nanodiscs has two Ca2+ ions per monomer and its pore is in a closed conformation; this probably reflects channel rundown, which is the gradual loss of channel activity that follows prolonged CaCC activation in 1 mM Ca2+. Our mutagenesis and electrophysiological studies, prompted by analyses of the structures, identified ten residues distributed along the pore that interact with permeant anions and affect anion selectivity, as well as seven pore-lining residues that cluster near pore constrictions and regulate channel gating. Together, these results clarify the basis of CaCC anion conduction.


Assuntos
Anoctamina-1/química , Anoctamina-1/ultraestrutura , Cálcio/química , Cálcio/farmacologia , Microscopia Crioeletrônica , Ativação do Canal Iônico/efeitos dos fármacos , Animais , Ânions/química , Ânions/metabolismo , Anoctamina-1/metabolismo , Cálcio/metabolismo , Glucosídeos/química , Células HEK293 , Humanos , Transporte de Íons/efeitos dos fármacos , Camundongos , Modelos Moleculares , Nanoestruturas/química , Nanoestruturas/ultraestrutura , Conformação Proteica/efeitos dos fármacos
6.
Environ Sci Technol ; 56(10): 6678-6688, 2022 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-35475365

RESUMO

Osmotically assisted reverse osmosis (OARO) has shown great potential for low-cost and energy-efficient brine management. However, its performance can be significantly limited by membrane fouling. Here, we performed for the first time a comprehensive study on OARO membrane fouling, explored the associated fouling mechanisms, and evaluated fouling reversibility via simple physical cleaning strategies. First, internal membrane fouling at the draw (permeate) side was shown to be insignificant. Flux behavior in short-term operation was correlated to both the evolution of fouling and the change of internal concentration polarization. In long-term operation, membrane fouling constrained the OARO water flux to a singular, common upper limit, in terms of limiting flux, which was demonstrated to be independent of operating pressures and membrane properties. Generally, once the limiting flux was exceeded, the OARO process performance could not be improved by higher-pressure operation or by utilizing more permeable and selective membranes. Instead, different cyclic cleaning strategies were shown to be more promising alternatives for improving performance. While both surface flushing and osmotic backwashing (OB) were found to be highly effective when using pure water, a full flux recovery could not be achieved when a nonpure solution was used during OB due to severe internal clogging during OB. All in all, the presented findings provided significant implications for OARO operation and fouling control.


Assuntos
Membranas Artificiais , Purificação da Água , Filtração , Osmose , Água
7.
Semin Dial ; 35(6): 463-480, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35623902

RESUMO

Non-vitamin K oral anticoagulants (NOACs) are used for prevention of thromboembolic events, but their use in dialysis patients is debatable. This study investigated the available evidence for the use of NOACs in dialysis patients. Online databases were systematically searched for eligible studies including pharmacokinetic (PK) studies, cohort studies, and randomized control trials (RCTs) comparing NOAC with vitamin K antagonist (VKA) or no anticoagulant treatment. Newcastle Ottawa Scale and Cochrane Risk of bias tool were used for quality assessment. Twenty studies were identified (nine PK studies, two RCTs, and nine cohort studies). Most of the studies investigated apixaban or rivaroxaban. In dialysis patients, less accumulation was reported with apixaban and rivaroxaban compared to dabigatran and edoxaban. PK studies indicate that high dose apixaban or rivaroxaban should be avoided. The two RCTs (rivaroxaban/apixaban vs. VKA) were small and underpowered regarding stroke and bleeding outcomes. Most cohort studies found apixaban superior to VKA, whereas comparison of rivaroxaban with VKA yielded conflicting results. Cohort studies comparing apixaban high dose (5 mg) with low dose (2.5 mg) twice daily suggest a lower risk of stroke with high dose but also a higher risk of bleeding with high dose. Apixaban versus no anticoagulation was compared in one cohort study and did not lower the risk of stroke compared with non-treated regardless of apixaban dosage. Widespread use of NOACs in dialysis patients is limited by adequately sized RCTs. Available evidence suggests a potential for use of apixaban and rivaroxaban in reduced dose.


Assuntos
Fibrilação Atrial , Acidente Vascular Cerebral , Humanos , Vitamina K/uso terapêutico , Rivaroxabana/efeitos adversos , Administração Oral , Diálise Renal/efeitos adversos , Anticoagulantes/uso terapêutico , Dabigatrana/efeitos adversos , Acidente Vascular Cerebral/tratamento farmacológico , Hemorragia/induzido quimicamente , Fibrilação Atrial/tratamento farmacológico
8.
Proc Natl Acad Sci U S A ; 116(26): 13026-13035, 2019 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-31182586

RESUMO

Pancreatic cancer typically spreads rapidly and has poor survival rates. Here, we report that the calcium-activated chloride channel TMEM16A is a biomarker for pancreatic cancer with a poor prognosis. TMEM16A is up-regulated in 75% of cases of pancreatic cancer and high levels of TMEM16A expression are correlated with low patient survival probability. TMEM16A up-regulation is associated with the ligand-dependent EGFR signaling pathway. In vitro, TMEM16A is required for EGF-induced store-operated calcium entry essential for pancreatic cancer cell migration. TMEM16A also has a profound impact on phosphoproteome remodeling upon EGF stimulation. Moreover, molecular actors identified in this TMEM16A-dependent EGFR-induced calcium signaling pathway form a gene set that makes it possible not only to distinguish neuro-endocrine tumors from other forms of pancreatic cancer, but also to subdivide the latter into three clusters with distinct genetic profiles that could reflect their molecular underpinning.


Assuntos
Anoctamina-1/metabolismo , Biomarcadores Tumorais/metabolismo , Sinalização do Cálcio , Carcinoma Ductal Pancreático/patologia , Fator de Crescimento Epidérmico/metabolismo , Proteínas de Neoplasias/metabolismo , Neoplasias Pancreáticas/patologia , Anoctamina-1/genética , Carcinoma Ductal Pancreático/diagnóstico , Carcinoma Ductal Pancreático/mortalidade , Linhagem Celular Tumoral , Movimento Celular , Conjuntos de Dados como Assunto , Diagnóstico Diferencial , Receptores ErbB/metabolismo , Células HEK293 , Humanos , Proteínas de Neoplasias/genética , Pâncreas/patologia , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/mortalidade , Prognóstico , RNA Interferente Pequeno/metabolismo , RNA-Seq , Taxa de Sobrevida , Regulação para Cima
9.
J Neurosci ; 40(46): 8870-8882, 2020 11 11.
Artigo em Inglês | MEDLINE | ID: mdl-33051345

RESUMO

The emergence of genetic tools has provided new means of mapping functionality in central amygdala (CeA) neuron populations based on their molecular profiles, response properties, and importantly, connectivity patterns. While abundant evidence indicates that neuronal signals arrive in the CeA eliciting both aversive and appetitive behaviors, our understanding of the anatomy of the underlying long-range CeA network remains fragmentary. In this study, we combine viral tracings, electrophysiological, and optogenetic approaches to establish in male mice, a wiring chart between the insula cortex (IC), a major sensory input region of the lateral and capsular part of the CeA (CeL/C), and four principal output streams of this nucleus. We found that retrogradely labeled output neurons occupy discrete and likely strategic locations in the CeL/C, and that they are disproportionally controlled by the IC. We identified a direct line of connection between the IC and the lateral hypothalamus (LH), which engages numerous LH-projecting CeL/C cells whose activity can be strongly upregulated on firing of IC neurons. In comparison, CeL/C neurons projecting to the bed nucleus of the stria terminalis (BNST) are also frequently contacted by incoming IC axons, but the strength of this connection is weak. Our results provide a link between long-range inputs and outputs of the CeA and pave the way to a better understanding of how internal, external, and experience dependent information may impinge on action selection by the CeA.SIGNIFICANCE STATEMENT Our current knowledge of the circuit organization within the central amygdala (CeA), a critical regulator of emotional states, includes independent information about its long-range efferents and afferents. We do not know how incoming sensory information is appraised and routed through the CeA to the different output channels. We address this issue by using three different techniques to investigate how a sensory region, the insula cortex (IC), connects with the motor, physiological and autonomic output centers of the CeA. We uncover a strong connection between the IC and the lateral hypothalamus (LH) with a monosynaptic relay in the CeA and shed new light on the previously described functions of IC and CeA through direct projections to the LH.


Assuntos
Núcleo Central da Amígdala/fisiologia , Córtex Cerebral/fisiologia , Animais , Axônios/fisiologia , Fenômenos Eletrofisiológicos , Região Hipotalâmica Lateral/fisiologia , Técnicas In Vitro , Interneurônios/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Vias Neurais/fisiologia , Optogenética , Núcleos Septais/fisiologia
10.
Cell Mol Life Sci ; 77(4): 751-764, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31300870

RESUMO

Dipeptidyl peptidase 4 (DPP4, CD26) is a serine protease detected on several immune cells and on epithelial cells of various organs. Besides the membrane-bound enzyme, a catalytically active soluble form (sCD26/DPP4) is detected in several body fluids. Both variants cleave off dipeptides from the N-termini of various chemokines, neuropeptides, and hormones. CD26/DPP4 plays a fundamental role in the regulation of blood glucose levels by inactivating insulinotropic incretins and CD26/DPP4 inhibitors are thus routinely used in diabetes mellitus type 2 therapy to improve glucose tolerance. Such inhibitors might also prevent the CD26/DPP4-mediated inactivation of the T-cell chemoattractant CXCL10 released by certain tumors and thus improve anti-tumor immunity and immunotherapy. Despite its implication in the regulation of many (patho-)physiological processes and its consideration as a biomarker and therapeutic target, the cellular source of sCD26/DPP4 remains highly debated and mechanisms of its release are so far unknown. In line with recent reports that activated T lymphocytes could be a major source of sCD26/DPP4, we now demonstrate that CD26/DPP4 is stored in secretory granules of several major human cytotoxic lymphocyte populations and co-localizes with effector proteins such as granzymes, perforin, and granulysin. Upon stimulation, vesicular CD26/DPP4 is rapidly translocated to the cell surface in a Ca2+-dependent manner. Importantly, activation-induced degranulation leads to a massive release of proteolytically active sCD26/DPP4. Since activated effector lymphocytes serve as a major source of sCD26/DPP4, these results might explain the observed disease-associated alterations of sCD26/DPP4 serum levels and also indicate a so far unknown role of CD26/DPP4 in lymphocyte-mediated cytotoxicity.


Assuntos
Degranulação Celular , Dipeptidil Peptidase 4/metabolismo , Linfócitos T Citotóxicos/fisiologia , Cálcio/metabolismo , Células Cultivadas , Humanos , Proteólise
11.
Proc Natl Acad Sci U S A ; 115(5): E982-E991, 2018 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-29343648

RESUMO

Stimulation of protease-activated receptor 1 (PAR1) on endothelium by activated protein C (APC) is protective in several animal models of disease, and APC has been used clinically in severe sepsis and wound healing. Clinical use of APC, however, is limited by its immunogenicity and its anticoagulant activity. We show that a class of small molecules termed "parmodulins" that act at the cytosolic face of PAR1 stimulates APC-like cytoprotective signaling in endothelium. Parmodulins block thrombin generation in response to inflammatory mediators and inhibit platelet accumulation on endothelium cultured under flow. Evaluation of the antithrombotic mechanism showed that parmodulins induce cytoprotective signaling through Gßγ, activating a PI3K/Akt pathway and eliciting a genetic program that includes suppression of NF-κB-mediated transcriptional activation and up-regulation of select cytoprotective transcripts. STC1 is among the up-regulated transcripts, and knockdown of stanniocalin-1 blocks the protective effects of both parmodulins and APC. Induction of this signaling pathway in vivo protects against thromboinflammatory injury in blood vessels. Small-molecule activation of endothelial cytoprotection through PAR1 represents an approach for treatment of thromboinflammatory disease and provides proof-of-principle for the strategy of targeting the cytoplasmic surface of GPCRs to achieve pathway selective signaling.


Assuntos
Células Endoteliais/metabolismo , Inflamação/metabolismo , Receptor PAR-1/agonistas , Trombose/metabolismo , Animais , Apoptose , Fator Xa/metabolismo , Técnicas de Silenciamento de Genes , Glicoproteínas/genética , Glicoproteínas/metabolismo , Células Endoteliais da Veia Umbilical Humana , Humanos , Lipopolissacarídeos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microcirculação , Peptídeo Hidrolases/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Transdução de Sinais , Transcrição Gênica , Regulação para Cima
12.
J Neurosci ; 39(36): 7102-7117, 2019 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-31320449

RESUMO

The lateral septum (LS) plays an important role in regulating aggression. It is well recognized that LS lesions lead to a dramatic increase in aggressive behaviors. A better understanding of LS neurophysiology and its functional output is therefore important to assess LS involvement in regulating aggression. The LS is a heterogeneous structure that maintains inputs and outputs with multiple brain regions, and is also divided into subregions that innervate one another. Thus, it is challenging to identify the exact cell type and projections for characterization. In this study, we determined the expression pattern of the calcium-activated chloride channel, TMEM16B, in the LS of both male and female mice. We then investigated the physiological contribution of the calcium-activated chloride channel to LS neuronal signaling. By performing whole-cell patch-clamp recording, we showed that TMEM16B alters neurotransmitter release at the hippocampal-LS synapse, and regulates spike frequency and spike frequency adaptation in subpopulations of LS neurons. We further demonstrated that loss of TMEM16B function promotes lengthened displays of aggressive behaviors by male mice during the resident intruder paradigm. In conclusion, our findings suggest that TMEM16B function contributes to neuronal excitability in subpopulations of LS neurons and the regulation of aggression in male mice.SIGNIFICANCE STATEMENT Aggression is a behavior that arose evolutionarily from the necessity to compete for limited resources and survival. One particular brain region involved in aggression is the lateral septum (LS). In this study, we characterized the expression of the TMEM16B calcium-activated chloride channel in the LS and showed that TMEM16B regulates the action potential firing frequency of LS neurons. We discovered that loss of TMEM16B function lengthens the displays of aggressive behaviors in male mice. These findings suggest that TMEM16B plays an important role in regulating LS neuronal excitability and behaviors associated with LS function, thereby contributing to our understanding of how the LS may regulate aggression.


Assuntos
Potenciais de Ação , Agressão , Anoctaminas/metabolismo , Núcleos Septais/fisiologia , Animais , Anoctaminas/genética , Feminino , Hipocampo/citologia , Hipocampo/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/metabolismo , Neurônios/fisiologia , Núcleos Septais/citologia , Núcleos Septais/metabolismo , Fatores Sexuais , Sinapses/metabolismo , Sinapses/fisiologia , Potenciais Sinápticos
13.
Neurobiol Dis ; 141: 104938, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32434047

RESUMO

INTRODUCTION: Alzheimer's disease (AD) is the most prevalent neurodegenerative disorder in elderly people. Existent therapies are directed at alleviating some symptoms, but are not effective in altering the course of the disease. METHODS: Based on our previous study that showed that an Aß-interacting small peptide protected against the toxic effects of amyloid-beta peptide (Aß), we carried out an array of in silico, in vitro, and in vivo assays to identify a molecule having neuroprotective properties. RESULTS: In silico studies showed that the molecule, referred to as M30 (2-Octahydroisoquinolin-2(1H)-ylethanamine), was able to interact with the Aß peptide. Additionally, in vitro assays showed that M30 blocked Aß aggregation, association to the plasma membrane, synaptotoxicity, intracellular calcium, and cellular toxicity, while in vivo experiments demonstrated that M30 induced a neuroprotective effect by decreasing the toxicity of Aß in the dentate gyrus of the hippocampus and improving the alteration in spatial memory in behavior assays. DISCUSSION: Therefore, we propose that this new small molecule could be a useful candidate for the additional development of a treatment against AD since it appears to block multiple steps in the amyloid cascade. Overall, since there are no drugs that effectively block the progression of AD, this approach represents an innovative strategy. SIGNIFICANCE: Currently, there is no effective treatment for AD and the expectations to develop an effective therapy are low. Using in silico, in vitro, and in vivo experiments, we identified a new compound that is able to inhibit Aß-induced neurotoxicity, specifically aggregation, association to neurons, synaptic toxicity, calcium dyshomeostasis and memory impairment induced by Aß. Because Aß toxicity is central to AD progression, the inhibition mediated by this new molecule might be useful as a therapeutic tool.


Assuntos
Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Fármacos Neuroprotetores/administração & dosagem , Agregação Patológica de Proteínas/prevenção & controle , Animais , Simulação por Computador , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Simulação de Acoplamento Molecular , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Células PC12 , Agregação Patológica de Proteínas/metabolismo , Ratos
14.
Environ Sci Technol ; 54(19): 12434-12446, 2020 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-32924453

RESUMO

In the long term, food systems must heed natural resource limits. Localized production and dietary changes are often suggested as potential solutions. However, no U.S. analyses fully evaluate the feasibility to scale localization across a range of diets. We therefore modeled the biophysical capacity for regional food systems based on agricultural land area and productivity, population, and 7 diet scenarios ranging in meat-intensity, from current consumption to vegan. We estimated foodshed size, colloquially known as "food miles" for 378 U.S. metropolitan centers, in a hypothetical nationwide closed system that prioritizes localized food. We found that foodshed size (weighted average distance traveled) for three land types ranged from 351-428 km (cultivated cropland), 80-492 km (perennial forage cropland), and 117-799 km (grazing land). Localized potential varies regionally: foodsheds are generally larger in the populous Northeast, Southeast, and Southwest than in the Northwest and the center of the country. However, depending on consumption of animal-based foods, a sizable proportion of the population could meet its food needs within 250km: from 35%-53% (cultivated cropland), 39%-94% (perennial forage cropland, 100% for vegan), and 26%-88% (grazing land, 100% for ovolacto-vegetarian and vegan). All seven scenarios leave some land unused. This reserve capacity might be used to supply food to the global market, grow bioenergy crops, or for conservation.


Assuntos
Agricultura , Dieta , Animais , Conservação dos Recursos Naturais , Produtos Agrícolas , Abastecimento de Alimentos , Carne
15.
Addict Biol ; 25(2): e12726, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-30884072

RESUMO

Here, we used knock-in (KI) mice that have ethanol-insensitive alpha 1 glycine receptors (GlyRs) (KK385/386AA) to examine how alpha 1 GlyRs might affect binge drinking and conditioned place preference. Data show that tonic alpha 1 GlyR-mediated currents were exclusively sensitive to ethanol only in wild-type mice. Behavioral studies showed that the KI mice have a higher intake of ethanol upon first exposure to drinking and greater conditioned place preference to ethanol. This study suggests that nonsynaptic alpha 1-containing GlyRs have a role in motivational and early reinforcing effects of ethanol.


Alcohol abuse leads to great medical, social, and economic burdens throughout the world. It is believed that the rewarding actions of alcohol are mediated by alterations in the mesolimbic dopaminergic system leading to increased levels of dopamine in the nucleus accumbens (NAc). Little is known about the role that ligand-gated ion channels (LGICs), such as glycine receptors (GlyRs), have in regulating levels of ethanol intake and place preference. In this study, we used knock-in (KI) mice that have ethanol-insensitive α1 GlyRs (KK385/386AA) and a combination of electrophysiological and behavioral approaches to examine how expression of ethanol-resistant α1 GlyRs in brain neurons might affect binge drinking and conditioned place preference. Data show that tonic α1 GlyR-mediated currents that modulate accumbal excitability were exclusively sensitive to ethanol only in wild-type (WT) mice. Behavioral studies showed that the KI mice have a higher intake of ethanol upon first exposure to drinking and greater conditioned place preference to ethanol, suggesting that α1 GlyRs in the brain have a protective role against abuse. This study suggests that nonsynaptic α1-containing GlyRs have a role in motivational and early reinforcing effects of ethanol and open a novel opportunity for pharmacotherapy development to treat alcohol use disorders.


Assuntos
Alcoolismo/fisiopatologia , Encéfalo/efeitos dos fármacos , Encéfalo/fisiopatologia , Etanol/farmacologia , Receptores de Glicina/metabolismo , Alcoolismo/metabolismo , Animais , Encéfalo/metabolismo , Modelos Animais de Doenças , Etanol/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Receptores de Glicina/efeitos dos fármacos
16.
BMC Nephrol ; 21(1): 452, 2020 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-33115436

RESUMO

BACKGROUND: Troponin T (TnT) is a well-known risk factor for negative outcome in hemodialysis (HD) patients, but little is known about variation over time, and the impact of clinical and dialysis specific factors. This study investigated the effect of angiotensin II receptor blockade (ARB), short and long-term variation in TnT and associations with clinical parameters. METHODS: In this analysis based on the SAFIR-cohort (Clinical Trials ID: NCT00791830) 81 HD patients were randomized double-blind for placebo (n = 40) or angiotensin II receptor blocker (ARB) treatment (n = 41) with irbesartan (150-300 mg) and followed for 12 months with six serial measurements of TnT using a high-sensitivity assay. RESULTS: Fifty-four patients (67%) completed follow-up. Baseline TnT-medians (min-max) were (placebo/ARB): 45(14-295)/46(10-343) ng/L. ARB-treatment did not significantly affect mean TnT-levels over the 12-month study period. Median week-to-week and one-year TnT-variation (5th-95th-percentile range) using all samples regardless of intervention were: 0(- 14-10) ng/L (week-to-week) and 3(- 40-71) ng/L (12 months). Median TnT-amplitude, capturing the change from the lowest to the highest TnT-value observed during the one-year study period was 38% or 20.5 ng/L. Median ratios with 95% limits of agreement were: 1.00(0.73-1.37); P = 0.92 (1 week/baseline; n = 77) and 1.07(0.52-2.25); P = 0.19 (12 months/baseline; n = 54). Baseline TnT was positively correlated with diabetes, ultrafiltration volume, arterial stiffness, change in intradialytic total peripheral resistance and N-terminal pro b-type natriuretic peptide (NT-proBNP) and negatively correlated with hematocrit, residual renal function and change in intradialytic cardiac output. High baseline TnT was associated with a higher risk of admission and cardiovascular (CV) events during follow-up. Increase in TnT over time (ΔTnT = 12-months-baseline) was significantly associated with increase in left ventricular (LV) mass and NT-proBNP and decrease in LV ejection fraction and late intradialytic stroke volume. ΔTnT was not significantly associated with admissions, CV or intradialytic hypotensive events during follow-up. Admissions were significantly more likely with a high (TnT-amplitude> 20.5 ng/L) than a low TnT-amplitude. Peaks in TnT were less frequent in aspirin-treated patients. CONCLUSION: ARB-treatment had no significant effect on TnT-levels. Week-to-week variation was generally low, yet over 12 months individual patients had considerable TnT fluctuations. Rise in TnT over time was significantly correlated with markers of cardiac deterioration. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00791830 . Date of registration: November 17, 2008. EudraCT no: 2008-001267-11.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Irbesartana/uso terapêutico , Falência Renal Crônica/sangue , Falência Renal Crônica/terapia , Diálise Renal , Troponina T/sangue , Idoso , Anti-Inflamatórios não Esteroides/uso terapêutico , Aspirina/uso terapêutico , Biomarcadores/sangue , Doenças Cardiovasculares/etiologia , Método Duplo-Cego , Feminino , Humanos , Falência Renal Crônica/complicações , Masculino , Pessoa de Meia-Idade , Diálise Renal/efeitos adversos , Fatores de Risco , Fatores de Tempo , Rigidez Vascular
17.
Environ Sci Technol ; 53(9): 5493-5503, 2019 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-31012575

RESUMO

We estimate the impact on greenhouse gas emissions (GHGE) of shifting from the current average United States diet to four alternative diets that meet the 2010 Dietary Guidelines for Americans (DGA). In contrast to prior studies, which rely on process-based life-cycle-analysis GHGE estimates from the literature for particular food items, we combine a diet model, an environmentally extended input-output model of energy use in the U.S. food system, and a biophysical model of land use for crops and livestock to estimate food system GHGE from the combustion of fossil fuels and from biogenic sources, including enteric fermentation, manure management, and soil management. We find that an omnivore diet that meets the DGA while constraining cost leaves food system GHGE essentially unchanged relative to the current baseline diet (985 000 000 tons of CO2 eq or 3191 kilograms of CO2 eq per capita per year), while a DGA-compliant vegetarian and a DGA-compliant omnivore diet that minimizes energy consumption in the food system reduce GHGE by 32% and 22%, respectively. These emission reductions were achieved mainly through quantity and composition changes in the meat, poultry, fish; dairy; and caloric sweeteners categories. Shifting from current to healthy diets as defined by the DGA does not necessarily reduce GHGE in the U.S. food system, although there are diets, including two presented here and by inference many others, which can achieve a reduction in GHGE.


Assuntos
Gases de Efeito Estufa , Animais , Dieta , Dieta Saudável , Ingestão de Energia , Efeito Estufa , Política Nutricional , Estados Unidos
18.
Kidney Blood Press Res ; 44(4): 704-714, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31362291

RESUMO

BACKGROUND: Central blood pressure (BP) assessed noninvasively considerably underestimates true invasively measured aortic BP in chronic kidney disease (CKD) patients. The difference between the estimated and the true aortic BP increases with decreasing estimated glomerular filtration rates (eGFR). The present study investigated whether aortic calcification affects noninvasive estimates of central BP. METHODS: Twenty-four patients with CKD stage 4-5 undergoing coronary angiography and an aortic computed tomography scan were included (63% males, age [mean ± SD ] 53 ± 11 years, and eGFR 9 ± 5 mL/min/1.73 m2). Invasive aortic BP was measured through the angiography catheter, while non-invasive central BP was obtained using radial artery tonometry with a SphygmoCor® device. The Agatston calcium score (CS) in the aorta was quantified on CT scans using the CS on CT scans. RESULTS: The invasive aortic systolic BP (SBP) was 152 ± 23 mm Hg, while the estimated central SBP was 133 ± 20 mm Hg. Ten patients had a CS of 0 in the aorta, while 14 patients had a CS >0 in the aorta. The estimated central SBP was lower than the invasive aortic SBP in patients with aortic calcification compared to patients without (mean difference 8 mm Hg, 95% CI 0.3-16; p = 0.04). The brachial SBP was lower than the aortic SBP in patients with aortic calcification compared to patients without (mean difference 10 mm Hg, 95% CI 2-19; p = 0.02). CONCLUSION: In patients with advanced CKD the presence of aortic calcification is associated with a higher difference between invasively measured central aortic BP and non-invasive estimates of central BP as compared to patients without calcifications.


Assuntos
Aorta/fisiopatologia , Determinação da Pressão Arterial/métodos , Calcinose , Insuficiência Renal Crônica/fisiopatologia , Adulto , Aorta/patologia , Pressão Arterial , Determinação da Pressão Arterial/normas , Cateterismo , Feminino , Taxa de Filtração Glomerular , Humanos , Masculino , Pessoa de Meia-Idade , Rigidez Vascular
19.
Cell Mol Life Sci ; 75(12): 2125-2135, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29520421

RESUMO

γδ T cells share characteristics of innate and adaptive immune cells and are involved in a broad spectrum of pro-inflammatory functions. Nonetheless, there is accumulating evidence that γδ T cells also exhibit regulatory functions. In this review, we describe the different phenotypes of regulatory γδ T cells in correlation with the identified mechanisms of suppression.


Assuntos
Receptores de Antígenos de Linfócitos T gama-delta/metabolismo , Linfócitos T Reguladores/fisiologia , Animais , Genes cdc/fisiologia , Humanos , Fenômenos do Sistema Imunitário/fisiologia , Tolerância Imunológica , Receptores de Antígenos de Linfócitos T gama-delta/fisiologia , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo
20.
Proc Natl Acad Sci U S A ; 113(44): 12520-12525, 2016 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-27791087

RESUMO

Vδ2Vγ9 T cells are the dominant γδ T-cell subset in human peripheral blood. Vδ2 T cells recognize pyrophosphate molecules derived from microbes or tumor cells; hence, they play a role in antimicrobial and antitumor immunity. TGF-ß, together with IL-15, induces a regulatory phenotype in Vδ2 T cells, characterized by forkhead box protein P3 (FoxP3) expression and suppressive activity on CD4 T-cell activation. We performed a genome-wide transcriptome analysis and found that the same conditions (TGF-ß plus IL-15) strongly enhanced the expression of additional genes in Vδ2 T cells, including IKAROS family zinc finger 4 (IKZF4; Eos), integrin subunit alpha E (ITGAE; CD103/αEß7), and IL9 This up-regulation was associated with potent IL-9 production as revealed by flow cytometry and multiplex analysis of cell culture supernatants. In contrast to CD4 and CD8 αß T cells, γδ T cells did not require IL-4 for induction of intracellular IL-9 expression. Upon antigen restimulation of Vδ2 T cells expanded in vitro in the presence of TGF-ß and IL-15, IL-9 was the most abundant among 16 analyzed cytokines and chemokines. IL-9 is a pleiotropic cytokine involved in various (patho)physiological conditions, including allergy and tumor defense, where it can promote antitumor immunity. Given the conspicuous sensitivity of many different tumors to Vδ2 T-cell-mediated killing, the conditions defined here for strong induction of IL-9 might be relevant for the development of Vδ2 T-cell-based immunotherapy.


Assuntos
Interleucina-9/imunologia , Receptores de Antígenos de Linfócitos T gama-delta/imunologia , Linfócitos T/imunologia , Transcriptoma/imunologia , Adulto , Células Cultivadas , Citocinas/genética , Citocinas/imunologia , Citocinas/metabolismo , Feminino , História Antiga , Humanos , Interleucina-15/farmacologia , Interleucina-9/genética , Interleucina-9/metabolismo , Masculino , Receptores de Antígenos de Linfócitos T gama-delta/metabolismo , Subpopulações de Linfócitos T/efeitos dos fármacos , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Linfócitos T/efeitos dos fármacos , Linfócitos T/metabolismo , Transcriptoma/efeitos dos fármacos , Fator de Crescimento Transformador beta/farmacologia , Regulação para Cima/efeitos dos fármacos
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