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1.
Cell ; 180(6): 1115-1129.e13, 2020 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-32200799

RESUMO

Influenza A virus (IAV) is a lytic RNA virus that triggers receptor-interacting serine/threonine-protein kinase 3 (RIPK3)-mediated pathways of apoptosis and mixed lineage kinase domain-like pseudokinase (MLKL)-dependent necroptosis in infected cells. ZBP1 initiates RIPK3-driven cell death by sensing IAV RNA and activating RIPK3. Here, we show that replicating IAV generates Z-RNAs, which activate ZBP1 in the nucleus of infected cells. ZBP1 then initiates RIPK3-mediated MLKL activation in the nucleus, resulting in nuclear envelope disruption, leakage of DNA into the cytosol, and eventual necroptosis. Cell death induced by nuclear MLKL was a potent activator of neutrophils, a cell type known to drive inflammatory pathology in virulent IAV disease. Consequently, MLKL-deficient mice manifest reduced nuclear disruption of lung epithelia, decreased neutrophil recruitment into infected lungs, and increased survival following a lethal dose of IAV. These results implicate Z-RNA as a new pathogen-associated molecular pattern and describe a ZBP1-initiated nucleus-to-plasma membrane "inside-out" death pathway with potentially pathogenic consequences in severe cases of influenza.


Assuntos
Vírus da Influenza A/genética , Necroptose/genética , Proteínas de Ligação a RNA/metabolismo , Animais , Apoptose/genética , Morte Celular/genética , Linhagem Celular Tumoral , Feminino , Vírus da Influenza A/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Necrose/metabolismo , Fosforilação , Proteínas Quinases/metabolismo , RNA/metabolismo , RNA de Cadeia Dupla/genética , RNA de Cadeia Dupla/metabolismo , Proteínas de Ligação a RNA/genética , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Proteína Serina-Treonina Quinases de Interação com Receptores/fisiologia
2.
Nature ; 628(8009): 835-843, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38600381

RESUMO

Severe influenza A virus (IAV) infections can result in hyper-inflammation, lung injury and acute respiratory distress syndrome1-5 (ARDS), for which there are no effective pharmacological therapies. Necroptosis is an attractive entry point for therapeutic intervention in ARDS and related inflammatory conditions because it drives pathogenic lung inflammation and lethality during severe IAV infection6-8 and can potentially be targeted by receptor interacting protein kinase 3 (RIPK3) inhibitors. Here we show that a newly developed RIPK3 inhibitor, UH15-38, potently and selectively blocked IAV-triggered necroptosis in alveolar epithelial cells in vivo. UH15-38 ameliorated lung inflammation and prevented mortality following infection with laboratory-adapted and pandemic strains of IAV, without compromising antiviral adaptive immune responses or impeding viral clearance. UH15-38 displayed robust therapeutic efficacy even when administered late in the course of infection, suggesting that RIPK3 blockade may provide clinical benefit in patients with IAV-driven ARDS and other hyper-inflammatory pathologies.


Assuntos
Lesão Pulmonar , Necroptose , Infecções por Orthomyxoviridae , Inibidores de Proteínas Quinases , Proteína Serina-Treonina Quinases de Interação com Receptores , Animais , Feminino , Humanos , Masculino , Camundongos , Células Epiteliais Alveolares/patologia , Células Epiteliais Alveolares/efeitos dos fármacos , Células Epiteliais Alveolares/virologia , Células Epiteliais Alveolares/metabolismo , Vírus da Influenza A/classificação , Vírus da Influenza A/efeitos dos fármacos , Vírus da Influenza A/imunologia , Vírus da Influenza A/patogenicidade , Lesão Pulmonar/complicações , Lesão Pulmonar/patologia , Lesão Pulmonar/prevenção & controle , Lesão Pulmonar/virologia , Camundongos Endogâmicos C57BL , Necroptose/efeitos dos fármacos , Infecções por Orthomyxoviridae/complicações , Infecções por Orthomyxoviridae/tratamento farmacológico , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/mortalidade , Infecções por Orthomyxoviridae/virologia , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Proteína Serina-Treonina Quinases de Interação com Receptores/antagonistas & inibidores , Síndrome do Desconforto Respiratório/complicações , Síndrome do Desconforto Respiratório/patologia , Síndrome do Desconforto Respiratório/prevenção & controle , Síndrome do Desconforto Respiratório/virologia
3.
Mol Cell ; 82(13): 2401-2414.e9, 2022 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-35597236

RESUMO

Activated CD8+ T lymphocytes differentiate into heterogeneous subsets. Using super-resolution imaging, we found that prior to the first division, dynein-dependent vesicular transport polarized active TORC1 toward the microtubule-organizing center (MTOC) at the proximal pole. This active TORC1 was physically associated with active eIF4F, required for the translation of c-myc mRNA. As a consequence, c-myc-translating polysomes polarized toward the cellular pole proximal to the immune synapse, resulting in localized c-myc translation. Upon division, the TORC1-eIF4A complex preferentially sorted to the proximal daughter cell, facilitating asymmetric c-Myc synthesis. Transient disruption of eIF4A activity at first division skewed long-term cell fate trajectories to memory-like function. Using a genetic barcoding approach, we found that first-division sister cells often displayed differences in transcriptional profiles that largely correlated with c-Myc and TORC1 target genes. Our findings provide mechanistic insights as to how distinct T cell fate trajectories can be established during the first division.


Assuntos
Linfócitos T CD8-Positivos , Fator de Iniciação 4F em Eucariotos , Diferenciação Celular , Ativação Linfocitária , Alvo Mecanístico do Complexo 1 de Rapamicina/genética
4.
Immunity ; 52(6): 994-1006.e8, 2020 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-32428502

RESUMO

Cell death pathways regulate various homeostatic processes. Autoimmune lymphoproliferative syndrome (ALPS) in humans and lymphoproliferative (LPR) disease in mice result from abrogated CD95-induced apoptosis. Because caspase-8 mediates CD95 signaling, we applied genetic approaches to dissect the roles of caspase-8 in cell death and inflammation. Here, we describe oligomerization-deficient Caspase-8F122GL123G/F122GL123G and non-cleavable Caspase-8D387A/D387A mutant mice with defective caspase-8-mediated apoptosis. Although neither mouse developed LPR disease, removal of the necroptosis effector Mlkl from Caspase-8D387A/D387A mice revealed an inflammatory role of caspase-8. Ablation of one allele of Fasl, Fadd, or Ripk1 prevented the pathology of Casp8D387A/D387AMlkl-/- animals. Removing both Fadd alleles from these mice resulted in early lethality prior to post-natal day 15 (P15), which was prevented by co-ablation of either Ripk1 or Caspase-1. Our results suggest an in vivo role of the inflammatory RIPK1-caspase-8-FADD (FADDosome) complex and reveal a FADD-independent inflammatory role of caspase-8 that involves activation of an inflammasome.


Assuntos
Caspase 8/genética , Suscetibilidade a Doenças , Proteína de Domínio de Morte Associada a Fas/metabolismo , Inflamação/etiologia , Inflamação/metabolismo , Necroptose/genética , Animais , Apoptose/genética , Biomarcadores , Caspase 8/química , Caspase 8/metabolismo , Modelos Animais de Doenças , Progressão da Doença , Imunofluorescência , Regulação da Expressão Gênica , Inflamassomos/metabolismo , Inflamação/mortalidade , Inflamação/patologia , Lipopolissacarídeos/efeitos adversos , Lipopolissacarídeos/imunologia , Camundongos , Camundongos Knockout , Mortalidade , Fenótipo , Multimerização Proteica
5.
Cell ; 157(5): 1189-202, 2014 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-24813850

RESUMO

Receptor-interacting protein kinase (RIPK)-1 is involved in RIPK3-dependent and -independent signaling pathways leading to cell death and/or inflammation. Genetic ablation of ripk1 causes postnatal lethality, which was not prevented by deletion of ripk3, caspase-8, or fadd. However, animals that lack RIPK1, RIPK3, and either caspase-8 or FADD survived weaning and matured normally. RIPK1 functions in vitro to limit caspase-8-dependent, TNFR-induced apoptosis, and animals lacking RIPK1, RIPK3, and TNFR1 survive to adulthood. The role of RIPK3 in promoting lethality in ripk1(-/-) mice suggests that RIPK3 activation is inhibited by RIPK1 postbirth. Whereas TNFR-induced RIPK3-dependent necroptosis requires RIPK1, cells lacking RIPK1 were sensitized to necroptosis triggered by poly I:C or interferons. Disruption of TLR (TRIF) or type I interferon (IFNAR) signaling delayed lethality in ripk1(-/-)tnfr1(-/-) mice. These results clarify the complex roles for RIPK1 in postnatal life and provide insights into the regulation of FADD-caspase-8 and RIPK3-MLKL signaling by RIPK1.


Assuntos
Caspase 8/metabolismo , Genes Letais , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Proteínas Adaptadoras de Transporte Vesicular/metabolismo , Animais , Animais Recém-Nascidos , Apoptose , Caspase 8/genética , Morte Celular , Embrião de Mamíferos/citologia , Embrião de Mamíferos/metabolismo , Proteína de Domínio de Morte Associada a Fas/metabolismo , Fibroblastos/metabolismo , Inflamação/metabolismo , Interferons/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Proteína Serina-Treonina Quinases de Interação com Receptores/genética , Receptores Tipo I de Fatores de Necrose Tumoral/genética , Receptores Tipo I de Fatores de Necrose Tumoral/metabolismo , Fatores de Necrose Tumoral/metabolismo
6.
Mol Cell ; 81(17): 3481-3495.e7, 2021 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-34358446

RESUMO

PRMT5 is an essential arginine methyltransferase and a therapeutic target in MTAP-null cancers. PRMT5 uses adaptor proteins for substrate recruitment through a previously undefined mechanism. Here, we identify an evolutionarily conserved peptide sequence shared among the three known substrate adaptors (CLNS1A, RIOK1, and COPR5) and show that it is necessary and sufficient for interaction with PRMT5. We demonstrate that PRMT5 uses modular adaptor proteins containing a common binding motif for substrate recruitment, comparable with other enzyme classes such as kinases and E3 ligases. We structurally resolve the interface with PRMT5 and show via genetic perturbation that it is required for methylation of adaptor-recruited substrates including the spliceosome, histones, and ribosomal complexes. Furthermore, disruption of this site affects Sm spliceosome activity, leading to intron retention. Genetic disruption of the PRMT5-substrate adaptor interface impairs growth of MTAP-null tumor cells and is thus a site for development of therapeutic inhibitors of PRMT5.


Assuntos
Proteína-Arginina N-Metiltransferases/metabolismo , Proteína-Arginina N-Metiltransferases/fisiologia , Animais , Linhagem Celular Tumoral , Citoplasma/metabolismo , Feminino , Células HCT116 , Células HEK293 , Histonas/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Canais Iônicos/metabolismo , Masculino , Metilação , Camundongos , Camundongos Nus , Proteínas Nucleares/metabolismo , Peptídeos/genética , Ligação Proteica , Processamento de Proteína Pós-Traducional , Proteínas Serina-Treonina Quinases/metabolismo , Proteína-Arginina N-Metiltransferases/genética , Spliceossomos/metabolismo
7.
Immunity ; 50(3): 576-590.e6, 2019 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-30770249

RESUMO

Elevated glucose metabolism in immune cells represents a hallmark feature of many inflammatory diseases, such as sepsis. However, the role of individual glucose metabolic pathways during immune cell activation and inflammation remains incompletely understood. Here, we demonstrate a previously unrecognized anti-inflammatory function of the O-linked ß-N-acetylglucosamine (O-GlcNAc) signaling associated with the hexosamine biosynthesis pathway (HBP). Despite elevated activities of glycolysis and the pentose phosphate pathway, activation of macrophages with lipopolysaccharide (LPS) resulted in attenuated HBP activity and protein O-GlcNAcylation. Deletion of O-GlcNAc transferase (OGT), a key enzyme for protein O-GlcNAcylation, led to enhanced innate immune activation and exacerbated septic inflammation. Mechanistically, OGT-mediated O-GlcNAcylation of the serine-threonine kinase RIPK3 on threonine 467 (T467) prevented RIPK3-RIPK1 hetero- and RIPK3-RIPK3 homo-interaction and inhibited downstream innate immunity and necroptosis signaling. Thus, our study identifies an immuno-metabolic crosstalk essential for fine-tuning innate immune cell activation and highlights the importance of glucose metabolism in septic inflammation.


Assuntos
Apoptose/fisiologia , Inflamação/metabolismo , N-Acetilglucosaminiltransferases/metabolismo , Necrose/metabolismo , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Animais , Linhagem Celular , Glucose/metabolismo , Humanos , Imunidade Inata/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Serina/metabolismo , Transdução de Sinais/fisiologia , Treonina/metabolismo
8.
Mol Cell ; 69(2): 238-252.e7, 2018 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-29351844

RESUMO

Maintenance of endoplasmic reticulum (ER) proteostasis is controlled by a dynamic signaling network known as the unfolded protein response (UPR). IRE1α is a major UPR transducer, determining cell fate under ER stress. We used an interactome screening to unveil several regulators of the UPR, highlighting the ER chaperone Hsp47 as the major hit. Cellular and biochemical analysis indicated that Hsp47 instigates IRE1α signaling through a physical interaction. Hsp47 directly binds to the ER luminal domain of IRE1α with high affinity, displacing the negative regulator BiP from the complex to facilitate IRE1α oligomerization. The regulation of IRE1α signaling by Hsp47 is evolutionarily conserved as validated using fly and mouse models of ER stress. Hsp47 deficiency sensitized cells and animals to experimental ER stress, revealing the significance of Hsp47 to global proteostasis maintenance. We conclude that Hsp47 adjusts IRE1α signaling by fine-tuning the threshold to engage an adaptive UPR.


Assuntos
Endorribonucleases/metabolismo , Proteínas de Choque Térmico HSP47/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Animais , Células COS , Chlorocebus aethiops , Proteínas de Ligação a DNA/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Retículo Endoplasmático/metabolismo , Estresse do Retículo Endoplasmático/fisiologia , Proteínas de Choque Térmico HSP47/fisiologia , Humanos , Camundongos , Chaperonas Moleculares/metabolismo , Transdução de Sinais , Estresse Fisiológico , Fatores de Transcrição/metabolismo , Resposta a Proteínas não Dobradas
9.
Am J Hum Genet ; 109(9): 1692-1712, 2022 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-36055214

RESUMO

Leucine zipper-EF-hand containing transmembrane protein 1 (LETM1) encodes an inner mitochondrial membrane protein with an osmoregulatory function controlling mitochondrial volume and ion homeostasis. The putative association of LETM1 with a human disease was initially suggested in Wolf-Hirschhorn syndrome, a disorder that results from de novo monoallelic deletion of chromosome 4p16.3, a region encompassing LETM1. Utilizing exome sequencing and international gene-matching efforts, we have identified 18 affected individuals from 11 unrelated families harboring ultra-rare bi-allelic missense and loss-of-function LETM1 variants and clinical presentations highly suggestive of mitochondrial disease. These manifested as a spectrum of predominantly infantile-onset (14/18, 78%) and variably progressive neurological, metabolic, and dysmorphic symptoms, plus multiple organ dysfunction associated with neurodegeneration. The common features included respiratory chain complex deficiencies (100%), global developmental delay (94%), optic atrophy (83%), sensorineural hearing loss (78%), and cerebellar ataxia (78%) followed by epilepsy (67%), spasticity (53%), and myopathy (50%). Other features included bilateral cataracts (42%), cardiomyopathy (36%), and diabetes (27%). To better understand the pathogenic mechanism of the identified LETM1 variants, we performed biochemical and morphological studies on mitochondrial K+/H+ exchange activity, proteins, and shape in proband-derived fibroblasts and muscles and in Saccharomyces cerevisiae, which is an important model organism for mitochondrial osmotic regulation. Our results demonstrate that bi-allelic LETM1 variants are associated with defective mitochondrial K+ efflux, swollen mitochondrial matrix structures, and loss of important mitochondrial oxidative phosphorylation protein components, thus highlighting the implication of perturbed mitochondrial osmoregulation caused by LETM1 variants in neurological and mitochondrial pathologies.


Assuntos
Proteínas de Ligação ao Cálcio , Doenças Mitocondriais , Proteínas de Ligação ao Cálcio/genética , Homeostase/genética , Humanos , Proteínas de Membrana/genética , Mitocôndrias/genética , Mitocôndrias/metabolismo , Doenças Mitocondriais/genética , Doenças Mitocondriais/metabolismo , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Sistema Nervoso/metabolismo , Saccharomyces cerevisiae/metabolismo
10.
Immunity ; 45(3): 513-526, 2016 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-27523270

RESUMO

The kinases RIPK1 and RIPK3 and the pseudo-kinase MLKL have been identified as key regulators of the necroptotic cell death pathway, although a role for MLKL within the whole animal has not yet been established. Here, we have shown that MLKL deficiency rescued the embryonic lethality caused by loss of Caspase-8 or FADD. Casp8(-/-)Mlkl(-/-) and Fadd(-/-)Mlkl(-/-) mice were viable and fertile but rapidly developed severe lymphadenopathy, systemic autoimmune disease, and thrombocytopenia. These morbidities occurred more rapidly and with increased severity in Casp8(-/-)Mlkl(-/-) and Fadd(-/-)Mlkl(-/-) mice compared to Casp8(-/-)Ripk3(-/-) or Fadd(-/-)Ripk3(-/-) mice, respectively. These results demonstrate that MLKL is an essential effector of aberrant necroptosis in embryos caused by loss of Caspase-8 or FADD. Furthermore, they suggest that RIPK3 and/or MLKL may exert functions independently of necroptosis. It appears that non-necroptotic functions of RIPK3 contribute to the lymphadenopathy, autoimmunity, and excess cytokine production that occur when FADD or Caspase-8-mediated apoptosis is abrogated.


Assuntos
Apoptose/fisiologia , Doenças Autoimunes/metabolismo , Morte Celular/fisiologia , Proteína de Domínio de Morte Associada a Fas/metabolismo , Proteínas Quinases/metabolismo , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Animais , Caspase 8/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Necrose/metabolismo
11.
Brain ; 147(5): 1899-1913, 2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38242545

RESUMO

Aberrant cholesterol metabolism causes neurological disease and neurodegeneration, and mitochondria have been linked to perturbed cholesterol homeostasis via the study of pathological mutations in the ATAD3 gene cluster. However, whether the cholesterol changes were compensatory or contributory to the disorder was unclear, and the effects on cell membranes and the wider cell were also unknown. Using patient-derived cells, we show that cholesterol perturbation is a conserved feature of pathological ATAD3 variants that is accompanied by an expanded lysosome population containing membrane whorls characteristic of lysosomal storage diseases. Lysosomes are also more numerous in Drosophila neural progenitor cells expressing mutant Atad3, which exhibit abundant membrane-bound cholesterol aggregates, many of which co-localize with lysosomes. By subjecting the Drosophila Atad3 mutant to nutrient restriction and cholesterol supplementation, we show that the mutant displays heightened cholesterol dependence. Collectively, these findings suggest that elevated cholesterol enhances tolerance to pathological ATAD3 variants; however, this comes at the cost of inducing cholesterol aggregation in membranes, which lysosomal clearance only partly mitigates.


Assuntos
ATPases Associadas a Diversas Atividades Celulares , Colesterol , Lisossomos , Proteínas de Membrana , Mutação , Animais , Colesterol/metabolismo , Humanos , ATPases Associadas a Diversas Atividades Celulares/genética , ATPases Associadas a Diversas Atividades Celulares/metabolismo , Lisossomos/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Drosophila , Membrana Celular/metabolismo , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo
12.
Proc Natl Acad Sci U S A ; 119(41): e2207240119, 2022 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-36191211

RESUMO

The absence of Caspase-8 or its adapter, Fas-associated death domain (FADD), results in activation of receptor interacting protein kinase-3 (RIPK3)- and mixed-lineage kinase-like (MLKL)-dependent necroptosis in vivo. Here, we show that spontaneous activation of RIPK3, phosphorylation of MLKL, and necroptosis in Caspase-8- or FADD-deficient cells was dependent on the nucleic acid sensor, Z-DNA binding protein-1 (ZBP1). We genetically engineered a mouse model by a single insertion of FLAG tag onto the N terminus of endogenous MLKL (MlklFLAG/FLAG), creating an inactive form of MLKL that permits monitoring of phosphorylated MLKL without activating necroptotic cell death. Casp8-/-MlklFLAG/FLAG mice were viable and displayed phosphorylated MLKL in a variety of tissues, together with dramatically increased expression of ZBP1 compared to Casp8+/+ mice. Studies in vitro revealed an increased expression of ZBP1 in cells lacking FADD or Caspase-8, which was suppressed by reconstitution of Caspase-8 or FADD. Ablation of ZBP1 in Casp8-/-MlklFLAG/FLAG mice suppressed spontaneous MLKL phosphorylation in vivo. ZBP1 expression and downstream activation of RIPK3 and MLKL in cells lacking Caspase-8 or FADD relied on a positive feedback mechanism requiring the nucleic acid sensors cyclic GMP-AMP synthase (cGAS), stimulator of interferon genes (STING), and TBK1 signaling pathways. Our study identifies a molecular mechanism whereby Caspase-8 and FADD suppress spontaneous necroptotic cell death.


Assuntos
Necroptose , Ácidos Nucleicos , Animais , Apoptose/fisiologia , Caspase 8/genética , Caspase 8/metabolismo , Proteínas de Ligação a DNA/metabolismo , Proteína de Domínio de Morte Associada a Fas/genética , Interferons/metabolismo , Camundongos , Nucleotidiltransferases/metabolismo , Proteínas Quinases/genética , Proteínas Quinases/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo
13.
Small ; : e2400816, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38949047

RESUMO

Intracellular reactive oxygen species (ROS) in steatotic cells pose a problem due to their potential to cause oxidative stress and cellular damage. Delivering engineered phospholipids to intracellular lipid droplets in steatotic hepatic cells, using the cell's inherent intracellular lipid transport mechanisms are investigated. Initially, it is shown that tail-labeled fluorescent lipids assembled into liposomes are able to be transported to intracellular lipid droplets in steatotic HepG2 cells and HHL-5 cells. Further, an antioxidant, an EUK salen-manganese derivative, which has superoxide dismutase-like and catalase-like activity, is covalently conjugated to the tail of a phospholipid and formulated as liposomes for administration. Steatotic HepG2 cells and HHL-5 cells incubated with these antioxidant liposomes have lower intracellular ROS levels compared to untreated controls and non-covalently formulated antioxidants. This first proof-of-concept study illustrates an alternative strategy to equip native organelles in mammalian cells with engineered enzyme activity.

14.
Mol Cell ; 61(4): 589-601, 2016 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-26853145

RESUMO

Necroptosis is a cell death pathway regulated by the receptor interacting protein kinase 3 (RIPK3) and the mixed lineage kinase domain-like (MLKL) pseudokinase. How MLKL executes plasma membrane rupture upon phosphorylation by RIPK3 remains controversial. Here, we characterize the hierarchical transduction of structural changes in MLKL that culminate in necroptosis. The MLKL brace, proximal to the N-terminal helix bundle (NB), is involved in oligomerization to facilitate plasma membrane targeting through the low-affinity binding of NB to phosphorylated inositol polar head groups of phosphatidylinositol phosphate (PIP) phospholipids. At the membrane, the NB undergoes a "rolling over" mechanism to expose additional higher-affinity PIP-binding sites responsible for robust association to the membrane and displacement of the brace from the NB. PI(4,5)P2 is the preferred PIP-binding partner. We investigate the specific association of MLKL with PIPs and subsequent structural changes during necroptosis.


Assuntos
Fibroblastos/citologia , Fosfatos de Fosfatidilinositol/metabolismo , Proteínas Quinases/química , Proteínas Quinases/metabolismo , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Animais , Apoptose , Sítios de Ligação , Linhagem Celular , Membrana Celular/metabolismo , Fibroblastos/metabolismo , Humanos , Camundongos , Modelos Moleculares , Fosforilação , Proteínas Quinases/genética , Multimerização Proteica , Estrutura Terciária de Proteína , Proteína Serina-Treonina Quinases de Interação com Receptores/genética
15.
Eur J Anaesthesiol ; 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38916221

RESUMO

BACKGROUND: Preoperative anxiety (PA) is common in children and has detrimental effects on surgical outcome. Strategies based on virtual reality (VR) have recently been introduced to address this problem. OBJECTIVE: This study evaluated the usefulness of a virtual reality educational program (VREP) for reducing preoperative anxiety in elective low-complexity paediatric surgery. DESIGN: Randomised clinical trial. SETTING: Single tertiary centre in Barcelona, Spain. Between January 2019 and June 2022. PATIENTS: Children aged 3-13 years of age, American Society of Anesthesiologists (ASA) I-II, scheduled for elective low-complexity surgery were enrolled in the study. INTERVENTION: Children were randomised into a control group (received oral/written information about the anaesthetic-surgical process, and patients and their parents remained in a playroom waiting for the surgery) or VREP (viewed a VR-based educational video on the surgical process, 7-10 days prior to surgery) using the MATLAB application. MAIN OUTCOME MEASURE: PA using the modified Yale Preoperative Anxiety Scale (mYPAS) during separation from parents. RESULTS: In total, 241 children aged 3-12 years of age were studied (120 patients with VREP and 121 controls). Randomisation eliminated the differences between the groups, except for a greater male presence in the VREP group (83.3% vs. 71.1%; P = 0.023). The mYPAS yielded was lower in the VREP group (29.2% vs. 83.5%; P < 0.001). Sex did not influence VREP-mediated decrease in PA (P < 0.001). In turn, VREP patients were more cooperative (Induction Compliance Checklist [ICC] score 0 points vs. 2 points; P < 0.001) during anaesthesia induction, presented less delirium (Pediatric Anesthesia Emergence Delirium [PAED] score 1 point vs. 3 points; P = 0.001) on leaving the recovery room, and experienced less pain upon arrival in the hospital ward (Wong-Baker Faces Pain Rating Scale: 0-points vs. 1 point; P < 0.001). CONCLUSIONS: The VREP-based prevention strategy reduced preoperative anxiety in children undergoing elective low-complexity surgery. TRIAL REGISTRATION: NCT03578393.

16.
Molecules ; 29(8)2024 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-38675590

RESUMO

In this article, we present a comprehensive computational investigation into the reaction mechanism of N-arylation of substituted aryl halides through Ullmann-type coupling reactions. Our computational findings, obtained through DFT ωB97X-D/6-311G(d,p) and ωB97X-D/LanL2DZ calculations, reveal a direct relation between the previously reported experimental reaction yields and the activation energy of haloarene activation, which constitutes the rate-limiting step in the overall coupling process. A detailed analysis of the reaction mechanism employing the Activation Strain Model indicates that the strain in the substituted iodoanilines is the primary contributor to the energy barrier, representing an average of 80% of the total strain energy. Additional analysis based on conceptual Density Functional Theory (DFT) suggests that the nucleophilicity of the nitrogen in the lactam is directly linked to the activation energies. These results provide valuable insights into the factors influencing energetic barriers and, consequently, reaction yields. These insights enable the rational modification of reactants to optimize the N-arylation process.

17.
Pain Pract ; 24(1): 42-51, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37493072

RESUMO

BACKGROUND: Intrathecal infusion therapy is widely accepted for cancer pain patients when conventional analgesic treatments are not sufficient. There are different types of devices for carrying out this therapy: partially externalized devices (PED), used when life expectancy is under 3 months, and totally implanted devices (TID), when it is larger. Our objective is to compare the efficacy, functionality, and complication rate in both types. METHODS: We included 132 patients with mild-severe cancer pain, treated with intrathecal infusion therapy by fixed flow devices, PED, or TID, during the study time. Demographic, physical oncologic, and pain control data of the patients were recorded prior to starting therapy and at months 1, 3, and 6. Functionality status and complications were also collected from the patient's medical records and clinical files. RESULTS: Pain control improved after starting therapy, with an overall reduction of 4.75 points in VAS score at 1 month in the both groups, without significant differences between them, keeping it at 3 months and 6. 33.3% of the patients developed complications and were more frequent in the PED group, being catheter dislocation the most common. Patients with TID required more often hospital admission to solve the complication. CONCLUSIONS: Intrathecal infusion therapy has been shown to be a very effective and safe therapy for the treatment of moderate to severe oncologic pain. There are no significant differences between PED and TID in terms of degree of pain control, therapeutic success, efficacy on episodic or nocturnal pain, or the presence of serious complications.


Assuntos
Dor do Câncer , Neoplasias , Humanos , Dor do Câncer/tratamento farmacológico , Dor do Câncer/etiologia , Analgésicos/uso terapêutico , Dor/tratamento farmacológico , Dor/etiologia , Injeções Espinhais , Neoplasias/complicações , Neoplasias/tratamento farmacológico
18.
Circulation ; 146(22): 1644-1656, 2022 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-36321460

RESUMO

BACKGROUND: Ablation of ventricular tachycardia (VT) in the setting of structural heart disease often requires extensive substrate elimination that is not always achievable by endocardial radiofrequency ablation. Epicardial ablation is not always feasible. Case reports suggest that venous ethanol ablation (VEA) through a multiballoon, multivein approach can lead to effective substrate ablation, but large data sets are lacking. METHODS: VEA was performed in 44 consecutive patients with ablation-refractory VT (ischemic, n=21; sarcoid, n=3; Chagas, n=2; idiopathic, n=18). Targeted veins were selected by mapping coronary veins on the epicardial aspect of endocardial scar (identified by bipolar voltage <1.5 mV), using venography and signal recording with a 2F octapolar catheter or by guidewire unipolar signals. Epicardial mapping was performed in 15 patients. Vein segments in the epicardial aspect of VT substrates were treated with double-balloon VEA by blocking flow with 1 balloon while injecting ethanol through the lumen of the second balloon, forcing (and restricting) ethanol between balloons. Multiple balloon deployments and multiple veins were used as needed. In 22 patients, late gadolinium enhancement cardiac magnetic resonance imaged the VEA scar and its evolution. RESULTS: Median ethanol delivered was 8.75 (interquartile range, 4.5-13) mL. Injected veins included interventricular vein (6), diagonal (5), septal (12), lateral (16), posterolateral (7), and middle cardiac vein (8), covering the entire range of left ventricular locations. Multiple veins were targeted in 14 patients. Ablated areas were visualized intraprocedurally as increased echogenicity on intracardiac echocardiography and incorporated into 3-dimensional maps. After VEA, vein and epicardial ablation maps showed elimination of abnormal electrograms of the VT substrate. Intracardiac echocardiography demonstrated increased intramural echogenicity at the targeted region of the 3-dimensional maps. At 1 year of follow-up, median of 314 (interquartile range, 198-453) days of follow-up, VT recurrence occurred in 7 patients, for a success of 84.1%. CONCLUSIONS: Multiballoon, multivein intramural ablation by VEA can provide effective substrate ablation in patients with ablation-refractory VT in the setting of structural heart disease over a broad range of left ventricular locations.


Assuntos
Ablação por Cateter , Taquicardia Ventricular , Humanos , Vasos Coronários , Cicatriz , Etanol/uso terapêutico , Meios de Contraste , Gadolínio , Taquicardia Ventricular/cirurgia , Taquicardia Ventricular/etiologia , Ablação por Cateter/efeitos adversos
19.
Stroke ; 54(4): 955-963, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36846963

RESUMO

BACKGROUND: Most studies on stroke have been designed to examine one deficit in isolation; yet, survivors often have multiple deficits in different domains. While the mechanisms underlying multiple-domain deficits remain poorly understood, network-theoretical methods may open new avenues of understanding. METHODS: Fifty subacute stroke patients (7±3days poststroke) underwent diffusion-weighted magnetic resonance imaging and a battery of clinical tests of motor and cognitive functions. We defined indices of impairment in strength, dexterity, and attention. We also computed imaging-based probabilistic tractography and whole-brain connectomes. To efficiently integrate inputs from different sources, brain networks rely on a rich-club of a few hub nodes. Lesions harm efficiency, particularly when they target the rich-club. Overlaying individual lesion masks onto the tractograms enabled us to split the connectomes into their affected and unaffected parts and associate them to impairment. RESULTS: We computed efficiency of the unaffected connectome and found it was more strongly correlated to impairment in strength, dexterity, and attention than efficiency of the total connectome. The magnitude of the correlation between efficiency and impairment followed the order attention>dexterity ≈ strength (strength: |r|=.03, P=0.02, dexterity: |r|=.30, P=0.05, attention: |r|=.55, P<0.001). Network weights associated with the rich-club were more strongly correlated to efficiency than non-rich-club weights. CONCLUSIONS: Attentional impairment is more sensitive to disruption of coordinated networks between brain regions than motor impairment, which is sensitive to disruption of localized networks. Providing more accurate reflections of actually functioning parts of the network enables the incorporation of information about the impact of brain lesions on connectomics contributing to a better understanding of underlying stroke mechanisms.


Assuntos
Disfunção Cognitiva , Conectoma , Acidente Vascular Cerebral , Humanos , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Imagem de Difusão por Ressonância Magnética/métodos , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/patologia , Disfunção Cognitiva/patologia , Cognição , Conectoma/métodos , Imageamento por Ressonância Magnética
20.
J Clin Immunol ; 43(2): 271-285, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36251205

RESUMO

Patients with inborn errors of immunity (IEI) in Argentina were encouraged to receive licensed Sputnik, AstraZeneca, Sinopharm, Moderna, and Pfizer vaccines, even though most of the data of humoral and cellular responses combination on available vaccines comes from trials conducted in healthy individuals. We aimed to evaluate the safety and immunogenicity of the different vaccines in IEI patients in Argentina. The study cohort included adults and pediatric IEI patients (n = 118) and age-matched healthy controls (HC) (n = 37). B cell response was evaluated by measuring IgG anti-spike/receptor binding domain (S/RBD) and anti-nucleocapsid(N) antibodies by ELISA. Neutralization antibodies were also assessed with an alpha-S protein-expressing pseudo-virus assay. The T cell response was analyzed by IFN-γ secretion on S- or N-stimulated PBMC by ELISPOT and the frequency of S-specific circulating T follicular-helper cells (TFH) was evaluated by flow cytometry.No moderate/severe vaccine-associated adverse events were observed. Anti-S/RBD titers showed significant differences in both pediatric and adult IEI patients versus the age-matched HC cohort (p < 0.05). Neutralizing antibodies were also significantly lower in the patient cohort than in age-matched HC (p < 0.01). Positive S-specific IFN-γ response was observed in 84.5% of IEI patients and 82.1% presented S-specific TFH cells. Moderna vaccines, which were mainly administered in the pediatric population, elicited a stronger humoral response in IEI patients, both in antibody titer and neutralization capacity, but the cellular immune response was similar between vaccine platforms. No difference in humoral response was observed between vaccinated patients with and without previous SARS-CoV-2 infection.In conclusion, COVID-19 vaccines showed safety in IEI patients and, although immunogenicity was lower than HC, they showed specific anti-S/RBD IgG, neutralizing antibody titers, and T cell-dependent cellular immunity with IFN-γ secreting cells. These findings may guide the recommendation for a vaccination with all the available vaccines in IEI patients to prevent COVID-19 disease.


Assuntos
COVID-19 , Vacinas , Adulto , Humanos , Criança , Vacinas contra COVID-19 , Leucócitos Mononucleares , COVID-19/prevenção & controle , SARS-CoV-2 , Vacinação , Anticorpos Neutralizantes , ELISPOT , Imunoglobulina G , Anticorpos Antivirais , Imunidade Celular
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