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BACKGROUND: Cerebral tissue damage after an ischemic event can be exacerbated by inflammation and thrombosis. Elevated extracellular ATP and ADP levels are associated with cellular injury, inflammation, and thrombosis. Ectonucleoside triphosphate diphosphohydrolase-1 (CD39), an enzyme expressed on the plasmalemma of leukocytes and endothelial cells, suppresses platelet activation and leukocyte infiltration by phosphohydrolyzing ATP/ADP. To investigate the effects of increased CD39 in an in vivo cerebral ischemia model, we developed a transgenic mouse expressing human CD39 (hCD39). METHODS: A floxed-stop sequence was inserted between the promoter and the hCD39 transcriptional start site, generating a mouse in which the expression of hCD39 can be controlled tissue-specifically using Cre recombinase mice. We generated mice that express hCD39 globally or in myeloid-lineage cells only. Cerebral ischemia was induced by middle cerebral artery occlusion. Infarct volumes were quantified by MRI after 48 hours. RESULTS: Both global and transgenic hCD39- and myeloid lineage CD39-overexpressing mice (transgenic, n=9; myeloid lineage, n=6) demonstrated significantly smaller cerebral infarct volumes compared with wild-type mice. Leukocytes from ischemic and contralateral hemispheres were analyzed by flow cytometry. Although contralateral hemispheres had equal numbers of macrophages and neutrophils, ischemic hemispheres from transgenic mice had less infiltration (n=4). Transgenic mice showed less neurological deficit compared with wild-type mice (n=6). CONCLUSIONS: This is the first report of transgenic overexpression of CD39 in mice imparting a protective phenotype after stroke, with reduced leukocyte infiltration, smaller infarct volumes, and decreased neurological deficit. CD39 overexpression, either globally or in myeloid lineage cells, quenches postischemic leukosequestration and reduces stroke-induced neurological injury.
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Antígenos CD/biossíntese , Antígenos CD/genética , Apirase/biossíntese , Apirase/genética , Isquemia Encefálica/genética , Isquemia Encefálica/metabolismo , Linhagem da Célula/fisiologia , Transgenes/fisiologia , Animais , Isquemia Encefálica/prevenção & controle , Expressão Gênica , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Células Mieloides/fisiologiaRESUMO
We report a new class of functionalized polylutidine polymers that are prepared by chemical vapor deposition polymerization of substituted [2](1,4)benzeno[2](2,5)pyridinophanes. To prepare sufficient amounts of monomer for CVD polymerization, a new synthesis route for ethynylpyridinophane has been developed in three steps with an overall yield of 59 %. Subsequent CVD polymerization yielded well-defined films of poly(2,5-lutidinylene-co-p-xylylene) and poly(4-ethynyl-2,5-lutidinylene-co-p-xylylene). All polymers were characterized by infrared reflection-absorption spectroscopy, ellipsometry, contact angle studies, and X-ray photoelectron spectroscopy. Moreover, ζ-potential measurements revealed that polylutidine films have higher isoelectric points than the corresponding poly-xylylene surfaces owing to the nitrogen atoms in the polymer backbone. The availability of reactive alkyne groups on the surface of poly(4-ethynyl-2,5-lutidinylene-co-p-xylylene) coatings was confirmed by spatially controlled surface modification by means of Huisgen 1,3-dipolar cycloaddition. Compared to the more hydrophobic poly-p-xylylyenes, the presence of the heteroatom in the polymer backbone of polylutidine polymers resulted in surfaces that supported an increased adhesion of primary human umbilical vein endothelial cells (HUVECs). Vapor-based polylutidine coatings are a new class of polymers that feature increased hydrophilicity and increased cell adhesion without limiting the flexibility in selecting appropriate functional side groups.
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The ectoenzyme CD39 suppresses thrombosis and inflammation by suppressing ATP and ADP to AMP. However, mechanisms of CD39 transcriptional and post-translational regulation are not well known. Here we show that CD39 levels are modulated by inhibition of phosphodiesterase 3 (PDE3). RAW macrophages and human umbilical vein endothelial cells (HUVECs) were treated with the PDE3 inhibitors cilostazol and milrinone, then analyzed using qRT-PCR, immunoprecipitation/Western blot, immunofluorescent staining, radio-thin-layer chromatography, a malachite green assay, and ELISA. HUVECs expressed elevated CD39 protein (2-fold [P<0.05] for cilostazol and 2.5-fold [P<0.01] for milrinone), while macrophage CD39 mRNA and protein were both elevated after PDE3 inhibition. HUVEC ATPase activity increased by 25% with cilostazol and milrinone treatment (P<0.05 and P<0.01, respectively), as did ADPase activity (47% and 61%, P<0.001). There was also a dose-dependent elevation of soluble CD39 after treatment with 8-Br-cAMP, with maximal elevation of 60% more CD39 present compared to controls (1 mM, P<0.001). Protein harvested after 8-Br-cAMP treatment showed that ubiquitination of CD39 was decreased by 43% compared to controls. A DMSO or PBS vehicle control was included for each experiment based on solubility of cilostazol, milrinone, and 8-Br-cAMP. These results indicate that PDE3 inhibition regulates endothelial CD39 at a post-translational level.
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Antígenos CD/genética , Apirase/genética , Nucleotídeo Cíclico Fosfodiesterase do Tipo 3/metabolismo , Regulação Enzimológica da Expressão Gênica , Transcrição Gênica , 8-Bromo Monofosfato de Adenosina Cíclica/farmacologia , Adenosina Trifosfatases/genética , Adenosina Trifosfatases/metabolismo , Cilostazol , Nucleotídeo Cíclico Fosfodiesterase do Tipo 3/efeitos dos fármacos , Nucleotídeo Cíclico Fosfodiesterase do Tipo 3/genética , Inibidores Enzimáticos/farmacologia , Células Endoteliais da Veia Umbilical Humana , Humanos , Macrófagos/metabolismo , Milrinona/farmacologia , Tetrazóis/farmacologia , UbiquitinaçãoRESUMO
Apoptosis of immature peripheral B cells may be due to a lack of survival signals rather than clonal deletion.
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Linfócitos B , Humanos , Linfócitos B/metabolismo , Linfócitos B/imunologia , Linfócitos B/citologia , Animais , Apoptose , Transdução de SinaisRESUMO
Secreted factors from pyroptotic cells can promote wound repair.
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Piroptose , Cicatrização , Humanos , AnimaisRESUMO
Inflammasome activation by circulating DNA leads to recurrent stroke associated with atherosclerosis.
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DNA , Inflamassomos , Acidente Vascular Cerebral , Humanos , Acidente Vascular Cerebral/genética , Acidente Vascular Cerebral/metabolismo , Inflamassomos/metabolismo , DNA/genética , DNA/metabolismo , Aterosclerose/genética , Aterosclerose/metabolismo , AnimaisRESUMO
The DNA double-strand break sensor MRE11 is necessary to liberate cGAS and enable its activation by dsDNA.
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Quebras de DNA de Cadeia Dupla , Nucleotidiltransferases , Nucleotidiltransferases/genéticaRESUMO
Microglial lipid droplet accumulation leads to increased neurotoxicity in an APOE-dependent manner.
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Doença de Alzheimer , Humanos , Doença de Alzheimer/tratamento farmacológico , Lipídeos , Apolipoproteínas E/genéticaRESUMO
ATP released by osteoblasts signals through the purinergic receptor P2RX4 to optimize plasma cell survival.
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Osteoblastos , Plasmócitos , Sobrevivência CelularRESUMO
Prostaglandins in the tumor microenvironment block IL-2-induced expansion of killer T cells.
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Interleucina-2 , Microambiente Tumoral , Interleucina-2/imunologia , Interleucina-2/metabolismo , Humanos , Microambiente Tumoral/imunologia , Animais , Neoplasias/imunologia , Neoplasias/metabolismo , Prostaglandinas/metabolismoRESUMO
Highlights from the Science family of journals.
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Highlights from the Science family of journals.
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Highlights from the Science family of journals.
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Highlights from the Science family of journals.
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Highlights from the Science family of journals.
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Highlights from the Science family of journals.
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Loss of phosphatidylinositol transfer protein alpha underlies pancreatic ß cell failure.
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Células Secretoras de Insulina , Células Secretoras de Insulina/metabolismoRESUMO
Catecholamines associated with stress promote T cell exhaustion through the ß1-adrenergic receptor.
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Catecolaminas , Linfócitos TRESUMO
Interferon-ε has antitumor activity and activates antitumor immunity in ovarian cancer in mice.
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Interferons , Neoplasias Ovarianas , Animais , Camundongos , Feminino , Humanos , Neoplasias Ovarianas/tratamento farmacológicoRESUMO
Demyelination by microglia reduces the likelihood of axonal degeneration in a model of cytotoxic T cell-driven myelin perturbation.