Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 52
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Anaesthesiologie ; 73(4): 244-250, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38349537

RESUMEN

BACKGROUND: Anesthesiology has a relevant carbon footprint, mainly due to volatile anesthetics (scope 1 emissions). Additionally, energy used in the operating theater (scope 2 emissions) contributes to anesthesia-related greenhouse gas (GHG) emissions. OBJECTIVES: Optimizing the electricity use of medical devices might reduce both GHG emissions and costs might hold potential to reduce anaesthesia-related GHG-emissions and costs. We analyzed the electricity consumption of six different anesthesia workstations, calculated their GHG emissions and electricity costs and investigated the potential to reduce emissions and cost by using the devices in a more efficient way. METHODS: Power consumption (active power in watt , W) was measured with the devices off, in standby mode, or fully on with the measuring instrument SecuLife ST. Devices studied were: Dräger Primus, Löwenstein Medical LeonPlus, Getinge Flow C, Getinge Flow E, GE Carestation 750 and GE Aisys. Calculations of GHG emissions were made with different emission factors, ranging from very low (0.09 kg CO2-equivalent/kWh) to very high (0.660 kg CO2-equivalent/kWh). Calculations of electricity cost were made assuming a price of 0.25 € per kWh. RESULTS: Power consumption during operation varied from 58 W (GE CareStation 750) to 136 W (Dräger Primus). In standby, the devices consumed between 88% and 93% of the electricity needed during use. The annual electricity consumption to run 96 devices in a large clinical department ranges between 45 and 105 Megawatt-hours (MWh) when the devices are left in standby during off hours. If 80% of the devices are switched off during off hours, between 20 and 46 MWh can be saved per year in a single institution. At the average emission factor of our hospital, this electricity saving corresponds to a reduction of GHG emissions between 8.5 and 19.8 tons CO2-equivalent. At the assumed prices, a cost reduction between 5000 € and 11,600 € could be achieved by this intervention. CONCLUSION: The power consumption varies considerably between the different types of anesthesia workstations. All devices exhibit a high electricity consumption in standby mode. Avoiding standby mode during off hours can save energy and thus GHG emissions and cost. The reductions in GHG emissions and electricity cost that can be achieved with this intervention in a large anesthesiology department are modest. Compared with GHG emissions generated by volatile anesthetics, particularly desflurane, optimization of electricity consumption of anesthesia workstations holds a much smaller potential to reduce the carbon footprint of anesthesia; however, as switching off anesthesia workstations overnight is relatively effortless, this behavioral change should be encouraged from both an ecological and economical point of view.


Asunto(s)
Anestesia , Anestésicos , Gases de Efecto Invernadero , Dióxido de Carbono , Gases de Efecto Invernadero/análisis , Electricidad
2.
PLoS One ; 18(11): e0294134, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37971973

RESUMEN

The presence of per- and polyfluoroalkyl substances (PFAS) in U.S. drinking water has recently garnered significant attention from the media, federal government, and public health professionals. While concerns for PFAS exposure continue to mount, the general public's awareness and knowledge of the contaminant has remained unknown. This exploratory study sought to fill this data gap by administering a nationwide survey in which the awareness of PFAS and community contamination, awareness of PFAS containing products and intentions to change product use, and awareness and concern about PFAS in drinking water were assessed. The results indicated that almost half the respondents had never heard of PFAS and do not know what it is (45.1%). Additionally, 31.6% responded that they had heard of PFAS but do not know what it is. A large portion of respondents (97.4%) also responded that they did not believe their drinking water had been impacted by PFAS. Demographic association did not influence knowledge of PFAS or levels of concern with PFAS in drinking water. The strongest predictor of PFAS awareness was awareness due to known community exposure. The respondents aware of community exposure were more likely to have knowledge of PFAS sources, change their use of items with potential PFAS contamination, and answer that their drinking water sources were also contaminated with PFAS. Based on the received responses, PFAS information and health risks need to be better communicated to the public to help increase awareness. These efforts should also be coordinated between government agencies, utilities, the research community, and other responsible entities to bolster their effectiveness.


Asunto(s)
Ácidos Alcanesulfónicos , Agua Potable , Fluorocarburos , Contaminantes Químicos del Agua , Estados Unidos , Agua Potable/análisis , Contaminantes Químicos del Agua/análisis , Contaminación de Medicamentos , Gobierno Federal
3.
PeerJ ; 11: e16073, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37780377

RESUMEN

Evaluating estuary water quality responses to reductions (or increases) in nutrient loading attributed to on the ground management actions can be challenging due to the strong influence of environmental drivers on nutrient loads and non-linear relationships. This study applied generalized additive models to calculate watershed nutrient loads and assess responses in estuary water quality to seasonally-adjusted freshwater inflow and flow-adjusted nutrient loads in Lavaca Bay, Texas. Lavaca Bay is a secondary embayment on the Texas coast displaying early potential for eutrophication and water quality degradation. Use of flow-adjusted nutrient loads allowed the study to evaluate the response in water quality to changes in nutrient loads driven by anthropogenic sources. Cross-validation indicated that, despite data constraints, semiparametric models performed well at nutrient load prediction. Based on these models, delivered annual nutrient loads varied substantially from year to year. In contrast, minimal changes in flow-normalized loads indicate that nutrient loadings were driven by natural variation in precipitation and runoff as opposed to changes in management of nonpoint sources. Models indicated no evidence of long-term changes in dissolved oxygen or chlorophyll-a within Lavaca Bay. However, site specific long-term increases in both organic and inorganic nitrogen are concerning for their potential to fuel eutrophication. Further analysis found freshwater inflow had strong influences on nutrient and chlorophyll-a concentrations but there was no evidence that changes in watershed nutrient loading explained additional variation in dissolved oxygen and limited evidence that watershed nutrient loadings explained chlorophyll-a concentrations. In addition to providing a baseline assessment of watershed nutrient loading and water quality responses in the Lavaca Bay watershed, this study provides methodological support for the use of semiparametric models in load regression models and estuary assessments.


Asunto(s)
Estuarios , Calidad del Agua , Clorofila/análisis , Clorofila A/análisis , Nutrientes/análisis , Oxígeno/análisis
4.
Org Lett ; 25(32): 5969-5973, 2023 Aug 18.
Artículo en Inglés | MEDLINE | ID: mdl-37540115

RESUMEN

Synthesis and host-guest chemistry of water-soluble (pH 12.5) chiral spirobifluorene-based macrocycles 2-[n] were carried out. Cationic guests, such as quaternary ammonium salts, were accommodated well in the hosts. Cp2Co+ was especially strongly bound in 2-[4] (Ka of up to 3.0 × 105 M-1). Enantioselective recognition with (l)-carnitine was also achieved.

5.
Autophagy ; 18(5): 1090-1107, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-34482812

RESUMEN

Non-canonical autophagy pathways decorate single-membrane vesicles with Atg8-family proteins such as MAP1LC3/LC3 (microtubule-associated protein 1 light chain 3). Phagosomes containing the bacterial pathogen Listeria monocytogenes (L.m.) can be targeted by a non-canonical autophagy pathway called LC3-associated phagocytosis (LAP), which substantially contributes to the anti-listerial activity of macrophages and immunity. We here characterized a second non-canonical autophagy pathway targeting L.m.-containing phagosomes, which is induced by damage caused to the phagosomal membrane by the pore-forming toxin of L.m., listeriolysin O. This pore-forming toxin-induced non-canonical autophagy pathway (PINCA) was the only autophagic pathway evoked in tissue macrophages deficient for the NADPH oxidase CYBB/NOX2 that produces the reactive oxygen species (ROS) that are required for LAP induction. Similarly, also bone marrow-derived macrophages (BMDM) exclusively targeted L.m. by PINCA as they completely failed to induce LAP because of insufficient production of ROS through CYBB, in part, due to low expression of some CYBB complex subunits. Priming of BMDM with proinflammatory cytokines such as TNF and IFNG/IFNγ increased ROS production by CYBB and endowed them with the ability to target L.m. by LAP. Targeting of L.m. by LAP remained relatively rare, though, preventing LAP from substantially contributing to the anti-listerial activity of BMDM. Similar to LAP, the targeting of L.m.-containing phagosomes by PINCA promoted their fusion with lysosomes. Surprisingly, however, this did not substantially contribute to anti-listerial activity of BMDM. Thus, in contrast to LAP, PINCA does not have clear anti-listerial function suggesting that the two different non-canonical autophagy pathways targeting L.m. may have discrete functions.Abbreviations: actA/ActA: actin assembly-inducing protein A; ATG: autophagy-related; BMDM: Bone marrow-derived macrophages; CALCOCO2/NDP52: calcium-binding and coiled-coil domain-containing protein 2; CYBA/p22phox: cytochrome b-245 light chain; CYBB/NOX2: cytochrome b(558) subunit beta; E. coli: Escherichia coli; IFNG/IFNγ: interferon gamma; L.m.: Listeria monocytogenes; LAP: LC3-associated phagocytosis; LGALS: galectin; LLO: listeriolysin O; MAP1LC3/LC3: microtubule-associated protein 1 light chain 3; NCF1/p47phox: neutrophil cytosol factor 1; NCF2/p67phox: neutrophil cytosol factor 2; NCF4/p67phox: neutrophil cytosol factor 4; Peritoneal macrophages: PM; PINCA: pore-forming toxin-induced non-canonical autophagy; plc/PLC: 1-phosphatidylinositol phosphodiesterase; PMA: phorbol 12-myristate 13-acetate; RB1CC1/FIP200: RB1-inducible coiled-coil protein 1; ROS: reactive oxygen species; S. aureus: Staphylococcus aureus; S. flexneri: Shigella flexneri; SQSTM1/p62: sequestosome 1; S. typhimurium: Salmonella typhimurium; T3SS: type III secretion system; TNF: tumor necrosis factor; ULK: unc-51 like autophagy activating kinase; PM: peritoneal macrophages; WT: wild type.


Asunto(s)
Autofagia , Listeria monocytogenes , Autofagia/fisiología , Escherichia coli/metabolismo , Listeria monocytogenes/metabolismo , Macrófagos/metabolismo , Proteínas Asociadas a Microtúbulos/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Staphylococcus aureus
6.
Front Cell Dev Biol ; 9: 716406, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34557488

RESUMEN

Reactive oxygen species (ROS), such as the superoxide anion or hydrogen peroxide, have been established over decades of research as, on the one hand, important and versatile molecules involved in a plethora of homeostatic processes and, on the other hand, as inducers of damage, pathologies and diseases. Which effects ROS induce, strongly depends on the cell type and the source, amount, duration and location of ROS production. Similar to cellular pH and calcium levels, which are both strictly regulated and only altered by the cell when necessary, the redox balance of the cell is also tightly regulated, not only on the level of the whole cell but in every cellular compartment. However, a still widespread view present in the scientific community is that the location of ROS production is of no major importance and that ROS randomly diffuse from their cellular source of production throughout the whole cell and hit their redox-sensitive targets when passing by. Yet, evidence is growing that cells regulate ROS production and therefore their redox balance by strictly controlling ROS source activation as well as localization, amount and duration of ROS production. Hopefully, future studies in the field of redox biology will consider these factors and analyze cellular ROS more specifically in order to revise the view of ROS as freely flowing through the cell.

7.
ACS Biomater Sci Eng ; 7(9): 4545-4556, 2021 09 13.
Artículo en Inglés | MEDLINE | ID: mdl-34415718

RESUMEN

Scaffold-mediated tissue engineering has become a golden solution for the regeneration of damaged bone tissues that lack self-regeneration capability. A successful scaffold in bone tissue engineering comprises a multitude of suitable biological, microarchitectural, and mechanical properties acting as different signaling cues for the cells to mediate the new tissue formation. Therefore, careful design of bioactive scaffold macro- and microstructures in multiple length scales and biophysical properties fulfilling the tissue repair demands are necessary yet challenging to achieve. Herein, we have developed an antibacterial and biocompatible silica-silk fibroin (SF) gel-based ink through novel yet simple chemical approaches of sol-gel and self-assembly followed by processing the obtained gels as three-dimensional (3D) hybrid aerogel-based scaffolds exploiting the advanced materials design approaches of micro-extrusion-based 3D printing, and directional freeze-casting/drying approaches. As the main constituent of the hybrid biocompatible scaffold of this study, we used the SF extracted from Bombyx mori silkworm cocoon. However, to increase the cell responsivity and bactericidal efficiency of the final scaffold, thiol-ended antimicrobial and cell adhesive peptide sequence (SH-CM-RGD) was conjugated to silica-SF hybrid gels via covalent attachment using a spacer molecule through either preprint (prior to sol-gel) or during the post-printing steps on the previously printed silica-SF gel. In the next step, the hybrid Silica-SF-CM-RGD hydrogel ink was 3D-printed into the construct with interconnected porous structure with hierarchically organized porosity and a combination of several promising properties. Namely, due to the covalent linkage of the antibacterial peptide to the SF, the scaffold shows potent bactericidal efficiency toward Gram-positive and Gram-negative bacteria. Moreover, nanostructured silica components in the 3D-printed composites could intertwine with SF-CM-RGD to support the mechanical properties in the final scaffold and the final osteoconductivity of the scaffold. This study supports the promising properties of 3D-printed silica-SF-based hybrid aerogels constructs for repairing bone defect.


Asunto(s)
Fibroínas , Nanoestructuras , Antibacterianos/farmacología , Biomimética , Bacterias Gramnegativas , Bacterias Grampositivas , Hidrogeles , Péptidos , Porosidad , Impresión Tridimensional , Dióxido de Silicio , Andamios del Tejido
8.
Front Immunol ; 12: 633629, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33868252

RESUMEN

Although the crucial role of professional phagocytes for the clearance of S. aureus infections is well-established, several studies indicate an adverse role of leukocytes in the dissemination of S. aureus during infection. Since only little is known about macrophages in this context, we analyzed the role of macrophages, and in particular reactive oxygen species deficiency, for the seeding of S. aureus metastases. Infection of bone marrow-derived macrophages (BMDM) with S. aureus revealed that NADPH oxidase 2 (NOX2-) deficient, but not NOX1- or NOX4-deficient, BMDM failed to clear intracellular S. aureus. Despite of larger intracellular bacterial burden, NOX2-deficient BMDM showed significantly improved survival. Intravenous injection of mice with in vitro-infected BMDMs carrying intracellular viable S. aureus led to higher bacterial loads in kidney and liver of mice compared to injection with plain S. aureus. An even higher frequency of liver abscesses was observed in mice infected with S. aureus-loaded nox2-/- BMDM. Thus, the improved intracellular survival of S. aureus and improved viability of NOX2-deficient BMDM is associated with an aggravated metastatic dissemination of S. aureus infection. A combination of vancomycin and the intracellularly active antibiotic rifampicin led to complete elimination of S. aureus from liver within 48 h, which was not achieved with vancomycin treatment alone, underscoring the impact of intracellular S. aureus on the course of disease. The results of our study indicate that intracellular S. aureus carried by macrophages are sufficient to establish a systemic infection. This suggests the inclusion of intracellularly active antibiotics in the therapeutic regimen of invasive S. aureus infections, especially in patients with NADPH oxidase deficiencies such as chronic granulomatous disease.


Asunto(s)
Macrófagos/microbiología , Viabilidad Microbiana , NADPH Oxidasa 2/genética , Índice de Severidad de la Enfermedad , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus/fisiología , Animales , Femenino , Eliminación de Gen , Ratones , Ratones Endogámicos C57BL , Especies Reactivas de Oxígeno/análisis , Infecciones Estafilocócicas/inmunología , Staphylococcus aureus/patogenicidad
9.
Antioxidants (Basel) ; 10(2)2021 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-33669824

RESUMEN

Reactive oxygen species (ROS) are a chemically defined group of reactive molecules derived from molecular oxygen. ROS are involved in a plethora of processes in cells in all domains of life, ranging from bacteria, plants and animals, including humans. The importance of ROS for macrophage-mediated immunity is unquestioned. Their functions comprise direct antimicrobial activity against bacteria and parasites as well as redox-regulation of immune signaling and induction of inflammasome activation. However, only a few studies have performed in-depth ROS analyses and even fewer have identified the precise redox-regulated target molecules. In this review, we will give a brief introduction to ROS and their sources in macrophages, summarize the versatile roles of ROS in direct and indirect antimicrobial immune defense, and provide an overview of commonly used ROS probes, scavengers and inhibitors.

10.
Nat Commun ; 11(1): 2709, 2020 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-32483169

RESUMEN

Aberrant immune responses including reactive phagocytes are implicated in the etiology of age-related macular degeneration (AMD), a major cause of blindness in the elderly. The translocator protein (18 kDa) (TSPO) is described as a biomarker for reactive gliosis, but its biological functions in retinal diseases remain elusive. Here, we report that tamoxifen-induced conditional deletion of TSPO in resident microglia using Cx3cr1CreERT2:TSPOfl/fl mice or targeting the protein with the synthetic ligand XBD173 prevents reactivity of phagocytes in the laser-induced mouse model of neovascular AMD. Concomitantly, the subsequent neoangiogenesis and vascular leakage are prevented by TSPO knockout or XBD173 treatment. Using different NADPH oxidase-deficient mice, we show that TSPO is a key regulator of NOX1-dependent neurotoxic ROS production in the retina. These data define a distinct role for TSPO in retinal phagocyte reactivity and highlight the protein as a drug target for immunomodulatory and antioxidant therapies for AMD.


Asunto(s)
NADPH Oxidasa 1/genética , Neovascularización Patológica/genética , Fagocitos/metabolismo , Receptores de GABA/genética , Degeneración Macular Húmeda/genética , Animales , Línea Celular , Regulación de la Expresión Génica/efectos de los fármacos , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Microglía/efectos de los fármacos , Microglía/metabolismo , NADPH Oxidasa 1/metabolismo , Neovascularización Patológica/metabolismo , Fagocitos/efectos de los fármacos , Purinas/farmacología , Especies Reactivas de Oxígeno/metabolismo , Receptores de GABA/metabolismo , Transducción de Señal/efectos de los fármacos , Transducción de Señal/genética , Degeneración Macular Húmeda/metabolismo
11.
Tetrahedron Lett ; 61(40)2020 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-34334832

RESUMEN

With an inwardly directed reactive center and a well-defined binding pocket, Au(I) functionalized resorcin[4]arene cavitands have been shown to catalyze molecular transformations. The reactivity profiles that emerge differ from other Au(I) catalysts. The added constraint of a binding pocket gives rise to the possibility that the substrates might have to fit into the resorcinarene pocket; our hypothesis is that substrates that match the available space have different reaction outcomes than those that do not. Herein we report on the intramolecular cyclization of alkyne-aromatic substrates with variable alkynes and aromatic composition. We see that scaffold size most drastically dictates reactivity, especially when the substrate's features are particularly designed. The results of these experiments add to the veritable goldmine of information about the selectivity in catalysis that cavitands offer.

12.
Semin Cell Dev Biol ; 101: 68-76, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-31029766

RESUMEN

Phagocytes ingest, kill and degrade invading microbes in a process called phagocytosis. LC3-associated phagocytosis (LAP) combines the molecular machinery of phagocytosis with that of autophagy, the cellular pathway for ingestion of cytoplasmic components, resulting in the eponymous association of 'microtubule-associated proteins 1 A/1B light chain 3' (LC3) with the phagosomal membrane. The LC3-decorated phagosomes, or LAPosomes, show enhanced fusion with lysosomes resulting in enhanced killing and degradation of contained pathogens. Thus, LAP is a particularly microbicidal pathway. In this review, we discuss the molecular mechanisms involved in induction and execution of LAP and its crucial role in antimicrobial immunity against bacteria, fungi and parasites. As LAP has only recently been defined, we also point out the key open questions that remain to be answered.


Asunto(s)
Proteínas Asociadas a Microtúbulos/inmunología , Fagocitosis/inmunología , Fagosomas/inmunología , Animales , Humanos , Lisosomas/inmunología , Fagosomas/microbiología
13.
J Vis Exp ; (153)2019 11 09.
Artículo en Inglés | MEDLINE | ID: mdl-31762462

RESUMEN

Macrophages are phagocytic cells specialized in detecting molecules of non-self origin. To this end, they are equipped with a large array of pattern recognition receptors (PRRs). Unfortunately, this also makes macrophages particularly challenging to transfect as the transfection reagent and the transfected nucleic acids are often recognized by the PRRs as non-self. Therefore, transfection often results in macrophage activation and degradation of the transfected nucleic acids or even in suicide of the macrophages. Here, we describe a protocol that allows highly efficient transfection of murine primary macrophages such as peritoneal macrophages (PM) and bone marrow-derived macrophages (BMDM) with mRNA in vitro transcribed from DNA templates such as plasmids. With this simple protocol, transfection rates of about 50-65% for PM and about 85% for BMDM are achieved without cytotoxicity or immunogenicity observed. We describe in detail the generation of mRNA for transfection from DNA constructs such as plasmids and the transfection procedure.


Asunto(s)
Macrófagos/metabolismo , Transcripción Genética , Transfección/métodos , Animales , Activación de Macrófagos , Macrófagos/inmunología , Ratones , Plásmidos/genética , ARN Mensajero/genética
14.
Sci Signal ; 12(568)2019 02 12.
Artículo en Inglés | MEDLINE | ID: mdl-30755476

RESUMEN

A major function of macrophages during infection is initiation of the proinflammatory response, leading to the secretion of cytokines that help to orchestrate the immune response. Here, we identify reactive oxygen species (ROS) as crucial mediators of proinflammatory signaling leading to cytokine secretion in Listeria monocytogenes-infected macrophages. ROS produced by NADPH oxidases (Noxes), such as Nox2, are key components of the macrophage response to invading pathogens; however, our data show that the ROS that mediated proinflammatory signaling were produced by mitochondria (mtROS). We identified the inhibitor of κB (IκB) kinase (IKK) complex regulatory subunit NEMO [nuclear factor κB (NF-κB) essential modulator] as a target for mtROS. Specifically, mtROS induced intermolecular covalent linkage of NEMO through disulfide bonds formed by Cys54 and Cys347, which was essential for activation of the IKK complex and subsequent signaling through the extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) and NF-κB pathways that eventually led to the secretion of proinflammatory cytokines. We thus identify mtROS-dependent disulfide linkage of NEMO as an essential regulatory step of the proinflammatory response of macrophages to bacterial infection.


Asunto(s)
Citocinas/metabolismo , Mediadores de Inflamación/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Mitocondrias/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Animales , Cisteína/química , Cisteína/metabolismo , Disulfuros/química , Disulfuros/metabolismo , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Interacciones Huésped-Patógeno , Péptidos y Proteínas de Señalización Intracelular/química , Listeria monocytogenes/fisiología , Macrófagos/metabolismo , Macrófagos/microbiología , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , NADPH Oxidasa 2/genética , NADPH Oxidasa 2/metabolismo , FN-kappa B/metabolismo , Transducción de Señal
15.
Nat Commun ; 10(1): 688, 2019 02 08.
Artículo en Inglés | MEDLINE | ID: mdl-30737374

RESUMEN

Corticosteroids are host-directed drugs with proven beneficial effect on survival of tuberculosis (TB) patients, but their precise mechanisms of action in this disease remain largely unknown. Here we show that corticosteroids such as dexamethasone inhibit necrotic cell death of cells infected with Mycobacterium tuberculosis (Mtb) by facilitating mitogen-activated protein kinase phosphatase 1 (MKP-1)-dependent dephosphorylation of p38 MAPK. Characterization of infected mixed lineage kinase domain-like (MLKL) and tumor necrosis factor receptor 1 (TNFR1) knockout cells show that the underlying mechanism is independent from TNFα-signaling and necroptosis. Our results link corticosteroid function and p38 MAPK inhibition to abrogation of necrotic cell death mediated by mitochondrial membrane permeability transition, and open new avenues for research on novel host-directed therapies (HDT).


Asunto(s)
Corticoesteroides/farmacología , Membranas Mitocondriales/efectos de los fármacos , Membranas Mitocondriales/metabolismo , Mycobacterium tuberculosis/efectos de los fármacos , Mycobacterium tuberculosis/metabolismo , Dexametasona/farmacología , Humanos , Fosforilación/efectos de los fármacos , Receptores Tipo I de Factores de Necrosis Tumoral/genética , Receptores Tipo I de Factores de Necrosis Tumoral/metabolismo , Transducción de Señal/genética , Transducción de Señal/fisiología , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo
16.
Autophagy ; 14(8): 1462-1464, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29923444

RESUMEN

The macroautophagic/autophagic machinery cannot only target cell-endogenous components but also intracellular pathogenic bacteria such as Listeria monocytogenes. Listeria are targeted both by canonical autophagy and by a noncanonical form of autophagy referred to as LC3-associated phagocytosis (LAP). The molecular mechanisms involved and whether these processes contribute to anti-listerial immunity or rather provide Listeria with a replicative niche for persistent infection, however, remained unknown. Recently, using an in vivo mouse infection model, we have been able to demonstrate that Listeria in tissue macrophages are targeted exclusively by LAP. Furthermore, our data show that LAP is required for killing of Listeria by macrophages and thereby contributes to anti-listerial immunity of mice, whereas canonical autophagy is completely dispensable. Moreover, we have elucidated the molecular mechanisms that trigger LAP of Listeria and identified the integrin ITGAM-ITGB2/Mac-1/CR3/integrin αMß2 as the receptor that initiates LAP in response to Listeria infection.


Asunto(s)
Autofagia , Listeria monocytogenes , Animales , Antígenos CD18 , Antígeno de Macrófago-1 , Ratones , Fagocitosis
17.
Cell Host Microbe ; 23(3): 324-337.e5, 2018 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-29544096

RESUMEN

The intracellular pathogen Listeria monocytogenes (L.m.) is targeted by the autophagic machinery, but the molecular mechanisms involved and consequences for anti-listerial immunity remain enigmatic. Here, we demonstrate that L.m. infection of macrophages in vivo exclusively evokes LC3-associated phagocytosis (LAP), but not canonical autophagy, and that targeting of L.m. by LAP is required for anti-listerial immunity. The pathway leading to LAP induction in response to L.m. infection emanates from the ß2 integrin Mac-1 (CR3, integrin αMß2), a receptor recognizing diverse microbial ligands. Interaction of L.m. with Mac-1 induces acid sphingomyelinase-mediated changes in membrane lipid composition that facilitate assembly and activation of the phagocyte NAPDH oxidase Nox2. Nox2-derived reactive oxygen species then trigger LC3 recruitment to L.m.-containing phagosomes by LAP. By promoting fusion of L.m.-containing phagosomes with lysosomes, LAP increases exposure of L.m. to bactericidal acid hydrolases, thereby enhancing anti-listerial activity of macrophages and immunity of mice.


Asunto(s)
Antígenos CD18/inmunología , Interacciones Huésped-Patógeno/inmunología , Listeria monocytogenes/inmunología , Listeriosis/inmunología , Antígeno de Macrófago-1/inmunología , Fagocitosis , Animales , Autofagia , Modelos Animales de Enfermedad , Listeria monocytogenes/patogenicidad , Lisosomas , Macrófagos/inmunología , Ratones , Ratones Endogámicos C57BL , NADPH Oxidasa 2/metabolismo , Fagosomas , Especies Reactivas de Oxígeno/metabolismo , Esfingomielina Fosfodiesterasa , Factores de Virulencia
18.
Tetrahedron Lett ; 59(37): 3393-3396, 2018 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-31105350

RESUMEN

The synthesis and properties of a variety of substituted BODIPY diesters is presented. We find that certain substitution patterns afford appreciable yields of the target compounds and that electronic effects result in predicable differential fluorescent behavior. Challenges to further water solubilize these dyes and/or provide new points of attachment for biological tagging remain, these strategies are discussed.

19.
Bioorg Med Chem Lett ; 27(13): 2953-2956, 2017 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-28512029

RESUMEN

Upper rim phosphonic acid functionalized calix[4]arene affects selective transport of multiple molecular payloads through a liquid membrane. The secret is in the attachment of a receptor-complementary handle to the payload. We find that the trimethylammonium ethylene group present in choline is one of several general handles for the transport of drug and drug-like species. Herein we compare the effect of handle variation against the transport of serotonin and dopamine. We find that several ionizable amine termini handles are sufficient for transport and identify two ideal candidates. Their performance is significantly enhanced in HEPES buffered solutions. This inquiry completes a series of 3 studies aimed at optimization of this strategy. In completion a new approach towards synthetic receptor mediated selective small molecule transport has emerged; future work in vesicular and cellular systems will follow.


Asunto(s)
Calixarenos/farmacología , Colina/metabolismo , Dopamina/metabolismo , Neurotransmisores/farmacología , Serotonina/metabolismo , Transporte Biológico/efectos de los fármacos , Calixarenos/síntesis química , Calixarenos/química , Colina/química , Relación Dosis-Respuesta a Droga , Estructura Molecular , Neurotransmisores/síntesis química , Neurotransmisores/química , Relación Estructura-Actividad
20.
Hepatology ; 66(1): 252-265, 2017 07.
Artículo en Inglés | MEDLINE | ID: mdl-28318036

RESUMEN

Use of adeno-associated viral (AAV) vectors for liver-directed gene therapy has shown considerable success, particularly in patients with severe hemophilia B. However, the high vector doses required to reach therapeutic levels of transgene expression caused liver inflammation in some patients that selectively destroyed transduced hepatocytes. We hypothesized that such detrimental immune responses can be avoided by enhancing the efficacy of AAV vectors in hepatocytes. Because autophagy is a key liver response to environmental stresses, we characterized the impact of hepatic autophagy on AAV infection. We found that AAV induced mammalian target of rapamycin (mTOR)-dependent autophagy in human hepatocytes. This cell response was critically required for efficient transduction because under conditions of impaired autophagy (pharmacological inhibition, small interfering RNA knockdown of autophagic proteins, or suppression by food intake), recombinant AAV-mediated transgene expression was markedly reduced, both in vitro and in vivo. Taking advantage of this dependence, we employed pharmacological inducers of autophagy to increase the level of autophagy. This resulted in greatly improved transduction efficiency of AAV vectors in human and mouse hepatocytes independent of the transgene, driving promoter, or AAV serotype and was subsequently confirmed in vivo. Specifically, short-term treatment with a single dose of torin 1 significantly increased vector-mediated hepatic expression of erythropoietin in C57BL/6 mice. Similarly, coadministration of rapamycin with AAV vectors resulted in markedly enhanced expression of human acid-α-glucosidase in nonhuman primates. CONCLUSION: We identified autophagy as a pivotal cell response determining the efficiency of AAVs intracellular processing in hepatocytes and thus the outcome of liver-directed gene therapy using AAV vectors and showed in a proof-of-principle study how this virus-host interaction can be employed to enhance efficacy of this vector system. (Hepatology 2017;66:252-265).


Asunto(s)
Autofagia/genética , Dependovirus/genética , Terapia Genética/métodos , Hepatocitos/citología , Animales , Células Cultivadas , Modelos Animales de Enfermedad , Femenino , Técnicas de Transferencia de Gen , Vectores Genéticos , Humanos , Ratones , Ratones Endogámicos C57BL , Distribución Aleatoria , Transducción Genética
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...