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1.
J Public Health (Oxf) ; 46(2): e230-e239, 2024 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-38282109

RESUMEN

BACKGROUND: E-cigarettes have emerged as popular products, especially for younger populations. However, concerns regarding health effects exist and there is a notable gap in understanding the prevalence and nature of adverse events. This study aims to examine the rate of adverse events in individuals who use e-cigarettes in a large sample. METHODS: A cross-sectional survey was conducted with a sample of 4695 current and former e-cigarette users with a median age of 34 years. The survey collected data on e-cigarette use, adverse events experienced, product characteristics, related behaviors, sociodemographic factors and presence of medical comorbidities. Statistical analyses were conducted using Pearson's chi-squared tests and logistic regression. RESULTS: A total of 78.9% of respondents reported experiencing an adverse event within 6 h of using a vaping device, with the most common events being headache, anxiety and coughing. Product characteristics and related behaviors significantly influenced the risk of adverse events. There were also sociodemographic disparities, with Hispanic respondents and those with at least college-level education reporting higher rates of adverse events. CONCLUSIONS: Our study found a high rate of adverse events among e-cigarette users. We identified that certain e-cigarette product characteristics, behaviors and medical comorbidities significantly increased the risk of these events.


Asunto(s)
Sistemas Electrónicos de Liberación de Nicotina , Vapeo , Humanos , Masculino , Femenino , Estudios Transversales , Adulto , Vapeo/efectos adversos , Vapeo/epidemiología , Factores de Riesgo , Persona de Mediana Edad , Adulto Joven , Sistemas Electrónicos de Liberación de Nicotina/estadística & datos numéricos , Adolescente , Encuestas y Cuestionarios , Anciano
2.
medRxiv ; 2023 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-37745540

RESUMEN

Haloperidol is an anti-psychotic used for the treatment of schizophrenia or Tourette disorder. Here we report, by studying three large administrative health insurance databases, that haloperidol use is associated with a reduced risk of developing rheumatoid arthritis. A meta-analysis revealed a 31% reduced hazard of incident rheumatoid arthritis among individuals with schizophrenia or Tourette disorder treated with haloperidol compared to those treated with other anti-psychotic drugs. These findings suggest a potential benefit of haloperidol in rheumatoid arthritis and provide a rationale for randomized controlled trials to provide causal insights.

3.
J Fluoresc ; 2023 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-37721707

RESUMEN

Natural drug functionalised silver (Ag) nanoparticles (NPs) have gained significant interest in pharmacology related applications due to their therapeutic efficiency. We have synthesised silver nanoparticle using hesperetin as a reducing and capping agent. This work aims to discuss the relevance of the hesperetin functionalised silver nanoparticles (H-AgNPs) in the field of nano-medicine. The article primarily investigates the anticancer activity of H-AgNPs and then their interactions with calf thymus DNA (ctDNA) through spectroscopic and thermodynamic techniques. The green synthesised H-AgNPs are stable, spherical in shape and size of 10 ± 3 nm average diameter. The complex formation of H-AgNPs with ctDNA was established by UV-Visible absorption, fluorescent dye displacement assay, isothermal calorimetry and viscosity measurements. The binding constants obtained from these experiments were consistently in the order of 104 Mol-1. The melting temperature analysis and FTIR measurements confirmed that the structural alterations of ctDNA by the presence of H-AgNPs are minimal. All the thermodynamic variables and the endothermic binding nature were acquired from ITC experiments. All these experimental outcomes reveal the formation of H-AgNPs-ctDNA complex, and the results consistently verify the minor groove binding mode of H-AgNPs. The binding constant and limit of detection of 1.8 µM found from the interaction studies imply the DNA detection efficiency of H-AgNPs. The cytotoxicity of H-AgNPs against A549 and L929 cell lines were determined by in vitro MTT cell viability assay and lactate dehydrogenase (LDH) assay. The cell viability and LDH enzyme release are confirmed that the H-AgNPs has high anticancer activity. Moreover, the calculated LD50 value for H-AgNPs against lung cancer cells is 118.49 µl/ml, which is a low value comparing with the value for fibroblast cells (269.35 µl/ml). In short, the results of in vitro cytotoxicity assays revealed that the synthesised nanoparticles can be considered in applications related to cancer treatments. Also, we have found that, H-AgNPs is a minor groove binder, and having high DNA detection efficiency.

4.
Sci Rep ; 13(1): 9045, 2023 06 03.
Artículo en Inglés | MEDLINE | ID: mdl-37270606

RESUMEN

The influence of nanoparticles inside the human body and their interactions with biological macromolecules need to be explored/studied prior to specific applications. The objective of this study is to find the potential of camptothecin functionalised silver nanoparticles (CMT-AgNPs) in biomedical applications. This article primarily investigates the binding stratagem of CMT-AgNPs with calf thymus DNA (ctDNA) through a series of spectroscopic and calorimetric methods and then analyses the anticancer activity and cytotoxicity of CMT-AgNPs. The nanoparticles were synthesized using a simple one pot method and characterized using UV-Visible, fourier transform infrared (FTIR) spectroscopy, X-ray diffraction and high-resolution transmission electron microscopy (HRTEM). The average size of CMT-AgNPs is 10 ± 2 nm. A group of experimental techniques such as UV-Visible spectrophotometry, fluorescence dye displacement assay, circular dichroism (CD) and viscosity analysis unravelled the typical groove binding mode of CMT-AgNPs with ctDNA. The CD measurement evidenced the minor conformational alterations of double helical structure of ctDNA in the presence of CMT-AgNPs. The information deduced from the isothermal titration calorimetry (ITC) experiment is that the binding was exothermic and spontaneous in nature. Moreover, all the thermodynamic binding parameters were extracted from the ITC data. The binding constants obtained from UV absorption experiments, fluorescence dye displacement studies and ITC were consistently in the order of 104 Mol-1. All these results validated the formation of CMT-AgNPs-ctDNA complex and the results unambiguously confirm the typical groove binding mode of CMT-AgNPs. An exhaustive in vitro MTT assay by CMT-AgNPs and CMT against A549, HT29, HeLa and L929 cell lines revealed the capability of CMT-AgNPs as a potential anticancer agent.


Asunto(s)
Neoplasias Pulmonares , Nanopartículas del Metal , Humanos , Camptotecina/farmacología , Plata/farmacología , Plata/química , Nanopartículas del Metal/química , Dicroismo Circular , Espectroscopía Infrarroja por Transformada de Fourier , Calorimetría , ADN/metabolismo , Neoplasias Pulmonares/tratamiento farmacológico , Extractos Vegetales/química , Antibacterianos/química
5.
medRxiv ; 2023 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-36993694

RESUMEN

Innate immune signaling through the NLRP3 inflammasome has been implicated in the pathogenesis of Alzheimer's disease (AD), the most prevalent form of dementia. We previously demonstrated that nucleoside reverse transcriptase inhibitors (NRTIs), drugs approved to treat HIV and hepatitis B infections, also inhibit inflammasome activation. Here we report that in humans, NRTI exposure was associated with a significantly lower incidence of AD in two of the largest health insurance databases in the United States. Treatment of aged 5xFAD mice (a mouse model of amyloid-ß deposition that expresses five mutations found in familial AD) with Kamuvudine-9 (K-9), an NRTI-derivative with enhanced safety profile, reduced Aß deposition and reversed their cognitive deficit by improving their spatial memory and learning performance to that of young wild-type mice. These findings support the concept that inflammasome inhibition could benefit AD and provide a rationale for prospective clinical testing of NRTIs or K-9 in AD.

7.
J Med Virol ; 94(10): 4792-4802, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35698816

RESUMEN

BACKGROUND: Accurate diagnosis of coronavirus disease 2019 is essential to limiting transmission within healthcare settings. The aim of this study was to identify patient demographic and clinical characteristics that could impact the clinical sensitivity of the nasopharyngeal severe acute respiratory syndrome coronavirus-2 (SARS-CoV2) reverse transcription polymerase chain reaction (RT-PCR) test. METHODS: We conducted a retrospective, matched case-control study of patients who underwent repeated nasopharyngeal SARS-CoV2 RT-PCR testing at a tertiary care academic medical center between March 1 and July 23, 2020. The primary endpoint was conversion from negative to positive PCR status within 14 days. We conducted conditional logistic regression modeling to assess the associations between demographic and clinical features and conversion to test positivity. RESULTS: Of 51,116 patients with conclusive SARS-CoV2 nasopharyngeal RT-PCR results, 97 patients converted from negative to positive within 14 days. We matched those patients 1:2 to 194 controls by initial test date. In multivariate analysis, clinical suspicion for a respiratory infection (adjusted odds ratio [aOR] 20.9, 95% confidence interval [CI]: 3.1-141.2) and lack of pulmonary imaging (aOR 4.7, 95% CI: 1.03-21.8) were associated with conversion, while a lower burden of comorbidities trended toward an increased odds of conversion (aOR 2.2, 95% CI: 0.9-5.3). CONCLUSIONS: Symptoms consistent with a respiratory infection, especially in relatively healthy individuals, should raise concerns about a clinical false-negative result. We have identified several characteristics that should be considered when creating institutional infection prevention guidelines in the absence of more definitive data and should be included in future studies.


Asunto(s)
COVID-19 , SARS-CoV-2 , COVID-19/diagnóstico , Prueba de COVID-19 , Estudios de Casos y Controles , Humanos , Reacción en Cadena de la Polimerasa , ARN Viral , Estudios Retrospectivos , SARS-CoV-2/genética
9.
Sci Immunol ; 6(66): eabi4493, 2021 Dec 03.
Artículo en Inglés | MEDLINE | ID: mdl-34860583

RESUMEN

Detection of microbial products by multiprotein complexes known as inflammasomes is pivotal to host defense against pathogens. Nucleotide-binding domain leucine-rich repeat (NLR) CARD domain containing 4 (NLRC4) forms an inflammasome in response to bacterial products; this requires their detection by NLR family apoptosis inhibitory proteins (NAIPs), with which NLRC4 physically associates. However, the mechanisms underlying sterile NLRC4 inflammasome activation, which is implicated in chronic noninfectious diseases, remain unknown. Here, we report that endogenous short interspersed nuclear element (SINE) RNAs, which promote atrophic macular degeneration (AMD) and systemic lupus erythematosus (SLE), induce NLRC4 inflammasome activation independent of NAIPs. We identify DDX17, a DExD/H box RNA helicase, as the sensor of SINE RNAs that licenses assembly of an inflammasome comprising NLRC4, NLR pyrin domain­containing protein 3, and apoptosis-associated speck-like protein­containing CARD and induces caspase-1 activation and cytokine release. Inhibiting DDX17-mediated NLRC4 inflammasome activation decreased interleukin-18 release in peripheral blood mononuclear cells of patients with SLE and prevented retinal degeneration in an animal model of AMD. Our findings uncover a previously unrecognized noncanonical NLRC4 inflammasome activated by endogenous retrotransposons and provide potential therapeutic targets for SINE RNA­driven diseases.


Asunto(s)
Proteínas Reguladoras de la Apoptosis/inmunología , Proteínas de Unión al Calcio/inmunología , ARN Helicasas DEAD-box/inmunología , Inflamasomas/inmunología , ARN/inmunología , Retroelementos/inmunología , Animales , Proteínas Reguladoras de la Apoptosis/deficiencia , Proteínas de Unión al Calcio/deficiencia , Células Cultivadas , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados
10.
Sci Adv ; 7(40): eabj3658, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34586848

RESUMEN

Long interspersed nuclear element-1 (L1)­mediated reverse transcription (RT) of Alu RNA into cytoplasmic Alu complementary DNA (cDNA) has been implicated in retinal pigmented epithelium (RPE) degeneration. The mechanism of Alu cDNA­induced cytotoxicity and its relevance to human disease are unknown. Here we report that Alu cDNA is highly enriched in the RPE of human eyes with geographic atrophy, an untreatable form of age-related macular degeneration. We demonstrate that the DNA sensor cGAS engages Alu cDNA to induce cytosolic mitochondrial DNA escape, which amplifies cGAS activation, triggering RPE degeneration via the inflammasome. The L1-extinct rice rat was resistant to Alu RNA­induced Alu cDNA synthesis and RPE degeneration, which were enabled upon L1-RT overexpression. Nucleoside RT inhibitors (NRTIs), which inhibit both L1-RT and inflammasome activity, and NRTI derivatives (Kamuvudines) that inhibit inflammasome, but not RT, both block Alu cDNA toxicity, identifying inflammasome activation as the terminal effector of RPE degeneration.

11.
Tob Prev Cessat ; 7: 32, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34017926

RESUMEN

INTRODUCTION: Concomitant with the popularization of vaping, vape shops have dramatically proliferated over the past years. This study assesses whether vape storefronts in California are significantly associated with density of different age groups, and whether this differs between tobacco storefronts or non-specific tobacco retailers. METHODS: Addresses for licensed tobacco retailers were obtained from the California Department of Tax and Fee Administration. Business names and addresses were used to obtain store categories cross-referenced from Yelp. Using a cross-sectional ecological design, stores categorized as 'Vape Shop' or 'Tobacco Shop' were geolocated and compared with age-related variables from the American Community Survey. Regression was conducted in R to determine relationships between age group concentration, in ventiles, and proportion of tracts with tobacco-specific or vape-specific stores. Geospatial visualization was conducted using ArcGIS. RESULTS: We found 848 vape shops, 820 tobacco shops, 419 categorized as both, and 20320 retailers with neither category. Overall, 1800 tobacco and/or vape shops were categorized in 1557 of California's 23194 census tracts. A positive linear association was found between ventiles of two age categories, 20-24 and 25-34 years, and proportion of tracts with vape-specific or tobacco-specific shops separately. CONCLUSIONS: Positive associations were found for ages 20-34 years but not for other ages, suggesting vape shops are strategically located in areas populated by young adults. Location-based targeting increases access, thereby increasing proportion of tobacco users, and could be a critical factor in e-cigarette uptake and use. Further study to identify additional age-related demographic characteristics among clientele of tobacco storefronts is warranted.

12.
Signal Transduct Target Ther ; 6(1): 149, 2021 04 14.
Artículo en Inglés | MEDLINE | ID: mdl-33850097

RESUMEN

Nonfibrillar amyloid-ß oligomers (AßOs) are a major component of drusen, the sub-retinal pigmented epithelium (RPE) extracellular deposits characteristic of age-related macular degeneration (AMD), a common cause of global blindness. We report that AßOs induce RPE degeneration, a clinical hallmark of geographic atrophy (GA), a vision-threatening late stage of AMD that is currently untreatable. We demonstrate that AßOs induce activation of the NLRP3 inflammasome in the mouse RPE in vivo and that RPE expression of the purinergic ATP receptor P2RX7, an upstream mediator of NLRP3 inflammasome activation, is required for AßO-induced RPE degeneration. Two classes of small molecule inflammasome inhibitors-nucleoside reverse transcriptase inhibitors (NRTIs) and their antiretrovirally inert modified analog Kamuvudines-both inhibit AßOs-induced RPE degeneration. These findings crystallize the importance of P2RX7 and NLRP3 in a disease-relevant model of AMD and identify inflammasome inhibitors as potential treatments for GA.


Asunto(s)
Péptidos beta-Amiloides/metabolismo , Degeneración Macular/tratamiento farmacológico , Epitelio Pigmentado de la Retina/metabolismo , Inhibidores de la Transcriptasa Inversa/farmacología , Péptidos beta-Amiloides/genética , Animales , Modelos Animales de Enfermedad , Humanos , Degeneración Macular/genética , Degeneración Macular/metabolismo , Masculino , Ratones , Ratones Noqueados
14.
Front Public Health ; 9: 628812, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33928062

RESUMEN

Introduction: College-aged youth are active on social media yet smoking-related social media engagement in these populations has not been thoroughly investigated. We sought to conduct an exploratory infoveillance study focused on geolocated data to characterize smoking-related tweets originating from California 4-year colleges on Twitter. Methods: Tweets from 2015 to 2019 with geospatial coordinates in CA college campuses containing smoking-related keywords were collected from the Twitter API stream and manually annotated for discussions about smoking product type, sentiment, and behavior. Results: Out of all tweets detected with smoking-related behavior, 46.7% related to tobacco use, 50.0% to marijuana, and 7.3% to vaping. Of these tweets, 46.1% reported first-person use or second-hand observation of smoking behavior. Out of 962 tweets with user sentiment, the majority (67.6%) were positive, ranging from 55.0% for California State University, Long Beach to 95.8% for California State University, Los Angeles. Discussion: We detected reporting of first- and second-hand smoking behavior on CA college campuses representing possible violation of campus smoking bans. The majority of tweets expressed positive sentiment about smoking behaviors, though there was appreciable variability between college campuses. This suggests that anti-smoking outreach should be tailored to the unique student populations of these college communities. Conclusion: Among tweets about smoking from California colleges, high levels of positive sentiment suggest that the campus climate may be less receptive to anti-smoking messages or adherence to campus smoking bans. Further research should investigate the degree to which this varies by campuses over time and following implementation of bans including validating using other sources of data.


Asunto(s)
Cannabis , Vapeo , Adolescente , Humanos , Los Angeles , Autoinforme , Nicotiana , Uso de Tabaco , Universidades , Adulto Joven
15.
Proc Natl Acad Sci U S A ; 118(6)2021 02 09.
Artículo en Inglés | MEDLINE | ID: mdl-33526699

RESUMEN

Alu retroelements propagate via retrotransposition by hijacking long interspersed nuclear element-1 (L1) reverse transcriptase (RT) and endonuclease activities. Reverse transcription of Alu RNA into complementary DNA (cDNA) is presumed to occur exclusively in the nucleus at the genomic integration site. Whether Alu cDNA is synthesized independently of genomic integration is unknown. Alu RNA promotes retinal pigmented epithelium (RPE) death in geographic atrophy, an untreatable type of age-related macular degeneration. We report that Alu RNA-induced RPE degeneration is mediated via cytoplasmic L1-reverse-transcribed Alu cDNA independently of retrotransposition. Alu RNA did not induce cDNA production or RPE degeneration in L1-inhibited animals or human cells. Alu reverse transcription can be initiated in the cytoplasm via self-priming of Alu RNA. In four health insurance databases, use of nucleoside RT inhibitors was associated with reduced risk of developing atrophic macular degeneration (pooled adjusted hazard ratio, 0.616; 95% confidence interval, 0.493-0.770), thus identifying inhibitors of this Alu replication cycle shunt as potential therapies for a major cause of blindness.


Asunto(s)
Elementos Alu/genética , Elementos de Nucleótido Esparcido Largo/genética , Degeneración Macular/genética , Pigmentos Retinianos/metabolismo , Animales , Citoplasma/genética , ADN Complementario/genética , Epitelio/metabolismo , Epitelio/patología , Humanos , Degeneración Macular/patología , Pigmentos Retinianos/biosíntesis , Retroelementos/genética , Transcripción Reversa/genética
16.
Invest Ophthalmol Vis Sci ; 61(10): 4, 2020 08 03.
Artículo en Inglés | MEDLINE | ID: mdl-32749462

RESUMEN

Purpose: Azidothymidine (AZT), a nucleoside reverse transcriptase inhibitor, possesses anti-inflammatory and anti-angiogenic activity independent of its ability to inhibit reverse transcriptase. The aim of this study was to evaluate the efficacy of 5'-glucuronyl azidothymidine (GAZT), an antiretrovirally inert hepatic clinical metabolite of AZT, in mouse models of retinal pigment epithelium (RPE) degeneration and choroidal neovascularization (CNV), hallmark features of dry and wet age-related macular degeneration (AMD), respectively. Methods: RPE degeneration was induced in wild-type (WT) C57BL/6J mice by subretinal injection of Alu RNA. RPE degeneration was assessed by fundus photography and confocal microscopy of zonula occludens-1-stained RPE flat mounts. Choroidal neovascularization was induced by laser injury in WT mice, and CNV volume was measured by confocal microscopy. AZT and GAZT were delivered by intravitreous injections. Inflammasome activation was monitored by western blotting for caspase-1 and by ELISA for IL-1ß in Alu RNA-treated bone marrow-derived macrophages (BMDMs). Results: GAZT inhibited Alu RNA-induced RPE degeneration and laser-induced CNV. GAZT also reduced Alu RNA-induced caspase-1 activation and IL-1ß release in BMDMs. Conclusions: GAZT possesses dual anti-inflammatory and anti-angiogenic properties and could be a viable treatment option for both forms of AMD.


Asunto(s)
Neovascularización Coroidal/tratamiento farmacológico , Modelos Animales de Enfermedad , Atrofia Geográfica/tratamiento farmacológico , Epitelio Pigmentado de la Retina/efectos de los fármacos , Inhibidores de la Transcriptasa Inversa/uso terapéutico , Zidovudina/análogos & derivados , Animales , Western Blotting , Caspasa 1/metabolismo , Neovascularización Coroidal/metabolismo , Ensayo de Inmunoadsorción Enzimática , Femenino , Atrofia Geográfica/metabolismo , Interleucina-1beta/metabolismo , Inyecciones Intravítreas , Macrófagos/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Microscopía Confocal , Inhibidores de la Transcriptasa Inversa/administración & dosificación , Zidovudina/administración & dosificación , Zidovudina/uso terapéutico , Proteína de la Zonula Occludens-1/metabolismo
17.
mBio ; 10(4)2019 07 23.
Artículo en Inglés | MEDLINE | ID: mdl-31337727

RESUMEN

Subversion of endoplasmic reticulum (ER) function is a feature shared by multiple intracellular bacteria and viruses, and in many cases this disruption of cellular function activates pathways of the unfolded protein response (UPR). In the case of infection with Brucella abortus, the etiologic agent of brucellosis, the unfolded protein response in the infected placenta contributes to placentitis and abortion, leading to pathogen transmission. Here we show that B. abortus infection of pregnant mice led to death of infected placental trophoblasts in a manner that depended on the VirB type IV secretion system (T4SS) and its effector VceC. The trophoblast death program required the ER stress-induced transcription factor CHOP. While NOD1/NOD2 expression in macrophages contributed to ER stress-induced inflammation, these receptors did not play a role in trophoblast death. Both placentitis and abortion were independent of apoptosis-associated Speck-like protein containing a caspase activation and recruitment domain (ASC). These studies show that B. abortus uses its T4SS to induce cell-type-specific responses to ER stress in trophoblasts that trigger placental inflammation and abortion. Our results suggest further that in B. abortus the T4SS and its effectors are under selection as bacterial transmission factors.IMPORTANCEBrucella abortus infects the placenta of pregnant cows, where it replicates to high levels and triggers abortion of the calf. The aborted material is highly infectious and transmits infection to both cows and humans, but very little is known about how B. abortus causes abortion. By studying this infection in pregnant mice, we discovered that B. abortus kills trophoblasts, which are important cells for maintaining pregnancy. This killing required an injected bacterial protein (VceC) that triggered an endoplasmic reticulum (ER) stress response in the trophoblast. By inhibiting ER stress or infecting mice that lack CHOP, a protein induced by ER stress, we could prevent death of trophoblasts, reduce inflammation, and increase the viability of the pups. Our results suggest that B. abortus injects VceC into placental trophoblasts to promote its transmission by abortion.


Asunto(s)
Brucella abortus/patogenicidad , Muerte Celular , Estrés del Retículo Endoplásmico , Placenta/microbiología , Trofoblastos/microbiología , Sistemas de Secreción Tipo IV/metabolismo , Animales , Femenino , Ratones , Ratones Endogámicos C57BL , Proteína Adaptadora de Señalización NOD1/genética , Proteína Adaptadora de Señalización NOD2/genética , Placenta/citología , Embarazo , Factor de Transcripción CHOP/genética , Trofoblastos/patología , Respuesta de Proteína Desplegada
18.
Nat Med ; 24(1): 50-61, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-29176737

RESUMEN

Geographic atrophy is a blinding form of age-related macular degeneration characterized by retinal pigmented epithelium (RPE) death; the RPE also exhibits DICER1 deficiency, resultant accumulation of endogenous Alu-retroelement RNA, and NLRP3-inflammasome activation. How the inflammasome is activated in this untreatable disease is largely unknown. Here we demonstrate that RPE degeneration in human-cell-culture and mouse models is driven by a noncanonical-inflammasome pathway that activates caspase-4 (caspase-11 in mice) and caspase-1, and requires cyclic GMP-AMP synthase (cGAS)-dependent interferon-ß production and gasdermin D-dependent interleukin-18 secretion. Decreased DICER1 levels or Alu-RNA accumulation triggers cytosolic escape of mitochondrial DNA, which engages cGAS. Moreover, caspase-4, gasdermin D, interferon-ß, and cGAS levels were elevated in the RPE in human eyes with geographic atrophy. Collectively, these data highlight an unexpected role of cGAS in responding to mobile-element transcripts, reveal cGAS-driven interferon signaling as a conduit for mitochondrial-damage-induced inflammasome activation, expand the immune-sensing repertoire of cGAS and caspase-4 to noninfectious human disease, and identify new potential targets for treatment of a major cause of blindness.


Asunto(s)
Atrofia Geográfica/enzimología , Inflamasomas/metabolismo , Nucleotidiltransferasas/metabolismo , Animales , ARN Helicasas DEAD-box/genética , Humanos , Interferón Tipo I/metabolismo , Ratones , Epitelio Pigmentado de la Retina/metabolismo , Ribonucleasa III/genética , Transducción de Señal
19.
Antimicrob Agents Chemother ; 59(11): 6717-24, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26282427

RESUMEN

A subset of bacterial pathogens, including the zoonotic Brucella species, are highly resistant against polymyxin antibiotics. Bacterial polymyxin resistance has been attributed primarily to the modification of lipopolysaccharide; however, it is unknown what additional mechanisms mediate high-level resistance against this class of drugs. This work identified a role for the Brucella melitensis gene bveA (BMEII0681), encoding a predicted esterase, in the resistance of B. melitensis to polymyxin B. Characterization of the enzymatic activity of BveA demonstrated that it is a phospholipase A1 with specificity for phosphatidylethanolamine (PE). Further, lipidomic analysis of B. melitensis revealed an excess of PE lipids in the bacterial membranes isolated from the bveA mutant. These results suggest that by lowering the PE content of the cell envelope, BveA increases the resistance of B. melitensis to polymyxin B. BveA was required for survival and replication of B. melitensis in macrophages and for persistent infection in mice. BveA family esterases are encoded in the genomes of the alphaproteobacterial species that coexist with the polymyxin-producing bacteria in the rhizosphere, suggesting that maintenance of a low PE content in the bacterial cell envelope may be a shared persistence strategy for association with plant and mammalian hosts.


Asunto(s)
Antibacterianos/farmacología , Brucella melitensis/efectos de los fármacos , Brucella melitensis/enzimología , Fosfolipasas A1/metabolismo , Fosfolípidos/metabolismo , Polimixinas/farmacología , Brucella melitensis/metabolismo , Farmacorresistencia Bacteriana , Fosfatidiletanolaminas/metabolismo , Fosfolipasas A1/genética
20.
Neural Netw ; 63: 66-78, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25499174

RESUMEN

The approach of applying a cascaded network consisting of radial basis function nodes and least square error minimization block to Compressed Sensing for recovery of sparse signals is analyzed in this paper to improve the computation time and convergence of an existing ANN based recovery algorithm. The proposed radial basis function-least square error projection cascade network for sparse signal Recovery (RASR) utilizes the smoothed L0 norm optimization, L2 least square error projection and feedback network model to improve the signal recovery performance over the existing CSIANN algorithm. The use of ANN architecture in the recovery algorithm gives a marginal reduction in computational time compared to an existing L0 relaxation based algorithm SL0. The simulation results and experimental evaluation of the algorithm performance are presented here.


Asunto(s)
Algoritmos , Compresión de Datos/métodos , Redes Neurales de la Computación , Retroalimentación
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