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1.
Redox Biol ; 63: 102758, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37245287

RESUMO

Ferroptosis is an iron dependent form of cell death, that is triggered by the discoordination of iron, lipids, and thiols. Its unique signature that distinguishes it from other forms of cell death is the formation and accumulation of lipid hydroperoxides, particularly oxidized forms of polyunsaturated phosphatidylethanolamines (PEs), which drives cell death. These readily undergo iron-catalyzed secondary free radical reactions leading to truncated products which retain the signature PE headgroup and which can readily react with nucleophilic moieties in proteins via their truncated electrophilic acyl chains. Using a redox lipidomics approach, we have identified oxidatively-truncated PE species (trPEox) in enzymatic and non-enzymatic model systems. Further, using a model peptide we demonstrate adduct formation with Cys as the preferred nucleophilic residue and PE(26:2) +2 oxygens, as one of the most reactive truncated PE-electrophiles produced. In cells stimulated to undergo ferroptosis we identified PE-truncated species with sn-2 truncations ranging from 5 to 9 carbons. Taking advantage of the free PE headgroup, we have developed a new technology using the lantibiotic duramycin, to enrich and identify the PE-lipoxidated proteins. Our results indicate that several dozens of proteins for each cell type, are PE-lipoxidated in HT-22, MLE, and H9c2 cells and M2 macrophages after they were induced to undergo ferroptosis. Pretreatment of cells with the strong nucleophile, 2-mercaptoethanol, prevented the formation of PE-lipoxidated proteins and blocked ferroptotic death. Finally, our docking simulations showed that the truncated PE species bound at least as good to several of the lantibiotic-identified proteins, as compared to the non-truncated parent molecule, stearoyl-arachidonoyl PE (SAPE), indicating that these oxidatively-truncated species favor/promote the formation of PEox-protein adducts. The identification of PEox-protein adducts during ferroptosis suggests that they are participants in the ferroptotic process preventable by 2-mercaptoethanol and may contribute to a point of no return in the ferroptotic death process.


Assuntos
Ferroptose , Humanos , Mercaptoetanol , Oxirredução , Morte Celular , Ferro/metabolismo , Peroxidação de Lipídeos
2.
Urologe A ; 58(5): 535-542, 2019 May.
Artigo em Alemão | MEDLINE | ID: mdl-30980089

RESUMO

The focus of this work is on aspects of the current management of recurrent nephrolithiasis in private practices and outpatient departments in Germany. We wanted to make a contribution to the epidemiological discourse as well as for an instrument for the self-reflection and complex classification of urolithiasis in everyday practice by a first-time determination of population-based, age- and gender-based data based on the full recording of urological diagnoses and treatments in the federal accounting setting. The analysis of the taken positions in this representative practice survey prove to some extent information and experience deficits in the handling of complicated nephrolithiasis. Therefor more than 90% of the interviewees demand a structured practical training initiative. In this context, nearly 65% of practices also support the establishment of regional consultation hours. A majority strongly welcomes the establishment of a National Register of Urolithiasis, but nearly 40% are skeptical about defining pending framework conditions.


Assuntos
Fidelidade a Diretrizes , Guias como Assunto , Nefrolitíase/epidemiologia , Prática Privada , Alemanha , Humanos , Cálculos Renais , Nefrolitíase/diagnóstico , Nefrolitíase/terapia , Inquéritos e Questionários
3.
Clin Exp Allergy ; 48(9): 1137-1146, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29781543

RESUMO

BACKGROUND: A predisposition to exacerbations is being recognized as a distinct phenotype with "previous exacerbations" representing the strongest clinical factor associated with future exacerbation. Thus, to identify additional novel biomarkers associated with asthma exacerbations, "past exacerbation status" must be included as a confounding factor. OBJECTIVE: This study aimed to characterize the clinical and biomarker features associated with asthma exacerbations in severe asthma. METHODS: We evaluated clinical parameters from 105 severe asthmatics yearly for 3 years, as well as their exacerbation status. We classified the subjects into 3 groups: (i) consistent non-exacerbators (CNE, subjects who did not experience any exacerbation over the 3-year period); (ii) consistent frequent exacerbators (CFE, subjects with frequent exacerbation, defined as those who had 2 or more exacerbations within 1 year, throughout the 3-year period); and (iii) intermittent exacerbators (IE). We conducted multivariate analysis for comparisons among the groups for multiple factors, including several Th2-related biomarkers, in addition to the "past exacerbation status." RESULTS: Thirty-nine subjects were classified as CNE, 15 as CFE, and 51 as IE. Frequent exacerbations in the previous year predicted exacerbations for the following year (P < .001). Among the several Th2-related biomarkers, only FeNO was associated with exacerbation status. When we analysed the data after the second visit, the impact of FeNO on predicting future exacerbation remained significant, even after considering the exacerbation status during the first year (P < .05). CONCLUSIONS AND CLINICAL RELEVANCE: Measurement of FeNO has a significant potential to predict future asthma exacerbation, which is independent of the "past exacerbation history."


Assuntos
Asma/epidemiologia , Adolescente , Adulto , Asma/diagnóstico , Biomarcadores , Criança , Pré-Escolar , Comorbidade , Progressão da Doença , Feminino , Seguimentos , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Óxido Nítrico , Fenótipo , Prognóstico , Testes de Função Respiratória , Índice de Gravidade de Doença , Inquéritos e Questionários , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Adulto Jovem
4.
Urologe A ; 57(5): 568-576, 2018 May.
Artigo em Alemão | MEDLINE | ID: mdl-29500474

RESUMO

Adjuvant therapy with different bacillus Calmette-Guérin (BCG) preparations is a well-established guideline-endorsed treatment for nonmuscle invasive bladder cancer (NMIBC). Our observational study demonstrates equality between BCG and mitomycin C (MMC) treatment based on the oncological outcome. However, there were significant toxicity differences with higher rates in the BCG treatment group. The potential adverse effects of BCG in terms of a BCGitis are controversially discussed regarding their occurrence. As such, we sought to retrospectively evaluate the incidence in 106 consecutive patients. The BCG group demonstrated minor adverse effects in 78.4% and major adverse effects in 43.3%-partially coincident. Moreover, the parallel MMC group showed in 34.7% respectively 1.4% adverse events-as expected distinctly lower. In the context of this clinical discussion, we refer to alternative treatment concepts. Our data show a high clinical relevance of the patient's primary comorbidity.


Assuntos
Antibióticos Antineoplásicos , Vacina BCG , Mitomicina , Neoplasias da Bexiga Urinária , Adjuvantes Imunológicos/uso terapêutico , Administração Intravesical , Antibióticos Antineoplásicos/uso terapêutico , Vacina BCG/uso terapêutico , Humanos , Mitomicina/uso terapêutico , Invasividade Neoplásica , Estudos Retrospectivos , Neoplasias da Bexiga Urinária/tratamento farmacológico
5.
Am J Community Psychol ; 61(3-4): 421-432, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29537648

RESUMO

Permanent supportive housing (PSH) is a widely-accepted solution to the challenge of chronic homelessness. While housing support and retention, physical health, and healthcare continue to be important for formerly homeless persons in PSH, "higher-order" and humanistic needs such as thriving have received less attention and as a result are less well understood in this population. One important indicator of thriving is the ability to establish and articulate life goals. This study utilizes longitudinal data from 421 formerly homeless adults prior to their move into PSH, and at 3-, 6- and 12-months after move-in (369 respondents completed all four interviews), to examine what life goals are articulated by this population and how those goals change over time. Prior to housing, most respondents articulated housing attainment as their primary life goal, whereas at follow-up interviews health goals, housing relocation, and financial goals became more prevalent. Aspirational goals (e.g., independence, self-improvement, artistic pursuits) were also common, but demonstrated a decrease over time in housing. Relationship goals remained common and consistent over time. Findings indicate that housing is a necessary, but perhaps not sufficient, step for improving thriving among formerly homeless adults. Implications for practice and future research are discussed.


Assuntos
Aspirações Psicológicas , Objetivos , Habitação , Pessoas Mal Alojadas , Feminino , Saúde , Humanos , Estudos Longitudinais , Los Angeles , Masculino , Pessoa de Meia-Idade , Serviço Social
6.
Leukemia ; 31(3): 602-613, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27538486

RESUMO

Apart from its unique histopathological appearance with rare tumor cells embedded in an inflammatory background of bystander cells, classical Hodgkin lymphoma (cHL) is characterized by an unusual activation of a broad range of signaling pathways involved in cellular activation. This includes constitutive high-level activity of nuclear factor-κB (NF-κB), Janus kinase/signal transducer and activator of transcription (JAK/STAT), activator protein-1 (AP-1) and interferon regulatory factor (IRF) transcription factors (TFs) that are physiologically only transiently activated. Here, we demonstrate that inactivation of the putative ubiquitin E3-ligase PDLIM2 contributes to this TF activation. PDLIM2 expression is lost at the mRNA and protein levels in the majority of cHL cell lines and Hodgkin and Reed-Sternberg (HRS) cells of nearly all cHL primary samples. This loss is associated with PDLIM2 genomic alterations, promoter methylation and altered splicing. Reconstitution of PDLIM2 in HRS cell lines inhibits proliferation, blocks NF-κB transcriptional activity and contributes to cHL-specific gene expression. In non-Hodgkin B-cell lines, small interfering RNA-mediated PDLIM2 knockdown results in superactivation of TFs NF-κB and AP-1 following phorbol 12-myristate 13-acetate (PMA) stimulation. Furthermore, expression of PDLIM2 is lost in anaplastic large cell lymphoma (ALCL) that shares key biological aspects with cHL. We conclude that inactivation of PDLIM2 is a recurrent finding in cHL and ALCL, promotes activation of inflammatory signaling pathways and thereby contributes to their pathogenesis.


Assuntos
Regulação Neoplásica da Expressão Gênica , Doença de Hodgkin/genética , Proteínas com Domínio LIM/genética , Linfoma Anaplásico de Células Grandes/genética , Proteínas dos Microfilamentos/genética , Sequência de Bases , Linhagem Celular Tumoral , Análise por Conglomerados , Metilação de DNA , Ativação Enzimática , Feminino , Inativação Gênica , Loci Gênicos , Doença de Hodgkin/metabolismo , Humanos , Proteínas com Domínio LIM/metabolismo , Linfoma Anaplásico de Células Grandes/metabolismo , Masculino , Proteínas dos Microfilamentos/metabolismo , Mutação , NF-kappa B/metabolismo , Regiões Promotoras Genéticas , Proteólise , Sítios de Splice de RNA , Fatores de Transcrição , Ubiquitina-Proteína Ligases
7.
Clin Exp Allergy ; 47(2): 190-199, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27562295

RESUMO

BACKGROUND: Asthma is associated with reduced systemic levels of l-arginine and increased asymmetric dimethylarginine (ADMA). This imbalance leads to nitric oxide synthase (NOS) uncoupling with reduced nitric oxide (NO) formation and greater oxidative and nitrosative stress. Whether this imbalance also occurs in bronchial epitheliumof asthmatics is unknown. OBJECTIVES: We used primary human bronchial epithelial cells (HBECs) from asthmatics and healthy controls to evaluate: (i) ADMA-mediated NOS uncoupling reduces epithelial production of NO and increases oxygen and nitrogen reactive species, and (ii) l-citrulline can reverse this mechanism by recoupling NOS, restoring NO production and reducing oxidative and nitrosative stress. RESULTS: In HBECsIL-13 and INFγ stimulated NOS2 and increased NOx levels. The addition of ADMA reduced NOx and increased H2 O2 levels (p<0.001). Treatment with l-citrulline (800, 1600 µm) rescued NOx when the l-arginine media concentration was 25 µm but failed to do so with higher concentrations (100 µm). Under reduced l-arginine media conditions, HBECs treated with l-citrulline increased the levels of argininosuccinate, an enzyme that metabolizes l-citrulline to l-arginine. l-citrulline prevented the ADMA-mediated increase in nitrotyrosine in HBECs in cells from asthmatics and controls. CONCLUSIONS AND CLINICAL RELEVANCE: Increasing ADMA reduces NO formation and increases oxidative and nitrosative stress in airway epithelial cells. l-citrulline supplementation restores NO formation, while preventing nitrosative stress. These results, suggest that l-citrulline supplementation may indeed be a powerful approach to restore airway NO production and may have a therapeutic potential in diseases in which there is a defective production of NO.


Assuntos
Arginina/análogos & derivados , Citrulina/farmacologia , Óxido Nítrico/metabolismo , Estresse Nitrosativo/efeitos dos fármacos , Oxirredução/efeitos dos fármacos , Mucosa Respiratória/efeitos dos fármacos , Mucosa Respiratória/metabolismo , Adulto , Arginina/farmacologia , Asma/metabolismo , Asma/fisiopatologia , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Feminino , Humanos , Peróxido de Hidrogênio , Masculino , Pessoa de Meia-Idade , Óxido Nítrico Sintase/metabolismo , Testes de Função Respiratória , Adulto Jovem
8.
J Hum Hypertens ; 31(2): 89-92, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27411300

RESUMO

The present study aims to examine the performance of the TONOPORT VI ambulatory blood pressure (BP) monitor in the inflation and deflation measurement methods, according to the European Society of Hypertension International Protocol revision 2010 (ESH-IP 2010). Systolic and diastolic blood pressures (SBP and DBP, respectively) of 33 subjects (23 female, 10 male) were sequentially measured and compared with reference measurements obtained by two observers using a standard mercury sphygmomanometer. The subjects were selected according to the recruitment instructions of the ESH-IP 2010. Three comparative readings were performed per subject. Among the 99 readings in the inflation measurement method were 92/94 (SBP/DBP) with differences ⩽5, 97/99 ⩽10 and 98/99 ⩽15 mm Hg. All of the 33 subjects had at least 2 out of 3 comparative readings with differences ⩽5 mm Hg and 0/0 of the subjects had no reading ⩽15 mm Hg. The validation of the deflation measurement method resulted in differences where 93/91 were ⩽5, 98/98 were ⩽10, and 99/99 were ⩽15 mm Hg. Thirty-two of the 33 subjects had at least 2 out of 3 comparative readings ⩽5 mm Hg and 0/0 of the subjects had no reading ⩽15 mm Hg. In conclusion, the TONOPORT VI, respectively, in the inflation and deflation measurement methods met all requirements of Part 1 and 2 of the ESH-IP 2010. Based on the study results, the TONOPORT VI can be recommended for BP measurements in adults.


Assuntos
Monitorização Ambulatorial da Pressão Arterial/instrumentação , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Oscilometria/instrumentação
9.
HNO ; 65(2): 117-124, 2017 Feb.
Artigo em Alemão | MEDLINE | ID: mdl-27815593

RESUMO

The impact of treating nasal obstruction in obstructive sleep apnea (OSA) patients is still intensively discussed at congresses. This is likely due to the highly conflicting results of nasal treatments in regard to restorative sleep on the one hand, and their influence on the severity of OSA on the other. Both conservative and surgical nasal treatments result in a highly significant improvement of sleep quality. Patients' sleep is more restorative, which has a huge impact on several quality of life parameters. In contrast, the impact of conservative and surgical nasal treatments on the severity of OSA measured using the apnea-hypopnea index is very limited, apart from rare exceptions. However, there are preliminary data indicating that successful nasal surgery may facilitate or enable nasal ventilation therapy by lowering the effective pressure.


Assuntos
Obstrução Nasal/diagnóstico , Obstrução Nasal/terapia , Procedimentos Cirúrgicos Nasais/métodos , Apneia Obstrutiva do Sono/diagnóstico , Apneia Obstrutiva do Sono/terapia , Terapia Combinada/métodos , Medicina Baseada em Evidências , Humanos , Obstrução Nasal/complicações , Apneia Obstrutiva do Sono/complicações , Resultado do Tratamento
10.
Sleep Breath ; 20(4): 1301-1311, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27179662

RESUMO

The German Society of Otorhinolaryngology, Head and Neck Surgery recently has released the abbreviated version of its scientific guideline "ENT-specific therapy of obstructive sleep apnoea (OSA) in adults", which has been updated in 2015 and can be found online at the Association of the Scientific Medical Societies (Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften, AWMF). A summary of the main recommendations is provided in this revised English version. All recommendations are based on a systematic literature research of articles published up until March 2014. Literature research followed the Cochrane Handbook for Systematic Literature Research to create Guidelines published by the German Cochrane Centre. Studies were evaluated with respect to their scientific value according to the recommendations of the Oxford Centre for Evidence-based Medicine, and grades of recommendation are provided regarding each intervention.


Assuntos
Comunicação Interdisciplinar , Colaboração Intersetorial , Otolaringologia , Otorrinolaringopatias/terapia , Apneia Obstrutiva do Sono/terapia , Adulto , Alemanha , Humanos , Otorrinolaringopatias/diagnóstico , Apneia Obstrutiva do Sono/diagnóstico
11.
HNO ; 64(5): 310-9, 2016 May.
Artigo em Alemão | MEDLINE | ID: mdl-27126293

RESUMO

The present S2e-guideline is an update of the former S2e-guideline "treatment of obstructive sleep apnea in adults". The update was performed on behalf of the German Society for Otorhinolaryngology, Head and Neck Surgery by its Sleep Medicine Task Force. The long version of the guideline is valid from 5.9.2015 to 5.9.2020 and has been available (guideline No. 017-069) since November 2015 on the official AWMF website.The subsequently presented short version of the guideline summarizes the essentials in a legible way. For further information, please refer to the long version.


Assuntos
Otolaringologia/normas , Procedimentos Cirúrgicos Otorrinolaringológicos/normas , Guias de Prática Clínica como Assunto , Apneia Obstrutiva do Sono/terapia , Medicina do Sono/normas , Adulto , Medicina Baseada em Evidências , Alemanha , Humanos , Apneia Obstrutiva do Sono/diagnóstico , Resultado do Tratamento
12.
Allergy ; 70(10): 1309-18, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26119467

RESUMO

BACKGROUND: Genome-wide association studies (GWASs) have identified various genes associated with asthma, yet, causal genes or single nucleotide polymorphisms (SNPs) remain elusive. We sought to dissect functional genes/SNPs for asthma by combining expression quantitative trait loci (eQTLs) and GWASs. METHODS: Cis-eQTL analyses of 34 asthma genes were performed in cells from human bronchial epithelial biopsy (BEC, n = 107) and from bronchial alveolar lavage (BAL, n = 94). RESULTS: For TSLP-WDR36 region, rs3806932 (G allele protective against eosinophilic esophagitis) and rs2416257 (A allele associated with lower eosinophil counts and protective against asthma) were correlated with decreased expression of TSLP in BAL (P = 7.9 × 10(-11) and 5.4 × 10(-4) , respectively) and BEC, but not WDR36. Surprisingly, rs1837253 (consistently associated with asthma) showed no correlation with TSLP expression levels. For ORMDL3-GSDMB region, rs8067378 (G allele protective against asthma) was correlated with decreased expression of GSDMB in BEC and BAL (P = 1.3 × 10(-4) and 0.04) but not ORMDL3. rs992969 in the promoter region of IL33 (A allele associated with higher eosinophil counts and risk for asthma) was correlated with increased expression of IL33 in BEC (P = 1.3 × 10(-6) ) but not in BAL. CONCLUSIONS: Our study illustrates cell-type-specific regulation of the expression of asthma-related genes documenting SNPs in TSLP, GSDMB, IL33, HLA-DQB1, C11orf30, DEXI, CDHR3, and ZBTB10 affect asthma risk through cis-regulation of its gene expression. Whenever possible, disease-relevant tissues should be used for transcription analysis. SNPs in TSLP may affect asthma risk through up-regulating TSLP mRNA expression or protein secretion. Further functional studies are warranted.


Assuntos
Asma/genética , Líquido da Lavagem Broncoalveolar , Células Epiteliais/metabolismo , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Locos de Características Quantitativas , Mucosa Respiratória/metabolismo , Alelos , Asma/imunologia , Asma/fisiopatologia , Líquido da Lavagem Broncoalveolar/citologia , Líquido da Lavagem Broncoalveolar/imunologia , Estudos de Casos e Controles , Mapeamento Cromossômico , Feminino , Estudos de Associação Genética , Humanos , Imunoglobulina E/imunologia , Masculino , Especificidade de Órgãos/genética , Polimorfismo de Nucleotídeo Único , Testes de Função Respiratória
13.
Phys Chem Chem Phys ; 17(24): 15903-11, 2015 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-26018838

RESUMO

Although tungsten trioxide (WO3) has been extensively studied since its electrochromic properties were first discovered, the mechanism responsible for the coloration or bleaching effect is still disputed. New insights into the coloration mechanism of electrochromic, nanocrystalline WO3 are provided in this paper by studying thin WO3 films combining the electrochemical and spectroscopic techniques. By employing in situ UV-Vis transmission spectroscopy at a fixed spectral band pass during electrochemical experiments, such as cyclic voltammetry, a two-step insertion process for both protons and lithium ions is identified, of which one step exhibits a significantly higher coloration efficiency than the other. To obtain a better understanding of the insertion process AxWO3 (A = H, Li,…) thin films were studied at different stages of intercalation using UV-Vis and X-ray photoelectron spectroscopy. The results show that the first step of the intercalation process represents the reduction from initial W(6+) to W(5+) and the second step the reduction of W(5+) to W(4+). We found that the blue coloration of this nanocrystalline tungsten trioxide is mainly due to the presence of W(4+) rather than that of W(5+).

14.
Rev. Méd. Clín. Condes ; 26(3): 267-275, mayo 2015. ilus, tab
Artigo em Espanhol | LILACS | ID: biblio-1129013

RESUMO

El asma es una enfermedad frecuente de fisiopatología compleja. El asma severa constituye aproximadamente el 5% de la población de asmáticos, sin embargo representa un desafío clínico y una carga sanitaria importante. Estudios recientes demuestran la existencia de fenotipos en todo el espectro de gravedad. La eosinofilia en esputo y sangre ha demostrado utilidad como marcador de inflamación Th-2 y de respuesta clínica a esteroides, sin embargo aún no existe mucho conocimiento sobre el asma no-eosinofílica. Los tratamientos actuales en asma se enfocan a estrategias de terapia escalonada según severidad, pero en pacientes con asma severa se requiere también del manejo multidisciplinario de las comorbilidades y la determinación del fenotipo, para aplicar terapias más especificas. El desarrollo acelerado de nuevos tratamientos en asma severa como consecuencia del mejor conocimiento de los distintos fenotipos ha ampliado el arsenal terapéutico para un enfrentamiento personalizado y específico en los pacientes con asma severa.


Asthma is a common disease of complex pathophysiology. Severe asthma accounts about 5% of asthma population, however represents a clinical challenge and a significant health burden. Recent studies show the existence of phenotypes through all the spectrum of severity. Eosinophilia in blood and sputum has proven as a useful marker of Th-2 inflammation and clinical steroid response, however there is still little knowledge about non-eosinophilic asthma. Current treatments for asthma are focused on step-up approaches according to severity, but severe asthma patients also require multidisciplinary management of comorbidities and phenotyping to apply more specific therapies. The fast development of new treatments in severe asthma as a result of better understanding of different phenotypes has broadened the therapeutic arsenal for a personalized and targeted management in severe asthma patients.


Assuntos
Humanos , Adulto , Asma/diagnóstico , Asma/terapia , Fenótipo , Asma/classificação , Asma/tratamento farmacológico , Biomarcadores , Comorbidade , Cooperação do Paciente , Diagnóstico Diferencial , Termoplastia Brônquica
15.
Chem Sci ; 6(8): 5076-5085, 2015 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-29308173

RESUMO

Myxopyronins are α-pyrone antibiotics produced by the terrestrial bacterium Myxococcus fulvus Mx f50 and possess antibacterial activity against Gram-positive and Gram-negative pathogens. They target the bacterial RNA polymerase (RNAP) "switch region" as non-competitive inhibitors and display no cross-resistance to the established RNAP inhibitor rifampicin. Recent analysis of the myxopyronin biosynthetic pathway led to the hypothesis that this secondary metabolite is produced from two separate polyketide parts, which are condensed by the stand-alone ketosynthase MxnB. Using in vitro assays we show that MxnB catalyzes a unique condensation reaction forming the α-pyrone ring of myxopyronins from two activated acyl chains in form of their ß-keto intermediates. MxnB is able to accept thioester substrates coupled to either N-acetylcysteamine (NAC) or a specific carrier protein (CP). The turnover rate of MxnB for substrates bound to CP was 12-fold higher than for NAC substrates, demonstrating the importance of protein-protein interactions in polyketide synthase (PKS) systems. The crystal structure of MxnB reveals the enzyme to be an unusual member of the ketosynthase group capable of binding and condensing two long alkyl chains bound to carrier proteins. The geometry of the two binding tunnels supports the biochemical data and allows us to propose an order of reaction, which is supported by the identification of novel myxopyronin congeners in the extract of the producer strain. Insights into the mechanism of this unique condensation reaction do not only expand our knowledge regarding the thiolase enzyme family but also opens up opportunities for PKS bioengineering to achieve directed structural modifications.

16.
Thorax ; 69(12): 1141-2, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24834924

RESUMO

UNLABELLED: A subpopulation of patients with asthma treated with maximal inhaled treatments is unable to maintain asthma control and requires additional therapy with oral corticosteroids (OCS); a subset of this population continues to have frequent exacerbations. Alternate treatment options are needed as daily use of OCS is associated with significant systemic adverse effects that affect many body systems and have a direct association with the dose and duration of OCS use. We compared the population demographics, medical conditions and efficacy responses of the OCS-dependent group from the DREAM study of mepolizumab with the group not managed with daily OCS. TRIAL REGISTRATION NUMBER: NCT01000506.


Assuntos
Corticosteroides/uso terapêutico , Antiasmáticos/uso terapêutico , Anticorpos Monoclonais Humanizados/uso terapêutico , Asma/tratamento farmacológico , Administração Oral , Adulto , Quimioterapia Combinada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
17.
Mucosal Immunol ; 7(5): 1175-85, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24518246

RESUMO

Severe refractory asthma is associated with enhanced nitrative stress. To determine the mechanisms for high nitrative stress in human severe asthma (SA), 3-nitrotyrosine (3NT) was compared with Th1 and Th2 cytokine expression. In SA, high 3NT levels were associated with high interferon (IFN)-γ and low interleukin (IL)-13 expression, both of which have been reported to increase inducible nitric oxide synthase (iNOS) in human airway epithelial cells (HAECs). We found that IL-13 and IFN-γ synergistically enhanced iNOS, nitrite, and 3NT, corresponding with increased H(2)O(2). Catalase inhibited whereas superoxide dismutase enhanced 3NT formation, supporting a critical role for H(2)O(2), but not peroxynitrite, in 3NT generation. Dual oxidase-2 (DUOX2), central to H(2)O(2) formation, was also synergistically induced by IL-13 and IFN-γ. The catalysis of nitrite and H(2)O(2) to nitrogen dioxide radical (NO(2)(•)) requires an endogenous peroxidase in this epithelial cell system. Thyroid peroxidase (TPO) was identified by microarray analysis ex vivo as a gene distinguishing HAEC of SA from controls. IFN-γ induced TPO in HAEC and small interfering RNA knockdown decreased nitrated tyrosine residues. Ex vivo, DUOX2, TPO, and iNOS were higher in SA and correlated with 3NT. Thus, a novel iNOS-DUOX2-TPO-NO(2)(•) metabolome drives nitrative stress in HAEC and likely in SA.


Assuntos
Asma/enzimologia , Asma/fisiopatologia , Metaboloma , Óxido Nítrico Sintase Tipo II/imunologia , Estresse Fisiológico , Células Th1/imunologia , Células Th2/imunologia , Adulto , Asma/imunologia , Feminino , Humanos , Interferon gama/farmacologia , Interleucina-13/farmacologia , Iodeto Peroxidase/metabolismo , Masculino , Análise em Microsséries , Sistema Respiratório/enzimologia , Sistema Respiratório/fisiopatologia , Índice de Gravidade de Doença , Estresse Fisiológico/efeitos dos fármacos , Células Th1/efeitos dos fármacos , Células Th2/efeitos dos fármacos , Adulto Jovem
18.
Mucosal Immunol ; 7(5): 1186-98, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24549277

RESUMO

Asthma is a common respiratory disease affecting ∼300 million people worldwide. Airway inflammation is thought to contribute to asthma pathogenesis, but the direct relationship between inflammation and airway hyperresponsiveness (AHR) remains unclear. This study investigates the role of inflammation in a steroid-insensitive, severe allergic airway disease model and in severe asthmatics stratified by inflammatory profile. First, we used the T-helper (T(H))-17 cells adoptive transfer mouse model of asthma to induce pulmonary inflammation, which was lessened by tumor necrosis factor (TNF)-α neutralization or neutrophil depletion. Although decreased airspace inflammation following TNFα neutralization and neutrophil depletion rescued lung compliance, neither intervention improved AHR to methacholine, and tissue inflammation remained elevated when compared with control. Further, sputum samples were collected and analyzed from 41 severe asthmatics. In severe asthmatics with elevated levels of sputum neutrophils, but low levels of eosinophils, increased inflammatory markers did not correlate with worsened lung function. This subset of asthmatics also had significantly higher levels of T(H)17-related cytokines in their sputum compared with severe asthmatics with other inflammatory phenotypes. Overall, this work suggests that lung compliance may be linked with cellular inflammation in the airspace, whereas T-cell-driven AHR may be associated with tissue inflammation and other pulmonary factors.


Assuntos
Asma/complicações , Inflamação/complicações , Pulmão/fisiologia , Adolescente , Adulto , Idade de Início , Idoso , Idoso de 80 Anos ou mais , Animais , Asma/imunologia , Asma/fisiopatologia , Hiper-Reatividade Brônquica/imunologia , Broncoconstritores/farmacologia , Criança , Citocinas/imunologia , Feminino , Humanos , Pulmão/efeitos dos fármacos , Pulmão/patologia , Masculino , Cloreto de Metacolina/farmacologia , Camundongos , Camundongos Transgênicos , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Escarro/imunologia
19.
Leukemia ; 27(6): 1381-90, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23257783

RESUMO

Myeloid cell leukemia-1 (MCL1) is an anti-apoptotic member of the BCL2 family that is deregulated in various solid and hematological malignancies. However, its role in the molecular pathogenesis of diffuse large B-cell lymphoma (DLBCL) is unclear. We analyzed gene expression profiling data from 350 DLBCL patient samples and detected that activated B-cell-like (ABC) DLBCLs express MCL1 at significantly higher levels compared with germinal center B-cell-like DLBCL patient samples (P=2.7 × 10(-10)). Immunohistochemistry confirmed high MCL1 protein expression predominantly in ABC DLBCL in an independent patient cohort (n=249; P=0.001). To elucidate molecular mechanisms leading to aberrant MCL1 expression, we analyzed array comparative genomic hybridization data of 203 DLBCL samples and identified recurrent chromosomal gains/amplifications of the MCL1 locus that occurred in 26% of ABC DLBCLs. In addition, aberrant STAT3 signaling contributed to high MCL1 expression in this subtype. Knockdown of MCL1 as well as treatment with the BH3-mimetic obatoclax induced apoptotic cell death in MCL1-positive DLBCL cell lines. In summary, MCL1 is deregulated in a significant fraction of ABC DLBCLs and contributes to therapy resistance. These data suggest that specific inhibition of MCL1 might be utilized therapeutically in a subset of DLBCLs.


Assuntos
Perfilação da Expressão Gênica , Linfoma Difuso de Grandes Células B/genética , Proteínas Proto-Oncogênicas c-bcl-2/genética , Antineoplásicos/uso terapêutico , Hibridização Genômica Comparativa , Humanos , Imuno-Histoquímica , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/patologia , Proteína de Sequência 1 de Leucemia de Células Mieloides , Reação em Cadeia da Polimerase em Tempo Real
20.
Clin Exp Allergy ; 42(10): 1459-71, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22994343

RESUMO

BACKGROUND: Airway inflammation in asthma involves innate immune responses. Toll-like receptors (TLRs) and thymic stromal lymphopoietin (TSLP) are thought to be involved in airway inflammation, but their expression in asthmatics' both large and small airways has not been investigated. OBJECTIVE: To analyse the expression of TLR2, TLR3, TLR4 and TSLP in large and small airways of asthmatics and compare their expression in smoking and non-smoking asthmatics; to investigate whether TLR expression is associated with eosinophilic or neutrophilic airway inflammation and with Mycoplasma pneumoniae and Chlamydophila pneumoniae infection. METHODS: Using immunohistochemistry and image analysis, we investigated TLR2, TLR3, TLR4 and TSLP expression in large and small airways of 24 victims of fatal asthma, FA, (13 non-smokers, 11 smokers) and nine deceased control subjects (DCtrl). TLRs were also measured in 18 mild asthmatics (MA) and 12 healthy controls (HCtrl). M. pneumoniae and C. pneumoniae in autopsy lung tissue were analysed using real-time polymerase chain reaction. Airway eosinophils and neutrophils were measured in all subjects. RESULTS: Fatal asthma patients had higher TLR2 in the epithelial and outer layers of large and small airways compared with DCtrls. Smoking asthmatics had lower TLR2 levels in the inner and outer layers of the small airways than non-smoking asthmatics. TSLP was increased in the epithelial and outer layers of the large airways of FA. FA patients had greater TLR3 expression in the outer layer of large airways and greater TLR4 expression in the outer layer of small airways. Eosinophilic airway inflammation was associated with TLR expression in the epithelium of FA. No bacterial DNA was detected in FA or DCtrls. MA and HCtrls had only a small difference in TLR3 expression. CONCLUSIONS AND CLINICAL RELEVANCE: Increased expression of TLR 2, 3 and 4 and TSLP in fatal asthma may contribute to the acute inflammation surrounding asthma deaths.


Assuntos
Asma/mortalidade , Citocinas/metabolismo , Receptor 2 Toll-Like/metabolismo , Receptor 3 Toll-Like/metabolismo , Receptor 4 Toll-Like/metabolismo , Adulto , Asma/imunologia , Feminino , Humanos , Inflamação/imunologia , Pulmão/imunologia , Masculino , Pessoa de Meia-Idade , Regulação para Cima , Linfopoietina do Estroma do Timo
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