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1.
Proc Natl Acad Sci U S A ; 120(39): e2305092120, 2023 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-37722046

RESUMO

Histone modifications are critical for regulating chromatin structure and gene expression. Dysregulation of histone modifications likely contributes to disease states and cancer. Depletion of the chromatin-binding protein BRWD3 (Bromodomain and WD repeat-containing protein 3), a known substrate-specificity factor of the Cul4-DDB1 E3 ubiquitin ligase complex, results in increased H3K4me1 (H3 lysine 4 monomethylation) levels. The underlying mechanism linking BRWD3 and H3K4 methylation, however, has yet to be defined. Here, we show that depleting BRWD3 not only causes an increase in H3K4me1 levels but also causes a decrease in H3K4me3 (H3 lysine 4 trimethylation) levels, indicating that BRWD3 influences H3K4 methylation more broadly. Using immunoprecipitation coupled to quantitative mass spectrometry, we identified an interaction between BRWD3 and the H3K4-specific lysine demethylase 5 (KDM5/Lid), an enzyme that removes tri- and dimethyl marks from H3K4. Moreover, analysis of ChIP-seq (chromatin immunoprecipitation sequencing) data revealed that BRWD3 and KDM5 are significantly colocalized throughout the genome and H3K4me3 are highly enriched at BRWD3 binding sites. We show that BRWD3 promotes K48-linked polyubiquitination and degradation of KDM5 and that KDM5 degradation is dependent on both BRWD3 and Cul4. Critically, depleting KDM5 fully restores altered H3K4me3 levels and partially restores H3K4me1 levels upon BRWD3 depletion. Together, our results demonstrate that BRWD3 regulates KDM5 activity to balance H3K4 methylation levels.


Assuntos
Lisina , Processamento de Proteína Pós-Traducional , Cromatina , Código das Histonas , Metilação , Drosophila , Animais
2.
Artigo em Inglês | MEDLINE | ID: mdl-37292252

RESUMO

Introduction: Malrotation of the intestinal tract is a congenital malformation commonly found either incidentally or after affected individuals develop signs and symptoms of intestinal obstruction. Malrotation is prone to midgut volvulus that can cause intestinal obstruction and lead to ischemia and necrosis requiring emergent surgical intervention. Rare instances of in utero midgut volvulus have been reported in the literature and carry a high mortality given the difficulty in establishing a diagnosis prior to development of signs of intestinal ischemia and necrosis. Advancements in imaging have made it possible to diagnose in utero malrotation earlier, raising the question of optimal timing of delivery, especially in cases of prenatally diagnosed midgut volvulus. In these cases, the risks of premature birth must be weighed against the risks of fetal intestinal ischemia and potential fetal demise. Case presentation: This case report details an interesting presentation of intestinal malrotation with suspected midgut volvulus found on prenatal imaging at 33 weeks and 4 days' gestation. This prompted delivery of the infant at 34 weeks and 2 days' gestation with urgent operative management, within 3 hours of life, after diagnosis was confirmed postnatally. Intraoperatively, the infant was confirmed to have midgut volvulus without bowel ischemia, the intestines were reduced, and a Ladd procedure was performed without incident. The infant recovered postoperatively without complication, tolerated advancement to full volume feeds and was discharged on day of life 18. Conclusion: Successful management of fetal malrotation with midgut volvulus may be accomplished by early access to a multi-disciplinary team of professionals, prompt postnatal confirmation of diagnosis, and urgent correction to minimize the risk of complications.

3.
bioRxiv ; 2023 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-37034668

RESUMO

Histone modifications are critical for regulating chromatin structure and gene expression. Dysregulation of histone modifications likely contributes to disease states and cancer. Depletion of the chromatin-binding protein BRWD3, a known substrate-specificity factor of the Cul4-DDB1 E3 ubiquitin ligase complex, results in increased in H3K4me1 levels. The underlying mechanism linking BRWD3 and H3K4 methylation, however, has yet to be defined. Here, we show that depleting BRWD3 not only causes an increase in H3K4me1 levels, but also causes a decrease in H3K4me3 levels, indicating that BRWD3 influences H3K4 methylation more broadly. Using immunoprecipitation coupled to quantitative mass spectrometry, we identified an interaction between BRWD3 and the H3K4-specific demethylase 5 (KDM5/Lid), an enzyme that removes tri- and di- methyl marks from H3K4. Moreover, analysis of ChIP-seq data revealed that BRWD3 and KDM5 are significantly co- localized throughout the genome and that sites of H3K4me3 are highly enriched at BRWD3 binding sites. We show that BRWD3 promotes K48-linked polyubiquitination and degradation of KDM5 and that KDM5 degradation is dependent on both BRWD3 and Cul4. Critically, depleting KDM5 fully restores altered H3K4me3 levels and partially restores H3K4me1 levels upon BRWD3 depletion. Together, our results demonstrate that BRWD3 regulates KDM5 activity to balance H3K4 methylation levels.

4.
Fetal Diagn Ther ; 50(2): 128-135, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37040717

RESUMO

INTRODUCTION: The aim of the study was to characterize the changes in fetal lung volume following fetoscopic endoluminal tracheal occlusion (FETO) that are associated with infant survival and need for extracorporeal membrane oxygenation (ECMO) in congenital diaphragmatic hernia (CDH). METHODS: Fetuses with CDH who underwent FETO at a single institution were included. CDH cases were reclassified by MRI metrics [observed-to-expected total lung volume (O/E TLV) and percent liver herniation]. The percent changes of MRI metrics after FETO were calculated. ROC-derived cutoffs of these changes were derived to predict infant survival to discharge. Regression analyses were done to determine the association between these cutoffs with infant survival and ECMO need, adjusted for site of CDH, gestational age at delivery, fetal sex, and CDH severity. RESULTS: Thirty CDH cases were included. ROC analysis demonstrated that post-FETO increases in O/E TLV had an area under the curve of 0.74 (p = 0.035) for the prediction of survival to hospital discharge; a cutoff of less than 10% was selected. Fetuses with a <10% post-FETO increase in O/E TLV had lower survival to hospital discharge [44.8% vs. 91.7%; p = 0.018] and higher ECMO use [61.1% vs. 16.7%; p = 0.026] compared to those with an O/E TLV increase ≥10%. Similar results were observed when the analyses were restricted to left-sided CDH cases. A post-FETO <10% increase in O/E TLV was independently associated with lower survival at hospital discharge (aOR: 0.073, 95% CI: 0.008-0.689; p = 0.022) and at 12 months of age (aOR: 0.091, 95% CI: 0.01-0.825; p = 0.036) as well as with higher ECMO use (aOR: 7.88, 95% CI: 1.31-47.04; p = 0.024). CONCLUSION: Fetuses with less than 10% increase in O/E TLV following the FETO procedure are at increased risk for requiring ECMO and for death in the postnatal period when adjusted for gestational age at delivery, CDH severity, and other confounders.


Assuntos
Obstrução das Vias Respiratórias , Hérnias Diafragmáticas Congênitas , Gravidez , Lactente , Feminino , Humanos , Hérnias Diafragmáticas Congênitas/diagnóstico por imagem , Hérnias Diafragmáticas Congênitas/cirurgia , Hérnias Diafragmáticas Congênitas/complicações , Fetoscopia/métodos , Pulmão , Medidas de Volume Pulmonar/métodos , Cuidado Pré-Natal , Obstrução das Vias Respiratórias/complicações , Traqueia/diagnóstico por imagem , Traqueia/cirurgia , Ultrassonografia Pré-Natal
5.
Eur J Obstet Gynecol Reprod Biol ; 281: 92-98, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36586211

RESUMO

OBJECTIVE: In fetuses with severe congenital diaphragmatic hernia, fetal endoluminal tracheal occlusion (FETO) with balloon increases survival and reduces morbidity. Balloon removal is often scheduled electively. In urgent cases, in-utero removal is impossible and removal immediately after delivery has to occur, posing risk of death from airway obstruction. Medical staff need training in urgent removal. Ideal training method is unclear; thus, we compared the performance of two groups trained by different methods. METHODS: 24 medical students were randomly assigned to two different learning methods for removal: Group 1 (in-person lecture) and Group 2 (online video). Both methods presented the same information: endoscopic instrument set-up, anatomical landmarks for intubation, and balloon removal. All participants were evaluated using the same instruments and high-fidelity simulator, comparing time for instrument set-up and simulate balloon removal (including removal attempts). RESULTS: Group 1 took significantly less time for instrument set-up compared to Group 2 [62 (30-92) secs vs 81 (57-108) secs; p < 0.01)]; no difference in time to intubate and locate the balloon [75 (50-173) secs vs 92 (32-232) secs; p 0.42], or number of attempts. CONCLUSION: There was no difference between video training and in-person training with regards to the time taken to locate the FETO balloon in the trachea and to simulate its removal.


Assuntos
Oclusão com Balão , Hérnias Diafragmáticas Congênitas , Treinamento por Simulação , Feminino , Humanos , Gravidez , Oclusão com Balão/métodos , Fetoscopia/métodos , Feto , Hérnias Diafragmáticas Congênitas/cirurgia , Traqueia/cirurgia
6.
ChemMedChem ; 18(1): e202200310, 2023 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-36128847

RESUMO

8-oxo Guanine DNA Glycosylase 1 is the initiating enzyme within base excision repair and removes oxidized guanines from damaged DNA. Since unrepaired 8-oxoG could lead to G : C→T : A transversion, base removal is of utmost importance for cells to ensure genomic integrity. For cells with elevated levels of reactive oxygen species this dependency is further increased. In the past we and others have validated OGG1 as a target for inhibitors to treat cancer and inflammation. Here, we present the optimization campaign that led to the broadly used tool compound TH5487. Based on results from a small molecule screening campaign, we performed hit to lead expansion and arrived at potent and selective substituted N-piperidinyl-benzimidazolones. Using X-ray crystallography data, we describe the surprising binding mode of the most potent member of the class, TH8535. Here, the N-Piperidinyl-linker adopts a chair instead of a boat conformation which was found for weaker analogues. We further demonstrate cellular target engagement and efficacy of TH8535 against a number of cancer cell lines.


Assuntos
DNA Glicosilases , Neoplasias , Humanos , DNA Glicosilases/química , DNA Glicosilases/genética , DNA Glicosilases/metabolismo , Guanina/química , Guanina/metabolismo , Reparo do DNA , Benzimidazóis/farmacologia , Dano ao DNA
7.
Front Mol Biosci ; 8: 636678, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33778007

RESUMO

Background: Acute respiratory distress syndrome (ARDS) is a clinical presentation of acute lung injury (ALI) with often fatal lung complication. Adenosine, a nucleoside generated following cellular stress provides protective effects in acute injury. The levels of extracellular adenosine can be depleted by equilibrative nucleoside transporters (ENTs). ENT inhibition by pharmaceutical agent dipyridamole promotes extracellular adenosine accumulation and is protective in ARDS. However, the therapeutic potential of dipyridamole in acute lung injury has not yet been evaluated. Methods: Adenosine acts on three adenosine receptors, the adenosine A1 (Adora1), A2a (Adora2a), the A2b (Adora2b) or the adenosine A3 (Adora 3) receptor. Accumulation of adenosine is usually required to stimulate the low-affinity Adora2b receptor. In order to investigate the effect of adenosine accumulation and the contribution of epithelial-specific ENT2 or adora2b expression in experimental ALI, dipyridamole, and epithelial specific ENT2 or Adora2b deficient mice were utilized. MLE12 cells were used to probe downstream Adora2b signaling. Adenosine receptors, transporters, and targets were determined in ARDS lungs. Results: ENT2 is mainly expressed in alveolar epithelial cells and is negatively regulated by hypoxia following tissue injury. Enhancing adenosine levels with ENT1/ENT2 inhibitor dipyridamole at a time when bleomycin-induced ALI was present, reduced further injury. Mice pretreated with the ADORA2B agonist BAY 60-6583 were protected from bleomycin-induced ALI by reducing vascular leakage (558.6 ± 50.4 vs. 379.9 ± 70.4, p < 0.05), total bronchoalveolar lavage fluid cell numbers (17.9 ± 1.8 to 13.4 ± 1.4 e4, p < 0.05), and neutrophil infiltration (6.42 ± 0.25 vs. 3.94 ± 0.29, p < 0.05). While mice lacking Adora2b in AECs were no longer protected by dipyridamole. We also identified occludin and focal adhesion kinase as downstream targets of ADORA2B, thus providing a novel mechanism for adenosine-mediated barrier protection. Similarly, we also observed similar enhanced ADORA2B (3.33 ± 0.67 to 16.12 ± 5.89, p < 0.05) and decreased occludin (81.2 ± 0.3 to 13.3 ± 0.4, p < 0.05) levels in human Acute respiratory distress syndrome lungs. Conclusion: We have highlighted a role of dipyridamole and adenosine signaling in preventing or treating ALI and identified Ent2 and Adora2b as key mediators in important for the resolution of ALI.

8.
J Biol Chem ; 296: 100568, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33753169

RESUMO

The enzyme NUDT15 efficiently hydrolyzes the active metabolites of thiopurine drugs, which are routinely used for treating cancer and inflammatory diseases. Loss-of-function variants in NUDT15 are strongly associated with thiopurine intolerance, such as leukopenia, and preemptive NUDT15 genotyping has been clinically implemented to personalize thiopurine dosing. However, understanding the molecular consequences of these variants has been difficult, as no structural information was available for NUDT15 proteins encoded by clinically actionable pharmacogenetic variants because of their inherent instability. Recently, the small molecule NUDT15 inhibitor TH1760 has been shown to sensitize cells to thiopurines, through enhanced accumulation of 6-thio-guanine in DNA. Building upon this, we herein report the development of the potent and specific NUDT15 inhibitor, TH7755. TH7755 demonstrates a greatly improved cellular target engagement and 6-thioguanine potentiation compared with TH1760, while showing no cytotoxicity on its own. This potent inhibitor also stabilized NUDT15, enabling analysis by X-ray crystallography. We have determined high-resolution structures of the clinically relevant NUDT15 variants Arg139Cys, Arg139His, Val18Ile, and V18_V19insGlyVal. These structures provide clear insights into the structural basis for the thiopurine intolerance phenotype observed in patients carrying these pharmacogenetic variants. These findings will aid in predicting the effects of new NUDT15 sequence variations yet to be discovered in the clinic.


Assuntos
Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Mutação , Pirofosfatases/antagonistas & inibidores , Pirofosfatases/genética , Tioguanina/química , Tioguanina/farmacologia , Cristalografia por Raios X , Modelos Moleculares , Conformação Proteica , Pirofosfatases/química
9.
ANZ J Surg ; 91(4): 668-672, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33605034

RESUMO

BACKGROUND: The incidence of vasovagal syncope (VVS) precipitated by medical procedures such as blood donation is quoted as between 0.13% and 4.17%. Vasovagal events have been observed to occur following cast removal at our paediatric orthopaedic clinic; however, there is no available information in the existing literature regarding incidence or risk factors. This study aims to identify the incidence and demographic traits of patients experiencing syncopal events following cast removal. METHODS: Over a 12-month period, paediatric patients experiencing a syncopal or pre-syncopal event during an outpatient appointment for cast removal were prospectively enrolled into the study. Basic demographic data were recorded, as well as injury and procedure details and a description of the event. Statistical analysis as well as calculation of incidence of vasovagal events were performed. RESULTS: A total of 6078 patients presented for cast removal in the 12-month period. Twenty syncopal or pre-syncopal events were recorded. Incidence was calculated as 0.32%. Mean patient age was 10.8 years. Male : female ratio was 2.3:1. Mean body mass index (BMI) was 20.08, with a trend for higher prevalence of males under the 50th BMI percentile-for-age. The mean time post-injury was 31.4 days. Ninety-five percent of patients were being treated for an upper limb injury and 30% had injuries that had been treated surgically. There were no associated secondary complications or injuries. CONCLUSIONS: Incidence of VVS following cast removal is comparable to the values quoted in literature for other medical procedures. Demographic data of our cohort suggested that those who experienced VVS were predominantly young males of lower-than-average BMI.


Assuntos
Ortopedia , Síncope Vasovagal , Instituições de Assistência Ambulatorial , Criança , Feminino , Humanos , Masculino , Estudos Prospectivos , Síncope/epidemiologia , Síncope/etiologia , Síncope Vasovagal/epidemiologia , Síncope Vasovagal/etiologia
10.
Proc Natl Acad Sci U S A ; 118(3)2021 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-33441483

RESUMO

Flaviviruses, including dengue and Zika, are widespread human pathogens; however, no broadly active therapeutics exist to fight infection. Recently, remodeling of endoplasmic reticulum (ER) proteostasis by pharmacologic regulators, such as compound 147, was shown to correct pathologic ER imbalances associated with protein misfolding diseases. Here, we establish an additional activity of compound 147 as an effective host-centered antiviral agent against flaviviruses. Compound 147 reduces infection by attenuating the infectivity of secreted virions without causing toxicity in host cells. Compound 147 is a preferential activator of the ATF6 pathway of the ER unfolded protein response, which requires targeting of cysteine residues primarily on protein disulfide isomerases (PDIs). We find that the antiviral activity of 147 is independent of ATF6 induction but does require modification of reactive thiols on protein targets. Targeting PDIs and additional non-PDI targets using RNAi and other small-molecule inhibitors was unable to recapitulate the antiviral effects, suggesting a unique polypharmacology may mediate the activity. Importantly, 147 can impair infection of multiple strains of dengue and Zika virus, indicating that it is suitable as a broad-spectrum antiviral agent.


Assuntos
Antivirais/farmacologia , Dengue/tratamento farmacológico , Bibliotecas de Moléculas Pequenas/farmacologia , Infecção por Zika virus/tratamento farmacológico , Dengue/virologia , Vírus da Dengue/efeitos dos fármacos , Vírus da Dengue/patogenicidade , Retículo Endoplasmático/efeitos dos fármacos , Humanos , Proteostase/efeitos dos fármacos , Resposta a Proteínas não Dobradas/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos , Zika virus/efeitos dos fármacos , Zika virus/patogenicidade , Infecção por Zika virus/virologia
11.
Hand (N Y) ; 16(2): 213-222, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-31137982

RESUMO

Background: Chronic recurrent multifocal osteomyelitis (CRMO) is a rare autoinflammatory condition characterized by bone pain and swelling, secondary to sterile bone osteolytic lesions. Estimated incidence is 1:1 000 000, with ~2% involving the hand. We present a case series of CRMO of the hand and review the available literature, with the aim of educating and raising awareness of this condition. Methods: A retrospective chart review was conducted for all patients presenting to the institution diagnosed with CRMO involving the hands. Subsequently, a literature review was performed. Results/Case Series: Three cases of CRMO of the hand were identified. Age ranged from 20 months to 6 years, with 1 female. Time from presentation to diagnosis ranged from 3 to 15 months. Two had a single lesion, with the remaining patient having a second lesion on full-body magnetic resonance imaging (MRI). Three lesions involved phalanges, and one involved a metacarpal. Two received antibiotics without improvement prior to diagnosis. After diagnosis of CRMO, two received intravenous pamidronate. They both later showed improvement on MRI. Conclusion: CRMO is a rare disease with scarce literature to guide management. We present a series of CRMO specifically of the hand. The cases educate key stakeholders, raise awareness of the diagnosis, and illustrate challenging aspects of managing these patients. This includes the special functional and anatomical consideration essential in managing cases involving the hand.


Assuntos
Osteomielite , Doenças Raras , Criança , Pré-Escolar , Feminino , Mãos/patologia , Humanos , Lactente , Imageamento por Ressonância Magnética , Masculino , Osteomielite/diagnóstico por imagem , Osteomielite/tratamento farmacológico , Estudos Retrospectivos
12.
Dentomaxillofac Radiol ; 49(7): 20200072, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32464075

RESUMO

OBJECTIVES: To identify a dose as low as diagnostically acceptable and a threshold level of image quality for cone beam CT (CBCT) imaging root canals, using maxillary first molar (M1M) second mesiobuccal (MB2) canals of varying complexity for two CBCT scanners. METHODS: Dose-area product (DAP) and contrast-to-noise ratio (CNR) were measured for two scanners at a range of exposure parameters. Subjective-image-quality assessment at the same exposures was performed for three M1Ms of varying MB2 complexity, positioned in an anthropomorphic phantom. Nine raters (three endodontists, three dental radiologists and three junior staff) assessed canal visibility, using a 5-point confidence scale rating. RESULTS: Identification of simple-moderate MB2 canal complexity was achieved at a range of protocols, with DAP values of ≥209.3 and ≥203.2 mGy cm² and CNRs of 3 and 7.6 for Promax®3D and Accuitomo-F170® respectively. For complex canal anatomy, target subjective image quality was not achieved, even at the highest DAP values for both scanners. Junior staff classified significantly more images as undiagnostic compared with senior staff (p = 0.043). CONCLUSIONS: In this first study to address optimisation of CBCT imaging of root canal anatomy, a similar threshold dose for both scanners was identified for M1Ms with simple-moderate MB2 canal complexity. Increasing dose to enhance visualisation of more complex canal anatomy was ineffective. Selection of standard protocols (while avoiding lower kV/mA protocols) instead of high-resolution scans was a practical means of reducing patient dose. CNR is not a transferable measure of image quality.


Assuntos
Cavidade Pulpar , Maxila , Tomografia Computadorizada de Feixe Cônico , Humanos , Dente Molar , Tratamento do Canal Radicular
13.
Br Dent J ; 228(8): 587-594, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32332956

RESUMO

The maxillary sinus is the largest of the paranasal sinuses, with its structure and contents commonly visualised on dental radiographs. Dental practitioners are required to evaluate the entire radiograph, and it is likely there is limited exposure to maxillary sinus pathoses and radiological interpretation in the undergraduate curriculum and routine continuing professional development courses. This review covers radiological features of common benign and malignant sinus disease. Identification of normal anatomical features, common variations and pathoses can facilitate holistic patient management and potentially early detection of neoplastic disease.


Assuntos
Seio Maxilar , Doenças dos Seios Paranasais , Odontólogos , Humanos , Seio Maxilar/diagnóstico por imagem , Doenças dos Seios Paranasais/diagnóstico por imagem , Papel Profissional , Radiografia
14.
J Clin Invest ; 129(5): 1984-1999, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30830875

RESUMO

Idiopathic pulmonary fibrosis (IPF) is a chronic and deadly disease with a poor prognosis and few treatment options. Pathological remodeling of the extracellular matrix (ECM) by myofibroblasts is a key factor that drives disease pathogenesis, although the underlying mechanisms remain unknown. Alternative polyadenylation (APA) has recently been shown to play a major role in cellular responses to stress by driving the expression of fibrotic factors and ECMs through altering microRNA sensitivity, but a connection to IPF has not been established. Here, we demonstrate that CFIm25, a global regulator of APA, is down-regulated in the lungs of patients with IPF and mice with pulmonary fibrosis, with its expression selectively reduced in alpha-smooth muscle actin (α-SMA) positive fibroblasts. Following the knockdown of CFIm25 in normal human lung fibroblasts, we identified 808 genes with shortened 3'UTRs, including those involved in the transforming growth factor-ß signaling pathway, the Wnt signaling pathway, and cancer pathways. The expression of key pro-fibrotic factors can be suppressed by CFIm25 overexpression in IPF fibroblasts. Finally, we demonstrate that deletion of CFIm25 in fibroblasts or myofibroblast precursors using either the Col1a1 or the Foxd1 promoter enhances pulmonary fibrosis after bleomycin exposure in mice. Taken together, our results identified CFIm25 down-regulation as a novel mechanism to elevate pro-fibrotic gene expression in pulmonary fibrosis.


Assuntos
Fator de Especificidade de Clivagem e Poliadenilação/metabolismo , Poliadenilação , Fibrose Pulmonar/metabolismo , Fibrose Pulmonar/fisiopatologia , Regiões 3' não Traduzidas , Actinas/metabolismo , Adulto , Idoso , Animais , Bleomicina/farmacologia , Progressão da Doença , Regulação para Baixo , Matriz Extracelular/metabolismo , Feminino , Fibroblastos/metabolismo , Humanos , Pulmão/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/metabolismo , Pessoa de Meia-Idade , Músculo Liso/metabolismo , Miofibroblastos/metabolismo , RNA Interferente Pequeno/metabolismo , Transdução de Sinais , Fator de Crescimento Transformador beta/metabolismo
15.
Angew Chem Int Ed Engl ; 58(8): 2305-2309, 2019 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-30664319

RESUMO

Spirotetronate and spirotetramate natural products include a multitude of compounds with potent antimicrobial and antitumor activities. Their biosynthesis incorporates many unusual biocatalytic steps, including regio- and stereo-specific modifications, cyclizations promoted by Diels-Alderases, and acetylation-elimination reactions. Here we focus on the acetate elimination catalyzed by AbyA5, implicated in the formation of the key Diels-Alder substrate to give the spirocyclic system of the antibiotic abyssomicin C. Using synthetic substrate analogues, it is shown that AbyA5 catalyzes stereospecific acetate elimination, establishing the (R)-tetronate acetate as a biosynthetic intermediate. The X-ray crystal structure of AbyA5, the first of an acetate-eliminating enzyme, reveals a deviant acetyl esterase fold. Molecular dynamics simulations and enzyme assays show the use of a His-Ser dyad to catalyze either elimination or hydrolysis, via disparate mechanisms, under substrate control.


Assuntos
Acetatos/metabolismo , Liases/metabolismo , Compostos de Espiro/metabolismo , Acetatos/química , Biocatálise , Cristalografia por Raios X , Modelos Moleculares , Estrutura Molecular , Compostos de Espiro/química
16.
Front Physiol ; 9: 555, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29910735

RESUMO

Background: Pulmonary hypertension (PH) is a devastating and progressive disease characterized by excessive proliferation of pulmonary artery smooth muscle cells (PASMCs) and remodeling of the lung vasculature. Adenosine signaling through the ADORA2B receptor has previously been implicated in disease progression and tissue remodeling in chronic lung disease. In experimental models of PH associated with chronic lung injury, pharmacological or genetic inhibition of ADORA2B improved markers of chronic lung injury and hallmarks of PH. However, the contribution of ADORA2B expression in the PASMC was not fully evaluated. Hypothesis: We hypothesized that adenosine signaling through the ADORA2B receptor in PASMC mediates the development of PH. Methods: PASMCs from controls and patients with idiopathic pulmonary arterial hypertension (iPAH) were characterized for expression levels of all adenosine receptors. Next, we evaluated the development of PH in ADORA2Bf/f-Transgelin (Tagln)cre mice. These mice or adequate controls were exposed to a combination of SUGEN (SU5416, 20 mg/kg/b.w. IP) and hypoxia (10% O2) for 28 days (HX-SU) or to chronic low doses of bleomycin (BLM, 0.035U/kg/b.w. IP). Cardiovascular readouts including right ventricle systolic pressures (RVSPs), Fulton indices and vascular remodeling were determined. Using PASMCs we identified ADORA2B-dependent mediators involved in vascular remodeling. These mediators: IL-6, hyaluronan synthase 2 (HAS2) and tissue transglutaminase (Tgm2) were determined by RT-PCR and validated in our HX-SU and BLM models. Results: Increased levels of ADORA2B were observed in PASMC from iPAH patients. ADORA2Bf/f-Taglncre mice were protected from the development of PH following HX-SU or BLM exposure. In the BLM model of PH, ADORA2Bf/f- Taglncre mice were not protected from the development of fibrosis. Increased expression of IL-6, HAS2 and Tgm2 was observed in PASMC in an ADORA2B-dependent manner. These mediators were also reduced in ADORA2Bf/f- Taglncre mice exposed to HX-SU or BLM. Conclusions: Our studies revealed ADORA2B-dependent increased levels of IL-6, hyaluronan and Tgm2 in PASMC, consistent with reduced levels in ADORA2Bf/f- Taglncre mice exposed to HX-SU or BLM. Taken together, our data indicates that ADORA2B on PASMC mediates the development of PH through the induction of IL-6, hyaluronan and Tgm2. These studies point at ADORA2B as a therapeutic target to treat PH.

17.
Soc Psychiatry Psychiatr Epidemiol ; 53(5): 497-507, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29556667

RESUMO

PURPOSE: To investigate whether psychotic experiences and depressive symptoms at ages 12 and 18 years are associated with adverse life outcomes across a range of functional domains between 16 and 20 years of age. METHODS: Data were gathered from ALSPAC, a UK birth cohort. Individuals were assessed with the semi-structured Psychosis-Like Symptoms Interview and the Short Mood and Feeling Questionnaire at ages 12 and 18 years. Logistic regression was used to explore associations with outcomes in education, occupation, social functioning, substance use (alcohol, cannabis, smoking, and other drugs), and illegal behaviour between the ages of 16 and 20 years. All associations were adjusted for socio-demographic and childhood confounders and for comorbid psychotic experiences or depressive symptoms. RESULTS: Psychotic experiences and depression at age 12 were associated with poorer educational, occupational, and social outcomes between the ages of 16 and 20; these withstood adjustment for confounding. Depressive symptoms at age 12 were also associated with harmful drinking. Psychotic experiences and depression at age 18 were additionally associated with other forms of substance use and illegal behaviour. Comorbidity had little impact at age 12, but was associated with significantly worse educational, social, and substance use outcomes at age 18. CONCLUSIONS: Adolescent psychotic experiences and depression represent a risk marker for a number of later adverse outcomes, most consistently with education and employment, but also social impairment, harmful drinking, and substance use. This highlights the importance of recognizing adolescent psychopathology, so that support can be provided to try and minimize adverse outcomes.


Assuntos
Comportamento do Adolescente/psicologia , Depressão/psicologia , Transtornos Psicóticos/psicologia , Adolescente , Criança , Estudos de Coortes , Comorbidade , Crime/psicologia , Escolaridade , Emprego/psicologia , Feminino , Humanos , Modelos Logísticos , Masculino , Transtornos Relacionados ao Uso de Substâncias/psicologia , Inquéritos e Questionários , Adulto Jovem
18.
Pediatr Res ; 2017 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-28832580

RESUMO

BackgroundHyperoxic lung injury is characterized by cellular damage from high oxygen concentrations that lead to an inflammatory response and it disrupts normal alveolarization in the developing newborn lung. Adenosine is a signaling molecule that is generated extracellularly by ecto-5'-nucleotidase (CD73) in response to injury. Extracellular adenosine signals through cell surface receptors and has been found to have a protective role in acute injury situations; however, chronic elevations have been associated with detrimental changes in chronic lung diseases. We hypothesized that hyperoxia-induced lung injury leads to CD73-mediated increases in extracellular adenosine, which are detrimental to the newborn lung.MethodsC57Bl/6 and CD73-/- mice were exposed to 95% oxygen, 70% oxygen, or room air. Adenosine concentration and markers of pulmonary inflammation and lung development were measured.ResultsExposure to hyperoxia caused pulmonary inflammation and disrupted normal alveolar development in association with increased pulmonary adenosine levels. Loss of CD73-mediated extracellular adenosine production led to decreased survival with exposure to 95% oxygen, and exacerbated pulmonary inflammation and worsened lung development with 70% oxygen exposure.ConclusionExposure to hyperoxia causes lung injury associated with an increase in adenosine concentration, and loss of CD73-mediated adenosine production leads to worsening of hyperoxic lung injury.Pediatric Research advance online publication, 23 August 2017; doi:10.1038/pr.2017.176.

19.
FASEB J ; 31(11): 4745-4758, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28701304

RESUMO

Idiopathic pulmonary fibrosis (IPF) is a deadly chronic lung disease. Extracellular accumulation of adenosine and subsequent activation of the ADORA2B receptor play important roles in regulating inflammation and fibrosis in IPF. Additionally, alternatively activated macrophages (AAMs) expressing ADORA2B have been implicated in mediating adenosine's effects in IPF. Although hypoxic conditions are present in IPF, hypoxia's role as a direct modulator of macrophage phenotype and identification of factors that regulate ADORA2B expression on AAMs in IPF is not well understood. In this study, an experimental mouse model of pulmonary fibrosis and lung samples from patients with IPF were used to examine the effects and interactions of macrophage differentiation and hypoxia on fibrosis. We demonstrate that hypoxia-inducible factor 1-α (HIF1A) inhibition in late stages of bleomycin-induced injury attenuates pulmonary fibrosis in association, with reductions in ADORA2B expression in AAMs. Additionally, ADORA2B deletion or pharmacological antagonism along with HIF1A inhibition disrupts AAM differentiation and subsequent IL-6 production in cultured macrophages. These findings suggest that hypoxia, through HIF1A, contributes to the development and progression of pulmonary fibrosis through its regulation of ADORA2B expression on AAMs, cell differentiation, and production of profibrotic mediators. These studies support a potential role for HIF1A or ADORA2B antagonists in the treatment of IPF.-Philip, K., Mills, T. W., Davies, J., Chen, N.-Y., Karmouty-Quintana, H., Luo, F., Molina, J. G., Amione-Guerra, J., Sinha, N., Guha, A., Eltzschig, H. K., Blackburn, M. R. HIF1A up-regulates the ADORA2B receptor on alternatively activated macrophages and contributes to pulmonary fibrosis.


Assuntos
Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Macrófagos Alveolares , Macrófagos/metabolismo , Fibrose Pulmonar/metabolismo , Receptor A2B de Adenosina/biossíntese , Regulação para Cima , Adulto , Idoso , Animais , Bleomicina/efeitos adversos , Bleomicina/farmacologia , Hipóxia Celular/efeitos dos fármacos , Hipóxia Celular/genética , Células Cultivadas , Feminino , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Interleucina-6/biossíntese , Interleucina-6/genética , Macrófagos/patologia , Masculino , Camundongos , Camundongos Transgênicos , Pessoa de Meia-Idade , Fibrose Pulmonar/induzido quimicamente , Fibrose Pulmonar/genética , Fibrose Pulmonar/patologia , Receptor A2B de Adenosina/genética
20.
Lipid Insights ; 9: 13-29, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27867302

RESUMO

Statins, a class of cholesterol-lowering medications that inhibit 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase, are commonly administered to treat atherosclerotic cardiovascular disease. Statin use may expand considerably given its potential for treating an array of cholesterol-independent diseases. However, the lack of conclusive evidence supporting these emerging therapeutic uses of statins brings to the fore a number of unanswered questions including uncertainties regarding patient-to-patient variability in response to statins, the most appropriate statin to be used for the desired effect, and the efficacy of statins in treating cholesterol-independent diseases. In this review, the adverse effects, costs, and drug-drug and drug-food interactions associated with statin use are presented. Furthermore, we discuss the pleiotropic effects associated with statins with regard to the onset and progression of autoimmune and inflammatory diseases, cancer, neurodegenerative disorders, strokes, bacterial infections, and human immunodeficiency virus. Understanding these issues will improve the prognosis of patients who are administered statins and potentially expand our ability to treat a wide variety of diseases.

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