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1.
Angew Chem Int Ed Engl ; 63(21): e202400781, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38527936

RESUMO

Short amphipathic peptides are capable of binding to transcriptional coactivators, often targeting the same binding surfaces as native transcriptional activation domains. However, they do so with modest affinity and generally poor selectivity, limiting their utility as synthetic modulators. Here we show that incorporation of a medium-chain, branched fatty acid to the N-terminus of one such heptameric lipopeptidomimetic (LPPM-8) increases the affinity for the coactivator Med25 >20-fold (Ki >100 µM to 4 µM), rendering it an effective inhibitor of Med25 protein-protein interactions (PPIs). The lipid structure, the peptide sequence, and the C-terminal functionalization of the lipopeptidomimetic each influence the structural propensity of LPPM-8 and its effectiveness as an inhibitor. LPPM-8 engages Med25 through interaction with the H2 face of its activator interaction domain and in doing so stabilizes full-length protein in the cellular proteome. Further, genes regulated by Med25-activator PPIs are inhibited in a cell model of triple-negative breast cancer. Thus, LPPM-8 is a useful tool for studying Med25 and mediator complex biology and the results indicate that lipopeptidomimetics may be a robust source of inhibitors for activator-coactivator complexes.


Assuntos
Complexo Mediador , Ativação Transcricional , Humanos , Complexo Mediador/metabolismo , Complexo Mediador/química , Peptídeos/química , Peptídeos/farmacologia , Peptídeos/metabolismo , Ligação Proteica , Ativação Transcricional/efeitos dos fármacos
2.
Synlett ; 34(13): 1554-1562, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37876737

RESUMO

This Account summarizes efforts in our group toward synthesis of heterocycles in the past decade. Selected examples of transannulative heterocyclizations, intermediate construction of reactive compounds en route to these important motifs, and newer developments of a radical approach are outlined.

3.
J Am Chem Soc ; 145(35): 19265-19273, 2023 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-37625118

RESUMO

We report the first one-pot formal alkene carboradiofluorination reaction employing easily accessible alkenes as both prosthetic group precursors and coupling partners. The methodology features rapid sequential Markovnikov-selective iodofluorination and photoinduced Pd(0/I/II)-catalyzed alkyl Heck reaction as a mild and robust fluorine-18 (18F) radiochemical approach for positron emission tomography (PET) imaging probe development. A new class of prosthetic groups for PET imaging probe synthesis was isolated as iodofluorinated intermediates in moderate to excellent yields. The one-pot formal alkenylfluorination reaction was carried out to produce over 30 analogues of a wide range of bioactive molecules. Further application of the Pd(0/I/II) manifold in PET probe development was illustrated by the direct carbo(radio)fluorination of electron-rich alkenes. The methods were successfully translated to radiolabel a broad scope of medicinally relevant small molecules in generally good radiochemical conversion. The protocol was further optimized to accommodate no-carrier-added conditions with similar efficiency for future (pre)clinical translation. Moreover, the radiosynthesis of prosthetic groups was automated in a radiochemistry module to facilitate its practical use in multistep radiochemical reactions.


Assuntos
Alcenos , Elétrons , Tomografia por Emissão de Pósitrons , Radioquímica , Compostos Radiofarmacêuticos
4.
Metabolites ; 13(4)2023 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-37110148

RESUMO

Environmental enteric dysfunction (EED) is characterized by intestinal inflammation, malabsorption and growth-faltering in children with heightened exposure to gut pathogens. The aim of this study was to characterize serum non-esterified fatty acids (NEFA), in association with childhood undernutrition and EED, as potential biomarkers to predict growth outcomes. The study comprised a cohort of undernourished rural Pakistani infants (n = 365) and age-matched controls followed prospectively up to 24 months of age. Serum NEFA were quantified at ages 3-6 and 9 months and correlated with growth outcomes, serum bile acids and EED histopathological biomarkers. Serum NEFA correlated with linear growth-faltering and systemic and gut biomarkers of EED. Undernourished children exhibited essential fatty acid deficiency (EFAD), with low levels of linoleic acid and total n-6 polyunsaturated fatty acids, compensated by increased levels of oleic acid and increased elongase and desaturase activities. EFAD correlated with reduced anthropometric Z scores at 3-6 and 9 months of age. Serum NEFA also correlated with elevated BA and liver dysfunction. Essential fatty acid depletion and altered NEFA metabolism were highly prevalent and associated with acute and chronic growth-faltering in EED. The finding suggests that targeting early interventions to correct EFAD and promote FA absorption in children with EED may facilitate childhood growth in high-risk settings.

5.
bioRxiv ; 2023 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-36993479

RESUMO

Short amphipathic peptides are capable of binding to transcriptional coactivators, often targeting the same binding surfaces as native transcriptional activation domains. However, they do so with modest affinity and generally poor selectivity, limiting their utility as synthetic modulators. Here we show that incorporation of a medium-chain, branched fatty acid to the N-terminus of one such heptameric lipopeptidomimetic (34913-8) increases the affinity for the coactivator Med25 >10-fold ( Ki >>100 µM to 10 µM). Importantly, the selectivity of 34913-8 for Med25 compared to other coactivators is excellent. 34913-8 engages Med25 through interaction with the H2 face of its Ac tivator I nteraction D omain and in doing so stabilizes full-length protein in the cellular proteome. Further, genes regulated by Med25-activator PPIs are inhibited in a cell model of triple-negative breast cancer. Thus, 34913-8 is a useful tool for studying Med25 and the Mediator complex biology and the results indicate that lipopeptidomimetics may be a robust source of inhibitors for activator-coactivator complexes.

7.
Gut Microbes ; 15(1): 2183690, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36843227

RESUMO

Cholestasis refers to impaired bile flow from the liver to the intestine. In neonates, cholestasis causes poor growth and may progress to liver failure and death. Normal bile flow requires an intact liver-gut-microbiome axis, whereby liver-derived primary bile acids are transformed into secondary bile acids. Microbial bile salt hydrolase (BSH) enzymes are responsible for the first step, deconjugating glycine- and taurine-conjugated primary bile acids. Cholestatic neonates often are treated with the potent choleretic bile acid ursodeoxycholic acid (UDCA), although interactions between UDCA, gut microbes, and other bile acids are poorly understood. To gain insight into how the liver-gut-microbiome axis develops in extreme prematurity and how cholestasis alters this maturation, we conducted a nested case-control study collecting 124 stool samples longitudinally from 24 preterm infants born at mean 27.2 ± 1.8 weeks gestation and 946 ± 249.6 g, half of whom developed physiologic cholestasis. Samples were analyzed by whole metagenomic sequencing, in vitro BSH enzyme activity assays optimized for low biomass fecal samples, and quantitative mass spectrometry to measure the bile acid metabolome. In extremely preterm neonates, acquisition of the secondary bile acid biosynthesis pathway and BSH genes carried by Clostridium perfringens are the most prominent features of early microbiome development. Cholestasis interrupts this developmental pattern. BSH gene abundance and enzyme activity are profoundly reduced in cholestatic neonates, resulting in decreased quantities of unconjugated bile acids. UDCA restores total fecal bile acid levels in cholestatic neonates, but this is due to a 522-fold increase in fecal UDCA. A majority of bile acids in early development are atypical positional and stereo-isomers of bile acids. We report novel associations linking isomeric bile acids and BSH activity to neonatal growth trajectories. These data highlight deconjugation of bile acids as a key microbial function that is acquired in early neonatal development and impaired by cholestasis.


Assuntos
Colestase , Microbioma Gastrointestinal , Humanos , Recém-Nascido , Estudos de Casos e Controles , Recém-Nascido Prematuro , Ácido Ursodesoxicólico , Ácidos e Sais Biliares
8.
Hepatology ; 77(3): 862-873, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36131538

RESUMO

BACKGROUND AND AIMS: In biliary atresia, serum bilirubin is commonly used to predict outcomes after Kasai portoenterostomy (KP). Infants with persistently high levels invariably need liver transplant, but those achieving normalized levels have a less certain disease course. We hypothesized that serum bile acid levels could help predict outcomes in the latter group. APPROACH AND RESULTS: Participants with biliary atresia from the Childhood Liver Disease Research Network were included if they had normalized bilirubin levels 6 months after KP and stored serum samples from the 6-month post-KP clinic visit ( n  = 137). Bile acids were measured from the stored serum samples and used to divide participants into ≤40 µmol/L ( n  = 43) or >40 µmol/L ( n  = 94) groups. At 2 years of age, the ≤40 µmol/L compared with >40 µmol/L group had significantly lower total bilirubin, aspartate aminotransferase, alanine aminotransferase, gamma-glutamyltransferase, bile acids, and spleen size, as well as significantly higher albumin and platelet counts. Furthermore, during 734 person-years of follow-up, those in the ≤40 µmol/L group were significantly less likely to develop splenomegaly, ascites, gastrointestinal bleeding, or clinically evident portal hypertension. The ≤40 µmol/L group had a 10-year cumulative incidence of liver transplant/death of 8.5% (95% CI: 1.1%-26.1%), compared with 42.9% (95% CI: 28.6%-56.4%) for the >40 µmol/L group ( p  = 0.001). CONCLUSIONS: Serum bile acid levels may be a useful prognostic biomarker for infants achieving normalized bilirubin levels after KP.


Assuntos
Atresia Biliar , Lactente , Humanos , Criança , Atresia Biliar/cirurgia , Portoenterostomia Hepática , Prognóstico , Bilirrubina , Ácidos e Sais Biliares , Biomarcadores , Resultado do Tratamento , Estudos Retrospectivos
9.
Gigascience ; 112022 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-35077540

RESUMO

BACKGROUND: Mitigating the effects of global warming has become the main challenge for humanity in recent decades. Livestock farming contributes to greenhouse gas emissions, with an important output of methane from enteric fermentation processes, mostly in ruminants. Because ruminal microbiota is directly involved in digestive fermentation processes and methane biosynthesis, understanding the ecological relationships between rumen microorganisms and their active metabolic pathways is essential for reducing emissions. This study analysed whole rumen metagenome using long reads and considering its compositional nature in order to disentangle the role of rumen microbes in methane emissions. RESULTS: The ß-diversity analyses suggested a subtle association between methane production and overall microbiota composition (0.01 < R2 < 0.02). Differential abundance analysis identified 36 genera and 279 KEGGs as significantly associated with methane production (Padj < 0.05). Those genera associated with high methane production were Eukaryota from Alveolata and Fungi clades, while Bacteria were associated with low methane emissions. The genus-level association network showed 2 clusters grouping Eukaryota and Bacteria, respectively. Regarding microbial gene functions, 41 KEGGs were found to be differentially abundant between low- and high-emission animals and were mainly involved in metabolic pathways. No KEGGs included in the methane metabolism pathway (ko00680) were detected as associated with high methane emissions. The KEGG network showed 3 clusters grouping KEGGs associated with high emissions, low emissions, and not differentially abundant in either. A deeper analysis of the differentially abundant KEGGs revealed that genes related with anaerobic respiration through nitrate degradation were more abundant in low-emission animals. CONCLUSIONS: Methane emissions are largely associated with the relative abundance of ciliates and fungi. The role of nitrate electron acceptors can be particularly important because this respiration mechanism directly competes with methanogenesis. Whole metagenome sequencing is necessary to jointly consider the relative abundance of Bacteria, Archaea, and Eukaryota in the statistical analyses. Nutritional and genetic strategies to reduce CH4 emissions should focus on reducing the relative abundance of Alveolata and Fungi in the rumen. This experiment has generated the largest ONT ruminal metagenomic dataset currently available.


Assuntos
Metano , Rúmen , Animais , Bovinos , Fungos , Metagenoma , Metagenômica , Metano/metabolismo , Rúmen/microbiologia
10.
Nat Rev Chem ; 6(8): 544-561, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37034136

RESUMO

Synthetic chemists have long focused on selective C(sp 3)-N bond-forming approaches in response to the high value of this motif in natural products, pharmaceutical agents and functional materials. In recent years, visible light-induced protocols have become an important synthetic platform to promote this transformation under mild reaction conditions. These photo-driven methods rely on converting visible light into chemical energy to generate reactive but controllable radical species. This Review highlights recent advances in this area, mostly after 2014, with an emphasis placed on C(sp 3)-H bond activations, including amination of olefins and carbonyl compounds, and cross-coupling reactions.

11.
Anim Microbiome ; 3(1): 63, 2021 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-34551823

RESUMO

BACKGROUND: Rumen microorganisms carry antimicrobial resistance genes which pose a threaten to animals and humans in a One Health context. In order to tackle the emergence of antimicrobial resistance it is vital to understand how they appear, their relationship with the host, how they behave as a whole in the ruminal ecosystem or how they spread to the environment or humans. We sequenced ruminal samples from 416 Holstein dairy cows in 14 Spanish farms using nanopore technology, to uncover the presence of resistance genes and their potential effect on human, animal and environmental health. RESULTS: We found 998 antimicrobial resistance genes (ARGs) in the cow rumen and studied the 25 most prevalent genes in the 14 dairy cattle farms. The most abundant ARGs were related to the use of antibiotics to treat mastitis, metritis and lameness, the most common diseases in dairy cattle. The relative abundance (RA) of bacteriophages was positively correlated to the ARGs RA. The heritability of the RA of the more abundant ARGs ranged between 0.10 (mupA) and 0.49 (tetW), similar to the heritability of the RA of microbes that carried those ARGs. Even though these genes are carried by the microorganisms, the host is partially controlling their RA by having a more suitable rumen pH, folds, or other physiological traits that promote the growth of those microorganisms. CONCLUSIONS: We were able to determine the most prevalent ARGs (macB, msbA, parY, rpoB2, tetQ and TaeA) in the ruminal bacteria ecosystem. The rumen is a reservoir of ARGs, and strategies to reduce the ARG load from livestock must be pursued.

12.
Appl Microbiol Biotechnol ; 105(8): 3225-3234, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33792750

RESUMO

Nanopore sequencing has emerged as a rapid and cost-efficient tool for diagnostic and epidemiological surveillance of SARS-CoV-2 during the COVID-19 pandemic. This study compared the results from sequencing the SARS-CoV-2 genome using R9 vs R10 flow cells and a Rapid Barcoding Kit (RBK) vs a Ligation Sequencing Kit (LSK). The R9 chemistry provided a lower error rate (3.5%) than R10 chemistry (7%). The SARS-CoV-2 genome includes few homopolymeric regions. Longest homopolymers were composed of 7 (TTTTTTT) and 6 (AAAAAA) nucleotides. The R10 chemistry resulted in a lower rate of deletions in thymine and adenine homopolymeric regions than the R9, at the expenses of a larger rate (~10%) of mismatches in these regions. The LSK had a larger yield than the RBK, and provided longer reads than the RBK. It also resulted in a larger percentage of aligned reads (99 vs 93%) and also in a complete consensus genome. The results from this study suggest that the LSK preparation library provided longer DNA fragments which contributed to a better assembly of the SARS-CoV-2, despite an impaired detection of variants in a R10 flow cell. Nanopore sequencing could be used in epidemiological surveillance of SARS-CoV-2. KEY POINTS: • Sequencing SARS-CoV-2 genome is of great importance for the pandemic surveillance. • Nanopore offers a low cost and accurate method to sequence SARS-CoV-2 genome. • Ligation sequencing is preferred rather than the rapid kit using transposases.


Assuntos
Genoma Viral , Nanoporos , SARS-CoV-2/genética , Análise de Sequência de RNA/métodos
13.
J Dairy Sci ; 104(7): 8135-8151, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33896632

RESUMO

The rumen is a complex microbial system of substantial importance in terms of greenhouse gas emissions and feed efficiency. This study proposes combining metagenomic and host genomic data for selective breeding of the cow hologenome toward reduced methane emissions. We analyzed nanopore long reads from the rumen metagenome of 437 Holstein cows from 14 commercial herds in 4 northern regions in Spain. After filtering, data were treated as compositional. The large complexity of the rumen microbiota was aggregated, through principal component analysis (PCA), into few principal components (PC) that were used as proxies of the core metagenome. The PCA allowed us to condense the huge and fuzzy taxonomical and functional information from the metagenome into a few PC. Bivariate animal models were applied using these PC and methane production as phenotypes. The variability condensed in these PC is controlled by the cow genome, with heritability estimates for the first PC of ~0.30 at all taxonomic levels, with a large probability (>83%) of the posterior distribution being >0.20 and with the 95% highest posterior density interval (95%HPD) not containing zero. Most genetic correlation estimates between PC1 and methane were large (≥0.70), with most of the posterior distribution (>82%) being >0.50 and with its 95%HPD not containing zero. Enteric methane production was positively associated with relative abundance of eukaryotes (protozoa and fungi) through the first component of the PCA at phylum, class, order, family, and genus. Nanopore long reads allowed the characterization of the core rumen metagenome using whole-metagenome sequencing, and the purposed aggregated variables could be used in animal breeding programs to reduce methane emissions in future generations.


Assuntos
Metano , Microbiota , Animais , Bovinos/genética , Feminino , Fermentação , Metano/metabolismo , Microbiota/genética , Rúmen/metabolismo , Seleção Artificial , Espanha
14.
J Heart Lung Transplant ; 40(3): 210-219, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33349521

RESUMO

BACKGROUND: Delayed gastric emptying has been associated with increased graft rejection, although the mechanism of this association is not known. This study aims to investigate the interrelationship between delays in gastrointestinal motility and the diversity and composition of gastric, oropharyngeal, and lung microbiomes in pediatric lung transplant recipients. METHODS: We prospectively recruited 23 pediatric lung transplant recipients and 98 pediatric patients with respiratory symptoms undergoing combined endoscopy and bronchoscopy. Gastric, oropharyngeal, and bronchoalveolar lavage samples were collected for 16S sequencing. Gastric samples were also analyzed for bile composition using liquid chromatography. RESULTS: Patients who underwent lung transplantation had significantly reduced alpha diversity in gastric and oropharyngeal sites compared with patients with respiratory symptoms. This reduction in alpha diversity was especially evident in gastric samples in patients with delayed gastric emptying defined as abnormal gastric emptying on nuclear scintigraphy or as an elevation in gastric bile concentration (p ≤ 0.05). Whereas monocolonies were seen in the lungs of patients who underwent transplantation, these were not the same microbes seen in the stomach; the microbial overlap between lung and gastric samples within patients was low, and data indicated high individual variation between lung transplant recipients. Other contributors to reduced alpha diversity included antibiotics in combination with proton pump inhibitors, especially in gastric and oropharyngeal samples. CONCLUSIONS: Lung transplant recipients have reduced microbial diversity in gastric fluid (GF) and oropharynx compared with patients who did not undergo lung transplantation. The decreased alpha diversity in GF may be associated with dysmotility.


Assuntos
Transtornos de Deglutição/microbiologia , Esvaziamento Gástrico/fisiologia , Trato Gastrointestinal/microbiologia , Transplante de Pulmão , Microbiota , Sistema Respiratório/microbiologia , Transplantados , Pré-Escolar , Transtornos de Deglutição/fisiopatologia , Feminino , Seguimentos , Motilidade Gastrointestinal/fisiologia , Humanos , Masculino , Estudos Prospectivos
15.
Clin Transl Gastroenterol ; 12(12): e00434, 2021 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-34978997

RESUMO

INTRODUCTION: Bile reflux may cause for lung allograft rejection, yet there are no studies that determine (i) the relationship between gastric and lung bile concentrations, (ii) whether bile is present in lungs of nontransplant patients, (iii) the relationship between gastric dysmotility and lung bile, (iv) the impact of reflux therapies on lung bile, and (v) whether lung bile worsens outcomes in nontransplant patients. This study will address these gaps in the literature. METHODS: We prospectively recruited lung transplant (LTX) patients and nontransplant patients with respiratory symptoms (RP) and collected paired gastric and lung samples. Bile concentration and composition of samples was assessed using liquid chromatography-mass spectrometry. Bile results were compared with clinical parameters, including the presence of esophagitis, gastric dysmotility, and/or pathologic gastroesophageal reflux. RESULTS: Seventy patients (48 RP and 22 LTX) were recruited. Overall, 100% of gastric and 98% of bronchoalveolar lavage samples contained bile. The mean gastric bile concentrations in RP and LTX patients were 280 ± 703 nmol/L and 1,004 ± 1721 nmol/L, respectively (P = 0.02). There was no difference in lung bile concentrations between RP (9 ± 30 nmol/L) and LTX (11 ± 15 nmol/L, P = 0.7). Patients with delayed gastric emptying had higher lung bile concentrations (15.5 ± 18.8 nmol/L) than patients with normal gastric emptying (4.8 ± 5.7 nmol/L, P = 0.05) independently of reflux burden. Proton pump inhibitor use increased the proportion of unconjugated gastric bile acids. High lung bile concentrations were associated with an increased risk of hospitalization and longer hospital stays in RP patients (P < 0.05). DISCUSSION: Lung bile is almost universally present in symptomatic patients, and higher concentrations are associated with poorer respiratory outcomes.


Assuntos
Esofagite Péptica , Refluxo Gastroesofágico , Transplante de Pulmão , Bile , Refluxo Gastroesofágico/complicações , Humanos , Transplante de Pulmão/efeitos adversos , Fatores de Risco
16.
J Org Chem ; 85(17): 11030-11046, 2020 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-32786635

RESUMO

The high demand for new and efficient routes toward synthesis of nitrogen-containing heterocyclic scaffolds has inspired organic chemists to discover several methodologies over recent years. This Perspective highlights one standout approach, which involves the use of pyridotriazoles and related compounds in denitrogenative transformations. Readily available pyridotriazoles undergo ring-chain isomerization to produce uniquely reactive α-diazoimines. Such reactivity, enabled by metal catalysts, additives, or visible-light irradiation, can be applied in transannulation, insertion, cyclopropanation, and many other transformations.

17.
J Anim Breed Genet ; 137(1): 36-48, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31617268

RESUMO

The advent of metagenomics in animal breeding poses the challenge of statistically modelling the relationship between the microbiome, the host genetics and relevant complex traits. A set of structural equation models (SEMs) of a recursive type within a Markov chain Monte Carlo (MCMC) framework was proposed here to jointly analyse the host-metagenome-phenotype relationship. A non-recursive bivariate model was set as benchmark to compare the recursive model. The relative abundance of rumen microbes (RA), methane concentration (CH4 ) and the host genetics was used as a case of study. Data were from 337 Holstein cows from 12 herds in the north and north-west of Spain. Microbial composition from each cow was obtained from whole metagenome sequencing of ruminal content samples using a MinION device from Oxford Nanopore Technologies. Methane concentration was measured with Guardian® NG infrared gas monitor from Edinburgh Sensors during cow's visits to the milking automated system. A quarterly average from the methane eructation peaks for each cow was computed and used as phenotype for CH4 . Heritability of CH4 was estimated at 0.12 ± 0.01 in both the recursive and bivariate models. Likewise, heritability estimates for the relative abundance of the taxa overlapped between models and ranged between 0.08 and 0.48. Genetic correlations between the microbial composition and CH4 ranged from -0.76 to 0.65 in the non-recursive bivariate model and from -0.68 to 0.69 in the recursive model. Regardless of the statistical model used, positive genetic correlations with methane were estimated consistently for the seven genera pertaining to the Ciliophora phylum, as well as for those genera belonging to the Euryarchaeota (Methanobrevibacter sp.), Chytridiomycota (Neocallimastix sp.) and Fibrobacteres (Fibrobacter sp.) phyla. These results suggest that rumen's whole metagenome recursively regulates methane emissions in dairy cows and that both CH4 and the microbiota compositions are partially controlled by the host genotype.


Assuntos
Bovinos/metabolismo , Bovinos/microbiologia , Indústria de Laticínios , Metano/biossíntese , Microbiota , Modelos Estatísticos , Animais , Cadeias de Markov , Método de Monte Carlo
18.
J Cyst Fibros ; 19(4): 632-640, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-31870630

RESUMO

BACKGROUND: Circulating biomarkers reflective of lung disease activity and severity have the potential to improve patient care and accelerate drug development in CF. The objective of this study was to leverage banked specimens to test the hypothesis that blood-based biomarkers discriminate CF children segregated by lung disease severity. METHODS: Banked serum samples were selected from children who were categorized into two extremes of phenotype associated with lung function ('mild' or 'severe') based on CF-specific data and were matched on age, gender, CFTR genotype, and P. aeruginosa infection status. Targeted inflammatory proteins, lipids, and discovery metabolite profiles were measured in these serum samples. RESULTS: The severe cohort, characterized by a lower CF-specific FEV1 percentile, had significantly higher circulating concentrations of high sensitivity C-reactive protein, serum amyloid A, granulocyte colony stimulating factor, and calprotectin compared to the mild cohort. The mild cohort tended to have higher serum linoleic acid concentrations. The metabolite arabitol was lower in the severe cohort while other CF relevant metabolic pathways showed non-significant differences after adjusting for multiple comparisons. A sensitivity analysis to correct for biased estimates that may result from selecting subjects using an extremes of phenotype approach confirmed the protein biomarker findings. CONCLUSIONS: Circulating inflammatory proteins differ in CF children segregated by lung function. These findings serve to demonstrate the value of maintaining centralized, high quality patient derived samples for future research, with linkage to clinical information to answer testable hypotheses in biomarker development.


Assuntos
Biomarcadores/sangue , Fibrose Cística , Metabolômica/métodos , Proteína C-Reativa/análise , Criança , Correlação de Dados , Fibrose Cística/sangue , Fibrose Cística/diagnóstico , Fibrose Cística/fisiopatologia , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Feminino , Fator Estimulador de Colônias de Granulócitos/sangue , Humanos , Complexo Antígeno L1 Leucocitário/sangue , Masculino , Gravidade do Paciente , Pseudomonas aeruginosa/isolamento & purificação , Testes de Função Respiratória/métodos , Proteína Amiloide A Sérica/análise , Índice de Gravidade de Doença
19.
Anal Bioanal Chem ; 411(23): 5937-5949, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31280478

RESUMO

Dysregulated lipid species are linked to various disease pathologies and implicated as potential biomarkers for type 1 diabetes (T1D). However, it is challenging to comprehensively profile the blood specimen lipidome with full structural details of every lipid molecule. The commonly used reversed-phase liquid chromatography-tandem mass spectrometry (RPLC-MS/MS)-based lipidomics approach is powerful for the separation of individual lipid species, but lipids belonging to different classes may still co-elute and result in ion suppression and misidentification of lipids. Using offline mixed-mode and RPLC-based two-dimensional separations coupled with MS/MS, a comprehensive lipidomic profiling was performed on human sera pooled from healthy and T1D subjects. The elution order of lipid molecular species on RPLC showed good correlations to the total number of carbons in fatty acyl chains and total number of double bonds. This observation together with fatty acyl methyl ester analysis was used to enhance the confidence of identified lipid species. The final T1D serum lipid library database contains 753 lipid molecular species with accurate mass and RPLC retention time uniquely annotated for each of the species. This comprehensive human serum lipid library can serve as a database for high-throughput RPLC-MS-based lipidomic analysis of blood samples related to T1D and other childhood diseases. Graphical abstract.


Assuntos
Diabetes Mellitus Tipo 1/sangue , Lipídeos/sangue , Adolescente , Criança , Pré-Escolar , Cromatografia de Fase Reversa/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Humanos , Lactente , Lipídeos/análise , Espectrometria de Massas em Tandem/métodos
20.
J Am Chem Soc ; 141(20): 8104-8109, 2019 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-31046256

RESUMO

Due to the great value of amino alcohols, new methods for their synthesis are in high demand. Abundant aliphatic alcohols represent the ideal feedstock for the method development toward this important motif. To date, transition-metal-catalyzed approaches for the directed remote amination of alcohols have been well established. Yet, they have certain disadvantages such as the use of expensive catalysts and limited scope. Very recently, transition-metal-free visible-light-induced radical approaches have emerged as new powerful tools for directed remote amination of alcohols. Relying on 1,5-HAT reactivity, these methods are limited to ß - or δ-amination only. Herein, we report a novel transition-metal- and visible-light-free room-temperature radical approach for remote ß -, γ-, and δ-C(sp3)-N bond formation in aliphatic alcohols using mild basic conditions and readily available diazonium salt reagents.


Assuntos
Álcoois/química , Amino Álcoois/síntese química , Carbono/química , Ciclização , Radicais Livres/química , Hidrogênio/química , Cetonas/síntese química
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