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1.
Medicine (Baltimore) ; 99(27): e20794, 2020 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-32629663

RESUMO

BACKGROUND: Recently, trimethylamine N-oxide (TMAO) unexplained gut microbe has been proposed as a promising risk factor for atherosclerotic cardiovascular disease (CVD) pathogenesis and adverse events. The relationship of TMAO with coronary atherosclerotic burden has been evaluated in patients with stable coronary artery disease and ST-segment elevation myocardial infarction, but still needs to be explored in newly diagnosed non-ST-segment elevation myocardial infarction (NSTEMI) patients. MATERIAL AND METHODS: A prospective, single-center, SZ-NSTEMI trial (ChiCTR1900022366) is underway to investigate the relationship of TMAO with the severity and prognosis of coronary atherosclerosis in newly diagnosed NSTEMI patients who will undergo coronary angiography with primary percutaneous coronary intervention (pPCI). The primary endpoint of the study will be assessed the association of TMAO with coronary atherosclerotic severity quantify by the number of diseased coronary arteries and SYNTAX score after the coronary angiography. The secondary endpoints will be identified the TMAO as a prognostic biomarker for the short (1 month) and long-term (12 months) major cardiovascular and cerebrovascular events (MACCEs) rate including myocardial infarction, target vessel revascularization, stroke, heart failure, all-cause rehospitalization, and all-cause mortality after the pPCI. The blood samples will be collected from each patient before the procedure to measure the TMAO by isotope dilution high-performance liquid chromatography. In conclusion, SZ-NSTEMI will be the first cohort that will be investigated the association of TMAO with the severity and prognosis of coronary atherosclerotic burden in NSTEMI patients, aiming to identify TMAO as a predictor and a prognostic biomarker.


Assuntos
Aterosclerose/patologia , Doença da Artéria Coronariana/patologia , Metilaminas/sangue , Infarto do Miocárdio sem Supradesnível do Segmento ST/patologia , Adolescente , Adulto , Idoso , Biomarcadores , Doenças Cardiovasculares/patologia , Doença da Artéria Coronariana/cirurgia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Intervenção Coronária Percutânea , Estudos Prospectivos , Índice de Gravidade de Doença , Adulto Jovem
2.
Mol Pharmacol ; 98(2): 130-142, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32487733

RESUMO

Aberrant cellular Myc (c-Myc) is a common feature in the majority of human cancers and has been linked to oncogenic malignancies. Here, we developed a novel c-Myc-targeting compound, N, N-bis (5-ethyl-2-hydroxybenzyl) methylamine (EMD), and present evidence demonstrating its effectiveness in targeting c-Myc for degradation in human lung carcinoma. EMD exhibited strong cytotoxicity toward various human lung cancer cell lines, as well as chemotherapeutic-resistant patient-derived lung cancer cells, through apoptosis induction in comparison with chemotherapeutic drugs. The IC50 of EMD against lung cancer cells was approximately 60 µM. Mechanistically, EMD eliminated c-Myc in the cells and initiated caspase-dependent apoptosis cascade. Cycloheximide chase assay revealed that EMD tended to shorten the half-life of c-Myc by approximately half. The cotreatment of EMD with the proteasome inhibitor MG132 reversed its c-Myc-targeting effect, suggesting the involvement of ubiquitin-mediated proteasomal degradation in the process. We further verified that EMD strongly induced the ubiquitination of c-Myc and promoted protein degradation. c-Myc inhibition and apoptosis induction were additionally shown in hematologic malignant K562 cells, indicating the generality of the observed EMD effects. Altogether, we identified EMD as a novel potent compound targeting oncogenic c-Myc that may offer new opportunities for lung cancer treatment. SIGNIFICANCE STATEMENT: The deregulation of c-Myc is frequently associated with cancer progression. This study examined the effect of a new compound, N, N-bis (5-ethyl-2-hydroxybenzyl) methylamine (EMD), in targeting c-Myc in several lung cancer cell lines and drug-resistant primary lung cancer cells. EMD induced dramatic c-Myc degradation through a ubiquitin-proteasomal mechanism. The promising anticancer and c-Myc-targeted activities of EMD support its use in potential new approaches to treat c-Myc-driven cancer.


Assuntos
Antineoplásicos/síntese química , Neoplasias Pulmonares/metabolismo , Metilaminas/síntese química , Proteínas Proto-Oncogênicas c-myc/química , Proteínas Proto-Oncogênicas c-myc/metabolismo , Antineoplásicos/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Humanos , Células K562 , Neoplasias Pulmonares/tratamento farmacológico , Metilaminas/química , Metilaminas/farmacologia , Estrutura Molecular , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteólise , Proteínas Proto-Oncogênicas c-myc/efeitos dos fármacos , Ubiquitina/metabolismo
4.
Rev Med Suisse ; 16(695): 1120-1122, 2020 May 27.
Artigo em Francês | MEDLINE | ID: mdl-32462842

RESUMO

Patients come in consultation with a variety of complaints, some of which are unusual. We present here the case of a patient consulting for nauseating body odors for whom a diagnosis of trimethylaminuria could be found. This pathology, not very well known, may have important psychiatric and social repercussions. Genetics play a major role in diagnosis, while treatment consists essentially of various palliative measures.


Assuntos
Erros Inatos do Metabolismo/diagnóstico , Erros Inatos do Metabolismo/terapia , Metilaminas/urina , Humanos , Erros Inatos do Metabolismo/genética , Odorantes/análise
5.
Toxicol Lett ; 331: 42-52, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32464236

RESUMO

Synthetic cathinones abuse remains a serious public health problem. Kidney injury has been reported in intoxications associated with synthetic cathinones, but the molecular mechanisms involved have not been explored yet. In this study, the potential in vitro nephrotoxic effects of four commonly abused cathinone derivatives, namely pentedrone, 3,4-dimethylmethcatinone (3,4-DMMC), methylone and 3,4-methylenedioxypyrovalerone (MDPV), were assessed in the human kidney HK-2 cell line. All four derivatives elicited cell death in a concentration- and time-dependent manner, in the following order of potency: 3,4-DMMC >> MDPV > methylone ≈ pentedrone. 3,4-DMMC and methylone were selected to further elucidate the mechanisms behind synthetic cathinones-induced cell death. Both drugs elicited apoptotic cell death and prompted the formation of acidic vesicular organelles and autophagosomes in HK-2 cells. Moreover, the autophagy inhibitor 3-methyladenine significantly potentiated cell death, indicating that autophagy may serve as a cell survival mechanism that protects renal cells against synthetic cathinones toxicity. Both drugs triggered a rise in reactive oxygen and nitrogen species formation, which was completely prevented by antioxidant treatment with N­acetyl­L­cysteine or ascorbic acid. Importantly, these antioxidant agents significantly aggravated renal cell death induced by cathinone derivatives, most likely due to their autophagy-blocking properties. Taken together, our results support an intricate control of cell survival/death modulated by oxidative stress, apoptosis and autophagy in synthetic cathinones-induced renal injury.


Assuntos
Alcaloides/toxicidade , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Drogas Ilícitas/toxicidade , Rim/efeitos dos fármacos , Alcaloides/química , Benzodioxóis/química , Benzodioxóis/toxicidade , Técnicas de Cultura de Células , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Rim/metabolismo , Rim/patologia , Metanfetamina/análogos & derivados , Metanfetamina/química , Metanfetamina/toxicidade , Metilaminas/química , Metilaminas/toxicidade , Pentanonas/química , Pentanonas/toxicidade , Pirrolidinas/química , Pirrolidinas/toxicidade , Espécies Reativas de Nitrogênio/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Fatores de Tempo
6.
Toxicol Appl Pharmacol ; 395: 114970, 2020 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-32234388

RESUMO

Synthetic cathinones, such as methylone and pentedrone, are psychoactive derivatives of cathinone, sold in the internet as "plant food" or "bath salts". However, the level at which these compounds and their enantiomers cross the intestinal barrier has not been yet determined. Thus, the present study aimed to analyze the enantioselectivity on the permeability of these drugs through the intestinal barrier by using the Caco-2 cell line, a widely used in vitro model for drug permeability studies. To achieve this goal, an UHPLC-UV method was developed and validated to quantify both synthetic cathinones. The developed UHPLC-UV method revealed high selectivity and a linearity from 1 to 500 µM with correlation coefficients always higher than 0.999. The method has an accuracy that ranged between 89 and 107%, inter-day and intra-day precisions with coefficients of variation below 10%, limits of detection and quantification of 0.31 µM and 0.93 µM for methylone and 0.17 µM and 0.52 µM for pentedrone, respectively. In Caco-2 cells, a differentiated passage of the enantiomers across monolayer was observed for both cathinones. For pentedrone, the difference was observed after the first hour, being R-(-)-pentedrone the most permeable compound. Regarding methylone, the difference was noted after one hour and 30 min, with S-(-)-methylone being the most absorbed enantiomer. In conclusion, a fully validated method was successfully applied for studying the permeability of methylone and pentedrone enantiomers in an in vitro model of human intestine, which allowed to discover, for the first time, the enantioselectivity in drug permeability of this class of drugs.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Absorção Intestinal/fisiologia , Metanfetamina/análogos & derivados , Metilaminas/química , Metilaminas/farmacocinética , Pentanonas/química , Pentanonas/farmacocinética , Alcaloides/química , Células CACO-2 , Humanos , Metanfetamina/química , Metanfetamina/farmacocinética , Permeabilidade , Psicotrópicos , Sensibilidade e Especificidade , Estereoisomerismo , Relação Estrutura-Atividade
7.
Am J Physiol Heart Circ Physiol ; 318(5): H1272-H1282, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32243768

RESUMO

Cardiovascular disease is a major cause of morbidity and mortality among patients with chronic kidney disease (CKD). Trimethylamine-N-oxide (TMAO), a uremic metabolite that is elevated in the setting of CKD, has been implicated as a nontraditional risk factor for cardiovascular disease. While association studies have linked elevated plasma levels of TMAO to adverse cardiovascular outcomes, its direct effect on cardiac and smooth muscle function remains to be fully elucidated. We hypothesized that pathological concentrations of TMAO would acutely increase cardiac and smooth muscle contractility. These effects may ultimately contribute to cardiac dysfunction during CKD. High levels of TMAO significantly increased paced, ex vivo human cardiac muscle biopsy contractility (P < 0.05). Similarly, TMAO augmented contractility in isolated mouse hearts (P < 0.05). Reverse perfusion of TMAO through the coronary arteries via a Langendorff apparatus also enhanced cardiac contractility (P < 0.05). In contrast, the precursor molecule, trimethylamine (TMA), did not alter contractility (P > 0.05). Multiphoton microscopy, used to capture changes in intracellular calcium in paced, adult mouse hearts ex vivo, showed that TMAO significantly increased intracellular calcium fluorescence (P < 0.05). Interestingly, acute administration of TMAO did not have a statistically significant influence on isolated aortic ring contractility (P > 0.05). We conclude that TMAO directly increases the force of cardiac contractility, which corresponds with TMAO-induced increases in intracellular calcium but does not acutely affect vascular smooth muscle or endothelial function of the aorta. It remains to be determined if this acute inotropic action on cardiac muscle is ultimately beneficial or harmful in the setting of CKD.NEW & NOTEWORTHY We demonstrate for the first time that elevated concentrations of TMAO acutely augment myocardial contractile force ex vivo in both murine and human cardiac tissue. To gain mechanistic insight into the processes that led to this potentiation in cardiac contraction, we used two-photon microscopy to evaluate intracellular calcium in ex vivo whole hearts loaded with the calcium indicator dye Fluo-4. Acute treatment with TMAO resulted in increased Fluo-4 fluorescence, indicating that augmented cytosolic calcium plays a role in the effects of TMAO on force production. Lastly, TMAO did not show an effect on aortic smooth muscle contraction or relaxation properties. Our results demonstrate novel, acute, and direct actions of TMAO on cardiac function and help lay the groundwork for future translational studies investigating the complex multiorgan interplay involved in cardiovascular pathogenesis during CKD.


Assuntos
Coração/efeitos dos fármacos , Metilaminas/farmacologia , Contração Miocárdica , Idoso , Animais , Aorta/efeitos dos fármacos , Aorta/fisiologia , Feminino , Coração/fisiologia , Humanos , Masculino , Metilaminas/toxicidade , Camundongos , Pessoa de Meia-Idade , Músculo Liso/efeitos dos fármacos , Músculo Liso/fisiologia , Ratos , Ratos Sprague-Dawley
8.
Arterioscler Thromb Vasc Biol ; 40(5): 1239-1255, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32212854

RESUMO

OBJECTIVE: Gut microbial metabolism of dietary choline, a nutrient abundant in a Western diet, produces trimethylamine (TMA) and the atherothrombosis- and fibrosis-promoting metabolite TMA-N-oxide (TMAO). Recent clinical and animal studies reveal that elevated TMAO levels are associated with heightened risks for both cardiovascular disease and incident chronic kidney disease development. Despite this, studies focusing on therapeutically targeting gut microbiota-dependent TMAO production and its impact on preserving renal function are limited. Approach and Results: Herein we examined the impact of pharmacological inhibition of choline diet-induced gut microbiota-dependent production of TMA, and consequently TMAO, on renal tubulointerstitial fibrosis and functional impairment in a model of chronic kidney disease. Initial studies with a gut microbial choline TMA-lyase mechanism-based inhibitor, iodomethylcholine, confirmed both marked suppression of TMA generation, and consequently TMAO levels, and selective targeting of the gut microbial compartment (ie, both accumulation of the drug in intestinal microbes and limited systemic exposure in the host). Dietary supplementation of either choline or TMAO significantly augmented multiple indices of renal functional impairment and fibrosis associated with chronic subcutaneous infusion of isoproterenol. However, the presence of the gut microbiota-targeting inhibitor iodomethylcholine blocked choline diet-induced elevation in TMAO, and both significantly improved decline in renal function, and significantly attenuated multiple indices of tubulointerstitial fibrosis. Iodomethylcholine treatment also reversed many choline diet-induced changes in cecal microbial community composition associated with TMAO and renal functional impairment. CONCLUSIONS: Selective targeting of gut microbiota-dependent TMAO generation may prevent adverse renal structural and functional alterations in subjects at risk for chronic kidney disease.


Assuntos
Bactérias/efeitos dos fármacos , Proteínas de Bactérias/antagonistas & inibidores , Colina/farmacologia , Inibidores Enzimáticos/farmacologia , Microbioma Gastrointestinal/efeitos dos fármacos , Rim/efeitos dos fármacos , Liases/antagonistas & inibidores , Metilaminas/metabolismo , Insuficiência Renal Crônica/tratamento farmacológico , Animais , Bactérias/enzimologia , Proteínas de Bactérias/metabolismo , Colina/análogos & derivados , Modelos Animais de Doenças , Fibrose , Rim/metabolismo , Rim/patologia , Rim/fisiopatologia , Liases/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Insuficiência Renal Crônica/metabolismo , Insuficiência Renal Crônica/microbiologia , Insuficiência Renal Crônica/patologia
10.
Int Heart J ; 61(2): 355-363, 2020 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-32173700

RESUMO

Heart failure (HF) is a disease with high morbidity and mortality. In patients with HF, decreased cardiac output and blood redistribution results in decreased intestinal perfusion and destruction of intestinal barrier. Microorganisms and endotoxins can migrate into the blood circulation, aggravating systemic inflammation and HF. Trimethylamine N-oxide (TMAO) is highly closed to the occurrence of HF. However, the exact mechanism between TMAO and HF remains unclear.To investigate the role of TMAO in transverse-tubule (T-tubule) in the cultured cardiomyocytes.T-tubule imaging and analysis detected T-tubule network in cardiomyocytes. Ca2+ handling dysfunction was identified by confocal Ca2+ imaging. Tubulin densification and polymerization were assessed by western blot and immunofluorescent staining of cardiomyocytes.TMAO induced T-tubule network damage in cardiomyocytes and Ca2+ handling dysfunction in cardiomyocytes under the TMAO stress via promoting tubulin densification and polymerization and therefore Junctophilin-2 (JPH2) redistribution. Mice treated with TMAO represented cardiac dysfunction and T-tubule network disorganization.TMAO impairs cardiac function via the promotion of tubulin polymerization, subsequent translocation of JPH2, and T-tubule remodeling, which provides a novel mechanism for the relationship between HF and elevated TMAO.


Assuntos
Insuficiência Cardíaca/metabolismo , Metilaminas/toxicidade , Microtúbulos/metabolismo , Miócitos Cardíacos/metabolismo , Animais , Cálcio/metabolismo , Células Cultivadas , Acoplamento Excitação-Contração , Insuficiência Cardíaca/etiologia , Masculino , Proteínas de Membrana/metabolismo , Camundongos Endogâmicos C57BL , Microtúbulos/efeitos dos fármacos , Miócitos Cardíacos/efeitos dos fármacos , Tubulina (Proteína)/metabolismo
11.
Am J Clin Nutr ; 111(6): 1226-1234, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32055828

RESUMO

BACKGROUND: Trimethylamine N-oxide (TMAO), a compound derived from diet and metabolism by the gut microbiome, has been associated with several chronic diseases, although the mechanisms of action are not well understood and few human studies have investigated microbes involved in its production. OBJECTIVES: Our study aims were 1) to investigate associations of TMAO and its precursors (choline, carnitine, and betaine) with inflammatory and cardiometabolic risk biomarkers; and 2) to identify fecal microbiome profiles associated with TMAO. METHODS: We conducted a cross-sectional analysis using data collected from 1653 participants (826 men and 827 women, aged 60-77 y) in the Multiethnic Cohort Study. Plasma concentrations of TMAO and its precursors were measured by LC-tandem MS. We also analyzed fasting blood for markers of inflammation, glucose and insulin, cholesterol, and triglycerides (TGs), and further measured blood pressure. Fecal microbiome composition was evaluated by sequencing the 16S ribosomal RNA gene V1-V3 region. Associations of TMAO and its precursors with disease risk biomarkers were assessed by multivariable linear regression, whereas associations between TMAO and the fecal microbiome were assessed by permutational multivariate ANOVA and hurdle regression models using the negative binomial distribution. RESULTS: Median (IQR) concentration of plasma TMAO was 3.05 µmol/L (2.10-4.60 µmol/L). Higher concentrations of TMAO and carnitine, and lower concentrations of betaine, were associated with greater insulin resistance (all P < 0.02). Choline was associated with higher systolic blood pressure, TGs, lipopolysaccharide-binding protein, and lower HDL cholesterol (P ranging from <0.001 to 0.03), reflecting an adverse cardiometabolic risk profile. TMAO was associated with abundance of 13 genera (false discovery rate < 0.05), including Prevotella, Mitsuokella, Fusobacterium, Desulfovibrio, and bacteria belonging to the families Ruminococcaceae and Lachnospiraceae, as well as the methanogen Methanobrevibacter smithii. CONCLUSIONS: Plasma TMAO concentrations were associated with a number of trimethylamine-producing bacterial taxa, and, along with its precursors, may contribute to inflammatory and cardiometabolic risk pathways.


Assuntos
Betaína/sangue , Doenças Cardiovasculares/sangue , Carnitina/sangue , Colina/sangue , Microbioma Gastrointestinal , Metilaminas/sangue , Adiposidade , Idoso , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/metabolismo , Biomarcadores/sangue , Doenças Cardiovasculares/etnologia , Doenças Cardiovasculares/imunologia , Doenças Cardiovasculares/microbiologia , Estudos de Coortes , Estudos Transversais , Feminino , Humanos , Masculino , Metilaminas/metabolismo , Pessoa de Meia-Idade
13.
APMIS ; 128(5): 353-366, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32108960

RESUMO

The increasing prevalence of cardiovascular diseases cannot adequately be explained by traditional risk factors. Recently, accumulating evidence has suggested that gut microbiota-derived numerous metabolites are contributors to atherosclerotic events. Among them, the role of trimethylamine N-oxide (TMAO) in promoting atherosclerosis has gained attention. TMAO is reported to exert the proatherogenic effects by impacting on the traditional risk factors of atherosclerosis and is associated with high risk of cardiovascular events. Besides that, TMAO is involved in the complex pathological processes of atherosclerotic lesion formation, such as endothelial dysfunction, platelet activation and thrombus generation. In light of these promising findings, TMAO may serve as a potential target for atherosclerosis prevention and treatment, which is conceptually novel, when compared with existing traditional treatments. It is likely that regulating TMAO production and associated gut microbiota may become a promising strategy for the anti-atherosclerosis therapy.


Assuntos
Aterosclerose/metabolismo , Aterosclerose/microbiologia , Microbioma Gastrointestinal , Metilaminas/metabolismo , Animais , Humanos , Metilaminas/efeitos adversos , Fatores de Risco
15.
Phys Chem Chem Phys ; 22(9): 5301-5313, 2020 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-32096507

RESUMO

Biomedical industries are widely exploring the use of thermo-responsive polymers (TRPs) in the advanced development of drug delivery and in many other pharmaceutical applications. There is a great need to investigate the use of less toxic and more (bio-)compatible TRPs employing several additives, which could modify the conformational transition behavior of TRPs in aqueous solution. To move forward in this aspect, we have chosen the less toxic bio-based polymer poly(N-vinylcaprolactam) (PVCL) and three different methylamine-based osmolytes, trimethylamine N-oxide (TMAO), betaine and sarcosine, in order to investigate their particular interactions with the polymer segments in PVCL and therefore the corresponding changes in the thermo-responsive conformational behavior. Several biophysical techniques, UV-visible spectroscopy, fluorescence spectroscopy, dynamic light scattering (DLS) and laser Raman spectroscopy, as well as classical computer simulation methods such as molecular dynamics are employed in the current work. All the studied methylamines are found to favor the hydrophobic collapse of the polymer thus stabilizing the globular state of PVCL. Sarcosine is observed to cause the maximum decrease in lower critical solution temperature (LCST) of PVCL followed by TMAO and then betaine. The differences observed in the LCST values of PVCL in the presence of these molecules can be attributed to the different polymer-osmolyte interactions. The less sterically hindered N atom in the case of sarcosine causes a significant difference in the phase transition temperature values of PVCL compared to betaine and TMAO, where the nitrogen atom is buried by three methyl groups attached to it.


Assuntos
Caprolactama/análogos & derivados , Metilaminas/química , Simulação de Dinâmica Molecular , Polímeros/química , Betaína/química , Caprolactama/química , Interações Hidrofóbicas e Hidrofílicas , Conformação Molecular , Transição de Fase , Sarcosina/química , Temperatura de Transição , Água/química
16.
Environ Sci Technol ; 54(4): 2182-2191, 2020 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-32020793

RESUMO

Potable reuse of wastewater is expanding, and ozonation for water reuse is becoming more common, either as a preoxidant before membranes or as part of ozone/biological activated carbon (O3/BAC) systems. However, previous research has demonstrated that ozone drastically increases the formation potential of genotoxic halonitromethanes (HNMs), including during O3/BAC. Chloropicrin, the most common HNM, is synthesized by chlorinating nitromethane, suggesting that nitromethane may be the immediate precursor of chloropicrin, although nitromethane is unlikely to occur naturally in wastewater. We hypothesized that wastewater ozonation forms nitromethane, which would be the key intermediate toward HNMs. Ozonation of wastewater effluent was shown to form abundant nitromethane, which explained the majority (in one case, all) of subsequent chloropicrin formation. Next, we investigated a suspected category of nitromethane precursor: stimulant drugs, such as ephedrine and methamphetamine, and certain antidepressants. These drugs all feature N-methylamine functional groups, and certain N-alkylamines have been shown to produce primary nitroalkanes upon ozonation. Ozonation of N-methylamine drugs ubiquitously formed nitromethane, typically at >50% yield. Subsequent chlorination converted nitromethane to chloropicrin. The reaction mechanism was investigated to understand the variation in nitromethane yield between different precursors. These results suggest that nitromethane fate during reuse and nitromethane control should be investigated.


Assuntos
Ozônio , Poluentes Químicos da Água , Purificação da Água , Metano/análogos & derivados , Metilaminas , Nitroparafinas , Águas Residuárias
17.
Environ Sci Pollut Res Int ; 27(9): 9028-9037, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31919828

RESUMO

Trimethylamine (TMA) is an odorous volatile organic compound emitted by industries. Algal-based biotechnologies have been proven as a feasible alternative for wastewater treatment, although their application to abate polluted air emissions is still scarce. This work comparatively assessed the removal of TMA in a conventional bacterial bubble column bioreactor (BC) and a novel algal-bacterial bubble column photobioreactor (PBC). The PBC exhibited a superior TMA abatement performance compared to the conventional BC. In this sense, the BC reached a removal efficiency (RE) and an elimination capacity (EC) of 78% and 12.1 g TMA m-3 h-1, respectively, while the PBC achieved a RE of 97% and a EC of 16.0 g TMA m-3·h-1 at an empty bed residence time (EBRT) of 2 min and a TMA concentration ~500 mg m-3. The outstanding performance of the PBC allowed to reduce the operating EBRT to 1.5 and 1 min while maintaining high REs of 98 and 94% and ECs of 21.2 and 28.1 g m-3·h-1, respectively. Moreover, the PBC improved the quality of the gas and liquid effluents discharged, showing a net CO2 consumption and decreasing by ~ 30% the total nitrogen concentration in the liquid effluent via biomass assimilation. A high specialization of the bacterial community was observed in the PBC, Mumia and Aquamicrobium sp. being the most abundant genus within the main phyla identified. GraphicalAbstract.


Assuntos
Microalgas , Fotobiorreatores , Biomassa , Metilaminas , Águas Residuárias
18.
Arterioscler Thromb Vasc Biol ; 40(3): 751-765, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31941382

RESUMO

OBJECTIVES: Vascular calcification is highly prevalent in patients with chronic kidney disease. Increased plasma trimethylamine N-oxide (TMAO), a gut microbiota-dependent product, concentrations are found in patients undergoing hemodialysis. However, a clear mechanistic link between TMAO and vascular calcification is not yet established. In this study, we investigate whether TMAO participates in the progression of vascular calcification using in vitro, ex vivo, and in vivo models. Approach and Results: Alizarin red staining revealed that TMAO promoted calcium/phosphate-induced calcification of rat and human vascular smooth muscle cells in a dose-dependent manner, and this was confirmed by calcium content assay. Similarly, TMAO upregulated the expression of bone-related molecules including Runx2 (Runt-related transcription factor 2) and BMP2 (bone morphogenetic protein-2), suggesting that TMAO promoted osteogenic differentiation of vascular smooth muscle cells. In addition, ex vivo study also showed the positive regulatory effect of TMAO on vascular calcification. Furthermore, we found that TMAO accelerated vascular calcification in rats with chronic kidney disease, as indicated by Mico-computed tomography analysis, alizarin red staining and calcium content assay. By contrast, reducing TMAO levels by antibiotics attenuated vascular calcification in chronic kidney disease rats. Interestingly, TMAO activated NLRP3 (nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3) inflammasome and NF-κB (nuclear factor κB) signals during vascular calcification. Inhibition of NLRP3 inflammasome and NF-κB signals attenuated TMAO-induced vascular smooth muscle cell calcification. CONCLUSIONS: This study for the first time demonstrates that TMAO promotes vascular calcification through activation of NLRP3 inflammasome and NF-κB signals, suggesting the potential link between gut microbial metabolism and vascular calcification. Reducing the levels of TMAO could become a potential treatment strategy for vascular calcification in chronic kidney disease.


Assuntos
Inflamassomos/efeitos dos fármacos , Metilaminas/toxicidade , Músculo Liso Vascular/efeitos dos fármacos , Miócitos de Músculo Liso/efeitos dos fármacos , NF-kappa B/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Osteogênese/efeitos dos fármacos , Calcificação Vascular/induzido quimicamente , Adulto , Idoso , Animais , Antibacterianos/farmacologia , Aorta Torácica/efeitos dos fármacos , Aorta Torácica/metabolismo , Aorta Torácica/patologia , Células Cultivadas , Modelos Animais de Doenças , Feminino , Humanos , Inflamassomos/metabolismo , Masculino , Metilaminas/metabolismo , Pessoa de Meia-Idade , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/patologia , Miócitos de Músculo Liso/metabolismo , Miócitos de Músculo Liso/patologia , Insuficiência Renal Crônica/complicações , Insuficiência Renal Crônica/metabolismo , Transdução de Sinais , Artérias da Tíbia/efeitos dos fármacos , Artérias da Tíbia/metabolismo , Artérias da Tíbia/patologia , Técnicas de Cultura de Tecidos , Calcificação Vascular/metabolismo , Calcificação Vascular/patologia , Calcificação Vascular/prevenção & controle
20.
Chem Commun (Camb) ; 56(8): 1187-1190, 2020 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-31922177

RESUMO

Trimethylamine N-oxide is found to be effective in regulating the interaction between microtubules and kinesins over a wide temperature range. The lifetime of the motility of microtubules on kinesins at high temperatures is prolonged using trimethylamine N-oxide. The activation energy of microtubule motility is increased by trimethylamine N-oxide. Prolonged operation at high temperatures decreased the activation energy of MT motility despite the increase in concentration of trimethylamine N-oxide.


Assuntos
Cinesina/metabolismo , Metilaminas/farmacologia , Microtúbulos/metabolismo , Temperatura , Cinesina/química , Cinética , Metilaminas/química , Microtúbulos/química
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