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2.
BMJ Case Rep ; 17(2)2024 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-38367997

RESUMO

A man in his late 70s with chronic myelomonocytic leukaemia presented for evaluation of acute leukaemic transformation and initiation of cytoreductive therapy after being found to have asymptomatic hyperleucocytosis. Within 24 hours, the patient developed vasopressor-refractory shock, severe lactic acidosis and multiorgan failure. Serial echocardiographic assessments revealed interval enlargement of the right ventricle with development of the McConnell's sign, and abdominal CT showed diffuse bowel wall thickening, likely due to ischaemia. CT angiography excluded pulmonary embolism or occlusion of intra-abdominal arteries. Despite aggressive care, the patient died from cardiovascular collapse within 8 hours of the onset of hypotension. An autopsy revealed extensive infiltration of early myeloid cells in pulmonary, myocardial, hepatic and intestinal microvasculature. This case illustrates different mechanisms by which leucostasis causes acute cardiovascular collapse and stresses the emergent nature of this diagnosis.


Assuntos
Embolia Pulmonar , Choque , Masculino , Humanos , Embolia Pulmonar/diagnóstico , Ecocardiografia , Pulmão/diagnóstico por imagem , Choque/etiologia , Artérias
3.
Am J Physiol Lung Cell Mol Physiol ; 325(6): L776-L787, 2023 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-37814791

RESUMO

Asthma susceptibility is influenced by environmental, genetic, and epigenetic factors. DNA methylation is one form of epigenetic modification that regulates gene expression and is both inherited and modified by environmental exposures throughout life. Prenatal development is a particularly vulnerable time period during which exposure to maternal asthma increases asthma risk in offspring. How maternal asthma affects DNA methylation in offspring and what the consequences of differential methylation are in subsequent generations are not fully known. In this study, we tested the effects of grandmaternal house dust mite (HDM) allergen sensitization during pregnancy on airway physiology and inflammation in HDM-sensitized and challenged second-generation mice. We also tested the effects of grandmaternal HDM sensitization on tissue-specific DNA methylation in allergen-naïve and -sensitized second-generation mice. Descendants of both allergen- and vehicle-exposed grandmaternal founders exhibited airway hyperreactivity after HDM sensitization. However, grandmaternal allergen sensitization significantly potentiated airway hyperreactivity and altered the epigenomic trajectory in second-generation offspring after HDM sensitization compared with HDM-sensitized offspring from vehicle-exposed founders. As a result, biological processes and signaling pathways associated with epigenetic modifications were distinct between lineages. A targeted analysis of pathway-associated gene expression found that Smad3 was significantly dysregulated as a result of grandmaternal allergen sensitization. These data show that grandmaternal allergen exposure during pregnancy establishes a unique epigenetic trajectory that reprograms allergen responses in second-generation offspring and may contribute to asthma risk.NEW & NOTEWORTHY Asthma susceptibility is influenced by environmental, genetic, and epigenetic factors. This study shows that maternal allergen exposure during pregnancy promotes unique epigenetic trajectories in second-generation offspring at baseline and in response to allergen sensitization, which is associated with the potentiation of airway hyperreactivity. These effects are one mechanism by which maternal asthma may influence the inheritance of asthma risk.


Assuntos
Asma , Efeitos Tardios da Exposição Pré-Natal , Gravidez , Humanos , Feminino , Camundongos , Animais , Alérgenos , Epigenômica , Efeitos Tardios da Exposição Pré-Natal/genética , Asma/genética , Suscetibilidade a Doenças , Epigênese Genética , Pyroglyphidae
4.
Am J Respir Cell Mol Biol ; 67(1): 89-98, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35363997

RESUMO

Asthma is a heterogeneous inflammatory airway disease that develops in response to a combination of genetic predisposition and environmental exposures. Patients with asthma are grouped into phenotypes with shared clinical features and biomarker profiles to help tailor specific therapies. However, factors driving development of specific phenotypes are poorly understood. Prenatal exposure to maternal asthma is a unique risk factor for childhood asthma. Here we tested whether maternal asthma skews asthma phenotypes in offspring. We compared airway hyperreactivity and inflammatory and neurotrophin lung signatures before and after allergen challenge in offspring born to mice exposed to house dust mite (HDM) or vehicle during pregnancy. Maternal HDM exposure potentiated offspring responses to HDM allergen, significantly increasing both airway hyperreactivity and airway eosinophilia compared with control mice. Maternal HDM exposure broadly skewed the offspring cytokine response from a classic allergen-induced T-helper cell type 2 (Th2)-predominant signature in HDM-treated offspring of vehicle-exposed mothers, toward a mixed Th17/Th1 phenotype in HDM-treated offspring of HDM-exposed mothers. Morphologic analysis determined that maternal HDM exposure also increased airway epithelial sensory nerve density and induced distinct neurotrophin signatures to support airway hyperinnervation. Our results demonstrate that maternal allergen exposure alters fetal lung development and promotes a unique inflammatory phenotype at baseline and in response to allergen that persists into adulthood.


Assuntos
Asma , Pyroglyphidae , Alérgenos , Animais , Asma/genética , Modelos Animais de Doenças , Feminino , Pulmão , Camundongos , Fatores de Crescimento Neural/genética , Fenótipo , Gravidez
5.
Sci Rep ; 12(1): 5006, 2022 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-35322058

RESUMO

We report subpopulations of airway parasympathetic neurons expressing substance P, neuronal nitric oxide synthase, and tyrosine hydroxylase, highlighting unexplored heterogeneity in this population. These neurotransmitter-specific subpopulations did not form intraganglionic interneurons, but rather, extended outside the ganglia, into the airways, to distant innervation targets. Our experiments demonstrate the utility of multicolor labeling to characterize airway innervation, allowing us to confirm the extensive heterogeneity of postganglionic parasympathetic neurons. These methods will facilitate future investigations of neurophysiology and neural contributions to airway disease.


Assuntos
Neurônios , Óxido Nítrico Sintase , Gânglios , Sistema Respiratório , Tirosina 3-Mono-Oxigenase
6.
J Leukoc Biol ; 108(1): 113-121, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32040236

RESUMO

Asthma is a chronic inflammatory airway disease characterized by airway hyperresponsiveness, inflammation, and remodeling. Asthma often develops during childhood and causes lifelong decrements in lung function and quality of life. Risk factors for childhood asthma are numerous and include genetic, epigenetic, developmental, and environmental factors. Uncontrolled maternal asthma during pregnancy exposes the developing fetus to inflammatory insults, which further increase the risk of childhood asthma independent of genetic predisposition. This review focuses on the role of maternal asthma in the development of asthma in offspring. We will present maternal asthma as a targetable and modifiable risk factor for childhood asthma and discuss the mechanisms by which maternal inflammation increases childhood asthma risk. Topics include how exposure to maternal asthma in utero shapes structural lung development with a special emphasis on airway nerves, how maternal type-2 cytokines such as IL-5 activate the fetal immune system, and how changes in lung and immune cell development inform responses to aero-allergens later in life. Finally, we highlight emerging evidence that maternal asthma establishes a unique "asthma signature" in the airways of children, leading to novel mechanisms of airway hyperreactivity and inflammatory cell responses.


Assuntos
Asma/sangue , Inflamação/sangue , Asma/fisiopatologia , Criança , Citocinas/metabolismo , Feminino , Humanos , Inflamação/fisiopatologia , Pulmão/embriologia , Pulmão/inervação , Pulmão/fisiopatologia , Terapia de Alvo Molecular , Gravidez , Fatores de Risco
7.
Am J Respir Cell Mol Biol ; 62(4): 493-502, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31821769

RESUMO

Asthma is characterized by airway hyperreactivity and inflammation. In the lungs, parasympathetic and sensory nerves control airway tone and induce bronchoconstriction. Dysregulation of these nerves results in airway hyperreactivity. Humans with eosinophilic asthma have significantly increased sensory nerve density in airway epithelium, suggesting that type 2 cytokines and inflammatory cells promote nerve growth. Similarly, mice with congenital airway eosinophilia also have airway hyperreactivity and increased airway sensory nerve density. Here, we tested whether this occurs during development. We show that transgenic mice that overexpress IL-5, a cytokine required for eosinophil hematopoiesis, give birth to wild-type offspring that have significantly increased airway epithelial nerve density and airway hyperreactivity that persists into adulthood. These effects are caused by in utero exposure to maternal IL-5 and resulting fetal eosinophilia. Allergen exposure of these adult wild-type offspring results in severe airway hyperreactivity, leading to fatal reflex bronchoconstriction. Our results demonstrate that fetal exposure to IL-5 is a developmental origin of airway hyperreactivity, mediated by hyperinnervation of airway epithelium.


Assuntos
Interleucina-5/metabolismo , Pulmão/inervação , Pulmão/metabolismo , Nervo Vago/metabolismo , Nervo Vago/fisiologia , Animais , Asma/metabolismo , Asma/fisiopatologia , Hiper-Reatividade Brônquica/metabolismo , Hiper-Reatividade Brônquica/fisiopatologia , Líquido da Lavagem Broncoalveolar , Broncoconstrição/fisiologia , Eosinófilos/metabolismo , Eosinófilos/fisiologia , Feminino , Inflamação/metabolismo , Inflamação/fisiopatologia , Pulmão/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Eosinofilia Pulmonar/metabolismo , Eosinofilia Pulmonar/fisiopatologia , Mucosa Respiratória/metabolismo , Mucosa Respiratória/fisiologia
8.
Transfus Med Hemother ; 43(2): 114-9, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27226793

RESUMO

Allergic asthma and allergic rhinitis are inflammatory diseases of the respiratory tract characterized by an excessive type-2 T helper cell (Th2) immune response. Toll-like receptor 7 (TLR7) is a single-stranded viral RNA receptor expressed in the airway that initiates a Th1 immune response and has garnered interest as a novel therapeutic target for treatment of allergic airway diseases. In animal models, synthetic TLR7 agonists reduce airway hyperreactivity, eosinophilic inflammation, and airway remodeling while decreasing Th2-associated cytokines. Furthermore, activation of TLR7 rapidly relaxes airway smooth muscle via production of nitric oxide. Thus, TLR7 has dual bronchodilator and anti-inflammatory effects. Two TLR7 ligands with promising pharmacologic profiles have entered clinical trials for the treatment of allergic rhinitis. Moreover, TLR7 agonists are potential antiviral therapies against respiratory viruses. TLR7 agonists enhance influenza vaccine efficacy and also reduce viral titers when given during an active airway infection. In this review, we examine the current data supporting TLR7 as a therapeutic target in allergic airway diseases.

9.
Artigo em Inglês | MEDLINE | ID: mdl-24657723

RESUMO

The composition of the typical commercial diet fed to zebrafish can dramatically vary. By utilizing defined diets we sought to answer two questions: 1) How does the embryonic zebrafish transcriptome change when the parental adults are fed a commercial lab diet compared with a sufficient, defined diet (E+)? 2) Does a vitamin E-deficient parental diet (E-) further change the embryonic transcriptome? We conducted a global gene expression study using embryos from zebrafish fed a commercial (Lab), an E+ or an E- diet. To capture differentially expressed transcripts prior to onset of overt malformations observed in E- embryos at 48h post-fertilization (hpf), embryos were collected from each group at 36hpf. Lab embryos differentially expressed (p<0.01) 946 transcripts compared with the E+ embryos, and 2656 transcripts compared with the E- embryos. The differences in protein, fat and micronutrient intakes in zebrafish fed the Lab compared with the E+ diet demonstrate that despite overt morphologic consistency, significant differences in gene expression occurred. Moreover, functional analysis of the significant transcripts in the E- embryos suggested perturbed energy metabolism, leading to overt malformations and mortality. Thus, these findings demonstrate that parental zebrafish diet has a direct impact on the embryonic transcriptome.


Assuntos
Dieta , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Transcriptoma/genética , Vitamina E/farmacologia , Peixe-Zebra/embriologia , Animais , Embrião não Mamífero , Feminino , Masculino , Transcriptoma/efeitos dos fármacos
10.
Free Radic Biol Med ; 66: 13-9, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23920314

RESUMO

α-Tocopherol is a lipid-soluble antioxidant that is specifically required for reproduction and embryogenesis. However, since its discovery, α-tocopherol's specific biologic functions, other than as an antioxidant, and the mechanism(s) mediating its requirement for embryogenesis remain unknown. As an antioxidant, α-tocopherol protects polyunsaturated fatty acids (PUFAs) from lipid peroxidation. α-Tocopherol is probably required during embryonic development to protect PUFAs that are crucial to development, specifically arachidonic (ARA) and docosahexaenoic (DHA) acids. Additionally, ARA and DHA are metabolized to bioactive lipid mediators via lipoxygenase enzymes, and α-tocopherol may directly protect, or it may mediate the production and/or actions of, these lipid mediators. In this review, we discuss how α-tocopherol (1) prevents the nonspecific, radical-mediated peroxidation of PUFAs, (2) functions within a greater antioxidant network to modulate the production and/or function of lipid mediators derived from 12- and 12/15-lipoxygenases, and (3) modulates 5-lipoxygenase activity. The application and implication of such interactions are discussed in the context of α-tocopherol requirements during embryogenesis.


Assuntos
Desenvolvimento Embrionário , Ácidos Graxos Insaturados/metabolismo , Lipoxigenases/metabolismo , alfa-Tocoferol/metabolismo , Aborto Espontâneo/etiologia , Animais , Antioxidantes/metabolismo , Feminino , Radicais Livres , Humanos , Metabolismo dos Lipídeos , Peroxidação de Lipídeos , Gravidez , Deficiência de Vitamina E/complicações
11.
Artigo em Inglês | MEDLINE | ID: mdl-23570751

RESUMO

We hypothesized that zebrafish (Danio rerio) undergoing long-term vitamin E deficiency with marginal vitamin C status would develop myopathy resulting in impaired swimming. Zebrafish were fed for 1 y a defined diet without (E-) and with (E+) vitamin E (500 mg α-tocopherol/kg diet). For the last 150 days, dietary ascorbic acid concentrations were decreased from 3500 to 50 mg/kg diet and the fish sampled periodically to assess ascorbic acid concentrations. The ascorbic acid depletion curves were faster in the E- compared with E+ fish (P < 0.0001); the estimated half-life of depletion in the E- fish was 34 days, while in it was 55 days in the E+ fish. To assess swimming behavior, zebrafish were monitored individually following a "startle-response" stimulus, using computer and video technology. Muscle histopathology was assessed using hematoxylin and eosin staining on paramedian sections of fixed zebrafish. At study end, E- fish contained 300-fold less α-tocopherol (p < 0.0001), half the ascorbic acid (p = 0.0001) and 3-fold more malondialdehyde (p = 0.0005) than did E+ fish. During the first minute following a tap stimulus (p < 0.05), E+ fish swam twice as far as did E- fish. In the E- fish, the sluggish behavior was associated with a multifocal, polyphasic, degenerative myopathy of the skeletal muscle. The myopathy severity ranged from scattered acute necrosis to widespread fibrosis and was accompanied by increased anti-hydroxynonenal staining. Thus, vitamin E deficiency in zebrafish causes increased oxidative stress and a secondary depletion of ascorbic acid, resulting in severe damage to muscle tissue and impaired muscle function.


Assuntos
Deficiência de Ácido Ascórbico/etiologia , Comportamento Animal/fisiologia , Doenças Musculares/etiologia , Deficiência de Vitamina E/complicações , Peixe-Zebra/metabolismo , Animais , Ácido Ascórbico/administração & dosagem , Ácido Ascórbico/análise , Ácido Ascórbico/metabolismo , Fibrose/patologia , Meia-Vida , Malondialdeído/metabolismo , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Necrose/patologia , Estresse Oxidativo , Índice de Gravidade de Doença , Natação , Peixe-Zebra/fisiologia , alfa-Tocoferol/metabolismo
12.
Redox Biol ; 2: 105-13, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24416717

RESUMO

To test the hypothesis that embryogenesis depends upon α-tocopherol (E) to protect embryo polyunsaturated fatty acids (PUFAs) from lipid peroxidation, new methodologies were applied to measure α-tocopherol and fatty acids in extracts from saponified zebrafish embryos. A solid phase extraction method was developed to separate the analyte classes, using a mixed mode cartridge (reverse phase, π-π bonding, strong anion exchange), then α-tocopherol and cholesterol were measured using standard techniques, while the fatty acids were quantitated using a novel, reverse phase liquid chromatography-mass spectrometry (LC-MS) approach. We also determined if α-tocopherol status alters embryonic lipid peroxidation products by analyzing 24 different oxidized products of arachidonic or docosahexaenoic (DHA) acids in embryos using LC with hybrid quadrupole-time of flight MS. Adult zebrafish were fed E- or E+ diets for 4 months, and then were spawned to obtain E- and E+ embryos. Between 24 and 72 hours post-fertilization (hpf), arachidonic acid decreased 3-times faster in E- (21 pg/h) compared with E+ embryos (7 pg/h, P<0.0001), while both α-tocopherol and DHA concentrations decreased only in E- embryos. At 36 hpf, E- embryos contained double the 5-hydroxy-eicosatetraenoic acids and 7-hydroxy-DHA concentrations, while other hydroxy-lipids remained unchanged. Vitamin E deficiency during embryogenesis depleted DHA and arachidonic acid, and increased hydroxy-fatty acids derived from these PUFA, suggesting that α-tocopherol is necessary to protect these critical fatty acids.


Assuntos
Ácido Araquidônico/análise , Cromatografia Líquida de Alta Pressão , Ácidos Docosa-Hexaenoicos/análise , Espectrometria de Massas , Peixe-Zebra/metabolismo , Animais , Ácido Araquidônico/isolamento & purificação , Ácido Araquidônico/metabolismo , Colesterol/análise , Colesterol/isolamento & purificação , Ácidos Docosa-Hexaenoicos/isolamento & purificação , Ácidos Docosa-Hexaenoicos/metabolismo , Embrião não Mamífero/metabolismo , Ácidos Graxos Insaturados/análise , Ácidos Graxos Insaturados/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Extração em Fase Sólida , Vitamina E/farmacologia , Deficiência de Vitamina E/metabolismo , Deficiência de Vitamina E/patologia , Peixe-Zebra/crescimento & desenvolvimento , alfa-Tocoferol/análise
13.
PLoS One ; 7(10): e47402, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23077608

RESUMO

The hepatic α-tocopherol transfer protein (TTP) is required for optimal α-tocopherol bioavailability in humans; mutations in the human TTPA gene result in the heritable disorder ataxia with vitamin E deficiency (AVED, OMIM #277460). TTP is also expressed in mammalian uterine and placental cells and in the human embryonic yolk-sac, underscoring TTP's significance during fetal development. TTP and vitamin E are essential for productive pregnancy in rodents, but their precise physiological role in embryogenesis is unknown. We hypothesize that TTP is required to regulate delivery of α-tocopherol to critical target sites in the developing embryo. We tested to find if TTP is essential for proper vertebrate development, utilizing the zebrafish as a non-placental model. We verify that TTP is expressed in the adult zebrafish and its amino acid sequence is homologous to the human ortholog. We show that embryonic transcription of TTP mRNA increases >7-fold during the first 24 hours following fertilization. In situ hybridization demonstrates that Ttpa transcripts are localized in the developing brain, eyes and tail bud at 1-day post fertilization. Inhibiting TTP expression using oligonucleotide morpholinos results in severe malformations of the head and eyes in nearly all morpholino-injected embryos (88% compared with 5.6% in those injected with control morpholinos or 1.7% in non-injected embryos). We conclude that TTP is essential for early development of the vertebrate central nervous system.


Assuntos
Proteínas de Transporte/genética , Desenvolvimento Embrionário/genética , Vitamina E/metabolismo , Peixe-Zebra/crescimento & desenvolvimento , alfa-Tocoferol/metabolismo , Animais , Proteínas de Transporte/fisiologia , Sistema Nervoso Central/crescimento & desenvolvimento , Desenvolvimento Embrionário/fisiologia , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Vertebrados/genética , Vertebrados/crescimento & desenvolvimento , Vitamina E/genética , Deficiência de Vitamina E/genética , Deficiência de Vitamina E/metabolismo , Peixe-Zebra/genética
14.
Am J Clin Nutr ; 96(4): 801-9, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22952171

RESUMO

BACKGROUND: Other than the in vitro erythrocyte hemolysis test, no valid biomarkers of vitamin E status currently exist. OBJECTIVE: We hypothesized that the urinary vitamin E metabolite α-carboxyethyl hydroxychroman (α-CEHC) could serve as a biomarker. DESIGN: The relations between urinary α-CEHC, plasma α-tocopherol, and vitamin E intakes were assessed by using a previously validated multipass, Web-based, 24-h self-administered dietary recall, and we concurrently collected plasma and 24-h urine samples from 233 participants of both sexes. RESULTS: Median vitamin E intakes were 9.7 mg α-tocopherol/d. Intakes were correlated with plasma α-tocopherol (R = 0.40, P < 0.001) and urinary α-CEHC (R = 0.42, P < 0.001); these correlations were essentially unchanged after multivariate adjustments. On the basis of multiple regression analysis, urinary α-CEHC excretion increased by ~0.086 µmol/g creatinine (95% CI: 0.047, 0.125) for every 1-mg (2.3-µmol) increase in dietary α-tocopherol. Urinary α-CEHC excretion remained at a plateau (median: 1.39 µmol/g creatinine) until dietary intakes of α-tocopherol exceeded 9 mg α-tocopherol/d. The inflection point at which vitamin E metabolism increased was estimated to be at an intake of 12.8 mg α-tocopherol/d. Daily excretion of >1.39 µmol α-CEHC/g creatinine is associated with a greater than adequate α-tocopherol status, as evidenced by increased vitamin E metabolism and excretion. CONCLUSION: Thus, urinary α-CEHC is a valid biomarker of α-tocopherol status that can be used to set a value for the Estimated Adequate Requirement of vitamin E.


Assuntos
Cromanos/urina , Estado Nutricional , alfa-Tocoferol/administração & dosagem , Adulto , Idoso , Biomarcadores/urina , Estudos de Coortes , Dieta , Suplementos Nutricionais , Feminino , Humanos , Los Angeles , Masculino , Pessoa de Meia-Idade , Necessidades Nutricionais , Valor Preditivo dos Testes , Inquéritos e Questionários , Vitamina E/administração & dosagem , Vitamina E/metabolismo , Deficiência de Vitamina E/sangue , Deficiência de Vitamina E/diagnóstico , Deficiência de Vitamina E/metabolismo , Deficiência de Vitamina E/urina , Adulto Jovem , alfa-Tocoferol/sangue , alfa-Tocoferol/metabolismo
15.
Free Radic Biol Med ; 53(4): 779-86, 2012 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-22749805

RESUMO

The haptoglobin (Hp) genotype is a major determinant of progression of nephropathy in individuals with diabetes mellitus (DM). The major function of the Hp protein is to bind and modulate the fate of extracorpuscular hemoglobin and its iron cargo. We have previously demonstrated an interaction between the Hp genotype and the DM on the accumulation of iron in renal proximal tubule cells. The primary objective of this study was to determine the intracellular localization of this iron in the proximal tubule cell and to assess its potential toxicity. Transmission electron microscopy demonstrated a marked accumulation of electron-dense deposits in the lysosomes of proximal tubules cells in Hp 2-2 DM mice. Energy-dispersive X-ray spectroscopy and electron energy loss spectroscopy were used to perform elemental analysis of these deposits and demonstrated that these deposits were iron rich. These deposits were associated with lysosomal membrane lipid peroxidation and loss of lysosomal membrane integrity. Vitamin E administration to Hp 2-2 DM mice resulted in a significant decrease in both intralysosomal iron-induced oxidation and lysosomal destabilization. Iron-induced renal tubular injury may play a major role in the development of diabetic nephropathy and may be a target for slowing the progression of renal disease.


Assuntos
Diabetes Mellitus Experimental/complicações , Nefropatias Diabéticas/genética , Haptoglobinas/genética , Túbulos Renais Proximais/patologia , Lisossomos/patologia , Animais , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/metabolismo , Nefropatias Diabéticas/tratamento farmacológico , Nefropatias Diabéticas/metabolismo , Genótipo , Membranas Intracelulares , Ferro/metabolismo , Túbulos Renais Proximais/efeitos dos fármacos , Túbulos Renais Proximais/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Lisossomos/efeitos dos fármacos , Lisossomos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Oxirredução , Estresse Oxidativo , Vitamina E/farmacologia , Vitamina E/uso terapêutico , beta-N-Acetil-Hexosaminidases/metabolismo
16.
J Biol Chem ; 287(6): 3833-41, 2012 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-22170049

RESUMO

Vitamin C (ascorbic acid, AA) is a cofactor for many important enzymatic reactions and a powerful antioxidant. AA provides protection against oxidative stress by acting as a scavenger of reactive oxygen species, either directly or indirectly by recycling of the lipid-soluble antioxidant, α-tocopherol (vitamin E). Only a few species, including humans, guinea pigs, and zebrafish, cannot synthesize AA. Using an untargeted metabolomics approach, we examined the effects of α-tocopherol and AA deficiency on the metabolic profiles of adult zebrafish. We found that AA deficiency, compared with subsequent AA repletion, led to oxidative stress (using malondialdehyde production as an index) and to major increases in the metabolites of the purine nucleotide cycle (PNC): IMP, adenylosuccinate, and AMP. The PNC acts as a temporary purine nucleotide reservoir to keep AMP levels low during times of high ATP utilization or impaired oxidative phosphorylation. The PNC promotes ATP regeneration by converting excess AMP into IMP, thereby driving forward the myokinase reaction (2ADP → AMP + ATP). On the basis of this finding, we investigated the activity of AMP deaminase, the enzyme that irreversibly deaminates AMP to form IMP. We found a 47% increase in AMP deaminase activity in the AA-deficient zebrafish, complementary to the 44-fold increase in IMP concentration. These results suggest that vitamin C is crucial for the maintenance of cellular energy metabolism.


Assuntos
Antioxidantes/farmacologia , Deficiência de Ácido Ascórbico/metabolismo , Metabolismo Energético/efeitos dos fármacos , Nucleotídeos de Purina/metabolismo , Peixe-Zebra/metabolismo , alfa-Tocoferol/farmacologia , Animais , Ácido Ascórbico/farmacologia , Cobaias , Humanos
17.
J Nutr Biochem ; 23(5): 478-86, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-21684137

RESUMO

Vitamin E (α-tocopherol) is required to prevent fetal resorption in rodents. To study α-tocopherol's role in fetal development, a nonplacental model is required. Therefore, the zebrafish, an established developmental model organism, was studied by feeding the fish a defined diet with or without added α-tocopherol. Zebrafish (age, 4-6 weeks) were fed the deficient (E-), sufficient (E+) or lab diet up to 1 years. All groups showed similar growth rates. The exponential rate of α-tocopherol depletion up to ~80 day in E- zebrafish was 0.029±0.006 nmol/g, equivalent to a depletion half-life of 25±5 days. From age ~80 days, the E- fish (5±3 nmol/g) contained ~50 times less α-tocopherol than the E+ or lab diet fish (369±131 or 362±107, respectively; P<.05). E-depleted adults demonstrated decreased startle response suggesting neurologic deficits. Expression of selected oxidative stress and apoptosis genes from livers isolated from the zebrafish fed the three diets were evaluated by quantitative polymerase chain reaction and were not found to vary with vitamin E status. When E-depleted adults were spawned, they produced viable embryos with depleted α-tocopherol concentrations. The E- embryos exhibited a higher mortality (P<.05) at 24 h post-fertillization and a higher combination of malformations and mortality (P<.05) at 120 h post-fertillization than embryos from parents fed E+ or lab diets. This study documents for the first time that vitamin E is essential for normal zebrafish embryonic development.


Assuntos
Embrião não Mamífero/anormalidades , Vitaminas/metabolismo , Peixe-Zebra/anormalidades , alfa-Tocoferol/metabolismo , Animais , Modelos Animais de Doenças , Embrião não Mamífero/metabolismo , Feminino , Vitaminas/administração & dosagem , Peixe-Zebra/metabolismo , alfa-Tocoferol/administração & dosagem
18.
J Nutr ; 141(12): 2113-8, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22013196

RESUMO

α-Tocopherol is a required, lipid-soluble antioxidant that protects PUFA. We hypothesized that α-tocopherol deficiency in zebrafish compromises PUFA status. Zebrafish were fed for 1 y either an α-tocopherol-sufficient (E+; 500 mg α-tocopherol/kg) or -deficient (E-; 1.1 mg α-tocopherol/kg) diet containing α-linolenic (ALA) and linoleic (LA) acids but without arachidonic acid (ARA), EPA, or DHA. Vitamin E deficiency in zebrafish decreased by ~20% (n-6) (P < 0.05) and (n-3) (P < 0.05) PUFA and increased the (n-6):(n-3) PUFA ratio (P < 0.05). In E- compared to E+ females, long chain-PUFA status was impaired, as assessed by a ~60% lower DHA:ALA ratio (P < 0.05) and a ~50% lower ARA:LA ratio (P < 0.05). fads2 (P < 0.05) and elovl2 (P < 0.05) mRNA expression was doubled in E- compared to E+ fish. Thus, inadequate vitamin E status led to a depletion of PUFA that may be a result of either or both increased lipid peroxidation and an impaired ability to synthesize sufficient PUFA, especially (n-3) PUFA.


Assuntos
Dieta , Ácidos Graxos Insaturados/análise , Ácidos Graxos Insaturados/metabolismo , Deficiência de Vitamina E/metabolismo , Animais , Ácido Araquidônico/administração & dosagem , Ácidos Docosa-Hexaenoicos/análise , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Ácido Linoleico/administração & dosagem , Ácido Linoleico/análise , Peroxidação de Lipídeos , Masculino , RNA/isolamento & purificação , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Peixe-Zebra , Ácido alfa-Linolênico/administração & dosagem , Ácido alfa-Linolênico/análise , alfa-Tocoferol/administração & dosagem
19.
Free Radic Biol Med ; 51(11): 2031-40, 2011 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-21945367

RESUMO

The role of hepatic xenobiotic regulatory mechanisms in modulating hepatic α-tocopherol concentrations during excess vitamin E administration remains unclear. We hypothesized that increased hepatic α-tocopherol would cause a marked xenobiotic response. Thus, we assessed cytochrome P450 oxidation systems (phase I), conjugation systems (phase II), and transporters (phase III) after daily α-tocopherol injections (100mg/kg body wt) for up to 9days in rats. α-Tocopherol injections increased hepatic α-tocopherol concentrations nearly 20-fold, along with a 10-fold increase in the hepatic α-tocopherol metabolites α-CEHC and α-CMBHC. Expression of phase I (CYP3A2, CYP3A1, CYP2B2) and phase II (SULT2A1) proteins and/or mRNAs was variably affected by α-tocopherol injections; however, expression of phase III transporter genes was consistently changed by α-tocopherol. Two liver efflux transporter genes, ABCB1b and ABCG2, were up-regulated after α-tocopherol injections, whereas OATP, a liver influx transporter, was down-regulated. Thus, an overload of hepatic α-tocopherol increases its own metabolism and increases expression of genes of transporters that are postulated to lead to increased excretion of both vitamin E and its metabolites.


Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Hepatócitos/metabolismo , alfa-Tocoferol/administração & dosagem , Animais , Hepatócitos/citologia , Hepatócitos/efeitos dos fármacos , Masculino , Ratos , Ratos Sprague-Dawley , alfa-Tocoferol/metabolismo
20.
Alcohol Clin Exp Res ; 35(3): 474-83, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21118275

RESUMO

BACKGROUND: Chronic ethanol self-administration induces oxidative stress and exacerbates lipid peroxidation. α-Tocopherol is a potent lipid antioxidant and vitamin that is dependent upon lipoprotein transport for tissue delivery. METHODS: To evaluate the extent to which vitamin E status is deranged by excessive alcohol consumption, monkeys voluntarily drinking ethanol (1.36 to 3.98 g/kg/d for 19 months, n = 11) were compared with nondrinkers (n = 5, control). RESULTS: Three alcohol-drinking animals developed hyperlipidemia with plasma triglyceride levels (1.8 ± 0.9 mM) double those of normolipidemic (NL) drinkers (0.6 ± 0.2) and controls (0.6 ± 0.3, p < 0.05); elevated plasma cholesterol (3.6 ± 0.5 mM) compared with NL drinkers (2.3 ± 0.2, p < 0.05) and controls (2.9 ± 0.3); and lower plasma α-tocopherol per triglycerides (14 ± 6 mmol/mol) than controls (27 ± 8) and NL drinkers (23 ± 6, p < 0.05). Hyperlipidemic monkey liver α-tocopherol (47 ± 15 nmol/g) was lower than NL drinkers (65 ± 13) and controls (70 ± 15, p = 0.080), as was adipose α-tocopherol (84 ± 37 nmol/g) compared with controls (224 ± 118) and NL drinkers (285 ± 234, p < 0.05). Plasma apolipoprotein (apo) CIII increased compared to baseline at both 12 and 19 months in the normolipidemic (p = 0.0016 and p = 0.0028, respectively) and in the hyperlipidemic drinkers (p < 0.05 and p < 0.05, respectively). Plasma apo H concentrations at 19 months were elevated hyperlipidemics (p < 0.05) relative to concentrations in control animals. C-reactive protein (CRP), a marker of inflammation, was increased compared to baseline at both the 12- and 19-month time points in the normolipidemic (p = 0.005 and p = 0.0153, respectively) and hyperlipidemic drinkers (p = 0.016 and p = 0.0201, respectively). CONCLUSION: A subset of alcohol-drinking monkeys showed a predisposition to alcohol-induced hyperlipidemia. The defect in lipid metabolism resulted in lower plasma α-tocopherol per triglycerides and depleted adipose tissue α-tocopherol, and thus decreased vitamin E status.


Assuntos
Consumo de Bebidas Alcoólicas/sangue , Etanol/administração & dosagem , Hiperlipidemias/sangue , Individualidade , Vitamina E/sangue , Alcoolismo/sangue , Alcoolismo/complicações , Animais , Feminino , Hiperlipidemias/etiologia , Macaca fascicularis , Autoadministração , alfa-Tocoferol/sangue
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