Katie Lebold, MD PhD
Resident in Emergency Medicine
All Publications
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Inflammatory mechanisms linking maternal and childhood asthma.
Journal of leukocyte biology
2020; 108 (1): 113-121
Abstract
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.
View details for DOI 10.1002/JLB.3MR1219-338R
View details for PubMedID 32040236
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Optogenetic Control of Airway Cholinergic Neurons In Vivo.
American journal of respiratory cell and molecular biology
2020; 62 (4): 423-429
Abstract
Dysregulation of airway nerves leads to airway hyperreactivity, a hallmark of asthma. Although changes to nerve density and phenotype have been described in asthma, the relevance of these changes to nerve function has not been investigated due to anatomical limitations where afferent and efferent nerves run in the same nerve trunk, making it difficult to assess their independent contributions. We developed a unique and accessible system to activate specific airway nerves to investigate their function in mouse models of airway disease. We describe a method to specifically activate cholinergic neurons using light, resulting in immediate, measurable increases in airway inflation pressure and decreases in heart rate. Expression of light-activated channelrhodopsin 2 in these neurons is governed by Cre expression under the endogenous choline acetyltransferase promoter, and we describe a method to decrease variability in channelrhodopsin expression in future experiments. Optogenetic activation of specific subsets of airway neurons will be useful for studying the functional relevance of other observed changes, such as changes to nerve morphology and protein expression, across many airway diseases, and may be used to study the function of subpopulations of autonomic neurons in lungs and other organs.
View details for DOI 10.1165/rcmb.2019-0378MA
View details for PubMedID 31899655
View details for PubMedCentralID PMC7110977
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IL-5 Exposure In Utero Increases Lung Nerve Density and Airway Reactivity in Adult Offspring.
American journal of respiratory cell and molecular biology
2020; 62 (4): 493-502
Abstract
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.
View details for DOI 10.1165/rcmb.2019-0214OC
View details for PubMedID 31821769
View details for PubMedCentralID PMC7110978
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Eosinophils increase airway sensory nerve density in mice and in human asthma
SCIENCE TRANSLATIONAL MEDICINE
2018; 10 (457)
Abstract
In asthma, airway nerve dysfunction leads to excessive bronchoconstriction and cough. It is well established that eosinophils alter nerve function and that airway eosinophilia is present in 50 to 60% of asthmatics. However, the effects of eosinophils on airway nerve structure have not been established. We tested whether eosinophils alter airway nerve structure and measured the physiological consequences of those changes. Our results in humans with and without eosinophilic asthma showed that airway innervation and substance P expression were increased in moderate persistent asthmatics compared to mild intermittent asthmatics and healthy subjects. Increased innervation was associated with a lack of bronchodilator responsiveness and increased irritant sensitivity. In a mouse model of eosinophilic airway inflammation, the increase in nerve density and airway hyperresponsiveness were mediated by eosinophils. Our results implicate airway nerve remodeling as a key mechanism for increased irritant sensitivity and exaggerated airway responsiveness in eosinophilic asthma.
View details for PubMedID 30185653
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Eosinophil and airway nerve interactions in asthma.
Journal of leukocyte biology
2018; 104 (1): 61-67
Abstract
Airway eosinophils are increased in asthma and are especially abundant around airway nerves. Nerves control bronchoconstiction and in asthma, airway hyperreactivity (where airways contract excessively to inhaled stimuli) develops when eosinophils alter both parasympathetic and sensory nerve function. Eosinophils release major basic protein, which is an antagonist of inhibitory M2 muscarinic receptors on parasympathetic nerves. Loss of M2 receptor inhibition potentiates parasympathetic nerve-mediated bronchoconstriction. Eosinophils also increase sensory nerve responsiveness by lowering neurons' activation threshold, stimulating nerve growth, and altering neuropeptide expression. Since sensory nerves activate parasympathetic nerves via a central neuronal reflex, eosinophils' effects on both sensory and parasympathetic nerves potentiate bronchoconstriction. This review explores recent insights into mechanisms and effects of eosinophil and airway nerve interactions in asthma.
View details for DOI 10.1002/JLB.3MR1117-426R
View details for PubMedID 29633324
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Toll-Like Receptor 7-Targeted Therapy in Respiratory Disease.
Transfusion medicine and hemotherapy : offizielles Organ der Deutschen Gesellschaft fur Transfusionsmedizin und Immunhamatologie
2016; 43 (2): 114-9
Abstract
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.
View details for DOI 10.1159/000445324
View details for PubMedID 27226793
View details for PubMedCentralID PMC4872053
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The influences of parental diet and vitamin E intake on the embryonic zebrafish transcriptome
COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS
2014; 10: 22–29
Abstract
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.
View details for DOI 10.1016/j.cbd.2014.02.001
View details for Web of Science ID 000337931800003
View details for PubMedID 24657723
View details for PubMedCentralID PMC4037372
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Interactions between alpha-tocopherol, polyunsaturated fatty acids, and lipoxygenases during embryogenesis
FREE RADICAL BIOLOGY AND MEDICINE
2014; 66: 13–19
Abstract
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.
View details for DOI 10.1016/j.freeradbiomed.2013.07.039
View details for Web of Science ID 000329562900003
View details for PubMedID 23920314
View details for PubMedCentralID PMC3874081
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Novel liquid chromatography-mass spectrometry method shows that vitamin E deficiency depletes arachidonic and docosahexaenoic acids in zebrafish (Danio rerio) embryos
REDOX BIOLOGY
2014; 2: 105–13
Abstract
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.
View details for DOI 10.1016/j.redox.2013.12.007
View details for Web of Science ID 000350769600015
View details for PubMedID 24416717
View details for PubMedCentralID PMC3887274
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Chronic vitamin E deficiency promotes vitamin C deficiency in zebrafish leading to degenerative myopathy and impaired swimming behavior
COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY C-TOXICOLOGY & PHARMACOLOGY
2013; 157 (4): 382–89
Abstract
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.
View details for DOI 10.1016/j.cbpc.2013.03.007
View details for Web of Science ID 000319484600008
View details for PubMedID 23570751
View details for PubMedCentralID PMC3653440
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The alpha-Tocopherol Transfer Protein Is Essential for Vertebrate Embryogenesis
PLOS ONE
2012; 7 (10): e47402
Abstract
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.
View details for DOI 10.1371/journal.pone.0047402
View details for Web of Science ID 000309995100106
View details for PubMedID 23077608
View details for PubMedCentralID PMC3471827
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Urinary alpha-carboxyethyl hydroxychroman can be used as a predictor of alpha-tocopherol adequacy, as demonstrated in the Energetics Study
AMERICAN JOURNAL OF CLINICAL NUTRITION
2012; 96 (4): 801–9
Abstract
Other than the in vitro erythrocyte hemolysis test, no valid biomarkers of vitamin E status currently exist.We hypothesized that the urinary vitamin E metabolite α-carboxyethyl hydroxychroman (α-CEHC) could serve as a biomarker.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.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.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.
View details for DOI 10.3945/ajcn.112.038620
View details for Web of Science ID 000308977000014
View details for PubMedID 22952171
View details for PubMedCentralID PMC3441108
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Poor lysosomal membrane integrity in proximal tubule cells of haptoglobin 2-2 genotype mice with diabetes mellitus
FREE RADICAL BIOLOGY AND MEDICINE
2012; 53 (4): 779–86
Abstract
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.
View details for DOI 10.1016/j.freeradbiomed.2012.06.015
View details for Web of Science ID 000307920100014
View details for PubMedID 22749805
View details for PubMedCentralID PMC3600120
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Zebrafish (Danio rerio) fed vitamin E-deficient diets produce embryos with increased morphologic abnormalities and mortality
JOURNAL OF NUTRITIONAL BIOCHEMISTRY
2012; 23 (5): 478–86
Abstract
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.
View details for DOI 10.1016/j.jnutbio.2011.02.002
View details for Web of Science ID 000303640900009
View details for PubMedID 21684137
View details for PubMedCentralID PMC3179832
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Vitamin C Deficiency Activates the Purine Nucleotide Cycle in Zebrafish
JOURNAL OF BIOLOGICAL CHEMISTRY
2012; 287 (6): 3833–41
Abstract
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.
View details for DOI 10.1074/jbc.M111.316018
View details for Web of Science ID 000300410900020
View details for PubMedID 22170049
View details for PubMedCentralID PMC3281694
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Tocol-omic' Diversity in Wild Barley, Short Communication
CHEMISTRY & BIODIVERSITY
2011; 8 (12): 2322–30
Abstract
Hordeum spontaneum, wild barley, is the direct progenitor of domestic barley, Hordeum vulgare, an economically important ingredient of animal feed, beer, soy sauce, and more recently, of nutraceuticals. Domestic barley has also been used in the past as a medicine. Barley is a rich source of tocotrienols, with α-tocotrienol being the most prevalent. Wild barley seeds were harvested from ecogeographically diverse areas across the Fertile Crescent, and the tocopherol (α-δ) and tocotrienol (α-δ) contents were determined. Diversity differences in individual and total 'tocol' values were significant between and within specific countries, and were significantly correlated with temperature. Wild barley may be used in the future to improve functional qualities of domestic barley. 'Tocolome' and 'tocolomics' are proposed to encompass all tocols and potentially synergy-enhancing 'entourage' compounds that may occur in tocols' 'metabolomic neighborhoods', aiding the standardized manufacture of complex barley derivatives for nutraceutical and pharmaceutical functions.
View details for DOI 10.1002/cbdv.201000363
View details for Web of Science ID 000297791000015
View details for PubMedID 22162170
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alpha-Tocopherol injections in rats up-regulate hepatic ABC transporters, but not cytochrome P450 enzymes
FREE RADICAL BIOLOGY AND MEDICINE
2011; 51 (11): 2031–40
Abstract
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.
View details for DOI 10.1016/j.freeradbiomed.2011.08.033
View details for Web of Science ID 000297036500009
View details for PubMedID 21945367
View details for PubMedCentralID PMC3208783
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Vitamin E Deficiency Decreases Long-Chain PUFA in Zebrafish (Danio rerio)
JOURNAL OF NUTRITION
2011; 141 (12): 2113–18
Abstract
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.
View details for DOI 10.3945/jn.111.144279
View details for Web of Science ID 000297387200003
View details for PubMedID 22013196
View details for PubMedCentralID PMC3223870
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Validity of Urinary Metabolites alpha-CEHC and alpha-CMBHC as Biomarkers of alpha-Tocopherol Consumption: Correlations with Dietary and Plasma alpha Tocopherol
FEDERATION AMER SOC EXP BIOL. 2011
View details for Web of Science ID 000310708407162
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The role of the alpha-tocopherol transfer protein during zebrafish embryogenesis
FEDERATION AMER SOC EXP BIOL. 2011
View details for Web of Science ID 000310708406588
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Impact of Vitamin E Deficiency and Gender Differences on Fatty Acid Metabolism in Zebrafish
FEDERATION AMER SOC EXP BIOL. 2011
View details for Web of Science ID 000310708407161
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Individual Differences in Hyperlipidemia and Vitamin E Status in Response to Chronic Alcohol Self-Administration in Cynomolgus Monkeys
ALCOHOLISM-CLINICAL AND EXPERIMENTAL RESEARCH
2011; 35 (3): 474–83
Abstract
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.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).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).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.
View details for DOI 10.1111/j.1530-0277.2010.01364.x
View details for Web of Science ID 000288143100011
View details for PubMedID 21118275
View details for PubMedCentralID PMC3116096
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Zebrafish as a model to determine the mechanisms of vitamin E function
FEDERATION AMER SOC EXP BIOL. 2010
View details for Web of Science ID 000208675503548
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Effects of short-term tocopherol (T) feeding on nitric oxide production and protein nitration following endotoxin (LPS) challenge in beef calves
ELSEVIER SCIENCE INC. 2010: 590
View details for Web of Science ID 000295056202293
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Vitamin E and C supplementation does not ameliorate muscle dysfunction after anterior cruciate ligament surgery
FREE RADICAL BIOLOGY AND MEDICINE
2009; 47 (11): 1611–18
Abstract
Muscle atrophy and weakness are predominant impairments after anterior cruciate ligament (ACL) surgical repair. We tested the hypothesis that vitamin E and C supplementation will improve recovery from ACL injury. Men undergoing elective ACL surgery were randomly assigned to twice-daily supplements of either antioxidants (AO; vitamins E and C, n=10) or matching placebos (n=10) from 2 weeks before until 3 months after surgery. Each subject provided several fasting blood draws, two muscle biopsies from the thigh muscle of the injured limb, and strength and thigh circumference measurements of the lower limbs. Muscle atrophy was apparent in both groups before and several days after surgery. Compared with baseline measurements, peak isometric force of the injured limb increased significantly (P<0.05) by 3 months postsurgery in both treatment groups; however, AO supplementation did not augment these strength gains. By contrast, baseline plasma ascorbic acid concentrations correlated (r=0.59, P=0.006) with subsequent improvement in the strength of the injured limb. In summary, vitamin E and C supplementation was ineffective in potentiating the improvement in force production by the injured limb; however, baseline vitamin C status was associated with beneficial outcomes in strength, suggesting that long-term dietary habits are more effective than short-term supplements.
View details for DOI 10.1016/j.freeradbiomed.2009.09.010
View details for Web of Science ID 000271934300011
View details for PubMedID 19751822