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1.
Lipids Health Dis ; 22(1): 103, 2023 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-37452341

RESUMO

Oxylipins are derived from enzymatic and non-enzymatic oxidation of n-3 and n-6 long-chain polyunsaturated fatty acids. They are known to be involved in inflammatory processes. The aim of this study was to describe the breast milk oxylipin profile following a docosahexaenoic acid (DHA) supplementation of mothers of preterm infants. We examined the oxylipins profile in breast milk collected at day 14 post-delivery, of 40 mothers who delivered before 29 weeks of gestation and who were supplemented with either DHA-rich algae oil (S-DHA) or a placebo (PL). These mothers were selected from the MOBYDIck cohort (NCT02371460 registered on 25/05/2015 in ClinicalTrials.gov) according to the supplementation received (S-DHA vs. PL) and the DHA content quartiles as measured in breast milk (Low vs. High) to generate four study groups. Milk oxylipins, as ng/mL of milk, were analyzed by LC-MS/MS. Ten oxylipins derived from DHA were higher in the S-DHA-High group than the other three groups (P < 0.001). The 18-HEPE, was also higher in the S-DHA-High group (0.11 ± 0.01) compared to the other groups (P = 0.0001). Compared to the PL-Low group, there was a reduction in pro-inflammatory prostaglandins found in the S-DHA-High group with lower levels of prostaglandins PGF2α (0.21 ± 0.45 in the S-DHA-High group vs. 1.87 ± 0.44 in the PL-Low group, P = 0.03) and of PGE2 (0.33 ± 0.26 in the S-DHA-High group vs. 1.28 ± 0.25 in the PL-Low group, P = 0.04).In sum, the DHA supplementation was linked with a predominance of anti-inflammatory oxylipins in breast milk of mothers who delivered very preterm, like 17(S)-HDHA and 18-HEPE, precursors of D and E resolvins respectively. This was also accompanied with a lower level of pro-inflammatory prostaglandins.


Assuntos
Ácidos Docosa-Hexaenoicos , Leite Humano , Lactente , Feminino , Recém-Nascido , Humanos , Oxilipinas , Recém-Nascido Prematuro , Mães , Cromatografia Líquida , Espectrometria de Massas em Tandem , Suplementos Nutricionais , Ácidos Graxos , Prostaglandinas
2.
Mar Drugs ; 20(3)2022 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-35323474

RESUMO

The objective of the present study was to test whether a brown seaweed extract rich in polyphenols combined with a low-calorie diet would induce additional weight loss and improve blood glucose homeostasis in association with a metabolic and inflammatory response in overweight/obese prediabetic subjects. Fifty-six overweight/obese, dysglycemic, and insulin-resistant men and women completed a randomized, placebo-controlled, double-blind, and parallel clinical trial. Subjects were administrated 500 mg/d of either brown seaweed extract or placebo combined with individualized nutritional advice for moderate weight loss over a period of 12 weeks. Glycemic, anthropometric, blood pressure, heart rate, body composition, lipid profile, gut integrity, and oxidative and inflammatory markers were measured before and at the end of the trial. No effect was observed on blood glucose. We observed significant but small decreases in plasma C-peptide at 120 min during 2 h-OGTT (3218 ± 181 at pre-intervention vs. 2865 ± 186 pmol/L at post-intervention in the brown seaweed group; 3004 ± 199 at pre-intervention vs. 2954 ± 179 pmol/L at post-intervention in the placebo group; changes between the two groups, p = 0.002), heart rate (72 ± 10 at pre-intervention vs. 69 ± 9 (n/min) at post-intervention in the brown seaweed group; 68 ± 9 at pre-intervention vs. 68 ± 8 (n/min) at post-intervention in the placebo group; changes between the two groups, p = 0.01), and an inhibition in the increase of pro-inflammatory interleukin-6 (IL-6) (1.3 ± 0.7 at pre-intervention vs. 1.5 ± 0.7 pg/L at post-intervention in the brown seaweed group; 1.4 ± 1.1 at pre-intervention vs. 2.2 ± 1.6 pg/L at post-intervention in the placebo group; changes between the two groups, p = 0.02) following brown seaweed consumption compared with placebo in the context of moderate weight loss. Although consumption of brown seaweed extract had no effect on body weight or blood glucose, an early attenuation of the inflammatory response was observed in association with marginal changes in metabolic parameters related to the prevention of diabetes type 2.


Assuntos
Anti-Inflamatórios/uso terapêutico , Ascophyllum/química , Misturas Complexas/uso terapêutico , Fucus/química , Sobrepeso/tratamento farmacológico , Polifenóis/uso terapêutico , Estado Pré-Diabético/tratamento farmacológico , Alga Marinha/química , Adolescente , Adulto , Idoso , Glicemia/efeitos dos fármacos , Peptídeo C/sangue , Dieta com Restrição de Gorduras , Método Duplo-Cego , Feminino , Humanos , Insulina/sangue , Interleucina-6/sangue , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade , Sobrepeso/sangue , Estado Pré-Diabético/sangue , Resultado do Tratamento , Redução de Peso/efeitos dos fármacos , Adulto Jovem
3.
Sci Rep ; 11(1): 21492, 2021 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-34728723

RESUMO

Preterm infants are deficient in long-chain polyunsaturated fatty acids, especially docosahexaenoic acid (DHA), a fatty acid (FA) associated with an increase in bronchopulmonary dysplasia (BPD). In two previous randomized control trials, DHA supplementation did not reduce the risk of BPD. We examined the breast milk FA profile, collected 14 days after birth, of mothers who delivered before 29 weeks of gestation and who were supplemented with DHA-rich algae oil or a placebo within 72 h after birth as part of the MOBYDIck trial. Milk FA were analyzed by gas chromatography. The total amount of FA (mg/mL) was similar in both groups but the supplementation increased DHA (expressed as % of total FA, mean ± SD, treatment vs placebo, 0.95 ± 0.44% vs 0.34 ± 0.20%; P < 0.0001), n-6 docosapentaenoic acid (DPA) (0.275 ± 0.14% vs 0.04 ± 0.04%; P < 0.0001) and eicosapentaenoic acid (0.08 ± 0.08% vs 0.07 ± 0.07%; P < 0.0001) while decreasing n-3 DPA (0.16 ± 0.05% vs 0.17 ± 0.06%; P < 0.05). Supplementation changed the ratio of DHA to arachidonic acid (1.76 ± 1.55% vs 0.60 ± 0.31%; P < 0.0001) and n-6 to n-3 FA (0.21 ± 0.06% vs 0.17 ± 0.04%; P < 0.0001). DHA-rich algae supplementation successfully increased the DHA content of breast milk but also included secondary changes that are closely involved with inflammation and may contribute to changing clinical outcomes.


Assuntos
Suplementos Nutricionais , Ácidos Docosa-Hexaenoicos/administração & dosagem , Ácidos Graxos/análise , Leite Humano/metabolismo , Óleos de Plantas/administração & dosagem , Adulto , Clorófitas/química , Feminino , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Leite Humano/efeitos dos fármacos , Mães
4.
Nat Commun ; 12(1): 6264, 2021 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-34716330

RESUMO

Lack of dystrophin causes muscle degeneration, which is exacerbated by chronic inflammation and reduced regenerative capacity of muscle stem cells in Duchenne Muscular Dystrophy (DMD). To date, glucocorticoids remain the gold standard for the treatment of DMD. These drugs are able to slow down the progression of the disease and increase lifespan by dampening the chronic and excessive inflammatory process; however, they also have numerous harmful side effects that hamper their therapeutic potential. Here, we investigated Resolvin-D2 as a new therapeutic alternative having the potential to target multiple key features contributing to the disease progression. Our in vitro findings showed that Resolvin-D2 promotes the switch of macrophages toward their anti-inflammatory phenotype and increases their secretion of pro-myogenic factors. Moreover, Resolvin-D2 directly targets myogenic cells and promotes their differentiation and the expansion of the pool of myogenic progenitor cells leading to increased myogenesis. These effects are ablated when the receptor Gpr18 is knocked-out, knocked-down, or blocked by the pharmacological antagonist O-1918. Using different mouse models of DMD, we showed that Resolvin-D2 targets both inflammation and myogenesis leading to enhanced muscle function compared to glucocorticoids. Overall, this preclinical study has identified a new therapeutic approach that is more potent than the gold-standard treatment for DMD.


Assuntos
Ácidos Docosa-Hexaenoicos/farmacologia , Desenvolvimento Muscular/efeitos dos fármacos , Distrofia Muscular de Duchenne/tratamento farmacológico , Distrofia Muscular de Duchenne/fisiopatologia , Animais , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/fisiologia , Células Cultivadas , Modelos Animais de Doenças , Glucocorticoides/farmacologia , Macrófagos/efeitos dos fármacos , Macrófagos/patologia , Masculino , Camundongos Endogâmicos mdx , Camundongos Knockout , Contração Muscular/efeitos dos fármacos , Contração Muscular/fisiologia , Desenvolvimento Muscular/fisiologia , Mioblastos/efeitos dos fármacos , Utrofina/genética
5.
Pregnancy Hypertens ; 25: 213-218, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34265569

RESUMO

OBJECTIVE: Examine the levels of plasma antioxidant vitamins before and during a treatment with placebo or vitamin E + C supplement to prevent preeclampsia (PE). STUDY DESIGN: Per-protocol analysis of a subset group of pregnant women (n = 295) from the International Trial of Antioxidants for the Prevention of PE (INTAPP) randomized case-control study. Normotensive receiving placebo or vitamins (n = 115 and 87 respectively) were compared to gestational hypertension (GH) without proteinuria (n = 30 and 27) and PE (n = 21 and 15). Vitamin quantification was performed at 12-18, 24-26 and 32-34 weeks of gestation. MAIN OUTCOME MEASURES: Coenzyme (Co) Q10, ß-carotene and vitamins E (α and γ forms) plasma levels. RESULTS: Vitamin E + C supplementation was found to increase the α-tocopherol levels by 40% but was associated with a 57% decrease in the γ-tocopherol isoform for all study groups (p < 0.001). The ß -carotene was lower in the PE than in the normotensive and GH groups (p < 0.001) while the level of CoQ10 remained unaffected. CONCLUSIONS: A more personalized approach that target the suboptimal levels of specific antioxidants without disturbing the α/γ-tocopherol ratio could be a more successful approach to counteract oxidative stress in PE.


Assuntos
Antioxidantes/administração & dosagem , Pré-Eclâmpsia/diagnóstico , Diagnóstico Pré-Natal , Vitaminas/administração & dosagem , Adulto , Estudos de Coortes , Suplementos Nutricionais , Feminino , Humanos , Pré-Eclâmpsia/sangue , Gravidez , Sensibilidade e Especificidade , Resultado do Tratamento , Vitaminas/sangue , alfa-Tocoferol/sangue , beta Caroteno/sangue
6.
Artigo em Inglês | MEDLINE | ID: mdl-33276284

RESUMO

INTRODUCTION: Cancer has been associated with increased oxidative stress and deregulation of bioactive oxylipins derived from long-chain polyunsaturated fatty acids (LC-PUFA) like arachidonic acid (AA). There is a debate whether ω-3 LC-PUFA could promote or prevent prostate tumor growth through immune modulation and reduction of oxidative stress. Our aim was to study the association between enzymatically or non-enzymatically produced oxidized-LC-PUFA metabolites and tumor growth in an immune-competent eugonadal and castrated C57BL/6 male mice injected with TRAMP-C2 prostate tumor cells, fed with ω-3 or ω-6 LC-PUFA-rich diets. MATERIALS AND METHODS: Tumor fatty acids were profiled by gas chromatography and 26 metabolites derived from either AA, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were assessed by liquid chromatography-mass spectrometry. RESULTS: The enriched ω-3 diet did not reduce oxidative stress overall in tumors but favored the formation of ω-3 rather than ω-6 derived isoprostanoids. We discovered that EPA and its oxidized-derivatives like F3-isoprostanes and prostaglandin (PG)F3α, were inversely correlated with tumor volume (spearman correlations and T-test, p<0.05). In contrast, F2-isoprostanes, adrenic acid, docosapentaenoic acid (DPAω-6) and PGE2 were positively correlated with tumor volume. Interestingly, F4-neuroprostanes, PGD2, PGF2α, and thromboxane were specifically increased in TRAMP-C2 tumors of castrated mice compared to those of eugonadal mice. DISCUSSION: Decreasing tumor growth under ω-3 diet could be attributed in part to increased levels of EPA and its oxidized-derivatives, a reduced level of pro-angiogenic PGE2 and increased levels of F4-neuroprostanes and resolvins content in tumors, suspected of having anti-proliferative and anti-inflammatory effects.


Assuntos
Anti-Inflamatórios , Proliferação de Células/efeitos dos fármacos , Dinoprostona/metabolismo , Ácidos Graxos Ômega-3 , Neoplasias da Próstata , Animais , Anti-Inflamatórios/farmacocinética , Anti-Inflamatórios/farmacologia , Linhagem Celular Tumoral , Ácidos Graxos Ômega-3/farmacocinética , Ácidos Graxos Ômega-3/farmacologia , Masculino , Camundongos , Oxirredução , Neoplasias da Próstata/dietoterapia , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia
7.
Artigo em Inglês | MEDLINE | ID: mdl-29031397

RESUMO

This study aimed to determine whether dairy macronutrients alter markers of inflammation and oxidative stress in endothelial cells. Human endothelial cells (HUVEC) were treated with ruminant trans fatty acids (rTFA), either trans-vaccenic acid (tVA) or trans-palmitoleic acid (tPA), whey protein hydrolysate, leucine or combinations of rTFA and dairy protein compounds. Industrial TFA elaidic acid (EA) was also investigated and compared with rTFA. Inflammatory prostaglandins (PG) and F2-isoprostanes (F2-isoP) isomers, markers of oxidative stress, were assessed in cell supernatants by LC-MS/MS. Both tVA and tPA, as well as whey protein hydrolysate, decreased TNFα-induced PG excretion. Combinations of rTFA and dairy protein compounds decreased inflammation to a similar extent than rTFA alone. EA increased class VI F2-isoP isomers, whereas tVA mostly raised class III isomers. In summary, rTFA decreased inflammatory markers and increased oxidative stress markers in endothelial cells. Combinations of rTFA with whey proteins or leucine showed no additive effect.


Assuntos
Células Endoteliais/efeitos dos fármacos , Inflamação/tratamento farmacológico , Ácidos Oleicos/administração & dosagem , Estresse Oxidativo/efeitos dos fármacos , Animais , Biomarcadores/metabolismo , Células Endoteliais/metabolismo , F2-Isoprostanos/genética , F2-Isoprostanos/metabolismo , Células Endoteliais da Veia Umbilical Humana , Humanos , Inflamação/metabolismo , Inflamação/patologia , Prostaglandinas/genética , Prostaglandinas/metabolismo , Fatores de Risco , Ruminantes/metabolismo , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo
8.
Lipids ; 52(4): 315-325, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28315997

RESUMO

Trans fatty acids (TFA) intake has been linked to cardiovascular diseases and liver diseases; yet the effect of TFA on inflammation remains controversial. Accordingly, the objective of this paper was to determine the in vitro effects of TFA on inflammatory gene expression. Human umbilical vein endothelial cells (HUVEC) and human hepatocellular carcinoma (HepG2) cells were treated for 24 h with either trans-vaccenic acid (tVA), trans-palmitoleic acid (tPA) or elaidic acid (EA) at concentrations of 5-150 µM, or with a mixture of tVA and tPA (150/50 µM). All TFA were highly incorporated into cell membranes, as determined by gas chromatography, representing 15-20% of total fatty acids in HUVEC and 3-8% in HepG2 cells. Incorporation of EA, a common industrial TFA, increased the ratio of the stearoyl-CoA desaturase (SCD-1), a key enzyme involved in fatty acid metabolism. Ruminant TFA, including tVA, tPA and the mixture of tVA and tPA, significantly reduced the TNF-α-induced gene expression of TNF, VCAM-1 and SOD2 in HUVEC, as well as TNF and IL-8 in HepG2 cells. EA also decreased inflammatory gene expression in HUVEC, but not in HepG2 cells. The inhibition of peroxisome proliferator-activated receptor (PPAR)-γ did not influence the effects of TFA on gene expression. Overall, physiological and supraphysiological concentrations of TFA, especially tVA and tPA, prevented inflammatory gene expression in vitro. This effect is independent of PPAR-γ activation and may be due to an alteration of fatty acid metabolism in cell membranes caused by the high incorporation of TFA.


Assuntos
Anti-Inflamatórios/farmacologia , Carcinoma Hepatocelular/imunologia , Interleucina-8/genética , Neoplasias Hepáticas/imunologia , Fator de Necrose Tumoral alfa/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Células Hep G2 , Células Endoteliais da Veia Umbilical Humana , Humanos , Metabolismo dos Lipídeos/efeitos dos fármacos , Estearoil-CoA Dessaturase/genética , Ácidos Graxos trans , Fator de Necrose Tumoral alfa/genética
9.
Acta Obstet Gynecol Scand ; 89(3): 360-6, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20199352

RESUMO

OBJECTIVE: Alteration of cytokines level and oxidative stress are both associated with preeclampsia (PE). We have investigated if IL-6 and IL-18 levels were related to coenzyme Q(10) (CoQ(10)), an antioxidant and a marker of oxidative stress in the plasma from normotensive and preeclamptic pregnancies. DESIGN: IL-6 and IL-18 levels were determined by enzyme-linked immunosorbent assays in plasmas from preeclamptic (n = 29) and normotensive pregnancies (n = 30). The concentrations of CoQ(10) in the different redox forms were measured in plasma using liquid chromatography coupled to electrochemical detection. Data were analyzed using the Wilcoxon Rank-Sum test and correlations were obtained by the Spearman's Rho test. MAIN OUTCOME MEASURES: IL-6 concentrations were 2.8-fold higher in preeclamptic plasmas than in controls (p = 0.0006), and IL-18 concentrations were found significantly lower in preeclamptic samples than in controls (p = 0.007). No correlation was found between IL-18 or IL-6 and antioxidant vitamin CoQ(10) in plasmas from normotensive pregnant women. However, in PE, IL-18 level was positively correlated with the reduced form of CoQ(10) (r = 0.3680, p = 0.0495). CONCLUSION: This is the first demonstration that IL-18 is potentially linked to oxidative stress in PE, since its level correlates with the concentration of the powerful antioxidant CoQ(10). These results also associate the immune system with the oxidant/antioxidant imbalance observed in PE.


Assuntos
Interleucina-18/sangue , Pré-Eclâmpsia/sangue , Ubiquinona/sangue , Adulto , Cromatografia Líquida , Ensaio de Imunoadsorção Enzimática , Feminino , Idade Gestacional , Humanos , Interleucina-6/sangue , Estresse Oxidativo , Gravidez , Estatísticas não Paramétricas
10.
Endocrinology ; 147(12): 5600-10, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16935840

RESUMO

Nitric oxide (NO) is a free radical produced by the action of NO synthases (NOS) and is known to be involved in the regulation of many reproductive events that occur in the oviducts. The oviducts are highly specialized organs that play crucial roles in reproduction by providing an optimal environment for the final maturation of gametes, fertilization, and early embryo development. In this study, we analyzed the expression, hormonal regulation, and cellular distribution of neuronal, inducible, and endothelial NOS in different bovine oviduct segments to better understand the roles played by these enzymes in oviductal functions in vivo. Quantitative RT-PCR analysis revealed that NOS isoforms are hormonally regulated and differentially expressed along the oviduct throughout the estrous cycle. All NOS were highly expressed around the time of estrus, and immunohistochemistry studies determined that neuronal NOS, inducible NOS (iNOS), and endothelial NOS are differentially distributed in cells along the oviduct. Interestingly, our results showed that estradiol selectively up-regulates iNOS expression in the oviduct during the periovulatory period corresponding to the window of ovulation, oocyte transport, and fertilization. The resulting NO production by this high-output NOS may be of crucial importance for reproductive events that occur in the oviduct. This study provided the first demonstration that NO production is hormonally regulated in the mammalian oviducts in vivo. Our results suggest that neuronal NOS, iNOS, and endothelial NOS contribute to oviductal functions in a timely and site-specific manner.


Assuntos
Tubas Uterinas/metabolismo , Regulação da Expressão Gênica , Óxido Nítrico Sintase/metabolismo , Animais , Bovinos , Estradiol/farmacologia , Ciclo Estral/efeitos dos fármacos , Ciclo Estral/metabolismo , Tubas Uterinas/anatomia & histologia , Tubas Uterinas/efeitos dos fármacos , Feminino , Óxido Nítrico Sintase Tipo I/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Isoformas de Proteínas/metabolismo , Distribuição Tecidual
11.
Endocrinology ; 146(6): 2583-92, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15746255

RESUMO

The oviduct plays a crucial role in mammalian reproduction by providing an optimal environment for the final maturation and transport of gametes, fertilization, and early embryonic development. It is now recognized that these reproductive events in vitro can be either negatively or positively affected by reactive oxygen species such as hydrogen peroxide and lipid hydroperoxides. In the current study, we analyzed the expression of the phospholipid hydroperoxide glutathione peroxidase (PHGPx or GPx-4), a selenoenzyme that directly reduces membrane-bound lipid hydroperoxides in the bovine oviduct. Using in situ hybridization, we demonstrated that GPx-4 expression is almost restricted to the oviductal luminal epithelium in contrast to GPx-1, which is widely distributed, and GPx-2 and -3, which are mainly detected in the epithelial cells and lamina propria. Interestingly, real-time quantitative RT-PCR analysis showed that GPx-4 expression was highest during the follicular and postovulatory phases. In addition, GPx-4 expression was highest in the isthmus proximal to the dominant follicle during the follicular stage and remained high during the postovulatory period. This increased in expression of GPx-4 corresponded to increased GPx-4 enzymatic activity. Based on intrauterine infusion of estradiol, we determined that the increase in expression and activity of GPx-4 is estrogen mediated. This work clearly demonstrates that GPx-4 gene expression is influenced by the proximity of the dominant follicle in the oviduct in vivo. We propose that GPx-4 has an important role in the physiological control of peroxide tone in the bordering cells of the oviductal lumen.


Assuntos
Estrogênios/fisiologia , Ciclo Estral/fisiologia , Glutationa Peroxidase/genética , Oviductos/enzimologia , Animais , Bovinos , Estradiol/farmacologia , Feminino , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Regulação Enzimológica da Expressão Gênica/fisiologia , Glutationa Peroxidase/metabolismo , Técnicas In Vitro , Oviductos/efeitos dos fármacos , Fosfolipídeo Hidroperóxido Glutationa Peroxidase , RNA Mensageiro/análise , Regulação para Cima/fisiologia , Glutationa Peroxidase GPX1
12.
Free Radic Biol Med ; 33(9): 1279-89, 2002 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-12398936

RESUMO

We previously reported that hyperoxia (95% O(2)) induces an S-phase cell cycle arrest in glutathione peroxidase-deficient human carcinoma cells T47D-H3 (Exp. Cell Res. 256:347-357; 2000). Here, we investigated whether increasing the peroxide scavenging capacity via glutathione peroxidase-1 (GPx1) expression can prevent cell cycle alterations induced by oxidative stress. We show that GPx1-proficient T47D-GPx-2 transfectant cells, in which GPx1 concentration is most elevated in mitochondria (Biochem. Biophys. Res. Commun. 272:416-422; 2000), are partially resistant to cell cycle inhibition induced by hyperoxia or menadione exposure. Transient cell growth resistance was observed at the level of cell cycle phase distribution, Cdk2 activity, and DNA synthesis after 40 h hyperoxia. This differential resistance was associated with an inhibition of ROS production and lipid peroxidation induced by hyperoxia. After 64 h hyperoxic exposure, cell growth was completely abolished in both cell lines, despite elevated glutathione levels. However, in contrast to the GPx1-deficient cells, T47D-GPx-2 cells showed an increased capacity to recover from a cell cycle arrest mediated by a 64 h hyperoxic stress. Differential recovery was also observed at the ultrastructural level between Gpx1-proficient and -deficient cells. These data indicate that GPx1 played an important role in the cell capacity to recover from hyperoxic insults. The limited protection conferred by GPx1 during hyperoxia suggests that the deleterious effects were partially mediated by peroxide-derived free radicals, but also involved the action of nonperoxide-derived reactive species.


Assuntos
Neoplasias da Mama/enzimologia , Neoplasias da Mama/patologia , Quinases relacionadas a CDC2 e CDC28 , Ciclo Celular/fisiologia , Glutationa Peroxidase/metabolismo , Hiperóxia/enzimologia , Northern Blotting , Divisão Celular , Quinase 2 Dependente de Ciclina , Quinases Ciclina-Dependentes/metabolismo , Citometria de Fluxo , Radicais Livres/metabolismo , Humanos , Peroxidação de Lipídeos/efeitos dos fármacos , Mitocôndrias/metabolismo , Estresse Oxidativo , Proteínas Serina-Treonina Quinases/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transfecção , Células Tumorais Cultivadas , Glutationa Peroxidase GPX1
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