RESUMO
BACKGROUND/AIMS: NADPH (nicotinamide adenine dinucleotide phosphate) oxidase (NOX)-mediated oxidative stress plays a key role in promotion of oxidative injury in the cardiovascular system. The aim of this study is to evaluate the status of NOX in endothelial progenitor cells (EPCs) of hyperlipidemic patients and to assess the correlation between NOX activity and the functions EPCs. METHODS: A total of 30 hyperlipidemic patients were enrolled for this study and 30 age-matched volunteers with normal level of plasma lipids served as controls. After the circulating EPCs were isolated, the EPC functions (migration, adhesion and tube formation) were evaluated and the status of NOX (expression and activity) was examined. RESULTS: Compared to the controls, hyperlipidemic patients showed an increase in plasma lipids and a reduction in EPC functions including the attenuated abilities in adhesion, migration and tube formation, concomitant with an increase in NOX expression (NOX2 and NOX4), NOX activity, and reactive oxygen species production. The data analysis showed negative correlations between NOX activity and EPC functions. CONCLUSIONS: There is a positive correlation between the NOX-mediated oxidative stress and the dysfunctions of circulating EPCs in hyperlipidemic patients, and suppression of NOX might offer a novel strategy to improve EPCs functions in hyperlipidemia.
Assuntos
Células Progenitoras Endoteliais/fisiologia , Hiperlipidemias/metabolismo , NADPH Oxidases/metabolismo , Estresse Oxidativo , Estudos de Casos e Controles , Adesão Celular , Movimento Celular , China , Células Progenitoras Endoteliais/metabolismo , Feminino , Humanos , Hiperlipidemias/fisiopatologia , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade , Espécies Reativas de OxigênioRESUMO
NADPH oxidase (NOX) is a major source of reactive oxygen species (ROS) in the body and it plays a key role in mediation of oxidative injury in the cardiovascular system. The purposes of this study are to evaluate the status of NOX in endothelial progenitor cells (EPCs) of hyperlipidemic rats and to determine whether NOX-derived ROS promotes the dysfunction of EPCs. The rats were fed on a high-fat diet for 8 weeks to establish a hyperlipidemic rat model, which showed the increased plasma lipids and the impaired functions of circulating EPCs (including the reduced abilities in migration and adhesion) accompanied by an increase in NOX activity and ROS production. Next, EPCs were isolated from normal rats and they were treated with oxidized low-density lipoprotein (ox-LDL) (100 µg/mL) for 24 h to induce a dysfunctional model in vitro. In agreement with our findings in vivo, ox-LDL treatment increased the dysfunctions of EPCs concomitant with an increase in NOX activity and ROS production; these phenomena were reversed by the NOX inhibitor. Based on these observations, we conclude that NOX-derived ROS involved in the dysfunctions of circulating EPCs in hyperlipidemic rats and inhibition of NOX might provide a novel strategy to improve EPC functions in hyperlipidemia.
Assuntos
Células Progenitoras Endoteliais/efeitos dos fármacos , Células Progenitoras Endoteliais/metabolismo , Hiperlipidemias/metabolismo , Hiperlipidemias/patologia , NADPH Oxidases/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Animais , Células Progenitoras Endoteliais/patologia , Inibidores Enzimáticos/farmacologia , Hiperlipidemias/induzido quimicamente , Lipoproteínas LDL/farmacologia , Masculino , NADPH Oxidases/antagonistas & inibidores , Fenótipo , Ratos , Ratos Sprague-DawleyRESUMO
Objective Circulating microRNAs have been recognized as promising biomarkers for various diseases. The aim of the present study was to explore the potential role of circulating miR-107, miR-128b and miR-153 as non-invasive biomarkers in the diagnosis of ischemia stroke. Methods One hundred and fourteen ischemic stroke patients (61±11.3 years old) and 58 healthy volunteers (56±3.9 years old) matched for age and sex were enrolled in this study. Total RNA was isolated from plasma with TRIzol reagent. The circulating microRNAs levels were measured by quantitative real-time polymerase chain reaction. Results The circulating levels of miR-107, miR-128b and miR-153 significantly increased 2.78-, 2.13- and 1.83-fold in ischemia stroke patients in comparison to the healthy volunteers, respectively. Receiver operating characteristic (ROC) curves were analyzed using the SPSS software program and revealed the areas under the curve for circulating miR-107, miR-128b and miR-153 to be 0.97, 0.903 and 0.893 in ischemia stroke patients in comparison to healthy volunteers, respectively. The levels of circulating miR-107, miR-128b and miR-153 therefore positively correlated with the severity of stroke as defined by NIHSS classes. Conclusion Our results suggest that circulating miR-107, miR-128b and miR-153 might be used as potential novel non-invasive biomarkers for the diagnosis of ischemia stroke. However, future prospective trials in large-sized patient cohorts are needed before drawing any definitive conclusions.
Assuntos
Isquemia Encefálica/diagnóstico , Encéfalo/metabolismo , MicroRNAs/sangue , Biomarcadores/sangue , Encéfalo/diagnóstico por imagem , Isquemia Encefálica/sangue , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Curva ROC , Reação em Cadeia da Polimerase em Tempo RealRESUMO
Suppression of dimethylarginine dimethylaminohydrolase (DDAH) activation is related to endothelial dysfunction in hyperlipidemia, and nonmuscle myosin regulatory light chain (nmMLC20) has been show to exert transcriptional function in regulation of gene expression. This study aims to explore whether the suppression of DDAH activation promotes endothelial injury under the condition of hyperlipidemia and whether nmMLC20 can regulate DDAH expression in a phosphorylation-dependent manner. The rats were fed with high-fat diet for 8 weeks to establish a hyperlipidemic model, which showed an increase in plasma lipids and endothelial injury, accompanied by an elevation in myosin light chain kinase (MLCK) activity, phosphorylated nmMLC20 (p-nmMLC20) level, and asymmetric dimethylarginine (ADMA) content as well as a reduction in DDAH2 expression, DDAH activity, and nitric oxide (NO) content. Next, human umbilical vein endothelial cells (HUVECs) were incubated with oxidized low-density lipoprotein (ox-LDL; 100 µg/mL) for 24 hours to establish a cellular injury model in vitro. Consistent with the finding in vivo, ox-LDL induced HUVECs injury (apoptosis and necrosis) concomitant with an increase in MLCK activity, p-nmMLC20 level (in total or nuclear proteins), and ADMA content as well as a reduction in DDAH2 expression, DDAH activity, and NO content; these phenomena were attenuated by MLCK inhibitor. Either in hyperlipidemic rats or in ox-LDL-treated HUVECs, there was not significant change in DDAH1 expression. Based on these observations, we conclude that the suppression of DDAH2 expression might account for, at least partially, the vascular endothelial dysfunction in hyperlipidemia, and nmMLC20 plays a role in suppression of DDAH2 expression in a phosphorylation-dependent manner.
Assuntos
Amidoidrolases/metabolismo , Aorta/enzimologia , Doenças da Aorta/enzimologia , Aterosclerose/enzimologia , Células Endoteliais/enzimologia , Hiperlipidemias/enzimologia , Cadeias Leves de Miosina/metabolismo , Animais , Aorta/efeitos dos fármacos , Aorta/patologia , Aorta/fisiopatologia , Doenças da Aorta/etiologia , Doenças da Aorta/patologia , Doenças da Aorta/fisiopatologia , Arginina/análogos & derivados , Arginina/metabolismo , Aterosclerose/etiologia , Aterosclerose/patologia , Aterosclerose/fisiopatologia , Células Cultivadas , Modelos Animais de Doenças , Regulação para Baixo , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/patologia , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/enzimologia , Células Endoteliais da Veia Umbilical Humana/patologia , Humanos , Hiperlipidemias/complicações , Hiperlipidemias/patologia , Hiperlipidemias/fisiopatologia , Lipídeos/sangue , Lipoproteínas LDL/farmacologia , Masculino , Quinase de Cadeia Leve de Miosina/antagonistas & inibidores , Quinase de Cadeia Leve de Miosina/metabolismo , Óxido Nítrico , Fosforilação , Inibidores de Proteínas Quinases/farmacologia , Ratos Sprague-Dawley , Transdução de Sinais , VasodilataçãoRESUMO
NADPH oxidase (NOX)-derived reactive oxygen species (ROS) is involved in endothelial dysfunction of hyperlipidemia, and non-muscle myosin regulatory light chain (nmMLC20) is reported to have a transcriptional function in regulation of gene expression. The purposes of this study are to determine whether NOX-derived ROS can promote endothelial progenitor cell (EPC) senescence and whether nmMLC20 can regulate NOX expression through a phosphorylation-dependent manner. The rats were subjected to 8 weeks of high-fat diet feeding to establish a hyperlipidemic model, which showed an increase in plasma lipids and the accelerated senescence and reduced number of circulating EPCs, accompanied by an increase in myosin light chain kinase (MLCK) and NOX activities, p-nmMLC20 level, NOX (NOX2, NOX4) expression, and H2O2 content. Next, EPCs isolated from normal rats were incubated with ox-LDL (100 µg/mL) for 24 h to establish a senescent model in vitro. Consistent with our in vivo findings, ox-LDL treatment increased the senescence of EPCs concomitant with an increase in MLCK and NOX activities, p-nmMLC20 level (in total or nuclear proteins), NOX expression, and H2O2 content; these phenomena were reversed by MLCK inhibitor. NOX inhibitor achieved similar results to that of MLCK inhibitor except that there is no effect on MLCK activity and p-nmMLC20 level. Furthermore, knockdown of nmMLC20, NOX2, or NOX4 led to a down-regulation in NOX and a reduction in ox-LDL-induced EPC senescence. These results suggest that NOX-derived ROS promotes the senescence of circulating EPCs in hyperlipidemia and nmMLC20 may play a transcriptional role in the upregulation of NOX through a phosphorylation-dependent manner.
Assuntos
Senescência Celular/fisiologia , Células Progenitoras Endoteliais/metabolismo , Hiperlipidemias/metabolismo , Cadeias Leves de Miosina/metabolismo , NADPH Oxidases/metabolismo , Animais , Azepinas/farmacologia , Benzoxazóis/farmacologia , Hiperlipidemias/sangue , Lipídeos/sangue , Masculino , Quinase de Cadeia Leve de Miosina/antagonistas & inibidores , Quinase de Cadeia Leve de Miosina/metabolismo , NADPH Oxidases/antagonistas & inibidores , NADPH Oxidases/genética , Naftalenos/farmacologia , Fosforilação , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/genética , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio , Triazóis/farmacologiaRESUMO
Recent studies demonstrated that NADPH oxidase 2 (NOX2) expression in myocardium after ischemia-reperfusion (IR) is significantly upregulated. However, the underlying mechanisms remain unknown. This study aims to determine if nuclear cardiac myosin light chain 2 (MYL2), a well-known regulatory subunit of myosin, functions as a transcription factor to promote NOX2 expression following myocardial IR in a phosphorylation-dependent manner. We examined the phosphorylation status of nuclear MYL2 (p-MYL2) in a rat model of myocardial IR (left main coronary artery subjected to 1 h ligation and 3 h reperfusion) injury, which showed IR injury and upregulated NOX2 expression as expected, accompanied by elevated H2O2 and nuclear p-MYL2 levels; these effects were attenuated by inhibition of myosin light chain kinase (MLCK). Next, we explored the functional relationship of nuclear p-MYL2 with NOX2 expression in H9c2 cell model of hypoxia-reoxygenation (HR) injury. In agreement with our in vivo findings, HR treatment increased apoptosis, NOX2 expression, nuclear p-MYL2 and H2O2 levels, and the increases were ameliorated by inhibition of MLCK or knockdown of MYL2. Finally, molecular biology techniques including co-immunoprecipitation (Co-IP), chromatin immunoprecipitation (ChIP), DNA pull-down and luciferase reporter gene assay were utilized to decipher the molecular mechanisms. We found that nuclear p-MYL2 binds to the consensus sequence AGCTCC in NOX2 gene promoter, interacts with RNA polymerase II and transcription factor IIB to form a transcription preinitiation complex, and thus activates NOX2 gene transcription. Our results demonstrate that nuclear MYL2 plays an important role in IR injury by transcriptionally upregulating NOX2 expression to enhance oxidative stress in a phosphorylation-dependent manner.
Assuntos
Miosinas Cardíacas/fisiologia , Glicoproteínas de Membrana/genética , Miocárdio/metabolismo , Cadeias Leves de Miosina/fisiologia , NADPH Oxidases/genética , Animais , Miosinas Cardíacas/análise , Núcleo Celular/química , Células Cultivadas , Masculino , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Cadeias Leves de Miosina/análise , Quinase de Cadeia Leve de Miosina/antagonistas & inibidores , NADPH Oxidase 2 , Estresse Oxidativo , Fosforilação , Ratos , Ratos Sprague-DawleyRESUMO
Previous studies have demonstrated that nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX)-mediated oxidative stress plays a key role in brain injury following cerebral ischemia/reperfusion (I/R) and myosin regulatory light chain kinase (MLCK) has been reported to be involved in NOX activation in lung endothelium. This study was performed to explore the correlation between MLCK and NOX following cerebral I/R and the underlying mechanisms. Sprague-Dawley (SD) rats were subjected to 2 h middle cerebral artery occlusion and 24 h reperfusion to establish a model of focal cerebral I/R injury. At the end of experiments, neurological function, infarct volume, cellular apoptosis, activities of MLCK and NOX, messenger RNA (mRNA) and protein expression of NOX (NOX1-NOX4), phosphorylation level of myosin regulatory light chain (MLC20) and hydrogen peroxide (H2O2) level were determined. The results showed that I/R treatment led to increase in neurological deficit score, infarct volume and cellular apoptosis, accompanied by the elevated activities of MLCK and NOX, expressions of NOX2 and NOX4, levels of phosphorylation MLC20 and H2O2, these effects were attenuated by MLCK specific inhibitor (ML-7). NOX inhibitors (diphenylene iodonium (DPI) or apocynin) were able to achieve similar results to that of ML-7 except no effect on MLCK activity and MLC20 phosphorylation. These results suggest that activation of MLCK contributes to cerebral I/R oxidative injury through upregulation of NOX2 and NOX4 expression, which is involved in phosphorylation of MLC20.
Assuntos
Isquemia Encefálica/fisiopatologia , Quinase de Cadeia Leve de Miosina/antagonistas & inibidores , NADPH Oxidases/metabolismo , Traumatismo por Reperfusão/fisiopatologia , Animais , Azepinas/farmacologia , Encéfalo/fisiopatologia , Isquemia Encefálica/prevenção & controle , Modelos Animais de Doenças , Peróxido de Hidrogênio/metabolismo , Masculino , Glicoproteínas de Membrana/genética , Cadeias Leves de Miosina/metabolismo , Quinase de Cadeia Leve de Miosina/metabolismo , NADPH Oxidase 2 , NADPH Oxidase 4 , NADPH Oxidases/genética , Naftalenos/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Fosforilação/fisiologia , Ratos , Ratos Sprague-Dawley , Traumatismo por Reperfusão/prevenção & controle , Regulação para CimaRESUMO
Recent studies have uncovered that accumulation of glutamate after ischaemic stroke is closely associated with the down-regulation of glutamate transporter-1 (GLT-1) expression, suggesting that GLT-1 expression critically controls glutamate accumulation and the abnormal glutamate transport-elicited neuronal cell excitotoxicity in patients with ischaemic stroke. However, it remains unknown how GLT-1 expression is regulated under ischaemic stroke conditions. In the present study, we screened the expression of nine brain-specific or brain-enriched miRNAs in a focal cerebral ischaemia/reperfusion (I/R) injury rat model, which showed glutamate accumulation and down-regulated GLT-1 expression as expected, and revealed that the miR-107 level was elevated in both brain tissue and plasma in the model. Next, we examined the functional relationship of miR-107 with GLT-1 expression in a nerve cell hypoxia/reoxygenation (H/R) injury model. H/R treatment increased apoptosis of the nerve cells concomitant with glutamate accumulation, miR-107 elevation and suppressed GLT-1 expression, mimicking our in vivo findings in the cerebral I/R injury rat model in vitro. Co-treating the cells with an miR-107 inhibitor blocked all of the effects, demonstrating that miR-107 functions to inhibit GLT-1 expression and elevate glutamate accumulation. To extend these animal and cell-based studies to clinical patients, we measured the plasma levels of miR-107 and glutamate, and observed that both miR-107 and glutamate were elevated in patients with ischaemic stroke. On the basis of these observations, we conclude that elevated miR-107 expression after ischaemic stroke accounts, at least partially, for glutamate accumulation through suppression of GLT-1 expression. Our findings also highlight that the plasma level of miR-107 may serve as a novel biomarker for monitoring excitotoxicity in patients with ischaemic stroke.
Assuntos
Isquemia Encefálica/genética , Transportador 2 de Aminoácido Excitatório/metabolismo , MicroRNAs/fisiologia , Acidente Vascular Cerebral/genética , Animais , Apoptose , Encéfalo/metabolismo , Isquemia Encefálica/metabolismo , Isquemia Encefálica/patologia , Hipóxia Celular/genética , Regulação para Baixo , Transportador 2 de Aminoácido Excitatório/genética , Feminino , Ácido Glutâmico/metabolismo , Humanos , Masculino , MicroRNAs/antagonistas & inibidores , MicroRNAs/sangue , MicroRNAs/metabolismo , Pessoa de Meia-Idade , Interferência de RNA , RNA Antissenso/farmacologia , Ratos , Ratos Sprague-Dawley , Acidente Vascular Cerebral/metabolismo , Acidente Vascular Cerebral/patologia , Regulação para CimaRESUMO
Vitexin compound B-1 (VB-1) is a novel member of the vitexins family isolated from the seeds of the Chinese herb Vitex negundo. This study aims to investigate whether VB-1 is able to protect nerve cells against oxidative injury and whether the antioxidative effects of VB-1 occur through a mechanism involving the inhibition of NADPH oxidase (NOX) in a manner of hypoxia-inducible factor 1α (HIF-1α)-dependent. To establish a neuronal in vitro model of oxidative stress, the differentiated PC12 cells were subjected to 5 h of hypoxia followed by 20 h of reoxygenation (H/R). Three dosages of VB-1 (10(-8), 10(-7), and 10(-6) M) were chosen to evaluate the effect of VB-1 on H/R-induced injury and the underlying mechanisms. At the end of the experiments, culture mediums and cells were collected for analysis of cellular apoptosis, lactate dehydrogenase (LDH) and caspase 3/7-like activities, reactive oxygen species (ROS) levels, 4-hydroxynonenal (4-HNE) and malondialdehye (MDA) contents, and HIF-1α and NOX expression, respectively. Our results showed that cell injury (indicated by apoptosis ratio, caspase 3/7-like activity, and LDH release), oxidative stress (indicated by ROS production, 4-HNE, and MDA contents), NOX activity, and NOX expression (NOX2 and NOX4 isoforms) were dramatically increased in PC12 cells following H/R, which were attenuated in the presence of VB-1 at dosage of 10(-7) or 10(-6) M. There was no significant change in HIF-1α expression in all experimental groups. These results provide evidence that VB-1 is able to protect the PC12 cells against H/R-induced injury through a mechanism involving the suppression of NOX expression and subsequent reduction of ROS production. The effect of VB-1 on H/R-induced NOX expression is independent on HIF-1α inhibition.
Assuntos
Aldeídos/farmacologia , Hipóxia/metabolismo , Lignanas/farmacologia , NADPH Oxidases/antagonistas & inibidores , Fármacos Neuroprotetores/farmacologia , Aldeídos/metabolismo , Animais , Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , Caspase 7/metabolismo , Diferenciação Celular , Malondialdeído/metabolismo , NADPH Oxidases/genética , NADPH Oxidases/metabolismo , Células PC12 , RNA Mensageiro/metabolismo , Ratos , Espécies Reativas de Oxigênio/metabolismoRESUMO
Recent studies show that resveratrol exerts beneficial effects on prevention of pulmonary hypertension. This study is performed to explore the effects of trimethoxystilbene, a novel resveratrol analog, on rat pulmonary vascular remodeling and right ventricular hypertrophy in hypoxia-induced pulmonary arterial hypertension (PAH) and the underlying mechanisms. Sprague-Dawley rats were placed in a chamber and exposed to 10% O(2) continuously for 4 weeks to induce PAH. The effects of trimethoxystilbene (5 or 10 mg/kg per day, intragastric [i.g.]) and resveratrol (as a positive control, 25 mg/kg per day, i.g.) on hypoxia-induced PAH vascular remodeling and right ventricle hypertrophy were evaluated. At the end of experiments, the index for pulmonary vascular remodeling and right ventricle hypertrophy, inflammatory cell infiltration in lung tissue, the plasma levels and lung tissue contents of hydrogen peroxide (H(2)O(2)), the mRNA and protein levels for NADPH oxidases (NOX2, NOX4) and vascular peroxidase 1 (VPO1) in pulmonary artery or right ventricle were measured. The results showed that trimethoxystilbene treatment significantly attenuated hypoxia-induced pulmonary vascular remodeling (such as decrease in the ratio of wall thickness to vessel external diameter) and right ventricle hypertrophy (such as decrease in the ratio of right ventricle weight to the length of the tibia), accompanied by downregulation of NOX2, NOX4, and VPO1 expression in pulmonary artery or right ventricle, decrease in H(2)O(2) production and inflammatory cell infiltration in lung tissue. Trimethoxystilbene is able to prevent pulmonary vascular remodeling and right ventricle hypertrophy in hypoxia-induced rat model of PAH, which is related to inhibition of the NOX/VPO1 pathway-mediated oxidative stress and the inflammatory reaction.
Assuntos
Hemeproteínas/antagonistas & inibidores , Hipertensão Pulmonar/tratamento farmacológico , Hipóxia/tratamento farmacológico , Glicoproteínas de Membrana/antagonistas & inibidores , NADPH Oxidases/antagonistas & inibidores , Peroxidases/antagonistas & inibidores , Estilbenos/farmacologia , Remodelação Ventricular/efeitos dos fármacos , Animais , Hemeproteínas/metabolismo , Hipertensão Pulmonar/enzimologia , Hipertensão Pulmonar/etiologia , Hipóxia/complicações , Hipóxia/enzimologia , Inflamação/tratamento farmacológico , Inflamação/enzimologia , Masculino , Glicoproteínas de Membrana/metabolismo , NADPH Oxidase 2 , NADPH Oxidase 4 , NADPH Oxidases/metabolismo , Peroxidases/metabolismo , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Resveratrol , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Estilbenos/química , Estilbenos/uso terapêutico , Remodelação Ventricular/fisiologiaRESUMO
Many studies demonstrate that accumulation of reactive aldehydes plays an important role in cellular oxidative injury and aldehyde dehydrogenase 2 (ALDH2)-mediated detoxification of reactive aldehydes is thought as an endogenous protective mechanism against cell injury. This study was performed to explore whether Alda-1, a newly identified ALDH2 activator, was able to protect brain against ischemia/reperfusion injury through clearance of reactive aldehydes. In a rat model of focal cerebral ischemia/reperfusion injury, neurological function, infarct volume, cellular apoptosis, mortality, ALDH2 activity and protein expression, contents of 4-hydroxy-2-nonenal (4-HNE), and malondialdehyde (MDA) were determined. The results showed that ischemia/reperfusion treatment led to increase in neurological deficit score, infarct volume, cellular apoptosis, and mortality accompanied by the elevated levels of reactive aldehydes (4-HNE and MDA). There was no significant change in ALDH2 activity and protein expression. Alda-1 treatment at both dosages (15 mg/kg × 2 or 50 mg/kg × 2, i.g.) was able to increase the activity of ALDH2 and decrease the accumulation of reactive aldehydes concomitantly with the improvement of brain injury (decrease in infarct volume, cellular apoptosis, and mortality) and neurological function (decrease in neurological deficit score). However, Alda-1 treatment did not affect ALDH2 protein expression. Our results suggest that the protective effect of Alda-1 on cerebral ischemia/reperfusion injury is related to ALDH2 activation and clearance of reactive aldehydes.
Assuntos
Aldeído Desidrogenase/metabolismo , Benzamidas/uso terapêutico , Benzodioxóis/uso terapêutico , Isquemia Encefálica/tratamento farmacológico , Isquemia Encefálica/metabolismo , Proteínas Mitocondriais/metabolismo , Traumatismo por Reperfusão/tratamento farmacológico , Traumatismo por Reperfusão/metabolismo , Aldeído-Desidrogenase Mitocondrial , Aldeídos/metabolismo , Animais , Benzamidas/farmacologia , Benzodioxóis/farmacologia , Masculino , Taxa de Depuração Metabólica/efeitos dos fármacos , Taxa de Depuração Metabólica/fisiologia , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Distribuição Aleatória , Ratos , Ratos Sprague-DawleyRESUMO
MicroRNAs (miRNAs) have been shown to be closely associated with cellular apoptosis, but their involvement in response to ethanol-induced gastric mucosal epithelial cell apoptosis remains largely unknown. The purpose of this study was to investigate the expression profile of apoptosis-associated miRNAs in ethanol-induced acute gastric mucosal injury and the mechanisms underlying injury. Gastric mucosal injury was induced in rats by oral administration of ethanol, and gastric tissues were collected for analysis of gastric ulcer index, apoptosis ratio, caspase-3 activity, and miRNAs expression. Cell cultures of human gastric mucosal epithelial cells (GES-1) were incubated with ethanol to induce apoptosis. Mimics or inhibitors of miRNAs or c-Jun N-terminal kinase (JNK) inhibitor were added to the cell culture medium. GES-1 cells were collected for analysis of apoptosis ratio, caspase-3 activity, miRNAs expression, and protein phosphorylation levels of JNK, p38 mitogen-activated protein kinase (p38MAPK), or extracellular signal-regulated kinase (ERK). In the animal experiments, gastric ulcer index, cellular apoptosis, and caspase-3 activity were significantly increased, accompanied by up-regulation of miR-145 and down-regulation of the microRNAs miR-17, miR-19a, miR-21, miR-181a, and miR-200c. In the human cell culture experiments, the anti-apoptotic effects of miR-19a and miR-21 or pro-apoptotic effect of miR-145 were confirmed by their corresponding mimics or inhibitor; the ethanol-induced GES-1 apoptosis as well as the changes in miRNAs expression were significantly attenuated in the presence of JNK inhibitor. These results demonstrated that miR-145, miR-19a, and miR-21 were the apoptosis-associated miRNAs in gastric mucosal epithelial cells. The regulation of expression of these 3 miRNAs in ethanol-induced GES-1 apoptosis involved the JNK pathway.