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OBJECTIVE: Recent literature has suggested that functional seizures are associated with an elevated risk for vascular disease and mortality. We investigated the prevalence of risk factors for vascular disease in patients who were admitted to the epilepsy monitoring unit. METHODS: Patients who were admitted to the epilepsy monitoring unit and received a definitive diagnosis of either functional seizures or epilepsy were identified. Data collected included demographic, clinical characteristics, medication list, comorbidities, and scheduled blood pressure measurements that occurred every 12 h during the admission. The mean blood pressures were calculated and if they were above the American College of Cardiology and the American Heart Association guideline cutoff of 130/80 mm Hg or the patient had a documented history of hypertension the patient was counted as having the condition. A multiple logistic regression model was developed to evaluate the independent association of the patient's diagnosis (i.e., epilepsy or functional seizures) and vascular risk factors that controlled for the number of blood pressure measurements, age, sex, and if the patient was taking antihypertensive medications. RESULTS: 270 patients were included in this study of which 147 patients had epilepsy and 123 had functional seizures. Among those with functional seizures, 57.72 % had either a history of hypertension or a mean blood pressure above 130/80 compared to 38.78 % of those with epilepsy (p = 0.0022). In addition, 30.89 % of functional seizures patients had hyperlipidemia and 63.41 % were obese. The logistic regression model indicated that functional seizures were independently associated with high blood pressure (OR: 2.47, 95 % CI 1.10-5.69), hyperlipidemia (OR: 3.38, 95 % CI 1.35-8.86), and obesity (OR: 4.25, 95 % CI 2.22-8.36) compared to those with epilepsy. There was no significant difference in the prevalence of diabetes (OR: 0.81, 95 % CI 0.24-2.77) or current tobacco use (OR: 1.04, 95 % CI 0.48-2.25) between the groups. SIGNIFICANCE: Patients with functional seizures had an elevated prevalence of several vascular risk factors. These findings may partially account for complications associated with functional seizures and have implications related to their pathophysiology.
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Epilepsia , Hiperlipidemias , Hipertensão , Humanos , Convulsões/complicações , Convulsões/diagnóstico , Convulsões/epidemiologia , Hipertensão/complicações , Hipertensão/epidemiologia , Hipertensão/tratamento farmacológico , Epilepsia/complicações , Epilepsia/epidemiologia , Epilepsia/diagnóstico , Fatores de RiscoRESUMO
BACKGROUND: We investigated childhood-onset functional seizures (FS) and late-onset FS and hypothesized that there are differences in their characteristics. METHODS: In this retrospective study, we investigated all patients with confirmed FS with an age at onset of 14 years or younger and those with an age at onset of 50 years or older, who were admitted to the epilepsy monitoring units at one center in Iran (Shiraz Comprehensive Epilepsy Center, from 2008 until 2022) and one center in the USA (Vanderbilt University Medical Center, from 2011 until 2022). RESULTS: One-hundred and forty patients were included. They included 80 patients with childhood-onset FS and 60 with late-onset FS. Those with late-onset FS were more likely to have medical comorbidities compared with the patients with childhood-onset FS (OR = 13.9). Those with late-onset FS more likely had a history of head injury compared with the patients with childhood-onset FS (OR = 5.97). Duration of illness was significantly longer in patients with childhood-onset FS compared with the patients with late-onset FS (6 years vs. 2 years). CONCLUSION: Our study identified several similarities and differences in the clinical characteristics and predisposing factors of patients with childhood-onset and late-onset FS. In addition, we found that childhood-onset FS is more likely to remain undiagnosed and thus untreated for many years. These findings provide additional evidence that FS is a heterogenous condition and we propose that a proportion of the differences between patients may be accounted for by age-associated factors.
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Eletroencefalografia , Epilepsia , Humanos , Estudos Retrospectivos , Convulsões/diagnóstico , Convulsões/epidemiologia , Epilepsia/diagnóstico , ComorbidadeRESUMO
The present study was designed to investigate the neuroprotective effect of naringin (NR) alone as well as its combination with sertraline (SRT) against doxorubicin (DOX)-induced neurobehavioral and neurochemical anomalies. DOX (15 mg/kg; i.p.) administration caused behavioral alterations, oxidative stress, neuroinflammation, mitochondrial dysfunction and monoamines alteration in male Wistar rats. NR (50 and 100 mg/kg; i.p.) and SRT (5 mg/kg; i.p.) treatment significantly attenuated DOX-induced anxiety and depressive-like behavior as evident from elevated plus maze (EPM) and modified forced swimming test (mFST), respectively. NR treatment significantly attenuated DOX-induced raised plasma corticosterone (CORT), tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1ß) levels in the hippocampus (HC). Furthermore, we found that combination of NR and SRT regimen ameliorated DOX-induced behavioral anomalies through modulation of the 5-HT level and mitochondrial complexes protection pathway along with alleviation of oxidative stress in the HC region. Therefore, NR treatment alone or in combination with SRT could be beneficial against DOX-induced neurotoxicity.
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Comportamento Animal/efeitos dos fármacos , Flavanonas/farmacologia , Hipocampo/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Serotonina/metabolismo , Sertralina/farmacologia , Animais , Corticosterona/sangue , Depressão/tratamento farmacológico , Depressão/metabolismo , Doxorrubicina/farmacologia , Hipocampo/metabolismo , Masculino , Mitocôndrias/metabolismo , Fármacos Neuroprotetores/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Ratos WistarRESUMO
CONTEXT: Doxorubicin (Dox) is one of the most active chemotherapeutic agents used to treat various types of cancers. Its clinical utility is compromised due to fatal cardiac toxicity characterized by an irreversible cardiomyopathy. OBJECTIVE: This study evaluates the cardioprotective potential of naringin (NR) against Dox-induced acute cardiac toxicity in rats. MATERIALS AND METHODS: Male Wistar rats were randomly divided into five groups. NR (50 and 100 mg/kg) was administered intraperitoneally (i.p.) daily from 0 to 14 d. Doxorubicin (15 mg/kg, i.p.) was given as a single dose on the 10th day. On the 14th day, all animals were sacrificed and oxidative stress parameters that include malondialdehyde (MDA), glutathione (GSH) level, superoxide dismutase (SOD), catalase (CAT) activities, and all mitochondrial complexes (I-IV) activities were evaluated along with histopathological studies of the heart. RESULTS: Doxorubicin-induced cardiotoxicity was confirmed by increased (p < 0.05) MDA, decreased (p < 0.05) GSH levels, SOD, and CAT activities, mitochondrial complexes (I-IV) activities in the heart tissue. NR (100 mg/kg) showed cardioprotection as evident from significant decreased MDA (p < 0.001) level, raised (p < 0.001) GSH level, SOD and CAT activities and increased mitochondrial complexes I (p < 0.01), II (p < 0.001), III (p < 0.001), and IV (p < 0.05) activities. Further, Dox-induced cardiotoxicity was confirmed by histopathological studies. These obtained results indicated the protective role of NR against Dox-induced cardiac toxicity in rats. CONCLUSION: NR can be used in combination with Dox due to its high cardioprotective effect against Dox-induced cardiomyopathy.
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Antibióticos Antineoplásicos/toxicidade , Cardiotoxicidade/tratamento farmacológico , Doxorrubicina/toxicidade , Flavanonas/uso terapêutico , Animais , Cardiotoxicidade/metabolismo , Flavanonas/farmacologia , Peroxidação de Lipídeos/efeitos dos fármacos , Peroxidação de Lipídeos/fisiologia , Masculino , Mitocôndrias Cardíacas/efeitos dos fármacos , Mitocôndrias Cardíacas/metabolismo , Ratos , Ratos Wistar , Resultado do TratamentoRESUMO
Sulfiredoxin (Srx), the exclusive enzyme that reduces the hyperoxidized inactive form of peroxiredoxins (Prxs), has been found highly expressed in several types of human skin cancer. To determine whether Srx contributed to skin tumorigenesis in vivo, Srx null mice were generated on an FVB background. Mouse skin tumorigenesis was induced by a 7,12-dimethylbenz[α]anthracene/12-O-tetradecanoylphorbol-13-acetate (DMBA/TPA) protocol. We found that the number, volume and size of papillomas in Srx(-/-) mice were significantly fewer compared with either wild-type (Wt) or heterozygous (Het) siblings. Histopathological analysis revealed more apoptotic cells in tumors from Srx(-/-) mice. Mechanistic studies in cell culture revealed that Srx was stimulated by TPA in a redox-independent manner. This effect was mediated transcriptionally through the activation of mitogen-activated protein kinase and Jun-N-terminal kinase. We also demonstrated that Srx was capable of reducing hyperoxidized Prxs to facilitate cell survival under oxidative stress conditions. These findings suggested that loss of Srx protected mice, at least partially, from DMBA/TPA-induced skin tumorigenesis. Therefore, Srx has an oncogenic role in skin tumorigenesis and targeting Srx may provide novel strategies for skin cancer prevention or treatment.
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Transformação Celular Neoplásica/genética , Oxirredutases atuantes sobre Doadores de Grupo Enxofre/genética , Neoplasias Cutâneas/genética , Pele/metabolismo , Pele/patologia , 9,10-Dimetil-1,2-benzantraceno/efeitos adversos , Animais , Apoptose/efeitos dos fármacos , Apoptose/genética , Linhagem Celular , Proliferação de Células , Transformação Celular Neoplásica/efeitos dos fármacos , Transformação Celular Neoplásica/metabolismo , Modelos Animais de Doenças , Regulação da Expressão Gênica/efeitos dos fármacos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Camundongos , Camundongos Knockout , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Oxirredução , Oxirredutases atuantes sobre Doadores de Grupo Enxofre/metabolismo , Pele/efeitos dos fármacos , Neoplasias Cutâneas/induzido quimicamente , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/patologia , Acetato de Tetradecanoilforbol/efeitos adversos , Ativação Transcricional/efeitos dos fármacosRESUMO
INTRODUCTION: Neuropsychological testing is a mandatory component in the evaluation of drug resistant epilepsy. The results of testing may assist with both the localization of an epilepsy as well as assessment of surgical risk. Previous studies have demonstrated differences in the neuropsychological performance of patients with epilepsy and functional seizures. We hypothesized that comorbid functional seizures could potentially influence neuropsychological test performance. Therefore, we evaluated whether there is a difference in the neuropsychological test results between drug resistant epilepsy patients with and without comorbid functional seizures. METHOD: Neuropsychological test results were compared between 25 patients with drug resistant focal epilepsy and 25 patients that also had documented functional seizures. Univariate analyses and multiple logistic regression models were used to both assess performance differences between the groups and to assess whether test results could be used to accurately identify which patients had comorbid functional seizures. RESULTS: Epilepsy patients with comorbid functional seizures performed significantly worse on the FAS Verbal Fluency Test compared to ES patients (p = 0.047). Digit Span Backwards (p = 0.10), Digit Span Forwards (p = 0.14) and Working Memory Index (p = 0.10) tended to be lower in the epilepsy and functional seizures group but was not statistically significant. A multiple logistic regression model using the results of four neuropsychological tests was able to identify patients with comorbid functional seizures with 83.33% accuracy. CONCLUSIONS: There are appeared to be some differences in the neuropsychological performance among drug resistant epilepsy patients based on whether they have comorbid functional seizures. These findings may have relevant implications for the interpretation of neuropsychological test results.
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Epilepsia Resistente a Medicamentos , Humanos , Epilepsia Resistente a Medicamentos/complicações , Epilepsia Resistente a Medicamentos/tratamento farmacológico , Epilepsia Resistente a Medicamentos/epidemiologia , Convulsões/complicações , Convulsões/tratamento farmacológico , Convulsões/epidemiologia , Comorbidade , Modelos Logísticos , Memória de Curto PrazoRESUMO
Background: Moyamoya disease (MMD) is a non-atherosclerotic intracranial steno-occlusive condition placing patients at high risk for ischemic stroke. Direct and indirect surgical revascularization can improve blood flow in MMD; however, randomized trials demonstrating efficacy have not been performed and biomarkers of parenchymal hemodynamic impairment are needed to triage patients for interventions and evaluate post-surgical efficacy. We test the hypothesis that hypercapnia-induced maximum cerebrovascular reactivity (CVR MAX ) and the more novel indicator cerebrovascular reactivity (CVR) response time (CVR DELAY ), both assessed from time-regression analyses of non-invasive hypercapnic imaging, correlate with recent focal ischemic symptoms. Methods: Hypercapnic reactivity medical resonance imaging (blood oxygenation level-dependent; echo time=35ms; spatial resolution=3.5×3.5×3.5mm) and catheter angiography assessments of cortical reserve capacity and vascular patency, respectively, in MMD participants (n=73) were performed in sequence. Time regression analyses were applied to quantify CVR MAX and CVR DELAY . Symptomatology information for each hemisphere (n=109) was categorized into symptomatic (ischemic symptoms within six months) or asymptomatic (no history of ischemic symptoms) and logistic regression analysis assessed the association of CVR metrics with ischemic symptoms after controlling for age and sex. Results: Symptomatic hemispheres displayed lengthened CVR DELAY (p<0.001), which was more discriminatory between hemispheres than CVR MAX (p=0.037). CVR DELAY (p<0.001), but not CVR MAX (p=0.127), was found to be sensitively related to age in asymptomatic tissue (0.33-unit increase/year); age-dependent normative ranges are presented to enable quantitative assessment of patient-specific impairment. Furthermore, the area under the receiver operating characteristic curves shows that CVR DELAY predicts ischemic symptoms (p<0.001), whereas CVR MAX does not (p=0.056). Conclusion: Findings support that CVR metrics are uniquely altered in hemispheres with recent ischemic symptoms, motivating the investigation of CVR as a surrogate of ischemic symptomatology and treatment efficacy.
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The identification of the fundamental role of apoptosis in the growth balance and normal homeostasis against cell proliferation led to the recognition of its loss contributing to tumorigenesis. The mechanistic significance of reinstating apoptosis signaling towards selective targeting of malignant cells heavily exploits the caspase family of death-inducing molecules as a powerful therapeutic platform for the development of potent anticancer strategies. Some apoptosis inhibitors induce caspase expression and activity in preclinical models and clinical trials by targeting both the intrinsic and extrinsic apoptotic pathways and restoring the apoptotic capacity in human tumors. Furthermore, up-regulation of caspases emerges as a sensitizing mechanism for tumors exhibiting therapeutic resistance to radiation and adjuvant chemotherapy. This review provides a comprehensive discussion of the functional involvement of caspases in apoptosis control and the current understanding of reactivating caspase-mediated apoptosis signaling towards effective therapeutic modalities in cancer treatment.
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Inibidores de Caspase/farmacologia , Caspases/metabolismo , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/enzimologia , Apoptose/efeitos dos fármacos , Inibidores de Caspase/uso terapêutico , Proliferação de Células/efeitos dos fármacos , Humanos , Masculino , Neoplasias Hormônio-Dependentes/tratamento farmacológico , Neoplasias Hormônio-Dependentes/enzimologia , Neoplasias Hormônio-Dependentes/patologia , Neoplasias da Próstata/patologia , Transdução de Sinais/efeitos dos fármacosRESUMO
Sulfiredoxin (Srx) is the enzyme that restores the peroxidase activity of peroxiredoxins (Prxs) through catalyzing the reduction of hyperoxidized Prxs back to their active forms. This process involves protein-protein interaction in an enzyme-substrate binding manner. The integrity of the Srx-Prx axis contributes to the pathogenesis of various oxidative stress related human disorders including cancer, inflammation, cardiovascular and neurological diseases. The purpose of this study is to understand the structural and molecular biology of the Srx-Prx interaction, which may be of significance for prediction of target site for the novel drug-discovery. Homology modeling and protein-protein docking approaches were applied to examine the Srx-Prx interaction using online platforms including ITASSER, Phyre2, Swissmodel, AlphaFold, MZDOCK and ZDOCK. By in-silico studies, A 26-amino acid motif at the C-terminus of Prx1 was predicted to cause a steric hindrance for the kinetics of the Srx-Prx1 interaction. These predictions were tested in-vitro using purified recombinant proteins including Srx, full-length Prxs, and C-terminus deleted Prxs. We confirmed that deletion of the C-terminus of Prxs significantly enhanced its rate of association with Srx (i.e. >1000 fold increase in the ka of the Srx-Prx1 interaction) with minimal effect on the rate of dissociation (kd). Differential interaction of Srx with individual members of the Prx family was further examined in cultured cells. Taken together, these data add novel molecular and structural insights critical for the understanding of the biology of the Srx-Prx interaction that may be of value for the development of targeted therapy for human disorders.
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Oxirredutases atuantes sobre Doadores de Grupo Enxofre , Peroxirredoxinas , Humanos , Peroxirredoxinas/genética , Peroxirredoxinas/metabolismo , Oxirredutases atuantes sobre Doadores de Grupo Enxofre/química , Oxirredutases atuantes sobre Doadores de Grupo Enxofre/metabolismo , Antioxidantes/metabolismo , Estresse Oxidativo , Células Cultivadas , OxirreduçãoRESUMO
BACKGROUND: Postural instability is a disease milestone signaling advanced disease. OBJECTIVES: To estimate the onset of postural instability in monogenic parkinsonisms. METHODS: We systematically reviewed studies (PubMed 1996-2017) in SNCA, PRKN, PINK1, DJ-1, LRRK2, ATP13A2, FBXO7, VPS35, DNAJC6, or SYNJ1-related monogenic parkinsonisms, with documented postural instability. Genes with ≥ 15 patients were included in an individual-patient meta-analysis and compared with a retrospectively collected sporadic Parkinson's disease cohort from our center. The primary outcome measure was the progression-free survival from postural instability using Kaplan-Meier survival curves. Cox proportional hazards analyses were summarized using hazards ratio (HR). RESULTS: Of 2085 eligible studies, 124 met full criteria (636 patients) for the systematic review, whereas a total of 871 subjects (270 from sporadic cohort, 601 monogenic parkinsonisms) were included in the individual-patient meta-analysis. Postural instability was reported in 80% of DJ-1, 40% of PRKN, 39% of PINK1, 34% of ATP13A2, 31% of LRRK2, and 29% of SNCA patients. Progression-free survival from postural instability at 10 years after disease onset was longest in ATP13A2 (97%) and shortest in SNCA (50%). Halfway between these two extremes were PRKN (88%), PINK1 (87%), and LRRK2 (81%), similar to sporadic Parkinson's disease (72%). Higher risk of postural instability was observed in SNCA (HR = 3.2, p = 0.007) and DJ-1 (HR = 3.96, p = 0.001) compared to sporadic Parkinson's disease. Young age at onset in PINK1 and female sex in LRRK2 were associated with a decreased risk of postural instability. CONCLUSIONS: Monogenic parkinsonisms exhibit differential timelines to postural instability, informing prognostic counseling and interpretation of future genotype-specific treatment trials.
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Doença de Parkinson , Transtornos Parkinsonianos , Estudos de Coortes , Feminino , Genótipo , Humanos , Doença de Parkinson/genética , Estudos RetrospectivosRESUMO
Lung cancer is the leading cause of cancer death worldwide. Cigarette smoking and exposure to chemical carcinogens are among the risk factors of lung tumorigenesis. In this study, we found that cigarette smoke condensate and urethane significantly stimulated the expression of sulfiredoxin (Srx) at the transcript and protein levels in cultured normal lung epithelial cells, and such stimulation was mediated through the activation of nuclear related factor 2 (Nrf2). To study the role of Srx in lung cancer development in vivo, mice with Srx wildtype, heterozygous or knockout genotype were subjected to the same protocol of urethane treatment to induce lung tumors. By comparing tumor multiplicity and volume between groups of mice with different genotype, we found that Srx knockout mice had a significantly lower number and smaller size of lung tumors. Mechanistically, we demonstrated that loss of Srx led to a decrease of tumor cell proliferation as well as an increase of tumor cell apoptosis. These data suggest that Srx may have an oncogenic role that contributes to the development of lung cancer in smokers or urethane-exposed human subjects.
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Carcinogênese/patologia , Carcinógenos/toxicidade , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Neoplasias Pulmonares/patologia , Fator 2 Relacionado a NF-E2/metabolismo , Oxirredutases atuantes sobre Doadores de Grupo Enxofre/fisiologia , Uretana/toxicidade , Animais , Apoptose , Carcinogênese/induzido quimicamente , Carcinogênese/metabolismo , Proliferação de Células , Células Cultivadas , Feminino , Humanos , Neoplasias Pulmonares/induzido quimicamente , Neoplasias Pulmonares/metabolismo , Camundongos , Camundongos Knockout , Fator 2 Relacionado a NF-E2/genética , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismoRESUMO
INTRODUCTION: We sought to review the landscape of past, present, and future use of technology-based outcome measures (TOMs) in clinical trials of neurodegenerative disorders. METHODS: We systematically reviewed PubMed and ClinicalTrials.gov for published and ongoing clinical trials in neurodegenerative disorders employing TOMs. In addition, medical directors of selected pharmaceutical companies were surveyed on their companies' ongoing efforts and future plans to integrate TOMs in clinical trials as primary, secondary, or exploratory endpoints. RESULTS: We identified 164 published clinical trials indexed in PubMed that used TOMs as outcome measures in Parkinson disease (n = 132) or other neurodegenerative disorders (n = 32). The ClinicalTrials.gov search yielded 42 clinical trials using TOMs, representing 2.7% of ongoing trials. Sensor-based technology accounted for over 75% of TOMs applied. Gait and physical activity were the most common targeted domains. Within the next 5 years, 83% of surveyed pharmaceutical companies engaged in neurodegenerative disorders plan to deploy TOMs in clinical trials. CONCLUSION: Although promising, TOMs are underutilized in clinical trials of neurodegenerative disorders. Validating relevant endpoints, standardizing measures and procedures, establishing a single platform for integration of data and algorithms from different devices, and facilitating regulatory approvals should advance TOMs integration into clinical trials.
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Ensaios Clínicos como Assunto/métodos , Doenças Neurodegenerativas/tratamento farmacológico , Avaliação de Resultados em Cuidados de Saúde/métodos , Doença de Parkinson/tratamento farmacológico , Bases de Dados Bibliográficas/estatística & dados numéricos , HumanosRESUMO
Redox signaling is a critical component of cell signaling pathways that are involved in the regulation of cell growth, metabolism, hormone signaling, immune regulation and variety of other physiological functions. Peroxiredoxin (Prx) is a family of thiol-based peroxidase that acts as a regulator of redox signaling. Members of Prx family can act as antioxidants and chaperones. Sulfiredoxin (Srx) is an antioxidant protein that exclusively reduces over-oxidized typical 2-Cys Prx. Srx has different affinities for individual Prx and it also catalyzes the deglutathionylation of variety of substrates. Individual component of the Srx-Prx system plays critical role in carcinogenesis by modulating cell signaling pathways involved in cell proliferation, migration and metastasis. Expression levels of individual component of the Srx-Prx axis have been correlated with patient survival outcome in multiple cancer types. This review will summarize the molecular basis of differences in the affinity of Srx for individual Prx and the role of individual component of the Srx-Prx system in tumor progression and metastasis. This enhanced understanding of molecular aspects of Srx-Prx interaction and its role in cell signal transduction will help define the Srx-Prx system as a future therapeutic target in human cancer.
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Transformação Celular Neoplásica/metabolismo , Metástase Neoplásica/fisiopatologia , Oxirredutases atuantes sobre Doadores de Grupo Enxofre/metabolismo , Peroxirredoxinas/metabolismo , Transdução de Sinais/fisiologia , Animais , Antioxidantes/metabolismo , Progressão da Doença , Glutationa/metabolismo , Humanos , Chaperonas Moleculares/metabolismo , Oxirredução , Oxirredutases/metabolismo , Especificidade por SubstratoRESUMO
UNLABELLED: Sulfiredoxin (SRXN1/Srx) is a multifunction enzyme with a primary antioxidant role of reducing the overoxidized inactive form of peroxiredoxins (Prxs). The function and mechanisms of Srx in cancer development are not well understood. Here, Srx is preferentially expressed in human colorectal cancer cells but not in normal colon epithelial cells. Loss-of-function studies demonstrate that knockdown of Srx in poorly differentiated colorectal cancer cells not only leads to the inhibition of colony formation and cell invasion in vitro, but also reduces tumor xenograft growth and represses metastasis to distal organs in a mouse orthotopic implantation model. Notably, exactly opposite effects were observed in gain-of-function experiments when Srx was ectopically expressed in well-differentiated colorectal cancer cells. Mechanistically, expression of Srx enhances the activation of MAPK signaling through increasing the C-terminal tyrosine phosphorylation levels of EGFR. This function of Srx is mediated through its inhibition of EGFR acetylation at K1037, a novel posttranslational modification of EGFR in human colorectal cancer cells identified by liquid chromatography-electrospray ionization-tandem mass spectrometry (LC/ESI/MS-MS) proteomic analysis. Furthermore, abolishment of K1037 acetylation in human colorectal cancer cells by site-specific mutagenesis leads to sustained activation of EGFR-MAPK signaling. Combined, these data reveal that Srx promotes colorectal cancer cell invasion and metastasis through a novel mechanism of enhancing EGFR signaling. IMPLICATIONS: Sulfiredoxin is a critical oncogenic protein that can be used as a molecular target to develop therapeutics for patients with metastatic colorectal cancer.
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Neoplasias Colorretais/enzimologia , Receptores ErbB/metabolismo , Sistema de Sinalização das MAP Quinases , Oxirredutases atuantes sobre Doadores de Grupo Enxofre/metabolismo , Acetilação , Animais , Linhagem Celular Tumoral , Movimento Celular , Regulação Neoplásica da Expressão Gênica , Células HCT116 , Células HT29 , Humanos , Camundongos , Invasividade Neoplásica , Metástase Neoplásica , Transplante de Neoplasias , FosforilaçãoRESUMO
Mounting evidence suggests that long-term aluminum exposure results in severe toxic effects, including neurobehavioral and neurochemical anomalies. The present study was performed to examine the neuroprotective potential of hesperidin and silibinin against aluminum chloride (AlCl3)-induced neurotoxicity in mice. AlCl3 (100 mg/kg/day) was injected daily through oral gavage for 42 days. Concomitantly, hesperidin (50 and 100 mg/kg/day, p.o.) and silibinin (100 and 200 mg/kg/day, p.o.) was administered for 42 days in different groups. The extent of cognitive impairment was assessed by Morris water maze and novel object recognition test on the 43rd day. Neurotoxicity was assessed by measuring oxido-nitrosative stress and proinflammatory cytokines in the hippocampus of mice. Six weeks treatment with AlCl3 caused cognitive impairment as indicated by an increase in the retention latency time and reduction in the percentage of recognition index. AlCl3-treated group showed oxido-nitrosative stress as indicated by increase in the level of lipid peroxidation, nitrite and depleted reduced glutathione, catalase activity in the hippocampus. Moreover, the chronic AlCl3 administration raised the proinflammatory cytokines (interleukin-1ß and tumor necrosis factor-α) level and increased acetylcholinesterase activity and reduced the BDNF content in the hippocampus of AlCl3-treated animals. However, chronic treatment with hesperidin and silibinin at higher doses significantly ameliorated the AlCl3-induced cognitive impairment and hippocampal biochemical anomalies. The present study clearly indicated that hesperidin and silibinin exert neuroprotective effects against AlCl3-induced cognitive impairment and neurochemical changes. Amelioration of cognitive impairment may be attributed to the impediment of oxido-nitrosative stress and inflammation in the hippocampus.
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Alumínio/toxicidade , Antioxidantes/metabolismo , Citocinas/metabolismo , Hesperidina/química , Hipocampo/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Silimarina/química , Animais , Comportamento Animal , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Catalase/metabolismo , Transtornos Cognitivos/tratamento farmacológico , Glutationa/metabolismo , Hipocampo/enzimologia , Inflamação/metabolismo , Interleucina-1beta/metabolismo , Peroxidação de Lipídeos , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Camundongos , Fármacos Neuroprotetores/farmacologia , Síndromes Neurotóxicas/tratamento farmacológico , Nitrogênio/metabolismo , Estresse Oxidativo , Silibina , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Members of the Peroxiredoxin (Prx) family are major cellular antioxidants that scavenge hydrogen peroxide and play essential roles in oxidative stress and cell signaling. 2-Cys Prxs, including Prx1, 2, 3 and 4, have been indicated in multiple oncogenic signaling pathways and thus may contribute to various processes of cancer development. The significance of 2-Cys Prxs in lung cancer development and their biological function in signal transduction have not been fully investigated. In this study we analyzed the expression of 2-Cys Prxs in lung cancer, and examined their levels of expression in a variety of cell lines established from human lung normal or cancer tissues. We found that 2-Cys Prxs, in particular, Prx1 and Prx4, were preferentially expressed in cell lines derived from human lung cancer. Through isoform specific knockdown of individual Prx, we demonstrated that Prx1 and Prx4 (but not Prx3) were required for human lung cancer A549 cells to form soft agar colony and to invade through matrigel in culture. Knockdown of Prx1 or Prx4 significantly reduced the activation of c-Jun and repressed the AP-1 mediated promoter activity. In mouse xenograft models, knockdown of Prx4 in A549 cells reduced subcutaneous tumor growth and blocked metastasis formation initiated through tail vein injection. Moreover, overexpression of Prx1 or Prx4 further enhanced the malignancy of A549 cells both in culture and in mouse xenografts in vivo. These data provide an in-depth understanding of the contribution of Prx1 and Prx4 to lung cancer development and are of importance for future development of therapeutic methods that targeting 2-Cys Prxs.