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1.
Mol Biol Rep ; 50(10): 8551-8563, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37644370

RESUMO

BACKGROUND: Liver cancer is the third leading cause of cancer-related deaths worldwide, and hepatocellular carcinoma (HCC) is the most common type of liver cancer. Transarterial interventions are among the chemotherapeutic approaches used in hardly operable regions prior to transplantation, and in electrochemotherapy, where doxorubicin is used. However, the efficacy of treatment is affected by resistance mechanisms. Previously, we showed that overexpression of the CUE5 gene results in doxorubicin resistance in Saccharomyces cerevisiae (S. cerevisiae). In this study, the effect of Toll-interacting protein (TOLLIP), the human ortholog of CUE5, on doxorubicin resistance was evaluated in HCC cells to identify its possible role in increasing the efficacy of transarterial interventions. METHODS AND RESULTS: The NIH Gene Expression Omnibus (GEO) and Oncomine datasets were analyzed for HCC cell lines with relatively low and high TOLLIP expression, and SNU449 and Hep3B cell lines were chosen, respectively. TOLLIP expression was increased by plasmid transfection and decreased by TOLLIP-siRNA in both cell lines and evaluated by RT-PCR and ELISA. Cell proliferation and viability were examined using xCELLigence and MTT assays after doxorubicin treatment, and growth inhibitory 50 (GI 50) concentrations were evaluated. Doxorubicin GI 50 concentrations decreased approximately 2-folds in both cell lines upon silencing TOLLIP after 48 h of drug treatment. CONCLUSIONS: Our results showed for the first time that silencing TOLLIP in hepatocellular carcinoma cells may help sensitize these cells to doxorubicin and increase the efficacy of chemotherapeutic regimens where doxorubicin is used.


Assuntos
Carcinoma Hepatocelular , Peptídeos e Proteínas de Sinalização Intracelular , Neoplasias Hepáticas , Humanos , Apoptose , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Linhagem Celular Tumoral , Doxorrubicina/farmacologia , Doxorrubicina/uso terapêutico , Resistencia a Medicamentos Antineoplásicos/genética , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Saccharomyces cerevisiae , Peptídeos e Proteínas de Sinalização Intracelular/genética
2.
J Pers Med ; 12(12)2022 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-36556285

RESUMO

Elevated levels of STIM1, an endoplasmic reticulum Ca2+ sensor/buffering protein, appear to be correlated with poor cancer prognosis in which microRNAs are also known to play critical roles. The purpose of this study is to investigate possible HBV origins of specific microRNAs we identified in a stem cell-like subpopulation of Huh-7 hepatocellular carcinoma (HCC) cell lines with enhanced STIM1 and/or Orai1 expression that mimicked poor cancer prognosis. Computational strategies including phylogenetic analyses were performed on miRNome data we obtained from an EpCAM- and CD133-expressing Huh-7 HCC stem cell-like subpopulation with enhanced STIM1 and/or Orai1 expression originally cultured in the present work. Results revealed two putative regions in the HBV genome based on the apparent clustering pattern of stem loop sequences of microRNAs, including miR3653. Reciprocal analysis of these regions identified critical human genes, of which their transcripts are among the predicted targets of miR3653, which was increased significantly by STIM1 or Orai1 enhancement. Briefly, this study provides phylogenetic evidence for a possible HBV-driven epigenetic remodeling that alters the expression pattern of Ca2+ homeostasis-associated genes in STIM1- or Orai1 overexpressing liver cancer stem-like cells for a possible mutual survival outcome. A novel region on HBV-X protein may affect liver carcinogenesis in a genotype-dependent manner. Therefore, detection of the viral genotype would have a clinical impact on prognosis of HBV-induced liver cancers.

3.
Mikrobiyol Bul ; 55(3): 311-326, 2021 Jul.
Artigo em Turco | MEDLINE | ID: mdl-34416799

RESUMO

The SARS-CoV-2 virus, which caused the COVID-19 epidemic, caused more than 55 million cases and nearly 1.5 million deaths worldwide. For the microbiological diagnosis of the disease, the most valid method is detecting the presence of the viral genome by real-time reverse transcription polymerase chain reaction (rRT-PCR). However, due to the nature of the RNA viruses, frequent mutations may affect the sensitivity of the analyses made on the genetic material of the virus, such as PCR. In this study, we aimed to investigate the mutations in the primer-probe binding regions of the rRT-PCR panels used in COVID-19 diagnosis. SARS-CoV-2 whole genome sequence data (n= 194) isolated from COVID-19 cases in Turkey and uploaded on GISAID database from the centers in Istanbul (n= 78), Ankara (n= 58), Kars (n= 47), Bursa (n= 2), Adiyaman (n= 2), Erciyes (n= 1) and Kocaeli (n= 1) between March 17-September 14, 2020 were analyzed. In order to determine the nucleotide changes, SARS-CoV-2 sequences from Turkey were compared to the reference genome sequence (NC_045512.1) present in "GenBank" website. The constructed data set was aligned using the MAFFT program and was checked manually if the sequences were in the same frame by using the AliView program. Primer-probe binding sites of the thirteen SARS-CoV-2 rRT-PCR panels from seven different institutes (US CDC, China CDC, Charite CDC, Pasteur, HKU, Thailand, NIID) that are being used in COVID-19 diagnosis were evaluated in terms of nucleotide changes within the corresponding regions compared to the reference genome. Sequence diversities in the viral genomes were determined via positional nucleotide numerical calculator and entropy calculator modules and nucleotide and entropy changes in primer-probe binding regions for each rRT-PCR panel were examined. Among thirteen different primer-probe panels, nucleotide changes in the target regions of the seven primer-probe panels were determined. When viral sequences with nucleotide changes in the primer-probe binding regions were examined, the most common changes were observed in the "China CDC" N-forward primer and "US CDC" N3-forward primer binding regions. It is important that the kits to be used as diagnostic tests are designed specific to the regions with less nucleotide changes. Nucleotide changes may not be critical for DNA amplification for most PCR panels, but should be carefully monitored as they may affect the sensitivity of the assay. If the risk of alteration of the designed region is high, the primer - probe binding sites should be checked frequently and updated when necessary.


Assuntos
COVID-19 , SARS-CoV-2 , Teste para COVID-19 , Humanos , Nucleotídeos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sensibilidade e Especificidade , Turquia
4.
Chemotherapy ; 66(1-2): 33-37, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33735872

RESUMO

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an enveloped virus initially detected in Wuhan in December 2019, responsible for coronavirus disease 2019 (COVID-19), a respiratory syndrome currently affecting >220 countries around the world, with >80 million cases registered and >1.8 million deaths. OBJECTIVE: As several vaccines are still being developed and 2 have been approved, it is particularly important to perform evolutionary surveillance to identify mutations potentially affecting vaccine efficacy. METHODS: DynaMut server has been used to evaluate the impact of the mutation found on SARS-CoV-2 isolates available on GISAID. RESULTS: In this article, we analyze whole genomes sequenced from Italian patients, and we report the characterization of 3 mutations, one of which presents in the spike protein. CONCLUSION: The mutations analyzed in this article can be useful to evaluate the evolution of SARS-CoV-2.


Assuntos
COVID-19 , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus/genética , COVID-19/diagnóstico , COVID-19/epidemiologia , COVID-19/virologia , Monitoramento Epidemiológico , Humanos , Itália/epidemiologia , Mutação , SARS-CoV-2/genética , SARS-CoV-2/isolamento & purificação , Sequenciamento Completo do Genoma/métodos
5.
J Med Virol ; 92(10): 2232-2237, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32492183

RESUMO

Italy is the first western country suffering heavy severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission and disease impact after coronavirus disease-2019 pandemia started in China. Even though the presence of mutations on spike glycoprotein and nucleocapsid in Italian isolates has been reported, the potential impact of these mutations on viral transmission has not been evaluated. We have compared SARS-CoV-2 genome sequences from Italian patients with virus sequences from Chinese patients. We focussed upon three nonsynonymous mutations of genes coding for S(one) and N (two) viral proteins present in Italian isolates and absent in Chinese ones, using various bioinformatics tools. Amino acid analysis and changes in three-dimensional protein structure suggests the mutations reduce protein stability and, particularly for S1 mutation, the enhanced torsional ability of the molecule could favor virus binding to cell receptor(s). This theoretical interpretation awaits experimental and clinical confirmation.


Assuntos
COVID-19/epidemiologia , COVID-19/transmissão , Proteínas do Nucleocapsídeo de Coronavírus/química , Genoma Viral , Pandemias , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/química , Substituição de Aminoácidos , COVID-19/patologia , COVID-19/virologia , China/epidemiologia , Proteínas do Nucleocapsídeo de Coronavírus/genética , Evolução Molecular , Humanos , Itália/epidemiologia , Modelos Moleculares , Epidemiologia Molecular , Mutação , Fosfoproteínas/química , Fosfoproteínas/genética , Filogenia , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , SARS-CoV-2/classificação , Índice de Gravidade de Doença , Glicoproteína da Espícula de Coronavírus/genética , Viagem , Replicação Viral
6.
J Infect Dev Ctries ; 14(5): 454-462, 2020 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-32525831

RESUMO

INTRODUCTION: North Africa has become a key migratory hub where a large number of migrants attempt the journey by sea from the Libyan coastline to the south of Europe. In this humanitarian disaster scenario, the Mediterranean route has been one of the most used by illegal boats. METHODOLOGY: In this report, the state of physical and psychological health of a cluster of Eritrean migrants, escaped from Libya and rescued in the Mediterranean Sea after a shipwreck, was described by epidemiological, clinical and laboratory investigations. RESULTS: Data suggest that despite the majority  of the migrants being apparently in good health upon a syndromic surveillance approach, most of them suffered a decline in psychological status as well as severe malnutrition. The emergence of infectious diseases, related to poor living conditions during the journey, is not a rare event. CONCLUSION: The present report highlights the risks of failures of the syndromic medical approach in the setting of the extremely challenging migration route and underlines migrant frailties consequent to a prolonged journey and long period of detention. These stressors, which can degrade the initial health condition of traveling migrants, can lead to a premature "exhausted migrant effect" that should be carefully investigated in order to avoid the early emergence of diseases related to frailty.


Assuntos
Controle de Doenças Transmissíveis/estatística & dados numéricos , Desnutrição/etiologia , Refugiados/psicologia , Migrantes/psicologia , Criança , Controle de Doenças Transmissíveis/métodos , Doenças Transmissíveis/epidemiologia , Eritreia , Europa (Continente)/epidemiologia , Feminino , Humanos , Líbia , Masculino , Desnutrição/epidemiologia , Programas de Rastreamento , Mar Mediterrâneo , Refugiados/estatística & dados numéricos , Trabalho de Resgate , Migrantes/estatística & dados numéricos
7.
Turk J Biol ; 44(3): 178-184, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32595354

RESUMO

A previously unknown coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been shown to cause coronavirus disease 2019 (COVID-19) pandemic. The first case of COVID-19 in Turkey has been declared in March 11th, 2020 and from there on, more than 150,000 people in the country have been diagnosed with the disease. In this study, 62 viral sequences from Turkey, which have been uploaded to GISAID database, were analyzed by means of their nucleotide substitutions in comparison to the reference SARS-CoV-2 genome from Wuhan. Our results indicate that the viral isolates from Turkey harbor some common mutations with the viral strains from Europe, Oceania, North America and Asia. When the mutations were evaluated, C3037T, C14408T and A23403G were found to be the most common nucleotide substitutions among the viral isolates in Turkey, which are mostly seen as linked mutations and are part of a haplotype observed high in Europe.

8.
Urol Oncol ; 38(5): 476-487, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32192892

RESUMO

OBJECTIVE: Bladder cancer is characterized by frequent recurrence and progression. CD44+ cancer stem cells (CSCs) might be one of the main reasons for recurrence. Although Bacillus Calmette Guerin (BCG) has become a gold standard immunotherapy, after treatment recurrence frequently occur. Based on this knowledge, the aim of this study was to evaluate the changes in cytokine and chemokine expressions in bladder cancer and CSCs cultures in vitro with BCG only and in combination with IL2 and lymphocyte (MNCs) applications. MATERIAL AND METHODS: In this study, 3 cell lines of human bladder cancer cells with different characteristics (T24, 5637, and JMSU-1) and CD44+ bladder CSCs isolated by magnetic bead isolation (Miltenyl Magtech) were used. Bladder cancer cell lines and bladder CSCs in complete medium were cultured under humidified conditions of 37°C temperature in 5% CO2. BCG only and its combination with IL2 and MNCs were applied to bladder cancer cell lines and bladder CSCs for 24, 48, and 72 hours. Annexin V-PI was used to detect the percentages of apoptotic and necrotic cells in treatment groups and control groups. After treatments, total RNAs were isolated and converted to cDNA for each group and controls. Quantitative fold changes in terms of gene expression were measured by RT2-PCR array and fold changes for expression levels of genes were compared among groups. Eighty-four genes were analyzed in standard array of chemokines and cytokines (Biorad). RESULTS: BCG treatment with 7.32 µg/ml dose alone and in combination with IL2 (1000 IU/ml) and MNCs (1000 cells/ml) were found to be most effective on bladder cancer cells. When BCG and its combinations were applied to CSCs of the 3 cell lines, BCG treatment showed cytotoxic effect on CSCs as well as cancer cells. CSCs of 3 cell lines over expressed CXCL5, CCL8, CNTF, and CSF2 compared with cancer cells. Cancer cells over expressed IL6, TNSFF11, FASLG, and CXCL9 compared with CSCs. In all 3 cell lines, BCG application increased expression of CXCL5 and LTB and also decreased CCL20 and IL6. When BCG was combined with IL2 and MNCs, CXCL10, CXCL5, and IFNG were increased and CXCL12, IL6, and TNSF11 were decreased. BCG treatment of CSCs caused increases in ADIPOQ, CXCL10, and XCL1 and a decrease in CCL8. When IL2 and MNCs were combined with BCG, the expression of many cytokines and chemokines decreased. CONCLUSION: BCG treatment changes the expression of many cytokines and chemokines in bladder cancer. The expression differs in 3 different cell lines and their CSCs. Immune modulation of each case differs from each other. The effectivity of BCG-based immunotherapy in bladder cancer on CSCs might decrease in combination with IL2. Our results indicate that recurrence after BCG treatment for bladder cancer may not occur mainly based on the CSCs hypothesis considering bladder cancer occurs at different loci of surface epithelium.


Assuntos
Quimiocinas/biossíntese , Citocinas/biossíntese , Imunoterapia , Células-Tronco Neoplásicas/fisiologia , Neoplasias da Bexiga Urinária/metabolismo , Neoplasias da Bexiga Urinária/terapia , Adjuvantes Imunológicos/administração & dosagem , Adjuvantes Imunológicos/farmacologia , Idoso , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacologia , Vacina BCG/administração & dosagem , Vacina BCG/farmacologia , Linhagem Celular Tumoral , Humanos , Interleucina-2/administração & dosagem , Interleucina-2/farmacologia , Linfócitos , Masculino , Pessoa de Meia-Idade , Células-Tronco Neoplásicas/efeitos dos fármacos , Neoplasias da Bexiga Urinária/imunologia
10.
J Pediatr Hematol Oncol ; 41(1): 7-12, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-29889802

RESUMO

Hepatoblastoma (HB) is the most common liver malignancy in children. The prognosis changes according to the histologic subtypes of HB. In the present study, we aimed to characterize the expression level of selected microRNAs (miRNAs) in HB as well as in histologic subtypes, and to consider the association with the prognosis. A total of 22 HB tumor samples, subtyped as fetal (n=16) and embryonal (n=6), and 10 nontumorous surrounding liver samples were evaluated in this study. Expressions of miR-17, miR-146a, miR-302d, and miR-19b were analyzed in 22 HB tumor samples and 10 nontumorous surrounding liver samples by quantitative real-time polymerase chain reaction. Lower miRNA-17 expression levels were obtained in tumor samples in comparison with nontumorous surrounding liver samples (P=0.028). Lower miRNA-17 expression was significant for predicting prognosis in HB patients (area under receiver-operator characteristic curve=0.875, P=0.044). A higher-level of miR-19b was found in embryonal samples (P=0.008). Overall and event-free survival was not found to correlate with miRNA expression levels (P>0.05). This research finds miRNA-17 and miRNA-19b expression levels can provide important data on diagnosis and prognosis in HB showing different clinical behaviors.


Assuntos
Regulação Neoplásica da Expressão Gênica , Hepatoblastoma , Neoplasias Hepáticas , MicroRNAs/biossíntese , RNA Neoplásico/biossíntese , Adolescente , Adulto , Criança , Pré-Escolar , Intervalo Livre de Doença , Feminino , Hepatoblastoma/metabolismo , Hepatoblastoma/mortalidade , Humanos , Lactente , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/mortalidade , Masculino , Reação em Cadeia da Polimerase em Tempo Real , Taxa de Sobrevida
11.
Turk J Obstet Gynecol ; 15(4): 273-276, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30693145

RESUMO

Peters plus syndrome is a rare congenital disorder that includes ocular anterior segment defects of the classic Peter's anomaly, and is mostly associated with craniofacial and skeletal defects. A 21-week fetus was referred for further evaluation due to a suspicion of fetal hydrocephalus. An ultrasound examination revealed hyperechogenic lenses, microphthalmia, hypotelorism, retrognathia, mild ventriculomegaly, absence of the cavum septum pellucidum, and short stature. Amniocentesis and further microarray analysis revealed normal chromosomal copy numbers including the gene B3GALTL. In utero mort fetalis occurred at the 23rd gestational week. Ultrasound and fetal autopsy findings were suggestive of Peters plus syndrome, but the absence of the B3GALTL gene mutation made the diagnosis Peters plus-like syndrome. Obstetricians should consider Peters plus-like syndrome with prenatal detection of ocular anomalies along with craniofacial and skeletal anomalies with the absence of B3GALTL gene mutation.

12.
Medicine (Baltimore) ; 96(6): e5903, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28178129

RESUMO

BACKGROUND: Lung cancer is responsible of 12.4% and 17.6% of all newly diagnosed cancer cases and mortality due to cancer, respectively, and 5-year survival rate despite all improved treatment options is 15%. This survival rate reaches 66% in the Stage 1 and surgically treated patients. Early diagnosis which could not be definitely and commonly achieved yet is extremely critical in obtaining high survival rate in this disease. For this reason; proteomic differences were evaluated using matrix assisted laser desorption ionization (MALDI) mass spectrometry in the subgroups of lung adenocarcinoma and squamous cell carcinoma. METHODS: Fresh tissue samples of 36 malignant cases involving 83.3% (n = 30) men and 16.7% (n = 6) women patients were distributed into 2 groups as early and end stage lung cancer and each group were composed of subgroups including 18 squamous cell carcinoma (9 early stage cases, 9 end stage cases) and 18 adenocarcinoma cases (9 early stage cases, 9 end stage cases). The fresh tissues obtained from the tumoral and matched normal sites after surgical intervention. The differences in protein expression levels were determined by comparing proteomic changes in each patient. RESULTS: In the subgroups of advanced stage adenocarcinoma; tumoral tissue revealed differences in expression of 2 proteins compared with normal parenchymal tissue. Of those; difference in protein expression in heat shock protein 60 (HSP60) was found statistically significant (P = 0.0001). Subgroups of early and advanced stage squamos cell carcinoma have differed in certain 20 protein expression of normal tissue and diseased squamos cell carcinoma. Of those, increased protein expression level of only annexin-2 protein was found statistically significant (P = 0.002). No significant difference was detected in early and advanced stage protein expressions of the tumoral tissues in the subgroups of adenocarcinoma and squamous cell carcinoma. CONCLUSIONS: We conclude that with respect to early diagnosis of lung cancer that HSP60 and annexin-2 proteins are the important biomarkers in the subgroups of adenocarcinoma and squamous cell carcinoma. We also consider that these 2 proteins are molecules which may provide critical contribution in evaluation of prognosis, metastatic potential, response to treatment, and in establishment of differential diagnosis between adenocarcinoma and squamous cell carcinoma.


Assuntos
Anexina A2/metabolismo , Biomarcadores Tumorais/metabolismo , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Chaperonina 60/metabolismo , Neoplasias Pulmonares/metabolismo , Proteínas Mitocondriais/metabolismo , Idoso , Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Diagnóstico Precoce , Feminino , Humanos , Neoplasias Pulmonares/diagnóstico , Masculino , Pessoa de Meia-Idade , Proteoma , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
13.
PLoS One ; 10(12): e0145108, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26690737

RESUMO

Doxorubicin is one of the most potent anticancer drugs used in the treatment of various cancer types. The efficacy of doxorubicin is influenced by the drug resistance mechanisms and its cytotoxicity. In this study, we performed a high-copy screening analysis to find genes that play a role in doxorubicin resistance and found several genes (CUE5, AKL1, CAN1, YHR177W and PDR5) that provide resistance. Among these genes, overexpression of PDR5 provided a remarkable resistance, and deletion of it significantly rendered the tolerance level for the drug. Q-PCR analyses suggested that transcriptional regulation of these genes was not dependent on doxorubicin treatment. Additionally, we profiled the global expression pattern of cells in response to doxorubicin treatment and highlighted the genes and pathways that are important in doxorubicin tolerance/toxicity. Our results suggest that many efflux pumps and DNA metabolism genes are upregulated by the drug and required for doxorubicin tolerance.


Assuntos
Transportadores de Cassetes de Ligação de ATP/biossíntese , Doxorrubicina/farmacologia , Farmacorresistência Fúngica/fisiologia , Regulação Fúngica da Expressão Gênica/efeitos dos fármacos , Proteínas de Saccharomyces cerevisiae/biossíntese , Saccharomyces cerevisiae/metabolismo , Transportadores de Cassetes de Ligação de ATP/genética , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética
14.
Int J Cell Biol ; 2014: 913071, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24639875

RESUMO

Calorie restriction (CR) is an intervention extending the life spans of many organisms. The mechanisms underlying CR-dependent retardation of aging are still poorly understood. Despite mechanisms involving conserved nutrient signaling pathways proposed, few target processes that can account for CR-mediated longevity have so far been identified. Recently, both peroxiredoxins and vacuolar-ATPases were reported to control CR-mediated retardation of aging downstream of conserved nutrient signaling pathways. In this review, we focus on peroxiredoxin-mediated stress-defence and vacuolar-ATPase regulated acidification and pinpoint common denominators between the two mechanisms proposed for how CR extends life span. Both the activities of peroxiredoxins and vacuolar-ATPases are stimulated upon CR through reduced activities in conserved nutrient signaling pathways and both seem to stimulate cellular resistance to peroxide-stress. However, whereas vacuolar-ATPases have recently been suggested to control both Ras-cAMP-PKA- and TORC1-mediated nutrient signaling, neither the physiological benefits of a proposed role for peroxiredoxins in H2O2-signaling nor downstream targets regulated are known. Both peroxiredoxins and vacuolar-ATPases do, however, impinge on mitochondrial iron-metabolism and further characterization of their impact on iron homeostasis and peroxide-resistance might therefore increase our understanding of the beneficial effects of CR on aging and age-related diseases.

15.
Exp Gerontol ; 47(2): 149-53, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22137892

RESUMO

Aging is the progressive accumulation of alterations in cells that elevates the risk of death. The mitochondrial theory of aging postulates that free radicals produced by the mitochondrial respiratory system contribute to the aging process. However, the roles of individual electron transfer chain (ETC) components in cellular aging have not been elucidated. In this study, we analyzed the replicative life span of 73 yeast deletion mutants lacking the genes of the mitochondrial electron transfer chain system, and found that nine of these mutants (Δnde1, Δtcm62, Δrip1, Δcyt1, Δqrc8, Δpet117, Δcox11, Δatp11, Δfmc1) had significantly shorter life spans. These mutants had lower rates of respiration and were slightly sensitive to exogenous administration of hydrogen peroxide. However, only two of them, Δnde1 and Δfmc1, produced higher amounts of intrinsic superoxide radicals in the presence of glucose compared to that of wild type cells. Interestingly, there were no significant alterations in the mitochondrial membrane potentials of these mutants. We speculate that the shorter life spans of ETC mutants result from multiple mechanisms including the low respiration rate and low energy production rather than just a ROS-dependent path.


Assuntos
Respiração Celular , Senescência Celular/genética , Transporte de Elétrons/genética , Deleção de Genes , Longevidade/genética , Reprodução , Saccharomyces cerevisiae/genética , Respiração Celular/genética , Potenciais da Membrana/genética , Membranas Mitocondriais/metabolismo , Consumo de Oxigênio/genética , Espécies Reativas de Oxigênio/metabolismo , Superóxidos/metabolismo
16.
Biochem Biophys Res Commun ; 400(1): 106-10, 2010 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-20707985

RESUMO

The free radical theory of aging states that oxidative damage to biomolecules causes aging and that antioxidants neutralize free radicals and thus decelerate aging. Mitochondria produce most of the reactive oxygen species, but at the same time have many antioxidant enzymes providing protection from these oxidants. Expecting that cells without mitochondrial antioxidant genes would accumulate higher levels of oxidative damage and, therefore, will have a shorter lifespan, we analyzed oxidative damages to biomolecules in young and chronologically aged mutants lacking the mitochondrial antioxidant genes: GRX2, CCP1, SOD1, GLO4, TRR2, TRX3, CCS1, SOD2, GRX5, and PRX1. Among these mutants, ccp1Δ, trx3Δ, grx5Δ, prx1Δ, mutants were sensitive to diamide, and ccs1Δ and sod2Δ were sensitive to both diamide and menadione. Most of the mutants were less viable in stationary phase. Chronologically aged cells produced higher amount of superoxide radical and accumulated higher levels of oxidative damages. Even though our results support the findings that old cells harbor higher amount of molecular damages, no significant difference was observed between wild type and mutant cells in terms of their damage content.


Assuntos
Senescência Celular/genética , Genes Mitocondriais , Estresse Oxidativo/genética , Saccharomyces cerevisiae/genética , Superóxidos/metabolismo , Diamida/farmacologia , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/metabolismo , Fatores de Tempo
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