Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Nutr Neurosci ; 25(5): 976-989, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-33034271

RESUMO

BACKGROUND: Early-life adversity impacts on the offspring's brain development and is associated with a higher risk of developing age-associated diseases. In particular, perinatal protein malnutrition appears to be one of the most critical nutritional deficiencies affecting the individual's health and survival, but little is known about its effects on the persistence of behavioral alterations throughout life. Thus, the aim of the present study was to investigate how perinatal protein malnutrition impacts on age-related changes in the neuromuscular, cognitive and behavioral functions throughout life in a mouse model. METHODS: One group of CF-1 dams received a normal-protein diet (NP: 20% casein) during gestation and lactation, whereas another group received a low-protein diet (LP: 10% casein). The offspring of both groups were analyzed by means of several behavioral tests at four different ages (young: 6-10 weeks old, mature: 22-26 weeks old, middle age: 39-43 weeks old, and old: 55-59 weeks old). RESULTS: Regarding neuromuscular functions, LP mice showed an early deterioration in muscular strength and a reduction in the body weight throughout life. Regarding behavior, while NP mice showed an age-related reduction of exploratory behavior, LP mice showed a constantly low level of this behavior, as well as high anxiety-like behavior, which remained at high levels throughout life. Regarding cognitive functions, LP mice showed deteriorated working memory at middle age. Finally, LP mice died 3.4 times earlier than NP mice. Analysis of the sex-related vulnerability showed that females and males were equally affected by perinatal protein malnutrition throughout life. CONCLUSION: Our results demonstrate that perinatal protein malnutrition induces enduring and age-related impairment behaviors, which culminate in higher death risk, affecting males and females equally.


Assuntos
Desnutrição , Efeitos Tardios da Exposição Pré-Natal , Animais , Caseínas , Dieta com Restrição de Proteínas/efeitos adversos , Modelos Animais de Doenças , Feminino , Humanos , Lactação , Masculino , Desnutrição/complicações , Desnutrição/metabolismo , Fenômenos Fisiológicos da Nutrição Materna , Camundongos , Gravidez , Efeitos Tardios da Exposição Pré-Natal/metabolismo
2.
N Z Med J ; 133(1526): 55-66, 2020 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-33332340

RESUMO

AIM: This retrospective review examined the influence of age and severity of comorbidities on goals-of-care in advance care plans (ACPlans) and concordance between these wishes and care received during hospital admission. METHODS: The medical records of 149 people with an ACPlan admitted to a public hospital were reviewed to evaluate concordance with treatment. The associations between age and comorbidities and goals-of-care were determined using contingency tables and logistic regression analyses. RESULTS: The majority of the review cohort were Caucasian and elderly, with people from minority ethnic groups under-represented compared to census data. Increasing age had a measurable influence on the choice of goal-of-care, whereas comorbidity severity had less influence on this decision. In 60 of the 411 hospital admissions the patient was classified as incompetent, with the goal-of-care adhered to in 59 of these cases and treatment preferences adhered to in six of seven cases. Fifty-five people had died since writing their ACPlan, with 63% dying at their preferred place or with no preference stated. CONCLUSIONS: Age and to a lesser extent the severity of comorbidities influence the choice of goal-of-care in an ACPlan. Our review also showed that end-of-life care appeared to adhere to the instructions in the plan.


Assuntos
Planejamento Antecipado de Cuidados/organização & administração , Hospitalização/tendências , Hospitais Públicos/estatística & dados numéricos , Prontuários Médicos/estatística & dados numéricos , Preferência do Paciente , Assistência Terminal/organização & administração , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Nova Zelândia , Estudos Retrospectivos
3.
Nutr Neurosci ; 23(5): 387-397, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-30124115

RESUMO

Objectives: Early life represents a sensitive and critical period for an individual. Nutrition plays a crucial role in the maturation and functional development of the central nervous system. Inadequate nutrition before birth and during the postnatal life can seriously interfere with brain development and lead to behavioral and neurological disorders such as learning disabilities and psychiatric diseases. In addition, the quality of mother-infant interactions represents an important adaptive pathway that prepares offspring for the conditions of life. In this work, we asked if protein malnutrition alters maternal care and offspring development and if these phenotypes can be transmitted to next generation.Methods: Female mice were fed with a normal or hypoproteic diet during pregnancy and lactation. Nurturing behaviors, i.e. arched, blanket and passive nursing, and liking and grooming of the pups, were evaluated from postnatal day 1 (PD1) to postnatal day 7 (PD7). The same protocol was employed to evaluate maternal behavior for filial generation 1 (F1) and filial generation 2 (F2) dams. Offspring development was evaluated for F1, F2, and F3 generations. Developmental landmarks and neurological reflexes were assessed from PD8 until complete development of the landmark or acquisition of the reflex.Results: Our results show that malnourished dams provide a lesser and more fragmented maternal care than their normally fed counterparts. This altered maternal behavior as well as the delay in the physical and neurological development observed in the offspring from malnourished mothers was transmitted up to two generations at least.Conclusion: These results highlight the harmful effects of protein malnutrition even for generations that are not directly exposed to this environmental adversity.


Assuntos
Desnutrição/fisiopatologia , Comportamento Materno , Fenômenos Fisiológicos da Nutrição Materna , Efeitos Tardios da Exposição Pré-Natal/fisiopatologia , Animais , Feminino , Masculino , Desnutrição/complicações , Camundongos , Estado Nutricional , Gravidez , Efeitos Tardios da Exposição Pré-Natal/etiologia
4.
Psychopharmacology (Berl) ; 236(12): 3525-3539, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31280332

RESUMO

RATIONALE: Cocaine base paste (CBP) is an illegal drug of abuse usually consumed by adolescents in a socio-economically vulnerable situation. Repeated drug use targets key brain circuits disrupting the processes that underlie emotions and cognition. At the basis of such neuroadaptations lie changes in the expression of immediate-early genes (IEGs). Nevertheless, changes in transcriptional regulation associated with CBP consumption remain unknown. OBJECTIVES: We aimed to describe behavioral phenotype related to locomotion, anxiety-like behavior, and memory of CBP-injected mice and to study IEGs expression after an abstinence period. METHODS: Five-week-old female CF-1 mice were i.p. injected daily with vehicle or CBP (40 mg/kg) for 10 days and subjected to a 10-day period of abstinence. Open field and novel object recognition tests were used to evaluate locomotion and anxiety-like behaviors and recognition memory, respectively, during chronic administration and after abstinence. After abstinence, prefrontal cortex (mPFC) and nucleus accumbens (NAc) were isolated and gene expression analysis performed through real-time PCR. RESULTS: We found an increase in locomotion and anxiety-like behavior during CBP administration and after the abstinence period. Furthermore, the CBP group showed impaired recognition memory after abstinence. Egr1, FosB, ΔFosB, Arc, Bdnf, and TrkB expression was upregulated in CBP-injected mice in NAc and FosB, ΔFosB, Arc, and Npas4 expression was downregulated in mPFC. We generated an anxiety score and found positive and negative correlations with IEGs expression in NAc and mPFC, respectively. CONCLUSION: Our results suggest that chronic CBP exposure induced alterations in anxiety-like behavior and recognition memory. These changes were accompanied by altered IEGs expression.


Assuntos
Ansiedade/induzido quimicamente , Ansiedade/metabolismo , Cocaína/administração & dosagem , Genes Precoces/fisiologia , Núcleo Accumbens/metabolismo , Córtex Pré-Frontal/metabolismo , Animais , Ansiedade/psicologia , Cocaína/toxicidade , Inibidores da Captação de Dopamina/administração & dosagem , Inibidores da Captação de Dopamina/toxicidade , Feminino , Regulação da Expressão Gênica , Genes Precoces/efeitos dos fármacos , Locomoção/efeitos dos fármacos , Locomoção/fisiologia , Camundongos , Núcleo Accumbens/efeitos dos fármacos , Córtex Pré-Frontal/efeitos dos fármacos
5.
BMJ Open ; 9(5): e025253, 2019 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-31061024

RESUMO

OBJECTIVES: In takotsubo syndrome, QTc prolongation is a measure of risk of potentially fatal arrhythmia. It is not known how this risk, or derangement of other markers, differs across the echo variants of takotsubo syndrome. Therefore, we sought to explore whether apical takotsubo syndrome differs from the variants of the syndrome in more ways than just regional wall motion pattern. As the region of affected myocardium is usually larger, we hypothesised that patients with the classic apical ballooning form of takotsubo syndrome would have more severe derangement of their markers. DESIGN: Observational study of patients gathered from a prospective database (2010-2018) and by retrospective review (2006-2009). SETTING: The sole tertiary hospital from a New Zealand region in which case clusters of takotsubo syndrome were precipitated by large earthquakes in 2010, 2011 and 2016. PARTICIPANTS: A total of 222 patients who met a modified version of the Mayo criteria for takotsubo syndrome were included. All patients had digitally archived echocardiograms that were over-read by a second echocardiologist blinded to the clinical report. PRIMARY OUTCOME MEASURES: Ejection fraction, peak troponin and QTc interval. RESULTS: Patients with the apical form were older (p=0.011), had a lower initial left ventricular ejection fraction (35% vs 44%, p<0.0001) and a higher peak high-sensitivity troponin I (hsTnI) (p=0.01) than those with variant forms. There was no difference in the electrical abnormalities between the variants (QTc interval, heart rate, PR interval, QRS duration or T-wave axis). There was also no correlation between any of peak hsTnI, peak QTc and ejection fraction. QTc interval increased on day 2 and peaked on day 3 before falling steeply (p<0.0001). CONCLUSIONS: The variants of takotsubo syndrome differ in more ways than just their echo pattern but do not differ in their electrical abnormalities. There is a dissociation between the structural and electrical abnormalities. QTc peaks on day 3 and then falls steeply.


Assuntos
Terremotos/estatística & dados numéricos , Ecocardiografia , Cardiomiopatia de Takotsubo/fisiopatologia , Troponina I/sangue , Idoso , Análise de Variância , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nova Zelândia/epidemiologia , Estudos Retrospectivos , Cardiomiopatia de Takotsubo/sangue , Cardiomiopatia de Takotsubo/epidemiologia , Centros de Atenção Terciária
6.
Neuropsychopharmacology ; 44(8): 1425-1434, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30867552

RESUMO

Contemporary neurocognitive models of drug addiction have associated this condition with changes in interoception -namely, the sensing and processing of body signals that fulfill homeostatic functions relevant for the onset and maintenance of addictive behavior. However, most previous evidence is inconsistent, behaviorally unspecific, and virtually null in terms of direct electrophysiological and multimodal markers. To circumvent these limitations, we conducted the first assessment of the relation between cardiac interoception and smoked cocaine dependence (SCD) in a sample of (a) 25 participants who fulfilled criteria for dependence on such a drug, (b) 22 participants addicted to insufflated clorhidrate cocaine (only for behavioral assessment), and (c) 25 healthy controls matched by age, gender, education, and socioeconomic status. We use a validated heartbeat-detection (HBD) task and measured modulations of the heart-evoked potential (HEP) during interoceptive accuracy and interoceptive learning conditions. We complemented this behavioral and electrophysiological data with offline structural (MRI) and functional connectivity (fMRI) analysis of the main interoceptive hubs. HBD and HEP results convergently showed that SCD subjects presented ongoing psychophysiological measures of enhanced interoceptive accuracy. This pattern was associated with a structural and functional tuning of interoceptive networks (reduced volume and specialized network segregation). Taken together, our findings provide the first evidence of an association between cardiac interoception and smoked cocaine, partially supporting models that propose hyper-interoception as a key aspect of addiction. More generally, our study shows that multimodal assessments of interoception could substantially inform the clinical and neurocognitive characterization of psychophysiological and neurocognitive adaptations triggered by addiction.


Assuntos
Transtornos Relacionados ao Uso de Cocaína/fisiopatologia , Potenciais Evocados/fisiologia , Interocepção/fisiologia , Vias Neurais/fisiopatologia , Administração por Inalação , Cocaína/administração & dosagem , Transtornos Relacionados ao Uso de Cocaína/psicologia , Endofenótipos , Feminino , Frequência Cardíaca/fisiologia , Humanos , Aprendizagem/fisiologia , Imageamento por Ressonância Magnética , Masculino , Neuroimagem , Adulto Jovem
7.
Aust N Z J Obstet Gynaecol ; 59(1): 82-88, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-29516471

RESUMO

BACKGROUND: On 22 February 2011 an earthquake (magnitude 6.3) hit Christchurch, New Zealand. Earthquakes have been associated with increased risks of preterm birth (PTB) and other adverse pregnancy outcomes. However, the literature on this subject is scarce. Maternal antenatal stress has been suggested as the link between earthquakes and PTB. In this study the Christchurch earthquake was utilised as a model of maternal stress to assess its effects on PTB rates and other pregnancy outcomes. AIM: To investigate whether women who experienced a major earthquake during the first trimester of pregnancy were at an altered risk of PTB compared to women who did not experience an earthquake during their pregnancy. METHODS: This was a retrospective cohort study. Women carrying a singleton pregnancy in their first trimester on 22 February, 2011 were identified for a post-earthquake cohort (n = 1057). A group of women pregnant in 2009 were identified for a pre-earthquake cohort (n = 1314). Data were obtained from electronic medical records and the hospital clinical coding database. Chi-square test, Fisher's exact test and Wilcoxon rank sum test were used to analyse differences in pregnancy outcomes. Statistically significant variables together with earthquake exposure were assessed as risk factors for PTB using a multivariate logistic regression model. RESULTS: No significant difference in the rate of PTB was found between the two groups P > 0.05). CONCLUSION: Women carrying a singleton pregnancy in this study who experienced a major earthquake in their first trimester do not seem to be at an increased risk of PTB.


Assuntos
Terremotos , Nascimento Prematuro/epidemiologia , Cuidado Pré-Natal , Adulto , Estudos de Coortes , Feminino , Humanos , Recém-Nascido , Nova Zelândia/epidemiologia , Gravidez , Primeiro Trimestre da Gravidez , Nascimento Prematuro/etiologia , Estudos Retrospectivos , Fatores de Risco
8.
Mol Cell Biochem ; 425(1-2): 9-24, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27816995

RESUMO

cAMP response element-binding (CREB) protein is a cellular transcription factor that mediates responses to different physiological and pathological signals. Using a model of human neuronal cells we demonstrate herein, that CREB is phosphorylated after oxidative stress induced by hydrogen peroxide. This phosphorylation is largely independent of PKA and of the canonical phosphoacceptor site at ser-133, and is accompanied by an upregulation of CREB expression at both mRNA and protein levels. In accordance with previous data, we show that CREB upregulation promotes cell survival and that its silencing results in an increment of apoptosis after oxidative stress. Interestingly, we also found that CREB promotes DNA repair after treatment with hydrogen peroxide. Using a cDNA microarray we found that CREB is responsible for the regulation of many genes involved in DNA repair and cell survival after oxidative injury. In summary, the neuroprotective effect mediated by CREB appears to follow three essential steps following oxidative injury. First, the upregulation of CREB expression that allows sufficient level of activated and phosphorylated protein is the primordial event that promotes the induction of genes of the DNA Damage Response. Then and when the DNA repair is effective, CREB induces detoxification and survival genes. This kinetics seems to be important to completely resolve oxidative-induced neuronal damages.


Assuntos
Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Dano ao DNA , Reparo do DNA , Neurônios/metabolismo , Estresse Oxidativo , Regulação para Cima , Morte Celular , Linhagem Celular Tumoral , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genética , Proteínas Quinases Dependentes de AMP Cíclico/genética , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Humanos , Fosforilação/genética
9.
Cell Cycle ; 14(8): 1300-14, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25892555

RESUMO

E2F transcription factors regulate a wide range of biological processes, including the cellular response to DNA damage. In the present study, we examined whether E2F family members are transcriptionally induced following treatment with several genotoxic agents, and have a role on the cell DNA damage response. We show a novel mechanism, conserved among diverse species, in which E2F1 and E2F2, the latter specifically in neuronal cells, are transcriptionally induced after DNA damage. This upregulation leads to increased E2F1 and E2F2 protein levels as a consequence of de novo protein synthesis. Ectopic expression of these E2Fs in neuronal cells reduces the level of DNA damage following genotoxic treatment, while ablation of E2F1 and E2F2 leads to the accumulation of DNA lesions and increased apoptotic response. Cell viability and DNA repair capability in response to DNA damage induction are also reduced by the E2F1 and E2F2 deficiencies. Finally, E2F1 and E2F2 accumulate at sites of oxidative and UV-induced DNA damage, and interact with γH2AX DNA repair factor. As previously reported for E2F1, E2F2 promotes Rad51 foci formation, interacts with GCN5 acetyltransferase and induces histone acetylation following genotoxic insult. The results presented here unveil a new mechanism involving E2F1 and E2F2 in the maintenance of genomic stability in response to DNA damage in neuronal cells.


Assuntos
Dano ao DNA , Fator de Transcrição E2F1/metabolismo , Fator de Transcrição E2F2/metabolismo , Instabilidade Genômica , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Cicloeximida/toxicidade , Dano ao DNA/efeitos dos fármacos , Dano ao DNA/efeitos da radiação , Reparo do DNA/efeitos dos fármacos , Dactinomicina/toxicidade , Fator de Transcrição E2F1/genética , Fator de Transcrição E2F2/genética , Instabilidade Genômica/efeitos dos fármacos , Instabilidade Genômica/efeitos da radiação , Células HEK293 , Histonas/metabolismo , Humanos , Peróxido de Hidrogênio/toxicidade , MAP Quinase Quinase Quinases/metabolismo , Neurônios/citologia , Neurônios/metabolismo , Inibidores da Síntese de Proteínas/toxicidade , Rad51 Recombinase/metabolismo , Raios Ultravioleta , Regulação para Cima/efeitos dos fármacos , Fatores de Transcrição de p300-CBP/metabolismo
10.
Biochim Biophys Acta ; 1843(7): 1309-24, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24703879

RESUMO

DNA damage, which perturbs genomic stability, has been linked to cognitive decline in the aging human brain, and mutations in DNA repair genes have neurological implications. Several studies have suggested that DNA damage is also increased in brain disorders such as Alzheimer's disease, Parkinson's disease and amyotrophic lateral sclerosis. However, the precise mechanisms connecting DNA damage with neurodegeneration remain poorly understood. CDK5, a critical enzyme in the development of the central nervous system, phosphorylates a number of synaptic proteins and regulates dendritic spine morphogenesis, synaptic plasticity and learning. In addition to these physiological roles, CDK5 has been involved in the neuronal death initiated by DNA damage. We hypothesized that p19INK4d, a member of the cell cycle inhibitor family INK4, is involved in a neuroprotective mechanism activated in response to DNA damage. We found that in response to genotoxic injury or increased levels of intracellular calcium, p19INK4d is transcriptionally induced and phosphorylated by CDK5 which provides it with greater stability in postmitotic neurons. p19INK4d expression improves DNA repair, decreases apoptosis and increases neuronal survival under conditions of genotoxic stress. Our in vivo experiments showed that decreased levels of p19INK4d rendered hippocampal neurons more sensitive to genotoxic insult resulting in the loss of cognitive abilities that rely on the integrity of this brain structure. We propose a feedback mechanism by which the neurotoxic effects of CDK5-p25 activated by genotoxic stress or abnormal intracellular calcium levels are counteracted by the induction and stabilization of p19INK4d protein reducing the adverse consequences on brain functions.


Assuntos
Cálcio/metabolismo , Quinase 5 Dependente de Ciclina/metabolismo , Inibidor de Quinase Dependente de Ciclina p19/metabolismo , Reparo do DNA/genética , Hipocampo/metabolismo , Neurônios/metabolismo , Peptídeos beta-Amiloides/farmacologia , Animais , Apoptose , Linhagem Celular Tumoral , Sobrevivência Celular , Cognição/fisiologia , Quinase 5 Dependente de Ciclina/genética , Inibidor de Quinase Dependente de Ciclina p19/genética , Citotoxinas/farmacologia , Dano ao DNA , Retroalimentação Fisiológica , Regulação da Expressão Gênica , Hipocampo/citologia , Hipocampo/efeitos dos fármacos , Humanos , Camundongos , Neurônios/citologia , Neurônios/efeitos dos fármacos , Fragmentos de Peptídeos/farmacologia , Fosforilação/efeitos dos fármacos , Cultura Primária de Células , Transdução de Sinais , Transcrição Gênica , Zinostatina/farmacologia
11.
Physiol Behav ; 129: 237-54, 2014 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-24607933

RESUMO

Malnutrition is a worldwide problem affecting millions of unborn and young children during the most vulnerable stages of their development. In humans, poor maternal nutrition is a major cause of intrauterine growth restriction which is associated with an increased risk of perinatal mortality and long-term morbidity. In addition, intrauterine growth restriction correlates with neurodevelopmental delays and alterations of brain structure and neurochemistry. While there is no doubt that maternal malnutrition is a principal cause of perturbed development of the fetal brain and that all nutrients have certain influence on brain maturation, proteins appear to be the most critical for the development of neurological functions. In the present study we assessed male and female mouse offspring, born to dams protein restricted during pregnancy and lactation, in physical growth and neurobehavioral development and also in social interaction, motivation, anxiety and depressive behaviors. Moreover, we evaluate the impact of the low protein diet on dams in relation to their maternal care and anxiety-related behavior given that these clearly affect pups development. We observed that maternal protein restriction during pregnancy and lactation delayed the physical growth and neurodevelopment of the offspring in a sex-independent manner. In addition, maternal undernutrition negatively affected offspring's juvenile social play, motivation, exploratory activity and risk assessment behaviors. These findings show that protein restriction during critical periods of development detrimentally program progeny behavior.


Assuntos
Ansiedade/etiologia , Depressão/etiologia , Crescimento , Fenômenos Fisiológicos da Nutrição Materna , Desnutrição Proteico-Calórica/complicações , Reflexo , Comportamento Social , Animais , Comportamento Animal , Tomada de Decisões , Comportamento Exploratório , Feminino , Lactação , Masculino , Comportamento Materno/fisiologia , Camundongos Endogâmicos , Motivação , Gravidez , Efeitos Tardios da Exposição Pré-Natal , Risco , Fatores Sexuais
12.
Biochim Biophys Acta ; 1840(7): 2171-83, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24667034

RESUMO

BACKGROUND: During evolution, organisms with renewable tissues have developed mechanisms to prevent tumorigenesis, including cellular senescence and apoptosis. Cellular senescence is characterized by a permanent cell cycle arrest triggered by both endogenous stress and exogenous stress. The p19INK4d, a member of the family of cyclin-dependent kinase inhibitors (INK4), plays an important role on cell cycle regulation and in the cellular DNA damage response. We hypothesize that p19INK4d is a potential factor involved in the onset and/or maintenance of the senescent state. METHODS: Senescence was confirmed by measuring the cell cycle arrest and the senescence-associated ß-galactosidase activity. Changes in p19INK4d expression and localization during senescence were determined by Western blot and immunofluorescence assays. Chromatin condensation was measured by microccocal nuclease digestion and histone salt extraction. RESULTS: The data presented here show for the first time that p19INK4d expression is up-regulated by different types of senescence. Changes in senescence-associated hallmarks were driven by modulation of p19 expression indicating a direct link between p19INK4d induction and the establishment of cellular senescence. Following a senescence stimulus, p19INK4d translocates to the nucleus and tightly associates with chromatin. Moreover, reduced levels of p19INK4d impair senescence-related global genomic heterochromatinization. Analysis of p19INK4d mRNA and protein levels in tissues from differently aged mice revealed an up-regulation of p19INK4d that correlates with age. CONCLUSION: We propose that p19INK4d participates in the cellular mechanisms that trigger senescence by contributing to chromatin compaction. GENERAL SIGNIFICANCE: This study provides novel insights into the dynamics process of cellular senescence, a central tumor suppressive mechanism.


Assuntos
Envelhecimento/genética , Senescência Celular/genética , Inibidor de Quinase Dependente de Ciclina p19/genética , Heterocromatina/genética , Animais , Carcinogênese , Pontos de Checagem do Ciclo Celular/genética , Inibidor de Quinase Dependente de Ciclina p19/metabolismo , Dano ao DNA/genética , Regulação da Expressão Gênica , Camundongos , beta-Galactosidase/biossíntese
13.
Cell Cycle ; 8(20): 3340-8, 2009 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-19806028

RESUMO

When DNA is damaged in cells progressing through S phase, replication blockage can be avoided by TLS (Translesion DNA synthesis). This is an auxiliary replication mechanism that relies on the function of specialized polymerases that accomplish DNA damage bypass. Intriguingly, recent evidence has linked TLS polymerases to processes that can also take place outside S phase such as nucleotide excision repair (NER). Here we show that Pol eta is recruited to UV-induced DNA lesions in cells outside S phase including cells permanently arrested in G(1). This observation was confirmed by different strategies including global UV irradiation, local UV irradiation and local multi-photon laser irradiation of single nuclei in living cells. The potential connection between Pol eta recruitment to DNA lesions outside S phase and NER was further evaluated. Interestingly, the recruitment of Pol eta to damage sites outside S phase did not depend on active NER, as UV-induced focus formation occurred normally in XPA, XPG and XPF deficient fibroblasts. Our data reveals that the re-localization of the TLS polymerase Pol eta to photo-lesions might be temporally and mechanistically uncoupled from replicative DNA synthesis and from DNA damage processing.


Assuntos
Dano ao DNA , DNA Polimerase Dirigida por DNA/metabolismo , Linhagem Celular Tumoral , Reparo do DNA , Proteínas de Ligação a DNA/deficiência , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , DNA Polimerase Dirigida por DNA/análise , Endonucleases/deficiência , Endonucleases/genética , Endonucleases/metabolismo , Fase G1 , Humanos , Proteínas Nucleares/deficiência , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Antígeno Nuclear de Célula em Proliferação/metabolismo , Fase S , Fatores de Transcrição/deficiência , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Raios Ultravioleta , Proteína de Xeroderma Pigmentoso Grupo A/genética , Proteína de Xeroderma Pigmentoso Grupo A/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...