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1.
Artigo em Inglês | MEDLINE | ID: mdl-38821379

RESUMO

INTRODUCTION: Hemorrhoidal pathology is the most frequent proctological problem with a prevalence of 44% of the adult population. The most effective treatment is surgery but it also has the highest postoperative pain rate with moderate to severe pain rates of 30-40% during the first 24-48 hours. Here lies the importance of seeking measures to improve this situation, such as the pudendal nerve block with local anesthetic. However, the variability of the pudendal nerve sometimes makes its blockade ineffective and for this reason nerve location methods are sought to achieve a higher rate of success. The main aim of the study is to compare pain in the immediate postoperative period (24 h) after hemorrhoidectomy in patients with pudendal nerve block guided by anatomical references and guided by neurostimulation. METHODS: The present project proposes the performance of a single-center, triple-blind, randomized clinical trial of efficacy, carried out under conditions of routine clinical practice. Patients over 18 years old with hemorrhoids refractory to medical treatment, symptomatic grade III-IV and grade II hemorrhoids that do not respond to conservative procedures in a third level hospital in Spain and that are subsidiaries of surgery in major ambulatory surgery will be included. Demographic variables, variables on hemorrhoidal pathology, details of surgery, verbal numeric pain scale in the preoperative period and surgical complications will be collected. RESULTS: Not avaliable until the end of the study. CONCLUSIONS: The pudendal nerve block guided by anatomical landmarks has been shown to be useful in postoperative pain control after hemorrhoidectomy although the use of the neurostimulator has not been well studied and we believe it may improve outcom.

2.
Am J Gastroenterol ; 113(3): 396-403, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29460920

RESUMO

OBJECTIVES: The long-term safety of exposure to anti-tumor necrosis factor (anti-TNFα) drugs during pregnancy has received little attention. We aimed to compare the relative risk of severe infections in children of mothers with inflammatory bowel disease (IBD) who were exposed to anti-TNFα drugs in utero with that of children who were not exposed to the drugs. METHODS: Retrospective multicenter cohort study. Exposed cohort: children from mothers with IBD receiving anti-TNFα medication (with or without thiopurines) at any time during pregnancy or during the 3 months before conception. Non-exposed cohort: children from mothers with IBD not treated with anti-TNFα agents or thiopurines at any time during pregnancy or the 3 months before conception. The cumulative incidence of severe infections after birth was estimated using Kaplan-Meier curves, which were compared using the log-rank test. Cox-regression analysis was performed to identify potential predictive factors for severe infections in the offspring. RESULTS: The study population comprised 841 children, of whom 388 (46%) had been exposed to anti-TNFα agents. Median follow-up after delivery was 47 months in the exposed group and 68 months in the non-exposed group. Both univariate and multivariate analysis showed the incidence rate of severe infections to be similar in non-exposed and exposed children (1.6% vs. 2.8% per person-year, hazard ratio 1.2 (95% confidence interval 0.8-1.8)). In the multivariate analysis, preterm delivery was the only variable associated with a higher risk of severe infection (2.5% (1.5-4.3)). CONCLUSIONS: In utero exposure to anti-TNFα drugs does not seem to be associated with increased short-term or long-term risk of severe infections in children.


Assuntos
Antirreumáticos/uso terapêutico , Infecções/epidemiologia , Doenças Inflamatórias Intestinais/tratamento farmacológico , Complicações na Gravidez/tratamento farmacológico , Nascimento Prematuro/epidemiologia , Efeitos Tardios da Exposição Pré-Natal/epidemiologia , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Adalimumab/uso terapêutico , Adulto , Estudos de Casos e Controles , Certolizumab Pegol/uso terapêutico , Pré-Escolar , Estudos de Coortes , Europa (Continente)/epidemiologia , Feminino , Humanos , Incidência , Lactente , Recém-Nascido , Infliximab/uso terapêutico , Estimativa de Kaplan-Meier , Masculino , Análise Multivariada , Gravidez , Modelos de Riscos Proporcionais , Estudos Retrospectivos
3.
Br J Dermatol ; 178(1): 198-206, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28733979

RESUMO

BACKGROUND: Naevoid basal cell carcinoma syndrome (NBCCS) is an autosomal dominant disorder characterized by developmental alterations and multiple basal cell carcinomas. Mutations in PTCH1, which encodes a membrane receptor for Sonic Hedgehog, are associated with the development of the disease. Most of them produce a truncated protein, which is unable to suppress Smoothened protein and continuously activates the downstream pathway. OBJECTIVES: We aimed to characterize 22 unrelated Spanish patients with NBCCS, the largest cohort with Gorlin syndrome reported to date in Spain. METHODS: Genomic analysis of PTCH1 was performed in patients with NBCCS and controls, and mutations were analysed using bioinformatics tools. RESULTS: We report for the first time two young patients, one each with uterus didelphys and ganglioneuroma, within the context of NBCCS. One patient showing a severe phenotype of the disease had developed basal cell carcinomas since childhood. Sanger sequencing of PTCH1 in this cohort identified 17 novel truncating mutations (11 frameshift, five nonsense and one mutation affecting an exon-intron splice site) and two novel missense mutations that were predicted to be pathogenic. The patients showed great clinical variability and inconsistent genotype-phenotype correlation, as seen in relatives carrying similar mutations. CONCLUSIONS: This study contributes to increase the pool of clinical manifestations of NBCCS, as well as increasing the number of pathogenic mutations identified in PTCH1 predisposing to the condition. The inconsistencies found between phenotype and genotype suggest the involvement of other modifying factors, genetic, epigenetic or environmental.


Assuntos
Síndrome do Nevo Basocelular/genética , Mutação/genética , Receptor Patched-1/genética , Neoplasias Cutâneas/genética , Adolescente , Adulto , Idoso , Síndrome do Nevo Basocelular/epidemiologia , Síndrome do Nevo Basocelular/patologia , Criança , Predisposição Genética para Doença/genética , Genótipo , Humanos , Pessoa de Meia-Idade , Fenótipo , Neoplasias Cutâneas/epidemiologia , Neoplasias Cutâneas/patologia , Espanha/epidemiologia , Adulto Jovem
4.
J Thorac Oncol ; 11(12): 2183-2192, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27524264

RESUMO

INTRODUCTION: Lung cancer (LC) and chronic obstructive pulmonary disease (COPD) are smoking-related diseases, with the presence of COPD itself increasing the risk for development of LC, probably owing to underlying inflammation. LC is typically detected at late stages of the disease and carries a poor prognosis. There is an unmet need for methods to facilitate the early detection of LC in high-risk subjects such as smokers. METHODS: The expression of inflammatory proteins in bronchoalveolar lavage fluid (BALF) samples was studied by antibody arrays in a prospective cohort of 60 smokers of more than 30 pack-years divided into four groups (control, patients with LC, patients with COPD, and patients with LC plus COPD). Relevant biomarkers were validated by Western blot. Additional validation with enzyme-linked immunosorbent assay (ELISA) was carried out on two independent controlled cohorts of 139 patients (control, patients with LC, patients with COPD, and patients with LC plus COPD) and 160 patients (control and patients with LC of all histological types). RESULTS: A total of 16 differentially expressed proteins in samples from patients with LC, COPD, and LC plus COPD were identified by antibody arrays and validated by Western blot and ELISA. C-C motif chemokine ligand 1 (CCL-1) and interleukin-11 (IL)-11 were selectively expressed in samples from patients with adenocarcinoma with or without COPD (p < 0.005). These proteins exhibited a remarkable diagnostic performance for lung adenocarcinoma in an independent cohort of 139 patients. Receiver operating characteristic curves showed that the optimum diagnostic cutoff value for IL-11 was 42 pg/mL (area under the curve = 0.93 [95% confidence interval: 0.896-0.975], sensitivity 90%, specificity 86%), whereas for CCL-1 it was 39.5 pg/mL (0.83 [95% confidence interval: 0.749-0.902], sensitivity 83%, and specificity 74%). Further validation of the ELISA biomarkers at the aforementioned cutoffs was performed in an additional cohort of 160 patients (20 controls, 66 patients with LC, and 74 patients with LC plus COPD). There was a significant correlation between BALF levels of IL-11 and CCL-1 (r2 = 0.76, p < 0.001), and the use of both biomarkers increased the diagnostic accuracy to 96.1% in the two validation cohorts. Appropriate diagnostic performance was observed for all subgroups regardless of stage at diagnosis, involvement of the bronchial tract, pack-years smoked, and number of cells in BALF. CONCLUSIONS: IL-11 and CCL-1 are highly specific biomarkers with great accuracy for the diagnosis of lung adenocarcinoma in BALF specimens. Further study of these proteins as markers for the early diagnosis and screening of plasma and other biological materials is warranted.


Assuntos
Adenocarcinoma/genética , Biomarcadores Tumorais/metabolismo , Líquido da Lavagem Broncoalveolar/citologia , Quimiocina CCL1/metabolismo , Interleucina-11/metabolismo , Neoplasias Pulmonares/genética , Adenocarcinoma/patologia , Adenocarcinoma de Pulmão , Feminino , Humanos , Neoplasias Pulmonares/patologia , Masculino
5.
Oncogene ; 35(21): 2777-88, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-26387546

RESUMO

The spinophilin (Spn, PPP1R9B) gene is located at 17q21.33, a region frequently associated with microsatellite instability and loss of heterozygosity, especially in breast tumors. Spn is a regulatory subunit of phosphatase1a (PP1), which targets the catalytic subunit to distinct subcellular locations. Spn downregulation reduces PPP1CA activity against the retinoblastoma protein, pRb, thereby maintaining higher levels of phosphorylated pRb. This effect contributes to an increase in the tumorigenic properties of cells in certain contexts. Here, we explored the mechanism of how Spn downregulation contributes to the malignant phenotype and poor prognosis in breast tumors and found an increase in the stemness phenotype. Analysis of human breast tumors showed that Spn mRNA and protein are reduced or lost in 15% of carcinomas, correlating with a worse prognosis, a more aggressive tumor phenotype and triple-negative tumors, whereas luminal tumors showed high Spn levels. Downregulation of Spn by shRNA increased the stemness properties along with the expression of stem-related genes (Sox2, KLF4, Nanog and OCT4), whereas ectopic overexpression of Spn cDNA reduced these properties. Breast tumor stem cells appeared to have low levels of Spn mRNA, and Spn loss correlated with increased stem-like cell appearance in breast tumors as indicated by an increase in CD44+/CD24- cells. A reduction of the levels of PPP1CA mimicked the cancer stem-like cell phenotype of Spn downregulation, suggesting that the mechanism of Spn involves PP1a. These increased cancer stem cell-like properties with reduced Spn might account for the malignant phenotype observed in Spn-loss tumors and may contribute to a worse patient prognosis.


Assuntos
Neoplasias da Mama/patologia , Proteínas dos Microfilamentos/deficiência , Células-Tronco Neoplásicas/patologia , Proteínas do Tecido Nervoso/deficiência , Animais , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Estudos de Coortes , Feminino , Humanos , Fator 4 Semelhante a Kruppel , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Células-Tronco Neoplásicas/metabolismo , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Prognóstico
6.
Neuroscience ; 278: 354-66, 2014 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-25168729

RESUMO

Voltage-dependent anion channel (VDAC) is a mitochondrial protein abundantly found in neuronal lipid rafts. In these membrane domains, VDAC is associated with a complex of signaling proteins that trigger neuroprotective responses. Loss of lipid raft integrity may result in disruption of multicomplex association and alteration of signaling responses that may ultimately promote VDAC activation. Some data have demonstrated that VDAC at the neuronal membrane may be involved in the mechanisms of amyloid beta (Aß)-induced neurotoxicity, through yet unknown mechanisms. Aß is generated from amyloid precursor protein (APP), and is released to the extracellular space where it may undergo self-aggregation. Aß aggregate deposition in the form of senile plaques may lead to Alzheimer's disease (AD) neuropathology, although other pathological hallmarks (such as hyper-phosphorylated Tau deposition) also participate in this neurodegenerative process. The present study demonstrates that VDAC1 associates with APP and Aß in lipid rafts of neurons. Interaction of VDAC1 with APP was observed in lipid rafts from the frontal and entorhinal cortex of human brains affected by AD at early stages (I-IV/0-B of Braak and Braak). Furthermore, Aß exposure enhanced the dephosphorylation of VDAC1 that correlated with cell death. Both effects were reverted in the presence of tyrosine phosphatase inhibitors. VDAC1 dephosphorylation was corroborated in lipid rafts of AD brains. These results demonstrate that Aß is involved in alterations of the phosphorylation state of VDAC in neuronal lipid rafts. Modulation of this channel may contribute to the development and progression of AD pathology.


Assuntos
Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Encéfalo/metabolismo , Microdomínios da Membrana/metabolismo , Neurônios/metabolismo , Canal de Ânion 1 Dependente de Voltagem/metabolismo , Peptídeos beta-Amiloides/toxicidade , Precursor de Proteína beta-Amiloide/metabolismo , Linhagem Celular Tumoral , Células Cultivadas , Humanos , Neuroblastoma , Neurônios/efeitos dos fármacos , Fosforilação
7.
Biomacromolecules ; 14(10): 3570-80, 2013 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-24004423

RESUMO

Poly(propylene imine) (PPI) glycodendrimers are promising candidates as drug carriers and antiamyloidogenic and antiprionic agents. In this study the anti-ß-amyloid capacity of PPI glycodendrimers of the fourth and fifth generations was investigated in vitro and in vivo. We assessed distinct PPI glycodendrimers including G4mDS and G5mDS, with electroneutral maltose shell, and G4mOS and G4m-IIIOS, with cationic maltose or maltotriose shell. Our results show that in vitro PPI maltose dendrimers reduce the toxicity of Aß(1-42). However, only the electroneutral maltose dendrimers G4mDS and G5mDS reduce the toxicity of Alzheimer's disease brain extracts in SH-SY5Y neuroblastoma cells. PPI maltose dendrimers with electroneutral or cationic surface penetrate the cytoplasm of cultured cells, and they reach the brain when administered intranasally. Both cationic G4mOS and electroneutral G4mDS are able to modify the total burden of ß-amyloid in APP/PS1 mice. The studied dendrimers did not reverse memory impairment in APP/PS1 mice following chronic administration; moreover, cationic G4mOS caused cognitive decline in nontransgenic mice. In spite of the capacity of G4mDS and G4mOS to cross the blood-brain barrier and modulate Aß aggregation in APP/PS1 mice, further studies are needed to learn how to reduce the harmful effects of maltose dendrimers in vivo.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Precursor de Proteína beta-Amiloide/metabolismo , Dendrímeros/farmacologia , Glicoconjugados/farmacologia , Polipropilenos/farmacologia , Proteínas Serina-Treonina Quinases/metabolismo , Administração Intranasal , Doença de Alzheimer/metabolismo , Precursor de Proteína beta-Amiloide/genética , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/patologia , Sobrevivência Celular/efeitos dos fármacos , Dendrímeros/administração & dosagem , Dendrímeros/química , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Glicoconjugados/administração & dosagem , Glicoconjugados/química , Humanos , Masculino , Maltose/química , Camundongos , Camundongos Transgênicos , Tamanho da Partícula , Polipropilenos/administração & dosagem , Polipropilenos/química , Proteínas Serina-Treonina Quinases/genética , Relação Estrutura-Atividade , Propriedades de Superfície , Células Tumorais Cultivadas
9.
Oncogene ; 31(41): 4447-59, 2012 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-22266858

RESUMO

MAP17 is a small, 17-kDa, non-glycosylated membrane protein that is overexpressed in a percentage of carcinomas. In the present work, we have analyzed the role of MAP17 expression during mammary cancer progression. We have found that MAP17 is expressed in 60% human mammary tumors while it is not expressed in normal or benign neoplasias. MAP17 levels increased with breast tumor stage and were strongly correlated with mammary tumoral progression. A significant increase in the levels of reactive oxygen species (ROS) was observed in MAP17-expressing cells, as compared with parental cells. This increase was further paralleled by an increase in the tumorigenic capacity of carcinoma cells but not in immortal non-tumoral breast epithelial cells, which provides a selective advantage once tumorigenesis has begun. Expression of specific MAP17 shRNA in protein-expressing tumor cells reduced their tumorigenic capabilities, which suggests that this effect is dependent upon MAP17 protein expression. Our data show that ROS functions as a second messenger that enhances tumoral properties, which are inhibited in non-tumoral cells. We have found that p38α activation mediates this response. MAP17 triggers a ROS-dependent, senescence-like response that is abolished in the absence of p38a activation. Furthermore, in human breast tumors, MAP17 activation is correlated with a lack of phosphorylation of p38α. Therefore, MAP17 is overexpressed in late-stage breast tumors, in which oncogenic activity relies on p38 insensitivity to induce intracellular ROS.


Assuntos
Neoplasias da Mama/enzimologia , Proteínas de Membrana/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Ativação Enzimática , Feminino , Expressão Gênica , Humanos , Glândulas Mamárias Humanas/patologia , Proteínas de Membrana/genética , Estadiamento de Neoplasias , Oncogenes , Espécies Reativas de Oxigênio/metabolismo , Análise Serial de Tecidos
10.
Neuroscience ; 200: 106-19, 2012 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-22079575

RESUMO

α-synuclein is a key protein in Lewy body diseases (LBDs) and a major component of Lewy bodies and related aberrant cytoplasmic and neuritic inclusions. Regional differences in α-synuclein have been associated with selective neuronal vulnerability to Lewy pathology. Furthermore, phosphorylation at serine 129 (Ser129) and α-synuclein truncation have been considered crucial in the pathogenesis of Lewy inclusions. The present study shows consistent reduction in α-synuclein protein expression levels in the human substantia nigra and nucleus basalis of Meynert compared with other brain regions independently of age and pathology. Phosphorylated α-synuclein at Ser129 is naturally increased in these same regions, thus inversely related with the total amount of α-synuclein. In contrast, truncated α-synuclein is naturally observed in control and diseased brains and correlating with the total amount of α-synuclein. Several truncated variants have been identified where some of these variants are truncated at the C-terminal domain, whereas others are truncated at the N-terminal domain, and all are present in cases with and without Lewy pathology. Although accumulation of truncated α-synuclein variants and phosphorylated α-synuclein occurs in Lewy bodies, α-synuclein phosphorylation and truncation can be considered constitutive in control and diseased brains.


Assuntos
Encéfalo/metabolismo , Serina/metabolismo , alfa-Sinucleína/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Encéfalo/citologia , Linhagem Celular Tumoral , Feminino , Humanos , Corpos de Lewy/metabolismo , Doença por Corpos de Lewy/metabolismo , Doença por Corpos de Lewy/patologia , Masculino , Espectrometria de Massas , Camundongos , Camundongos Transgênicos , Microscopia Confocal , Pessoa de Meia-Idade , Mutação/genética , Proteínas do Tecido Nervoso/metabolismo , Neuroblastoma/patologia , Neurônios/ultraestrutura , Fosforilação/fisiologia , Mudanças Depois da Morte , Estrutura Terciária de Proteína/genética , Frações Subcelulares/metabolismo , Fatores de Tempo , Transfecção/métodos , alfa-Sinucleína/genética
11.
Neuropathol Appl Neurobiol ; 37(5): 484-99, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21114681

RESUMO

AIM: Neuropathological changes classically associated with sheep scrapie do not always correlate with clinical disease. We aimed to determine if selected neuromodulatory responses were altered during the course of the infection as it has been described in Creutzfeldt-Jakob disease and experimental bovine spongiform encephalopathy. METHODS: Hemi-brains from healthy sheep and natural scrapie cases at two stages of infection were examined for biochemical alterations related to the expression of type I metabotropic glutamatergic receptors (mGluR(1) ) and type I adenosine receptors I (A(1) R), and of selected downstream intermediate signalling targets. Immunohistochemistry for different scrapie-related neuropathological changes was performed in the contralateral hemi-brains. RESULTS: PrP(d) deposition, spongiform change, astrocytosis and parvalbumin expression were significantly altered in brains from clinically affected sheep compared with preclinical cases and negative controls; the latter also showed significantly higher immunoreactivity for synaptophysin than clinical cases. Between clinically affected and healthy sheep, no differences were found in the protein levels of mGluR(1) , while phospholipase Cß1 expression in terminally ill sheep was increased in some brain areas but decreased in others. Adenyl cyclase 1 and A(1) R levels were significantly lower in various brain areas of affected sheep. No abnormal biochemical expression levels of these markers were found in preclinically infected sheep. CONCLUSIONS: These findings point towards an involvement of mGluR(1) and A(1) R downstream pathways in natural scrapie. While classical prion disease lesions and neuromodulatory responses converge in some affected regions, they do not do so in others suggesting that there are independent regulatory factors for distinct degenerative and neuroprotective responses.


Assuntos
Receptor A1 de Adenosina/biossíntese , Receptores de Glutamato Metabotrópico/biossíntese , Scrapie/metabolismo , Scrapie/patologia , Animais , Western Blotting , Encéfalo/metabolismo , Encéfalo/patologia , Imuno-Histoquímica , Ovinos
12.
Pathobiology ; 76(3): 129-35, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19468252

RESUMO

OBJECTIVES: Recovery from stroke is dependent on the survival of neurons in the dynamic peri-infarcted region. Although several markers of neuronal injury and apoptotic cell death have been described, administration of neuroprotective drugs directed at specific molecules has had limited success. A complete understanding of deregulated genes associated with neuronal death would be beneficial. Our previous microarray studies identified increased expression of a novel protein, the B-cell translocation gene 2 (BTG2), in infarcted regions. METHODS: We have used immunohistochemistry and Western blotting to examine the expression and localization of BTG2 in stroked brain tissue and immunofluorescent staining of human fetal brain neurons to determine if oxygen-glucose deprivation affected its expression. RESULTS: We show that BTG2 is strongly expressed in peri-infarcted and infarcted regions of brain tissue, localizing in neuronal nuclei and cytoplasm, whilst being absent or very weakly expressed in normal looking contralateral tissue. Exposure of human fetal brain neurons to oxygen-glucose deprivation also induced BTG2 expression in the cytoplasm and perinuclear regions of cells staining positive for propidium iodide (a marker of nuclear damage). CONCLUSIONS: BTG2 may be a modulator of cell survival and differentiation and could help to protect against cell death by inhibition of necrosis and/or apoptotic signalling pathways.


Assuntos
Isquemia Encefálica/metabolismo , Encéfalo/metabolismo , Proteínas Imediatamente Precoces/metabolismo , Neurônios/metabolismo , Acidente Vascular Cerebral/metabolismo , Idoso , Idoso de 80 Anos ou mais , Western Blotting , Células Cultivadas , Feminino , Feto , Imunofluorescência , Genes Supressores de Tumor , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Proteínas Supressoras de Tumor
13.
Carcinogenesis ; 29(11): 2089-95, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18713839

RESUMO

With the idea to discover novel genes involved in proliferation, we have performed a genome-wide loss-of-function genetic screen to identify additional putative tumor suppressor genes. We have previously identified five genes belonging to different biochemical families. In this report, we focused on the study of one of these genes designated S-adenosylhomocysteine hydrolase (SAHH), which has also been previously identified in an independent short hairpin RNA screening. SAHH inactivation confers resistance to both p53 and p16(INK4)-induced proliferation arrest. Interestingly, SAHH inactivation inhibits p53 transcriptional activity and impairs DNA damage-induced transcription of p21(Cip1). Given that SAHH downregulation modulates senescence in primary cells, we also studied SAHH expression in human tumors at the messenger RNA (mRNA) and protein levels. SAHH mRNA was lost in 50% of tumor tissues from 206 patients with different kinds of tumors in comparison with normal tissue counterparts. Moreover, SAHH protein was also affected in some colon cancers. Such findings may be of relevance to cancer research, suggesting that SAHH might be a largely unexplored tumor suppressor.


Assuntos
Adenosil-Homocisteinase/genética , Regulação para Baixo , Animais , Divisão Celular , Feminino , Células HeLa , Humanos , Camundongos , Células NIH 3T3 , Reação em Cadeia da Polimerase , Gravidez , RNA Interferente Pequeno , Proteína do Retinoblastoma/metabolismo , Proteína Supressora de Tumor p53/metabolismo
14.
Neuroscience ; 154(4): 1388-97, 2008 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-18538940

RESUMO

We examined the expression of SIRT1 in several experimental paradigms of human pathologies. We used a neuroblastoma cell line (B65), neuronal primary cultures (hippocampus and cerebellar granule cells) and in vivo approaches in rat and senescence murine models (SAM). Cell cultures and rats were treated with several well-know neurotoxins, i.e. rotenone, MPP(+), kainate and 3-nitropropionic acid. Subsequently, SIRT1 expression was compared in these different paradigms of neurotoxicity. The pattern of expression of SIRT1 in proliferating cell cultures (B65) was different to that in quiescent cell cultures. In the murine model of senescence (senescence-accelerated mice prone, SAMP8), SIRT1 expression progressively decreased, while in the control strain (senescence-accelerated mice resistant, SAMR1) it increased. Finally, we studied human samples of Parkinson's disease (PD), dementia with Lewy bodies (DLB) and Huntington's diseases (HD). SIRT1 expression decreased dramatically in HD, but there were no significant changes in Parkinson-related illnesses. In conclusion, SIRT1 expression may be a good sensor of toxic neuronal processes.


Assuntos
Envelhecimento/metabolismo , Doenças Neurodegenerativas/metabolismo , Sirtuínas/metabolismo , Animais , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Western Blotting , Células Cultivadas , Citometria de Fluxo , Humanos , Masculino , Camundongos , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Neurotoxinas/farmacologia , Ratos , Ratos Sprague-Dawley , Sirtuína 1 , Sirtuínas/efeitos dos fármacos
16.
Neuroscience ; 152(4): 913-23, 2008 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-18343584

RESUMO

Phosphorylation of tau and phosphorylation of alpha-synuclein are crucial abnormalities in Alzheimer's disease (AD) and alpha-synucleinopathies (Parkinson's disease: PD, and dementia with Lewy bodies: DLB), respectively. The presence and distribution of phospho-tau were examined by sub-fractionation, gel electrophoresis and Western blotting in the frontal cortex of cases with AD at different stages of disease progression, PD, DLB pure form and common form, and in age-matched controls. Phospho-tauSer396 has been found in synaptic-enriched fractions in AD frontal cortex at entorhinal/transentorhinal, limbic and neocortical stages, thus indicating early tau phosphorylation at the synapses in AD before the occurrence of neurofibrillary tangles in the frontal cortex. Phospho-tauSer396 is also found in synaptic-enriched fractions in the frontal cortex in PD and DLB pure and common forms, thus indicating increased tau phosphorylation at the synapses in these alpha-synucleinopathies. Densitometric studies show between 20% and 40% phospho-tauSer396, in relation with tau-13, in synaptic-enriched fractions of the frontal cortex in AD stages I-III, and in PD and DLB. The percentage reaches about 95% in AD stage V and DLB common form. Yet tau phosphorylation characteristic of neurofibrillary tangles, as revealed with the AT8 antibody, is found in the synaptic fractions of the frontal cortex only at advanced stages of AD. Increased phosphorylated alpha-synucleinSer129 levels are observed in the synaptic-enriched fractions of the frontal cortex in PD and DLB pure and common forms, and in advanced stages of AD. Since tau-hyperphosphorylation has implications in microtubule assembly, and phosphorylation of alpha-synuclein at Ser129 favors alpha-synuclein aggregation, it can be suggested that synapses are targets of abnormal tau and alpha-synuclein phosphorylation in both groups of diseases. Tau phosphorylation at Ser396 has also been found in synaptic-enriched fractions in 12-month-old transgenic mice bearing the A53T alpha-synuclein mutation.


Assuntos
Doença de Alzheimer/patologia , Osso Frontal/patologia , Doença de Parkinson/patologia , Sinapses/metabolismo , alfa-Sinucleína/metabolismo , Proteínas tau/metabolismo , Idoso , Idoso de 80 Anos ou mais , Biópsia/métodos , Estudos de Casos e Controles , Quinase 5 Dependente de Ciclina/metabolismo , Feminino , Quinase 3 da Glicogênio Sintase/metabolismo , Glicogênio Sintase Quinase 3 beta , Humanos , Masculino , Microscopia Eletrônica de Transmissão/métodos , Pessoa de Meia-Idade , Fosforilação , Serina/metabolismo , Sinapses/ultraestrutura , Sinaptofisina/metabolismo
17.
J Chromatogr A ; 1183(1-2): 38-48, 2008 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-18241873

RESUMO

In the present study the photocatalytic degradation of bezafibrate (BZF), a lipid regulator agent, has been investigated using TiO(2) suspensions and simulated solar light. The study focus on the identification of degradation products (DPs) using powerful analytical techniques such as liquid chromatography time of flight mass spectrometry (LC-TOF-MS), gas chromatography mass spectrometry (GC-MS), and high-performance liquid chromatography with diode-array detection (HPLC-DAD). Each technique provided complementary information that enabled the identification of 21 DPs. Accurate mass measurements obtained by LC-TOF-MS provided the elucidation of 17 DPs. Mass errors lower than 2mDa, allowed the assignment of empirical formula for the mayor DPs to be determined confidently. Three DPs were identified by GC-MS through the structural information provided by full scan mass spectra obtained by electron impact (EI) ionization and two more by HPLC-DAD by comparing the retention times (t(R)) and the UV spectra of the unknown DPs with those of commercial standards. Based on this by-product identification a possible multi-step degradation scheme was proposed. The pathways include single or multiple hydroxylation of BZF with subsequent phenoxy ring opening and the cleavage of the amide and ether bonds.


Assuntos
Bezafibrato/efeitos da radiação , Catálise , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Cromatografia Gasosa-Espectrometria de Massas , Fotoquímica , Espectrometria de Massas por Ionização por Electrospray , Titânio
18.
Neuropathol Appl Neurobiol ; 34(1): 76-87, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17931355

RESUMO

Protein aggregates in muscle cells are the morphological hallmark of myofibrillar myopathies, including myotilinopathies and desminopathies. The aim of the present study is to analyse the expression of mutant ubiquitin (UBB+1), an aberrant form of ubiquitin which accumulates in certain disorders characterized by intracellular aggregates of proteins, and p62, a multimeric signal protein which plays an active role in aggregate formation, in muscle biopsies from patients suffering from myotilinopathy and desminopathy in order to gain understanding of the mechanisms leading to protein aggregation in these disorders. Single immunohistochemistry, and single- and double-labelling immunofluorescence and confocal microscopy for UBB+1 and p62, has been performed in muscle biopsies from patients suffering from myotilinopathy and desminopathy. Strong UBB+1 immunoreactivity, colocalizing with myotilin aggregates, was found in muscle fibres in myotilinopathies. UBB+1 accumulation, colocalizing with desmin aggregates, also occurs in desminopathies. In addition, strong p62 immunoreactivity colocalizing with myotilin aggregates was observed in myotilinopathies. Similarly, p62 immunoreactivity colocalizing with desmin aggregates was found in desminopathies. The present findings suggest that accumulation of protein aggregates in myotilinopathies and in desminopathies may be related with UBB+1/abnormal protein complexes which are resistant to proteasome degradation. Furthermore, these observations suggest a relationship between the presence of p62 and the formation of inclusions in different subtypes of myofibrillar myopathies.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/biossíntese , Proteínas do Citoesqueleto/genética , Desmina/genética , Proteínas Musculares/genética , Doenças Musculares/metabolismo , Ubiquitina/biossíntese , Idoso , Idoso de 80 Anos ou mais , Biópsia , Conectina , Feminino , Imunofluorescência , Humanos , Imuno-Histoquímica , Masculino , Proteínas dos Microfilamentos , Microscopia Confocal , Pessoa de Meia-Idade , Doenças Musculares/genética , Doenças Musculares/patologia , Mutação , Proteína Sequestossoma-1 , Ubiquitina/genética
19.
Neurosci Lett ; 423(3): 194-9, 2007 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-17707587

RESUMO

Expression of adenosine receptors of the A1, A2A and A2B type has been examined in the post-mortem frontal cortex and hippocampus in argyrophilic grain disease (AGD), a tauopathy affecting the hippocampus but usually not the frontal cortex, in an attempt to learn about the modulation of the adenosine pathway in this disorder. Significant increased levels of A1, but not of A2A and A2B, have been observed in AGD in the hippocampus but not in the frontal cortex, when compared with age-matched controls. This is accompanied by increased levels of adenylyl cyclase (AC), an effector of A1, and by increased (although not significant) percentage of inhibition of forskolin-stimulated AC by the A1 agonist cyclohexyladenosine in the hippocampus in AGD. These findings indicate sensitization of A1/AC in the hippocampus in AGD, and support a putative activation of the A1/AC pathway that may facilitate protection of this preferentially involved region in AGD.


Assuntos
Transtornos Cognitivos/etiologia , Demência/etiologia , Lobo Frontal/metabolismo , Hipocampo/metabolismo , Receptores Purinérgicos P1/metabolismo , Tauopatias/metabolismo , Tauopatias/psicologia , Agonistas do Receptor A1 de Adenosina , Inibidores de Adenilil Ciclases , Adenilil Ciclases/metabolismo , Idoso , Idoso de 80 Anos ou mais , Cadáver , Colforsina/farmacologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fenilalanina/análogos & derivados , Fenilalanina/farmacologia , Receptor A1 de Adenosina/metabolismo , Receptor A2A de Adenosina/metabolismo , Receptor A2B de Adenosina/metabolismo , Coloração pela Prata , Tauopatias/patologia
20.
Neurosci Lett ; 421(1): 10-5, 2007 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-17548164

RESUMO

Expression levels and localization of transcription factors cAMP response element binding protein (CREB(1) and CREB(2)) and c-Fos, as well as levels of up-stream mitogen-activated protein kinases/extracellular signal-regulated kinases (ERK-1 and ERK-2) and p38 kinase, were examined in the brains (frontal cortex) of eleven cases with Creutzfeldt-Jakob disease (CJD) and five age-matched controls. Preserved expression levels of ERK-1-P, ERK-2-P and p38-P were observed in CJD. However, significantly reduced levels, as revealed by gel electrophoresis and Western blotting, and reduced numbers of immunoreactive nuclei, as seen by immunohistochemistry, to CREB, CREB-P, c-Fos and c-Fos-P were found in CJD when compared with controls. These observations point to exhausted CREB and c-Fos brain responses, in spite of preserved up-stream signaling kinases, thus favoring cell death in terminal stages of CJD.


Assuntos
Proteína de Ligação a CREB/metabolismo , Síndrome de Creutzfeldt-Jakob/patologia , Regulação da Expressão Gênica/fisiologia , Proteínas Proto-Oncogênicas c-fos/metabolismo , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Síndrome de Creutzfeldt-Jakob/genética , Síndrome de Creutzfeldt-Jakob/metabolismo , Feminino , Expressão Gênica/fisiologia , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Mudanças Depois da Morte
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