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2.
Br J Cancer ; 119(3): 388, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29930252

RESUMO

The authors report that there is a mistake in the representative picture of Fig. 4D (top row: PC3-miR1260b inh-0h) in the original version. The correct version of Fig. 4 with the original pictures for both PC3 miR-NC inh-0h and PC3-miR1260b inh-0h are provided below.

5.
Acta Orthop Belg ; 82(2): 210-215, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27682282

RESUMO

The purpose of this study was to review the clinical results of carpal ligaments injuries with scaphoid nonunion. We hypothesized that scaphoid nonunion with carpal ligament injury is associated with clinical result. We retrospectively reviewed 60 cases of -Herbert screw fixation with bone graft for scaphoid nonunions. Scapholunate (SL) and lunotriquetral (LT) ligaments lesions were confirmed by arthroscopy. Approximately half of the nonunion scaphoid cases had carpal ligaments injuries. At final follow-up evaluation, wrist function as evaluated by the Mayo wrist score was excellent in 34 patients, good in 16 patients, fair in 8 patients, and poor in 2 patients. Cases with both SL/LT ligaments injuries tended to have decreased wrist flexion-extension motion. Our results suggest that there is an indication for arthroscopy in scaphoid nonunion if surgical fixation is offered to avoid detrimental effects of an undiagnosed ligament tear.


Assuntos
Fraturas não Consolidadas/complicações , Ligamentos Articulares/lesões , Osso Escafoide/lesões , Traumatismos do Punho/complicações , Adulto , Artroscopia , Parafusos Ósseos , Feminino , Fixação Interna de Fraturas , Fraturas não Consolidadas/diagnóstico por imagem , Fraturas não Consolidadas/cirurgia , Humanos , Ligamentos Articulares/cirurgia , Masculino , Radiografia , Amplitude de Movimento Articular , Estudos Retrospectivos , Osso Escafoide/diagnóstico por imagem , Osso Escafoide/cirurgia , Traumatismos do Punho/diagnóstico por imagem , Traumatismos do Punho/cirurgia
6.
Acta Orthop Belg ; 82(2): 313-318, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27682294

RESUMO

The aim of this study was to identify the fragment's shape by evaluating olecranon fractures. We examined the CT images of 48 olecranon fractures (28 women and 20 men). Mean age was 59.9 years. On the olecranon's posterior surface, we measured the distance between the apex of the olecranon fragment and the radial edge of the flat spot on the short axis and the width of the flat spot on the same short axis. The tip radial ratio (i.e., the tip radial edge to the flat spot width) was derived from these parameters. The mean tip radial edge was 1.96 mm, and the flat spot width was 12.64 mm ; therefore, the tip radial ratio was 0.15 mm. Radial inclination on the articular surface was 30.55°. Our findings confirmed our hypothesis that the fracture lines run from the proximal ulnar side to the distal radial side on the olecranon's posterior and articular surfaces.


Assuntos
Olécrano/lesões , Olécrano/patologia , Fraturas da Ulna/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Fixação Interna de Fraturas , Humanos , Masculino , Pessoa de Meia-Idade , Olécrano/diagnóstico por imagem , Estudos Retrospectivos , Tomografia Computadorizada por Raios X , Fraturas da Ulna/diagnóstico por imagem , Fraturas da Ulna/cirurgia , Adulto Jovem
7.
Br J Cancer ; 112(3): 532-8, 2015 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-25584485

RESUMO

BACKGROUND: Predictive biomarkers for the recurrence of hepatocellular carcinoma (HCC) have great benefit in the selection of treatment options, including liver transplantation (LT), for HCC. The purpose of this study was to identify specific microRNAs (miRs) in exosomes from the serum of patients with recurrent HCC and to validate these molecules as novel biomarkers for HCC recurrence. METHODS: We employed microarray-based expression profiling of miRs derived from exosomes in the serum of HCC patients to identify a biomarker that distinguishes between patients with and without HCC recurrence after LT. This was followed by the validation in a separate cohort of 59 HCC patients who underwent living related LT. The functions and potential gene targets of the recurrence-specific miRs were analysed using a database, clinical samples and HCC cell lines. RESULTS: We found that miR-718 showed significantly different expression in the serum exosomes of HCC cases with recurrence after LT compared with those without recurrence. Decreased expression of miR-718 was associated with HCC tumour aggressiveness in the validated cohort series. We identified HOXB8 as a potential target gene of miR-718, and its upregulation was associated with poor prognosis. CONCLUSION: Circulating miRs in serum exosomes have potential as novel biomarkers for predicting HCC recurrence.


Assuntos
Biomarcadores Tumorais/sangue , Carcinoma Hepatocelular/sangue , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/sangue , Neoplasias Hepáticas/patologia , Transplante de Fígado , MicroRNAs/sangue , Adulto , Idoso , Carcinoma Hepatocelular/cirurgia , Células Cultivadas , Exossomos , Feminino , Proteínas de Homeodomínio/genética , Humanos , Neoplasias Hepáticas/cirurgia , Masculino , Pessoa de Meia-Idade , Prognóstico , Falha de Tratamento , Adulto Jovem
8.
Br J Cancer ; 110(6): 1645-54, 2014 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-24504368

RESUMO

BACKGROUND: Recently several microRNAs (miRNAs) have been found to be regulated by genistein in cancer cells. In this study, we focused on the gene regulatory effect of genistein on microRNA and its target genes in prostate cancer (PC). METHODS: Initially, we investigated the effect of genistein on prostate cancer cells and identified that the expression of miRNA-1260b was decreased by genistein. We performed functional analyses and investigated the relationship between miRNA-1260b expression and prostate cancer patient outcomes. Two target genes (sFRP1 and Smad4) of miR-1260b were identified based on computer algorithm and 3'UTR luciferase assay was carried out to determine direct miRNA regulation of the genes. RESULTS: Genistein promoted apoptosis while inhibiting prostate cancer cell proliferation, invasion and TCF reporter activity in PC cells. MiR-1260b was highly expressed in prostate cancer tissues and significantly downregulated by genistein in PC cells. After knocking down miR-1260b, cell proliferation, invasion, migration and TCF reporter activity were decreased in PC cells. Western analysis and 3'UTR luciferase assay showed that the two target genes (sFRP1 and Smad4) were directly regulated by miR-1260b. The expression of sFRP1 and Smad4 was significantly decreased in prostate cancer tissues. Genistein also increased expression of these two genes via DNA demethylation and histone modifications. CONCLUSIONS: Our data suggest that genistein exerts its anti-tumour effect via downregulation of miR-1260b that targeted sRRP1 and Smad4 genes in prostate cancer cells. The expression of sFRP1 and Smad4 was also modulated by genistein via DNA methylation or histone modifications in PC cell lines.


Assuntos
Metilação de DNA/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Genisteína/farmacologia , Histonas/genética , MicroRNAs/genética , Neoplasias da Próstata/tratamento farmacológico , Proteína Smad4/genética , Anticarcinógenos/farmacologia , Proteínas Mutadas de Ataxia Telangiectasia/biossíntese , Proteínas Mutadas de Ataxia Telangiectasia/genética , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Regulação para Baixo , Histonas/metabolismo , Humanos , Hibridização in Situ Fluorescente , Masculino , MicroRNAs/metabolismo , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Proteína Smad4/biossíntese , Proteína Smad4/metabolismo , Análise Serial de Tecidos , Regulação para Cima/efeitos dos fármacos
9.
Eur J Neurosci ; 40(3): 2471-8, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24827147

RESUMO

Although the accumulation of the neurotoxic peptide ß-amyloid (Aß) in the central nervous system is a hallmark of Alzheimer's disease, whether Aß acts in astrocytes is unclear, and downstream functional consequences have yet to be defined. Here, we show that cytosolic Ca(2+) dysregulation, induced by a neurotoxic fragment (Aß25-35), caused apoptosis in a concentration-dependent manner, leading to cytoplasmic Ca(2+) mobilization from extra- and intracellular sources, mainly from the endoplasmic reticulum (ER) via IP3 receptor activation. This mechanism was related to Aß-mediated apoptosis by the intrinsic pathway because the expression of pro-apoptotic Bax was accompanied by its translocation in cells transfected with GFP-Bax. Aß-mediated apoptosis was reduced by BAPTA-AM, a fast Ca(2+) chelator, indicating that an increase in intracellular Ca(2+) was involved in cell death. Interestingly, the Bax translocation was dependent on Ca(2+) mobilization from IP3 receptors because pre-incubation with xestospongin C, a selective IP3 receptor inhibitor, abolished this response. Taken together, these results provide evidence that Aß dysregulation of Ca(2+) homeostasis induces ER depletion of Ca(2+) stores and leads to apoptosis; this mechanism plays a significant role in Aß apoptotic cell death and might be a new target for neurodegeneration treatments.


Assuntos
Peptídeos beta-Amiloides/farmacologia , Apoptose/efeitos dos fármacos , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Sinalização do Cálcio/efeitos dos fármacos , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , Fragmentos de Peptídeos/farmacologia , Doença de Alzheimer/metabolismo , Animais , Células Cultivadas , Retículo Endoplasmático/efeitos dos fármacos , Retículo Endoplasmático/metabolismo , Ratos , Transdução de Sinais
10.
Br J Cancer ; 108(8): 1659-67, 2013 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-23538390

RESUMO

BACKGROUND: The purpose of this study was to identify prostate cancer (PC) oncogenic microRNAs (miRs) based on miR microarray and to investigate whether these oncogenic miRs may be useful as PC biomarkers. METHODS: Initially, we carried out miR microarray and real-time PCR using RWPE-1, PC-3, DU-145 and LNCaP cells. To investigate the function of miR-183, we used a miR-183 knockdown inhibitor in cell growth and wound-healing assays. We used several algorithms and confirmed that they are directly regulated by miR-183. RESULTS: We identified three potential oncogenic miRs (miR-146a, miR-183 and miR-767-5P). The expression of miR-183 in PC cells (PC-3, DU-145 and LNCaP) was upregulated compared with RWPE-1 cells. MiR-183 expression was also significantly higher in PC tissues compared with that in matched normal prostate tissues. Additionally, miR-183 expression was correlated with higher prostate-specific antigen, higher pT and shorter overall survival. MiR-183 knockdown decreased cell growth and motility in PC cells and significantly decreased prostate tumour growth in in vivo nude mice experiments. We identified Dkk-3 and SMAD4 as potential target genes of miR-183. CONCLUSION: Our data suggest that oncogenic miR-183 may be useful as a new PC biomarker and that inhibition of miR-183 expression may be therapeutically beneficial as a PC treatment.


Assuntos
Peptídeos e Proteínas de Sinalização Intercelular/genética , MicroRNAs/genética , Neoplasias da Próstata/genética , Proteína Smad4/genética , Proteínas Adaptadoras de Transdução de Sinal , Processos de Crescimento Celular/genética , Linhagem Celular Tumoral , Quimiocinas , Técnicas de Silenciamento de Genes , Humanos , Hibridização In Situ , Peptídeos e Proteínas de Sinalização Intercelular/biossíntese , Masculino , MicroRNAs/antagonistas & inibidores , MicroRNAs/biossíntese , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Proteína Smad4/biossíntese , Transfecção , Proteínas Wnt/metabolismo , Via de Sinalização Wnt , beta Catenina/metabolismo
11.
Br J Cancer ; 108(10): 2070-8, 2013 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-23591200

RESUMO

BACKGROUND: Wnt-signalling has an important role in renal cancer and it is modulated by genistein in other cancers. Recently, microRNAs (miRNAs) have emerged as new regulators of gene expression. Thus, we focused on miRNAs to examine the regulatory mechanism of genistein on the Wnt-signalling pathway in renal cell carcinoma (RCC). METHODS: Initially, we investigated the effect of genistein on Wnt-signalling (TOPflash reporter assay (TCF reporter assays)) in renal cancer cells, and using microarray identified candidate miRNAs whose expression was decreased by genistein. We performed functional analyses and investigated the relationship between miRNA expression and renal cancer patient outcomes. We also did 3'UTR luciferase assays to look at direct miRNA regulation of Wnt-signalling-related genes. RESULTS: Genistein promoted apoptosis while inhibiting RCC cell proliferation and invasion. Genistein also decreased TCF reporter activity in RCC cells. We found that miR-1260b was highly expressed and significantly downregulated by genistein in RCC cells. The expression of miR-1260b was significantly higher in renal cancer tissues compared with normal, and significantly related to overall shorter survival. In addition, miR-1260b promoted renal cancer cell proliferation and invasion in RCC cells. The 3'UTR luciferase activity of target genes (sFRP1, Dkk2, Smad4) was significantly decreased and their protein expression significantly upregulated in miR-1260b inhibitor-transfected renal cancer cells. CONCLUSION: Our data suggest that genistein inhibited Wnt-signalling by regulating miR-1260b expression in renal cancer cells.


Assuntos
Carcinoma de Células Renais/genética , Genisteína/farmacologia , Neoplasias Renais/genética , MicroRNAs/genética , Via de Sinalização Wnt/efeitos dos fármacos , Adulto , Idoso , Anticarcinógenos/farmacologia , Carcinoma de Células Renais/metabolismo , Carcinoma de Células Renais/patologia , Proliferação de Células , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/genética , Avaliação Pré-Clínica de Medicamentos , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Neoplasias Renais/metabolismo , Neoplasias Renais/patologia , Masculino , Pessoa de Meia-Idade , Oncogenes/efeitos dos fármacos , Oncogenes/genética , Células Tumorais Cultivadas
13.
Res Vet Sci ; 152: 300-306, 2022 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-36084371

RESUMO

The objective of this study was to investigate the age difference in the response to endotoxin in calves related to the plasma endotoxin activity and mRNA expression of cytokines. Fifteen calves were divided into three groups: control (191 ± 21 days), weaning (162.4 ± 17.5 days), and calf (22.4 ± 8.2 days). The weaning and calf groups received 2.5 µg/kg of ultrapure O111:B4 LPS in 10 mL of each autologous serum, whereas the control calves received a similar volume of saline. Blood samples were collected at 0, 0.5, 1, 2, 4, 8, 12, and 24 h. Liver samples were collected by ultrasound-guided liver biopsy at 0, 2, 4, and 24 h. Plasma endotoxin activity was measured by the limulus amebocyte lysate kinetic turbidimetric assay. The mRNA expression level of GAPDH, TLR-4, NF-κB2, TNF-α, IL-6, and STAT3 in leukocytes and the liver was measured by real-time PCR. Following LPS challenge, the maximal plasma endotoxin activity, and leukocytic expression of TLR4, NF-κB2, TNF-α, and STAT3 were reached at 0.5, 4, 2-4, 2-4, and 4 h, respectively, in weaning and calf groups. The endotoxin activity in calf remained high until 2 h. Furthermore, the expression of leukocytic STAT3 mRNA in calf was not significantly different from the pre-value. In contrast, STAT3 mRNA in weaning markedly increased at 2 and 4 h. Therefore, this study provides new information to the literature of immune and inflammatory responses in calves.


Assuntos
Lipopolissacarídeos , Fator de Necrose Tumoral alfa , Bovinos , Animais , Lipopolissacarídeos/farmacologia , RNA Mensageiro/genética , RNA Mensageiro/análise , Subunidade p52 de NF-kappa B , Endotoxinas , Leucócitos
14.
Br J Cancer ; 104(2): 308-15, 2011 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-21119662

RESUMO

BACKGROUND: The purpose of this study was to identify new tumour suppressor microRNAs (miRs) in clear cell renal cell carcinoma (ccRCC), carry out functional analysis of their suppressive role and identify their specific target genes. METHODS: To explore suppressor miRs in RCC, miR microarray and real-time PCR were performed using HK-2 and A-498 cells. Cell viability, invasion and wound healing assays were carried out for functional analysis after miR transfection. To determine target genes of miR, we used messenger RNA (mRNA) microarray and target scan algorithms to identify target oncogenes. A 3'UTR luciferase assay was also performed. Protein expression of target genes in ccRCC tissues was confirmed by immunohistochemistry and was compared with miR-584 expression in ccRCC tissues. RESULTS: Expression of miR-584 in RCC (A-498 and 769-P) cells was downregulated compared with HK-2 cells. Transfection of miR-584 dramatically decreased cell motility. The ROCK-1 mRNA was inhibited by miR-584 and predicted to be target gene. The miR-584 decreased 3'UTR luciferase activity of ROCK-1 and ROCK-1 protein expression. Low expression of miR-584 in ccRCC tissues was correlated with high expression of ROCK-1 protein. The knockdown of ROCK-1 by siRNA inhibited cell motility. CONCLUSION: miR-584 is a new tumour suppressor miR in ccRCC and inhibits cell motility through downregulation of ROCK-1.


Assuntos
Carcinoma de Células Renais/patologia , Neoplasias Renais/patologia , MicroRNAs/fisiologia , Invasividade Neoplásica/genética , Quinases Associadas a rho/genética , Regiões 3' não Traduzidas , Sequência de Bases , Carcinoma de Células Renais/genética , Linhagem Celular Tumoral , Primers do DNA , Técnicas de Silenciamento de Genes , Humanos , Neoplasias Renais/genética
15.
Clin Exp Allergy ; 41(8): 1133-42, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21429049

RESUMO

BACKGROUND: The pathogenesis of aspirin-induced asthma (AIA) is presumed to involve the aspirin/non-steroidal anti-inflammatory drug (NSAID)-induced abnormal metabolism of arachidonic acid, resulting in an increase in 5-lipoxygenase (5-LO) metabolites, particularly leukotriene C(4) (LTC(4) ). However, the role of LTC(4) in the development of AIA has yet to be conclusively demonstrated. OBJECTIVE: The aim of this study was to evaluate the contribution of the lipid product LTC(4) secreted by the 5-LO pathway to the pathogenesis of AIA. METHODS: To evaluate antigen-induced airway inflammation, the concentrations of T-helper type 2 cytokine in bronchoalveolar lavage fluid (BALF) obtained from LTC(4) synthase-transgenic (Tg) and wild-type (WT) mice after challenge with ovalbumin were measured. Subsequently, the ex vivo and in vivo effects of the NSAID sulpyrine were investigated in these Tg and WT mice by measuring the secretion of LTC(4) from sulpyrine-treated BAL cells and the levels of LTC(4) in BALF following challenge with sulpyrine. Finally, the sulpyrine-induced airway response by the administration of pranlukast, an antagonist of the cysteinyl (cs)-LT1 receptor, was analysed. RESULTS: The concentrations of IL-4, -5, and -13 in BALF from Tg mice were significantly higher than those in WT mice. In addition, sulpyrine augmented the secretion of LTC(4) in BALF and by BAL cells in Tg mice, but not in WT mice. Additionally, the increased airway resistance induced by sulpyrine could be reduced by treatment with pranlukast. Furthermore, the secretion of LTC(4) from mast cells, eosinophils, and macrophages was increased in the allergen-stimulated LTC(4) synthase gene Tg mice, even in the absence of sulpyrine, as well as in BAL cells after sulpyrine. CONCLUSION AND CLINICAL RELEVANCE: The over-expression of the LTC(4) synthase in a mouse asthma model also replicates the key features of AIA. And our study supports that cys-LTs play a major role in the pathogenesis of AIA in patients with chronic asthma.


Assuntos
Asma Induzida por Aspirina/enzimologia , Modelos Animais de Doenças , Glutationa Transferase/genética , Animais , Anti-Inflamatórios não Esteroides/uso terapêutico , Asma Induzida por Aspirina/imunologia , Asma Induzida por Aspirina/metabolismo , Dipirona/uso terapêutico , Glutationa Transferase/metabolismo , Humanos , Leucotrieno C4/análise , Leucotrieno C4/metabolismo , Camundongos , Camundongos Transgênicos , Ovalbumina/efeitos adversos
16.
Clin Exp Allergy ; 41(11): 1568-78, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21801248

RESUMO

BACKGROUND: There is synteny in the CC-type chemokine gene clusters between humans (CCL2/MCP-1, CCL7MCP-3, CCL11/eotaxin, CCL8/MCP-2, CCL13/MCP-4, and CCL1/I-309) and mice (CCL2, CCL7, CCL11, CCL12/MCP-5, CCL8, and CCL1). OBJECTIVE: As many putative Bcl6/STAT-binding sequences are observed in the clusters, we examined the roles of a transcriptional repressor Bcl6 and the regional histone modification in the expression of these chemokine genes in pulmonary epithelium. METHODS: We generated transgenic (Tg) mice carrying the Bcl6 or the dominant-negative (DN)-Bcl6 gene under the control of the surfactant protein C (SPC) promoter that induces the exogenous gene expression in the distal lung epithelium. For in vitro studies, A549, alveolar type II-like epithelial cell line transfected with the SPC-DN-Bcl6 gene were stimulated with IL-4+TNF-α, and Bcl6 or STAT6 binding to and histone modification of the cluster in the transfectants were analysed by chromatin immunoprecipitation assays. Tg mice sensitized with ovalbumin (OVA) were challenged with OVA inhalation. The amounts of mRNAs in each sample were analysed by quantitative RT-PCR. RESULTS: The amount of Bcl6 bound to the cluster decreased in A549 cells stimulated with IL-4 and TNF-α, whereas STAT6 binding increased in association with regional histone H3-K9/14 acetylation and H3-K4 methylation. The expression of all chemokine genes in the gene cluster was augmented in activated A549 cells transfected with the DN-Bcl6 gene. We also induced allergic airway inflammation in Tg mice. Expression of the chemokine genes and infiltrated cell numbers in the lungs of these Tg mice with allergic airway inflammation were inversely correlated with the amount of Bcl6 in the lungs. CONCLUSION AND CLINICAL RELEVANCE: Expression of the pulmonary epithelium-derived CC-type chemokine genes in the cluster is orchestrated by the conserved machinery related to Bcl6. Thus, Bcl6 in pulmonary epithelium may be a critical regulator for pathogenesis of various pulmonary inflammatory diseases.


Assuntos
Quimiocinas CC/genética , Proteínas de Ligação a DNA/metabolismo , Células Epiteliais/metabolismo , Pulmão/metabolismo , Hipersensibilidade Respiratória/genética , Hipersensibilidade Respiratória/imunologia , Animais , Antígenos/imunologia , Sítios de Ligação , Linhagem Celular , Quimiocinas CC/imunologia , Proteínas de Ligação a DNA/genética , Células Epiteliais/imunologia , Expressão Gênica , Regulação da Expressão Gênica , Ordem dos Genes , Histonas/metabolismo , Humanos , Inflamação/genética , Inflamação/imunologia , Pulmão/imunologia , Pulmão/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Ovalbumina/imunologia , Proteínas Proto-Oncogênicas c-bcl-6
17.
Neurochem Res ; 36(5): 829-38, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21347840

RESUMO

Apoptosis is a highly complex form of cell death that can be triggered by alterations in Ca(2+) homeostasis. Members of the Bcl-2 family may regulate apoptosis and modulate Ca(2+) distribution within intracellular compartments. Bax, a proapoptotic member of the family, is constitutively expressed and soluble in the cytosol and, under apoptotic induction, translocates to mitochondrial membranes. However, it is not clear if the intracellular Ca(2+) stores and selective Ca(2+) releases can modulate or control Bax translocation. The aim of this study was to investigate the relation of intracellular Ca(2+) stores with Bax translocation in rat cortical astrocytes. Results show that the classical apoptotic inducer, staurosporine, caused high elevations of cytosolic Ca(2+) that precede Bax translocation. On the other hand, agents that mobilize Ca(2+) from endoplasmic reticulum such as noradrenaline or thapsigargin, induced Bax translocation, while mitochondrial Ca(2+) release evoked by carbonyl cyanide-p-(trifluoromethoxyphenyl) hydrazone was not able to cause Bax punctation. In addition, microinjection of inositol 1,4,5- trisphosphate induced Bax translocation. Taken together, our results show that in Bax overexpressing cortical astrocytes, endoplasmic reticulum-Ca(2+) release may induce Bax transactivation and specifically control apoptosis.


Assuntos
Astrócitos/metabolismo , Cálcio/metabolismo , Córtex Cerebral/metabolismo , Retículo Endoplasmático/metabolismo , Proteína X Associada a bcl-2/metabolismo , Animais , Apoptose , Células Cultivadas , Córtex Cerebral/citologia , Citometria de Fluxo , Microinjeções , Transporte Proteico , Ratos
18.
J Exp Med ; 187(4): 587-600, 1998 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-9463409

RESUMO

Two novel synthetic tetrapeptides, VEID-CHO and DMQD-CHO, could selectively inhibit caspase-6 and caspase-3, respectively. We used these inhibitors to dissect the pathway of caspase activation in Fas-stimulated Jurkat cells and identify the roles of each active caspase in apoptotic processes. Affinity labeling techniques revealed a branched protease cascade in which caspase-8 activates caspase-3 and -7, and caspase-3, in turn, activates caspase-6. Both caspase-6 and -3 have major roles in nuclear apoptosis. Caspase-6 cleaves nuclear mitotic apparatus protein (NuMA) and mediates the shrinkage and fragmentation of nuclei. Caspase-3 cleaves NuMA at sites distinct from caspase-6, and mediates DNA fragmentation and chromatin condensation. It is also involved in extranuclear apoptotic events: cleavage of PAK2, formation of apoptotic bodies, and exposure of phosphatidylserine on the cell surface. In contrast, a caspase(s) distinct from caspase-3 or -6 mediates the disruption of mitochondrial membrane potential (permeability transition) and the shrinkage of cytoplasm. These findings demonstrate that caspases are organized in a protease cascade, and that each activated caspase plays a distinct role(s) in the execution of Fas-induced cell death.


Assuntos
Apoptose , Caspases , Cisteína Endopeptidases/metabolismo , Inibidores de Cisteína Proteinase/farmacologia , Oligopeptídeos/farmacologia , Receptor fas/fisiologia , Antígenos Nucleares , Autoantígenos/metabolismo , Caspase 3 , Caspase 6 , Caspase 7 , Caspase 8 , Caspase 9 , Proteínas de Ciclo Celular , Fragmentação do DNA , Ativação Enzimática , Citometria de Fluxo , Humanos , Células Jurkat , Proteínas Associadas à Matriz Nuclear , Proteínas Nucleares/metabolismo , Fuso Acromático/metabolismo
19.
Eur J Neurosci ; 32(1): 60-70, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20608968

RESUMO

Huntington's disease is a neurodegenerative disorder caused by an expansion of CAGs repeats and characterized by alterations in mitochondrial functions. Although changes in Ca(2+) handling have been suggested, the mechanisms involved are not completely understood. The aim of this study was to investigate the possible alterations in Ca(2+) handling capacity and the relationship with mitochondrial dysfunction evaluated by NAD(P)H fluorescence, reactive oxygen species levels, mitochondrial membrane potential (DeltaPsi(m)) measurements and respiration in whole brain slices from R6/1 mice of different ages, evaluated in situ by real-time real-space microscopy. We show that the cortex and striatum of the 9-month-old R6/1 transgenic mice present a significant sustained increase in cytosolic Ca(2+) induced by glutamate (Glu). This difference in Glu response was partially reduced in R6/1 when in the absence of extracellular Ca(2+), indicating that N-methyl-D-aspartate receptors participation in this response is more important in transgenic mice. In addition, Glu also lead to a decrease in NAD(P)H fluorescence, a loss in DeltaPsi(m) and a further increase in respiration, which may have evoked a decrease in mitochondrial Ca(2+) Ca(2+)(m) uptake capacity. Taken together, these results show that alterations in Ca(2+) homeostasis in transgenic mice are associated with a decrease in Ca(2+)(m) uptake mechanism with a diminished Ca(2+) handling ability that ultimately causes dysfunctions and worsening of the neurodegenerative and the disease processes.


Assuntos
Encéfalo/metabolismo , Sinalização do Cálcio/fisiologia , Cálcio/metabolismo , Ácido Glutâmico/metabolismo , Mitocôndrias/metabolismo , Animais , Encéfalo/anatomia & histologia , Carbonil Cianeto p-Trifluormetoxifenil Hidrazona/metabolismo , Inibidores Enzimáticos/metabolismo , Homeostase , Humanos , Doença de Huntington/fisiopatologia , Masculino , Potencial da Membrana Mitocondrial/fisiologia , Camundongos , Camundongos Transgênicos , NADP/metabolismo , Consumo de Oxigênio/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Tapsigargina/metabolismo , Desacopladores/metabolismo
20.
Br J Cancer ; 101(8): 1374-81, 2009 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-19773752

RESUMO

BACKGROUND: The canonical Wnt signalling pathway is activated in most sporadic colorectal cancers (CRCs). We previously reported that FZD7 functions as a receptor for the canonical Wnt signalling pathway in colon cancer cells. METHODS AND RESULTS: In this study, we examined the function of FZD7 in survival, invasion and metastatic capabilities of colon cancer cells. FZD7_siRNA transfection decreased cell viability of HT-29 and HCT-116 colon cancer cells. Expression of c-Jun, phosphorylation of JNK and c-Jun, and activation of RhoA were suppressed after FZD7_siRNA transfection into HCT-116 cells. In vitro invasion activity and Wnt target gene expression were also reduced in HCT-116 cells transfected with FZD7_siRNA. Liver metastasis of stable FZD7_siRNA HCT-116 cell transfectants in scid mice was decreased to 40-50% compared to controls. The mRNA levels of FZD7 in 135 primary CRC tissues were examined by real-time PCR. FZD7 mRNA levels were significantly higher in stage II, III or IV tumours than in non-tumour tissues (P<0.005), and overall survival was shorter in those patients with higher FZD7 expression (P<0.001). CONCLUSION: These data suggest that FZD7 may be involved in enhancement of survival, invasion and metastatic capabilities of colon cancer cells through non-canonical Wnt signalling pathways as well as the canonical pathway.


Assuntos
Neoplasias Colorretais/patologia , Receptores Frizzled/fisiologia , Receptores Acoplados a Proteínas G/fisiologia , Animais , Sobrevivência Celular , Receptores Frizzled/antagonistas & inibidores , Receptores Frizzled/genética , Células HCT116 , Células HT29 , Humanos , Neoplasias Hepáticas Experimentais/secundário , Camundongos , Camundongos SCID , Invasividade Neoplásica , RNA Mensageiro/análise , RNA Interferente Pequeno/genética , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Receptores Acoplados a Proteínas G/genética
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