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










Base de dados
Intervalo de ano de publicação
1.
Biomolecules ; 9(8)2019 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-31366115

RESUMO

In the silkworm, the sex-determination primary signal Fem controls sex differentiation by specific binding of Fem-derived piRNA to the cleavage site in Masc mRNA, thus inhibiting Masc protein production in the female. In this study, we identified a novel splicing isoform of Masc, named Masc-S, which lacks the intact sequence of the cleavage site, encoding a C-terminal truncated protein. Results of RT-PCR showed that Masc-S was expressed in both sexes. Over-expression of Masc-S and Masc in female-specific cell lines showed that Masc-S could be translated against the Fem-piRNA cut. By RNA-protein pull-down, LC/MS/MS, and EMSA, we identified a protein BmEXU that specifically binds to an exclusive RNA sequence in Masc compared to Masc-S. Knockdown of Masc-S resulted in abnormal morphology in female external genital and increased expression of the Hox gene Abd-B, which similarly occurred by Bmexu RNAi. These results suggest that the splice variant Masc-S against Fem-piRNA plays an important role in female external genital development, of which function is opposite to that of full-length Masc. Our study provides new insights into the regulatory mechanism of sex determination in the silkworm.

2.
Int J Mol Sci ; 20(9)2019 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-31086020

RESUMO

Bombyx mori doublesex (Bmdsx) functions as a double-switch gene in the final step of the sex-determination cascade in the silkworm Bombyx mori. The P-element somatic inhibitor (PSI) protein in B. mori interacts with Bmdsx pre-mRNA in CE1 as an exonic splicing silencer to promote male-specific splicing of Bmdsx. However, the character of the interaction between BmPSI and Bmdsx pre-mRNA remains unclear. Electrophoretic mobility shift assay (EMSA) results showed that the four KH_1 motifs in BmPSI are all essential for the binding, especially the former two KH_1 motifs. Three active sites (I116, L127, and IGGI) in the KH_1 motif were found to be necessary for the binding through EMSA, circular dichroism (CD) spectroscopy, and isothermal titration calorimetry (ITC). The PSI homologous protein in S. litura (SlPSI) was purified and the binding of SlPSI and CE1 was verified. Compared with BmPSI, the mutant SlPSI proteins of I116 and IGGI lost their ability to bind to CE1. In conclusion, the binding of PSI and dsx pre-mRNA are generally conserved in both B. mori and S. litura. These findings provide clues for sex determination in Lepidoptera.


Assuntos
Bombyx/genética , Proteínas de Insetos/genética , Processamento de RNA/genética , Spodoptera/genética , Processamento Alternativo/genética , Animais , Varredura Diferencial de Calorimetria , Dicroísmo Circular , Ensaio de Desvio de Mobilidade Eletroforética , Éxons/genética , Feminino , Masculino , Ligação Proteica
3.
Oncotarget ; 8(44): 76468-76478, 2017 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-29100326

RESUMO

Objective: To evaluate the effects of fiber-modified hexon-chimeric recombinant oncolytic adenovirus targeting cancer associated fibroblasts (CAFs) on the gastric CAFs and the transplantation tumor mice model of gastric carcinoma (GC). Results: Compared with BJ cells and GPFs, the reproduction and infectivity of P9, P9-4C or GP adenoviruses were markedly higher in gastric CAFs. In addition, P9, P9-4C or GP had a significantly relatively more killing effect on gastric CAFs compared with GPFs, and have less oncolytic effect in BJ cells. Furthermore, in transplantation tumor mice model of GC we found significantly higher hexon protein expression in tumor tissues, more decreasing tumor growth and increasing inhibitory rates after treatment of P9, P9-4C or GP adenoviruses compared with Ad adenovirus. Materials and Methods: Based on the construction of the recombinant oncolytic adenoviruses pRCAdHVR48-SDF1p-Ad/EGFP (Ad, as control) with the E1A gene transcription regulated by stromal-derived factor 1 (SDF1) promoter and the hexon replaced by hexon-chimeric (H5HVR48) gene, three fiber-modified hexon-chimeric oncolytic adenovirus through the modification fiber protein by insertion of different short peptides specifically binding to fibroblast activation protein (FAP), including pRCAdHVR48-SDF1p-FAP-P9/EGFP (P9), pRCAdHVR48-SDF1p-FAP-P9-4C/EGFP (P9-4C), pRCAdHVR48-SDF1p-FAP-GP/EGFP (GP), and their corresponding replication-defective adenovirus in parallel were reconstructed. Then the reproduction, infectivity and killing ability of the four above recombinant adenoviruses were evaluated in gastric CAFs compared with gastric para-mucosa fibroblasts (GPFs) and neonatal human foreskin fibroblasts (BJ). Furthermore, transplantation tumor mice model of GC was established, and then treated by the four above recombinant adenoviruses. Tumor size and tumor growth inhibitory rates were calculated, and histomorphology by HE staining and hexon expressions by immunohistochemistry were evaluated in tumor tissues. Conclusions: The fiber-modified hexon-chimeric recombinant oncolytic adenovirus targeting CAFs can relatively specifically kill gastric CAFs and inhibit GC cells growth in vivo.

4.
J Hypertens ; 35(6): 1195-1203, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28319593

RESUMO

BACKGROUND: Long noncoding RNAs (lncRNAs) are being discovered in multiple diseases at a rapid pace. However, the contribution of lncRNAs to hypertension remains largely unknown. In hypertension, the vascular walls are exposed to abnormal mechanical cyclic strain, which leads to vascular remodelling. Here, we investigated the mechanobiological role of lncRNAs in hypertension. METHODS AND RESULTS: Differences in the lncRNAs and mRNAs between spontaneously hypertensive rats and Wistar-Kyoto rats were screened using a gene microarray. The results showed that 68 lncRNAs and 255 mRNAs were upregulated in the aorta of spontaneously hypertensive rats, whereas 167 lncRNAs and 272 mRNAs were downregulated. Expressions of the screened lncRNAs, including XR007793, were validated by real-time PCR. A coexpression network was composed, and gene function was analysed using Ingenuity Pathway Analysis. In vitro, vascular smooth muscle cells (VSMCs) were subjected to cyclic strain at a magnitude of 5 (physiological normotensive cyclic strain) or 15% (pathological hypertensive cyclic strain) by Flexcell-4000T. A total of 15% cyclic strain increased XR007793 expression. XR007793 knockdown attenuated VSMC proliferation and migration and inhibited coexpressed genes such as signal transducers and activators of transcription 2 (stat2), LIM domain only 2 (lmo2) and interferon regulatory factor 7 (irf7). CONCLUSION: The profile of lncRNAs was varied in response to hypertension, and pathological elevated cyclic strain may play crucial roles during this process. Our data revealed a novel mechanoresponsive lncRNA-XR007793, which modulates VSMC proliferation and migration, and participates in vascular remodelling during hypertension.


Assuntos
Aorta/metabolismo , Hipertensão/metabolismo , Músculo Liso Vascular/metabolismo , RNA Longo não Codificante/metabolismo , RNA Mensageiro/metabolismo , Animais , Células Cultivadas , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Masculino , Músculo Liso Vascular/citologia , Análise de Sequência com Séries de Oligonucleotídeos , RNA Longo não Codificante/análise , RNA Mensageiro/análise , Ratos , Ratos Endogâmicos SHR , Ratos Wistar , Reação em Cadeia da Polimerase em Tempo Real , Análise de Sequência de RNA
5.
Cardiovasc Res ; 113(5): 488-497, 2017 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-28137944

RESUMO

Aims: Mechanical factors play significant roles in neointimal hyperplasia after vein grafting, but the mechanisms are not fully understood. Here, we investigated the roles of microRNA-33 (miR-33) in neointimal hyperplasia induced by arterial mechanical stretch after vein grafting. Methods and results: Grafted veins were generated by the 'cuff' technique. Neointimal hyperplasia and cell proliferation was significantly increased, and miR-33 expression was decreased after 1-, 2-, and 4-week grafts. In contrast, the expression of bone morphogenetic protein 3 (BMP3), which is a putative target of miR-33, and the phosphorylation of smad2 and smad5, which are potential downstream targets of BMP3, were increased in the grafted veins. miR-33 mimics/inhibitor and dual luciferase reporter assay confirmed the interaction of miR-33 and BMP3. miR-33 mimics attenuated, while miR-33 inhibitor accelerated, proliferation of venous smooth muscle cells (SMCs). Moreover, recombinant BMP3 increased SMC proliferation and P-smad2 and P-smad5 levels, whereas BMP3-directed siRNAs had the opposite effect. Then, venous SMCs were exposed to a 10%-1.25 Hz cyclic stretch (arterial stretch) by using the FX4000 cyclic stretch loading system in vitro to mimic arterial mechanical conditions. The arterial stretch increased venous SMC proliferation and repressed miR-33 expression, but enhanced BMP3 expression and smad2 and smad5 phosphorylation. Furthermore, perivascular multi-point injection in vivo demonstrated that agomiR-33 not only attenuates BMP3 expression and smad2 and smad5 phosphorylation, but also slows neointimal formation and cell proliferation in grafted veins. These effects of agomiR-33 on grafted veins could be reversed by local injection of BMP3 lentivirus. Conclusion: The miR-33-BMP3-smad signalling pathway protects against venous SMC proliferation in response to the arterial stretch. miR-33 is a target that attenuates neointimal hyperplasia in grafted vessels and may have potential clinical applications.


Assuntos
Proliferação de Células , Veias Jugulares/metabolismo , Veias Jugulares/transplante , Mecanotransdução Celular , MicroRNAs/metabolismo , Neointima , Regiões 3' não Traduzidas , Animais , Antagomirs/genética , Antagomirs/metabolismo , Sítios de Ligação , Proteína Morfogenética Óssea 3/genética , Proteína Morfogenética Óssea 3/metabolismo , Células Cultivadas , Hiperplasia , Veias Jugulares/patologia , Masculino , MicroRNAs/genética , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/patologia , Músculo Liso Vascular/transplante , Miócitos de Músculo Liso/metabolismo , Miócitos de Músculo Liso/patologia , Miócitos de Músculo Liso/transplante , Fosforilação , Interferência de RNA , Ratos Sprague-Dawley , Proteína Smad2/metabolismo , Proteína Smad5/metabolismo , Estresse Mecânico , Fatores de Tempo , Transfecção
6.
Sci Rep ; 7: 41058, 2017 01 20.
Artigo em Inglês | MEDLINE | ID: mdl-28106155

RESUMO

Abnormal proliferation of endothelial cells (ECs) is important in vascular remodeling during hypertension, but the mechanisms are still unclear. In hypertensive rats caused by abdominal aortic coarctation, the expression of G-protein-coupled receptor kinase 6 (GRK6) in ECs at common carotid artery was repressed in vivo, and EC proliferation was increased. 15% cyclic stretch in vitro, which mimics the pathologically increased stretch in hypertension, repressed EC GRK6 expression via paracrine control by vascular smooth muscle cells (VSMCs). Furthermore, VSMC-derived microparticles (VSMC-MPs) were detected in the conditioned medium from VSMCs and in artery. VSMC-MPs from cells exposed to 15% cyclic stretch decreased GRK6 expression and increased EC proliferation. miR-27a was detected in VSMC-MPs and was upregulated by 15% cyclic stretch. miR-27a was transferred from VSMCs to ECs via VSMC-MPs and directly targeted on GRK6. Finally, a multi-point injection of antagomiR-27a around carotid artery decreased miR-27a expression in vivo, induced GRK6 expression, and reversed the abnormal EC proliferation. Pathologically elevated cyclic stretch increased the secretion of miR-27a, which was transferred from VSMCs to ECs via the VSMC-MPs, subsequently targeted GRK6, and induced EC proliferation. Locally decreasing miR-27a could be a novel therapeutic approach to attenuate the abnormal EC proliferation in hypertension.


Assuntos
Proliferação de Células , Células Endoteliais/metabolismo , Quinases de Receptores Acoplados a Proteína G/metabolismo , Hipertensão/metabolismo , MicroRNAs/metabolismo , Animais , Modelos Animais de Doenças , Masculino , Músculo Liso Vascular/citologia , Músculo Liso Vascular/metabolismo , Comunicação Parácrina , Estimulação Física , Ratos Sprague-Dawley
7.
Gastrointest Endosc ; 76(5): 945-52, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22841501

RESUMO

BACKGROUND: Celiac plexus neurolysis for the palliative reduction of pain in unresectable pancreatic carcinoma (PC) is safe but provides limited relief. In a previous study, we found that EUS-guided implantation of iodine-125 ((125)I) around the celiac ganglia is a safe procedure and can induce apoptosis of local neurons in a porcine model. OBJECTIVE: To evaluate the safety and efficacy of direct celiac ganglion irradiation with (125)I seeds for the relief of moderate to severe pain secondary to unresectable PC. DESIGN: Prospective study. SETTING: Single, tertiary care referral center. PATIENTS: This study enrolled consecutive patients who had moderate to severe pain resulting from biopsy-proven unresectable PC. INTERVENTION: All patients underwent EUS-guided direct celiac ganglion irradiation with (125)I seeds. Follow-up was conducted at least once weekly until death. MAIN OUTCOME MEASUREMENTS: Blood parameters, Visual Analog Scale (VAS) score, mean analgesic (MS Contin [morphine sulfate]) consumption, and complications were evaluated during follow-up. RESULTS: Twenty-three patients with unresectable PC underwent the procedure. The mean number of seeds implanted in the celiac ganglion per patient was 4 (range 2-6). Immediately after the procedure, pain relief and analgesic consumption showed no significant changes compared with preoperative values. Six patients (26%) reported pain exacerbation. Two weeks later, the VAS score and mean analgesic consumption were significantly less than preoperative values. No procedure-related deaths or major complications occurred. LIMITATIONS: Uncontrolled study. CONCLUSIONS: EUS-guided direct celiac ganglion irradiation with (125)I seeds can reduce the VAS score and analgesic drug consumption in patients with unresectable PC.


Assuntos
Carcinoma/complicações , Radioisótopos do Iodo/uso terapêutico , Dor/radioterapia , Neoplasias Pancreáticas/complicações , Adulto , Idoso , Analgésicos Opioides/administração & dosagem , Braquiterapia/efeitos adversos , Endossonografia , Feminino , Gânglios Simpáticos/diagnóstico por imagem , Humanos , Radioisótopos do Iodo/efeitos adversos , Masculino , Pessoa de Meia-Idade , Morfina/administração & dosagem , Dor/tratamento farmacológico , Dor/etiologia , Medição da Dor , Projetos Piloto , Ultrassonografia de Intervenção
8.
Pancreas ; 41(5): 712-6, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22481292

RESUMO

OBJECTIVES: There have been few reports regarding the incidence of hyperamylasemia after endoscopic ultrasound-guided fine needle aspiration (EUS-FNA). In particular, the potential risk factors involved in the development of hyperamylasemia have not been analyzed owing to the small number of cases reported. The aim of this study was to evaluate hyperamylasemia and associated risk factors after EUS-FNA of a large sample of pancreatic lesions. METHODS: Patients who underwent EUS-FNA for treatment of a pancreatic lesion were recruited from 6 medical centers in China. RESULTS: A total of 1023 patients presenting with pancreatic lesions between January 2004 and June 2008 were enrolled in this study, with 48 (4.7%) of the 1023 patients presenting with hyperamylasemia 3 hours after the procedure. These patients had a mean ± SD serum amylase level of 331.64 ± 138.60 UI/L. With the use of unconditional logistic regression analysis, the incidence of hyperamylasemia was found to be affected by the type of cystic lesion present and the gauge of the needle used. In 4 (0.4%) of the 1023 patients, acute pancreatitis developed. CONCLUSIONS: The overall incidence of hyperamylasemia after EUS-FNA is relatively low. However, the type of cystic lesion present and the gauge of the needle (19G) used for EUS-FNA may represent risk factors for the incidence of hyperamylasemia.


Assuntos
Biópsia por Agulha Fina/efeitos adversos , Hiperamilassemia/etiologia , Pâncreas/patologia , Pancreatopatias/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia por Agulha Fina/métodos , China/epidemiologia , Endossonografia , Feminino , Humanos , Hiperamilassemia/epidemiologia , Incidência , Masculino , Pessoa de Meia-Idade , Pâncreas/diagnóstico por imagem , Pancreatopatias/diagnóstico por imagem , Medição de Risco , Fatores de Risco
9.
Gastrointest Endosc ; 73(2): 283-90, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21295642

RESUMO

BACKGROUND: EUS-guided FNA (EUS-FNA) permits both morphologic and cytologic analysis of lesions within or adjacent to the GI tract. Although previous studies have evaluated the accuracy of EUS-FNA, little is known about the complications of EUS-FNA. Moreover, the frequency and severity of complications may vary from center to center and may be related to differences in individual experience. OBJECTIVE: To systematically review the morbidity and mortality associated with EUS-FNA. DESIGN: MEDLINE and EMBASE were searched to identify relevant English-language articles. MAIN OUTCOME MEASUREMENTS: EUS-FNA-specific morbidity and mortality rates. RESULTS: We identified 51 articles with a total of 10,941 patients who met our inclusion and exclusion criteria; the overall rate of EUS-FNA-specific morbidity was 0.98% (107/10,941). In the small proportion of patients with complications of any kind, the rates of pancreatitis (36/8246; 0.44%) and postprocedure pain (37/10,941; 0.34%) were 33.64% (36/107) and 34.58% (37/107), respectively. The mortality rate attributable to EUS-FNA-specific morbidity was 0.02% (2/10,941). Subgroup analysis showed that the morbidity rate was 2.44% in prospective studies compared with 0.35% in retrospective studies for pancreatic mass lesions (P=.000), whereas it was 2.33% versus 5.07% for pancreatic cysts (P=.036). LIMITATIONS: Few articles reported well-designed, prospective studies and few focused on overall complications after EUS-FNA. CONCLUSIONS: EUS-FNA-related morbidity and mortality rates are relatively low, and most associated events are mild to moderate in severity.


Assuntos
Biópsia por Agulha Fina/efeitos adversos , Doenças do Sistema Digestório/epidemiologia , Endossonografia/efeitos adversos , Biópsia por Agulha Fina/métodos , Doenças do Sistema Digestório/diagnóstico por imagem , Doenças do Sistema Digestório/patologia , Saúde Global , Humanos , Morbidade/tendências , Fatores de Risco , Taxa de Sobrevida/tendências
10.
Zhongguo Dang Dai Er Ke Za Zhi ; 12(2): 96-8, 2010 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-20199720

RESUMO

OBJECTIVE: To assess bone health in epileptic children who have been treated with topiramate (TPM) or carbamazepine (CBZ). METHODS: Sixty-three epileptic children who received TPM or CBZ treatment and 36 eileptic children who did not receive any drug treatment (control group) were enrolled. Bone mineral density (BMD) at lumbar vertebrae (L1-L4) and radius-ulna was evaluated by the dual-energy X-ray absorptiometry method. Biochemical indices of bone metabolism, including serum calcium, phosphorus and alkaline phosphatase contents were measured. RESULTS: The serum calcium content was higher in the TPM group (2.41+/-0.17 mmol/L), but it was lower in the CBZ group (2.15+/-0.26 mmol/L) than that (2.26+/-0.11 mmol/L) in the control group (p<0.05). The serum phosphorus content in both the TPM (1.55+/-0.17 mmol/L) and the CBZ groups (1.52+/-0.26 mmol/L) was significantly lower than that in the control group (1.70+/-0.30 mmol/L) (p<0.05). There were no significant differences in the serum content of alkaline phosphatase between three groups. BMD was significantly reduced in both the TPM and the CBZ groups when compared to the control group (p<0.05). CONCLUSIONS: TPM and CBZ may result in alterations in serum contents of calcium, phosphorus and alkaline phosphatase as well as BMD reduction.


Assuntos
Anticonvulsivantes/efeitos adversos , Osso e Ossos/efeitos dos fármacos , Carbamazepina/efeitos adversos , Epilepsia/tratamento farmacológico , Frutose/análogos & derivados , Adolescente , Fosfatase Alcalina/sangue , Densidade Óssea/efeitos dos fármacos , Osso e Ossos/metabolismo , Cálcio/sangue , Criança , Pré-Escolar , Epilepsia/metabolismo , Feminino , Frutose/efeitos adversos , Humanos , Masculino , Fósforo/sangue , Topiramato
11.
Biochem Pharmacol ; 75(4): 92017 Apr, 2008 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-18053965

RESUMO

Because NMDA complex and mitochondrial function are related, we hypothesized memantine would influence mitochondrial function. We addressed this in vitro by studying the effects of chronic and acute memantine exposures on mitochondrial function. For acute exposure experiments, mitochondria were isolated from NT2 cells and assayed for electron transport chain (ETC) enzyme function and peroxide production in buffers containing up to 60uM memantine. For chronic exposure experiments, NT2 cells were maintained for at least two weeks in medium containing up to 60uM memantine, following which we assayed cells or their mitochondria for ETC enzyme activities, cytochrome oxidase protein levels, oxidative stress, calcium levels, and mitochondrial DNA levels. The ability of the NMDA receptor antagonist aminophosphonovaleric acid (APV) to modify memantine's mitochondrial effects was evaluated. Acute and chronic memantine similarly affected complex I (increased at high concentrations) and IV (decreased at high concentrations) V(max) activities. APV did not alter the effects of chronic memantine exposure on citrate synthase and complex IV. We detected a lower mitochondrial peroxide production rate with acute exposure, and an increased mitochondrial peroxide production rate with chronic exposure. Micromolar memantine concentrations affect mitochondria, some of these effects are directly mediated, and acute and chronic effects may differ.


Assuntos
Memantina/farmacologia , Mitocôndrias/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Cálcio/metabolismo , Linhagem Celular Tumoral , Citrato (si)-Sintase/metabolismo , Relação Dose-Resposta a Droga , Transporte de Elétrons , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Humanos , Mitocôndrias/enzimologia , Mitocôndrias/metabolismo , Consumo de Oxigênio/efeitos dos fármacos
12.
Mol Pharmacol ; 71(6): 1695-702, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17387142

RESUMO

Thiazolidinediones alter cell energy metabolism. They are used to treat or are being considered for the treatment of disorders that feature mitochondrial impairment. Their mitochondrial effects, however, have not been comprehensively studied under long-term exposure conditions. We used the human neuron-like NT2 cell line to directly assess the long-term effects of a thiazolidinedione drug, pioglitazone, on mitochondria. At micromolar concentrations, pioglitazone increased mitochondrial DNA (mtDNA) content, levels of mtDNA and nuclear-encoded electron transport chain subunit proteins, increased oxygen consumption, and elevated complex I and complex IV V(max) activities. Pioglitazone treatment was also associated with increased cytoplasmic but reduced mitochondrial peroxide levels. Our data suggest that pioglitazone induces mitochondrial biogenesis and show that pioglitazone reduces mitochondrial oxidative stress in a neuron-like cell line. For these reasons pioglitazone may prove useful in the treatment of mitochondriopathies.


Assuntos
Mitocôndrias/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Tiazolidinedionas/farmacologia , Linhagem Celular , Respiração Celular/efeitos dos fármacos , DNA Mitocondrial , Transporte de Elétrons/efeitos dos fármacos , Humanos , Mitocôndrias/fisiologia , Neurônios/citologia , Neurônios/fisiologia , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Pioglitazona , Espécies Reativas de Oxigênio/metabolismo
13.
J Neurosci Res ; 78(3): 420-9, 2004 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-15389841

RESUMO

In addition to minimizing native and non-native protein aggregations, heat shock proteins (HSPs) regulate programmed cell death pathways. Members of this conserved protein family are in general activated by oxidative stress, and likely help maintain viability under this stress condition. To further our understanding of heat shock protein physiology, we studied whether a specific subtype of oxidative stress, namely that arising from mitochondrial electron transport chain inhibition, induced a heat shock protein response. We exposed human teratocarcinoma (NT2) cells to varying concentrations of the cytochrome oxidase inhibitor sodium azide. Micromolar exposures resulted in a cytoplasm to nucleus translocation of the inducible Hsp70 and of Hsp40, and this was followed by an overall upregulation. The response did not coincide temporally with the onset of azide exposure, but rather was activated when the degree of cytochrome oxidase inhibition (which was progressive over time) surpassed a threshold. Azide did not affect either Hsp70 or Hsp40 dynamics in NT2 rho0 cells, which lack functional electron transport chains. For the azide-exposed native cell line, addition of the antioxidant trolox to the medium abrogated both Hsp70/Hsp40 translocation and upregulation. We conclude that mitochondrial electron transport chain dysfunction activates a heat shock protein response, and that this response is mediated by oxidative stress.


Assuntos
Proteínas de Choque Térmico/metabolismo , Resposta ao Choque Térmico/efeitos dos fármacos , Mitocôndrias/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Azida Sódica/farmacologia , Western Blotting/métodos , Linhagem Celular Tumoral , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Cromanos/farmacologia , Citoplasma/efeitos dos fármacos , Citoplasma/metabolismo , Relação Dose-Resposta a Droga , Interações de Medicamentos , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Inibidores Enzimáticos/farmacologia , Proteínas de Choque Térmico HSP40 , Proteínas de Choque Térmico HSP70/metabolismo , Proteínas de Choque Térmico/classificação , Humanos , Peróxido de Hidrogênio/metabolismo , Imuno-Histoquímica/métodos , Estresse Oxidativo/fisiologia , Teratocarcinoma , Fatores de Tempo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA