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1.
Front Cell Dev Biol ; 11: 1163400, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37009471

RESUMO

Preterm cerebral white matter injury (WMI), a major form of prenatal brain injury, may potentially be treated by oligodendrocyte (OL) precursor cell (OPC) transplantation. However, the defective differentiation of OPCs during WMI seriously hampers the clinical application of OPC transplantation. Thus, improving the ability of transplanted OPCs to differentiate is critical to OPC transplantation therapy for WMI. We established a hypoxia-ischemia-induced preterm WMI model in mice and screened the molecules affected by WMI using single-cell RNA sequencing. We revealed that endothelin (ET)-1 and endothelin receptor B (ETB) are a pair of signaling molecules responsible for the interaction between neurons and OPCs and that preterm WMI led to an increase in the number of ETB-positive OPCs and premyelinating OLs. Furthermore, the maturation of OLs was reduced by knocking out ETB but promoted by stimulating ET-1/ETB signaling. Our research reveals a new signaling module for neuron-OPC interaction and provides new insight for therapy targeting preterm WMI.

2.
J Thromb Haemost ; 21(5): 1336-1351, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36792011

RESUMO

BACKGROUND: Severe fever with thrombocytopenia syndrome (SFTS) virus (SFTSV) infection causes an emerging hemorrhagic fever in East Asia with a high mortality rate. Thrombocytopenia is a consistent feature of SFTS illness, but the mechanism remains elusive. OBJECTIVES: We aimed to better understand the role of platelets in the pathophysiology of SFTSV infection, including the development of thrombocytopenia. METHODS: Using platelets from healthy volunteers and patients with SFTS, we evaluated the functional changes in platelets against SFTSV infection. We investigated the direct effect of glycoprotein VI on platelet-SFTSV interaction by quantitative real-time PCR, molecular docking, surface plasmon resonance spectrometry, flow cytometry, western blot, and platelet functional studies in vitro. Interactions of SFTSV and platelet-SFTSV complexes with macrophages were also determined by scanning electron microscope, quantitative real-time PCR, and flow cytometry. RESULTS: This study is the first to demonstrate that platelets are capable of harboring and producing SFTSV particles. Structural and functional studies found that SFTSVs bind platelet glycoprotein VI to potentiate platelet activation, including platelet aggregation, adenosine triphosphate release, spreading, clot retraction, coagulation, phosphatidylserine exposure, thrombus formation, and adherence. In vitro mechanistic studies highlighted that the interaction of platelets with human THP-1 cells promoted SFTSV clearance and suppressed cytokine production in macrophages. However, unwanted SFTSV replication in macrophages reciprocally aggravated SFTSV persistence in the circulation, which may contribute to thrombocytopenia and other complications during SFTSV infection. CONCLUSION: These findings together highlighted the pathophysiological role of platelets in initial intrinsic defense against SFTSV infections, as well as intertwined processes with host immunity, which can also lead to thrombocytopenia and poor prognosis.


Assuntos
Infecções por Bunyaviridae , Febre Grave com Síndrome de Trombocitopenia , Trombocitopenia , Humanos , Plaquetas , Febre Grave com Síndrome de Trombocitopenia/complicações , Infecções por Bunyaviridae/complicações , Simulação de Acoplamento Molecular , Trombocitopenia/complicações , Ativação Plaquetária
4.
BMC Microbiol ; 21(1): 245, 2021 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-34511061

RESUMO

BACKGROUND: Bacterial abortive infection (Abi) systems are type IV toxin-antitoxin (TA) system, which could elicit programmed cell death and constitute a native survival strategy of pathogenic bacteria under various stress conditions. However, no rhizobial AbiE family TA system has been reported so far. Here, a M. huakuii AbiE TA system was identified and characterized. RESULTS: A mutation in M. huakuii abiEi gene, encoding an adjacent GntR-type transcriptional regulator, was generated by homologous recombination. The abiEi mutant strain grew less well in rich TY medium, and displayed increased antioxidative capacity and enhanced gentamicin resistance, indicating the abiEi operon was negatively regulated by the antitoxin AbiEi in response to the oxidative stress and a particular antibiotic. The mRNA expression of abiEi gene was significantly up-regulated during Astragalus sinicus nodule development. The abiEi mutant was severely impaired in its competitive ability in rhizosphere colonization, and was defective in nodulation with 97% reduction in nitrogen-fixing capacity. The mutant infected nodule cells contained vacuolation and a small number of abnormal bacteroids with senescence character. RNA-seq experiment revealed it had 5 up-regulated and 111 down-regulated genes relative to wild type. Of these down-regulated genes, 21 are related to symbiosis nitrogen fixation and nitrogen mechanism, 16 are involved in the electron transport chain and antioxidant responses, and 12 belong to type VI secretion system (T6SS). CONCLUSIONS: M. huakuii AbiEi behaves as a key transcriptional regulator mediating root nodule symbiosis.


Assuntos
Proteínas de Bactérias/genética , Regulação Bacteriana da Expressão Gênica/genética , Mesorhizobium/genética , Nodulação , Estresse Fisiológico/genética , Fatores de Transcrição/genética , Astrágalo/microbiologia , Proteínas de Bactérias/metabolismo , Estresse Oxidativo , Fatores de Transcrição/metabolismo
5.
J Proteome Res ; 20(5): 2329-2339, 2021 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-33797919

RESUMO

The mammalian target of rapamycin (mTOR) functions as a critical regulator of cell cycle progression. However, the underlying mechanism by which mTOR regulates cell cycle progression remains elusive. In this study, we used stable isotope labeling of amino acids in cell culture with a two-step strategy for phosphopeptide enrichment and high-throughput quantitative mass spectrometry to perform a global phosphoproteome analysis of mTOR inhibition by rapamycin. By monitoring the phosphoproteome alterations upon rapamycin treatment, downregulation of mTOR signaling pathway was detected and enriched. Further functional analysis of phosphoproteome revealed the involvement of cell cycle events. Specifically, the elevated profile of cell cycle-related substrates was observed, and the activation of CDK1, MAPK1, and MAPK3 kinases was determined. Second, pathway interrogation using kinase inhibitor treatment confirmed that CDK1 activation operated downstream from mTOR inhibition to further regulate cell cycle progression. Third, we found that the activation of CDK1 following 4-12 h of mTOR inhibition was accompanied by the activation of the Greatwall-endosulfine complex. In conclusion, we presented a high-confidence phosphoproteome map inside the cells upon mTOR inhibition by rapamycin. Our data implied that mTOR inhibition could contribute to CDK1 activation for further regulating cell cycle progression, which was mediated by the Greatwall-endosulfine complex.


Assuntos
Sirolimo , Serina-Treonina Quinases TOR , Proteína Quinase CDC2 , Ciclo Celular , Transdução de Sinais , Sirolimo/farmacologia , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo
6.
J Proteome Res ; 18(3): 865-877, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30592415

RESUMO

Protein acetylation reportedly acts as a key regulator of autophagy. However, up to now, the relationship between acetylome and autophagy has remained unclear. Here stable isotope labeling of amino acids in cell culture and high-throughput quantitative mass spectrometry were used to perform an acetylome analysis of rapamycin-induced autophagy in vitro. Our data revealed that 2135 sites were quantified on 1081 proteins. During autophagy, 421 sites were significantly regulated on 296 proteins, with 80.8% of sites downregulated and 19.2% upregulated. Motif enrichment analysis revealed five main motifs. Most of the downregulated sites conformed to the classical functional motif of p300/CBP [G-AcK]. Furthermore, acetylation targeted proteins involved mainly in ribosomes, spliceosomes, and AcCoA-related metabolic process. In-depth analysis indicated that most of the acetylation sites were in the critical domain, were functional sites, or could change their enzymatic activity by acetylation, highlighting the importance of site-specific acetylation patterns. Subsequently, we demonstrated that K1549 of p300 was also a functional site that could regulate the autophagic process in vitro. In conclusion, our data reveal a deacetylation-preponderant profile with autophagy. The specificity of the related motifs and the identification of site-specific acetylation patterns will assist searches for potential targets or subsequent mechanism-focused studies to elucidate site-specific protein networks in autophagy.


Assuntos
Acetilação , Autofagia/efeitos dos fármacos , Lisina/metabolismo , Proteômica/métodos , Sirolimo/farmacologia , Sítios de Ligação , Humanos , Marcação por Isótopo/métodos , Processamento de Proteína Pós-Traducional , Espectrometria de Massas em Tandem/métodos
7.
Sci Rep ; 5: 15701, 2015 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-26549519

RESUMO

IL-6, a pleiotropic cytokine, has been investigated for its role in regulating autophagy. Yet, its mechanism of action remains unclear. Here, we show that IL-6 exerted anti-autophagic effects on U937 cells through the STAT3 signaling pathway in vitro. The addition of IL-6 to starved U937 cells significantly activated the phosphorylation level of STAT3 (p-STAT3) at Tyr705 and reduced the protein levels of microtubule-associated protein 1 light chain 3 of type II (LC3-II) and Beclin 1. By immunoblotting, we also observed a positive correlation between the p-STAT3 level and Bcl-2 level. Furthermore, treatment with a STAT3 inhibitor, LLL12, or overexpression of a mutant form, STAT3Y705F, reversed the inhibitory effect of IL-6 on autophagy. Knockdown of Beclin 1 or Atg14 by siRNA and over-expression of Beclin 1 indicated the involvement of class III PI3K complex in IL-6-mediated inhibition of autophagy. Taken together, these data indicate that IL-6 inhibits starvation-induced autophagy and that p-STAT3 mediates the signal transduction from IL-6 to downstream proteins including Bcl-2 and Beclin1.


Assuntos
Proteínas Reguladoras de Apoptose/genética , Interleucina-6/genética , Proteínas de Membrana/genética , Neoplasias/genética , Proteínas Proto-Oncogênicas c-bcl-2/genética , Fator de Transcrição STAT3/genética , Apoptose/genética , Proteínas Reguladoras de Apoptose/biossíntese , Autofagia , Proteína Beclina-1 , Linhagem Celular Tumoral , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Interleucina-6/metabolismo , Proteínas de Membrana/biossíntese , Neoplasias/metabolismo , Neoplasias/patologia , Fosfatidilinositol 3-Quinases , Proteínas Proto-Oncogênicas c-bcl-2/biossíntese , Fator de Transcrição STAT3/biossíntese , Transdução de Sinais , Inanição
8.
J Microbiol ; 53(9): 623-32, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26231372

RESUMO

The quorum quenching system of Agrobacterium tumefaciens is specifically activated upon entering the stationary phase. Evidence has shown that this system includes two key components: the IclR-type transcriptional factor AttJ (also named as BlcR) and the AHL-lactonase AttM (also named as BlcC). At exponential phase, AttJ binds to the promoter region of attM and thus suppresses the expression of attM. At stationary phase, however, the small molecule SSA directly binds to AttJ and relieves its inhibition of AttJ and thereby triggers the expression of attM. While the regulation of AttM has been extensively investigated, little is known about the regulation of AttJ. In this study, we demonstrated the D101 amino acid of AttJ is essential for the AttJ function. In vitro, the variant protein of AttJD101H appeared to be readily aggregated. In vivo, the D101H mutation in AttJ entirely abolished the inhibitory activity of AttJ and overexpressed attM in A. tumefaciens A6. In addition, D101H mutation led to an overexpression of attJ, indicating an auto-regulatory mechanism for the attJ regulation. Put together, these findings demonstrate that D101 is an important amino acid for the transcription activity of AttJ and the transcription of attJ is regulated by a negative feedback loop. These results expand previous biochemical characterization of AttJ and provide new mechanistic insights into the regulation of quorum quenching in A. tumefaciens.


Assuntos
Agrobacterium tumefaciens/genética , Agrobacterium tumefaciens/metabolismo , Proteínas de Bactérias/metabolismo , Regulação Bacteriana da Expressão Gênica , Percepção de Quorum/genética , Proteínas Repressoras/metabolismo , Agrobacterium tumefaciens/crescimento & desenvolvimento , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Hidrolases de Éster Carboxílico/genética , Retroalimentação Fisiológica , Mutação , Proteínas Repressoras/química , Proteínas Repressoras/genética , Transdução de Sinais
9.
PLoS One ; 9(5): e97174, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24819514

RESUMO

Paraspeckle protein 1 (PSPC1) was first identified as a structural protein of the subnuclear structure termed paraspeckle. However, the exact physiological functions of PSPC1 are still largely unknown. Previously, using a proteomic approach, we have shown that exposure to cisplatin can induce PSPC1 expression in HeLa cells, indicating the possible involvement for PSPC1 in the DNA damage response (DDR). In the current study, the role of PSPC1 in DDR was examined. First, it was found that cisplatin treatment could indeed induce the expression of PSPC1 protein. Abolishing PSPC1 expression by siRNA significantly inhibited cell growth, caused spontaneous cell death, and increased DNA damage. However, PSPC1 did not co-localize with γH2AX, 53BP1, or Rad51, indicating no direct involvement in DNA repair pathways mediated by these molecules. Interestingly, knockdown of PSPC1 disrupted the normal cell cycle distribution, with more cells entering the G2/M phase. Furthermore, while cisplatin induced G1/S arrest in HeLa cells, knockdown of PSPC1 caused cells to escape the G1/S checkpoint and enter mitosis, and resulted in more cell death. Taken together, these observations indicate a new role for PSPC1 in maintaining genome integrity during the DDR, particularly in the G1/S checkpoint.


Assuntos
Antineoplásicos/farmacologia , Cisplatino/farmacologia , Dano ao DNA , Pontos de Checagem da Fase G1 do Ciclo Celular/efeitos dos fármacos , Fase G2/efeitos dos fármacos , Proteínas Nucleares/metabolismo , Proteínas de Ligação a RNA/metabolismo , Pontos de Checagem da Fase S do Ciclo Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Células HeLa , Histonas/metabolismo , Humanos , Proteínas Nucleares/deficiência , Proteínas Nucleares/genética , Proteínas de Ligação a RNA/genética
10.
PLoS One ; 9(1): e84974, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24454774

RESUMO

The wide application of multi-walled carbon nanotubes (MWCNT) has raised serious concerns about their safety on human health and the environment. However, the potential harmful effects of MWCNT remain unclear and contradictory. To clarify the potentially toxic effects of MWCNT and to elucidate the associated underlying mechanisms, the effects of MWCNT on human lung adenocarcinoma A549 cells were examined at both the cellular and the protein level. Cytotoxicity and genotoxicity were examined, followed by a proteomic analysis (2-DE coupled with LC-MS/MS) of the cellular response to MWCNT. Our results demonstrate that MWCNT induces cytotoxicity in A549 cells only at relatively high concentrations and longer exposure time. Within a relatively low dosage range (30 µg/ml) and short time period (24 h), MWCNT treatment does not induce significant cytotoxicity, cell cycle changes, apoptosis, or DNA damage. However, at these low doses and times, MWCNT treatment causes significant changes in protein expression. A total of 106 proteins show altered expression at various time points and dosages, and of these, 52 proteins were further identified by MS. Identified proteins are involved in several cellular processes including proliferation, stress, and cellular skeleton organization. In particular, MWCNT treatment causes increases in actin expression. This increase has the potential to contribute to increased migration capacity and may be mediated by reactive oxygen species (ROS).


Assuntos
Nanotubos de Carbono/toxicidade , Proteômica , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Citocinas/biossíntese , Relação Dose-Resposta a Droga , Humanos , Espécies Reativas de Oxigênio/metabolismo , Células Th1/efeitos dos fármacos , Células Th1/metabolismo , Células Th2/efeitos dos fármacos , Células Th2/metabolismo , Fatores de Tempo
11.
J Bacteriol ; 196(7): 1403-11, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24464459

RESUMO

Quorum sensing (QS) is a widespread mechanism of bacterial communication in which individual cells produce and respond to small chemical signals. In Agrobacterium tumefaciens, an acylhomoserine lactone-dependent QS mechanism is known to regulate the replication and conjugation of the tumor-inducing (Ti) plasmid. Most of the QS regulatory proteins are encoded within the Ti plasmid. Among them, TraI is the LuxI-type enzyme synthesizing the QS signal N-3-oxooctanoyl-L-homoserine lactone (3OC8HSL), TraR is the LuxR-type transcriptional factor that recognizes 3OC8HSL, and TraM is an antiactivator that antagonizes TraR. Recently, we identified a TraM homolog encoded by the traM2 gene in the chromosomal background of A. tumefaciens A6. In this study, we further identified additional homologs (TraI2 and TraR2) of TraI and TraR in this strain. We showed that similar to TraI, TraI2 could predominantly synthesize the QS signal 3OC8HSL. We also showed that TraR2 could recognize 3OC8HSL and activate the tra box-containing promoters as efficiently as TraR. Further analysis showed that traM2, traI2, and traR2 are physically linked on a mobile genetic element that is not related to the Ti plasmid. These findings indicate that A. tumefaciens A6 carries a second QS system that may play a redundant role in the regulation of the replication and conjugation of the Ti plasmid.


Assuntos
Agrobacterium tumefaciens/fisiologia , Proteínas de Bactérias/metabolismo , Percepção de Quorum , 4-Butirolactona/análogos & derivados , 4-Butirolactona/metabolismo , Agrobacterium tumefaciens/genética , Proteínas de Bactérias/genética , Regulação Bacteriana da Expressão Gênica
12.
Mutat Res ; 753(1): 54-64, 2013 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-23416234

RESUMO

Nanomaterial-biosystem interaction is emerging as a major concern hindering wide adoption of nanomaterials. Using quantum dots (Qdots) of different sizes (Qdot-440nm and Qdot-680nm) as a model system, we studied the effects of polyethylene glycol (PEG) thin-layer surface modification in attenuating Qdot-related cytotoxicity, genotoxicity perturbation and oxidative stress in a cellular system. We found that uncoated Qdots (U-Qdots) made of core/shell CdSe/ZnS could indeed induce cytotoxic effects, including the inhibition of cell growth. Also, both the neutral comet assay and γH2AX foci formation showed that U-Qdots caused significant DNA damage in a time- and dose-dependent manner. In contrast, results from cytotoxicity analysis and γH2AX generation indicate minimal impact on cells after exposure to PEG-coated Qdots. This lack of observed toxic effects from PEG-coated Qdots may be due to the fact that PEG-coating can inhibit ROS generation induced by U-Qdots. Based on these observations, we conclude that the genotoxicity of Qdots could be significantly decreased following proper surface modification, such as PEG encapsulation. In addition, PEG encapsulation may also serve as a general method to attenuate nanotoxicity for other nanoparticles.


Assuntos
Compostos de Cádmio/toxicidade , Dano ao DNA/efeitos dos fármacos , Células Epiteliais/efeitos dos fármacos , Polietilenoglicóis/farmacologia , Pontos Quânticos , Compostos de Selênio/toxicidade , Sulfetos/toxicidade , Compostos de Zinco/toxicidade , Acetilcisteína/farmacologia , Materiais Biocompatíveis , Biomarcadores/análise , Células Cultivadas/química , Células Cultivadas/efeitos dos fármacos , Células Cultivadas/ultraestrutura , Ensaio Cometa , Quebras de DNA de Cadeia Dupla/efeitos dos fármacos , Composição de Medicamentos , Células Epiteliais/química , Células Epiteliais/ultraestrutura , Sequestradores de Radicais Livres/farmacologia , Histonas/análise , Humanos , Interações Hidrofóbicas e Hidrofílicas , Teste de Materiais , Tamanho da Partícula , Polietilenoglicóis/administração & dosagem , Espécies Reativas de Oxigênio/análise , Pele/citologia , Propriedades de Superfície/efeitos dos fármacos
13.
Toxicol Appl Pharmacol ; 266(1): 9-18, 2013 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-23147571

RESUMO

Previous studies have reported that a Gamitrinib variant containing triphenylphosphonium (G-TPP) binds to mitochondrial Hsp90 and rapidly inhibits its activity, thus inducing the apoptotic pathway in the cells. Accordingly, G-TPP shows a potential as a promising drug for the treatment of cancer. A cell can die from different types of cell death such as apoptosis, necrosis, necroptosis, and autophagic cell death. In this study, we further investigated the mechanisms and modes of cell death in the G-TPP-treated Hep3B and U937 cell lines. We discovered that G-TPP kills the U937 cells through the apoptotic pathway and the overexpression of Bcl-2 significantly inhibits U937 cell death to G-TPP. We further discovered that G-TPP kills the Hep3B cells by activating necroptosis in combination with the partial activation of caspase-dependent apoptosis. Importantly, G-TPP overcomes the apoptosis resistance conferred by Bcl-2 in Hep3B cells via necroptosis. We also observed that G-TPP induces compensatory autophagy in the Hep3B cell line. We further found that whereas there is a Bcl-2-Beclin 1 interaction in response to G-TPP, silencing the beclin 1 gene failed to block LC3-II accumulation in the Hep3B cells, indicating that G-TPP triggers Beclin 1-independent protective autophagy in Hep3B cells. Taken together, these data reveal that G-TPP induces cell death through a combination of death pathways, including necroptosis and apoptosis, and overcomes the apoptosis resistance conferred by Bcl-2 in Hep3B cells via necroptosis. These findings are important for the therapeutic exploitation of necroptosis as an alternative cell death program to bypass the resistance to apoptosis.


Assuntos
Apoptose/fisiologia , Guanidinas/administração & dosagem , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Proteínas de Choque Térmico HSP90/metabolismo , Lactamas Macrocíclicas/administração & dosagem , Mitocôndrias/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/biossíntese , Apoptose/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Relação Dose-Resposta a Droga , Sistemas de Liberação de Medicamentos/métodos , Guanidinas/química , Humanos , Lactamas Macrocíclicas/química , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/patologia , Necrose , Células U937
14.
Neuro Oncol ; 14(11): 1332-45, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23074197

RESUMO

Although crystallins are major structural proteins in the lens, α-crystallins perform non-lens functions, and αB-crystallin has been shown to act as an anti-apoptotic mediator in various cells. The present study was undertaken to examine whether αB-crystallin expressed in human malignant glioma cells exerts anti-apoptotic activity. In addition, we sought to elucidate the mechanism underlying any observed anti-apoptotic function of αB-crystallin in these cells. Three glioma cell lines, U373MG, U118MG, and T98G, were used. We observed that only the U373MG cell line expresses αB-crystallin, whereas the other 2 glioma cell lines, U118MG and T98G, demonstrated no endogenous expression of αB-crystallin. We next observed that the silencing of αB-crystallin sensitized U373MG cells to suberoylanilide hydroxamic acid (SAHA)-induced apoptosis and that αB-crystallin associates with caspase-3 and XIAP. Because XIAP is the most potent suppressor of mammalian apoptosis through the direct binding with caspases, we assessed whether XIAP also plays an anti-apoptotic role in SAHA-induced apoptosis in αB-crystallin-expressing U373MG cells. Of note, the silencing of XIAP did not alter the amount of cell death induced by SAHA, indicating that XIAP does not exert an anti-apoptotic activity in U373MG cells. We then determined whether the ectopic expression of αB-crystallin in glioma cells caused a loss of the anti-apoptotic activity of XIAP. Accordingly, we established 2 αB-crystallin over-expressing glioma cell lines, U118MG and T98G, and found that the silencing of XIAP did not sensitize these cells to SAHA-induced apoptosis. These findings suggest that αB-crystallin expressed in glioma cells overrides the anti-apoptotic activity exerted by XIAP.


Assuntos
Apoptose/fisiologia , Glioma/metabolismo , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/metabolismo , Cadeia B de alfa-Cristalina/metabolismo , Western Blotting , Linhagem Celular Tumoral , Citometria de Fluxo , Humanos , Imuno-Histoquímica , Imunoprecipitação , Microscopia Confocal , RNA Interferente Pequeno , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transfecção
15.
Mutat Res ; 731(1-2): 75-84, 2012 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-22138005

RESUMO

Previously, we employed a proteomics-based 2-D gel electrophoresis assay to show that exposure to 10µM benzo(a)pyrene (BaP) during a 24 h frame can lead to changes in nuclear protein expression and alternative splicing. To further expand our knowledge about the DNA damage response (DDR) induced by BaP, we investigated the nuclear protein expression profiles in HeLa cells treated with different concentrations of BaP (0.1, 1, and 10µM) using this proteomics-based 2-D gel electrophoresis assay. We found 125 differentially expressed proteins in BaP-treated cells compared to control cells. Among them, 79 (63.2%) were down-regulated, 46 (36.8%) were up-regulated; 8 showed changes in the 1µM and 10µM BaP-treated groups, 2 in the 0.1µM and 10µM BaP-treated groups, 4 in the 0.1µM and 1µM BaP-treated groups, and only one showed changes in all three groups. Fifty protein spots were chosen for liquid chromatography-tandem mass spectrometry (LC-MS/MS) identification, and of these, 39 were identified, including subunits of the 26S proteasome and Annexin A1. The functions of some identified proteins were further examined and the results showed that they might be involved in BaP-induced DDR. Taken together, these data indicate that proteomics is a valuable approach in the study of environmental chemical-host interactions, and the identified proteins could provide new leads for better understanding BaP-induced mutagenesis and carcinogenesis.


Assuntos
Benzo(a)pireno/toxicidade , Dano ao DNA/efeitos dos fármacos , Células HeLa/efeitos dos fármacos , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteoma/efeitos dos fármacos , Anexina A1/análise , Anexina A1/genética , Dissacarídeos , Glucuronatos , Humanos , NF-kappa B/genética , NF-kappa B/metabolismo , Complexo de Endopeptidases do Proteassoma/genética , Proteoma/genética
16.
Toxicol In Vitro ; 25(1): 91-9, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20888899

RESUMO

H2AX is phosphorylated (γH2AX) by members of the phosphatidylinositol 3-kinase (PI3K) family, including ataxia telangiectasia-mutated (ATM), ATM- and Rad3-related (ATR) and DNA-PK in response to DNA damage. While it has been reported that benzo[a]pyrene (BaP) cannot induce γH2AX alone in several cell lines, we have shown that BaP alone could induce γH2AX in human amnion FL cells. Thus, we further examined the ability of BaP to induce γH2AX in different cell systems. It was shown that BaP-induced γH2AX in HeLa cells in a time- and dose-dependent manner. BaP also induced γH2AX in ATM(-/-) mouse fibroblasts, DNA-PKcs(-/-) mouse fibroblasts, and a genetically modified human osteosarcoma U2OS cell line. PI3K inhibitors caffeine and wortmannin were then used in an effort to identify the kinase(s) responsible for BaP-induced γH2AX. Unexpectedly, in BaP-treated HeLa cells, caffeine pretreatment did not inhibit but rather increased γH2AX level. On the other hand, caffeine or wortmannin can inhibit BaP-induced γH2AX in either U2OS, DNA-PKcs(-/-) or ATM(-/-) cells. Taken together, these data suggest that BaP alone can induce H2AX phosphorylation in certain cell systems, and that members of the PI3K family, including ATM, ATR, and DNA-PK can participate in the phosphorylation of H2AX in the various cell types.


Assuntos
Benzo(a)pireno/farmacologia , Proteínas de Ciclo Celular/metabolismo , Proteína Quinase Ativada por DNA/metabolismo , Proteínas de Ligação a DNA/metabolismo , Histonas/metabolismo , Mutagênicos/farmacologia , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Androstadienos/farmacologia , Animais , Proteínas Mutadas de Ataxia Telangiectasia , Cafeína/farmacologia , Ciclo Celular , Proteínas de Ciclo Celular/antagonistas & inibidores , Proteínas de Ciclo Celular/genética , Linhagem Celular , Proteína Quinase Ativada por DNA/antagonistas & inibidores , Proteína Quinase Ativada por DNA/genética , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/genética , Humanos , Camundongos , Concentração Osmolar , Fosforilação/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/genética , Fatores de Tempo , Proteínas Supressoras de Tumor/antagonistas & inibidores , Proteínas Supressoras de Tumor/genética , Wortmanina
17.
Mutat Res ; 691(1-2): 1-8, 2010 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-20540955

RESUMO

Cisplatin has been widely accepted as one of the most efficient anticancer drugs for decades. However, the mechanisms for the cytotoxic effects of cisplatin are still not fully understood. Cisplatin primarily targets DNA, resulting in the formation of DNA double strand breaks and eventually causing cell death. In this study, we applied two-dimensional electrophoresis coupled with LC-MS/MS to analyze the nuclear proteome of HeLa cells treated with cisplatin, in an effort to uncover new mechanistic clues regarding the cellular response to cisplatin. A total of 19 proteins were successfully identified, and these proteins are involved in a variety of basal metabolic and biological processes in cells, including biosynthesis, cell cycle, glycolysis and apoptosis. Six were related to the regulation of mRNA splicing, and we therefore asked whether the Fas gene might undergo alternative splicing following cisplatin treatment. This proved to be the case, as the splicing forms of Fas were modified in cisplatin-treated HeLa cells. This work provides novel information, from the perspective of the nuclear response, for understanding the cytotoxicity caused by cisplatin-induced DNA damage.


Assuntos
Antineoplásicos/farmacologia , Cisplatino/farmacologia , Dano ao DNA , Proteínas Nucleares/efeitos dos fármacos , Proteoma/efeitos dos fármacos , Processamento Alternativo/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica , Células HeLa , Humanos , Proteoma/metabolismo , Receptor fas/genética
18.
Mutat Res ; 686(1-2): 47-56, 2010 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-20097212

RESUMO

Benzo[a]pyrene (BaP) is a potent pro-carcinogen generated from the combustion of fossil fuel and cigarette smoke. Previously, using a proteomic approach, we have shown that BaP can induce changes in the expression of many cellular proteins, including transcription regulators. In the present study, using a similar approach, we examined the nuclear protein response to BaP in HeLa cells and found that BaP treatment caused expression changes in many nuclear proteins. Twenty-four of these proteins were successfully identified, several of which are involved in the alternative splicing of mRNA, DNA replication, recombination, and repair. The changed expression levels were further confirmed by immunoblot analysis using specific antibodies for two proteins, Lamin A and mitotic checkpoint protein Bub3. The nuclear localization of these two proteins was also confirmed by confocal microscopy. To determine whether alternative splicing was activated following BaP treatment, we examined Fas and CD44, two genes previously shown to be targets of alternative splicing in respond to DNA damage. While no significant activation of alternative splicing was observed for Fas, CD44 splicing variants were found after BaP treatment. Together, these data show that DNA damage induces dramatic changes in nuclear protein expression, and that alternative splicing might be involved in the cellular response to DNA damage.


Assuntos
Processamento Alternativo/efeitos dos fármacos , Benzo(a)pireno/farmacologia , Mutagênicos/farmacologia , Proteínas Nucleares/metabolismo , Proteínas de Ciclo Celular/metabolismo , Fracionamento Celular , Dano ao DNA , Cromatografia Gasosa-Espectrometria de Massas , Células HeLa , Humanos , Receptores de Hialuronatos/genética , Lamina Tipo A/metabolismo , Proteínas de Ligação a Poli-ADP-Ribose , Receptor fas/genética
19.
Biotechnol Lett ; 30(10): 1741-6, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18661109

RESUMO

Nostoc sphaeroides Kützing was cultivated in paddlewheel-driven raceway ponds and the growth kinetics of 1-2 mm and 3-4 mm colonies of N. sphaeroides was studied. The biomass productivities in 2.5 m(2) raceway ponds inoculated with 1-2 mm and 3-4 mm colonies were 5.2 and 0.25 g dry wt m(-2) d(-1), respectively. Furthermore, differently sized colonies showed different relative water content, total soluble carbohydrates, chlorophyll a content and density of filaments. This is the first report on mass culture of N. sphaeroides under outdoor conditions.


Assuntos
Nostoc/crescimento & desenvolvimento , Biomassa , Cinética
20.
Artigo em Inglês | MEDLINE | ID: mdl-16525943

RESUMO

Polymorphisms of ACE insertion/deletion (I/D) and angiotensin II type 1 receptor (AT1R) 1166A-C have been associated with many diseases, and distributions of their genotypes vary in different races and populations. The aim of this study was to investigate distributions of angiotensin-converting enzyme (ACE) and AT1R genotypes in Han and She populations in ZheJiang province. We determined ACE and AT1R genotypes in 189 Han and 163 She individuals. DNA was extracted from peripheral blood samples. Analyses of ACE and AT1R genotypes were performed by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). The frequencies of ACE genotypes and alleles among the Han sample (41.3%II, 41.3%ID, 17.5%DD; 61.9%I allele, 38.1%D allele) were similar to those among She individuals (39.9%II, 39.3%ID, 20.9%DD; 59.5%I allele, 40.5%D allele), with p=0.660; p=0.421. However, significant differences in the distributions of ACE polymorphism between men and women among She population were observed, with p=0.042, p=0.014. AT1R genotype and allele frequencies in the Han population were (88.4%AA, 11.1%AC, 0.5%CC) and (93.9%A allele, 6.1%C) allele respectively. In the She population they were (78.0%AA, 21.3%AC, 0.6%CC) and (89.0%A allele, 11.0%C allele). The significant differences were found between Han and She populations with p=0.031, p=0.018, and within subgroups of women, with p=0.010, p=0.021. There were no significant differences within subgroups of men (p=0.476, p=0.261). The genotype distributions or allele frequencies of ACE and AT1R were significantly different between the samples of the She and Han populations.


Assuntos
Etnicidade/genética , Peptidil Dipeptidase A/genética , Polimorfismo Genético , Receptor Tipo 1 de Angiotensina/genética , Povo Asiático/genética , China , Feminino , Frequência do Gene , Genótipo , Humanos , Íntrons , Masculino , Caracteres Sexuais
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