RESUMEN
Waste activated sludge (WAS) and meat processing waste (MPW) were acted as co-substrates in anaerobic co-digestion (AcD), and biochemical methane potential (BMP) test was carried out to investigate the methane production performances. Microbial community structure and metabolic pathways analyses were conducted by 16S rRNA high-throughput sequencing and functional prediction analysis. BMP test results indicated that AcD of 70% WAS+30% MPW and 50% WAS+50% MPW (VS/VS) could significantly improve methane yield to 371.05 mL/g VS and 599.61 mL/g VS, respectively, compared with WAS acting as sole substrate (191.87 mL/g VS). The results of microbial community analysis showed that Syntrophomonas and Petrimonas became the dominant bacteria genera, and Methanomassiliicoccus and Methanobacterium became the dominant archaea genera after MPW addition. 16S functional prediction analysis results indicated that genes expression of key enzymes involved in syntrophic acetate oxidation (SAO), hydrogenotrophic and methylotrophic methanogenesis were up-regulated, and acetoclastic methanogenesis was inhibited after MPW addition. Based on these analyses, it could be inferred that SAO combined with hydrogenotrophic and methylotrophic methanogenesis was the dominant pathway for organics degradation and methane production during AcD. These findings provided systematic insights into the microbial community changes and metabolic pathways during AcD of WAS and MPW.
Asunto(s)
Metano , Aguas del Alcantarillado , Aguas del Alcantarillado/microbiología , Anaerobiosis , Metano/metabolismo , Redes y Vías Metabólicas , ARN Ribosómico 16S , Bacterias/metabolismo , Bacterias/genética , Carne , Archaea/metabolismo , Archaea/genéticaRESUMEN
PURPOSE: We investigated the role of farnesoid X receptor (FXR), a ligand-dependent transcription factor, in renal ischaemia-reperfusion (I/R) injury. MATERIALS AND METHODS: We performed unilateral renal I/R model in FXR knockout (Fxr-/- ) and wild-type (WT) mice in vivo and a hypoxia-reoxygenation (H/R) model in vitro. The pathways by which FXR induces apoptosis were detected using a proteome profiler array. The effects of FXR on apoptosis were evaluated using immunoblotting, TUNEL assays and flow cytometry. RESULTS: Compared with WT mice, Fxr-/- mice showed improved renal function and reduced tubular injury scores and apoptosis. Consistent with the in vivo results, the silencing of FXR decreased the number of apoptotic HK-2 cells after H/R, while FXR overexpression aggravated apoptosis. Notably, bone marrow transplantation (BMT) and immunohistochemistry experiments revealed the involvement of FXR in the tubular epithelium rather than in inflammatory cells. Furthermore, in vivo and in vitro studies demonstrated that FXR deficiency increased phosphorylated Bcl-2 agonist of cell death (p-Bad) expression levels and the ratio of Bcl-2/Bcl-xL to Bax expression in the kidney. Treatment with wortmannin, which reduced p-Bad expression, inhibited the effects of FXR deficiency and eliminated the tolerance of Fxr-/- mouse kidneys to I/R injury. CONCLUSIONS: These results established the pivotal importance of FXR inactivation in tubular epithelial cells after I/R injury. FXR may promote the apoptosis of renal tubular epithelial cells by inhibiting PI3k/Akt-mediated Bad phosphorylation to cause renal I/R damage.
Asunto(s)
Apoptosis , Receptores Citoplasmáticos y Nucleares/metabolismo , Daño por Reperfusión/patología , Animales , Apoptosis/efectos de los fármacos , Línea Celular , Modelos Animales de Enfermedad , Regulación hacia Abajo/efectos de los fármacos , Células Epiteliales/citología , Células Epiteliales/metabolismo , Riñón/metabolismo , Riñón/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Interferencia de ARN , ARN Interferente Pequeño/metabolismo , Receptores Citoplasmáticos y Nucleares/antagonistas & inhibidores , Receptores Citoplasmáticos y Nucleares/genética , Daño por Reperfusión/metabolismo , Transducción de Señal/efectos de los fármacos , Wortmanina/farmacología , Proteína X Asociada a bcl-2/metabolismo , Proteína bcl-X/metabolismoRESUMEN
The diverse repertoire of T cell receptors (TCR) and immunoglobulins is generated through the somatic rearrangement of respective V, D and J gene segments, termed V(D)J recombination, during early T or B cell development. However, epigenetic regulation of V(D)J recombination is still not fully understood. Here we show that the deficiency of Setd2, a histone methyltransferase that catalyzes lysine 36 trimethylation on histone 3 (H3K36me3) in mice, causes a severe developmental block of thymocytes at the CD4-CD8- DN3 stage. While H3K36me3 is normally enriched at the TCRß locus, Setd2 deficiency reduces TCRß H3K36me3 and suppresses TCRß V(D)J rearrangement by impairing RAG1 binding to TCRß loci and the DNA double-strand break repair. Similarly, Setd2 ablation also impairs immunoglobulin V(D)J rearrangement to induce B cell development block at the pro-B stage. Lastly, SETD2 is frequently mutated in patients with primary immunodeficiency. Our study thus demonstrates that Setd2 is required for optimal V(D)J recombination and normal lymphocyte development.
Asunto(s)
N-Metiltransferasa de Histona-Lisina/metabolismo , Recombinación V(D)J , Secuencias de Aminoácidos , Animales , Linfocitos B/citología , Linfocitos B/enzimología , Diferenciación Celular , Preescolar , Epigénesis Genética , N-Metiltransferasa de Histona-Lisina/genética , Histonas/química , Histonas/metabolismo , Humanos , Lactante , Lisina/genética , Lisina/metabolismo , Masculino , Metilación , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Mutación , Enfermedades de Inmunodeficiencia Primaria/enzimología , Enfermedades de Inmunodeficiencia Primaria/genética , Receptores de Antígenos de Linfocitos T alfa-beta/genética , Receptores de Antígenos de Linfocitos T alfa-beta/metabolismo , Linfocitos T/citologíaRESUMEN
Hydroquinone (HQ), one of the major metabolic products of benzene, is a carcinogen, which induces apoptosis and inhibit proliferation in lymphoma cells. microRNA-7-5p (miR-7-5p), a tumor suppressor, participates in various biological processes including cell proliferation and apoptosis regulation by repressing expression of specific oncogenic target genes. To explore whether miR-7-5p is involved in HQ-induced cell proliferation and apoptosis, we assessed the effect of miR-7-5p overexpression on induction of apoptosis analyzed by FACSCalibur flow cytometer in transfection of TK6 cells with miR-7-5p mimic (TK6- miR-7-5p). We observed an increased apoptosis by 25.43% and decreased proliferation by 28.30% in TK6-miR-7-5p cells compared to those negative control cells (TK6-shNC) in response to HQ treatment. Furthermore, HQ might active the apoptotic pathway via partly downregulation the expression of BRCA1 and PARP-1, followed by p53 activation, in TK6-miR-7-5p cells. In contrast, attenuated p53 and BRCA1 expression was observed in shPARP-1â¯cells than in NC cells after HQ treatment. Therefore, we conclude that HQ may activate apoptotic signals via inhibiting the tumor suppressive effects of miR-7-5p, which may be mediated partly by upregulating the expression of PARP-1 and BRCA1 in control cells. The increase of miR-7-5p expression further intensified downregulation of PARP-1 and BRCA1 in TK6-miR-7-5p cells, resulting in an increase of apoptosis and proliferation inhibited.
Asunto(s)
Apoptosis/efectos de los fármacos , Proteína BRCA1/metabolismo , Proliferación Celular/efectos de los fármacos , Reparación del ADN/efectos de los fármacos , Hidroquinonas/farmacología , MicroARNs/metabolismo , Poli(ADP-Ribosa) Polimerasa-1/metabolismo , Regiones no Traducidas 3' , Antagomirs/metabolismo , Proteína BRCA1/genética , Caspasa 3/metabolismo , Línea Celular Tumoral , Regulación hacia Abajo/efectos de los fármacos , Humanos , MicroARNs/antagonistas & inhibidores , MicroARNs/genética , Poli(ADP-Ribosa) Polimerasa-1/antagonistas & inhibidores , Poli(ADP-Ribosa) Polimerasa-1/genética , Interferencia de ARN , ARN Interferente Pequeño/metabolismo , Proteína p53 Supresora de Tumor/metabolismoRESUMEN
B cell leukemia/lymphoma-2 (Bcl-2) suppresses apoptosis by binding the BH3 domain of proapoptotic factors and thereby regulating mitochondrial membrane potential (MMP). This study aimed to investigate the role of Bcl-2 in controlling the mitochondrial pathway of apoptosis during hydroquinone (HQ)-induced TK6 cytotoxicity. In this study, HQ, one metabolite of benzene, decreased the MMP in a concentration-dependent manner and induced the generation of reactive oxygen species (ROS), the activation of the DNA damage marker γ-H2AX, and production of the DNA damage-responsive enzyme poly(ADP-ribose)polymerase-1 (PARP-1). Exposure of TK6 cells to HQ leads to an increase in Bcl-2 and co-localization with PARP-1 in the cytoplasm. Inhibition of Bcl-2 using the BH3 mimetic, ABT-737, suppressed the PARP-1 nuclear to cytoplasm translocation and sensitized TK6 cells to HQ-induced apoptosis through depolarization of the MMP. Western blot analysis indicated that ABT-737 combined with HQ increased the levels of cleaved PARP and γ-H2AX, but significantly decreased the level of P53. Thus, ABT-737 can influence PARP-1 translocation and induce apoptosis via mitochondria-mediated apoptotic pathway, independently of P53. In addition, we found that knockdown of PARP-1 attenuated the HQ-induced production of cleaved PARP and P53. These results identify Bcl-2 as a protective mediator of HQ-induced apoptosis and show that upregulation of Bcl-2 helps to localize PARP-1 to the cytoplasm and stabilize MMP. Environ. Mol. Mutagen. 59:49-59, 2018. © 2017 Wiley Periodicals, Inc.
Asunto(s)
Apoptosis/fisiología , Hidroquinonas/efectos adversos , Potencial de la Membrana Mitocondrial/fisiología , Mitocondrias/metabolismo , Poli(ADP-Ribosa) Polimerasa-1/metabolismo , Transporte de Proteínas/fisiología , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Citoplasma/efectos de los fármacos , Citoplasma/metabolismo , Humanos , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Mitocondrias/efectos de los fármacos , Transporte de Proteínas/efectos de los fármacos , Proteína p53 Supresora de Tumor/metabolismoRESUMEN
Renal ischemia-reperfusion is a main cause of acute kidney injury (AKI), which is associated with high mortality. Here we show that extracellular vesicles (EVs) secreted from hiPSC-MSCs play a critical role in protection against renal I/R injury. hiPSC-MSCs-EVs can fuse with renal cells and deliver SP1 into target cells, subsequently active SK1 expression and increase S1P formation. Chromatin immunoprecipitation (ChIP) analyses and luciferase assay were used to confirm SP1 binds directly to the SK1 promoter region and promote promoter activity. Moreover, SP1 inhibition (MIT) or SK1 inhibition (SKI-II) completely abolished the renal protective effect of hiPSC-MSCs-EVs in rat I/R injury mode. However, pre-treatment of necroptosis inhibitor Nec-1 showed no difference with the administration of hiPSC-MSCs-EVs only. We then generated an SP1 knockout hiPSC-MSC cell line by CRISPR/Cas9 system and found that SP1 knockout failed to show the protective effect of hiPSC-MSCs-EVs unless restoring the level of SP1 by Ad-SP1 in vitro and in vivo. In conclusion, this study describes an anti-necroptosis effect of hiPSC-MSCs-EVs against renal I/R injury via delivering SP1 into target renal cells and intracellular activating the expression of SK1 and the generation of S1P. These findings suggest a novel mechanism for renal protection against I/R injury, and indicate a potential therapeutic approach for a variety of renal diseases and renal transplantation.
Asunto(s)
Lesión Renal Aguda/prevención & control , Vesículas Extracelulares/química , Células Madre Mesenquimatosas/metabolismo , Necrosis/prevención & control , Fosfotransferasas (Aceptor de Grupo Alcohol)/genética , Daño por Reperfusión/prevención & control , Factor de Transcripción Sp1/genética , Lesión Renal Aguda/genética , Lesión Renal Aguda/metabolismo , Lesión Renal Aguda/patología , Animales , Apoptosis/genética , Diferenciación Celular , Línea Celular Transformada , Células Epiteliales/citología , Células Epiteliales/metabolismo , Regulación de la Expresión Génica , Humanos , Células Madre Pluripotentes Inducidas/citología , Células Madre Pluripotentes Inducidas/metabolismo , Riñón/metabolismo , Riñón/patología , Lisofosfolípidos/metabolismo , Masculino , Células Madre Mesenquimatosas/citología , Necrosis/genética , Necrosis/metabolismo , Necrosis/patología , Fosfotransferasas (Aceptor de Grupo Alcohol)/metabolismo , Ratas , Ratas Sprague-Dawley , Daño por Reperfusión/genética , Daño por Reperfusión/metabolismo , Daño por Reperfusión/patología , Transducción de Señal , Factor de Transcripción Sp1/deficiencia , Esfingosina/análogos & derivados , Esfingosina/metabolismoRESUMEN
Previous studies have shown that long noncoding RNAs (lncRNAs) were related to human carcinogenesis and might be designated as diagnosis and prognosis biomarkers. Hydroquinone (HQ), as one of the metabolites of benzene, was closely relevant to occupational benzene poisoning and occupational leukemia. Using high-throughput sequencing technology, we investigated differences in lncRNA and mRNA expression profiles between experimental group (HQ 20 µmol/L) and control group (PBS). Compared to control group, a total of 65 lncRNAs and 186 mRNAs were previously identified to be aberrantly expressed more than two fold change in experimental group. To validate the sequencing results, we selected 10 lncRNAs and 10 mRNAs for quantitative real-time PCR (qRT-PCR). Through GO annotation and KEGG pathway analysis, we obtained 3 mainly signaling pathways, including P53 signaling pathway, which plays an important role in tumorigenesis and progression. After that, 25 lncRNAs and 32 mRNAs formed the lncRNA-mRNA co-expression network were implemented to play biological functions of the dysregulated lncRNAs transcripts by regulating gene expression. The lncRNAs target genes prediction provided a new idea for the study of lncRNAs. Finally, we have another important discovery, which is screened out 11 new lncRNAs without annotated. All these results uncovered that lncRNA and mRNA expression profiles in TK6 cells exposed to low dose HQ were different from control group, helping to further study the toxicity mechanisms of HQ and providing a new direction for the therapy of leukemia.
RESUMEN
BACKGROUND/AIMS: This study aimed to evaluate the effects of exosomes produced by human-induced pluripotent stem cell-derived mesenchymal stromal cells (hiPSC-MSCs-Exo) on hepatic ischemia-reperfusion (I/R) injury, as well as the underlying mechanisms. METHODS: Exosomes derived from hiPSC-MSCs were isolated and characterized both biochemically and biophysically. hiPSC-MSCs-Exo were injected systemically into a murine ischemia/reperfusion injury model via the inferior vena cava, and then the therapeutic effects were evaluated. The serum levels of transaminases (aspartate aminotransferase (AST) and alanine aminotransferase (ALT), as well as histological changes were examined. Primary hepatocytes and human hepatocyte cell line HL7702 were used to test whether exosomes could induce hepatocytes proliferation in vitro. In addition, the expression levels of proliferation markers (proliferation cell nuclear antigen, PCNA; Phosphohistone-H3, PHH3) were measured by immunohistochemistry and Western blot. Moreover, SK inhibitor (SKI-II) and S1P1 receptor antagonist (VPC23019) were used to investigate the role of sphingosine kinase and sphingosine-1-phosphate-dependent pathway in the effects of hiPSC-MSCs-Exo on hepatocytes. RESULTS: hiPSCs were efficiently induced into hiPSC-MSCs that had typical MSC characteristics. hiPSC-MSCs-Exo had diameters ranging from 100 to 200 nm and expressed exosome markers (Alix, CD63 and CD81). After hiPSC-MSCs-Exo administration, hepatocyte necrosis and sinusoidal congestion were markedly suppressed in the ischemia/reperfusion injury model, with lower histopathological scores. The levels of hepatocyte injury markers AST and ALT were significantly lower in the treatment group compared to control, and the expression levels of proliferation markers (PCNA and PHH3) were greatly induced after hiPSC-MSCs-Exo administration. Moreover, hiPSC-MSCs-Exo also induced primary hepatocytes and HL7702 cells proliferation in vitro in a dose-dependent manner. We found that hiPSC-MSCs-Exo could directly fuse with target hepatocytes or HL7702 cells and increase the activity of sphingosine kinase and synthesis of sphingosine-1-phosphate (S1P). Furthermore, the inhibition of SK1 or S1P1 receptor completely abolished the protective and proliferative effects of hiPSC-MSCs-Exo on hepatocytes, both in vitro and in vivo. CONCLUSIONS: Our results demonstrated that hiPSC-MSCs-Exo could alleviate hepatic I/R injury via activating sphingosine kinase and sphingosine-1-phosphate pathway in hepatocytes and promote cell proliferation. These findings represent a novel mechanism that potentially contributes to liver regeneration and have important implications for new therapeutic approaches to acute liver disease.
Asunto(s)
Exosomas/metabolismo , Células Madre Pluripotentes Inducidas/citología , Hígado/metabolismo , Lisofosfolípidos/metabolismo , Células Madre Mesenquimatosas/citología , Fosfotransferasas (Aceptor de Grupo Alcohol)/metabolismo , Daño por Reperfusión/terapia , Esfingosina/análogos & derivados , Animales , Línea Celular , Proliferación Celular , Células Cultivadas , Hepatocitos/citología , Hepatocitos/metabolismo , Hepatocitos/patología , Humanos , Células Madre Pluripotentes Inducidas/metabolismo , Hígado/patología , Masculino , Células Madre Mesenquimatosas/metabolismo , Ratones Endogámicos C57BL , Daño por Reperfusión/metabolismo , Daño por Reperfusión/patología , Transducción de Señal , Esfingosina/metabolismoRESUMEN
Long non-coding RNAs (LncRNAs) are a category of non-coding RNAs (ncRNAs) with a length of 200nt-100kb lacking a significant open reading frame. The study of lncRNAs is a newly established field, due in part to their capability to act as the novel biomarkers in disease. A growing body of research shows that lncRNAs may not only useful as biomarkers for the diagnosis and clinical typing and prognosis of cancers, but also as potential targets for novel therapies. Differential expression of lncRNAs has been found in leukemia in the last two years, however, the majority of the lncRNAs described here are transcripts of unknown function and their role in leukemogenesis is still unclear. Here, we summarize the lncRNAs associated with leukemia in order to find a potential classification tool for leukemia, and a new field of research is being explored.
Asunto(s)
Biomarcadores de Tumor/genética , Leucemia/diagnóstico , ARN Largo no Codificante/genética , Regulación Neoplásica de la Expresión Génica , Redes Reguladoras de Genes , Humanos , Leucemia/genética , PronósticoRESUMEN
Dichloroacetonitrile (DCAN), one of the disinfection byproducts of water chlorination, induces cell proliferation and apoptosis; however, the detailed mechanism remains unclear. Oxidative stress participates in various biological processes, including DNA damage and cytotoxicity. To explore whether oxidative stress mediated DCAN-induced cell proliferation and apoptosis, we assessed the effect of redox imbalance and apoptosis in LO2 cells. We observed increase of reactive oxygen species and malondialdehyde and increased apoptosis by 13.6% in 500 µM DCAN compared with the control group. We also observed a decrease of antioxidant ability damage including glutathione, superoxide dismutase, and total antioxidant capacity depletion. Furthermore, DCAN might activate oxidative stress-mediated apoptosis pathway via up-regulation of p53 expression and caspase-3 activity. Therefore, we conclude that DCAN may activate apoptotic signals via p53 up-regulation and oxidative stress-mediated apoptosis in LO2 cells.
Asunto(s)
Acetonitrilos/toxicidad , Apoptosis/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Proteína p53 Supresora de Tumor/fisiología , Apoptosis/fisiología , Caspasa 3/metabolismo , Línea Celular , Proliferación Celular/efectos de los fármacos , Humanos , Malondialdehído/metabolismo , Especies Reactivas de Oxígeno/metabolismoRESUMEN
Oxidative stress has a critical role in the pathogenesis of acetaminophen (APAP) induced hepatocellular necrosis, and the identification of novel approaches to attenuate oxidative stress is essential to prevent/revert the disease. This study investigated the role of both HIF-1 and HIF-2 in the pathogenesis of APAP-induced oxidative stress, as well as the underlying mechanisms. In the present study, we initially found that knockout of HIF-1α or HIF-2α reduced APAP toxicity, and double knockout afforded the best protection. APAP treatment led to stabilization of both HIF-1α and HIF-2α in mouse livers. Moreover, the protective effects of HIF deficiency were related to the attenuated oxidative stress. Further experiments proved that PPARα, a master regulator in cellular metabolism accounted for the HIF deficiency-caused protective impact on APAP toxicity. Inactivation of HIFs promoted the expression of peroxisome proliferator-activated receptor α (PPARα) in the liver, which in turn activated nuclear factor erythroid 2-related factor 2 (Nrf2). Knockdown of PPARα or Nrf2 negated the hepatoprotection afforded by HIF deficiency. At lastï¼examination of the PPARα promoter identified a HIF-binding site and HIF-dependent repression of PPARα in hepatocytes by luciferase reporter and EMSA study. Taken togetherï¼ Our results demonstrate that HIFs are key suppressors of PPARα in the liver, thereby compromising the adaptive defense mechanisms against oxidative stress when confronted with APAP. These findings are important to the etiology and therapeutics of APAP hepatotoxicity. The functional link between HIFs and PPARα may have more implications in liver physiology and other pathologic conditions than APAP injury.
Asunto(s)
Acetaminofén/efectos adversos , Analgésicos no Narcóticos/efectos adversos , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Enfermedad Hepática Inducida por Sustancias y Drogas/genética , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , PPAR alfa/genética , Animales , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/deficiencia , Enfermedad Hepática Inducida por Sustancias y Drogas/metabolismo , Enfermedad Hepática Inducida por Sustancias y Drogas/patología , Citocromo P-450 CYP1A2/genética , Citocromo P-450 CYP1A2/metabolismo , Citocromo P-450 CYP2E1/genética , Citocromo P-450 CYP2E1/metabolismo , Citocromo P-450 CYP3A/genética , Citocromo P-450 CYP3A/metabolismo , Regulación de la Expresión Génica , Genes Reporteros , Hepatocitos/efectos de los fármacos , Hepatocitos/metabolismo , Hepatocitos/patología , Subunidad alfa del Factor 1 Inducible por Hipoxia/deficiencia , Hígado/efectos de los fármacos , Hígado/metabolismo , Hígado/patología , Luciferasas/genética , Luciferasas/metabolismo , Masculino , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Ratones , Ratones Noqueados , Factor 2 Relacionado con NF-E2/genética , Factor 2 Relacionado con NF-E2/metabolismo , Estrés Oxidativo , PPAR alfa/metabolismo , Cultivo Primario de Células , Transducción de SeñalRESUMEN
Hydroquinone (HQ), one of the most important metabolites derived from benzene, induces cell cycle arrest and apoptosis. Poly(ADP-ribose) polymerase-1 (PARP-1) participates in various biological processes, including DNA repair and cell cycle regulation. To explore whether PARP-1 regulatory pathway mediated HQ-induced cell cycle arrest and apoptosis, we assessed the effect of PARP-1 suppression on induction of apoptosis analyzed by FACSCalibur flow cytometer in PARP-1 deficientTK6 cells (TK6-shPARP-1). We observed an increase in the fraction of cells in G1 phase by 7.6% and increased apoptosis by 4.5% in PARP-1-deficient TK6 cells (TK6-shPARP-1) compared to those negative control cells (TK6-shNC cells) in response to HQ treatment. Furthermore, HQ might activate the extrinsic pathways of apoptosis via up-regulation of Fas expression, followed by caspase-3 activation, apoptotic body, and sub G1 accumulation. Enhanced p53 expression was observed in TK6-shPARP-1 cells than in TK6-shNC cells after HQ treatment. In contrast, Fas expression was lower in TK6-shPARP-1 cells than in TK6-shNC cells. Therefore, we conclude that HQ may activate apoptotic signals via Fas up-regulation and p53-mediated apoptosis in TK6-shNC cells. The reduction of PARP-1 expression further intensified up-regulation of p53 in TK6-shPARP-1 cells, resulting in an increased G1âS phase cell arrest and apoptosis in TK6-shPARP-1 cells compared to TK6-shNC cells.
Asunto(s)
Apoptosis/efectos de los fármacos , Hidroquinonas/toxicidad , Poli(ADP-Ribosa) Polimerasa-1/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Caspasa 3/metabolismo , Puntos de Control del Ciclo Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Activación Enzimática , Humanos , Interferencia de ARN , Regulación hacia Arriba , Receptor fas/metabolismoRESUMEN
In view of the rapid development of gene chips and high-throughput sequencing technology, noncoding RNAs (ncRNas) form a high percentage of the mammalian genome. Two major subgroups of ncRNAs that have been identified are the long ncRNAs (lncRNas) and the microRNAs. A number of studies in the past few years have showed crucial functions for lncRNas in cancer. LincRNa-p21 as a p53-dependent transcriptional target gene and a potential diagnostic marker is involved in proliferation, cell cycle, metabolism and reprogramming. In addition, more researches revealed that lincRNa-p21 is associated with cancer progression and contributed to the treatment and prognosis of cancer. In this review, we briefly summarize the function and molecular mechanisms of lincRNa-p21 in cancer and its regulation for the genes expression .
Asunto(s)
Neoplasias/genética , ARN Largo no Codificante/genética , Ciclo Celular/genética , Proliferación Celular/genética , Reprogramación Celular/genética , Humanos , Neoplasias/patología , ARN Largo no Codificante/metabolismoRESUMEN
Hydroquinone (HQ), one of the metabolic products of benzene, is a carcinogen. It can induce apoptosis in lymphoma cells. However, whether HQ can induce autophagy and what roles autophagy plays in TK6 cells exposured to HQ remains unclear. In this study, we found that HQ could induce autophagy through techniques of qRT-PCR, Western blot, immunofluorescent assay of LC3 and transmission electron microscope. Furthermore, inhibiting autophagy using 3-methyladenine (3-MA) or chloroquine (CQ) significantly enhanced HQ-induced cell apoptosis, suggesting that autophagy may be a survival mechanism. Our study also showed that HQ activated PARP-1. Moreover, knockdown of PARP-1 strongly exhibited decreased autophagy related genes expression. In contrast, the absence of SIRT1 increased that. Altogether, our data provided evidence that HQ induced autophagy in TK6 cells and autophagy protected TK6 from HQ attack-induced injury in vitro, and the autophagy was partially mediated via activation of the PARP-1-SIRT1 signaling pathway.
Asunto(s)
Autofagia/efectos de los fármacos , Hidroquinonas/toxicidad , Poli(ADP-Ribosa) Polimerasa-1/genética , Sirtuina 1/genética , Adenina/análogos & derivados , Adenina/farmacología , Apoptosis/efectos de los fármacos , Autofagia/genética , Proteína 5 Relacionada con la Autofagia/genética , Beclina-1/genética , Línea Celular , Cloroquina/farmacología , Técnicas de Silenciamiento del Gen , Humanos , Peróxido de Hidrógeno/metabolismo , Proteínas Asociadas a Microtúbulos/genética , Sirolimus/farmacologíaRESUMEN
Sirtuin 1 (Sirt1) is a deacetylase that regulates many cellular processes in the liver, and so far its role in endotoxemic liver injury is elusive. So we conditionally inactivate Sirt1 in murine hepatocytes to determine its role in d-galactosamine (GalN)/lipopolysaccharide (LPS)-induced liver damage, which is a well-established experimental model mimicking septic liver injury and fulminant hepatitis. Ablation of Sirt1 shows remarkable protection against GalN/LPS-induced liver injury, which is a result of enhanced NF-κB response because knockdown of RelA/p65 negates the protective effect of Sirt1 knockout. Mechanistically, NF-κB p65 is maintained in a hyperacetylated, DNA-binding competent state in tumor necrosis factor-α (TNF-α)-challenged albumin-Cre+ (AlbCre+) hepatocytes. Transfection of hepatocytes with a recombinant acetylated p65 expression construct replicates the protection afforded by Sirt1 knockout. Transfection of AlbCre+ hepatocytes with a recombinant wild-type Sirt1 construct, rather than a deacetylase-defective one, compromises NF-κB activation and resensitizes hepatocytes to TNF-α-induced apoptosis. Taken together, our results demonstrate that Sirt1 deacetylates p65 and compromises NF-κB activity in hepatocytes when confronted with LPS/TNF-α stimulation, leading to increased susceptibility to endotoxemic injury. These findings identify a possible protein effector to maneuver the hepatic NF-κB signaling pathway under inflammatory circumstances and a feasible way to increase hepatocellular resistance to endotoxin/TNF-α toxicity.
Asunto(s)
Endotoxemia/metabolismo , Hígado/metabolismo , Hígado/patología , FN-kappa B/metabolismo , Sustancias Protectoras/metabolismo , Sirtuina 1/metabolismo , Acetilación/efectos de los fármacos , Animales , ADN/metabolismo , Endotoxemia/patología , Galactosamina , Técnicas de Silenciamiento del Gen , Hepatocitos/efectos de los fármacos , Hepatocitos/metabolismo , Hepatocitos/patología , Integrasas/metabolismo , Lipopolisacáridos , Hígado/efectos de los fármacos , Masculino , Ratones , Ratones Noqueados , Mutación/genética , Unión Proteica/efectos de los fármacos , Factor de Transcripción ReIA/metabolismo , Transfección , Factor de Necrosis Tumoral alfa/farmacologíaRESUMEN
Hydroquinone (HQ), known as one of the metabolic products of benzene, causes a number of hematologic malignancies. The study evaluated the potential mechanism of Sirtuin 1 (SIRT1) in HQ-induced TK6 cell malignant transformation. The data of our study show that short term exposure of TK6 cells to HQ led to a decrease expression of SIRT1. Knockdown of SIRT1 sensitized to the HQ-induced apoptosis in vitro and increased the expression of p53, p21 and γ-H2AX. Furthermore, chronic HQ-treated (20µM once a week for 19 weeks) caused carcinogenic transformation and was confirmed by abnormal cell proliferation, matrix metalloproteinase 9(MMP9) and subcutaneous tumor formation in nude mice. SIRT1 increased KRAS expression, and decreased H3K9 and H3K18 acetylation, inhibited p53 signaling and the level of caspase-3 in HQ-induced transformation cells. Taken together, these data suggest that SIRT1 is involved in HQ-induced malignant transformation associated with suppressing p53 signaling and activation of KRAS.
Asunto(s)
Transformación Celular Neoplásica/efectos de los fármacos , Regulación de la Expresión Génica/efectos de los fármacos , Hidroquinonas/toxicidad , Proteínas Proto-Oncogénicas p21(ras)/metabolismo , Sirtuina 1/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Animales , Antioxidantes/toxicidad , Línea Celular , Humanos , Ratones , Ratones Desnudos , Neoplasias Experimentales , Proteínas Proto-Oncogénicas c-bcl-2/genética , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Proteínas Proto-Oncogénicas p21(ras)/genética , ARN Mensajero/genética , ARN Mensajero/metabolismo , Sirtuina 1/genética , Proteína p53 Supresora de Tumor/genética , Regulación hacia ArribaRESUMEN
OBJECTIVES: In China, there have been an increasing number of migrant workers from rural to urban areas, and migrant workers have the highest incidence of occupational diseases. However, few studies have examined the impact of occupational stress on job burnout in these migrant workers. This study aimed to investigate the relationship between occupational stress and job burnout among migrant workers. DESIGN: This study used a cross-sectional survey. SETTING: This investigation was conducted in Dongguan city, Guangdong Province, China. PARTICIPANTS: 3806 migrant workers, aged 18-60â years, were randomly selected using multistage sampling procedures. PRIMARY AND SECONDARY OUTCOME MEASURES: Multistage sampling procedures were used to examine demographic characteristics, behaviour customs and job-related data. Hierarchical linear regression and logistic regression models were constructed to explore the relationship between occupational stress and burnout. RESULTS: Demographics, behaviour customs and job-related characteristics significantly affected on burnout. After adjusting for the control variable, a high level of emotional exhaustion was associated with high role overload, high role insufficiency, high role boundary, high physical environment, high psychological strain, high physical strain, low role ambiguity, low responsibility and low vocational strain. A high level of depersonalisation was associated with high role overload, high role ambiguity, high role boundary, high interpersonal strain, high recreation, low physical environment and low social support. A low level of personal accomplishment was associated with high role boundary, high role insufficiency, low responsibility, low social support, low physical environment, low self-care and low interpersonal strain. Compared to the personal resources, the job strain and personal strain were more likely to explain the burnout of rural-to-urban migrant workers in our study. CONCLUSIONS: The migrant workers have increased job burnouts in relation to occupational stress. Relieving occupational stress and maintaining an appropriate quantity and quality of work could be important measures for preventing job burnout among these workers.
Asunto(s)
Estrés Laboral/etiología , Migrantes/psicología , Adolescente , Adulto , Análisis de Varianza , Agotamiento Profesional/epidemiología , Agotamiento Profesional/etiología , China/epidemiología , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estrés Laboral/epidemiología , Salud Rural , Factores Socioeconómicos , Salud Urbana , Adulto JovenRESUMEN
Natural killer T (NKT) cells are the major early-acting immune cell type and fundamental immune modulators in ischemia-reperfusion injury (IRI). Because lymphocytes are exposed to various oxygen tensions under pathophysiologic conditions, we hypothesize that hypoxia-inducible factors (HIFs) have roles in NKT cell activation, and thus determine the final outcome of renal IRI. In this study, we used Lck-Cre transgenic mice to specifically disrupt HIF-2α in T/NKT cells and found that HIF-2α knockout led to upregulated Fas ligand expression on peripheral NKT cells, but not on conventional T cells. HIF-2α knockout promoted infiltration of NKT cells into ischemic kidneys and exacerbated IRI, which could be mitigated by in vivo NK1.1(+) cell depletion or Fas ligand blockade. Compared with wild-type NKT cells, HIF-2α(-/-) NKT cells adoptively transferred to Rag1-knockout mice elicited more severe renal injury, and these mice were not protected by CGS21680, an adenosine A2A receptor agonist. Mechanistically, hypoxia-induced expression of adenosine A2A receptor in NKT cells and CGS21680-induced cAMP production in thymocytes were HIF-2α-dependent. Hydrogen peroxide-induced Fas ligand expression on thymic wild-type NKT cells was significantly attenuated by CGS21680 treatment, but this effect was lost in HIF-2α(-/-) NKT cells. Finally, CGS21680 and LPS, an inducer of HIF-2α in endothelium, synergistically reduced renal IRI substantially, but this effect was absent in Mx1-Cre-induced global HIF-2α-knockout mice. Taken together, our results reveal a hypoxia/HIF-2α/adenosine A2A receptor axis that restricts NKT cell activation when confronted with oxidative stress and thus protects against renal IRI.