Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 881
Filtrar
1.
Ecotoxicol Environ Saf ; 188: 109908, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31706243

RESUMO

Pesticides have been extensively produced and used to help the agricultural production which leads to the contamination of the environment, soil, groundwater sources, and even foodstuffs. Fungicides carbendazim (CBZ) and chlorothalonil (Chl) are widely applied in agriculture and other aspects. CBZ or Chl have been reported to disrupt spermatogenesis and decrease semen quality. However, it is not understood the effects of pubertal exposure to low doses of CBZ and Chl together, and the underlying mechanisms. Therefore, the aim of current investigation was to explore the negative impacts of pubertal exposure to low doses of CBZ and Chl together on spermatogenesis and the role of epigenetic modifications in the process. We demonstrated that CBZ and Chl together synergize to decrease sperm motility in vitro (CBZ 1.0 + Chl 0.1, CBZ 10.0 + CHl 1.0, CBZ 100.0 + Chl 10 µM in incubation medium for 24 h) and sperm concentration and motility in vivo with ICR mice (CBZ 0.1 + Chl 0.1, CBZ 1.0 + CHl 1.0, CBZ 10.0 + Chl 10 mg/kg body weight; oral gavage for five weeks). CBZ + Chl significantly increase reactive oxygen species (ROS) and apoptosis by the increase in the protein level of caspase 8 in vitro. Moreover, CBZ + Chl synergized to disrupt mouse spermatogenesis with the disturbance in sperm production proteins and sperm proteins (VASA, A-Myb, STK31, AR, Acrosin). CBZ + Chl synergized to decrease the protein level of estrogen receptor alpha and the protein level of DNA methylation marker 5 mC in Leydig cells, and to increase the protein levels of histone methylation marker H3K9 and the methylation enzyme G9a in germ cells. Therefore, greater attention should be paid to the use of CBZ and Chl as pesticides to minimise their adverse impacts on spermatogenesis.


Assuntos
Benzimidazóis/toxicidade , Carbamatos/toxicidade , Epigênese Genética/efeitos dos fármacos , Fungicidas Industriais/toxicidade , Nitrilos/toxicidade , Espermatogênese/efeitos dos fármacos , Animais , Sinergismo Farmacológico , Receptor alfa de Estrogênio/metabolismo , Masculino , Metilação/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos ICR , Transdução de Sinais/efeitos dos fármacos , Espermatogênese/genética , Espermatozoides/efeitos dos fármacos
2.
Res Vet Sci ; 126: 207-212, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31610471

RESUMO

To explore the effect of epigenetic modification on the differentiation of goat adipose-derived stem cells in vitro, we used two common epigenetic modification inhibitors, trichostatin A and vorinostat, to treat cashmere goat adipose-derived stem cells and induce adipocyte differentiation. The results showed that trichostatin A and vorinostat changed the relative amounts of H3K9 acetylation and dimethylation in the upstream sequence of PPARG, increased peroxisome proliferator-activated receptor gamma (PPARG) transcription before differentiation and then promoted adipocyte differentiation, and regulated the expression of adipocyte-specific genes. We conclude that adipocyte differentiation is regulated dynamically by different histone modifications. The areas of acetylation and demethylation changed by trichostatin A and vorinostat are the basis for further research on the mechanism of PPARG promoter to regulate adipocytes differentiation and provide research theroies for using adipose-derived stem cells as donor to produce transgenic animals to improve meat quality improvement.


Assuntos
Adipogenia/efeitos dos fármacos , Epigênese Genética/efeitos dos fármacos , Cabras/fisiologia , Inibidores de Histona Desacetilases/farmacologia , Ácidos Hidroxâmicos/farmacologia , Vorinostat/farmacologia , Acetilação/efeitos dos fármacos , Adipócitos/efeitos dos fármacos , Adipócitos/fisiologia , Animais , Metilação/efeitos dos fármacos , PPAR gama/metabolismo , Regiões Promotoras Genéticas/efeitos dos fármacos , Células-Tronco/efeitos dos fármacos , Células-Tronco/fisiologia
3.
Int J Mol Sci ; 20(20)2019 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-31615150

RESUMO

The micronutrients vitamins B9 and B12 act as methyl donors in the one-carbon metabolism involved in transmethylation reactions which critically influence epigenetic mechanisms and gene expression. Both vitamins are essential for proper development, and their deficiency during pregnancy has been associated with a wide range of disorders, including persisting growth retardation. Energy homeostasis and feeding are centrally regulated by the hypothalamus which integrates peripheral signals and acts through several orexigenic and anorexigenic mediators. We studied this regulating system in a rat model of methyl donor deficiency during gestation and lactation. At weaning, a predominance of the anorexigenic pathway was observed in deficient pups, with increased plasma peptide YY and increased hypothalamic pro-opiomelanocortin (POMC) mRNA, in line with abnormal leptin, ghrelin, and insulin secretion and/or signaling during critical periods of fetal and/or postnatal development of the hypothalamus. These results suggest that early methyl donor deficiency can affect the development and function of energy balance circuits, resulting in growth and weight deficits. Maternal administration of folic acid (3 mg/kg/day) during the perinatal period tended to rectify peripheral metabolic signaling and central neuropeptide and receptor expression, leading to reduced growth retardation.


Assuntos
Metabolismo Energético/genética , Grelina/genética , Peptídeo YY/genética , Pró-Opiomelanocortina/genética , Animais , Depressores do Apetite/farmacologia , Metabolismo Energético/efeitos dos fármacos , Comportamento Alimentar/efeitos dos fármacos , Feminino , Ácido Fólico/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/genética , Grelina/sangue , Hipotálamo/metabolismo , Insulina/sangue , Insulina/genética , Lactação , Leptina/sangue , Leptina/genética , Metilação/efeitos dos fármacos , Peptídeo YY/sangue , Gravidez , Pró-Opiomelanocortina/sangue , RNA Mensageiro/genética , Ratos , Vitamina B 12/genética , Vitamina B 12/farmacologia
4.
Eur J Med Chem ; 183: 111715, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31550663

RESUMO

Multiple myeloma (MM) is an incurable hematological malignancy driven by several genetic and epigenetic alterations. The hyperactivation of the Polycomb repressive complex 2 (PRC2), a multi-subunit oncogenic histone methyltransferase, has been implicated in the pathogenesis of this malignancy. Upon protein-protein interaction (PPI) between the catalytic subunit EZH2 and EED, PRC2 primarily methylates lysine 27 of histone H3 (H3K27me3), thus modulating the chromatin structure and inducing transcriptional repression. Herein, we highlight a new mechanism of action that can contribute to explain the anti-tumor activity of hydroxychloroquine (HCQ), an anti-malaric agent also known as autophagy inhibitor. By structural studies, we demonstrate that HCQ inhibits the allosteric binding of PRC2 to EED within the H3K27me3-binding pocket, thus antagonizing the PRC2 catalytic activity. In silico results are compatible with the significant reduction of the H3K27me3 levels in MM cells exerted by HCQ. Overall, these findings disclose a novel epigenetic activity of HCQ with potential implications for its clinical repositioning.


Assuntos
Antineoplásicos , Epigênese Genética/efeitos dos fármacos , Hidroxicloroquina , Complexo Repressor Polycomb 2/antagonistas & inibidores , Antineoplásicos/química , Antineoplásicos/farmacologia , Reposicionamento de Medicamentos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Histonas/metabolismo , Humanos , Hidroxicloroquina/química , Hidroxicloroquina/farmacologia , Metilação/efeitos dos fármacos
5.
Molecules ; 24(18)2019 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-31505804

RESUMO

The screening of drug metabolites in biological matrixes and structural characterization based on product ion spectra is among the most important, but also the most challenging due to the significant interferences from endogenous species. Traditionally, metabolite detection is accomplished primarily on the basis of predicted molecular masses or fragmentation patterns of prototype drug metabolites using ultra-high performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-HRMS). Although classical techniques are well-suited for achieving the partial characterization of prototype drug metabolites, there is a pressing need for a strategy to enable comprehensive drug metabolism depiction. Therefore, we present drug metabolite clusters (DMCs), different from, but complementary to, traditional approaches for mining the information regarding drugs and their metabolites on the basis of raw, processed, or identified tandem mass spectrometry (MS/MS) data. In this paper, we describe a DMC-based data-mining method for the metabolite identification of 5-hydroxy-6,7,3',4'-tetramethoxyflavone (HTF), a typical hydroxylated-polymethoxyflavonoid (OH-PMF), which addressed the challenge of creating a thorough metabolic profile. Consequently, eight primary metabolism clusters, sixteen secondary metabolism clusters, and five tertiary metabolism clusters were proposed and 106 metabolites (19 potential metabolites included) were detected and identified positively and tentatively. These metabolites were presumed to generate through oxidation (mono-oxidation, di-oxidation), methylation, demethylation, methoxylation, glucuronidation, sulfation, ring cleavage, and their composite reactions. In conclusion, our study expounded drug metabolites in rats and provided a reference for further research on therapeutic material basis and the mechanism of drugs.


Assuntos
Mineração de Dados , Flavonas/metabolismo , Metaboloma/efeitos dos fármacos , Animais , Cromatografia Líquida de Alta Pressão , Desmetilação/efeitos dos fármacos , Flavonas/farmacologia , Humanos , Hidroxilação/efeitos dos fármacos , Hidroxilação/genética , Metaboloma/genética , Metilação/efeitos dos fármacos , Oxirredução/efeitos dos fármacos , Ratos , Espectrometria de Massas em Tandem
6.
Ecotoxicol Environ Saf ; 184: 109606, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31472382

RESUMO

Epidemiological and animal studies have revealed a possible linkage between 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) exposure and neurodegenerative disease such as Parkinson's disease (PD). However, whether or how BDE-47 would affect the PD progression remains unclear. Here, we carried out a metabolomics study based on liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS) to investigate the possible contribution of BDE-47 exposure to PD progression in Drosophila (fly) model. Transgenic PD flies were exposed to BDE-47 through diet for 30 days. Global metabolomic analysis identified 48 altered metabolites after the exposure. These metabolites were mainly involved in tryptophan metabolism, phenylalanine metabolism, purine metabolism, and alanine, aspartate and glutamate metabolism. Further, by quantifying metabolites of interest using LC-MS/MS, we confirmed that the formation of neuro-protector kynurenic acid was slowed down while the formation of neurotoxin 3-hydroxy-kynurenine was speeded up on the 20th exposure day. Moreover, the levels of SAM/SAH (an index of methylation potential) and GSH/GSSG (an indicator of oxidative stress) were found to decrease on the 30th exposure day. Our results suggest that BDE-47 could induce imbalance of kynurenine metabolism and methylation potential, and oxidative stress, which might further accelerate PD progression.


Assuntos
Exposição Dietética , Drosophila/efeitos dos fármacos , Éteres Difenil Halogenados/toxicidade , Animais , Modelos Animais de Doenças , Drosophila/metabolismo , Doenças Metabólicas/etiologia , Doenças Metabólicas/metabolismo , Redes e Vias Metabólicas/efeitos dos fármacos , Metabolômica , Metilação/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos
7.
Eur J Pharm Sci ; 140: 105072, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31518680

RESUMO

Isocitrate dehydrogenase 1 mutations have been discovered in an array of hematologic malignancies and solid tumors. These mutations could cause the production of high levels of 2-hydroxyglutarate, which in turn implicated in epigenetic changes and impaired cell differentiation. Here, we described the characterization of compound I-8, a novel mutant IDH1 inhibitor, both in vitro and in vivo. Compound I-8 specifically inhibited 2-HG production, reduced histone methylation levels, induced differentiation and depleted stem characteristics in engineered and endogenous IDH1 mutant cells. In addition, oral administration of I-8 also significantly suppressed 2-HG production and histone methylation with dose of 150 mg/kg. And I-8 treatment also could induce differentiation and attenuate stem characteristics in tumor tissue. Together, these studies indicated that compound I-8 has clinical potential in tumor therapies as a effective mutant IDH1 inhibitor, and provided scientific guidance for the development of mutant IDH1 inhibitor in the future.


Assuntos
Antineoplásicos/química , Inibidores Enzimáticos/química , Isocitrato Desidrogenase/antagonistas & inibidores , Actinas/metabolismo , Animais , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Epigênese Genética , Glutaratos/metabolismo , Histonas/metabolismo , Humanos , Isocitrato Desidrogenase/genética , Metilação/efeitos dos fármacos , Camundongos Endogâmicos BALB C , Camundongos Nus , Simulação de Acoplamento Molecular , Mutação , Ligação Proteica , Conformação Proteica
8.
Mol Cell ; 75(6): 1147-1160.e5, 2019 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-31420217

RESUMO

Activated macrophages adapt their metabolic pathways to drive the pro-inflammatory phenotype, but little is known about the biochemical underpinnings of this process. Here, we find that lipopolysaccharide (LPS) activates the pentose phosphate pathway, the serine synthesis pathway, and one-carbon metabolism, the synergism of which drives epigenetic reprogramming for interleukin-1ß (IL-1ß) expression. Glucose-derived ribose and one-carbon units fed by both glucose and serine metabolism are synergistically integrated into the methionine cycle through de novo ATP synthesis and fuel the generation of S-adenosylmethionine (SAM) during LPS-induced inflammation. Impairment of these metabolic pathways that feed SAM generation lead to anti-inflammatory outcomes, implicating SAM as an essential metabolite for inflammatory macrophages. Mechanistically, SAM generation maintains a relatively high SAM:S-adenosylhomocysteine ratio to support histone H3 lysine 36 trimethylation for IL-1ß production. We therefore identify a synergistic effect of glucose and amino acid metabolism on orchestrating SAM availability that is intimately linked to the chromatin state for inflammation.


Assuntos
Histonas/metabolismo , Macrófagos Peritoneais/metabolismo , S-Adenosilmetionina/metabolismo , Trifosfato de Adenosina/metabolismo , Adulto , Animais , Feminino , Humanos , Inflamação/induzido quimicamente , Inflamação/metabolismo , Inflamação/patologia , Interleucina-1beta/metabolismo , Lipopolissacarídeos/toxicidade , Macrófagos Peritoneais/patologia , Masculino , Metilação/efeitos dos fármacos , Camundongos
9.
Anticancer Res ; 39(8): 4179-4184, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31366503

RESUMO

BACKGROUND/AIM: Enhancer of zeste homolog 2 (EZH2), the catalytic subunit of polycomb repressive complex 2 (PRC2), possesses histone N-methyltransferase (HMT) activity and plays an essential role in cancer initiation and development. The aim of the present study was to investigate the potential of Wedelolactone (WL) to inhibit the methylation activity of EZH2. MATERIALS AND METHODS: The mantle cell lymphoma (MCL) cell line, Mino, was treated with WL, while untreated cells were used as control. HMT activity and EZH2 amount were measured in nuclear extracts from WL-treated and control Mino cells. RESULTS: WL was found to target EZH2-mediated histone H3K27 methylation. Along with the inhibition of H3K27 methylation in vitro (IC50=0.3 µM), WL suppressed HMT activity in Mino cells with an IC50 value of 3.2 µM. We detected a reduced amount of EZH2 in Mino cells treated with WL, compared to untreated control cells. CONCLUSION: This is the first study to show that WL induces inhibition of H3K27 methylation via EZH2 modulation and decreases cell proliferation in MCL, in vitro. WL is proposed as a promising agent and a novel epigenetic approach in MCL investigation and treatment.


Assuntos
Cumarínicos/farmacologia , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Código das Histonas/genética , Linfoma de Célula do Manto/tratamento farmacológico , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Código das Histonas/efeitos dos fármacos , Histona Metiltransferases/genética , Histona Metiltransferases/metabolismo , Histonas/genética , Histonas/metabolismo , Humanos , Linfoma de Célula do Manto/genética , Linfoma de Célula do Manto/patologia , Metilação/efeitos dos fármacos , Complexo Repressor Polycomb 2/genética
10.
Biomed Res Int ; 2019: 3924581, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31355259

RESUMO

This study investigated the effects of proanthocyanidins (PC) on arsenic methylation metabolism and efflux in human hepatocytes (L-02), as well as the relationships between PC and GSH, MRP1 and other molecules. Cells were randomly divided into blank control group, arsenic trioxide exposure group (ATO, As2O3, 25µmol/L), and PC-treated arsenic exposure group (10, 25, 50mg/L). After 24/48h, the contents of different forms of arsenic were determined, and the methylation indexes were calculated. Intracellular S-adenosyl methionine (SAM), arsenic (+3 oxidation state) methyltransferase (AS3MT), multidrug resistance-associated protein 1 (MRP1), and reduced glutathione (GSH) were ascertained. Changing trends were observed and the correlation between arsenic metabolism and efflux related factors and arsenic metabolites was analyzed. We observed that cells showed increased levels of content/constituent ratio of methyl arsenic, primary/secondary methylation index, methylation growth efficiency/rate, and the difference of methyl arsenic content in cells and culture medium (P<0.05, resp.). Compared with ATO exposure group, the intracellular SAM content in PC-treated group decreased, and the contents of GSH, AS3MT, and MRP1 increased (P<0.05, resp.). There was a positive correlation between the content of intracellular GSH/AS3MT and methyl arsenic. The content of MRP1 was positively correlated with the difference of methyl arsenic content in cell and culture medium; conversely, the SAM content was negatively correlated with intracellular methyl arsenic content (P<0.05, resp.). Taken together, these results prove that PC can promote arsenic methylation metabolism and efflux in L-02 cells, which may be related to the upregulation of GSH, MRP1, and AS3MT levels by PC.


Assuntos
Arsênico/metabolismo , Hepatócitos/efeitos dos fármacos , Oxirredução/efeitos dos fármacos , Proantocianidinas/farmacologia , Arsênico/química , Trióxido de Arsênio/química , Trióxido de Arsênio/metabolismo , Transporte Biológico , Regulação da Expressão Gênica/efeitos dos fármacos , Glutationa/genética , Humanos , Metilação/efeitos dos fármacos , Metiltransferases/genética , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética
11.
Nucleic Acids Res ; 47(14): 7333-7347, 2019 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-31165872

RESUMO

Although combination antiretroviral therapy is potent to block active replication of HIV-1 in AIDS patients, HIV-1 persists as transcriptionally inactive proviruses in infected cells. These HIV-1 latent reservoirs remain a major obstacle for clearance of HIV-1. Investigation of host factors regulating HIV-1 latency is critical for developing novel antiretroviral reagents to eliminate HIV-1 latent reservoirs. From our recently accomplished CRISPR/Cas9 sgRNA screens, we identified that the histone demethylase, MINA53, is potentially a novel HIV-1 latency-promoting gene (LPG). We next validated MINA53's function in maintenance of HIV-1 latency by depleting MINA53 using the alternative RNAi approach. We further identified that in vitro MINA53 preferentially demethylates the histone substrate, H3K36me3 and that in cells MINA53 depletion by RNAi also increases the local level of H3K36me3 at LTR. The effort to map the downstream effectors unraveled that H3K36me3 has the cross-talk with another epigenetic mark H4K16ac, mediated by KAT8 that recognizes the methylated H3K36 and acetylated H4K16. Removing the MINA53-mediated latency mechanisms could benefit the reversal of post-integrated latent HIV-1 proviruses for purging of reservoir cells. We further demonstrated that a pan jumonji histone demethylase inhibitor, JIB-04, inhibits MINA53-mediated demethylation of H3K36me3, and JIB-04 synergizes with other latency-reversing agents (LRAs) to reactivate latent HIV-1.


Assuntos
Sistemas CRISPR-Cas , Dioxigenases/genética , Infecções por HIV/genética , HIV-1/genética , Histona Desmetilases/genética , Proteínas Nucleares/genética , Latência Viral/genética , Aminopiridinas/farmacologia , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD4-Positivos/virologia , Linhagem Celular Tumoral , Células Cultivadas , Desmetilação/efeitos dos fármacos , Dioxigenases/antagonistas & inibidores , Dioxigenases/metabolismo , Regulação Viral da Expressão Gênica/efeitos dos fármacos , Células HEK293 , Infecções por HIV/metabolismo , Infecções por HIV/virologia , HIV-1/efeitos dos fármacos , HIV-1/fisiologia , Inibidores de Histona Desacetilases/farmacologia , Histona Desmetilases/antagonistas & inibidores , Histona Desmetilases/metabolismo , Histonas/metabolismo , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Interações Hospedeiro-Patógeno/genética , Humanos , Hidrazonas/farmacologia , Metilação/efeitos dos fármacos , Proteínas Nucleares/antagonistas & inibidores , Proteínas Nucleares/metabolismo , Interferência de RNA
12.
Curr Top Med Chem ; 19(15): 1350-1362, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31215380

RESUMO

Macrophages are essential for supporting tissue homeostasis, regulating immune response, and promoting tumor progression. Due to its heterogeneity, macrophages have different phenotypes and functions in various tissues and diseases. It is becoming clear that epigenetic modification playing an essential role in determining the biological behavior of cells. In particular, changes of DNA methylation, histone methylation and acetylation regulated by the corresponding epigenetic enzymes, can directly control macrophages differentiation and change their functions under different conditions. In addition, epigenetic enzymes also have become anti-tumor targets, such as HDAC, LSD1, DNMT, and so on. In this review, we presented an overview of the latest progress in the study of macrophages phenotype and function regulated by epigenetic modifications, including DNA methylation and histone modifications, to better understand how epigenetic modification controls macrophages phenotype and function in inflammation-associated diseases, and the application prospect in anti-tumor.


Assuntos
Antineoplásicos/farmacologia , Epigênese Genética/efeitos dos fármacos , Inflamação/tratamento farmacológico , Macrófagos/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Acetilação/efeitos dos fármacos , Animais , Antineoplásicos/química , Metilação de DNA/efeitos dos fármacos , Epigênese Genética/genética , Histonas/efeitos dos fármacos , Histonas/metabolismo , Humanos , Inflamação/metabolismo , Inflamação/patologia , Macrófagos/metabolismo , Macrófagos/patologia , Metilação/efeitos dos fármacos , Neoplasias/metabolismo , Neoplasias/patologia
13.
Mol Med Rep ; 19(6): 4989-4997, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31059019

RESUMO

The pathological process of Parkinson's disease (PD) is closely associated with the death of nigral neurons, for which an effective treatment has yet to be found. Lithium, one of the most widely certified anticonvulsant and mood­stabilizing agents, exhibits evident neuroprotective effects in the treatment of epilepsy and bipolar disorder. In the present study, the neuroprotective mechanisms by which lithium acts on a chronic 1­methyl­4­phenyl­1,2,3,6­tetrahydropyridine (MPTP) mouse model of PD were investigated by employing animal behavioral tests, immunohistochemistry, RT­PCR, and western blotting. The results revealed that, in open field tests, lithium treatment counteracted the reduction in movement distance as well as activity time induced by MPTP administration. The compound could also prolong the drop time of MPTP­treated mice in rotarod tests. Moreover, lithium treatment corrected the loss of nigral neurons, the increase of α­synuclein (SNCA) in substantia nigra as well as in the striatum of MPTP­treated mice, and decreased the methylation of SNCA intron 1 in DNA from the same regions. Furthermore, marked changes were observed in the expression of miRNAs including miR­148a, a potential inhibitor of DNMT1, in the MPTP­treated mice. These results suggested that the early application of lithium was important for alleviating the behavioral deficits experienced in the PD model, and that the neuroprotective action of lithium was achieved through a lithium­triggered miRNA regulation mechanism. Essentially, our findings indicated that lithium may be beneficial in the prevention and treatment of PD through the regulation of α­synuclein methylation.


Assuntos
Lítio/uso terapêutico , Intoxicação por MPTP/tratamento farmacológico , Fármacos Neuroprotetores/uso terapêutico , alfa-Sinucleína/metabolismo , Animais , Comportamento Animal/efeitos dos fármacos , DNA (Citosina-5-)-Metiltransferase 1/metabolismo , Modelos Animais de Doenças , Íntrons , Lítio/farmacologia , Intoxicação por MPTP/patologia , Masculino , Metilação/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/metabolismo , Fármacos Neuroprotetores/farmacologia , Substância Negra/efeitos dos fármacos , Substância Negra/metabolismo , Substância Negra/patologia , alfa-Sinucleína/genética
14.
Plant Sci ; 284: 16-24, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31084868

RESUMO

In this paper, we evaluated the genotoxicity of cadmium (Cd) in plants by performing a methylation-sensitive amplification polymorphism (MSAP) on the model plant Nicotiana benthamiana. Among 255 loci examined, 14 genes were found to show altered cytosine methylation patterns in response to Cd stress. Four of those genes (NbMORC3, NbHGSNAT, NbMUT, and NbBG) were selected for further analysis due to their predicted roles in plant development. Cd-induced changes of cytosine methylation status in MSAP fragments of selected genes were confirmed using bisulfite sequencing polymerase chain reaction (BSP). In addition, the expression levels of these genes were found to correlate with cadmium dosage, and a knock-down of these four genes via virus-induced genes silencing (VIGS) led to abnormal development and elevated sensitivity to cadmium stress. Silencing of these four genes resulted in altered cadmium accumulation in different parts of the experimental plants. Our data indicate that cadmium exposure causes dramatic changes in the cytosine methylation status of the plant genome, thus affecting the expression of many genes that are vital for plant growth and are involved in cadmium stress response.


Assuntos
Cádmio/toxicidade , Citosina/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Tabaco/efeitos dos fármacos , DNA de Plantas/efeitos dos fármacos , Genes de Plantas/efeitos dos fármacos , Metilação/efeitos dos fármacos , Reação em Cadeia da Polimerase em Tempo Real , Estresse Fisiológico/efeitos dos fármacos , Tabaco/genética , Tabaco/metabolismo
15.
Environ Res ; 175: 228-234, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31146095

RESUMO

The epitranscriptome comprises more than 100 forms of RNA modifications. Of these, N6-methyladenosine (m6A) is the most abundantform of RNA methylation, with roles in modulating mRNA transcript processing and regulation. The aims of the study weretoexamine changes inm6A RNA methylation in A549 lung epithelial cells in response to environmental toxicants, anddifferential gene expression of m6A modulator genes ('readers', 'writers' and 'erasers') in human subjects exposed toparticulate matter (PM) and in lung cancer tissueusing publicly-available microarray datasets. Global m6A methylation levelsweremeasured in total RNA after exposuretotwo carcinogens (PM and sodium arsenite) for 24- and 48-h, and totwo endocrine disruptors (bisphenol A and vinclozolin)for 24-h.Global m6A methylation level significantly decreased with exposure to >62 µg/mlPM, >1 µM sodium arsenite, >1  µM bisphenol A (BPA), and0.1  µM vinclozolin. In an analysis of a published dataset derived from a population study, we observed that m6A writers (METTL3 and WTAP), erasers (FTO and ALKBH5) and readers (HNRPC) showed significantly higher expression among participants in the high-PM2.5exposure group compared to those in the low-exposure control group (all p < 0.05). Further, the m6A writer METTL3shows reduced expression in lung tumors in comparison to normal lung epithelia (p < 0.0001). Our findings reveal that m6A RNA methylation can be modified by exposure to environmental toxicants, and exposure to particulate matter is associated with differential expression level of m6A RNA methylation modification machinery.


Assuntos
Adenosina/análogos & derivados , Exposição Ambiental , Poluentes Ambientais/toxicidade , Metilação/efeitos dos fármacos , Adenosina/metabolismo , Dioxigenase FTO Dependente de alfa-Cetoglutarato , Humanos , Metiltransferases/metabolismo , Proteínas Nucleares , RNA
16.
Biochem J ; 476(12): 1741-1751, 2019 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-31138771

RESUMO

Podocytes are terminally differentiated and highly specialized glomerular cells, which have an essential role as a filtration barrier against proteinuria. Histone methylation has been shown to influence cell development, but its role in podocyte differentiation is less understood. In this study, we first examined the expression pattern of histone demethylase KDM6B at different times of cultured human podocytes in vitro We found that the expression of KDM6B and podocyte differentiation markers WT1 and Nephrin are increased in the podocyte differentiation process. In cultured podocytes, KDM6B knockdown with siRNA impaired podocyte differentiation and led to expression down-regulation of WT1 and Nephrin. The treatment of podocytes with GSK-J4, a specific KDM6B inhibitor, can also obtain similar results. Overexpression of WT1 can rescue differentiated phenotype impaired by disruption of KDM6B ChIP (chromatin immunoprecipitation) assay further indicated that KDM6B can bind the promoter region of WT1 and reduce the histone H3K27 methylation. Podocytes in glomeruli from nephrotic patients exhibited increased KDM6B contents and reduced H3K27me3 levels. These data suggest a role for KDM6B as a regulator of podocyte differentiation, which is important for the understanding of podocyte function in kidney development and related diseases.


Assuntos
Diferenciação Celular , Regulação Enzimológica da Expressão Gênica , Histona Desmetilases com o Domínio Jumonji/metabolismo , Podócitos/enzimologia , Benzazepinas/farmacologia , Histonas/metabolismo , Humanos , Histona Desmetilases com o Domínio Jumonji/antagonistas & inibidores , Proteínas de Membrana/metabolismo , Metilação/efeitos dos fármacos , Podócitos/citologia , Pirimidinas/farmacologia , Proteínas WT1/biossíntese
17.
Mol Med Rep ; 20(1): 323-331, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31115533

RESUMO

Hypermethylation of transcription factor activating enhancer­binding protein 2e (TFAP2E) has been reported to be associated with chemoresistance to 5­fluorouracil (5­FU) in gastric cancer (GC). In the present study, the molecular mechanism governing this chemoresistance was investigated. Drug­resistant human GC MGC­803/5­FU cells were established and TFAP2E expression and methylation levels were assessed. Autocrine exosomes from GC culture medium were isolated and characterized. MicroRNA (miRNA) microarray analysis was used to determine the miRNA expression profile of GC cell­derived exosomes. Exosomes collected from MGC­803/5­FU cells were co­cultured with control cells, and 5­Aza­2'­deoxycytidine (5Aza) was added into MGC­803/5­FU cells to investigate the relationship between TFAP2E, exosomes and chemosensitivity. In the present study, it was demonstrated that hypermethylation of TFAP2E resulted in its reduced expression and 5­FU chemoresistance in GC cells. miRNAs miR­106a­5p and miR­421 were highly expressed and regulated the chemoresistance induced by TFAP2E methylation. Target gene prediction using miRBase, TargetScan and PicTar revealed that E2F1, MTOR and STAT3 may be TFAP2E target genes in GC. Collectively, our data support an important role of exosomes and exosomal miRNAs in TFAP2E methylation­induced chemoresistance to 5­FU in GC. These results highlight their potential for miRNA­based therapeutics.


Assuntos
Fluoruracila/farmacologia , MicroRNAs/genética , Neoplasias Gástricas/tratamento farmacológico , Fator de Transcrição AP-2/genética , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Metilação de DNA , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Exossomos/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Metilação/efeitos dos fármacos , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia
18.
J Toxicol Sci ; 44(4): 309-316, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30944283

RESUMO

Cadmium, a ubiquitous heavy metal, is a toxic industrial and environmental pollutant. The initial biological response to cadmium exposure is induction of metallothioneins (MTs), a family of cysteine-rich, low-molecular-weight proteins that bind primarily zinc, cadmium, or both. This MT induction protects against cadmium toxicity by quenching cadmium. However, the effects of long-term cadmium exposure on MT1 gene expression are largely unknown. To investigate these effects, we used P1798 mouse lymphosarcoma cells, in which the MT1 gene is suppressed. As previously reported, MT1 expression remained unchanged after cadmium treatment. However, MT1 induction was observed in cells treated with 0.1 µM cadmium for 7 days, then exposed to 10 µM cadmium for 3 hr. In cells treated with 0.1 µM cadmium for 7 days, the transfected MT1 promoter reporter gene transcription and the cadmium incorporation in response to 10 µM cadmium induction were similar to those in untreated P1798 cells. Bisulfite genomic sequencing revealed that 7 day treatment with 0.1 µM cadmium slightly decreased CpG methylation in the 5´ flanking region of the MT1 gene. Our results together show that cadmium treatment results in MT1 induction and epigenetic modification of the MT1 gene.


Assuntos
Cádmio/toxicidade , Epigênese Genética/efeitos dos fármacos , Expressão Gênica/efeitos dos fármacos , Linfoma não Hodgkin/metabolismo , Metalotioneína/genética , Metalotioneína/metabolismo , Região 5'-Flanqueadora , Animais , Cádmio/metabolismo , Relação Dose-Resposta a Droga , Metilação/efeitos dos fármacos , Camundongos , Regiões Promotoras Genéticas/genética , Ligação Proteica/efeitos dos fármacos , Fatores de Tempo , Transcrição Genética/efeitos dos fármacos , Células Tumorais Cultivadas
19.
Cell Prolif ; 52(4): e12617, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31012173

RESUMO

OBJECTIVES: The roles and related mechanisms of six2 in regulating non-small cell lung cancer (NSCLC) cells progression are unclear. This work aimed to explore the roles of six2 in NSCLC cell stemness. MATERIALS AND METHODS: Kaplan-Meier plotter analysis was used to examine the correlation between six2 expression and the survival of NSCLC patients. Quantitative reverse transcription PCR and Western blot were performed to detect six2 expression in clinical samples. Moreover, transwell migration, tumour spheroid formation and in vivo tumour formation assays were used to examine the effects of six2 on NSCLC cell progression. Additionally, methylation analysis was carried out to measure E-cadherin methylation level in different cells. Finally, cell viability assay was performed to explore the effects of six2 on chemotherapeutic sensitivity of NSCLC cells. RESULTS: Lung cancer patients with a higher six2 expression level displayed a shorter overall survival. Six2 expression was higher in lung cancer tissues than in normal adjacent tissues. Additionally, six2 knockdown suppressed NSCLC cell stemness. Mechanistically, six2 overexpression inhibited epithelial marker E-cadherin expression via stimulating its promoter methylation. And E-cadherin knockdown rescued six2 knockdown-induced decrease of NSCLC cancer cell stemness. Notably, six2 knockdown enhanced cisplatin sensitivity in parental NSCLC cells and attenuated cisplatin resistance in cisplatin-resistant NSCLC cells. CONCLUSIONS: Our results suggest that six2 facilitates NSCLC cell stemness and attenuates chemotherapeutic sensitivity via suppressing E-cadherin expression.


Assuntos
Antígenos CD/genética , Caderinas/genética , Carcinoma Pulmonar de Células não Pequenas/genética , Epigênese Genética/genética , Proteínas de Homeodomínio/genética , Neoplasias Pulmonares/genética , Proteínas do Tecido Nervoso/genética , Transcrição Genética/genética , Células A549 , Animais , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Movimento Celular/genética , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Cisplatino/farmacologia , Progressão da Doença , Epigênese Genética/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/genética , Células HEK293 , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Masculino , Metilação/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Regiões Promotoras Genéticas/efeitos dos fármacos , Regiões Promotoras Genéticas/genética , Transcrição Genética/efeitos dos fármacos
20.
Oncogene ; 38(22): 4352-4365, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30770899

RESUMO

Anti-microtubule agents are frequently used as anticancer therapeutics. Cell death induced by these agents is considered to be due to sustained mitotic arrest caused by the activation of spindle assembly checkpoint (SAC). However, some cell types are resistant to mitotic cell death. Cells' ability to escape mitotic arrest (mitotic slippage) is thought to be a major mechanism contributing to this resistance. Here, we show that resistance to cell death induced by anti-mitotic agents is not linked to cells' capacity to undergo mitotic slippage as generally believed but is dependent on the state of BimEL regulation during mitosis. While transcriptional repression of BimEL in the mitotic death-resistant cells involves polycomb repressive complex 2 (PRC2)-mediated histone trimethylation, the BimEL protein is destabilized by cullin 1/4A-ßTrCP-dependent degradation involving activation of cullin 1/4A by neddylation. These results imply that pharmacological augmentation of BimEL activity in anti-microtubule drug-resistant tumors may have important therapeutic implications.


Assuntos
Proteína 11 Semelhante a Bcl-2/genética , Morte Celular/genética , Resistência a Medicamentos/genética , Microtúbulos/genética , Células A549 , Antineoplásicos/farmacologia , Proteínas de Ciclo Celular/genética , Morte Celular/efeitos dos fármacos , Linhagem Celular , Linhagem Celular Tumoral , Resistência a Medicamentos/efeitos dos fármacos , Células HEK293 , Células HeLa , Histonas/genética , Humanos , Pontos de Checagem da Fase M do Ciclo Celular/genética , Metilação/efeitos dos fármacos , Microtúbulos/efeitos dos fármacos , Mitose/efeitos dos fármacos , Mitose/genética , Complexo Repressor Polycomb 2/genética , Fuso Acromático/efeitos dos fármacos , Fuso Acromático/genética , Transcrição Genética/efeitos dos fármacos , Transcrição Genética/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA