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1.
J Agric Food Chem ; 68(5): 1337-1346, 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-31933359

RESUMO

The strong and inducible cbh1 promoter is most widely used to express heterologous proteins, useful in food and feed industries, in Trichoderma reesei. Enhancing its ability to direct transcription provides a general strategy to improve protein production in T. reesei. The cbh1 promoter was engineered by replacing eight binding sites of the transcription repressor ACE1 to those of the activators ACE2, Hap2/3/5, and Xyr1. While changing ACE1 to Hap2/3/5-binding sites completely abolished the transcription ability, replacements with ACE2- and Xyr1-binding sites (designated cbh1pA and cbh1pX promoters, respectively) largely improved the promoter transcription efficiency, as reflected by expression of a reporter gene DsRed. The cbh1pA and cbh1pX promoters were applied to improve secretory expression of a codon-optimized mannanase from Aspergillus niger to 3.6- and 5.0-fold higher, respectively, which has high application potential in feed industry.


Assuntos
Proteínas Fúngicas/metabolismo , Regiões Promotoras Genéticas , Proteínas Repressoras/metabolismo , Transativadores/metabolismo , Trichoderma/genética , Sítios de Ligação , Proteínas Fúngicas/genética , Regulação Fúngica da Expressão Gênica , Engenharia Genética , Ligação Proteica , Proteínas Repressoras/genética , Transativadores/genética , Trichoderma/metabolismo
2.
J Phys Chem Lett ; 11(3): 864-868, 2020 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-31940206

RESUMO

The transcriptional adaptor zinc-binding 1 (TAZ1) domain of the transcriptional coactivator CBP/P300 and two disordered peptides, HIF-1α and CITED2, form a delicate protein switch that regulates cellular hypoxic response. In hypoxia, HIF-1α binds TAZ1 to control the transcription of adaptive genes critical for the recovery from hypoxic stress. CITED2 acts as the negative feedback regulator to rapidly displace HIF-1α and efficiently attenuate the hypoxic response. Though CITED2 and HIF-1α have the same dissociation constant (Kd = 10 nM) in their binary complexes with TAZ1, CITED2 is much more competitive than HIF-1α upon binding the same target TAZ1 in ternary ( Berlow et al. Nature 2017 , 543 , 447 - 451 ). Here we demonstrate that a simple coarse-grained model can recapitulate this negative allosteric effect and provide detailed physical insights into the displacement mechanism. We find that long-range electrostatic forces are essential for the efficient displacement of HIF-1α by CITED2. The strong electrostatic interactions between CITED2 and TAZ1, along with the unique binding mode, make CITED2 much more competitive than HIF-1α in binding TAZ1.


Assuntos
Subunidade alfa do Fator 1 Induzível por Hipóxia/química , Proteínas Repressoras/química , Transativadores/química , Fatores de Transcrição de p300-CBP/química , Regulação Alostérica , Humanos , Modelos Moleculares , Ligação Proteica , Domínios Proteicos , Eletricidade Estática
3.
Medicine (Baltimore) ; 99(2): e18725, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31914088

RESUMO

The NOTCH signaling pathway plays a crucial role in cell phenotype and transformation. Single nucleotide polymorphisms (SNPs) may regulate gene expression to trigger bladder cancer susceptibility. Here, we aimed to explore the relationships between genetic variants in the NOTCH pathway and bladder cancer progression.We screened SNPs located in NOTCH pathway genes using the 1000 Genomes Project dataset (CHB). A case-control cohort study including 580 bladder cancer cases and 1101 controls was conducted to genotype the candidate SNPs. The expression quantitative trait locus (eQTL) and bioinformatics analyses were performed to explore the biological function of the SNPs' host gene and their relationship. Kaplan-Meier analysis was performed to assess the association between host gene expression and bladder cancer patient prognosis.The rs7944701 in the intron of mastermind-like 2 (MAML2) had the strongest signal and was related to bladder cancer risk (OR = 1.329, 95% CI = 1.115-1.583, P = .001). eQTL analysis showed that rs7944701 with a C allele was negatively associated with mastermind-like 2 (MAML2) expression (TT versus TC/CC). Bioinformatics analysis indicated that MAML2expression was lower in bladder cancer tissues than in non-tumor tissues (P = 5.46 × 10). Additionally, bladder cancer patients with high MAML2 expression had a significantly poorer prognosis (HR = 1.53, 95% CI = 1.29-1.82, P = .010).The rs7944701 in MAML2 was strongly associated with bladder cancer susceptibility in a Chinese population. This genetic variant and its host gene could be a potential novel biomarker for individuals suffering from bladder cancer.


Assuntos
Transativadores/genética , Neoplasias da Bexiga Urinária/genética , China , Feminino , Predisposição Genética para Doença , Genótipo , Humanos , Íntrons , Estimativa de Kaplan-Meier , Masculino , Polimorfismo de Nucleotídeo Único , Fatores de Risco , Transdução de Sinais
4.
Cancer Sci ; 111(1): 186-199, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31746077

RESUMO

Activity of transcriptional co-activator with PDZ binding domain (TAZ) protein is strongly implicated in the pathogenesis of human cancer and is influenced by tumor metabolism. High levels of lactate concentration in the tumor microenvironment as a result of metabolic reprogramming are inversely correlated with patient overall survival. Herein, we investigated the role of lactate in the regulation of the activity of TAZ and showed that glycolysis-derived lactate efficiently increased TAZ expression and activity in lung cancer cells. We showed that the reactive oxygen species (ROS) generated by lactate-fueled oxidative phosphorylation (OXPHOS) in mitochondria activated AKT and thereby inhibited glycogen synthase kinase 3 beta/beta-transducin repeat-containing proteins (GSK-3ß/ß-TrCP)-mediated ubiquitination and degradation of DNA methyltransferase 1 (DNMT1). Upregulation of DNMT1 by lactate caused hypermethylation of TAZ negative regulator of the LATS2 gene promoter, leading to TAZ activation. Moreover, TAZ binds to the promoter of DNMT1 and is necessary for DNMT1 transcription. Our study showed a molecular mechanism of DNMT1 in linking tumor metabolic reprogramming to the Hippo-TAZ pathway and functional significance of the DNMT1-TAZ feedback loop in the migratory and invasive potential of lung cancer cells.


Assuntos
DNA (Citosina-5-)-Metiltransferase 1/genética , Ácido Láctico/metabolismo , Estresse Oxidativo/genética , Transativadores/genética , Transcrição Genética/genética , Ativação Transcricional/genética , Linhagem Celular Tumoral , Glicogênio Sintase Quinase 3 beta/genética , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Regiões Promotoras Genéticas/genética , Ligação Proteica/genética , Espécies Reativas de Oxigênio/metabolismo
5.
Genes Dev ; 34(1-2): 53-71, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31857346

RESUMO

Hippo signaling controls organ size and tumor progression through a conserved pathway leading to nuclear translocation of the transcriptional effector Yki/Yap/Taz. Most of our understanding of Hippo signaling pertains to its cytoplasmic regulation, but how the pathway is controlled in the nucleus remains poorly understood. Here we uncover an evolutionarily conserved mechanism by which CDK7 promotes Yki/Yap/Taz stabilization in the nucleus to sustain Hippo pathway outputs. We found that a modular E3 ubiquitin ligase complex CRL4DCAF12 binds and targets Yki/Yap/Taz for ubiquitination and degradation, whereas CDK7 phosphorylates Yki/Yap/Taz at S169/S128/S90 to inhibit CRL4DCAF12 recruitment, leading to Yki/Yap/Taz stabilization. As a consequence, inactivation of CDK7 reduced organ size and inhibited tumor growth, which could be reversed by restoring Yki/Yap activity. Our study identifies an unanticipated layer of Hippo pathway regulation, defines a novel mechanism by which CDK7 regulates tissue growth, and implies CDK7 as a drug target for Yap/Taz-driven cancer.


Assuntos
Carcinogênese/genética , Quinases Ciclina-Dependentes/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/enzimologia , Drosophila melanogaster/metabolismo , Proteínas Nucleares/metabolismo , Transativadores/metabolismo , Animais , Antineoplásicos/farmacologia , Carcinogênese/efeitos dos fármacos , Linhagem Celular , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Quinases Ciclina-Dependentes/genética , Drosophila melanogaster/genética , Ativação Enzimática , Regulação Neoplásica da Expressão Gênica/genética , Técnicas de Silenciamento de Genes , Humanos , Neoplasias Hepáticas/enzimologia , Neoplasias Hepáticas/fisiopatologia , Camundongos , Tamanho do Órgão/genética , Fenilenodiaminas/farmacologia , Proteólise , Pirimidinas/farmacologia
6.
Ecotoxicol Environ Saf ; 188: 109875, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31706244

RESUMO

Previous works showed that chronic exposure to Aroclor 1254 disrupted glucose homeostasis and induced insulin resistance in male mice. To further observe the different effects of Aroclor 1254 exposure on the pancreatic α-cells and ß-cells, male mice were exposed to Aroclor 1254 (0, 0.5, 5, 50, 500 µg/kg) for 60 days, the pancreas was performed a histological examination. The results showed that the percentage of apoptosis cell (indicated by TUNEL assay) was increased in both α-cells and ß-cells, as the Aroclor 1254 dose was increased; the proliferation (indicated by PCNA expression) rate of ß-cells was elevated while that of α-cells was not affected, resulting in an increased ß-cell mass and a decreased α-cell mass in a dose-depend manner. The number of Pdx-1 positive ß-cells was significantly increased whereas that of Arx positive α-cells was markedly decreased, indicating an enhanced ß-cell neogenesis and a weakened α-cell neogenesis. The drastically reduction of serum testosterone levels in all the treatments suggested an anti-androgenic potency of Aroclor 1254. The up-regulation of estrogen receptors (ERα and ERß) and androgen receptor in ß-cells might be responsible for the increased ß-cell mass and neogenesis.


Assuntos
Antitireóideos/toxicidade , Células Secretoras de Glucagon/efeitos dos fármacos , Células Secretoras de Insulina/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Secretoras de Glucagon/metabolismo , Células Secretoras de Glucagon/patologia , Proteínas de Homeodomínio/metabolismo , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/patologia , Masculino , Camundongos , Receptores Androgênicos/metabolismo , Receptores Estrogênicos/metabolismo , Testosterona/sangue , Transativadores/metabolismo , Fatores de Transcrição/metabolismo
7.
Anticancer Res ; 39(12): 6547-6553, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31810920

RESUMO

AIM: To evaluate the frequency of loss of mediator of DNA damage checkpoint protein 1 (MDC1) protein expression in endometrial cancer (EC) and to determine whether loss of MDC1 is associated with certain clinicopathological parameters. MATERIALS AND METHODS: MDC1 expression was examined in 426 samples of EC. The nuclear immunoreactivity of the protein was defined as: negative, weak, moderate and strong. RESULTS: Loss of MDC1 expression (defined as negative nuclear staining) was found in 8.9% (38/426) of ECs and was significantly associated with the loss of MRE11 homolog, double-strand break repair nuclease, RAD50 double-strand break repair protein and nibrin complex components. In addition, loss of expression of MDC1 showed a significant correlation with any mismatch repair deficiency, with endometrioid histological subtype and low tumour grading. CONCLUSION: Based on these findings, we suggest that MDC1 loss frequently occurs in ECs with microsatellite instability. Due to deficient homologous recombination DNA repair, MDC1-negative ECs might show an increased sensitivity to poly(ADP-ribose) polymerase-inhibitory therapy.


Assuntos
Proteínas de Ciclo Celular/deficiência , Enzimas Reparadoras do DNA/deficiência , Proteínas de Ligação a DNA/deficiência , Neoplasias do Endométrio/metabolismo , Proteína Homóloga a MRE11/deficiência , Proteínas Nucleares/deficiência , Proteínas Nucleares/metabolismo , Transativadores/metabolismo , Reparo de Erro de Pareamento de DNA , Neoplasias do Endométrio/patologia , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Instabilidade de Microssatélites , Estadiamento de Neoplasias , Análise de Sobrevida , Análise Serial de Tecidos
8.
Zhonghua Zhong Liu Za Zhi ; 41(12): 918-922, 2019 Dec 23.
Artigo em Chinês | MEDLINE | ID: mdl-31874549

RESUMO

Objective: To investigate the expression level of antisense transcript of pseudogene, general transcription factor Ⅱi psedugen23 (GTF2IP23), in breast cancer and its effect on the host gene general transcription factor Ⅱi (GTF2I). Methods: The expressions of GTF2IP23 and GTF2I were detected in 40 cases of invasive breast cancer tumors and their counterparts by using quantitative real-time polymerase chain reaction (qRT-PCR). The effects of GTF2IP23 on the expression of GTF2I gene and cell proliferation and migration were analyzed by overexpression of GTF2IP23 in breast cancer cells. Results: The expression of GTF2IP23 mRNA in breast cancer tissues was significantly higher than that in adjacent tissues (P<0.001), while the expression of GTF2I mRNA was significantly lower than that in adjacent tissues (P=0.007). The expression of GTF2IP23 was negatively correlated with GTF2I (r=-0.335, P=0.025). The expression of GTF2IP23 in breast cancer cells was significantly higher than in normal breast cells (P<0.01), while GTF2I expression in breast cancer cells was significantly lower than that in normal breast cells (P<0.01). Overexpression of GTF2IP23 in ZR-75-30 cells significantly reduced the expression of GTF2I (P=0.034) and enhanced cell proliferation (P=0.017) and migration (P=0.026) capacity. Conclusions: GTF2IP23 is distinctly upregulated in breast cancer, it inhibits the expression of real gene GTF2I and promotes the proliferation of breast cancer cells.


Assuntos
Neoplasias da Mama/sangue , Proteínas Musculares/metabolismo , Proteínas Nucleares/metabolismo , Transativadores/metabolismo , Fatores de Transcrição TFII/genética , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Proteínas Musculares/genética , Proteínas Nucleares/genética , Reação em Cadeia da Polimerase em Tempo Real , Transativadores/genética , Fatores de Transcrição TFII/metabolismo
9.
Genes Dev ; 33(23-24): 1751-1774, 2019 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-31753913

RESUMO

Bromodomain proteins (BRD) are key chromatin regulators of genome function and stability as well as therapeutic targets in cancer. Here, we systematically delineate the contribution of human BRD proteins for genome stability and DNA double-strand break (DSB) repair using several cell-based assays and proteomic interaction network analysis. Applying these approaches, we identify 24 of the 42 BRD proteins as promoters of DNA repair and/or genome integrity. We identified a BRD-reader function of PCAF that bound TIP60-mediated histone acetylations at DSBs to recruit a DUB complex to deubiquitylate histone H2BK120, to allowing direct acetylation by PCAF, and repair of DSBs by homologous recombination. We also discovered the bromo-and-extra-terminal (BET) BRD proteins, BRD2 and BRD4, as negative regulators of transcription-associated RNA-DNA hybrids (R-loops) as inhibition of BRD2 or BRD4 increased R-loop formation, which generated DSBs. These breaks were reliant on topoisomerase II, and BRD2 directly bound and activated topoisomerase I, a known restrainer of R-loops. Thus, comprehensive interactome and functional profiling of BRD proteins revealed new homologous recombination and genome stability pathways, providing a framework to understand genome maintenance by BRD proteins and the effects of their pharmacological inhibition.


Assuntos
Instabilidade Genômica , Reparo de DNA por Recombinação/genética , Fatores de Transcrição/genética , Acetilação , Linhagem Celular , Quebras de DNA de Cadeia Dupla , DNA Topoisomerases Tipo I/metabolismo , DNA Topoisomerases Tipo II/metabolismo , Células HEK293 , Células HeLa , Humanos , Transativadores/metabolismo , Fatores de Transcrição/análise , Ubiquitinação , Fatores de Transcrição de p300-CBP/genética , Fatores de Transcrição de p300-CBP/metabolismo
11.
PLoS Genet ; 15(10): e1008362, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31658256

RESUMO

Many bacteria use population density to control gene expression via quorum sensing. In Vibrio cholerae, quorum sensing coordinates virulence, biofilm formation, and DNA uptake by natural competence. The transcription factors AphA and HapR, expressed at low and high cell density respectively, play a key role. In particular, AphA triggers the entire virulence cascade upon host colonisation. In this work we have mapped genome-wide DNA binding by AphA. We show that AphA is versatile, exhibiting distinct modes of DNA binding and promoter regulation. Unexpectedly, whilst HapR is known to induce natural competence, we demonstrate that AphA also intervenes. Most notably, AphA is a direct repressor of tfoX, the master activator of competence. Hence, production of AphA markedly suppressed DNA uptake; an effect largely circumvented by ectopic expression of tfoX. Our observations suggest dual regulation of competence. At low cell density AphA is a master repressor whilst HapR activates the process at high cell density. Thus, we provide deep mechanistic insight into the role of AphA and highlight how V. cholerae utilises this regulator for diverse purposes.


Assuntos
Cólera/genética , Proteínas de Ligação a DNA/genética , Transativadores/genética , Vibrio cholerae/genética , Biofilmes/crescimento & desenvolvimento , Cólera/microbiologia , Regulação Bacteriana da Expressão Gênica/genética , Interações Hospedeiro-Patógeno/genética , Humanos , Regiões Promotoras Genéticas/genética , Percepção de Quorum/genética , Fatores de Transcrição/genética , Vibrio cholerae/patogenicidade
12.
Arkh Patol ; 81(5): 11-21, 2019.
Artigo em Russo | MEDLINE | ID: mdl-31626200

RESUMO

An important role in the differentiation of tissues in different organs is played by transforming factors (TFs); pancreatic and duodenal homebox 1 (PDX-1) is one of the earliest factors for pancreatic cells. Many malignant tumors, including neuroendocrine tumors (NETs), are similar in structure, and therefore the actual problem of oncomorphology is to search for narrow-specific markers and TFs. AIM: to comparatively analyze and assess the value of the expression of the TF PDX-1 in NETs and non-NETs of different localization and histogenetic origin. MATERIAL AND METHODS: Anti-PDX-1 antibodies were used to study 528 tumors divided into 3 groups: Group 1 included 394 NETs, among them there were those of the pancreas (n=173), stomach (n=46), bowel (n=65), lung (n=40), thymus (n=8), kidney (n=6), Merkel's cell carcinomas (n=14), NETs of the breast (n=3), larynx (n=2), trachea (n=2), bladder (n=1), and metastatic NETs (n=34) of unknown primary site; Group 2 consisted of 16 tumors, of them there were paragangliomas (n=6), medullary thyroid cancers (MTC) (n=6) and adrenal pheochromocytomas (APCC) (n=4); Group 3 comprised 118 non-NETs, among them there were tumors of the pancreas (n=54), stomach (n=26), bowel (n=17), lung (n=11), breast (n=3), kidney (n=4), adrenal glands (n=2), and bladder (n=1). RESULTS: PDX-1 was positive in 75.1% (130/173) of pancreatic NETs, all insulinomas (50/50), gastrinomas (11/11), somatostatinomas (3/3), ACTH-producing tumors (2/2); PDX-1 was positive in the non-functioning pancreatic NETs, all PPomas (19/19), 76.1% (35/46) of NETs without the hormone detected, 50% (2/4) of calcitoninomas, and 21.1% (8/38) of silent glucagonomas. PDX-1 was positive in 32.4% (11/34) of carcinoids and 50% (6/12) of neuroendocrine carcinomas, all duodenal NETs (18/18), 90% (9/10) of rectal carcinoids and 30.8% (4/13) colonic carcinoids, 37.5% (3/8) of thymic/mediastinal carcinoids, 66.7% (4/6) of kidney carcinoids, and 37.5% (9/24) of metastatic NETs of unknown primary site. PDX-1 was negative in all carcinoids of the colon and sigmoid (0/5), ileum and jejunum (0/24), lung (0/40), trachea (0/2), larynx (0/2), Merkel's cell carcinoma (0/14), breast (0/3), bladder (0/1), as well as MTC (0/6), APCC (0/4), and paragangliomas (0/6). PDX-1-positive non-NETs included 81.8% (18/22) of adenocarcinomas (AC) and all serous cystic, mucinous cystic, intraductal and acinar cell tumors of the pancreas (4/4, 3/3, 2/2, and 3/3), 57.1% of AC (8/14) and 83.3% of signet ring cell carcinomas of the stomach (10/12), 56.2% AC of the bowel (9/17), bladder cancer (1/1). PDX-1 was negative in all anaplastic cancers (0/2) and solid pseudopapillary tumors of the pancreas (0/20), cancers of the lung (0/11), kidney (0/4), breast (0/3), and adrenal glands (0/2). CONCLUSION: The expression of PDX-1 is very specific for most digestive tract NETs and non-NETs. Pancreatic ductal and acinar cell tumors and gastric signet ring cell carcinomas are most commonly PDX-1-positive. Most tumors that do not originate from the digestive tract have a PDX-1 negative immunophenotype.


Assuntos
Proteínas de Homeodomínio/metabolismo , Tumores Neuroendócrinos/diagnóstico , Neoplasias Pancreáticas/diagnóstico , Transativadores/metabolismo , Biomarcadores Tumorais/metabolismo , Humanos
13.
Zhonghua Gan Zang Bing Za Zhi ; 27(9): 693-697, 2019 Sep 20.
Artigo em Chinês | MEDLINE | ID: mdl-31594094

RESUMO

Objective: To investigate the effect and mechanism of XTP4 gene in apoptotic hepatoblastoma HepG2 cell line. Methods: HepG2 cells were transiently transfected with small interfering RNA of XTP4 genes, plasmid pcDNA3.1/myc-His(-) A-XTP4, and hepatitis B virus X protein transactivated x gene 4 (HBX protein trans-activate gene4, XTP4) and their respective negative controls. After 48h, the overexpression and interference expression condition of XTP4 in HepG2 cells were detected by Western blot. HepG2 cells apoptosis was detected by flow cytometry. The expression levels of apoptosis-related proteins P53, Bcl-2, Bax and Caspase-3 in HepG2 cells were detected by Western blot, and Bcl-2/Bax ratio was calculated. The chemiluminescence assay was used to detect activity of caspase-3 in HepG2 cells. The measured data were presented as (x ± s), and independent sample t-test was used for comparison between the two groups. Results: HepG2 cells had successfully achieved the overexpression and interference expression of XTP4 protein. Compared with the control group, the overexpression of XTP4 in HepG2 cells had significantly decreased the number of apoptotic cells (P < 0.05), and increased Bcl-2/Bax (P < 0.05) ratio, but decreased the expression of P53 protein (P < 0.05). The protein expression of Caspase-3 and activity of caspase-3 was decreased (P < 0.05). However, interference with XTP4 expression in HepG2 cells had significantly increased the number of apoptotic cells (P < 0.05) and decreased Bcl-2/Bax (P < 0.05) ratio, but increased the expression of P53 protein (P < 0.05). The protein expression of Caspase-3 and activity of caspase-3 was increased (P<0.05). Conclusion: In HepG2 apoptosis XTP4 has inhibitory effect, and its effect on inhibiting HepG2 apoptosis may be achieved by regulating the Bcl-2/Bax ratio, and the P53 protein may be involved.


Assuntos
Apoptose , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Transativadores/metabolismo , Caspase 3/metabolismo , Células Hep G2 , Humanos , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Transfecção , Proteína Supressora de Tumor p53/metabolismo , Proteína X Associada a bcl-2/metabolismo
14.
Cell Prolif ; 52(6): e12703, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31621133

RESUMO

OBJECTIVES: Interleukin-34 (IL-34) is associated with hepatitis B virus (HBV) infection and hepatocellular carcinoma (HCC). However, the role and associated mechanisms of IL-34 in HBV-related HCC remain unclear. In this study, the expression, biological function and associated mechanisms of IL-34 in HBV-related HCC cells were investigated. METHODS: IL-34 expression induced by HBV and HBV X (HBX) gene was measured in hepatoma cells. The role of CCAAT/enhancer-binding protein α (CEBP/α) in HBX-induced IL-34 expression was examined. The signal pathways involved in the expression of CEBP/α and IL-34 induced by HBX were assessed. The role of IL-34 in the proliferation and migration of HCC cells, and related mechanisms were explored. RESULTS: Dependent on HBX, HBV increased IL-34 expression in hepatoma cells, and HBX upregulated and interacted with CEBP/α to enhance the activity of IL-34 promoters. CEBP/α mediated by HBX was associated with the activation of PI3-K and NF-κB pathways to promote IL-34 expression. Via CSF1-R and CD138, IL-34 promoted the proliferation and migration of hepatoma cells, and contributed to the activation of ERK and STAT3 pathways and the upregulation of Bcl-xl and c-Myc mediated by HBX. CONCLUSION: We demonstrate that IL-34 contributes to HBX-mediated functional abnormality of HCC cells and provides a novel insight into the molecular mechanism of carcinogenesis mediated by HBX.


Assuntos
Proteína alfa Estimuladora de Ligação a CCAAT/metabolismo , Movimento Celular/fisiologia , Proliferação de Células/fisiologia , Interleucinas/metabolismo , Transativadores/metabolismo , Carcinoma Hepatocelular/genética , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Hepatite B , Humanos , Neoplasias Hepáticas/genética
15.
Mol Immunol ; 116: 18-28, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31574452

RESUMO

Emerging evidence indicates that the lncRNAs/microRNA/mRNA axis plays important roles in a variety of diseases. This study was aimed to investigate the potential roles and underlying molecular mechanisms of lncRNA H19 and H19-derived miR-675 in regulating hepatitis B virus (HBV)-associated liver injury. mRNA and miR-675 levels were determined by quantitative real-time PCR (qRT-PCR), protein levels were determined by western blot, cell viability was measured by the MTT assay, cell apoptosis was measured by flow cytometry, inflammatory cytokine production was determined by ELISA, oxidative stress and energy metabolism were assessed by commercial kits, and the target relationship between PPARα and miR-675 was confirmed by the dual-luciferase reporter assay. The results showed that the expression of lncRNA H19 and miR-675 was up-regulated in patients with chronic hepatitis B (n = 20). Inhibition of lncRNA H19 or miR-675 in L02 cells increased cell viability, suppressed hepatitis B X protein (HBx)-induced cell apoptosis, inflammatory cytokine production, and oxidative stress, and remodelled energy metabolism. Furthermore, PPARα was found to be a target gene of miR-675. The expression of PPARα was down-regulated in patients with chronic hepatitis B, and there was a negative correlation between the expression of lncRNA H19 and PPARα, or between miR-675 and PPARα. Moreover, by knocking down the expression of PPARα, the actions (apoptosis, inflammatory factors, oxidative stress, and energy metabolism) of lncRNA H19 or miR-675 inhibition in HBx-induced L02 cells were at least partially reversed. In addition, HBx-induced elevated levels of p-AktSer473, p-AktThr308 and p-mTORSer2448 were down-regulated by lncRNA H19 or miR-675 inhibition. Furthermore, PPARα knockdown partly reversed the down-regulated effects of H19 or miR-675 inhibition. Taken together, these data indicate that the lncRNA H19/miR-675/PPARα axis regulates liver cell injury and energy metabolism remodelling induced by HBx, which may be related to the modulation of Akt/mTOR signalling.


Assuntos
Metabolismo Energético/genética , MicroRNAs/genética , PPAR alfa/genética , Proteínas Proto-Oncogênicas c-akt/genética , RNA Longo não Codificante/genética , Serina-Treonina Quinases TOR/genética , Transativadores/genética , Apoptose/genética , Linhagem Celular , Proliferação de Células/genética , Sobrevivência Celular/genética , Regulação para Baixo/genética , Células HEK293 , Hepatite B/genética , Vírus da Hepatite B/genética , Humanos , Fígado/metabolismo , Fígado/virologia , Transdução de Sinais/genética
16.
Nat Commun ; 10(1): 4181, 2019 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-31519907

RESUMO

The stability and quality of metazoan mRNAs are under microRNA (miRNA)-mediated and nonsense-mediated control. Although UPF1, a core mediator of nonsense-mediated mRNA decay (NMD), mediates the decay of target mRNA in a 3'UTR-length-dependent manner, the detailed mechanism remains unclear. Here, we suggest that 3'UTR-length-dependent mRNA decay is not mediated by nonsense mRNAs but rather by miRNAs that downregulate target mRNAs via Ago-associated UPF1/SMG7. Global analyses of mRNAs in response to UPF1 RNA interference in miRNA-deficient cells reveal that 3'UTR-length-dependent mRNA decay by UPF1 requires canonical miRNA targeting. The destabilization of miRNA targets is accomplished by the combination of Ago2 and UPF1/SMG7, which may recruit the CCR4-NOT deadenylase complex. Indeed, loss of the SMG7-deadenylase complex interaction increases the levels of transcripts regulated by UPF1-SMG7. This UPF1/SMG7-dependent miRNA-mediated mRNA decay pathway may enable miRNA targeting to become more predictable and expand the miRNA-mRNA regulatory network.


Assuntos
Proteínas de Transporte/metabolismo , Biologia Computacional/métodos , MicroRNAs/metabolismo , RNA Helicases/metabolismo , Estabilidade de RNA/fisiologia , Transativadores/metabolismo , Regiões 3' não Traduzidas/genética , Animais , Western Blotting , Proteínas de Transporte/genética , Regulação da Expressão Gênica/genética , Regulação da Expressão Gênica/fisiologia , Células HeLa , Humanos , Camundongos , MicroRNAs/genética , RNA Helicases/genética , Interferência de RNA/fisiologia , Estabilidade de RNA/genética , Transativadores/genética
17.
Life Sci ; 235: 116858, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31505195

RESUMO

AIMS: The current study was conducted to investigate the potential protective effects of hesperidin and its possible mechanisms of action on pancreatic ß-cells in diabetes. MAIN METHODS: Male Sprague Dawley rats were made diabetic using 65 mg/kg intraperitoneal injection of streptozotocin, and then administered daily with 100 mg/kg of hesperidin over 4 weeks. On conclusion of the experiment, blood and pancreatic tissue were collected to determine the function of ß-cells, apoptosis, oxidative stress, ER stress, and inflammation. KEY FINDINGS: Treatment of diabetic rats with hesperidin, significantly decreased fasting blood glucose and food intake, along with increased body weight, serum and pancreatic insulin levels, and pancreatic-duodenal homeobox-1 (PDX-1) protein expression. The beneficial roles of hesperidin on diabetic pancreatic ß-cells exhibited an increment in antioxidant SOD and GPx activities, and a decrement in nitrotyrosine as well as malondialdehyde (MDA) levels. Additionally, the elevated concentration of TNF-α and expressions of ER stress maker GRP78 and CHOP proteins in the pancreas of diabetic rats were significantly diminished by hesperidin treatment. Furthermore, hesperidin effectively modulated expressions of apoptosis-regulatory proteins in diabetic rat pancreas, as revealed by upregulating anti-apoptotic Bcl-xL; with a concomitant downregulating pro-apoptotic Bax, cleaved caspase-3, and inhibiting the activation of DNA repair protein poly (ADP-ribose) polymerase (PARP). SIGNIFICANCE: Collectively, these findings suggest that hesperidin may have the potential to protect pancreatic ß-cells and improve their function by suppressing oxidative and ER stress, along with activating its antioxidant, anti-inflammatory, and anti-apoptotic effects.


Assuntos
Apoptose/efeitos dos fármacos , Diabetes Mellitus Experimental/prevenção & controle , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Hesperidina/farmacologia , Células Secretoras de Insulina/metabolismo , Animais , Proteínas Reguladoras de Apoptose/metabolismo , Glicemia/efeitos dos fármacos , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/metabolismo , Ingestão de Alimentos/efeitos dos fármacos , Glutationa Peroxidase/metabolismo , Proteínas de Choque Térmico/metabolismo , Proteínas de Homeodomínio/biossíntese , Inflamação , Insulina/sangue , Insulina/metabolismo , Masculino , Malondialdeído/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Pâncreas/metabolismo , Substâncias Protetoras/farmacologia , Ratos , Superóxido Dismutase/metabolismo , Transativadores/biossíntese , Fator de Transcrição CHOP/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Tirosina/análogos & derivados , Tirosina/metabolismo
18.
Zhongguo Dang Dai Er Ke Za Zhi ; 21(9): 930-935, 2019 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-31506156

RESUMO

OBJECTIVE: To investigate the effect and molecular mechanism of interferon-α (INF-α) on the apoptosis of the mouse podocyte cell line MPC5 induced by hepatitis B virus X (HBx) protein. METHODS: MPC5 cells were transfected with the pEX plasmid carrying the HBx gene. RT-PCR was used to measure the mRNA expression of HBx at different time points. MPC5 cells were divided into 4 groups: control group (MPC5 cells cultured under normal conditions), INF-α group (MPC5 cells cultured with INF-α), HBx group (MPC5 cells induced by HBx), and HBx+INF-α group (MPC5 cells induced by HBx and cultured with INF-α). After 48 hours of intervention under different experimental conditions, flow cytometry was used to measure the apoptosis of MPC5 cells, and quantitative real-time PCR and Western blot were used to measure the mRNA and protein expression of slit diaphragm-related proteins (nephrin, CD2AP, and synaptopodin) and the cytoskeleton-related protein transient receptor potential cation channel 6 (TRPC6). RESULTS: MPC5 cells transfected by pEX-HBx had the highest expression of HBx mRNA at 48 hours after transfection (P<0.05). Compared with the control, INF-α and HBx+INF-α groups, the HBx group had a significant increase in the apoptosis rate of MPC5 cells (P<0.05). Compared with the control and INF-α groups, the HBx group had significant reductions in the mRNA and protein expression of nephrin, synaptopodin, and CD2AP and significant increases in the mRNA and protein expression of TRPC6 (P<0.05). Compared with the HBx group, the HBx+INF-α group had significant increases in the mRNA and protein expression of nephrin, synaptopodin, and CD2AP and significant reductions in the mRNA and protein expression of TRPC6 (P<0.05). CONCLUSIONS: INF-α can inhibit the apoptosis of podocytes induced by HBx, possibly through improving the abnormal expression of slit diaphragm-related proteins (CD2AP, nephrin, and synaptopodin) and cytoskeleton-related protein (TRPC6) induced by HBx.


Assuntos
Podócitos , Animais , Apoptose , Vírus da Hepatite B , Interferon-alfa , Camundongos , Transativadores
19.
Nat Commun ; 10(1): 4113, 2019 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-31511517

RESUMO

Intra-organ communication guides morphogenetic processes that are essential for an organ to carry out complex physiological functions. In the heart, the growth of the myocardium is tightly coupled to that of the endocardium, a specialized endothelial tissue that lines its interior. Several molecular pathways have been implicated in the communication between these tissues including secreted factors, components of the extracellular matrix, or proteins involved in cell-cell communication. Yet, it is unknown how the growth of the endocardium is coordinated with that of the myocardium. Here, we show that an increased expansion of the myocardial atrial chamber volume generates higher junctional forces within endocardial cells. This leads to biomechanical signaling involving VE-cadherin, triggering nuclear localization of the Hippo pathway transcriptional regulator Yap1 and endocardial proliferation. Our work suggests that the growth of the endocardium results from myocardial chamber volume expansion and ends when the tension on the tissue is relaxed.


Assuntos
Endocárdio/crescimento & desenvolvimento , Miocárdio/metabolismo , Transdução de Sinais , Peixe-Zebra/embriologia , Animais , Antígenos CD/metabolismo , Fenômenos Biomecânicos , Caderinas/metabolismo , Núcleo Celular/metabolismo , Proliferação de Células , Tamanho Celular , Proteínas do Citoesqueleto/metabolismo , Endocárdio/citologia , Átrios do Coração/citologia , Átrios do Coração/metabolismo , Proteína Homeobox Nkx-2.5/metabolismo , Junções Intercelulares/metabolismo , Modelos Biológicos , Mutação/genética , Transativadores/metabolismo , Proteínas Wnt/metabolismo , Proteínas de Peixe-Zebra/metabolismo
20.
Nat Commun ; 10(1): 4128, 2019 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-31511524

RESUMO

Pediatric malignancies including Ewing sarcoma (EwS) feature a paucity of somatic alterations except for pathognomonic driver-mutations that cannot explain overt variations in clinical outcome. Here, we demonstrate in EwS how cooperation of dominant oncogenes and regulatory germline variants determine tumor growth, patient survival and drug response. Binding of the oncogenic EWSR1-FLI1 fusion transcription factor to a polymorphic enhancer-like DNA element controls expression of the transcription factor MYBL2 mediating these phenotypes. Whole-genome and RNA sequencing reveals that variability at this locus is inherited via the germline and is associated with variable inter-tumoral MYBL2 expression. High MYBL2 levels sensitize EwS cells for inhibition of its upstream activating kinase CDK2 in vitro and in vivo, suggesting MYBL2 as a putative biomarker for anti-CDK2-therapy. Collectively, we establish cooperation of somatic mutations and regulatory germline variants as a major determinant of tumor progression and highlight the importance of integrating the regulatory genome in precision medicine.


Assuntos
Mutação em Linhagem Germinativa/genética , Neoplasias/genética , Neoplasias/terapia , Animais , Proteínas de Ciclo Celular , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular , Quinase 2 Dependente de Ciclina/antagonistas & inibidores , Quinase 2 Dependente de Ciclina/metabolismo , Regulação Neoplásica da Expressão Gênica , Células HEK293 , Humanos , Camundongos , Repetições de Microssatélites/genética , Proteínas de Neoplasias/metabolismo , Proteínas de Fusão Oncogênica/metabolismo , Fenótipo , Polimorfismo Genético , Transativadores , Resultado do Tratamento , Regulação para Cima/genética
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