Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 3.916
Filter
1.
Cell Death Dis ; 12(2): 206, 2021 02 24.
Article in English | MEDLINE | ID: mdl-33627630

ABSTRACT

Steroid 5α-reductase type I (SRD5A1) is a validated oncogene in many sex hormone-related cancers, but its role in multiple myeloma (MM) remains unknown. Based on gene expression profiling (GEP) of sequential MM samples during the disease course, we found that the aberrant expression of SRD5A1 was correlated with progression and poor prognosis in MM patients. In this study, the oncogenic roles of SRD5A1 were validated in human MM cell lines (ARP1 and H929) and the xenograft MM model as well as the 5TMM mouse model. MTT and flow cytometry were used to assess MM cell proliferation, cell cycle, and apoptosis post inducible knockdown SRD5A1 by lentivirus-mediated short-hairpin RNA (shRNA). Transcriptomic sequencing, immunofluorescence, and western blot were used to investigate the effects of SRD5A1 suppression on cell apoptosis and autophagy. Mechanistically, SRD5A1 downregulation simultaneously regulated both the Bcl-2 family protein-mediated apoptosis and the autophagic process via PI3K/Akt/mTOR signaling pathway in MM cells. Meanwhile, the autophagy inhibitor (3-methyladenine) and SRD5A1 inhibitor (Dutasteride) were utilized to evaluate their anti-myeloma effect. Thus, our results demonstrated that SRD5A1 downregulation simultaneously regulated both the apoptosis and the autophagic process in MM cells. The dual autophagy-apoptosis regulatory SRD5A1 may serve as a biomarker and potential target for MM progression and prognosis.


Subject(s)
3-Oxo-5-alpha-Steroid 4-Dehydrogenase/metabolism , Apoptosis , Autophagy , Membrane Proteins/metabolism , Multiple Myeloma/enzymology , Phosphatidylinositol 3-Kinase/metabolism , Proto-Oncogene Proteins c-akt/metabolism , TOR Serine-Threonine Kinases/metabolism , 3-Oxo-5-alpha-Steroid 4-Dehydrogenase/genetics , 5-alpha Reductase Inhibitors/pharmacology , Adenine/analogs & derivatives , Adenine/pharmacology , Animals , Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Autophagy/drug effects , Cell Line, Tumor , Cell Proliferation , Dutasteride/pharmacology , Enzyme Repression , Female , Gene Expression Regulation, Neoplastic , Humans , Male , Membrane Proteins/antagonists & inhibitors , Membrane Proteins/genetics , Mice, Inbred C57BL , Mice, Inbred NOD , Multiple Myeloma/drug therapy , Multiple Myeloma/genetics , Multiple Myeloma/pathology , Signal Transduction
2.
J Cell Physiol ; 234(12): 22635-22647, 2019 12.
Article in English | MEDLINE | ID: mdl-31102300

ABSTRACT

Calcium-activated nucleotidase 1 (CANT1, belongs to the apyrase family, is widely expressed in various organs. However, the biological function of CANT1 remains poorly explored. In this study, we aimed to investigate the expression profile and functions of CANT1 in clear cell renal cell carcinoma (ccRCC). Our data show that the protein level of CANT1 was significantly higher in tumor tissues than in adjacent normal tissues. CANT1 silencing suppressed cell proliferation, migration, and invasion obviously in 769-P and 786-O cells, arrested cell cycle in S phase and promoted apoptosis in 769-P cells. In conclusion, the present study shows the different expression mode of CANT1 in human ccRCC tumor tissue and adjacent normal tissue, denotes the function of CANT1 in ccRCC cells and provides potential molecular mechanisms and pathways of CANT1 antitumor function in ccRCC.


Subject(s)
Carcinoma, Renal Cell/enzymology , Cell Proliferation , Kidney Neoplasms/enzymology , Nucleotidases/metabolism , RNA Interference , Apoptosis , Carcinoma, Renal Cell/genetics , Carcinoma, Renal Cell/pathology , Cell Line, Tumor , Cell Movement , Enzyme Repression , Gene Expression Regulation, Neoplastic , Humans , Kidney Neoplasms/genetics , Kidney Neoplasms/pathology , Neoplasm Invasiveness , Nucleotidases/genetics , S Phase Cell Cycle Checkpoints , Signal Transduction
3.
Cancer Lett ; 452: 23-30, 2019 06 28.
Article in English | MEDLINE | ID: mdl-30910586

ABSTRACT

The effect of proton pump inhibitors (PPIs) on cancer risk has received much attention recently. Over the last two decades, we and others have disclosed that PPIs exerted anticancer effects. Telomerase reverse transcriptase (TERT) is essential for telomere maintenance. The activation of TERT is considered a crucial step in tumorigenesis; therefore, it is a potential therapeutic target against cancer. However, whether PPIs suppress gastric cancer by targeting TERT remains elusive. Our study demonstrated that PPZ treatment repressed TERT expression in gastric cancer cells via regulating TERT promoter activity by disturbing the interaction of STAT3 with the TERT gene. Additionally, PPZ led to chromatin remodeling within the TERT gene and resulted in a more compacted spatial conformation that is known to be associated with gene silencing. PPZ downregulated the TERT gene to inactivate the Wnt/ß-catenin signaling pathway and reverse the EMT process, finally inhibiting gastric cancer metastasis both in vitro and in vivo. Our results suggest that PPIs may be potentially developed as effective as well as relatively safe and specific anticancer agents.


Subject(s)
Antineoplastic Agents/pharmacology , Cell Movement/drug effects , Lung Neoplasms/prevention & control , Pantoprazole/pharmacology , Proton Pump Inhibitors/pharmacology , Stomach Neoplasms/drug therapy , Telomerase/metabolism , Animals , Cell Line, Tumor , Chromatin Assembly and Disassembly/drug effects , Enzyme Repression , Gene Expression Regulation, Neoplastic , Humans , Lung Neoplasms/enzymology , Lung Neoplasms/genetics , Lung Neoplasms/secondary , Male , Mice, Inbred BALB C , STAT3 Transcription Factor/metabolism , Stomach Neoplasms/enzymology , Stomach Neoplasms/genetics , Stomach Neoplasms/pathology , Telomerase/genetics , Wnt Signaling Pathway , Xenograft Model Antitumor Assays
4.
J Immunol Res ; 2018: 7313515, 2018.
Article in English | MEDLINE | ID: mdl-30402512

ABSTRACT

Aberrant histone acetylation and deacetylation are increasingly thought to play important roles in the pathogenesis of rheumatoid arthritis (RA). However, limited data from studies about the activity of histone deacetylases (HDACs) and histone acetyltransferase (HAT) in RA are controversial. Those conflicting results may be caused by sample size, medication, and age- and sex-matched controls. The aim of this study is to investigate the expression and activity of class I HDACs (1-3.8) and their effects on histone acetylation in peripheral blood mononuclear cells (PBMCs) from RA patients. The expression of class I HDACs in PBMCs from RA patients was decreased in both mRNA and protein levels in comparison with HCs. The nuclear HAT activities were dramatically increased. Further, we found HDAC3 activity to be the most significantly reduced in overall reduction of HDACs in the RA group. The extent of total histone H3, but not H4, acetylation in PBMCs from RA patients was increased compared to that in healthy controls (HCs) (p < 0.01). In RA PBMCs, the activity and expression of class I HDACs are decreased, which is accompanied with enhanced HAT activity. An altered balance between HDAC and HAT activity was found in RA PBMCs.


Subject(s)
Arthritis, Rheumatoid/immunology , Histone Acetyltransferases/metabolism , Histone Deacetylases/metabolism , Leukocytes, Mononuclear/physiology , RNA, Messenger/genetics , Acetylation , Adult , Aged , Enzyme Repression , Female , Histone Acetyltransferases/genetics , Histone Deacetylases/genetics , Histones/metabolism , Humans , Male , Middle Aged , Young Adult
5.
Nat Cell Biol ; 20(7): 811-822, 2018 07.
Article in English | MEDLINE | ID: mdl-29941929

ABSTRACT

G protein αs (GNAS) mediates receptor-stimulated cAMP signalling, which integrates diverse environmental cues with intracellular responses. GNAS is mutationally activated in multiple tumour types, although its oncogenic mechanisms remain elusive. We explored this question in pancreatic tumourigenesis where concurrent GNAS and KRAS mutations characterize pancreatic ductal adenocarcinomas (PDAs) arising from intraductal papillary mucinous neoplasms (IPMNs). By developing genetically engineered mouse models, we show that GnasR201C cooperates with KrasG12D to promote initiation of IPMN, which progress to invasive PDA following Tp53 loss. Mutant Gnas remains critical for tumour maintenance in vivo. This is driven by protein-kinase-A-mediated suppression of salt-inducible kinases (Sik1-3), associated with induction of lipid remodelling and fatty acid oxidation. Comparison of Kras-mutant pancreatic cancer cells with and without Gnas mutations reveals striking differences in the functions of this network. Thus, we uncover Gnas-driven oncogenic mechanisms, identify Siks as potent tumour suppressors, and demonstrate unanticipated metabolic heterogeneity among Kras-mutant pancreatic neoplasms.


Subject(s)
Carcinoma, Pancreatic Ductal/enzymology , Carcinoma, Pancreatic Ductal/genetics , Cell Transformation, Neoplastic/genetics , Cell Transformation, Neoplastic/metabolism , Cellular Reprogramming/genetics , Chromogranins/genetics , Cyclic AMP-Dependent Protein Kinases/metabolism , GTP-Binding Protein alpha Subunits, Gs/genetics , Lipid Metabolism/genetics , Mutation , Pancreatic Neoplasms/enzymology , Pancreatic Neoplasms/genetics , Protein Serine-Threonine Kinases/metabolism , Animals , Carcinoma, Pancreatic Ductal/pathology , Cell Line, Tumor , Cell Transformation, Neoplastic/pathology , Chromogranins/metabolism , Cyclic AMP-Dependent Protein Kinases/genetics , Enzyme Repression , Fatty Acids/metabolism , Female , GTP-Binding Protein alpha Subunits, Gs/metabolism , Gene Expression Regulation, Neoplastic , Genes, ras , Genetic Predisposition to Disease , Humans , Male , Mice, 129 Strain , Mice, Inbred C57BL , Mice, Inbred NOD , Mice, Mutant Strains , Mice, Transgenic , Oxidation-Reduction , Pancreatic Neoplasms/pathology , Phenotype , Protein Serine-Threonine Kinases/genetics , Signal Transduction , Time Factors , Tumor Cells, Cultured , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism
6.
Article in English | MEDLINE | ID: mdl-29729480

ABSTRACT

Semicarbazide (SMC), a new marine pollutant, has anti-estrogenic effects on female Japanese flounder (Paralichthys olivaceus). However, whether SMC also affects the reproductive endocrine system of male marine organisms is currently unclear. In this study, Japanese flounder embryos were exposed to 1, 10, and 100 µg/L SMC for 130 days. Plasma testosterone (T) and 17ß-estradiol (E2) concentrations were significantly decreased in male flounders after SMC exposure. The expression of genes involved in T and E2 synthesis, including steroidogenic acute regulatory protein, cytochrome P450 11A1, 17α-hydroxylase, 17ß-hydroxysteroid dehydrogenase and cytochrome P450 19A, was down-regulated in the gonads, which may explain the decrease in plasma sex hormones levels. Moreover, SMC-mediated changes in the transcription of these steroidogenic genes were associated with reduced levels of follicle-stimulating hormone beta subunit (fshß), luteinizing hormone beta subunit (lhß), follicle-stimulating hormone receptor (fshr) and luteinizing hormone receptor (lhr) mRNA. In addition, down-regulated transcription of fshß and lhß in the SMC exposure groups was affected by reduced mRNA levels of seabream gonadotropin-releasing hormone (sbgnrh), g-protein-coupled receptor 54 (gpr54) in the kisspeptin/gpr54 system, as well as the gamma-aminobutyric acid (GABA) synthesis enzyme glutamic acid decarboxylase (gad). Overall, our results showed that environmentally relevant concentrations of SMC exerted anti-androgenic effects in male flounders via impacting HPG axis, kiss/gpr54 system and GABA synthesis, providing theoretical support for investigating reproductive toxicity of environmental pollutants that interfere with the neuroendocrine system.


Subject(s)
Embryo, Nonmammalian/drug effects , Endocrine Disruptors/toxicity , Flatfishes/metabolism , Hypothalamo-Hypophyseal System/drug effects , Semicarbazides/toxicity , Testis/drug effects , Water Pollutants, Chemical/toxicity , Androgen Antagonists/toxicity , Animals , Aquaculture , China , Embryo, Nonmammalian/metabolism , Embryonic Development/drug effects , Enzyme Repression/drug effects , Estradiol/biosynthesis , Estradiol/blood , Estradiol/chemistry , Estrogen Antagonists/toxicity , Fish Proteins/antagonists & inhibitors , Fish Proteins/genetics , Fish Proteins/metabolism , Flatfishes/blood , Flatfishes/growth & development , Gene Expression Regulation, Developmental/drug effects , Hypothalamo-Hypophyseal System/growth & development , Hypothalamo-Hypophyseal System/metabolism , Kisspeptins/antagonists & inhibitors , Kisspeptins/genetics , Kisspeptins/metabolism , Male , Random Allocation , Testis/growth & development , Testis/metabolism , Testosterone/antagonists & inhibitors , Testosterone/biosynthesis , Testosterone/blood , Toxicity Tests, Chronic
7.
Toxicol Appl Pharmacol ; 352: 77-86, 2018 08 01.
Article in English | MEDLINE | ID: mdl-29802914

ABSTRACT

It is known that inhibiting 11ß-hydroxysteroid dehydrogenase type 2 (11ß-HSD2) expression in the placenta can cause fetal over-exposure to maternal glucocorticoids and induce intrauterine growth restriction (IUGR); these effects ultimately increase the risk of adult chronic diseases. This study aimed to investigate the molecular mechanism of the prenatal ethanol exposure (PEE)-induced inhibition of placental 11ß-HSD2 expression. Pregnant Wistar rats were intragastrically administered ethanol (4 g/kg/d) from gestational days 9 to 20. The levels of maternal and fetal serum corticosterone and placental 11ß-HSD2-related gene expression were analyzed. Furthermore, we investigated the mechanism of reduced placental 11ß-HSD2 expression induced by ethanol treatment (15-60 mM) in HTR-8/SVneo cells. In vivo, PEE decreased fetal body weights and increased maternal and fetal serum corticosterone and early growth response factor 1 (EGR1) expression levels. Moreover, histone modification changes (decreased acetylation and increased di-methylation of H3K9) to the HSD11B2 promoter and lower 11ß-HSD2 expression levels were observed. In vitro, ethanol decreased cAMP/PKA signaling and 11ß-HSD2 expression and increased EGR1 expression in a concentration-dependent manner. A cAMP agonist and EGR1 siRNA reversed the ethanol-induced inhibition of 11ß-HSD2 expression. Together, PEE reduced placental 11ß-HSD2 expression, and the underlying mechanism is associated with ethanol-induced histone modification changes to the HSD11B2 promoter through the cAMP/PKA/EGR1 pathway.


Subject(s)
11-beta-Hydroxysteroid Dehydrogenase Type 2/metabolism , Alcohol Drinking/adverse effects , Cyclic AMP-Dependent Protein Kinases/metabolism , Cyclic AMP/metabolism , Early Growth Response Protein 1/metabolism , Ethanol/toxicity , Placenta/drug effects , 11-beta-Hydroxysteroid Dehydrogenase Type 2/genetics , Acetylation , Animals , Cell Line , Early Growth Response Protein 1/genetics , Enzyme Repression , Female , Gene Expression Regulation, Developmental , Gestational Age , Histones/metabolism , Humans , Methylation , Placenta/enzymology , Pregnancy , Promoter Regions, Genetic , Rats, Wistar , Signal Transduction/drug effects
8.
Mol Microbiol ; 108(3): 226-239, 2018 05.
Article in English | MEDLINE | ID: mdl-29424946

ABSTRACT

Nucleoid-associated protein H-NS represses transcription by forming extended DNA-H-NS complexes. Repression by H-NS operates mostly at the level of transcription initiation. Less is known about how DNA-H-NS complexes interfere with transcription elongation. In vitro H-NS has been shown to enhance RNA polymerase pausing and to promote Rho-dependent termination, while in vivo inhibition of Rho resulted in a decrease of the genome occupancy by H-NS. Here we show that transcription directed across H-NS binding regions relieves H-NS (and H-NS/StpA) mediated repression of promoters in these regions. Further, we observed a correlation of transcription across the H-NS-bound region and de-repression. The data suggest that the transcribing RNA polymerase is able to remodel the H-NS complex and/or dislodge H-NS from the DNA and thus relieve repression. Such an interference of transcription and H-NS mediated repression may imply that poorly transcribed AT-rich loci are prone to be repressed by H-NS, while efficiently transcribed loci escape repression.


Subject(s)
Bacterial Proteins/genetics , Bacterial Proteins/metabolism , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Bacterial Proteins/biosynthesis , Binding Sites/genetics , DNA, Bacterial/metabolism , DNA-Binding Proteins/biosynthesis , DNA-Directed RNA Polymerases/metabolism , Enzyme Repression , Escherichia coli/genetics , Escherichia coli Proteins/genetics , Gene Expression Regulation, Bacterial/genetics , Promoter Regions, Genetic/genetics , Transcription, Genetic/genetics , Transcription, Genetic/physiology
9.
J Med Food ; 21(3): 254-260, 2018 Mar.
Article in English | MEDLINE | ID: mdl-29315003

ABSTRACT

Allium hookeri has been widely cultivated and used as a vegetable and medicine in Asia, but its anti-obesity effects have not been previously reported. In this study, the effects of a leaf extract of A. hookeri on obesity were investigated by administering a high-fat diet (HFD) to mice. Male Institute of Cancer Research mice (n = 32; 5 weeks old) were randomly divided into four groups: normal-diet group, HFD group, HFD containing 200 mg/kg/day A. hookeri leaf extract (HFD-A1), and HFD containing 400 mg/kg/day A. hookeri leaf extract (HFD-A2). A. hookeri leaf extract was orally administered daily for 4 weeks. We found that the body weight gain and organ tissue weights of mice in the HFD-A1 and HFD-A2 groups were significantly lower compared with those of mice in the HFD group. Administration of A. hookeri leaf extract also significantly decreased the size of the epididymal adipose tissue (AT). Serum levels of triglyceride (TG), total cholesterol, low-density lipoprotein cholesterol, and the atherogenic index were significantly lower in the HFD-A1 and HFD-A2 groups than in the HFD group. The TG and total cholesterol levels in the hepatic, epididymal, and mesenteric ATs of the HFD-A2 group were significantly lower than the levels in the HFD group. In addition, mRNA levels of liver fatty acid synthase and lipoprotein lipase were decreased in the A. hookeri leaf extract groups compared with those of the HFD group. These results demonstrate that intake of A. hookeri leaf may have beneficial effects for suppressing obesity-related disease.


Subject(s)
Adiposity , Allium/chemistry , Anti-Obesity Agents/therapeutic use , Dietary Supplements , Obesity/prevention & control , Plant Extracts/therapeutic use , Plant Leaves/chemistry , Adipose Tissue, White/metabolism , Adipose Tissue, White/pathology , Animals , Anti-Obesity Agents/administration & dosage , Diet, High-Fat/adverse effects , Enzyme Repression , Fatty Acid Synthases/antagonists & inhibitors , Fatty Acid Synthases/genetics , Fatty Acid Synthases/metabolism , Hyperlipidemias/etiology , Hyperlipidemias/metabolism , Hyperlipidemias/pathology , Hyperlipidemias/prevention & control , Hypolipidemic Agents/administration & dosage , Hypolipidemic Agents/therapeutic use , Lipid Metabolism , Lipoprotein Lipase/antagonists & inhibitors , Lipoprotein Lipase/genetics , Lipoprotein Lipase/metabolism , Liver/enzymology , Liver/metabolism , Liver/pathology , Male , Mice, Inbred ICR , Obesity/etiology , Obesity/metabolism , Obesity/pathology , Organ Size , Plant Extracts/administration & dosage , Random Allocation , Weight Gain
10.
J Bacteriol ; 200(7)2018 04 01.
Article in English | MEDLINE | ID: mdl-29339417

ABSTRACT

Septicemia-causing Vibrio vulnificus produces at least three exoproteases, VvpE, VvpS, and VvpM, all of which participate in interactions with human cells. Expression of VvpE and VvpS is induced in the stationary phase by multiple transcription factors, including sigma factor S, SmcR, and the cAMP-cAMP receptor protein (cAMP-CRP) complex. Distinct roles of VvpM, such as induction of apoptosis, lead us to hypothesize VvpM expression is different from that of the other exoproteases. Its transcription, which was found to be independent of sigma S, is induced at the early exponential phase and then becomes negligible upon entry into the stationary phase. SmcR and CRP were studied regarding the control of vvpM expression. Transcription of vvpM was repressed by SmcR and cAMP-CRP complex individually, which specifically bound to the regions -2 to +20 and +6 to +27, respectively, relative to the vvpM transcription initiation site. Derepression of vvpM gene expression was 10- to 40-fold greater in an smcR crp double mutant than in single-gene mutants. Therefore, these results show that the expression of V. vulnificus exoproteases is differentially regulated, and in this way, distinct proteases can engage in specific interactions with a host.IMPORTANCE An opportunistic human pathogen, Vibrio vulnificus produces multiple extracellular proteases that are involved in diverse interactions with a host. The total exoproteolytic activity is detected mainly in the supernatants of the high-cell-density cultures. However, some proteolytic activity derived from a metalloprotease, VvpM, was present in the supernatants of the low-cell-density cultures sampled at the early growth period. In this study, we present the regulatory mechanism for VvpM expression via repression by at least two transcription factors. This type of transcriptional regulation is the exact opposite of those for expression of the other V. vulnificus exoproteases. Differential regulation of each exoprotease's production then facilitates the pathogen's participation in the distinct interactions with a host.


Subject(s)
Bacterial Proteins/biosynthesis , Bacterial Proteins/genetics , Gene Expression Regulation, Bacterial , Metalloendopeptidases/biosynthesis , Metalloendopeptidases/genetics , Quorum Sensing , Vibrio vulnificus/genetics , Apoptosis , Cyclic AMP Receptor Protein/metabolism , Enzyme Repression/genetics , Humans , Proteolysis , Transcription Factors/genetics , Vibrio vulnificus/enzymology
11.
DNA Cell Biol ; 37(3): 168-173, 2018 Mar.
Article in English | MEDLINE | ID: mdl-29298087

ABSTRACT

In this study, we investigated the promoter DNA methylation (DNAm) status of the MMP-9 and TIMP-1 genes in patients with chronic periodontitis to evaluate disease progression. Using pyrosequencing technology, DNAm levels of MMP-9 and TIMP-1 CpG islands were measured in 88 chronic periodontitis patients and 15 healthy controls. We found a positive correlation between methylation levels of MMP-9 CpG islands and the severity of chronic periodontitis. Methylated CpG islands were also closely associated with the duration of chronic periodontitis. Moreover, female patients exhibited lower methylation levels of MMP-9 but higher methylation levels of TIMP-1 compared with male patients, and the methylation levels of TIMP-1 gradually decreased with age. The findings of gender disparity in the DNAm of MMP-9 and TIMP-1 genes provide novel insights into chronic periodontitis.


Subject(s)
Chronic Periodontitis/genetics , Matrix Metalloproteinase 9/genetics , Promoter Regions, Genetic , Tissue Inhibitor of Metalloproteinase-1/genetics , Adult , Age Factors , Case-Control Studies , Chronic Periodontitis/metabolism , CpG Islands , DNA Methylation , Enzyme Repression , Female , Gingiva/enzymology , Humans , Male , Matrix Metalloproteinase 9/metabolism , Middle Aged , Sex Characteristics , Tissue Inhibitor of Metalloproteinase-1/metabolism
12.
J Nat Med ; 72(1): 342-346, 2018 Jan.
Article in English | MEDLINE | ID: mdl-29159687

ABSTRACT

The spirostanol saponin AU-1 from Agavaceae plants stimulates the expression of the glycolytic enzyme phosphoglycerate mutase (PGAM) in ACHN cells. We hypothesized that this may arise from the downregulation of the NAD+-dependent deacetylase SIRT1. In this article, we showed that, unlike in renal adenocarcinoma cells, AU-1 does not affect the expression of SIRT1 in the normal renal cell-derived cell line HK-2. Consistent with the lack of a downregulation of SIRT1, AU-1 did not upregulate, but rather decreased PGAM expression. Moreover, AU-1 inhibited the increase in PGAM levels that results from the knock-down of SIRT1. Our results suggest that AU-1 may prevent carcinogenesis caused by increased cellular PGAM.


Subject(s)
Anticarcinogenic Agents/pharmacology , Asparagaceae/chemistry , Phosphoglycerate Mutase/genetics , Plant Extracts/pharmacology , Saponins/pharmacology , Spirostans/pharmacology , Cell Line , Cyclin-Dependent Kinase Inhibitor p21/genetics , Cyclin-Dependent Kinase Inhibitor p21/metabolism , Down-Regulation , Enzyme Repression , Gene Expression/drug effects , Glycolysis , Humans , MicroRNAs/genetics , MicroRNAs/metabolism , Phosphoglycerate Mutase/metabolism , Sirtuin 1/genetics , Sirtuin 1/metabolism
13.
Int J Biochem Cell Biol ; 94: 79-88, 2018 01.
Article in English | MEDLINE | ID: mdl-29208566

ABSTRACT

Osteoarthritis (OA) is the most common joint disease, characterized by articular cartilage degradation and changes in all other joint tissues. MicroRNAs (miRNAs) play an important role in mediating the main risk factors for OA. This study aimed to investigate the effect of miR-26a/26b on the proliferation and apoptosis of human chondrocytes by targeting fucosyltransferase 4 (FUT4) through NF-κB signaling pathway. We revealed the differential expression profiles of FUT4 and miR-26a/26b in the articular cartilage tissues of OA patients and normal people. The ability of miR-26a/26b to specifically interact with the 3'UTR of FUT4 was demonstrated via a luciferase reporter assay in chondrocytes. Further results showed altered levels of miR-26a/26b and FUT4 could regulate the process of IL-1ß-induced extracellular matrix degradation in chondrocytes. Forced miR-26a/26b expression was able to affect chondrocytes proliferation and apoptosis, while altered expression of FUT4 in chondrocytes modulated progression upon transfection with miR-26a/26b mimic or inhibitor. In OA mice, the overexpression of miR-26a/26b by intra-articular injection significantly attenuated OA progression. In addition, regulating FUT4 expression markedly modulated the activity of NF-κB signaling pathway, and this effect could be reversed by miR-26a/26b. In short, miR-26a/-26b/FUT4/NF-κB axis may serve as a predictive biomarker and a potential therapeutic target in OA treatment.


Subject(s)
Cartilage, Articular/metabolism , Chondrocytes/metabolism , Fucosyltransferases/antagonists & inhibitors , Lewis X Antigen/antagonists & inhibitors , MicroRNAs/metabolism , NF-kappa B/metabolism , Osteoarthritis/metabolism , Signal Transduction , 3' Untranslated Regions , Animals , Apoptosis , Cartilage, Articular/immunology , Cartilage, Articular/pathology , Cell Proliferation , Cells, Cultured , Chondrocytes/immunology , Chondrocytes/pathology , Disease Progression , Enzyme Repression , Fucosyltransferases/genetics , Fucosyltransferases/metabolism , Genes, Reporter , Humans , Injections, Intra-Articular , Interleukin-1beta/metabolism , Lewis X Antigen/genetics , Lewis X Antigen/metabolism , Male , MicroRNAs/administration & dosage , MicroRNAs/antagonists & inhibitors , MicroRNAs/therapeutic use , Osteoarthritis/pathology , Osteoarthritis/physiopathology , Osteoarthritis/therapy , RNA/administration & dosage , RNA/therapeutic use , RNA Interference , RNA Isoforms/administration & dosage , RNA Isoforms/antagonists & inhibitors , RNA Isoforms/metabolism , RNA Isoforms/therapeutic use , Rats, Sprague-Dawley
14.
J Pathol ; 244(4): 394-407, 2018 04.
Article in English | MEDLINE | ID: mdl-29230817

ABSTRACT

Nasopharyngeal carcinoma (NPC) is a highly invasive epithelial malignancy that is prevalent in southern China and Southeast Asia. It is consistently associated with latent Epstein-Barr virus (EBV) infection. In NPC, miR-BARTs, the EBV-encoded miRNAs derived from BamH1-A rightward transcripts, are abundantly expressed and contribute to cancer development by targeting various cellular and viral genes. In this study, we establish a comprehensive transcriptional profile of EBV-encoded miRNAs in a panel of NPC patient-derived xenografts and an EBV-positive NPC cell line by small RNA sequencing. Among the 40 miR-BARTs, predominant expression of 22 miRNAs was consistently detected in these tumors. Among the abundantly expressed EBV-miRNAs, BART5-5p, BART7-3p, BART9-3p, and BART14-3p could negatively regulate the expression of a key DNA double-strand break (DSB) repair gene, ataxia telangiectasia mutated (ATM), by binding to multiple sites on its 3'-UTR. Notably, the expression of these four miR-BARTs represented more than 10% of all EBV-encoded miRNAs in tumor cells, while downregulation of ATM expression was commonly detected in all of our tested sequenced samples. In addition, downregulation of ATM was also observed in primary NPC tissues in both qRT-PCR (16 NP and 45 NPC cases) and immunohistochemical staining (35 NP and 46 NPC cases) analysis. Modulation of ATM expression by BART5-5p, BART7-3p, BART9-3p, and BART14-3p was demonstrated in the transient transfection assays. These findings suggest that EBV uses miRNA machinery as a key mechanism to control the ATM signaling pathway in NPC cells. By suppressing these endogenous miR-BARTs in EBV-positive NPC cells, we further demonstrated the novel function of miR-BARTs in inhibiting Zta-induced lytic reactivation. These findings imply that the four viral miRNAs work co-operatively to modulate ATM activity in response to DNA damage and to maintain viral latency, contributing to the tumorigenesis of NPC. © 2017 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.


Subject(s)
Ataxia Telangiectasia Mutated Proteins/genetics , Epstein-Barr Virus Infections/virology , Herpesvirus 4, Human/genetics , MicroRNAs/genetics , Nasopharyngeal Carcinoma/genetics , Nasopharyngeal Neoplasms/genetics , RNA, Viral/genetics , 3' Untranslated Regions , Animals , Ataxia Telangiectasia Mutated Proteins/biosynthesis , Binding Sites , Cell Line, Tumor , DNA Damage , Enzyme Repression , Epstein-Barr Virus Infections/diagnosis , Female , Gene Expression Regulation, Neoplastic , Heterografts , Host-Pathogen Interactions , Humans , Male , Mice, Nude , Middle Aged , Nasopharyngeal Carcinoma/enzymology , Nasopharyngeal Carcinoma/pathology , Nasopharyngeal Carcinoma/virology , Nasopharyngeal Neoplasms/enzymology , Nasopharyngeal Neoplasms/pathology , Nasopharyngeal Neoplasms/virology , Transcriptome , Virus Latency
15.
Mol Med Rep ; 17(1): 1986-1992, 2018 Jan.
Article in English | MEDLINE | ID: mdl-29138848

ABSTRACT

Friend leukemia virus integration 1 (Fli­1) is a newly identified ETS protein, and has critical roles in many malignancies. However, the physiological characters and potential mechanisms of Fli­1 in hepatocellular carcinoma (HCC) progression remains unclear. In the present study, Fli­1 was highly expressed in HCC samples and tumor cell lines. knockdown of Fli­1 with small interfering (si)RNAs significantly reduced the colony formation and metastasis capacity of HCC cell lines in vitro. Subsequent investigation identified that Fli­1 functioned as an oncogene in HCC carcinogenesis and it exerted its promoting metastatic effect primarily by modulating the matrix metalloproteinase (MMP)2 signaling pathway. Collectively, these data provide a novel insight into the mechanism of Fli­1/MMP2 signaling pathway in the pathogenesis of HCC, and Fli­1 may serve as a novel therapeutic target for HCC.


Subject(s)
Carcinoma, Hepatocellular/metabolism , Liver Neoplasms/metabolism , Matrix Metalloproteinase 2/metabolism , Microfilament Proteins/physiology , Receptors, Cytoplasmic and Nuclear/physiology , Carcinoma, Hepatocellular/secondary , Cell Line, Tumor , Cell Movement , Enzyme Repression , Female , Gene Expression , Gene Expression Regulation, Neoplastic , Humans , Liver Neoplasms/pathology , Male , Matrix Metalloproteinase 2/genetics , Middle Aged , Neoplasm Invasiveness , Signal Transduction , Trans-Activators
16.
Curr Biol ; 27(22): 3544-3553.e5, 2017 Nov 20.
Article in English | MEDLINE | ID: mdl-29103937

ABSTRACT

Maintenance of protein homeostasis, or proteostasis, is crucial for organismal health. Disruption of proteostasis can lead to the accumulation of protein aggregates, which are associated with aging and many human diseases such as Alzheimer's disease [1-3]. Through analysis of the C. elegans host response to intracellular infection, we describe here a novel response pathway that enhances proteostasis capacity and appears to act in parallel to well-studied proteostasis pathways. These findings are based on analysis of the transcriptional response to infection by the intracellular pathogen Nematocida parisii [4]. The response to N. parisii is strikingly similar to the response to infection by the Orsay virus, another natural intracellular pathogen of C. elegans, and is distinct from responses to extracellular pathogen infection [4-6]. We have therefore named this common transcriptional response the intracellular pathogen response (IPR), and it includes upregulation of several predicted ubiquitin ligase complex components such as the cullin cul-6. Through a forward genetic screen we found pals-22, a gene of previously unknown function, to be a repressor of the cul-6/cullin gene and other IPR gene expression. Interestingly, pals-22 mutants have increased thermotolerance and reduced levels of stress-induced polyglutamine aggregates, likely due to upregulated IPR gene expression. We found the enhanced stress resistance of pals-22 mutants to be dependent on cul-6, suggesting that pals-22 mutants have increased activity of a CUL-6/cullin-containing ubiquitin ligase complex. pals-22 mutant phenotypes appear independent of the well-studied heat shock and insulin signaling pathways, indicating that the IPR is a distinct pathway that protects animals from proteotoxic stress.


Subject(s)
Proteostasis/genetics , Proteostasis/physiology , Animals , Antinematodal Agents , Caenorhabditis elegans/genetics , Caenorhabditis elegans/microbiology , Caenorhabditis elegans/physiology , Caenorhabditis elegans Proteins/antagonists & inhibitors , Caenorhabditis elegans Proteins/biosynthesis , Caenorhabditis elegans Proteins/metabolism , Cullin Proteins/antagonists & inhibitors , Cullin Proteins/biosynthesis , Cytoplasm/metabolism , Enzyme Repression , Host-Pathogen Interactions/physiology , Microsporidia , Ubiquitin/metabolism
17.
J Nutr Biochem ; 50: 46-53, 2017 12.
Article in English | MEDLINE | ID: mdl-29031242

ABSTRACT

Recent studies have shown that dietary creatine supplementation can prevent lipid accumulation in the liver. Creatine is a small molecule that plays a large role in energy metabolism, but since the enzyme creatine kinase is not present in the liver, the classical role in energy metabolism does not hold in this tissue. Fat accumulation in the liver can lead to the development of nonalcoholic fatty liver disease (NAFLD), a progressive disease that is prevalent in humans. We have previously reported that creatine can directly influence lipid metabolism in cell culture to promote lipid secretion and oxidation. Our goal in the current study was to determine whether similar mechanisms that occur in cell culture were present in vivo. We also sought to determine whether dietary creatine supplementation could be effective in reversing steatosis. Sprague-Dawley rats were fed a high-fat diet or a high-fat diet supplemented with creatine for 5 weeks. We found that rats supplemented with creatine had significantly improved rates of lipoprotein secretion and alterations in mitochondrial function that were consistent with greater oxidative capacity. We also find that introducing creatine into a high-fat diet halted hepatic lipid accumulation in rats with fatty liver. Our results support our previous report that liver cells in culture with creatine secrete and oxidize more oleic acid, demonstrating that dietary creatine can effectively change hepatic lipid metabolism by increasing lipoprotein secretion and oxidation in vivo. Our data suggest that creatine might be an effective therapy for NAFLD.


Subject(s)
Creatine/therapeutic use , Dietary Supplements , Lipoproteins/metabolism , Lipotropic Agents/therapeutic use , Liver/metabolism , Non-alcoholic Fatty Liver Disease/diet therapy , Triglycerides/metabolism , Animals , Biomarkers/blood , Biomarkers/metabolism , Cholesterol Esters/blood , Cholesterol Esters/metabolism , Creatine/adverse effects , Cytokines/blood , Cytokines/metabolism , Diet, High-Fat/adverse effects , Dietary Supplements/adverse effects , Enzyme Repression , Inflammation Mediators/blood , Inflammation Mediators/metabolism , Lipid Droplets/metabolism , Lipid Droplets/pathology , Lipoproteins/blood , Lipotropic Agents/adverse effects , Liver/immunology , Liver/pathology , Mitochondria, Liver/immunology , Mitochondria, Liver/metabolism , Mitochondria, Liver/pathology , Mitochondrial Proton-Translocating ATPases/antagonists & inhibitors , Mitochondrial Proton-Translocating ATPases/genetics , Mitochondrial Proton-Translocating ATPases/metabolism , Non-alcoholic Fatty Liver Disease/immunology , Non-alcoholic Fatty Liver Disease/metabolism , Non-alcoholic Fatty Liver Disease/pathology , Organ Size , Oxidation-Reduction , Random Allocation , Rats, Sprague-Dawley , Triglycerides/blood , Voltage-Dependent Anion Channels/antagonists & inhibitors , Voltage-Dependent Anion Channels/genetics , Voltage-Dependent Anion Channels/metabolism
18.
J Nutr Biochem ; 49: 63-70, 2017 11.
Article in English | MEDLINE | ID: mdl-28886438

ABSTRACT

Ubiquitin-specific protease 19 (USP19) is a key player in the negative regulation of muscle mass during muscle atrophy. Loss-of-function approaches demonstrate that 17ß-estradiol (E2) increases USP19 expression through estrogen receptor (ER) α and consequently decreases soleus muscle mass in young female mice under physiological conditions. Daidzein is one of the main isoflavones in soy, and activates ERß-dependent transcription. Here, we investigated the effects of daidzein on E2-increased USP19 expression and E2-decreased soleus muscle mass in young female mice. Daidzein stimulated the transcriptional activity of ERß in murine C2C12 cells and down-regulated USP19 expression. Consistently, daidzein inhibited E2-induced USP19 expression in a reporter activity using a functional half-estrogen response element (hERE) from Usp19. Daidzein inhibited E2-induced recruitment of ERα and promoted recruitment of ERß to the Usp19 hERE. Dietary daidzein down-regulated the expression of USP19 at the mRNA and protein levels and increased soleus muscle mass in female mice, but not in males. In soleus muscle from ovariectomized (OVX) female mice, dietary daidzein inhibited E2-increased USP19 mRNA expression and E2-decreased muscle mass. Furthermore, E2 induced the recruitment of ERα and ERß to the hERE, whereas daidzein inhibited E2-induced recruitment of ERα, and enhanced E2-increased recruitment of ERß, to the Usp19 hERE. These results demonstrate that dietary daidzein decreases USP19 mRNA expression through ERß and increases soleus muscle mass in young female mice, but not in male mice, under physiological conditions.


Subject(s)
Dietary Supplements , Estrogen Receptor beta/agonists , Isoflavones/therapeutic use , Muscle, Skeletal/metabolism , Phytoestrogens/therapeutic use , Sarcopenia/prevention & control , Ubiquitin-Specific Proteases/antagonists & inhibitors , Active Transport, Cell Nucleus , Animals , Animals, Outbred Strains , Cell Line , Endopeptidases , Enzyme Repression , Estrogen Receptor beta/genetics , Estrogen Receptor beta/metabolism , Female , Genes, Reporter , Male , Mice , Muscle, Skeletal/enzymology , Muscle, Skeletal/pathology , Myoblasts, Skeletal/cytology , Myoblasts, Skeletal/enzymology , Myoblasts, Skeletal/metabolism , Myoblasts, Skeletal/pathology , Ovariectomy/adverse effects , Random Allocation , Response Elements , Sarcopenia/etiology , Sarcopenia/metabolism , Sarcopenia/pathology , Sex Characteristics , Signal Transduction , Ubiquitin-Specific Proteases/genetics , Ubiquitin-Specific Proteases/metabolism
19.
Mol Microbiol ; 106(2): 266-284, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28787542

ABSTRACT

Transmission of the malaria parasite occurs in an unpredictable moment, when a mosquito takes a blood meal. Plasmodium has therefore evolved strategies to prepare for transmission, including translationally repressing and protecting mRNAs needed to establish the infection. However, mechanisms underlying these critical controls are not well understood, including whether Plasmodium changes its translationally repressive complexes and mRNA targets in different stages. Efforts to understand this have been stymied by severe technical limitations due to substantial mosquito contamination of samples. Here using P. yoelii, for the first time we provide a proteomic comparison of a protein complex across asexual blood, sexual and sporozoite stages, along with a transcriptomic comparison of the mRNAs that are affected in these stages. We find that the Apicomplexan-specific ALBA4 RNA-binding protein acts to regulate development of the parasite's transmission stages, and that ALBA4 associates with both stage-specific and stage-independent partners to produce opposing mRNA fates. These efforts expand our understanding and ability to interrogate both sexual and sporozoite transmission stages and the molecular preparations they evolved to perpetuate their infectious cycle.


Subject(s)
Plasmodium yoelii/physiology , RNA, Messenger/biosynthesis , Animals , Anopheles/parasitology , Enzyme Repression , Malaria/parasitology , Parasites , Parasitic Diseases/genetics , Plasmodium yoelii/genetics , Plasmodium yoelii/growth & development , Proteomics , Protozoan Proteins/metabolism , RNA, Messenger/metabolism , RNA-Binding Proteins/metabolism , Sporozoites/metabolism , Transcriptome
20.
Int J Chron Obstruct Pulmon Dis ; 12: 1781-1791, 2017.
Article in English | MEDLINE | ID: mdl-28684904

ABSTRACT

Hypoxia-induced pulmonary hypertension, which is characterized by vascular remodeling of blood vessels, is an important complication in COPD. In this study, we found that the expression of miR-214 was differentially expressed by screening 13 candidate miRNAs in pulmonary artery smooth muscle cells (PASMCs). Additionally, using luciferase assay in PASMCs, we found that phosphatase-and-tensin homolog (PTEN) was a target of miR-214. Furthermore, the expression of PTEN was found to be substantially downregulated in PASMCs from COPD patients with pulmonary hypertension (PH) compared with normal controls by using real-time polymerase chain reaction (PCR), immunohistochemistry, and Western blot. In addition, we transfected PASMCs with miR-214 mimics, using real-time PCR and Western blotting, to confirm the miRNA/mRNA relationship. Furthermore, the introduction of miR-214 significantly promoted the proliferation of PASMCs by suppressing apoptosis of the cells, which was mediated by the downregulation of PTEN. Exposure to hypoxia significantly increased the expression of miR-214 and decreased the expression of PTEN in PASMCs, and its proliferation was significantly promoted. Such effects could be significantly attenuated by the introduction of miR-214 inhibitors, which significantly downregulated miR-214 expression and upregulated the expression of PTEN. In conclusion, hypoxia-induced upregulation of miR-214 was found to promote PH development by targeting PTEN in PASMCs, and miR-214 could be a promising diagnostic tool and novel therapeutic target in the management of hypoxia-induced PH in COPD.


Subject(s)
Hypertension, Pulmonary/enzymology , Hypoxia/complications , MicroRNAs/metabolism , Muscle, Smooth, Vascular/enzymology , Myocytes, Smooth Muscle/enzymology , PTEN Phosphohydrolase/metabolism , Aged , Apoptosis , Case-Control Studies , Cell Proliferation , Cells, Cultured , Enzyme Repression , Female , Humans , Hypertension, Pulmonary/diagnosis , Hypertension, Pulmonary/genetics , Hypertension, Pulmonary/pathology , Male , MicroRNAs/genetics , Middle Aged , Muscle, Smooth, Vascular/pathology , Myocytes, Smooth Muscle/pathology , PTEN Phosphohydrolase/genetics , Pulmonary Artery/enzymology , Pulmonary Artery/pathology , RNA, Messenger/genetics , RNA, Messenger/metabolism , Transfection
SELECTION OF CITATIONS
SEARCH DETAIL
...