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1.
Article in Chinese | WPRIM | ID: wpr-927900

ABSTRACT

Objective: To investigate the mechanism that hypoxia promotes the migration of lung adenocarcinoma A549 cells. Methods: A549 cells were cultured and cells that knockdown of acetyl-CoA carboxylase 1 (ACC1) were obtained by transfection with lentivirus, and cells that knockdown of sterol regulatory element-binding proteins-1 (SREBP-1) were obtained by treated with si-RNA. A549 cells were treated with hypoxia combined with hypoxia inducible factor-1α (HIF-1α) inhibitor PX-478 (25 μmol); Hypoxia combined with linoleic acid (LA) (20 μmol) treated A549 cells with ACC1 knockdown, and A549 cells with SREBP-1 knockdown were treated by hypoxia. Transwell migration assay was used to detect cell migration. Western blot was conducted to detect HIF-1α, ACC1 and epithelial mesenchymal transition (EMT) related proteins, Vimentin, E-Cadherin and SREBP-1; Real-time fluorescent quantitative polymerase chain reaction (RT-qPCR) was performed to detect the changes of ACC1 and SREBP-1 mRNA in A549 cells after hypoxia and HIF-1α inhibitor PX-478 (25 μmol) treatment. Each experiment was repeated three times. Results: Compared with the normoxic control group, hypoxia promoted the migration of A549 cells (P<0.01), and up-regulated the expressions of ACC1, HIF-1α (all P<0.01) and SREBP-1 (P<0.05). PX-478 (25 μmol) inhibited the migration of A549 cells induced by hypoxia and down-regulated the expression of SREBP-1 (all P<0.05). ACC1 mRNA and SREBP-1 mRNA levels were increased after hypoxia treatment of A549 cells (all P<0.05). The levels of ACC1 mRNA and SREBP-1 mRNA were decreased after A549 cells treated with hypoxia combined with PX-478 (25 μmol) for 24 h (P<0.05, P<0.01). Knockdown of SREBP-1 in A549 cells was obtained by transfection with si-RNA. Transwell migration assay showed the number of cell migration in si-SREBP-1 group was less than that in normoxia control group (P<0.01). The si-SREBP-1 group and the si-NC group were treated with hypoxia. Compared with the control group, the number of cell migration in the si-SREBP-1 group was decreased (P<0.01), however, the difference was not statistically significant compared with the normoxia si-SREBP-1 group (P>0.05). Western blot showed that the expression of ACC1 in the si-SREBP-1 group was lower than that in the control group (P<0.01). Compared with the control group, the expression of ACC1 was decreased after si-SREBP-1 group treated with hypoxia (P<0.01). Knockdown of ACC1 inhibited the migration of A549 cells (P<0.05). After knockdown of ACC1, the migration number of A549 cells under normoxia and 5% O2 conditions had no significant difference (P>0.05). Application of LA under hypoxia condition rescued ACC1-knockdown induced inhibitory effect on hypoxia-promoted A549 cell migration (P<0.05). Conclusion: Hypoxia promotes migration of lung adenocarcinoma A549 cells by regulating fatty acid metabolism through HIF-1α/SREBP-1/ACC1 pathway.


Subject(s)
A549 Cells , Acetyl-CoA Carboxylase , Adenocarcinoma of Lung , Cell Hypoxia/physiology , Cell Line, Tumor , Humans , Hypoxia , Hypoxia-Inducible Factor 1, alpha Subunit , Lung Neoplasms , RNA/metabolism , RNA, Messenger/metabolism , Sterol Regulatory Element Binding Protein 1/metabolism
2.
Braz. j. med. biol. res ; 54(10): e11391, 2021. tab, graf
Article in English | LILACS | ID: biblio-1285650

ABSTRACT

Nonalcoholic fatty liver disease (NAFLD), characterized by hepatosteatosis and steatohepatitis, is intrinsically related to obesity. Our previous study reported on the anti-obese activity of α,β-amyrin (AMY), a pentacyclic triterpene isolated from Protium heptaphyllum. This study investigated its ability to prevent fatty liver and the underlying mechanism using the mouse model of NAFLD. NAFLD was induced in male Swiss mice fed a high fat diet (HFD) for 15 weeks. The controls were fed a normal chow diet (ND). The mice were simultaneously treated with AMY at 10 and 20 mg/kg or fenofibrate at 50 mg/kg. Lipid levels along with metabolic and inflammatory parameters were assessed in liver and serum. The liver sections were histologically examined using H&E staining. RT-qPCR and western blotting assays were performed to analyze signaling mechanisms. Mice fed HFD developed severe hepatic steatosis with elevated triglycerides and lipid droplets compared with ND controls. This was associated with a decrease in AMP-activated protein kinase (AMPK) activity, an increase of mechanistic target of rapamycin complex 1 (mTORC1) signaling, and enhanced sterol regulatory element binding protein 1 (SREBP1) expression, which have roles in lipogenesis, inhibition of lipolysis, and inflammatory response. AMY treatment reversed these signaling activities and decreased the severity of hepatic steatosis and inflammatory response, evidenced by serum and liver parameters as well as histological findings. AMY-induced reduction in hepatic steatosis seemed to involve AMPK-mTORC1-SREBP1 signaling pathways, which supported its beneficial role in the prevention and treatment of NAFLD.


Subject(s)
Animals , Male , Rabbits , Insulin Resistance , Non-alcoholic Fatty Liver Disease/prevention & control , Non-alcoholic Fatty Liver Disease/drug therapy , Oleanolic Acid/analogs & derivatives , Sterol Regulatory Element Binding Protein 1 , AMP-Activated Protein Kinases , Diet, High-Fat/adverse effects , Mechanistic Target of Rapamycin Complex 1 , Liver , Mice, Inbred C57BL
3.
Biol. Res ; 53: 50, 2020. tab, graf
Article in English | LILACS | ID: biblio-1142417

ABSTRACT

BACKGROUND: Acupuncture, a therapy of traditional Chinese medicine, is confirmed to exert the therapeutic action on polycystic ovary syndrome (PCOS). However, the detailed therapeutic mechanisms of acupuncture in PCOS remain ambiguous. In this study, we further investigated whether electroacupuncture (EA) alleviated PCOS-like symptoms in rats via regulating a metabolic regulator, sterol regulatory element binding protein-1 (SREBP1). Methods: The PCOS-like rat model was built by hypodermic injection with dehydroepiandrosterone (DHEA). The rats were subjected to EA intervention (ST29 and SP6 acupuncture points) for 5 weeks. Primary granulosa cells were isolated from control and PCOS-like rats for evaluating insulin resistance, mitochondrial dysfunction and oxidative stress in vitro. RESULTS: The expression of SREBP1 was increased in PCOS-like rats, which was suppressed by EA treatment. In addition, lentivirus-mediated overexpression of SREBP1 restrained EA treatment-induced improvement in pathological changes, serum hormone levels and insulin resistance in rats. In addition, overexpression of SREBP1 repressed insulin-stimulated phosphorylation of insulin receptor ß (IR) and AKT in primary granulosa cells. Moreover, upregulation of SREBP1 further exacerbated mitochondrial dysfunction and oxidative stress in granulosa cells isolated from PCOS-like rats. Mechanically, EA treatment suppressed SREBP1 expression through inducing the activation of AMP-activated protein kinase (AMPK) signaling pathway in PCOS-like rats. CONCLUSION: EA intervention alleviated PCOS-like symptoms in rats via improving IR, mitochondrial dysfunction and oxidative stress through regulating SREBP1, a lipid metabolism regulator. Our findings illuminate the novel protective mechanisms of EA in the treatment of PCOS.


Subject(s)
Animals , Female , Rats , Polycystic Ovary Syndrome/chemically induced , Polycystic Ovary Syndrome/therapy , Insulin Resistance , Electroacupuncture , Oxidative Stress , Sterol Regulatory Element Binding Protein 1/metabolism , Mitochondria/pathology , Rats, Sprague-Dawley , Dehydroepiandrosterone
4.
Rev. Assoc. Med. Bras. (1992) ; 65(9): 1144-1150, Sept. 2019. tab, graf
Article in English | LILACS | ID: biblio-1041074

ABSTRACT

SUMMARY OBJECTIVE In view of the high incidence of polycystic ovary syndrome (PCOS) and the unsatisfactory therapeutic effects of dimethyldiguanide or clomifene citrate alone, our study aimed to investigate the therapeutic effects of dimethyldiguanide combined with clomifene citrate in the treatment of PCOS. METHODS A total of 79 patients with POCS and 35 healthy females were included, and endometrial biopsies were obtained. The sterol regulatory element-binding protein-1 (SREBP1) expression in endometrial tissues was detected by qRT-PCR. POC patients were randomly divided into group A (n=40) and group B (n=39). Patients in group A were treated with dimethyldiguanide combined with clomifene citrate, while patients in group B were treated with clomifene citrate alone. The number of mature follicles and cervical mucus score, follicular development rate and single follicle ovulation rate, cycle pregnancy rate, early miscarriage rate, ovulation rate, endometrial thickness, positive rate of three lines sign, follicle stimulating hormone level and luteinizing hormone level were compared between the two groups. RESULTS The expression level of SREBP1 was higher in PCOS patients than that in the healthy control. SREBP1 expression was inhibited after treatment, while the inhibitory effects of combined treatment were stronger than those of clomifene citrate alone. Compared with clomifene citrate alone, the combined treatment improved cervical mucus score, follicle development rate, single follicle ovulation rate, endometrial thickness, positive rate of three lines sign, and follicle-stimulating hormone level. CONCLUSION The therapeutic effect of combined treatment is better than clomifene citrate alone in the treatment of PCOS.


RESUMO OBJETIVO Tendo em vista a alta incidência de síndrome dos ovários policísticos (SOP) e os efeitos terapêuticos insatisfatórios da dimetildiguanida ou do citrato de clomifeno isoladamente, nosso estudo teve como objetivo investigar os efeitos terapêuticos da dimetildiguanida associada ao citrato de clomifeno no tratamento da SOP. MÉTODOS Um total de 79 pacientes com POCS e 35 mulheres saudáveis foram incluídos, e biópsias endometriais foram obtidas. A expressão da proteína de ligação do elemento regulador de esterol-1 (SREBP1) nos tecidos endometriais foi detectada por qRT-PCR. Pacientes POC foram divididos aleatoriamente em grupo A (n=40) e grupo B (n=39). Os pacientes do grupo A foram tratados com dimetildiguanida combinada com citrato de clomifeno, enquanto os pacientes do grupo B foram tratados apenas com citrato de clomifeno. O número de folículos maduros e muco cervical, taxa de desenvolvimento folicular e taxa de ovulação, taxa de gravidez, abortamento precoce, taxa de ovulação, espessura endometrial, taxa positiva de três linhas, nível de hormônio folículo estimulante e nível de hormônio luteinizante foram comparados entre os dois grupos. RESULTADOS O nível de expressão do SREBP1 foi maior nos pacientes com SOP do que no controle normal. A expressão de SREBP1 foi inibida após o tratamento, enquanto os efeitos inibidores do tratamento combinado foram mais fortes do que os do citrato de clomifeno isoladamente. Comparado com o citrato de clomifeno sozinho, o tratamento combinado melhorou significativamente a pontuação do muco cervical, a taxa de desenvolvimento folicular, a taxa de ovulação do folículo único, a espessura endometrial, a taxa positiva de três linhas de sinal e o nível de hormônio folículo estimulante. CONCLUSÃO O efeito terapêutico do tratamento combinado é melhor do que o citrato de clomifeno isolado no tratamento da SOP.


Subject(s)
Humans , Female , Adult , Young Adult , Polycystic Ovary Syndrome/drug therapy , Clomiphene/therapeutic use , Fertility Agents, Female/therapeutic use , Hypoglycemic Agents/therapeutic use , Metformin/therapeutic use , Ovulation Induction , Cervix Mucus/drug effects , Gene Expression Regulation/drug effects , Clomiphene/pharmacology , Drug Therapy, Combination , Endometrium/physiopathology , Sterol Regulatory Element Binding Protein 1/adverse effects , Sterol Regulatory Element Binding Protein 1/genetics , Fertility Agents, Female/pharmacology , Ovarian Follicle/drug effects , Hypoglycemic Agents/pharmacology , Metformin/pharmacology
5.
Article in Chinese | WPRIM | ID: wpr-773652

ABSTRACT

The aim of this paper was to investigate the molecular mechanism of Calculus Bovis Sativus( CBS) in alleviating lipid accumulation in vitro by serum pharmacology. The CBS-containing serum of mice was obtained by serum pharmacology method to evaluate its effect on the proliferation of LO2 hepatocytes. The lipid reducing effects of CBS-containing serum through Nrf2 was evaluated by fructose-induced LO2 hepatocyte steatosis model,nuclear factor erythroid 2 related factor 2( Nrf2) agonist oltipraz combined intervention,cell oil red O staining and intracellular triglyceride( TG) content. The effects of CBS-containing serum on lipid peroxidation and hepatocytes apoptosis were evaluated by reactive oxygen species( ROS) and apoptosis assay,respectively. Real-time quantitative polymerase chain reaction( PCR) was used to detect the relative expression of lipid synthesis-related genes and apoptosis-related genes.RESULTS:: showed that CBS drug-containing serum had no significant effect on LO2 hepatocyte proliferation. As compared with the model group,CBS-containing serum could effectively reduce the formation of lipid droplets in fructose-induced LO2 hepatocytes,significantly reduce intracellular TG and ROS levels,and significantly reduce hepatocyte apoptosis rate( P < 0. 05). As compared with the model group,carbohydrate responsive element binding protein( ChREBP),sterol regulatory element binding protein-1 c( SREBP-1 c),fatty acid synthase( FAS),acetyl-CoA carboxylase 1( ACC1),stearoyl-CoA desaturase 1( SCD1),Bax and caspase-3 mRNA levels were significantly reduced in CBS drug-containing serum treatment group( P<0. 05). All of the above effects could be reversed by oltipraz.In conclusion,CBS-containing serum can significantly inhibit the fructose-induced LO2 liver fat deposition,and the mechanism may be related to reducing intracellular ROS level through the Nrf2 pathway and improving intracellular peroxidation state to reduce apoptosis.


Subject(s)
Animals , Apoptosis , Cattle , Cells, Cultured , Fatty Liver , Fructose , Gallstones , Chemistry , Hepatocytes , Cell Biology , Metabolism , Lipid Metabolism , Lipid Peroxidation , Liver , Medicine, Chinese Traditional , Mice , Reactive Oxygen Species , Metabolism , Serum , Chemistry , Sterol Regulatory Element Binding Protein 1 , Metabolism , Triglycerides
6.
Biol. Res ; 52: 60, 2019. graf
Article in English | LILACS | ID: biblio-1100912

ABSTRACT

BACKGROUND: Recent studies have confirmed that RASAL1 has an antitumor effect in many cancers, but its functional role and the molecular mechanism underlying in colon cancer has not been investigated. RESULTS: We collected human colon cancer tissues and adjacent non-tumor tissues, human colon cancer cell lines LoVo, CaCo2, SW1116, SW480 and HCT-116, and normal colonic mucosa cell line NCM460. RT-qPCR was used to detect the RASAL1 level in the clinical tissues and cell lines. In LoVo and HCT-116, RASAL1 was artificially overexpressed. Cell viability and proliferation were measured using CCK-8 assays, and cell cycle was detected via PI staining and flow cytometry analysis. RASAL1 significantly inhibited the cell proliferation via inducing cell cycle arrest, suppressed cell cycle associated protein expression, and decreased the lipid content and inhibited the SCD1 expression. Moreover, SCD1 overexpression induced and downregulation repressed cell proliferation by causing cell cycle arrest. Additionally, luciferase reporter assays were performed to confirm the direct binding between SREBP1c, LXRα; and SCD1 promoter, we also demonstrated that RASAL1 inhibit SCD1 3'-UTR activity. RASAL1 inhibited tumor growth in xenograft nude mice models and shows inhibitory effect of SCD1 expression in vivo. CONCLUSION: Taken together, we concluded that RASAL1 inhibited colon cancer cell proliferation via modulating SCD1 activity through LXRα/SREBP1c pathway.


Subject(s)
Humans , Animals , Mice , Stearoyl-CoA Desaturase/metabolism , Colonic Neoplasms/pathology , GTPase-Activating Proteins/metabolism , Cell Proliferation/physiology , Sterol Regulatory Element Binding Protein 1/metabolism , Liver X Receptors/metabolism , Stearoyl-CoA Desaturase/genetics , Down-Regulation , GTPase-Activating Proteins/genetics , Cell Line, Tumor , Sterol Regulatory Element Binding Protein 1/genetics , Liver X Receptors/genetics
7.
Article in Korean | WPRIM | ID: wpr-740553

ABSTRACT

PURPOSE: Obesity is a major health problem of global significance because it is clearly associated with an increased risk of health problems, such as nonalcoholic fatty liver disease (NAFLD), diabetes, cardiovascular diseases, and cancer. Lonicera caerulea (LC) originates from high mountains or wet areas and has been used as a traditional medicine in northern Russia, China, and Japan. LC contains a range of bioactive constituents, such as vitamins, minerals, and polyphenols. This study examined the anti-obesity effects of LC during differentiation in preadipocytes. METHODS: The cell viability assay was performed after the differentiation of 3T3-L1 cells for 7 days. Oil Red O staining was used to visualize the changes in lipid droplets in 3T3-L1 cells and mouse adipose-derived stem cells (MADSCs). The mRNA expression of obesity-related genes was determined by quantitative real-time PCR. RESULTS: According to the results of Oil Red O staining, the lipid levels and size of lipid droplets in the adipocytes were reduced and the LC extract (LCE, 0.25–1 mg/mL) markedly inhibited adipogenesis in a dose-dependent manner. The treatment of LCE also decreased the mRNA expression of peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer binding protein-α (C/EBPα), and sterol regulatory element binding protein 1 (SREBP1) in 3T3-L1 cells. Western blot analysis showed that the PPARγ, C/EBPα, and SREBP1 protein levels in both 3T3-L1 and MADSC were reduced in a dose-dependent manner. CONCLUSION: These results suggest that LCE can inhibit adipogenic differentiation through the regulation of adipogenesis-related markers.


Subject(s)
3T3-L1 Cells , Adipocytes , Adipogenesis , Animals , Blotting, Western , Cardiovascular Diseases , Cell Survival , China , Japan , Lipid Droplets , Lonicera , Medicine, Traditional , Mice , Minerals , Miners , Non-alcoholic Fatty Liver Disease , Obesity , Peroxisomes , Polyphenols , Real-Time Polymerase Chain Reaction , RNA, Messenger , Russia , Stem Cells , Sterol Regulatory Element Binding Protein 1 , Vitamins
8.
Article in English | WPRIM | ID: wpr-760610

ABSTRACT

BACKGROUND/OBJECTIVES: Non-alcoholic fatty liver disease (NAFLD) is a common metabolic disease triggered by epigenetic alterations, including lysine acetylation at histone or non-histone proteins, affecting the stability or transcription of lipogenic genes. Although various natural dietary compounds have anti-lipogenic effects, their effects on the acetylation status and lipid metabolism in the liver have not been thoroughly investigated. MATERIALS/METHODS: Following oleic-palmitic acid (OPA)-induced lipid accumulation in HepG2 cells, the acetylation status of histone and non-histone proteins, HAT activity, and mRNA expression of representative lipogenic genes, including PPARγ, SREBP-1c, ACLY, and FASN, were evaluated. Furthermore, correlations between lipid accumulation and HAT activity for 22 representative natural food extracts (NExs) were evaluated. RESULTS: Non-histone protein acetylation increased following OPA treatment and the acetylation of histones H3K9, H4K8, and H4K16 was accelerated, accompanied by an increase in HAT activity. OPA-induced increases in the mRNA expression of lipogenic genes were down-regulated by C-646, a p300/CBP-specific inhibitor. Finally, we detected a positive correlation between HAT activity and lipid accumulation (Pearson's correlation coefficient = 0.604) using 22 NExs. CONCLUSIONS: Our results suggest that NExs have novel applications as nutraceutical agents with HAT inhibitor activity for the prevention and treatment of NAFLD.


Subject(s)
Acetylation , Dietary Supplements , Epigenomics , Hep G2 Cells , Histone Acetyltransferases , Histones , Lipid Metabolism , Lipogenesis , Liver , Lysine , Metabolic Diseases , Non-alcoholic Fatty Liver Disease , RNA, Messenger , Sterol Regulatory Element Binding Protein 1
9.
Article in English | WPRIM | ID: wpr-773584

ABSTRACT

Farnesoid X receptor (FXR) is a member of the nuclear receptor superfamily of ligand-activated transcription factors. As a metabolic regulator, FXR plays key roles in bile acid and cholesterol metabolism and lipid and glucose homeostasis. Therefore, FXR is a potential drug target for several metabolic syndromes, especially those related to lipidemia disorders. In the present study, we identified small molecule SIPI-7623, a derivative of an extract from Oriental wormwood (Artemisia capillaris), and found that it specifically upregulated the expression of cholesterol-7-alpha-hydroxylase (CYP7A1), downregulated the expression of sterol-regulatory element-binding protein 1c (SREBP-1c) in the liver, and inhibited the expression of ileal bile acid binding-protein (IBABP) in the ileum of rats. We found that inhibition of FXR by SIPI-7623 decreased the level of cholesterol and triglyceride. SIPI-7623 reduced the levels of cholesterol and triglyceride in in vitro HepG2 cell models, ameliorated diet-induced atherosclerosis, and decreased the serum lipid content on rats and rabbits model of atherosclerosis in vivo. Furthermore, SIPI-7623 decreased the extent of atherosclerotic lesions. Our resutls demonstrated that antagonism of the FXR pathway can be employed as a therapeutic strategy to treat metabolic diseases such as hyperlipidemia and atherosclerosis. In conclusion, SIPI-7623 could be a promising lead compound for development of drugs to treat hyperlipidemia and atherosclerosis.


Subject(s)
Animals , Artemisia , Chemistry , Atherosclerosis , Drug Therapy , Genetics , Metabolism , Cholesterol , Metabolism , Cholesterol 7-alpha-Hydroxylase , Genetics , Metabolism , Drugs, Chinese Herbal , Humans , Hyperlipidemias , Drug Therapy , Genetics , Metabolism , Hypolipidemic Agents , Liver , Metabolism , Male , Rabbits , Rats , Rats, Sprague-Dawley , Receptors, Cytoplasmic and Nuclear , Genetics , Metabolism , Sterol Regulatory Element Binding Protein 1 , Genetics , Metabolism , Triglycerides , Metabolism
10.
Article in English | WPRIM | ID: wpr-713830

ABSTRACT

BACKGROUND/OBJECTIVES: Non-alcoholic fatty liver disease (NAFLD) is a leading cause of chronic liver disease and is closely associated with metabolic syndrome. In the present study, we observed the effect of ethanol extract of Allium fistulosum (EAF) on NAFLD and have suggested the possibility of using EAF as a natural product for application in the development of a treatment for NAFLD. MATERIALS/METHODS: The preventive effect on hepatic lipid accumulation was estimated by using an oleic acid (OA)-induced NAFLD model in vitro and a Western diet (high-fat high-sucrose; WD)-induced obese mouse model. Animals were divided into three groups (n = 7): normal diet group (ND), WD group, and WD plus 1% EAF group. RESULTS: EAF reduced OA-stimulated lipid accumulation in HepG2 cells in the absence of cellular cytotoxicity and significantly blocked transcriptional activation of sterol regulatory element-binding protein 1 and fatty acid synthase genes. Subsequently, we investigated these effects in vivo in mice fed either ND or WD in the presence or absence of EAF supplementation. In comparison to the ND controls, the WD-fed mice exhibited increases in body weight, liver weight, epididymal fat weight, and accumulation of fat in hepatocytes, and these effects were significantly attenuated by EAF supplementation. CONCLUSIONS: Allium fistulosum attenuates the development of NAFLD, and EAF elicits anti-lipogenic activity in liver. Therefore, EAF represents a promising candidate for use in the development of novel therapeutic drugs or drug combinations for the prevention and treatment of NAFLD.


Subject(s)
Allium , Animals , Body Weight , Diet , Diet, Western , Drug Combinations , Ethanol , Hep G2 Cells , Hepatocytes , In Vitro Techniques , Lipogenesis , Liver , Liver Diseases , Mice , Mice, Obese , Non-alcoholic Fatty Liver Disease , Oleic Acid , Sterol Regulatory Element Binding Protein 1 , Transcriptional Activation
11.
Article in English | WPRIM | ID: wpr-727941

ABSTRACT

Cushing's syndrome (CS) is a collection of symptoms caused by prolonged exposure to excess cortisol. Chronically elevated glucocorticoid (GC) levels contribute to hepatic steatosis. We hypothesized that histone deacetylase inhibitors (HDACi) could attenuate hepatic steatosis through glucocorticoid receptor (GR) acetylation in experimental CS. To induce CS, we administered adrenocorticotropic hormone (ACTH; 40 ng/kg/day) to Sprague-Dawley rats by subcutaneous infusion with osmotic mini-pumps. We administered the HDACi, sodium valproate (VPA; 0.71% w/v), in the drinking water. Treatment with the HDACi decreased steatosis and the expression of lipogenic genes in the livers of CS rats. The enrichment of GR at the promoters of the lipogenic genes, such as acetyl-CoA carboxylase (Acc), fatty acid synthase (Fasn), and sterol regulatory element binding protein 1c (Srebp1c), was markedly decreased by VPA. Pan-HDACi and an HDAC class I-specific inhibitor, but not an HDAC class II a-specific inhibitor, attenuated dexamethasone (DEX)-induced lipogenesis in HepG2 cells. The transcriptional activity of Fasn was decreased by pretreatment with VPA. In addition, pretreatment with VPA decreased DEX-induced binding of GR to the glucocorticoid response element (GRE). Treatment with VPA increased the acetylation of GR in ACTH-infused rats and DEX-induced HepG2 cells. Taken together, these results indicate that HDAC inhibition attenuates hepatic steatosis hrough GR acetylation in experimental CS.


Subject(s)
Acetyl-CoA Carboxylase , Acetylation , Adrenocorticotropic Hormone , Animals , Cushing Syndrome , Dexamethasone , Drinking Water , Hep G2 Cells , Histone Deacetylase Inhibitors , Histone Deacetylases , Histones , Hydrocortisone , Infusions, Subcutaneous , Lipogenesis , Liver , Rats , Rats, Sprague-Dawley , Receptors, Glucocorticoid , Response Elements , Sterol Regulatory Element Binding Protein 1 , Valproic Acid
12.
Anatomy & Cell Biology ; : 274-283, 2018.
Article in English | WPRIM | ID: wpr-718952

ABSTRACT

Hyper-O-GlcNAcylation is a general feature of cancer which contributes to various cancer phenotypes, including cell proliferation and cell growth. Quercetin, a naturally occurring dietary flavonoid, has been reported to reduce the proliferation and growth of cancer. Several reports of the anticancer effect of quercetin have been published, but there is no study regarding its effect on O-GlcNAcylation. The aim of this study was to investigate the anticancer effect of quercetin on HeLa cells and compare this with its effect on HaCaT cells. Cell viability and cell death were determined by MTT and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labelling assays. O-GlcNAcylation of AMP-activated protein kinase (AMPK) was examined by succinylated wheat germ agglutinin pulldown and immunoprecipitation. Immunofluorescence staining was used to detect the immunoreactivitiy of O-linked N-acetylglucosamine transferase (OGT) and sterol regulatory element binding protein 1 (SREBP-1). Quercetin decreased cell proliferation and induced cell death, but its effect on HaCaT cells was lower than that on HeLa cells. O-GlcNAcylation level was higher in HeLa cells than in HaCaT cells. Quercetin decreased the expression of global O-GlcNAcylation and increased AMPK activation by reducing the O-GlcNAcylation of AMPK. AMPK activation due to reduced O-GlcNAcylation of AMPK was confirmed by treatment with 6-diazo-5-oxo-L-norleucine. Our results also demonstrated that quercetin regulated SREBP-1 and its transcriptional targets. Furthermore, immunofluorescence staining showed that quercetin treatment decreased the immunoreactivities of OGT and SREBP-1 in HeLa cells. Our findings demonstrate that quercetin exhibited its anticancer effect by decreasing the O-GlcNAcylation of AMPK. Further studies are needed to explore how quercetin regulates O-GlcNAcylation in cancer.


Subject(s)
Adenosine , AMP-Activated Protein Kinases , Cell Death , Cell Proliferation , Cell Survival , Deoxyuridine , Diazooxonorleucine , Fluorescent Antibody Technique , HeLa Cells , Humans , Immunoprecipitation , Phenotype , Protein Kinases , Quercetin , Sterol Regulatory Element Binding Protein 1 , Transferases , Triticum , Uterine Cervical Neoplasms
13.
Article in English | WPRIM | ID: wpr-718587

ABSTRACT

BACKGROUND/OBJECTIVES: Reducing the number of adipocytes by inducing apoptosis of mature adipocytes as well as suppressing differentiation of preadipocytes plays an important role in preventing obesity. This study examines the anti-adipogenic and pro-apoptotic effect of red pepper seed water extract (RPS) prepared at 4℃ (RPS4) in 3T3-L1 cells. MATERIALS/METHODS: Effect of RPS4 or its fractions on lipid accumulation was determined in 3T3-L1 cells using oil red O (ORO) staining. The expressions of AMP-activated protein kinase (AMPK) and adipogenic associated proteins [peroxisome proliferator-activated receptor-γ (PPAR-γ), CCAAT/enhancer-binding proteins α (C/EBP α), sterol regulatory element binding protein-1c (SREBP-1c), fatty acid synthase (FAS), and acetyl-CoA carboxylase (ACC)] were measured in 3T3-L1 cells treated with RPS4. Apoptosis and the expression of Akt and Bcl-2 family proteins [B-cell lymphoma 2 (Bcl-2), Bcl-2-associated death promoter (Bad), Bcl-2 like protein 4 (Bax), Bal-2 homologous antagonist/killer (Bak)] were measured in mature 3T3-L1 cells treated with RPS4. RESULTS: Treatment of RPS4 (0–75 µg/mL) or its fractions (0–50 µg/mL) for 24 h did not have an apparent cytotoxicity on pre and mature 3T3-L1 cells. RPS4 significantly suppressed differentiation and cellular lipid accumulation by increasing the phosphorylation of AMPK and reducing the expression of PPAR-γ, C/EBP α, SREBP-1c, FAS, and ACC. In addition, all fractions except ethyl acetate fraction significantly suppressed cellular lipid accumulation. RPS4 induced the apoptosis of mature adipocytes by hypophosphorylating Akt, increasing the expression of the pro-apoptotic proteins, Bak, Bax, and Bad, and reducing the expression of the anti-apoptotic proteins, Bcl-2 and p-Bad. CONCLUSIONS: These finding suggest that RPS4 can reduce the numbers as well as the size of adipocytes and might useful for preventing and treating obesity.


Subject(s)
3T3-L1 Cells , Acetyl-CoA Carboxylase , Adipocytes , Adipogenesis , AMP-Activated Protein Kinases , Apoptosis Regulatory Proteins , Apoptosis , Capsicum , Humans , Lipid Metabolism , Lymphoma , Obesity , Phosphorylation , Sterol Regulatory Element Binding Protein 1 , Water
14.
Article in English | WPRIM | ID: wpr-776923

ABSTRACT

Postmenopausal women, who have reduced circulating estrogen levels, are more prone to develop obesity and related metabolic diseases than premenopausal women. The absence of safe and effective treatments for postmenopausal obesity has changed the focus to natural products as alternative remedies. Total salvianolic acids (TSA) are the major water-soluble ingredients of Danshen. Salvianolic acid (SA) is the major constituent of the TSA. Salvianolic acids, including TSA and SA, are widely used in traditional Chinese medicine. In the present study, ovariectomized rats and LO2 cells were used to study the effects of salvianolic acids on body weight gain and hepatic steatosis. Salvianolic acids reduced ovariectomy (OVX)-induced body weight gain, attenuated the expressions of hepatic lipogenic genes, such as sterol regulatory element binding protein (SREBP)1, fatty acid synthase (FAS), and stearoyl-CoA desaturase (SCD)1, and decreased the liver triglyceride (TG) and total cholesterol (TC). For the molecular mechanisms, OVX and high glucose-induced phosphorylation of signal transducer and activator of transcription (STAT)-3 was inhibited by salvianolic acids treatment. In LO2 cells, inhibition of STAT-3 by siRNA attenuated the increased expression of SREBP1 and TG induced by high glucose. Salvianolic acids reduced the upregulation of SREBP1 and TG induced by high glucose in LO2 cells. In conclusion, these findings illustrated that salvianolic acids markedly alleviated the lipid metabolism disorders and protected against the postmenopausal obesity. The underlying mechanism was probably associated with the regulation of STAT-3 signaling.


Subject(s)
Alkenes , Animals , Drugs, Chinese Herbal , Female , Humans , Lipid Metabolism , Liver , Metabolism , Obesity , Drug Therapy , Genetics , Metabolism , Ovariectomy , Polyphenols , Postmenopause , Genetics , Metabolism , Rats , STAT3 Transcription Factor , Genetics , Metabolism , Salvia miltiorrhiza , Chemistry , Signal Transduction , Sterol Regulatory Element Binding Protein 1 , Genetics , Metabolism , Triglycerides , Metabolism
15.
Article in English | WPRIM | ID: wpr-812373

ABSTRACT

Farnesoid X receptor (FXR) is a member of the nuclear receptor superfamily of ligand-activated transcription factors. As a metabolic regulator, FXR plays key roles in bile acid and cholesterol metabolism and lipid and glucose homeostasis. Therefore, FXR is a potential drug target for several metabolic syndromes, especially those related to lipidemia disorders. In the present study, we identified small molecule SIPI-7623, a derivative of an extract from Oriental wormwood (Artemisia capillaris), and found that it specifically upregulated the expression of cholesterol-7-alpha-hydroxylase (CYP7A1), downregulated the expression of sterol-regulatory element-binding protein 1c (SREBP-1c) in the liver, and inhibited the expression of ileal bile acid binding-protein (IBABP) in the ileum of rats. We found that inhibition of FXR by SIPI-7623 decreased the level of cholesterol and triglyceride. SIPI-7623 reduced the levels of cholesterol and triglyceride in in vitro HepG2 cell models, ameliorated diet-induced atherosclerosis, and decreased the serum lipid content on rats and rabbits model of atherosclerosis in vivo. Furthermore, SIPI-7623 decreased the extent of atherosclerotic lesions. Our resutls demonstrated that antagonism of the FXR pathway can be employed as a therapeutic strategy to treat metabolic diseases such as hyperlipidemia and atherosclerosis. In conclusion, SIPI-7623 could be a promising lead compound for development of drugs to treat hyperlipidemia and atherosclerosis.


Subject(s)
Animals , Artemisia , Chemistry , Atherosclerosis , Drug Therapy , Genetics , Metabolism , Cholesterol , Metabolism , Cholesterol 7-alpha-Hydroxylase , Genetics , Metabolism , Drugs, Chinese Herbal , Humans , Hyperlipidemias , Drug Therapy , Genetics , Metabolism , Hypolipidemic Agents , Liver , Metabolism , Male , Rabbits , Rats , Rats, Sprague-Dawley , Receptors, Cytoplasmic and Nuclear , Genetics , Metabolism , Sterol Regulatory Element Binding Protein 1 , Genetics , Metabolism , Triglycerides , Metabolism
16.
Article in English | WPRIM | ID: wpr-812345

ABSTRACT

Postmenopausal women, who have reduced circulating estrogen levels, are more prone to develop obesity and related metabolic diseases than premenopausal women. The absence of safe and effective treatments for postmenopausal obesity has changed the focus to natural products as alternative remedies. Total salvianolic acids (TSA) are the major water-soluble ingredients of Danshen. Salvianolic acid (SA) is the major constituent of the TSA. Salvianolic acids, including TSA and SA, are widely used in traditional Chinese medicine. In the present study, ovariectomized rats and LO2 cells were used to study the effects of salvianolic acids on body weight gain and hepatic steatosis. Salvianolic acids reduced ovariectomy (OVX)-induced body weight gain, attenuated the expressions of hepatic lipogenic genes, such as sterol regulatory element binding protein (SREBP)1, fatty acid synthase (FAS), and stearoyl-CoA desaturase (SCD)1, and decreased the liver triglyceride (TG) and total cholesterol (TC). For the molecular mechanisms, OVX and high glucose-induced phosphorylation of signal transducer and activator of transcription (STAT)-3 was inhibited by salvianolic acids treatment. In LO2 cells, inhibition of STAT-3 by siRNA attenuated the increased expression of SREBP1 and TG induced by high glucose. Salvianolic acids reduced the upregulation of SREBP1 and TG induced by high glucose in LO2 cells. In conclusion, these findings illustrated that salvianolic acids markedly alleviated the lipid metabolism disorders and protected against the postmenopausal obesity. The underlying mechanism was probably associated with the regulation of STAT-3 signaling.


Subject(s)
Alkenes , Animals , Drugs, Chinese Herbal , Female , Humans , Lipid Metabolism , Liver , Metabolism , Obesity , Drug Therapy , Genetics , Metabolism , Ovariectomy , Polyphenols , Postmenopause , Genetics , Metabolism , Rats , STAT3 Transcription Factor , Genetics , Metabolism , Salvia miltiorrhiza , Chemistry , Signal Transduction , Sterol Regulatory Element Binding Protein 1 , Genetics , Metabolism , Triglycerides , Metabolism
17.
Chinese Medical Journal ; (24): 2310-2319, 2018.
Article in English | WPRIM | ID: wpr-690220

ABSTRACT

<p><b>Background</b>A high consumption of fructose leads to hepatic steatosis. About 20-30% of triglycerides are synthesized via de novo lipogenesis. Some studies showed that endoplasmic reticulum stress (ERS) is involved in this process, while others showed that a lipotoxic environment directly influences ER homeostasis. Here, our aim was to investigate the causal relationship between ERS and fatty acid synthesis and the effect of X-box binding protein-1 (XBP-1), one marker of ERS, on hepatic lipid accumulation stimulated by high fructose.</p><p><b>Methods</b>HepG2 cells were incubated with different concentrations of fructose. Upstream regulators of de novo lipogenesis (i.e., carbohydrate response element-binding protein [ChREBP] and sterol regulatory element-binding protein 1c [SREBP-1c]) were measured by polymerase chain reaction and key lipogenic enzymes (acetyl-CoA carboxylase [ACC], fatty acid synthase [FAS], and stearoyl-CoA desaturase-1 [SCD-1]) by Western blotting. The same lipogenesis-associated factors were then evaluated after exposure of HepG2 cells to high fructose followed by the ERS inhibitor tauroursodeoxycholic acid (TUDCA) or the ERS inducer thapsigargin. Finally, the same lipogenesis-associated factors were evaluated in HepG2 cells after XBP-1 upregulation or downregulation through cell transfection.</p><p><b>Results</b>Exposure to high fructose increased triglyceride levels in a dose- and time-dependent manner and significantly increased mRNA levels of SREBP-1c and ChREBP and protein levels of FAS, ACC, and SCD-1, concomitant with XBP-1 conversion to an active spliced form. Lipogenesis-associated factors induced by high fructose were inhibited by TUDCA and induced by thapsigargin. Triglyceride level in XBP-1-deficient group decreased significantly compared with high-fructose group (4.41 ± 0.54 μmol/g vs. 6.52 ± 0.38 μmol/g, P < 0.001), as mRNA expressions of SREBP-1c (2.92 ± 0.46 vs. 5.08 ± 0.41, P < 0.01) and protein levels of FAS (0.53 ± 0.06 vs. 0.85 ± 0.05, P = 0.01), SCD-1 (0.65 ± 0.06 vs. 0.90 ± 0.04, P = 0.04), and ACC (0.38 ± 0.03 vs. 0.95 ± 0.06, P < 0.01) decreased. Conversely, levels of triglyceride (4.22 ± 0.54 μmol/g vs. 2.41 ± 0.35 μmol/g, P < 0.001), mRNA expression of SREBP-1c (2.70 ± 0.33 vs. 1.00 ± 0.00, P < 0.01), and protein expression of SCD-1 (0.93 ± 0.06 vs. 0.26 ± 0.05, P < 0.01), ACC (0.98 ± 0.09 vs. 0.43 ± 0.03, P < 0.01), and FAS (0.90 ± 0.33 vs. 0.71 ± 0.02, P = 0.04) in XBP-1s-upregulated group increased compared with the untransfected group.</p><p><b>Conclusions</b>ERS is associated with de novo lipogenesis, and XBP-1 partially mediates high-fructose-induced lipid accumulation in HepG2 cells through augmentation of de novo lipogenesis.</p>


Subject(s)
Endoplasmic Reticulum Stress , Physiology , Fatty Liver , Fructose , Metabolism , Hep G2 Cells , Humans , Lipogenesis , Physiology , Liver , Sterol Regulatory Element Binding Protein 1 , X-Box Binding Protein 1 , Physiology
18.
Article in English | WPRIM | ID: wpr-740097

ABSTRACT

Obesity is currently one of the most serious public health problems and it can lead to numerous metabolic diseases. Leucrose, d-glucopyranosyl-α-(1-5)-d-fructopyranose, is an isoform of sucrose and it is naturally found in pollen and honey. The aim of this study was to investigate the effect of leucrose on metabolic changes induced by a high-fat diet (HFD) that lead to obesity. C57BL/6 mice were fed a 60% HFD or a HFD with 25% (L25) or 50% (L50) of its total sucrose content replaced with leucrose for 12 weeks. Leucrose supplementation improved fasting blood glucose levels and hepatic triglyceride content. In addition, leucrose supplementation reduced mRNA levels of lipogenesis-related genes, including peroxisome proliferator-activated receptor γ, sterol regulatory element binding protein 1C, and fatty acid synthase in HFD mice. Conversely, mRNA levels of β oxidation-related genes, such as carnitine palmitoyltransferase 1A and acyl CoA oxidase, returned to control levels with leucrose supplementation. Taken together, these results demonstrated the therapeutic potential of leucrose to prevent metabolic abnormalities by mediating regulation of plasma glucose level and hepatic triglyceride accumulation.


Subject(s)
Acyl-CoA Oxidase , Animals , Blood Glucose , Carnitine O-Palmitoyltransferase , Diet, High-Fat , Fasting , Honey , Lipogenesis , Liver , Metabolic Diseases , Mice , Mice, Obese , Negotiating , Obesity , Peroxisomes , Pollen , Public Health , RNA, Messenger , Sterol Regulatory Element Binding Protein 1 , Sucrose , Triglycerides
19.
Article in English | WPRIM | ID: wpr-713309

ABSTRACT

BACKGROUND/AIMS: Hepatic steatosis is caused by an imbalance between free fatty acids (FFAs) uptake, utilization, storage, and disposal. Understanding the molecular mechanisms involved in FFAs accumulation and its modulation could drive the development of potential therapies for Nonalcoholic fatty liver disease. The aim of the current study was to explore the effects of picroside II, a phytoactive found in Picrorhiza kurroa, on fatty acid accumulation vis-à-vis silibinin, a known hepatoprotective phytoactive from Silybum marianum. METHODS: HepG2 cells were loaded with FFAs (oleic acid:palmitic acid/2:1) for 20 hours to mimic hepatic steatosis. The FFAs concentration achieving maximum fat accumulation and minimal cytotoxicity (500 μM) was standardized. HepG2 cells were exposed to the standardized FFAs concentration with and without picroside II pretreatment. RESULTS: Picroside II pretreatment inhibited FFAs-induced lipid accumulation by attenuating the expression of fatty acid transport protein 5, sterol regulatory element binding protein 1 and stearoyl CoA desaturase. Preatreatment with picroside II was also found to decrease the expression of forkhead box protein O1 and phosphoenolpyruvate carboxykinase. CONCLUSIONS: These findings suggest that picroside II effectively attenuated fatty acid accumulation by decreasing FFAs uptake and lipogenesis. Picroside II also decreased the expression of gluconeogenic genes.


Subject(s)
Fatty Acid Transport Proteins , Fatty Acids, Nonesterified , Hep G2 Cells , Lipogenesis , Milk Thistle , Non-alcoholic Fatty Liver Disease , Phosphoenolpyruvate , Picrorhiza , Stearoyl-CoA Desaturase , Sterol Regulatory Element Binding Protein 1
20.
Article in English | WPRIM | ID: wpr-812579

ABSTRACT

Obesity is associated with a number of metabolic abnormalities such as type 2 diabetes and has become a major health problem worldwide. In the present study, we investigated the effects of Epimedium koreanum Nakai (Herba Epimedii, HE) and its main constituent icariin on the adipocyte differentiation in 3T3-L1 preadipocytes. HE extract and icariin significantly reduced lipid accumulation and suppressed the expressions of PPARγ, C/EBPα, and SREBP-1c in 3T3-L1 adipocytes. They also inhibited fatty acid synthase (FAS), acyl-Co A synthase (ACS1), and perilipin. Moreover, HE extract and icariin markedly increased the phosphorylation of AMPK. These results indicated that HE extract and icariin can inhibit the adipocyte differentiation through downregulation of the adipogenic transcription factors, suggesting that HE containing icariin may be used as a potential therapeutic agent in the treatment and prevention of obesity.


Subject(s)
3T3-L1 Cells , Adipocytes , Cell Biology , Metabolism , Adipogenesis , Animals , CCAAT-Enhancer-Binding Protein-alpha , Genetics , Metabolism , Epimedium , Chemistry , Flavonoids , Pharmacology , Lipid Metabolism , Mice , PPAR gamma , Genetics , Metabolism , Plant Extracts , Pharmacology , Sterol Regulatory Element Binding Protein 1 , Genetics , Metabolism
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