1.Anemoside B4 regulates fatty acid metabolism reprogramming in mice with colitis-associated cancer.
Xin YANG ; Jing JIA ; Xin-Xu XIE ; Meng-Qiang WAN ; Yu-Lin FENG ; Ying-Ying LUO ; Hui OUYANG ; Jun YU
China Journal of Chinese Materia Medica 2023;48(9):2325-2333
The study aimed to investigate the effect of anemoside B4(B4) on fatty acid metabolism in mice with colitis-associated cancer(CAC). The CAC model was established by azoxymethane(AOM)/dextran sodium sulfate(DSS) in mice. Mice were randomly divided into a normal group, a model group, and low-, medium-, and high-dose anemoside B4 groups. After the experiment, the length of the mouse colon and the size of the tumor were measured, and the pathological alterations in the mouse colon were observed using hematoxylin-eosin(HE) staining. The slices of the colon tumor were obtained for spatial metabolome analysis to analyze the distribution of fatty acid metabolism-related substances in the tumor. The mRNA levels of SREBP-1, FAS, ACCα, SCD-1, PPARα, ACOX, UCP-2, and CPT-1 were determined by real-time quantitative PCR(RT-qPCR). The results revealed that the model group showed decreased body weight(P<0.05) and colon length(P<0.001), increased number of tumors, and increased pathological score(P<0.01). Spatial metabolome analysis revealed that the content of fatty acids and their derivatives, carnitine, and phospholipid in the colon tumor was increased. RT-qPCR results indicated that fatty acid de novo synthesis and β-oxidation-related genes, such as SREBP-1, FASN, ACCα, SCD-1, ACOX, UCP-2, and CPT-1 mRNA expression levels increased considerably(P<0.05, P<0.001). After anemoside B4 administration, the colon length increased(P<0.01), and the number of tumors decreased in the high-dose anemoside B4 group(P<0.05). Additionally, spatial metabolome analysis showed that anemoside B4 could decrease the content of fatty acids and their derivatives, carnitine, and phospholipids in colon tumors. Meanwhile, anemoside B4 could also down-regulate the expression of FASN, ACCα, SCD-1, PPARα, ACOX, UCP-2, and CPT-1 in the colon(P<0.05, P<0.01, P<0.001). The findings of this study show that anemoside B4 may inhibit CAC via regulating fatty acid metabolism reprogramming.
Mice
;
Animals
;
Sterol Regulatory Element Binding Protein 1
;
Colitis-Associated Neoplasms
;
PPAR alpha/genetics*
;
Colonic Neoplasms/genetics*
;
Colon
;
Azoxymethane
;
RNA, Messenger
;
Dextran Sulfate
;
Colitis/drug therapy*
;
Mice, Inbred C57BL
;
Disease Models, Animal
2.Association of insulin signaling pathway -related gene polymorphisms and gene -gene interactions with MAFLD in obese children.
Xiang XIAO ; Junxia YAN ; Ning'an XU ; Rutong KANG ; Jiayou LUO ; Yan ZHONG
Journal of Central South University(Medical Sciences) 2023;48(4):516-525
OBJECTIVES:
Insulin signaling pathway plays an important role in metabolic associated fatty liver disease (MAFLD), however, the association between polymorphisms of genes related to insulin signaling pathway and MAFLD remains unclear. This study aims to investigate the association between insulin signaling pathway-related gene polymorphisms and gene-gene interactions with MAFLD susceptibility in obese children so as to provide scientific basis for further study of genetic mechanism.
METHODS:
A total of 502 obese children with MAFLD who admitted to Hunan Provincial Children's Hospital from September 2019 to October 2021, were recruited as a case group, and 421 obese children with non-MAFLD admitted during the same period were recruited as a control group. Socio-demographic information, preterm birth history, eating habits, and exercise status of the subjects were collected by inquiry survey, and anthropometric information was collected by physical measurement. At the same time, 2 mL of venous blood was collected to extract DNA, and the polymorphism of insulin signaling pathway-related genes (5 representative candidate genes, 12 variants) was detected. Multivariate Logistic regression analysis was used to investigate the association between insulin signaling pathway-related gene polymorphisms and MAFLD in obese children.
RESULTS:
After adjusting for confounder factors, INS rs3842748 was significantly associated with the risk of MAFLD in obese children in allele, heterozygous, and dominant models [OR and 95% CI 1.749 (1.053 to 2.905), 1.909 (1.115 to 3.267), 1.862 (1.098 to 3.157), all P<0.05]; INS rs3842752 was significantly associated with the risk of MAFLD in obese children in heterozygous and dominant models [OR and 95% CI 1.736 (1.028 to 2.932), 1.700 (1.015 to 2.846), all P<0.05]. NR1H3 rs3758674 was significantly correlated with the risk of MAFLD in obese children in allele model [OR and 95% CI 0.716 (0.514 to 0.997), P<0.05]. SREBP-1c rs2297508 was significantly associated with the risk of MAFLD in obese children in allele and dominant models [OR and 95% CI 0.772 (0.602 to 0.991) and 0.743 (0.557 to 0.991), all P<0.05]. SREBP-1c rs8066560 was significantly associated with the risk of MAFLD in obese children in allele, heterozygous, and dominant models [OR and 95% CI 0.759 (0.589 to 0.980), 0.733 (0.541 to 0.992), 0.727 (0.543 to 0.974), all P<0.05]. NR1H3 rs3758674 mutant C and SREBP-1c rs2297508 mutant G had interaction in the development of MAFLD in obese children [OR and 95% CI 0.407 (0.173 to 0.954), P<0.05].
CONCLUSIONS
The INS, NR1H3, and SREBP-1c gene polymorphisms in the insulin signaling pathway are associated with the susceptibility of MAFLD in obese children, but the functions and mechanisms of these genes need to be further studied.
Child
;
Infant, Newborn
;
Humans
;
Female
;
Pediatric Obesity/genetics*
;
Sterol Regulatory Element Binding Protein 1
;
Premature Birth
;
Non-alcoholic Fatty Liver Disease
;
Signal Transduction/genetics*
;
Insulins
3.Diosgenin alleviates NAFLD induced by a high-fat diet in rats via mTOR/SREBP-1c/HSP60/MCAD/SCAD signaling pathway.
Su-Wen CHEN ; Guo-Liang YIN ; Chao-Yuan SONG ; De-Cheng MENG ; Wen-Fei YU ; Xin ZHANG ; Ya-Nan FENG ; Peng-Peng LIANG ; Feng-Xia ZHANG
China Journal of Chinese Materia Medica 2023;48(19):5304-5314
This study aims to observe the effects of diosgenin on the expression of mammalian target of rapamycin(mTOR), sterol regulatory element-binding protein-1c(SREBP-1c), heat shock protein 60(HSP60), medium-chain acyl-CoA dehydrogenase(MCAD), and short-chain acyl-CoA dehydrogenase(SCAD) in the liver tissue of the rat model of non-alcoholic fatty liver disease(NAFLD) and explore the mechanism of diosgenin in alleviating NAFLD. Forty male SD rats were randomized into five groups: a control group, a model group, low-(150 mg·kg~(-1)·d~(-1)) and high-dose(300 mg·kg~(-1)·d~(-1)) diosgenin groups, and a simvastatin(4 mg·kg~(-1)·d~(-1)) group. The rats in the control group were fed with a normal diet, while those in the other four groups were fed with a high-fat diet. After feeding for 8 weeks, the body weight of rats in the high-fat diet groups increased significantly. After that, the rats were administrated with the corresponding dose of diosgenin or simvastatin by gavage every day for 8 weeks. The levels of triglyceride(TG), total cholesterol(TC), alanine transaminase(ALT), and aspartate transaminase(AST) in the serum were determined by the biochemical method. The levels of TG and TC in the liver were measured by the enzyme method. Oil-red O staining was employed to detect the lipid accumulation, and hematoxylin-eosin(HE) staining to detect the pathological changes in the liver tissue. The mRNA and protein levels of mTOR, SREBP-1c, HSP60, MCAD, and SCAD in the liver tissue of rats were determined by real-time fluorescence quantitative polymerase chain reaction(RT-qPCR) and Western blot, respectively. Compared with the control group, the model group showed increased body weight, food uptake, liver index, TG, TC, ALT, and AST levels in the serum, TG and TC levels in the liver, lipid deposition in the liver, obvious hepatic steatosis, up-regulated mRNA and protein expression levels of mTOR and SREBP-1c, and down-regulated mRNA and protein expression levels of HSP60, MCAD, and SCAD. Compared with the model group, the rats in each treatment group showed obviously decreased body weight, food uptake, liver index, TG, TC, ALT, and AST levels in the serum, TG and TC levels in the liver, lessened lipid deposition in the liver, ameliorated hepatic steatosis, down-regulated mRNA and protein le-vels of mTOR and SREBP-1c, and up-regulated mRNA and protein levels of HSP60, MCAD, and SCAD. The high-dose diosgenin outperformed the low-dose diosgenin and simvastatin. Diosgenin may prevent and treat NAFLD by inhibiting the expression of mTOR and SREBP-1c and promoting the expression of HSP60, MCAD, and SCAD to reduce lipid synthesis, improving mitochondrial function, and promoting fatty acid β oxidation in the liver.
Rats
;
Male
;
Animals
;
Non-alcoholic Fatty Liver Disease/genetics*
;
Sterol Regulatory Element Binding Protein 1/metabolism*
;
Diet, High-Fat/adverse effects*
;
Diosgenin/metabolism*
;
Chaperonin 60/therapeutic use*
;
Rats, Sprague-Dawley
;
Liver
;
Signal Transduction
;
TOR Serine-Threonine Kinases/metabolism*
;
Triglycerides
;
RNA, Messenger/metabolism*
;
Simvastatin/therapeutic use*
;
Body Weight
;
Lipid Metabolism
;
Mammals/metabolism*
4.Berberine mitigates nonalcoholic hepatic steatosis by downregulating SIRT1-FoxO1-SREBP2 pathway for cholesterol synthesis.
Meng-Ya SHAN ; Ying DAI ; Xiao-Dan REN ; Jing ZHENG ; Ke-Bin ZHANG ; Bin CHEN ; Jun YAN ; Zi-Hui XU
Journal of Integrative Medicine 2021;19(6):545-554
OBJECTIVE:
To investigate effects of berberine (BBR) on cholesterol synthesis in HepG2 cells with free fatty acid (FFA)-induced steatosis and to explore the underlying mechanisms.
METHODS:
A steatosis cell model was induced in HepG2 cell line fed with FFA (0.5 mmol/L, oleic acid:palmitic acid = 2:1), and then treated with three concentrations of BBR; cell viability was assessed with cell counting kit-8 assays. Lipid accumulation in cells was observed through oil red O staining and total cholesterol (TC) content was detected by TC assay. The effects of BBR on cholesterol synthesis mediators were assessed by Western blotting and quantitative polymerase chain reaction. In addition, both silent information regulator 1 (SIRT1) and forkhead box transcription factor O1 (FoxO1) inhibitors were employed for validation.
RESULTS:
FFA-induced steatosis was successfully established in HepG2 cells. Lipid accumulation and TC content in BBR groups were significantly lower (P < 0.05, P < 0.01), associated with significantly higher mRNA and protein levels of SIRT1(P < 0.05, P < 0.01), significantly lower sterol regulatory element-binding protein 2 (SREBP2) and 3-hydroxy 3-methylglutaryl-CoA reductase levels (P < 0.05, P < 0.01), as well as higher Acetyl-FoxO1 protein level (P < 0.05, P < 0.01) compared to the FFA only group. Both SIRT1 inhibitor SIRT1-IN-1 and FoxO1 inhibitor AS1842856 blocked the BBR-mediated therapeutic effects. Immunofluorescence showed that the increased SIRT1 expression increased FoxO1 deacetylation, and promoted its nuclear translocation.
CONCLUSION
BBR can mitigate FFA-induced steatosis in HepG2 cells by activating SIRT1-FoxO1-SREBP2 signal pathway. BBR may emerge as a potential drug candidate for treating nonalcoholic hepatic steatosis.
Berberine/pharmacology*
;
Cholesterol
;
Forkhead Box Protein O1/genetics*
;
Humans
;
Non-alcoholic Fatty Liver Disease/drug therapy*
;
Sirtuin 1/genetics*
;
Sterol Regulatory Element Binding Proteins
5.Salvianolic acids improve liver lipid metabolism in ovariectomized rats via blocking STAT-3/SREBP1 signaling.
Juan CHEN ; Jia YUE ; Jiao LIU ; Yun LIU ; Kai-Lin JIAO ; Meng-Ying TENG ; Chun-Yan HU ; Jing ZHEN ; Mao-Xuan WU ; Ming ZHOU ; Zhong LI ; Yuan LI
Chinese Journal of Natural Medicines (English Ed.) 2018;16(11):838-845
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.
Alkenes
;
administration & dosage
;
Animals
;
Drugs, Chinese Herbal
;
administration & dosage
;
Female
;
Humans
;
Lipid Metabolism
;
drug effects
;
Liver
;
drug effects
;
metabolism
;
Obesity
;
drug therapy
;
genetics
;
metabolism
;
Ovariectomy
;
Polyphenols
;
administration & dosage
;
Postmenopause
;
drug effects
;
genetics
;
metabolism
;
Rats
;
STAT3 Transcription Factor
;
genetics
;
metabolism
;
Salvia miltiorrhiza
;
chemistry
;
Signal Transduction
;
drug effects
;
Sterol Regulatory Element Binding Protein 1
;
genetics
;
metabolism
;
Triglycerides
;
metabolism
6.Hypolipidemic effect of SIPI-7623, a derivative of an extract from oriental wormwood, through farnesoid X receptor antagonism.
Yi-Fang DENG ; Xiao-Ling HUANG ; Mei SU ; Peng-Xia YU ; Zhen ZHANG ; Quan-Hai LIU ; Guo-Ping WANG ; Min-Yu LIU
Chinese Journal of Natural Medicines (English Ed.) 2018;16(8):572-579
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.
Animals
;
Artemisia
;
chemistry
;
Atherosclerosis
;
drug therapy
;
genetics
;
metabolism
;
Cholesterol
;
metabolism
;
Cholesterol 7-alpha-Hydroxylase
;
genetics
;
metabolism
;
Drugs, Chinese Herbal
;
administration & dosage
;
Humans
;
Hyperlipidemias
;
drug therapy
;
genetics
;
metabolism
;
Hypolipidemic Agents
;
administration & dosage
;
Liver
;
drug effects
;
metabolism
;
Male
;
Rabbits
;
Rats
;
Rats, Sprague-Dawley
;
Receptors, Cytoplasmic and Nuclear
;
antagonists & inhibitors
;
genetics
;
metabolism
;
Sterol Regulatory Element Binding Protein 1
;
genetics
;
metabolism
;
Triglycerides
;
metabolism
7.Effects of SIRT1 gene knock-out via activation of SREBP2 protein-mediated PI3K/AKT signaling on osteoarthritis in mice.
Fei YU ; Hui ZENG ; Ming LEI ; De-Ming XIAO ; Wei LI ; Hao YUAN ; Jian-Jing LIN
Journal of Huazhong University of Science and Technology (Medical Sciences) 2016;36(5):683-690
This study investigated the effects of SIRT1 gene knock-out on osteoarthritis in mice, and the possible roles of SREBP2 protein and the PI3K/AKT signaling pathway in the effects. Mice were randomly divided into a normal group and a SIRT1 gene knock-out group (6 mice in each group). In these groups, one side of the knee anterior cruciate ligament was traversed, and the ipsilateral medial meniscus was cut to establish an osteoarthritis model of knee joint. The countralateral synovial bursa was cut out, serving as controls. The knee joint specimens were then divided into four groups: SIRT1control group (group A, n=6); SIRT1osteoarthritis group (group B, n=6); SIRT1control group (group C, n=6); SIRT1osteoarthritis group (group D, n=6). HE staining, Masson staining, Safranin O-Fast Green staining and Van Gieson staining were used to observe the morphological changes in the articular cartilage of the knee. Immunohistochemical staining was employed to detect the expression of SIRT1, SREBP2, VEGF, AKT, HMGCR and type II collagen proteins. SA-β-gal staining was utilized to evaluate chondrocyte aging. The results showed clear knee joint cartilage destruction and degeneration in the SIRT1osteoarthritis group. The tidal line was twisted and displaced anteriorly. Type II collagen was destroyed and distributed unevenly. Compared with the SIRT1osteoarthritis group and SIRT1control group, SIRT1 protein expression was not obviously changed in the SIRT1osteoarthritis group (P>0.05), while the expression levels of the SREBP2, VEGF and HMGCR proteins were significantly increased (P<0.05) and the levels of AKT and type II collagen proteins were significantly decreased (P<0.05). SIRT1 gene knock-out may aggravate cartilage degeneration in osteoarthritis by activating the SREBP2 protein-mediated PI3K/AKT signalling pathway, suggesting that SIRT1 gene may play a protective role against osteoarthritis.
Animals
;
Cartilage
;
pathology
;
Chondrocytes
;
metabolism
;
Collagen Type II
;
metabolism
;
Disease Models, Animal
;
Humans
;
Knee Joint
;
metabolism
;
pathology
;
Mice
;
Mice, Knockout
;
Oncogene Protein v-akt
;
genetics
;
Osteoarthritis
;
genetics
;
pathology
;
Phosphatidylinositol 3-Kinases
;
genetics
;
Signal Transduction
;
genetics
;
Sirtuin 1
;
genetics
;
Sterol Regulatory Element Binding Protein 2
;
biosynthesis
;
genetics
;
Vascular Endothelial Growth Factor A
;
biosynthesis
8.Petroleum ether sub-fraction of rosemary extract improves hyperlipidemia and insulin resistance by inhibiting SREBPs.
Zhi-Shen XIE ; Ling-Jun ZHONG ; Xiao-Meng WAN ; Meng-Ning LI ; Hua YANG ; Ping LI ; Xiao-Jun XU
Chinese Journal of Natural Medicines (English Ed.) 2016;14(10):746-756
As a culinary and medicinal herb, rosemary is widely used. The present work aimed to investigate the effects of rosemary extracts on metabolic diseases and the underlying mechanisms of action. Liver cells stably expressing SREBP reporter were used to evaluate the inhibitory effects of different fractions of rosemary extracts on SREBP activity. The obese mice induced by Western-type diet were orally administered with rosemary extracts or vehicle for 7 weeks, the plasma and tissue lipids were analyzed. SREBPs and their target genes were measured by quantitative RT-PCR. We demonstrated that the petroleum ether sub-fraction of rosemary extracts (PER) exhibited the best activity in regulating lipid metabolism by inhibiting SREBPs, while water and n-BuOH sub-fraction showed the SREBPs agonist-effect. After PER treatment, there was a significant reduction of total SREBPs in liver cells. PER not only decreased SREBPs nuclear abundance, but also inhibited their activity, resulting in decreased expression of SREBP-1c and SREBP-2 target genes in vitro and in vivo. Inhibiting SREBPs by PER decreased the total triglycerides and cholesterol contents of the liver cells. In the mice fed with Western-type diet, PER treatment decreased TG, TC, ALT, glucose, and insulin in blood, and improved glucose tolerance and insulin sensitivity. Furthermore, PER treatment also decreased lipid contents in liver, brown adipose tissue, and white adipose tissue. Our results from the present study suggested that petroleum ether fraction of rosemary extracts exhibited the best potential of improving lipid metabolism by inhibiting SREBPs activity.
Alkanes
;
chemistry
;
Animals
;
Cholesterol
;
metabolism
;
Hepatocytes
;
drug effects
;
metabolism
;
Humans
;
Hyperlipidemias
;
drug therapy
;
genetics
;
metabolism
;
Insulin
;
metabolism
;
Insulin Resistance
;
Liver
;
drug effects
;
metabolism
;
Male
;
Mice
;
Mice, Inbred C57BL
;
Petroleum
;
analysis
;
Plant Extracts
;
administration & dosage
;
chemistry
;
isolation & purification
;
Rosmarinus
;
chemistry
;
Sterol Regulatory Element Binding Protein 1
;
genetics
;
metabolism
;
Sterol Regulatory Element Binding Protein 2
;
genetics
;
metabolism
9.Epimedium koreanum Nakai and its main constituent icariin suppress lipid accumulation during adipocyte differentiation of 3T3-L1 preadipocytes.
Yunk-Yung HAN ; Mi-Young SONG ; Min-Sub HWANG ; Ji-Hye HWANG ; Yong-Ki PARK ; Hyo-Won JUNG
Chinese Journal of Natural Medicines (English Ed.) 2016;14(9):671-676
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.
3T3-L1 Cells
;
Adipocytes
;
cytology
;
drug effects
;
metabolism
;
Adipogenesis
;
drug effects
;
Animals
;
CCAAT-Enhancer-Binding Protein-alpha
;
genetics
;
metabolism
;
Epimedium
;
chemistry
;
Flavonoids
;
pharmacology
;
Lipid Metabolism
;
drug effects
;
Mice
;
PPAR gamma
;
genetics
;
metabolism
;
Plant Extracts
;
pharmacology
;
Sterol Regulatory Element Binding Protein 1
;
genetics
;
metabolism
10.Cilostazol inhibits insulin-stimulated expression of sterol regulatory binding protein-1c via inhibition of LXR and Sp1.
Yun A JUNG ; Hee Kyoung KIM ; Kwi Hyun BAE ; Hye Young SEO ; Hye Soon KIM ; Byoung Kuk JANG ; Gwon Soo JUNG ; In Kyu LEE ; Mi Kyung KIM ; Keun Gyu PARK
Experimental & Molecular Medicine 2014;46(1):e73-
Hepatic steatosis is common in obese individuals with hyperinsulinemia and is an important hepatic manifestation of metabolic syndrome. Sterol regulatory binding protein-1c (SREBP-1c) is a master regulator of lipogenic gene expression in the liver. Hyperinsulinemia induces transcription of SREBP-1c via activation of liver X receptor (LXR) and specificity protein 1 (Sp1). Cilostazol is an antiplatelet agent that prevents atherosclerosis and decreases serum triglyceride levels. However, little is known about the effects of cilostazol on hepatic lipogenesis. Here, we examined the role of cilostazol in the regulation of SREBP-1c transcription in the liver. The effects of cilostazol on the expression of SREBP-1c and its target genes in response to insulin or an LXR agonist (T0901317) were examined using real-time RT-PCR and western blot analysis on cultured hepatocytes. To investigate the effect of cilostazol on SREBP-1c at the transcriptional level, transient transfection reporter assays and electrophoretic mobility shift assays (EMSAs) were performed. Cilostazol inhibited insulin-induced and LXR-agonist-induced expression of SREBP-1c and its downstream targets, acetyl-CoA carboxylase and fatty acid synthase, in cultured hepatocytes. Cilostazol also inhibited activation of the SREBP-1c promoter by insulin, T0901317 and Sp1 in a luciferase reporter assay. EMSA analysis showed that cilostazol inhibits SREBP-1c expression by repressing the binding of LXR and Sp1 to the promoter region. These results indicate that cilostazol inhibits insulin-induced hepatic SREBP-1c expression via the inhibition of LXR and Sp1 activity and that cilostazol is a negative regulator of hepatic lipogenesis.
Animals
;
Cells, Cultured
;
Hep G2 Cells
;
Hepatocytes/drug effects/*metabolism
;
Humans
;
Hydrocarbons, Fluorinated/pharmacology
;
Insulin/pharmacology
;
Lipogenesis
;
Mice
;
Mice, Inbred C57BL
;
Orphan Nuclear Receptors/agonists/*metabolism
;
Promoter Regions, Genetic
;
Protein Binding
;
Rats
;
Sp1 Transcription Factor/*metabolism
;
Sterol Regulatory Element Binding Protein 1/genetics/*metabolism
;
Sulfonamides/pharmacology
;
Tetrazoles/*pharmacology

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