Intervention effects and mechanism of Chinese herbal medicine of supplementing Qi and activating blood circulation on chronic intermittent hypoxia composite insulin resistance ApoE~(-/-) mice model / 中国中药杂志

This study aims to observe the intervention effects of Chinese herbal medicine of supplementing Qi and activating blood circulation on chronic intermittent hypoxia(CIH) composite insulin resistance(IR) mediated atherosclerosis(AS) mice model,and to observe the mechanism of SREBP-1 c signaling molecule.IR Apo E-/-mice model was induced by high-fat diet combined with STZ injection.Then the mice were treated with hypoxic animal incubator for 8 h per day and 8 weeks to establish a CIH+IR-ApoE-/-mouse model.Model mice were randomly and averagely divided into normoxic control group(NC),model group(CIH) and SREBPs inhibitor group(betulin),atorvastatin group(WM),TCM low-dose group(TCM-L),TCM middle-dose group(TCM-M) and TCM high-dose group(TCM-H) group.Chinese herbal medicine of supplementing Qi and activating blood circulation including ginsenosides combined with ligustrazine(TMP) were used as intervention drugs.The study observed the effect of drugs on IR,serum lipid,inflammation,stress,AS and SREBP-1 c related molecules.The results showed that fasting blood glucose in TCM-H group decreased compared with other experimental groups(P<0.05).HDL-C level in betulin group,WM group,TCM-H group was higher than that in CIH group(P<0.05).LDL-C level in TCM-M group,TCM-H group is lower than that in CIH group(P<0.05).The level of CRP in CIH group was higher than that in other groups(P<0.05).The level of SOD in TCM-H group was higher than that in CIH group(P<0.05).NC group and CIH group showed obvious AS aortic plaque,while betulin group,WM group,TCM-H group showed reduction in AS plaque(P<0.05).For descending aorta,AS plaque in CIH group was multiple and large,while less and smaller in WM group and TCM-H(P<0.05).The expression of SREBP-1 c and FAS in aorta and skeletal muscle in TCM-H group was lower than that in CIH group(P<0.05).In aorta,the expression of TNF-α and CD106(VCAM-1) was lower in TCM-H group than that in CIH group(P<0.05).In aorta,skeletal muscle and liver,the level of p-IRS-1 in TCM-H group was significantly higher than that in CIH group(P<0.05).In aorta and liver,the expression of HIF-1α in TCM-H group was lower than that in CIH group(P<0.05).The study demonstrated that combination ginsenosides with TMP could improve IR and serum lipid level and inhibit inflammation and oxidative stress as well as ultimately alleviate AS to some extent.And the mechanism of its interventional effects might be related to the inhibition of CIH-induced upregulation of SREBP-1 c related molecules.

RASAL1 induces to downregulate the SCD1, leading to suppression of cell proliferation in colon cancer via LXRα/SREBP1c pathway

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.

Effect of Eletroacupuncture Intervention on Insulin Resistance, Lipid Metabolic Disorder and Expression of Hepatic SREBP-1 c and Fatty Acid Synthase Proteins in Rats with Hyperlipidemia / 针刺研究

OBJECTIVE: To observe the effect of electroacupuncture(EA) of "Fenglong" (ST 40) and "Sanyinjiao" (SP 6) on lipid metabolic disorder, insulin resistance (IR) and expression of sterol regulatory element blinding protein-1 (SREBP-1) c and fatty acid synthase (FAS) proteins in the liver tissue in hyperlipidemia rats with IR, so as to reveal its mechanisms underlying improvement of IR. METHODS: Forty male SD rats were randomly divided into blank control, model, medication and EA groups (n＝8 in each group). The IR model was established by feeding the rat with high-fat diet. Rats of the medication group were treated by intragastric administration of pioglitazone (10 mL/kg). For rats of the EA group, EA (2 Hz/100 Hz，1 mA) was applied to bilateral ST 40 and SP 6, once daily for 14 days. The insulin sensitivity index (ISI) was assessed by calculating 60－120 min glucose infusion rate (GIR 60－120) with euglycemic hyperinsulinemic clamp in reference to Kraegen's and colleagues' methods. Fasting blood samples (10 mL) were collected and analyzed for fasting blood glucose (FBG) using enzyme method, serum fasting insulin(FINS) using ELISA, free fatty acid(FFA) using spectrophotometry, and total triglyceride(TG) and total cholesterol(TC) employing glycerine phosphate oxidase peroxidase (GPO-PAP) assay, low density lipoprotein(LDL), high density lipoprotein(HDL) levels using combined filiter paper activity and lipase activity methods, respectively. The IR level was assessed by calculating homeostatic model assessment of insulin resistance (HOMA-IR) using the formula (FBG×FINS)/22.5. The expression levels of SREBP-1 c and FAS proteins in the liver tissue were detected by Western blot. RESULTS: Following modeling, the GIR 60－120 and serum HDL were significantly decreased(P0.05). CONCLUSION: EA intervention is able to improve the disorder of lipid metabolism of IR rats, which may be associated with its effects in reducing the expression of SREBP-1 c and FAS proteins and in lowering the synthesis of fatty acid.

Protective effects of N-acetyl-L-cysteine against binge drinking-induced fatty liver in mice / 中华劳动卫生职业病杂志

Objective@#To investigate the roles of N-acetyl-L-cysteine (NAC) against binge drinking-induced fatty liver in mice.@*Methods@#SPF male C57BL/6 mice were randomly divided into 3 groups, i.e. control group, model group, and NAC/ethanol group (n=10). Mice in model and NAC/ethanol groups were exposed to 3 doses of ethanol (6 g/kg bw) to induced fatty liver, while mice in control group received equal volume and equal energy of maltodextrin solution. NAC was administered to mice at 1 h before ethanol exposure (100 mg/kg bw, i.p.). The mice were sacrificed at 6 h after the last ethanol exposure. The liver and epididymal adipose tissues were collected. Histopathological examination and biochemical assay kit were used to evaluate the fat accumulation, while Western-blot was performed to detect the protein levels of some key factors involved in fat metabolism in liver and adipose tissues.@*Results@#Compored with control group mice, the liver index and liver weight were significantly increased compared with model group, the liver index and TG level in NAC/ethanol group mice were all significantly decreased (P<0.05). Histological examination showed NAC effectively suppressed binge drinking-induced fat accumulation in mice liver. In addition, NAC had no significant effects on the protein levels of peroxisome proliferator-activated receptor-α (PPAR-α), Acy-CoA oxidase (ACOX), sterol regulatory element binding protein 1 c (SREBP-1c) and fatty acid synthase (FAS). Furthermore, the protein levels of hormone sensitive lipase (HSL) did not significantly differ among 3 groups, whereas NAC prevented binge drinking-induced increase of HSL phosphorylation at ser563 and ser660.@*Conclusion@#NAC could effectively attenuate binge drinking-induced fatty liver, which might be associated with the inhibition of lipid mobilization by suppressing the phosphorylation of HSL.

Effect of transforming growth factor-β1 on HBV replication and antigen synthesis in HepG2.2.15 cells with steatosis / 中华肝脏病杂志

Objective@#To investigate the effect of transforming growth factor-β1 (TGF-β1) on HBV replication and protein expression in HepG2.2.15 cells with steatosis, as well as the association of TGF-β1 with suppressor of cytokine signaling-3 (SOCS-3) mRNA and sterol regulatory element-binding protein-1c (SREBP-1c) mRNA during the steatosis of HepG2.2.15 cells.@*Methods@#The cells were divided into HepG2/HepG2.2.15 cell control groups (C1/C2 groups) and HepG2/HepG2.2.15 cell steatosis groups (F1/F2 groups). 5 ng/ml TGF-β1 was added to the two cell systems for intervention to establish TGF-β1 intervention groups (T1/T2 groups) and steatosis+TGF-β1 intervention groups (TF1/TF2 groups). A time-resolved fluorescence analyzer was used to measure HBsAg and HBeAg, and quantitative real-time PCR was used to measure HBV DNA, SOCS-3 mRNA, and SREBP-1 mRNA. A one-way analysis of variance and a factorial analysis were used for the statistical analysis of data.@*Results@#TGF-β1 significantly reduced the level of HBeAg in C2 group (P = 0.034) and the levels of HBsAg (P < 0.001) and HBeAg (P = 0.004) in F2 group. There was an interaction between steatosis and TGF-β1 in inhibiting HBsAg. In addition, TGF-β1 significantly reduced the mRNA expression of SOCS-3 in C1, F1, C2, and F2 groups (P < 0.05) and significantly increased the mRNA expression of SREBP-1c in C1, F1, C2, and F2 groups (P < 0.05), suggesting that there was an interaction between steatosis and TGF-β1 in downregulating the mRNA expression of SOCS-3 and upregulating the mRNA expression of SREBP-1c.@*Conclusion@#TGF-β1 does not affect HBV duplication in HepG2.2.15 cells and can inhibit the expression of HBsAg and HBeAg. TGF-β1 can downregulate the mRNA expression of SOCS-3 and upregulate the mRNA expression of SREBP-1c.

Differential regulation of SREBP 1 c/cm on transcriptional activity and expression of PERK promoter / 基础医学与临床

Objective To investigate the effect of sterol regulating element binding protein (SREBP1c) and its ac-tive form (SREBP1cm) on human protein kinase R-like endoplasmic reticulum kinase (PERK).Methods Re-porter victors of PERK promoter and its truncations were constructed with pGL 3-basic and co-transfected with internal reference pRL-SV40 into cell and luciferase activity was detected .pcDNA3.1 ( -)-SREBP1c or pcDNA3.1 ( -)-SREBP1cm was co-transfected with PERK promoter transcriptional activity core regions and the detection of dual -lu-ciferase reporter gene was used to analyze the regulation of SREBP 1c/1cm on PERK promoter transcriptional activity . The expression level of PERK mRNA and protein were detected by RT-PCR and Western blot .Results PERK pro-moter and truncations were successfully constructed into pGL 3-basic, and PERK promoter core area of transcription-al activity had determined;Dual-luciferase report gene showed that SREBP 1c inhibited PERK promoter transcrip-tional activity and SREBP1cm promoted PERK promoter transcriptional activity .RT-PCR and Western blot showed that SREBP1c decreased PERK mRNA and protein expression , but SREBP1cm increased PERK mRNA and protein expression, which was consistent with the detection of dual-luciferase report gene .Conclusions SREBP1c and SREBP1cm have a opposite regulation effect on PERK promoter transcriptional activity and its expression .

Changes of suppressors of cytokine signaling-3 and sterol regulatory element binding proteins-1c pathway in steatosis HepG2/HepG2.2.15 cells / 中华传染病杂志

Objective To investigate the effects of HepG2 and HepG2.2.15 cells steatosis on the mRNA and protein expressions of suppressors of cytokine signaling-3(SOCS-3) and sterol regulatory element binding proteins (SREBP-1c).Methods The cell model of chronic hepatitis B (CHB) combined with nonalcoholic fatty liver disease (NAFLD) was successfully constructed using an oleic acid-induced HepG2 and HepG2.2.15 cells steatosis.Cells were divided into HepG2 cell control group (HepG2 cell control group), HepG2.2.15 cell control group (HepG2.2.15 cell control group), HepG2 cell steatosis group (HepG2 cell steatosis group) and HepG2.2.15 cell steatosis group (HepG2.2.15 cell steatosis group).The expression levels of SOCS-3 and SREBP-1c mRNA were detected by real-time quantitative polymerase chain reaction (PCR).Changes in protein expressions of SOCS-3 and SREBP-1c were measured by western blot.Results SOCS-3 mRNA expression level in HepG2.2.15 cell control group was significantly lower than that in HepG2 cell control group (P<0.01).The level in HepG2 cell steatosis group was also significantly lower than that in HepG2 cell control group (P<0.01).However, the level of SOCS-3 mRNA in HepG2.2.15 cell steatosis group was lower than HepG2.2.15 cell control group with no statistical significance (P=0.173).There was interaction between cells and steatosis (F=25.547, P<0.01).The expression of SREBP-1c mRNA in HepG2.2.15 cell control group was significantly lower than that in HepG2 cell control group (P<0.01), and was significantly higher in HepG2.2.15 cell steatosis group than that in HepG2.2.15 cell control group (P<0.01).There was no significant difference between HepG2 cell steatosis group and HepG2 cell control group (P=1.000).There was interaction between cells and steatosis (F=5.04, P<0.05).Western blot analysis showed that protein levels of SOCS-3 and SREBP-1c in steatosis cells at 48 h and 72 h were significantly higher than those in non-alcoholic steatosis cells.Conclusions Protein expressions of SOCS-3 and SREBP-1c are up-regulated in both steatosis groups.Factorial analysis shows that there is interaction between cells and steatosis.HBV gene could inhibit SOCS-3 mRNA expression and promote the expression of SREBP-1c mRNA in steatosis cells.

Telmisartan improves insulin resistance in the rats with nonalcoholic steatohepatitis by SOCS-3/SREBP-1c pathway / 中国实验动物学报

Objective To evaluate the effects of telmisartan by SOCS-3/SREBP-1c pathway and its efficacy of improving insulin resistance (IR) in rats with high-fat diet-induced nonalcoholic steatohepatitis (NASH).Methods A total of 70 SD male rats were assigned randomly into 3 groups: A (normal control,20 rats,basic diet),B (model control,30 rats,high-fat diet) and C (treatment with telmisartan,20 rats,high-fat diet).After the IR-NASH model was made successfully,proved by 10 rats randomly from the group B with euglycemic hyperinsulinemic clamp technique (EHCT) and liver histology,the rats in the group C were intragastrically administrated telmisartan (5 mg/kg/d) for 4 weeks,and then all rats were tested with EHCT and sacrificed to test the blood chemistry,interleukin-6,homeostasis model assessment of insulin resistance,hepatic pathological analysis,and semiquantitative RT-PCR for determining SOCS-3 and SREBP-1c mRNA.Results Rats with high-fat diet developed steatohepatitis and insulin resistance at the 12th week and had more weight gain and higher liver index at the 16th week.IL-6,SOCS-3 and SREBP-1c mRNA expressions in the group B were up-regulated obviously,and each was positively correlated with the velocities of glucose infusion rates at 60~120 min.Blood chemistry and pathological observation in the group C were all improved;both SOCS-3 and SREBP-1c mRNA were down-regulated,and each negatively correlated with VGIR60-120,while serum IL-6 stayed at a high level.Conclusions Telmisartan can remarkably improve hepatic function and insulin resistance in rats with IR-NASH,the mechanisms of which would not be by path of reducing the secretion of IL-6,but by down-regulating the expressions of SOCS-3 and SREBP-1c mRNA.

Metformin ameliorates PA-induced skeletal muscle insulin resistance by suppressing SREBP-1c / 中国药理学通报

Aim Metformin has been the first-line oral agent for the treatment of type 2 diabetes. The results from preliminary studies suggested that sterol regulatory element binding protein-1c( SREBP-1c) inhibited the transcription of insulin receptor substrate-1 ( IRS-1), which plays a key role in PA-induced skeletal muscle insulin resistance. In the current study, we investiga-ted the role and mechanism of SREBP-1c in metformin ameliorating PA-induced skeletal muscle insulin resist-ance. Methods L6 cells were treated with metformin (1,10 mmol·L - 1 ) for 24h in 500 μmol·L - 1 PA-in-duced insulin-resistant state and then harvested for pro-tein and glucose uptake assay. Glucose uptake was performed by 2-NBDG method. The protein expression of SREBP-1c, FAS, p-IRS-1 ( Tyr608 / 612), IRS-1, p-AKT ( Ser473 ) and AKT was detected by western blot. The effects of metformin on SREBP-1c and IRS-1 gene transcription were assessed by a dual-luciferase reporter assay. CHIP assay was performed to examine the binding of SREBP-1c protein to the IRS-1 promoter region by metformin treatment. Results PA treatment decreased glucose uptake in L6 myotubes. The protein expression of SREBP-1c and its downstream molecule FAS was increased significantly after exposure to PA. By contrast, the proteins related to insulin signaling pathway including IRS-1, p-IRS-1( Tyr608 / 612) and p-AKT ( Ser473) / AKT were decreased significantly. Metformin increased glucose uptake in a dose-depend-ent manner compared to PA-cultured L6 cells. The SREBP-1c and FAS protein levels were decreased by metformin treatment. Correspondingly, p-IRS-1 (Tyr608 / 612), IRS-1, p-AKT(Ser473) / AKT protein levels were increased significantly. The results from dual-luciferase reporter assay indicated metformin sup-pressed SREBP-1c promoter activity and enhanced IRS-1 promoter. The results from CHIP assay showed that metformin decreased binding of SREBP-1c protein to the IRS-1 promoter region (about 30% ). Conclu-sion Metformin can improve PA-induced muscular in-sulin resistance by suppressing SREBP-1c.

Curcuma oil ameliorates insulin resistance & associated thrombotic complications in hamster & rat.

Background & objectives: Curcuma oil (C. oil) isolated from turmeric (Curcuma longa L.) has been shown to have neuro-protective, anti-cancer, antioxidant and anti-hyperlipidaemic effects in experimental animal models. However, its effect in insulin resistant animals remains unclear. The present study was carried out to investigate the disease modifying potential and underlying mechanisms of the C. oil in animal models of diet induced insulin resistance and associated thrombotic complications. Methods: Male Golden Syrian hamsters on high fructose diet (HFr) for 12 wk were treated orally with vehicle, fenofibrate (30 mg/kg) or C. oil (300 mg/kg) in the last four weeks. Wistar rats fed HFr for 12 wk were treated orally with C. oil (300 mg/kg) in the last two weeks. To examine the protective effect of C. oil, blood glucose, serum insulin, platelet aggregation, thrombosis and inflammatory markers were assessed in these animals. Results: Animals fed with HFr diet for 12 wk demonstrated hyperlipidaemia, hyperglycaemia, hyperinsulinaemia, alteration in insulin sensitivity indices, increased lipid peroxidation, inflammation, endothelial dysfunction, platelet free radical generation, tyrosine phosphorylation, aggregation, adhesion and intravascular thrombosis. Curcuma oil treatment for the last four weeks in hamsters ameliorated HFr-induced hyperlipidaemia, hyperglycaemia, insulin resistance, oxidative stress, inflammation, endothelial dysfunction, platelet activation, and thrombosis. In HFr fed hamsters, the effect of C. oil at 300 mg/kg was comparable with the standard drug fenofibrate. Curcuma oil treatment in the last two weeks in rats ameliorated HFr-induced hyperglycaemia and hyperinsulinaemia by modulating hepatic expression of sterol regulatory element binding protein 1c (SREBP-1c), peroxisome proliferator-activated receptor-gamma co-activator 1 (PGC-1)α and PGC-1β genes known to be involved in lipid and glucose metabolism. Interpretation & conclusions: High fructose feeding to rats and hamsters led to the development of insulin resistance, hyperglycaemia, endothelial dysfunction and oxidative stress. C. oil prevented development of thrombotic complications associated with insulin resistance perhaps by modulating genes involved in lipid and glucose metabolism. Further studies are required to confirm these findings.

Prophylactic efficacy and possible mechanisms of oligosaccharides based standardized fenugreek seed extract on high-fat diet-induced insulin resistance in C57BL/6 mice.

The present work was aimed to study the efficacy and possible mechanism of oligosaccharides based standardized fenugreek seed extract (SFSE-OS) on high-fat diet (HFD)-induced insulin resistance in male C57BL/6 mice. The effects of 12 weeks of oral administration of SFSE-OS (30, 60 and 100 mg/kg, twice daily) were evaluated on HFD fed mice for anthropomorphic, glycemic, gene expression related and histopathological parameters. Separate groups of mice with vehicle co-administered with HFD and low-fat diet (LFD) were maintained as HFD control and LFD control respectively. Twelve weeks of SFSE-OS (60 and 100 mg/kg, p.o.) administration showed significant prophylactic effects on HFD induced insulin resistance in terms of body weight, plasma glucose and insulin levels, glycated hemoglobin, insulin resistance (IR), area under the curve (AUC) of plasma glucose during oral glucose tolerance and intraperitoneal insulin tolerance. Furthermore, HFDinduced mRNA expression changes in adipose tissue, liver and skeletal muscle were prevented by SFSE-OS coadministration. Histology of sections of the pancreas showed the normal architecture in all groups of mice. SFSE-OS showed promising efficacy in prevention of HFD-induced insulin resistance through modulation of Glut-2, Glut-4, IRS-2 and SREBP-1c expression.

The effects of black garlic (Allium satvium) extracts on lipid metabolism in rats fed a high fat diet

BACKGROUD/OBEJECTIVES: The mechanism of how black garlic effects lipid metabolism remains unsolved. Therefore, the objectives of this study were to determine the effects of black garlic on lipid profiles and the expression of related genes in rats fed a high fat diet. MATERIALS/METHODS: Thirty-two male Sqrague-Dawley rats aged 4 weeks were randomly divided into four groups (n=8) and fed the following diets for 5 weeks: normal food diet, (NF); a high-fat diet (HF); and a high-fat diet + 0.5% or 1.5% black garlic extract (HFBG0.5 or HFBG1.5). Body weights and blood biochemical parameters, including lipid profiles, and expressions of genes related to lipid metabolism were determined. RESULTS: Significant differences were observed in the final weights between the HFBG1.5 and HF groups. All blood biochemical parameters measured in the HFBG1.5 group showed significantly lower values than those in the HF group. Significant improvements of the plasama lipid profiles as well as fecal excretions of total lipids and triglyceride (TG) were also observed in the HFBG1.5 group, when compared to the HF diet group. There were significant differences in the levels of mRNA of sterol regulatory element binding protein-1c (SREBP-1c), acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), and glucose-6-phosphate dehydrogenase (G6PDH) in the HFBG1.5 group compared to the HF group. In addition, the hepatic expression of (HMG-CoA) reductase and Acyl-CoA cholesterol acyltransferase (ACAT) mRNA was also significantly lower than the HF group. CONCLUSIONS: Consumption of black garlic extract lowers SREBP-1C mRNA expression, which causes downregulation of lipid and cholestrol metahbolism. As a result, the blood levels of total lipids, TG, and cholesterol were decreased.

Effects of Soothing Liver and Invigorating Spleen Recipe on Lipid Metabolism Disorders in Kupffer Cells of NAFLD Rats by LXRα/SREBP-1c Signal Pathway / 中草药·英文版

Objective: To investigate the mechanism of lipid metabolism disorders in Kupffer cells (KCs) of non-alcoholic fatty liver disease (NAFLD) rats mediated by LXRα-SREBP-1c pathway and the interference of soothing liver and invigorating spleen recipe (SLISR) on it. Methods: SD male rats were randomly divided into five groups: normal, model, soothing liver recipe (SLR), invigorating spleen recipe (ISR), and soothing liver and invigorating spleen recipe (SLISR) groups. The rats in treatment groups were administered for 8 weeks. The liver tissue was stained with H&E and oil red O. The levels of hepatic lipid and blood lipid were measured by biochemical analyzer. KCs were isolated from the livers of rats to evaluate the expression of LXRα, SREBP-1C, and FAS mRNA by real-time fluorescence quantitative PCR tests; LXRα, SREBP-1C, and FAS proteins were measured by Western blotting. Results: The H&E and oil red O staining results showed that the model rats successfully reproduced typical pathogenetic and histopathological features of NAFLD. The levels of hepatic lipid and blood lipid in the model rats were dramatically increased. Compared with the model group, the values of hepatic lipid and blood lipid in the treatment groups were significantly ameliorated (P < 0.05, 0.01). The yields of purified KCs from each rat were 2×107-3×107. The viability of KCs was higher than 95%, with the purity over 90.18%. Compared with the model group, the expression of LXRα, SREBP-1C, and FAS mRNA and proteins was decreased in all treatment groups, especially in the SLR group (P < 0.05). Conclusion: SLISR may protect liver against injury included by lipid metabolism disorders in KCs through LXRα/SREBP-1c signaling pathway, which may be an important mechanism for the prevention and treatment of NAFLD.

Cilostazol inhibits insulin-stimulated expression of sterol regulatory binding protein-1c via inhibition of LXR and Sp1

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.

Triglyceride disorder biomakers in hyperlipidemic hamsters / 中国药理学通报

Aim To establish hyperlipidemic model and study the molecular mechanism of triglyceride (TG)disorder in hamsters.Methods The male ham-sters were randomly divided to control group fed with standard diet and model group fed with high-fat diet, both of the groups had been fed with diet for 4 weeks. The levels of serum TG,TC,LDL-C,FFA were detec-ted at the end of 2nd and 4th week.The hepatic TG, TC,LPL activity were detected by enzymatic method at the end of 4th week.The molecular mechanism was tested by real-time PCR.Meanwhile the effect of posi-tive drug fenofibrate on the model of hyperlipidemia in hamsters was investigated.Results Compared with the control,the serum levels of TG,TC,LDL-C,FFA in the model group increased 2.57,1.93,2.49,1.25 times at the end of2nd week,and 3.93,1.90,2.27, 2.29 times at the end of 4th week,respectively.The positive drug significantly decreased the concentrations of serum TG and FFA. The mechanism research showed that the hepatic AMPK,PPARα,CPT-1 mRNA decreased in hamsters fed with high-fat diet,and the SREBP-1 c,ACC,SCD-1 ,AGPAT2,DGAT2 mRNA ex-pressions increased.The hepatic ApoB mRNA expres-sion was up-regulated while the MTTP and LPL mRNA expressions were down-regulated slightly.LPL activity significantly decreased in model hamsters compared with the control.The alternations of these enzymes and receptors were the critical factors for TG disorder. Conclusion The hamsters fed with high-fat diet for 4 weeks can form a good hyperlipemic model with HTG feature.AMPK,SREBP-1 c,ACC,SCD-1 ,DGAT2,AG-PAT2,PPARα,CPT-1 and LPL are not only the main mechanisms of TG disorder,but also the biomarkers of hypotriglyceridemic drugs.

The effect of fucoxanthin rich power on the lipid metabolism in rats with a high fat diet

This study determined the effects of fucoxanthin on gene expressions related to lipid metabolism in rats with a high-fat diet. Rats were fed with normal fat diet (NF, 7% fat) group, high fat diet group (HF, 20% fat), and high fat with 0.2% fucoxanthin diet group (HF+Fxn) for 4 weeks. Body weight changes and lipid profiles in plasma, liver, and feces were determined. The mRNA expressions of transcriptional factors such as sterol regulatory element binding protein (SREBP)-1c, Carnitine palmitoyltransferase-1 (CPT1), Cholesterol 7alpha-hydroxylase1 (CYP7A1) as well as mRNA expression of several lipogenic enzymes were determined. Fucoxanthin supplements significantly increased plasma high density lipoprotein (HDL) concentration (P < 0.05). The hepatic total lipids, total cholesterols, and triglycerides were significantly decreased while the fecal excretions of total lipids, cholesterol, and triglycerides were significantly increased in HF+Fxn group (P < 0.05). The mRNA expression of hepatic Acetyl-CoA carboxylase (ACC), Fatty acid synthase (FAS), and Glucose-6-phosphate dehydrogenase (G6PDH) as well as SREBP-1C were significantly lower in HF+Fxn group compared to the HF group (P < 0.05). The hepatic mRNA expression of Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) and Acyl-CoA cholesterol acyltransferase (ACAT) were significantly low while lecithin-cholesterol acyltransferase (LCAT) was significantly high in the HF+Fxn group (P < 0.05). There was significant increase in mRNA expression of CPT1 and CYP7A1 in the HF+Fxn group, compared to the HF group (P < 0.05). In conclusion, consumption of fucoxanthin is thought to be effective in improving lipid and cholesterol metabolism in rats with a high fat diet.

Anti-diabetic Activity of Zhenqing Recipe and Ligustri Lucidi Fructus in Type 2 Diabetic Rats / 中草药·英文版

Objective To investigate the influence of Zhenqing Recipe(ZQR)and Ligustri Lucidi Fructus(LLF)on diabetic rats and its possible mechanism.Methods The model of type 2 diabetic rats was established by feeding a high-sucrose-high-fat diet and injecting a low dose of Streptozotocin in Wistar rats.The model rats were randomly divided into three groups: diabetic model,ZQR-treated,and LLF-treated groups for 8-weeks treatment.The normal Wistar rats were as a normal control group.Results The level of fasting blood glucose in ZQR and LLF groups was decreased compared with model group(P < 0.01,0.05,respectively).Both ZQR and LLF markedly reduced serum triglycerides(P < 0.01,0.05,respectively),and increased the insulin sensitivity index(P < 0.05).Histopathology revealed that ZQR and LLF reduced pancreatic damage.Immunohistochemistry evaluation showed that the percentage of insulin positive cells in pancreatic island was higher than model group(P < 0.01,0.05,respectively).The mRNA and protein expression of SREBP-1c in pancreas were significantly decreased in ZQR and FLL group(P < 0.01).Conclusion ZQR has therapeutic effect on type 2 diabetes,it ameliorates the histopathologlcal changes of pancreas,protects β cells,improves insulin resistance,and attenuates the expression of SREBP-1c.This study also provides the anti-diabetic evidence of FLL even its effects are weaker than ZQR.

Rosuvastatina, resistência à insulina, adiposidade, inflamação e esteatose hepática em camundongos alimentados com dieta hiperlipídica / Beneficial effects of rosuvastatin on insulin resistance, adiposity, inflammatory markers and non-alcoholic fatty liver disease in mice fed a high-fat diet

O estudo teve como objetivo avaliar os efeitos da rosuvastatina (ST) e darosiglitazona sobre a resistência à insulina (RI), morfologia do fígado e do tecido adiposo em camundongos alimentados com dieta hiperlipídica (HF). O tratamento com rosuvastatina resultou em uma acentuada melhoria na sensibilidade à insulina caracterizada pela melhor depuração da glicose durante o teste de tolerância à insulina e uma redução do índice HOMA-IR em 70% (P = 0,0008). O grupo tratado com rosuvastatina apresentou redução no ganho massa corporal (-8%, P <0,01) e menor depósito de gordura visceral (-60%, P <0,01) em comparação com o grupo HF não tratado. Em comparação com camundongos HF, animais do grupo HF+ST reduziram significativamente a massa hepática e a esteatose hepática (-6%; P <0,05% e -21; P <0,01, respectivamente). O grupo HF+ST, reduziu os níveis de triglicerídeos hepáticos em 58% comparado com o grupo HF (P <0,01). Além disso, a expressão de SREBP-1c (proteína 1c ligadora do elemento regulado por esteróis) foi reduzido em 50% no fígado dos animais HF + ST (P <0,01) em comparação com o grupo HF. Os níveis de resistina foram menores no grupo HF + ST comparado com o grupo HF (44% a menos, P <0,01). Em conclusão, demonstramos que camundongos alimentados com dieta HF tratados com rosuvastatina melhoram a sensibilidade à insulina, com redução da esteatose hepática. Além disso, ST reduziu o ganho de massa corporal, melhorou os níveis circulantes de colesterol e triglicerídeo plasmático, com menor conteúdo de hepático de triglicerídeo, que foi concomitante com menor resistina e aumento da adiponectina...

The study aimed to evaluate the effects of rosuvastatin (ST) and rosiglitazone on insulin resistance (IR) and liver and adipose tissue morphologies in mice fed a high-fat (HF) diet. Our data show that treatment with rosuvastatin resulted in a marked improvement in insulin sensitivity characterised by enhanced glucose clearance during insulin tolerance and a decrease in the HOMA-IR index level by 70% (P=0.0008). The group of mice treated with rosuvastatin exhibited reduced body mass gain (-8%; P<0.01) and visceral fat pad thickness (-60%; P<0.01)compared with the untreated HF group. In comparison with HF mice, HF+ST mice showed a significant reduction in hepatomegaly and liver steatosis (-6%; P<0.05 and -21%; P<0.01, respectively). In HF+ST mice, the hepatictriglyceride levels were reduced by 58% compared with the HF group (P <0.01). In addition, the expression of SREBP-1c (sterol regulatory element-binding protein) was decreased by 50% in the livers of HF+ST mice (P<0.01) compared with the HF mice. The levels of resistin were lower in the HF+ST group compared with the HF group (44% less, P< 0.01). In conclusion, we demonstrated that rosuvastatin-treated mice fed HF has been improving in insulin sensitivity, with decreased steatosis found in HF mice. Furthermore, ST reduced body mass gain, improved the circulating levels of plasma cholesterol and triglycerides and reduced hepatic triglycerides, which was concomitant with lower resistin and increased total adiponectin...

The Liver Lipogenic Gene Expression of Animal Model of Phlegm and Dampness Syndrome / 国际中医中药杂志

Objective To observe The liver lipogenic gene expression of animal model of phlegm and dampness syndrome. Methods According to the theory "Obese people have much more phlegm and dampness", the animal model of phlegm and dampness was built by high fat feeding. After 10 weeks' high fat feeding, we examined liver HE slice, the level of lipids in the normal and model group rats .The liver lipogenic gene expression including LXRα, SREBP-1c, and FAS were detected by fluorescence real time quantative PCR. Results Compared with that of the normal group rat, there was increasing lipids both in serum and liver in the model rats. There was typical appearance of fatty accumulation in the liver cells examined by liver HE staining. The expression of SREBP-Ic and FAS was much higher in phlegm and dampness group than that in the normal group, although there was no difference in the expression of LXRα. Conclusion The fatty accumulation of liver cell in phlegm and dampness group has a close relation to the enhancement of the liver lipoganic gene expression.

Construction of pGL3-Basic-SREBP-1c-promoter reporter gene vector and detection of its function / 基础医学与临床

Objective To construct human SREBP-1c-promoter reporter gene vector and to detect its function.Methods Human blood genome DNA was extracted and pGL3-Basic-SREBP-1c-promoter reporter gene vector was constructed.Furthermore,the function of SREBP-1c-promoter was confirmed by dual-luciferase reporter assay.ResultspGL3-Basic-SREBP-1c-promoter reporter gene vector was successfully constructed and the promoter activity was obviously repressed by co-transfection FoxO1.Overexpression FoxO1 inhibited the SREBP-1c protein expression.Conclusion FoxO1 repressed the SREBP-1c protein expression through inhibition the SREBP-1c transcription.