OBJECTIVE: To explore the protective effect and underlying mechanism of Lycium barbarum polysaccharides (LBP) in a non-alcoholic fatty liver disease (NAFLD) cell model. METHODS: Normal human hepatocyte LO2 cells were treated with 1 mmol/L free fatty acids (FFA) mixture for 24 h to induce NAFLD cell model. Cells were divided into 5 groups, including control, model, low-, medium- and high dose LBP (30,100 and 300 µg/mL) groups. The monosaccharide components of LBP were analyzed with high performance liquid chromatography. Effects of LBP on cell viability and intracellular lipid accumulation were assessed by cell counting Kit-8 assay and oil red O staining, respectively. Triglyceride (TG), alanine aminotransferase (ALT), aspartate aminotransferase (AST), adenosine triphosphate (ATP) and oxidative stress indicators were evaluated. Energy balance and mitochondrial biogenesis related mRNA and proteins were determined by quantitative real-time polymerase chain reaction and Western blot, respectively. RESULTS: Heteropolysaccharides with mannose and glucose are the main components of LBP. LBP treatment significantly decreased intracellular lipid accumulation as well as TG, ALT, AST and malondialdehyde levels (P<0.05 or P<0.01), increased the levels of superoxide dismutase, phospholipid hydroperoxide glutathione peroxidase, catalase, and ATP in NAFLD cell model (P<0.05). Meanwhile, the expression of uncoupling protein 2 was down-regulated and peroxisome proliferator-activated receptor gamma coactivator-1α/nuclear respiratory factor 1/mitochondrial transcription factor A pathway was up-regulated (P<0.05). CONCLUSION LBP promotes mitochondrial biogenesis and improves energy balance in NAFLD cell model.
Humans ; Non-alcoholic Fatty Liver Disease/drug therapy* ; Lycium/metabolism* ; Catalase/metabolism* ; Organelle Biogenesis ; Alanine Transaminase ; Uncoupling Protein 2 ; Fatty Acids, Nonesterified ; Mannose ; Nuclear Respiratory Factor 1/metabolism* ; PPAR gamma/metabolism* ; Phospholipid Hydroperoxide Glutathione Peroxidase ; Drugs, Chinese Herbal/pharmacology* ; Malondialdehyde/metabolism* ; Superoxide Dismutase/metabolism* ; Polysaccharides/pharmacology* ; Triglycerides ; RNA, Messenger ; Aspartate Aminotransferases ; Glucose ; Adenosine Triphosphate

OBJECTIVETo observe the intervention and mechanism of Qushi Huayu Recipe (QHR) on gene expression profiles in high lipid diet induced fatty liver rats.

METHODSFatty liver model was prepared in 20 male SD rats using single high fat diet (88% common forage +2% cholesterol +10% lard). Four weeks after modeling they were divided into the model group and the QHR group according to random digit table, 10 in each group. QHR (at 0. 93 g crude drug/100 g body weight) and distilled water was respectively to rats in the QHR group and the model group by gastrogavage while modeling, once per day. Meanwhile, 10 SD male rats were recruited in a normal group, administered with equal volume of distilled water by gastrogavage. At the end of week 8 all rats were sacrificed, and blood and livers were collected for subsequent analysis. Contents of liver triglyceride (TG) and free fatty acid (FFA) , activities of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were detected using biochemical assay. Pathological changes of liver tissue were observed using H&E and oil red O stain. Liver gene expressions were detected by Affymetrix gene expression profiles. Differentially expressed genes were compared between the QHR group and the model group, functions of differentially expressed genes and signal pathways involved analyzed. Ten differentially expressed genes involved in glycolipid metabolism with fold change more than 2 were selected for verification by real-time PCR.

RESULTS(1) Compared with the normal group, contents of liver TG and FFA, and serum activities of ALT and AST obviously increased in the model group (P <0. 01). Compared with the model group, contents of liver TG and FFA, and activities of ALT and AST obviously decreased in the QHR group (P <0. 05, P <0. 01). QHR could reduce high fat induced fatty degeneration of liver cells , alleviate inflammation, and improve pathological changes of liver tissue. (2) Compared with the model group, there were 80 differentially expressed genes (with fold change > 2, P < 0.05) with clear functions and appointed gene names, including 44 up-regulated and 36 down-regulated genes. Eighty genes were involved in 27 signal pathways with statistical difference, including glycerolipid metabolism, adipocytokine signaling pathway, insulin signal pathway, drug metabolism signal pathway, etc (P < 0.05). (3) RT-PCR results of 10 glycolipids metabolism regulating genes such as Gk, Scd1, Gpat2, G6pc, Irs1, and so on showed that all RT-PCR genes were completely coincide with up-regulated or down-regulated tendency in results of gene chips. 80% genes had approximate fold change.

CONCLUSIONQHR could regulate gene expressions related to fat metabolism, carbohydrate metabolism, anti-lipid peroxidation, and drug metabolism in high fat diet induced fatty liver rats, and its comprehensive pharmacological actions could be manifested.

Alanine Transaminase ; metabolism ; Animals ; Aspartate Aminotransferases ; metabolism ; Carbohydrate Metabolism ; Diet, High-Fat ; Drugs, Chinese Herbal ; pharmacology ; Fatty Acids, Nonesterified ; metabolism ; Fatty Liver ; metabolism ; Lipid Metabolism ; Lipid Peroxidation ; Male ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Transcriptome ; drug effects ; Triglycerides ; metabolism

Mammalian pancreatic β-cells play a pivotal role in development and glucose homeostasis through the production and secretion of insulin. Functional failure or decrease in β-cell number leads to type 2 diabetes (T2D). Despite the physiological importance of β-cells, the viability of β-cells is often challenged mainly due to its poor ability to adapt to their changing microenvironment. One of the factors that negatively affect β-cell viability is high concentration of free fatty acids (FFAs) such as palmitate. In this work, we demonstrated that Yes-associated protein (Yap1) is activated when β-cells are treated with palmitate. Our loss- and gain-of-function analyses using rodent insulinoma cell lines revealed that Yap1 suppresses palmitate-induced apoptosis in β-cells without regulating their proliferation. We also found that upon palmitate treatment, re-arrangement of F-actin mediates Yap1 activation. Palmitate treatment increases expression of one of the Yap1 target genes, connective tissue growth factor (CTGF). Our gain-of-function analysis with CTGF suggests CTGF may be the downstream factor of Yap1 in the protective mechanism against FFA-induced apoptosis.
Actins ; metabolism ; Adaptor Proteins, Signal Transducing ; antagonists & inhibitors ; genetics ; metabolism ; Animals ; Apoptosis ; drug effects ; physiology ; Bridged Bicyclo Compounds, Heterocyclic ; pharmacology ; Cell Line, Tumor ; Connective Tissue Growth Factor ; genetics ; metabolism ; pharmacology ; Cytochalasin D ; pharmacology ; Fatty Acids, Nonesterified ; pharmacology ; HEK293 Cells ; Humans ; Immunohistochemistry ; Insulin-Secreting Cells ; cytology ; drug effects ; metabolism ; Mice ; Microscopy, Fluorescence ; Palmitic Acid ; pharmacology ; Phosphoproteins ; antagonists & inhibitors ; genetics ; metabolism ; RNA Interference ; RNA, Small Interfering ; metabolism ; Rats ; Recombinant Proteins ; genetics ; metabolism ; pharmacology ; Thiazolidines ; pharmacology

This study is to evaluate the therapeutic effect of fibroblast growth factor 21 (FGF21) on type 2 diabetic mice model and to provide mechanistic insights into its therapeutic effect. Type 2 diabetic animal model was established with high calorie fat diet and low dose streptozotocin (STZ) injection. Mice were then randomized into 5 groups: model control, FGF21 0.25 and 0.05 μmol x kg(-1) x d(-1) groups, insulin treatment group. Ten age-matched normal KM mouse administered with saline were used as normal controls. Serum glucose, insulin, lipid products and the change of serum and liver tissue inflammation factor levels between five groups of mouse were determined. The results showed that blood glucose, insulin, free fatty acids (FFAs), triglycerides, and inflammatory factor average FGF-21 of type 2 diabetes model group and normal control group were significantly higher (P < 0.01), while compared with insulin group, no difference was significant. Average blood glucose, insulin, blood lipid and inflammatory factor of FGF-21 treatment group compared with type 2 diabetes group was significantly lower (P < 0.01) and insulin group has no difference with the model control group. The results of OGTT and HOMA-IR showed that insulin resistance state was significantly relieved in a dose-dependent manner. Thus, this study demonstrates that FGF-21 significantly remits type 2 diabetic mice model's insulin resistance state and participates in the regulation of inflammatory factor levels and type 2 diabetes metabolic disorders.
Animals ; Blood Glucose ; Diabetes Mellitus, Experimental ; drug therapy ; Diabetes Mellitus, Type 2 ; drug therapy ; Diet, High-Fat ; Fatty Acids, Nonesterified ; blood ; Fibroblast Growth Factors ; pharmacology ; Insulin ; blood ; Insulin Resistance ; Mice ; Streptozocin ; Triglycerides ; blood

OBJECTIVETo establish an in vitro cell model for investigating hepatic steatosis in non-alcoholic fatty liver disease.

METHODSL-02 cells cultured in 1640 containing 10% fetal bovine serum were divided into control group and model group. At 70%-80% confluency, L-02 cells in the model group were exposed to a long-chain mixture of free fatty acids (FFA, oleate and palmitate ) for 24 h, and cells in control group were treated with fresh medium. Lipid droplets in the cells were observed and total lipid content was determined with Oil Red O staining. The morphology of lipid droplets, trilyceride level, malonaldehyde content and cell apoptosis rate were evaluated to verify the cell model, and the effect of Huganqingzhi tablet on the lipid droplets was observed.

RESULTSA large number of lipid droplets were found in the cell model, which showed markedly increased level of triglyceride without significant changes of malonadehyde content or cell apoptosis rate. Intervention with two doses of Huganqingzhi tablet significantly decreased the number of lipid droplets and trilyceride content in the cell model.

CONCLUSIONhepatic steatosis L-02 cell model can be established by long-chain mixture of free fatty acids (oleate:spalmitate=2:1) for therapeutic drug studies.

Apoptosis ; Cell Line ; Drugs, Chinese Herbal ; pharmacology ; Fatty Acids, Nonesterified ; chemistry ; Fatty Liver ; Humans ; Malondialdehyde ; analysis ; Non-alcoholic Fatty Liver Disease ; Triglycerides ; analysis

BACKGROUNDPreeclampsia (PE) is associated with abnormal fatty acid beta-oxidation (FAO), especially metabolic disorders of long-chain fatty acid oxidation. The role of FAO dysfunction in inadequate invasion is unclear. The aim of this study was to explore the influence of various lengths fatty acids oxidation on invasiveness of trophoblasts.

METHODSPrimary human trophoblast cells and HTR8/SVneo cells were treated with fatty acids of various lengths. Morphological changes, lipid deposition and ultrastructure changes of trophoblast cells were detected. Cells invasiveness was determined by transwell insert. CPT1, CPT2 and long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) protein expression were analyzed. The correlation between intracellular lipid droplets deposition and cells invasiveness was evaluated.

RESULTSCells treated with long-chain fatty acids showed significant increased lipid droplets deposition, severe mitochondrial damage, decreased CPT2 and LCHAD protein expression (P < 0.05) but no significant difference in CPT1 protein expression (P > 0.05). Invasiveness of the trophoblast cells of the LC-FFA group significantly decreased (P < 0.05). Intracellular lipid droplets deposition was negatively correlated with invasivenss (R = -0.745, P < 0.05).

CONCLUSIONTrophoblast cells after stimulation with long chain fatty acids exist fatty acid oxidation disorders, and reduce the ability of trophoblastic invasion.

Cell Line ; Cells, Cultured ; Fatty Acids, Nonesterified ; pharmacology ; Humans ; Lipid Metabolism ; Long-Chain-3-Hydroxyacyl-CoA Dehydrogenase ; metabolism ; Trophoblasts ; drug effects

OBJECTIVETo investigate the effects of glucagon-like peptide-1 (GLP-1) on liver oxidative stress, TNF-α and TGF-β1 in rats with diet-induced non-alcoholic fatty liver disease (NAFLD).

METHODSThirty male rats were randomly divided into 3 equal groups and fed for 16 weeks with normal diet (ND), high-fat diet (HFD), or high-fat diet with intraperitoneal injection of liraglutide (GLP-1, administered in the later 4 weeks). The rats were then sacrificed to obtain blood samples and liver tissues for analyzing the levels of blood aminotransferase (ALT), triglyceride (TG), and total-cholesterol (TC) using an automatic biochemical analyzer and the levels of superoxide dismutase (SOD), malondial-dehyde (MAD), free fatty acid (FFAs), TNF-α in the liver homogenates and TGF-β1 in serum by radioimmunoassay or ELISA.

RESULTSCompared with ND group, HFD group showed significantly increased body weight, liver index, serum levels of ALT, TG, TC, and TGF-β1, and TG, TC, MAD, FFAs, and TNF-α in the liver homogenates, with also significantly increased degree of hepatic steatosis and inflammation activity (P<0.05) and lowered level of SOD. All these changes were markedly ameliorated in GLP-1 group (P<0.05).

CONCLUSIONLiraglutide can reduce high-fat diet-induced hepatic steatosis, improve oxidative stress and lipid peroxidation, and decrease TGF-β1 and TNF-α levels in serum and liver homogenates, suggesting its potential as a therapeutic agent for NAFLD.

Alanine Transaminase ; blood ; Animals ; Cholesterol ; blood ; metabolism ; Fatty Acids, Nonesterified ; metabolism ; Hypoglycemic Agents ; pharmacology ; Liraglutide ; pharmacology ; Liver ; metabolism ; pathology ; Male ; Malondialdehyde ; metabolism ; Non-alcoholic Fatty Liver Disease ; blood ; metabolism ; pathology ; Oxidative Stress ; drug effects ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Superoxide Dismutase ; metabolism ; Transforming Growth Factor beta1 ; blood ; Triglycerides ; blood ; metabolism ; Tumor Necrosis Factor-alpha ; metabolism

Ginsenoside Rb1 is an active component in ginseng. Previous in vitro experiments showed that ginsenoside Rb1, could inhibit lipolysis and promote glucose transporter in adipocytes. This study focused on the effect of ginsenoside Rb1 in insulin resistance and ectopic fat deposit in obese mice induced by high fat diet and its molecular mechanism. Obese male C57/L mice induced by high fat diet were randomly divided into the diet-induced obesity group (DIO group), the ginsenoside Rb1 group (Rb1 group) and the rosiglitazone group (Rog group), and continuously fed with high fat diet. In addition, male C57/L mice fed with normal diet were selected as the normal group (NC group). Mice in Rb1 group and Rog groups were intraperitoneally injected with ginsenoside Rb1 and rosiglitazone with the dosage of 20 mg x kg(-1) and 10 mg x kg(-1), respectively. NC and DIO groups were intraperitoneally injected with the same amount of saline. Two weeks later, the intraperitoneal glucose tolerance test (IPGTT) was performed. Three days later, the mice were killed, and their serum samples were collected to detect insulin and free fatty acid (FFA). Their livers were weighed to examine the triglyceride content, and a pathological detection was performed. Epididymal adipose tissues were weighed, and PDE3B, HSL and perilipin were detected by Western blotting. The results showed that the treatment with ginsenoside Rb1 for two weeks could improve the glucose tolerance of obese mice. Except for 0-120 min, the areas under the glucose tolerance curve (0-30 min, 0-60 min and 0-90 min) in the Rb1 group were less than that in the DIO group (P < 0.05, n = 5), with a much lower HOMA-IR (P < 0.05, n = 5). The fat level of obese mice was significantly reduced by Rbl (P < 0.05, n = 5), and so were liver weight/weight (P < 0.05, n = 8). The increased serum FFA of obese mice declined after the treatment of Rb1 (P < 0.05, n = 8). Rb1 could partially recover the expression of perilipin in adipose tissues, but without obvious change in the expressions of PDE3B and HSL and the phosphorylated activation. The above findings indicated that ginsenoside Rb1 could reduce the release of FFA and alleviate the ectopic deposit of triglyceride by up-regulating the expression of perilipin in adipose tissue, which may be one of its mechanisms for improving the insulin resistance and abnormal glucose metabolism of organisms.
Adipose Tissue ; drug effects ; pathology ; Animals ; Body Weight ; drug effects ; Diet, High-Fat ; adverse effects ; Dose-Response Relationship, Drug ; Fatty Acids, Nonesterified ; blood ; Gene Expression Regulation ; drug effects ; Ginsenosides ; pharmacology ; Glucose Tolerance Test ; Insulin ; blood ; Insulin Resistance ; Liver ; drug effects ; metabolism ; Male ; Mice ; Mice, Inbred C57BL ; Obesity ; blood ; etiology ; metabolism ; pathology ; Organ Size ; drug effects ; Triglycerides ; metabolism

BACKGROUNDGlucagon-like peptide-1 (GLP-1) reduces fatty acid-induced beta-cell lipotoxicity in diabetes; however, the explicit mechanisms underlying this process are not fully understood. This study was designed to investigate the involvement of microRNA, which regulates gene expression by the sequence-specific inhibition of mRNA transcription in the GLP-1 mediation of beta-cell function.

METHODSThe cell viability and apoptosis were determined using an methyl thiazoleterazolium (MTT) assay and flow cytometry. The expression of genes involved in beta-cell function, including microRNA-34a and sirtuin 1, were investigated using real-time PCR. The underlying mechanisms of microRNA-34a were further explored using cell-transfection assays.

RESULTSA 24-hours incubation of INS-1 cells with palmitate significantly decreased cell viability, increased cell apoptosis and led to the activation of microRNA-34a and the suppression of sirtuin 1. A co-incubation with GLP-1 protected the cells against palmitate-induced toxicity in association with a reduction in palmitate-induced activation of microRNA-34a. Furthermore, palmitate-induced apoptosis was significantly increased in cells that were infected with microRNA-34a mimics and decreased in cells that were infected with microRNA-34a inhibitors.

CONCLUSIONMicroRNA-34a is involved in the mechanism of GLP-1 on the modulation of beta-cell growth and survival.

Animals ; Apoptosis ; drug effects ; Cell Line ; Cell Survival ; drug effects ; Fatty Acids, Nonesterified ; toxicity ; Glucagon-Like Peptide 1 ; pharmacology ; Insulin-Secreting Cells ; cytology ; drug effects ; metabolism ; MicroRNAs ; genetics ; metabolism ; Palmitic Acid ; pharmacology ; Rats ; Real-Time Polymerase Chain Reaction

This study is to observe anti-lipotoxic effect of sesamin on renovascular hypertensive rats fed with a high-fat, high-sucrose diet. Thirty-four complex model rats were induced by two-kidney, one-clip method and on high-fat and refined-carbohydrate diet for thirteen weeks. From the fifth week, intragastric administration of sesamin (120, 60 and 30 mg x kg(-1) x d(-1)) lasted for eight weeks. Blood pressure (BP), blood fat (BF), blood glucose (BG), free fatty acids (FFA), insulin (Ins), tumor necrosis factor (TNF)-alpha and interleukin (IL)-6 were determined. Pathological changes of pancreas, perirenal fat and liver were semiquantitatively analyzed. In sesamin (120 and 60 mg x kg(-1) x d(-1)) group, it was found that there were decrease of levels of BP, BF, BG, TNF-alpha, IL-6 and FFA, improvement of insulin resistance and glucose tolerance, alleviation of body weight, humid weight of fat, liver and pancreas and their organ index, and reduction of islet cell hyperplasia and amount of lipid droplet vacuoles in lipocyte and hepatocyte. It is implied that sesamin had anti-lipotoxic effect and its mechanism may be closely associated with the amelioration of insulin resistance via reducing lipidoses in hepatocyte and inflammatory adipokines such as TNF-alpha and IL-6.
Adipocytes ; drug effects ; Animals ; Anticholesteremic Agents ; administration & dosage ; pharmacology ; Antihypertensive Agents ; administration & dosage ; pharmacology ; Blood Glucose ; metabolism ; Blood Pressure ; drug effects ; Body Weight ; drug effects ; Cholesterol ; blood ; Diet, High-Fat ; Dioxoles ; administration & dosage ; pharmacology ; Dose-Response Relationship, Drug ; Fatty Acids, Nonesterified ; blood ; Glucose Tolerance Test ; Hypertension, Renovascular ; blood ; pathology ; Insulin ; blood ; Insulin Resistance ; Interleukin-6 ; blood ; Islets of Langerhans ; pathology ; Lignans ; administration & dosage ; pharmacology ; Liver ; pathology ; Male ; Pancreas ; pathology ; Rats ; Rats, Sprague-Dawley ; Sucrose ; Triglycerides ; blood ; Tumor Necrosis Factor-alpha ; blood