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Isoliquiritigenin (ISL) is an active chalcone compound isolated from licorice. It possesses anti-inflammatory and anti-oxidative activities. In our previous study, we uncovered a great potential of ISL in treatment of type 2 diabetes mellitus (T2DM). Therefore, this study aims to reveal the mechanism underlying the alleviatory effects of ISL on T2DM-induced glycolipid metabolism disorder. High-fat-high-sugar diet (HFD) combined with intraperitoneal injection of streptozotocin (STZ) were used to establish T2DM mice model. All animal experiments were carried out with approval of the Committee of Ethics at Beijing University of Chinese Medicine. HepG2 cells were used in in vitro experiments, and sodium palmitate (SP) was applied to establish insulin resistance (IR) model cells. The effects of ISL on body weight, fasting blood glucose levels, and pathological changes in the livers of mice were examined. Enzyme-linked immune sorbent assay (ELISA) and real-time quantitative PCR (RT-qPCR) were applied to detect the regulatory effects of ISL on key targets involved in glucolipid metabolism. Additionally, molecular docking and analytical dynamics simulation methods were used to analyze the interaction between ISL and key target protein. The results indicate that ISL significantly downregulates the transcriptional levels and inhibits the activities of key enzymes involved in gluconeogenesis, including pyruvate carboxylase (PC), phosphoenolpyruvate carboxykinase (PEPCK), and fructose-1, 6-bisphosphatase (FBP). It also downregulates the transcriptional and protein levels of hepatocyte nuclear factor 4α (HNF4α) and cAMP response element binding protein (CREB), the two transcriptional factors involved in gluconeogenesis. Thus, ISL inhibits hepatic gluconeogenesis in T2DM mice. In addition, ISL reduces total cholesterol (TC) and triglyceride (TG) levels in the livers of T2DM mice. Moreover, ISL downregulates the mRNA levels of lipogenesis genes and upregulates those of genes involved in fatty acid oxidation, lipid uptake, and lipid export. In conclusion, ISL suppresses hepatic gluconeogenesis, promotes lipolysis, and restrains lipogenesis in T2DM mice, thereby improving the abnormal glycolipid metabolism caused by T2DM.
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OBJECTIVE：To st udy the improvement effects and its mechan ism of alisol B 23-acetate on glycolipid metabolism disorder in obesity model mice. METHODS ：The mice was given high-fat diet for 10 weeks to induce obesity model. Model mice were randomly divided into model group ，orlistat group （positive control ，15.6 mg/kg）， alisol B 23-acetate low-dose ， medium-dose and high-dose groups （7.5，15，30 mg/kg），with 10 mice in each group. Another 10 mice fed with normal diet were set as normal group. The mice in normal group and model group were given water intragastrically ，and administration groups were given the corresponding drugs intragastrically ，with the volume of 20 mL/kg，once a day ，for consecutive 4 weeks. After last medication，body weight ，waist circumference ，body fat ，muscle and body fluid mass were measured ；the serum levels of blood lipids indicators （TC，TG，HDL-C，LDL-C）and blood glucose were determined. The levels of PPAR-γ，NF-κB and IL-6 in liver tissue as well as serum level of TNF-α were determined by ELISA. The pathomorphological changes of visceral fat and liver tissue in mice were observed by HE staining. RESULTS ：Compared with normal group ，body weight ，waist circumference ，body fat and body fluid mass were significantly increased in model group （P＜0.01）；serum levels of TC ，TG，HDL-C，blood glucose and TNF-α，the levels of PPAR-γ，NF-κB and IL-6 in liver tissue were increased significantly （P＜0.05 or P＜0.01）；the structure of adipocytes was ruptured ，the volume of adipocytes was increased ，accompanied by inflammatory cell infiltration ；a large number of liver cells were edema ，and cytoplasm was loose and light stained，accompanied by fatty degeneration. Compared with model group ，the body weight ，body fat and body fluid mass as well as serum le vels of TG and TNF-α in alisol B 23-acetate groups were significantly reduced （P＜0.01）；the levels of TC and blood glucose in serum ，IL-6 in liver tissue were significantly decreased in alisol B 23-acetate medium-dose and high-dose groups （P＜0.05 or P＜0.01），and the level of PPAR-γ in liver tissue was increased significantly（P＜0.05 or P＜0.01）； the waist circumference and NF-κB levels in liver tissue in alisol B 23-acetate high-dose group were decreased significantly （P＜ 0.01）；serum level of HDL-C in alisol B 23-acetate medium-dose group were decreased significantly （P＜0.01）；the adipocytes were closely arranged and small in size ；the hepatocytes were mild to moderate swelling ，a small amount of cytoplasm was loose ， light stained or vacuolated ，and a small number of hepatocytes were accompanied by steatosis and small focal infiltration of inflammatory cells. CONCLUSIONS ：Alisol B 23-acetate can improve the disorder of glucose and lipid metabolism in obesity model mice ，and its mechanism may be related to the regulation of PPAR-γ，NF-κB，IL-6 levels in liver tissue and TNF-α levels in serum.
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Objective@#Investigate the effects of inducible ppp2r1a knockout on main physiological function in adult mice and study the mechanism.@*Methods@#Ppp2r1aflox/flox mice and CAGG-CreER mice were hybridized to obtain 20 CAGG-CreER ppp2r1aflox/flox and 20 mice in homozygous group. Two groups of mice were divided into 4 groups respectively, finally we got 8 groups with 5 mice in each group. Tamoxifen was injected intraperitoneally to acquire inducible ppp2r1a knockout mice. The knockout efficiency of PP2A Aα in vital organs was measured by Western blot. At 0, 2, 4 and 6 days after injection, we measured body weight, histopathological change, peripheral blood cell counts and blood biochemical. Real-time PCR was performed to measure expression of liver glucolipid metabolism genes.@*Results@#After tamoxifen injection for 6 days, the knockout efficiency of PP2A Aα in vital organs was 35%, 12%, 15%, 60%, 69% and 72%, respectively in heart, liver, spleen, lung, kidney and brain. After tamoxifen injection for 6 days, the weight of homozygous mice was lower than that of wild type mice, with values of (17.42±1.76) g and (21.69±1.82) g, respectively (P<0.05). Moreover, the activity level, abdominal and renal fat were significantly decreased in homozygous mice. Homozygous mice survived no more than 7 days. Compared with wild type mice, the organ coefficient of spleen of homozygous mice was decreased at the 6th day, with values of (0.59±0.10)% and (0.36±0.05)% respectively (P<0.05). Obvious spleen atrophy and marked decrease of nucleated cells were showed by performing HE staining. Tunel staining revealed increased apoptosis ratio of splenic lymphocytes in homozygous mice. The levels of alanine aminotransferase (ALT) and aspartate transaminase (AST) of homozygous mice were higher than wild type mice (P<0.05). The values of ALT and AST in homozygous mice were (153.68±62.80) U/L and (193.2±44.28) U/L. The corresponding values in wild type mice were (41.02±12.91) U/L and (69.40±9.55) U/L. The above results indicated that ppp2r1a knockout caused liver damage. Blood sugar level of homozygous mice was lower than in wild type mice (P<0.05), with values of (4.20±1.99) mmol/L and (8.88±0.65) mmol/L respectively. Plasma total cholesterol (TC), high density lipoprotein (HDL) and β-hydroxybutyric acid (β-HB) level of homozygous mice were higher than those of wild type mice (P<0.05). The values of TC, HDL and β-HB in homozygous mice were (3.12±0.39), (1.53±0.38) and (2.49±0.89) mmol/L. The corresponding values in wild type mice were (1.69±0.92), (0.78±0.50) and (0.45±0.30) mmol/L respectively. The above results indicated that ppp2r1a loss interfered glucose and cholesterol metabolism. In addition, we also found that the white blood cell count (WBC) and lymphocyte count (LYM) of homozygous mice were lower than in wild type mice (P<0.05). The values of WBC and LYM in homozygous mice were (1.88±0.89)×109/L and (0.92±0.37)×109/L respectively. The corresponding values in wild type mice were (3.91±0.80)×109/L and (2.74±0.52)×109/L respectively. The mRNA levels of glucose-6-phosphatase (G6P) and phosphoenolpyruvate carboxykinase (PEPCK) of homozygous were lower than wild type mice (P<0.05). The fold change of G6P and PEPCK in homozygous mice was 0.46±0.11 and 0.72±0.07 respectively. The corresponding fold change in wild type mice was 1.02±0.07 and 1.02±0.06 respectively.@*Conclusion@#Whole body ppp2r1a is essential for the survival of adult mice, due to the important role in maintaining the metabolism of glucose and cholesterol of liver.
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AIM: To investigate whether inactivation of extracellular signal-regulated kinase 1/2 ( Erk1/2 ) will affect the function of fibroblast growth factor 21 (FGF21) to regulate glucose and lipid metabolism .METHODS:Male db/db mice (8 weeks old) were treated with U0126 (an inhibitor of Erk1/2 kinase) for 1 week, and then treated with re-combinant human FGF21 protein and adenovirus-mediated FGF21 (Ad-FGF21).The profile changes of blood glucose and blood lipid were evaluated at 120 min or 4 weeks after FGF21 administration.Meanwhile, the molecular mechanism was ex-plored by in vitro study.RESULTS: Treatment of db/db mice with recombinant human FGF21 protein significantly re-duced blood glucose and triglyceride levels at 120 min after FGF21 administration , but these changes were comparable in U0126-treated mice .Furthermore , abnormal glucose and triglyceride levels , and glucose and insulin tolerance were strong-ly improved in db/db mice as accompanied with decreasing body fat content after 4 weeks of ad-FGF21 administration .In-terestingly, treatment with or without U0126 did not influence these effects of FGF21.Mechanically, treatment with Ad-FGF21 significantly upregulated the protein levels of p-Erk1/2 and peroxisome proliferator-activated receptor γ( PPARγ) as well as the expression of adiponectin at mRNA and protein levels in adipose tissues .However , treatment with or without U0126 did not change the profiles .On the other hand , in vitro experiments also indicated that treatment of adipocytes with recombinant human FGF 21 protein significantly activated Erk 1/2 phosphorylation , and upregulated the expression levels of PPARγand adiponectin (P<0.05).However, pre-administration of U0126 did not affect the profiles.CONCLUSION:Pharmaceutical inactivation of Erk 1/2 by U0216 does not affect the biological function of FGF 21 to regulate blood glucose balance and improve abnormal blood lipids in vivo.
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Objective To analyze the morbidity of the old people with hypertension and metabolic syndrome (MS),the characteristics of MS components distribution,and correlation hypertension and MS.Methods 438 old patients over 60 with hypertension were selected randomly from cheek-up crowd in the physical examination center of Affiliated Zhongshan Hospital of Dalian University in 2013.Abdominal girth,height,body mass were measured,and then calculated BMI.The indicators such as FPG,TC,TG,HDL-C,LDL-C were detected and analyzed.Results The total morbidity of MS in the old people with hypertension was 37.7％,39.0％ from male people,36.7％ from female people,and there was no difference between genders(x2 =0.46,P ＞ 0.05).The level of BMI,abdominal girth,FPG,and TG in the old people with MS were higher than the people without MS(t =4.83,8.53,5.08,7.29,all P ＜0.05),and HDL-C was lower than the people without MS(t =-9.67,P ＜ 0.05).The level of FPG in women was higher than that in men apparently(x2 =5.82,P ＜ 0.05),and the level of HDL-C was lower than that in men apparently (x2 =8.73,P ＜ 0.01).The risk factors to MS include BMI,abdominal girth,FPG,TG (OR =2.139,1.106,2.156,2.315,all P ＜0.05),and HDL-C is protective factor to MS(OR =0.039,P ＜0.05).Conclusion Hypertension might increase MS morbidity of old patients.Hypertension related with MS closely.The risk factors include BMI,abdominal girth,FPG,TG,on the other hand HDL-C is protective factor to MS.