Niacin accelerates LDL-C uptake in HepG2 cells via downregulation of PCSK9 / 中国药理学通报

Aim To explore the effects of niacin on LDL-C uptake and metabolism in HepG2 cells,and to clarify the functions of niacin in lipid-lowering and slo-wing the atherosclerosis process,thus to provide a sci-entific basis for niacin as a lipid-lowering drug in clini-cal development.Methods Oil red O staining was used to observe HepG2 cells after lipid uptake.Enzy-matic method was used to determine the content of in-tracellular free cholesterol (FC)and total cholesterol (TC).The LDLR levels on the surface of cell mem-brane were detected by immunofluorescence flow cy-tometer.The mRNA and protein expressions of LDLR, SREBP2 and PCSK9 were analyzed by qPCR and Western blot.Results The results of oil red O staining showed that the rate of oil red O-positive cells and the number of red lipid droplets were significantly in-creased in niacin group than control group.Niacin sig-nificantly increased the levels of TC and FC in HepG2 cells(P <0.05 ).What’s more,niacin significantly upregulated the expression of LDLR and significantly downregulated the protein expression of PCSK9,while it had no effect on the expression of SREBP2.Conclu-sion Niacin accelerates LDL-C uptake probably via downregulating the expression of PCSK9 and reducing the degradation of LDLR protein in HepG2 cells.

Role of PCSK9 and IDOL in curcumin accelerating LDL-C uptake in HepG2 cells / 中国药理学通报

Aim To explore the lipid-lowering mecha-nisms of curcumin from the molecular levels and pro-vide scientific basis for clinical development of lipid-lowering drugs.Methods Using oil red O staining and enzymic to determinate the levels of cholesterol in HepG2 cells.Moreover,uptaking of DiI-LDL was also measured.The expressions of mRNA and protein were detected by RT-Q-PCR and Western blot.Results The red lipid droplets and the levels of TC and FC sig-nificantly increased in HepG2 cells after treated with curcumin.The orange red fluorescence was higher than that of control.Curcumin could promote the expression levels of mRNA and protein of SREBP2 and LDLR, what′s more,curcumin could reduce the expression of the mature PCSK9 level and IDOL protein.Conclu-sion Curcumin accelerates LDL-C uptake probably via downregulating the expression of PCSK9 and IDOL in HepG2 cells.

Effects of TSG on H2O2-induced Apoptosis and Expressions of XIAP and p53 in HUVECs / 华中科技大学学报(医学版)

Objective To study the effects of tetrahydroxy stilbene glucoside(TSG)on H2O2‐induced apoptosis of human umbilical vein endothelial cells (HUVECs)and on the expressions of X‐linked inhibitor of apoptosis protein (XIAP)and p53.Methods HUVECs were cultured in vitro and divided into 6 groups:control group ,300 μmol/L H2O2 group ,1 μmol/L TSG+ 300 μmol/L H2O2 group ,10 μmol/L TSG+300 μmol/L H2O2 group ,100 μmol/L TSG+ 300 μmol/L H2O2 group ,30μmol/L Embelin+ 10 μmol/L TSG+ 300 μmol/L H2O2 group.The morphology of apoptotic cells was observed by Hoechst 33258 staining.The mRNA and protein expressions of XIAP ,p53 ,Caspase‐3 were detected by RT‐PCR and Western blotting , respectively.Results The number of apoptotic cells and the expression level of p53 were significantly increased while the ex‐pression level of XIAP was dramatically decreased in H2O2 group as compared with control group.The expression level of p53 and the number of apoptotic cells were down‐regulated while the expression level of XIAP was up‐regulated after treatment with 10 or 100 μmol/L TSG when compared with H2O2group.Moreover ,compared with those in 10 μmol/L TSGgroup ,the number of apoptotic cells and the expression of Caspase‐3 were significantly enhanced after pretreatment with 30 μmol/L Embelin for 6 h.Conclusion TSG can inhibit H2O2‐induced apoptosis of HUVECs by down‐regulating the expression level of p53 and up‐reg‐ulating the expression level of XIAP.

Relationship between HDL subclass distribution and plasma glucose and lipid levels in patients with metabolic syndrome / 中国病理生理杂志

AIM:To investigate high-density lipoprotein ( HDL) subclass distribution and to analyze the rela-tionship between HDL subclasses with plasma glucose and lipids in metabolic syndrome ( MS) .METHODS:Apolipopro-tein A-I ( apoA-I) contents of plasma HDL subclasses were determined by two-dimensional gel electrophoresis associated with immunodetection .The concentrations of lipids and apolipoproteins in the plasma were measured by an automated bio -chemical analyzer .RESULTS:Compared with the controls , the levels of fasting plasma glucose ( FPG) , total cholesterol (TC), triglyceride ( TG), low-density lipoprotein cholesterol ( LDL-C), LDL-C/high-density lipoprotein cholesterol (HDL-C), apolipoprotein B100(apoB100), apoB100/apoA-I, systolic blood pressure (SBP), body mass index (BMI) and HDL3b were increased in the MS patients (P<0.05).Meanwhile, HDL-C, apoA-I and preβ2-HDL, HDL2a and HDL2b were decreased in the MS patients (P<0.01).With the increase in the plasma glucose level , the contents of HDL2a and HDL2b were decreased in the MS patients (P<0.05), while preβ1-HDL was increased (P<0.05).With the decrease in the HDL-C level, the content of HDL2b was decreased in the MS patients (P<0.01), while preβ1-HDL was increased (P<0.01).With the increase in the TG level and the decrease in the HDL-C level, the content of HDL2b had a decrea-sing trend and the content of small-particle preβ1-HDL had an increasing trend , indicating that HDL maturation metabolism was disrupted.The correlation analysis showed that FPG was negatively correlated with the levels of HDL 2a and HDL2b, HDL-C was negatively correlated with the level of preβ1-HDL and positively correlated with the level of HDL 2b , and TG was positively correlated with the levels of preβ1-HDL and HDL3b .CONCLUSION:With the increases in the plasma glucose and TG, and the decrease in HDL-C in the MS patients, HDL particles have minifying tendency , and the maturation me-tabolism of HDL particles is disrupted .

Reform of innovative experimental teaching pattern in biotechnology / 中华医学教育探索杂志

According to the educational objectives of biotechnology in local universities, the fundamental ideas about reforming the experimental teaching in biotechnology were discussed from the multiple aspects including the resetting of experimental curses system , the contents and methods of teaching and the approaches of examining and assessing. The final aim is to train out more innovative biotechnological talents through systematic and standardized practice of innovative teaching to meet the needs of China during this economical and societal development.

Grasping the Special Feature in Improvement of the Quality of Experiemental Teaching of Biochemistry / 中华医学教育探索杂志

The paper discusses the experimental teaching reform of biochemistry by referring to the characteristics of biochemical development and special feature.The reform increases effectually the interests of medical students,and may contribute to their creative competence and the abilities of scientific research.

Relationship between subclasses of serum HDL and LPL gene HindⅢ polymorphism in hyperlipidemia / 中国病理生理杂志

AIM: To investigate lipoprotein lipase gene HindⅢ polymorphism and its relationship with serum lipids and apolipoprotein, serum HDL subclasses in patients with hyperlipoidemia. METHODS: Lipoprotein lipase gene HindⅢ polymorphism was assayed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The subclasses of serum HDL in 152 hyperlipoidemia patients and 128 healthy subjects were determined by two-dimensional gel electrophoresis conjunction with immunodetection method. RESULTS: H+H+ genotype and allele H+ in hyperlipoidemia and control groups were both the highest. In hyperlipidemia group, H+H+ genotypes tended to be higher than that in control group, while H+H- and H-H- genotypes were significantly lower (P