The interrelationships between serum HDL subpopulations and triacyglycerol

AIM: To Study the influence of plasma TG level on the contents of serum HDL subpopulations. METHODS: Classified by the contents of serum TG, the serum level of HDL subpopulations in 106 normal TC and 183 high TC subjects were analyzed by two-dimensional gel electrophoresis coupled with immunodection method. RESULTS: The apo-AⅠcontents of per-β1-HDL, HDL3c, HDL3b and HDL3a were higher in a certain extent in TC high subjects vs corresponding TC desirable subjects. The apo-AⅠ contents of per-β1-HDL （in borer-line high TG subgroup） and HDL3b （in very high TG subgroup） were significantly higher (P<0.05 or P<0.01), while the apo-AⅠ contents of HDL2b and HDL2a were all lower in TC high subjects vs corresponding TC normal subjects. With the increase in plasma TG levels, the apoA-Ⅰ content of pre-β1-HDL increased, and it was significantly higher (P<0.05 or P<0.01) in borderline-high TG(except TC desirable subjects), high TG and very high TG subgroups vs corresponding normal TG subgroup. Contents of HDL3b and HDL3a had the same tendency, and in TC high subjects contents of HDL3b (in very high TG subgroup) and HDL3a (in every subgroups, in which levels of TG were higher) were significantly higher (P＜0.05 and P＜0.01） than in normal TG subgroup. On contrast, the apoA-Ⅰcontents of HDL2b and HDL2a following with the increase of plasma TG levels tended to become lower. Contents of HDL2b were significantly lower (P<0.05) in high TG subgroup and very high TG subgroup vs corresponding normal TG subgroup, and in TC high subjects contents of HDL2a were significantly lower (P<0.05) in very high TG subgroups vs normal TG subgroup. CONCLUSION: Our data show the general shift toward smaller size of HDL particle size with the increase in TC and TG levels. Contents of TC and TG are very important to contents of HDL subclasses.     

Influences of apolipoprotein CII concentrations on high-density lipoprotein subclass distribution

AIM: To investigate the influence of serum apolipoprotein (apo) CII concentrations on the distribution of serum high-density lipoprotein (HDL) subclasses. METHODS: Serum HDL subclasses in 247 subjects were determined by two dimensional gel electrophoresis-immunodetection. RESULTS: With the increase in serum apolipoprotein CII levels, age, BMI, the contents of TG, TC, apoB100, apoCII, apoCIII, apoE, preβ1-HDL, preβ2-HDL, HDL3b and HDL3a increased significantly, but the contents of HDL-C, HDL2a and HDL2b decreased remarkably. The contents of preβ1-HDL increased with the rise in apoCII and apoA I levels, whereas the content of HDL2b increased with the rise in serum apoA I level in the same apoC II group, but decreased with the increase in serum apolipoprotein CII level in the same apoA I group. With the increase in the ratio of apoCII/ apoCIII, the content of preβ1-HDL elevated, but the content of HDL2b decreased. The correlation analysis illustrated that the apoCII level was positively correlated with preβ1-HDL (r=0.186, P<0.01), but inversely correlated with HDL2b (r=-0.149, P<0.05). The apoA I level was positively associated with all HDL subclasses (r in the range of 0.349-0.587, P<0.01). In addition, the apoCIII level was positively correlated with preβ1-HDL (r=0.184, P<0.01) and preβ2-HDL (r=0.178, P<0.01), while the apoE level was positively correlated with HDL3a (r=0.040, P<0.05). The apoB100 level was inversely correlated with HDL2a (r=-0.102, P<0.05). CONCLUSION: The particles of HDL show a general shift towards smaller size with the increase in apoCII levels, indicating that the maturation of HDL is abnormal. Whereas the contents of apoA I level correct the effect of apoCII on the distribution profile of HDL subclasses. The ratio of apoCII/apoCIII might also been taken as one of the indexes reflecting the distribution profile of serum HDL subclasses.     

Subclasses of serum HDL in middle and old aged patients with hyperlipidemia in Chengdu City

AIM: To detect the change of composition and ratio of serum HDL subclasses and explore the relationship between these changes and the plasma lipid level in patients with hyperlipidemia. METHODS: The components of subclasses of serum HDL in 172 middle and old aged patients with hyperlipidemia and 115 healthy middle and old aged were determined by dimensional gel electrophoresis associated with immuno-blotting method. RESULTS: Compared to the healthy controls, the contents of pre β1-HDL，　HDL3b and HDL3a were significantly higher (P＜0.05 or P＜0.01), while that of HDL2b was significantly lower (P＜0.01) in middle and old aged patients with hyperlipidemia. The content of pre β1-HDL increased with age in healthy controls, whereas the HDL2b decreased. The content of pre β1-HDL was significantly higher (P＜0.05), while the HDL2b (P＜0.05) was significantly lower in men than in women in patients with hyperlipidemia and the healthy controls. In middle and old aged patients with hyperlipidemia, the content of pre β1-HDL was positively correlated with the serum TG, TC, apoB100, apoCⅡ, apoCⅢ, apoE and TG/HDL-C (r=0.432; r=0.243; r=0.341; r=0.259; r=0.335; r=0.308 and r=0.453, P＜0.05 or P＜0.01), while it was negatively correlated with HDL-C (r=－0.167, P＜0.05). The content of HDL2b was negatively correlated with TG, TC, apoCⅡ, apoCⅢ and TG/HDL-C (r=－0.296; r=－0.156; r=－0.182; r=－0.216; r=－0.203 and r=－0.313, P＜0.05 or P＜0.01), while it was positively correlated with HDL-C (r=0.124, P＜0.05). CONCLUSIONS: The particle of HDL in the middle and old aged patients with hyperlipidemia showed a general shift towards smaller size, which indicated that the reverse cholesterol transport might be weakened. Men had smaller HDL particle size than women.     

Relationship between subclasses of serum HDL and LPL gene HindⅢ polymorphism in hyperlipidemia

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<0.05). In hyperlipidemia group allele H+ carriers' frequency tended to be higher than that in control group (P<0.05). In hyperlipoidemia group, the genotype of H+H+ showed higher serum TG, apoB100 levels, TG/HDL-C ratio, preβ1-HDL, HDL3b and lower HDL2a, HDL2b compared with H-H- (P<0.05). In control group, the genotype of H+H+ had higher serum TG，HDL3c and lower HDL2a compared with H-H- (P<0.05). CONCLUSION: The HindⅢ polymorphism at intron 8 of LPL gene is associated with the general shift toward smaller size of HDL particle size in hyperlipoidemia, and the change of HDL subclasses distribution profile may be closely related to the pathogenesis of atherosclerosis in Chinese patients with hyperlipoidemia.     

Relationship between HDL subclass distribution and plasma glucose and lipid levels in patients with metabolic syndrome

AIM: To investigate high-density lipoprotein(HDL) subclass distribution and to analyze the relationship between HDL subclasses with plasma glucose and lipids in metabolic syndrome(MS). METHODS: Apolipoprotein 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 biochemical 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 HDL_3b were increased in the MS patients(P<0.05). Meanwhile, HDL-C, apoA-I and preβ₂-HDL, HDL_2a and HDL_2b were decreased in the MS patients(P<0.01). With the increase in the plasma glucose level, the contents of HDL_2a and HDL_2b 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 HDL_2b 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 HDL_2b had a decreasing 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 HDL_2b, 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 HDL_3b. 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 metabolism of HDL particles is disrupted.     

Relationship of subclasses of serum HDL and Apo A-Ⅰ gene polymorphism in hyperlipidemia

AIM: To investigate apolipoprotein A-Ⅰ gene (Apo A-Ⅰ) polymorphism and its relationship with serum HDL subclasses in patients with hyperlipidemia (HL). METHODS: Apo A-Ⅰ genotype was assayed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The subclasses of serum HDL in 118 patients with hyperlipidemia and 109 healthy subjects were determined by two-dimensional gel electrophoresis conjunction with immunodetection method. RESULTS: Both in HL group and the control group, G/G and C/C genotypes were the most frequent at －78 bp and ＋83 bp of Apo A-Ⅰ gene, respectively. The frequency of rare A allele at －78 bp in HL group was significantly higher than that in control group. In HL group, subjects with G/A mutation had higher serum levels of TG, Apo C-Ⅲ, pre β1-HDL and HDL3a, and lower levels of HDL2a and HDL2b compared to the subjects with G/G genotype. CONCLUSION: The G/A transition in the －78 bp position of the Apo A-Ⅰ gene promoter in patients with hyperlipidemia is associated with HDL subclasses. There is a general shift toward smaller sized HDL, which, in turn, indicates that HDL maturation might be abnormal.     

Relationship between the E-selectin and oxidative stress in patients with obese type 2 diabetes mellitus

AIM: To investigate the relationship between the levels of soluble E-selectin and oxidative stress in patients with obese type 2 diabetes mellitus.METHODS: The level of E-selectin, the contents of ox-LDL and malondialdehyde (MDA) and activities of superoxide dismutase (SOD) were measured in patients with obese and non-obese type 2 diabetes mellitus.RESULTS: The levels of E-selectin, ox-LDL and MDA were higher in patients with obese type 2 diabetes mellitus than those in control group (P<0.05), and the contents of HDL-C, HDL2-C and HDL3-C were significantly lower than those in control group (P<0.01).The activity of SOD in patients with obese type 2 diabetes mellitus was significantly lower than that in control group.The contents of E-selectin and MDA were more markedly elevated in patients with obese type 2 diabetes mellitus than those in patients with non-obese type 2 diabetes mellitus (P<0.01,P<0.05) and the activity of SOD was also significantly lower than that in patients with non-obese type 2 diabetes mellitus (P<0.01).There was significantly positive correlation between E-selectin and HbA1c, waist circumference, TC, ox-LDL, MDA (r=0.352, P<0.05;r=0.634, P<0.05;r=0.517, P<0.05;r=0.480, P<0.05;r=0.572, P<0.05), and negatively correlation between E-selectin and HDL3-C (r=-0.374, P<0.05).CONCLUSION: The plasma level of E-selectin is markedly elevated in patients with obese type 2 diabetes mellitus.E-selectin is possibly associated with oxidative stress.     

Changes of liver lipid metabolism-related PPAR-γ/LXR-α/ABCG1 pathways and inflammatory factors in atherosclerotic mice and role of Huayu-Qutan recipe

AIM To observe the changes of liver lipid metabolism-related peroxisome proliferator-activated receptor-γ (PPAR-γ)/liver X receptor-α (LXR-α)/ATP-binding cassette transporter G1 (ABCG1) signaling pathways and inflammatory factors in mice with atherosclerosis (AS), and to investigate the effects of Huayu-Qutan recipe (HYQT) on hepatic lipid metabolism and inflammatory response and the mechanisms. METHODS ApoE^-/- mice (n=24) were randomly divided into model group, HYQT group and simvastatin group, and C57BL/6J mice (n=8) were used as control group. Except for the control group, the mice in other groups were given high-fat diet. After 12 weeks of modeling, the mice in HYQT and simvastatin groups were intragastrically given the corresponding drugs, and the mice in control and model groups were given the same volume of normal saline. After 8 weeks, the serum levels of triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) were measured by an automatic biochemical analyzer. HE and oil red O staining was used to observe liver histopathological and lipid changes. The hepatic levels of free fatty acid (FFA), TG, tumor necrosis factor-α (TNF-α), Toll-like receptor 4 (TLR4) and interleukin-1β (IL-1β) were detected by ELISA. The protein expression of PPAR-γ, LXR-α and ABCG1 was determined by Western blot. RESULTS Compared with control group, the serum levels of TC, TG and LDL-C in model group were significantly increased (P<0.01), and the HDL-C content was significantly decreased (P<0.01). Liver steatosis, cell size augmentation and lipid deposition were obvious, and liver FFA and TG levels were significantly increased (P<0.01). The liver levels of TLR4, TNF-α and IL-1β were significantly increased (P<0.01), while the protein expression of PPAR-γ, LXR-α and ABCG1 was significantly decreased (P<0.05 or P<0.01). Compared with model group, the serum levels of TC, TG and LDL-C in simvastatin group and HYQT group were significantly decreased (P<0.05 or P<0.01), and the HDL-C content was significantly increased (P<0.01). Liver steatosis was weakened, and liver lipid deposition and FFA and TG levels were significantly decreased (P<0.05 or P<0.01). The liver levels of TLR4, TNF-α and IL-1β were significantly decreased (P<0.01), while the protein expression of PPAR-γ, LXR-α and ABCG1 was significantly increased (P<0.05 or P<0.01). CONCLUSION Huayu-Qutan recipe may exert anti-AS effect by regulating liver PPAR-γ/LXR-α/ABCG1 pathways and attenuating liver TRL4-mediated inflammatory responses.     

Effect of high fat diet on UCP2 mRNA expression in white adipose tissue of SR-A I/II gene knock-out mice

AIM:To observe the relationship between UCP2 mRNA expression in white adipose tissue and diet-induced obesity in SR-A I/II gene knock-out (SR-AⅠ/Ⅱ-/-) mice. METHODS:Fluorescent quantitative RT-PCR was used to detect UCP2 mRNA expression in mice epididymal white adipose tissue. The cellular morphological changes were analyzed by using image analysis. Serum TG, TC and LDL-C concentrations were measured by enzymatic determination. RESULTS:After fed with high fat diet for 12 weeks, average body weight of SR-A I/II-/- mice was much higher than that of wild type (SR-A I/II+/+) control mice (P<0.01), as well as the serum lipid (TG, TC, LDL-C) levels, epididymal fat pad weight, adipocyte area and diameter. UCP2 mRNA expression in white adipose tissue in SR-A I/II-/- mice was significant lower than that in SR-A I/II+/+ control mice (P<0.01). CONCLUSION:Abnormal UCP2 mRNA expression may be associated with SR-A I/II-/- mice susceptive to diet-induced obesity.     

Serum lipid levels and ApoB gene Xba I and 3'-VNTR polymorphisms in longevous elderly Han population in Zhejiang

AIM: To study the levels of serum lipids and the effects of apolipoprotein B (ApoB) gene Xba I-restriction fragment length polymorphism (RFLP) and 3'-variable-number tandem repeat (VNTR) polymorphism on serum lipid and apolipoprotein levels in longevous elderly Han population in Zhejiang. METHODS: Physical and laboratory examinations were performed on longevous elders, children of longevous elders, normal control people and children of non-longevous elders, and the Xba I-RFLP and 3'-VNTR polymorphism in ApoB gene were genotyped. RESULTS: The serum levels of triglyceride (TG), low-density lipoprotein cholesterol (LDL-C) and ApoB were negatively correlated with longevity (P<0.05), while the level of high-density lipoprotein cholesterol (HDL-C) was positively correlated with longevity (P<0.01). The levels of total cholesterol (TC), LDL-C and ApoB were higher and the HDL-C level was lower in the people with Xba I-RFLP X⁺X^- genotype than those in the people with Xba I-RFLP X^-X^- genotype (P<0.01). The levels of TC, TG, LDL-C and ApoB were higher and the HDL-C level was lower in the people with 3'-VNTR large allele than those in the people with 3'-VNTR minor allele (P<0.01). CONCLUSION: High TG, LDL-C and ApoB levels and low HDL-C level are not conductive to longevity. Serum lipid levels in the people with Xba I-RFLP X^-X^- genotype or 3'-VNTR minor allele are healthy and conductive to longevity.     

Effects of intranasal Escherichia coli on glucolipid metabolism in high-fat diet-induced obese mice

AIM: To study whether the pulmonary infection of Escherichia coli (E. coli) interferes the glucolipid metabolism in high-fat diet-induced obese mice. METHODS: High-fat diet-induced obese mice (n=48) and normal chow-fed control mice (n=48) were intranasally infused with 40 μL fluid containing 4×10⁹ CFUs E. coli. The serum, periepididymal adipose tissue and liver were obtained at 0 d, 1 d, 2 d, 3 d and 4 d after infection. The body mass, periepididymal adipose tissue and liver were weighed, and the levels of fasting blood glucose (FBG), fasting blood insulin (FINS), free fatty acid (FFA) and very-low-density lipoprotein (VLDL) were measured by ELISA. The serum total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C), and hepatic TG contents were detected, and the hepatic steatosis was observed under microscope with oil red O staining. RESULTS: Compared with day 0, the body mass, fat mass and fat index were decreased significantly from day 1 to day 4 after infection (P<0.05). The levels of FBG, FINS and HOMA-IR were apparently raised from day 2 to day 4 after infection (P<0.05). The contents of serum FFA, TG and VLDL were increased markedly from day 1 to day 4 after infection (P<0.05). However, the concentrations of serum TC, LDL-C and HDL-C were decreased obviously from day 1 to day 3 (P<0.05). The liver mass, liver index and TG content were significantly increased from day 1 to day 4 (P<0.05). Consistently, the lipid droplet accumulation in the liver cells was increased obviously at day 2 and day 4 after infection. Compared with control group, except the levels of serum TC, LDL-C and HDL-C in obese group substantially decreased, the other indexes were increased by different degrees during the whole experiment period (P<0.05). CONCLUSION: Pulmonary infection of Escherichia coli exacerbates the disorder of glucose and lipid metabolism in high-fat diet-induced obese mice, which contributes the development of insulin resistance and hepatic steatosis.     

Effect of ginsenoside Rb1 on liver cell pyroptosis in hyperlipidemia rats and its possible mechanism

AIM:To discuss the mechanism of ginsenoside Rb1 against liver lipid deposition by observing the effect of ginsenoside Rb1 on liver cell pyroptosis in hyperlipidemia rats. METHODS:Totally 32 healthy SPF rats were randomly divided into control group, model group, ginsenoside Rb1 group and simvastatin group. The rats in control group was given the basic feed, while the others were given high-fat diet. The rats in ginsenoside Rb1 group and simvastatin group were given corresponding drugs. The rats in control group and model group were intraperitoneal injected with equal volume of saline. Eight weeks later, the serum levels of triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) were tested by the automatic biochemistry analyzer. The pathological changes of the liver tissues were observed with HE staining. The protein and mRNA expression levels of pyroptosis-related factors NLRP3, caspase-1, IL-1β, IL-18 and GSDMD were detected by Western blot and RT-qPCR. RESULTS:Compared with control group, the serum levels of TC, TG and LDL-C in model group were increased significantly (P<0.01), and the HDL-C content was decreased significantly (P<0.05). The steatotic liver cells covered the visual field. The mRNA and protein expression levels of NLRP3, caspase-1, IL-1β, IL-18 and GSDMD were increased significantly (P<0.01). Ginsenoside Rb1 significantly decreased the serum levels of TC, TG and LDL-C (P<0.05), and significantly increased the content of HDL-C (P<0.01). Ginsenoside Rb1 also significantly decreased the degree of steatosis, and the number and size of lipid droplets. The mRNA and protein expression levels of NLRP3, caspase-1, IL-1β, IL-18 and GSDMD were decreased significantly (P<0.05 or P<0.01). CONCLUSION:Ginsenoside Rb1 atte-nuates liver injury and inhibits liver lipid deposition in hyperlipidemia rats by reducing the expression of hepatic pyroptosis-related factors.     

Liraglutide ameliorates liver injury of type 2 diabetic mice via micro-RNA-33-AMPK pathway

AIM: To observe the effects of liraglutide on the level of microRNA-33 (miR-33) and the expression of AMP-activated protein kinase (AMPK) and apoptosis-related proteins in mice with type 2 diabetes mellitus (T2DM), and to explore its possible mechanism. METHODS: High-fat diet and intraperitoneal injection of streptozocin were used to establish the type 2 diabetic model in C57BL/6 mice. The mice were randomly divided into 4 groups (n=15):in control group, the normal mice were subcutaneously injected with equivalent volume of saline; in model group, the T2DM mice were subcutaneously injected with equivalent volume of saline; in low-and high-dose liraglutide treatment groups, the T2DM mice were subcutaneously injected with 100 and 200 μg·kg^-1·d^-1, respectively. After 4 weeks of administration, the levels of FBG, TG, TC, HDL-C, LDL-C, ALT and AST were determined. HE staining was used to observe the pathological changes of the liver tissues. The protein level of cleaved caspase-3 in the liver tissue was detected by the technique of immunofluorescence. The protein levels of p-AMPK/AMPK and apoptosis-related proteins were detected by Western blot. The expression of miR-33 in the liver tissues was detected by real-time PCR. RESULTS: Compared with model group, the contents of FBG, TG, TC, LDL-C, ALT and AST were decreased significantly, while the content of HDL-C was increased significantly in low-dose liraglutide group and high-dose liraglutide group (P<0.05). The protein levels of phosphorylated AMPK and Bcl-2 were up-regulated significantly, and the expression of cleaved caspase-3 was down-regulated significantly (P<0.05). The level of miR-33 was decreased significantly (P<0.01). CONCLUSION: Liraglutide alleviates liver injury in type 2 diabetic mice, and the mechanism may be associated with reducing the level of miR-33 and increasing the phosphorylation of AMPK in the liver tissues, thereby inhibiting hepatocyte apoptosis.     

Association between apolipoprotein E polymorphism and lipid metabolism in patients with cerebral infarction

AIM:To study the relationship between ApoE polymorphism and lipid metabolism of patients with cerebral infarction. METHODS:ApoE phenotype was determined in 110 patients with cerebral infarction and 60 normal controls by isoelectric focusing and immunoblotting. The TC, TG and HDL-C levels in serum of these subjects were measured with enzymes methods, ApoA I and ApoB levels with rocket immunoelectrophoresis methods, ApoE and Lp(a) levels with ELISA methods. RESULTS:The differences of the ApoE polymorphism distribution and ApoE allele frequencies (P＜0.05) occurred between two groups. The frequence of ApoE ε4 allele in patients with cerebral infarction was significantly higher than those in the normal controls (P＜0.05). However, ApoE 3/3 phenotypes was significantly lower (P＜0.05). Comparison of values of serum lipid with various ApoE phenotyoe among patients with cerebral infarction revealed that there was correlation between ApoE polymorphism and TC(P＜0.05), TG(P＜0.05), HDL-C(P＜0.05), LDL-C(P＜0.05), ApoA I(P＜0.05), ApoB(P＜0.05), ApoE(P＜0.05)and Lp(a)(P＜0.05). Patients carrying ε4 were associated with increased TC, LDL-C, ApoB and Lp(a), while those with ε2 were assiociated with decreased TC, LDL-C, and ApoB. Patients carrying ε2 were associated with increased TG, HDL-C, ApoAⅠ, and ApoE.CONCLUSIONS:ApoEε4 allele was associated with the development of cerebral infarction. ApoE polyphorphism affects lipid metabolism of cerebral infarction patients.     

The impact of scavenger receptor class A typeⅠ/Ⅱ on lipid metabolism in mice

AIM: To investigate the impact of scavenger receptor class A type Ⅰ/Ⅱ(SR-A Ⅰ/Ⅱ) on the lipid metabolism in SR-A Ⅰ/Ⅱ gene deficient mice. METHODS: A probe of 660 bp fragment of SR-A Ⅰ/Ⅱ cDNA digested with PstⅠ and XhoⅠ from plasmid 122 was used to identify whether SR-A Ⅰ/Ⅱ had been knocked out in the tail DNA of the mutant(SR-/-) and control(SR+/+) mice by the method of Southern-blot analysis. The serum levels of triglycerides(TG), cholesterol(CH), low density lipoprotein(LDL), high density lipoprotein(HDL), apolipoprotein(Apo) A and ApoB of the mice fed with normal food and higher lipid food respectively were tested by biochemical method. RESULTS: The serum levels of LDL and body weights of group with SR-A Ⅰ/Ⅱ gene knocked out were higher than that of control group(P<0.05). Although the disorders of serum levels of LDL and body weights deteriorated after high lipid diet in both groups, the disorders in group of SR-/- were worse than those in control group(P<0.01). CONCLUSION: The results demonstrated that SR-A Ⅰ/Ⅱ were involved in the regulation of lipid metabolism, and SR-A Ⅰ/Ⅱ deficiency is harmful for removing LDL from blood circulation.     

Effect of puerarin on myocardial injury in KKAy diabetic mice

AIM:To observe the effect of puerarin on myocardial injury according to the time of occurrence of myocardial injury in the development of type 2 diabetic mice. METHODS: The serum levels of glucose (GLU), triglyceride (TG), total cholesterin (TC), low density lipoprotein-cholesterol (LDL-C) and high density lipoprotein-cholesterol (HDL-C) in 17-week, 20-week, 24-week, 28-week KKAy mice were detected by automatic biochemical methods. The apoptotic percentage of cardiomyocytes was examined by flow cytometry. The expressions of bax and bcl-2 mRNA in cardiomyocytes were detected by RT-PCR. Caspase-3 expression in cardiomyocytes was determined by immunohistochemical staining. RESULTS: Compared to normal control mice, not only GLU level increased, but also the levels of TG, TC, LDL-C, HDL-C in 20-week, 24-week and 28-week KKAy mice increased apparently (P<0.01). Apoptosis of cardiomyocytes in KKAy mice began to show up at 28-week. The expression of bax mRNA increased and expression of bcl-2 mRNA reduced. At the same time, the expression of caspase-3 increased. Puerarin obviously decreased the apoptotic percentage of cardiomyocytes, reduced the expression level of bax mRNA, improved the expression level of bcl-2 mRNA (P<0.01), inhibited the expression of caspase-3 (P<0.01). CONCLUSION:Myocardial injury exits in type 2 diabetic mice. Mitochondria apoptotic pathway might participate in the hurting course.     

RXRα agonist bexarotene inhibits atherosclerosis in ApoE-/- mice by regulating TGF-β1/Smad2 signaling pathway

AIM To observe the effect of retinoid X receptor α （RXRα） agonist bexarotene （Bex） on the proliferation of transforming growth factor β1 （TGF-β1）-induced vascular smooth muscle cells （VSMCs） and atherosclerosis in apolipoprotein E knockout （ApoE^-/-） mice, and to explore the underlying mechanism. METHODS Ten C57BL/6 mice were selected as normal control group, and 30 ApoE^-/- mice were randomly divided into 3 groups： ApoE^-/- group, ApoE^-/-+Bex5 （5 mg·kg^-1·d^-1 Bex） group and ApoE^-/-+Bex10 （10 mg·kg^-1·d^-1 Bex） group. Bex was intragastrically given once a day for 8 weeks. The levels of triglyceride （TG） and total cholesterol （TC） were determined by oxidase method, and select masking method was used to determine serum levels of low-density lipoprotein cholesterol （LDL-C） and high-density lipoprotein cholesterol （HDL-C）. The protein levels of TGF-β1, p-Smad2 and Smad2 were determined by Western blot. HE staining was used to observe the intima of the thoracic aorta. The VSMCs were cultured with tissue patch method, and the proliferation of VSMCs was measured by BrdU incorporation method. RESULTS The serum levels of TG, TC and LDL-C, and the expression of TGF-β1 and p-Smad2 in thoracic aorta in ApoE^-/- group were significantly higher than those in C57BL/6 group （P<0.01）. Bex increased p-Smad2 protein level in thoracic aorta in a dose-dependent manner, inhibited the intimal plaque formation and vascular medial proliferation, and decreased the plaque area in ApoE^-/- mice （P<0.01）. No significant difference in serum levels of TG, TC, HDL-C and LDL-C, and TGF-β1 and Smad2 expression in thoracic aorta among ApoE^-/- group, ApoE^-/-+Bex5 group and ApoE^-/-+Bex10 group was observed. TGF-β1 （0.1~10 μg/L） promoted the proliferation of VSMCs, while Bex （10^-9~10^-7 mol/L） inhibited TGF-β1 （5 μg/L）-induced proliferation of VSMCs in a concentration-dependent manner. Bex （10^-7 mol/L） synergistically promoted the protein level of p-Smad2 in VSMCs induced by TGF-β1 （P<0.01）, but inhibited TGF-β1-induced nuclear translocation of p-Smad2. CONCLUSION RXRα agonist Bex inhibits the formation of atherosclerosis in ApoE^-/- mice, and its mechanism may be related to the regulation of TGF-β1/Smad2 pathway.     

Effects of Shan He Jian Fei Granule on the expression of leptin,adiponectin and resistin in obese rats induced by high-fat feeding

AIM: To study the effects of Shan He Jian Fei Granule (SHJFG), a Chinese medicine, on weight-reduction and fat-decrease in adiposity rats, and to observe the changes of leptin, adiponectin and resistin. METHODS: After the models were prepared successfully, the rats were randomly divided into four groups: normal group, low dosage, middle dosage, high dosage and obesity control group. After 8 weeks interference with SHJFG, the weight and the naso-anal length of each rat was measured and Lees index were calculated. The levels of TG, TC, LDL, HDL and leptin in serum were carefully determined. The gene expressions of adiponectin and resistin in adipose tissues of rats were determined by RT-PCR. RESULTS: Compared to high-fat diet group, the body weights, the Lees indexes, the weight of fat tissues and levels of TG, TC, LDL and leptin in SHJFG groups significantly decreased (P<0.05). Adiponectin mRNA expression in SHJFG group significantly increased (P<0.05), and the resistin mRNA expression also significantly increased. CONCLUSION: SHJFG significantly decreases the body weight and the serum levels of TG, TC and LDL in obese rats. The effects of SHJFG in raising the mRNA expressions of adiponectin and resistin in fat tissues may be one of the main role that results in lowering body weight in obese rats.     

GLP-1 down-regulates mRNA expression of SOCS-3 and SREBP-1c in rats with nonalcoholic fatty liver disease

AIM: To investigate the effects of glucagon-like peptide-1(GLP-1) on mRNA expression of SOCS-3 and SREBP-1c in the rats with nonalcoholic fatty liver disease. METHODS: Male SD rats were randomly divided into normal control(NC) group, high fat(HF) group and HF+liraglutide(Lira) group. The rats in HF group and HF+Lira group were given high-fat diet for 16 weeks. After 12 weeks of high-fat diet feeding in HF+Lira group, Lira(600 μg·kg^-1·d^-1) was intraperitoneally injected for 4 weeks. At the end of the 16th week, the rats were killed. The pathological changes of the liver were observed under optical microscope. The serum levels of alanine aminotransferase(ALT), aspartate aminotransferase(AST), triglyceride(TG) and total cholesterol(TC) were detected by automatic biochemical analyzer. TG contents of liver were measured by GPO-PAP method. The fasting insulin(FINS) was determined by ELISA, and insulin resistance index was assessed by homeostasis mode assessment(HOMA-IR). The mRNA expression of SOCS-3 and SREBP-1c in the liver tissues was detected by RT-qPCR. RESULTS: Compared with NC group, HOMA-IR, TG of liver, and the serum levels of ALT, AST, TG, TC and FINS in HF group were obviously increased(P<0.01). Compared with HF group, HOMA-IR, TG of liver, and the serum levels of ALT, AST, TG, TC and FINS in HF+Lira group were all obviously decreased(P<0.05 or P<0.01). The mRNA expression of SOCS-3 and SREBP-1c in HF group was significantly higher than that in NC group(P<0.01). The mRNA expression of SOCSV3 and SREBP-1c in HF+Lira group was significantly decreased as compared with HF group(P<0.05). CONCLUSION: Liraglutide may improve the IR and reduce TG of liver through decreasing the mRNA expression of SOCS-3 and SREBP-1c, so as to play a therapeutic role in nonalcoholic fatty liver disease.     

Mast cells change cellular cholesterol content and inhibit cholesterol efflux from THP-1 macrophage-derived foam cells

AIM:Mast cells (MC) are present in the arterial intima,the site of atherogenesis. The present studies explore the effect of MC on cholesterol content,distribution and efflux in THP-1 macrophage-derived foam cells (THP-1FCs）. METHODS:THP-1FCs were incubated with high-density lipoproteins 3 (HDL₃) in the absence or presence of mast cell granules (MCGs) harvested from compound 48/80-stimulated rat peritoneal MC. The intracellular cholesterol level,cholesterol effluxing capacity,ATP-binding cassette transporter A1(ABCA1) mRNA and HDL₃ treated with MCGs were detected to characterize the role of MC on intracellular cholesterol. RESULTS:MCGs had high levels of cellular total cholesterol(TC),free cholesterol(FC) but not esterifed cholesterol(EC) compared to control group where the TC concentrations ranged from 527.3 mg/g to 917.9 mg/g cellular protein with EC accounting for 7.6% of the cholesterol. Cholesterol efflux was 14% less in MCGs group compared to control group. ABCA1 mRNA expression in MCG-treated THP-1FCs remained unchanged in 20 hours. In contrast,treatment of HDL₃ with MCGs resulted in rapid degradation of the main HDL₃ apoliproteins,apoA-Ⅰ. SDS-PAGE revealed that a minor polypeptide band with about 26 kD molecular mass appeared below the apoA-Ⅰband. Densitometric analysis of the gel demonstrated that ≈ 28% of apoA-Ⅰhad been degraded by the MCGs. CONCLUSION:These results indicate that MC decreases cholesterol efflux,increases cellular accumulation in TC and FC by depleting HDL₃ and apoA-Ⅰ,but not by inhibiting ABCA1 mRNA expression.