OBJECTIVETo investigate the possible effects of apolipoprotein A1 gene (APOA1) rs670 and rs5069 polymorphisms on plasma lipid profiles in healthy adolescents with different body mass index (BMI).

METHODSTotally 723 adolescents were divided into four groups according to their BMI: group 1[BMI =(17.80 ± 0.75)kg/m2], group 2[BMI = (19.39 ± 0.32) kg/m²], group 3[BMI = (20.68 ± 0.43) kg/m²], and group 4[BMI=(23.40 ± 2.05) kg/m²]. Height, weight, waist circumference, hip circumference, blood pressure, heart rate, plasma lipids, and blood glucose were determined, BMI and waist to hip ratio (W/H ratio) were calculated,and genome DNA was extracted for analyzing the genotypes of the APOA1 rs670 and rs5069 polymorphisms by polymerase chain reaction-restriction fragment length polymorphism.

RESULTSNo significant differences in height, weight, BMI, waist circumference, hip circumference, W/H ratio, blood pressure, heart rate, plasma lipids, and blood glucose between APOA1 rs670 or rs5069 genotypes were observed among group 1, group 2, and group 3. In group 4, A carriers of the rs670 polymorphism had significantly higher systolic blood pressure (P=0.017) and blood glucose levels (P=0.009) than the adolescents with the GG genotype. T carriers of the rs5069 polymorphism had significantly higher height (P=0.013), weight (P=0.011), and hip circumference (P=0.026) than the adolescents with the CC genotype.

CONCLUSIONSIn healthy adolescents with higher BMI, APOA1 rs670 polymorphism is associated with systolic blood pressure and blood glucose levels. The elevation of systolic blood pressure and blood glucose levels in A carriers of APOA1 rs670 polymorphism may be favorably modulated by weight loss.

Adolescent ; Apolipoprotein A-I ; genetics ; Body Mass Index ; Female ; Humans ; Lipids ; blood ; Male ; Polymorphism, Genetic

Apolipoprotein A-I-Milano(AIM), a natural variant, not only inhibits the initiation and progression of atherosclerosis, but also makes the preexisting atherosclerotic lesions regress. AIM gene, at which N-terminal codens were optimized, was subcloned into the expression vector of pET22b. Recombiant plasmids were transformed into E. coli strain BL21 (DE3) and induced with IPTG. The expressed apoliprotein A-I-Milano was soluble in E. coli and was about 38% of total cell lysate. Purified by Butyl Sepharose 4F. F hydrophobic chromatography and Q Sepharose H.P. anion exchange chromatography, followed by ultrafiltration with Vivaspin 20 (30 000MW), AIM monomer was obtained in a purity of more than 95%. Activity assay of binding of AIM monomer to lipid indicates that association of AIM monomer with DMPC is slower than normal apoA-I but DMPC number associated by AIM monomer is more than by apoA-I. This results will be important for studying structure, function of AIM, specially clinical application.
Apolipoprotein A-I ; biosynthesis ; genetics ; Escherichia coli ; genetics ; metabolism ; Humans ; Mutant Proteins ; biosynthesis ; genetics ; Recombinant Proteins ; biosynthesis ; genetics ; Solubility

OBJECTIVETo investigate associations between the apolipoprotein E-CI-CII gene cluster polymorphisms and coronary artery disease (CAD).

METHODSapoE genotypes were identified by multiplex amplification refractory mutation system (multi-ARMS) and the polymorphisms of both apoCI and apoCII genes were detected by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in 203 cases of CAD and 365 controls. Pairwise linkage disequilibrium coefficients (D, D') were estimated by the LINKAGE program.

RESULTSThe frequencies of apoE E3/4 genotype (0.259) and epsilon4 (0.139) in CAD group were significantly higher than that in control group (0.125, 0.069), (P<0.05). The significant difference was also found for the apoCI locus, the frequencies of H2 allele were 0. 205 in the CAD and 0.113 in the control. Linkage disequilibrium coefficient D' was 0.672 (P<0.01) between apoE and apoCI genes. Significant differences for a deficit of epsilon3-H1-T1 and excess of epsilon4-H2-T1 were found in the CAD by estimation of the haplotype frequencies. After adjustment for possible confounding factors, the multivariate Logistic analysis showed a significant interaction among epsilon4, H2 and smoking, OR value was 18.3 (95%CI:2.35-150.81, P<0.05), attributable proportions of interaction (API) was 57.3%, it was a multiplicative model. An additive model was shown among epsilon4, H2 and bibulosity; the odds ratio (OR) (95%CI) and API of their interaction were 12.7(2.8-58.6, P<0.05) and 43.5%, respectively.

CONCLUSIONThe results suggested that both apoE and apoCI on chromosome 19 were the susceptibility loci for CAD, their linkage disequilibrium should be responsible for the development of CAD. Smoking and bibulosity can significantly increase the risk of CAD.

Aged ; Alcohol Drinking ; Apolipoprotein C-I ; genetics ; Apolipoprotein C-II ; genetics ; Apolipoproteins E ; genetics ; Coronary Artery Disease ; genetics ; Female ; Gene Frequency ; Haplotypes ; Humans ; Linkage Disequilibrium ; Logistic Models ; Male ; Middle Aged ; Multigene Family ; genetics ; Polymorphism, Genetic ; genetics ; Risk Factors ; Smoking

OBJECTIVETo investigate the effects of a high-carbohydrate diet on the lipid and apolipoprotein ratios in healthy young adults with different genotypes of the polymorphism at -75 site in the promoter region of the gene of apolipoprotein AI (APOA1).

METHODSFifty-six subjects aged (22.89 +/- 1.80) years were given a wash-out diet for 7 days, followed by a high-carbohydrate diet for 6 days. The wash-out diet contained 15% protein, 31% fat, and 54% carbohydrate. The high-carbohydrate diet contained 15% protein, 15% fat, and 70% carbohydrate. Twelve-hour fasting serum lipids and apolipoproteins B100 and AI were measured on the mornings of the 1st, the 8th, and the 14th days from the beginning of the wash-out diet. The ratios of triglyceride (TG)/high-density lipoprotein cholesterol (HDL-C), total cholesterol (TC)/HDL-C, low-density lipoprotein cholesterol (LDL-C)/HDL-C, and apolipoprotein B100 (APOB100)/apolipoprotein AI (APOAI) were calculated. The genome DNA was extracted and the polymorphism of APOA1 -75 G/A was determined by polymerase chain reaction followed by restriction fragment length polymorphism assay.

RESULTSAt baseline, the lipid and apolipoprotein ratios showed no significant differences between the GG genotype and the A carriers in males (P > 0.05), whereas the female A carriers had a significantly higher ratio of LDL-C/ HDL-C compared with the female subjects with the GG genotype (P < 0.05). Following the high-carbohydrate diet, significant decreases of TC/HDL-C were found in all the groups, regardless of sex and genotype (P < 0.01). LDL-C/HDL-C experienced significant decreases in both the genotypes in males (P < 0.05), while in females, significant decrease of LDL-C/HDL-C was only observed in A carriers (P < 0.01).

CONCLUSIONThe A allele of the -75 G/A polymorphism in APOA1 may have specific effects on the LDL-C/HDL-C ratio in females.

Adult ; Apolipoprotein A-I ; genetics ; Apolipoproteins ; blood ; Dietary Carbohydrates ; metabolism ; Female ; Genotype ; Humans ; Lipids ; blood ; Male ; Polymorphism, Genetic ; Young Adult

Apolipoprotein A- I is the major apolipoprotein in high-density lipoprotein known to have a wide range of physiological functions, the best-studied one of which is in regulating cholesterol metabolism and preventing arteriosclerosis. Human blood has been the only source of this protein. To facilitate further research and application, it is essential to produce it through genetic engineering. In the current research, the baculovirus-insect cell system was used to overexpress human apolipoprotein A- I . Two recombinant baculoviruses were constructed. The first one expressed a pro form of apoA- I lacking native signal peptide. The recombinant protein was found to remain mainly inside cells in the early phase of infection, while being largely excreted to the medium late in infection. The second one used a heterologous signal peptide, snake phospholipase A2 inhibitor alpha subunit signal peptide, to lead the secretion of mature apoA- I. In contrast to the first virus, recombinant apoA- I was found in the culture medium at the early phase of virus infection. The mature apoA- I was purified from culture medium using Phenyl Sepharose hydrophobic interaction chromatography (HIC) and eluted with water and Propylene. This work shows that snake phospholipase A2 inhibitor a subunit signal peptide can be used to secret human apoA- I in insect cells, but the efficiency of its secretion is limited when the expression level is high.
Animals ; Apolipoprotein A-I ; genetics ; metabolism ; Baculoviridae ; genetics ; Blood Proteins ; genetics ; metabolism ; Blotting, Western ; Cell Line ; Chromatography ; Genetic Vectors ; genetics ; Humans ; Recombinant Proteins ; genetics ; metabolism ; Snakes ; Spodoptera ; cytology

Apolipoprotein AI (apo AI), the major protein component of human high-density lipoprotein (HDL), is a single-chain polypeptide of 243 amino acids. Several epidemiological studies have shown that the plasma concentrations of HDL has the role of reverse cholesterol transport (RCT) and inversely correlated with the incidence of coronary artery disease. Because apo AI lacks post-translational modifications, it is convenient to express human apo AI in Escherichia coli expression system. However, there is a poor stability of the mRNA and the apo AI protein in E. coli, it is difficult to express mature apo AI in recombinant bacteria, moreover, even as a fusion protein, apo AI is still sensitive to degradation and can not be cleaved efficiently from the fusion tags. In contrast, proapolipoprotein AI (proapo AI, having an additional polypeptide containing the amino acids Arg-His-Phe-Trp-Gln-Gln at the amino-teminal of the mature protein) proved stable and undegraded in Escherichia coli, and therefore, in this research, an expression system of E. coli including a plasmid of P(R)P(L) tandem promoter was adapted to produce proapo AI. Furthermore, site-directed mutagenesis of the proapo AI cDNA was performed to generate a Clu8Asp mutation in the amino-terminal sequence of proapo AI which created an acid labile Asp-Pro peptide bond between amino acid 8 and 9, and permitted specific chemical cleavage to remove pro-peptide. After inducing with a shift of temperature, yields of recombinant proapo AI achieved about 40% of total cell protein and the recombinant proapo AI expressed proved as a form of inclusion body in cells, so protein need to renature. First of all, the protein was dissolved in buffer with denaturant, and renaturation was carried out on a hydrophobic interaction column (Phenyl Sepharose), ion-exchange chromatography and gel-filtration chromatography were then used to further purify the protein. The purified recombinant apo AI was detected by a set of tests including Western-blotting, Circular dichroism spectra and lipid-binding test, the results shown that recombinant apo AI has similar structural and lipid-binding properties identical to those of native plasma apo AI, which facilitates further research and application.
Apolipoprotein A-I ; biosynthesis ; genetics ; Chromatography, Ion Exchange ; methods ; Escherichia coli ; genetics ; metabolism ; Humans ; Mutagenesis, Site-Directed ; Mutation ; Protein Precursors ; biosynthesis ; genetics ; Recombinant Proteins ; biosynthesis ; genetics ; isolation & purification

The work was aimed to investigate the differential expressions of lipid metabolism related genes in the early stage of atherosclerosis in the young apolipoprotein E deficient (apoE(-/-)) mice at different ages with normal chow diet. The genotypes of mice were identified by using multiplex polymerase chain reaction (multi-PCR) analysis. The semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) and real-time quantitative RT-PCR were used to analyze the expressions of lipid metabolism related genes in the liver of apoE(-/-) and age-matched wild type (WT) mice of 14-day old, 1-month old, 2-month old, 3-month old. The serum total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) contents were assayed using COD-PAP and GPO-PAP methods. The serum apolipoprotein B100 (apoB100) content was quantitated by immune turbidimetry. The hearts were perfusion-fixed in 4% formaldehyde, infiltrated with 30% gum sucrose for 24 h at 4 °C, and embedded in OCT compound. The aortic sinus tissues were serially sectioned at -15 °C, stained with Sudan IV, and counterstained with light green. The results were shown as follows. Compared with that in WT mice, the mRNA levels of apoA I and apoA IV in apoE(-/-) mice aged from 14-day old to 3-month old changed prominently (P<0.05), with apoA I up-regulated and apoA IV down-regulated. At the age of 1 month, the expression of apoB100 in apoE(-/-) mice was higher than that in WT mice (P<0.05). The expression of apoA V was up-regulated (P<0.05) and there was obvious lipid deposition in the aortic intima in apoE(-/-) mice at the age of 2 months. The expressions of fatty acid translocase (Fat/CD36) and angiopoietin-like protein 3 (Angptl 3) in apoE(-/-) mice were higher than those in WT mice at the age of 3 months (P<0.05), while the expressions of peroxisome proliferator-activated receptor α (PPARα), liver X receptor α (LXRα), carnitine palmitoyl transferase I (CPT I) and acyl coenzyme A oxidase 1 (ACOX1) showed no significant changes. The serum TC, TG, LDL-C and HDL-C contents in apoE(-/-) mice aged from 14-day old to 3-month old were higher than those in age-matched WT mice. apoE(-/-) mice showed a marked increase in serum apoB100 content, consistent with the trend of serum LDL-C content and apoB100 mRNA content in the liver. The results suggest that the mRNA expressions of apoA I, apoA IV, apoA V, apoB100 and Angptl 3 in apoE(-/-) mice change significantly compared with those in WT mice, and these genes might be relevant to the complicated lipid metabolism network, and involved in the early stage of atherogenesis.
Animals ; Apolipoprotein A-I ; metabolism ; Apolipoprotein B-100 ; blood ; Apolipoproteins A ; metabolism ; Apolipoproteins E ; genetics ; Atherosclerosis ; genetics ; Gene Expression ; Lipid Metabolism ; genetics ; Lipoproteins, HDL ; blood ; Lipoproteins, LDL ; blood ; Liver ; metabolism ; Mice ; Mice, Knockout ; Triglycerides ; blood

OBJECTIVETo investigate the effects of Apo A1 and B gene polymorphism on avascular necrosis of the femoral head (ANFH) in north Chinese Han population.

METHODSPolymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP) technique was used in samples of 143 cases with documented ANFH and 92 healthy control matched by age and sex individuals selected from north Chinese Han nationality. The studied loci include promoter region (-75bp) and the intron 1 (+83 bp) of Apo A1 gene, Eco RI,Xba I of Apo B gene; polymerase chain reaction was used to study 3'-VNTR of Apo B gene.

RESULTSAt -75 bp in promoter, the frequency of A/A genotype in ANFH group was significantly higher than that in control group (P < 0.01), while the frequency of G/A genotype in ANFH group was significantly lower than that in control group (P < 0.01). No difference was found in the frequency of genotype at +83bp in intron 1 of Apo A1 gene, Eco RI, Xba I and 3'-VNTR loci of Apo B gene.

CONCLUSIONApolipoprotein A1 gene A/A substitution at position -75 in promotor is associated with ANFH, the mutation may be one of the sensitive genes of ANFH, first reported inside and abroad. But no evident relationship was found between gene polymorphism of +75 bp loci of Apo A1 gene, Eco RI loci of Apo B gene, Xba I loci of Apo B gene or 3'-VNTR of Apo B gene and ANFH.

Adult ; Apolipoprotein A-I ; genetics ; Apolipoproteins B ; genetics ; Case-Control Studies ; China ; Electrophoresis ; Female ; Femur Head Necrosis ; genetics ; Gene Frequency ; Genotype ; Humans ; Male ; Polymorphism, Genetic

OBJECTIVETo investigate the relationship among -75 bp/+83 bp polymorphism in apolipoprotein A1 (apo A1) gene, lipids levels and the occurrence of coronary atherosclerosis disease (CAD).

METHODSWe determined distributions of two MspI polymorphisms of the apo A1 gene at -75 bp and +83 bp, and blood lipids levels among 137 Chinese patients (92 with CAD and 45 in the control group) in relation to circulating lipids and coronary angiography.

RESULTSThe demographic information for 137 subjects showed that subjects with CAD tended to have more unfavorable lipoprotein variables. Genotype distributions at both sites were different between the CAD and control groups. Furthermore, the control group had higher M1-/M2- frequencies than the CAD group (M1: P < 0.005; M2: P < 0.05) and the "M1-" (A) and "M2-" alleles were associated with increased high-density lipoprotein cholesterol (HDL-C) (M1-: P < 0.0001; M2-: P < 0.05) and apo A1 (M1-: P < 0.0001; M2-: P < 0.05) levels. "M1-" and "M2-" were significantly negatively correlated with CAD (P < 0.01 and P < 0.05, respectively).

CONCLUSIONSOur results suggest that changes from G to A at the -75 bp site and from C to T or G to A at the +83 bp site do increase circulating levels of apo A1 and HDL-C. And those individuals with these changes are likely to have a lower risk of developing CAD.

Apolipoprotein A-I ; blood ; genetics ; Case-Control Studies ; Cholesterol, HDL ; blood ; Coronary Artery Disease ; blood ; genetics ; Female ; Humans ; Lipids ; blood ; Male ; Middle Aged ; Polymorphism, Genetic

OBJECTIVE To investigate the relationship between the Nco I, Ava II polymorphism of low density lipoprotein receptor (LDL-R) gene in patients with the occurrence of atherosclerotic cerebral infarction (ACI) among the Han nationality in Liaoning province. METHODS The polymerase chain reaction technique was used to study the polymorphisms of LDL-R gene and allele frequencies in 77 patients with ACI and in 113 age-matched Chinese healthy controls. The levels of the lipid and lipoproteins were also compared among the cases with ACI and the controls. RESULTS A(+) frequencies of LDL-R gene in healthy controls and ACI group were 0.230 and 0.125 respectively, while the N(+) frequencies of healthy control and ACI group was 0.667 and 0.662 respectively. In case of the coexistence of A(-) A(-) and N(+) N(+), the relative risk (RR) of ACI was 5.56(P<0.001), while the RR of the increase of serum levels TG, TC, LDL-C, LP(a) were 4.29, 7.67, 9.33 and 3.09(P<0.05), respectively. CONCLUSION The coexistence of A(-) A(-) and N(+) N(+) can affect the concentration of lipid and lipoprotein and is in close relationship with the occurrence of ACI.
Apolipoprotein A-I ; blood ; Apolipoproteins B ; blood ; Binding Sites ; genetics ; Cerebral Infarction ; blood ; genetics ; Cholesterol ; blood ; Cholesterol, LDL ; blood ; DNA ; genetics ; metabolism ; Deoxyribonucleases, Type II Site-Specific ; metabolism ; Genotype ; Humans ; Intracranial Arteriosclerosis ; blood ; genetics ; Lipoproteins ; blood ; Receptors, LDL ; genetics ; Triglycerides ; blood