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Biomedical subjects

Shu Ye

Publications and source records attributed to Shu Ye.

At least 19 recordsLinked to original sources
PubMed2006

Separation and on-line concentration of saponins from Panax notoginseng by micellar electrokinetic chromatography.

A simple, reproducible and sensitive micellar electrokinetic chromatography (MEKC) method was developed for the separation and determination of 10 saponins from Panax notoginseng. Field-enhanced sample injection with reverse migrating micelles (FESI-RMM) was used for on-line concentration of the saponins. The effects of concentrations of sodium dodecyl sulfate (SDS) and organic modifier, the sample matrix, the injection time of water plug, the injection voltage and injection time of sample on the separation and stacking efficiency were investigated. The optimum buffer contained 10mM H3PO4, 140 mM SDS, 20% acetonitrile and 15% 2-propanol and the pH of buffer was 2.4. The sample solution was diluted with 15 mM SDS and injected for 15s with -8 kV after injection of 2s water plug. Under the optimum conditions, the analytes were well separated with very high plate number (8.0 x 10(5)-1.2 x 10(6) N/m); the limits of detection of the analytes were 1.7-6.3 microg/mL. The high sensitivity permitted the determination of two minor saponins Rh1 (1.01 mg/g) and Rg2 (0.62 mg/g) in P. notoginseng, which were not determined in the literature.

Chromatography, Micellar Electrokinetic Capillary↗
PubMed2005

Haplotype effect of the matrix metalloproteinase-1 gene on risk of myocardial infarction.

Myocardial infarction (MI) is commonly caused by atherosclerotic plaque rupture following excessive degradation of collagen fibers in the atherosclerotic lesion. We investigated whether interindividual variability in risk of MI was related to polymorphisms in the gene encoding matrix metalloproteinase (MMP)-1, a key fibrillar collagen-degrading enzyme. Several single nucleotide polymorphisms in the MMP1 gene promoter were identified following sequencing DNA samples from 30 individuals. An analysis of the polymorphisms in a cohort of British whites with coronary atherosclerosis, including 639 patients with MI and 538 non-MI subjects, revealed a haplotype effect of the -519A>G and -340T>C polymorphisms on risk of MI, with the A(-519)-C(-340) and G(-519)-T(-340) haplotypes being protective (odds ratio=0.70 [0.57 to 0.86]; P=0.0007), whereas the G(-519)-C(-340) haplotype increased MI risk (odds ratio=1.94 [1.15 to 3.28]; P=0.013). This finding was replicated in a subsequent analysis of 387 Swedish MI patients and 387 healthy controls (odds ratio=0.70 [0.55 to 0.89], P=0.003, for A(-519)-C(-340) and G(-519)-T(-340); odds ratio=1.54 [0.97 to 2.46], P=0.07, for G(-519)-C(-340)). In vitro assays showed that compared with the A(-519)-T(-340) haplotype, the A(-519)-C(-340) and G(-519)-T(-340) haplotypes had lower promoter activity, whereas the G(-519)-C(-340) haplotype had greater promoter strength, in driving gene expression in human macrophages. Haplotype-specific differences in MMP1 mRNA level in atherosclerotic tissues were also detected. The data indicate that MMP1 gene variation is a genetic factor contributing to interindividual differences in MI risk.

Adult↗
PubMed2005

Influence of matrix metalloproteinase genotype on cardiovascular disease susceptibility and outcome.

Data have been accumulating that indicate that matrix metalloproteinase (MMP) gene polymorphisms contribute to inter-individual differences in susceptibility to and outcome of cardiovascular disease. This is currently best exemplified by the MMP3 gene 5A/6A polymorphism which has an effect on MMP3 expression and has been shown to be associated with coronary stenosis, myocardial infarction, coronary artery calcification, post-angioplasty coronary restenosis, carotid atherosclerosis, stroke, arterial stiffness, and blood pressure. Functional polymorphisms in the MMP1, MMP2, MMP7, MMP9, MMP12, and MMP13 genes have also been related to coronary artery disease, arterial stiffness, and/or abdominal aortic aneurysm. These genetic findings support the notion that MMPs play important roles in the pathogenesis of these conditions. There is also some evidence suggesting that MMP genotyping could aid in identifying patients who are likely to have unfavourable prognosis and/or adverse response to treatment.

Cardiovascular Diseases↗
PubMed2005

Variation in the toll-like receptor 4 gene and susceptibility to myocardial infarction.

Variation in the gene encoding toll-like receptor 4 (TLR4), a transmembrane receptor that mediates inflammatory responses to bacterial endotoxin, has been associated with susceptibility to atherosclerosis and its complications, such as myocardial infarction (MI), the pathogenesis of which involves inflammation. A recent study has also indicated that TLR4 gene variation influences the effect of statin treatment on reducing atherosclerosis complications. We studied the TLR4 gene Asp299Gly polymorphism in relation to susceptibility to myocardial infarction in a cohort of patients with angiographically documented coronary artery disease, and performed a meta-analysis using data sets from three independent studies. The meta-analysis showed that overall, odds ratio (OR) for MI was 0.73 [95% confidence interval (CI) 0.55-0.96, P=0.024] in 299Gly carriers compared to non-carriers, and there was no evidence of heterogeneity among the sample sets (P=0.679). In our patient cohort, a significant association of 299Gly bearing genotypes with lower susceptibility to myocardial infarction was observed only in patients receiving statin treatment, with 299Gly carriers having an OR of 0.49 (95% CI 0.27-0.78, P=0.015) for MI compared to non-carriers. These results are consistent with the notion that variation in the TLR4 gene contributes to inter-individual variability in susceptibility to coronary ischaemic events, and that TLR4 genotype and statin treatment may have a synergistic effect.

Aged↗
PubMed2005

CYP2A6, MAOA, DBH, DRD4, and 5HT2A genotypes, smoking behaviour and cotinine levels in 1518 UK adolescents.

OBJECTIVES: Smoking is a major cause of death and often initiates in adolescence. Mutations in CYP2A6 slow metabolism of nicotine to cotinine. Haploinsufficiency in adults is associated with lower cigarette consumption, lower cotinine level and higher quit rates. Other genes are also implicated in smoking behaviour. We explored smoking behaviour and cotinine levels in relation to genotypes in adolescents. METHODS: 1518 subjects from the Ten Towns Heart Health Study were genotyped for CYP2A6 alleles *1A, *1B, *2, *4, *5, *9 and *12 to classify predicted nicotine metabolism rate. DBH(rs77905), MAOA(rs1801291+VNTR), DRD4(VNTR) and 5HT2A(rs6313) were also studied. Smoking status was established by questionnaire and salivary cotinine measurement at 13-15 and 18 years. RESULTS: No significant associations were identified for DBH, MAOA, DRD4 and 5HT2A markers, with smoking status or cotinine level at either age. At age 18, haploinsufficiency (HI) for CYP2A6 was associated with a higher odds of being a current smoker compared with the *1B carriers (WT1B) (OR = 2.23 (1.16, 4.27) for current versus ex); *1A homozygotes (WT1A) were also at slightly higher risk (OR = 1.44 (1.01, 2.06)). Partial haploinsufficiency (PHI) was not associated with being a current smoker. There were no significant associations at age 13-15. PHI and HI were associated with higher cotinine levels amongst smokers at both 13-15 and at 18 years compared with WT1B and WT1A groups. CONCLUSIONS: CYP2A6 haploinsufficiency increases likelihood of continuing smoking in teenagers. We hypothesize an explanatory 'occupancy' model to explain why haploinsufficiency results in faster progression to nicotine dependence, but lower subsequent consumption.

Adolescent↗
PubMed2005

Mutation scanning by meltMADGE: validations using BRCA1 and LDLR, and demonstration of the potential to identify severe, moderate, silent, rare, and paucimorphic mutations in the general population.

We have developed a mutation-scanning approach suitable for whole population screening for unknown mutations. The method, meltMADGE, combines thermal ramp electrophoresis with MADGE to achieve suitable cost efficiency and throughput. The sensitivity was tested in blind trials using 54 amplicons representing the BRCA1 coding region and a panel of 94 unrelated family breast cancer risk consultands previously screened in a clinical diagnostic laboratory. All 10 common polymorphisms, 15/15 previously identified disease-causing mutations, and three previously untested single base changes were identified. Assays of LDLR exons 3 and 8 were validated in 460 familial hypercholesteremics and detected 8/9 known variants. We then applied the exon 3 assay in several DNA banks representing approximately 8000 subjects with known cholesterol values and applied both assays in one DNA bank (n = 3600). In exon 3 we identified one previously reported moderate mutation, P84S (n = 1), also associated with moderate hypercholesteremia in this subject; an unreported silent variant, N76N (n = 1); and known severe hypercholesteremia splice mutation 313+1G-->A (n = 2). Around exon 8 we identified a paucimorphism (n = 35) at the splice site 1061-8T-->C (known to be in complete linkage disequilibrium with T705I) and unreported sequence variants 1186+11G-->A (n = 1) and D335N G-->A (n = 1). The cholesterol value for D335N was on the 96.2 percentile and for T705I, 2/35 carriers were above the 99th percentile. Thus, variants with predicted severe, moderate, and no effect were identified at the population level. In contrast with case collections, CpG mutations predominated. MeltMADGE will enable definition of the full population spectrum of rare, paucimorphic, severe, moderate (forme fruste), and silent mutations and effects.

Breast Neoplasms↗
PubMed2004

Genotypic effect of the -565C>T polymorphism in the ABCA1 gene promoter on ABCA1 expression and severity of atherosclerosis.

OBJECTIVE: Loss-of-function mutations of the ATP-binding cassette transporter A1 (ABCA1) gene cause Tangier disease, a rare genetic disorder with accumulation of lipid-laden macrophages and increased risk of atherosclerosis. Common variants of this gene may be a genetic factor for atherosclerosis in the general population. This study was performed to test the reported association between the -565C>T polymorphism and atherosclerosis severity and to investigate whether this variant per se had an effect on promoter activity of the ABCA1 gene. METHODS AND RESULTS: A cohort of patients with coronary atherosclerosis were genotyped for the -565C>T polymorphism. Logistic regression analyses showed that homozygotes of the -565T allele had greatest mean number of diseased coronary arteries, particular in nonsmokers. Real-time reverse-transcriptase polymerase chain reaction showed that in atherosclerotic plaques removed from patients undergoing endarteretomy, ABCA1 expression levels were lowest in those who had the T/T genotype and highest in those of the C/C genotype. Transfection and reporter assays demonstrated that in cultured macrophages, the -565T allelic promoter had a lower activity in driving gene expression than the -565C allelic promoter. Electrophoretic mobility shift assays displayed differential binding of nuclear proteins to the 2 alleles. CONCLUSIONS: These results indicate that the -565C>T polymorphism has an allele-specific effect on ABCA1 gene expression and provide further evidence of a genotypic effect on coronary atherosclerosis severity. The study showed that the ABCA1 gene -565C>T polymorphism was associated with severity of coronary atherosclerosis in a cohort of patients from Southern England and that this sequence variant per se had an effect on promoter activity of the ABCA1 gene. The data support the notion that common ABCA1 gene variants can contribute to interindividual variability in atherosclerosis susceptibility and severity.

ATP Binding Cassette Transporter 1↗
PubMed2004

Differences in matrix metalloproteinase-1 and matrix metalloproteinase-12 transcript levels among carotid atherosclerotic plaques with different histopathological characteristics.

BACKGROUND AND PURPOSE: Previous studies have shown that atherosclerotic lesions express a number of matrix metalloproteinases (MMPs). Here we investigated whether transcript levels of MMP-1, -3, -7, -9, and -12 in carotid atherosclerotic plaques were correlated with histological features and clinical manifestations. METHODS: Atherosclerotic plaques (n=50) removed from patients undergoing carotid endarterectomy were classified histologically using a system proposed by Virmani et al, and MMP-1, -3, -7, -9, and -12 transcript levels in these tissues were quantified by real-time reverse-transcriptase polymerase chain reaction. RESULTS: Compared to plaques with a thick fibrous cap, those with a thin cap had a 7.8-fold higher MMP-1 transcript level (P=0.006). MMP-3, -7, and -12 were 1.5-fold, 1.8-fold, and 2.1-fold, respectively, higher in thin cap plaques, but the differences did not reach statistical significance. MMP-12 transcript levels were significantly increased in ruptured plaques compared with lesions without cap disruption (P=0.001). MMP-9 transcript levels were similar among the different types of lesion. MMP-1 and -12 transcript levels were significantly higher in plaques from patients with amaurosis fugax, than in those from asymptomatic patients (P=0.029 and P=0.008 for MMP-1 and MMP-12, respectively), than in those from patients with stroke (P=0.027 and P=0.001, respectively), and than in those from patients with transient ischemic attack (P=0.046 and P=0.008, respectively). CONCLUSIONS: These data support a role of MMP-1 and -12 in determining atherosclerotic plaque stability.

Aged↗
PubMed2004

Human evidence that the cystatin C gene is implicated in focal progression of coronary artery disease.

OBJECTIVE: Overexpression of elastolytic cysteine and aspartic proteases, known as cathepsins, is implicated in atherogenesis. The potential significance of imbalance in expression between cathepsins and their inhibitor cystatin C in cardiovascular disease has been highlighted by the demonstration of cystatin C deficiency in human atherosclerosis and abdominal aortic aneurysms. METHODS AND RESULTS: We identified and characterized physiologically relevant polymorphisms in the promoter region of the cystatin C gene that influence cystatin C production and used these polymorphisms as a tool to examine the significance of cystatin C in coronary atherosclerosis in vivo in humans. Seven polymorphisms, all in strong-linkage disequilibrium, were identified in the cystatin C gene, of which 2 promoter polymorphisms (-82G/C and -78T/G) were functional in vitro in electromobility shift and transient transfection assays. Genotyping of 1105 individuals (237 survivors of a first myocardial infarction before age 60 and 2 independent groups comprising a total of 868 healthy individuals) revealed that the plasma cystatin C concentration was significantly lower in carriers of the mutant haplotype. Furthermore, the mutant haplotype was associated with a higher average number of stenoses per coronary artery segment in unselected postinfarction patients (N=237) undergoing routine coronary angiography. CONCLUSIONS: These results provide human evidence for an important role of cystatin C in coronary artery disease.

Alleles↗
PubMed2004

Late life metabolic syndrome, early growth, and common polymorphism in the growth hormone and placental lactogen gene cluster.

Low rates of fetal and infant growth are associated with the metabolic syndrome and cardiovascular disease in later life. We investigated common genetic variation in the GH-CSH gene cluster on chromosome 17q23 encoding GH, placental lactogens [chorionic somatomammotropins (CSH)], and placental GH variant in relation to fetal and infant growth and phenotypic features of the metabolic syndrome in subjects aged 59-72 yr from Hertfordshire, UK. Allele groups T, D1, and D2 of a locus herein designated CSH1.01 were examined in relation to GH-CSH single nucleotide polymorphisms and to specific phenotypes. Average birth weights were similar for all genotype groups. Men with T alleles were significantly lighter at 1 yr of age, shorter as adults, and had higher blood pressures, fasting insulin (T/T 66% higher than D2/D2) and triglyceride concentrations, and insulin and glucose concentrations during a glucose tolerance test. Birth weight and 1-yr weight associations with metabolic syndrome traits were independent of the CSH1.01 effects. Common diversity in GH-CSH correlates with low 1-yr weight and with features of the metabolic syndrome in later life. GH-CSH genotype adds substantially to, but does not account for, the associations between low body weight, at birth and in infancy, and the metabolic syndrome.

Aged↗
PubMed2003

Microarray analysis of peroxisome proliferator-activated receptor-gamma induced changes in gene expression in macrophages.

We used a combination of expression microarray and Northern blot analyses to identify target genes for peroxisome proliferator-activated receptor (PPAR) gamma in RAW264.7 macrophages. PPARgamma natural ligand 15-deoxy-Delta(12,14) prostaglandin and synthetic ligands ciglitazone and rosiglitazone increased the expression of scavenger receptor CD36 and ATP-binding cassette transporter A1, as well as adipophilin (a lipid droplet coating protein involved in intracellular lipid storage and transport), calpain (a protease implicated in ABCA1 protein degradation), and ADAM8 (a disintegrin and metalloprotease protein involved in cell adhesion). These findings are relevant to understanding the effect of PPARgamma activation on gene expression and cognate pathways in macrophages.

Animals↗
PubMed2003

Influences of matrix metalloproteinase-3 gene variation on extent of coronary atherosclerosis and risk of myocardial infarction.

OBJECTIVES: The aim of this study was to assess matrix metalloproteinase-3 (MMP3) gene variation in relation to the degree of coronary atherosclerosis and risk of myocardial infarction (MI) in patients with coronary artery disease. METHODS: In this study, we systematically screened the promoter and coding regions for sequence variants. All polymorphisms identified were analyzed in 1,240 individuals undergoing coronary angiography. Functional analyses of the polymorphisms were carried out with the use of report assays and electrophoretic mobility shift assays. RESULTS: Six novel polymorphisms were identified. The 6A/6A genotype was associated with greater number of coronary arteries with significant stenosis (odds ratio [OR] 1.52, p = 0.008), whereas the 5A/5A and 5A/6A genotypes were associated with increased risk of MI (OR 2.02 and 1.78, p = 0.016 and 0.032, respectively). A stepwise logistic regression analysis with all polymorphisms taken into account showed that the effect of MI susceptibility was largely attributed to the 5A/6A polymorphism. In a stepwise logistic regression analysis with all haplotypes as independent variables, the most common haplotype (T-5A-A-A-G-A), and two rare haplotypes, all containing the 5A allele, were associated with MI susceptibility. Functional studies showed that the T-5A-A-A-G-A haplotype had a higher promoter activity in macrophages. CONCLUSIONS: These data indicate that the effect of MMP3 gene variation is attributable to the 5A/6A polymorphism and that individuals carrying the 6A/6A genotype may be predisposed to developing atherosclerotic plaques with significant stenosis, whereas those carrying the 5A allele may be predisposed to developing unstable plaques.

Aged↗
PubMed2003

Haplotypic analysis of the MMP-9 gene in relation to coronary artery disease.

Matrix metalloproteinase-9 (MMP-9) plays an important role in the pathogenesis of atherosclerosis, the pathology underlying the majority of coronary artery disease. We previously identified several polymorphisms in the gene encoding MMP-9. In this study we tested the hypothesis that variation in the matrix metalloproteinase-9 gene influences the development of atherosclerosis. Three common polymorphisms, i.e. -1562C>T, R+279Q and +6C>T, were analysed in 1510 white subjects undergoing coronary angiography. Analyses of individual polymorphisms showed that the frequencies of the C/T and T/T genotypes of the -1562C>T polymorphism were significantly higher in patients with coronary stenosis than in those with a normal angiogram. Logistic regression analyses indicated that individuals carrying the -1562T allele had an approx. 1.5-fold higher risk of developing coronary stenosis (OR 1.49, 95% CI 1.039-2.144), which was equivalent to an over 30% reduction in risk of coronary stenosis in individuals not carrying this allele (OR 0.670, 95% CI 0.467-0.963). The three polymorphisms studied were found to be in strong linkage disequilibrium. Haplotype analyses showed that the C-G-C haplotype (-1562C, +279Q and +6C) was associated with a protective effect against atherosclerosis. Individuals carrying this haplotype were at reduced risk of developing coronary stenosis (OR 0.695, 95% CI 0.530.92). Furthermore, the C-G-C haplotype was associated with less severe coronary atherosclerosis, i.e. carriers of this haplotype were at a lower risk of having coronary stenosis in more than one coronary artery (OR 0.796, 95% CI 0.640.99). These data, together with the previous finding that the -1562T allele has a higher transcriptional activity than the -1562C allele, support the notion that genetic variation with an effect on MMP-9 expression influences the development and progression of atherosclerosis.

Case-Control Studies↗
PubMed2003

TLR4 Asp299Gly polymorphism is not associated with coronary artery stenosis.

UNLABELLED: Inflammation and innate immunity may play a role in the pathogenesis of atherosclerosis. The Asp299Gly polymorphism in the toll-like receptor 4 (TLR4) gene reduces responsiveness to lipopolysaccharide and has been associated with reduced incidence and slower progression of carotid atherosclerosis. We analyzed this polymorphism in relation to susceptibility to and severity of coronary artery disease. METHODS: 1400 participants (mean age: 63 years, 31% female) in the Southampton Atherosclerosis Study were genotyped for the TLR4 Asp299Gly polymorphism using the tetra-primer PCR method. RESULTS: There was no significant difference between the frequencies of the Asp/Gly or Gly/Gly genotypes combined, compared to the Asp/Asp genotype, in patients with 0, 1, 2 or 3 coronary arteries with >50% stenosis (chi2(3 d.f.)2=0.4, P=0.94). No associations were observed between genotype groups and cardiac risk factors (P>0.05). CONCLUSION: The findings of this study do not support the hypothesis that the TLR4 Asp299Gly polymorphism influences predisposition to and progression of coronary artery disease.

Coronary Stenosis↗
PubMed2003

Variation in the matrix metalloproteinase-1 gene and risk of coronary heart disease.

AIMS: Matrix metalloproteinase-1 (MMP-1), a proteolytic enzyme able to degrade types I and III collagens, is present in atherosclerotic lesions but absent from the normal blood vessel wall. The recent observation that, in a transgenic mouse model, MMP-1 gene expression slows the development and progression of atherosclerotic plaques suggests that it may play a role in human atherogenesis. We investigated whether coronary heart disease was associated with a functional polymorphism in the human MMP-1 gene. In addition, we examined a polymorphism in the human MMP-3 gene that was previously reported to be associated with progression of coronary atherosclerosis. METHODS AND RESULTS: We genotyped 471 Caucasian men and women, aged 66-75 years, from Sheffield, UK, for the 1G/2G polymorphism in the MMP-1 gene and the 5A/6A polymorphism in the MMP-3 gene and ascertained the prevalence of coronary heart disease. People homozygous for the more transcriptionally active 2G allele of the MMP-1 gene had a reduced risk of coronary heart disease (OR 0.5, 95% CI 0.3 to 0.9) compared to people homozygous for the less transcriptionally active 1G allele. Heterozygotes had an intermediate risk (OR 0.7, 95% CI, 0.5 to 1.1). We found no association between the 5A/6A polymorphism in the MMP-3 gene and risk of coronary heart disease. CONCLUSION: Sequence variants at the MMP-1 genomic locus may influence risk of coronary heart disease in humans.

Aged↗
PubMed2003

Molecular pathogenesis of subarachnoid haemorrhage.

Subarachnoid haemorrhage (SAH) results from leakage of blood into the subarachnoid space and carries high morbidity and mortality. However, there is limited understanding to date, of the risk factors, cellular, intermediate biochemical and genetic traits predisposing to SAH. Nevertheless, in conjunction with improved methods of diagnostic imaging and less invasive approaches to preventing aneurysmal rupture, there may be utility in gaining a better understanding of the pathogenesis and in identifying pre-disease markers. Additionally, it is not impossible that drugs of value (e.g. matrix or endothelial modifiers) could become available. Several different clinical subtypes can be recognised, distinguished by arterial or venous involvement, presence of unruptured arterial aneurysms, and apparently "sporadic" and "familial" occurrences. Epidemiological risk factors include alcohol consumption and smoking: hypertension is a risk factor for rupture. About 10% seem to reflect strong family history and this subset may be particularly illuminating with respect to the molecular pathogenesis. Haemodynamic stress and poor vascular structure may be the main mechanisms of pathogenesis. The epidemiological and statistical evidence for familial megaphenic genes and modifier genes is reviewed. This review focuses on the pathogenesis, as opposed to inflammatory response to SAH. It sets in context the roles of specific genes and their protein products, such as polycystin (PKD1), fibrillin (FBN1), collagen III (COL3A1), elastin (ELN), collagen IV, protease inhibitor or alpha1-antitrypsin (PI) and proteases. These considerations illustrate the shortfalls in current knowledge, the needs of future biochemical and cellular research and their potential implications for future prevention of this often fatal condition.

Animals↗