BACKGROUNDOxidative stress such as low-density lipoprotein (LDL) oxidation is thought to be an important mechanism in Alzheimer's disease (AD). Paraoxonase 1 (PON1), an enzyme located on high-density lipoprotein, can prevent LDL from oxidation to some extent. It is also a potent cholinesterase inhibitor and an arylesterase, combating organophosphate poisoning and metabolization of environmental neurotoxins which might be responsible for neurodegeneration with aging. We evaluated the association of Gln192Arg polymorphism in the PON1 gene with AD in a Chinese Han ethnic population.

METHODSPatients and age-matched controls were recruited from outpatient clinics and a population-based epidemiological survey, respectively. Gln192Arg polymorphism in the PON1 gene was detected by allele-specific PCR technique in 521 patients with AD and 578 healthy controls.

RESULTSThe presence of at least one of PON1 R alleles (Q/R or R/R) was lower in AD patients than in the controls (82.7% vs 87.4%; chi(2) = 4.68, P = 0.03). PON1 gene R allele frequency was lower in AD patients than in the controls (60.7% vs 64.7%; chi(2) = 3.85, P = 0.05). One-way ANOVA showed that PON1 genotype had no effect on the age of onset for developing AD. Logistic regression analysis demonstrated the age and sex-adjusted odds ratio (OR) for the risk of AD in PON1 of PON1 R allele carriers was 0.71 (P = 0.044, 95% CI, 0.51 - 0.99).

CONCLUSIONOur results indicate that Gln192Arg polymorphism in the PON1 gene is associated with AD, and PON1 R allele might be a protective factor for AD in a Chinese Han ethnic population.

Aged ; Aged, 80 and over ; Alzheimer Disease ; genetics ; Aryldialkylphosphatase ; genetics ; China ; ethnology ; Female ; Genotype ; Humans ; Male ; Middle Aged ; Polymorphism, Single Nucleotide

We constructed an expression cassette of the organophosphorus pesticide degrading (opd) gene under the control of the E8 promoter. Then opd was transformed into tomato fruit using an agroinfiltration transient expression system. beta-Glucuronidase (GUS) staining, reverse transcription-polymerase chain reaction (RT-PCR), wavelength scanning, and fluorescent reaction were performed to examine the expression of the opd gene and the hydrolysis activity on coumaphos of organophosphorus hydrolase (OPH) in tomato fruit. The results show that the agroinfiltrated tomato fruit-expressed OPH had the maximum hydrolysis activity of about 11.59 U/mg total soluble protein. These results will allow us to focus on breeding transgenic plants that could not only enhance the degrading capability of fruit and but also hold no negative effects on pest control when spraying organophosphorus pesticides onto the seedlings in fields.
Aryldialkylphosphatase ; genetics ; physiology ; Coumaphos ; pharmacology ; Insecticides ; pharmacology ; Lycopersicon esculentum ; genetics ; metabolism ; Plants, Genetically Modified ; Promoter Regions, Genetic

OBJECTIVETo investigate the association between the C311S polymorphism of paraoxonase 2 (PON2) gene and ischemic stroke in Chinese type 2 diabetes mellitus (T2DM) patients.

METHODSA case-control study of 279 Chinese subjects (including 162 T2DM with or without ischemic stroke and 117 non-diabetic control) was performed. Genotype frequencies of C311S polymorphism were studied by polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP) analysis with DdeI digestion.

RESULTSC311S polymorphism of PON2 gene was detected in Chinese with the C/S allele frequencies 0.145 and 0.855. The frequency distribution showed significant difference between Chinese and Asian Indian. Furthermore, the genotype distribution (SS, CS and CC) of the PON2 C311S gene polymorphism exhibited a significant difference between T2DM patients complicated with ischemic stroke and T2DM without ischemic stroke, the former had a significantly higher C allele frequency(P<0.05).

CONCLUSIONThe above data indicate that the polymorphism at codon 311(Cys --> Ser)in the PON2 gene is associated with ischemic morbidity in Chinese T2DM patients and C allele might be a risk factor.

Adult ; Aryldialkylphosphatase ; genetics ; Asian Continental Ancestry Group ; genetics ; Diabetes Mellitus, Type 2 ; complications ; genetics ; Female ; Humans ; Male ; Middle Aged ; Polymorphism, Genetic ; Stroke ; etiology ; genetics

OBJECTIVETo study the relationship between single nucleotide polymorphisms of paraoxonase 2 (PON2) and stroke.

METHODSObjects examined comprised of three groups: 120 healthy people, 150 patients with cerebral hemorrhage, 180 patients with cerebral infarction. The PON2 genotypes were determined with PCR and digested by specific restriction enzymes.

RESULTSC311S and G148A polymorphisms of PON2 gene existed among population of Chinese Hunan area, with the allele frequencies 0.23/0.77 for C/S and 0.57/0.43 for G/A in the control group. There was no significant difference of genotype and allele frequency between stroke patients and controls (P>0.05).

CONCLUSIONC311S polymorphism of PON2 has no significant correlation with stroke in Han people of Chinese Hunan area and allele C/S is not an independent risk factor for stroke,neither is G148A.

Aged ; Aryldialkylphosphatase ; genetics ; Asian Continental Ancestry Group ; genetics ; Case-Control Studies ; Female ; Humans ; Male ; Middle Aged ; Polymerase Chain Reaction ; Polymorphism, Single Nucleotide ; Stroke ; genetics

OBJECTIVETo study the associations between paraoxonase, 55 Met/Leu (PON1 55 Met/ Leu), paraoxonase2 148 Ala/Gly (PON2 148 Ala/Gly) and manganese superoxide dismutase 9 Ala/Val (MnSOD 9 Ala/Val) genetic polymorphisms and coronary heart disease (CHD), plasma activities of paraoxonase (PON), total superoxide dismutase (T-SOD), MnSOD, as well as plasma concentration of maleic dialdehyde (MDA).

METHODSUsing PCR-RFLP method to identify genotype of PON1 55 Met/Leu, PON2 148 Ala/Gly and MnSOD 9 Ala/Val genetic polymorphisms, and using colorimetry to detect plasma activities of PON, T-SOD, MnSOD and plasma concentration of MDA in 262 CHD patients and 100 controls.

RESULTSCompared with controls, the plasma activities of PON [(349.27 +/- 138.36 vs. 454.75 +/- 166.00) nmol x min(-1) x ml(-1), P < 0.001], T-SOD [(23.61 +/- 16.51 vs. 44.01 +/- 22.68) U/ml, P < 0.001] and MnSOD [(21.56 +/- 13.11 vs. 28.79 +/- 8.65) U/ml, P < 0.001] reduced obviously,while plasma MDA concentration increased markedly [(2.47 +/- 0.73 vs. 2.15 +/- 0.55)nmol/ml, P < 0.01] in CHD patients. There were more LM genotype and Met allele of PON, 55 Met/Leu (24.8% vs. 1.4%, P < 0.001 and 12.4% vs. 0.5%, P = 0.001, respectively), GG and AG genotype and G allele of PON2 148 Ala/Gly (11.8% vs. 5.0%, P < 0.001, 48.1% vs. 24.0%, P < 0.001 and 36.0% vs. 17.0%, P < 0.001, respectively) and AA genotype, A allele of MnSOD 9 Ala/Val genetic polymorphisms (64.2% vs. 43.0%, P = 0.001 and 80.0% vs. 67.0%, P = 0.014, respectively) in CHD patients than in controls. The activities of plasma PON and T-SOD were lower in individuals with PON1 55 LM genotype than those with LL genotype. The activity of plasma PON was also lower in individuals with PON2 148 GG/AG genotype than those with AA genotype. The activities of plasma PON and MnSOD depressed in individuals with MnSOD AA genotype compared with those with VV genotype. Logistic regression analysis demonstrated that PON1 55 LM genotype, PON2 148 GG/AG genotype and G allele were independent risk factors for CHD.

CONCLUSIONThe antioxidative ability decreased, while lipid superoxide increased in CHD patients. Gene polymorphisms of PON1 55 Met/Leu, PON2 148 Ala/Gly and MnSOD 9 Ala/Val seemed to involve in the morbidity of CHD by influencing the plasma activities of PON and MnSOD.

Aryldialkylphosphatase ; genetics ; metabolism ; Case-Control Studies ; China ; Coronary Disease ; enzymology ; genetics ; Genotype ; Humans ; Polymerase Chain Reaction ; Polymorphism, Genetic ; Polymorphism, Restriction Fragment Length ; Superoxide Dismutase ; genetics ; metabolism

BACKGROUNDThe oxidative modification of low-density lipoprotein in the artery wall is currently believed to be central to the pathogenesis of atherosclerosis. Paraoxonase (PON1), an enzyme located on high-density lipoprotein (HDL), can prevent low-density lipoprotein (LDL) from oxidation at a certain extent. Recent studies show two other members of paraoxonase gene family, PON2 and PON3, possess antioxidant properties similar to PON1. The aim of the present study was to explore the role of PON gene cluster on coronary heart disease (CHD) in Chinese Han women.

METHODSSeven polymorphisms including PON1 -107C > T, -162G > A, -831G > A, R160G, Q192R, PON2 S311C, and PON3 -133C > A were genotyped in 184 female patients with CHD and 239 female controls. The plasma PON1 activity toward phenylacetate was determined in 50 cases and 50 controls randomly selected.

RESULTSThe plasma PON1 activities were significantly lower in cases than in controls. Individual SNP analysis showed that cases had significantly higher frequencies of PON1 -107T, -831G and PON2 311S alleles than controls. The genotype distributions of -107C > T were also significantly different between two groups. The odds ratios for the development of CHD were 1.66 for -107TC carriers and 2.0 for -107TT carriers, compared with -107CC carriers. Haplotype analyses showed that the distributions of haplotypes comprised of PON1 -107C > T and PON2 S311C were significantly different between cases and controls, with cases having higher frequency of T-S haplotype (44.8% vs. 36.3%, P = 0.013). The T-S haplotype remained significantly associated with CHD after adjusting environmental risk factors (P = 0.0069).

CONCLUSIONSThis association study suggested that lower plasma PON1 activity increased the risk of CHD in Chinese women, which may be mediated by the higher frequency of -107T allele in cases. Haplotype analyses indicated that there might be some synergistic effects between the PON1 -107C > T and PON2 S311C polymorphisms.

Adult ; Aged ; Aryldialkylphosphatase ; genetics ; Asian Continental Ancestry Group ; genetics ; China ; Coronary Disease ; enzymology ; ethnology ; etiology ; genetics ; Female ; Haplotypes ; Humans ; Middle Aged ; Multigene Family ; Polymorphism, Single Nucleotide

OBJECTIVETo investigate the effect of interaction between paranoxonase 1 (PON1)gene polymorphism and ATP-binding cassette transporter 1 (ABCA1) genetic variation on serum lipid level.

METHODSPolymerase chain reaction-restricted fragments length polymorphism was used to determine PON1 A/B192 and ABCA1R219K genotype of 1019 subjects, including 680 patients with strokes and 339 healthy individuals as controls.

RESULTSNo significant association between A/B192 genotype and any of the lipid measurements was detected. The levels of HDL-C in the subjects with RR, RK and KK genotypes showed a significant upward tendency respectively (P < 0.05); the levels of their triglyceride (TG) tended downward respectively, but there were no significant differences between them. The relationship between R219K genotype and serum lipid level was modified by A/B192 genotype. The levels of HDL-C in the subjects with AA/RR genotype and BB/KK genotype [(1.41 +/- 0.40) mmol/L, (1.41 +/- 0.39) mmol/L] were significantly different from that in the subjects with BB/RR genotype [(1.28 +/- 0.36) mmol/L] (P < 0.05).

CONCLUSIONThe result exhibited an interaction of PON1 A/B192 and ABCA1 R219K on serum lipid level.

ATP-Binding Cassette Transporters ; genetics ; Aged ; Aryldialkylphosphatase ; genetics ; Base Sequence ; Female ; Genotype ; Humans ; Lipids ; blood ; Male ; Middle Aged ; Polymerase Chain Reaction ; Polymorphism, Genetic ; genetics ; Sequence Analysis, DNA

OBJECTIVETo investigate the relationship between paraoxonase (PON) polymorphisms and serum homocysteine thiolactone (HTL) and coronary heart diseases.

METHODIn this prospective study, serum complex of HTL levels using ELISA, and the lever of serum Hcy using high pressure liquid chromatography (HPLC), determined the PON1/T(-107)C and PON2/C311S genotypes using PCR-restriction fragment length polymorphisms 203 were measured in patients with angiographic documented coronary heart disease (CAD) and 117 controls.

RESULTSSerum levels of Hcy and the complex of HTL in CAD patients were significantly higher than that in controls (P < 0.05). No significant difference was found in frequencies of PON1/T(-107)C genotypes and alleles (P > 0.05) between CAD patient and controls. The PON2/C311S (SS) genotype was lower in CAD patients than that in controls (P < 0.05), while the frequency of allele was similar between the two groups (P > 0.05). The T allele of PON1/T(-107)C and S alleles of PON2/C311S polymorphism were associated with lower plasma Hcy and HTL complex [Hcy (11.83 +/- 4.76) micromol/L vs (15.32 +/- 10.32) micromol/L, P < 0.05; HTL complex (24.36 +/- 9.30) U/ml vs (32.05 +/- 10.44) U/ml, P < 0.05]. The genetype PON2 and allele C were higher in CAD patients with type 2 diabetes than that in CAD patients without type 2 diabetes and controls (P < 0.005).

CONCLUSIONSThe elevation of serum Hcy and the complex of HTL were associated with increased risk of coronary heart disease. The allele PON1/(-107)T and PON2/311S might be protective for the development of atherosclerosis.

Adult ; Aged ; Aryldialkylphosphatase ; genetics ; Coronary Disease ; blood ; complications ; genetics ; Cysteine ; blood ; Diabetes Mellitus, Type 2 ; complications ; Female ; Homocysteine ; analogs & derivatives ; blood ; Humans ; Male ; Middle Aged ; Polymorphism, Genetic

Methyl parathion hydrolase (MPH) is a novel member of organophosphorus hydrolase. In this study, mpd gene was expressed in Escherichia coli DH5alpha with its native promoter. MPH was purified to homogeneity. Results show that metal-chelating compounds cannot inhabit the enzyme activity. Inductively Coupled Plasma-Atomic Emission Spectrometry analysis showed that MPH is a zinc-containing enzyme, the Zinc to enzyme molar ratio is near 2:1. In order to investigate critical residues related to enzymatic activity of MPH, chemical modification reagents EDC, DEPC, butanedione and pyridoxal were tested. Experiment results suggested that aspartate, glutamate, arginine and lysine are not important for enzyme activity. But DEPC, which can modify histidine residue, inactivate the enzyme activity greatly, and the inactivation rate is 9.6 h(-1). This result reflects that histidine residues are essential for enzyme activity. All these results provide basic data for MPH structure and molecular evolution research.
Aryldialkylphosphatase ; chemistry ; Enzyme Activation ; drug effects ; Escherichia coli ; genetics ; metabolism ; Histidine ; chemistry ; Phosphoric Monoester Hydrolases ; chemistry ; Recombinant Fusion Proteins ; biosynthesis ; chemistry ; genetics

OBJECTIVETo detect the single nucleotide polymorphisms of clopidogrel metabolism related genes (CYP2C19, ABCB1 and PON1) in Chinese patients with acute coronary syndrome (ACS) by genotype analysis.

METHODSGenetic analysis was performed in patients admitted to Fuwai Hospital from 2005 to 2008 with ACS within 4 weeks. The detection of polymorphisms was performed by TaqMan real-time PCR method. The alleles genotyped were CYP2C19 *2-*8, *17, ABCB1 C3435T, PON1 Q192R and PON1 L55M. Minor allele frequency (MAF) was calculated. Patients were classified as one of the 5 categories by clopidogrel metabolizer phenotypes as extensive [without any "loss-of-function" (LOF) allele *2-*8 or "gain-of-function" (GOF) allele *17], intermediate (with only one LOF allele), Poor (with two or more LOF alleles), ultra (with one or two GOF alleles) or unknown (with one LOF allele and one GOF allele).

RESULTSA total of 2800 ACS patients were enrolled [mean age (59.0 ± 12.3) years and 2236 males (79.9%)]. There were 74% patients with ST-segment elevation myocardial infarction (STEMI, n = 2072), 22.0% patients with non-ST-segment elevation myocardial infarction (NSTEMI, n = 617) and 4.0% patients with unstable angina (UA, n = 111). The minor allele frequency (MAF) for each genotype of CYP2C19 *2, *3, *4, *17 was 28.7%, 4.6%, 0.1% and 1.2%, respectively. There was no LOF allele *5-*8 in the study population. The MAF for ABCB1 C3435T, PON1 Q192R and PON1 L55M was 39.4%, 37.8% and 4.4%, respectively. Clopidogrel metabolizer groups were defined as extensive in 41.7%, intermediate in 45.6%, poor in 10.3%, ultra in 1.9% and unknown in 0.6% patients, respectively. There were no significant differences for all genotypes between males and females. Total LOF carriers of CYP2C19 were 56.4% and GOF carriers were 2.5%.

CONCLUSIONSOur study demonstrated a high distribution of the LOF allele of CYP2C19 in China ACS population.

Acute Coronary Syndrome ; genetics ; metabolism ; Aged ; Alleles ; Aryl Hydrocarbon Hydroxylases ; genetics ; Aryldialkylphosphatase ; genetics ; Asian Continental Ancestry Group ; genetics ; Cytochrome P-450 CYP2C19 ; Female ; Gene Frequency ; Genotype ; Humans ; Male ; Middle Aged ; Polymorphism, Single Nucleotide ; Ticlopidine ; analogs & derivatives ; metabolism