Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011860 (type 2 diabetes)
57,723 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Serum paraoxonase (PON) is a high-density lipoprotein-bound enzyme that can prevent oxidation of low-density lipoprotein by hydrolyzing lipid peroxides and thus exert an anti-atherogenic effect. Recent studies have suggested that glutamine(Q isoform)/arginine(R isoform) polymorphism at position 192 of PON(1) gene is associated with macrovascular disease of type 2 diabetes mellitus (T2DM). We re-investigated this relationship using carotid intima-media thickness (IMT) as a surrogate continuous variable for macroangiopathy. The genotype and allele frequency of PON(1) 192 Q/R polymorphism was assayed by polymerase chain reaction-restriction fragment length polymorphism in 152 type 2 diabetic patients and 128 healthy subjects from a population of Chinese Han nationality in ChengDu area. The carotid IMT was measured by B-mode ultrasonography in type 2 diabetic patients. No differences were found in PON(1) gene Q/R polymorphism in the type 2 diabetic patients when compared with the control group. The mean carotid IMT in type 2 diabetic subjects with the QQ, QR and RR genotype was 0.65+/-0.27, 0.83+/-0.27 and 1.05+/-0.32 mm, respectively. One-way ANOVA showed that IMT was significantly greater in the RR subgroup than in both QR and QQ subgroups (P<0.01). Multivariate logistic regression analysis showed R allele to be the main determinant of IMT variability (OR 4.0 95% CI 2.10-7.40 P=0.005). Our data support the view that 192 R allele of PON(1) gene is a risk factor for macrovascular disease of T2DM in Chinese.
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PMID:Gln-Arg192 polymorphism of paraoxonase 1 is associated with carotid intima-media thickness in patients of type 2 diabetes mellitus of Chinese. 1284 20

We investigated the effect of PON 55 and PON 192 polymorphisms on serum PON1 activity and lipid profiles in 213 non-insulin dependent diabetes mellitus (NIDDM) individuals and 116 non-diabetic controls among Turkish subjects. The distribution of PON 55/192 gene polymorphism was determined by polymerase chain reaction-based restriction fragment length polymorphism. Serum lipid levels were measured enzymically. PON activity was measured by spectrophotometric assay of p-nitrophenol production following addition of paraoxon. We found that PON 55 and 192 genotype distribution was similar in patients and controls and paraoxonase activity was generally lower in diabetics than in control subjects. We showed that PON 55 and 192 genotypes have a major effect on serum PON activity. PON 192 BB homozygotes had significantly higher PON activity than AA and AB genotypes among the control and NIDDM populations (p<0.001). PON 55 MM homozygotes had significantly lower PON activity than did LL and LM genotypes in control and NIDDM populations (p<0.05). The PON1 55 and 192 polymorphisms did not consistently influence the serum lipid profiles in either population. In conclusion, our results suggest that the paraoxonase activities are affected by PON1 genetic variability in Turkish NIDDM patients and controls.
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PMID:Paraoxonase 55 and 192 polymorphism and its relationship to serum paraoxonase activity and serum lipids in Turkish patients with non-insulin dependent diabetes mellitus. 1512 81

We have evaluated the possible association of polycystic ovary syndrome (PCOS) with 15 genomic variants previously described to influence insulin resistance, obesity, and/or type 2 diabetes mellitus. Seventy-two PCOS patients and 42 healthy controls were genotyped for 15 variants in the genes encoding for paraoxonase (three variants), plasma cell differentiation antigen glycoprotein, human sorbin and SH3 domain containing 1, plasminogen activator inhibitor-1, peroxisome proliferator-activated receptor-gamma2, protein tyrosine phosphatase 1B (two variants), adiponectin (two variants), IGF1, IGF2, IGF1 receptor, and IGF2 receptor. Compared with controls, PCOS patients were more frequently homozygous for the -108T variant in paraoxonase (36.6% vs. 9.5%; P = 0.002) and homozygous for G alleles of the ApaI variant in IGF2 (62.9% vs. 38.1%; P = 0.018). Paraoxonase is a serum antioxidant enzyme and, because -108T alleles result in decreased paraoxonase expression, this increase in oxidative stress might result in insulin resistance. G alleles of the ApaI variant in IGF2 may increase IGF2 expression, and IGF2 stimulates adrenal and ovarian androgen secretion. In conclusion, the paraoxonase -108 C-->T variant and the ApaI polymorphism in the IGF2 gene are associated with PCOS and might contribute to increased oxidative stress, insulin resistance, and hyperandrogenism in this prevalent disorder.
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PMID:Association of the polycystic ovary syndrome with genomic variants related to insulin resistance, type 2 diabetes mellitus, and obesity. 1518 Oct 35

The aim of this study was to determine whether the paraoxonase (PON1) status, i.e. PON1 activities and phenotypes (AA, AB and BB), and its relationship with lipid status are different in patients with type II diabetes as compared to healthy population. Diabetic group comprised 175 patients with type II diabetes mellitus (94 men and 81 women) who came to their regular control examination and took the oral glucose tolerance test. Patients with type II diabetes mellitus diagnosis for 12 years on average were on peroral antidiabetics, or insulin or diet, and 3 patients had no therapy prescribed yet. Control group comprised 114 apparently healthy individuals (28 men and 86 women) who were not on any medication. The paraoxonase activity was measured with 2.0 mmol L(-1) paraoxon in the absence and in the presence of 1.0 mol L(-1) NaCl, and with 2.0 mmol L(-1) phenylacetate. Both activities were measured spectrophotometrically at 37 degrees C in 0.1 mol L(-1) Tris-HCl buffer, pH = 8.0, containing 2.0 mmol L(-1) CaCl(2). Sera of diabetic and control subjects were assigned to the paraoxonase phenotypes on the basis of the basal paraoxonase activity distribution. We assigned 45% sera of male and 49% sera of female diabetic patients, and 64% sera of both genders of the control group to the AA low activity phenotype. There were no differences in paraoxonase activities between the gender- and phenotype-matched diabetic and control groups. Enzyme activity against the phenylacetate was higher, and phenotype-dependent, only in diabetic patients. In contrast to AA phenotype individuals, total cholesterol and LDL-cholesterol in the female diabetic group and triglyceride concentration in the male diabetic group assigned to pooled AB and BB phenotypes were higher than in the corresponding controls. It follows from PON1 phenotype distribution that less antiatherogenic paraoxonase B allele is more frequent in type II diabetes mellitus than in the healthy population. Their lipid status is more atherogenic, which could indicate a risk of premature atherosclerosis.
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PMID:Paraoxonase/arylesterase in serum of patients with type II diabetes mellitus. 1661 35

HDL protects against atherosclerosis development. Defective functioning of HDL in type 2 diabetes may be one cause of increased cardiovascular disease associated with type 2 diabetes. HDL modulates LDL oxidation through the action of paraoxonase-1 (PON1), which is one of the major mechanisms by which HDL is antiatherogenic. We have compared the ability of HDL from people with type 2 diabetes (n = 36) with no coronary heart disease (CHD) to metabolize oxidized palmitoyl arachidonyl phosphatidylcholine (ox-PAPC), a major product of LDL oxidation and a PON1 substrate, with that of HDL isolated from healthy control subjects (n = 19) and people with CHD but no diabetes (n = 37). HDL from people with type 2 diabetes metabolized 11% less ox-PAPC, and HDL from people with CHD metabolized 6% less, compared with HDL from control subjects (both P < 0.01). The ability of HDL from control and type 2 diabetic subjects containing the PON1-192RR alloform to metabolize ox-PAPC was significantly reduced compared with PON1-192QQ or QR genotypes (P < 0.05). The defective ability of HDL to metabolize ox-PAPC was reflected in a significant increase in circulating plasma oxidized LDL concentration in the two patient groups (37 +/- 5, 53 +/- 7, and 65 +/- 7 mmol/l for control, CHD, and type 2 diabetic subjects, respectively; P < 0.001), with PON1-192RR genotype carriers having the highest concentrations. In the control group, there was a significant negative correlation between serum PON1 activity and oxidized LDL concentration (r = 0.856, P < 0.001); however, this correlation was not evident in the patient groups. HDL from type 2 diabetic subjects without CHD had a decreased ability to metabolize oxidized phospholipids, which could lead to increased susceptibility to develop cardiovascular disease.
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PMID:Defective metabolism of oxidized phospholipid by HDL from people with type 2 diabetes. 1706 48

Genetic predisposition has been implicated in the development of coronary heart disease (CHD). We made a molecular scanning of several genetic polymorphisms to see whether they are associated with CHD in Japanese patients with type 2 diabetes mellitus. Among several polymorphisms, only a polymorphism of paraoxonase gene was confirmed to be associated with CHD in this population. This polymorphism seems to be important in the development of CHD in Japanese as well as in Caucasian population.
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PMID:Molecular scanning of susceptibility genes for the development of coronary heart disease in Japanese. 1715 May 27

Eucommia ulmoides Oliver (Du-zhong) leaf extract was investigated for its antioxidant effects in type 2 diabetic animals, C57BL/KsJ-db/db mice. Du-zhong extract equivalent to 1% dried whole Du-zhong leaf (0.187 g of extract/100 g of diet) was added to the experimental diets for 6 weeks. The Du-zhong extract supplement significantly lowered blood glucose concentrations and elevated plasma paraoxonase activity compared with the control group. The activities of erythrocyte superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) were significantly higher in the Du-zhong group compared with the control group, while glutathione reductase (GR) activity was not different between groups. The activities of SOD, GSH-Px, and GR in liver and kidney were not affected by Du-zhong extract supplementation, whereas the CAT activity was significantly higher in the Du-zhong group than in the control group. Du-zhong extract supplementation resulted in lower levels of hydrogen peroxide and lipid peroxide in erythrocytes, liver, and kidney. These results suggest that the antioxidant activity of Du-zhong extract is potentially beneficial for the prevention and management of complications of type 2 diabetes.
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PMID:Eucommia ulmoides Oliver leaf extract increases endogenous antioxidant activity in type 2 diabetic mice. 1720 32

The metabolic syndrome is a common and complex disorder combining obesity, dyslipidemia, hypertension, and insulin resistance. It is a primary risk factor for diabetes and cardiovascular disease. We showed for the first time that the metabolic syndrome is associated with a higher fraction of oxidized LDL and thus with higher levels of circulating oxidized LDL. Hyperinsulinemia and impaired glycaemic control, independent of lipid levels, were associated with increased in vivo LDL oxidation, as reflected by the higher prevalence of high oxidized LDL. High levels of oxidized LDL were associated with increased risk of future myocardial infarction, even after adjustment for LDL-cholesterol and other established cardiovascular risk factors. This association is in agreement with the finding that accumulation of oxidized LDL, which activates/induces subsets of smooth muscle cells and macrophages to gelatinase production, was associated with upstream localization of a vulnerable plaque phenotype. Dyslipidemia and insulin resistance in obese LDL receptor-deficient mice were associated with increased oxidative stress and impaired HDL-associated antioxidant defence associated with accelerated atherosclerosis due to increased macrophage infiltration and accumulation of oxidized LDL in the aorta. The accumulation of oxidized LDL was partly due to an impaired HDL-associated antioxidant defence due to a decrease in PON. Our data in this experimental model are thus the more relevant because a decrease in PON activity was found to be associated with a defective metabolism of oxidized phospholipids by HDL from patients with type 2 diabetes. Weight loss in leptin-deficient, obese, and insulin-resistant mice was associated with expressional changes of key genes regulating adipocyte differentiation, glucose transport and insulin sensitivity, lipid metabolism, oxidative stress and inflammation, most of which are under the transcriptional control of PPARs. We established an important relationship between PPAR-gamma and SOD1 for the prevention of the oxidation of LDL in the arterial wall. For example we showed that rosuvastatin decreased the oxidized LDL accumulation by increasing the expression of PPAR-gamma and SOD1. In addition, we established a relation between increased PPAR-alpha expression in the adipose tissue and a change in the gene expression pattern, which explains the decrease of free fatty acids, triglycerides and the increase in insulin sensitivity. We demonstrated that plaque oxidized LDL correlated with coronary plaque complexity in a swine atherosclerosis model. Oxidized LDL correlated positively with the expression of IRF1 and TLR2 suggesting a relation between oxidative stress and inflammation in coronary atherosclerotic plaques. Oxidized LDL induced further the expression of TLR2 and IRF1 in macrophages in vitro suggesting a causative link. As in the mouse model described above, plaque oxidized LDL correlated negatively with SOD1 expression and ox-LDL inhibited the expression of SOD1 in macrophages in vitro. We showed that TLR2, CXCR4 and MYC are overexpressed in monocytes of obese women at high cardiovascular risk and that weight loss was associated with a concomitant decrease of their expression. This suggests that the transcription factor cMYC has an atherogenic effect by inducing pro-inflammatory genes. The increased expression of TLR2 and CXCR4 were observed in the absence of an increase in ox-LDL but in the presence of an increase in SOD1. Interestingly, the expression of SOD1 correlated also with that of MYC, suggesting that it has an atherogenic effect by inducing the expression of an anti-oxidant enzyme. How ox-LDL prevents this increase remains to be determined. How we plan to do this is explained in the next part. In aggregate, our studies contributed to a better understanding of the relationships between metabolic syndrome, insulin signalling, oxidative stress and inflammation and atherosclerosis. We identified paraoxonase, interferon regulatory factor-1, toll-like receptors, CXCR4 and SOD1 as possible targets for intervention.
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PMID:Relations between metabolic syndrome, oxidative stress and inflammation and cardiovascular disease. 1866 60

Association of paraoxonase 1 (PON1) with high-density lipoprotein (HDL) stabilizes the enzyme. In diabetic patients, PON1 dissociates from HDL and, as a consequence, is less biologically active. Our aim was to investigate the effects of Wonderful variety pomegranate juice (WPJ) and pomegranate polyphenol extract (WPOMxl) consumption on PON1 association with HDL in diabetic patients. Thirty patients with type 2 diabetes mellitus participated in the study. Ten male patients and 10 female patients received concentrated WPJ (50 mL/day for 4 weeks), while another group of 10 male patients received WPOMxl (5 mL/day for 6 weeks). There were no significant effects of WPJ or WPOMxl consumption on fasting blood glucose or hemoglobin A1c levels. After 4 weeks of WPJ consumption by male patients, basal serum oxidative stress was significantly decreased by 35%, whereas serum concentrations of thiol groups significantly increased by 25%. Moreover, HDL-associated PON1 arylesterase, paraoxonase, and lactonase activities increased significantly after WPJ consumption by 34-45%, as compared to the baseline levels. PON1 protein binding to HDL was significantly increased by 30% following WPJ consumption, and the enzyme became more stable. In male patients that consumed WPOMxl and in female patients that consumed PJ, a similar pattern was observed, although to a lesser extent. We conclude that WPJ as well as WPOMxl consumption by diabetic patients does not worsen their diabetic parameters. Furthermore, WPJ as well as WPOMxl consumption contribute to PON1 stabilization, increased association with HDL, and enhanced catalytic activities. These beneficial effects of pomegranate consumption on serum PON1 stability and activity could lead to retardation of atherosclerosis development in diabetic patients.
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PMID:Consumption of wonderful variety pomegranate juice and extract by diabetic patients increases paraoxonase 1 association with high-density lipoprotein and stimulates its catalytic activities. 1875 51

Diabetes mellitus is a multifactorial metabolic disease, caused by the complete or relative absence of insulin hormone, which results in the deterioration of carbohydrate, protein, and lipid metabolism. The PON1 55 and 192 polymorphisms have been reported to be associated with type 2 diabetes and its complications. In this study, the involvement of the PON1 55 and 192 polymorphisms and paraoxonase enzyme activity in diabetic complications was assessed. The MM and QQ genotypes were the most frequent in complications of type 2 diabetes in both of the polymorphisms. PON enzyme activity was lower in the type 2 diabetes group with respect to the control group. Regarding both genotypes and enzyme activity, correlations were found between the PON1 55 and 192 genotypes and diabetic complications. This study thus helps to outline a genotype-phenotype relation for the PON1 gene in a Turkish population.
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PMID:PON1 55 and 192 gene polymorphisms in type 2 diabetes mellitus patients in a Turkish population. 2082 Sep 4


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