Yazan: admin Tarih: Kas 30th, 2010 | Kategori::
PON1
Biochem Genet. 2010 Sep 7.
Ergun MA, Yurtcu E, Demirci H, Ilhan MN, Barkar V, Yetkin I, Menevse A.
Department of Medical Genetics, Gazi University Faculty of Medicine, Besevler, 06500, Ankara, Turkey, ergun@tr.net.
Abstract
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.
Yazan: admin Tarih: Şub 25th, 2010 | Kategori::
Paraoxonase
Turk Kardiyol Dern Ars. 2009 Oct;37(7):473-8.
Taşkiran P, Cam SF, Sekuri C, Tüzün N, Alioğlu E, Altintaş N, Berdeli A.
Department of Medical Biology and Genetics, Medicine Faculty of Celal Bayar University, Manisa, Turkey.
OBJECTIVES: Paraoxonase (PON1) is a high-density lipoprotein (HDL)-associated esterase that hydrolyses lipoperoxides. PON1 serves as a protective factor against oxidative modification of LDL, suggesting that it may play an important role in the prevention of atherosclerotic process. Research has focused on two polymorphisms: leucine (L allele) to methionine (M allele) substitution at codon 55, and glutamine (A allele) to arginine (B allele) substitution at codon 192. STUDY DESIGN: We examined amino acid changes at codon 55 and 192 in the PON1 gene by polymerase chain reaction and using restriction enzymes in 120 patients (92 men, 28 women; mean age 48.2+/-4.3 years) with premature coronary artery disease (CAD) and in 102 healthy subjects (80 men, 22 women; mean age 46.8+/-5.2 years) with no history of CAD and a normal electrocardiogram. RESULTS: Distribution of genotypes in the patient and control groups at codon 55 were 6.7% and 4.9% for MM, 46.7% and 29.4% for LM, 46.7% and 65.7% for LL, respectively. The frequency of genotypes at codon 192 were as follows: 4.2% and 2% for RR, 40% and 35.3% for QR, and 55.8% and 62.8% for QQ, respectively. While the frequency of PON1 55M allele was higher in the CAD group (0.3 vs. 0.2), PON1 192R allele frequency did not differ (p>0.05). There was a significant relationship between the PON1 M/L55 polymorphism and CAD (p=0.017), whereas the R/Q192 polymorphism was not associated with CAD (p=0.445). CONCLUSION: These data suggest that the PON1 M/L55 polymorphism shows a significant relationship with CAD and the Q/R192 polymorphism is not a major risk factor causing susceptibility to CAD in our population.
Yazan: admin Tarih: Tem 12th, 2009 | Kategori::
Paraoxonase
Folia Biol (Praha). 2009;55(2):35-40
Isbilen E, Yilmaz H, Arzu Ergen H, Unlucerci Y, Isbir T, Gurdol F.
Department of Biochemistry, Faculty of Medicine, Baskent University, Ankara, Turkey.
Paraoxonase 1 (PON1) is thought to influence serum homocysteine concentrations, at least in part, due to its homocysteine thiolactonase activity and to play a role in preeclampsia and atherosclerosis. We investigated the effects of PON 55 and PON 192 polymorphisms on plasma total homocysteine (tHcy) concentrations in preeclamptic and healthy pregnants among Turkish population (N = 106). PON 55 and 192 genotypes were determined by PCR RFLP techniques. Plasma tHcy concentrations were measured by high-performance liquid chromatography. No differences were observed in the distribution of PON 1 55/192 genotypes and allele frequencies between the preeclamptic and healthy pregnants. tHcy level in the plasma of preeclamptic women was found to be increased in comparison with healthy pregnants (P < 0.01). Preeclamptic women bearing the mutated PON 192 RR and wild-type PON1 55 LL genotypes had higher tHcy levels than those of the healthy pregnants with the corresponding genotypes, supporting the possibility that the hyperhomocysteinaemia seen in preeclamptic women is associated with the PON genotypes. However, no influence of the allelic distribution on plasma tHcy concentrations was detected in either group. Our results suggest that PON1 55 and 192 genotypes might have an important role in developing hyperhomocysteinaemia and may also have a role in the pathogenesis of preeclampsia in a Turkish population.
Yazan: admin Tarih: Tem 12th, 2009 | Kategori::
Kategorilenmemiş
In Vivo. 2009 May-Jun;23(3):421-4.
Arpaci A, Görmüs U, Dalan B, Berkman S, Isbir T.
Department of Molecular Medicine, Istanbul University, Capa, Istanbul, Turkey.
BACKGROUND: Ovarian cancer is the leading cause of death due to gynecological malignancies among women. Oxidative stress is potentially harmful to cells and reactive oxygen species are known to be involved in the initiation and progression of cancer. Paraoxonase (PON1) is an antioxidative enzyme, which eliminates lipid peroxides. PON1 has two common polymorphisms (M/L55 and A/B192) that influence PON1 concentration and activity. PATIENTS AND METHODS: Whether or not the M/L55 or A/B192 genotype relates with ovarian cancer was studied in 51 patients and 54 controls. Polymerase chain reaction (PCR) restriction fragment length polymorphism (RFLP), and agarose gel electrophoresis techniques were used to determine these polymorphisms. RESULTS: The proportion of smokers was significantly higher in the patients than the controls (26.9% vs. 7%; Chi-square: 7.81, p:0.005; Odds ratio (OR): 4.88 95% CI: 1.49-15.99). The frequencies of the PON1 192 AA, BB and AB genotypes among the patients were 0.76, 0.12 and 0.12 and among the control subjects, 0.33, 0.11 and 0.56, respectively. The AA genotype frequency was significantly higher in the patients than the controls (Chi-square: 19.242, p=0.000; OR: 2.80 95% CI:1.653-4.757). The frequencies of the PON1 55 LL, MM and LM genotypes among the patients were 0.53, 0.10 and 0.37 and among the control subjects there were 0.46, 0.04 and 0.50, respectively. The MM genotype frequency was higher in the patients than the controls, but not statistically significantly (p>0.05). CONCLUSION: The two polymorphisms were associated with the age of onset of ovarian cancer, which increased in the genotype order AB<AA<BB in the PON1 192 polymorphism and LM<LL<MM in the PON1 55 polymorphism. The PON1 192 AA genotype may play an important role as a risk factor for ovarian cancer in the Turkish population and the A and L alleles may be associated with early onset of disease.
