Association and interaction of PPARα, δ, and γ gene polymorphisms with low-density lipoprotein-cholesterol in a Chinese Han population.

AIMS: Elevated low-density lipoprotein-cholesterol (LDL-C) is regarded as one of major risks of cardiovascular diseases and atherosclerotic events. It has been previously reported that peroxisome proliferator-activated receptors (PPARs) play an important role in the regulation of lipid metabolism. In this study, we aimed to investigate the influence of PPARα/δ/γ gene polymorphisms on LDL-C level. Eight hundred twenty unrelated participants were recruited. Ten single-nucleotide polymorphisms (SNPs) were genotyped to analyze the gene-gene interactions among these polymorphisms using the generalized multifactor dimensionality reduction (GMDR) method. RESULTS: The results of single-locus analyses indicated that the genotypes with minor allele variants at the rs1800206, rs9794, rs1805192, rs709158, and rs3856806 loci are associated with higher LDL-C levels (p<0.05) after adjusting for covariates. In contrast, individuals that were homozygous for the major allele (CC) of rs10865710 had significantly higher LDL-C than those with either one or more minor type alleles (CG+GG, mean difference: -0.21 mM; 95% confidence interval [CI]: -0.37 to -0.04 mM; p=0.013). Significant gene-gene interactions among PPAR gene polymorphisms on LDL-C were identified by a generalized multifactor dimensionality reduction (GMDR) approach in 2- to 8-locus models (p<0.05). CONCLUSION: Our results provide evidence that multiple PPARα/δ/γ gene polymorphisms are individually associated with increased LDL-C, and that interactions, among these alleles result in additional increased risk suggesting that PPAR genes may contribute substantially to the risk of cardiovascular diseases and atherosclerosis.

Changes in plasma PPARs levels in migraine patients.

BACKGROUND: The aim of this study was to observe the change in plasma PPARs (peroxisome proliferator-activated receptors) level during various periods and in different subtypes in migraine patients. MATERIAL AND METHODS: We divided 227 patients with migraine into 2 main groups: the attack period group (n=98) and the attack-free period group (n=129). Patients were further divided into 4 subgroups according to whether they had aura symptoms. The control group consisted of 100 healthy subjects. We collected the clinical data of patients and measured the plasma levels of PPARs using enzyme-linked immunoassay (ELISA). We used SPSS software for statistical analysis. RESULTS: We found no significant difference in age, BMI, blood pressure, or blood lipid level among migraine patients during the headache attack period and during the headache-free period compared with the control group. The PPARα and PPARß/δ levels during the headache attack period were significantly higher than during the headache free period and in healthy controls. The PPARγ levels during the headache attack period were significantly lower than those during the headache-free period and in the healthy control group. The PPARs levels during the headache attack period were significantly different from those during the headache-free period, regardless of presence or absence of aura. The PPARs levels during the headache-free period were not significantly different from those of the healthy control group. The level of PPARs has no significant differences between migraine with aura group and without aura group, regardless of whether headache attack. CONCLUSIONS: PPARs involved in the pathogenesis of migraine. Presence of absence of aura had no obvious effect on PPARs level.

Circadian clock gene expression is impaired in gestational diabetes mellitus.

Dysfunction of the circadian clock genes is involved in the development of obesity and type 2 diabetes (T2D). Since gestational diabetes mellitus (GDM) and T2D share common genetic and phenotypic features, in the present study, we investigated the status of the circadian clock in a cohort of 40 Greek pregnant women with GDM, four with T2D and 20 normal controls. Peripheral blood mRNA transcript levels of 10 clock genes (CLOCK1, BMAL1, PER1, PER2, PER3, PPARΑ, PPARD, PPARG, CRY1 and CRY2) were determined by real-time quantitative PCR. GDM patients expressed significantly lower transcript levels of BMAL1, PER3, PPARD and CRY2 compared to control women (p < 0.05). No significant difference was documented between GDM women maintained either under insulin treatment or diet. A positive correlation was found between the expression of BMAL1 versus CRY2 (r = 0.45, p = 0.003) and BMAL1 versus PPARD (r = 0.43, p = 0.004). Further investigation on the functional relevance of these clock genes, disclosed that expression of PER3 correlated negatively with HbA1C levels (r = -0.36, p = 0.022). These data document for the first time that the expression of BMAL1, PER3, PPARD and CRY2 genes is altered in GDM compared to normal pregnant women and support the notion that deranged expression of clock genes may play a pathogenic role in GDM.

Polimorfismo Pro12Ala del gen PPAR-γ 2 y síndrome metabólico: Estudio preliminar / Pro12Ala polymorphism of the PPAR-gamma2 gene and the metabolic syndrome: Preliminary study

El objetivo de este estudio fue determinar la prevalencia del polimorfismo Pro12Ala del gen PPARgamma2 en individuos no emparentados con síndrome metabólico de la ciudad de Maracaibo. Se seleccionaron 50 individuos (22 con síndrome metabólico y 28 sin síndrome metabólico) entre 22 y 58 años. A cada individuo se le realizó una evaluación clínica, nutricional y bioquímica. Para analizar la secuencia de la variante Pro12Ala del gen PPAR se empleó PCR y digestión enzimática de los fragmentos de restricción del polimorfismo (PCR-RFLP). En los individuos con síndrome metabólico el porcentaje de portadores del alelo Ala fue de 13,6%, mientras que en el grupo sin síndrome metabólico fue de 32,14%. La frecuencia para el alelo Ala del polimorfismo Pro12Ala fue de 0,12 y para el alelo Pro fue de 0,88. Los individuos con síndrome metabólico y portadores del alelo Ala presentaron niveles más bajos de triglicéridos y col-HDL más alto. Se concluye que la presencia del alelo Ala en individuos con síndrome metabólico mostró un efecto protector sobre el perfil lipídico.

The aim of this paper was to determine the prevalence of the polymorphism pro12ala in non-related individuals with metabolic syndrome from Maracaibo-Venezuela. Fifty subjects (22 with metabolic syndrome and 28 without metabolic syndrome) between 22 to 58 years of age were selected. For each individual, biochemical, nutritious, and clinical evaluations were carried out. PCR and restriction-fragment length polymorphism enzyme digestion were used to analyze the Pro12Ala sequence variant of the PPAR gene. The distribution of the Ala allele was 13.6% in the individuals with metabolic syndro- and 32.14% in the group without metabolic syndrome. The frequency distributions of the PPAR gamma sequence variants were 0.12 for Ala variant and 0.88 for Pro. The subjects with the metabolic syndrome and carriers of the Ala 12 allele had lower concentration of triglycerides and higher HDL-C. It can be concluded that the Ala12 allele in individuals with metabolic syndrome had a protective effect on the lipid profile.

Selective PPAR modulators, dual and pan PPAR agonists: multimodal drugs for the treatment of type 2 diabetes and atherosclerosis.

More than 70% of patients with Type 2 diabetes mellitus (T2DM) die because of cardiovascular diseases. Current therapeutic strategies are based on separate treatment of insulin resistance and dyslipidaemia. Development of drugs with multimodal activities should improve management of the global cardiovascular risk of T2DM patients and result in better patient compliance. New therapeutic strategies are aimed at targeting the entire spectrum of dysfunctioning organs, cells and regulatory pathways implicated in the pathogenesis of T2DM, dyslipidaemia and atherosclerosis. PPAR family members play major roles in the regulation of lipid metabolism, glucose homeostasis and inflammatory processes, making these transcription factors ideal targets for therapeutic strategies against these diseases. This review discusses why PPARs and development of novel selective PPAR modulators, dual and pan PPAR agonists constitute promising approaches for the treatment of diabetes, dyslipidaemia and atherosclerosis.

[Clinical genetic determinants of carbohydrate metabolism disturbances in patients with hypertension and excessive weight].

AIM: To elucidate associations of polymorphic markers of PPAR, PPARG2, IRS1, IRS2 genes with disturbances of carbohydrate metabolism in patients with hypertension and excessive weight. MATERIAL: Patients (n=145, 53 men and 92 women, age 40-75 years) with untreated stage 1 hypertension (systolic BP 140-159 and diastolic BP <100 mm Hg) and excessive weight or obesity (body mass index >27 kg/m(2)) were divided into 2 groups: with (group 1, n=124) and without (group II, n=21) disturbances of carbohydrate metabolism. Group I comprised patients with insulin resistance, abnormal fasting blood glucose or glucose tolerance, type 2 diabetes. Results of oral glucose tolerance test were normal in 25 and abnormal in 99 of these patients. RESULTS: Carriers of Pro allele compared with carriers of Ala allele of PPARG2 gene had higher frequency of insulin resistance. No association was found between insulin resistance and alleles and genotypes of PPAR, IRS1, and IRS2 genes. There was an association between diastolic BP and polymorphic markers Pro12Ala of PPARG2 gene and C24313G of PPARA gene. Carriers of C allele of PPARA gene and Ala allele of PPARG2 gene had higher diastolic BP. No association was found between systolic BP and alleles and genotypes of polymorphic markers of PPARG2 and PPARA genes.

Peroxisome proliferator-activated receptor agonists modulate heart function in transgenic mice with lipotoxic cardiomyopathy.

hLpL(GPI) transgenic mice that overexpress human lipoprotein lipase (hLpL) with a glycosylphosphatidylinositol anchor on cardiomyocytes develop lipotoxic cardiomyopathy associated with increased cardiac uptake of plasma lipids. We hypothesized that peroxisome proliferator-activated receptor (PPAR)alpha, PPARgamma, or a PPARalpha/gamma agonist would alter cardiac function by modulating lipid uptake by the heart. hLpL(GPI) mice were administered rosiglitazone (10 mg/kg/day), fenofibrate (100 mg/kg/day), or DRF2655, an alkoxy propanoic acid analog (10 mg/kg/day), for 16 days. Rosiglitazone reduced plasma triglyceride (TG) from 107.63 +/- 6.98 to 77.61 +/- 3.98 mg/dl, whereas fenofibrate had no effect. DRF2655 reduced TG to 33.17 +/- 4.12 mg/dl. Rosiglitazone and DRF2655 decreased heart TG and total cholesterol; fenofibrate had no effect. Molecular markers for cardiac dysfunction, atrial natriuretic factor, brain natriuretic peptide, and tumor necrosis factor-alpha were decreased with rosiglitazone and increased with fenofibrate. Echocardiographic measurements showed reduced fractional shortening and increased left ventricular systolic dimension with fenofibrate. No changes in these parameters were observed with rosiglitazone or DRF2655 treatment. Muscle-specific carnitine palmitoyltransferase-1 and fatty acid transporter protein-1 gene expression were increased with fenofibrate and DRF2655 treatment; no change in expression of these genes was noted with rosiglitazone treatment. Rosiglitazone and DRF2655 reduced TG uptake by the heart, and fenofibrate treatment increased fatty acid uptake. Thus, in a lipotoxic cardiomyopathy mouse model, a PPARgamma agonist reduced cardiac lipid and markers of cardiomyopathy, whereas an agonist of PPARalpha did not improve cardiac lipids and worsened heart function. These changes were paralleled by alterations in heart lipid uptake. Overall, PPAR activators exhibit differential effects in this model of lipotoxic dilated cardiomyopathy.