Petr Bienert

No association of defined variability in leptin, leptin receptor, adiponectin, proopiomelanocortin and ghrelin gene with food preferences in the Czech population.

Abstract Background: Previously, it has been reported that mutations in the genes encoding for adipokines may be associated with impaired food intake and may serve as potential obesity biomarkers. The aim of this study was to investigate the possible associations of defined variability in leptin, leptin receptor, adiponectin, proopiomelanocortin and ghrelin genes with food preferences in the obese and non-obese Czech population and evaluate their potential as the obesity susceptibility genes. Patients and Methods: Using PCR followed by restriction analysis, we studied 185 volunteers. Basic anthropometrical characteristics associated to obesity were measured and the food intake was monitored using a 7-day record method. In the group of obese individuals, a subset of 34 morbidly obese patients was studied for plasma leptin and soluble leptin receptor levels. Results: None of the examined polymorphisms was associated to anthropometrical or demographic characteristics of the study subjects. The Gln223Arg polymorphism within the leptin receptor gene was significantly associated with lower plasma leptin levels (the RR genotype being more frequent in patients with lower plasma leptin levels; P = 0.001). No associations of the examined polymorphisms with food preferences was observed. Conclusions: Based on our results, the examined polymorphisms in the adipokine genes do not seem to be the major risk factor for obesity development in the Czech population nor significantly affect food preferences.

Association between variants in the genes for leptin, leptin receptor, and proopiomelanocortin with chronic heart failure in the Czech population

Patients with chronic heart failure (CHF) express enhanced catabolic metabolism finally resulting in overall weight loss, whereas adipokines might play a crucial role in signaling among tissues. The aim of this study was to investigate the possible associations of defined variability in leptin (dbSNP ID rs7799039), proopiomelanocortin (dbSNP ID rs3754860 and dbSNP ID rs1009388), and leptin receptor gene (dbSNP rs1137101) with CHF and evaluate their potential as the CHF susceptibility genes. The case-control study comprised a total of 372 patients of Caucasian origin with chronic heart failure (New York Heart Association [NYHA] functional classes II–IV, ejection fraction (EF) <40%) and 407 healthy controls. They were genotyped for the leptin (LEP) −2548 G/A, leptin receptor (LEPR) Gln223Arg, and proopiomelanocortin (POMC) RsaI (5′-untranslated region) and C1032G variants (intron 1) using PCR-based methodology. No case-control differences in genotype as well as allele frequencies were observed between CHF patients and controls. We constructed POMC RsaI/C1032G haplotypes, having found no significant association with body mass index (BMI), left ventricle ejection fraction (LVEF), left ventricle hypertrophy (LVH) and diabetes mellitus (DM). Multivariate regression analyses revealed an approximately 2-fold risk for NYHA class IV associated with the LEPR Gln223Arg (P = 0.0000001, odds ratio [OR] = 2.10, 95% confidence interval [CI] = 1.56−2.84); it also displayed an independent prediction role for LVEF in heart failure cases of all etiologies (P = 0.002, OR = 4.05, 95% CI = 1.36−10.06). In subanalyses according to CHF etiology the LEPR Gln223Arg showed an independent prediction role for NYHA IV in IHD patients (P = 0.0001, OR = 2.50, 95% CI = 1.69−3.82) and both for NYHA IV(P = 0.007, OR = 2.04, 95% CI = 1.20−3.84) and LVEF (P = 0.004, OR = 11.87, 95% CI = 2.08−55.6) in DCMP patients. The role of the polymorphic variants in the genes encoding for adipokines as potential CHF susceptibility genes is unclear. Based on our findings, the LEPR Gln223Arg polymorphism could be considered a disease susceptibility modulating factor both in ischemic heart disease or dilated cardiomyopathy patients.

ASSOCIATION OF LEPTIN GENETIC POLYMORPHISM -2548 G/A WITH GESTATIONAL DIABETES MELLITUS

The aim of this study was to investigate possible associations of -2548 G/A polymorphism in leptin gene promoter and pregnancy-associated diseases with abnormal fetal growth such as preeclampsia and gestational diabetes. The study was also focused on whether it is rather maternal or fetal variants that determines the pathological growth status. Peripheral or cord blood samples obtained from 49 preeclamptic women and their 39 newborns, 53 healthy controls and their 53 healthy newborns and 48 patients with gestational diabetes mellitus were evaluated for leptin gene (LEP) locus -2548 genotypes. The significantly higher risk for gestational diabetes mellitus was observed in the presence of an allele (AA and AG genotypes) against carriers of GGgenotype(OR=2.84, 95%CI1.14–7.07,p=0.02). Thereisa significant risk of diabetes mellitus associated to A allele (OR=1.79, 95%CI 1.02–3.14, p=0.03). Furthermore, evaluations of preeclamptic patients’ data revealed a significant association of genotype distribution and delivery and spontaneous abortion rate, where the GG carriers performed the highest pregnancy rate while the AG carriers performed the lowest spontaneous abortion rate. Our results support the hypothesis for -2548 G/A leptin gene polymorphism involvement in ethiopathogenesis of pregnancy-associated diseases with abnormal fetal growth, especially gestational diabetes mellitus.

Genotype x nutrient association of common polymorphisms in obesity-related genes with food preferences and time structure of energy intake.

Personal food preferences can either enhance or suppress the development of obesity and the selection and proportion of macronutrients in the diet seem to have a heritable component. In the present study, we therefore focused on dietary composition as a specific trait related to obesity and we determined whether genetic variations in leptin (LEP), LEP receptor (LEPR), adiponectin (ADIPOQ), IL-6 and pro-opiomelanocortin (POMC) underlie specific native food preferences and obesity-related anthropometric parameters. The total of 409 individuals of Czech Caucasian origin were enrolled into the present study and 7 d food records were obtained from the study subjects along with selected anthropometric measurements. In a subset of study subjects, plasma levels of ADIPOQ, LEP and soluble LEPR were measured. Independently of the BMI of the individuals, common variations in LEP and LEPR genes were associated with specific eating patterns, mainly with respect to timing of eating. The LEP + 19A/G polymorphism served as an independent predictor for BMI, percentage of body fat and skinfold thickness and significantly affected the time structure of the daily energy intake. The POMC RsaI polymorphism was associated with percentage of body fat. The ADIPOQ 45 T/G polymorphism was associated with the thickness of the subscapular skinfold. The LEPR Gln223Arg polymorphism was associated with multiple parameters, including diastolic blood pressure, meal sizes during the day and plasma ADIPOQ levels. In a separate analysis, soluble leptin receptor (sObR) plasma levels and LEP:sObR ratio were significantly correlated with systolic blood pressure (beta = - 0.66, P = 0.002; beta = - 1.23, P = 0.02) and sObR plasma levels also served as an independent predictor for diastolic blood pressure (beta = - 0.50; P = 0.04). To conclude, we report common allelic variants associated with specific feeding behaviour and obesity-related anthropometric traits. Moreover, we identified allelic variants that significantly influence the time structure of food intake during the day.

Is there any link between severe pre‐eclampsia and defined polymorphisms in leptin and adiponectin genes?

Aim:  The pathophysiology of pre‐eclampsia, one of the leading causes of maternal mortality worldwide, still remains unclear. Recently, it has been suggested that impaired regulation of complex interactions among various adipokines plays an important role in the development of pre‐eclampsia. The aim of this study was to investigate whether the two common polymorphisms of the leptin (LEP) and adiponectin (APM1) genes are associated with the development of pre‐eclampsia and its related traits (gestational hypertension, proteinuria and various measures of reduced fetal growth ) in the Czech pre‐eclamptic population.

Visfatin is secreted into the breast milk and is correlated with weight changes of the infant after the birth

INTRODUCTION Visfatin is a recently identified adipokine with numerous metabolic and immunoregulatory properties that has been implicated in the regulation of the white adipose tissue (WAT) and significant changes in visfatin levels were reported during pregnancy. The aim of the study was to investigate dynamics of visfatin levels in maternal serum and human breast milk during a 180-d period after the delivery. MATERIALS AND METHODS : Breast milk and venous blood samples were obtained from 24 healthy lactating women with uncomplicated, physiological pregnancy and appropriate-for-gestational age neonates and serum-milk sample duos were collected at the time of birth, at the 1-3, 12-14, 28-30, 88-90 and 178-180 postpartum. RESULTS Our study demonstrates that (1) visfatin is abundantly secreted into breast milk in humans, reaching approx. 100× higher concentrations compared to maternal serum; (2) visfatin concentrations in maternal serum show significant variations after the delivery and (3) visfatin concentration in colostrum could be used for prediction of the subsequent weight development (less/more severe weight loss during first 3 days after the birth) of the infant. DISCUSSION Our data suggest that visfatin could play an important role in regulation of adiposity of the infant after the birth.

Brain-derived neurotrophic factor and ciliary neurotrophic factor in maternal plasma and umbilical cord blood from pre-eclamptic and physiological pregnancies

The aim of the study was to investigate the circulating levels of ciliary neurotrophic factor (CNTF) and brain-derived neurotrophic factor (BDNF) in maternal serum and umbilical cord blood from respective pregnancies in pre-eclampsia (PE) cases and a control cohort. A total of 12 pre-eclampsia cases and 34 healthy controls were enrolled and the maternal peripheral blood – umbilical cord blood duos, were examined for BDNF and CNTF levels. BNDF levels were significantly higher in umbilical cord blood from pre-eclamptic pregnancies; there was also significant difference between maternal plasma and umbilical cord blood levels of BDNF (p < 0.001) in the controls. The CNTF levels in umbilical cord blood (CNTF-UCB) were significantly higher in PE cases than in the controls (p = 0.03). Significant differences were observed in expression of BDNF and CNTF proteins in maternal peripheral blood and umbilical cord blood between pre-eclampsia cases and healthy controls.

B-cell activating factor (BAFF) – a new factor linking immunity to diet?

B cell activation factor (BAFF) is a recently discovered member of the TNF ligand superfamily secreted by adipocytes, previously linked to autoimmune and lymphoproliferative disease. The aim of this study was to investigate the relationship between BAFF plasma levels and the non-modified, usual dietary composition as well as obesity-related anthropometric parameters in a cohort of 58 obese and non-obese Central-European Caucasian individuals. We found that BAFF had an independent predictive role for percentage of body fat; moreover, BAFF levels were correlated with waist and hip circumference. BAFF plasma levels were also significantly correlated with investigated dietary composition based on the 7-day food records, as the BAFF levels correlated with the percentage of energy derived from the carbohydrates and with energy derived from the dietary fat. Our results suggest that BAFF may play a role in linking the immune status and metabolic response to diet.

A common variation in the cannabinoid 1 receptor (CNR1) gene is associated with pre-eclampsia in the Central European population.

OBJECTIVE Recently it has been proposed that tightly regulated levels of endogenous cannabinoids play a fundamental role in early placental development. The aim of this study was to investigate associations of three single-nucleotide polymorphisms (SNPs) in the cannabinoid 1 receptor (CNR1) gene (rs1049353, rs12720071 and rs806368) and their inferred haplotypes with pre-eclampsia, a severe pregnancy-associated condition characterized by abnormal development and remodeling of spiral decidual arteries. STUDY DESIGN The case-control study comprised a total of 115 pre-eclamptic women and 145 healthy pregnant controls, all originating from the Central-European Czech population. Using PCR-based methods, we tested rs1049353, rs12720071 and rs806368 in the CNR1 gene and haplotypes were constructed. RESULTS Statistically significant difference in genotype distributions of rs806368 (p(g)<10(-3)) was observed when comparing the cases and the controls; the cases presenting with significantly lower proportion of CC homozygotes. In multivariate modeling, the rs806368 served as a predictor for pre-eclampsia development (β=0.15; p=0.04). Haplotype analysis revealed presence of four common haplotypes; the CAA haplotype being less frequent in pre-eclamptic cases compared to the controls (p<0.008). Analysis of regression models confirmed the independent prediction role of AAC haplotype for pre-eclampsia onset (β=-0.18; p=0.03). CONCLUSION This is the first study focusing on the relationship between SNPs in the CNR1 gene and pre-eclampsia risk. Although limited by a relatively small sample size, the study indicates that rs806368 in the CNR1 gene may act as a susceptibility marker for pre-eclampsia in humans.

Variability in CNR1 locus influences protein intake and smoking status in the Central-European population

Abstract Objectives The endocannabinoid receptor 1 (CB1) is encoded by the CNR1 gene and has been recently recognized to play an important role in the regulation of satiety and feeding behaviour with a huge potential of modulating metabolic response and feeding control. The aim of the study was to investigate the potential of three selected single nucleotide polymorphisms (SNPs) in the CNR1 locus on native dietary composition in the Central-European Caucasian population. Methods A total of 258 unrelated individuals originating from the Central-European Caucasian population were enrolled into the study and rs1049353, rs12720071, and rs806368 polymorphisms in CNR1 locus were examined in these individuals using PCR-based methodology. Body composition was assessed using a bioimpedance method, various anthropometric parameters were investigated (waist and hip circumference, skin folds), and native dietary composition was analysed using 7-day food records as well as a food frequency questionnaire. Results Allelic variations and common haplotypes in the CNR1 gene were associated with the daily intake of proteins, fluids, and fibre, regardless of the physical activity of the individuals. The common haplotype in the CNR1 gene was associated with self-reported smoking (number of cigarettes per day, smoking years). Discussion Our results indicate that specific genetic variations in the CNR1 gene may act as susceptibility markers for specific dietary composition in the Central-European population.