Plasminogen activator inhibitor-1 (PAI-1) gene polymorphism (-675 4G/5G) associated with obesity and vascular risk in children

Genetic factors associated with obesity risks in a Kazakhstani population

Objectives

There is limited published literature on the genetic risks of chronic inflammatory related disease (eg, obesity and cardiovascular disease) among the Central Asia population. The aim is to determine potential genetic loci as risk factors for obesity for the Kazakhstani population.

Setting

Kazakhstan.

Participants

One hundred and sixty-three Kazakhstani nationals (ethnic groups: both Russians and Kazakhs) were recruited for the cross-sectional study. Linear regression models, adjusted for confounding factors, were used to examine the genetic associations of single nucleotide polymorphisms (SNPs) in 19 genetic loci with obesity (73 obese/overweight individuals and 90 controls).

Results

Overall, logistic regression analyses revealed genotypes C/T in CRP (rs1205), A/C in AGTR1 (rs5186), A/G in CBS (rs234706), G/G in FUT2 (rs602662), A/G in PAI-1 (rs1799889), G/T (rs1801131) and A/G (rs1801133) in MTHFR genes significantly decrease risk of overweight/obesity. After stratification for ethnicity, rs234706 was significantly associated with overweight/obesity in both Russians and Kazakhs, while rs1800871 was significant in Kazakhs only.

Conclusions

This study revealed that variations in SNPs known to be associated with cardiovascular health can also contribute to the risks of developing obesity in the population of Kazakhstan.

The contribution of different adipose tissue depots to plasma plasminogen activator inhibitor-1 (PAI-1) levels

Increased plasma plasminogen activator inhibitor-1 (PAI-1) level is considered a mechanistic pathway through which obesity contributes to increased cardiovascular disease risk. Abdominal adipose tissue specifically, is a major PAI-1 source with visceral adipose tissue (VAT), an ectopic fat depot, generally considered to produce more PAI-1 than subcutaneous adipose tissue. However, this does not necessarily lead to increased plasma PAI-1 levels. This review provides an overview of studies investigating the association between body fat distribution and plasma PAI-1 levels. It discusses factors that influence this relationship and also considers the contribution of other tissue to plasma PAI-1 levels, placing the relative contribution of adipose tissue into perspective. In conclusion, the relationship between VAT and plasma PAI-1 levels is not fixed but can be modulated by a number of factors such as the size of the subcutaneous adipose tissue depot, ethnicity, possibly genetics and other obesity-related metabolic abnormalities.

Quadruple Vessel Coronary Artery Bypass Grafting in a 14-Year-Old Child With Plasminogen Activator Inhibitor-1 4G/4G Gene Polymorphism

Myocardial ischemia due to coronary artery disease is an extremely rare condition in childhood and adolescence. Absence of obvious serious risk factors remains a challenge to modern cardiology. We present the case of a 14-year-old boy who underwent quadruple-vessel coronary artery bypass grafting with bilateral pedicled internal mammary artery and bilateral radial artery grafting. We try to highlight a rare but important 4G variant PAI-1 (SERPINE 1) gene mutation as the etiology of severe coronary artery disease in our patient. To the best of our knowledge, he is one of the youngest patients who underwent coronary artery bypass surgery with 4 arterial grafts.

Haemostatic risk factors in dyslipidemic rabbits: role of 10-dehydrogingerdione as a new hypolipemic agent

Micro and macrovascular complications occurring during hyperlipidemia are mostly attributed to haemostatic impairment and vascular endothelial dysfunction. Cholesteryl ester transfer protein (CETP) inhibitors have been emerged recently as promising hypocholesterolemic agents to confer protection against lipid-mediated atherosclerosis. Therefore, 10-dehydrogingerdione (DHGD), a novel CETP inhibitor isolated from ginger rhizomes, was selected as a natural product in the present study to illustrate its effect on haemostatic impairment associated with hyperlipidemia as compared to a currently used hypocholesterolemic agent, atorvastatin (ATOR). Rabbits were fed a high cholesterol diet (HCD) and divided into three groups. One group served as control group while the other groups received DHGD or ATOR. Dyslipidemic rabbits showed a significant increase in serum endothelin-1, ischemia modified albumin, plasminogen activator inhibitor-1, prothrombin fragments (1+2) and plasma fibrinogen along with a decrease of nitric oxide level in serum. Daily administration of ATOR or DHGD significantly decreased the aforementioned coagulation and ischemia biomarkers and increased serum nitric oxide. DHGD (natural) results seem to be more remarkable as compared to ATOR (synthetic).

Association between the rs6950982 polymorphism near the SERPINE1 gene and blood pressure and lipid parameters in a high-cardiovascular-risk population: interaction with Mediterranean diet

The SERPINE1 (serpin peptidase inhibitor, clade E, member 1) gene, better known by its previous symbol PAI-1 (plasminogen activator inhibitor 1), has been associated with cardiovascular phenotypes with differing results. Our aim was to examine the association between the rs6950982 (G > A) near the SERPINE1 gene, blood pressure (BP) and plasma lipid concentrations as well as the modulation of the polymorphism effects by adherence to Mediterranean diet (AMD). We studied 945 high-cardiovascular-risk subjects. Biochemical, clinical, dietary and genetic data (rs6950982) were obtained. We also determined the common rs1799768 (4G/5G), for checking independent effects. AMD was measured by a validated questionnaire, and four groups were considered. rs6950982 (A > G) and rs1799768 (4G/5G) were only in moderate-low linkage disequilibrium (D' = 0.719; r (2) = 0.167). The most significant associations we obtained were with rs6950982 (A > G). In males, the G allele was nominally associated with higher diastolic BP (AA: 81.5 ± 10.9, AG: 82.1 ± 11.4, GG: 85.7 ± 10.5 mmHg; P additive = 0.030) and systolic BP (AA + AG: 141.4 ± 6.9 mmHg vs. GG: 149.8 ± 8.0 mmHg; P recessive = 0.036). In the whole population, the rs6950982 was also associated with plasma lipids. Subject with the G allele presented higher total cholesterol (P additive = 0.016, P recessive = 0.011), low-density lipoprotein cholesterol (P additive = 0.032, P recessive = 0.031) and triglycerides (P additive = 0.040, P recessive = 0.029). AMD modulated the effect of rs6950982 on triglyceride concentrations (P for interaction = 0.036). Greater AMD reduced the higher triglyceride concentrations in GG subjects. No significant interactions were found for the other parameters. The rs6950982 was associated with higher BP in men and higher triglycerides in the whole population, this association being modulated by AMD.

Impaired fibrinolytic system in ApoE gene-deleted mice with hyperlipidemia augments deep vein thrombosis

BACKGROUND

Hyperlipidemia increases the level of blood plasminogen activator inhibitor-1 (PAI-1) that is responsible for regulating fibrinolysis by inhibiting both urokinase-type plasminogen activator (u-PA) and tissue-type plasminogen activator (t-PA). While this fibrinolytic pathway is well known, the role of PAI-1 in venous thrombosis (VT) under hyperlipidemic conditions has not been fully established. We sought to determine the effects of PAI-1 in an in vivo hyperlipidemic model of VT.

METHODS

C57BL/6 wild-type (WT) mice, apolipoprotein E gene-deleted mice (ApoE-/-) having hyperlipidemia, and PAI-1 gene-deleted (PAI-1-/-) mice were used in this study. Inferior vena cava (IVC) ligation below the level of the renal veins was performed to create a stasis VT. Endpoints included measuring acute thrombosis (day 2) and chronic thrombosis (days 6 and 14). At euthanasia, blood samples were collected for plasmin and PAI-1 activity. In addition, the IVC and its thrombus were evaluated for thrombus weight (TW), u-PA activity, and differential leukocyte count while the vein wall only was analyzed for monocyte chemoattractant protein-1 (MCP-1), matrix metalloproteinase (MMP) 2, and MMP-9.

RESULTS

Compared to WT at day 2, ApoE-/-mice demonstrated a statistically significant 14% increase in TW (P < .05) and a significant 41% increase in circulating PAI-1 activity (P < .05), while showing a trend of decreased plasmin activity. In addition, TW in ApoE-/-mice was 45% higher than PAI-1-/-mice at day 2 (P < .05), 33% at day 6 (P < .01), and 41% at day 14 (P < .01). ApoE-/-mice exhibited undetectable levels of u-PA in both vein wall and thrombus, compared to WT, at all time points. Also, vein wall MMP-2 was significantly decreased by 64% at day 6 (P < .01) and 58% at day 14 (P < .05). MMP-9 was significantly decreased by 71% at day 2 (P < .01) and 48% at day 6 (P < .01), in ApoE-/-mice compared to WT mice. In addition, in ApoE-/-mice, MCP-1 was significantly decreased by 38% at day 2 (P < .01) and 67% at day 6 (P < .01) vs WT mice. As expected in ApoE mice, following a decrease in MCP-1, monocyte recruitment was significantly decreased at days 6 (P < .01) and 14 (P < .05).

CONCLUSIONS

A significant increase of circulating PAI-1 levels in hyperlipidemic mice correlated with an early increase in TW due to impaired fibrinolysis. The undetectable levels of u-PA in ApoE-/-mice correlated to a decrease in vein wall MMP-2, MMP-9, MCP-1, and a decrease in monocyte recruitment diminishing thrombus resolution.

Evaluation of hypercoagulability in obese children with thrombin generation test and microparticle release: effect of metabolic parameters

Obesity is associated with a hypercoagulable state. Thrombin generation test (TGT) and microparticle levels were not studied in obese children extensively. It is aimed to determine whether any differences in the coagulation system between obese and normal weighed children exist with the use of TGT and microparticles release. A total of 120 obese and 38 healthy children were included to the study. An increase of thrombin generation and microparticles levels were found in obese children. Hyperinsulinism could not find a risk factor for hypercoagulability in our obese children. None of the parameters of TGT has been shown to be related to metabolic parameters and metabolic syndrome. Microparticles release time is found to correlate only to body mass index (BMI) Standard deviation score (SDS) in obese children. Hypercoagulability is associated with childhood obesity. Significant correlation between degree of obesity and microparticles release suggested that high adipokine levels secreted from adipose tissue can stimulate procoagulant status-independent metabolic dearrangements.

Childhood obesity: evidence of an association between plasminogen activator inhibitor-1 levels and visceral adiposity

BACKGROUND

Plasminogen activator inhibitor-1 (PAI-1) has been considered as a cardiovascular risk factor, mainly because of its strong association with insulin resistance.

METHODS

To detect independent predictors of circulating PAI-1 levels in obese pediatric patients, we evaluated 86 subjects (mean age 10.7 +/- 2.8 years), 42 of whom were male (49%). Subjects were divided in two groups according to body mass index (BMI): obese subjects (n=61) and healthy non-obese controls (n=25). They were also divided by pubertal status. Besides anthropometric data, levels of PAI-1, leptin and biochemical markers of metabolic syndrome were measured.

RESULTS

The obese group had higher levels of PAI-1, leptin and biochemical markers of metabolic syndrome than nonobese controls (p<0.05). However, multivariate regression analysis showed that only puberty progression (p=0.005) and abdominal circumference/height index (p=0.002) remained independent predictors of PAI-1 levels.

CONCLUSION

In pediatric obesity, fat mass accumulation, mainly of visceral fat, and puberty progression were related to high PAI-1 levels, which might in turn contribute to cardiovascular risk.

Contribution of clinical, metabolic, and genetic factors on hypertension in obese children and adolescents

The role of ACE gene insertion (I) or deletion (D) polymorphism on blood pressure phenotype is not clear in children. The aim of this work is to examine the association between hypertension and ACE I/D polymorphism, as well as the contribution of clinical and metabolic parameters on blood pressure. The study participants were 199 obese children. Forty-four of them were hypertensive. The hypertensive subjects were older than the normotensive and most of them were pubertal. The prevalence of hypertension in obese subjects with II, ID, and DD genotype was similar. There was no difference between the hypertensive and the normotensive group according to ACE I/D genotype, BMISDS, sex, blood glucose level and total cholesterol levels. In obese children, high IR-HOMA values, puberty, presence of family history for hypertension, hypertriglyceridemia, and low HDL-cholesterol, high triglyceride/HDL-cholesterol ratio were found as increased risk factors of hypertension. In obese children and adolescents, blood pressure did not differ by ACE I/D genotype. The presence of family history, puberty, insulin resistance and hypertriglyceridemia constitute important risk factors for developing hypertension.

Melanocortin-4 Receptor Polymorphisms in Turkish Pediatric Obese Patients

The most common Melanocortin-4 receptor (MC4R) missense variant Val103Ileu (rs2229616) is related to obesity. In this study, we examined the distribution of MC4R polymorphisms both in the clinical pediatric obese group and in the high/lowsocioeconomic school group. 24 probable exogene obese children without family history (group I), 66 probable familial obese children (group II), and 111 complicated obese children (group III) were included. Groups I and II obese participants were gathered in a school-based epidemiologic study and compared with 49 apparently healthy non-obese controls. Significant difference in genotype distribution was observed between the groups I and II. Val 103 Ile polymorphism was more common among group III (4.5%). Furthermore, we detected Glu 42 Lys (18.18%) polymorphism in our population, which was not previously reported. Frequency of Val 103 Ile (A) allele polymorphism was 0.75 and 2.25; Glu 42 Lys A allele polymorphism was 9.0 and 1.5, in groups II and III, respectively. None of the MC4R mutations were found in high-socioeconomic school and in control groups. Our data indicated that MC4R polymorphisms were more frequent both in clinical pediatric obese group and in low-socioeconomic school group. In addition, our data revealed that carrying the polymorphism may increase the hereditary form of obesity.

Association analysis of ADPRT1, AKR1B1, RAGE, GFPT2 and PAI-1 gene polymorphisms with chronic renal insufficiency among Asian Indians with type-2 diabetes

BACKGROUND

To determine association of nine single nucleotide polymorphisms (SNPs) in ADP ribosyltransferase-1 (ADPRT1), aldo-keto reductase family 1 member B1 (AKR1B1), receptor for advanced glycation end-products (RAGE), glutamine:fructose-6-phosphate amidotransferase-2 (GFPT2), and plasminogen activator inhibitor-1 (PAI-1) genes with chronic renal insufficiency (CRI) among Asian Indians with type 2 diabetes; and to identify epistatic interactionss between genes from the present study and those from renin-angiotensin-aldosterone system (RAAS), and chemokine-cytokine, dopaminergic and oxidative stress pathways (previously investigated using the same sample set).

METHODS

Type 2 diabetes subjects with CRI (serum creatinine > or =3.0 mg/dl) constituted the cases (n = 196), and ethnicity and age matched individuals with diabetes for a duration of > or = 10 years, normal renal functions and normoalbuminuria recruited as controls (n = 225). Allelic and genotypic constitution of 10 polymorphisms (SNPs) from five genes namely--ADPRT1, AKR1B1, RAGE, GFPT2 and PAI-1 with diabetic CRI was investigated. The genetic associations were evaluated by computation of odds ratio and 95% confidence interval. Multiple logistic regression analysis was carried out to correlate various clinical parameters with genotypes, and to study epistatic interactions between SNPs in different genes.

RESULTS

Single nucleotide polymorphisms -429 T>C in RAGE and rs7725 C>T SNP in 3' UTR in GFPT2 gene showed a trend towards association with diabetic CRI. Investigation using miRBase statistical tool revealed that rs7725 in GFPT2 was a perfect target for predicted miRNA (hsa miR-378) suggesting the presence of the variant 'T' allele may result in an upregulation of GFPT2 contributing to diabetic renal complication. Epistatic interaction between SNPs in transforming growth factor TGF-beta1 (investigated using the same sample set and reported elsewhere) and GFPT2 genotype was observed.

CONCLUSIONS

Association of SNPs in RAGE and GFPT2 suggest that the genes involved in modulation of oxidative pathway could be major contributor to diabetic chronic renal insufficiency. In addition, GFPT2 mediated overproduction of TGF-beta1 leading to endothelial expansion and thereby CRI seems likely, suggested by our observation of a significant interaction between GFPT2 with TGF-beta1 genes. Further, identification of predicted miRNA targets spanning the associated SNP in GFPT2 implicates the rs7725 SNP in transcriptional regulation of the gene, and suggests GFPT2 could be a relevant target for pharmacological intervention. Larger replication studies are needed to confirm these observations.

The effect of plasminogen activator inhibitor-1 -675 4G/5G polymorphism on familial Mediterranean fever (FMF) disease

Familial Mediterranean fever (FMF) is an autosomal recessive disease that is the most common of a rare group of disorders collectively termed familial hereditary periodic fever syndromes, also known as autoinflammatory syndromes. FMF is predominantly affecting people of Mediterranean descent and clinically characterized by intermittent attacks of fever with peritonitis and abdominal pain, pleuritis, arthritis, or erysipelas-like rashes. Amyloidosis due to chronic inflammation progressing to renal failure is one of the most serious potential complications of this disease.Patients with inflammatory diseases, such as systemic lupus erythematosus and rheumatoid arthritis, and conditions with chronic subclinical inflammation, like obesity and diabetes mellitus, are now considered to have an increased risk of atherosclerotic cardiovascular complications. FMF is also an inflammatory disease, and it is accepted that even during attack-free periods significant inflammatory reaction continues. However, whether this inflammatory process causes premature atherosclerosis is not known due to a lack of data.Different studies have investigated the association between the fibrinolytic and inflammatory process parameters. PAI-1 is paracrine secretion of pro- and antiinflammatory cytokines, thereby playing a possible role in the adiposity-related inflammation and atherosclerosis. The patients with IRS have higher values of fibrinogen, factor VII, VIII, Von Willebrand factor and Plasminogen Activator Inhibitor (PAI) compared to control subjects. So that we aimed in this study to investigate whether FMF patients with/without amyloidosis and with M694V homozygote mutation, have increased risk for atherosclerotic cardiovascular complications and to determine the strength of association between MEFV gene-mutation types. To our knowledge, this is the first case control and cross-sectional study in the pediatric age groups.

Relationship Between Functional Promoter Polymorphism in the XBP1 Gene (-116C/G) and Obesity

Endoplasmic reticulum stress is a central feature of obesity, insulin resistance, and type 2 diabetes. A polymorphism of the XBP1 gene (-116C/G), a transcription factor that modulates the endoplasmic reticulum stress response, causes an impairment of its positive feedback system. The authors examined a role of the polymorphism in the development of obesity. The polymorphism was investigated in clinically obese children and compared with controls. Significant difference of genotype distribution was observed, which suggested that the -116C/G genotype may be a risk factor for at least pediatric obesity.

The genetics of gestational diabetes mellitus: evidence for relationship with type 2 diabetes mellitus

Gestational diabetes is a major public health problem because of its prevalence, its associated complications during pregnancy, and its increased risk for type 2 diabetes later in life. Insulin resistance is one of many physiological changes occurring during pregnancy, and when insulin resistance is accompanied by pancreatic beta-cell insufficiency, gestational diabetes may develop. Several lines of evidence suggest that gestational diabetes shares a common etiology with type 2 diabetes and support the hypothesis that gestational diabetes serves as a window to reveal a predisposition to type 2 diabetes. Pregnancy is an environmental stressor that may catalyze the progression to a diabetic state in genetically predisposed women; therefore, identification of these women during pregnancy could decrease the occurrence of type 2 diabetes through targeted prevention. This review presents an overview of the genetics of gestational diabetes, focusing on human association studies with candidate genes common to both type 2 diabetes and gestational diabetes.

Very low birth weight infants as a model to study genetic influences on neonatal weight gain

In a cohort of 829 preterm infants (birth weight below 1500 g) we identified 13 monozygotic, 10 same-sex dizygotic, and 12 same-sex matched singleton pairs. The difference in daily weight gain within pairs was significantly lower in monozygotic twins compared with dizygotic twins or matched singleton pairs. Our data support a strong genetic influence on postnatal growth in preterm infants. Therefore, weight gain of preterm infants may be an interesting model to study polymorphic variants of genes regulating neonatal resorption, metabolism, or energy expenditure, and their influence on weight gain in preterm infants.

The effect of plasminogen activator inhibitor-1 -675 4G/5G polymorphism on PAI-1 gene expression and adipocyte differentiation

Obesity is a complex, multifactorial chronic disease frequently associated with cardiovascular risks, hypertriglyceridemia, low high-density lipoprotein-cholesterol, high blood pressure, and the insulin resistance that appears to be central to the pathogenesis of Type II diabetes. Plasminogen activator inhibitor-1 expression induced in differentiating adipose tissue, but its role in adipogenesis and obesity is poorly understood. Circulating plasminogen activator inhibitor-1 levels are elevated at an early stage of impaired glucose tolerance, resulting in diabetes and metabolic syndrome. Plasminogen activator inhibitor-1 levels are also significantly elevated in the plasma of obese individuals and in adipose tissues of obese mice and humans. Some investigators proposed that the -675 4G/5G polymorphism in plasminogen activator inhibitor-1 promoter caused overexpression of this gene and predisposed carriers to obesity. In this study, we investigated the role of -675 4G/5G polymorphism in plasminogen activator inhibitor-1 promoter in the expression of this gene and the contribution of plasminogen activator inhibitor-1 to adipogenesis. Using a dual-luciferase promoter assay, we determined that the -675 4G/5G polymorphism contributes significantly to overexpression of plasminogen activator inhibitor-1 in the course of adipogenesis. The antidiabetic agents troglitazone and ciglitazone inhibited reporter gene expression driven by wild-type and -675 4G/5G mutant promoter, as well as the expression of endogenous plasminogen activator inhibitor-1, indicating that suppression of plasminogen activator inhibitor-1 expression may contribute to antidiabetic effects of these agents. The results indicate that absence of plasminogen activator inhibitor-1 in adipocytes may protect the cells against insulin resistance by promoting glucose uptake and adipocyte differentiation via a decrease in the peroxisome proliferator activated receptor-gamma expression that modulates the adipocyte differentiation.

Pediatric nonalcoholic fatty liver disease (NAFLD): a "growing" problem?

Nonalcoholic fatty liver disease (NAFLD) can affect both adults and children. With the current worldwide epidemic of pediatric obesity, pediatric NAFLD is increasingly being diagnosed. It is not exactly identical to NAFLD in adults, and these differences may be due in part to the occurrence of hepatic metabolic derangements typical of NAFLD during periods of active growth (infancy, mid-childhood and puberty). The natural history of pediatric NAFLD is not yet known; however, children with pediatric NAFLD can develop cirrhosis. Although details of disease mechanism in pediatric NAFLD remain unclear, hyperinsulinemia with insulin resistance appears to be critical. Determining the pathogenesis of pediatric NAFLD is likely to enhance our understanding of NAFLD in all age groups and may identify new treatment opportunities. Finding effective ways to prevent pediatric NAFLD is an important issue for children's health.

Biology of stem cells in human umbilical cord stroma: in situ and in vitro surveys

Cells in the umbilical cord stroma have gained attention in recent years; however, differentiation to certain lineages in humans has been demonstrated in few studies. Unlike bone marrow MSCs, human umbilical cord stroma cells (HUCSCs) are far from being well characterized. This study attempts to describe proliferation, structural, and differentiation properties of these cells to account for their exceptional nature in many aspects. Cellular dynamics, cellular structure, and the degree of transformations during expansion and differentiation into mesenchymal and neuronal lineages were examined in vitro over a 10-month period. Comparisons with human bone marrow MSCs regarding differentiation were performed. HUCSCs in culture revealed two distinct cell populations, type 1 and type 2 cells, that possessed differential vimentin and cytokeratin filaments. Corresponding cells were encountered in cord sections displaying region-specific localization. alpha-Smooth muscle actin and desmin filaments, which were evident in cord sections, diminished through passages. No difference was noted regarding type 1 and type 2 cells in differentiation to chondrogenic, adipogenic, and osteogenic lineages, whereas a preferential differentiation was noted in neuronal lineage. Relative success was achieved by production of chondrocytic spheres and osteogenic monolayers, whereas adipocytes were immature compared with bone marrow MSCs. The presence of neuronal markers suggests that they transform into a certain state of maturity under neurogenic induction. Conclusively, HUCSCs retain their original phenotype in culture without spontaneous differentiation, have a limited lifespan, and bear multipotent stem cell characteristics. Given these characteristics, they may be generally considered progenitor cells if manipulated under appropriate conditions and deserve further study to be potentially used in cell-based therapies.