Contribution of Genetic and Metabolic Syndrome to Omental Adipose Tissue PAI-1 Gene mRNA and Plasma Levels in Obesity

Association between plasminogen activator inhibitor-1 (PAI-1) 4G/5G polymorphism and risk of Alzheimer's disease, metabolic syndrome, and female infertility: A meta-analysis

BACKGROUND

Plasminogen activator inhibitor-1 (PAI-1) is considered to be involved in the physiopathological mechanisms of Alzheimer's disease (AD), metabolic syndrome (MetS), and female infertility. Previous studies investigating the association between PAI-14G/5G (rs1799889) gene polymorphism and the risk of AD, MetS, and female infertility have reported inconsistent results. The aim of the present study was to investigate possible associations.

METHODS

Eligible studies were retrieved through PubMed, Medline, EMBASE, CNKI, and WANFANG databases. The odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the associations. Subgroup analyses by ethnicity and mean age, sensitivity analyses, and publication bias were performed.

RESULTS

Five studies (four articles) for AD, six studies (six articles) for MetS, and four studies (four articles) for female infertility were included in this meta-analysis. Our results showed no significant associations between the PAI-14G/5G polymorphism and the risk of AD and female infertility in five genetic models. For the risk of MetS, the PAI-1 4G/5G (rs1799889) polymorphism may be associated with the risk of MetS (4G vs 5G, OR = 1.31, 95%CI = 1.04-1.64, P = .021), especially in Asians (4G/4G vs 4G/5G+5G/5G, OR = 1.38, 95%CI = 1.01-1.87, P = .041) and patients with mean age > 50 years old (4G/4G vs 4G/5G+5G/5G, OR = 1.36, 95%CI = 1.03-1.78, P = .029).

CONCLUSION

The present meta-analysis suggested that the PAI-1 4G/5G polymorphism might be associated with the risk of MetS, but no evidence was detected for AD and female infertility.

Effects of Long-term Thrombin Inhibition (Dabigatran Etexilate) on Spontaneous Thrombolytic Activity during the Progression of Atherosclerosis in ApoE-/--LDLR-/- Double-Knockout Mice

Background and Objectives

Atherosclerosis is characterized by a hypercoagulable state, during which coagulation and fibrinolytic factors are activated simultaneously. However, details regarding the thrombolytic pathway in this context remain unknown. Here we investigated how direct long-term inhibition of thrombin influenced spontaneous thrombolytic activity during atherosclerotic progression in apolipoprotein E (ApoE)^–/^––low density lipoprotein receptor (LDLR)^–/^– double-knockout mice.

Methods

All mice received either standard chow (placebo group) or dabigatran-containing chow for 22 weeks, after which we evaluated them. The amount of atherosclerosis was estimated as the ratio of the atherosclerotic area to the total aortic intimal area. In addition, we used immunohistochemistry to analyze the expression of tissue plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PAI-1), thrombin activatable fibrinolysis inhibitor (TAFI), and endothelial nitric oxide synthase (eNOS) in atherosclerotic regions. To evaluate thrombolysis, we used a He–Ne laser to induce thrombosis in vessels of the cremaster muscle and then measured the thrombus volume over time.

Results

The atherosclerotic area was smaller and thrombolytic activity greater in the dabigatran-treated group than in the placebo group. Furthermore, according to the thrombolysis model, spontaneous thrombolytic activity was increased in the dabigatran-treated mice compared with the placebo mice. In support of these results, immunohistochemistry demonstrated decreased expression of PAI-1 and TAFI but increased expression of eNOS in the dabigatran group compared with the placebo group. However, t-PA expression did not differ between groups.

Conclusions

Direct long-term inhibition by dabigatran etexilate of thrombin led to an increase in spontaneous thrombolytic activity decreasing the expression of PAI-1 and TAFI.

High ApoD protein level in the round ligament fat depot of severely obese women is associated with an improved inflammatory profile

PURPOSE

Apolipoprotein D (ApoD) is a lipocalin participating in lipid transport. It binds to a variety of ligands, with a higher affinity for arachidonic acid, and is thought to have a diverse array of functions. We investigated a potential role for ApoD in insulin sensitivity, inflammation, and thrombosis-processes related to lipid metabolism-in severely obese women.

METHODS

We measured ApoD expression in a cohort of 44 severely obese women including dysmetabolic and non-dysmetabolic patients. Physical and metabolic characteristics of these women were determined from anthropometric measurements and blood samples. ApoD was quantified at the mRNA and protein levels in samples from three intra-abdominal adipose tissues (AT): omental, mesenteric and round ligament (RL).

RESULTS

ApoD protein levels were highly variable between AT of the same individual. High ApoD protein levels, particularly in the RL depot, were linked to lower plasma insulin levels (-40%, p = 0.015) and insulin resistance (-47%, p = 0.022), and increased insulin sensitivity (+10%, p = 0.008). Lower circulating pro-inflammatory PAI-1 (-39%, p = 0.001), and TNF-α (-19%, p = 0.030) levels were also correlated to high ApoD protein in the RL AT.

CONCLUSIONS

ApoD variability between AT was consistent with different accumulation efficiencies and/or metabolic functions according to the anatomic location of fat depots. Most statistically significant correlations implicated ApoD protein levels, in agreement with protein accumulation in target tissues. These correlations associated higher ApoD levels in fat depots with improved metabolic health in severely obese women.

Association of SERPINE1 rs6092 with type 2 diabetes and related metabolic traits in a Chinese population

BACKGROUND

Plasminogen activator inhibitor-1 (PAI-I), encoded by SERPINE1 gene, is a member of the serine protease inhibitor superfamily, and polymorphisms in SERPINE1 have been reported to be associated with type 2 diabetes (T2D). This study investigated whether the polymorphism in PAI-I contribute to the risk for T2D.

METHODS

A 1:1 case-control study was conducted to investigate the association of rs6092 in SERPINE1 with T2D and diabetes-related metabolic traits, including body mass index, waist circumference (WC), triglyceride (TG), total cholesterol (TC), high density lipoprotein cholesterol, low density lipoprotein cholesterol, fasting plasma glucose and glycosylated hemoglobin (HbA1c) in a Chinese population, with a total of 1572 subjects (786 T2D patients and 786 healthy controls). The polymorphism was genotyped based on MassARRAY genotyping system.

RESULTS

The AA genotype and A allele of rs6092 exerted a protective effect on T2D risk (odds ratio (OR) = 0.431 and 0.630, respectively). In a recessive model, we also observed the protective association of rs6092 with T2D (OR = 0.195). The above associations were only observed in men. In female patients, there was a significant difference in HbA1c level between the AA homozygotes and GG homozygotes, as well as between the AA homozygotes and combined GG and GA genotypes. In male patients, the WC level in the subjects carrying AA genotype was lower than those in the subjects with GG genotype (P = 0.000), and the association was also significant in a recessive model (P = 0.000). Additionally, there was a significant difference in TG level between the AA homozygotes and GG homozygotes (P = 0.017), as well as the AA homozygotes and combined GG and GA genotypes (P = 0.032).

CONCLUSIONS

Our study suggests that the A allele and AA genotype of rs6092 may protect against T2D, and have a protective effect on WC, but a negative effect on TG in men, while may contribute to a lower HbA1c level in women.

Distinct Response of Fat and Gastrointestinal Tissue to Glucose in Gestational Diabetes Mellitus and Polycystic Ovary Syndrome

Gestational diabetes mellitus (GDM) and polycystic ovary syndrome (PCOS) are distinct pathologies with impaired insulin sensitivity as a common feature. The aim of this study was to evaluate the response of fat tissue adipokines and gastrointestinal incretins to glucose load in patients diagnosed with one of the two disorders and to compare it with healthy controls. Oral glucose tolerance test (oGTT) was performed in 77 lean young women: 22 had positive history of GDM, 19 were PCOS patients, and 36 were healthy controls. Hormones were evaluated in fasting and in 60 min intervals during the 3 h oGTT using Bio-Plex ProHuman Diabetes 10-Plex Assay for C-peptide, ghrelin, GIP, GLP1, glucagon, insulin, leptin, total PAI1, resistin, visfatin and Bio-Plex ProHuman Diabetes Adipsin and Adiponectin Assays (Bio-Rad). Despite lean body composition, both PCOS and GDM women were more insulin resistant than controls. Significant postchallenge differences between the GDM and PCOS groups were observed in secretion of adipsin, leptin, glucagon, visfatin, ghrelin, GIP, and also GLP1 with higher levels in GDM. Conversely, PCOS was associated with the highest resistin, C-peptide, and PAI1 levels. Our data suggest that decreased insulin sensitivity observed in lean women with GDM and PCOS is associated with distinct hormonal response of fat and gastrointestinal tissue to glucose load.

Gene expression in a rarely studied intraabdominal adipose depot, the round ligament, in severely obese women: A pilot study

Gene expression (qPCR) was compared in round ligament (RL), omental (OME) and mesenteric (MES) ATs from 48 severely obese women (BMI, 54±11 kg/m(2); 38±9 yrs). The mRNA levels of enzymes of lipid metabolism (LPL, HSL, and PDE-3B), cortisol production (11βHSD-1), adipogenesis (PPAR-γ1/2), thrombosis and inflammation (PAI-1, IL-6, TNF-α and adiponectin) were determined. AT-LPL mRNA was highest in RL. The highest PDE-3B and lowest PAI-1 mRNA levels were observed in RL and MES. The lowest IL-6 and TNF-α and the highest adiponectin and PPAR-g1/2 mRNA levels were found in RL AT. 11βHSD-1 was highest in RL and OME. A higher lipogenic and adipogenic, and lower pro-inflammatory and pro-thrombotic profiles of the RL suggest a lesser deleterious impact on obesity-related complications.

The Effect of PAI-1 4G/5G Polymorphism and Clinical Factors on Coronary Artery Occlusion in Myocardial Infarction

Objective. Data on the impact of PAI-1-675 4G/5G genotype for fibrinolysis during myocardial infarction are inconsistent. The aim of our study was to evaluate the association of clinical and genetic (PAI-1-675 4G/5G polymorphism) factors with coronary artery occlusion in patients with myocardial infarction. Materials and Methods. PAI-1-675 4G/5G detection was achieved by using Sanger sequencing in a sample of patients hospitalized for stent implantation due to myocardial infarction. We categorized the patients into two groups: patients with coronary artery occlusion and patients without coronary artery occlusion according to angiographic evaluation. Results. We identified n = 122 (32.4%) 4G/4G, n = 186 (49.5%) 4G/5G, and n = 68 (18.1%) 5G/5G PAI-1 genotype carriers. Univariate and multivariate analysis showed that only the 4G/5G genotype was associated with coronary artery occlusion (OR: 1.656 and 95% CI: 1.009–2.718, p = 0.046). Conclusions. Our results showed that carriers of PAI-1 4G/5G genotype with myocardial infarction have increased odds of coronary artery occlusion more than 1.6 times in comparison to the carriers of homozygous genotypes.

Whole genome sequencing of an ethnic Pathan (Pakhtun) from the north-west of Pakistan

Background

Pakistan covers a key geographic area in human history, being both part of the Indus River region that acted as one of the cradles of civilization and as a link between Western Eurasia and Eastern Asia. This region is inhabited by a number of distinct ethnic groups, the largest being the Punjabi, Pathan (Pakhtuns), Sindhi, and Baloch.

Results

We analyzed the first ethnic male Pathan genome by sequencing it to 29.7-fold coverage using the Illumina HiSeq2000 platform. A total of 3.8 million single nucleotide variations (SNVs) and 0.5 million small indels were identified by comparing with the human reference genome. Among the SNVs, 129,441 were novel, and 10,315 nonsynonymous SNVs were found in 5,344 genes. SNVs were annotated for health consequences and high risk diseases, as well as possible influences on drug efficacy. We confirmed that the Pathan genome presented here is representative of this ethnic group by comparing it to a panel of Central Asians from the HGDP-CEPH panels typed for ~650 k SNPs. The mtDNA (H2) and Y haplogroup (L1) of this individual were also typical of his geographic region of origin. Finally, we reconstruct the demographic history by PSMC, which highlights a recent increase in effective population size compatible with admixture between European and Asian lineages expected in this geographic region.

Conclusions

We present a whole-genome sequence and analyses of an ethnic Pathan from the north-west province of Pakistan. It is a useful resource to understand genetic variation and human migration across the whole Asian continent.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-015-1290-1) contains supplementary material, which is available to authorized users.

ADRB3 gene promoter DNA methylation in blood and visceral adipose tissue is associated with metabolic disturbances in men

AIM

ADRB3 DNA hypermethylation was recently associated with dyslipidemia in familial hypercholesterolemia (FH). In this study, we verified whether ADRB3 DNA methylation in blood and visceral adipose tissue (VAT) was associated with obesity and its related complications.

METHODS

DNA methylation levels were measured in the blood of 61 FH men, and the blood and VAT of 30 severely obese men. Common ADRB3 polymorphisms were genotyped in all subjects.

RESULTS

Higher ADRB3 DNA methylation levels were significantly associated with lower low-density lipoprotein cholesterol levels (r = -0.40; p = 0.01) in FH, and with a lower waist-to-hip ratio (r = -0.55; p = 0.01) and higher blood pressure (r = 0.43; p = 0.05) in severely obese men. ADRB3 g.-843C>T and p.W64R polymorphisms were found to be strongly associated (p < 0.001) with ADRB3 DNA methylation and mRNA levels.

CONCLUSION

Although further studies are needed, these results suggest that epigenetic changes at the ADRB3 gene locus might be involved in the development of obesity and its related metabolic complications.

Body adiposity but not insulin resistance is associated with -675 4G/5G polymorphism in the PAI-1 gene in a sample of Mexican children

OBJECTIVE

To assess whether the -675 4G/5G polymorphism in the plasminogen activator inhibitor-1 gene is associated with obesity and insulin resistance in Mexican children.

METHODS

A cross-sectional study was performed in 174 children, 89 with normal-weight and 85 with obesity, aged from 6 to 13 years. All children were from state of Guerrero, and recruited from three primary schools in the city of Chilpancingo, state of Guerrero, Mexico. Insulin levels were determined by immunoenzymatic assay. The homeostasis model assessment was used to determine insulin resistance. The -675 4G/5G polymorphism in PAI-1 gene was analyzed by polymerase chain reaction-restriction fragment length polymorphism.

RESULTS

The prevalence of insulin resistance in the obese group was higher (49.41%) than in the normal-weight group (16.85%). The 4G/5G PAI-1 polymorphism was found in Hardy Weinberg equilibrium. The 4G/5G genotype contributed to a significant increase in waist-hip ratio (β=0.02, p=0.006), waist circumference (β=4.42, p=0.009), and subscapular skinfold thickness (β=1.79, p=0.04); however, it was not related with insulin resistance.

CONCLUSION

The -675 4G/5G genotype of PAI-1 gene was associated with increase of body adiposity in Mexican children.

Adipocytes derived fibrinolytic components in peritoneum — a pilot study

The proteins of the fibrinolytic system — urokinase plasminogen activator(uPA), tissue plasminogen activator (tPA)and plasminogen activator inhibitor type IPAI-I) — play important roles in fibrotization in various organs and including peritoneum. To study the cellular localization of PAI-1, tPA and uPA within the adipose tissue of the peritoneal membrane in patients at the onset of peritoneal dialysis(PD) we determined the initial expression of these proteins in relationship to multiple clinical variables. Methods: routinely performed parietal peritoneal biopsies in 12 patients undergoing peritoneal catheter implantation were examined. We used formalinfixed, paraffin-embedded specimens for immunohistochemical localization of these proteins along with the stereological pointcounting method for quantification of their expression within the peritoneal adipose tissue. Results: strong positive mutual correlation between the expression of PAI-1 and both uPA (SpearmanR=0.66) and tPA (R=0.59) as well as between the expression of uPA and tPA (R=0.77) was found without any relatioship to BMI, age, peritoneal transport characteristic or diabetes status. Conclusion: Adipose tissue within the peritoneum is capable of producing fibrinolysis regulators (independently on clinical parameters) thus possibly affecting the fibrotization and function of peritoneum as dialysis membrane. The effect of dialysis solution dosing, composition and other dialysis related factors should be clarified in future studies.

Inflammatory and prothrombotic parameters in normotensive non-diabetic obese women: effect of weight loss obtained by gastric banding

Hypertension and diabetes are known risk factors for obesity-related thrombosis, but several studies have shown that obesity is characterised by a potentially prothrombotic inflammatory state because of activated coagulation and impaired fibrinolysis. In order to verify if obese patients-unaffected by hypertension, diabetes, dyslipidemia, cigarette smoking or inflammatory diseases-show increased prothrombotic markers and whether the weight loss induced by gastric banding normalises such parameters. Plasma levels of C reactive protein (CRP), fibrinogen, plasminogen activator inhibitor-1 (PAI-1), von Willebrand factor (VWF) and factor VII (FVII) were measured in 25 women with isolated obesity prior to, as well as 3, 6 and 12 months subsequent to gastric banding. Twenty-five healthy women served as a baseline control group. The obese women had higher CRP (p = 0.0001), fibrinogen (p = 0.014), PAI-1 (p = 0.003), VWF (p = 0.004) and FVII levels (p = 0.0001) than the normal controls, and their body mass index (BMI) positively correlated with CRP (r = 0.462, p = 0.02), fibrinogen (r = 0.426, p = 0.04) and PAI-1 (r = 0.468, p = 0.02). Twelve months after gastric banding, the median BMI had decreased from 40.0 to 34.9 (p = 0.0001); CRP from 4.18 to 1.69 μg/ml (p = 0.01); fibrinogen from 389 to 318 mg/dl (p = 0.0001); PAI-1 from 32.1 to 12.0 UI/ml (p = 0.003); VWF from 144 to 120% (p = 0.0001); and FVII from 134 to 112% (p = 0.002). Even in the absence of major cardiovascular risk factors, obese patients are characterised by a prothrombotic state. The weight loss induced by gastric banding decreases the parameters of inflammation, coagulation and impaired fibrinolysis, thus potentially reducing the thrombotic risk.

Relationship of metabolic syndrome and its components with -844 G/A and HindIII C/G PAI-1 gene polymorphisms in Mexican children

Background

Several association studies have shown that -844 G/A and HindIII C/G PAI-1 polymorphisms are related with increase of PAI-1 levels, obesity, insulin resistance, glucose intolerance, hypertension and dyslipidemia, which are components of metabolic syndrome. The aim of this study was to analyze the allele and genotype frequencies of these polymorphisms in PAI-1 gene and its association with metabolic syndrome and its components in a sample of Mexican mestizo children.

Methods

This study included 100 children with an age range between 6-11 years divided in two groups: a) 48 children diagnosed with metabolic syndrome and b) 52 children metabolically healthy without any clinical and biochemical alteration. Metabolic syndrome was defined as the presence of three or more of the following criteria: fasting glucose levels ≥ 100 mg/dL, triglycerides ≥ 150 mg/dL, HDL-cholesterol < 40 mg/dL, obesity BMI ≥ 95^th percentile, systolic blood pressure (SBP) and diastolic blood pressure (DBP) ≥ 95^th percentile and insulin resistance HOMA-IR ≥ 2.4. The -844 G/A and HindIII C/G PAI-1 polymorphisms were analyzed by PCR-RFLP.

Results

For the -844 G/A polymorphism, the G/A genotype (OR = 2.79; 95% CI, 1.11-7.08; p = 0.015) and the A allele (OR = 2.2; 95% CI, 1.10-4.43; p = 0.015) were associated with metabolic syndrome. The -844 G/A and A/A genotypes were associated with increase in plasma triglycerides levels (OR = 2.6; 95% CI, 1.16 to 6.04; p = 0.02), decrease in plasma HDL-cholesterol levels (OR = 2.4; 95% CI, 1.06 to 5.42; p = 0.03) and obesity (OR = 2.6; 95% CI, 1.17-5.92; p = 0.01). The C/G and G/G genotypes of the HindIII C/G polymorphism contributed to a significant increase in plasma total cholesterol levels (179 vs. 165 mg/dL; p = 0.02) in comparison with C/C genotype.

Conclusions

The -844 G/A PAI-1 polymorphism is related with the risk of developing metabolic syndrome, obesity and atherogenic dyslipidemia, and the HindIII C/G PAI-1 polymorphism was associated with the increase of total cholesterol levels in Mexican children.