Euphausia pacifica (North Pacific Krill): Review of Chemical Features and Potential Benefits of 8-HEPE against Metabolic Syndrome, Dyslipidemia, NAFLD, and Atherosclerosis.

Marine n-3 fatty acids are well known to have health benefits. Recently, krill oil, which contains phospholipids, has been in the spotlight as an n-3 PUFA-containing oil. Euphausia pacifica (E. pacifica), also called North Pacific krill, is a small, red crustacean similar to shrimp that flourishes in the North Pacific Ocean. E. pacifica oil contains 8-hydroxyeicosapentaenoic acid (8-HEPE) at a level more than 10 times higher than Euphausia superba oil. 8-HEPE can activate the transcription of peroxisome proliferator-activated receptor alpha (PPARα), PPARγ, and PPARδ to levels 10, 5, and 3 times greater than eicosapentaenoic acid, respectively. 8-HEPE has beneficial effects against metabolic syndrome (reduction in body weight gain, visceral fat area, amount of gonadal white adipose tissue, and gonadal adipocyte cell size), dyslipidemia (reduction in serum triacylglycerol and low-density lipoprotein cholesterol and induction of serum high-density lipoprotein cholesterol), atherosclerosis, and nonalcoholic fatty liver disease (reduction in triglyceride accumulation and hepatic steatosis in the liver) in mice. Further studies should focus on the beneficial effects of North Pacific krill oil products and 8-HEPE on human health.

The association between peroxisome proliferator-activated receptor Δ rs3777744, rs3798343, and rs6922548 and coronary artery disease.

Objective: The aim of the present study is to investigate the association between the single nucleotide polymorphism (SNP) sites of peroxisome proliferator-activated receptor Δ (PPARD) and the risk of coronary artery disease (CAD). To this end, a prospective observational single-center study of the clinical data from 880 subjects in a Chinese population was conducted. Methods: A total of 880 subjects, including 609 CAD patients and 271 control subjects, were selected for the present study. All inpatients had 4 ml of venous blood drawn after 12 h of fasting, and then clinical tests were conducted to obtain the biochemical parameters. CAD patients and Controls were distinguished by coronary angiography. Statistical analysis was conducted with SPSS software (ver 16.0). Results: A significant association between the G-alleles of PPARD rs3777744 and rs3798343 and a decreased risk for CAD was found. Moreover, we found an interaction between high fasting high-density lipoprotein cholesterol (HDL-C) serum levels, low serum glucose levels and their genotypes, ultimately decreasing the risk of CAD. Haplotype analysis was conducted on the three SNP sites, rs3777744 and rs3798343 to form a block [r2 = 0.79, D' = 0.99). The A-C haplotypes were associated with an increased risk of CAD (odds ratio (OR), 95% confidence interval (CI): 1.321 (1.060-1.647), P=0.013], and the G-G haplotypes were associated with a decreased risk [OR, 95% CI: 0.714 (0.567-0.849), P=0.004]. Conclusions: Our study indicates a significant association between the G-alleles of PPARD rs3777744 and rs3798343 and a decreased CAD risk. In addition, genotypes interact with high serum HDL-C levels and low serum glucose levels, resulting in decreased prevalence of CAD.

Associations between hypertension and the peroxisome proliferator-activated receptor-δ (PPARD) gene rs7770619 C>T polymorphism in a Korean population.

BACKGROUND: Oxidative stress is associated with the increased risk of hypertension (HTN). This cross-sectional study is aimed to identify the association between the peroxisome proliferator-activated receptor-δ (PPARD) polymorphism and plasma malondialdehyde (MDA), an oxidative stress marker which is related to HTN development, and to determine whether PPARD gene is a candidate gene for HTN. RESULTS: One thousand seven hundred ninety-three individuals with normal blood pressure (BP) and HTN were included in this cross-sectional study. The Korean Chip was used to obtain genotype data. Through the analysis, the ten most strongly associated single-nucleotide polymorphisms (SNPs) were nominated for an MDA-related SNP. Among them, the rs7770619 polymorphism was identified in the PPARD gene. The CT genotype of the PPARD rs7770619 C>T polymorphism was associated with a lower risk of HTN before and after adjustments for age, sex, body mass index, smoking, and drinking. Significant associations were observed between plasma MDA and the PPARD rs7770619 C>T polymorphism and between systolic BP and the PPARD rs7770619 SNP in the controls. The CT controls showed significantly lower systolic BP and plasma MDA than the CC controls. Additionally, in both controls and HTN patients, the CT subjects showed significantly lower serum glucose and higher adiponectin levels than the CC subjects. Furthermore, the CT subjects showed significantly higher serum free fatty acid levels than the CC subjects among the HTN patients. CONCLUSION: This is a new finding that the PPARD rs7770619 C>T SNP is a novel candidate variant for HTN based on the association between PPARD and plasma MDA in a Korean population.

Deregulation of PPARß/δ target genes in tumor-associated macrophages by fatty acid ligands in the ovarian cancer microenvironment.

The nuclear receptor peroxisome proliferator-activated receptor ß/δ (PPARß/δ) is a lipid ligand-inducible transcription factor associated with macrophage polarization. However, its function in tumor-associated macrophages (TAMs) has not been investigated to date. Here, we report the PPARß/δ-regulated transcriptome and cistrome for TAMs from ovarian carcinoma patients. Comparison with monocyte-derived macrophages shows that the vast majority of direct PPARß/δ target genes are upregulated in TAMs and largely refractory to synthetic agonists, but repressible by inverse agonists. Besides genes with metabolic functions, these include cell type-selective genes associated with immune regulation and tumor progression, e.g., LRP5, CD300A, MAP3K8 and ANGPTL4. This deregulation is not due to increased expression of PPARß/δ or its enhanced recruitment to target genes. Instead, lipidomic analysis of malignancy-associated ascites revealed high concentrations of polyunsaturated fatty acids, in particular linoleic acid, acting as potent PPARß/δ agonists in macrophages. These fatty acid ligands accumulate in lipid droplets in TAMs, thereby providing a reservoir of PPARß/δ ligands. These observations suggest that the deregulation of PPARß/δ target genes by ligands of the tumor microenvironment contributes to the pro-tumorigenic polarization of ovarian carcinoma TAMs. This conclusion is supported by the association of high ANGPTL4 expression with a shorter relapse-free survival in serous ovarian carcinoma.

Peroxisome proliferator receptor (PPAR) ß/δ in psoriatic patients before and after two conventional therapeutic modalities: methotrexate and PUVA.

Peroxisome proliferator-activated receptor ß/δ is a member of the nuclear hormone receptor superfamily suggested to contribute to psoriasis pathogenesis. Methotrexate and PUVA mainly target the T cell-mediated immunopathology of psoriasis. Our work aimed at estimating PPARß/δ in psoriatic patients and investigating whether the standard therapeutic modalities (methotrexate and PUVA) exert their anti-psoriatic activity partially through altering PPARß/δ levels. RT-PCR was used to measure PPAR ß/δ mRNA levels in twenty four chronic plaque psoriasis patients. Patients were divided into two groups (12 patients each); group A received intramuscular methotrexate and group B was treated by PUVA 3 times/week in a PUVA 1000 cabin for ten weeks each, followed by measurement of PPAR ß/δ mRNA levels. Twelve healthy volunteers served as controls. PPAR ß/δ mRNA levels were significantly elevated in all patients and significantly decreased ten weeks after treatment, however, post treatment levels were still significantly elevated in comparison with those of controls. PPAR ß/δ mRNA levels showed a significant positive correlation with disease duration.

The peroxisome proliferator-activated receptor delta +294T/C polymorphism in relation to lipoprotein metabolism in patients with diabetes mellitus type 2 and in non-diabetic controls.

OBJECTIVE: Peroxisome proliferator-activated receptor delta (PPARdelta) is an ubiquitously expressed transcription factor that has been implicated in the regulation of genes related to cholesterol metabolism. Conflicting results exist regarding the association of the recently described +294T/C polymorphism in the 5'-untranslated region (5'-UTR) in exon 4 of the PPARdelta gene and plasma lipoprotein concentrations. Purpose of the present study was to examine for the first time in a German population and for the first time also in women the presence of a potential association between the aforementioned polymorphism and lipoprotein concentrations in patients with diabetes mellitus type 2 (DM-2) and in non-diabetic controls. Furthermore, a possible gene-gene interaction between the PPARdelta +294T/C polymorphism and the PPARalpha L162V polymorphism was examined. DESIGN AND METHODS: We determined by PCR the polymorphism in a total of 402 patients with DM-2 (230 men and 172 women) and in 436 healthy controls (248 men and 188 women) from the LIANCO study (lipid analytic cologne). RESULTS: The genotype distribution was not different between DM-2 and controls (+294TT 65.6% versus 66.7%, +294TC 30.5% versus 29.4%, +294CC 3.9 versus 4.0%, respectively). There was no difference in the low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C) or triglyceride (TG) concentrations between carriers and non-carriers of the rare C allele in the DM-2 population. In specific, the heterozygotes for the C allele had LDL-C concentrations of 157+/-80 mg/dl, HDL-C of 54+/-17 mg/dl and TG of 273+/-507 mg/dl, while the C allele homozygotes had concentrations of LDL-C 149+/-44 mg/dl, HDL-C of 59+/-21 mg/dl and TG of 197+/-110 mg/dl. The LDL-C, HDL-C and TG concentrations of TT homozygotes were 156+/-49 mg/dl, 56+/-18 mg/dl and TG 225+/-242 mg/dl, respectively. The same lack of association was present in the non-diabetic controls, both in men and in women. There was no association between the genotypes and body mass index. Furthermore, no gene-gene interaction between the PPARdelta +294TC and the PPARalpha L162V polymorphism was observed regarding lipoprotein concentrations and atherosclerotic disease. CONCLUSIONS: The data suggest that the PPARdelta +294T/C polymorphism has no influence on plasma lipoprotein concentrations, body mass index or atherosclerotic disease either in healthy subjects or in patients with DM-2, both in males and females.