Jadwiga Hartwich

A Low-Fat, High-Complex Carbohydrate Diet Supplemented with Long-Chain (n-3) Fatty Acids Alters the Postprandial Lipoprotein Profile in Patients with Metabolic Syndrome

Dietary fat intake plays a critical role in the development of metabolic syndrome (MetS). This study addressed the hypothesis that dietary fat quantity and quality may differentially modulate postprandial lipoprotein metabolism in MetS patients. A multi-center, parallel, randomized, controlled trial conducted within the LIPGENE study randomly assigned MetS patients to 1 of 4 diets: high-SFA [HSFA; 38% energy (E) from fat, 16% E as SFA], high-monounsaturated fatty acid [HMUFA; 38% E from fat, 20% E as MUFA], and 2 low-fat, high-complex carbohydrate [LFHCC; 28% E from fat] diets supplemented with 1.24 g/d of long-chain (LC) (n-3) PUFA (ratio 1.4 eicosapentaenoic acid:1 docosahexaenoic acid) or placebo (1.24 g/d of high-oleic sunflower-seed oil) for 12 wk each. A fat challenge with the same fat composition as the diets was conducted pre- and postintervention. Postprandial total cholesterol, triglycerides (TG), apolipoprotein (apo) B, apo B-48, apo A-I, LDL-cholesterol, HDL-cholesterol and cholesterol, TG, retinyl palmitate, and apo B in TG-rich lipoproteins (TRL; large and small) were determined pre- and postintervention. Postintervention, postprandial TG (P < 0.001) and large TRL-TG (P = 0.009) clearance began earlier and was faster in the HMUFA group compared with the HSFA and LFHCC groups. The LFHCC (n-3) group had a lower postprandial TG concentration (P < 0.001) than the other diet groups. Consuming the LFHCC diet increased the TG (P = 0.04), large TRL-TG (P = 0.01), TRL-cholesterol (P < 0.001), TRL-retinyl palmitate (P = 0.001), and TRL-apo B (P = 0.002) area under the curve compared with preintervention values. In contrast, long-term ingestion of the LFHCC (n-3) diet did not augment postprandial TG and TRL metabolism. In conclusion, postprandial abnormalities associated with MetS can be attenuated with LFHCC (n-3) and HMUFA diets. The adverse postprandial TG-raising effects of long-term LFHCC diets may be avoided by concomitant LC (n-3) PUFA supplementation to weight-stable MetS patients.

Regulation of platelet adhesion by oxidized lipoproteins and oxidized phospholipids.

Activated platelets adhere to the endothelium and release vasoactive mediators which induce vasoconstriction and remodeling of the vessel wall. The influence of native and ex vivo oxidized lipoproteins enriched with oxidized 1-palmitoyl-2-arachidonoyl- sn -glycero-3-phosphorylcholine (ox-PAPC), the major lipid responsible for the biological activity of minimally oxidized LDL (mm-LDL), on platelet adhesion, membrane receptor expression and aggregation was studied. Influence of native and oxidized lipoproteins (5-100 w g protein/ml); ox-PAPC (0.5-50 w g/ml); ADP (1-10 w M) as well as the specific phosphatase 1 and 2A inhibitor okadaic acid (3-10 w M) on platelet adhesion, receptor expression and aggregation was measured. Platelets adhered to all the classes of lipoproteins immobilized in plastic microtiter wells (native lipoproteins: HDL<LDL<VLDL<oxidized lipoproteins<ox-PAPC-enriched lipoproteins). Flow cytometry revealed that lipoproteins increased CD41 expression. Preincubation of platelets with ox-PAPC alone, significantly up-regulated CD62p and CD41 receptors (higher dose) but potently inhibited anti-CD36 MoAb binding. Okadaic acid increased anti-CD41 and decreased anti-CD36 and anti-CD42b MoAbs binding. Neither ox-PAPC nor okadaic acid induced platelet aggregation. CD36 seems to be the main receptor responsible for binding of oxidized lipoproteins, particularly its ox-PAPC epitope. The effect of okadaic acid on CD36 and CD41 argue for the participation of phosphorylation-dependent reorganization of cellular trafficking and microtubule organization by ox-PAPC.

LDL phenotype B and other lipid abnormalities in patients with large vessel disease and small vessel disease.

BACKGROUND AND PURPOSE Controversies concerning the significance of lipid abnormalities in stroke come mostly from the researches that studied lipid profile without considering stroke aetiologies. We investigated the prevalence of LDL phenotype B and other lipid abnormalities in stroke survivors with large vessel disease (LVD) or small vessel disease (SVD) (TOAST criteria) and in control subjects (CS). METHODS We studied 30 patients with LVD and 41 patients with SVD screened out of 585 stroke patients and 30 CS who fulfilled the following exclusion criteria: cardiac disorders, renal or hepatic failure, diabetes mellitus, or treatment with lipid-lowering agents. At least 3 months after stroke, the concentrations of total cholesterol (TC), HDL cholesterol (HDL-C), LDL cholesterol (LDL-C), triglycerides (TGs), apolipoprotein E (apoE), and lipoprotein (a) [lp(a)] were measured and LDL phenotypes and apoE isoforms were identified. RESULTS Patients with LVD had significantly higher concentrations of LDL-C than CS (p<0.05). They had higher concentrations of TGs and lower concentrations of HDL-C than patients with SVD and CS (p<0.05). LDL phenotype B was more frequent in patients with LVD (63.3%) than in patients with SVD (39.0%) or in CS (16.7%) (p<0.05). The concentration of apoE was higher in patients with LVD than in patients with SVD or in CS (p<0.05). The percentage of patients with increased level of lp(a) (i.e., >30 mg/ml) was greater in patients with LVD (36.7%) than in CS (10%) (p<0.05). CONCLUSIONS Patients with stroke due to LVD, but not SVD, have high prevalence of atherogenic lipid abnormalities, including increased frequency of LDL phenotype B and higher percentage of increased lp(a) level, like patients with other atherogenic diseases.

β-Carotene stimulates chemotaxis of human endothelial progenitor cells

Abstract Angiogenesis is a crucial process in tissue remodeling during growth, both in the embryo and the adult. In our study we concentrated on the direct effect of β-carotene on human umbilical cord originating from endothelial progenitor cells (EPCs). β-Carotene uptake by EPCs was measured using a HPLC method. The determination of cell surface antigens was performed by flow cytometry. The effect on cell proliferation was estimated by measuring bromo-deoxyuridine incorporation. The influence on the formation of a tubular-like structure was investigated in a 3D assay in matrigel. Quantitative gene expression was estimated using real-time PCR. We demonstrated that β-carotene in the physiological range of concentrations found in human blood is a potent activator of EPC chemotaxis, which is accompanied by a change in the expression of genes mediating cell adhesion and homing, but does not activate the final markers of endothelial differentiation. This study points to the prochemotactic and homing activity of β-carotene in undifferentiated endothelial cell progenitors for the first time, which may suggest a potential role of this carotenoid in progenitor cell therapy aimed at angiogenesis and tissue repair.

Lipoprotein profile, plasma Ischemia Modified Albumin and LDL density change in the course of postprandial lipemia. Insights from the LIPGENE study

Abstract Postprandial lipemia is associated with elevated risk of cardiovascular disease. Very little data exists regarding postprandial response in subjects with metabolic syndrome (MetS). The current study was conducted within the LIPGENE EU Integrated Project. Patients were randomized to one of the four isocaloric fatty meals (Oral Fat Tolerance Tests, OFTT): (A) high-fat, saturated fatty acid (SFA)-rich (HFSA), (B) high-fat, monounsaturated fatty acid (MUFA)-rich (HFMUFA), (C) low-fat, high-complex carbohydrate with 1.24 g high oleic sunflower oil supplement (LFHCC) and (D) low-fat high-complex carbohydrate with 1.24 g long chain n-3 poly-unsaturated fatty acid (LC n-3 PUFA) supplement (LFHCCn-3). The total and incremental areas under the curve (tAUC and iAUC) of plasma lipid and lipoprotein, Ischemia Modified Albumin (IMA) and LDL density were examined in patients with MetS to define effect of OFTT. All types of OFTT transiently increased plasma triglyceride and LDL density (LDLdens). It was paralleled by temporal decrease in total cholesterol (TC), LDL cholesterol (LDL-C), and HDL cholesterol (HDL-C). This last effect was partly alleviated in LFHCCn-3 test. A reversible increase of IMA was statistically significant only in the course of HSFA and HMUFA tests. EPA and DHA supplement in combined high complex-carbohydrate meal may attenuate adverse effect of tested meal on LDL particle profile and plasma ischemia modified albumin. No expected associations between measures of central adiposity (waist, WHR), adipose tissue insulin resistance (Adipo-IR), and postprandial responses of TG, TC, LDL-C, HDL-C, LDLdens and IMA/Alb ratio were found in subgroup analysis. Trial registration: ClinicalTrials.gov identifier: NCT00429195.

The effect of the plasma n-3/n-6 polyunsaturated fatty acid ratio on the dietary LDL phenotype transformation – Insights from the LIPGENE study

BACKGROUND & AIMS LDL phenotype B is associated with obesity, insulin resistance, hypertriglyceridemia and oxidative stress. The effect of plasma n-3/n-6 PUFA ratio on LDL phenotype transformation was investigated. METHODS Patients with metabolic syndrome (n=99) received one of four isocaloric diets: (A) High-fat (38% energy) SFA-rich diet (HSFA); (B) High-fat (38% energy), MUFA-rich diet (HMUFA); (C), low-fat (LF) (28% energy), high-complex carbohydrate diet with 1.24g/d oleic sunflower oil (LFHCC) and (D): low-fat (28% energy), high-complex carbohydrate diet, with 1.24g/d LC n-3 PUFA (LFHCC n-3) for 12 weeks. Analysis of plasma lipid profile and LDL phenotype was done pre- and post-interventions. RESULTS Post-dietary change of LDL density was a main effect observed in all groups. LFHCC n-3 and HFMUFA diets resulted in favorable alteration of LDL phenotype from B to A and decreased LDL density. In contrast, increased LDL density was observed in HSFA and LFHCC groups. The plasma pre-n3/n6 PUFA, Apo E change and pre-Apo CIII/CII ratios explained in 65% the post-dietary change of LDL density in diet LFHCC n-3 consumers. CONCLUSIONS Study demonstrates efficacy of dietary n-3 PUFA to modify pro-atherogenic to less atherogenic LDL phenotype in patients with metabolic syndrome. Study identifier at ClinicalTrials.gov was NCT00429195.

The Microarray Expression Analysis Identifies BAX as a Mediator of β-Carotene Effects on Apoptosis

Abstract: β-Carotene is a ubiquitous compound rich in foods. However, there are conflicting reports regarding its role in carcinogenesis. We performed a microarray expression analysis in normal [human umbilical vein endothelial cells (HUVECs)] and neoplastic (melanoma A375 and myelomonocytic leukemia U937) actively proliferating cells and found evidence that β-carotene stimulated vital cellular functions in the former and suppressed them in the latter. These differential effects correlated with the expression of the proapoptotic BCL2-associated X protein (BAX), which was downregulated in HUVECs and upregulated in the two neoplastic cell lines. The quantitative expression analysis using real-time polymerase chain reaction largely confirmed the inhibition of B-cell CLL/lymphoma 2 (BCL2) pathway-mediated apoptosis in HUVECs and its activation in melanoma and leukemic cells. The assays for apoptosis, detecting DNA breaks and caspase activation, showed consistent proapoptotic and antiapoptotic effects in U937 and HUVEC lines, respectively. However, β-carotene–induced expression changes of BAX and other BCL2 pathway genes did not lead to the predicted induction of apoptosis in the A375 cells.

Analysis of candidate genes in Polish families with obesity.

Abstract This study analyzes the relationship between risk factors related to overweight/obesity, insulin resistance, lipid tolerance, hypertension, endothelial function and genetic polymorphisms associated with: i) appetite regulation (leptin, melanocortin-3-receptor (MCR-3), dopamine receptor 2 (D2R)); ii) adipocyte differentiation and insulin sensitivity (peroxisome proliferator-activated receptor-γ2 (PPAR-γ2), tumor necrosis factor-α (TNF-α)); iii) thermogenesis and free fatty acid (FFA) transport/catabolism (uncoupling protein-1 (UCP1), lipoprotein lipase (LPL), β2- and β3-adrenergic receptor (β2AR, β3AR), fatty acid transport protein-1 (FATP-1) and iv) lipoproteins (apoliprotein E (apoE), apo CIII). The 122 members of 40 obese Caucasian families from southern Poland participated in the study. The genotypes were analyzed by restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR) or by direct sequencing. Phenotypes related to obesity (body mass index (BMI), fat/lean body mass composition, waist-to-hip ratio (WHR)), fasting lipids, glucose, leptin and insulin, as well as insulin during oral glucose tolerance test (OGTT) (4 points within 2 hours) and during oral lipid tolerance test (OLTT) (5 points within 8 hours) were assessed. The insulin sensitivity indexes: homeostasis model assessment of insulin resistance, whole body insulin sensitivity index, hepatic insulin sensitivity and early secretory response to an oral glucose load (HOMA-IR, ISI-COMP, ISI-HOMA and DELTA) were calculated. The single gene mutations such as C105 T OB and Pro115 Gln PPAR-γ2 linked to morbid obesity were not detected in our group. A weak correlation between obesity and certain gene polymorphisms was observed. Being overweight (25<BMI≤30 kg/m2) significantly correlated with worse FFA tolerance in male PPAR-γ2 12Pro, LPL-H (G) allele carriers. Insulin resistance was found in female PPAR-γ2 Pro12, TNF-α (−308A) and LPL-H (G) allele carriers. Hypertension linked to the PPAR-γ2 Pro allele carriers was characterized by high leptin output during OLTT. We conclude that the polymorphisms we investigated were weakly correlated with obesity but significantly modified the risk factors of the metabolic syndrome.

Constitutive nitric oxide synthase activity in the prefrontal cortex of rats as an index of emotional state before death.

The prefrontal cortex (PFC), as a part of the ’limbic circuit’, plays a fundamental role in emotional and cognitive processes (Lane et al., 1997; Maguire et al., 1998). This has been shown both in experimental animal models and in humans, using modem imaging techniques (Lane et al., 1997; Maguire et al., 1998; Middleton & Strick, 1997). Numerous excitatory amino acids (EAA) neurons are present in PFC, and glutamate plays a key role in excitatory neurotransmission in the central nervous system (McDonald, 1996). Nitric oxide (NO) plays a significant, indirect role in the stimulation of glutamate receptors, particularly the ionotropic (iGluR) and metabotropic (mGluR) glutamate receptor types. The stimulation of both types of glutamate receptors increases after the generation of NO (Gage et al, 1997; Kendrick et al., 1997), indicating that NO may act as a modulator of glutamatergic neurotransmission. Both glutamate and the activity of the enzyme NO-synthase (NOS) respond to noxious, stressful environmental influences. An increased level of

An inhibitory effect of camonagrel-a new thromboxane synthase inhibitor, on P-selectin-mediated platelet/PMN adhesion.

P-selectin (PADGEM protein, GMP-140 or CD 62) is a glycoprotein of platelet a-granules and endothelial Weibel-Palade bodies that, by mediating cellular adhesion, initiates recruitment of leukocytes and lymphocytes into injured tissue. Both of the endothelial antiplatelet autacoids prostacyclin (PGI(2)) and nitric oxide (NO) have been demonstrated to inhibit P-selectin expression. Prostaglandin endoperoxides PGG(2)/PGH(2) that are generated by activated platelets have been demonstrated to be used by endothelium for generation of prostacyclin. In an experimental model in vitro that resembles vessel wall/platelet/PMN interaction in vivo, we found that aspirin (100 μM), a COX inhibitor, but not L-NMMA (100 μM) and a NO-synthase inhibitor, reversed the inhibitory effect of arterial wall on P-selectin mediated platelet/PMN adhesion. The anti-adhesive potency of vessel wall reversed by aspirin was dose-dependently restored by camonagrel (3-100 μM), a new TXA(2) synthase inhibitor. We conclude that selective TXA(2)-synthase inhibitors may inhibit P-selectin mediated platelet/PMN adhesion by augmenting formation of prostacyclin by vessel walls.