Lysophosphatidylcholine induces expression of genes involved in cholesterol biosynthesis in THP-1 derived macrophages.

Lysophosphatidylcholine (LPC), a major component of oxidized low-density lipoprotein, is associated with atherosclerosis, obesity, stroke, and cancer. However, the direction and mechanism of this relationship remains unclear. In this study, we conducted RNA profiling in THP-1 derived macrophages treated with LPC and uncovered a relationship between LPC and the cholesterol biosynthesis pathway. Principal component analysis (PCA) of RNA profiling showed that untreated THP-1 cells and those treated with 10, 20, or 40 µM LPC were distinctly distributed. Functional annotation revealed that LPC affected the expression of genes involved in cytokine-cytokine receptor interaction, TNF signaling, and MAPK signaling. Interestingly, LPC also altered the expression of 11 genes involved in cholesterol synthesis such as those in terpenoid backbone biosynthesis and steroid biosynthesis pathways. This increased gene expression occurred in a dose-dependent manner in response to LPC treatment. Especially, LPC with saturated acyl groups enhanced the expression of these genes compared to LPC with unsaturated acyl groups, and similar results were shown in response to saturated and unsaturated free fatty acids. Our findings demonstrate that LPCs with saturated acyl groups induce the expression of genes involved in cholesterol biosynthesis and may have implications for cholesterol related diseases.

Serum low-density lipoprotein and low-density lipoprotein expression level at diagnosis are favorable prognostic factors in patients with small-cell lung cancer (SCLC).

BACKGROUND: Patients with small-cell lung cancer (SCLC) patients demonstrate varied survival outcomes. Previous studies have reported that lipoproteins are associated with prognosis in various cancers; however, the role of low-density lipoprotein (LDL) and low-density lipoprotein- cholesterol (LDLR) in patients with SCLC has not been studied. METHODS: In this study, the impact of LDL and LDLR on the prognosis of SCLC patients was evaluated. A total of 601 patients with SCLC were retrospectively evaluated, in which 198 patients had adequate tissues for immunohistochemistry, and serum LDL and LDLR expression levels at baseline were tested. X-tile tool, and univariate and multivariate Cox analysis were used to assess the association between LDL, LDLR and overall survival (OS). RESULTS: Univariate analysis demonstrated that a lower LDL level was significantly associated with superior OS (P = 0.037). Similarly, LDLR also significantly predicted OS (P = 0.003). Multivariate Cox analyses confirmed that lower LDL and LDLR expression was independent prognostic factors associated with longer OS (P = 0.019 and P = 0.027, respectively). CONCLUSIONS: This study showed that both LDL and LDLR are prognostic indexes for survival in patients with SCLC. Patients with high LDL or LDLR expression level may benefit from treatment that modulates lipoprotein combined with platinum-based chemotherapy.

Proposed pathophysiologic framework to explain some excess cardiovascular death associated with ambient air particle pollution: Insights for public health translation.

The paper proposes a pathophysiologic framework to explain the well-established epidemiological association between exposure to ambient air particle pollution and premature cardiovascular mortality, and offers insights into public health solutions that extend beyond regulatory environmental protections to actions that can be taken by individuals, public health officials, healthcare professionals, city and regional planners, local and state governmental officials and all those who possess the capacity to improve cardiovascular health within the population. The foundation of the framework rests on the contribution of traditional cardiovascular risk factors acting alone and in concert with long-term exposures to air pollutants to create a conditional susceptibility for clinical vascular events, such as myocardial ischemia and infarction; stroke and lethal ventricular arrhythmias. The conceptual framework focuses on the fact that short-term exposures to ambient air particulate matter (PM) are associated with vascular thrombosis (acute coronary syndrome, stroke, deep venous thrombosis, and pulmonary embolism) and electrical dysfunction (ventricular arrhythmia); and that individuals having prevalent heart disease are at greatest risk. Moreover, exposure is concomitant with changes in autonomic nervous system balance, systemic inflammation, and prothrombotic/anti-thrombotic and profibrinolytic-antifibrinolytic balance. Thus, a comprehensive solution to the problem of premature mortality triggered by air pollutant exposure will require compliance with regulations to control ambient air particle pollution levels, minimize exposures to air pollutants, as well as a concerted effort to decrease the number of people at-risk for serious clinical cardiovascular events triggered by air pollutant exposure by improving the overall state of cardiovascular health in the population. This article is part of a Special Issue entitled Air Pollution, edited by Wenjun Ding, Andrew J. Ghio and Weidong Wu.

Fine particulate matter air pollution and atherosclerosis: Mechanistic insights.

BACKGROUND: Atherosclerosis is a progressive disease characterized by the accumulation of lipids and fibrous plaque in the arteries. Its etiology is very complicated and its risk factors primarily include genetic defects, smoking, hyperlipidemia, hypertension, lack of exercise, and infection. Recent studies suggest that fine particulate matter (PM2.5) air pollution may also contribute to the development of atherosclerosis. SCOPE OF REVIEW: The present review integrates current experimental evidence with mechanistic pathways whereby PM2.5 exposure can promote the development of atherosclerosis. MAJOR CONCLUSIONS: PM2.5-mediated enhancement of atherosclerosis is likely due to its pro-oxidant and pro-inflammatory effects, involving multiple organs, different cell types, and various molecular mediators. GENERAL SIGNIFICANCE: Studies about the effects of PM2.5inhalation on atherosclerosis may yield a better understanding of the link between air pollution and major cardiovascular diseases, and provide useful information for policy makers to determine acceptable levels of PM2.5 air quality. This article is part of a Special Issue entitled Air Pollution, edited by Wenjun Ding, Andrew J. Ghio and Weidong Wu.

Inflammatory intracellular pathways activated by electronegative LDL in monocytes.

AIMS: Electronegative LDL (LDL(-)) is a plasma LDL subfraction that induces cytokine release in monocytes through toll-like receptor 4 (TLR4) activation. However, the intracellular pathways induced by LDL(-) downstream TLR4 activation are unknown. We aimed to identify the pathways activated by LDL(-) leading to cytokine release in monocytes. METHODS AND RESULTS: We determined LDL(-)-induced activation of several intracellular kinases in protein extracts from monocytes using a multikinase ELISA array. LDL(-) induced higher p38 mitogen-activated protein kinase (MAPK) phosphorylation than native LDL. This was corroborated by a specific cell-based assay and it was dependent on TLR4 and phosphoinositide 3-kinase (PI3k)/Akt pathway. P38 MAPK activation was involved in cytokine release promoted by LDL(-). A specific ELISA showed that LDL(-) activated cAMP response-element binding (CREB) in a p38 MAPK dependent manner. P38 MAPK was also involved in the nuclear factor kappa-B (NF-kB) and activating protein-1 (AP-1) activation by LDL(-). We found that NF-kB, AP-1 and CREB inhibitors decreased LDL(-)-induced cytokine release, mainly on MCP1, IL6 and IL10 release, respectively. CONCLUSIONS: LDL(-) promotes p38 MAPK phosphorylation through TLR4 and PI3k/Akt pathways. Phosphorylation of p38 MAPK is involved in NF-kB, AP-1 and CREB activation, leading to LDL(-)-induced cytokine release in monocytes.

Study of Valproic Acid-Enhanced Hepatocyte Steatosis.

Valproic acid (VPA) is one of the most widely used antiepilepsy drugs. However, several side effects, including weight gain and fatty liver, have been reported in patients following VPA treatment. In this study, we explored the molecular mechanisms of VPA-induced hepatic steatosis using FL83B cell line-based in vitro model. Using fluorescent lipid staining technique, we found that VPA enhanced oleic acid- (OLA-) induced lipid accumulation in a dose-dependent manner in hepatocytes; this may be due to upregulated lipid uptake, triacylglycerol (TAG) synthesis, and lipid droplet formation. Real-time PCR results showed that, following VPA treatment, the expression levels of genes encoding cluster of differentiation 36 (Cd36), low-density lipoprotein receptor-related protein 1 (Lrp1), diacylglycerol acyltransferase 2 (Dgat2), and perilipin 2 (Plin2) were increased, that of carnitine palmitoyltransferase I a (Cpt1a) was not affected, and those of acetyl-Co A carboxylase α (Acca) and fatty acid synthase (Fasn) were decreased. Furthermore, using immunofluorescence staining and flow cytometry analyses, we found that VPA also induced peroxisome proliferator-activated receptor γ (PPARγ) nuclear translocation and increased levels of cell-surface CD36. Based on these results, we propose that VPA may enhance OLA-induced hepatocyte steatosis through the upregulation of PPARγ- and CD36-dependent lipid uptake, TAG synthesis, and lipid droplet formation.

A novel truncated form of apolipoprotein A-I transported by dense LDL is increased in diabetic patients.

Diabetic (DM) patients have exacerbated atherosclerosis and high CVD burden. Changes in lipid metabolism, lipoprotein structure, and dysfunctional HDL are characteristics of diabetes. Our aim was to investigate whether serum ApoA-I, the main protein in HDL, was biochemically modified in DM patients. By using proteomic technologies, we have identified a 26 kDa ApoA-I form in serum. MS analysis revealed this 26 kDa form as a novel truncated variant lacking amino acids 1-38, ApoA-IΔ(1-38). DM patients show a 2-fold increase in ApoA-IΔ(1-38) over nondiabetic individuals. ApoA-IΔ(1-38) is found in LDL, but not in VLDL or HDL, with an increase in LDL3 and LDL4 subfractions. To identify candidate mechanisms of ApoA-I truncation, we investigated potentially involved enzymes by in silico data mining, and tested the most probable molecule in an established animal model of diabetes. We have found increased hepatic cathepsin D activity as one of the potential proteases involved in ApoA-I truncation. Cathepsin D-cleaved ApoA-I exhibited increased LDL binding affinity and decreased antioxidant activity against LDL oxidation. In conclusion, we show for the first time: a) presence of a novel truncated ApoA-I form, ApoA-IΔ(1-38), in human serum; b) ApoA-IΔ(1-38) is transported by LDL; c) ApoA-IΔ(1-38) is increased in dense LDL fractions of DM patients; and d) cathepsin D-ApoA-I truncation may lead to ApoA-IΔ(1-38) binding to LDLs, increasing their susceptibility to oxidation and contributing to the high cardiovascular risk of DM patients.

Correlation between salivary and serum oxidized LDL levels: a pilot study on overweight/obese subjects.

BACKGROUND: Saliva contains a variety of substances and could be functionally equivalent to serum in reflecting the physiological state of the body, including metabolic variations. Salivary samples are non-invasive, safe, and easier to handle than serum. Oxidized LDL cholesterol (oxLDL) is an additional cardiovascular risk factor playing an important role in atheromatous plaque formation; overweight/obese subjects present an increase in oxLDL concentrations. The aims of the study were to assess oxLDL salivary levels, if detectable, and to verify their possible correlation with serum in overweight/obese subjects. METHODS: Thirty-five consecutive overweight/obese subjects and 10 normal weight controls were enrolled. Serum and salivary oxLDL levels were measured by a commercial enzyme-linked-immunosorbent assay (ELISA method). RESULTS: oxLDL levels were detectable in salivary samples and correlated (P = 0.001) with serum levels. Overweight/obese subjects showed serum and salivary oxLDL levels higher than controls (P = 0.000 and P = 0.022, respectively). CONCLUSIONS: Our study showed the presence of oxLDL in salivary samples and highlighted a correlation between salivary oxLDL levels and their counterpart in serum. Moreover, salivary oxLDL levels were higher in overweight/obese subjects than in controls. Therefore, a salivary sample could be functionally equivalent to serum in monitoring cardiovascular risk in overweight/obese subjects.

Purple perilla extracts allay ER stress in lipid-laden macrophages.

There is a growing body of evidence that excess lipids, hypoxic stress and other inflammatory signals can stimulate endoplasmic reticulum (ER) stress in metabolic diseases. However, the pathophysiological importance and the underlying mechanisms of this phenomenon remain unknown. The current study investigated that 50 ng/ml oxidized LDL promoted unfolded protein response (UPR) and ER stress in J774A1 murine macrophages, which was blocked by extracts (PPE) of purple Perilla frutescens, a plant of the mint family Lamiaceae. The ER stressor tunicamycin was employed as a positive control. Treating 1-10 µg/ml oxidized LDL for 24 h elicited lipotoxic apoptosis in macrophages with obvious nuclear condensation and DNA fragmentation, which was inhibited by PPE. Tunicamycin and oxidized LDL activated and induced the UPR components of activating transcription factor 6 and ER resident chaperone BiP/Grp78 in temporal manners and such effects were blocked by ≥5 µg/ml PPE. In addition, PPE suppressed the enhanced mRNA transcription and splicing of X-box binding protein 1 (XBP1) by tunicamycin and oxidized LDL. The protein induction and nuclear translocation of XBP1 were deterred in PPE-treated macrophages under ER stress. The induction of ATP-binding cassette transporter A1 (ABCA1), scavenger receptor-B1 (SR-B1) and intracellular adhesion molecule-1 (ICAM-1) was abolished by the ER stressor in activated macrophages. The protein induction of ABCA1 and ICAM1 but not SR-B1 was retrieved by adding 10 µg/ml PPE to cells. These results demonstrate that PPE inhibited lipotoxic apoptosis and demoted the induction and activation of UPR components in macrophages. PPE restored normal proteostasis in activated macrophages oxidized LDL. Therefore, PPE was a potent agent antagonizing macrophage ER stress due to lipotoxic signals associated with atherosclerosis.

Gender disparity in LDL-induced cardiovascular damage and the protective role of estrogens against electronegative LDL.

BACKGROUND: Increased levels of the most electronegative type of LDL, L5, have been observed in the plasma of patients with metabolic syndrome (MetS) and ST-segment elevation myocardial infarction and can induce endothelial dysfunction. Because men have a higher predisposition to developing coronary artery disease than do premenopausal women, we hypothesized that LDL electronegativity is increased in men and promotes endothelial damage. METHODS: L5 levels were compared between middle-aged men and age-matched, premenopausal women with or without MetS. We further studied the effects of gender-influenced LDL electronegativity on aortic cellular senescence and DNA damage in leptin receptor-deficient (db/db) mice by using senescence-associated-ß-galactosidase and γH2AX staining, respectively. We also studied the protective effects of 17ß-estradiol and genistein against electronegative LDL-induced senescence in cultured bovine aortic endothelial cells (BAECs). RESULTS: L5 levels were higher in MetS patients than in healthy subjects (P < 0.001), particularly in men (P = 0.001). LDL isolated from male db/db mice was more electronegative than that from male or female wild-type mice. In addition, LDL from male db/db mice contained abundantly more apolipoprotein CIII and induced more BAEC senescence than did female db/db or wild-type LDL. In the aortas of db/db mice but not wild-type mice, we observed cellular senescence and DNA damage, and the effect was more significant in male than in female db/db mice. Pretreatment with 17ß-estradiol or genistein inhibited BAEC senescence induced by male or female db/db LDL and downregulated the expression of lectin-like oxidized LDL receptor-1 and tumor necrosis factor-alpha protein. CONCLUSION: The gender dichotomy of LDL-induced cardiovascular damage may underlie the increased propensity to coronary artery disease in men.

Carbamylation of LDL and its relationship with myeloperoxidase in type 2 diabetes mellitus.

LDL (low-density lipoprotein) is subjected to pro-atherogenic modifications in the circulation. A novel uraemia-independent mechanism of carbamylation of lipoproteins mediated by MPO (myeloperoxidase) has recently been reported. We have investigated whether carbamylation of LDL was increased in patients with Type 2 diabetes without renal impairment and the role of MPO. cLDL (carbamylated LDL) and MPO were measured by ELISA in a cross-sectional study of 198 patients and 174 non-diabetic controls. The impact of lowering MPO on plasma cLDL was determined by assaying cLDL and MPO in archived samples from a previous randomized open-label parallel group study comparing rosiglitazone (n=20) and sulfonylurea (n=24). Both plasma cLDL (P<0.05) and MPO levels (P<0.01) were higher in patients with Type 2 diabetes than controls in the cross-sectional study. Plasma cLDL correlated with MPO (r=0.42 and P<0.01) in subjects with diabetes, and plasma MPO was an independent determinant of plasma cLDL even after adjusting for age, gender, BMI (body mass index), apoB (apolipoprotein B), urea and HbA1c (glycated haemoglobin). In the randomized trial, rosiglitazone significantly lowered MPO (P<0.01) and cLDL (P<0.05), whereas no changes were observed in the sulfonylurea group despite a similar reduction in HbA1c. The magnitude of reduction in plasma cLDL correlated with changes in MPO, but not with HbA1c in the rosiglitazone group, suggesting that lowering MPO reduced plasma cLDL. Plasma cLDL is increased in patients with Type 2 diabetes even in the absence of renal impairment and carbamylation of LDL in these subjects is mainly mediated by MPO and not by urea.

[Medicinal chemistry and pharmacology focused on cannabidiol, a major component of the fiber-type cannabis].

Considerable attention has focused on cannabidiol (CBD), a major non-psychotropic constituent of fiber-type cannabis plant, and it has been reported to possess diverse biological activities. Although CBD is obtained from non-enzymatic decarboxylation of its parent molecule, cannabidiolic acid (CBDA), several studies have investigated whether CBDA itself is biologically active. In the present report, the author summarizes findings indicating that; 1) CBDA is a selective cyclooxygenase-2 (COX-2) inhibitor, and ii) CBDA possesses an anti-migrative potential for highly invasive cancer cells, apparently through a mechanism involving inhibition of cAMP-dependent protein kinase A, coupled with an activation of the small GTPase, RhoA. Further, the author introduces recent findings on the medicinal chemistry and pharmacology of the CBD derivative, CBD-2',6'-dimethyl ether (CBDD), that exhibits inhibitory activity toward 15-lipoxygenase (15-LOX), an enzyme responsible for the production of oxidized low-density lipoprotein (LDL). These studies establish CBD as both an important experimental tool and as a lead compound for pharmaceutical development. In this review, the author further discusses the potential uses of CBD and its derivatives in future medicines.

Role of proinflammatory factors, nitric oxide, and some parameters of lipid metabolism in the development of immediate adaptation to hypoxia and HIF-1α accumulation.

The development of immediate and delayed long-term resistance to hypoxia during a course of intermittent normobaric hypoxia (15 daily sessions of alternating exposure to 10% O2 and atmospheric air for 1 h) correlated with biphasic expression of HIF-1α in neocortex of hypoxia-intolerant rats, which suggests involvement of this protein factor not only in the formation of long-term adaptation, but also in triggering immediate adaptation to hypoxia. Both processes develop under conditions promoting down-regulation of oxidative modification of LDL and increasing tolerance of biological membranes to hypoxia in the absence of activation of the free radical processes, which therefore do not trigger HIF-1α expression under these conditions. Neither cytokines nor NO are the inducers of immediate adaptation, and they are not related to HIF-1α expression during the early post-hypoxic period. In contrast, long-term adaptation in response to the course of intermittent normobaric hypoxia develops against the background of enhanced NO production, activation of pro- and anti-inflammatory factors, and expression of VEGF, the marker of angiogenesis. Therefore, all these factors can promote activation of transcription processes required to form the long-term adaptation.

Oxidized LDL level is related to gene expression of tumour necrosis factor super family members in children and young adults with familial hypercholesterolaemia.

OBJECTIVE: Familial hypercholesterolaemia (FH) is associated with increased risk of premature atherosclerosis. Inflammation is a key event in atherogenesis, and we have previously reported an inflammatory imbalance between tumour necrosis factor (TNF)α and interleukin-10 in children with FH. Based on the potential role of TNF-related molecules in inflammation, we investigated the regulation of other members of the TNF superfamily (TNFSF)/TNF receptor superfamily (TNFRSF) in children and young adults with FH and matched healthy controls. METHODS: Expression of TNFSF/TNFRSF genes in peripheral blood mononuclear cells (PBMCs) was quantified in children and young adults with FH prior to (n = 42) and after statin treatment (n = 10) and in controls (n = 25) by quantitative real-time polymerase chain reaction. RESULTS: First we found that, compared with controls, the mRNA levels of OX40L, BAFFR and TRAILR1 were significantly higher, whereas TRAIL and TRAILR3 were significantly lower in children and young adults with FH. Secondly, levels of oxidized low-density lipoprotein (oxLDL) were significantly raised in the FH group, and correlated with the expression of OX40L, BAFFR and TRAILR1. Thirdly, oxLDL increased mRNA levels of BAFFR, TRAILR1 and TRAILR4 in PBMCs ex vivo from individuals with FH. Fourthly, OX40, acting through OX40L, enhanced the oxLDL-induced expression of matrix metalloproteinase-9 in THP-1 monocytes in vitro. Finally, after statin treatment in children with FH (n = 10), mRNA levels of OX40L and TRAILR1 decreased, whereas levels BAFF, TRAIL and TRAILR3 increased. CONCLUSION: Our findings suggest the involvement of some TNFSF/TNFRSF members and oxLDL in the early stages of atherogenesis; this may potentially contribute to the accelerated rate of atherosclerosis observed in individuals with FH.

Androgen deprivation by flutamide modulates uPAR, MMP-9 expressions, lipid profile, and oxidative stress: amelioration by daidzein.

The growth and development of prostate gland is governed by testosterone. Testosterone helps in maintaining the adipose tissue stores of the body. It is well documented that with advancing age there has been a gradual decline in testosterone levels. Our aim was to study the protective role of daidzein on flutamide-induced androgen deprivation on matrix degrading genes, lipid profile and oxidative stress in Wistar rats. Sub-chronic (60 days) flutamide (30 mg/kg b.wt) administration resulted in marked increase in expressions of matrix degrading genes [matrix metalloproteases 9 and urokinase plasminogen activation receptor]. Additionally, it increased the levels of low density lipoproteins, total cholesterol, triglycerides, and lowered the levels of high density lipoproteins and endogenous antioxidant levels. Oral administration of daidzein (20 and 60 mg/kg b.wt) restituted the levels to normal. Daidzein administration resulted in amelioration of the prostate atrophy, degeneracy and invasiveness induced by flutamide. Our findings suggest that the daidzein may be given as dietary supplement to patients who are on androgen deprivation therapy, to minimize the adverse effects related to it and also retarding susceptibility of patients to cardiovascular diseases.

Blockade of IL-6 and TNF-α inhibited oxLDL-induced production of MCP-1 via scavenger receptor induction.

In chronic inflammatory diseases, cardiovascular disease risk is increased and is the main cause of increased mortality. Oxidized LDL (oxLDL) and scavenger receptors participate in atherogenesis. Using human arterial endothelial cells (HAECs), we evaluated the effect of IL-6 and TNF-α on the expression of scavenger receptors. IL-6 induced expression of SR-A mRNA and TNF-α induced both SR-A and LOX-1 mRNA. Both did induce either CD36 or CD68. To assess the function of scavenger receptors, MCP-1 production by oxLDL from cytokine-pretreated HAEC was examined. In accordance with scavenger receptor expression, oxLDL-induced MCP-1 production was increased in IL-6- or TNF-α-pretreatment. Serum from rheumatoid arthritis patients but not from healthy subjects increased mRNA expressions of SR-A, LOX-1 and CD36 in HAEC. SR-A expression was inhibited by both anti-IL-6 receptor antibody (α-IL-6R Ab) and TNF-α receptor (p75)-Fc (TNFR-Fc) and LOX-1 expression was inhibited by TNFR-Fc. CD36 expression was affected by neither. Serum from rheumatoid arthritis patients augmented oxLDL-induced MCP-1 production. Both α-IL-6R Ab and TNFR-Fc partially inhibited this MCP-1 production. In conclusion, our results strongly support that blocking therapy of IL-6 and TNF-α might be beneficial to reduce atherosclerosis risk in chronic inflammatory diseases.

Anti-oxidized low-density lipoprotein (oxLDL) antibody levels are not related to increasing circulating oxLDL concentrations during the course of pregnancy.

PROBLEM: To address the question of whether the high levels of oxidative modified low-density lipoproteins (oxLDL) in pregnancy are opposed by an appropriate humoral autoimmune response providing anti-oxLDL autoantibodies in maternal serum of healthy women throughout gestation. METHOD OF STUDY: Blood was taken from 33 patients at four different time points from early to late gestation and post-partum. OxLDL and anti-oxLDL concentrations were measured by enzyme-linked immunosorbent assays. ANOVA was used for statistical evaluations followed by post hoc test with Bonferoni adjustment. RESULTS: Oxidized Low Density Lipoprotein concentrations increased while anti-oxLDL levels decreased significantly from early to late gestation. OxLDL was strongly positively correlated with LDL concentration and mildly negatively associated with anti-oxLDL levels. Estimating the status of oxidation by calculating oxLDL/LDL ratio revealed decreasing values with ongoing pregnancy. Multivariate analysis showed that anti-oxLDL levels were dependent on gestational age but neither on oxLDL levels nor on the oxLDL/LDL ratio. CONCLUSIONS: The results indicate that normal pregnancy is a well-balanced state of oxidative and anti-oxidative processes. However, we could not confirm a dependence of anti-oxLDL autoantibodies on oxLDL concentration. Whether or not the humoral immune system is involved in oxidative defence remains to be elucidated.

Cannabidiol-2',6'-dimethyl ether as an effective protector of 15-lipoxygenase-mediated low-density lipoprotein oxidation in vitro.

15-Lipoxygenase (15-LOX) is one of the key enzymes responsible for the formation of oxidized low-density lipoprotein (ox-LDL), a major causal factor for atherosclerosis. Both enzymatic (15-LOX) and non-enzymatic (Cu(2+)) mechanisms have been proposed for the production of ox-LDL. We have recently reported that cannabidiol-2',6'-dimethyl ether (CBDD) is a selective and potent inhibitor of 15-LOX-catalyzed linoleic acid oxygenation (Takeda et al., Drug Metab. Dispos., 37, 1733-1737 (2009)). In the LDL, linoleic acid is present as cholesteryl linoleate, the major fatty acid esterified to cholesterol, and is susceptible to oxidative modification by 15-LOX or Cu(2+). In this investigation, we examined the efficacy of CBDD on i) 15-LOX-catalyzed oxygenation of cholesteryl linoleate, and ii) ox-LDL formation catalyzed by 15-LOX versus Cu(2+)-mediated non-enzymatic generation of this important mediator. The results obtained demonstrate that CBDD is a potent and selective inhibitor of ox-LDL formation generated by the 15-LOX pathway. These studies establish CBDD as both an important experimental tool for characterizing 15-LOX-mediated ox-LDL formation, and as a potentially useful therapeutic agent for treatment of atherosclerosis.

The influence of dosing time, variable compliance and circadian low-density lipoprotein production on the effect of simvastatin: simulations from a pharmacokinetic-pharmacodynamic model.

The aim of this study was to explore the influence of simvastatin dosing time, variable compliance and circadian cholesterol production on the reduction of low-density lipoprotein (LDL). A published pharmacokinetic-pharmacodynamic (PKPD) model for simvastatin was identified and evaluated. A model for circadian LDL production was incorporated into the PKPD model. Reduction in LDL from baseline was simulated stochastically from the full model at dose levels of 10, 20, 40 and 80 mg daily for 30 days. Simulated dosing times for each data set were morning (8.00 a.m.), evening (22.00 p.m.), evening with reduced compliance and evening for a hypothetical bioequivalent generic. Differences in LDL reduction from baseline between evening (33-43%) and morning dosing (31-43%) were negligible across a range of doses. Any differences were negated when variable compliance was considered. In addition, differences in simvastatin effect between morning and evening dosing were found to be within the range of LDL concentrations that would be permissible for a bioequivalent generic (at the lower limit) and hence are not likely to be important clinically. The results of this study suggest that taking simvastatin in the evening is not superior to morning dosing.

Tissue expression of glycated apolipoprotein B in colorectal adenoma and cancer.

BACKGROUND: Myocardial infarction and colorectal cancer are associated at the population level and in autoptic studies. Glycated apolipoprotein B (apoB) is a risk factor for the development of myocardial infarction. The association of glycated apoB with dysplastic and neoplastic colorectal tissue was investigated. MATERIALS AND METHODS: Forty-eight consecutive surgical specimens, 26 colorectal adenomas and 22 colorectal carcinomas, retrieved from the archives of the Pathologic Anatomy Department of our institution, were examined. The tissue content of glycated apoB was determined using a monoclonal antibody. RESULTS: Glycated apoB was detected in 27% of the adenomas and 45% of the cancer tissue, but only in 18% of the normal tissue near the cancer site. CONCLUSION: Glycated apoB is associated with dysplastic and even more so with neoplastic cancer tissue.