Trans-10, cis-12-conjugated linoleic acid (CLA)-enriched diets promote fatty liver in mice, while cis-9, trans-11-CLA ameliorates this effect, suggesting regulation of multiple genes. To test this hypothesis, apoE-deficient mice were fed a Western-type diet enriched with linoleic acid isomers, and their hepatic gene expression was analyzed with DNA microarrays. To provide an initial screening of candidate genes, only 12 with remarkably modified expression between both CLA isomers were considered and confirmed by quantitative RT-PCR. Additionally mRNA expression of 15 genes involved in lipid metabolism was also studied. Ten genes (Fsp27, Aqp4, Cd36, Ly6d, Scd1, Hsd3b5, Syt1, Cyp7b1, and Tff3) showed significant associations among their expressions and the degree of hepatic steatosis. Their involvement was also analyzed in other models of steatosis. In hyperhomocysteinemic mice lacking Cbs gene, only Fsp27, Cd36, Scd1, Syt1, and Hsd3b5 hepatic expressions were associated with steatosis. In apoE-deficient mice consuming olive-enriched diet displaying reduction of the fatty liver, only Fsp27 and Syt1 expressions were found associated. Using this strategy, we have shown that expression of these genes is highly associated with hepatic steatosis in a genetic disease such as Cbs deficiency and in two common situations such as Western diets containing CLA isomers or a Mediterranean-type diet. Conclusion: The results highlight new processes involved in lipid handling in liver and will help to understand the complex human pathology providing new proteins and new strategies to cope with hepatic steatosis.

As olive oil is the main source of calories in the Mediterranean diet, a great deal of research has been devoted to characterizing its role in atherosclerosis. Virgin olive oil is an oily matrix that contains hydrocarbons, mainly squalene; triterpenes such as uvaol, erythrodiol, oleanolic, and maslinic acid; phytosterols; and a wide range of phenolic compounds comprising simple phenols, flavonoids, secoiridoids, and lignans. In this review, we analyze the studies dealing with atherosclerosis and olive oil in several species. A protective role of virgin olive oil against atherosclerosis has been shown in ApoE‐deficient mice and hamsters. In the former animal, sex, dose, and dietary cholesterol are modulators of the outcome. Contradictory findings have been reported for rabbits, a circumstance that could be due to the profusion of experimental designs, differing in terms of doses and animal strains, as well as sources of olive oils. This role has yet to be fully validated in humans. Minor components of olive oil have been shown to be involved in atherosclerosis protection. Nevertheless, evidence of the potential of isolated compounds or the right combination of them to achieve the antiatherosclerotic effect of virgin olive oil is inconclusive and will undoubtedly require further experimental support.

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Conjugated linoleic acids (CLA) affect atherogenesis, but mechanisms are not well understood. We explored how two isomers of CLA, cis9, trans11-CLA and trans10, cis12-CLA, affected lipid and glucose metabolism, as well as hepatic protein expression, in apolipoprotein E knockout mice. After 12 wk of intervention, plasma triglyceride, NEFA, and glucose concentrations were significantly higher in the trans10, cis12-CLA group, whereas plasma triglyceride, NEFA, glucose, and insulin concentrations were significantly lower in the cis9, trans11-CLA group, compared with control mice consuming linoleic acid. Proteomics identified significant up- or down-regulation of 113 liver cytosolic proteins by either CLA isomer. Principal component analysis revealed that the treatment effect of cis9, trans11-CLA was mainly explained by the up-regulation of different posttranslational forms of heat shock protein 70 kD. In contrast, the treatment effect of trans10, cis12-CLA was mainly explained by up-regulation of key enzymes in the gluconeogenic, beta-oxidation, and ketogenesic pathways. Correlation analysis again emphasized the divergent effects of both CLA isomers on different pathways, but also revealed a linkage between insulin resistance and increased levels of hepatic serotransferrin. Thus, our systems biology approach provided novel insights into the mechanisms by which individual CLA isomers differentially affect pathways related to atherogenesis, such as insulin resistance and inflammation.

We have previously shown that NOR-1 (NR4A3) modulates the proliferation and survival of vascular cells in culture. However, in genetically modified animal models, somewhat conflicting results have been reported concerning the involvement of NOR-1 in neointimal formation after vascular injury. The aim of this study was to generate a transgenic mouse model over-expressing NOR-1 in smooth muscle cells (SMCs) and assess the consequence of a gain of function of this receptor on intimal hyperplasia after vascular injury. The transgene construct (SM22-NOR1) was prepared by ligating the full-length human NOR-1 cDNA (hNOR-1) and a mouse SM22α minimal promoter able to drive NOR-1 expression to SMC. Two founders were generated and two stable transgenic mouse lines (TgNOR-1) were established by backcrossing the transgene-carrying founders with C57BL/6J mice. Real-time PCR and immunohistochemistry confirmed that hNOR-1 was mainly targeted to vascular beds such as aorta and carotid arteries, and was similar in both transgenic lines. Vascular SMC from transgenic animals exhibit increased NOR-1 transcriptional activity (assessed by electrophoretic mobility shift assay and luciferase assays), increased mitogenic activity (determined by [(3)H]-thymidine incorporation; 1.58-fold induction, P < 0.001) and increased expression of embryonic smooth muscle myosin heavy chain (SMemb) than wild-type cells from control littermates. Using the carotid artery ligation model, we show that neointima formation was increased in transgenic versus wild-type mice (2.36-fold induction, P < 0.01). Our in vivo data support a role for NOR-1 in VSMC proliferation and vascular remodelling. This NOR-1 transgenic mouse could be a useful model to study fibroproliferative vascular diseases.

Background and PurposeSqualene, the main hydrocarbon in the unsaponifiable fraction of virgin olive oil, is involved in cholesterol synthesis and it has been reported to own antiatherosclerotic and antiesteatosic effects. However, the squalene's role on lipid plasma parameters and the influence of genotype on this effect need to be addressed.Experimental ApproachesThree male mouse models (wild-type, Apoa1- and Apoe- deficient) were fed chow semisynthetic diets enriched in squalene to provide a dose of 1 g/kg during 11 weeks. After this period, their plasma parameters and lipoprotein profiles were analyzed.Key ResultsSqualene administration at a dose of 1 g/kg showed decreased reactive oxygen species in lipoprotein fractions independently of the animal background and caused an specific increase in high density lipoprotein (HDL)-cholesterol levels, accompanied by an increase in phosphatidylcholine and paraoxonase 1 and no changes in apolipoproteins A1 and A4 in wild-type mice. In these mice, the cholesterol increase was due to its esterified form and associated with an increased hepatic expression of Lcat. These effects were not observed in absence of apolipoprotein A1. The increases in HDL- paraoxonase 1 were translated into decreased plasma malondialdehyde levels depending on the presence of Apolipoprotein A1.Conclusions and ImplicationsDietary squalene promotes changes in HDL- cholesterol and paraoxonase 1 and decreases reactive oxygen species in lipoproteins and plasma malondialdehyde levels, providing new benefits of its intake that might contribute to explain the properties of virgin olive oil, although the phenotype related to apolipoproteins A1 and E may be particularly relevant.

:  Melatonin has antiproliferative properties in prostate cancer cells. Melatonin reduces proliferation without increasing apoptosis, and it promotes cell differentiation into a neuroendocrine phenotype. Because neuroendocrine cells displayed an androgen‐independent growth and high resistance to radiotherapy and chemotherapy, the role of molecules that induce neuroendocrine differentiation was questioned in terms of their usefulness as oncostatic agents. By using human epithelial androgen‐dependent and androgen‐independent prostate cancer cells, the role of melatonin in drug‐induced apoptosis was studied after acute treatments. In addition to cytokines such as hrTNF‐alpha and TRAIL, chemotherapeutic compounds, including doxorubicin, docetaxel, or etoposide, were employed in combination with melatonin to promote cell death. Melatonin promotes cell toxicity caused by cytokines without influencing the actions of chemotherapeutic agents. In addition, antioxidant properties of melatonin were confirmed in prostate cancer cells. However, its ability to increase cell death caused by cytokines was independent of the redox changes. Finally, phenotypic changes caused by chronic treatment with the indole, that is, neuroendocrine differentiation, make cells significantly more sensitive to cytokines and slightly more sensitive to some chemotherapeutic compounds. Thus, melatonin is a good inhibitor of the proliferation of prostate cancer cells, promoting phenotypic changes that do not increase survival mechanisms and make cells more sensitive to cytokines such as TNF‐alpha or TRAIL.