Thioredoxin Domain Containing 5 (TXNDC5): Friend or Foe?

This review focuses on the thioredoxin domain containing 5 (TXNDC5), also known as endoplasmic reticulum protein 46 (ERp46), a member of the protein disulfide isomerase (PDI) family with a dual role in multiple diseases. TXNDC5 is highly expressed in endothelial cells, fibroblasts, pancreatic ß-cells, liver cells, and hypoxic tissues, such as cancer endothelial cells and atherosclerotic plaques. TXNDC5 plays a crucial role in regulating cell proliferation, apoptosis, migration, and antioxidative stress. Its potential significance in cancer warrants further investigation, given the altered and highly adaptable metabolism of tumor cells. It has been reported that both high and low levels of TXNDC5 expression are associated with multiple diseases, such as arthritis, cancer, diabetes, brain diseases, and infections, as well as worse prognoses. TXNDC5 has been attributed to both oncogenic and tumor-suppressive features. It has been concluded that in cancer, TXNDC5 acts as a foe and responds to metabolic and cellular stress signals to promote the survival of tumor cells against apoptosis. Conversely, in normal cells, TXNDC5 acts as a friend to safeguard cells against oxidative and endoplasmic reticulum stress. Therefore, TXNDC5 could serve as a viable biomarker or even a potential pharmacological target.

Thioredoxin domain containing 5 is involved in the hepatic storage of squalene into lipid droplets in a sex-specific way.

Hepatic thioredoxin domain-containing 5 (TXNDC5) is a member of the protein disulfide isomerase family found associated with anti-steatotic properties of squalene and located in the endoplasmic reticulum and in lipid droplets. Considering that the latter are involved in hepatic squalene accumulation, the present research was aimed to investigate the role of TXNDC5 on hepatic squalene management in mice and in the AML12 hepatic cell line. Wild-type and TXNDC5-deficient (KO) mice were fed Western diets with or without 1% squalene supplementation for 6 weeks. In males, but not in females, absence of TXNDC5 blocked hepatic, but not duodenal, squalene accumulation. Hepatic lipid droplets were isolated and characterized using label-free LC-MS/MS analysis. TXNDC5 accumulated in this subcellular compartment of mice receiving squalene and was absent in TXNDC5-KO male mice. The latter mice were unable to store squalene in lipid droplets. CALR and APMAP were some of the proteins that responded to the squalene administration in all studied conditions. CALR and APMAP were positively associated with lipid droplets in the presence of squalene and they were decreased by the absence of TXNDC5. The increased squalene content was reproduced in vitro using AML12 cells incubated with squalene-loaded nanoparticles and this effect was not observed in an engineered cell line lacking TXNDC5. The phenomenon was also present when incubated in the presence of a squalene epoxidase inhibitor, suggesting a mechanism of squalene exocytosis involving CALR and APMAP. In conclusion, squalene accumulation in hepatic lipid droplets is sex-dependent on TXNDC5 that blocks its secretion.

Endoplasmic Reticulum Protein TXNDC5 Interacts with PRDX6 and HSPA9 to Regulate Glutathione Metabolism and Lipid Peroxidation in the Hepatic AML12 Cell Line.

Non-alcoholic fatty liver disease or steatosis is an accumulation of fat in the liver. Increased amounts of non-esterified fatty acids, calcium deficiency, or insulin resistance may disturb endoplasmic reticulum (ER) homeostasis, which leads to the abnormal accumulation of misfolded proteins, activating the unfolded protein response. The ER is the primary location site for chaperones like thioredoxin domain-containing 5 (TXNDC5). Glutathione participates in cellular oxidative stress, and its interaction with TXNDC5 in the ER may decrease the disulfide bonds of this protein. In addition, glutathione is utilized by glutathione peroxidases to inactivate oxidized lipids. To characterize proteins interacting with TXNDC5, immunoprecipitation and liquid chromatography-mass spectrometry were used. Lipid peroxidation, reduced glutathione, inducible phospholipase A2 (iPLA2) and hepatic transcriptome were assessed in the AML12 and TXNDC5-deficient AML12 cell lines. The results showed that HSPA9 and PRDX6 interact with TXNDC5 in AML12 cells. In addition, TXNDC5 deficiency reduced the protein levels of PRDX6 and HSPA9 in AML12. Moreover, lipid peroxidation, glutathione and iPLA2 activities were significantly decreased in TXNDC5-deficient cells, and to find the cause of the PRDX6 protein reduction, proteasome suppression revealed no considerable effect on it. Finally, hepatic transcripts connected to PRDX6 and HSPA9 indicated an increase in the Dnaja3, Mfn2 and Prdx5 and a decrease in Npm1, Oplah, Gstp3, Gstm6, Gstt1, Serpina1a, Serpina1b, Serpina3m, Hsp90aa1 and Rps14 mRNA levels in AML12 KO cells. In conclusion, the lipid peroxidation system and glutathione mechanism in AML12 cells may be disrupted by the absence of TXNDC5, a novel protein-protein interacting partner of PRDX6 and HSPA9.

Pulsed electric field increases the extraction yield of extra virgin olive oil without loss of its biological properties.

Introduction: Pulsed electric field (PEF) has been used for improving extraction of extra virgin olive oil (EVOO). However, the biological changes induced by the consumption of pulsed electric field-obtained extra virgin olive oil (PEFEVOO) have not been studied yet. Materials and methods: EVOO oils from Empeltre variety were prepared by standard (STD) cold pressure method involving crushing of the olives, malaxation and decanting and by this procedure including an additional step of PEF treatment. Chemical analyses of EVOO oils were done. Male and female Apoe-deficient mice received diets differing in both EVOOs for 12 weeks, and their plasma, aortas and livers were analyzed. Results: PEF application resulted in a 17% increase in the oil yield and minimal changes in chemical composition regarding phytosterols, phenolic compounds and microRNA. Only in females mice consuming PEF EVOO, a decreased plasma total cholesterol was observed, without significant changes in atherosclerosis and liver steatosis. Conclusion: PEF technology applied to EVOO extraction maintains the EVOO quality and improves the oil yield. The equivalent biological effects in atherosclerosis and fatty liver disease of PEF-obtained EVOO further support its safe use as a food.

Dietary Squalene Induces Cytochromes Cyp2b10 and Cyp2c55 Independently of Sex, Dose, and Diet in Several Mouse Models.

SCOPE: To investigate the effects of squalene, the main hydrocarbon present in extra virgin olive oil, on liver transcriptome in different animal models and to test the influence of sex on this action and its relationship with hepatic lipids. METHODS AND RESULTS: To this purpose, male C57BL/6J Apoe-deficient mice are fed a purified Western diet with or without squalene during 11 weeks and hepatic squalene content is assessed, so are hepatic lipids and lipid droplets. Hepatic transcriptomic changes are studied and confirmed by RT-qPCR. Dietary characteristics and influence of squalene doses are tested in Apoe-deficient on purified chow diets with or without squalene. These diets are also given to Apoa1 and wild-type mice on C57BL/6J background and to C57BL/6J xOla129 Apoe-deficient mice. Squalene supplementation increases its hepatic content without differences among sexes and hormonal status. The Cyp2b10 and Cyp2c55 gene expressions are significantly up-regulated by the squalene intake in all models, with independence of sex, sexual hormones, dietary fat content, genetic background and dose, and in Apoe-deficient mice consuming extra-virgin olive oil. CONCLUSION: Hepatic squalene increases the expression of these cytochromes and their changes in virgin olive oil diets may be due to their squalene content.

Hepatic Synaptotagmin 1 is involved in the remodelling of liver plasma- membrane lipid composition and gene expression in male Apoe-deficient mice consuming a Western diet.

BACKGROUND AND AIMS: The molecular mechanisms by which the liver develops steatotic disease still remain unclear. Previous studies using nutritional and genetic models of hepatic steatosis in mice showed that liver synaptotagmin 1 (Syt1) expression was associated with lipid droplet area. Hepatic Syt1 overexpression was used as a tool to explore its effect on hepatic and plasma lipids. METHODS AND RESULTS: To find out a cause-effect, hepatic mouse Syt1 mRNA was cloned into a vector driving hepatocyte-specific expression and administered by hydrodynamic injection to male Apoe-deficient mice fed on a Western diet, the latter as a model of rapid spontaneous steatosis development. Hepatic microsomal, large vesicle, lysosomal and plasma membrane fractions were enriched in SYT1 protein following gene overexpression. In these conditions, very low density lipoprotein esterified cholesterol increased. Likewise, the transgene caused an alteration in lipid droplet surface and a positive correlation between Syt1 expression and hepatic total cholesterol content. A lipidomic approach evidenced a decrease in lysophosphatidylcholine, phosphatidylcholine and triglycerides in isolated plasma membrane fraction. Expressions of genes involved in biosynthesis of bile acids, fatty acid metabolism, lipoprotein dynamics and vesicular transport were modified by the increased SYT1 expression. CONCLUSIONS: These results indicate that this protein is involved in hepatic management of lipids and in the regulation of genes involved in lipid metabolism.

Pgc1a is responsible for the sex differences in hepatic Cidec/Fsp27ß mRNA expression in hepatic steatosis of mice fed a Western diet.

Hepatic fat-specific protein 27 [cell death-inducing DNA fragmentation effector protein C (Cidec)/Fsp27] mRNA levels have been associated with hepatic lipid droplet extent under certain circumstances. To address its hepatic expression under different dietary conditions and in both sexes, apolipoprotein E (Apoe)-deficient mice were subjected to different experimental conditions for 11 wk to test the influence of cholesterol, Western diet, squalene, oleanolic acid, sex, and surgical castration on Cidec/Fsp27 mRNA expression. Dietary cholesterol increased hepatic Cidec/Fsp27ß expression, an effect that was suppressed when cholesterol was combined with saturated fat as represented by Western diet feeding. Using the latter diet, neither oleanolic acid nor squalene modified its expression. Females showed lower levels of hepatic Cidec/Fsp27ß expression than males when they were fed Western diets, a result that was translated into a lesser amount of CIDEC/FSP27 protein in lipid droplets and microsomes. This was also confirmed in low-density lipoprotein receptor (Ldlr)-deficient mice. Incubation with estradiol resulted in decreased Cidec/Fsp27ß expression in AML12 cells. Whereas male surgical castration did not modify the expression, ovariectomized females did show increased levels compared with control females. Females also showed increased expression of peroxisome proliferator-activated receptor-γ coactivator 1-α (Pgc1a), suppressed by ovariectomy, and the values were significantly and inversely associated with those of Cidec/Fsp27ß. When Pgc1a-deficient mice were used, the sex differences in Cidec/Fsp27ß expression disappeared. Therefore, hepatic Cidec/Fsp27ß expression has a complex regulation influenced by diet and sex hormonal milieu. The mRNA sex differences are controlled by Pgc1a.

Prenylcysteine oxidase 1, a pro-oxidant enzyme of low density lipoproteins.

Elevated levels of low density lipoproteins (LDLs) cause atherosclerotic disease, and proteomic analyses have found that these lipoproteins are endowed with prenylcysteine lyase. This systematic review summarizes current understanding of this enzyme, now known as prenylcysteine oxidase 1 (PCYOX1), which hydrolyzes the thioether bond of prenylcysteines in the final step in the degradation of prenylated proteins, releasing hydrogen peroxide, cysteine and the isoprenoid aldehyde. Despite the high variability of the PCYOX1 gene, no polymorphism has yet been associated with any disease. The liver, which is responsible for vehiculization of the enzyme in lipoproteins, is one of the main organs responsible for its expression, together with the gastrointestinal tract, kidney, male reproductive tissue and muscle. Moreover, although hepatic mRNA expression is sensitive to diet and hormones, the repercussion of these changes in LDLs containing PCYOX1 has not been addressed. One consequence of its elevated activity could be an increase in hydrogen peroxide, which might help to propagate the oxidative burden of LDLs, thus making PCYOX1 a potential pharmacological target and a new biomarker in cardiovascular disease.

Transcriptomics and the Mediterranean Diet: A Systematic Review.

The Mediterranean diet has been proven to be highly effective in the prevention of cardiovascular diseases and cancer and in decreasing overall mortality. Nowadays, transcriptomics is gaining particular relevance due to the existence of non-coding RNAs capable of regulating many biological processes. The present work describes a systematic review of current evidence supporting the influence of the Mediterranean diet on transcriptomes of different tissues in various experimental models. While information on regulatory RNA is very limited, they seem to contribute to the effect. Special attention has been given to the oily matrix of virgin olive oil. In this regard, monounsaturated fatty acid-rich diets prevented the expression of inflammatory genes in different tissues, an action also observed after the administration of olive oil phenolic compounds. Among these, tyrosol, hydroxytyrosol, and secoiridoids have been found to be particularly effective in cell cycle expression. Less explored terpenes, such as oleanolic acid, are important modulators of circadian clock genes. The wide range of studied tissues and organisms indicate that response to these compounds is universal and poses an important level of complexity considering the different genes expressed in each tissue and the number of different tissues in an organism.

Dietary oleanolic acid mediates circadian clock gene expression in liver independently of diet and animal model but requires apolipoprotein A1.

Oleanolic acid is a triterpene widely distributed throughout the plant kingdom and present in virgin olive oil at a concentration of 57 mg/kg. To test the hypotheses that its long-term administration could modify hepatic gene expression in several animal models and that this could be influenced by the presence of APOA1-containing high-density lipoproteins (HDLs), diets including 0.01% oleanolic acid were provided to Apoe- and Apoa1-deficient mice and F344 rats. Hepatic transcriptome was analyzed in Apoe-deficient mice fed long-term semipurified Western diets differing in the oleanolic acid content. Gene expression changes, confirmed by reverse transcriptase quantitative polymerase chain reaction, were sought for their implication in hepatic steatosis. To establish the effect of oleanolic acid independently of diet and animal model, male rats were fed chow diet with or without oleanolic acid, and to test the influence of HDL, Apoa1-deficient mice consuming the latter diet were used. In Apoe-deficient mice, oleanolic acid intake increased hepatic area occupied by lipid droplets with no change in oxidative stress. Bmal1 and the other core component of the circadian clock, Clock, together with Elovl3, Tubb2a and Cldn1 expressions, were significantly increased, while Amy2a5, Usp2, Per3 and Thrsp were significantly decreased in mice receiving the compound. Bmal1 and Cldn1 expressions were positively associated with lipid droplets. Increased Clock and Bmal1 expressions were also observed in rats, but not in Apoa1-deficient mice. The core liver clock components Clock-Bmal1 are a target of oleanolic acid in two animal models independently of the diets provided, and this compound requires APOA1-HDL for its hepatic action.

Postprandial changes in high density lipoproteins in rats subjected to gavage administration of virgin olive oil.

BACKGROUND AND AIMS: The present study was designed to verify the influence of acute fat loading on high density lipoprotein (HDL) composition, and the involvement of liver and different segments of small intestine in the changes observed. METHODS AND RESULTS: To address these issues, rats were administered a bolus of 5-ml of extra-virgin olive oil and sacrificed 4 and 8 hours after feeding. In these animals, lipoproteins were analyzed and gene expressions of apolipoprotein and HDL enzymes were assessed in duodenum, jejunum, ileum and liver. Using this experimental design, total plasma and HDL phospholipids increased at the 8-hour-time-point due to increased sphingomyelin content. An increase in apolipoprotein A4 was also observed mainly in lipid-poor HDL. Increased expression of intestinal Apoa1, Apoa4 and Sgms1 mRNA was accompanied by hepatic decreases in the first two genes in liver. Hepatic expression of Abcg1, Apoa1bp, Apoa2, Apoe, Ptlp, Pon1 and Scarb1 decreased significantly following fat gavage, while no changes were observed for Abca1, Lcat or Pla2g7. Significant associations were also noted for hepatic expression of apolipoproteins and Pon1. Manipulation of postprandial triglycerides using an inhibitor of microsomal transfer protein -CP-346086- or of lipoprotein lipase -tyloxapol- did not influence hepatic expression of Apoa1 or Apoa4 mRNA. CONCLUSION: All these data indicate that dietary fat modifies the phospholipid composition of rat HDL, suggesting a mechanism of down-regulation of hepatic HDL when intestine is the main source of those particles and a coordinated regulation of hepatic components of these lipoproteins at the mRNA level, independently of plasma postprandial triglycerides.

In comparison with palm oil, dietary nut supplementation delays the progression of atherosclerotic lesions in female apoE-deficient mice.

Epidemiological studies have demonstrated the benefits of nut consumption on cardiovascular risk factors and CHD, attributed to their fatty acid profile, rich in unsaturated fatty acids, and also to other nutrients. The effect of nuts on atherosclerotic lesions was studied in female and male apoE-knockout mice fed a diet supplemented with 3 % (w/w) mixed nuts (mix: almonds, hazelnuts and walnuts in a proportion of 0.25:0·25:0.50, respectively), and compared with mice receiving an isoenergetic diet of similar fat content provided as palm oil. After 12 weeks, plasma lipid parameters and aortic lesions were measured. Males receiving nuts had lower plasma cholesterol than the palm oil group, and both sex groups had lower plasma non-HDL-cholesterol and lower content of reactive oxygen species in LDL than mice receiving the palm oil diet, the latter decrease being more pronounced in females than in males. Females consuming the nut diet showed a smaller aortic lesion area than those consuming palm oil, whereas no differences were observed in males. In females, hepatic paraoxonase 2 (Pon2) mRNA increased, and no change was observed in prenylcysteine oxidase 1 (Pcyox1) expression after the consumption of the nut-containing diet. In addition, aortic atherosclerotic lesions correlated directly with total plasma cholesterol and inversely with hepatic Pon2 expression. The results suggest that the beneficial effect of nut intake in female apoE-deficient mice may be attributed to reduced non-HDL-cholesterol levels and enhanced PON2 antioxidant activity.

Efficacy of bioactive compounds from extra virgin olive oil to modulate atherosclerosis development.

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.

Immunomodulatory properties of beta-sitosterol in pig immune responses.

The ability to control an immune response for the benefit and production efficiency of animals is the objective of immunomodulation in food-producing animals; substances that exert this control are called immunomodulators. A Spanish product (Inmunicín MAYMO®), based on food plant phytosterols, is being commercialized as complementary feed. The main component of this product is Beta-sitosterol (BSS). BSS and its glycoside (BSSG) have been shown to exhibit anti-inflammatory, anti-neoplasic, anti-pyretic and immune-modulating activity demonstrated by in vitro and in vivo experiments. The objective of the present study was to characterize the effect of BSS on the pig immune system using in vitro cell cultures first and to elucidate whether BSS possesses any in vivo activity in fattener pigs after vaccination with porcine reproductive and respiratory syndrome virus (PRRSV) modified life vaccine (MLV). Firstly, our in vitro results showed that BSS increased viable peripheral blood mononuclear cell (PBMC) numbers and it activated swine dendritic cells (DCs) in culture. Secondly, pigs treated with phytosterols prior to vaccination with PRRSV-MLV vaccine exhibited some changes in immunological parameters at different times post-vaccination, such as the proliferation ability of PBMC after phytohemaglutinin stimulation and increased apolipoprotein A1 plasma concentration which may contribute to enhance PRRSV vaccine response. In conclusion, the data in this report show that BSS can be considered an immunomodulator in pigs.

Proteomics and gene expression analyses of mitochondria from squalene-treated apoE-deficient mice identify short-chain specific acyl-CoA dehydrogenase changes associated with fatty liver amelioration.

Squalene, a hydrocarbon involved in cholesterol biosynthesis, is an abundant component in virgin olive oil. Previous studies showed that its administration decreased atherosclerosis and steatosis in male apoE knock-out mice. To study the effect of squalene on mitochondrial proteins in fatty liver, 1 g/kg/day of this isoprenoid was administered to those mice. After 10 weeks, hepatic fat was assessed and protein extracts from mitochondria enriched fractions from control and squalene-treated animals were analyzed by 2D-DIGE. Spots exhibiting significant differences were identified by MS analysis. Squalene administration modified the expression of eighteen proteins involved in different metabolic processes, 12 associated with hepatic fat content. Methionine adenosyltransferase I alpha (Mat1a) and short-chain specific acyl-CoA dehydrogenase (Acads) showed significant increased and decreased transcripts, respectively, consistent with their protein changes. These mRNAs were also studied in wild-type mice receiving squalene, where Mat1a was found increased and Acads decreased. However, this mRNA was significantly increased in the absence of apolipoprotein E. These results suggest that squalene action may be executed through a complex regulation of mitochondrial protein expression, including changes in Mat1a and Acads levels. Indeed, Mat1a is a target of squalene administration while Acads reflects the anti-steatotic properties of squalene.

Postprandial transcriptome associated with virgin olive oil intake in rat liver.

Liver has been proposed as a gatekeeper that regulates postprandial lipemia and a potential target for regulation by acute intake of virgin olive oil. To characterize the hepatic gene expression response to a fat gavage, male rats were fed a bolus of 5 ml of extra-virgin olive oil and the hepatic mRNA expression analyzed 4 hours later using DNA microarrays. To provide an initial screening of candidate genes, only twenty one with remarkably modified expression between both conditions (signal log2 ratio > 2.5 or < -2.5) were considered and confirmed by quantitative real time PCR. Those that presented biological significance were also analyzed 8 hours after the experimental approach. Hepatic A2m Slc13a5 and Nrep mRNA expressions were found significantly changed in both studied conditions and showed the highest significant associations with postprandial plasma triglycerides and lack of association with basal triglyceridemia. These results highlight new gene regulation in liver by postprandial triglyceridemia and will help to understand the complex human pathology providing the involvement of hepatic proteins and new strategies to cope with postprandial metabolism.

Diagnosis and screening for cytomegalovirus infection in pregnant women in Cuba as prognostic markers of congenital infection in newborns: 2007-2008.

BACKGROUND: Human cytomegalovirus (HCMV) has established itself as the most significant cause of congenital infection in the developed world. The objective of this research was prenatal identification of pregnant women at risk for developing active infection due to HCMV as well as to diagnose congenitally infected newborns. METHODS: A diagnostic algorithm based on specific immunoglobulin G (IgG), IgM, and, IgG avidity was used to screen serum from 1131 pregnant women enrolled prospectively from 3 municipalities from Havana City, Cuba during 2007-2008. Qualitative multiplex nested PCR and quantitative real time-based PCR testing for HCMV DNA were performed on urine and saliva specimens from women detected with active infection and from their newborns. RESULTS: Most women were seropositive to HCMV (92.7%), with 2.38% (27 women) having active infection. Primary infection was detected in 20 pregnant women (1.77%) while 7 patients (0.62%) had active nonprimary infection. HCMV DNA was detected in specimens from 9 of the 27 pregnant women by both PCR methods. HCMV congenital infection was diagnosed in 12 (1.06%) of the 26 live children born from 25 mothers with active infection, for a vertical transmission rate of 46.2%. Two fetal deaths were reported from 2 women with active infection; furthermore 2 newborns were symptomatic at birth and 2 showed sequelae during the follow-up done until 6 months age. CONCLUSIONS: Mothers with active infection during the pregnancy and with HCMV excretion had significant risks, RR = 1.16 and RR = 1.35, respectively, to have congenitally infected children.

Cysteinemia, rather than homocysteinemia, is associated with plasma apolipoprotein A-I levels in hyperhomocysteinemia: lipid metabolism in cystathionine beta-synthase deficiency.

OBJECTIVE: Genetic and dietary hyperhomocysteinemia has been found to decrease high density lipoproteins (HDL) and their apolipoprotein A1 (APOA1). To test the hypothesis that the presence of cysteine could normalize HDL levels in hyperhomocysteinemic cystathionine beta-synthase (Cbs)-deficient mice and that the inclusion of glycine would block this effect. METHODS: Lipids and HDL cholesterol were studied in Cbs-deficient mice and wild-type animals fed a low-methionine diet supplemented with cysteine and glycine and in Cbs-deficient mice on the same diet supplemented only with cysteine. RESULTS: Triglyceride and homocysteine levels were significantly decreased and increased, respectively in Cbs-deficient mice irrespective of treatment. However, plasma cholesterol, glucose and APOA1 were significantly decreased in homozygous Cbs-deficient mice when they received the cysteine and glycine-enriched beverage. This group of mice also showed decreased mRNA levels and increased hepatic content of APOA1 protein, the latter increase was observed in endothelial cells. A significant, inverse relationship was observed between plasma and hepatic APOA1 concentrations while a positive one was found between plasma levels of cysteine and APOA1. CONCLUSION: These data suggest an altered hepatic management of APOA1 and that cysteine may be involved in the control of this apolipoprotein at this level. Overall these findings represent a new aspect of dietary regulation of HDL at the hepatic transendothelial transport.

Olive oils modulate fatty acid content and signaling protein expression in apolipoprotein E knockout mice brain.

Atherosclerosis contributes to disruption of neuronal signaling pathways by producing lipid-dependent modifications of brain plasma membranes, neuroinflammation and oxidative stress. We investigated whether long-term (11 weeks) consumption of refined- (ROO) and pomace- (POO) olive oil modulated the fatty acid composition and the levels of membrane signaling proteins in the brain of apolipoprotein E (apoE) knockout (KO) mice, an animal model of atherosclerosis. Both of these oils are rich in bioactive molecules with anti-inflammatory and antioxidant effects. ROO and POO long-term consumption increased the proportion of monounsaturated fatty acids (MUFAs), particularly of oleic acid, while reducing the level of the saturated fatty acids (SFAs) palmitic and stearic acid. As a result, the MUFA:SFA ratio was higher in apoE KO mice brain fed with ROO and POO. Furthermore, both oils reduced the level of arachidonic and eicosapentaenoic acid, suggesting a decrease in the generation of pro- and anti-inflammatory eicosanoids. Finally, ROO and POO induced an increase in the density of membrane proteins implicated in both the Galphas/PKA and Galphaq/PLCbeta1/PKCalpha signaling pathways. The combined effects of long-term ROO and POO consumption on fatty acid composition and the level of signaling proteins involved in PKA and PKC activation, suggest positive effects on neuroinflammation and brain function in apoE KO mice brain, and convert these oils into promising functional foods in diseases involving apoE deficiency.

Knowledge of the biological actions of extra virgin olive oil gained from mice lacking apolipoprotein E.

The low incidence of cardiovascular disease in countries bordering the Mediterranean basin, where olive oil is the main source of dietary fat, has stimulated interest in the chemical composition of olive oil and in the production of other oils enriched with its minor components. This review summarizes what has been learned about the effects of different olive oil preparations on the development of atherosclerosis and about the prognostic value of associated plasma variables in the disease from experiments on genetically modified mice that spontaneously develop atherosclerosis. The limitations of this animal model associated with its morphological and physiological differences with humans are minimized by the similarity of the two genomes and by the potential for increased understanding attainable, given that the dietary interventions reported here would have taken 400 years to achieve in humans. As observed in traditional Mediterranean populations, it has been confirmed that extra virgin olive oil is beneficial when consumed judiciously and in a diet that is low in cholesterol due to the relative scarcity of animal products. Furthermore, the use of genomic techniques has led to the identification of new markers of response to olive oil. In conclusion, multidisciplinary research into extra virgin olive oil is expanding our knowledge of the substance's biological properties.