Fermentation profile, cholesterol-reducing properties and chemopreventive potential of ß-glucans from Levilactobacillus brevis and Pediococcus claussenii - a comparative study with ß-glucans from different sources.

The aim of the present study was to investigate whether ß-glucans obtained from the lactic acid bacteria (LAB) Levilactobacillus (L.) brevis and Pediococcus (P.) claussenii exhibit similar physiological effects such as cholesterol-binding capacity (CBC) as the structurally different ß-glucans from oat, barley, and yeast as well as curdlan. After in vitro fermentation, fermentation supernatants (FSs) and/or -pellets (FPs) were analyzed regarding the concentrations of short-chain fatty acids (SCFAs), ammonia, bile acids, the relative abundance of bacterial taxa and chemopreventive effects (growth inhibition, apoptosis, genotoxicity) in LT97 colon adenoma cells. Compared to other glucans, the highest CBC was determined for oat ß-glucan (65.9 ± 8.8 mg g-1, p < 0.05). Concentrations of SCFA were increased in FSs of all ß-glucans (up to 2.7-fold). The lowest concentrations of ammonia (down to 0.8 ± 0.3 mmol L-1) and bile acids (2.5-5.2 µg mL-1) were detected in FSs of the ß-glucans from oat, barley, yeast, and curdlan. The various ß-glucans differentially modulated the relative abundance of bacteria families and reduced the Firmicutes/Bacteroidetes ratio. Treatment of LT97 cells with the FSs led to a significant dose-dependent growth reduction and increase in caspase-3 activity without exhibiting genotoxic effects. Though the different ß-glucans show different fermentation profiles as well as cholesterol- and bile acid-reducing properties, they exhibit comparable chemopreventive effects.

Study on chemopreventive effects of raw and roasted ß-glucan-rich waxy winter barley using an in vitro human colon digestion model.

Due to their unique dietary fibre composition, in particular ß-glucan, the consumption of barley may contribute to a healthy diet and the prevention of colon cancer. The aim of the present study was to analyse chemopreventive effects of barley flakes obtained from a ß-glucan-rich barley cultivar. In order to address the impact of heat treatment on potential chemopreventive effects, barley flakes were roasted (160 °C-180 °C, approx. 20 min). The flakes were subjected to in vitro digestion and fermentation. Fermentation supernatants (FS) were analysed for the concentrations of short-chain fatty acids (SCFA) and ammonia. Chemopreventive endpoints (growth inhibition, apoptosis, DNA integrity, gene expression of detoxifying enzymes) were analysed in LT97 colon adenoma cells. Concentrations of SCFA were increased in barley FS (2.5-fold, on average) with a shift of molar ratios towards butyrate production, while ammonia levels were significantly decreased (0.7-fold, on average) compared to the fermentation control. The growth of LT97 cells was significantly reduced by barley FS in a time- and dose-dependent manner, and caspase-3 activity of treated cells was significantly enhanced (up to 6.3-fold, on average). On average, treatment of cells resulted in increased mRNA levels of CAT (2.1-fold), SOD2 (2.2-fold) and GSTP1 (3.9-fold), while expression of GPx1 (0.3-fold) was significantly decreased in some cases. The roasting process did not cause genotoxic effects of barley FS and had no impact on chemopreventive properties. Our results indicate chemopreventive potential of in vitro fermented waxy winter barley, mediated primarily by growth inhibitory and apoptotic effects, which is largely unaffected by roasting.

Impact of different roasting conditions on sensory properties and health-related compounds of oat products.

Due to their high content of ß-glucan, the consumption of oat products can contribute to a healthy diet. Roasting may improve sensory properties but could also affect the nutritional value of oat products. Therefore, the aim of the present study was to analyse the impact of different roasting conditions (140-180 °C, approx. 20 min) on sensory quality, health-related compounds (e.g. acrylamide, ß-glucan) and viscosities of oat kernels and flakes. Roasting resulted in oat flakes with improved sensory properties. Acrylamide formation increased with higher roasting temperatures in kernels, thin and thick flakes. Contents of fat, protein, starch and ß-glucan were not affected by roasting, whereas dietary fibre fractions were marginally modulated. Viscosities were significantly reduced with increasing roasting temperatures. The results indicate that roasting up to 160 °C is a processing technique with potential to generate oat products with improved sensory quality and favourable nutritional composition.

Impact of different roasting conditions on chemical composition, sensory quality and physicochemical properties of waxy-barley products.

The consumption of ß-glucan-rich barley can contribute to a healthy diet. Sensory properties may be improved by roasting whereby the nutritional value should be preserved. The aim of the present study was to investigate the impact of different roasting conditions (160-200 °C, 20 minutes) on sensory quality, health-related compounds and viscosity in ß-glucan-rich barley kernels, thin and thick flakes. Sensory quality was improved by roasting. Acrylamide levels increased due to roasting to maximum values of 322 µg kg-1 (kernels), 586 µg kg-1 (thin flakes) and 804 µg kg-1 (thick flakes). No relevant impact of roasting on the contents of fat, protein, starch and ß-glucan was observed, whereas dietary fibre fractions were marginally modulated. Roasting significantly decreased viscosity 1.9-fold (kernels), 2.4-fold (thin flakes) and 2.7-fold (thick flakes), on average. In conclusion, improved sensory quality along with a favourable healthy composition of barley products may be achieved by roasting over a low to medium temperature range.

Short communication: Changes under low ambient temperatures in the milk lipodome and metabolome of mid-lactation cows after dehorning as a calf.

Horns are living tissue and cows can use their horns for thermoregulatory purposes. We investigated the effect of the presence of horns on the metabolome of milk serum and lipidome of milk fat, to assess the physiological effect of dehorning. Milk sampling took place at low ambient temperatures of -6 to 2°C. Horned and dehorned cows were kept in a mixed herd of Holstein Friesian and Brown Swiss cows. The hypothesis was that horned cows needed to increase their metabolism to compensate for additional heat loss through the presence of their horns. No differences were observed in milk yield, milk solids, and somatic cell counts between horned and dehorned cows. For the milk metabolome, horned cows showed an upregulation of several glucogenic AA that could be transformed into glucose for energy supply and a downregulation of sugar intermediates and γ-glutamylcysteine compared with dehorned cows. The fatty acid (FA) composition in horned cows showed a shift toward decreased odd medium-chain FA (C7:0, C9:0, and C11:0) and increased cis-vaccenic acid (C18:1n-7 cis-11) and stearidonic acid (C18:4n-3). The changes in milk composition related to additional heat loss in horned cows indicate a competition in C3 metabolism for glucose synthesis and de novo FA synthesis under cold stress.

Docosahexaenoic acid in the treatment of rheumatoid arthritis: A double-blind, placebo-controlled, randomized cross-over study with microalgae vs. sunflower oil.

The potential of fish or fish oil as supplier for eicosapentaenoic acid (EPA, C20:5n3) and docosahexaenoic acid (DHA, C22:6n3) for reducing cardiovascular risk factors and supporting therapy of chronic inflammatory diseases, has been investigated intensively, but our knowledge about the physiological effects of the individual compounds EPA and DHA are limited. STUDY DESIGN: In this double-blind pilot study, thirty-eight patients with defined RA were allocated to consume foods enriched with microalgae oil from Schizochytrium sp. (2.1 g DHA/d) or sunflower oil (placebo) for 10 weeks (cross-over), maintaining the regular RA medication during the study. RESULTS: In contrast to placebo, the daily consumption of DHA led to a decline in the sum of tender and swollen joints (68/66) from 13.9 ± 7.4 to 9.9 ± 7.0 (p = 0.010), total DAS28 from 4.3 ± 1.0 to 3.9 ± 1.2 (p = 0.072), and ultrasound score (US-7) from 15.1 ± 9.5 to 12.4 ± 7.0 (p = 0.160). The consumption of placebo products caused an increase of the n-6 PUFA linoleic acid and arachidonic acid (AA) in erythrocyte lipids (EL, p < 0.05). The amount of DHA was doubled in EL of DHA-supplemented patients and the ratios of AA/EPA and AA/DHA dropped significantly. We speculate that the production of pro-inflammatory/non-resolving AA-derived eicosanoids might decrease in relation to anti-inflammatory/pro-resolving DHA- and EPA-derived lipid mediators. In fact, plasma concentrations of AA-derived thromboxane B2 and the capacity of blood to convert AA to the pro-inflammatory 5-lipoxygenase product 5-hydroxyeicosatetraenoic acid were significantly reduced, while levels of the DHA-derived maresin/resolvin precursors 14-/17-hydroxydocosahexaenoic acid significantly increased due to DHA supplementation. CONCLUSION: The study shows for the first time that supplemented microalgae DHA ameliorates disease activity in patients with RA along with a shift in the balance of AA- and DHA-derived lipid mediators towards an anti-inflammatory/pro-resolving state.

In vitro-fermented raw and roasted walnuts induce expression of CAT and GSTT2 genes, growth inhibition, and apoptosis in LT97 colon adenoma cells.

Walnuts are rich in bioactive compounds such as polyunsaturated fatty acids, polyphenols, and dietary fiber. Therefore, the consumption of walnuts can contribute to a healthy diet and may reduce the risk for colon cancer. Heat treatment like roasting may change the chemical composition of walnuts and therefore their chemopreventive properties. Therefore, the hypothesis of the present study is that different roasting conditions (RCs) alter the chemopreventive effects of walnuts. Thus, the aim of the present study was to investigate whether different RCs (RC1=139.7°C/25 min, RC2=154.5°C/20 min, and RC3=185.5°C/25 min) alter the chemopreventive effects of walnuts. Raw and roasted walnuts were subjected to in vitro digestion and fermentation. After treatment of LT97 colon adenoma cells with fermentation supernatants (FSs), expression of CAT, SOD2, GPx1, GSTP1, and GSTT2 genes as well as cell growth and apoptosis was examined. In comparison to the fermentation blank control, walnut FS particularly increased mRNA levels of CAT 1.7-fold and GSTT2 3.1-fold, whereas GPx1 levels were significantly decreased 0.6-fold. Walnut FS decreased growth of adenoma cells in a time- and dose-dependent manner. In particular, higher concentrations of walnut FS (5%) significantly increased the number of early apoptotic cells 2.0-fold and induced caspase-3 activity 6.8-fold compared with the blank control. The roasting process had no direct impact on the observed effects. In sum, our results indicate that walnuts exhibit chemopreventive effects regarding the risk for colon cancer development by inducing expression of genes involved in detoxification (CAT, GSTT2) and by inducing growth inhibition and apoptosis in colon adenoma cells unaffected by moderate roasting.

CYP4F2 repression and a modified alpha-tocopherol (vitamin E) metabolism are two independent consequences of ethanol toxicity in human hepatocytes.

The expression of CYP4F2, a form of cytochrome P-450 with proposed role in α-tocopherol and long-chain fatty acid metabolism, was explored in HepG2 and HepaRG human hepatocytes during ethanol toxicity. Cytotoxicity, ROS production, and JNK and ERK1/2 kinase signaling increased in a dose and time-dependent manner during ethanol treatments; CYP4F2 gene expression decreased, while other CYP4F forms, namely 4F11 and 12, increased along with 3A4 and 2E1 isoforms. α-Tocopherol antagonized the cytotoxicity and CYP4F2 gene repression effect of ethanol in HepG2 cells. Ethanol stimulated the tocopherol-ω-hydroxylase activity and the other steps of vitamin E metabolism, which points to a minor role of CYP4F2 in this metabolism of human hepatocytes. PPAR-γ and SREBP-1c followed the same expression pattern of CYP4F2 in response to ethanol and α-tocopherol treatments. Moreover, the pharmacological inhibition of PPAR-γ synergized with ethanol in decreasing CYP4F2 protein expression, which suggests a role of this nuclear receptor in CYP4F2 transcriptional regulation. In conclusion, ethanol toxicity modifies the CYP expression pattern of human hepatic cells impairing CYP4F2 transcription and protein expression. These changes were associated with a lowered expression of the fatty acid biosynthesis regulators PPAR-γ and SREBP-1c, and with an increased enzymatic catabolism of vitamin E. CYP4F2 gene repression and a sustained vitamin E metabolism appear to be independent effects of ethanol toxicity in human hepatocytes.

Changes in Quality of Diabetes Care and Morbidity over 20 Years in People with Type 1 Diabetes and Long Diabetes Duration: The JEVIN Trial.

Background: The JEVIN trial started as a cross-sectional study in 1989/90 in Jena, a city of the former German Democratic Republic. At that time, the centralized diabetes care system was broken down and restarted 10 years later; structured treatment and teaching programs were implemented, blood glucose self-monitoring, insulin pump-systems and analogue insulin were introduced. We surveyed people with type-1-diabetes of the baseline JEVIN trial in a 20-year follow-up. Methods: 131 patients with type-1-diabetes were analyzed in 1989/90. Of the living population in 2009/10 (n=104), 83 persons were identified and 75 persons with a mean diabetes duration of 35 years were reexamined regarding HbA1c, self-monitoring, diabetes therapy, severe hypoglycemia, diabetic late complications and compared with the results of the same persons in 1989/90. Results: HbA1c decreased from 57.1 mmol/mol in 1989/90 to 52.7 mmol/mol in 2009/10 (7.4 -7.0%; p=0.049). Self-monitoring of blood glucose increased from 2 to 35 tests/week (p<0.001). 100%-use of animal insulin changed to human and analogue insulin therapy. The incidence of severe hypoglycemia increased from 0.1 to 0.16/patient-year. Retinopathy increased from 29 to 69% (p<0.001), nephropathy from 5 to 27% (p<0.001) and neuropathy from 13 to 43% (p<0.001). 17% had no diabetic late complications. Conclusions: The JEVIN trial shows a significant improve in HbA1c in the past 20 years. Severe hypoglycemia occurred rarely and 17% were still free of any diabetic late complication after 35 years of diabetes. This indicates a good quality of diabetes care in a German setting.

Principles of self-adjustment of insulin dose in people with diabetes type 2 and flexible insulin therapy.

AIMS: Structured treatment and education programmes for people with type 2 diabetes mellitus (T2DM) and flexible insulin therapy provide rules for self-adjustment of insulin dose, that are extensively trained. The aim of this cohort study was to register current principles and the frequency of self-adjustment of insulin dose and their association with metabolic control in people with T2DM. METHODS: Details of insulin dose adjustment were assessed by a structured interview in 149 people with T2DM on flexible insulin therapy (mean HbA1c 7.1%/53.8mmol/mol, age 65y, diabetes duration 19.0y, BMI 33.8kg/m(2)) in a tertiary care centre. The frequency of insulin dose adjustments was obtained from the last 28days of the patients' diaries. RESULTS: Insulin dose adjustment by adjustment rules was used by 33 people (22.1%) and by personal experience/feeling in 111 participants (74.5%). People adjusting by rules were younger (60.9±9.8 vs. 65.7±9.2, p=0.011) and did more insulin dose adjustments per 28days (50.0±31.0 vs. 33.4±23.5, p=0.016). HbA1c and incidence of hypoglycaemia were comparable. There were no differences in satisfaction of treatment, quality of life as well as current well-being between the groups. CONCLUSIONS: Only a fifth of the participants used the rule trained within the education programme to adjust their insulin dose. The majority adjusted their insulin dose by personal experience/feeling. However, people in both groups were able to adjust their insulin dose. Although people using adjustment rules adjust their insulin dose more frequently, HbA1c and the incidence of hypoglycaemia was similar compared to those using personal experience/feeling.

Diabetes-Related Burden and Distress is Low in People with Diabetes at Outpatient Tertiary Care Level.

OBJECTIVE: The importance of diabetes-related distress (DRD) for the treatment of diabetes is emphasized in national and international guidelines recommending routinely screening for psychosocial problems. To detect DRD, the PAID (Problem Area In Diabetes) questionnaire provides a valid and reliable instrument. RESEARCH DESIGN AND METHODS: 783 patients with diabetes mellitus type 1 (DM1, n=191, age 54.5 y, diabetes duration 22.5 y, HbA1c 7.2% (55 mmol/mol)) and type 2 (DM2, n=592, age 66.6 y, diabetes duration 15.6 y, HbA1c 7.0% (60.1 mmol/mol)) were interviewed with the PAID and WHO-5 questionnaire in a University outpatient department for endocrinology and metabolic diseases in 2012. A PAID score≥40 (range 0-100) was considered as high DRD. RESULTS: The mean PAID score was 17.1±15.1 in all participants. Only 8.9% of all responders showed high DRD (score≥40). The PAID score neither differed in people with DM1 and DM2, nor between participants with DM2 with or without insulin therapy. Females achieved significantly higher scores than men (19.0±16.6 vs. 15.6±13.7, p=0.003). A strong negative correlation existed between the PAID score and the WHO-5 Well-being Index (r=- 0.482, p<0.001). A 10 points higher WHO-5 Well-being Index was associated with 15.9 points lower PAID score in people with DM1 (p<0.001), and 9.2 points lower PAID score in DM2 (p<0.001), respectively. One percent higher HbA1c was associated with an increase of diabetes-related distress by 2.5 points in people with DM1 and by 2.0 points in people with DM2. CONCLUSIONS: Less than 10% of our outpatients with diabetes showed high diabetes-related distress.

In vitro fermentation of nuts results in the formation of butyrate and c9,t11 conjugated linoleic acid as chemopreventive metabolites.

PURPOSE: The consumption of foods rich in dietary fiber and polyunsaturated fatty acids such as nuts can contribute to a healthy diet. Therefore, the formation of fermentation end-products which might exert chemopreventive effects regarding colon cancer was investigated after an in vitro simulated digestion and fermentation of nuts using human fecal microbiota. METHODS: Fermentation supernatants (FS) and pellets (FP) were obtained after an in vitro fermentation of hazelnuts, almonds, macadamia, pistachios and walnuts. Short-chain fatty acids (SCFA) and bile acids (BA) in FS as well as fatty acids in FP were analyzed via gas chromatography. Malondialdehyde (MDA) levels in FS were determined photometrically. RESULTS: Fermentation of nuts resulted in 1.9- to 2.8-fold higher concentrations of SCFA compared to the control and a shift of molar ratios toward butyrate production. In vitro fermentation resulted in the formation of vaccenic acid (C18:1t11, 32.1 ± 3.2 % FAME; fatty acid methyl ester) and conjugated linoleic acid (c9,t11 CLA, 2.4 ± 0.7 % FAME) exclusively in fermented walnut samples. Concentrations of secondary BA deoxycholic-/iso-deoxycholic acid (6.8-24.1-fold/4.9-10.9-fold, respectively) and levels of MDA (1.3-fold) were significantly reduced in fermented nut samples compared to the control. CONCLUSION: This is the first study that demonstrates the ability of the human fecal microbiota to convert polyunsaturated fatty acids from walnuts to c9,t11 CLA as a potential chemopreventive metabolite. In addition, the production of butyrate and reduction in potential carcinogens such as secondary BA and lipid peroxidation products might contribute to the protective effects of nuts regarding colon cancer development.

Saturated fatty acids are not off the hook.

A recent meta-analysis by Chowdhury et al. (2014) has disclaimed the association between coronary artery diseases and either circulating blood levels or the intake of total saturated fatty acids (SFA). Scrutiny revealed that two of the eight studies included in the meta-analysis focused on the proportion of pentadecanoic acid (C15:0) and heptadecanoic acid (C17:0) and their impact on cardiovascular disease (CVD) risk. These odd-chain fatty acids are markers for milk or ruminant fat intake. Both studies indicated inverse associations between milk-fat intake and first-ever myocardial infarction. Neither of the two studies described the association between total circulating blood SFA on coronary outcomes. In contrast to the cardioprotective effects of dairy consumption, we expected that an elevated intake of palmitic acid (C16:0) and stearic acid (C18:0) de novo may raise CVD risk. Thus, it is of particular importance to differentiate the effects of individual circulating SFA on cardiovascular outcomes. Excluding the studies that evaluated the association of fatty acids from milk fat and cardiovascular outcomes revealed a positive association of total SFA blood levels and coronary outcome (RR 1.21, CI 1.04-1.40). Therefore, results obtained from studies of C15:0 and C17:0 cannot be mixed with results from studies of other SFA because of the opposite physiological effects of regular consumption of foods rich in C16:0 and C18:0 compared to high intake of milk or ruminant fat. In our opinion, it is vital to analyze the impact of individual SFA on CVD incidence in order to draw prudent conclusions.

Influence of roasting conditions on health-related compounds in different nuts.

Due to their health-beneficial ingredients the consumption of nuts can contribute to a healthy diet. The composition of hazelnuts, almonds, macadamia nuts, pistachios and walnuts regarding health-promoting and potentially harmful compounds was examined before and after roasting under different time and temperature conditions. Fatty acid compositions were not affected by roasting. Malondialdehyde increased with higher roasting temperatures (17-fold in walnuts). Levels of tocopherol isomers were reduced after roasting (α-T: 38%, ß-T: 40%, γ-T: 70%) and hydrophilic antioxidant capacity decreased significantly in hazelnuts (1.4-fold), macadamia nuts (1.7-fold) and walnuts (3.7-fold). Increasing roasting temperatures supported the formation of significant amounts of acrylamide only in almonds (1220 µg kg(-1)). In general, nuts roasted at low/middle temperatures (120-160°C) exhibited best sensory properties. Therefore, desired sensory quality along with a favourable healthy nut composition may be achieved by roasting over a low to medium temperature range.

Exogenous nitric oxide regulates activity and synthesis of vascular endothelial nitric oxide synthase.

BACKGROUND: Nitric oxide (NO) - a major signalling molecule of the vascular system - is constitutively produced in endothelial cells (EC) by the endothelial NO synthase (eNOS). Since a reduced NO synthesis is an early sign of endothelial dysfunction and NO delivering drugs are used to substitute the impaired endothelial NO production, we addressed the effect of exogenous NO on eNOS in human umbilical venous endothelial cell cultures. MATERIALS AND METHODS: The synthetic NO donor DETA/NO (trade name, but in the following we refer to detNO), that releases NO in a strictly first order reaction with a half life of 20 h, was used in our experiments. RESULTS: Short-term (20-30 min) detNO treatment of EC increases the Ser(1177) phosphorylation of the constitutively expressed endothelial NOS and the production of endogenous NO generated by eNOS from [(3)H]arginine. The phosphorylation of eNOS is Akt-dependent and completely reverted by the phosphatidylinositol-3 kinase (PI-3K) inhibitor LY294002. A prolonged continuous exposure of EC to detNO 150 micromol L(-1) over a period of 24-48 h causes a reversible cell cycle arrest at G(1)-phase associated with a larger cell volume and increased cell protein content (hypertrophic phenotype of EC). The eNOS protein and mRNA of the hypertrophic cells and the generation of endogenous NO are reduced but eNOS phosphorylation could still be elevated by stimulation with vascular endothelial growth factor. CONCLUSIONS: Our data explain clinical studies describing a short-term but not a long-term benefit of NO treatment for patients with cardiovascular risk factors. The results could be a rational approach to develop a generation of NO donors accomplishing a retarded release from NO donors that mimic the low continuous pulsatile stress-induced release of endogenous NO.

TGF-beta1 generates a specific multicomponent extracellular matrix in human coronary SMC.

BACKGROUND: Transforming growth factor (TGF-beta(1)) is postulated to play an important role in maintaining the structure and function of arterial tissue and protection against development of arteriosclerosis. The TGF-beta(1)-induced production of a stable extra-cellular matrix-rich plaque phenotype is suggested to be part of the protection against a switch to an unstable rupture-prone arteriosclerotic plaque. MATERIALS AND METHODS: This study addresses the question of whether the expression profile and the type of extra-cellular matrix (ECM) generated by TGF-beta(1) stimulation have the structural feature of a fibril-rich stable matrix. Seventeen genes codings for ECM components of human coronary smooth muscle cells (SMCs) after a 24-h stimulation by TGF-beta(1) have been analyzed. RESULTS: Real-time RT-PCR was used to quantify the mRNA of genes under investigation. It was found that after TGF-beta(1) stimulation (a) the up-regulation of COL1A1-specific mRNA was associated with increased [(3)H]proline incorporation into the alpha-1 and -2 chains of collagen type I, (b) the up-regulation of biglycan- and syndecan-1-specific mRNA corresponded to an increased [(35)S]sulphate and [4,5-(3)H]leucine incorporation into the biglycan molecule and to an increase of syndecan-1 protein, (c) the up-regulated FGF-2 gene accounted predominantly for the ECM-bound subfraction of FGF-2-protein and (d) fibronectin and thrombospondin exhibited a significantly higher mRNA level. In contrast collagen XIV, a minor collagen type, and the proteoglycan decorin were down-regulated. The down-regulated decorin changed its structure by elongation and reduced GlcA to IdoA epimerization of the dermatan sulphate side-chain as judged by [(35)S]sulphate metabolic labelling experiments. No significant changes in response to TGF-beta(1) were observed for the collagen types III, VI and XVI, for versican, perlecan and the syndecans-2 and -4. CONCLUSIONS: It was concluded from the data that the TGF-beta(1)-induced formation of a highly specific multicomponent extra-cellular matrix on coronary arterial SMCs could provide in vivo mechanical strength to the neointima in arteriosclerotic lesions and to the fibrous cap overlying the lipid core.

The pathogenesis of atherosclerosis.

Worldwide, more people die of the complications of atherosclerosis than of any other cause. It is not surprising, therefore, that enormous resources have been devoted to studying the pathogenesis of this condition. This article attempts to summarize present knowledge on the events that take place within the arterial wall during atherogenesis. Classical risk factors are not dealt with as they are the subjects of other parts of this book. First, we deal with the role of endothelial dysfunction and infection in initiating the atherosclerotic lesion. Then we describe the development of the lesion itself, with particular emphasis on the cell types involved and the interactions between them. The next section of the chapter deals with the events leading to thrombotic occlusion of the atherosclerotic vessel, the cause of heart attack and stroke. Finally, we describe the advantages--and limitations--of current animal models as they contribute to our understanding of atherosclerosis and its complications.

The human ABCG4 gene is regulated by oxysterols and retinoids in monocyte-derived macrophages.

Here we report the induction of gene expression of ABCG4, a member of the ABC transporter subfamily G, from human macrophages by oxysterols and retinoids, agonists of the nuclear receptors LXR and RXR. The cloned ABCG4 transcript has a size of 3.5 kb and contains an open reading frame which encodes a polypeptide of 646 amino acids. Structurally, the putative ABC transporter protein consists of a nucleotide binding fold followed by a cluster of six transmembrane-spanning domains and thus conforms to the group of half-size ABC transporters. Among the human ABC transporter subfamily G members the novel transporter shows highest protein sequence homology and identity to ABCG1 (84 and 72%, respectively). Analysis of the genomic organization demonstrates that the ABCG4 gene is composed of at least 14 exons which extend across a region of 12.6 kb in size on chromosome 11q23.3. Based on its structural features and an LXR/RXR-responsive regulation similar to the cellular lipid export protein ABCA1, we conclude that ABCG4 may be involved in macrophage lipid homeostasis.

Apolipoprotein E in macrophages and hepatocytes is eegraded via the proteasomal pathway.

Macrophage-derived apolipoprotein E (apoE) influences the susceptibility of the arterial wall to atherosclerosis. Previous studies have shown that production of apoE in these cells is regulated at a posttranscriptional level and is increased by inhibitors of proteasomal degradation. To further investigate this mechanism, we stably transfected RAW 264.7 macrophages and HepG2 cells with a construct overexpressing ubiquitin, the peptide targeting proteins to the proteasome, fused to an influenza virus hemagglutinin epitope tag. Ubiquitination of apoE was investigated by immunoprecipitation and Western blot analysis. In both cell types, apoE was ubiquitinated, and inhibition of proteasome function by lactacystin led to accumulation of ubiquitinated apoE. These studies provide strong evidence for proteasomal degradation of apoE in the two main cell types responsible for its production and indicate a possible new level of regulation of this important protein.