Role of Esrrg in the Fibrate-Mediated Regulation of Lipid Metabolism Genes in Human ApoA-I Transgenic Mice

We have used a new ApoA-I transgenic mouse model to identify by global gene expression profiling, candidate genes that affect lipid and lipoprotein metabolism in response to fenofibrate treatment. Multilevel bioinformatical analysis and stringent selection criteria (2-fold change, 0% false discovery rate) identified 267 significantly changed genes involved in several molecular pathways. The fenofibrate-treated group did not have significantly altered levels of hepatic human APOA-I mRNA and plasma ApoA-I compared with the control group. However, the treatment increased cholesterol levels to 1.95-fold mainly due to the increase in high-density lipoprotein (HDL) cholesterol. The observed changes in HDL are associated with the upregulation of genes involved in phospholipid biosynthesis and lipid hydrolysis, as well as phospholipid transfer protein. Significant upregulation was observed in genes involved in fatty acid transport and β-oxidation, but not in those of fatty acid and cholesterol biosynthesis, Krebs cycle and gluconeogenesis. Fenofibrate changed significantly the expression of seven transcription factors. The estrogen receptor-related gamma gene was upregulated 2.36-fold and had a significant positive correlation with genes of lipid and lipoprotein metabolism and mitochondrial functions, indicating an important role of this orphan receptor in mediating the fenofibrate-induced activation of a specific subset of its target genes.National Institutes of Health (HL48739 and HL68216); European Union (LSHM-CT-2006-0376331, LSHG-CT-2006-037277); the Biomedical Research Foundation of the Academy of Athens; the Hellenic Cardiological Society; the John F Kostopoulos Foundatio

Universal architecture of bacterial chemoreceptor arrays

Chemoreceptors are key components of the high-performance signal transduction system that controls bacterial chemotaxis. Chemoreceptors are typically localized in a cluster at the cell pole, where interactions among the receptors in the cluster are thought to contribute to the high sensitivity, wide dynamic range, and precise adaptation of the signaling system. Previous structural and genomic studies have produced conflicting models, however, for the arrangement of the chemoreceptors in the clusters. Using whole-cell electron cryo-tomography, here we show that chemoreceptors of different classes and in many different species representing several major bacterial phyla are all arranged into a highly conserved, 12-nm hexagonal array consistent with the proposed “trimer of dimers” organization. The various observed lengths of the receptors confirm current models for the methylation, flexible bundle, signaling, and linker sub-domains in vivo. Our results suggest that the basic mechanism and function of receptor clustering is universal among bacterial species and was thus conserved during evolution

Reduced phosphorylation of brain insulin receptor substrate and Akt proteins in apolipoprotein-E4 targeted replacement mice

10.1038/srep03754Scientific Reports4

LDL Receptor Knock-Out Mice Are a Physiological Model Particularly Vulnerable to Study the Onset of Inflammation in Non-Alcoholic Fatty Liver Disease

Non-alcoholic steatohepatitis (NASH) involves steatosis combined with inflammation, which can progress into fibrosis and cirrhosis. Exploring the molecular mechanisms of NASH is highly dependent on the availability of animal models. Currently, the most commonly used animal models for NASH imitate particularly late stages of human disease. Thus, there is a need for an animal model that can be used for investigating the factors that potentiate the inflammatory response within NASH. We have previously shown that 7-day high-fat-high-cholesterol (HFC) feeding induces steatosis and inflammation in both APOE2ki and Ldlr(-/-) mice. However, it is not known whether the early inflammatory response observed in these mice will sustain over time and lead to liver damage. We hypothesized that the inflammatory response in both models is sufficient to induce liver damage over time.APOE2ki and Ldlr(-/-) mice were fed a chow or HFC diet for 3 months. C57Bl6/J mice were used as control.Surprisingly, hepatic inflammation was abolished in APOE2ki mice, while it was sustained in Ldlr(-/-) mice. In addition, increased apoptosis and hepatic fibrosis was only demonstrated in Ldlr(-/-) mice. Finally, bone-marrow-derived-macrophages of Ldlr(-/-) mice showed an increased inflammatory response after oxidized LDL (oxLDL) loading compared to APOE2ki mice.Ldlr(-/-) mice, but not APOE2ki mice, developed sustained hepatic inflammation and liver damage upon long term HFC feeding due to increased sensitivity for oxLDL uptake. Therefore, the Ldlr(-/-) mice are a promising physiological model particularly vulnerable for investigating the onset of hepatic inflammation in non-alcoholic steatohepatitis

The multiplex bead array approach to identifying serum biomarkers associated with breast cancer

Introduction Breast cancer is the most common type of cancer seen in women in western countries. Thus, diagnostic modalities sensitive to early-stage breast cancer are needed. Antibody-based array platforms of a data-driven type, which are expected to facilitate more rapid and sensitive detection of novel biomarkers, have emerged as a direct, rapid means for profiling cancer-specific signatures using small samples. In line with this concept, our group constructed an antibody bead array panel for 35 analytes that were selected during the discovery step. This study was aimed at testing the performance of this 35-plex array panel in profiling signatures specific for primary non-metastatic breast cancer and validating its diagnostic utility in this independent population. Methods Thirty-five analytes were selected from more than 50 markers through screening steps using a serum bank consisting of 4,500 samples from various types of cancer. An antibody-bead array of 35 markers was constructed using the Luminex (TM) bead array platform. A study population consisting of 98 breast cancer patients and 96 normal subjects was analysed using this panel. Multivariate classification algorithms were used to find discriminating biomarkers and validated with another independent population of 90 breast cancer and 79 healthy controls. Results Serum concentrations of epidermal growth factor, soluble CD40-ligand and proapolipoprotein A1 were increased in breast cancer patients. High-molecular-weight-kininogen, apolipoprotein A1, soluble vascular cell adhesion molecule-1, plasminogen activator inhibitor-1, vitamin-D binding protein and vitronectin were decreased in the cancer group. Multivariate classification algorithms distinguished breast cancer patients from the normal population with high accuracy (91.8% with random forest, 91.5% with support vector machine, 87.6% with linear discriminant analysis). Combinatorial markers also detected breast cancer at an early stage with greater sensitivity. Conclusions The current study demonstrated the usefulness of the antibody-bead array approach in finding signatures specific for primary non-metastatic breast cancer and illustrated the potential for early, high sensitivity detection of breast cancer. Further validation is required before array-based technology is used routinely for early detection of breast cancer.Kenny HA, 2008, J CLIN INVEST, V118, P1367, DOI 10.1172/JCI33775Shah FD, 2008, INTEGR CANCER THER, V7, P33, DOI 10.1177/1534735407313883Carlsson A, 2008, EUR J CANCER, V44, P472, DOI 10.1016/j.ejca.2007.11.025Nolen BM, 2008, BREAST CANCER RES, V10, DOI 10.1186/bcr2096Brogren H, 2008, THROMB RES, V122, P271, DOI 10.1016/j.thromres.2008.04.008Varki A, 2007, BLOOD, V110, P1723, DOI 10.1182/blood-2006-10-053736Madsen CD, 2007, J CELL BIOL, V177, P927, DOI 10.1083/jcb.200612058Levenson VV, 2007, BBA-GEN SUBJECTS, V1770, P847, DOI 10.1016/j.bbagen.2007.01.017VAZQUEZMARTIN A, 2007, EUR J CANCER, V43, P1117GARCIA M, 2007, GLOBAL CANC FACTS FIMoore LE, 2006, CANCER EPIDEM BIOMAR, V15, P1641, DOI 10.1158/1055-9965.EPI-05-0980Borrebaeck CAK, 2006, EXPERT OPIN BIOL TH, V6, P833, DOI 10.1517/14712598.6.8.833Zannis VI, 2006, J MOL MED-JMM, V84, P276, DOI 10.1007/s00109-005-0030-4Jemal A, 2006, CA-CANCER J CLIN, V56, P106Silva HC, 2006, NEOPLASMA, V53, P538Chahed K, 2005, INT J ONCOL, V27, P1425Jain KK, 2005, EXPERT OPIN PHARMACO, V6, P1463, DOI 10.1517/14656566.6.9.1463Abe O, 2005, LANCET, V365, P1687Paradis V, 2005, HEPATOLOGY, V41, P40, DOI 10.1002/hep.20505Molina R, 2005, TUMOR BIOL, V26, P281, DOI 10.1159/000089260Furberg AS, 2005, CANCER EPIDEM BIOMAR, V14, P33Benoy IH, 2004, CLIN CANCER RES, V10, P7157Song JS, 2004, BLOOD, V104, P2065, DOI 10.1182/blood-2004-02-0449Schairer C, 2004, J NATL CANCER I, V96, P1311, DOI 10.1093/jnci/djh253Hellman K, 2004, BRIT J CANCER, V91, P319, DOI 10.1038/sj.bjc.6601944Roselli M, 2004, CLIN CANCER RES, V10, P610Zhou AW, 2003, NAT STRUCT BIOL, V10, P541, DOI 10.1038/nsb943Hapke S, 2003, BIOL CHEM, V384, P1073Miller JC, 2003, PROTEOMICS, V3, P56Amirkhosravi A, 2002, BLOOD COAGUL FIBRIN, V13, P505Bonello N, 2002, HUM REPROD, V17, P2272Li JN, 2002, CLIN CHEM, V48, P1296Louhimo J, 2002, ANTICANCER RES, V22, P1759Knezevic V, 2001, PROTEOMICS, V1, P1271Di Micco P, 2001, DIGEST LIVER DIS, V33, P546Ferrigno D, 2001, EUR RESPIR J, V17, P667Webb DJ, 2001, J CELL BIOL, V152, P741Gion M, 2001, EUR J CANCER, V37, P355Schonbeck U, 2001, CELL MOL LIFE SCI, V58, P4Blackwell K, 2000, J CLIN ONCOL, V18, P600Carriero MV, 1999, CANCER RES, V59, P5307Antman K, 1999, JAMA-J AM MED ASSOC, V281, P1470Loskutoff DJ, 1999, APMIS, V107, P54Molina R, 1998, BREAST CANCER RES TR, V51, P109Bajou K, 1998, NAT MED, V4, P923Chan DW, 1997, J CLIN ONCOL, V15, P2322Chu KC, 1996, J NATL CANCER I, V88, P1571vanDalen A, 1996, ANTICANCER RES, V16, P2345Yamamoto N, 1996, CANCER RES, V56, P2827KOCH AE, 1995, NATURE, V376, P517HADDAD JG, 1995, J STEROID BIOCHEM, V53, P579FOEKENS JA, 1994, J CLIN ONCOL, V12, P1648GEARING AJH, 1993, IMMUNOL TODAY, V14, P506HUTCHENS TW, 1993, RAPID COMMUN MASS SP, V7, P576DECLERCK PJ, 1992, J BIOL CHEM, V267, P11693GABRIJELCIC D, 1992, AGENTS ACTIONS S, V38, P350BIEGLMAYER C, 1991, TUMOR BIOL, V12, P138DNISTRIAN AM, 1991, TUMOR BIOL, V12, P82VANDALEN A, 1990, TUMOR BIOL, V11, P189KARAS M, 1988, ANAL CHEM, V60, P2299, DOI 10.1021/ac00171a028LERNER WA, 1983, INT J CANCER, V31, P463WESTGARD JO, 1981, CLIN CHEM, V27, P493TROUSSEAU A, 1865, CLIN MED HOTEL DIEU, V3, P654*R PROJ, R PROJ STAT COMP1

APOE ε4 lowers age at onset and is a high risk factor for Alzheimer's disease; A case control study from central Norway

<p>Abstract</p> <p>Background</p> <p>The objective of this study was to analyze factors influencing the risk and timing of Alzheimer's disease (AD) in central Norway. The <it>APOE </it>ε4 allele is the only consistently identified risk factor for late onset Alzheimer's disease (LOAD). We have described the allele frequencies of the apolipoprotein E gene (<it>APOE</it>) in a large population of patients with AD compared to the frequencies in a cognitively-normal control group, and estimated the effect of the <it>APOE </it>ε4 allele on the risk and the age at onset of AD in this population.</p> <p>Methods</p> <p>376 patients diagnosed with AD and 561 cognitively-normal control individuals with no known first degree relatives with dementia were genotyped for the <it>APOE </it>alleles. Allele frequencies and genotypes in patients and control individuals were compared. Odds Ratio for developing AD in different genotypes was calculated.</p> <p>Results</p> <p>Odds Ratio (OR) for developing AD was significantly increased in carriers of the <it>APOE </it>ε4 allele compared to individuals with the <it>APOE </it>ε3/ε3 genotype. Individuals carrying <it>APOE </it>ε4/ε4 had OR of 12.9 for developing AD, while carriers of <it>APOE </it>ε2/ε4 and <it>APOE </it>ε3/ε4 had OR of 3.2 and 4.2 respectively. The effect of the <it>APOE </it>ε4 allele was weaker with increasing age. Carrying the <it>APOE </it>ε2 allele showed no significant protective effect against AD and did not influence age at onset of the disease. Onset in LOAD patients was significantly reduced in a dose dependent manner from 78.4 years in patients without the <it>APOE </it>ε4 allele, to 75.3 in carriers of one <it>APOE </it>ε4 allele and 72.9 in carriers of two <it>APOE </it>ε4 alleles. Age at onset in early onset AD (EOAD) was not influenced by <it>APOE </it>ε4 alleles.</p> <p>Conclusion</p> <p><it>APOE </it>ε4 is a very strong risk factor for AD in the population of central Norway, and lowers age at onset of LOAD significantly.</p

LDLR Expression and Localization Are Altered in Mouse and Human Cell Culture Models of Alzheimer's Disease

Alzheimer's disease (AD) is a chronic neurodegenerative disorder and the most common form of dementia. The major molecular risk factor for late-onset AD is expression of the ε-4 allele of apolipoprotein E (apoE), the major cholesterol transporter in the brain. The low-density lipoprotein receptor (LDLR) has the highest affinity for apoE and plays an important role in brain cholesterol metabolism.Using RT-PCR and western blotting techniques we found that over-expression of APP caused increases in both LDLR mRNA and protein levels in APP transfected H4 neuroglioma cells compared to H4 controls. Furthermore, immunohistochemical experiments showed aberrant localization of LDLR in H4-APP neuroglioma cells, Aβ-treated primary neurons, and in the PSAPP transgenic mouse model of AD. Finally, immunofluorescent staining of LDLR and of γ- and α-tubulin showed a change in LDLR localization preferentially away from the plasma membrane that was paralleled by and likely the result of a disruption of the microtubule-organizing center and associated microtubule network.These data suggest that increased APP expression and Aβ exposure alters microtubule function, leading to reduced transport of LDLR to the plasma membrane. Consequent deleterious effects on apoE uptake and function will have implications for AD pathogenesis and/or progression

Association of APOE polymorphism with chronic kidney disease in a nationally representative sample: a Third National Health and Nutrition Examination Survey (NHANES III) Genetic Study

<p>Abstract</p> <p>Background</p> <p>Apolipoprotein E polymorphisms (<it>APOE</it>) have been associated with lowered glomerular filtration rate (GFR) and chronic kidney disease (CKD) with e2 allele conferring risk and e4 providing protection. However, few data are available in non-European ethnic groups or in a population-based cohort.</p> <p>Methods</p> <p>The authors analyzed 5,583 individuals from the Third National Health and Nutrition Examination Survey (NHANES III) to determine association with estimated GFR by the Modification of Diet in Renal Disease (MDRD) equation and low-GFR cases. Low-GFR cases were defined as GFR <75 ml/min/1.73 m²; additionally, GFR was analyzed continuously.</p> <p>Results</p> <p>In univariate analysis, the e4 allele was negatively associated with low-GFR cases in non-Hispanic whites, odds ratio (OR): 0.76, 95% confidence interval (CI): 0.60, 0.97. In whites, there was a significant association between increasing <it>APOE </it>score (indicating greater number of e2 alleles) and higher prevalence of low-GFR cases (OR: 1.21, 95%CI: 1.01, 1.45). Analysis of continuous GFR in whites found the e4 allele was associated with higher levels of continuous GFR (β-coefficient: 2.57 ml/min/1.73 m², 95%CI: 0.005, 5.14); in non-Hispanic blacks the e2 allele was associated with lower levels of continuous GFR (β-coefficient: -3.73 ml/min/1.73 m², 95%CI: -6.61, -0.84). <it>APOE </it>e2 and e4 alleles were rare and not associated with low-GFR cases or continuous GFR in Mexican Americans.</p> <p>Conclusion</p> <p>In conclusion, the authors observed a weak association between the <it>APOE </it>e4 allele and low-GFR cases and continuous GFR in non-Hispanic whites, and the <it>APOE </it>e2 allele and continuous GFR in non-Hispanic blacks, but found no association with either measure of kidney function in Mexican Americans. Larger studies including multiethnic groups are needed to determine the significance of this association.</p