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1.
Eur Heart J ; 2024 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-39212219

RESUMO

BACKGROUND AND AIMS: INTERASPIRE is an international study of coronary heart disease (CHD) patients, designed to measure if guideline standards for secondary prevention and cardiac rehabilitation are being achieved in a timely manner. METHODS: Between 2020-2023, adults hospitalized in the preceding 6-24 months with incident or recurrent CHD were sampled in 14 countries from all 6 World Health Organization regions and invited for a standardized interview and examination. Direct age and sex standardization was used for country-level prevalence estimation. RESULTS: Overall, 4548 (21.1% female) CHD patients were interviewed a median of 1.05 (interquartile range 0.76-1.45) years after index hospitalization. Among all participants, 24% were obese (40% centrally). Only 38.5% achieved a blood pressure (BP) <130/80 mmHg and 19.2% a low-density lipoprotein cholesterol (LDL-C) of <1.4 mmol/l. Of those smoking at hospitalization, 48% persisted at interview. Of those with known diabetes, 56% achieved glycated hemoglobin (HbA1c) of <7.0%. A further 9.8% had undetected diabetes and 26.9% impaired glucose tolerance. Females were less likely to achieve targets: BP (females 37.4% males 38.6%), LDL-C (females 13.7% males 18.6%) and HbA1c in diabetes (females 47.7% males 57.5%). Overall, just 9.0% (inter-country range 3.8%-20.0%) reported attending cardiac rehabilitation and 1.0% (inter-country range 0.0%-2.4%) achieved the study definition of optimal guideline adherence. CONCLUSIONS: INTERASPIRE demonstrates inadequate and heterogeneous international implementation of guideline standards for secondary prevention in the first year after CHD hospitalization, with geographic and sex disparity. Investment aimed at reducing between-country and between-individual variability in secondary prevention will promote equity in global efforts to reduce the burden of CHD.

2.
Liver Int ; 43(10): 2107-2115, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37485795

RESUMO

BACKGROUND AND AIMS: Effective and feasible population screening strategies are needed for the early detection of individuals at high risk of future severe liver-related outcomes. We evaluated the predictive performance of the combination of liver fibrosis assessment, phenotype profile, and genetic risk. METHODS: Data from 5795 adults attending the Finnish Health 2000 Survey were linked with healthcare registers for liver-related outcomes (hospitalization, hepatocellular cancer, and death). Fibrosis was assessed using the enhanced liver fibrosis (ELF) test, phenotype profile by the chronic liver disease (CLivD) risk score, and genetic risk by a validated Polygenic Risk Score (PRS-5). Predictive performance was assessed by competing-risk analyses. RESULTS: During a median 13-year follow-up, 64 liver-related outcome events were recorded. ELF, CLivD score, and PRS-5 were independently associated with liver-related outcomes. The absolute 10-year risk of liver-related outcomes at an ELF value of 11.3 ranged from 0.3% to 33% depending on the CLivD score. The CLivD score added 51% of new predictive information to the ELF test and improved areas under the curve (AUCs) from 0.91, 0.81, and 0.71 for ELF alone to 0.95, 0.85, and 0.80, respectively, for ELF combined with the CLivD score at 1, 5, and 10 years. The greatest improvement was for 10-year predictions (delta-AUC 0.097, p < .0001). Adding PRS-5 did not significantly increase predictive performance. Findings were consistent in individuals with obesity, diabetes, or alcohol risk use, and regardless of whether gamma-glutamyltransferase was used in the CLivD score. CONCLUSION: A combination of ELF and CLivD score predicts liver-related outcomes significantly better than the ELF test alone.


Assuntos
Cirrose Hepática , Hepatopatias , Adulto , Humanos , Biomarcadores , Cirrose Hepática/diagnóstico , Cirrose Hepática/patologia , Fígado/patologia , Hepatopatias/patologia , Testes de Função Hepática
3.
JHEP Rep ; 5(7): 100765, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37333973

RESUMO

Background & Aims: The Enhanced Liver Fibrosis® (ELF) test exhibits good discriminative performance in detecting advanced liver fibrosis and in predicting liver-related outcomes in patients with specific liver diseases, but large population-based studies are missing. We analysed the predictive performance of the ELF test in a general population cohort. Methods: Data were sourced from the Health 2000 study, a Finnish population-based health examination survey conducted in 2000-2001. Subjects with baseline liver disease were excluded. The ELF test was performed on blood samples collected at baseline. Data were linked with national healthcare registers for liver-related outcomes (hospitalisation, cancer, and death). Results: The cohort comprised 6,040 individuals (mean age 52.7. 45.6% men) with 67 liver-related outcomes during a median 13.1-year follow-up. ELF predicted liver outcomes (unadjusted hazards ratio 2.70, 95% CI 2.16-3.38). with 5- and 10-year AUCs of 0.81 (95% CI 0.71-0.91) and 0.71 (95% CI 0.63-0.79) by competing-risk methodology. The 10-year risks for liver outcomes increased from 0.5% at ELF <9.8 to 7.1% at ELF ≥11.3, being higher among men than women at any given ELF level. Among individuals with body mass index ≥30 kg/m2, diabetes, or alanine aminotransferase >40 U/L. Five-year AUCs for ELF were 0.85, 0.87, and 0.88, respectively. The predictive ability of the ELF test decreased with time: the 10-year AUCs were 0.78, 0.69, and 0.82, respectively. Conclusions: The ELF test shows good discriminative performance in predicting liver-related outcomes in a large general population cohort and appears particularly useful for predicting 5-year outcomes in persons with risk factors. Impact and implications: The Enhanced Liver Fibrosis test exhibits good performance for predicting liver-related outcomes (hospitalisation, liver cancer, or liver-related death) in the general population, especially in those with risk factors.

4.
J Cell Physiol ; 234(4): 3744-3761, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30146765

RESUMO

Hepatocyte-like cells (HLCs) differentiated from human-induced pluripotent stem cells offer an alternative platform to primary human hepatocytes (PHHs) for studying the lipid metabolism of the liver. However, despite their great potential, the lipid profile of HLCs has not yet been characterized. Here, we comprehensively studied the lipid profile and fatty acid (FA) metabolism of HLCs and compared them with the current standard hepatocyte models: HepG2 cells and PHHs. We differentiated HLCs by five commonly used methods from three cell lines and thoroughly characterized them by gene and protein expression. HLCs generated by each method were assessed for their functionality and the ability to synthesize, elongate, and desaturate FAs. In addition, lipid and FA profiles of HLCs were investigated by both mass spectrometry and gas chromatography and then compared with the profiles of PHHs and HepG2 cells. HLCs resembled PHHs by expressing hepatic markers: secreting albumin, lipoprotein particles, and urea, and demonstrating similarities in their lipid and FA profile. Unlike HepG2 cells, HLCs contained low levels of lysophospholipids similar to the content of PHHs. Furthermore, HLCs were able to efficiently use the exogenous FAs available in their medium and simultaneously modify simple lipids into more complex ones to fulfill their needs. In addition, we propose that increasing the polyunsaturated FA supply of the culture medium may positively affect the lipid profile and functionality of HLCs. In conclusion, our data showed that HLCs provide a functional and relevant model to investigate human lipid homeostasis at both molecular and cellular levels.


Assuntos
Diferenciação Celular , Hepatócitos/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Metabolismo dos Lipídeos , Forma Celular , Cromatografia Gasosa , Ácidos Graxos/metabolismo , Regulação da Expressão Gênica , Células Hep G2 , Humanos , Metabolismo dos Lipídeos/genética , Lipidômica/métodos , Lisofosfolipídeos/metabolismo , Espectrometria de Massas , Fenótipo , Cultura Primária de Células
5.
Int J Mol Sci ; 17(9)2016 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-27657052

RESUMO

Smoking is a major risk factor for several diseases including chronic obstructive pulmonary disease (COPD). To better understand the systemic effects of cigarette smoke exposure and mild to moderate COPD-and to support future biomarker development-we profiled the serum lipidomes of healthy smokers, smokers with mild to moderate COPD (GOLD stages 1 and 2), former smokers, and never-smokers (n = 40 per group) (ClinicalTrials.gov registration: NCT01780298). Serum lipidome profiling was conducted with untargeted and targeted mass spectrometry-based lipidomics. Guided by weighted lipid co-expression network analysis, we identified three main trends comparing smokers, especially those with COPD, with non-smokers: a general increase in glycero(phospho)lipids, including triglycerols; changes in fatty acid desaturation (decrease in ω-3 polyunsaturated fatty acids, and an increase in monounsaturated fatty acids); and an imbalance in eicosanoids (increase in 11,12- and 14,15-DHETs (dihydroxyeicosatrienoic acids), and a decrease in 9- and 13-HODEs (hydroxyoctadecadienoic acids)). The lipidome profiles supported classification of study subjects as smokers or non-smokers, but were not sufficient to distinguish between smokers with and without COPD. Overall, our study yielded further insights into the complex interplay between smoke exposure, lung disease, and systemic alterations in serum lipid profiles.

6.
Sci Data ; 3: 150077, 2016 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-26731301

RESUMO

Smoking of combustible cigarettes has a major impact on human health. Using a systems toxicology approach in a model of chronic obstructive pulmonary disease (C57BL/6 mice), we assessed the health consequences in mice of an aerosol derived from a prototype modified risk tobacco product (pMRTP) as compared to conventional cigarettes. We investigated physiological and histological endpoints in parallel with transcriptomics, lipidomics, and proteomics profiles in mice exposed to a reference cigarette (3R4F) smoke or a pMRTP aerosol for up to 7 months. We also included a cessation group and a switching-to-pMRTP group (after 2 months of 3R4F exposure) in addition to the control (fresh air-exposed) group, to understand the potential risk reduction of switching to pMRTP compared with continuous 3R4F exposure and cessation. The present manuscript describes the study design, setup, and implementation, as well as the generation, processing, and quality control analysis of the toxicology and 'omics' datasets that are accessible in public repositories for further analyses.


Assuntos
Doença Pulmonar Obstrutiva Crônica , Fumar/efeitos adversos , Animais , Peso Corporal , Feminino , Metabolismo dos Lipídeos , Pulmão/metabolismo , Pulmão/fisiopatologia , Camundongos , Camundongos Endogâmicos C57BL , Análise Serial de Proteínas , Proteômica , Doença Pulmonar Obstrutiva Crônica/etiologia , Doença Pulmonar Obstrutiva Crônica/metabolismo , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Lesão por Inalação de Fumaça/etiologia , Lesão por Inalação de Fumaça/metabolismo , Lesão por Inalação de Fumaça/fisiopatologia
7.
Toxicol Sci ; 149(2): 441-57, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26582801

RESUMO

The impact of cigarette smoke (CS), a major cause of lung diseases, on the composition and metabolism of lung lipids is incompletely understood. Here, we integrated quantitative lipidomics and proteomics to investigate exposure effects on lung lipid metabolism in a C57BL/6 and an Apolipoprotein E-deficient (Apoe(-/-)) mouse study. In these studies, mice were exposed to high concentrations of 3R4F reference CS, aerosol from potential modified risk tobacco products (MRTPs) or filtered air (Sham) for up to 8 months. The 2 assessed MRTPs, the prototypical MRTP for C57BL/6 mice and the Tobacco Heating System 2.2 for Apoe(-/-) mice, utilize "heat-not-burn" technologies and were each matched in nicotine concentrations to the 3R4F CS. After 2 months of CS exposure, some groups were either switched to the MRTP or underwent cessation. In both mouse strains, CS strongly affected several categories of lung lipids and lipid-related proteins. Candidate surfactant lipids, surfactant proteins, and surfactant metabolizing proteins were increased. Inflammatory eicosanoids, their metabolic enzymes, and several ceramide classes were elevated. Overall, CS induced a coordinated lipid response controlled by transcription regulators such as SREBP proteins and supported by other metabolic adaptations. In contrast, most of these changes were absent in the mice exposed to the potential MRTPs, in the cessation group, and the switching group. Our findings demonstrate the complex biological response of the lungs to CS exposure and support the benefits of cessation or switching to a heat-not-burn product using a design such as those employed in this study.


Assuntos
Apolipoproteínas E/fisiologia , Metabolismo dos Lipídeos , Pulmão/metabolismo , Nicotiana/toxicidade , Fumaça/efeitos adversos , Animais , Eicosanoides/metabolismo , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Estresse Oxidativo , Proteoma , Esfingolipídeos/metabolismo
8.
Cell Rep ; 13(9): 2000-13, 2015 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-26628366

RESUMO

Cold exposure greatly alters brown adipose tissue (BAT) gene expression and metabolism to increase thermogenic capacity. Here, we used RNA sequencing and mass-spectrometry-based lipidomics to provide a comprehensive resource describing the molecular signature of cold adaptation at the level of the transcriptome and lipidome. We show that short-term (3-day) cold exposure leads to a robust increase in expression of several brown adipocyte genes related to thermogenesis as well as the gene encoding the hormone irisin. However, pathway analysis shows that the most significantly induced genes are those involved in glycerophospholipid synthesis and fatty acid elongation. This is accompanied by significant changes in the acyl chain composition of triacylglycerols (TAGs) as well as subspecies-selective changes of acyl chains in glycerophospholipids. These results indicate that cold adaptation of BAT is associated with significant and highly species-selective remodeling of both TAGs and glycerophospholipids.


Assuntos
Tecido Adiposo Marrom/metabolismo , Glicerofosfolipídeos/metabolismo , Animais , Análise por Conglomerados , Temperatura Baixa , Fibronectinas/metabolismo , Glutationa/metabolismo , Masculino , Espectrometria de Massas , Camundongos , Camundongos Endogâmicos C57BL , RNA/metabolismo , Análise de Sequência de RNA , Termogênese , Fatores de Tempo , Transcriptoma
9.
Atherosclerosis ; 243(2): 560-6, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26523994

RESUMO

BACKGROUND AND AIMS: Previous lipidomics analyses have demonstrated that several lipid molecules in plasma are associated with fatal outcome in patients with coronary artery disease (CAD). This study aims to investigate the associations of previously identified high risk lipid molecules in plasma with coronary plaque characteristics derived from intravascular ultrasound virtual histology (IVUS-VH) imaging, with coronary lipid core burden index (LCBI) on near-infrared spectroscopy (NIRS), and with one year cardiovascular outcome in patients with CAD. METHODS: Between 2008 and 2011, IVUS-VH imaging of a non-culprit coronary artery was performed in 581 patients who underwent coronary angiography for acute coronary syndrome (ACS) or stable CAD. NIRS imaging was additionally performed in 191 patients. Plasma concentrations of molecular lipids were measured with mass spectrometry. RESULTS: Several cholesteryl ester, ceramide and lactosylceramide species and ceramide ratios were associated with vulnerable plaque characteristics on IVUS-VH and NIRS imaging and with 1-year major adverse cardiac events (MACE, defined as all-cause mortality, ACS and unplanned coronary revascularization). In particular, ceramide d18:1/16:0 was consistently associated with higher necrotic core fraction on IVUS-VH (p = 0.001), higher LCBI (p = 0.024) on NIRS and higher MACE rate (adjusted HR 1.79 per standard deviation increase in log-transformed lipid concentration, 95%CI 1.24-2.59, p = 0.002). CONCLUSION: Several molecular lipid species, and particularly ceramide(d18:1/16:0), are associated with the fraction of necrotic core tissue and lipid core burden in coronary atherosclerosis, and are predictive for 1-year clinical outcome after coronary angiography. These molecular lipids may improve risk stratification in CAD and may also be interesting therapeutic targets for the treatment of atherosclerotic disease.


Assuntos
Síndrome Coronariana Aguda/sangue , Síndrome Coronariana Aguda/diagnóstico por imagem , Doença da Artéria Coronariana/sangue , Doença da Artéria Coronariana/diagnóstico por imagem , Vasos Coronários/diagnóstico por imagem , Vasos Coronários/metabolismo , Lipídeos/sangue , Placa Aterosclerótica , Ultrassonografia de Intervenção , Síndrome Coronariana Aguda/mortalidade , Síndrome Coronariana Aguda/terapia , Idoso , Biomarcadores/sangue , Angiografia Coronária , Doença da Artéria Coronariana/mortalidade , Doença da Artéria Coronariana/terapia , Progressão da Doença , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Espectrometria de Massas , Pessoa de Meia-Idade , Revascularização Miocárdica , Necrose , Países Baixos , Valor Preditivo dos Testes , Modelos de Riscos Proporcionais , Fatores de Risco , Ruptura Espontânea , Espectroscopia de Luz Próxima ao Infravermelho
10.
Lipids Health Dis ; 14: 88, 2015 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-26260413

RESUMO

BACKGROUND: Marine food is an important source of omega-3 fatty acids with beneficial health effects. Oils from marine organisms have different fatty acid composition and differ in their molecular composition. Fish oil (FO) has a high content of eicosapentaenoic and docosahexaenoic acids mainly esterified to triacylglycerols, while in krill oil (KO) these fatty acids are mainly esterified to phospholipids. The aim was to study the effects of these oils on the lipid content and fatty acid distribution in the various lipid classes in liver and brain of mice. METHODS: Mice were fed either a high-fat diet (HF), a HF diet supplemented with FO or with KO (n = 6). After six weeks of feeding, liver and brain lipid extracts were analysed using a shotgun and TAG lipidomics approach. Student t-test was performed after log-transformation to compare differences between study groups. RESULTS: Six weeks of feeding resulted in significant changes in the relative abundance of many lipid classes compared to control mice. In both FO and KO fed mice, the triacylglycerol content in the liver was more than doubled. The fatty acid distribution was affected by the oils in both liver and brain with a decrease in the abundance of 18:2 and 20:4, and an increase in 20:5 and 22:6 in both study groups. 18:2 decreased in all lipid classes in the FO group but with only minor changes in the KO group. Differences between the feeding groups were particularly evident in some of the minor lipid classes that are associated with inflammation and insulin resistance. Ceramides and diacylglycerols were decreased and cholesteryl esters increased in the liver of the KO group, while plasmalogens were decreased in the FO group. In the brain, diacylglycerols were decreased, more by KO than FO, while ceramides and lactosylceramides were increased, more by FO than KO. CONCLUSION: The changes in the hepatic sphingolipids and 20:4 fatty acid levels were greater in the KO compared to the FO fed mice, and are consistent with a hypothesis that krill oil will have a stronger anti-inflammatory action and enhances insulin sensitivity more potently than fish oil.


Assuntos
Encéfalo/metabolismo , Euphausiacea/química , Comportamento Alimentar , Óleos de Peixe/farmacologia , Lipídeos/química , Fígado/metabolismo , Metaboloma/efeitos dos fármacos , Animais , Peso Corporal/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Ácidos Graxos/metabolismo , Fígado/efeitos dos fármacos , Camundongos
11.
Exp Cell Res ; 331(2): 278-91, 2015 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-25447204

RESUMO

ORP3 is an R-Ras interacting oxysterol-binding protein homolog that regulates cell adhesion and is overexpressed in several cancers. We investigated here a novel function of ORP3 dependent on its targeting to both the endoplasmic reticulum (ER) and the plasma membrane (PM). Using biochemical and cell imaging techniques we demonstrate the mechanistic requirements for the subcellular targeting and function of ORP3 in control of R-Ras activity. We show that hyperphosphorylated ORP3 (ORP3-P) selectively interacts with the ER membrane protein VAPA, and ORP3-VAPA complexes are targeted to PM sites via the ORP3 pleckstrin homology (PH) domain. A novel FFAT (two phenylalanines in an acidic tract)-like motif was identified in ORP3; only disruption of both the FFAT-like and canonical FFAT motif abolished the phorbol-12-myristate-13-acetate (PMA) stimulated interaction of ORP3-P with VAPA. Co-expression of ORP3 and VAPA induced R-Ras activation, dependent on the interactions of ORP3 with VAPA and the PM. Consistently, downstream AktS473 phosphorylation and ß1-integrin activity were enhanced by ORP3-VAPA. To conclude, phosphorylation of ORP3 controls its association with VAPA. Furthermore, we present evidence that ORP3-VAPA complexes stimulate R-Ras signaling.


Assuntos
Proteínas de Transporte/metabolismo , Membrana Celular/metabolismo , Retículo Endoplasmático/metabolismo , Proteínas de Transporte Vesicular/metabolismo , Proteínas ras/metabolismo , Motivos de Aminoácidos , Proteínas de Transporte/biossíntese , Linhagem Celular Tumoral , Ativação Enzimática , Proteínas de Ligação a Ácido Graxo , Células HEK293 , Humanos , Integrina beta1/metabolismo , Fosforilação , Ligação Proteica , Estrutura Terciária de Proteína , Alinhamento de Sequência , Acetato de Tetradecanoilforbol/análogos & derivados , Acetato de Tetradecanoilforbol/farmacologia , Proteínas de Transporte Vesicular/biossíntese
12.
Biochimie ; 95(3): 538-47, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22609461

RESUMO

Oxysterol-binding protein homologs (ORPs) are implicated in lipid metabolism, vesicle transport and cell signaling. In this study we generated RAW264.7 cells with ORP1L, ORP3, or ORP8 silenced using shRNA lentiviruses. The lipidome of the cells under basal serum-free culture conditions or as treated with oxidized LDL (oxLDL), enzymatically modified LDL (E-LDL), or lipopolysaccharide (LPS) was analyzed by mass spectrometry. Reduction in each ORP resulted in distinct and complex effects on macrophage lipidome. Under basal conditions, ORP1L silencing had strongest effects on phosphatidylinositols (PI, increase), free cholesterol (FC, increase), and cholesteryl esters (CE, increase). ORP3 silencing affected most the glucosyl ceramides (GluCer, decrease) and PE-plasmalogens (PE-pl, decrease), while ORP8 silencing increased FC and CE, and decreased GluCer and PE-pl. Upon LPS treatment, the ORP effects were modified: under these conditions ORP1L silencing caused increase of Cer, ORP3 silencing decrease of PI, and ORP8 silencing decrease of PI and increase of PE, not detectable under basal conditions. The lipid species data were subjected to multivariate statistical analysis of principal components, revealing numerous specific alterations upon ORP silencing. The cells cultured in basal conditions or treated with LPS showed qualitatively different responses. However, in LPS-stimulated cells silencing of any of the three ORPs decreased the relative amount of arachidonic acid-containing PI species, increased the corresponding PE species, and favored 16-carbon sphingomyelin (SM) species at the expense of the 24-carbon ones. As a conclusion, the present study reveals the distinct and sophisticated roles of different ORP proteins as regulators of macrophage lipid composition, with implications for inflammatory signaling.


Assuntos
Inativação Gênica , Metabolismo dos Lipídeos/genética , Macrófagos/metabolismo , Receptores de Esteroides/deficiência , Receptores de Esteroides/genética , Animais , Aterosclerose/metabolismo , Linhagem Celular , Lentivirus/genética , Metabolismo dos Lipídeos/efeitos dos fármacos , Lipopolissacarídeos/farmacologia , Macrófagos/efeitos dos fármacos , Camundongos , RNA Interferente Pequeno/genética
13.
Exp Cell Res ; 318(15): 1933-45, 2012 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-22683860

RESUMO

ORP8 is an oxysterol/cholesterol binding protein anchored to the endoplasmic reticulum and the nuclear envelope, and is abundantly expressed in the macrophage. We created and characterized mouse RAW264.7 macrophages with ORP8 stably silenced using shRNA lentiviruses. A microarray transcriptome and gene ontology pathway analysis revealed significant alterations in several nuclear pathways and ones associated with centrosome and microtubule organization. ORP8 knockdown resulted in increased expression and altered subcellular distribution of an interaction partner of ORP8, nucleoporin NUP62, with an intranuclear localization aspect and association with cytoplasmic vesicular structures and lamellipodial edges of the cells. Moreover, ORP8 silenced cells displayed enhanced migration, and a more pronounced microtubule cytoskeleton than controls expressing a non-targeting shRNA. ORP8 was shown to compete with Exo70 for interaction with NUP62, and NUP62 knockdown abolished the migration enhancement of ORP8-silenced cells, suggesting that the endogenous ORP8 suppresses migration via binding to NUP62. As a conclusion, the present study reveals new, unexpected aspects of ORP8 function in macrophages not directly involving lipid metabolism, but rather associated with nuclear functions, microtubule organization, and migration capacity.


Assuntos
Macrófagos/fisiologia , Glicoproteínas de Membrana/metabolismo , Complexo de Proteínas Formadoras de Poros Nucleares/metabolismo , Receptores de Esteroides/antagonistas & inibidores , Receptores de Esteroides/fisiologia , Animais , Sequência de Bases , Ligação Competitiva , Ciclo Celular , Linhagem Celular , Movimento Celular , Núcleo Celular/metabolismo , Proliferação de Células , Primers do DNA/genética , Técnicas de Silenciamento de Genes , Macrófagos/citologia , Glicoproteínas de Membrana/antagonistas & inibidores , Glicoproteínas de Membrana/genética , Camundongos , Microtúbulos/metabolismo , Complexo de Proteínas Formadoras de Poros Nucleares/antagonistas & inibidores , Complexo de Proteínas Formadoras de Poros Nucleares/genética , Análise de Sequência com Séries de Oligonucleotídeos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/genética , Receptores de Esteroides/genética , Transcriptoma , Proteínas de Transporte Vesicular/metabolismo
14.
PLoS One ; 6(6): e21078, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21698267

RESUMO

We earlier identified OSBP-related protein 8 (ORP8) as an endoplasmic reticulum oxysterol-binding protein implicated in cellular lipid homeostasis. We now investigated its action in hepatic cells in vivo and in vitro. Adenoviral overexpression of ORP8 in mouse liver induced a decrease of cholesterol, phospholipids, and triglycerides in serum (-34%, -26%, -37%, respectively) and liver tissue (-40%, -12%, -24%), coinciding with reduction of nuclear (n)SREBP-1 and -2 and mRNA levels of their target genes. Consistently, excess ORP8 reduced nSREBPs in HuH7 cells, and ORP8 overexpression or silencing by RNA interference moderately suppressed or induced the expression of SREBP-1 and SREBP-2 target genes, respectively. In accordance, cholesterol biosynthesis was reduced by ORP8 overexpression and enhanced by ORP8 silencing in [(3)H]acetate pulse-labeling experiments. ORP8, previously shown to bind 25-hydroxycholesterol, was now shown to bind also cholesterol in vitro. Yeast two-hybrid, bimolecular fluorescence complementation (BiFC), and co-immunoprecipitation analyses revealed the nuclear pore component Nup62 as an interaction partner of ORP8. Co-localization of ORP8 and Nup62 at the nuclear envelope was demonstrated by BiFC and confocal immunofluorescence microscopy. Furthermore, the impact of overexpressed ORP8 on nSREBPs and their target mRNAs was inhibited in cells depleted of Nup62. Our results reveal that ORP8 has the capacity to modulate lipid homeostasis and SREBP activity, probably through an indirect mechanism, and provide clues of an entirely new mode of ORP action.


Assuntos
Metabolismo dos Lipídeos , Lipídeos/sangue , Fígado/metabolismo , Glicoproteínas de Membrana/metabolismo , Complexo de Proteínas Formadoras de Poros Nucleares/metabolismo , Receptores de Esteroides/fisiologia , Animais , Sequência de Bases , Linhagem Celular Tumoral , Primers do DNA , Feminino , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Microscopia de Fluorescência , Ligação Proteica , Receptores de Esteroides/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Técnicas do Sistema de Duplo-Híbrido
15.
Cell Mol Life Sci ; 68(3): 537-51, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20690035

RESUMO

ORP1L is an oxysterol binding homologue that regulates late endosome (LE) positioning. We show that ORP1L binds several oxysterols and cholesterol, and characterize a mutant, ORP1L Δ560-563, defective in oxysterol binding. While wild-type ORP1L clusters LE, ORP1L Δ560-563 induces LE scattering, which is reversed by disruption of the endoplasmic reticulum (ER) targeting FFAT motif, suggesting that it is due to enhanced LE-ER interactions. Endosome motility is reduced upon overexpression of ORP1L. Both wild-type ORP1L and the Δ560-563 mutant induce the recruitment of both dynactin and kinesin-2 on LE. Most of the LE decorated by overexpressed ORP1L fail to accept endocytosed dextran or EGF, and the transfected cells display defective degradation of internalized EGF. ORP1L silencing in macrophage foam cells enhances endosome motility and results in inhibition of [(3)H]cholesterol efflux to apolipoprotein A-I. These data demonstrate that LE motility and functions in both protein and lipid transport are regulated by ORP1L.


Assuntos
Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Endossomos/metabolismo , Esteróis/metabolismo , Animais , Apolipoproteína A-I/metabolismo , Proteínas de Transporte/análise , Linhagem Celular , Colesterol/metabolismo , Endocitose , Endossomos/ultraestrutura , Regulação da Expressão Gênica , Células HeLa , Humanos , Lisossomos/metabolismo , Macrófagos/metabolismo , Macrófagos/ultraestrutura , Camundongos , Modelos Moleculares , Proteínas Motores Moleculares/metabolismo , Mutação , Ligação Proteica , Receptores de Esteroides
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