RESUMEN

BACKGROUND: Spinal cord injury (SCI) is characterized by extensive demyelination and inflammatory responses. Facilitating the clearance of lipid droplets (LDs) within microglia contributes to creating a microenvironment that favors neural recovery and provides essential materials for subsequent remyelination. Therefore, investigating MicroRNAs (miRNAs) that regulate lipid homeostasis after SCI and elucidating their potential mechanisms in promoting LDs clearance in microglia have become focal points of SCI research. METHODS: We established a subacute C5 hemicontusion SCI model in mice and performed transcriptomic sequencing on the injury epicenter to identify differentially expressed genes and associated pathways. Confocal imaging was employed to observe LDs accumulation. Multi-omics analyses were conducted to identify differentially expressed mRNA and miRNA post-SCI. Pathway enrichment analysis and protein-protein interaction network construction were performed using bioinformatics methods, revealing miR-223-Abca1 as a crucial miRNA-mRNA pair in lipid metabolism regulation. BV2 microglia cell lines overexpressing miR-223 were engineered, and immunofluorescence staining, western blot, and other techniques were employed to assess LDs accumulation, relevant targets, and inflammatory factor expression, confirming its role in regulating lipid homeostasis in microglia. RESULTS: Histopathological results of our hemicontusion SCI model confirmed LDs aggregation at the injury epicenter, predominantly within microglia. Our transcriptomic analysis during the subacute phase of SCI in mice implicated ATP-binding cassette transporter A1 (Abca1) as a pivotal gene in lipid homeostasis, cholesterol efflux and microglial activation. Integrative mRNA-miRNA multi-omics analysis highlighted the crucial role of miR-223 in the neuroinflammation process following SCI, potentially through the regulation of lipid metabolism via Abca1. In vitro experiments using BV2 cells overexpressing miR-223 demonstrated that elevated levels of miR-223 enhance ABCA1 expression in myelin debris and LPS-induced BV2 cells. This promotes myelin debris degradation and LDs clearance, and induces a shift toward an anti-inflammatory M2 phenotype. CONCLUSIONS: In summary, our study unveils the critical regulatory role of miR-223 in lipid homeostasis following SCI. The mechanism by which this occurs involves the upregulation of ABCA1 expression, which facilitates LDs clearance and myelin debris degradation, consequently alleviating the lipid burden, and inhibiting inflammatory polarization of microglia. These findings suggest that strategies to enhance miR-223 expression and target ABCA1, thereby augmenting LDs clearance, may emerge as appealing new clinical targets for SCI treatment.

Asunto(s)

Transportador 1 de Casete de Unión a ATP , Gotas Lipídicas , Ratones Endogámicos C57BL , MicroARNs , Microglía , Traumatismos de la Médula Espinal , Regulación hacia Arriba , Traumatismos de la Médula Espinal/metabolismo , Traumatismos de la Médula Espinal/patología , MicroARNs/metabolismo , MicroARNs/genética , Microglía/metabolismo , Microglía/patología , Animales , Transportador 1 de Casete de Unión a ATP/metabolismo , Transportador 1 de Casete de Unión a ATP/genética , Gotas Lipídicas/metabolismo , Ratones , Línea Celular , Masculino , Metabolismo de los Lípidos/genética

RESUMEN

Cholesterol homeostasis is essential in normal physiology of all cells. One of several proteins involved in cholesterol homeostasis is the ATP-binding cassette transporter A1 (ABCA1), a transmembrane protein widely expressed in many tissues. One of its main functions is the efflux of intracellular free cholesterol and phospholipids across the plasma membrane to combine with apolipoproteins, mainly apolipoprotein A-I (Apo A-I), forming nascent high-density lipoprotein-cholesterol (HDL-C) particles, the first step of reverse cholesterol transport (RCT). In addition, ABCA1 regulates cholesterol and phospholipid content in the plasma membrane affecting lipid rafts, microparticle (MP) formation and cell signaling. Thus, it is not surprising that impaired ABCA1 function and altered cholesterol homeostasis may affect many different organs and is involved in the pathophysiology of a broad array of diseases. This review describes evidence obtained from animal models, human studies and genetic variation explaining how ABCA1 is involved in dyslipidemia, coronary heart disease (CHD), type 2 diabetes (T2D), thrombosis, neurological disorders, age-related macular degeneration (AMD), glaucoma, viral infections and in cancer progression.

Asunto(s)

Transportador 1 de Casete de Unión a ATP/metabolismo , Colesterol/metabolismo , Transportador 1 de Casete de Unión a ATP/deficiencia , Transportador 1 de Casete de Unión a ATP/genética , Envejecimiento/genética , Envejecimiento/metabolismo , Animales , Enfermedades Transmisibles/etiología , Enfermedad Coronaria/etiología , Diabetes Mellitus Tipo 2/etiología , Dislipidemias/etiología , Dislipidemias/metabolismo , Oftalmopatías/etiología , Variación Genética , Humanos , Resistencia a la Insulina , Lípidos/sangre , Hepatopatías/etiología , Malaria/etiología , MicroARNs/genética , Modelos Biológicos , Mutación , Neoplasias/etiología , Enfermedades del Sistema Nervioso/etiología , Enfermedad de Tangier/etiología

RESUMEN

ATP-binding cassette transporter A1 (ABCA1) is an essential regulator of intracellular cholesterol efflux. Secreted cholesterol binds to lipid-free apolipoprotein A-I (apoA-I) in peripheral blood to constitute high-density lipoprotein cholesterol (HDL) complexes. ABCA1 protein on the surface of macrophages acts as a crucial controller in preventing cholesterol accumulation. Importantly, ABCA1 is unstable and easily degraded via a series of biochemical activities, including but not limited to calpain-mediated and ubiquitin-proteasome system-mediated processes. How accelerated ABCA1 degradation impacts disordered lipid metabolism in macrophages and foam cell formation is unclear. N-methyl d-aspartate receptors (NMDARs) are ionotropic glutamate receptors with high calcium permeability. Calcium influx via NMDARs activates downstream signaling pathways. Over-activation of NMDARs stimulated by NMDA contributes to dysfunctional lipid metabolism in macrophages and foam cell formation via promotion of calpain-mediated ABCA1 proteolysis. However, increased NMDAR activity does not affect liver X receptor expression or ABCA1 mRNA levels. Following NMDA receptor silencing or calpain inhibition, NMDA treatment did not reduce ABCA1 protein levels, nor caused lipid accumulation in macrophages. In addition, NMDAR over-activation activates NF-κB signaling to promote IL-1ß and IL-6 macrophage marker expression. However, NMDAR silencing and calpain inhibition reduce inflammatory macrophage responses. In summary, our study suggests that NMDAR activation reduces surface ABCA1 protein, promotes lipid accumulation, and induces the production and secretion of many inflammatory mediators in macrophages, possibly through enhanced calpain-mediated ABCA1 protein degradation. Thus, the NMDAR receptor may be a novel pharmacologic target for atherosclerosis therapy.

Asunto(s)

Transportador 1 de Casete de Unión a ATP/genética , Aterosclerosis/genética , Células Espumosas/metabolismo , Receptores de N-Metil-D-Aspartato/genética , Apolipoproteína A-I/genética , Aterosclerosis/metabolismo , Aterosclerosis/patología , Transporte Biológico/genética , Calcio/metabolismo , Calpaína/antagonistas & inhibidores , HDL-Colesterol/genética , HDL-Colesterol/metabolismo , Regulación de la Expresión Génica/genética , Humanos , Metabolismo de los Lípidos/genética , Receptores X del Hígado/genética , Receptores X del Hígado/metabolismo , Macrófagos/metabolismo , N-Metilaspartato/genética , N-Metilaspartato/metabolismo , FN-kappa B/genética , Proteolisis , Receptores de N-Metil-D-Aspartato/metabolismo

RESUMEN

One of the most relevant drawbacks in medicine is the ability of drugs and/or imaging agents to reach cells. Nanotechnology opened new horizons in drug delivery, and silver nanoparticles (AgNPs) represent a promising delivery vehicle for their adjustable size and shape, high-density surface ligand attachment, etc. AgNPs cellular uptake involves different endocytosis mechanisms, including lipid raft-mediated endocytosis. Since static magnetic fields (SMFs) exposure induces plasma membrane perturbation, including the rearrangement of lipid rafts, we investigated whether SMF could increase the amount of AgNPs able to pass the peripheral blood lymphocytes (PBLs) plasma membrane. To this purpose, the effect of 6-mT SMF exposure on the redistribution of two main lipid raft components (i.e., disialoganglioside GD3, cholesterol) and on AgNPs uptake efficiency was investigated. Results showed that 6 mT SMF: (i) induces a time-dependent GD3 and cholesterol redistribution in plasma membrane lipid rafts and modulates gene expression of ATP-binding cassette transporter A1 (ABCA1), (ii) increases reactive oxygen species (ROS) production and lipid peroxidation, (iii) does not induce cell death and (iv) induces lipid rafts rearrangement, that, in turn, favors the uptake of AgNPs. Thus, it derives that SMF exposure could be exploited to enhance the internalization of NPs-loaded therapeutic or diagnostic molecules.

Asunto(s)

Linfocitos/citología , Microdominios de Membrana/metabolismo , Plata/farmacocinética , Transportador 1 de Casete de Unión a ATP , Adulto , Transporte Biológico , Endocitosis , Femenino , Humanos , Peroxidación de Lípido , Linfocitos/química , Campos Magnéticos , Masculino , Nanopartículas del Metal , Especies Reactivas de Oxígeno/metabolismo , Plata/química

RESUMEN

Objective::To clarify the inhibitory effect of essential oil from Alpinia zerumbet rhizome (EOFAZ) on oxidized low-density lipoprotein (ox-LDL)-induced transformation of macrophage into foam cell and explore its possible mechanism. Method::THP-1 monocyte was incubated with 100 μg·L-1 phorbol myristate acetate (PMA) to grow into macrophage, experiment was divided into 4 groups as follows, control group, model group (80 mg·L-1 ox-LDL), EOFAZ at low dose (80 mg·L-1 ox-LDL+ 4 μg·L-1 EOFAZ)and EOFAZ at high dose (80 g·L-1 ox-LDL+ 20 μg·L-1 EOFAZ). Mathye thiazolye telrazliurn (MTT) method was employed to examine the influence of EOFAZ on macrophage viability. Western blot was used to analyze the expression level of cluster of differentiation 36(CD36) and ATP-binding cassette transporter A1(ABCA1) protein in macrophage. Enzyme-linked immunosorbent assay (ELISA) was used to detect cholesteryl ester contents in macrophage. Oil red O staining was applied to determine the accumulation of lipids in macrophage. Result::EOFAZ showed non-toxic effect on macrophage. Compared to control group, macrophage in model group displayed higher level of cholesteryl ester and lipid droplet(P<0.01), as well as significant increasing of CD36 expression (P<0.01), but no effect on ABCA1 expression. EOFAZ notably reduced the contents of lipids and cholesteryl ester(P<0.01), down-regulated expression of CD36 and up-regulated expression of ABCA1 in macrophage in comparison with the model group(P<0.01), indicating that EOFAZ inhibited transformation of macrophage into foam cell. Conclusion::EOFAZ could inhibit ox-LDL-induced transformation of macrophage into foam cell, the underlying mechanism may involves its ability to increase CD36 expression and decrease ABCA1 expression in macrophage.

RESUMEN

OBJECTIVE: The aim of this study was to investigate the microRNA-200b-3p expression in lung adenocarcinoma and the possible functional associations of microRNA-200b-3p with cell proliferation, migration, and invasion. METHODS: Quantitative real-time polymerase chain reaction was used to detect the expression of microRNA-200b-3p in lung adenocarcinoma samples and in the human lung adenocarcinoma cell lines A549 and H1299. A549 and H1299 cells were transfected with either a microRNA-200b-3p mimic or a negative control microRNA or either an empty vector or an adenosine triphosphate-binding cassette transporter A-1 overexpression vector. A Cell Counting Kit-8 assay was employed to assess the ability of cell proliferation. Transwell assays and transwell-Matrigel invasion assay were, respectively, utilized to assess the capacity of migration and invasion in A549 and H1299 cells. RESULTS: The results showed that microRNA-200b-3p expression was significantly upregulated in tumor tissues compared with that in adjacent normal tissues. Overexpression of microRNA-200b-3p promoted lung adenocarcinoma cell proliferation and metastasis. Furthermore, adenosine triphosphate-binding cassette transporter A-1 was a direct target of microRNA-200b-3p, and this binding was verified by luciferase reporter analysis. Overexpression of adenosine triphosphate-binding cassette transporter A-1 obviously suppressed lung adenocarcinoma cell proliferation, migration, and invasion. Lung adenocarcinoma cell phenotypes induced by microRNA-200b-3p overexpression could be partially remitted by the co-overexpression of microRNA-200b-3p and adenosine triphosphate-binding cassette transporter A-1. CONCLUSION: This study first identified that microRNA-200b-3p is upregulated in lung adenocarcinoma cells and associated with cell proliferation and metastasis. MicroRNA-200b-3p promoted lung adenocarcinoma cell proliferation and metastasis by suppressing adenosine triphosphate-binding cassette transporter A-1. MicroRNA-200b-3p may function as a novel molecular marker and therapeutic target for lung adenocarcinoma treatment.

Asunto(s)

Transportador 1 de Casete de Unión a ATP/genética , Adenocarcinoma del Pulmón/genética , Regulación Neoplásica de la Expresión Génica , MicroARNs/genética , Oncogenes , Interferencia de ARN , Regiones no Traducidas 3' , Línea Celular Tumoral , Movimiento Celular/genética , Proliferación Celular/genética , Bases de Datos Genéticas , Humanos

RESUMEN

There is a relationship between the life cycle of the hepatitis C virus (HCV) and the synthesis and hemostasis of lipids as well as lipid metabolism and interferon (IFN) regulatory system. This study was aimed to examine the effect of fluvastatin and IFN-ƛ in the expression of mediators involved in lipid metabolism and HCV proliferation in patients with rs12979860 CC polymorphism. Thirteen patients with HCV and five controls with rs1297986CC polymorphism were included in this study. Peripheral blood mononuclear cells (PBMCs) of patients and controls were treated by fluvastatin, IFN-λ or fluvastatin+IFN-λ. Assessment of IL-28B polymorphism, RNA extraction, and quantitative reverse-transcription polymerase chain reaction (qRT-PCR) was performed. The mRNA expression of sterol regulatory element-binding protein 1 c (SREBP1c), ATP-binding cassette transporter A1 (ABCA1), diacylglycerol acyltransferase 1 (DGAT1), and HCV core as well as measurement of ABCA1 protein level were evaluated before and after treatment. The results indicated that IFN-λ +fluvastatin acted as an inhibitor in mRNA expression of SREBP1c; while acting as an inducer in the expression of ABCA-1. The results of ABCA1 assay showed a significant increase of this protein after treatment with fluvastatin and IFN-λ compared with untreated cells (p=0.02). Moreover, the mRNA expression of HCV core was suppressed in all experimental groups treated with fluvastatin, IFN-λ or their combination which was more significant after treatment with fluvastatin+IFN-λ (p<0.001). The results of this study demonstrated the significant effect of treatment with fluvastatin+IFN-λ in PBMCs of HCV patients with rs12979860 CC polymorphism. According to the drug resistance of viruses and prevention of virus-induced steatosis in patients with HCV, using regulatory agents of lipid mediators in parallel with current medications could be considered as an effective therapeutic strategy.

Asunto(s)

Fluvastatina/uso terapéutico , Hepatitis C Crónica/tratamiento farmacológico , Hepatitis C Crónica/genética , Interferones/genética , Interferones/farmacología , Leucocitos Mononucleares/efectos de los fármacos , Polimorfismo Genético/genética , Transportador 1 de Casete de Unión a ATP/genética , Adulto , Antivirales/uso terapéutico , Células Cultivadas , Sinergismo Farmacológico , Femenino , Genotipo , Hepacivirus/patogenicidad , Humanos , Masculino , Persona de Mediana Edad , Polimorfismo Genético/efectos de los fármacos

RESUMEN

Objective: To explore the effect of astragalus polysaccharide (APS) on oxidized low-density lipoprotein (ox-LDL)-induced lipid metabolism of macrophages and its underlying mechanism. Methods: The small interfering RNA (siRNA) targeting ATP binding cassette transporter A1 (ABCA1) was transfected into RAW 264.7 macrophages. Then the cells were stimulated with various concentrations of APS (20 mg/L, 60 mg/L and 150 mg/L), followed by the incubation with 50 mg/L ox-LDL for 24 h. qRT-PCR and Western blot were used to investigate the expression of ABCA1 mRNA and protein. Oil red O was used to analyze the level of foam cells. Lipid accumulation level was assessed by high performance liquid chromatography. [3H]-cholesterol was used to evaluate cholesterol efflux. Results: APS dose-dependently inhibited ox-LDL-induced formation of macrophage-derived foam cell compared with those in control group (P<0.05). HPLC analysis confirmed that APS attenuated lipid accumulation in a dose-dependent manner based on the decrease in ratio of cholesterol ester (CE)/total cholesterol (TC), concomitant with up-regulation of cholesterol efflux (P<0.05), indicating that APS might inhibit lipid deposition in macrophage by enhancing reverse cholesterol transport. Further more, APS dose-dependently increased ABCA1 mRNA and protein levels (P<0.05). When silencing ABCA1 expression with its specific siRNA, APS-inhibited lipid accumulation was significantly up-regulated, accompanied with the down-regulation of cholesterol efflux (P<0.05). Conclusion: APS may regulate lipid metabolism of macrophages by ABCA1-mediated progress of reverse cholesterol transport. Therefore, this study provides a potential target for the treatment of cardiovascular diseases triggered by vulnerable plaque.

RESUMEN

AIMS: Reverse cholesterol transport (RCT) is a process that prevents atherosclerosis. Studies showed that exercise training for strengthening cardiac muscle, increasing heart lipid metabolism and its potency against risk factors could protect cardiovascular health. Thus, the present study aims to investigate the effects of high intensity interval training (HIIT) on RCT and its related elements in plasma and tissues (liver and intestine) of rats. MATERIALS AND METHODS: Twenty adult male Wistar rats were randomly divided into control (n = 10) and trained (n = 10) groups. The trained group undertook HIIT (90%-95% of VO2max, five days/week, for 10 weeks) on a treadmill. The rats were killed five days after the last training session to minimize the effects of the last training session. KEY FINDINGS: A higher and significant ABCA1 mRNA was observed in the liver and intestine of trained rats. However, ABCG1 and LXR expressions only increased in the liver following the HIIT. These changes in the expression of the trained rats were accompanied by higher changes in plasma LCAT and HDL levels. SIGNIFICANCE: The responses of ABCA1, as a key player in plasma HDL biogenesis, are similar in liver and intestine tissues after the HIIT program. However, different responses of ABCG1 and LXR in the liver and intestine tissues of the trained rats confirm the main role of the liver than the intestine in HDL biogenes. Therefore, HIIT modality result in cardiovascular protection by increasing the expression of genes involved in RCT and biogenesis of HDL.

Asunto(s)

Aterosclerosis/prevención & control , Colesterol/metabolismo , Regulación de la Expresión Génica , Entrenamiento de Intervalos de Alta Intensidad , Mucosa Intestinal/metabolismo , Hígado/metabolismo , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 1/genética , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 1/metabolismo , Animales , Aterosclerosis/genética , Aterosclerosis/metabolismo , Receptores X del Hígado/genética , Receptores X del Hígado/metabolismo , Masculino , Consumo de Oxígeno , Fosfatidilcolina-Esterol O-Aciltransferasa/genética , Fosfatidilcolina-Esterol O-Aciltransferasa/metabolismo , Ratas , Ratas Wistar

RESUMEN

BACKGROUND: It has previously been demonstrated that apolipoprotein A-1 (apoA-1) binding protein (AIBP) promotes apoA-1 binding to ATP-binding cassette transporter A1 (ABCA1) and prevents ABCA1 protein degradation so as to inhibit foam cell formation. Because apoA-1 inhibits inflammatory signaling pathways, whether AIBP has an inhibitory effect on inflammatory signaling pathways in THP-1-derived macrophages is investigated.Methods and Results:Analysis of inflammation-related gene expression indicated that AIBP decreased lipopolysaccharide (LPS)-mediated macrophage inflammation. AIBP significantly prevented NF-κB nuclear translocation. Further, AIBP prevented the activation of mitogen-activated protein kinases (MAPKs), including p38 MAPK, extracellular-signal regulated kinase and c-Jun N-terminal kinase. AIBP decreased MyD88 expression at both mRNA and protein levels, but did not have any effect on TLR4 expression. Moreover, treatment with both AIBP and apoA-1 decreased the abundance of TLR4 in the lipid raft fraction. AIBP lacking 115-123 amino acids (∆115-123), however, did not have such effects as described for intact AIBP. In addition, knockdown of ABCA1 inhibited the effects of AIBP on inflammatory factor secretion. CONCLUSIONS: These results suggest that AIBP inhibits inflammatory signaling pathways through binding to apoA-1 and stabilizing ABCA1, and subsequent alteration of lipid rafts and TLR4 in the cell membrane.

Asunto(s)

Apolipoproteína A-I/metabolismo , Proteínas Portadoras/metabolismo , Células Espumosas/metabolismo , Sistema de Señalización de MAP Quinasas , Microdominios de Membrana/metabolismo , Transportador 1 de Casete de Unión a ATP/metabolismo , Proteínas de Unión al ADN , Células Espumosas/patología , Células HEK293 , Humanos , Inflamación/metabolismo , Inflamación/patología , Proteínas Quinasas JNK Activadas por Mitógenos/metabolismo , Microdominios de Membrana/patología , Células THP-1 , Receptor Toll-Like 4/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos

RESUMEN

Oxidative stress is an important risk factor contributing to the pathogenesis of cardiovascular diseases. Oxidative stress that results from excessive reactive oxygen species (ROS) production accounts for impaired endothelial function, a process which promotes atherosclerotic lesion or fatty streaks formation (foam cells). Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor involved in cellular redox homeostasis. Upon exposure to oxidative stress, Nrf2 is dissociated from its inhibitor Keap-1 and translocated into the nucleus, where it results in the transcriptional activation of cell defense genes. Nrf2 has been demonstrated to be involved in the protection against foam cells formation by regulating the expression of antioxidant proteins (HO-1, Prxs, and GPx1), ATP-binding cassette (ABC) efflux transporters (ABCA1 and ABCG1) and scavenger receptors (scavenger receptor class B (CD36), scavenger receptor class A (SR-A) and lectin-type oxidized LDL receptor (LOX-1)). However, Nrf2 has also been reported to exhibit pro-atherogenic effects. A better understanding on the mechanism of Nrf2 in oxidative stress-induced cardiac injury, as well as the regulation of cholesterol uptake and efflux, are required before it can serve as a novel therapeutic target for cardiovascular diseases prevention and treatment.

Asunto(s)

Enfermedades Cardiovasculares/metabolismo , Células Espumosas/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Estrés Oxidativo , Animales , Enfermedades Cardiovasculares/patología , Humanos , Factor 2 Relacionado con NF-E2/genética , Transducción de Señal

RESUMEN

ATP-binding cassette transporter A1 (ABCA1) mediates cholesterol efflux to lipid-free apolipoproteins and regulates the generation of high density lipoproteins. Previously, we have shown that lack of Abca1 significantly increases amyloid deposition and cognitive deficits in Alzheimer's disease model mice expressing human amyloid-ß protein precursor (APP). The goal of this study was to determine if ABCA1 plays a role in memory deficits caused by amyloid-ß (Aß) oligomers and examine neurite architecture of pyramidal hippocampal neurons. Our results confirm previous findings that Abca1 deficiency significantly impairs spatial memory acquisition and retention in the Morris water maze and long-term memory in novel object recognition of APP transgenic mice at a stage of early amyloid pathology. Neither test demonstrated a significant difference between Abca1ko and wild-type (WT) mice. We also examined the effect of intra-hippocampal infused Aß oligomers on cognitive performance of Abca1ko mice, compared to control infusion of scrambled Aß peptide. Age-matched WT mice undergoing the same infusions were also used as controls. In this model system, we found a statistically significant difference between WT and Abca1ko mice infused with scrambled Aß, suggesting that Abca1ko mice are vulnerable to the effect of mild stresses. Moreover, examination of neurite architecture in the hippocampi revealed a significant decrease in neurite length, number of neurite segments, and branches in Abca1ko mice when compared to WT mice. We conclude that mice lacking ABCA1 have basal cognitive deficits that prevent them from coping with additional stressors, which is in part due to impairment of neurite morphology in the hippocampus.

Asunto(s)

Transportador 1 de Casete de Unión a ATP/deficiencia , Trastornos del Conocimiento/metabolismo , Trastornos del Conocimiento/patología , Dendritas/metabolismo , Dendritas/patología , Transportador 1 de Casete de Unión a ATP/genética , Péptidos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Animales , Tamaño de la Célula , Femenino , Hipocampo/metabolismo , Hipocampo/patología , Humanos , Masculino , Aprendizaje por Laberinto/fisiología , Ratones Endogámicos C57BL , Ratones Transgénicos , Presenilina-1/genética , Presenilina-1/metabolismo , Reconocimiento en Psicología/fisiología , Memoria Espacial/fisiología

RESUMEN

OBJECTIVES: Intracranial atherosclerotic stenosis (ICAS) is one of the most common causes of stroke worldwide and, in particular, has been implicated as a leading cause of recurrent ischemic stroke. We adapted a rat model of atherosclerosis to study brain intracranial atherosclerosis, and further investigated the effect of omega-3 fatty acids (O3FA) in attenuating development of ICAS. MATERIALS AND METHODS: Adult male Sprague-Dawley rats were divided into control normal-cholesterol or high-cholesterol diet groups with or without O3FA for up to 6weeks. During the first 2weeks, NG-nitro-l-arginine methyl ester (l-NAME, 3mg/mL) was added to the drinking water of the high-cholesterol groups. The rats received supplementation with O3FA (5mg/kg/day) by gavages. Blood lipids including low density lipoprotein (LDL), cholesterol (CHO), triglycerides (TG) and high density lipoprotein (HDL) were measured at 3 and 6weeks. The lumen of middle cerebral artery (MCA) and the thickness of the vessel wall were assessed. Inflammatory molecular markers were assessed by Western blot. RESULTS: A high-cholesterol diet exhibited a significant increase in the classic blood markers (LDL, CHO, and TG) for atherosclerosis, as well as a decrease in HDL. These markers were found to be progressively more severe with time. Lumen stenosis and intimal thickening were increased in MCA. O3FA showed attenuation of blood lipids with an absence of morphological changes. O3FA significantly reduced the inflammatory marker CD68 in MCA and prevented monocyte chemotactic protein (MCP-1) and interferon-γ (IFN-γ) expression in the brain. O3FA similarly decreased inducible nitric oxide synthase (iNOS), tumor necrosis factor alpha (TNF-α), and interleukin 6 (IL-6), markers affiliated with monocyte activity in atherosclerosis. Furthermore, O3FA significantly inhibited the expression of vascular cell adhesion molecule-1 (VCAM-1), a marker for endothelial activation. Lastly, O3FA increased ATP-binding cassette transporter A1 (ABCA1) protein expression via silent information regulator 1 (SIRT1) activation, thus increasing cholesterol efflux from macrophages to HDL. CONCLUSIONS: Long-term O3FA dietary supplementation prevents the development of intracranial atherosclerosis. This O3FA effect appears to be mediated by its prevention of macrophage infiltration into the vessel wall, therefore reducing inflammation and intimal thickening. While similar effects in humans need to be determined, O3FA dietary supplement shows promising results in the prevention of ICAS.

Asunto(s)

Suplementos Dietéticos , Ácidos Grasos Omega-3/administración & dosificación , Arteriosclerosis Intracraneal/prevención & control , Transportador 1 de Casete de Unión a ATP/metabolismo , Animales , Antígenos CD/metabolismo , Antígenos de Diferenciación Mielomonocítica/metabolismo , Western Blotting , Encéfalo/irrigación sanguínea , Encéfalo/inmunología , Encéfalo/patología , Quimiocina CCL2/metabolismo , Colesterol/administración & dosificación , Colesterol/efectos adversos , Colesterol/sangre , Constricción Patológica/sangre , Constricción Patológica/inmunología , Constricción Patológica/patología , Constricción Patológica/prevención & control , Dieta Alta en Grasa/efectos adversos , Modelos Animales de Enfermedad , Interleucina-6/metabolismo , Arteriosclerosis Intracraneal/sangre , Arteriosclerosis Intracraneal/inmunología , Arteriosclerosis Intracraneal/patología , Masculino , Arteria Cerebral Media/patología , Ratas Sprague-Dawley , Sirtuina 1/metabolismo , Molécula 1 de Adhesión Celular Vascular/metabolismo

RESUMEN

BACKGROUND: ATP binding cassette transporter-A1 (ABCA1) facilitates the formation of high density lipoprotein (HDL). HDL due to its anti-atherosclerotic, anti-inflammatory and anti-thrombotic activities provides protection against atherothrombosis or myocardial infarction (MI). The aim was to investigate the role of peripheral blood mononuclear cell (PBMNC) ABCA1 expression in MI. METHODS: The participants comprised 29 males with acute MI (AMI) and 20 healthy controls. AMI patients were normotensive, not on statins, with triglycerides < 200mg/dl and categorized into AMI with type 2 diabetes (T2DM) (N = 12) and without T2DM (N = 17). The PBMNC ABCA1 mRNA transcripts were analysed by quantitative real-time polymerase chain reaction (qRTPCR) and protein by enzyme linked immunosorbent assay (ELISA). RESULTS: PBMNC ABCA1 mRNA transcript and protein levels were not significantly different in AMI patients or when sub-grouped into with/without T2DM, as compared to controls. ABCA1 protein correlated positively with HDL-cholesterol (r = 0.655, p = 0.021) in AMI patients with T2DM and negatively with age (r = - 0.525, p = 0.031) in AMI patients without T2DM and it was more strongly associated in latter group with smoking and alcohol habit. CONCLUSION: In the present study, the effects of metabolites of diabetes and ischemia were observed on PBMNC ABCA1 protein and thus on HDL-C in AMI patients. Further influence of risk factors such as smoking and alcohol consumption observed in the present study can be evaluated in larger sample size. The control of these cardiovascular associated risk factors may increase stability of PBMNC ABCA1 protein and thus HDL-C levels.

Asunto(s)

Transportador 1 de Casete de Unión a ATP/genética , Transportador 1 de Casete de Unión a ATP/metabolismo , Leucocitos Mononucleares/metabolismo , Infarto del Miocardio/sangre , Infarto del Miocardio/genética , Enfermedad Aguda , Adulto , Análisis Químico de la Sangre , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/genética , Ensayo de Inmunoadsorción Enzimática , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/complicaciones , Reacción en Cadena de la Polimerasa , ARN Mensajero/metabolismo , Factores de Riesgo , Estadística como Asunto

RESUMEN

Alpinetin is a natural flavonoid abundantly present in the ginger family. Here, we investigated the effect of alpinetin on cholesterol efflux and lipid accumulation in oxidized low-density lipoprotein (ox-LDL)-treated THP-1 macrophages and human peripheral blood monocyte-derived macrophages (HMDMs). After exposing THP-1 macrophages to alpinetin, cholesterol efflux was determined by liquid scintillator. The mRNA and protein levels of peroxisome proliferator-activated receptor gamma (PPAR-γ), liver X receptor alpha (LXR-α), ATP-binding cassette transporter A1 (ABCA1), and ABCG1 and scavenger receptor class B member 1 were determined by reverse-transcriptase PCR (RT-PCR) and Western blot analysis, respectively. Alpinetin promoted apolipoprotein A-I- and high-density-lipoprotein-mediated cholesterol efflux and elevated PPAR-γ and LXR-α mRNA and protein expression in a dose-dependent fashion in ox-LDL-treated THP-1 macrophages and HMDMs. Small interfering RNA-mediated silencing of PPAR-γ or LXR-α dose dependently reversed alpinetin-increased cholesterol efflux in THP-1 macrophages, indicating the involvement of PPAR-γ and LXR-α in alpinetin-promoted cholesterol efflux. Alpinetin inhibited ox-LDL-induced lipid accumulation and enhanced the expression of ABCA1 and ABCG1 mRNA and protein, which was reversed by specific knockdown of PPAR-γ or LXR-α. Taken together, our results reveal that alpinetin exhibits positive effects on cholesterol efflux and inhibits ox-LDL-induced lipid accumulation, which might be through PPAR-γ/LXR-α/ABCA1/ABCG1 pathway.

Asunto(s)

Colesterol/metabolismo , Flavanonas/farmacología , Lipoproteínas LDL/farmacología , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Transportador 1 de Casete de Unión a ATP/genética , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 1 , Transportadoras de Casetes de Unión a ATP/genética , Transporte Biológico/efectos de los fármacos , Línea Celular , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Receptores X del Hígado , Macrófagos/citología , Monocitos/citología , Receptores Nucleares Huérfanos/genética , PPAR gamma/genética

RESUMEN

Cholesterol accumulation is a critical step during the development and progression of atherosclerosis. Recently, Wnt5a expression has been found to be markedly upregulated in both murine and human atherosclerotic lesions. However, the effect and mechanism of Wnt5a in atherosclerosis is poorly understood. In the present study, we investigated the effects and potential mechanisms of Wnt5a on cholesterol accumulation during atherosclerosis. We used RAW264.7 and vascular smooth muscle cells (VSMC) treated with oxidized low-density lipoprotein (oxLDL) as lipid-loaded cell models. We found that expression of Wnt5a protein was increased in a concentration (25, 50, 75 and 100 µg/mL)- and time (24, 48 and 72 h)-dependent manner by oxLDL treatment. To explore the underlying mechanism, we used Wnt5a short interference (si) RNA to knockdown Wnt5a expression in both RAW264.7 cells and VSMC, or applied recombinant Wnt5a (rWnt5a) to stimulate Wnt5a signalling. After Wnt5a knockdown, total cholesterol (TC) and free cholesterol (FC) content in both cell types increased significantly (P < 0.05) upon exposure to oxLDL. Conversely, the TC and FC content decreased markedly (P < 0.05) after treatment of cells with rWnt5a. More importantly, both protein and mRNA expression of Caveolin-1 and ATP-binding cassette transporter A1 (ABCA1) was significantly reduced after exposure of wnt5a siRNA-treated cells to oxLDL, whereas rWnt5a treatment of cells resulted in increased Caveolin-1 and ABCA1 protein expression after exposure of cells to oxLDL. Together, these findings demonstrate, for the first time, that Wnt5a reduces the accumulation of cholesterol in lipid-loaded cells by regulating the mRNA expression of Caveolin-1 and ABCA1, which are involved in reverse cholesterol transport. This may present a novel mechanism of Wnt5a-mediated cholesterol transportation in macrophages and VSMC. Therefore, targeting the Wnt5a signalling pathway may have clinical implications in atherosclerosis.

Asunto(s)

Colesterol/metabolismo , Proteínas Wnt/metabolismo , Transportador 1 de Casete de Unión a ATP/biosíntesis , Animales , Aterosclerosis/metabolismo , Caveolina 1/biosíntesis , Células Cultivadas , Relación Dosis-Respuesta a Droga , Regulación de la Expresión Génica/efectos de los fármacos , Técnicas de Silenciamiento del Gen , Lipoproteínas LDL/farmacología , Masculino , Ratones , ARN Interferente Pequeño/farmacología , Ratas , Proteínas Wnt/biosíntesis , Proteínas Wnt/genética , Vía de Señalización Wnt , Proteína Wnt-5a

RESUMEN

Arsenic is a toxic element widely distributed in nature, such as water and soil. To survive this metalloid in the environment, nearly all organisms develop strategies to tolerate arsenic toxicity to some degree. Some arsenic-resistance genes have been identified in bacteria and yeast, but for mammals, especially humans, these genes are largely unknown. The aim of the present study was to identify these genes and benefit our intervention of arsenic resistance. We first established a human arsenic-resistant ECV-304 (AsRE) cell line and then used suppression subtractive hybridization and microarray analysis to identify arsenic-resistant genes in these cells. Of the significantly upregulated genes, three ATP-binding cassette (ABC) subfamily members, namely ABCA1, ABCE1 and ABCF1, were chosen for further study with RNA interference and overexpression analyses. The 3-(4,5-dimethyl-2 thiazoyl)-2,5-diphenyl-2H-tetrazolium bromide assay was used to determine the cell survival rate and the IC50 , whereas atomic fluorescence spectrophotometry was used to determine intracellular arsenic levels. We found that among the three ABC genes, only when ABCA1 gene expression was silenced did cells obviously lose their arsenic tolerance. The arsenic accumulation in ABCA1 deficiency AsRE cells was greater than that in wild type AsRE cells. Overexpression of ABCA1 in HeLa cells decreased arsenic accumulation in the cells and the cells were more resistant to As(III) than control cells transfected with empty vector. These results suggest a new functional role for ABCA1 in the development of arsenic resistance in human cells.

Asunto(s)

Transportador 1 de Casete de Unión a ATP/metabolismo , Arsénico/toxicidad , Transportador 1 de Casete de Unión a ATP/genética , Arsénico/metabolismo , Línea Celular , Humanos , Interferencia de ARN

RESUMEN

Recently, many studies have been focused on the association between the ATP-binding cassette transporter A1 (ABCA1) gene R219K polymorphism and ischemic stroke (IS). However, the study results have been inconsistent, especially in the Chinese population. Therefore, we performed a meta-analysis to better clarify the association between the ABCA1 gene and IS. All of the relevant studies used in our meta-analysis were identified using PubMed, OVID, Cochrane Library, Chinese Wan Fang database, Chinese VIP database, China National Knowledge Infrastructure (CNKI), and China Biological Medicine Database (CBM) up to May 2013. Statistical analysis was conducted with STATA software version 11.0. Odds ratios with 95% confidence intervals were applied to evaluate the strength of the association between ABCA1 gene R219K polymorphism and IS. Heterogeneity was evaluated using the Q-test and I(2) statistic. The funnel plots, Begg's and Egger's regression tests were used to assess the publication bias. Our meta-analysis showed the dominant genetic model (OR=0.92, 95% CI: 0.88-0.96), the recessive genetic model (OR=0.73, 95% CI: 0.51-1.05), the homozygote genetic model (OR=0.64, 95% CI: 0.44-0.94), the heterozygote genetic model (OR=0.81, 95% CI: 0.69-0.95), and the allelic genetic model (OR=0.83, 95% CI: 0.69-0.99). For R219K in IS, there were significant associations with these genetic models, but not with the recessive genetic model. Our meta-analysis indicated that the ABCA1 gene R219K polymorphism might be associated with IS and the K allele might be a protective factor in the Chinese population.

Asunto(s)

Transportador 1 de Casete de Unión a ATP/genética , Pueblo Asiatico/genética , Isquemia Encefálica/genética , Polimorfismo Genético/genética , Vigilancia de la Población , Accidente Cerebrovascular/genética , Pueblo Asiatico/etnología , Isquemia Encefálica/diagnóstico , Isquemia Encefálica/etnología , Estudios de Casos y Controles , Humanos , Vigilancia de la Población/métodos , Factores de Riesgo , Accidente Cerebrovascular/diagnóstico , Accidente Cerebrovascular/etnología

RESUMEN

OBJECTIVE: To observe the lipid and the pathological changes of carotid artery smooth muscle cells in atherosclerotic rabbits, verification of Chinese herbal compound which has improve blood lipid and anti atherosclerosis effects, focus on ABCA1 as the key receptor which participated in reverse cholesterol transport, to study the mechanism of Chinese herbal compound (Xuemai Ning). MATERIALS AND METHODS: 30 rabbits were randomly divided into blank group, model group and Chinese herbal compound (Xuemai Ning) group, The model group and the Xuemai Ning group with high fat diet and injection of vitamin D3, causing atherosclerosis model 4 weeks after the intervention of traditional Chinese medicine group, In the 4th week after Xuemai Ning group received the intervention of Chinese herbal compound. Blood lipid, the carotid artery pathological changes and expression of ABCA1 gene and protein in peritoneal macrophage surface were detected after 8 weeks. RESULTS: The carotid artery atherosclerotic plaque formation of the model group was obvious, the carotid atherosclerotic changes of the Xuemai Ning group rabbit significantly lighter than the model group. The serum lipid of model group and Xuemai Ning group were higher than that of the blank group; and the traditional Chinese medicine can up the expression of ABCA1 protein, higher than those in the model group. Expression of macrophage ABCA1 in model group was significantly up regulated at protein level higher than the blank group; and the traditional Chinese medicine can up regulate the expression of ABCA1 protein, higher than those in the model group. Expression of ABCA1 mRNA was significantly up regulated in model group, ABCA1 mRNA of Xuemai Ning group raised more significantly. CONCLUSION: Xuemai Ning can reduce triglyceride, total cholesterol and low density lipoprotein of hyperlipidemia model in rabbits serum, increase high density lipoprotein, remove foam cells in atherosclerotic cells, improve pathological of AS and up-regulate ABCA1 gene and protein so as to effectively inhibit atherosclerotic disease.

RESUMEN

Cholesterol efflux from macrophages is a critical mechanism to prevent the development of atherosclerosis. Here, we sought to investigate the effects of arctigenin, a bioactive component of Arctium lappa, on the cholesterol efflux in oxidized low-density lipoprotein (oxLDL)-loaded THP-1 macrophages. Our data showed that arctigenin significantly accelerated apolipoprotein A-I- and high-density lipoprotein-induced cholesterol efflux in both dose- and time-dependent manners. Moreover, arctigenin treatment enhanced the expression of ATP binding cassette transporter A1 (ABCA1), ABCG1, and apoE, all of which are key molecules in the initial step of cholesterol efflux, at both mRNA and protein levels. Arctigenin also caused a concentration-dependent elevation in the expression of peroxisome proliferator-activated receptor-gamma (PPAR-γ) and liver X receptor-alpha (LXR-α). The arctigenin-mediated induction of ABCA1, ABCG1, and apoE was abolished by specific inhibition of PPAR-γ or LXR-α using small interfering RNA technology. Our results collectively indicate that arctigenin promotes cholesterol efflux in oxLDL-loaded THP-1 macrophages through upregulation of ABCA1, ABCG1 and apoE, which is dependent on the enhanced expression of PPAR-γ and LXR-α.

Asunto(s)

Anticolesterolemiantes/farmacología , Colesterol/metabolismo , Furanos/farmacología , Lignanos/farmacología , Macrófagos/efectos de los fármacos , Receptores Nucleares Huérfanos/metabolismo , PPAR gamma/metabolismo , Transportador 1 de Casete de Unión a ATP/biosíntesis , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 1 , Transportadoras de Casetes de Unión a ATP/biosíntesis , Apolipoproteínas E/biosíntesis , Línea Celular , Humanos , Lipoproteínas LDL/metabolismo , Receptores X del Hígado , Macrófagos/metabolismo , Receptores Nucleares Huérfanos/antagonistas & inhibidores , Receptores Nucleares Huérfanos/genética , PPAR gamma/antagonistas & inhibidores , PPAR gamma/genética , ARN Interferente Pequeño/genética , Transducción de Señal/efectos de los fármacos