期刊：
INTERNATIONAL JOURNAL OF MOLECULAR MEDICINE,2012年29(5):946-956 ISSN：1107-3756
通讯作者：
Tang, Chao-Ke
作者机构：
[Zhao, Guo-Jun; Lv, Yun-Cheng; Jiang, Zhi-Sheng; Tang, Chao-Ke; Yin, Kai; Ouyang, Xin-Ping; Jiang, Jin; Mo, Zhong-Cheng] Univ S China, Inst Cardiovasc Res, Key Lab Atherosclerol Hunan Prov, Life Sci Res Ctr, Hengyang 421001, Hunan, Peoples R China.;[Fu, Yuchang] Univ Alabama Birmingham, Dept Nutr Sci, Birmingham, AL 35294 USA.
通讯机构：
[Tang, Chao-Ke] U;Univ S China, Inst Cardiovasc Res, Key Lab Atherosclerol Hunan Prov, Life Sci Res Ctr, Hengyang 421001, Hunan, Peoples R China.
关键词：
atherosclerosis;epigallocatechi n-3-gallate;ATP-binding membrane cassette transporter A1;Nrf2/Keap1 pathway;nuclear factor-kappa B
摘要：
The ATP-binding membrane cassette transporter A1 (ABCA1) plays a protective role in the development of atherosclerosis for the reverse cholesterol transport process. Epigallocatechin-3-gallate (EGCG), which exists abundantly in green tea, exerts an anti-atherosclerotic effect via anti-inflammatory and metabolic regulation activities. Many genes and proteins related to lipid metabolism are involved in the lowering cholesterol effects of EGCG. However, effects of EGCG on ABCA1 have rarely been described. In the study presented here, we found that exposure of macrophage foam cells to TNF-α results in a downregulation of ABCA1 and a decrease in cholesterol efflux to apoA1, which is attenuated by pretreatment with EGCG. Moreover, rather than activating the Liver X receptor (LXR) pathway, inhibition of the TNF-α-induced nuclear factor-κB (NF-κB) activity is detected with EGCG treatment in cells. In order to inhibit the NF-κB activity, EGCG can promote the dissociation of the nuclear factor E2-related factor 2 (Nrf2)-Kelch-like ECH-associated protein 1 (Keap1) complex; when the released Nrf2 translocates to the nucleus and activates the transcription of genes containing an ARE element inhibition of NF-κB occurs and Keap1 is separated from the complex to directly interact with IKKβ and thus represses NF-κB function. These results provide novel insight into the anti-inflammatory effects of EGCG, as well as the identification of a novel potential therapeutic role for the prevention of atherosclerosis.
摘要：
Pregnancy-associated plasma protein-A (PAPP-A) has been involved in the atherosclerotic process through regulation of local expression of IGF-1 that mediates the activation of the phosphatidylinositol-3 (PI3-K) and Akt kinase (Akt) signaling cascades which lead to constitutive nitric oxide formation, with its attending vasodilator, antiplatelet and insulin-sensitizing actions. In addition, IGF-1 may decreased cholesterol efflux through reductions of expression in ABCA1 and SR-B1 by the PI3-K/Akt signaling pathway. In the current study, we examined whether PAPP-A was involved in LXRα regulation and in expression of ABCA1, ABCG1 or SR-B1 through the IGF-I-mediated signaling pathway (IGF/PI3-K/Akt). Results showed that PAPP-A significantly decreased expression of ABCA1, ABCG1 and SR-BI at both transcriptional and translational levels in a dose-dependent and time-dependent manner. Cellular cholesterol content was increased while cholesterol efflux was decreased by PAPP-A treatment. Moreover, LXRα which can regulate the expression of ABCA1, ABCG1 and SR-B1, was also down-regulated by PAPP-A treatment. LXRα-specific activation by LXRα agonist almost rescued the down-regulation of ABCA1, ABCG1 and SR-B1 expression by PAPP-A. In addition, PAPP-A can induce the IGF-1/PI3-K/Akt pathway in macrophages. Furthermore, our results indicate that the decreased levels observed in LXRα, ABCA1, ABCG1 and SR-B1 mRNA and protein levels upon treating cells with PAPP-A were strongly impaired with the PI3-K inhibitors or IGF-1R siRNA while the MAPK cascade inhibitor did not execute this effect, indicating that the process of ABCA1, ABCG1 and SR-BI degradation by PAPP-A involves the IGF-1/PI3-K/Akt pathway. In conclusion, PAPP-A may first down-regulate expression of LXRα through the IGF-1/PI3-K/Akt signaling pathway and then decrease expression of ABCA1, ABCG1, SR-B1 and cholesterol efflux in THP-1 macrophage-derived foam cells. Therefore, our study provided one of the mechanisms for understanding the critical effect of PAPP-A in pathogenesis of atherosclerosis.
作者机构：
[Kai; ChaoKe] Institute of Cardiovascular Research, Key Laboratory for Atherosclerology of Hunan Province, Life Science Research Center, University of South China, Hengyang, China
通讯机构：
[ChaoKe Tang] I;Institute of Cardiovascular Research, Key Laboratory for Atherosclerology of Hunan Province, Life Science Research Center, University of South China, Hengyang, China
关键词：
Human Umbilical Vein Endothelial Cell;Berberine;Paraoxon;Percutaneous Coronary Interven;Cholesteryl Ester Hydrolase
摘要：
Atherosclerosis-related cardiovascular disease is one of the leading causes of death in China [1]. With advances in our understanding of the molecular mechanisms of atherosclerosis vascular inflammation, lipid metabolism dysfunction, and hypertension are regarded as the main pathogenetic pathways of both early atherogenesis and advanced plaque rupture [2,3]. Currently, much attention is being paid to the control of these pathways, which offers the potential for development of novel therapeutic approaches in the treatment of cardiovascular disease in China.
期刊：
Journal of Atherosclerosis and Thrombosis,2011年18(9):796-807 ISSN：1340-3478
通讯作者：
Tang, Chao-Ke
作者机构：
[Tang, Chao-Ke; Li, Xiao-Xu; Hu, Yan-Wei; Liu, Xie-Hong; Tang, Ya-Ling; Mo, Zhong-Cheng; Yi, Guang-Hui; Wang, Zuo; Xiao, Ji] Univ S China, Inst Cardiovasc Res, Key Lab Atherosclerol Hunan Prov, Life Sci Res Ctr, Hengyang 421001, Peoples R China.;[Liao, Duan-Fang] Hunan Univ Chinese Med, Div Stem Cell Regulat & Applicat, State Key Lab Chinese Med Powder & Med Innovat Hu, Changsha, Hunan, Peoples R China.
通讯机构：
[Tang, Chao-Ke] U;Univ S China, Inst Cardiovasc Res, Key Lab Atherosclerol Hunan Prov, Life Sci Res Ctr, Hengyang 421001, Peoples R China.
关键词：
Advanced oxidation protein products;ATP-binding cassette transporter A1;JAK/STAT;Cholesterol efflux
摘要：
AIMS: Advanced oxidation protein products (AOPPs) are new independent risk factor for coronary artery disease. This study was to determine the effects and potential mechanisms of AOPPs on cholesterol efflux from human macrophage foam cells. METHODS: Human THP-1 monocytes were preincubated with Phorbol-12-myristate- 13-acetate (PMA) and oxidized low density lipoprotein (ox-LDL) to form foam cells. The protein and mRNA expression were examined by western immunoblotting assays and real-time quantitative PCR, respectively. Cellular cholesterol content was measured by HPLC. The cholesterol efflux was assessed by liquid scintillation counting. RESULTS: AOPPs significantly decreased the expression of ATP-binding membrane cassette transporter A-1 (ABCA1) and liver X receptor alpha (LXRalpha) and reduced cholesterol efflux from THP-1 macrophage- derived foam cells. AOPPs substantially activated NADPH oxidase and activated Janus kinase/signal transducers and activators of transcription (JAK/STAT) signal pathway in THP-1-derived foam-like cells. Inhibiting NADPH oxidase by diphenyliodonium (DPI) effectively abolished the AOPPs-induced decrease in cholesterol efflux and the expression of ABCA1. Inhibiting JAK/STAT activation by its specific inhibitor AG-490 or by siRNA could also block AOPPs action on THP-1 cells. CONCLUSIONS: AOPPs may first down-regulate the expression of LXRalpha and ABCA1 through JAK/STAT signal pathway activation and then inhibit cholesterol efflux in THP-1-derived foam-like cells; therefore, our study may be useful for understanding the critical effects of AOPPs on the pathogenesis of atherosclerosis.
作者机构：
[Zhou, Shouhong; Tian, Shaowen; Ouyang, Xinping; Qiao, Ge; Wang, Ling] Univ S China, Coll Med, Dept Physiol, Hengyang 421001, Hunan, Peoples R China.;[Li, Peng] Univ S China, Coll Life Sci & Technol, Dept Biol, Hengyang 421001, Hunan, Peoples R China.;[Tang, Chaoke; Ouyang, Xinping] Univ S China, Life Sci Res Ctr, Inst Cardiovasc Dis, Hengyang 421001, Hunan, Peoples R China.
通讯机构：
[Tian, Shaowen] U;Univ S China, Coll Med, Dept Physiol, Hengyang 421001, Hunan, Peoples R China.
关键词：
Behavioral sensitization;Memory;Morphine;Rapid eye movement sleep deprivation;Sleep
摘要：
Previous studies have shown that behavioral sensitization is modulated by drug-associated context, in which memory processes may be critically involved. Sleep has been suggested to play an important role in memory processes. However, the relationship between sleep and context-modulated effects on behavioral sensitization remains to be elucidated. In the present study, we designed three experiments to explore the effects of rapid eye movement sleep deprivation (RSD) on context-modulated effects on morphine locomotor sensitization in mice. Mice were subjected to 6 h RSD starting either immediately after morphine pairing training or 6 h later. The control mice were returned to their home cages immediately after pairing training and left undisturbed. In experiment 1, RSD from 0 to 6h but not from 7 to 12 h disrupted paired context-modulated enhancement of locomotor activity. In experiment 2, RSD from 0 to 6 h but not from 7 to 12 h disrupted unpaired context-modulated suppression of locomotor activity. In experiment 3, RSD from either 0 to 6h or 7 to 12 h had no effect on conditioned locomotor activity. Our findings suggest that sleep plays a critical role in memory processes underlying context-modulated effects on morphine locomotor sensitization. (C) 2011 Elsevier Ireland Ltd. All rights reserved.
摘要：
The aryl hydrocarbon receptor (AhR) is a period-aryl hydrocarbon receptor nuclear transporter-simple minded domain transcription factor that shares structural similarity with circadian clock genes and readily interacts with components of the molecular clock. Activation of AhR by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) alters behavioral circadian rhythms and represses the Period1 (Per1) gene in murine hematopoietic stem and progenitor cells. Per1 expression is driven by circadian locomotor activity cycles kaput-brain muscle ARNT-like (CLOCK-BMAL1)–dependent activation of Eboxes in the Per1 promoter. We hypothesized that the effects of AhR activation on the circadian clock are mediated by disruption of CLOCK-BMAL1 function and subsequent Per1 gene suppression. Effects of AhR activation on rhythmic Per1 transcripts were examined in livers of mice after treatment with the AhR agonist, TCDD; the molecular mechanisms of Per1 repression by AhR were determined in hepatoma cells using TCDD and β-napthoflavone as AhR activators. This study reports, for the first time, that AhR activation by TCDD alters the Per1 rhythm in the mouse liver and that Per1 gene suppression depends upon the presence of AhR. Furthermore, AhR interaction with BMAL1 attenuates CLOCK-BMAL1 activity and decreases CLOCK binding at Ebox1 and Ebox3 in the Per1 promoter. Taken together, these data suggest that AhR activation represses Per1 through disrupting CLOCK-BMAL1 activity, producing dysregulation of rhythmic Per1 gene expression. These data define alteration of the Per1 rhythm as novel signaling events downstream of AhR activation. Downregulation of Per1 could contribute to metabolic disease, cancer, and other detrimental effects resulting from exposure to certain environmental pollutants.
摘要：
Atherosclerosis is characterized by a chronic inflammatory condition that involves numerous cellular and molecular inflammatory components. A wide array of inflammatory mediators, such as cytokines and proteins produced by macrophages and other cells, play a critical role in the development and progression of the disease. ATP-binding membrane cassette transporter A1 (ABCA1) is crucial for cellular cholesterol efflux and reverse cholesterol transport (RCT) and is also identified as an important target in antiatherosclerosis treatment. Evidence from several recent studies indicates that inflammation, along with other atherogenic-related mediators, plays distinct regulating roles in ABCA1 expression. Proatherogenic cytokines such as interferon (IFN)-γ and interleukin (IL)-1β have been shown to inhibit the expression of ABCA1, while antiatherogenic cytokines, including IL-10 and transforming growth factor (TGF)-β1, have been shown to promote the expression of ABCA1. Moreover, some cytokines such as tumor necrosis factor (TNF)-α seem to regulate ABCA1 expression in species-specific and dose-dependent manners. Inflammatory proteins such as C-reactive protein (CRP) and cyclooxygenase (COX)-2 are likely to inhibit ABCA1 expression during inflammation, and inflammation induced by lipopolysaccharide (LPS) was also found to block the expression of ABCA1. Interestingly, recent experiments revealed ABCA1 can function as an antiinflammatory receptor to suppress the expression of inflammatory factors, suggesting that ABCA1 may be the molecular basis for the interaction between inflammation and RCT. This review aims to summarize recent findings on the role of inflammatory cytokines, inflammatory proteins, inflammatory lipids, and the endotoxin-mediated inflammatory process in expression of ABCA1. Also covered is the current understanding of the function of ABCA1 in modulating the immune response and inflammation through its direct and indirect antiinflammatory mechanisms including lipid transport, high-density lipoprotein (HDL) formation and apoptosis.
摘要：
Cholesterol efflux from lipid-loaded cells is a key athero-protective event that counteracts cholesterol uptake. The imbalance between cholesterol efflux and uptake determines the prevention or development of atherosclerosis. Many proteins and factors participate in the cholesterol efflux event. However, there are currently no systematic models of reverse cholesterol transport (RCT) that include most RCT-related factors and events. On the basis of recent research findings from other and our laboratories, we propose a novel model of one center and four systems with coupling transportation and networking regulation. This model represents a common way of cholesterol efflux; however, the systems in the model consist of different proteins/factors in different cells. In this review, we evaluate the novel model in vascular smooth muscle cells (VSMCs) and macrophages, which are the most important original cells of foam cells. This novel model consists of 1) a caveolae transport center, 2) an intracellular trafficking system of the caveolin-1 complex, 3) a transmembrane transport system of the ABC-A1 complex, 4) a transmembrane transport system of the SR-B1 complex, and 5) an extracelluar trafficking system of HDL/Apo-A1. In brief, the caveolin-1 system transports cholesterol from intracellular compartments to caveolae. Subsequently, both ABC-A1 and SR-B1 complex systems transfer cholesterol from caveolae to extracellular HDL/Apo-A1. The four systems are linked by a regulatory network. This model provides a simple and concise way to understand the dynamic process of atherosclerosis.
摘要：
Aim: High density lipoprotein (HDL) and its apolipoproteins can promote cholesterol efflux from macrophage foam cells via the ATP-binding cassette transporter A1 (ABCA1), ABCG1, and scavenger receptor class B type. (SR-BI). Liver X receptors (LXRs) operate as cholesterol sensors which may protect from cholesterol overload by stimulating cholesterol efflux from cells to HDL through ABCA1, ABCG1 and SR-BI. The regulation of ABCA1, ABCG1 and SR-BI expression by cytokines present within the microenvironment of the atheroma may play an important role in determining the impact of reverse cholesterol transport on the atherosclerotic lesion. In the current study, we examined the effect of transforming growth factor-alpha 1 (TGF-alpha 1) on expressions of ABCA1, ABCG1 and SR-BI and explored the role of LXR alpha in the regulation of ABCA1, ABCG1 and SR-BI in THP-1 macrophage-derived foam cells. Methods and Results: TGF-alpha 1 significantly increased expressions of ABCA1, ABCG1 and SR-BI at both transcriptional and translational levels in a dose-dependent and time-dependent manner. Cellular cholesterol content was decreased while cholesterol efflux was increased by TGF-alpha 1 treatment. Moreover, LXR alpha was up-regulated by TGF-alpha 1 treatment. In addition, LXR alpha small interfering RNA completely abolished the promotion effect induced by TGF-alpha 1. Conclusion: These results provide evidence that TGF-alpha 1 up-regulates expressions of ABCA1, ABCG1 and SR-BI through the LXR alpha pathway in THP-1 macrophage-derived foam cells.
通讯机构：
[Yin, Weidong] U;Univ S China, Life Sci Res Ctr, Inst Cardiovasc Res, Key Lab Atherosclerol Hunan Prov, Hengyang 421001, Hunan, Peoples R China.
摘要：
Insulin resistance and dyslipidemia are both considered to be risk factors for metabolic syndrome. Low levels of IGF1 are associated with insulin resistance. Elevation of low-density lipoprotein cholesterol (LDL-C) concomitant with depression of high-density lipoprotein cholesterol (HDL-C) increase the risk of obesity and type 2 diabetes mellitus (T2DM). Liver secretes IGF1 and catabolizes cholesterol regulated by the rate-limiting enzyme of bile acid synthesis from cholesterol 7 alpha-hydroxylase (CYP7A1). NO-1886, a chemically synthesized lipoprotein lipase activator, suppresses diet-induced insulin resistance with the improvement of HDL-C. The goal of the present study is to evaluate whether NO-1886 upregulates IGF1 and CYP7A1 to benefit glucose and cholesterol metabolism. By using human hepatoma cell lines (HepG2 cells) as an in vitro model, we found that NO-1886 promoted IGF1 secretion and CYP7A1 expression through the activation of signal transducer and activator of transcription 5 (STAT5). Pretreatment of cells with AG 490, the inhibitor of STAT pathway, completely abolished NO1886-induced IGF1 secretion and CYP7A1 expression. Studies performed in Chinese Bama minipigs pointed out an augmentation of plasma IGF1 elicited by a single dose administration of NO-1886. Long-term supplementation with NO-1886 recovered hyperinsulinemia and low plasma levels of IGF1 suppressed LDL-C and facilitated reverse cholesterol transport by decreasing hepatic cholesterol accumulation through increasing CYP7A1 expression in high-fat/high-sucrose/high-cholesterol diet minipigs. These findings indicate that NO-1886 upregulates IGF1 secretion and CYP7A1 expression to improve insulin resistance and hepatic cholesterol accumulation, which may represent an alternative therapeutic avenue of NO-1886 for T2DM and metabolic syndrome. Journal of Endocrinology (2010) 204, 47-56
作者机构：
[Hu, Yan-Wei] Institute of Cardiovascular Research, Key Laboratory for Atherosclerology of Hunan Province, Life Science Research Center, University of South China, Hengyang, Hunan 421001 China;Department of Anesthesiology, The First Affiliated Hospital of University of South China, Hengyang, Hunan 421001, China;Research Unit, Health Research Division, Saskatchewan Cancer Agency, Department of Oncology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 4H4, Canada;Institute of Pharmacy and Pharmacology, Life Science Research Center, University of South China, Hengyang, Hunan 421001, China
通讯机构：
Institute of Cardiovascular Research, Key Laboratory for Atherosclerology of Hunan Province, Life Science Research Center, China
摘要：
ABCA1 is a key mediator of cholesterol efflux to apoA-I in cholesterol loaded macrophages, a first step of RCT in vivo. Unsaturated fatty acids can inhibit cholesterol efflux from macrophages by increasing degradation of ABCA1. However, the detailed mechanisms of ABCA1 regulation by unsaturated fatty acids are not fully understood. In the present study, we investigated the effects of EPA on ABCA1 expression and ABCA1-dependent cholesterol efflux and examined the role of cAMP/PKA pathway on the regulation of ABCA1 by EPA in THP-1 macrophage-derived foam cells. Results showed that EPA significantly destabilized ABCA1 protein and reduced ABCA1-dependent cholesterol efflux but had no effect on ABCA1 mRNA expression. We also revealed that EPA markedly reduced cAMP level and PKA activity and ABCA1 serine phosphorylation. PKA-specific activation by PKA agonist markedly compensated the down-regulation of ABCA1 serine phosphorylation and ABCA1-mediated cholesterol efflux by EPA, while, siRNA of PKA leaded to reduce of ABCA1 serine phosphorylation and ABCA1-mediated cholesterol efflux more significantly than EPA. However, EPA-Induced enhancement of degradation rate of ABCA1 protein did not change by treatment with PKA agonist or PKA-siRNA. These results provide evidence that EPA may have dual negative effects on ABCA1 activity by decreasing ABCA1 protein level and by reducing PKA-mediated ABCA1 serine phosphorylation in THP-1 macrophage-derived foam cells.
作者机构：
[Tang, Chao-ke; Li, Xiao-xu; Hu, Yan-wei; Liu, Xie-hong; Cao, Dong-li; Hao, Xin-rui; Xiao, Ji] Nanhua Univ, Univ S China, Inst Cardiovasc Res, Key Lab Atherosclerol Hunan Prov,Life Sci Res Ctr, Hengyang 421001, Hunan, Peoples R China.;[Liao, Duan-fang] Univ S China, Inst Pharm & Pharmacol, Life Sci Res Ctr, Hengyang 421001, Hunan, Peoples R China.;[Xiang, Jim] Univ Saskatchewan, Dept Oncol, Res Unit, Hlth Res Div,Saskatchewan Canc Agcy, Saskatoon, SK S7N 4H4, Canada.
通讯机构：
[Tang, Chao-ke] N;Nanhua Univ, Univ S China, Inst Cardiovasc Res, Key Lab Atherosclerol Hunan Prov,Life Sci Res Ctr, Hengyang 421001, Hunan, Peoples R China.
关键词：
ATP-binding cassette transporter A1;IFN-gamma;JAK/STAT1;Atherosclerosis;Reverse cholesterol transport
摘要：
Interferon gamma (IFN-gamma) is an immunomodulatory and anti-microbial cytokine, which has a variety of proatherogenic effects. It has been reported that IFN-gamma can down-regulate ABCA1 expression. However, its mechanism is elusive. In the present Study, we have investigated the effect of IFN-gamma on ABCA1 expression and cholesterol efflux in THP-1 macrophage-derived foam cells. IFN-gamma decreased ABCA1 expression at both transcriptional and translational levels in a dose-dependent manner. Cellular cholesterol content was increased while cholesterol efflux was decreased by IFN-gamma treatment. Liver X receptor a (LXR alpha), which can regulate the expression of ABCA1, was also down-regulated by IFN-gamma treatment. LXR alpha-specific activation by LXR alpha agonist almost compensated the down-regulation of ABCA1 expression by IFN-gamma, while siRNA of LXR alpha led to down-regulation of ABCA1 expression more significantly than IFN-gamma, IFN-gamma induced phosphorylation of STAT1 and expression of STAT1 alpha a in the nucleus, which was inhibited by a JAK inhibitor AG-490. Treatment with STAT1 siRNA further enhanced down-regulation of LXR alpha mRNA by IFN-gamma. Furthermore, AG-490 and STAT1 siRNA almost compensated the effect of IFN-gamma on ABCA1 expression and cholesterol efflux. In conclusion, IFN-gamma may first down-regulate expression of LXR alpha through the JAK/STAT1 signaling pathway and then decrease expression of ABCA1 and cholesterol efflux in THP-1 macrophage-derived foam cells. Therefore, our study may be useful in understanding the critical effect of IFN-gamma in pathogenesis of atherosclerosis. (C) 2008 Elsevier Ireland Ltd. All rights reserved.
