首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 551 毫秒
1.
AIM:To study whether homocysteine (Hcy) inhibits the expression of ATP-binding cassette transporter A1 (ABCA1) and ATP-binding cassette transporter G1 (ABCG1) by microRNA-33 (miRNA-33) signaling, and reduces the efficiency of reverse cholesterol transport (RCT).METHODS:RAW264.7 macrophages were induced by oxidized low-density lipoprotein (ox-LDL) to establish foam cell model. Oil red O staining was used to determine whether the model was established successfully. miRNA-33 mimics and miRNA-33 inhibitor were transfected into the cells by Lipofectamine 2000, and the cells were exposed to Hcy at concentration of 5 mmol/L for 24 h. The intracellular lipid droplets were observed by Oil red O staining. The expression of ABCA1 and ABCG1 at mRNA and protein levels was determined by real-time PCR and Western blot. The cellular cholesterol content was analyzed by HPLC, and effluent rate of cholesterol was detected by the method of liquid scintillation counting.RESULTS:Compared with blank control group, the lipid content in miRNA-33 mimics group was increased, and the expression of ABCA1 and ABCG1 at mRNA and protein levels was decreased (P<0.05). The intracellular cholesterol content was increased gradually (P<0.05), and the cellular cholesterol efflux rate was gradually decreased (P<0.05) in miRNA-33 mimics group. Compared with blank control group, the testing results in miRNA-33 inhibitor group were the opposition of those in miRNA-33 mimics group (P<0.05). No diffe-rence of the above indexes among blank control group, miRNA-33 mimics-NC group and miRNA-33 inhibitor-NC group was observed.CONCLUSION:Hcy inhibits the mRNA and protein expression of ABCA1 and ABCG1 through miRNA-33 signaling, and reduces the efficiency of RCT in RAW264.7 macrophage-derived foam cells.  相似文献   

2.
AIM: To investigate the regulation of ghrelin on the expression of ATP-binding cassette transporter A1 and G1 (ABCA1/ABCG1)during the foam cell formation. METHODS: The human monocytic leukemia cell line (THP-1)was chosen in our study. The differentiation of THP-1 cells into macrophages was induced by using phorbol myristate acetate (PMA). Macrophages were then incubated with oxidized LDL (ox-LDL)to generate foam cells. Ghrelin of different concentrations were treated at different time points during foam cell formation. The ABCA1/ABCG1 protein and mRNA levels were detected by Western blotting and RT-PCR. The effect of variance of cholesterol content was measured by zymochemistry via-fluorospectrophotometer. RESULTS: Ghrelin reduced the content of lipid droplet in foam cells, and increased the efflux of intracellular cholesterol significantly. Ghrelin increased ABCA1 protein mass and mRNA level in dose-dependent manner. The changes of ABCG1 protein and mRNA level were the same as ABCA1. CONCLUSION: Ghrelin interfere atherosclerosis by up-regulating the expression of ABCA1 and ABCG1.  相似文献   

3.
AIM: To observe the effects of CD137-CD137 ligand(CD137L) interaction on the nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1) in apolipoprotein E-knockout (ApoE-/-) mice. METHODS: Atherosclerotic plaque model was produced by perivascular carotid collar placement in ApoE-/- mice. In vivo, the expression levels of NFATc1 in mouse plaques and lymphocytes were detected by immunohistochemical method and flow cytometry, respectively. In vitro, the expression of NFATc1 at mRNA and protein levels in cultured lymphocytes of ApoE-/- mice was measured by RT-PCR and flow cytometry, respectively. RESULTS: In vivo, after CD137-CD137L signaling pathway was stimulated, the expression of NFATc1 was significantly increased in the atherosclerotic plaques and lymphocytes. In vitro, the expression of NFATc1 at mRNA and protein levels in cultured leukocytes of ApoE-/- mice was also significantly increased, with the maximal effect exerted by anti-CD137 monoclonal antibody (mAb) at the concentration of 20 mg/L, and 24 h after stimulation at any concentration (P<0.05). Anti-CD137L mAb significantly inhibited the expression of NFATc1 at mRNA and protein levels in the lymphocytes of ApoE-/- mice, with the maximal effect exerted by anti-CD137L mAb at the concentration of 20 mg/L, and 24 h after stimulation (P<0.05). CONCLUSION: CD137-CD137L interaction can regulate the expression of NFATc1 in ApoE-/- mice.  相似文献   

4.
AIM To explore the anti-atherosclerotic mechanism of Wendan decoction based on reverse cholesterol transport. METHODS Eight-week-old apolipoprotein E gene knockout （ApoE-/-） mice with high-fat diet and daily drug gavage were randomly divided into model group, simvastatin group, and low-, middle- and high-dose Wendan decoction groups, with 15 mice in each group. The C57BL/6 mice of the same age served as control group. The mice were weighed once every week. After 10 weeks, the mice were anesthetized with chloral hydrate. The serum were collected for lipid level examination. The atherosclerotic plaque buildup in aortic root and whole aorta was observed by HE staining and oil red O staining, respectively. The levels of proteins related to cholesterol transport, ATP-binding cassette transporter A1 （ABCA1） and caveolin-1 in the aorta, and scavenger receptor class B type I （SR-BI） and CD36 in the liver, were quantified by Western blot. RESULTS Wendan decoction at middle dose inhibited the increase in the body weight of ApoE-/- mice fed with high-fat diet （P<0.05）. Wendan decoction at different doses significantly reduced the serum levels of triglyceride, total cholesterol and low-density lipoprotein cholesterol in the ApoE-/- mice （P<0.05 or P<0.01）, but had no effect on serum high-density lipoprotein cholesterol level （P>0.05）. Wendan decoction at different doses inhibited the formation of atherosclerotic plaques in whole aorta of the ApoE-/- mice （P<0.05 or P<0.01）. Middle- and high-dose Wendan decoction significantly inhibited the formation of atherosclerotic plaques in the aortic root （P<0.05）. Bedsides, Wendan decoction at different doses increased the protein level of ABCA1 and decreased the protein level of caveolin-1 in the aorta of the ApoE-/- mice （P<0.01）. Middle- and high-dose Wendan decoction increased the liver protein level of SR-BI in the ApoE-/- mice （P<0.01）. However, Wendan decoction at different doses had no effect on the liver protein level of CD36 in the ApoE-/- mice （P>0.05）. CONCLUSION Wendan decoction reduces the body weight, serum lipid levels and formation of atherosclerotic plaques in ApoE-/- mice fed with high-fat diet, and its mechanism is related to up-regulation of ABCA1 protein level in the aorta and SR-BI protein level in the liver as well as down-regulation of caveolin-1 protein level in the aorta.  相似文献   

5.
AIM:To investigate the change of cell calcium ion transporter ryanodine receptor 3(RYR3) in the aorta smooth muscle cells of apolipoprotein E gene-deficient(ApoE-/-) mice, and to elucidate the relationship between RYR3 and atherosclerotic plaque in ApoE-/- mice. METHODS:Six-week-old ApoE-/- mice and wild-type C57BL/6J mice were used in the experiment. The animals were sacrificed for pathological observation at the time points of 20, 27 and 33 weeks after hyperlipidic diet, respectively. Four sections of the aortic root were prepared and HE and immunohistochemical staining were performed. All the sections were analyzed with a computer image analysis system. RESULTS:Compared with the controls, the expression of RYR3 was markedly lower in ApoE-/- mice(P<0.05). As the age of ApoE-/- mice increasing, the expression of RYR3 decreased significantly, and was negatively correlated to the plaque area corrected by lumen area(r＝-0.652, P<0.01). CONCLUSION:Cell calcium ion transporter RYR3 participates in the pathological process of atherosclerosis, and is closely related to the formation of atherosclerotic plaques.  相似文献   

6.
  相似文献   

7.
AIM:Mast cells (MC) are present in the arterial intima,the site of atherogenesis. The present studies explore the effect of MC on cholesterol content,distribution and efflux in THP-1 macrophage-derived foam cells (THP-1FCs）. METHODS:THP-1FCs were incubated with high-density lipoproteins 3 (HDL3) in the absence or presence of mast cell granules (MCGs) harvested from compound 48/80-stimulated rat peritoneal MC. The intracellular cholesterol level,cholesterol effluxing capacity,ATP-binding cassette transporter A1(ABCA1) mRNA and HDL3 treated with MCGs were detected to characterize the role of MC on intracellular cholesterol. RESULTS:MCGs had high levels of cellular total cholesterol(TC),free cholesterol(FC) but not esterifed cholesterol(EC) compared to control group where the TC concentrations ranged from 527.3 mg/g to 917.9 mg/g cellular protein with EC accounting for 7.6% of the cholesterol. Cholesterol efflux was 14% less in MCGs group compared to control group. ABCA1 mRNA expression in MCG-treated THP-1FCs remained unchanged in 20 hours. In contrast,treatment of HDL3 with MCGs resulted in rapid degradation of the main HDL3 apoliproteins,apoA-Ⅰ. SDS-PAGE revealed that a minor polypeptide band with about 26 kD molecular mass appeared below the apoA-Ⅰband. Densitometric analysis of the gel demonstrated that ≈ 28% of apoA-Ⅰhad been degraded by the MCGs. CONCLUSION:These results indicate that MC decreases cholesterol efflux,increases cellular accumulation in TC and FC by depleting HDL3 and apoA-Ⅰ,but not by inhibiting ABCA1 mRNA expression.  相似文献   

8.
  相似文献   

9.
AIM: To investigate the perturbative effects of inflammatory stress on cholesterol efflux in human kidney mesangial cells (HMCs) and the relation to peroxisome proliferators activated receptor-γ (PPARγ)-1iver X activated receptor-α (LXRα)-and ATP-binding cassette transporter A1 (ABCA1) pathway. METHODS: HMCs were cultured and divided into control group (incubated with serum free medium), high lipid group , inflammatory stress group or combination treatment group . The mRNA and protein levels of PPARγ, LXRα,ABCA1 were examined by real-time polymerase chain reaction (PCR) and Western blotting. cholesterol assay was performed to evaluate the efflux of cholesterol by liquid scintillation counter. Oil red O staining was used to evaluate lipid droplet accumulation in the cells. Intracellular cholesterol level was measured by enzymic assay. RESULTS: : LDL increased the expression of PPARγ, LXRα and ABCA1 at mRNA and protein levels in HMCs, while TNF-α reduced the expression of these genes at mRNA and protein levels. The cholesterol efflux was increased after LDL loading. However, inflammatory stress inhibited cholesterol efflux in the absence or presence of LDL loading. Oil red O staining and quantitative analysis showed that LDL loading increased the intracellular cholesterol level in HMCs and inflammatory stress further exacerbated the lipid accumulation. CONCLUSION: Inflammatory cytokine reduces cholesterol efflux by inhibiting the expression of PPARγ, LXRα and ABCA1, thereby causing lipid accumulation in HMCs.  相似文献   

10.
AIM: To compare the effects of high-density lipoprotein (HDL) from healthy subjects (HDLheathy) and HDL from the patients with coronary artery disease (HDLCAD) on the lipid deposition and apoptosis in mouse peritoneal macrophages. METHODS: HDL was isolated from healthy subjects, stable CAD patients (HDLSCAD) and acute myocar-dial infarction patients (HDLAMI). The accumulation of intracellular lipids was determined by oil red O staining. The apoptosis of macrophages was measured by fluorescence microscopy with annexin-V/PI staining. DCHF-DA, a redox-sensitive dye, was used to detect intracellular reactive oxygen species (ROS) levels. The protein expression of ATP-binding cassette transporter (ABC) A1, ABCG1, Bcl-2 and Bax was determined by Western blot analysis. RESULTS: Lipid deposition in the macrophages was increased significantly after oxidized low-density lipoprotein (ox-LDL) treatment, and the expression of ABCA1 and ABCG1 was up-regulated (P<0.05). Compared with ox-LDL treatment alone, HDLhealthy decreased lipid deposition in the macrophages and up-regulated the expression of ABCA1 and ABCG1 (P<0.05), while treatment with HDLSCAD or HDLAMI further decreased lipid deposition in the macrophages and down-regulated the expression of ABCA1 and ABCG1 (P<0.05). Compared with HDLSCAD treatment, lipid deposition in the macrophages was further increased after HDLAMI treatment, and the expression of ABCA1 and ABCG1 was down-regulated (P<0.05). HDLhealthy decreased the levels of intracellular ROS and apoptosis by increasing the level of antiapoptotic protein Bcl-2 and reducing the expression of proapoptotic protein Bax. In contrast, HDLSCAD and HDLAMI had opposite effects on the intracellular ROS, the cell apoptosis and the expression of apoptosis-related proteins Bcl-2 and Bax. CONCLUSION: HDLCAD promotes lipid accumulation in macrophages and induces macrophage apoptosis. These findings provide novel insights into mechanisms leading to altered vascular effects of HDL in CAD.  相似文献   

11.
AIM To verify whether Cordyceps militaris polysaccharide （CMPS） has the effect of promoting reverse cholesterol transport （RCT） in vitro and in vivo， and to explore the underlying mechanism. METHODS For in vivo experiments， RCT efficiency was detected in cholesterol ester transporter transgene （CETP-tg） mice by isotope tracer technique， and the plasma lipid levels were measured by enzyme method. For in vitro experiments， the residual lipid content after cholesterol efflux in RAW264.7 macrophage-derived foam cells was tested by oil red O staining and total cholesterol （TC） kit. Western blot was used to analyze the protein expression of the molecules involved in cholesterol transport， uptake and transformation in the foam cells and mice liver. RESULTS After 4 weeks of intragastric administration of CMPS， the concentrations of TC， low-density lipoprotein cholesterol （LDL-C） and high-density lipoprotein cholesterol （HDL-C） in the plasma of CETP-tg mice were reduced by 24%， 23% and 22%， respectively. RCT efficiency of CETP-tg mice was accelerated and the appearance of 3H-cholesterol tracer in plasma， bile， intestine and feces was significantly increased in CMPS group. Meanwhile， the expression levels of cholesterol receptors scavenger receptor B1 （SR-B1） and LDL receptor （LDLR）， and cholesterol converting rate-limiting enzyme cholesterol 7α-hydroxylase A1 （CYP7A1） were upregulated by 105%， 71% and 58% in the liver of CMPS group， respectively. The results of in vitro experiments showed that CMPS preincubation promoted cholesterol efflux， decreased intracellular lipid and TC levels， and up-regulated the expression of peroxisome proliferator-activated receptor γ （PPARγ）-liver X receptor α （LXRα）-ATP-binding cassette transporter A1 （ABCA1）/ABCG1 signaling pathway related proteins in macrophage-derived foam cells. CONCLUSION CMPS promotes excess cholesterol efflux from peripheral macrophage-derived foam cells and accelerates its discharge through liver pathway. PPARγ-LXRα-ABCA1/ABCG1 pathway may be involved in the mechanism.  相似文献   

12.
  相似文献   

13.
AIM:To investigate the effects of interleukin-17A (IL-17A) on the expression of adenosine triphosphate binding cassette transporter A1 (ABCA1) in RAW264.7 macrophages. METHODS:Mouse RAW264.7 macrophages were treated with IL-17A at different concentrations for 6 or 24 h, or treated with IL-17A at the same concentration for different time. The expression of ABCA1 at mRNA and protein levels was determined by RT-qPCR and Western blot, respectively. Cholesterol efflux to apolipoprotein A1 (ApoA-1) was evaluated by NBD-cholesterol method. Lipid accumulation in the cells was evaluated by Oil Red O staining. RESULTS:Compared with control group, IL-17A increased the expression of ABCA1 at protein level in the RAW264.7 cells significantly (P<0.05), but had no effect on the mRNA expression of ABCA1. In addition, cholesterol efflux to ApoA-1 was increased and lipid accumulation in the RAW264.7 cells was decreased obviously after treatment with IL-17A. CONCLUSION:IL-17A increases the protein expression of ABCA1 but not at mRNA level in the RAW264.7 macrophages, which may be correlated with its anti-atherosclerosis effect.  相似文献   

14.
AIM: To observe the protective effects of butylphthalide on atherosclerosis lesion and vascular cell adhesion molecular-1 (VCAM-1) expression in the aortic wall of ApoE-/- mice, and to explore the possible mechanism underlying these beneficial effects.METHODS: Male ApoE-/- mice at 6 weeks of age (n=90) were randomly divided into 3 groups. Thirty ApoE-/- mice fed with high-fat diet and treated with saline simultaneously were defined as model group. Thirty ApoE-/- mice fed with high-fat diet and treated with butylphthalide (100 and 200 mg·kg-1·d-1) were defined as treatment groups. Thirty wild-type C57BL/6J mice treated with saline were defined as control group. Fifteen mice in each group were sacrificed both at the ages of 18 and 30 weeks. The body weight, food intake and water intake were monitored weekly through the experiment. The lipid profiles were determined both at 18 and 30 weeks of age. Aortic roots were stained with hematoxylin and eosin for pathological examination. Serum ox-LDL, CRP, TNF-α and IL-6 were examined by ELISA. The expression of VCAM-1 at mRNA and protein levels was determinate by real-time PCR and Western blot in the thoracic aortas. RESULTS: Compared with control group, at 18 and 30 weeks of age, the body weight, serum lipid profiles and inflammatory factors were increased, while the atherosclerotic plaques were raised. The mRNA and protein levels of VCAM-1 were up-regulated. However, serum lipid levels in butylphthalide treatment groups (both at doses of 100 and 200 mg·kg-1·d-1) were decreased significantly. Serum ox-LDL, CRP, TNF-α and IL-6 were also decreased by butylphthalide treatment. Furthermore, atherosclerotic plaque areas in the aortic roots were reduced by butylphthalide treatment. In addition, the expression of VCAM-1 at mRNA and protein levels in the thoracic aortas was down-regulated by butylphthalide treatment.CONCLUSION: Butylphthalide delays the occurrence of high-fat diet-induced atherosclerosis and down-regulates the expression of VCAM-1 in the ApoE-/- mice, which may be due to its alleviative effects on hyperlipidemia and inflammation.  相似文献   

15.
AIM:To study the action of ATP binding cassette transporter(ABC) A 1 on cholesterol efflux in THP-1 macrophage-derived foam cells.METHODS:After exposure of the cultured THP-1 macrophage-derived foam cells to 22(R)-hydroxycholesterol and 4, 4'-diisothiocyanostilbene-2, 2'-disulfonic acid (DIDS) at different concentration for 24 hours, cholesterol efflux and ABCA1 mRNA level were determined by FJ-2107P type liquid scintillator and reverse trancriptase-polymerase chaim reaction(RT-PCR), respectively.RESULTS:Oxidized LDL promoted cholesterol efflux in THP-1 macrophages and 22(R)-hydroxycholesterol increased cholesterol efflux in THP-1 macrophage-derived foam cells in a dose-dependent manner and DIDS inhibited cholesterol efflux in THP-1 macrophage-derived foam cells in a dose-dependent manner. Exposure of the cultured THP-1 macrophage-derived foam cells to 22(R)-hydroxycholesterol and DIDS at different concentration for 24 hours, resulted in increase and decrease in the expression of ABCA1 mRNA in THP-1 macrophage-derived foam cells in a dose-dependent manner, respectively.CONCLUSION:ABCA1 playes an important role in cholesterol efflux in THP-1 macrophage-derived foam cells.  相似文献   

16.
AIM:To study the influence of angiotensin Ⅱ (AngⅡ) on ATP-binding cassette transporter A1 in THP-1 derived foam cells. The variance of the expression of ABCA1, the content and the effluent rate of cholesterol were also investigated. METHODS:The regulatory effect of AngⅡ on the expression of ABCA1 mRNA and protein in THP-1 derived form cells were measured by RT-PCR and Western blotting. The effect of variance of cholesterol content was measured by zymochemistry via-fluorospectrophotometer, cholesterol effluent was measured by liquid scintillator. RESULTS:A positive facilitative effect of Ang Ⅱon form cells was observed. Total cholesterol content were increased significantly by Ang Ⅱ treatment (P<0.05). The mRNA and protein of ABCA1 were down-regulated significantly by Ang Ⅱ stimulation (P<0.05). Irbesartan reduced the total cholesterol content significantly (P<0.05). Meanwhile, the increase in the effluent rate of cholesterol and the expression of ABCA1 were observed (P<0.05). CONCLUSION:The effects of Ang Ⅱ on the formation of foam cells and atherosclerosis may be correlated to the activation of AT1 receptor and down-regulation of ABCA1.  相似文献   

17.
AIM To observe the effect of retinoid X receptor α （RXRα） agonist bexarotene （Bex） on the proliferation of transforming growth factor β1 （TGF-β1）-induced vascular smooth muscle cells （VSMCs） and atherosclerosis in apolipoprotein E knockout （ApoE-/-） mice， and to explore the underlying mechanism. METHODS Ten C57BL/6 mice were selected as normal control group， and 30 ApoE-/- mice were randomly divided into 3 groups： ApoE-/- group， ApoE-/-+Bex5 （5 mg·kg-1·d-1 Bex） group and ApoE-/-+Bex10 （10 mg·kg-1·d-1 Bex） group. Bex was intragastrically given once a day for 8 weeks. The levels of triglyceride （TG） and total cholesterol （TC） were determined by oxidase method， and select masking method was used to determine serum levels of low-density lipoprotein cholesterol （LDL-C） and high-density lipoprotein cholesterol （HDL-C）. The protein levels of TGF-β1， p-Smad2 and Smad2 were determined by Western blot. HE staining was used to observe the intima of the thoracic aorta. The VSMCs were cultured with tissue patch method， and the proliferation of VSMCs was measured by BrdU incorporation method. RESULTS The serum levels of TG， TC and LDL-C， and the expression of TGF-β1 and p-Smad2 in thoracic aorta in ApoE-/- group were significantly higher than those in C57BL/6 group （P<0.01）. Bex increased p-Smad2 protein level in thoracic aorta in a dose-dependent manner， inhibited the intimal plaque formation and vascular medial proliferation， and decreased the plaque area in ApoE-/- mice （P<0.01）. No significant difference in serum levels of TG， TC， HDL-C and LDL-C， and TGF-β1 and Smad2 expression in thoracic aorta among ApoE-/- group， ApoE-/-+Bex5 group and ApoE-/-+Bex10 group was observed. TGF-β1 （0.1~10 μg/L） promoted the proliferation of VSMCs， while Bex （10-9~10-7 mol/L） inhibited TGF-β1 （5 μg/L）-induced proliferation of VSMCs in a concentration-dependent manner. Bex （10-7 mol/L） synergistically promoted the protein level of p-Smad2 in VSMCs induced by TGF-β1 （P<0.01）， but inhibited TGF-β1-induced nuclear translocation of p-Smad2. CONCLUSION RXRα agonist Bex inhibits the formation of atherosclerosis in ApoE-/- mice， and its mechanism may be related to the regulation of TGF-β1/Smad2 pathway.  相似文献   

18.
FENG Xiang  LING Wen-hua 《园艺学报》2003,19(9):1246-1249
AIM:To explore the effects of oxidized low density lipoprotein (OxLDL) and one of its component— lysophosphatidylcholine (LPC) on cholesterol efflux from mouse macrophage foam cells.METHODS:(1) Cholesterol efflux induced by apoAI from mouse peritoneal macrophage foam cells loaded with OxLDL or acylated LDL(AcLDL) was measured. (2) Cholesterol efflux induced by LPC and apoAI from macrophage foam cells separated from normal or apoE gene deficient (E0) mouse loaded with AcLDL were measured.RESULTS:(1) When the macrophage foam cells were incubated with apoAI, cholesterol efflux from AcLDL-induced macrophage foam cells increased significantly compared to that of OxLDL-induced macrophage foam cells. (2) LPC promoted cholesterol efflux from macrophage foam cells in relation to both dosage and time. When LPC was incubated with E0 mouse macrophage foam cells, the released cholesterol mass was significantly lower than that of normal mouse macrophage foam cells. It was also found that cholesterol efflux induced by apoAI normally occurred in E0 mouse macrophage foam cells.CONCLUSIONS:(1) OxLDL accumulated cholesterol in macrophages and impair cholesterol efflux. (2) LPC induced cholesterol efflux from macrophage foam cells, which may occur via apoE pathway.  相似文献   

19.
AIM: To examine the effects of hypoxia on sodium-hydrogen exchange 1(NHE1) expression, intracellular Ca2+ concentration ([Ca2+]i) and calpain activity, and to explore the effect of amiloride on adenosine triphosphate-binding cassette transporter A1(ABCA1) degradation and its calpain-related mechanism. METHODS: RAW264.7 cells were exposed to hypoxia for 0 h, 12 h, 24 h and 48 h. The cell viability was measured by MTT assay and the expression of NHE1 at mRNA and protein levels was detected by real-time PCR and Western blot. [Ca2+]i was analyzed by flow cytometry. Calpain activity was assessed by the method of Suc-LLVY-aminoluciferin. Furthermore, the protein levels of ABCA1 in the RAW264.7 cells exposed to hypoxia for 24 h were determined after 6 h or 12 h treatment with NHE1 inhibitor amiloride in the presence of cycloheximide. ABCA1 protein levels and calpain activity were detected after 12 h incubation with calpain inhibitor ALLN or intracellular calcium-chelating agent BAPTA. RESULTS: Hypoxia inhibited the cell viability in a time-dependent manner. Hypoxia up-regulated the mRNA and protein expression of NHE1, and increased [Ca2+]i and calpain activity. Hypoxia increased the degradation of ABCA1 and amiloride slowed down the ABCA1 degradation. ALLN or BAPTA increased ABCA1 protein level and decreased calpain activity. CONCLUSION: NHE1 inhibitor amiloride attenuates the calpain-mediated degradation of ABCA1, indicating that hypoxia-induced NHE1 might, at least in part, participate in the ABCA1 degradation.  相似文献   

20.
AIMTo investigate the role of soluble Klotho protein in THP-1-derived foam cell formation. METHODSTHP-1 monocytes were induced into macrophages by treatment with 160 nmol/L phorbol myristate acetate for 48 h, and then were divided into 6 groups: negative control group (THP-1-derived macrophages), positive control group [THP-1-derived foam cells induced by oxidized low-density lipoprotein (ox-LDL) for 48 h], and 25, 50, 100 and 200 μg/L soluble Klotho protein groups (THP-1-derived macrophages pretreated with soluble Klotho protein at the indicat?ed concentraions for 2 h and then induced by ox-LDL for 48 h). Lipid droplets in cytoplasm were observed by oil red O staining. The cholesterol outflow rate was detected by scintillation counting technique. The content of intracellular total cholesterol, free cholesterol and cholesterol ester was detected by enzyme fluorescence analysis. The expression of acyl-coenzyme A:cholesterol acyltransferase 1 （ACAT1） and ATP-binding cassette transport?er A1 (ABCA1) at mRNA and protein levels was determined by RT-qPCR and Western blot, respectively. RESULTSOil red O staining and lipid mass quantification showed that THP-1-derived foam cell formation was dose-dependently suppressed by soluble Klotho protein. The cholesterol efflux rate of THP-1-derived foam cells was increased by soluble Klotho protein in a dose-dependent manner (P<0.05). In addition, soluble Klotho protein decreased the expression of ACAT1 and increased the expression of ABCA1 in a dose-dependent manner (P<0.05). CONCLUSION The soluble Klotho protein inhibits THP-1-derived foam cell formation in a dose-dependent manner by down-regulating the expression of ACAT1 and up-regulating the expression of ABCA1.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号