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1.
In order to explore the effect and mechanisms of tumor necrosis factor-α (TNF-α) on the activity of the acyl coenzyme A: cholesteryl acyltransferase (ACAT), THP-1 monocytes were cul- tured and induced to differentiate into macrophages with phorbol ester. TNF-α (60 ng/mL) was added at different time points into the macrophage-containing medium and the ACAT enzyme activity was measured by quantifying the incorporation of 1-14C oleoyl CoA into cholesteryl esters. The expres- sion of ACAT-1 protein and mRNA was respectively detected by Western blotting and RT-PCR in THP-1 macrophages 24 h after treatment with TNF-α (60 ng/mL). The results indicated that ACAT activity in THP-1 macrophages treated with TNF-α was increased in a time-dependent manner. The expression levels of ACAT-1 protein and mRNA were significantly increased in THP-1 macrophages after treatment with TNF-α (P<0.05). It was suggested that TNF-α could increase the activity of ACAT in THP-1 macrophages by up-regulating the expression of ACAT-1 gene.  相似文献   

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Cyclophilin A (CyPA) is abundant in rheumatoid arthritis (RA) synovial fluid and CD147 highly expresses on the monocytes/macrophages cells in RA synovial fluid and synovium. To determine whether CypA can upregulate the expression of matrix metalloproteinase 2 (MMP-2) and MMP-9 in monocytes/macrophages and whether CD 147 facilitates this regulation, human monocyte cell line THP-1 cells were stimulated with CypA. The levels of MMP-2 and MMP-9 mRNA were quantified by quantitative real-time PCR (qRT-PCR), the protein release and activation of MMPs were detected by gelatin zymography and invasion assay. The results showed that CypA significantly increased MMP-9 expression, not MMP-2, in the THP-1 cells. Cyclosporin A (CsA) or HAb18G/CD147 antagonistic peptide AP-9 against CD147 respectively dramatically decreased MMP-2 and MMP-9 expression, both in the absence or presence of CypA. Similar effect of CypA on MMP-9 production was observed in monocytes/macrophages derived from RA patients' synovial fluid. These findings suggest that CD147 facilitates CypA-induced MMP-9 expression in monocytes/macrophages, which may contribute to the destruction of cartilage and bone in RA.  相似文献   

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The relation between the expression and activity of MMP-9 in C-reactive protein (CRP)-induced human THP-1 mononuclear cells and the activation of nuclear factor kappa-B (NF-κB) was studied to investigate the possible role of CRP in plaque destabilization. Human THP-1 cells were incubated in the presence of CRP at 0 (control group), 25, 50 and 100 μg/mL (CRP groups) for 24 h. In PDTC (a specific NF-κB inhibitor) group, the cells were pre-treated with PDTC at 10 μmol/L and then with 100 μg/mL CRP. The conditioned media (CM) and human THP-1 cells in different groups were harvested. MMP-9 expression in CM and human THP-1 cells was measured by ELISA and Western blotting. MMP-9 activity was assessed by fluorogenic substrates. The expression of NF-κB inhibitor α (IκB-α) and NF-κB p65 was detected by Western blotting and ELISA respectively. The results showed that CRP increased the expression and activity of MMP-9 in a dose-dependent manner in the human THP-1 cells. Western blotting revealed that IiB-α expression was decreased in the cells with the concentrations of CRP and ELISA demonstrated that NF-κB p65 expression in the CRP-induced cells was increased. After pre-treatment of the cells with PDTC at 10 μmol/L, the decrease in IκB-α expression and the increase in NF-κB p65 expression in the CRP-induced cells were inhibited, and the expression and activity of MMP-9 were lowered too. It is concluded that increased expression and activity of MMP-9 in CRP-induced human THP-1 cells may be associated with activation of NF-κB. Down-regulation of the expression and activity of MMP-9 may be a new treatment alternative for plaque stabilization by inhibiting the NF-κB activation.  相似文献   

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Objective: To investigate the changes of cyclin L2(CCNL2) gene mRNA and protein during the differentiation of P19 cells to cardiac myocytes, and to explore the relationship between CCNL2 gene and the differentiation of cardiac myocytes. Methods: P19 cells were cultured with 0.9% DMSO for 18 days. Western blots of cardiac troponin I (cTnI) were used to identify cell differentiation. Total RNA was extracted from P19 cells during the process of differentiation at various time points:pre-differentiation(Day 0), and Day 1 to Day 18. The expression levels of CCNL2 gene mRNA and protein were evaluated by RT-PCR and Western blot, respectively. Results: After being induced to differentiate by DMSO for 4 days in suspension, spontaneously and rhythmically beating cells were seen at 8 day, which were cTnI-positive. In P19 cells, both the expression level of CCNL2 gene mRNA and protein were gradually down-regulated. Conclusion: Both the expression of CCNL2 gene and protein were down-regulated during the process of the differentiation of P19 cells into cardiac myocytes, suggesting a possible role for this cyclin in their differentiation.  相似文献   

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Mitofusin2 (Mfn2) plays a pivotal role in the proliferation and apoptosis of vascular smooth muscle cells (VSMCs). The purpose of this study was to investigate the effects of Mfn2 on the trafficking of intracellular cholesterol in the foam cells derived from rat VSMCs (rVSMCs) and also to investigate the effects of Mfn2 on the expression of adenosine triphosphate-binding cassette subfamily A member 1 (ABCA1), adenosine triphosphate-binding cassette subfamily G member 1 (ABCG1) and peroxisome proliferator-activated receptor gamma (PPARγ). The rVSMCs were co-cultured with oxidized low density lipoprotein (LDL, 80 μg/mL) to produce foam cells and cholesterol accumulation in cells. Before oxidized LDL treatment, different titers (20, 40 and 60 pfu/cell) of recombinant adenovirus containing Mfn2 gene (Adv-Mfn2) were added into the culture medium for 24 h to transfect the Mfn2 gene into the rVSMCs. Then the cells were harvested for analyses. The protein expression of Mfn2 was significantly higher in Adv-Mfn2-transfected group than in untransfected group (P<0.05), and the expression levels significantly increased when the titer of Adv-Mfn2 increased (P<0.05). At 24 or 48 h after oxidized LDL treatment, rVSMCs became irregular and their nuclei became larger, and their plasma abounded with red lipid droplets. However, the number of red lipid droplets was significantly decreased in Adv-Mfn2-transfected group as compared with untransfected group. At 48 h after oxidized LDL treatment, the intracellular cholesterol in rVSMCs was significantly increased (P<0.05), but it was significantly decreased in Adv-Mfn2-transfected group as compared with untransfected group (P<0.05), and it also significantly decreased when the titer of Adv-Mfn2 increased (P<0.05). The mRNA and protein expression levels of ABCA1 and ABCG1 were significantly increased in Adv-Mfn2-transfected group as compared with untransfected group (P<0.05). Though the mRNA and protein expression levels of PPARγ was not significantly increased (P>0.05), the phosporylation levels of PPARγ were significantly decreased in Adv-Mfn2-transfected group as compared with untransfected group (P<0.05). These results suggest that the transfection of Adv-Mfn2 can significantly reduce intracellular cholesterol in oxidized LDL-induced rVSMCs possibly by decreasing PPARγ phosporylation and then increasing protein expression levels of ABCA1 and ABCG1, which may be helpful to suppress the formation of foam cells.  相似文献   

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Objective To investigate the pro-apoptotic effect of scFv-mediated delivery of caspase-6 fusion protein on osteosarcoma E 10 cells. Methods The expression of human epidermal growth factor receptor-2 (Her-2) in osteosarcoma cell line E10 was examined by flow cytometry analysis. ScFv-mediated delivery of caspase-6 was generated by sequential fusion of the genes of a signal peptide, a single-chain Her-2 antibody (e23sFv), a PEA translocation domain (PEA aa253-264), and an recombinant caspase-6. The pCMV-immunocaspase-6 was produced by cloning above mentioned fusion genes into pCMV plasmid, and then pCMV-immunocaspase-6 plasmid mixed cationic liposome was transfected into E10 cells. The expression of fusion gene on transfected E10 cells was detected by immunocytochemical staining, The pro-apoptotic effects of fusion gene expression on morphology and growth status of E10 cells were observed by trypan blue cell staining, electron microscopy and MTT assay. Results The fusion protein was detected in the cytoplasm of the transfected E10 cells. These cells presented typical characteristics of apoptosis as detected by electron microscopy. MTT assay revealed that the proliferation of transfected E10 cells was suppressed than that of non- or mock-transfected cells (P〈0.01). Conclusion ScFv-mediated delivery of caspase-6 fusion protein can induce apoptosis of Her-2 positive osteosarcoma E10 cells, suggesting the potential of this strategy for the treatment of human high-grade osteosarcoma.  相似文献   

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In order to construct plasmid of hypoxia-inducible factor-lalpha (HIF-1α), and transfect into human lung cancer cells A549, the change in sensitivity of lung cancer cells A549 to chemotherapy was observed. HIF-1α mRNA structure region was amplified by RT-PCR and inserted into plasmid pcDNA3. The expression plasmid pcDNA3/HIF-1α was transfected into A549 with LipofectAMINE^TM2000. The expression of HIF-1α protein was detected by Western blot. After A549 cells were transfected with HIF-1α prior to addition of 5-Fu, the growth activity was measured by growth curve, apoptosis was detected by flow cytometry at 48 h, and the levels of caspase3 and MDR-1 were determined by Western blot. The results showed that the constructed expression plasmid was analyzed with restriction enzymes and gel electrophoresis. Two DNA lanes at 2.55 kb and 5.4 kb respectively were found, which were consistent with that expected. The growth rate in 5-Fu group was significantly inhibited, and the apoptosis index and caspase3 activity were increased significantly as compared with control group. After HIF-1α being transfected into A549, the activity of MDR-1 was increased and the effect of 5-Fu was weakened. In conclusion, HIF-1α can promote chemoresistance by increasing the activation of MDR1 and suppressing apoptosis during lung cancer cells A549 in- duced with 5-Fu.  相似文献   

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目的研究低密度脂蛋白(LDL)氧化对人单核细胞源巨噬细胞Toll样受体-4(TLR-4)表达的影响及其机制。方法用RPM I 1640培养基体外培养人THP-1单核细胞系,加入佛波醇肉豆蔻酸乙酸酯(PMA)培养48 h使其分化为巨噬细胞,加入氧化低密度脂蛋白(Ox-LDL)或LDL,用免疫细胞化学、蛋白质免疫印迹和反转录聚合酶链反应(RT-PCR)方法,观察脂蛋白氧化前、后对巨噬细胞表达TLR-4蛋白及TLR-4 mRNA的影响。结果Ox-LDL可提高TLR-4蛋白及TLR-4 mRNA的表达(P<0.01);而LDL对TLR-4蛋白及其mRNA的表达无影响(P<0.05)。结论LDL的氧化可能促进THP-1源巨噬细胞TLR-4转录水平的上调,导致蛋白质的合成增加;Ox-LDL可能是动脉粥样硬化中炎症的始发原因之一。  相似文献   

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目的观察细胞外基质金属蛋白酶诱导因子(EMMPRIN)在单核向巨噬和泡沫细胞分化过程中的表达变化。方法体外诱导THP-1单核细胞分化为巨噬和泡沫细胞,应用Real-time RT-PCR和Western blot测定EMMPRIN基因和蛋白表达。结果单核细胞分化为巨噬细胞后EMMPRIN mRNA和蛋白表达均显著增加,当进一步分化为泡沫细胞时,EMMPRIN的表达与巨噬细胞比较无显著性差异。结论单核细胞向巨噬细胞的分化诱导EMMPRIN表达,而进一步向泡沫细胞分化对其表达无影响。  相似文献   

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目的研究单核细胞在向巨噬细胞、泡沫细胞分化过程中基质金属蛋白酶-9(MMP-9)基因和蛋白表达的变化。方法体外诱导人单核细胞系(THP-1)细胞株分化为巨噬细胞和泡沫细胞,采用荧光定量聚合酶链式反应和Western blotting分别检测单核细胞向巨噬细胞、泡沫细胞分化过程中MMP-9基因和蛋白表达的变化。结果THP-1单核细胞向巨噬细胞、泡沫细胞分化过程中MMP-9 mRNA表达量分别增加了2.03倍和3.36倍(P<0.05,P<0.01);蛋白表达分别增加了5.86倍和3.68倍(P<0.01,P<0.05)。巨噬细胞和泡沫细胞中的MMP-9 mRNA水平无明显差异(P>0.05),但泡沫细胞中蛋白表达量较巨噬细胞有显著减少(P<0.05)。结论经体外诱导分化成的巨噬细胞和泡沫细胞中MMP-9 mRNA、蛋白水平与单核细胞比较呈显著增加,但单核细胞分化为泡沫细胞后其蛋白表达量呈显著下降。  相似文献   

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目的研究单核细胞向泡沫细胞诱导分化过程中脂酰CoA胆固醇酯酰转移酶-1(ACAT-1)表达及活性的变化。方法复苏、培养人单核细胞株THP-1细胞,与乙酸肉豆蔻佛波酯(PMA)、PMA+氧化低密度脂蛋白(ox-LDL)共孵育1~4 d,RT-PCR方法检测单核细胞分化过程中ACAT-1 mRNA表达,Westernblotting检测ACAT-1蛋白表达的变化。结果(1)单核细胞复苏后加入PMA诱导48 h后,分化为巨噬细胞。经PMA+ox-LDL诱导24 h后分化为泡沫细胞。(2)与无血清培养单核细胞对照组比较,在PMA诱导单核细胞株THP-1向巨噬细胞分化过程中,ACAT-1 mRNA、蛋白表达及酶活性水平明显增高(P<0.05),呈时间依赖效应。(3)巨噬细胞向泡沫细胞分化过程中,ACAT-1 mRNA、蛋白表达及酶活性水平增高,呈时间依赖效应。但和无血清培养巨噬细胞比较差异无统计学意义(P>0.05)。结论单核细胞株THP-1经PMA,PMA/ox-LDL诱导后,可分化为巨噬细胞、泡沫细胞。ACAT-1的表达及活性增高在单核细胞向泡沫细胞诱导分化过程中起着重要作用。  相似文献   

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目的观察白细胞介素-12(IL-12)预刺激在牙龈卟啉单胞菌脂多糖(P.gingivalis LPS)促泡沫细胞形成过程中对细胞因子的影响。方法用氧化低密度脂蛋白(oxLDL)将人THP-1单核细胞来源的巨噬细胞诱导48h形成泡沫细胞。在巨噬细胞和泡沫细胞培养液中分别加入IL-12作用2h后,巨噬细胞培养液中加入oxLDL和P.gingivalisLPS,泡沫细胞培养液中加入P.gingivalis LPS。使用ELISA法检测培养液上清中IL-1β和肿瘤坏死因子-α(TNF-α)的水平,实时定量PCR检测细胞内IL-1β、IL-10、IL-12和IL-18mRNA的转录水平。结果在泡沫细胞形成过程中,IL-12预刺激可以降低培养液上清内TNF-α水平。降低细胞内IL-10和IL-12mRNA转录水平;泡沫细胞受P.gingivalisLPS刺激过程中,IL-12预刺激可以增加培养液上清IL—1β水平。减少细胞内IL-18mRNA的转录水平,增加IL-10mRNA的转录水平。结论IL-12预刺激影响P.gingivalisLPS促泡沫细胞形成过程中炎症细胞因子的转录和分泌。  相似文献   

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PMA促进人单核细胞分化及ACAT1基因表达   总被引:1,自引:0,他引:1  
目的研究人单核细胞系在佛波酯(PMA)作用下分化为巨噬细胞的过程中酰基CoA:胆固醇酰基转移酶1(ACAT1)活性的改变及其机制。方法体外培养人THP-1单核细胞系,PMA作用使其分化为巨噬细胞。以放射性同位素标记底物法检测ACAT1活性.用Western blot法和RT—PCR法分别检测ACAT1蛋白和mRNA。结果PMA使THP-1单核细胞的形态和生长状态巨噬细胞化.在此过程中ACAT1 mRNA和蛋白明显增加(P〈0.01),酶活性升高(P〈0.05)。结论PMA可促进单核细胞分化为巨噬细胞,上调ACAT1基因的表达,促进酶活性提高。  相似文献   

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目的:观察内脂素(visfatin)诱导人类单核细胞白血病细胞株THP-1源性泡沫细胞形成中过氧化物酶体增殖物激活受体γ(PPARγ)的表达作用。方法:给予不同浓度的visfatin处理THP-1源性巨噬细胞,并加入低密度脂蛋白(LDL)孵育24 h后,运用油红O染色观察细胞内脂滴的变化,运用逆转录聚合酶链反应和Western-blot检测PPARγ的mRNA和蛋白表达水平。结果:高浓度的visfatin刺激负荷LDL的THP-1源性巨噬细胞24 h后,细胞质内的脂滴明显增多。visfatin呈浓度依赖性的下调负荷LDL的THP-1源性巨噬细胞中PPARγmRNA和蛋白表达(P<0.05)。结论:visfatin对THP-1源性泡沫细胞形成中PPARγ表达水平的下调,这可能在动脉粥样硬化的发生发展起重要作用。  相似文献   

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目的研究不同浓度厄贝沙坦对血管紧张素Ⅱ(AngⅡ)诱导的人单核/巨噬细胞系(THP-1)凝集素样氧化低密度脂蛋白受体(LOX-1)mRNA和蛋白表达的影响,并探讨其可能的机制。方法 THP-1细胞经0.16μmoL/L佛波酯诱导分化后,将细胞分为3组:对照组、AngⅡ组、厄贝沙坦干预组,干预组分别加入不同浓度厄贝沙坦孵育2 h后,再加入AngⅡ1×10-6moL/L孵育24 h,用荧光定量PCR和细胞酶联免疫法检测(LOX-1)mRNA和蛋白表达。结果与对照组比较,Ang II可明显上调THP1细胞(LOX-1)mRNA和蛋白表达,差异有统计学意义(P<0.05)。不同浓度厄贝沙坦均能抑制(LOX-1)蛋白表达(P<0.05),并且随着厄贝沙坦浓度降低,抑制作用减低,即两者呈浓度依赖性。结论厄贝沙坦以浓度依赖方式抑制AngⅡ诱导的THP1细胞(LOX-1)mRNA和蛋白表达,减少巨噬细胞通过(LOX-1)途径的氧化低密度脂蛋白(oxLDL)摄入,影响泡沫细胞的发生、发展,发挥其抗动脉粥样硬化(AS)作用。  相似文献   

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目的观察脂肪因子Chemerin是否调节胆固醇流出和巨噬泡沫细胞脂滴蓄积,以及对巨噬泡沫细胞ATP结合盒转运子A1(ATP-binding cassette transporter A1,ABCA1)和酰基辅酶A:胆固醇酰基转移酶-1(Acyl-CoA:choles-terol acyltransferase-1,ACAT1)表达和NF-κB活化的影响。方法佛波酯(phorbol myristate acetate,PMA)诱导THP-1单核细胞分化为巨噬细胞,随后加入胆固醇和ox-LDL培养促进巨噬细胞转化为巨噬泡沫细胞,免疫荧光染色检测巨噬细胞表面抗原CD68的表达,油红O染色后观察泡沫细胞形态,脂肪因子Chemerin干预巨噬泡沫细胞,应用液体闪烁计数仪检测胆固醇流出变化,油红O染色观察细胞内脂滴变化,实时PCR和Western blot检测ABCA1及ACAT1mR-NA和蛋白表达水平。Sandwich ELISA法检测巨噬泡沫细胞NF-κB活化情况。实时PCR检测NF-κB抑制剂四氢化吡咯二硫代氨基甲酸酯(PDTC)预处理后,Chemerin再干预时ABCA1表达的变化。结果 Chemerin抑制巨噬细胞内胆固醇流出,促进脂滴蓄积,下调ABCA1mRNA和蛋白的表达,增加NF-κB活化,差异有统计学意义(均P<0.05),且ABCA1mRNA表达与Chemerin浓度呈负相关,r=-0.936(P<0.05),NF-κB活化程度与ABCA1mRNA表达呈负相关,r=-0.917(P<0.05),但Chemerin对ACAT1mRNA和蛋白的表达无明显影响,PDTC预处理能够逆转ABCA1mRNA表达抑制。结论 Chemerin下调ABCA1mRNA和蛋白的表达,抑制THP-1巨噬泡沫细胞内胆固醇外流,增加细胞内脂滴蓄积,NF-κB活化可能是Chemerin抑制ABCA1mRNA表达的信号通路之一。  相似文献   

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