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1.
奥曲肽抑制肝星状细胞增殖及细胞外基质合成   总被引:2,自引:0,他引:2       下载免费PDF全文
目的:探讨奥曲肽对肝星状细胞(HSC)增殖与细胞外基质(ECM)合成的影响。方法:采用胶原酶二步原位灌注法分离、培养大鼠HSC,并分别给予转化生长因子1(TGFβ1)(2.5μg·L-1)、奥曲肽(Oct)(0.01-10μg·L-1)或TGFβ1(2.5μg·L-1)+Oct(0.01-10mg·L-1)干预,分别用MTT法、[3H]-TdR和[3H]-脯氨酸掺入法及放射免疫法检测各处理组HSC增殖及ECM合成水平。结果:Oct能不同程度抑制HSC[3H]-TdR掺入和增殖;能够显著抑制体外培养HSC[3H]-脯氨酸掺入,降低上清液透明质酸(HA)、层粘连蛋白(LN)和IV型胶原(CIV)水平;TGFβ1能够诱导HSC表达ECM上调,Oct能够阻断TGFβ1对HSC的调控作用。结论:Oct能够有效地抑制HSC增殖及ECM合成与分泌。  相似文献   

2.
目的:检测本实验室构建的表达人细胞色素P450 3A4同功酶转基因细胞系CHL-3A4的硝苯吡啶氧化酶活性。方法:利用多药耐药细胞K562r的阿霉素(ADR)耐药性可被硝苯吡啶逆转,而硝苯吡啶又可特异地被CYP3A4代谢,观察硝苯吡啶在CHL-3A4 S9混合物 (S9 mix) 中孵育前后的生物学活性变化来判断CHL-3A4细胞的CYP3A4硝苯吡啶氧化酶活性。结果:K562r细胞在含有硝苯吡啶(NIF) (12.5 μg·L-1)的培养基中培养时,对阿霉素的IC50值从不含NIF时的(6.47±0.60) mg·L-1降至(0.89±0.15) mg·L-1(P<0.01)。K562r细胞在含有分别经CHL-3A4、CHL细胞的S9组分和灭活的CHL-3A4细胞的S9组分预处理的NIF(12.5 μg·L-1)的培养基中培养时,阿霉素对其的IC50值分别为(6.10±0.50) mg·L-1、(0.32±0.09) mg·L-1和(0.32±0.04) mg·L-1。前者和后两者相比P<0.01。 结论:实验室构建的表达人细胞色素P450 3A4同功酶转基因细胞系CHL-3A4具有硝苯吡啶氧化酶活性,从而进一步确证其表达产物为人CYP3A4同功酶。并为今后检测CYP同功酶活性提供了一种新的途径。  相似文献   

3.
目的:探讨西红花酸对过氧化氢(H2O2)诱导的培养心肌细胞凋亡及相关调控蛋白caspase-3、Bcl-2表达改变的作用。 方法: 通过光镜观察细胞形态、碘化丙啶(PI)染色法和流式细胞术相结合检测培养细胞凋亡率、免疫荧光染色法和流式细胞术相结合检测细胞中caspase-3、Bcl-2蛋白。 结果: 在本实验使用浓度范围内,各浓度H2O2组细胞形态明显改变、凋亡率明显高于正常对照组,1×10-4 mol·L-1 H2O2可使培养心肌细胞Bcl-2蛋白表达明显减少,而caspase-3表达明显增多;各剂量西红花酸组细胞形态学改变减少、凋亡率明显低于1×10-4 mol·L-1 H2O2组,细胞中Bcl-2蛋白减少幅度与caspase-3增加幅度均减小,且较高浓度(5×10-5 mol·L-1)西红花酸组比较低浓度(5×10-7 mol·L-1)西红花酸组作用也更明显(P<0.05)。 结论: 西红花酸能够减轻H2O2对培养心肌细胞的损伤性凋亡作用,可能与稳定细胞内凋亡相关调控蛋白caspase-3、Bcl-2的功能有关。  相似文献   

4.
OPN促进大鼠肝星状细胞黏附、迁移及黏着斑激酶活性   总被引:1,自引:1,他引:0  
目的探讨细胞外间质(ECM)成分骨桥蛋白(OPN)和精-甘-天冬-丝氨酸(Arg-G ly-Asp-Ser,RGDS)四肽对大鼠肝星状细胞(HSCs)黏附、迁移与黏着斑激酶(FAK)活性的影响。方法应用体外细胞培养技术,MTT法检测HSCs增殖,甲苯胺蓝法检测HSCs黏附情况,并观察HSCs迁移;采用免疫沉淀和W estern b lot技术测定黏着斑激酶活性变化。结果①不同浓度OPN和RGDS四肽作用于HSCs 2 h后,8、16、32 mg/L OPN组细胞黏附促进率均高于对照组(P<0.05);25 mg/L~100 mg/L RGDS四肽不同浓度组细胞黏附率明显下降(P<0.05)。②不同浓度OPN干预细胞48 h后,促进HSCs增殖,而RGDS四肽组抑制HSCs增殖。③16 mg/L OPN作用12、24和36 h,细胞迁移距离显著高于对照组(P<0.05);而100 mg/L RGDS四肽组则显著性低于对照组(P<0.05)。④经OPN作用后各浓度组HSCs中磷酸化FAK均有显著表达;RGDS四肽干预后,磷酸化FAK表达量降低。结论①OPN促进HSCs增殖、黏附和迁移;RGDS四肽对HSCs增殖、黏附和迁移具有抑制作用。②OPN可以诱导FAK活化,RGDS四肽可抑制磷酸化FAK的表达。  相似文献   

5.
目的:研究甲基莲心碱(Nef)逆转耐长春新碱人胃癌细胞多药耐药性(MDR)的作用及机制。方法:采用噻唑蓝(MTT)比色法检测长春新碱(VCR)的细胞毒性;PI染色流式细胞计数测定VCR诱导细胞凋亡;间接免疫荧光流式细胞术检测细胞P-gp和MRP的表达。结果:Nef(5、10μmol·L-1)对人胃癌细胞(SGC7901)和耐长春新碱人胃癌细胞(SGC7901/VCR)无显著毒性作用,VCR对敏感株SGC7901的IC50为0.06mg·L-1,而对MDR细胞株SGC7901/VCR的IC50为2.32mg·L-1,SGC7901/VCR较SGC7901对VCR耐药39倍,Nef(2.5、5、10μmol·L-1)能使VCR对SGC7901/VCR细胞的IC50从2.32mg·L-1依次下降至0.34、0.12、0.05mg·L-1,逆转倍数分别为6.8、18.1、43.8。Nef(2.5、5、10μmol·L-1)能降低SGC7901/VCR细胞对VCR的凋亡抗性,其作用强于维拉帕米(VRP)。SGC7901/VCR细胞较SGC7901细胞高表达P-gp、MRP,Nef(10μmol·L-1)处理24h后,SGC7901/VCR细胞P-gp、MRP的表达明显低下。结论:Nef具有逆转耐长春新碱人胃癌细胞的MDR作用,其作用机理与下调P-pg和MRP表达有关。  相似文献   

6.
目的: 研究丹参单体IH764-3对H2O2刺激的肝星状细胞(HSCs)凋亡的诱导作用以及此过程中粘着斑激酶(FAK)的变化。方法: 通过直接细胞计数法测定HSCs增殖;光学显微镜及透射电镜技术观察凋亡细胞的形态学改变,并应用膜联蛋白(Annexin-V)/碘化丙啶(PI)联合标记法检测HSCs的凋亡率;运用RT-PCR方法观察FAKmRNA表达。结果: H2O2具有刺激HSCs增殖的作用;丹参单体IH764-3能够诱导H2O2刺激的HSCs凋亡,并呈剂量依赖关系:10mg/L、20mg/L、30mg/L及40mg/LIH764-3干预48h后各组凋亡率分别为6.35%、9.28%、15.10%、19.69%,而H2O2组为2.30%;30mg/LIH764-3干预HSCs不同时间(12h、24h、48h)的凋亡率分别是6.73%、10.34%、15.10%,呈时间依赖关系;RT-PCR分析表明FAK基因表达强度在加入IH764-3后2h即明显下调,10mg/L,20mg/L,30mg/L及40mg/L组分别比H2O2组低了68.71%、71.00%、86.72%、95.16%。结论: 丹参单体IH764-3可以诱导H2O2刺激的HSCs凋亡,下调FAKmRNA表达是其诱导HSCs凋亡的机制之一。  相似文献   

7.
目的:探讨肝硬化大鼠肝缺血/再灌注(I/R)损伤是否与肝细胞凋亡相关及天冬氨酸特异性半胱氨酸蛋白酶-3(caspase-3)活性变化与肝细胞凋亡的关系。方法:Pringle法复制肝I/R模型,将肝硬化大鼠随机分为2组:A组:单纯肝门阻断;B组:血流阻断+抑制剂:N-苯甲基氧化碳酰-缬氨酸-丙氨酸-天冬氨酸-氟化丙酮(ZVAD-fmk)15mg/kg;取无肝硬化大鼠,作单纯肝门阻断为C组。各组肝门阻断时间均为30min,再灌注72h。比较3组的血清天冬氨酸转氨酶(AST)、肝组织的caspase-3活性和肝细胞凋亡数。结果:A组大鼠肝组织caspase-3活性、肝细胞凋亡数在再灌注后6h达高峰,分别为(18.1±1.8)μmolAMC·h-1·g-1(tissue)和20.9%±4.9%,与I/R前的(6.6±2.0)μmolAMC·h-1·g-1(tissue)和0.5%±0.3%相比,P<0.01。肝细胞凋亡数、caspase-3的活性随灌注时间的延长而减低,两者随时间的变化一致。3组中A组肝损伤最严重,表现为再灌注后6h血清AST最高,与B、C组比较有显著差异,大鼠7d生存率只为62.5%。进一步研究表明,再灌注后6h,A组的肝组织caspase-3活性、肝细胞凋亡数亦明显比B、C组高。结论:肝细胞凋亡是肝硬化大鼠肝I/R损伤的主要病理改变。肝细胞凋亡的发生可能主要依赖于肝组织caspase-3活性的改变,抑制caspase-3能明显减轻肝I/R损伤。肝硬化肝脏比无硬化肝脏对缺血损伤敏感性高的病理机制与依赖caspase-3的肝细胞凋亡密切相关。  相似文献   

8.
目的:对interleukin-1β(IL-1β)诱导人黑色素瘤A375-S2细胞凋亡的信号转导途径进行研究。方法:使用倒置显微镜观察细胞形态学变化。通过MTT法测定IL-1β对A375-S2细胞的抑制作用以及细胞内半胱氨酸蛋白酶(caspases)与这种作用的关系。利用乳酸脱氢酶(LDH)测定法对IL-1β作用后细胞的损伤情况进行分析。琼脂糖凝胶电泳法检测IL-1β对细胞DNA降解的影响。结果: IL-1β对A375-S2细胞的抑制作用呈剂量和时间依赖性,在10-9mol/L作用72 h时达到90%以上。caspase-1、-3、-8、-9和caspase-10的抑制剂能够部分抑制IL-1β早期诱导的细胞凋亡。 LDH活力测定显示,在IL-1β诱导的细胞死亡过程中,凋亡占主导地位,并呈现剂量和时间依赖性 。细胞经过10-11mol/L IL-1β处理72 h后,出现凋亡典型的DNA梯状条带,与上述结果一致。 结论: IL-1β能够诱导人黑色素瘤A375-S2细胞凋亡,这种作用可能依赖于激活一类介导凋亡的caspase家族蛋白酶。  相似文献   

9.
目的:应用黏着斑激酶相关非激酶(FRNK)表达质粒瞬时转染肝星状细胞(HSCs),探讨FRNK选择性抑制黏着斑激酶(FAK)磷酸化对FN刺激的HSCs凋亡的影响。方法:在体外培养HSCs,以FN刺激HSCs增殖,采用脂质体介导的方法进行FRNK表达质粒转染。应用膜联蛋白(Annexin-V)/碘化丙啶(PI)双标记流式细胞术、DNA凝胶电泳技术和透射电镜技术检测细胞的凋亡,Western blotting及RT-PCR方法检测FRNK、FAK、p-FAK(Tyr397)、caspase-3蛋白及其mRNA表达。结果:FRNK表达质粒成功转染HSCs,在翻译后水平抑制FAK磷酸化;FRNK表达质粒转染HSCs 48 h后,细胞凋亡率增加,与空质粒组之间有显著差异[(25.37±1.92)% vs(9.28±1.05)%],P<0.01,伴随caspase-3在翻译和转录水平的增高[(264.17±12.60 vs 185.82±9.69),P<0.01;(4.19±0.48 vs 1.07±0.27),P<0.01]。结论:在脂质体介导下瞬时转染FRNK表达质粒,可使外源性的FRNK在HSCs内大量表达,在翻译后水平抑制FAK磷酸化;可以诱导FN刺激的HSCs发生凋亡。  相似文献   

10.
光敏化促进姜黄素诱导人胃癌MGC-803细胞凋亡   总被引:1,自引:1,他引:0  
目的: 探讨光敏化促进姜黄素诱导人胃癌MGC-803细胞凋亡及其机制。方法: 用MTT法检测光敏化姜黄素对胃癌MGC-803细胞株的增殖抑制率,Hoechst 33258荧光染色观察细胞核形态的变化,流式细胞术检测细胞的凋亡率、线粒体膜电位、细胞内活性氧和Ca2+;比色法检测caspase-3、8和9酶活性;Western blotting分析细胞色素C、Bcl-2、Bax和热休克蛋白70(HSP70)水平。结果: 单纯姜黄素(5.0μmol/L)对MGC-803细胞增殖抑制率为(29.74±2.30)%,在光学显微镜下可见部分凋亡细胞,凋亡率为(12.54±1.75)%。而光敏化姜黄素组细胞增殖抑制率则为(44.93±3.61)%,在光学显微镜下能见明显细胞核形态改变,染色质凝集,凋亡小体形成,凋亡率为(26.58±2.67)%,细胞周期主要阻滞于G0/G1期。光敏化姜黄素显著降低线粒体膜电位,显著增加细胞色素C、细胞内活性氧和Ca2+以及caspase-3、8和9酶活性,与单纯姜黄素组比较,差异显著(P<0.01)。Western blotting结果显示光敏化姜黄素同时显著抑制Bcl-2和HSP70蛋白表达水平。结论: 光敏化姜黄素通过Bcl-2和线粒体途径增强其诱导胃癌MGC-803细胞凋亡的作用。  相似文献   

11.
A major cause of implant failure in skeletal tissues is failure of osseointegration, often due to lack of adhesion of cells to the titanium (Ti) alloy interface. Since arginine-glycine-aspartic acid (RGD)-containing peptides have been shown to regulate osteoblast adhesion, we tested the hypothesis that, bound to a Ti surface, these peptides would promote osteoblasts differentiation, while at the same time inhibit apoptosis. RGDS and RGES (control) peptides were covalently linked to Ti discs using an APTS linker. While the grafting of both RGDS and RGES significantly increased Ti surface roughness, contact angle analysis showed that APTS significantly increased the surface hydrophobicity; when the peptides were tethered to Ti, this was reduced. To evaluate attachment, MC3T3-E1 osteoblast cells were grown on these discs. Significantly more cells attached to the Ti-grafted RGDS then the Ti-grafted RGES control. Furthermore, expression of the osteoblasts phenotype was significantly enhanced on the Ti-grafted RGDS surface. When cells attached to the Ti-grafted RGDS were challenged with staurosporine, an apoptogen, there was significant inhibition of apoptosis; in contrast, osteoblasts adherent to the Ti-grafted RGES were killed. It is concluded that RGD-containing peptides covalently bonded to Ti promotes osteoblasts attachment and survival with minimal changes to the surface of the alloy. Therefore, such modifications to Ti would have the potential to promote osseointegration in vivo.  相似文献   

12.
The involvement of integrins in phagocyte spreading and phagocytosis was investigated in the compound ascidian Botryllus schlosseri. The number of spreading cells was significantly reduced when adhesion occurred in the presence of the tetrapeptide Arg--Gly--Asp--Ser (RGDS), but not of Arg--Gly--Glu--Ser (RGES) indicating the involvement of RGD-mediated adhesion mechanisms in phagocyte spreading. The significant decrease of the fraction of spreading cells in the presence of Botryllus blood plasma suggests the presence of RGD-containing molecules in the blood of our species. The increase in the same index when blood plasma-coated slides as well as fibrinogen- and fibronectin-coated coverslips were used, fits with the above hypothesis. Adhesion in the presence of RGDS leads to a consistent alteration of the actin cytoskeleton, in agreement with the known role of integrin adhesion in microfilament organization. Phagocytosis was greatly reduced by RGDS in the incubation medium, but not by RGES, and was significantly increased by coating yeast cells with fibronectin or blood plasma. Both spreading and phagocytic capability were severely inhibited by wortmannin, suggesting the importance of phosphatidylinositol-3-kinase in integrin-mediated signal transduction in ascidians.  相似文献   

13.
目的:观察精-甘-天冬-丝氨酸(RGDS)四肽对纤维连接蛋白(FN)刺激的大鼠肝星状细胞(HSC)基质金属蛋白酶-13(MMP-13)及其组织抑制因子(TIMP-1)表达的影响。方法:应用体外细胞培养技术,用RT-PCR检测HSC MMP-13mRNA水平;原位杂交和Western blot技术分别检测上述细胞TIMP-1 mRNA和蛋白水平。结果:RGDS四肽干预2h组MMP-13 mRNA的表达强度明显上调,同时TIMP-1 mRNA表达受抑制;RGDS四肽干预24h组TIMP-1蛋白表达受抑制。结论:RGDS四肽诱导HSC MMP-13表达,抑制其TIMP-1表达是其抗肝纤维化的作用机制之一。  相似文献   

14.
目的:探讨垂体腺苷酸环化酶激活肽Ⅰ型受体(PAC1受体)特异激动剂maxadilan对人脂肪干细胞(adipose-derived stem cells,ASCs)的增殖、凋亡和分化潜能的作用。方法:取人脂肪组织通过酶消化法分离培养ASCs。流式细胞术鉴定ASCs表面标志物,并进行ASCs向成骨成脂定向诱导。CCK-8法和流式细胞术检测maxadilan对ASCs活性的影响。采用波长为254 nm的紫外线(ultraviolet C,UVC)照射ASCs,CCK-8法测定不同剂量的UVC诱导ASCs凋亡后的吸光度。选择剂量为702 J/m2的UVC照射ASCs 24 h后,用流式细胞术和caspase 3和caspase 9试剂盒检测maxadilan对ASCs凋亡的影响。结果:流式细胞术检测表明细胞CD29、CD44、CD59和CD105表面抗原阳性,证实所提取的细胞是ASCs。CCK-8法检测发现80 nmol/L浓度的maxadilan对ASCs促增殖作用最强,流式细胞术分析也证实80 nmol/L maxadilan处理显著促进ASCs的增殖,与对照组比较差异有统计学意义(P0.05)。与仅被702 J/m2UVC照射的ASCs比较,80 nmol/L maxadilan显著抑制同等剂量UVC照射ASCs所诱导的、与caspase 3和caspase 9活性相关的细胞凋亡,2组比较差异有统计学意义(P0.05)。同时,2组细胞成骨和成脂的诱导分化均为阳性。结论:Maxadilan促进ASCs增殖,抑制ASCs凋亡,且不改变细胞向成骨和成脂诱导分化的潜能。Maxadilan有利于ASCs的体外生长与扩增。  相似文献   

15.
This study investigated the dynamic adhesion of endothelial progenitor cells (EPCs) to peptide-grafted poly(ethylene glycol) diacrylate (PEGDA) hydrogels and determined the relative ability of RGDS, REDV and YIGSRG peptides to reduce the velocity of EPC rolling. Circulating EPCs are key mediators of endothelium repair and have been shown to accelerate re-endothelialization, which is important in reducing the incidence of restenosis following stent placement and occlusion of small diameter vascular grafts. However, to exploit these capabilities for tissue engineering applications, more knowledge is needed about EPC binding to the vascular wall under shear and, in particular, whether the incorporation of peptide ligands into biomaterials can support the process of EPC rolling or maintain EPC adhesion. This study specifically examined one type of EPCs endothelial colony forming cells (ECFCs), based on their ability to be expanded in culture and differentiate into mature endothelial cells. The amount of grafted PEG–peptide was shown to be dependent on the concentration of PEG–peptide grafting solution photopolymerized onto the hydrogel surface. The ECFC strength of adhesion on PEG–RDGS grafted hydrogels exceeded 350 dyn cm?2 for 85% of adherent cells. PEG–RGDS grafted hydrogels supported ECFC rolling, whereas ECFC velocity on the negative control PEG–RGES grafted hydrogels and on the “blank slate” PEGDA hydrogels was substantially higher than the cutoff velocity for cell rolling. The ECFC rolling velocity on PEG–RDGS grafted hydrogels depended on the shear rate; as shear rate was increased from 20 s?1 to 120 s?1, ECFC rolling velocity increased from 103 ± 3 μm s?1 to 741 ± 28 μm s?1. REDV and YIGSRG, which are known to preferentially support endothelial cell adhesion, also supported ECFC rolling. Interestingly, the rolling velocity of ECFCs on PEG–REDV grafted hydrogels was significantly lower than on PEG–YIGSRG or on PEG–RGDS grafted hydrogels. Understanding the dynamic adhesion of ECFCs to peptide-grafted hydrogels is the first step towards understanding the similarities and differences of EPCs from mature endothelial cells and improving the ability to sequester EPCs to biomaterial surfaces in order to promote intravascular re-endothelialization.  相似文献   

16.
The putative effects of interleukin (IL)-7, operating in the context of extracellular matrix (ECM), on the adhesion of human T cells were examined. Recombinant human IL-7 was found to bind ECM or fibronectin (FN) with IC50 values of 10–100 nM. Nanogram amounts of both soluble and, especially, FN- or ECM-bound IL-7, which differentially affected the morphologies of FN-adherent T cells, induced the adhesion of resting CD4+ and CD8+ T cells in dose-dependent and β1 integrin-dependent manners. Under static and flow conditions, soluble IL-7 also induced the binding of unstimulated T cells to vascular cell adhesion molecule-1, suggesting that this cytokine can also modulate integrin binding to endothelial cell ligands. The effects of affinity modulation by IL-7 of FN-specific β1 integrins depend on the presence of soluble FN, which inhibited T cell adhesion to FN induced by FN-bound IL-7 or by an integrin-specific affinity-modulating monoclonal antibody, but not by soluble IL-7 or phorbol 12-myristate 13-acetate. These findings provide an example of a major ECM integrin ligand, FN, which is capable of modulating its adhesive interactions with specific immune cells by associating with and presenting a cytokine in a bio-active state.  相似文献   

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