Dihydroartemisinin ameliorates innate inflammatory response induced by Streptococcus suis-derived muramidase-released protein via inactivation of TLR4-dependent NF-kB signaling

Muramidase-released protein(MRP)is now being recognized as a critical indicator of the virulence and pathogenicity of Streptococcus suis(S.suis).However,the identification of viable therapeutics for S.suis infection was hindered by the absence of an explicit mechanism for MRP-actuated inflammation.Dihydroartemisinin(DhA)is an artemisinin derivative with potential anti-inflammatory activity.The modulatory effect of DhA on the inflammatory response mediated by the virulence factor MRP remains obscure.This research aimed to identify the signaling mechanism by which MRP triggers the innate immune response in mouse spleen and cultured macrophages.With the candidate mechanism in mind,we investigated DhA for its ability to dampen the pro-inflammatory response induced by MRP.The innate immune response in mice was drastically triggered by MRP,manifesting as splenic and systemic inflammation with splenomegaly,immune cell infiltration,and an elevation in pro-inflammatory cytokines.A crucial role for Toll-like receptor 4(TLR4)in coordinating the MRP-mediated inflammatory response via nuclear factor-kappa B(NF-kB)activation was revealed by TLR4 blockade.In addition,NFkB-dependent transducer and activator of transcription 3(STAT3)and mitogen-activated protein kinases(MAPKs)activation was required for the inflammatory signal transduction engendered by MRP.Intriguingly,we observed an alleviation effect of DhA on the MRP-induced immune response,which referred to the suppression of TLR4-mediated actuation of NF-kB-STAT3/MAPK cascades.The inflammatory response elicited by MRP is relevant to TLR4-dependent NF-kB activation,followed by an increase in the activity of STAT3 or MAPKs.DhA mitigates the inflammation process induced by MRP via blocking the TLR4 cascade,highlighting the therapeutic potential of DhA in targeting S.suis infection diseases.

Relationship between Methylation Status of Multi-drug Resistance Protein(MRP) and Multi-drug Resistance in Lung Cancer Cell Lines

Objective： To study the relationship between the methylation status of multi-drug resistance protein （MRP） gene and the expression of its mRNA and protein in lung cancer cell lines. Methods： Human embryo lung cell line WI-38, lung adenocarcinoma cell line SPCA-1 and its drug-resistant cells induced by different concentrations of doxorubicin were treated with restriction endonuclease Eco47III. The methylation status of MRP was examined by PCR, and the expressions of its mRNA and protein were evaluated by in situ hybridization and immunohistochemistry. Results： MRP gene promoter region of WI-38 cells was in hypermethylation status, but the promoter region of MRP in SPCA-1 cells and their resistant derivatives induced by different concentrations of doxorubicin were in hypomethylation status. There were significant differences in the expression of MRP mRNA among WI-38 cell line, SPCA-1 cells and their drug-resistant derivatives induced by different concentration of doxorubicin. Consistently, MRP immunostaining presented similar significant differences. Conclusion： The promoter region of MRP in SPCA-1 lung adenocarcinoma cells was in hypomethylation status. The hypomethylation status of 5＇ regulatory region of MRP promoter is an important structural basis that can increase the activity of transcription and results in the development of drug resistance in lung cancer.

EXPRESSION OF MULTIDRUG RESISTANCE-ASSOCIATED PROTEIN (MRP) AND ITS RELATIONSHIP WITH CLINICOPATHOLOGICAL FACTORS IN NON-SMALL CELL LUNG CANCER

Objective: To investigate the relationship between the expression of multidrug resistance-associated protein (MRP) and clinicopathological factors and prognosis. Methods: The expression of MRP in 62 cases with non-small cell lung cancer (NSCLC) was detected using immunohistochemistry method. The expression of MRP in 30 cases of NSCLC and corresponding normal lung tissues were detected using immunohistochemistry and Western Blot. Results: this study of tumor tissues confirmed the plasma membrane and/or cytoplasm locations of MRP. There was apparent difference between normal lung tissues and NSCLC in MRP. The survival analysis of 62 NSCLC showed that the mean survival time of the patients with negative MRP expression was 69.8117.41 months and that of patients with positive MRP expression, 25.384.46 months. Log-rank test suggested that the difference between them was significant (P=0.0156). It was also found that in squamous cell lung cancer the statistically significant difference between the mean survival time of patients with positive MRP expression and those with negative MRP expression (P=0.0153). Multivariate Cox model analysis suggested that the survival time was significantly related to expression of MRP (P=0.035) and lymphatic metastasis (P=0.038). Conclusion: MRP expression in NSCLC is significantly higher compared with normal lung tissues. The mean survival time of patients with negative MRP was relative longer and expression of MRP was an independent factor for prognosis.

110例肺癌疗前MRP检测的临床意义

目的：检测１１０ 例疗前肺癌标本多药耐药相关蛋白（ ＭＲＰ） 的表达与预后的关系。方法：采用免疫组化法。结果：ＭＲＰ 总检出率６３ ．６ ％ （７０／１１０） ，ＳＣＬＣ、ＮＳＣＬＣ 分别为４６ ．７ ％ （７／８） 和６５ ．３ ％ （６２／９５） 。尽管鳞癌ＭＲＰ 的表达（７２ ．４ ％ ） 略高于腺癌（５８ ．３ ％ ） ， 但ＭＲＰ 的表达与病理类型、ＴＮＭ 分期及鳞癌、腺癌的分化程度无关。９０ 例接受化疗，７３ 例ＮＳＣＬＣ 中ＭＲＰ（ － ） 者及ＭＲＰ（ ＋ ～＋ ＋ ） 者中位生存期分别为１８ ．９ 个月和１２ ．６ 个月，Ｌｏｇ － Ｒａｎｋ ｔｅｓｔ 及Ｋａｐｌａｎ － Ｍｅｉｅｒ 生存曲线均示ＭＲＰ（ － ） 者较ＭＲＰ（ ＋ ～＋ ＋ ） 者有生存期优势（ Ｐ＜ ０ ．０２） ；３４ 例鳞癌中，ＭＲＰ（ － ）者生存率明显高于ＭＲＰ（ ＋ ～＋ ＋ ） 者。但ＭＲＰ 表达与腺癌预后无关。结论：ＭＲＰ 可能为鳞癌的负性预后因子。

人乳腺癌MRP基因表达与临床病理参数的关系

目的 研究多药耐受相关蛋白基因 (MRP)在人乳腺癌中的表达与临床病理参数的关系。方法 采用免疫组化技术检测 6 2例初发乳腺癌组织标本MRP表达 ,13例癌旁正常乳腺组织和 8例乳腺良性肿瘤组织作为对照。结果 三种组织阳性率分别为 :乳腺癌 72 6 % ,癌旁正常乳腺组织2 3 1% ,乳腺良性肿瘤 18 2 %。癌组织与其它两种组织相比 ,差异具有显著性 (P <0 0 5 )。乳腺癌组织MRP表达水平与提示乳腺癌疾病发展和预后的临床病理参数 ,如年龄、原发灶大小、淋巴结转移数、病理学类型和组织学分级无关 (P>0 0 5 )。结论 多药耐受表型是与乳腺癌恶性表型同时发生的一种内在本质特征 ,其表达程度不受疾病发展的影响。S P免疫组织化学方法检测临床乳腺标本具有灵敏度高、相对定量。

MRP基因与肿瘤的多药耐药性

在人肿瘤非典型性多药耐药机制的研究中发现了一个新的基因———多药耐药相关蛋白基因(MRP) .该基因位于人 1 6号染色体P1 3∶3,编码 1 531个氨基酸 .其产物为多药耐药相关蛋白(MRP) ,分子质量 1 90ku ,故又名 p1 90 .MRP属ABC超家族成员 ,主要分布在细胞的质膜上 .MRP的功能可能是在能量依赖的外排系统中发挥作用 .除了一些肿瘤细胞系外 ,MRP基因的高表达还见于一些血液系肿瘤及乳腺癌等 .MRP基因的高表达还可能与某些肿瘤的复发和预后有关 .

猪链球菌2型人源分离株MRP单克隆抗体的制备与鉴定

为建立一种针对猪链球菌2型（SS2）毒力因子的特异性检测方法，研制了抗SS2溶菌酶释放蛋白（MRP）单克隆抗体（McAb），并对其生物学活性进行了分析。将表达、纯化的SS2菌株MRP免疫BALB／c小鼠，采用淋巴细胞杂交瘤技术将免疫鼠脾细胞与SP2／0骨髓瘤细胞融合，以纯化的MRP蛋白作为包被抗原，通过间接ELISA方法筛选获得了6株能稳定分泌抗MRPMcAb的杂交瘤细胞系288、3G5、1G1、3G9、186和2C3。经用间接ELISA方法测定，单抗腹水的抗体效价均超过1：10^5，杂交瘤细胞培养上清液的效价为1：128～1：1024。Western-blotting鉴定结果表明，6株单抗均具有特异的生物学活性；以288单抗腹水和SS2多克隆抗血清建立的夹心ELISA方法可特异地检测MRP。

GST-π、ERCC1、MRP和LRP在卵巢癌组织中的表达及意义

目的探讨谷胱甘肽S-转移酶π(GST-π)、切除修复交叉互补基因(ERCC1)、多药耐药相关蛋白(MRP)及肺耐药相关蛋白(LRP)在上皮性卵巢癌组织中的表达及临床意义。方法采用免疫组织化学技术检测67例卵巢恶性肿瘤、20例卵巢良性肿瘤和16例正常卵巢组织中GST-π、ERCC1、MRP及LRP的表达状况,并对相关的临床病理因素进行分析。结果①67例卵巢癌中,GST-π、MRP和LRP阳性表达均显著高于其在卵巢良性肿瘤和正常卵巢组织中的阳性表达(P<0.05),而ERCC1的阳性表达同卵巢良性肿瘤和正常卵巢组织比较差异无统计学意义(P>0.05)。②GST-π的表达与肿瘤分化程度有关,分化越低表达越高(P<0.05);而ERCC1、MRP和LRP的阳性表达与多种临床病理因素无关(P>0.05)。结论 GST-π、ERCC1、MRP及LRP蛋白在卵巢癌的发生发展及耐药机制中发挥重要作用,联合检测对卵巢癌治疗方案的合理制定及化疗反应性的评估具有积极的临床指导意义。

MRP、GST-π、TopoⅡα和LRP在胃癌组织中的表达及意义

背景与目的:多药耐药相关蛋白(multidrugresistance-associatedprotein,MRP)、肺耐药蛋白(lungresistanceprotein,LRP)、谷胱甘肽转移酶(glutathione-S-transferase-π,GST-π)和拓扑异构酶Ⅱα(topoisomeraseⅡα,TopoⅡα)均在多药耐药中发挥重要作用。联合检测它们在胃癌组织中的表达,目前国内外报道极少。本研究旨在探讨联合检测MRP、GST-π、TopoⅡα、LRP在胃癌组织中的表达及意义。方法:应用免疫组化SP法检测MRP、GST-π、TopoⅡα、LRP在90例胃癌标本中的表达,采用χ2检验和Fisher精确检验分析它们表达的意义。结果:(1)MRP、GST-π、TopoⅡα、LRP在胃癌组织中的阳性表达率分别为88.9%、91.1%、74.4%和87.7%,均高于在正常胃粘膜组织中的表达(P<0.05)。(2)MRP、GST-π、LRP在高、中分化腺癌中的表达均高于低分化腺癌,而TopoⅡα在高、中分化腺癌中的表达低于低分化腺癌(P<0.05);此四者的表达情况在不同浸润程度及有/无淋巴结转移的胃癌组织之间均无统计学差异(P>0.05)。(3)MRP、GST-π、TopoⅡα、LRP两两间均无相关性。结论:MRP、GST-π、TopoⅡα和LRP均在胃癌原发性多药耐药中起重要作用,它们在胃癌组织中的表达与肿瘤分化程度有关,而与肿瘤浸润程度及是否有淋巴结转移无关。

鼻咽癌组织中P-gp、MRP和LRP的表达及其临床意义

目的探讨多药耐药基因蛋白(P-gp)、多药耐药相关蛋白(MRP)和肺耐药相关蛋白(LRP)在鼻咽癌组织中的表达情况及其临床意义。方法应用单克隆抗体多药耐药相关蛋白(P-gp),多药耐药基因蛋白(MRP),肺耐药相关蛋白(LRP),对54例鼻咽癌初诊患者的肿瘤组织进行免疫组化检测。结果3项多药耐药指标在54例患者中有不同程度表达。P-gp、MRP、LRP的表达与鼻咽癌病理类型、临床分期及有无淋巴结转移不相关;P-gp表达与MRP、LRP表达不相关,MRP与LRP表达间呈正相关。结论联合检测LP-gp、MRP、LRP在鼻咽癌组织中的表达,对鼻咽癌化疗药物的选择及预后的判断都有重要的参考价值。

应用组织芯片技术检测KAI1、MRP-1、FAK蛋白在肺癌组织中的表达

背景与目的:肿瘤的发生发展、浸润转移与多基因改变密切相关。目前Kang-ai-1(KAI1)、移动相关蛋白(motility-relatedprotein-1,MRP-1)和局部粘着斑激酶(focaladhesionkinase,FAK)3种基因在肺癌中的共同作用研究较少。本研究旨在探讨这3种基因的蛋白产物在肺癌发生发展中的作用及其在肿瘤诊断和预后判断中的价值。方法:应用免疫组化SP方法检测包含240个点的肺癌组织芯片中KAI1、MRP-1和FAK蛋白的表达。结果:KAI1在肺癌原发灶中阳性率为25.9%,MRP-1为42.6%,与正常肺组织(100%)相比均显著下调;FAK蛋白在肺癌组织中阳性率为44.4%,与正常肺组织相比显著增高;KAI1、FAK两种蛋白在肺癌组织中的表达与患者的年龄、性别、肿瘤的大体类型及组织类型无关,而与肿瘤的分化程度、临床分期及是否伴有淋巴结转移密切相关,两种蛋白的表达呈显著负相关。MRP-1蛋白在肺癌组织中的表达与组织类型有关,小细胞肺癌与非小细胞肺癌相比差异显著,MRP-1与KAI1呈显著正相关,与FAK呈显著负相关。结论:KAI1、MRP-1和FAK的异常表达与肺癌的浸润转移有关,联合检测这3项指标对肺癌的发生发展有重要的预测作用。

MRP-1/CD9与高转移人乳腺癌MDA-MB-231细胞恶性行为相关性的体外研究

目的:观察MRP-1/CD9对高转移人乳腺癌细胞系MDA-MB-231体外增殖和侵袭的抑制效应,并初步探讨其作用机制。方法:应用MRP-1/CD9特异性扩增引物,借助RT-PCR获得MRP-1/CD9全长cDNA片段,正向插入pcDNA3.1表达载体中,并将重组质粒导入MDA-MB-231细胞中,G418稳定筛选;应用CFSE-流式细胞仪检测,单层伤口愈合实验,软琼脂克隆形成实验等方法观察了MDA-MB-231细胞转染前后,细胞体外增殖及侵袭能力等指标的变化。Western blot检测AKT、p-AKT和SRC在转染前后的细胞中的表达变化。结果:成功构建全长MRP-1/CD9真核表达载体,将其转染入MDA-MB-231细胞后获得稳定表达MRP-1/CD9的MDA-MB-231克隆株(MDA-MB-231/CD9)。与空质粒转染后的MDA-MB-231细胞相比,MDA-MB-231/CD9细胞运动能力明显减弱,侵袭能力降低;p-AKT和SRC在MDA-MB-231/CD9细胞中表达明显降低。结论:MRP-1/CD9对细胞的运动和侵袭有抑制作用,这种作用与p-AKT和SRC的下调引起E-cadherin介导的粘附增强有关。

MRP与肺癌分化程度、临床分期、淋巴结转移关系的Meta分析

目的从循证医学角度综合分析MRP(多药耐药相关蛋白)与肺癌分化程度、临床分期、淋巴结转移的相关性,预测肺癌化疗的预后。方法采用Meta分析对有关MRP与人肺癌分化程度、TNM分期、淋巴结转移的文献进行综合分析。结果共纳入16个研究,MRP在低分化肺癌组织中的阳性表达率是高分化组织的1.62倍[OR=1.62,95%CI(1.29,2.04)];在Ⅲ-Ⅳ期肺癌组织中的阳性表达率是Ⅰ-Ⅱ期的1.54倍[OR=1.54,95%CI(1.23,1.93)];而与有无淋巴结转移无相关性[OR=0.84,95%CI(0.55,1.27)]。结论 MRP的表达与肺癌组织的分化程度及临床分期存在一定的相关性,而与有无淋巴结转移无关,提示MRP可能成为一项判断肺癌预后的指标。

Ⅲ_A期非小细胞肺癌新辅助化疗后MRP、p53蛋白的表达与预后的关系

目的探讨ⅢA期非小细胞肺癌患者新辅助化疗疗效的病理组织学评价及MRP、p53蛋白表达水平与预后的相关性。方法分析我院73例ⅢA期非小细胞肺癌患者新辅助化疗后病理资料,检测其MRP、p53蛋白表达水平,并随访获得预后资料。结果病理组织学疗效评价有效率为54.79%。化疗疗效、MRP、p53蛋白表达水平与患者预后显著性相关。结论病理组织学评价与临床评价相结合,可以使新辅助化疗的疗效评价更为准确。MRP、p53蛋白的表达水平与新辅助化疗患者的预后相关,可以用来预测化疗疗效,指导临床化疗。

人原发性肝癌中多药耐药相关蛋白MRP的表达、耐药机制及逆转的研究进展

原发性肝癌(primary of liver)是我国常见的恶性肿瘤之一.手术切除率相对较低,术后复发率较高,许多肿瘤常规化疗效果差,预后不良,而肿瘤多药耐药性(MDR)则是肿瘤化疗失败的关键因素.多药耐药相关蛋白(multidrug associated protein,MRP)是一种介导多药耐药性的跨膜转运蛋白,能减少细胞内药物聚积,或改变药物在细胞内分布,从而影响化疗疗效及患者生存.主要针对MRP的结构和功能、在正常组织和肝癌细胞中的表达,以及多药耐药相关蛋白MRP的耐药机制和耐药性逆转等因素进行综述,以为临床提高肝癌的综合治疗水平提供理论基础.

谷子MRP蛋白家族序列特征、分子进化及表达模式分析

本研究旨在深入了解谷子叶酸转运家族成员的基因结构和表达模式,为谷子体内叶酸转运分子机制的研究奠定基础。使用Phytozome、Clustal X、MEGA7.0等在线工具和软件,对谷子MRP家族成员进行生物信息学分析;基于谷子谷穗有参转录组测序数据,分析谷子MRP家族成员表达模式。结果显示,谷子MRP蛋白家族成员共21个,在7号染色体分布最多,有8个基因;17个谷子MRP蛋白偏碱性和4个偏酸性,根据疏水值判断其均为亲水性蛋白;成员SiMRP7、SiMRP12基因的表达量与谷子组织中的总叶酸含量表现出协同降低的趋势,推测这两个蛋白可能对谷子叶酸的积累起到调控作用。本研究有助于进一步鉴定叶酸转运相关蛋白,为后续研究叶酸代谢途径及谷子基因挖掘提供了理论基础。

低频重复经颅磁刺激对氯化锂-匹鲁卡品慢性癫痫大鼠海马CA3区PGP、MRP1、MVP表达的影响

目的研究低频重复经颅磁刺激(rTMS)对氯化锂-匹鲁卡品慢性癫痫大鼠海马CA3区P-糖蛋白(PGP)、多药耐药相关蛋白(MRP)1及主穹隆蛋白(MVP)表达水平的影响。方法 60只大鼠随机分为对照组,模型组,假刺激组,治疗组,每组15只。采用氯化锂-匹鲁卡品腹腔注射构建癫痫大鼠模型,治疗组采用rT MS治疗,比较各组治疗过程中癫痫发作次数及CA3区PGP、MRP1及MVP的表达水平。结果治疗组癫痫发作频率低于模型组及假刺激组(P<0.05)。治疗组PGP、MRP1及MVP表达水平显著低于模型组及假刺激组(P<0.05),较对照组显著升高(P<0.05)。结论低频rTMS可抑制模型大鼠海马CA3区PGP、MRP1及MVP过度表达,低频rTMS的抗痫作用可能与之有关。

Multidrug resistance associated proteins in multidrug resistance

Multidrug resistance proteins(MRPs) are members of the C family of a group of proteins named ATP-binding cassette(ABC) transporters.These ABC transporters together form the largest branch of proteins within the human body.The MRP family comprises of 13 members,of which MRP1 to MRP9 are the major transporters indicated to cause multidrug resistance in tumor cells by extruding anticancer drugs out of the cell.They are mainly lipophilic anionic transporters and are reported to transport free or conjugates of glutathione(GSH),glucuronate,or sulphate.In addition,MRP1 to MRP3 can transport neutral organic drugs in free form in the presence of free GSH.Collectively,MRPs can transport drugs that differ structurally and mechanistically,including natural anticancer drugs,nucleoside analogs,antimetabolites,and tyrosine kinase inhibitors.Many of these MRPs transport physiologically important anions such as leukotriene C4,bilirubin glucuronide,and cyclic nucleotides.This review focuses mainly on the physiological functions,cellular resistance characteristics,and probable in vivo role of MRP1 to MRP9.

EFFECTS OF NEOADJUVANT CHEMOTHERAPY ON MDR1 AND MRP GENE EXPRESSION IN PRIMARY BREAST CANCER

Objective: To investigate the effects of neoadjuvant chemotherapy on the expression of drug resistance genes, multidrug resistance-1 (MDR1) and multidrug resistance-associated protein (MRP), in patients with primary breast cancer. Methods: MDR1 and MRP expression were detected by semi-quantitative RT-PCR in 20 patients with primary breast cancer, before and after chemotherapy. Results: Before chemotherapy, MDR1 and MRP expression can be detected in 15 cases (75%) and 18 cases (90%) respectively. After chemotherapy, expression of MDR1 is not significantly different from that before chemotherapy, but expression of MRP is significantly different from that before chemotherapy. Conclusion: Expression of drug resistance gene MRP, but not MDR1, is enhanced in patients with primary breast cancer submitted to neoadjuvant chemotherapy.

Construction of Multi-ribozyme Expression System and Its Characterization of Cleavage on the MDR1/MRP1 Double Target Substrate in vitro

To improve catalytic activity of ribozyme on its substrate, the multi-ribozyme expression system was designed and constructed from 20 cis-acting hammerhead ribozymes undergoing self-cleavage with 10 trans-acting hammerhead ribozymes inserted alternatively regularly and the plasmid of pGEM-MDR1/MRP1 used to transcribe the MDR1/MRPl（196/210） substrate containing double target sites was also constructed by DNA recombination. Endonuclease digestion analysis and DNA sequencing indicate all the recombinant plasmids were correct. The clea- vage activities were evaluated for the multi-ribozyme expression system on the MDR1/MRP1 substrate in the cell free system. The results demonstrate that the cis-acting hammerhead ribozymes in the multi-ribozyme expression system were able to cleave themselves and the 72 nt of 196Rz and the 71 nt of 210Rz trans-acting hammerhead ribozymes were liberated effectively, and the trans-acting hammerhead ribozymes released were able to act on the MDR1/MRP1 double target RNA substrate and cleave the target RNA at specific sites effectively. The multi- ribozyme expression system of the [Coat＇A196Rz/Coat＇B210Rz]5 is more significantly superior to that of the [Coat＇A 196Rz/Coat＇B210Rz] 1 in cleavage of RNA substrate. The fractions cleaved by [Coat＇A 196Rz/Coat＇B210Rz]5 on the MDR1/MRP1 substrate for 8 h at observed temperatures showed no marked difference. The studies of Mg^2＋ on cleavage efficiency indicate that cleavage reaction is dependent on Mg^2＋ ions concentration. The plot of lg（kobs） vs. lgc（Mg^2＋） displays a linear relationship between 2.5 mmol/L and 20 mmol/L Mg^2＋. It suggests that Mg^2＋ ions play a crucial role in multi-ribozyme cleavage on the substrate.