不同剂量亚砷酸钠染毒大鼠多药耐药相关蛋白2表达水平的变化

目的 观察不同剂量亚砷酸钠染毒大鼠肝细胞膜转运蛋白-多药耐药相关蛋白2（multidrug resistance associated protein2，MRP2）表达水平的变化及与砷代谢的关系。     

多药耐药相关蛋白及其在肿瘤耐药中的作用

多药耐药(multidrug resistance,MDR)是导致肿瘤患者化疗失败的主要原因。介导多药耐药的重要机制之一是多药耐药相关蛋白(multidrug resistance-associated proteins,MRPs)的表达增加。MRPs是一类ATP能量依赖型跨膜转运蛋白,是具有选择性和特异性的药物外排泵。本文主要针对MRPs的生理特征、结构特点、耐药谱特征及其逆转进行综述。     

基于多药耐药相关蛋白2(Abcc2/Mrp2)在大鼠肾脏表达性别差异的氧氟沙星药动学变化(英文)

本研究旨在探讨基于多药耐药相关蛋白2(Abcc2/Mrp2)在大鼠肾脏表达性别差异的氧氟沙星的药代动力学变化。采用高效液相色谱法(HPLC)分别测定经尾静脉注射给予氧氟沙星(30 mg.kg1)后大鼠血浆和尿液中氧氟沙星的浓度;通过免疫组化法和流式细胞术分别对雄性和雌性大鼠肾脏Mrp2的表达进行定性和定量分析。结果表明在雄性大鼠体内,氧氟沙星药时曲线下面积(AUC)明显小于雌性大鼠,而尿排总量明显大于雌性大鼠;Mrp2在雄性大鼠肾脏中的表达显著高于雌性大鼠。因此,氧氟沙星药动学性别差异可能是由Mrp2在雄性和雌性大鼠肾脏中的表达差异所引起的。     

何首乌肝损伤模型大鼠胆汁淤积现象及相关蛋白表达研究

目的 观察经脂多糖（LPS）诱导后连续给予何首乌醇提液（AEP）7 d大鼠的肝损伤程度及胆汁淤积相关指标的变化。方法 将雄性SD大鼠随机分为5组：对照组、LPS组、LPS+对乙酰氨基酚（APAP）组、AEP组、LPS+AEP组,LPS、LPS+APAP、LPS+AEP组按大鼠体质量分别尾iv给予4 mg/kg LPS,对照组与AEP组给予等体积生理盐水;2 h后LPS+APAP组ig给予625 mg/kg APAP,AEP组与LPS+AEP组ig给予12 g/kg,每天1次,连续给药7 d,建立特异质肝损伤炎症模型。观察体质量变化,并分别于造模后2 h、14 h、5 d、8 d检测血清生化中肝功能相关指标的变化,同时收集胆汁,计算胆汁流速与密度,并检测胆汁中主要成分变化。进行肝脏系数及组织病理学检查,并对胆汁淤积相关蛋白胆盐输出泵转运蛋白（BSEP）、多药耐药蛋白2（MRP2）及多药耐药蛋白3（MRP3）进行Real-Time PCR检测。结果 经过LPS诱导2 d后,LPS+AEP组与对照组、AEP组比较体质量明显下降,5、8 d肝脏系数显著增加（P＜0.05）;血清生化指标分析结果显示,与对照组比较,LPS+AEP组丙氨酸氨基转移酶（ALT）、天门冬氨酸氨基转移酶（AST）水平无明显变化;造模后8 d的总胆红素（TBIL）明显降低（P＜0.05）,ALP明显升高（P＜0.05）;可观察到胆汁密度和胆汁流速明显降低（P＜0.05）,对胆汁成分分析显示,与对照组比较,LPS+AEP组总胆固醇（TCHO）显著升高、TBIL显著降低（P＜0.05）;病理结果显示,AEP组出现轻微肝细胞变性,而LPS+AEP组可见严重局灶坏死;转录水平结果发现,LPS诱导后可使得BSEP、MRP2在14 h时出现短期抑制（P＜0.05）,单独给予AEP可使BSEP、MRP2和MRP3的表达水平短时显著升高（P＜0.05、0.01）,而LPS+AEP给药第8 d对大鼠肝脏BSEP、MRP2无显著性影响,可使MRP3转录水平升高（P＜0.05）。结论 经LPS诱导的AEP可明显损伤大鼠肝细胞并干扰胆汁分泌功能,引起胆汁成分相关生化指标的改变,对BSEP与MRP2水平无显著影响,MRP3出现代偿性升高,提示确实存在胆汁淤积症状,但可能是存在其他机制。     

多药耐药相关蛋白1及其与肿瘤关系的研究进展

多药耐药（MDR）是导致临床肿瘤化疗失败的重要原因。多药耐药相关蛋白1（MRP1/ABCC1）被认为是介导肿瘤多药耐药的主要跨膜转运蛋白之一。 探究MRP1/ABCC1的结构、功能,以及与肿瘤的关系,有利于指导临床合理用药和肿瘤预后的评估。     

贲门癌组织中多药耐药基因和多药耐药相关蛋白基因表达的临床研究

目的 了解多药耐药基因(MDR1)和多药耐药相关蛋白基因(MRP)在贲门癌组织中的表达及其临床意义。方法 采用逆转录-多聚酶链反应(RT-PCR)。观察46侧贲门癌及癌旁组织中MDR1和MRP的表达。结果 癌组织中MDR1和MRP表达的阳性率分别为63%和50%,均高于癌旁组织(P<0.05);贲门癌术前化疗者MDR1 mRNA和MRP mRNA表达水平显著高于未化疗者(P<0.05);中低分化肿瘤MDR1和MRP两基因mRNA表达水平高于高分化肿瘤(P<0.05)。结论 贲门癌组织中具有内源和获得性耐药性;MDR1和MRP表达与肿瘤的TNM分期无关,其高表达状态可预示肿瘤组织的分化不良。     

补骨脂素对人乳腺癌多药耐药 Bcl-2基因蛋白表达的影响

多药耐药性（MDR）是肿瘤化疗失败的主要原因之一。补骨脂是补益药中少有的钙离子通道拮抗剂，补骨脂素是其主要成分之一，以往我们对其逆转MDR进行了几方面研究，明确其有明显的逆转耐药作用。目前已有报道探讨Bcl-2家族与白血病MDR形成的关系。本实验就补骨脂素对MCF-7多药耐药细胞株Bcl-2基因蛋白表达影响报道如下。     

多药耐药相关蛋白基因表达与食管及贲门癌的关系

目的 探讨食管癌及贲门癌组织中多药耐药相关蛋白(MRP)基因的表达与其病理特征的关系。方法 应用逆转录酶-多聚酶链反应(RT-PCR)方法,检测了83例食管癌和贲门癌组织及28例患者45枚淋巴结中MRP基因的表达,并与相应癌旁组织进行对照分析。结果 35例食管癌和48例贲门癌组织中MRP阳性率(31.4％和16.7％)与其对应癌旁组织阳性率(5.7％和2％)比较具有显著性差异(P<0.01)。26枚转移淋巴结中,MRP阳性6例(23.1％);19枚非转移淋巴结组织未见MRP。在食管癌和贲门癌侵犯深肌层或纤维层及TNM Ⅲ,Ⅳ期的MRP阳性率(26.6％和28.8％)高于肿瘤侵犯浅肌层以下和TNM Ⅰ,Ⅱ期(10.5％和12.9％),均分布于低分化肿瘤中。对48例术后1～2年的患者随访发现,MRP阳性的肿瘤复发、转移的发生率高于MRP阴性者(P<0.05)。结论 食管、贲门癌组织中MRP基因表达增高,与转移淋巴结组织的MRP基因表达具有一致性,MRP的阳性表达除表现肿瘤的多药耐药外,还提示肿瘤预后不良。     

海人酸致痫大鼠中多药耐药相关蛋白1和主穹窿蛋白的表达及作用

目的:探讨多药耐药相关蛋白1(MRP1)和主穹窿蛋白(MVP)在难治性癫痫中的耐药机制.方法:用免疫组化法检测海人酸(KA)致痫大鼠海马组织中MRP1和MVP的表达,应用SPSS17.0软件进行统计分析.结果:KA组的MRP1和MVP的表达均比对照组明显增高(P<0.01).KA组的MRP1和MVP的表达相似,随时间段...     

三氧化二砷对人肺腺癌A549/R细胞多药耐药相关蛋白表达的影响

目的探讨三氧化二砷(As2O3)对人肺腺癌A549/R细胞耐药性的逆转作用及对多药耐药相关蛋白（MRP）表达的影响。方法以荧光分光光度计测定细胞内药物浓度的改变，采用半定量逆转录聚合酶联反应(RT PCR) 技术检测As2O3处理后A549/R MRP基因表达的变化。结果As2O3的非细胞毒性剂量可增加A549/R细胞内多柔比星(ADM)浓度，降低其IC50。A549/R细胞中MRP呈过表达状态，不同浓度的As2O3处理A549/R后MRP表达水平明显降低。结论As2O3可部分逆转A549/R细胞对ADM的耐药性，其逆转机制与改变MRP基因表达有关。     

Expression and immunolocalization of multidrug resistance protein 2 in rabbit small intestine

Multidrug resistance protein 2 (MRP2) is an ATP-dependent transporter of anionic drugs and conjugates. It functions as an efflux pump in the apical membranes of liver and kidney cells, but its membrane localization in small intestine has not yet been defined. The present study demonstrates exclusive localization of Mrp2 to the brush-border (apical) membrane of villi, decreasing in intensity from the villus tip to the crypts. In immunoblot analysis of crude membranes of various rabbit tissues, Mrp2 was only found in small intestine, kidney and liver. These results are in-line with the supposed function of Mrp2 in drug excretion.     

黄酮类化合物对肿瘤多药耐药调节作用的研究进展

多药耐药是临床上化疗失败的重要原因之一。黄酮类化合物存在于多种植物中,具有广泛的药理活性,对P-糖蛋白(P-gp)、多药耐药相关蛋白(MRP)、乳腺癌耐药蛋白(BCRP)等外向转运蛋白的抑制作用使其可能成为肿瘤多药耐药调节剂。文中分别对黄酮类化合物对ABC家族转运蛋白抑制作用的研究概况、作用机制以及构效关系进行综述,为肿瘤多药耐药抑制剂的开发和应用提供重要信息。     

人脑胶质瘤中耐药蛋白P-gp和MRP1的表达

目的 探讨人脑胶质瘤中耐药蛋白P—gp和MRP表达情况。方法 37例人脑胶质瘤标本，包括星形细胞瘤25例(纤维型7例，原浆型6例，间变型12例)，胶质母细胞瘤12例(多形性胶质母细胞瘤4例)；10例正常脑组织作为对照。P—gp和MRPl的检测采用免疫组化ABC法。结果 P—gp肿瘤中阳性率为24．3％(9／37)，正常脑组织为10％(1／10)，两无统计学差异。P-gp在肿瘤中阳性率为73％(27／37)，正常脑组织无表达，两组间有明显差异。P—gp和MRPl在标本血管内皮细胞中存在表达，其中P—gp阳性率为24．3％(9／37)，MRPl为35．1％(13／37)。结论 人脑胶质\瘤中，P—gp和MRPl均有所表达，其中P—gp较少，而MRPl明显增多，提示与耐药关系密切。在肿瘤血管内皮细胞中，两存在异常，提示血脑屏障可能参与了肿瘤耐药现象的产生。     

黄芩素对胆汁外排转运体MRP2和BSEP的影响

<正>多药耐药相关蛋白2(MRP2/ABCC2)属于ABC转运蛋白超家族,肝脏细胞所表达的MRP2,能介导一些有机阴离子的转运,例如葡萄糖醛酸盐结合物等物质的转运[1]。胆汁酸盐输出泵转运蛋白(BSEP)是肝脏中参与胆汁外排转运的另一重要的转运体,主要介导单价胆汁酸、硫酸盐胆酸等转运过程。在肝细胞中MRP2和BSEP相互协调,可以介导胆汁的排泄,这两种转运体的表达均可以在转录和转录后两个     

Multidrug resistance correlates with overexpression of Muc4 but inversely with P-glycoprotein and multidrug resistance related protein in transfected human melanoma cells

Due to the size, glycosylation, and location in the plasma membrane of the sialomucin complex Muc4, which has been implicated in ErbB2 signaling, in the repression of apoptosis and cell adhesion, and in tumor metastasis, studies were initiated to determine whether its presence could influence cell sensitivity to anticancer drugs. Growth inhibition assays using melanoma cell lines that either express the glycoprotein (Muc4(+)) or do not (Muc4(-)) showed that Muc4 renders cells resistant to taxol, doxorubicin, vinblastine, rhodamine 123, and 2-deoxyglucose. When treated with various concentrations of doxorubicin, Muc4(+) cells were blocked less frequently in G(2) and underwent less DNA fragmentation (apoptosis and/or necrosis) than Muc4(-) cells. All of the drugs tested (except for 2-deoxyglucose) are well recognized by P-glycoprotein-mediated multidrug resistance 1 (MDR1) and to a lesser degree by multidrug resistance related protein 1 (MRP1) transporters. Therefore, transporter gene expression in these cells was assayed. Surprisingly, Muc4(+) cells expressed lower levels of both transporter genes than Muc4(-) cells. Moreover, rhodamine 123 was retained more highly in the Muc4(+) than in the Muc4(-) cells, demonstrating that these transporters are functional. Overall, these results indicate that although Muc4(+) cells express less MDR1 and MRP1, they are more resistant to drugs recognized by these transporters.     

利福平对小鼠肝细胞胆汁酸转运体Bsep和Mrp2表达与定位的影响

目的利福平(Rifampicin,RIF)具有肝毒性,但其机制尚不清楚。本研究在RIF诱导的肝内胆汁淤积小鼠中,探讨RIF对肝细胞胆汁酸转运体胆汁酸输出泵(bile salt exportpump,Bsep)和多药抵抗相关蛋白-2(multidrug resistance-associated protein-2,Mrp2)表达和定位影响。方法 48只♀ICR小鼠随机分为4组,RIF1wk组:经灌胃给予RIF(200mg.kg-1.d-1),连续1周,于末次给药后6h取材;RIF6h组:单次灌胃给予RIF(200mg.kg-1)后6h取材;RIF1周对照组(CON1wk)与RIF6h对照组(CON6h):经灌胃给予等容积生理盐水。所有小鼠均收集血液和肝组织,常规生化检测血清丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转移酶(AST)、碱性磷酸酶(ALP)、总胆红素(TB)和结合胆红素(DB),并检测小鼠血清和肝组织总胆汁酸(TBA)水平。HE染色分析肝组织病理改变。RT-PCR测定肝脏肝细胞胆汁酸转运体Bsep和Mrp2mRNA表达。免疫荧光法分析Bsep和Mrp2在肝细胞的位置。结果给予RIF1周后,小鼠血清TB由(1.25±0.69)μmol.L-1上升至(65.73±12.08)μmol.L-1,上升近70倍,DB由(0.77±0.40)μmol.L-1上升至(53.33±12.43)μmol.L-1,上升约80倍,ALP由(110.2±13.8)U.L-1上升至(279.5±80.4)U.L-1,上升约1.5倍,TBA由(3.15±0.89)μmol.L-1上升至(13.54±6.51)μmol.L-1,上升约5倍并伴有血清ALT和AST轻度升高;肝脏组织TBA由(0.15±0.04)μmol.g-1liver上升至(0.30±0.19)μmol.g-1liver,上升约2倍;肝脏组织HE染色显示肝细胞出现脂肪变性、轻度坏死和炎症。单次给予RIF6h后血清TB、DB、ALP、ALT、AST和TBA明显上升,但未观察到小鼠肝脏组织病理发生改变。免疫荧光分析显示,给予小鼠RIF1wk与单次给予RIF6h后肝细胞中Bsep和Mrp2的定位发生了改变。而无论单次给予RIF还是连续给药1周,肝细胞Bsep和Mrp2mRNA表达水平均未发生变化。结论肝细胞胆汁酸转运体Bsep和Mrp2定位改变可能是RIF诱发肝内胆汁淤积的重要机制。     

Inhibition of hyaluronan export from human fibroblasts by inhibitors of multidrug resistance transporters

In a previous report we described the export of hyaluronan from Streptococcus pyogenes by an ABC transporter. Extending these findings a sequence homology search against human proteins revealed a strong homology to the multidrug resistance transporter ABC-B (MDR-1) and ABC-C (MRP 5). Using several inhibitors directed against these and other transporters, a decreased hyaluronan production in cell culture as well as in hyaluronan synthase activity in purified membrane fractions was observed. The inhibitory capacity (IC(50) concentrations) was compared the with reported IC(50)- or the K(i)-concentrations for individual transporters. These analyses revealed that hyaluronan is synthesized within the cytoplasm of mammalian cells and actively secreted into the pericellular space by energy dependent transport proteins. While inhibition of several transport proteins resulted in a decrease of hyaluronan export, inhibition of the MRP5 transporter was the most effective one to decrease hyaluronan in the cell culture supernatant indicating that hyaluronan export is one physiological role of this transport protein.     

Autophagy involvement in cadmium resistance through induction of multidrug resistance-associated protein and counterbalance of endoplasmic reticulum stress WI38 lung epithelial fibroblast cells

Human multidrug-resistance associated protein (MRP1) is known as a cellular efflux pump of heavy metals and anticancer drugs. In our previous study, MRP was found to have involvement in cell protection against cadmium (Cd) toxicity through apoptosis interruption. The purpose of the present study was to investigate the molecular mechanism of MRP1 in Cd resistance. For this purpose, we developed Cd-resistant cells (RWI38) from WI38 human lung epithelial fibroblast cells, which showed a 4-fold resistance to Cd when compared to WI38 cells. WI38 cells elicited endoplasmic reticulum (ER) stress through RNA-dependent protein kinase-like ER kinase (PERK) and the eukaryotic translation initiation factor 2 alpha (eIF2α), Chop, and glucose-regulated protein (Grp78). RWI38 cells responding to Cd did not elicit ER stress or mitochondrial apoptosis, but induced autophagy, as demonstrated by Atg5 induction, LC3 conversion, and formation of GFP–LC3 dots. A pharmacological inhibitor of p38 downregulated Cd-induced Atg5 and LC3II. A pharmacological inhibitor of autophagy or silencing of atg5 dephosphorylated p38 and Akt, and downregulated MRP1 and procaspase-3. However, pharmacological inhibition or silencing of mrp-1 had no affect on Cd-induced phosphorylated p38 and LC3II. These data indicate that Cd induces autophagy in RWI38 cells through a mechanism that involves p38 activation, which is involved in cell protection through counterbalance of ER stress and MRP1 induction.     

Induction of proteins involved in multidrug resistance (P-glycoprotein, MRP1, MRP2, LRP) and of CYP 3A4 by rifampicin in LLC-PK1 cells

P-glycoprotein, multidrug resistance-related proteins (MRPs) and lung resistance-related protein (LRP) are involved in multidrug resistance in tumor cells but are also expressed in normal tissues. In the LLC-PK(1) tubular renal cell line, a 15-day treatment with 25 microM rifampicin significantly increased the mRNA levels of P-glycoprotein, MRP1, MRP2, LRP and cytochrome P450 3A4 (CYP 3A4). Western blot analysis confirmed a moderate increase in the expression of P-glycoprotein and MRP2, but not MRP1 also at the protein level. The intracellular uptake of doxorubicin was significantly lower in rifampicin pretreated cells. A pretreatment with 6-[82S,4R,6E)-4-methyl-2-(methylamino)-3-oxo-6-octenoic acid]cyclosporin D, valspodar (PSC 833), a specific inhibitor of P-glycoprotein, with (3-(3-(2-(7-chloro-2-quinidinyl)ethenyl-phenyl)((3-diimethyl amino-3oxo propyl)thio)methyl)thio)propanoic acid, sodium salt (MK-571), a specific inhibitor of MRP1, and with verapamil, that inhibits both proteins, significantly increased doxorubicin cell accumulation in rifampicin pretread cells. In rifampicin treated cells cultured on porous membranes, doxorubicin showed a polarized transport, that was reduced by a pretreatment with PSC 833. A chronic treatment with rifampicin induces the expression of transport proteins and of CYP 3A4 and could therefore alter the renal elimination kinetics of drugs that are their substrates.