肾脏有机阳离子转运体家族研究进展

肾脏转运体在肾脏处置药物过程中发挥重要作用.临床所用药物与肾脏有机阳离子转运体家族密切相关.本文对肾脏有机阳离子转运体家族的主要成员及其特征、影响因素以及实验方法等研究进展进行综述.     

有机阴离子转运多肽介导的药物相互作用研究进展

药物转运体介导的药物相互作用正日益受到人们的关注和重视,近年来的研究表明药物转运体对药物的吸收、分布和排出有着重要的作用。有机阴离子转运多肽是一类药物摄取转运体,其表达分布广泛,转运的内源性和外源性的底物众多,一些药物因抑制有机阴离子转运体而导致药物相互作用。本文综述了有机阴离子转运多肽家族不同成员的组织分布、结构特点以及其介导的药物相互作用的最新研究进展。     

疾病状态下有机阴离子转运体表达和功能的变化及其机制研究进展

有机阴离子转运体属于溶质转运体22亚家族成员,是一类重要的摄取类转运体,其有多个亚型。有机阴离子转运体在体内介导多种小分子内源性物质的转运,起到维持机体内环境稳态的作用。此外,临床上许多药物也是有机阴离子转运体的底物。研究表明某些疾病可能导致有机阴离子转运体表达和功能的异常改变,进而影响药物的疗效或导致机体内源性物质水平紊乱。对有机阴离子转运体的分布和功能进行简要介绍,并综述了疾病状态下有机阴离子转运体表达和功能变化及其机制的研究进展。     

有机阴离子转运肽在药物转运中的作用

溶质运载蛋白家族(solute carrier family,SLC)和ATP结合盒转运蛋白家族(ATP binding cas-sette family,ABC)在药物吸收、消除和组织分布中起重要作用。本综述将对有机阴离子转运肽(or-ganic anion transporting polypeptide,OATP)的最新命名、分类、组织分布、功能及在药物转运中的作用加以介绍。     

尿酸转运体与帕金森病研究进展

尿酸是生理性的抗氧化剂,流行病学及临床资料显示低尿酸水平与帕金森病(PD)发病率增高密切相关,PD患者的血尿酸水平显著降低,高血尿酸水平能够降低PD的发病以及减慢PD的进展速度。尿酸转运体在尿酸分泌和重吸收过程中发挥关键作用,从而影响尿酸水平。本文将从尿酸转运体的角度介绍尿酸转运体与PD的研究进展。     

尿酸转运蛋白在尿酸转运中的作用研究进展

人体内尿酸是嘌呤代谢的终产物,具有很强的抗氧化性,在保证细胞正常功能方面起着非常重要的作用,但过多的尿酸可导致痛风、心血管及肾脏功能异常[1]。高尿酸血症是指细胞外液的尿酸盐呈超饱和状态,一般认为血浆尿酸盐浓度超过正常值(男性>7mg·dL-1,女性>6mg·dL-1)时,应考虑高尿酸血症。因此,探讨尿酸在体内的代谢及转运具有重要意义。1997年,Sekine T等[2]发现,在肾脏上皮细胞管腔膜及基底外侧膜上表达有机阴离子转运体(Organic anion transporters,OATs),它属于SLC22A家族(Amphiphilic solute transporterfamily),用于调节内源性及…     

药物转运体有机阴离子转运多肽1B1基因多态性的研究进展

有机阴离子转运多肽1B1(OATP1B1)是肝脏中重要的药物转运通路之一,其遗传多态性可改变药动学参数,影响多种药物在体内的分布,继而影响药效及药物不良反应. 该文对OATP1B1结构与功能,OATP1B1编码基因的结构及多态性对功能的影响,SLCO1B1多态性对他汀类药物的影响,SLCO1B1多态性对口服降糖药的影响,SLCO1B1多态性对抗肿瘤药的影响等进行综述.     

10种肾毒性中药对小鼠肾脏有机阴离子转运体的影响

目的:研究10种肾毒性中药对小鼠肾脏有机阴离子转运体(Oats)中3个主要亚型(Oat1、Oat2、Oat3)的影响。方法:1 840只SPF级NIH小鼠随机分为正常对照(等容纯水)组,丙磺舒(30 mg/kg)组,羧甲基纤维素钠(CMC-Na)组与白头翁、延胡索、草乌、川乌、独活、皂角刺、虎杖、甘遂、侧柏叶、木香水煎剂高、低剂量组,ig给药,bid,连续5 d。末次给药1 h后,尾iv给予对氨基马尿酸(PAH,30 mg/kg),测定小鼠肾脏匀浆中PAH药动学参数与在1、5、10、15、20 min时间点的肾组织中PAH的蓄积量。用DAS 2.0分析软件计算血中PAH的药动学参数。分组与给药同上,末次给药1 h后制作肾切片置于PAH-buffer中,测定肾切片PAH摄取量。结果:与正常对照组比较,延胡索高剂量组,草乌高、低剂量组,独活高剂量组,虎杖高、低剂量组,侧柏叶高剂量组t1/2β升高;10种中药高、低剂量组Vd均降低;除独活低剂量组、皂角刺低剂量组、甘遂低剂量组外,其余用药组的CL均降低、AUC0-20 min均升高,差异均具有统计学意义(P<0.01或P<0.05)。与正常对照组比较,白头翁高剂量组,延胡索高剂量组,草乌高剂量组,川乌高、低剂量组,独活高、低剂量组,皂角刺高、低剂量组,虎杖高、低剂量组,甘遂高、低剂量组,侧柏叶高、低剂量组,木香高、低剂量组小鼠肾组织PAH蓄积量增加,差异有统计学意义(P<0.01或P<0.05)。与正常对照组比较,延胡索高剂量组,草乌高、低剂量组,皂角高、低剂量组,甘遂高剂量组,侧柏叶高、低剂量组,木香高剂量组小鼠肾切片PAH摄取量减少,差异有统计学意义(P<0.01或P<0.05)。结论:10种肾毒性中药可能通过抑制有机阴离子转运体Oat1、Oat2、Oat3而导致肾损伤。     

小檗碱对有机阴离子转运体抑制作用及双向跨膜转运研究

目的 研究小檗碱对有机阴离子转运体（OATs）的抑制作用及其双向跨膜转运情况。方法 应用由转染试剂Lipo 3 000介导的动物细胞转基因方法、经筛选得到人有机阴离子转运体OAT1、OAT2、OAT3、OAT4、OAT7和URAT1高表达单克隆细胞株;以野生型（WT）细胞为对照组,用各转运体放射性同位素标记底物和抑制剂验证其转运活性;观察100 μmol/L小檗碱对各转运体的抑制作用,并测定小檗碱对URAT1转运活性的半数抑制浓度（IC₅₀）。通过Caco-2细胞模型研究小檗碱的双向跨膜转运情况。结果 100 μmol/L小檗碱使OAT1、OAT2、OAT3、OAT4、OAT7和URAT1相对转运活性分别下降至（70.48±4.23）%、（69.13±1.28）%、（72.12±3.28）%、（79.77±6.49）%、（69.51±5.99）%、（38.4±2.67）%;小檗碱对URAT1抑制作用的IC₅₀为13.6 μmol/L;在50和100 μmol/L浓度下,小檗碱在顶侧（AP侧）-基底侧（BL侧）方向的跨膜渗透率P_app（A-B）分别为0.28×10^-6 cm/s和0.40×10^-6 cm/s,其相对应的外排率分别为3.18和3.15。结论 小檗碱对URAT1的抑制作用较强,对OAT1、OAT2、OAT3、OAT4、OAT7抑制作用相对较弱,小檗碱是一些外排蛋白的底物,为预测小檗碱可能发生的药物-药物相互作用、解释生物利用度低提供了理论依据。     

药物转运体OAT2研究进展

有机阴离子转运体2(OAT2)属于有机阴离子转运体家族成员,主要分布于肝肾,介导肌酐、尿酸等内源性物质及多种外源性药物的跨膜转运。OAT2对外源性物质如药物的体内过程如吸收、分布、代谢和排泄过程起着重要作用。研究表明OAT2的表达与活性被药物、疾病、性别及基因多态性等多种因素影响,亦受到核受体等信号通路调控。故本文综述药物转运体OAT2的结构与分布、底物、调控机制、临床意义的研究进展,为OAT2可能介导药物相互作用及药物疗效预测提供参考。     

Role of mouse organic anion transporter 3 (mOat3) as a basolateral prostaglandin E2 transport pathway

Renal organic anion transporters play an important role in the handling of a number of endogenous and exogenous anionic substances in the kidney. In this study, we investigated prostaglandin E(2) (PGE(2)) transport properties and intrarenal localization of mouse organic anion transporter 3 (mOat3). When expressed in Xenopus oocytes, mOat3 mediated the time- and concentration-dependent transport of PGE(2) (K(m): 1.48 microM). PGE(2) transport mediated by mOat3 was trans-stimulated by intracellular glutarate injected into the oocytes. PGE(2) efflux via mOat3 was also trans-stimulated by extracellular glutarate. Thus, mOat3 was shown to mediate the bidirectional transport of PGE(2), partly coupled to the dicarboxylate exchange mechanism. Immunohistochemical study revealed that mOat3 protein was localized at the basolateral membrane of renal proximal and distal tubules. Furthermore, diffuse expression of mOat3, including expression in the basolateral membrane in macula densa (MD) cells, was observed. These results indicate that mOat3 plays an important role as a basolateral transport pathway of PGE(2) in the distal nephron including MD cells that may constitute one of the indispensable steps for renin release and regulation of the tubuloglomerular feedback mechanism.     

Human organic anion transporter hOAT3 is a potent transporter of cephalosporin antibiotics, in comparison with hOAT1

We examined the substrate specificity of human organic anion transporter (hOAT) 1 and hOAT3 for various cephalosporin antibiotics, cephaloridine, cefdinir, cefotiam, ceftibuten, cefaclor, ceftizoxime, cefoselis and cefazolin by using HEK293 cells stably transfected with hOAT1 or hOAT3 cDNA (HEK-hOAT1, HEK-hOAT3). Additionally, we examined the uptake of various compounds by these transfectants. The mRNA level of hOAT3 in HEK-hOAT3 was about three-fold that of hOAT1 in HEK-hOAT1. Functional expression of hOAT1 and hOAT3 was confirmed by the uptake of p-[14C]aminohippurate and [3H]estrone sulfate, respectively. p-[14C]Aminohippurate, [3H]estrone sulfate, [14C]captopril, [3H]methotrexate, [3H]ochratoxin A, [3H]leucovorin and [3H]cimetidine were shown to be substrates for hOAT1 and hOAT3, and [3H]dehydroepiandrosterone sulfate was shown to be a substrate for hOAT3. All cephalosporin anitibiotics tested were shown to inhibit the uptake of p-[14C]aminohippurate and [3H]estrone sulfate via hOAT1 and hOAT3, respectively, in a dose-dependent manner, and the IC50 values of these antibiotics, except for cefaclor, for the hOAT1-mediated uptake of p-[14C]aminohippurate were within four-fold of those for the hOAT3-mediated uptake of [3H]estrone sulfate. The uptake of cephaloridine, cefdinir and cefotiam by HEK-hOAT3 was 35-50-fold greater than that by control cells. Moreover, the accumulation of the other cephalolsporin antibiotics was significantly greater in HEK-hOAT3 than in control cells. In contrast, the uptake of these antibiotics by HEK-hOAT1 was within two-fold of that by control cells. In conclusion, hOAT3 plays a more important role than hOAT1 in the renal secretion of cephalosporin antibiotics.     

The inhibitory effects of five alkaloids on the substrate transport mediated through human organic anion and cation transporters

1.?Human solute carrier transporters (SLCs) are important membrane proteins mediate the cellular transport of many endogenous and exogenous substances. Organic anion/cation transporters (OATs/OCTs) and organic anion transporting polypeptides (OATPs) are essential SLCs involved in drug influx. Drug–drug/herb interactions through competing for specific SLCs often lead to unsatisfied therapeutic outcomes and/or unwanted side effects. In this study, we comprehensively investigated the inhibitory effects of five clinically relevant alkaloids (dendrobine, matrine, oxymatrine, tryptanthrin and chelerythrine) on the substrate transport through several OATs/OCTs and OATPs.

2.?We performed transport functional assay and kinetic analysis on the HEK-293 cells over-expressing each SLC gene.

3.?Our data showed tryptanthrin significantly inhibited the transport activity of OAT3 (IC₅₀?=?0.93?±?0.22?μM, K_i?=?0.43?μM); chelerythrine acted as a potent inhibitor to the substrate transport mediated through OATP1A2 (IC₅₀?=?0.63?±?0.43?μM, K_i?=?0.60?μM), OCT1 (IC₅₀?=?13.60?±?2.81?μM) and OCT2 (IC₅₀?=10.80?±?1.16?μM).

4.?Our study suggested tryptanthrin and chelerythrine could potently impact on the drug transport via specific OATs/OCTs. Therefore, the co-administration of these alkaloids with drugs could have clinical consequences due to drug–drug/herb interactions. Precautions should be warranted in the multi-drug therapies involving these alkaloids.     

秋菊丸化学成分鉴定及靶向GLUT9-OAT3尿酸转运体介导慢性高尿酸血症大鼠尿酸代谢和肾保护的机制研究

目的 初步明确秋菊丸化学成分,研究秋菊丸对慢性高尿酸血症（HUA）模型大鼠尿酸（UA）升高及肾脏损伤的治疗作用及机制。方法 借助超高效液相色谱串联四极杆静电场轨道阱质谱（UPLC-Q-Exactive Orbitrap MS）技术,初步鉴定秋菊丸的化学成分。48只雄性SD大鼠随机分成对照组、模型组、苯溴马隆（5.45 mg·kg^-1,阳性药）组和秋菊丸低、中、高剂量（1.31、2.62、5.24 g·kg^-1）组,除对照组外,通过ig腺嘌呤和乙胺丁醇制备大鼠慢性HUA模型,造模同时每天ig给药1次,连续28 d。使用全自动生化仪测定大鼠血清UA、肌酐（CRE）、尿素氮（BUN）水平;HE及Masson染色观察肾脏组织病理学变化;实时荧光定量PCR（qRT-PCR）法检测肾脏组织中葡萄糖转运蛋白9 （GLUT9）、有机阴离子转运体家族蛋白3 （OAT3）、ATP结合盒亚家族G成员2（ABCG2）、转化生长因子-β（TGF-β1）、SMAD蛋白3（Smad3）、α-平滑肌肌动蛋白（α-SMA）的mRNA水平。结果 秋菊丸中共鉴定出41个成分,包括黄酮类（9个）、有机酸类（5个）、生物碱类（3个）、苯丙素类（7个）、香豆素类（1个）、酚类（3个）、呋喃类（2个）、脂肪酰类（6个）、醌类（2个）、萜类（1个）、内酯类（1个）、脂肪酸类（1个）。给药28 d后,HE染色结果表明,与模型组比较,各给药组肾损伤的病理学改变明显恢复,减轻了肾小球萎缩、肾小管扩张、肾纤维化及肾间质炎性细胞浸润等病理改变,其中秋菊丸高剂量组及苯溴马隆组肾脏损伤最轻。与模型组比较,秋菊丸高剂量组的CRE、UA水平均显著降低（P＜0.01）,各剂量组BUN水平有降低趋势,但无显著性差异;高、中剂量组肾组织中肾小管上皮细胞中胶原蛋白的含量显著降低（P＜0.05、0.01）;高剂量组GLUT9 mRNA表达量显著减少（P＜0.05、0.01）,各剂量组OAT3、ABCG2的mRNA表达量均显著增加（P＜0.05、0.01）;中、高剂量α-SMA mRNA表达量显著减少（P＜0.05、0.01）,高剂量组TGF-β1 mRNA表达量显著减少（P＜0.01）,各给药组Smad3的mRNA表达量有减少趋势,但无显著性差异。结论 初步明确秋菊丸化成成分,秋菊丸具有增强UA代谢、减轻HUA所致肾脏损伤及肾纤维化的作用,其机制可能与调控GLUT9-OAT3尿酸转运体相关。     

Role of organic anion and amino acid carriers in transport of inorganic mercury in rat renal basolateral membrane vesicles: influence of compensatory renal growth.

Susceptibility to renal injury induced by inorganic mercury (Hg(2+)) increases significantly as a result of compensatory renal growth (following reductions of renal mass). We hypothesize that this phenomenon is related in part to increased basolateral uptake of Hg(2+) by proximal tubular cells. To determine the mechanistic roles of various transporters, we studied uptake of Hg(2+), in the form of biologically relevant Hg(2+)-thiol conjugates, using basolateral membrane (BLM) vesicles isolated from the kidney(s) of control and uninephrectomized (NPX) rats. Binding of Hg(2+) to membranes, accounted for 52-86% of total Hg(2+) associated with membrane vesicles exposed to HgCl(2), decreased with increasing concentrations of HgCl(2), and decreased slightly in the presence of sodium ions. Conjugation of Hg(2+) with thiols (glutathione, L-cysteine (Cys), N-acetyl-L-cysteine) reduced binding by more than 50%. Under all conditions, BLM vesicles from NPX rats exhibited a markedly lower proportion of binding. Of the Hg(2+)-thiol conjugates studied, transport of Hg-(Cys)(2) was fastest. Selective inhibition of BLM carriers implicated the involvement of organic anion transporter(s) (Oat1 and/or Oat3; Slc22a6 and Slc22a8), amino acid transporter system ASC (Slc7a10), the dibasic amino acid transporter (Slc3a1), and the sodium-dicarboxylate carrier (SDCT2 or NADC3; Slc13a3). Uptake of each mercuric conjugate, when factored by membrane protein content, was higher in BLM vesicles from uninephrectomized (NPX) rats, with specific increases in transport by the carriers noted above. These results support the hypothesis that compensatory renal growth is associated with increased uptake of Hg(2+) in proximal tubular cells and we have identified specific transporters involved in the process.     

槲皮素对尿酸性肾病大鼠肾损伤的作用机制研究

目的 基于槲皮素对尿毒素相关转运蛋白的调控规律,探讨其对尿酸性肾病大鼠肾损伤的作用机制.方法 通过每天灌胃给予100 mg·kg-1腺嘌呤、10％酵母粉饲料喂养构建尿酸性肾病大鼠模型.按照体重将雄性SD大鼠随机分为3组:正常组、模型组和槲皮素组,每组7只.槲皮素组大鼠在高嘌呤饮食基础上每日灌胃给予15 mg·kg-1槲...     

Interaction and transport characteristics of mycophenolic acid and its glucuronide via human organic anion transporters hOAT1 and hOAT3

The immunosuppressant mycophenolate mofetil (MMF) is frequently administered with calcineurin inhibitors and corticosteroids to recipients of organ transplantations. However, the renal handling of the active metabolite mycophenolic acid (MPA) and 7-O-MPA-glucuronide (MPAG) has been unclear. The purpose of the present study was to assess the interaction of MPA and MPAG with the human renal organic anion transporters hOAT1 (SLC22A6) and hOAT3 (SLC22A8), by conducting uptake experiments using HEK293 cells stably expressing these transporters. MPA and MPAG inhibited the time-dependent uptake of p-[(14)C]aminohippurate by hOAT1 and that of [(3)H]estrone sulfate by hOAT3. The apparent 50% inhibitory concentration (IC(50)) of MPA for hOAT1 and hOAT3 was estimated at 10.7 and 1.5 microM, respectively. In the case of MPAG, the IC(50) values were calculated at 512.3 microM for hOAT1 and 69.1 microM for hOAT3. Eadie-Hofstee plot analyses showed that they inhibited hOAT1 noncompetitively and hOAT3 competitively. No inhibitory effects of tacrolimus, cyclosporin A and azathioprine on transport of p-[(14)C]aminohippurate by hOAT1 and of [(3)H]estrone sulfate by hOAT3 were observed. No transport of MPA by these transporters was observed. On the other hand, the uptake of MPAG into cells was stimulated by the expression of hOAT3, but not hOAT1. These findings propose the possibility that the administration of MMF decreases the renal clearance of drugs which are substrates of hOAT1 and hOAT3. Present data suggest that hOAT3 contributes to the renal tubular secretion of MPAG.     

肾小管上皮细胞特异性转运马兜铃酸机制研究进展

因应用不当或饮食污染摄入马兜铃酸I所引起的、以进展性间质纤维化为特征的急慢性肾炎称为马兜铃酸肾病或巴尔干地方性肾病。马兜铃酸I特异性损伤近端小管,而对肾脏其他组织细胞未表现出明显的直接损伤作用。因此,近曲小管上皮细胞通过有机阴离子蛋白1和3特异性摄入马兜铃酸I,是马兜铃酸I发挥特异性肾毒性作用的关键。近年来对肾小管摄取马兜铃酸I的机制已明确,但参与其在肾小管上皮细胞顶膜侧转运的蛋白鲜有报道。通过综述马兜铃酸I在肾小管的消除机制,以期为预防和治疗马兜铃酸肾病提供新靶点。     

Interaction characteristics of flavonoids with human organic anion transporter 1 (hOAT1) and 3 (hOAT3)

The present study aimed to investigate the interaction characteristics of flavonoids with human organic anion transporter 1 (hOAT1) and 3 (hOAT3). Five flavonoids (morin, silybin, naringin, naringenin and quercetin) were selected and their interaction characteristics with hOAT1 and hOAT3 were examined in MDCK cells overexpressing hOAT1 or hOAT3. Among tested flavonoids, morin and silybin exhibited significant inhibition effects on the cellular uptake of [3H]-para-aminohippuric acid ([3H]-PAH) in MDCK-hOAT1 cells with Ki of 0.46 microM and 24 microM, respectively, while all the tested flavonoids appeared to be less interactive with hOAT3 compared to hOAT1. A kinetic study suggested that morin and silybin inhibited hOAT1-mediated cellular uptake of [3H]-PAH in a competitive manner. Furthermore, morin and silybin were translocated by hOAT1 across the cellular membrane. In conclusion, the present study identified some of flavonoids as a new class of hOAT1 inhibitors, suggesting a potential for flavonoid-drug interactions via the modulation of hOAT1 activity.