Hepatic and renal expression of organic anion transporters during jaundice, and improvement of transcellular organic anion transport after transfection with Multidrug Resistance-associated Protein 2(MRP2) gene.

家族性高胆红素血症患者胆红素UDP-葡萄糖基转移酶基因(UGT1A1)的各种突变已有报道。为了阐明该基因突变在日本人群中的发生率，我们调查了一组患有Crigler Najjar综合征(CNS)和Gilbert综合征(GS)的日本患者以及健康的无黄体症受试者中UGT1A1突变的存在。UGT1A1编码区的多态性在日本GS患者和正常人中普遍存在。高胆红素血症的遗传基础在日本人和高加索人中似乎是不同的。在这项研究中，我们还发现了一个新的突变，杂合子P364L。Gunn大鼠是一种I型中枢神经系统的动物模型，UGT1A1是一种I型中枢神经系统缺陷的动物模型。我们检测了有机阴离子转运多肽(OATP)1、OATP2、MULT…的表达Gunn大鼠肝、肾组织中的抗性相关蛋白(MRP)2和mrp3较多。高胆红素尿症大鼠(EHBR)是Dubin-Johnson综合征(Dubin-Johnson综合征)的动物模型，胆汁中胆红素葡萄糖醛酸苷排泄受损，导致黄疸。在EHBR中，mrp2的缺乏会导致大量有机阴离子的胆汁排泄缺陷。EHBR大鼠肝、肾组织中mrp3的表达明显高于SD大鼠。EHBR大鼠肝、肾组织中mrp1、mrp6基因的表达与SD大鼠无明显差异。Mrp1和mrp6蛋白在EHBR和SD大鼠的肝脏和肾脏中几乎不表达。与mrp3相反，EHBR大鼠肝脏中Oatp1和Oatp2mRNA的表达均低于SD大鼠。免疫组织化学显示肝和肾的mrp3蛋白定位于基底膜，构建了日本血凝病毒(HJV)囊膜蛋白包裹的人MRP2全长基因的蛋白表达载体pDEST_&lt；26&gt；。在EHBR上进行pDEST_&lt；26&gt；基因转染法。我们发现，转导MRP2后，结合胆红素在肝脏中的跨细胞转运从EHBR中恢复。转染组血清结合胆红素水平降至正常水平(35.7μ/L至6.4μ/L)。转EHBR组大鼠肝脏中MRP3表达降低，Oatp1或Oatp2表达增加，但与对照组相比差异无显着性。较少

Various mutations of bilirubin UDP-glucronosyltransferase gene (UGT1A1) have been reported in patients with familial unconjugated hyperbilirubinemia. To clarify the incidence of this gene mutation in the Japanese population, we investigated the presence of UGT1A1 mutation in a group of Japanese patients with Crigler Najjar syndrome(CNS) type 2 and Gilbert's syndrome(GS), as well as in healthy anicteric subjects. Polymorphisms in the coding region of UGT1A1 were commonly observed in Japanese patients with GS and in healthy subjects. The genetic basis of hyperbilirubinemia appears to be different between the Japanese population and Caucasians. In this study, we additionally identified a novel mutation, heterozygous P364L. The P364L UGT1A1 enzyme activity was 64.4% lower than the wild type enzyme activity.Gunn rat is an animal model of CNS type I. UGT1A1 has been reported to be deficient in CNS type 1. We evaluated expressions of organic anion transporting polypeptide(oatp) 1, oatp2, mult … More idrug resistance-associated protein(mrp) 2, and mrp3 in the liver and kidney of Gunn rats. Decreased expression of oatpl and increased expression of mrp3 were observed in the liver and kidney of Gunn rats.Eisai hyperbilirubinuria rat(EHBR) is an animal model of Dubin-Johnson syndrome that suffers from jaundice due to impaired biliary excretion of bilirubin glucuronides. In EHBR, deficiency of mrp2 causes defective biliary excretion of numerous organic anions. Hepatic and renal expression of mrp3 was significantly higher in EHBR than in SD rats. Hepatic and renal expression of mrp1 and mrp6 mRNA was not significantly different between EHBR and SD rats. Mrp1 and mrp6 proteins were hardly expressed in liver and kidney of both EHBR and SD rats. In contrast to mrp3, hepatic expression of oatp1 and oatp2 mRNA were lower in EHBR than in SD rats. Immunohistochemistry disclosed that hepatic and renal mrp3 protein was localized at the basolateral membrane.We developed a protein expression vector (pDEST_<26>) which includes the full length of human MRP2 cDNA, which is encapsulated by the envelope protein of the hemoagglutinating virus of Japan (HJV). Gene transfection with pDEST_<26> was performed on EHBR. We disclosed that transcellular transport of conjugated bilirubin was recovered in the liver from EHBR after transfection with MRP2. Serum conjugated bilirubin level decreased to normal levels in EHBR (35.7 μmol/L to 6.4 μmol/L) after transfection. Mrp3 expression decreased while Oatp1 or Oatp2 expression increased in the liver from transfected EHBR but these expressions were not significantly different from control SD rats. Less