Bilirubin glucuronidation by intact Gunn rat fibroblasts expressing bilirubin UDP-glucuronosyltransferase.
Bilirubin glucuronidation by intact Gunn rat fibroblasts expressing bilirubin UDP-glucuronosyltransferase.
复制标题
表达胆红素 UDP-葡萄糖醛酸基转移酶的完整 Gunn 大鼠成纤维细胞的胆红素葡萄糖醛酸化。
DOI：
10.1042/bj3140477
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
OudeElferink,RP
中科院分区：
文献类型：
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作者：
Seppen,J;Tada,K;Hellwig,S;Bakker,CT;Prasad,VR;RoyChowdhury,N;RoyChowdhury,J;Bosma,PJ;OudeElferink,RP
Crigler-Najjar（CN）病是一种遗传性胆红素代谢紊乱。这种疾病是由肝酶胆红素UDP-葡萄糖醛酸转移酶（B-UGT）缺乏引起的。CN病患者血清中毒性化合物非结合胆红素水平较高。CN患者胆红素代谢的唯一缺陷是缺乏B-UGT活性。因此，移植能够使胆红素葡萄糖醛酸化的细胞应降低血清胆红素水平。古恩大鼠是CN病的动物模型。原代古恩大鼠成纤维细胞（GURF）转导重组逆转录病毒，能够转移B-UGT cDNA。获得了表达B-UGT的细胞系，其表达水平与肝细胞相当。加入到这些细胞培养基中的胆红素被葡萄糖醛酸化并排出体外。在不同胆红素浓度下比较了转导的GURF和新鲜分离的Wistar肝细胞的B-UGT活性。当培养基中存在生理胆红素浓度（5-10 μM）时，这两种细胞类型的比B-UGT活性相当。在较高胆红素浓度（20-80 μM）下，肝细胞比转导的GURF更活跃。我们的结论是，只有一种酶（B-UGT）的加入，成纤维细胞可以进行胆红素葡萄糖醛酸化所需的全套反应。在20-80 μM胆红素下，转导的GURF和肝细胞之间B-UGT活性的差异可以通过GURF中较低的UDP-葡萄糖醛酸和谷胱甘肽S-转移酶水平来解释。我们的研究结果还表明，这些细胞可用于开发肝外基因治疗CN疾病。
Crigler–Najjar (CN) disease is an inherited disorder of bilirubin metabolism. The disease is caused by a deficiency of the hepatic enzyme bilirubin UDP-glucuronosyltransferase (B-UGT). Patients with CN disease have high serum levels of the toxic compound, unconjugated bilirubin. The only defect in bilirubin metabolism of CN patients is the absence of B-UGT activity. The transplantation of cells able to glucuronidate bilirubin should therefore lower serum bilirubin levels. The Gunn rat is the animal model of CN disease. Primary Gunn rat fibroblasts (GURF) were transduced with a recombinant retrovirus, capable of transferring B-UGT cDNA. A cell line was obtained expressing B-UGT at a level comparable to hepatocytes. Bilirubin added to the culture medium of these cells was glucuronidated and excreted. The B-UGT activities of transduced GURF and freshly isolated Wistar hepatocytes were compared at different bilirubin concentrations. The specific B-UGT activities of these two cell types were comparable when physiological bilirubin concentrations (5–10 μM) were present in the culture media. At higher bilirubin concentrations (20–80 μM) the hepatocytes were more active than the transduced GURF. We conclude that with the addition of only one enzyme (B-UGT) fibroblasts can perform the complete set of reactions necessary for bilirubin glucuronidation. The difference in B-UGT activity between transduced GURF and hepatocytes at 20-80 μM bilirubin can be explained by lower UDP-glucuronic acid and glutathione S-transferase levels in GURF. Our findings also indicate that these cells could be used to develop extrahepatic gene therapy for CN disease.