Calligaris Sebastián, Cekic Dean, Roca-Burgos Leslye, Gerin Fabio, Mazzone Graciela, Ostrow J Donald, Tiribelli Claudio
Centro Studi Fegato, Bld Q, AREA Science Park, Basovizza Campus, ss 14 Km 163.5, 34012 Trieste, Italy.
FEBS Lett. 2006 Feb 20;580(5):1355-9. doi: 10.1016/j.febslet.2006.01.056. Epub 2006 Jan 26.
We have shown that multidrug resistance associated protein 1 (MRP1) mediates ATP-dependent extrusion of bilirubin, possibly limiting its potentially toxic accumulation in cells. To determine directly if Mrp1 protects cells against unconjugated bilirubin (UCB) toxicity, mouse embryo fibroblasts (MEF) were isolated from Mrp1 knockout (-/-) mice and their wild type (WT) (+/+) littermates. Compared to WT cells, cultured MEF (-/-) cells exposed to 40-140 nM unbound [H3]-bilirubin accumulated twice as much [H3]-bilirubin (P<0.01). This was associated with greater, dose-related cytotoxicity, assessed by the methylthiazoletetrazolium test, lactate dehydrogenase release and cellular ATP content. The data confirm that Mrp1 limits intracellular accumulation of UCB and thus decreases its cytotoxicity.
我们已经表明，多药耐药相关蛋白1（MRP1）介导胆红素的ATP依赖性外排，这可能限制了其在细胞内潜在的毒性蓄积。为了直接确定Mrp1是否能保护细胞免受未结合胆红素（UCB）的毒性影响，从小鼠胚胎成纤维细胞（MEF）的Mrp1基因敲除（-/-）小鼠及其野生型（WT）（+/ +）同窝小鼠中分离细胞。与野生型细胞相比，培养的MEF（-/-）细胞暴露于40 - 140 nM未结合的[H3] - 胆红素时，[H3] - 胆红素的蓄积量是野生型细胞的两倍（P < 0.01）。通过噻唑蓝试验、乳酸脱氢酶释放和细胞ATP含量评估，这与更大的、剂量相关的细胞毒性有关。数据证实Mrp1限制了UCB在细胞内的蓄积，从而降低了其细胞毒性。
