Regulation of UDP-Glucuronosyltransferase 1A1 Expression and Activity by MicroRNA 491-3p
Regulation of UDP-Glucuronosyltransferase 1A1 Expression and Activity by MicroRNA 491-3p
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DOI：
10.1124/jpet.113.210658
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发表时间：
2014-03-01
影响因子：
3.5
通讯作者：
Lazarus, Philip
中科院分区：
文献类型：
--
作者：
Dluzen, Douglas F.;Sun, Dongxiao;Lazarus, Philip
udp -葡萄糖醛酸糖基转移酶（UGT） 1A酶参与了许多重要的内源性和外源性化合物的II期代谢。九种UGT1A亚型在个体间表现出较高的表达差异，但其表观遗传调控尚不清楚。本研究的目的是研究microRNA （miRNA）对肝脏UGT1A酶的调节，并确定这种调节是否影响酶的活性。计算机分析发现，miRNA 4913p （miR-491-3p）通过与所有UGT1A酶共有的UGT1A 39-非翻译区结合，成为UGT1A基因家族的潜在调节剂。转染miR-491-3p mimic后，HuH-7细胞中UGT1A1 （P < 0.001）、UGT1A3 （P < 0.05）和UGT1A6 (P < 0.05) mRNA水平均显著降低。对于UGT1A1，这种抑制与雷洛昔芬代谢成雷洛昔芬-6-葡糖苷（ral-6-gluc, P < 0.01）和雷洛昔芬-49-葡糖苷（ral-49-gluc， P, 0.01）的显著降低相关。在miR-491-3p表达被抑制的HuH-7细胞中，UGT1A1 mRNA显著升高（相似值为80%，P < 0.01），雷洛昔芬糖醛酸化成ral-6-gluc （50%, P < 0.05）和ral-49-gluc （22%, P < 0.01）也相应升高。HepG2细胞中内源性miR-491-3p的敲低并未显著改变UGT1A1 mRNA水平，但确实增加了ral-6-gluc （50%, P < 0.05）和ral-49-gluc （34%, P < 0.001）的形成。在一组正常人肝脏标本中，miR-491-3p的表达与UGT1A3 （P < 0.05）和UGT1A6 (P < 0.01) mRNA水平呈显著负相关，而在未表达miR-491-3p的肝脏标本与表达miR-491-3p的肝脏标本中，UGT1A3和UGT1A6 mRNA水平显著（P, 0.05）升高。这些结果提示miR-491-3p是体内调节UGT1A酶表达的重要因子。
The UDP-glucuronosyltransferase (UGT) 1A enzymes are involved in the phase II metabolism of many important endogenous and exogenous compounds. The nine UGT1A isoforms exhibit high interindividual differences in expression, but their epigenetic regulation is not well understood. The purpose of the present study was to examine microRNA (miRNA) regulation of hepatic UGT1A enzymes and determine whether or not that regulation impacts enzymatic activity. In silico analysis identified miRNA 4913p (miR-491-3p) as a potential regulator of the UGT1A gene family via binding to the shared UGT1A 39-untranslated region common to all UGT1A enzymes. Transfection of miR-491-3p mimic into HuH-7 cells significantly repressed UGT1A1 (P < 0.001), UGT1A3 (P < 0.05), and UGT1A6 (P < 0.05) mRNA levels. For UGT1A1, this repression correlated with significantly reduced metabolism of raloxifene into raloxifene-6-glucuronide (ral-6-gluc; P < 0.01) and raloxifene-49-glucuronide (ral-49-gluc; P, 0.01). In HuH-7 cells with repressed miR-491-3p expression, there was a significant increase (similar to 80%; P < 0.01) in UGT1A1 mRNA and a corresponding increase in glucuronidation of raloxifene into ral-6-gluc (50%; P < 0.05) and ral-49-gluc (22%; P < 0.01). Knockdown of endogenous miR-491-3p in HepG2 cells did not significantly alter UGT1A1 mRNA levels but did increase the formation of ral-6-gluc (50%; P < 0.05) and ral-49-gluc (34%; P < 0.001). A significant inverse correlation between miR-491-3p expression and both UGT1A3 (P < 0.05) and UGT1A6 (P < 0.01) mRNA levels was observed in a panel of normal human liver specimens, with a significant (P, 0.05) increase in UGT1A3 and UGT1A6 mRNA levels observed in miR-491-3p nonexpressing versus expressing liver specimens. These results suggest that miR-491-3p is an important factor in regulating the expression of UGT1A enzymes in vivo.