Udomsinprasert Wanvisa, Kitkumthorn Nakarin, Mutirangura Apiwat, Chongsrisawat Voranush, Poovorawan Yong, Honsawek Sittisak
Department of Biochemistry, Faculty of Medicine, Chulalongkorn University, King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, Thailand.
Department of Oral and Biology, Faculty of Dentistry, Mahidol University, Bangkok, Thailand.
PLoS One. 2017 Jan 4;12(1):e0169306. doi: 10.1371/journal.pone.0169306. eCollection 2017.
Biliary atresia (BA) is a progressive fibroinflammatory liver disease. Autotaxin (ATX) has a profibrotic effect resulting from lysophosphatidic acid activity. The purpose of this study was to examine ATX expression and ATX promoter methylation in peripheral blood leukocytes and liver tissues from BA patients and controls and investigate their associations with outcome parameters in BA patients.
A total of 130 subjects (65 BA patients and 65 age-matched controls) were enrolled. DNA was extracted from circulating leukocytes and liver tissues of BA patients and from and age-matched controls. ATX promoter methylation status was determined by bisulfite pyrosequencing. ATX expression was analyzed using quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay.
Decreased methylation of specific CpGs were observed at the ATX promoter in BA patients. Subsequent analysis revealed that BA patients with advanced stage had lower methylation levels of ATX promoter than those with early stage. ATX promoter methylation levels were found to be associated with hepatic dysfunction in BA. In addition, ATX expression was significantly elevated and correlated with a decrease in ATX promoter methylation in BA patients compared to the controls. Furthermore, promoter hypomethylation and overexpression of ATX were inversely associated with jaundice status, hepatic dysfunction, and liver stiffness in BA patients.
Accordingly, it has been hypothesized that ATX promoter methylation and ATX expression in peripheral blood may serve as possible biomarkers reflecting the progression of liver fibrosis in postoperative BA. These findings suggest that the promoter hypomethylation and overexpression of ATX might play a contributory role in the pathogenesis of liver fibrosis in BA.
胆道闭锁（BA）是一种进行性纤维炎性肝病。自分泌运动因子（ATX）因溶血磷脂酸活性而具有促纤维化作用。本研究的目的是检测BA患者和对照组外周血白细胞及肝组织中ATX的表达和ATX启动子甲基化情况，并研究它们与BA患者预后参数的相关性。
共纳入130名受试者（65例BA患者和65例年龄匹配的对照组）。从BA患者的循环白细胞和肝组织以及年龄匹配的对照组中提取DNA。通过亚硫酸氢盐焦磷酸测序法测定ATX启动子甲基化状态。使用定量实时聚合酶链反应和酶联免疫吸附测定法分析ATX表达。
在BA患者的ATX启动子处观察到特定CpG的甲基化降低。随后的分析显示，晚期BA患者的ATX启动子甲基化水平低于早期患者。发现ATX启动子甲基化水平与BA患者的肝功能障碍有关。此外，与对照组相比，BA患者中ATX表达显著升高且与ATX启动子甲基化降低相关。此外，ATX启动子低甲基化和过表达与BA患者的黄疸状态、肝功能障碍和肝脏硬度呈负相关。
因此，有人推测外周血中ATX启动子甲基化和ATX表达可能作为反映术后BA肝纤维化进展的潜在生物标志物。这些发现表明，ATX启动子低甲基化和过表达可能在BA肝纤维化的发病机制中起作用。
