Research Center for Chinese Herbal Medicine, College of Human Ecology, Chang Gung University of Science and Technology, Taoyuan, Taiwan.
Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Taoyuan, Taiwan.
Cell Death Dis. 2018 Jan 9;9(1):10. doi: 10.1038/s41419-017-0005-8.
Glucose-6-phosphate dehydrogenase (G6PD) is a housekeeping enzyme involved in the pentose phosphate shunt for producing nicotinamide adenine dinucleotide phosphate (NADPH). Severe G6PD deficiency leads to embryonic lethality, but the underlying mechanism is unclear. In the current study, the effects of G6PD on epithelial-mesenchymal transition (EMT), especially during embryonic development, were investigated. The knockdown of G6PD induced morphological changes, accompanied by the suppression of epithelial markers, E-cadherin and β-catenin, in A549 and MDCK cells. Such modulation of EMT was corroborated by the enhancement of migration ability in G6PD-knockdown A549 cells. Zebrafish embryos with g6pd knockdown exhibited downregulation of the E-cadherin/β-catenin adhesion molecules and impaired embryonic development through reduction in epiboly rate and increase in cell shedding at the embryo surface. The dysregulation in zebrafish embryonic development caused by g6pd knockdown could be rescued through human G6PD or CDH1 (E-cadherin gene) cRNA coinjection. The Smad3/miR-200b axis was dysregulated upon G6PD knockdown, and the reconstitution of SMAD3 in G6PD-knockdown A549 cells restored the expression of E-cadherin/β-catenin. The inhibition of NADPH oxidase (NOX) activation through the loss of p22 signaling was involved in the dysregulation of the Smad3/miR-200b axis upon G6PD knockdown. The reconstitution of G6PD led to the recovery of the regulation of NOX/Smad3/miR-200b signaling and increased the expression of E-cadherin/β-catenin in G6PD-knockdown cells. Thus, these results suggest that in the EMT process, G6PD plays an important regulatory role as an integral component of the NOX/Smad3/miR-200b axis.
葡萄糖-6-磷酸脱氢酶（G6PD）是一种参与戊糖磷酸途径产生烟酰胺腺嘌呤二核苷酸磷酸（NADPH）的管家酶。严重的 G6PD 缺乏会导致胚胎致死，但潜在的机制尚不清楚。在本研究中，研究了 G6PD 对上皮-间充质转化（EMT）的影响，特别是在胚胎发育过程中的作用。G6PD 的敲低诱导了形态变化，伴随着 A549 和 MDCK 细胞中上皮标志物 E-钙粘蛋白和β-连环蛋白的抑制。在 G6PD 敲低的 A549 细胞中，迁移能力的增强证实了 EMT 的这种调节。g6pd 敲低的斑马鱼胚胎表现出 E-钙粘蛋白/β-连环蛋白粘附分子的下调，并且通过胚盘覆盖率的降低和胚胎表面细胞脱落的增加而导致胚胎发育受损。通过人类 G6PD 或 CDH1（E-钙粘蛋白基因）cRNA 共注射可以挽救 g6pd 敲低引起的斑马鱼胚胎发育异常。G6PD 敲低后 Smad3/miR-200b 轴失调，在 G6PD 敲低的 A549 细胞中重建 SMAD3 恢复了 E-钙粘蛋白/β-连环蛋白的表达。通过 p22 信号的丧失抑制 NADPH 氧化酶（NOX）的激活，参与了 G6PD 敲低后 Smad3/miR-200b 轴的失调。G6PD 的重建导致 NOX/Smad3/miR-200b 信号的调节恢复，并增加了 G6PD 敲低细胞中 E-钙粘蛋白/β-连环蛋白的表达。因此，这些结果表明，在 EMT 过程中，G6PD 作为 NOX/Smad3/miR-200b 轴的一个组成部分，发挥着重要的调节作用。
