Wang Libin, Sewell William F, Kim Sang D, Shin Jordan T, MacRae Calum A, Zon Leonard I, Seidman J G, Seidman Christine E
Harvard Medical School, Department of Genetics, and Howard Hughes Medical Institute, Division of Hematology/Oncology, Children's Hospital Boston, 77 Avenue Louis Pasteur, Boston, MA 02115, USA.
Development. 2008 Oct;135(20):3425-34. doi: 10.1242/dev.012237. Epub 2008 Sep 17.
To investigate the mechanisms by which mutations in the human transcriptional co-activator EYA4 gene cause sensorineural hearing loss that can occur in association with dilated cardiomyopathy, we studied eya4 expression during zebrafish development and characterized eya4 deficiency. eya4 morphant fish embryos had reduced numbers of hair cells in the otic vesicle and lateral line neuromasts with impaired sensory responses. Analyses of candidate genes that are known to be expressed in a temporal and spatial pattern comparable to eya4 focused our analyses on atp1b2b, which encodes the beta2b subunit of the zebrafish Na+/K+-ATPase. We demonstrate atp1b2b levels are reduced in eya4 morphant fish and that morpholino oligonucleotides targeting the atp1b2b gene recapitulated the eya4 deficiency phenotypes, including heart failure, decreased sensory hair cell numbers in the otic vesicle and neuromasts, and abnormal sensory responses. Furthermore, atp1b2b overexpression rescued these phenotypes in eya4 morphant fish. We conclude that eya4 regulation of Na+/K+-ATPase is crucial for the development of mechanosensory cells and the maintenance of cardiac function in zebrafish.
为了研究人类转录共激活因子EYA4基因突变导致感音神经性听力损失（可与扩张型心肌病相关发生）的机制，我们研究了斑马鱼发育过程中eya4的表达，并对eya4缺陷进行了表征。eya4 morphant鱼胚胎的耳泡和侧线神经丘中的毛细胞数量减少，感觉反应受损。对已知在时间和空间模式上与eya4相当的候选基因进行分析后，我们将分析重点放在了atp1b2b上，它编码斑马鱼Na+/K+-ATP酶的β2b亚基。我们证明eya4 morphant鱼中atp1b2b水平降低，并且靶向atp1b2b基因的吗啉代寡核苷酸重现了eya4缺陷表型，包括心力衰竭、耳泡和神经丘中感觉毛细胞数量减少以及异常的感觉反应。此外，atp1b2b过表达挽救了eya4 morphant鱼中的这些表型。我们得出结论，eya4对Na+/K+-ATP酶的调节对于斑马鱼机械感觉细胞的发育和心脏功能的维持至关重要。
