关于举办“Circadian clock and liver polyploidization”学术报告的通知

　　报告题目：Circadian clock and liver polyploidization

　　报告人：台北医科大学 赵需文助理教授

　　报告时间：2018年3月14日下午2:00-4:00

　　报告地点：北校区动物医学院4号教学楼4245会议室

　　报告摘要:

　　Liver metabolism undergoes robust circadian oscillations in gene expression and enzymatic activity essential for liver homeostasis, but whether the circadian clock controls homeostatic self-renewal of hepatocytes is unknown. Here we show that hepatocyte polyploidization is markedly accelerated around the central vein, the site of permanent cell self-renewal, in mice deficient in circadian Period genes. In these mice, a massive accumulation of hyperpolyploid mononuclear and binuclear hepatocytes occurs due to impaired mitogen-activated protein kinase phosphatase 1 (Mkp1)-mediated circadian modulation of the extracellular signal regulated kinase (Erk1/2) activity. Time-lapse imaging of hepatocytes suggests that the reduced activity of Erk1/2 in the midbody during cytokinesis results in abscission failure, leading to polyploidization. Manipulation of Mkp1 phosphatase activity is sufficient to change the ploidy level of hepatocytes. These data provide clear evidence that the Period genes not only orchestrate dynamic changes in metabolic activity, but also regulate homeostatic selfrenewal of hepatocytes through Mkp1-Erk1/2 signaling pathway.

　　报告人简介：

　　赵需文助理教授，2010年毕业于台湾国防生科所，获博士学位；2010-2011年，台湾中央研究院生物医学研究所博士后；2011-2015年，日本京都大学博士后；2016年至今任台北医科大学医学院生理系助理教授。赵博士研究兴趣主要集中于神经科学和生物钟领域。在神经科学研究领域，赵博士的研究首先发现到sumoylation的修饰过程对于神经发育的重要性；另外，赵博士在RNA调控方面的研究也发现了RNA translation对于神经突触功能调节的重要影响。在生物钟研究领域，赵博士的研究首先发现到，生物钟基因敲除除了影响生物日夜周期行为之外，更能调控影响肝细胞在发育过程当中产生多倍体的过程。截至目前，赵博士共在Journal of Cell Biology、Journal of Clinical Investigation、Nucleic Acids Research、Nature communications、Cell Reports、Journal of Neuroscience等国际著名期刊发表学术论文8篇。

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动物医学院

2018年3月10日