School of Biomedical Sciences is pleased to invite you to join the following seminar:

Date: Wednesday, March 2, 2022

Time: 2:00 pm – 3:30 pm

Via Zoom:  https://hku.zoom.us/j/97416970401?pwd=NDBqdmxrb0xSZnhiTlNYenBJLzFoQT09

Meeting ID: 974 1697 0401

Password: 316206

Speaker: Professor Chi-chung Hui, Senior Scientist, Developmental & Stem Cell Biology, The Hospital for Sick Children and Professor of Molecular Genetics, University of Toronto

Title: "Hypothalamic functions of Irx3 and Irx5 in obesity and feeding regulation”

Biography

Dr. Chi-chung Hui is Professor of Molecular Genetics at University of Toronto and Senior Scientist in the Program in Developmental & Stem Cell Biology of the Hospital for Sick Children Research Institute. He is also a Tier 1 Canada Research Chair in Mouse Development and Disease Modeling. His research focuses on Hedgehog signaling and Iroquois homeobox (Irx) genes in development and disease. He published more than 150 research papers in leading journals including Nature, Cell, Science and New England Journal of Medicine. To date, his work was cited over 30,000 times with an h-index of 78.  In the past 2 decades, Dr. Hui has been actively involved in promoting research and educational collaborations between Canada and China. He is an Honorary Professor in the School of Biomedical Sciences of the University of Hong Kong and an Executive Member of the Joint Institute of Genetics and Genome Medicine at Zhejiang University and University of Toronto. In recent years, his research interests center on the function of Irx3 and Irx5 in metabolic regulation and obesity.

Abstract

Hypothalamic neurons are largely responsible for the regulation of energy homeostasis. These neurons are mainly born during embryogenesis, followed by a second wave of neurogenesis in the first postnatal month that contributes to the development of the adult hypothalamus. The Iroquois homeobox genes IRX3 and IRX5 are involved in various developmental processes and have been implicated as determinants of human obesity in connection with the intronic variants of FTO, which are the strongest obesity genetic risk factors in human populations. By using mouse genetics and single-cell analysis, our recent studies have provided physiological and molecular evidence of the regulatory function of Irx3 and Irx5 in hypothalamus development and energy homeostasis. We identified a novel radial glia-like neural stem cell (NSC) population, representing a bona fide population of NSCs in the arcuate nucleus of postnatal mouse hypothalamus, and found that Irx3 and Irx5 are predominantly expressed in this NSCs population and critical for postnatal neurogenesis and hypothalamic leptin response in feeding control. We also discovered that ectopic expression of Irx3 and Irx5 in these neurons contributes to the neurodevelopmental defects leading to uncontrolled overeating in Sim1 haploinsufficiency, which is associated with hyperphagic childhood-obesity in humans. In this talk, I will be discussing these results.

ALL ARE WELCOME

Should you have any enquiries, please feel free to contact Miss Veronica Kwok at 3917 9515.