Examining the function of NuMA and TPX2 in neurite morphogenesis

• Main Authors: Chen, Wen-Shin, 陳雯馨
• Other Authors: Hwang, Eric
• Format: Others
• Language: en_US
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/20644744795296944737

碩士 === 國立交通大學 === 生物資訊及系統生物研究所 === 99 === A functional nervous system depends on the intricate connections between neurons. For neuronal circuits to be correctly wired, connections of each neuron must be properly regulated to establish an effective neural network. Neuritogenesis is an important neurite developmental process that ensures proper neuronal connections are established. It has been shown that microtubule cytoskeleton and microtubule-associated proteins are important regulators of neuritogenesis. The microtubule cytoskeleton plays an indispensable role in each of the steps during neuritogenesis. Two microtubule-associated proteins, NuMA and TPX2 play critical roles in mitosis. NuMA is an essential mitotic component to establish and maintain focused spindle pole and TPX2 is required to generate a stable bipolar spindle. Interestingly, NuMA and TPX2 localize to the nucleus during interphase or post-mitotic cells (such as neurons). However, the non-mitotic functions of NuMA and TPX2 remained elusive. A previous study showed that suppressing NuMA or TPX2 in P19-differentiated neurons resulted in shortens neurites. To confirm this effect, mouse primary hippocampal neurons are transfected with plasmids which express EGFP as a report gene and also can be transcribed into shRNA targets NuMA or TPX2. Then neurons are analyzed if NuMA or TPX2 suppressed neurite elongation. In this study, we established a novel method to culture dissociated mouse hippocampal neurons. Our method significantly simplifies the preparation while produces healthy and long-lived neuronal cultures. We also confirmed that NuMA and TPX2 indeed involve in neurite outgrowth. Suppressing NuMA or TPX2 in mouse hippocampal neurons resulted in reduced neurite number. Moreover, overexpressing human NuMA and TPX2 partially rescued the reduction of neurites. Those results suggest that both NuMA and TPX2 play important roles in neuritogenesis.