Yingxiao Shi, Shaoyu Lin, Kim A Staats, Yichen Li, Wen-Hsuan Chang, Shu-Ting Hung, Eric Hendricks, Gabriel R Linares, Yaoming Wang, Esther Y Son, Xinmei Wen, Kassandra Kisler, Brent Wilkinson, Louise Menendez, Tohru Sugawara, Phillip Woolwine, Mickey Huang, Michael J Cowan, Brandon Ge, Nicole Koutsodendris, Kaitlin P Sandor, Jacob Komberg, Vamshidhar R Vangoor, Ketharini Senthilkumar, Valerie Hennes, Carina Seah, Amy R Nelson, Tze-Yuan Cheng, Shih-Jong J Lee, Paul R August, Jason A Chen, Nicholas Wisniewski, Victor Hanson-Smith, T Grant Belgard, Alice Zhang, Marcelo Coba, Chris Grunseich, Michael E Ward, Leonard H van den Berg, R Jeroen Pasterkamp, Davide Trotti, Berislav V Zlokovic, Justin K Ichida
An intronic GGGGCC repeat expansion in C9ORF72 is the most common cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), but the pathogenic mechanism of this repeat remains unclear. Using human induced motor neurons (iMNs), we found that repeat-expanded C9ORF72 was haploinsufficient in ALS. We found that C9ORF72 interacted with endosomes and was required for normal vesicle trafficking and lysosomal biogenesis in motor neurons. Repeat expansion reduced C9ORF72 expression, triggering neurodegeneration through two mechanisms: accumulation of glutamate receptors, leading to excitotoxicity, and impaired clearance of neurotoxic dipeptide repeat proteins derived from the repeat expansion...
March 2018: Nature Medicine