Henderson et al., 2020, Neuron 105, 1–15; https://doi.org/10.1016/j.neuron.2019.12.004
Henderson et al. use cell and animal models of Parkinson’s disease to show that reducing glucocerebrosidase activity leads to an enhancement of pre-existing alpha-synuclein pathology that does not depend on neuron type, reconciling experimental biology with human epidemiology.
Mutations in the GBA1 gene are the most common genetic risk factor for Parkinson’s disease (PD) and dementia with Lewy bodies (DLB). GBA1 encodes the lysosomal lipid hydrolase glucocerebrosidase (GCase), and its activity has been linked to accumulation of alpha-synuclein. The current study systematically examines the relationship between GCase activity and both pathogenic and non-pathogenic forms of alpha-synuclein in primary hippocampal, cortical, and midbrain neuron and astrocyte cultures, as well as in transgenic mice and a non-transgenic mouse model of PD. We find that reduced GCase activity does not result in aggregation of alpha-synuclein. However, in the context of extant misfolded alpha-synuclein, GCase activity modulates neuronal susceptibility to pathology. Furthermore, this modulation does not depend on neuron type but rather is driven by the level of pathological alpha-synuclein seeds. This study has implications for understanding how GBA1 mutations influence PD pathogenesis and provides a platform for testing novel therapeutics.
Michael X. Henderson,1,9, Samantha Sedor,1 Ian McGeary,1 Eli J. Cornblath,2,4 Chao Peng,1 Dawn M. Riddle,1 Howard L. Li,1 Bin Zhang,1 Hannah J. Brown,1 Modupe F. Olufemi,1 Danielle S. Bassett,2,3,5,6,7,8 John Q. Trojanowski,1 and Virginia M.Y. Lee1