GBA Deficiency Promotes α-Synuclein Accumulation in Cellular Models of Parkinson’s Disease

Parkinson’s Disease (PD) is characterized by progressive neuronal degeneration, reduced dopamine levels, and aggregation of the protein ⍺-synuclein, leading to the formation of Lewy bodies. Mutations in the GBA1 gene, which encodes the enzyme glucocerebrosidase (GBA), have been linked to PD. GBA hydrolyzes glucosylceramides (GlcCer) into ceramide and glucose. A loss-of-function mutation causes lipid accumulation in lysosomes, disrupting cellular function. This study investigated how GBA knockouts affect ⍺-synuclein accumulation in neuronal cell lines. SK-N-SH and SH-SY5Y cells were chosen to examine cellular apoptosis and ⍺-synuclein levels, providing a model for studying neurodegenerative processes and cellular effects of GBA depletion.1 GBA was knocked out in both lines, with colonies screened through PCR and confirmed by western blot. Knockout lines showed reduced growth and altered morphology compared to wild type cells. Apoptosis markers were elevated in both knockout lines, indicating increased neuronal cell death. Analysis of ⍺-synuclein levels in the SH-SY5Y cells exhibited increased ⍺-synuclein aggregation and accumulation, whereas SK-N-SH cells had a decrease with GBA knocked out. Other tested cell types also showed elevated ⍺-synuclein accumulation. In SH-SY5Y cells, the absence of GBA promotes aggregation, while SK-N-SH cells have opposite effects. This highlights the importance of cellular context in PD mechanisms and suggests that GBA may have variable effects depending on cell type.