Study on the relationship between Parkinson's disease and Diacylglycerol kinase θ
Parkinson's disease (PD) is one of the neurological disorders associated with aging and caused by the death of dopamine (DA) secretory cells. Recently, genome wide association study on non-Hispanic whites and Chinese Han revealed that the same single nucleotide polymorphism (SNP) was found between exon 2 and 3 of diacylglycerol kinase θ (DGKθ) in PD patients. In addition, Phosphatidic acid (PA) produced by DGKθ binds to α-synuclein (α-sync), resulting in aggregation of α-sync. These facts suggested involvement of DGKθ in PD. However, the direct relationship between PD and DGKθ is completely unknown. So, this study was aimed to clarify the relationship between PD and DGKθ.
First, mRNA and protein levels of DGKθ were compared, in SH-SY5Y cells treated with KCl, H₂O₂ to mimic PD conditions. As a result, both mRNA and protein levels of DGKθ were elevated in the PD model cells. Next, to investigate the relationship between DGKθ and α-sync, SH-SY5Y cells overexpressing GFP and DGKθ-GFP were treated with KCl, H₂O₂, and aggregation of α-sync was examined by immunofluorescent staining. As a result, overexpression of DGKθ-GFP induced α-sync aggregation without KCl, H₂O₂ treatment.