Objective: To evaluate the perceptivity of mTOR kinase activity inhibition for Parkinson’s disease therapy (PD).
Background: The protein kinase mTOR is currently considered as a potential therapeutic target for the treatment of neurodegenerative diseases, the pathogenesis of which is based on the accumulation of proteins due to a possible disruption of the autophagy lysosomal pathway. However, hyper- and hypo-activation of mTOR can lead to lysosomal dysfunction and subsequent cell death.
Method: Enzyme activities (glucoceresobridase (GCase), alpha-galactosidase (GLA), acid sphingomyelinase (ASMase)) and concentration of their substrates (hexosylsphingosine (HexSph), globotriaosylsphingosine (LysoGb3), lysosphingomyelin (LysoSM)) were measured triplicate by LC-MS/MS; protein levels of phosphorylated mTOR (Ser2448) (p-mTOR), LC3B-II, GCase and alpha-synuclein (monomeric, phosphorylated (Ser129) (p-alpha-synuclein), tetrameric) were measured triplicate by western blot; colocalization LC3B with lysosomes were measured by immunofluorescence analysis in treated peripheral blood monocyte-derived macrophages (PBMDM) from 6 neurological healthy individuals and in SH-SY5Y neuroblastoma cell line (SH-SY5Y) with 25, 50, 100, 200 nmol of mTOR kinase inhibitor Torin1.
Results: LC3B-II protein level and its colocalization with lysosomes were increased in treated PBMDM and SH-SY5Y with Torin1 (p<0.05). 100 nmol Torin1 led to no alterations in the lysosomal enzyme activities and the concentration of lysosphingolipids in treated PBMDM and SH-SY5Y compared to untreated cells (p>0.05). Other concentrations of Torin 1 led to decreased enzyme activities and increased lysosphingolipid concentrations. Increase GCase protein level encoded by the GBA1 gene was shown in treated PBMDM and SH-SY5Y with 100 nmol Torin1 compared to untreated cells (p<0.01). Decreased toxic p-alpha-synuclein protein and increased stable tetrameric form of alpha-synuclein to aggregation were found in treated SH-SY5Y with 100, 200 nmol Torin1 compared to untreated cells (p<0.01).
Conclusion: Inhibition of the protein kinase mTOR by Torin1 may be a promising approach for developing therapy for PD, in particular, GBA1-associated PD.
The study was supported by Russian Science Foundation grant No. 24-25-00212
To cite this abstract in AMA style:
A. Bezrukova, K. Basharova, G. Baydakova, E. Zakharova, S. Pchelina, T. Usenko. Dose-dependent alterations of lysosomal activity and alpha-synuclein level in peripheral blood monocyte-derived macrophages and SH-SY5Y neuroblastoma cell line by upon inhibition of mTOR kinase activity [abstract]. Mov Disord. 2024; 39 (suppl 1). https://www.mdsabstracts.org/abstract/dose-dependent-alterations-of-lysosomal-activity-and-alpha-synuclein-level-in-peripheral-blood-monocyte-derived-macrophages-and-sh-sy5y-neuroblastoma-cell-line-by-upon-inhibition-of-mtor-kinase-activi/. Accessed May 13, 2025.« Back to 2024 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/dose-dependent-alterations-of-lysosomal-activity-and-alpha-synuclein-level-in-peripheral-blood-monocyte-derived-macrophages-and-sh-sy5y-neuroblastoma-cell-line-by-upon-inhibition-of-mtor-kinase-activi/