LRRK2 Inhibition Differently Affects Lysosomal Hydrolase Activity and Autophagy-Related Protein Levels in PBMC-Derived Macrophages from Patients with Different Synucleinopathies

Katerina Basharova^1,2,#,*, Anastasia Bezrukova^1,2,#, Alena Kopytova^1,2, Anna Lavrinova^1,2, Galina Baydakova³, Irina Miliukhina^1,4, Ekaterina Zakharova^1,3, Anton Emelyanov^1,2, Sofya Pchelina^1,2, Tatiana Usenko^1,2,*
1 Petersburg Nuclear Physics Institute Named by B.P. Konstantinov of National Research Centre «Kurchatov Institute», Gatchina, Russia
2 Department of Molecular Genetic and Nanobiological Technologies, Pavlov First Saint Petersburg State Medical University, St. Petersburg, Russia
3 Research Center for Medical Genetics, Moscow, Russia
4 N.P. Bechtereva Institute of the Human Brain of Russian Academy of Sciences, St. Petersburg, Russia
* Corresponding Author: Katerina Basharova. Email: email ; Tatiana Usenko. Email: email
# These authors contributed equally to this work
(This article belongs to the Special Issue: Cellular and Molecular Mechanisms in Parkinson's Disease: Novel Targets and Biomarkers for Target Therapy)

BIOCELL https://doi.org/10.32604/biocell.2026.079585

Received 24 January 2026; Accepted 21 May 2026; Published online 05 June 2026

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Abstract

Objectives: Synucleinopathies—Parkinson’s disease (PD), dementia with Lewy bodies (DLB), and multiple system atrophy (MSA)—involve alpha-synuclein aggregation and lysosomal dysfunction. We conducted a longitudinal study of lysosomal hydrolase activities and lysosphingolipid levels in blood and PBMC-derived macrophages from patients, and assessed the effects of LRRK2 inhibition (MLi-2). Methods: Blood and PBMC-derived macrophages were collected from patients with idiopathic PD (iPD), DLB, MSA, and controls. Enzyme activities (GCase, ASMase, GLA, GALC) and lysosphingolipids (HexSph, LysoGb3, LysoSM) were measured. Autophagy markers (p62, LC3B-II) and cathepsin D (CTSD) were analyzed by western blot. Effects of MLi-2 were evaluated in macrophages. Results: All synucleinopathy groups showed reduced blood GCase activity and elevated HexSph levels, with the highest HexSph levels observed in MSA (p < 0.05). DLB exhibited reduced ASMase, whereas MSA showed broader sphingolipid disruption (reduced ASMase activity, increased GLA and GALC activities, elevated LysoGb3 levels (p < 0.05)). In iPD, LysoGb3 levels increased, and LysoSM levels decreased. In PBMC-derived macrophages, MSA showed reduced GCase, GALC, and ASMase activities. HexSph levels were elevated in all groups, while LysoGb3 levels were increased in iPD and MSA (p < 0.05). DLB macrophages showed increased mature CTSD, whereas MSA cells exhibited reduced CTSD and p62 (p < 0.05). MLi-2 had minimal effects on enzyme activities and lipid levels. It increased p62 in iPD, reduced CTSD in DLB (p < 0.05), and had no effect in MSA (p > 0.05). Conclusion: HexSph may represent a common marker of synucleinopathies, while MSA demonstrates the most pronounced lysosomal dysfunction. Limited effects of LRRK2 inhibition suggest a minor role for this pathway in sporadic synucleinopathies.