Potential Binding Sites of Pharmacological Chaperone NCGC00241607 on Mutant ß-Glucocerebrosidase and Its Efficacy on Patient-Derived Cell Cultures in Gaucher and Parkinson's Disease.

Mutations in the GBA1 gene, encoding the lysosomal enzyme glucocerebrosidase (GCase), cause Gaucher disease (GD) and are the most common genetic risk factor for Parkinson's disease (PD). Pharmacological chaperones (PCs) are being developed as an alternative treatment approach for GD and PD. To date, NCGC00241607 (NCGC607) is one of the most promising PCs. Using molecular docking and molecular dynamics simulation we identified and characterized six allosteric binding sites on the GCase surface suitable for PCs. Two sites were energetically more preferable for NCGC607 and located nearby to the active site of the enzyme. We evaluated the effects of NCGC607 treatment on GCase activity and protein levels, glycolipids concentration in cultured macrophages from GD (n = 9) and GBA-PD (n = 5) patients as well as in induced human pluripotent stem cells (iPSC)-derived dopaminergic (DA) neurons from GBA-PD patient. The results showed that NCGC607 treatment increased GCase activity (by 1.3-fold) and protein levels (by 1.5-fold), decreased glycolipids concentration (by 4.0-fold) in cultured macrophages derived from GD patients and also enhanced GCase activity (by 1.5-fold) in cultured macrophages derived from GBA-PD patients with N370S mutation (p < 0.05). In iPSC-derived DA neurons from GBA-PD patients with N370S mutation NCGC607 treatment increased GCase activity and protein levels by 1.1-fold and 1.7-fold (p < 0.05). Thus, our results showed that NCGC607 could bind to allosteric sites on the GCase surface and confirmed its efficacy on cultured macrophages from GD and GBA-PD patients as well as on iPSC-derived DA neurons from GBA-PD patients.

Case of Early-Onset Parkinson's Disease in a Heterozygous Mutation Carrier of the ATP7B Gene.

In this paper, we report a clinically proven case of Parkinson's disease (PD) with early onset in a patient who is a heterozygous mutation carrier of ATP7B (the Wilson's disease gene). The patient was observed from 2011 to 2018 in the Center for Neurodegenerative Diseases, Institute of Experimental Medicine (St. Petersburg, Russia). During this period, the patient displayed aggravation of PD clinical symptoms that were accompanied by a decrease in the ceruloplasmin concentration (from 0.33 to 0.27 g/L) and an increase in serum nonceruloplasmin copper, which are typical of the late stages of Wilson's disease. It was found that one of the alleles of exon 14 in the ATP7B gene, which partially codes of the nucleotide-binding domain (N-domain), carries a mutation not previously reported corresponding to Cys1079Gly substitution. Alignment of the ATP7B N-domain amino acid sequences of representative vertebrate species has shown that the Cys at 1079 position is conserved throughout the evolution. Molecular dynamic analysis of a polypeptide with Cys1079Gly substitution showed that the mutation causes profound conformational changes in the N-domain, which could potentially lead to impairment of its functions. The role of ATP7B gene mutations in PD development is discussed.

Mutation analysis of Parkinson's disease genes in a Russian data set.

Common variants and risk factors related to familial and sporadic cases of Parkinson's disease (PD) in diverse populations have been identified at numerous genomic loci. In this study, genetic analysis was performed through a screening of LRRK2 G2019S, GBA mutations (L444P, N370S), and common variants (E326K, T369M) in 762 PD patients and in 400 controls. Next-generation sequencing analysis of 22 PD-related genes in 28 early-onset PD cases from North-Western region of Russia was performed. The frequency of LRRK2 G2019S mutation was 5.8% in familial and 0.5% in sporadic PD cases. The frequency of GBA mutations (L444P, N370S) in PD patients was higher compared to controls (odds ratio [OR] = 6.9, 95% confidence interval [CI], 0.9-53.13, p = 0.031), particularly in patients with early-onset compared to late-onset PD (OR = 3.90 [95% CI, 1.2-13.2], p = 0.009). The frequency of E326K and T369M was twice higher among PD patients than in controls (OR = 2.24, 95% CI 1.05-4.79, p = 0.033). However, the screening of 22 PD-related genes using our novel panel of gene resequencing in our series of 28 early-onset PD failed to identify any mutations. LRRK2 and GBA mutations were found to be common risk factors for PD in North-Western region of Russia.

A low blood copper concentration is a co-morbidity burden factor in Parkinson's disease development.

Parkinson's disease (PD) patients are often characterized by copper dyshomeostasis, which is responsible for ROS formation and fibrillogenesis. However, the relationships between copper metabolism and PD development are unclear. In this study in 50 patients with PD (pPD) and 50 age-matched healthy individuals, the serum total copper concentration, oxidase activity, ceruloplasmin and SOD3 protein concentrations were measured; and amount of copper atoms per ceruloplasmin molecule was calculated. These parameters were lower in pPD relatively to healthy volunteers. Decrease in concentrations of SOD3, ceruloplasmin, and copper but increase of interleukin-6 levels were associated with a risk of PD. Two consistent patterns were identified. First, a low serum copper concentration related with PD development and predominantly affected the non-motor symptoms of PD. There was no correlation between copper concentration and ceruloplasmin oxidase activity level (r = 0.27) in pPD. Second, Chelex 100 treatment revealed that pPD ceruloplasmin compared with ceruloplasmin of healthy individuals displayed smaller content of labile copper atoms. The presence or absence of these atoms had no effect on ceruloplasmin enzymatic activities. Our findings suggest that cuproenzyme deficiency, which is typical for PD, can be caused by violation of metabolic incorporation of the labile copper atoms into ceruloplasmin molecule.