Sulev Koks

Mesoporous silica nanoparticles (MSNPs) have great potential for delivering both small‐molecule drugs and large therapeutic agents. PEI (polyethylenimine) coating enhances the drug delivery efficiency, stability, and functionalization capacity of MSNPs. However, coating MSNPs with PEI is generally performed in DMF, a solvent that is highly detrimental to therapeutic agents, including biologics and pharmaceuticals. Consequently, PEI coating after mRNA loading is most often achieved through physical adsorption, or alternatively, mRNA is attached to the surface of nanoparticles (NPs) following covalent PEI coating. In this study, we investigated the covalent attachment of PEI to MSNPs using solvents and conditions that are more compatible with sensitive molecules, such as DNA and RNA. This approach enabled the covalent attachment of PEI to MSNPs loaded with sensitive molecules. The results obtained with alternative solvents were compared with those obtained with DMF as a reference solvent. Our findings demonstrated that covalent PEI attachment in a chloroform:MeCN (20:80) mixture was more efficient than in DMF. Subsequently, mRNA‐loaded MSNPs were covalently coated with PEI using this solvent mixture, and the protective effect of the PEI coating on the loaded mRNA was evaluated. The PEI‐coated MSNPs offered enhanced protection for mRNA against RNase A compared to uncoated MSNPs.

Background: Lipid metabolism is increasingly implicated in Parkinson's Disease (PD) pathology, yet the specific lipid classes and acyl chain compositions involved, and their relationship with PD clinical symptoms, remain poorly characterised.

Objectives: We aimed to identify serum lipid signatures that differentiate people with PD (PwPD) from healthy controls and to evaluate associations with levodopa-induced dyskinesia (LID).

Methods: Serum collected from 58 PwPD and 58 age- and sex-matched non-PD controls was analysed using targeted liquid chromatography - mass spectrometry (LC-MS). Group differences were assessed using univariate and multivariate approaches. Logistic regression was used to identify lipids associated with LID among PwPD.

Results: Significantly lower levels of glycerolipids and glycerophospholipids were observed in PwPD compared to controls, alongside higher levels of lysophosphatidylethanolamines (LPE) and lysophosphatidylcholines (LPC). Analysis of individual lipid species revealed a lipid remodelling of the acyl chain composition of glycerolipids and glycerophospholipids, with decreased esterified arachidonic, adrenic, docosapentaenoic, and docosahexaenoic acids. Non-esterified arachidonic acid (p = 5.80e-6) and eicosapentaenoic acid (p = 3.65e-10) were elevated in PwPD. In secondary analyses, no lipids discriminated between PwPD with and without LID; however, these models were constrained by modest subgroup sizes and clinical heterogeneity between groups, limiting conclusions regarding lipid-based discrimination of LID status.

Conclusions: These findings demonstrate disease-associated remodelling of acyl chain composition across multiple lipid classes in PD, particularly selective depletion of esterified polyunsaturated fatty acids from glycerolipids and glycerophospholipids. Replication in independent cohorts is warranted to establish whether these pathways represent viable therapeutic targets.

Bruck syndrome type 2 (BRKS2) is a rare disorder marked by congenital joint contractures and bone fragility, caused by variants in PLOD2, which encodes lysyl hydroxylase 2 essential for collagen stability. We report the first genetically confirmed BRKS2 cases from Indonesia and Ukraine, both showing fractures, skeletal deformities, and contractures. The Indonesian patient had compound heterozygous variants, while the Ukrainian patient had a homozygous missense variant, expanding the phenotypic and geographic spectrum of the disorder.

Parkinson’s disease (PD) is a complex neurodegenerative disorder with diverse molecular signatures that extend beyond the central nervous system. Peripheral blood serves as a minimally invasive source of transcriptomic biomarkers reflecting systemic inflammation, mitochondrial dysfunction, lysosomal impairment, and disrupted RNA processing—key pathways involved in PD. Long-read RNA sequencing with Oxford Nanopore Technologies (ONT) offers unprecedented detail of full-length transcripts, alternative isoforms, and RNA modifications, enabling more accurate detection of disease-related transcriptional changes. We conducted high-throughput ONT long-read RNA sequencing on blood samples from 145 individuals, including PD patients and age-matched healthy controls. RNA libraries were prepared using a cDNA-based protocol optimised for high-accuracy PromethION sequencing. Transcriptomes were quantified with ONT-specific pipelines, and analyses of differential gene expression (DGE), differential transcript expression (DEX), differential transcript usage (DTU), and alternative splicing were performed using ONT-aware tools such as DRIMSeq, DEXSeq, and stageR. Pathway enrichment linked disease-related changes to mitochondrial, lysosomal, and vesicle-trafficking pathways. Our analysis identified highly significant PD-associated transcriptional signatures in peripheral blood (SNCA, VPS13C, LRRK2, GRN, STAU1, NPTN, PARK7). Long-read sequencing uncovered extensive isoform-level dysregulation, including novel transcript variants (e.g., BCL2L2-PABPN1, SQSTM1) in pathways relevant to PD, such as autophagy and endolysosomal trafficking. DTU analyses revealed shifts in isoforms of LRRK2 and GBA1, indicating widespread disturbances in RNA processing. Enrichment analysis showed activation of molecular pathways linked to neurodegeneration. This study provides the largest long-read blood transcriptomic dataset in PD to date, demonstrating that ONT sequencing can resolve isoform-level changes and reveal systemic molecular signatures of PD. Our findings support the development of blood-based RNA biomarkers and the establishment of long-read transcriptomics as a transformative approach for genomic pathology in PD.

Introduction
GCH1 has been implicated in Parkinson’s disease (PD), but its risks variants and associations are not well defined.

Objectives
To investigate the clinical relevance and PD risk associated with the GCH1 p.Ser80Asn variant.

Methods
We first identified a segregating GCH1 p.Ser80Asn variant in a Malaysian Chinese PD family via whole genome sequencing (WGS). We assessed its risk association using multi-ancestry WGS data from the Global Parkinson’s Genetics Program (GP2) (n=22,372PD vs n=8,826Controls) and meta-analysis of East Asian (EAS) cohorts (n=4,712PD vs 38,733Controls). Clinico-demographic details of affected variant carriers were collated.

Results
The GCH1 p.Ser80Asn variant was enriched in GP2 EAS PD populations (n=9/2,757; 0.33%) but not detected in other ancestries. Meta-analysis revealed increased PD risk in EAS populations (odds ratio:5.1; 95%CI:2.3–10.7; p=2.89×10−5). Affected carriers (mean age at onset:56.3±12.5 years) had additional occurrence of dystonia, while dementia was rare.

Conclusions
The GCH1 p.Ser80Asn variant is a rare, EAS-enriched risk variant for PD.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder characterised by progressive muscle weakness in both bulbar and extremity muscles, leading to a diverse clinical phenotype with motor and non-motor symptoms. Approximately 85% of ALS cases are sporadic (sALS), while the remaining 10%-15% are familial (fALS). Biological biomarkers of sporadic ALS remain poorly understood, hindering precise patient screening, delaying diagnosis and negatively affecting prognosis. This study aims to identify potential proteomic biomarkers by comparing the cerebrospinal fluid (CSF) of sALS patients with that of patients suffering from other neurological diseases. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used for proteomic profiling of CSF samples from 24 sALS patients and 26 patients with other neurological diseases. The complete protein expression profiles were compared using a two-tailed Student's t-test, with a p < 0.05 considered statistically significant with additional FDR correction at the 0.1 level. Proteomic analysis of CSF samples identified significant quantitative changes in 96 proteins with threshold p < 0.05 and 74 proteins with FDR < 0.1 between sALS and non-ALS patients, including alterations in proteins associated with neurodegenerative processes, such as amyloid precursor proteins and inflammatory markers. CSF proteomic analysis reveals altered inflammatory and neurodegenerative metabolic pathways, providing valuable insights into the proteomic landscape of sALS. Several dysregulated proteins were consistent with the disease mechanisms highlighted in previous studies. These findings represent a step forward in developing personalised approaches for diagnosing and managing the disease.

To investigate whether antidiabetic drugs have a biological basis to be repurposed in PD prevention, we applied a drug target Mendelian randomization framework to assess associations between genetic variation in antidiabetic drug targets and PD risk or age at onset (AAO). Instrumental variables (IVs) were derived from GWAS summary statistics on fasting glucose (FG), glycated hemoglobin (HbA1c), and gene expression data from GTEx. Apart from SGLT2 inhibitors, all other antidiabetic drugs of interest could be instrumented through our methods. Positive and negative control analyses were carried out to validate 20 IVs in the FG arm and 23 IVs in the HbA1c arm. DPP-4 inhibitors failed the positive control. GWAS summary statistics for PD risk and AAO data were sourced from the IPDGC and COURAGE-PD consortia, resulting in 42 083 cases/457 090 controls for risk and 37 103 PD cases for AAO. MR analyses showed no significant associations across consortia or in meta-analysis. These findings do not support a causal role of genetic variation in antidiabetic drug targets in PD risk or AAO.

Background/Objectives: Parkinson’s disease (PD) is associated with systemic molecular alterations that extend beyond the central nervous system, including changes in peripheral blood transcriptomic profiles. While prior studies have focused predominantly on coding-gene expression, the longitudinal behavior of the peripheral blood repeatome following clinical diagnosis remains poorly characterized. Here, we investigated temporal remodeling of repetitive-element transcription over 36 months post-diagnosis by integrating repeat subfamily- and locus-specific analyses. Methods: Repeatome expression was quantified using SalmonTE and DESeq2 in peripheral blood RNA-seq data from 1560 PD and control individuals at diagnostic baseline (BL) and four follow-up visits (6, 12, 24, and 36 months). Differential expression was assessed at the subfamily level, with additional locus-specific validation in a representative subset. Results: A total of 259 repeat subfamilies were differentially expressed (padj < 0.05), of which 224 (86.5%) were already detected at baseline. Enrichment of differential expression was significantly higher at baseline than at later visits (odds ratio = 30.9, p < 2.2 × 10−16), with limited additional divergence over time. Longitudinal analyses revealed non-linear trajectories in selected repeat families, including Alu and SVA subfamilies. Locus-specific analysis identified 237 significantly regulated elements, demonstrating heterogeneous, site-specific transcriptional changes, including clusters of differentially expressed loci and instances within PD-relevant genomic regions (e.g., SNCA and IKZF2). Conclusions: Peripheral blood repeatome expression differs between PD and control groups, with the dominant signal established at clinical diagnosis and modest longitudinal modulation thereafter. Integration of locus-level analysis indicates that subfamily level patterns arise from discrete genomic events rather than uniform regulation. These findings support a model of systemic, immune-associated transcriptomic remodeling in circulating blood cells and position the peripheral repeatome as a dynamic framework for biomarker discovery and future mechanistic investigation.

Progression from Parkinson's disease (PD) to Lewy body dementia is a major clinical concern. Although several progression-associated loci have been identified, their cumulative effects on cognitive decline have not been systematically evaluated. To assess the dose-dependent effect of five candidate progression loci linked to synaptic vulnerability (RIMS2, TMEM108, GBA1) and amyloid-tau pathology (APOE, WWOX), we analyzed 7745 participants from 24 cohorts with 28,737 longitudinal visits over 15 years using random-effects meta-analyses of cohort-specific Cox proportional hazards models. Dementia risk increased monotonically with the number of progression loci (0, 1, 2, or ≥3). A single locus conferred a 1.56-fold increase in risk (hazard ratio (HR) = 1.56, 95% CI: 1.28-1.89), rising to 3.21-fold for two loci (HR = 3.21, 95% CI: 2.19-4.70) and 7.49-fold for three or more loci (HR = 7.49, 95% CI: 4.98-11.28). Individually, GBA1 (HR = 2.09), APOE ε4 (HR = 1.71), RIMS2 (HR = 1.90), TMEM108 (HR = 2.05), and WWOX (HR = 1.56) were associated with dementia risk, but there was heterogeneity between clinical trials, biomarkers, and population-based cohorts. Multi-locus dosage increases dementia risk in a monotonic manner and may improve stratification and clinical trial design in PD.