Biomarkers for Lewy body diseases and other alpha-synucleinopathies in biofluids: current evidence and future directions Alice Russotto, Antonio Longobardi, Arianna Ciullini, Federico Angelo Cazzaniga, Merve Begüm Bacınoğlu, Barbara Borroni, Roberta Ghidoni, Fabio Moda, Claudia Saraceno Journal of Translational Medicine, 2026 Synucleinopathies, including Parkinson’s disease (PD), dementia with Lewy bodies (DLB), and multiple system atrophy (MSA), are a group of proteinopathies characterized by neuronal and glial aggregated alpha-synuclein (α-syn) inclusions. Pathologically, these disorders are typically classified into two categories based on the distribution of α-syn: Lewy body diseases (LBDs), such as PD and DLB, which are characterized by α-syn aggregates in neuronal perikarya and neurites in the form of Lewy bodies (LBs) and Lewy neurites (LNs), and MSA, which shows α-syn aggregates in oligodendrocytes as glial cytoplasmic inclusions (GCIs). The clinical distinction between these disorders is challenging, especially in the early stages, due to the overlap of symptoms. This highlights the urgent need for reliable biomarkers to enable more accurate diagnosis and to guide the development of targeted therapeutic strategies. Current research focuses on α-syn which is recognized as a key protein in the pathology of PD, although its potential as a biomarker remains debated due to inconsistent findings. This review provides an overview of recent advancements in biomarkers research for synucleinopathies, focusing on α-syn, neurofilament light chain (NfL), tau, synapsin III (SynIII), and extracellular vesicles (EVs). These biomarkers have been identified in various biofluids and non-invasive sources, including cerebrospinal fluid (CSF), blood, olfactory mucosa (OM), and urine, suggesting promising avenues for the development of future diagnostic tools. α-syn SAAs provide high sensitivity and specificity for distinguishing LBDs from other neurodegenerative disorders. α-syn, tau, and NfL correlate with clinical features, disease severity, and progression. SynIII shows potential as a biomarker for synucleinopathies due to its interaction with α-syn and its accumulation in affected brain regions. Biomarkers panel combining α-syn, NfL, tau, SynIII, and EVs offer improved diagnostic accuracy over single markers. Urine and OM are promising new non-invasive and potential sources for biomarkers.
Up-regulation of tRNA-derived miR-1274b in tears of Parkinson's disease patients Erika Salvi, Ilaria Vannetiello, Federico Angelo Cazzaniga, Arianna Ciullini, Antonia F. Demleitner, Nico Golfré Andreasi, Simone Tomé, Antonio Emanuele Elia, Valentina Leta, Paul Lingor, Roberto Eleopra, Marcella Catania, Grazia Devigili, Fabio Moda Parkinsonism and Related Disorders, 2026
Peptidomimetics Inspired by α-Synuclein or Its Chaperone αB-Crystallin Differentially Modulate α-Synuclein Aggregation Nicolo Bisi, Josine Kothuis, Julia Kaffy, Helena Pérez Peña, Celina Schulz, Chiara Maria Giulia De Luca, Arianna Ciullini, Ilaria Linda Dellarole, Léa Radal, Fabio Moda, Graziella Cappelletti, Dragos Horvath, Stefano Pieraccini, Wolfgang Hoyer, Frédéric Halgand, Nicolo Tonali, Sandrine Ongeri Journal of Medicinal Chemistry, 2026 Aggregation of the α-Synuclein (αSyn) protein in neurons is responsible for synucleinopathies such as Parkinson’s disease. In healthy cells, αSyn is primarily present as monomers. Under pathological conditions, oligomers and fibrils are formed, leading to neuronal toxicity and death. No treatment prevents fatal synucleinopathies. We designed small peptidomimetics based on the structure of αSyn aggregates and on its chaperone protein αB-Crystallin. Interestingly, a relationship between the impact of peptidomimetics on the αSyn aggregation process, their sequences, and secondary conformation has been evidenced. In vitro and in cellular assays demonstrated that one compound based on αB-Crystallin was able to interfere with αSyn folding and aggregation by reducing the formation of oligomers and promoting off-pathway aggregation. The demonstration that physiological chaperone proteins can be mimicked by small peptide derivatives paves the way for new strategies to design inhibitors of amyloid protein aggregation, a hallmark of around 50 neurodegenerative and systemic amyloid diseases.
Diagnostic Performance of the α-Synuclein Seed Amplification Assay for Dementia With Lewy Bodies Rakesh Kumar, Stephanie Gravett, Vesna Jelic, Johannes Lange, Linn Oftedal, Arianna Ciullini, Merve Begüm Bacınoğlu, Chiara Maria Giulia De Luca, Lola Hamied, Catherine Birck, Frederic Blanc, Patty L. Hoede, Afina W. Lemstra, Maria Camila Gonzalez, Dag Aarsland, Charlotte E. Teunissen, Olivier Bousiges, Fabio Moda, Jodi Maple-Grødem, Axel Abelein, Daniel Ferreira Neurology, 2026 BACKGROUND AND OBJECTIVES: The α-synuclein (α-syn) seed amplification assay (SAA) has shown promising results for diagnosing dementia with Lewy bodies (DLB) using CSF samples. A barrier to implementing α-syn SAA clinically is the use of different protocols for the assay. It is unknown how different protocols perform in comparison with each other. We compared the performance of α-syn SAA across 4 laboratories using CSF samples of patients with DLB. METHODS: This was a retrospective cross-sectional study that included data from 4 different European laboratories. We included probable patients with DLB with a positive dopamine transporter (DaT)-SCAN and known amyloid-β status who had mild-to-moderate dementia, along with age-matched and sex-matched controls. The α-syn SAA was run across 4 laboratories using different protocols varying α-syn concentration and plate reader settings. CSF samples were provided by a fifth independent laboratory, which also performed statistical and result analyses. RESULTS: We included 20 patients with DLB (mean age 67 ± 6 years, 60% male) and 10 controls (mean age 67 ± 2 years, 70% male). Neuropathologic confirmation was available for 2 patients with DLB. On average, the 4 laboratories achieved 78.8% sensitivity (minimum 55%, maximum 100%), 77.5% specificity (minimum 60%, maximum 100%), and 78.5% accuracy (minimum 57%, maximum 100%) for discriminating DLB from controls, but our findings show that diagnostic performance of SAA varied across laboratories: Lab A achieved 100% sensitivity (CI 84%-100%) and 100% specificity (CI 72%-100%); Lab B achieved 85% sensitivity (CI 64%-95%) and 90% specificity (CI 59%-99%); Lab C achieved 55% sensitivity (CI 34%-74%) and 60% specificity (CI 31%-83%); and Lab D achieved 75% sensitivity (CI 53%-89%) and 60% specificity (CI 31%-83%). In general, SAA results showed numerically lower sensitivity in β-amyloid (Aβ)-positive patients with DLB (70%) compared with Aβ-negative patients with DLB (87.5%) (nonstatistically significant). A fair agreement of SAA results was obtained across the 4 laboratories (average κ = 0.246). DISCUSSION: This study highlights challenges for the reproducibility of α-syn SAA results across different protocols applied by different laboratories. This finding, together with the methodological variability reported across laboratories, may challenge the clinical implementation of the α-syn SAA. This study provides relevant support for initiating harmonization and standardization of SAA protocols to move the field toward the clinical implementation of SAAs for the biomarker-based diagnosis of DLB. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence of variations in the accuracy of CSF α-syn SAA across 4 separate laboratories in distinguishing patients with DLB from healthy controls.
TDP-43 seeding activity in the olfactory mucosa of patients with amyotrophic lateral sclerosis Maria Vizziello, Ilaria Linda Dellarole, Arianna Ciullini, Riccardo Pascuzzo, Annalisa Lombardo, Floriana Bellandi, Luigi Celauro, Claudia Battipaglia, Emilio Ciusani, Ambra Rizzo, Marcella Catania, Grazia Devigili, Sara Adriana Della Seta, Valentina Margiotta, Monica Consonni, Veronica Faltracco, Pietro Tiraboschi, Nilo Riva, Sara Maria Silvia Portaleone, Gianluigi Zanusso, Giuseppe Legname, Giuseppe Lauria, Eleonora Dalla Bella, Fabio Moda Molecular Neurodegeneration, 2025 Background In recent years, the seed amplification assay (SAA) has enabled the identification of pathological TDP-43 in the cerebrospinal fluid (CSF) and olfactory mucosa (OM) of patients with genetic forms of frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS). Here, we investigated the seeding activity of TDP-43 in OM samples collected from patients with sporadic ALS. Methods OM samples were collected from patients with (a) sporadic motor neuron diseases (MND), including spinal ALS (n = 35), bulbar ALS (n = 18), primary lateral sclerosis (n = 10), and facial onset sensory and motor neuronopathy (n = 2); (b) genetic MND, including carriers of C9orf72 exp (n = 6), TARDBP (n = 4), SQSTM1 (n = 3), C9orf72 exp + SQSTM1 (n = 1), OPTN (n = 1), GLE1 (n = 1), FUS (n = 1) and SOD1 (n = 4) mutations; (c) other neurodegenerative disorders (OND), including Alzheimer’s disease (n = 3), dementia with Lewy bodies (n = 8) and multiple system atrophy (n = 6); and (d) control subjects (n = 22). All samples were subjected to SAA analysis for TDP-43 (TDP-43_SAA). Plasmatic levels of TDP-43 and neurofilament-light chain (NfL) were also assessed in a selected number of patients. Results TDP-43_SAA was positive in 29/65 patients with sporadic MND, 9/21 patients with genetic MND, 6/17 OND patients and 3/22 controls. Surprisingly, one presymptomatic individual also tested positive. As expected, OM of genetic non-TDP-43-related MND tested negative. Interestingly, fluorescence values from non-MND samples that tested positive were consistently and significantly lower than those obtained with sporadic and genetic MND. Furthermore, among TDP-43-positive samples, the lag phase observed in MND patients was significantly longer than that in non-MND patients. Plasma TDP-43 levels were significantly higher in sporadic MND patients compared to controls and decreased as the disease progressed. Similarly, plasma NfL levels were higher in both sporadic and genetic MND patients and positively correlated with disease progression rate (ΔFS). No significant correlations were detected between TDP-43_SAA findings and the biological, clinical, or neuropsychological parameters considered. Conclusions The OM of a subset of patients with sporadic MND can trigger seeding activity for TDP-43, as previously observed in genetic MND. Thus, TDP-43_SAA analysis of OM can improve the clinical characterization of ALS across different phenotypes and enhance our understanding of these diseases. Finally, plasma TDP-43 could serve as a potential biomarker for monitoring disease progression. However, further research is needed to confirm and expand these findings.
Substitution of histidine 95 by tyrosine in the prion protein causes spontaneous neurodegeneration in transgenic mice Juan-María Torres, Alba Marín-Moreno, Juan-Carlos Espinosa, Sara Canoyra, Anna Burato, Arianna Ciullini, Chiara Maria Giulia De Luca, Edoardo Bistaffa, Fabio Moda, Giuseppe Legname Plos Pathogens, 2025 Prion diseases are neurodegenerative disorders caused by a change in conformation of the prion protein from the cellular form (PrPC) to a misfolded isoform (PrPSc). PrPC is a copper binding protein via histidine residues in the octapeptide repeats (OR) and the non-OR region located at the N-terminus. Although the functional implication of copper binding to PrPC is still under investigation, copper may play a role in prion disease. In this study, we describe transgenic mice expressing mouse prion protein replacing histidine 95 by tyrosine (PrP H95Y) to disrupt the non-OR copper-binding site. Transgenic mice overexpressing PrP H95Y showed clinical signs and died at about 100 days with spongiform degeneration and PK-resistant PrP. Inoculation of brain homogenate from mice overexpressing PrP H95Y to Tga20 mice expressing wild-type PrP also causes lethal, spongiform encephalopathy. We conclude that this substitution could promote PrPC-PrPSc conversion and induce spontaneous prion disease in vivo.
α-Synuclein distribution in olfactory mucosa and skin nerves in Parkinson disease associated with an EIF4G1 gene mutation Arianna Braccia, Antonio Emanuele Elia, Grazia Devigili, Raffaella Lombardi, Alessia Luppino, Samanta Mazzetti, Celeste Panteghini, Isabel Colangelo, Marta Suerz, Sara Maria Portaleone, Anna Maria Perilli, Chiara Maria Giulia De Luca, Arianna Ciullini, Ilaria Linda Dellarole, Roberta Telese, Barbara Garavaglia, Fabio Moda, Roberto Eleopra Journal of Neuropathology and Experimental Neurology, 2025 The EIF4G1 gene has been considered an autosomal dominant cause of Parkinson disease (PD), even if its role is still debated. The objective of this study was to describe the phenotype and α-synuclein distribution in peripheral tissues in 2 related PD patients (mother and daughter), who are carriers of the same variant in exon 10 of EIF4G1 (c.1216G>A, p.Gly406Arg). We used the Burghart Sniffin Sticks test for olfactory function. α-Synuclein distribution in the olfactory mucosa and skin samples was analyzed using RT-QuIC, double immunofluorescence, and immunohistochemical staining. Both patients presented with a mild motor syndrome associated with hyposmia as prominent traits; pathological α-synuclein deposits were found in the olfactory mucosa but not in the skin. The phenotype and the findings in peripheral tissues suggest that PARK18 could manifest as a “benign” form of PD associated with hyposmia, with a slow progression and sparse α-synuclein accumulation in the peripheral nervous system.
From Protein Misfolding to Dementia: Basic Research, Innovative Diagnosis and Early Biomarkers Merve Begüm Bacınoğlu, Arianna Ciullini, Giorgio Giaccone, Fabio Moda Frontiers in Bioscience Landmark, 2024 IMR Press is a leading publisher of open access peer-reviewed biomedical and life sciences journals. We aim to facilitate the dissemination of high-quality research in the area of biomedical science. With a long tradition and wide readership, IMR Press is dedicated to making positive contributions to academics, corporate libraries as well as to readers and authors. All the editors in IMR Press will provide the best service for researchers, allowing them to have a easy and smooth publication experience and helping maximize the impact and visibility of their research.
