Synaptic and Cytoskeletal CSF Signatures of Motor Neuron Disease: The Role of Cyclase-Associated Protein 2

Synaptic and Cytoskeletal CSF Signatures of Motor Neuron Disease: The Role of Cyclase-Associated Protein 2 | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Synaptic and Cytoskeletal CSF Signatures of Motor Neuron Disease: The Role of Cyclase-Associated Protein 2 Andrea Pilotto, Silvia Pelucchi, Chiara Trasciatti, Lucia Ferullo, and 11 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7933370/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 16 Feb, 2026 Read the published version in Scientific Reports → Version 1 posted 11 You are reading this latest preprint version Abstract Cyclase-associated protein 2 (CAP2), is a synaptic actin-binding protein involved in cofilin-mediated spine remodelling, Alzheimer's Disease synaptic failure and myofibril maintenance, indicating its potential involvement in MND. This study examined CSF levels of CAP2 in 60 patients with motor neuron disease (MND) and 40 healthy controls (HC) to assess its diagnostic and prognostic value and its relationship with neuronal, glial and synaptic markers. Glial fibrillary acidic protein (GFAP), neurofilament light chain (NfL), phosphorylated and total tau (p-Tau 181, t-Tau), CAP2 and synaptosomal-associated protein 25 (SNAP-25) were quantified using ELISA, Lumipulse and SIMOA platforms. MND patients displayed increased GFAP, NfL, t-Tau, p-Tau 181 levels and CAP2 while SNAP-25 was reduced. CAP2 correlated with tau markers, but not with NfL or GFAP. Unlike NfL, which was higher in upper motor neuron–predominant cases and predicted faster progression and poorer survival, CAP2 did not vary with disease subtypes or severity. The study showed that CAP2 is associated with MND independently from neuronal, glial and presynaptic dysfunction. Integrating CAP2 into multi-marker panels could enhance understanding of synaptic pathology in MND. Health sciences/Neurology Biological sciences/Neuroscience motor neuron disease (MND) synaptic biomarkers neurofilament light chain (NfL) cerebrospinal fluid (CSF) Figures Figure 1 Figure 2 INTRODUCTION Synaptic dysfunction is increasingly recognized as a critical early event in the pathogenesis of neurodegenerative diseases [ 1 ]. Long before neuronal death becomes evident, synaptic alterations disrupt communication within neural circuits, contributing to neurological impairments. These insights have spurred extensive efforts to identify cerebrospinal fluid (CSF) biomarkers reflecting synaptic integrity, including neurogranin, GAP43, SNAP-25, and PSD-95 [ 2 , 3 ]. Synaptic pathology in motor neuron diseases (MND) has been less investigated [ 4 , 5 ]. Nevertheless, a growing body of research highlights that synaptic degeneration is a prominent and early feature of MND. Human and animal studies consistently show a loss of presynaptic proteins such as synaptophysin, SNAP-25, and syntaxin in the spinal cord and neuromuscular junction [ 6 ]. Changes in excitatory and inhibitory neurotransmission, including imbalances in glutamate and GABA receptor subunits, and the synaptic mislocalization of proteins such as FUS and TDP-43, further underscore the role of synaptic alterations in disease progression [ 5 ]. Despite these findings, few fluid biomarkers have been established to reflect neuronal and synaptic pathology in MND. Most studies to date have focused on axonal damage markers such as neurofilament light chain (NfL) and phosphorylated neurofilament heavy chain (pNfH), which consistently demonstrate high sensitivity and prognostic value [ 7 , 8 ]. Synaptic proteins in cerebrospinal fluid (CSF), including SNAP-25 and neurogranin appeared to be less studied in MND, with still discussed findings [ 9 , 10 ]. Nevertheless, the recent evidence that the neuronal pentraxins might represent a valid readout for therapy responsiveness in ALS [ 11 ] increased the potential clinical relevance of synaptic biomarkers in MND. In this context, cyclase-associated protein 2 (CAP2) fits within the framework of synaptic markers. CAP2 belongs to the CAP protein family, actin-binding proteins that regulate actin dynamics. While the isoform CAP1 is widely expressed, CAP2 expression is restricted to a few organs, including the brain and skeletal muscles [ 12 , 13 ]. In skeletal muscle, CAP2 emerges as a critical regulator of skeletal muscle development and function, primarily through its role in actin cytoskeleton dynamics and myofibril differentiation [ 14 ]. In neurons, CAP2 is a postsynaptic protein that modulates dendritic spine morphology and facilitates cofilin 1-mediated spine remodeling during synaptic plasticity events [ 15 ]. Given the mounting evidence of early synaptic involvement in MND and the functional importance of CAP2 in synaptic and myofibril function, we measured CSF CAP2 concentration in patients with MND compared to healthy controls and explore its relationship with CSF markers such as phospho-Tau total Tau, NfL and GFAP. Furthermore, the association with clinical subtypes of the disease and the prognostic value of CAP2 levels was assessed longitudinally in the MND cohort. METHODS Study population Patients with Gold Coast criteria [ 16 ] for motor neuron disease (MND) diagnosis were consecutively enrolled at the outpatient Neuromuscular Clinic at Brescia University Hospital. Individuals were included according to the following exclusion criteria: (1) age < 55 years; (2) dementia or significant cognitive changes reported; (3) abnormal cognitive screening according to Montreal Cognitive Assessment (MoCA < 26); (4) medical conditions potentially associated with cognitive deficits or movement/gait alterations; (5) major psychiatric disorders (6) recent acute fever/inflammation/concussion. For each subject, the following data were collected: (1) demographic details and clinical characteristics, including the region of symptom onset; (2) presence of upper motor neuron (UMN) signs (e.g., hyperreflexia, spasticity, and pseudobulbar features) and lower motor neuron (LMN) signs (e.g. muscle wasting, fasciculations, and hyporeflexia). Clinical assessment At baseline, all suspected motor neuron disease patients underwent a comprehensive clinical and diagnostic work-up including CSF. All patients underwent brain and spinal cord MRI, electromyography and motor/sensory evoked potential, as well as biochemical screening, according to current standard of care and MND diagnosis [ 17 ]. Assessment of UMN and LMN was defined by neurological examination and supported by electrodiagnostic studies [ 16 ]. The Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R) was used to assess disease severity [ 18 ]. DPR was defined as (48-ALSFRS-R)/disease duration (points per month) and calculated at first visit, as well as 12 months follow-up [ 19 ]. For biomarker comparison, an age-matched group of controls who underwent CSF analyses for isolated persistent headache, but any other neurological symptom or MRI/EEG/CSF alteration, was included and considered as negative controls, as previously described [ 20 ]. The study was approved by the local ethics committee (NP 1471, DMA, Brescia) and was performed in conformity with the Helsinki Declaration; informed consent was obtained from each study participant or their legally authorized representative. CSF collection and analysis CSF collection was performed in fasting condition according to the standardized protocol of the outpatient clinic, from 09:00 to 11:00 in the morning, after clinical informed written consent was obtained. CSF was collected in sterile polypropylene tubes and gently mixed to avoid gradient effects. CSF was centrifugated and firstly processed for standard biochemical analyses, whereas two milliliters of CSF were stored in cryotubes at − 80°C before biomarkers testing. As by the guidelines delivered by the Consensus of the Task Force on Biological Markers in Psychiatry of the World Federation of Societies of Biological Psychiatry, CSF samples were subjected to a maximum of two freeze-thaw cycles [ 21 ]. Only patients with normal routine measures were included in further analyses. CSF neuronal, glial and synaptic markers CSF p-Tau181, and total tau were measured using the Lumipulse G assays (Fujirebio) on the LUMIPULSE G600II for diagnostic standard analyses performed at Central Chemical Analysis Laboratory, as previously reported [ 22 ]. All CSF samples were additionally analyzed for neuronal (neurofilament light chain, NfL), glial (glial fibrillary acidic protein, GFAP) and synaptic markers, namely SNAP-25 and CAP2. CSF SIMOA analyses were conducted by researchers who were blind to the origin of plasma biomarkers, at the Laboratory of Advanced Biological Markers at the University of Brescia, utilizing the SR-X platform and the Neurology 2-Plex Advantage Kits (NfL/GFAP) and SNAP-25 kit (single-plex) from Quanterix, Billerica, MA. CAP2 was measured using enzyme-linked immunosorbent assays (ELISA) performed at the Department of Pharmacological and Biomolecular Sciences (University of Milan), as previously reported [ 23 ]. Briefly, the CSF samples were diluted at 1:20, and their CAP2 concentration was determined using a commercially available ELISA (catalog number IK5163; Immunological Sciences, Rome, Italy). This assay has high sensitivity and specificity for CAP2 detection; no significant cross-reactivity or interference between CAP2 and its analogs was observed. The mean of duplicate assessment was used for final analysis. Statistical analyses Continuous variables are reported as median (interquartile range), and categorical variables are reported as numbers and percentages (n, %). The normality of distributions was assessed using the Shapiro-Wilk test and Q-Q plots. Depending on data distribution and variance homogeneity, between-group comparisons (MND vs HC and between MND subgroups) were performed using the Mann–Whitney U test, Welch’s t-test, or Student’s t-test for continuous variables, and the Chi-squared test for categorical variables. For prospective analyses, Cox proportional hazards models were used with death as the primary outcome. Models were adjusted for age, sex and baseline ALSFRS-R score and each biomarker was tested separately as the main predictor. Repeated measures ANOVA were conducted for DPR over time, adjusting for their respective baseline values, to assess longitudinal changes at the biomarker level and the influence of baseline characteristics. Statistical significance was set at p < 0.05 for all tests. Data analyses were performed using R version 4.3.1 and JASP. RESULTS Participants characteristics and CSF markers at baseline The study enrolled 100 subjects, namely 60 MND patients with confirmed diagnosis and 40 age-matched controls. Demographic and clinical characteristics, as well as CSF biomarkers distribution are highlighted in Table 1 and Fig. 1 . Motor neuron disease patients exhibited higher levels of GFAP, NfL, phosphorylated tau and total tau (p-Tau 181 and t-Tau) compared to HC. Levels of the synaptic protein CAP2 were higher in MND compared to HC whereas levels of SNAP-25 protein did not differ between MND and HC. At baseline, ALSFRS-R and DPR did not correlate with CAP2, SNAP-25, or any other CSF biomarker; only ALSFRS-R showed significant correlations with NfL and t-Tau. Table 1. Demographics and CSF biomarkers for HC and MND. Continuous variables are reported as median (IQR), and categorical variables are reported as numbers and percentages (n, %). HC (n=40) MND (n=60) p-value Age 65.10 (15.61) 67.32 (16.97) 0.184 a Sex (F) 22 (55%) 20 (33.3%) 0.043 b Disease Duration - 0.70 (1.13) - CSF Biomarkers GFAP [pg/mL] 4339.03 (3562.68) 10202.58 (6607.11) <0.001 a NfL [pg/mL] 604.53 (456.74) 3082.62 (3156.47) <0.001 a p-Tau 181 [pg/mL] 24.50 (19.10) 36.70 (19.60) <0.001 a t-Tau [pg/mL] 192.00 (123.00) 312.00 (178.00) <0.001 a CAP2 [pg/mL] 24.49 (12.28) 35.92 (13.66) <0.001 a SNAP-25 [pg/mL] 53.71 (30.53) 55.52 (31.56) 0.189 a Note: a Mann-Whitney U test, b χ² Chi-squared test. Abbreviations: HC, healthy controls; MND, motor neuron disease; GFAP, glial fibrillary acidic protein; NfL, neurofilament light chain; p-Tau 181, phosphorylated Tau 181; t-Tau, total Tau; CAP2, cyclase-associated protein 2; SNAP-25, synaptosomal-associated protein 25;. IQR = interquartile range (Q3–Q1). The correlation matrix, corrected for age and sex, showed that CAP2 behaves differently in MND compared to HC. CAP2 levels were significantly correlated with tau biomarkers in MND (p-Tau 181 and t-Tau respectively ρ = 0.349, p < 0.01; ρ = 0.448, p < 0.01), as shown in Fig. 2 . MND subjects with predominant upper motor neuron involvement exhibited higher NfL but comparable CAP2 increased levels compared to subjects with lower motor neuron involvement ( Supplementary Table 1 ). Predictive progression value of NfL, CAP2 Prospective 12-month follow-up data were available for all 60 patients included in the study. To assess the prognostic impact of NfL and CAP2 on survival in patients with MND, a Cox proportional hazards regression analysis was performed, adjusting for age, sex, and baseline ALSFRS-R scores. For each biomarker, patients were stratified into two groups, high and low, based on median values. The analysis revealed that higher baseline NfL levels were significantly associated with worse survival outcomes (hazard ratio [HR] = 2.51, 95% confidence interval [CI]: 1.2–5.1, p = 0.01), whereas CAP2 baseline levels alone were not significantly associated with clinical outcomes (p = 0.55). A repeated measures ANOVA was performed with DPR (i.e the rate of progression of ALSFRS from onset) as the within-subject factor (baseline and 12-month follow-up) and CSF biomarker levels as the dependent variable. Baseline DPR was included as a covariate to control interindividual variability in disease progression at baseline. A significant interaction was found between time and baseline NfL group (dichotomized by median value) (p < 0.001), indicating that patients with higher baseline NfL levels exhibited a different longitudinal trajectory in disease progression compared to those with lower levels. The same analytical approach was applied to CAP2, using NfL and baseline DPR as covariates, with no relevant interaction (p = 0.510). DISCUSSION In this study, we report for the first time that CSF levels of the postsynaptic protein CAP2 are significantly increased in patients with motor neuron disease (MND), whereas the levels of the presynaptic marker SNAP-25 remain unchanged. This contrasting pattern of synaptic protein alterations in MND may reflect differences in subcellular localization, disease-stage vulnerability, and pathophysiological mechanisms. Markers of axonal degeneration, such as NfL, have been extensively validated in MND [8]. In contrast, validated biomarkers of synaptic impairment are still lacking, despite growing recognition of synaptic dysfunction as a critical contributor to disease progression [4]. Our findings add to emerging evidence that synaptic dysfunction is an early and concomitant feature of MND, supporting the hypothesis that disturbances in synaptic physiology are closely linked to neuronal loss in neurodegenerative disorders. This is particularly relevant in light of the limited availability of large clinical biomarkers data, yet but mounting neuropathological and experimental evidence demonstrates presynaptic loss, dendritic spine remodeling, and excitatory/inhibitory imbalances in MND models and post-mortem tissues [24]. CAP2 is a postsynaptic actin-binding protein controlling the translocation of cofilin into dendritic spine in response to long-term potentiation, a process essential for actin‑mediated spine remodeling [25]. In contrast, SNAP-25 is a presynaptic SNARE protein essential for vesicle docking and neurotransmitter release [26,27]. The distinct compartmentalization of these proteins likely influences their dynamics in CSF: postsynaptic proteins such as CAP2 may be released during dendritic spine remodeling or cytoskeletal stress, whereas SNAP-25 release is more directly linked to presynaptic terminal loss. Synaptic pathology in MND is region- and stage-specific [28]. Post-mortem and experimental studies consistently have demonstrated early presynaptic protein loss in spinal cord and neuromuscular junction, including alterations in synaptophysin, synapsin, and SNAP-25 [27]. On the other hand, cortical synaptic compartments often show preserved or even increased excitatory spine density during early disease stages [29]. Considering its prominent postsynaptic localization [30] CAP2 may capture early cortical remodeling processes that are not tracked by presynaptic SNAP-25 [31]. In this study, we show that CSF CAP2 levels are elevated in MND compared to HC and do not merely reflect neuronal degeneration, as indicated by the lack of correlation with NfL. Of note, CAP2 levels were unrelated to the predominant involvement of upper versus lower motor neurons, clinical severity or survival, but - in MND patients only - were associated with p-Tau 181 and t-Tau pathology, both recognized features of the MND spectrum [19]. The significant correlation between CAP2 and tau biomarkers (p-Tau181 and t-Tau) observed in MND further supports a mechanistic link with cytoskeletal pathways. CAP2 and tau both contribute to actin–microtubule crosstalk, a process disrupted in MND and other neurodegenerative conditions [32,33]. In Alzheimer’s disease, CAP2 elevation has been reported in early stages and shown to correlate with tau pathology independently of amyloid burden [23], suggesting a conserved pathophysiological association between tau dysregulation and actin-remodeling proteins across disorders. The disease‑specific correlation between CAP2 and tau biomarkers in MND, absent in controls, points to selective engagement of disease-specific postsynaptic response. The independence of CAP2 from NfL and GFAP levels raises the possibility that CAP2 elevation reflects compensatory synaptic plasticity or maladaptive sprouting [9,34]. Such mechanisms may contribute to “motor reserve,” buffering the clinical impact of neuronal loss [35,36], while presynaptic markers like SNAP‑25 remain more closely tied to terminal degeneration. Although our findings are promising, several limitations warrant discussion. First, the sample size, while adequate for initial analysis, limits stratification by MND subtype (including bulbar vs spinal onset subtypes of disease other than UMN vs LMN-predominant forms), which may differ in their synaptic vulnerability. Second, CAP2 was quantified using a commercial ELISA, and further standardization is necessary for broader clinical application. Third, we did not assess other synaptic markers, which would have allowed comparative profiling of pre- and postsynaptic components. Future studies should validate CAP2 in larger longitudinal cohorts and investigate its association with imaging biomarkers of either cortical atrophy or synaptic density (e.g., SV2A PET). Furthermore, exploring the association between CAP2 and a broader panel of synaptic proteins beyond SNAP-25 including NPTX2 and neurogranin may help clarify its mechanistic role in MND synaptic pathology [37,38]. In conclusion, this study seems to indicate that MND is accompanied by an ongoing synaptic rearrangement which is closely related to cytoskeletal proteins, such as CAP2 and tau. These findings support a broader conceptual framework in which synaptic dysfunction and compensation might play key roles in MND subtypes definition and may open avenues for targeted therapeutic strategies aimed at preserving synaptic integrity. Declarations Acknowledgements The authors wish to thank the study participants who took part in this research. We are very grateful for the assistance received from all the nurses of the Neurology department of the Spedali Civili of Brescia. We want to thank especially the laboratory technicians of the Central Clinical Laboratory for their amazing availability. Funding declarations APi has been supported by grants of Airalzh Foundation AGYR2021 Life-Bio Grant, The LIMPE-DISMOV Foundation Segala Grant 2021, the Italian Ministry of University and Research PRIN COCOON (2017MYJ5TH) and PRIN 2021 RePlast (20202THZAW), PRIN 2022PNJS5Z and PRIn PNRR (P20224ZHM9), DIGI-BRAIN the H2020 IMI IDEA-FAST (ID853981), Italian Ministry of Health, Grant/Award Number: RF-2018-12366209, PNRR-Health PNRR-MAD-2022-12376110 and PNRR- MCNT2-2023-12378387, The MJFF Foundation Grant 022343, #NEXTGENERATIONEU (NGEU) funded by the Ministry of University and Research (MUR), National Recovery and Resilience Plan (NRRP), project MNESYS (PE0000006) – a multiscale integrated approach to the study of the nervous system in health and disease (DN. 1553 11.10.2022) – subproject DIGI-BRAIN; the European Union - Next Generation EU - NRRP M6C2 - Investment 2.1 Enhancement and strengthening of biomedical research in the NHS- PNRR – PNRR PNRR-Health PNRR-MAD-2022-12376110; PRIN 2020 Prot. 20202THZAW “RE-Plast: targeting functional and structural plasticity in Alzheimer disease. From diagnosis to treatment” and PRIn 2022 “P2022TKN8C” Extracellular network and related Genetic underpinnings as a hub in Alzheimer's Disease (EGADi). SP received funding from the Piano di Sostegno alla Ricerca (PSR), Università degli Studi di Milano (PSR2023_SPELU; PSR2025_SPELU). AC receives fundings from the LifeArc foundation, the Karin Christiane Conradi Stiftungsfonds, the Deutsche Gesellschaft für Muskelkranke e.V. (DGM; German Society for Muscle Diseases; project Ca2/1), the Frick-Foundation for ALS research, the Deutsche Forschungsgemeinschaft (DFG; German Research Foundation; projects CA 2915/4-1, CA 2915/10-1, and A01 within the SFB1506). MDL received funding from Italian Ministry of Research and University (MUR) (PRIN 20202THZAW and PRIN2022 PNRR P2022TKN8C, Fondo Italiano per la Scienza FIS00000560 - Stone to MDL). EM received funding from Italian Ministry of Research and University (MUR) (PRIN202039WMFP, PRIN2022 PNRR P2022R2E8N to EM), from the Giovanni Armenise Harvard Foundation and AIRALZH ONLUS (2023 Armenise Harvard-AIRALZH Mid-Career Award in Neurodegenerative Diseases - AHA MCA). APa has been supported by grants of the Italian Ministry of University and Research PRIN COCOON (2017MYJ5TH) and PRIN 2021 RePlast (20202THZAW), Prin 2022 EGADi (P2022TKN8C) the H2020 IMI IDEA-FAST (ID853981), DIGI-BRAIN Italian Ministry of Health, Grant/Award Number: RF-2018-12366209, RF-2019-12369272 and PNRR-Health PNRR-MAD-2022-12376110. Author contributions APa and APi contributed to the conceptualization and design of the study. APi and CT contributed to drafting the text or preparing the figures. AP, SP,CT, LF, LP, CT, IG, BL, EM contributed to the acquisition and analyses of data; APi, CT contributed to statistical analyses. AP, SP, CT, LF, LP, AC,BL, FG, LDA, RS, MdL EM and AP commented and revised the manuscript. All authors read and approved the final manuscript. Data Availability The data are available from the corresponding author upon reasonable request. Competing interests Andrea Pilotto received consultancy/speaker fees from Abbvie, Angelini, Bial, Eli Lilly, Lundbeck, Roche and Zambon pharmaceuticals. He acts as consultant as part of advisory Board of Angelini Pharma and BIAL pharmaceutics. Silvia Pelucchi declares no conflict of interest. Chiara Trasciatti declares no conflict of interest. Lucia Ferullo declares no conflict of interest. Loris Poli declares no conflict of interest. Chiara Tolassi declares no conflict of interest. Alberto Catanese declares no conflict of interest. Irene Girotto declares no conflict of interest. Beatrice Labella declares no conflict of interest. Federica Gorla declares no conflict of interest. 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He acts as consultant as part of advisory Board of Angelini Pharma and BIAL pharmaceutics. Silvia Pelucchi declares no conflict of interest. Chiara Trasciatti declares no conflict of interest. Lucia Ferullo declares no conflict of interest. Loris Poli declares no conflict of interest. Chiara Tolassi declares no conflict of interest. Alberto Catanese declares no conflict of interest. Irene Girotto declares no conflict of interest. Beatrice Labella declares no conflict of interest. Federica Gorla declares no conflict of interest. Laura D’Andrea declares no conflict of interest Ramona Stringhi declares no conflict of interest Monica di Luca received advisory board fees from Roche Elena Marcello received speaker fees from Eli Lilly and GE Healthcare, advisory board fees from Roche, teaching fees from Eisai Alessandro Padovani received personal compensation as a consultant/scientific advisory board member for Biogen, Eisai Eli Lilly, General Healthcare (GE), Lundbeck, Nestlè, Roche. Supplementary Files 251020supplementarytablemndcap2.docx Cite Share Download PDF Status: Published Journal Publication published 16 Feb, 2026 Read the published version in Scientific Reports → Version 1 posted Editorial decision: Revision requested 22 Dec, 2025 Reviews received at journal 12 Dec, 2025 Reviews received at journal 11 Dec, 2025 Reviewers agreed at journal 27 Nov, 2025 Reviewers agreed at journal 26 Nov, 2025 Reviewers agreed at journal 23 Nov, 2025 Reviewers invited by journal 03 Nov, 2025 Editor invited by journal 29 Oct, 2025 Editor assigned by journal 25 Oct, 2025 Submission checks completed at journal 25 Oct, 2025 First submitted to journal 23 Oct, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7933370","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":540367130,"identity":"7365f8ef-e0b6-4225-9883-ff4f8b2e903d","order_by":0,"name":"Andrea 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07:14:44","extension":"xml","order_by":8,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":79779,"visible":true,"origin":"","legend":"","description":"","filename":"8040e595d1e24704b829acd6604080e21structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-7933370/v1/30ad6a05f96530f5f4ee38c0.xml"},{"id":95877332,"identity":"b57f7548-014c-4f20-9190-cfb3c2788b14","added_by":"auto","created_at":"2025-11-14 01:41:59","extension":"html","order_by":9,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":93126,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-7933370/v1/7b8f30c42fee599884743d69.html"},{"id":95877323,"identity":"138b24d0-d389-4a11-b112-11fd83106271","added_by":"auto","created_at":"2025-11-14 01:41:58","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":190599,"visible":true,"origin":"","legend":"\u003cp\u003eViolin plots showing CSF levels of synaptic markers CAP2 and SNAP-25 in HC and MND patients. A significant increase in biomarker levels in MND is indicated by the star.\u003c/p\u003e\n\u003cp\u003eAbbreviations: HC, healthy controls; MND, motor neuron disease; NfL, neurofilament light chain; t-Tau, total Tau; CAP2, cyclase-associated protein 2; SNAP-25, synaptosomal-associated protein 25.\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-7933370/v1/13488384fb67f05514a760d0.png"},{"id":95877322,"identity":"78e234b2-a155-4028-9779-8b77d5bbecf6","added_by":"auto","created_at":"2025-11-14 01:41:58","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":248654,"visible":true,"origin":"","legend":"\u003cp\u003eSpearman’s correlation matrix corrected for age and sex including all the CSF biomarkers analysed in the cohort.\u003c/p\u003e\n\u003cp\u003eAbbreviations: HC, healthy controls; MND, motor neuron disease; GFAP, glial fibrillary acidic protein; NfL, neurofilament light chain; p-Tau 181, phosphorylated Tau 181; t-Tau, total Tau; CAP2, cyclase-associated protein 2; SNAP-25, synaptosomal-associated protein 25.\u003c/p\u003e","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-7933370/v1/ab71311758d99396c48e5536.png"},{"id":103252176,"identity":"abe422d2-0039-4814-9212-01ec77c4f9b1","added_by":"auto","created_at":"2026-02-23 16:13:14","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1093783,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7933370/v1/2acde5e8-fefd-47bf-a3bc-20a5d7ea5cbf.pdf"},{"id":95877324,"identity":"e699b858-b228-4e8d-afd5-c6c94cc3adc7","added_by":"auto","created_at":"2025-11-14 01:41:58","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":17292,"visible":true,"origin":"","legend":"","description":"","filename":"251020supplementarytablemndcap2.docx","url":"https://assets-eu.researchsquare.com/files/rs-7933370/v1/a11ddb18e9284ba2829b37d2.docx"}],"financialInterests":"Competing interest reported. Andrea Pilotto received consultancy/speaker fees from Abbvie, Angelini, Bial, Eli Lilly, Lundbeck, Roche and Zambon pharmaceuticals. He acts as consultant as part of advisory Board of Angelini Pharma and BIAL pharmaceutics. \nSilvia Pelucchi declares no conflict of interest.\nChiara Trasciatti declares no conflict of interest.\nLucia Ferullo declares no conflict of interest.\nLoris Poli declares no conflict of interest.\nChiara Tolassi declares no conflict of interest.\nAlberto Catanese declares no conflict of interest.\nIrene Girotto declares no conflict of interest.\nBeatrice Labella declares no conflict of interest.\nFederica Gorla declares no conflict of interest.\nLaura D’Andrea declares no conflict of interest\n Ramona Stringhi declares no conflict of interest\nMonica di Luca received advisory board fees from Roche\nElena Marcello received speaker fees from Eli Lilly and GE Healthcare, advisory board fees from Roche, teaching fees from Eisai\nAlessandro Padovani received personal compensation as a consultant/scientific advisory board member for Biogen, Eisai Eli Lilly, General Healthcare (GE), Lundbeck, Nestlè, Roche.","formattedTitle":"Synaptic and Cytoskeletal CSF Signatures of Motor Neuron Disease: The Role of Cyclase-Associated Protein 2","fulltext":[{"header":"INTRODUCTION","content":"\u003cp\u003eSynaptic dysfunction is increasingly recognized as a critical early event in the pathogenesis of neurodegenerative diseases [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Long before neuronal death becomes evident, synaptic alterations disrupt communication within neural circuits, contributing to neurological impairments. These insights have spurred extensive efforts to identify cerebrospinal fluid (CSF) biomarkers reflecting synaptic integrity, including neurogranin, GAP43, SNAP-25, and PSD-95 [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eSynaptic pathology in motor neuron diseases (MND) has been less investigated [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Nevertheless, a growing body of research highlights that synaptic degeneration is a prominent and early feature of MND. Human and animal studies consistently show a loss of presynaptic proteins such as synaptophysin, SNAP-25, and syntaxin in the spinal cord and neuromuscular junction [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Changes in excitatory and inhibitory neurotransmission, including imbalances in glutamate and GABA receptor subunits, and the synaptic mislocalization of proteins such as FUS and TDP-43, further underscore the role of synaptic alterations in disease progression [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eDespite these findings, few fluid biomarkers have been established to reflect neuronal and synaptic pathology in MND. Most studies to date have focused on axonal damage markers such as neurofilament light chain (NfL) and phosphorylated neurofilament heavy chain (pNfH), which consistently demonstrate high sensitivity and prognostic value [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Synaptic proteins in cerebrospinal fluid (CSF), including SNAP-25 and neurogranin appeared to be less studied in MND, with still discussed findings [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Nevertheless, the recent evidence that the neuronal pentraxins might represent a valid readout for therapy responsiveness in ALS [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e] increased the potential clinical relevance of synaptic biomarkers in MND.\u003c/p\u003e\u003cp\u003eIn this context, cyclase-associated protein 2 (CAP2) fits within the framework of synaptic markers. CAP2 belongs to the CAP protein family, actin-binding proteins that regulate actin dynamics. While the isoform CAP1 is widely expressed, CAP2 expression is restricted to a few organs, including the brain and skeletal muscles [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. In skeletal muscle, CAP2 emerges as a critical regulator of skeletal muscle development and function, primarily through its role in actin cytoskeleton dynamics and myofibril differentiation [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. In neurons, CAP2 is a postsynaptic protein that modulates dendritic spine morphology and facilitates cofilin 1-mediated spine remodeling during synaptic plasticity events [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eGiven the mounting evidence of early synaptic involvement in MND and the functional importance of CAP2 in synaptic and myofibril function, we measured CSF CAP2 concentration in patients with MND compared to healthy controls and explore its relationship with CSF markers such as phospho-Tau total Tau, NfL and GFAP. Furthermore, the association with clinical subtypes of the disease and the prognostic value of CAP2 levels was assessed longitudinally in the MND cohort.\u003c/p\u003e"},{"header":"METHODS","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003eStudy population\u003c/h2\u003e\u003cp\u003ePatients with Gold Coast criteria [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e] for motor neuron disease (MND) diagnosis were consecutively enrolled at the outpatient Neuromuscular Clinic at Brescia University Hospital. Individuals were included according to the following exclusion criteria: (1) age\u0026thinsp;\u0026lt;\u0026thinsp;55 years; (2) dementia or significant cognitive changes reported; (3) abnormal cognitive screening according to Montreal Cognitive Assessment (MoCA\u0026thinsp;\u0026lt;\u0026thinsp;26); (4) medical conditions potentially associated with cognitive deficits or movement/gait alterations; (5) major psychiatric disorders (6) recent acute fever/inflammation/concussion.\u003c/p\u003e\u003cp\u003eFor each subject, the following data were collected: (1) demographic details and clinical characteristics, including the region of symptom onset; (2) presence of upper motor neuron (UMN) signs (e.g., hyperreflexia, spasticity, and pseudobulbar features) and lower motor neuron (LMN) signs (e.g. muscle wasting, fasciculations, and hyporeflexia).\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003eClinical assessment\u003c/h3\u003e\n\u003cp\u003eAt baseline, all suspected motor neuron disease patients underwent a comprehensive clinical and diagnostic work-up including CSF. All patients underwent brain and spinal cord MRI, electromyography and motor/sensory evoked potential, as well as biochemical screening, according to current standard of care and MND diagnosis [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. Assessment of UMN and LMN was defined by neurological examination and supported by electrodiagnostic studies [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. The Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R) was used to assess disease severity [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. DPR was defined as (48-ALSFRS-R)/disease duration (points per month) and calculated at first visit, as well as 12 months follow-up [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eFor biomarker comparison, an age-matched group of controls who underwent CSF analyses for isolated persistent headache, but any other neurological symptom or MRI/EEG/CSF alteration, was included and considered as negative controls, as previously described [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. The study was approved by the local ethics committee (NP 1471, DMA, Brescia) and was performed in conformity with the Helsinki Declaration; informed consent was obtained from each study participant or their legally authorized representative.\u003c/p\u003e\n\u003ch3\u003eCSF collection and analysis\u003c/h3\u003e\n\u003cp\u003eCSF collection was performed in fasting condition according to the standardized protocol of the outpatient clinic, from 09:00 to 11:00 in the morning, after clinical informed written consent was obtained. CSF was collected in sterile polypropylene tubes and gently mixed to avoid gradient effects. CSF was centrifugated and firstly processed for standard biochemical analyses, whereas two milliliters of CSF were stored in cryotubes at \u0026minus;\u0026thinsp;80\u0026deg;C before biomarkers testing. As by the guidelines delivered by the Consensus of the Task Force on Biological Markers in Psychiatry of the World Federation of Societies of Biological Psychiatry, CSF samples were subjected to a maximum of two freeze-thaw cycles [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. Only patients with normal routine measures were included in further analyses.\u003c/p\u003e\n\u003ch3\u003eCSF neuronal, glial and synaptic markers\u003c/h3\u003e\n\u003cp\u003eCSF p-Tau181, and total tau were measured using the Lumipulse G assays (Fujirebio) on the LUMIPULSE G600II for diagnostic standard analyses performed at Central Chemical Analysis Laboratory, as previously reported [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. All CSF samples were additionally analyzed for neuronal (neurofilament light chain, NfL), glial (glial fibrillary acidic protein, GFAP) and synaptic markers, namely SNAP-25 and CAP2. CSF SIMOA analyses were conducted by researchers who were blind to the origin of plasma biomarkers, at the Laboratory of Advanced Biological Markers at the University of Brescia, utilizing the SR-X platform and the Neurology 2-Plex Advantage Kits (NfL/GFAP) and SNAP-25 kit (single-plex) from Quanterix, Billerica, MA.\u003c/p\u003e\u003cp\u003eCAP2 was measured using enzyme-linked immunosorbent assays (ELISA) performed at the Department of Pharmacological and Biomolecular Sciences (University of Milan), as previously reported [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. Briefly, the CSF samples were diluted at 1:20, and their CAP2 concentration was determined using a commercially available ELISA (catalog number IK5163; Immunological Sciences, Rome, Italy). This assay has high sensitivity and specificity for CAP2 detection; no significant cross-reactivity or interference between CAP2 and its analogs was observed. The mean of duplicate assessment was used for final analysis.\u003c/p\u003e\n\u003ch3\u003eStatistical analyses\u003c/h3\u003e\n\u003cp\u003eContinuous variables are reported as median (interquartile range), and categorical variables are reported as numbers and percentages (n, %). The normality of distributions was assessed using the Shapiro-Wilk test and Q-Q plots. Depending on data distribution and variance homogeneity, between-group comparisons (MND vs HC and between MND subgroups) were performed using the Mann\u0026ndash;Whitney U test, Welch\u0026rsquo;s t-test, or Student\u0026rsquo;s t-test for continuous variables, and the Chi-squared test for categorical variables. For prospective analyses, Cox proportional hazards models were used with death as the primary outcome. Models were adjusted for age, sex and baseline ALSFRS-R score and each biomarker was tested separately as the main predictor. Repeated measures ANOVA were conducted for DPR over time, adjusting for their respective baseline values, to assess longitudinal changes at the biomarker level and the influence of baseline characteristics. Statistical significance was set at p\u0026thinsp;\u0026lt;\u0026thinsp;0.05 for all tests. Data analyses were performed using R version 4.3.1 and JASP.\u003c/p\u003e"},{"header":"RESULTS","content":"\u003cp\u003e\u003cstrong\u003eParticipants characteristics and CSF markers at baseline\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study enrolled 100 subjects, namely 60 MND patients with confirmed diagnosis and 40 age-matched controls. Demographic and clinical characteristics, as well as CSF biomarkers distribution are highlighted in \u003cstrong\u003eTable 1\u0026nbsp;\u003c/strong\u003eand \u003cstrong\u003eFig. 1\u003c/strong\u003e. Motor neuron disease patients exhibited higher levels of GFAP, NfL, phosphorylated tau and total tau (p-Tau 181 and t-Tau) compared to HC. Levels of the synaptic protein CAP2 were higher in MND compared to HC whereas levels of SNAP-25 protein did not differ between MND and HC. At baseline, ALSFRS-R and DPR did not correlate with CAP2, SNAP-25, or any other CSF biomarker; only ALSFRS-R showed significant correlations with NfL and t-Tau.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 1.\u003c/strong\u003e Demographics and CSF biomarkers for HC and MND. Continuous variables are reported as median (IQR), and categorical variables are reported as numbers and percentages (n, %).\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"594\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 193px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 154px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eHC\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e(n=40)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 161px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eMND\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e(n=60)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 86px;\"\u003e\n \u003cp\u003e\u003cstrong\u003ep-value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 193px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eAge\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 154px;\"\u003e\n \u003cp\u003e65.10 (15.61)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 161px;\"\u003e\n \u003cp\u003e67.32 (16.97)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 86px;\"\u003e\n \u003cp\u003e0.184\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 193px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eSex (F)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 154px;\"\u003e\n \u003cp\u003e22 (55%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 161px;\"\u003e\n \u003cp\u003e20 (33.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 86px;\"\u003e\n \u003cp\u003e0.043\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 193px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eDisease Duration\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 154px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 161px;\"\u003e\n \u003cp\u003e0.70 (1.13)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 86px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"4\" style=\"width: 594px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eCSF Biomarkers\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 193px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eGFAP [pg/mL]\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 154px;\"\u003e\n \u003cp\u003e4339.03 (3562.68)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 161px;\"\u003e\n \u003cp\u003e10202.58 (6607.11)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 86px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 193px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eNfL [pg/mL]\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 154px;\"\u003e\n \u003cp\u003e604.53 (456.74)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 161px;\"\u003e\n \u003cp\u003e3082.62 (3156.47)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 86px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 193px;\"\u003e\n \u003cp\u003e\u003cstrong\u003ep-Tau 181 [pg/mL]\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 154px;\"\u003e\n \u003cp\u003e24.50 (19.10)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 161px;\"\u003e\n \u003cp\u003e36.70 (19.60)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 86px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 193px;\"\u003e\n \u003cp\u003e\u003cstrong\u003et-Tau [pg/mL]\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 154px;\"\u003e\n \u003cp\u003e192.00 (123.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 161px;\"\u003e\n \u003cp\u003e312.00 (178.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 86px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 193px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eCAP2 [pg/mL]\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 154px;\"\u003e\n \u003cp\u003e24.49 (12.28)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 161px;\"\u003e\n \u003cp\u003e35.92 (13.66)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 86px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 193px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eSNAP-25 [pg/mL]\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 154px;\"\u003e\n \u003cp\u003e53.71 (30.53)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 161px;\"\u003e\n \u003cp\u003e55.52 (31.56)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 86px;\"\u003e\n \u003cp\u003e0.189\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"4\" style=\"width: 594px;\"\u003e\n \u003cp\u003eNote: \u003csup\u003ea\u0026nbsp;\u003c/sup\u003eMann-Whitney U test, \u003csup\u003eb\u0026nbsp;\u003c/sup\u003e\u0026chi;\u0026sup2; Chi-squared test.\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003eAbbreviations:\u0026nbsp;\u003c/strong\u003eHC, healthy controls; MND, motor neuron disease; GFAP, glial fibrillary acidic protein; NfL, neurofilament light chain; p-Tau 181, phosphorylated Tau 181; \u0026nbsp;t-Tau, total Tau; CAP2, cyclase-associated protein 2; SNAP-25, synaptosomal-associated protein 25;. IQR = interquartile range (Q3\u0026ndash;Q1).\u003c/p\u003e\n\u003cp\u003eThe correlation matrix, corrected for age and sex, showed that CAP2 behaves differently in MND compared to HC. CAP2 levels were significantly correlated with tau biomarkers in MND (p-Tau 181 and t-Tau respectively \u0026rho; = 0.349, p \u0026lt; 0.01; \u0026nbsp;\u0026rho; = 0.448, p \u0026lt; 0.01), as shown in \u003cstrong\u003eFig. 2\u003c/strong\u003e. \u0026nbsp;MND subjects with predominant upper motor neuron involvement exhibited higher NfL but comparable CAP2 increased levels compared to subjects with lower motor neuron involvement (\u003cstrong\u003eSupplementary Table 1\u003c/strong\u003e).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePredictive progression value of NfL, CAP2\u0026nbsp;\u003cbr\u003e\u003c/strong\u003eProspective 12-month follow-up data were available for all 60 patients included in the study. To assess the prognostic impact of NfL and CAP2 on survival in patients with MND, a Cox proportional hazards regression analysis was performed, adjusting for age, sex, and baseline ALSFRS-R scores. For each biomarker, patients were stratified into two groups, high and low, based on median values. The analysis revealed that higher baseline NfL levels were significantly associated with worse survival outcomes (hazard ratio [HR] = 2.51, 95% confidence interval [CI]: 1.2\u0026ndash;5.1, p = 0.01), whereas CAP2 baseline levels alone were not significantly associated with clinical outcomes (p = 0.55).\u003c/p\u003e\n\u003cp\u003eA repeated measures ANOVA was performed with DPR (i.e the rate of progression of ALSFRS from onset) as the within-subject factor (baseline and 12-month follow-up) and CSF biomarker levels as the dependent variable. Baseline DPR was included as a covariate to control interindividual variability in disease progression at baseline. A significant interaction was found between time and baseline NfL group (dichotomized by median value) (p \u0026lt; 0.001), indicating that patients with higher baseline NfL levels exhibited a different longitudinal trajectory in disease progression compared to those with lower levels. The same analytical approach was applied to CAP2, using NfL and baseline DPR as covariates, with no relevant interaction (p = 0.510).\u0026nbsp;\u003c/p\u003e"},{"header":"DISCUSSION","content":"\u003cp\u003eIn this study, we report for the first time that CSF levels of the postsynaptic protein CAP2 are significantly increased in patients with motor neuron disease (MND), whereas the levels of the presynaptic marker SNAP-25 remain unchanged. This contrasting pattern of synaptic protein alterations in MND\u0026nbsp;may reflect differences in subcellular localization, disease-stage vulnerability, and pathophysiological mechanisms.\u003c/p\u003e\n\u003cp\u003eMarkers of axonal degeneration, such as NfL, have been extensively validated in MND [8]. In contrast, validated biomarkers of synaptic impairment are still lacking, despite growing recognition of synaptic dysfunction as a critical contributor to disease progression [4]. Our findings add to emerging evidence that synaptic dysfunction is an early and concomitant feature of MND, supporting the hypothesis that disturbances in synaptic physiology are closely linked to neuronal loss in neurodegenerative disorders.\u003c/p\u003e\n\u003cp\u003eThis is particularly relevant in light of the limited availability of large clinical biomarkers data, yet but mounting neuropathological and experimental evidence demonstrates presynaptic loss, dendritic spine remodeling, and excitatory/inhibitory imbalances in MND models and post-mortem tissues [24].\u003c/p\u003e\n\u003cp\u003eCAP2 is a postsynaptic actin-binding protein controlling the translocation of cofilin into dendritic spine in response to long-term potentiation, a process essential for actin‑mediated spine remodeling [25]. In contrast, SNAP-25 is a presynaptic SNARE protein essential for vesicle docking and neurotransmitter release [26,27]. The distinct compartmentalization of these proteins likely influences their dynamics in CSF: postsynaptic proteins such as CAP2 may be released during dendritic spine remodeling or cytoskeletal stress, whereas SNAP-25 release is more directly linked to presynaptic terminal loss.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eSynaptic pathology in MND is region- and stage-specific [28]. Post-mortem and experimental studies consistently have demonstrated early presynaptic protein loss in spinal cord and neuromuscular junction, including alterations in synaptophysin, synapsin, and SNAP-25 [27]. On the other hand, cortical synaptic compartments often show preserved or even increased excitatory spine density during early disease stages [29]. Considering its prominent postsynaptic localization [30] CAP2 may capture early cortical remodeling processes that are not tracked by presynaptic SNAP-25 [31].\u0026nbsp;\u003cbr\u003e\u0026nbsp;\u003cbr\u003eIn this study, we show that CSF CAP2 levels are elevated in MND compared to HC and do not merely reflect neuronal degeneration, as indicated by the lack of correlation with NfL. Of note, CAP2 levels were unrelated to the predominant involvement of upper versus lower motor neurons, clinical severity or survival, but - in MND patients only - were associated with p-Tau 181 and t-Tau pathology, both recognized features of the MND spectrum [19]. The significant correlation between CAP2 and tau biomarkers (p-Tau181 and t-Tau) observed in MND further supports a mechanistic link with cytoskeletal pathways. CAP2 and tau both contribute to actin–microtubule crosstalk, a process disrupted in MND and other neurodegenerative conditions [32,33]. In Alzheimer’s disease, CAP2 elevation has been reported in early stages and shown to correlate with tau pathology independently of amyloid burden [23], suggesting a conserved pathophysiological association between tau dysregulation and actin-remodeling proteins across disorders. The disease‑specific correlation between CAP2 and tau biomarkers in MND, absent in controls, points to selective engagement of disease-specific postsynaptic response. The independence of CAP2 from NfL and GFAP levels raises the possibility that CAP2 elevation reflects compensatory synaptic plasticity or maladaptive sprouting [9,34]. Such mechanisms may contribute to “motor reserve,” buffering the clinical impact of neuronal loss [35,36], while presynaptic markers like SNAP‑25 remain more closely tied to terminal degeneration.\u003c/p\u003e\n\u003cp\u003eAlthough our findings are promising, several limitations warrant discussion. First, the sample size, while adequate for initial analysis, limits stratification by MND subtype (including bulbar vs spinal onset subtypes of disease other than UMN vs LMN-predominant forms), which may differ in their synaptic vulnerability. Second, CAP2 was quantified using a commercial ELISA, and further standardization is necessary for broader clinical application. Third, we did not assess other synaptic markers, which would have allowed comparative profiling of pre- and postsynaptic components.\u003c/p\u003e\n\u003cp\u003eFuture studies should validate CAP2 in larger longitudinal cohorts and investigate its association with imaging biomarkers of either cortical atrophy or synaptic density (e.g., SV2A PET). Furthermore, exploring the association between CAP2 and a broader panel of synaptic proteins beyond SNAP-25 including NPTX2 and neurogranin may help clarify its mechanistic role in MND synaptic pathology [37,38].\u003c/p\u003e\n\u003cp\u003eIn conclusion, this study seems to indicate that MND is accompanied by an ongoing synaptic rearrangement which is closely related to cytoskeletal proteins, such as CAP2 and tau. These findings support a broader conceptual framework in which synaptic dysfunction and compensation might play key roles in MND subtypes definition and may open avenues for targeted therapeutic strategies aimed at preserving synaptic integrity.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors wish to thank the study participants who took part in this research. We are very grateful for the assistance received from all the nurses of the Neurology department of the Spedali Civili of Brescia. We want to thank especially the laboratory technicians of the Central Clinical Laboratory for their amazing availability.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding declarations\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAPi has been supported by grants of Airalzh Foundation AGYR2021 Life-Bio Grant, The LIMPE-DISMOV Foundation Segala Grant 2021, the Italian Ministry of University and Research PRIN COCOON (2017MYJ5TH) and PRIN 2021 RePlast (20202THZAW), PRIN 2022PNJS5Z and \u0026nbsp;PRIn PNRR (P20224ZHM9), DIGI-BRAIN the H2020 IMI IDEA-FAST (ID853981), Italian Ministry of Health, Grant/Award Number: RF-2018-12366209, PNRR-Health PNRR-MAD-2022-12376110 and PNRR- MCNT2-2023-12378387, The MJFF Foundation Grant 022343, #NEXTGENERATIONEU (NGEU) funded by the Ministry of University and Research (MUR), National Recovery and Resilience Plan (NRRP), project MNESYS (PE0000006) – a multiscale integrated approach to the study of the nervous system in health and disease (DN. 1553 11.10.2022) – subproject DIGI-BRAIN; the European Union - Next Generation EU - NRRP M6C2 - Investment 2.1 Enhancement and strengthening of biomedical research in the NHS- PNRR – PNRR PNRR-Health PNRR-MAD-2022-12376110; \u0026nbsp; PRIN 2020 Prot. 20202THZAW “RE-Plast: targeting functional and structural plasticity in Alzheimer disease. From diagnosis to treatment” and PRIn 2022 “P2022TKN8C” Extracellular network and related Genetic underpinnings as a hub in Alzheimer's Disease (EGADi).\u003c/p\u003e\n\u003cp\u003eSP received funding from the \u003cem\u003ePiano di Sostegno alla Ricerca (PSR), Università degli Studi di Milano\u003c/em\u003e (PSR2023_SPELU; PSR2025_SPELU).\u003c/p\u003e\n\u003cp\u003eAC receives fundings from the LifeArc foundation, the Karin Christiane Conradi Stiftungsfonds, the Deutsche Gesellschaft für Muskelkranke e.V. (DGM; German Society for Muscle Diseases; project Ca2/1), the Frick-Foundation for ALS research, the Deutsche Forschungsgemeinschaft (DFG; German Research Foundation; projects CA 2915/4-1, CA 2915/10-1, and A01 within the SFB1506).\u003c/p\u003e\n\u003cp\u003eMDL received funding from Italian Ministry of Research and University (MUR) (PRIN 20202THZAW and PRIN2022 PNRR P2022TKN8C, Fondo Italiano per la Scienza FIS00000560 - Stone to MDL).\u003c/p\u003e\n\u003cp\u003eEM received funding from Italian Ministry of Research and University (MUR) (PRIN202039WMFP, PRIN2022 PNRR P2022R2E8N to EM), from the Giovanni Armenise Harvard Foundation and AIRALZH ONLUS (2023 Armenise Harvard-AIRALZH Mid-Career Award in Neurodegenerative Diseases - AHA MCA).\u003c/p\u003e\n\u003cp\u003eAPa has been supported by grants of the Italian Ministry of University and Research PRIN COCOON (2017MYJ5TH) and PRIN 2021 RePlast (20202THZAW), Prin 2022 EGADi (P2022TKN8C) the H2020 IMI IDEA-FAST (ID853981), DIGI-BRAIN Italian Ministry of Health, Grant/Award Number: RF-2018-12366209, RF-2019-12369272 and PNRR-Health PNRR-MAD-2022-12376110.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAPa and APi contributed to the conceptualization and design of the study. APi and CT contributed to drafting the text or preparing the figures. AP, SP,CT, LF, LP, CT, IG, BL, EM \u0026nbsp;contributed to the acquisition and analyses of data; \u0026nbsp;APi, CT contributed to statistical analyses. AP, SP, CT, LF, LP, AC,BL, FG, LDA, RS, MdL EM and AP \u0026nbsp;commented and revised the manuscript. All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData Availability\u003c/strong\u003e\u003cbr\u003e\u0026nbsp;The data are available from the corresponding author upon reasonable request.\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAndrea Pilotto received consultancy/speaker fees from Abbvie, Angelini, Bial, Eli Lilly, Lundbeck, Roche and Zambon pharmaceuticals. He acts as consultant as part of advisory Board of Angelini Pharma and BIAL pharmaceutics.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eSilvia Pelucchi declares no conflict of interest.\u003c/p\u003e\n\u003cp\u003eChiara Trasciatti declares no conflict of interest.\u003c/p\u003e\n\u003cp\u003eLucia Ferullo declares no conflict of interest.\u003c/p\u003e\n\u003cp\u003eLoris Poli declares no conflict of interest.\u003c/p\u003e\n\u003cp\u003eChiara Tolassi declares no conflict of interest.\u003c/p\u003e\n\u003cp\u003eAlberto Catanese declares no conflict of interest.\u003c/p\u003e\n\u003cp\u003eIrene Girotto declares no conflict of interest.\u003c/p\u003e\n\u003cp\u003eBeatrice Labella declares no conflict of interest.\u003c/p\u003e\n\u003cp\u003eFederica Gorla declares no conflict of interest.\u003c/p\u003e\n\u003cp\u003eLaura D’Andrea declares no conflict of interest\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;Ramona Stringhi declares no conflict of interest\u003c/p\u003e\n\u003cp\u003eMonica di Luca received advisory board fees from Roche\u003c/p\u003e\n\u003cp\u003eElena Marcello received speaker fees from Eli Lilly and GE Healthcare, advisory board fees from Roche, teaching fees from Eisai\u003c/p\u003e\n\u003cp\u003eAlessandro Padovani received personal compensation as a consultant/scientific advisory board member for Biogen, Eisai Eli Lilly, General Healthcare (GE), Lundbeck, Nestlè, Roche.\u003cbr\u003e\u0026nbsp;\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eCamporesi, E. et al. 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Biomarker discovery in Alzheimer\u0026rsquo;s and neurodegenerative diseases using Nucleic Acid Linked Immuno-Sandwich Assay. \u003cem\u003eAlzheimer\u0026rsquo;s Dement.\u003c/em\u003e \u003cb\u003e21\u003c/b\u003e, e14621 (2025).\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"motor neuron disease (MND), synaptic biomarkers, neurofilament light chain (NfL), cerebrospinal fluid (CSF)","lastPublishedDoi":"10.21203/rs.3.rs-7933370/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7933370/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eCyclase-associated protein 2 (CAP2), is a synaptic actin-binding protein involved in cofilin-mediated spine remodelling, Alzheimer's Disease synaptic failure and myofibril maintenance, indicating its potential involvement in MND.\u003c/p\u003e\u003cp\u003eThis study examined CSF levels of CAP2 in 60 patients with motor neuron disease (MND) and 40 healthy controls (HC) to assess its diagnostic and prognostic value and its relationship with neuronal, glial and synaptic markers.\u003c/p\u003e\u003cp\u003eGlial fibrillary acidic protein (GFAP), neurofilament light chain (NfL), phosphorylated and total tau (p-Tau 181, t-Tau), CAP2 and synaptosomal-associated protein 25 (SNAP-25) were quantified using ELISA, Lumipulse and SIMOA platforms.\u003c/p\u003e\u003cp\u003eMND patients displayed increased GFAP, NfL, t-Tau, p-Tau 181 levels and CAP2 while SNAP-25 was reduced. CAP2 correlated with tau markers, but not with NfL or GFAP. Unlike NfL, which was higher in upper motor neuron\u0026ndash;predominant cases and predicted faster progression and poorer survival, CAP2 did not vary with disease subtypes or severity.\u003c/p\u003e\u003cp\u003eThe study showed that CAP2 is associated with MND independently from neuronal, glial and presynaptic dysfunction. Integrating CAP2 into multi-marker panels could enhance understanding of synaptic pathology in MND.\u003c/p\u003e","manuscriptTitle":"Synaptic and Cytoskeletal CSF Signatures of Motor Neuron Disease: The Role of Cyclase-Associated Protein 2","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-11-14 01:41:54","doi":"10.21203/rs.3.rs-7933370/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-12-22T10:26:43+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-12-12T10:48:47+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-12-11T11:15:38+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"304443038844617345183880412492553775716","date":"2025-11-27T07:47:26+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"170170324680483857797430396737617857558","date":"2025-11-26T14:37:03+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"196904515204670370593754530931505981779","date":"2025-11-23T21:29:09+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-11-03T09:55:23+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-10-29T08:45:06+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-10-25T12:19:51+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-10-25T12:17:57+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2025-10-23T14:43:48+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"d3a49cb7-9c5d-49db-8071-a9928b69264d","owner":[],"postedDate":"November 14th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":57479507,"name":"Health sciences/Neurology"},{"id":57479508,"name":"Biological sciences/Neuroscience"}],"tags":[],"updatedAt":"2026-02-23T16:07:26+00:00","versionOfRecord":{"articleIdentity":"rs-7933370","link":"https://doi.org/10.1038/s41598-026-39274-0","journal":{"identity":"scientific-reports","isVorOnly":false,"title":"Scientific Reports"},"publishedOn":"2026-02-16 15:58:43","publishedOnDateReadable":"February 16th, 2026"},"versionCreatedAt":"2025-11-14 01:41:54","video":"","vorDoi":"10.1038/s41598-026-39274-0","vorDoiUrl":"https://doi.org/10.1038/s41598-026-39274-0","workflowStages":[]},"version":"v1","identity":"rs-7933370","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7933370","identity":"rs-7933370","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}