Technical success, procedural safety, and efficacy of the Silk Vista Baby in the treatment of cerebral aneurysms over a mid-to-long-term follow-up.

Background: Long-term follow-up of cerebral aneurysms treated with the Silk Vista Baby (SVB) flow diverter is lacking. This study aimed to assess the technical success, procedural safety, and efficacy of the SVB (Balt, Montmorency, France) for the treatment of intracranial aneurysms in small cerebral vessels over a mid-to long-term follow-up. Methods: We retrospectively analyzed a prospectively maintained database of patients treated with the SVB between September 2018 and June 2021. Data regarding patient demographics, aneurysm characteristics, and technical procedures were also collected. Angiographic and clinical findings were recorded during the procedure and over a period of at least 12 months. Results: Angiographic and clinical follow-up data were available for 50 patients/50 aneurysms. The procedural complication rate was 8%. At 12 months, the final results showed a technical success rate of 100%, the re rupture rate was 0%, neuromorbidity and mortality rates of 4 and 0%, respectively, and an almost complete occlusion rate of 94%. Conclusion: Treatment of complex intracranial aneurysms with the SVB was safe and effective. Long-term results showed high rates of adequate and stable occlusions.

Aortic valve Replacement compared to Transcatheter Implant and its relationship with COgnitive Impairment (ARTICO) evaluated with neuropsychological and advanced neuroimaging: a longitudinal cohort study.

BACKGROUND: Aortic stenosis is the most common valvulopathy in Western countries. The treatment of choice had been surgery aortic valve replacement (SAVR), but the improvement in endovascular approaches as transcatheter aortic valve implantation (TAVI), initially reserved for patients with very high surgical risk, has been extended to high and intermediate, and recently also to low-risk patients. Stroke and vascular cognitive impairment are the most important complications. It is not entirely clear which technique is best to avoid these complications as well as their impact. Our goal is to evaluate changes in cognitive performance in the early (1-month) and late (1-year) postoperative period in patients undergoing SAVR or TAVI, by extensive neuropsychological study (NRP) and advanced Magnetic Resonance Imaging (MRI). Specifically, to compare early and late cognitive changes after the intervention between both groups, the occurrence of stroke during follow-up and to compare the appearance of silent vascular lesions and changes in brain activity and functional connectivity with functional MRI during follow-up between both groups. METHODS/DESIGN: Prospective longitudinal cohort study. A non-selected representative sample of 80 subjects, 40 SAVR and 40 TAVI to obtain a final sample of 36 eligible subjects in each group, ranging from 70 to 85 years old, with indication for aortic replacement and intermediate or high surgical risk will be studied. At baseline, within one month before the treatment, all individuals will undergo an extensive NRP and advanced MRI study. These studies will also be performed 1-month and 1-year after treatment, to assess the appearance of new vascular lesions, as well as changes in cognitive performance with respect to baseline. DISCUSSION: This study aims to evaluate changes in cognitive performance as well as both clinical and silent vascular events occurring in the early (1-month) and late (1-year) periods after SAVR and TAVI. We will also analyze the correlation between neuropsychological and neuroimaging approaches in order to evaluate cognition. Therefore, it may provide high-quality data of cognitive changes and vascular events for both techniques, and be useful to tailor interventions to individual characteristics and ultimately aiding in decision-making. TRIAL REGISTRATION: This study is register in Clinicaltrials.gov (NCT05235529) on 11th February 2022.

Synthesis of Structurally Related Coumarin Derivatives as Antiproliferative Agents.

A library of structurally related coumarins was generated through synthesis reactions and chemical modification reactions to obtain derivatives with antiproliferative activity both in vivo and in vitro. Out of a total of 35 structurally related coumarin derivatives, seven of them showed inhibitory activity in in vitro tests against Taq DNA polymerase with IC50 values lower than 250 µM. The derivatives 4-(chloromethyl)-5,7-dihydroxy-2H-chromen-2-one (2d) and 4-((acetylthio)methyl)-2-oxo-2H-chromen-7-yl acetate (3c) showed the most promising anti-polymerase activity with IC50 values of 20.7 ± 2.10 and 48.25 ± 1.20 µM, respectively. Assays with tumor cell lines (HEK 293 and HCT-116) were carried out, and the derivative 4-(chloromethyl)-7,8-dihydroxy-2H-chromen-2-one (2c) was the most promising, with an IC50 value of 8.47 µM and a selectivity index of 1.87. In addition, the derivatives were evaluated against Saccharomyces cerevisiae strains that report about common modes of actions, including DNA damage, that are expected for agents that cause replicative stress. The coumarin derivatives 7-(2-(oxiran-2-yl)ethoxy)-2H-chromen-2-one (5b) and 7-(3-(oxiran-2-yl)propoxy)-2H-chromen-2-one (5c) caused DNA damage in S. cerevisiae. The O-alkenylepoxy group stands out as that with the most important functionality within this family of 35 derivatives, presenting a very good profile as an antiproliferative scaffold. Finally, the in vitro antiretroviral capacity was tested through RT-PCR assays. Derivative 5c showed inhibitory activity below 150 µM with an IC50 value of 134.22 ± 2.37 µM, highlighting the O-butylepoxy group as the functionalization responsible for the activity.

Parkinson's disease-linked V15A mutation facilitates α-synuclein aggregation by reducing membrane affinity.

Parkinson's disease can manifest either as a sporadic form, which is common, or as an inherited autosomal dominant trait resulting from missense mutations. Recently, the novel α-synuclein variant V15A was identified in two Caucasian and two Japanese families with Parkinson's disease. Using a combination of NMR spectroscopy, membrane binding assays and aggregation assays we show that the V15A mutation does not strongly perturb the conformational ensemble of monomeric α-synuclein in solution, but weakens its affinity for membranes. Attenuated membrane binding raises the concentration of the aggregation-prone disordered α-synuclein in solution, allowing only the V15A variant but not wild-type α-synuclein to form amyloid fibrils in the presence of liposomes. These findings, together with earlier research on other missense mutations of α-synuclein, suggest that maintaining a balance between membrane-bound and free aggregation-competent α-synuclein is critical in α-synucleinopathies.

New mescaline-related N-acylhydrazone and its unsubstituted benzoyl derivative: Promising metallophores for copper-associated deleterious effects relief in Alzheimer's disease.

Alzheimer's disease (AD) is related to the presence of extracellular aggregated amyloid-ß peptide (Aß), which binds copper(II) with high affinity in its N-terminal region. In this sense, two new 1-methylimidazole-containing N-acylhydrazonic metallophores, namely, X1TMP and X1Benz, were synthesized as hydrochlorides and characterized. The compound X1TMP contains the 3,4,5-trimethoxybenzoyl moiety present in the structure of mescaline, a natural hallucinogenic protoalkaloid that occurs in some species of cacti. Single crystals of X1Benz, the unsubstituted derivative of X1TMP, were obtained. The experimental partition coefficients of both compounds were determined, as well as their apparent affinity for Cu2+ in aqueous solution. Ascorbate consumption assays showed that these N-acylhydrazones are able to lessen the production of ROS by the Cu(Aß)-system, and a short-time scale aggregation study, measured through turbidity and confirmed by TEM images, revealed their capacity in preventing Aß fibrillation at equimolar conditions in the presence and absence of copper. 1H15N HSQC NMR experiments demonstrated a direct interaction between Aß and X1Benz, the most soluble of the compounds. The Cu2+ sequestering potential of this hydrazone towards Aß was explored by 1H NMR. Although increasing amounts of X1Benz were unexpectedly not efficient at removing the metal-induced perturbations in Aß backbone amides, the broadening effects observed on the compound's signals indicate the formation of a ternary Aß­copper-X1Benz species, which can be responsible for the observed ROS-lessening and aggregation-preventing activities. Overall, the N-acylhydrazones X1TMP and X1Benz have shown promising prospects as agents for the treatment of AD.

Trauma no accidental de columna toracolumbar en un niño de 10 meses / Non-accidental trauma to the thoracolumbar spine in a 10-month-old child

Presentamos el caso de un niño de 10 meses con fractura-subluxación inveterada de la columna toracolumbar, sin daño neurológico, a causa de un trauma no accidental por mecanismo desconocido. Para evaluar la estabilidad espinal se utilizó el sistema de clasificación de la gravedad de las lesiones toracolumbares de Vaccaro. Se realizó una osteosíntesis pedicular segmentaria. Se analizó y comparó el caso presentado con otros publicados. Se actualizaron los datos registrados por Unicef sobre violencia infantil en la República Argentina, no sin antes definir claramente el tema, el marco legal y realizar una sucinta reseña histórica. Nivel de Evidencia: IV

We present the case of a 10-month-old boy with a chronic thoracolumbar spine fracture-subluxation without neurological damage caused by an unknown mechanism of non-accidental trauma. To assess stability, we used the scoring system for thoracolumbar injuries according to Vaccaro et al. We performed a segmental pedicle osteosynthesis. We analyzed and compared our case with others in the available literature. We updated UNICEF data on child violence in Argentina, but not before clearly defining the subject, and the legal framework, and providing a brief historical review. Level of Evidence: IV

Aromaticity at position 39 in α-synuclein: A modulator of amyloid fibril assembly and membrane-bound conformations.

Recent studies revealed that molecular events related with the physiology and pathology of αS might be regulated by specific sequence motifs in the primary sequence of αS. The importance of individual residues in these motifs remains an important open avenue of investigation. In this work, we have addressed the structural details related to the amyloid fibril assembly and lipid-binding features of αS through the design of site-directed mutants at position 39 of the protein and their study by in vitro and in vivo assays. We demonstrated that aromaticity at position 39 of αS primary sequence influences strongly the aggregation properties and the membrane-bound conformations of the protein, molecular features that might have important repercussions for the function and dysfunction of αS. Considering that aggregation and membrane damage is an important driver of cellular toxicity in amyloid diseases, future work is needed to link our findings with studies based on toxicity and neuronal cell death. BRIEF STATEMENT OUTLINING SIGNIFICANCE: Modulation by distinct sequential motifs and specific residues of αS on its physiological and pathological states is an active area of research. Here, we demonstrated that aromaticity at position 39 of αS modulates the membrane-bound conformations of the protein, whereas removal of aromatic functionality at position 39 reduces strongly the amyloid assembly in vitro and in vivo. Our study provides new evidence for the modulation of molecular events related with the physiology and pathology of αS.

Molecular Dynamics-Assisted Interpretation of Experimentally Determined Intrinsically Disordered Protein Conformational Components: The Case of Human α-Synuclein.

Mass spectrometry and single molecule force microscopy are two experimental approaches able to provide structural information on intrinsically disordered proteins (IDPs). These techniques allow the dissection of conformational ensembles in their main components, although at a low-resolution level. In this work, we interpret the results emerging from these experimental approaches on human alpha synuclein (AS) by analyzing a previously published 73 µs-long molecular-dynamics (MD) simulation of the protein in explicit solvent. We further compare MD-based predictions of single molecule Förster resonance energy transfer (smFRET) data of AS in solution with experimental data. The combined theoretical and experimental data provide a description of AS main conformational ensemble, shedding light into its intramolecular interactions and overall structural compactness. This analysis could be easily transferred to other IDPs.

Long-term outcomes with the On-X bileaflet mitral valve: clinical events up to 17 years in 661 patients.

OBJECTIVES: This study reports long-term clinical outcomes-up to 17 years-among patients undergoing mitral valve replacement with the On-X bileaflet mechanical valve. Prior data regarding long-term outcomes with the On-X mitral valve have been limited. METHODS: This retrospective observational study included all patients who underwent mitral valve replacement with the On-X (Standard or Conform-X) valve at 2 major Spanish cardiac surgery centres between 2001 and 2018. The primary study end point was freedom from death. The secondary study end points included surgical mortality and freedom from any valve-related events. Data were obtained from an institutional database, medical records review, direct telephone interviews or the Spanish population registry. Statistical and Kaplan-Meier analyses were performed. RESULTS: A total of 661 patients (mean age 63.1 ± 10.9 years, 63% female) were followed for a mean of 5.6 years (range, 0-17.4 years). Survival at 5, 10 and 15 years was 85%, 71% and 63%, respectively. Surgical mortality was 7.3% (48/661). The linearized rate of global mortality was 1.3% patient-year. Freedom from reoperation was 97%, 95% and 92% at 5, 10 and 15 years, respectively; freedom from anticoagulation-related events was 94%, 89% and 89%, respectively. Multivariable analysis showed that mortality increased with total length of stay, age, smoking history, severe pulmonary hypertension and a permanent pacemaker. Patients who received the On-X 25 -mm valve had decreased long-term survival relative to patients who received other On-X valve sizes, possibly due to underlying risk factors. CONCLUSIONS: Patients in this study showed good long-term survival and freedom from valve-related events.

Times to endovascular treatment following two triage models.

INTRODUCTION: Debate is ongoing regarding the best service model for achieving a prompt recanalization in LVO ischemic stroke with an indication for thrombectomy. We aim to assess differences between two of the existing models within our region. METHODS: We work in a cluster of three public hospitals (one hub and two spokes) forming a single functional neurology service in Madrid (Spain). Upon a LVO case out of regular hours, the interventional neuroradiologist drives to the hub hospital following the drive-the-doctor paradigm (DD). For any of the spokes, the patient is transferred to the nearest endovascular-capable hospital (drip-and-ship-DS) following the Madrid Stroke Plan. We compared times to endovascular procedures between cases managed under each model. RESULTS: Thirty-eight patients in the period April 2014-March 2021 meet the inclusion criteria (DD 27; DS 11). While baseline characteristics are comparable between groups, we observed a notable difference in the time delays favoring those managed under the DD model; with differences between median times of 105 min for hospital arrival-groin puncture (DD 140 [110-181]; DS 245 [222-310], p 0.0004); 122 min for CT-groin puncture (DD 100 [85-144]; DS 222 [200-255], p = 0.0001); and 98 min for hospital arrival-recanalization (DD 180 [140-209]; DS 278 [241-360], p = 0.0014). No differences were observed for NIHSS or mRS on discharge. CONCLUSIONS: Compared to the drip-and-ship, the drive-the-doctor triage model for patients with LVO ischemic stroke in primary centers seems to guarantee a shorter time to the start of the endovascular procedure and to recanalization in our region.

Comparing the copper binding features of alpha and beta synucleins.

Amyloid aggregation of α-synuclein (AS) is one of the hallmarks of Parkinson's disease (PD). Copper ions specifically bind at the N-terminus of AS, accelerating protein aggregation. Its protein homolog ß-synuclein (BS) is also a copper binding protein, but it inhibits AS aggregation. Here, a comparative spectroscopic study of the Cu2+ binding properties of AS and BS has been performed, using electronic absorption, circular dichroism (CD) and electronic paramagnetic resonance (EPR). Our comparative spectroscopic study reveals striking similarities between the Cu2+ binding features of the two proteins. The Cu2+ binding site at the N-terminal group of BS protein, modeled by the BS (1-15) fragment is identical to that of AS; however, its rate of reduction is three times faster as compared to the AS site, consistent with BS having an additional Met residue in its Met1-Xn-Met5-Xn-Met10 motif. The latter is also evident in the cyclic voltammetry studies of the Cu-BS complex. On the other hand, the Cu2+ binding features of the His site in both proteins, as modeled by AS(45-55) and BS(60-70), are identical, indicating that the shift in the His position does not affect its coordination features. Finally, replacement of Glu46 by Ala does not alter Cu2+ binding to the His site, suggesting that the familial PD E46K mutation would not impact copper-induced aggregation. While further studies of the redox activity of copper bound to His50 in AS are required to understand the role of this site in metal-mediated aggregation, our study contributes to a better understanding of the bioinorganic chemistry of PD.

Membrane-based conceptual design of reuse water production from candy factory wastewater.

Intense pressure on water resources has led to efforts to reuse reclaimed processing wastewater in the food industry. There are tight rules for water quality, but efficient separation technologies such as reverse osmosis possess good possibilities for water reuse. This study developed a membrane-based reuse water concept for wastewater from the candy industry emphasizing the pre-treatment stage in the concept to reduce fouling. The wastewater contained suspended solids, sugar compounds and the ingredients for candy gelation, which had a tendency to foul membranes, making pre-treatment essential for a successful concept. Cross-rotational ultrafiltration, which featured enhanced fouling prevention for membranes, functioned well for the removal of challenging substances. Conventional filtration technologies were impractical due to a low flux, even when the viscosity of the wastewater was reduced using surfactants. The wastewater had a high chemical oxygen demand, meaning that there was a strong fouling potential for reverse osmosis membranes, but also high osmotic pressure. A spiral wound reverse osmosis functioned well when the wastewater was pre-treated, and it produced good quality water with respect to all the other studied parameters except the chemical oxygen demand. However, chemical oxygen demand rejection was 99% since the concentration in the wastewater was originally very high.

Treatment of Intracranial Aneurysms Using the New Silk Vista Flow Diverter: Safety Outcomes at Short-Term Follow-Up.

Background: Flow diverters are widely used as the first endovascular treatment option for complex brain aneurysms due to their high percentage of occlusion and low morbi-mortality. The Silk Vista device is a new generation of flow diverters designed to facilitate full visibility, improve apposition to the vessel wall, and enhance navigability. Indeed, its greatest advantage is that it enables the easier navigation of stents between 3.5 and 4.75 mm through a 0.021 microcatheter. The objective of this study was to evaluate the safety and effectiveness of Silk Vista systems for treating cerebral aneurysms. Methods: This prospective observational study included 25 consecutive patients with 27 wide-necked unruptured aneurysms treated with SILK Vista who were retrospectively analyzed for safety and efficacy. Results: Endovascular treatment was successfully performed in all patients. The final morbidity and mortality rates were both 0.0%. Short-term (3-5 months) angiographic follow-up revealed 21 complete occlusions and 6 near-complete occlusions. No significant parent artery stenosis was observed. Conclusions: This report demonstrates the efficacy of Silk Vista in treating brain aneurysms, although longer experiences should be carried out to confirm our results.

Verbascoside, synthetic derivatives and other glycosides from Argentinian native plant species as potential antitumoral agents.

A phytochemical study was performed on three native plant species from the central-western zone of Argentina: Buddleja cordobensis Grisebach, Baccharis salicina Torr. & A. Gray and Nepeta cataria L. We could obtain verbascoside (1) from B. cordobensis. From N. cataria, we could obtain 1, 5, 9-epi-deoxyloganic acid (2) L. Finally, we could isolate 2-ß-(L-rhamnopyranosyl)-3-angeloyloxy-15-acetyloxy-7,13(14)-E-dien-ent-labdane (3) and 2-ß-(L-rhamnopyranosyl)-3-α-angeloyloxy-15-hydroxy-7,13(14)-E-dien-ent-labdane (4) from B. salicina. Moreover, three derivatives from 1, and one semi-synthetic derivative from 2, were prepared. PCR reaction was used to analyse the activity against DNA polymerase and cell culture to determine cytotoxicity and antitumoral activity. Verbascoside (1) was strongly active in the nanomolar scale (IC50 = 356 nM) against DNA polymerization. Moreover, verbascoside was also strongly active in the nanomolar scale against human melanoma cell line (IC50 = 256 nM) and human colorectal cell line (IC50 = 320 nM). Furthermore, derivatives 6 and 7 were cytotoxic against both cancer cell lines.

Evaluación de competencias clínicas y quirúrgicas de una Residencia de Ortopedia y Traumatología Infantil. Utilización del Mini-CEX (Mini-Clinical Evaluation Exercise) y del DOPS (Direct Observation of Procedural Skills) / Evaluation of clinical and surgical proficiency at a residency of child orthopedics and traumatology Use of the Mini-CEX (Mini-Clinical Evaluation Exercise) and DOPS (Direct Observation of Procedural Skills)

Objetivo: Evaluar competencias profesionales de una residencia de Ortopedia y Traumatología Infantil. Instrumentos pedagógicos utilizados: Mini-Clinical Evaluation Exercise (Mini-CEX)y Direct Observation of Procedural Skills (DOPS)para competencias clínicas y quirúrgicas, respectivamente. Ambas evalúan la cúspide de la pirámide de Miller; se precisaron su confiabilidad y validez.materiales y métodos: Estudio observacional prospectivo de una cohorte de seis residentes de primero, segundo y tercer año quienes fueron evaluados por seis docentes en diversos contextos y situaciones reales: consultorio externo y de guardia, sala de internación, interconsultas, quirófano y sala de yesos. Resultados: Se realizaron 65 observaciones. Cada residente fue evaluado como media en 10 oportunidades por entre 3 y 6 docentes. Para las variables clínicas, en general, los residentes más antiguos obtuvieron valores sobresalientes y los residentes de primer año, valores satisfactorios. No hubo diferencias significativas para las competencias quirúrgicas globalmente, pero los residentes de tercer año fueron más competentes para resolver situaciones inesperadas. El coeficiente de Cronbach fue superior a 0,90. Conclusiones: Ambos instrumentos de evaluación tuvieron una elevada confiabilidad. El método estadístico permitió individualizar exactamente las fragilidades y fortalezas de la residencia. El coeficiente de Cronbach obtuvo un valor de alto impacto psicométrico. Nivel de Evidencia: IV

Purpose: To assess professional competencies in a Pediatric Orthopedic and Traumatology Residency Program by the implementation of two performance-assessment instruments: Mini-Clinical Evaluation Exercise (Mini-CEX) and Direct Observation of Procedural Skills (DOPS) for clinical and surgical skills. Both tools aim to assess the top of Miller's pyramid, for its reliability and validity. Materials and Methods: Prospective observational cohort study of six medical trainees in the first, second and third year of their residency program (R1-R2-R3) who were randomly assessed by six examiners during their daily training at outpatient clinics, emergency room, inpatients unit, operating room, and plaster room. The statistical analysis was carried out with the Chi-Square and Wilcoxon-Rank paired test for univariate variables. The residents' relationship cohorts were compared using the Kruskal-Wallis test. The reliability of the methodological tool was determined by the psychometric test of Crombach. Alfa was set at ≤ 0.05. Diagnostic study: level IV. Results: We performed 65 assessments. Each resident was evaluated 10 times on average by 3 to 6 examiners. The oldest residents had better performances in overall clinical competencies. However, the R1 group achieved satisfactory results whereas the R2-R3 groups had the most outstanding scores. There were no statistical differences in general surgical competencies, but the R3 group was outstanding in cases of unforeseen surgical situations. The Alfa Crombach coefficient was over 0.90. Conclusion: The Mini-CEX, DOPS, and interactive feedback were powerful tools to provide high-quality assessment and were widely accepted by residents and examiners. The statistical analysis allowed us to identify the weaknesses and strengths of the trainees. The Crombach coefficient had a high psychometric impact. Level of Evidence: IV

Role of Tyr-39 for the Structural Features of α-Synuclein and for the Interaction with a Strong Modulator of Its Amyloid Assembly.

Recent studies suggest that Tyr-39 might play a critical role for both the normal function and the pathological dysfunction of α-synuclein (αS), an intrinsically disordered protein involved in Parkinson's disease. We perform here a comparative analysis between the structural features of human αS and its Y39A, Y39F, and Y39L variants. By the combined application of site-directed mutagenesis, biophysical techniques, and enhanced sampling molecular simulations, we show that removing aromatic functionality at position 39 of monomeric αS leads to protein variants populating more compact conformations, conserving its disordered nature and secondary structure propensities. Contrasting with the subtle changes induced by mutations on the protein structure, removing aromaticity at position 39 impacts strongly on the interaction of αS with the potent amyloid inhibitor phthalocyanine tetrasulfonate (PcTS). Our findings further support the role of Tyr-39 in forming essential inter and intramolecular contacts that might have important repercussions for the function and the dysfunction of αS.

X1INH, an improved next-generation affinity-optimized hydrazonic ligand, attenuates abnormal copper(I)/copper(II)-α-Syn interactions and affects protein aggregation in a cellular model of synucleinopathy.

Although normal aging presents an accumulation of copper and iron in the brain, this becomes more relevant in neurodegeneration. α-Synuclein (α-Syn) misfolding has long been linked with the development of Parkinson's disease (PD). Copper binding promotes aggregation of α-Syn, as well as generalized oxidative stress. In this sense, the use of therapies that target metal dyshomeostasis has been in focus in the past years. Metal-Protein Attenuating Compounds (MPACs) are moderate chelators that aim at disrupting specific, abnormal metal-protein interactions. Our research group has now established that N-acylhydrazones compose a set of truly encouraging MPACs for the bioinorganic management of metal-enhanced aggregopathies. In the present work, a novel ligand, namely 1-methyl-1H-imidazole-2-carboxaldehyde isonicotinoyl hydrazone (X1INH), is reported. We describe solution studies on the interaction and affinity of this compound for copper(ii) ions showing that a fine tuning of metal-affinity was achieved. A series of in vitro biophysical NMR experiments were performed in order to assess the X1INH ability to compete with α-Syn monomers for the binding of both copper(i) and copper(ii) ions, which are central in PD pathology. A preference for copper(i) has been observed. X1INH is less toxic to human neuroglioma (H4) cells in comparison to structure-related compounds. Finally, we show that treatment with X1INH results in a higher number of smaller, less compact inclusions in a well-established model of α-Syn aggregation. Thus, X1INH constitutes a promising MPAC for the treatment of Parkinson's disease.

Molecular characterization of an aggregation-prone variant of alpha-synuclein used to model synucleinopathies.

The misfolding and aggregation of alpha-synuclein (aSyn) are thought to be central events in synucleinopathies. The physiological function of aSyn has been related to vesicle binding and trafficking, but the precise molecular mechanisms leading to aSyn pathogenicity are still obscure. In cell models, aSyn does not readily aggregate, even upon overexpression. Therefore, cellular models that enable the study of aSyn aggregation are essential tools for our understanding of the molecular mechanisms that govern such processes. Here, we investigated the structural features of SynT, an artificial variant of aSyn that has been widely used as a model of aggregation in mammalian cell systems, since it is more prone to aggregation than aSyn. Using Nuclear Magnetic Resonance (NMR) spectroscopy we performed a detailed structural characterization of SynT through a systematic comparison with normal, unmodified aSyn. Interestingly, we found that the conformations adopted by SynT resemble those described for the unmodified protein, demonstrating the usefulness of SynT as a model for aSyn aggregation. However, subtle differences were observed at the N-terminal region involving transient intra and/or intermolecular interactions that are known to regulate aSyn aggregation. Importantly, our results indicate that disturbances in the N-terminal region of SynT, and the consequent decrease in membrane binding of the modified protein, might contribute to the observed aggregation behavior of aSyn, and validate the use of SynT, one of the few models of aSyn aggregation in cultured cells.