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Amyotrophic lateral sclerosis (ALS) is a multifactorial neurodegenerative pathology of the upper or lower motor neuron. Evaluation of ALS progression is based on clinical outcomes considering the impairment of body sites. ALS has been extensively investigated in the pathogenetic mechanisms and the clinical profile; however, no molecular biomarkers are used as diagnostic criteria to establish the ALS pathological staging. Using the source-reconstructed magnetoencephalography (MEG) approach, we demonstrated that global brain hyperconnectivity is associated with early and advanced clinical ALS stages. Using nuclear magnetic resonance (1H-NMR) and high resolution mass spectrometry (HRMS) spectroscopy, here we studied the metabolomic profile of ALS patients’ sera characterized by different stages of disease progression—namely early and advanced. Multivariate statistical analysis of the data integrated with the network analysis indicates that metabolites related to energy deficit, abnormal concentrations of neurotoxic metabolites and metabolites related to neurotransmitter production are pathognomonic of ALS in the advanced stage. Furthermore, analysis of the lipidomic profile indicates that advanced ALS patients report significant alteration of phosphocholine (PCs), lysophosphatidylcholine (LPCs), and sphingomyelin (SMs) metabolism, consistent with the exigency of lipid remodeling to repair advanced neuronal degeneration and inflammation.

Alzheimer’s disease is a neurodegenerative disease characterized by the formation of amyloid plaques constituted prevalently by amyloid peptides. Due to the well-known challenges related to the study in solution of these peptides, several membrane-mimicking systems such as micelle constituted by detergent—i.e., DPC and SDS—have been deeply investigated. Additionally, the strategy of studying short fragments instead of the full-length peptide turned out to be advantageous in exploring the structural properties of the different moieties in Aβ in order to reproduce its pathologic effects. Several studies reveal that among Aβ fragments, Aβ(25−35) is the shortest fragment able to reproduce the aggregation process. To enrich the structural data currently available, in the present work we decided to evaluate the conformational changes adopted by Aβ(25−35) in SDS combining CD and NMR spectroscopies at different times. From the solved structures, it emerges that Aβ(25−35) passes from an unordered conformation at the time of the constitution of the system to a more ordered and energetically favorable secondary structure at day 7, which is kept for 2 weeks. These preliminary data suggest that a relatively long time affects the kinetic in the aggregation process of Aβ(25−35) in a micellar system, favoring the stabilization and the formation of a soluble helix conformation.

Alzheimer’s disease (AD) is a neurodegenerative pathology characterized by the presence of neurofibrillary tangles and amyloid plaques, the latter mainly composed of Aβ(1–40) and Aβ(1–42) peptides. The control of the Aβ aggregation process as a therapeutic strategy for AD has prompted the interest to investigate the conformation of the Aβ peptides, taking advantage of computational and experimental techniques. Mixtures composed of systematically different proportions of HFIP and water have been used to monitor, by NMR, the conformational transition of the Aβ(1–42) from soluble α-helical structure to β-sheet aggregates. In the previous studies, 50/50 HFIP/water proportion emerged as the solution condition where the first evident Aβ(1–42) conformational changes occur. In the hypothesis that this solvent reproduces the best condition to catch transitional helical-β-sheet Aβ(1–42) conformations, in this study, we report an extensive NMR conformational analysis of Aβ(1–42) in 50/50 HFIP/water v/v. Aβ(1–42) structure was solved by us, giving evidence that the evolution of Aβ(1–42) peptide from helical to the β-sheet may follow unexpected routes. Molecular dynamics simulations confirm that the structural model we calculated represents a starting condition for amyloid fibrils formation.

Alzheimer's disease (AD), is the most common neurodegenerative disorder of the aging population resulting in progressive cognitive and functional decline. Accumulation of amyloid plaques around neuronal cells is considered a critical pathogenetic event and, in most cases, a hallmark of the pathology. In the attempt to identify anti-AD drug candidates, hundreds of molecules targeting Aβ peptides have been screened. Peptide molecules have been widely explored, appreciating chemical stability, biocompatibility, and low production cost. More recently, many anti-Aβ(1-42) monoclonal antibodies have been developed, given the excellent potential of immunotherapy for treating or preventing AD. Antibodies are versatile ligands that bind a large variety of molecules with high affinity and specificity; however, their extensive therapeutic application is complex and requires huge economic investments. Novel approaches to identify alternative antibody formats are considered with great interest. In this context, taking advantage of the favorable peptide properties and the availability of Aβ-antibodies structural data, we followed an innovative research approach to identify short peptide sequences on the model of the binding sites of Aβ(1-42)/antibodies. WAibH and SYSTPGK were designed as mimics of solanezumab and aducanumab, respectively. Circular dichroism and nuclear magnetic resonance analysis reveal that the antibody-derived peptides interact with Aβ(1-42) in the soluble monomeric form. Moreover, AFM microscopy imaging shows that WAibH and SYSTPGK are capable of controlling the Aβ(1-42) aggregation. The strategy to identify WAibH and SYSTPGK is innovative and can be widely applied for new anti-Aβ antibody mimicking peptides.

d-Amino acids were believed to occur only in bacteria and invertebrates. Today, it is well known that d-amino acids are also present in mammalian tissues in a considerable amount. In particular, high levels of free d-serine (d-Ser) and d-aspartate (d-Asp) are found in the brain. While the functions of d-Ser are well known, many questions remain unanswered regarding the role of d-Asp in the central nervous system. d-Asp is very abundant at the embryonic stage, while it strongly decreases after birth because of the expression of d-aspartate oxidase (Ddo) enzyme, which catalyzes the oxidation of this d-amino acid into oxaloacetate, ammonium, and hydrogen peroxide. Pharmacologically, d-Asp acts as an endogenous agonist of N-methyl d-aspartate and mGlu5 receptors, which are known to control fundamental brain processes, including brain development, synaptic plasticity, and cognition. In this work, we studied a recently generated knockin mouse model (R26ddo/ddo), which was designed to express DDO beginning at the zygotic stage. This strategy enables d-Asp to be almost eliminated in both prenatal and postnatal lives. To understand which biochemical pathways are affected by depletion of d-Asp, in this study, we carried out a metabolomic and lipidomic study of ddo knockin brains at different stages of embryonic and postnatal development, combining nuclear magnetic resonance (NMR) and high-resolution mass spectrometry (HRMS) techniques. Our study shows that d-Asp deficiency in the brain influences amino acid pathways such as threonine, glycine, alanine, valine, and glutamate. Interestingly, d-Asp is also correlated with metabolites involved in brain development and functions such as choline, creatine, phosphocholine (PCho), glycerophosphocholine (GPCho), sphingolipids, and glycerophospholipids, as well as metabolites involved in brain energy metabolism, such as GPCho, glucose, and lactate.

SARS-CoV-2 is a virus belonging to the betacoronavirus family, causing fatal respiratory disease in humans, which became pandemic in 2020. Italy is one of the most affected countries by COVID-19, particularly in the northern regions. Several studies consider COVID-19 a zoonotic disease and, since Italy is the repository of a high biodiversity, SARS-CoV-2 infection in animals can be considered as a reservoir of the virus or favor the spreading between animals and humans. In this work, we analyzed the amino acid sequences of ACE2 protein of the most common domestic and wild animals present in Italy. Among the latter, we focused on ACE2 of the Chiroptera species present in Italy to identify the primary reservoir in this region. First, we reproduced in silico the Chiroptera ACE2/viral spike (S) protein interactions on the human ACE2/SARS-CoV-2 S complex model and identified the critical residues for the binding. In silico molecular docking of ACE2 belonging to Chiroptera vs SARS-CoV-2 S protein pointed to Rhinolophus ferrumequinum as a bat living in Italy, that may be a potential primary reservoir of the virus. On the other hand, a sequence similarity search on ACE2 of domestic and wild animals living in Italy pointed to domestic (horses, cats, cattle and sheep) and wild (European rabbits and grizzly bears) animal species as potential SARS-CoV-2 secondary reservoirs. Molecular docking of ACE2 belonging to these species vs S protein of Bat coronavirus (Bt-CoV/Rp3/2004) suggests that the primary reservoir Rhinolophus ferrumequinum may infect the secondary reservoirs, domestic and worldwide animals living in Italy, determining a specific risk of SARS-CoV-2 infection., Bioinformatics; Virology; SARS-CoV-2; COVID-19; Italian biodiversity; molecular docking and dynamics; sequence alignment; host range prediction.