Amyotrophic lateral sclerosis (ALS) is a progressive adult-onset neurodegenerative disease, that affects cortical, bulbar and spinal motor neurons, and it is considered a proteinopathy, in which pathological proteins (SOD1, TDP-43, and FUS) may accumulate and interfere with neuronal functions eventually leading to cell death. These proteins can be released from cells and transported in the body fluids by extracellular vesicles (EVs). EVs are spherical vesicles, which are classified mainly in microvesicles (MVs) and exosomes (EXOs) based on their biogenesis, size and surface markers. In this study we characterized MVs and EXOs isolated from plasma of sporadic ALS patients and healthy controls and determined their number, size and SOD1, TDP-43, and FUS protein composition. No variation was found in the number of EVs between ALS patients and controls. However, the mean size both for MVs and for EXOs resulted increased in ALS patients compared to controls. MVs derived from ALS patients were enriched in SOD1, TDP-43, phospho-TDP-43, and FUS proteins compared to CTRLs. SOD1 was generally more concentrated in EXOs than in MVs, while TDP-43 and FUS protein levels were slightly higher in MVs than in EXOs. We demonstrated that MVs and EXOs size were increased in ALS patients compared to controls and that MVs of ALS patients were enriched with toxic proteins compared to CTRLs. EXOs did not show any protein changes. These data may suggest that MVs can transport toxic proteins and might play a role in prion-like propagation of ALS disease.

In 1993, Rosen and collaborators discovered that the gene encoding SOD1 has mutations in amyotrophic lateral sclerosis (ALS) patients; moreover, these mutations are found in the exon regions, suggesting that their toxic effects are the consequence of protein dysfunction with an increase of oxidative stress. While a clear genetic picture has been delineated, a more complex scenario has been ascribed to the SOD1 protein. On the one hand, some evidence sustains the hypothesis of an additionally toxic role for wild-type SOD1 (WT-SOD1) in the pathogenesis of sporadic ALS. On the other hand, our group identified a discrepancy among WT-SOD1 protein expression levels and mRNA in ALS sporadic patients, thus providing the hypothesis of a re-localization of the “missing” SOD1 in a different sub-cellular compartment, i.e., nucleus, or an aggregation/precipitation in the insoluble fraction. Moreover, our data also indicate an association between longer disease duration and higher amounts of soluble SOD1 within the nucleus, suggesting a possible defensive role of the protein in this compartment. Starting from this evidence, in this review we will attempt to resolve the “ambivalent” behavior of SOD1 in ALS disease and we will try to classify sporadic ALS patients according to a novel biological signature, i.e., SOD localization.

Oxidative stress (OS) and inflammation are two important and well-studied pathological hallmarks of neurodegenerative diseases (NDDs). Due to elevated oxygen consumption, the high presence of easily oxidizable polyunsaturated fatty acids and the weak antioxidant defenses, the brain is particularly vulnerable to oxidative injury. Uncertainty exists over whether these deficits contribute to the development of NDDs or are solely a consequence of neuronal degeneration. Furthermore, these two pathological hallmarks are linked, and it is known that OS can affect the inflammatory response. In this review, we will overview the last findings about these two pathways in the principal NDDs. Moreover, we will focus more in depth on amyotrophic lateral sclerosis (ALS) to understand how anti-inflammatory and antioxidants drugs have been used for the treatment of this still incurable motor neuron (MN) disease. Finally, we will analyze the principal past and actual clinical trials and the future perspectives in the study of these two pathological mechanisms.

Alteration in RNA metabolism, concerning both coding and long non-coding RNAs (lncRNAs), may play an important role in Amyotrophic Lateral Sclerosis (ALS) pathogenesis. In this work, we performed a whole transcriptome RNA-seq analysis to investigate the regulation of non-coding and coding RNAs in Sporadic ALS patients (SALS), mutated ALS patients (FUS, TARDBP and SOD1) and matched controls in Peripheral Blood Mononuclear Cells (PBMC). Selected transcripts were validated in spinal cord tissues. A total of 293 differentially expressed (DE) lncRNAs was found in SALS patients, whereas a limited amount of lncRNAs was deregulated in mutated patients. A total of 87 mRNAs was differentially expressed in SALS patients; affected genes showed an association with transcription regulation, immunity and apoptosis pathways. Taken together our data highlighted the importance of extending the knowledge on transcriptomic molecular alterations and on the significance of regulatory lncRNAs classes in the understanding of ALS disease. Our data brought the light on the importance of lncRNAs and mRNAs regulation in central and peripheral systems, offering starting points for new investigations about pathogenic mechanism involved in ALS disease.

Identifying biomarkers is essential for early diagnosis of neurodegenerative diseases (NDs). Large (LEVs) and small extracellular vesicles (SEVs) are extracellular vesicles (EVs) of different sizes and biological functions transported in blood and they may be valid biomarkers for NDs. The aim of our study was to investigate common and different miRNA signatures in plasma derived LEVs and SEVs of Alzheimer’s disease (AD), Parkinson’s disease (PD), Amyotrophic Lateral Sclerosis (ALS) and Fronto-Temporal Dementia (FTD) patients. LEVs and SEVs were isolated from plasma of patients and healthy volunteers (CTR) by filtration and differential centrifugation and RNA was extracted. Small RNAs libraries were carried out by Next Generation Sequencing (NGS). MiRNAs discriminate all NDs diseases from CTRs and they can provide a signature for each NDs. Common enriched pathways for SEVs were instead linked to ubiquitin mediated proteolysis and Toll-like receptor signaling pathways and for LEVs to neurotrophin signaling and Glycosphingolipid biosynthesis pathway. LEVs and SEVs are involved in different pathways and this might give a specificity to their role in the spreading of the disease. The study of common and different miRNAs transported by LEVs and SEVs can be of great interest for biomarker discovery and for pathogenesis studies in neurodegeneration.