Extracellular Vesicles Involvement in the Modulation of the Glioblastoma Environment.

Glioblastoma (GBM) is the most deadly primary brain tumour and is a paradigmatic example of heterogeneous cancer. Although expanding data propose the phenotypic plasticity exhibited by glioblastoma cells, as a critical feature involved in the tumour development and posttherapy recurrence, the central machinery responsible for their aggressiveness remains elusive. Despite decades of research, the complex biology of the glioblastoma is still unknown. Progress in genetic and epigenetic discoveries has improved diagnostic classification, prognostic information, and therapeutic planning. In the complex model of intercellular signalling, several studies have shown that extracellular vesicles have a key role in the intercellular communication among GBM cells and the tumour microenvironment modulation. The purpose of this review is to summarize the role of the EV-mediated intercellular crosstalk in the glioblastoma physiopathology.

Neurodegenerative diseases as proteinopathies-driven immune disorders.

In the pathophysiology of neurodegenerative disorders, the role of misfolded protein deposition leading to neurodegeneration has been primarily discussed. In the last decade, however, it has been proposed a parallel involvement of innate immune activation, chronic inflammation and adaptive immunity in the neurodegeneration mechanisms triggered by proteinopathies. New insights in the neurodegenerative field strongly suggest a role for the immune system in the pathophysiology of neurodegenerative disorders. Therefore, the hypothesis underlining the modulation of the innate and the adaptive immune system in the events linked to brain deposition of misfolded proteins could open new perspectives in the setting of specific immunotherapeutic strategies for the treatment of neurodegenerative diseases. Therefore, we have reviewed the pathogenic hypothesis in neurodegenerative pathologies, underling the links between the deposition of misfolded protein mechanisms and the immune activation.

Proteomics characterization of extracellular vesicles sorted by flow cytometry reveals a disease-specific molecular cross-talk from cerebrospinal fluid and tears in multiple sclerosis.

Several proteomics studies have been conducted to identify new cerebrospinal fluid (CSF) biomarkers in Multiple Sclerosis (MuS). However, the complexity of CSF and its invasive collection, limits its use. Therefore, the goal of biomarker research in MuS is to identify novel distinctive targets in CSF or in easily accessible biofluids. Tears represent an interesting matrix for this purpose, because (1) tears are related to the central nervous system (CNS) and (2) the CNS contains Extracellular Vesicles (EVs) derived from brain cells. These EVs are emerging new biomarkers associated to several neurological disorders. Here we applied an optimized flow cytometer for the identification and subtyping of EVs from CSF and tears. We found, for the first time, microglia-derived and neural-derived EVs in tears. The flow cytometer was used to sort and purify 106 EVs from untouched CSF and tears of MuS patients and healthy subjects. Purified EVs were analyzed with shotgun proteomics analysis, revealing that EVs from both CSF and tears of MuS patients conveyed similar proteins. Our data demonstrated a specific EVs-mediated molecular cross talk between CSF and tears, which opens the door to new diagnostic perspectives for MuS. Data are available via ProteomeXchange with identifier PXD013794. SIGNIFICANCE: Proteomics characterization of released Extracellular Vesicles (EVs) in CSF and tears of Multiple Sclerosis patients represents a pioneering application that helped in recognizing information about the biologically relevant molecules. We found, for the first time, microglia-derived and neural-derived EVs in tears. Moreover, purified EVs revealed that both CSF and tears of Multiple Sclerosis patients conveyed similar proteins involved in inflammation, angiogenesis and immune response signalling. We think that our data will contribute to enhance knowledge in Multiple Sclerosis mechanisms and help in biomarker discovery. Moreover tears represent one of the most convenient body fluid for biomarker discovery in Multiple Sclerosis, since it is an high informative and easy accessible. The opportunity to export such a platform to a territory monitoring plan opens the door to new diagnostic perspectives for Multiple Sclerosis.

The Link Among Neurological Diseases: Extracellular Vesicles as a Possible Brain Injury Footprint.

Extracellular vesicles (EVs), referred as membranous vesicles released into body fluids from all cell types, represent a novel model to explain some aspects of the inter-cellular cross talk. It has been demonstrated that the EVs modify the phenotype of target cells, acting through a large spectrum of mechanisms. In the central nervous system, the EVs are responsible of the wide range of physiological processes required for normal brain function and neuronal support, such as immune signaling, cellular proliferation, differentiation, and senescence. Growing evidences link the EV functions to the pathogenic machinery of the neurological diseases, contributing to the disease progression and spreading. Extracellular vesicles are involved in the brain injury by multimodal ways; they propagate inflammation across the blood brain barrier (BBB), mediate neuroprotection and modulate regenerative processes. For these reasons, extracellular vesicles represent a promising biomarker in neurological disorders as well as an interesting starting point for the development of novel therapeutic strategies. Herein, we review the role of the EVs in the pathogenesis of neurological disease, discussing their potential clinical applications.

The Characterization of Regulatory T-Cell Profiles in Alzheimer's Disease and Multiple Sclerosis.

Regulatory T Cells (Tregs) are a T-lymphocyte subset involved in the maintenance of immune peripheral tolerance. Despite evidence of the adaptive immune system's role in Alzheimer's Disease (AD), the involvement of Tregs is still not clear. We focused on the Flow-Cytometry analysis of the Treg frequencies and phenotypes in the AD. The aim of the study is to analyse similarities and differences in Tregs profile between Alzheimer's Disease and Multiple Sclerosis. Regulatory T Cells (CD4+/CD25high/CD127low-neg) were identified using an innovative Flow Cytometry method and subtyped as Resting (analysed CD45RApos/CD25dim), Activated (CD45RAneg/CD25bright) and Secreting (CD45RAneg/CD25dim) cells. Our data demonstrate a significant decrease in the total and Resting Tregs in AD patients when compared to healthy subjects. The percentage of the results of the Resting Tregs were also reduced in MS patients together with a parallel frequency increase of Activated Tregs. Our data suggest that altered Treg phenotypes observed in both diseases could play a role in the impairment of the Treg-mediated immunological tolerance, recalling a possible link between the two pathologies. Given that this study was conducted on a restricted population, if confirmed by a further and enlarged study, the implications of the autoimmune mechanisms in AD pathophysiology could open new immunotherapeutic perspectives based on Treg modulation.

PDCD10 gene mutations in multiple cerebral cavernous malformations.

Cerebral cavernous malformations (CCMs) are vascular abnormalities that may cause seizures, intracerebral haemorrhages, and focal neurological deficits. Familial form shows an autosomal dominant pattern of inheritance with incomplete penetrance and variable clinical expression. Three genes have been identified causing familial CCM: KRIT1/CCM1, MGC4607/CCM2, and PDCD10/CCM3. Aim of this study is to report additional PDCD10/CCM3 families poorly described so far which account for 10-15% of hereditary cerebral cavernous malformations. Our group investigated 87 consecutive Italian affected individuals (i.e. positive Magnetic Resonance Imaging) with multiple/familial CCM through direct sequencing and Multiplex Ligation-Dependent Probe Amplification (MLPA) analysis. We identified mutations in over 97.7% of cases, and PDCD10/CCM3 accounts for 13.1%. PDCD10/CCM3 molecular screening revealed four already known mutations and four novel ones. The mutated patients show an earlier onset of clinical manifestations as compared to CCM1/CCM2 mutated patients. The study of further families carrying mutations in PDCD10/CCM3 may help define a possible correlation between genotype and phenotype; an accurate clinical follow up of the subjects would help define more precisely whether mutations in PDCD10/CCM3 lead to a characteristic phenotype.

Acetyl-L-carnitine: from a biological curiosity to a drug for the peripheral nervous system and beyond.

Acetyl-L-carnitine (ALC) is a molecule derived from acetylation of carnitine in the mitochondria. Carnitine acetylation enables the function of CoA and facilitates elimination of oxidative products. Beyond this metabolic activity, ALC provides acetyl groups for acetylcholine synthesis, exerts a cholinergic effect and optimizes the balance of energy processes. Acetylcarnitine supplementation induces neuroprotective, neurotrophic and analgesic effects in the peripheral nervous system. In the recent studies, ALC, by acting as a donor of acetyl groups to NF-kb p65/RelA, enhanced the transcription of the GRM2 gene encoding the mGLU2 receptors, inducing long-term upregulation of the mGluR2, evidencing therefore that its long-term analgesic effects are dependent on epigenetic modifications. Several studies, including double-blind, placebo-controlled, parallel group studies and few open studies showed the effect of ALC in diseases characterized by neuropathies and neuropathic pain: the studies included diabetic neuropathy, HIV and antiretroviral therapy-induced neuropathies, neuropathies due to compression and chemotherapeutic agents. Double-blinded studies involved 1773 patients. Statistical evaluations evidenced reduction of pain, improvements of nerve function and trophism. In conclusion, ALC represents a consistent therapeutic option for peripheral neuropathies, and its complex effects, neurotrophic and analgesic, based on epigenetic mechanism, open new pathways in the study of peripheral nerve disease management.

Amyloid-specific T-cells differentiate Alzheimer's disease from Lewy body dementia.

Alzheimer's disease and dementia with Lewy bodies are the most common neurodegenerative dementias in old age. Accurate diagnosis of these conditions has important clinical implications because they tend to be confounded. In the brain of Alzheimer's disease patients amyloid-beta is produced in excess and deposited as plaques, forming the hallmark of this condition. Lymphocytes have been implicated in the process of amyloid-beta removal and inflammation occurrence. Here we investigated peripheral amyloid-beta1-42-specific T-cells by multicolor flow cytometry to simultaneously detect and characterize activation markers and cell signaling proteins (phospho-protein kinase C) in patients with Alzheimer's disease or Lewy body dementia and in healthy controls. Results indicate that only Alzheimer's disease patients display small subsets of peripheral amyloid-beta1-42-specific T-cells, characterized by bright expression of phosphorylated-protein kinase C-delta or -zeta whose significance although discussed, is far from being understood. The identification of such subsets, anyhow, may strongly contribute to distinguish Alzheimer's disease from dementia with Lewy bodies, opening possible new routes to early therapeutic strategies.

Updates on Somatoform Disorders (SFMD) in Parkinson's Disease and Dementia with Lewy Bodies and discussion of phenomenology.

Somatoform Disorders (SFMD) were recently described in Parkinson Disease (PD) and Dementia with Lewy Bodies (DLB). The present paper updates the observations in our cohort of patients and further details clinical phenomenology. Of 3178 patients consecutively referred to our Institutions from 1999, 1572 subjects had neurodegenerative diseases and 1718 psychiatric disorders. After 2-9 years of follow up, 488 patients were labelled as PD, 415 as Alzheimer Disease, 162 as DLB, 48 as Progressive Supranuclear Palsy, 48 as Multiple System Atrophy and 49 as Fronto-Temporal Dementia. The frequency of SFMD (DSM-IV-TR criteria) was determined in each diagnostic category by direct observation of SFMD symptoms, psychiatric interviews, SCL 90Rss, collection of previous general practitioners and hospital charts. The frequency of SFMD was considerably higher in DLB (29 patients, 18%) and PD (37 patients, 7.5%) than in any other group (0-2%). The frequency of SFMD in psychiatric patients was 2%. SFMD in PD and DLB were characterised by motor and non-motor patterns and were often accompanied by catatonic signs consisting of posturing stereotypies and negativism (55%). SFMD symptoms preceded PD motor signs by 6 months-5 years in 92% of the 29 DLB and 37 PD patients and in 70% SFMD were recurrent at follow-up. In 93% of these patients, hypochondria was a preceding or concomitant background.

Abeta(1-42) stimulated T cells express P-PKC-delta and P-PKC-zeta in Alzheimer disease.

The protein kinase C (PKC) family of enzymes is a regulator of transmembrane signal transduction, and involvement of some PKC isoforms in T-cell activation has been demonstrated. Nevertheless, very little is known about their involvement in the Amyloid beta (Abeta)-dependent molecular signals in the T lymphocytes of Alzheimer disease (AD) patients. Therefore, the aim of this study was to investigate the involvement of PKC-alpha, PKC-delta and PKC-zeta expression and activity in the signaling machinery activated in Abeta-reactive T cells, in adult healthy individuals, elderly healthy subjects, and from patients with AD. The results show that in peripheral T-cells from early AD patients, Abeta(1-42) produced a distinct subpopulation highly expressing P-PKC-delta, while in severe AD patients the same treatment induced two distinct P-PKC-delta and P-PKC-zeta T-cell subpopulations. Such subpopulations were not noticeable following CD3/CD28 treatment of the same samples or after treatment of peripheral T cells from healthy adult or elderly subjects with Abeta(1-42) or with CD3/CD28. We believe that these findings may be of help in possible attempts to develop further diagnostic strategies useful for the characterization of AD.

Parallel regulation of PKC-alpha and PKC-delta characterizes the occurrence of erythroid differentiation from human primary hematopoietic progenitors.

OBJECTIVE: Erythroid differentiation is a process characterized by modulation of different proteins including phosphoinositide-related enzymes such as protein kinase C (PKC) isoforms. Because in different cell lines PKC-alpha and PKC-delta have been reported to be involved in the mechanisms controlling proliferation and differentiation, the aim of this study was to examine the relative involvement of these PKC isoforms in the development of CD235a+ erythroid cells from human healthy hematopoietic progenitors. MATERIALS AND METHODS: Erythroid differentiation from human primary hematopoietic progenitor cells was achieved by adopting the human erythroblasts mass amplification culture. Expression and activity of PKC isoforms and their relationship with proliferation and differentiation were investigated by morphologic analysis, reverse-transcriptase polymerase chain reaction, Western blotting, multiparametric flow cytometry, and transfection experiments. RESULTS: PKC-alpha was found expressed and phosphorylated in cells undergoing both proliferation and differentiation, although PKC-delta, largely expressed and activated during proliferation, was evidently downregulated during differentiation. Overexpression of PKC-delta-CAT scarcely influenced the development of glycophorin-A (CD235a)+ erythroid cells from hematopoietic progenitors, although overexpression of PKC-alpha-CAT strongly induced the development of CD235a+ erythroid cells. On the other hand, in PKC-alpha-CAT-transfected cells, pharmacologic inhibition of PKC-delta further increased the number of CD235a+ cells, although inhibition of PKC-alpha resulted in an evident impairment of the development of CD235a+ erythroid cells. CONCLUSIONS: Our results indicate that the suppression or at least a strong downregulation of PKC-delta, concomitant to PKC-alpha expression and activity, might be a cofactor to be further investigated and might be involved in the events regulating erythropoietin-induced erythroid differentiation from human primary hematopoietic progenitor cells.

Mitigation of tumor necrosis factor alpha cytotoxicity by aurintricarboxylic acid in human peripheral B lymphocytes.

The aims of this study were to ascertain whether aurintricarboxylic acid (ATA), an endonuclease inhibitor, known to interfere, with the actions of cytokines such as interferons, is able to antagonize the toxic effects produced by tumor necrosis factor alpha (TNF-alpha) in human healthy peripheral B lymphocytes and try to elucidate the molecular machinery through which this possible antagonism takes place. Results evidenced that the balance of survival signals of human B lymphocytes in the presence of TNF-alpha was altered by the interaction of TNF-alpha with a salicylate compound, ATA. Apoptosis effected by TNF-alpha alone was suppressed in the presence of ATA, and this effect appeared essentially characterized by: (i) phosphorylation of phosphatidylinositol-3 kinase (PI-3K), influencing in turn protein kinase B/Akt (Akt) and Bad phosphorylation; (ii) nuclear translocation of the nuclear factor kappa B (NF-kappaB) and (iii) nuclear translocation of protein kinase C zed (PKCzeta). Reversal of TNF-alpha/ATA effects occurred in the presence of the PI-3K specific inhibitors wortmannin or LY294002 in the culture medium and was coincident with inhibition of the translocation of PKCzeta in the nucleus, while NF-kappaB was less affected. These results indicate, therefore, that PI-3K-mediated activation and nuclear transfer of PKCzeta might be essential steps of ATA antagonism against TNF-alpha, suggesting that possible ATA pharmacological applications might be taken into account for staving off systemic or local toxic effects produced by TNF-alpha.