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

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

Pedigrees of the 11 patient harbouring a <i>PDCD10</i>/CCM3 mutation.

<p>The arrow indicates the index case. Squares represent males; circles, females. A diagonal line through the symbol represents a deceased person.</p

1–3 MRI/TC scans from subjects

<p>: 1) 454CCM patient harbouring the <i>de novo</i> and novel mutation p.E54Rfs*22. A) T1 sagittal image at 16 months showing a cavernous malformation with recent bleeding in the pons; B) T1 axial image at 25 months showing increased size of the pontine cavernous malformation with compression on the mesencephalon, the cisterna interpeduncularis and the cisterna pontis. 2) 321CCM patient harbouring the mutation p.R35X. A) Imaging characteristics of the CCM lesion (in the white circle) located at the left anterior temporal lobe: at CT scan the lesion is inhomogeneous due to haemorrhagic components, B and D) the haemorrhagic component is hyperintense both in T1 and in T2 sequences, C) contrast enhancement is absent, E) and at GET2* the lesion is hypointense due to the paramagnetic characteristics of the haemosiderin ring and of the clotted lesion content. F) Finally, other two lesions can be detected at other sites (arrows) in the same patient. 3) 344CCM patient harbouring the novel mutation p.R54X. A) MRI showed a right cortical and subcortical parietal hemorrhagic CCM lesion (arrow) and other non-hemorrhagic CCM lesions at different sites: bilateral temporal polar (not shown), B) left superior temporal sulcus (arrow) and right parietal (arrowhead), left insular and fronto-insular (not shown), C) left frontal parasagittal (arrow), subcortical frontal with small areas of vacuolization and microcalcification, left posteromedial thalamic (not shown).</p

Schematic representation of PDCD10 protein with its domains and the main interactors.

<p>Mutations are reported.</p

Patients' clinical features.

<p>Y = Yes; N = No; nr =  not reported; ni =  not investigated.</p><p>Patients' clinical features.</p

Details of Patients' mutation.

<p>Y =  Yes; N = No. Nomenclature according to HGVS.</p><p>Details of Patients' mutation.</p