Exploratory study on microRNA profiles from plasma-derived extracellular vesicles in Alzheimer’s disease and dementia with Lewy bodies

Background:Because of the increasing life expectancy in our society,aging-related neurodegenerative disorders are one of the main issues in global health.Most of these diseases are characterized by the deposition of misfolded proteins and a progressive cognitive decline.Among these diseases,Alzheimer’s disease(AD)and dementia with Lewy bodies(DLB)are the most common types of degenerative dementia.Although both show specific features,an important neuropathological and clinical overlap between them hampers their correct diagnosis.In this work,we identified molecular biomarkers aiming to improve the misdiagnosis between both diseases.Methods:Plasma extracellular vesicles(EVs)-from DLB,AD and healthy controls-were isolated using size-exclusion chromatography(SEC)and characterized by flow cytometry,Nanoparticle Tracking Analysis(NTA)and cryo-electron microscopy.Next Generation Sequencing(NGS)and related bibliographic search was performed and a selected group of EV-associated microRNAs(miRNAs)was analysed by qPCR.Results:Results uncovered two miRNAs(hsa-miR-451a and hsa-miR-21-5p)significantly down-regulated in AD samples respect to DLB patients,and a set of four miRNAs(hsa-miR-23a-3p,hsa-miR-126-3p,hsa-let-7i-5p,and hsamiR-151a-3p)significantly decreased in AD respect to controls.The two miRNAs showing decreased expression in AD in comparison to DLB provided area under the curve(AUC)values of 0.9 in ROC curve analysis,thus suggesting their possible use as biomarkers to discriminate between both diseases.Target gene analysis of these miRNAs using prediction online tools showed accumulation of phosphorylation enzymes,presence of proteasome-related proteins and genes involved in cell death among others.Conclusion:Our data suggest that plasma-EV associated miRNAs may reflect a differential profile for a given dementia-related disorder which,once validated in larger cohorts of patients,could help to improve the differential diagnosis of DLB versus AD.

Local administration of porcine immunomodulatory,chemotactic and angiogenic extracellular vesicles using engineered cardiac scaffolds for myocardial infarction

The administration of extracellular vesicles(EV)from mesenchymal stromal cells(MSC)is a promising cell-free nanotherapy for tissue repair after myocardial infarction(MI).However,the optimal EV delivery strategy remains undetermined.Here,we designed a novel MSC-EV delivery,using 3D scaffolds engineered from decellularised cardiac tissue as a cell-free product for cardiac repair.EV from porcine cardiac adipose tissue-derived MSC(cATMSC)were purified by size exclusion chromatography(SEC),functionally analysed and loaded to scaffolds.cATMSC-EV markedly reduced polyclonal proliferation and pro-inflammatory cytokines production(IFNγ,TNFα,IL12p40)of allogeneic PBMC.Moreover,cATMSC-EV recruited outgrowth endothelial cells(OEC)and allogeneic MSC,and promoted angiogenesis.Fluorescently labelled cATMSC-EV were mixed with peptide hydrogel,and were successfully retained in decellularised scaffolds.Then,cATMSC-EV-embedded pericardial scaffolds were administered in vivo over the ischemic myocardium in a pig model of MI.Six days from implantation,the engineered scaffold efficiently integrated into the post-infarcted myocardium.cATMSC-EV were detected within the construct and MI core,and promoted an increase in vascular density and reduction in macrophage and T cell infiltration within the damaged myocardium.The confined administration of multifunctional MSC-EV within an engineered pericardial scaffold ensures local EV dosage and release,and generates a vascularised bioactive niche for cell recruitment,engraftment and modulation of short-term post-ischemic inflammation.