Extracellular vesicles (EVs) have emerged as important mediators of intercellular communication in a diverse range of biological processes. For future therapeutic applications and for EV biology ...research in general, understanding the in vivo fate of EVs is of utmost importance. Here we studied biodistribution of EVs in mice after systemic delivery. EVs were isolated from 3 different mouse cell sources, including dendritic cells (DCs) derived from bone marrow, and labelled with a near-infrared lipophilic dye. Xenotransplantation of EVs was further carried out for cross-species comparison. The reliability of the labelling technique was confirmed by sucrose gradient fractionation, organ perfusion and further supported by immunohistochemical staining using CD63-EGFP probed vesicles. While vesicles accumulated mainly in liver, spleen, gastrointestinal tract and lungs, differences related to EV cell origin were detected. EVs accumulated in the tumour tissue of tumour-bearing mice and, after introduction of the rabies virus glycoprotein-targeting moiety, they were found more readily in acetylcholine-receptor-rich organs. In addition, the route of administration and the dose of injected EVs influenced the biodistribution pattern. This is the first extensive biodistribution investigation of EVs comparing the impact of several different variables, the results of which have implications for the design and feasibility of therapeutic studies using EVs.
Display omitted
•Microglial cell activation in SNpc precedes alpha-synuclein inclusion formation.•In striatum a significant astrogliosis was observed 90 dpi.•Alpha-synuclein monomer did not result in ...long-term glia activation.•Neuroinflammation is an early event in PD pathogenesis.
Neuroinflammation is increasingly recognized as an important feature in the pathogenesis of Parkinson’s disease (PD). However, it remains unclear whether neuroinflammation contributes to nigral degeneration in PD or is merely a secondary marker of neurodegeneration. We aimed to investigate the temporal relationship between synucleopathy, neuroinflammation and nigrostriatal degeneration in a mouse model of PD. Mice received unilateral intrastriatal injection of alpha-synuclein pre-formed fibrils, alpha-synuclein monomer or vehicle and were sacrificed at 15, 30 and 90 days post-injection. Intrastriatal inoculation of alpha-synuclein fibrils led to significant alpha-synuclein aggregation in the substantia nigra peaking at 30 days after injection while the significant increase in Iba-1 cells, GFAP cells and IL-1β expression peaked earlier at 15 days. At 90 days, the striatal dopaminergic denervation was associated with astroglial activation. Alpha-synuclein monomer did not result in long-term glia activation or increase in inflammatory markers. The spread of alpha-synuclein aggregates into the cortex was not associated with any changes to neuroinflammatory markers. Our results demonstrate that in the substantia nigra glial activation is an early event that precedes alpha-synuclein inclusion formation, suggesting neuroinflammation could play an important early role in the pathogenesis of PD.
Although the factors contributing to the pathogenesis of neurodegenerative diseases remain elusive, endolysosomal pathway is emerging as a key player in the pathogenesis of neurodegenerative ...diseases. The link between endolysosomal dysfunction and neurodegeneration is supported by genetic studies identifying disease mutations in genes controlling endolysosomal function. Growing evidence suggests that endolysosomal dysfunction affect the production, secretion and content of exosomes. Current data suggests that exosomes play a key role in Parkinson's disease (PD) and Alzheimer's disease (AD) progression, interfering with the transmission of pathological proteins or neuroinflammatory factors related to neurodegenerative diseases. This review summarizes recent advances in the role of endolysosomal dysfunction in the spreading of pathological proteins mediated by exosomes in the two most common neurodegenerative diseases, AD and PD.
To realize the therapeutic potential of RNA drugs, efficient, tissue-specific and nonimmunogenic delivery technologies must be developed. Here we show that exosomes-endogenous nano-vesicles that ...transport RNAs and proteins-can deliver short interfering (si)RNA to the brain in mice. To reduce immunogenicity, we used self-derived dendritic cells for exosome production. Targeting was achieved by engineering the dendritic cells to express Lamp2b, an exosomal membrane protein, fused to the neuron-specific RVG peptide. Purified exosomes were loaded with exogenous siRNA by electroporation. Intravenously injected RVG-targeted exosomes delivered GAPDH siRNA specifically to neurons, microglia, oligodendrocytes in the brain, resulting in a specific gene knockdown. Pre-exposure to RVG exosomes did not attenuate knockdown, and non-specific uptake in other tissues was not observed. The therapeutic potential of exosome-mediated siRNA delivery was demonstrated by the strong mRNA (60%) and protein (62%) knockdown of BACE1, a therapeutic target in Alzheimer's disease, in wild-type mice.
The development of new therapies to slow down or halt the progression of Parkinson’s disease is a health care priority. A key pathological feature is the presence of alpha-synuclein aggregates, and ...there is increasing evidence that alpha-synuclein propagation plays a central role in disease progression. Consequently, the downregulation of alpha-synuclein is a potential therapeutic target. As a chronic disease, the ideal treatment will be minimally invasive and effective in the long-term. Knockdown of gene expression has clear potential, and siRNAs specific to alpha-synuclein have been designed; however, the efficacy of siRNA treatment is limited by its short-term efficacy. To combat this, we designed shRNA minicircles (shRNA-MCs), with the potential for prolonged effectiveness, and used RVG-exosomes as the vehicle for specific delivery into the brain. We optimized this system using transgenic mice expressing GFP and demonstrated its ability to downregulate GFP protein expression in the brain for up to 6 weeks. RVG-exosomes were used to deliver anti-alpha-synuclein shRNA-MC therapy to the alpha-synuclein preformed-fibril-induced model of parkinsonism. This therapy decreased alpha-synuclein aggregation, reduced the loss of dopaminergic neurons, and improved the clinical symptoms. Our results confirm the therapeutic potential of shRNA-MCs delivered by RVG-exosomes for long-term treatment of neurodegenerative diseases.
Display omitted
This study demonstrated the potential of shRNA minicircles delivered by RVG-exosomes to induce the long-term downregulation of targeted genes in the brain. Izco and colleagues proved, using a parkinsonian mouse model, that this therapy can prevent the loss of dopaminergic neurons, decrease alpha-synuclein aggregates, and avoid the motor deficit.
Abstract Alpha-synuclein aggregation plays a central role in Parkinson's disease pathology. Direct transmission of alpha-synuclein from pathologically affected to healthy unaffected neurons may be ...important in the anatomical spread of the disease through the nervous system. We have demonstrated that exosomes released from alpha-synuclein over-expressing SH-SY5Y cells contained alpha-synuclein and these exosomes were capable of efficiently transferring alpha-synuclein protein to normal SH-SY5Y cells. Moreover, the incubation of cells with ammonium chloride or bafilomycin A1 to produce the lysosomal dysfunction recently reported in Parkinson's disease led to an increase in the release of alpha-synuclein in exosomes and a concomitant increase in alpha-synuclein transmission to recipient cells. This study clearly demonstrates the importance of exosomes in both the release of alpha synuclein and its transmission between cells and suggests that factors associated with PD pathology accelerate this process. These mechanisms may play an important role in PD pathology and provide a suitable target for therapeutic intervention.
•KN95 and filtering face piece two masks were disinfected by atmospheric pressure cold plasma.•Nitrogen plasma treatment achieved the best bacterial inactivation.•Pseudomonas aeruginosa and ...Escherichia coli were inactivated mainly by the thermal effect.•Reactive oxygen and nitrogen species generated in plasma were the main cause of the Staphylococcus aureus antimicrobial effect.•Filtration capacity and breathability did not change after five cycles of plasma treatment.
Mask usage has increased over the last few years due to the COVID-19 pandemic, resulting in a mask shortage. Furthermore, their prolonged use causes skin problems related to bacterial overgrowth. To overcome these problems, atmospheric pressure cold plasma was studied as an alternative technology for mask disinfection.
Different microorganisms (Pseudomonas aeruginosa, Escherichia coli, Staphylococcus spp.), different gases (nitrogen, argon, and air), plasma power (90-300 W), and treatment times (45 seconds to 5 minutes) were tested.
The best atmospheric pressure cold plasma treatment was the one generated by nitrogen gas at 300 W and 1.5 minutes. Testing of breathing and filtering performance and microscopic and visual analysis after one and five plasma treatment cycles, highlighted that these treatments did not affect the morphology or functional capacity of the masks.
Considering the above, we strongly believe that atmospheric pressure cold plasma could be an inexpensive, eco-friendly, and sustainable mask disinfection technology enabling their reusability and solving mask shortage.
Display omitted
► Alpha-synuclein directly activates the inflammatory response in BV-2 cells. ► Conditioned medium from alpha-synuclein expressing cells induces inflammation. ► MPP+ exacerbates the inflammatory ...potential of conditioned medium.
The neurodegenerative process in Parkinson's disease (PD) is accompanied by the presence of a neuroinflammatory response, which has been suggested as one of the principal components involved in PD progression.
In this report we assessed the inflammatory potential of alpha-synuclein, a protein central to PD pathogenesis, released by neurons on the mouse microglia cell line BV-2. BV-2 cells were treated with conditioned medium isolated from normal SH-SY5Y cells and clones that over-express WT or mutant A53T alpha-synuclein. Conditioned medium isolated from over-expressing clones induced the transcription and release of pro-inflammatory cytokines. Treatment of SH-SY5Y alpha-synuclein over-expressing cells with MPP+, the active metabolite of the neurotoxin MPTP, increased the inflammatory response in BV-2 cells. In contrast, the direct exposure of BV-2 cells to MPP+ failed to induce an inflammatory response.
These results support the hypothesis that WT and A53T alpha-synuclein has an important role in the initiation and maintenance of inflammation in PD, through the activation of a pro-inflammatory response in microglial cells.
PDF
