Microencapsulation technology by nature: Cell derived extracellular vesicles with therapeutic potential

Cell derived extracellular vesicles are submicron structures surrounded by phospholipid bilayer and released by both prokaryotic and eukaryotic cells. The sizes of these vesicles roughly fall into the size ranges of microbes, and they represent efficient delivery platforms targeting complex molecular information to professional antigen presenting cells. Critical roles of these naturally formulated units of information have been described in many physiological and pathological processes. Extracellular vesicles are not only potential biomarkers and possible pathogenic factors in numerous diseases, but they are also considered as emerging therapeutic targets and therapeutic vehicles. Strikingly, current drug delivery systems, designed to convey therapeutic proteins and peptides (such as liposomes), show many similarities to extracellular vesicles. Here we review some aspects of therapeutic implementation of natural, cell-derived extracellular vesicles in human diseases. Exploration of molecular and functional details of extracellular vesicle release and action may provide important lessons for the design of future drug delivery systems

Lack of neuroprotection in the absence of P2X7 receptors in toxin-induced animal models of Parkinson's disease

<p>Abstract</p> <p>Background</p> <p>Previous studies indicate a role of P2X₇receptors in processes that lead to neuronal death. The main objective of our study was to examine whether genetic deletion or pharmacological blockade of P2X₇receptors influenced dopaminergic cell death in various models of Parkinson's disease (PD).</p> <p>Results</p> <p>mRNA encoding P2X₇and P2X₄receptors was up-regulated after treatment of PC12 cells with 1-methyl-4-phenyl-1,2,3,6- tetrahydropyridine (MPTP). P2X₇antagonists protected against MPTP and rotenone induced toxicity in the LDH assay, but failed to protect after rotenone treatment in the MTT assay in PC12 cells and in primary midbrain culture. <it>In vivo </it>MPTP and <it>in vitro </it>rotenone pretreatments increased the mRNA expression of P2X₇receptors in the striatum and substantia nigra of wild-type mice. Basal mRNA expression of P2X₄receptors was higher in P2X₇knockout mice and was further up-regulated by MPTP treatment. Genetic deletion or pharmacological inhibition of P2X₇receptors did not change survival rate or depletion of striatal endogenous dopamine (DA) content after <it>in vivo </it>MPTP or <it>in vitro </it>rotenone treatment. However, depletion of norepinephrine was significant after MPTP treatment only in P2X₇knockout mice. The basal ATP content was higher in the substantia nigra of wild-type mice, but the ADP level was lower. Rotenone treatment elicited a similar reduction in ATP content in the substantia nigra of both genotypes, whereas reduction of ATP was more pronounced after rotenone treatment in striatal slices of P2X₇deficient mice. Although the endogenous amino acid content remained unchanged, the level of the endocannabinoid, 2-AG, was elevated by rotenone in the striatum of wild-type mice, an effect that was absent in mice deficient in P2X₇receptors.</p> <p>Conclusions</p> <p>We conclude that P2X₇receptor deficiency or inhibition does not support the survival of dopaminergic neurons in an <it>in vivo </it>or <it>in vitro </it>models of PD.</p

Központi idegrendszeri kannabinoid receptorok farmakológiai és funkcionális feltérképezése = Pharmacological and functional mapping central nervous system cannabinoid receptors

Kimutattuk, hogy bár a kannabinoidok GABA felszabadulásra gyakorolt hatását a hippokampuszban a CB1 receptorok közvetítik, ezek a hatások részben fennmaradnak a CB1 receptor genetikai törlése esetén is, valószínűleg egy "tartalék" kannabinoid receptor feldúsulása révén. Elsőként írtuk le és jellemeztük a kannabinoidok gátló hatását a szerotonin felszabadulásra a hippokampuszban. A kannabinoidok hatását a CB1-receptorok közvetítik, és az a szerotonerg terminálisoknak elsősorban egy szubpopulációjára terjed ki. Kimutattuk, hogy az endokannabinoidok a hippokampuszban a bazális IL-1beta produkció szabályozásában is szerepet játszanak, mégpedig stimuláló jelleggel és a P2X7 receptorok közvetítésével. Eredményeink elsőként igazolják, hogy a nucleus accumbens drog addikcióban kiemelten fontos szerepet játszó dopaminerg végződéseiből a kannabinoidok nemcsak a dopaminerg neuronok ventralis tegmentum-ban elhelyezkedő sejttestjeinek stimulálásával, hanem a nucleus accumbensen belüli hatással, dizinhibíciós mechanizmussal is képesek dopamint felszabadítani. Leírtuk a noradrenalin és acetilkolin felszabadulás frekvenciafüggő kannabinerg modulációját a prefrontális kéregben. Kimutattuk, hogy GPR3 receptor genetikai törlése az agyi monoamin tartalmak csökkenéséhez és ezzel korreláló magatartásváltozásokkal jár a szorongás és a depresszió állatkísérletes modelljeiben. | We showed that the effect of cannabinoids on GABA release in the hippocampus is mediated by CB1-cannabinoid receptors. However, these effects are partly maintained after genetic deletion of CB1 receptors, and probably due to a residual, 'backup' cannabinoid receptor, which is overexpressed in CB1 knockouts. We reported for the first time the inhibitory effect of cannabinoids on serotonin release from the hippocampus. The action of cannabinoids is mediated by CB1 receptors, but affects only one subpopulation of serotonergic nerve terminals. We showed that endocannabinoids stimulate basal IL-1beta production in the hippocampus, partly with the participation of P2X7 receptors. We provided the first neurochemical evidence that the activation of CB1 cannabinoid receptors leads to the augmentation of [3H]dopamine efflux via a local GABAA receptor-mediated disinhibitory mechanism in the rat nucleus accumbens. In addition, the frequency dependent modulation of noradrenaline and acetylcholine release by cannabinoids is characterized in the prefrontal cortex. We also showed that genetical deletion of GPR3 receptor leads to the depletion of monoamine content in the brain and consistent alterations of behavior in animal models of anxiety and depression

Effect of storage on physical and functional properties of extracellular vesicles derived from neutrophilic granulocytes.

AIM: To carry out a systematic study on the effect of different storage conditions on the number as well as the physical and functional properties of antibacterial extracellular vesicles (EVs) derived from human neutrophilic granulocytes. METHODS: Production of EVs with antibacterial properties was initiated by opsonized Zymosan A particles. The number of released fluorescent EVs was determined by flow cytometry following careful calibration. Physical properties and size of EVs were investigated by flow cytometry, dynamic light scattering and electron microscopy. Functional properties of EVs were tested by bacterial survival assay. RESULTS: Storage at +20 degrees C or +4 degrees C resulted in a significant decrease of EV number and antibacterial effect after 1 day. Storage at -20 degrees C did not influence the EV number up to 28 days, but induced a shift in EV size and almost complete loss of antibacterial function by 28 days. Storage at -80 degrees C had no significant effect either on EV number or size and allowed partial preservation of the antibacterial function up to 28 days. Snap-freezing did not improve the results, whereas the widely used cryoprotectants induced EV lysis. CONCLUSION: Storage significantly alters both the physical and functional properties of EVs even if the number of EVs stays constant. If storage is needed, EVs should be kept at -80 degrees C, preferably not longer than 7 days. For functional tests, freshly prepared EVs are recommended

Isolation of Exosomes from Blood Plasma: Qualitative and Quantitative Comparison of Ultracentrifugation and Size Exclusion Chromatography Methods

BACKGROUND: Exosomes are emerging targets for biomedical research. However, suitable methods for the isolation of blood plasma-derived exosomes without impurities have not yet been described. AIM: Therefore, we investigated the efficiency and purity of exosomes isolated with potentially suitable methods; differential ultracentrifugation (UC) and size exclusion chromatography (SEC). METHODS AND RESULTS: Exosomes were isolated from rat and human blood plasma by various UC and SEC conditions. Efficiency was investigated at serial UC of the supernatant, while in case of SEC by comparing the content of exosomal markers of various fractions. Purity was assessed based on the presence of albumin. We found that the diameter of the majority of isolated particles fell into the size range of exosomes, however, albumin was also present in the preparations, when 1h UC at 4 degrees C was applied. Furthermore, with this method only a minor fraction of total exosomes could be isolated from blood as deduced from the constant amount of exosomal markers CD63 and TSG101 detected after serial UC of rat blood plasma samples. By using UC for longer time or with shorter sedimentation distance at 4 degrees C, or UC performed at 37 degrees C, exosomal yield increased, but albumin impurity was still observed in the isolates, as assessed by transmission electron microscopy, dynamic light scattering and immunoblotting against CD63, TSG101 and albumin. Efficiency and purity were not different in case of using further diluted samples. By using SEC with different columns, we have found that although a minor fraction of exosomes can be isolated without significant albumin content on Sepharose CL-4B or Sephacryl S-400 columns, but not on Sepharose 2B columns, the majority of exosomes co-eluted with albumin. CONCLUSION: Here we show that it is feasible to isolate exosomes from blood plasma by SEC without significant albumin contamination albeit with low vesicle yield

Cardioprotection by remote ischemic preconditioning of the rat heart is mediated by extracellular vesicles

Remote ischemic preconditioning (RIPC) of the heart is exerted by brief ischemic insults affected on a remote organ or a remote area of the heart before a sustained cardiac ischemia. To date, little is known about the inter-organ transfer mechanisms of cardioprotection by RIPC. Exosomes and microvesicles/microparticles are vesicles of 30-100nm and 100-1000nm in diameter, respectively (collectively termed extracellular vesicles [EVs]). Their content of proteins, mRNAs and microRNAs, render EVs ideal conveyors of inter-organ communication. However, whether EVs are involved in RIPC, is unknown. Therefore, here we investigated whether (1) IPC induces release of EVs from the heart, and (2) EVs are necessary for cardioprotection by RIPC. Hearts of male Wistar rats were isolated and perfused in Langendorff mode. A group of donor hearts was exposed to 3x5-5min global ischemia and reperfusion (IPC) or 30min aerobic perfusion, while coronary perfusates were collected. Coronary perfusates of these hearts were given to another set of recipient isolated hearts. A group of recipient hearts received IPC effluent depleted of EVs by differential ultracentrifugation. Infarct size was determined after 30min global ischemia and 120min reperfusion. The presence or absence of EVs in perfusates was confirmed by dynamic light scattering, the EV marker HSP60 Western blot, and electron microscopy. IPC markedly increased EV release from the heart as assessed by HSP60. Administration of coronary perfusate from IPC donor hearts attenuated infarct size in non-preconditioned recipient hearts (12.9+/-1,6% vs. 25.0+/-2.7%), similarly to cardioprotection afforded by IPC (7.3+/-2.7% vs. 22.1+/-2.9%) on the donor hearts. Perfusates of IPC hearts depleted of EVs failed to exert cardioprotection in recipient hearts (22.0+/-2.3%). This is the first demonstration that EVs released from the heart after IPC are necessary for cardioprotection by RIPC, evidencing the importance of vesicular transfer mechanisms in remote cardioprotection

Effect of rat spinal cord injury (hemisection) on the ex vivo uptake and release of [3H]noradrenaline from a slice preparation

We measured the ex vivo uptake and release of [3H]noradrenaline ([3H]NA) from perfused rat spinal cord slice preparations at 1, 3 and 14days after unilateral hemisection-induced spinal cord injury (SCI) compared with control slice preparations. After surgical hemisection under anaesthesia, the rats showed characteristic signs of hemiplegia, with no movement of the ipsilateral hindlimb. After 3days, the electron microscopy images showed overall degeneration of neuronal organelles and the myelin sheath, but the synapses seemed to be intact. In ex vivo experiments, the spinal cord injury did not influence uptake but increased [3H]NA release at rest and in response to axonal stimulation. The effect of a selective noradrenaline reuptake inhibitor, nisoxetine, was studied to identify the mechanisms underlying the increase in NA release. Nisoxetine potentiated stimulation-evoked [3H]NA release from the non-injured tissue, but it gradually lost its effectiveness after injury, depending on the time (1 and 3days) elapsed after hemisection, indicating that the noradrenaline transporter binding sites of the terminals become impaired after decentralisation

A sejtek közti kommunikáció újonnan azonosított mikrovezikulum-útjának vizsgálata = Analysis of cell-derived microvesicles that represent novel players in intercellular communication

Munkánk során az extracelluláris vezikulák izolálásának és detektálásának számos meghatározó preanalitikai és analitikai paraméterére hívtuk fel a figyelmet. Elsőként mutattunk rá, hogy a mikrovezikulák és a fehérje-aggregátumok biofizikai paraméterei jelentős mértékben átfednek, és ez zavarhatja a mikrovezikulák mérését. Kidolgoztuk annak módszerét, hogy egyazon biológiai forrásból származó különböző vezikula populációkat párhuzamosan, nagy mennyiségben, intakt formában tudjunk izolálni. Összehasonlító proteomikai elemzést végeztünk thymus eredetű apoptotikus testek és mikrovezikulák esetében. Számos T sejt jelátvitelben és immunfolyamatokban szerepet játszó fehérjét és autoantigént azonosítottunk. Igazoltuk, hogy T sejt eredetű citokinek és extracelluláris vezikulák együttes hatását monociták génexpressziójára. Igazoltuk, hogy a mikrovezikulák önálló ionháztartással rendelkeznek. Kimutattuk, hogy thymocyta exoszómák nem tartalmaznak riboszómális RNS-eket, azonban feldúsulnak bennük kis RNS-ek (pl. bizonyos miRNS-ek). Polymyositises betegekben emelkedett keringő mikrovezikula számot mutattunk ki, mely korrelált a betegség bizonyos klinikai paramétereivel. Végül elsőként igazoltuk, hogy egészséges T sejt eredetű mikrovezikulák CD62P-CD161 kölcsönhatás révén specifikusan kötődnek monociták felszínéhez. | In our work we drove attention to several pre-analytical and analytical parameters affecting isolation and detection of work extracellular vesicles. We were the first to describe that microvesicles share biophysical parameters with protein aggregates which may confound microvesicle assessment by flow cytometry. We developed protocols for the isolation of large amounts of intact vesicle types secreted simultaneously by the same biological source. We carried comparative proteomic analysis of murine thymus derived apoptotic bodies and microvesicles. We identified large number of proteins involved in T cell signaling or immune functions as well as autoantigens within these structures. We provided evidence fro crosstalk between T cell derived extracellular vesicles and cytokines on the gene expression of monocytes. We have shown that microvesicles possess autonomous ion homeostasis. We found that thymocyte derived exosomes lacked the 18S and 28S ribosomal RNA molecules, while they were enriched in small RNA species (e.g. certain miRNAs). We described that patients with polyomyelitis were characterized by elevated levels of circulating microvesicle. Monocyte- and B cell-derived microvesicle numbers correlated with certain clinical parameters of the diseases. Finally, for the first time we showed that HLA-G+, trophoblast-derived microvesicles isolated from healthy pregnant blood plasma samples, bound specifically to T cells via CD62P-CD161 interaction, and induced STAT3 phosphorylation

Functionally and morphologically distinct populations of extracellular vesicles produced by human neutrophilic granulocytes.

EVs in the microvesicle size range released during spontaneous death of human neutrophils were characterized and their properties compared with previously described EVs with antibacterial effect (aEVs, generated on specific activation) or produced spontaneously (sEVs). The 3 vesicle populations overlapped in size and in part of the constituent proteins were stained with annexin V and were impermeable to PI. However, none of them produced superoxide. In contrast, remarkable differences were observed in the morphology, abundance of proteins, and antibacterial function. EVs formed spontaneously in 30 min (sEVs) were more similar to EVs released during spontaneous death in 1-3 days than to EVs formed in 30 min on stimulation of opsonin receptors (aEVs). Spontaneously generated EVs had no antibacterial effect despite their large number and protein content. We hypothesized 2 parallel mechanisms: one that proceeds spontaneously and produces EVs without antibacterial effect and another process that is triggered by opsonin receptors and results in differential sorting of proteins into EVs with antibacterial capacity. Our results call attention to the functional and morphologic heterogeneity within the microvesicle/ectosome fraction of EVs