Coronavirus disease 2019 or COVID-19, starting from Wuhan, China, in December 2019, is a pandemic situation affecting millions worldwide and has exerted a huge burden on healthcare infrastructure. Therefore, there is an urgent need to understand the molecular mechanisms underlying severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and design novel effective therapeutic strategies for combating this pandemic. In this regard, special attention has been paid to the exosomes. These nanoparticles are extracellular vesicles with critical function in the pathogenesis of several diseases including viral sepsis. Therefore, they may be involved in the pathogenesis of COVID-19 infection and also may be a way for transferring viral components and infecting other neighbor cells. Exosomes also can be considered as a therapeutic strategy for treating COVID-19 patients or used as a carrier for delivering effective therapeutic agents. Therefore, in this review, we discussed the biogenesis and contents of exosomes, their function in viral infection, and their potential as a therapeutic candidate in treating COVID-19.
Calculation of Skid Trail Spacing (STS) is an important option to minimize the total costs of skidding. Construction of many skid trails increases the construction cost, it also results in more degradation on different levels in forests. On the other hand, by constructing less skid trails, winching cost will increase, and in many cases, the skidders will exit from skid trails. This research was carried out in four districts under management of Mazandaran Wood and Paper Industry Company with the aim of determination of Optimum Skid Trail Spacing (OSTS) for an HSM skidder. In this study, a continuous time study method to the nearest second with stop watch was used. The results indicated that the time modelling of winching was mainly affected by load volume and winching distance. By using the time modelling of winching, the winching cost is estimated and then by combining that with the skid trail cost graph, the OSTS graph is calculated. Finally, 95 meters is calculated as optimum skid trail density in this study.
Background: Human adipose stem cells (hADSCs) are proper cell sources for tissue regeneration. They mainly mediate their therapeutic effects through paracrine factors as exosomes. The exosomes contents are protein, lipid and RNA. Exosomes are effective in restoring the function of neurons and astrocytes in neurodegenerative diseases, and improve the therapeutic outcomes. We investigated the effect of hADSCs derived exosomes on survival and neural differentiation of PC12 cells in vitro.Methods and Results: The isolated hADSCs, were characterized by ow cytometry. Exosomes were separated from hADSC-condition medium using Exo-spinTM kit and characterized by DLS and TEM.Then acridine orange staining was performed to con rm entrance of exosomes into PC12 cells. PC12 cells were treated with culture medium containing NGF and exosome. Cell viability was assessed by MTT assay, and neural differentiation by ICC technique and qRT-PCR.TEM and DLS data con rmed the isolation of exosomes according to their size (30-100nm) and acridine orange staining indicated entrance of exosomes to target cells. MTT assay showed that cell viability was signi cantly increased in exosome treated group. ICC technique revealed that the expression of Map2 was superior in the exosome treated group. Based on qRT-PCR data, Map2 and β-tub III gene expression was increased in the exosome treated group. Signi cant expression of Gfap was seen in the NGF and NGF/EXO treated groups.Conclusions: Present study indicated that hADSCs derived exosomes might enhance cell viability and promote neuronal differentiation and expression of mature neural marker in PC12 cells.
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