Potential Therapeutic Effect of Micrornas in Extracellular Vesicles from Mesenchymal Stem Cells against SARS-CoV-2.

Extracellular vesicles (EVs) are cell-released, nanometer-scaled, membrane-bound materials and contain diverse contents including proteins, small peptides, and nucleic acids. Once released, EVs can alter the microenvironment and regulate a myriad of cellular physiology components, including cell-cell communication, proliferation, differentiation, and immune responses against viral infection. Among the cargoes in the vesicles, small non-coding micro-RNAs (miRNAs) have received attention in that they can regulate the expression of a variety of human genes as well as external viral genes via binding to the complementary mRNAs. In this study, we tested the potential of EVs as therapeutic agents for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. First, we found that the mesenchymal stem-cell-derived EVs (MSC-EVs) enabled the rescue of the cytopathic effect of SARS-CoV-2 virus and the suppression of proinflammatory responses in the infected cells by inhibiting the viral replication. We found that these anti-viral responses were mediated by 17 miRNAs matching the rarely mutated, conserved 3'-untranslated regions (UTR) of the viral genome. The top five miRNAs highly expressed in the MSC-EVs, miR-92a-3p, miR-26a-5p, miR-23a-3p, miR-103a-3p, and miR-181a-5p, were tested. They were bound to the complemented sequence which led to the recovery of the cytopathic effects. These findings suggest that the MSC-EVs are a potential candidate for multiple variants of anti-SARS-CoV-2.

Bioassay for monitoring the anti-aging effect of cord blood treatment.

Background: Treating aged animals with plasma of an early developmental stage (e.g, umbilical cord plasma) showed an impressive potential to slow age-associated degradation of neuronal and cognitive functions. Translating such findings to clinical realities, however, requires effective ways for assessing treatment efficacy; ideal methods should be minimally invasive, amenable for serial assays, cost-effective, and quantitative. Methods: We developed a new biosensor approach to monitor anti-aging therapy. We advanced two key sensor components: i) a blood-borne metabolite was identified as a surrogate aging-marker; and ii) a compact and cost-effective assay system was developed for on-site applications. We treated aged mice either with human umbilical cord plasma or saline; unbiased metabolite profiling on mouse plasma revealed arachidonic acid (AA) as a potent indicator associated with anti-aging effect. We next implemented a competitive magneto-electrochemical sensor (cMES) optimized for AA detection directly from plasma. The developed platform could detect AA directly from small volumes of plasma (0.5 µL) within 1.5 hour. Results: cMES assays confirmed a strong correlation between AA levels and anti-aging effect: AA levels, while decreasing with aging, increased in the plasma-treated aged mice which also showed improved learning and memory performance. Conclusions: The cMES platform will empower both pre- and clinical anti-aging research by enabling minimally invasive, longitudinal treatment surveillance; these capacities will accelerate the development of anti-aging therapies, improving the quality of individual lives.

Testing of a femtosecond pulse laser in outer space.

We report a test operation of an Er-doped fibre femtosecond laser which was conducted for the first time in outer space. The fibre-based ultrashort pulse laser payload was designed to meet space-use requirements, undergone through ground qualification tests and finally launched into a low-earth orbit early in 2013. Test results obtained during a one-year mission lifetime confirmed stable mode-locking all the way through although the radiation induced attenuation (RIA) in the Er-doped gain fibre caused an 8.6% reduction in the output power. This successful test operation would help facilitate diverse scientific and technological applications of femtosecond lasers in space and earth atmosphere in the near future.