Bioactivity and miRNome Profiling of Native Extracellular Vesicles in Human Induced Pluripotent Stem Cell-Cardiomyocyte Differentiation.

Extracellular vesicles (EV) are an attractive therapy to boost cardiac regeneration. Nevertheless, identification of native EV and corresponding cell platform(s) suitable for therapeutic application, is still a challenge. Here, EV are isolated from key stages of the human induced pluripotent stem cell-cardiomyocyte (hiPSC-CM) differentiation and maturation, i.e., from hiPSC (hiPSC-EV), cardiac progenitors, immature and mature cardiomyocytes, with the aim of identifying a promising cell biofactory for EV production, and pinpoint the genetic signatures of bioactive EV. EV secreted by hiPSC and cardiac derivatives show a typical size distribution profile and the expression of specific EV markers. Bioactivity assays show increased tube formation and migration in HUVEC treated with hiPSC-EV compared to EV from committed cell populations. hiPSC-EV also significantly increase cell cycle activity of hiPSC-CM. Global miRNA expression profiles, obtained by small RNA-seq analysis, corroborate an EV-miRNA pattern indicative of stem cell to cardiomyocyte specification, confirming that hiPSC-EV are enriched in pluripotency-associated miRNA with higher in vitro pro-angiogenic and pro-proliferative properties. In particular, a stemness maintenance miRNA cluster upregulated in hiPSC-EV targets the PTEN/PI3K/AKT pathway, involved in cell proliferation and survival. Overall, the findings validate hiPSC as cell biofactories for EV production for cardiac regenerative applications.

Larvicidal Activities against Aedes aegypti of Supernatant and Pellet Fractions from Cultured Bacillus spp. Isolated from Amazonian Microenvironments.

The Aedes aegypti mosquito is the primary vector of Dengue, Chikungunya and Zika causing major problems for public health, which requires new strategies for its control, like the use of entomopathogenic microorganisms. In this study, bacteria from various Amazonian environments were isolated and tested for their pathogenicity to A. aegypti larvae. Following thermal shock to select sporulated Bacillus spp., 77 bacterial strains were isolated. Molecular identification per 16S RNA sequences revealed that the assembled strains contained several species of the genus Bacillus and one species each of Brevibacillus, Klebsiella, Serratia, Achromobacter and Brevundimonas. Among the isolated Bacillus sp. strains, 19 showed larvicidal activity against A. aegypti. Two strains of Brevibacillus halotolerans also displayed larvicidal activity. For the first time, larvicidal activity against A. aegypti was identified for a strain of Brevibacillus halotolerans. Supernatant and pellet fractions of bacterial cultures were tested separately for larvicidal activities. Eight strains contained isolated fractions resulting in at least 50% mortality when tested at a concentration of 5 mg/mL. Further studies are needed to characterize the active larvicidal metabolites produced by these microorganisms and define their mechanisms of action.

Venus Atmospheric Composition in situ Data: A Compilation.

The Venus atmosphere is of significant interest yet only rudimentary solid data has been gathered about its composition and chemistry. These measurements are scattered through time and place and are limited by parameters such as resolution and error margins as well as reinterpretations. This paper presents an extensive compilation of published in situ data for the atmospheric composition of Venus. It also includes remotely gathered measurements and some extrapolated and modeled data for the lower atmosphere. The composition tables are divided in four categories: noble gases, reactive gases, noble and non-noble isotopes. These tables were first presented in 2016 within the scientific heritage appendix of the Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging (DAVINCI) mission proposal. These tables provide respective measurements, error margins, techniques, altitudes, instruments, mission and references. The objective of this paper is to provide a simple, comprehensive list of available measurements to date; in particular, the in situ data, to serve as a quick overall Venus atmosphere data reference.