A novel peptide for microRNA delivery to medulloblastoma cells

Medulloblastoma is a paediatric brain cancer categorised into various subtypes that have differing prognostic outcomesfor patients. As with other cancers, microRNAs have been implicated in medulloblastoma pathogenesis andthe loss of specific miRNAs appears to contribute to the disease. There is therefore an urgent need to developmiRNA-replacement therapies for medulloblastoma. However, methods for targeted delivery of small RNAs to medulloblastomacells have not been fully established. As a step towards tackling this challenge, we have developedself-assembling peptide nanoparticles for small RNA delivery to medulloblastoma cells. We generated an amphiphilicpeptide, TY-28, using solid-phase peptide synthesis and combined TY-28 with miR-124-3p. Analysis of the resultingcomplexes by electron microscopy and dynamic light scattering confirmed the formation of nanoparticles. The abilityof the NPs to penetrate cells was monitored by labelling the miRNA with a fluorescent dye. The NP:miRNA complexeswere readily internalised by group 3 medulloblastoma cells, and the accumulation of the complexes increased overtime. Levels of uptake were 6-fold higher at 24 hours compared to 4 hours in serum-free medium. The uptake of theNPs complexes by the cells did not differ in the presence and absence of serum, suggesting the presence of serumdid not affect complex stability. Our findings point to the translational potential of self-assembled NPs to delivery miRNAmimics to medulloblastoma cells

Restoring the Final Frontier: Exosomal MicroRNA and Cutaneous Wound Repair

oai:openjournals.ljmu.ac.uk:article/601Non-healing wounds present a major healthcare challenge associated with the ageing population, the rising incidence of diabetes and the obesity epidermic. Driven by the need to expand therapeutic options for the treatment of such wounds, a large body of evidence has emerged in recent years demonstrating that microRNAs (miRNAs) modulate various aspects of cutaneous wound healing through effects on diverse cell types, including keratinocytes, fibroblasts, endothelial cells and macrophages. However, clear translational pathways for non-invasive cutaneous delivery of miRNAs to facilitate wound repair have not yet been established. The recognition that miRNAs can be actively partitioned into extracellular vesicles (EVs)—exosomes, microvesicles and apoptotic bodies—has stimulated research into the regulation, function and translational exploitation of EV-derived miRNAs both as a novel mode of intercellular signalling and as a tool for miRNA transfer to cells for therapeutic purposes. In particular, because mesenchymal stem cells (MSCs) were found to support wound healing, there is much interest in the therapeutic potential of EVs, especially exosomes, derived from these cells. In this review, we survey some of the main mesenchymal stem cells (MSCs) for which exosomal miRNAs have been evaluated in the context of skin repair, including exosomes from adipose-derived MSCs, bone MSCs, amniotic MSCs and umbilical cord MSCs. Epithelial stem cell (EPSC)-derived exosomes are also considered, from keratinocytes and epidermal stem cells. The picture that emerges from studies on exosomes from various cell types reveal they share a limited set of exosomal miRNAs enhancing wound repair. We suggest a need for direct comparison of exosomal miRNA profiles from a range of MSCs and EPSCs. The ability of exogenous exosomal miRNAs to promote healing of chronic diabetic wounds also warrants further attention in order to more fully establish their therapeutic potential

Changes in total and functional bacterial genera following biochar application to planted soil

Biochar has the recognized potential to sequester carbon, facilitate contaminant amelioration and enhance agricul-tural crop yield. Different types of biochar have different impacts on ecosystems, and those that are produced locally, relative to where they will be used, are considered more sustainable. It is important, therefore, to determine how the locally produced biochars affect total and functional microbial communities, especially in agronomic contexts. In this study we tested the hypotheses that biochar augmentation would: (1) increase plant yield; and (2) differentially affect total and functional microbial community composition and structure in bulk vs. rhizosphere (Trifolium pratense) soils. Triplicate randomised seedling cells of a 5% (w/w) mixture of sandy clay loam soil (26% clay, 21% silt and 53% sand), with/without locally-produced mixed broadleaf forestry biochar, and with/without 0.1 g clover seeds, were sampled destructively at 2-week intervals for 8 weeks post clover germination. Microbial DNA of bulk and T. pratense rhizos-phere soils were analysed with next-generation sequencing of the 16S rRNA gene. The results showed a statistically significant increase in plant biomass in response to biochar addition correlating to increased abundances of Armati-monadetes and Bacteroidetes specifically in the rhizosphere. Although no significant change in overall alpha diversity was observed, significant changes in abundance at the genus level were recorded particularly in the presence of biochar for a number of recognised nitrogen-fixing and plant growth-promoting bacteria, including those capable of indole acetic acid (IAA) production, plant disease suppression and degradation of toxic compounds. We conclude that although overall soil diversity may not be affected by biochar addition, key genera associated with soil health and nitrogen fixation, such as Pseudoxanthomonas, Variovorax, Pseudonocardia, Devosia, Lysobacter and Hydrogeno-phaga, increased and facilitated plant growth