Cross‐kingdom communication via non‐coding RNAs is a recent discovery. Exogenous microRNAs (exog‐miRNAs) mainly enter the host via the diet. Generally considered unstable in the gastrointestinal ...tract, some exogenous RNAs may resist these conditions, especially if transported in extracellular vesicles. They could then reach the intestines and more probably exert a regulatory effect. We give an overview of recent discoveries concerning dietary miRNAs, possible ways of enhancing their resistance to food processing and gut conditions, their transport in extracellular vesicles (animal‐ and plant‐origin) and possible biological effects on recipient cells after ingestion. We critically focus on what we believe are the most relevant data for future pharmacological development of dietary miRNAs as therapeutic agents. Finally, we discuss the miRNA‐mediated cross‐kingdom regulation between diet, host and the gut microbiota. We conclude that, despite many obstacles and challenges, extracellular miRNAs are serious candidates to be targeted pharmacologically for development of new therapeutic agents.
Extracellular vesicles (EVs) are emerging as novel theranostic tools. Limitations related to clinical uses are leading to a new research area on design and manufacture of artificial EVs. Several ...strategies have been reported in order to produce artificial EVs, but there has not yet been a clear criterion by which to differentiate these novel biomaterials. In this paper, we suggest for the first time a systematic classification of the terms used to build up the artificial EV landscape, based on the preparation method. This could be useful to guide the derivation to clinical trial routes and to clarify the literature. According to our classification, we have reviewed the main strategies reported to date for their preparation, including key points such as: cargo loading, surface targeting strategies, purification steps, generation of membrane fragments for the construction of biomimetic materials, preparation of synthetic membranes inspired in EV composition and subsequent surface decoration.
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•Vesicle size depend on the composition of the hydrating solution.•PEG-400 aqueous-based solution led the formation of larger vesicles than glycerol and aqueous based ...media.•Encapsulation efficiency (EE) increased when poly-ol based solution were used, probably because the bigger vesicle size.•Vesicle size was affected by the molecular weight of the compounds incorporated.•The composition of the hydrating solution might enhance the EE especially in particular cases.
Encapsulation into nanocarriers, such as niosomes, is a promising way to protect them from degradation, and allow controll and target delivery of bioactive compounds. For biotechnological applications, a tight control of particle size with acceptable encapsulation efficiencies (EE) is a technological challenge, especially for hydrophilic compounds due to its capability to diffuse across biological barriers. Niosomes formulated with mixture of surfactants represent promising nanocarriers due to the advantages of non-ionic surfactants, such as low cost, versatility and enhanced physico-chemical properties. In this work, the effect of both, composition of the hydrating solution and molecular weight of the loaded compound, on the particle size and EE of niosomes prepared by using the thin film hydration method was studied. Particularly, mili-Q water, glycerol solution and PEG-400 solution were tested for niosomes formulated with Span®80-Tween®80 with/without dodecanol as membrane stabilizer. It was found that particle size highly depends on hydration media composition and an interaction with compound MW could exist. Larger vesicles results in an increase in EE, which could be purely related with physical aspects such as vesicle loading volume capacity. The effect of hydration solution composition could be related with their ability to change the bilayer packing and physical properties, as observed by differential scanning calorimetry. Finally, it was possible to compare the suitability of dialysis and gel filtration as purification methods, demonstrating that gel filtration is not an adequate purification method when viscous solutions are used, since they could affect the particle vesicles retention and hence EE measurements would be misrepresentative.
KRASG12C inhibitors have revolutionized the clinical management of patients with KRASG12C-mutant lung adenocarcinoma. However, patient exposure to these inhibitors leads to the rapid onset of ...resistance. In this study, we have used genetically engineered mice to compare the therapeutic efficacy and the emergence of tumor resistance between genetic ablation of mutant Kras expression and pharmacological inhibition of oncogenic KRAS activity. Whereas Kras ablation induces massive tumor regression and prevents the appearance of resistant cells in vivo, treatment of KrasG12C/Trp53-driven lung adenocarcinomas with sotorasib, a selective KRASG12C inhibitor, caused a limited antitumor response similar to that observed in the clinic, including the rapid onset of resistance. Unlike in human tumors, we did not observe mutations in components of the RAS-signaling pathways. Instead, sotorasib-resistant tumors displayed amplification of the mutant Kras allele and activation of xenobiotic metabolism pathways, suggesting that reduction of the on-target activity of KRASG12C inhibitors is the main mechanism responsible for the onset of resistance. In sum, our results suggest that resistance to KRAS inhibitors could be prevented by achieving a more robust inhibition of KRAS signaling mimicking the results obtained upon Kras ablation.
Background
“Hospital-at-home” (HAH) programs have been shown to optimize resource utilization, shorten hospitalization and prevent nosocomial infection.
Methods
We retrospectively analysed data ...regarding implementation of an HAH unit for caring patients with hematological malignancies in our center, during the COVID-19 pandemic.
Results
Between January and November 2020, 105 patients were treated in the HAH unit for a total of 204 episodes. Nine patients with multiple myeloma (MM) received autologous HSCT (auto-HSCT). Three patients with acute myeloid leukemia (AML) received consolidation therapy, 32 patients underwent clinical and analytical monitoring, 20 were transplant recipients early discharged (5 auto-HSCT and 15 allo-HSCT) and 2 had received CART cells therapy. Azacitidine, bortezomib and carfilzomib were administered at home to 54 patients with AML, myelodysplastic syndrome (MDS) or MM. A median of 17 (IQR 13–19) days of admission per patient and a total of 239 visits to the Hematology day-care hospital were avoided. Overall, 28 patients (14% of all episodes) needed admission to the hospital, 4 of them due to COVID-19.
Conclusions
Implementation of a Hematology HAH unit was feasible and safe, and provided thorough advanced care to a high-risk population. Advanced care-at-home strategies can be crucial during times of COVID-19 to minimize treatment interruptions and reduce the risk of cross-infections.
A “box‐in‐box” cocultivation system was used to investigate plant responses to microbial volatile compounds (VCs) and to evaluate the contributions of organic and inorganic VCs (VOCs and VICs, ...respectively) to these responses. Arabidopsis plants were exposed to VCs emitted by adjacent Alternaria alternata and Penicillium aurantiogriseum cultures, with and without charcoal filtration. No VOCs were detected in the headspace of growth chambers containing fungal cultures with charcoal filters. However, these growth chambers exhibited elevated CO2 and bioactive CO and NO headspace concentrations. Independently of charcoal filtration, VCs from both fungal phytopathogens promoted growth and distinct developmental changes. Plants cultured at CO2 levels observed in growth boxes containing fungal cultures were identical to those cultured at ambient CO2. Plants exposed to charcoal‐filtered fungal VCs, nonfiltered VCs, or superelevated CO2 levels exhibited transcriptional changes resembling those induced by increased irradiance. Thus, in the “box‐in‐box” system, (a) fungal VICs other than CO2 and/or VOCs not detected by our analytical systems strongly influence the plants' responses to fungal VCs, (b) different microorganisms release VCs with distinct action potentials, (c) transcriptional changes in VC‐exposed plants are mainly due to enhanced photosynthesis signaling, and (d) regulation of some plant responses to fungal VCs is primarily posttranscriptional.
Using a “box‐in‐box” test system, here, we have conducted studies to address the question of whether volatile compounds (VCs) from different microorganisms can promote distinct responses in plants. In addition, we evaluated the contribution of microbial organic and inorganic VCs (VOCs and VICs, respectively) in these responses by performing comparative analyses of plants' responses to CO2, complex mixtures of VICs and VOCs, and VOCs‐depleted (VICs‐containing) VCs from two fungal phytopathogens. Our results show that respiratory CO2 plays only a minor role in plant responses to microbial VCs and present evidence that mixtures of VICs from different microorganisms can promote growth and distinct developmental changes in plants. We also provide evidence that (a) the transcriptional changes occurring in plants exposed to microbial VCs are indirectly due to enhanced photosynthesis, and (b) plants' responses to fungal VCs are primarily regulated at the posttranscriptional level.
Purpose
Extracellular RNAs are unstable and rapidly degraded unless protected. Bovine-milk extracellular vesicles (EVs) confer protection to dietary miRNAs, although it remains unclear whether this ...importantly improves their chances of reaching host target cells to exert biological effects.
Methods
Caco-2, HT-29, Hep-G2 and FHs-74 cell lines were exposed to natural/labelled milk EVs to evaluate cellular uptake. Five frequently reported human milk miRNAs (miR-146b-5p, miR-148a-3p, miR-30a-5p, miR-26a-5p, and miR-22-3p) were loaded into EVs. The intracellular concentration of each miRNA in cells was determined. In addition, an animal study giving an oral dose of loaded EVs in C57BL6/ mice were performed. Gene expression regulation was assessed by microarray analysis.
Results
Digestive stability analysis showed high overall degradation of exogenous miRNAs, although EV-protected miRNAs better resisted gastrointestinal digestion compared to free miRNAs (tenfold higher levels). Importantly, orally delivered EV-loaded miRNAs reached host organs, including brain, in mice. However, no biological effect has been identified.
Conclusion
Milk EVs protect miRNAs from degradation and facilitate cellular uptake. miRNA concentration in EVs from bovine milk might be insufficient to produce gene modulation. Nevertheless, sizable amounts of exogenous miRNAs may be loaded into EVs, and orally delivered EV-loaded miRNAs can reach tissues in vivo, increasing the possibility of exerting biological effects. Further investigation is justified as this could have an impact in the field of nutrition and health (i.e., infant formulas elaboration).
Cell-to-cell communication strategies include extracellular vesicles (EVs) in plants and animals. The bioactive molecules in a diet rich in vegetables and fruits are associated with ...disease-preventive effects. Plant-derived EVs (PDEVs) are biogenetically and morphologically comparable to mammalian EVs and transport bioactive molecules, including miRNAs. However, the biological functions of PDEVs are not fully understood, and standard isolation protocols are lacking. Here, PDEVs were isolated from four foods with a combination of ultracentrifugation and size exclusion chromatography, and evaluated as vehicles for enhanced transport of synthetic miRNAs. In addition, the role of food-derived EVs as carriers of dietary (poly)phenols and other secondary metabolites was investigated. EVs from broccoli, pomegranate, apple, and orange were efficiently isolated and characterized. In all four sources, 4 miRNA families were present in tissues and EVs. miRNAs present in broccoli and fruit-derived EVs showed a reduced RNase degradation and were ferried inside exposed cells. EVs transfected with a combination of ath-miR159a, ath-miR162a-3p, ath-miR166b-3p, and ath-miR396b-5p showed toxic effects on human cells, as did natural broccoli EVs alone. PDEVs transport trace amounts of phytochemicals, including flavonoids, anthocyanidins, phenolic acids, or glucosinolates. Thus, PDEVs can act as nanocarriers for functional miRNAs that could be used in RNA-based therapy.
MicroRNAs (miRNAs) are small non-coding RNAs with a known role as mediators of gene expression in crucial biological processes, which converts them into high potential contenders in the ongoing ...search for effective therapeutic strategies. However, extracellular RNAs are unstable and rapidly degraded, reducing the possibility of successfully exerting a biological function in distant target cells. Strategies aimed at enhancing the therapeutic potential of miRNAs include the development of efficient, tissue-specific and nonimmunogenic delivery methods. Since miRNAs were discovered to be naturally transported within exosomes, a type of extracellular vesicle that confers protection against RNase degradation and increases miRNA stability have been proposed as ideal delivery vehicles for miRNA-based therapy. Although research in this field has grown rapidly in the last few years, a standard, reproducible and cost-effective protocol for exosome isolation and extracellular RNA delivery is lacking. We aimed to evaluate the use of milk-derived extracellular vesicles as vehicles for extracellular RNA drug delivery. With this purpose, exosomes were isolated from raw bovine milk, combining ultracentrifugation and size exclusion chromatography (SEC) methodology. Isolated exosomes were then loaded with exogenous hsa-miR148a-3p, a highly expressed miRNA in milk exosomes. The suitability of exosomes as delivery vehicles for extracellular RNAs was tested by evaluating the absorption of miR-148a-3p in hepatic (HepG2) and intestinal (Caco-2) cell lines. The potential exertion of a biological effect by miR-148a-3p was assessed by gene expression analysis, using microarrays. Results support that bovine milk is a cost-effective source of exosomes which can be used as nanocarriers of functional miRNAs with a potential use in RNA-based therapy. In addition, we show here that a combination of ultracentrifugation and SEC technics improve exosome enrichment, purity, and integrity for subsequent use.
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