Characterization of Potent ABCG2 Inhibitor Derived from Chromone: From the Mechanism of Inhibition to Human Extracellular Vesicles for Drug Delivery.

Inhibition of ABC transporters is a promising approach to overcome multidrug resistance in cancer. Herein, we report the characterization of a potent ABCG2 inhibitor, namely, chromone 4a (C4a). Molecular docking and in vitro assays using ABCG2 and P-glycoprotein (P-gp) expressing membrane vesicles of insect cells revealed that C4a interacts with both transporters, while showing selectivity toward ABCG2 using cell-based transport assays. C4a inhibited the ABCG2-mediated efflux of different substrates and molecular dynamic simulations demonstrated that C4a binds in the Ko143-binding pocket. Liposomes and extracellular vesicles (EVs) of Giardia intestinalis and human blood were used to successfully bypass the poor water solubility and delivery of C4a as assessed by inhibition of the ABCG2 function. Human blood EVs also promoted delivery of the well-known P-gp inhibitor, elacridar. Here, for the first time, we demonstrated the potential use of plasma circulating EVs for drug delivery of hydrophobic drugs targeting membrane proteins.

In Situ Synthesis of AZO-Np in Guar Gum/PVOH Composite Fiber Mats for Potential Bactericidal Release.

Since the number of antibiotic-resistant bacterial infections is growing and cases are getting worse every year, the search for new alternative bactericidal wound dressing treatments is becoming crucial. Within this context, the use of polysaccharides from plants and seeds in innovative biopolymer technologies is of key importance. In this work, bio-nano-composite guar gum/polyvinyl alcohol (PVOH) membranes loaded with aluminum-doped zinc oxide nanoparticles were produced via electrospinning. Citric acid was added to the mixture to increase spinnability. However, depending on the pH, zinc oxide nanoparticles are partially dissociated, decreasing their bactericidal efficiency. Thus, a second successful alkaline thermo-chemical regrowth step was added to the process to treat the obtained fibers. This alkaline thermo-chemical treatment reconstituted both the nanoparticles and their bactericidal properties. The Staphylococcus aureus antibacterial assay results show that the membranes obtained after the alkaline thermo-chemical treatment presented a 57% increase in growth inhibition.

Unveiling the role of EVs in anaerobic parasitic protozoa.

The anaerobic or microaerophilic protozoan parasites such as the enteric human pathogens Entamoeba histolytica, Giardia intestinalis, Cryptosporidium parvum, Blastocystis hominis and urogenital tract parasites Trichomonas vaginalis are able to survival in an environment with oxygen deprivation. Despite living in hostile environments these pathogens adopted different strategies to survive within the hosts. Among them, the release of extracellular vesicles (EVs) has become an active endeavor in the study of pathogenesis for these parasites. EVs are heterogenous, membrane-limited structures that have played important roles in cellular communication, transferring information through cargo and modulating the immune system of the host. In this review, we described several aspects of the recently characterized EVs of the anaerobic protozoa, including their role in adhesion, modulation of the immune response and omics analysis to understand the potential of these EVs in the pathogenesis of these diseases caused by anaerobic parasites.

Peptidylarginine Deiminase Inhibition Abolishes the Production of Large Extracellular Vesicles From Giardia intestinalis, Affecting Host-Pathogen Interactions by Hindering Adhesion to Host Cells.

Giardia intestinalis is a microaerophilic protozoan that is an important etiologic agent of diarrhea worldwide. There is evidence that under diverse conditions, the parasite is capable of shedding extracellular vesicles (EVs) which modulate the physiopathology of giardiasis. Here we describe new features of G. intestinalis EV production, revealing its capacity to shed two different enriched EV populations: large (LEV) and small extracellular vesicles (SEV) and identified relevant adhesion functions associated with the larger population. Proteomic analysis revealed differences in proteins relevant for virulence and host-pathogen interactions between the two EV subsets, such as cytoskeletal and anti-oxidative stress response proteins in LEVS. We assessed the effect of two recently identified inhibitors of EV release in mammalian cells, namely peptidylarginine deiminase (PAD) inhibitor and cannabidiol (CBD), on EV release from Giardia. The compounds were both able to effectively reduce EV shedding, the PAD-inhibitor specifically affecting the release of LEVs and reducing parasite attachment to host cells in vitro. Our results suggest that LEVs and SEVs have a different role in host-pathogen interaction, and that treatment with EV-inhibitors may be a novel treatment strategy for recurrent giardiasis.

Isolation and Characterization of Extracellular Vesicles Derived from Trypanosoma cruzi.

Extracellular vesicles (EVs) are heterogeneous membrane-surrounded structures that participate in cellular communications, which comprise exosomes and microvesicles. These vesicles have different biogenesis, and their physiological and pathological roles in chronic and infectious diseases are under constant investigation. In Chagas disease, Trypanosoma cruzi EVs have been described using different approaches. The isolation of T. cruzi-derived EVs has been done mainly using the differential centrifugation technique, and different strategies have been employed for characterization of them. Here, we describe the method to isolate EVs by differential centrifugation and a detection protocol for EVs in T. cruzi-host cell interaction to allow further investigations about this parasite.

Effects of Decavanadate Salts with Organic and Inorganic Cations on Escherichia coli, Giardia intestinalis, and Vero Cells.

Decavanadate salts with nicotinamide (3-pyridinecarboxamide, 3-pca) and isonicotinamide (4-pyridinecarboxamide, 4-pca) in both neutral and protonated forms, (3-Hpca)4[H2V10O28]·2H2O·2(3-pca) (complex I) and (4-Hpca)4[H2V10O28]·2(4-pca) (complex II), have been synthesized and characterized by vibrational spectroscopy (infrared and Raman), thermogravimetric analysis (TGA), 51V NMR, and single-crystal X-ray diffraction analysis. The effects of sodium decavanadate (henceforth called NaV10) and compounds I and II on Escherichia coli, Giardia intestinalis, and Vero (African green monkey epithelial kidney) cells were evaluated. Enhanced growth inhibitory activity against E. coli cultures was observed upon treatment with products I and II when compared to that with NaV10 (GI50 values of 2.8, 4.0, and 11 mmol L-1, respectively), as well as lower cell viability as measured by the intake of propidium iodide (PI). Exposure of Giardia trophozoites to NaV10 and II revealed reduction in trophozoite viability (GI50 values of ca. 10 µmol L-1) and affected the parasite adherence to both polystyrene culture tubes and a monolayer of Vero cells, even at low concentrations. A lesser effect on Giardia was shown for I. Furthermore, all three compounds were significantly less toxic to Vero cells than the reference drug, albendazole, employed in the treatment of giardiasis. Toxicity reports of oxidovanadium compounds toward Giardia are unprecedented and open a path to the development of new therapeutic agents.

A new landscape of host-protozoa interactions involving the extracellular vesicles world.

Extracellular vesicles (EVs) are released by a wide number of cells including blood cells, immune system cells, tumour cells, adult and embryonic stem cells. EVs are a heterogeneous group of vesicles (~30-1000 nm) including microvesicles and exosomes. The physiological release of EVs represents a normal state of the cell, raising a metabolic equilibrium between catabolic and anabolic processes. Moreover, when the cells are submitted to stress with different inducers or in pathological situations (malignancies, chronic diseases, infectious diseases.), they respond with an intense and dynamic release of EVs. The EVs released from stimulated cells vs those that are released constitutively may themselves differ, both physically and in their cargo. EVs contain protein, lipids, nucleic acids and biomolecules that can alter cell phenotypes or modulate neighbouring cells. In this review, we have summarized findings involving EVs in certain protozoan diseases. We have commented on strategies to study the communicative roles of EVs during host-pathogen interaction and hypothesized on the use of EVs for diagnostic, preventative and therapeutic purposes in infectious diseases. This kind of communication could modulate the innate immune system and reformulate concepts in parasitism. Moreover, the information provided within EVs could produce alternatives in translational medicine.