Algal Cells-Derived Extracellular Vesicles: A Review With Special Emphasis on Their Antimicrobial Effects

An In Vitro System Mimics the Intestinal Microbiota of Striped Beakfish (Oplegnathus fasciatus) and Inhibits Vibrio alginolyticus by Limosilactobacillus reuteri-Derived Extracellular Vesicles

Extracellular vesicles (EVs) are functional substances secreted by microbes and host cells, and it has been discovered that they participate in the interactions between different microorganisms. Our recent findings indicate that Limosilactobacillus reuteri-derived EVs have the potential to improve the intestinal microbiota of Oplegnathus fasciatus fish and inhibit pathogenic bacteria. Previous research has reported that the host intestinal cells play a regulatory role in the intestinal microbiota. This suggested that to investigate the mechanisms through which L. reuteri-derived EVs regulate the intestinal microbiota, a system that excludes interference from host intestinal cells should be established. In this study, an in vitro cultured intestinal bacteria system, without host factors, was used to simulate the intestinal microbiota of O. fasciatus fish. After adding L. reuteri-derived EVs to the system, the changes in the microbiota were analyzed. The results showed that L. reuteri-derived EVs effectively reduced the abundance of Vibrio spp. In the results of the in vitro experiments, it was also observed that L. reuteri-derived EVs have the ability to inhibit Vibrio alginolyticus. We further sequenced the small RNA contained in L. reuteri-derived EVs and found that these small RNAs can interfere with genes (LysR, pirin, MIpA/OmpV, CatB, and aspartate-semialdehyde dehydrogenase) related to the growth of V. alginolyticus. Taken together, the results indicate that in the absence of host involvement, the small RNAs present in L. reuteri-derived EVs have the function of inhibiting pathogenic bacteria and exhibit the potential to regulate the intestinal microbiota.

Comparative Proteome Profiling of Extracellular Vesicles from Three Growth Phases of Haematococcus pluvialis under High Light and Sodium Acetate Stresses

Extracellular vesicles (EVs) are nano-sized particles involved in intercellular communications that intrinsically possess many attributes as a modern drug delivery platform. Haematococcus pluvialis-derived EVs (HpEVs) can be potentially exploited as a high-value-added bioproduct during astaxanthin production. The encapsulation of HpEV cargo is a crucial key for the determination of their biological functions and therapeutic potentials. However, little is known about the composition of HpEVs, limiting insights into their biological properties and application characteristics. This study examined the protein composition of HpEVs from three growth phases of H. pluvialis grown under high light (350 µmol·m-2·s-1) and sodium acetate (45 mM) stresses. A total of 2038 proteins were identified, the majority of which were associated with biological processes including signal transduction, cell proliferation, cell metabolism, and the cell response to stress. Comparative analysis indicated that H. pluvialis cells sort variant proteins into HpEVs at different physiological states. It was revealed that HpEVs from the early growth stage of H. pluvialis contain more proteins associated with cellular functions involved in primary metabolite, cell division, and cellular energy metabolism, while HpEVs from the late growth stage of H. pluvialis were enriched in proteins involved in cell wall synthesis and secondary metabolism. This is the first study to report and compare the protein composition of HpEVs from different growth stages of H. pluvialis, providing important information on the development and production of functional microalgal-derived EVs.

Molecular mechanisms and therapeutic application of extracellular vesicles from plants

Small extracellular vesicles (sEVs) isolated from animal sources are among the most investigated types of cell-free therapeutic tools to cure different diseases. sEVs have been isolated from a variety of sources, ranging from prokaryotes to animals and plants. Human-derived sEVs have many uses in pre- and clinical studies in medicine and drug delivery, while plant-derived EVs, also known as plant-derived nanovesicles (PDNVs), have not been widely investigated until the second decade of the 21st century. For the past five years, there has been a rapid rise in the use of plant EVs as a therapeutic tool due to the ease of massive production with high efficacy and yield of preparation. Plant EVs contain various active biomolecules such as proteins, regulatory RNAs, and secondary metabolites and play a key role in inter-kingdom communications. Many studies have already investigated the potential application of plant EVs in preventing and treating cancer, inflammation, infectious diseases, and tissue regeneration with no sign of toxicity and are therefore considered safe. However, due to a lack of universal markers, the properties of plant EVs have not been extensively studied. Concerns regarding the safety and therapeutic function of plant EVs derived from genetically modified plants have been raised. In this paper, we review the physiological role of EVs in plants. Moreover, we focus on molecular and cellular mechanisms involved in the therapeutic effects of plant EVs on various human diseases. We also provide detailed information on the methodological aspects of plant EV isolation and analysis, which could pave the way for future clinical translation.

Antioxidant and anticholinesterase properties of Echinometra mathaei and Ophiocoma erinaceus venoms from the Persian Gulf

Introduction: The Persian Gulf is home to a diverse range of marine life, including various species of fish, crustaceans, mollusks, and echinoderms. This study investigates the potential therapeutic properties of venoms from echinoderms in the Persian Gulf, specifically their ability to inhibit cholinesterases (Acetylcholinesterase and butyrylcholinesterase) and act as antioxidants. Methods: Four venoms from two echinoderm species, including the spine, gonad, and coelomic fluids of sea urchins, as well as brittle star venoms, were analyzed using various methods, including LD50 determination, protein analysis, antioxidant assays, GC-MS for secondary metabolite identification, and molecular docking simulations. Results and discussion: The study's results revealed the LD50 of the samples as follows: 2.231 ± 0.09, 1.03 ± 0.05, 1.12 ± 0.13, and 6.04 ± 0.13 mg/mL, respectively. Additionally, the protein levels were 44.037 ± 0.002, 74.223 ± 0.025, 469.97 ± 0.02, and 104.407 ± 0.025 μg/mL, respectively. SDS-PAGE and total protein studies indicated that at least part of the venom was proteinaceous. Furthermore, the study found that the brittle star samples exhibited significantly higher antioxidant activity compared to other samples, including the standard ascorbic acid, at all tested concentrations. GC-MS analysis identified 12, 23, 21, and 25 compounds in the samples, respectively. These compounds had distinct chemical and bioactive structures, including alkaloids, terpenes, and steroids. Conclusion: These venoms displayed strong cholinesterase inhibitory and antioxidant activities, likely attributed to their protein content and the presence of alkaloids, terpenes, and steroids. Notably, the alkaloid compound C 7 was identified as a promising candidate for further research in Alzheimer's disease therapy. In conclusion, echinoderms in the Persian Gulf may hold significant potential for discovering novel therapeutic agents.

Plant-Derived Vesicle-Like Nanoparticles: Clinical Application Exploration and Challenges

The utilization of plant-derived vesicle-like nanoparticles (PDVLNs) has shown effectiveness in the prevention/treatment of inflammatory-mediated diseases, malignancies, and immune-related diseases, such as acute liver injury, allergic asthma, gastric cancer and so on. This highlights the promising potential of PDVLNs as biotherapeutics. Furthermore, it should be noted that PDVLNs possess the ability to function as both natural and engineered drug carriers, making them an appealing option. This review aims to present the appropriate extraction methods of PDVLNs, summarize the applications of PDVLNs in different diseases, and provide an outlook on the prospects of PDVLNs. At the same time, the authors also express their discussion on the current limitations of PDVLNs.

Reconstructed membrane vesicles from the microalga Dunaliella as a potential drug delivery system

The aim of this biophysical study is to characterize reconstructed membrane vesicles obtained from microalgae in terms of their morphology, properties, composition, and ability to transport a model drug. The reconstructed vesicles were either emptied or non-emptied and exhibited a non-uniform distribution of spherical surface structures that could be associated with surface coat proteins, while in between there were pore-like structures of up to 10 nm that could contribute to permeability. The reconstructed vesicles were very soft and hydrophilic, which could be attributed to their composition. The vesicles were rich in proteins and were mostly derived from the cytoplasm and chloroplasts. We demonstrated that all lipid classes of D. tertiolecta are involved in the formation of the reconstructed membrane vesicles, where they play fundamental role to maintain the vesicle structure. The vesicles appeared to be permeable to calcein, impermeable to FITC-ovalbumin, and semipermeable to FITC-concanavalin A, which may be due to a specific surface interaction with glucose/mannose units that could serve as a basis for the development of drug carriers. Finally, the reconstructed membrane vesicles could pave a new way as sustainable and environmentally friendly marine bioinspired carriers and serve for studies on microtransport of materials and membrane-related processes contributing to advances in life sciences and biotechnology.

The current trend of exosome in epithelial ovarian cancer studies: A bibliometric review

Background: Epithelial ovarian cancer (EOC) is the most common type of ovarian cancer. About 90% of ovary tumors are epithelial. The current treatment for EOC involves surgical debulking of the tumors followed by a combination of chemotherapy. While most patients achieve complete remission, many EOCs will recur and develop chemoresistance. The cancer cells can adapt to several stress stimuli, becoming resistant. Therefore, new ways to fight resistant cells during the disease are being studied. Recently, exosomes, which reflect cell behavior in normal and pathological conditions such as epithelial ovarian cancer, are of academic interest as new biomarkers for diagnosis and therapy. Consequently, the current study aimed to investigate the research output of exosomes in EOC.

Method: A bibliometric method was used for analyzing publications on exosome and epithelial ovarian cancer from the beginning to 15 October 2022 by searching keywords in Scopus, PubMed and Google scholar. Annual scientific publications, authors, citations, journals, co-authorships, and keywords co-occurrence were analyzed and plotted using Microsoft Office Excel and VOS viewer. 39 original journal articles and 3 reviews have been published since 2015 up to 15 October 2022.

Results: The findings showed that China is the top country in research output, international collaborations, organization, author, and sponsorship. The top journals were the Journal of Ovarian Research, Oncotarget, and Tumor Biology, all in the United States. The top institution was Shanghai Jiao Tong University in China. The top author was Xipeng Wang. Co-occurrence analysis showed that academics’ interest is toward:1) 1) Exosomes as prognostic biomarkers of EOC as well as their role in the proliferation and migration of cells. 2) The role of exosomes in metastasis through different mechanisms; 3) The role of exosomes in epithelial-mesenchymal transition of ovarian cancer cells; 4) The diagnostic role of EVs in EOC; and 5) Conferring chemoresistance in EOC through the exosomal transfer of miRNAs.

Conclusion: Research on the exosome and EOC has an increasing trend, and China is much more involved than other countries in research, financial support, and international cooperation. These findings could aid researcher in understanding novel ideas and subjects interested by sponsors in this field.

RNA-Binding Proteins as Epigenetic Regulators of Brain Functions and Their Involvement in Neurodegeneration

A central aspect of nervous system development and function is the post-transcriptional regulation of mRNA fate, which implies time- and site-dependent translation, in response to cues originating from cell-to-cell crosstalk. Such events are fundamental for the establishment of brain cell asymmetry, as well as of long-lasting modifications of synapses (long-term potentiation: LTP), responsible for learning, memory, and higher cognitive functions. Post-transcriptional regulation is in turn dependent on RNA-binding proteins that, by recognizing and binding brief RNA sequences, base modifications, or secondary/tertiary structures, are able to control maturation, localization, stability, and translation of the transcripts. Notably, most RBPs contain intrinsically disordered regions (IDRs) that are thought to be involved in the formation of membrane-less structures, probably due to liquid-liquid phase separation (LLPS). Such structures are evidenced as a variety of granules that contain proteins and different classes of RNAs. The other side of the peculiar properties of IDRs is, however, that, under altered cellular conditions, they are also prone to form aggregates, as observed in neurodegeneration. Interestingly, RBPs, as part of both normal and aggregated complexes, are also able to enter extracellular vesicles (EVs), and in doing so, they can also reach cells other than those that produced them.

The Emerging Role of Plant-Derived Exosomes-Like Nanoparticles in Immune Regulation and Periodontitis Treatment

Periodontitis is an infectious oral disease, which leads to the destruction of periodontal tissues and tooth loss. Although the treatment of periodontitis has improved recently, the effective treatment of periodontitis and the periodontitis-affected periodontal tissues is still a challenge. Therefore, it is urgent to explore new therapeutic strategies for periodontitis. Natural products show anti-microbial, anti-inflammatory, anti-oxidant and bone protective effects to periodontitis and most of these natural products are safe and cost-effective. Among these, the plant-derived exosome-like nanoparticles (PELNs), a type of natural nanocarriers repleted with lipids, proteins, RNAs, and other active molecules, show the ability to enter mammalian cells and regulate cellular activities. Reports from the literature indicate the great potential of PELNs in the regulation of immune functions, inflammation, microbiome, and tissue regeneration. Moreover, PELNs can also be used as drug carriers to enhance drug stability and cellular uptake in vivo. Since regulation of immune function, inflammation, microbiome, and tissue regeneration are the key phenomena usually targeted during periodontitis treatment, the PELNs hold the promising potential for periodontitis treatment. This review summarizes the recent advances in PELNs-related research that are related to the treatment of periodontitis and regeneration of periodontitis-destructed tissues and the underlying mechanisms. We also discuss the existing challenges and prospects of the application of PELNs-based therapeutic approaches for periodontitis treatment.