Extracellular Vesicles: Emerging Players in Plant Defense Against Pathogens

[Anti-skin Aging Effects of Kale-derived Exosome-like Nanoparticles]

In an aging society, there is a growing interest in functional foods that offer anti-aging benefits. Food-derived bioactive compounds such as carotenoids and polyphenols can enhance skin elasticity and delay aging. However, the mechanisms by which these orally ingested compounds directly impact the skin are not fully understood. Recent studies on exosomes have suggested significant physiological functions, including their potential for intercellular communication. Similar to mammalian exosomes, plant-derived exosomes are known for their functional roles, including cross-kingdom communication, and their ability to target specific organs in animal models as delivery vehicles. The authors have been investigating the anti-aging effects of kale and have previously reported its benefits on cognitive function and skin aging in mouse models. Long-term oral administration of glucoraphanin-enriched kale suppresses the senescence symptoms in skin and hair and increases type I collagen and antioxidant enzyme expression in skin tissues, indicating its role in promoting skin health. Exosome-like nanoparticles (ELNs) from glucoraphanin-enriched kale appear to modulate the expression of extracellular matrix-related genes. Kale-derived ELNs exhibit great potential for ameliorating skin aging, suggesting their ability to promote skin health through targeted cellular mechanisms and supporting their use as an active natural compound in nutraceuticals and functional beverages.

Leveraging RNA interference technology for selective and sustainable crop protection

Double-stranded RNA (dsRNA) has emerged as key player in gene silencing for the past two decades. Tailor-made dsRNA is now recognized a versatile raw material, suitable for a wide range of applications in biopesticide formulations, including insect control to pesticide resistance management. The mechanism of RNA interference (RNAi) acts at the messenger RNA (mRNA) level, utilizing a sequence-dependent approach that makes it unique in term of effectiveness and specificity compared to conventional agrochemicals. Two primary categories of small RNAs, known as short interfering RNAs (siRNAs) and microRNAs (miRNAs), function in both somatic and germline lineages in a broad range of eukaryotic species to regulate endogenous genes and to defend the genome from invasive nucleic acids. Furthermore, the application of RNAi in crop protection can be achieved by employing plant-incorporated protectants through plant transformation, but also by non-transformative strategies such as the use of formulations of sprayable RNAs as direct control agents, resistance factor repressors or developmental disruptors. This review explores the agricultural applications of RNAi, delving into its successes in pest-insect control and considering its broader potential for managing plant pathogens, nematodes, and pests. Additionally, the use of RNAi as a tool for addressing pesticide-resistant weeds and insects is reviewed, along with an evaluation of production costs and environmental implications.

Subcellular spatial regulation of immunity-induced phosphorylation of RIN4 links PAMP-triggered immunity to Exo70B1

RIN4 is a crucial regulator of plant immunity, playing a role in both PAMP-triggered immunity (PTI) and effector-triggered immunity (ETI). While the impact of post-translational modifications (PTMs) on RIN4 has been extensively studied, their specific effects on plant immune response regulation and the underlying mechanisms have remained unclear. In this study, we investigated the phosphorylation of RIN4 at threonine-166 (RIN4T166) in Arabidopsis transgenic lines expressing various RIN4 variants. Our pathological and molecular genetic analyses reveal that RIN4T166 phosphorylation disrupts its localization to the plasma membrane (PM) and represses plant defense activation. We found that RIN4's PM tethering relies on Exo70B1-mediated exocytosis and the integrity of the host cytoskeletal actin network. Phosphorylation at RIN4T166 disrupts its PM localization due to reduced binding affinity with Exo70B1. This disruption was further evidenced by the 35S::RIN4T166D/rin124 transgenic line, which exhibited suppressed PTI responses similar to the exo70b1 mutant. Our findings demonstrate that RIN4's subcellular localization is regulated by phosphorylation, suggesting that plants use a sophisticated network of signaling processes to precisely control the timing and localization of immune signaling activation. This study uncovers a mechanism by which PTI is repressed through RIN4 phosphorylation, providing new insights into the spatial regulation of RIN4 within plant immune signaling pathways.

Engineering Strategies of Plant-Derived Exosome-Like Nanovesicles: Current Knowledge and Future Perspectives

Plant-derived exosome-like nanovesicles (PELNs) from edible plants, isolated by ultracentrifugation, size exclusion chromatography or other methods, were proved to contain a variety of biologically active and therapeutically specific components. Recently, investigations in the field of PELN-based biomedicine have been conducted, which positioned those nanovesicles as promising tools for prevention and treatment of several diseases, with their natural origin potentially offering superior biocompatibility and bioavailability. However, the inadequate targeting and limited therapeutic effects constrain the utility and clinical translation of PELNs. Thus, strategies aiming at bridging the gap by engineering natural PELNs have been of great interest. Those approaches include membrane hybridization, physical and chemical surface functionalization and encapsulation of therapeutic payloads. Herein, we provide a comprehensive overview of the biogenesis and composition, isolation and purification methods and characterization of PELNs, as well as their therapeutic functions. Current knowledge on the construction strategies and biomedical application of engineered PELNs were reviewed. Additionally, future directions and perspectives in this field were discussed in order to further enrich and expand the prospects for the application of engineered PELNs.

Interkingdom Communication via Extracellular Vesicles: Unraveling Plant and Pathogen Interactions and Its Potential for Next-Generation Crop Protection

Recent advancements in the field of plant-pathogen interactions have spotlighted the role of extracellular vesicles (EVs) as pivotal mediators of cross-kingdom communication, offering new vistas for enhancing crop protection strategies. EVs are instrumental in the transport of small regulatory RNAs (sRNAs) and other bioactive molecules across species boundaries, thus playing a critical role in the molecular warfare between plants and pathogens. This review elucidates the sophisticated mechanisms by which plants utilize EVs to dispatch sRNAs that silence pathogenic genes, fortifying defenses against microbial threats. Highlighting both eukaryotic and prokaryotic systems, this review delves into the biogenesis, isolation, and functional roles of EVs, illustrating their importance not only in fundamental biological processes but also in potential therapeutic applications. Recent studies have illuminated the significant role of EVs in facilitating communication between plants and pathogens, highlighting their potential in host-defense mechanisms. However, despite these advancements, challenges remain in the efficient isolation and characterization of plant-derived EVs. Overcoming these challenges is critical for fully harnessing their potential in developing next-generation crop protection strategies. This review proposes innovative strategies for utilizing RNA-based interventions delivered via EVs to bolster plant resilience against diseases. By integrating the latest scientific findings with practical applications in agriculture, this review aims to enhance the connection between fundamental plant biology and the development of innovative crop management technologies.

Cross-Kingdom RNA Transport Based on Extracellular Vesicles Provides Innovative Tools for Plant Protection

RNA interference (RNAi) shows great potential in plant defense against pathogens through RNA-mediated sequence-specific gene silencing. Among RNAi-based plant protection strategies, spray-induced gene silencing (SIGS) is considered a more promising approach because it utilizes the transfer of exogenous RNA between plants and microbes to silence target pathogen genes. The application of nanovesicles significantly enhances RNA stability and delivery efficiency, thereby improving the effectiveness of SIGS and further enhancing plant resistance to diseases and pathogens. This review explores the role of RNAi in plant protection, focusing on the cross-kingdom transport of small RNAs (sRNAs) via extracellular vesicles. It also explores the potential of nanotechnology to further optimize RNA-based plant protection, offering innovative tools and methods in modern plant biotechnology.

Exosome-like Nanoparticles, High in Trans-δ-Viniferin Derivatives, Produced from Grape Cell Cultures: Preparation, Characterization, and Anticancer Properties

Background: Recent interest in plant-derived exosome-like nanoparticles (ENs) has surged due to their therapeutic potential, which includes antioxidant, anti-inflammatory, and anticancer activities. These properties are attributed to their cargo of bioactive metabolites and other endogenous molecules. However, the properties of ENs isolated from plant cell cultures remain less explored. Methods: In this investigation, grape callus-derived ENs (GCENs) were isolated using differential ultracentrifugation techniques. Structural analysis through electron microscopy, nanoparticle tracking analysis, and western blotting confirmed that GCENs qualify as exosome-like nanovesicles. Results: These GCENs contained significant amounts of microRNAs and proteins characteristic of plant-derived ENs, as well as trans-δ-viniferin, a notable stilbenoid known for its health-promoting properties. Functional assays revealed that the GCENs reduced the viability of the triple-negative breast cancer cell line MDA-MB-231 in a dose-dependent manner. Moreover, the GCENs exhibited negligible effects on the viability of normal human embryonic kidney (HEK) 293 cells, indicating selective cytotoxicity. Notably, treatment with these GCENs led to cell cycle arrest in the G1 phase and triggered apoptosis in the MDA-MB-231 cell line. Conclusions: Overall, this study underscores the potential of grape callus-derived nanovectors as natural carriers of stilbenoids and proposes their application as a novel and effective approach in the management of cancer.

Plant Defense Mechanisms against Polycyclic Aromatic Hydrocarbon Contamination: Insights into the Role of Extracellular Vesicles

Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants that pose significant environmental and health risks. These compounds originate from both natural phenomena, such as volcanic activity and wildfires, and anthropogenic sources, including vehicular emissions, industrial processes, and fossil fuel combustion. Their classification as carcinogenic, mutagenic, and teratogenic substances link them to various cancers and health disorders. PAHs are categorized into low-molecular-weight (LMW) and high-molecular-weight (HMW) groups, with HMW PAHs exhibiting greater resistance to degradation and a tendency to accumulate in sediments and biological tissues. Soil serves as a primary reservoir for PAHs, particularly in areas of high emissions, creating substantial risks through ingestion, dermal contact, and inhalation. Coastal and aquatic ecosystems are especially vulnerable due to concentrated human activities, with PAH persistence disrupting microbial communities, inhibiting plant growth, and altering ecosystem functions, potentially leading to biodiversity loss. In plants, PAH contamination manifests as a form of abiotic stress, inducing oxidative stress, cellular damage, and growth inhibition. Plants respond by activating antioxidant defenses and stress-related pathways. A notable aspect of plant defense mechanisms involves plant-derived extracellular vesicles (PDEVs), which are membrane-bound nanoparticles released by plant cells. These PDEVs play a crucial role in enhancing plant resistance to PAHs by facilitating intercellular communication and coordinating defense responses. The interaction between PAHs and PDEVs, while not fully elucidated, suggests a complex interplay of cellular defense mechanisms. PDEVs may contribute to PAH detoxification through pollutant sequestration or by delivering enzymes capable of PAH degradation. Studying PDEVs provides valuable insights into plant stress resilience mechanisms and offers potential new strategies for mitigating PAH-induced stress in plants and ecosystems.

Identification of mungbean yellow mosaic India virus and susceptibility-related metabolites in the apoplast of mung bean leaves

KEY MESSAGE

The investigation of MYMIV-infected mung bean leaf apoplast revealed viral genome presence, increased EVs secretion, and altered stress-related metabolite composition, providing comprehensive insights into plant-virus interactions. The apoplast, an extracellular space around plant cells, plays a vital role in plant-microbe interactions, influencing signaling, defense, and nutrient transport. While the involvement of apoplast and extracellular vesicles (EVs) in RNA virus infection is documented, the role of the apoplast in plant DNA viruses remains unclear. This study explores the apoplast's role in mungbean yellow mosaic India virus (MYMIV) infection. Our findings demonstrate the presence of MYMIV genomic components in apoplastic fluid, suggesting potential begomovirus cell-to-cell movement via the apoplast. Moreover, MYMIV infection induces increased EVs secretion into the apoplast. NMR-based metabolomics reveals altered metabolic profiles in both apoplast and symplast in response to MYMIV infection, highlighting key metabolites associated with stress and defense mechanisms. The data show an elevation of α- and β-glucose in both apoplast and symplast, suggesting a shift in glucose utilization. Interestingly, this increase in glucose does not contribute to the synthesis of phenolic compounds, potentially influencing the susceptibility of mung bean to MYMIV. Fructose levels increase in the symplast, while apoplastic sucrose levels rise significantly. Symplastic aspartate levels increase, while proline exhibits elevated concentration in the apoplast and reduced concentration in the cytosol, suggesting a role in triggering a hypersensitive response. These findings underscore the critical role of the apoplast in begomovirus infection, providing insights for targeted viral disease management strategies.

Extracellular Vesicles from Ecklonia cava and Phlorotannin Promote Rejuvenation in Aged Skin

Plant-derived extracellular vesicles (EVs) elicit diverse biological effects, including promoting skin health. EVs isolated from Ecklonia cava (EV-EC) carry heat shock protein 70 (HSP70), which inhibits key regulators such as TNF-α, MAPKs, and NF-κB, consequently downregulating matrix metalloproteinases (MMPs). Aging exacerbates oxidative stress, upregulating MAPK and NF-κB signaling and worsening extracellular matrix degradation in the skin. E. cava-derived phlorotannin (PT) mitigates MAPK and NF-κB signaling. We evaluated the impact of EV-EC and PT on skin rejuvenation using an in vitro keratinocyte senescence model and an in vivo aged-mouse model. Western blotting confirmed the presence of HSP70 in EV-EC. Treatment with EV-EC and PT in senescent keratinocytes increased HSP70 expression and decreased the expression of TNF-α, MAPK, NF-κB, activator protein-1 (AP-1), and MMPs. Oxidative stress was also reduced. Sequential treatment with PT and EV-EC (PT/EV-EC) yielded more significant results compared to individual treatments. The administration of PT/EV-EC to the back skin of aged mice mirrored the in vitro findings, resulting in increased collagen fiber accumulation and improved elasticity in the aged skin. Therefore, PT/EV-EC holds promise in promoting skin rejuvenation by increasing HSP70 expression, decreasing the expression of MMPs, and reducing oxidative stress in aged skin.

Plant-Derived Vesicle-like Nanoparticles: The Next-Generation Drug Delivery Nanoplatforms

A wide variety of natural bioactive compounds derived from plants have demonstrated significant clinical relevance in the treatment of various diseases such as cancer, chronic disease, and inflammation. An increasing number of studies have surfaced that give credence to the potential of plant-derived vesicle-like nanoparticles (PDVLNs) as compelling candidates for a drug delivery system (DDS). PDVLNs are cost-effective production, non-toxicity and non-immunogenicity and fascinating bi-ocompatibility. In this review, we attempt to comprehensively review and consolidate the position of PDVLNs as next-generation drug delivery nanoplatforms. We aim to give a quick glance to readers of the current developments of PDVLNs, including their biogenesis, characteristic features, composition, administration routes, advantages, and application. Further, we discuss the advantages and limitations of PDVLNs. We expect that the role of PDVLNs in drug delivery will be significantly enhanced, thus positioning them as the next generation of therapeutic modalities in the foreseeable future.

Milk Extracellular Vesicles: Natural Nanoparticles for Enhancing Oral Drug Delivery against Bacterial Infections

Oral drug delivery is typically preferred as a therapeutic intervention due to the complexities and expenses associated with intravenous administration. However, some drugs are poorly absorbed orally, requiring intravenous administration to bypass the gastrointestinal tract and deliver the drug directly into the bloodstream. Thus, there is an urgent need to develop novel drug delivery platforms to overcome the challenges of oral drug delivery with low solubility, low permeability, oral degradation, and low bioavailability. Advances in extracellular vesicles (EVs) as natural carriers have provided emerging approaches to improve potential therapeutic applications. Milk not only contains traditional nutrients but is also rich in EVs. In this Review, we focus mainly on the purification of milk EVs (mEVs), their safety, and the advantages of mEV-based drug carriers in combatting intestinal infections. Additionally, we summarize several advantages of mEVs over conventional synthetic carriers, such as low immunogenicity, high biocompatibility, and the ability to transfer bioactive molecules between cells. Considering the unmet gaps of mEVs in clinical translation, it is essential to review the cargo loading into mEVs and future perspectives for their use as natural drug carriers for oral delivery. This overview of mEV-based drug carriers for oral delivery sheds light on alternative approaches to treat clinical infections associated with intestinal pathogens and the development of novel oral delivery systems.

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.

The extracellular vesicle proteomes of Sorghum bicolor and Arabidopsis thaliana are partially conserved

Plant extracellular vesicles (EVs) are membrane-bound organelles involved mainly in intercellular communications and defense responses against pathogens. Recent studies have demonstrated the presence of proteins, nucleic acids including small RNAs, and lipids along with other metabolites in plant EVs. Here, we describe the isolation and characterization of EVs from sorghum (Sorghum bicolor). Nanoparticle tracking analysis, dynamic light scattering, and cryo-electron tomography showed the presence of a heterogeneous population of EVs isolated from the apoplastic wash of sorghum leaves. Cryo-electron microscopy revealed that EVs had a median size of 110 nm and distinct populations of vesicles with single or multiple lipid bilayers and low or high amounts of contents. The heterogeneity was further supported by data showing that only a subset of EVs that were stained with a membrane dye, Potomac Gold, were also stained with the membrane-permeant esterase-dependent dye, calcein acetoxymethyl ester. Proteomic analysis identified 437 proteins that were enriched in multiple EV isolations, with the majority of these also found in the EV proteome of Arabidopsis (Arabidopsis thaliana). These data suggest a partial conservation of EV contents and function between the monocot, sorghum, and a distantly related eudicot, Arabidopsis.

Engineered plant extracellular vesicles for natural delivery across physiological barriers

Extracellular vesicles (EVs) are nanoscale luminal vesicles that participate in the information transfer of proteins, nucleic acids, and lipids between cells, thereby playing a role in the treatment of diseases and the delivery of nutrients. In recent years, plant-derived EVs (PDEVs) containing bioactive compounds have attracted increasing interest due to their better biocompatibility and lower cytotoxicity in healthy tissues. In the biomedical field, PDEVs have been used as cargo carriers to achieve various functions through engineering modification techniques. This review focuses on the biogenesis, isolation, and identification of PDEVs. We discuss the surface functionalization of PDEVs to enhance therapeutic efficacy, thereby improving their efficiency as a next-generation drug delivery vehicle and their feasibility to treat diseases across the physiological barriers, while critically analyzing the current challenges and opportunities.

Synergistic vesicle-vector systems for targeted delivery

With the immense progress in drug delivery systems (DDS) and the rise of nanotechnology, challenges such as target specificity remain. The vesicle-vector system (VVS) is a delivery system that uses lipid-based vesicles as vectors for a targeted drug delivery. When modified with target-probing materials, these vesicles become powerful vectors for drug delivery with high target specificity. In this review, we discuss three general types of VVS based on different modification strategies: (1) vesicle-probes; (2) vesicle-vesicles; and (3) genetically engineered vesicles. The synthesis of each VVS type and their corresponding properties that are advantageous for targeted drug delivery, are also highlighted. The applications, challenges, and limitations of VVS are briefly examined. Finally, we share a number of insights and perspectives regarding the future of VVS as a targeted drug delivery system at the nanoscale.

Nanoscale Phytosomes as an Emerging Modality for Cancer Therapy

Extracellular vesicle (EV) research has expanded substantially over the years. EVs have been identified in all living organisms and are produced and released as a means of intercellular communication or as a defense mechanism. Recently, nano-scaled vesicles were successfully isolated from edible plant sources. Plant-derived EVs, referred to here as phytosomes, are of a size reported to range between 30 nm and 120 nm in diameter, similar to small mammalian extracellular vesicles, and carry various bioactive molecules such as mRNA, proteins, miRNA and lipids. Due to the availability of many plants, phytosomes can be easily isolated on a large scale. The methods developed for EV isolation from mammalian cells have been successfully applied for isolation and purification of phytosomes. The therapeutic effects of phytosomes on different disease models, such as inflammation and autoimmune disease, have been reported, and a handful of studies have suggested their therapeutic effects on cancer diseases. Overall, the research on phytosomes is still in its infancy and requires more exploration. This review will narrate the anti-cancer activity and characteristics of phytosomes derived from edible plants as well as describe studies which have utilized phytosomes as drug delivery vehicles for cancer with the ultimate objective of significantly reducing the adverse effects associated with conventional therapeutic approaches.

Zingiber officinale-Derived Extracellular Vesicles Attenuate Bleomycin-Induced Pulmonary Fibrosis Trough Antioxidant, Anti-Inflammatory and Protease Activity in a Mouse Model

Idiopathic pulmonary fibrosis (IPF) is the most frequent and severe idiopathic interstitial pneumonia. It is a chronic and progressive disease with a poor prognosis and is a major cause of morbidity and mortality. This disease has no cure; therefore, there is a clinical need to search for alternative treatments with greater efficacy. In this study, we aimed to evaluate the effect of extracellular vesicles (EVs) from Zingiber officinale (EVZO) in a murine model of bleomycin (BLM)-induced IPF administered through an osmotic minipump. EVZO had an average size of 373 nm and a spherical morphology, as identified by scanning electron microscopy. Label-free proteomic analysis of EVZOs was performed by liquid chromatography coupled to mass spectrometry, and 20 proteins were identified. In addition, we demonstrated the protease activity of EVZO by gelatin-degrading zymography assay and the superoxide dismutase (SOD) activity of EVZO by an enzymatic assay. In the BLM-induced IPF mouse model, nasal administration of 50 μg of EVZO induced recovery of alveolar space size and decreased cellular infiltrate, collagen deposition, and expression of α-SMA-positive cells. Additionally, EVZO inhibited inflammatory markers such as iNOS and COX-2, lipid peroxidation, and apoptotic cells. These results show that EVZO may represent a novel natural delivery mechanism to treat IPF.

Plant Exosome-like Nanovesicles and Their Role in the Innovative Delivery of RNA Therapeutics

Exosomes are single membrane-bound spheres released from cells carrying complex cargoes, including lipids, proteins, and nucleic acids. Exosomes transfer specific cargoes from donor to acceptor cells, playing important roles in cell-to-cell communication. Current studies have reported that plant exosomes are prominent in transferring small RNA between host and pathogens in a cross-kingdom manner. Plant exosomes are excellent RNA interference (RNAi) delivery agents with similar physical and chemical properties to mammalian exosomes and have potential applications in therapeutic delivery systems. Recent data have suggested that plant exosome-like nanovesicles (PENVs) and artificial PENV-derived nano-vectors (APNVs) are beneficial for delivering therapeutic small RNA in mammalian systems and exhibit excellent competitiveness in future clinical applications. This review features their preparation methods, composition, roles in small RNA delivery for health functionalities, and their potency as functional nanomedicine.

Pathogen-Derived Extracellular Vesicles: Emerging Mediators of Plant-Microbe Interactions

Extracellular vesicles (EVs) are lipid bilayer-enclosed nanoparticles that deliver bioactive proteins, nucleic acids, lipids, and other small molecules from donor to recipient cells. They have attracted significant interest recently due to their important roles in regulating plant-microbe interaction. During microbial infection, plant EVs play a prominent role in defense by delivering small regulatory RNA into pathogens, resulting in the silencing of pathogen virulence genes. Pathogens also deliver small RNAs into plant cells to silence host immunity genes. Recent evidence indicates that microbial EVs may be involved in pathogenesis and host immunity modulation by transporting RNAs and other biomolecules. However, the biogenesis and function of microbial EVs in plant-microbe interaction remain ill-defined. In this review, we discuss various aspects of microbial EVs, with a particular focus on current methods for EV isolation, composition, biogenesis, and their roles in plant-microbe interaction. We also discussed the potential role of microbial EVs in cross-kingdom RNA trafficking from pathogens to plants, as it is a highly likely possibility to explore in the future. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Plant-Derived Exosome-like Nanoparticles for Biomedical Applications and Regenerative Therapy

Plant-derived exosome-like nanoparticles (PDENs) comprise various bioactive biomolecules. As an alternative cell-free therapeutic approach, they have the potential to deliver nano-bioactive compounds to the human body, and thus lead to various anti-inflammatory, antioxidant, and anti-tumor benefits. Moreover, it is known that Indonesia is one of the herbal centers of the world, with an abundance of unexplored sources of PDENs. This encouraged further research in biomedical science to develop natural richness in plants as a source for human welfare. This study aims to verify the potential of PDENs for biomedical purposes, especially for regenerative therapy applications, by collecting and analyzing data from the latest relevant research and developments.

The role of extracellular vesicles in intercellular communication in human reproduction

Embryo-maternal cross-talk has emerged as a vitally important process for embryo development and implantation, which is driven by secreted factors and extracellular vesicles (EVs). The EV cargo of bioactive molecules significantly influences target cells and primes them for critical stages of reproductive biology, including embryo development, adhesion, and implantation. Recent research has suggested that EVs and their cargo represent a powerful non-invasive tool that can be leveraged to assess embryo and maternal tissue quality during assisted reproduction treatments. Here, we review the current scientific literature regarding the intercellular cross-talk between embryos and maternal tissues from fertilization to implantation, focusing on human biology and signaling mechanisms identified in animal models.

Fungal Secondary Metabolites and Small RNAs Enhance Pathogenicity during Plant-Fungal Pathogen Interactions

Fungal plant pathogens use proteinaceous effectors as well as newly identified secondary metabolites (SMs) and small non-coding RNA (sRNA) effectors to manipulate the host plant's defense system via diverse plant cell compartments, distinct organelles, and many host genes. However, most molecular studies of plant-fungal interactions have focused on secreted effector proteins without exploring the possibly equivalent functions performed by fungal (SMs) and sRNAs, which are collectively known as "non-proteinaceous effectors". Fungal SMs have been shown to be generated throughout the plant colonization process, particularly in the early biotrophic stages of infection. The fungal repertoire of non-proteinaceous effectors has been broadened by the discovery of fungal sRNAs that specifically target plant genes involved in resistance and defense responses. Many RNAs, particularly sRNAs involved in gene silencing, have been shown to transmit bidirectionally between fungal pathogens and their hosts. However, there are no clear functional approaches to study the role of these SM and sRNA effectors. Undoubtedly, fungal SM and sRNA effectors are now a treasured land to seek. Therefore, understanding the role of fungal SM and sRNA effectors may provide insights into the infection process and identification of the interacting host genes that are targeted by these effectors. This review discusses the role of fungal SMs and sRNAs during plant-fungal interactions. It will also focus on the translocation of sRNA effectors across kingdoms, the application of cross-kingdom RNA interference in managing plant diseases and the tools that can be used to predict and study these non-proteinaceous effectors.

Plant-derived extracellular vesicles: Recent advancements and current challenges on their use for biomedical applications

Extracellular vesicles (EVs) represent a diverse class of lipid bilayer membrane vesicles released by both animal and plant cells. These ubiquitous vesicles are involved in intercellular communication and transport of various biological cargos, including proteins, lipids, and nucleic acids. In recent years, interest in plant-derived EVs has increased tremendously, as they serve as a scalable and sustainable alternative to EVs derived from mammalian sources. In vitro and in vivo findings have demonstrated that these plant-derived vesicles (PDVs) possess intrinsic therapeutic activities that can potentially treat diseases and improve human health. In addition, PDVs can also act as efficient and biocompatible drug carriers. While preclinical studies have shown promising results, there are still several challenges and knowledge gaps that have to be addressed for the successful translation of PDVs into clinical applications, especially in view of the lack of standardised protocols for material handling and PDV isolation from various plant sources. This review provides the readers with a quick overview of the current understanding and research on PDVs, critically analysing the current challenges and highlighting the immense potential of PDVs as a novel class of therapeutics to treat human diseases. It is expected that this work will guide scientists to address the knowledge gaps currently associated with PDVs and promote new advances in plant-based therapeutic solutions.

Immunomodulatory effect of extracellular vesicles from Entamoeba histolytica trophozoites: Regulation of NETs and respiratory burst during confrontation with human neutrophils

Parasites release extracellular vesicles (EVs) which, in some cases, modulate the host's immune response contributing to the establishment of the infection. In this work we have isolated and characterized the EVs released by trophozoites of the human protozoan parasite Entamoeba histolytica, the causal agent of amoebiasis, when alone or in coculture with human neutrophils, and determined their effect on neutrophil NETs and ROS production. Nanoparticle tracking analysis showed that amoebic EVs are variable in size, ranging from less than 50 nm to nearly 600 nm in diameter (average of 167 nm), whereas neutrophil EVs are more uniform in size, with an average of 136 nm. In cocultures amoeba:neutrophil (1:100) most EVs are 98 nm in size, which is the typical size of exosomes. EVs from amoebae and neutrophils showed almost equal levels of ROS, which were considerably increased in EVs from cocultures. Uptake of amoebic EVs by neutrophils was demonstrated by fluorescence and resulted in a significant reduction in the oxidative burst and NET release triggered by PMA, ionophore A23187, or the amoebae itself used as stimuli. Interestingly, uptake of EVs from cocultures did not affect ROS production, but instead caused a greater delay in the onset of NETs release and in their quantity. A comparative proteomic analysis between the EVs of amoebae and neutrophils separately vs the cocultures showed a similar distribution of protein categories in the GO analysis, but differences in the expression and abundance of proteins such as the N-acetyl-D-galactosamine (GalNAc) inhibitable surface lectin and calreticulin in amoeba EVs, and various antimicrobial molecules in neutrophil EVs, such as lactoferrin and myeloperoxidase. These results highlight the importance of EVs in the immunomodulatory effects exerted by amoeba on human neutrophils.

Immunological Effects of Aster yomena Callus-Derived Extracellular Vesicles as Potential Therapeutic Agents against Allergic Asthma

Plant-derived extracellular vesicles, (EVs), have recently gained attention as potential therapeutic candidates. However, the varying properties of plants that are dependent on their growth conditions, and the unsustainable production of plant-derived EVs hinder drug development. Herein, we analyzed the secondary metabolites of Aster yomena callus-derived EVs (AYC-EVs) obtained via plant tissue cultures and performed an immune functional assay to assess the potential therapeutic effects of AYC-EVs against inflammatory diseases. AYC-EVs, approximately 225 nm in size, were isolated using tangential flow filtration (TFF) and cushioned ultracentrifugation. Metabolomic analysis, using ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF/MS), revealed that AYC-EVs contained 17 major metabolites. AYC-EVs inhibited the phenotypic and functional maturation of LPS-treated dendritic cells (DCs). Furthermore, LPS-treated DCs exposed to AYC-EVs showed decreased immunostimulatory capacity during induction of CD4+ and CD8+ T-cell proliferation and activation. AYC-EVs inhibited T-cell reactions associated with the etiology of asthma in asthmatic mouse models and improved various symptoms of asthma. This regulatory effect of AYC-EVs resembled that of dexamethasone, which is currently used to treat inflammatory diseases. These results provide a foundation for the development of plant-derived therapeutic agents for the treatment of various inflammatory diseases, as well as providing an insight into the possible mechanisms of action of AYC-EVs.

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.

CRISPR/Cas- and Topical RNAi-Based Technologies for Crop Management and Improvement: Reviewing the Risk Assessment and Challenges Towards a More Sustainable Agriculture

Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated gene (Cas) system and RNA interference (RNAi)-based non-transgenic approaches are powerful technologies capable of revolutionizing plant research and breeding. In recent years, the use of these modern technologies has been explored in various sectors of agriculture, introducing or improving important agronomic traits in plant crops, such as increased yield, nutritional quality, abiotic- and, mostly, biotic-stress resistance. However, the limitations of each technique, public perception, and regulatory aspects are hindering its wide adoption for the development of new crop varieties or products. In an attempt to reverse these mishaps, scientists have been researching alternatives to increase the specificity, uptake, and stability of the CRISPR and RNAi system components in the target organism, as well as to reduce the chance of toxicity in nontarget organisms to minimize environmental risk, health problems, and regulatory issues. In this review, we discuss several aspects related to risk assessment, toxicity, and advances in the use of CRISPR/Cas and topical RNAi-based technologies in crop management and breeding. The present study also highlights the advantages and possible drawbacks of each technology, provides a brief overview of how to circumvent the off-target occurrence, the strategies to increase on-target specificity, the harm/benefits of association with nanotechnology, the public perception of the available techniques, worldwide regulatory frameworks regarding topical RNAi and CRISPR technologies, and, lastly, presents successful case studies of biotechnological solutions derived from both technologies, raising potential challenges to reach the market and being social and environmentally safe.

Plant-RNA in Extracellular Vesicles: The Secret of Cross-Kingdom Communication

The release of extracellular vesicles (EVs) is a common language, used by living organisms from different kingdoms as a means of communication between them. Extracellular vesicles are lipoproteic particles that contain many biomolecules, such as proteins, nucleic acids, and lipids. The primary role of EVs is to convey information to the recipient cells, affecting their function. Plant-derived extracellular vesicles (PDEVs) can be isolated from several plant species, and the study of their biological properties is becoming an essential starting point to study cross-kingdom communication, especially between plants and mammalians. Furthermore, the presence of microRNAs (miRNAs) in PDEVs represents an interesting aspect for understanding how PDEVs can target the mammalian genes involved in pathological conditions such as cancer, inflammation, and oxidative stress. In particular, this review focuses on the history of PDEVs, from their discovery, to purification from various matrices, and on the functional role of PDEV-RNAs in cross-kingdom interactions. It is worth noting that miRNAs packaged in PDEVs can be key modulators of human gene expression, representing potential therapeutic agents.

Elaboration of a Phytoremediation Strategy for Successful and Sustainable Rehabilitation of Disturbed and Degraded Land

Humans are dependent upon soil which supplies food, fuel, chemicals, medicine, sequesters pollutants, purifies and conveys water, and supports the built environment. In short, we need soil, but it has little or no need of us. Agriculture, mining, urbanization and other human activities result in temporary land-use and once complete, used and degraded land should be rehabilitated and restored to minimize loss of soil carbon. It is generally accepted that the most effective strategy is phyto-remediation. Typically, phytoremediation involves re-invigoration of soil fertility, physicochemical properties, and its microbiome to facilitate establishment of appropriate climax cover vegetation. A myco-phytoremediation technology called Fungcoal was developed in South Africa to achieve these outcomes for land disturbed by coal mining. Here we outline the contemporary and expanded rationale that underpins Fungcoal, which relies on in situ bio-conversion of carbonaceous waste coal or discard, in order to explore the probable origin of humic substances (HS) and soil organic matter (SOM). To achieve this, microbial processing of low-grade coal and discard, including bio-liquefaction and bio-conversion, is examined in some detail. The significance, origin, structure, and mode of action of coal-derived humics are recounted to emphasize the dynamic equilibrium, that is, humification and the derivation of soil organic matter (SOM). The contribution of plant exudate, extracellular vesicles (EV), extra polymeric substances (EPS), and other small molecules as components of the dynamic equilibrium that sustains SOM is highlighted. Arbuscular mycorrhizal fungi (AMF), saprophytic ectomycorrhizal fungi (EMF), and plant growth promoting rhizobacteria (PGPR) are considered essential microbial biocatalysts that provide mutualistic support to sustain plant growth following soil reclamation and restoration. Finally, we posit that de novo synthesis of SOM is by specialized microbial consortia (or ‘humifiers’) which use molecular components from the root metabolome; and, that combinations of functional biocatalyst act to re-establish and maintain the soil dynamic. It is concluded that a bio-scaffold is necessary for functional phytoremediation including maintenance of the SOM dynamic and overall biogeochemistry of organic carbon in the global ecosystem