Characterizing Extracellular Vesicles and Their Diverse RNA Contents

Therapeutic potential of mesenchymal stem cell-derived exosomes as a cell-free therapy approach for the treatment of skin, bone, and cartilage defects

OBJECTIVE

The aim of this study was to collect the articles concerning mesenchymal stem cell (MSC)-derived exosomes for regeneration of bone, cartilage and skin defects.

METHOD

Scopus, PubMed, EMBASE, and Web of Science were searched for keywords "Exosome, MSC, Skin, Bone and Cartilage defects, Regenerative medicine, and extracellular vesicles.

RESULTS

MSC-derived exosomes can emulate the biological activity of MSCs by horizontal transfer of multiple functional molecules including mRNAs, miRNAs, proteins, and lipids to the local microenvironment and recipient cells, and subsequently mediate restoring homeostasis and tissue regeneration through various mechanisms. Compared to MSCs, MSC-derived exosomes reveal many advantages such as non-immunogenicity, easy access, easy preservation, and extreme stability under various conditions.

CONCLUSION

Hence, exosomes could be considered as an alternative strategy for cell-based therapies in regenerative medicine. In this paper, after describing the characteristics of exosomes, we will review the recent literature on the therapeutic potentials of MSC-derived exosomes in skin, bone, and cartilage repair.

Sequencing the Origins of Life

One goal of origins of life research is to understand how primitive informational and catalytic biopolymers emerged and evolved. Recently, a number of sequencing techniques have been applied to analysis of replicating and evolving primitive biopolymer systems, providing a sequence-specific and high-resolution view of primitive chemical processes. Here, we review application of sequencing techniques to analysis of synthetic and primitive nucleic acids and polypeptides. This includes next-generation sequencing of primitive polymerization and evolution processes, followed by discussion of other novel biochemical techniques that could contribute to sequence analysis of primitive biopolymer driven chemical systems. Further application of sequencing to origins of life research, perhaps as a life detection technology, could provide insight into the origin and evolution of informational and catalytic biopolymers on early Earth or elsewhere.

Perspectives on Bovine Milk-Derived Extracellular Vesicles for Therapeutic Applications in Gut Health

Extracellular vesicles (EVs) are nanosized vesicles secreted from cells into the extracellular environment and are composed of a lipid bilayer that contains cargos with biological activity, such as lipids, proteins, mRNAs, and noncoding microRNAs (miRNAs). Due to their biological activity and their role in cell-to-cell communication, interest in EVs is rapidly increasing. Bovine milk is a food consumed by people of all ages around the world that contains not only a significant amount of nutrients but also EVs. Milk-derived EVs also exhibit biological activity similar to other source-derived EVs, and studies on bovine milk EVs have been conducted in various research fields regarding sufficient milk production. In particular, not only are the effects of milk EVs themselves being studied, but the possibility of using them as drug carriers or biomarkers is also being studied. In this review, the characteristics and cargo of milk EVs are summarized, as well as their uptake and stability, efficacy and biological effects as carriers, and future research directions are presented.

Tumor-Derived Extracellular Vesicles Induce Abnormal Angiogenesis via TRPV4 Downregulation and Subsequent Activation of YAP and VEGFR2

Tumor angiogenesis is initiated and maintained by the tumor microenvironment through secretion of autocrine and paracrine factors, including extracellular vesicles (EVs). Although tumor-derived EVs (t-EVs) have been implicated in tumor angiogenesis, growth and metastasis, most studies on t-EVs are focused on proangiogenic miRNAs and growth factors. We have recently demonstrated that conditioned media from human lung tumor cells (A549) downregulate TRPV4 channels and transform normal endothelial cells to a tumor endothelial cell-like phenotype and induce abnormal angiogenesis in vitro, via t-EVs. However, the underlying molecular mechanism of t-EVs on endothelial cell phenotypic transition and abnormal angiogenesis in vivo remains unknown. Here, we demonstrate that t-EVs downregulate TRPV4 expression post-translationally and induce abnormal angiogenesis by activating Rho/Rho kinase/YAP/VEGFR2 pathways. Further, we demonstrate that t-EVs induce abnormal vessel formation in subcutaneously implanted Matrigel plugs in vivo (independent of tumors), which are characterized by increased VEGFR2 expression and reduced pericyte coverage. Taken together, our findings demonstrate that t-EVs induce abnormal angiogenesis via TRPV4 downregulation-mediated activation of Rho/Rho kinase/YAP/VEGFR2 pathways and suggest t-EVs and TRPV4 as novel targets for vascular normalization and cancer therapy.

The Aquatic Invertebrate Hydra vulgaris Releases Molecular Messages Through Extracellular Vesicles

Recent body of evidence demonstrates that extracellular vesicles (EVs) represent the first language of cell-cell communication emerged during evolution. In aquatic environments, transferring signals between cells by EVs offers protection against degradation, allowing delivering of chemical information in high local concentrations to the target cells. The packaging of multiple signals, including those of hydrophobic nature, ensures target cells to receive the same EV-conveyed messages, and the coordination of a variety of physiological processes across cells of a single organisms, or at the population level, i.e., mediating the population’s response to changing environmental conditions. Here, we purified EVs from the medium of the freshwater invertebrate Hydra vulgaris, and the molecular profiling by proteomic and transcriptomic analyses revealed multiple markers of the exosome EV subtype, from structural proteins to stress induced messages promoting cell survival. Moreover, positive and negative regulators of the Wnt/β-catenin signaling pathway, the major developmental pathway acting in body axial patterning, were identified. Functional analysis on amputated polyps revealed EV ability to modulate both head and foot regeneration, suggesting bioactivity of the EV cargo and opening new perspectives on the mechanisms of developmental signalling. Our results open the path to unravel EV biogenesis and function in all cnidarian species, tracing back the origin of the cell-cell, cross-species or cross-kingdom communication in aquatic ecosystems.

Linear and nonlinear optical properties of transfer ribonucleic acid (tRNA) thin solid films

We successfully obtained transfer ribonucleic acid (tRNA) thin solid films (TSFs) using an aqueous solution precursor in an optimized deposition process. By varying the concentration of RNA and deposition process parameters, uniform solid layers of solid RNA with a thickness of 30 to 46 nm were fabricated consistently. Linear absorptions of RNA TSFs on quartz substrates were experimentally investigated in a wide spectral range covering UV–VIS–NIR to find high transparency for λ > 350 nm. We analyzed the linear refractive indices, n(λ) of tRNA TSFs on silicon substrates by using an ellipsometer in the 400 to 900 nm spectral range to find a linear correlation with the tRNA concentration in the aqueous solution. The thermo-optic coefficient (dn/dT) of the films was also measured to be in a range −4.21 × 10⁻⁴ to −5.81 × 10⁻⁴ °C⁻¹ at 40 to 90 °C. We furthermore characterized nonlinear refractive index and nonlinear absorption of tRNA TSFs on quartz using a Z-scan method with a femtosecond laser at λ = 795 nm, which showed high potential as an efficient nonlinear optical material in the IR spectral range.

Optical measurements of one of the vital biological molecules (RNA) in the human body.

Roles of extracellular vesicles associated non-coding RNAs in Diabetes Mellitus

Extracellular vesicles (EVs), especially exosomes (50 to 150 nm), have been shown to play important roles in a wide range of physiological and pathological processes, including metabolic diseases such as Diabetes Mellitus (DM). In the last decade, several studies have demonstrated how EVs are involved in cell-to-cell communication. EVs are enriched in proteins, mRNAs and non-coding RNAs (miRNAs, long non-coding RNAs and circRNAS, among others) which are transferred to recipient cells and may have a profound impact in either their survival or functionality. Several studies have pointed out the contribution of exosomal miRNAs, such as miR-l42-3p and miR-26, in the development of Type 1 and Type 2 DM (T1DM and T2DM), respectively. In addition, some miRNA families such as miR-let7 and miR-29 found in exosomes have been associated with both types of diabetes, suggesting that they share common etiological features. The knowledge about the role of exosomal long non-coding RNAs in this group of diseases is more immature, but the exosomal lncRNA MALAT1 has been found to be elevated in the plasma of individuals with T2DM, while more than 169 lncRNAs were reported to be differentially expressed between healthy donors and people with T1DM. Here, we review the current knowledge about exosomal non-coding RNAs in DM and discuss their potential as novel biomarkers and possible therapeutic targets.

Biodistribution of unmodified cardiosphere-derived cell extracellular vesicles using single RNA tracing

Extracellular vesicles (EVs) are potent signalling mediators. Although interest in EV translation is ever-increasing, development efforts are hampered by the inability to reliably assess the uptake of EVs and their RNA cargo. Here, we establish a novel qPCR-based method for the detection of unmodified EVS using an RNA Tracer (DUST). In this proof-of-concept study we use a human-specific Y RNA-derived small RNA (YsRNA) we dub "NT4" that is enriched in cardiosphere-derived cell small EVs (CDC-sEVs). The assay is robust, sensitive, and reproducible. Intravenously administered CDC-sEVs accumulated primarily in the heart on a per mg basis. Cardiac injury enhanced EV uptake in the heart, liver, and brain. Inhibition of EV docking by heparin suppressed uptake variably, while inhibition of endocytosis attenuated uptake in all organs. In vitro, EVs were uptaken more efficiently by macrophages, endothelial cells, and cardiac fibroblasts compared to cardiomyocytes. These findings demonstrate the utility of DUST to assess uptake of EVs in vivo and in vitro.

Technological Approaches in the Analysis of Extracellular Vesicle Nucleotide Sequences

Together with metabolites, proteins, and lipid components, the EV cargo consists of DNA and RNA nucleotide sequence species, which are part of the intracellular communication network regulating specific cellular processes and provoking distinct target cell responses. The extracellular vesicle (EV) nucleotide sequence cargo molecules are often investigated in association with a particular pathology and may provide an insight into the physiological and pathological processes in hard-to-access organs and tissues. The diversity and biological function of EV nucleotide sequences are distinct regarding EV subgroups and differ in tissue- and cell-released EVs. EV DNA is present mainly in apoptotic bodies, while there are different species of EV RNAs in all subgroups of EVs. A limited sample volume of unique human liquid biopsy provides a small amount of EVs with limited isolated DNA and RNA, which can be a challenging factor for EV nucleotide sequence analysis, while the additional difficulty is technical variability of molecular nucleotide detection. Every EV study is challenged with its first step of the EV isolation procedure, which determines the EV's purity, yield, and diameter range and has an impact on the EV's downstream analysis with a significant impact on the final result. The gold standard EV isolation procedure with ultracentrifugation provides a low output and not highly pure isolated EVs, while modern techniques increase EV's yield and purity. Different EV DNA and RNA detection techniques include the PCR procedure for nucleotide sequence replication of the molecules of interest, which can undergo a small-input EV DNA or RNA material. The nucleotide sequence detection approaches with their advantages and disadvantages should be considered to appropriately address the study problem and to extract specific EV nucleotide sequence information with the detection using qPCR or next-generation sequencing. Advanced next-generation sequencing techniques allow the detection of total EV genomic or transcriptomic data even at the single-molecule resolution and thus, offering a sensitive and accurate EV DNA or RNA biomarker detection. Additionally, with the processes where the EV genomic or transcriptomic data profiles are compared to identify characteristic EV differences in specific conditions, novel biomarkers could be discovered. Therefore, a suitable differential expression analysis is crucial to define the EV DNA or RNA differences between conditions under investigation. Further bioinformatics analysis can predict molecular cell targets and identify targeted and affected cellular pathways. The prediction target tools with functional studies are essential to help specify the role of the investigated EV-targeted nucleotide sequences in health and disease and support further development of EV-related therapeutics. This review will discuss the biological diversity of human liquid biopsy-obtained EV nucleotide sequences DNA and RNA species reported as potential biomarkers in health and disease and methodological principles of their detection, from human liquid biopsy EV isolation, EV nucleotide sequence extraction, techniques for their detection, and their cell target prediction.

Characterization of ovarian cancer-derived extracellular vesicles by surface-enhanced Raman spectroscopy

Ovarian cancer is the most lethal gynecological malignancy, owing to the fact that most cases are diagnosed at a late stage. To improve prognosis and reduce mortality, we must develop methods for the early diagnosis of ovarian cancer. A step towards early and non-invasive cancer diagnosis is through the utilization of extracellular vesicles (EVs), which are nanoscale, membrane-bound vesicles that contain proteins and genetic material reflective of their parent cell. Thus, EVs secreted by cancer cells can be thought of as cancer biomarkers. In this paper, we present gold nanohole arrays for the capture of ovarian cancer (OvCa)-derived EVs and their characterization by surface-enhanced Raman spectroscopy (SERS). For the first time, we have characterized EVs isolated from two established OvCa cell lines (OV-90, OVCAR3), two primary OvCa cell lines (EOC6, EOC18), and one human immortalized ovarian surface epithelial cell line (hIOSE) by SERS. We subsequently determined their main compositional differences by principal component analysis and were able to discriminate the groups by a logistic regression-based machine learning method with ∼99% accuracy, sensitivity, and specificity. The results presented here are a great step towards quick, facile, and non-invasive cancer diagnosis.

Role of Extracellular Vesicle-Based Cell-to-Cell Communication in Multiple Myeloma Progression

Multiple myeloma (MM) progression closely depends on the bidirectional crosstalk between tumor cells and the surrounding microenvironment, which leads to the creation of a tumor supportive niche. Extracellular vesicles (EVs) have emerged as key players in the pathological interplay between the malignant clone and near/distal bone marrow (BM) cells through their biologically active cargo. Here, we describe the role of EVs derived from MM and BM cells in reprogramming the tumor microenvironment and in fostering bone disease, angiogenesis, immunosuppression, drug resistance, and, ultimately, tumor progression. We also examine the emerging role of EVs as new therapeutic agents for the treatment of MM, and their potential use as clinical biomarkers for early diagnosis, disease classification, and therapy monitoring.

Extracellular Vesicles and Their Relationship with the Heart-Kidney Axis, Uremia and Peritoneal Dialysis

Cardiorenal syndrome (CRS) is described as primary dysfunction in the heart culminating in renal injury or vice versa. CRS can be classified into five groups, and uremic toxin (UT) accumulation is observed in all types of CRS. Protein-bound uremic toxin (PBUT) accumulation is responsible for permanent damage to the renal tissue, and mainly occurs in CRS types 3 and 4, thus compromising renal function directly leading to a reduction in the glomerular filtration rate (GFR) and/or subsequent proteinuria. With this decrease in GFR, patients may need renal replacement therapy (RRT), such as peritoneal dialysis (PD). PD is a high-quality and home-based dialysis therapy for patients with end-stage renal disease (ESRD) and is based on the semi-permeable characteristics of the peritoneum. These patients are exposed to factors which may cause several modifications on the peritoneal membrane. The presence of UT may harm the peritoneum membrane, which in turn can lead to the formation of extracellular vesicles (EVs). EVs are released by almost all cell types and contain lipids, nucleic acids, metabolites, membrane proteins, and cytosolic components from their cell origin. Our research group previously demonstrated that the EVs can be related to endothelial dysfunction and are formed when UTs are in contact with the endothelial monolayer. In this scenario, this review explores the mechanisms of EV formation in CRS, uremia, the peritoneum, and as potential biomarkers in peritoneal dialysis.

Exercise mimetics: harnessing the therapeutic effects of physical activity

Exercise mimetics are a proposed class of therapeutics that specifically mimic or enhance the therapeutic effects of exercise. Increased physical activity has demonstrated positive effects in preventing and ameliorating a wide range of diseases, including brain disorders such as Alzheimer disease and dementia, cancer, diabetes and cardiovascular disease. This article discusses the molecular mechanisms and signalling pathways associated with the beneficial effects of physical activity, focusing on effects on brain function and cognitive enhancement. Emerging therapeutic targets and strategies for the development of exercise mimetics, particularly in the field of central nervous system disorders, as well as the associated opportunities and challenges, are discussed.

Lipids and Lipid Derivatives for RNA Delivery

RNA-based therapeutics have shown great promise in treating a broad spectrum of diseases through various mechanisms including knockdown of pathological genes, expression of therapeutic proteins, and programmed gene editing. Due to the inherent instability and negative-charges of RNA molecules, RNA-based therapeutics can make the most use of delivery systems to overcome biological barriers and to release the RNA payload into the cytosol. Among different types of delivery systems, lipid-based RNA delivery systems, particularly lipid nanoparticles (LNPs), have been extensively studied due to their unique properties, such as simple chemical synthesis of lipid components, scalable manufacturing processes of LNPs, and wide packaging capability. LNPs represent the most widely used delivery systems for RNA-based therapeutics, as evidenced by the clinical approvals of three LNP-RNA formulations, patisiran, BNT162b2, and mRNA-1273. This review covers recent advances of lipids, lipid derivatives, and lipid-derived macromolecules used in RNA delivery over the past several decades. We focus mainly on their chemical structures, synthetic routes, characterization, formulation methods, and structure-activity relationships. We also briefly describe the current status of representative preclinical studies and clinical trials and highlight future opportunities and challenges.

Designer Exosomes: Smart Nano-Communication Tools for Translational Medicine

Exosomes are the master transporters of genes, RNAs, microRNAs, proteins, and lipids. They have applications in major diseases, including cancer, cardiovascular diseases, neurological disorders, and diabetes mellitus. Delivery of the exosomes to recipient cells is governed by the functional heterogenicity of the tissues. Engineered exosomes are promising tools in tissue regeneration. In addition to their role as intracellular communication cargos, exosomes are increasingly primed as standard biomarkers in the progression of diseases, thereby solving the diagnostic dilemma. Futuristic empowerment of exosomes with OMICS strategy can undoubtedly be a bio-tool in translational medicine. This review discusses the advent transformation of exosomes in regenerative medicine and limitations that are caveats to broader applications in clinical use.

Gift bags from the sentinel cells of the immune system: The diverse role of dendritic cell-derived extracellular vesicles

Dendritic cells (DCs) are professional APCs of the immune system that continuously sample their environment and function to stimulate an adaptive immune response by initiating Ag-specific immunity or tolerance. Extracellular vesicles (EVs), small membrane-bound structures, are released from DCs and have been discovered to harbor functional peptide-MHC complexes, T cell costimulatory molecules, and other molecules essential for Ag presentation, immune cell regulation, and stimulating immune responses. As such, DC-derived EVs are being explored as potential immunotherapeutic agents. DC-derived EVs have also been implicated to function as a trafficking mechanism of infectious particles aiding viral propagation. This review will explore the unique features that enable DC-derived EVs to regulate immune responses and interact with recipient cells, their roles within Ag-presentation and disease settings, as well as speculating on a potential immunological role of apoptotic DC-derived EVs.

Low-bias ncRNA libraries using ordered two-template relay: Serial template jumping by a modified retroelement reverse transcriptase

Retrotransposons are noninfectious, mobile genetic elements that proliferate in host genomes via an RNA intermediate that is copied into DNA by a reverse transcriptase (RT) enzyme. RTs are important for biotechnological applications involving information capture from RNA since RNA is first converted into complementary DNA for detection or sequencing. Here, we biochemically characterized RTs from two retroelements and uncovered several activities that allowed us to design a streamlined, efficient workflow for determining the inventory of RNA sequences in processed RNA pools. The unique properties of nonretroviral RT activities obviate many technical issues associated with current methods of RNA sequence analysis, with wide applications in research, biotechnology, and diagnostics.

Selfish, non-long terminal repeat (non-LTR) retroelements and mobile group II introns encode reverse transcriptases (RTs) that can initiate DNA synthesis without substantial base pairing of primer and template. Biochemical characterization of these enzymes has been limited by recombinant expression challenges, hampering understanding of their properties and the possible exploitation of their properties for research and biotechnology. We investigated the activities of representative RTs using a modified non-LTR RT from Bombyx mori and a group II intron RT from Eubacterium rectale. Only the non-LTR RT supported robust and serial template jumping, producing one complementary DNA (cDNA) from several templates each copied end to end. We also discovered an unexpected terminal deoxynucleotidyl transferase activity of the RTs that adds nucleotide(s) of choice to 3′ ends of single- and/or double-stranded RNA or DNA. Combining these two types of activity with additional insights about nontemplated nucleotide additions to duplexed cDNA product, we developed a streamlined protocol for fusion of next-generation sequencing adaptors to both cDNA ends in a single RT reaction. When benchmarked using a reference pool of microRNAs (miRNAs), library production by Ordered Two-Template Relay (OTTR) using recombinant non-LTR retroelement RT outperformed all commercially available kits and rivaled the low bias of technically demanding home-brew protocols. We applied OTTR to inventory RNAs purified from extracellular vesicles, identifying miRNAs as well as myriad other noncoding RNAs (ncRNAs) and ncRNA fragments. Our results establish the utility of OTTR for automation-friendly, low-bias, end-to-end RNA sequence inventories of complex ncRNA samples.

Non-targeted effects of radiation: a personal perspective on the role of exosomes in an evolving paradigm

PURPOSE

Radiation-induced non-targeted effects (NTE) have implications in a variety of areas relevant to radiation biology. Here we evaluate the various cargo associated with exosomal signalling and how they work synergistically to initiate and propagate the non-targeted effects including Genomic Instability and Bystander Effects.

CONCLUSIONS

Extra cellular vesicles, in particular exosomes, have been shown to carry bystander signals. Exosome cargo may contain nucleic acids, both DNA and RNA, as well as proteins, lipids and metabolites. These cargo molecules have all been considered as potential mediators of NTE. A review of current literature shows mounting evidence of a role for ionizing radiation in modulating both the numbers of exosomes released from affected cells as well as the content of their cargo, and that these exosomes can instigate functional changes in recipient cells. However, there are significant gaps in our understanding, particularly regarding modified exosome cargo after radiation exposure and the functional changes induced in recipient cells.

Therapeutic perspectives of extracellular vesicles and extracellular microRNAs in atherosclerosis

Extracellular signaling molecules, such as growth factors, cytokines, and hormones, regulate cell behaviors and fate through endocrine, paracrine, and autocrine actions and play essential roles in maintaining tissue homeostasis. MicroRNAs, an important class of posttranscriptional modulators, could stably present in extracellular space and body fluids and participate in intercellular communication in health and diseases. Indeed, recent studies demonstrated that microRNAs could be secreted through vesicular and non-vesicular routes, transported in body fluids, and then transmitted to recipient cells to regulate target gene expression and signaling events. Over the past decade, a great deal of effort has been made to investigate the functional roles of extracellular vesicles and extracellular microRNAs in pathological conditions. Emerging evidence suggests that altered levels of extracellular vesicles and extracellular microRNAs in body fluids, as part of the cellular responses to atherogenic factors, are associated with the development of atherosclerosis. This review article provides a brief overview of extracellular vesicles and perspectives of their applications as therapeutic tools for cardiovascular pathologies. In addition, we highlight the role of extracellular microRNAs in atherogenesis and offer a summary of circulating microRNAs in liquid biopsies associated with atherosclerosis.

Visualizing transfer of microbial biomolecules by outer membrane vesicles in microbe-host-communication in vivo

The intestinal microbiota influences mammalian host physiology in health and disease locally in the gut but also in organs devoid of direct contact with bacteria such as the liver and brain. Extracellular vesicles (EVs) or outer membrane vesicles (OMVs) released by microbes are increasingly recognized for their potential role as biological shuttle systems for inter-kingdom communication. However, physiologically relevant evidence for the transfer of functional biomolecules from the intestinal microbiota to individual host cells by OMVs in vivo is scarce. By introducing Escherichia coli engineered to express Cre-recombinase (E. coliCre ) into mice with a Rosa26.tdTomato-reporter background, we leveraged the Cre-LoxP system to report the transfer of bacterial OMVs to recipient cells in vivo. Colonizing the intestine of these mice with E. coliCre , resulted in Cre-recombinase induced fluorescent reporter gene-expression in cells along the intestinal epithelium, including intestinal stem cells as well as mucosal immune cells such as macrophages. Furthermore, even far beyond the gut, bacterial-derived Cre induced extended marker gene expression in a wide range of host tissues, including the heart, liver, kidney, spleen, and brain. Together, our findings provide a method and proof of principle that OMVs can serve as a biological shuttle system for the horizontal transfer of functional biomolecules between bacteria and mammalian host cells.

Extracellular Vesicle Nanoarchitectonics for Novel Drug Delivery Applications

Extracellular vesicles (EVs) can transfer intercellular messages in various (patho)physiological processes and transport biomolecules to recipient cells. EVs possess the capacity to evade the immune system and remain stable over long periods, identifying them as natural carriers for drugs and biologics. However, the challenges associated with EVs isolation, heterogeneity, coexistence with homologous biomolecules, and lack of site-specific delivery, have impeded their potential. In recent years, the amalgamation of EVs with rationally engineered nanostructures has been proposed for achieving effective drug loading and site-specific delivery. With the advancement of nanotechnology and nanoarchitectonics, different nanostructures with tunable size, shapes, and surface properties can be integrated with EVs for drug loading, target binding, efficient delivery, and therapeutics. Such integration may enable improved cellular targeting and the protection of encapsulated drugs for enhanced and specific delivery to target cells. This review summarizes the recent development of nanostructure amalgamated EVs for drug delivery, therapeutics, and real-time monitoring of disease progression. With a specific focus on the exosomal cargo, diverse drug delivery system, and biomimetic nanostructures based on EVs for selective drug delivery, this review also chronicles the needs and challenges of EV-based biomimetic nanostructures and provides a future outlook on the strategies posed.

Delivery of Oligonucleotide Therapeutics: Chemical Modifications, Lipid Nanoparticles, and Extracellular Vesicles

Oligonucleotides (ONs) comprise a rapidly growing class of therapeutics. In recent years, the list of FDA-approved ON therapies has rapidly expanded. ONs are small (15-30 bp) nucleotide-based therapeutics which are capable of targeting DNA and RNA as well as other biomolecules. ONs can be subdivided into several classes based on their chemical modifications and on the mechanisms of their target interactions. Historically, the largest hindrance to the widespread usage of ON therapeutics has been their inability to effectively internalize into cells and escape from endosomes to reach their molecular targets in the cytosol or nucleus. While cell uptake has been improved, "endosomal escape" remains a significant problem. There are a range of approaches to overcome this, and in this review, we focus on three: altering the chemical structure of the ONs, formulating synthetic, lipid-based nanoparticles to encapsulate the ONs, or biologically loading the ONs into extracellular vesicles. This review provides a background to the design and mode of action of existing FDA-approved ONs. It presents the most common ON classifications and chemical modifications from a fundamental scientific perspective and provides a roadmap of the cellular uptake pathways by which ONs are trafficked. Finally, this review delves into each of the above-mentioned approaches to ON delivery, highlighting the scientific principles behind each and covering recent advances.

Translational Potential of RNA Derived From Extracellular Vesicles in Multiple Myeloma

The cross-talk between tumour cells and stromal cells is a hallmark of multiple myeloma (MM), a blood cancer that still remains incurable despite increased knowledge of its biology and advances in its treatment. Extracellular vesicles (EVs) derived from both tumour and stromal cells have been shown to play an important role in mediating this cross-talk ultimately favouring MM progression and drug resistance. Furthermore, EVs and their content including RNA (EV-RNA) have been successfully isolated from blood and are being explored as liquid biomarkers in MM with the potential to improve diagnosis and monitoring modalities with a minimally-invasive and repeatable analysis, i.e. liquid biopsy. In this review, we describe both the role of EV-RNA in defining the biological features of MM and their potential translational relevance as liquid biomarkers, therapeutic targets and delivery systems. We also discuss the limitations and technical challenges related to the isolation and characterization of EVs and provide a perspective on the future of MM-derived EV-RNA in translational research.

Exosomes as mediators of intercellular crosstalk in metabolism

Exosomes are nanoparticles secreted by all cell types and are a large component of the broader class of nanoparticles termed extracellular vesicles (EVs). Once secreted, exosomes gain access to the interstitial space and ultimately the circulation, where they exert local paracrine or distal systemic effects. Because of this, exosomes are important components of an intercellular and intraorgan communication system capable of carrying biologic signals from one cell type or tissue to another. The exosomal cargo consists of proteins, lipids, miRNAs, and other RNA species, and many of the biologic effects of exosomes have been attributed to miRNAs. Exosomal miRNAs have also been used as disease biomarkers. The field of exosome biology and metabolism is rapidly expanding, with new discoveries and reports appearing on a regular basis, and it is possible that potential therapeutic approaches for the use of exosomes or miRNAs in metabolic diseases will be initiated in the near future.

Sampling, Logistics, and Analytics of Urine for RT-qPCR-based Diagnostics

Body fluids in the context of cancer diagnosis are the primary source of liquid biopsy, i.e., biomarker detection that includes blood and serum, urine, and saliva. RNA represents a particular class of biomarkers because it is thought to monitor the current status of gene expression in humans, in organs, and if present, also in tumors. In case of bladder cancer, we developed a scheme that describes, in detail, all steps from the collection of urine samples from patients, stabilization of samples, their transportation, storage, and marker analysis by qPCR-based technology. We find that urine samples prepared according to this protocol show stability of RNA over more than 10 days at unchilled temperatures during shipping. A specific procedure of primer design and amplicon evaluation allows a specific assignment of PCR products to human genomics and transcriptomics data collections. In summary, we describe a technical option for the robust acquisition of urine samples and the quantitative detection of RNA-based tumor markers in case of bladder cancer patients. This protocol is for general use, and we describe that it works for any RNA-based tumor marker in urine of cancer patients.

Label-Free Quantitative Phase Imaging Reveals Spatial Heterogeneity of Extracellular Vesicles in Select Colon Disorders

Three-dimensional (3D) imaging and quantitative analysis of extracellular vesicles (EVs) remain largely unexplored, mainly because of limitations in detection techniques. In this study, EVs from patients diagnosed with colorectal cancer (CRC) and ulcerative colitis were examined. To investigate the spatial heterogeneity and 3D refractive index (RI) distribution of single EVs, a label-free digital holographic tomography technique was used at a submicrometer spatial resolution. The presented image-processing algorithms were used in quantitative analysis with digital staining and 3D visualization, the determination of the EV size distribution and extraction of fractions with different RIs. Reconstructed 3D RI distributions revealed variations in the spatial heterogeneity of EVs related to tissue specificity, such as CRC, normal colonic mucosa, and ulcerative colitis, as well as the isolation procedures used. The RI values of EVs isolated from solid tissues of frozen CRC samples were also dependent on the tumor grade and cancer cell proliferation. The simultaneous examination of cell culture models confirmed the association of the RI of EVs with the tumor grade. 3D-RI data analysis generates new perspectives with the optical, contact-free, label-free examination of the individual EVs. Depending on the specific tissue and isolation method, EVs exhibit significant spatial heterogeneity. The optical parameters of single EVs enabled their classification into two unique subgroups with different RI values.

Genetics and Inflammation in Endometriosis: Improving Knowledge for Development of New Pharmacological Strategies

According to a rich body of literature, immune cell dysfunctions, both locally and systemically, and an inflammatory environment characterize all forms of endometriosis. Alterations in transcripts and proteins involved in the recruitment of immune cells, in the interaction between cytokines and their receptors, cellular adhesion and apoptosis have been demonstrated in endometriotic lesions. The objective of this narrative review is to provide an overview of the components and mechanisms at the intersection between inflammation and genetics that may constitute vanguard therapeutic approaches in endometriosis. The GWAS technology and pathway-based analysis highlighted the role of the MAPK and the WNT/β-catenin cascades in the pathogenesis of endometriosis. These signaling pathways have been suggested to interfere with the disease establishment via several mechanisms, including apoptosis, migration and angiogenesis. Extracellular vesicle-associated molecules may be not only interesting to explain some aspects of endometriosis progression, but they may also serve as therapeutic regimens per se. Immune/inflammatory dysfunctions have always represented attractive therapeutic targets in endometriosis. These would be even more interesting if genetic evidence supported the involvement of functional pathways at the basis of these alterations. Targeting these dysfunctions through next-generation inhibitors can constitute a therapeutic alternative for endometriosis.

Biomimetic Nanostructure Platform for Cancer Diagnosis Based on Tumor Biomarkers

Biomarker discovery and its clinical use have attracted considerable attention since early cancer diagnosis can significantly decrease mortality. Cancer biomarkers include a wide range of biomolecules, such as nucleic acids, proteins, metabolites, sugars, and cytogenetic substances present in human biofluids. Except for free-circulating biomarkers, tumor-extracellular vesicles (tEVs) and circulating tumor cells (CTCs) can serve as biomarkers for the diagnosis and prognosis of various cancers. Considering the potential of tumor biomarkers in clinical settings, several bioinspired detection systems based on nanotechnologies are in the spotlight for detection. However, tremendous challenges remain in detection because of massive contamination, unstable signal-to-noise ratios due to heterogeneity, nonspecific bindings, or a lack of efficient amplification. To date, many approaches are under development to improve the sensitivity and specificity of tumor biomarker isolation and detection. Particularly, the exploration of natural materials in biological frames has encouraged researchers to develop new bioinspired and biomimetic nanostructures, which can mimic the natural processes to facilitate biomarker capture and detection in clinical settings. These platforms have substantial influence in biomedical applications, owing to their capture ability, significant contrast increase, high sensitivity, and specificity. In this review, we first describe the potential of tumor biomarkers in a liquid biopsy and then provide an overview of the progress of biomimetic nanostructure platforms to isolate and detect tumor biomarkers, including in vitro and in vivo studies. Capture efficiency, scale, amplification, sensitivity, and specificity are the criteria that will be further discussed for evaluating the capability of platforms. Bioinspired and biomimetic systems appear to have a bright future to settle obstacles encountered in tumor biomarker detection, thus enhancing effective cancer diagnosis.

Cerebrospinal Fluid of Patients With Alzheimer's Disease Contains Increased Percentages of Synaptophysin-Bearing Microvesicles

Introduction

In Alzheimer’s disease, the severity of symptoms is linked to a loss of synaptic density and the spread of pathologically hyperphosphorylated tau. The established cerebrospinal fluid markers Aβ, tau and phospho-tau reflect the histopathological hallmarks of Alzheimer’s disease but do not indicate disease progression. Such markers are of special interest, especially for trials of disease modifying drugs. Microvesicles are produced by stressed cells and reflect part of the metabolism of their cells of origin. Therefore, we investigated microvesicles of neuronal origin in cerebrospinal fluid.

Materials and Methods

We used flow cytometry to analyze microvesicles carrying tau, phospho-tau-Thr181, phospho-tau-Ser202Thr205, synaptophysin, and SNAP-25 in the cerebrospinal fluid of 19 patients with Alzheimer’s disease and 15 non-inflammatory neurological disease controls.

Results

The percentages of synaptophysin-bearing microvesicles were significantly higher in the cerebrospinal fluid of patients with Alzheimer’s disease than in the CSF of non-inflammatory neurological disease controls. Tau, phospho-tau-Thr181, phospho-tau-Ser202Thr205, and SNAP-25 did not differ between the groups. The percentages of synaptophysin-bearing vesicles distinguished patients with Alzheimer’s disease from the controls (AUC = 0.81).

Conclusion

The loss of synapses in Alzheimer’s disease may be reflected by synaptophysin-bearing microvesicles in the cerebrospinal fluid. Future studies are needed to investigate the possibility of using these MVs as a marker to determine the activity of Alzheimer’s disease.

The Role of Long Non-Coding RNAs in Trophoblast Regulation in Preeclampsia and Intrauterine Growth Restriction

Preeclampsia (PE) and Intrauterine Growth Restriction (IUGR) are two pregnancy-specific placental disorders with high maternal, fetal, and neonatal morbidity and mortality rates worldwide. The identification biomarkers involved in the dysregulation of PE and IUGR are fundamental for developing new strategies for early detection and management of these pregnancy pathologies. Several studies have demonstrated the importance of long non-coding RNAs (lncRNAs) as essential regulators of many biological processes in cells and tissues, and the placenta is not an exception. In this review, we summarize the importance of lncRNAs in the regulation of trophoblasts during the development of PE and IUGR, and other placental disorders.

Hepatitis Delta Virus (HDV) and Delta-Like Agents: Insights Into Their Origin

Hepatitis delta virus (HDV) is a human pathogen, and the only known species in the genus Deltavirus. HDV is a satellite virus and depends on the hepatitis B virus (HBV) for packaging, release, and transmission. Extracellular HDV virions contain the genomic HDV RNA, a single-stranded negative-sense and covalently closed circular RNA molecule, which is associated with the HDV-encoded delta antigen forming a ribonucleoprotein complex, and enveloped by the HBV surface antigens. Replication occurs in the nucleus and is mediated by host enzymes and assisted by cis-acting ribozymes allowing the formation of monomer length molecules which are ligated by host ligases to form unbranched rod-like circles. Recently, meta-transcriptomic studies investigating various vertebrate and invertebrate samples identified RNA species with similarities to HDV RNA. The delta-like agents may be representatives of novel subviral agents or satellite viruses which share with HDV, the self-complementarity of the circular RNA genome, the ability to encode a protein, and the presence of ribozyme sequences. The widespread distribution of delta-like agents across different taxa with considerable phylogenetic distances may be instrumental in comprehending their evolutionary history by elucidating the transition from transcriptome to cellular circular RNAs to infectious subviral agents.

Characterization of extracellular vesicles derived from mesenchymal stromal cells by surface-enhanced Raman spectroscopy

Extracellular vesicles (EVs) are secreted by all cells into bodily fluids and play an important role in intercellular communication through the transfer of proteins and RNA. There is evidence that EVs specifically released from mesenchymal stromal cells (MSCs) are potent cell-free regenerative agents. However, for MSC EVs to be used in therapeutic practices, there must be a standardized and reproducible method for their characterization. The detection and characterization of EVs are a challenge due to their nanoscale size as well as their molecular heterogeneity. To address this challenge, we have fabricated gold nanohole arrays of varying sizes and shapes by electron beam lithography. These platforms have the dual purpose of trapping single EVs and enhancing their vibrational signature in surface-enhanced Raman spectroscopy (SERS). In this paper, we report SERS spectra for MSC EVs derived from pancreatic tissue (Panc-MSC) and bone marrow (BM-MSC). Using principal component analysis (PCA), we determined that the main compositional differences between these two groups are found at 1236, 761, and 1528 cm^-1, corresponding to amide III, tryptophan, and an in-plane -C=C- vibration, respectively. We additionally explored several machine learning approaches to distinguish between BM- and Panc-MSC EVs and achieved 89 % accuracy, 89 % sensitivity, and 88 % specificity using logistic regression.

Nucleic acid delivery with extracellular vesicles

Extracellular vesicles (EVs) are membrane-enclosed particles, heterogeneous in size, shape, contents, biogenesis and structure. They are released by eukaryotic and prokaryotic cells and exert (patho-)physiological roles as mediators for transmitting molecular information from the producer (donor) to a recipient cell. This review focuses on the potential of EVs for delivering nucleic acids, as particularly problematic cargoes with regard to stability/protection and uptake efficacy. It highlights important properties of EVs for nucleic acid delivery and discusses their physiological and pathophysiological roles with regard to various cellular RNA species. It then describes the application of EVs for delivering a broad selection of nucleic acids/oligonucleotides, in particular giving a comprehensive overview of preclinical in vivo studies and the various strategies explored. In this context, different techniques for EV loading are discussed, as well as other important technical aspects related to EV preparation, characterization and in particular, the various approaches of artificial EV modification.

Urinary extracellular vesicles: A position paper by the Urine Task Force of the International Society for Extracellular Vesicles

Urine is commonly used for clinical diagnosis and biomedical research. The discovery of extracellular vesicles (EV) in urine opened a new fast-growing scientific field. In the last decade urinary extracellular vesicles (uEVs) were shown to mirror molecular processes as well as physiological and pathological conditions in kidney, urothelial and prostate tissue. Therefore, several methods to isolate and characterize uEVs have been developed. However, methodological aspects of EV separation and analysis, including normalization of results, need further optimization and standardization to foster scientific advances in uEV research and a subsequent successful translation into clinical practice. This position paper is written by the Urine Task Force of the Rigor and Standardization Subcommittee of ISEV consisting of nephrologists, urologists, cardiologists and biologists with active experience in uEV research. Our aim is to present the state of the art and identify challenges and gaps in current uEV-based analyses for clinical applications. Finally, recommendations for improved rigor, reproducibility and interoperability in uEV research are provided in order to facilitate advances in the field.

Extracellular Vesicle Associated Non-Coding RNAs in Lung Infections and Injury

Extracellular vesicles (EVs) refer to a heterogenous population of membrane-bound vesicles that are released by cells under physiological and pathological conditions. The detection of EVs in the majority of the bodily fluids, coupled with their diverse cargo comprising of DNA, RNA, lipids, and proteins, have led to the accumulated interests in leveraging these nanoparticles for diagnostic and therapeutic purposes. In particular, emerging studies have identified enhanced levels of a wide range of specific subclasses of non-coding RNAs (ncRNAs) in EVs, thereby suggesting the existence of highly selective and regulated molecular processes governing the sorting of these RNAs into EVs. Recent studies have also illustrated the functional relevance of these enriched ncRNAs in a variety of human diseases. This review summarizes the current state of knowledge on EV-ncRNAs, as well as their functions and significance in lung infection and injury. As a majority of the studies on EV-ncRNAs in lung diseases have focused on EV-microRNAs, we will particularly highlight the relevance of these molecules in the pathophysiology of these conditions, as well as their potential as novel biomarkers therein. We also outline the current challenges in the EV field amidst the tremendous efforts to propel the clinical utility of EVs for human diseases. The lack of published literature on the functional roles of other EV-ncRNA subtypes may in turn provide new avenues for future research to exploit their feasibility as novel diagnostic and therapeutic targets in human diseases.

The Mystery of Red Blood Cells Extracellular Vesicles in Sleep Apnea with Metabolic Dysfunction

Sleep is very important for overall health and quality of life, while sleep disorder has been associated with several human diseases, namely cardiovascular, metabolic, cognitive, and cancer-related alterations. Obstructive sleep apnea (OSA) is the most common respiratory sleep-disordered breathing, which is caused by the recurrent collapse of the upper airway during sleep. OSA has emerged as a major public health problem and increasing evidence suggests that untreated OSA can lead to the development of various diseases including neurodegenerative diseases. In addition, OSA may lead to decreased blood oxygenation and fragmentation of the sleep cycle. The formation of free radicals or reactive oxygen species (ROS) can emerge and react with nitric oxide (NO) to produce peroxynitrite, thereby diminishing the bioavailability of NO. Hypoxia, the hallmark of OSA, refers to a decline of tissue oxygen saturation and affects several types of cells, playing cell-to-cell communication a vital role in the outcome of this interplay. Red blood cells (RBCs) are considered transporters of oxygen and nutrients to the tissues, and these RBCs are important interorgan communication systems with additional functions, including participation in the control of systemic NO metabolism, redox regulation, blood rheology, and viscosity. RBCs have been shown to induce endothelial dysfunction and increase cardiac injury. The mechanistic links between changes of RBC functional properties and cardiovascular are largely unknown. Extracellular vesicles (EVs) are secreted by most cell types and released in biological fluids both under physiological and pathological conditions. EVs are involved in intercellular communication by transferring complex cargoes including proteins, lipids, and nucleic acids from donor cells to recipient cells. Advancing our knowledge about mechanisms of RBC-EVs formation and their pathophysiological relevance may help to shed light on circulating EVs and to translate their application to clinical practice. We will focus on the potential use of RBC-EVs as valuable diagnostic and prognostic biomarkers and state-specific cargoes, and possibilities as therapeutic vehicles for drug and gene delivery. The use of RBC-EVs as a precision medicine for the diagnosis and treatment of the patient with sleep disorder will improve the prognosis and the quality of life in patients with cardiovascular disease (CVD).

Role of Microbiota-Derived Extracellular Vesicles in Gut-Brain Communication

Human intestinal microbiota comprise of a dynamic population of bacterial species and other microorganisms with the capacity to interact with the rest of the organism and strongly influence the host during homeostasis and disease. Commensal and pathogenic bacteria coexist in homeostasis with the intestinal epithelium and the gastrointestinal tract’s immune system, or GALT (gut-associated lymphoid tissue), of the host. However, a disruption to this homeostasis or dysbiosis by different factors (e.g., stress, diet, use of antibiotics, age, inflammatory processes) can cause brain dysfunction given the communication between the gut and brain. Recently, extracellular vesicles (EVs) derived from bacteria have emerged as possible carriers in gut-brain communication through the interaction of their vesicle components with immune receptors, which lead to neuroinflammatory immune response activation. This review discusses the critical role of bacterial EVs from the gut in the neuropathology of brain dysfunctions by modulating the immune response. These vesicles, which contain harmful bacterial EV contents such as lipopolysaccharide (LPS), peptidoglycans, toxins and nucleic acids, are capable of crossing tissue barriers including the blood-brain barrier and interacting with the immune receptors of glial cells (e.g., Toll-like receptors) to lead to the production of cytokines and inflammatory mediators, which can cause brain impairment and behavioral dysfunctions.

Intriguing Biomedical Applications of Synthetic and Natural Cell-Derived Vesicles: A Comparative Overview

The significant role of a vesicle is well recognized; however, only lately has the advancement in biomedical applications started to uncover their usefulness. Although the concept of vesicles originates from cell biology, it later transferred to chemistry and material science to develop nanoscale artificial vesicles for biomedical applications. Herein, we examine different synthetic and biological vesicles and their applications in the biomedical field in general. As our understanding of biological vesicles increases, more suitable biomimicking synthetic vesicles will be developed. The comparative discussion between synthetic and natural vesicles for biomedical applications is a relevant topic, and we envision this could enable the development of a proper approach to realize the next-generation treatment goals.

Extracellular vesicles piwi-interacting RNAs from skin mucus for identification of infected Cynoglossus semilaevis with Vibrio harveyi

Extracellular vesicles play a regulatory role in intracellular and intercellular transmission through a variety of biological information molecules, including mRNA, small RNAs and proteins. piRNAs are one kind of regulatory small RNAs in the vesicles at the post transcriptional level. Hereby, we isolated the extracellular vesicles from skin mucus and screened the piRNA profiles of these vesicles, aiming at developing biomarkers related to bacterial infections in Cynoglossus semilaevis. The different profilings of piRNAs in mucous extracellular vesicles of C. semilaevis were compared through small RNA sequencing, between fish infected with Vibrio harveyi and healthy ones. The number of clean reads on the alignment of exosome sick (ES) group was 105, 345 and that of exosome control (EC) group was 455, 144. GO and KEGG pathway enrichment analysis showed that most of the target genes were involved in cellular process, response to stimulus, biological regulation, immune system process and signal transduction, signal molecular and interaction, transport and catabolism. The 45 final candidate piRNAs related to immunity or infectious diseases included 20 piRNAs with high expression in the ES group and 25 piRNAs with a low expression in the ES group. After verification by qRT-PCR, there was significant difference of five piRNAs expression level between infected fish and healthy fish, in line with the sequencing. The expression level of piR-mmu-16401212, piR-mmu-26829319 and piR-gga-244092 in infected fish were significantly lower than that of control group, while piR-gga-71717 and piR-gga-99034 were higher, which implying that these piRNAs in mucous extracellular vesicles can be used to identify diseased fish from normal ones. This work supplied a novel class of biomarker for infection diagnosis in fish, and it will be benefit for screening disease resistant breeding of C. semilaevis.

Mesenchymal Stem Cell Derived Extracellular Vesicles for Repairing the Neurovascular Unit after Ischemic Stroke

Ischemic stroke is a debilitating disease and one of the leading causes of long-term disability. During the early phase after ischemic stroke, the blood-brain barrier (BBB) exhibits increased permeability and disruption, leading to an influx of immune cells and inflammatory molecules that exacerbate the damage to the brain tissue. Mesenchymal stem cells have been investigated as a promising therapy to improve the recovery after ischemic stroke. The therapeutic effects imparted by MSCs are mostly paracrine. Recently, the role of extracellular vesicles released by these MSCs have been studied as possible carriers of information to the brain. This review focuses on the potential of MSC derived EVs to repair the components of the neurovascular unit (NVU) controlling the BBB, in order to promote overall recovery from stroke. Here, we review the techniques for increasing the effectiveness of MSC-based therapeutics, such as improved homing capabilities, bioengineering protein expression, modified culture conditions, and customizing the contents of EVs. Combining multiple techniques targeting NVU repair may provide the basis for improved future stroke treatment paradigms.

Exosomes and extracellular vesicles: Rethinking the essential values in cancer biology

Extracellular vesicles (EVs) such as exosomes are released by all living cells and contain diverse bioactive molecules, including nucleic acids, proteins, lipids, and metabolites. Accumulating evidence of EV-related functions has revealed that these tiny vesicles can mediate specific cell-to-cell communication. Within the tumor microenvironment, diverse cells are actively interacting with their surroundings via EVs facilitating tumor malignancy by regulating malignant cascades including angiogenesis, immune modulation, and metastasis. This review summarizes the recent studies of fundamental understandings of EVs from the aspect of EV heterogeneity and highlights the role of EVs in the various steps from oncogenic to metastatic processes. The recognition of EV subtypes is necessary to identify which pathways can be affected by EVs and which subtypes can be targeted in therapeutic approaches or liquid biopsies.

Potential Mechanisms Linking Food-Derived MicroRNAs, Gut Microbiota and Intestinal Barrier Functions in the Context of Nutrition and Human Health

MicroRNAs (miRNAs) are non-coding single-stranded RNA molecules from 18 to 24 nucleotides that are produced by prokaryote and eukaryote organisms, which play a crucial role in regulating gene expression through binding to their mRNA targets. MiRNAs have acquired special attention for their potential in cross kingdom communication, notably food-derived microRNAs (xenomiRs), which could have an impact on microorganism and mammal physiology. In this review, we mainly aim to deal with new perspectives on: (1) The mechanism by which food-derived xenomiRs (mainly dietary plant xenomiRs) could be incorporated into humans through diet, in a free form, associated with proteins or encapsulated in exosome-like nanoparticles. (2) The impact of dietary plant-derived miRNAs in modulating gut microbiota composition, which in turn, could regulate intestinal barrier permeability and therefore, affect dietary metabolite, postbiotics or food-derived miRNAs uptake efficiency. Individual gut microbiota signature/composition could be also involved in xenomiR uptake efficiency through several mechanisms such us increasing the bioavailability of exosome-like nanoparticles miRNAs. (3) Gut microbiota dysbiosis has been proposed to contribute to disease development by affecting gut epithelial barrier permeability. For his reason, the availability and uptake of dietary plant xenomiRs might depend, among other factors, on this microbiota-related permeability of the intestine. We hypothesize and critically review that xenomiRs-microbiota interaction, which has been scarcely explored yet, could contribute to explain, at least in part, the current disparity of evidences found dealing with dietary miRNA uptake and function in humans. Furthermore, dietary plant xenomiRs could be involved in the establishment of the multiple gut microenvironments, in which microorganism would adapt in order to optimize the resources and thrive in them. Additionally, a particular xenomiR could preferentially accumulate in a specific region of the gastrointestinal tract and participate in the selection and functions of specific gut microbial communities.

MicroRNA regulation of vascular smooth muscle cells and its significance in cardiovascular diseases

Cardiovascular disease (CVD) is among the leading causes of death worldwide. MicroRNAs (miRNAs), regulatory molecules that repress protein expression, have attracted considerable attention in CVD research. The vasculature plays a big role in CVD development and progression and dysregulation of vascular cells underlies the root of many vascular diseases. This review provides a brief introduction of the biogenesis of miRNAs and exosomes, followed by overview of the regulatory mechanisms of miRNAs in vascular smooth muscle cells (VSMCs) intracellular signaling during phenotypic switching, senescence, calcification, and neointimal hyperplasia. Evidence of extracellular signaling of VSMCs and other cells via exosomal and circulating miRNAs is also presented. Lastly, current drawbacks and limitations of miRNA studies in CVD research and potential ways to overcome these disadvantages are discussed in detail. In-depth understanding of VSMC regulation via miRNAs will add substantial knowledge and advance research in diagnosis, disease progression, and (or) miRNA-derived therapeutic approaches in CVD research.

Longitudinal saliva omics responses to immune perturbation: a case study

Saliva omics has immense potential for non-invasive diagnostics, including monitoring very young or elderly populations, or individuals in remote locations. In this study, multiple saliva omics from an individual were monitored over three periods (100 timepoints) involving: (1) hourly sampling over 24 h without intervention, (2) hourly sampling over 24 h including immune system activation using the standard 23-valent pneumococcal polysaccharide vaccine, (3) daily sampling for 33 days profiling the post-vaccination response. At each timepoint total saliva transcriptome and proteome, and small RNA from salivary extracellular vesicles were profiled, including mRNA, miRNA, piRNA and bacterial RNA. The two 24-h periods were used in a paired analysis to remove daily variation and reveal vaccination responses. Over 18,000 omics longitudinal series had statistically significant temporal trends compared to a healthy baseline. Various immune response and regulation pathways were activated following vaccination, including interferon and cytokine signaling, and MHC antigen presentation. Immune response timeframes were concordant with innate and adaptive immunity development, and coincided with vaccination and reported fever. Overall, mRNA results appeared more specific and sensitive (timewise) to vaccination compared to other omics. The results suggest saliva omics can be consistently assessed for non-invasive personalized monitoring and immune response diagnostics.

Analysis of urinary exosomes applications for rare kidney disorders

Introduction: Exosomes are nanovesicles that play important functions in a variety of physiological and pathological conditions. They are powerful cell-to-cell communication tool thanks to the protein, mRNA, miRNA, and lipid cargoes they carry. They are also emerging as valuable diagnostic and prognostic biomarker sources. Urinary exosomes carry information from all the cells of the urinary tract, downstream of the podocyte. Rare kidney diseases are a subset of an inherited diseases whose genetic diagnosis can be unclear, and presentation can vary due to genetic, epigenetic, and environmental factors. Areas covered: In this review, we focus on a group of rare and often neglected kidney diseases, for which we have sufficient available literature data on urinary exosomes. The analysis of their content can help to comprehend pathological mechanisms and to identify biomarkers for diagnosis, prognosis, and therapeutic targets. Expert opinion: The foreseeable large-scale application of system biology approach to the profiling of exosomal proteins as a source of renal disease biomarkers will be also useful to stratify patients with rare kidney diseases whose penetrance, phenotypic presentation, and age of onset vary sensibly. This can ameliorate the clinical management.

A Review of Placenta and Umbilical Cord-Derived Stem Cells and the Immunomodulatory Basis of Their Therapeutic Potential in Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) is a devastating lung disorder of preterm infants as a result of an aberrant reparative response following exposures to various antenatal and postnatal insults. Despite sophisticated medical treatment in this modern era, the incidence of BPD remains unabated. The current strategies to prevent and treat BPD have met with limited success. The emergence of stem cell therapy may be a potential breakthrough in mitigating this complex chronic lung disorder. Over the last two decades, the human placenta and umbilical cord have gained increasing attention as a highly potential source of stem cells. Placenta-derived stem cells (PDSCs) and umbilical cord-derived stem cells (UCDSCs) display several advantages such as immune tolerance and are generally devoid of ethical constraints, in addition to their stemness qualities. They possess the characteristics of both embryonic and mesenchymal stromal/stem cells. Recently, there are many preclinical studies investigating the use of these cells as therapeutic agents in neonatal disease models for clinical applications. In this review, we describe the preclinical and clinical studies using PDSCs and UCDSCs as treatment in animal models of BPD. The source of these stem cells, routes of administration, and effects on immunomodulation, inflammation and regeneration in the injured lung are also discussed. Lastly, a brief description summarized the completed and ongoing clinical trials using PDSCs and UCDSCs as therapeutic agents in preventing or treating BPD. Due to the complexity of BPD, the development of a safe and efficient therapeutic agent remains a major challenge to both clinicians and researchers.

Immunomodulatory properties of extracellular vesicles in the dialogue between placental and immune cells

Extracellular vesicle (EV)-mediated communication has been implicated in the cooperative alliance between trophoblast and immune cells toward maternal tolerance and placentation. Syncytiotrophoblast cells secrete EVs directly into the maternal circulation, which are taken up by immune cells, endothelial cells, and other cell types. Initial evidence also shows that EVs produced by immune cells are, in turn, incorporated by trophoblast cells and modulate placental responses. Non-coding RNAs (ncRNAs), proteins, and lipid mediators transported in EVs are able to influence proliferation, differentiation, cytokine production, and immunological responses of recipient cells. The molecular alphabet and cellular targets involved in this dialogue are being revealed. Nevertheless, several questions regarding the whole content, surface markers, and biological functions of EVs still remain to be investigated in both physiological and pathological conditions. Analysis of circulating EVs in maternal blood has the potential to serve as a minimally invasive approach to monitoring placental functions and immunological features of pregnancy, aiding in the diagnostics of complications. This review addresses the immunomodulatory properties of EVs and their tasks in the communication between placental and immune cells.

Expression Pattern of Seminal Plasma Extracellular Vesicle Small RNAs in Boar Semen

Extracellular vesicles (EVs) regulate multiple physiological processes. Seminal plasma contains numerous EVs that may deliver functional molecules such as small RNAs (sRNAs) to the sperm. However, the RNA profiles in the boar seminal plasma extracellular vesicles (SP-EVs) and its function have not been characterized. The aim of this study was to characterize the functions and sRNA profiles in the boar SP-EVs using deep sequencing technology. Briefly, boar SP-EVs were isolated by differential ultracentrifugation and confirmed with a transmission electron microscope (TEM), nanoparticle tracking analysis (NTA), and Western blot. The isolated boar SP-EVs contained numerous and diverse sRNA families, including microRNAs (miRNAs, 9.45% of the total reads), PIWI-interacting RNAs (piRNAs, 15.25% of the total reads), messenger RNA fragments (mRNA, 25.30% of the total reads), and tRNA-derived small RNAs (tsRNA, 0.01% of the total reads). A total of 288 known miRNAs, 37 novel miRNA, and 19,749 piRNAs were identified in boar SP-EVs. The identified ssc-miR-21-5p may confer negative effects on sperm fertility based on a dual-luciferase reporter experiment. This study therefore provides an effective method to isolate SP-EVs and characterizes the sRNA profile.