Extracellular vesicle isolation and characterization: toward clinical application

Periodontal ligament cells derived small extracellular vesicles are involved in orthodontic tooth movement

OBJECTIVES

Small extracellular vesicles (EVs) from human periodontal ligament cells (hPDLCs) are closely associated with periodontal homeostasis. Far less is known about EVs association with orthodontic tooth movement (OTM). This study aimed to explore the role of small EVs originated from hPDLCs during OTM.

MATERIALS AND METHODS

Adult C57BL/6 mice were used. Springs were bonded to the upper first molars of mice for 7 days to induce OTM in vivo. To block small EVs release, GW4869 was intraperitoneally injected and the efficacy of small EVs inhibition in periodontal ligament was verified by transmission electron microscope (TEM). Tooth movement distance and osteoclastic activity were studied. In vitro, hPDLCs were isolated and administered compressive force in the EV-free culture media. The cell morphologies and CD63 expression of hPDLCs were studied. Small EVs were purified and characterized using a scanning electron microscope, TEM, western blot, and nanoparticle tracking analysis. The expression of proteins in the small EVs was further processed and validated using a human immuno-regulated cytokines array and an enzyme-linked immunosorbent assay (ELISA).

RESULTS

The small EV depletion significantly decreased the distance and osteoclastic activity of OTM in the mice. The hPDLCs displayed different morphologies under force compression and CD63 expression level decreased verified by western blot and immunofluorescence staining. Small EVs purified from supernatants of the hPDLCs showed features with <200 nm diameter, the positive EVs marker CD63, and the negative Golgi body marker GM130. The number of small EVs particles increased in hPDLCs suffering force stimuli. According to the proteome array, the level of soluble intercellular adhesion molecule-1 (sICAM-1) displayed the most significant fold change in small EVs under compressive force and this was further confirmed using an ELISA.

LIMITATIONS

Further mechanism studies are warranted to validate the hPDLC-originated small EVs function in OTM through proteins delivery.

CONCLUSIONS

The notable decrease in the OTM distance after small EV blocking and the significant alteration of the sICAM-1 level in the hPDLC-originated small EVs under compression provide a new vista into small EV-related OTM biology.

Matrix Bound Nanovesicles have Tissue Specific Characteristics that Suggest a Regulatory Role

Recent studies have identified an extracellular vesicle population that is tightly anchored within the extracellular matrix of tissues and organs until released by matrix turnover events. Evidence suggests that these matrix-bound nanovesicles (MBV) are a ubiquitous component of the ECM, raising questions regarding their tissue specific identity and their biologic function(s). The primary objective of this study was to examine MBV isolated from six different tissues and compare their physical and compositional characteristics to determine the common and differentially expressed features. Accordingly, the results of this characterization show that while MBV are a ubiquitous component of the ECM they contain a protein and miRNA cargo that is tissue specific. The results furthermore suggest that MBV have an important role in regulating tissue homeostasis.

Overcoming the blood-brain barrier: Exosomes as theranostic nanocarriers for precision neuroimaging

Exosomes are cell-derived vesicles with a lipid bilayer membrane that play important roles in intercellular communication. They provide an unprecedented opportunity for the development of drug delivery nanoplatforms due to their low immunogenicity, low toxicity, biocompatibility, stability, and ability to change the functions of recipient cells. In addition, exosomes can penetrate the blood-brain barrier and then target and accumulate in relevant pathological brain regions. However, few studies have focused on the applications of exosomes as nanocarriers for use in precision neuroimaging studies. Thus, this report presents the feasibility of fabricating specific exosome-based diagnostic reagents for the application of personalized/precision radiology in the central nervous system based on important recent fundamental discoveries and technological advances.

Mesenchymal Stem Cell-Derived Extracellular Vesicles as Idiopathic Pulmonary Fibrosis Microenvironment Targeted Delivery

Idiopathic pulmonary fibrosis (IPF) affects an increasing number of people globally, yet treatment options remain limited. At present, conventional treatments depending on drug therapy do not show an ideal effect in reversing the lung damage or extending the lives of IPF patients. In recent years, more and more attention has focused on extracellular vesicles (EVs) which show extraordinary therapeutic effects in inflammation, fibrosis disease, and tissue damage repair in many kinds of disease therapy. More importantly, EVs can be modified or used as a drug or cytokine delivery tool, targeting injury sites to enhance treatment efficiency. In light of this, the treatment strategy of mesenchymal stem cell-extracellular vesicles (MSC-EVs) targeting the pulmonary microenvironment for IPF provides a new idea for the treatment of IPF. In this review, we summarized the inflammation, immune dysregulation, and extracellular matrix microenvironment (ECM) disorders in the IPF microenvironment in order to reveal the treatment strategy of MSC-EVs targeting the pulmonary microenvironment for IPF.

Mesenchymal stem cells exert renoprotection via extracellular vesicle-mediated modulation of M2 macrophages and spleen-kidney network

Adipose-derived mesenchymal stem cells (ASCs) have shown therapeutic potentials against refractory diseases. However, the detailed therapeutic mechanisms remain unclear. Here, we report the therapeutic actions of human ASCs in nephritis, focusing on cellular dynamics and multi-organ networks. Intravenously-administered ASCs accumulated in spleen but not kidneys. Nevertheless, ASCs increased M2 macrophages and Tregs in kidneys and drove strong renoprotection. Splenectomy abolished these therapeutic effects. ASC-derived extracellular vesicles (EVs) were transferred to M2 macrophages, which entered the bloodstream from spleen. EVs induced the transcriptomic signatures of hyperpolarization and PGE2 stimulation in M2 macrophages and ameliorated glomerulonephritis. ASCs, ASC-derived EVs, and EV-transferred M2 macrophages enhanced Treg induction. These findings suggest that EV transfer from spleen-accumulated ASCs to M2 macrophages and subsequent modulation of renal immune-environment underlie the renoprotective effects of ASCs. Our results provide insights into the therapeutic actions of ASCs, focusing on EV-mediated modulation of macrophages and the spleen-kidney immune network.

The renoprotective effects of adipose-derived mesenchymal stem cells (ASCs) are enhanced through the transfer of EVs predominantly to M2 macrophages in the spleen, providing insights into therapeutic avenues for ASCs.

Effects of Exosomal Viral Components on the Tumor Microenvironment

Simple Summary

Oncogenic viral infection may lead to cancers, such as nasopharyngeal carcinoma, hepatocellular carcinoma, and cervical cancer. In addition to the tumor cells themselves, the tumor microenvironment also plays a decisive role in tumor evolution. Oncogenic viruses can affect the tumor microenvironment via exosomes influencing the occurrence and development of tumors by encapsulating and transporting viral components. This review focuses on the effects of virus-infected cancer exosomes on tumor microenvironment and tumor progression.

Abstract

Exosomes are extracellular membrane vesicles with a diameter of 30–100 nm, produced by different eukaryotic cells that contain multitudinous lipids, nucleic acids, and proteins. They transfer membrane components and nucleic acids between cells, thereby performing an information exchange between cells. Many studies have shown that a variety of tumor-associated viruses can exert their biological functions through exosomes. The tumor microenvironment (TME) is very important in the occurrence, development, and chemoresistance of tumors. It is composed of tumor cells, fibroblasts, endothelial cells, immune cells, stromal cells, and acellular components, such as exosomes and cytokines. This review focuses on the effects of virus-related components secreted by tumor cells over the TME in several virus-associated cancers.

Circulating Exosome Cargoes Contain Functionally Diverse Cancer Biomarkers: From Biogenesis and Function to Purification and Potential Translational Utility

Although diagnostic and therapeutic treatments of cancer have tremendously improved over the past two decades, the indolent nature of its symptoms has made early detection challenging. Thus, inter-disciplinary (genomic, transcriptomic, proteomic, and lipidomic) research efforts have been focused on the non-invasive identification of unique "silver bullet" cancer biomarkers for the design of ultra-sensitive molecular diagnostic assays. Circulating tumor biomarkers, such as CTCs and ctDNAs, which are released by tumors in the circulation, have already demonstrated their clinical utility for the non-invasive detection of certain solid tumors. Considering that exosomes are actively produced by all cells, including tumor cells, and can be found in the circulation, they have been extensively assessed for their potential as a source of circulating cell-specific biomarkers. Exosomes are particularly appealing because they represent a stable and encapsulated reservoir of active biological compounds that may be useful for the non-invasive detection of cancer. T biogenesis of these extracellular vesicles is profoundly altered during carcinogenesis, but because they harbor unique or uniquely combined surface proteins, cancer biomarker studies have been focused on their purification from biofluids, for the analysis of their RNA, DNA, protein, and lipid cargoes. In this review, we evaluate the biogenesis of normal and cancer exosomes, provide extensive information on the state of the art, the current purification methods, and the technologies employed for genomic, transcriptomic, proteomic, and lipidomic evaluation of their cargoes. Our thorough examination of the literature highlights the current limitations and promising future of exosomes as a liquid biopsy for the identification of circulating tumor biomarkers.

Parasitic helminths and the host microbiome - a missing 'extracellular vesicle-sized' link?

Infections by gastrointestinal (GI) helminths have been associated with significant alterations of the structure of microbial communities inhabiting the host gut. However, current understanding of the biological mechanisms that regulate these relationships is still lacking. We propose that helminth-derived extracellular vesicles (EVs) likely represent key players in helminth-microbiota crosstalk. Here, we explore knowledge of helminth EVs with an emphasis on their putative antimicrobial properties, and we argue that (i) an enhanced understanding of the mechanisms governing such interactions might assist the discovery and development of novel strategies of parasite control, and that (ii) the identification and characterisation of helminth molecules with antimicrobial properties might pave the way towards the discovery of novel antibiotics, thus aiding the global fight against antimicrobial resistance.

The Antisenescence Effect of Exosomes from Human Adipose-Derived Stem Cells on Skin Fibroblasts

Human adipose-derived stem cells (ADSCs) have become a promising therapeutic approach against skin aging. Recent studies confirm that exosomes partially mediate the therapeutic effect of stem cells. This study successfully isolated exosomes from the ADSC culture medium and discovered that ADSC-derived exosomes (ADSC-Exos) could alleviate human dermal fibroblast (HDF) senescence and stimulate HDF migration. Moreover, ADSC-Exos increased the type I collagen expression level and reduced the reactive oxygen species (ROS) and senescence-associated β-galactosidase (SA-β-Gal) activity in HDFs. In addition, we demonstrated that ADSC-Exos significantly inhibited senescence-related protein expression levels of p53, p21, and p16. In conclusion, our results have revealed the antisenescence effects of ADSC-Exos on HDFs and ADSC-Exos may be a novel cell-free therapeutic tool for antiaging.

Comparison of serum and plasma as a source of blood extracellular vesicles: Increased levels of platelet-derived particles in serum extracellular vesicle fractions alter content profiles from plasma extracellular vesicle fractions

Extracellular vesicles (EVs) have attracted much attention as potential diagnostic biomarkers for human diseases. Although both plasma and serum are utilized as a source of blood EVs, it remains unclear whether, how and to what extent the choice of plasma and serum affects the experimental results. To address this issue, in this study, we performed comprehensive characterization of EV fractions derived from plasma and serum, and investigated the differences between these blood EVs. We demonstrated by nanoparticle tracking analysis that EV fractions derived from serum contain more particles than those from plasma of mice. Proteomic analysis demonstrated that platelet-associated proteins are selectively enriched in serum EV fractions from both mice and humans. A literature review of proteomic data of human blood EVs reported by other groups further confirmed that selective enrichment of platelet-associated proteins is commonly observed in serum EVs, and confers different proteome profiles to plasma EVs. Our data provide experimental evidence that EV fractions derived from serum generally contain additional EVs that are released from platelets, which may qualitatively and quantitatively alter EV profiles when using serum as a source of blood EVs.

Exosome-mediated remodeling of the tumor microenvironment: From local to distant intercellular communication

Extracellular vesicles (EVs) are membrane-enveloped nanoscale particles that carry various bioactive signaling molecules secreted by cells. Their biological roles depend on the original cell type from which they are derived and their inclusions. Exosomes, a class of EVs, are released by almost all eukaryotic cell types, including tumor cells. Tumor cell-derived exosomes mediate signal transduction between tumor cells and surrounding non-tumor cells. This intercellular communication actively contributes to the remodeling of the tumor microenvironment (TME) to enable tumor growth, invasion, and metastasis. This review summarizes the latest progress in the exploration of exosome-mediated cell-cell communication implicated in TME remodeling and underlying mechanisms. We focus on the role of cell-cell interactions mediated by tumor cell-derived exosomes in promoting invasion and metastasis, and their potential as a therapeutic intervention target against distant metastasis. We also discuss the clinical translational significance of tumor-derived exosomes for early diagnosis, efficacy and progression evaluations.

The role of extracellular vesicles in animal reproduction and diseases

Extracellular vesicles (EVs) are nanosized membrane-enclosed compartments that serve as messengers in cell-to-cell communication, both in normal physiology and in pathological conditions. EVs can transfer functional proteins and genetic information to alter the phenotype and function of recipient cells, which undergo different changes that positively affect their structural and functional integrity. Biological fluids are enriched with several subpopulations of EVs, including exosomes, microvesicles (MVs), and apoptotic bodies carrying several cargoes, such as lipids, proteins, and nucleic acids. EVs associated with the reproductive system are actively involved in the regulation of different physiological events, including gamete maturation, fertilization, and embryo and fetal development. EVs can influence follicle development, oocyte maturation, embryo production, and endometrial-conceptus communication. EVs loaded with cargoes are used to diagnose various diseases, including pregnancy disorders; however, these are dependent on the type of cell of origin and pathological characteristics. EV-derived microRNAs (miRNAs) and proteins in the placenta regulate inflammatory responses and trophoblast invasion through intercellular delivery in the placental microenvironment. This review presents evidence regarding the types of extracellular vesicles, and general aspects of isolation, purification, and characterization of EVs, particularly from various types of embryos. Further, we discuss EVs as mediators and messengers in reproductive biology, the effects of EVs on placentation and pregnancy disorders, the role of EVs in animal reproduction, in the male reproductive system, and mother and embryo cross-communication. In addition, we emphasize the role of microRNAs in embryo implantation and the role of EVs in reproductive and therapeutic medicine. Finally, we discuss the future perspectives of EVs in reproductive biology.

Roles and Applications of Red Blood Cell-Derived Extracellular Vesicles in Health and Diseases

Red blood cell-derived extracellular vesicles (RBCEVs) are vesicles naturally produced by red blood cells and play multiple roles such as acting as cell-to-cell communication messengers in both normal physiological and diseased states. RBCEVs are highly promising delivery vehicles for therapeutic agents such as biomolecules and nucleic acids as they are easy to source, safe, and versatile. RBCEVs autonomously target the liver and pass the blood-brain barrier into the brain, which is highly valuable for the treatment of liver and brain diseases. RBCEVs can be modified by various functional units, including various functional molecules and nanoparticles, to improve their active targeting capabilities for tumors or other sites. Moreover, the RBCEV level is significantly shifted in many diseased states; hence, they can also serve as important biomarkers for disease diagnoses. It is clear that RBCEVs have considerable potential in multiple medical applications. In this review, we briefly introduce the biological roles of RBCEVs, presented interesting advances in RBCEV applications, and discuss several challenges that need to be addressed for their clinical translation.

Characterisation of Extracellular Vesicles from Equine Mesenchymal Stem Cells

Extracellular vesicles (EVs) are nanosized lipid bilayer-encapsulated particles secreted by virtually all cell types. EVs play an essential role in cellular crosstalk in health and disease. The cellular origin of EVs determines their composition and potential therapeutic effect. Mesenchymal stem/stromal cell (MSC)-derived EVs have shown a comparable therapeutic potential to their donor cells, making them a promising tool for regenerative medicine. The therapeutic application of EVs circumvents some safety concerns associated with the transplantation of viable, replicating cells and facilitates the quality-controlled production as a ready-to-go, off-the-shelf biological therapy. Recently, the International Society for Extracellular Vesicles (ISEV) suggested a set of minimal biochemical, biophysical and functional standards to define extracellular vesicles and their functions to improve standardisation in EV research. However, nonstandardised EV isolation methods and the limited availability of cross-reacting markers for most animal species restrict the application of these standards in the veterinary field and, therefore, the species comparability and standardisation of animal experiments. In this study, EVs were isolated from equine bone-marrow-derived MSCs using two different isolation methods, stepwise ultracentrifugation and size exclusion chromatography, and minimal experimental requirements for equine EVs were established and validated. Equine EVs were characterised using a nanotracking analysis, fluorescence-triggered flow cytometry, Western blot and transelectron microscopy. Based on the ISEV standards, minimal criteria for defining equine EVs are suggested as a baseline to allow the comparison of EV preparations obtained by different laboratories.

αvβ3-targeted sEVs for efficient intracellular delivery of proteins using MFG-E8

BACKGROUND

Small extracellular vesicles (sEVs) are nanometer-sized membranous particles shed by many types of cells and can transfer a multitude of cargos between cells. Recent studies of sEVs have been focusing on their potential to be novel drug carriers due to natural composition and other promising characteristics. However, there are challenges in sEVs-based drug delivery, one of which is the inefficient loading of drugs into sEVs, especially for large biomolecules.

RESULTS

In this study, we proposed a membrane-associated protein, milk fat globule-epidermal growth factor 8 protein (MFG-E8), to produce αvβ3-targeted sEVs with high delivery efficiency of interested protein. MFG-E8 is a secreted protein with NH2-terminal epidermal growth factor (EGF)-like domains, containing an Arg-Gly-Asp(RGD) sequence that binds αvβ3 and αvβ5 integrins, and COOH terminal domains C1 and C2, which can bind to lipid membrane with strong affinity. Firstly, we transiently expressed MFG-E8 in HEK293F cells and found that this protein could be secreted and adhere to the cell membrane. The recombinant MFG-E8 is also found to locate at the outer membrane of sEVs. Then we generated engineered sEVs by expressing high levels of the EGFP fused to MFG-E8 in HEK293F cells and showed that MFG-E8 could increase the delivery efficiency of EGFP into sEVs. Further delivery of Gaussia luciferase (GL) by fusion expression with MFG-E8 in donor cells demonstrated that target proteins fused with MFG-E8 still kept their activity. Finally, we identified the sEVs' target to integrin αvβ3 by comparing the transfection efficiency with MFG-E8 loaded sEVs (MFG-E8-sEVs) in αvβ3 positive cells and αvβ3 negative cells. Analysis showed higher target protein could transfect into αvβ3 positive cells with MFG-E8-sEVs than with EGFP loaded sEVs (EGFP-sEVs), meaning the engineered sEVs with MFG-E8 not only could increase the delivery of target protein into sEVs, but also could target the αvβ3 positive cells.

CONCLUSION

This study suggests that recombinant MFG-E8 is an ideal protein to increasingly deliver the drug into sEVs and give sEVs the ability to target the αvβ3 positive cells.

The role of extracellular vesicles in endometrial receptivity and their potential in reproductive therapeutics and diagnosis

Extracellular vesicles (EVs) are small, nanometre sized, membrane-enclosed structures released by cells and are thought to be crucial in cellular communication. The cargo of these vesicles includes lipids, proteins, RNAs and DNA, and control various biological processes in their target tissues depending on the parental and receiver cell's origin and phenotype. Recently data has accumulated in the role of EVs in embryo implantation and pregnancy, with EVs identified in the uterine cavity of women, sheep, cows, horses, and mice, in which they aid blastocyst and endometrial preparation for implantation. Herein is a critical review to decipher the role of extracellular vesicles in endometrial receptivity and their potential in reproductive therapies and diagnosis. The current knowledge of the function of embryo and endometrial derived EVs and their cargoes, with regards to their effect on implantation and receptivity are summarized and evaluated. The findings of the below review highlight that the combined knowledge on EVs deriving from the endometrium and embryo have the potential to be translated to various clinical applications including treatment, a diagnostic biomarker for diseases and a drug delivery tool to ultimately improve pregnancy rates.

Current understanding of extracellular vesicle homing/tropism

Extracellular vesicles (EVs) are membrane-enclosed packets released from cells that can transfer bioactive molecules from cell to cell without direct contact with the target cells. This transfer of molecules can activate consequential processes in the recipient cells, including cell differentiation and migration that maintain tissue homeostasis or promote tissue pathology. One controversial aspect of the EV's biology that holds therapeutic promise is their capacity to engage defined cells at specific sites. On the one hand, persuasive studies have shown that EVs express surface molecules that ensure their tissue localization and enable cell-specific interactions, as demonstrated using in vitro and in vivo analyses. Therefore, this feature of EV biology is under investigation in translational studies to control malignancies and deliver chemicals and bioactive molecules to combat several diseases. On the other hand, some studies have shown that EVs fail to traffic in hosts in a targeted manner, which questions the potential role of EVs as vehicles for drug delivery and their capacity to serve as cell-free biomodulators. In this review, the biology of EV homing/tropism in mammalian hosts is discussed, and the biological characteristics that may result in their controversial characteristics are brought to the fore.

Osteoblast Derived Exosomes Alleviate Radiation- Induced Hematopoietic Injury

As hematopoietic stem cells can differentiate into all hematopoietic lineages, mitigating the damage to hematopoietic stem cells is important for recovery from overdose radiation injury. Cells in bone marrow microenvironment are essential for hematopoietic stem cells maintenance and protection, and many of the paracrine mediators have been discovered in shaping hematopoietic function. Several recent reports support exosomes as effective regulators of hematopoietic stem cells, but the role of osteoblast derived exosomes in hematopoietic stem cells protection is less understood. Here, we investigated that osteoblast derived exosomes could alleviate radiation damage to hematopoietic stem cells. We show that intravenous injection of osteoblast derived exosomes promoted WBC, lymphocyte, monocyte and hematopoietic stem cells recovery after irradiation significantly. By sequencing osteoblast derived exosomes derived miRNAs and verified in vitro, we identified miR-21 is involved in hematopoietic stem cells protection via targeting PDCD4. Collectively, our data demonstrate that osteoblast derived exosomes derived miR-21 is a resultful regulator to radio-protection of hematopoietic stem cells and provide a new strategy for reducing radiation induced hematopoietic injury.

Insight into Extracellular Vesicle-Cell Communication: From Cell Recognition to Intracellular Fate

Extracellular vesicles (EVs) are heterogamous lipid bilayer-enclosed membranous structures secreted by cells. They are comprised of apoptotic bodies, microvesicles, and exosomes, and carry a range of nucleic acids and proteins that are necessary for cell-to-cell communication via interaction on the cells surface. They initiate intracellular signaling pathways or the transference of cargo molecules, which elicit pleiotropic responses in recipient cells in physiological processes, as well as pathological processes, such as cancer. It is therefore important to understand the molecular means by which EVs are taken up into cells. Accordingly, this review summarizes the underlying mechanisms involved in EV targeting and uptake. The primary method of entry by EVs appears to be endocytosis, where clathrin-mediated, caveolae-dependent, macropinocytotic, phagocytotic, and lipid raft-mediated uptake have been variously described as being prevalent. EV uptake mechanisms may depend on proteins and lipids found on the surfaces of both vesicles and target cells. As EVs have been shown to contribute to cancer growth and progression, further exploration and targeting of the gateways utilized by EVs to internalize into tumor cells may assist in the prevention or deceleration of cancer pathogenesis.

The implications of exosomes in pregnancy: emerging as new diagnostic markers and therapeutics targets

Extracellular vehicles (EVs) are a heterogeneous group of cell and membranous particles originating from different cell compartments. EVs participate in many essential physiological functions and mediate fetal-maternal communications. Exosomes are the smallest unit of EVs, which are delivered to the extracellular space. Exosomes can be released by the umbilical cord, placenta, amniotic fluid, and amniotic membranes and are involved in angiogenesis, endothelial cell migration, and embryo implantation. Also, various diseases such as gestational hypertension, gestational diabetes mellitus (GDM), preterm birth, and fetal growth restriction can be related to the content of placental exosomes during pregnancy. Due to exosomes' ability to transport signaling molecules and their effect on sperm function, they can also play a role in male and female infertility. In the new insight, exosomal miRNA can diagnose and treat infertilities disorders. In this review, we focused on the functions of exosomes during pregnancy.

Engineered exosomes as a photosensitizer delivery platform for cancer photodynamic therapy

Photodynamic therapy (PDT), a non/minimally invasive cancer treatment method, has the advantages of low side effects, high selectivity, and low drug resistance. It is currently a popular cancer treatment method. However, the shortcomings of photosensitizers such as poor photostability, poor water solubility, and short half-life in vivo when used alone, the development of photosensitizer nano-delivery platforms have always been a research hotspot. In the human body, various types of cells generally release exosomes, the bilayer extracellular vesicles. Compared with traditional materials, exosomes are currently an ideal drug delivery platform due to their homology, low immunogenicity, easy modification, high biocompatibility, and natural carrying capacity. Therefore, in this concept, we focus on the research status and prospects of engineered exosome-based photosensitizer nano-delivery platforms in cancer PDT.

Edible plant-derived nanotherapeutics and nanocarriers: recent progress and future directions

INTRODUCTION

High drug delivery efficiency, desirable therapeutic effects, and low toxicity have become crucial to develop nanotherapeutics. Natural nanoparticles (NPs) from edible plants contain a large quantity of bioactive small molecules, proteins, glycolipids, and microRNAs. The development of these NPs has rapidly attracted increasing attention due to their merits of green production, excellent biocompatibility, anti-inflammatory activities, and antitumor capacities.

AREAS COVERED

Here, we introduce the extraction, purification, and construction strategies of plant-derived exosome-like NPs (PDENs) and expound on their physicochemical properties, biomedical functions, and therapeutic effects against various diseases. We also recapitulate future directions and challenges of the emerging nanotherapeutics.

EXPERT OPINION

PDENs have been used as natural nanotherapeutics and nanocarriers. The challenges of applying PDENs primarily stem from the lack of understanding of the mechanisms that drive the tissue-specific targeting properties. Elucidating the underlying targeting mechanisms is one of the major focuses in this review, which helps to gain new research opportunities for the development of natural nanotherapeutics. Despite excellent biosafety and therapeutic effects in the treatment of various diseases, the medical translation of these NPs has still been limited by low yields and cold-chain dependence. Therefore, exploiting new techniques will be required for their massive production and storage.

A Brief Overview of Global Trends in MSC-Based Cell Therapy

Human mesenchymal stem cells (MSCs), also known as mesenchymal stromal cells or medicinal signaling cells, are important adult stem cells for regenerative medicine, largely due to their regenerative characteristics such as self-renewal, secretion of trophic factors, and the capability of inducing mesenchymal cell lineages. MSCs also possess homing and trophic properties modulating immune system, influencing microenvironment around damaged tissues and enhancing tissue repair, thus offering a broad perspective in cell-based therapies. Therefore, it is not surprising that MSCs have been the broadly used adult stem cells in clinical trials. To gain better insights into the current applications of MSCs in clinical applications, we perform a comprehensive review of reported data of MSCs clinical trials conducted globally. We summarize the biological effects and mechanisms of action of MSCs, elucidating recent clinical trials phases and findings, highlighting therapeutic effects of MSCs in several representative diseases, including neurological, musculoskeletal diseases and most recent Coronavirus infectious disease. Finally, we also highlight the challenges faced by many clinical trials and propose potential solutions to streamline the use of MSCs in routine clinical applications and regenerative medicine.

Lipidomic analysis identifies age-disease-related changes and potential new biomarkers in brain-derived extracellular vesicles from metachromatic leukodystrophy mice

BACKGROUND

Recent findings show that extracellular vesicle constituents can exert short- and long-range biological effects on neighboring cells in the brain, opening an exciting avenue for investigation in the field of neurodegenerative diseases. Although it is well documented that extracellular vesicles contain many lipids and are enriched in sphingomyelin, cholesterol, phosphatidylserines and phosphatidylinositols, no reports have addressed the lipidomic profile of brain derived EVs in the context of Metachromatic Leukodystrophy, a lysosomal storage disease with established metabolic alterations in sulfatides.

METHODS

In this study, we isolated and characterized the lipid content of brain-derived EVs using the arylsulfatase A knockout mouse as a model of the human condition.

RESULTS

Our results suggest that biogenesis of brain-derived EVs is a tightly regulated process in terms of size and protein concentration during postnatal life. Our lipidomic analysis demonstrated that sulfatides and their precursors (ceramides) as well as other lipids including fatty acids are altered in an age-dependent manner in EVs isolated from the brain of the knockout mouse.

CONCLUSIONS

In addition to the possible involvement of EVs in the pathology of Metachromatic Leukodystrophy, our study underlines that measuring lipid signatures in EVs may be useful as biomarkers of disease, with potential application to other genetic lipidoses.

Distinguishing functional exosomes and other extracellular vesicles as a nucleic acid cargo by the anion-exchange method

The development of a new large‐scale purification protocol is required for research on the reliable bioactivity and drug discovery of extracellular vesicles (EVs). To address this issue, herein, we propose an effective method for preparing high‐performance exosomes (EXOs) by using an anion‐exchange method. Cytotoxic T‐lymphocyte (CTL) EVs from 4 L of culture supernatant through a 220 nm cut‐off filter are divided into two populations at a deproteinization rate of over 99.97%, which are eluted at low (0.15 M–0.3 M) and high (0.3 M–0.5 M) NaCl concentrations (approximately 2 × 10¹² and 1.5 × 10¹² particles, respectively) through the anion‐exchange column chromatography. The former are abundant in EXO proteins, including late endosome‐associated proteins and rab‐family and integrin‐family proteins, and functional micro (mi) RNAs, and have bioactivity for preventing tumour metastasis by depleting mesenchymal cell populations in the primary tumour lesions. By contrast, the latter is microvesicle (MV)‐like particles including DNA, core histone and ribosomal proteins, and GC‐rich miRNAs with unknown function, and are easily phagocytosed by mannose receptor⁺ Kupffer cells. Thus, the anion‐exchange method is suitable for the large‐scale separation of bioactive EXOs and MV‐like EVs as a cargo for dangerous nucleic acids at high‐purity.

Extracellular Vesicle-Derived miR-105-5p Promotes Malignant Phenotypes of Esophageal Squamous Cell Carcinoma by Targeting SPARCL1 via FAK/AKT Signaling Pathway

Objective: Esophageal squamous cell carcinoma (ESCC) presents high morbidity and mortality. It was demonstrated that blood-derived vesicles can facilitate ESCC development and transmit regulating signals. However, the molecular mechanism of vesicle miRNA secreted by tumor cells affecting ESCC progression has not been explored.

Methods: The mRNA-related signaling pathways and differentially expressed genes were screened out in TCGA dataset. The levels of miRNA-105-5p and SPARCL1 were determined by qRT-PCR. Protein level determination was processed using Western blot. The interaction between the two genes was verified with the dual-luciferase method. A transmission electron microscope was utilized to further identify extracellular vesicles (EVs), and co-culture assay was performed to validate the intake of EVs. In vitro experiments were conducted to evaluate cell function changes in ESCC. A mice tumor formation experiment was carried out to observe tumor growth in vivo.

Results: MiRNA-105-5p expression was increased in ESCC, while SPARCL1 was less expressed. MiRNA-105-5p facilitated cell behaviors in ESCC through targeting SPARCL1 and regulating the focal adhesion kinase (FAK)/Akt signaling pathway. Blood-derived external vesicles containing miRNA-105-5p and EVs could be internalized by ESCC cells. Then, miRNA-105-5p could be transferred to ESCC cells to foster tumorigenesis as well as cell behaviors.

Conclusion: EV-carried miRNA-105-5p entered ESCC cells and promoted tumor-relevant functions by mediating SPARCL1 and the FAK/Akt signaling pathway, which indicated that the treatment of ESCC via serum EVs might be a novel therapy and that miRNA-105-5p can be a molecular target for ESCC therapy.

Application of engineered extracellular vesicles for targeted tumor therapy

All cells, including prokaryotes and eukaryotes, could release extracellular vesicles (EVs). EVs contain many cellular components, including RNA, and surface proteins, and are essential for maintaining normal intercellular communication and homeostasis of the internal environment. EVs released from different tissues and cells exhibit excellent properties and functions (e.g., targeting specificity, regulatory ability, physical durability, and immunogenicity), rendering them a potential new option for drug delivery and precision therapy. EVs have been demonstrated to transport antitumor drugs for tumor therapy; additionally, EVs' contents and surface substance can be altered to improve their therapeutic efficacy in the clinic by boosting targeting potential and drug delivery effectiveness. EVs can regulate immune system function by affecting the tumor microenvironment, thereby inhibiting tumor progression. Co-delivery systems for EVs can be utilized to further improve the drug delivery efficiency of EVs, including hydrogels and liposomes. In this review, we discuss the isolation technologies of EVs, as well as engineering approaches to their modification. Moreover, we evaluate the therapeutic potential of EVs in tumors, including engineered extracellular vesicles and EVs' co-delivery systems.

Technologies such as microfluidics can improve EVs isolation efficiency.

Engineering technologies can improve EVs drug loading efficiency and tumor targeting.

EVs-based drug co-delivery systems are being developed, such as those with liposomes and hydrogels.

Extracellular Vesicles—New Players in Cell-To-Cell Communication in Gestational Diabetes Mellitus

Research in extracellular vesicles (EVs) has contributed to a better understanding of physiological and pathophysiological conditions. Biologically active cargo, such as miRNAs and proteins, is critical in many different biological processes. In this context, pregnancy is one of the most complex physiological states, which needs a highly regulated system to ensure the correct nourishment and development of the baby. However, pre-existent maternal conditions and habits can modify the EV-cargo and dysregulate the system leading to pregnancy complications, with gestational diabetes mellitus (GDM) being one of the most reported and influential. Calcification and aging of muscle cells, protein modification in vascular control or variations in the levels of specific miRNAs are some of the changes observed or led by EV populations as adaptation to GDM. Interestingly, insulin sensitivity and glucose tolerance changes are not fully understood to date. Nevertheless, the increasing evidence generated has opened new possibilities in the biomarker discovery field but also in the understanding of cellular mechanisms modified and involved in GDM. This brief review aims to discuss some of the findings in GDM and models used for that purpose and their potential roles in the metabolic alterations during pregnancy, with a focus on insulin sensitivity and glucose tolerance.

Exosomal circLPAR1 functions in colorectal cancer diagnosis and tumorigenesis through suppressing BRD4 via METTL3–eIF3h interaction

Background

Exosomes have emerged as vital biomarkers of multiple cancers and contain abundant circular RNAs (circRNAs). However, the potential for exosomal circRNAs to be used in diagnostics and their molecular mechanism of action in colorectal cancer (CRC) remain unclear.

Methods

CRC-specific exosomal circRNAs were identified by RNA sequencing, exoRBase database and a tissue microarray. The diagnostic performance of plasma exosomal circRNAs was evaluated among cancer-free controls, precancer individuals, CRC patients, and patients with other types of cancer. The corresponding biological functions were mainly assessed using circRNA pull-down, proteomic analysis, and RNA immunoprecipitation assay underlying cellular and mouse models.

Results

CircLPAR1 was encapsulated in exosomes with high stability and detectability, and its expression in plasma exosomes was remarkably decreased during CRC development but recovered after surgery. Exosomal circLPAR1 showed cancer specificity in CRC diagnosis and increased the diagnostic performance to an area under the receiver operating characteristic curve of 0.875, as determined by analysing its performance in combination with common clinical biomarkers CEA and CA19–9. Additionally, circLPAR1 was downregulated in CRC tissues and was associated with overall survival. Mechanistically, exosomal circLPAR1 was internalized by CRC cells, and it suppressed tumor growth, likely because exosomal circLPAR1 directly bound with eIF3h specifically suppressed the METTL3-eIF3h interaction, decreasing the translation of oncogene BRD4.

Conclusions

This comprehensive study highlights plasma exosomal circLPAR1 as a promising predictor in CRC diagnosis and describes its biological regulation of colorectal tumorigenesis. This study provides a new perspective on early diagnosis in the clinic and pathogenesis in disease development.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12943-021-01471-y.

Phosphoproteomic Analysis of Breast Cancer-Derived Small Extracellular Vesicles Reveals Disease-Specific Phosphorylated Enzymes

Small membrane-derived extracellular vesicles have been proposed as participating in several cancer diseases, including breast cancer (BC). We performed a phosphoproteomic analysis of breast cancer-derived small extracellular vesicles (sEVs) to provide insight into the molecular and cellular regulatory mechanisms important for breast cancer tumor progression and metastasis. We examined three cell line models for breast cancer: MCF10A (non-malignant), MCF7 (estrogen and progesterone receptor-positive, metastatic), and MDA-MB-231 (triple-negative, highly metastatic). To obtain a comprehensive overview of the sEV phosphoproteome derived from each cell line, effective phosphopeptide enrichment techniques IMAC and TiO2, followed by LC-MS/MS, were performed. The phosphoproteome was profiled to a depth of 2003 phosphopeptides, of which 207, 854, and 1335 were identified in MCF10A, MCF7, and MDA-MB-231 cell lines, respectively. Furthermore, 2450 phosphorylation sites were mapped to 855 distinct proteins, covering a wide range of functions. The identified proteins are associated with several diseases, mostly related to cancer. Among the phosphoproteins, we validated four enzymes associated with cancer and present only in sEVs isolated from MCF7 and MDA-MB-231 cell lines: ATP citrate lyase (ACLY), phosphofructokinase-M (PFKM), sirtuin-1 (SIRT1), and sirtuin-6 (SIRT6). With the exception of PFKM, the specific activity of these enzymes was significantly higher in MDA-MB-231 when compared with MCF10A-derived sEVs. This study demonstrates that sEVs contain functional metabolic enzymes that could be further explored for their potential use in early BC diagnostic and therapeutic applications.

Differential Size Distribution and Estrogen Receptor Cargo of Oviductal Extracellular Vesicles at Various Stages of Estrous Cycle in Mice

Oviductal extracellular vesicles (OEVs) play an important role in fertilization and embryo development. However, it remains largely unknown whether the size and protein cargo of OEVs change during the estrous cycle in mice. This study analyzed the changes in the size distribution and protein cargo of OEVs at four stages of the estrous cycle in mice. The distribution widths of OEVs according to the estrous cycle stage were as follows: proestrus, 20–690 nm in diameter, with two peaks at 50 and 250 nm; estrus, 22–420 nm in diameter, with two peaks at 40 and 200 nm; metestrus, 30–70 nm diameter, with a single peak at 40 nm; and diestrus, 10–26 nm diameter, with a single peak at 20 nm. The estrogen receptor (ER) level in OEVs at the proestrus stage differed significantly from that at estrus (P = 0.013) and diestrus (P = 0.005). The levels of CD9 and Hsc70 fluctuated across the four stages, although with no significant differences. Furthermore, OEVs were observed among the cilia and microvilli of epithelial cells at the proestrus, estrus, and diestrus stages, but not at the metestrus stage. The number of observed OEVs was the highest at the proestrus stage, followed by the estrus, and the diestrus stage. Endosomes were also observed at the estrus and diestrus stages. The change of the OEV size and ER cargo is associated with the estrous cycle in mice. Our findings increase the understanding of the physiological characteristics of OEVs, which may have clinical applications.

Stimuli-Mediated Specific Isolation of Exosomes from Blood Plasma for High-Throughput Profiling of Cancer Biomarkers

Exosomes, ranging from 30-150 nm in diameter, have emerged as promising non-invasive biomarkers for the diagnosis and prognosis of numerous diseases. However, current research on exosomes is largely restricted by the lack of an efficient method to isolate exosomes from real samples. Herein, the first stimuli-mediated enrichment and purification system to selectively and efficiently extract exosomes from clinical plasma for high-throughput profiling of exosomal mRNAs as cancer biomarkers is presented. This novel isolation system relies on specific installation of the stimuli-responsive copolymers onto exosomal phospholipid bilayers, by which the enrichment and purification are exclusively achieved for exosomes rather than the non-vesicle counterparts co-existing in real samples. The stimuli-mediated isolation system outperforms conventional methods such as ultracentrifugation and polyethylene glycol-based precipitation in terms of isolation yield, purity, and retained bioactivity. The high performance of the isolation system is demonstrated by enriching exosomes from 77 blood plasma samples and validated the clinical potentials in profiling exosomal mRNAs for cancer diagnosis and discrimination with high accuracy. This simple isolation system can boost the development of extracellular vesicle research, not limited to exosomes, in both basic and clinical settings.

Extracellular Vesicles Generated Using Bioreactors and their Therapeutic Effect on the Acute Kidney Injury Model

Extracellular vesicles (EVs) are nano-sized vesicles secreted by cells, having beneficial effects for various types of regenerative processes. Although EVs have shown promising effects as therapeutic agents, these effects are difficult to research due to the limitations of EV production. In this study, an EV production method based on a flat-plate bioreactor is introduced. The bioreactor produces approximately seven times more mesenchymal stem cell-derived EVs than static culture conditions. The mechanism underlying the increased production of EVs in a flat-plate bioreactor and its application to acute kidney injury is investigated. This study describes the mechanism of EV production by demonstrating the link between EV biogenesis and increased calcium ion concentration under flow conditions. EVs secreted by cells cultured in the bioreactor have therapeutic efficacy in terms of improving kidney damage, resulting in tissue regeneration in a cisplatin-induced acute kidney injury model. This method will help overcome the limitations of EV production, and the analysis of the application of EVs will increase their reliability as well as the understanding of the use of bioreactor-derived EVs as therapeutic agents.

Heterotopic ossification vs. fracture healing: Extracellular vesicle cargo proteins shed new light on bone formation

Fibrodysplasia ossificans progressiva (FOP) is an extremely rare disease in which bone tissue forms in extraskeletal sites, which is known as heterotopic ossification (HO). Extracellular vesicles (EVs) are small phospholipid-enclosed particles released by various cells which have an emerging, but not completely understood role in various (patho)physiological processes. In order to further study the pathophysiology of FOP we conducted a small observational study comparing the proteomic profiles of EV cargo, derived from pooled plasma of four patient groups: FOP patient (N = 1) during active disease phase (flare-up), FOP patients during remission (N = 2), patients after long bone fracture (N = 20) and healthy controls (N = 10). After isolation of EVs – their protein cargo was determined using liquid chromatography / mass spectrometry, after which a functional gene enrichment analysis was performed. Our results show a sizeable difference of the proteomics profiles in which EVs from the bone fracture group show significant activity of integrin interactions, Wnt, VEGF, IGF-1 and PDGF pathways; conversely, FOP patients' EVs indicate that HO occurs via processes of innate immunity and the Ephrin B signaling pathway. We hypothesize that the Ephrin B signaling (expressed in EVs) contributes to HO by aiding in mesenchymal stem cell recruitment and osteogenic differentiation, as well as by contributing to the inflammatory response, including macrophage chemotaxis and activation. This is, to our knowledge, the first published analysis of EV protein cargo in FOP.

•

Proteomics-based analysis of extracellular vesicles’ protein cargo in FOP patients, bone fracture healing and controls.

•

Marked differences in signaling pathways expressed in extracellular vesicles in FOP vs. patients with bone fractures.

•

Ephrin B signaling pathway expressed in extracellular vesicles identified as a likely cogwheel in heterotopic ossification.

Recent Advances in RNA Therapy and Its Carriers to Treat the Single-Gene Neurological Disorders

The development of new sequencing technologies in the post-genomic era has accelerated the identification of causative mutations of several single gene disorders. Advances in cell and animal models provide insights into the underlining pathogenesis, which facilitates the development and maturation of new treatment strategies. The progress in biochemistry and molecular biology has established a new class of therapeutics—the short RNAs and expressible long RNAs. The sequences of therapeutic RNAs can be optimized to enhance their stability and translatability with reduced immunogenicity. The chemically-modified RNAs can also increase their stability during intracellular trafficking. In addition, the development of safe and high efficiency carriers that preserves the integrity of therapeutic RNA molecules also accelerates the transition of RNA therapeutics into the clinic. For example, for diseases that are caused by genetic defects in a specific protein, an effective approach termed “protein replacement therapy” can provide treatment through the delivery of modified translatable mRNAs. Short interference RNAs can also be used to treat diseases caused by gain of function mutations or restore the splicing aberration defects. Here we review the applications of newly developed RNA-based therapeutics and its delivery and discuss the clinical evidence supporting the potential of RNA-based therapy in single-gene neurological disorders.

Extracellular vesicles of Fusobacterium nucleatum compromise intestinal barrier through targeting RIPK1-mediated cell death pathway

Microbial factors that mediate microbes-host interaction in ulcerative colitis (UC), a chronic disease seriously affecting human health, are not fully known. The emerging oncobacterium Fusobacterium nucleatum (Fn) secretes extracellular vesicles carrying several types of harmful molecules in the intestine which can alter microbes-host interaction, especially the epithelial homeostasis in UC. However, the mechanism is not yet clear. Previously, we isolated EVs by the ultracentrifugation of Fn culture media and characterized them as the potent inducer of pro-inflammatory cytokines. Here, we examined the mechanism in detail. We found that in macrophage/Caco-2 co-cultures, FnEVs significantly promoted epithelial barrier loss and oxidative stress damage, which are related to epithelial necroptosis caused by the activation of receptor-interacting protein kinase 1 (RIPK1) and receptor-interacting protein kinase 3 (RIPK3). Furthermore, FnEVs promoted the migration of RIPK1 and RIPK3 into necrosome in Caco2 cells. Notably, these effects were reversed by TNF-α neutralizing antibody or Necrostatin-1 (Nec-1), a RIPK1 inhibitor. This suggested that FADD-RIPK1-caspase-3 signaling is involved in the process. Moreover, the observed effects were verified in the murine colitis model treated with FnEVs or by adoptive transfer of FnEVs-trained macrophages. In conclusion, we propose that RIPK1-mediated epithelial cell death promotes FnEVs-induced gut barrier disruption in UC and the findings can be used as the basis to further investigate this disease.

Methodologies to Isolate and Purify Clinical Grade Extracellular Vesicles for Medical Applications

The use of extracellular vesicles (EV) in nano drug delivery has been demonstrated in many previous studies. In this study, we discuss the sources of extracellular vesicles, including plant, salivary and urinary sources which are easily available but less sought after compared with blood and tissue. Extensive research in the past decade has established that the breadth of EV applications is wide. However, the efforts on standardizing the isolation and purification methods have not brought us to a point that can match the potential of extracellular vesicles for clinical use. The standardization can open doors for many researchers and clinicians alike to experiment with the proposed clinical uses with lesser concerns regarding untraceable side effects. It can make it easier to identify the mechanism of therapeutic benefits and to track the mechanism of any unforeseen effects observed.

Mesenchymal Stromal/Stem Cells-Derived Exosomes as an Antimicrobial Weapon for Orodental Infections

The oral cavity as the second most various microbial community in the body contains a broad spectrum of microorganisms which are known as the oral microbiome. The oral microbiome includes different types of microbes such as bacteria, fungi, viruses, and protozoa. Numerous factors can affect the equilibrium of the oral microbiome community which can eventually lead to orodental infectious diseases. Periodontitis, dental caries, oral leukoplakia, oral squamous cell carcinoma are some multifactorial infectious diseases in the oral cavity. In defending against infection, the immune system has an essential role. Depending on the speed and specificity of the reaction, immunity is divided into two different types which are named the innate and the adaptive responses but also there is much interaction between them. In these responses, different types of immune cells are present and recent evidence demonstrates that these cell types both within the innate and adaptive immune systems are capable of secreting some extracellular vesicles named exosomes which are involved in the response to infection. Exosomes are 30-150 nm lipid bilayer vesicles that consist of variant molecules, including proteins, lipids, and genetic materials and they have been associated with cell-to-cell communications. However, some kinds of exosomes can be effective on the pathogenicity of various microorganisms and promoting infections, and some other ones have antimicrobial and anti-infective functions in microbial diseases. These discrepancies in performance are due to the origin of the exosome. Exosomes can modulate the innate and specific immune responses of host cells by participating in antigen presentation for activation of immune cells and stimulating the release of inflammatory factors and the expression of immune molecules. Also, mesenchymal stromal/stem cells (MSCs)-derived exosomes participate in immunomodulation by different mechanisms. Ease of expansion and immunotherapeutic capabilities of MSCs, develop their applications in hundreds of clinical trials. Recently, it has been shown that cell-free therapies, like exosome therapies, by having more advantages than previous treatment methods are emerging as a promising strategy for the treatment of several diseases, in particular inflammatory conditions. In orodental infectious disease, exosomes can also play an important role by modulating immunoinflammatory responses. Therefore, MSCs-derived exosomes may have potential therapeutic effects to be a choice for controlling and treatment of orodental infectious diseases.

Recent progress of macrophage vesicle-based drug delivery systems

Nanoparticle drug delivery systems (NDDSs) are promising platforms for efficient delivery of drugs. In the past decades, many nanomedicines have received clinical approval and completed translation. With the rapid advance of nanobiotechnology, natural vectors are emerging as novel strategies to carry and delivery nanoparticles and drugs for biomedical applications. Among diverse types of cells, macrophage is of great interest for their essential roles in inflammatory and immune responses. Macrophage-derived vesicles (MVs), including exosomes, microvesicles, and those from reconstructed membranes, may inherit the chemotactic migration ability and high biocompatibility. The unique properties of MVs make them competing candidates as novel drug delivery systems for precision nanomedicine. In this review, the advantages and disadvantages of existing NDDSs and MV-based drug delivery systems (MVDDSs) were compared. Then, we summarized the potential applications of MVDDSs and discuss future perspectives. The development of MVDDS may provide avenues for the treatment of diseases involving an inflammatory process.

Nature-inspired dynamic gene-loaded nanoassemblies for the treatment of brain diseases

Gene therapy has great potential to treat brain diseases. However, genetic drugs need to overcome a cascade of barriers for their full potential. The conventional delivery systems often struggle to meet expectations. Natural biological particles that are highly optimized for specific functions in body, can inspire optimization of dynamic gene-loaded nanoassemblies (DGN). The DGN refer to gene loaded nanoassemblies whose functions and structures are changeable in response to the biological microenvironments or can dynamically interact with tissues or cells. The nature-inspired DGN can meet the needs in brain diseases treatment, including i) Non-elimination in blood (N), ii) Across the blood-brain barrier (A), iii) Targeting cells (T), iv) Efficient uptake (U), v) Controllable release (R), vi) Eyeable (E)-abbreviated as the "NATURE". In this Review, from nature to "NATURE", we mainly summarize the specific application of nature-inspired DGN in the "NATURE" cascade process. Furthermore, the Review provides an outlook for this field.

The comprehensive analysis based study of perfluorinated compounds-Environmental explanation of bladder cancer progression

Perfluorinated compounds are emerging organic pollutants widely used in building materials, textiles, and electric equipment. Herein, silico analysis was conducted using bioinformatics approach to assess the potential relationship between bladder cancer and perfluorinated compounds. Transcriptome profiles and data of perfluorinated compounds were obtained from The Cancer Genome Atlas (TCGA) and the Genotype-Tissue Expression and Comparative Toxicogenomics databases. Gene Ontology (GO9 and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses showed that interactive genes were mainly enriched in bladder cancer (BC). Transcriptome profiles were used to verify the expression of m6A-related genes at the mRNA and protein levels. Most m6A-related genes predicted BC prognosis. Survival analysis and ROC curves demonstrated that the expression levels of m6A-related genes were associated with BC prognosis. Perfluorooctanoic acid (PFOA) significantly increased the cell proliferation ability and promoted cell invasion capacity. In addition, PFOA significantly increased the cell viability and cell invasion capacity of T24 and BIU-87 cell lines compared with the control group. Taken together, these results show that perfluorinated compounds could promote BC progression. DATA AVAILABILITY: Data and materials are available within the manuscript.

OUP accepted manuscript

To date, no reliable clinically applicable biomarker has been established for Parkinson's disease. Our results indicate that a long anticipated blood test for Parkinson's disease may be realized. Following the isolation of neuron-derived extracellular vesicles of Parkinson's disease patients and non-Parkinson's disease individuals, immunoblot analyses were performed to detect extracellular vesicle-derived α-synuclein. Pathological α-synuclein forms derived from neuronal extracellular vesicles could be detected under native conditions and were significantly increased in all individuals with Parkinson's disease and clearly distinguished disease from the non-disease state. By performing an α-synuclein seeding assay these soluble conformers could be amplified and seeding of pathological protein folding was demonstrated. Amplified α-synuclein conformers exhibited β-sheet-rich structures and a fibrillary appearance. Our study demonstrates that the detection of pathological α-synuclein conformers from neuron-derived extracellular vesicles from blood plasma samples has the potential to evolve into a blood-biomarker of Parkinson's disease that is still lacking so far. Moreover, the distribution of seeding-competent α-synuclein within blood exosomes sheds a new light of pathological disease mechanisms in neurodegenerative disorders.

Fine Particulate Matter Induces Childhood Asthma Attacks via Extracellular Vesicle-Packaged Let-7i-5p-Mediated Modulation of the MAPK Signaling Pathway

Fine particulate matter less than 2.5 µm in diameter (PM2.5 ) is a major risk factor for acute asthma attacks in children. However, the biological mechanism underlying this association remains unclear. In the present study, PM2.5 -treated HBE cells-secreted extracellular vesicles (PM2.5 -EVs) caused cytotoxicity in "horizontal" HBE cells and increased the contractility of "longitudinal" sensitive human bronchial smooth muscle cells (HBSMCs). RNA sequencing showed that let-7i-5p is significantly overexpressed in PM2.5 -EVs and asthmatic plasma; additionally, its level is correlated with PM2.5 exposure in children with asthma. The combination of EV-packaged let-7i-5p and the traditional clinical biomarker IgE exhibits the best diagnostic performance (area under the curve [AUC] = 0.855, 95% CI = 0.786-0.923). Mechanistically, let-7i-5p is packaged into PM2.5 -EVs by interacting with ELAVL1 and internalized by both "horizontal" recipient HBE cells and "longitudinal" recipient-sensitive HBSMCs, with subsequent activation of the MAPK signaling pathway via suppression of its target DUSP1. Furthermore, an injection of EV-packaged let-7i-5p into PM2.5 -treated juvenile mice aggravated asthma symptoms. This comprehensive study deciphered the remodeling of the extracellular environment mediated by the secretion of let-7i-5p-enriched EVs during PM2.5 -induced asthma attacks and identified plasma EV-packaged let-7i-5p as a novel predictor of childhood asthma.

Therapeutic Applications of Extracellular Vesicles for Myocardial Repair

Cardiovascular disease is the leading cause of human death worldwide. Drug thrombolysis, percutaneous coronary intervention, coronary artery bypass grafting and other methods are used to restore blood perfusion for coronary artery stenosis and blockage. The treatments listed prolong lifespan, however, rate of mortality ultimately remains the same. This is due to the irreversible damage sustained by myocardium, in which millions of heart cells are lost during myocardial infarction. The lack of pragmatic methods of myocardial restoration remains the greatest challenge for effective treatment. Exosomes are small extracellular vesicles (EVs) actively secreted by all cell types that act as effective transmitters of biological signals which contribute to both reparative and pathological processes within the heart. Exosomes have become the focus of many researchers as a novel drug delivery system due to the advantages of low toxicity, little immunogenicity and good permeability. In this review, we discuss the progress and challenges of EVs in myocardial repair, and review the recent development of extracellular vesicle-loading systems based on their unique nanostructures and physiological functions, as well as the application of engineering modifications in the diagnosis and treatment of myocardial repair.

The Extracellular Matrix Enriched With Exosomes for the Treatment on Pulmonary Fibrosis in Mice

Pulmonary fibrosis (PF) is a severe respiratory disease caused by lung microenvironment changes. TGF-β/Smad3 signaling pathway plays a critical role in the fibrotic process. MicroRNA-29 (miR-29) has proved to alleviate the occurrence of PF by downregulating TGF-β/Smad3 signaling pathway. The miRNA application encounters obstacles due to its low stability in body and no targeting to lesions. Exosomes can be used for therapeutic delivery of miRNA due to their favorable delivery properties. However, low efficiency of separation and production impedes the therapeutic application of exosomes. In this study, we developed a liquid natural extracellular matrix (ECM) enriched with miR-29-loaded exosomes for PF treatment. The collagen-binding domain (CBD)-fused Lamp2b (CBD-Lamp2b) and miR-29 were overexpressed in human foreskin fibroblast (HFF) host cells for the entrapment of miR-29-loaded exosomes in ECM of the cells. The repeated freeze-thaw method was performed to prepare the liquid ECM enriched with exosomes without destroying the exosomal membrane. In summary, this study developed a novel functional ECM biomaterial for therapy of PF, and also provided a promising gene therapy platform for different diseases by treatment with liquid ECM that is, enriched with exosomes loaded with different functional miRNAs.