An overview of current knowledge in biological functions and potential theragnostic applications of exosomes

The Main Mechanisms of Mesenchymal Stem Cell-Based Treatments against COVID-19

BACKGROUND

Coronavirus disease 2019 (COVID-19) has a clinical manifestation of hypoxic respiratory failure and acute respiratory distress syndrome. However, COVID-19 still lacks of effective clinical treatments so far. As a promising potential treatment against COVID-19, stem cell therapy raised recently and had attracted much attention. Here we review the mechanisms of mesenchymal stem cell-based treatments against COVID-19, and provide potential cues for the effective control of COVID-19 in the future.

METHODS

Literature is obtained from databases PubMed and Web of Science. Key words were chosen for COVID- 19, acute respiratory syndrome coronavirus 2, mesenchymal stem cells, stem cell therapy, and therapeutic mechanism. Then we summarize and critically analyze the relevant articles retrieved.

RESULTS

Mesenchymal stem cell therapy is a potential effective treatment against COVID-19. Its therapeutic efficacy is mainly reflected in reducing severe pulmonary inflammation, reducing lung injury, improving pulmonary function, protecting and repairing lung tissue of the patients. Possible therapeutic mechanisms might include immunoregulation, anti-inflammatory effect, tissue regeneration, anti-apoptosis effect, antiviral, and antibacterial effect, MSC - EVs, and so on.

CONCLUSION

Mesenchymal stem cells can effectively treat COVID-19 through immunoregulation, anti-inflammatory, tissue regeneration, anti-apoptosis, anti-virus and antibacterial, MSC - EVs, and other ways. Systematically elucidating the mechanisms of mesenchymal stem cell-based treatments for COVID-19 will provide novel insights into the follow-up research and development of new therapeutic strategies in next step.

Delineating Bovine Milk Derived Microvesicles from Exosomes Using Proteomics

In the work presented herein, a simple serial-pelleting purification strategy combined with a mass spectrometry-based proteomics analysis was developed as a means of discerning differences in extracellular vesicle (EV) populations found in bovine milk samples. A sequence of ultracentrifugation speeds was used to generate changes in the abundances of EV populations, allowing for the identification of associated proteins. A metric was developed to determine the relative abundances of proteins in large EVs (>200 nm) and small EVs (<200 nm). Of the 476 proteins consistently found in this study, 340 are associated with vesicular components. Of these, 156 were heavily enriched in large EVs, 155 shared between large and small EVs, and 29 heavily enriched in small EVs. Additionally, out of 68 proteins annotated as exosome proteins, 32 were enriched in large EVs, 27 shared between large and small EVs, 5 enriched in small EVs, and 7 were found to be nonvesicular contaminant proteins. The top correlated proteins in the small EV group were predominantly membrane-bound proteins, whereas the top correlated proteins in the large EV group were mostly cytosolic enzymes for molecular processing. This method provides a means of assessing the origins of vesicle components and provides new potential marker proteins within discrete vesicle populations.

Diagnostic value of exosomal noncoding RNA in lung cancer: a meta-analysis

Background

Lung cancer is one of the most dangerous cancers in the world. Most lung cancer patients are diagnosed in the middle and later stages, which can lead to poor survival rates. The development of lung cancer is often accompanied by abnormal expression of exosomal non-coding RNAs, which means that they have the potential to serve as noninvasive novel molecular markers for lung cancer diagnosis.

Methods

For this study, we conducted a comprehensive literature search in PubMed, Web of science, Science direct, Embase, Cochrane, and Medline databases, and by reviewing published literature, The diagnostic capacity of exosomal microRNAs (miRNAs), long-chain non-coding RNAs (lncRNAs), and circular RNAs (circRNAs) for lung cancer was evaluated. Functional enrichment analysis of miRNA target genes was performed.

Results

The study included 41 papers, a total of 68 studies. More than 60 miRNAs, 9 lncRNAs and 14 circRNAs were involved. The combined sensitivity and specificity were 0.83(95%CI, 0.80~0.86) and 0.83(95% CI,0.79~0.87); 0.71(95% CI,0.68~0.74) and 0.79(95%CI, 0.75~0.82); 0.79(95%CI,0.67~0.87) and 0.81(95%CI,0.74~0.86), and constructed overall subject operating characteristic curves with the summarized area under the curve values of 0.90, 0.82, and 0.86.

Conclusion

Our study shows that exosomes miRNAs, lncRNAs and circRNAs are effective in the diagnosis of lung cancer, providing evidence for studies related to novel lung cancer diagnostic markers.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42023457087.

Plant exosome-like nanovesicles derived from sesame leaves as carriers for luteolin delivery: Molecular docking, stability and bioactivity

The growing recognition of luteolin (Lu) as a vital functional component is attributed to its notable bioactive properties. However, the effective use of Lu is hindered by its inherent limitations related to water solubility, stability, and bioavailability. Here, we aim to develop sesame leaves-derived exosome-like nanovesicles (Exo) for Lu delivery (Exo@Lu) as vehicles. The encapsulation mechanism, solubility, stability, and bioactivity of Exo@Lu were thoroughly evaluated. Exo enriched abundant lipids, proteins, and phenolic compounds with an encapsulation efficiency of ∼ 91.9 % and a loading capacity of ∼ 20.5 % for Lu. The primary binding forces responsible for the encapsulation were hydrogen bonds and van der Waals forces. After encapsulation, the water solubility and stability of Lu were significantly improved under various conditions, including thermal, light, storage, ionic strength, and pH. Exo@Lu maintained structural integrity during simulated digestion, enhancing bioaccessibility and efficacy in mitigating oxidative stress and inflammatory response compared to Exo and free Lu.

Communication between nonalcoholic fatty liver disease and atherosclerosis: Focusing on exosomes

Nonalcoholic fatty liver disease (NAFLD) is the most prevalent chronic hepatic disorder on a global scale. Atherosclerosis (AS), a leading cause of cardiovascular diseases, stands as the primary contributor to mortality among patients diagnosed with NAFLD. However, the precise etiology by which NAFLD causes AS remains unclear. Exosomes are nanoscale extracellular vesicles secreted by cells, and are considered to participate in complex biological processes by promoting cell-to-cell and organ-to-organ communications. As vesicles containing protein, mRNA, non-coding RNA and other bioactive molecules, exosomes can participate in the development of NAFLD and AS respectively. Recently, studies have shown that NAFLD can also promote the development of AS via secreting exosomes. Herein, we summarized the recent advantages of exosomes in the pathogenesis of NAFLD and AS, and highlighted the role of exosomes in mediating the information exchange between NAFLD and AS. Further, we discussed how exosomes play a prominent role in enabling information exchange among diverse organs, delving into a novel avenue for investigating the link between diseases and their associated complications. The future directions and emerging challenges are also listed regarding the exosome-based therapeutic strategies for AS under NAFLD conditions.

Prospects of plant-derived exosome-like nanocarriers in oncology and tissue engineering

Almost all cell types, either in vivo or in vitro, create extracellular vesicles (EVs). Among them are exosomes (EXOs), i.e., tiny nanovesicles containing a lipid bilayer, proteins, and RNAs that are actively involved in cellular communication, indicating that they may be exploited as both diagnostics and therapeutics for conditions like cancer. These nanoparticles can also be used as nanocarriers in many types of research to carry agents such as drugs. Plant-derived exosome-like nanoparticles (PENs) are currently under investigation as a substitute for EXOs formed from mammalian cells, allowing researchers to get beyond the technical constraints of mammalian vesicles. Because of their physiological, chemical, and biological properties, PENs have a lot of promise for use as nanocarriers in drug delivery systems that can deliver various dosages, especially when it comes to large-scale repeatability. The present study has looked at the origins and isolation techniques of PENs, their anticancer properties, their usage as nanocarriers in the treatment of different illnesses, and their antioxidant properties. These nanoparticles can aid in the achievement of therapeutic objectives, as they have benign, non-immunogenic side effects and can pass biological barriers. Time-consuming and perhaps damaging PEN separation techniques is used. For the current PEN separation techniques to be used in commercial and therapeutic settings, they must be altered. In this regard, the concurrent application of biological sciences can be beneficial for improving PEN separation techniques. PENs' innate metabolic properties provide them a great deal of promise for application in drug delivery systems. However, there could be a risk to both the loaded medications and the intrinsic bioactive components if these particles are heavily armed with drugs. Therefore, to prevent these side effects, more studies are needed to devise sophisticated drug-loading procedures and to learn more about the physiology of PENs.

Exosomal miR-146a-5p derived from human umbilical cord mesenchymal stem cells can alleviate antiphospholipid antibody-induced trophoblast injury and placental dysfunction by regulating the TRAF6/NF-κB axis

Exosomes originating from human umbilical cord mesenchymal stem cells (hucMSC-exos) have become a novel strategy for treating various diseases owing to their ability to regulate intercellular signal communication. However, the potential of hucMSC-exos to improve placental injury in obstetric antiphospholipid syndrome and its underlying mechanism remain unclear. Our objective was to explore the potential application of hucMSC-exos in the treatment of obstetric antiphospholipid syndrome and elucidate its underlying mechanism. In our study, hucMSC-exos ameliorated the functional impairment of trophoblasts caused by antiphospholipid antibodies in vitro and attenuated placental dysfunction in mice with obstetric antiphospholipid syndrome by delivering miR-146a-5p. Exosomal miR-146a-5p suppressed the expression of tumor necrosis factor receptor-associated factor 6 (TRAF6) and inhibited the activation of NF-κB signaling, leading to the down-regulation of IL-1β and IL-18 to rescue inflammation and modulation of Cleaved-CASP3, BAX, and BCL2 to inhibit apoptosis in HTR8/SVneo cells and mice placenta. This study identified the potential molecular basis of how hucMSC-exos improved antiphospholipid antibody-induced placental injury and highlighted the functional importance of the miR-146a-5p/TRAF6 axis in the progression of obstetric antiphospholipid syndrome. More importantly, this study provided a fresh outlook on the promising use of hucMSC-exos as a novel and effective treatment approach in obstetric antiphospholipid syndrome.

P65 mediated UBR4 in exosomes derived from menstrual blood stromal cells to reduce endometrial fibrosis by regulating YAP Ubiquitination

BACKGROUND

Intrauterine adhesion (IUA) is a recurrent and refractory reproductive dysfunction disorder for which menstrual blood-derived stromal cells (MenSCs) might be a promising intervention. We reported that administration of MenSCs-derived exosomes (MenSCs-EXO) could achieve similar therapeutic effects to MenSCs transplantation, including alleviating endometrial fibrosis and improving fertility in IUA rats. The mass spectrometry sequencing result suggested that UBR4, a member of the proteasome family, was abundantly enriched in MenSCs-EXO. This study aimed to investigate the key role of UBR4 in MenSCs-EXO for the treatment of IUA and the specific molecular mechanism.

RESULTS

UBR4 was lowly expressed in the endometrial stromal cells (EndoSCs) of IUA patients. MenSCs-EXO treatment could restore the morphology of IUA endometrium, reduce the extent of fibrosis, and promote endometrial and vascular proliferation. Knockdown of UBR4 in MenSCs did not affect the characteristics of exosomes but attenuated the therapeutic effect of exosomes. UBR4 in MenSCs-EXO could alleviate endometrial fibrosis by boosting YAP ubiquitination degradation and promoting YAP nuclear-cytoplasmic translocation. Moreover, P65 could bind to the UBR4 promoter region to transcriptionally promote the expression level of UBR4 in MenSCs.

CONCLUSION

Our study clarified that MenSCs-EXO ameliorated endometrial fibrosis in IUA primarily by affecting YAP activity mediated through UBR4, while inflammatory signaling P65 may affect UBR4 expression in MenSCs to enhance MenSCs-EXO therapeutic effects. This revealed a novel mechanism for the treatment of IUA with MenSCs-EXO, proposing a potential option for the clinical treatment of endometrial injury.

Exosomes obtained from adipose mesenchymal stem cells prevent ischemia-reperfusion injury after torsion-detorsion in rat testes

PURPOSE

To investigate the effect of exosomes obtained from adipose-derived mesenchymal stem cells (AD-MSCs) on testicular ischemia-reperfusion (I/R) injury.

METHODS

AD-MSCs from rat adipose tissue were cultured. Characterization of cells was evaluated with CD44, CD90, CD34 and CD45 antibodies. Exosomes from AD-MSCs were obtained with the miRCURY exosome isolation kit. 21 rats were divided into 3 groups. The I/R model was created as 720° torsion for 4 h and reperfusion for 4 h. In the Sham group (SG), only scrotal incision was made. 100 µl of medium in the torsion-control group (T-CG) and 100 µl of exosome in the treatment group (TG) were injected into the testicular parenchyma after detorsion. Johnsen scores of testicles were determined. Apoptosis was evaluated by the TUNEL method.

RESULTS

It was observed that the seminiferous tubule structures were partially disrupted in T-CG, but normal in SG and TG. Johnsen scores in SG, T-CG, and TG were 8.64 ± 0.39, 7.71 ± 0.37, and 8.57 ± 0.39, respectively. Apoptotic cell distribution was 11.28 ± 5.25%, 60.58% ± 1.68% and 17.71 ± 8.34% in SG, T-CG and TG, respectively. In both parameters, the difference between SG and TG was insignificant (p > 0.05), the difference between T-CG/TG and SG/T-CG was significant (p < 0.05).

CONCLUSION

Exosomes obtained from AD-MSCs are effective in preventing testicular I/R injury. This effect appears to occur because of suppression of apoptotic activity.

Exosome-loaded scaffolds for regenerative medicine in hard tissues

Tissue engineering can be used to repair tissue by employing bioscaffolds that provide better spatial control, porosity, and a three-dimensional (3D) environment like the human body. Optimization of injectability, biocompatibility, bioactivity, and controlled drug release are also features of such scaffolds. The 3D shape of the scaffold can control cell interaction and improve cell migration, proliferation, and differentiation. Exosomes (EXOs) are nanovesicles that can regulate osteoblast activity and proliferation using a complex composition of lipids, proteins, and nucleic acids in their vesicles. Due to their excellent biocompatibility and efficient cellular internalization, EXOs have enormous potential as desirable drug/gene delivery vectors in the field of regenerative medicine. They can cross the biological barrier with minimal immunogenicity and side effects. Scaffolds that contain EXOs have been studied extensively in both basic and preclinical settings for the regeneration and repair of both hard (bone, cartilage) and soft (skin, heart, liver, kidney) tissue. Cell motility, proliferation, phenotype, and maturation can all be controlled by EXOs. The angiogenic and anti-inflammatory properties of EXOs significantly influence tissue healing. The current study focused on the use of EXO-loaded scaffolds in hard tissue regeneration.

Exosomes as biomarkers and therapeutic delivery for autoimmune diseases: Opportunities and challenges

Exosomes are spherical lipid bilayer vesicles composed of lipids, proteins and nucleic acids that deliver signaling molecules through a vesicular transport system to regulate the function and morphology of target cells, thereby involving in a variety of biological processes, such as cell apoptosis or proliferation, and cytokine production. In the past decades, there are emerging evidence that exosomes play pivotal roles in the pathological mechanisms of several autoimmune diseases (ADs), including rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), type 1 diabetes mellitus (T1DM), Sjogren's syndrome (SS), multiple sclerosis (MS), inflammatory bowel disease (IBD). systemic sclerosis (SSc), etc. Several publications have shown that exosomes are involved in the pathogenesis of ADs mainly through intercellular communication and by influencing the response of immune cells. The level of exosomes and the expression of nucleic acids can reflect the degree of disease progression and are excellent biomarkers for ADs. In addition, exosomes have the potential to be used as drug carriers thanks to their biocompatibility and stability. In this review, we briefly summarized the current researches regarding the biological functions of exosomes in ADs, and provided an insight into the potential of exosomes as biomarkers and therapeutic delivery for these diseases.

Pathways for Cardioprotection in Perspective: Focus on Remote Conditioning and Extracellular Vesicles

Despite the development of cutting-edge treatments, coronary artery disease (CAD) morbidity and mortality rates remain present at high levels. Therefore, new cardioprotective approaches are crucial to improve the health of patients. To date, experimental investigations of acute ischemia-reperfusion injury (IRI) have generally demonstrated the efficacy of local ischemic preconditioning and postconditioning cardioprotection techniques as well as of remote conditioning. However, application in clinical settings is still highly controversial and debated. Currently, remote ischemic conditioning (RIC) seems to be the most promising method for heart repair. Protective factors are released into the bloodstream, and protection can be transferred within and across species. For a long time, the cross-function and cross-transmission mechanisms of cardioprotection were largely unknown. Recently, it has been shown that small, anuclear, bilayered lipid membrane particles, known as extracellular vesicles (EVs), are the drivers of signal transduction in cardiac IRI and RIC. EVs are related to the pathophysiological processes of cardiovascular diseases (CVDs), according to compelling evidence. In this review, we will first review the current state of knowledge on myocardial IRI and cardioprotective strategies explored over the past 37 years. Second, we will briefly discuss the role of EVs in CVD and the most recent improvements on EVs as prognostic biomarkers, diagnostic, and therapeutic agents. We will discuss how EVs can be used as a new drug delivery mechanism and how they can be employed in cardiac treatment, also from a perspective of overcoming the impasse that results from neglecting confounding factors.

Exosomes and ultrasound: The future of theranostic applications

Biomaterials and pertaining formulations have been very successful in various diagnostic and therapeutic applications because of its ability to overcome pharmacological limitations. Some of them have gained significant focus in the recent decade for their theranostic properties. Exosomes can be grouped as biomaterials, since they consist of various biological micro/macromolecules and possess all the properties of a stable biomaterial with size in nano range. Significant research has gone into isolation and exploitation of exosomes as potential theranostic agent. However, the limitations in terms of yield, efficacy, and target specificity are continuously being addressed. On the other hand, several nano/microformulations are responsive to physical or chemical alterations and were successfully stimulated by tweaking the physical characteristics of the surrounding environment they are in. Some of them are termed as photodynamic, sonodynamic or thermodynamic therapeutic systems. In this regard, ultrasound and acoustic systems were extensively studied for its ability towards altering the properties of the systems to which they were applied on. In this review, we have detailed about the diagnostic and therapeutic applications of exosomes and ultrasound separately, consisting of their conventional applications, drawbacks, and developments for addressing the challenges. The information were categorized into various sections that provide complete overview of the isolation strategies and theranostic applications of exosomes in various diseases. Then the ultrasound-based disease diagnosis and therapy were elaborated, with special interest towards the use of ultrasound in enhancing the efficacy of nanomedicines and nanodrug delivery systems, Finally, we discussed about the ability of ultrasound in enhancing the diagnostic and therapeutic properties of exosomes, which could be the future of theranostics.

Critical roles of cytokine storm and bacterial infection in patients with COVID-19: therapeutic potential of mesenchymal stem cells

The severe acute respiratory syndrome coronavirus 2 has been a shocking disaster for healthcare systems worldwide since December 2019. This virus can affect all systems of the body and its symptoms vary from a simple upper respiratory infection to fatal complications including end-organ damage. On the other hand, the normal immune system plays a pivotal role in the recovery of infectious diseases such as COVID-19. However, occasionally, exaggerated immune system inflammation and an excessive synthesis of cytokines, known as a "cytokine storm," can deteriorate the patient's clinical condition. Secondary bacterial co-infection is another problem in COVID-19 which affects the prognosis of patients. Although there are a few studies about this complication, they suggest not using antibiotics commonly, especially broad-spectrum ones. During this pandemic, various approaches and therapeutics were introduced for treating COVID-19 patients. However, available treatments are not helpful enough, especially for complicated cases. Hence, in this era, cell therapy and regenerative medicine will create new opportunities. Therefore, the therapeutic benefits of mesenchymal stem cells, especially their antimicrobial activity, will help us understand how to treat COVID-19. Herein, mesenchymal stem cells may stop the immune system from becoming overactive in COVID-19 patients. On the other side, the stem cells' capacity for repair could encourage natural healing processes.

MicroRNA Modulation during Orthodontic Tooth Movement: A Promising Strategy for Novel Diagnostic and Personalized Therapeutic Interventions

The Orthodontic Tooth Movement (OTM) is allowed through a mediated cell/tissue mechanism performed by applying a force or a pair of forces on the dental elements, and the tooth movement is a fundamental requirement during any orthodontic treatment. In this regard, it has been widely shown that each orthodontic treatment has a minimum duration required concerning numerous factors (age, patient compliance, type of technique used, etc.). In this regard, the aim of the following revision of the literature is to give readers a global vision of principal microRNAs (miRNAs) that are most frequently associated with OTM and their possible roles. Previously published studies of the last 15 years have been considered in the PubMed search using "OTM" and "miRNA" keywords for the present review article. In vitro and in vivo studies and clinical trials were mainly explored. Correlation between OTM and modulation of several miRNAs acting through post-transcriptional regulation on target genes was observed in the majority of previous studied. The expression analysis of miRNAs in biological samples, such as gingival crevicular fluid (GCF), can be considered a useful tool for novel diagnostic and/or prognostic approaches and for new personalized orthodontic treatments able to achieve a better clinical response rate. Although only a few studies have been published, the data obtained until now encourage further investigation of the role of miRNA modulation during orthodontic treatment. The aim of this study is to update the insights into the role and impact of principal micro-RNAs (miRNAs) that are most frequently associated during OTM.

The protective effects of miR-210 modified endothelial progenitor cells released exosomes in hypoxia/reoxygenation injured neurons

We have previously demonstrated that endothelial progenitor cells (EPCs) provide beneficial effects on ischemic stroke by reducing oxidative stress, which could be through EPCs-released exosomes (EPC-EXs). EXs are emerging as a bioagent for mediating cell-cell communications via their carried microRNAs (miR). miR-210 is shown to provide a neuroprotection effect against ischemic stroke. Here, we aimed to determine whether the combination of EPC-EXs and miR-210 would provide an enhanced protective effect on neurons. The hypoxia and reoxygenation (H/R) model were applied to neurons to mimic the ischemic injury of neurons. EPCs were transfected with miR-210 mimic to elevate the level of miR-210 in cells and EPC-EXs (miR210-EPC-EXs). For functional studies, EPC-EXs were co-incubated with H/R-injured neurons, then the cell viability and reactive oxygen species (ROS) production were determined. The results showed 1) H/R induced apoptosis and ROS overproduction in neurons; 2) miR-210 mimic increased the level of miR-210 in both EPCs and EPC-EXs; 3) EPCs cultured in serum-free medium released more exosomes in comparison with cells grown in complete growth media, suggesting serum starving induce the release of EXs; 4) After transfection, EPCs grown in complete media had almost 50 times higher miR-210 level than EPCs had in serum-free media, while the EPCs-EXs isolated from the complete media has lower miR-210 expression than from the serum-free media in a time-dependent manner, suggesting the transfer of miR-210 through EXs; 5) After co-incubation, EPC-EXs and miR210-EPC-EXs were uptaken by neurons, and the miR-210 level in neurons was elevated by miR210-EPC-EXs; 6) miR210-EPC-EXs were more effective in promoting cell viability and decreasing apoptosis and ROS production than EPC-EXs. The present study demonstrated that EPCs-carried miR-210 could be released and transferred to neurons in a time-dependent manner and that miR-210 loading can enhance the protective effects of EPC-EXs on H/R-induced neuron apoptosis, oxidative stress, and decreased viability.

Small extracellular vesicles as key players in cancer development caused by human oncogenic viruses

Background

Exosomes are the smallest group of extracellular vesicles in size from 30 to 150 nm, surrounded by a lipid bilayer membrane, and originate from multivesicular bodies secreted by different types of cells, such as virus-infected cells. The critical role of exosomes is information transfer among cells, representing a unique way for intercellular communication via a load of many kinds of molecules, including various signaling proteins and nucleic acids. In this review, we aimed to comprehensively investigate the role of exosomes in promoting human oncogenic viruses-associated cancers.

Methods

Our search was conducted for published researches between 2000 and 2022 by using several international databases includeing Scopus, PubMed, and Web of Science as well as Google scholar. We also reviewed additional evidence from relevant published articles.

Results

It has been shown that exosomes can create the conditions for viral spread in viral infections. Exosome secretion in a human tumor virus can switch on the cell signaling pathways by transferring exosome-encapsulated molecules, including viral oncoproteins, signal transduction molecules, and virus-encoded miRNAs, into various cells.

Conclusion

Given the role of exosomes in viruses-associated cancers, they can also be considered as molecular targets in diagnosis and treatment.

Mesenchymal Stem Cells and MSCs-Derived Extracellular Vesicles in Infectious Diseases: From Basic Research to Clinical Practice

Mesenchymal stem cells (MSCs) are attractive in various fields of regenerative medicine due to their therapeutic potential and complex unique properties. Basic stem cell research and the global COVID-19 pandemic have given impetus to the development of cell therapy for infectious diseases. The aim of this review was to systematize scientific data on the applications of mesenchymal stem cells (MSCs) and MSC-derived extracellular vesicles (MSC-EVs) in the combined treatment of infectious diseases. Application of MSCs and MSC-EVs in the treatment of infectious diseases has immunomodulatory, anti-inflammatory, and antibacterial effects, and also promotes the restoration of the epithelium and stimulates tissue regeneration. The use of MSC-EVs is a promising cell-free treatment strategy that allows solving the problems associated with the safety of cell therapy and increasing its effectiveness. In this review, experimental data and clinical trials based on MSCs and MSC-EVs for the treatment of infectious diseases are presented. MSCs and MSC-EVs can be a promising tool for the treatment of various infectious diseases, particularly in combination with antiviral drugs. Employment of MSC-derived EVs represents a more promising strategy for cell-free treatment, demonstrating a high therapeutic potential in preclinical studies.

The role of milk-derived exosomes in the treatment of diseases

Exosomes (EXOs) are natural nanoparticles of endosome origin that are secreted by a variety of cells in the body. Exosomes have been found in bio-fluids such as urine, saliva, amniotic fluid, and ascites, among others. Milk is the only commercially available biological liquid containing EXOs. Proof that exosomes are essential for cell-to-cell communication is increasingly being reported. Studies have shown that they migrate from the cell of origin to various bioactive substances, including membrane receptors, proteins, mRNAs, microRNAs, and organelles, or they can stimulate target cells directly through interactions with receptors. Because of the presence of specific proteins, lipids, and RNAs, exosomes act in physiological and pathological conditions in vivo. Other salient features of EXOs include their long half-life in the body, no tumorigenesis, low immune response, good biocompatibility, ability to target cells through their surface biomarkers, and capacity to carry macromolecules. EXOs have been introduced to the scientific community as important, efficient, and attractive nanoparticles. They can be extracted from different sources and have the same characteristics as their parents. EXOs present in milk can be separated by size exclusion chromatography, density gradient centrifugation, or (ultra) centrifugation; however, the complex composition of milk that includes casein micelles and milk fat globules makes it necessary to take additional issues into consideration when employing the mentioned techniques with milk. As a rich source of EXOs, milk has unique properties that, in addition to its role as a carrier, promotes its use in treating diseases such as digestive problems, skin ulcers, and cancer, Moreover, EXOs derived from camel milk are reported to reduce the risk of oxidative stress and cancer. Milk-derived exosomes (MDEs) from yak milk improves gastrointestinal tract (GIT) development under hypoxic conditions. Furthermore, yak-MDEs have been suggested to be the best treatment for intestinal epithelial cells (IEC-6 cell line). Because of their availability as well as the non-invasiveness and cost-effectiveness of their preparation, isolates from mammals milk can be excellent resources for studies related to EXOs. These features also make it possible to exploit MDEs in clinical trials. The current study aimed to investigate the therapeutic applications of EXOs isolated from various milk sources.

microRNAs in Subarachnoid Hemorrhage (Review of Literature)

Recently, many studies have shown that microRNAs (miRNAs) in extracellular bioliquids are strongly associated with subarachnoid hemorrhage (SAH) and its complications. The article presents issues related to the occurrence of subarachnoid hemorrhage (epidemiology, symptoms, differential diagnosis, examination, and treatment of the patient) and a review of current research on the correlation between miRNAs and the complications of SAH. The potential use of miRNAs as biomarkers in the treatment of SAH is presented.

Emerging role of exosomes in the pathology of chronic obstructive pulmonary diseases; destructive and therapeutic properties

Chronic obstructive pulmonary disease (COPD) is known as the third leading cause of human death globally. Enhanced chronic inflammation and pathological remodeling are the main consequences of COPD, leading to decreased life span. Histological and molecular investigations revealed that prominent immune cell infiltration and release of several cytokines contribute to progressive chronic remodeling. Recent investigations have revealed that exosomes belonging to extracellular vesicles are involved in the pathogenesis of COPD. It has been elucidated that exosomes secreted from immune cells are eligible to carry numerous pro-inflammatory factors exacerbating the pathological conditions. Here, in this review article, we have summarized various and reliable information about the negative role of immune cell-derived exosomes in the remodeling of pulmonary tissue and airways destruction in COPD patients.

A comparative study of the effects of crab derived exosomes and doxorubicin in 2 & 3-dimensional in vivo models of breast cancer

INTRODUCTION

Using tissue engineering and modifying the tumor microenvironment, three-dimensional (3D) in vitro and in vivo cancer modeling can be performed with appropriate similarity to native. Exosomes derived from different sources have recently been used in cancer studies due to their anticancer effects. In this study, the effect of crab derived exosomes in 2 & 3-dimensional (2& 3D) in vivo models of breast cancer (BC) were investigated and compared with the doxorubicin (DOX).

METHODS

2D and 3D models of BC were induced using the chitosan/β-glycerol phosphate hydrogel (Ch/β-GP) and 1 × 10⁶ 4T1 cells in the female mice aged 6-8 weeks. 1 mg/ml exosome and 5 mg/kg DOX were injected by intratumoral (IT), intravenous (IV), and intraperitoneal (IP) methods into mice on day 9, 13, and 17 with and without hydrogel as a drug delivery system. After 21 days, the mice were sacrificed, and the tissues (lung, liver, and tumor) were removed. The weight and size of the tumor were measured. Real-time PCR assessed changes of VEGF, Bcl2, and P53 genes expression levels. Nitric oxide (NO) secretion from the cancer 3D model was evaluated by Griess assay.

RESULTS AND CONCLUSION

Based on the results, the size and weight of tumors in treated groups with exosomes and DOX were reduced significantly (P ≤ 0.001, P ≤ 0.002, P ≤ 0.02) in 2D and 3D models. Changes in VEGF, Bcl2 and P53 gene expression levels were less in the 3D model than in the 2D model. Drug delivery with hydrogel increased tumor inhibition compared to drug injection without hydrogel. Decreased NO secretion was observed in all treatment groups compared to the control group (untreated). Crab exosomes showed anti cancer effects on 2&3D models of BC. 3D model of BC showed greater drug resistance than the 2D model after treating with crab derived exosomes and DOX. 3D model of BC mimics native tumor better than 2D and can be used in cancer studies and for drug screening with greater confidence than 2D model. Also, the use of slow release drug delivery system reduced drug resistance in both models.

Isolation and Characterization of Crab Haemolymph Exosomes and Its Effects on Breast Cancer Cells (4T1)

OBJECTIVE

The use of animal or plant exosomes in cancer treatment is promising because of their easy access and low cost. Freshwater crabs are used in traditional Iranian medicine to treat cancer. This study aims to determine the anti-cancer properties of exosomes removed from freshwater crabs on a breast cancer cell line (4T1) compared to bone marrow mesenchymal stem cells (BMSCs).

MATERIALS AND METHODS

In this experimental study, crab haemolymph exosomes were isolated via the precipitation method and characterised by electron microscopy, dynamic light scattering (DLS), and Western blot analysis. The protein concentration and total antioxidant capacity of these exosomes were determined by bicinchoninic acid (BCA) and cupric reducing antioxidant capacity (CUPRAC). The 4T1 cells and BMSCs were treated with exosomes and we assessed the cell survival by the resazurin and MTT assays. The level of nitric oxide (NO) secretion from the 4T1 cells was determined after treatment with the exosomes.

RESULTS

Electron microscopy, DLS and Western blot for CD63 confirmed that the isolated exosomes were <100 nm in size and expressed CD63. The total antioxidant capacity in these exosomes was 1.003 μM/ml and the protein concentration was 650 mg/ml. Resazurin and MTT assay results showed a decrease in survival of the 4T1 cells (P≤0.001) after treatment with the exosomes compared to cell growth in the exosome-treated BMSCs.

CONCLUSION

Crab haemolymph contains protein-rich exosomes with antioxidant activities that can have anti-cancer effects on 4T1 cells. These exosomes may be proposed for breast cancer therapeutics.

Exosome-based therapies for mucosal delivery

Exosomes are membrane-bound extracellular nanovesicles secreted by most cells and found in multiple sources, including bodily fluids, plants, fruit, and bovine milk. They play an important role as mediators of intercellular communication, having a distinct ability to carry small molecules, proteins, and nucleic acids to recipient cells over large distances. Moreover, competency in crossing usually poorly permeable biological barriers has led to their promising use in diagnostics and in therapeutics, either as therapeutic entities on their own or as drug delivery vehicles, with superior stability, biocompatibility, circulation time and target specificity in comparison to conventional drug delivery systems. The aim of this review is to summarise and critically discuss the current literature on the use of exosomes in a therapeutic setting, with a particular focus on their use as drug delivery vehicles for mucosal drug delivery.

Exosomes Engineering and Their Roles as Therapy Delivery Tools, Therapeutic Targets, and Biomarkers

Exosomes are becoming increasingly important therapeutic biomaterials for use in a variety of therapeutic applications due to their unique characteristics, especially due to the ineffectiveness and cytotoxicity of some existing therapies and synthetic therapeutic nanocarriers. They are highly promising as carriers of drugs, genes, and other therapeutic agents that can be incorporated into their interior or onto their surface through various modification techniques to improve their targeting abilities. In addition, they are biocompatible, safe, and stable. The review focuses on different types of exosomes and methods of their preparation, including the incorporation of different kinds of cargo, especially for drug delivery purposes. In particular, their importance and effectiveness as delivery vehicles of various therapeutic agents for a variety of therapeutic applications, including different diseases and disorders such as cancer treatment, cardiovascular and neurodegenerative diseases, are emphasized. Administration routes of exosomes into the body are also included. A novelty in the article is the emphasis on global companies that are already successfully developing and testing such therapeutic biomaterials, with a focus on the most influential ones. Moreover, a comparison of the advantages and disadvantages of the various methods of exosome production is summarized for the first time.

Extracellular Vesicles in Skin Wound Healing

Each year, millions of individuals suffer from a non-healing wound, abnormal scarring, or injuries accompanied by an infection. For these cases, scientists are searching for new therapeutic interventions, from which one of the most promising is the use of extracellular vesicles (EVs). Naturally, EV-based signaling takes part in all four wound healing phases: hemostasis, inflammation, proliferation, and remodeling. Such an extensive involvement of EVs suggests exploiting their action to modulate the impaired healing phase. Furthermore, next to their natural wound healing capacity, EVs can be engineered for better defined pharmaceutical purposes, such as carrying specific cargo or targeting specific destinations by labelling them with certain surface proteins. This review aims to promote scientific awareness in basic and translational research of EVs by summarizing the current knowledge about their natural role in each stage of skin repair and the most recent findings in application areas, such as wound healing, skin regeneration, and treatment of dermal diseases, including the stem cell-derived, plant-derived, and engineered EVs.

EV Cargo Sorting in Therapeutic Development for Cardiovascular Disease

Cardiovascular disease remains the leading cause of morbidity and mortality in the world. Thus, therapeutic interventions to circumvent this growing burden are of utmost importance. Extracellular vesicles (EVs) actively secreted by most living cells, play a key role in paracrine and endocrine intercellular communication via exchange of biological molecules. As the content of secreted EVs reflect the physiology and pathology of the cell of their origin, EVs play a significant role in cellular homeostasis, disease pathogenesis and diagnostics. Moreover, EVs are gaining popularity in clinics as therapeutic and drug delivery vehicles, transferring bioactive molecules such as proteins, genes, miRNAs and other therapeutic agents to target cells to treat diseases and deter disease progression. Despite our limited but growing knowledge of EV biology, it is imperative to understand the complex mechanisms of EV cargo sorting in pursuit of designing next generation EV-based therapeutic delivery systems. In this review, we highlight the mechanisms of EV cargo sorting and methods of EV bioengineering and discuss engineered EVs as a potential therapeutic delivery system to treat cardiovascular disease.

Amniotic fluid-derived exosomes improved spermatogenesis in a rat model of azoospermia

AIMS

This study aimed to explore the therapeutic effects of amniotic fluid-derived extracellular vesicles including exosomes (AF-Exos) on the recovery of sperm production capacity in a rat model of azoospermia.

MAIN METHODS

The non-obstructive azoospermia (NOA) was induced in rats using intratesticular administration of Busulfan. Azoospermia was confirmed by testis histology. AF-Exos samples containing 10 or 40 μg exosomal proteins were injected into testicular tissue of NOA rats. After two months, the recovery of spermatogenesis was monitored via histopathological staining, spermiogram, and hormonal analysis. Immunohistochemistry staining for OCT-3/4 was used to identify of spermatogonial progenitors. The expression of DAZL and VASA, was also measured.

KEY FINDINGS

AF-Exos exhibited sphere-shaped morphology with the mean diameter and zeta potential of 50 ± 7.521 nm and -7.16 mV. Immunoblots revealed that isolated nanoparticles were CD63, CD9, and CD81 positive. Histopathological evaluation revealed that spermatogenesis was improved significantly in NOA rats after AF-Exos injection. Data showed that the sperm parameters and spermatogenesis index were significantly improved after AF-Exos injection compared to azoospermic groups. OCT-3/4⁺ cells were increased in NOA rats after AF-Exos injection, showing the restoration of spermatogenesis. In the present study, both doses of exosome (10 and 40 μg) restored the testicular function of NOA rats. DAZL and VASA were increased significantly in animals who received 40 μg exosomal protein compared to azoospermic rats. Except in a high dose of AF-Exos (40 μg) for Testosterone and FSH, no statistically significant differences were found regarding hormones post-exosome injection.

SIGNIFICANCE

Our study demonstrated that AF-Exos regenerated spermatogenesis and improved sperm quality in NOA rats.

Mesenchymal stem cell (MSC)-derived exosomes as a cell-free therapy for patients Infected with COVID-19: Real opportunities and range of promises

There are no commercially available effective antiviral medications or vaccines to deal with novel coronavirus disease (COVID-19). Hence there is a substantial unmet medical need for new and efficacious treatment options for COVID-19. Most COVID-19 deaths result from acute respiratory distress syndrome (ARDS). This virus induces excessive and aberrant inflammation so it is important to control the inflammation as soon as possible. To date, results of numerous studies have been shown that mesenchymal stem cells and their derivatives can suppress inflammation. Exosomes function as intercellular communication vehicles to transfer bioactive molecules (based on their origins), between cells. In this review, the recent exosome-based clinical trials for the treatment of COVID-19 are presented. Potential therapy may include the following items: First, using mesenchymal stem cells secretome. Second, incorporating specific miRNAs and mRNAs into exosomes and last, using exosomes as carriers to deliver drugs.

The potential diagnostic and therapeutic applications of exosomes in drug-induced liver injury

Drug-induced liver injury (DILI) has gradually become a global public medical problem, which can be caused by more than 1000 currently available drugs. Unfortunately, the diagnosis and treatment of DILI are limited and imperfect. Exosomes can be secreted by a variety of cells and tissues in the body, rich in cell-type specific proteins, nucleic acids and lipids, which has been widely studied as an important intercellular communication vehicle in liver diseases. Emerging data suggest that circulating exosomes and their cargos can be used as minimally-invasive sources of potential molecular biomarkers for the early detection, monitoring and evaluation of DILI. Exosomes in the urine were also found to contain proteins or RNAs that were indicative of DILI. In addition, exosomes derived from mesenchymal stem cell or hepatocyte are considered potential therapeutic agents to promote liver regenerative responses, modulate inflammatory response and deduce hepatocytes apoptosis. Based on the current findings, we suggest the potential applications of exosomes as biomarkers and therapeutics for DILI.

Mechanistic Understanding From Molecular Dynamics Simulation in Pharmaceutical Research 1: Drug Delivery

In this review, we outline the growing role that molecular dynamics simulation is able to play as a design tool in drug delivery. We cover both the pharmaceutical and computational backgrounds, in a pedagogical fashion, as this review is designed to be equally accessible to pharmaceutical researchers interested in what this new computational tool is capable of and experts in molecular modeling who wish to pursue pharmaceutical applications as a context for their research. The field has become too broad for us to concisely describe all work that has been carried out; many comprehensive reviews on subtopics of this area are cited. We discuss the insight molecular dynamics modeling has provided in dissolution and solubility, however, the majority of the discussion is focused on nanomedicine: the development of nanoscale drug delivery vehicles. Here we focus on three areas where molecular dynamics modeling has had a particularly strong impact: (1) behavior in the bloodstream and protective polymer corona, (2) Drug loading and controlled release, and (3) Nanoparticle interaction with both model and biological membranes. We conclude with some thoughts on the role that molecular dynamics simulation can grow to play in the development of new drug delivery systems.

Diagnostic and prognostic potential of circulating miRNAs for intracranial aneurysms

Intracranial aneurysm (IA) is an abnormal focal dilation of an artery in the brain that results from a weakening of the inner muscular layer of a blood vessel wall. IAs represent the most common etiology of nontraumatic subarachnoid hemorrhage (SAH). Despite technological advances in the treatment and use of new diagnostic methods for IAs, they continue to pose a significant risk of mortality and disability. Thus, early recognition of IA with a high risk of rupture is crucial for the stratification of patients with such a formidable disease. MicroRNAs (miRNA) are endogenous noncoding RNAs of 18-22 nucleotides that regulate gene expression at the post-transcriptional level through interaction with 3'-untranslated regions (3'UTRs) of the target mRNAs. MiRNAs are involved in the pathogenesis of IAs, including in the mechanisms of formation, growth, and rupture. It is known that in many biological fluids of the human body, such as blood or cerebrospinal fluid (CSF), numerous miRNAs, called circulating miRNAs, have been detected. The expression profile of circulating miRNAs represents a certain part of the cells in which they are modified and secreted in accordance with the physiological or pathological conditions of these cells. Circulating miRNAs can be secreted from cells into human biological fluids in extracellular vesicles or can be bound to Ago2 protein, which makes them resistant to the effects of RNAse. Therefore, circulating miRNAs are considered as new potential biomarkers of interest in many diseases, including IA.

Small extracellular vesicles (sEVs): discovery, functions, applications, detection methods and various engineered forms

INTRODUCTION

Extracellular vesicles (EVs) are cell-created delivery systems of proteins, lipids, or nucleic acids, and means of extracellular communication. Though sEVs were initially considered to be the waste disposal mechanism, today they are at the forefront of research with different biological and pathological functions. Such EVs play a key role in the immunoregulation, CNS development, nervous system physiology, mammary gland development, induction of immunosuppression in pregnancy, the developmental signaling pathways, regeneration of different tissues, inflammation, angiogenesis, coagulation, apoptosis, stem cell differentiation, and extracellular matrix turnover.

AREAS COVERED

SEVs contribute to the pathogenesis of different cancers and the progression of various neurodegenerative diseases, infections, as well as metabolic and cardiovascular diseases. Expert Opinion: There is no exact classification for EVs; however, according to size, density, morphological features, content, and biogenesis, they can be categorized into three major classes: microvesicles (ectosomes or microparticles), apoptotic bodies, and sEVs. SEVs, as an important class of EVs, have a crucial role in distinct biological functions. Moreover, shedding light on different structural and molecular aspects of sEV has led to their application in various therapeutic, diagnostic, and drug delivery fields. In this review, we have endeavored to elaborate on different aspects of EVs, especially sEVs.

Role of Extracellular Vesicles in Autoimmune Pathogenesis

Autoimmune diseases are conditions that emerge from abnormal immune responses to natural parts of the body. Extracellular vesicles (EVs) are membranous structures found in almost all types of cells. Because EVs often transport “cargo” between cells, their ability to crosstalk may be an important communication pathway within the body. The pathophysiological role of EVs is increasingly recognized in autoimmune diseases, including multiple sclerosis, rheumatoid arthritis, systemic lupus erythematosus, Sjogren's syndrome, Type 1 diabetes, and autoimmune thyroid disease. EVs are considered as biomarkers of these diseases. This article outlines existing knowledge on the biogenesis of EVs, their role as messegers in cellular communication and the function in T/B cell differentiation and maturation, and focusing on their potential application in autoimmune diseases.

The novel target：exosoms derived from M2 macrophage

More and more exosome-based therapeutics are being developed with advances in nanotechnology and precision medicine. Exosome is a kind of tiny vesicles with a bilayer of phospholipids, which can transfer biological macromolecules to recipients to influence the biological process. M2 macrophages are closely related to the occurrence and development of serious diseases such as tumor. In addition to the traditional concept of macrophage functions such as opsonization, secretion of cytokines and other soluble factors, some studies have found that the exosome derived from M2 macrophages can influence the development of disease by carrying microRNA, long noncodingRNA and functional proteins to regulate target gene expression as well as related proteins synthesis recently. Here, we outlined the biogenesis of the exosome and its biological functions in disease. Then we focused on elucidating the effects of the exosome derived from M2 macrophages on several diseases and its mechanisms. Finally, we discussed the appropriateness and inappropriateness in existing potential applications based on exosomes and macrophages.

Circulating MicroRNAs from Serum Exosomes May Serve as a Putative Biomarker in the Diagnosis and Treatment of Patients with Focal Cortical Dysplasia

Focal cortical dysplasia (FCD) is a congenital malformation of cortical development where the cortical neurons located in the brain area fail to migrate in the proper formation. Epilepsy, particularly medically refractory epilepsy, is the most common clinical presentation for all types of FCD. This study aimed to explore the expression change of circulating miRNAs in patients with FCD from serum exosomes. A total of nine patients with FCD and four healthy volunteers were enrolled in this study. The serum exosomes were isolated from the peripheral blood of the subjects. Transmission electron microscopy (TEM) was used to identify the exosomes. Both exosomal markers and neuronal markers were detected by Western blotting analysis to prove that we could obtain central nervous system-derived exosomes from the circulation. The expression profiles of circulating exosomal miRNAs were assessed using next-generation sequencing analysis (NGS). We obtained a total of 107 miRNAs with dominant fold change (>2-fold) from both the annotated 5p-arm and 3p-arm of 2780 mature miRNAs. Based on the integrated platform of HMDD v3.2, miRway DB and DIANA-miRPath v3.0 online tools, and confirmed by MiRBase analysis, four potentially predicted miRNAs from serum exosomes in patients with FCD were identified, including miR194-2-5p, miR15a-5p, miR-132-3p, and miR-145-5p. All four miRNAs presented upregulated expression in patients with FCD compared with controls. Through Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis and pathway category of four target miRNAs, we found eight possible signaling pathways that may be related to FCD. Among them, we suggest that the mTOR signaling pathway, PI3K-Akt signaling pathway, p53 signaling pathway, and cell cycle regulation and TGF-beta signaling pathway are high-risk pathways that play a crucial role in the pathogenesis of FCD and refractory epilepsy. Our results suggest that the circulating miRNAs from exosomes may provide a potential biomarker for diagnostic, prognostic, and therapeutic adjuncts in patients with FCD and refractory epilepsy.

Bone marrow stromal cells-derived exosomes target DAB2IP to induce microglial cell autophagy, a new strategy for neural stem cell transplantation in brain injury

Bone marrow stromal cells (MSCs) are a useful source of stem cells for the treatment of various brain injury diseases due to their abundant supply and fewer ethical problems compared with transplant treatment. However, the clinical application of MSCs is limited due to allograft rejection and immunosuppression in the process of MSCs transplantation. According to previous studies, microglial cell autophagy occurs following co-culture with MSCs. In the present study, exosomes were obtained from MSCs and subsequently characterized using transmission electron microscopy, atomic force microscopy and dynamic light scattering particle size analysis. The type of microRNAs (miRs) found in the exosomes was then analyzed via gene chip. The results demonstrated that microglial cell autophagy could be induced by exosomes. This mechanism was therefore investigated further via reverse transcription-quantitative PCR, western blotting and luciferase assays. These results demonstrated that exosomes from MSCs could induce microglial cell autophagy through the miR-32-mediated regulation of disabled homolog 2-interacting protein, thus providing a theoretical basis for the clinical application of miRs in MSCs.

MicroRNAs-containing extracellular vesicles in bone remodeling: An emerging frontier

Bone remodeling is a complex and constant process, which is maintained by well-regulated communication among various cells. Extracellular vesicles (EVs) are small vesicles, which could provide a protective environment for the transportation of various functional molecules. It has been shown that EVs could dock with distant and/or neighboring target cells, deliver cargoes to these specific cells and alter their fates. MicroRNAs (miRNAs), single-stranded non-coding RNAs with 22-26 nucleotides, could bind to mRNAs and repress the translation or stimulate the degradation of mRNAs. It is reported that EVs could serve as the mail carriers, which could cargo miRNAs to exchange information between different cells and act through a novel way to regulate signaling pathways during bone remodeling. In this review, we summarize the function of EV-miRNAs in the communication among mesenchymal stem cells (MSCs), osteoblasts, osteoclasts, osteocytes, and myoblasts during bone remodeling, as well as the key signaling molecules which are involved in this process. The roles of EV-miRNAs in sending intercellular messages in the microenvironment of bone remodeling could shed new light on the development of tissue engineering, and provide novel diagnostic markers and therapeutic targets of bone-related diseases.

A Method to Analyze Urinary Extracellular Vesicles

Extracellular vesicles (EVs) play an important role in cell-to-cell communication by carrying molecular messages that reflect physiological and pathological conditions of the parent cells. EVs have been identified in all body fluids; and among them, urine stands out as a sample that is easy and inexpensive to obtain and can be collected over time to monitor changes. Various protocols have been established to study urinary extracellular vesicles (UEVs) and they have shown great potential as a biomarker source for clinical applications, not only for urological, but also non-urological diseases. Due to the high variability and low reproducibility of pre-analytical and analytical methods for UEVs, establishing a standardized protocol remains a challenge in the field of diagnosis. Here, we review UEV studies and present the techniques that are most commonly used, those that have been applied as new developments, and those that have the most potential for future applications. The workflow procedures from the sampling step to the qualitative and quantitative analysis steps are summarized along with advantages and disadvantages of the methodologies, in order to give consideration for choosing the most promising and suitable method to analyze human UEVs.