BV2-derived extracellular vesicles modulate microglia inflammatory profile, neuronal plasticity, and behavioural performances in late adult mice

BACKGROUND

During aging, both the brain and the immune system undergo a progressive impairment of physiological functions. Microglia, the immunocompetent cells of the central nervous system, shift towards a chronic mild inflammatory state that impacts brain homeostasis. Extracellular vesicles (EVs) released by microglia transport packages of molecular information that mirror the inflammatory status of donor cells and modulate the inflammatory phenotype of recipient microglia and other cell types.

RESULTS

We demonstrated that intranasal administration of EVs derived from microglial-like BV2 cells to late adult mice (16-20 months of age) shifts microglia toward a "juvenile" morphology affecting their inflammatory profile. Mice treated with BV2-derived EVs have a reduction of anxiety-like behavior and an increased spatial learning, with sex-dependent differences. Further, BV2-derived EVs increased neuronal plasticity both in male and female mice. These findings suggest the involvement of microglial cells in vesicles-mediated anti-aging effect.

CONCLUSIONS

Our data indicate that BV2-derived EVs could represent a resource to slow down age-dependent inflammation in the mouse brain.

Traumatic brain injury: Advances in coagulopathy (Review)

Trauma is a prevalent cause of coagulopathy, with traumatic brain injury (TBI) accompanied by coagulation disorders particularly linked to adverse outcomes. TBI is distinguished by minimal bleeding volume and unique injury sites, which precipitate complex coagulation disturbances. Historically, research into trauma-induced coagulopathy has primarily concentrated on the molecular biology and pathophysiology of endogenous anticoagulation and inflammation. Nonetheless, recognizing that cells are the fundamental units of structure and function in all living organisms, the present review aimed to distill our understanding of coagulopathy post-TBI by elucidating the intricate cellular mechanisms involving endothelial cells, neutrophils and platelets. Additionally, this study evaluates the strengths and weaknesses of various diagnostic tools and discusses the characteristics of pharmacological treatments and potential therapies for patients with TBI and coagulation disorders. The aim of this review is to amalgamate recent updates in mechanistic research and innovative diagnostic and therapeutic methodologies, thereby fostering the progression of precision medicine within this specialized domain.

Insights into degradation and targeting of the photoreceptor channelrhodopsin-1

In Chlamydomonas, the directly light-gated, plasma membrane-localized cation channels channelrhodopsins ChR1 and ChR2 are the primary photoreceptors for phototaxis. Their targeting and abundance is essential for optimal movement responses. However, our knowledge how Chlamydomonas achieves this is still at its infancy. Here we show that ChR1 internalization occurs via light-stimulated endocytosis. Prior or during endocytosis ChR1 is modified and forms high molecular mass complexes. These are the solely detectable ChR1 forms in extracellular vesicles and their abundance therein dynamically changes upon illumination. The ChR1-containing extracellular vesicles are secreted via the plasma membrane and/or the ciliary base. In line with this, ciliogenesis mutants exhibit increased ChR1 degradation rates. Further, we establish involvement of the cysteine protease CEP1, a member of the papain-type C1A subfamily. ΔCEP1-knockout strains lack light-induced ChR1 degradation, whereas ChR2 degradation was unaffected. Low light stimulates CEP1 expression, which is regulated via phototropin, a SPA1 E3 ubiquitin ligase and cyclic AMP. Further, mutant and inhibitor analyses revealed involvement of the small GTPase ARL11 and SUMOylation in ChR1 targeting to the eyespot and cilia. Our study thus defines the degradation pathway of this central photoreceptor of Chlamydomonas and identifies novel elements involved in its homoeostasis and targeting.

miR-9-5p is Downregulated in Serum Extracellular Vesicles of Patients Treated with Biperiden After Traumatic Brain Injury

Traumatic brain injury (TBI) is a prevalent and debilitating condition, which often leads to the development of post-traumatic epilepsy (PTE), a condition that yet lacks preventive strategies. Biperiden, an anticholinergic drug, is a promising candidate that has shown efficacy in murine models of PTE. MicroRNAs (miRNAs), small regulatory RNAs, can help in understanding the biological basis of PTE and act as TBI- and PTE-relevant biomarkers that can be detected peripherally, as they are present in extracellular vesicles (EVs) that cross the blood-brain barrier. This study aimed to investigate miRNAs in serum EVs from patients with TBI, and their association with biperiden treatment and PTE. Blood samples of 37 TBI patients were collected 10 days after trauma and treatment initiation in a double-blind clinical trial. A total of 18 patients received biperiden, with three subjects developing PTE, and 19 received placebo, with two developing PTE. Serum EVs were characterized by size distribution and protein profiling, followed by high-throughput sequencing of the EV miRNome. Differential expression analysis revealed no significant differences in miRNA expression between TBI patients with and without PTE. Interestingly, miR-9-5p displayed decreased expression in biperiden-treated patients compared to the placebo group. This miRNA regulates genes enriched in stress response pathways, including axonogenesis and neuronal death, relevant to both PTE and TBI. These findings indicate that biperiden may alter miR-9-5p expression in serum EVs, which may play a role in TBI resolution.

Streptococcus mutans outer membrane vesicles affect inflammasome activation and the glycolysis of macrophages

Recent studies indicate that bacterial outer membrane vesicles (OMVs) play a significant role in bacterial virulence and pathogenicity. Streptococcus mutans (S. mutans), a principal pathogen in dental caries, secretes a substantial number of OMVs. However, the impact of S. mutans OMVs on oral health and their underlying pathogenic mechanisms remain poorly understood. Macrophages were the initial innate immune cells to respond to bacterial invaders and their products. Therefore, we purified S. mutans OMVs, which stimulated macrophages. Compared to controls, RT-PCR and ELISA analyses revealed that S. mutans OMVs significantly increased the production of IL-1β, IL-6, TNF-α and IL-8, with IL-1β being notably elevated. IL-1β production and secretion are tightly regulated by the inflammasome. Western blot analyses demonstrated that S. mutans OMVs upregulated the expression of inflammasome components, including NLRP3, NLRC4, ASC and AIM2, with a marked increase in NLRP3 expression. Silencing different inflammasome components with siRNA revealed a reduction in IL-1β secretion induced by S. mutans OMVs, particularly through NLRP3. Additionally, ATP production and K+ efflux were found to be crucial for NLRP3 activation. Prolonged stimulation with S. mutans OMVs resulted in increased lactate production and elevated expression of glycolysis-related genes Glut-1, PFKFB3, and HK I, indicating that S. mutans OMVs significantly induce macrophage glycolysis. Furthermore, S. mutans OMVs were shown to enhance biofilm formation, increase S. mutans colonisation on epithelial cells, and inhibit macrophage phagocytosis, thereby improving the survival of S. mutans in the oral cavity. In summary, S. mutans OMVs promote the survival of S. mutans in the mouth through multiple mechanisms, potentially influencing the development of dental caries.

Advances and Prospects in Liquid Biopsy Techniques for Malignant Tumor Diagnosis and Surveillance

Liquid biopsy technology provides invaluable support for the early diagnosis of tumors and surveillance of disease course by detecting tumor-related biomarkers in bodily fluids. Currently, liquid biopsy techniques are mainly divided into two categories: biomarker and label-free. Biomarker liquid biopsy techniques utilize specific antibodies or probes to identify and isolate target cells, exosomes, or molecules, and these techniques are widely used in clinical practice. However, they have certain limitations including dependence on tumor markers, alterations in cell biological properties, and high cost. In contrast, label-free liquid biopsy techniques directly utilize physical or chemical properties of cells, exosomes, or molecules for detection and isolation. These techniques have the advantage of not needing labeling, not impacting downstream analysis, and low detection cost. However, most are still in the research stage and not yet mature. This review first discusses recent advances in liquid biopsy techniques for early tumor diagnosis and disease surveillance. Several current techniques are described in detail. These techniques exploit differences in biomarkers, size, density, deformability, electrical properties, and chemical composition in tumor components to achieve highly sensitive tumor component identification and separation. Finally, the current research progress is summarized and the future research directions of the field are discussed.

Extracellular vesicles powered cancer immunotherapy: Targeted delivery of adenovirus-based cancer vaccine in humanized melanoma model

Malignant melanoma, a rapidly spreading form of skin cancer, is becoming more prevalent worldwide. While surgery is successful in treating early-stage melanoma, patients with advanced disease have only a 20 % chance of surviving beyond five years. Melanomas with mutations in the NRAS gene are characterized for a more aggressive tumor biology, poorer prognosis and shorter survival. Hence, new therapeutic strategies are needed, especially for this specific group of patients. Novel approaches, such as cancer vaccines, offer promising solutions by stimulating the anti-tumor immune response. Nevertheless, their clinical efficacy is still modest and more effective approaches are required. Herein, we propose the systemic administration of the adenovirus-based cancer vaccine complexed in extracellular vesicles (EVs) with the aim of achieving a targeted therapeutic effect. The vaccine was based on previously tested oncolytic adenovirus Ad5/3-D24-ICOSL-CD40L in combination with melanoma-specific antigens targeting NRAS mutations to enhance the anticancer effect. The antineoplastic properties of the oncolytic vaccine were evaluated in xenograft MUG Mel-2 melanoma BALB/c nude mice. Moreover, to mimic the tumor microenvironment, while investigating at the same time immune cell infiltration and drug penetration, we established a 3D co-culture model based on human NRAS mutated MUG Mel-2 spheroids and PBMCs (HLA matched), which displayed a synergistic effect when treated with the cancer vaccine compared to relative controls. Subsequently, we investigated the systemic delivery of the vaccine in EV formulations in a humanized NSG MUG Mel-2 melanoma mouse model. Our study provides a promising strategy for a tumor-targeted vaccine delivery by EVs, resulting in improved anticancer efficacy and increased infiltration of tumor-infiltrating lymphocytes. This study explores the potential of EVs for the selective delivery of cancer vaccines against malignancies, such as NRAS melanoma. Overall, this research could pave the way for applying autologous EVs as a safe and efficacious tool for targeted cancer therapy.

Role of mir-32-3p in the diagnosis and risk assessment of osteoporotic fractures

BACKGROUND

Osteoporotic fractures (OPF) are fractures that occur with low-energy injuries or during daily activities, representing a serious consequence of osteoporosis (OP). With the worsening of population aging, the number of OPF patients continues to expand, causing a significant burden on families and society. Consequently, it is significant to diagnose and analyze OPF at the molecular level.

OBJECTIVE

The aim of this research was to explore the diagnostic value of miR-32-3p in OPF patients and to exploit new biomarkers for clinical applications.

METHODS

The miR-32-3p expression level of patients was detected by RT-qPCR. Diagnostic accuracy of miR-32-3p analyzed adopting ROC curve. Additionally, the risk factors correlation with the occurrence of OPF were assessed by logistic analysis. The effect of miR-32-3p on BMSCs was verified by in vitro transfection experiments.

RESULTS

miR-32-3p expression was lower in OPF patients than in OP patients. ROC curve implied that miR-32-3p exhibits commendable sensitivity (88.9%) and specificity (75.6%) to differentiate between OP and OPF patients (AUC = 0.905, P < 0.001). Furthermore, miR-32-3p was correlated with the development of OPF and was a risk factor for OPF (P < 0.001). Functional assays revealed that transfection with miR-32-3p mimic could promote proliferation and inhibit apoptosis, whereas transfection with miR-32-3p inhibitor had the opposite effect.

CONCLUSION

miR-32-3p demonstrates significant diagnostic potential for OPF patients. It is likely that miR-32-3p probably is a new diagnosis biomarker for OPF, offering promising therapeutic avenues through targeted interventions.

Prognosis prediction of PDAC via detection of O-glycan altered extracellular vesicles in perioperative sera

Pancreatic ductal adenocarcinoma (PDAC) is a fatal malignancy due to the difficulty in diagnosis and poor prognosis because of the high recurrence rate, necessitating reliable biomarkers to improve the diagnosis and prognosis. However, the existing markers have limitations. We previously identified extracellular vesicles (EVs) recognized by O-glycan-binding lectins (Amaranthus caudatus agglutinin [ACA]) as a novel diagnostic biomarker for PDAC using an EV-counting system (ExoCounter). This retrospective study analyzed changes in ACA-positive EVs in perioperative PDAC serum and its association with prognosis using ExoCounter. Absolute EV levels in the pre- and postoperative sera of 44 patients who underwent curative pancreatectomy for PDAC were quantified using ExoCounter. The carbohydrate antigen 19-9 levels declined in most samples postoperatively, and presented no correlation with poor prognosis. In contrast, ACA-positive EVs increased in serum at 7 days postoperatively in 27 of 44 patients (61.4%). We therefore divided participants with ACA-positive EVs before and after surgery into elevation and decline groups. The overall survival (OS) and recurrence-free survival (RFS) of patients with higher ACA-positive EVs were significantly shorter than those with lower ACA-positive EVs (26.1 months vs. not reached, P = 0.018; 11.9 vs. 38.6 months, P = 0.013). Multivariable analysis revealed that ACA-positive EV elevation in postoperative serum was an independent prognostic factor for poor OS (hazard ratio [HR] = 3.891, P = 0.023) and RFS (HR = 2.650, P = 0.024). The detection of ACA-positive EVs in perioperative serum may be used to predict the prognosis of PDAC in the early postoperative period.

Extracellular vesicles from human-induced pluripotent stem cell-derived neural stem cells alleviate proinflammatory cascades within disease-associated microglia in Alzheimer's disease

As current treatments for Alzheimer's disease (AD) lack disease-modifying interventions, novel therapies capable of restraining AD progression and maintaining better brain function have great significance. Anti-inflammatory extracellular vesicles (EVs) derived from human induced pluripotent stem cell (hiPSC)-derived neural stem cells (NSCs) hold promise as a disease-modifying biologic for AD. This study directly addressed this issue by examining the effects of intranasal (IN) administrations of hiPSC-NSC-EVs in 3-month-old 5xFAD mice. IN administered hiPSC-NSC-EVs incorporated into microglia, including plaque-associated microglia, and encountered astrocyte soma and processes in the brain. Single-cell RNA sequencing revealed transcriptomic changes indicative of diminished activation of microglia and astrocytes. Multiple genes linked to disease-associated microglia, NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3)-inflammasome and interferon-1 (IFN-1) signalling displayed reduced expression in microglia. Adding hiPSC-NSC-EVs to cultured human microglia challenged with amyloid-beta oligomers resulted in similar effects. Astrocytes also displayed reduced expression of genes linked to IFN-1 and interleukin-6 signalling. Furthermore, the modulatory effects of hiPSC-NSC-EVs on microglia in the hippocampus persisted 2 months post-EV treatment without impacting their phagocytosis function. Such effects were evidenced by reductions in microglial clusters and inflammasome complexes, concentrations of mediators, and end products of NLRP3 inflammasome activation, the expression of genes and/or proteins involved in the activation of p38/mitogen-activated protein kinase and IFN-1 signalling, and unaltered phagocytosis function. The extent of astrocyte hypertrophy, amyloid-beta plaques, and p-tau were also reduced in the hippocampus. Such modulatory effects of hiPSC-NSC-EVs also led to better cognitive and mood function. Thus, early hiPSC-NSC-EV intervention in AD can maintain better brain function by reducing adverse neuroinflammatory signalling cascades, amyloid-beta plaque load, and p-tau. These results reflect the first demonstration of the efficacy of hiPSC-NSC-EVs to restrain neuroinflammatory signalling cascades in an AD model by inducing transcriptomic changes in activated microglia and reactive astrocytes.

Comprehensive multi-omics profiling identifies novel molecular subtypes of pancreatic ductal adenocarcinoma

Pancreatic cancer, a highly fatal malignancy, is predicted to rank as the second leading cause of cancer-related death in the next decade. This highlights the urgent need for new insights into personalized diagnosis and treatment. Although molecular subtypes of pancreatic cancer were well established in genomics and transcriptomics, few known molecular classifications are translated to guide clinical strategies and require a paradigm shift. Notably, chronically developing and continuously improving high-throughput technologies and systems serve as an important driving force to further portray the molecular landscape of pancreatic cancer in terms of epigenomics, proteomics, metabonomics, and metagenomics. Therefore, a more comprehensive understanding of molecular classifications at multiple levels using an integrated multi-omics approach holds great promise to exploit more potential therapeutic options. In this review, we recapitulated the molecular spectrum from different omics levels, discussed various subtypes on multi-omics means to move one step forward towards bench-to-beside translation of pancreatic cancer with clinical impact, and proposed some methodological and scientific challenges in store.

Staphylococcus aureus membrane vesicles: an evolving story

Staphylococcus aureus is an important bacterial pathogen that causes a wide variety of human diseases in community and hospital settings. S. aureus employs a diverse array of virulence factors, both surface-associated and secreted, to promote colonization, infection, and immune evasion. Over the past decade, a growing body of research has shown that S. aureus generates extracellular membrane vesicles (MVs) that package a variety of bacterial components, many of which are virulence factors. In this review, we summarize recent advances in our understanding of S. aureus MVs and highlight their biogenesis, cargo, and potential role in the pathogenesis of staphylococcal infections. Lastly, we present some emerging questions in the field.

Lethal pulmonary thromboembolism in mice induced by intravenous human umbilical cord mesenchymal stem cell-derived large extracellular vesicles in a dose- and tissue factor-dependent manner

Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) have obvious advantages over MSC therapy. But the strong procoagulant properties of MSC-EVs pose a potential risk of thromboembolism, an issue that remains insufficiently explored. In this study, we systematically investigated the procoagulant activity of large EVs derived from human umbilical cord MSCs (UC-EVs) both in vitro and in vivo. UC-EVs were isolated from cell culture supernatants. Mice were injected with UC-EVs (0.125, 0.25, 0.5, 1, 2, 4 μg/g body weight) in 100 μL PBS via the tail vein. Behavior and mortality were monitored for 30 min after injection. We showed that these UC-EVs activated coagulation in a dose- and tissue factor-dependent manner. UC-EVs-induced coagulation in vitro could be inhibited by addition of tissue factor pathway inhibitor. Notably, intravenous administration of high doses of the UC-EVs (1 μg/g body weight or higher) led to rapid mortality due to multiple thrombus formations in lung tissue, platelets, and fibrinogen depletion, and prolonged prothrombin and activated partial thromboplastin times. Importantly, we demonstrated that pulmonary thromboembolism induced by the UC-EVs could be prevented by either reducing the infusion rate or by pre-injection of heparin, a known anticoagulant. In conclusion, this study elucidates the procoagulant characteristics and mechanisms of large UC-EVs, details the associated coagulation risk during intravenous delivery, sets a safe upper limit for intravenous dose, and offers effective strategies to prevent such mortal risks when high doses of large UC-EVs are needed for optimal therapeutic effects, with implications for the development and application of large UC-EV-based as well as other MSC-EV-based therapies.

Mechanisms of extracellular vesicle uptake and implications for the design of cancer therapeutics

The translation of pre-clinical anti-cancer therapies to regulatory approval has been promising, but slower than hoped. While innovative and effective treatments continue to achieve or seek approval, setbacks are often attributed to a lack of efficacy, failure to achieve clinical endpoints, and dose-limiting toxicities. Successful efforts have been characterized by the development of therapeutics designed to specifically deliver optimal and effective dosing to tumour cells while minimizing off-target toxicity. Much effort has been devoted to the rational design and application of synthetic nanoparticles to serve as targeted therapeutic delivery vehicles. Several challenges to the successful application of this modality as delivery vehicles include the induction of a protracted immune response that results in their rapid systemic clearance, manufacturing cost, lack of stability, and their biocompatibility. Extracellular vesicles (EVs) are a heterogeneous class of endogenous biologically produced lipid bilayer nanoparticles that mediate intercellular communication by carrying bioactive macromolecules capable of modifying cellular phenotypes to local and distant cells. By genetic, chemical, or metabolic methods, extracellular vesicles (EVs) can be engineered to display targeting moieties on their surface while transporting specific cargo to modulate pathological processes following uptake by target cell populations. This review will survey the types of EVs, their composition and cargoes, strategies employed to increase their targeting, uptake, and cargo release, and their potential as targeted anti-cancer therapeutic delivery vehicles.

Characterization of the Angiogenic and Proteomic Features of Circulating Exosomes in a Canine Mandibular Model of Distraction Osteogenesis

Distraction osteogenesis (DO) represents a highly effective method for addressing significant bone defects; however, it necessitates a long treatment period. Exosomes are key mediators of intercellular communication. To investigate their role in the angiogenesis and osteogenesis of DO, we established a canine mandibular DO model with a bone defect (BD) group as the control. Higher levels of angiogenesis were observed in the regenerating tissue from the DO group compared to those from the BD group, accompanied by earlier osteogenesis. Proteomic analysis was performed on circulating exosomes at different phases of the DO using a data-independent acquisition method. Data are available via ProteomeXchange with the identifier PXD050531. The results indicated specific alterations in circulating exosome proteins at different phases of DO, reflecting the regenerative activities in the corresponding tissues. Notably, fibronectin 1 (FN1), thrombospondin 1 (THBS1), and transferrin receptor (TFRC) emerged as potential candidate proteins related to the angiogenic response in DO. Further cellular experiments validated the potential of DO-associated circulating exosomes to promote angiogenesis in endothelial cells. Collectively, these data reveal previously unknown mechanisms that may underlie the efficacy of DO and suggest that exosome-derived proteins may be useful as therapeutic targets for strategies designed to improve DO-related angiogenesis and bone regeneration.

Mitochondrial derived vesicles- Quo Vadis?

Mitochondria are dynamic, intracellular organelles with a separate genome originating from prokaryotes. They perform numerous functions essential for cellular metabolism and energy production. Mitochondrial-derived vesicles (MDVs) are single or double membrane-enclosed vesicles, formed and released from the mitochondrial sub-compartments into the cytosol, in response to various triggers. MDVs interact with other organelles such as lysosomes and peroxisomes or may be incorporated and excreted via extracellular vesicles (EVs). MDVs selectively incorporate diverse protein and lipid cargoes and are involved in various functions such as mitochondrial quality control, immunomodulation, energy complementation, and compartmentalization and transport. This review aims to provide a summary of the current knowledge of MDVs biogenesis, release, cargoes, and roles.

Exosomal miR-21-5p derived from endometrial stromal cells promotes angiogenesis by targeting TIMP3 in ovarian endometrial cysts

Endometriosis is a multifactorial gynecological disease, with angiogenesis as a key hallmark. The role of exosomal microRNAs (miRNAs) in endometriosis is not well understood. This study investigates differentially expressed exosomal miRNAs linked to angiogenesis in endometriosis, clarifies their molecular mechanisms, and identifies potential targets. Primary endometrial stromal cells (ESCs) were cultured, and exosomes were extracted. In a co-culture system, ESC-derived exosomes were taken up by human umbilical vein endothelial cells (HUVECs). Endometriosis implant-ESC-derived exosomes (EI-EXOs) significantly promoted HUVEC proliferation, migration and tube formation compared to normal endometrium-exosomes (NE-EXOs), a finding consistent in vivo in mice. MiRNA sequencing and bioinformatics identified differentially expressed miR-21-5p from EI-EXOs, confirmed by RT-qPCR. The miR-21-5p inhibitor or GW4869 attenuated EI-EXO-induced HUVEC proliferation, migration, and tube formation. TIMP3 overexpression diminished the pro-angiogenic effect of EI-EXOs, which was reversed by adding EI-EXOs or upregulating miR-21-5p. These findings validate the crosstalk between ESCs and HUVECs mediated by exosomal miR-21-5p, and confirm the miR-21-5p-TIMP3 axis in promoting angiogenesis in endometriosis. KEY MESSAGES: ESC-derived exosomes were found to be taken up by recipient cells, i.e. HUVECs. Functionally, endometriosis implant-ESC-derived exosomes (EI-EXOs) could significantly promote the proliferation, migration and tube formation of HUVECs compared to normal endometrium-exosomes (NE-EXOs). Through miRNA sequencing and bioinformatics analysis, differentially expressed miR-21-5p released by EI-EXOs was chosen, as confirmed by qRT-PCR. miR-21-5p inhibitor or GW4869 was found to attenuate the proliferation, migration, and tube formation of HUVECs induced by EI-EXOs. In turn, TIMP3 overexpression diminished the pro-angiogenic effect of EI-EXOs, and this angiogenic phenotype was reversed once EI-EXOs were added or miR-21-5p was upregulated.

The Diagnostic Potential of Extracellular Vesicles Derived From the Blood Plasma of Glioblastoma Patients

BACKGROUND/AIM

Biomarkers for patients suffering from glioblastoma (GBM) are scarce. Extracellular vesicles (EV) are a promising candidate for a potential biomarker. Therefore, EV concentration could be a potential biomarker of tumor burden, volume, and prognosis.

PATIENTS AND METHODS

Large EV (lEV) and small EV (sEV) were isolated from 36 GBM patients' blood plasma by differential centrifugation. Nanoparticle tracking was used to measure EV concentration. Quantitative analysis of tumor volume was performed by evaluating T2/FLAIR relaxation times.

RESULTS

The mean size of lEV was 173.3 nm ± 18.2 nm, while sEV measured 148.3 ± 9.0 nm. Patients with higher lEV concentrations showed a trend towards longer overall survival (36.1 vs. 16.5 months, p=0.08). Regarding inflammatory markers, higher leukocyte count was positively correlated with higher sEV concentration (r2=0.3887, DF 21, p=0.0015). No significant relationship was found between lEV or sEV concentration and tumor volume.

CONCLUSION

Overall EV concentration in the peripheral blood is not a predictor of tumor volume. sEV concentration is associated with a potential pro-inflammatory metabolism.

Therapeutic potential of mesenchymal stem cell-derived extracellular vesicles: A focus on inflammatory bowel disease

BACKGROUND

Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) have emerged as key regulators of intercellular communication, orchestrating essential biological processes by delivering bioactive cargoes to target cells. Available evidence suggests that MSC-EVs can mimic the functions of their parental cells, exhibiting immunomodulatory, pro-regenerative, anti-apoptotic, and antifibrotic properties. Consequently, MSC-EVs represent a cell-free therapeutic option for patients with inflammatory bowel disease (IBD), overcoming the limitations associated with cell replacement therapy, including their non-immunogenic nature, lower risk of tumourigenicity, cargo specificity and ease of manipulation and storage.

MAIN TOPICS COVERED

This review aims to provide a comprehensive examination of the therapeutic efficacy of MSC-EVs in IBD, with a focus on their mechanisms of action and potential impact on treatment outcomes. We examine the advantages of MSC-EVs over traditional therapies, discuss methods for their isolation and characterisation, and present mechanistic insights into their therapeutic effects through transcriptomic, proteomic and lipidomic analyses of MSC-EV cargoes. We also discuss available preclinical studies demonstrating that MSC-EVs reduce inflammation, promote tissue repair and restore intestinal homeostasis in IBD models, and compare these findings with those of clinical trials.

CONCLUSIONS

Finally, we highlight the potential of MSC-EVs as a novel therapy for IBD and identify challenges and opportunities associated with their translation into clinical practice.

HIGHLIGHTS

The source of mesenchymal stem cells (MSCs) strongly influences the composition and function of MSC-derived extracellular vesicles (EVs), affecting their therapeutic potential. Adipose-derived MSC-EVs, known for their immunoregulatory properties and ease of isolation, show promise as a treatment for inflammatory bowel disease (IBD). MicroRNAs are consistently present in MSC-EVs across cell types and are involved in pathways that are dysregulated in IBD, making them potential therapeutic agents. For example, miR-let-7a is associated with inhibition of apoptosis, miR-100 supports cell survival, miR-125b helps suppress pro-inflammatory cytokines and miR-20 promotes anti-inflammatory M2 macrophage polarisation. Preclinical studies in IBD models have shown that MSC-EVs reduce intestinal inflammation by suppressing pro-inflammatory mediators (e.g., TNF-α, IL-1β, IL-6) and increasing anti-inflammatory factors (e.g., IL-4, IL-10). They also promote mucosal healing and strengthen the integrity of the gut barrier, suggesting their potential to address IBD pathology.

An updated review on the development of a nanomaterial-based field-effect transistor-type biosensors to detect exosomes for cancer diagnosis

Cancer, a life-threatening genetic disease caused by abnormalities in normal cell growth regulatory functions, poses a significant challenge that current medical technologies cannot fully overcome. The current desired breakthrough is to diagnose cancer as early as possible and increase survival rates through treatments tailored to the prognosis and appropriate follow-up. From a perspective that reflects this contemporary paradigm of cancer diagnostics, exosomes are emerging as promising biomarkers. Exosomes, serving as mobile biological information repositories of cancer cells, have been known to create a microtumor environment in surrounding cells, and significant insight into the clinical significance of cancer diagnosis targeting them has been reported. Therefore, there are growing interests in constructing a system that enables continuous screening with a focus on patient-friendly and flexible diagnosis, aiming to improve cancer screening rates through exosome detection. This review focuses on a proposed exosome-embedded biological information-detecting platform employing a field-effect transistor (FET)-based biosensor that leverages portability, cost-effectiveness, and rapidity to minimize the stages of sacrifice attributable to cancer. The FET-applied biosensing technique, stemming from variations in an electric field, is considered an early detection system, offering high sensitivity and a prompt response frequency for the qualitative and quantitative analysis of biomolecules. Hence, an in-depth discussion was conducted on the understanding of various exosome-based cancer biomarkers and the clinical significance of recent studies on FET-based biosensors applying them.

Peptide ligands for the universal purification of exosomes by affinity chromatography

Exosomes are gaining prominence as vectors for drug delivery, vaccination, and regenerative medicine. Owing to their surface biochemistry, which reflects the parent cell membrane, these nanoscale biologics feature low immunogenicity, tunable tissue tropism, and the ability to carry a variety of payloads across biological barriers. The heterogeneity of exosomes' size and composition, however, makes their purification challenging. Traditional techniques, like ultracentrifugation and filtration, afford low product yield and purity, and jeopardizes particle integrity. Affinity chromatography represents an excellent avenue for exosome purification. Yet, current affinity media rely on antibody ligands whose selectivity grants high product purity, but mandates the customization of adsorbents for exosomes with different surface biochemistry while their binding strength imposes elution conditions that may harm product's activity. Addressing these issues, this study introduces the first peptide affinity ligands for the universal purification of exosomes from recombinant feedstocks. The peptides were designed to (1) possess promiscuous biorecognition of exosome markers, without binding process-related contaminants and (2) elute the product under conditions that safeguard product stability. Selected ligands SNGFKKHI and TAHFKKKH demonstrated the ability to capture of exosomes secreted by 14 cell sources and purified exosomes derived from HEK293, PC3, MM1, U87, and COLO1 cells with yields of up to 80% and up-to 50-fold reduction of host cell proteins (HCPs) upon eluting with pH gradient from 7.4 to 10.5, recommended for exosome stability. SNGFKKHI-Toyopearl resin was finally employed in a two-step purification process to isolate exosomes from HEK293 cell fluids, affording a yield of 68% and reducing the titer of HCPs to 68 ng/mL. The biomolecular and morphological features of the isolated exosomes were confirmed by analytical chromatography, Western blot analysis, transmission electron microscopy, nanoparticle tracking analysis.

M2 macrophage exosome-derived Apoc1 promotes ferroptosis resistance in osteosarcoma by inhibiting ACSF2 deubiquitination

Osteosarcoma (OS) is the most common primary malignant tumor of bone. The aim of this study was to investigate the regulatory mechanisms of M2 macrophage exosomes (M2-Exos) in ferroptosis in OS. A mouse model was established to investigate the in vivo role of M2-Exos. We investigated their effects on ferroptosis in OS using erastin, a ferroptosis activator, and deferoxamine mesylate, an iron chelator. In vitro, we investigated whether the Apoc1/Acyl-CoA Synthetase Family Member 2 (ACSF2) axis mediates these effects, using shApoc1 and shACSF2. The mechanisms whereby Apoc1 regulates ACSF2 were examined using cyclohexanone, a protein synthesis inhibitor, and MG132, a proteasomal inhibitor. M2-Exos reversed the inhibitory effects of erastin on OS cells, thus enhancing their viability, migration, invasion, proliferation, and reducing ferroptosis. Apoc1 was highly expressed in M2-Exos, and interfering with this expression reversed the effects of M2-Exos on OS cells. ACSF2 mediated the effects of M2-Exos-derived Apoc1. Apoc1 interacted with ACSF2, which, in turn, interacted with USP40. Apoc1 overexpression increased ACSF2 ubiquitination, promoting its degradation, whereas USP40 overexpression inhibited ACSF2 ubiquitination and promoted its expression. Apoc1 overexpression inhibited ACSF2 binding to USP40. M2-Exos-derived Apoc1 promoted ferroptosis resistance by inhibiting USP40 binding to ACSF2 and promoting ACSF2 ubiquitination and degradation, thus enhancing OS development.

Heart rate variability and autonomic nervous system imbalance: Potential biomarkers and detectable hallmarks of aging and inflammaging

The most cutting-edge issue in the research on aging is the quest for biomarkers that transcend molecular and cellular domains to encompass organismal-level implications. We recently hypothesized the role of Autonomic Nervous System (ANS) imbalance in this context. Studies on ANS functions during aging highlighted an imbalance towards heightened sympathetic nervous system (SNS) activity, instigating a proinflammatory milieu, and attenuated parasympathetic nervous system (PNS) function, which exerts anti-inflammatory effects via the cholinergic anti-inflammatory pathway (CAP) and suppression of the hypothalamic-pituitary-adrenal (HPA) axis. This scenario strongly suggests that ANS imbalance can fuel inflammaging, now recognized as one of the most relevant risk factors for age-related disease development. Recent recommendations have increasingly highlighted the need for actionable strategies to improve the quality of life for older adults by identifying biomarkers that can be easily measured, even in asymptomatic individuals. We advocate for considering ANS imbalance as a biomarker of aging and inflammaging. Measures of ANS imbalance, such as heart rate variability (HRV), are relatively affordable, non-invasive, and cost-effective, making this hallmark easily diagnosable. HRV gains renewed significance within the aging research landscape, offering a tangible link between pathophysiological perturbations and age-related health outcomes.

Photobiomodulation associated with alginate-based engineered tissue on promoting chondrocytes-derived biological responses for cartilage regeneration

Articular cartilage is a connective tissue with limited self-healing potential, frequently affected by trauma and degenerative changes, leading to osteoarthritis. Photobiomodulation paired with engineered tissue can improve cartilage's poor intrinsic healing and overcome its restricted self-regeneration. In this study, alginate-based scaffolds were fabricated with varying concentrations of CaCl₂ to achieve optimal mechanical, biocompatible, and biodegradable properties. The fluence-dependence of near-infrared (NIR) laser irradiation (830 nm) on chondrocyte viability and proliferation was investigated in a 2D environment across fluences (2.5-10 J/cm2). Optimal conditions of 3 % w/v CaCl₂ and 5 J/cm2 were identified to construct alginate scaffolds and promote chondrocyte growth in 2D and 3D cultures. Single PBM (830 nm, 5 J/cm2) further exhibited a significant relative intensity of collagen type II immunostaining and stimulation of Col2a1 expression in 2D culture. Multiple PBM sessions (830 nm, 5 J/cm2) significantly enhanced chondrocyte proliferation and glycosaminoglycan production in alginate scaffolds, with a protocol of one session every four days being the most effective. Scanning electron microscopy revealed PBM-induced secretory granule formation, corresponding to a significant increase in extracellular vesicle release. Consequently, integrating PBM and alginate-based scaffolds is a promising technique for accelerating and optimizing cartilage regeneration, with potential application in tissue engineering.

Identification of ENO-1 positive extracellular vesicles as a circulating biomarker for monitoring of Ewing sarcoma

The lack of circulating biomarkers for tumor monitoring is a major problem in Ewing sarcoma management. The development of methods for accurate tumor monitoring is required, considering the high recurrence rate of drug-resistant Ewing sarcoma. Here, we describe a sensitive analytical technique for tumor monitoring of Ewing sarcoma by detecting circulating extracellular vesicles secreted from Ewing sarcoma cells. Proteomic analysis of Ewing sarcoma cell-derived extracellular vesicles identified 564 proteins prominently observed in extracellular vesicles from three Ewing sarcoma cell lines. Among these, CD99, SLC1A5, and ENO-1 were identified on extracellular vesicles purified from sera of patients with Ewing sarcoma before treatment but not on extracellular vesicles from those after treatment and healthy individuals. Notably, not only Ewing sarcoma-derived extracellular vesicles but also Ewing sarcoma cells demonstrated proteomic expression of CD99 and ENO-1 on their surface membranes. ENO-1+CD63+ extracellular vesicle detection was reduced after tumor resection while both CD99+CD63+ and ENO-1+CD63+ extracellular vesicles were detected in serum from Ewing sarcoma-bearing mice. Finally, the accuracy of liquid biopsy targeting these candidates was assessed using extracellular vesicles from the sera of patients with Ewing sarcoma. Elevated ENO-1+CD81+ extracellular vesicles in the serum of patients before treatments distinguished patients with Ewing sarcoma from healthy individuals with an area under the curve value of 0.92 (P < 0.001) and reflected the tumor burden in patients with Ewing sarcoma during multidisciplinary treatments. Collectively, circulating ENO-1+CD81+ extracellular vesicle detection could represent a novel tool for tumor monitoring of Ewing sarcoma.

Prostate cancer theragnostics biomarkers: An update

Biomarkers are molecules such as proteins, genes, or other substances that may be tested to determine the stage of the tumor in a patient. The role of prostate cancer biomarkers is pivotal and the combination of prostate cancer immunotherapy with efficient biomarkers has emerged as a beneficial treatment strategy and its use has increased rapidly. The two primary objectives of this current prostate cancer early detection programs were recognizing non-symptomatic individuals with prostate cancer requiring prostatic core biopsy and identifying men with prostate cancer who might benefit from definitive medical treatment. The progress that has been made so far in the identification of the biomarkers that can be used for the classification, prediction and prognostication of prostate cancer, and as major targets for its clinical intervention has been well summarized in this review.

Unraveling the nexus of oxidative stress, ocular diseases, and small extracellular vesicles to identify novel glaucoma biomarkers through in-depth proteomics

Chronic ocular pathologies such as cataracts and glaucoma are emerging as an important problem for public health due to the changes in lifestyle and longevity. These age-related ocular diseases are largely mediated by oxidative stress. Small extracellular vesicles (sEVs) are involved in cell-to-cell communication and transport. There is an increasing interest about the function of small extracellular vesicles (sEVs) in the eye. However, the proteome content and characterization of sEVs released by ocular cells under pathological conditions are not yet well known. Here, we aimed to analyze the protein profile of sEVs and the intracellular protein content from two ocular cell lines (lens epithelial cells and retinal ganglion cells) exposed to oxidative stress to identify altered proteins that could serve as potential diagnostic biomarkers. The protein content was analyzed by quantitative mass spectrometry-based proteomics. Validation was performed by WB and ELISA using cell extracts and aqueous humor from cataract and glaucoma patients. After data analysis, 176 and 7 dysregulated proteins with an expression ratio≥1.5 were identified in lens epithelial cells' protein extract and sEVs, respectively, upon oxidative stress induction. In retinal ganglion cells, oxidative stress induction resulted in the dysregulation of 1033 proteins in cell extracts and 9 proteins in sEVs. In addition, by WB and ELISA, the dysregulation of proteins was mostly confirmed in aqueous humor samples from cataract or glaucoma patients in comparison to ICL individuals, with RAD23B showing high glaucoma diagnostic ability. Importantly, this work expands the knowledge of the proteome characterization of cataracts and glaucoma and provides new potential diagnostic glaucoma biomarkers.

Promotion of osteochondral repair through immune microenvironment regulation and activation of endogenous chondrogenesis via the release of apoptotic vesicles from donor MSCs

Utilizing transplanted human umbilical cord mesenchymal stem cells (HUMSCs) for cartilage defects yielded advanced tissue regeneration, but the underlying mechanism remain elucidated. Early after HUMSCs delivery to the defects, we observed substantial apoptosis. The released apoptotic vesicles (apoVs) of HUMSCs promoted cartilage regeneration by alleviating the chondro-immune microenvironment. ApoVs triggered M2 polarization in macrophages while simultaneously facilitating the chondrogenic differentiation of endogenous MSCs. Mechanistically, in macrophages, miR-100-5p delivered by apoVs activated the MAPK/ERK signaling pathway to promote M2 polarization. In MSCs, let-7i-5p delivered by apoVs promoted chondrogenic differentiation by targeting the eEF2K/p38 MAPK axis. Consequently, a cell-free cartilage regeneration strategy using apoVs combined with a decellularized cartilage extracellular matrix (DCM) scaffold effectively promoted the regeneration of osteochondral defects. Overall, new mechanisms of cartilage regeneration by transplanted MSCs were unconcealed in this study. Moreover, we provided a novel experimental basis for cell-free tissue engineering-based cartilage regeneration utilizing apoVs.

Autophagy in drusen biogenesis secondary to age-related macular degeneration

Age-related macular degeneration (AMD) is an emerging cause of blindness in aged people worldwide. One of the key signs of AMD is the degeneration of the retinal pigment epithelium (RPE), which is indispensable for the maintenance of the adjacent photoreceptors. Because of impaired energy metabolism resulting from constant light exposure, hypoxia, and oxidative stress, accumulation of drusen in AMD-affected eyes is observed. Drusen contain damaged cellular proteins, lipoprotein particles, lipids and carbohydrates and they are related to impaired protein clearance, inflammation, and extracellular matrix modification. When autophagy, a major cellular proteostasis pathway, is impaired, the accumulations of intracellular lipofuscin and extracellular drusen are detected. As these aggregates grow over time, they finally cause the disorganisation and destruction of the RPE and photoreceptors leading to visual loss. In this review, the role of autophagy in drusen biogenesis is discussed since impairment in removing cellular waste in RPE cells plays a key role in AMD progression. In the future, means which improve intracellular clearance might be of use in AMD therapy to slow the progression of drusen formation.

Low pinocytic brain endothelial cells primarily utilize membrane fusion to internalize extracellular vesicles

Extracellular vesicles (EVs) are an emerging class of drug carriers and are primarily reported to be internalized into recipient cells via a combination of endocytic routes such as clathrin-mediated, caveolae-mediated and macropinocytosis pathways. In this work, (1) we investigated potential effects of homotypic vs. heterotypic interactions by studying the cellular uptake of homologous EVs (EV donor cells and recipient cells of the same type) vs. heterologous EVs (EV donor cells and recipient cells of different types) and (2) determined the route of EV internalization into low pinocytic/hard-to-deliver cell models such as brain endothelial cells (BECs). Homotypic interactions led to a greater extent of uptake into the recipient BECs compared to heterotypic interactions. However, we did not see a complete reduction in EV uptake into recipient BECs when endocytic pathways were blocked using pharmacological inhibitors and our findings from a R18-based fusion assay suggest that EVs primarily use membrane fusion to enter low-pinocytic recipient BECs instead of relying on endocytosis. Lipophilic PKH67 dye-labeled EVs but not intravesicular esterase-activated calcein ester-labeled EVs severely reduced particle uptake into BECs while phagocytic macrophages internalized EVs labeled with both dyes to comparable extents. Our results also highlight the importance of carefully choosing labeling dye chemistry to study EV uptake, especially in the case of low pinocytic cells such as BECs.

Augmenting osteoporotic bone regeneration through a hydrogel-based rejuvenating microenvironment

Osteoporotic bone defects pose a significant challenge for bone regeneration as they exhibit impaired healing capacity and delayed healing period. To address this issue, this study introduces a hydrogel that creates a rejuvenating microenvironment, thereby facilitating efficient bone repair during the initial two weeks following bone defect surgery. The hydrogel, named GelHFS, was created through host-guest polymerization of gelatin and acrylated β-cyclodextrin. Incorporation of the human fetal mesenchymal stem cell secretome (HFS) formed GelHFS hydrogel aimed at mimicking a rejuvenated stem cell niche. Our results demonstrated that GelHFS hydrogel promotes cell stellate spreading and osteogenic differentiation via integrin β1-induced focal adhesion pathway. Implantation of GelHFS hydrogel in an osteoporotic bone defect rat model recruited endogenous integrin β1-expressing cells and enhanced new bone formation and bone strength. Our findings reveal that GelHFS hydrogel provides a rejuvenating niche for endogenous MSCs and enhances bone regeneration in osteoporotic bone defect. These findings highlight the potential of GelHFS hydrogel as an effective therapeutic strategy for addressing challenging bone healing such as osteoporotic bone regeneration.

Addressable scanning multifocal structured illumination microscopy using acousto-optic deflectors

Multifocal structured illumination microscopy (MSIM) is a popular super-resolution imaging technique known for its good probe compatibility, low laser power requirements, and improved imaging depth, making it widely applicable in biomedical research. However, the speed of MSIM imaging is typically constrained by the approaches employed to generate and scan the laser foci across the sample. In this study, we propose a flexible two-photon excitation MSIM method using a pair of acousto-optic deflectors. By adopting addressable scanning (AS) and synchronized capturing, MSIM super-resolution imaging can be performed in multiple discrete regions of interest (ROIs) within the field of view. Notably, this AS-MSIM scheme not only enhances the speed of MSIM imaging but also alleviates photobleaching and phototoxicity to biological samples. We demonstrate its potential by achieving super-resolution imaging of selected mitochondria within cells at a frame rate of 4 Hz. Furthermore, we deliberate the possibility of even faster imaging.

Exosome-mediated renal protection: Halting the progression of fibrosis

Renal fibrosis is a complex and multifactorial process that involves inflammation, cell proliferation, collagen, and fibronectin deposition in the kidney, ultimately leading to chronic kidney disease and even end-stage renal disease. The main goal of treatment is to slow down or halt the progression of fibrosis and to improve or preserve kidney function. Despite significant progress made in understanding the underlying mechanisms of renal fibrosis, current therapies have limited renal protection as the disease progresses. Exosomes derived from stem cells are a newer area of research for the treatment of renal fibrosis. Exosomes as nano-sized extracellular vesicles carry proteins, lipids, and nucleic acids, which can be taken up by local or distant cells, serving as mediators of intercellular communication and as drug delivery vehicles. Exosomes deliver molecules that reduce inflammation, renal fibrosis and extracellular matrix protein production, and promote tissue regeneration in animal models of kidney disease. Additionally, they have several advantages over stem cells, such as being non-immunogenic, having low risk of tumor formation, and being easier to produce and store. This review describes the use of natural and engineered exosomes containing therapeutic agents capable of mediating anti-inflammatory and anti-fibrotic processes during both acute kidney injury and chronic kidney disease. Exosome-based therapies will be compared with stem cell-based treatments for tissue regeneration, with a focus on renal protection. Finally, future directions and strategies for improving the therapeutic efficacy of exosomes are discussed.

Human placental mesenchymal stromal cells alleviate intestinal oxidative damage in mice with graft-versus-host disease via CD73/adenosine/PI3K/Akt/GSK-3β axis

BACKGROUND

Intestinal damage is a common and serious complication in patients with graft-versus-host disease (GVHD). Human placental mesenchymal stromal cells (hPMSCs) ameliorate GVHD tissue damage by exerting anti-oxidative effects; however, the underlying mechanisms remain not fully clear.

METHODS

A GVHD mouse model and tumor necrosis factor-α (TNF-α)-stimulated human colon epithelial cell lines NCM460 and HT-29 cells were used to investigate the mechanisms of hPMSCs alleviating GVHD-induced intestinal oxidative damage.

RESULTS

hPMSCs reduced TNF-α concentrations and the number of CD3+TNF-α+ T-cells, which were negatively correlated with the expression of claudin-1, occludin, and ZO-1, through CD73 in the colon tissue of GVHD mice. Meanwhile, hPMSCs reduced the mean fluorescence intensity (MFI) of reactive oxygen species (ROS) and the concentration of malondialdehyde (MDA), promoted superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) activities, as well as claudin-1, occludin, and ZO-1 expression, in colonic epithelial cells of GVHD mice and TNF-α-stimulated cells via CD73. Moreover, hPMSCs upregulated adenosine (ADO) concentrations in GVHD mice and TNF-α-stimulated cells and mitigated the loss of tight junction proteins via the CD73/ADO/ADO receptors. Further analysis showed that hPMSCs diminished Fyn expression and enhanced Nrf2, GCLC, and HO-1 expression in both TNF-α-stimulated cells and colonic epithelial cells of GVHD mice by activating PI3K/Akt/GSK-3β pathway.

CONCLUSIONS

The results suggested that hPMSC-mediated redox metabolism balance and promoted tight junction protein expression were achieved via CD73/ADO/PI3K/Akt/GSK-3β/Fyn/Nrf2 axis, by which alleviating intestinal oxidative injury in GVHD mice.

Bioactive polysaccharides mediate ferroptosis to modulate tumor immunotherapy

Polysaccharides from diverse origins exhibit notable bioactivities, particularly their capacity to exert antitumor and immune-enhancing effects. Concurrently, ferroptosis emerges as a distinctive form of regulated cell death characterized by iron-dependent lipid peroxidation, potentially influencing the demise of specific tumor cells and organismal homeostasis. Recent scholarly attention has increasingly focused on utilizing polysaccharides to modulate tumor cell ferroptosis and manipulate cellular immune responses. This article provides an in-depth analysis of contemporary research concerning using polysaccharides to augment antitumor immunity and combat malignancies. Central to our discourse is examining the pivotal role of polysaccharides in mediating ferroptosis, bolstering immune surveillance, and elucidating the interplay between polysaccharides and antitumor immunity. Furthermore, a comprehensive synthesis of the multifaceted roles of polysaccharides in antitumor and immunomodulatory contexts is provided. Recent advances in understanding how polysaccharides enhance immune function by inducing ferroptosis cell death are explained. Lastly, unresolved inquiries are outlined, and potential avenues for future research are proposed, focusing on the translational applications of polysaccharides in antitumor immunotherapy.

COX-2/PTGS2-targeted herbal-derived oligonucleotide drug HQi-sRNA-2 was effective in spontaneous mouse lung cancer model

In 2020, the number of deaths caused by lung cancer worldwide reached 1,796,144, making it the leading cause of cancer-related deaths. Cyclooxygenase-2/prostaglandin endoperoxide synthase 2 (COX-2/PTGS2) is overexpressed in lung cancer, which promotes tumor proliferation, invasion, angiogenesis, and resistance to apoptosis. Here, we report that the oligonucleotide drug HQi-sRNA-2 from Traditional Chinese Medicine Huangqin targeting COX-2/PTGS2 significantly inhibited proliferation, migration, and invasion and induced apoptosis in the human lung cancer cell line NCI-H460. Oral delivery of HQi-sRNA-2 bencaosomes prolonged survival, reduced tumor burden, and maintained weight in a spontaneous mouse lung cancer model. Compared with paclitaxel, HQi-sRNA-2 may be less toxic and have approximately equal efficacy in reducing tumor burden. Our previous studies reported that herbal small RNAs (sRNAs) are functional medical components. Our data suggest that sphingosine (d18:1)-HQi-sRNA-2 bencaosomes, targeting COX-2/PTGS2 and downregulating the PI3K and AKT signaling pathways, may provide novel therapeutics for lung cancer.

Reduced microRNA-744 expression in mast cell-derived exosomes triggers epithelial cell ferroptosis in acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is a critical disorder characterized by immune-related damage to epithelial cells; however, its underlying mechanism remains elusive. This study investigated the effects of alterations in microRNA (miRNA) expression in mast cell-derived exosomes on human bronchial epithelial (HBE) cells and ARDS development in cellular and mouse models challenged with lipopolysaccharide. Lipopolysaccharide-treated mast cell-derived exosomes reduced glutathione peroxidase 4 (GPX4) expression and increased long-chain acyl-CoA synthetase 4 (ACSL4), 15-lipoxygenase (ALOX15), and inflammatory mediator levels in HBE cells. miRNA sequencing revealed a reduction in mast cell-derived exosomal miR-744 levels, which was associated with the regulation of ACSL4, ALOX15, and GPX4 expression. This downregulation of exosomal miR-744 expression reduced miR-744 levels and promoted ferroptosis in HBE cells, whereas the experimental upregulation of miR-744 reversed these adverse effects. Down-regulation of miR-744 induced the expression of markers for ferroptosis and inflammation in HBE cells and promoted pulmonary ferroptosis, inflammation, and injury in LPS-stimulated mice. In vivo, treatment with ACSL4, ALOX15, and GPX4 inhibitors mitigated these effects, and experimental miR-744 expression rescued the lipopolysaccharide-induced changes in HBE cells and mouse lungs. Notably, miR-744 levels were reduced in the plasma and exosomes of patients with ARDS. We concluded that decreased mast cell-derived exosomal miR-744 levels trigger epithelial cell ferroptosis, promoting lung inflammation and damage in ARDS. This study provides new mechanistic insights into the development and sustained pulmonary damage associated with ARDS and highlights potential therapeutic strategies.

Exosomes on the development and progression of renal fibrosis

Renal fibrosis is a prevalent pathological alteration that occurs throughout the progression of primary and secondary renal disorders towards end-stage renal disease. As a complex and irreversible pathophysiological phenomenon, it includes a sequence of intricate regulatory processes at the molecular and cellular levels. Exosomes are a distinct category of extracellular vesicles that play a crucial role in facilitating intercellular communication. Multiple pathways are regulated by exosomes produced by various cell types, including tubular epithelial cells and mesenchymal stem cells, in the context of renal fibrosis. Furthermore, research has shown that exosomes present in bodily fluids, including urine and blood, may be indicators of renal fibrosis. However, the regulatory mechanism of exosomes in renal fibrosis has not been fully elucidated. This article reviewed and analysed the various mechanisms by which exosomes regulate renal fibrosis, which may provide new ideas for further study of the pathophysiological process of renal fibrosis and targeted treatment of renal fibrosis with exosomes.

Extraction of redox extracellular vesicles using exclusion-based sample preparation

Studying specific subpopulations of cancer-derived extracellular vesicles (EVs) could help reveal their role in cancer progression. In cancer, an increase in reactive oxygen species (ROS) happens which results in lipid peroxidation with a major product of 4-hydroxynonenal (HNE). Adduction by HNE causes alteration to the structure of proteins, leading to loss of function. Blebbing of EVs carrying these HNE-adducted proteins as a cargo or carrying HNE-adducted on EV membrane are methods for clearing these molecules by the cells. We have referred to these EVs as Redox EVs. Here, we utilize a surface tension-mediated extraction process, termed exclusion-based sample preparation (ESP), for the rapid and efficient isolation of intact Redox EVs, from a mixed population of EVs derived from human glioblastoma cell line LN18. After optimizing different parameters, two populations of EVs were analyzed, those isolated from the sample (Redox EVs) and those remaining in the original sample (Remaining EVs). Electron microscopic imaging was used to confirm the presence of HNE adducts on the outer leaflet of Redox EVs. Moreover, the population of HNE-adducted Redox EVs shows significantly different characteristics to those of Remaining EVs including smaller size EVs and a more negative zeta potential EVs. We further treated glioblastoma cells (LN18), radiation-resistant glioblastoma cells (RR-LN18), and normal human astrocytes (NHA) with both Remaining and Redox EV populations. Our results indicate that Redox EVs promote the growth of glioblastoma cells, likely through the production of H2O2, and cause injury to normal astrocytes. In contrast, Remaining EVs have minimal impact on the viability of both glioblastoma cells and NHA cells. Thus, isolating a subpopulation of EVs employing ESP-based immunoaffinity could pave the way for a deeper mechanistic understanding of how subtypes of EVs, such as those containing HNE-adducted proteins, induce biological changes in the cells that take up these EVs.

Exosomes for CRISPR-Cas9 Delivery: The Cutting Edge in Genome Editing

Gene mutation correction was challenging until the discovery of clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated protein (Cas). CRISPR is a new era for genome modification, and this technology has bypassed the limitations of previous methods such as zinc-finger nuclease and transcription activator-like effector nuclease. Currently, this method is becoming the method of choice for gene-editing purposes, especially therapeutic gene editing in diseases such as cardiovascular, neurological, renal, genetic, optical, and stem cell, as well as blood disorders and muscular degeneration. However, finding the optimum delivery system capable of carrying this large complex persists as the main challenge of this technology. Therefore, it would be ideal if the delivery vehicle could direct the introduction of editing functions to specific cells in a multicellular organism. Exosomes are membrane-bound vesicles with high biocompatibility and low immunogenicity; they offer the best and most reliable way to fill the CRISPR/Cas9 system delivery gap. This review presents the current evidence on the molecular mechanisms and challenges of CRISPR/Cas9-mediated genome modification. Also, the role of CRISPR/Cas9 in the development of treatment and diagnosis of numerous disorders, from malignancies to viral infections, has been discussed. Lastly, the focus is on new advances in exosome-delivery technologies that may play a role in CRISPR/Cas9 delivery for future clinical settings.

New avenues for cancer immunotherapy: Cell-mediated drug delivery systems

Cancer research has become increasingly complex over the past few decades as knowledge of the heterogeneity of cancer cells, their proliferative ability, and their tumor microenvironments has become available. Although conventional therapies remain the most compelling option for cancer treatment to date, immunotherapy is a promising way to harness natural immune defenses to target and kill cancer cells. Cell-mediated drug delivery systems (CDDSs) have been an active line of research for enhancing the therapeutic efficacy and specificity of cancer immunotherapy. These systems can be tailored to different types of immune cells, allowing immune evasion and accumulation in the tumor microenvironment. By enabling the targeted delivery of therapeutic agents such as immune stimulants, cytokines, antibodies, and antigens, CDDSs have improved the survival of some patients with cancer. This review summarizes the research status of CDDSs, with a focus on their underlying mechanisms of action, biology, and clinical applications. We also discuss opportunities and challenges for implementation of CDDSs into mainstream cancer immunotherapy.

Anatomic and functional evidence for renal autonomic innervation in normotensive and hypertensive rats

Renal denervation (RDN) has been used for treating resistant hypertension. A few recent studies have shown vagal innervation of kidneys causing confusion. This study aimed to provide anatomical and functional evidence for renal autonomic innervation. Experiments were performed in male Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR). Pseudorabies virus (PRV) in the paraventricular nucleus and rostral ventrolateral medulla was prevented by bilateral RDN, but not subdiaphragmatic vagotomy. PRV did not appear in the dorsal motor nucleus of the vagus and nucleus tractus solitarii 72 h after renal injection of PRV. Adrenergic fibers were approximately seven times more than cholinergic fibers in the main renal artery (MRA) and its first (1RA) and second grade (2RA) branches. Adrenergic fibers in 1RA were more than those in MRA and 2RA. Tyrosine hydroxylase immunoreactivity in these arteries was higher in SHR than in WKY. Norepinephrine (NE) increased and α-receptor antagonist reduced vascular ring tension of renal arteries. The effect of NE was greater in 1RA and 2RA than in MRA, which was prevented by α-receptor antagonist. Acetylcholine (ACh) or blockage of β-receptors, M receptors, or N receptors had no significant effects on vascular ring tension and the effect of NE. Renal blood flow was reduced by electrical stimulation of renal nerves but not affected by stimulation of the subdiaphragmatic vagus. These results provide anatomical and functional evidence that kidneys are innervated and renal blood flow is regulated by renal sympathetic nerves rather than the vagus. Renal vasoconstriction is regulated by NE and adrenergic fibers rather than ACh or cholinergic fibers in WKY and SHR.NEW & NOTEWORTHY Kidneys are innervated by renal nerves rather than the vagus. Adrenergic fibers in renal arteries are about seven times more than cholinergic fibers. Renal vasoconstriction is regulated by norepinephrine and adrenergic fibers rather than acetylcholine or cholinergic fibers. Renal blood flow is regulated by renal sympathetic nerves and is not affected by the vagus. These findings provide anatomical and functional evidence for renal autonomic innervation in normotensive and hypertensive rats.

Study of the uptake mechanism of two small extracellular vesicle subtypes by granulosa cells

As a new mechanism of intercellular communication, the uptake of extracellular vesicles (EVs) by receptor cells has become a hot topic in the field. Previously, research on the uptake of EVs has focused on the mechanism of small EVs (sEVs, also known as exosomes). As sEVs represent a mixed heterogeneous population, the issue of whether there are different uptake mechanisms for different subsets of sEVs by recipient cells urgently need to be addressed. There are EVs in follicular fluid, which play an important role in the communication between follicular cells and the development of oocytes. Previously, we isolated two subtypes of sEVs in follicular fluid: low density-sEVs (LD-sEVs) and high density-sEVs (HD-sEVs). The current study aimed to explore the uptake characteristics of these two subtypes of sEVs by granulosa cells. First, PKH67 was used to label the two sEVs subtypes, and we observed their uptake by granulosa cells using confocal microscopy and flow cytometry. We then explored the specific mechanisms underlying uptake of these two sEV subtypes by granulosa cells using specific inhibitors and RNA interference. The results showed that granulosa cells took up both kinds of sEVs through a clathrin-independent pathway. In addition to requiring caveolin, cholesterol, and Na+/H+ exchange, the uptake of HD-sEVs also depended on the activity of tyrosine kinase and phosphoinositide 3-kinase. A better understanding of the mechanism of granulosa cell uptake of different subtypes of sEVs in follicular fluid is of considerable significance leading to more accurate use of EVs for targeted treatment of infertility and other related diseases.

A novel multiplexed immunoassay for surface-exposed proteins in plasma extracellular vesicles

Small membranous extracellular vesicles (EV) incorporate proteins and nucleic acids from the parent cell. Proteins exposed on EV surface are dictated by cellular origin and biogenesis pathway. To better understand the EV origin and function, it is important to develop methods that reveal surface protein composition of heterogeneous EV populations in culture supernatants and in biofluids. Tetraspanins CD9, CD63, and CD81 are common and abundant EV markers. However, their relative enrichment (profile) on EVs of specific cellular origins is not fully elucidated. We introduce LuminEV, a novel version of the Luminex assay for the multiplexed analysis of EV surface proteins. Optimized LuminEV reagents enable direct, specific, and sensitive measurements of EV markers in biofluids and in culture supernatants, bypassing EV isolation step. LuminEV assay for CD9, CD63, and CD81 was validated by comparing simplex and multiplex measurements, establishing linearity, spike-in recovery, inter- and intra-assay precision, and reproducibility between operators. LuminEV measurements of CD9, CD63, and CD81 in conditioned media from 15 cell lines revealed strong variations between cell types and showed high sensitivity, which enabled EV detection without prior concentration. Using tetraspanin levels as a readout, we noted suppression and induction of EV release from the cultured cells by GW6869 and monensin. Measurement of EV CD9, CD63, and CD81 in blood plasma from 70 disease-free donors showed respective abundance of 72, 16, and 12%. CD63 displayed weak, albeit significant, negative correlation with age and was slightly lower in female samples. The assay was then used to detect cell type-specific EV surface markers, including CD235a (erythrocytes), GAP43 (neurons), and CD68 (macrophages), and to detect differences in tetraspanin profiles between healthy and diseased donors. In summary, LuminEV offers robust and sensitive approach for multiplexed assessment of EV surface proteins, to facilitate the research into EV biology, biomarker, and therapeutic applications.

Cell-free nucleic acid fragmentomics: A non-invasive window into cellular epigenomes

Clinical genomic profiling of cell-free nucleic acids (e.g. cell-free DNA or cfDNA) from blood and other body fluids has ushered in a new era in non-invasive diagnostics and treatment monitoring strategies for health conditions and diseases such as cancer. Genomic analysis of cfDNAs not only identifies disease-associated mutations, but emerging findings suggest that structural, topological, and fragmentation characteristics of cfDNAs reveal crucial information about the location of source tissues, their epigenomes, and other clinically relevant characteristics, leading to the burgeoning field of fragmentomics. The field has seen rapid developments in computational and genomics methodologies for conducting large-scale studies on health conditions and diseases - that have led to fundamental, mechanistic discoveries as well as translational applications. Several recent studies have shown the clinical utilities of the cfDNA fragmentomics technique which has the potential to be effective for early disease diagnosis, determining treatment outcomes, and risk-free continuous patient monitoring in a non-invasive manner. In this article, we outline recent developments in computational genomic methodologies and analysis strategies, as well as the emerging insights from cfNA fragmentomics. We conclude by highlighting the current challenges and opportunities.

Murine exosomal miR-30a aggravates cardiac function after acute myocardial infarction via regulating cell fate of cardiomyocytes and cardiac resident macrophages

After acute myocardial infarction (AMI), intercellular communication is crucial for maintaining cardiac homeostasis and patient survival. Exosomes secreted by cardiomyocytes serve as carriers for transporting microRNA(miRNAs), participating in intercellular signaling and the regulation of cardiac function. This study aims to investigate the role of exosomal microRNA-30a(miR-30a) during AMI and its underlying mechanisms. AMI was induced by permanent ligation of the left anterior descending (LAD) artery in C57BL/6 mice. The expression of miR-30a in mice was respectively enhanced and inhibited by administering agomiR-30a and antagomiR-30a. Using HL-1 cardiomyocytes and RAW264.7 macrophages for in vitro experiments, HL-1 cardiomyocytes were cultured under hypoxic conditions to induce ischemic injury. Following isolation and injection of exosomals, a variety of validation methods were utilized to assess the expression of miR-30a, and investigate the effects of enriched exosomal miR-30a on the state of cardiomyocytes. After AMI, the level of exosomal miR-30a in the serum of mice significantly increased and was highly enriched in cardiac tissue. Cardiomyocytes treated with agomiR-30a and miR-30a-enriched exosomes exhibited inhibition of cell autophagy, increased cell apoptosis, mice showed an larger myocardial infarct area and poorer cardiac function. Exosomes released from hypoxic cardiomyocytes transferred miR-30a to cardiac resident macrophages, promoting the polarization into pro-inflammatory M1 macrophages. In conclusion, murine exosomal miR-30a exacerbates cardiac dysfunction post-AMI by disrupting the autophagy-apoptosis balance in cardiomyocytes and polarizing cardiac resident macrophages into pro-inflammatory M1 macrophages. Modulating the expression of miR-30a may reduce cardiac damage following AMI, and targeting exosomal miR-30a could be a potential therapeutic approach for AMI.

Molecular mechanisms and targeted therapy for the metastasis of prostate cancer to the bones (Review)

The incidence of prostate cancer (PCa) is increasing, making it one of the prevalent malignancies among men. Metastasis of PCa to the bones poses the greatest danger to patients, potentially resulting in treatment ineffectiveness and mortality. At present, the management of patients with bone metastasis focuses primarily on providing palliative care. Research has indicated that the spread of PCa to the bones occurs through the participation of numerous molecules and their respective pathways. Gaining knowledge regarding the molecular processes involved in bone metastasis may result in the development of innovative and well‑tolerated therapies, ultimately enhancing the quality of life and prognosis of patients. The present article provides the latest overview of the molecular mechanisms involved in the formation of bone metastatic tumors from PCa. Additionally, the clinical outcomes of targeted drug therapies for bone metastasis are thoroughly analyzed. Finally, the benefits and difficulties of targeted therapy for bone metastasis of PCa are discussed, aiming to offer fresh perspectives for treatment.

Chondroitin sulfate-based microneedles for transdermal delivery of stem cell-derived extracellular vesicles to treat rheumatoid arthritis

For the non-invasive treatment of rheumatoid arthritis (RA), a chondroitin sulfate C (CSC)-based dissolving microneedles (cMN) was prepared to deliver human adipose stem cell-derived extracellular vesicles (hASC-EV) into inflamed joints. Owing to their anti-inflammatory function, the hASC-EV-bearing cMN (EV@cMN) significantly suppressed activated fibroblast-like synoviocytes (aFLS) and M1 macrophages (M1), which are responsible for the progression of RA. In addition, EV@cMN facilitated the chondrogenic differentiation of bone marrow-derived stem cells. In mice with collagen-induced arthritis, EV@cMN efficiently delivered both hASC-EV and CSC to inflamed joints. Interestingly, pro-inflammatory cytokines in the inflamed joints were remarkably downregulated by the synergistic effect of CSC and hASC-EV. Consequently, as judged from the overall clinical score and joint swelling, EV@cMN showed an outstanding therapeutic effect, even comparable to the wild-type mice, without significant adverse effects. Overall, EV@cMN might have therapeutic potential for RA by efficiently delivering CSC and hASC-EV into the inflamed joints in a non-invasive manner.

Exploring the roles and molecular mechanisms of RNA binding proteins in the sorting of noncoding RNAs into exosomes during tumor progression

BACKGROUND

RNA binding proteins (RBPs) play a role in sorting non-coding RNAs (ncRNAs) into exosomes. These ncRNAs, carried by exosomes, are involved in regulating various aspects of tumor progression, including metastasis, angiogenesis, control of the tumor microenvironment, and drug resistance. Recent studies have emphasized the importance of the RBP-ncRNA-exosome mechanism in tumor regulation.

AIM OF REVIEW

This comprehensive review aims to explore the RBP-ncRNA-exosome mechanism and its influence on tumor development. By understanding this intricate mechanism provides novel insights into tumor regulation and may lead to innovative treatment strategies in the future.

KEY SCIENTIFIC CONCEPTS OF REVIEW

The review discusses the formation of exosomes and the complex relationships among RBPs, ncRNAs, and exosomes. The RBP-ncRNA-exosome mechanism is shown to affect various aspects of tumor biology, including metastasis, multidrug resistance, angiogenesis, the immunosuppressive microenvironment, and tumor progression. Tumor development relies on the transmission of information between cells, with RBPs selectively mediating sorting of ncRNAs into exosomes through various mechanisms, which in turn carry ncRNAs to regulate RBPs. The review also provides an overview of potential therapeutic strategies, such as targeted drug discovery and genetic engineering for modifying therapeutic exosomes, which hold great promise for improving cancer treatment.

Mitochondrial Extracellular Vesicles (mitoEVs): Emerging mediators of cell-to-cell communication in health, aging and age-related diseases

Mitochondria are metabolic and signalling hubs that integrate a plethora of interconnected processes to maintain cell homeostasis. They are also dormant mediators of inflammation and cell death, and with aging damages affecting mitochondria gradually accumulate, resulting in the manifestation of age-associated disorders. In addition to coordinate multiple intracellular functions, mitochondria mediate intercellular and inter-organ cross talk in different physiological and stress conditions. To fulfil this task, mitochondrial signalling has evolved distinct and complex conventional and unconventional routes of horizontal/vertical mitochondrial transfer. In this regard, great interest has been focused on the ability of extracellular vesicles (EVs), such as exosomes and microvesicles, to carry selected mitochondrial cargoes to target cells, in response to internal and external cues. Over the past years, the field of mitochondrial EVs (mitoEVs) has grown exponentially, revealing unexpected heterogeneity of these structures associated with an ever-expanding mitochondrial function, though the full extent of the underlying mechanisms is far from being elucidated. Therefore, emerging subsets of EVs encompass exophers, migrasomes, mitophers, mitovesicles, and mitolysosomes that can act locally or over long-distances to restore mitochondrial homeostasis and cell functionality, or to amplify disease. This review provides a comprehensive overview of our current understanding of the biology and trafficking of MitoEVs in different physiological and pathological conditions. Additionally, a specific focus on the role of mitoEVs in aging and the onset and progression of different age-related diseases is discussed.