Isolation of mitochondria-derived mitovesicles and subpopulations of microvesicles and exosomes from brain tissues

Mitochondrial transplantation: a promising strategy for the treatment of retinal degenerative diseases

The retina, a crucial neural tissue, is responsible for transforming light signals into visual information, a process that necessitates a significant amount of energy. Mitochondria, the primary powerhouses of the cell, play an integral role in retinal physiology by fulfilling the high-energy requirements of photoreceptors and secondary neurons through oxidative phosphorylation. In a healthy state, mitochondria ensure proper visual function by facilitating efficient conversion and transduction of visual signals. However, in retinal degenerative diseases, mitochondrial dysfunction significantly contributes to disease progression, involving a decline in membrane potential, the occurrence of DNA mutations, increased oxidative stress, and imbalances in quality-control mechanisms. These abnormalities lead to an inadequate energy supply, the exacerbation of oxidative damage, and the activation of cell death pathways, ultimately resulting in neuronal injury and dysfunction in the retina. Mitochondrial transplantation has emerged as a promising strategy for addressing these challenges. This procedure aims to restore metabolic activity and function in compromised cells through the introduction of healthy mitochondria, thereby enhancing the cellular energy production capacity and offering new strategies for the treatment of retinal degenerative diseases. Although mitochondrial transplantation presents operational and safety challenges that require further investigation, it has demonstrated potential for reviving the vitality of retinal neurons. This review offers a comprehensive examination of the principles and techniques underlying mitochondrial transplantation and its prospects for application in retinal degenerative diseases, while also delving into the associated technical and safety challenges, thereby providing references and insights for future research and treatment.

Utilizing engineered extracellular vesicles as delivery vectors in the management of ischemic stroke: a special outlook on mitochondrial delivery

Ischemic stroke is a secondary cause of mortality worldwide, imposing considerable medical and economic burdens on society. Extracellular vesicles, serving as natural nano-carriers for drug delivery, exhibit excellent biocompatibility in vivo and have significant advantages in the management of ischemic stroke. However, the uncertain distribution and rapid clearance of extracellular vesicles impede their delivery efficiency. By utilizing membrane decoration or by encapsulating therapeutic cargo within extracellular vesicles, their delivery efficacy may be greatly improved. Furthermore, previous studies have indicated that microvesicles, a subset of large-sized extracellular vesicles, can transport mitochondria to neighboring cells, thereby aiding in the restoration of mitochondrial function post-ischemic stroke. Small extracellular vesicles have also demonstrated the capability to transfer mitochondrial components, such as proteins or deoxyribonucleic acid, or their sub-components, for extracellular vesicle-based ischemic stroke therapy. In this review, we undertake a comparative analysis of the isolation techniques employed for extracellular vesicles and present an overview of the current dominant extracellular vesicle modification methodologies. Given the complex facets of treating ischemic stroke, we also delineate various extracellular vesicle modification approaches which are suited to different facets of the treatment process. Moreover, given the burgeoning interest in mitochondrial delivery, we delved into the feasibility and existing research findings on the transportation of mitochondrial fractions or intact mitochondria through small extracellular vesicles and microvesicles to offer a fresh perspective on ischemic stroke therapy.

Exomeres and supermeres: Current advances and perspectives

Recent studies have revealed a great diversity and complexity in extracellular vesicles and particles (EVPs). The developments in techniques and the growing awareness of the particle heterogeneity have spurred active research on new particle subsets. Latest discoveries highlighted unique features and roles of non-vesicular extracellular nanoparticles (NVEPs) as promising biomarkers and targets for diseases. These nanoparticles are distinct from extracellular vesicles (EVs) in terms of their smaller particle sizes and lack of a bilayer membrane structure and they are enriched with diverse bioactive molecules particularly proteins and RNAs, which are widely reported to be delivered and packaged in exosomes. This review is focused on the two recently identified membraneless NVEPs, exomeres and supermeres, to provide an overview of their biogenesis and contents, particularly those bioactive substances linked to their bio-properties. This review also explains the concepts and characteristics of these nanoparticles, to compare them with other EVPs, especially EVs, as well as to discuss their isolation and identification methods, research interests, potential clinical applications and open questions.

Exosome-Based Therapeutics in Dermatology

Exosomes (Exos) are tiny extracellular vesicles containing a variety of active biomolecules that play important parts in intercellular communication and influence the functions of target cells. The potential of Exos in the treatment of dermatological diseases has recently been well appreciated. This review highlights the constituents, function, and delivery of Exos, with a particular focus on their applications in skin therapy. Firstly, we offer a concise overview of the biochemical properties of Exos, including their sources, structures, and internal constituents. Subsequently, the biomedical functions of Exos and the latest advances in the extraction and purification of Exos are summarized. We further discuss the modes of delivery of Exos and underscore the potential of biomaterials in this regard. Finally, we summarize the application of Exo-aided therapy in dermatology. Overall, the objective of this review is to provide a comprehensive perspective on the applications and recent advancements of Exo-based approaches in treating skin diseases, with the intention of guiding future research efforts.

Neuron-Derived Extracellular Vesicles: Emerging Regulators in Central Nervous System Disease Progression

The diagnosis and exploration of central nervous system (CNS) diseases remain challenging due to the blood-brain barrier (BBB), complex signaling pathways, and heterogeneous clinical manifestations. Neurons, as the core functional units of the CNS, play a pivotal role in CNS disease progression. Extracellular vesicles (EVs), capable of crossing the BBB, facilitate intercellular and cell-extracellular matrix (ECM) communication, making neuron-derived extracellular vesicles (NDEVs) a focal point of research. Recent studies reveal that NDEVs, carrying various bioactive substances, can exert either pathogenic or protective effects in numerous CNS diseases. Additionally, NDEVs show significant potential as biomarkers for CNS diseases. This review summarizes the emerging roles of NDEVs in CNS diseases, including Alzheimer's disease, depression, traumatic brain injury, schizophrenia, ischemic stroke, Parkinson's disease, amyotrophic lateral sclerosis, and multiple sclerosis. It aims to provide a novel perspective on developing therapeutic and diagnostic strategies for CNS diseases through the study of NDEVs.

Mitochondria in aging and age-associated diseases

Mitochondria, essential for cellular energy, are crucial in neurodegenerative disorders (NDDs) and their age-related progression. This review highlights mitochondrial dynamics, mitovesicles, homeostasis, and organelle communication. We examine mitochondrial impacts from aging and NDDs, focusing on protein aggregation and dysfunction. Prospective therapeutic approaches include enhancing mitophagy, improving respiratory chain function, maintaining calcium and lipid balance, using microRNAs, and mitochondrial transfer to protect function. These strategies underscore the crucial role of mitochondrial health in neuronal survival and cognitive functions, offering new therapeutic opportunities.

Overload of Neprilysin in Placental Extracellular Vesicles Disrupts CNP-NPRB-Mediated Communication Between Vascular Endothelial and Smooth Muscle Cells: A Trigger for Symptoms of Preeclampsia

BACKGROUND

Preeclampsia is a placenta-origin pregnancy complication. Although its development has long been divided into 2 stages: abnormal placentation (stage I) and the release of factors from the hypoperfused placenta into circulation, triggering preeclampsia due to endothelial dysfunction (stage II), the placenta-derived substances coupling the 2 stages remain unclear.

METHODS

Extracellular vesicles (EVs) from normal and preeclampsia-complicated placentas were intravenously administered to pregnant mice, and blood pressure was recorded throughout pregnancy. The differential cargo, including NEP (neprilysin), of placental EVs in normal and preeclamptic placentas was identified by LC-MS, and the cell types involved in NEP expression in the placenta were determined by single-cell RNA sequencing. The effects of placental EVs and recombinant mouse NEP on the uterine arteries were assessed by myography. Placenta-specific NEP overexpression mice were established by in situ injection of adenovirus. The binding affinity between NEP and the vasodilative peptides was determined using an Octet instrument. NEP-overexpressing HUVECs were established to measure CNP (C-type natriuretic peptide) release and cocultured with NPRB (natriuretic peptide receptor-B) knockdown vascular smooth muscle cells (VSMCs) to measure cGMP production in VSMCs.

RESULTS

Placental EVs from preeclamptic pregnancies impaired vascular endothelium-dependent vasodilation and induced preeclampsia in mice. NEP was expressed predominantly by syncytiotrophoblasts and upregulated in placental EVs from preeclamptic pregnancies. Recombinant mouse NEP administration resulted in outcomes like those of administration of placental EVs from preeclamptic pregnancies. Placenta-specific NEP overexpression disturbed maternal hemodynamics, resulting in hypertension and proteinuria of the mice. CNP exhibited high binding affinity for NEP, and NEP upregulation in HUVECs inhibited CNP release, which further influenced the production of cGMP in VSMCs; however, this effect was largely blunted in NPRB-deficient VSMCs.

CONCLUSIONS

Excessive NEP in placental EVs from preeclamptic pregnancies is transported into the endothelial cells of uterine and placental arteries to cleave and degrade CNP, resulting in compromised CNP paracrine activity and NPRB-mediated cGMP production in adjacent VSMCs and triggering the hypertensive manifestation of preeclampsia.

Advances in research on mitochondrial dysfunction in neurodegenerative diseases

Given the high energy demand of the nervous system, mitochondrial dysfunction is a key factor in the pathogenesis of neurodegenerative diseases. Thus, a comprehensive understanding of its mechanisms and potential therapeutic targets is essential. This review discusses the roles of mitochondrial oxidative stress, mitochondrial dynamics alterations, and mtDNA damage in Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), and multiple sclerosis (MS). In addition, it summarizes the contributions of novel technological approaches in detecting mitochondrial dysfunction, which assist in disease diagnosis. We also emphasize emerging therapeutic strategies and drugs aimed at enhancing mitochondrial quality control and reducing oxidative stress, thereby laying the groundwork for innovative therapeutic approaches in neurodegenerative disease treatment.

Mitigating morphine dependence and withdrawal: The role of venlafaxine and calcium channel blockers in mitochondrial damage and oxidative stress in the brain

BACKGROUND

The reasons for morphine dependence and withdrawal symptoms are oxidative stress and dysfunction of cell mitochondria in the brain. Venlafaxine, a serotonin-norepinephrine reuptake inhibitor (SNRI), mitigates oxidative stress, while calcium channel blockers (nimodipine/diltiazem) prevent Ca²⁺-mediated mitochondrial dysfunction. In the present study, the effects of simultaneous administration of venlafaxine and calcium channel blockers on dependence and withdrawal syndrome of morphine and the role of mitochondrial damage and oxidative stress were assessed.

METHODS

In this experimental study, the analgesic effect of venlafaxine, nimodipine, and diltiazem was investigated using the hot plate test to determine the optimal doses of drugs to use in subsequent experiments. To induce morphine dependence and withdrawal syndrome, male NMRI mice were treated with 50 mg/kg S.C. morphine for three consecutive days and 5 mg/kg S.C. morphine on the fourth day. 2 hours after the last dose of morphine, naloxone (5 mg/kg) was injected intraperitoneally, and the signs of jumping and standing were evaluated for 0.5 hours. Venlafaxine (20 mg/kg) alone or in combination with nimodipine (10 mg/kg) and diltiazem (40 mg/kg) was administered half an hour before morphine 50 mg/kg for three days. Brain slides were stained and examined under a light microscope. Brain mitochondria were isolated using a repeated centrifugation method to investigate mitochondrial oxidative stress. The dehydrogenase activity (MTT), membrane potential (MMP), ROS production rate, glutathione (GSH), and malondialdehyde (MDA) contents of the brain mitochondria were measured. The data were expressed as mean±standard deviation, and a p-value less than 0.05 was considered statistically significant.

RESULTS

The administration of naloxone following repeated morphine injection increased withdrawal symptoms compared to the control group (morphine followed by solvent of naloxone) (P < 0.01). Administration of venlafaxine-nimodipine and venlafaxine-diltiazem before morphine reduced these symptoms compared to the morphine + naloxone group (P < 0.01). The injection of morphine followed by naloxone decreased MTT and GSH and increased MDA, MMP, and ROS compared to the control group (P < 0.01), and the injection of venlafaxine-nimodipine and venlafaxine-diltiazem half an hour before morphine reduced these alterations when compared to morphine + naloxone group (P < 0.05).

CONCLUSION

Coadministration of venlafaxine with calcium channel blockers could reduce morphine withdrawal symptoms and prevent its pathological damage. The suggested mechanism of this event is preventing mitochondrial damage and oxidative stress induced by morphine.

The cell biology of Extracellular Vesicles: A jigsaw puzzle with a myriad of pieces

Extracellular vesicle (EV) research has expanded beyond traditional boundaries, evolving into an inter-kingdom endeavor. First described over 50 years ago, EVs are now recognized as playing diverse roles in basic cellular functions, such as intercellular communication, transport, and cell migration. Their biogenesis and secretion involve complex molecular processes, with cargos that include proteins, lipids, and genetic material. Despite advances, isolation and purification methods are still developing. EVs are present in all body fluids, with different subtypes fulfilling distinct roles. Nonetheless, in biological ecosystems, vesicle diversity can be seen as a strength where each one complements the other in the dialogue between cells and tissues. The involvement of EVs in homeostasis and disease and their well-recognized potential for diagnosis and therapeutics will continue to boost investigations to reveal their fundamental biology.

Mesenchymal stem cell exosomes therapy for the treatment of traumatic brain injury: mechanism, progress, challenges and prospects

Traumatic brain injury (TBI) is a heterogeneous disease characterized by brain damage and functional impairment caused by external forces. Under the influence of multiple mechanisms, TBI can cause synaptic dysfunction, protein aggregation, mitochondrial dysfunction, oxidative stress, and neuroinflammatory cascade reactions, resulting in a high disability and mortality rate for patients and a heavy burden on families and society. Exosomes are cell-derived vesicles that encapsulate a variety of molecules, including proteins, lipids, mRNAs, and other small biomolecules. Among these, exosomes derived from mesenchymal stem cells (MSCs) have garnered significant attention owing to their therapeutic potential in the nervous system, offering broad clinical applicability. Recent studies have demonstrated that MSC-derived exosome injections in traumatic brain injury models effectively mitigate local inflammatory damage and promote nerve regeneration following injury. Owing to their small size, challenging replication, ease of preservation, and low immunogenicity, MSC exosomes are emerging as a promising therapeutic strategy for traumatic brain injury. This review explores the pathogenesis of traumatic brain injury, the underlying mechanisms of MSC exosome action, and the potential clinical applications of MSC exosomes in the treatment of traumatic brain injury.

Navigating thyroid cancer complexity: the emerging role of EV-derived non-coding RNAs

Thyroid cancer (TC), which arises from the epithelial cells of the thyroid gland, is experiencing a significant increase in incidence globally. TC encompasses various subtypes, including papillary, follicular, medullary, and anaplastic thyroid cancers, each with distinct pathological and clinical features. Extracellular vesicles (EVs), are naturally occurring and nanosized lipid bilayers, and can be secreted by almost all cell types. EVs, comprising microvesicles and exosomes, are pivotal in mediating intercellular communication within the tumor microenvironment. Notably, EVs possess unique properties such as stability in circulation and the ability to traverse biological barriers, enhancing their role as carriers of molecular information. EVs carry non-coding RNAs (ncRNAs), including miRNAs, lncRNAs, and circRNAs, which are crucial regulators of gene expression. Recent studies have highlighted the significant role of EV-derived ncRNAs in influencing thyroid cancer progression, metastasis, and immune modulation by mediating intercellular communication within the tumor microenvironment. The expression of EV-derived ncRNAs varies across different stages of thyroid cancer, reflecting potential as biomarkers for diagnosis and targets for therapy. This review delves into the multifaceted roles of EV-ncRNAs in thyroid cancer, emphasizing their impact on tumor growth, metastatic potential, and immune interactions, while also exploring their promising applications in early diagnosis and targeted treatment strategies. Understanding these dynamics is essential for developing innovative interventions to improve patient outcomes in thyroid cancer.

Extracellular particles: emerging insights into central nervous system diseases

Extracellular particles (EPs), including extracellular vesicles (EVs) and non-vesicular extracellular particles (NVEPs), are multimolecular biomaterials released by cells that play a crucial role in intercellular communication. Recently, new subtypes of EPs associated with central nervous system (CNS), such as exophers and supermeres have been identified. These EPs provide new perspectives for understanding the pathological progression of CNS disorders and confer potential diagnostic value for liquid biopsies in neurodegenerative diseases (NDs). Moreover, EPs have emerged as promising drug delivery vehicles and targeted platforms for CNS-specific therapies. In this review, we delineate the landscape of EP subtypes and their roles in the pathophysiology of CNS diseases. We also review the recent advances of EP-based diagnosis in NDs and highlight the importance of analytical platforms with single-particle resolution in the exploitation of potential biomarkers. Furthermore, we summarize the application of engineered EVs in the treatment of CNS diseases and outline the underexplored potential of NVEPs as novel therapeutic agents.

Extracellular Vesicles as a Potential Therapy for Stroke

Although thrombolytic therapy has enjoyed relative success, limitations remain, such as a narrow therapeutic window and inconsistent efficacy. Consequently, there is a pressing need to develop novel therapeutic approaches. In recent years, extracellular vesicles (EVs) have garnered increasing attention as a potential alternative to stem cell therapy. Because of their ability to cross the blood-brain barrier and exert neuroprotective effects in cerebral ischemia and hemorrhage, the exploration of EVs for clinical application in stroke treatment is expanding. EVs are characterized by high heterogeneity, with their composition closely mirroring that of their parent cells. This property enables EVs to distinguish between cerebral ischemia and hemorrhage, thus facilitating a more rapid and accurate diagnosis. Additionally, EVs can be engineered to carry specific molecules, such as miRNAs, targeting them to specific cells, potentially enhancing the therapeutic outcome and improving stroke prognosis. In this review, we will also explore the methodologies for the isolation and extraction of EVs, critically evaluating the advantages and disadvantages of various commonly employed separation techniques. Furthermore, we will briefly address current EV preservation and administration methods, providing a comprehensive overview of the state of EV-based therapies in stroke treatment.

Liquid biopsies in cancer

Cancer ranks among the most lethal diseases worldwide. Tissue biopsy is currently the primary method for the diagnosis and biological analysis of various solid tumors. However, this method has some disadvantages related to insufficient tissue specimen collection and intratumoral heterogeneity. Liquid biopsy is a noninvasive approach for identifying cancer-related biomarkers in peripheral blood, which allows for repetitive sampling across multiple time points. In the field of liquid biopsy, representative biomarkers include circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), and exosomes. Many studies have evaluated the prognostic and predictive roles of CTCs and ctDNA in various solid tumors. Although these studies have limitations, the results of most studies appear to consistently demonstrate the correlations of high CTC counts and ctDNA mutations with lower survival rates in cancer patients. Similarly, a reduction in CTC counts throughout therapy may be a potential prognostic indicator related to treatment response in advanced cancer patients. Moreover, the biochemical characteristics of CTCs and ctDNA can provide information about tumor biology as well as resistance mechanisms against targeted therapy. This review discusses the current clinical applications of liquid biopsy in cancer patients, emphasizing its possible utility in outcome prediction and treatment decision-making.

A New Insight on Atherosclerosis Mechanism and Lipid-Lowering Drugs

Atherosclerosis (AS) is a chronic vascular disease primarily affecting large and medium-sized arteries, involving complex pathological mechanisms such as inflammatory responses, lipid metabolism disorders and vascular plaque formation. In recent years, several emerging research hotspots have appeared in the field of atherosclerosis, including gut microbiota, pyroptosis, ferroptosis, autophagy, cuproptosis, exosomes and non-coding RNA. Traditional lipid-lowering drugs play a crucial role in the treatment of AS but are not able to significantly reverse the pathological changes. This article aims to summarize the latest research progress in the pathogenesis of AS and the diagnosis and treatment of the disease by comprehensively analyzing relevant literature mainly from the past five years. Additionally, the mechanisms of action and research advances of statins, cholesterol absorption inhibitors, fibrates and novel lipid-lowering drugs are reviewed to provide new insights into the diagnosis and treatment of AS.

The uptake of extracellular vesicles: Research progress in cancer drug resistance and beyond

Extracellular vesicles (EVs) are heterogeneous vesicles released by donor cells that can be taken up by recipient cells, thus inducing cellular phenotype changes. Since their discovery decades ago, roles of EVs in modulating initiation, growth, survival and metastasis of cancer have been revealed. Recent studies from multifaceted perspectives have further detailed the contribution of EVs to cancer drug resistance; however, the role of EV uptake in conferring drug resistance seems to be overlooked. In this comprehensive review, we update the EV subtypes and approaches for determining EV uptake. The biological basis of EV uptake is systematically summarized. Moreover, we focus on the diverse uptake mechanisms by which EVs carry out the intracellular delivery of functional molecules and drug resistance signaling. Furthermore, we highlight how EV uptake confers drug resistance and identify potential strategies for targeting EV uptake to overcome drug resistance. Finally, we discuss the research gap on the role of EV uptake in promoting drug resistance. This updated knowledge provides a new avenue to overcome cancer drug resistance by targeting EV uptake.

Exosomal miR-302b rejuvenates aging mice by reversing the proliferative arrest of senescent cells

Cellular senescence, a hallmark of aging, involves a stable exit from the cell cycle. Senescent cells (SnCs) are closely associated with aging and aging-related disorders, making them potential targets for anti-aging interventions. In this study, we demonstrated that human embryonic stem cell-derived exosomes (hESC-Exos) reversed senescence by restoring the proliferative capacity of SnCs in vitro. In aging mice, hESC-Exos treatment remodeled the proliferative landscape of SnCs, leading to rejuvenation, as evidenced by extended lifespan, improved physical performance, and reduced aging markers. Ago2 Clip-seq analysis identified miR-302b enriched in hESC-Exos that specifically targeted the cell cycle inhibitors Cdkn1a and Ccng2. Furthermore, miR-302b treatment reversed the proliferative arrest of SnCs in vivo, resulting in rejuvenation without safety concerns over a 24-month observation period. These findings demonstrate that exosomal miR-302b has the potential to reverse cellular senescence, offering a promising approach to mitigate senescence-related pathologies and aging.

Exosomes in the Chemoresistance of Glioma: Key Point in Chemoresistance

Gliomas are the most ordinary primary virulent brain tumours and commonly used clinical treatments include tumour resection, radiation therapy and chemotherapy. Although significant progress has been made in recent years in progression-free survival (PFS) and overall survival (OS) for patients with high-grade gliomas, the prognosis for patients remains poor. Chemoresistance refers to the phenomenon of decreased sensitivity of tumour cells to drugs, resulting in reduced or ineffective drug efficacy, and is an important cause of failure of tumour chemotherapy. Exosomes, a type of extracellular vesicle, are secreted by cancer cells and various stromal cells in the tumour microenvironment (TME) and transfer their inclusions to cancer cells, increasing chemoresistance. Furthermore, depletion of exosomes reverses certain detrimental effects on tumour metabolism and restores sensitivity to chemotherapeutic agents. Here, we summarised the correlation between exosomes and resistance to chemotherapeutic agents in glioma patients, the mechanisms of action of exosomes involved in resistance and their clinical value. We aimed to afford new thoughts for research, clinical diagnosis and intervention in the mechanisms of chemoresistance in glioma patients.

Altered ATP13A2/PARK9 Levels Influence α-Synuclein Accumulation in Neurons via Phagocytosis and Secretion in Glial Cells

(1) Background: Parkinson's disease (PD) is characterized by the pathological accumulation of α-synuclein (α-syn) containing Lewy bodies (LBs) and Lewy neurites (LNs) within neurons. Growing evidence indicates that α-syn may propagate throughout the nervous system in a manner similar to prion-like transmission. Extracellular vesicles (EVs) may contribute to this pathway. We and others have reported that ATP13A2/PARK9 deficiency results in decreased EVs while its overexpression leads to increased EV generation. For analyzing EV-mediated α-syn secretion in neighboring neurons, we planned to alter Atp13a2 levels in vivo. (2) Methods: Three months after inoculating mouse α-syn fibrils into the striatum of Atp13a2-null and wild-type mice, we stained brain sections with anti-phosphorylated α-syn antibodies and then quantified LBs/LNs. We also examined the effect of increased levels of ATP13A2 by injecting lentivirus carrying human ATP13A2. Finally, we used cultured astrocytes and microglia for α-syn uptake and release, which were mediated by EVs. (3) Results: While LBs/LNs were formed in the entire brains, no significant difference was observed in LB/LN formation between Atp13a2-deficient and wild-type mice. Interestingly, the overexpression of ATP13A2 led to decreased LB/LN formation in the entire brains. Microglia and astrocytes released EVs more than neurons. EVs released from microglia and astrocytes contained more α-syn PFFs than those from neurons. (4) Conclusions: These results suggest that enhanced EV secretion by increased ATP13A2 levels attenuate the spreading of α-syn in brains, suggesting a protective role of ATP13A2 in α-synucleinopathies.

Consistency in bacterial extracellular vesicle production: key to their application in human health

Bacterial extracellular vesicles (BEVs) are naturally occurring functional structures that play critical roles in bacterial life processes. These vesicles, commonly known as outer membrane vesicles (OMVs), were first found to be released by Gram-negative bacteria; however, it has since been confirmed that Gram-positive bacteria also secrete BEVs. As research advances, BEVs are increasingly utilized in diverse applications, including vaccine development and drug delivery. Nevertheless, the effective employment of BEVs in these contexts requires the acquisition of vesicles with consistent properties and functions through appropriate culture, isolation, and purification methods. This review examines the advantages and disadvantages of various purification techniques alongside the heterogeneity they may introduce. We utilize the heterogeneity of BEVs as a framework to critically analyze the barriers to their application and the factors influencing their characteristics. Additionally, we constructively propose solutions to enhance the consistency of BEVs, thereby facilitating their further development and application.

Regenerative properties of bone marrow mesenchymal stem cell derived exosomes in rotator cuff tears

ABSTRCT

Rotator cuff injury (RCI), characterized by shoulder pain and restricted mobility, represents a subset of tendon-bone insertion injuries (TBI). In the majority of cases, surgical reconstruction of the affected tendons or ligaments is required to address the damage. However, numerous clinical failures have underscored the suboptimal outcomes associated with such procedures. Further investigations have revealed that these failures are largely attributable to delayed healing at the tendon-bone interface, excessive formation of vascularized scar tissue, and inadequate integration of tendon grafts within bone tunnels. As a result, the healing process of rotator cuff injuries faces significant challenges.Bone marrow-derived mesenchymal stem cell exosomes (BMSC-exos) have emerged as a prominent focus of research within the field of bioengineering, owing to their remarkable potential to regulate cellular proliferation and differentiation, modulate immune responses, and facilitate tissue repair and regeneration following cellular damage. In this review, we explore the anti-inflammatory, angiogenic, anti-scarring, and bone metabolism-modulating effects of BMSC-exos in the context of rotator cuff injury. Additionally, we address the limitations and ongoing challenges within current research, offering insights that could guide the clinical application of BMSC-exos in the treatment of rotator cuff injuries in the future.

Tau filaments are tethered within brain extracellular vesicles in Alzheimer's disease

The abnormal assembly of tau protein in neurons is a pathological hallmark of multiple neurodegenerative diseases, including Alzheimer's disease (AD). Assembled tau associates with extracellular vesicles (EVs) in the central nervous system of individuals with AD, which is linked to its clearance and prion-like propagation. However, the identities of the assembled tau species and EVs, as well as how they associate, are not known. Here, we combined quantitative mass spectrometry, cryo-electron tomography and single-particle cryo-electron microscopy to study brain EVs from individuals with AD. We found tau filaments composed mainly of truncated tau that were enclosed within EVs enriched in endo-lysosomal proteins. We observed multiple filament interactions, including with molecules that tethered filaments to the EV limiting membrane, suggesting selective packaging. Our findings will guide studies into the molecular mechanisms of EV-mediated secretion of assembled tau and inform the targeting of EV-associated tau as potential therapeutic and biomarker strategies for AD.

Extracellular Vesicles From Bone Marrow-Derived Macrophages Enriched in ARG1 Enhance Microglial Phagocytosis and Haematoma Clearance Following Intracerebral Haemorrhage

Microglial phagocytosis of haematomas is crucial for neural functional recovery following intracerebral haemorrhage (ICH), a process regulated by various factors from within and outside the central nervous system (CNS). Extracellular vesicles (EVs), significant mediators of intercellular communication, have been demonstrated to play a pivotal role in the pathogenesis and progression of CNS diseases. However, the regulatory role of endogenous EVs on the phagocytic capacity of microglia post-ICH remains elusive. Utilising multi-omics analysis of brain tissue-derived EVs proteomics and single-cell RNA sequencing, this study identified that bone marrow-derived macrophages (BMDMs) potentially enhance microglial phagocytosis via EVs following ICH. By blocking BMDMs and reducing ARG1 in BMDM-derived EVs, we demonstrated that BMDMs facilitate erythrophagocytosis by delivering ARG1 to microglia via EVs post-ICH. EVs-carried ARG1 was found to augment phagocytosis by promoting RAC1-dependent cytoskeletal remodelling in microglia. Collectively, this research uncovers an intercellular communication pathway from BMDMs to microglia mediated by EVs post-ICH. This provides a novel paradigm for EV-mediated intercellular communication mechanisms and suggests a promising therapeutic potential for BMDM-derived EVs in the treatment of ICH.

Mitochondria break free: Mitochondria-derived vesicles in aging and associated conditions

Mitophagy is the intracellular recycling system that disposes damaged/inefficient mitochondria and allows biogenesis of new organelles to ensure mitochondrial quality is optimized. Dysfunctional mitophagy has been implicated in human aging and diseases. Multiple evolutionarily selected, redundant mechanisms of mitophagy have been identified, but their specific roles in human health and their potential exploitation as therapeutic targets are unclear. Recently, the characterization of the endosomal-lysosomal system has revealed additional mechanisms of mitophagy and mitochondrial quality control that operate via the production of mitochondria-derived vesicles (MDVs). Circulating MDVs can be isolated and characterized to provide an unprecedented opportunity to study this type of mitochondrial recycling in vivo and to relate it to human physiology and pathology. Defining the role of MDVs in human physiology, pathology, and aging is hampered by the lack of standardized methods to isolate, validate, and characterize these vesicles. Hence, some basic questions about MDVs remain unanswered. While MDVs are generated directly through the extrusion of mitochondrial membranes within the cell, a set of circulating extracellular vesicles leaking from the endosomal-lysosomal system and containing mitochondrial portions have also been identified and warrant investigation. Preliminary research indicates that MDV generation serves multiple biological roles and contributes to restoring cell homeostasis. However, studies have shown that MDVs may also be involved in pathological conditions. Therefore, further research is warranted to establish when/whether MDVs are supporting disease progression and/or are extracting damaged mitochondrial components to alleviate cellular oxidative burden and restore redox homeoastasis. This information will be relevant for exploiting these vesicles for therapeutic purpose. Herein, we provide an overview of preclinical and clinical studies on MDVs in aging and associated conditions and discuss the interplay between MDVs and some of the hallmarks of aging (mitophagy, inflammation, and proteostasis). We also outline open questions on MDV research that should be prioritized by future investigations.

Isolation and Comprehensive Analysis of Cochlear Tissue-Derived Small Extracellular Vesicles

Small extracellular vesicles (sEVs) act as a critical mediator in intercellular communication. Compared to sEVs derived from in vitro sources, tissue-derived sEVs can reflect the in vivo signals released from specific tissues more accurately. Currently, studies on the role of sEVs in the cochlea have relied on studying sEVs from in vitro sources. This study evaluates three cochlear tissue digestion and cochlear tissue-derived sEV (CDsEV) isolation methods, and first proposes that the optimal approach for isolating CDsEVs using collagenase D and DNase І combined with sucrose density gradient centrifugation. Furthermore, it comprehensively investigates CDsEV contents and cell origins. Small RNA sequencing and proteomics are performed to analyze the miRNAs and proteins of CDsEVs. The miRNAs and proteins of CDsEVs are crucial for maintaining normal auditory function. Among them, FGFR1 in CDsEVs may mediate the survival of cochlear hair cells via sEVs. Finally, the joint analysis of single CDsEV sequencing and single-cell RNA sequencing data is utilized to trace cellular origins of CDsEVs. The results show that different types of cochlear cells secrete different amounts of CDsEVs, with Kölliker's organ cells and supporting cells secrete the most. The findings are expected to enhance the understanding of CDsEVs in the cochlea.

From dysfunction to healing: advances in mitochondrial therapy for Osteoarthritis

Osteoarthritis (OA) is a chronic degenerative joint condition characterised by cartilage deterioration and changes in bone morphology, resulting in pain and impaired joint mobility. Investigation into the pathophysiological mechanisms underlying OA has highlighted the significance of mitochondrial dysfunction in its progression. Mitochondria, which are cellular organelles, play a crucial role in regulating energy metabolism, generating reactive oxygen species, and facilitating essential biological processes including apoptosis. In recent years, the utilisation of exogenous drugs and MT to improve mitochondrial function in chondrocytes has shown great promise in OA treatment. Numerous studies have investigated the potential of stem cells and extracellular vesicles in mitochondrial transfer. This review aims to explore the underlying mechanisms of mitochondrial dysfunction in OA and assess the progress in utilising mitochondrial transfer as a therapeutic approach for this disease.

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.

Efficient enzyme-free isolation of brain-derived extracellular vesicles

Extracellular vesicles (EVs) have gained significant attention as pathology mediators and potential diagnostic tools for neurodegenerative diseases. However, isolation of brain-derived EVs (BDEVs) from tissue remains challenging, often involving enzymatic digestion steps that may compromise the integrity of EV proteins and overall functionality. Here, we describe that collagenase digestion, commonly used for BDEV isolation, produces undesired protein cleavage of EV-associated proteins in brain tissue homogenates and cell-derived EVs. In order to avoid this effect, we studied the possibility of isolating BDEVs with a reduced amount of collagenase or without any protease. Characterization of the isolated BDEVs from mouse and human samples (both female and male) revealed their characteristic morphology and size distribution with both approaches. However, we show that even minor enzymatic digestion induces 'artificial' proteolytic processing in key BDEV markers, such as Flotillin-1, CD81, and the cellular prion protein (PrPC), whereas avoiding enzymatic treatment completely preserves their integrity. We found no major differences in mRNA and protein content between non-enzymatically and enzymatically isolated BDEVs, suggesting that the same BDEV populations are purified with both approaches. Intriguingly, the lack of Golgi marker GM130 signal, often referred to as contamination indicator (or negative marker) in EV preparations, seems to result from enzymatic digestion rather than from its actual absence in BDEV samples. Overall, we show that non-enzymatic isolation of EVs from brain tissue is possible and avoids artificial pruning of proteins while achieving an overall high BDEV yield and purity. This protocol will help to understand the functions of BDEV and their associated proteins in a near-physiological setting, thus opening new research approaches.

The impact of exosomes on bone health: A focus on osteoporosis

Osteoporosis is a widespread chronic condition. Although standard treatments are generally effective, they are frequently constrained by side effects and the risk of developing drug resistance. A promising area of research is the investigation of extracellular vesicles (EVs), including exosomes, microvesicles, and apoptotic bodies, which play a crucial role in bone metabolism. Exosomes, in particular, have shown significant potential in both the diagnosis and treatment of osteoporosis. EVs derived from osteoclasts, osteoblasts, mesenchymal stem cells, and other sources can influence bone metabolism, while exosomes from inflammatory and tumor cells may exacerbate bone loss, highlighting their dual role in osteoporosis pathology. This review offers a comprehensive overview of EV biogenesis, composition, and function in osteoporosis, focusing on their diagnostic and therapeutic potential. We examine the roles of various types of EVs and their cargo-proteins, RNAs, and lipids-in bone metabolism. Additionally, we explore the emerging applications of EVs as biomarkers and therapeutic agents, emphasizing the need for further research to address current challenges and enhance EV-based strategies for managing osteoporosis.

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.

Autophagy and autophagic cell death in sepsis: friend or foe?

In sepsis, inflammation, and nutrient deficiencies endanger cellular homeostasis and survival. Autophagy is primarily a mechanism of cellular survival under fasting conditions. However, autophagy-dependent cell death, known as autophagic cell death, is proinflammatory and can exacerbate sepsis. Autophagy also regulates various types of non-inflammatory and inflammatory cell deaths. Non-inflammatory apoptosis tends to suppress inflammation, however, inflammatory necroptosis, pyroptosis, ferroptosis, and autophagic cell death lead to the release of inflammatory cytokines and damage-associated molecular patterns (DAMPs) and amplify inflammation. The selection of cell death mechanisms is complex and often involves a mixture of various styles. Similarly, protective autophagy and lethal autophagy may be triggered simultaneously in cells. How cells balance the regulatory mechanisms of these processes is an area of interest that is still under investigation. Therapies aimed at modulating autophagy are considered promising. Enhancing autophagy helps clear and recycle damaged organelles and reduce the burden of inflammatory processes while inhibiting excessive autophagy, which could prevent autophagic cell death. In this review, we introduce recent advances in research and the complex regulatory system of autophagy in sepsis.

Mitochondrial Extracellular Vesicles: A Promising Avenue for Diagnosing and Treating Lung Diseases

Mitochondria, pivotal organelles governing cellular biosynthesis, energy metabolism, and signal transduction, maintain dynamic equilibrium through processes such as biogenesis, fusion, fission, and mitophagy. Growing evidence implicates mitochondrial dysfunction in a spectrum of respiratory diseases including acute lung injury/acute respiratory distress syndrome, bronchial asthma, pulmonary fibrosis, chronic obstructive pulmonary disease, and lung cancer. Consequently, identifying methods capable of ameliorating damaged mitochondrial function is crucial for the treatment of pulmonary diseases. Extracellular vesicles (EVs), nanosized membrane vesicles released by cells into the extracellular space, facilitate intercellular communication by transferring bioactive substances or signals between cells or organs. Recent studies have identified abundant mitochondrial components within specific subsets of EVs, termed mitochondrial extracellular vesicles (mitoEVs), whose contents and compositions vary with disease progression. Moreover, mitoEVs have demonstrated reparative mitochondrial functions in injured recipient cells. However, a comprehensive understanding of mitoEVs is currently lacking, limiting their clinical translation prospects. This Review explores the biogenesis, classification, functional mitochondrial cargo, and biological effects of mitoEVs, with a focus on their role in pulmonary diseases. Emphasis is placed on their potential as biological markers and innovative therapeutic strategies in pulmonary diseases, offering fresh insights for mechanistic studies and drug development in various pulmonary disorders.

LAMTOR1 decreased exosomal PD-L1 to enhance immunotherapy efficacy in non-small cell lung cancer

Great progress has been made in utilizing immune checkpoint blockade (ICB) for the treatment of non-small-cell lung cancer (NSCLC). Therapies targeting programmed cell death protein 1 (PD-1) and its ligand PD-L1, expressed on tumor cells, have demonstrated potential in improving patient survival rates. An unresolved issue involves immune suppression induced by exosomal PD-L1 within the tumor microenvironment (TME), particularly regarding CD8+ T cells. Our study unveiled the crucial involvement of LAMTOR1 in suppressing the exosomes of PD-L1 and promoting CD8+ T cell infiltration in NSCLC. Through its interaction with HRS, LAMTOR1 facilitates PD-L1 lysosomal degradation, thereby reducing exosomal PD-L1 release. Notably, the ability of LAMTOR1 to promote PD-L1 lysosomal degradation relies on a specific ubiquitination site and an HRS binding sequence. The findings suggest that employing LAMTOR1 to construct peptides could serve as a promising strategy for bolstering the efficacy of immunotherapy in NSCLC. The discovery and comprehension of how LAMTOR1 inhibits the release of exosomal PD-L1 offer insights into potential therapeutic strategies for improving immunotherapy. It is imperative to conduct further research and clinical trials to investigate the feasibility and efficacy of targeting LAMTOR1 in NSCLC treatment.

The complexity of extracellular vesicles: Bridging the gap between cellular communication and neuropathology

Brain-derived extracellular vesicles (EVs) serve a prominent role in maintaining homeostasis and contributing to pathology in health and disease. This review establishes a crucial link between physiological processes leading to EV biogenesis and their impacts on disease. EVs are involved in the clearance and transport of proteins and nucleic acids, responding to changes in cellular processes associated with neurodegeneration, including autophagic disruption, organellar dysfunction, aging, and other cell stresses. In neurodegenerative disorders (e.g., Alzheimer's disease, Parkinson's disease, etc.), EVs contribute to the spread of pathological proteins like amyloid β, tau, ɑ-synuclein, prions, and TDP-43, exacerbating neurodegeneration and accelerating disease progression. Despite evidence for both neuropathological and neuroprotective effects of EVs, the mechanistic switch between their physiological and pathological functions remains elusive, warranting further research into their involvement in neurodegenerative disease. Moreover, owing to their innate ability to traverse the blood-brain barrier and their ubiquitous nature, EVs emerge as promising candidates for novel diagnostic and therapeutic strategies. The review uniquely positions itself at the intersection of EV cell biology, neurophysiology, and neuropathology, offering insights into the diverse biological roles of EVs in health and disease.

Yin-Yang: two sides of extracellular vesicles in inflammatory diseases

The concept of Yin-Yang, originating in ancient Chinese philosophy, symbolizes two opposing but complementary forces or principles found in all aspects of life. This concept can be quite fitting in the context of extracellular vehicles (EVs) and inflammatory diseases. Over the past decades, numerous studies have revealed that EVs can exhibit dual sides, acting as both pro- and anti-inflammatory agents, akin to the concept of Yin-Yang theory (i.e., two sides of a coin). This has enabled EVs to serve as potential indicators of pathogenesis or be manipulated for therapeutic purposes by influencing immune and inflammatory pathways. This review delves into the recent advances in understanding the Yin-Yang sides of EVs and their regulation in specific inflammatory diseases. We shed light on the current prospects of engineering EVs for treating inflammatory conditions. The Yin-Yang principle of EVs bestows upon them great potential as, therapeutic, and preventive agents for inflammatory diseases.

Simultaneous detection of membrane protein and mRNA at single extracellular vesicle level by droplet microfluidics for cancer diagnosis

INTRODUCTION

Simultaneous detection of proteins and mRNA within a single extracellular vesicle (EV) enables comprehensive analysis of specific EVs subpopulations, significantly advancing cancer diagnostics. However, developing a sensitive and user-friendly approach for simultaneously detecting multidimensional biomarkers in single EV is still challenging.

OBJECTIVES

To facilitate the analysis of multidimensional biomarkers in EVs and boost its clinical application, we present a versatile droplet digital system facilitating the concurrent detection of membrane proteins and mRNA at the single EV level with high sensitivity and specificity.

METHODS

The antibody-DNA conjugates were firstly prepared for EVs protein biomarkers recognition and signal transformation. Coupling with the assembled triplex droplet digital PCR system, a versatile droplet digital analysis assay for simultaneous detection of membrane protein and mRNA at a single EV level was developed.

RESULTS

Our new droplet digital system displayed high sensitivity and specificity. Additionally, its clinical application was validated in a breast cancer cohort. As expected, this assay has demonstrated superior performance in distinguishing breast cancer from healthy individuals and benign controls through combined detection of EVs protein and mRNA markers compared to any single kind marker detections, especially for patients with breast cancer at early stage (AUC=0.9229).

CONCLUSION

Consequently, this study proposes a promising strategy for accurately identifying and analyzing specific EV subgroups through the co-detection of proteins and mRNA at the single EV level, holding significant potential for future clinical applications.

Targeting mitochondrial quality control: new therapeutic strategies for major diseases

Mitochondria play a crucial role in maintaining the normal physiological state of cells. Hence, ensuring mitochondrial quality control is imperative for the prevention and treatment of numerous diseases. Previous reviews on this topic have however been inconsistencies and lack of systematic organization. Therefore, this review aims to provide a comprehensive and systematic overview of mitochondrial quality control and explore the possibility of targeting the same for the treatment of major diseases. This review systematically summarizes three fundamental characteristics of mitochondrial quality control, including mitochondrial morphology and dynamics, function and metabolism, and protein expression and regulation. It also extensively examines how imbalances in mitochondrial quality are linked to major diseases, such as ischemia-hypoxia, inflammatory disorders, viral infections, metabolic dysregulations, degenerative conditions, and tumors. Additionally, the review explores innovative approaches to target mitochondrial quality control, including using small molecule drugs that regulate critical steps in maintaining mitochondrial quality, nanomolecular materials designed for precise targeting of mitochondria, and novel cellular therapies, such as vesicle therapy and mitochondrial transplantation. This review offers a novel perspective on comprehending the shared mechanisms underlying the occurrence and progression of major diseases and provides theoretical support and practical guidance for the clinical implementation of innovative therapeutic strategies that target mitochondrial quality control for treating major diseases.

Extracellular vesicles: opening up a new perspective for the diagnosis and treatment of mitochondrial dysfunction

Mitochondria are crucial organelles responsible for energy generation in eukaryotic cells. Oxidative stress, calcium disorders, and mitochondrial DNA abnormalities can all cause mitochondrial dysfunction. It is now well documented that mitochondrial dysfunction significantly contributes to the pathogenesis of numerous illnesses. Hence, it is vital to investigate innovative treatment methods targeting mitochondrial dysfunction. Extracellular vesicles (EVs) are cell-derived nanovesicles that serve as intercellular messengers and are classified into small EVs (sEVs, < 200 nm) and large EVs (lEVs, > 200 nm) based on their sizes. It is worth noting that certain subtypes of EVs are rich in mitochondrial components (even structurally intact mitochondria) and possess the ability to transfer them or other contents including proteins and nucleic acids to recipient cells to modulate their mitochondrial function. Specifically, EVs can modulate target cell mitochondrial homeostasis as well as mitochondria-controlled apoptosis and ROS generation by delivering relevant substances. In addition, the artificial modification of EVs as delivery carriers for therapeutic goods targeting mitochondria is also a current research hotspot. In this article, we will focus on the ability of EVs to modulate the mitochondrial function of target cells, aiming to offer novel perspectives on therapeutic approaches for diverse conditions linked to mitochondrial dysfunction.

Biogenesis and secretion of mitovesicles, small extracellular vesicles of mitochondrial origin at the crossroads between brain health and disease

In the brain, mitochondrial components are released into the extracellular space via several mechanisms, including a recently identified type of extracellular vesicles called mitovesicles. While vesiculation of neuronal mitochondria yields various intracellular types of vesicles, with either a single or a double membrane, mitovesicles secreted into the extracellular space are a unique subtype of these mitochondria-derived vesicles, with a double membrane and a specific set of mitochondrial DNA, RNA, proteins, and lipids. Based on the most relevant literature describing mitochondrial vesiculation and mitochondrial exocytosis, we propose a model for their secretion when the amphisome, a hybrid endosome-autophagosome organelle, fuses with the plasma membrane, releasing mitovesicles and exosomes into the extracellular space. In aging and neurodegenerative disorders, mitochondrial dysfunction, in association with endolysosomal abnormalities, alter mitovesicle number and content, with downstream effect on brain health.

Extracellular vesicles meet mitochondria: Potential roles in regenerative medicine

Extracellular vesicles (EVs), secreted by most cells, act as natural cell-derived carriers for delivering proteins, nucleic acids, and organelles between cells. Mitochondria are highly dynamic organelles responsible for energy production and cellular physiological processes. Recent evidence has highlighted the pivotal role of EVs in intercellular mitochondrial content transfer, including mitochondrial DNA (mtDNA), proteins, and intact mitochondria. Intriguingly, mitochondria are crucial mediators of EVs release, suggesting an interplay between EVs and mitochondria and their potential implications in physiology and pathology. However, in this expanding field, much remains unknown regarding the function and mechanism of crosstalk between EVs and mitochondria and the transport of mitochondrial EVs. Herein, we shed light on the physiological and pathological functions of EVs and mitochondria, potential mechanisms underlying their interactions, delivery of mitochondria-rich EVs, and their clinical applications in regenerative medicine.

Regenerative endodontic therapy: From laboratory bench to clinical practice

BACKGROUND

Maintaining the vitality and functionality of dental pulp is paramount for tooth integrity, longevity, and homeostasis. Aiming to treat irreversible pulpitis and necrosis, there has been a paradigm shift from conventional root canal treatment towards regenerative endodontic therapy.

AIM OF REVIEW

This extensive and multipart review presents crucial laboratory and practical issues related to pulp-dentin complex regeneration aimed towards advancing clinical translation of regenerative endodontic therapy and enhancing human life quality.

KEY SCIENTIFIC CONCEPTS OF REVIEW

In this multipart review paper, we first present a panorama of emerging potential tissue engineering strategies for pulp-dentin complex regeneration from cell transplantation and cell homing perspectives, emphasizing the critical regenerative components of stem cells, biomaterials, and conducive microenvironments. Then, this review provides details about current clinically practiced pulp regenerative/reparative approaches, including direct pulp capping and root revascularization, with a specific focus on the remaining hurdles and bright prospects in developing such therapies. Next, special attention was devoted to discussing the innovative biomimetic perspectives opened in establishing functional tissues by employing exosomes and cell aggregates, which will benefit the clinical translation of dental pulp engineering protocols. Finally, we summarize careful consideration that should be given to basic research and clinical applications of regenerative endodontics. In particular, this review article highlights significant challenges associated with residual infection and inflammation and identifies future insightful directions in creating antibacterial and immunomodulatory microenvironments so that clinicians and researchers can comprehensively understand crucial clinical aspects of regenerative endodontic procedures.

Nanoplasmonic sensors for extracellular vesicles and bacterial membrane vesicles

Extracellular vesicles (EVs) are promising tools for the early diagnosis of diseases, and bacterial membrane vesicles (MVs) are especially important in health and environment monitoring. However, detecting EVs or bacterial MVs presents significant challenges for the clinical translation of EV-based diagnostics. In this Review, we provide a comprehensive discussion on the basics of nanoplasmonic sensing and emphasize recent developments in nanoplasmonics-based optical sensors to effectively identify EVs or bacterial MVs. We explore various nanoplasmonic sensors tailored for EV or bacterial MV detection, emphasizing the application of localized surface plasmon resonance through gold nanoparticles and their multimers. Additionally, we highlight advanced EV detection techniques based on surface plasmon polaritons using plasmonic thin film and nanopatterned structures. Furthermore, we evaluate the improved detection capability of surface-enhanced Raman spectroscopy in identifying and classifying these vesicles, aided by plasmonic nanostructures. Nanoplasmonic sensing techniques have remarkable precision and sensitivity, making them a potential tool for accurate EV detection in clinical applications, facilitating point-of-care molecular diagnostics. Finally, we summarize the challenges associated with nanoplasmonic EV or bacterial MV sensors and offer insights into potential future directions for this evolving field.

Proteomic profiling of mesenchymal stem cell-derived extracellular vesicles: Impact of isolation methods on protein cargo

Extracellular vesicles (EVs) are nanosized vesicles with a lipid bilayer that are secreted by cells and play a critical role in cell-to-cell communication. Despite the promising reports regarding their diagnostic and therapeutic potential, the utilization of EVs in the clinical setting is limited due to insufficient information about their cargo and a lack of standardization in isolation and analysis methods. Considering protein cargos in EVs as key contributors to their therapeutic potency, we conducted a tandem mass tag (TMT) quantitative proteomics analysis of three subpopulations of mesenchymal stem cell (MSC)-derived EVs obtained through three different isolation techniques: ultracentrifugation (UC), high-speed centrifugation (HS), and ultracentrifugation on sucrose cushion (SU). Subsequently, we checked EV marker expression, size distribution, and morphological characterization, followed by bioinformatic analysis. The bioinformatic analysis of the proteome results revealed that these subpopulations exhibit distinct molecular and functional characteristics. The choice of isolation method impacts the proteome of isolated EVs by isolating different subpopulations of EVs. Specifically, EVs isolated through the high-speed centrifugation (HS) method exhibited a higher abundance of ribosomal and mitochondrial proteins. Functional apoptosis assays comparing isolated mitochondria with EVs isolated through different methods revealed that HS-EVs, but not other EVs, induced early apoptosis in cancer cells. On the other hand, EVs isolated using the sucrose cushion (SU) and ultracentrifugation (UC) methods demonstrated a higher abundance of proteins primarily involved in the immune response, cell-cell interactions and extracellular matrix interactions. Our analyses unveil notable disparities in proteins and associated biological functions among EV subpopulations, underscoring the importance of meticulously selecting isolation methods and resultant EV subpopulations based on the intended application.

Cystatin C loaded in brain-derived extracellular vesicles rescues synapses after ischemic insult in vitro and in vivo

Synaptic loss is an early event in the penumbra area after an ischemic stroke. Promoting synaptic preservation in this area would likely improve functional neurological recovery. We aimed to detect proteins involved in endogenous protection mechanisms of synapses in the penumbra after stroke and to analyse potential beneficial effects of these candidates for a prospective stroke treatment. For this, we performed Liquid Chromatography coupled to Mass Spectrometry (LC-MS)-based proteomics of synaptosomes isolated from the ipsilateral hemispheres of mice subjected to experimental stroke at different time points (24 h, 4 and 7 days) and compared them to sham-operated mice. Proteomic analyses indicated that, among the differentially expressed proteins between the two groups, cystatin C (CysC) was significantly increased at 24 h and 4 days following stroke, before returning to steady-state levels at 7 days, thus indicating a potential transient and intrinsic rescue mechanism attempt of neurons. When CysC was applied to primary neuronal cultures subjected to an in vitro model of ischemic damage, this treatment significantly improved the preservation of synaptic structures. Notably, similar effects were observed when CysC was loaded into brain-derived extracellular vesicles (BDEVs). Finally, when CysC contained in BDEVs was administered intracerebroventricularly to stroked mice, it significantly increased the expression of synaptic markers such as SNAP25, Homer-1, and NCAM in the penumbra area compared to the group supplied with empty BDEVs. Thus, we show that CysC-loaded BDEVs promote synaptic protection after ischemic damage in vitro and in vivo, opening the possibility of a therapeutic use in stroke patients.

An overview of challenges associated with exosomal miRNA isolation toward liquid biopsy-based ovarian cancer detection

As one of the deadliest gynaecological cancers, ovarian cancer has been on the list. With lesser-known symptoms and lack of an accurate detection method, it is still difficult to catch it early. In terms of both the diagnosis and outlook for cancer, liquid biopsy has come a long way with significant advancements. Exosomes, extracellular components commonly shed by cancerous cells, are nucleic acid-rich particles floating in almost all body fluids and hold enormous promise, leading to minimallyinvasive molecular diagnostics. They have been shown as potential biomarkers in liquid biopsy, being implicated in tumour growth and metastasis. In order to address the drawbacks of ovarian cancer tumor heterogeneity, a liquid biopsy-based approach is being investigated by detecting cell-free nucleic acids, particularly non-coding RNAs, having the advantage of being less invasive and more prominent in nature. microRNAs are known to actively contribute to cancer development and their existence inside exosomes has also been made quite apparent which can be leveraged to diagnose and treat the disease. Extraction of miRNAs and exosomes is an arduous execution, and while other approaches have been investigated, none have produced results that are as encouraging due to limits in time commitment, yield, and, most significantly, damage to the exosomal structure resulting discrepancies in miRNA-based expression profiling for disease diagnosis. We have briefly outlined and reviewed the difficulties with exosome isolation techniques and the need for their standardization. The several widely used procedures and their drawbacks in terms of the exosomal purity they may produce have also been outlined.

PD-1/CD80+ small extracellular vesicles from immunocytes induce cold tumours featured with enhanced adaptive immunosuppression

Only a minority of cancer patients benefit from immune checkpoint blockade therapy. Sophisticated cross-talk among different immune checkpoint pathways as well as interaction pattern of immune checkpoint molecules carried on circulating small extracellular vesicles (sEV) might contribute to the low response rate. Here we demonstrate that PD-1 and CD80 carried on immunocyte-derived sEVs (I-sEV) induce an adaptive redistribution of PD-L1 in tumour cells. The resulting decreased cell membrane PD-L1 expression and increased sEV PD-L1 secretion into the circulation contribute to systemic immunosuppression. PD-1/CD80+ I-sEVs also induce downregulation of adhesion- and antigen presentation-related molecules on tumour cells and impaired immune cell infiltration, thereby converting tumours to an immunologically cold phenotype. Moreover, synchronous analysis of multiple checkpoint molecules, including PD-1, CD80 and PD-L1, on circulating sEVs distinguishes clinical responders from those patients who poorly respond to anti-PD-1 treatment. Altogether, our study shows that sEVs carry multiple inhibitory immune checkpoints proteins, which form a potentially targetable adaptive loop to suppress antitumour immunity.

M2 Microglial Extracellular Vesicles Attenuated Blood-brain Barrier Disruption via MiR-23a-5p in Cerebral Ischemic Mice

Protecting the integrity of the blood-brain barrier (BBB) is crucial for maintaining brain homeostasis after ischemic stroke. Previous studies showed that M2 microglial extracellular vesicles (EVs) played a neuroprotective role in cerebral ischemia. However, the role of M2 microglial EVs in maintaining BBB integrity is unclear. Therefore, we explored the mechanisms of M2 microglial EVs in regulating BBB integrity. To identify microglial EVs, we used nanoparticle tracking analysis, transmission electron microscopy, and western blot analysis. Adult male ICR mice were subjected to 90-min middle cerebral artery occlusion (MCAO), followed by the injection of PKH26-labeled M2 microglial EVs via the tail vein. After MCAO, we assessed brain infarct and edema volume, as well as modified neurological severity score. BBB integrity was measured by assessing IgG leakage. The effects of M2 microglial EVs on astrocytes and endothelial cells were also examined. To investigate the molecular mechanisms, we performed RNA sequencing, miR-23a-5p knockdown, and luciferase reporter assays. Our results showed that PKH26-labeled microglial EVs were mainly taken up by neurons and glial cells. M2 microglial EVs treatment decreased brain infarct and edema volume, modified neurological severity score, and IgG leakage, while increasing the ZO-1, occludin, and claudin-5 expression after MCAO. Knockdown of miR-23a-5p reversed these effects. RNA sequencing revealed that the TNF, MMP3 and NFκB signaling pathway involved in regulating BBB integrity. Luciferase reporter assay showed that miR-23a-5p could bind to the 3' UTR of TNF. M2 microglial EVs-derived miR-23a-5p decreased TNF, MMP3 and NFκB p65 expression in astrocytes after oxygen-glucose deprivation, thereby increasing ZO-1 and Claudin-5 expression in bEnd.3 cells. In conclusion, our findings demonstrated that M2 microglial EVs attenuated BBB disruption after cerebral ischemia by delivering miR-23a-5p, which targeted TNF and regulated MMP3 and NFκB p65 expression.

Apolipoprotein E2 Expression Alters Endosomal Pathways in a Mouse Model With Increased Brain Exosome Levels During Aging

The polymorphic APOE gene is the greatest genetic determinant of sporadic Alzheimer's disease risk: the APOE4 allele increases risk, while the APOE2 allele is neuroprotective compared with the risk-neutral APOE3 allele. The neuronal endosomal system is inherently vulnerable during aging, and APOE4 exacerbates this vulnerability by driving an enlargement of early endosomes and reducing exosome release in the brain of humans and mice. We hypothesized that the protective effects of APOE2 are, in part, mediated through the endosomal pathway. Messenger RNA analyses showed that APOE2 leads to an enrichment of endosomal pathways in the brain when compared with both APOE3 and APOE4. Moreover, we show age-dependent alterations in the recruitment of key endosomal regulatory proteins to vesicle compartments when comparing APOE2 to APOE3. In contrast to the early endosome enlargement previously shown in Alzheimer's disease and APOE4 models, we detected similar morphology and abundance of early endosomes and retromer-associated vesicles within cortical neurons of aged APOE2 targeted-replacement mice compared with APOE3. Additionally, we observed increased brain extracellular levels of endosome-derived exosomes in APOE2 compared with APOE3 mice during aging, consistent with enhanced endosomal cargo clearance by exosomes to the extracellular space. Our findings thus demonstrate that APOE2 enhances an endosomal clearance pathway, which has been shown to be impaired by APOE4 and which may be protective due to APOE2 expression during brain aging.

Exosomal noncoding RNAs in gynecological cancers: implications for therapy resistance and biomarkers

Gynecologic cancers, including ovarian cancer (OC), cervical cancer (CC), and endometrial cancer (EC), pose a serious threat to women's health and quality of life due to their high incidence and lethality. Therapeutic resistance in tumors refers to reduced sensitivity of tumor cells to therapeutic drugs or radiation, which compromises the efficacy of treatment or renders it ineffective. Therapeutic resistance significantly contributes to treatment failure in gynecologic tumors, although the specific molecular mechanisms remain unclear. Exosomes are nanoscale vesicles released and received by distinct kinds of cells. Exosomes contain proteins, lipids, and RNAs closely linked to their origins and functions. Recent studies have demonstrated that exosomal ncRNAs may be involved in intercellular communication and can modulate the progression of tumorigenesis, aggravation and metastasis, tumor microenvironment (TME), and drug resistance. Besides, exosomal ncRNAs also have the potential to become significant diagnostic and prognostic biomarkers in various of diseases. In this paper, we reviewed the biological roles and mechanisms of exosomal ncRNAs in the drug resistance of gynecologic tumors, as well as explored the potential of exosomal ncRNAs acting as the liquid biopsy molecular markers in gynecologic cancers.