Systemic Exosomal Delivery of shRNA Minicircles Prevents Parkinsonian Pathology

Nature's carriers: leveraging extracellular vesicles for targeted drug delivery

With the rapid development of drug delivery systems, extracellular vesicles (EVs) have emerged as promising stars for improving targeting abilities and realizing effective delivery. Numerous studies have shown when compared to conventional strategies in targeted drug delivery (TDD), EVs-based strategies have several distinguished advantages besides targeting, such as participating in cell-to-cell communications and immune response, showing high biocompatibility and stability, penetrating through biological barriers, etc. In this review, we mainly focus on the mass production of EVs including the challenges and strategies for scaling up EVs production in a cost-effective and reproducible manner, the loading and active targeting methods, and examples of EVs as vehicles for TDD in consideration of potential safety and regulatory issues associated. We also conclude and discuss the rigor and reproducibility of EVs production, the current research status of the application of EVs-based strategies to targeted drug delivery, clinical conversion prospects, and existing chances and challenges.

Extracellular vesicles transport RNA between cells: Unraveling their dual role in diagnostics and therapeutics

Modern methods of molecular diagnostics and therapy have revolutionized the field of medicine in recent years by providing more precise and effective tools for detecting and treating diseases. This progress includes a growing exploration of the body's secreted vesicles, known as extracellular vesicles (EVs), for both diagnostic and therapeutic purposes. EVs are a heterogeneous population of lipid bilayer vesicles secreted by almost every cell type studied so far. They are detected in body fluids and conditioned culture media from living cells. EVs play a crucial role in communication between cells and organs, both locally and over long distances. They are recognized for their ability to transport endogenous RNA and proteins between cells, including messenger RNA (mRNA), microRNA (miRNA), misfolded neurodegenerative proteins, and several other biomolecules. This review explores the dual utilization of EVs, serving not only for diagnostic purposes but also as a platform for delivering therapeutic molecules to cells and tissues. Through an exploration of their composition, biogenesis, and selective cargo packaging, we elucidate the intricate mechanisms behind RNA transport between cells via EVs, highlighting their potential use for both diagnostic and therapeutic applications. Finally, it addresses challenges and outlines prospective directions for the clinical utilization of EVs.

Mmu-let-7a-5p inhibits macrophage apoptosis by targeting CASP3 to increase bacterial load and facilities mycobacterium survival

We have been trying to find a miRNA that can specifically regulate the function of mycobacterial host cells to achieve the purpose of eliminating Mycobacterium tuberculosis. The purpose of this study is to investigate the regulation of mmu-let-7a-5p on macrophages apoptosis and its effect on intracellular BCG clearance. After a series of in vitro experiments, we found that mmu-let-7a-5p could negatively regulate the apoptosis of macrophages by targeting Caspase-3. The extrinsic apoptosis signal axis TNFR1/FADD/Caspase-8/Caspase-3 was inhibited after BCG infection. Up-regulated the expression level of mmu-let-7a-5p increase the cell proliferation viability and inhibit apoptosis rate of macrophages, but down-regulated its level could apparently reduce the bacterial load of intracellular Mycobacteria and accelerate the clearance of residual Mycobacteria effectively. Mmu-let-7a-5p has great potential to be utilized as an optimal candidate exosomal loaded miRNA for anti-tuberculosis immunotherapy in our subsequent research.

Exosomes: A Cellular Communication Medium That Has Multiple Effects On Brain Diseases

Exosomes, as membranous vesicles generated by multiple cell types and secreted to extracellular space, play a crucial role in a range of brain injury-related brain disorders by transporting diverse proteins, RNA, DNA fragments, and other functional substances. The nervous system's pathogenic mechanisms are complicated, involving pathological processes like as inflammation, apoptosis, oxidative stress, and autophagy, all of which result in blood-brain barrier damage, cognitive impairment, and even loss of normal motor function. Exosomes have been linked to the incidence and progression of brain disorders in recent research. As a result, a thorough knowledge of the interaction between exosomes and brain diseases may lead to the development of more effective therapeutic techniques that may be implemented in the clinic. The potential role of exosomes in brain diseases and the crosstalk between exosomes and other pathogenic processes were discussed in this paper. Simultaneously, we noted the delicate events in which exosomes as a media allow the brain to communicate with other tissues and organs in physiology and disease, and compiled a list of natural compounds that modulate exosomes, in order to further improve our understanding of exosomes and propose new ideas for treating brain disorders.

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.

Small Scale, Big Impact: Nanotechnology-Enhanced Drug Delivery for Brain Diseases

Central nervous system (CNS) diseases, ranging from brain cancers to neurodegenerative disorders like dementia and acute conditions such as strokes, have been heavily burdening healthcare and have a direct impact on patient quality of life. A significant hurdle in developing effective treatments is the presence of the blood-brain barrier (BBB), a highly selective barrier that prevents most drugs from reaching the brain. The tight junctions and adherens junctions between the endothelial cells and various receptors expressed on the cells make the BBB form a nonfenestrated and highly selective structure that is crucial for brain homeostasis but complicates drug delivery. Nanotechnology offers a novel pathway to circumvent this barrier, with nanoparticles engineered to ferry drugs across the BBB, protect drugs from degradation, and deliver medications to the designated area. After years of development, nanoparticle optimization, including sizes, shapes, surface modifications, and targeting ligands, can enable nanomaterials tailored to specific brain drug delivery settings. Moreover, smart nano drug delivery systems can respond to endogenous and exogenous stimuli that control subsequent drug release. Here, we address the importance of the BBB in brain disease treatment, summarize different delivery routes for brain drug delivery, discuss the cutting-edge nanotechnology-based strategies for brain drug delivery, and further offer valuable insights into how these innovations in nanoparticle technology could revolutionize the treatment of CNS diseases, presenting a promising avenue for noninvasive, targeted therapeutic interventions.

Exosomes as therapeutic and drug delivery vehicle for neurodegenerative diseases

Neurodegenerative disorders are complex, progressive, and life-threatening. They cause mortality and disability for millions of people worldwide. Appropriate treatment for neurodegenerative diseases (NDs) is still clinically lacking due to the presence of the blood-brain barrier (BBB). Developing an effective transport system that can cross the BBB and enhance the therapeutic effect of neuroprotective agents has been a major challenge for NDs. Exosomes are endogenous nano-sized vesicles that naturally carry biomolecular cargoes. Many studies have indicated that exosome content, particularly microRNAs (miRNAs), possess biological activities by targeting several signaling pathways involved in apoptosis, inflammation, autophagy, and oxidative stress. Exosome content can influence cellular function in healthy or pathological ways. Furthermore, since exosomes reflect the features of the parental cells, their cargoes offer opportunities for early diagnosis and therapeutic intervention of diseases. Exosomes have unique characteristics that make them ideal for delivering drugs directly to the brain. These characteristics include the ability to pass through the BBB, biocompatibility, stability, and innate targeting properties. This review emphasizes the role of exosomes in alleviating NDs and discusses the associated signaling pathways and molecular mechanisms. Furthermore, the unique biological features of exosomes, making them a promising natural transporter for delivering various medications to the brain to combat several NDs, are also discussed.

Exosome-derived microRNAs: emerging players in vitiligo

Exosome-derived microRNAs (miRNAs) are biomacromolecules and nanoscale extracellular vesicles originating from intracellular compartments that are secreted by most cells into the extracellular space. This review examines the formation and function of exosomal miRNAs in biological information transfer, explores the pathogenesis of vitiligo, and highlights the relationship between exosomal miRNAs and vitiligo. The aim is to deepen the understanding of how exosomal miRNAs influence immune imbalance, oxidative stress damage, melanocyte-keratinocyte interactions, and melanogenesis disorders in the development of vitiligo. This enhanced understanding may contribute to the development of potential diagnostic and therapeutic options for vitiligo.

Bibliometric and visualized analysis of the applications of exosomes based drug delivery

Exosomes, endogenous vesicles secreted by cells, possess unique properties like high biocompatibility, low immunogenicity, targeting ability, long half-life, and blood-brain barrier permeability. They serve as crucial intercellular communication vectors in physiological processes and disease occurrence. Our comprehensive analysis of exosome-based drug delivery research from 2013 to 2023 revealed 2,476 authors from 717 institutions across 33 countries. Keyword clustering identified five research areas: drug delivery, mesenchymal stem cells, cancer immunotherapy, targeting ligands, surface modifications, and macrophages. The combination of exosome drug delivery technology with a proven clinical model enables the precise targeting of tumors with chemotherapy or radiosensitising agents, as well as facilitating gene therapy. This bibliometric analysis aims to characterize the current state and advance the clinical application of exosome-based drug delivery systems.

Most recent advances and applications of extracellular vesicles in tackling neurological challenges

Over the past few decades, there has been a notable increase in the global burden of central nervous system (CNS) diseases. Despite advances in technology and therapeutic options, neurological and neurodegenerative disorders persist as significant challenges in treatment and cure. Recently, there has been a remarkable surge of interest in extracellular vesicles (EVs) as pivotal mediators of intercellular communication. As carriers of molecular cargo, EVs demonstrate the ability to traverse the blood-brain barrier, enabling bidirectional communication. As a result, they have garnered attention as potential biomarkers and therapeutic agents, whether in their natural form or after being engineered for use in the CNS. This review article aims to provide a comprehensive introduction to EVs, encompassing various aspects such as their diverse isolation methods, characterization, handling, storage, and different routes for EV administration. Additionally, it underscores the recent advances in their potential applications in neurodegenerative disorder therapeutics. By exploring their unique capabilities, this study sheds light on the promising future of EVs in clinical research. It considers the inherent challenges and limitations of these emerging applications while incorporating the most recent updates in the field.

Plasma exosomes carrying mmu-miR-146a-5p and Notch signalling pathway-mediated synaptic activity in schizophrenia

BACKGROUND

Schizophrenia is characterized by a complex interplay of genetic and environmental factors, leading to alterations in various molecular pathways that may contribute to its pathogenesis. Recent studies have shown that exosomal microRNAs could play essential roles in various brain disorders; thus, we sought to explore the potential molecular mechanisms through which microRNAs in plasma exosomes are involved in schizophrenia.

METHODS

We obtained sequencing data sets (SUB12404730, SUB12422862, and SUB12421357) and transcriptome sequencing data sets (GSE111708, GSE108925, and GSE18981) from mouse models of schizophrenia using the Sequence Read Archive and the Gene Expression Omnibus databases, respectively. We performed differential expression analysis on mRNA to identify differentially expressed genes. We conducted Gene Ontology (GO) functional and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses to determine differentially expressed genes. Subsequently, we determined the intersection of differentially expressed microRNAs in plasma exosomes and in prefrontal cortex tissue. We retrieved downstream target genes of mmu-miR-146a-5p from TargetScan and used Cytoscape to visualize and map the microRNA-target gene regulatory network. We conducted in vivo experiments using MK-801-induced mouse schizophrenia models and in vitro experiments using cultured mouse neurons. The role of plasma exosomal miR-146a-5p in schizophrenia was validated using a cell counting kit, detection of lactate dehydrogenase, dual-luciferase assay, quantitative reverse transcription polymerase chain reaction, and Western blot analysis.

RESULTS

Differential genes were mainly enriched in synaptic regulation-related functions and pathways and were associated with neuronal degeneration. We found that mmu-miR-146a-5p was highly expressed in both prefrontal cortical tissue and plasma exosomes, which may be transferred to lobe cortical vertebral neurons, leading to the synergistic dysregulation of gene network functions and, therefore, promoting schizophrenia development. We found that mmu-miR-146a-5p may inhibit the Notch signalling pathway-mediated synaptic activity of mouse pyramidal neurons in the lobe cortex by targeting NOTCH1, which in turn could promote the onset and development of schizophrenia in mice.

LIMITATIONS

The study's findings are based on animal models and in vitro experiments, which may not fully replicate the complexity of human schizophrenia.

CONCLUSION

Our findings suggest that mmu-miR-146a-5p in plasma-derived exosomes may play an important role in the pathogenesis of schizophrenia. Our results provide new insights into the underlying molecular mechanisms of the disease.

An Overview on the Physiopathology of the Blood-Brain Barrier and the Lipid-Based Nanocarriers for Central Nervous System Delivery

The state of well-being and health of our body is regulated by the fine osmotic and biochemical balance established between the cells of the different tissues, organs, and systems. Specific districts of the human body are defined, kept in the correct state of functioning, and, therefore, protected from exogenous or endogenous insults of both mechanical, physical, and biological nature by the presence of different barrier systems. In addition to the placental barrier, which even acts as a linker between two different organisms, the mother and the fetus, all human body barriers, including the blood-brain barrier (BBB), blood-retinal barrier, blood-nerve barrier, blood-lymph barrier, and blood-cerebrospinal fluid barrier, operate to maintain the physiological homeostasis within tissues and organs. From a pharmaceutical point of view, the most challenging is undoubtedly the BBB, since its presence notably complicates the treatment of brain disorders. BBB action can impair the delivery of chemical drugs and biopharmaceuticals into the brain, reducing their therapeutic efficacy and/or increasing their unwanted bioaccumulation in the surrounding healthy tissues. Recent nanotechnological innovation provides advanced biomaterials and ad hoc customized engineering and functionalization methods able to assist in brain-targeted drug delivery. In this context, lipid nanocarriers, including both synthetic (liposomes, solid lipid nanoparticles, nanoemulsions, nanostructured lipid carriers, niosomes, proniosomes, and cubosomes) and cell-derived ones (extracellular vesicles and cell membrane-derived nanocarriers), are considered one of the most successful brain delivery systems due to their reasonable biocompatibility and ability to cross the BBB. This review aims to provide a complete and up-to-date point of view on the efficacy of the most varied lipid carriers, whether FDA-approved, involved in clinical trials, or used in in vitro or in vivo studies, for the treatment of inflammatory, cancerous, or infectious brain diseases.

Research progress on astrocyte-derived extracellular vesicles in the pathogenesis and treatment of neurodegenerative diseases

Neurodegenerative disorders, including Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), and Huntington's disease (HD), pose significant global health risks and represent a substantial public health concern in the contemporary era. A primary factor in the pathophysiology of these disorders is aberrant accumulation and aggregation of pathogenic proteins within the brain and spinal cord. Recent investigations have identified extracellular vesicles (EVs) in the central nervous system (CNS) as potential carriers for intercellular transport of misfolded proteins associated with neurodegenerative diseases. EVs are involved in pathological processes that contribute to various brain disorders including neurodegenerative disorders. Proteins linked to neurodegenerative disorders are secreted and distributed from cell to cell via EVs, serving as a mechanism for direct intercellular communication through the transfer of biomolecules. Astrocytes, as active participants in CNS intercellular communication, release astrocyte-derived extracellular vesicles (ADEVs) that are capable of interacting with diverse target cells. This review primarily focuses on the involvement of ADEVs in the development of neurological disorders and explores their potential dual roles - both advantageous and disadvantageous in the context of neurological disorders. Furthermore, this review examines the current studies investigating ADEVs as potential biomarkers for the diagnosis and treatment of neurodegenerative diseases. The prospects and challenges associated with the application of ADEVs in clinical settings were also comprehensively reviewed.

Extracellular Vesicles as Next-Generation Diagnostics and Advanced Therapy Medicinal Products

Extracellular vesicles (EVs) hold great promise for clinical application as new diagnostic and therapeutic modalities. This paper describes major GMP-based upstream and downstream manufacturing processes for EV large-scale production, also focusing on post-processing technologies such as surface bioengineering and uploading studies to yield novel EV-based diagnostics and advanced therapy medicinal products. This paper also focuses on the quality, safety, and efficacy issues of the bioengineered EV drug candidates before first-in-human studies. Because clinical trials involving extracellular vesicles are on the global rise, this paper encompasses different clinical studies registered on clinical-trial register platforms, with varying levels of advancement, highlighting the growing interest in EV-related clinical programs. Navigating the regulatory affairs of EVs poses real challenges, and obtaining marketing authorization for EV-based medicines remains complex due to the lack of specific regulatory guidelines for such novel products. This paper discusses the state-of-the-art regulatory knowledge to date on EV-based diagnostics and medicinal products, highlighting further research and global regulatory needs for the safe and reliable implementation of bioengineered EVs as diagnostic and therapeutic tools in clinical settings. Post-marketing pharmacovigilance for EV-based medicinal products is also presented, mainly addressing such topics as risk assessment and risk management.

An Overview of Epigenetic Changes in the Parkinson's Disease Brain

Parkinson's disease is a progressive neurodegenerative disorder, predominantly of the motor system. Although some genetic components and cellular mechanisms of Parkinson's have been identified, much is still unknown. In recent years, emerging evidence has indicated that non-DNA-sequence variation (in particular epigenetic mechanisms) is likely to play a crucial role in the development and progression of the disease. Here, we present an up-to-date overview of epigenetic processes including DNA methylation, DNA hydroxymethylation, histone modifications and non-coding RNAs implicated in the brain of those with Parkinson's disease. We will also discuss the limitations of current epigenetic research in Parkinson's disease, the advantages of simultaneously studying genetics and epigenetics, and putative novel epigenetic therapies.

The mechanistic view of non-coding RNAs as a regulator of inflammatory pathogenesis of Parkinson's disease

Parkinson's disease (PD) is a neurodegenerative disorder characterized by the progressive loss of dopaminergic neurons in the substantia nigra pars compacta, leading to motor and non-motor symptoms. Emerging evidence suggests that inflammation plays a crucial role in the pathogenesis of PD, with the NLRP3 inflammasome implicated as a key mediator. Nfon-coding RNAs (ncRNAs), including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), have recently garnered attention for their regulatory roles in various biological processes, including inflammation. This review aims to provide a mechanistic insight into how ncRNAs function as regulators of inflammatory pathways in PD, with a specific focus on the NLRP3 inflammasome. We discuss the dysregulation of miRNAs and lncRNAs in PD pathogenesis and their impact on neuroinflammation through modulation of NLRP3 activation, cytokine production, and microglial activation. Additionally, we explore the crosstalk between ncRNAs, alpha-synuclein pathology, and mitochondrial dysfunction, further elucidating the intricate network underlying PD-associated inflammation. Understanding the mechanistic roles of ncRNAs in regulating inflammatory pathways may offer novel therapeutic targets for the treatment of PD and provide insights into the broader implications of ncRNA-mediated regulation in neuroinflammatory diseases.

Exosomes for neurodegenerative diseases: diagnosis and targeted therapy

PURPOSE OF REVIEW

Neurodegenerative diseases are still challenging clinical issues, with no curative interventions available and early, accurate diagnosis remaining difficult. Finding solutions to them is of great importance. In this review, we discuss possible exosomal diagnostic biomarkers and explore current explorations in exosome-targeted therapy for some common neurodegenerative diseases, offering insights into the clinical transformation of exosomes in this field.

RECENT FINDINGS

The burgeoning research on exosomes has shed light on their potential applications in disease diagnosis and treatment. As a type of extracellular vesicles, exosomes are capable of crossing the blood - brain barrier and exist in various body fluids, whose components can reflect pathophysiological changes in the brain. In addition, they can deliver specific drugs to brain tissue, and even possess certain therapeutic effects themselves. And the recent advancements in engineering modification technology have further enabled exosomes to selectively target specific sites, facilitating the possibility of targeted therapy for neurodegenerative diseases. The unique properties of exosomes give them great potential in the diagnosis and treatment of neurodegenerative diseases, and provide novel ideas for dealing with such diseases.

Exosome-Based Macromolecular neurotherapeutic drug delivery approaches in overcoming the Blood-Brain barrier for treating brain disorders

Delivering drugs to the brain is a complex challenge in medical research, particularly for disorders like Alzheimer's and Parkinson's. The blood-brain barrier restricts the entry of many therapeutic molecules, hindering their effectiveness. Nanoparticles, a potential solution, face issues like toxicity and limited approvals. A new avenue explores the use of small extracellular vesicles (sEVs), i.e., exosomes, as natural carriers for drug delivery. sEVs, tiny structures below 150 nm, show promise due to their minimal immune response and ability to precisely deliver drugs. This review focuses on the potential of sEVs-based drug delivery systems for treating neurological disorders, brain cancers, and other brain-related issues. Notably, bioengineered sEVs-carrying therapeutic compounds exhibit promise in early studies. The unique features of sEVs, such as their small size and natural properties, position them as candidates to overcome challenges in drug delivery to the brain. Ongoing clinical trials and research into sEVs behavior within the body further highlight their potential for revolutionizing drug delivery and addressing complex brain conditions.

Advanced nanoparticle strategies for optimizing RNA therapeutic delivery in neurodegenerative disorders

Neurodegenerative diseases affect many people worldwide, and as the population ages, the incidence of these conditions increases. Alzheimer's disease (AD) and Parkinson's disease (PD) are the most prevalent neurodegenerative disorders worldwide. Different medicines are being used to control symptoms related to these conditions, but no treatment has yet been approved. Both genetic and environmental factors are involved in disease pathogenesis, and research on the pathophysiological pathways is still ongoing. The role of subcellular pathways and dysregulation in RNA pathways has been highlighted in pathophysiological studies, and treatment strategies focused on these pathways can be a promising approach. Many experiments have been conducted on delivering RNA cargo to the CNS to modulate various pathways involved. Yet another challenge to be faced is the effective transport of desired molecules to targets, which can be greatly hindered by distinct barriers limiting transport to the CNS, most noticeably the blood-brain barrier (BBB). Nanotechnology and the use of different nano-carriers for the delivery of nucleotides, peptides, proteins, and drug molecules are currently of great interest as these carriers help with better delivery and protection and, as a result, improve the effectiveness of the cargo. Nanocarriers can protect susceptible RNA molecules from possible degradation or destruction and improve their ability to reach the brain by enhancing BBB penetration. Different mechanisms for this process have been hypothesized. This review will go through the therapeutic application of RNA molecules in the treatment of AD and PD and the role of nanocarriers in overcoming delivery challenges and enhancing efficacy.

Gut microbiota produces biofilm-associated amyloids with potential for neurodegeneration

Age-related neurodegenerative diseases involving amyloid aggregation remain one of the biggest challenges of modern medicine. Alterations in the gastrointestinal microbiome play an active role in the aetiology of neurological disorders. Here, we dissect the amyloidogenic properties of biofilm-associated proteins (BAPs) of the gut microbiota and their implications for synucleinopathies. We demonstrate that BAPs are naturally assembled as amyloid-like fibrils in insoluble fractions isolated from the human gut microbiota. We show that BAP genes are part of the accessory genomes, revealing microbiome variability. Remarkably, the abundance of certain BAP genes in the gut microbiome is correlated with Parkinson's disease (PD) incidence. Using cultured dopaminergic neurons and Caenorhabditis elegans models, we report that BAP-derived amyloids induce α-synuclein aggregation. Our results show that the chaperone-mediated autophagy is compromised by BAP amyloids. Indeed, inoculation of BAP fibrils into the brains of wild-type mice promote key pathological features of PD. Therefore, our findings establish the use of BAP amyloids as potential targets and biomarkers of α-synucleinopathies.

A vivid outline demonstrating the benefits of exosome-mediated drug delivery in CNS-associated disease environments

The efficacy of drug delivery mechanisms has been improvised with time for different therapeutic purposes. In most cases, nano-sized delivery systems have been modeled over decades for the on-target applicability of the drugs. The use of synthetic drug delivery materials has been a common practice, although research has now focussed more on using natural vehicles, to avoid the side effects of synthetic delivery systems and easy acceptance by the body. Exosome is such a natural nano-sized vehicle that exceeds the efficiency of many natural vehicles, for being immune-friendly, due to its origin. Unlike, other natural drug delivery systems, exosomes are originated within the body's cells, and from there, they happen to travel through the extracellular matrices into neighboring cells. This capacity of exosomes has made them an efficient drug delivery system over recent years and now a large number of researches have been carried out to develop exosomes as natural drug delivery vehicles. Several experimental strategies have been practiced in this regard which have shown that exosomes are exclusively capable of carrying drugs and they can also be used in targeted delivery, for which they efficiently can reach and release the drug at their target cells for consecutive effects. One of the most interesting features of exosomes is they can cross the blood-brain barrier (BBB) in the body and hence, for the disease where other delivery vehicles are incapable of reaching the destination of the drug, exosomes can overcome the hurdle. This review particularly, focuses on the different aspects of using exosomes as a potential nano-sized drug delivery system for some of the severe diseases associated with the central nervous system of the human body.

Extracellular Vesicles: The Invisible Heroes and Villains of COVID-19 Central Neuropathology

Acknowledging the neurological symptoms of COVID-19 and the long-lasting neurological damage even after the epidemic ends are common, necessitating ongoing vigilance. Initial investigations suggest that extracellular vesicles (EVs), which assist in the evasion of the host's immune response and achieve immune evasion in SARS-CoV-2 systemic spreading, contribute to the virus's attack on the central nervous system (CNS). The pro-inflammatory, pro-coagulant, and immunomodulatory properties of EVs contents may directly drive neuroinflammation and cerebral thrombosis in COVID-19. Additionally, EVs have attracted attention as potential candidates for targeted therapy in COVID-19 due to their innate homing properties, low immunogenicity, and ability to cross the blood-brain barrier (BBB) freely. Mesenchymal stromal/stem cell (MSCs) secreted EVs are widely applied and evaluated in patients with COVID-19 for their therapeutic effect, considering the limited antiviral treatment. This review summarizes the involvement of EVs in COVID-19 neuropathology as carriers of SARS-CoV-2 or other pathogenic contents, as predictors of COVID-19 neuropathology by transporting brain-derived substances, and as therapeutic agents by delivering biotherapeutic substances or drugs. Understanding the diverse roles of EVs in the neuropathological aspects of COVID-19 provides a comprehensive framework for developing, treating, and preventing central neuropathology and the severe consequences associated with the disease.

Ultrasound image-guided cancer gene therapy using iRGD dual-targeted magnetic cationic microbubbles

The gene therapy attracted more and more attention for the tumor therapy. To obtain a safe gene therapy system, the new gene vectors beyond the virus were developed for a high gene therapy efficiency. The ultrasound mediated gene therapy was safer and the plasmid DNA could be delivered by the microbubbles and combined with the ultrasound to increase the gene transfection efficiency. In this work, the cationic microbubbles decorated with Cyclo(Cys-Arg-Gly-Asp-Lys-Gly-Pro-AspCys) (iRGD peptides) and magnetic Fe3O4 nanoparticles (MBiM) was designed for targeted ultrasound contrast imaging guided gene therapy of tumors. The ultrasound image intensity was dramatically enhanced at the tumor site that received MBiM with the magnet applied, compared to those administrated the non-targeted microbubbles (MBb) or the microbubbles with only one target material on the surface (MBM and MBbi). The pGPU6/GFP/Neo-shAKT2 was used as a sample gene, which down regulate the AKT2 protein expression for the cancer therapy. It illustrated that MBiM/AKT2 had the highest gene transfection efficiency in the studied microbubbles mediated by the ultrasound, leading to the AKT2 protein expression downregulation and the strongest tumor killing effect in vitro and in vivo. In summary, a novel and biocompatible gene delivery platform via MBiM with both the endogenous and external targeting effects for breast cancer theranostics was developed.

Lipidic Nanoparticles, Extracellular Vesicles and Hybrid Platforms as Advanced Medicinal Products: Future Therapeutic Prospects for Neurodegenerative Diseases

Neurodegenerative diseases, such as Alzheimer's and Parkinson's, affect a wide variety of the population and pose significant challenges with progressive and irreversible neural cell loss. The limitations of brain-targeting therapies and the unclear molecular mechanisms driving neurodegeneration hamper the possibility of developing successful treatment options. Thus, nanoscale drug delivery platforms offer a promising solution. This paper explores and compares lipidic nanoparticles, extracellular vesicles (EVs), and hybrid liposomal-EV nanoplatforms as advanced approaches for targeted delivery to combat neurodegeneration. Lipidic nanoparticles are well-characterized platforms that allow multi-drug loading and scalable production. Conversely, EVs offer the ability of selectively targeting specific tissues and high biocompatibility. The combination of these two platforms in one could lead to promising results in the treatment of neurodegeneration. However, many issues, such as the regulatory framework, remain to be solved before these novel products are translated into clinical practice.

Unraveling the Genetic Landscape of Neurological Disorders: Insights into Pathogenesis, Techniques for Variant Identification, and Therapeutic Approaches

Genetic abnormalities play a crucial role in the development of neurodegenerative disorders (NDDs). Genetic exploration has indeed contributed to unraveling the molecular complexities responsible for the etiology and progression of various NDDs. The intricate nature of rare and common variants in NDDs contributes to a limited understanding of the genetic risk factors associated with them. Advancements in next-generation sequencing have made whole-genome sequencing and whole-exome sequencing possible, allowing the identification of rare variants with substantial effects, and improving the understanding of both Mendelian and complex neurological conditions. The resurgence of gene therapy holds the promise of targeting the etiology of diseases and ensuring a sustained correction. This approach is particularly enticing for neurodegenerative diseases, where traditional pharmacological methods have fallen short. In the context of our exploration of the genetic epidemiology of the three most prevalent NDDs-amyotrophic lateral sclerosis, Alzheimer's disease, and Parkinson's disease, our primary goal is to underscore the progress made in the development of next-generation sequencing. This progress aims to enhance our understanding of the disease mechanisms and explore gene-based therapies for NDDs. Throughout this review, we focus on genetic variations, methodologies for their identification, the associated pathophysiology, and the promising potential of gene therapy. Ultimately, our objective is to provide a comprehensive and forward-looking perspective on the emerging research arena of NDDs.

Navigating the brain: the role of exosomal shuttles in precision therapeutics

Brain diseases have become one of the leading roots of mortality and disability worldwide, contributing a significant part of the disease burden on healthcare systems. The blood-brain barrier (BBB) is a primary physical and biological obstacle that allows only small molecules to pass through it. Its selective permeability is a significant challenge in delivering therapeutics into the brain for treating brain dysfunction. It is estimated that only 2% of the new central nervous system (CNS) therapeutic compounds can cross the BBB and achieve their therapeutic targets. Scientists are exploring various approaches to develop effective cargo delivery vehicles to promote better therapeutics targeting the brain with minimal off-target side effects. Despite different synthetic carriers, one of the natural brain cargo delivery systems, "exosomes," are now employed to transport drugs through the BBB. Exosomes are naturally occurring small extracellular vesicles (EVs) with unique advantages as a therapeutic delivery system for treating brain disorders. They have beneficial innate aspects of biocompatibility, higher stability, ability to cross BBB, low cytotoxicity, low immunogenicity, homing potential, targeted delivery, and reducing off-site target effects. In this review, we will discuss the limitations of synthetic carriers and the utilization of naturally occurring exosomes as brain-targeted cargo delivery vehicles and highlight the methods for modifying exosome surfaces and drug loading into exosomes. We will also enlist neurodegenerative disorders targeted with genetically modified exosomes for their treatment.

Extracellular Vesicles as Biomarkers for Parkinson's Disease: How Far from Clinical Translation?

Parkinson's disease (PD) is a neurodegenerative disorder affecting about 10 million people worldwide with a prevalence of about 2% in the over-80 population. The disease brings in also a huge annual economic burden, recently estimated by the Michael J Fox Foundation for Parkinson's Research to be USD 52 billion in the United States alone. Currently, no effective cure exists, but available PD medical treatments are based on symptomatic prescriptions that include drugs, surgical approaches and rehabilitation treatment. Due to the complex biology of a PD brain, the design of clinical trials and the personalization of treatment strategies require the identification of accessible and measurable biomarkers to monitor the events induced by treatment and disease progression and to predict patients' responsiveness. In the present review, we strive to briefly summarize current knowledge about PD biomarkers, focusing on the role of extracellular vesicles as active or involuntary carriers of disease-associated proteins, with particular attention to those research works that envision possible clinical applications.

Role of lysosome in healing neurological disorders by nano-bioengineering

Lysosomes primarily recognized as center for cellular 'garbage-disposing-unit', which has recently emerged as a crucial regulator of cellular metabolism. This organelle is a well-known vital player in the pathology including neurodegenerative disorders. In pathological context, removal of intracellular damaged misfolded proteins, organelles and aggregates are ensured by 'Autophagy' pathway, which initially recognizes, engulfs and seals the toxic cargo at the cytosolic environment. Thereafter the cell completes the task of encapsulated cargo elimination upon delivery of them to the terminal compartment - lysosome, which contains acid hydrolases, that are capable of degrading the abnormal protein-lipid-repertoire. The merge between inseparable 'Autophagy' and 'Lysosomal' pathways evolved into 'Autophagy-Lysosome Pathway (ALP)', through which cell ultimately degrades and recycles bio-materials for metabolic needs. Dysregulation of any of the steps of the multi-step ALP can contribute to the development and progression of disorders including Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD). Therefore, targeting differential steps of ALP or directly lysosomes using nano-bioengineering approaches holds great promise for therapeutic interventions. This review aims to explore the role of distal autophagy pathway and proximal lysosomal function, as cellular degradative and metabolic hubs, in healing neurological disorders and highlights the contributions of nano-bioengineering in this field. Despite multiple challenges, this review underscores the immense potential of integrating autophagy-lysosomal biology with nano-bioengineering to revolutionize the field and provide novel therapeutic avenues for tackling neurological-neurodegenerative-disorders.

Unraveling the Multifaceted Roles of Extracellular Vesicles: Insights into Biology, Pharmacology, and Pharmaceutical Applications for Drug Delivery

Extracellular vesicles (EVs) are nanoparticles released from various cell types that have emerged as powerful new therapeutic option for a variety of diseases. EVs are involved in the transmission of biological signals between cells and in the regulation of a variety of biological processes, highlighting them as potential novel targets/platforms for therapeutics intervention and/or delivery. Therefore, it is necessary to investigate new aspects of EVs' biogenesis, biodistribution, metabolism, and excretion as well as safety/compatibility of both unmodified and engineered EVs upon administration in different pharmaceutical dosage forms and delivery systems. In this review, we summarize the current knowledge of essential physiological and pathological roles of EVs in different organs and organ systems. We provide an overview regarding application of EVs as therapeutic targets, therapeutics, and drug delivery platforms. We also explore various approaches implemented over the years to improve the dosage of specific EV products for different administration routes.

Cell Therapy for Parkinson's Disease

Parkinson's Disease (PD) is a neurodegenerative disease characterized by the progressive loss of dopaminergic neurons of the substantia nigra pars compacta with a reduction in dopamine concentration in the striatum. It is a substantial loss of dopaminergic neurons that is responsible for the classic triad of PD symptoms, i.e., resting tremor, muscular rigidity, and bradykinesia. Several current therapies for PD may only offer symptomatic relief and do not address the underlying neurodegeneration of PD. The recent developments in cellular reprogramming have enabled the development of previously unachievable cell therapies and patient-specific modeling of PD through Induced Pluripotent Stem Cells (iPSCs). iPSCs possess the inherent capacity for pluripotency, allowing for their directed differentiation into diverse cell lineages, such as dopaminergic neurons, thus offering a promising avenue for addressing the issue of neurodegeneration within the context of PD. This narrative review provides a comprehensive overview of the effects of dopamine on PD patients, illustrates the versatility of iPSCs and their regenerative abilities, and examines the benefits of using iPSC treatment for PD as opposed to current therapeutic measures. In means of providing a treatment approach that reinforces the long-term survival of the transplanted neurons, the review covers three supplementary avenues to reinforce the potential of iPSCs.

Uterine Fluid Extracellular Vesicles Proteome Is Altered During the Estrous Cycle

Uterine environment is tightly and finely regulated via various signaling pathways mediated through endocrine, exocrine, autocrine, juxtacrine, and paracrine mechanisms. In utero signaling processes are paramount for normal and abnormal physiology which involves cell to cell, cells to gametes, cells to embryo, and even interkingdom communications due to presence of uterine microbiota. Extracellular vesicles (EVs) in the uterine fluid (UF) and their cargo components are known to be mediators of in utero signaling and communications. Interestingly, the changes in UF-EV proteome during the bovine estrous cycle and the effects of these differentially enriched proteins on embryo development are yet to be fully discovered. In this study, shotgun quantitative proteomics-based mass spectrometry was employed to compare UF-EV proteomes at day 0, 7, and 16 of the estrous cycle to understand the estrous cycle-dependent dynamics. Furthermore, different phase UF-EVs were supplemented in embryo cultures to evaluate their impact on embryo development. One hundred fifty-nine UF-EV proteins were differentially enriched at different time points indicating the UF-EV proteome is cycle-dependent. Overall, many identified pathways are important for normal uterine functions, early embryo development, and its nutritional needs, such as antioxidant activity, cell morphology and cycle, cellular homeostasis, cell adhesion, and carbohydrate metabolic process. Furthermore, the luteal phase UF-EVs supplementation increased in vitro blastocyst rates from 25.0 ± 5.9% to 41.0 ± 4.0% (p ≤ 0.05). Our findings highlight the importance of bovine UF-EV in uterine communications throughout the estrous cycle. Interestingly, comparison of hormone-synchronized EV proteomes to natural cycle UF-EVs indicated shift of signaling. Finally, UF-EVs can be used to improve embryo production in vitro.

The Biology, Pathological Roles of Exosomes and Their Clinical Application in Parkinson's Disease

Parkinson's disease (PD) is a neurodegenerative disease with a high global incidence and places a great burden on the patient, their family and society. Early diagnosis of PD is the key to hindering the progression process and may enable treatment to partially reverse the disease course. Exosomes are lipid bilayers with a diameter of 40-160 nm (average ∼100 nm), show a cup-shaped structure in transmission electron microscopy (TEM) images, and contain different types of nucleic acids and proteins. On the one hand, several molecules contained in exosomes are correlated with PD pathology. On the other hand, biomarkers based on exosomes have gradually become diagnostic tools in PD. Since exosomes can freely cross the blood-brain barrier, CNS-derived exosomes obtained from the periphery have the potential to be a powerful marker for early PD diagnosis. Of course, exosomes also have great potential as drug delivery systems due to their low toxicity, lipid solubility and immunological inertness. However, there is still a lack of standardized, efficient, and ultrasensitive methods for the isolation of exosomes, hindering the development of effective biomarkers. Therefore, this review describes the biological characteristics of exosomes, exosome extraction methods, and the pathological role, diagnostic/therapeutic value of exosomes in PD.

Exosomes derived from human umbilical cord mesenchymal stem cells alleviate Parkinson's disease and neuronal damage through inhibition of microglia

Microglia-mediated inflammatory responses have been shown to play a crucial role in Parkinson's disease. In addition, exosomes derived from mesenchymal stem cells have shown anti-inflammatory effects in the treatment of a variety of diseases. However, whether they can protect neurons in Parkinson's disease by inhibiting microglia-mediated inflammatory responses is not yet known. In this study, exosomes were isolated from human umbilical cord mesenchymal stem cells and injected into a 6-hydroxydopamine-induced rat model of Parkinson's disease. We found that the exosomes injected through the tail vein and lateral ventricle were absorbed by dopaminergic neurons and microglia on the affected side of the brain, where they repaired nigral-striatal dopamine system damage and inhibited microglial activation. Furthermore, in an in vitro cell model, pretreating lipopolysaccharide-stimulated BV2 cells with exosomes reduced interleukin-1β and interleukin-18 secretion, prevented the adoption of pyroptosis-associated morphology by BV2 cells, and increased the survival rate of SH-SY5Y cells. Potential targets for treatment with human umbilical cord mesenchymal stem cells and exosomes were further identified by high-throughput microRNA sequencing and protein spectrum sequencing. Our findings suggest that human umbilical cord mesenchymal stem cells and exosomes are a potential treatment for Parkinson's disease, and that their neuroprotective effects may be mediated by inhibition of excessive microglial proliferation.

Potential applications of using tissue-specific EVs in targeted therapy and vaccinology

Many cell types secrete spherical membrane bodies classified as extracellular vesicles (EVs). EVs participate in intercellular communication and are present in body fluids, including blood, lymph, and cerebrospinal fluid. The time of EVs survival in the body varies depending on the body's localisation. Once the EVs reach cells, they trigger a cellular response. Three main modes of direct interaction of EVs with a target cell were described: receptor-ligand interaction mode, a direct fusion of EVs with the cellular membrane and EVs internalisation. Studies focused on the medical application of EVs. Medical application of EVs may require modification of their surface and interior. EVs surface was modified by affecting the parental cells or by the direct amendment of isolated EVs. The interior modification involved introducing materials into the cells or direct administrating isolated EVs. EVs carry proteins, lipids, fragments of DNA, mRNA, microRNA (miRNA) and long non-coding RNA. Because of EVs availability in liquid biopsy, they are potential diagnostic markers. Modified EVs could enhance the treatment of diseases such as colorectal cancer, Parkinson's disease, leukaemia or liver fibrosis. EVs have specific tissue tropisms, which makes them convenient organ-directed carriers of nucleic acids, drugs and vaccines. In conclusion, recently published works have shown that EVs could become biomarkers and modern vehicles of advanced drug forms.

The Involvement of Neuroinflammation in the Onset and Progression of Parkinson's Disease

Parkinson's disease is a neurodegenerative disease exhibiting the fastest growth in incidence in recent years. As with most neurodegenerative diseases, the pathophysiology is incompletely elucidated, but compelling evidence implicates inflammation, both in the central nervous system and in the periphery, in the initiation and progression of the disease, although it is not yet clear what triggers this inflammatory response and where it begins. Gut dysbiosis seems to be a likely candidate for the initiation of the systemic inflammation. The therapies in current use provide only symptomatic relief, but do not interfere with the disease progression. Nonetheless, animal models have shown promising results with therapies that target various vicious neuroinflammatory cascades. Translating these therapeutic strategies into clinical trials is still in its infancy, and a series of issues, such as the exact timing, identifying biomarkers able to identify Parkinson's disease in early and pre-symptomatic stages, or the proper indications of genetic testing in the population at large, will need to be settled in future guidelines.

Targeting the central nervous system: From synthetic nanoparticles to extracellular vesicles-Focus on Alzheimer's and Parkinson's disease

Neurodegenerative diseases (NDs) such as Alzheimer's disease (AD) and Parkinson's disease (PD) are an accelerating global health problem as life expectancy rises worldwide. Despite their significant burden in public health systems to date, the existing treatments only manage the symptoms without slowing down disease progression. Thus, the ongoing neurodegenerative process remains untreated. Moreover, the stronghold of the brain-the blood-brain barrier (BBB)-prevents drug penetrance and dwindles effective treatments. In the last years, nanotechnology-based drug delivery systems (DDS) have become a promising approach to target and treat these disorders related to the central nervous system (CNS). PLGA based nanoparticles (NPs) were the first employed DDS for effective drug delivery. However, the poor drug loading capacity and localized immunogenicity prompted the scientific community to move to another DDS such as lipid-based NPs. Despite the lipid NPs' safety and effectiveness, their off-target accumulation together with the denominated CARPA (complement activation-related pseudo allergy) reaction has limited their complete clinical translation. Recently, biological NPs naturally secreted by cells, termed as extracellular vesicles (EVs) have emerged as promising more complex biocompatible DDS. In addition, EVs act as dual players in NDs treatment, as a "cell free" therapy themselves, as well as new biological NPs with numerous characteristics that qualify them as promising carriers over synthetic DDS. The present review aims to display advantages, drawbacks, current limitations and future prospective of the previously cited synthetic and biological DDS to enter the brain and treat one of 21st century most challenging diseases, NDs. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Neurological Disease.

Combating Dopaminergic Neurodegeneration in Parkinson's Disease through Nanovesicle Technology

Parkinson's disease (PD) is characterized by dopaminergic neurodegeneration, resulting in dopamine depletion and motor behavior deficits. Since the discovery of L-DOPA, it has been the most prescribed drug for symptomatic relief in PD, whose prolonged use, however, causes undesirable motor fluctuations like dyskinesia and dystonia. Further, therapeutics targeting the pathological hallmarks of PD including α-synuclein aggregation, oxidative stress, neuroinflammation, and autophagy impairment have also been developed, yet PD treatment is a largely unmet success. The inception of the nanovesicle-based drug delivery approach over the past few decades brings add-on advantages to the therapeutic strategies for PD treatment in which nanovesicles (basically phospholipid-containing artificial structures) are used to load and deliver drugs to the target site of the body. The present review narrates the characteristic features of nanovesicles including their blood-brain barrier permeability and ability to reach dopaminergic neurons of the brain and finally discusses the current status of this technology in the treatment of PD. From the review, it becomes evident that with the assistance of nanovesicle technology, the therapeutic efficacy of anti-PD pharmaceuticals, phyto-compounds, as well as that of nucleic acids targeting α-synuclein aggregation gained a significant increment. Furthermore, owing to the multiple drug-carrying abilities of nanovesicles, combination therapy targeting multiple pathogenic events of PD has also found success in preclinical studies and will plausibly lead to effective treatment strategies in the near future.

Fibroblast exosomal TFAP2C induced by chitosan oligosaccharides promotes peripheral axon regeneration via the miR-132-5p/CAMKK1 axis

Chitosan and its degradation product, oligosaccharides, have been shown to facilitate peripheral nerve regeneration. However, the underlying mechanisms are not well understood. In this study, we analyzed the protein expression profiles in sciatic nerves after injury using proteomics. A group of proteins related to exosome packaging and transport is up-regulated by chitosan oligosaccharides (COS), implying that exosomes are involved in COS-induced peripheral nerve regeneration. In fact, exosomes derived from fibroblasts (f-EXOs) treated with COS significantly promoted axon extension and regeneration. Exosomal protein identification and functional studies, revealed that TFAP2C is a key factor in neurite outgrowth induced by COS-f-EXOs. Furthermore, we showed that TFAP2C targets the pri-miRNA-132 gene and represses miR-132-5p expression in dorsal root ganglion neurons. Camkk1 is a downstream substrate of miR-132-5p that positively affects axon extension. In rats, miR-132-5p antagomir stimulates CAMKK1 expression and improves axon regeneration and functional recovery in sciatic nerves after injury. Our data reveal the mechanism for COS in axon regeneration, that is COS induce fibroblasts to produce TFAP2C-enriched EXOs, which are then transferred into axons to promote axon regeneration via miR-132-5p/CAMKK1. Moreover, these results show a new facet of fibroblasts in axon regeneration in peripheral nerves.

Extracellular vesicles: a rising star for therapeutics and drug delivery

Extracellular vesicles (EVs) are nano-sized, natural, cell-derived vesicles that contain the same nucleic acids, proteins, and lipids as their source cells. Thus, they can serve as natural carriers for therapeutic agents and drugs, and have many advantages over conventional nanocarriers, including their low immunogenicity, good biocompatibility, natural blood-brain barrier penetration, and capacity for gene delivery. This review first introduces the classification of EVs and then discusses several currently popular methods for isolating and purifying EVs, EVs-mediated drug delivery, and the functionalization of EVs as carriers. Thereby, it provides new avenues for the development of EVs-based therapeutic strategies in different fields of medicine. Finally, it highlights some challenges and future perspectives with regard to the clinical application of EVs.

Therapeutic effects of engineered exosome-based miR-25 and miR-181a treatment in spinocerebellar ataxia type 3 mice by silencing ATXN3

BACKGROUND

Spinocerebellar ataxia type 3 (SCA3) is the most common autosomal dominant hereditary ataxia worldwide, which is however in a lack of effective treatment. In view of that engineered exosomes are a promising non-invasive gene therapy transporter that can overcome the traditional problem of poor drug delivery, the aim of this study was to evaluate, for the first time, the value of exosome-based microRNA therapy in SCA3 and the therapeutic effects of intravenously administrated ATXN3 targeting microRNAs in transgenic SCA3 mouse models.

METHODS

The rabies virus glycoprotein (RVG) peptide-modified exosomes loaded with miR-25 or miR-181a were peripherally injected to enable targeted delivery of miRNAs to the brain of SCA3 mice. The behaviors, ATXN3 level, purkinje cell and other neuronal loss, and neuroinflammation were evaluated 4 weeks after initial treatment.

RESULTS

The targeted and efficient delivery of miR-25 and miR-181a by modified exosomes substantially inhibited the mutant ATXN3 expression, reduced neuron apoptosis and induced motor improvements in SCA3 mouse models without increasing the neuroinflammatory response.

CONCLUSIONS

Our study confirmed the therapeutic potential of engineered exosome-based miR-25 and miR-181a treatment in substantially reducing ATXN3 aggregation and cytotoxicity by relying on its targeted and efficient drug delivery performance in SCA3 mice. This treatment method shows a promising prospect for future clinical applications in SCA3.

Are Therapies That Target α-Synuclein Effective at Halting Parkinson's Disease Progression? A Systematic Review

There are currently no pharmacological treatments available that completely halt or reverse the progression of Parkinson's Disease (PD). Hence, there is an unmet need for neuroprotective therapies. Lewy bodies are a neuropathological hallmark of PD and contain aggregated α-synuclein (α-syn) which is thought to be neurotoxic and therefore a suitable target for therapeutic interventions. To investigate this further, a systematic review was undertaken to evaluate whether anti-α-syn therapies are effective at preventing PD progression in preclinical in vivo models of PD and via current human clinical trials. An electronic literature search was performed using MEDLINE and EMBASE (Ovid), PubMed, the Web of Science Core Collection, and Cochrane databases to collate clinical evidence that investigated the targeting of α-syn. Novel preclinical anti-α-syn therapeutics provided a significant reduction of α-syn aggregations. Biochemical and immunohistochemical analysis of rodent brain tissue demonstrated that treatments reduced α-syn-associated pathology and rescued dopaminergic neuronal loss. Some of the clinical studies did not provide endpoints since they had not yet been completed or were terminated before completion. Completed clinical trials displayed significant tolerability and efficacy at reducing α-syn in patients with PD with minimal adverse effects. Collectively, this review highlights the capacity of anti-α-syn therapies to reduce the accumulation of α-syn in both preclinical and clinical trials. Hence, there is potential and optimism to target α-syn with further clinical trials to restrict dopaminergic neuronal loss and PD progression and/or provide prophylactic protection to avoid the onset of α-syn-induced PD.

Exosome and exosomal contents in schizophrenia

Schizophrenia (SCZ) is a severe mental disorder that affects approximately 1% general population worldwide and poses a considerable burden to society. Despite decades of research, its etiology remains unclear, and diagnosis remains challenging due to its heterogeneous symptoms. Exosomes play a crucial role in intercellular communication, and their contents, including nucleotides, proteins and metabolites, have been linked to various diseases. Recent studies have implicated exosome abnormalities in the pathogenesis of schizophrenia. In this review, we discuss the current understanding of the relationship between exosomes and schizophrenia, focusing on the role of exosomal contents in this disease. We summarize recent findings and provide insights into the potential use of exosomes as biomarkers for the diagnosis and treatment of schizophrenia.

Liquid Biopsy at the Frontier of Kidney Diseases: Application of Exosomes in Diagnostics and Therapeutics

In the era of precision medicine, liquid biopsy techniques, especially the use of urine analysis, represent a paradigm shift in the identification of biomarkers, with considerable implications for clinical practice in the field of nephrology. In kidney diseases, the use of this non-invasive tool to identify specific and sensitive biomarkers other than plasma creatinine and the glomerular filtration rate is becoming crucial for the diagnosis and assessment of a patient's condition. In recent years, studies have drawn attention to the importance of exosomes for diagnostic and therapeutic purposes in kidney diseases. Exosomes are nano-sized extracellular vesicles with a lipid bilayer structure, composed of a variety of biologically active substances. In the context of kidney diseases, studies have demonstrated that exosomes are valuable carriers of information and are delivery vectors, rendering them appealing candidates as biomarkers and drug delivery vehicles with beneficial therapeutic outcomes for kidney diseases. This review summarizes the applications of exosomes in kidney diseases, emphasizing the current biomarkers of renal diseases identified from urinary exosomes and the therapeutic applications of exosomes with reference to drug delivery and immunomodulation. Finally, we discuss the challenges encountered when using exosomes for therapeutic purposes and how these may affect its clinical applications.

Small extracellular vesicles: a novel drug delivery system for neurodegenerative disorders

Neurodegenerative diseases (NDs) have a slow onset and are usually detected late during disease. NDs are often difficult to cure due to the presence of the blood-brain barrier (BBB), which makes it difficult to find effective treatments and drugs, causing great stress and financial burden to families and society. Currently, small extracellular vesicles (sEVs) are the most promising drug delivery systems (DDSs) for targeted delivery of molecules to specific sites in the brain as a therapeutic vehicle due to their low toxicity, low immunogenicity, high stability, high delivery efficiency, high biocompatibility and trans-BBB functionality. Here, we review the therapeutic application of sEVs in several NDs, including Alzheimer's disease, Parkinson's disease, and Huntington's disease, discuss the current barriers associated with sEVs and brain-targeted DDS, and suggest future research directions.

Extracellular Vesicles as Drug Transporters

Extracellular vesicles (EVs) are lipid bilayer-delimited particles. According to their size and synthesis pathway, EVs can be classified into exosomes, ectosomes (microvesicles), and apoptotic bodies. Extracellular vesicles are of great interest to the scientific community due to their role in cell-to-cell communication and their drug-carrying abilities. The study aims to show opportunities for the application of EVs as drug transporters by considering techniques applicable for loading EVs, current limitations, and the uniqueness of this idea compared to other drug transporters. In addition, EVs have therapeutic potential in anticancer therapy (especially in glioblastoma, pancreatic cancer, and breast cancer).

Parkinson's Disease: From Genetics and Epigenetics to Treatment, a miRNA-Based Strategy

Parkinson's disease (PD) is one of the most common neurodegenerative disorders, characterized by an initial and progressive loss of dopaminergic neurons of the substantia nigra pars compacta via a potentially substantial contribution from protein aggregates, the Lewy bodies, mainly composed of α-Synuclein among other factors. Distinguishing symptoms of PD are bradykinesia, muscular rigidity, unstable posture and gait, hypokinetic movement disorder and resting tremor. Currently, there is no cure for PD, and palliative treatments, such as Levodopa administration, are directed to relieve the motor symptoms but induce severe side effects over time. Therefore, there is an urgency for discovering new drugs in order to design more effective therapeutic approaches. The evidence of epigenetic alterations, such as the dysregulation of different miRNAs that may stimulate many aspects of PD pathogenesis, opened a new scenario in the research for a successful treatment. Along this line, a promising strategy for PD treatment comes from the potential exploitation of modified exosomes, which can be loaded with bioactive molecules, such as therapeutic compounds and RNAs, and can allow their delivery to the appropriate location in the brain, overcoming the blood-brain barrier. In this regard, the transfer of miRNAs within Mesenchymal stem cell (MSC)-derived exosomes has yet to demonstrate successful results both in vitro and in vivo. This review, besides providing a systematic overview of both the genetic and epigenetic basis of the disease, aims to explore the exosomes/miRNAs network and its clinical potential for PD treatment.

Mmu-miR-25-3p promotes macrophage autophagy by targeting DUSP10 to reduce mycobacteria survival

Background

The present study aimed to investigate the regulation of miR-25-3p on macrophage autophagy and its effect on macrophage clearance of intracellular Mycobacterium bovis Bacillus Calmette-Guerin (BCG) retention based on the previous findings on the differential expression of exosomal miRNA in macrophages infected with BCG.

Methods

Through enrichment analysis and Hub gene analysis, key differentially expressed miRNA and its target genes were selected. The targeted binding ability of the screened mmu-miR-25-3p and its predicted target gene DUSP10 was determined through the TargetScan database, and this was further verified by dual luciferase reporter gene assay. mmu-miR-25-3p mimics, mmu-miR-25-3p inhibitor, si-DUSP10, miR-NC,si-NC and PD98059 (ERK Inhibitor) were used to intervene macrophages Raw264.7. Rt-qPCR was used to detect the expression levels of mmu-miR-25-3p and DUSP10 mRNA. Western blot was used to detect the expression levels of DUSP10, LC3-II, p-ERK1/2, beclin1, Atg5 and Atg7. The autophagy flux of macrophage Raw264.7 in each group was observed by confocal laser microscopy, and the expression distribution of DUSP10 and the structure of autophagosomes were observed by transmission electron microscopy. Finally, the intracellular BCG load of macrophage Raw264.7 was evaluated by colony-forming unit (CFU) assay.

Results

Bioinformatics analysis filtered and identified the differentially expressed exosomal miRNAs. As a result, mmu-miR-25-3p expression was significantly increased, and dual specificity phosphatase 10 (DUSP10) was predicted as its target gene that was predominantly involved in autophagy regulation. The dual luciferase reporter gene activity assay showed that mmu-miR-25-3p was targeted to the 3'-untranslated region (UTR) of DUSP10. The infection of BCG induced the upregulation of mmu-miR-25-3p and downregulation of DUSP10 in RAW264.7 cells, which further increased the expression of LC3-II and promoted autophagy. Upregulated mmu-miR-25-3p expression decreased the level of DUSP10 and enhanced the phosphorylation of ERK1/2, which in turn upregulated the expression of LC3-II, Atg5, Atg7, and Beclin1. Immuno-electron microscopy, transmission electron microscopy, and autophagic flux analysis further confirmed that the upregulation of mmu-miR-25-3p promotes the autophagy of macrophages after BCG infection. The CFU number indicated that upregulated mmu-miR-25-3p expression decreased the mycobacterial load and accelerated residual mycobacteria clearance.

Conclusion

mmu-miR-25-3p promotes the phosphorylation of ERK1/2 by inhibiting the expression of DUSP10, thus enhancing the BCG-induced autophagy of macrophages. These phenomena reduce the bacterial load of intracellular Mycobacterium and facilitate the clearance of residual mycobacteria. mmu-miR-25-3p has great potential as a target for anti-tuberculosis immunotherapy and can be the optimal miRNA loaded into exosomal drug delivery system in future studies.

Exosomes: Promising Delivery Tools for Overcoming Blood-Brain Barrier and Glioblastoma Therapy

Gliomas make up virtually 80% of all lethal primary brain tumors and are categorized based on their cell of origin. Glioblastoma is an astrocytic tumor that has an inferior prognosis despite the ongoing advances in treatment modalities. One of the main reasons for this shortcoming is the presence of the blood-brain barrier and blood-brain tumor barrier. Novel invasive and non-invasive drug delivery strategies for glioblastoma have been developed to overcome both the intact blood-brain barrier and leverage the disrupted nature of the blood-brain tumor barrier to target cancer cells after resection-the first treatment stage of glioblastoma. Exosomes are among non-invasive drug delivery methods and have emerged as a natural drug delivery vehicle with high biological barrier penetrability. There are various exosome isolation methods from different origins, and the intended use of the exosomes and starting materials defines the choice of isolation technique. In the present review, we have given an overview of the structure of the blood-brain barrier and its disruption in glioblastoma. This review provided a comprehensive insight into novel passive and active drug delivery techniques to overcome the blood-brain barrier, emphasizing exosomes as an excellent emerging drug, gene, and effective molecule delivery vehicle used in glioblastoma therapy.

Engineered extracellular vesicles for delivery of siRNA promoting targeted repair of traumatic spinal cord injury

Spinal cord injury (SCI) is a severe disease of the nervous system that causes irreparable damage and loss of function, for which no effective treatments are available to date. Engineered extracellular vesicles (EVs) carrying therapeutic molecules hold promise as an alternative SCI therapy depending on the specific functionalized EVs and the appropriate engineering strategy. In this study, we demonstrated the design of a drug delivery system of peptide CAQK-modified, siRNA-loaded EVs (C-EVs-siRNA) for SCI-targeted therapy. The peptide CAQK was anchored through a chemical modification to the membranes of EVs isolated from induced neural stem cells (iNSCs). CCL2-siRNA was then loaded into the EVs through electroporation. The modified EVs still maintained the basic properties of EVs and showed favorable targeting and therapeutic effects in vitro and in vivo. C-EVs-siRNA specifically delivered siRNA to the SCI region and was taken up by target cells. C-EVs-siRNA used the inherent anti-inflammatory and neuroreparative functions of iNSCs-derived EVs in synergy with the loaded siRNA, thus enhancing the therapeutic effect against SCI. The combination of targeted modified EVs and siRNA effectively regulated the microenvironmental disturbance after SCI, promoted the transformation of microglia/macrophages from M1 to M2 and limited the negative effects of the inflammatory response and neuronal injury on functional recovery in mice after SCI. Thus, engineered EVs are a potentially feasible and efficacious treatment for SCI, and may also be used to develop targeted treatments for other diseases.

Modification of Extracellular Vesicle Surfaces: An Approach for Targeted Drug Delivery

Extracellular vesicles (EVs) are a promising drug delivery vehicle candidate because of their natural origin and intrinsic function of transporting various molecules between different cells. Several advantages of the EV delivery platform include enhanced permeability and retention effect, efficient interaction with recipient cells, the ability to traverse biological barriers, high biocompatibility, high biodegradability, and low immunogenicity. Furthermore, EV membranes share approximately similar structures and contents to the cell membrane, which allows surface modification of EVs, an approach to enable specific targeting. Enhanced drug accumulation in intended sites and reduced adverse effects of chemotherapeutic drugs are the most prominent effects of targeted drug delivery. In order to improve the targeting ability of EVs, chemical modification and genetic engineering are the most adopted methods to date. Diverse chemical methods are employed to decorate EV surfaces with various ligands such as aptamers, carbohydrates, peptides, vitamins, and antibodies. In this review, we introduce the biogenesis, content, and cellular pathway of natural EVs and further discuss the genetic modification of EVs, and its challenges. Furthermore, we provide a comprehensive deliberation on the various chemical modification methods for improved drug delivery, which are directly related to increasing the therapeutic index.