Mesenchymal stem cell-derived exosome alleviates sepsis- associated acute liver injury by suppressing MALAT1 through microRNA-26a-5p: an innovative immunopharmacological intervention and therapeutic approach for sepsis

Liver injury in sepsis: manifestations, mechanisms and emerging therapeutic strategies

Sepsis is defined as a condition related to infection that manifests with multiorgan dysfunction, representing a life-threatening state. Consequently, severe complications frequently occur, with liver injury being one of the most prevalent serious complications of sepsis. Liver dysfunction during sepsis serves as an independent predictor of mortality. This review provides a comprehensive overview of current research on sepsis-induced liver injury (SILI), encompassing the clinical manifestations, diagnostic criteria, pathogenesis and therapeutic strategies associated with this condition. SILI may manifest as hypoxic hepatitis due to ischemia and shock, cholestasis resulting from abnormal bile metabolism, or bile duct sclerosis. The pathophysiology of sepsis involves intricate interactions among the inflammatory response, oxidative stress, and cell death. All of these factors complicate treatment and represent potential targets for therapeutic intervention. Furthermore, this review addresses the limitations inherent in conventional therapies currently employed for managing SILI and emphasizes the potential of novel targeted strategies aimed at addressing the fundamental mechanisms underlying this condition.

The Therapeutic Potential of Exosome Therapy in Sepsis Management: Addressing Complications and Improving Outcomes"

Infection occurs when pathogens penetrate tissues, reproduce, and trigger a host response to both the infectious agents and their toxins. A diverse array of pathogens, including viruses and bacteria, can cause infections. The host's immune system employs several mechanisms to combat these infections, typically involving an innate inflammatory response. Inflammation is a complex biological reaction that can affect various parts of the body and is a key component of the response to harmful stimuli. Sepsis arises when the body's response to infection leads to widespread damage to tissues and organs, potentially resulting in severe outcomes or death. The initial phase of sepsis involves immune system suppression. Early identification and targeted management are crucial for improving sepsis outcomes. Common treatment approaches include antibiotics, intravenous fluids, blood cultures, and monitoring urine output. This study explores the potential of exosome therapy in enhancing the management and alleviation of sepsis symptoms.

Pathogenic and therapeutic roles of extracellular vesicles in sepsis

Sepsis is a systemic injury resulting in vascular dysfunction, which can lead to multiple organ dysfunction, even shock and death. Extracellular vesicles (EVs) released by mammalian cells and bacteria have been shown to play important roles in intercellular communication and progression of various diseases. In past decades, the functional role of EVs in sepsis and its complications has been well explored. EVs are one of the paracrine components of cells. By delivering bioactive materials, EVs can promote immune responses, particularly the development of inflammation. In addition, EVs can serve as beneficial tools for delivering therapeutic cargos. In this review, we discuss the dual role of EVs in the progression and treatment of sepsis, exploring their intricate involvement in both inflammation and tissue repair processes. Specifically, the remarkable role of engineered strategies based on EVs in the treatment of sepsis is highlighted. The engineering EVs-mediated drug delivery and release strategies offer broad prospects for the effective treatment of sepsis. EVs-based approaches provide a novel avenue for diagnosing sepsis and offer opportunities for more precise intervention.

Noncoding RNAs in sepsis-associated acute liver injury: Roles, mechanisms, and therapeutic applications

Sepsis is a life-threatening syndrome characterized by organ dysfunction caused by a dysregulated host response to infection. Sepsis-associated acute liver injury (SA-ALI) is a frequent and serious complication of sepsis that considerably impacts both short-term and long-term survival outcomes. In intensive care units (ICUs), the mortality rate of patients with SA-ALI remains high, mostly due to the absence of effective early diagnostic markers and suitable therapeutic strategies. Recent studies have demonstrated the importance of non-coding RNAs (ncRNAs) in the development and progression of SA-ALI. This review focuses on the critical roles of ncRNAs, including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), in regulating "cytokine storms", oxidative stress, mitochondrial dysfunction, and programmed cell death in SA-ALI, and summarizes the current state and limitations of existing studies on lncRNAs and circRNAs in SA-ALI. By integrating advancements in high-throughput sequencing technologies, this review provides novel insights into the dual potential of ncRNAs as diagnostic biomarkers and therapeutic targets, offers new ideas for SA-ALI diagnosis and treatment research and highlights potential challenges in clinical translation.

Mesenchymal stem cell-derived exosomes improved septic lung injury by reducing excessive NETs formation and alleviating inflammatory response

To illustrate the potential of mesenchymal stem cell-derived exosomes (MSC-Exos) in mitigating septic lung injury by reducing the excessive formation of neutrophil extracellular traps (NETs), a mouse model of septic lung injury was induced through cecal ligation and puncture (CLP). The mice received intraperitoneal injections of MSC-Exos. Post injection, pathological alterations of the lung tissue were evaluated through HE staining, and the levels of inflammatory markers in each mouse group at various time points were assessed using ELISA kits. The presence of NETs markers in lung tissue (colocalization of CitH3 and MPO) was determined via immunofluorescence, and the levels of dsDNA in mouse serum were measured using a dsDNA kit. The findings indicated noticeable damage in the sepsis group postsurgically, whereas the severity of lung tissue damage was significantly diminished in mice of the MSC-Exos group. By the 72-h mark after the CLP procedure, there was an elevation in TNF-α, IL-6, IL-1β, and IL-10. Compared to the CLP group, the inflammatory factors in the serum of mice from the CLP + MSC-Exo group were higher at 12 and 24 h but decreased at the 72-h point. Furthermore, the fluorescence intensity of CitH3 and MPO and the dsDNA content increased in the CLP group mice over different time intervals, with MSC-Exos reversing these changes. In summary, MSC-Exos effectively suppressed sepsis-induced NETs formation and ameliorated lung injury.

Advances in the treatment of liver injury based on mesenchymal stem cell-derived exosomes

Mesenchymal stem cells (MSCs) have shown a great potential role in treating liver injury. MSCs can promote liver regeneration by differentiating into hepatocytes, and can also secrete exosomes to participate in the repair of liver injury. Increasing evidence has shown that mesenchymal stem cell-derived exosomes (MSC-EXOs) play an important role in treating liver injury. In this review, the biogenesis and function of exosomes and the characteristics of MSC-EXOs were analyzed based on recent research results. MSC-EXOs are significant in liver injuries such as liver fibrosis, liver failure, hepatocellular carcinoma, oxidative stress, and lipid steatosis, and participate in the process of liver regeneration.

Human liver stem cells and derived extracellular vesicles protect from sepsis-induced acute lung injury and restore bone marrow myelopoiesis in a murine model of sepsis

BACKGROUND

Sepsis is a condition with high mortality and morbidity, characterized by deregulation of the immune response against the pathogen. Current treatment strategies rely mainly on antibiotics and supportive care. However, there is growing interest in exploring cell-based therapies as complementary approaches. Human liver stem cells (HLSCs) are pluripotent cells of mesenchymal origin, showing some advantages compared to mesenchymal stem cells in terms of immunomodulatory properties. HSLC-derived extracellular vesicles (EVs) exhibited a superior efficacy profile compared to cells due to their potential to get through biological barriers and possibly to avoid tumorigenicity and showed to be effective in vivo and ex vivo models of liver and kidney disease. The potential of HLSCs and their EVs in recovering damage to distal organs due to sepsis other than the kidney remains unknown. This study aimed to investigate the therapeutic potential of the intravenous administration of HSLCs or HSLCs-derived EVs in a murine model of sepsis.

RESULTS

Sepsis was induced by caecal ligation and puncture (CLP) on C57/BL6 mice. After CLP, mice were assigned to receive either normal saline, HLSCs or their EVs and compared to a sham group which underwent only laparotomy. Survival, persistence of bacteraemia, lung function evaluation, histology and bone marrow analysis were performed. Administration of HLSCs or HLSC-EVs resulted in improved bacterial clearance and lung function in terms of lung elastance and oedema. Naïve murine hematopoietic progenitors in bone marrow were enhanced after treatment as well. Administration of HLSCs and HLSC-EVs after CLP to significantly improved survival.

CONCLUSIONS

Treatment with HLSCs or HLSC-derived EVs was effective in improving acute lung injury, dysmyelopoiesis and ultimately survival in this experimental murine model of lethal sepsis.

MRG15 aggravates sepsis-related liver injury by promoting PCSK9 synthesis and secretion

OBJECTIVE

Disorders of lipid oxidation play an important role in organ damage, and lipid metabolites are associated with inflammation and coagulation dysfunction in sepsis. However, the specific molecular mechanism by which lipid metabolism-related proteins regulate sepsis is still unclear. The aim of this study is to investigate the role of mortality factor 4-like protein 1 (MORF4L1, also called MRG15), a hepatic lipid metabolism related gene, in sepsis-induced liver injury.

METHODS

In the mouse sepsis models established by cecal ligation and puncture (CLP) and lipopolysaccharide (LPS), the impact of pretreatment with the MRG15 inhibitor argatroban on sepsis-related liver injury was investigated. In the LPS-induced hepatocyte sepsis cell model, the effects of MRG15 overexpression or knockdown on hepatic inflammation and lipid metabolism were studied. Additionally, in a co-culture system of hepatocytes and macrophages, the influence of MRG15 knockdown in hepatocytes on the synthesis and secretion of inflammation-related protein PCSK9 as well as its effect on macrophage activation were examined.

RESULTS

Studies have shown that MRG15 expression was increased in septicemia mice and positively correlated with lipid metabolism and inflammation. However, knockdown of MRG15 ameliorates sepsis-induced hepatocyte injury. Increased MRG15 in LPS-stimulated hepatocytes promotes PCSK9 synthesis and secretion, which induces macrophage M1 polarization and exacerbates the inflammatory response. Agatroban, an inhibitor of MRG15, ameliorates sepsis-induced liver injury in mice by inhibiting MRG15-induced lipid metabolism disorders and inflammatory responses.

CONCLUSIONS

In sepsis, increased MRG15 expression in hepatocytes leads to disturbed hepatic lipid metabolism and induces macrophage M1 polarization by secreting PCSK9, ultimately exacerbating liver injury.

Applications of plant-derived extracellular vesicles in medicine

Plant-derived extracellular vesicles (EVs) are promising therapeutic agents owing to their natural abundance, accessibility, and unique biological properties. This review provides a comprehensive exploration of the therapeutic potential of plant-derived EVs and emphasizes their anti-inflammatory, antimicrobial, and tumor-inhibitory effects. Here, we discussed the advancements in isolation and purification techniques, such as ultracentrifugation and size-exclusion chromatography, which are critical for maintaining the functional integrity of these nanovesicles. Next, we investigated the diverse administration routes of EVs and carefully weighed their respective advantages and challenges related to bioavailability and patient compliance. Moreover, we elucidated the multifaceted mechanisms of action of plant-derived EVs, including their roles in anti-inflammation, antioxidation, antitumor activity, and modulation of gut microbiota. We also discussed the impact of EVs on specific diseases such as cancer and inflammatory bowel disease, highlighting the importance of addressing current challenges related to production scalability, regulatory compliance, and immunogenicity. Finally, we proposed future research directions for optimizing EV extraction and developing targeted delivery systems. Through these efforts, we envision the seamless integration of plant-derived EVs into mainstream medicine, offering safe and potent therapeutic alternatives across various medical disciplines.

The Effects of Mesenchymal Stem Cells-Derived Exosomes on Metabolic Reprogramming in Scar Formation and Wound Healing

Pathological scarring results from aberrant cutaneous wound healing due to the overactivation of biological behaviors of human skin fibroblasts, characterized by local inordinate inflammation, excessive extracellular matrix and collagen deposition. Yet, its underlying pathogenesis opinions vary, which could be caused by increased local mechanical tension, enhanced and continuous inflammation, gene mutation, as well as cellular metabolic disorder, etc. Metabolic reprogramming is the process by which the metabolic pattern of cells undergoes a systematic adjustment and transformation to adapt to the changes of the external environment and meet the needs of their growth and differentiation. Therefore, the abnormality of metabolic reprogramming in cells within wounds and scars attaches great importance to scar formation. Mesenchymal stem cells-derived exosomes (MSC-Exo) are the extracellular vesicles that play an important role in tissue repair, cancer treatment as well as immune and metabolic regulation. However, there is not a systematic work to detail the relevant studies. Herein, we gave a comprehensive summary of the existing research on three main metabolisms, including glycometabolism, lipid metabolism and amino acid metabolism, and MSC-Exo regulating metabolic reprogramming in wound healing and scar formation for further research reference.

Therapeutic Effects of Mesenchymal Stem Cell-Derived Extracellular Vesicles in sepsis: a Systematic Review and Meta-Analysis of Preclinical Studies

BACKGROUND

Sepsis is a life-threatening disorder with no definitive cure. Preclinical studies suggest that extracellular vesicles derived from mesenchymal stromal cells (EV-MSCs) can mitigate inflammatory conditions, potentially leading to increased survival and reduced organ dysfunction during sepsis. Our aim to conduct this systematic review and meta-analysis is assessing the EV-MSCs therapeutic efficacy in sepsis.

METHODS

PubMed, Embase, Scopus, WOS and ProQuest databases and also Google Scholar search engine were searched for published articles. We used hazard ratio (HR) and standardized mean difference (SMD) as effect sizes to evaluate the therapeutic effect of EV-MSCs on survival rate and determine their effect on reducing organ dysfunction, respectively. Finally, we employed GRADE tool for preclinical animal studies to evaluate certainty of the evidence.

RESULTS

30 studies met the inclusion criteria for our article. Our meta-analysis results demonstrate that animals treated with MSC-EVs have better survival rate than untreated animals (HR = 0.33; 95% CI: 0.27-0.41). Our meta-analysis suggests that EV-MSCs can reduce organ dysfunctions in sepsis, such as the lung, kidney, and liver. Additionally, EV-MSCs decrease pro-inflammatory mediators like TNF-α, IL-1β, and IL-6.

CONCLUSION

Our results indicate that EV-MSCs can be as promising therapy for sepsis management in animal models and leading to increased survival rate and reduced organ dysfunction. Furthermore, our study introduces a novel tool for risk of bias assessment and provides recommendations based on various analysis. Future studies with aiming to guide clinical translation can utilize the results of this article to establish stronger evidence for EV-MSC effectiveness.

Exosome-Derived microRNA: Potential Target for Diagnosis and Treatment of Sepsis

Exosome-derived microRNAs (miRNAs) are emerging as pivotal players in the pathophysiology of sepsis, representing a new frontier in both the diagnosis and treatment of this complex condition. Sepsis, a severe systemic response to infection, involves intricate immune and nonimmune mechanisms, where exosome-mediated communication can significantly influence disease progression and outcomes. During the progress of sepsis, the miRNA profile of exosomes undergoes notable alterations, is reflecting, and may affect the progression of the disease. This review comprehensively explores the biology of exosome-derived miRNAs, which originate from both immune cells (such as macrophages and dendritic cells) and nonimmune cells (such as endothelial and epithelial cells) and play a dynamic role in modulating pathways that affect the course of sepsis, including those related to inflammation, immune response, cell survival, and apoptosis. Taking into account these dynamic changes, we further discuss the potential of exosome-derived miRNAs as biomarkers for the early detection and prognosis of sepsis and advantages over traditional biomarkers due to their stability and specificity. Furthermore, this review evaluates exosome-based therapeutic miRNA delivery systems in sepsis, which may pave the way for targeted modulation of the septic response and personalized treatment options.

Combinational therapy of mesenchymal stem cell-derived extracellular vesicles and azithromycin improves clinical and histopathological recovery in CLP sepsis model

BACKGROUND

Sepsis is a syndrome that occurs following an infection and marked by severe inflammatory responses, and if not treated in time, it can lead to multi-organ failure syndrome and death. This study examines the effects of a novel combination therapy using azithromycin and mesenchymal stem cell-derived extracellular vesicles (EVs) on a cecal ligation and puncture (CLP) model of sepsis.

METHODS

Human Wharton's jelly-mesenchymal stem cells were cultured, characterized, and used to extract EVs. The CLP sepsis model was induced in mice, followed by treatments: saline, AZM, EVs, and combination therapy (A+E). Clinical sepsis scores were recorded 24 h post-treatment. Serum, peritoneal fluid, and organ tissues (kidney, liver, lung) were collected and analyzed for biochemical parameters (AST ALT, and creatinine), inflammatory markers, bacterial load, and histopathological changes.

RESULTS

The A+E combined treatment improved the clinical scores of septic mice. The administration of A+E reduced bacterial loads in the peritoneum of septic mice, contributing to effective control of infection. Inflammatory markers of neutrophils-to-lymphocytes ratio (NLR) and TNF-α serum levels were significantly lower in the combinational therapy group, indicating significant anti-inflammatory effect of this combination. Additionally, combination of AZM and EVs alleviated organ damage mainly within liver, kidneys and lungs. Based on histopathological assessments and biochemical parameters, there was diminished tissue damage as well as reduced inflammation, which is correlated with improved functions of these vital organs.

CONCLUSION

The combined use of azithromycin and EVs offers a promising therapeutic approach for sepsis by effectively controlling infection and modulating the inflammatory response.

MSC-derived small extracellular vesicles mitigate diabetic retinopathy by stabilizing Nrf2 through miR-143-3p-mediated inhibition of neddylation

Diabetic retinopathy (DR) is a highly hazardous and widespread complication of diabetes mellitus (DM). The accumulated reactive oxygen species (ROS) play a central role in DR development. The aim of this research was to examine the impact and mechanisms of mesenchymal stem cell (MSC)-derived small extracellular vesicles (sEV) on regulating ROS and retinal damage in DR. Intravitreal injection of sEV inhibited Cullin3 neddylation, stabilized Nrf2, decreased ROS, reduced retinal inflammation, suppressed Müller gliosis, and mitigated DR. Based on MSC-sEV miRNA sequencing, bioinformatics software, and dual-luciferase reporter assay, miR-143-3p was identified to be the key effector for MSC-sEV's role in regulating neural precursor cell expressed developmentally down-regulated 8 (NEDD8)-mediated neddylation. sEV were able to be internalized by Müller cells. Compared to advanced glycation end-products (AGEs)-induced Müller cells, sEV coculture decreased Cullin3 neddylation, activated Nrf2 signal pathway to combat ROS-induced inflammation. The barrier function of endothelial cells was impaired when endothelial cells were treated with the supernatant of AGEs-induced Müller cells, but was restored when treated with supernatant of AGEs-induced Müller cells cocultured with sEV. The protective effect of sEV was, however, compromised when miR-143-3p was inhibited in sEV. Moreover, the protective efficacy of sEV was diminished when NEDD8 was overexpressed in Müller cells. These findings showed MSC-sEV delivered miR-143-3p to inhibit Cullin3 neddylation, stabilizing Nrf2 to counteract ROS-induced inflammation and reducing vascular leakage. Our findings suggest that MSC-sEV may be a potential nanotherapeutic agent for DR, and that Cullin3 neddylation could be a new target for DR therapy.

RNF31 alleviates liver steatosis by promoting p53/BNIP3-related mitophagy in hepatocytes

BACKGROUND & AIMS

Non-alcoholic fatty liver disease (NAFLD) is one of the liver illnesses that may be affected by mitophagy, which is the selective removal of damaged mitochondria. RNF31, an E3 ubiquitin ligase, is carcinogenic in many malignancies. However, the influence of RNF31 on mitochondrial homeostasis and NAFLD development remains unknown.

METHODS

Oleic-palmitic acid treated hepatocytes and high-fat diet (HFD)-fed mice were established to observe the effect of RNF31 on hepatocyte mitophagy and steatosis. Mitophagy processes were comprehensively assessed by mt-Keima fluorescence imaging, while global changes in hepatic gene expression were measured by RNA-seq.

RESULTS

The present study discovered a reduction in RNF31 expression in lipotoxic hepatocytes with mitochondrial dysfunction. The observed decrease in RNF31 expression was associated with reduced mitochondrial membrane potential, disturbed mitophagy, and increased steatosis. Additionally, the findings indicated that RNF31 is a pivotal factor in the initiation of mitophagy and the facilitation of mitochondrial homeostasis, resulting in a decrease in steatosis in lipotoxic hepatocytes. Mechanistically, RNF31 enhanced p53 ubiquitination and subsequent proteasomal degradation. Down-regulation of p53 led to increased expression of the mitophagy receptor protein BCL2 and adenovirus E1B 19 kDa-interacting protein 3 (BNIP3), thereby promoting mitophagy in hepatocytes. Furthermore, it was demonstrated that the transportation of RNF31 via small extracellular vesicles derived from mesenchymal stem cells (referred to as sEV) had a substantial influence on reducing hepatic steatosis and restoring liver function in HFD-fed mice.

CONCLUSIONS

The findings highlight RNF31's essential role in the regulation of mitochondrial homeostasis in hepatocytes, emphasizing its potential as a therapeutic target for NAFLD.

Therapeutic Effects of Engineered Exosomes from RAW264.7 Cells Overexpressing hsa-let-7i-5p against Sepsis in Mice-A Comparative Study with Human Placenta-Derived Mesenchymal Stem Cell Exosomes

This study compared the therapeutic effects of engineered exosomes derived from RAW264.7 cells overexpressing hsa-let-7i-5p (engineered exosomes) to exosomes from human placenta-derived mesenchymal stem cells (hpMSC exosomes) against sepsis-induced acute lung injury. Adult male C57BL/6 mice were divided into lipopolysaccharide (LPS), LPS plus engineered exosome (LEExo), or LPS plus hpMSC exosome (LMExo) groups, alongside control groups. The results showed that lung injury scores (based on pathohistological characteristics) and the levels of lung function alterations, tissue edema, and leukocyte infiltration in LEExo and LMExo groups were comparable and significantly lower than in the LPS group (all p < 0.05). Furthermore, the levels of inflammation (nuclear factor-κB activation, cytokine upregulation), macrophage activation (hypoxia-inducible factor-1α activation, M1 phase polarization), oxidation, and apoptosis were diminished in LEExo and LMExo groups compared to the LPS group (all p < 0.05). Inhibition of hsa-let-7i-5p attenuated the therapeutic effects of both engineered and hpMSC exosomes. These findings underscore the potent therapeutic capacity of engineered exosomes enriched with hsa-let-7i-5p and their potential as an alternative to hpMSC exosomes for sepsis treatment. Continued research into the mechanisms of action and optimization of engineered exosomes could pave the way for their future clinical application.

MSC-derived exosomal miR-140-3p improves cognitive dysfunction in sepsis-associated encephalopathy by HMGB1 and S-lactoylglutathione metabolism

MiRNAs in mesenchymal stem cells (MSCs)-derived exosome (MSCs-exo) play an important role in the treatment of sepsis. We explored the mechanism through which MSCs-exo influences cognitive impairment in sepsis-associated encephalopathy (SAE). Here, we show that miR-140-3p targeted Hmgb1. MSCs-exo plus miR-140-3p mimic (Exo) and antibiotic imipenem/cilastatin (ABX) improve survival, weight, and cognitive impairment in cecal ligation and puncture (CLP) mice. Exo and ABX inhibit high mobility group box 1 (HMGB1), IBA-1, interleukin (IL)-1β, IL-6, iNOS, TNF-α, p65/p-p65, NLRP3, Caspase 1, and GSDMD-N levels. In addition, Exo upregulates S-lactoylglutathione levels in the hippocampus of CLP mice. Our data further demonstrates that Exo and S-lactoylglutathione increase GSH levels in LPS-induced HMC3 cells and decrease LD and GLO2 levels, inhibiting inflammatory responses and pyroptosis. These findings suggest that MSCs-exo-mediated delivery of miR-140-3p ameliorates cognitive impairment in mice with SAE by HMGB1 and S-lactoylglutathione metabolism, providing potential therapeutic targets for the clinical treatment of SAE.

Advances in Mesenchymal stem cells regulating macrophage polarization and treatment of sepsis-induced liver injury

Sepsis is a syndrome of dysregulated host response caused by infection, which leads to life-threatening organ dysfunction. It is a familiar reason of death in critically ill patients. Liver injury frequently occurs in septic patients, yet the development of targeted and effective treatment strategies remains a pressing challenge. Macrophages are essential parts of immunity system. M1 macrophages drive inflammation, whereas M2 macrophages possess anti-inflammatory properties and contribute to tissue repair processes. Mesenchymal stem cells (MSCs), known for their remarkable attributes including homing capabilities, immunomodulation, anti-inflammatory effects, and tissue regeneration potential, hold promise in enhancing the prognosis of sepsis-induced liver injury by harmonizing the delicate balance of M1/M2 macrophage polarization. This review discusses the mechanisms by which MSCs regulate macrophage polarization, alongside the signaling pathways involved, providing an idea for innovative directions in the treatment of sepsis-induced liver injury.

Engineered Extracellular Vesicles: Emerging Therapeutic Strategies for Translational Applications

Extracellular vesicles (EVs) are small, membrane-bound vesicles used by cells to deliver biological cargo such as proteins, mRNA, and other biomolecules from one cell to another, thus inducing a specific response in the target cell and are a powerful method of cell to cell and organ to organ communication, especially during the pathogenesis of human disease. Thus, EVs may be utilized as prognostic and diagnostic biomarkers, but they also hold therapeutic potential just as mesenchymal stem cells have been used in therapeutics. However, unmodified EVs exhibit poor targeting efficacy, leading to the necessity of engineered EVS. To highlight the advantages and therapeutic promises of engineered EVs, in this review, we summarized the research progress on engineered EVs in the past ten years, especially in the past five years, and highlighted their potential applications in therapeutic development for human diseases. Compared to the existing stem cell-derived EV-based therapeutic strategies, engineered EVs show greater promise in clinical applications: First, engineered EVs mediate good targeting efficacy by exhibiting a targeting peptide that allows them to specifically target a specific organ or even cell type, thus avoiding accumulation in undesired locations and increasing the potency of the treatment. Second, engineered EVs can be artificially pre-loaded with any necessary biomolecular cargo or even therapeutic drugs to treat a variety of human diseases such as cancers, neurological diseases, and cardiovascular ailments. Further research is necessary to improve logistical challenges in large-scale engineered EV manufacturing, but current developments in engineered EVs prove promising to greatly improve therapeutic treatment for traditionally difficult to treat diseases.

Exosomes: Potential Next-Generation Nanocarriers for the Therapy of Inflammatory Diseases

Inflammatory diseases are common pathological processes caused by various acute and chronic factors, and some of them are autoimmune diseases. Exosomes are fundamental extracellular vesicles secreted by almost all cells, which contain a series of constituents, i.e., cytoskeletal and cytosolic proteins (actin, tubulin, and histones), nucleic acids (mRNA, miRNA, and DNA), lipids (diacylglycerophosphates, cholesterol, sphingomyelin, and ceramide), and other bioactive components (cytokines, signal transduction proteins, enzymes, antigen presentation and membrane transport/fusion molecules, and adhesion molecules). This review will be a synopsis of the knowledge on the contribution of exosomes from different cell sources as possible therapeutic agents against inflammation, focusing on several inflammatory diseases, neurological diseases, rheumatoid arthritis and osteoarthritis, intestinal bowel disease, asthma, and liver and kidney injuries. Current knowledge indicates that the role of exosomes in the therapy of inflammation and in inflammatory diseases could be distinctive. The main limitations to their clinical translation are still production, isolation, and storage. Additionally, there is an urgent need to personalize the treatments in terms of the selection of exosomes; their dosages and routes of administration; and a deeper knowledge about their biodistribution, type and incidence of adverse events, and long-term effects of exosomes. In conclusion, exosomes can be a very promising next-generation therapeutic option, superior to synthetic nanocarriers and cell therapy, and can represent a new strategy of effective, safe, versatile, and selective delivery systems in the future.