Crosstalk between Oxidative Stress and Exosomes

Viral Infections and the Glutathione Peroxidase Family: Mechanisms of Disease Development

Significance: The glutathione peroxidase (GPx) family is recognized for its essential function in maintaining cellular redox balance and countering the overproduction of reactive oxygen species (ROS), a process intricately linked to the progression of various diseases including those spurred by viral infections. The modulation of GPx activity by viruses presents a critical juncture in disease pathogenesis, influencing cellular responses and the trajectory of infection-induced diseases. Recent Advances: Cutting-edge research has unveiled the GPx family's dynamic role in modulating viral pathogenesis. Notably, GPX4's pivotal function in regulating ferroptosis presents a novel avenue for the antiviral therapy. The discovery that selenium, an essential micronutrient for GPx activity, possesses antiviral properties has propelled us toward rethinking traditional treatment modalities. Critical Issues: Deciphering the intricate relationship between viral infections and GPx family members is paramount. Viral invasion can precipitate significant alterations in GPx function, influencing disease outcomes. The multifaceted nature of GPx activity during viral infections suggests that a deeper understanding of these interactions could yield novel insights into disease mechanisms, diagnostics, prognostics, and even chemotherapeutic resistance. Future Directions: This review aims to synthesize current knowledge on the impact of viral infections on GPx activity and expression and identify key advances. By elucidating the mechanisms through which GPx family members intersect with viral pathogenesis, we propose to uncover innovative therapeutic strategies that leverage the antioxidant properties of GPx to combat viral infections. The exploration of GPx as a therapeutic target and biomarker holds promise for the development of next-generation antiviral therapies. Antioxid. Redox Signal. 00, 000-000.

Fundamentals of redox regulation in biology

Oxidation-reduction (redox) reactions are central to the existence of life. Reactive species of oxygen, nitrogen and sulfur mediate redox control of a wide range of essential cellular processes. Yet, excessive levels of oxidants are associated with ageing and many diseases, including cardiological and neurodegenerative diseases, and cancer. Hence, maintaining the fine-tuned steady-state balance of reactive species production and removal is essential. Here, we discuss new insights into the dynamic maintenance of redox homeostasis (that is, redox homeodynamics) and the principles underlying biological redox organization, termed the 'redox code'. We survey how redox changes result in stress responses by hormesis mechanisms, and how the lifelong cumulative exposure to environmental agents, termed the 'exposome', is communicated to cells through redox signals. Better understanding of the molecular and cellular basis of redox biology will guide novel redox medicine approaches aimed at preventing and treating diseases associated with disturbed redox regulation.

Isolation and Characterization of Extracellular Vesicles of Chick Embryo Blood

Exosomes from plants or animals are a cheap, available, and promising option in medicine, which can be used for the detection or treatment of various diseases. This study aims to evaluate the antitoxic and antioxidant properties of Extracellular vesicle (EVs) extracted from chicken embryo blood using a fibroblast cell line (NIH/3T3). EVs from chick embryos were extracted in this experimental investigation using the sedimentation method and examined using dynamic light scattering (DLS) and field emission electron microscopy (FE-SEM). The protein concentration and overall antioxidant capacity of the EVs were determined using bicinchoninic acid (BCA) and antioxidant capacity (FRAP). EVs were added to NIH/3T3 cells at varying concentrations (1, 2, and 10 mg/ml), and the MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay test was used to measure cell survival. The size of the isolated EVs was confirmed to be less than 100 nm by electron microscopy and DLS. The quantity of protein in these EVs was 3200 µg/ml, and their total antioxidant capacities were 3130.17, 1914.122, and 976.9 μMol/L. The MTT test findings demonstrated that NIH/3T3 cells survived treatment with EVs (P ≤ 0.001) compared to the control group. Antioxidant-rich and protein-rich exosomes in chicken embryos may be valuable in managing oxidative stress.

Global Research Trends on Exosome in Cardiovascular Diseases: A Bibliometric-Based Visual Analysis

Background

Exosomes in cardiovascular diseases (CVDs) have attracted huge attention with substantial value and potential. Our bibliometrics is based on literature from the field of cardiovascular exosomes over the past 30 years, which has been visualized to display the development process, research hotspots, and cutting-edge trends of clinical practices, mechanisms, and management strategies related to psych cardiology.

Methods

We selected articles and reviews on exosomes in CVDs from the core collection of Web of Science, and generated visual charts by using CiteSpace and VOSviewer software.

Results

Our research included 1613 publications. The number of exosome articles in CVD fluctuates slightly, but overall shows an increasing trend. The main research institutions were Tongji University and Nanjing Medical University. The International Journal of Molecular Sciences has the highest publication volume, while the Journal of Cellular and Molecular Medicine has the highest citation count. Among all the authors, Eduardo Marban ranks first in terms of publication volume and H-index. The most common keywords are exosome, extracellular vesicles, and angiogenesis.

Conclusion

This is a bibliometric study on the research hotspots and trends of exosomes in CVD. Exosome research in the field of cardiovascular medicine is on the rise. Some exosome treatment methods may become the focus of future research.

Decoding Organelle Interactions: Unveiling Molecular Mechanisms and Disease Therapies

Organelles, substructures in the cytoplasm with specific morphological structures and functions, interact with each other via membrane fusion, membrane transport, and protein interactions, collectively termed organelle interaction. Organelle interaction is a complex biological process involving the interaction and regulation of several organelles, including the interaction between mitochondria-endoplasmic reticulum, endoplasmic reticulum-Golgi, mitochondria-lysosomes, and endoplasmic reticulum-peroxisomes. This interaction enables intracellular substance transport, metabolism, and signal transmission, and is closely related to the occurrence, development, and treatment of many diseases, such as cancer, neurodegenerative diseases, and metabolic diseases. Herein, the mechanisms and regulation of organelle interactions are reviewed, which are critical for understanding basic principles of cell biology and disease development mechanisms. The findings will help to facilitate the development of novel strategies for disease prevention, diagnosis, and treatment opportunities.

Secretome profiling reveals acute changes in oxidative stress, brain homeostasis, and coagulation following short-duration spaceflight

As spaceflight becomes more common with commercial crews, blood-based measures of crew health can guide both astronaut biomedicine and countermeasures. By profiling plasma proteins, metabolites, and extracellular vesicles/particles (EVPs) from the SpaceX Inspiration4 crew, we generated "spaceflight secretome profiles," which showed significant differences in coagulation, oxidative stress, and brain-enriched proteins. While >93% of differentially abundant proteins (DAPs) in vesicles and metabolites recovered within six months, the majority (73%) of plasma DAPs were still perturbed post-flight. Moreover, these proteomic alterations correlated better with peripheral blood mononuclear cells than whole blood, suggesting that immune cells contribute more DAPs than erythrocytes. Finally, to discern possible mechanisms leading to brain-enriched protein detection and blood-brain barrier (BBB) disruption, we examined protein changes in dissected brains of spaceflight mice, which showed increases in PECAM-1, a marker of BBB integrity. These data highlight how even short-duration spaceflight can disrupt human and murine physiology and identify spaceflight biomarkers that can guide countermeasure development.

Extracellular Vesicles Derived from H2O2-Stimulated Adipose-Derived Stem Cells Alleviate Senescence in Diabetic Bone Marrow Mesenchymal Stem Cells and Restore Their Osteogenic Capacity

Introduction

Autologous stem cell transplantation has emerged as a promising strategy for bone repair. However, the osteogenic potential of mesenchymal stem cells derived from diabetic patients is compromised, possibly due to hyperglycemia-induced senescence. The objective of this study was to assess the preconditioning effects of extracellular vesicles derived from H2O2-stimulated adipose-derived stem cells (ADSCs) and non-modified ADSCs on the osteogenic potential of diabetic bone marrow mesenchymal stem cells (BMSCs).

Methods

Sprague-Dawley (SD) rats were experimentally induced into a diabetic state through a high-fat diet followed by an injection of streptozotocin, and diabetic BMSCs were collected from the bone marrow of these rats. Extracellular vesicles (EVs) were isolated from the conditioned media of ADSCs, with or without hydrogen peroxide (H2O2) preconditioning, using density gradient centrifugation. The effects of H2O2 preconditioning on the morphology, marker expression, and particle size of the EVs were analyzed. Furthermore, the impact of EV-pretreatment on the viability, survivability, migration ability, osteogenesis, cellular senescence, and oxidative stress of diabetic BMSCs was examined. Moreover, the expression of the Nrf2/HO-1 pathway was also assessed to explore the underlying mechanism. Additionally, we transplanted EV-pretreated BMSCs into calvarial defects in diabetic rats to assess their in vivo bone formation and anti-senescence capabilities.

Results

Our study demonstrated that pretreatment with EVs from ADSCs significantly improved the viability, senescence, and osteogenic differentiation potential of diabetic BMSCs. Moreover, in-vitro experiments revealed that diabetic BMSCs treated with H2O2-activated EVs exhibited increased viability, reduced senescence, and enhanced osteogenic differentiation compared to those treated with non-modified EVs. Furthermore, when transplanted into rat bone defects, diabetic BMSCs treated with H2O2-activated EVs showed improved bone regeneration potential and enhanced anti-senescence function t compared to those treated with non-modified EVs. Both H2O2-activated EVs and non-modified EVs upregulated the expression of the Nrf2/HO-1 pathway in diabetic BMSCs, however, the promoting effect of H2O2-activated EVs was more pronounced than that of non-modified EVs.

Conclusion

Extracellular vesicles derived from H2O2-preconditioned ADSCs mitigated senescence in diabetic BMSCs and enhanced their bone regenerative functions via the activation of the Nrf2/HO-1 pathway.

A comprehensive insight into the immunomodulatory role of MSCs-derived exosomes (MSC-Exos) through modulating pattern-recognition receptors (PRRs)

Mesenchymal stem cell-derived exosomes (MSC-Exos) are emerging as remarkable agents in the field of immunomodulation with vast potential for diagnosing and treating various diseases, including cancer and autoimmune disorders. These tiny vesicles are laden with a diverse cargo encompassing proteins, nucleic acids, lipids, and bioactive molecules, offering a wealth of biomarkers and therapeutic options. MSC-Exos exhibit their immunomodulatory prowess by skillfully regulating pattern-recognition receptors (PRRs). They conduct a symphony of immunological responses, modulating B-cell activities, polarizing macrophages toward anti-inflammatory phenotypes, and fine-tuning T-cell activity. These interactions have profound implications for precision medicine, cancer immunotherapy, autoimmune disease management, biomarker discovery, and regulatory approvals. MSC-Exos promises to usher in a new era of tailored therapies, personalized diagnostics, and more effective treatments for various medical conditions. As research advances, their transformative potential in healthcare becomes increasingly evident.

Vitamin E Attenuates Red-Light-Mediated Vasodilation: The Benefits of a Mild Oxidative Stress

Red light (670 nm) energy controls vasodilation via the formation of a transferable endothelium-derived nitric oxide (NO)-precursor-containing substance, its intracellular traffic, and exocytosis. Here we investigated the underlying mechanistic effect of oxidative stress on light-mediated vasodilation by using pressure myography on dissected murine arteries and immunofluorescence on endothelial cells. Treatment with antioxidants Trolox and catalase decreased vessel dilation. In the presence of catalase, a lower number of exosomes were detected in the vessel bath. Light exposure resulted in increased cellular free radical levels. Mitochondrial reactive oxygen species were also more abundant but did not alter cellular ATP production. Red light enhanced the co-localization of late exosome marker CD63 and cellular S-nitrosoprotein to a greater extent than high glucose, suggesting that a mild oxidative stress favors the localization of NO precursor in late exosomes. Exocytosis regulating protein Rab11 was more abundant after irradiation. Our findings conclude that red-light-induced gentle oxidative stress facilitates the dilation of blood vessels, most likely through empowering the traffic of vasodilatory substances. Application of antioxidants disfavors this mechanism.

NOX2 and NOX4 expression in monocytes and macrophages-extracellular vesicles in signalling and therapeutics

Extracellular vesicles (EVs) are a type of cytoplasmic vesicles secreted by a variety of cells. EVs originating from cells have been known to participate in cell communication, antigen presentation, immune cell activation, tolerance induction, etc. These EVs can also carry the active form of Nicotinamide Adenine Dinucleotide Phosphate Oxidase Hydrogen (NADPH) oxidase, which is very essential for the production of reactive oxygen species (ROS) and that can then modulate processes such as cell regeneration. The aim of this study is to characterize the EVs isolated from U-937 and THP-1 cells, identify the NADPH oxidase (NOX) isoforms, and to determine whether EVs can modulate NOX4 and NOX2 in monocytes and macrophages. In our study, isolated EVs of U-937 were characterized using dynamic light scattering (DLS) spectroscopy and immunoblotting. The results showed that the exogenous addition of differentiation agents (either phorbol 12-myristate 13-acetate (PMA) or ascorbic acid) or the supplementation of EVs used in the study did not cause any stress leading to alterations in cell proliferation and viability. In cells co-cultured with EVs for 72 h, strong suppression of NOX4 and NOX2 is evident when monocytes transform into macrophagic cells. We also observed lower levels of oxidative stress measured using immunoblotting and electron paramagnetic resonance spectroscopy under the EVs co-cultured condition, which also indicates that EVs might contribute significantly by acting as an antioxidant source, which agrees with previous studies that hypothesized the role of EVs in therapeutics. Therefore, our results provide evidence for NOX regulation by EVs in addition to its role as an antioxidant cargo.

Periodontal ligament stem cell-derived exosome-loaded Emodin mediated antimicrobial photodynamic therapy against cariogenic bacteria

BACKGROUND

This study was conducted to investigate the efficiency of periodontal ligament (PDL) stem cell-derived exosome-loaded Emodin (Emo@PDL-Exo) in antimicrobial photodynamic therapy (aPDT) on Streptococcus mutans and Lactobacillus acidophilus as the cariogenic bacteria.

MATERIALS AND METHODS

After isolating and characterizing PDL-Exo, the study proceeded to prepare and verify the presence of Emo@PDL-Exo. The antimicrobial effect, anti-biofilm activity, and anti-metabolic potency of Emo, PDL-Exo, and Emo@PDL-Exo were then evaluated with and without irradiation of blue laser at a wavelength of 405 ± 10 nm with an output intensity of 150 mW/cm2 for a duration of 60 s. In addition, the study assessed the binding affinity of Emodin with GtfB and SlpA proteins using in silico molecular docking. Eventually, the study examined the generation of endogenous reactive oxygen species (ROS) and changes in the gene expression levels of gelE and sprE.

RESULTS

The study found that using Emo@PDL-Exo-mediated aPDT resulted in a significant decrease in L. acidophilus and S. mutans by 4.90 ± 0.36 and 5.07 log10 CFU/mL, respectively (P < 0.05). The study found that using Emo@PDL-Exo for aPDT significantly reduced L. acidophilus and S. mutans biofilms by 44.7% and 50.4%, respectively, compared to untreated biofilms in the control group (P < 0.05). Additionally, the metabolic activity of L. acidophilus and S. mutans decreased by 58.3% and 71.2%, respectively (P < 0.05). The molecular docking analysis showed strong binding affinities of Emodin with SlpA and GtfB proteins, with docking scores of -7.4 and -8.2 kcal/mol, respectively. The study also found that the aPDT using Emo@PDL-Exo group resulted in the most significant reduction in gene expression of slpA and gtfB, with a decrease of 4.2- and 5.6-folds, respectively, compared to the control group (P < 0.05), likely due to the increased generation of endogenous ROS.

DISCUSSION

The study showed that aPDT using Emo@PDL-Exo can effectively reduce the cell viability, biofilm activity, and metabolic potency of S. mutans and L. acidophilus. aPDT also significantly reduced the expression levels of gtfB and slpA mRNA due to the increased endogenous ROS generation. The findings suggest that Emo@PDL-Exo-mediated aPDT could be a promising antimicrobial approach against cariogenic microorganisms.

Exosome Mediated Cell-Cell Crosstalk in Tissue Injury and Repair

The landscape of exosome research has undergone a significant paradigm shift, with a departure from early conceptions of exosomes as vehicles for cellular waste disposal towards their recognition as integral components of cellular communication with therapeutic potential. This chapter presents an exhaustive elucidation of exosome biology, detailing the processes of exosome biogenesis, release, and uptake, and their pivotal roles in signal transduction, tissue repair, regeneration, and intercellular communication. Additionally, the chapter highlights recent innovations and anticipates future directions in exosome research, emphasizing their applicability in clinical settings. Exosomes have the unique ability to navigate through tissue spaces to enter the circulatory system, positioning them as key players in tissue repair. Their contributory role in various processes of tissue repair, although in the nascent stages of investigation, stands out as a promising area of research. These vesicles function as a complex signaling network for intracellular and organ-level communication, critical in both pathological and physiological contexts. The chapter further explores the tissue-specific functionality of exosomes and underscores the advancements in methodologies for their isolation and purification, which have been instrumental in expanding the scope of exosome research. The differential cargo profiles of exosomes, dependent on their cellular origin, position them as prospective diagnostic biomarkers for tissue damage and regenerative processes. Looking ahead, the trajectory of exosome research is anticipated to bring transformative changes to biomedical fields. This includes advancing diagnostic and prognostic techniques that utilize exosomes as non-invasive biomarkers for a plethora of diseases, such as cancer, neurodegenerative, and cardiovascular conditions. Additionally, engineering exosomes through alterations of their native content or surface properties presents a novel frontier, including the synthesis of artificial or hybrid variants with enhanced functional properties. Concurrently, the ethical and regulatory frameworks surrounding exosome research, particularly in clinical translation, will require thorough deliberation. In conclusion, the diverse aspects of exosome research are coalescing to redefine the frontiers of diagnostic and therapeutic methodologies, cementing its importance as a discipline of considerable consequence in the biomedical sciences.

Adipose-Derived Stem Cell Exosomes Alleviate Psoriasis Serum Exosomes-Induced Inflammation by Regulating Autophagy and Redox Status in Keratinocytes

Introduction

Exosomes play a key role in cell communication and are involved in both pathological and physiological processes. Autophagy dysfunction and oxidative stress are linked to immune-mediated inflammatory diseases such as psoriasis. Stem cell-derived exosomes exhibit immunomodulatory and antioxidant efficacy.

Methods

We aimed to investigate the impact of psoriasis serum-derived exosomes on inflammation, oxidative stress, and autophagy in keratinocytes. Additionally, we explored the therapeutic potential of adipose-derived stem cell (ADSC) exosomes against inflammation induced by psoriasis serum exosomes. To validate psoriasis patient serum-derived exosomes and ADSC exosomes, we used nanoparticle tracking analysis, Western blotting, flow cytometry, and immunofluorescence. qPCR was used to study changes in the gene expression of proinflammatory cytokines and oxidative stress markers in HaCaT cells treated with psoriasis serum-derived exosomes or ADSC exosomes. The effects of these exosomes on autophagy in HaCaT cells were evaluated by Western blotting and immunofluorescence.

Result

The treatment of HaCaT cells with psoriasis serum-derived exosomes increased proinflammatory cytokine production and oxidative stress-related factor (Nox2 and Nox4) expression and decreased Nrf2 expression via P65/NF-κB and P38/MAPK activation. Compared with healthy control serum-derived exosomes, psoriasis serum-derived exosomes decreased ATG5, P62, Beclin1, and LC3 expression and autophagosome production in HaCaT cells. Conversely, ADSC exosomes suppressed proinflammatory cytokine and oxidative stress production, and restored autophagy in HaCaT cells treated with psoriasis serum-derived exosomes.

Discussion

These findings suggest that ADSC exosomes exhibit a suppressive effect on psoriasis serum exosome-induced inflammation and oxidative stress by regulating autophagy in keratinocytes.

Innovative preconditioning strategies for improving the therapeutic efficacy of extracellular vesicles derived from mesenchymal stem cells in gastrointestinal diseases

Gastrointestinal (GI) diseases have become a global health issue and an economic burden due to their wide distribution, late prognosis, and the inefficacy of recent available medications. Therefore, it is crucial to search for new strategies for their management. In the recent decades, mesenchymal stem cells (MSCs) therapy has attracted attention as a viable option for treating a myriad of GI disorders such as hepatic fibrosis (HF), ulcerative colitis (UC), acute liver injury (ALI), and non-alcoholic fatty liver disease (NAFLD) due to their regenerative and paracrine properties. Importantly, recent studies have shown that MSC-derived extracellular vesicles (MSC-EVs) are responsible for most of the therapeutic effects of MSCs. In addition, EVs have revealed several benefits over their parent MSCs, such as being less immunogenic, having a lower risk of tumour formation, being able to cross biological barriers, and being easier to store. MSC-EVs exhibited regenerative, anti-oxidant, anti-inflammatory, anti-apoptotic, and anti-fibrotic effects in different experimental models of GI diseases. However, a key issue with their clinical application is the maintenance of their stability and efficacy following in vivo transplantation. Preconditioning of MSC-EVs or their parent cells is one of the novel methods used to improve their effectiveness and stability. Herein, we discuss the application of MSC-EVs in several GI disorders taking into account their mechanism of action. We also summarise the challenges and restrictions that need to be overcome to promote their clinical application in the treatment of various GI diseases as well as the recent developments to improve their effectiveness. A representation of the innovative preconditioning techniques that have been suggested for improving the therapeutic efficacy of MSC-EVs in GI diseases. The pathological conditions in various GI disorders (ALI, UC, HF and NAFLD) create a harsh environment for EVs and their parents, increasing the risk of apoptosis and senescence of MSCs and thereby diminishing MSC-EVs yield and restricting their large-scale applications. Preconditioning with pharmacological agents or biological mediators can improve the therapeutic efficacy of MSC-EVs through their adaption to the lethal environment to which they are subjected. This can result in establishment of a more conducive environment and activation of numerous vital trajectories that act to improve the immunomodulatory, reparative and regenerative activities of the derived EVs, as a part of MSCs paracrine system. ALI, acute liver injury; GI diseases, gastrointestinal diseases; HF, hepatic fibrosis; HSP, heat shock protein; miRNA, microRNA; mRNA, messenger RNA; MSC-EVs, mesenchymal stem cell-derived extracellular vesicles; NAFLD, non-alcoholic fatty liver disease; UC, ulcerative colitis.

Urinary exosomes: a promising biomarker of drug-induced nephrotoxicity

Drug-induced nephrotoxicity (DIN) is a big concern for clinical medication, but the clinical use of certain nephrotoxic drugs is still inevitable. Current testing methods make it hard to detect early renal injury accurately. In addition to understanding the pathogenesis and risk factors of drug-induced nephrotoxicity, it is crucial to identify specific renal injury biomarkers for early detection of DIN. Urine is an ideal sample source for biomarkers related to kidney disease, and urinary exosomes have great potential as biomarkers for predicting DIN, which has attracted the attention of many scholars. In the present paper, we will first introduce the mechanism of DIN and the biogenesis of urinary exosomes. Finally, we will discuss the changes in urinary exosomes in DIN and compare them with other predictive indicators to enrich and boost the development of biomarkers of DIN.

Premature ovarian insufficiency: a review on the role of oxidative stress and the application of antioxidants

Normal levels of reactive oxygen species (ROS) play an important role in regulating follicular growth, angiogenesis and sex hormone synthesis in ovarian tissue. When the balance between ROS and antioxidants is disrupted, however, it can cause serious consequences of oxidative stress (OS), and the quantity and quality of oocytes will decline. Therefore, this review discusses the interrelationship between OS and premature ovarian insufficiency (POI), the potential mechanisms and the methods by which antioxidants can improve POI through controlling the level of OS. We found that OS can mediate changes in genetic materials, signal pathways, transcription factors and ovarian microenvironment, resulting in abnormal apoptosis of ovarian granulosa cells (GCs) and abnormal meiosis as well as decreased mitochondrial Deoxyribonucleic Acid(mtDNA) and other changes, thus accelerating the process of ovarian aging. However, antioxidants, mesenchymal stem cells (MSCs), biological enzymes and other antioxidants can delay the disease process of POI by reducing the ROS level in vivo.

Activation of the Akt/FoxO3 signaling pathway enhances oxidative stress-induced autophagy and alleviates brain damage in a rat model of ischemic stroke

Autophagy has been implicated in stroke. Our previous study showed that the FoxO3 transcription factor promotes autophagy after transient cerebral ischemia/reperfusion (I/R). However, whether the Akt/FoxO3 signaling pathway plays a regulatory role in autophagy in cerebral I/R-induced oxidative stress injury is still unclear. The present study aims to investigate the effects of the Akt/FoxO3 signaling pathway on autophagy activation and neuronal injury in vitro and in vivo. By employing LY294002 or insulin to regulate the Akt/FoxO3 signaling pathway, we found that insulin pretreatment increased cell viability, decreased reactive oxygen species production, and enhanced the expression of antiapoptotic and autophagy-related proteins following H₂O₂ injury in HT22 cells. In addition, insulin significantly decreased neurological deficit scores and infarct volume and increased the expression of antiapoptotic and autophagy-related proteins following I/R injury in rats. However, LY294002 showed the opposite effects under these conditions. Altogether, these results indicate that Akt/FoxO3 signaling pathway activation inhibited oxidative stress-mediated cell death through activation of autophagy. Our study supports a critical role for the Akt/FoxO3 signaling pathway in autophagy activation in stroke.

Exosomes of Whartons' jelly mesenchymal stem cell reduce the NOX genes in TGF-β-induced hepatic fibrosis

Objectives

Activated cells which are called star-shaped cells, are some of the key factors in the development of liver fibrosis. Activation of NADPH oxidase (NOX) is associated with increased HSCs activity and progression of hepatic fibrosis. In this study, the effects of human exosomes derived from WJ-MSCs on NOX1, NOX2, and NOX4 gene expression in TGF-β-induced hepatic fibrosis were investigated.

Materials and Methods

LX2 cell line was treated with 2 ng/ml TGF-β for 24 hr, in order to induce liver fibrosis after starvation. In the next step, the cells were treated with several concentrations of the exosomes derived from WJ-MSCs (10, 20, 30, 40, and 50 μg/ml). Finally, Smad3C phosphorylated protein expression level and NOX1, NOX2, and NOX4 gene expression levels were measured.

Results

The results demonstrated that the level of NOX1, NOX2, and NOX4 mRNA expressions decreased significantly during 24 hrs at concentrations of 40 and 50 μg/ml of WJ-MSCs exosomes in TGF-β-induced-HSCs. The p-Smad3C proteins were significantly decreased (fold change: 1.83, P-value<0.05) after exposure to WJ-MSC-derived exosomes.

Conclusion

Treatment with exosomes prevents further activation of HSCs by inhibiting the level of Smad3C phosphorylation. The experimental data of our study suggested that in liver fibrosis, the protection of HSCs activation against TGF-β by inhibiting the NOX pathway via human exosomes of WJ-MSCs is extremely important. It needs further research as a treatment method.