MSC-derived exosomes protect against oxidative stress-induced skin injury via adaptive regulation of the NRF2 defense system

Nrf2 Signaling Pathway: Focus on Oxidative Stress in Spinal Cord Injury

Spinal cord injury (SCI) is a serious, disabling injury to the central nervous system that can lead to motor, sensory, and autonomic dysfunction below the injury plane. SCI can be divided into primary injury and secondary injury according to its pathophysiological process. Primary injury is irreversible in most cases, while secondary injury is a dynamic regulatory process. Secondary injury involves a series of pathological events, such as ischemia, oxidative stress, inflammatory events, apoptotic pathways, and motor dysfunction. Among them, oxidative stress is an important pathological event of secondary injury. Oxidative stress causes a series of destructive events such as lipid peroxidation, DNA damage, inflammation, and cell death, which further worsens the microenvironment of the injured site and leads to neurological dysfunction. The nuclear factor erythrocyte 2-associated factor 2 (Nrf2) is considered to be a key pathway of antioxidative stress and is closely related to the pathological process of SCI. Activation of this pathway can effectively inhibit the oxidative stress process and promote the recovery of nerve function after SCI. Therefore, the Nrf2 pathway may be a potential therapeutic target for SCI. This review deeply analyzed the generation of oxidative stress in SCI, the role and mechanism of Nrf2 as the main regulator of antioxidant stress in SCI, and the influence of cross-talk between Nrf2 and related pathways that may be involved in the pathological regulation of SCI on oxidative stress, and summarized the drugs and other treatment methods based on Nrf2 pathway regulation. The objective of this paper is to provide evidence for the role of Nrf2 activation in SCI and to highlight the important role of Nrf2 in alleviating SCI by elucidating the mechanism, so as to provide a theoretical basis for targeting Nrf2 pathway as a therapy for SCI.

Human umbilical cord mesenchymal stem cells alleviate chemotherapy-induced premature ovarian insufficiency mouse model by suppressing ferritinophagy-mediated ferroptosis in granulosa cells

Primary ovarian insufficiency (POI) in younger women (under 40) manifests as irregular periods, high follicle-stimulating hormone (FSH), and low estradiol (E2), often triggered by chemotherapy. Though mesenchymal stem cell (MSC) therapy shows promise in treating POI, its exact mechanism remains unclear. This study reveals that human umbilical cord-derived MSCs (hUC-MSCs) can protect ovarian granulosa cells (GCs) from cyclophosphamide (CTX)-induced ferroptosis, a form of cell death driven by iron accumulation. CTX, commonly used to induce POI animal model, triggered ferroptosis in GCs, while hUC-MSCs treatment mitigated this effect, both in vivo and in vitro. Further investigations using ferroptosis and autophagy inhibitors suggest that hUC-MSCs act by suppressing ferroptosis in GCs. Interestingly, hUC-MSCs activate a protective antioxidant pathway in GCs via NRF2, a stress-response regulator. Overall, our findings suggest that hUC-MSCs improve ovarian function in CTX-induced POI by reducing ferroptosis in GCs. This study not only clarifies the mechanism behind the benefits of hUC-MSCs but also strengthens the case for their clinical use in treating POI. Additionally, it opens up a new avenue for protecting ovaries from chemotherapy-induced damage by regulating ferroptosis.

Adipose-Derived Mesenchymal Stem Cells and Their Derived Epidermal Progenitor Cells Conditioned Media Ameliorate Skin Aging in Rats

BACKGROUND

Skin alterations are among the most prominent signs of aging, and they arise from both intrinsic and extrinsic factors that interact and mutually influence one another. The use of D-galactose as an aging model in animals has been widely employed in anti-aging research. Adipose tissue-derived mesenchymal stem cells (Ad-MSCs) are particularly promising for skin anti-aging therapy due to their capacity for effective re-epithelization and secretion of various growth factors essential for skin regeneration. Accordingly, we aimed to examine the potential utility of Ad-MSCs as a therapy for skin anti-aging.

METHODS

In this study, we isolated and characterized adipose-derived mesenchymal stem cells (Ad-MSCs) from the epididymal fat of male Sprague Dawley rats. We assessed the in vitro differentiation of Ad-MSCs into epidermal progenitor cells (EPCs) using ascorbic acid and hydrocoritsone. Additionally, we induced skin aging in female Sprague Dawley rats via daily intradermal injection of D-galactose over a period of 8 weeks. Then we evaluated the therapeutic potential of intradermal transplantation of Ad-MSCs and conditioned media (CM) derived from differentiated EPCs in the D-galactose-induced aging rats. Morphological assessments, antioxidant assays, and histopathological examinations were performed to investigate the effects of the treatments.

RESULTS

Our findings revealed the significant capability of Ad-MSCs to differentiate into EPCs. Notably, compared to the group that received CM treatment, the Ad-MSCs-treated group exhibited a marked improvement in morphological appearance, antioxidant levels and histological features.

CONCLUSIONS

These results underscore the effectiveness of Ad-MSCs in restoring skin aging as a potential therapy for skin aging.

Hybrid hair follicle stem cell extracellular vesicles co-delivering finasteride and gold nanoparticles for androgenetic alopecia treatment

Androgenetic alopecia (AGA) is a non-fatal disease prevalent worldwide. However, mixed efficacy has been observed among different therapies for hair regrowth in AGA patients. Thus, a nano-platform with synergistic treatments based on a hybrid extracellular vesicle encapsulating gold nanoparticles (AuNPs) and finasteride (Hybrid/Au@Fi) was constructed through membrane fusion between hair follicle stem cell (HFSC)-derived extracellular vesicles and liposomes. These hybrid vesicles (HVs) not only fuel hair regrowth by providing cellular signals in extracellular vesicles, but also improve storage stability, follicle retention, and drug encapsulation efficiency (EE%) for finasteride inhibiting 5α-reductase, and nano-size AuNPs that simulate low-level laser therapy (LLLT) with similar photothermal effects in vitro. The EE% of finasteride in these HVs reached 45.33%. The dual administration of these extracellular vesicles and finasteride showed a strong synergistic effect on HFSCs in vitro. In an AGA mouse model, once-daily topical Hybrid/Au@Fi (115.07 ± 0.32 nm, -7.50 ± 1.68 mV) gel led to a faster transition of hair follicles (HFs) from the catagen to the anagen, increased hair regrowth coverage, and higher quality of regrowth hair, compared to once-daily 5% minoxidil treatment. Compared to topical minoxidil, the multifaceted synergistic therapy of Hybrid/Au@Fi through topical administration offers a new option for intractable AGA patients with low side effects.

Bone Marrow Mesenchymal Stem Cells-derived Exosomes Promote Survival of Random Flaps in Rats through Nrf2-mediated Antioxidative Stress

BACKGROUND

 Random flaps are the most used defect repair method for head and neck tumors and trauma plastic surgery. The distal part of the flap often undergoes oxidative stress (OS), ultimately leading to flap necrosis. Stem cells' exosomes exhibit potential effects related to anti-inflammatory, regenerative, and antioxidant properties. Nuclear factor erythroid-2-related factor 2 (Nrf2) is an important factor in regulating oxidative balance. Exosomes have been reported to monitor its transcription to alleviate OS. This study examined the impacts and underlying mechanisms of antioxidant actions of exosomes derived from bone marrow mesenchymal stem cells (BMSCs-Exo) on random flaps.

METHODS

 BMSCs-Exo were injected into the tail veins of rats on days 0, 1, and 2 after surgery of random flaps. The rats were euthanized on day 3 to calculate the survival rate. Immunohistochemical staining, western blotting, dihydroethidium probe, superoxide dismutase, and malondialdehyde assay kits were used to detect the OS level. Human umbilical vein endothelial cells were cocultured with BMSCs-Exo and ML385 (an inhibitor of Nrf2) in vitro.

RESULTS

 BMSCs-Exo may significantly improve the survival rate of the random flaps by reducing apoptosis, inflammation, and OS while increasing angiogenesis. Besides, BMSCs-Exo can also increase mitochondrial membrane potential and reduce reactive oxygen species levels in vitro. These therapeutic effects might stem from the activation of the Kelch-like enyol-CoA hydratase (ECH)-associated protein 1 (Keap1)/Nrf2 signaling pathway.

CONCLUSION

 BMSCs-Exo improved the tissue antioxidant capacity by regulating the Keap1/Nrf2 signaling pathway. BMSCs-Exo may be a new strategy to solve the problem of random flap necrosis.

Antioxidant Activity and the Therapeutic Effect of Sinomenine Hydrochloride-Loaded Liposomes-in-Hydrogel on Atopic Dermatitis

Sinomenine hydrochloride is an excellent drug with anti-inflammatory, antioxidant, immune-regulatory, and other functions. Atopic dermatitis is an inherited allergic inflammation that causes itchiness, redness, and swelling in the affected area, which can have a significant impact on the life of the patient. There are many therapeutic methods for atopic dermatitis, and sinomenine with immunomodulatory activity might be effective in the treatment of atopic dermatitis. In this study, the atopic dermatitis model was established in experimental mice, and physical experiments were carried out on the mice. In the experiment, sinomenine hydrochloride liposomes-in-hydrogel as a new preparation was selected for delivery. In this case, liposomes were dispersed in the colloidal hydrogel on a mesoscopic scale and could provide specific transfer properties. The results showed that the sinomenine hydrochloride-loaded liposomes-in-hydrogel system could effectively inhibit atopic dermatitis.

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.

TaoHe ChengQi decoction ameliorates sepsis-induced cardiac dysfunction through anti-ferroptosis via the Nrf2 pathway

BACKGROUND

Sepsis-induced cardiac dysfunction (SICD) is a serious complication of sepsis that is associated with increased mortality. Ferroptosis has been reported in the SICD. TaoHe ChengQi decoction (THCQD), a classical traditional Chinese medicinal formula, has multiple beneficial pharmacological effects. The potential effects of THCQD on the SICD remain unknown.

PURPOSE

To investigate the effect of THCQD on SICD and explore whether this effect is related to the regulation of myocardial ferroptosis through nuclear factor erythroid 2-related factor 2 (Nrf2) activation.

METHODS

We induced sepsis in a mouse model using cecal ligation and puncture (CLP) and administered THCQD (2 and 4 g/kg) and dexamethasone (40 mg/kg). Mice mortality was recorded and survival curves were plotted. Echocardiography, hematoxylin and eosin staining, and analysis of serum myocardial injury markers and inflammatory factors were used to evaluate cardiac pathology. Myocardial ferroptosis was detected by quantifying specific biomarker content and protein levels. Through HPLC-Q-Exactive-MS analysis, we identified the components of the THCQD. Network pharmacology analysis and Cellular Thermal Shift Assay (CETSA) were utilized to predict the targets of THCQD for treating SICD. We detected the expression of Nrf2 using Western blotting or immunofluorescence. An RSL3-induced ferroptosis model was established using neonatal rat cardiomyocytes (NRCMs) to further explore the pharmacological mechanism of THCQD. In addition to measuring cell viability, we observed changes in NRCM mitochondria using electron microscopy and JC-1 staining. NRF2 inhibitor ML385 and Nrf2 knockout mice were used to validate whether THCQD exerted protective effects against SICD through Nrf2-mediated ferroptosis signaling.

RESULTS

THCQD reduced mortality in septic mice, protected against CLP-induced myocardial injury, decreased systemic inflammatory response, and prevented myocardial ferroptosis. Network pharmacology analysis and CETSA experiments predicted that THCQD may protect against SICD by activating the Nrf2 signaling pathway. Western blotting and immunofluorescence showed that THCQD activated Nrf2 in cardiac tissue. THCQDs consistently mitigated RSL3-induced ferroptosis in NRCM, which is related to Nrf2. Furthermore, the pharmacological inhibition of Nrf2 and genetic Nrf2 knockout partially reversed the protective effects of THCQD on SICD and ferroptosis.

CONCLUSION

The effect of THCQD on SICD was achieved by activating Nrf2 and its downstream pathways.

Mesenchymal stem cells-extracellular vesicles alleviate pulmonary fibrosis by regulating immunomodulators

BACKGROUND

Pulmonary fibrosis (PF) is a chronic interstitial lung disease characterized by fibroblast proliferation and extracellular matrix formation, causing structural damage and lung failure. Stem cell therapy and mesenchymal stem cells-extracellular vesicles (MSC-EVs) offer new hope for PF treatment.

AIM

To investigate the therapeutic potential of MSC-EVs in alleviating fibrosis, oxidative stress, and immune inflammation in A549 cells and bleomycin (BLM)-induced mouse model.

METHODS

The effect of MSC-EVs on A549 cells was assessed by fibrosis markers [collagen I and α-smooth muscle actin (α-SMA), oxidative stress regulators [nuclear factor E2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1), and inflammatory regulators [nuclear factor-kappaB (NF-κB) p65, interleukin (IL)-1β, and IL-2]. Similarly, they were assessed in the lungs of mice where PF was induced by BLM after MSC-EV transfection. MSC-EVs ion PF mice were detected by pathological staining and western blot. Single-cell RNA sequencing was performed to investigate the effects of the MSC-EVs on gene expression profiles of macrophages after modeling in mice.

RESULTS

Transforming growth factor (TGF)-β1 enhanced fibrosis in A549 cells, significantly increasing collagen I and α-SMA levels. Notably, treatment with MSC-EVs demonstrated a remarkable alleviation of these effects. Similarly, the expression of oxidative stress regulators, such as Nrf2 and HO-1, along with inflammatory regulators, including NF-κB p65 and IL-1β, were mitigated by MSC-EV treatment. Furthermore, in a parallel manner, MSC-EVs exhibited a downregulatory impact on collagen deposition, oxidative stress injuries, and inflammatory-related cytokines in the lungs of mice with PF. Additionally, the mRNA sequencing results suggested that BLM may induce PF in mice by upregulating pulmonary collagen fiber deposition and triggering an immune inflammatory response. The findings collectively highlight the potential therapeutic efficacy of MSC-EVs in ameliorating fibrotic processes, oxidative stress, and inflammatory responses associated with PF.

CONCLUSION

MSC-EVs could ameliorate fibrosis in vitro and in vivo by downregulating collagen deposition, oxidative stress, and immune-inflammatory responses.

Mesenchymal stem cells-extracellular vesicles alleviate pulmonary fibrosis by regulating immunomodulators

BACKGROUND

Pulmonary fibrosis (PF) is a chronic interstitial lung disease characterized by fibroblast proliferation and extracellular matrix formation, causing structural damage and lung failure. Stem cell therapy and mesenchymal stem cells-extracellular vesicles (MSC-EVs) offer new hope for PF treatment.

AIM

To investigate the therapeutic potential of MSC-EVs in alleviating fibrosis, oxidative stress, and immune inflammation in A549 cells and bleomycin (BLM)-induced mouse model.

METHODS

The effect of MSC-EVs on A549 cells was assessed by fibrosis markers [collagen I and α-smooth muscle actin (α-SMA), oxidative stress regulators [nuclear factor E2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1), and inflammatory regulators [nuclear factor-kappaB (NF-κB) p65, interleukin (IL)-1β, and IL-2]. Similarly, they were assessed in the lungs of mice where PF was induced by BLM after MSC-EV transfection. MSC-EVs ion PF mice were detected by pathological staining and western blot. Single-cell RNA sequencing was performed to investigate the effects of the MSC-EVs on gene expression profiles of macrophages after modeling in mice.

RESULTS

Transforming growth factor (TGF)-β1 enhanced fibrosis in A549 cells, significantly increasing collagen I and α-SMA levels. Notably, treatment with MSC-EVs demonstrated a remarkable alleviation of these effects. Similarly, the expression of oxidative stress regulators, such as Nrf2 and HO-1, along with inflammatory regulators, including NF-κB p65 and IL-1β, were mitigated by MSC-EV treatment. Furthermore, in a parallel manner, MSC-EVs exhibited a downregulatory impact on collagen deposition, oxidative stress injuries, and inflammatory-related cytokines in the lungs of mice with PF. Additionally, the mRNA sequencing results suggested that BLM may induce PF in mice by upregulating pulmonary collagen fiber deposition and triggering an immune inflammatory response. The findings collectively highlight the potential therapeutic efficacy of MSC-EVs in ameliorating fibrotic processes, oxidative stress, and inflammatory responses associated with PF.

CONCLUSION

MSC-EVs could ameliorate fibrosis in vitro and in vivo by downregulating collagen deposition, oxidative stress, and immune-inflammatory responses.

Engineering extracellular vesicles for ROS scavenging and tissue regeneration

Stem cell therapy holds promise for tissue regeneration, yet significant challenges persist. Emerging as a safer and potentially more effective alternative, extracellular vesicles (EVs) derived from stem cells exhibit remarkable abilities to activate critical signaling cascades, thereby facilitating tissue repair. EVs, nano-scale membrane vesicles, mediate intercellular communication by encapsulating a diverse cargo of proteins, lipids, and nucleic acids. Their therapeutic potential lies in delivering cargos, activating signaling pathways, and efficiently mitigating oxidative stress-an essential aspect of overcoming limitations in stem cell-based tissue repair. This review focuses on engineering and applying EVs in tissue regeneration, emphasizing their role in regulating reactive oxygen species (ROS) pathways. Additionally, we explore strategies to enhance EV therapeutic activity, including functionalization and incorporation of antioxidant defense proteins. Understanding these molecular mechanisms is crucial for optimizing EV-based regenerative therapies. Insights into EV and ROS signaling modulation pave the way for targeted and efficient regenerative therapies harnessing the potential of EVs.

Aging and homeostasis of the hypodermis in the age-related deterioration of skin function

Adipose tissues in the hypodermis, the crucial stem cell reservoir in the skin and the endocrine organ for the maintenance of skin homeostasis undergo significant changes during skin aging. Dermal white adipose tissue (dWAT) has recently been recognized as an important organ for both non-metabolic and metabolic health in skin regeneration and rejuvenation. Defective differentiation, adipogenesis, improper adipocytokine production, and immunological dissonance dysfunction in dWAT lead to age-associated clinical changes. Here, we review age-related alterations in dWAT across levels, emphasizing the mechanisms underlying the regulation of aging. We also discuss the pathogenic changes involved in age-related fat dysfunction and the unfavorable consequences of accelerated skin aging, such as chronic inflammaging, immunosenescence, delayed wound healing, and fibrosis. Research has shown that adipose aging is an early initiation event and a potential target for extending longevity. We believe that adipose tissues play an essential role in aging and form a potential therapeutic target for the treatment of age-related skin diseases. Further research is needed to improve our understanding of this phenomenon.

Mitigation of Oxidative Stress in Idiopathic Pulmonary Fibrosis Through Exosome-Mediated Therapies

Idiopathic pulmonary fibrosis (IPF) poses a formidable clinical challenge, characterized by the thickening of alveolar septa and the onset of pulmonary fibrosis. The pronounced activation of oxidative stress emerges as a pivotal hallmark of inflammation. Traditional application of exogenous antioxidants proves inadequate in addressing oxidative stress, necessitating exploration into strategies to augment their antioxidant efficacy. Exosomes, nano-sized extracellular vesicles harboring a diverse array of bioactive factors, present as promising carriers with the potential to meet this challenge. Recent attention has been directed towards the clinical applications of exosomes in IPF, fueling the impetus for this comprehensive review. We have compiled fresh insights into the role of exosomes in modulating oxidative stress in IPF and delved into their potential as carriers for regulating endogenous reactive oxygen species generation. This review endeavors to bridge the divide between exosome research and IPF, traversing from bedside to bench. Through the synthesis of recent findings, we propose exosomes as a novel and promising strategy for improving the outcomes of IPF therapy.

3D-hUMSCs Exosomes Ameliorate Vitiligo by Simultaneously Potentiating Treg Cells-Mediated Immunosuppression and Suppressing Oxidative Stress-Induced Melanocyte Damage

Vitiligo is an autoimmune disease characterized by epidermal melanocyte destruction, with abnormal autoimmune responses and excessive oxidative stress as two cardinal mechanisms. Human umbilical mesenchymal stem cells-derived exosomes (hUMSCs-Exos) are regarded as promising therapeutic choice for autoimmune diseases due to potent immunosuppressive and anti-oxidative properties, which can be potentiated under 3D cell culture condition. Nevertheless, whether exosomes derived from 3D spheroids of hUMSCs (3D-Exos) exhibit considerable therapeutic effect on vitiligo and the underlying mechanism remain elusive. In this study, systemic administration of 3D-Exos showed a remarkable effect in treating mice with vitiligo, as revealed by ameliorated skin depigmentation, less CD8+T cells infiltration, and expanded Treg cells in skin, and 3D-Exos exerted a better effect than 2D-Exos. Mechanistically, 3D-Exos can prominently facilitate the expansion of Treg cells in vitiligo lesion and suppress H2O2-induced melanocytes apoptosis. Forward miRNA profile analysis and molecular experiments have demonstrated that miR-132-3p and miR-125b-5p enriched in 3D-Exos greatly contributed to these biological effects by targeting Sirt1 and Bak1 respectively. In aggregate, 3D-Exos can efficiently ameliorate vitiligo by simultaneously potentiating Treg cells-mediated immunosuppression and suppressing oxidative stress-induced melanocyte damage via the delivery of miR-132-3p and miR-125b-5p. The employment of 3D-Exos will be a promising treament for vitiligo.

Regulation of the Nrf2/HO-1 axis by mesenchymal stem cells-derived extracellular vesicles: implications for disease treatment

This comprehensive review inspects the therapeutic potential of mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) across multiple organ systems. Examining their impact on the integumentary, respiratory, cardiovascular, urinary, and skeletal systems, the study highlights the versatility of MSC-EVs in addressing diverse medical conditions. Key pathways, such as Nrf2/HO-1, consistently emerge as central mediators of their antioxidative and anti-inflammatory effects. From expediting diabetic wound healing to mitigating oxidative stress-induced skin injuries, alleviating acute lung injuries, and even offering solutions for conditions like myocardial infarction and renal ischemia-reperfusion injury, MSC-EVs demonstrate promising therapeutic efficacy. Their adaptability to different administration routes and identifying specific factors opens avenues for innovative regenerative strategies. This review positions MSC-EVs as promising candidates for future clinical applications, providing a comprehensive overview of their potential impact on regenerative medicine.

Biomaterials-mediated radiation-induced diseases treatment and radiation protection

In recent years, the intersection of the academic and medical domains has increasingly spotlighted the utilization of biomaterials in radioactive disease treatment and radiation protection. Biomaterials, distinguished from conventional molecular pharmaceuticals, offer a suite of advantages in addressing radiological conditions. These include their superior biological activity, chemical stability, exceptional histocompatibility, and targeted delivery capabilities. This review comprehensively delineates the therapeutic mechanisms employed by various biomaterials in treating radiological afflictions impacting the skin, lungs, gastrointestinal tract, and hematopoietic systems. Significantly, these nanomaterials function not only as efficient drug delivery vehicles but also as protective agents against radiation, mitigating its detrimental effects on the human body. Notably, the strategic amalgamation of specific biomaterials with particular pharmacological agents can lead to a synergistic therapeutic outcome, opening new avenues in the treatment of radiation- induced diseases. However, despite their broad potential applications, the biosafety and clinical efficacy of these biomaterials still require in-depth research and investigation. Ultimately, this review aims to not only bridge the current knowledge gaps in the application of biomaterials for radiation-induced diseases but also to inspire future innovations and research directions in this rapidly evolving field.

hUCMSC-derived exosomes protect against GVHD-induced endoplasmic reticulum stress in CD4+ T cells by targeting the miR-16-5p/ATF6/CHOP axis

Exosomes generated from mesenchymal stem cells (MSCs) are thought to be a unique therapeutic strategy for several autoimmune deficiency illnesses. The purpose of this study was to elucidate the protective effects of human umbilical cord mesenchymal stem cell-derived exosomes (hUCMSC-Exo) on CD4+ T cells dysfunction during graft-versus-host disease (GVHD) and to identify the underlying processes involved. Here, we showed that hUCMSC-Exo treatment can effectively attenuate GVHD injury by alleviating redox metabolism disorders and inflammatory cytokine bursts in CD4+ T cells. Furthermore, hUCMSC-Exo ameliorate ER stress and ATF6/CHOP signaling-mediated apoptosis in CD4+ T cells and promote the development of CD4+IL-10+ T cells during GVHD. Moreover, downregulating miR-16-5p in hUCMSC-Exo impaired their ability to prevent CD4+ T cells apoptosis and weakened their ability to promote the differentiation of CD4+IL-10+ T cells. Collectively, the obtained data suggested that hUCMSC-Exo suppress ATF6/CHOP signaling-mediated ER stress and apoptosis in CD4+ T cells, enhance the differentiation of CD4+IL-10+ T cells, and reverse the imbalance of immune homeostasis in the GVHD process by transferring miR-16-5p. Our study provided further evidence that GVHD patients can benefit from hUCMSC-Exo-mediated therapy.

Integrative analysis of transcriptomics and metabolomics reveals the protective effect and mechanism of salidroside on testicular ischemia-reperfusion injury

Testicular torsion is a critical urologic condition for which testicular detorsion surgery is considered irreplaceable as well as the golden method of reversal. However, the surgical treatment is equivalent to a blood reperfusion process, and no specific drugs are available to treat blood reperfusion injuries. Salidroside (SAL) is one of the main effective substances in rhodiola, which has been shown to have antioxidant and antiapoptosis activities. This study was designed to determine whether SAL exerted a protective effect on testicular ischemia-reperfusion (I/R) injury. In this study, the I/R injury model of the testes and reoxygenation (OGD/R) model were used for verification, and SAL was administered at doses of 100 mg/kg and 0.05 mmol/L, respectively. After the experiments, the testicular tissue and TM4 Sertoli cells were collected for histopathologic and biochemical analyses. The results revealed that SAL improves the structure of testicular tissue and regulates the oxidation-antioxidation system. To further understand the molecular mechanisms of SAL in treating testicular I/R injuries, transcriptomics and metabonomics analyses were integrated. The results show that the Nfr2/HO-1/GPX4/ferroptosis signaling pathway is enriched significantly, indicating that it may be the main regulatory pathway for SAL in the treatment of testicular I/R injuries. Thereafter, transfection with Nrf2 plasmid-liposome was used to reverse verify that the Nfr2/HO-1/GPX4/ferroptosis signaling pathway was the main pathway for SAL anti-testicular I/R injury treatment. Thus, it is suggested that SAL can protect against testicular I/R injuries by regulating the Nfr2/HO-1/GPX4 signaling pathway to inhibit ferroptosis and that SAL may be a potential drug for the treatment of testicular I/R injuries.

Drugs/agents for the treatment of ischemic stroke: Advances and perspectives

Ischemic stroke (IS) poses a significant threat to global human health and life. In recent decades, we have witnessed unprecedented progresses against IS, including thrombolysis, thrombectomy, and a few medicines that can assist in reopening the blocked brain vessels or serve as standalone treatments for patients who are not eligible for thrombolysis/thrombectomy therapies. However, the narrow time windows of thrombolysis/thrombectomy, coupled with the risk of hemorrhagic transformation, as well as the lack of highly effective and safe medications, continue to present big challenges in the acute treatment and long-term recovery of IS. In the past 3 years, several excellent articles have reviewed pathophysiology of IS and therapeutic medicines for the treatment of IS based on the pathophysiology. Regretfully, there is no comprehensive overview to summarize all categories of anti-IS drugs/agents designed and synthesized based on molecular mechanisms of IS pathophysiology. From medicinal chemistry view of point, this article reviews a multitude of anti-IS drugs/agents, including small molecule compounds, natural products, peptides, and others, which have been developed based on the molecular mechanism of IS pathophysiology, such as excitotoxicity, oxidative/nitrosative stresses, cell death pathways, and neuroinflammation, and so forth. In addition, several emerging medicines and strategies, including nanomedicines, stem cell therapy and noncoding RNAs, which recently appeared for the treatment of IS, are shortly introduced. Finally, the perspectives on the associated challenges and future directions of anti-IS drugs/agents are briefly provided to move the field forward.

The crosstalk between exosomes and ferroptosis: a review

Exosomes are a subtype of extracellular vesicles composed of bioactive molecules, including nucleic acids, proteins, and lipids. Exosomes are generated by the fusion of intracellular multivesicular bodies (MVBs) with the cell membrane and subsequently released into the extracellular space to participate in intercellular communication and diverse biological processes within target cells. As a crucial mediator, exosomes have been implicated in regulating ferroptosis-an iron-dependent programmed cell death characterized by lipid peroxide accumulation induced by reactive oxygen species. The involvement of exosomes in iron, lipid, and amino acid metabolism contributes to their regulatory role in specific mechanisms underlying how exosomes modulate ferroptosis, which remains incompletely understood, and some related studies are still preliminary. Therefore, targeting the regulation of ferroptosis by exosomes holds promise for future clinical treatment strategies across various diseases. This review aims to provide insights into the pathophysiology and mechanisms governing the interaction between exosomes and ferroptosis and their implications in disease development and treatment to serve as a reference for further research.

Human Mesenchymal Stem Cell-Derived Exosomes Promote the Proliferation and Melanogenesis of Primary Melanocytes by Attenuating the H2O2-Related Cytotoxicity in vitro

Background

Mesenchymal stem cell-derived exosomes (MSC-Exo) have therapeutic potential. However, the impact of MSC-Exo on the survival and melanogenesis of human primary melanocytes following H2O2-induced damage has not been clarified. We therefore investigated the effects of MSC-Exo on the H2O2-affected survival of human primary melanocytes and their proliferation, apoptosis, senescence, and melanogenesis in vitro.

Methods

MSC-Exo were prepared from human MSCs by sequential centrifugations and characterized by Transmission Electron Microscopy, Western blot and Nanoparticle Tracking Analysis. Human primary melanocytes were isolated and treated with different concentrations of MSC-Exo, followed by exposing to H2O2. Furthermore, the impact of pretreatment with MSC-Exo on the proliferation, apoptosis, senescence and melanogenesis of melanocytes were tested by CCK-8, flow cytometry, Western blot, L-Dopa staining, tyrosinase activity and RT-qPCR.

Results

Pretreatment with lower doses of MSC-Exo protected human primary melanocytes from the H2O2-triggered apoptosis, while pretreatment with higher doses of MSC-Exo enhanced the H2O2-induced melanocyte apoptosis. Compared with the untreated control, pretreatment with a lower dose (1 µg/mL) of MSC-Exo enhanced the proliferation of melanocytes, abrogated the H2O2-increased p53, p21, IL-1β, IL-6 and IL-8 expression and partially rescued the H2O2-decreased L-dopa staining reaction, tyrosinase activity, MITF and TRP1 expression in melanocytes.

Conclusion

Our findings indicate that treatment with a low dose of MSC-Exo promotes the proliferation and melanogenesis of human primary melanocytes by ameliorating the H2O2-induced apoptosis and senescence of melanocytes. MSC-Exo may be a promising therapeutic strategy of vitiligo.

Nrf2 activation: a key mechanism in stem cell exosomes-mediated therapies

Exosomes are nano-sized membrane extracellular vesicles which can be released from various types of cells. Exosomes originating from inflammatory or injured cells can have detrimental effects on recipient cells, while exosomes derived from stem cells not only facilitate the repair and regeneration of damaged tissues but also inhibit inflammation and provide protective effects against various diseases, suggesting they may serve as an alternative strategy of stem cells transplantation. Exosomes have a fundamental role in communication between cells, through the transfer of proteins, bioactive lipids and nucleic acids (like miRNAs and mRNAs) between cells. This transfer significantly impacts both the physiological and pathological functions of recipient cells. Nuclear factor erythroid 2-related factor 2 (Nrf2), a transcription factor, is able to mitigate damage caused by oxidative stress and inflammation through various signaling pathways. The positive effects resulting from the activation of the Nrf2 signaling pathway in different disorders have been documented in various types of literature. Studies have confirmed that exosomes derived from stem cells could act as Nrf2 effective agonists. However, limited studies have explored the Nrf2 role in the therapeutic effects of stem cell-derived exosomes. This review provides a comprehensive overview of the existing knowledge concerning the role of Nrf2 signaling pathways in the impact exerted by stem cell exosomes in some common diseases.

Exosomes derived from programmed cell death: mechanism and biological significance

Exosomes are nanoscale extracellular vesicles present in bodily fluids that mediate intercellular communication by transferring bioactive molecules, thereby regulating a range of physiological and pathological processes. Exosomes can be secreted from nearly all cell types, and the biological function of exosomes is heterogeneous and depends on the donor cell type and state. Recent research has revealed that the levels of exosomes released from the endosomal system increase in cells undergoing programmed cell death. These exosomes play crucial roles in diseases, such as inflammation, tumors, and autoimmune diseases. However, there is currently a lack of systematic research on the differences in the biogenesis, secretion mechanisms, and composition of exosomes under different programmed cell death modalities. This review underscores the potential of exosomes as vital mediators of programmed cell death processes, highlighting the interconnection between exosome biosynthesis and the regulatory mechanisms governing cell death processes. Furthermore, we accentuate the prospect of leveraging exosomes for the development of innovative biomarkers and therapeutic strategies across various diseases.

Extracellular vesicles derived from mesenchymal stem cells: the wine in Hebe's hands to treat skin aging

Owing to its constant exposure to the external environment and various stimuli, skin ranks among the organs most vulnerable to manifestations of aging. Preventing and delaying skin aging has become one of the prominent research subjects in recent years. Mesenchymal stem cells (MSCs) are multipotent stem cells derived from mesoderm with high self-renewal ability and multilineage differentiation potential. MSC-derived extracellular vesicles (MSC-EVs) are nanoscale biological vesicles that facilitate intercellular communication and regulate biological behavior. Recent studies have shown that MSC-EVs have potential applications in anti-aging therapy due to their anti-inflammatory, anti-oxidative stress, and wound healing promoting abilities. This review presents the latest progress of MSC-EVs in delaying skin aging. It mainly includes the MSC-EVs promoting the proliferation and migration of keratinocytes and fibroblasts, reducing the expression of matrix metalloproteinases, resisting oxidative stress, and regulating inflammation. We then briefly discuss the recently discovered treatment methods of MSC-EVs in the field of skin anti-aging. Moreover, the advantages and limitations of EV-based treatments are also presented.

Utilizing Extracellular Vesicles for Eliminating 'Unwanted Molecules': Harnessing Nature's Structures in Modern Therapeutic Strategies

Extracellular vesicles (EVs) are small phospholipid bilayer-bond structures released by diverse cell types into the extracellular environment, maintaining homeostasis of the cell by balancing cellular stress. This article provides a comprehensive overview of extracellular vesicles, their heterogeneity, and diversified roles in cellular processes, emphasizing their importance in the elimination of unwanted molecules. They play a role in regulating oxidative stress, particularly by discarding oxidized toxic molecules. Furthermore, endoplasmic reticulum stress induces the release of EVs, contributing to distinct results, including autophagy or ER stress transmission to following cells. ER stress-induced autophagy is a part of unfolded protein response (UPR) and protects cells from ER stress-related apoptosis. Mitochondrial-derived vesicles (MDVs) also play a role in maintaining homeostasis, as they carry damaged mitochondrial components, thereby preventing inflammation. Moreover, EVs partake in regulating aging-related processes, and therefore they can potentially play a crucial role in anti-aging therapies, including the treatment of age-related diseases such as Alzheimer's disease or cardiovascular conditions. Overall, the purpose of this article is to provide a better understanding of EVs as significant mediators in both physiological and pathological processes, and to shed light on their potential for therapeutic interventions targeting EV-mediated pathways in various pathological conditions, with an emphasis on age-related diseases.

Extracellular vesicles in the treatment of oxidative stress injury: global research status and trends

Objective: The aim of this study was to conduct a bibliometric analysis of the literature on "Extracellular Vesicles in the Treatment of Oxidative Stress Injury" and to reveal its current status, hot spots and trends. Methods: The relevant literature was obtained from the Web of Science Core Collection (WoSCC) on 29 April 2023. We performed clustering and partnership analysis of authors, institutions, countries, references and keywords in the literature through CiteSpace software and the bibliometric online analysis platform and mapped the relevant knowledge maps. Results: A total of 1,321 relevant publications were included in the bibliometric analysis, with the number of publications in this field increasing year by year. These included 944 "articles" and 377 "reviews". The maximum number of publications published in China is 512, and the maximum number of highly cited publications published in the United States is 20. Based on CiteSpace, the country collaboration network map shows close and stable collaboration among high-productivity countries. Based on WoSCC, there are 1706 relevant research institutions and 119 highly cited elite institutions, among which Kaohsing Chang Gung Men Hosp has the most extensive influence. Studies related to "Extracellular Vesicles in the Treatment of Oxidative Stress Injury" have been published in 548 journals. The keywords of the publications show the main research areas and breakthroughs. Based on WoSCC, the keywords of the research area "Extracellular Vesicles in the Treatment of Oxidative Stress Injury" were found to be as follows: exosome(s), extracellular vesicle(s), oxidative stress, inflammation, mesenchymal stem cells, apoptosis, microRNA (miRNA), mitochondria, biomarker, autophagy, angiogenesis and Alzheimer's disease. Analysis showed that "mesenchymal stem cells", "microRNA", "autophagy", "histology" and "therapeutic" emerged as highly explosive keywords. Conclusion: This study is the first to use visual software and data mining to assess the literature in the field of "Extracellular Vesicles in the Treatment of Oxidative Stress Injury". The research history, research status and direction in this field provide a theoretical basis for its scientific research.

Emerging role of mesenchymal stem cells-derived extracellular vesicles in vascular dementia

Vascular dementia (VD) is a prevalent cognitive disorder among the elderly. Its pathological mechanism encompasses neuronal damage, synaptic dysfunction, vascular abnormalities, neuroinflammation, and oxidative stress, among others. In recent years, extracellular vesicles (EVs) derived from mesenchymal stem cells (MSCs) have garnered significant attention as an emerging therapeutic strategy. Current research indicates that MSC-derived extracellular vesicles (MSC-EVs) play a pivotal role in both the diagnosis and treatment of VD. Thus, this article delves into the recent advancements of MSC-EVs in VD, discussing the mechanisms by which EVs influence the pathophysiological processes of VD. These mechanisms form the theoretical foundation for their neuroprotective effect in VD treatment. Additionally, the article highlights the potential applications of EVs in VD diagnosis. In conclusion, MSC-EVs present a promising innovative treatment strategy for VD. With rigorous research and ongoing innovation, this concept can transition into practical clinical treatment, providing more effective options for VD patients.

Extracellular vesicles for developing targeted hearing loss therapy

Substantial efforts have been made for local administration of small molecules or biologics in treating hearing loss diseases caused by either trauma, genetic mutations, or drug ototoxicity. Recently, extracellular vesicles (EVs) naturally secreted from cells have drawn increasing attention on attenuating hearing impairment from both preclinical studies and clinical studies. Highly emerging field utilizing diverse bioengineering technologies for developing EVs as the bioderived therapeutic materials, along with artificial intelligence (AI)-based targeting toolkits, shed the light on the unique properties of EVs specific to inner ear delivery. This review will illuminate such exciting research field from fundamentals of hearing protective functions of EVs to biotechnology advancement and potential clinical translation of functionalized EVs. Specifically, the advancements in assessing targeting ligands using AI algorithms are systematically discussed. The overall translational potential of EVs is reviewed in the context of auditory sensing system for developing next generation gene therapy.

The mechanism of adipose mesenchymal stem cells to stabilize the immune microenvironment of pelvic floor injury by regulating pyroptosis and promoting tissue repair

Pelvic organ prolapse (POP) has a high incidence rate among Chinese women. Repeated mechanical stimulation is an important factor causing POP, but the injury mechanism has not yet been elucidated. The purpose of this study is to explore the related mechanisms of pelvic floor supporting tissue damage caused by mechanical force and the application of stem cell therapy. First, we obtained vaginal wall and sacral ligament tissue samples from clinical patients for examination. Pelvic floor support tissues of POP patients displayed high expression of inflammation and immune disorders. Then, we constructed a rat model of childbirth injury. In vivo and in vitro experiments investigated the key mechanism of pelvic floor support tissue injury caused by mechanical force. We discovered that after mechanical force, a large number of reactive oxygen species (ROS) and macrophages rapidly accumulated in pelvic floor tissues. ROS stimulated macrophages to produce NLRP3 inflammatory complex, induced the release of interleukin (IL-1β) and pyroptosis and exacerbated the inflammatory state of damaged tissues, persisting chronic inflammation of fibroblasts in supporting tissues, thus causing the pelvic floor's extracellular matrix (ECM) collagen metabolic disorder. Resultingly impeding the repair process, thereby causing the onset and progression of the disease. Through their paracrine ability, we discovered that adipose mesenchymal stem cells (ADSCs) could inhibit this series of pathological processes and promote tissue repair, asserting a good therapeutic effect. Simultaneously, to overcome the low cell survival rate and poor therapeutic effect of directly injecting cells, we developed a ROS-responsive PVA@COLI hydrogel with ADSCs. The ROS-scavenging properties of the gel could reshape the site of inflammation injury, enhance cell survival, and play a role in subsequent treatment. The findings of this study could serve as a basis for early, targeted intervention therapy for POP and representing a promising approach.

Translational studies of exosomes in sports medicine - a mini-review

This review in sports medicine focuses on the critical role of exosomes in managing chronic conditions and enhancing athletic performance. Exosomes, small vesicles produced by various cells, are essential for cellular communication and transporting molecules like proteins and nucleic acids. Originating from the endoplasmic reticulum, they play a vital role in modulating inflammation and tissue repair. Their significance in sports medicine is increasingly recognized, particularly in healing athletic injuries, improving articular cartilage lesions, and osteoarthritic conditions by modulating cellular behavior and aiding tissue regeneration. Investigations also highlight their potential in boosting athletic performance, especially through myocytes-derived exosomes that may enhance adaptability to physical training. Emphasizing a multidisciplinary approach, this review underlines the need to thoroughly understand exosome biology, including their pathways and classifications, to fully exploit their therapeutic potential. It outlines future directions in sports medicine, focusing on personalized treatments, clinical evaluations, and embracing technological advancements. This research represents a frontier in using exosomes to improve athletes' health and performance capabilities.

Selenomethionine protects the liver from dietary deoxynivalenol exposure via Nrf2/PPARγ-GPX4-ferroptosis pathway in mice

Deoxynivalenol (DON) is a significant Fusarium toxin that has gained global attention due to its high frequency of contamination in food and feed. It was reported to have hepatotoxicity, immunotoxicity, and reproduction toxicity in organs. On the other hand, Selenomethionine (SeMet) was proven to have anti-oxidation, tissue repairing, immunity improvement, and antifungal mycotoxin infection functions. However, the molecular mechanism by which SeMet alleviates DON damage is not yet clear. C57BL/6 mice were randomly divided into three groups, Se-A and Se-A+DON were fed with a diet containing 0.2 mg/kg Se whereas Se-S+DON were fed with a diet of 1.0 mg/kg Se. After feeding for four weeks, the mice were gavaged for 21 days with DON (2.0 mg/kg BW) or ultrapure water once per day. In the present study, we showed that SeMet significantly decreased the lipid peroxidation product malondialdehyde, and increased activities of antioxidant enzymes superoxide dismutase and total antioxidant capacity after DON exposure. In addition, our investigation revealed that SeMet regulated pathways related to lipid synthesis and metabolisms, and effectively mitigated DON-induced liver damage. Moreover, we have discovered that SeMet downregulation of N-acylethanolamine and HexCer accumulation induced hepatic lipotoxicity. Further study showed that SeMet supplementation increased protein levels of glutathione peroxidase 4 (GPX4), peroxisome proliferator-activated receptor γ (PPARγ), nuclear erythroid 2-related factor 2 (Nrf2), and upregulated target proteins, indicating suppression of oxidative stress in the liver. Meanwhile, we found that SeMet significantly reduced the DON-induced protein abundances of Bcl2, Beclin1, LC3B and proteins related to ferroptosis (Lpcat3, and Slc3a2), and downregulation of Slc7a11. In conclusion, SeMet protected the liver from damage by enhancing the Nrf2/PPARγ-GPX4-ferroptosis pathway, inhibiting lipid accumulation and hepatic lipotoxicity. The findings of this study indicated that SeMet has a positive impact on liver health by improving antioxidant capacity and relieving lipotoxicity in toxin pollution.

Exosomes from hypoxic pretreated ADSCs attenuate ultraviolet light-induced skin injury via GLRX5 delivery and ferroptosis inhibition

Accumulation studies have found that adipose-derived stem cell (ADSC) exosomes have anti-oxidant and anti-inflammatory characteristics. The current study verified their therapeutic potential to elucidate mechanisms of ADSC exosome actions in ultraviolet B (UVB) light-induced skin injury. Exosomes were isolated from ADSCs and hypoxic pretreated ADSCs. Next-generation sequencing (NGS) was applied to characterize differential mRNA expression. A UV-induced mice skin injury model was generated to investigate therapeutic effects regarding the exosomes via immunofluorescence and ELISA analysis. Regulatory mechanisms were illustrated using luciferase report analysis and in vitro experiments. The results demonstrated that exosomes from hypoxic pretreated ADSCs (HExos) inhibited UVB light-induced vascular injury by reversing reactive oxygen species, inflammatory factor expression and excessive collagen degradation. NGS showed that HExos inhibits UV-induced skin damage via GLRX5 delivery, while GLRX5 downregulation inhibited the therapeutic effect of HExos on UV-induced skin damage. GLRX5 upregulation increased the protective Exo effect on UV-induced skin and EPC damage by inhibiting ferroptosis, inflammatory cytokine expression and excessive collagen degradation. Therefore, the data indicate that HExos attenuate UV light-induced skin injury via GLRX5 delivery and ferroptosis inhibition.

Modeling of solar UV-induced photodamage on the hair follicles in human skin organoids

Solar ultraviolet (sUV) exposure is known to cause skin damage. However, the pathological mechanisms of sUV on hair follicles have not been extensively explored. Here, we established a model of sUV-exposed skin and its appendages using human induced pluripotent stem cell-derived skin organoids with planar morphology containing hair follicles. Our model closely recapitulated several symptoms of photodamage, including skin barrier disruption, extracellular matrix degradation, and inflammatory response. Specifically, sUV induced structural damage and catagenic transition in hair follicles. As a potential therapeutic agent for hair follicles, we applied exosomes isolated from human umbilical cord blood-derived mesenchymal stem cells to sUV-exposed organoids. As a result, exosomes effectively alleviated inflammatory responses by inhibiting NF-κB activation, thereby suppressing structural damage and promoting hair follicle regeneration. Ultimately, our model provided a valuable platform to mimic skin diseases, particularly those involving hair follicles, and to evaluate the efficacy and underlying mechanisms of potential therapeutics.

Dynamic and Label-Free Sensing of Cardiomyocyte Responses to Nanosized Vesicles for Cardiac Oxidative Stress Injury Therapy

Cardiac oxidative stress is a significant phenotype of myocardial infarction disease, a leading cause of global health threat. There is an urgent need to develop innovative therapies. Nanosized extracellular vesicle (nEV)-based therapy shows promise, yet real-time monitoring of cardiomyocyte responses to nEVs remains a challenge. In this study, a dynamic and label-free cardiomyocyte biosensing system using microelectrode arrays (MEAs) was constructed. Cardiomyocytes were cultured on MEA devices for electrophysiological signal detection and treated with nEVs from E. coli, gardenia, HEK293 cells, and mesenchymal stem cells (MSC), respectively. E. coli-nEVs and gardenia-nEVs induced severe paroxysmal fibrillation, revealing distinct biochemical communication compared to MSC-nEVs. Principal component analysis identified variations and correlations between nEV types. MSC-nEVs enhanced recovery without inducing arrhythmias in a H2O2-induced oxidative stress injury model. This study establishes a fundamental platform for assessing biochemical communication between nEVs and cardiomyocytes, offering new avenues for understanding nEVs' functions in the cardiovascular system.

Antioxidant mechanisms of mesenchymal stem cells and their therapeutic potential in vitiligo

Vitiligo is a skin pigmentation disorder caused by melanocyte damage or abnormal function. Reac-tive oxygen species Reactive oxygen species can cause oxidative stress damage to melanocytes, which in turn induces vitiligo. Traditional treatments such as phototherapy, drugs, and other methods of treatment are long and result in frequent recurrences. Currently, mesenchymal stem cells (MSCs) are widely used in the research of various disease treatments due to their excellent paracrine effects, making them a promising immunoregulatory and tissue repair strategy. Furthermore, an increasing body of evi-dence suggests that utilizing the paracrine functions of MSCs can downregulate oxidative stress in the testes, liver, kidneys, and other affected organs in animal models of certain diseases. Addition-ally, MSCs can help create a microenvironment that promotes tissue repair and regeneration in are-as with oxidative stress damage, improving the disordered state of the injured site. In this article, we review the pathogenesis of oxidative stress in vitiligo and promising strategies for its treatment.

Mesenchymal stem cells-derived extracellular vesicles protect against oxidative stress-induced xenogeneic biological root injury via adaptive regulation of the PI3K/Akt/NRF2 pathway

Xenogeneic extracellular matrices (xECM) for cell support have emerged as a potential strategy for addressing the scarcity of donor matrices for allotransplantation. However, the poor survival rate or failure of xECM-based organ transplantation is due to the negative impacts of high-level oxidative stress and inflammation on seed cell viability and stemness. Herein, we constructed xenogeneic bioengineered tooth roots (bio-roots) and used extracellular vesicles from human adipose-derived mesenchymal stem cells (hASC-EVs) to shield bio-roots from oxidative damage. Pretreatment with hASC-EVs reduced cell apoptosis, reactive oxygen species generation, mitochondrial changes, and DNA damage. Furthermore, hASC-EV treatment improved cell proliferation, antioxidant capacity, and odontogenic and osteogenic differentiation, while significantly suppressing oxidative damage by activating the phosphatidylinositol 3-kinase (PI3K)/Akt pathway and nuclear factor erythroid 2 (NFE2)-related factor 2 (NRF2) nuclear translocation via p62-associated Kelch-like ECH-associated protein 1 (KEAP1) degradation. Inhibition of PI3K/Akt and Nrf2 knockdown reduced antioxidant capacity, indicating that the PI3K/Akt/NRF2 pathway partly mediates these effects. In subcutaneous grafting experiments using Sprague-Dawley rats, hASC-EV administration significantly enhanced the antioxidant effect of the bio-root, improved the regeneration efficiency of periodontal ligament-like tissue, and maximized xenograft function. Conclusively, therefore, hASC-EVs have the potential to be used as an immune modulator and antioxidant for treating oxidative stress-induced bio-root resorption and degradation, which may be utilized for the generation and restoration of other intricate tissues and organs.

Extracellular vesicle biopotentiated hydrogels for diabetic wound healing: The art of living nanomaterials combined with soft scaffolds

Diabetic wounds (DWs) pose a major challenge for the public health system owing to their high incidence, complex pathogenesis, and long recovery time; thus, there is an urgent need to develop innovative therapies to accelerate the healing process of diabetic wounds. As natural nanovesicles, extracellular vesicles (EVs) are rich in sources with low immunogenicity and abundant nutritive molecules and exert potent therapeutic effects on diabetic wound healing. To avoid the rapid removal of EVs, a suitable delivery system is required for their controlled release. Owing to the advantages of high porosity, good biocompatibility, and adjustable physical and chemical properties of hydrogels, EV biopotentiated hydrogels can aid in achieving precise and favorable therapy against diabetic wounds. This review highlights the different design strategies, therapeutic effects, and mechanisms of EV biopotentiated hydrogels. We also discussed the future challenges and opportunities of using EV biopotentiated hydrogels for diabetic wound healing.

Chronological aging impacts abundance, function and microRNA content of extracellular vesicles produced by human epidermal keratinocytes

The disturbance of intercellular communication is one of the hallmarks of aging. The goal of this study is to clarify the impact of chronological aging on extracellular vesicles (EVs), a key mode of communication in mammalian tissues. We focused on epidermal keratinocytes, the main cells of the outer protective layer of the skin which is strongly impaired in the skin of elderly. EVs were purified from conditioned medium of primary keratinocytes isolated from infant or aged adult skin. A significant increase of the relative number of EVs released from aged keratinocytes was observed whereas their size distribution was not modified. By small RNA sequencing, we described a specific microRNA (miRNA) signature of aged EVs with an increase abundance of miR-30a, a key regulator of barrier function in human epidermis. EVs from aged keratinocytes were found to be able to reduce the proliferation of young keratinocytes, to impact their organogenesis properties in a reconstructed epidermis model and to slow down the early steps of skin wound healing in mice, three features observed in aged epidermis. This work reveals that intercellular communication mediated by EVs is modulated during aging process in keratinocytes and might be involved in the functional defects observed in aged skin.

Progress in the Development of Stem Cell-Derived Cell-Free Therapies for Skin Aging

Introduction

The skin is a vital organ as the body's largest barrier, but its function declines with aging. Therefore, research into effective regeneration treatments must continue to advance. Stem cell transplantation, a cell-based therapy, has become a popular skin-aging treatment, although it comes with drawbacks like host immune reactions. Stem cell-derived cell-free therapies have emerged as an alternative, backed by promising preclinical findings. Stem cell secretomes and extracellular vesicles (EVs) are the key components in cell-free therapy from stem cells. However, comprehensive reviews on the mechanisms of such treatments for skin aging are still limited.

Purpose

This review discusses stem cell-derived cell-free therapy's potential mechanisms of action related to skin aging prevention by identifying specific molecular targets suitable for the interventions.

Methods

A search identified 27 relevant in vitro studies on stem cell-derived cell-free therapy interventions in skin aging model cells without restricting publication years using PubMed, Scopus, and Google Scholar.

Results

Stem cell-derived cell-free therapy can prevent skin aging through various mechanisms, such as (1) involvement of multiple regenerative pathways [NFkb, AP-1, MAPK, P-AKT, NRF2, SIRT-1]; (2) oxidative stress regulation [by reducing oxidants (HO-1, NQO1) and enhancing antioxidants (SOD1, CAT, GP, FRAP)]; (3) preventing ECM degradation [by increasing elastin, collagen, HA, TIMP, and reducing MMP]; (4) regulating cell activity [by reducing cell senescence (SA-β-gal), apoptosis, and cell cycle arrest (P53, P12, P16); and enhancing autophagy, cell migration, and cell proliferation (Ki67)] (5) Regulating the inflammatory pathway [by reducing IL-6, IL-1, TNF-⍺, and increasing TGF-β]. Several clinical trials have also revealed improvements in wrinkles, elasticity, hydration, pores, and pigmentation.

Conclusion

Stem cell-derived cell-free therapy is a potential novel treatment for skin aging by cell rejuvenation through various molecular mechanisms.

Extracellular vesicles from 3D cultured dermal papilla cells improve wound healing via Krüppel-like factor 4/vascular endothelial growth factor A -driven angiogenesis

Background

Non-healing wounds are an intractable problem of major clinical relevance. Evidence has shown that dermal papilla cells (DPCs) may regulate the wound-healing process by secreting extracellular vesicles (EVs). However, low isolation efficiency and restricted cell viability hinder the applications of DPC-EVs in wound healing. In this study, we aimed to develop novel 3D-DPC spheroids (tdDPCs) based on self-feeder 3D culture and to evaluate the roles of tdDPC-EVs in stimulating angiogenesis and skin wound healing.

Methods

To address the current limitations of DPC-EVs, we previously developed a self-feeder 3D culture method to construct tdDPCs. DPCs and tdDPCs were identified using immunofluorescence staining and flow cytometry. Subsequently, we extracted EVs from the cells and compared the effects of DPC-EVs and tdDPC-EVs on human umbilical vein endothelial cells (HUVECs) in vitro using immunofluorescence staining, a scratch-wound assay and a Transwell assay. We simultaneously established a murine model of full-thickness skin injury and evaluated the effects of DPC-EVs and tdDPC-EVs on wound-healing efficiency in vivo using laser Doppler, as well as hematoxylin and eosin, Masson, CD31 and α-SMA staining. To elucidate the underlying mechanism, we conducted RNA sequencing (RNA-seq) of tdDPC-EV- and phosphate-buffered saline-treated HUVECs. To validate the RNA-seq data, we constructed knockdown and overexpression vectors of Krüppel-like factor 4 (KLF4). Western blotting, a scratch-wound assay, a Transwell assay and a tubule-formation test were performed to detect the protein expression, cell migration and lumen-formation ability of KLF4 and vascular endothelial growth factor A (VEGFA) in HUVECs incubated with tdDPC-EVs after KLF4 knockdown or overexpression. Dual-luciferase reporter gene assays were conducted to verify the activation effect of KLF4 on VEGFA.

Results

We successfully cultured tdDPCs and extracted EVs from DPCs and tdDPCs. The tdDPC-EVs significantly promoted the proliferation, lumen formation and migration of HUVECs. Unlike DPC-EVs, tdDPC-EVs exhibited significant advantages in terms of promoting angiogenesis, accelerating wound healing and enhancing wound-healing efficiency both in vitro and in vivo. Bioinformatics analysis and further functional experiments verified that the tdDPC-EV-regulated KLF4/VEGFA axis is pivotal in accelerating wound healing.

Conclusions

3D cultivation can be utilized as an innovative optimization strategy to effectively develop DPC-derived EVs for the treatment of skin wounds. tdDPC-EVs significantly enhance wound healing via KLF4/VEGFA-driven angiogenesis.

miR-100a-5p-enriched exosomes derived from mesenchymal stem cells enhance the anti-oxidant effect in a Parkinson's disease model via regulation of Nox4/ROS/Nrf2 signaling

BACKGROUND

The pathogenesis of Parkinson's disease (PD) has not been fully elucidated, and there are no effective disease-modifying drugs for the treatment of PD. Mesenchymal stem cells have been used to treat several diseases, but are not readily available.

METHODS

Here, we used phenotypically uniform trophoblast stage-derived mesenchymal stem cells (T-MSCs) from embryonic stem cells, which are capable of stable production, and their exosomes (T-MSCs-Exo) to explore the molecular mechanisms involved in dopaminergic (DA) neuron protection in PD models using experimental assays (e.g., western blotting, immunofluorescence and immunohistochemistry staining).

RESULTS

We assessed the levels of DA neuron injury and oxidative stress in MPTP-induced PD mice and MPP+-induced MN9D cells after treating them with T-MSCs or T-MSCs-Exo. Furthermore, T-MSCs-Exo miRNA sequencing analysis revealed that miR-100-5p-enriched T-MSCs-Exo directly targeted the 3' UTR of NOX4, which could protect against the loss of DA neurons, maintain nigro-striatal system function, ameliorate motor deficits, and reduce oxidative stress via the Nox4-ROS-Nrf2 axis in PD models.

CONCLUSIONS

The study suggests that miR-100-5p-enriched T-MSCs-Exo may be a promising biological agent for the treatment of PD. Schematic summary of the mechanism underlying the neuroprotective actions of T-MSCs-Exo in PD. T-MSCs Exo may inhibit the expression level of the target gene NOX4 by delivering miR-100-5p, thereby reducing ROS production and alleviating oxidative stress via the Nox4-ROS-Nrf2 axis, thus improving DA neuron damage in PD.

MSC-Derived Exosomes Ameliorate Intervertebral Disc Degeneration By Regulating the Keap1/Nrf2 Axis

Bone marrow mesenchymal stem cell derived exosomes (BMSC-exos) are a crucial means of intercellular communication and can regulate a range of biological processes by reducing inflammation, decreasing apoptosis and promoting tissue repair. The process of intervertebral disc degeneration (IVDD) is accompanied by increased reactive oxygen species (ROS) because of a decrease in the expression of Nrf2, a critical transcription factor that resists excessive ROS. Our study demonstrated that BMSC-exos decreased ROS production by inhibiting Keap1 and promoting Nrf2 expression, attenuating the apoptosis, inflammation, and degeneration of nucelus pulposus (NP) cells. BMSC-exos promoted an increase in Nrf2 and nuclear translocation, while NF-κB expression was downregulated during this process. Additionally, the expression of antioxidative proteins was elevated after treatment with BMSC-exos. In vivo, we found more NP tissue retention in the BMSC-exos-treated group, along with more expression of Nrf2 and antioxidant-related proteins. Our findings demonstrated for the first time that BMSC-exos could restore the down-regulated antioxidant response system in degenerating NP cells by modulating the Keap1/Nrf2 axis. BMSC-exos could be used as an immediate ROS modulator in the treatment of intervertebral disc degeneration. When BMSC-exos were uptaken by NPCs, the expression of Keap1 decreased and this led to increased expression of Nrf2. Nuclear translocation of Nrf2 then promoted the synthesis of antioxidants against ROS and inhibited NF-kB signalling. Cellular inflammation, apoptosis, and ECM-related indicators were further reduced. Together, the process of IVDD was alleviated.

The pathological and therapeutically role of mesenchymal stem cell (MSC)-derived exosome in degenerative diseases; Particular focus on LncRNA and microRNA

By releasing exosomes, which create the ideal milieu for the resolution of inflammation, mesenchymal stem cells (MSCs) enhance tissue healing and have strong immunomodulatory capabilities. MSCs-derived exosome also can affect tumor progress by a myriad of mechanisms. Exosomes function as a cell-cell communication tool to affect cellular activity in recipient cells and include an array of efficient bioactive chemicals. Understanding the fundamental biology of inflammation ablation, tissue homeostasis, and the creation of therapeutic strategies is particularly interested in the horizontal transfer of exosomal long non-coding RNAs (lncRNA) and microRNAs (miRNAs) to recipient cells, where they affect target gene expression. Herein, we propose an exosomal lncRNA and microRNA profile in neurological, renal, cardiac, lung, and liver diseases as well as skin wounds and arthritis.

Effect of stem cell secretome in skin rejuvenation: a narrative review

PURPOSE

Cutaneous aging is an inevitable biological process that develops over time due to cumulative cellular and molecular changes caused by exposure to intrinsic (chronological aging) and extrinsic (photo-aging) factors on the skin. Skin aging is characterized by a decline in the body's capability to sustain senescence, dermal cell apoptosis, and homeostasis. Stem cell secretions (secretome) are defined as the total set of dynamically overlapping paracrine soluble growth factors, cytokines, chemokines, angiogenic factors, extracellular matrix proteins, and antimicrobial peptides known to be responsible for tissue rejuvenation, regeneration, homeostasis, and immunomodulation.

METHODS

In this review, we summarized the molecular and regulatory mechanism of the secretome in preventing the skin aging process, as well as its capacity in inducing skin rejuvenation. Furthermore, we illustrated secretome efficiency as an anti-aging therapeutic strategy based on in vitro and in vivo published studies.

RESULTS

In all reviewed publications, the secretome has been proven to be the most effective treatment for aged skin, capable of reversing the aging process through the action of cytokines, growth factors, and collagen, which are its primary components. The reported mechanism of action involves modulating the signaling pathways of aging and replenishing the skin with collagen, fibronectin, and elastin, ultimately resulting in skin renewal and rejuvenation.

CONCLUSION

In conclusion, compared to available treatments, the secretome shows great promise as an anti-aging therapy.

Low-dose lipopolysaccharide inhibits spinal cord injury-induced neuronal apoptosis by regulating autophagy through the lncRNA MALAT1/Nrf2 axis

Background

Spinal cord injury (SCI) is a neurological disease associated with a high disability rate. Low-dose lipopolysaccharide (LPS) has been reported to activate cross-immune tolerance and alleviate the effects of various traumatic stimuli. The present study aimed to explore the effect of LPS on SCI and the potential molecular mechanism.

Methods

Male Sprague-Dawley (SD) rats were used to established an in vivo SCI model and were intraperitoneally injected with lentivirus particles encoding a MALAT1 small interfering RNA (siRNA) on day 10 prior to SCI and with 0.2 mg/kg LPS 72 h prior to SCI. Basso, Beattie, and Bresnahan (BBB) scoring; HE staining; and TUNEL assay were used to assess neurological function and pathophysiological changes. Western blot and immunohistochemistry (IHC) were used to detect cell autophagy and Nrf2 nuclear translocation. PC12 cells were exposed to oxygen-glucose deprivation/reoxygenation (OGD/R) to establish an in vitro SCI model. In vitro SCI model cells were pretreated with LPS and transfected with siMALAT1 or MALAT1 overexpression plasmid aimed at knocking down MALAT1 or overexpressing MALAT1. The cell counting kit-8 (CCK-8) assay was used to measure the toxicity of LPS towards PC12 cells. Flow cytometry and immunofluorescence analysis were performed to investigate cell apoptosis and Nrf2 nuclear translocation.

Results

SCI rats preconditioned with low-dose LPS had higher BBB scores, reduced SCI injury, increased MALAT1 expression and activated autophagy and Nrf2 nuclear translocation in the in vivo SCI model. In the in vitro SCI model, low-dose LPS treatment suppressed the apoptotic ratio of PC12 cells, increased MALAT1 expression, activated autophagy, and promoted Nrf2 nuclear translocation. Silencing MALAT1 exacerbated OGD/R injury in vitro and weakened the protective effect of low-dose LPS. Overexpression of MALAT1 inhibits OGD/R-induced apoptosis by inducing autophagy and promoting Nrf2 nuclear translocation. This was also been confirmed in animal experiments, silencing MALAT1 blocked the promotion of Nrf2 by low-dose LPS and the alleviated of SCI apoptosis.

Conclusions

Low-dose LPS exhibited a protective role on SCI by activating autophagy and suppressing nerve cell apoptosis via the lncRNA MALAT1/Nrf2 axis.

Research progress of extracellular vesicles and exosomes derived from mesenchymal stem cells in the treatment of oxidative stress-related diseases

There is growing evidence that mesenchymal stem cell-derived extracellular vesicles and exosomes can significantly improve the curative effect of oxidative stress-related diseases. Mesenchymal stem cell extracellular vesicles and exosomes (MSC-EVs and MSC-Exos) are rich in bioactive molecules and have many biological regulatory functions. In this review, we describe how MSC-EVs and MSC-Exos reduce the related markers of oxidative stress and inflammation in various systemic diseases, and the molecular mechanism of MSC-EVs and MSC-Exos in treating apoptosis and vascular injury induced by oxidative stress. The results of a large number of experimental studies have shown that both local and systemic administration can effectively inhibit the oxidative stress response in diseases and promote the survival and regeneration of damaged parenchymal cells. The mRNA and miRNAs in MSC-EVs and MSC-Exos are the most important bioactive molecules in disease treatment, which can inhibit the apoptosis, necrosis and oxidative stress of lung, heart, kidney, liver, bone, skin and other cells, and promote their survive and regenerate.

Exosome/metformin-loaded self-healing conductive hydrogel rescues microvascular dysfunction and promotes chronic diabetic wound healing by inhibiting mitochondrial fission

Chronic diabetic wounds remain a globally recognized clinical challenge. They occur due to high concentrations of reactive oxygen species and vascular function disorders. A promising strategy for diabetic wound healing is the delivery of exosomes, comprising bioactive dressings. Metformin activates the vascular endothelial growth factor pathway, thereby improving angiogenesis in hyperglycemic states. However, multifunctional hydrogels loaded with drugs and bioactive substances synergistically promote wound repair has been rarely reported, and the mechanism of their combinatorial effect of exosome and metformin in wound healing remains unclear. Here, we engineered dual-loaded hydrogels possessing tissue adhesive, antioxidant, self-healing and electrical conductivity properties, wherein 4-armed SH-PEG cross-links with Ag⁺, which minimizes damage to the loaded goods and investigated their mechanism of promotion effect for wound repair. Multiwalled carbon nanotubes exhibiting good conductivity were also incorporated into the hydrogels to generate hydrogen bonds with the thiol group, creating a stable three-dimensional structure for exosome and metformin loading. The diabetic wound model of the present study suggests that the PEG/Ag/CNT-M + E hydrogel promotes wound healing by triggering cell proliferation and angiogenesis and relieving peritraumatic inflammation and vascular injury. The mechanism of the dual-loaded hydrogel involves reducing the level of reactive oxygen species by interfering with mitochondrial fission, thereby protecting F-actin homeostasis and alleviating microvascular dysfunction. Hence, we propose a drug-bioactive substance combination therapy and provide a potential mechanism for developing vascular function-associated strategies for treating chronic diabetic wounds.

Mesenchymal stem cell-derived exosomes attenuate DNA damage response induced by cisplatin and bleomycin

Stem cell-derived exosomes (SC-Exos) have been shown to protect cells from chemical-induced deoxyribonucleic acid (DNA) damage. However, there has been no systematic comparison of the efficacy of exosomes against different types of DNA damage. Therefore, in this study, we assessed the protective effect of exosomes derived from human embryonic stem cell-induced mesenchymal stem cells (hESC-MSC-Exos) on two types of DNA damage, namely, intra-/inter-strand crosslinks and DNA double-strand breaks induced by cisplatin (Pt) and bleomycin (BLM), respectively, in HeLa cells. The alkaline comet assay demonstrated that hESC-MSC-Exos effectively inhibited Pt- and BLM-induced DNA damage in a dose-dependent manner. When the concentration of hESC-MSC-Exos reaches 2.0 × 10⁶ and 4.0 × 10⁶ particles/mL in Pt- and BLM-treated groups, respectively, there was a significant decrease in tail DNA percentage (Pt: 20.80 ± 1.61 vs 9.40 ± 1.14, p < 0.01; BLM: 21.80 ± 1.31 vs 6.70 ± 0.60, p < 0.01), tail moment (Pt: 10.00 ± 1.21 vs 2.08 ± 0.51, p < 0.01; BLM: 12.00 ± 0.81 vs 2.00 ± 0.21, p < 0.01), and olive tail moment (Pt: 6.01 ± 0.55 vs 2.09 ± 0.25, p < 0.01; BLM: 6.03 ± 0.37 vs 1.53 ± 0.13, p < 0.01). Phospho-histone H2AX (γH2AX) immunofluorescence and western blotting showed an over 50 % decrease in γH2AX expression when the cells were pretreated with hESC-MSC-Exos. As reactive oxygen species (ROS) are important mediators of Pt- and BLM-induced DNA damage, dichloro-dihydro-fluorescein diacetate staining indicated that hESC-MSC-Exos inhibited the increase in intracellular ROS in drug-treated cells. In conclusion, our findings suggest that hESC-MSC-Exos can protect cells from the two types of DNA-damaging drugs and that reduced intracellular ROS is involved in this effect.

Therapeutic Applications of Plant-Derived Extracellular Vesicles as Antioxidants for Oxidative Stress-Related Diseases

Extracellular vesicles (EVs) composed of a lipid bilayer are released from various cell types, including animals, plants, and microorganisms, and serve as important mediators of cell-to-cell communication. EVs can perform a variety of biological functions through the delivery of bioactive molecules, such as nucleic acids, lipids, and proteins, and can also be utilized as carriers for drug delivery. However, the low productivity and high cost of mammalian-derived EVs (MDEVs) are major barriers to their practical clinical application where large-scale production is essential. Recently, there has been growing interest in plant-derived EVs (PDEVs) that can produce large amounts of electricity at a low cost. In particular, PDEVs contain plant-derived bioactive molecules such as antioxidants, which are used as therapeutic agents to treat various diseases. In this review, we discuss the composition and characteristics of PDEVs and the appropriate methods for their isolation. We also discuss the potential use of PDEVs containing various plant-derived antioxidants as replacements for conventional antioxidants.