Exosomes of Human Umbilical Cord MSCs Protect Against Hypoxia/Reoxygenation-Induced Pyroptosis of Cardiomyocytes via the miRNA-100-5p/FOXO3/NLRP3 Pathway

Preconditioning with β-hydroxybutyrate attenuates lung ischemia-reperfusion injury by suppressing alveolar macrophage pyroptosis through the SIRT1-FOXO3 signaling pathway

The complex pathogenesis of lung ischemia-reperfusion injury (LIRI) was examined in a murine model, focusing on the role of pyroptosis and its exacerbation of lung injury. We specifically examined the levels and cellular localization of pyroptosis within the lung, which revealed alveolar macrophages as the primary site. The inhibition of pyroptosis by VX-765 reduced the severity of lung injury, underscoring its significant role in LIRI. Furthermore, the therapeutic potential of β-hydroxybutyrate (β-OHB) in ameliorating LIRI was examined. Modulation of β-OHB levels was evaluated by ketone ester supplementation and 3-hydroxybutyrate dehydrogenase 1 (BDH-1) gene knockout, along with the manipulation of the SIRT1-FOXO3 signaling pathway using EX-527 and pCMV-SIRT1 plasmid transfection. This revealed that β-OHB exerts lung-protective and anti-pyroptotic effects, which were mediated through the upregulation of SIRT1 and the enhancement of FOXO3 deacetylation, leading to decreased pyroptosis markers and lung injury. In addition, β-OHB treatment of MH-S cells in vitro showed a concentration-dependent improvement in pyroptosis, linking its therapeutic benefits to specific cell mechanisms. Overall, this study highlights the significance of alveolar macrophage pyroptosis in the exacerbation of LIRI and indicates the potential of β-OHB in mitigating injury by modulating the SIRT1-FOXO3 signaling pathway.

Dental pulp mesenchymal stem cell-derived exosomes inhibit neuroinflammation and microglial pyroptosis in subarachnoid hemorrhage via the miRNA-197-3p/FOXO3 axis

BACKGROUND

Subarachnoid hemorrhage (SAH) is a severe stroke subtype that lacks effective treatment. Exosomes derived from human dental pulp stem cells (DPSCs) are a promising acellular therapeutic strategy for neurological diseases. However, the therapeutic effects of DPSC-derived exosomes (DPSC-Exos) on SAH remain unknown. In this study, we investigated the therapeutic effects and mechanisms of action of DPSC-Exos in SAH.

MATERIALS AND METHODS

SAH was established using 120 male Sprague-Dawley rats. One hour after SAH induction, DPSC-Exos were administered via tail vein injection. To investigate the effect of DPSC-Exos, SAH grading, short-term and long-term neurobehavioral assessments, brain water content, western blot (WB), immunofluorescence staining, Nissl staining, and HE staining were performed. The role of miR-197-3p/FOXO3 in regulating pyroptosis was demonstrated through miRNA sequencing, bioinformatics analysis, and rescue experiments. The SAH model in vitro was established by stimulating BV2 cells with hemoglobin (Hb) and the underlying mechanism of DPSC-Exos was investigated through WB and Hoechst/PI staining.

RESULTS

The expressions of pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α) were increased after SAH. DPSC-Exos alleviated brain edema and neuroinflammation by inhibiting the expression of FOXO3 and reducing NLRP3 inflammasome activation, leading to improved neurobehavioral functions at 24 h after SAH. In vitro, the expression of the NLRP3 inflammasome components (NLRP3 and caspase1-p20), GSDMD-N, and IL-18 was inhibited in BV2 cells pretreated with DPSC-Exos. Importantly, DPSC-Exos overexpressing miR-197-3p had a more obvious protective effect than those from NC-transfected DPSCs, while those from DPSCs transfected with the miR-197-3p inhibitor had a weaker protective effect. Functional studies indicated that miR-197-3p bound to the 3'-untranslated region of FOXO3, inhibiting its transcription. Furthermore, the overexpression of FOXO3 reversed the protective effects of miR-197-3p.

CONCLUSIONS

DPSC-Exos inhibited activation of the NLRP3 inflammasome and related cytokine release via the miR-197-3p/FOXO3 pathway, alleviated neuroinflammation, and inhibited microglial pyroptosis. These findings suggest that using DPSC-Exos is a promising therapeutic strategy for SAH.

The antidepressant effect of Shexiang Baoxin Pills on myocardial infarction rats with depression may be achieved through the inhibition of the NLRP3 inflammasome pathway

BACKGROUND

Patients with myocardial infarction (MI) frequently experience a heightened incidence of depression, thereby increasing the risk of adverse cardiovascular events. Consequently, early detection and intervention in depressive symptoms among patients with MI are imperative. Shexiang Baoxin Pills (SBP), a Chinese patent medicine employed for the treatment of MI, exhibits diverse mechanisms targeting this condition. Nevertheless, its therapeutic efficacy on postmyocardial infarction depressive symptoms remains unclear. The aim of this study is to investigate the effectiveness and mechanism of SBP in managing depression during acute myocardial infarction (AMI).

METHODS

A rat model combining MI and depression was established, and the rats were randomly divided into four groups: the model (MOD) group, SBP group, Fluoxetine (FLX) group, and Sham group. After 28 days of drug intervention, cardiac function was assessed using echocardiography while behavior was evaluated through sucrose preference test (SPT), forced swimming test (FST), and open-field test (OFT). Additionally, levels of inflammatory factors in serum and hippocampus were measured along with NLRP3 inflammasome-related protein expression via Western blotting and immunofluorescence.

RESULTS

SBP can enhance cardiac function in rats with AMI and depression, while significantly ameliorating depressive-like behavior. Compared to the Sham group, levels of IL-1β, IL-18, TNF-α, and other inflammatory factors were markedly elevated in the MOD group. However, expressions of these inflammatory factors were reduced to varying degrees following treatment with SBP or FLX. Analysis of NLRP3 inflammasome-related proteins in the hippocampus revealed a significant upregulation of IL-1β, IL-18, NLRP3, ASC, caspase-1, and GSDMD in the MOD group; conversely, these measures were significantly attenuated after SBP intervention.

CONCLUSION

We have observed a significant amelioration in depression-like behavior upon SBP administration during the treatment of AMI, suggesting that this effect may be attributed to the inhibition of NLRP3-mediated pyroptosis. (The main findings are summarized in the graphical abstract in the supplementary file.).

Emerging role of mesenchymal stem cell-derived exosome microRNA in radiation injury

PURPOSE

Radiation injury (RI) is a common occurrence in malignant tumors patients receiving radiation therapy. While killing tumor cells, normal tissue surrounding the target area is inevitably irradiated at a certain dose, which can cause varying results of radiation injury. Currently, there are limited clinical treatments available for radiation injuries. In recent years, the negative effects of stem cell therapy have been reported more clearly and non-cellular therapies such as exosomes have become a focus of attention for researchers. As a type of vesicle-like substances secreted by mesenchymal stem cells (MSC), MSC derived exosomes (MSC-exo) carry DNA, mRNA, microRNA (miRNAs), specific proteins, lipids, and other active substances involved in intercellular information exchange. miRNAs released by MSC-exo are capable of alleviating and repairing damaged tissues through anti-apoptosis, modulating immune response, regulating inflammatory response and promoting angiogenesis, which indicates that MSC-exo miRNAs have great potential for application in the prevention and treatment of radiation injury. Therefore, it is necessary to explore the underlying therapeutic mechanisms of MSC-exo miRNAs in this process, which may shed new lights on the treatment of radiation injury.

CONCLUSIONS

Increasing evidence confirms that MSC-exo has shown encouraging applications in tissue repair due to the anti-apoptotic, immunoreactive, and pro-angiogenesis effects of the miRNAs it carries as intercellular communication carriers. However, miRNA-based therapeutics are still in their infancy and many practical issues remain to be addressed for clinical applications.

Emerging role of exosomes in ulcerative colitis: Targeting NOD-like receptor family pyrin domain containing 3 inflammasome

Ulcerative colitis (UC) is a chronic recurrent inflammatory bowel disease. Despite ongoing advances in our understanding of UC, its pathogenesis is yet unelucidated, underscoring the urgent need for novel treatment strategies for patients with UC. Exosomes are nanoscale membrane particles that mediate intercellular communication by carrying various bioactive molecules, such as proteins, RNAs, DNA, and metabolites. The NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome is a cytosolic tripartite protein complex whose activation induces the maturation and secretion of proinflammatory cytokines interleukin-1β (IL-1β) and IL-18, triggering the inflammatory response to a pathogenic agent or injury. Growing evidence suggests that exosomes are new modulators of the NLRP3 inflammasome, with vital roles in the pathological process of UC. Here, recent evidence is reviewed on the role of exosomes and NLRP3 inflammasome in UC. First, the dual role of exosomes on NLRP3 inflammasome and the effect of NLRP3 inflammasome on exosome secretion are summarized. Finally, an outlook on the directions of exosome-NLRP3 inflammasome crosstalk research in the context of UC is proposed and areas of further research on this topic are highlighted.

Unraveling the Signaling Dynamics of Small Extracellular Vesicles in Cardiac Diseases

Effective intercellular communication is essential for cellular and tissue balance maintenance and response to challenges. Cellular communication methods involve direct cell contact or the release of biological molecules to cover short and long distances. However, a recent discovery in this communication network is the involvement of extracellular vesicles that host biological contents such as proteins, nucleic acids, and lipids, influencing neighboring cells. These extracellular vesicles are found in body fluids; thus, they are considered as potential disease biomarkers. Cardiovascular diseases are significant contributors to global morbidity and mortality, encompassing conditions such as ischemic heart disease, cardiomyopathies, electrical heart diseases, and heart failure. Recent studies reveal the release of extracellular vesicles by cardiovascular cells, influencing normal cardiac function and structure. However, under pathological conditions, extracellular vesicles composition changes, contributing to the development of cardiovascular diseases. Investigating the loading of molecular cargo in these extracellular vesicles is essential for understanding their role in disease development. This review consolidates the latest insights into the role of extracellular vesicles in diagnosis and prognosis of cardiovascular diseases, exploring the potential applications of extracellular vesicles in personalized therapies, shedding light on the evolving landscape of cardiovascular medicine.

Mechanisms and therapeutic strategies of extracellular vesicles in cardiovascular diseases

Cardiovascular disease (CVD) significantly impacts global society since it is the leading cause of death and disability worldwide, and extracellular vesicle (EV)-based therapies have been extensively investigated. EV delivery is involved in mediating the progression of CVDs and has great potential to be biomarker and therapeutic molecular carrier. Besides, EVs from stem cells and cardiac cells can effectively protect the heart from various pathologic conditions, and then serve as an alternative treatment for CVDs. Moreover, the research of using EVs as delivery carriers of therapeutic molecules, membrane engineering modification of EVs, or combining EVs with biomaterials further improves the application potential of EVs in clinical treatment. However, currently there are only a few articles summarizing the application of EVs in CVDs. This review provides an overview of the role of EVs in the pathogenesis and diagnosis of CVDs. It also focuses on how EVs promote the repair of myocardial injury and therapeutic methods of CVDs. In conclusion, it is of great significance to review the research on the application of EVs in the treatment of CVDs, which lays a foundation for further exploration of the role of EVs, and clarifies the prospect of EVs in the treatment of myocardial injury.

Mechanisms and Optimization Strategies of Paracrine Exosomes from Mesenchymal Stem Cells in Ischemic Heart Disease

The morbidity and mortality of myocardial infarction (MI) are increasing worldwide. Mesenchymal stem cells (MSCs) are multipotent stem cells with self-renewal and differentiation capabilities that are essential in tissue healing and regenerative medicine. However, the low implantation and survival rates of transplanted cells hinder the widespread clinical use of stem cells. Exosomes are naturally occurring nanovesicles that are secreted by cells and promote the repair of cardiac function by transporting noncoding RNA and protein. In recent years, MSC-derived exosomes have been promising cell-free treatment tools for improving cardiac function and reversing cardiac remodeling. This review describes the biological properties and therapeutic potential of exosomes and summarizes some engineering approaches for exosomes optimization to enhance the targeting and therapeutic efficacy of exosomes in MI.

Advances in the study of exosomes derived from mesenchymal stem cells and cardiac cells for the treatment of myocardial infarction

Acute myocardial infarction has long been the leading cause of death in coronary heart disease, which is characterized by irreversible cardiomyocyte death and restricted blood supply. Conventional reperfusion therapy can further aggravate myocardial injury. Stem cell therapy, especially with mesenchymal stem cells (MSCs), has emerged as a promising approach to promote cardiac repair and improve cardiac function. MSCs may induce these effects by secreting exosomes containing therapeutically active RNA, proteins and lipids. Notably, normal cardiac function depends on intracardiac paracrine signaling via exosomes, and exosomes secreted by cardiac cells can partially reflect changes in the heart during disease, so analyzing these vesicles may provide valuable insights into the pathology of myocardial infarction as well as guide the development of new treatments. The present review examines how exosomes produced by MSCs and cardiac cells may influence injury after myocardial infarction and serve as therapies against such injury. Video Abstract.

The Role of Small Extracellular Vesicles Derived from Mesenchymal Stromal Cells on Myocardial Protection: a Review of Current Advances and Future Perspectives

Small extracellular vesicles (SEVs) secreted by mesenchymal stromal cells (MSCs) are considered one of the most promising biological therapies in recent years. The protective effect of MSCs-derived SEVs on myocardium is mainly related to their ability to deliver cargo, anti-inflammatory properties, promotion of angiogenesis, immunoregulation, and other factors. Herein, this review focuses on the biological properties, isolation methods, and functions of SEVs. Then, the roles and potential mechanisms of SEVs and engineered SEVs in myocardial protection are summarized. Finally, the current situation of clinical research on SEVs, the difficulties encountered, and the future fore-ground of SEVs are discussed. In conclusion, although there are some technical difficulties and conceptual contradictions in the research of SEVs, the unique biological functions of SEVs provide a new direction for the development of regenerative medicine. Further exploration is warranted to establish a solid experimental and theoretical basis for future clinical application of SEVs.

miRNA-Guided Regulation of Mesenchymal Stem Cells Derived from the Umbilical Cord: Paving the Way for Stem-Cell Based Regeneration and Therapy

The human body is an abundant source of multipotent cells primed with unique properties that can be exploited in a multitude of applications and interventions. Mesenchymal stem cells (MSCs) represent a heterogenous population of undifferentiated cells programmed to self-renew and, depending on their origin, differentiate into distinct lineages. Alongside their proven ability to transmigrate toward inflammation sites, the secretion of various factors that participate in tissue regeneration and their immunoregulatory function render MSCs attractive candidates for use in the cytotherapy of a wide spectrum of diseases and conditions, as well as in different aspects of regenerative medicine. In particular, MSCs that can be found in fetal, perinatal, or neonatal tissues possess additional capabilities, including predominant proliferation potential, increased responsiveness to environmental stimuli, and hypoimmunogenicity. Since microRNA (miRNA)-guided gene regulation governs multiple cellular functions, miRNAs are increasingly being studied in the context of driving the differentiation process of MSCs. In the present review, we explore the mechanisms of miRNA-directed differentiation of MSCs, with a special focus on umbilical cord-derived mesenchymal stem cells (UCMSCs), and we identify the most relevant miRNAs and miRNA sets and signatures. Overall, we discuss the potent exploitations of miRNA-driven multi-lineage differentiation and regulation of UCMSCs in regenerative and therapeutic protocols against a range of diseases and/or injuries that will achieve a meaningful clinical impact through maximizing treatment success rates, while lacking severe adverse events.

Inflammation in myocardial infarction: roles of mesenchymal stem cells and their secretome

Inflammation plays crucial roles in the regulation of pathophysiological processes involved in injury, repair and remodeling of the infarcted heart; hence, it has become a promising target to improve the prognosis of myocardial infarction (MI). Mesenchymal stem cells (MSCs) serve as an effective and innovative treatment option for cardiac repair owing to their paracrine effects and immunomodulatory functions. In fact, transplanted MSCs have been shown to accumulate at injury sites of heart, exerting multiple effects including immunomodulation, regulating macrophages polarization, modulating the activation of T cells, NK cells and dendritic cells and alleviating pyroptosis of non-immune cells. Many studies also proved that preconditioning of MSCs can enhance their inflammation-regulatory effects. In this review, we provide an overview on the current understanding of the mechanisms on MSCs and their secretome regulating inflammation and immune cells after myocardial infarction and shed light on the applications of MSCs in the treatment of cardiac infarction.

Mesenchymal stem cells protect against TBI-induced pyroptosis in vivo and in vitro through TSG-6

Background

Pyroptosis, especially microglial pyroptosis, may play an important role in central nervous system pathologies, including traumatic brain injury (TBI). Transplantation of mesenchymal stem cells (MSCs), such as human umbilical cord MSCs (hUMSCs), has been a focus of brain injury treatment. Recently, MSCs have been found to play a role in many diseases by regulating the pyroptosis pathway. However, the effect of MSC transplantation on pyroptosis following TBI remains unknown. Tumor necrosis factor α stimulated gene 6/protein (TSG-6), a potent anti-inflammatory factor expressed in many cell types including MSCs, plays an anti-inflammatory role in many diseases; however, the effect of TSG-6 secreted by MSCs on pyroptosis remains unclear.

Methods

Mice were subjected to controlled cortical impact injury in vivo. To assess the time course of pyroptosis after TBI, brains of TBI mice were collected at different time points. To study the effect of TSG-6 secreted by hUMSCs in regulating pyroptosis, normal hUMSCs, sh-TSG-6 hUMSCs, or different concentrations of rmTSG-6 were injected intracerebroventricularly into mice 4 h after TBI. Neurological deficits, double immunofluorescence staining, presence of inflammatory factors, cell apoptosis, and pyroptosis were assessed. In vitro, we investigated the anti-pyroptosis effects of hUMSCs and TSG-6 in a lipopolysaccharide/ATP-induced BV2 microglial pyroptosis model.

Results

In TBI mice, the co-localization of Iba-1 (marking microglia/macrophages) with NLRP3/Caspase-1 p20/GSDMD was distinctly observed at 48 h. In vivo, hUMSC transplantation or treatment with rmTSG-6 in TBI mice significantly improved neurological deficits, reduced inflammatory cytokine expression, and inhibited both NLRP3/Caspase-1 p20/GSDMD expression and microglial pyroptosis in the cerebral cortices of TBI mice. However, the therapeutic effect of hUMSCs on TBI mice was reduced by the inhibition of TSG-6 expression in hUMSCs. In vitro, lipopolysaccharide/ATP-induced BV2 microglial pyroptosis was inhibited by co-culture with hUMSCs or with rmTSG-6. However, the inhibitory effect of hUMSCs on BV2 microglial pyroptosis was significantly reduced by TSG-6-shRNA transfection.

Conclusion

In TBI mice, microglial pyroptosis was observed. Both in vivo and in vitro, hUMSCs inhibited pyroptosis, particularly microglial pyroptosis, by regulating the NLRP3/Caspase-1/GSDMD signaling pathway via TSG-6.

Non-coding RNAs in necroptosis, pyroptosis, and ferroptosis in cardiovascular diseases

Accumulating evidence has proved that non-coding RNAs (ncRNAs) play a critical role in the genetic programming and gene regulation of cardiovascular diseases (CVDs). Cardiovascular disease morbidity and mortality are rising and have become a primary public health issue that requires immediate resolution through effective intervention. Numerous studies have revealed that new types of cell death, such as pyroptosis, necroptosis, and ferroptosis, play critical cellular roles in CVD progression. It is worth noting that ncRNAs are critical novel regulators of cardiovascular risk factors and cell functions by mediating pyroptosis, necroptosis, and ferroptosis. Thus, ncRNAs can be regarded as promising therapeutic targets for treating and diagnosing cardiovascular diseases. Recently, there has been a surge of interest in the mediation of ncRNAs on three types of cell death in regulating tissue homeostasis and pathophysiological conditions in CVDs. Although our understanding of ncRNAs remains in its infancy, the studies reviewed here may provide important new insights into how ncRNAs interact with CVDs. This review summarizes what is known about the functions of ncRNAs in modulating cell death-associated CVDs and their role in CVDs, as well as their current limitations and future prospects.

miR-15b-5p REGULATES THE NLRP3 INFLAMMASOME SIGNAL THROUGH TARGETING SIRT3 TO REGULATE HYPOXIA/REOXYGENATION-INDUCED CARDIOMYOCYTE PYROPTOSIS PROCESS

ABSTRACT

Hypoxia/reoxygenation (H/R) induces pyroptosis in the setting of acute myocardial infarction (AMI). Previous studies have shown that the expression of the miR-15 family is stimulated in myocardial ischemia-reperfusion injury or H/R-induced cardiomyocyte injury, and miR-15 is a promoter of cardiac ischemia-reperfusion or H/R injury. However, whether miR-15b-5p regulates H/R injury and cardiomyocyte pyroptosis and its mechanism still need to be further clarified. Bioinformatics analysis elicited that SIRT3 was the downstream regulatory target gene of miR-15b-5p. SIRT3 has been shown to participate in the regulation of pyroptosis by negatively regulating the NLRP3 inflammasome pathway. Therefore, we hypothesized that miR-15b-5p targets SIRT3 and activated the NLRP3 inflammasome pathway to promote H/R-induced cardiomyocyte pyroptosis. We first show that H/R increases miR-15b-5p in rat cardiomyocytes H9C2. Next, we tested the effects of inhibition of miR-15b-5p or overexpression of SIRT3. We found that miR-15b-5p downregulation or SIRT3 overexpression could reverse the H/R-induced pyroptosis. Furthermore, silencing SIRT3 antagonized the protective effect of miR-15b-5p downregulation on H9C2 cells. NLRP3 inhibitor MCC950 annulled the previously mentioned antagonistic effect of silencing SIRT3 on the protection of miR-15b-5p downregulation against pyroptosis. We then used a rat AMI model to analyze myocardial infarction area by triphenyl tetrazolium chloride staining and assess serum cardiac troponin T level by ELISA and found that miR-15b-5p silencing reduced AMI injury in rats. Collectively, these results suggest that miR-15b-5p increase H/R-induced pyroptosis in cardiomyocytes by targeting SIRT3 and activating the NLRP3 inflammasome.

MSC-Derived Small Extracellular Vesicles Attenuate Autoimmune Dacryoadenitis by Promoting M2 Macrophage Polarization and Inducing Tregs via miR-100-5p

Background

Mesenchymal stem cell-derived small extracellular vesicles (MSC-sEVs) have been increasingly proved as promising immunomodulators against some autoimmune disorders. However, the possible effect and the underlying mechanism of MSC-sEVs in autoimmune dry eye have been rarely studied.

Methods

Small extracellular vesicles from human umbilical cord mesenchymal stem cells (hUC-MSC-sEVs) were subconjunctivally injected to rabbit dry eye model, and their preventive or therapeutical effects were assessed by recording the clinical and histological scores. Quantitative real-time PCR (Q-PCR), western blot and flow cytometry were performed to evaluate the immunomodulatory effects of hUC-MSC-sEVs on macrophages and T regulatory cells (Tregs) both in vivo and in vitro, and the in vitro T cell proliferation was detected by Bromodeoxyuridine (BrdU) assay. In addition, high expression of miR-100-5p in hUC-MSC-sEVs was identified by Q-PCR, and the functional role of sEVs-miR-100-5p on macrophages was explored by a series of co-culture experiments using sEVs derived from hUC-MSCs transfected with miR-100-5p inhibitor.

Results

We firstly demonstrated that hUC-MSC-sEVs had the preventive and therapeutical effects on rabbit autoimmune dacryoadenitis, an animal model of Sjögren’s syndrome (SS) dry eye. Further investigation revealed that hUC-MSC-sEVs administration effectively elicited macrophages into an anti-inflammatory M2 phenotype and elevated the proportion of Tregs both in vivo and in vitro, which contributed to reduced inflammation and improved tissue damage. Importantly, hUC-MSC-sEVs-educated macrophages with M2-like phenotype exhibited strong capacity to inhibit CD4+ T cell proliferation and promote Treg generation in vitro. Mechanistically, miR-100-5p was highly enriched in hUC-MSC-sEVs, and knockdown of miR-100-5p in hUC-MSC-sEVs partially blunted the promotion of hUC-MSC-sEVs on M2 macrophage polarization and even attenuated the effect of hUC-MSC-sEVs-educated macrophages on T cell suppression and Treg expansion.

Conclusion

Our data indicated that hUC-MSC-sEVs alleviated autoimmune dacryoadenitis by promoting M2 macrophage polarization and Treg generation possibly through shuttling miR-100-5p. This study sheds new light on the application of MSC-sEVs as a promising therapeutic method for SS dry eye.

The potential role of circulating exosomes in protecting myocardial injury in acute myocardial infarction via regulating miR-190a-3p/CXCR4/CXCL12 pathway

Exosomes of different origins have been found to be protective against ischemic-induced myocardial injury. This study examined the protective effects of circulating exosomes in the mice model of acute myocardial infarction (AMI) and explored the underlying molecular mechanisms. The effects of exosomes on myocardial injury were assessed in the AMI mice model. The in vivo studies showed that circulating exosomes reduced the infarcted size, improved the morphology of heart tissues and also reduced apoptosis of the heart tissues. In addition, the model mice showed an increase in the CD34 + /VEGFR2 + cell population and CD31, CXCR4 and CXCL12 expression after exosomes treatment. MiR-190a-3p was significantly down-regulated in the exosomes derived from the culture medium of hypoxia-treated human cardiomyocytes (HCMs). Further analysis revealed that miR-190a-3p could physically interact with CXCR4/CXCL12 by targeting the respective 3'UTRs. These exosomes could up-regulated CXCR4 and CXCL12 expression in the EPCs; in addition, miR-190a-3p mimics repressed CXCR4/CXCL12 expression in EPCs, while its inhibitor had opposite effects. The in vitro functional assays showed that miR-190a-3p overexpression suppressed the cell viability, proliferation, migration, adhesion and tube formation of EPCs; while miR-190a-3p inhibitor had the opposite effects; exosomes derived from the culture medium of hypoxia-treated HCMs exhibited similar actions of miR-190a-3p inhibitor. Moreover, miR-190a-3p was down-regulated in exosomes from serum in the AMI group when compared to that from sham group. Treatment with exosomes from serum in the AMI group promoted cell proliferation, migration, adhesion and tube formation of EPCs when compared to that in the sham group. More importantly, IT1t attenuated the enhanced effects of miR-190a-3p inhibition on EPC proliferation, migration, adhesion and tube formation. In conclusion, circulating exosomes exerted protective effects on myocardial injury in the AMI mice model, and down-regulation of miR-190a-3p in the circulating exosomes may exert protective effects against myocardial injury. Hypoxia induced the downregulation of miR-190a-3p in the culture medium of HCMs, and the mechanistic investigations indicated that exosomes of hypoxia-conditioned HCM culture medium promoted the cell viability, proliferation, migration, adhesion and tube formation of EPCs via regulating miR-190a-3p/CXCR4/CXCL12 pathway.

Mesenchymal Stem Cell-Derived Nanovesicles as a Credible Agent for Therapy of Pulmonary Hypertension

Extracellular vesicles (EVs) derived from mesenchymal stem cells (MSCs) have been evaluated in many studies as promising therapeutic agents for pulmonary hypertension (PH). However, low yields and heterogeneity are a major barrier in the translational utility of EVs for clinical studies. To address these limitations, we fabricated MSCs derived nanovesicles (MSC-NVs) by serial extrusion through filters resulting in MSC-NVs with characteristics similar to conventional EVs but with much higher production yields. Herein, we examined the therapeutic efficacy of MSC-NVs in preclinical models of PH in vitro and in vivo. Intervention with MSC-NVs improved the core pathologies of monocrotaline (MCT) induced PH in rat. Intravenous administration of MSC-NVs resulted in significant uptake within hypertensive lungs, pulmonary artery lesions and especially in pulmonary artery smooth muscle cells (PASMCs). In vitro, MSC-NVs inhibited PDGF-induced proliferation, migration, and phenotype switch of PASMCs. miRNA sequencing analysis of the genetic cargo of MSC-NVs revealed that miR-125b-5p and miR-100-5p are highly abundant, suggesting they might account for the therapeutic effects of MSC-NVs in PH. Depletion of miR-125b-5p and miR-100-5p in MSCs almost completely abolished the beneficial effects of MSC-NVs in protecting PASMCs from PDGF stimulated changes in vitro, and also diminished the protective effects of MSC-NVs in MCT induced PH in vivo. These data highlight the efficacy and advantages of MSC-NVs over MSC-EVs as a promising therapeutic strategy against PH.

Human Retinal Progenitor Cells Derived Small Extracellular Vesicles Delay Retinal Degeneration: A Paradigm for Cell-free Therapy

Retinal degeneration is a leading cause of irreversible vision impairment and blindness worldwide. Previous studies indicate that subretinal injection of human retinal progenitor cells (hRPCs) can delay the progression of retinal degeneration, preserve retinal function, and protect photoreceptor cells from death, albeit the mechanism is not well understood. In this study, small extracellular vesicles derived from hRPCs (hRPC-sEVs) were injected into the subretinal space of retinal dystrophic RCS rats. We find that hRPC-sEVs significantly preserve the function of retina and thickness of the outer nuclear layer (ONL), reduce the apoptosis of photoreceptors in the ONL, and suppress the inflammatory response in the retina of RCS rats. In vitro, we have shown that hRPC-sEV treatment could significantly reserve the low-glucose preconditioned apoptosis of photoreceptors and reduce the expression of pro-inflammatory cytokines in microglia. Pathway analysis predicted the target genes of hRPC-sEV microRNAs involved in inflammation related biological processes and significantly enriched in processes autophagy, signal release, regulation of neuron death, and cell cycle. Collectively, our study suggests that hRPC-sEVs might be a favorable agent to delay retinal degeneration and highlights as a new paradigm for cell-free therapy.

Mesenchymal Stem Cells Alleviate Post-resuscitation Cardiac and Cerebral Injuries by Inhibiting Cell Pyroptosis and Ferroptosis in a Swine Model of Cardiac Arrest

Following cardiopulmonary resuscitation (CPR), the ensuing cardiac and cerebral injuries contribute to the poor outcome of cardiac arrest (CA) victims, in which the pathogenetic process is possibly driven by cell pyroptosis and ferroptosis. Mesenchymal stem cells (MSCs) have been shown to be a promising strategy for post-resuscitation cardiac and cerebral protection in rat, but its effectiveness in the clinically relevant swine model and the potential protective mechanism remain unknown. The present study was designed to investigate whether MSCs administration could alleviate post-resuscitation cardiac and cerebral injuries through the inhibition of cell pyroptosis and ferroptosis in swine. Twenty-four male domestic swine were randomly divided into three groups: sham, CPR, and MSC. A dose of 2.5×106/kg of MSCs derived from human embryonic stem cells was intravenously infused at 1.5, and 3 days prior to CA. The animal model was established by 8 min of CA and then 8 min of CPR. After resuscitation, cardiac, cerebral function and injury biomarkers were regularly evaluated for a total of 24 h. At 24 h post-resuscitation, pyroptosis-related proteins (NLRP3, ASC, cleaved caspase-1, GSDMD), proinflammatory cytokines (IL-1β, IL-18), ferroptosis-related proteins (ACSL4, GPX4) and iron deposition in the heart, cortex and hippocampus were measured. Consequently, significantly greater cardiac, cerebral dysfunction and injuries after resuscitation were observed in the CPR and MSC groups compared with the sham group. However, the severity of cardiac and cerebral damage were significantly milder in the MSC group than in the CPR group. In addition, the expression levels of NLRP3, ASC, cleaved caspase-1, GSDMD and ACSL4, the contents of IL-1β and IL-18, and the level of iron deposition were significantly higher while the expression level of GPX4 was significantly lower in the heart, cortex and hippocampus in all resuscitated animals compared with the sham group. Nevertheless, MSCs administration significantly decreased post-resuscitation cardiac, cerebral pyroptosis and ferroptosis compared to the CPR group. Our results showed that the administration of MSCs significantly alleviated post-resuscitation cardiac and cerebral injuries in swine, in which the protective effects were related to the inhibition of cell pyroptosis and ferroptosis.

Identification and bioinformatics analysis of differentially expressed milk exosomal microRNAs in milk exosomes of heat-stressed Holstein cows

In summer, heat stress is one of the primary reasons for the compromised health and low milk productivity of dairy cows. Hyperthermia affects milk synthesis and secretion in the mammary glands of dairy cows. As molecules for intercellular communication, milk-derived exosomes carry genetic material, proteins, and lipids, playing a crucial role in mammary tissue growth and milk synthesis in dairy cows. The aim of this study was to explore the milk exosomal miRNA profile of heat-stressed and normal Holstein cows. We isolated and identified milk exosomes to screening for differentially expressed miRNAs using small RNA sequencing. Then, TargetScan and miRanda algorithms were used to predict the putative targets of the differentially expressed miRNAs, whereas GO and KEGG pathway enrichment analyses were performed for the differentially expressed miRNA-target genes. Our results showed that 215 miRNAs were significantly differentially expressed in heat-stressed milk exosomes, of which one was upregulated and 214 were significantly downregulated. GO and KEGG enrichment analyses indicated that differentially expressed miRNAs might play a role in apoptosis, autophagy, and the p38 MAPK pathway. qRT-PCR assay verified that the expression of miRNAs was consistent with the sequencing results, warranting further verification of their specific targets of action. In conclusion, changes in the miRNA expression profile of milk exosomes indicated the role of exosomal miRNAs in regulating heat stress resistance and apoptosis in dairy cows. Our results suggested that milk-derived exosomal miRNAs could increase mammary gland resistance to heat stress, thereby enhancing milk synthesis in dairy cows.

Knockdown of hsa_circ_0000729 Inhibits the Tumorigenesis of Non-Small Cell Lung Cancer Through Mediation of miR-1281/FOXO3 Axis

Background

Non-small cell lung cancer (NSCLC) is a subtype of lung cancer which seriously threatens the health of people. Circular RNAs (CircRNAs) are endogenous RNAs which have stable closed structure; they are known to be involved in tumorigenesis of NSCLC. Meanwhile, hsa_circ_0000729 was reported to be upregulated in NSCLC. Nevertheless, the function of hsa_circ_0000729 in NSCLC remains unclear.

Methods

Western blot and RT-qPCR were performed to investigate protein and mRNA levels, respectively. CCK-8 assay was performed to test the cell viability and cell death was investigated by flow cytometry. NSCLC cell pyroptosis was observed by electron microscope. In addition, the migration and invasion of NSCLC cells were detected by wound healing and transwell assay. The relation among hsa_circ_0000729, miR-1281 and FOXO3 was explored by dual luciferase reporter assay and RNA pull-down.

Results

Hsa_circ_0000729 was found to be upregulated in NSCLC cells, and hsa_circ_0000729 knockdown obviously suppressed the proliferation of NSCLC cells through inducing pyroptosis. In addition, silencing of hsa_circ_0000729 notably inhibited the invasion and migration of NSCLC cells. Meanwhile, hsa_circ_0000729 could bind with miR-1281, and FOXO3 was directly targeted by miR-1281. Moreover, the anti-tumor effect of hsa_circ_0000729 siRNAs on NSCLC was markedly reversed by miR-1281 antagomir. Furthermore, silencing of hsa_circ_0000729 inhibited the tumor growth of NSCLC in vivo.

Conclusion

Knockdown of hsa_circ_0000729 inhibits the tumorigenesis of NSCLC through mediation of miR-1281/FOXO3 axis. Thus, hsa_circ_0000729 might be served as a crucial mediator in NSCLC.

Human Umbilical Cord Mesenchymal Stem Cell-Derived Exosomes Attenuate Oxygen-Glucose Deprivation/Reperfusion-Induced Microglial Pyroptosis by Promoting FOXO3a-Dependent Mitophagy

Background

Mesenchymal stem cell-derived exosomes (MSC-exos) have been recognized as a promising therapeutic strategy for neonatal hypoxic-ischemic brain damage (HIBD). Recently, microglial pyroptosis was shown to play a vital role in the progression of neonatal HIBD. However, whether MSC-exos improve HIBD by regulating microglial pyroptosis remains unknown.

Methods

Exosomes were isolated from human umbilical cord mesenchymal stem cells (huMSCs) and identified by transmission electron microscopy (TEM), western blot, and nanoparticle tracking analysis (NTA). BV-2 cells were subjected to oxygen-glucose deprivation/reoxygenation (OGD/R) to induce microglial ischemia/reperfusion (I/R) in vitro. CCK-8, ELISA, western blot, and Hoechst 33342/PI double staining were performed to detect the pyroptosis of BV-2 cells. Conditioned medium (CM) from BV-2 cells exposed to different treatments was used to investigate its effect on neuronal injury. Moreover, 3-methyladenine (3-MA) and mitochondrial division inhibitor-1 (mdi-1) were used to verify the involvement of mitophagy in the protection of MSC-exos against OGD/R-induced pyroptosis in BV-2 cells. Finally, FOXO3a siRNA was used to investigate the involvement of FOXO3a in MSC-exo-induced mitophagy and pyroptosis inhibition.

Results

Exosomes from huMSCs were successfully extracted. In OGD/R-exposed BV-2 cells, MSC-exos increased cell viability and decreased the expression of NLRP3, cleaved caspase-1, and GSDMD-N as well as the release of IL-1β and IL-18. Compared with CM from OGD/R-exposed BV-2 cells treated with PBS, CM from OGD/R-exposed BV-2 cells treated with MSC-exos significantly increased the viability of SH-SY5Y cells and decreased LDH release. MSC-exos also increased the expression of TOM20 and COX IV in OGD/R-exposed BV-2 cells. Additionally, 3-MA and mdi-1 attenuated the inhibition of pyroptosis with MSC-exo treatment. Furthermore, FOXO3a siRNA partially abolished the neuroprotective effect of MSC-exos and attenuated mitophagy and pyroptosis inhibition induced by MSC-exo treatment.

Conclusions

Our findings demonstrated that MSC-exos increased FOXO3a expression to enhance mitophagy, therefore protecting microglia from I/R-induced pyroptosis and alleviating subsequent neuronal injury.

BMSC-Derived Exosomes Ameliorate Osteoarthritis by Inhibiting Pyroptosis of Cartilage via Delivering miR-326 Targeting HDAC3 and STAT1//NF-κB p65 to Chondrocytes

Background

In the past decade, mesenchymal stem cells (MSCs) have been widely used for the treatment of osteoarthritis (OA), and noncoding RNAs in exosomes may play a major role.

Aim

The present study is aimed at exploring the effect and mechanism of miR-326 in exosomes secreted by bone marrow mesenchymal stem cells (BMSCs) on pyroptosis of cartilage and OA improvement.

Methods

Exosomes from BMSCs (BMSC-Exos) were isolated and identified to incubate with OA chondrocytes. Proliferation, migration, specific gene and miR-326 expression, and pyroptosis of chondrocytes were detected. BMSCs or chondrocytes were transfected with miR-326 mimics or inhibitors to investigate the effect of miR-326 in BMSC-Exos on pyroptosis of chondrocytes and the potential mechanism. Finally, a rat OA model was established to verify the effect and mechanism of miR-326 in BMSC-Exos on cartilage of pyroptosis.

Results

Incubation with BMSC-Exos could significantly improve the survival rate, migration ability, and chondrocyte-specific genes (COL2A1, SOX9, Agg, and Prg4) and miR-326 expression of OA chondrocytes and significantly inhibit pyroptosis of chondrocytes by downregulation of the levels of inflammatory cytokines, Caspase-1 activity, and pyroptosis-related proteins such as GSDMD, NLRP3, ASC, IL-1β, and IL-18 (P < 0.01). PKH26 labeling confirmed the uptake of BMSC-Exos by chondrocytes. Incubation with exosomes extracted from BMSCs overexpressing miR-326 can significantly repress the pyroptosis of chondrocytes, while knockdown of miR-326 had the opposite effect (P < 0.01). The same result was also demonstrated by direct interference with the expression level of miR-326 in chondrocytes (P < 0.01). In addition, we found that the overexpression of miR-326 significantly inhibited the expression of HDAC3 and NF-κB p65 and significantly promoted the expression of STAT1, acetylated STAT1, and acetylated NF-κB p65 in chondrocytes (P < 0.01). The targeted relationship between miR-326 and HDAC3 was verified by dual-luciferase reporter assay. Animal experiments confirmed the mechanism by which miR-326 delivered by BMSC-Exos inhibits pyroptosis of cartilage by targeting HDAC3 and STAT1/NF-κB p65 signaling pathway.

Conclusion

BMSC-Exos can deliver miR-326 to chondrocytes and cartilage and improve OA by targeting HDAC3 and STAT1//NF-κB p65 to inhibit pyroptosis of chondrocytes and cartilage. Our findings provide a new mechanism for BMSC-Exos to treat OA.

LncRNA MIAT promotes hypoxia-induced H9C2 cell pyroptosis via binding to SF1 to inhibit CGRP transcription

NEW FINDINGS

What is the central question of this study? How does long non-coding RNA myocardial infarction-associated transcript (lncRNA MIAT) function in hypoxia-induced H9C2 cells? What is the main finding and its importance? LncRNA MIAT inhibited transcription of calcitonin gene-related peptide by binding to splicing factor 1, thereby promoting hypoxia-induced H9C2 cell pyroptosis. This study provides a new theoretical basis for the treatment of acute myocardial infarction by using lncRNA MIAT as a molecular target to mediate cardiomyocyte pyrodeath.

ABSTRACT

Hypoxia induces severe cardiomyocyte pyroptosis, contributing to acute myocardial infarction. The aim of this study was to analyse the molecular mechanism of long non-coding RNA myocardial infarction-associated transcript (lncRNA MIAT) in hypoxia-induced H9C2 cell pyroptosis. A hypoxic H9C2 cell model was established. Cell viability was detected via the Cell Counting Kit-8 method. Levels of lactate dehydrogenase, malondialdehyde and superoxide dismutase and expressions of pyroptotic markers, lncRNA MIAT, splicing factor 1 (SF1) and calcitonin gene-related peptide (CGRP) were detected via qRT-PCR. The subcellular localization of lncRNA MIAT was predicted and confirmed via LncATLAS and nuclear/cytosol fractionation assay. The binding relationships between lncRNA MIAT and SF1 and between SF1 and the CGRP promotor were verified via RNA immunoprecipitation. Rescue experiments were designed to confirm the role of lncRNA MIAT/SF1/CGRP in H9C2 cell pyroptosis. LncRNA MIAT was overexpressed in hypoxia-induced H9C2 cells. Hypoxia induced pyroptosis in H9C2 cells. Silencing of lncRNA MIAT enhanced cell viability and alleviated pyroptosis. LncRNA MIAT inhibited CGRP transcription via binding to SF1. Overexpression of SF1 promoted CGRP transcription and relieved H9C2 cell pyroptosis. Downregulation of CGRP reversed the role of silencing lncRNA MIAT in H9C2 cell pyroptosis. Overall, lncRNA MIAT inhibited CGRP transcription via binding to SF1, thereby promoting hypoxia-induced H9C2 cell pyroptosis.

LncRNA ORLNC1 Promotes Bone Marrow Mesenchyml Stem Cell Pyroptosis Induced by Advanced Glycation End Production by Targeting miR-200b-3p/Foxo3 Pathway

Bone marrow mesenchymal stem cells (BMSCs) are a type of adult stem cells that originate from the mesoderm and have important roles in the body because of their self-renewal and multidirectional differentiation potential. Now it has been proved that BMSCs are closely related to the development of osteoporosis (OP). There is growing evidence that lncRNAs are involved in regulating the pyroptosis of BMSCs. And advanced glycation end-products (AGEs) have been recognized as NOD-like receptor family pyrin domain-containing protein 3 (NLRP3) inflammasome activators. In this study, we aimed to explore the role of lncRNA ORLNC1 (NONMMUT016106.2) on the pyroptosis of BMSCs under CML (Nε-(carboxymethyl) lysine, the most common AGEs) treatment and its specific molecular mechanisms. Our study revealed that CML treatment promoted pyroptosis of BMSCs and upregulated ORLNC1 expression. As a competing endogenous RNA (ceRNA) of miR-200b-3p, the level of ORLNC1 was negatively correlated with miR-200b-3p. Foxo3 was a target of miR-200b-3p and ORLNC1 promoted BMSCs pyroptosis induced by CML through targeting miR-200b-3p/Foxo3 pathway.

Regulation of pyroptosis in cardiovascular pathologies: Role of noncoding RNAs

Cardiovascular disease (CVD) is one of the most important diseases endangering human life. The pathogenesis of CVDs is complex. Pyroptosis, which differs from traditional apoptosis and necrosis, is characterized by cell swelling until membrane rupture, resulting in the release of cell contents and activation of a strong inflammatory response. Recent studies have revealed that inflammation and pyroptosis play important roles in the progression of CVDs. Noncoding RNAs (ncRNAs) are considered promising biomarkers and potential therapeutic targets for the diagnosis and treatment of various diseases, including CVDs. Growing evidence has revealed that ncRNAs can mediate the transcriptional or posttranscriptional regulation of pyroptosis-related genes by participating in the pyroptosis regulatory network. The role and molecular mechanism of pyroptosis-regulating ncRNAs in cardiovascular pathologies are attracting increasing attention. Here, we summarize research progress on pyroptosis and the role of ncRNAs, particularly microRNAs (miRNAs), long ncRNAs (lncRNAs), and circular RNAs (circRNAs), in the regulation of pyroptosis in CVD pathologies. Identifying these disease-related ncRNAs is important for understanding the pathogenesis of CVDs and providing new targets and ideas for their prevention and treatment.

Stem Cell-Derived Exosomes Potential Therapeutic Roles in Cardiovascular Diseases

Owing to myocardial abnormalities, cardiac ailments are considered to be the major cause of morbidity and mortality worldwide. According to a recent study, membranous vesicles that are produced naturally, termed as "exosomes", have emerged as the potential candidate in the field of cardiac regenerative medicine. A wide spectrum of stem cells has also been investigated in the treatment of cardiovascular diseases (CVD). Exosomes obtained from the stem cells are found to be cardioprotective and offer great hope in the treatment of CVD. The basic nature of exosomes is to deal with the intracellular delivery of both proteins and nucleic acids. This activity of exosomes helps us to rely on them as the attractive pharmaceutical delivery agents. Most importantly, exosomes derived from microRNAs (miRNAs) hold great promise in assessing the risk of CVD, as they serve as notable biomarkers of the disease. Exosomes are small, less immunogenic, and lack toxicity. These nanovesicles harbor immense potential as a therapeutic entity and would provide fruitful benefits if consequential research were focused on their upbringing and development as a useful diagnostic and therapeutic tool in the field of medicine.

hucMSC-derived exosomes attenuate colitis by regulating macrophage pyroptosis via the miR-378a-5p/NLRP3 axis

Background

Human umbilical cord mesenchymal stem cell (hucMSC)-derived exosomes are recognized as novel cell-free therapeutic agents for inflammatory bowel disease (IBD), a condition caused by dysregulated intestinal mucosal immunity. In this event, macrophage pyroptosis, a process of cell death following the activation of NLRP3 (NOD-like receptor family, pyrin domain-containing 3) inflammasomes, is believed to partially account for inflammatory reactions. However, the role of macrophage pyroptosis in the process of hucMSC-derived exosomes alleviating colitis remains unknown. This study aimed at exploring the therapeutic effect and mechanism of hucMSC-derived exosomes on colitis repair.

Methods

In vivo, we used BALB/c mice to establish a dextran sulfate sodium (DSS)-induced colitis model and administrated hucMSC-derived exosomes intravenously to estimate its curative effect. Human myeloid leukemia mononuclear (THP-1) cells and mouse peritoneal macrophages (MPMs) were stimulated with lipopolysaccharides (LPS) and Nigericin to activate NLRP3 inflammasomes, which simulated an inflammation environment in vitro. A microRNA mimic was used to verify the role of miR-378a-5p/NLRP3 axis in the colitis repair.

Results

hucMSC-derived exosomes inhibited the activation of NLRP3 inflammasomes in the mouse colon. The secretion of interleukin (IL)-18, IL-1β, and Caspase-1 cleavage was suppressed, resulting in reduced cell pyroptosis. The same outcome was observed in the in vitro cell experiments, where the co-culture of THP-1 cells and MPMs with hucMSC-derived exosomes caused decreased expression of NLRP3 inflammasomes and increased cell survival. Furthermore, miR-378a-5p was highly expressed in hucMSC-derived exosomes and played a vital function in colitis repair.

Conclusion

hucMSC-derived exosomes carrying miR-378a-5p inhibited NLRP3 inflammasomes and abrogated cell pyroptosis to protect against DSS-induced colitis.