Project description:Transplantation of neural stem cells (NSCs) has been proved to promote functional rehabilitation of brain lesions including ischemic stroke. However, the therapeutic effects of NSC transplantation is limited by the low survival and differentiation rates of NSCs due to the harsh environment in the brain after ischemic stroke. Here, we employed NSCs derived from human induced pluripotent stem cells (iPSCs) together with exosomes extracted from NSCs to treat cerebral ischemia induced by middle cerebral artery occlusion/reperfusion (MCAO/R) in mice. The results showed that NSC-derived exosomes significantly reduced the inflammatory response, alleviated oxidative stress after NSC transplantation, and facilitated NSCs differentiation in vivo. The combination of NSCs with exosomes ameliorated the injury of brain tissue including cerebral infarct, neuronal death and glial scarring, and promoted the motor function recovery. To explore the underlying mechanisms, we analyzed the miRNA profiles of NSC-derived exosomes and the potential downstream genes. Our study provided the rationale for the clinical application of NSC-derived exosomes as a supportive adjuvant for NSC transplantation after stroke.
Project description:Transplantation of neural stem cells (NSCs) has been proved to promote functional rehabilitation of brain lesions including ischemic stroke. However, the therapeutic effects of NSC transplantation are limited by the low survival and differentiation rates of NSCs due to the harsh environment in the brain after ischemic stroke. Here, we employed NSCs derived from human induced pluripotent stem cells together with exosomes extracted from NSCs to treat cerebral ischemia induced by middle cerebral artery occlusion/reperfusion in mice. The results showed that NSC-derived exosomes significantly reduced the inflammatory response, alleviated oxidative stress after NSC transplantation, and facilitated NSCs differentiation in vivo. The combination of NSCs with exosomes ameliorated the injury of brain tissue including cerebral infarction, neuronal death, and glial scarring, and promoted the recovery of motor function. To explore the underlying mechanisms, we analyzed the miRNA profiles of NSC-derived exosomes and the potential downstream genes. Our study provided the rationale for the clinical application of NSC-derived exosomes as a supportive adjuvant for NSC transplantation after stroke.
Project description:Acid sphingomyelinase (ASM) inhibitors, which are clinically used as anti-depressants for ~60 years, have recently been shown to enhance stroke recovery in rodents. Using mice and cerebral microvascular endothelial cells exposed to ischemia/reperfusion (I/R) we show that the antidepressants amitriptyline, fluoxetine and desipramine induce angiogenesis in an ASM-dependent way by releasing small extracellular vesicles (sEVs) from endothelial cells, which have bona fide characteristics of exosomes and which, similar to sEVs released during I/R, promote angiogenesis. Post-I/R, ASM inhibition elicits a profound brain remodeling response with increased blood-brain barrier integrity, reduced brain leukocyte infiltrates and increased neuronal survival. The ASM inhibitor-mediated release of sEVs has disclosed an elegant target, via which stroke recovery can be amplified. Key words: Antidepressant, ceramide, exosome, focal cerebral ischemia, middle cerebral artery occlusion, sphingomyelin, stroke recovery
Project description:Aims: Mesenchymal stem cells (MSCs) gradually become attractive candidates for cardiac inflammation modulation, yet understanding of the mechanism remains elusive. Strikingly, recent studies indicated that exosomes secreted by MSCs might be a novel mechanism for the beneficial effect of MSCs transplantation after myocardial infarction. We therefore explored the role of MSC-derived exosomes (MSC-Exo) in the immunomodulation of macrophages after myocardial ischemia-reperfusion and its implications in cardiac injury repair. Methods and Results: Exosomes were isolated from the supernatant of MSCs using a gradient centrifugation method. Administration of MSC-Exo through intramyocardial injection after myocardial ischemia reperfusion reduced infarct size and alleviated inflammation level in heart and serum. Systemic depletion of macrophages with clodronate liposomes abolished the curative effects of MSC-Exo. MSC-Exo modified the polarization of M1 macrophages to M2 macrophages both in vivo and in vitro. miRNA-sequencing of MSC-Exo and bioinformatics analysis implicated miR-182 as a potent candidate mediator of macrophage polarization and TLR4 as a downstream target. Diminishing miR-182 in MSC-Exo partially attenuated its modulation of macrophage polarization. Likewise, knock down of TLR4 also conferred cardioprotective efficacy and reduced inflammation level in a mouse model of myocardial ischemia/reperfusion. Conclusion: Our data indicates that MSC-Exo attenuates myocardial ischemia/reperfusion injury via shuttling miR-182 that modifies the polarization state of macrophages. This study sheds new light on the application of MSC-Exo a potential therapeutic tool for myocardial ischemia/reperfusion injury.
Project description:Stroke places a huge burden on society today, and great of studies were devoted for seeking safe and effective therapeutic strategy to improve the prognosis of stroke. Plasma exosome has exhibited its therapeutic potential against ischemia and reperfusion injury via ameliorating inflammation. To enhance therapeutic potential in patients with ischemic injury, we isolated exosomes from melatonin pretreated rat plasma and assessed the neurological protective effect in a rat model of focal cerebral ischemia. Treatment with melatonin enhanced plasma exosome therapeutic effect against ischemia induced inflammatory response and inflammasome mediated pyroptosis. In addition, we confirmed ischemic stroke induced pyroptotic cell death mainly occurred in microglia, while administration of melatonin treated exosome further effectively decreased infract volume and improved function recovery via regulation of TLR-4/NF-κB signaling pathway. Finally, the altered miRNAs profile in melatonin treated plasma exosomes demonstrated the regulatory mechanisms. This study suggests plasma exosome with melatonin pretreatment might be a more effective strategy for patients with ischemic brain injury. Further exploration of key molecules in plasma exosome may devote more therapeutic value for cerebral ischemic injury.
Project description:Background and Purpose: Long noncoding RNAs (lncRNAs) are an emerging class of genomic regulatory molecules reported in neurodevelopment and many diseases. Despite extensive studies have identified lncRNAs and discovered their functions in CNS diseases, the function of lncRNAs in ischemia stroke remains poorly understood. Method: Ischemia was induced by transient middle cerebral artery occlusion. Expression profiles of lncRNAs, miRNAs and mRNAs after ischemia stroke were obtained using high throughput sequencing technology. A correlation network was constructed to predict lncRNA functions. LncRNA-miRNA-mRNA network was constructed to discover ceRNAs. Results: 1924 novel lncRNAs were identified, indicating that the ischemia stroke has a complex effect on lncRNAs. The top 10 regulated lncRNAs was validated by qRT-PCR. We have also predicted function of lncRNAs, and subjected them to gene co-expression network analysis, revealing the involvement of lncRNAs in many important biological process including injury and repair that are implicated in the regulation of ischemia stroke. Furthermore, lncRNAs mediated SMD (Staufen1-mediated mRNA decay) was analyzed and ceRNA (competitive endogenous RNAs) network was constructed in ischemia stroke. Conclusions: This study reports the genome-wide lncRNA profiles in ischemia stroke using high throughput sequencing and constructs a systematic lncRNA-miRNA-mRNA network which reveals a complex functional noncoding RNA regulatory network in ischemia stroke.
Project description:Using renal ischemia-reperfusion injury as a model of acute kidney injury, we deteremined temporally-released miRNAs released in urinary exosomes during the injury