外泌体及其工程化应用于缺血性脑卒中的研究进展

缺血性脑卒中是一种致残率和死亡率极高的脑血管疾病。目前，尚无有效的治疗方法能够促进缺血性脑卒中后的神经功能恢复。外泌体既可以介导细胞之间的通信，又具有跨越血脑屏障的能力，故在缺血性脑卒中的治疗中受到广泛关注。利用生物工程技术修饰改造外泌体，制备具有脑靶向性和治疗作用的工程化外泌体，应用于缺血性脑卒中的研究与治疗，以期提高脑卒中后神经功能的修复，减少临床致残率和死亡率，提高患者的生存和生活质量。本文从外泌体、外泌体在缺血性脑卒中的作用、工程化外泌体的制备等方面进行综述，并讨论工程化外泌体在治疗缺血性脑卒中的应用前景，以期为后续研究提供参考。     

外泌体在缺血性卒中诊断及治疗中的研究与应用

缺血性卒中是最常见的脑卒中类型,可导致严重的神经功能障碍,但目前缺乏有效的诊断方法和治疗手段。外泌体是一种天然的囊泡,可以通过递送蛋白质、脂质、核酸发挥细胞间通讯的作用。缺血性卒中发生后,外泌体分泌量增加且内容物发生变化,因此可以作为潜在的生物标志物,用以辅助缺血性卒中的诊断和治疗。本文旨在综述外泌体在缺血性卒中中潜在的诊断价值,并探讨外泌体在卒中后的修复作用以及作为药物载体的应用前景,最后我们简要介绍了基于外泌体的临床研究现状。     

神经源性外泌体在精神疾病中作用的研究进展

外泌体是一类内吞起源的细胞外囊泡，其携带源细胞的mRNA、非编码RNA、蛋白质、脂质、DNA和其他生物活性物质，并在许多生理过程中发挥作用。在大脑中，外泌体参与突触可塑性、神经元应激反应、细胞间通信和神经发生等过程。外泌体可以穿过血-脑脊液屏障，且含量随其分泌和受体细胞的不同而变化，可以作为神经功能障碍的生物标志物。中枢神经系统的细胞间通讯在大脑生长、发育和内稳态的维持方面发挥重要作用，研究神经源性外泌体可以为疾病诊断和治疗干预提供信息。本文综述神经源性外泌体在中枢神经系统中的作用以及在精神障碍的病理生理学机制。     

外泌体在脑胶质瘤诊治中的研究进展

正外泌体是细胞(尤其是肿瘤细胞)分泌到细胞外的小囊泡,其内包含信号传递的受体、生物活性脂质、核酸及蛋白质等。外泌体参与肿瘤进展的多个方面。体液外泌体(包括蛋白质、核酸等)可以作为肿瘤生物标志物。本文就外泌体在脑胶质瘤诊治中的研究进展进行综述。     

CSF外泌体在CNS疾病诊断与应用价值的研究进展

外泌体是由细胞内多囊泡体与细胞膜融合释放到胞外的囊泡。外泌体由多种细胞分泌,存在于多种体液中。外泌体中含有蛋白质、脂质和核酸,可参与细胞间的信息交流。CNS细胞分泌的外泌体参与了CNS疾病发生发展过程。研究表明,外泌体不仅可以作为CNS疾病的早期诊断标志物,对CNS疾病也具有治疗潜能。本文着重阐述了CSF中外泌体在CNS疾病发生发展及诊治中的研究进展。     

外泌体介导神经免疫与多发性硬化

目的外泌体颗粒内部和表面均携带活性膜蛋白、脂质和遗传物质,这些物质可进行信息传递,参与多种生物信号通路,如免疫应答、炎性反应等过程。研究结果显示,外泌体在多发性硬化(MS)等多种自身免疫性疾病中含量明显增加,可作为潜在的信息载体参与MS的生理病理过程,但其具体作用及机制尚不清楚。外泌体信号在细胞与细胞间的传导加深了人们对MS发生、发展的认识,同时为MS和其他神经免疫性疾病的治疗和干预提供了新的策略。本文主要就外泌体在免疫细胞和神经细胞之间炎性反应诱导和炎性反应扩散的作用进行综述,并就外泌体对MS发生和发展的影响以及其在MS诊断和治疗中的作用做一介绍。     

外泌体在心境障碍中诊断及治疗的研究进展

外泌体作为一种纳米级别的细胞外囊泡，内含多种生物活性物质，其广泛参与细胞间物质运输与信息传递，并在多种病理生理过程中发挥重要作用。心境障碍常因其临床复杂性而导致识别困难、诊断不明确以及治疗难度大。心境障碍患者的外泌体在数量及表型上与健康对照者相比存在差异。现对心境障碍患者外泌体的相关研究进行综述，探讨不同来源的外泌体作为心境障碍生物诊断标志物以及治疗靶点的可能性。     

外泌体在癫痫炎症反应中的作用

癫痫是一种突发性大脑神经元高度同步化反复异常过度放电引起短暂性脑功能失调的慢性大脑疾病,中枢神经系统内特定区域的炎症反应是癫痫的共同特征之一。研究发现,外泌体可通过抑制胶质细胞激活、调节免疫应答等方式减轻炎症反应,并依赖其脂质双层结构和能够穿越血-脑屏障的优势,可作为给药载体应用于癫痫的治疗。现就外泌体在癫痫炎症反应过程中作用的研究进展进行综述,以期寻求诊断与治疗癫痫的潜在方案。     

外泌体在常见精神障碍发病中的研究进展

近年研究显示, 精神障碍的发病机制涉及正常细胞间通信、突触可塑性、神经炎症、表观遗传和神经再生等过程。外泌体是由各类细胞释放的纳米级膜性囊泡, 其中包含蛋白质、脂质、核酸, 尤其是微小核糖核酸等多种组分参与胞间物质交换和信息交流, 在多种病理生理过程中起重要作用, 并可能参与了精神疾病的发病过程。此外, 外泌体及其产物还可能作为基因及药物的有效载体参与诊疗过程。本文中综述了外泌体在常见精神障碍中的可能作用机制, 为未来进一步研究外泌体作为可能的精神障碍早期诊断标志物及药物载体的精准化应用提供参考。     

外泌体在阿尔茨海默病中的研究进展

外泌体是一种纳米级细胞外囊泡,大多数细胞类型均可分泌,存在于血液、唾液、脑脊液和乳汁等体液中.阿尔茨海默病(AD)是一种起病隐匿的进行性发展的神经系统退行性疾病,给家庭和社会带来沉重的负担,其病因迄今未明.因外泌体可携带相应来源细胞的核酸、蛋白质等分子信息,所以在多种疾病诊治中有着强大的生物学功能.随着研究的深入,外泌体在AD中的作用成为近年来研究的热点,但也存在争议.研究发现,外泌体在AD中有多种作用:一方面,它可在细胞间传播毒性β淀粉样蛋白(β-amyloid,Aβ)和过度磷酸化tau蛋白(P-tau),并可能会诱导细胞凋亡从而造成神经元的丢失;另一方面,外泌体似乎能通过被胶质细胞摄取而减少大脑Aβ负荷.本文将简要介绍外泌体,并阐述其在AD中的研究进展.     

Systemic administration of exosomes released from mesenchymal stromal cells promote functional recovery and neurovascular plasticity after stroke in rats

Here, for the first time, we test a novel hypothesis that systemic treatment of stroke with exosomes derived from multipotent mesenchymal stromal cells (MSCs) promote neurovascular remodeling and functional recovery after stroke in rats. Adult male Wistar rats were subjected to 2 hours of middle cerebral artery occlusion (MCAo) followed by tail vein injection of 100 μg protein from MSC exosome precipitates or an equal volume of vehicle phosphate-buffered saline (PBS) (n=6/group) 24 hours later. Animals were killed at 28 days after stroke and histopathology and immunohistochemistry were employed to identify neurite remodeling, neurogenesis, and angiogenesis. Systemic administration of MSC-generated exosomes significantly improved functional recovery in stroke rats compared with PBS-treated controls. Axonal density and synaptophysin-positive areas were significantly increased along the ischemic boundary zone of the cortex and striatum in MCAo rats treated with exosomes compared with PBS control. Exosome treatment significantly increased the number of newly formed doublecortin (a marker of neuroblasts) and von Willebrand factor (a marker of endothelial cells) cells. Our results suggest that intravenous administration of cell-free MSC-generated exosomes post stroke improves functional recovery and enhances neurite remodeling, neurogenesis, and angiogenesis and represents a novel treatment for stroke.     

Exosomes from miRNA‐126‐modified endothelial progenitor cells alleviate brain injury and promote functional recovery after stroke

AimsWe previously showed that the protective effects of endothelial progenitor cells (EPCs)‐released exosomes (EPC‐EXs) on endothelium in diabetes. However, whether EPC‐EXs are protective in diabetic ischemic stroke is unknown. Here, we investigated the effects of EPC‐EXs on diabetic stroke mice and tested whether miR‐126 enriched EPC‐EXs (EPC‐EXs^miR126) have enhanced efficacy.MethodsThe db/db mice subjected to ischemic stroke were intravenously administrated with EPC‐EXs 2 hours after ischemic stroke. The infarct volume, cerebral microvascular density (MVD), cerebral blood flow (CBF), neurological function, angiogenesis and neurogenesis, and levels of cleaved caspase‐3, miR‐126, and VEGFR2 were measured on day 2 and 14.ResultsWe found that (a) injected EPC‐EXs merged with brain endothelial cells, neurons, astrocytes, and microglia in the peri‐infarct area; (b) EPC‐EXs^miR126 were more effective than EPC‐EXs in decreasing infarct size and increasing CBF and MVD, and in promoting angiogenesis and neurogenesis as well as neurological functional recovery; (c) These effects were accompanied with downregulated cleaved caspase‐3 on day 2 and vascular endothelial growth factor receptor 2 (VEGFR2) upregulation till day 14.ConclusionOur results indicate that enrichment of miR126 enhanced the therapeutic efficacy of EPC‐EXs on diabetic ischemic stroke by attenuating acute injury and promoting neurological function recovery.     

干细胞疗法治疗缺血性卒中的研究进展

目前缺血性卒中所致神经损伤修复的传统治疗方法尚无突破,而以干细胞为基础的新型治疗策略正成为研究热点。大量动物实验和部分临床实验已经证实,无论是机体自身干、祖细胞的动员、募集,还是自体或异体干细胞移植,都显著改善了受损的神经功能。目前已证实局部植入、静脉注入、或全身动员的干细胞在基质细胞衍生因子-1/基质细胞衍生因子-1受体4（Stromal cell-derived Factor-1/CXC Chemokine Receptor-4,SDF-1/CXCR4）趋化分子和β2-整联蛋白等因子的作用下归巢至脑缺血区域;提供富含营养因子的微环境,保护坏死灶周围缺血半暗带组织;增强血管发生和血管生成;促进卒中后内源性干、祖细胞的迁移、存活和分化;并逐渐分化为神经细胞替代丢失的神经元。这几重因素可能共同参与了结构重建和功能修复。     

Potential effects of mesenchymal stem cell derived extracellular vesicles and exosomal miRNAs in neurological disorders

Mesenchymal stem cells are multipotent cells that possess anti-inflammatory, antiapoptotic and immunomodulatory properties. The effects of existing drugs for neurodegenerative disorders such as Alzheimer's disease are limited, thus mesenchymal stem cell therapy has been anticipated as a means of ameliorating neuronal dysfunction. Since mesenchymal stem cells are known to scarcely differentiate into neuronal cells in damaged brain after transplantation, paracrine factors secreted from mesenchymal stem cells have been suggested to exert therapeutic effects. Extracellular vesicles and exosomes are small vesicles released from mesenchymal stem cells that contain various molecules, including proteins, mRNAs and microRNAs. In recent years, administration of exosomes/extracellular vesicles in models of neurological disorders has been shown to improve neuronal dysfunctions, via exosomal transfer into damaged cells. In addition, various microRNAs derived from mesenchymal stem cells that regulate various genes and reduce neuropathological changes in various neurological disorders have been identified. This review summarizes the effects of exosomes/extracellular vesicles and exosomal microRNAs derived from mesenchymal stem cells on models of stroke, subarachnoid and intracerebral hemorrhage, traumatic brain injury, and cognitive impairments, including Alzheimer's disease.     

Neural differentiation of human Wharton's jelly-derived mesenchymal stem cells improves the recovery of neurological function after transplantation in ischemic stroke rats

Human Wharton’s jelly-derived mesenchymal stem cells(h WJ-MSCs)have excellent proliferative ability,differentiation ability,low immunogenicity,and can be easily obtained.However,there are few studies on their application in the treatment of ischemic stroke,therefore their therapeutic effect requires further verification.In this study,h WJ-MSCs were transplanted into an ischemic stroke rat model via the tail vein 48 hours after transient middle cerebral artery occlusion.After 4 weeks,neurological functions of the rats implanted with h WJ-MSCs were significantly recovered.Furthermore,many h WJ-MSCs homed to the ischemic frontal cortex whereby they differentiated into neuron-like cells at this region.These results confirm that h WJ-MSCs transplanted into the ischemic stroke rat can differentiate into neuron-like cells to improve rat neurological function and behavior.     

Update on Therapeutic Mechanism for Bone Marrow Stromal Cells in Ischemic Stroke

Cerebral ischemia is a major cause of morbidity and mortality in the aged population, as well as a tremendous burden on the healthcare system. Despite timely treatment with thrombolysis and percutaneous intravascular interventions, many patients are often left with irreversible neurological deficits. Bone marrow stromal cells (BMSCs), also referred to as mesenchymal stem cells (MSCs), are a type of nonhematopoietic stem cells which exists in bone marrow mesh, with the potential to self-renew. Unlike cells in the central nervous system, BMSCs differentiate not only into mesodermal cells, but also endodermal and ectodermal cells. Moreover, it has been reported that BMSCs develop into cells with neural and vascular markers and play a role in recovery from ischemic stroke. These findings have fuelled excitement in regenerative medicine for neurological diseases, especially for ischemic stroke. There is now preclinical evidence to suggest that BMSCs grafted into the brain of ischemic models abrogate neurological deficits. Based on the overwhelming evidence from animal studies as well as in clinical trials, BMSC transplantation is considered a promising strategy for treatment of ischemic stroke. The goal of this review is to present an integrated consideration of molecular mechanisms in a chronological fashion and discuss an optimal BMSC delivery route for ischemic stroke.     

Therapeutic strategy of erythropoietin in neurological disorders

Erythropoietin (EPO) was first identified as a hematopoietic cytokine that stimulates proliferation and differentiation of erythroid progenitor cells and was approved by the Food and Drug Administration as a treatment for chronic renal disease patients with anemia. In neural tissues, EPO is working via EPO receptors and induces non-hematopoietic effects. Recent studies have demonstrated that EPO exerts therapeutic potentials on neurological disorders such as ischemic stroke, intracerebral hemorrhage, subarachnoid hemorrhage, traumatic brain injury, and Parkinson's disease. EPO treatment has been shown to reduce the ischemic infarct and hemorrhage volume, decrease neuronal death including apoptosis, and improve survival rates in animal models. The mechanism of EPO action in neurological disorders involves neuroprotection and promotion of neurogenesis and angiogenesis. Clinical trials of EPO treatments in neurological diseases have accumulated positive results. In stroke patients, EPO treatment may reduce infarct volume and improve functional outcomes. EPO administration has proven safe in animal studies and adult human patients, although safety and efficacy data in neonates and infants are incomplete and long-term multi-center patient evaluations are necessary. Available information suggests that EPO is a promising therapeutic drug for the treatment of neurological diseases.     

Granulocyte-macrophage colony-stimulating factor-transfected bone marrow stromal cells for the treatment of ischemic stroke

Adult,male,Sprague-Dawley rats were injected with granulocyte-macrophage colony-stimulating factor-transfected bone marrow stromal cells(GM-CSF-BMSCs) into the ischemic boundary zone at 24 hours after onset of middle cerebral artery occlusion.Results showed reduced infarct volume,decreased number of apoptotic cells,improved neurological functions,increased angiogenic factor expression,and increased vascular density in the ischemic boundary zone in rats that underwent GM-CSF-BMSCs transplantation compared with the BMSCs group.Experimental findings suggested that GM-CSF-BMSCs could serve as a potential therapeutic strategy for ischemic stroke and are superior to BMSCs alone.     

Change and predictive ability of circulating immunoregulatory lymphocytes in long-term outcomes of acute ischemic stroke

Lymphocytes play an important role in the immune response after stroke. However, our knowledge of the circulating lymphocytes in ischemic stroke is limited. Herein, we collected the blood samples of clinical ischemic stroke patients to detect the change of lymphocytes from admission to 3 months after ischemic stroke by flow cytometry. A total of 87 healthy controls and 210 patients were enrolled, and the percentages of circulating T cells, CD4⁺ T cells, CD8⁺ T cells, double negative T cells (DNTs), CD4⁺ regulatory T cells (Tregs), CD8⁺ Tregs, B cells and regulatory B cells (Bregs) were measured. Among patients, B cells, Bregs and CD8⁺ Tregs increased significantly, while CD4⁺ Tregs dropped and soon reversed after ischemic stroke. CD4⁺ Tregs, CD8⁺ Tregs, and DNTs also showed high correlations with the infarct volume and neurological scores of patients. Moreover, these lymphocytes enhanced the predictive ability of long-term prognosis of neurological scores when added to basic clinical information. The percentage of CD4⁺ Tregs within lymphocytes showed high correlations with both acute and long-term neurological outcomes, which exhibited a great independent predictive ability. These findings suggest that CD4⁺ Tregs can be a biomarker to predict stroke outcomes and improve existing therapeutic strategies of immunoregulatory lymphocytes.     

干细胞移植治疗缺血性脑卒中的研究与现状

近年来，随着成年个体神经系统内神经干细胞的发现以及对其研究的不断深入，应用干细胞治疗缺血性脑卒中受到各国学者的广泛关注。大量的实验研究表明，干细胞可从不同程度上改善脑卒中后的神经功能，具有良好的临床应用前景。目前此类研究主要集中于2种途径，其一是利用内源性神经干细胞的激活治疗脑卒中，其二是利用外源性干细胞移植治疗脑卒中。文章就近年来应用各种干细胞治疗缺血性脑卒中的动物及临床实验研究现状进行综述，并对其存在的问题进行了分析和展望。