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.     

外泌体在卵巢癌诊疗及转移中的研究进展

卵巢癌是妇科肿瘤领域内的一个热点主题。该种恶性肿瘤疾病的发病率高且隐匿,缺乏有效的早期发现及时诊断并治疗的方式,病情容易加重发生远处转移。因此罹患卵巢癌的女性5年生存率比较低。外泌体属于一类典型的囊性泡样的小体,参与肿瘤的发病及转移机制且在肿瘤疾病的治疗中起着重要作用。本篇综述主要介绍癌细胞外泌体在卵巢恶性肿瘤疾病的诊断、转移及治疗中的研究现状。     

胎牛血清外泌体对成骨细胞增殖的作用

背景:研究表明外泌体具有促进骨再生的能力,但从胎牛血清中提取的外泌体是否可以促进骨形成仍存在争议。目的:观察胎牛血清外泌体对成骨细胞增殖能力的影响,从而为临床治疗骨破坏提供新思路。方法:通过超速离心法从胎牛血清中提取外泌体,采用透射电子显微镜和Western blot法验证外泌体是否提取成功;然后用10 mg/L胎牛血清外泌体干预成骨前体细胞MC3T3-E1,通过CCK-8实验检测外泌体对成骨细胞增殖能力的影响,Western blot检测外泌体对成骨细胞骨形态发生蛋白2和骨桥蛋白表达的影响。以不含外泌体的胎牛血清培养的MC3T3-E1细胞为对照组。结果与结论:①胎牛血清外泌体具有典型的脂质双层膜结构,大小在30-150 nm之间,外泌体表面标记因子CD81表达呈阳性,而微囊表面标记物CD40表达呈阴性;②外泌体组的增殖能力明显高于对照组,差异有显著性意义(P<0.05);外泌体组成骨标志性因子骨形态发生蛋白2和骨桥蛋白的表达水平明显高于对照组,差异有显著性意义(P<0.05);③结果表明,胎牛血清外泌体对成骨细胞的增殖起促进作用,可为临床治疗骨破坏提供新思路。     

Human Milk Exosomal MicroRNA: Associations with Maternal Overweight/Obesity and Infant Body Composition at 1 Month of Life

Among all the body fluids, breast milk is one of the richest sources of microRNAs (miRNAs). MiRNAs packaged within the milk exosomes are bioavailable to breastfeeding infants. The role of miRNAs in determining infant growth and the impact of maternal overweight/obesity on human milk (HM) miRNAs is poorly understood. The objectives of this study were to examine the impact of maternal overweight/obesity on select miRNAs (miR-148a, miR-30b, miR-29a, miR-29b, miR-let-7a and miR-32) involved in adipogenesis and glucose metabolism and to examine the relationship of these miRNAs with measures of infant body composition in the first 6 months of life. Milk samples were collected from a cohort of 60 mothers (30 normal-weight [NW] and 30 overweight [OW]/obese [OB]) at 1-month and a subset of 48 of these at 3 months of lactation. Relative abundance of miRNA was determined using real-time PCR. The associations between the miRNAs of interest and infant weight and body composition at one, three, and six months were examined after adjusting for infant gestational age, birth weight, and sex. The abundance of miR-148a and miR-30b was lower by 30% and 42%, respectively, in the OW/OB group than in the NW group at 1 month. miR-148a was negatively associated with infant weight, fat mass, and fat free mass, while miR-30b was positively associated with infant weight, percent body fat, and fat mass at 1 month. Maternal obesity is negatively associated with the content of select miRNAs in human milk. An association of specific miRNAs with infant body composition was observed during the first month of life, suggesting a potential role in the infant’s adaptation to enteral nutrition.     

Immune activation by nucleic acids: A role in pregnancy complications

Cell‐free self‐DNA or RNA may induce an immune response by activating specific sensing receptors. During pregnancy, placental nucleic acids present in the maternal circulation further activate these receptors due to the presence of unmethylated CpG islands. A higher concentration of cell‐free foetal DNA is associated with pregnancy complications and a higher risk for foetal rejection. Cell‐free foetal DNA originates from placental trophoblasts. It appears in different forms: free, bound to histones in nucleosomes, in neutrophil extracellular traps (NETs) and in extracellular vesicles (EVs). In several pregnancy complications, cell‐free foetal DNA triggers the production of proinflammatory cytokines, and this production results in a cellular and humoral immune response. This review discusses preeclampsia, systemic lupus erythematosus, foetal growth restriction, gestational diabetes, rheumatoid arthritis and obesity in pregnancy from an immunological point of view and closely examines the different pathways that result in maternal inflammation. Understanding the role of cell‐free nucleic acids, as well as the biogenesis of NETs and EVs, will help us to specify their functions or targets, which seem to be important in pregnancy complications. It is still not clear whether higher concentrations of cell‐free nucleic acids in the maternal circulation are the cause or consequence of various complications. Therefore, further clinical studies and, even more importantly, animal experiments that focus on the involved immunological pathways are needed.     

外泌体在胰腺癌中的研究现状与进展

外泌体是一种双层脂质膜连接囊泡样小体，存在于各种体液中，参与细胞及肿瘤微环境之间的物质运输和信号传递。外泌体含有多种生物活性分子，包括脂质、蛋白质、DNA、mRNA以及非编码RNA，可以通过这些活性分子影响肿瘤的发生和发展，甚至可以影响肿瘤的治疗。胰腺癌是一种常见的恶性肿瘤，侵袭性强，预后较差，死亡率高。胰腺癌来源的外泌体是胰腺肿瘤微环境中的重要组成部分，促使胰腺癌细胞成功逃避细胞凋亡的重要因素，并且可以促进肝脏转移微环境的形成。近年来，与胰腺癌相关的外泌体逐渐成为新的研究热点，研究发现外泌体有望成为早期胰腺癌筛查的新型生物学标志，并将为胰腺癌靶向治疗提供可行的技术基础。     

Implication of Human Endogenous Retrovirus Envelope Proteins in Placental Functions

Human endogenous retroviruses (ERVs) represent 8% of the total human genome. Although the majority of these ancient proviral sequences have only retained non-coding long terminal repeats (LTRs), a number of “endogenized” retroviral genes encode functional proteins. Previous studies have underlined the implication of these ERV-derived proteins in the development and the function of the placenta. In this review, we summarize recent findings showing that two ERV genes, termed Syncytin-1 and Syncytin-2, which encode former envelope (Env) proteins, trigger fusion events between villous cytotrophoblasts and the peripheral multinucleated syncytiotrophoblast layer. Such fusion events maintain the stability of this latter cell structure, which plays an important role in fetal development by the active secretion of various soluble factors, gas exchange and regulation of fetomaternal immunotolerance. We also highlight new studies showing that these ERV proteins, in addition to their localization at the cell surface of cytotrophoblasts, are also incorporated on the surface of various extracellular microvesicles, including exosomes. Such exosome-associated proteins could be involved in the various functions attributed to these vesicles and could provide a form of tropism. Additionally, through their immunosuppressive domains, these ERV proteins could also contribute to fetomaternal immunotolerance in a local and more distal manner. These various aspects of the implication of Syncytin-1 and -2 in placental function are also addressed in the context of the placenta-related disorder, preeclampsia.     

HucMSC-Derived Exosomes Mitigate the Age-Related Retardation of Fertility in Female Mice

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The Secret Life of Exosomes: What Bees Can Teach Us About Next-Generation Therapeutics

Mechanistic exploration has pinpointed nanosized extracellular vesicles, known as exosomes, as key mediators of the benefits of cell therapy. Exosomes appear to recapitulate the benefits of cells and more. As durable azoic entities, exosomes have numerous practical and conceptual advantages over cells. Will cells end up just being used to manufacture exosomes, or will they find lasting value as primary therapeutic agents? Here, a venerable natural process—the generation of honey—serves as an instructive parable. Flowers make nectar, which bees collect and process into honey. Cells make conditioned medium, which laboratory workers collect and process into exosomes. Unlike flowers, honey is durable, compact, and nutritious, but these facts do not negate the value of flowers themselves. The parallels suggest new ways of thinking about next-generation therapeutics.     

Investigational agents for treatment of traumatic brain injury

Introduction: Traumatic brain injury (TBI) is a major cause of death and disability worldwide. To date, there are no pharmacologic agents proven to improve outcomes from TBI because all the Phase III clinical trials in TBI have failed. Thus, there is a compelling need to develop treatments for TBI.

Areas covered: The following article provides an overview of select cell-based and pharmacological therapies under early development for the treatment of TBI. These therapies seek to enhance cognitive and neurological functional recovery through neuroprotective and neurorestorative strategies.

Expert opinion: TBI elicits both complex degenerative and regenerative tissue responses in the brain. TBI can lead to cognitive, behavioral, and motor deficits. Although numerous promising neuroprotective treatment options have emerged from preclinical studies that mainly target the lesion, translation of preclinical effective neuroprotective drugs to clinical trials has proven challenging. Accumulating evidence indicates that the mammalian brain has a significant, albeit limited, capacity for both structural and functional plasticity, as well as regeneration essential for spontaneous functional recovery after injury. A new therapeutic approach is to stimulate neurovascular remodeling by enhancing angiogenesis, neurogenesis, oligodendrogenesis, and axonal sprouting, which in concert, may improve neurological functional recovery after TBI.