丁苯酞对急性缺血性卒中患者外周血内皮祖细胞的影响

目的 观察丁苯酞(NBP)治疗对急性缺血性卒中患者外周血内皮祖细胞(EPCs)水平及美国国立卫生研究院卒中量表(NIHSS)评分的影响;探讨其疗效及潜在机制.方法 筛选首次发病48 h内入院的急性缺血性卒中患者96例,按随机数字表分为NBP治疗组(NBP组)及安慰剂组.NBP治疗30 d为1个疗程.流式细胞仪检测CD34 +/CD133 +/KDR+标记细胞作为EPCs标志.分别检测入院当天(基线期)、治疗第7天、第14天和第30天外周血EPCs水平;并分别于上述时间点及病程90 d时进行NIHSS评分.结果 NBP组第7天、第14天、第30天时EPCs数量较基线期显著增加(均为P＜0.05);且明显高于同期安慰剂组(分别为P＜0.05、P＜0.001、P＜0.001).NBP组第7天NIHSS评分较基线期无明显改善(P ＞0.05);NBP组第14天、第30天NIHSS评分均明显低于基线期(均为P＜0.05)及同期安慰剂组(P ＜0.05、P＜0.001).NBP组第90天NIHSS评分较第30天有进一步降低(P＜0.05).发病后3个月内NBP组缺血事件稍低于安慰剂组(P＞0.05).两组随访期内均无严重不良事件发生.结论 NBP治疗可显著改善急性缺血性卒中神经功能评分,可能通过提高外周血EPCs水平,改善预后,且安全性良好.     

Growth factor- and cytokine-stimulated endothelial progenitor cells in post-ischemic cerebral neovascularization

Endothelial progenitor cells are resident in the bone marrow blood sinusoids and circulate in the peripheral circulation. They mobilize from the bone marrow after vascular injury and home to the site of injury where they differentiate into endothelial cells. Activation and mobilization of endothelial progenitor cells from the bone marrow is induced via the production and release of endothelial progenitor cell-activating factors and includes specific growth factors and cytokines in response to peripheral tissue hypoxia such as after acute ischemic stroke or trauma. Endotheli- al progenitor cells migrate and home to specific sites following ischemic stroke via growth factor/ cytokine gradients. Some growth factors are less stable under acidic conditions of tissue isch- emia, and synthetic analogues that are stable at low pH may provide a more effective therapeutic approach for inducing endothelial progenitor cell mobilization and promoting cerebral neovascularization following ischemic stroke.     

内皮前体细胞在脑缺血中作用的研究进展

急性脑缺血发生后,及时有效的血管再通、血流重建对于脑细胞的保护作用至关重要。目前,主要有脉管内注入纤维蛋白溶解物、血管内介入治疗、外科治疗等,具体术式主要包括经皮腔血管成形术和支架植入术（PTAS）和血栓切除术。尽管溶栓和介入治疗已经取得一定的疗效,但静脉内应用重组人组织纤溶酶原激活剂（rt—PA）,时间窗非常窄（3～4．5h）,PTAS在发病后第1年具有高风险脑缺血复发率（20％）。     

Outgrowth endothelial cells form a functional cerebral barrier and restore its integrity after damage

Breakdown of blood-brain barrier,formed mainly by brain microvascular endothelial cells(BMECs),represents the major cause of mortality during early phases of ischemic strokes.Hence,discovery of novel agents that can effectively replace dead or dying endothelial cells to restore blood-brain barrier integrity is of paramount importance in stroke medicine.Although endothelial progenitor cells(EPCs)represent one such agents,their rarity in peripheral blood severely limits their adequate isolation and therapeutic use for acute ischemic stroke which necessitate their ex vivo expansion and generate early EPCs and outgrowth endothelial cells(OECs)as a result.Functional analyses of these cells,in the present study,demonstrated that only OECs endocytosed DiI-labelled acetylated low-density lipoprotein and formed tubules on matrigel,prominent endothelial cell and angiogenesis markers,respectively.Further analyses by flow cytometry demonstrated that OECs expressed specific markers for sternness(CD34),immaturity(CD133)and endothelial cells(CD31)but not for hematopoietic cells(CD45).Like BMECs,OECs established an equally tight in vitro model of human BBB with astrocytes and pericytes,suggesting their capacity to form tight junctions.Ischemic injury mimicked by concurrent deprivation of oxygen and glucose(4 hours)or deprivation of oxygen and glucose followed by reperfusion(20 hours)affected both barrier integrity and function in a similar fashion as evidenced by decreases in transendothelial electrical resistance and increases in paracellular flux,respectively.Wound scratch assays comparing the vasculoreparative capacity of cells revealed that,compared to BMECs,OECs possessed a greater proliferative and directional migratory capacity.In a triple culture model of BBB established with astrocytes,pericytes and BMEC,exogenous addition of OECs effectively repaired the damage induced on endothelial layer in serum-free conditions.Taken together,these data demonstrate that OECs may effectively home to the site of vascular injury and repair the damage to maintain(neuro)vascular homeostasis during or after a cerebral ischemic injury.     

Endothelial progenitor cells,potential biomarkers for diagnosis and prognosis of ischemic stroke: protocol for an observational case-control study

Ischemic stroke is a devastating,life altering event which can severely reduce patient quality of life.Despite years of research there have been minimal therapeutic advances.Endothelial progenitor cells(EPCs),stem cells involved in both vasculogenesis and angiogenesis,may be a potential therapeutic target.After a stroke,EPCs migrate to the site of ischemic injury to repair cerebrovascular damage,and their numbers and functional capacity may determine patients'outcome.This study aims to determine whether the number of circulating EPCs and their functional aspects may be used as biomarkers to identify the type(cortical or lacunar)and/or severity of ischemic stroke.The study will also investigate if there are any differences in these characteristics between healthy volunteers over and under 65 years of age.100 stroke patients(50 lacunar and 50 cortical strokes)will be recruited in this prospective,observational case-controlled study.Blood samples will be taken from stroke patients at baseline(within 48 hours of stroke)and days 7,30 and90.EPCs will be counted with flow cytometry.The plasma levels of pro-and anti-angiogenic factors and inflammatory cytokines will also be determined.Outgrowth endothelial cells will be cultured to be used in tube formation,migration and proliferation functional assays.Primary outcome is disability or dependence on day 90 after stroke,assessed by the modified Rankin Scale.Secondary outcomes are changes in circulating EPC numbers and/or functional capacity between patient and healthy volunteers,between patient subgroups and between elderly and young healthy volunteers.Recruitment started in February 2017,167 participants have been recruited.Recruitment will end in November 2019.West Midlands-Coventry&Warwickshire Research Ethics Committee approved this study(REC number:16/WM/0304)on September8,2016.Protocol version:2.0.The Bayraktutan Dunhill Medical Trust EPC Study was registered in ClinicalTrials.gov(NCT02980354)on November 15,2016.This study will determine whether the number of EPCs can be used as a prognostic or diagnostic marker for ischemic strokes and is a step towards discovering if transplantation of EPCs may aid patient recovery.     

Bone marrow-derived endothelial progenitor cells protect postischemic axons after traumatic brain injury

White matter sparing after traumatic brain injury (TBI) is an important predictor of survival and outcome. Blood vessels and axons are intimately associated anatomically and developmentally. Neural input is required for appropriate vascular patterning, and vascular signaling is important for neuron development and axon growth. Owing to this codependence between endothelial cells and axons during development and the contribution of endothelial progenitor cells (EPCs) in ischemic injury, we hypothesized that EPCs are important in axonal survival after TBI. We examined the effects of allogenic-cultured EPCs on white matter protection and microvascular maintenance after midline fluid percussion injury in adult Sprague–Dawley rats. We used two in vitro models of injury, mechanical stretch and oxygen–glucose deprivation (OGD), to examine the effects of EPCs on the mechanical and ischemic components of brain trauma, respectively. Our results indicate that EPCs improve the white matter integrity and decrease capillary breakdown after injury. Cultured cortical neurons exposed to OGD had less axon degeneration when treated with EPC-conditioned media, whereas no effect was seen in axons injured by mechanical stretch. The results indicate that EPCs are important for the protection of the white matter after trauma and represent a potential avenue for therapy.     

Temporal profile of molecular signatures associated with circulating endothelial progenitor cells in human ischemic stroke

Endothelial progenitor cells (EPC) have been associated with good functional outcome in ischemic stroke. From preclinical studies, it has been reported that EPC proliferation is mediated by several molecular markers, including vascular endothelial growth factor (VEGF), stromal cell-derived factor-1α (SDF-1α), and the activity of matrix metalloproteinase-9 (MMP-9). Therefore, our aim was to study the role of these molecular factors in EPC proliferation in human ischemic stroke. Forty-eight patients with first episode of nonlacunar ischemic stroke were prospectively included in the study within 12 hr of symptom onset. EPC colonies were classified as early-outgrowth colony forming unit-endothelial cell (CFU-EC) and quantified at admission, at 24 and 72 hr, at day 7, and at 3 months. At the same time, serum levels of VEGF, SDF-1α, and active MMP-9 were measured by ELISA. The primary endpoint was EPC increment during the first week, which was defined as the difference in the number of CFU-EC between day 7 and admission. We found that VEGF (r = 0.782), SDF-1α (r = 0.828), and active MMP-9 (r = 0.740) levels at 24 hr from stroke onset showed a strong correlation with EPC increment. Similar results were found for VEGF levels at 72 hr (r = 0.839) and at day 7 (r = 0.602) as well as for active MMP-9 levels at 72 hr (r = 0.442) and at day 7 (r = 0.474). In the multivariate analyses, serum levels of VEGF at 72 hr (B: 0.074, P < 0.0001) and SDF-1α at 24 hr (B: 0.049, P = 0.008) were independent factors for EPC increment during the first week of evolution. These findings suggest that VEGF and SDF-1α may mediate EPC proliferation in human ischemic stroke.     

Neural progenitor cell transplants promote long-term functional recovery after traumatic brain injury

Studies demonstrating the versatility of neural progenitor cells (NPCs) have recently rekindled interest in neurotransplantation methods aimed at treating traumatic brain injury (TBI). However, few studies have evaluated the safety and functional efficacy of transplanted NPCs beyond a few months. The purpose of this study was to assess the long-term survival, migration, differentiation and functional significance of NPCs transplanted into a mouse model of TBI out to 1 year post-transplant. NPCs were derived from E14.5 mouse brains containing a transgene-expressing green fluorescent protein (GFP) and cultured as neurospheres in FGF2-containing medium. Neurospheres were injected into the ipsilateral striatum of adult C57BL/6 mice 1 week following unilateral cortical impact injury. Behavioral testing revealed significant improvements in motor abilities in NPC-treated mice as early as 1 week, and the recovery was sustained out to 1 year post-transplant. In addition, mice receiving NPC transplants showed significant improvement in spatial learning abilities at 3 months and 1 year, whereas an intermediate treatment effect on this behavioral parameter was detected at 1 month. At 14 months post-transplant, GFP(+) NPCs were observed throughout the injured hippocampus and adjacent cortical regions of transplanted brains. Immunohistochemical analysis revealed that the majority of transplanted cells co-labeled for NG2, an oligodendrocyte progenitor cell marker, but not for neuronal, astrocytic or microglial markers. In conclusion, transplanted NPCs survive in the host brain up to 14 months, migrate to the site of injury, enhance motor and cognitive recovery, and may play a role in trophic support following TBI.     

Rab27a‐dependent exosomes protect against cerebral ischemic injury by reducing endothelial oxidative stress and apoptosis

IntroductionMulticellular crosstalk within the brain tissue has been suggested to play a critical role in maintaining cerebral vascular homeostasis. Exosomes (EXs) mediated cell–cell communication, but its role in cerebral ischemic injury is largely unknown. Rab27a is one of the major genes controlling EX release. Here, we explored the role of Rab27a in regulating brain EXs secretion, and the effects of Rab27a‐mediated EXs on ischemia evoked cerebral vascular disruption and brain injury.MethodsCerebral ischemia was induced in Rab27a knockout (Rab27a^−/−) and wide type (WT) mice by transient middle cerebral artery occlusion (tMCAO). Differential gene expression analysis was performed in ischemic brain tissue by using mRNA sequencing. EXs isolated from brain tissue of Rab27a^−/− and WT mice (EX^WT or EX^{Rab27a−/−}) were pre‐administrated into tMCAO operated Rab27a^−/− mice or oxygen and glucose deprivation (OGD) treated primary brain vascular endothelial cells (ECs).ResultsWe demonstrated that Rab27a expression in the peri‐infarct area of brain was significantly elevated, which was associated with local elevation in EXs secretion. Rab27a deficiency dramatically decreased the level of EXs in brain tissue of normal and tMCAO‐treated mice, and Rab27a^−/− mice displayed an increase in infarct volume and NDS, and a decrease in cMVD and CBF following tMCAO. Pre‐infusion of EX^WT increased the brain EXs levels in the tMCAO operated Rab27a^−/− mice, accompanied with an increase in cMVD and CBF, and a decrease in infarct volume, NDS, ROS production, and apoptosis. The effects of EX^{Rab27a−/−} infusion were much diminished although in a dose‐dependent manner. In OGD‐treated ECs, EX^{Rab27a−/−} showed less effectivity than EX^WT in decreasing ROS overproduction and apoptosis, paralleling with down‐regulated expression of NOX2 and cleaved caspase‐3.ConclusionOur study demonstrates that Rab27a controls brain EXs secretion and functions, contributing to cerebral vascular protection from ischemic insult by preventing oxidative stress and apoptosis via down‐regulating NOX2 and cleaved caspase‐3 expression.     

人脐带血内皮祖细胞体外培养和鉴定

传统免疫磁珠法分选内皮祖细胞的方法操作复杂、费用大,细胞获得率较低,且内皮祖细胞的增生及分化受限。 目的：尝试改良人脐带血内皮祖细胞体外诱导分化及鉴定的方法,为实现内皮祖细胞移植、改善血管功能提供足量细胞来源。 方法：采用密度梯度离心方法获得人带血单个核细胞,体外进行诱导、分化和扩增,通过免疫组织化学、免疫荧光和流式细胞仪等技术对脐血来源的内皮祖细胞进行鉴定。 结果与结论：脐带血单个核细胞在培养过程中出现梭形贴壁和铺路石样等形态;在细胞培养至第7天,免疫组织化学显示：CD31、vWF在体外培养过程中的表达阳性;免疫荧光染色表明：(83.0±4.3)%的贴壁细胞双染呈阳性,并且DiI-acLDL标记的内皮祖细胞红色荧光在体外可以持续6周以上;第7天贴壁细胞流式细胞仪分析显示：CD34、CD133和KDR分别为(17.8±3.7)%、(22.1±4.4)%、(81.5±5.0)%。结果提示,实验成功从脐带血单个核细胞中分离培养出内皮祖细胞,在其体外可扩增并向为内皮细胞方向分化。     

The secretome of endothelial progenitor cells: a potential therapeutic strategy for ischemic stroke

Ischemic stroke continues to be a leading cause of mortality and morbidity in the world. Despite recent advances in the field of stroke medicine, thrombolysis with recombinant tissue plasminogen activator remains as the only pharmacological therapy for stroke patients. However, due to short therapeutic window(4.5 hours of stroke onset) and increased risk of hemorrhage beyond this point, each year globally less than 1% of stroke patients receive this therapy which necessitate the discovery of safe and efficacious therapeutics that can be used beyond the acute phase of stroke. Accumulating evidence indicates that endothelial progenitor cells(EPCs), equipped with an inherent capacity to migrate, proliferate and differentiate, may be one such therapeutics. However, the limited availability of EPCs in peripheral blood and early senescence of few isolated cells in culture conditions adversely affect their application as effective therapeutics. Given that much of the EPC-mediated reparative effects on neurovasculature is realized by a wide range of biologically active substances released by these cells, it is possible that EPC-secretome may serve as an important therapeutic after an ischemic stroke. In light of this assumption, this review paper firstly discusses the main constituents of EPC-secretome that may exert the beneficial effects of EPCs on neurovasculature, and then reviews the currently scant literature that focuses on its therapeutic capacity.     

不同来源内皮祖细胞培养及其生物学特性比较

背景：在缺血性疾病中,机体的代偿性反应包括细小动脉形成和血管新生,而内皮祖细胞在其中发挥着重要的作用,参与了机体多种生理、病理性血管重建过程。目前对内皮祖细胞的来源、生物学特性还存在许多争议。 目的：分离培养人外周血、脐带血、骨髓以及脐带来源的内皮祖细胞,并对其生物学特性进行比较。 方法：采用密度梯度离心法分离人外周血、脐带血以及骨髓单个核细胞进行贴壁培养,脐带来源的内皮祖细胞通过植块贴壁培养或胶原酶消化脐静脉内膜获得的单个核细胞进行贴壁培养。对获得的贴壁细胞进行细胞形态学、增殖活力、细胞周期、免疫表型的检测。 结果与结论：①外周血与脐带血来源的贴壁细胞呈长梭形,集落状生长,其上附有成簇圆形细胞,随着培养时间延长,圆形细胞渐脱落,梭形细胞无明显增殖趋势,消化后细胞不能传代;流式显示细胞高表达CD45,部分表达KDR,但不表达CD31。②骨髓和脐带来源的贴壁细胞呈短梭形、多角形;传代后细胞增殖迅速,且细胞形态与增殖活力没有明显下降;多数细胞处于G0/G1期;流式检测显示细胞均不表达CD14、CD45,也不表达CD106、HLA-DR,但高表达CD44、CD90、CD62E、CD73、CD95、CD105;部分表达内皮系标记KDR、vWF;酶消化法获得的脐带内皮祖细胞还表达CD31;共聚焦显微镜扫描显示细胞具有吸收ac-LDL并结合UEA-1的能力。结果说明外周血、脐带血、骨髓与脐带组织中可分离培养出分化程度、增殖活力不同的内皮祖细胞。     

Relationships between vascular dysfunction, circulating endothelial progenitor cells, and psychological status in healthy subjects

Background: Although the mechanisms remain unclear, depression and mental stress are associated with endothelial dysfunction and increases risk of cardiovascular disease (CVD). Recent studies suggest that circulating endothelial progenitor cells (EPC) play an important role in endothelial repair and correlate with endothelial function. Methods: We studied the relationship between the level of circulating CD34/KDR⁺ EPCs and CD133/KDR⁺ EPCs, brachial artery flow‐mediated dilation (FMD), Depression Anxiety Stress Scales in 129 normal individuals (54 ± 10 years, 54 men) without prior CVD or diabetes. Results: Their median depression score (DS) and stress score (SS) was 4 (range 0–34) and 6 (range 0–32), respectively. As defined by the ≥75th percentile, 41 subjects (32%) had high DS (≥8) and 31 (24%) had high SS (≥14). Subjects with high DS had significantly lower FMD (5.4 ± 2.7 versus 8.0 ± 4.0%, P<0.001) and percentage of CD34/KDR⁺ EPC (1.2 ± 1.3 versus 2.0 ± 2.4%, P = 0.037), but not CD133/KDR⁺ EPC (0.56 ± 0.42 versus 0.68 ± 0.76%, P = 0.44), than those with normal DS. In contrast, there were no significant difference in FMD (6.8 ± 3.5 versus 7.3 ± 3.9%, P = 0.46), percentages of circulating CD34/KDR⁺ EPC (1.20 ± 1.28 versus 1.95 ± 2.34%, P = 0.052) and CD133/KDR⁺ EPC (0.55 ± 0.41 versus 0.67 ± 0.73%, P = 0.52) between subjects with high and normal SS. Multivariate regression analysis revealed that high DS (OR 1.08, 95% CI: 1.02–1.15, P = 0.010) and old age (OR 1.05, 95% CI: 1.01–1.10, P = 0.019), but not SS or percentage of circulating EPC, were independent predictors for decreased FMD. Conclusions: Our results demonstrated that, in subjects without significant CVD, a high DS was associated with impaired brachial FMD and depletion of circulating EPC. However, only DS, but not SS or EPC count, was an independent predictor for impaired brachial FMD. Depression and Anxiety, 2011. © 2011 Wiley‐Liss, Inc.     

Changes and function of circulating endothelial progenitor cells in patients with cerebral aneurysm

Endothelial dysfunction is a trigger for the formation of cerebral aneurysm (CA). The circulating endothelial progenitor cell (EPC) plays an important role in postnatal vasculogenesis and reduction of endothelial injury. In this study, we tested the hypothesis that decreased number and impaired function of circulating EPCs correlate with CA formation in patients. Blood circulating EPCs were identified by flow cytometry. The level of plasma vascular endothelial growth factor (VEGF) was measured by ELISA. Circulating EPCs from patients (n = 27) were cultured in vitro, and the function of EPCs was evaluated by cell migration and senescence-associated β-galactosidase activity. The number of circulating EPCs was significantly decreased in both unruptured and ruptured CA patients compared with healthy control subjects. Impaired migratory capacity and elevated cellular senescence of cultured EPCs were observed in patients with CA (ruptured and unruptured). The percentages of EPC senescence in patients with CAs were significantly and negatively correlated with the number of circulating EPCs. In addition, there were higher levels of plasma VEGF in CA patients compared with healthy control subjects. Our results show that the numbers and functions of circulating EPCs are reduced in patients with CAs. These findings suggest that the decreased number and impaired function of circulating EPCs in CA patients may contribute to the pathophysiological process of aneurysm formation.     

Cerebral endothelial cell-derived small extracellular vesicles enhance neurovascular function and neurological recovery in rat acute ischemic stroke models of mechanical thrombectomy and embolic stroke treatment with tPA

Treatment of patients with cerebral large vessel occlusion with thrombectomy and tissue plasminogen activator (tPA) leads to incomplete reperfusion. Using rat models of embolic and transient middle cerebral artery occlusion (eMCAO and tMCAO), we investigated the effect on stroke outcomes of small extracellular vesicles (sEVs) derived from rat cerebral endothelial cells (CEC-sEVs) in combination with tPA (CEC-sEVs/tPA) as a treatment of eMCAO and tMCAO in rat. The effect of sEVs derived from clots acquired from patients who had undergone mechanical thrombectomy on healthy human CEC permeability was also evaluated. CEC-sEVs/tPA administered 4 h after eMCAO reduced infarct volume by ∼36%, increased recanalization of the occluded MCA, enhanced cerebral blood flow (CBF), and reduced blood-brain barrier (BBB) leakage. Treatment with CEC-sEVs given upon reperfusion after 2 h tMCAO significantly reduced infarct volume by ∼43%, and neurological outcomes were improved in both CEC-sEVs treated models. CEC-sEVs/tPA reduced a network of microRNAs (miRs) and proteins that mediate thrombosis, coagulation, and inflammation. Patient-clot derived sEVs increased CEC permeability, which was reduced by CEC-sEVs. CEC-sEV mediated suppression of a network of pro-thrombotic, -coagulant, and -inflammatory miRs and proteins likely contribute to therapeutic effects. Thus, CEC-sEVs have a therapeutic effect on acute ischemic stroke by reducing neurovascular damage.     

Early effect of thrombolysis on structural brain network organisation after anterior‐circulation stroke in the randomized WAKE‐UP trial

The symptoms of acute ischemic stroke can be attributed to disruption of the brain network architecture. Systemic thrombolysis is an effective treatment that preserves structural connectivity in the first days after the event. Its effect on the evolution of global network organisation is, however, not well understood. We present a secondary analysis of 269 patients from the randomized WAKE‐UP trial, comparing 127 imaging‐selected patients treated with alteplase with 142 controls who received placebo. We used indirect network mapping to quantify the impact of ischemic lesions on structural brain network organisation in terms of both global parameters of segregation and integration, and local disruption of individual connections. Network damage was estimated before randomization and again 22 to 36 h after administration of either alteplase or placebo. Evolution of structural network organisation was characterised by a loss in integration and gain in segregation, and this trajectory was attenuated by the administration of alteplase. Preserved brain network organization was associated with excellent functional outcome. Furthermore, the protective effect of alteplase was spatio‐topologically nonuniform, concentrating on a subnetwork of high centrality supported in the salvageable white matter surrounding the ischemic cores. This interplay between the location of the lesion, the pathophysiology of the ischemic penumbra, and the spatial embedding of the brain network explains the observed potential of thrombolysis to attenuate topological network damage early after stroke. Our findings might, in the future, lead to new brain network‐informed imaging biomarkers and improved prognostication in ischemic stroke.     

BMPER alleviates ischemic brain injury by protecting neurons and inhibiting neuroinflammation via Smad3‐Akt‐Nrf2 pathway

AimsBone morphogenetic proteins (BMPs) are a group of proteins related to bone morphogenesis. BMP‐binding endothelial regulator (BMPER), a secreted protein that interacts with BMPs, is known to be involved in ischemic injuries. Here, we explored the effects of BMPER on cerebral ischemia and its mechanism of action.MethodsA mouse model of brain ischemia was induced by middle cerebral artery occlusion (MCAO). An in vitro ischemic model was established by subjecting primary cultured neurons to oxygen‐glucose deprivation/reperfusion (OGD/R). Serum levels of BMPs/BMPER were measured in MCAO mice and in patients with acute ischemic stroke (AIS). Brain damages were compared between BMPER‐ and vehicle‐treated mice. Quantitative polymerase chain reaction (qPCR), immunohistochemistry, and immunofluorescence staining were performed to examine neuroinflammation and cell death. BMPER‐related pathways were assessed by Western blotting.ResultsBMPER level was elevated in MCAO mice and AIS patients. BMPER administration reduced mortality, infarct size, brain edema, and neurological deficit after MCAO. Neuroinflammation and cell death after ischemia were alleviated by BMPER both in vivo and in vitro. BMPER activated the Smad3/Akt/Nrf2 pathway in OGD/R‐challenged neurons.ConclusionBMPER is a neuroprotective hormone that alleviates ischemic brain injury via activating the Smad3/Akt/Nrf2 pathway. These findings may provide potential therapeutic strategies for stroke.     

外周血内皮祖细胞数量变化与颅内动脉瘤的生成

背景：动脉内膜损伤是动脉瘤发生的始动因素,内皮祖细胞能修复受损的动脉内膜。 目的：建立大鼠颅内动脉瘤模型,探讨动脉瘤大鼠内皮祖细胞数量变化及意义。 方法：40只SD大鼠随机分为两组,正常组作为正常对照,不给予任何干预。模型组大鼠手术结扎双侧肾动脉后支以及左侧颈总动脉,术后喂食含8%氯化钠鼠粮。于2周,1,2,3个月末测量大鼠内皮祖细胞变化,并与3个月末测量各组大鼠血压及动脉瘤大小,RT-PCR检测willis环相关基因表达。 结果与结论：模型组大鼠内皮祖细胞数目于2周后就开始下降,与正常组比较差异有显著性意义(P < 0.05),一直持续到3个月末(P < 0.01)。模型组大鼠动脉瘤壁基质金属蛋白酶9表达明显高于正常组正常大鼠(P < 0.01),而内皮型一氧化氮合酶明显低于正常(P < 0.05)。结果提示循环内皮祖细胞数量降低可能是动脉瘤生成的一个重要因素。     

Multipotent embryonic spinal cord stem cells expanded by endothelial factors and Shh/RA promote functional recovery after spinal cord injury

Cell transplantation is a promising way to treat spinal cord injury and neurodegenerative disorders. Neural stem cells taken from the embryonic spinal cord are an appealing source of cells for transplantation because these cells are committed to making spinal cord progeny. However these stem cells are rare and require expansion in tissue culture to generate sufficient cells for transplantation. We have developed a novel method for expanding embryonic mouse spinal cord stem cells using a co-culture system with endothelial cells. This method improves neural stem cell survival and preserves their multipotency, including their ability to make motor neurons. Transplantation of endothelial-expanded neural stem cells that were treated with sonic hedgehog(Shh) and retinoic acid (RA) during the expansion phase, into an adult mouse SCI model resulted in significant recovery of sensory and motor function.