Neural stem cell-derived exosomes regulate cell proliferation,migration,and cell death of brain microvascular endothelial cells via the miR-9/Hes1 axis under hypoxia

Background:Our previous study found that mouse embryonic neural stem cell(NSC)-derived exosomes(EXOs)regulated NSC differentiation via the miR-9/Hes1 axis.However,the effects of EXOs on brain microvascular endothelial cell(BMEC)dysfunction via the miR-9/Hes1 axis remain unknown.Therefore,the current study aimed to determine the effects of EXOs on BMEC proliferation,migration,and death via the miR-9/Hes1 axis.Methods:Immunofluorescence,quantitative real-time polymerase chain reaction,cell counting kit-8 assay,wound healing assay,calcein-acetoxymethyl/propidium iodide staining,and hematoxylin and eosin staining were used to determine the role and mechanism of EXOs on BMECs.Results:EXOs promoted BMEC proliferation and migration and reduced cell death under hypoxic conditions.The overexpression of miR-9 promoted BMEC prolifera-tion and migration and reduced cell death under hypoxic conditions.Moreover,miR-9 downregulation inhibited BMEC proliferation and migration and also promoted cell death.Hes1 silencing ameliorated the effect of amtagomiR-9 on BMEC proliferation and migration and cell death.Hyperemic structures were observed in the regions of the hippocampus and cortex in hypoxia-induced mice.Meanwhile,EXO treatment improved cerebrovascular alterations.Conclusion:NSC-derived EXOs can promote BMEC proliferation and migra-tion and reduce cell death via the miR-9/Hes1 axis under hypoxic conditions.Therefore,EXO therapeutic strategies could be considered for hypoxia-induced vascular injury.

β-Estradiol 17-acetate enhances the in vitro vitality of endothelial cells isolated from the brain of patients subjected to neurosurgery

In the current landscape of endothelial cell isolation for building in vitro models of the blood-brain barrier,our work moves towards reproducing the features of the neurovascular unit to achieve glial compliance through an innovative biomimetic coating technology for brain chronic implants.We hypothesized that the autologous origin of human brain mic rovascular endothelial cells(hBMECs)is the first requirement for the suitable coating to prevent the glial inflammato ry response trigge red by foreign neuroprosthetics.Therefo re,this study established a new procedure to preserve the in vitro viability of hBMECs isolated from gray and white matter specimens taken from neurosurge ry patients.Culturing adult hBMECs is generally considered a challenging task due to the difficult survival ex vivo and progressive reduction in proliferation of these cells.The addition of 10 nMβ-estradiol 17-acetate to the hBMEC culture medium was found to be an essential and discriminating factor promoting adhesion and proliferation both after isolation and thawing,suppo rting the well-known protective role played by estrogens on microvessels.In particular,β-estradiol 17-acetate was critical for both freshly isolated and thawed female-derived hBMECs,while it was not necessary for freshly isolated male-derived hBMECs;however,it did countera ct the decay in the viability of the latter after thawing.The tumo r-free hBMECs were thus cultured for up to 2 months and their growth efficiency was assessed befo re and after two periods of cryopreservation.Des pite the thermal stress,the hBMECs remained viable and suitable for re-freezing and storage for several months.This approach increasing in vitro viability of hBMECs opens new perspectives for the use of cryopreserved autologous hBMECs as biomimetic therapeutic tools,offering the potential to avoid additional surgical sampling for each patient.

Targeting brain microvascular endothelial cells: a therapeutic approach to neuroprotection against stroke

Brain microvascular endothelial cells form the interface between nervous tissue and circulating blood, and regulate central nervous system homeostasis. Brain microvascular endothelial cells differ from peripheral endothelial cells with regards expression of specific ion transporters and receptors, and contain fewer fenestrations and pinocytotic vesicles. Brain microvascular endothelial cells also synthesize several factors that influence blood vessel function. This review describes the morphological characteristics and functions of brain microvascular endothelial cells, and summarizes current knowledge regarding changes in brain microvascular endothelial cells during stroke progression and therapies. Future studies should focus on identifying mechanisms underlying such changes and developing possible neuroprotective therapeutic interventions.

In vitro model of the blood-brain barrier established by co-culture of primary cerebral microvascular endothelial and astrocyte cells

Drugs for the treatment and prevention of nervous system diseases must permeate the bloodbrain barrier to take effect.In vitro models of the blood-brain barrier are therefore important in the investigation of drug permeation mechanisms.However,to date,no unified method has been described for establishing a blood-brain barrier model.Here,we modified an in vitro model of the blood-brain barrier by seeding brain microvascular endothelial cells and astrocytes from newborn rats on a polyester Transwell cell culture membrane with 0.4-μm pores,and conducted transepithelial electrical resistance measurements,leakage tests and assays for specific bloodbrain barrier enzymes.We show that the permeability of our model is as low as that of the bloodbrain barrier in vivo.Our model will be a valuable tool in the study of the mechanisms of action of neuroprotective drugs.

Hypoxia inducible factor-1alpha mediates protection of DL-3-n-butylphthalide in brain microvascular endothelial cells against oxygen glucose deprivation-induced injury

Studies have demonstrated that DL-3-n-butylphthalide can significantly alleviate oxygen glucose deprivation-induced injury of human umbilical vein endothelial cells at least partly associated with its enhancement on oxygen glucose deprivation-induced hypoxia inducible factor-1α expression.In this study,we hypothesized that DL-3-n-butylphthalide can protect against oxygen glucose deprivation-induced injury of newborn rat brain microvascular endothelial cells by means of upregulating hypoxia inducible factor-1α expression.MTT assay and Hoechst staining results showed that DL-3-n-butylphthalide protected brain microvascular endothelial cells against oxygen glucose deprivation-induced injury in a dose-dependent manner.Western blot and immunofluorescent staining results further confirmed that the protective effect was related to upregulation of hypoxia inducible factor-1α.Real-time RT-PCR reaction results showed that DL-3-n-butylphthalide reduced apoptosis by inhibiting downregulation of pro-apoptotic gene caspase-3 mRNA expression and upregulation of apoptosis-executive protease bcl-2 mRNA expression;however,DL-3-n-butylphthalide had no protective effects on brain microvascular endothelial cells after knockdown of hypoxia inducible factor-1α by small interfering RNA.These findings suggest that DL-3-n-butylphthalide can protect brain microvascular endothelial cells against oxygen glucose deprivation-induced injury by upregulating bcl-2 expression and downregulating caspase-3 expression though hypoxia inducible factor-1α pathway.

Polylactic Acid Nanoparticles Targeted to Brain Microvascular Endothelial Cells

In this work, blank polylactic acid （PLA） nanoparticles with unstained surface were prepared by the nano-deposition method. On the basis of the preparation, the effect of surface modification on brain microvascular endothelial cells （BMECs） targeting was examined by in vivo experiments and fluorescence microscopy. The results showed that PLA nanoparticles are less toxic than PACA nanoparticles but their BMECs targeting is similar to PACA nanoparticles. The experiments suggest that drugs can he loaded onto the particles and become more stable through adsorption on the surface of PLA nanoparticles with high surface activity. The surface of PLA nanoparticles was obviously modified and the hydrophilicity was increased as well in the presence of non-ionic surfactants on PLA nanoparticles. As a targeting moiety, polysobate 80 （T-80） can facilitate BMECs targeting of PLA nanoparticles.

Protective effect of Cordyceps sinensis extract on rat brain microvascular endothelial cells injured by oxygen-glucose deprivation

Objective:To investigate the protective effect of Cordyceps sinensis extract (CSE)on injury of primary cultured rat brain microvascular endothelial cells (rBMECs) induced by oxygen-glucose deprivation (OGD).Methods:We isolated and cultured primary rBMECs in order to establish an in vitro OGD model.Cellular activity was detected using a cell counting kit to determine the appropriate dosage.The rBMECs were divided into control,model,low-,mid-,and high-dose (5,10,20 μg.mL-1) CSE groups under OGD for 6 hours.CSE was dissolved in cell culture medium to the appropriate concentration,passed through a 0.22 μm sterile filter,and administered for 12 hours before and during OGD.Cellular morphology was observed under a microscope.Lactate dehydrogenase level in cultural supernatant,superoxide dismutase activity,and the content of nitric oxide and malondialdehyde in cells were tested by colorimetric methods.Levels of tumor necrosis factor-α and interleukin-1 beta in cells were determined by enzyme-linked immunosorbent assay.Results:After 12-hour administration of CSE at the concentration of 5,10,20 iμg.mL-1 before and during OGD,compared with the model group,the CSE groups obviously alleviated the damage of rBMECs induced by OGD,inhibited the apoptosis and the necrosis of the cells,and improved cellular morphology of rBMECs.Additionally,compared with the model group,CSE also restrained lactate dehydrogenase leakage in hypoxic cells (P <.01),significantly increased superoxide dismutase activity (P <.05),and reduced the levels of nitric oxide,malondialdehyde,tumor necrosis factor-α,and interleukin-1 beta (P <.05).Conclusion:C.sinensis extract plays a significant role in protecting injured primary cultured rBMECs induced by OGD.The mechanism may be related with the increase of cellular antioxidative capacity and anti-inflammatory effect.

The role of heme-oxygenase-1 in pathogenesis of cerebral malaria in the co-culture model of human brain microvascular endothelial cell and ITG Plasmodium falciparum-infected red blood cells

Objective: To investigate the role of human host heme-oxygenase-1(HO-1) in pathogenesis of cerebral malaria in the in vitro model,Methods: The effect of human host HO-1 [human brain microvascular endothelial cell(HBMEC)] on hemoglobin degradation in the co-culture model of HBMEC and ITG Plasmodium falciparum-infected red cells(i RBC) through measurement of the enzymatic products iron and bilirubin,Results: Following exposure to the HO-1 inducer Co PPIX at all concentrations,the HBMEC cells apoptosis occurred,which could be prominently observed at 15 μM of 3 h exposure,In contrast,there was no significant change in the morphology in the non-exposed i RBC at all concentrations and exposure time,This observation was in agreement with the levels of the enzymatic degradation products iron and bilirubin,of which the highest levels(106.03 and 1 753.54% of baseline level,respectively) were observed at 15 μM vs,20 μM at 3 h vs,24 h exposure,For the effect of the HO-1 inhibitor Zn PPIX,HBMEC cell morphology was mostly unchanged,but significant inhibitory effect on cell apoptosis was seen at 10 μM for the exposure period of 3 h(37.17% of baseline level),The degree of the inhibitory effect as reflected by the level of iron produced was not clearly observed(highest effect at 10 μM and 3 h exposure),Conclusions: Results provide at least in part,insight into the contribution of HO-1 on CM pathogenesis and need to be confirmed in animal model.

Primary culture and identification about brain microvascular endothelial cells of rabbits

Objective:To establish a simple and efficient culture method of primary rabbit brain microvascular endothelial cells,provide important carriers and tool cells for the research of related cerebrovascular diseases.Methods:The cerebral cortexes of rabbits were collected aseptic and inoculated after cutting,passing through cell sieve,bovine serum albumin density gradient centrifugation,typeⅡcollagenase digestion,finally inoculated and cultured.The cultured cells were identified by cell morphological observation and angiogenesis experiment.Results:Under the inverted microscope,the cells were short fusiform or polygonal,and grew in clusters and adhere to the wall.After the cells were densely fused,they would be in a typical monolayer flat,“pebbled"mosaic arrangement.Tube formation test had the ability to form tubes structure.Conclusion:This method can successfully separate and cultivate primary rabbit brain microvascular endothelial cells.

Shuxuetong injection protects cerebral microvascular endothelial cells against oxygen-glucose deprivation reperfusion

Shuxuetong injection composed of leech(Hirudo nipponica Whitman) and earthworm(Pheretima aspergillum) has been used for the clinical treatment of acute stroke for many years in China. However, the precise neuroprotective mechanism of Shuxuetong injection remains poorly understood. Here, cerebral microvascular endothelial cells(bEnd.3) were incubated in glucose-free Dulbecco's modified Eagle's medium containing 95% N_2/5% CO_2 for 6 hours, followed by high-glucose medium containing 95% O_2 and 5% CO_2 for 18 hours to establish an oxygen-glucose deprivation/reperfusion model. This in vitro cell model was administered Shuxuetong injection at 1/32, 1/64, and 1/128 concentrations(diluted 32-, 64-, and 128-times). Cell Counting Kit-8 assay was used to evaluate cell viability. A fluorescence method was used to measure lactate dehydrogenase, and a fluorescence microplate reader used to detect intracellular reactive oxygen species. A fluorescent probe was also used to measure mitochondrial superoxide production. A cell resistance meter was used to measure transepithelial resistance and examine integrity of monolayer cells. The fluorescein isothiocyanate-dextran test was performed to examine blood-brain barrier permeability. Real-time reverse transcription polymerase chain reaction was performed to analyze mRNA expression levels of tumor necrosis factor alpha, interleukin-1β, interleukin-6, and inducible nitric oxide synthase. Western blot assay was performed to analyze expression of caspase-3, intercellular adhesion molecule 1, vascular cell adhesion molecule 1, occludin, vascular endothelial growth factor, cleaved caspase-3, B-cell lymphoma 2, phosphorylated extracellular signal-regulated protein kinase, extracellular signal-regulated protein kinase, nuclear factor-κB p65, I kappa B alpha, phosphorylated I kappa B alpha, I kappa B kinase, phosphorylated I kappa B kinase, claudin-5, and zonula occludens-1. Our results show that Shuxuetong injection increases bEnd.3 cell viability and B-cell lymphoma 2 expression, reduces cleaved caspase-3 expression, inhibits production of reactive oxygen species and mitochondrial superoxide, suppresses expression of tumor necrosis factor alpha, interleukin-1β, interleukin-6, inducible nitric oxide synthase mRNA, intercellular adhesion molecule-1, and vascular cell adhesion molecule-1, markedly increases transepithelial resistance, decreases blood-brain barrier permeability, upregulates claudin-5, occludin, and zonula occludens-1 expression, reduces nuclear factor-κB p65 and vascular endothelial growth factor expression, and reduces I kappa B alpha, extracellular signal-regulated protein kinase 1/2, and I kappa B kinase phosphorylation levels. Overall, these findings suggest that Shuxuetong injection has protective effects on brain microvascular endothelial cells after oxygen-glucose deprivation/reperfusion. Moreover, its protective effect is associated with reduction of mitochondrial superoxide production, inhibition of the inflammatory response, and inhibition of vascular endothelial growth factor, extracellular signal-regulated protein kinase 1/2, and the nuclear factor-κB p65 signaling pathway.

LncRNA SNHG12 ameliorates brain microvascular endothelial cell injury by targeting miR-199a

Long non-coding RNAs regulate brain microvascular endothelial cell death, the inflammatory response and angiogenesis during and after ischemia/reperfusion and oxygen-glucose deprivation/reoxygenation（OGD/R） insults. The long non-coding RNA, SNHG12, is upregulated after ischemia/reperfusion and OGD/R in microvascular endothelial cells of the mouse brain. However, its role in ischemic stroke has not been studied. We hypothesized that SNHG12 positively regulates ischemic stroke, and therefore we investigated its mechanism of action. We established an OGD/R mouse cell model to mimic ischemic stroke by exposing brain microvascular endothelial cells to OGD for 0, 2, 4, 8, 16 or 24 hours and reoxygenation for 4 hours. Quantitative real-time polymerase chain reaction showed that SNHG12 levels in brain microvascular endothelial cells increased with respect to OGD exposure time. Brain microvascular endothelial cells were transfected with pc DNA-control, pc DNA-SNHG12, si-control, or si-SNHG12. After exposure to OGD for 16 hours, these cells were then analyzed by 3-（4,5-dimethyl-2-thiazolyl）-2,5-diphenyl-2-H-tetrazolium bromide, trypan blue exclusion, western blot, and capillary-like tube formation assays. Overexpression of SNHG12 inhibited brain microvascular endothelial cell death and the inflammatory response but promoted angiogenesis after OGD/R, while SNHG12 knockdown had the opposite effects. miR-199a was identified as a target of SNHG12, and SNHG12 overexpression reversed the effect of miR-199a on brain microvascular endothelial cell death, the inflammatory response, and angiogenesis. These findings suggest that SNHG12 suppresses endothelial cell injury induced by OGD/R by targeting miR-199a.

Sustained release of vascular endothelial growth factor A and basic fibroblast growth factor from nanofiber membranes reduces oxygen/glucose deprivation-induced injury to neurovascular units

Upregulation of vascular endothelial growth factor A/basic fibroblast growth factor(VEGFA/b FGF)expression in the penumbra of cerebral ischemia can increase vascular volume,reduce lesion volume,and enhance neural cell proliferation and differentiation,thereby exerting neuroprotective effects.However,the beneficial effects of endogenous VEGFA/b FGF are limited as their expression is only transiently increased.In this study,we generated multilayered nanofiber membranes loaded with VEGFA/b FGF using layer-by-layer self-assembly and electrospinning techniques.We found that a membrane containing 10 layers had an ideal ultrastructure and could efficiently and stably release growth factors for more than 1 month.This 10-layered nanofiber membrane promoted brain microvascular endothelial cell tube formation and proliferation,inhibited neuronal apoptosis,upregulated the expression of tight junction proteins,and improved the viability of various cellular components of neurovascular units under conditions of oxygen/glucose deprivation.Furthermore,this nanofiber membrane decreased the expression of Janus kinase-2/signal transducer and activator of transcription-3(JAK2/STAT3),Bax/Bcl-2,and cleaved caspase-3.Therefore,this nanofiber membrane exhibits a neuroprotective effect on oxygen/glucose-deprived neurovascular units by inhibiting the JAK2/STAT3 pathway.

Integrin binding peptides facilitate growth and interconnected vascular-like network formation of rat primary cortical vascular endothelial cells in vitro

Neovascularization and angiogenesis in the brain are important physiological processes for normal brain development and repair/regeneration following insults. Integrins are cell surface adhesion receptors mediating important function of cells such as survival, growth and development during tissue organization, differentiation and organogenesis. In this study, we used an integrin-binding array platform to identify the important types of integrins and their binding peptides that facilitate adhesion, growth, development, and vascular-like network formation of rat primary brain microvascular endothelial cells. Brain microvascular endothelial cells were isolated from rat brain on post-natal day 7. Cells were cultured in a custom-designed integrin array system containing short synthetic peptides binding to 16 types of integrins commonly expressed on cells in vertebrates. After 7 days of culture, the brain microvascular endothelial cells were processed for immunostaining with markers for endothelial cells including von Willibrand factor and platelet endothelial cell adhesion molecule. 5-Bromo-2′-dexoyuridine was added to the culture at 48 hours prior to fixation to assess cell proliferation. Among 16 integrins tested, we found that α5β1, αvβ5 and αvβ8 greatly promoted proliferation of endothelial cells in culture. To investigate the effect of integrin-binding peptides in promoting neovascularization and angiogenesis, the binding peptides to the above three types of integrins were immobilized to our custom-designed hydrogel in three-dimensional(3 D) culture of brain microvascular endothelial cells with the addition of vascular endothelial growth factor. Following a 7-day 3 D culture, the culture was fixed and processed for double labeling of phalloidin with von Willibrand factor or platelet endothelial cell adhesion molecule and assessed under confocal microscopy. In the 3 D culture in hydrogels conjugated with the integrin-binding peptide, brain microvascular endothelial cells formed interconnected vascular-like network with clearly discernable lumens, which is reminiscent of brain microvascular network in vivo. With the novel integrin-binding array system, we identified the specific types of integrins on brain microvascular endothelial cells that mediate cell adhesion and growth followed by functionalizing a 3 D hydrogel culture system using the binding peptides that specifically bind to the identified integrins, leading to robust growth and lumenized microvascular-like network formation of brain microvascular endothelial cells in 3 D culture. This technology can be used for in vitro and in vivo vascularization of transplants or brain lesions to promote brain tissue regeneration following neurological insults.

树鼩脑微血管内皮永生化细胞系的建立及最适D-半乳糖浓度诱导BMECs衰老细胞模型的探讨

目的建立树鼩永生化脑微血管内皮细胞(brain microvascular endothelial cells,BMECs),明确D-半乳糖对BMECs衰老的影响,探索其潜在机制。方法用携带SV40T基因的慢病毒转染BMECs,传至50代后进行形态观察、生长曲线测定以及免疫荧光和核型鉴定;再用不同浓度D-半乳糖(D-galactose,D-gal)诱导BMECs,通过细胞增殖实验确定最适诱导条件,用衰老相关β半乳糖苷酶染色分析细胞衰老情况,Western Blot检测衰老相关蛋白p53的表达水平,超氧化物歧化酶和脂质氧化检测试剂盒检测细胞内氧化应激水平。结果永生化的细胞生长状态较好,不同代次的细胞形态一致,单个细胞呈短梭形或多角形,整体呈典型的铺路石状;细胞生长曲线显示细胞数量在第2~5天时处于对数生长期,在第6天时达到高峰,之后缓慢增长进入平台期;免疫荧光显示该细胞特异蛋白vWF和CD31及永生化基因SV40T为阳性;细胞核型结果显示永生化细胞染色体数目与滇西亚种树鼩的染色体数量相符;D-gal诱导BMECs抑制细胞增殖,有时间和浓度依赖性;实验组,即浓度为10 g/L的D-gal诱导48 h的BMECs,β-半乳糖苷酶染色阳性明显增多、衰老相关蛋白p53显著增多、细胞内SOD酶活性降低和MDA含量增多。结论成功构建树鼩永生化脑微血管内皮细胞系,10 g/L的D-gal是建立永生化BMECs衰老模型的适合浓度,D-gal在体外促进细胞衰老可能是通过促进氧化应激水平、抑制细胞增殖来实现的。

常压高浓度氧对新生大鼠脑微血管内皮细胞损伤与Nrf2/HO-1信号通路的影响分析

目的探究常压高浓度氧(NBO)对新生大鼠脑微血管内皮细胞损伤及核因子E2相关因子2/血红素氧合酶-1(Nrf2/HO-1)信号通路的影响。方法取新生SD大鼠45只,采用随机数字表法分为常氧组、NBO组和NBO+Nrf2激活剂组,每组各15只。常氧组大鼠置于普通空气(21%氧气)中饲养,NBO组和NBO+Nrf2激活剂组大鼠置于90%常压氧气饲养,NBO+Nrf2激活剂组每日灌胃5 mg/kg Nrf2激动剂莱菔硫烷。测定脑组织伊文思蓝(EB)含量,采用酶联免疫法检测血管内皮生长因子(VEGF)和基质金属蛋白酶9(MMP-9)含量,干湿重法检测脑组织含水量,HE染色和TUNEL染色观察脑组织病理变化,蛋白质印迹法检测海马组织Nrf2/HO-1信号通路蛋白表达,水迷宫检测大鼠认知功能。结果与常氧组比较,NBO组脑组织EB、VEGF、MMP-9含量及脑组织含水量升高,差异均有统计学意义(P<0.05);与NBO组比较,NBO+Nrf2激活剂组脑组织EB、VEGF、MMP-9含量及脑组织含水量降低,差异均有统计学意义(P<0.05)。病理染色结果显示,常氧组大鼠神经细胞形态及结构完整,未见明显病理变化和细胞凋亡;NBO组神经细胞形态及结构不规则,出现明显的水肿和空泡,并伴有大量的凋亡细胞;NBO+Nrf2激活剂组脑组织病理损伤较NBO组明显减轻。与常氧组比较,NBO组脑组织Nrf2、HO-1蛋白相对表达量降低,差异均有统计学意义(P<0.05);与NBO组比较,NBO+Nrf2激活剂组Nrf2、HO-1蛋白相对表达量升高,差异均有统计学意义(P<0.05)。与常氧组比较,NBO组第2~4天逃避潜伏期延长,穿越平台次数减少,差异均有统计学意义(P<0.05);与NBO组比较,NBO+Nrf2激活剂组第2~4天逃避潜伏期缩短,穿越平台次数增多,差异均有统计学意义(P<0.05)。结论NBO可诱导新生大鼠脑微血管内皮细胞损伤,导致远期认知功能障碍,可能与下调Nrf2/HO-1信号通路表达有关。

天麻素与薯蓣皂苷元配伍对大鼠缺氧损伤脑微血管内皮细胞的保护作用

目的探讨天麻素(Gas)、薯蓣皂苷元(Dio)及其组合物(GDC)对大鼠缺氧损伤脑微血管内皮细胞(BMECs)的保护作用和对脑微血管新生的影响及其作用机制。方法将BMECs分为5组:正常对照组,模型对照组,Gas组(1、2、4、8、16、32μmol·L^(-1)),Dio组(0.25、0.5、1、2、4、8μmol·L^(-1)),GDC组(Gas和Dio浓度分别为1和0.25、2和0.5、4和1、8和2、16和4、32和8μmol·L^(-1))。分组给药12 h后,对模型对照组、Gas组、Dio组和GDC组通过氧糖剥夺法建立BMECs缺氧模型。检测乳酸脱氢酶(LDH)漏出率、白细胞介素1β(IL-1β)含量、超氧化物歧化酶(SOD)活力、丙二醛(MDA)浓度;观察Hoechst 33258、FITC-Annexin V/PI染色,采用Transwell小室实验、细胞划痕实验和小管形成实验,考察Gas、Dio及GDC对缺氧损伤BMECs的保护作用及促进血管新生作用。进一步利用网络药理学和分子对接方法研究GDC抗脑缺血的作用机制。结果Gas、Dio以2、0.5μmol·L^(-1)组合时,可显著提高缺氧损伤BMECs细胞活力(P<0.05),促进细胞增殖;与模型对照组比较,Gas组LDH漏出率降低(P<0.05);Gas组、Dio组与GDC组IL-1β含量均显著下降(均P<0.05),Gas组、GDC组SOD活力升高(P<0.05),Gas组、Dio组以及GDC组凋亡小体减少。GDC可促进BMECs缺氧模型的增殖、侵袭、迁移以及小管形成,表明其在细胞水平上一定程度促进血管新生。网络药理学研究发现,Gas与半胱天冬酶3(CASP3)、过氧化物酶体增生激活受体γ(PPARG)、凝血因子Ⅱ(F2)、基质金属蛋白酶-9(MMP-9)、丝氨酸苏氨酸蛋白激酶(Akt)1蛋白具有良好的结合活性,Dio与内皮一氧化氮合成酶(NOS3)、KDR蛋白具有良好的结合活性,Gas、Dio可能主要通过血管内皮生长因子(VEGF)信号通路、丝裂原活化蛋白激酶(MAPK)信号通路、磷酯酰肌醇3-激酶(PI3K)-Akt信号通路以及缺氧诱导因子-1(HIF-1)信号通路调控脑缺血后血管新生。结论Gas、Dio及GDC具有抗缺氧损伤作用并可促进缺氧损伤后血管新生,作用机制可能与其作用于Akt1、NOS3、VEGFR2等蛋白,调控VEGF/Akt/MAPK等信号通路促进血管新生有关。

六味地黄丸介导RAGE抑制MMP-2/MMP-9对Aβ_(1-40)损伤bEnd.3细胞紧密连接蛋白的影响

目的探讨六味地黄丸对β淀粉样蛋白1-40(Aβ_(1-40))损伤的小鼠脑微血管内皮细胞(bEnd.3)的保护作用及其机制。方法采用CCK8法检测Aβ_(1-40)和六味地黄丸含药血清(MSLDP)对细胞活性的影响,筛选合适的作用浓度。将bEnd.3细胞分为对照组、Aβ_(1-40)组、MSLDP+Aβ_(1-40)组和MSLDP组,采用Western blot检测低密度脂蛋白相关蛋白1(LRP1)、晚期糖基化终末产物受体(RAGE)、基质金属蛋白酶2(MMP-2)、MMP-9、闭锁小带蛋白-1(ZO-1)、脑源性神经营养因子(BDNF)蛋白表达,免疫荧光检测LRP1、RAGE、ZO-1表达;再将bEnd.3细胞分为对照组、Aβ_(1-40)组、FPS-ZM1(RAGE抑制剂)+Aβ_(1-40)组和FPS-ZM1+Aβ_(1-40)+MSLDP组,Western blot检测RAGE、MMP-9、MMP-2、ZO-1蛋白表达。结果Aβ_(1-40)呈剂量依赖性降低bEnd.3细胞活性(P<0.01),MSLDP对Aβ_(1-40)损伤的细胞活性具有保护作用(P<0.05,P<0.01),因此选择10μmol/L Aβ_(1-40)和10%MSLDP进行后续实验。与对照组比较,Aβ_(1-40)组RAGE、MMP-2、MMP-9蛋白表达升高(P<0.01),LRP1、ZO-1、BDNF蛋白表达降低(P<0.05,P<0.01),并且LRP1、ZO-1荧光强度降低(P<0.01),RAGE荧光增强(P<0.01);与Aβ_(1-40)组比较,MSLDP组RAGE、MMP-2、MMP-9蛋白表达和RAGE荧光强度降低(P<0.05,P<0.01),而LRP1、ZO-1、BDNF蛋白表达和LRP1、ZO-1荧光强度升高(P<0.05,P<0.01)。与Aβ_(1-40)组比较,Aβ_(1-40)+FPS-ZM1组MMP-2、MMP9、RAGE蛋白表达降低(P<0.05,P<0.01),ZO-1蛋白表达升高(P<0.05);Aβ_(1-40)+FPS-ZM1+MSLDP组MMP-2、MMP9、RAGE蛋白表达降低(P<0.01),ZO-1蛋白表达升高(P<0.01),FPS-ZM1和MSLDP联合使用的效果更佳。结论六味地黄丸能够保护Aβ_(1-40)损伤的脑微血管内皮的细胞紧密连接,减轻血脑屏障障碍,保护神经血管单元防治阿尔茨海默病,可能通过调节RAGE途径抑制MMP-2/MMP-9途径实现。

映山红花总黄酮促进大鼠脑血管内皮细胞体外形成血管作用及与VEGFR_(2)和神经源性H_(2)S的关系

目的探讨映山红花总黄酮(total flavones of rhododendra,TFR)促大鼠脑血管内皮细胞体外形成血管作用及与VEGFR_(2)和神经源性硫化氢(H_(2)S)的关系。方法采用大鼠脑血管内皮细胞单独培养及和与海马神经元共培养,分别采用不同的实验方法检测细胞增殖、迁移、成管及H_(2)S含量和钙离子荧光强度,包括CCK-8法、细胞划痕法、Transwell法、基质胶成管、H_(2)S试剂盒及钙离子荧光探针法。结果在单独培养的大鼠脑血管内皮细胞上,H_(2)S供体NaHS(200μmol·L^(-1))和TFR(90、270、810 mg·L^(-1))对大鼠脑血管内皮细胞的增殖、迁移、成管及[Ca^(2+)]i荧光强度都有明显的促进作用。而VEGFR_(2)阻断剂SU5416(10μmol·L^(-1))可抑制TFR的促进内皮细胞增殖、迁移和形成血管及[Ca^(2+)]i荧光强度;在与海马神经元共培养的大鼠脑血管内皮细胞上,TFR显著地升高共培养中H_(2)S含量,并被CBS抑制剂AOAA(200μmol·L^(-1))抑制。与此同时,TFR明显地促进共培养中大鼠脑血管内皮细胞的形成血管作用,并可被AOAA和VEGFR_(2)阻断剂SU5416显著地抑制。结论TFR在体外可通过VEGFR_(2)升高[Ca^(2+)]i来促进脑血管内皮细胞形成血管,并可通过诱导神经元中CBS生成H_(2)S作用于大鼠脑血管内皮细胞的VEGFR_(2)来促进血管形成。

基于JAK2/STAT3通路探讨活血荣络方对OGD/R后BMEC的干预作用及机制

目的探讨活血荣络方激活Janus酪氨酸激酶2/信号转导和转录激活剂3(Janus kinase 2/signal transducer and activator of transcription 3,JAK2/STAT3)通路对氧糖剥夺/复氧(oxygen-glucose deprivation/reperfusion,OGD/R)后脑微血管内皮细胞(brain microvascular endothelial cell,BMEC)的干预作用和机制。方法培养大鼠BMEC(bEnd.3细胞),建立OGD/R模型;将细胞随机分为正常组(10%空白血清)、模型组(10%空白血清)、活血荣络方组(10%活血荣络方含药血清)、丁苯酞组(10%丁苯酞含药血清)、Stattic组(10%空白血清+10μmol/mL Stattic)、联用组(10%活血荣络方含药血清+10μmol/mL Stattic),并分别给予相应的药物干预24 h。采用CCK-8法检测活血荣络方对OGD/R后bEnd.3细胞活性的影响;采用划痕实验和Transwell迁移实验分别检测活血荣络方对OGD/R后bEnd.3细胞划痕愈合和细胞迁移的影响;采用Western blot法检测bEnd.3细胞中JAK2、p-JAK2、STAT3、p-STAT3、血管内皮细胞生长因子A(vascular endothelial growth factor A,VEGFA)蛋白表达水平。结果与正常组比较,模型组bEnd.3细胞存活率、细胞划痕愈合率、细胞迁移数显著降低(P<0.01),JAK2、p-JAK2、STAT3、p-STAT3、VEGFA的表达量升高(P<0.05或P<0.01);与模型组比较,活血荣络方组bEnd.3细胞的存活率、细胞划痕愈合率、细胞迁移数显著升高(P<0.01),JAK2、p-JAK2、p-STAT3、STAT3、VEGFA的表达量升高(P<0.05或P<0.01);与Stattic组比较,联用组bEnd.3细胞的存活率、细胞划痕愈合率、细胞迁移数显著升高(P<0.05或P<0.01),STAT3、VEGFA的表达量升高(P<0.05)。结论活血荣络方可能激活JAK2/STAT3信号通路并诱导内皮细胞的增殖、迁移和存活,激活VEGFA表达并减轻脑缺血再灌注损伤,具有神经保护作用。

丙泊酚减弱CCL4诱导脑微血管内皮细胞促炎和细胞毒作用机制研究

目的 探讨趋化因子配体4(CCL4)诱导脑微血管内皮细胞炎症和细胞毒作用,以及丙泊酚对CCL4诱导效应的拮抗作用。方法 将体外永生化人脑微血管内皮细胞hCMEC/D3分为为对照组、CCL4组、丙泊酚+CCL4组细胞。采用CCK-8试验检测各组细胞增殖活力,细胞克隆形成实验分析细胞克隆形成能力,流式细胞术Annexin V/PI双染检测细胞凋亡情况。采用实时荧光定量PCR(qPCR)检测细胞细胞炎症基因、血栓形成相关基因的表达情况,酶活性检测试剂盒检测环氧化酶-2(COX-2)及凝血酶活性。结果 与对照组细胞比较,CCL4组细胞增殖活力显著减弱,细胞克隆形成能力减低,凋亡细胞增加,差异有统计学意义(P<0.001);与CCL4组,丙泊酚+CCL4组细胞增殖活力显著上调,细胞克隆形成能力增加,凋亡细胞减少,差异有统计学意义(P<0.001)。qPCR检测结果显示,与对照组比较,CCL4组炎症相关基因白细胞介素(IL)-1β、IL-6、IL-8、核转录因子κB(NF-κB)、肿瘤坏死因子α(TNF-α)及COX-2基因表达上调,血栓形成基因Thrombin、Factor 8、VWF及TXA表达增加,COX-2酶及凝血酶活性增加,差异有统计学意义(P<0.001)。丙泊酚可明显抑制CCL4对hCMEC/D3的炎症相关基因及血栓形成基因的促进表达作用,以及CCL4对hCMEC/D3的COX2酶及凝血酶活性。结论 丙泊酚可减轻CCL4对脑微血管内皮细胞的细胞毒作用,并拮抗其促炎和促血栓形成基因表达。