Exploring the mechanism of icariin in regulat⁃ing cardiac microvascular endothelial cells based on network pharmacology,molecular docking and in vitro experiments

OBJECTIVE To investigate the regulatory effects of icariin(ICA)on cardiac micro⁃vascular endothelial cells(CMEC)after oxygenglucose deprivation reperfusion(OGD/R)injury.METHODS CMEC were subjected to OGD/R treatment to construct a myocardial ischemiareperfusion model,and were divided into normal,model,low(10μmol·L^(-1)),medium(20μmol·L^(-1))and high(40μmol·L^(-1))ICA group,and high ICA+inhibitor group(40μmol·L^(-1)+20 nmol·L^(-1)).CCK-8 assay was used to assess the protective ability of ICA against CMEC,and cell migration assay and tube-formation assay were used to detect the migration and generation ability of CMEC.The TCMSP database,Swiss-Target database and literature mining methods were used to col⁃lect ICA-related targets,the GeneCards data⁃base was used to collect target genes related to myocardial ischemia/reperfusion,and Cytoscape 3.8.0 software was used to construct a"drug-tar⁃get-disease"network.The potential targets were imported into STRING 11.5 database to obtain the PPI network.GO and KEGG enrichment analyses were performed on the potential targets using the DAVID database.Molecular docking was performed using AutoDock-vina 1.1.2 soft⁃ware.Western blot detected the expression of related proteins.RESULTS After CMEC was subjected to OGD/R treatment,ICA had a protec⁃tive effect at 10^(-1)60μmol·L^(-1);the results of the cell migration assay showed that each group of ICA could promote the migratory effect of CMEC(P<0.01,P<0.01);and the results of tube-for⁃mation assay showed that each group of ICA could significantly promote the generation of branches(P<0.01)and the capillary length exten⁃sion(P<0.05).Network pharmacology collected a total of 23 ICA action targets,1500 disease tar⁃gets and 12 key targets.GO function enrichment analysis found 85 results.KEGG pathway enrich⁃ment analysis found 53 results,involving AGERAGE signaling pathway,sphingolipid signaling pathway and VEGF signaling pathway.Molecu⁃lar docking results showed that ICA had better binding with core targets PRKCB,PRKCA and PTGS2.Western blot results showed that ICA could regulate the expression of PRKCB,PRKCA and PTGS2 proteins.The results of cell migra⁃tion assay,tube-formation assay and protein expression were reversed after addition of PKC inhibitor.CONCLUSION The potential mecha⁃nism of action of ICA against myocardial isch⁃emia-reperfusion injury may be related to the reg⁃ulation of processes such as CMEC migration and angiogenesis,and it functions through the key target gene PKC.

Down-regulation of histone deacetylase 7 reduces biological activities of retinal microvascular endothelial cells under high glucose condition and related mechanism

AIM:To investigate the expression and effect of histone deacetylase 7(HDAC7)in human retinal microvascular endothelial cells(HRMECs)under high glucose condition and related mechanism,and the expression of HDAC7 in the retinal tissue in diabetic rats.METHODS:The expression of HDAC7 in HRMECs under high glucose and the retinal tissue from normal or diabetic rats were detected with immunohistochemistry and Western blot.LV-shHDAC7 HRMECs were used to study the effect of HDAC7 on cell activities.Cell count kit-8(CCK-8),5-ethynyl2’-deoxyuridine(EdU),flow cytometry,scratch test,Transwell test and tube formation assay were used to examine the ability of cell proliferation,migration,and angiogenesis.Finally,a preliminary exploration of its mechanism was performed by Western blot.RESULTS:The expression of HDAC7 was both upregulated in retinal tissues of diabetic rats and high glucosetreated HRMECs.Down-regulation of HDAC7 expression significantly reduced the ability of proliferation,migration,and tube formation,and reversed the high glucose-induced high expression of CDK1/Cyclin B1 and vascular endothelial growth factor in high glucose-treated HRMECs.CONCLUSION:High glucose can up-regulate the expression of HDAC7 in HRMECs.Down-regulation of HDAC7 can inhibit HRMECs activities.HDAC7 is proposed to be involved in pathogenesis of diabetic retinopathy and a therapeutic target.

Glucagon-like peptide-1 protects against cardiac microvascular endothelial cells injured by high glucose

Objective:To investigate the protective effect of glucagon-like peptid-1(GLP-l) against cardiac microvascular endothelial cell(GTFCs) injured by high glucose.Methods:CMECs were isolated and cultured.Superoxide assay kit and dihydroethidine(DHE) staining were used to assess oxidative stress.TENEL staining and caspase 3 expression were used to assess the apoptosis of CMECs.H89 was used to inhibit eAMP/PKA pathway:fasudil was used to inhibit Rho/ROCK pathway.The protein expressions of Rho.ROCK uere examined by Western blol analysis.lesults:High glucose increased the production of ROS.the activity of NADPH.the apoptosis rate and the expression level of Rho/ROCK in CMECs.while GLP- 1 decreased high glucose-induced ROS production.the NADPH activity and the apoptosis rate and the expression level of Rho/ROCK in CMECs,the difference were statistically significant(P<0.05).Conclusions:GLP-1 could protect the cardiac microvessels against oxidative stress and apoptosis.The protective effects of GLP-1 are dependent on downstream inhibition of Rho through a cAMP/PKA-dependent manner,resulting in a subsequent decrease in the expression of NADPH oxidase.

Flavin-Containing Monooxygenase (FMO) Protein Expression and Its Activity in Rat Brain Microvascular Endothelial Cells

The aim of this study was to examine whether flavin-containing monooxygenase (FMO) protein was expressed in cultured rat brain microvascular endothelial cells (BMECs), which constitute the blood-brain barrier (BBB), and whether N-oxide from the tertiary amine, d-chlorpheniramine, was formed by FMO in rat BMECs. BMECs were isolated and cultured from the brains of three-week-old male Wistar rats. The expression of FMO1, FMO2 and FMO5 proteins was confirmed in rat BMECs by western blotting analysis using polyclonal anti-FMO antibodies, but FMO3 and FMO4 proteins were not found in the rat BBB. Moreover, N-oxide of d-chlorpheniramine was formed in rat BMECs. The intrinsic clearance value for N-oxidation at pH 8.4 was higher than that at pH 7.4. Inhibition of N-oxide formation by methimazole was found to be the best model of competitive inhibition yielding an apparent Ki value of 0.53 μmol/L, suggesting that N-oxidation was catalyzed by FMOs in rat BMECs. Although FMO activity in rat BMECs was lower than that in SD rat normal hepatocytes (rtNHeps), we suggest that rat BMECs enzymes can convert substrates of exogenous origin for detoxification, indicating that BMECs are an important barrier for metabolic products besides hepatic cells.

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.

Trimethylamine N-oxide aggravates vascular permeability and endothelial cell dysfunction under diabetic condition:in vitro and in vivo study

AIM:To provide the direct evidence for the crucial role of trimethylamine N-oxide(TMAO)in vascular permeability and endothelial cell dysfunction under diabetic condition.METHODS:The role of TMAO on the in vitro biological effect of human retinal microvascular endothelial cells(HRMEC)under high glucose conditions was tested by a cell counting kit,wound healing,a transwell and a tube formation assay.The inflammation-related gene expression affected by TMAO was tested by real-time polymerase chain reaction(RT-PCR).The expression of the cell junction was measured by Western blotting(WB)and immunofluorescence staining.In addition,two groups of rat models,diabetic and non-diabetic,were fed with normal or 0.1%TMAO for 16wk,and their plasma levels of TMAO,vascular endothelial growth factor(VEGF),interleukin(IL)-6 and tumor necrosis factor(TNF)-αwere tested.The vascular permeability of rat retinas was measured using FITC-Dextran,and the expression of zonula occludens(ZO)-1 and claudin-5 in rat retinas was detected by WB or immunofluorescence staining.RESULTS:TMAO administration significantly increased the cell proliferation,migration,and tube formation of primary HRMEC either in normal or high-glucose conditions.RT-PCR showed elevated inflammation-related gene expression of HRMEC under TMAO stimulation,while WB or immunofluorescence staining indicated decreased cell junction ZO-1 and occludin expression after high-glucose and TMAO treatment.Diabetic rats showed higher plasma levels of TMAO as well as retinal vascular leakage,which were even higher in TMAO-feeding diabetic rats.Furthermore,TMAO administration increased the rat plasma levels of VEGF,IL-6 and TNF-αwhile decreasing the retinal expression levels of ZO-1 and claudin-5.CONCLUSION:TMAO enhances the proliferation,migration,and tube formation of HRMEC,as well as destroys their vascular integrity and tight connection.It also regulates the expression of VEGF,IL-6,and TNF-α.

Simple, Reliable Isolation, Purification and Cultivation of Murine Skeletal Muscle Microvascular Endothelial Cells

Objectives: Microvascular dysfunction in skeletal muscle is involved in metabolic and vascular diseases. Microvascular endothelial cells (MEC) are poorly characterized in the progression of associated diseases in part due to lack of availability of MEC from various animal models. The objective was to provide a fast, simple, and efficient method to isolate murine MEC derived from skeletal muscle. Methods: Dissected abdominal skeletal muscles from C57BL/6J mice at 8 - 12 weeks of age were enzymatically dissociated. MEC were isolated using a modified two-step Dynabeads™-based purification method. With a combination of Dynabeads™ - Griffonia simplicifolia lectin-I and Dynabeads™ - monoclonal antibody against CD31/PECAM-1, MEC were isolated and purified twice followed by cultivation. Results: Isolated and purified cells were viable and cultured. MEC were characterized by using immunofluorescence to identify CD31/PECAM-1, an EC marker, and two specific functional assays, which include a capillary-like tube formation and the uptake of Dil-Ac-LDL. The purity of isolated cell populations from skeletal muscle microvessels, which was assessed by flow cytometry, was 88.02% ± 2.99% (n = 6). Conclusions: This method is simple, fast, and highly reproducible for isolating MEC from murine skeletal muscle. The method will enable us to obtain primary cultured MEC from various genetic or diseased murine models, contributing to insightful knowledge of diseases associated with the dysfunction of microvessels.

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。

Gene Expression Profiling of the Proliferative Effect of Periplocin on Mouse Cardiac Microvascular Endothelial Cells

Objective： Periplocin is an active digitalis-like component from Cortex Periplocae, which has been widely used in the treatment of heart diseases in China for many years. According to the recommendations on the cardiovascular effect of periplocin from in vivo experiments, subsequent in vitro experiments are greatly needed for the global assessment of periplocin. The objective of this study is to investigate the cell proliferation effect and the mechanism of periplocin on endothelial cells. Methods： The proliferative activity of periplocin （0.4, 2, 10, 50, 250 pmol/L; 6, 12, 24, 48, 72 h） was investigated by a comparison with the well-reported cardiac glycoside, ouabain, on mouse cardiac microvascular endothelial cells （CMEC）. 3-（4,5-dimethylthiazolyl）- 2,5-diphenyltetrazolium bromide （MTT）, lactate dehydrogenase （LDH） and 5-bromo-2-deoxyuridine （BrdU） assays were used to evaluate cell proliferation and viability. Subsequently, cDNA microarray experiments were performed on periplocin- （50 pmol/L） and ouabain- （50 pmol/L） treated cells, and data was analyzed by ArrayTrack software. Results： Periplocin could increase cell viability to a level lower than ouabain in the MIF analysis, but decrease LDH release simultaneously. The BrdU incorporation assay showed an increase in cell proliferation with 2-50 μmol/L periplocin. Genes related to protein serine/threonine kinase were the most significantly enriched in the 160 genes identified in periplocin versus the control. In the 165 genes regulated by periplocin versus ouabain, GTP-binding was the most altered term. Conclusions： The results demonstrated the proliferation action of periplocin on CMEC. Meanwhile, its lower cytotoxicity compared to ouabain provides a new insight into the treatment of heart failure.

脂肪间充质干细胞外囊泡通过增加LC3B表达对人微血管内皮细胞损伤的影响

目的:探讨低氧微环境诱导下脂肪间充质干细胞(ADSCs)外囊泡(Evs)通过增加微管相关蛋白轻链3B(LC3B)表达对人微血管内皮细胞损伤的保护作用。方法:分离大鼠ADSCs,并通过成骨、成脂分化和细胞表面标志物的表达进行鉴定。利用常氧(21%O2)和低氧(1%O2)条件分别获得常氧Evs和低氧Evs,通过形态和表面标志物的表达进行鉴定。构建心肌微血管内皮细胞(CMECs)细胞氧糖剥夺/再灌注(OGD/R)模型,并将CMECs分为对照组(Control组)、氧糖剥夺/再灌注组(OGD/R组)、常氧Evs组(N-Evs组,给予常氧Evs培养24 h)、低氧Evs组(H-Evs组,给予低氧Evs培养24 h)、低氧Evs+自噬抑制剂组(H-Evs+3-MA组,给予低氧Evs和3-MA 5 mmol/L培养24 h)。采用细胞计数试剂盒(CCK-8)法、5-乙炔基-2-脱氧尿嘧啶核苷(EdU)染色、划痕实验、Transwell实验、管腔形成实验和透射电镜分别检测CMECs增殖、迁移、侵袭、血管形成和自噬能力;采用酶联免疫吸附法(Western Blot)检测增殖细胞核抗原(PCNA)、Ki67、基质金属蛋白酶(MMP)-2/MMP-9、缺氧诱导因子-1α(HIF-1α)、血管内皮生长因子(VEGF)、LC3B、重组人自噬效应蛋白1(Beclin1)蛋白表达。结果:与Control组比较,OGD/R组CMECs增殖、迁移、侵袭、血管形成、自噬能力减弱(P<0.05),PCNA、Ki67、MMP-2/MMP-9、HIF-1α、VEGF、LC3B-Ⅱ/Ⅰ、Beclin1表达减少(P<0.05)。与OGD/R组比较,N-Evs组和H-Evs组CMECs增殖、迁移、侵袭、血管形成、自噬能力增强(P<0.05),PCNA、Ki67、MMP-2/MMP-9、HIF-1α、VEGF、LC3B-Ⅱ/Ⅰ、Beclin1表达增加(P<0.05),且H-Evs组优于N-Evs组(P<0.05)。与H-Evs组比较,H-Evs+3-MA组CMECs增殖、迁移、侵袭、血管形成、自噬能力减弱(P<0.05),PCNA、Ki67、MMP-2/MMP-9、HIF-1α、VEGF、LC3B-Ⅱ/Ⅰ、Beclin1表达减少(P<0.05)。结论:低氧微环境诱导下的ADSCs-Evs通过增加LC3B表达可促进OGD/R损伤CMECs的增殖、迁移、侵袭、血管形成和自噬能力。

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。

舒洛地特激活AMPK/SIRT1通路减轻高糖诱导的大鼠心肌微血管内皮细胞损伤

目的:探讨舒洛地特(SDX)减轻高糖(HG)诱导的大鼠心肌微血管内皮细胞(CMEC)氧化应激和凋亡的作用及其机制。方法:分离培养大鼠CMEC,随机分为对照组、HG组、HG+SDX组。CCK-8法检测细胞存活率。利用DCFH-DA作为荧光探针,测定各组DCF荧光强度以判定细胞内活性氧(ROS)水平。比较各组细胞上清液中超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量。采用流式细胞术和TUNEL法检测细胞凋亡率,western blotting法检测AMPK、磷酸化(p-)AMPK、SIRT1蛋白表达。结果:与对照组相比,HG组CMEC细胞存活率降低,细胞上清液中MDA含量增高,SOD活性降低,ROS水平和细胞凋亡率升高,p-AMPK、SIRT1蛋白表达水平下降(均P<0.05)。与HG组比较,HG+SDX组CMEC的细胞存活率显著提升,MDA、ROS生成减少,SOD活性升高,CMEC凋亡率下降,p-AMPK、SIRT1蛋白表达水平升高(均P<0.05)。结论:SDX可能通过激活AMPK/SIRT1信号通路,减轻HG诱导的CMEC的氧化应激及细胞凋亡,从而发挥心血管保护作用。

长链非编码RNA-MEG3在人心脏微血管内皮细胞缺氧损伤中的作用

目的研究长链非编码RNA-MEG3在人心脏微血管内皮细胞(HCMEC)缺氧损伤中的作用。方法将HCMEC分为对照组、缺氧/复氧(H/R)组及缺氧/复氧联合MEG3敲减(H/R+siMEG3)组。荧光定量PCR检测MEG3及炎性因子的表达情况[白介素1β(IL-β)、IL-6、IL-8、IL-10、肿瘤坏死因子(TNF-α)];CCK-8检测HCMEC细胞的增殖活性;流式细胞术分析细胞凋亡情况;Western blotting检测PI3K/AKT/eNOS信号通路表达变化,ELISA检测一氧化氮(NO)、超氧化物歧化酶(SOD)、血管内皮生长因子(VEGF)和活性氧(ROS)表达水平。结果利用qPCR检测对照组及H/R组细胞MEG3表达,结果发现:H/R组MEG3相对表达倍数[(6.87±0.239)倍]较对照组MEG3表达倍数(1.00±0.026)倍显著升高(n=3,t=42.32,P<0.0001),提示MEG3可能在心脏微血管内皮细胞IRI中起到重要作用。H/R组细胞与对照组比较,细胞增殖活性显著减弱(P<0.01);而H/R+siMEG3组与H/R组比较,细胞增殖活性进步受到抑制(P<0.01)。H/R组较对照组PI3K、AKT及eNOS磷酸化水平显著减低,而H/R+siMEG3组细胞较H/R组磷酸化水平更低(P<0.05)。H/R组与对照组比较,NO、SOD及VEGF显著减低,而ROS水平升高(P<0.05);而H/R+siMEG3组与H/R组比较,NO、SOD及VEGF水平进步下降,ROS升高显著。利用qPCR检测各处理组细胞相关炎症基因表达,结果发现:H/R组较对照组基因表达显著升高(P<0.05);H/R+SiMEG3组较H/R组基因表达进一步升高(P<0.01)。结论长链非编码RNA-MEG3在心脏微血管内皮细胞H/R损伤过程中起到重要保护作用,靶向提升MEG3水平有望成为减缓心脏微血管IRI的潜在治疗靶点。

两种方法建立肝癌皮下瘤块模型的比较

目的:采用注射Walker-256肿瘤细胞的方法建立Wistar鼠和BALB/c裸鼠皮下瘤块模型。方法:抽取含Walker-256肿瘤细胞的BALB/c裸鼠腹水,进行离心洗涤,将洗涤液分别接种于Wistar鼠及BALB/c裸鼠腹股沟区皮下形成皮下瘤块。观察并比较两种不同实验鼠所建立的皮下瘤块模型成瘤率及瘤体生长速度。实验结束后,采用免疫组织化学法检测皮下瘤的微血管密度(MVD)及血管内皮生长因子(VEGF)的表达。结果:两种方法成瘤率均为100%,但是裸鼠皮下瘤块生长速度快于Wistar鼠皮下瘤;裸鼠组的MVD与VEGF表达均高于Wistar组,差异有统计学意义(t=8.52、5.13,P<0.05)。结论:用Wistar鼠或裸鼠作为肝癌皮下瘤块模型均可以满足临床试验研究的需要,但由于裸鼠为免疫缺陷动物,瘤块生长速度会明显快于Wistar鼠,且肿瘤血管生成指标更高,故选择肝癌瘤块生长模型时,裸鼠为最佳选择。

Tongxinluo Reverses the Hypoxia-suppressed Claudin-9 in Cardiac Microvascular Endothelial Cells

Background： Claudin-5, claudin-9, and claudin-11 are expressed in endothelial cells to constitute tight junctions, and their deficiency may lead to hyperpermeability, which is the initiating process and pathological basis of cardiovascular disease.Although tongxinluo （TXL） has satisfactory antianginal effects, whether and how it modulates claudin-5, claudin-9, and claudin-1 1 in hypoxia-stimulated human cardiac microvascular endothelial cells （HCMECs） have not been reported.Methods： In this study, HCMECs were stimulated with CoCl2 to mimic hypoxia and treated with TXL.First, the messenger RNA （mRNA） expression of claudin-5, claudin-9, and claudin-l 1 was confirmed.Then, the protein content and distribution of claudin-9, as well as cell morphological changes were evaluated after TXL treatment.Furthermore, the distribution and content histone H3K9 acetylation （H3K9ac） in the claudin-9 gene promoter, which guarantees transcriptional activation, were examined to explore the underlying mechanism, by which TXL up-regulates claudin-9 in hypoxia-stimulated HCMECs.Results： We found that hypoxia-suppressed claudin-9 gene expression in HCMECs （F=7.244;P =0.011） and the hypoxia-suppressed claudin-9 could be reversed by TXL （F=61.911;P =0.000）, which was verified by its protein content changes （F=29.142;P =0.000）.Moreover, high-dose TXL promoted the cytomembrane localization of claudin-9 in hypoxia-stimulated HCMECs, with attenuation of cell injury.Furthermore, high-dose TXL elevated the hypoxia-inhibited H3K9ac in the claudin-9 gene promoter （F=37.766;P =0.000）, activating claudin-9 transcription.Conclusions： The results manifested that TXL reversed the hypoxia-suppressed claudin-9 by elevating H3K9ac in its gene promoter, playing protective roles in HCMECs.

Protective Effect of Naoxintong Capsule(脑心通胶嚢)Combined with Guhong Injection(谷红注射液)on Rat Brain Microvascular Endothelial Cells during Cerebral Ischemia-Reperfusion Injury

Objective:To investigate the synergistic effect of Naoxintong Capsule(NXTC,脑心通胶囊)and Guhong Injection(GHI,谷红注射液)on cerebral ischemia-reperfusion(丨/R)injury.Methods:Forty-eight Sprague-Dawley rats were divided into 6 groups:control group,oxygen and glucose deprivation(OGD)group,nimodipine group(9.375 mg/kg),NXTC group(0.5 g/kg),GHI group(5 mL/kg)and NXTC+GHI group(0.5 g/kg NXTC+5 mL/kg GHI),after the onset of reperfusion and once per day for the following 7 days.Blood was collected 1 h after final administration,and the sera were collected.Cultured primary rat brain microvascular endothelial cells(rBMECs)were subjected to OGD to establish a cell injury model.Untreated rBMECs were used as blank control.The cell counting kit-8 assay was used to assess cell viability using the sera.Malondialdehyde(MDA)and superoxide dismutase(SOD)levels were assessed using an enzyme-linked immunosorbent assay.Apoptosis was evaluated after Hoechst33342 staining using fluorescence microscopy and flow cytometry.JC-1 staining was performed to assess changes in mitochondrial membrane potential.Results:Statistical analysis indicated that more than 95%of the cells were rBMECs.Compared with the OGD group,the cellular morphology of the all drug delivery groups improved.In particular,the combined drug group had the most significant effect.Compared with the OGD group,all drug intervention groups induced a decrease in the apoptotic rate of rBMECs,increased the SOD levels,and decreased the MDA levels(all P<0.01).Compared with the mono-therapy groups,the NXTC+GHI group exhibited a significant improvement in the number of apoptotic rBMECs(P<0.01).All drug intervention groups showed different degrees of increase in membrane potential,and the NXTC+GHI group was higher than the NXTC or GHI group(P<0.01).Conclusion:The combinationa application of NXTC and GHI on cerebral l/R injury clearly resulted in protective benefits.

富马酸二甲酯对过氧化氢诱导心脏微血管内皮细胞铁死亡的影响

目的探讨富马酸二甲酯(DMF)对过氧化氢(H_(2)O_(2))诱导人心脏微血管内皮细胞(HCMEC)铁死亡的影响及其机制。方法体外培养血管内皮细胞,使用H_(2)O_(2)处理内皮细胞,并用不同浓度DMF干预内皮细胞,采用CCK⁃8法测细胞增殖;ELISA法检测细胞炎症水平;Western blot检测铁死亡蛋白GPX4和ACSL4,以及Nrf2/HO⁃1和JAK2/STAT1通路蛋白的改变。结果CCK8实验结果表明,与对照组相比,H_(2)O_(2)可诱导HCMEC增殖能力下降,而DMF成浓度依赖性促进HCMEC增殖(P<0.05)。H_(2)O_(2)诱导的HCMEC细胞炎症因子TNF⁃α、IL⁃1β和IL⁃18水平增加,DMF处理能抑制上述炎症因子的水平(P<0.05)。Western blot结果显示,H_(2)O_(2)处理引起细胞内GPX4蛋白下降,而ACSL4蛋白升高;DMF能抑制H_(2)O_(2)诱导的HCMEC细胞铁死亡(P<0.05)。H_(2)O_(2)可诱导HCMEC中Nrf2和HO⁃1蛋白表达下降,而JAK2和STAT1的磷酸化水平的增加(P<0.05);同H_(2)O_(2)组比,DMF可增加Nrf2和HO⁃1蛋白,并下调JAK2和STAT1的磷酸化水平(P<0.05)。使用Nrf2抑制剂ML385干预细胞,发现其可明显减弱DMF对细胞铁死亡的抑制和HCMEC损伤的保护作用。结论DMF能抑制H_(2)O_(2)诱导的HCMEC炎症和铁死亡。Nrf2/HO⁃1和JAK2/STAT1通路可能在DMF介导的HCMEC保护作用中起到关键作用。

松弛素抑制氧化应激反应保护小鼠心肌微血管内皮细胞的缺氧/复氧损伤

背景:松弛素是人松弛素2的重组形式,作为机体内源性抗纤维化活性物质,松弛素治疗可能会缓解急性心力衰竭患者的症状并改善其预后,但尚未有研究松弛素在氧化应激方面对缺氧/复氧损伤小鼠心肌微血管内皮细胞(H5V)的作用。目的:探讨松弛素在小鼠H5V细胞缺氧/复氧损伤模型中的作用。方法:建立小鼠H5V细胞缺氧/复氧损伤模型,分别为缺氧3,6,12 h,复氧3 h,通过检测细胞活力和乳酸脱氢酶活性确定细胞缺氧/复氧的最佳时间。选用不同质量浓度的松弛素(0,60,100,140,180 ng/mL)作用于H5V细胞缺氧/复氧损伤模型,通过检测细胞活力和乳酸脱氢酶活性确定松弛素干预的最佳质量浓度。在此基础上,将H5V细胞分为3组:对照组、缺氧/复氧模型组、缺氧/复氧+180 ng/mL松弛素组,检测丙二醛、超氧化物歧化酶和活性氧水平。结果与结论:(1)与对照组比较,缺氧6 h/复氧3 h、缺氧12 h/复氧3 h的细胞活力均显著降低(P<0.05),细胞上清中乳酸脱氢酶活性均显著增加(P<0.05),选取缺氧6 h/复氧3 h进行后续实验;(2)与缺氧/复氧模型组比较,缺氧/复氧+松弛素180 ng/mL组细胞活力显著增加(P<0.05),细胞上清中乳酸脱氢酶活性显著降低(P<0.05),选取松弛素180 ng/mL进行后续干预实验;(3)与缺氧/复氧模型组比较,缺氧/复氧+180 ng/mL松弛素组活性氧、丙二醛水平显著降低(P<0.05),超氧化物歧化酶水平显著增加(P<0.05);(4)结果表明,H5V细胞经缺氧6 h/复氧3 h可建立H5V细胞损伤模型,经180 ng/mL松弛素干预后提高了细胞活性和细胞抗氧化应激能力。

黑斑侧褶蛙脑微血管内皮细胞的原代培养及鉴定

为了建立蛙脑微血管内皮细胞原代培养方法,实验以黑斑侧褶蛙脑组织为实验材料,在无菌条件下分离出大脑灰质,利用0.1%Ⅱ型胶原酶和胶原酶-分散酶进行消化,经过Percoll密度梯度离心后,将获取的脑微血管段接种于鼠尾胶包被的培养瓶中,于28℃、5%CO_(2)条件下原代培养蛙脑微血管内皮细胞,并通过细胞形态学观察和Ⅷ因子相关抗原免疫荧光对细胞进行鉴定,最后用四唑蓝比色法(MTT)测定细胞的生长状态。结果显示,微血管段在体外培养1 d后开始贴壁生长,并逐渐扩大成团簇状,培养至7 d时,细胞呈“铺石路样”镶嵌式排列,表现为区域性单层生长;Ⅷ因子免疫荧光检测发现胞质呈红色,表达为阳性,阳性细胞率达97%以上;MTT实验显示,细胞在第3~5天时生长速率最快。本研究首次建立了蛙脑微血管内皮细胞的原代培养与鉴定方法,为体外研究蛙类神经性疾病的发病机理奠定基础,也为相关药物的研发和筛选提供了细胞模型。

差异过筛法体外分离培养原代大鼠脑微血管内皮细胞及其鉴定

目的:采用差异过筛法培养纯度高、活性好的原代大鼠脑微血管内皮细胞(BMECs)。方法:取4周龄SD大鼠脑皮质,经剪碎、细胞筛网过滤、收集网下滤过物、Ⅱ型胶原酶消化后,置于CO_(2)培养箱中进行原代培养。通过细胞形态学观察、血管性血友病因子(vWF)免疫细胞化学染色鉴定所培养的目的细胞。结果:培养24 h后血管段周围爬出短梭形的细胞;48 h后岛屿状的细胞集落形成;72 h后细胞铺满瓶底,呈典型的单层、铺路石样、镶嵌式贴壁生长;免疫细胞化学染色显示,所培养细胞的细胞质呈现棕红色,vWF表达为阳性。结论:差异过筛法能够成功分离培养出原代大鼠BMECs。