Small extracellular vesicles derived from cerebral endothelial cells with elevated microRNA 27a promote ischemic stroke recovery

Axonal remodeling is a critical aspect of ischemic brain repair processes and contributes to spontaneous functional recovery.Our previous in vitro study demonstrated that exosomes/small extracellular vesicles(sEVs)isolated from cerebral endothelial cells(CEC-sEVs)of ischemic brain promote axonal growth of embryonic cortical neurons and that microRNA 27a(miR-27a)is an elevated miRNA in ischemic CEC-sEVs.In the present study,we investigated whether normal CEC-sEVs engineered to enrich their levels of miR-27a(27a-sEVs)further enhance axonal growth and improve neurological outcomes after ischemic stroke when compared with treatment with non-engineered CEC-sEVs.27a-sEVs were isolated from the conditioned medium of healthy mouse CECs transfected with a lentiviral miR-27a expression vector.Small EVs isolated from CECs transfected with a scramble vector(Scra-sEVs)were used as a control.Adult male mice were subjected to permanent middle cerebral artery occlusion and then were randomly treated with 27a-sEVs or Scra-sEVs.An array of behavior assays was used to measure neurological function.Compared with treatment of ischemic stroke with Scra-sEVs,treatment with 27a-sEVs significantly augmented axons and spines in the peri-infarct zone and in the corticospinal tract of the spinal grey matter of the denervated side,and significantly improved neurological outcomes.In vitro studies demonstrated that CEC-sEVs carrying reduced miR-27a abolished 27a-sEV-augmented axonal growth.Ultrastructural analysis revealed that 27a-sEVs systemically administered preferentially localized to the pre-synaptic active zone,while quantitative reverse transcription-polymerase chain reaction and Western Blot analysis showed elevated miR-27a,and reduced axonal inhibitory proteins Semaphorin 6A and Ras Homolog Family Member A in the peri-infarct zone.Blockage of the Clathrin-dependent endocytosis pathway substantially reduced neuronal internalization of 27a-sEVs.Our data provide evidence that 27a-sEVs have a therapeutic effect on stroke recovery by promoting axonal remodeling and improving neurological outcomes.Our findings also suggest that suppression of axonal inhibitory proteins such as Semaphorin 6A may contribute to the beneficial effect of 27a-sEVs on axonal remodeling.

Gamma-glutamyl transferase 5 overexpression in cerebrovascular endothelial cells improves brain pathology,cognition,and behavior in APP/PS1 mice

In patients with Alzheimer’s disease,gamma-glutamyl transferase 5(GGT5)expression has been observed to be downregulated in cerebrovascular endothelial cells.However,the functional role of GGT5 in the development of Alzheimer’s disease remains unclear.This study aimed to explore the effect of GGT5 on cognitive function and brain pathology in an APP/PS1 mouse model of Alzheimer’s disease,as well as the underlying mechanism.We observed a significant reduction in GGT5 expression in two in vitro models of Alzheimer’s disease(Aβ_(1-42)-treated hCMEC/D3 and bEnd.3 cells),as well as in the APP/PS1 mouse model.Additionally,injection of APP/PS1 mice with an adeno-associated virus encoding GGT5 enhanced hippocampal synaptic plasticity and mitigated cognitive deficits.Interestingly,increasing GGT5 expression in cerebrovascular endothelial cells reduced levels of both soluble and insoluble amyloid-βin the brains of APP/PS1 mice.This effect may be attributable to inhibition of the expression ofβ-site APP cleaving enzyme 1,which is mediated by nuclear factor-kappa B.Our findings demonstrate that GGT5 expression in cerebrovascular endothelial cells is inversely associated with Alzheimer’s disease pathogenesis,and that GGT5 upregulation mitigates cognitive deficits in APP/PS1 mice.These findings suggest that GGT5 expression in cerebrovascular endothelial cells is a potential therapeutic target and biomarker for Alzheimer’s disease.

Multifaceted roles of lymphatic and blood endothelial cells in the tumor microenvironment of hepatocellular carcinoma:A comprehensive review

The tumor microenvironment is a complex network of cells,extracellular matrix,and signaling molecules that plays a critical role in tumor progression and metastasis.Lymphatic and blood vessels are major routes for solid tumor metastasis and essential parts of tumor drainage conduits.However,recent studies have shown that lymphatic endothelial cells(LECs)and blood endothelial cells(BECs)also play multifaceted roles in the tumor microenvironment beyond their structural functions,particularly in hepatocellular carcinoma(HCC).This comprehensive review summarizes the diverse roles played by LECs and BECs in HCC,including their involvement in angiogenesis,immune modulation,lymphangiogenesis,and metastasis.By providing a detailed account of the complex interplay between LECs,BECs,and tumor cells,this review aims to shed light on future research directions regarding the immune regulatory function of LECs and potential therapeutic targets for HCC.

Crosstalk among Oxidative Stress,Autophagy,and Apoptosis in the Protective Effects of Ginsenoside Rb1 on Brain Microvascular Endothelial Cells:A Mixed Computational and Experimental Study

Objective Brain microvascular endothelial cells (BMECs) were found to shift from their usually inactive state to an active state in ischemic stroke (IS) and cause neuronal damage. Ginsenoside Rb1 (GRb1),a component derived from medicinal plants,is known for its pharmacological benefits in IS,but its protective effects on BMECs have yet to be explored. This study aimed to investigate the potential protective effects of GRb1 on BMECs. Methods An in vitro oxygen-glucose deprivation/reperfusion (OGD/R) model was established to mimic ischemia-reperfusion (I/R) injury. Bulk RNA-sequencing data were analyzed by using the Human Autophagy Database and various bioinformatic tools,including gene set enrichment analysis (GSEA),Gene Ontology (GO) classification and enrichment analysis,Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis,protein-protein interaction network analysis,and molecular docking. Experimental validation was also performed to ensure the reliability of our findings. Results Rb1 had a protective effect on BMECs subjected to OGD/R injury. Specifically,GRb1 was found to modulate the interplay between oxidative stress,apoptosis,and autophagy in BMECs. Key targets such as sequestosome 1 (SQSTM1/p62),autophagy related 5 (ATG5),and hypoxia-inducible factor 1-alpha (HIF-1α) were identified,highlighting their potential roles in mediating the protective effects of GRb1 against IS-induced damage. Conclusion GRbl protects BMECs against OGD/R injury by influencing oxidative stress,apoptosis,and autophagy. The identification of SQSTM1/p62,ATG5,and HIF-1α as promising targets further supports the potential of GRb1 as a therapeutic agent for IS,providing a foundation for future research into its mechanisms and applications in IS treatment.

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.

Inhibition of viability of human retinal microvascular endothelial cells by vialinin A under high glucose condition

AIM:To investigate the effects of vialinin A on viability of human retinal endothelial cells(HRECs)under high glucose condition and its potential mechanism.METHODS:The HRECs were divided into four groups:normal glucose control group(NG,5 mmol/L D-glucose),high glucose group(HG,30 mmol/L D-glucose),HG+1μmol/L vialinin A group,and HG+5μmol/L vialinin A group.The cell viabilities were measured with cell counting kit-8(CCK-8)assay for proliferation,with scratch assay for migration,and tube formation,for evaluation of the impact of vialinin A on cellular behaviour.Real-time PCR and Western blotting were used to determine the expression level of vascular endothelial growth factor(VEGF).RESULTS:The proliferative capacity and migration of HRECs was reduced by 5μmol/L vialinin A in high glucose environment(both P<0.05).Vialinin A also inhibited highglucose-induced tube formation of HRECs.The expression level of VEGF and PI3K in HRECs was also significantly decreased by vialinin A(P<0.05).CONCLUSION:Vialinin A inhibits the cell viability of HRECs.It may serve as a potential target for anti-angiogenic therapy.

Progress and challenges of cerebrovascular endothelial cells research promoted by single-cell transcriptome sequencing technology

Single-cell transcriptome sequencing has been a rapidly developing and powerful biological tool in recent years,and it plays a vital role in describing tissue development,cell heterogeneity,stress response,etc.Cerebrovascular disease is one of the leading causes affecting human health in the world.Thus,it is important to understand the characteristics of cerebrovascular structure,function,and environmental response.Notably,single-cell transcriptome sequencing provides deeper insights into cerebrovascular research in health and disease states.This article will briefly introduce the basic structure and function of cerebrovascular endothelial cells(ECs),summarize the current research and new findings on cerebrovascular ECs at the single-cell transcriptome level,and discuss the challenges in this field.

Analyzing the pharmacological substances and targets of Xuefu Zhuyu decoction in hypertensive vascular endothelial cells

Background:Xuefu Zhuyu decoction(XFZY)could significantly improve the function of hypertensive vascular endothelial cells,but the targets and mechanism are not clear.This study is to analyze the pharmacological substances and targets of Xuefu Zhuyu decoction in hypertensive vascular endothelial cells.Methods:This study used Xuefu Zhuyu decoction to intervene human umbilical vein endothelial cells incubated by hypertensive patients’serum,then detected the function of vascular endothelial cells.The aqueous extract of XFZY was analyzed and validated by liquid chromatography-mass spectrometry technology;Finally,macromolecular docking technology was used to analyze the potential active substances and targets of XFZY in the prevention and treatment of hypertension.Results:Compared with the model group,the XFZY group showed a significant increase in NO expression(P<0.01)and a significant decrease in ET-1 expression(P<0.001);and the expression of BIP,P-JNK,CHOP,and BAX in XFZY group cells was significantly decreased(P<0.001),while the expression of JNK and BCL2 was significantly increased(P<0.001).19 main compounds were identified in XFZY and there were 3 pairs of molecular complexes with high affinity for markers of the endoplasmic reticulum stress,including BIP-Hesperidin complex,BIP-HSYA complex and JNK-Naringin complex.Conclusion:This study analyzed the potential pharmacodynamic substance and targets of Xuefu Zhuyu decoction in improving the function of hypertensive vascular endothelial cells,which could provide a scientific basis for the future molecular mechanism of XFZY in treating hypertension.

Membrane vesicles derived from Streptococcus suis serotype 2 induce cell pyroptosis in endothelial cells via the NLRP3/Caspase-1/GSDMD pathway

Streptococcus suis serotype 2(S.suis 2)is a zoonotic pathogen that clinically causes severe swine and human infections(such as meningitis,endocarditis,and septicemia).In order to cause widespread diseases in different organs,S.suis 2 must colonize the host,break the blood barrier,and cause exaggerated inflammation.In the last few years,most studies have focused on a single virulence factor and its influences on the host.Membrane vesicles(MVs)can be actively secreted into the extracellular environment contributing to bacteria-host interactions.Gram-negative bacteria-derived outer membrane vesicles(OMVs)were recently shown to activate host Caspase-11-mediated non-canonical inflammasome pathway via deliverance of OMV-bound lipopolysaccharide(LPS),causing host cell pyroptosis.However,little is known about the effect of the MVs from S.suis 2(Gram-positive bacteria without LPS)on cell pyroptosis.Thus,we investigated the molecular mechanism by which S.suis 2 MVs participate in endothelial cell pyroptosis.In this study,we used proteomics,electron scanning microscopy,fluorescence microscope,Western blotting,and bioassays,to investigate the MVs secreted by S.suis 2.First,we demonstrated that S.suis 2 secreted MVs with an average diameter of 72.04 nm,and 200 proteins in MVs were identified.Then,we showed that MVs were transported to cells via mainly dynamin-dependent endocytosis.The S.suis 2 MVs activated NLRP3/Caspase-1/GSDMD canonical inflammasome signaling pathway,resulting in cell pyroptosis,but it did not activate the Caspase-4/-5 pathway.More importantly,endothelial cells produce large amounts of reactive oxygen species(ROS)and lost their mitochondrial membrane potential under induction by S.suis 2 MVs.The results in this study suggest for the first time that MVs from S.suis 2 were internalized by endothelial cells via mainly dynamin-dependent endocytosis and might promote NLRP3/Caspase-1/GSDMD pathway by mitochondrial damage,which produced mtDNA and ROS under induction,leading to the pyroptosis of endothelial cells.

Growth inhibition of hepatocellular carcinoma tumor endothelial cells by miR-204-3p and underlying mechanism

AIM: To investigate the mechanism by which miR-204-3p inhibits the growth of hepatocellular carcinoma (HCC) tumor endothelial cells (TECs).

Cytotoxic effects of betaxolol on healthy corneal endothelial cells both in vitro and in vivo

AIM: To demonstrate the cytotoxic effect of betaxolol and its underlying mechanism on human corneal endothelial cells(HCE cells) in vitro and cat corneal endothelial cells(CCE cells) in vivo,providing experimental basis for safety anti-glaucoma drug usage in clinic of ophthalmology. ·METHODS: In vivo and in vitro experiments were conducted to explore whether and how betaxolol participates in corneal endothelial cell injury. The in vitro morphology,growth status,plasma membrane permeability,DNA fragmentation,and ultrastructure of HCE cells treated with 0.021875-0.28g/L betaxolol were examined by light microscope,3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-di-phenytetrazoliumromide(MTT) assay,acridine orange(AO)/ethidium bromide(EB) double-fluorescent staining,DNA agarose gel electrophoresis,and transmission electron microscope(TEM). The in vivo density,morphology,and ultrastructure of CCE cells,corneal thickness,and eye pressure of cat eyes treated with 0.28g/L betaxolol were investigated by specular microscopy,applanation tonometer,alizarin red staining,scanning electron microscope(SEM),and TEM. · RESULTS: Exposure to betaxolol at doses from 0.0875g/L to 2.8g/L induced morphological and ultrastructural changes of in vitro cultured HCE cells such as cytoplasmic vacuolation,cellular shrinkage,structural disorganization,chromatin condensation,and apoptotic body appearance. Simultaneously,betaxolol elevated plasma membrane permeability and induced DNA fragmentation of these cells in a dose-dependent manner in AO/EB staining. Furthermore,betaxolol at adose of 2.8g/L also induced decrease of density of CCE cells in vivo,and non-hexagonal and shrunk apoptotic cells were also found in betaxolol-treated cat corneal endothelia. ·CONCLUSION: Betaxolol has significant cytotoxicity on HCE cells in vitro by inducing apoptosis of these cells,and induced apoptosis of CCE cells in vivo as well. The findings help provide new insight into the apoptosis-inducing effect of anti-glaucoma drugs in eye clinic.

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.

The relationship between amyloid-beta and brain capillary endothelial cells in Alzheimer's disease

Neurovascular dysfunction,as an integral part of Alzheimer's disease,may have an important influence on the onset and progression of chronic neurodegenerative processes.The bloodbrain barrier(BBB)pathway is one of the main pathways that mediates the clearance of amyloidbeta(Aβ)in the brain parenchyma.A large number of studies have shown that receptors and ATPbinding cassette transporte rs expressed on endothelial cells play an important role in Aβtransport across the BBB,but the specific mechanism is not clear.In this review,we summarize the possible mechanisms of Aβproduction and clearance,and in particular the relationship between Aβand brain capillary endothelial cells.Aβis produced by abnormal cleavage of the amyloid precursor protein via amyloidogenic processing under pathological conditions.Dys regulation of Aβclearance is considered to be the main reason for the massive accumulation of Aβin the brain parenchyma.Several pathways mediating Aβclearance from the brain into the periphery have been identified,including the BBB pathway,the blood-cerebros pinal fluid barrier and arachnoid granule pathway,and the lymphoidrelated pathway.Brain ca pilla ry endothelial cells are the key components of Aβclearance mediated by BBB.Receptors(such as LRP1,RAGE,and FcRn)and ATP-binding cassette transporters(such as P-gp,ABCA1,and ABCC1)expressed on endothelial cells play a critical role in Aβtranscytosis across the BBB.The toxic effects of Aβcan induce dysregulation of receptor and transpo rter expression on endothelial cells.Excessive Aβexerts potent detrimental cerebrovascular effects by promoting oxidative stress,inducing chronic inflammation,and impairing endothelial structure and functions.All of these are main causes for the reduction in Aβclearance across the BBB and the accumulation of Aβin the brain parenchyma.Therefo re,studies on the intera ctions between Aβand brain capillary endothelial cells,including their receptors and transporters,studies on inhibition of the toxic effects of Aβon endothelial cells,and studies on promoting the ability of endothelial cells to mediate Aβclearance may provide new therapeutic strategies for Aβclearance in Alzheimer's disease.

Pathological process of liver sinusoidal endothelial cells in liver diseases

Cirrhosis develops from liver fibrosis and is the severe pathological stage of all chronic liver injury. Cirrhosis caused by hepatitis B virus and hepatitis C virus infection is especially common. Liver fibrosis and cirrhosis involve excess production of extracellular matrix,which is closely related to liver sinusoidal endothelial cells(LSECs). Damaged LSECs can synthesize transforming growth factor-beta and platelet-derived growth factor,which activate hepatic stellate cells and facilitate the synthesis of extracellular matrix. Herein,we highlight the angiogenic cytokines of LSECs related to liver fibrosis and cirrhosis at different stages and focus on the formation and development of liver fibrosis and cirrhosis. Inhibition of LSEC angiogenesis and antiangiogenic therapy are described in detail. Targeting LSECs has high therapeutic potential for liver diseases. Further understanding of the mechanism of action will provide stronger evidence for the development of anti-LSEC drugs and new directions for diagnosis and treatment of liver diseases.

Inhibitive effects of anti-oxidative vitamins on mannitol-induced apoptosis of vascular endothelial cells

Objective: Study blood vessel injury and gene expression indicating vascular endothelial cell apoptosis induced by mannitol with and without administration of anti-oxidative vitamins. Methods: Healthy rabbits were randomly divided into four groups. Mannitol was injected into the vein of the rabbit ear in each animal. Pre-treatment prior to mannitol injection was per- formed with normal saline (group B), vitamin C (group C) and vitamin E (group D). Blood vessel injury was assessed under electron and light microscopy. In a second experiment, cell culture specimen of human umbilical vein endothelial cells were treated with mannitol. Pre-treatment was done with normal saline (sample B), vitamin C (sample C) and vitamin E (sample D). Total RNA was extracted with the original single step procedure, followed by hybridisation and analysis of gene expression. Results: In the animal experiment, serious blood vessel injury was seen in group A and group B. Group D showed light injury only, and normal tissue without pathological changes was seen in group C. Of all 330 apoptosis-related genes analysed in human cell culture specimen, no significant difference was seen after pre-treatment with normal saline, compared with the gene chip without pre-treatment. On the gene chip pre-treated with vitamin C, 45 apoptosis genes were down-regulated and 34 anti-apoptosis genes were up-regulated. Pre-treatment with vitamin E resulted in the down-regulation of 3 apoptosis genes. Conclusion: Vitamin C can protect vascular endothelial cells from mannitol-induced injury.

ROS-related Enzyme Expressions in Endothelial Cells Regulated by Tea Polyphenols

Objective Elevation of reactive oxygen species (ROS), especially the level of superoxide is a key event in many forms of cardiovascular diseases. To study the mechanism of tea polyphenols against cardiovascular diseases, we observed the expressions of ROS-related enzymes in endothelial cells. Methods Tea polyphenols were co-incubated with bovine carotid artery endothelial cells (BCAECs) in vitro and intracellular NADPH oxidase subunits p22phox and p67phox, SOD-1, and catalase protein were detected using Western blot method. Results Tea polyphenols of 0.4 ug/mL and 4.0 ug/mL (from either green tea or black tea) down-regulated NADPH oxidase p22phox and p67phox expressions in a dose-negative manner (P<0.05), and up-regulated the expressions of catalase (P<0.05). Conclusions Tea polyphenols regulate the enzymes involved in ROS production and elimination in endothelial cells, and may be beneficial to the prevention of endothelial cell dysfunction and the development of cardiovascular diseases.

Expression of thymidine kinase mediated by a novel non-viral delivery system under the control of vascular endothelial growth factor receptor 2 promoter selectively kills human umbilical vein endothelial cells

AIM: To investigate the killing efficiency of a recombinant plasmid containing a thymidine kinase (TK) domain insert driven by the vascular endothelial growth factor receptor 2 (VEGFR2) promoter (KDR) on vascular endothelial cells.METHODS: The KDR-TK fragment was extracted from pBluescript Ⅱ KDR-TK plasmid by enzymatic digestion with Xho I and Sal I. The enhanced green fluorescence protein (EGFP) carrier was extracted from pEGFP by the same procedure. The KDR-TK was inserted into the pEGFP carrier to construct pEGFP-KDR-TK. Using ultrasound irradiation and microbubble, pEGFP-KDR-TK was transferred into human umbilical vein endothelial cells (HUVECs). The transient infection rate was estimated by green fluorescent protein (GFP) expression. Transfected HUVECs, non-transfected HUVECs, and HepG2 cells were cultured in the presence of different concentrations of ganciclovir (GCV), and the killing efficacy of HSV-TK/GCV was analyzed by 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazolium bromide (MTT) assay. RESULTS: The recombinant pEGFP-KDR-TK was successfully constructed by inserting the KDR-TK fragment into the pEGFP carrier. Transfected HUVECs showed cytoplasmic green fluorescence, and the transient transfection rate was about 20.3%. Pools of G418-resistant cells exhibited a higher sensitivity to theprodrug/GCV compared to non-transfected HUVECs or non-transfected HepG2 cells, respectively. CONCLUSION: KDR promoter and the suicide gene/prodrug system mediated by diagnostic ultrasound combined with microbubble can significantly kill HUVECs. Such therapy may present a novel and attractive approach to target gene therapy on tumor vessels.

Alphastatin downregulates vascular endothelial cells sphingosine kinase activity and suppresses tumor growth in nude mice bearing human gastric cancer xenografts

AIM： To investigate whether alphastatin could inhibit human gastric cancer growth and furthermore whether sphingosine kinase （SPK） activity is involved in this process. METHODS： Using migration assay, MTT assay and Matrigel assay, the effect of alphastatin on vascular endothelial cells （ECs） was evaluated in vitro. SPK and endothelial differentiation gene （EDG）-1, -3, -5 mRNAs were detected by reverse transcription-polymerase chain reaction （RT-PCR）. SPK activity assay was used to evaluate the effect of alphastatin on ECs. Matrigel plug assay in nude mice was used to investigate the effect of alphastatin on angiogenesis in vivo. Female nude mice were subcutaneously implanted with human gastric cancer cells （BGC823） for the tumor xenografts studies. Micro vessel density was analyzed in Factor Ⅷ-stained tumor sections by the immunohistochemical SP method. RESULTS： In vitro, alphastatin inhibited the migration and tube formation of ECs, but had no effect on proliferation of ECs. RT-PCR analysis demonstrated that ECs expressed SPK and EDG-1, -3, -5 mRNAs. In vivo, alphastatin sufficiently suppressed neovascularization of the tumor in the nude mice. Daily administration of alphastatin produced significant tumor growth suppression. Immunohistochemical studies of tumor tissues revealed decreased micro vessel density in alphastatin-treated animals as compared with controls. CONCLUSION： Downregulating ECs SPK activity may be one of the mechanisms that alphastatin inhibits gastric cancer angiogenesis. Alphastatin might be a useful and relatively nontoxic adjuvant therapy in the treatment of gastric cancer.

A MicroRNA Catalog of Swine Umbilical Vein Endothelial Cells Identified by Deep Sequencing

MicroRNAs （miRNAs） are endogenous -22 nt RNAs that play important regulatory roles in targeting mRNAs for cleavage or translational repression. Despite the discovery of increasing numbers of human and mouse miRNAs, little is known about miRNAs from pig. In this study, we sought to extend the repertoire of porcine small regulatory RNAs using Solexa sequencing. We sequenced a library of small RNAs prepared from immortalized swine umbilical vein endothelial cells （SUVECs）. We produced over 13.6 million short sequence reads, of which 8 547 658 perfectly mapped to the pig genome. A bioinformatics pipeline was used to identify authentic mature miRNA sequences. We identified 154 porcine miRNA genes, among which 146 were conserved across species, and 8 were pig-specific miRNA genes. The 146 miRNA genes encoded 116 conserved mature miRNAs and 66 miRNA^＊. The 8 pig-specific miRNA genes encoded 4 mature miRNAs. Four potential novel miRNAs were identified. The secondary structures of the 154 miRNA genes were predicted; 13 miRNAs have 2 structures, and miR-9 and miR-199 have 4 and 3 structures, respectively. 36 miRNAs were organized into 19 compact clusters, miR-206, miR-21 and miR-378 were the relatively highly expressed miRNAs. In conclusion, Solexa sequencing allowed the successful discovery of known and novel porcine miRNAs with high accuracy and efficiency. Furthermore, our results supply new data to the somewhat insufficient pig miRBase, and are useful for investigating features of the blood-brain barrier, vascular diseases and inflammation.

Hypoxia inducible factor-1α mediates protective effects of ischemic preconditioning on ECV-304 endothelial cells

AIM: To investigate whether hypoxia inducible factor-1α (HIF-1α) is linked to the protective effects of ischemic preconditioning (IP) on sinusoidal endothelial cells against ischemia/reperfusion injury. METHODS: Sinusoidal endothelial cell lines ECV-304 were cultured and divided into four groups: control group, cells were cultured in complete DMEM medium; cold anoxia/warm reoxygenation (A/R) group, cells were preserved in a 4℃ UW solution in a mixture of 95% N2 and 5% CO2 for 24 h; anoxia-preconditioning (APC) group, cells were treated with 4 cycles of short anoxia and reoxygenation before prolonged anoxia- preconditioning treatment; and anoxia-preconditioning and hypoxia inducible factor-1α (HIF-1α) inhibitor (I-HIF-1) group, cells were pretreated with 5 μm of HIF-1α inhibitor NS398 in DMEM medium before subjected to the same treatment as group APC. After the anoxia treatment, each group was reoxygenated in a mixture of 95% air and 5% CO2 incubator for 6 h. Cytoprotections were evaluated by cell viabilities from Trypan blue, lactate dehydrogenase (LDH) release rates, and intracellular cell adhesion molecule-1 (ICAM-1) expressions. Expressions of HIF-1α mRNA and HIF-1α protein from each group were determined by the RT-PCR method and Western blotting, respectively. RESULTS: Ischemia preconditioning increased cell viability, and reduced LDH release and ICAM-1 expressions. Ischemia preconditioning also upregulated the HIF-1α mRNA level and HIF-1α protein expression. However, all of these changes were reversed by HIF-1α inhibitor NS398.CONCLUSION: Ischemia preconditioning effectively inhibited cold hypoxia/warm reoxygenation injury to endothelial cells, and the authors showed for the first time HIF-1α is causally linked to the protective effects of ischemic preconditioning on endothelial cells.