Proteins In Human Umbilical Vein Endothelial Cells Research Articles

Tetrahydroisoquinoline reduces angiogenesis by interacting myeloma cells with HUVECs mediated by extracellular vesicles.

Multiple myeloma (MM) is a neoplastic condition resulting from the uncontrolled expansion of B-cell-derived plasma cells. The importance of angiogenesis in MM development has also been demonstrated. Extracellular vesicles (EVs) have vital functions in interactions between neighboring cells, such as angiogenesis. The objective of this in vitro study was to examine the transfection and angiogenesis effects of MM-EVs on endothelial cells (ECs) upon treatment with Tetrahydroisoquinoline (THIQ) as a bioactive organic compound derivative from isoquinoline. Following treatment of multiple myeloma cells (U266) with THIQ, MM-EVs were harvested and transmigrated to human umbilical vein endothelial cells (HUVEC) in a co-culture model. EVs transmigration was traced by flow cytometry. Correspondingly, the expression of angiogenic genes and/or proteins in U266 cells and HUVECs was measured by RT-PCR and ELISA methods. Likewise, the proliferation and migration of HUVECs treated with THIQ-treated MM-EVs were visualized and estimated by performing both tube formation and scratch wound healing methods. Surprisingly, the anti-angiogenic effect of THIQ-treated MM-EVs was evident by the decreased expression of CD34, VEGFR2, and IL-6 at the mRNA and/or protein levels after internalization of MM-EVs in HUVEC. Finally, tube formation and scratch wound healing experiments showed inhibition of HUVEC cell proliferation and migration by THIQ-treated MM-EVs compared to control MM-EVs. MM-EVs derived from THIQ-treated myeloma cells (U266) inhibited angiogenesis in HUVECs. This phenomenon is coordinated by the internalized THIQ-treated MM-EVs in HUVECs, and ultimately the reduction of angiogenic factors and inhibition of tube formation and scratch wound healing.

Radioprotective effect of polyvinylpyrrolidone modified selenium nanoparticles and its antioxidation mechanism in vitro and in vivo.

Polyvinylpyrrolidone (PVP) is a commonly used biomedical polymer material with good water solubility, biocompatibility, low immunogenicity, and low toxicity. The aim of this study is to investigate the antioxidant mechanism and clinical potential of PVP modified selenium nanoparticles (PVP-Se NPs) as a new radioprotective agent. A laser particle size analyzer and transmission electron microscope were used to characterize PVP-Se nanoparticles prepared by chemical reduction. Human umbilical vein endothelial cells (HUVECs) were used to evaluate the radiation protective effects of PVP-Se NPs. SD rats were employed as an in vivo model to identify the most effective concentration of PVP-Se NPs and assess their potential radioprotective properties. Western blot (WB) was used to detect the expression of nuclear factor kappa-B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling proteins in human umbilical vein endothelial cells (HUVECs) and rat liver and kidney tissues. PVP-Se NPs could reduce the oxidative stress injury and inflammatory response caused by X-ray irradiation in HUVECs and rats, and inhibit cell apoptosis by modulating NF-κB and MAPK signaling pathways. PVP-Se NPs could increase HUVECs viability, reduce apoptosis, inhibit inflammatory factors IL-1β, IL-6 and TNF-α, improve the survival rate of rats, promote antioxidant enzyme activities in cells and rats, reduce malondialdehyde concentration in serum, and reduce the expression of inflammatory factors such as IL-1β, IL-6 and TNF-α in cell supernatant and liver and kidney tissues. PVP-Se NPs could significantly reduce the phosphorylation levels of NF-κB and MAPK pathway-associated proteins in HUVECs and rat liver and kidney tissues (p < 0.05). PVP-Se NPs can protect against radiation-induced oxidative damage by modulating NF-kB and MAPK pathways, providing a theoretical basis and experimental data for their use as an effective radioprotective agent.

Macrophage-derived exosomal miRNA-141 triggers endothelial cell pyroptosis by targeting NLRP3 to accelerate sepsis progression.

Sepsis, critical condition marked by severe organ dysfunction from uncontrolled infection, involves the endothelium significantly. Macrophages, through paracrine actions, play a vital role in sepsis, but their mechanisms in sepsis pathogenesis remain elusive. Objective: We aimed to explore how macrophage-derived exosomes with low miR-141 expression promote pyroptosis in endothelial cells (ECs). Exosomes from THP-1 cell supernatant were isolated and characterized. The effects of miR-141 mimic/inhibitor on apoptosis, proliferation, and invasion of Human Umbilical Vein Endothelial Cells (HUVECs) were assessed using flow cytometry, CCK-8, and transwell assays. Key pyroptosis-related proteins, including caspase-1, IL-18, IL-1β, NLR Family Pyrin Domain Containing 3 (NLRP3), ASC, and cleaved-GSDMD, were analyzed via Western blot. The interaction between miR-141 and NLRP3 was studied using RNAhybrid v2.2 and dual-Luciferase reporter assays. The mRNA and protein level of NLRP3 after exosomal miR-141 inhibitor treatment was detected by qPCR and Western blot, respectively. Exosomes were successfully isolated. miR-141 mimic reduced cell death and pyroptosis-related protein expression in HUVECs, while the inhibitor had opposite effects, increasing cell death, and enhancing pyroptosis protein expression. Additionally, macrophage-derived exosomal miR-141 inhibitor increased cell death and pyroptosis-related proteins in HUVECs. miR-141 inhibits NLRP3 transcription. Macrophages facilitate sepsis progression by secreting miR-141 decreased exosomes to activate NLRP3-mediated pyroptosis in ECs, which could be a potentially valuable target of sepsis therapy.

Feto-placental endothelial dysfunction in Gestational Diabetes Mellitus under dietary or insulin therapy

ObjectiveGestational diabetes mellitus (GDM) is a serious complication in pregnancy. Despite controlling the plasma glucose levels with dietary intervention (GDM-D) or insulin therapy (GDM-I), children born of diabetic mothers suffer more long-term complications from childhood to early adulthood. Placental circulation and nutrient exchange play a vital role in fetal development. Additionally, placental endothelial function is an indicator of vascular health, and plays an important role in maintaining placental circulation for nutrient exchange. This study was conducted to assess changes in fetal endothelial dysfunction in GDM under different interventions during pregnancy.MethodsThe primary human umbilical vein endothelial cells (HUVECs) were obtained from normal pregnant women (n = 11), GDM-D (n = 14), and GDM-I (n = 12) patients. LC-MS/MS was used to identify differentially expressed proteins in primary HUVECs among the three groups, after which Bioinformatics analysis was performed. Glucose uptake, ATP level, apoptosis, and differentially expressed proteins were assessed to investigate changes in energy metabolism.ResultsA total of 8174 quantifiable proteins were detected, and 142 differentially expressed proteins were identified after comparing patients with GDM-D/GDM-I and healthy controls. Of the 142, 64 proteins were upregulated while 77 were downregulated. Bioinformatics analysis revealed that the differentially expressed proteins were involved in multiple biological processes and signaling pathways related to cellular processes, biological regulation, and metabolic processes. According to the results from KEGG analysis, there were changes in the PI3K/AKT signaling pathway after comparing the three groups. In addition, there was a decrease in glucose uptake in the GDM-I (P < 0.01) group. In GDM-I, there was a significant decrease in the levels of glucose transporter 1 (GLUT1) and glucose transporter 3 (GLUT3). Moreover, glucose uptake was significantly decreased in GDM-I, although in GDM-D, there was only a decrease in the levels of GLUT1. ATP levels decreased in GDM-I (P < 0.05) and apoptosis occurred in both the GDM-D and GDM-I groups. Compared to the normal controls, the levels of phosphate AKT and phosphate AMPK over total AKT and AMPK were reduced in the GDM-I group.ConclusionIn summary, endothelial dysfunction occurred in pregnancies with GDM even though the plasma glucose levels were controlled, and this dysfunction might be related to the degree of glucose tolerance. The energy dysfunction might be related to the regulation of the AKT/AMPK/mTOR signaling pathway.

KLF2 alleviates endothelial cell injury and inhibits the formation of THP‑1 macrophage‑derived foam cells by activating Nrf2 and enhancing autophagy.

Atherosclerosis (AS) is an important cause of common vascular diseases. The present study aimed to investigate whether Krüppel like transcription factor 2 (KLF2) could protect against endothelial cell injury and promote cholesterol excretion from foam cells through autophagy. An in vitro AS model was established by the induction of oxidized low-density lipoprotein (ox-LDL) for human umbilical vein endothelial cells (HUVECs). Phorbol-12-myristate-13-acetate (PMA)-induced THP-1 monocytes were differentiated into macrophages which were transformed to foam cells by ox-LDL incubation. The expression of KLF2, adhesion factors, cholesterol efflux regulatory proteins and autophagy-associated proteins in HUVECs or/and THP-1 monocytes was detected by reverse transcription-quantitative PCR and western blot analysis. HUVECs viability, levels of inflammatory factors, formation of foam cells and cholesterol efflux were respectively analyzed by CCK-8 assay, ELISA and Oil Red O staining. KLF2 expression was decreased in ox-LDL-induced HUVECs. KLF2 overexpression attenuated ox-LDL-induced endothelial cell injury, as evidenced by increased cell viability and decreased levels of TNF-α, IL-6, IL-1β, intercellular adhesion molecule 1, vascular cell adhesion molecule-1 and E-selectin. In addition, KLF2 overexpression inhibited the formation of THP-1 macrophage-derived foam cells and promoted lipid efflux. ox-LDL induced decreased KLF2 expression in THP-1 macrophage derived foam cells and KLF2 overexpression activated Nrf2 expression and enhanced autophagy. In conclusion, KLF2 alleviated endothelial cell injury and inhibited the formation of THP-1 macrophage-derived foam cells by activating Nrf2 and enhancing autophagy.

Immunoregulation and clinical significance of neutrophils/NETs-ANGPT2 in tumor microenvironment of gastric cancer.

Although significant progress has been made in the study of gastric cancer (GC), clinicians lack reliable protein markers for accurate diagnosis and tumor stratification. Neutrophil extracellular traps (NETs) are networks of extracellular fibers composed of DNA from neutrophils. We have previously reported that abundant NETs are deposited in GC, damaging human umbilical vein endothelial cells (HUVECs) and triggering the release of tissue factors, leading to a hypercoagulable state in GC. However, the specific effects of NETs on HUVECs are unclear. We aimed to explore the functional changes caused by NETs on HUVECs, providing evidence that NETs may fuel GC progression. Through quantitative proteomics, we identified 6182 differentially expressed proteins in NET-stimulated HUVECs by TMT. The reliability of the TMT technique was confirmed by parallel reaction monitoring (PRM) analysis of 17 differentially expressed proteins. Through bioinformatics analysis, we found that NETs upregulate ANGPT2 in HUVECs. We comprehensively analyzed the prognosis, biological function, immune response, and therapeutic value of ANGPT2 in GC. We found that overexpression of ANGPT2 in GC is associated with poor prognosis and potentially regulates multiple biological functions. At the same time, ANGPT2 also predicted immunotherapeutic and chemotherapeutic responses in GC. In conclusion, NETs promoted ANGPT2 overexpression in the GC microenvironment. In the future, the neutrophil/NETs-ANGPT2 axis may provide a new target for the treatment of GC.

Impact of DICER1 and DROSHA on the Angiogenic Capacity of Human Endothelial Cells.

RNAi-mediated knockdown of DICER1 and DROSHA, enzymes critically involved in miRNA biogenesis, has been postulated to affect the homeostasis and the angiogenic capacity of human endothelial cells. To re-evaluate this issue, we reduced the expression of DICER1 or DROSHA by RNAi-mediated knockdown and subsequently investigated the effect of these interventions on the angiogenic capacity of human umbilical vein endothelial cells (HUVEC) in vitro (proliferation, migration, tube formation, endothelial cell spheroid sprouting) and in a HUVEC xenograft assay in immune incompetent NSGTM mice in vivo. In contrast to previous reports, neither knockdown of DICER1 nor knockdown of DROSHA profoundly affected migration or tube formation of HUVEC or the angiogenic capacity of HUVEC in vivo. Furthermore, knockdown of DICER1 and the combined knockdown of DICER1 and DROSHA tended to increase VEGF-induced BrdU incorporation and induced angiogenic sprouting from HUVEC spheroids. Consistent with these observations, global proteomic analyses showed that knockdown of DICER1 or DROSHA only moderately altered HUVEC protein expression profiles but additively reduced, for example, expression of the angiogenesis inhibitor thrombospondin-1. In conclusion, global reduction of miRNA biogenesis by knockdown of DICER1 or DROSHA does not inhibit the angiogenic capacity of HUVEC. Further studies are therefore needed to elucidate the influence of these enzymes in the context of human endothelial cell-related angiogenesis.

MicroRNA-532-5p-programmed cell death protein 4 (PDCD4) axis regulates angiotensin II-induced human umbilical vein endothelial cell apoptosis and proliferation

BackgroundThis study was carried out to investigate the effect of microRNA miR-532-5p on the proliferation of hypertension endothelial cells. MethodsAngiotensin II (Ang II)-treated human umbilical vein endothelial cells (HUVECs) and primary human aortic endothelial cells (HAECs) were used as cell models to imitate the pathological changes in endothelial cells under hypertensive conditions. The expression levels of miR-532-5p and programmed cell death protein 4 (PDCD4) were detected by Quantitative Real-time PCR (qRT-PCR). The effects of miR-532-5p and PDCD4 on the proliferation of HUVECs and HAECs treated with Ang II were detected by Methyl Thiazolyl Tetrazolium (MTT) assay. The effects of miR-532-5p and PDCD4 on the apoptosis and cell cycle of HUVECs and HAECs treated with Ang II were detected by flow cytometry. Western blot was used to detect the expression levels of PDCD4, apoptosis-related proteins and cycle-related proteins in HUVECs and HAECs treated with Ang II. Bioinformatics analysis and Luciferase gene reporter assay were used to assess the relationship between miR-532-5p and PDCD4. ResultsThe expression levels of miR-532-5p were reduced, while the expression levels of PDCD4 were raised in Ang II-treated HUVECs and HAECs. MiR-532-5p mimic and si-PDCD4 restrained the apoptosis, promoted the proliferation of Ang II-treated HUVECs and HAECs and caused S-phase arrest of cells. PDCD4 was identified as a potential target for miR-532-5p. Knockdown of PDCD4 significantly affected apoptosis and proliferation of Ang II-treated HUVECs. MiR-532-5p regulates apoptosis and proliferation of Ang II-induced HUVECs and HAECs. In addition, overexpression of PDCD4 attenuated the effect of miR-532-5p on the proliferation of Ang II-treated HUVECs and HAECs. ConclusionMiR-532-5p inhibited the expression of PDCD4, thereby inhibiting apoptosis and promoting proliferation of Ang II-treated HUVECs and HAECs.

Panax notoginseng saponins alleviates advanced glycation end product-induced apoptosis by upregulating SIRT1 and antioxidant expression levels in HUVECs.

The present study examined whether Panax notoginseng saponins (PNS) alleviated advanced glycation end product (AGE)-induced apoptosis in human umbilical vein endothelial cells (HUVECs). HUVECs were incubated with 300 µg/ml AGEs alone or AGEs and PNS (0.05, 0.5 or 1 mg/ml) for 48 h. The results of the present study demonstrated that PNS effectively promoted cell viability, inhibited apoptosis and suppressed the activity of caspase-3 in AGE-induced HUVECs. The activities of monocyte chemoattractant protein-1 and malondialdehyde were reduced, and superoxide dismutase activity was increased following treatment with PNS. Furthermore, PNS significantly increased the expression of silent information regulator 1 (SIRT1) and transforming growth factor (TGF)-β1 proteins, and suppressed the expression of inducible nitric oxide synthase and cyclooxyggenase-2 proteins in AGE-induced HUVECs. Therefore, the present study demonstrated that PNS reduced AGE-induced apoptosis by upregulating SIRT1 and antioxidants in HUVECs. The present findings suggest that the PNS may as an important pharmacological agent for AGE-induced cardiovascular injury.

Hypoxia alleviates dexamethasone-induced inhibition of angiogenesis in cocultures of HUVECs and rBMSCs via HIF-1\u03b1

Background and aimInadequate vascularization is a challenge in bone tissue engineering because internal cells are prone to necrosis due to a lack of nutrient supply. Rat bone marrow-derived mesenchymal stem cells (rBMSCs) and human umbilical vein endothelial cells (HUVECs) were cocultured to construct prevascularized bone tissue in osteogenic induction medium (OIM) in vitro. The angiogenic capacity of HUVECs was limited in the coculture system. In this study, the effects of the components in the medium on HUVEC angiogenesis were analyzed.MethodsThe coculture system was established in OIM. Alizarin red staining and alkaline phosphatase staining were used to assess the osteogenic ability of MSCs. A Matrigel tube assay was used to assess the angiogenic ability of HUVECs in vitro. The proliferation of HUVECs was evaluated by cell counting and CCK-8 assays, and migration was evaluated by the streaked plate assay. The expression levels of angiogenesis-associated genes and proteins in HUVECs were measured by qRT-PCR and Western blotting, respectively.ResultsDexamethasone in the OIM suppressed the proliferation and migration of HUVECs, inhibiting the formation of capillary-like structures. Our research showed that dexamethasone stimulated HUVECs to secrete tissue inhibitor of metalloproteinase (TIMP-3), which competed with vascular endothelial growth factor (VEGF-A) to bind to vascular endothelial growth factor receptor 2 (VEGFR2, KDR). This effect was related to inhibiting the phosphorylation of ERK and AKT, which are two downstream targets of KDR. However, under hypoxia, the enhanced expression of hypoxia-inducible factor-1α (HIF-1α) decreased the expression of TIMP-3 and promoted the phosphorylation of KDR, improving HUVEC angiogenesis in the coculture system.ConclusionCoculture of hypoxia-preconditioned HUVECs and MSCs showed robust angiogenesis and osteogenesis in OIM, which has important implications for prevascularization in bone tissue engineering in the future.

Cytoprotective Effects Evaluation of a Novel Danshensu Derivative DEX-018 against Oxidative Stress Injury in HUVECs.

Ischemic heart disease (IHD) is one of the most common cardiovascular diseases with high morbidity and mortality. Danshensu (DSS) is widely used in the treatment of coronary heart disease. In this study, the carboxy group of DSS was esterified with edaravone to synthesize the novel DSS derivative DEX-018 to achieve a synergistic protective effect and overcome the structural deficiency of DSS. The pharmacological effect of DEX-018 against tert-butyl hydrogen peroxide (t-BHP) induced oxidative damage in human umbilical vein endothelial cells (HUVECs) was evaluated. The results demonstrated that pretreatment with DEX-018 significantly increased cell viability and superoxide dismutase (SOD) activity and decreased the lactate dehydrogenase (LDH) leakage rate, malondialdehyde (MDA) level and intracellular reactive oxygen species (ROS) level. In addition, DEX-018 inhibited cell apoptosis and reversed the expression of apoptosis-related proteins (Bcl-2, Bax, and caspase-3) in HUVECs stimulated by t-BHP. Further study on the mechanism of DEX-018 revealed that the expression of p-Akt and p-extracellular signal-regulated kinase 1/2 (ERK1/2) was increased, which suggested that DEX-018 may protect HUVECs against t-BHP induced oxidative injury via the Akt and ERK1/2 signaling pathways. To further validate the correlation, CCK8 was used to detect cell viability after treatment with DEX-018 plus Akt inhibitor (MK2206) and phosphadylinositol 3-kinase (PI3K) inhibitor (LY294002). Compared with DEX-018 alone, MK2206 or LY294002 significantly decreased cell viability of HUVECs, indicating that the protective effect of DEX-018 against t-BHP induced oxidative injury was significantly weakened. It was further verified that the antioxidant and anti-apoptotic effects of DEX-018 were partly related to the PI3K-Akt signaling pathway.

Photobiomodulation alters the viability of HUVECs cells

The aim of the present study was to investigate the influence of low-level red (660nm) and infrared (780nm) laser with four different radiance exposures on human umbilical vein endothelial cells (HUVECs) in vitro. HUVECs (1.5 × 104) were incubated in 96-well culture plates. The cells were maintained in M199 medium supplemented with 20% fetal bovine serum, 1% antibiotic (penicillin), 1% anti-mycotic (Fungizone), and 1% endothelial cell growth supplement. After centrifugation, irradiations (660/780nm, 40mW, 1, 5, 10, and 20J/cm2, 1s, 5s, 10s, and 20s, respectively, total energy 0.4J, 2J, 4J, and 8J, and beam spot size at target 0.04cm2) were performed at the bottom of Falcon tubes such that the laser beam directly reached the cell without passing through the culture medium. The cells were divided into groups based on radiant exposures. Cell viability and protein concentration were verified after 1, 2, 3, 6, 8, and 10days. Red laser increased the cell viability and protein concentration in all groups (three-way ANOVA, p < 0.05) beginning on the second day. The greatest peak compared with the control was found when the radiant exposure was 5J/cm2 and 10J/cm2. Infrared laser inhibited cell viability and modulated the protein concentration in the cells, with the highest peak protein concentration found on the second day in the group with radiant exposure of 1J/cm2 and 10J/cm2 (three-way ANOVA, p < 0.05). Red laser increased the viability and concentration of total proteins in HUVECs, whereas infrared laser had an inhibitory effect on cell viability, while maintaining the total protein concentration similar to that found in the control group.

Effects of Cornu Bubali (CB) on the Adhesion of Leukocyte and Endothelial Cells

Background: The interaction between leukocytes and vascular endothelial cells is ubiquitous in the occurrence and development of many diseases, especially in the body's defense response. The purpose of the present study was to investigate the effect of cornu bubali (CB) on the adhesion of leukocytes to endothelial cells. Materials and methods: Human leukemic cell line (HL-60) and human umbilical vein endothelial cells (HUVECs) were used to simulate the adhesion effect between cells. After HUVECs were treated with TNF- α(15 ng/mL) combined with different dose of CB (15, 30 and 60 μmol/L) and dexamethasone (DEX, 2 μg/ml) for 24 h, HL-60 cells were added into the coculture system for another 1 h. CCK8 assay was performed to investigate cell viability of HUVECs. HL-60 cells adhesion to HUVECs was quantified using Hoechst 33342 staining. Subsequently, the levels of adhesion molecules were detected by the reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis and ELISA, respectively. RT-qPCR and western blot were performed to assess the levels of inflammatory cytokines, chemokines and the expression of Notch signaling pathway. Results: Treatment with CB could reduce the adherence of HL-60 to HUVECs induced by TNF- in a dose-dependent manner. CB inhibited the expression of ICAM-1, VCAM-1, CD44, IL-1β, COX-2 and CCL4 in HUVECs. Western blot and RT-qPCR analysis confirmed that CB prevented TNF-α -induced over-expression of Notch receptors (Notch1 and Notch2), Notch ligands (DLL1 and Jagged1), signaling effectors (Hes1) and adhesion related proteins (NF-κB/p65, p-I B and IκBκ) in HUVECs. Conclusion: CB induces interactions between leukocytes and endothelial cells through the activation of Notch signaling pathway. These data contribute to further explain the protective effect of CB against development of inflammatory process of hemorrhage in acute leukemia.

Development of MicroRNA-146a-Enriched Stem Cell Secretome for Wound-Healing Applications.

Secretome-based therapies have the potential to become the next generation of viable therapeutic wound repair treatments. However, precise strategies aimed to refine and control the secretome composition are necessary to enhance its therapeutic efficacy and facilitate clinical translation. In this study, we aim to accomplish this by transfecting human adipose-derived stem cells (hASCs) with microRNA-146a, which is a potent regulator of angiogenesis and inflammation. The secretome composition obtained from the transfected hASCs (secretome146a) was characterized and compared to nontransfected hASCs secretome to evaluate changes in angiogenic and anti-inflammatory growth factor, cytokine, and miRNA content. In vitro proliferation, migration, and tubular morphogenesis assays using human umbilical vein endothelial cells (HUVECs) were completed to monitor the proangiogenic efficacy of the secretome146a. Finally, the anti-inflammatory efficacy of the secretome146a was assessed using HUVECs that were activated to an inflammatory state by IL-1β. The resulting HUVEC gene expression and protein activity of key inflammatory mediators were evaluated before and after secretome treatment. Overall, the secretome146a contained a greater array and concentration of therapeutic paracrine molecules, which translated into a superior angiogenic and anti-inflammatory efficacy. Therefore, this represents a promising strategy to produce therapeutic secretome for the promotion of wound repair processes.

Liraglutide Increases VEGF Expression via CNPY2-PERK Pathway Induced by Hypoxia/Reoxygenation Injury.

Liraglutide (Lir) is a glucagon-like peptide-1 receptor agonist that lowers blood sugar and reduces myocardial infarct size by improving endothelial cell function. However, its mechanism has not yet been clarified. Unfolded protein response (UPR) plays an important role in the pathogenesis of myocardial ischemia-reperfusion injury. It determines the survival of cells. Endoplasmic reticulum position protein homologue 2 (CNPY2) is a novel initiator of UPR that also participates in angiogenesis. To this extent, the current study further explored whether Lir regulates angiogenesis through CNPY2. In our article, a hypoxia/reoxygenation (H/R) injury model of human umbilical vein endothelial cells (HUVECs) was established and the effect of Lir on HUVECs was first evaluated by the Cell Counting Kit-8. Endothelial tube formation was used to analyze the ability of Lir to induce angiogenesis. Subsequently, the effect of Lir on the concentrations of hypoxia-inducible factor 1α (HIF1α), vascular endothelial growth factor (VEGF), and CNPY2 was detected by enzyme-linked immunosorbent assay. To assess whether Lir regulates angiogenesis through the CNPY2-initiated UPR pathway, the expression of UPR-related pathway proteins (CNPY2, GRP78, PERK, and ATF4) and angiogenic proteins (HIF1α and VEGF) was detected by reverse transcription-polymerase chain reaction and Western blot. The results confirmed that Lir significantly increased the expression of HIF1α and VEGF as well as the expression of CNPY2-PERK pathway proteins in HUVECs after H/R injury. To further validate the experimental results, we introduced the PERK inhibitor GSK2606414. GSK2606414 was able to significantly decrease both the mRNA and protein expression of ATF4, HIF1α, and VEGF in vascular endothelial cells after H/R injury. The effect of Lir was also inhibited using GSK2606414. Therefore, our study suggested that the CNPY2-PERK pathway was involved in the mechanism of VEGF expression after H/R injury in HUVECs. Lir increased the expression of VEGF through the CNPY2-PERK pathway, which may promote endothelial cell angiogenesis and protect HUVEC from H/R damage.

Suppressive effects of collismycin C on polyphosphate-mediated vascular inflammatory responses

Human endothelial cells-derived polyphosphate (PolyP) is one of the pro-inflammatory mediators as suggested by the previous reports. 2,2′-bipyridine containing natural products are generally accepted to have antimicrobial, cytotoxic and anti-inflammatory properties. This study was undertaken to investigate whether a 2,2′-bipyridine containing natural product, collismycins C, can modulate PolyP-mediated inflammatory responses in human umbilical vein endothelial cells (HUVECs) and in mice. After HUVECs or mice were activated with PolyP, cells or mice were post-treated with collismycins C. The anti-inflammatory activities of collismycins C were determined by measuring permeability, leukocytes adhesion and migration, and activation of pro-inflammatory proteins in PolyP-activated HUVECs and mice. In addition, the beneficial effects of collismycins C on survival rate in PolyP-injected mice. Collismycins C inhibits PolyP-mediated barrier disruption, the expressions of cell adhesion molecules, and leukocyte to HUVEC adhesion/migration. Interestingly, PolyP-induced NF-κB activation and the productions of TNF-α and IL-6 were inhibited by collismycins C in HUVECs. These anti-inflammatory functions of collismycins C were confirmed in PolyP injected mice. In conclusion, based on the anti-inflammatory effects of collismycins C in PolyP-mediated septic response, collismycins C have therapeutic potential for various systemic inflammatory diseases.

Effect of microRNA-34a/SIRT1/p53 signal pathway on notoginsenoside R₁ delaying vascular endothelial cell senescence

This study aimed to investigate the effect of notoginsenoside R₁ in delaying H₂O₂-induced vascular endothelial cell senescence through microRNA-34a/SIRT1/p53 signal pathway. In this study， human umbilical vein endothelial cells(HUVECs) were selected as the study object; the aging model induced by hydrogen peroxide(H₂O₂) was established， with resveratrol as the positive drug. HUVECs were randomly divided into four groups， youth group， senescence model group， notoginsenoside R₁ group and resveratrol group. Notoginsenoside R₁ group and resveratrol group were modeled with 100 μmoL·L⁻¹ H₂O₂ for 4 h after 24 h treatment with notoginsenoside R₁(30 μmoL·L⁻¹) and resveratrol(10 μmoL·L⁻¹) respectively. At the end， each group was cultured with complete medium for 24 h. The degree of cellular senescence was detected by senescence-associated β-galactosidase(SA-β-Gal) staining kit， the cell viability was detected by cell counting kit-8， the cell cycle distribution was analyzed by flow cytometry， and the cellular SOD activity was detected by WST-1 method in each group. The expressions of SIRT1， p53， p21 and p16 proteins in HUVECs were detected by Western blot. In addition， the mRNA expressions of miRNA-34a， SIRT1 and p53 in HUVECs were assayed by Real-time PCR. These results indicated that notoginsenoside R₁ significantly reduced the positive staining rate of senescent cells， enhanced the cell proliferation capacity and intracellular SOD activity， decreased the proportion of cells in G₀/G₁ phase， and increased the percentage of cells in S phase simultaneously compared with the senescence model group. Moreover， notoginsenoside R₁ decreased the mRNA expressions of miRNA-34a and p53 and the protein expression of p53， p21 and p16.At the same time， notoginsenoside R₁ increased the protein and mRNA expressions of SIRT1. The differences in these results between the senescence model group and the notoginsenoside R₁ group were statistically significant(P<0.05). However， there was not statistically significant difference in these results between the notoginsenoside R₁ group and the resveratrol group. In conclusion， the senescence of endothelial cells induced by H₂O₂ can be used as a model for studying aging. Notoginsenoside R₁ has an obvious anti-aging effect on vascular endothelial cells in this study. The possible mechanism is that notoginsenoside R₁ can delay the senescence process of vascular endothelial cells induced by H₂O₂ by regulating microRNA-34a/SIRT1/p53 signal pathway.

Effect of overexpression of transcription factor Runx2 and Osterix on osteogenic differentiation of endothelial cells

To explore the effect of overexpression of Runx2 and Osterix (OSX) genes on osteogenic differentiation of human umbilical vein endothelial cells (HUVECs). Overexpressed Runx2 and OSX lentiviral vectors were transfected into HUVECs respectively. The osteogenic potential of transfected cells was identified by alkaline phosphatase (ALP) staining and ALP activity. Furthermore, real time-PCR, Western blot and immunofluorescence staining were performed to detect the expression of osteogenic genes and proteins in HUVECs. GraphPad Prism 6.01 software was used for statistical analysis. Overexpression of Runx2 gene was beneficial for osteogenic differentiation of HUVECs, while overexpression of osterix gene did not show osteogenic differential potential. Moreover, overexpression of Runx2 gene in HUVECs up-regulated the gene expression level of Runx2, OSX, ALP, bone sialoprotein (BSP), osteopontin (OPN), and osteocalcin (OCN), and up-regulated protein level of OPN and OCN. Overexpression of Runx2 could promote osteogenic differentiation of HUVECs.

TRPC1 stimulates calcium‑sensing receptor‑induced store‑operated Ca2+ entry and nitric oxide production in endothelial cells.

Store-operated Ca2+ entry (SOCE) via store-operated Ca2+ channels (SOCC), encoded by transient receptor potential canonical (TRPC) channel proteins, is an important underlying mechanism regulating intracellular Ca2+ concentration ([Ca2+]i) and various intracellular functions in endothelial cells (ECs). TRPC1, the probable candidate for SOCC, is expressed in ECs. Ca2+-sensing receptor (CaSR) is functionally expressed in vascular endothelium and is important in Ca2+ mobilization and cardiovascular functions. To date, there have been no reports demonstrating an association between CaSR and TRPC1 in ECs. The present study investigated the effects of TRPC1 on CaSR-induced Ca2+ influx and nitric oxide (NO) production in human umbilical vein ECs (HUVECs). TRPC1 and CaSR proteins in HUVECs were measured by immunostaining and western blot analysis. [Ca2+]i levels were measured using the Fura-2-acetoxymethyl ester method. The indicator 3-amino, 4-aminomethyl-2, 7-difluorescein diacetate was used to measure NO production in HUVECs. The expression of TRPC1 protein in HUVECs was silenced by transfecting HUVECs with small interfering RNA (siRNA) against TRPC1. Although changes in extracellular Ca2+ failed to alter [Ca2+]i in HUVECs, the CaSR agonist spermine increased [Ca2+]i and NO production in HUVECs. NO production in HUVECs was diminished in Ca2+-free medium or following treatment with a CaSR negative allosteric modulator (Calhex231), SOCC inhibitor (MRS1845) or TRPC inhibitor (SKF96365). The spermine-induced increases in [Ca2+]i and NO production were reduced in HUVECs transfected with TRPC1 siRNA. These results suggested that TRPC1 is a primary candidate in forming SOCC that stimulates CaSR-induced SOCE and NO production in HUVECs and is a potential therapeutic target for vascular diseases.

MiR-551b-5p Contributes to Pathogenesis of Vein Graft Failure via Upregulating Early Growth Response-1 Expression.

Background:Vein graft failure (VGF) is a serious complication of coronary artery bypass graft, although the mechanism remains unclear. The study aimed to investigate the effects of microRNAs (miRNAs) on the endothelial dysfunction involved in VGF.Methods:Human umbilical vein endothelial cells (HUVECs) were subjected to mechanical stretch stimulation to induce endothelial dysfunction. Genome-wide transcriptome profiling was performed using the Human miRNA OneArray® V4 (PhalanxBio Inc., San Diego, USA). The miRNA-messenger RNA (mRNA) network was investigated using gene ontology and Kyoto Encyclopedia of Genes and Genomes. The miR-551b-5p mimic and inhibitor were applied to regulate miR-551b-5p expression in the HUVECs. The 5-ethynyl-2’-deoxyuridine assay, polymerase chain reaction (PCR), and Western blotting (WB) were used to assess HUVECs proliferation, mRNA expression, and protein expression, respectively. The vein graft model was established in early growth response (Egr)-1 knockout (KO) mice and wide-type (WT) C57BL/6J mice for pathological and immunohistochemical analysis. Endothelial cells isolated from the veins of WT and Egr-1 KO mice were subjected to mechanical stretch stimulation; PCR and WB were conducted to confirm the regulatory effect of Egr-1 on Intercellular adhesion molecule (Icam-1). One-way analysis of variance and independent t-test were performed for data analysis.Results:Thirty-eight miRNAs were differentially expressed in HUVECs after mechanical stretch stimulation. The bioinformatics analysis revealed that Egr-1 might be involved in VGF and was a potential target gene of miR-551b-5p. The mechanical stretch stimulation increased miR-551b-5p expression by 2.93 ± 0.08 fold (t = 3.07, P < 0.05), compared with the normal HUVECs. Transfection with the miR-551b-5p mimic or inhibitor increased expression of miR-551b-5p by 793.1 ± 171.6 fold (t = 13.84, P < 0.001) or decreased by 26.3% ± 2.4% (t = 26.39, P < 0.05) in the HUVECs, respectively. HUVECs proliferation and EGR-1 mRNA expression were significantly suppressed by inhibiting miR-551b-5p expression (P < 0.05). The lumens of the vein grafts in the Egr-1 KO mice were wider than that in the WT mice. Icam-1 expression was suppressed significantly in the Egr-1 KO vein grafts (P < 0.05).Conclusions:Increased miR-551b-5p expression leads to endothelial dysfunction by upregulating Egr-1 expression. EGR-1 KO can improve the function of a grafted vein through suppressing Icam-1.