Barrier protective effects of rutin in LPS-induced inflammation in vitro and in vivo

Rutin, an active flavonoid compound, is well known to possess potent antiplatelet, antiviral and antihypertensive properties. In this study, we first investigated the possible barrier protective effects of rutin against pro-inflammatory responses in human umbilical vein endothelial cells (HUVECs) induced by lipopolysaccharide (LPS) and the associated signaling pathways. The barrier protective activities of rutin were determined by measuring permeability, monocytes adhesion and migration, and activation of pro-inflammatory proteins in LPS-activated HUVECs. We found that rutin inhibited LPS-induced barrier disruption, expression of cell adhesion molecules (CAMs) and adhesion/transendothelial migration of monocytes to human endothelial cells. Rutin also suppressed acetic acid induced-hyperpermeability and carboxymethylcellulose-induced leukocytes migration in vivo. Further studies revealed that rutin suppressed the production of tumor necrosis factor-α (TNF-α) and activation of nuclear factor-κB (NF-κB) by LPS. Collectively, these results suggest that rutin protects vascular barrier integrity by inhibiting hyperpermeability, expression of CAMs, adhesion and migration of leukocytes, thereby endorsing its usefulness as a therapy for vascular inflammatory diseases.     

Barrier protective effects of withaferin A in HMGB1-induced inflammatory responses in both cellular and animal models

Withaferin A (WFA), an active compound from Withania somnifera, is widely researched for its anti-inflammatory, cardioactive and central nervous system effects. In this study, we first investigated the possible barrier protective effects of WFA against pro-inflammatory responses in human umbilical vein endothelial cells (HUVECs) and in mice induced by high mobility group box 1 protein (HMGB1) and the associated signaling pathways. The barrier protective activities of WFA were determined by measuring permeability, leukocytes adhesion and migration, and activation of pro-inflammatory proteins in HMGB1-activated HUVECs. We found that WFA inhibited lipopolysaccharide (LPS)-induced HMGB1 release and HMGB1-mediated barrier disruption, expression of cell adhesion molecules (CAMs) and adhesion/transendothelial migration of leukocytes to human endothelial cells. WFA also suppressed acetic acid-induced hyperpermeability and carboxymethylcellulose-induced leukocytes migration in vivo. Further studies revealed that WFA suppressed the production of interleukin 6, tumor necrosis factor-α (TNF-α) and activation of nuclear factor-κB (NF-κB) by HMGB1. Collectively, these results suggest that WFA protects vascular barrier integrity by inhibiting hyperpermeability, expression of CAMs, adhesion and migration of leukocytes, thereby endorsing its usefulness as a therapy for vascular inflammatory diseases.     

Protective effect of diphlorethohydroxycarmalol isolated from Ishige okamurae against high glucose-induced-oxidative stress in human umbilical vein endothelial cells

In the present study, the protective effect of diphlorethohydroxycarmalol (DPHC) isolated from Ishige okamurae, a brown algae, on high glucose-induced-oxidative stress was investigated using human umbilical vein endothelial cells (HUVECs). High concentration of glucose (30 mM) treatment induced cytotoxicity whereas DPHC prevented cells from high glucose-induced damage; restoring cell viability was significantly increased. In addition, the lipid peroxidation, intracellular reactive oxygen species (ROS), and nitric oxide (NO) levels induced by high glucose treatment were effectively inhibited by addition of DPHC in a dose-dependent manner. DPHC also suppressed the over-expressions of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) proteins as well as nuclear factor-kappa B (NF-κB) activation induced by high glucose in HUVECs. These finding indicate that DPHC might be used as potential pharmaceutical agent which will reduce the damage caused by high glucose-induced-oxidative stress associated with diabetes.     

Sargachromenol protects against vascular inflammation by preventing TNF-α-induced monocyte adhesion to primary endothelial cells via inhibition of NF-κB activation

Vascular inflammation is a key factor in the pathogenesis of atherosclerosis. The purpose of this study was to investigate the protective effects of sargachromenol (SCM) against tumor necrosis factor (TNF)-α-induced vascular inflammation. SCM decreased the expression of cell adhesion molecules, including intracellular adhesion molecule-1 and vascular cell adhesion molecule-1, in TNF-α-stimulated human umbilical vein endothelial cells (HUVECs), resulted in reduced adhesion of monocytes to HUVECs. SCM also decreased the production of monocyte chemoattractant protein-1 and matrix metalloproteinase-9 in TNF-α-induced HUVECs. Additionally, SCM inhibited activation of nuclear factor kappa B (NF-κB) induced by TNF-α through preventing the degradation of inhibitor kappa B. Moreover, SCM reduced the production of reactive oxygen species in TNF-α-treated HUVECs. Overall, SCM alleviated vascular inflammation through the regulation of NF-κB activation and through its intrinsic antioxidant activity in TNF-α-induced HUVECs. These results indicate that SCM may have potential application as a therapeutic agent against vascular inflammation.     

Vaspin prevents TNF-α-induced intracellular adhesion molecule-1 via inhibiting reactive oxygen species-dependent NF-κB and PKCθ activation in cultured rat vascular smooth muscle cells

Vaspin (visceral adipose tissue-derived serine protease inhibitor) was recently identified as a novel adipocytokine with insulin-sensitizing effects. We hypothesized that vaspin could play a role in vascular inflammation. To test the hypothesis, we investigated the effects of vaspin on TNF-α-stimulated vascular smooth muscle cells (SMCs) focusing on inflammatory signal transduction. Vascular SMCs from mesenteric artery of male Wistar rats were treated with TNF-α (5–10 ng/ml, 20 min–6 h) in the absence or presence of vaspin (1–300 ng/ml, pretreatment for 24 h). Western blotting was performed to analyze the cellular signal. Reactive oxygen species (ROS) generation was fluorometrically measured using 2′,7′-diclorofluorescein diacetate. Vaspin alone treatment had no effect on vascular SMCs morphology and cellular signal. Vaspin significantly decreased the TNF-α-induced monocyte adhesion to SMCs. Vaspin significantly inhibited the protein expression of intracellular adhesion molecule (ICAM)-1 and the phosphorylation of NF-κB and protein kinase C (PKC)θ induced by TNF-α. Both of NF-κB and novel PKC inhibitors significantly attenuated the TNF-α-induced ICAM-1 expression. Moreover, vaspin inhibited TNF-α-induced ROS generation. An anti-oxidant, N-acetyl-l-cysteine blocked the TNF-α-induced activation of NF-κB, PKCθ and expression of ICAM-1. The present results demonstrated for the first time that vaspin inhibits TNF-α-induced expression of ICAM-1 via preventing the ROS generation and subsequent activation of NF-κB and PKCθ. Consequently, vaspin could play inhibitory roles on inflammatory states of vascular SMCs.     

Suppression of adhesion molecule expression by phenanthrene-containing extract of bulbils of Chinese Yam in vascular smooth muscle cells through inhibition of MAPK,Akt and NF-κB

Atherosclerosis is a chronic inflammatory disease associated with increased expression of adhesion molecules in vascular smooth muscle cells (VSMCs). The objective of this study was to examine the in vitro effects of extract from aerial Bulbil of Dioscorea batatas Decne (Db-Ex) on the ability to suppress the expression of adhesion molecules induced by TNF-α. We also identified bioactive components from a methanol extract. VSMCs pre-exposed to Db-Ex (10–100 μg/ml) were stimulated with TNF-α (10 ng/ml). Preincubation of VSMCs for 2 h with Db-Ex dose-dependently inhibited TNF-α-induced adhesion of THP-1 monocytic cells and mRNA and protein expression of vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1). Db-Ex treatment decreased ROS production and the amount of phosphorylated form of p38, ERK, JNK and Akt in TNF-α-stimulated cells, suggesting that Db-Ex inhibits adhesion molecule expression possibly through MAPK and Akt regulation. Db-Ex also suppressed TNF-α-activation NK-κB. This effect was mediated through degradation of IκBα and nuclear translocation of the p65 subunit of NF-κB. These results suggest that Db-Ex inhibits monocyte adhesion and the TNF-α-mediated induction of adhesion molecules in VSMC by downregulating the MAPK/Akt/NF-κB signaling pathway, which may explain the ability of Db-Ex to suppress inflammation within the atherosclerotic lesion.     

Geniposide inhibits high glucose-induced cell adhesion through the NF-KB signaling pathway in human umbilical vein endothelial cells

Aim:

To investigate whether geniposide, an iridoid glucoside extracted from gardenia jasminoides ellis fruits, inhibits cell adhesion to human umbilical vein endothelial cells (HUVECs) induced by high glucose and its underlying mechanisms.

Methods:

HUVECs were isolated from human umbilical cords and cultured. The adhesion of monocytes to HUVECs was determined using fluorescence-labeled monocytes. The mRNA and protein levels of vascular cell adhesion molecule-1 (VCAM-1) and endothelial selectin (E-selectin) were measured using real-time RT-PCR and ELISA. Reactive oxygen species (ROS) production was measured using a fluorescent probe. The amounts of nuclear factor-kappa B (NF-κB) and inhibitory factor of NF-κB (IκB) were determined using Western blot analysis. The translocation of NF-κB from the cytoplasm to the nucleus was determined using immunofluorescence.

Results:

Geniposide (10–20 μmol/L) inhibited high glucose (33 mmol/L)-induced adhesion of monocytes to HUVECs in a dose-dependent manner. This compound (5–40 μmol/L) also inhibited high glucose-induced expression of VCAM-1 and E-selectin at the gene and protein levels. Furthermore, geniposide (5–20 μmol/L) decreased ROS production and prevented IκB degradation in the cytoplasm and NF-κB translocation from the cytoplasm to the nucleus in HUVECs.

Conclusion:

Geniposide inhibits the adhesion of monocytes to HUVECs and the expression of CAMs induced by high glucose, suggesting that the compound may represent a new treatment for diabetic vascular injury. The mechanism underlying this inhibitory effect may be related to the inhibition of ROS overproduction and NF-κB signaling pathway activation by geniposide.     

Inhibition of TNF-α-induced adhesion molecule expression by diosgenin in mouse vascular smooth muscle cells via downregulation of the MAPK,Akt and NF-κB signaling pathways

Atherosclerosis is a chronic inflammatory disease and the expression of adhesion molecules on vascular smooth muscle cells (VSMCs) contributes to the progress of the disease. Diosgenin, a precursor of steroid hormones, has been shown to have a variety of biological activities including anti-inflammatory activity; however, its molecular mechanisms are poorly understood. This study examined the effect of diosgenin on the expression of adhesion molecules induced by TNF-α in cultured mouse VSMC cell line, MOVAS-1. Preincubation of VSMCs for 2 h with diosgenin (0.1–10 μM) dose-dependently inhibited TNF-α-induced adhesion of THP-1 monocytic cells and mRNA and protein expression of vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1). Diosgenin abrogated TNF-α induced production of intracellular reactive oxygen species (ROS) and phosphorylation of p38, ERK, JNK and Akt. Diosgenin was also shown to inhibit NK-κB activation induced by TNF-α. Furthermore, diosgenin inhibited TNF-α-induced IκB kinase activation, subsequent degradation of IκBα, and nuclear translocation of NF-κB. Our results indicate that diosgenin inhibits the adhesive capacity of VSMC and the TNF-α-mediated induction of ICAM-1 and VCAM-1 in VSMC by inhibiting the MAPK/Akt/NF-κB signaling pathway and ROS production, which may explain the ability of diosgenin to suppress inflammation within the atherosclerotic lesion and modulate immune response.     

Statins protect human endothelial cells from TNF-induced inflammation via ERK5 activation

3-Hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) exert pleiotropic effects on the cardiovascular system, in part through a decrease in reactive oxygen species (ROS) formation and reduction of vascular inflammation. To elucidate the molecular mechanisms involved in these effects, we investigated the effect of statins on TNF-α-induced ROS production, vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) expression in human aortic endothelial cells (HAECs). Exposure of HAECs to TNF-α caused production of ROS via Rac-1 membrane translocation and activation. The Rac-1 activation and ROS liberation mediated TNF-stimulated NF-κB activation and the subsequent VCAM-1 and ICAM-1 expression. Extracellular-signal-regulated kinase 5 (ERK5) plays a central role in inhibiting endothelial inflammation. Immune complex kinase assay of protein extracts from HAECs treated with atorvastatin revealed increased ERK5 activity in a time- and dose-dependent manner. In addition, pretreatment with atorvastatin inhibited TNF-α-induced ROS production and VCAM-1 and ICAM-1 expression. Chemical or genetic inhibition of ERK5 ablated the statins inhibition of Rac-1 activation, ROS formation, NF-κB, VCAM-1 and ICAM-1 expression induced by TNF-α. Taken together, statins, via ERK5 activation, suppress TNF-stimulated Rac-1 activation, ROS generation, NF-κB activation and VCAM-1 and ICAM-1 expression in human ECs, which provides a novel explanation for the pleiotropic effects of statins that benefit the cardiovascular system.     

Motorcycle exhaust particles up-regulate expression of vascular adhesion molecule-1 and intercellular adhesion molecule-1 in human umbilical vein endothelial cells

Epidemiological studies have shown that there is a strong correlation between atherosclerosis and ambient air pollution. In this study, we found that motorcycle exhaust particles (MEP) induced adhesion between cells of the human monocytic leukemia cell line (THP-1) and human umbilical vein endothelial cells (HUVECs) in a time-and dose-dependent manner. In addition, MEP treatment induced both mRNA and protein expression of vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) in HUVECs. The IκB degradation and p65 nuclear translocation was found in MEP-treated HUVECs, suggested the involvement of nuclear factor-κB (NF-κB). MEP-induced VCAM-1 and ICAM-1 protein expression was inhibited by NF-κB inhibitor BAY 11-7085. Oxidative stress was also involved in the signaling of VCAM-1 and ICAM-1 expression. MEP treatment caused hydrogen peroxide and superoxide formation. Pretreatment with α-tocopherol could inhibit MEP-induced reactive oxygen intermediates generation and suppressed MEP-induced IκB degradation and adhesion molecules expression. Furthermore, the carbon black (CB) nanoparticles with different diameters could induce VCAM-1 and ICAM-1 protein expression; however, polycyclic aromatic hydrocarbons (PAHs) only increased the expression of ICAM-1 but not that of VCAM-1 in HUVECs. In this study, we found that MEPs could induce ICAM-1 and VCAM-1 expression through oxidative stress and NF-κB activation in HUVECs.     

Inhibitory effect of reinioside C on monocyte–endothelial cell adhesion induced by oxidized low-density lipoprotein via inhibiting NADPH oxidase/ROS/NF-κB pathway

Monocyte adhesion to activated vascular endothelial cells is the critical event in the initiation of atherosclerosis. Adhesion molecules are inflammatory markers, which are upregulated by oxidized low-density lipoprotein (ox-LDL) and play a pivotal role in atherogenesis. In present study, the effect of reinioside C, a major compound of Polygala fallax Hemsl., on adhesion of monocytes to endothelial cells induced by ox-LDL was investigated. The results showed that incubation of endothelial cells with ox-LDL (100?µg/mL) for 24 h markedly increased the expression of ICAM-1 and P-selectin and enhanced the adhesion of monocytes to endothelial cells. Pretreatment with reinioside C (1, 3, or 10?µM) dose-dependently decreased ox-LDL-induced upregulation of expression of ICAM-1 and P-selectin and the enhanced adhesion of monocytes to endothelial cells. To determine the role of NADPH oxidase/reactive oxygen species (ROS)/nuclear factor-κB (NF-κB) pathway, endothelial cells were treated with ox-LDL (100?µg/mL) for 2 h, and NADPH oxidase subunit (Nox 2 and p22^phox) mRNA expression, intracellular ROS level, and NF-κB activity were measured. The results showed that reinioside C attenuated ox-LDL-induced NADPH oxidase subunit (Nox 2 and p22^phox) mRNA expression, generation of ROS, and activation of NF-κB in endothelial cells in a dose-dependent manner; the two latter effects were inhibited by pyrollidine dithiocarbamate, the inhibitor of NF-κB. These findings suggest that reinioside C attenuates ox-LDL-induced expression of adhesion molecules (P-selectin and ICAM-1) and the adhesion of monocytes to endothelial cells by inhibiting NADPH oxidase/ROS/NF-κB pathway.     

Protective effects of dieckol isolated from Ecklonia cava against high glucose-induced oxidative stress in human umbilical vein endothelial cells

The effect of dieckol, one of phlorotannin polyphenol compound purified from Ecklonia cava (E. cava) against high glucose-induced oxidative stress was investigated using human umbilical vein endothelial cells (HUVECs), which is susceptible to oxidative stress. High glucose (30 mM) treatment induced HUVECs cell death, but dieckol, at concentration 10 or 50 μg/ml, significantly inhibited the high glucose-induced cytotoxicity. Furthermore, treatment with dieckol dose-dependently decreased thiobarbituric acid reactive substances (TBARS), intracellular reactive oxygen species (ROS) generation and nitric oxide level increased by high glucose. In addition, high glucose levels induced the overexpressions of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and nuclear factor-kappa B (NF-kB) proteins in HUVECs, but dieckol treatment reduced the overexpressions of these proteins. These findings indicate that dieckol is a potential therapeutic agent that will reduce the damage caused by hyperglycemia-induced oxidative stress associated with diabetes.     

Amelioration of uremic toxin indoxyl sulfate-induced endothelial cell dysfunction by Klotho protein

Indoxyl sulfate (IS), a common kind of uremic toxin, is considered as a risk factor for aggravating endothelial function in CKD patients due to its oxidative activity. The anti-aging protein Klotho, which is produced by the kidneys and down-regulated in uremic conditions, has the ability to resist oxidative stress. Here, we carried out an in vitro study to investigate the deleterious effects of IS on endothelial cells and the protective role of Klotho protein. The cultured human umbilical vein endothelial cells (HUVECs) were incubated with IS in the presence or absence of Klotho protein. The release of reactive oxygen species (ROS) and the expression of monocyte chemoattractant protein-1 (MCP-1) were enhanced while the cell viability and production of nitric oxide (NO) were inhibited by IS in a concentration-dependent manner. Meanwhile, the phosphorylation of p38MAPK and the nuclear translocation of NF-κB were increased in HUVECs treated with IS. Pretreatment with Klotho protein resulted in remarkable increase of cell viability and decrease of ROS production in IS-treated HUVECs. Like ROS scavenger, N-acetyl-l-cysteine (NAC), Klotho protein could inhibit the IS-induced activations of p38MAPK and NF-κB. Moreover, Klotho protein could also attenuate IS-induced reduction of NO production and up-regulation of MCP-1 expression. These results suggest that IS can damage the functions of endothelial cells. Klotho protein has the ability to ameliorate the IS-induced endothelial dysfunction, which may be partly through inhibiting the ROS/p38MAPK and downstream NF-κB signaling pathways.     

参附对脐静脉内皮细胞Toll样受体4/NF-κB途径的影响

目的观察参附注射液对内毒素介导的人脐静脉细胞Toll样受体4/NF-κB途径及细胞间黏附分子、E-选择素表达的影响。方法健康产妇分娩后的新鲜婴儿脐带,应用胶原酶消化,收集内皮细胞进行培养。实验分为对照组、内毒素组、内毒素+参附组。对照组:M199培养基中不加任何物质。内毒素组:M199培养基中加入脂多糖1 mg/L。内毒素+参附组:预先加入参附注射液10 mL/L,30 min后加入脂多糖1 mg/L。干预1h收集细胞,提取核蛋白测定NF-κB活性,干预12 h后收集细胞检测Toll样受体4、细胞间黏附分子1、E-选择素表达水平。结果内毒素组的Toll样受体4、细胞间黏附分子1、E-选择素表达水平、NF-κB活性均显著高于对照组,内毒素+参附组的Toll样受体4、细胞间黏附分子1、E-选择素表达水平、NF-κB活性均明显低于内毒素组。结论参附注射液可以通过抑制NF-κB活化,减弱Toll样受体4/NF-κB途径,抑制了脂多糖介导的黏附分子表达,从而减轻机体的炎症反应。     

Suppression of endothelial cell adhesion by XJP-1, a new phenolic compound derived from banana peel

The adhesion of monocytes to activated vascular endothelial cells is a critical event in the initiation of atherosclerosis. Adhesion is mediated by oxidized low-density lipoprotein (ox-LDL) which up-regulates inflammatory markers on endothelial cells. Here we report that (±) 7, 8-dihydroxy-3-methyl-isochromanone-4 (XJP-1), an inhibitor of ox-LDL-induced adhesion of monocytes to endothelial cells blocks cellular functions which are associated with adhesion. We show that XJP-1 down-regulates ox-LDL-induced over-expression of adhesion molecules (ICAM-1 and VCAM-1) in a dose-dependent manner in human umbilical vein endothelial cells (HUVECs), attenuates ox-LDL-induced up-regulation of low-density lipoprotein receptor (LOX)-1, decreases generation of reactive oxygen species (ROS), blocks translocation of nuclear factor-kappa B (NF-κB) activity, and prevents activation of c-Jun N-terminal kinase (JNK)/p38 pathways in endothelial cells. These findings suggest that XJP-1 may attenuate ox-LDL-induced endothelial adhesion of monocytes by blocking expression of adhesion molecules through suppressing ROS/NF-κB, JNK and p38 pathways.     

姜黄素对溶血磷脂酰胆碱诱导内皮细胞炎症因子产生的影响

目的：观察姜黄素对溶血磷脂酰胆碱（LPC）诱导内皮细胞炎症因子产生的影响,探讨姜黄素抗动脉粥样硬化（AS）的作用机制。方法：体外培养的人脐静脉内皮细胞（HUVECs）,待细胞生长到融合状态时加入不同浓度（25、50、100mg／L）的姜黄素预处理30min,然后加入LPC（5mg／L）作用24h,用酶联免疫吸附法（ELISA）检测上清液中细胞间黏附分子-1（ICAM-1）、单核细胞趋化蛋白-1（MCP-1）、IL-6和TNF-α的含量;实时荧光定量PCR（real-time PCR）检测ICAM—1、MCP-1、IL-6和TNF-α mRNA的表达;蛋白印迹法（Wesiem blot）和免疫细胞化学染色法检测核因子-κBp65（NF-κBp65）蛋白的表达。结果：LPC能明显增加HUVECs ICAM-1、MCP-1、IL-6、TNF-α mRNA和NF-κB p65蛋白的表达以及上清液中ICAM-1、MCP-1、IL-6、TNF-α的含量,而预先应用不同浓度的姜黄素干预后,上述效应明显减弱,并且具有剂量依赖性。结论：姜黄素抑制炎症因子的产生可能与其抑制NF—κB的活性有关。     

Gossypol decreases tumor necrosis factor-α-induced intercellular adhesion molecule-1 expression via suppression of NF-κB activity

Gossypol is a yellowish polyphenolic compound originally from cotton plant, which has been shown to exert a potential for anti-cancer and anti-inflammatory effects. However, its molecular mechanism is not thoroughly understood on breast cancer cells known to highly express intercellular adhesion molecule-1 (ICAM-1) for their adhesion and metastasis. This study aims to investigate the effect of gossypol on tumor necrosis factor (TNF)-α-stimulated ICAM-1 via nuclear factor-kappa B (NF-κB) activity. Gossypol was shown to inhibit TNF-α-induced ICAM-1 expression and U937 cell adhesion to MDA-MB-231 and MCF-7 cells. Additionally, TNF-α-induced MDA-MB-231 cell invasion was blocked in the presence of gossypol. Chromatin immunoprecipitation analysis demonstrated that gossypol blocks NF-κB binding on the ICAM-1 promoter regions. Additionally, TNF-α-induced NF-κB activation was completely suppressed in the presence of gossypol. Gossypol did not directly suppress the binding of NF-κB to the DNA but rather inhibited the nuclear translocation of p65 and p50 via phosphorylation and degradation of IκB. We also found that gossypol suppresses NF-κB activation induced by a wide variety of agents, including taxol, okadaic acid, and phorbol myristate acetate. Taken together, gossypol effectively inhibited TNF-α-induced ICAM-1 expression via the suppression of NF-κB activation and in vitro adhesion and invasion in human breast cancer cells.