Endothelial cell dysfunction, injury and death

Curcumin Mitigates Malathion-Induced Renal Injury: Suppression of Apoptosis and Modulation of NF-κβ/TNF-α and Nrf2, and HO-1 Signaling

Malathion is one of the most used organophosphorus pesticides that is used for many reasons such as agriculture and industry. Human exposure to malathion may occur through various means, such as eating food that has been treated with it. Malathion not only increases oxidative stress but also decreases the antioxidant capacity. Curcumin is a powerful antioxidant with many pharmacological actions. Curcumin can act as a free radical scavenger and inhibit the activation and nuclear translocation of NF-κB. Curcumin could combat the lipid peroxidation and antioxidant depletion that trigger the apoptotic pathways. This study aims to examine the antioxidant, anti-inflammatory, and antiapoptotic effects of curcumin. Twenty-four Sprague Dawley rats were divided into four groups (six rats each): control, curcumin, malathion, and malathion + curcumin groups. At the assigned time, blood samples were used for the assessment of serum creatinine, and the kidneys were excised and washed; parts of them were used for the assessment of total oxidant status (TOS), oxidative stress index (OSI), the oxidative stress marker malondialdehyde (MDA), total antioxidant capacity (TAC), and glutathione (GSH) activity, other parts were fixed in formalin for further staining. Histopathological evaluation was performed for the fixed specimens after staining with H&E, sirus red, and the immunohistochemical staining for NF-κβ, TNF-α, Caspase-3, Nrf2, and HO-1. Curcumin significantly decreases the serum creatinine after malathion exposure and significantly restores the oxidant/antioxidant balance by increasing TAC and GSH and decreasing TOS, OSI, and MDA. Curcumin exerts its reno-protective effect and restores the histological architecture of the kidney by downregulating the immune expression of NF-κβ, TNF-α, and Caspase-3 and upregulating the expression of Nrf2 and HO-1. This study concluded that curcumin protects against nephrotoxicity caused by malathion by exerting its antioxidant, anti-inflammatory, and anti-apoptotic capabilities.

The protective roles of liraglutide on Kawasaki disease via AMPK/mTOR/NF-κB pathway

Kawasaki disease (KD) is an acute febrile rash illness among children of unknown etiology, with coronary artery injury. The main purpose of this study was to investigate the protective effects of liraglutide on KD, and elucidate the underlying mechanisms. The candida albicans water-soluble fraction (CAWS)-induced coronary arteritis of mouse KD model in vivo and tumor necrosis factor α (TNF-α) induced endothelial cell injury of human umbilical vein endothelial cell (HUVEC) model in vitro were used to explore the anti-inflammation and anti-apoptosis effects of liraglutide on KD. In vivo results showed that liraglutide could significantly alleviate the coronary artery injury of KD mice, as evidenced by the reduction of inflammatory infiltration around the coronary arteries, downregulation of inflammatory cytokines and chemokines expressions, and decrease of TUNEL (Terminal deoxynucleotidyl transferase dUTP nick end labeling) positive cell rates. The results in vitro also displayed that liraglutide could markedly relieve the inflammatory of TNF-α induced HUVECs through downregulating the expressions of inflammatory and chemokine indicators as well as inhibit TNF-α induced HUVEC apoptosis by the less ratio of apoptotic cells, the more loss of mitochondrial membrane potential (△Ψm), the lower level of intracellular reactive oxygen species (ROS), and the more ratio of BCL-2/BAX. Further in vivo and in vitro studies demonstrated that liraglutide could rescue endothelial cell injury through AMPK/mTOR/NF-κB pathway. In conclusion, liraglutide could play protective roles on KD through inhibiting endothelial cell inflammation and apoptosis via the activation of AMPK/mTOR/NF-κB pathway.

Endothelial progenitor cells in the host defense response

Extensive injury of endothelial cells in blood vasculature, especially in the microcirculatory system, frequently occurs in hosts suffering from sepsis and the accompanied systemic inflammation. Pathological factors, including toxic components derived from invading microbes, oxidative stress associated with tissue ischemia/reperfusion, and vessel active mediators generated during the inflammatory response, are known to play important roles in mediating endothelial injury. Collapse of microcirculation and tissue edema developed from the failure of endothelial barrier function in vital organ systems, including the lung, brain, and kidney, are detrimental, which often predict fatal outcomes. The host body possesses a substantial capacity for maintaining vascular homeostasis and repairing endothelial damage. Bone marrow and vascular wall niches house endothelial progenitor cells (EPCs). In response to septic challenges, EPCs in their niche environment are rapidly activated for proliferation and angiogenic differentiation. In the meantime, release of EPCs from their niches into the blood stream and homing of these vascular precursors to tissue sites of injury are markedly increased. The recruited EPCs actively participate in host defense against endothelial injury and repair of damage in blood vasculature via direct differentiation into endothelial cells for re-endothelialization as well as production of vessel active mediators to exert paracrine and autocrine effects on angiogenesis/vasculogenesis. In recent years, investigations on significance of EPCs in host defense and molecular signaling mechanisms underlying regulation of the EPC response have achieved substantial progress, which promotes exploration of vascular precursor cell-based approaches for effective prevention and treatment of sepsis-induced vascular injury as well as vital organ system failure.

Ginseng® Alleviates Malathion-Induced Hepatorenal Injury through Modulation of the Biochemical, Antioxidant, Anti-Apoptotic, and Anti-Inflammatory Markers in Male Rats

This study aims to see if Ginseng^® can reduce the hepatorenal damage caused by malathion. Four groups of forty male Wistar albino rats were alienated. Group 1 was a control group that got orally supplied corn oil (vehicle). Group 2 was intoxicated by malathion dissolved in corn oil orally at 135 mg/kg/day. Group 3 orally received both malathion + Panax Ginseng^® (300 mg/kg/day). Group 4 was orally given Panax Ginseng^® at a 300 mg/kg/day dose. Treatments were administered daily and continued for up to 30 consecutive days. Malathion's toxic effect on both hepatic and renal tissues was revealed by a considerable loss in body weight and biochemically by a marked increase in liver enzymes, LDH, ACP, cholesterol, and functional renal markers with a marked decrease in serum TP, albumin, and TG levels with decreased AchE and Paraoxonase activity. Additionally, malondialdehydes, nitric oxide (nitrite), 8-hydroxy-2-deoxyguanosine, and TNFα with a significant drop in the antioxidant activities were reported in the malathion group. Malathion upregulated the inflammatory cytokines and apoptotic genes, while Nrf2, Bcl2, and HO-1 were downregulated. Ginseng^® and malathion co-treatment reduced malathion's harmful effects by restoring metabolic indicators, enhancing antioxidant pursuit, lowering the inflammatory reaction, and alleviating pathological alterations. So, Ginseng^® may have protective effects against hepatic and renal malathion-induced toxicity on biochemical, antioxidant, molecular, and cell levels.

Endothelial dysfunction in patients with lone atrial fibrillation

BACKGROUND

Atrial fibrillation (AF) is the most common tachyarrhythmia in patients with cardiovascular diseases (CVDs) and may have significant complications such as stroke. The present study aims to evaluate endothelial dysfunction in patients with lone atrial fibrillation (LAF) through flow-mediated dilation (FMD) in the brachial artery, as a non-invasive method for evaluating functional and structural markers of endothelial dysfunction.

METHODS

In this case-control study, 43 patients with LAF were selected. 51 age and sex-matched healthy individuals were selected as the control group. The brachial artery diameter of the subjects in both groups was measured through FMD. The obtained data were analyzed by SPSS software.

RESULTS

Patients with LAF and healthy subjects did not have any difference in terms of gender, heart rate (HR), and systolic blood pressure (SBP) (P > 0.05 for all). FMD of the patients with AF was significantly lower (P = 0.04) than FMD of the healthy controls.

CONCLUSION

Our findings showed that LAF was associated with systemic endothelial dysfunction. AF plays an important and independent role in reducing FMD.

Integrin signaling in atherosclerosis

Atherosclerosis, a chronic lipid-driven inflammatory disease affecting large arteries, represents the primary cause of cardiovascular disease in the world. The local remodeling of the vessel intima during atherosclerosis involves the modulation of vascular cell phenotype, alteration of cell migration and proliferation, and propagation of local extracellular matrix remodeling. All of these responses represent targets of the integrin family of cell adhesion receptors. As such, alterations in integrin signaling affect multiple aspects of atherosclerosis, from the earliest induction of inflammation to the development of advanced fibrotic plaques. Integrin signaling has been shown to regulate endothelial phenotype, facilitate leukocyte homing, affect leukocyte function, and drive smooth muscle fibroproliferative remodeling. In addition, integrin signaling in platelets contributes to the thrombotic complications that typically drive the clinical manifestation of cardiovascular disease. In this review, we examine the current literature on integrin regulation of atherosclerotic plaque development and the suitability of integrins as potential therapeutic targets to limit cardiovascular disease and its complications.

IL-1α-induced microvascular endothelial cells promote neutrophil killing by increasing MMP-9 concentration and lysozyme activity

The recruitment of neutrophils by endothelial cells during infection has been extensively studied, but little is known about the regulation of neutrophils activity by endothelial cells. To examine the role of microvascular endothelial cells in neutrophil killing, we established a transmigration model using rat intestinal microvascular endothelial cells (RIMVECs) and measured the extracellular and intracellular killing of Escherichia coli, Lactobacillus acidophilus, and Staphylococcus aureus by transendothelial neutrophils. We observed that blood neutrophils engulfed bacteria but did not kill them, and lipopolysaccharide- or hemolysin-injured RIMVECs inhibited the extracellular and intracellular bactericidal activity of transendothelial neutrophils. In comparison, interleukin-1α-induced RIMVECs promoted the extracellular and intracellular killing activity of transendothelial neutrophils and significantly increased MMP-9 concentration and lysozyme activity in transendothelial neutrophils (p < 0.01 and p < 0.001, respectively). Our results demonstrated that activation of endothelial cells enhanced bactericidal activity of transendothelial neutrophils and bacterial toxin damage of endothelial cells led to reduction in bactericidal activity of transendothelial neutrophils. These findings offered new insight into the role of endothelial cells in the bactericidal activity of neutrophils.

AIP1-mediated stress signaling in atherosclerosis and arteriosclerosis

AIP1 (ASK1-interacting protein-1; encoded by the DAB2IP gene), a signaling scaffolding protein, is abundantly expressed in vascular endothelial cells (EC). While it was initially discovered as an apoptosis signal-regulating kinase 1 (ASK1)-interacting protein, AIP1 broadly suppresses inflammatory responses triggered by cytokines and stresses such as TNF, LPS, VEGF, and endoplasmic reticulum (ER) stress in EC (therefore, AIP1 is an anti-inflammatory protein). Human genome-wide association study (GWAS) has identified DAB2IP gene variants conferring susceptibility to cardiovascular diseases. Consistently, a global or vascular EC-specific deletion of DAB2IP in mice strongly enhances inflammatory responses and exacerbates atherosclerosis and graft arteriosclerosis progression in mouse models. Mechanisms for AIP1 function and regulation associated with human cardiovascular diseases need further investigations.

Ribosomal and immune transcripts associate with relapse in acquired ADAMTS13-deficient thrombotic thrombocytopenic purpura

Approximately 40% of patients who survive acute episodes of thrombotic thrombocytopenic purpura (TTP) associated with severe acquired ADAMTS13 deficiency experience one or more relapses. Risk factors for relapse other than severe ADAMTS13 deficiency and ADAMTS13 autoantibodies are unknown. ADAMTS13 autoantibodies, TTP episodes following infection or type I interferon treatment and reported ensuing systemic lupus erythematosus in some patients suggest immune dysregulation. This cross-sectional study asked whether autoantibodies against RNA-binding proteins or peripheral blood gene expression profiles measured during remission are associated with history of prior relapse in acquired ADAMTS13-deficient TTP. Peripheral blood from 38 well-characterized patients with autoimmune ADAMTS13-deficient TTP in remission was examined for autoantibodies and global gene expression. A subset of TTP patients (9 patients, 24%) exhibited a peripheral blood gene signature composed of elevated ribosomal transcripts that associated with prior relapse. A non-overlapping subset of TTP patients (9 patients, 24%) displayed a peripheral blood type I interferon gene signature that associated with autoantibodies to RNA-binding proteins but not with history of relapse. Patients who had relapsed bimodally expressed higher HLA transcript levels independently of ribosomal transcripts. Presence of any one potential risk factor (ribosomal gene signature, elevated HLA-DRB1, elevated HLA-DRB5) associated with relapse (OR = 38.4; p = 0.0002) more closely than any factor alone or all factors together. Levels of immune transcripts typical of natural killer (NK) and T lymphocytes positively correlated with ribosomal gene expression and number of prior episodes but not with time since the most recent episode. Flow cytometry confirmed elevated expression of cell surface markers encoded by these transcripts on T and/or NK cell subsets of patients who had relapsed. These data associate elevated ribosomal and immune transcripts with relapse history in acquired, ADAMTS13-deficient TTP.

Cordycepin inhibits lipopolysaccharide (LPS)-induced tumor necrosis factor (TNF)-α production via activating amp-activated protein kinase (AMPK) signaling

Tumor necrosis factor (TNF)-α is elevated during the acute phase of Kawasaki disease (KD), which damages vascular endothelial cells to cause systemic vasculitis. In the current study, we investigated the potential role of cordycepin on TNFα expression in both lipopolysaccharide (LPS)-stimulated macrophages and ex vivo cultured peripheral blood mononuclear cells (PBMCs) of KD patients. We found that cordycepin significantly suppressed LPS-induced TNFα expression and production in mouse macrophages (RAW 264.7 cells and bone marrow-derived macrophages (BMDMs)). Meanwhile, cordycepin alleviated TNFα production in KD patients’ PBMCs. PBMCs from healthy controls had a much lower level of basal TNF-α content than that of KD patients. LPS-induced TNF-α production in healthy controls’ PBMCs was also inhibited by cordycepin. For the mechanism study, we discovered that cordycepin activated AMP-activated protein kinase (AMPK) signaling in both KD patients’ PBMCs and LPS-stimulated macrophages, which mediated cordycepin-induced inhibition against TNFα production. AMPK inhibition by its inhibitor (compound C) or by siRNA depletion alleviated cordycepin’s effect on TNFα production. Further, we found that cordycepin inhibited reactive oxygen species (ROS) production and nuclear factor kappa B (NF-κB) activation in LPS-stimulate RAW 264.7 cells or healthy controls’ PBMCs. PBMCs of KD patients showed higher basal level of ROS and NF-κB activation, which was also inhibited by cordycepin co-treatment. In conclusion, our data showed that cordycepin inhibited TNFα production, which was associated with AMPK activation as well as ROS and NF-κB inhibition. The results of this study should have significant translational relevance in managing this devastating disease.

TNF-α induces endothelial dysfunction via PKC-ζ-dependent NADPH oxidase activation

Endothelial dysfunction is implicated in a variety of cardiovascular diseases although the detailed mechanisms are not yet completely understood. A relationship has been suggested to exist between inflammation and endothelial dysfunction. TNF-α serves as one of the most important pro-inflammatory cytokines. The main objectives of the present study were to explore the effect of PKC-ζ on TNF-α-impaired endothelial function as well as the underlying mechanisms. Acetylcholine-induced endothelium-dependent vasodilation of mouse thoracic aorta stimulated by TNF-α was initially determined. PKC-ζ deficient mice and the specific inhibitor of NADPH oxidase were respectively applied to elucidate their roles in TNF-α-induced endothelial dysfunction. In vitro superoxide generation in HAECs was detected by DHE staining after administration of TNF-α. Meanwhile, the regulatory p47(phox) subunit of NADPH oxidase was evaluated by Western blotting and RT-PCR. The results showed that TNF-α conspicuously impaired endothelium-dependent vasodilation and the impairment was attenuated by either depleting PKC-ζ or inhibiting NADPH oxidase. In vitro TNF-α increased superoxide production and p47(phox) expression in HAECs, and such increases could be ameliorated by the specific PKC-ζ inhibitor. Our findings suggest that superoxide over-production triggered by PKC-ζ-dependent NADPH oxidase activation contributes to TNF-α-induced endothelial dysfunction.

Both internalization and AIP1 association are required for tumor necrosis factor receptor 2-mediated JNK signaling

OBJECTIVE

The proinflammtory cytokine tumor necrosis factor (TNF), primarily via TNF receptor 1 (TNFR1), induces nuclear factor-κB (NF-κB)-dependent cell survival, and c-Jun N-terminal kinase (JNK) and caspase-dependent cell death, regulating vascular endothelial cell (EC) activation and apoptosis. However, signaling by the second receptor, TNFR2, is poorly understood. The goal of this study was to dissect how TNFR2 mediates NF-κB and JNK signaling in vascular EC, and its relevance to in vivo EC function.

METHODS AND RESULTS

We show that TNFR2 contributes to TNF-induced NF-κB and JNK signaling in EC as TNFR2 deletion or knockdown reduces the TNF responses. To dissect the critical domains of TNFR2 that mediate the TNF responses, we examine the activity of TNFR2 mutant with a specific deletion of the TNFR2 intracellular region, which contains conserved domain I, domain II, domain III, and 2 TNFR-associated factor-2-binding sites. Deletion analyses indicate that different sequences on TNFR2 have distinct roles in NF-κB and JNK activation. Specifically, deletion of the TNFR-associated factor-2-binding sites (TNFR2-59) diminishes the TNFR2-mediated NF-κB, but not JNK activation; whereas, deletion of domain II or domain III blunts TNFR2-mediated JNK but not NF-κB activation. Interestingly, we find that the TNFR-associated factor-2-binding sites ensure TNFR2 on the plasma membrane, but the di-leucine LL motif within the domain II and aa338-355 within the domain III are required for TNFR2 internalization as well as TNFR2-dependent JNK signaling. Moreover, domain III of TNFR2 is responsible for association with ASK1-interacting protein-1, a signaling adaptor critical for TNF-induced JNK signaling. While TNFR2 containing the TNFR-associated factor-2-binding sites prevents EC cell death, a specific activation of JNK without NF-κB activation by TNFR2-59 strongly induces caspase activation and EC apoptosis.

CONCLUSIONS

Our data reveal that both internalization and ASK1-interacting protein-1 association are required for TNFR2-dependent JNK and apoptotic signaling. Controlling TNFR2-mediated JNK and apoptotic signaling in EC may provide a novel strategy for the treatment of vascular diseases.

Divergent effects of 17-β-estradiol on human vascular smooth muscle and endothelial cell function diminishes TNF-α-induced neointima formation

Coronary heart disease (CHD) is a condition characterized by increased levels of proinflammatory cytokines, including tumor necrosis factor-α (TNF-α). TNF-α can induce vascular endothelial cell (EC) and smooth muscle cell (SMC) dysfunction, central events in development of neointimal lesions. The reduced incidence of CHD in young women is believed to be due to the protective effects of estradiol (E2). We therefore investigated the effects of TNF-α on human neointima formation and SMC/EC functions and any modulatory effects of E2. Saphenous vein (SV) segments were cultured in the presence of TNF-α (10 ng/ml), E2 (2.5 nM) or both in combination. Neointimal thickening was augmented by incubation with TNF-α, an effect that was abolished by co-culture with E2. TNF-α increased SV-SMC proliferation in a concentration-dependent manner that was optimal at 10 ng/ml (1.5-fold increase), and abolished by E2 at all concentrations studied (1-50 nM). Surprisingly, E2 itself at low concentrations (1 and 5 nM) stimulated SV-SMC proliferation to a level comparable to that of TNF-α alone. SV-EC migration was significantly impaired by TNF-α (42% of control), and co-culture with E2 partially restored the ability of SV-EC to migrate and repair the wound. In contrast, TNF-α increased SV-SMC migration by 1.7-fold, an effect that was completely reversed by co-incubation with E2. Finally, TNF-α potently induced ICAM-1 and VCAM-1 expression in both SV-EC and SV-SMC. However there was no modulation by E2 in either cell-type. In conclusion, TNF-α induced SV neointima formation, increased SMC proliferation and migration, impaired SV-EC migration and increased expression of adhesion molecules. E2 exerted distinct cell-type and function-specific modulation, the mechanisms underlying which are worthy of further detailed study.

Hyperglycemia and endothelial dysfunction in atherosclerosis: lessons from type 1 diabetes

A clear relationship between diabetes and cardiovascular disease has been established for decades. Despite this, the mechanisms by which diabetes contributes to plaque formation remain in question. Some of this confusion derives from studies in type 2 diabetics where multiple components of metabolic syndrome show proatherosclerotic effects independent of underlying diabetes. However, the hyperglycemia that defines the diabetic condition independently affects atherogenesis in cell culture systems, animal models, and human patients. Endothelial cell biology plays a central role in atherosclerotic plaque formation regulating vessel permeability, inflammation, and thrombosis. The current paper highlights the mechanisms by which hyperglycemia affects endothelial cell biology to promote plaque formation.

Effects of down-regulation of microRNA-23a on TNF-α-induced endothelial cell apoptosis through caspase-dependent pathways

AIMS

Endothelial cell injury induced by inflammatory factors plays a critical role in the pathogenesis of numerous vascular diseases. MicroRNAs are well known to be implicated in cell proliferation and apoptosis in inflammatory responses; however, it remains to be determined whether microRNAs are associated with tumour necrosis factor (TNF)-α-mediated endothelial cell injury. The aim of the present study was to investigate the role of microRNAs in TNF-α-induced endothelial cell apoptosis.

METHODS AND RESULTS

Microarrays were used to analyse the global expression of microRNAs in TNF-α-stimulated human primary endothelial cells. Expression profiles of the microRNAs were verified using qRT-PCR. After TNF-α treatment, 12 miRNAs were dramatically up-regulated and nine were down-regulated. LNA-anti-miR-23a and pre-miR-23a were found to modulate one of the markedly down-regulated miRNAs, miR-23a, which could in turn increase or attenuate TNF-α-induced endothelial cell apoptosis. Bioinformatics analysis suggested that caspase-7 and serine/threonine kinase 4 are potential targets of miR-23a. LNA-anti-miR-23a enhanced but pre-miR-23a inhibited the activation of caspase-7, serine/threonine kinase 4, and its related signalling caspase-3 after TNF-α treatment; however, neither pre-miR-23a nor LNA-anti-miR-23a had an effect on TNF-α-induced Bcl-2 activation.

CONCLUSION

Our results suggest that miR-23a may be involved in TNF-α-induced endothelial cell apoptosis through regulation of the caspase-7 and serine/threonine kinase 4-caspase-3 pathways.

MEK5 is activated by shear stress, activates ERK5 and induces KLF4 to modulate TNF responses in human dermal microvascular endothelial cells

OBJECTIVE

ECs lining arteries respond to LSS by suppressing pro-inflammatory changes, in part through the activation of MEK5, ERK5 and induction of KLF4. We examined if this anti-inflammatory pathway operates in human ECs lining microvessels, the principal site of inflammatory responses.

METHODS

We used immunofluorescence microscopy of human skin to assess ERK5 activation and KLF4 expression in HDMECs in situ. We applied LSS to or overexpressed MEK5/CA in cultured HDMECs and assessed gene expression by microarrays and qRT-PCR and protein expression by Western blotting. We assessed effects of MEK5/CA on TNF responses using qRT-PCR, FACS and measurements of HDMEC monolayer electrical resistance. We used siRNA knockdown to assess the role of ERK5 and KLF4 in these responses.

RESULTS

ERK5 phosphorylation and KLF4 expression is observed in HDMECs in situ. LSS activates ERK5 and induces KLF4 in cultured HDMECs. MEK5/CA-transduced HDMECs show activated ERK5 and increased KLF4, thrombomodulin, eNOS, and ICAM-1 expression. MEK5 induction of KLF4 is mediated by ERK5. MEK5/CA-transduced HDMECs are less responsive to TNF, an effect partly mediated by KLF4.

CONCLUSIONS

MEK5 activation by LSS inhibits inflammatory responses in microvascular ECs, in part through ERK5-dependent induction of KLF4.

Circulating cytokines, chemokines and adhesion molecules in normal pregnancy and preeclampsia determined by multiplex suspension array

BACKGROUND

Preeclampsia is a severe complication of pregnancy characterized by an excessive maternal systemic inflammatory response with activation of both the innate and adaptive arms of the immune system. Cytokines, chemokines and adhesion molecules are central to innate and adaptive immune processes. The purpose of this study was to determine circulating levels of cytokines, chemokines and adhesion molecules in normal pregnancy and preeclampsia in a comprehensive manner, and to investigate their relationship to the clinical features and laboratory parameters of the study participants, including markers of overall inflammation (C-reactive protein), endothelial activation (von Willebrand factor antigen) and endothelial injury (fibronectin), oxidative stress (malondialdehyde) and trophoblast debris (cell-free fetal DNA).

RESULTS

Serum levels of interleukin (IL)-1beta, IL-1 receptor antagonist (IL-1ra), IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p40, IL-12p70, IL-18, interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, transforming growth factor (TGF)-beta1, interferon-gamma-inducible protein (IP)-10, monocyte chemotactic protein (MCP)-1, intercellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1 were measured in 60 preeclamptic patients, 60 healthy pregnant women and 59 healthy non-pregnant women by multiplex suspension array and ELISA. In normal pregnancy, the relative abundance of circulating IL-18 over IL-12p70 and the relative deficiency of the bioactive IL-12p70 in relation to IL-12p40 might favour Th2-type immunity. Although decreased IL-1ra, TNF-alpha and MCP-1 concentrations of healthy pregnant relative to non-pregnant women reflect anti-inflammatory changes in circulating cytokine profile, their decreased serum IL-10 and increased IP-10 levels might drive pro-inflammatory responses. In addition to a shift towards Th1-type immunity (expressed by the increased IL-2/IL-4 and IFN-gamma/IL-4 ratios), circulating levels of the pro-inflammatory cytokines IL-6 and TNF-alpha, the chemokines IL-8, IP-10 and MCP-1, as well as the adhesion molecules ICAM-1 and VCAM-1, were raised in preeclampsia compared with healthy pregnancy, resulting in an overall pro-inflammatory systemic environment. Increased IP-10, MCP-1, ICAM-1 and VCAM-1 concentrations of preeclamptic patients showed significant correlations with blood pressure values, renal and liver function parameters, as well as with CRP, malondialdehyde, von Willebrand factor antigen and fibronectin levels.

CONCLUSIONS

According to our findings, preeclampsia was associated with an overall pro-inflammatory systemic environment. Elevated amounts of pro-inflammatory cytokines, chemokines and adhesion molecules in the maternal circulation might play a central role in the excessive systemic inflammatory response, as well as in the generalized endothelial dysfunction characteristics of the maternal syndrome of preeclampsia.

Combination of human tumor necrosis factor-alpha (hTNF-alpha) gene delivery with gemcitabine is effective in models of pancreatic cancer

Pancreatic adenocarcinoma is an aggressive and highly lethal malignancy. Currently, gemcitabine is commonly used in patients with pancreatic cancer. However, the life expectancy of pancreatic cancer patients remains poor. We explored the possibility of increased anti-tumor activity by combining human tumor necrosis factor-alpha (hTNF-alpha) with current front-line therapy. Human TNF-alpha displays potent anti-tumor activity, but its use is limited by the toxicity of systemic administration. We developed a gene delivery approach using intratumoral injections of an adenoviral vector expressing hTNF-alpha, AdEgr.TNF.11D (TNFerade), to increase local concentrations of hTNF-alpha within the tumor, thereby maximizing local anti-tumor activity and yet minimizing the systemic toxicities. An ongoing phase III clinical trial is testing the efficacy of AdEgr.TNF.11D-injected intratumorally and combining with chemotherapy in locally advanced pancreatic cancer. In this study, we show that treatment with AdEgr.TNF.11D and gemcitabine results in a high level of hTNF-alpha expression in human pancreatic cancer cell lines. The combined treatment was well tolerated, highly active and produced marked delays in the growth of human pancreatic xenograft tumors relative to either agent alone. Our results strongly suggest that combination of AdEgr.TNF.11D and gemcitabine may be a potentially useful therapeutic approach for the improved treatment of pancreatic cancer.

Chemical modulators of sphingosine-1-phosphate receptors as barrier-oriented therapeutic molecules

Biological barriers regulate the passage of cells, pathogens, fluids, nutrients, ions and signalling molecules between anatomical compartments during homeostasis and disease. Yet strategies that allow for reversible therapeutic modulation of these barriers are still in their infancy. The enhancement or protection of natural barriers is desirable in conditions such as acute respiratory distress syndrome or ischaemia-reperfusion injuries, whereas a temporary disruption could facilitate the penetration of drugs across such barriers. This Review discusses the role of sphingosine-1-phosphate receptors in the regulation and protection of biological barriers, and the potential of therapeutic strategies that target this receptor family.

Endothelial-specific expression of mitochondrial thioredoxin promotes ischemia-mediated arteriogenesis and angiogenesis

OBJECTIVE

Thioredoxin-2 (Trx2), a major antioxidant protein in mitochondria, enhances nitric oxide bioavailability and inhibits ASK1-dependent apoptosis in endothelial cells (ECs). However, the in vivo role of Trx2 in angiogenesis has not been defined. Here we used EC-specific transgenesis of Trx2 (Trx2-TG) in mice to determine the in vivo function of Trx2 in arteriogenesis and angiogenesis.

METHODS AND RESULTS

In a femoral artery ligation model, Trx2-TG mice had enhanced capacity in limb perfusion recovery and ischemic reserve capacity compared to the nontransgenic littermates. Ischemia-initiated arteriogenesis in the upper limb was augmented in Trx2-TG mice. Trx2-TG mice also showed significantly enhanced capillary formation and maturation in the lower limb. In nontransgenic limb, ischemia specifically induced a downregulation of Trx2 protein, leading to increased oxidative stress, ASK1 activation, and EC apoptosis. In contrast, Trx2-TG maintained a constitutive level of Trx2, reducing the ischemia-induced deleterious responses. We then defined the mechanism by which Trx2 increases angiogenesis using ECs isolated from Trx2-TG mice. Trx2-TG ECs showed increased NO and NO-dependent migration. In addition, these cells were more resistant to oxidative stress-induced activation of ASK1 signaling and apoptosis. Moreover, Trx2-augmented EC survival is NO-independent. To define the relative contributions of Trx2-increased NO and Trx2-reduced ASK1 apoptotic activity to angiogenesis in vivo, we examined Trx2 effects on ischemia-induced angiogenesis in eNOS-deficient mice. The eNOS deletion caused severe impairment in the functional flow recovery in response to ischemia. Trx2 expression in eNOS-KO mice still dramatically inhibited ischemia-induced ASK1 and EC apoptosis, leading to an enhanced functional flow recovery.

CONCLUSIONS

These in vivo and in vitro data support that Trx2 maintains EC function by two parallel pathways-scavenging ROS to increase NO bioavailability and inhibiting ASK1 activity to enhance EC survival, facilitating ischemia-mediated arteriogenesis and angiogenesis.

Role of Reactive Oxygen Species in Tumor Necrosis Factor-alpha Induced Endothelial Dysfunction

Endothelial cell injury and dysfunction are the major triggers of pathophysiological processes leading to cardiovascular disease. Endothelial dysfunction (ED) has been implicated in atherosclerosis, hypertension, coronary artery disease, vascular complications of diabetes, chronic renal failure, insulin resistance and hypercholesterolemia. Although now recognized as a class of physiological second messengers, reactive oxygen species (ROS) are important mediators in cellular injury, specifically, as a factor in endothelial cell damage. Uncontrolled ROS production and/or decreased antioxidant activity results in a deleterious state referred to as 'oxidative stress'. A candidate factor in causing ROS production in endothelial cells is tumor necrosis factor alpha (TNF-α), a pleiotropic inflammatory cytokine. TNF-α has been shown to both be secreted by endothelial cells and to induce intracellular ROS formation. These observations provide a potential mechanism by which TNF-α may activate and injure endothelial cells resulting in ED. In this review, we focus on the relationship between intracellular ROS formation and ED in endothelial cells or blood vessels exposed to TNF-α to provide insight into the role of this important cytokine in cardiovascular disease.

Association between tumor necrosis factor (TNF)-alpha G-308A gene polymorphism and preeclampsia complicated by severe fetal growth restriction

BACKGROUND

Preeclampsia and HELLP (hemolysis, elevated liver enzymes, and low platelet count) syndrome are multifactorial disorders with genetic and environmental components. Given that the tumor necrosis factor (TNF)-alpha G-308A single nucleotide polymorphism (SNP) affects TNF-alpha gene transcription and that preeclampsia and HELLP syndrome are characterized by a shift towards a Th1-type maternal immune response with increased TNF-alpha production, the aim of the current study was to investigate whether this SNP is associated with preeclampsia and HELLP syndrome in a Caucasian population from Hungary. Additionally, we aimed to examine whether TNF-alpha G-308A polymorphism can influence the risk for fetal growth restriction in preeclamptic patients, which issue none of the earlier studies dealt with.

METHODS

In a case-control study, we analyzed blood samples from 140 preeclamptic patients, 69 patients with HELLP syndrome and 144 normotensive, healthy pregnant women using the polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) method. We performed also a meta-analysis with our results and those of 8 previously published studies.

RESULTS

There were no significant differences in the genotype and allele frequencies of the TNF-alpha G-308A polymorphism between preeclamptic patients and normotensive, healthy pregnant women. However, the mutant (TNF2 or A) allele occurred significantly more frequently in preeclamptic patients with IUGR than in those without IUGR (18.5% versus 7.1%, p=0.003). In addition, the frequency of the mutant allele carriers was significantly higher among preeclamptic patients with IUGR compared to those without IUGR (30.6% versus 12.8%, p=0.010). The mutant allele carriers were found to have an increased risk of severe IUGR-complicated preeclampsia, which was independent of maternal age, prepregnancy BMI and primiparity (odds ratio (OR): 2.89, 95% confidence interval (CI): 1.16-7.22, p=0.023; adjusted OR: 2.78, 95% CI: 1.04-7.45, p=0.042). Nevertheless, no significant differences were detected in the genotype and allele frequencies of the TNF-alpha G-308A polymorphism between patients with HELLP syndrome and control subjects. In the meta-analysis, no association was observed between this SNP and preeclampsia (summary OR: 0.956, 95% CI: 0.693-1.319).

CONCLUSIONS

Although the meta-analysis demonstrated a lack of an overall association between TNF-alpha G-308A polymorphism and preeclampsia, our results suggest a role of this SNP in the risk of severe IUGR-complicated preeclampsia. However, further studies are required with a larger sample size to confirm our findings.

Adiponectin suppresses IkappaB kinase activation induced by tumor necrosis factor-alpha or high glucose in endothelial cells: role of cAMP and AMP kinase signaling

Adiponectin is a protein secreted from adipocytes that exhibits salutary effects in the vascular endothelium by signaling mechanisms that are not well understood. In obesity-related disease states and type 2 diabetes, circulating substances, including tumor necrosis factor-alpha (TNFalpha) and high glucose, activate IkappaB kinase (IKK)beta and reduce the abundance of its substrate, inhibitor of kappaB (IkappaB)alpha, leading to nuclear translocation of the transcription factor NF-kappaB and stimulation of an inflammatory signaling cascade closely associated with endothelial dysfunction. The present study demonstrates that the globular domain of adiponectin (gAd) potently suppresses the activation of IKKbeta by either TNFalpha or high glucose in human umbilical vein endothelial cells and ameliorates the associated loss of IkappaBalpha protein. Interestingly, activation of AMP kinase was substantially more effective than cAMP signaling in suppressing high glucose-induced IKKbeta activity, whereas both pathways were comparably active in suppressing the TNFalpha-induced increase in IKKbeta. Both cAMP/protein kinase A signaling and activation of the AMP kinase pathway played a role in the suppression by gAd of TNFalpha- and high glucose-mediated IKKbeta activation. These findings support an important role for adiponectin in anti-inflammatory signaling in the endothelium and also imply that multiple pathways are involved in the cellular effects of adiponectin.

Protective effects of ginsenoside Rb1, ginsenoside Rg1, and notoginsenoside R1 on lipopolysaccharide-induced microcirculatory disturbance in rat mesentery

Ginsenoside Rb1 (Rb1), ginsenoside Rg1 (Rg1), and notoginsenoside R1 (R1) are major active components of Panax notoginseng, a Chinese herb that is widely used in traditional Chinese medicine to enhance blood circulation and dissipate blood stasis. To evaluate the effect of these saponins on microcirculatory disturbance induced by lipopolysaccharide (LPS), vascular hemodynamics in rat mesentery was observed continuously during their administration using an inverted microscope and a high speed video camera system. LPS administration decreased red blood cell velocity but Rb1, Rg1, and R1 attenuated this effect. LPS administration caused leukocyte adhesion to the venular wall, mast cell degranulation, and the release of cytokines. Rb1, Rg1, and R1 reduced the number of adherent leukocytes, and inhibited mast cell degranulation and cytokine elevation. In vitro experiments using flow cytometry further demonstrated that a) the LPS-enhanced expression of CD11b/CD18 by neutrophils was significantly depressed by Rb1 and R1, and b) hydrogen peroxide (H(2)O(2)) release from neutrophils in response to LPS stimulation was inhibited by treatment with Rg1 and R1. These results suggest that the protective effect of Rb1 and R1 against leukocyte adhesion elicited by LPS may be associated with their suppressive action on the expression of CD11b/CD18 by neutrophils. The protective effect against mast cell degranulation by Rb1 and R1, and the blunting of H(2)O(2) release from neutrophils by Rg1 and R1 suggest mechanistic diversity in the effects of Panax notoginseng saponins in the attenuation of microcirculatory disturbance induced by LPS.