Transmigration Of Inflammatory Cells Research Articles

Abstract 15421: Mice Deficient in Endothelial Cell-Selective Adhesion Molecule Display Coronary Microvascular Rarefaction and Left Ventricle Diastolic Dysfunction

Coronary microvascular dysfunction and chronic inflammation play a role in the development of left ventricular diastolic dysfunction (LVDD) in heart failure with preserved ejection fraction (HFpEF). Endothelial cell-selective adhesion molecule (ESAM) is part of the endothelial cell junction complex, which plays a role in the maintenance of cell barrier function, inflammatory cell transmigration and angiogenesis. Here, we examined the role of ESAM in affecting coronary microvascular density and left ventricle diastolic function by employing mice with genetic deletion of ESAM (ESAM -/- ). Using echocardiography, we found that ESAM -/- mice display LVDD, as indicated by a significantly (p<0.05) reduced E/A ratio (E=early, A=late mitral inflow peak velocities), increased E/e’ ratio, isovolumic relaxation time and E wave deceleration time, with no change in the ejection fraction. Using an unbiased, automated tracing and 3D reconstruction of microvascular network revealed that ESAM -/- mice have a reduced coronary microvascular density, which was accompanied by myocardial accumulation of myeloperoxidase-positive neutrophils and elevated myocardial levels of inflammatory cytokines and chemokines. ESAM -/- mice exhibited a reduced endothelial sprout formation in the carotid artery, whereas in cultured endothelial cells siRNA-mediated ESAM knockdown impaired tube formation. Thus, ESAM deficiency in mice leads to coronary microvascular rarefaction, which likely via a myocardial hypoperfusion-related neutrophil accumulation and inflammatory mediator production impairs LV diastolic function.

ω-(5-Phenyl-2H-tetrazol-2-yl)alkyl-substituted hydrazides and related compounds as inhibitors of amine oxidase copper containing 3 (AOC3).

Amine oxidase copper containing 3 (AOC3), also known as plasma amine oxidase, semicarbazide-sensitive amine oxidase, or vascular adhesion protein-1, catalyzes the oxidative deamination of primary amines to aldehydes using copper and a quinone as cofactors. Because it is involved in the transmigration of inflammatory cells through blood vessels into tissues, AOC3 is thought to play an important role in inflammatory diseases. Therefore, inhibitors of this enzyme could lead to new therapeutics for the treatment of inflammation-related diseases. Recently, 6-(5-phenyl-2H-tetrazol-2-yl)hexan-1-amine was found to be a tight-binding substrate of AOC3. To obtain novel inhibitors of the enzyme, the amino group of this substrate was replaced with functional groups that occur in known AOC3 inhibitors, such as hydrazide or glycine amide moieties. In addition, derivatives of the compounds obtained in this way were prepared. The obtained hydrazide 5, which proved to be the most effective, was subjected to further structural modifications. Selected hydrazides were evaluated for selectivity towardsome other amine oxidases.

The Endothelium Is Both a Target and a Barrier of HDL's Protective Functions.

The vascular endothelium serves as a barrier between the intravascular and extravascular compartments. High-density lipoproteins (HDL) have two kinds of interactions with this barrier. First, bloodborne HDL must pass the endothelium to access extravascular tissues, for example the arterial wall or the brain, to mediate cholesterol efflux from macrophages and other cells or exert other functions. To complete reverse cholesterol transport, HDL must even pass the endothelium a second time to re-enter circulation via the lymphatics. Transendothelial HDL transport is a regulated process involving scavenger receptor SR-BI, endothelial lipase, and ATP binding cassette transporters A1 and G1. Second, HDL helps to maintain the integrity of the endothelial barrier by (i) promoting junction closure as well as (ii) repair by stimulating the proliferation and migration of endothelial cells and their progenitor cells, and by preventing (iii) loss of glycocalix, (iv) apoptosis, as well as (v) transmigration of inflammatory cells. Additional vasoprotective functions of HDL include (vi) the induction of nitric oxide (NO) production and (vii) the inhibition of reactive oxygen species (ROS) production. These vasoprotective functions are exerted by the interactions of HDL particles with SR-BI as well as specific agonists carried by HDL, notably sphingosine-1-phophate (S1P), with their specific cellular counterparts, e.g., S1P receptors. Various diseases modify the protein and lipid composition and thereby the endothelial functionality of HDL. Thorough understanding of the structure–function relationships underlying the multiple interactions of HDL with endothelial cells is expected to elucidate new targets and strategies for the treatment or prevention of various diseases.

Crosstalk between Inflammation and the BBB in Stroke.

The blood-brain barrier (BBB), which is located at the interface between the central nervous system (CNS) and the circulatory system, is instrumental in establishing and maintaining the microenvironmental homeostasis of the CNS. BBB disruption following stroke promotes inflammation by enabling leukocytes, T cells and other immune cells to migrate via both the paracellular and transcellular routes across the BBB and to infiltrate the CNS parenchyma. Leukocytes promote the removal of necrotic tissues and neuronal recovery, but they also aggravate BBB injury and exacerbate stroke outcomes, especially after late reperfusion. Moreover, the swelling of astrocyte endfeet is thought to contribute to the ‘no-reflow’ phenomenon observed after cerebral ischemia, that is, blood flow cannot return to capillaries after recanalization of large blood vessels. Pericyte recruitment and subsequent coverage of endothelial cells (ECs) alleviate BBB disruption, which causes the transmigration of inflammatory cells across the BBB to be a dynamic process. Furthermore, interneurons and perivascular microglia also make contacts with ECs, astrocytes and pericytes to establish the neurovascular unit. BBB-derived factors after cerebral ischemia triggered microglial activation. During the later stage of injury, microglia remain associated with brain ECs and contribute to repair mechanisms, including postinjury angiogenesis, by acquiring a protective phenotype, which possibly occurs through the release of microglia-derived soluble factors. Taken together, we reviewed dynamic and bidirectional crosstalk between inflammation and the BBB during stroke and revealed targeted interventions based on the crosstalk between inflammation and the BBB, which will provide novel insights for developing new therapeutic strategies.

Dual Pharmacological Inhibition of Angiopoietin-2 and VEGF-A in Murine Experimental Sepsis

Background: Sepsis is a pathological host response to infection leading to vascular barrier breakdown due to elevated levels of angiopoietin-2 (Angpt-2) and vascular endothelial growth factor-A (VEGF-A). Here, we tested a novel heterodimeric bispecific monoclonal IgG1-cross antibody of Angpt-2 and VEGF – termed “A2V.” Methods: Cecal ligation and puncture was used to induce murine polymicrobial sepsis. Organs and blood were harvested for fluorescence immunohistochemistry and RT-PCR, and survival was recorded. In vitro endothelial cells were stimulated with plasma from septic shock patients costimulated with A2V or IgG antibody followed by immunocytochemistry and real-time transendothelial electrical resistance. Results: Septic mice treated with A2V had a reduced induction of the endothelial adhesion molecule ICAM-1, leading to a trend towards less transmigration of inflammatory cells (A2V: 42.2 ± 1.0 vs. IgG 48.5 ± 1.7 Gr-1⁺ cells/HPF, p = 0.08) and reduced tissue levels of inflammatory cytokines (e.g., IL-6 mRNA: A2V 9.4 ± 3.2 vs. IgG 83.9 ± 36.7-fold over control, p = 0.03). Endothelial permeability was improved in vivo and in vitro in stimulated endothelial cells with septic plasma. Survival was improved by 38% (p = 0.02). Conclusion: Dual inhibition of Angpt-2 and VEGF-A improves murine sepsis morbidity and mortality, making it a potential therapeutic against vascular barrier breakdown.

Euphorbia factor L2 alleviates lipopolysaccharide-induced acute lung injury and inflammation in mice through the suppression of NF-κB activation

Acute respiratory distress syndrome threatens public health with high morbidity and mortality due to ineffective intervention whereby lipopolysaccharide (LPS) induced acute lung injury (ALI) in mice provides a research model. The seeds of Euphorbia lathyris L. have a long history of usage in Traditional Chinese Medicine. Euphorbia factors L1-L11, extracted from this herb, have been reported to have anti-inflammation and anti-cancer effects. Here, we report the preventive and therapeutic potential of Euphorbia factor L2 (EFL2) on LPS-induced ALI in mice, where EFL2 attenuated pathological alterations in the lung and improved survival. Significant suppression of the recruitment and transmigration of inflammatory cells, specifically neutrophils, by 40 mg/kg of EFL2 was observed. EFL2 exerted potent anti-inflammatory effects by decreasing the levels of interleukin-1β (IL-1 β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF- α), interleukin-8 (IL-8) and myeloperoxidase (MPO) in the lung and bronchioalveolar lavage fluid. Consistent with the findings in vivo, EFL2 also showed robust inhibitory effects on the production of IL-1 β, IL-6, TNF- α and IL-8 released from LPS-stimulated RAW264.7 cells in vitro. Interestingly, this effect appeared to be mediated by EFL2’s inhibition of NF-κB signaling activation, but not the MAPK pathway. Not only phosphorylation of IKK α/β and IκBα was down-regulated, p65 translocation and its DNA-binding activity were also significantly suppressed by EFL2. Moreover, overexpression of p65 reversed the inhibitory effect of EFL2 in LPS-induced NF-κB activation and cytokines production. The observed anti-inflammatory bioactivity of EFL2 indicates its potential as a drug development candidate, particularly for LPS-mediated disorders of inflammation.

Clinical Implications

HomeHypertensionVol. 69, No. 3Clinical Implications Free AccessResearch ArticlePDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessResearch ArticlePDF/EPUBClinical Implications Originally published1 Mar 2017https://doi.org/10.1161/HYPERTENSIONAHA.117.09012Hypertension. 2017;69:383IntroductionHypertension in Former Extremely Low Birth Weight Children (p 443)Low birth weight and prematurity are forerunners of hypertension in adulthood. Few studies reported on plasma renin activity in preterm or full-term born children. In prematurely born children with birth weight <1000 g (extremely low birth weight) and healthy controls, we tested the hypothesis whether renin might modulate the pathogenesis of hypertension associated with preterm birth. In cases compared with controls, systolic blood pressure was found to be 7.5 mm Hg higher, but plasma renin activity was found to be 0.54 ng/mL per hour lower. Plasma renin activity decreased with systolic blood pressure but was unrelated to sodium excretion. Extremely low birth weight predisposes young children to a low-renin volume-expanded sodium-sensitive type of hypertension. Extremely low birth weight children might therefore benefit from a life course reduction in salt intake and, if hypertensive, are probably more responsive to diuretics than to inhibitors of the renin–angiotensin system, the currently recommended first-line treatment in children with high blood pressure. Above all, our study highlights the importance of screening for hypertension in all prematurely born infants to avoid the complications associated with high blood pressure later in life. Finally, information on birth weight and on the perinatal history of patients might provide clinically relevant cues to physicians managing hypertension in adults.Download figureDownload PowerPointInterferon Regulatory Factor 3 Modulates Atherosclerosis (p 510)Download figureDownload PowerPointAtherosclerosis is a chronic inflammatory disease in which endothelial dysfunction plays an important role. A major feature of endothelial dysfunction is enhanced adhesion molecule expression, leading to adherence and transmigration of inflammatory cells, including monocytes and macrophages. In this study, we demonstrate that IRF3 (interferon regulatory factor 3) plays an important role in this inflammatory response. IRF3 was found to promote endothelial secretion of vascular cell adhesion molecule-1 and expression of intercellular adhesion molecule-1 by directly binding to its gene promoter. IRF3 was found to be upregulated in endothelial cells in both human and mouse atherosclerotic plaques. Ablation of IRF3 decreased vascular infiltration of macrophages and ameliorated the development of atherosclerosis in apolipoprotein E–deficient mice. IRF3 ablation also improved the stability of atherosclerotic plaques. Because plaque stability is more significant than plaque size in predicting acute clinical events, IRF3 represents a promising target for the treatment of atherogenesis and for prevention of its untoward clinical outcomes.Proton Pump Inhibitors to Treat Preeclampsia (p 457)Preeclampsia is a major complication of pregnancy, responsible for 70 000 maternal deaths annually and far greater fetal losses. A treatment that can quench the disease process could be a major advance, saving the lives of many mothers and babies. Sadly, no treatment exists, except delivery. The preeclamptic placenta releases elevated levels of the antiangiogenic factors sFlt-1 (soluble fms-like tyrosine kinase-1) and soluble endoglin. They disseminate throughout the maternal circulation and cause widespread endothelial dysfunction and hypertension, which then leads to injury to multiple maternal organs. In this issue of Hypertension, Onda et al report preclinical studies showing proton pump inhibitors may have diverse biological effects that make them an unlikely candidate treatment for preeclampsia. Using many functional assays performed on primary human tissues, they show that proton pump inhibitors decrease placental (Figure) and endothelial secretion of sFlt-1 and soluble endoglin, and they decrease endothelial dysfunction. Furthermore, they found that the proton pump inhibitor esomeprazole vasodilates blood vessels isolated from pregnant women and potently decreases blood pressure in a transgenic animal model of preeclampsia where sFlt-1 is overexpressed in the placenta. Proton pump inhibitors are widely prescribed to pregnant women to relieve gastric acid reflux. Large epidemiological studies suggest that proton pump inhibitors are safe to give to pregnant women. Therefore, the exciting clinical implication is that proton pump inhibitors may have the potential to treat or prevent preeclampsia. The team has translated these findings into a phase II placebo-controlled clinical trial to see whether esomeprazole can be used to treat preterm preeclampsia.Download figureDownload PowerPoint Previous Back to top Next FiguresReferencesRelatedDetails March 2017Vol 69, Issue 3 Advertisement Article InformationMetrics © 2017 American Heart Association, Inc.https://doi.org/10.1161/HYPERTENSIONAHA.117.09012 Originally publishedMarch 1, 2017 PDF download Advertisement

HPLC-UV method for evaluation of inhibitors of plasma amine oxidase using derivatization of an aliphatic aldehyde product with TRIS.

Plasma amine oxidase (PAO), which is also designated as semicarbazide-sensitive amine oxidase (SSAO), copper-containing amine oxidase 3 (AOC3), or vascular adhesion protein-1 (VAP-1), catalyzes the oxidative deamination of primary amines to aldehydes using copper and a quinone as cofactors. Because it participates in the transmigration of inflammatory cells through the blood vessels into the tissue, PAO is attributed an important role in inflammatory diseases. Therefore, inhibitors of this enzyme could lead to new therapeutics for the treatment of inflammation-related conditions. Assays for the evaluation of PAO inhibitors usually measure the conversion of benzylamine to benzaldehyde by UVspectroscopy. We have developed a test system with the new substrate 6-(5-phenyl-2H-tetrazol-2-yl)hexan-1-amine, monitoring the formation of the enzyme product 6-(5-phenyl-2H-tetrazol-2-yl)hexanal by reversed phase HPLC with UV detection. Since this compound only eluted with poor peak shape due to hydrate formation in the aqueous mobile phase, it was derivatized with tris(hydroxymethyl)aminomethane (TRIS) under mild conditions to an oxazolidine prior HPLC analysis. The validation of the method revealed that the new substrate was bound with higher affinity to PAO and converted with higher velocity than the standard substrate benzylamine.

Mice with Genetic Deletion of Group VIA Phospholipase A2β Exhibit Impaired Macrophage Function and Increased Parasite Load in Trypanosoma cruzi-Induced Myocarditis.

Trypanosoma cruzi infection, which is the etiological agent of Chagas disease, is associated with intense inflammation during the acute and chronic phases. The pathological progression of Chagas disease is influenced by the infiltration and transmigration of inflammatory cells across the endothelium to infected tissues, which are carefully regulated processes involving several molecular mediators, including adhesion molecules and platelet-activating factor (PAF). We have shown that PAF production is dependent upon calcium-independent group VIA phospholipase A2β (iPLA2β) following infection of human coronary artery endothelial cells (HCAECs) with T. cruzi, suggesting that the absence of iPLA2β may decrease the recruitment of inflammatory cells to the heart to manage parasite accumulation. Cardiac endothelial cells isolated from iPLA2β-knockout (iPLA2β-KO) mice infected withT. cruzi demonstrated decreased PAF production compared to that by cells isolated from wild-type (WT) mice but demonstrated increases in adhesion molecule expression similar to those seen in WT mice. Myocardial inflammation in iPLA2β-KO mice infected with T. cruzi was similar in severity to that in WT mice, but the iPLA2β-KO mouse myocardium contained more parasite pseudocysts. Upon activation, macrophages from iPLA2β-KO mice produced significantly less nitric oxide (NO) and caused lessT. cruzi inhibition than macrophages from wild-type mice. Thus, the absence of iPLA2β activity does not influence myocardial inflammation, but iPLA2β is essential forT. cruzi clearance.

Cytokine release and endothelial dysfunction: a perfect storm in orbivirus pathogenesis.

Although bluetongue viruses (BTV) and epizootic haemorrhagic disease viruses (EHDV) are closely related, there are differences in susceptibility to these viruses both between and within a species. White‑tailed deer are susceptible to disease by both BTV and EHDV, sheep are susceptible to BTV, but resistant to EHDV, and cattle can be infected with both viruses but disease is usually subclinical. Host genetics probably play a role in the disease outcome, but cytokine and endothelial responses are likely to determine if subclinical or clinical disease develops. Dendritic macrophages deliver virus to lymph nodes following the bite of an infected Culicoides. The virus then disseminates to many organs replicating in mononuclear phagocytes and endothelium. Initially, an interferon‑1 response probably determines if the disease develops. Replication in mononuclear cells and endothelium results in the release of cytokines and vasoactive mediators, and may result in endothelial cell death leading to the clinical features of fever, hyperaemia, exudation of fluid, and haemorrhage. Disease outcome may also be linked to virus binding Toll‑like receptor‑3 and upregulation of endothelial surface receptors potentiating cytokine release and allowing transmigration of inflammatory cells, respectively. Despite a wealth of information, host genetics involved in resistance to BTV and EHDV and how variations in cytokines and endothelial responses determine clinical outcome still need further elucidation.

The role of inflammation in cerebral aneurysms

The natural history of unruptured intracranial aneurysms (IAs) is poorly understood. At present, risk factors for aneurysm rupture are limited to demographics and rudimentary anatomic features of the aneurysm. The first sign of aneurysm destabilization and rupture may be subarachnoid hemorrhage, a potentially devastating brain injury with high morbidity and mortality. An emerging body of literature suggests a complex inflammatory cascade likely promotes aneurysm wall remodeling and progressive ballooning of the arterial wall, ultimately terminating in aneurysm rupture. These events likely begin with hemodynamic, flow-related endothelial injury; the injured endothelium stimulates inflammation, including the recruitment and transmigration of inflammatory cells, particularly macrophages. Various proteases are secreted by the inflammatory infiltrate, resulting in degradation of the extracellular matrix and the structural changes unique to IAs. Detailed understanding of these inflammatory processes may result in (1) early identification of patients at high risk for aneurysm rupture, perhaps via arterial wall imaging, and (2) targeted, noninvasive therapies to treat or even prevent cerebral aneurysms.

Hydrogen Sulfide and Endothelial Dysfunction: Relationship with Nitric Oxide

The endothelium is a cellular monolayer that lines the inner surface of blood vessels and plays a central role in the maintenance of cardiovascular homeostasis by controlling platelet aggregation, vascular tone, blood fluidity and fibrinolysis, adhesion and transmigration of inflammatory cells, and angiogenesis. Endothelial dysfunctions are associated with various cardiovascular diseases, including atherosclerosis, hypertension, myocardial infarction, and cardiovascular complications of diabetes. Numerous studies have established the anti-inflammatory, anti-apoptotic, and anti-oxidant effects of hydrogen sulfide (H2S), the latest member to join the gasotransmitter family along with nitric oxide and carbon monoxide, on vascular endothelium. In addition, H2S may prime endothelial cells (ECs) toward angiogenesis and contribute to wound healing, besides to its well-known ability to relax vascular smooth muscle cells (VSMCs), and thereby reducing blood pressure. Finally, H2S may inhibit VSMC proliferation and platelet aggregation. Consistently, a deficit in H2S homeostasis is involved in the pathogenesis of atherosclerosis and of hyperglycaemic endothelial injury. Therefore, the application of H2S-releasing drugs or using gene therapy to increase endogenous H2S level may help restore endothelial function and antagonize the progression of cardiovascular diseases. The present article reviews recent studies on the role of H2S in endothelial homeostasis, under both physiological and pathological conditions, and its putative therapeutic applications.

Cigarette smoke condensate affects monocyte interaction with endothelium

ObjectiveCirculating monocytes adhere to the endothelium and migrate into the intima contributing to atherosclerotic plaque growth. Cigarette smoke is a risk factor for atherosclerosis, but it is not completely known how it affects monocyte behavior in atherogenesis. MethodsWe studied the effects of cigarette smoke condensate (CSC) on human monocytes (HM) chemotaxis and transmigration through an endothelial cell (EC) monolayer. ResultsPre-treatment with CSC caused a decrease in HM chemotaxis and transmigration (−55% and −18% vs control, p < 0.05, respectively), paralleled by a reduced expression of Rac 1 GTPase. On the contrary, direct exposure of both HM and EC to CSC increased (+23% vs control, p < 0.05) HM transmigration, paralleled by a strong stimulation of VCAM1 and ICAM1 expression by ECs, and by a slight increase in monocyte integrin expression. An enhancement of monocyte transmigration was obtained after the exposure of both HM and EC to medium conditioned by HM previously incubated with CSC (+265% vs control, p < 0.001). CSC showed a stimulatory effect on the expression by HM of TLR4, MCP1, IL8, IL1beta, and TNFalfa, which was ablated by pre treatment with PDTC. Incubation with neutralizing antibodies against both MCP1 or IL8 completely abolished the CSC-conditioned medium induced HM transmigration. ConclusionsCSC induces HM to release chemotactic factor(s), which amplify the recruitment and transmigration of inflammatory cells through EC, but CSC may also reduce HM migratory capacity. Therefore, exposure to CSC affects monocyte behavior and interaction with the endothelium, thus potentially facilitating and/or further aggravating the atherogenic process.

Absence of calcium-independent phospholipase A2 β impairs platelet-activating factor production and inflammatory cell recruitment in Trypanosoma cruzi-infected endothelial cells.

Both acute and chronic phases of Trypanosoma cruzi (T. cruzi) infection are characterized by tissue inflammation, mainly in the heart. A key step in the inflammatory process is the transmigration of inflammatory cells across the endothelium to underlying infected tissues. We observed increased arachidonic acid release and platelet‐activating factor (PAF) production in human coronary artery endothelial cells (HCAEC) at up to 96 h of T. cruzi infection. Arachidonic acid release is mediated by activation of the calcium‐independent phospholipase A2 (iPLA2) isoforms iPLA2β and iPLA2γ, whereas PAF production was dependent upon iPLA2β activation alone. Trypanosoma cruzi infection also resulted in increased cell surface expression of adhesion molecules. Increased adherence of inflammatory cells to T. cruzi‐infected endothelium was blocked by inhibition of endothelial cell iPLA2β or by blocking the PAF receptor on inflammatory cells. This suggests that PAF, in combination with adhesion molecules, might contribute to parasite clearing in the heart by recruiting inflammatory cells to the endothelium.

Wnt Activation of Immortalized Brain Endothelial Cells as a Tool for Generating a Standardized Model of the Blood Brain Barrier In Vitro

Reproducing the characteristics and the functional responses of the blood–brain barrier (BBB) in vitro represents an important task for the research community, and would be a critical biotechnological breakthrough. Pharmaceutical and biotechnology industries provide strong demand for inexpensive and easy-to-handle in vitro BBB models to screen novel drug candidates. Recently, it was shown that canonical Wnt signaling is responsible for the induction of the BBB properties in the neonatal brain microvasculature in vivo. In the present study, following on from earlier observations, we have developed a novel model of the BBB in vitro that may be suitable for large scale screening assays. This model is based on immortalized endothelial cell lines derived from murine and human brain, with no need for co-culture with astrocytes. To maintain the BBB endothelial cell properties, the cell lines are cultured in the presence of Wnt3a or drugs that stabilize β-catenin, or they are infected with a transcriptionally active form of β-catenin. Upon these treatments, the cell lines maintain expression of BBB-specific markers, which results in elevated transendothelial electrical resistance and reduced cell permeability. Importantly, these properties are retained for several passages in culture, and they can be reproduced and maintained in different laboratories over time. We conclude that the brain-derived endothelial cell lines that we have investigated gain their specialized characteristics upon activation of the canonical Wnt pathway. This model may be thus suitable to test the BBB permeability to chemicals or large molecular weight proteins, transmigration of inflammatory cells, treatments with cytokines, and genetic manipulation.

Vitamin D Inflammatory Cytokines and Coronary Events: A Comprehensive Review

Myocardial infarction (MI) is the most common cause of cardiac injury in the Western world. Cardiac injury activates innate immune mechanisms initiating an inflammatory reaction. Inflammatory cytokines and vascular cell adhesion molecules (VCAM) promote adhesive interactions between leukocytes and endothelial cells, resulting in the transmigration of inflammatory cells into the site of injury. Low vitamin D levels are associated with higher prevalence of cardiovascular risk factors and a higher risk of MI. In this paper, we examine the effects of short-term vitamin D supplementation on inflammatory cytokine levels after an acute coronary syndrome. We recruited patients arriving to the hospital with an acute MI. All patients received optimal medical therapy and underwent a coronary catheterization. Half of the patients were randomly selected and treated with a daily supplement of vitamin D (4,000 IU) for 5 days. A short course of treatment with vitamin D effectively attenuated the increase in circulating levels of inflammatory cytokines after an acute coronary event. Control group patients had increased cytokine and cellular adhesion molecules serum concentrations after 5 days, while the vitamin D-treated group had an attenuated elevation or a reduction of these parameters. There were significant differences in VCAM-1 levels, C-reactive protein, and interleukin-6. There were trends toward significance in interleukin-8 levels. There were no significant differences in circulating levels of intercellular adhesion molecule 1, E-selectin, vascular endothelial growth factor, and tumor necrosis factor-α. These findings provide information on the anti-inflammatory effects of vitamin D on the vascular system and suggest mechanisms that mediate some of its cardioprotective properties. There is place for further studies involving prolonged vitamin D treatment in patients suffering from ischemic heart disease.

Vascular Endothelial Nitric Oxide, Insulin Signaling and Insulin Transport: A Delicate Balance

Vascular endothelial dysfunction, characterized by a deficiency of bio-available nitric Oxide (NO), has been found to precede the development of type 2 diabetes and is significantly correlated with insulin resistance [1]. Vascular Endothelial Cells (ECs) have pleiotropic functions and regulate a large variety of cellular processes including coagulation, fibrinolysis, angiogenesis, adhesion and transmigration of inflammatory cells and vasculature hemodynamics. Another very important vascular endothelial function is providing a barrier that regulates entry of nutrients and hormones into the interstitium of peripheral tissues [2]. This is particularly true for skeletal muscle, a major site of fuel use, where its continuous vascular endothelium has well-developed junctional structures and abundant caveolae that provides a relatively tight diffusional barrier. This is in stark contrast to the discontinuous endothelium with gaps between ECs in liver. Muscle’s tight endothelium has constituted the structural basis for a strong argument that the transit of insulin from the vascular to the interstitial compartment within skeletal muscle is rate limiting for insulin’s metabolic action [2]. Most importantly, this rate-limiting step for peripheral insulin action is delayed in insulin-resistant obese subjects [3-5]. Current evidence indicates that insulin trans-endothelial transport (TET) is mediated by the molecular transcytotic machinery

Role of Hsp70 in lung inflammation after chronic stress

Circulating monocytes adhere to the endothelium and migrate into the intima contributing to atherosclerotic plaque growth. Cigarette smoke is a risk factor for atherosclerosis, but it is not completely known how it affects monocyte behavior in atherogenesis.We studied the effects of cigarette smoke condensate (CSC) on human monocytes (HM) chemotaxis and transmigration through an endothelial cell (EC) monolayer.Pre-treatment with CSC caused a decrease in HM chemotaxis and transmigration (−55% and −18% vs control, p < 0.05, respectively), paralleled by a reduced expression of Rac 1 GTPase. On the contrary, direct exposure of both HM and EC to CSC increased (+23% vs control, p < 0.05) HM transmigration, paralleled by a strong stimulation of VCAM1 and ICAM1 expression by ECs, and by a slight increase in monocyte integrin expression. An enhancement of monocyte transmigration was obtained after the exposure of both HM and EC to medium conditioned by HM previously incubated with CSC (+265% vs control, p < 0.001). CSC showed a stimulatory effect on the expression by HM of TLR4, MCP1, IL8, IL1beta, and TNFalfa, which was ablated by pre treatment with PDTC. Incubation with neutralizing antibodies against both MCP1 or IL8 completely abolished the CSC-conditioned medium induced HM transmigration.CSC induces HM to release chemotactic factor(s), which amplify the recruitment and transmigration of inflammatory cells through EC, but CSC may also reduce HM migratory capacity. Therefore, exposure to CSC affects monocyte behavior and interaction with the endothelium, thus potentially facilitating and/or further aggravating the atherogenic process.

Cellular Senescence, Vascular Disease, and Aging

> You must remember this, > > A kiss is just a kiss, > > A sigh is just a sigh, > > The fundamental things apply, > > As time goes by. “As Time Goes By,” by Herman Hupfeld, Casablanca (1942)1 The increasing prevalence of older-age people in our society represents the culmination of centuries of medical, scientific, and social endeavors. At least in Western society, now relatively freed from pestilence, abject poverty, gross malnutrition, and polluted water and food sources, an increasing proportion of the population can expect to make it to old age. However, although US age-adjusted death rates from cardiovascular disease, coronary heart disease, and stroke continue to fall, a disproportionate number of people who reach old age (≈80% of people aged ≥80 years) suffer from these diseases.1a In this 2-part review, we consider important pathobiological changes that occur with aging in the cardiovascular system, exploring promising areas of recent scientific progress and novel insights that may be translatable into targeted clinical strategies to help to alleviate the excess morbidity and mortality imposed by cardiovascular disease in the elderly. In this second installment, we focus specifically on vascular disease states of the elderly, including systolic hypertension, vascular calcification, and dementia, and we review relevant basic and clinical discoveries that further elucidate these conditions. ### The Elderly Vascular Phenotype Aging is associated with various changes in the vascular system at differing structural and functional levels. At the macroscopic level, an increase in arterial lumen size and arterial wall thickening, mainly of the intima, are observed.2 In addition, increased vascular calcification and a generalized stiffening of the arterial tree lead to increased arterial wave reflectance, increased systolic blood pressure, decreased diastolic blood pressure, and a widened pulse pressure. An interesting aspect of vascular biology in which significant inroads have been made is our understanding of pulse wave velocity, which …

Diesel exhaust particles modulate vascular endothelial cell permeability: Implication of ZO-1 expression

Exposure to air pollutants increases the incidence of cardiovascular disease. Recent toxicity studies revealed that ultra-fine particles (UFP, d p < 100–200 nm), the major portion of particulate matter (PM) by numbers in the atmosphere, induced atherosclerosis. In this study, we posited that variations in chemical composition in diesel exhausted particles (DEP) regulated endothelial cell permeability to a different extent. Human aortic endothelial cells (HAEC) were exposed to well-characterized DEP ( d p < 100 nm) emitted from a diesel engine in either idling mode (DEP1) or in urban dynamometer driving schedule (UDDS) (DEP2). Horse Radish Peroxidase-Streptavidin activity assay showed that DEP2 increased endothelial permeability to a greater extent than DEP1 (control = 0.077 ± 0.005, DEP1 = 0.175 ± 0.003, DEP2 = 0.265 ± 0.006, n = 3, p < 0.01). DEP2 also down-regulated tight junction protein, Zonular Occludin-1 (ZO-1), to a greater extent compared to DEP1. LDH and caspase-3 activities revealed that DEP-mediated increase in permeability was not due to direct cytotoxicity, and DEP-mediated ZO-1 down-regulation was not due to a decrease in ZO-1 mRNA. Hence, our findings suggest that DEP1 vs. DEP2 differentially influenced the extent of endothelial permeability at the post-translational level. This increase in endothelium permeability is implicated in inflammatory cell transmigration into subendothelial layers with relevance to the initiation of atherosclerosis.