Atherosclerosis as Inflammation

Evaluation of Oxidative Stress and Inflammatory Biomarkers Pre and Post-Treatment in New Diagnosed Atherosclerotic Patients

Atherosclerosis is a chronic vascular inflammatory disease associated to oxidative stress and endothelial dysfunction. It is characterized by lipid accumulation in the arterial wall, increased hyperlipidemia, oxidative stress, lipid peroxidation, and protein oxidation. Our study included 45 patients ages of 40-60 and 45 healthy volunteers with similar demographic characteristics without any chronic disease as well. Fasting plasma glucose, BUN, creatinine, LDL-cholesterol, HDL-cholesterol, triglyceride, total cholesterol, HbA1c, and C-reactive protein (CRP) levels were measured using commercial kits by autoanalyzer. The oxidative stress biomarkers total oxidant status (TOS), total antioxidant status (TAS), total thiol (TT), native thiol (NT), catalase (CAT), paraoxonase (PON1), and arylesterase (ARES) enzyme activities were measured using photometric methods. The inflammatory biomarkers interleukin 1 beta (IL-1β), tumor necrosis factor-α (TNF-α), presepsin (PSPN), and raftlin (RFTN1) levels were measured with ELISA Kits. Oxidative stress index (OSI) and disulfide (DIS) were calculated. The clinical, biochemical biomarkers such as BUN, creatinine, HDL, LDL, total cholesterol, triglyceride, and CRP levels were found to be higher than the control group and lower post-treatment compared to the pre-treatment group (p <0.001). The oxidative stress parameters, TOS, OSI, and DIS levels were found to be higher than the control group, and the levels before the treatment were statistically significantly higher than after the treatment (p < 0.001). Antioxidant biomarkers TAS, TT, and NT levels were low in the patient group. Inflammatory biomarkers were highest before treatment and decreased with treatment. Oxidative stress and inflammation, which increased in atherosclerosis patients may guide disease prognosis and treatment strategies.

The role of bone morphogenetic protein signaling in vascular calcification

Vascular calcification is associated with atherosclerosis, chronic kidney disease, and diabetes, and results from processes resembling endochondral or intramembranous ossification, or from processes that are distinct from ossification. Bone morphogenetic proteins (BMP), as well as other ligands, receptors, and regulators of the transforming growth factor beta (TGFβ) family regulate vascular and valvular calcification by modulating the phenotypic plasticity of multipotent progenitor lineages associated with the vasculature or valves. While osteogenic ligands BMP2 and BMP4 appear to be both markers and drivers of vascular calcification, particularly in atherosclerosis, BMP7 may serve to protect against calcification in chronic kidney disease. BMP signaling regulators such as matrix Gla protein and BMP-binding endothelial regulator protein (BMPER) play protective roles in vascular calcification. The effects of BMP signaling molecules in vascular calcification are context-dependent, tissue-dependent, and cell-type specific. Here we review the current knowledge on mechanisms by which BMP signaling regulates vascular calcification and the potential therapeutic implications.

Bioactive Compounds of Edible Fruits with Their Anti-Aging Properties: A Comprehensive Review to Prolong Human Life

Aging is a complicated biological process in which functional and structural alterations in a living organism take place over time. Reactive oxygen species is one of the main factors responsible for aging and is associated with several chronic pathologies. The relationship between aging and diet is quite interesting and has attained worldwide attention. Healthy food, in addition to dietary antioxidants, are required to delay the process of aging and improve the quality of life. Many healthy foods such as fruits are a good source of dietary nutrients and natural bioactive compounds which have antioxidant properties and are involved in preventing aging and other age-related disorders. Health benefits linked with healthy consumption of fruit have drawn increased interest. A significant number of studies have documented the advantages of fruit intake, as it suppresses free-radical development that further reduces the oxidative stress created in the body and protects against several types of diseases such as cancer, type 2 diabetes, inflammatory disorders, and other cardiovascular diseases that ultimately prevent aging. In addition, fruits have numerous other properties like anti-inflammatory, anti-cancerous, anti-diabetic, neuroprotective, and have health-promoting effects. Mechanisms of various bioactive compounds that aids in preventing various diseases and increases longevity are also described. This manuscript provides a summary of various bioactive components present in fruits along with their health-promoting and antiaging properties.

Punicalagin Regulates Key Processes Associated with Atherosclerosis in THP-1 Cellular Model

Atherosclerosis may lead to cardiovascular diseases (CVD), which are the primary cause of death globally. In addition to conventional therapeutics for CVD, use of nutraceuticals that prevents cholesterol deposition, reduce existing plaques and hence anti-atherosclerotic effects of nutraceuticals appeared to be promising. As such, in the present study we evaluated the beneficial effects of punicalagin, a phytochemical against an atherosclerotic cell model in vitro. Cytotoxicity assays were examined for 10 µM concentration of punicalagin on THP-1 macrophages. Real-time-polymerase chain reaction (RT-PCR) was used to analyze monocyte chemoattractant protein-1 (MCP-1) and Intercellular adhesion molecule (ICAM-1) expressions. Monocyte migration and cholesterol efflux assays were performed to investigate punicalagin's further impact on the key steps of atherosclerosis. Cytotoxicity assays demonstrated no significant toxicity for punicalagin (10 µM) on THP-1 macrophages. Punicalagin inhibited the IFN-γ-induced overexpression of MCP-1 and ICAM-1 in macrophages by 10 fold and 3.49 fold, respectively, compared to the control. Punicalagin also reduced the MCP-1- mediated migration of monocytes by 28% compared to the control. Percentages of cellular cholesterol efflux were enhanced in presence or absence of IFN-γ by 88% and 84% compared to control with 58 %and 62%, respectively. Punicalagin possesses anti-inflammatory and anti-atherosclerotic effects. Punicalagin also did not exhibit any cytotoxicity and therefore can be considered a safe and potential candidate for the treatment and prevention of atherosclerosis.

Follistatin-like 1 in Cardiovascular Disease and Inflammation

Follistatin-like 1 (FSTL1), a secreted glycoprotein, has been shown to participate in regulating developmental processes and to be involved in states of disease and injury. Spatiotemporal regulation and posttranslational modifications contribute to its specific functions and make it an intriguing candidate to study disease mechanisms and potentially develop new therapies. With cardiovascular diseases as the primary cause of death worldwide, clarification of mechanisms underlying cardiac regeneration and revascularization remains essential. Recent findings on FSTL1 in both acute coronary syndrome and heart failure emphasize its potential as a target for cardiac regenerative therapy. With this review, we aim to shed light on the role of FSTL1 specifically in cardiovascular disease and inflammation.

Therapeutic Potential of Oxytocin in Atherosclerotic Cardiovascular Disease: Mechanisms and Signaling Pathways

Coronary artery disease (CAD) is a major cardiovascular disease responsible for high morbidity and mortality worldwide. The major pathophysiological basis of CAD is atherosclerosis in association with varieties of immunometabolic disorders that can suppress oxytocin (OT) receptor (OTR) signaling in the cardiovascular system (CVS). By contrast, OT not only maintains cardiovascular integrity but also has the potential to suppress and even reverse atherosclerotic alterations and CAD. These protective effects of OT are associated with its protection of the heart and blood vessels from immunometabolic injuries and the resultant inflammation and apoptosis through both peripheral and central approaches. As a result, OT can decelerate the progression of atherosclerosis and facilitate the recovery of CVS from these injuries. At the cellular level, the protective effect of OT on CVS involves a broad array of OTR signaling events. These signals mainly belong to the reperfusion injury salvage kinase pathway that is composed of phosphatidylinositol 3-kinase-Akt-endothelial nitric oxide synthase cascades and extracellular signal-regulated protein kinase 1/2. Additionally, AMP-activated protein kinase, Ca²⁺/calmodulin-dependent protein kinase signaling and many others are also implicated in OTR signaling in the CVS protection. These signaling events interact coordinately at many levels to suppress the production of inflammatory cytokines and the activation of apoptotic pathways. A particular target of these signaling events is endoplasmic reticulum (ER) stress and mitochondrial oxidative stress that interact through mitochondria-associated ER membrane. In contrast to these protective effects and machineries, rare but serious cardiovascular disturbances were also reported in labor induction and animal studies including hypotension, reflexive tachycardia, coronary spasm or thrombosis and allergy. Here, we review our current understanding of the protective effect of OT against varieties of atherosclerotic etiologies as well as the approaches and underlying mechanisms of these effects. Moreover, potential cardiovascular disturbances following OT application are also discussed to avoid unwanted effects in clinical trials of OT usages.

Autoimmunity and autoinflammation: A systems view on signaling pathway dysregulation profiles

INTRODUCTION

Autoinflammatory and autoimmune disorders are characterized by aberrant changes in innate and adaptive immunity that may lead from an initial inflammatory state to an organ specific damage. These disorders possess heterogeneity in terms of affected organs and clinical phenotypes. However, despite the differences in etiology and phenotypic variations, they share genetic associations, treatment responses and clinical manifestations. The mechanisms involved in their initiation and development remain poorly understood, however the existence of some clear similarities between autoimmune and autoinflammatory disorders indicates variable degrees of interaction between immune-related mechanisms.

METHODS

Our study aims at contributing to a holistic, pathway-centered view on the inflammatory condition of autoimmune and autoinflammatory diseases. We have evaluated similarities and specificities of pathway activity changes in twelve autoimmune and autoinflammatory disorders by performing meta-analysis of publicly available gene expression datasets generated from peripheral blood mononuclear cells, using a bioinformatics pipeline that integrates Self Organizing Maps and Pathway Signal Flow algorithms along with KEGG pathway topologies.

RESULTS AND CONCLUSIONS

The results reveal that clinically divergent disease groups share common pathway perturbation profiles. We identified pathways, similarly perturbed in all the studied diseases, such as PI3K-Akt, Toll-like receptor, and NF-kappa B signaling, that serve as integrators of signals guiding immune cell polarization, migration, growth, survival and differentiation. Further, two clusters of diseases were identified based on specifically dysregulated pathways: one gathering mostly autoimmune and the other mainly autoinflammatory diseases. Cluster separation was driven not only by apparent involvement of pathways implicated in adaptive immunity in one case, and inflammation in the other, but also by processes not explicitly related to immune response, but rather representing various events related to the formation of specific pathophysiological environment. Thus, our data suggest that while all of the studied diseases are affected by activation of common inflammatory processes, disease-specific variations in their relative balance are also identified.

Moyamoya and Inflammation

BACKGROUND

More than 50 years have elapsed since moyamoya disease was initially described; however, the disease etiology remains unknown. Although certain genetic loci and immunologic characteristics are associated with moyamoya disease, this does not fully explain its pathophysiology. An association with inflammatory disease has been postulated but not rigorously explored. We sought to examine the epidemiologic association of moyamoya and inflammatory diseases by analyzing data from a large administrative database.

METHODS

The National Inpatient Sample database for 2009-2012 was obtained. The diagnoses of moyamoya disease and inflammatory diseases were made using the International Classification of Disease, 9th revision. Sample prevalence, sex, age, and admission type were recorded. Patients were grouped into inflammatory disease clusters on the basis of the presence of diagnosis codes for atherosclerotic, adult-onset autoimmune, and juvenile-onset autoimmune diseases.

RESULTS

There were 2633 total admissions for moyamoya disease. Atherosclerotic (P < 0.05) and juvenile-onset autoimmune disease (P < 0.05) were associated with moyamoya disease in both pediatric and adult patient groups. Adult-onset autoimmune disease was associated with moyamoya disease in pediatric (P < 0.05) but not adult groups.

CONCLUSION

Moyamoya is associated with inflammatory disease clusters in both pediatric and adult populations. Further studies are warranted to investigate the pathophysiologic association between moyamoya disease and inflammatory disease processes.

Real-Time Intravascular Ultrasound and Photoacoustic Imaging

Combined intravascular ultrasound and intravascular photoacoustic (IVUS/IVPA) imaging is an emerging hybrid modality being explored as a means of improving the characterization of atherosclerotic plaque anatomical and compositional features. While initial demonstrations of the technique have been encouraging, they have been limited by catheter rotation and data acquisition, displaying, and processing rates on the order of several seconds per frame as well as the use of off-line image processing. Herein, we present a complete IVUS/IVPA imaging system and method capable of real-time IVUS/IVPA imaging, with online data acquisition, image processing, and display of both IVUS and IVPA images. The integrated IVUS/IVPA catheter is fully contained within a 1-mm outer diameter torque cable coupled on the proximal end to a custom-designed spindle enabling optical and electrical coupling to system hardware, including a nanosecond-pulsed laser with a controllable pulse repetition frequency capable of greater than 10 kHz, motor and servo drive, a US pulser/receiver, and a 200-MHz digitizer. The system performance is characterized and demonstrated on a vessel-mimicking phantom with an embedded coronary stent intended to provide IVPA contrast within content of an IVUS image.

Catastrophic Antiphospholipid Syndrome

Catastrophic antiphospholipid syndrome is a rapidly progressive life-threatening disease that causes multiple organ thromboses and dysfunction in the presence of antiphospholipid antibodies. A high index of clinical suspicion and careful investigation are required to make an early diagnosis so that treatment with anticoagulation and corticosteroids can be initiated; plasma exchange and/or intravenous immunoglobulins can be added if the life-threatening condition persists. Despite aggressive treatment and intensive care unit management, patients with catastrophic antiphospholipid syndrome have a 48% mortality rate, primarily attributable to cardiopulmonary failure. This article reviews the current information on the etiopathogenesis, clinical manifestations, diagnosis, management, and prognosis of catastrophic antiphospholipid syndrome.

Promising Health Benefits of the Strawberry: A Focus on Clinical Studies

The potential health benefits associated with dietary intake of fruits have attracted increasing interest. Among berries, the strawberry is a rich source of several nutritive and non-nutritive bioactive compounds, which are implicated in various health-promoting and disease preventive effects. A plethora of studies have examined the benefits of strawberry consumption, such as prevention of inflammation disorders and oxidative stress, reduction of obesity related disorders and heart disease risk, and protection against various types of cancer. This review provides an overview of their nutritional and non-nutritional bioactive compounds and which factors affect their content in strawberries. In addition, the bioavailability and metabolism of major strawberry phytochemicals as well as their actions in combating many pathologies, including cancer, metabolic syndrome, cardiovascular disease, obesity, diabetes, neurodegeneration, along with microbial pathogenesis have been reviewed, with a particular attention to human studies.

Dysfunction in the coagulation system and schizophrenia

Although different hypotheses have been formulated to explain schizophrenia pathogenesis, the links between them are weak. The observation that five psychotic patients on chronic warfarin therapy for deep-vein thrombosis showed long-term remission of psychotic symptoms made us suspect that abnormalities in the coagulation pathway, specifically low tissue plasminogen activator (tPA) activity, could be one of the missing links. Our hypothesis is supported by a high prevalence of conditions affecting tPA activity in drug-naive schizophrenia, such as antiphospholipid antibodies, elevated cytokine levels, hyperinsulinemia and hyperhomocysteinemia. We recently screened a group of schizophrenia patients and controls for conditions affecting tPA activity. Free-protein S deficiency was highly prevalent among patients, but not found in controls. Free-protein S and functional protein C are natural anticoagulants that form complexes that inhibit tPA inhibitors. All participants had normal protein C levels, suggesting that protein S could have a role in schizophrenia, independent of protein C. Chronic patients and those studied during acute episodes had between three and six conditions affecting tPA and/or protein S activity, while patients in remission had up to two, which led us to postulate that multiple conditions affecting tPA and/or protein S activity could contribute to the full expression of schizophrenia phenotype. This paper describes the physiological roles of tPA and protein S, reviewing how their activity influences pathogenesis and comorbidity of schizophrenia. Next, it analyzes how activity of tPA and protein S is influenced by biochemical abnormalities found in schizophrenia. Last, it suggests future directions for research, such as studies on animal models and on therapeutic approaches for schizophrenia aiming at increasing tPA and protein S activity.

Antiatherosclerotic effect of korean red ginseng extract involves regulator of g-protein signaling 5

Regulator of G-protein signaling 5 (RGS5), an inhibitor of Gα(q) and Gα(i) activation, has been reported to have antiatherosclerosis. Previous studies showed antiatherosclerotic effect of Korean red ginseng water extract (KRGE) via multiple signaling pathways. However, potential protective effect of KRGE through RGS5 expression has not been elucidated. Here, we investigated the antiatherosclerotic effect of KRGE in vivo and in vitro and its role on RGS5 mRNA expression. Elevated levels of total cholesterol, lactate dehydrogenase (LDH), and triglyceride (TG) in western diet groups of low-density lipoprotein receptor deficient LDLr(-/-) mice were reversed by oral administration of KRGE. KRGE suppressed transcriptional activity of tumor necrotic factor alpha (TNF-α), interleukin-6 (IL-6), and leptin in adipose tissue. It also potently repressed western diet-induced atheroma formation in aortic sinus. While KRGE showed reduced mRNA expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), IL-1β, IL-6, and TNF-α in LPS-stimulated RAW264.7 cells, it enhanced mRNA expression of RGS5. Moreover, RGS5 siRNA transfection of microglia cells pretreated with KRGE reversed its inhibitory effect on the expression of iNOS, COX-2, and IL-1β mRNA. In conclusion, KRGE showed antiatherosclerotic and anti-inflammatory effects in western diet fed LDLr(-/-) mice and this effect could partly be mediated by RGS5 expression.

Cardioembolic stroke diagnosis using blood biomarkers

Stroke is one of the main causes of death and disability in the world. Cardioembolic etiology accounts for approximately one fifth of all ischemic strokes whereas 25-30% remains undetermined even after an advanced diagnostic workup. Despite there is not any biomarker currently approved to distinguish cardioembolic stroke among other etiologies in clinical practice the use of biomarkers represents a promising valuable complement to determine stroke etiology reducing the number of cryptogenic strokes and aiding in the prescription of the most appropriated primary and secondary treatments in order to minimize therapeutic risks and to avoid recurrences. In this review we present an update about specific cardioembolic stroke-related biomarkers at a protein, transcriptomic and genetic level. Finally, we also focused on reported biomarkers associated with atrial fibrillation (a cardiac illness strongly related with cardioembolic stroke subtype) thus with a potential to become biomarkers to detect cardioembolic stroke in the future.

Protectin DX, a double lipoxygenase product of DHA, inhibits both ROS production in human neutrophils and cyclooxygenase activities

Neutrophils play a major role in inflammation by releasing large amounts of reactive oxygen species (ROS) produced by NADPH oxidase (NOX) and myeloperoxidase (MPO). This ROS overproduction is mediated by phosphorylation of the NOX subunits in an uncontrolled manner. Therefore, targeting neutrophil subunits would represent a promising strategy to moderate NOX activity, lower ROS, and other inflammatory agents, such as cytokines and leukotrienes, produced by neutrophils. For this purpose, we investigated the effects of protectin DX (PDX)-a docosahexaenoic acid di-hydroxylated product which inhibits blood platelet aggregation-on neutrophil activation in vitro. We found that PDX decreases ROS production, inhibits NOX activation and MPO release from neutrophils. We also confirm, that PDX is an anti-aggregatory and anti-inflammatory agent by inhibiting both cyclooxygenase-1 and -2 (COX-1 and COX-2, E.C. 1.14.99.1) as well as COX-2 in lipopolysaccharides-treated human neutrophils. However, PDX has no effect on the 5-lipoxygenase pathway that produces the chemotactic agent leukotriene B4 (LTB4). Taken together, our results suggest that PDX could be a protective agent against neutrophil invasion in chronic inflammatory diseases.

Paired measurements of paraoxonase 1 and serum amyloid A as useful disease markers

Paraoxonase 1 (PON1) and serum amyloid A (SAA) are proteins carried by high-density lipoprotein (HDL) particles. Among the HDL-associated protein molecules, SAA, an inflammation-related marker, and PON1, an antioxidant marker, tend to change in relatively clear opposite directions in physiological situations. In clinical chemistry, paired measurements of both markers may provide useful information to understand dysfunctional HDL in diseases with inflammation and oxidative stress conditions. Actually, limited clinical studies have suggested that the combined use of PON1 and SAA may be a tool for observing the pathophysiology of some disease entities. From the findings of experimental studies, PON1 appears to be cooperatively regulated by inflammation- and oxidative stress-related molecules linked with SAA regulation in humans. More studies remain to be performed to ascertain the value of paired measurements of both promising markers in clinical practice.

Oxytocin administration attenuates atherosclerosis and inflammation in Watanabe Heritable Hyperlipidemic rabbits

Oxytocin (OT) is a neurohypophyseal peptide traditionally associated with female reproductive functioning, and more recently with prosocial behavior. OT and its receptor are also expressed in the heart and vascular tissue and play a role in cardiovascular homeostasis. In vitro, it has been demonstrated that OT decreases NADPH-dependent superoxide production and pro-inflammatory cytokine release from vascular endothelial cells and macrophages, suggesting that OT may attenuate pathophysiological processes involved with atherosclerotic lesion formation. The present study sought to determine the effect of chronic exogenous OT administration on inflammation and atherosclerosis in an animal model of dyslipidemia and atherosclerosis, the Watanabe Heritable Hyperlipidemic (WHHL) rabbit. Twenty-two, 3-month-old WHHLs were surgically implanted with osmotic mini-pumps containing OT (n=11) or vehicle (n=11), and then were individually housed for the entire study. Blood and 24-h urine samples were taken at baseline and after 8 (midpoint) and 16 (endpoint) weeks of treatment. At endpoint, the aortas and visceral fat samples were dissected and stored for analyses. There were no group differences in body weight, serum lipids, plasma/urinary measures of oxidative stress, plasma cortisol or urinary catecholamines over the 16-week treatment. OT-treated animals exhibited significantly lower plasma C-reactive protein levels at midpoint and endpoint and developed significantly less atherosclerosis in the thoracic aorta relative to vehicle control animals at endpoint (p<0.05). Cytokine gene expression from visceral adipose tissue samples suggested that there was a decrease in adipose tissue inflammation in the OT-treated group compared to the vehicle control group, however these differences were not statistically significant. These results suggest that chronic peripheral OT administration can inhibit inflammation and atherosclerotic lesion development.

Perivascular adipose tissue-secreted angiopoietin-like protein 2 (Angptl2) accelerates neointimal hyperplasia after endovascular injury

Much attention is currently focused on the role of perivascular adipose tissue in development of cardiovascular disease (CVD). Some researchers view it as promoting CVD through secretion of cytokines and growth factors called adipokines, while recent reports reveal that perivascular adipose tissue can exert a protective effect on CVD development. Furthermore, adiponectin, an anti-inflammatory adipokine, reportedly suppresses neointimal hyperplasia after endovascular injury, whereas such vascular remodeling is enhanced by pro-inflammatory adipokines secreted by perivascular adipose, such as tumor necrosis factor-α (TNF-α). These findings suggest that extent of vascular remodeling, a pathological process associated with CVD development, depends on the balance between pro- and anti-inflammatory adipokines secreted from perivascular adipose tissue. We previously demonstrated that angiopoietin-like protein 2 (Angptl2), a pro-inflammatory factor secreted by adipose tissue, promotes adipose tissue inflammation and subsequent systemic insulin resistance in obesity. Here, we examined whether Angptl2 secreted by perivascular adipose tissue contributes to vascular remodeling after endovascular injury in studies of transgenic mice expressing Angptl2 in adipose tissue (aP2-Angptl2 transgenic mice) and Angptl2 knockout mice (Angptl2(-/-) mice). To assess the role of Angptl2 secreted by perivascular adipose tissue on vascular remodeling after endovascular injury, we performed adipose tissue transplantation experiments using these mice. Wild-type mice with perivascular adipose tissue derived from aP2-Angptl2 mice exhibited accelerated neointimal hyperplasia after endovascular injury compared to wild-type mice transplanted with wild-type tissue. Conversely, vascular inflammation and neointimal hyperplasia after endovascular injury were significantly attenuated in wild-type mice transplanted with Angptl2(-/-) mouse-derived perivascular adipose tissue compared to wild-type mice transplanted with wild-type tissue. RT-PCR analysis revealed that mouse Angptl2 expression in perivascular adipose tissue was significantly increased by aging, hypercholesterolemia, and endovascular injury, all risk factors for coronary heart disease (CHD). Immunohistochemical and RT-PCR analysis of tissues from patients with CHD and from non-CHD patients indicated that ANGPTL2 expression in epicardial adipose tissue was unchanged. Interestingly, that analysis also revealed a positive correlation in ANGPTL2 and ADIPONECTIN expression in epicardial adipose tissue of non-CHD patients, a correlation not seen in CHD patients. However, in epicardial adipose tissue from CHD patients, ANGPTL2 expression was positively correlated with that of TNF-α, a correlation was not seen in non-CHD patients. These findings suggest that pro-inflammatory adipokines cooperatively accelerate CHD development and that maintaining a balance between pro- and anti-inflammatory adipokines likely protects non-CHD patients from developing CHD. Overall, our studies demonstrate that perivascular adipose tissue-secreted Angptl2 accelerates vascular inflammation and the subsequent CVD development.

Estradiol inhibits vascular endothelial cells pro-inflammatory activation induced by C-reactive protein

In addition of being an important inflammatory biomarker and a risk factor for cardiovascular disease, much evidence indicates that the C-reactive protein (CRP) contributes to the atherosclerosis development process. This plasmatic protein synthesized by hepatocytes in response to inflammation and tissue injury induces pro-inflammatory molecules' expression by endothelial cells (ECs). Previous studies showed that the 17β-estradiol (E2) has beneficial effects on vascular cells by reducing in vitro pro-inflammatory molecules expressions in EC. Therefore, we hypothesize that E2 blocks or reduces CRP-mediated inflammatory responses by modulating endogenous production of CRP in EC and/or activation mechanisms. Using human aortic ECs (HAECs), we first evaluated CRP production by vascular EC and second demonstrated its self-induction. Indeed, recombinant human CRP stimulation induces a fivefold increase of CRP expression. A 1-h pre-treatment of E2 at a physiologic dose (10⁻⁹ M) leads to an important decrease of CRP production suggesting a partial blockage of its amplification loop mechanism. Furthermore, in HAEC, E2 reduces the secretion of the most potent agonist of CRP induction, the IL-6, by 21 %. E2 pre-treatment also decreased the expression of pro-inflammatory molecules IL-8, VCAM-1, and ICAM-1 induced by CRP and involved in leukocytes recruitment. In addition, we demonstrated that E2 could restore vascular endothelial growth factor-mediated EC migration response impaired by CRP suggesting another pro-angiogenic property of this hormone. These findings suggest that E2 can interfere with CRP pro-inflammatory effects via activation signals using its rapid, non-genomic pathway that may provide a new mechanism to improve vascular repair.

Hepatic and cardiac steatosis: are they coupled?

Cardiac and hepatic fat are associated with insulin resistance and impaired suppression of lipolysis, ultimately leading to lipotoxicity. In the heart the lipotoxic effect translates into an impairment of energetic and mechanical efficiency, whereas in the liver a fibrogenic response is favored by the abundance of inflammatory cells. These features precede, and likely contribute to, left ventricular overload and cardiac hypertrophy through mechanisms similar to the ones observed in the progression of liver damage in nonalcoholic fatty liver disease (NAFLD). Collectively these findings suggest the presence of complex and intertwined interrelationships between NAFLD, myocardial steatosis, and coronary artery disease.

Inflammatory mediators involved in the progression of the metabolic syndrome

The metabolic syndrome is often associated with type 2 diabetes mellitus, dyslipidemia, atherosclerosis, hypertension, steatosis of the liver and other organs, as well as hypertension, type 2 diabetes mellitus, and atherosclerosis. Recent studies have implicated a number of inflammatory mediators including cytokines, adipokines and eicosanoids in the inflammatory responses that accompany the metabolic syndrome. Measurements of the circulating levels of the inflammatory molecules that accompany this syndrome might provide leads to therapeutic approaches to modulate the inflammatory responses and thereby alter disease progression. In this review, we summarize recent studies on classical and newer inflammatory mediators in the pathogenesis of the metabolic syndrome in humans and experimental models.

The role of platelets in the pathogenesis of systemic sclerosis

Systemic sclerosis (SSc) is an inflammatory disease of unknown etiology characterized by widespread organ dysfunction due to fibrosis and ischemia. Its nebulous pathogenic background and the consequent absence of an etiological therapy prevent the adoption of satisfying treatment strategies, able to improve patients’ quality of life and survival and stimulate researchers to identify a unifying pathogenic target. Platelets show a unique biological behavior, lying at the crossroads between vascular function, innate and adaptive immunity, and regulation of cell proliferation. Consequently they are also emerging players in the pathogenesis of many inflammatory diseases, including SSc. In the setting of SSc platelets are detectable in a persistent activated state, which is intimately linked to the concomitant presence of an injured endothelium and to the widespread activation of the innate and adaptive immune system. As a consistent circulating source of bioactive compounds platelets contribute to the development of many characteristic phenomena of SSc, such as fibrosis and impaired vascular tone.

Blood biomarkers in cardioembolic stroke

One promising field in neurovascular diseases investigation is the use of biomarkers to guide stroke etiology diagnosis and classification. Since treatment differs among etiologic subtypes and nowadays many patients receive a diagnosis of undetermined stroke, biomarkers might become an important additional diagnostic tool. In this review we update current knowledge about biomarkers related with cardioembolic stroke etiology (such as BNP and D-dimer proteins, or PITX2 and ZFHX3 genes), that in the future, might allow rapidly guiding other diagnostic tests and accelerating the onset of an optimal secondary prevention.

Deletion of L-selectin increases atherosclerosis development in ApoE-/- mice

Atherosclerosis is an inflammatory disease characterized by accumulation of leukocytes in the arterial intima. Members of the selectin family of adhesion molecules are important mediators of leukocyte extravasation. However, it is unclear whether L-selectin (L-sel) is involved in the pathogenesis of atherosclerosis. In the present study, mice deficient in L-selectin (L-sel(-/-)) animals were crossed with mice lacking Apolipoprotein E (ApoE(-/-)). The development of atherosclerosis was analyzed in double-knockout ApoE/L-sel (ApoE(-/-)L-sel(-/-)) mice and the corresponding ApoE(-/-) controls fed either a normal or a high cholesterol diet (HCD). After 6 weeks of HCD, aortic lesions were increased two-fold in ApoE(-/-)L-sel(-/-) mice as compared to ApoE(-/-) controls (2.46%±0.54% vs 1.28%±0.24% of total aortic area; p<0.05). Formation of atherosclerotic lesions was also enhanced in 6-month-old ApoE(-/-)L-sel(-/-) animals fed a normal diet (10.45%±2.58% vs 1.87%±0.37%; p<0.05). In contrast, after 12 weeks of HCD, there was no difference in atheroma formation between ApoE(-/-)L-sel(-/-) and ApoE(-/-) mice. Serum cholesterol levels remained unchanged by L-sel deletion. Atherosclerotic plaques did not exhibit any differences in cellular composition assessed by immunohistochemistry for CD68, CD3, CD4, and CD8 in ApoE(-/-)L-sel(-/-) as compared to ApoE(-/-) mice. Leukocyte rolling on lesions in the aorta was similar in ApoE(-/-)L-sel(-/-) and ApoE(-/-) animals. ApoE(-/-)L-sel(-/-) mice exhibited reduced size and cellularity of peripheral lymph nodes, increased size of spleen, and increased number of peripheral lymphocytes as compared to ApoE(-/-) controls. These data indicate that L-sel does not promote atherosclerotic lesion formation and suggest that it rather protects from early atherosclerosis.

Carotid restenosis is associated with plasma ADMA concentrations in carotid endarterectomy patients

BACKGROUND

The aim of this work has been to study the association between plasma asymmetric dimethylarginine (ADMA) concentrations and carotid stenosis in a group of 64 patients undergoing carotid endarterectomy (CEA).

METHODS

Arginine, ADMA and symmetric dimethylarginine (SDMA) were measured using capillary electrophoresis with UV detection. An evaluation of plasma concentrations of total cysteine (tCys) and total homocysteine (tHcy) was also performed.

RESULTS

Pearson's analysis show a positive correlation between ADMA and carotid stenosis (r=0.37, p=0.003), which is also confirmed after stepwise multiple linear regression analysis. ADMA plasma concentrations were significantly associated with tHcy (r=0.40, p=0.001) and to a lesser extent, even if not significantly, with tCys (r=0.23, p=0.07).

CONCLUSIONS

Our data suggest that plasma ADMA is involved in carotid narrowing after CEA intervention. This suggests that this molecule may have an important role in the events that lead to stenosis.

Mechanism of ceroid formation in atherosclerotic plaque: in situ studies using a combination of Raman and fluorescence spectroscopy

Accumulation of the lipid-protein complex ceroid is a characteristic of atherosclerotic plaque. The mechanism of ceroid formation has been extensively studied, because the complex is postulated to contribute to plaque irreversibility. Despite intensive research, ceroid deposits are defined through their fluorescence and histochemical staining properties, while their composition remains unknown. Using Raman and fluorescence spectral microscopy, we examine the composition of ceroid in situ in aorta and coronary artery plaque. The synergy of these two types of spectroscopy allows for identification of ceroid via its fluorescence signature and elucidation of its chemical composition through the acquisition of a Raman spectrum. In accordance with in vitro predictions, low density lipoprotein (LDL) appears within the deposits primarily in its peroxidized form. The main forms of modified LDL detected in both coronary artery and aortic plaques are peroxidation products from the Fenton reaction and myeloperoxidase-hypochlorite pathway. These two peroxidation products occur in similar concentrations within the deposits and represent ∼40 and 30% of the total LDL (native and peroxidized) in the aorta and coronary artery deposits, respectively. To our knowledge, this study is the first to successfully employ Raman spectroscopy to unravel a metabolic pathway involved in disease pathogenesis: the formation of ceroid in atherosclerotic plaque.

Towards a unifying, systems biology understanding of large-scale cellular death and destruction caused by poorly liganded iron: Parkinson's, Huntington's, Alzheimer's, prions, bactericides, chemical toxicology and others as examples

Exposure to a variety of toxins and/or infectious agents leads to disease, degeneration and death, often characterised by circumstances in which cells or tissues do not merely die and cease to function but may be more or less entirely obliterated. It is then legitimate to ask the question as to whether, despite the many kinds of agent involved, there may be at least some unifying mechanisms of such cell death and destruction. I summarise the evidence that in a great many cases, one underlying mechanism, providing major stresses of this type, entails continuing and autocatalytic production (based on positive feedback mechanisms) of hydroxyl radicals via Fenton chemistry involving poorly liganded iron, leading to cell death via apoptosis (probably including via pathways induced by changes in the NF-κB system). While every pathway is in some sense connected to every other one, I highlight the literature evidence suggesting that the degenerative effects of many diseases and toxicological insults converge on iron dysregulation. This highlights specifically the role of iron metabolism, and the detailed speciation of iron, in chemical and other toxicology, and has significant implications for the use of iron chelating substances (probably in partnership with appropriate anti-oxidants) as nutritional or therapeutic agents in inhibiting both the progression of these mainly degenerative diseases and the sequelae of both chronic and acute toxin exposure. The complexity of biochemical networks, especially those involving autocatalytic behaviour and positive feedbacks, means that multiple interventions (e.g. of iron chelators plus antioxidants) are likely to prove most effective. A variety of systems biology approaches, that I summarise, can predict both the mechanisms involved in these cell death pathways and the optimal sites of action for nutritional or pharmacological interventions.

Stress and inflammation: a biobehavioral approach for nursing research

Despite known advantages, the use of biobehavioral approaches in nursing research remains limited. The purposes of this article are to (1) present applications of stress and inflammation in various health conditions as examples of biobehavioral concepts and (2) stimulate similar applications of biobehavioral concepts in future nursing research. Under a biobehavioral conceptual framework, studies on stress and selective inflammatory biomarkers in cardiovascular, cancer, and pulmonary health are reviewed and summarized. Inflammation underlies many diseases, and stress is a significant source of increased inflammation. Biobehavioral concepts of stress and inflammation are highly relevant to nursing research concerned with health-related issues. Diverse biobehavioral concepts are readily applicable and should be utilized in nursing research with children and adults. To stimulate further biobehavioral research, more training and resources for nurse scientists, more unified conceptual definitions and biobehavioral conceptual frameworks, rigorous and expanded methodologies, and more collaboration are essential.

Mechanical signals activate vascular endothelial growth factor receptor-2 to upregulate endothelial cell proliferation during inflammation

Signals generated by the dynamic mechanical strain critically regulate endothelial cell proliferation and angiogenesis; however, the molecular basis remains unclear. We investigated the mechanisms by which human dermal microvascular endothelial cells (HDMECs) perceive mechanical signals and relay them intracellularly to regulate gene expression and endothelial cell proliferation. HDMECs were exposed to low/physiologic levels of dynamic strain and probed for the differential activation/inhibition of kinases in the mechanosignaling cascade associated with endothelial cell gene activation. Because angiogenesis is important at inflammatory sites, we also assessed the mechanisms of mechanosignaling in the presence of an proinflammatory cytokine IL-1beta. In this article, we demonstrate that the mechanosignaling cascade is initiated by vascular endothelial growth receptor-2 (VEGFR2) activation. Mechanoactivation of VEGFR2 results in its nuclear translocation and elevation of PI3K-dependent Ser473-Akt phosphorylation. Subsequently, activated Akt inactivates the kinase activity of the serine/threonine kinase, glycogen synthase kinase-3beta (GSK3beta), via its Ser9 phosphorylation. Thus, inactive GSK3beta fails to phosphorylate cyclin D1 and prevents its proteosomal degradation and, consequently, promotes endothelial cell survival and proliferation. In the presence of IL-1beta, cyclin D1 is phosphorylated and degraded, leading to inhibition of cell proliferation. However, mechanical signals repress cyclin D1 phosphorylation and upregulate cell proliferation, despite the presence of IL-1beta. The data indicate that the VEGFR2/Akt/GSK3beta signaling cascade plays a critical role in sensing and phospho-relaying mechanical stimuli in endothelial cells. Furthermore, mechanical forces control highly interconnected networks of proinflammatory and Akt signaling cascades to upregulate endothelial cell proliferation.

[State of the art: high resolution MR imaging of carotid atherosclerotic plaque]

A third of cerebrovascular accidents are a complication from carotid artery plaque. In addition to the degree of stenosis, plaque composition and morphology are key elements in determining the probability of complication from the atherosclerotic plaque. High resolution MRI can characterize plaque composition and morphology and therefore help identify unstable plaque. The purpose of this review is to summarize recent concepts on unstable plaque and underlying inflammation. The signal characteristics of the different components of plaque on high resolution MRI then be reviewed. Finally, current morphological and functional criteria for unstable plaque will be discussed.

Hepatic gene expression in flounder chronically exposed to multiply polluted estuarine sediment: Absence of classical exposure 'biomarker' signals and induction of inflammatory, innate immune and apoptotic pathways

The effects of chronic long-term exposure to multiply polluted environments on fish are not well understood, but environmental surveys suggest that such exposure may cause a variety of pathologies, including cancers. Transcriptomic profiling has recently been used to assess gene expression in European flounder (Platichthys flesus) living in several polluted and clean estuaries. However, the gene expression changes detected were not unequivocally elicited by pollution, most likely due to the confounding effects of natural estuarine ecosystem variables. In this study flounder from an uncontaminated estuary were held on clean or polluted sediments in mesocosms, allowing control of variables such as salinity, temperature, and diet. After 7 months flounder were removed from each mesocosm and hepatocytes prepared from fish exposed to clean or polluted sediments. The hepatocytes were treated with benzo(a)pyrene (BAP), estradiol (E2), copper, a mixture of these three, or with the vehicle DMSO. A flounder cDNA microarray was then used to measure hepatocyte transcript abundance after each treatment. The results show that long-term chronic exposure to a multiply polluted sediment causes increases in the expression of mRNAs coding for proteins of the endogenous apoptotic programme, of innate immunity and inflammation. Contrary to expectation, the expression of mRNAs which are commonly used as biomarkers of environmental exposure to particular contaminants were not changed, or were changed contrary to expectation. However, acute treatment of hepatocytes from flounder from both clean and polluted sediments with BAP or E2 caused the expected changes in the expression of these biomarkers. Thus transcriptomic analysis of flounder exposed long-term to chronic pollution causes a different pattern of gene expression than in fish acutely treated with single chemicals, and reveals novel potential biomarkers of environmental contaminant exposure. These novel biomarkers include Diablo, a gene involved in apoptotic pathways and highly differentially regulated by both chronic and acute exposure to multiple pollutants.

Abnormal aortic elasticity in patients with liver steatosis

AIM

Non-alcoholic fatty liver disease (NAFLD) may be associated with insulin resistance. We aimed to evaluate elastic properties of aorta in patients with NAFLD.

MATERIAL AND METHOD

Ninety-two patients with NAFLD and 47 healthy subjects were performed ultrasonographic and echocardiographic examination. Aortic stiffness index (ASI), aortic distensibility (AD) and aortic strain (AS) were compared between healthy subjects and patients and also among grade I and II liver steatosis. Statistical analysis was performed by Independent-Samples t-test, Pearson's correlation test using SPSS 11.0.

RESULTS

ASI was significantly increased whereas AS and AD were reduced (p>0.05) in patients compared to normal ones. ASI was significantly increased while AD and AS slightly increased in patients with grade II liver steatosis compare to grade I. SBP and DBP, cholesterol levels, fasting blood glucose (FBG) were also increased and doppler flow parameters of mitral inflow were abnormally changed in those patients. ASI was positively correlated with FBG, ALT and ALP levels, LDL cholesterol, heart rate and deceleration time of mitral E wave.

CONCLUSION

Elastic properties of aorta were abnormally changed in patients with NAFLD. Multiple hemodynamic abnormalities probably associated with insulin resistance may be accountable for abnormal elastic properties of aorta.

Iron behaving badly: inappropriate iron chelation as a major contributor to the aetiology of vascular and other progressive inflammatory and degenerative diseases

BACKGROUND

The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular 'reactive oxygen species' (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation.

REVIEW

We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation).The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible.This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, since in some circumstances (especially the presence of poorly liganded iron) molecules that are nominally antioxidants can actually act as pro-oxidants. The reduction of redox stress thus requires suitable levels of both antioxidants and effective iron chelators. Some polyphenolic antioxidants may serve both roles.Understanding the exact speciation and liganding of iron in all its states is thus crucial to separating its various pro- and anti-inflammatory activities. Redox stress, innate immunity and pro- (and some anti-)inflammatory cytokines are linked in particular via signalling pathways involving NF-kappaB and p38, with the oxidative roles of iron here seemingly involved upstream of the IkappaB kinase (IKK) reaction. In a number of cases it is possible to identify mechanisms by which ROSs and poorly liganded iron act synergistically and autocatalytically, leading to 'runaway' reactions that are hard to control unless one tackles multiple sites of action simultaneously. Some molecules such as statins and erythropoietin, not traditionally associated with anti-inflammatory activity, do indeed have 'pleiotropic' anti-inflammatory effects that may be of benefit here.

CONCLUSION

Overall we argue, by synthesising a widely dispersed literature, that the role of poorly liganded iron has been rather underappreciated in the past, and that in combination with peroxide and superoxide its activity underpins the behaviour of a great many physiological processes that degrade over time. Understanding these requires an integrative, systems-level approach that may lead to novel therapeutic targets.

Delivery strategies to target therapies to inflammatory tissue

BACKGROUND

Inflammation plays a key role in many chronic disease processes as well as an acute role in injury and wound healing. Various cell types are recruited from the bloodstream to the inflamed site through adhesion molecules, cytokines, chemokines and others.

OBJECTIVES

This review examines many drug-targeting strategies that make use of these molecules or signaling pathways, and seeks to describe certain commonalities irrespective of the disease process or agent to be delivered.

METHODS

A survey of the literature, primarily within the last year, was performed. Search words included 'drug targeting' and 'inflammation' and of those, the scope was refined to include those studies that specifically sought to modify or ameliorate an aspect of the inflammatory process in the treatment of a disease.

RESULTS/CONCLUSION

Inflammation plays a key role in many diseases, and many similar targets (such as adhesion molecules) are the focus of the treatment of those diseases.

Automatic mining of the literature to generate new hypotheses for the possible link between periodontitis and atherosclerosis: lipopolysaccharide as a case study

AIM

The aim of the current report was to generate and explore new hypotheses into how, in a pathophysiological sense, atherosclerosis and periodontitis could be linked.

MATERIAL AND METHODS

Two different biomedical informatics techniques were used: an association-based technique that generated a ranked list of genes associated with the diseases, and a natural language processing tool that extracted the relationships between the retrieved genes and lipopolysaccharide (LPS).

RESULTS

This combined approach of association-based and natural language processing-based literature mining identified a hit list of 16 candidate genes, with PON1 as the primary candidate.

CONCLUSIONS

Further study of the literature prompted the hypothesis that PON1 might connect periodontitis with atherosclerosis in both an LPS-dependent and a non-LPS-dependent manner. Furthermore, the resulting genes not only confirmed already known associations between the two diseases, but also provided genes or gene products that have only been investigated separately in the two disease states, and genes or gene products previously reported to be involved in atherosclerosis. These findings remain to be investigated through clinical studies. This example of multidisciplinary research illustrates how collaborative efforts of investigators from different fields of expertise can result in the discovery of new hypotheses.

Intraplaque hemorrhage assessed by high-resolution magnetic resonance imaging and C-reactive protein in carotid atherosclerosis

BACKGROUND

Carotid intraplaque hemorrhage is a marker of atheroma instability. Noninvasive assessment of bleeding can be performed by high-resolution magnetic resonance imaging (MRI), but its association with inflammatory markers has not been clearly demonstrated.

METHODS

We evaluated consecutive carotid endarterectomy patients that underwent high-resolution MRI, independent evaluation of neurologic symptoms, C-reactive protein measurement, and histologic analysis. Intraplaque hemorrhage was determined by the presence of a hyperintense MRI signal (T1-weighted sequence).

RESULTS

The study included 70 predominantly male (66%) and hypertensive (89%) patients (89%) aged 66 +/- 9 years old. MR angiography identified 15 patients (21.5%) with stenosis between 50% and 69%, 15 (21.5%) with stenosis between 70% and 90%, and 40 (57%) with stenosis >90%. High-resolution MRI depicted a hyperintense signal suggestive of intraplaque bleeding in 45 subjects (64%). All patients who had had transient ischemic attacks >90 days before the surgery showed a hyperintense signal on MRI (P = .007). Age, gender, traditional cardiovascular risk factors, and history of myocardial infarction or peripheral arterial disease were similar in patients with or without signs of intraplaque bleeding on MRI. There was excellent agreement between acute or recent hemorrhage on histologic and MRI findings (kappa coefficient, 0.91; 95% confidence interval, 0.81 to 1.00). Only one of 45 patients (2%) with a hyperintense signal on MRI did not have acute or recent hemorrhage in the histologic analysis (P < .001). High-sensitivity C-reactive protein levels were similar for different degrees of carotid stenosis as assessed by MR angiography, but they were significantly higher in clinically unstable patients (P = .006) and in those with a positive hyperintense MRI signal (P = .01). In an aggregated analysis of neurologic symptoms and MRI findings, we found a progressive increase of high-sensitivity C-reactive protein levels (P = .02).

CONCLUSIONS

Intraplaque hemorrhage evaluated by MRI identified neurologically unstable patients with increased levels of high-sensitivity C-reactive protein regardless of the degree of carotid stenosis.

Biomarkers of atherosclerosis and the potential of MRI for the diagnosis of vulnerable plaque

Atherosclerosis is a chronic inflammatory vascular disease. As it is an inflammation process, many cellular and molecular events are involved at each step of the progression of atherosclerosis from an early fatty streak lesion to a highly dangerous rupture-prone plaque. Magnetic resonance imaging (MRI) is a well-established diagnostic tool for many kinds of chronic inflammation in various systems and organs, and recent improvements in spatial resolution and contrast strategies make it a promising technique for the characterization of inflammatory vessel walls. The first part of this review will briefly introduce the main cellular and molecular processes involved in atherosclerotic lesions; the second part will focus on the use of high-resolution MRI and present-generation contrast agents for plaque characterization; and the third part will present some recent and ongoing cellular and molecular MRI studies of atherosclerosis.

Essential fatty acids: biochemistry, physiology and pathology

Essential fatty acids (EFAs), linoleic acid (LA), and alpha-linolenic acid (ALA) are essential for humans, and are freely available in the diet. Hence, EFA deficiency is extremely rare in humans. To derive the full benefits of EFAs, they need to be metabolized to their respective long-chain metabolites, i.e., dihomo-gamma-linolenic acid (DGLA), and arachidonic acid (AA) from LA; and eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) from ALA. Some of these long-chain metabolites not only form precursors to respective prostaglandins (PGs), thromboxanes (TXs), and leukotrienes (LTs), but also give rise to lipoxins (LXs) and resolvins that have potent anti-inflammatory actions. Furthermore, EFAs and their metabolites may function as endogenous angiotensin-converting enzyme and 3-hdroxy-3-methylglutaryl coenzyme A reductase inhibitors, nitric oxide (NO) enhancers, anti-hypertensives, and anti-atherosclerotic molecules. Recent studies revealed that EFAs react with NO to yield respective nitroalkene derivatives that exert cell-signaling actions via ligation and activation of peroxisome proliferator-activated receptors. The metabolism of EFAs is altered in several diseases such as obesity, hypertension, diabetes mellitus, coronary heart disease, schizophrenia, Alzheimer's disease, atherosclerosis, and cancer. Thus, EFAs and their derivatives have varied biological actions and seem to be involved in several physiological and pathological processes.

Liver steatosis coexists with myocardial insulin resistance and coronary dysfunction in patients with type 2 diabetes

Nonalcoholic fatty liver (NAFL) is a common comorbidity in patients with type 2 diabetes and links to the risk of coronary syndromes. The aim was to determine the manifestations of metabolic syndrome in different organs in patients with liver steatosis. We studied 55 type 2 diabetic patients with coronary artery disease using positron emission tomography. Myocardial perfusion was measured with [15O]H2O and myocardial and skeletal muscle glucose uptake with 2-deoxy-2-[18F]fluoro-D-glucose during hyperinsulinemic euglycemia. Liver fat content was determined by magnetic resonance proton spectroscopy. Patients were divided on the basis of their median (8%) into two groups with low (4.6 +/- 2.0%) and high (17.4 +/- 8.0%) liver fat content. The groups were well matched for age, BMI, and fasting plasma glucose. In addition to insulin resistance at the whole body level (P = 0.012) and muscle (P = 0.002), the high liver fat group had lower insulin-stimulated myocardial glucose uptake (P = 0.040) and glucose extraction rate (P = 0.0006) compared with the low liver fat group. In multiple regression analysis, liver fat content was the most significant explanatory variable for myocardial insulin resistance. In addition, the high liver fat group had increased concentrations of high sensitivity C-reactive protein, soluble forms of E-selectin, vascular adhesion protein-1, and intercellular adhesion molecule-1 (P < 0.05) and lower coronary flow reserve (P = 0.02) compared with the low liver fat group. In conclusion, in patients with type 2 diabetes and coronary artery disease, liver fat content is a novel independent indicator of myocardial insulin resistance and reduced coronary functional capacity. Further studies will reveal the effect of hepatic fat reduction on myocardial metabolism and coronary function.

Vascular dendritic cells in giant cell arteritis

Giant cell arteritis (GCA) is a granulomatous vasculitis that selectively targets medium-sized and large arteries, especially the cranial branches of the aorta. The inflammatory activity of vascular lesions is driven by adaptive immune responses, with CD4 T cells undergoing clonal expansion in the vessel wall and releasing interferon gamma. Recent studies have described a distinctive population of dendritic cells (DCs) localized at the adventitia-media border of normal medium-sized arteries that appear to play a critical role in the initiation of vasculitis. Immune effector functions of this DC population are being examined in human artery-severe combined immunodeficient (SCID) mouse chimeras. In their constitutive form, CD11c+ fascin+ adventitial DCs are not recognized by alloreactive T cells. Triggering with Toll-like receptor (TLR) ligands is sufficient to break this state of tolerance and initiate DC activation, T-cell recruitment, T-cell activation, and T-cell retention in the arterial wall. Systemic administration of ligands for TLR2 or -4 in human artery-SCID chimeras drives differentiation of adventitial DCs into chemokine-producing effector cells with high-level expression of both CD83 and CD86 and mediates T-cell regulatory function through release of interleukin 18. In established vasculitis, fully matured DCs retain antigen-presenting function; antibody-mediated DC depletion disrupts T-cell and macrophage activation and has marked anti-inflammatory effects. We conclude that adventitial DCs, an indigenous cell population of the arterial wall, are responsive to pathogen-derived macromolecules and have gatekeeper function in regulating T-cell recruitment and retention to the arterial adventitia. A switch of adventitial DCs from being nonstimulatory to T-cell activating emerges as a critical event in the initiation of vasculitis.

Cholesterol and 24S-hydroxycholesterol trafficking in Alzheimer's disease

Cholesterol and the cholesterol oxide 24S-hydroxycholesterol (24S-HC) are highly enriched in the human CNS. Clinical, genetic, neurochemical and epidemiological evidence continue to support dysfunctional cholesterol metabolism as an important contributing factor driving the development and/or progression of Alzheimer's disease (AD) neuropathology. Cholesterol overabundance in the brain plasma membrane lipid- raft domains, appears to be fundamental to the generation of the more neurotoxic forms of amyloid-beta (Abeta) peptide from beta-amyloid holoprotein precursor. 24S-HC may have a pivotal role in promoting altered inflammatory signaling, apoptotic genetic responses and AD-type change. In clinical studies, cholesterol-lowering statins, nonsteroidal anti-inflammatory drugs, cholesterol absorption/transport inhibitors and related modulators of cholesterol trafficking have demonstrated some pharmacological benefit for the treatment of AD, but overall their efficacy at slowing the cognitive decline and the progression of AD remains controversial and open to question.

Essential role of PKC-zeta in normal and angiotensin II-accelerated neointimal growth after vascular injury

The contribution of atypical protein kinase C (PKC)-zeta to ANG II-accelerated restenosis after endoluminal vascular injury was investigated by using the rat carotid balloon injury model. Exposure of injured arteries to ANG II resulted in an extensive neointimal thickening (1.9 times) compared with vehicle at day 14. Treatment with PKC-zeta antisense, but not scrambled, oligonucleotides reduced neointimal formation observed in the presence or absence of ANG II. Examination of early events (2 days) after injury showed an increase in cellularity in the perivascular area of the artery wall that was transferred to the adventitia and media after exposure to ANG II, events blocked by PKC-zeta antisense, but not scrambled, oligonucleotides. A positive correlation between medial cellularity at day 2 and extent of neointimal growth at day 14 was established. Immunohistochemical analysis showed that upregulation of inflammatory markers after injury, as well as infiltration of ED1(+) monocytes/macrophages from the perivascular area to the adventitia, was accelerated by ANG II. However, ANG II-stimulated medial increase in cellularity was proliferation independent, and these cells were monocyte chemoattractant protein-1(+)/vimentin(+) but ED1(-)/VCAM(-). PKC-zeta is degraded after injury, and inhibition of its neosynthesis in medial vascular smooth muscle cells or in infiltrating cells with PKC-zeta antisense attenuated medial cellularity and expression of inflammation mediators without reversing smooth muscle cell dedifferentiation. Together, these data indicate that PKC-zeta plays a critical role in normal and ANG II-accelerated neointimal growth through a mechanism involving upregulation of inflammatory mediators, leading to cell infiltration in the media of the vascular wall.

The expression of CD40-CD40L and activities of matrix metalloproteinases in atherosclerotic rats

This study investigated the expression of CD40, CD40 ligand (CD40L) and matrix metalloproteinases (MMPs) in dietary-induced atherosclerosis in rats. Wister rats were fed with high cholesterol diet (As group, n = 6) or with normal diet (N group, n = 6). Blood cells that express CD40 and CD40L were sorted by flow cytometry, the MMP-2 and MMP-9 were measured by zymography method. The morphological locations of MMP-2 and MMP-9 in the aorta were studied with immunohistochemistry and by microscopy. The results showed that the expression of CD40, CD40L and matrix metalloproteinase were higher in As group than those in control group. The MMP-2 and MMP-9 were positive in As group but negative in control group by immunohistochemistry study. Our results suggest that the expression of CD40 and CD40L in the blood cells and the activities of MMP-2 and MMP-9 in plasma were higher in As group than those in Normal group, indicating that they may contribute to the formation of atherosclerosis.

The emerging role of flavonoid-rich cocoa and chocolate in cardiovascular health and disease

Cocoa and chocolate have recently been found to be rich plant-derived sources of antioxidant flavonoids with beneficial cardiovascular properties. These favorable physiological effects include: antioxidant activity, vasodilation and blood pressure reduction, inhibition of platelet activity, and decreased inflammation. Increasing evidence from experimental and clinical studies using cocoa-derived products and chocolate suggest an important role for these high-flavanol-containing foods in heart and vascular protection.

High-sensitivity C-reactive protein as cardiovascular risk marker in patients with diabetes mellitus

C-reactive protein (CRP) is a liver-derived pattern recognition molecule that is increased in inflammatory states. It rapidly increases within hours after tissue injury, and it is suggested that it is part of the innate immune system and contributes to host defense. Since cardiovascular disease is at least in part an inflammatory process, CRP has been investigated in the context of arteriosclerosis and subsequent vascular disorders. Based on multiple epidemiological and intervention studies, minor CRP elevation [high-sensitivity CRP (hsCRP)] has been shown to be associated with future major cardiovascular risk (hsCRP:<1 mg/L=low risk; 1-3 mg/L=intermediate risk; 3-10 mg/L=high risk; >10 mg/L=unspecific elevation). It is recommended by the American Heart Association that patients at intermediate or high risk of coronary heart disease may benefit from measurement of hsCRP with regard to their individual risk prediction. Elevation of hsCRP is associated with increased risk of type 2 diabetes development in patients with all levels of metabolic syndrome. In type 1 and type 2 diabetes mellitus, hemoglobin A1c significantly correlates with hsCRP levels and future cardiovascular risk. Also, hsCRP levels increase with the stage of beta-cell dysfunction and insulin resistance. Non-diabetes drugs that have been shown to reduce hsCRP concentrations include aspirin, statins, cyclooxygenase-2 inhibitors, and fibrates. Recent intervention studies have also demonstrated the distinct efficacy of different anti-diabetes treatments on a variety of cardiovascular risk markers. Intensive insulin therapy may reduce inflammation, but this effect may be influenced by the degree of weight gain. Treatment with peroxisome proliferator-activated receptor gamma has lead to substantial reduction of hsCRP and other cardiovascular risk markers in several comparator studies. Since this effect was shown to be independent of the degree of glycemic improvement, it can be regarded as a classspecific effect. Whether these findings translate into a reduction of overall cardiovascular mortality will soon be shown by the currently running thiazolidinedione outcome studies. Positive results in these trials will further strengthen the value and acceptance of hsCRP, which is recommended as a predictive laboratory marker for cardiovascular disease risk also in patients with diabetes mellitus.

Raised Plasma Soluble P-Selectin in Peripheral Arterial Occlusive Disease Enhances Leukocyte Adhesion

Raised levels of soluble P-selectin (sP-selectin) have been reported in the plasma of patients with vascular diseases; however, the functional importance of this ligand remains unclear. In this study we have examined a potential role for plasma sP-selectin in regulating neutrophil adhesion in patients with peripheral arterial occlusive disease (PAOD). Patients with PAOD had significantly higher levels of sP-selectin (mean±SD: 73.3±13.0 versus 16.7±6.4 ng/mL) and enhanced whole blood leukocyte adhesion to platelets under shear. To examine whether the raised sP-selectin levels can directly influence leukocyte adhesion, isolated neutrophils were incubated with plasma from PAOD patients before and after immunodepletion of sP-selectin. Neutrophil adhesion to fibrinogen increased 2-fold following incubation with PAOD plasma, which was abrogated on sP-selectin immunodepletion. We subsequently demonstrated that recombinant sP-selectin dose-dependently (75 to 250 ng/mL) increased leukocyte adhesion to fibrinogen and platelet monolayers. This increase was PSGL-1 and Src kinase-dependent and correlated with an increase in sP-selectin-mediated Mac-1 activation. sP-selectin–stimulated neutrophil adhesion to platelet monolayers was inversely correlated with shear, such that at low shear (50 s −1 ) a 92.7%±15.7 increase in adhesion was observed decreasing to 38.5%±11.9 at 150 s −1 and 10.1%±7.4 at 300 s −1 . These studies suggest a potentially important role for sP-selectin in modulating neutrophil adhesion in patients with PAOD, particularly at sites of low shear, where it raises the possibility that raised plasma sP-selectin levels may enhance leukocyte recruitment to vascular injury and promote disease progression.

Integrating Soluble Biomarkers and Imaging Technologies in the Identification of Vulnerable Atherosclerotic Patients

The clinical utility of a biomarker depends on its ability to identify high-risk individuals to optimally manage the patient. A new biomarker would be of clinical value if it is accurate and reliable, provides good sensitivity and specificity, and is available for widespread application. Data are accumulating on the potential clinical utility of integrating imaging technologies and circulating biomarkers for the identification of vulnerable (high-risk) cardiovascular patients. A multi-biomarker strategy consisting of markers of inflammation, hemostasis and thrombosis, proteolysis and oxidative stress, combined with new imaging modalities (optical coherence tomography, virtual histology plus IVUS, PET) can increase our ability to identify such thombosis-prone patients. In an ideal scenario, cardiovascular biomarkers and imaging combined will provide a better diagnostic tool to identify high-risk individuals and also more efficient methods for effective therapies to reduce such cardiovascular risk. However, additional studies are required in order to show that this approach can contribute to improved diagnostic and therapeutic of atherosclerotic disease.