Inflammation and atherosclerosis

The Positive Impact of Bariatric Surgery on Vascular Health

BACKGROUND

Obesity is one of the most prevalent medical conditions in the Western world. There are many risk factors associated with obesity, including cardiovascular and pulmonary risk. Vascular health is not studied in obese patients, and whether obesity has an adverse effect on vascular health in these patients remains unknown.

OBJECTIVE

The first objective is to find a correlation between vascular health and obesity and whether obesity can be classified as a risk factor for vascular health. The second objective is to see if weight loss leads to an improvement in vascular health in patients.

METHODS

The study was conducted with pre- and post-surgical methods at Baylor Scott & White (BSWH) Medical Center, Temple, Texas, USA. Ten patients were approached, consented, and prepared to obtain baseline values through WatchPAT and EndoPAT devices prior to their bariatric surgery. Values obtained include their initial weight, respiratory disturbance index, apnea-hypopnea index, oxygen desaturation index, and degree of endothelial dysfunction via the EndoPAT device. Post-surgery, these values were obtained again and compared using Wilcoxon non-parametric analyses with a level of significance at p < 0.05.

RESULTS

Our study results demonstrate a correlation between obesity and vascular health as endothelial dysfunction is widely seen. In our patients, after bariatric surgery, we saw a significant weight change (31.2% +11.2, p < 0.0001). There was a significant degree of endothelial function improvement after the weight loss (31.2% +34.7, p < 0.04).

CONCLUSION

Our results indicate that there is a correlation between obesity and vascular health, which also correlates with cardiovascular risk. There is a significant reduction in endothelial dysfunction after weight loss. We believe that obesity is a risk factor for vascular health outcomes.

Increased serum levels of fetuin B in patients with coronary artery disease

BACKGROUND

Recent evidence indicates a pivotal role for fetuin B, one of the cystatin superfamily of cysteine protease inhibitors, in the pathogenesis of metabolic diseases. This study investigated whether serum fetuin B levels are associated with the presence of coronary artery disease.

METHODS

Serum fetuin B levels were assessed in 87 patients with coronary artery disease (41 with acute coronary syndromes and 46 with stable angina pectoris) and 87 healthy controls using an enzyme-linked immunosorbent assay. The association of serum fetuin B levels with cardiac risk factors was analyzed.

RESULTS

Serum fetuin B levels were significantly higher in patients with coronary artery disease than those in healthy controls (90.7 ± 32.1 vs. 110.0 ± 32.7 μg/ml, P < 0.001), extremely elevated in group with acute coronary syndromes (115.0 ± 35.2 μg/ml). Pearson correlation analysis showed that serum fetuin B levels were positively associated with the levels of total cholesterol (r = 0.276, P < 0.001), low-density lipoprotein cholesterol (r = 0.363, P < 0.001), and fasting blood glucose (r = 0.159, P < 0.05). In addition, multiple logistic regression analyses revealed that fetuin B was independently associated with the presence of coronary artery disease (OR, 1.019; 95% CI, 1.009 to 1.029; P < 0.001) and acute coronary syndromes (OR, 1.017; 95% CI, 1.006 to 1.028; P < 0.01).

CONCLUSIONS

Our data revealed that high fetuin B levels are associated with the presence of coronary artery disease and acute coronary syndromes, and that fetuin B may serve as a potential biomarker for coronary artery disease.

Triterpenoid saponins with anti-inflammatory activities from Ilex pubescens roots

Seven triterpenoid saponins, named ilexsaponin I-O, along with twelve known ones, were isolated from the roots of Ilex pubescens. The structures of all compounds were elucidated by use of extensive spectroscopic methods (IR, HR-ESI-MS, and 1D and 2D NMR). Sugar residues obtained after acid hydrolysis were identified by TLC and HPLC. The in vitro anti-inflammatory effects of the triterpenoid saponins were also evaluated in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. Among the isolated saponins, seven compounds were shown to inhibit LPS-induced nitric oxide (NO) and prostaglandin E₂ (PGE₂) production by suppressing the expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2), respectively, in LPS-stimulated RAW 264.7 cells. Ilexsaponin I and β-d-glucopyranosyl 3-β-[β-d-xylopyranosyl-(1 → 2)-β-d-glucopyranosyloxy]-olea-12-en-28-oate exerted more potent anti-inflammatory effects than the other compounds tested.

Endothelial dysfunction and vascular disease - a 30th anniversary update

The endothelium can evoke relaxations of the underlying vascular smooth muscle, by releasing vasodilator substances. The best-characterized endothelium-derived relaxing factor (EDRF) is nitric oxide (NO) which activates soluble guanylyl cyclase in the vascular smooth muscle cells, with the production of cyclic guanosine monophosphate (cGMP) initiating relaxation. The endothelial cells also evoke hyperpolarization of the cell membrane of vascular smooth muscle (endothelium-dependent hyperpolarizations, EDH-mediated responses). As regards the latter, hydrogen peroxide (H₂ O₂ ) now appears to play a dominant role. Endothelium-dependent relaxations involve both pertussis toxin-sensitive G_i (e.g. responses to α₂ -adrenergic agonists, serotonin, and thrombin) and pertussis toxin-insensitive G_q (e.g. adenosine diphosphate and bradykinin) coupling proteins. New stimulators (e.g. insulin, adiponectin) of the release of EDRFs have emerged. In recent years, evidence has also accumulated, confirming that the release of NO by the endothelial cell can chronically be upregulated (e.g. by oestrogens, exercise and dietary factors) and downregulated (e.g. oxidative stress, smoking, pollution and oxidized low-density lipoproteins) and that it is reduced with ageing and in the course of vascular disease (e.g. diabetes and hypertension). Arteries covered with regenerated endothelium (e.g. following angioplasty) selectively lose the pertussis toxin-sensitive pathway for NO release which favours vasospasm, thrombosis, penetration of macrophages, cellular growth and the inflammatory reaction leading to atherosclerosis. In addition to the release of NO (and EDH, in particular those due to H₂ O₂ ), endothelial cells also can evoke contraction of the underlying vascular smooth muscle cells by releasing endothelium-derived contracting factors. Recent evidence confirms that most endothelium-dependent acute increases in contractile force are due to the formation of vasoconstrictor prostanoids (endoperoxides and prostacyclin) which activate TP receptors of the vascular smooth muscle cells and that prostacyclin plays a key role in such responses. Endothelium-dependent contractions are exacerbated when the production of nitric oxide is impaired (e.g. by oxidative stress, ageing, spontaneous hypertension and diabetes). They contribute to the blunting of endothelium-dependent vasodilatations in aged subjects and essential hypertensive and diabetic patients. In addition, recent data confirm that the release of endothelin-1 can contribute to endothelial dysfunction and that the peptide appears to be an important contributor to vascular dysfunction. Finally, it has become clear that nitric oxide itself, under certain conditions (e.g. hypoxia), can cause biased activation of soluble guanylyl cyclase leading to the production of cyclic inosine monophosphate (cIMP) rather than cGMP and hence causes contraction rather than relaxation of the underlying vascular smooth muscle.

Potential Role of Lipometabolism-Related MicroRNAs in Peripheral Blood Mononuclear Cells as Biomarkers for Coronary Artery Disease

Aim: To explore the relationship between lipometabolism-related microRNAs (miRNAs) in peripheral blood mononuclear cells (PBMCs) and the presence of coronary artery disease (CAD).

Methods: In the present study, 161 stable CAD patients and 149 health controls were enrolled. The expression levels of seven miRNAs (miR-21, miR-24, miR-29a, miR-33a, miR-34a, miR-103a, and miR-122) in PBMCs were qualified by quantitative real-time polymerase chain reaction (qRT-PCR). The miRNA markers that showed significant difference between the two groups were used for further analysis. The risk of miRNA contributing to the presence of CAD was estimated by univariate and multivariate logistic regression models. The area under the receiver operating characteristic curve (AUC) was used to evaluate diagnostic accuracy.

Results: The expression levels of miR-24, miR-33a, miR-103a, and miR-122 in PBMCs were significantly increased in CAD patients compared with controls and were significantly correlated with blood lipids in both CAD patients and controls. The increased levels of miR-24 (adjusted OR = 1.32, 95% CI 1.07–1.62, P = 0.009), miR-33a (adjusted OR = 1.57, 95% CI 1.35–1.81, P < 0.001), miR-103a (adjusted OR = 1.01, 95% CI 1.01–1.02, P < 0.001), and miR-122 (adjusted OR = 1.03, 95% CI 1.01–1.04, P < 0.001) were associated with risk of CAD. We identified a miRNA panel (miR-24, miR-33, miR-103a, and miR-122) that provided a high diagnostic accuracy of CAD (AUC= 0.911, 95% CI 0.880–0.942).

Conclusion: The increased expression levels of miR-24, miR-33a, miR-103a, and miR-122 in PBMCs are associated with risk of CAD. A panel of the four miRNAs has considerable clinical value in diagnosing stable CAD.

Plasma miR-10a: A Potential Biomarker for Coronary Artery Disease

Aims. MicroRNAs (miRNAs) are involved in the pathogenesis of coronary artery disease (CAD). The objective of this study is to determine plasma levels of miR-10a in CAD and analyze its association with the severity of CAD. Materials and Methods. Plasma miR-10a levels in 60 CAD patients including stable angina pectoris (SAP) (n = 29), unstable angina pectoris (UAP) or non-ST elevation myocardial infarction (MI) (NSTEMI) (n = 17), or ST elevation MI (STEMI) (n = 14) and 20 non-CAD subjects were assessed by real-time polymerase chain reaction (qRT-PCR), and associations of miR-10a levels with risk factors of CAD and its severity were analyzed. Results. The qRT-PCR results showed that plasma miR-10a levels were decreased in CAD patients, and CAD with high SYNTAX scores or STEMI was significantly associated with lower miR-10a levels. Conclusions. Lower plasma miR-10a levels were negatively associated with the presence as well as severity of CAD, and plasma miR-10a can act as a potential biomarker for estimating the presence and severity of CAD.

Association of plasma MiR-17-92 with dyslipidemia in patients with coronary artery disease

Circulating microRNAs (miRNAs) have already been proposed as sensitive and informative biomarkers for the diagnosis of multiple diseases. We investigated the miRNA expression patterns in plasma samples of patients with coronary artery disease (CAD) and explored the potential functions of certain miRNAs.Deep sequencing analysis was performed to determine the miRNA expression profiles using RNA samples isolated from 20 healthy subjects and 20 patients with CAD. Quantitative reverse transcription polymerase chain reaction was applied to confirm the differential expression of the miR-17-92 cluster in 81 patients and 50 healthy volunteers. The association between the miR-17-92 cluster and clinical characteristics of patients with CAD were analyzed using SPSS16.0, SPSS Inc, Chicago, IL.Hundreds of miRNAs were detected and most members from the miR-17-92 cluster and its paralogs, including miR-18a, miR-92a, miR-106b, and miR-17, exhibited differential expression in the plasma of patients with CAD compared with controls. Moreover, these miRNAs were found widely related to the blood lipids in the patients with CAD, as miR-17 was positively correlated with total cholesterol, low-density lipoprotein cholesterol, and apolipoprotein B, while miR-92a was found positively related to high-density lipoprotein cholesterol (HDL-C) but negatively related to lipoprotein-a. Additionally, miR-106b was positively related to HDL-C and apolipoprotein A-I.Taken together with existing evidence from mechanistic studies, the current results of our study support a relationship between the miR-17-92 family and lipid metabolism, which merits further study.

Estrogen biology: new insights into GPER function and clinical opportunities

Estrogens play an important role in the regulation of normal physiology, aging and many disease states. Although the nuclear estrogen receptors have classically been described to function as ligand-activated transcription factors mediating genomic effects in hormonally regulated tissues, more recent studies reveal that estrogens also mediate rapid signaling events traditionally associated with G protein-coupled receptors. The G protein-coupled estrogen receptor GPER (formerly GPR30) has now become recognized as a major mediator of estrogen's rapid cellular effects throughout the body. With the discovery of selective synthetic ligands for GPER, both agonists and antagonists, as well as the use of GPER knockout mice, significant advances have been made in our understanding of GPER function at the cellular, tissue and organismal levels. In many instances, the protective/beneficial effects of estrogen are mimicked by selective GPER agonism and are absent or reduced in GPER knockout mice, suggesting an essential or at least parallel role for GPER in the actions of estrogen. In this review, we will discuss recent advances and our current understanding of the role of GPER and the activity of clinically used drugs, such as SERMs and SERDs, in physiology and disease. We will also highlight novel opportunities for clinical development towards GPER-targeted therapeutics, for molecular imaging, as well as for theranostic approaches and personalized medicine.

A significant correlation between C - reactive protein levels in blood monocytes derived macrophages versus content in carotid atherosclerotic lesions

Background

Atherosclerosis is a complex disease involving different cell types, including macrophages that play a major role in the inflammatory events occurring in atherogenesis. C-Reactive Protein (CRP) is a sensitive systemic marker of inflammation and was identified as a biomarker of cardiovascular diseases. Histological studies demonstrate CRP presence in human atherosclerotic lesions, and we have previously shown that macrophages express CRP mRNA. CRP could be locally secreted in the atherosclerotic lesion by arterial macrophages and local regulation of CRP could affect its pro-atherogenic effects. Moreover, human blood derived macrophages (HMDM) expression of CRP could reflect atherosclerotic lesion secretion of CRP.

Methods

Ten type 2 diabetic patients and ten non-diabetic patients scheduled to undergo carotid endarterectomy were enrolled in this study, and their blood samples were used for serum CRP, lipid determination, and for preparation of HMDM further analyzed for their CRP mRNA expression and CRP content. Carotid lesions obtained from the patients were analyzed for their CRP and interleukin 6 (IL-6) content by immunohistochemistry.

Results

Lesions from diabetic patients showed substantially higher CRP levels by 62% (p = 0.05) than lesions from non diabetic patients, and CRP staining that co-localized with arterial macrophages. CRP carotid lesion levels positively correlated with CRP mRNA expression (r² = 0.661) and with CRP content (r² = 0.611) in the patient’s HMDM.

Conclusions

Diabetes up-regulated carotid plaques CRP levels and CRP measurements in HMDM could reflect atherosclerotic lesion macrophages secretion of CRP. Understanding the regulation of locally produced macrophage CRP in the arterial wall during atherogenesis could be of major importance in identifying the underlying mechanisms of inflammatory response pathways during atherogenesis.

Evaluation of antinociceptive and antioxidant properties of 3-[4-(3-trifluoromethyl-phenyl)-piperazin-1-yl]-dihydrofuran-2-one in mice

The aim of this study was to evaluate the influence of 3-[4-(3-trifluoromethyl-phenyl)-piperazin-1-yl]-dihydrofuran-2-one (LPP1) on nociceptive thresholds in mouse models of persistent pain. Influence of LPP1 on motor coordination and its antioxidant capacity in mouse brain tissue homogenates were also assessed. Pain sensitivity thresholds in animals treated with LPP1 were established using 5 % formalin solution in normoglycemic mice and in streptozotocin (STZ)-treated diabetic mice in the von Frey, hot plate, innocuous, and noxious cold water tests (water at 10 °C and 4 °C, respectively). Motor deficits were assessed in the rotarod test, whereas antioxidant capacities were evaluated using ferric reducing ability of plasma (FRAP) assay, catalase (CAT), and superoxide dismutase (SOD) activities. LPP1was antinociceptive in both phases of the formalin test, in particular, in the late phase (at doses 0.9-30 mg/kg for 66-99 % vs. control normoglycemic mice) and in a statistically significant manner increased nociceptive thresholds in response to mechanical, heat, and noxious cold stimulation in neuropathic mice (at 30 mg/kg for 274, 192, and 316 %, respectively vs. diabetic control). LPP1 did not impair motor coordination of mice in the rotarod revolving at 6 or 18 rpm. In brain tissue homogenates, it demonstrated antioxidant capacity in FRAP assay and increased SOD activity for 63 % (acute administration) and 28 % (chronic administration) vs. control. No influence on CAT activity was observed. LPP1 has significant antinociceptive properties in the formalin model and elevates pain thresholds in neuropathic mice. It has antioxidant capacity and is devoid of negative influence on animals' motor coordination.

Identification of naturally occurring fatty acids of the myelin sheath that resolve neuroinflammation

Lipids constitute 70% of the myelin sheath, and autoantibodies against lipids may contribute to the demyelination that characterizes multiple sclerosis (MS). We used lipid antigen microarrays and lipid mass spectrometry to identify bona fide lipid targets of the autoimmune response in MS brain, and an animal model of MS to explore the role of the identified lipids in autoimmune demyelination. We found that autoantibodies in MS target a phosphate group in phosphatidylserine and oxidized phosphatidylcholine derivatives. Administration of these lipids ameliorated experimental autoimmune encephalomyelitis by suppressing activation and inducing apoptosis of autoreactive T cells, effects mediated by the lipids' saturated fatty acid side chains. Thus, phospholipids represent a natural anti-inflammatory class of compounds that have potential as therapeutics for MS.

C-reactive protein promotes adhesion of monocytes to endothelial cells via NADPH oxidase-mediated oxidative stress

Enhanced monocyte adhesion to endothelial cells is an early event in atherogenesis. It has been shown that C-reactive protein (CRP) plays a key role in atherogenesis. Here, we investigated the effects of CRP on monocyte-endothelial cell adhesion and tested the hypothesis that NADPH oxidase (NOX)-mediated oxidative stress might play a key role in CRP-induced monocyte-endothelial cell adhesion. Firstly, 36 patients with carotid intima-media thickness (IMT) incrassation and 34 controls were enrolled in this study. The levels of glucose, lipids, CRP, monocyte chemotractant protein (MCP-1), malondialdehyde (MDA), and protein carbonylation were analyzed. The results showed that carotid IMT was associated with abnormal lipid metabolism, including elevated CRP, triglycerides (TG) (P < 0.01) and decreased high density lipoprotein (HDL) level (P < 0.05). The levels of CRP and MCP-1 in patients with carotid IMT incrassation were increased compared with the controls (P < 0.01). Moreover, patients with carotid IMT incrassation displayed enhanced MDA and protein carbonylation levels (P < 0.01), accompanied by activation and up-regulation of NOX in monocytes (P < 0.05) compared with the controls. The monocytes isolated from five healthy donors were used for in vitro experiments. Reactive oxygen species (ROS) production and NOX expression in monocytes were examined. The results also indicated that CRP could promote the adhesion of monocyte-endothelial cell by up-regulation of MCP-1 expression (P < 0.05). Importantly, NFκ B and p38 MAPK signaling pathways, which were activated by NOX-derived ROS, were involved in CRP-induced monocyte-endothelial cell adhesion and up-regulation of MCP-1 expression. These data suggested that CRP could promote the adhesion of monocytes to endothelial cells via NOX-mediated oxidative stress. J. Cell. Biochem. 113: 857-867, 2012. © 2011 Wiley Periodicals, Inc.

Childhood obesity: a life-long health risk

Childhood obesity has become major health concern for physicians, parents, and health agencies around the world. Childhood obesity is associated with an increased risk for other diseases not only during youth but also later in life, including diabetes, arterial hypertension, coronary artery disease, and fatty liver disease. Importantly, obesity accelerates atherosclerosis progression already in children and young adults. With regard to pathophysiological changes in the vasculature, the striking similarities between physiological changes related to aging and obesity-related abnormalities are compatible with the concept that obesity causes "premature" vascular aging. This article reviews factors underlying the accelerated vascular disease development due to obesity. It also highlights the importance of recognizing childhood obesity as a disease condition and its permissive role in aggravating the development of other diseases. The importance of childhood obesity for disease susceptibility later in life, and the need for prevention and treatment are also discussed.

Childhood obesity: a life-long health risk

Childhood obesity has become major health concern for physicians, parents, and health agencies around the world. Childhood obesity is associated with an increased risk for other diseases not only during youth but also later in life, including diabetes, arterial hypertension, coronary artery disease, and fatty liver disease. Importantly, obesity accelerates atherosclerosis progression already in children and young adults. With regard to pathophysiological changes in the vasculature, the striking similarities between physiological changes related to aging and obesity-related abnormalities are compatible with the concept that obesity causes "premature" vascular aging. This article reviews factors underlying the accelerated vascular disease development due to obesity. It also highlights the importance of recognizing childhood obesity as a disease condition and its permissive role in aggravating the development of other diseases. The importance of childhood obesity for disease susceptibility later in life, and the need for prevention and treatment are also discussed.

Therapeutic potential of endothelin receptor antagonists for chronic proteinuric renal disease in humans

Diabetes and arterial hypertension continue to be the main causes of chronic renal failure in 2010, with a rising prevalence in part due to the worldwide obesity epidemic. Proteinuria is a main feature of chronic renal disease and mediated by defects in the glomerular filtration barrier and is as a good predictor of cardiovascular events. Indeed, chronic renal disease due to glomerulosclerosis is one of the important risk factors for the development of coronary artery disease and stroke. Glomerulosclerosis develops in response to inflammatory activation and increased growth factor production. Preclinical and first preliminary clinical studies provide strong evidence that endogenous endothelin-1 (ET-1), a 21-amino-acid peptide with strong growth-promoting and vasoconstricting properties, plays a central role in the pathogenesis of proteinuria and glomerulosclerosis via activation of its ET(A) subtype receptor involving podocyte injury. These studies have not only shown that endothelin participates in the disease processes of hypertension and glomerulosclerosis but also that features of chronic renal disease such as proteinuria and glomerulosclerosis are reversible processes. Remarkably, the protective effects of endothelin receptors antagonists (ERAs) are present even on top of concomitant treatments with inhibitors of the renin-angiotensin system. This review discusses current evidence for a role of endothelin for proteinuric renal disease and podocyte injury in diabetes and arterial hypertension and reviews the current status of endothelin receptor antagonists as a potential new treatment option in renal medicine.

Endothelial dysfunction and vascular disease

The endothelium can evoke relaxations (dilatations) of the underlying vascular smooth muscle, by releasing vasodilator substances. The best characterized endothelium-derived relaxing factor (EDRF) is nitric oxide (NO). The endothelial cells also evoke hyperpolarization of the cell membrane of vascular smooth muscle (endothelium-dependent hyperpolarizations, EDHF-mediated responses). Endothelium-dependent relaxations involve both pertussis toxin-sensitive G(i) (e.g. responses to serotonin and thrombin) and pertussis toxin-insensitive G(q) (e.g. adenosine diphosphate and bradykinin) coupling proteins. The release of NO by the endothelial cell can be up-regulated (e.g. by oestrogens, exercise and dietary factors) and down-regulated (e.g. oxidative stress, smoking and oxidized low-density lipoproteins). It is reduced in the course of vascular disease (e.g. diabetes and hypertension). Arteries covered with regenerated endothelium (e.g. following angioplasty) selectively loose the pertussis toxin-sensitive pathway for NO release which favours vasospasm, thrombosis, penetration of macrophages, cellular growth and the inflammatory reaction leading to atherosclerosis. In addition to the release of NO (and causing endothelium-dependent hyperpolarizations), endothelial cells also can evoke contraction (constriction) of the underlying vascular smooth muscle cells by releasing endothelium-derived contracting factor (EDCF). Most endothelium-dependent acute increases in contractile force are due to the formation of vasoconstrictor prostanoids (endoperoxides and prostacyclin) which activate TP receptors of the vascular smooth muscle cells. EDCF-mediated responses are exacerbated when the production of NO is impaired (e.g. by oxidative stress, ageing, spontaneous hypertension and diabetes). They contribute to the blunting of endothelium-dependent vasodilatations in aged subjects and essential hypertensive patients.