The antiatherogenic effect of new biocompatible cationically modified polysaccharides: chitosan and pullulan - the comparison study

Pullulan and chitosan are biocompatible polysaccharides obtained from natural sources with many biomedical applications. Cationically modified polymers, such as chitosan and pullulan after covalent attachment of glycidyltrimethylammonium chloride (GTMAC), showed beneficial biological properties. In the present study, it was clearly demonstrated and confirmed that both cationically modified polysaccharides (chitosan-GTMAC and pullulan-GTMAC) have the antiatherosclerotic potential by inhibition of atherosclerotic plaque development and controlling the expression of genes involved in lipid metabolism. It has also been shown that the cationically modified chitosan (HTCC) at a dose of 200 mg/kg b.w./day in male apoE-knockout mice acted as hypolipidaemic agent. It was observed that a statistically significant decrease in low-density lipoprotein (LDL) cholesterol level by 32% occurred under the influence of HTCC at a dose of 200 mg/kg b.w./day after 16 weeks of the experiment compared to the control group of apoE(-/-) mice. Moreover, under the influence of cationically modified chitosan administered orally to female apoE-knockout mice at a dose of 300 mg/kg b.w./day for 18 weeks a statistically significant reduction by 33% in the area of atherosclerotic plaque was observed compared to the control group, i.e., apoE-knockout mice whose diet was not supplemented with the cationically modified polysaccharide. Current in vivo studies connected with cationically modified pullulan showed a statistically significant 22% reduction of the area of atherosclerotic plaque in the apoE(-/-) mice fed with a feed containing Pull-GTMAC at a dose of 500 mg/kg b.w./day for 18 weeks in comparison to the control group of apoE-knockout mice. In the in vitro studies it was also shown that cationically modified chitosan acted therapeutically by reduction of the level of the expression of human 3-hydroxy-3-methylglutaryl-CoA reductase (human HMG-CoAR) after 24 hours of incubation with HepG2 cells. However, cationically modified pullulan did not show this effect in the experiment on HepG2 cell line. On the other hand, Pull-GTMAC caused a statistically significant increase in insulin induced gene 1 (INSIG1) expression and increase in mRNA level of LDL receptor in brown fat tissue of female apoE-knockout mice after oral administration with feed at a dose of 300 mg/kg b.w./day for 18 weeks in comparison to the control group of apoE(-/-) mice, that was crearly demonstrated the effect of cationically modified pullulan on the expression of lipid metabolism genes in in vivo conditions. In the present article we have shown for first time that cationically modified pullulan and chitosan have some similarities in their antiatherogenic action but there are also some minor differences in mechanism of their effect on lipid metabolism.

Vasodilatory Efficacy and Impact of Papaverine on Endothelium in Radial Artery Predilatation for CABG Surgery: in Search for Optimal Concentration

OBJECTIVE

The aim of this study was to compare the efficacy of two different papaverine concentrations (0.5 mg/ml and 2 mg/ml) for vasospasm prevention and their impact on endothelium integrity.

METHODS

We have studied distal segments of radial arteries obtained by no-touch technique from coronary artery bypass graft (CABG) patients (n=10). The vasodilatory effect of papaverine (concentrations of 0.5 mg/ml and 2 mg/ml) was assessed in vitro, in isometric tension studies using ex vivo myography (organ bath technique) and arterial rings precontracted with potassium chloride (KCl) and phenylephrine. The impact of papaverine on endothelial integrity was studied by measurement of the percentage of vessel's circumference revealing CD34 endothelial marker.

RESULTS

2 mg/ml papaverine concentration showed stronger vasodilatatory effect than 0.5 mg/ml, but it caused significantly higher endothelial damage. Response to KCl was 7.35±3.33 mN for vessels protected with papaverine 0.5 mg/ml and 2.66±1.96 mN when papaverine in concentration of 2 mg/ml was used. The histological examination revealed a significant difference in the presence of undamaged endothelium between vessels incubated in papaverine 0.5 mg/ml (72.86±9.3%) and 2 mg/ml (50.23±13.42%), P=0.002.

CONCLUSION

Papaverine 2 mg/ml caused the higher endothelial damage. Concentration of 0.5 mg/ml caused better preservation of the endothelial lining.

Differences in plasma fibrin clot composition in patients with thrombotic antiphospholipid syndrome compared with venous thromboembolism

The prothrombotic fibrin clot phenotype has been reported in patients with thrombotic antiphospholipid syndrome (APS) and venous thromboembolism (VTE). Protein composition of plasma fibrin clots in APS has not been studied. We evaluated 23 patients with thrombotic APS, 19 with VTE alone, and 20 well-matched controls. A proteomic analysis of fibrin clots generated from citrated plasma was based on liquid chromatography-mass spectrometry. Plasma levels of thrombospondin-1 (TSP1), apolipoprotein(a), A-I, and B-100, complement components (C)3a, C5b-C9, histidine-rich glycoprotein (HRG), and prothrombin were evaluated using immunoenzymatic tests. In plasma fibrin clots of APS patients, compared with VTE subjects and controls, we identified decreased amounts of (pro)thrombin, antithrombin-III, apolipoprotein A-I, and HRG with no differences in plasma levels of antithrombin, prothrombin, along with lower plasma HRG and apolipoprotein A-I. In APS patients, plasma HRG positively correlated with amounts of clot-bound HRG, while apolipoprotein A-I was inversely associated with clot-bound levels of this protein. The most predominant proteins within the clots of APS patients were bone marrow proteoglycan, C5-C9, immunoglobulins, apolipoprotein B-100, platelet-derived proteins, and TSP1. Our study is the first to demonstrate differences in the protein composition of fibrin clots generated from plasma of thrombotic APS patients versus those with VTE alone.

Fibrinolytic Activity and the Effects of Beta-Pyridylcarbinol (Ronicol) in Patients with Arteriosclerosis Obliterans

Twenty-one patients with arteriosclerosis obliterans of lower extremities were treated with beta-pyridylcarbinol (Ronicol) for five weeks. The long-term therapy with beta-pyridylcarbinol did not influence platelet aggregability. Activation of the fibrinolytic system was observed. This fibrinolytic effect of Ronicol was abolished in patients treated with aspirin. In most cases a slight clinical improvement was seen, manifested by elongation of pain-free walking distance and increased blood flow in affected limbs. It is concluded that the therapeutic effect of Ronicol in humans may be partly mediated by the release of endogenous prostacyclin.

On the Mechanism of Thrombolytic Action of Thromboxane Synthetase Inhibitors

Using our in vivo model for studying drugs which prevent deposition of thrombi or dissipate thrombi formed in extracorporeal circulation over a collagen strip superfused with arterial blood of anaesthetized and heparinized cats, we have found that dazoxiben - a thromboxane synthetase inhibitor - possesses not only antithrombotic but also thrombolytic potency in vivo (ED50 = 3.8 mg/kg i.v.). The thrombolytic potency of dazoxiben was antagonized by aspirin at a dose of 50 mg/kg i.v. Moreover, dazoxiben stimulated the generation of prostacyclin in isolated rat aortic slices incubated in platelet rich plasma, but not in platelet poor plasma. It is suggested that the thrombolytic potency of thromboxane synthetase inhibitors after their systemic administration is associated with the release of prostacyclin and/or prostacyclin-stable metabolites by the vascular endothelium owing to feeding of prostacyclin synthetase with prostaglandin endoperoxides acumulated in platelets following the inhibition of thromboxane synthetase.

Optimization of quantitative proteomic analysis of clots generated from plasma of patients with venous thromboembolism

Background

It is well known that fibrin network binds a large variety of proteins, including inhibitors and activators of fibrinolysis, which may affect clot properties, such as stability and susceptibility to fibrinolysis. Specific plasma clot composition differs between individuals and may change in disease states. However, the plasma clot proteome has not yet been in-depth analyzed, mainly due to technical difficulty related to the presence of a highly abundant protein—fibrinogen and fibrin that forms a plasma clot.

Methods

The aim of our study was to optimize quantitative proteomic analysis of fibrin clots prepared ex vivo from citrated plasma of the peripheral blood drawn from patients with prior venous thromboembolism (VTE). We used a multiple enzyme digestion filter aided sample preparation, a multienzyme digestion (MED) FASP method combined with LC–MS/MS analysis performed on a Proxeon Easy-nLC System coupled to the Q Exactive HF mass spectrometer. We also evaluated the impact of peptide fractionation with pipet-tip strong anion exchange (SAX) method on the obtained results.

Results

Our proteomic approach revealed 476 proteins repeatedly identified in the plasma fibrin clots from patients with VTE including extracellular vesicle-derived proteins, lipoproteins, fibrinolysis inhibitors, and proteins involved in immune responses. The MED FASP method using three different enzymes: LysC, trypsin and chymotrypsin increased the number of identified peptides and proteins and their sequence coverage as compared to a single step digestion. Peptide fractionation with a pipet-tip strong anion exchange (SAX) protocol increased the depth of proteomic analyses, but also extended the time needed for sample analysis with LC–MS/MS.

Conclusions

The MED FASP method combined with a label-free quantification is an excellent proteomic approach for the analysis of fibrin clots prepared ex vivo from citrated plasma of patients with prior VTE.

Electronic supplementary material

The online version of this article (10.1186/s12014-017-9173-x) contains supplementary material, which is available to authorized users.

Anti-Atherosclerotic Action of Agmatine in ApoE-Knockout Mice

Atherosclerosis is an inflammatory disease in which dysfunction of mitochondria play an important role, and disorders of lipid management intensify this process. Agmatine, an endogenous polyamine formed by decarboxylation of arginine, exerts a protective effect on mitochondria and modulates fatty acid metabolism. We investigated the effect of exogenous agmatine on the development of atherosclerosis and changes in lipid profile in apolipoprotein E knockout (apoE-/-) mice. Agmatine caused an approximate 40% decrease of atherosclerotic lesions, as estimated by en face and cross-section methods with an influence on macrophage but not on smooth muscle content in the plaques. Agmatine treatment did not changed gelatinase activity within the plaque area. What is more, the action of agmatine was associated with an increase in the number of high density lipoproteins (HDL) in blood. Real-Time PCR analysis showed that agmatine modulates liver mRNA levels of many factors involved in oxidation of fatty acid and cholesterol biosynthesis. Two-dimensional electrophoresis coupled with mass spectrometry identified 27 differentially expressed mitochondrial proteins upon agmatine treatment in the liver of apoE-/- mice, mostly proteins related to metabolism and apoptosis. In conclusion, prolonged administration of agmatine inhibits atherosclerosis in apoE-/- mice; however, the exact mechanisms linking observed changes and elevations of HDL plasma require further investigation.

The influence of AICAR - direct activator of AMP-activated protein kinase (AMPK) - on liver proteome in apoE-knockout mice

There is a growing body of evidence that altered functioning of apoE may aggravate cellular energy homeostasis and stress response, leading to oxidative stress, mitochondrial dysfunction, endoplasmic reticulum (ER) stress and inflammation, leading to hypercholesterolemia, dyslipidemia, liver steatosis and neurodegeneration. One of the key cellular responses to mitochondria and ER-stress related processes and cellular energy imbalance is AMP-activated protein kinase (AMPK), considered as a cellular master energy sensor and critical regulator of mitochondrial homeostasis. The aim of our study was to use differential proteomics and transcriptomics approach to elucidate the effect of direct AMPK activator AICAR on liver proteome in apoE^-/- mice - experimental model of atherosclerosis and moderate nonalcoholic steatosis. We applied Isobaric Tags for Relative and Absolute Quantitation (iTRAQ) labeling and two-dimensional chromatography coupled with mass spectrometry (2DLC-MS/MS) MudPIT strategy, as well as RT-PCR to investigate the changes in mitochondrial and cytosolic proteins and transcripts expression in 6-month old AICAR-treated apoE^-/-. AICAR elicited induction of proteins related to mitochondrial β-oxidation, protein degradation and energy producing pathways (i.a. tricarboxylic acid cycle members and mitochondrial adenylate kinase 2). On the other hand, AICAR repressed inflammatory and pro-apoptotic markers in the apoE^-/- mice liver, alongside reduction in several peroxisomal proteins, possibly suggesting induction of anti-oxidative pexophagy.

Anti-atherosclerotic effect of the angiotensin 1-7 mimetic AVE0991 is mediated by inhibition of perivascular and plaque inflammation in early atherosclerosis

BACKGROUND AND PURPOSE

Inflammation plays a key role in atherosclerosis. The protective role of angiotensin 1-7 (Ang-(1-7)) in vascular pathologies suggested the therapeutic use of low MW, non-peptide Ang-(1-7) mimetics, such as AVE0991. The mechanisms underlying the vaso-protective effects of AVE0991, a Mas receptor agonist, remain to be explored.

EXPERIMENTAL APPROACH

We investigated the effects of AVE0991 on the spontaneous atherosclerosis in apolipoprotein E (ApoE)-/- mice, in the context of vascular inflammation and plaque stability.

KEY RESULTS

AVE0991 has significant anti-atherosclerotic properties in ApoE-/- mice and increases plaque stability, by reducing plaque macrophage content, without effects on collagen. Using the descending aorta of chow-fed ApoE-/- mice, before significant atherosclerotic plaque develops, we gained insight to early events in atherosclerosis. Interestingly, perivascular adipose tissue (PVAT) and adventitial infiltration with macrophages and T-cells precedes atherosclerotic plaque or the impairment of endothelium-dependent NO bioavailability (a measure of endothelial function). AVE0991 inhibited perivascular inflammation, by reducing chemokine expression in PVAT and through direct actions on monocytes/macrophages inhibiting their activation, characterized by production of IL-1β, TNF-α, CCL2 and CXCL10, and differentiation to M1 phenotype. Pretreatment with AVE0991 inhibited migration of THP-1 monocytes towards supernatants of activated adipocytes (SW872). Mas receptors were expressed in PVAT and in THP-1 cells in vitro, and the anti-inflammatory effects of AVE0991 were partly Mas dependent.

CONCLUSIONS AND IMPLICATIONS

The selective Mas receptor agonist AVE0991 exhibited anti-atherosclerotic and anti-inflammatory actions, affecting monocyte/macrophage differentiation and recruitment to the perivascular space during early stages of atherosclerosis in ApoE-/- mice.

LINKED ARTICLES

This article is part of a themed section on Targeting Inflammation to Reduce Cardiovascular Disease Risk. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.22/issuetoc and http://onlinelibrary.wiley.com/doi/10.1111/bcp.v82.4/issuetoc.

New cationically modified pullulan attenuates atherogenesis and influences lipid metabolism in apoE-knockout mice

Pullulan is a biocompatible polysaccharide obtained from black, yeast-like fungus Aureobasidium pullulans. This polymer is used to deliver various substances to the liver because of its specificity for this organ. Pullulan is internalized into hepatocytes in the process of asialoglycoprotein receptor mediated endocytosis. Recently, by reaction with glycidyltrimethylammonium chloride (GTMAC) we have successfully synthesized a cationically-modified pullulan (Pull-GTMAC). Pull-GTMAC exhibits some unique beneficial effects not found for its native counterpart. In this article we have reported for the first time that Pull-GTMAC administered orally to apoE-knockout mice (murine model of atherosclerosis) at a dose of 300 mg/kg b.w./day for 18 weeks showed anti-atherosclerotic activity reducing the area of atherosclerotic plaque. We have also found that Pull-GTMAC at a dose of 300 mg/kg b.w./day increases both the average daily mass of feces and the average number of droppings excreted by apoE(-/-) mouse in relation to the control sample derived from the mice fed with feed without the tested compound. However, the raw fat content in the feces of apoE-knockout mice was decreased in the group fed with the diet containing Pull-GTMAC towards control group of animals. Pull-GTMAC caused also statistically significant increase of mRNA level for LDL receptor in the apoE(-/-) mice liver after administration at a dose of 300 mg/kg/b.w./day for 18 weeks. However, the compound had no impact on lipid profile in serum of the tested mice. What is more, the studies on HepG2 cell line indicated an antiproliferative potential of cationically modified pullulan after 24 hour and 48 hour of incubation with the polysaccharide. In this paper we have shown for first time that cationically modified pullulan has antiatherogenic potential and influences on lipid metabolism.

Polymorphism in the chemokine receptor 7 gene (CCR7) is associated with previous myocardial infarction in patients undergoing elective coronary angiography

Coronary artery disease (CAD) remains a major cause of death in developed countries. Both environmental and, less known, genetic factors contribute to progression of CAD to myocardial infarction (MI). Immune system is activated in patients with CAD through dendritic cells (DCs), which present plaque antigens to T lymphocytes. Production of proinflammatory cytokines by activated T cells contributes to plaque rupture in MI. Chemokine receptor 7 (CCR7) on DCs is required for their chemotaxis from plaque to lymph nodes. This makes possible an interaction of DCs with T lymphocytes and initiation of specific immune response. We hypothesized that single nucleotide polymorphisms (SNPs) in CCR7 gene locus are associated with previous MI in patients with CAD. To test this hypothesis, we genotyped six SNPs from the CCR7 gene locus in 300 consecutive patients, admitted for elective coronary angiography. We performed univariate-, multivariate- (including potential confounders) and haplotype-based tests of association of SNPs with previous MI and results of angiography. Allele A of rs17708087 SNP was associated with previous MI. This association remained significant after adjustment for age, sex, smoking, hypercholesterolaemia and drugs used by patients (odds ratio 2.13, 95% confidence interval: 1.13-3.86). Therefore, we conclude that CCR7 gene locus harbours a polymorphism that modifies risk of MI in patients with CAD. Replication of this association could be sought in a prospective cohort of initially healthy individuals.

Perindoprilat changes ANG (1-9) production in renal arteries isolated from young spontaneously hypertensive rats after ANG I incubation

We used mass spectrometry to quantitate production of angiotensinogen metabolites in renal artery of 3- and 7-month-old Wistar-Kyoto (WKY) and Spontaneously Hypertensive Rats (SHR). Tissue fragments were incubated for 15 min in oxygenated buffer, with added angiotensin I. Concentrations of angiotensins I (ANG I), II (ANG II), III (ANG III), IV (ANG IV), angiotensin (1-9) [ANG (1-9)], angiotensin (1-7) [ANG (1-7)], and angiotensin (1-5) [ANG (1-5)], excreted into the buffer during experiment, were measured using liquid chromatography-mass spectrometry (LC/MS) and expressed per mg of dry tissue. Effects of pretreatment with 10 microM perindoprilat on the production of ANG I metabolites were quantitated. Background production of any of ANG I metabolites differed neither between WKY and SHR rats nor between 3- and 7-month-old rats. Perindoprilat pretreatment of renal arteries resulted, as expected, in decrease of ANG II production. However, renal arteries of 7-month-old SHR rats were resistant to ACE inhibitor and did not change ANG II production in response to perindoprilat. In renal arteries, taken from 3-month-old rats, pretreated with perindoprilat, incubation with ANG I, resulted in the level of ANG (1-9) significantly higher in SHR than WKY rats. Our conclusion is that in SHR rats, sensitivity of renal artery ACE to perindoprilat inhibition changes with age.

The renin-angiotensin system and its vasoactive metabolite angiotensin-(1-7) in the mechanism of the healing of preexisting gastric ulcers. The involvement of Mas receptors, nitric oxide, prostaglandins and proinflammatory cytokines

The inhibition of angiotensin-converting enzyme (ACE) or the blockade of angiotensin (Ang) AT-1 receptors affords protection against acute gastric mucosal injury, but whether the major metabolite of renin-angiotensin system (RAS), Ang-(1-7), accelerates the healing process of preexisting gastric ulcers remains unknown. Previous studies documented that Ang-(1-7) acting via its own Mas receptor exerts vascular responses opposing those of Ang II. We studied the effects of the Ang-(1-7)/Mas receptor axis on the healing rate of acetic-acid-induced gastric ulcers with or without the blockade of Mas receptors by A 779 and compared it with the effects of activation and blockade of the AT-1 receptor by the treatment with Ang II and losartan, respectively, the inhibition of ACE by lisinopril, the NO/cNOS inhibition by L-NAME and inhibition of prostaglandin/COX system by indomethacin in the presence of Ang-(1-7). Additionally, ex vivo metabolism of Ang I in gastric tissue was assessed by LC/MS method. At day 9 after ulcer induction, the area of these ulcers and the accompanying changes in total gastric blood flow (GBF) were determined as were gastric mucosal blood flow (GMBF) at ulcer margin and gastric oxygen uptake (GVO2). The gastric mucosal expression of mRNAs for constitutive nitric oxide synthase (cNOS), superoxide dismutase (SOD), and pro-inflammatory cytokines interleukin 1β (IL-1β) and tumor necrosis factor alpha (TNF-α) and plasma level of both cytokines were determined by RT-PCR and ELISA. The 9 days treatment with Ang II dose-dependently increased the area of gastric ulcers and this effect was accompanied by a significant fall in the GBF, GVO2 and GMBF at ulcer margin. In contrast, treatment with Ang-(1-7) which produced a significant rise in the luminal content of NO significantly reduced the area of gastric ulcer and significantly increased the GBF, GVO2 and the GMBF at ulcer margin. Similar GMBF changes and significant reduction the area of gastric ulcer was observed in rats with gastric ulcers treated with the agonist of Mas receptor, AVE 0991. These effects of Ang-(1-7) and AVE 0991 were eliminated by blockade of the Mas receptor with A779. Similarly to Ang-(1-7), treatment with losartan or lisinopril significantly reduced the area of gastric ulcers and the accompanying increase in the GMBF at ulcer margin and these effects were significantly attenuated by a concomitant administration of L-NAME and indomethacin. The rate of healing of ulcers was associated with a decrease in ex vivo Ang-(1-7) formation and this effect was attenuated by lisinopril. The treatment with Ang-(1- 7) or AVE 0991 increased the expression of mRNA for cNOS and SOD and downregulated that of IL-1β and TNF-α followed by the decrease in the plasma IL-1β and TNF-α levels. We conclude that the Ang-(1-7)/Mas receptor system accelerates the healing of preexisting gastric ulcers via an increase in the gastric macro- and microcirculations, and an increase in gastric tissue oxygenation. These effects are mediated by PG and NO derived from overexpression of cNOS, an increase in the expression of antioxidizing enzyme SOD 2 and an anti-inflammatory action involving the inhibition of expression and release of pro-inflammatory cytokines IL-1β and TNF-α. Our results seem to underlie the importance of the Ang-(1-7), AT-1 and Mas receptors in the regulation of local vascular and metabolic effects associated with mechanism of gastric ulcer healing.

Exogenous Angiotensin I Metabolism in Aorta Isolated from Streptozotocin Treated Diabetic Rats

Purpose. Products of angiotensin (ANG) I metabolism may predispose to vascular complications of diabetes mellitus. Methods. Diabetes was induced with streptozotocin (75 mg/kg i.p.). Rat aorta fragments, isolated 4 weeks later, were pretreated with perindoprilat (3 μM), thiorphan (3 μM), or vehicle and incubated for 15 minutes with ANG I (1 μM). Products of ANG I metabolism through classical (ANG II, ANG III, and ANG IV) and alternative (ANG (1-9), ANG (1-7), and ANG (1-5)) pathways were measured in the buffer, using liquid chromatography-mass spectrometry. Results. Incubation with ANG I resulted in higher concentration of ANG II (P = 0.02, vehicle pretreatment) and lower of ANG (1-9) (P = 0.048, perindoprilat pretreatment) in diabetes. Preference for the classical pathway is suggested by higher ANG III/ANG (1-7) ratios in vehicle (P = 0.03), perindoprilat (P = 0.02), and thiorphan pretreated (P = 0.02) diabetic rat. Within the classical pathway, ratios of ANG IV/ANG II (P = 0.01) and of ANG IV/ANG III (P = 0.049), but not of ANG III/ANG II are lower in diabetes. Conclusions. Diabetes in rats led to preference toward deleterious (ANG II, ANG III) over protective (ANG IV, ANG (1-9), and ANG (1-7)) ANG I metabolites.

The impact of mitochondrial aldehyde dehydrogenase (ALDH2) activation by Alda-1 on the behavioral and biochemical disturbances in animal model of depression

The etiology of depression remains still unclear. Recently, it has been proposed, that mitochondrial dysfunction may be associated with development of mood disorders, such as depression, bipolar disorder and anxiety disorders. Mitochondrial aldehyde dehydrogenase (ALDH2), an enzyme responsible for the detoxification of reactive aldehydes, is considered to exert protective function in mitochondria. We investigated the influence of Alda-1, a small-molecule activator of ALDH2, on depressive- and anxiety-like behaviors in an animal model of depression - the prenatally stressed rats - using behavioral, molecular and proteomic methods. Prolonged Alda-1 administration significantly increased the climbing time, tended to reduce the immobility time and increased the swimming time of the prenatally stressed rats in the forced swim test. Moreover, treatment of prenatally stressed rats with Alda-1 significantly increased number of entries into the open arms of the maze and the time spent therein, as assessed by elevated plus-maze test. Such actions were associated with reduction of plasma 4-HNE-protein content, decrease of TNF-α mRNA and increase of PGC-1α (regulator of mitochondrial biogenesis) mRNA level in the frontal cortex and hippocampus of the prenatally stressed rats as well as with normalization of peripheral immune parameters and significant changes in expression of 6 and 4 proteins related to mitochondrial functions in the frontal cortex and hippocampus, respectively. Collectively, ALDH2 activation by Alda-1 led to a significant attenuation of depressive- and anxiety-like behaviors in the prenatally stressed rats. The pattern of changes suggested mitoprotective effect of Alda-1, however the exact functional consequences of the revealed alterations require further investigation.

Polymorphism rs7023923 and monocyte count in blood donors and coronary artery disease patients

BACKGROUND

The importance of the role of monocytes in coronary artery disease (CAD) is well documented. An increased number of circulating monocytes is associated with higher incidence of CAD. Both environmental and genetic factors influence monocytosis. The latter have been extensively studied since the development of high-throughput genome-wide association studies. Several associations between polymorphisms and monocytosis were found among healthy individuals; the first example was rs7023923. The magnitude of the association of studied polymorphisms with the trait of interest is often confounded by environmental factors and may therefore differ between patient and healthy populations. It is very important to determine the magnitude of the association among patients to predict outcome of the disease, e.g. myocardial infarction.

AIM

To determine whether the magnitude of association of rs7023923 with monocytosis, previously reported among healthy volunteers, is similar in patients in whom diagnosis of CAD was determined during elective coronarography.

METHODS AND RESULTS

Leucocytosis and neutrophilocytosis were higher among patients with CAD, while thrombocytosis was lower. Monocyte count did not differ among the studied groups (p = 0.25). We confirmed the association of rs7023923 with monocytosis among healthy blood donors (p = 0.0156) but not among patients admitted for elective coronarography (p = 0.61). Inclusion of the age and sex of patients in the statistical model did not modify the results.

CONCLUSIONS

Our data suggest that translation of the results of genetic association with the studied traits from healthy to patient population should be implemented with caution. It is possible that numerous environmental factors, which discriminate healthy volunteers from CAD patients, confound the magnitude of genetic associations and make interpretation of the data in patients less clear.

Significant deterioration of anti-atherogenic efficacy of nebivolol in a double (apolipoprotein E and endothelial nitric oxide synthase) knockout mouse model of atherosclerosis in comparison to single (apolipoprotein E) knockout model

Anti-atherogenic action of nebivolol in apolipoprotein E (apoE)-single knockout mouse model can be explained by its beneficial effect on endothelium, especially on endothelial nitric oxide synthase (eNOS). We, therefore, decided to use apoE and eNOS-double knockout mouse model to confirm that mechanism of nebivolol beneficial action. In apoE-single knockout mice, lesion area measured by "cross-section" of aortic roots was 79,244 ± 6,143 μm(2) in the control group versus 65,347 ± 6,152 μm(2) in nebivolol-treated group (P<0.05). However, in apoE and eNOS-double knockout mice, lesion area measured by "cross-section" of aortic roots was 92,319 ± 8,876 μm(2) in the control group versus 98,609 ± 9,164 μm(2) in nebivolol-treated group (P>0.05). The comparison between apoE-single knockout mice and apoE & eNOS-double knockout mice without treatment also showed statistically significant difference: 81,232 ± 8,264 μm(2) versus 92,319 ± 8,876 μm(2) (P<0.05). This is the first report that describes the effect of nebivolol on atherogenesis in apoE and eNOS-double knockout mice, proving directly the necessity of the presence of eNOS in endothelium for nebivolol to show its an anti-atherogenic potency.

Mitochondrial aldehyde dehydrogenase activation by Alda-1 inhibits atherosclerosis and attenuates hepatic steatosis in apolipoprotein E-knockout mice

Background

Mitochondrial dysfunction has been shown to play an important role in the development of atherosclerosis and nonalcoholic fatty liver disease (NAFLD). Mitochondrial aldehyde dehydrogenase (ALDH2), an enzyme responsible for the detoxification of reactive aldehydes, is considered to exert protective function in mitochondria. We investigated the influence of Alda‐1, an activator of ALDH2, on atherogenesis and on the liver steatosis in apolipoprotein E knockout (apoE^−/−) mice.

Methods and Results

Alda‐1 caused decrease of atherosclerotic lesions approximately 25% as estimated by “en face” and “cross‐section” methods without influence on plasma lipid profile, atherosclerosis‐related markers of inflammation, and macrophage and smooth muscle content in the plaques. Plaque nitrotyrosine was not changed upon Alda‐1 treatment, and there were no changes in aortic mRNA levels of factors involved in antioxidative defense, regulation of apoptosis, mitogenesis, and autophagy. Hematoxylin/eosin staining showed decrease of steatotic changes in liver of Alda‐1‐treated apoE^−/− mice. Alda‐1 attenuated formation of 4‐hydroxy‐2‐nonenal (4‐HNE) protein adducts and decreased triglyceride content in liver tissue. Two‐dimensional electrophoresis coupled with mass spectrometry identified 20 differentially expressed mitochondrial proteins upon Alda‐1 treatment in liver of apoE^−/− mice, mostly proteins related to metabolism and oxidative stress. The most up‐regulated were the proteins that participated in beta oxidation of fatty acids.

Conclusions

Collectively, Alda‐1 inhibited atherosclerosis and attenuated NAFLD in apoE^−/− mice. The pattern of changes suggests a beneficial effect of Alda‐1 in NAFLD; however, the exact liver functional consequences of the revealed alterations as well as the mechanism(s) of antiatherosclerotic Alda‐1 action require further investigation.

GTP cyclohydrolase I gene polymorphisms are associated with endothelial dysfunction and oxidative stress in patients with type 2 diabetes mellitus

BACKGROUND

The genetic background of atherosclerosis in type 2 diabetes mellitus (T2DM) is complex and poorly understood. Studying genetic components of intermediate phenotypes, such as endothelial dysfunction and oxidative stress, may aid in identifying novel genetic components for atherosclerosis in diabetic patients.

METHODS

Five polymorphisms forming two haplotype blocks within the GTP cyclohydrolase 1 gene, encoding a rate limiting enzyme in tetrahydrobiopterin synthesis, were studied in the context of flow and nitroglycerin mediated dilation (FMD and NMD), intima-media thickness (IMT), and plasma concentrations of von Willebrand factor (vWF) and malondialdehyde (MDA).

RESULTS

Rs841 was associated with FMD (p = 0.01), while polymorphisms Rs10483639, Rs841, Rs3783641 (which form a single haplotype) were associated with both MDA (p = 0.012, p = 0.0015 and p = 0.003, respectively) and vWF concentrations (p = 0.016, p = 0.03 and p = 0.045, respectively). In addition, polymorphism Rs8007267 was also associated with MDA (p = 0.006). Haplotype analysis confirmed the association of both haplotypes with studied variables.

CONCLUSIONS

Genetic variation of the GCH1 gene is associated with endothelial dysfunction and oxidative stress in T2DM patients.

Inactivation of heparin by cationically modified chitosan

This study was performed to evaluate the ability of N-(2-hydroxypropyl)-3-tri methylammonium chitosan chloride (HTCC), the cationically modified chitosan, to form biologically inactive complexes with unfractionated heparin and thereby blocking its anticoagulant activity. Experiments were carried out in rats in vivo and in vitro using the activated partial thromboplastin time (APTT) and prothrombin time (PT) tests for evaluation of heparin anticoagulant activity. For the first time we have found that HTCC effectively neutralizes anticoagulant action of heparin in rat blood in vitro as well as in rats in vivo. The effect of HTCC on suppression of heparin activity is dose-dependent and its efficacy can be comparable to that of protamine-the only agent used in clinic for heparin neutralization. HTCC administered i.v. alone had no direct effect on any of the coagulation tests used. The potential adverse effects of HTCC were further explored using rat experimental model of acute toxicity. When administered i.p. at high doses (250 and 500 mg/kg body weight), HTCC induced some significant dose-dependent structural abnormalities in the liver. However, when HTCC was administered at low doses, comparable to those used for neutralization of anticoagulant effect of heparin, no histopathological abnormalities in liver were observed.

The current view on biological potency of cationically modified chitosan

Chitosan is biocompatible polymer obtained from chitin, the building component of the crustacean shells. In this paper we make an attempt to review the current state of knowledge on some biological effects of chitosan in comparison with those of cationically modified chitosan, N-(2-hydroxypropyl)-3-trimethylammonium chitosan chloride (HTCC) that was recently synthetized by us by covalent attachment of glycidyltrimethylammonium chloride (GTMAC). Biological effects of HTCC and non-modified polymer are very similar. However, HTCC shows some unique beneficial properties which have not been found in its non-modified counterpart. One such example is that HTCC has the ability to bind heparin at physiological pH. HTCC having the degree of substitution almost 63.6% is easily absorbed within 1 hour after oral administration as found in C57BL/6j mice using FITC-labeled polymer. HTCC is distributed to lung, heart, and kidneys. HTCC stimulates and enhances blood platelet aggregation and decreases erythrocyte deformability (RBC). Moreover, HTCC seems to decrease both plasma total cholesterol level and LDL-cholesterol level in apoE-knockout mice fed with a diet containing HTCC. HTCC possibly down-regulates the HMG-CoAR mRNA level after 24 hour incubation with HepG2 cells in vitro.

Role of angiotensin-(1-7) in gastroprotection against stress-induced ulcerogenesis. The involvement of mas receptor, nitric oxide, prostaglandins, and sensory neuropeptides

Angiotensin-(1-7) [Ang-(1-7)] is a major vasoactive metabolite of angiotensin I (Ang I), both being important components of the renin-angiotensin system (RAS). Ang-(1-7) acting via Mas receptor was documented in kidneys, heart, brain, and gastrointestinal (GI)-tract. We studied the gastroprotective activity of exogenous Ang-(1-7) in rats exposed to water immersion and restraint stress (WRS) without or with A-779 [d-Ala7-Ang-(1-7), an antagonist of Ang-(1-7) Mas receptors], AVE 0991 (5-formyl-4-methoxy-2-phenyl-1[[4-[2-(ethylaminocarbonylsulfonamido)-5-isobutyl-3-thienyl]-phenyl]-methyl]-imidazole), the agonist of Ang-(1-7) receptor, as well as the inhibition of nitric-oxide (NO) synthase, the suppression of cyclo-oxygenase (COX)-1 (indomethacin, SC-560 [5-(4-chloro-phenyl)-1-(4-methoxyphenyl)-3-trifluoromethyl-pyrazole]), the activity COX-2 (rofecoxib), and denervation with capsaicin. The mRNA expression of constitutively expressed nitric-oxide synthase (cNOS), inducible nitric-oxide synthase (iNOS), interleukin (IL)-1β, and tumor necrosis factor (TNF)-α was analyzed by reverse transcription polymerase chain reaction. The WRS lesions were dose-dependently reduced by pretreatment with Ang-(1-7), which also caused an increase in gastric blood flow (GBF) and luminal content of NO. COX-1 and COX-2 inhibitors or L-NNA (N5-[imino(nitroamino)methyl]-L-ornithine) reversed the reduction in lesion number and the rise in GBF evoked by Ang-(1-7). Ang II augmented the WRS lesions, decreased GBF and increased the plasma IL-1β and TNF-α levels. Capsaicin denervation attenuated the reduction of Ang-(1-7)-induced gastric lesions and the rise in GBF; these effects were restored by supplementation with calcitonin gene-related peptide (CGRP). The cNOS mRNA was upregulated while iNOS, IL-1β and TNF-α mRNAs were downregulated in Ang-(1-7)-pretreated rats. We conclude that Ang-(1-7), in contrast to Ang II, which worsened WRS ulcerogenesis, affords potent gastroprotection against WRS ulcerogenesis via an increase in GBF mediated by NO, endogenous prostaglandins, sensory neuropeptides, and anti-inflammatory action involving the inhibition of proinflammatory markers iNOS, IL-1β, and TNF-α.

The influence of angiotensin-(1-7) peptidomimetic (AVE 0991) and nebivolol on angiotensin I metabolism in aorta of apoE-knockout mice

The detrimental role of over activation of renin-angiotensin system (RAS) in atherogenesis is widely recognized. Recently, we have demonstrated that Ang-(1-7) peptidomimetic - AVE0991, as well as known beta-adrenolytic agent nebivolol, exert anti-atherogenic actions in mouse model of atherosclerosis - apoE-knockout mice. Here, using LC-ESI-MS ex vivo system, we tested whether prolonged treatment of apoE-knockout mice by these drugs can influence RAS in aorta of apoE-knockout mice in regard to generation of most active metabolites of Ang I-Ang II and Ang-(1-7). As compared to wild type animals there was increased generation of Ang II in aorta of apoE-knockout mice, while the formation of Ang-(1-7) did not differ between both groups. Either treatment with AVE0991 or nebivolol resulted in significant attenuation of Ang II production in aorta of apoE-knockout mice. In conclusion, for the first time we directly demonstrated that there is increase in ability of aortic tissue to generate Ang II in mouse model of atherosclerosis of apoE knockout mice, and that such effect could be efficiently attenuated either by treatment of nebivolol or Ang-(1-7) peptidomimetic - AVE0991. The exact mechanism(s) responsible for interference of both drugs with RAS require further investigation.

Mechanisms of oxidative stress in human aortic aneurysms--association with clinical risk factors for atherosclerosis and disease severity

Aortic abdominal aneurysms (AAA) are important causes of cardiovascular morbidity and mortality. Oxidative stress may link multiple mechanisms of AAA including vascular inflammation and increased metalloproteinase activity. However, the mechanisms of vascular free radical production remain unknown. Accordingly, we aimed to determine sources and molecular regulation of vascular superoxide (O2(-)) production in human AAA.

METHODS AND RESULTS

AAA segments and matched non-dilated aortic samples were obtained from 40 subjects undergoing AAA repair. MDA levels (determined by HPLC/MS) were greater in plasma of AAA subjects (n=16) than in risk factor matched controls (n=16). Similarly, superoxide production, measured by lucigenin chemiluminescence and dihydroethidium fluorescence, was increased in aneurysmatic segments compared to non-dilated aortic specimens. NADPH oxidases and iNOS are the primary sources of O2(-) in AAA. Xanthine oxidase, mitochondrial oxidases and cyclooxygenase inhibition had minor or no effect. Protein kinase C inhibition had no effect on superoxide production in AAA. NADPH oxidase subunit mRNA levels for p22phox, nox2 and nox5 were significantly increased in AAAs while nox4 mRNA expression was lower. Superoxide production was higher in subjects with increased AAA repair risk Vanzetto score and was significantly associated with smoking, hypercholesterolemia and presence of CAD in AAA cohort. Basal superoxide production and NADPH oxidase activity were correlated to aneurysm size.

CONCLUSIONS

Increased expression and activity of NADPH oxidases are important mechanisms underlying oxidative stress in human aortic abdominal aneurysm. Uncoupled iNOS may link oxidative stress to inflammation in AAA. Oxidative stress is related to aneurysm size and major clinical risk factors in AAA patients.

The effect of AVE 0991, nebivolol and doxycycline on inflammatory mediators in an apoE-knockout mouse model of atherosclerosis

BACKGROUND

The aim of this study was to investigate whether the 3 different substances that can decrease the development of atherosclerosis--nebivolol, AVE 0991 and doxycycline--could at the same time diminish the level of inflammatory indicators interleukin-6 (IL-6), interleukin-12 (IL-12), serum amyloid A (SAA), and monocyte chemotactic protein-1 (MCP-1).

MATERIAL/METHODS

Forty 8-week-old female apoE-knockout mice on the C57BL/6J background were divided into 4 groups and put on chow diet for 4 months. Three experimental groups received the same diet as a control group, mixed with AVE 0991 at a dose 0.58 µmol per kg of body weight per day, nebivolol at a dose 2.0 µmol per kg of body weight per day, and doxycycline at a dose 1.5 mg per kg of body weight per day. At the age of 6 months, the mice were sacrificed.

RESULTS

All inflammatory indicators (MCP-1, IL-6, IL-12 and SAA) were diminished by AVE 0991. There was also a tendency to lower MCP-1, IL-6, IL-12 and SAA levels by nebivolol and doxycycline; however, it did not reach statistical significance.

CONCLUSIONS

Of the 3 presented substances, only AVE 0991 was able to diminish the rise of inflammatory markers. Therefore, drug manipulations in the renin-angiotensin-aldosterone axis seem to be the most promising in the future treatment of atherogenesis.

Influence of atorvastatin on angiotensin I metabolism in resting and TNF-α -activated rat vascular smooth muscle cells

INTRODUCTION

Vascular smooth muscle cells (VSMCs) are essential for maintaining vasculature homeostasis and function. By influence on its growth and activation both proinflammatory cytokines and peptides of the renin-angiotensin system (RAS) are potent regulators of VSMCs. Interestingly, angiotensin (Ang) II and Ang-(1-7) elicit opposite effects on VSMC activation, differentiation and proliferation. It has been suggested that statins, besides anti-inflammatory effects, may also modulate VSMC activation by their influence on the RAS.

METHODS

The effect of atorvastatin on Ang I metabolism in a culture of explanted rat VSMCs was examined by liquid chromatography-mass spectrometry (LC-MS); expression of mRNA of the main RAS enzymes in VSMC was assessed by real-time polymerase chain reaction (PCR).

RESULTS

In VSMC culture Ang-(1-7) was identified as a major product of Ang I metabolism. In this setting, TNF-α (1 ng/ml) caused a decrease in the conversion of Ang I to Ang-(1-7). This effect was accompanied by a decrease of mRNA expression of neutral endopeptidase (NEP) and angiotensin converting enzyme 2 (ACE2) and increase of mRNA of ACE. Interestingly, atorvastatin (3 μM) attenuated the effects of TNF-α on Ang-(1-7) production as well as reversed the influence of TNF-α on ACE and ACE2 expression.

CONCLUSIONS

Enhancement by atorvastatin of the ACE2/Ang-(1-7) axis in VSMCs could represent a new and beneficial mechanism on cardiovascular action of this widely used drug.

Vasodilatory effect and endothelial integrity in papaverine- and milrinone-treated human radial arteries

Prevention of the vasospasm is an important aspect of coronary artery bypass grafting (CABG) with the use of radial artery (RA) as the conduit. We compared the effect of two phosphodiesterase inhibitors papaverine and milrinone on vasodilation and endothelial integrity of human RA segments harvested from 20 CABG patients. Vasodilatory effect of the drugs were assessed by organ bath technique in RA rings precontracted with KCl and phenylephrine. Endothelial integrity was evaluated by CD34 immunofluorescence in frozen sections. Vasorelaxation induced by papaverine was significantly greater as compared to that induced by milrinone (90.47% ± 10.16% vs. 78.98% ± 19.56%, p<0.05). Similarly, pretreament with papaverine more strongly inhibited the contractile response of RA rings to KCl (6.0 ± 8.0 mN vs. 26.7 ± 21.5 mN, p<0.001). Papaverine was also superior to milrinone in the preservation of endothelial integrity (75.3% ± 12.9% vs. 51.8% ± 18.0%, p<0.02). In conclusion, papaverine seems to be more suitable than milrinone for prevention of vasospasm in radial artery conduits used for CABG.

Assessment of angiotensin I metabolism in the human placenta using an LC/MS method

The local renin-angiotensin system (RAS) in the placenta plays a very important role in placental development. It is well known that during normal pregnancy most of the circulating and local RAS components are over-expressed and any disruption of this new balance may cause pregnancy complications. The aim of this study was to assess the metabolism of Ang I in placentas from normal pregnancy, in an ex vivo model, using an LC/MS method. The obtained results suggest that placental tissue is able to produce many angiotensin peptides but the main metabolite is Ang-(1-7).

Local inflammation is associated with aortic thrombus formation in abdominal aortic aneurysms. Relationship to clinical risk factors

Intraluminal thrombus formation in aortic abdominal aneurysms (AAA) is associated with adverse clinical prognosis. Interplay between coagulation and inflammation, characterised by leukocyte infiltration and cytokine production, has been implicated in AAA thrombus formation. We studied leukocyte (CD45+) content by flow cytometry in AAA thrombi from 27 patients undergoing surgical repair. Luminal parts of thrombi were leukocyte-rich, while abluminal segments showed low leukocyte content. CD66b+ granulocytes were the most prevalent, but their content was similar to blood. Monocytes (CD14+) and T cells (CD3+) were also abundant, while content of B lymphocytes (CD19+) and NK cells (CD56+CD16+) were low. Thrombi showed comparable content of CD14highCD16- monocytes and lower CD14highCD16+ and CD14dimCD16+, than blood. Monocytes were activated with high CD11b, CD11c and HLA-DR expression. Total T cell content was decreased in AAA thrombus compared to peripheral blood but CD8 and CD3+CD4-CD8- (double negative T cell) contents were increased in thrombi. CD4+ cells were lower but highly activated (high CD69, CD25 and HLA-DR). No differences in T regulatory (CD4+CD25+FoxP3+) cell or pro-atherogenic CD4+CD28null lymphocyte content were observed between thrombi and blood. Thrombus T cells expressed high levels of CCR5 receptor for chemokine RANTES, commonly released from activated platelets. Leukocyte or T cell content in thrombi was not correlated with aneurysm size. However, CD3+ content was significantly associated with smoking in multivariate analysis taking into account major risk factors for atherosclerosis. In conclusion, intraluminal AAA thrombi are highly inflamed, predominantly with granulocytes, CD14highCD16- monocytes and activated T lymphocytes. Smoking is associated with T cell infiltration in AAA intraluminal thrombi.

Beneficial effect of amantadine on postoperative pain reduction and consumption of morphine in patients subjected to elective spine surgery

OBJECTIVE

To analyze the effect of coadministration of morphine and amantadine on postoperative pain reduction and morphine consumption in patients after elective spine surgery.

METHODS

In double-blinded study, 60 patients (ASA physical status I-II) were randomized into two groups. Group A was given oral amantadine 50 or 100 mg 1 hour before surgery and 8, 20, 32 hours after operation. Group P received placebo at identical times. Pain was assessed using numerical rating scale before first administration of morphine and in 2, 3, 4, 6, 24, and 48 hours after operation. The amounts of morphine consumed were recorded up to 48 hours after surgery. Blood samples were taken twice in 2 hours after surgery and plasma levels of morphine and its main metabolites were measured.

RESULTS

As compared with placebo, amantadine significantly reduced intra-operative Fentanyl use and sensation of postoperative pain. Up to 48 hours after operation, the cumulative consumption of morphine was 25% lower in the amantadine group. Moreover, intensity of nausea and vomiting tended to be lower in A group. Starting from 12th hour after surgery, the level of postoperative sedation was lower in patients who received amantadine, as compared with placebo group. No significant differences in plasma levels of morphine ant its metabolites were observed between A and P groups.

CONCLUSIONS

Pre- and postoperative administration of amantadine significantly reduced fentanyl use during operation, as well as reduced the postoperative pain and decreased morphine consumption in young patients undergoing orthopedic surgery.

Angiotensin-(1-7) receptor Mas agonist ameliorates progress of atherosclerosis in apoE-knockout mice

Our interest focused on an open question whether AT-(1-7), nonpeptide receptor agonist: AVE 0991, is able to ameliorate atherosclerosis. We used an apolipoprotein E (apoE) - knockout mice model of atherosclerosis. Experimental groups received the same diet as control, mixed with: AVE 0991 at a dose of 0.58 μmol/kg b.w./day, perindopril at a dose of 0.4 mg/kg b.w./day or with tiorphan at a dose of 2.5 mg/kg b.w./day. A-779 [(D-alanine)-angiotensin (1-7)] was given at a dose of 3.3 mg/kg b.w., 3 times a week i.p. Measured by "en face" method, the percentage of occupied by Sudan IV-stained surfaces were as follows: 14.2±1.9 % in control group, whereas in AVE 0991-treated as well as in perindopril-treated groups percentages were statistically significantly lower. In tiorphan group there was no change comparing to control group, whereas in A-779 group percentage was statistically significantly higher. "Cross-section" of aortic roots revealed also the difference in atherosclerotic lesions. The mean surfaces, occupied by oil red O-stained changes were: 91.213±8.123 μm(2) in control group, while in AVE 0991-treated as well as in perindopril-treated groups lesions were statistically significantly lower. In tiorphan group there was no change; however, in A-779 group lesions were statistically significantly higher. Measured by real time RT-PCR relative p22phox (submit of NADPH oxidase) expression was significantly decreased in AVE 0991-treated mice. As revealed by flow cytometry, the expression of co-stimulatory molecules: CD86, CD80 and CD40 on both dendritic cells (CD11c+) and macrophages (F4/80+) was reduced in AVE 0991-treated group, which correlated with decreased expression of CD69 activation marker on CD4+T cells. In our report we showed the beneficial effect of AVE 0991 on atherogenesis in gene-targeted mice.

[Endothelial dysfunction related to oxidative stress and inflammation in perivascular adipose tissue]

Endothelial dysfunction plays an important role in the pathogenesis of many common diseases, like atherosclerosis and hypertension. The key role of the interaction between oxidative stress and inflammation in causal mechanisms of these diseases is widely accepted. Until recently, perivascular adipose tissue was not taken into account while looking at mechanisms of these disorders. However, it has recently been demonstrated that most processes involved in endothelial dysfunction development are taking place in this tissue. Adipocytes are an important source of free radicals and pro-inflammatory cytokines. These molecules lead to further enhancement of oxidative stress, through uncoupling of endothelial nitric oxide synthase (eNOS) and production of peroxynitrite radical instead of nitric oxide which further disrupts eNOS function. In addition, macrophages and T lymphocytes infiltrate adipose tissue as a result of chemotactic proteins release, upon oxidative stress activation, which further enhances inflammation. Thus, the chronic inflammation, which develops in this compartment of adipose tissue in patients with obesity, is the first step in the development of atherosclerotic plaque or hypertension. That is why comprehensive understanding of ongoing processes within perivascular adipocytes is so important.