Hydroxychloroquine reverses the prothrombotic state in a mouse model of antiphospholipid syndrome: Role of reduced inflammation and endothelial dysfunction

Antiphospholipid antibodies (aPL) promote endothelial dysfunction, inflammation and procoagulant state. We investigated the effect of hydroxychloroquine (HCQ) on prothrombotic state and endothelial function in mice and in human aortic endothelial cells (HAEC). Human aPL were injected to C57BL/6 mice treated or not with HCQ. Vascular endothelial function and eNOS were assessed in isolated mesenteric arteries. Thrombosis was assessed both in vitro by measuring thrombin generation time (TGT) and tissue factor (TF) expression and in vivo by the measurement of the time to occlusion in carotid and the total thrombosis area in mesenteric arteries. TGT, TF, and VCAM1 expression were evaluated in HAEC. aPL increased VCAM-1 expression and reduced endothelium dependent relaxation to acetylcholine. In parallel, aPL shortened the time to occlusion and extended thrombus area in mice. This was associated with an overexpression of TF and an increased TGT in mice and in HAEC. HCQ reduced clot formation as well as TGT, and improved endothelial-dependent relaxations. Finally, HCQ increased the p-eNOS/eNOS ratio. This study provides new evidence that HCQ improves procoagulant status and vascular function in APS by modulating eNOS, leading to an improvement in the production of NO.

Unexpected role of the human cytomegalovirus contribute to essential hypertension in the Kazakh Chinese population of Xinjiang

Human cytomegalovirus (HCMV) infection, chronic inflammation and oxidative stress, the renin-angiotensin system (RAS), endothelial function, and DNA methylation play roles in the pathogenesis of essential hypertension (EH); however, the mechanism by which HCMV predisposes patients to hypertension remain unclear. Our group previously demonstrated an association between EH and HCMV infection in Kazakh Chinese. Here, we investigated the relationship between HCMV infection and other clinicopathological features in 720 Kazakh individuals with or without hypertension (n=360 each; age: 18-80). Multiple linear and logistic regression analyses were used to determine the associations between HCMV infection, clinical characteristics, and EH. Notably, patients with EH, particularly those with HCMV infection, exhibited a marked increase in tumor necrosis factor-α (TNF-α) and 8-hydroxy-2-deoxyguanosine (8-OHDG) levels, but a decrease in endothelial nitric oxide synthase (eNOS) and renin levels. Similarly, elevated TNF-α and 8-OHDG levels were independent predictors of increased HCMV antibody titers, whereas eNOS and renin were negatively correlated with the latter. Moreover, serum angiotensin-converting enzyme (sACE, ACE) methylation was increased, whereas 11-β hydroxysteroid dehydrogenase 2 (HSD11β2; HSD3B2) methylation was decreased in patients with EH who were also infected with HCMV. A positive correlation between HSD3B2 methylation and HCMV IgG titer and blood pressure was additionally observed, whereas angiotensin-converting enzyme (ACE) methylation was inversely correlated with blood pressure. Collectively, these data indicate that HCMV may contribute to EH development in the Kazakh Chinese by increasing TNF-α and 8-OHDG levels, suppressing eNOS and renin, and manipulating HSD3B2 and ACE methylation.

[Afalaza in the management of patients with chronic pelvic pain syndrome]

INTRODUCTION

Currently, chronic pelvic pain syndrome (CPPS) is one of the most prevalent urological diseases, but due to the multifactorial nature of the disease and the lack of consensus on its pathogenesis, the issue of adequate therapy remains open. Since the vascular factor plays the major role in the pathogenesis of CPPS, we hypothesized that this category of patients has microcirculatory disturbances of the prostate.

AIM

Detection of microcirculatory disturbances of the prostate, their correction, and evaluation of the effect on the course of CPPS.

MATERIALS AND METHODS

The study comprised 60 healthy, sexually active men with clinical manifestations of CPPS lasting from 6 months to 5 years. After a comprehensive examination, all patients received Afalaza 2 tablets twice daily for 16 weeks. At the end of week 16, patients were re-examined.

RESULTS

In patients with CPPS, therapy with Afalaza resulted in a significant improvement in microcirculation in the prostate thus leading to the reduction of the severity of disease manifestations.

Inflammatory monocytes determine endothelial nitric-oxide synthase uncoupling and nitro-oxidative stress induced by angiotensin II

Endothelial nitric-oxide synthase (eNOS) uncoupling and increased inducible NOS (iNOS) activity amplify vascular oxidative stress. The role of inflammatory myelomonocytic cells as mediators of these processes and their impact on tetrahydrobiopterin availability and function have not yet been defined. Angiotensin II (ATII, 1 mg/kg/day for 7 days) increased Ly6C(high) and CD11b(+)/iNOS(high) leukocytes and up-regulated levels of eNOS glutathionylation in aortas of C57BL/6 mice. Vascular iNOS-dependent NO formation was increased, whereas eNOS-dependent NO formation was decreased in aortas of ATII-infused mice as assessed by electron paramagnetic resonance (EPR) spectroscopy. Diphtheria toxin-mediated ablation of lysozyme M-positive (LysM(+)) monocytes in ATII-infused LysM(iDTR) transgenic mice prevented eNOS glutathionylation and eNOS-derived N(ω)-nitro-L-arginine methyl ester-sensitive superoxide formation in the endothelial layer. ATII increased vascular guanosine triphosphate cyclohydrolase I expression and biopterin synthesis in parallel, which was reduced in monocyte-depleted LysM(iDTR) mice. Vascular tetrahydrobiopterin was increased by ATII infusion but was even higher in monocyte-depleted ATII-infused mice, which was paralleled by a strong up-regulation of dihydrofolate reductase expression. EPR spectroscopy revealed that both vascular iNOS- and eNOS-dependent NO formation were normalized in ATII-infused mice following monocyte depletion. Additionally, deletion as well as pharmacologic inhibition of iNOS prevented ATII-induced endothelial dysfunction. In summary, ATII induces an inflammatory cell-dependent increase of iNOS, guanosine triphosphate cyclohydrolase I, tetrahydrobiopterin, NO formation, and nitro-oxidative stress as well as eNOS uncoupling in the vessel wall, which can be prevented by ablation of LysM(+) monocytes.

Perthamide C inhibits eNOS and iNOS expression and has immunomodulating activity in vivo

Here we have characterized perthamide C, a cyclopeptide from a Solomon Lithistid sponge Theonella swinhoei, which displays an anti-inflammatory/immunomodulatory activity. The study has been performed using the carragenan-induced mouse paw edema that displays an early (0–6 h) and a late phase (24–96 h). Perthamide C significantly inhibits neutrophils infiltration in tissue both in the early and late phases. This effect was coupled to a reduced expression of the endothelial nitric oxide synthase (eNOS) in the early phase while cyclooxygenase-1 and 2 (COX-1, COX-2), and inducible NOS (iNOS) expression were unaffected. In the late phase perthamide C reduced expression of both NOS isoforms without affecting COXs expression. This peculiar selectivity toward the two enzymes deputed to produce NO lead us to investigate on a possible action of perthamide C on lymphocytes infiltration and activation. We found that perthamide C inhibited the proliferation of peripheral lymphocytes, and that this effect was secondary to its metabolic activation in vivo. Indeed, in vitro perthamide C did not inhibit proliferation as opposite to its metabolite perthamide H.

In conclusion, perthamide C selectively interferes with NO generation triggered by either eNOS or iNOS without affecting either COX-1 or COX-2. This in turn leads to modulation of the inflammatory response through a reduction of vascular permeability, neutrophil infiltration as well as lymphocyte proliferation.

[Effects of mexidol and sulodexide on the level of specific markers of endothelial dysfunction in animals with experimental diabetes mellitus]

Streptozotocin-induced diabetes leads to the development of endothelial dysfunction, as evidenced by decreased expression of endothelial nitric oxide synthase (eNOS) and increased expression of endothelin-1 as specific markers of endothelial disorders. All test substances showed endotelioprotective activity by increasing the concentration of eNOS and reducing the level of endothelin-1. With respect to the degree of impact on the eNOS and endothelin-1 levels, the compounds studied can be rated as follows: sulodexide > meksidol.

TRAF1/C5, eNOS, C1q, but not STAT4 and PTPN22 gene polymorphisms are associated with genetic susceptibility to systemic lupus erythematosus in Turkey

A significant source of variability in the literature on systemic lupus erythematosus (SLE) susceptibility genes has been the inability to replicate genetic findings across different racial or ethnic groups. We investigated whether a single nucleotide polymorphism (SNP) of the STAT4 (rs7574865), PTPN22 (rs2476601), TRAF1/C5 (rs10818488), and C1q (rs292001) genes as well as the 27-bp VNTR polymorphism on intron 4 of eNOS, previously associated with SLE in other populations, are also associated with SLE risk in Turkey. A group of 158 SLE patients and 155 healthy controls were included in this study. A genetic association of the TRAF1/C5, C1q, and eNOS gene polymorphism, but not of STAT4 and PTPN22, was found to confer a degree of risk for SLE. These data highlight the importance of comparative studies in different populations to confirm the previously detected genetic associations.

Estradiol increases angiotensin II type 1 receptor in hearts of ovariectomized rats

We tested the hypothesis that 17beta-estradiol (E(2)) has dual effects on the heart, increasing levels of proteins thought to have beneficial cardiovascular effects (e.g. endothelial nitric oxide (NO) synthase (eNOS)) as well as those thought to have detrimental cardiovascular effects (e.g. type 1 angiotensin II (AngII) receptor (AT(1)R)). Ovariectomized Wistar rats consuming a high-sodium diet received one of four treatments (n=7 per group): group 1, placebo pellets; group 2, E(2) (0 x 5 mg/pellet, 21-day release); group 3, NOS inhibitor, N(omega)-nitro-L-arginine-methyl-ester (L-NAME; 40 mg/kg per day for 14 days) plus Ang II (0 x 225 mg/kg per day on days 11-14); group 4, E(2) plus L-NAME/Ang II. E(2) increased cardiac levels of estrogen receptors ESR1 and ESR2, an ESR-associated membrane protein caveolin-3, eNOS, and phosphorylated (p)eNOS, thus, exerting potentially beneficial cardiovascular effects on NO. However, E(2) also increased cardiac levels of proteins associated with cardiovascular injury and inflammation including, AT(1)R, protein kinase C delta (PRKCD), phosphorylated PRKC, and phosphorylated extracellular signal regulated kinase (pMAPK)3/1, plasminogen activator inhibitor-1 (PAI-1), osteopontin and ED-1, a monocyte/macrophage-specific protein. E(2) treatment led to similar protein changes in the hearts of L-NAME/Ang II-treated rats except that the increase in peNOS was prevented, and L-NAME/Ang II and E(2) had additive effects in increasing cardiac PRKCD and PAI-1. Thus, the highest levels of cardiac PAI-1 and PRKCD occurred in L-NAME/Ang II-treated rats receiving E(2). In summary, E(2) treatment increased cardiac expression of AT(1)R as well as the expression of pro-inflammatory and prothrombotic factors.

Anxiolytic and antidepressant characteristics of impaza

Antibodies to endothelial NO synthase in ultralow doses exhibited anxiolytic and antidepressant effects and their efficiency after single and course treatment is not inferior to that of amitriptyline and diazepam. The psychotropic activity of ultralow-dose antibodies to endothelial NO-synthase is presumably one of important mechanisms of their efficiency in the treatment of erectile dysfunction.

[Prevention of erectile dysfunction in patients with metabolic syndrome]

The aim of the study was to test efficacy of erectile dysfunction prevention in patients with metabolic syndrome by correction of metabolic disorders and stimulation of endothelial NO-synthetase. In case of the above correction and stimulation combination, the risk of erectile dysfunction went up significantly compared to placebo group and patients with correction of metabolic disorders alone.

Transgenic expression of human C-reactive protein suppresses endothelial nitric oxide synthase expression and bioactivity after vascular injury

C-reactive protein (CRP) is a risk marker and a potential modulator of vascular disease. Whether CRP modulates nitric oxide (NO) synthase (NOS) activity and NO metabolism remains unclear. We studied the effect of CRP on NO metabolism in transgenic mice that express human CRP (CRPtg). CRPtg and wild-type mice were subjected to controlled femoral artery wire injury. CRP serum levels at baseline and 6 and 24 h after injury were 12.4 +/- 9, 18.6 +/- 6.9, and 58.4 +/- 13 mg/l, respectively, in CRPtg mice but were undetectable at all time points in wild-type mice. Endothelial NOS protein and mRNA expression were significantly suppressed in the injured arteries of CRPtg mice (n = 5, P < 0.05). A similar reduction in eNOS expression was observed in the distant lung and heart. NO release after injury was significantly lower in CRPtg mice, as measured by nitrate and nitrite breakdown products, with a concomitant suppression of cGMP NO signaling after injury. Endothelial NOS and NO expression after vascular injury are locally and systemically suppressed in mice that express human CRP. These in vivo observations support the hypothesis that CRP modulates NO metabolism and may have implications regarding the mechanisms by which CRP modulates vascular disease.

Regulation of endothelial nitric-oxide synthase activity through phosphorylation in response to epoxyeicosatrienoic acids

Endothelial nitric oxide synthase (eNOS) is a key enzyme in NO-mediated cardiovascular homeostasis and its activity is modulated by a variety of hormonal and mechanical stimuli via phosphorylation modification. Our previous study has demonstrated that epoxyeicosatrienoic acids (EETs), the cytochrome P450 (CYP)-dependent metabolites of arachidonic acid, could robustly up-regulate eNOS expression. However, the molecular mechanism underlying the effects of EETs on eNOS remains elusive. Particularly, whether and how EETs affect eNOS phosphorylation is unknown. In the present study, we investigated the effects of EETs on eNOS phosphorylation with cultured bovine aortic endothelial cells (BAECs). BAECs were either treated with exogenous EETs or infected with recombinant adeno-associated virus (rAAV) carrying CYP2C11-CYPOR, CYP102 F87V mutant and CYP2J2, respectively, to increase endogenous EETs. Both addition of EETs and CYP epoxygenase transfection markedly increased eNOS phosphorylation at its Ser1179 and Thr497 residues. Inhibition of phosphatidylinositol 3-kinase (PI3K) with LY294002 prevented EETs-induced increases of eNOS-Ser(P)1179 but had no effect on the phosphorylation status of Thr497. However, inhibitors of protein kinase B (Akt), mitogen-activated protein kinase (MAPK) and MAPK kinase could block phosphorylation of eNOS at both sites. Inhibition of these kinases also attenuated the up-regulation of eNOS expression by EETs. Finally, administration of viral CYP epoxygenases expression vectors into rats enhanced eNOS phosphorylation and function in vivo. Thus, in addition to up-regulating eNOS expression, EETs also augment eNOS function by enhancing eNOS phosphorylation. EETs-induced up-regulation of eNOS phosphorylation and expression appears to involve in both PI3K/Akt and MAPK pathways.

Oxygen alters caveolin-1 and nitric oxide synthase-3 functions in ovine fetal and neonatal lung microvascular endothelial cells

We determined the effect of oxygen [∼100 Torr (normoxia) and ∼30–40 Torr (hypoxia)] on functions of endothelial nitric oxide (NO) synthase (NOS-3) and its negative regulator caveolin-1 in ovine fetal and neonatal lung microvascular endothelial cells (MVECs). Fetal NOS-3 activity, measured as NO production with 0.5–0.9 μM 4-amino-5-methylamino-2,7-difluorofluorescein, was decreased in hypoxia by 14.4% ( P < 0.01), inhibitable by the NOS inhibitor N-nitro-l-arginine, and dependent on extracellular arginine. Caveolar function, assessed as FITC-BSA (160 μg/ml) endocytosis, was decreased in hypoxia by 13.5% in fetal and 22.8% in neonatal MVECs ( P < 0.01). NOS-3 and caveolin-1 were physically associated, as demonstrated by coimmunoprecipitation and colocalization, and functionally associated, as shown by cross-activation of endocytosis, by their specific antibodies and activation of NOS by albumin. Caveolin peptide, containing the sequence for the PKC phosphorylation site of caveolin, and caveolin antiserum against the site increased NO production and endocytosis by 12.3% ( P < 0.05) and 16% ( P < 0.05), respectively, in normoxia and increased endocytosis by 25% ( P < 0.001) in hypoxia. PMA decreased NO production in normoxia and hypoxia by 19.32% ( P < 0.001) and 11.8% ( P < 0.001) and decreased endocytosis in normoxia by 20.35% ( P < 0.001). PKC kinase activity was oxygen sensitive, and threonine phosphorylation was enhanced in hypoxia. Pertussis toxin increased caveolar and NOS functions. These data support our hypothesis that increased Po2at birth promotes dissociation of caveolin-1 and NOS-3, with an increase in their activities, and that PKC and an oxygen-sensitive cell surface G protein-coupled receptor regulate caveolin-1 and NOS-3 interactions in fetal and neonatal lung MVECs.

Caveolin-3 and eNOS colocalize and interact in ciliated airway epithelial cells in the rat

In ciliated airway epithelial cells endothelial nitric oxide synthase as well as several other membrane bound proteins are located in the apical cell pole. To date, mechanisms that serve to target and to keep these proteins in this region are unknown. Endothelial nitric oxide synthase is known to target to caveolae by interaction with caveolin-1 or caveolin-3. Since caveolin-1 is found only in a subpopulation of ciliated cells at the basolateral cell membrane, we examined if caveolin-3 could be responsible for the apical localization of endothelial nitric oxide synthase in ciliated cells. We used real-time RT-PCR, laser-assisted microdissection, Western blotting and double-labeling immunohistochemistry to examine the presence of caveolin-3 in the airway epithelium of the rat. Indeed, we found caveolin-3-mRNA as well as protein in ciliated cells throughout the trachea and the bronchial tree. Caveolin-3-immunoreactivity was confined to the apical region and was colocalized with endothelial nitric oxide synthase and the high affinity choline transporter in a compartment distinct from the plasma membrane at the light microscopic level. No caveolae were found in the apical plasma membrane of ciliated cells but a tubulovesicular network was present in the apical region that reached up to the basal bodies of the cilia and was in close contact with mitochondria. Co-immunoprecipitation of caveolin-3 with endothelial nitric oxide synthase verified that both proteins interact in airway ciliated cells. These findings indicate that caveolin-3 is responsible to keep endothelial nitric oxide synthase in a membrane compartment in the apical region of ciliated cells.

Vein Graft Harvesting Induces Inflammation and Impairs Vessel Reactivity

BACKGROUND

Saphenous veins are often used for coronary artery bypass grafting (CABG), but loss of patency is a problem. The surgical procedure may contribute to graft injury. Our aim was to study the impact of surgical handling of saphenous veins on graft inflammation and vascular function.

METHODS

Biopsy samples of saphenous veins were taken from 9 patients undergoing elective CABG at the start of vein harvesting (open technique) and after the last proximal anastomosis was sutured. Messenger RNA was extracted and amplified with semiquantitative reverse transcription polymerase chain reaction. Gene expression of proinflammatory cytokines (tumor necrosis factor-alpha, interleukin-1beta), leukocyte adhesion molecules (E-selectin, intercellular adhesion molecule-1), and vasoactive substances (endothelin-1, inducible and endothelial nitric oxide synthase) was investigated. Translocation of nuclear factor-kappaB (NFkappaB) was evaluated with electrophoretic mobility shift assay. Immunostaining for von Willebrand factor was performed to evaluate loss of endothelium, and in vitro vein reactivity to phenylephrine and endothelin-1 was studied.

RESULTS

Gene expression of cytokines and leukocyte adhesion molecules increased after graft harvesting and storage, whereas vasoactive substances did not change. Nuclear translocation of NFkappaB occurred after surgical handling, concurrent with partial loss of endothelium and impaired contractile function.

CONCLUSIONS

Standard surgical handling of vein grafts induces NFkappaB-driven inflammation in the vessel wall and impairs vascular function. This may potentially contribute to both early and late graft occlusion.

Bimodal effect of nitric oxide in the enzymatic activity of indoleamine 2,3-dioxygenase in human monocytic cells

Indoleamine 2,3-dioxygenase (IDO) is an enzyme that depletes l-tryptophan, which provokes a decreased T cell response. This enzyme is expressed in human placenta, and can be also induced in many cell types such as monocytes, where endothelial (eNOS) and inducible (iNOS) nitric oxide synthases are also expressed. Previous studies have shown that nitric oxide (NO) inhibits IDO activity, which could cause a suppression of the biological function of IDO when both enzymes are coexpressed. As NO can exert different effects depending on several factors such as its concentration, we studied the effect of low concentrations of NO in the IDO activity in the U-937 and THP-1 monocytic cell lines. Results demonstrated that NO caused a bimodal effect in IDO function in IFN-gamma-stimulated monocytic cells: while high micromolar concentrations of the NO donors SIN-1 and DETA-NO decreased IDO activity, low micromolar concentrations of these NO donors increased IDO activity. Related to this, the NOS inhibitors L-NMMA and aminoguanidine, and the calmodulin antagonist W7 also decreased IDO activity. The effect of NO in IDO activity was not through cGMP production. Immunoprecipitation analysis showed a nitration of the IDO protein in unstimulated and stimulated U-937 and THP-1 cells. However, in monocyte-derived macrophages, with a higher NO production, aminoguanidine increased IDO activity, but the NOS substrate arginine decreased IDO activity. Considering the role of IDO in suppression, these results suggest a function in tolerance of the NOS enzymes depending on the NO production.

Endothelial nitric oxide synthase/soluble guanylate cyclase system in human nasal polyps

The aim of our study was to analyze the level of expression of the endothelial nitric oxide synthase (eNOS)/soluble guanylate cyclase (sGC) system in nasal polyps and control nasal mucosae. The study was performed in polyps from 15 patients and nasal mucosae from 11 subjects operated on the nasal septum (control group). The expression of endothelial nitric oxide synthase (eNOS) and soluble guanylate cyclase (sGC) was determined in nasal mucosae. Western blot analysis demonstrated that eNOS protein was overexpressed in the nasal polyps with respect to control nasal mucosae. Immunohistochemistry also demonstrated that the vascular endothelium of nasal polyps contained higher amounts of eNOS protein than control nasal mucosae. Moreover, the beta(1) subunit of sGC was also overexpressed in the nasal polyps, which was associated with an increased content of cyclic GMP in the nasal polyps with respect to nasal control mucosae. In human nasal polyposis, there is an overexpression of the eNOS/sGC system. Further studies are needed to assess whether this overexpression is involved in the genesis of nasal polyposis.