The effect of TNF-α inhibitor treatment on microRNAs and endothelial function in collagen induced arthritis.

Chronic inflammation causes dysregulated expression of microRNAs. Aberrant microRNA expression is associated with endothelial dysfunction. In this study we determined whether TNF-α inhibition impacted the expression of miRNA-146a-5p and miRNA-155-5p, and whether changes in the expression of these miRNAs were related to inflammation-induced changes in endothelial function in collagen-induced arthritis (CIA). Sixty-four Sprague-Dawley rats were divided into control (n = 24), CIA (n = 24) and CIA+etanercept (n = 16) groups. CIA and CIA+etanercept groups were immunized with bovine type-II collagen, emulsified in incomplete Freund's adjuvant. Upon signs of arthritis, the CIA+etanercept group received 10mg/kg of etanercept intraperitoneally, every three days. After six weeks of treatment, mesenteric artery vascular reactivity was assessed using wire-myography. Serum concentrations of TNF-α, C-reactive protein, interleukin-6, vascular adhesion molecule-1 (VCAM-1) and pentraxin-3 (PTX-3) were measured by ELISA. Relative expression of circulating miRNA-146a-5p and miRNA-155-5p were determined using RT-qPCR. Compared to controls, circulating miRNA-155-5p, VCAM-1 and PTX-3 concentrations were increased, and vessel relaxation was impaired in the CIA (all p<0.05), but not in the CIA+etanercept (all p<0.05) groups. The CIA group had greater miRNA-146a-5p expression compared to the CIA+etanercept group (p = 0.005). Independent of blood pressure, miRNA-146a-5p expression was associated with increased PTX-3 concentrations (p = 0.03), while miRNA-155-5p expression was associated with impaired vessel relaxation (p = 0.01). In conclusion, blocking circulating TNF-α impacted systemic inflammation-induced increased expression of miRNA-146a-5p and miRNA-155-5p, which were associated with endothelial inflammation and impaired endothelial dependent vasorelaxation, respectively.

C1q/tumor necrosis factor-related protein-3 improves microvascular endothelial function in diabetes through the AMPK/eNOS/NO· signaling pathway.

The repair of vascular endothelial cell dysfunction is an encouraging approach for the treatment of vascular complications associated with diabetes. It has been demonstrated that members of C1q/tumor necrosis factor-related protein (CTRP) family may improve endothelial function. Nevertheless, the protective properties of CTRPs in diabetic microvascular complications continue to be mostly unknown. Here, we demonstrate that the C1q-like globular domain of CTRP3, CTRP5, and CTRP9 (gCTRP3, 5, 9) exerted a vasorelaxant effect on the microvasculature, of which gCTRP3 was the most powerful one. In a murine model of type 2 diabetes mellitus, serum gCTRP3 level and endothelial function decreased markedly compared with controls. Two weeks of gCTRP3 treatment (0.5 µg/g/d) enhanced endothelium-dependent relaxation in microvessels, increased nitric oxide (NO·) production, and reduced retinal vascular leakage. In addition, Western blotting in human retinal microvascular endothelial cells indicated that gCTRP3 triggered AMP-activated protein kinase-α (AMPKα), hence increasing the endothelial NO synthase (eNOS) level and NO· production. In addition, incubation with gCTRP3 in vitro ameliorated the endothelial dysfunction induced by high glucose in the branch of the mesenteric artery. Blockade of either eNOS or AMPKα completely abolished the effects of gCTRP3 described above. Taken together, we demonstrate for the first time that gCTRP3 improves impaired vasodilatation of microvasculature in diabetes by ameliorating endothelial cell function through the AMPK/eNOS/NO· signaling pathway. This finding may suggest an effective intervention against diabetes-associated microvascular complications.

Osteoprotegerin regulates vascular function through syndecan-1 and NADPH oxidase-derived reactive oxygen species.

Osteogenic factors, such as osteoprotegerin (OPG), are protective against vascular calcification. However, OPG is also positively associated with cardiovascular damage, particularly in pulmonary hypertension, possibly through processes beyond effects on calcification. In the present study, we focused on calcification-independent vascular effects of OPG through activation of syndecan-1 and NADPH oxidases (Noxs) 1 and 4. Isolated resistance arteries from Wistar-Kyoto (WKY) rats, exposed to exogenous OPG, studied by myography exhibited endothelial and smooth muscle dysfunction. OPG decreased nitric oxide (NO) production, eNOS activation and increased reactive oxygen species (ROS) production in endothelial cells. In VSMCs, OPG increased ROS production, H2O2/peroxynitrite levels and activation of Rho kinase and myosin light chain. OPG vascular and redox effects were also inhibited by the syndecan-1 inhibitor synstatin (SSNT). Additionally, heparinase and chondroitinase abolished OPG effects on VSMCs-ROS production, confirming syndecan-1 as OPG molecular partner and suggesting that OPG binds to heparan/chondroitin sulphate chains of syndecan-1. OPG-induced ROS production was abrogated by NoxA1ds (Nox1 inhibitor) and GKT137831 (dual Nox1/Nox4 inhibitor). Tempol (SOD mimetic) inhibited vascular dysfunction induced by OPG. In addition, we studied arteries from Nox1 and Nox4 knockout (KO) mice. Nox1 and Nox4 KO abrogated OPG-induced vascular dysfunction. Vascular dysfunction elicited by OPG is mediated by a complex signalling cascade involving syndecan-1, Nox1 and Nox4. Our data identify novel molecular mechanisms beyond calcification for OPG, which may underlie vascular injurious effects of osteogenic factors in conditions such as hypertension and/or diabetes.

Trehalose, a natural disaccharide, reduces stroke occurrence in the stroke-prone spontaneously hypertensive rat.

Cerebrovascular disease, a frequent complication of hypertension, is a major public health issue for which novel therapeutic and preventive approaches are needed. Autophagy activation is emerging as a potential therapeutic and preventive strategy toward stroke. Among usual activators of autophagy, the natural disaccharide trehalose (TRE) has been reported to be beneficial in preclinical models of neurodegenerative diseases, atherosclerosis and myocardial infarction. In this study, we tested for the first time the effects of TRE in the stroke-prone spontaneously hypertensive rat (SHRSP) fed with a high-salt stroke permissive diet (JD). We found that TRE reduced stroke occurrence and renal damage in high salt-fed SHRSP. TRE was also able to decrease systolic blood pressure. Through ex-vivo studies, we assessed the beneficial effect of TRE on the vascular function of high salt-fed SHRSP. At the molecular level, TRE restored brain autophagy and reduced mitochondrial mass, along with the improvement of mitochondrial function. The beneficial effects of TRE were associated with increased nuclear translocation of TFEB, a transcriptional activator of autophagy. Our results suggest that TRE may be considered as a natural compound efficacious for the prevention of hypertension-related target organ damage, with particular regard to stroke and renal damage.

Diminazene Aceturate Stabilizes Atherosclerotic Plaque and Attenuates Hepatic Steatosis in apoE-Knockout Mice by Influencing Macrophages Polarization and Taurine Biosynthesis.

Atherosclerosis and nonalcoholic fatty liver disease are leading causes of morbidity and mortality in the Western countries. The renin-angiotensin system (RAS) with its two main opposing effectors, i.e., angiotensin II (Ang II) and Ang-(1-7), is widely recognized as a major regulator of cardiovascular function and body metabolic processes. Angiotensin-converting enzyme 2 (ACE2) by breaking-down Ang II forms Ang-(1-7) and thus favors Ang-(1-7) actions. Therefore, the aim of our study was to comprehensively evaluate the influence of prolonged treatment with ACE2 activator, diminazene aceturate (DIZE) on the development of atherosclerotic lesions and hepatic steatosis in apoE-/- mice fed a high-fat diet (HFD). We have shown that DIZE stabilized atherosclerotic lesions and attenuated hepatic steatosis in apoE-/- mice fed an HFD. Such effects were associated with decreased total macrophages content and increased α-smooth muscle actin levels in atherosclerotic plaques. Moreover, DIZE changed polarization of macrophages towards increased amount of anti-inflammatory M2 macrophages in the atherosclerotic lesions. Interestingly, the anti-steatotic action of DIZE in the liver was related to the elevated levels of HDL in the plasma, decreased levels of triglycerides, and increased biosynthesis and concentration of taurine in the liver of apoE-/- mice. However, exact molecular mechanisms of both anti-atherosclerotic and anti-steatotic actions of DIZE require further investigations.

Relaxation effect of narirutin on rat mesenteric arteries via nitric oxide release and activation of voltage-gated potassium channels.

Narirutin is one of the most common flavanones found in citrus fruits. The vascular effects of its analogues naringenin and naringin have been reported but its effects on the cardiovascular system are largely unknown. In this study, relaxation effect of narirutin and its mechanisms of action were investigated by measuring isometric tension in rat mesenteric arteries. Patch-clamping was also used to study the effect of narirutin on potassium channels in vascular smooth muscle cells. Moreover, its effects on phosphorylation of endothelial nitric oxide synthase, cAMP level and phosphodiesterase activity in rat mesenteric arteries were studied by Western blot and biochemical assays. The results showed that pre-incubation of rat mesenteric arteries with narirutin had no influence on acetylcholine-induced endothelial-dependent relaxation. However, narirutin caused a direct concentration-dependent relaxation in rat mesenteric arteries. This relaxation effect was comparable to that of narirutin's structural analogue naringenin. Narirutin-induced relaxation was reduced by the removal of endothelium, NG-nitro-L-arginine methyl ester (a nitric oxide synthase inhibitor), and 4-aminopyridine (a voltage-gated potassium channel blocker). In addition, narirutin increased the phosphorylation of endothelial nitric oxide synthase and increased the voltage-dependent potassium current in mesenteric arterial smooth muscle cells. These effects were abolished by protein kinase A inhibitor. Furthermore, narirutin could increase cAMP level and inhibit phosphodiesterase activity in rat mesenteric arteries. In conclusion, narirutin has vasorelaxing effect and the mechanism involves the inhibition of phosphodiesterase, which increases intracellular cAMP, thereby stimulating the endothelial nitric oxide synthase and activating the voltage-gated potassium channels in vascular smooth muscle cells.

Albumin covering maintains endothelial function upon magnetic iron oxide nanoparticles intravenous injection in rats.

Magnetic iron oxide nanoparticles (IONP) present the promising instrument for broad-spectrum of clinical applications, for example, targeted drug delivery. Reactivity of nanoparticles depends on their surface area and material. In the blood plasma IONP are getting covered with an albumin crown, so it was decided to test this shell for biocompatibility. Male Wistar rats were anesthetized and underwent laparotomy. Abdominal aorta was connected to external hemodynamic loop with regulated blood flow. Hind body quarter got step-like blood flow changing from 30 to 150 mmHg and back. This was followed with i.v. injection of IONP, albumin solution or albumin-covered IONP and consequent similar flow changes. Central hemodynamics-heart rate and mean arterial pressure were registered throughout the experiment and no significant changes in these parameters were observed. Hind paw microcirculation level had the same dynamic in all groups under changing blood flow conditions. At the end, venous blood was collected for endothelin-1 and NO evaluation that showed similar changes and no endothelial damage. Mesenteric arteries and femoral artery reactivity were evaluated with wire myography. Mesenteric arteries had the most relaxing function preservation after albumin-covered IONP injection. Given data reveal advantage of albumin-coated IONP so this can be used for further investigations as a vascular-safe vehicle.

KCNQ5 Potassium Channel Activation Underlies Vasodilation by Tea.

BACKGROUND/AIMS: Tea, produced from the evergreen Camellia sinensis, has reported therapeutic properties against multiple pathologies, including hypertension. Although some studies validate the health benefits of tea, few have investigated the molecular mechanisms of action. The KCNQ5 voltage-gated potassium channel contributes to vascular smooth muscle tone and neuronal M-current regulation. METHODS: We applied electrophysiology, myography, mass spectrometry and in silico docking to determine effects and their underlying molecular mechanisms of tea and its components on KCNQ channels and arterial tone. RESULTS: A 1% green tea extract (GTE) hyperpolarized cells by augmenting KCNQ5 activity >20-fold at resting potential; similar effects of black tea were inhibited by milk. In contrast, GTE had lesser effects on KCNQ2/Q3 and inhibited KCNQ1/E1. Tea polyphenols epicatechin gallate (ECG) and epigallocatechin-3-gallate (EGCG), but not epicatechin or epigallocatechin, isoform-selectively hyperpolarized KCNQ5 activation voltage dependence. In silico docking and mutagenesis revealed that activation by ECG requires KCNQ5-R212, at the voltage sensor foot. Strikingly, ECG and EGCG but not epicatechin KCNQ-dependently relaxed rat mesenteric arteries. CONCLUSION: KCNQ5 activation contributes to vasodilation by tea; ECG and EGCG are candidates for future anti-hypertensive drug development.

Extra Virgin Olive Oil Phenols Vasodilate Rat MesentericResistance Artery via Phospholipase C (PLC)-CalciumMicrodomains-Potassium Channels (BKCa) Signals.

Recent evidence suggests that the reason Extra Virgin Olive Oil (EVOO) lowers blood pressure and reduces the risk of developing hypertension is partly due to minor components of EVOO, such as phenols. However, little is still known about the mechanism(s) through which EVOO phenols mediate anti-hypertensive effects. The aim of the present study was to investigate the mechanisms of action of EVOO phenols on mesenteric resistance arteries. A pressure myograph was used to test the effect of EVOO phenols on isolated mesenteric arteries in the presence of specific inhibitors of: 1) BKca channels (Paxillin, 10-5 M); 2) L-type calcium channels (Verapamil, 10-5 M); 3) Ryanodine receptor, RyR (Ryanodine, 10-5 M); 4) inositol 1,4,5-triphosphate receptor, IP3R, (2-Aminoethyl diphenylborinate, 2-APB, 3 × 10-3 M); 5) phospholipase C, PLC, (U73122, 10-5 M), and 6) GPCR-Gαi signaling, (Pertussis Toxin, 10-5 M). EVOO phenols induced vasodilation of mesenteric arteries in a dose-dependent manner, and this effect was reduced by pre-incubation with Paxillin, Verapamil, Ryanodine, 2-APB, U73122, and Pertussis Toxin. Our data suggest that EVOO phenol-mediated vasodilation requires activation of BKca channels potentially through a local increase of subcellular calcium microdomains, a pivotal mechanism on the base of artery vasodilation. These findings provide novel mechanistic insights for understanding the vasodilatory properties of EVOO phenols on resistance arteries.

Braylin induces a potent vasorelaxation, involving distinct mechanisms in superior mesenteric and iliac arteries of rats.

Arterial hypertension is a risk factor for various cardiovascular and renal diseases, representing a major public health challenge. Although a wide range of treatment options are available for blood pressure control, many hypertensive individuals remain with uncontrolled hypertension. Thus, the search for new substances with antihypertensive potential becomes necessary. Coumarins, a group of polyphenolic compounds derived from plants, have attracted intense interest due to their diverse pharmacological properties, like potent antihypertensive activities. Braylin (6-methoxyseselin) is a coumarin identified in the Zanthoxylum tingoassuiba species, described as a phosphodiesterase-4 (PDE4) inhibitor. Although different coumarin compounds have been described as potent antihypertensive agents, the activity of braylin on the cardiovascular system has yet to be investigated. To investigate the vasorelaxation properties of braylin and its possible mechanisms of action, we performed in vitro studies using superior mesenteric arteries and the iliac arteries isolated from rats. In this study, we demonstrated, for the first time, that braylin induces potent vasorelaxation, involving distinct mechanisms from two different arteries, isolated from rats. A possible inhibition of phosphodiesterase, altering the cyclic adenosine monophosphate (cAMP)/cAMP-dependent protein kinase (PKA) pathway, may be correlated with the biological action of braylin in the mesenteric vessel, while in the iliac artery, the biological action of braylin may be correlated with increase of cyclic guanosine monophosphate (cGMP), followed by BKCa, Kir, and Kv channel activation. Together, these results provide evidence that braylin can represent a potential therapeutic use in preventing and treating cardiovascular diseases.

Disrupted eNOS activity and expression account for vasodilator dysfunction in different stage of sepsis.

AIMS: Sepsis is a severe endothelial dysfunction syndrome. The role of endothelial nitric oxide synthase (eNOS) in endothelial dysfunction induced by sepsis is controversial. To explore the role of eNOS in vascular dysfunction. MAIN METHODS: The effect of sepsis on vasodilation and eNOS levels was examined in septic mouse arteries and in cell models. KEY FINDINGS: In early sepsis mouse arteries, endothelium-dependent relaxation decreased and phosphorylation of the inhibitory Thr495 site in endothelial nitric oxide synthase increased. Mechanically, the phosphorylation of endothelial nitric oxide synthase at Thr497 in bovine aortic endothelial cells occurred in a protein kinase C-α dependent manner. In late sepsis, both nitric oxide-dependent relaxation responses and endothelial nitric oxide synthase levels were decreased in septic mice arteries. Endothelial nitric oxide synthase levels expression levels decreased in tumor necrosis factor-α-treated human umbilical vein endothelial cells and this could be prevented by the ubiquitin proteasome inhibitor (MG-132). MG-132 could reverse the decrease in endothelial nitric oxide synthase expression and improve nitric oxide-dependent vasodilator dysfunction in septic mice arteries. SIGNIFICANCE: These data indicate that vasodilator dysfunction is induced by the increased phosphorylation of endothelial nitric oxide synthase in early sepsis and its degradation in late sepsis.

Estrogens and the Angiotensin II Type 2 Receptor Control Flow-Mediated Outward Remodeling in the Female Mouse Mesenteric Artery.

Flow-mediated outward remodeling (FMR) is involved in postischemic revascularization. Angiotensin II type 2 receptor (AT2R), through activation of T-cell-mediated IL-17 production, and estrogens are involved in FMR. Thus, we investigated the interplay between estrogens and AT2R in FMR using a model of ligation of feed arteries supplying collateral pathways in mouse mesenteric arteries in vivo. Arteries were collected after 2 (inflammatory phase), 4 (diameter expansion phase), and 7 days (remodeling completed). We used AT2R+/+ and AT2R-/- ovariectomized (OVX) female mice treated or not with 17-beta-estradiol (E2). Seven days after ligation, arterial diameter was larger in high flow (HF) compared to normal flow (NF) arteries. FMR was absent in OVX mice and restored by E2. AT2R gene expression was higher in HF than in NF arteries only in E2-treated OVX AT2R+/+ mice. CD11b and TNF alpha levels (inflammatory phase), MMP2 and TIMP1 (extracellular matrix digestion), and NOS3 (diameter expansion phase) expression levels were higher in HF than in NF arteries only in E2-treated AT2R+/+ mice, not in the other groups. Thus, E2 is necessary for AT2R-dependent diameter expansion, possibly through activation of T-cell AT2R, in arteries submitted chronically to high blood flow.

Enhanced sympathetic neurotransduction in the superior mesenteric artery in a rat model of heart failure: role of noradrenaline and ATP.

Heart failure (HF) is associated with neurohumoral activation, which in turn leads to an increased peripheral resistance. In mesenteric vasculature, perivascular innervation plays relevant role maintaining vascular tonus and resistance. Therefore, we aimed to determine the possible alterations in superior mesenteric artery (SMA) perivascular innervation function in HF rats. HF was induced by coronary artery occlusion in male Wistar rats, and sham-operated (SO) rats were used as controls. After 12 wk, a greater vasoconstrictor response to electrical field stimulation (EFS) was observed in endothelium-intact and endothelium-denuded SMA of HF rats. Alpha-adrenoceptor antagonist phentolamine diminished this response in a higher magnitude in HF than in SO animals. However, the noradrenaline (NA) reuptake inhibitor desipramine increased EFS-induced vasoconstriction more in segments from HF rats. Besides, EFS-induced NA release was greater in HF animals, due to a higher tyrosine hydroxylase expression and activity. P2 purinoceptor antagonist suramin reduced EFS-induced vasoconstriction only in segments from SO rats, and adenosine 5'-triphosphate (ATP) release was lower in HF than in SO. Moreover, nitric oxide (NO) synthase inhibitor Nω-nitro-L-arginine methyl ester (L-NAME) enhanced EFS-induced vasoconstriction in a similar extent in both groups. HF was not associated with changes in EFS-induced NO release or the vasodilator response to NO donor sodium nitroprusside. In conclusion, HF postmyocardial infarction enhanced noradrenergic function and diminished purinergic cotransmission in SMA and did not change nitrergic innervation. The net effect was an increased sympathetic participation on the EFS-induced vasoconstriction that could help to understand the neurotransduction involved on the control of vascular tonus in HF.NEW & NOTEWORTHY This study reinforces the pivotal role of noradrenergic innervation in the regulation of mesenteric vascular tone in a rat model of heart failure. Moreover, our results highlight the counteracting role of ATP and NA reuptake, and help to understand the signaling pathways involved on the control of vascular tonus and resistance in heart failure postmyocardial infarction.

Simulated sleep apnea alters hydrogen sulfide regulation of blood flow and pressure.

In sleep apnea, airway obstruction causes intermittent hypoxia (IH). In animal studies, IH-dependent hypertension is associated with loss of vasodilator hydrogen sulfide (H2S), and increased H2S activation of sympathetic nervous system (SNS) activity in the carotid body. We previously reported that inhibiting cystathionine γ-lyase (CSE) to prevent H2S synthesis augments vascular resistance in control rats. The goal of this study was to evaluate the contribution of IH-induced changes in CSE signaling to increased blood pressure and vascular resistance. We hypothesized that chronic IH exposure eliminates CSE regulation of blood pressure (BP) and vascular resistance. In rats instrumented with venous catheters, arterial telemeters, and flow probes on the main mesenteric artery, the CSE inhibitor dl-propargylglycine (PAG, 50 mg/kg/day i.v. for 5 days) increased BP in Sham rats but decreased BP in IH rats [in mmHg, Sham (n = 11): 114 ± 4 to 131 ± 6; IH (n = 8): 131 ± 8 to 115 ± 7 mmHg, P < 0.05]. PAG treatment increased mesenteric vascular resistance in Sham rats but decreased it in IH rats (day 5/day 1: Sham: 1.50 ± 0.07; IH: 0.85 ± 0.19, P < 0.05). Administration of the ganglionic blocker hexamethonium (to evaluate SNS activity) decreased mesenteric resistance in PAG-treated Sham rats more than in saline-treated Sham rats or PAG-treated IH rats. CSE immunoreactivity in IH carotid bodies compared with those from Sham rats. However, CSE staining in small mesenteric arteries was less in arteries from IH than in Sham rats but not different in larger arteries (inner diameter > 200 µm). These results suggest endogenous H2S regulates blood pressure and vascular resistance, but this control is lost after IH exposure with decreased CSE expression in resistance size arteries. IH exposure concurrently increases carotid body CSE expression and relative SNS control of blood pressure, suggesting both vascular and carotid body H2S generation contribute to blood pressure regulation.NEW & NOTEWORTHY These results suggest that CSE's protective role in the vasculature is impaired by simulated sleep apnea, which also upregulates CSE in the carotid body. Thus, this enzyme system can exert both pro- and antihypertensive effects and may contribute to elevated SNS outflow in sleep apnea.

APPLICATION OF QUERCETIN FOR CORRECTION OF THE IMPAIRMENT OF THE FUNCTIONAL STATE OF THE ENDOTHELIUS OF VESSELS (CLINICAL AND EXPERIMENTAL STUDY). / ZASTOSUVANNIa KVERTsETYNU DLIa KOREKTsIÏ PORUShEN' FUNKTsIONAL'NOGO STANU ENDOTELIIu SUDYN (KLINIKO-EKSPERYMENTAL'NE DOSLIDZhENNIa).

OBJECTIVE: in the experiment, to investigate the effect of Quercetin on the NO-dependent reactions of isolated vessels involving endothelium and perivascular adipose tissue (PVAT) after a single X-ray irradiation of rats at a sublethal dose. In a clinical study, to investigate the effect of long-term use of Quercetin on the functional state of themicrovascular endothelium in the elderly patients with metabolic syndrome (MS). MATERIAL AND METHODS: Experimental studies were performed on vascular fragments obtained from adult male rats(7-8 months) of the control group, in animals exposed to a single R-irradiation at a dose of 7 Gy and animals irradiated in the same dose, which received Quercetin orally for 14 days three times a week based on 10 mg/kg bodyweight. Fragments of the thoracic aorta (TA) and mesenteric artery (MA) were cleaned of perivascular adipose tissue (PVAT-) or left uncleaned (PVAT+), and then were cut into rings (up to 2 mm). The amplitude of the contractionof the rings TA and MA under the influence of phenylephrine (PE, 3 x 10-6 M), the amplitude of the contraction of therings TA and MA in the presence of a competitive blocker of NO-synthase methyl ester of N-nitro-L-arginine(L-NAME, 10-5 M), the amplitude of relaxation of the rings TA and MA in the presence of N-acetylcysteine (NAC, 10-4 M)were measured. The clinical study examined 110 patients with MS criteria in accordance with ATP III (2001).Patients in the main group for 3 months received Quercetin from the same manufacturer, 80 mg three times a day,patients in the control group received placebo. RESULTS: Single R-irradiation disrupts the regulation of the contractile function of TA and MA, which is evidenced bychanges in the contractile reactions of isolated fragments of these vessels as a response to the action of vasoactivecompounds. Course use of Quercetin in irradiated rats leads to the normalization of contractile and dilatory vascular responses due to partial correction of NO metabolism in the endothelium and PVAT. For the majority of patients(69 %) who received Quercetin, a post-occlusive hyperemia test showed a statistically significant increase of maximal volumetric velocity of the skin blood flow rate and duration of the recovery period to the baseline, which indicates about improvement of vasomotor vascular endothelial function. CONCLUSIONS: Course use of Quercetin improves the functional state of the microvascular endothelium among theelderly people with MS, normalizes contractile and dilatory vascular responses in irradiated rats due to partial correction of NO metabolism in the endothelium and PVAT.

Sulforaphane improves vascular reactivity in mouse and human arteries after "preeclamptic-like" injury.

INTRODUCTION: The widespread maternal endothelial dysfunction that underlies the manifestations of preeclampsia is thought to arise from excessive placental production of antiangiogenic factors and enhanced oxidative stress. Therefore, we assessed whether the natural antioxidant sulforaphane could improve vascular function. METHODS: Cell viability of human umbilical vein endothelial cells (HUVECs) was assessed after 24 or 48 h in normoxia (20% O2) or hypoxia (1% O2) with or without sulforaphane. To model vascular dysfunction associated with preeclampsia, mouse mesenteric arteries were incubated in trophoblast conditioned media (TCM), and human omental arteries incubated in preeclamptic explant media (PEM) with or without sulforaphane. Both media are rich in antiangiogenic compounds associated with preeclampsia. TCM was generated from primary cytotrophoblast cells from term placentae of normotensive, while PEM was generated from explants from preeclamptic women. Reactivity was assessed by wire myography. sulforaphane's actions as a vasodilator were also investigated. RESULTS: Under conditions of hypoxia, sulforaphane improved HUVEC viability. In mouse mesenteric arteries, sulforaphane reduced contraction evoked by potassium (p < 0.001), phenylephrine and endothelin 1 (all p < 0.001). Sulforaphane also inhibited Ca2+-induced contraction (p = 0.014). Sulforaphane prevented TCM-induced augmentation of phenylephrine and angiotensin II-mediated contraction of mouse mesenteric arteries. In human omental arteries, sulforaphane induced vasodilation (p < 0.001), and prevented PEM-induced endothelial dysfunction by restoring arterial sensitivity to the endothelium-dependent vasodilator bradykinin (p = 0.008). DISCUSSION: Sulforaphane causes relaxation in arteries and protects against arterial dysfunction induced by placental-derived antiangiogenic factors, which are known to contribute to the preeclampsia.

Mas Receptor Activation Contributes to the Improvement of Nitric Oxide Bioavailability and Vascular Remodeling During Chronic AT1R (Angiotensin Type-1 Receptor) Blockade in Experimental Hypertension.

Angiotensin (1-7) production increases during AT1R (angiotensin type-1 receptor) blockade. The contribution of Ang (1-7) (angiotensin [1-7]) and its receptor (MasR) to the favorable effect of angiotensin receptor blockers on remodeling and function of resistance arteries remains unclear. We sought to determine whether MasR contributes to the improvement of vascular structure and function during chronic AT1R blockade. Spontaneously hypertensive rats were treated with Ang (1-7) or olmesartan ± MasR antagonist A-779, or vehicle, for 14 days. Blood pressure was measured by tail cuff methodology. Mesenteric arteries were dissected and mounted on a pressurized micromyograph to evaluate media-to-lumen ratio (M/L) and endothelial function. Expression of MasR and eNOS (endothelial nitric oxide synthase) was evaluated by immunoblotting, plasma nitrate by colorimetric assay, and reactive oxygen species production by dihydroethidium staining. Independently of blood pressure, olmesartan significantly reduced M/L and improved NO bioavailability, A-779 prevented these effects. Likewise, Ang (1-7) significantly reduced M/L and NO bioavailability. MasR expression was significantly increased by Ang (1-7) as well as by olmesartan, and it was blunted in the presence of A-779. Both Ang (1-7) and olmesartan increased eNOS expression and plasma nitrite which were reduced by A-779. Superoxide generation was attenuated by olmesartan and Ang (1-7) and was blunted in the presence of A-779. These MasR-mediated actions were independent of AT2R activation since olmesartan and Ang (1-7) increased MasR expression and reduced M/L in Ang II (angiotensin II)-infused AT2R knockout mice, independently of blood pressure control. A-779 prevented these effects. Hence, MasR activation may contribute to the favorable effects of AT1R antagonism on NO bioavailability and microvascular remodeling, independently of AT2R activation and blood pressure control.

A milk-derived pentapeptide reduces blood pressure in advanced hypertension in a CCK system-dependent manner.

We recently found that a peptide that activates the cholecystokinin (CCK) system effectively reduces blood pressure in spontaneously hypertensive rats (SHR) after the development of hypertension, after which hypotensive drugs are sometimes less effective. In this study, we investigated the vasorelaxation and antihypertensive effects of a peptide derived from a milk protein in SHR with advanced hypertension. The vasorelaxing activity was measured using the mesenteric artery isolated from SHR and the systemic blood pressure was measured by the tail-cuff method. KFWGK was released from bovine serum albumin (BSA) and the model peptide after subtilisin digestion. KFWGK relaxed the mesenteric artery and this vasorelaxation activity was inhibited by lorglumide, an antagonist of the CCK1 receptor. KFWGK more potently relaxed the artery from advanced-stage SHR than that from early-stage SHR. Orally administered KFWGK exhibited potent and long-lasting antihypertensive effects in SHR after the development of hypertension (the minimum effective dose was 5 µg kg-1). The KFWGK-induced antihypertensive effects were also blocked by a CCK antagonist, suggesting that it activates the CCK system. In conclusion, KFWGK, a CCK-dependent vasorelaxant peptide, exhibited potent antihypertensive effects in SHR after the development of hypertension.

Aberrant Exon 8/8a Splicing by Downregulated PTBP (Polypyrimidine Tract-Binding Protein) 1 Increases CaV1.2 Dihydropyridine Resistance to Attenuate Vasodilation.

OBJECTIVE: Calcium channel blockers, such as dihydropyridines, are commonly used to inhibit enhanced activity of vascular CaV1.2 channels in hypertension. However, patients who are insensitive to such treatments develop calcium channel blocker-resistant hypertension. The function of CaV1.2 channel is diversified by alternative splicing, and the splicing factor PTBP (polypyrimidine tract-binding protein) 1 influences the utilization of mutually exclusive exon 8/8a of the CaV1.2 channel during neuronal development. Nevertheless, whether and how PTBP1 makes a role in the calcium channel blocker sensitivity of vascular CaV1.2 channels, and calcium channel blocker-induced vasodilation remains unknown. Approach and Results: We detected high expression of PTBP1 and, inversely, low expression of exon 8a in CaV1.2 channels (CaV1.2E8a) in rat arteries. In contrast, the opposite expression patterns were observed in brain and heart tissues. In comparison to normotensive rats, the expressions of PTBP1 and CaV1.2E8a channels were dysregulated in mesenteric arteries of hypertensive rats. Notably, PTBP1 expression was significantly downregulated, and CaV1.2E8a channels were aberrantly increased in dihydropyridine-resistant arteries compared with dihydropyridine-sensitive arteries of rats and human. In rat vascular smooth muscle cells, PTBP1 knockdown resulted in shifting of CaV1.2 exon 8 to 8a. Using patch-clamp recordings, we demonstrated a concomitant reduction of sensitivity of CaV1.2 channels to nifedipine, due to the higher expression of CaV1.2E8a isoform. In vascular myography experiments, small interfering RNA-mediated knockdown of PTBP1 attenuated nifedipine-induced vasodilation of rat mesenteric arteries. CONCLUSIONS: PTBP1 finely modulates the sensitivities of CaV1.2 channels to dihydropyridine by shifting the utilization of exon 8/8a and resulting in changes of responses in dihydropyridine-induced vasodilation.

Cadmium exposure activates NADPH oxidase, renin-angiotensin system and cyclooxygenase 2 pathways in arteries, inducing hypertension and vascular damage.

Exposure to high concentrations of cadmium (Cd), widely used in many industries and found in air, food and contaminated water, is not uncommon. Cd damages the cardiovascular system, but the vascular mechanisms involved are not fully understood. This study investigated the mechanisms involved in cardiovascular damage after exposure to high Cd concentrations. Three-month-old male Wistar rats were treated intraperitoneally for 14 days with distilled water (Untreated group) or 1 mg/kg cadmium chloride (Cd group). We investigated the systolic blood pressure (SBP) and vascular reactivity of mesenteric resistance arteries (MRA) and the aorta by analysing contractile and relaxation responses in the absence and presence of the endothelium; we also evaluated pathways involved in vascular tone regulation. Superoxide anion production, COX-2 protein expression and in situ detection of COX-2, AT-1, and NOX-1 were evaluated. Oxidative status, creatinine level and angiotensin-converting enzyme (ACE) activity in plasma were also evaluated. Fourteen-day exposure to a high Cd concentration induced hypertension associated with vascular dysfunction in MRA and the aorta. In both vessels, there was increased participation of cyclooxygenase 2 (COX2), angiotensin II type 1 (AT1) receptor and NOX1. MRA also presented endothelial dysfunction, denoted by impaired acetylcholine-mediated relaxation. All vascular changes were accompanied by increased reactive oxygen species production and COX2, NOX1 and AT1 receptor expression in vascular tissue. Overall, high Cd concentrations induced cardiovascular damage: hypertension, endothelial dysfunction and vascular damage in conductance and resistance arteries, NADPH oxidase, renin-angiotensin system and COX2 pathway activation.