Vascular Relaxation Research Articles

Impact of metabolic therapy on the state of cerebral hemodynamics in hypoestrogenemia

Objective. To investigate the impact of therapy with Mildronate® on the state of cerebral hemodynamics, on vascular wall remodeling and endothelial dysfunction in women with hypertension and estradiol deficiency. Subjects and methods. The investigation enrolled 37 patients (mean age, 43.0±3.5 years) with Stage I–II hypertension, reduced estradiol and elevated follicle-stimulating hormone (FSH) levels, who formed a study group. The patients in this group received Mildronate® in addition to standard therapy. A control group consisted of 38 healthy women (mean age 43.5±3.4 years) without chronic diseases affecting intracardiac and cerebral hemodynamics. Complete medical histories were taken from all the patients who underwent a mandatory laboratory test (including estradiol and FSH levels), ECG, and duplex scanning of the great cerebral arteries. Results. The features of vascular bed remodeling, the state of cerebral hemodynamics, and endothelial dysfunction in the examinees can assume that hypoestrogenemia may be a factor contributing to the progression of hypertension and the development of complications, such as cerebrovascular accidents. Conclusion. The study results have shown that Mildronate® is well tolerated by patients and is an effective treatment, showing a positive therapeutic effect on endothelium-dependent vascular relaxation, vascular remodeling, and whole-brain hemodynamics.

Endothelial PAR2 activation evokes resistance artery relaxation.

Protease-activated receptor-1 & -2 (PAR1 and PAR2) are expressed widely in cardiovascular tissues including endothelial and smooth muscle cells. PAR1 and PAR2 may regulate blood pressure via changes in vascular contraction or relaxation mediated by endothelial Ca2+ signaling, but the mechanisms are incompletely understood. By using single-cell Ca2+ imaging across hundreds of endothelial cells in intact blood vessels, we explored PAR-mediated regulation of blood vessel function using PAR1 and PAR2 activators. We show that PAR2 activation evoked multicellular Ca2+ waves that propagated across the endothelium. The PAR2-evoked Ca2+ waves were temporally distinct from those generated by muscarinic receptor activation. PAR2 activated distinct clusters of endothelial cells, and these cells were different from those activated by muscarinic receptor stimulation. These results indicate that distinct cell clusters facilitate spatial segregation of endothelial signal processing. We also demonstrate that PAR2 is a phospholipase C-coupled receptor that evokes Ca2+ release from the IP3 -sensitive store in endothelial cells. A physiological consequence of this PAR2 signaling system is endothelium-dependent relaxation. Conversely, PAR1 activation did not trigger endothelial cell Ca2+ signalingnor relax or contract mesenteric arteries. Neither did PAR1 activators alter the response to PAR2 or muscarinic receptor activation. Collectively, these results suggest that endothelial PAR2 but not PAR1 evokes mesenteric artery relaxation by evoking IP3 -mediated Ca2+ release from the internal store. Sensing mediated by PAR2 receptors is distributed to spatially separated clusters of endothelial cells.

Calciprotein Particles Induce Endothelial Dysfunction by Impairing Endothelial Nitric Oxide Metabolism.

Calciprotein particles (CPPs) are associated with the development of vascular calcifications in chronic kidney disease. The role of endothelial cells (ECs) in this process is unknown. Here, we investigated the interaction of CPPs and ECs, thereby focusing on endothelial nitric oxide metabolism and oxidative stress. CPPs were generated in calcium- and phosphate-enriched medium. Human umbilical vein endothelial cells were exposed to different concentrations of CPPs (0-100 µg/mL) for 24 or 72 hours. Ex vivo porcine coronary artery rings were used to measure endothelial cell-dependent vascular smooth muscle cell relaxation after CPP exposure. Serum samples from an early chronic kidney disease cohort (n=245) were analyzed for calcification propensity (measure for CPP formation) and nitrate and nitrite levels (NOx). CPP exposure for 24 hours reduced eNOS (endothelial nitric oxide synthase) mRNA expression and decreased nitrite production, indicating reduced nitric oxide bioavailability. Also, 24-hour CPP exposure caused increased mitochondria-derived superoxide generation, together with nitrotyrosine protein residue formation. Long-term (72 hours) exposure of human umbilical vein endothelial cells to CPPs induced eNOS uncoupling and decreased eNOS protein expression, indicating further impairment of the nitric oxide pathway. The ex vivo porcine coronary artery model showed a significant reduction in endothelial-dependent vascular smooth muscle cell relaxation after CPP exposure. A negative association was observed between NOx levels and calcification propensity (r=-0.136; P=0.049) in sera of (early) chronic kidney disease patients. CPPs cause endothelial cell dysfunction by impairing nitric oxide metabolism and generating oxidative stress. Our findings provide new evidence for direct effects of CPPs on ECs and pathways involved.

Soluble Guanylyl Cyclase Activators-Promising Therapeutic Option in the Pharmacotherapy of Heart Failure and Pulmonary Hypertension.

Endogenous nitric oxide (NO)-dependent vascular relaxation plays a leading role in the homeostasis of the cardiovascular, pulmonary, and vascular systems and organs, such as the kidneys, brain, and liver. The mechanism of the intracellular action of NO in blood vessels involves the stimulation of the activity of the soluble cytosolic form of guanylyl cyclase (soluble guanylyl cyclase, sGC), increasing the level of cyclic 3'-5'-guanosine monophosphate (cGMP) in smooth muscle and subsequent vasodilation. In recent years, a new group of drugs, soluble guanylyl cyclase stimulators, has found its way into clinical practice. Based on the CHEST-1 and PATENT-1 trials, riociguat was introduced into clinical practice for treating chronic thromboembolic pulmonary hypertension (CTEPH). In January 2021, the FDA approved the use of another drug, vericiguat, for the treatment of heart failure.

Vascular Relaxation and Blood Pressure Lowering Effects of Prunus mume in Rats.

Prunus mume Siebold et Zuccarini is mainly consumed as processed fruits in beverages, vinegar, alcohol, or fruit syrup; studies have reported various functional effects. Many pharmacological and functional studies exist on fruit extracts or processed foods using fruits, however, efficacy studies on various parts of P. mume, including the bark, branches, flowers, and leaves, have not been sufficiently conducted. A previous study revealed that a 70% ethanol extract of P. mume branches induced vascular endothelium-dependent vasorelaxant effects in rat thoracic aortic rings. Therefore, we hypothesized that various parts (the fruits, flowers, leaves, and bark) might have vasorelaxant effects. We evaluated the effects of P. mume extracts on the vascular relaxation of isolated rat thoracic aorta and hypotensive effects in spontaneous hypertensive rats (SHR). A 70% ethanol extract of P. mume bark (PBaE) was the most effective, thus, we investigated its vasorelaxant mechanisms and hypotensive effects. PBaE lowered the blood pressure in SHR and induced the vascular endothelium-dependent relaxation of isolated rat aortic rings via the NO/sGC/cGMP and the PGI2 pathways in the vascular smooth muscle. Potassium channels, such as KCa, KATP, KV, and Kir, were partially associated with a PBaE-induced vasorelaxation. Therefore, PBaE might help prevent and treat hypertension.

Microcirculation and Physical Exercise In Hypertension.

Hypertension is associated with important alterations in the morphology of small arteries and arterioles. Vascular-specific manifestations are changes in the structure and function of vascular smooth muscle cells, extracellular matrix, perivascular tissues, and endothelial cells. Arteriole and capillary remodeling and capillary rarefaction have been observed in hypertensive animals and human beings which contribute to increased vascular resistance. An impairment of different angiogenetic factors, such as VEGF (vascular endothelial growth factor), VEGFR-2 (vascular endothelial growth factor receptor-2), TIMP-1 (tissue inhibitor matrix metalloproteinases-1), and TSP-1 (thrombospondin-1), seems to be responsible for the reduction of the microvascular network. Exercise training has been shown to improve vascular structure and function in hypertension not only in the large arteries but also in the peripheral circulation. Exercise training may regress microvascular remodeling and normalize capillary density, leading to capillary growth possibly by increasing proangiogenic stimuli such as VEGF. Exercise enhances endothelium-dependent vascular relaxation through nitric oxide release increase and oxidative stress reduction. Other mechanisms include improved balance between prostacyclin and thromboxane levels, lower circulating levels of endothelin-1, attenuation of infiltration of immune cells into perivascular adipose tissue, and increase of local adiponectin secretion. In addition, exercise training favorably modulates the expression of several microRNAs leading to a positive modification in muscle fiber composition. Identifying the bioactive molecules and biological mechanisms that mediate exercise benefits through pathways that differ from those used by antihypertensive drugs may help to improve our knowledge of hypertension pathophysiology and facilitate the development of new therapeutic strategies.

MPRα and PR co-operate in progesterone inhibition of endothelial cell focal adhesion.

Progesterone causes vascular smooth muscle cell relaxation through membrane progesterone receptors (mPRs), which are members of the progestin and adipoQ receptor (PAQR) family, and nuclear PRs (nPRs). However, beneficial vascular effects of progesterone in preventing pre-atherosclerosis and the involvement of mPRs and nPRs remain unclear. The results show short- to long-term treatments with 100 nM progesterone (P4) and specific agonists for mPRs, OD 02-0, and nPRs, R5020, inhibited pre-atherosclerotic events in human umbilical vein endothelial cells (HUVECs), decreasing focal adhesion (FA) by monocytes, FA signaling, HUVEC migration and invasion, and vinculin expression. Progesterone and OD 02-0, but not R5020, inhibited phosphorylation of Src and focal adhesion kinase, critical kinases of FA signaling, within 20 min and migration and invasion of HUVECs and monocyte adhesion after 3 h. These inhibitory P4 and 02-0 effects were attenuated with MAP kinase and Pi3k inhibitors, indicating involvement of these kinases in this mPR-mediated action. However, after 16 h, OD 02-0 was no longer effective in inhibiting FA signaling, while both progesterone and R5020 decreased the activity of the two kinases. Knockdown of receptor expression with siRNA confirmed that mPRα mediates short-term and nPR long-term inhibitory effects of progesterone on FA signaling. Thus, progesterone inhibition of FA signaling and pre-atherosclerosis is coordinated through mPRα and nPRs.

Advances in the study of the vascular protective effects and molecular mechanisms of hawthorn (Crataegus anamesa Sarg.) extracts in cardiovascular diseases.

Hawthorn belongs to the rose family and is a type of functional food. It contains various chemicals, including flavonoids, terpenoids, and organic acid compounds. This study aimed to review the vascular protective effects and molecular mechanisms of hawthorn and its extracts on cardiovascular diseases (CVDs). Hawthorn has a wide range of biological functions. Evidence suggests that the active components of HE reduce oxidative stress and inflammation, regulate lipid levels to prevent lipid accumulation, and inhibit free cholesterol accumulation in macrophages and foam cell formation. Additionally, hawthorn extract (HE) can protect vascular endothelial function, regulate endothelial dysfunction, and promote vascular endothelial relaxation. It has also been reported that the effective components of hawthorn can prevent age-related endothelial dysfunction, increase cellular calcium levels, cause antiplatelet aggregation, and promote antithrombosis. In clinical trials, HE has been proved to reduce the adverse effects of CVDs on blood lipids, blood pressure, left ventricular ejection fraction, heart rate, and exercise tolerance. Previous studies have pointed to the benefits of hawthorn and its extracts in treating atherosclerosis and other vascular diseases. Therefore, as both medicine and food, hawthorn can be used as a new drug source for treating cardiovascular diseases.

PS-B02-12: EFFECTS OF ULTRAVIOLET LIGHT ON BLOOD PRESSURE AND LEFT VENTRICULAR FUNCTION

Ultraviolet light (UV), induces the activation of constitutive nitric oxide synthases, which produces nitric oxide (NO) of vascular relaxation factor. We hypothesize that UV-induced production of NO could have beneficial effect on hypertension. Twelve 6-week-old salt-sensitive hypertensive rats (Dahl-Iwai salt-sensitive DIS/Eis, Japan Society for the Study of Hypertension, Shizuoka, Japan) were used in this study. These rats were fed a high-salt diet containing 8%NaCl until 10 weeks of age and were then randomly divided into three groups i.e. baseline group (group non-UV), 0 h post UV (group UV 0 h), and 6 h post UV (group UV 6 h). The rats were irradiated with UVA and UVB lamps at an intensity of 100 mJ/cm2. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured by using tail-cuff method (BP-98A; Softron Co., Ltd., Tokyo, Japan). We evaluated left ventricular (LV) systolic and diastolic function using echocardiography with a 12 MHz transducer connected to a Xario ultrasound system (Toshiba Medical Systems Co., Tochigi, Japan). Interventricular septal thickness, LV posterior wall thickness, and LV end-diastolic and end-systolic diameters (LVDd and LVDs) were obtained from a short-axis view. Percent LV fractional shortening (%LVFS) was calculated as an index of LV systolic function. Peak flow velocities at the mitral level during rapid filling (E) and deceleration time (Dct), and peak early diastolic mitral annular velocity which indicate LV diastolic function, were measured using pulsed and tissue Doppler echocardiography. Histological skin tissue sections were fixed with 4% paraformaldehyde phosphate buffer solution for 24 h at room temperature, embedded in paraffin, sectioned transversely (thickness, 3 μm), and stained with hematoxylin-eosin to evaluate the impairments of skin. The SBP and DBP were lower in group UV 6 h than group non-UV and group UV 0 h. In contrast, there were no significant differences in heart rate and body weight among the three groups. The peak early diastolic mitral annular velocity was greater in group UV 6 h than group non-UV and group UV 0 h. LVDd, LVDs, and %LVFS were not significantly different among the three groups. We did not find the impairments in skin after UV irradiation. UVA and UVB may play an important role in regulating not only blood pressure but also LV function.

Trophoblastic mitochondrial DNA induces endothelial dysfunction and NLRP3 inflammasome activation: Implications for preeclampsia.

Preeclampsia (PE) is characterised by systemic vascular endothelium dysfunction. Circulating trophoblastic secretions contribute to endothelial dysfunction, resulting in PE; however, the underlying mechanisms remain unclear. Herein, we aimed to determine the potential correlation between the release of trophoblastic mitochondrial deoxyribonucleic acid (DNA) (mtDNA) and endothelium damage in PE. Umbilical cord sera and tissues from patients with PE were investigated for inflammasome activation. Following this, trophoblastic mitochondria were isolated from HTR-8/SVneo trophoblasts under 21% oxygen (O2) or hypoxic conditions (1% O2 for 48h) for subsequent treatments. Primary human umbilical veinendothelial cells (HUVECs) were isolated from the human umbilical cord and then exposed to a vehicle (phosphate-buffered saline [PBS]), mtDNA, hypo-mtDNA, or hypo-mtDNA with INF39 (nucleotide oligomerisation domain-like receptor family pyrin domain containing 3 [NLRP3]-specific inhibitor) for 12h before flow cytometry and immunoblotting. The effects of trophoblastic mtDNA on the endothelium were further analysed in vivo using enzyme-linked immunosorbent assay (ELISA) and vascular reactivity assay. The effects of mtDNA on vascular phenotypes were also tested on NLRP3 knockout mice. Elevated interleukin (IL)-1β in PE sera was accompanied by NLRP3 inflammasome activation in cord tissues. In vitro and in vivo experiments revealed that the release of trophoblastic mtDNA could damage the endothelium via NLRP3 activation, resulting in the overexpression of NLRP3, caspase-1 p20, IL-1β p17, and gasdermin D (GSDMD); reduced endothelial nitric oxide synthase (eNOS) levels; and impaired vascular relaxation. Flow cytometric analysis confirmed that extensive cell death was induced by mtDNA, and simultaneously, a more pronounced pro-apoptotic effect was caused by hypoxia-treated trophoblastic mtDNA. The NLRP3 knockout or pharmacologic NLRP3 inhibition partially reversed tumour necrosis factor-α (TNF-α) and IL-1β levels and endothelium-dependent vasodilation in mice. These findings demonstrate that trophoblastic mtDNA induced NLRP3/caspase-1/IL-1β signalling activation, eNOS-related endothelial injury, and vasodilation dysfunction in PE.

PS-BPB01-6: PROTECTIVE NOX4 EFFECT IN ENDOTHELIAL CELLS INVOLVES ACTIVATION OF TRANSIENT RECEPTOR POTENTIAL MELASTATIN 2 (TRPM2) CATION CHANNEL

Objective: In endothelial cells, Nox4 is the most prevalent isoform and, in contrast to other Noxes, which generate superoxide O2, Nox4 produces mainly H2O2. Low H2O2 levels have been described to lower blood pressure, which suggests that a certain level of reactive oxygen species (ROS) can have protective effects on the cardiovascular system. We demonstrated that TRPM2 is a target of H2O2 in vascular cells. TRPM2 is a redox-sensitive Ca2+ channel and once activated leads to Ca2 influx. Endothelial dysfunction involves a reduction in eNOS activation by Ca2+ and is potentiated in the absence of Nox4. As TRPM2 channel is a H2O2 sensor and regulates Ca2+ entry, we questioned whether protective Nox4 effect in endothelial cells involves the H2O2-TRPM2-Ca2+ axis, with consequent regulation of NO signalling. Design and Methods: WT and TTRhRen hypertensive mice were crossed with Nox4 KO mice. Vascular function was measured by wire myograph in resistance arteries. ROS and H2O2 generation were assessed by lucigenin and amplex red, and Ca2+ influx by fluorescence microscopy in rat aortic endothelial cells (RAEC). eNOS activation was assessed by immunoblotting. Results: Blood pressure was significantly increased in TTRhRen (130.3 ± 7.0 mmHg) and TTRhRen/Nox4 KO mice (141.3 ± 18 mmHg) versus control mice (98.1 ± 8.0 mmHg). TTRhRen mice had reduced endothelium-dependent relaxation (Emax: WT 83.5 ± 4.03 vs TTRhRen 59.1 ± 3.5); an effect worsened by Nox4 KO (37.9 ± 5.4), p < 0.05. The TRPM2 activator, ADPR, improved vascular relaxation in TTRhRen/Nox4 KO mice (75.9 ± 7.7); an effect recapitulated by H2O2 (74.2 ± 15.4), p < 0.05. Ang II-induced ROS and H2O2 generation in RAEC, effect reversed by Nox4 siRNA and followed by increased Ca2+ influx (AUC - Ca2+: 20440.3333 ± 1870.9), important in eNOS activation. Ang II-induced Ca2+ influx in endothelial cells was reduced by TRPM2 siRNA, TRPM2 inhibitors (AUC - Ca2+: 8-br-cADPR 15232.2 ± 1052.1; Olaparib 14952.6 ± 843.2 and 2-APB 13270.8333 ± 277.4, p < 0.05) and by Nox4 siRNA and Nox4 inhibitor GKT137831 (AUC - Ca2+: GKT 15067.5 ± 255.6). Ang II-induced eNOS activation (Ser1177) (%: 72.3 ± 24.7) and NO release were blocked by Nox4 and TRPM2 sirNA, GKT137831, PEG-catalase and the TRPM2 inhibitor 8-br-cADPR (p < 0.05). Conclusions: We defined a novel molecular pathway in endothelial cells, where Nox4-induced H2O2 production activates PARP/TRPM2 signalling followed by Ca2+ influx, eNOS activation and NO release. The absence of Nox4 impairs Ca2+ homeostasis leading to endothelial dysfunction, an effect exacerbated in hypertension. The protective role of Nox4 corroborates the idea that the use of antioxidants based on the sole evidence that decreased oxidative stress is cardioprotective, it is not effective.

Vanillin Induces Relaxation in Rat Mesenteric Resistance Arteries by Inhibiting Extracellular Ca2+ Influx.

Vanillin is a phenolic aldehyde, which is found in plant species of the Vanilla genus. Although recent studies have suggested that vanillin has various beneficial properties, the effect of vanillin on blood vessels has not been studied well. In the present study, we investigated whether vanillin has vascular effects in rat mesenteric resistance arteries. To examine the vascular effect of vanillin, we measured the isometric tension of arteries using a multi-wire myograph system. After the arteries were pre-contracted with high K+ (70 mM) or phenylephrine (5 µM), vanillin was administered. Vanillin induced concentration-dependent vasodilation. Endothelial denudation or treatment of eNOS inhibitor (L-NNA, 300 μM) did not affect the vasodilation induced by vanillin. Treatment of K+ channel inhibitor (TEA, 10 mM) or sGC inhibitor (ODQ, 10 μM) or COX-2 inhibitor (indomethacin, 10 μM) did not affect the vanillin-induced vasodilation either. The treatment of vanillin decreased the contractile responses induced by Ca2+ addition. Furthermore, vanillin significantly reduced vascular contraction induced by BAY K 8644 (30 nM). Vanillin induced concentration-dependent vascular relaxation in rat mesenteric resistance arteries, which was endothelium-independent. Inhibition of extracellular Ca2+ influx was involved in vanillin-induced vasodilation. Treatment of vanillin reduced phopsho-MLC20 in vascular smooth muscle cells. These results suggest the possibility of vanillin as a potent vasodilatory molecule.

The Synthetic Flavonoid Hidrosmin Improves Endothelial Dysfunction and Atherosclerotic Lesions in Diabetic Mice.

In diabetes, chronic hyperglycemia, dyslipidemia, inflammation and oxidative stress contribute to the progression of macro/microvascular complications. Recently, benefits of the use of flavonoids in these conditions have been established. This study investigates, in two different mouse models of diabetes, the vasculoprotective effects of the synthetic flavonoid hidrosmin on endothelial dysfunction and atherogenesis. In a type 2 diabetes model of leptin-receptor-deficient (db/db) mice, orally administered hidrosmin (600 mg/kg/day) for 16 weeks markedly improved vascular function in aorta and mesenteric arteries without affecting vascular structural properties, as assessed by wire and pressure myography. In streptozotocin-induced type 1 diabetic apolipoprotein E-deficient mice, hidrosmin treatment for 7 weeks reduced atherosclerotic plaque size and lipid content; increased markers of plaque stability; and decreased markers of inflammation, senescence and oxidative stress in aorta. Hidrosmin showed cardiovascular safety, as neither functional nor structural abnormalities were noted in diabetic hearts. Ex vivo, hidrosmin induced vascular relaxation that was blocked by nitric oxide synthase (NOS) inhibition. In vitro, hidrosmin stimulated endothelial NOS activity and NO production and downregulated hyperglycemia-induced inflammatory and oxidant genes in vascular smooth muscle cells. Our results highlight hidrosmin as a potential add-on therapy in the treatment of macrovascular complications of diabetes.

In vitro effect of relaxin in the rat corpus cavernosum under hyperglycemic and normoglycemic conditions.

Relaxin, an endogenous peptide hormone, elicits vascular relaxation by its direct effect or by modulating the endothelium-dependent relaxation response and is clinically evaluated for the treatment of coronary artery disease. However, its effect on penile tissue has not been explored yet. This study aimed to investigate the effect of serelaxin, recombinant human relaxin-2, on rat corpus cavernosum (CC) under healthy and hyperglycemic conditions. Strips of CC obtained from thirty-nine male Wistar rats weighing 300-350 g were used in organ baths for isometric tension studies to investigate the serelaxin-mediated relaxation (10-12-10-7 M) under normoglycemic conditions and the effect of serelaxin on endothelium-dependent [nitric oxide (NO)- and prostacyclin-mediated] relaxation responses under hyperglycemic conditions. The in vitro hyperglycemia model was created by 3 h of incubation with 44 mM glucose monohydrate +120 μM methylglyoxal. NO-dependent relaxation responses were evaluated by cumulative acetylcholine (10-9-10-4 M) administration in the presence of indomethacin (10-6 M). Prostacyclin-mediated relaxation was evaluated by cumulative administration of iloprost (10-9-10-6 M), a prostacyclin analog. Maximum relaxation responses to serelaxin were not significantly different compared to the time-control (p = 0.480). Three hours of incubation of rat CC in hyperglycemic conditions impaired NO- and prostacyclin-mediated relaxation responses (p = 0.032 and p = 0.047, respectively). Serelaxin coincubation worsened NO-mediated relaxation responses (p = 0.016) but did not affect prostacyclin-mediated responses (p = 0.425). Together, our results demonstrate that in vitro administration of serelaxin does not cause relaxation in penile tissue and short-term in vitro serelaxin treatment in hyperglycemic conditions mimicked diabetes modulates endothelium-dependent responses by worsening NO-mediated responses. Serelaxin exerts different effects via different mechanism on endothelium-dependent responses depending on the dose and duration of exposure. Therefore, proper timing and dosing of serelaxin administration in the penile tissue need to be investigated in further studies in diabetic animal models.

Dietary Effects of Chromium Picolinate and Chromium Nanoparticles in Wistar Rats Fed with a High-Fat, Low-Fiber Diet: The Role of Fat Normalization

We aimed to evaluate how feeding a high-fat-low-fiber (F) diet to rats and dietary intervention with the implementation of a standard-fat-and-fiber (S) diet affects the response of the cardiovascular system to chromium (III) picolinate (Cr-Pic) and, alternatively, chromium nanoparticles (Cr-NPs). Young male Wistar Han rats (n/group = 12) from either the fatty group (18 weeks on F diet) or the intervention group (9 weeks on F diet + 9 weeks on S diet) received a pharmacologically relevant dose of 0.3 mg Cr/kg body weight in the form of Cr-Pic or Cr-NPs for 9 weeks. Our study on rats confirmed the pro-inflammatory effect of an F diet administered for 18 weeks. In the intervention group, both Cr-Pic and Cr-NPs decreased heart glutathione ratio (GSH+GSSG), enhanced participation of nitric oxide (NO) derived from inducible NO synthase (iNOS) in vascular relaxation to acetylcholine (ACh), increased the vasodilator net effect of cyclooxygenase-2 (COX-2)-derived prostanoids, and increased the production of superoxide anion (O2.-) in aortic rings. Meanwhile, in the fatty group, there was increased heart superoxide dismutase (SOD), decreased heart catalase (CAT), and reduced sensitivity in pre-incubated aortic rings to endogenous prostacyclin (PGI2). The factors that significantly differentiated Cr-NPs from Cr-Pic were (i) decreased blood antioxidant capacity of water-soluble compounds (0.75-fold, p = 0.0205), (ii) increased hydrogen peroxide (H2O2) production (1.59-fold, p = 0.0332), and (iii) modified vasodilator response due to PGI2 synthesis inhibition (in the intervention group) vs. modified ACh-induced vasodilator response due to (iv) COX inhibition and v) PGI2 synthesis inhibition with thromboxane receptor blockage after 18 weeks on F diet (in the fatty group). Our results show that supplementation with Cr-Pic rather than with Cr-NPs is more beneficial in rats who regularly consumed an F diet (e.g., for 18 weeks). On the contrary, in the intervention group (9 weeks on F diet + 9 weeks of dietary fat normalization (the S diet)), Cr-Pic and Cr-NPs could function as pro-oxidant agents, initiating free-radical reactions that led to oxidative stress.

Abstract 12949: Altered Fatty Acids and Oxylipins Metabolism Differentiate Isolated Post-Capillary versus Combined Pre- and Post-Capillary Pulmonary Hypertension

Introduction: Pulmonary hypertension due to left heart disease (Group 2) is the most common type of pulmonary hypertension and has two subtypes: isolated post-capillary pulmonary hypertension (Ipc-PH) and combined post-capillary and pre-capillary pulmonary hypertension (Cpc-PH). Little is known about the molecular characteristics that distinguish these two subphenotypes or if Cpc-PH shares molecular similarities to pulmonary arterial hypertension (PAH), as has previously been suggested. Many lipid metabolites, including a diverse group of bioactive lipid mediators known as oxylipins, have been associated with cardiovascular disease and other inflammatory conditions. Therefore, we sought to characterize oxylipin and other bioactive lipid profiles among patients with Ipc-PH and Cpc-PH, as well as those with PAH. Methods: We studied 129 patients with Ipc-PH (n=38), Cpc-PH (n=52), or PAH (n=39) between June 2006 and March 2012. Liquid chromatography-mass spectrometry was used to assess 350 lipid metabolite analytes in each patient. Results: In multivariable analyses adjusting for age, sex, BMI, and pulmonary hypertension medications, we observed 34 metabolites were significantly increased and 10 were decreased in Ipc-PH compared to Cpc-PH (Figure). Among these same metabolites, only 9 were significantly different between Cpc-PH and PAH. Compared to patients with Ipc-PH, those with Cpc-PH had elevated levels of fatty acyl esters of hydroxy fatty acids and polyunsaturated fatty acids as well as lower levels of anti-inflammatory and pulmonary vascular relaxant oxylipins. Conclusions: Overall, these findings suggest that Cpc-PH may diverge from Ipc-PH and share some molecular similarities with PAH. Identifying key molecular targets involved in Cpc-PH pathophysiology may be critical for diagnostic purposes and in the development of novel therapeutic avenues for patients with Cpc-PH.

Chemical characterization of Passiflora edulis extracts and their in vitro antioxidant, anti-inflammatory, anti-lipid activities, and ex-vivo vasodilation effect

Passion fruit is a dietary plant with the protective proterties against many diseases such as cardiovascular diseases. The aim of this study was to explore the biological properties (anti-oxidant, anti-inflammatory, anti-lipid, and vascular relaxation) of the P. edulis extracts obtained from seed (PSEE) and fruit (PFWE). Thin-layer chromatography (TLC) and HPLC were used to analyze the phytochemical constituents in the extracts. Antioxidant and enzyme inhibition properties were examined. Anti-inflammatory activities of PFWE and PSEE were evaluated in lipopolysaccharide (LPS)-induced macrophages and ex-vivo vascular relaxation were also determined. A high contents of piceatannol and polyphenolic stilbene were found in PSEE extracts. On the other hand, beta-carotene and gamma-tocopherol were predominant in PFWE. PFWE exhibited stronger anti-oxidant activity than PSEE. Both PSEE and PFWE showed significant inhibition of lipase and cholesterol esterase activities. However, only PFWE showed minimal inhibitory effect against HMG-CoA reductase. PSEE and PFWE caused a significant reduction of nitric oxide level in LPS-induced inflammation in RAW264.7 cells. Both extracts also showed ex-vivo vasorelaxation of rat aortic rings. It has been demonstrated that PFWE and PSEE possesses anti-oxidant activity, anti-inflammatory activity, pancreatic lipase and cholesterol esterase, and ex-vivo vasorelaxation of rat aortic rings, however, the activity of HMG-CoA reductase was inhibited by only PFWE. These findings suggest the beneficial effect of PSEE and PFWE against hyperlipidemia thus preventing the development of hypertension. However, further investigations in animal are needed to elucidate.

1,25(OH)2D3 alleviates LPS-induced preeclampsia-like rats impairment in the protective effect by TLR4/NF-kB pathway

IntroductionAccumulating epidemiological studies support that Vitamin D deficiency is associated with the pathogenesis of preeclampsia. However, it is unknown whether vitamin D can be used as a treatment for preeclampsia. This study aimed to explore whether vitamin D supplementation could improve the rat model of preeclampsia. MethodsLPS was used to establish a rat model of preeclampsia. Inflammatory cytokines were examined by QRT-PCR and ELISA assays, and the concentration of sfit-1 and NO was assessed by ELISA. Analyzing the pathological features of the placenta with hematoxylin-eosin. The spatial learning and memory abilities of offspring were evaluated by the Morris water maze. Immune histology and western blot were performed to evaluate the expression levels of inflammatory pathway-associated Factor and vascular endothelium-associated Factor in the placenta. ResultsVitamin D treatment reduced the blood pressure and urine protein of PE model rats, alleviated pathological damage to the placenta and pregnancy outcomes, and protected PE offspring from impaired memory and learning abilities. Moreover, TLR4 signaling pathway in the placenta was inhibited. Furthermore, vitamin D supplementation increased the expression of endothelial growth factor and vascular relaxing factor, and there was no significant difference compared with the control group. DiscussionWe generated the result that Vitamin D supplementation significantly improved the phenotype of preeclampsia and adverse pregnancy outcome caused by an abnormal inflammatory reaction and endothelial dysfunction in the placenta, and improved the learning and cognitive ability of offspring.

Endothelial-Specific Expression of CIDEC Improves High-Fat Diet-Induced Vascular and Metabolic Dysfunction.

Cell death-inducing DNA fragmentation factor-α-like effector C (CIDEC), originally identified to be a lipid droplet-associated protein in adipocytes, positively associates with insulin sensitivity. Recently, we discovered that it is expressed abundantly in human endothelial cells and regulates vascular function. The current study was designed to characterize the physiological effects and molecular actions of endothelial CIDEC in the control of vascular phenotype and whole-body glucose homeostasis. To achieve this, we generated a humanized mouse model expressing endothelial-specific human CIDEC (E-CIDECtg). E-CIDECtg mice exhibited protection against high-fat diet-induced glucose intolerance, insulin resistance, and dyslipidemia. Moreover, these mice displayed improved insulin signaling and endothelial nitric oxide synthase activation, enhanced endothelium-dependent vascular relaxation, and improved vascularization of adipose tissue, skeletal muscle, and heart. Mechanistically, we identified a novel interplay of CIDEC-vascular endothelial growth factor A (VEGFA)-vascular endothelial growth factor receptor 2 (VEGFR2) that reduced VEGFA and VEGFR2 degradation, thereby increasing VEGFR2 activation. Overall, our results demonstrate a protective role of endothelial CIDEC against obesity-induced metabolic and vascular dysfunction, in part, by modulation of VEGF signaling. These data suggest that CIDEC may be investigated as a potential future therapeutic target for mitigating obesity-related cardiometabolic disease.

Inhibition of coagulation factor XI attenuates inflammation in myocardial ischemia/reperfusion injury

Abstract Background Increasing evidence suggests that FXI is an attractive target for antithrombotic therapy because it reduces thrombosis without increasing bleeding risk. Patients with decreased levels of FXI are at reduced risk of cardiovascular diseases and thromboembolic events. We have already revealed that depletion of FXI inhibits the vascular coagulation-inflammatory circuit in angiotensin II-induced arterial hypertension. However, the effect of FXI depletion on cardiac inflammation and vascular function in ischemia/reperfusion (I/R) injury is unknown. Purpose Using FXI-depleted mice to investigate the role of FXI in inflammation response post cardiac I/R injury. Methods 8–12 weeks old C57BL/6J male mice were injected intraperitoneally with FXI antisense oligonucleotide (FXI ASO) or scrambled controls for a period of 2 weeks. Then we temporarily ligated the left anterior descending (LAD) for 45 minutes to induce myocardial ischemia, followed by the reperfusion for 72 hours (ischemia/reperfusion injury, IRI). Myocardial inflammation and vascular function were analyzed by flow cytometry, real-time PCR, vascular relaxation studies from isolated aortic segment in organ chamber and chemiluminescence photon counting of oxidative burst in whole blood. Results FXI ASO treatment reduced hepatic FXI mRNA levels and prolonged activated partial thromboplastin time. Compared to scrambled ASO injected mice, oxidative burst from whole blood and endothelial dysfunction were decreased in FXI ASO injected mice with IRI. Compared to control groups, depletion of FXI attenuated cardiac infiltration of CD45+CD11b+ cells, especially LyG-LyChigh monocytes and LyG+ neutrophils at day 3 in I/R injury. Furthermore, the expression levels of adhesion molecules and expression of pro-inflammatory cytokines, such as Vcam-1, CCL2, IL-6 and IL-1b, in ischemic myocardium were significantly decreased in the FXI depleted mice of I/R injury. Conclusion Our results suggest that Inhibition of FXI leads to reduction of vascular dysfunction and ROS production in I/R injury, as well as attenuation of the inflammatory response and the influx of inflammatory cells in ischemic myocardium. This indicates that FXI could be a potential target for further treatment in cardiac IRI. Funding Acknowledgement Type of funding sources: Public grant(s) – EU funding. Main funding source(s): TICARDIO project has received funding from the European Union's Horizon 2020 research and Innovation programme under the Marie Skłodowska-Curie grant agreement No 813409.