Adult Rat Aorta Research Articles

Greater TIMP-1 protein levels and neointimal formation represent sex-dependent cellular events limiting aortic vessel expansion in female rats.

Fragmentation/loss of the structural protein elastin represents the precipitating event translating to aortic expansion and subsequent aneurysm formation. The present study tested the hypothesis that greater protein expression of tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) and neointimal growth secondary to a reduction of medial elastin content represent sex-dependent events limiting aortic vessel expansion in females. TIMP-1 protein levels were higher in the ascending aorta of female versus male patients diagnosed with a bicuspid aortic valve (BAV). The latter paradigm was recapitulated in the aorta of adult male and female rats complemented by greater TIMP-2 expression in females. CaCl2 (0.5 M) treatment of the infrarenal aorta of adult male and female rats increased the in situ vessel diameter and expansion was significantly smaller in females despite a comparable reduction of medial elastin content. The preferential appearance of a neointimal region of the CaCl2-treated infrarenal aorta of female rats may explain in part the smaller in situ expansion and neointimal growth correlated positively with the % change of the in situ diameter. Neointimal formation was secondary to a significant increase in the density of medial/neointimal vascular smooth muscle cells (VSMCs) that re-entered the G2-M phase whereas VSMC cell cycle re-entry was attenuated in the CaCl2-treated infrarenal aorta of male rats. Thus, greater TIMP-1 expression in the aorta of female BAV patients may prevent excessive elastin fragmentation and preferential neointimal growth following CaCl2-treatment of the infrarenal aorta of female rats represents a sex-dependent biological event limiting vessel expansion secondary to a significant loss of the structural protein.

Combined Therapy with Simvastatin- and Coenzyme-Q10-Loaded Nanoparticles Upregulates the Akt-eNOS Pathway in Experimental Metabolic Syndrome.

In addition to their LDL-cholesterol-lowering effect, statins have pleiotropic beneficial effects on the cardiovascular system. However, long-term treatment with statins may be associated with serious side effects. With the aim to make statin therapy more effective, we studied the effects of simvastatin- and coenzyme-Q10-loaded polymeric nanoparticles on the lipid profile and nitric oxide (NO)/reactive oxygen species (ROS) balance in the heart and aorta of adult male obese Zucker rats. The rats were divided into an untreated group, a group treated with empty nanoparticles, and groups treated with simvastatin-, coenzyme Q10 (CoQ10)-, or a combination of simvastatin- and CoQ10-loaded nanoparticles (SIMV+CoQ10). After 6 weeks, the lipid profile in the plasma and the concentration of conjugated dienes in the liver were determined. Nitric oxide synthase (NOS) activity, Akt, endothelial NOS (eNOS), phosphorylated eNOS (p-eNOS), nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, and nuclear factor kappaB (NF-kappaB) protein expressions were measured in the heart and aorta. All simvastatin, CoQ10, and SIMV+CoQ10 treatments decreased plasma LDL levels, but only the combined SIMV+CoQ10 treatment increased NOS activity and the expression of Akt, eNOS, and p-eNOS in both the heart and the aorta. Interestingly, NADPH oxidase in the heart and NF-kappaB protein expression in the aorta were decreased by all treatments, including nanoparticles alone. In conclusion, only combined therapy with SIMV- and CoQ10-loaded nanoparticles increased NOS activity and upregulated the Akt-eNOS pathway in obese Zucker rats, which may represent a promising tool for the treatment of cardiometabolic diseases.

The Vasoactive Effect of Perivascular Adipose Tissue and Hydrogen Sulfide in Thoracic Aortas of Normotensive and Spontaneously Hypertensive Rats.

The objective of this study was to investigate the vasoregulatory role of perivascular adipose tissue (PVAT) and its mutual interaction with endogenous and exogenous H2S in the thoracic aorta (TA) of adult normotensive Wistar rats and spontaneously hypertensive rats (SHRs). In SHRs, hypertension was associated with cardiac hypertrophy and increased contractility. Regardless of the strain, PVAT revealed an anticontractile effect; however, PVAT worsened endothelial-dependent vasorelaxation. Since H2S produced by both the vascular wall and PVAT had a pro-contractile effect in SHRs, H2S decreased the sensitivity of adrenergic receptors to noradrenaline in Wistar rats. While H2S had no contribution to endothelium-dependent relaxation in Wistar rats, in SHRs, H2S produced by the vascular wall had a pro-relaxant effect. We observed a larger vasorelaxation induced by exogenous H2S donor in SHRs than in Wistar rats. Additionally, in the presence of PVAT, this effect was potentiated. We demonstrated that PVAT of the TA aggravated endothelial function in SHRs. However, H2S produced by the TA vascular wall had a pro-relaxation effect, and PVAT revealed anti-contractile activity mediated by the release of an unknown factor and potentiated the vasorelaxation induced by exogenous H2S. All these actions could represent a form of compensatory mechanism to balance impaired vascular tone regulation.

Chronic administration of minoxidil protects elastic fibers and stimulates their neosynthesis with improvement of the aorta mechanics in mice

Arterial wall elastic fibers, made of 90% elastin, are arranged into elastic lamellae which are responsible for the resilience and elastic properties of the large arteries (aorta and its proximal branches). Elastin is synthesized only in early life and adolescence mainly by the vascular smooth muscles cells (VSMC) through the cross-linking of its soluble precursor, tropoelastin. In normal aging, the elastic fibers become fragmented and the mechanical load is transferred to collagen fibers, which are 100–1000 times stiffer than elastic fibers. Minoxidil, an ATP-dependent K+ channel opener, has been shown to stimulate elastin expression in vitro, and in vivo in the aorta of male aged mice and young adult hypertensive rats. Here, we have studied the effect of a 3-month chronic oral treatment with minoxidil (120 mg/L in drinking water) on the abdominal aorta structure and function in adult (6-month-old) and aged (24-month-old) male and female mice. Our results show that minoxidil treatment preserves elastic lamellae integrity at both ages, which is accompanied by the formation of newly synthesized elastic fibers in aged mice. This leads to a generally decreased pulse pressure and a significant improvement of the arterial biomechanical properties in female mice, which present an increased distensibility and a decreased rigidity of the aorta. Our studies show that minoxidil treatment reversed some of the major adverse effects of arterial aging in mice and could be an interesting anti-arterial aging agent, also potentially usable for female-targeted therapies.

Effect of Ang III on Nuclear Factor Kappa Beta in Wistar Rat VSMCs

ObjectiveWe investigated whether angiotensin (Ang) III induces nuclear factor kappa beta (NF‐kb) phosphorylation in isolated rat vascular smooth muscle cells (VSMCs).BackgroundThe molecular mechanisms by which Ang III induces various biological effects have not been fully investigated. Most studies have shown that NF‐kb mediates Ang II inflammatory responses effects in VSMCs. Inflammation of vascular smooth muscle cells (VSMCs) is a critical action associated with cardiovascular diseases including hypertension. The role of Ang III to induce NF‐kb in VSMCs is unknown and is a focus of these studies.MethodsPrimary cultures of VSMCs were isolated from the thoracic aorta of adult Wistar rats by the explant technique. VSMCs were treated with Ang III ranging in concentration from 0.1 nM to 1000 nM for 10 minutes or with 100 nM Ang III for 1 minute to 30 minutes. The western blotting technique was used to determine the effects of the peptide on NF‐kb protein phosphorylation.ResultsConcentration studies showed that Ang III caused a dose‐dependent increase in NF‐kb protein phosphorylation. The effects of the peptide on NF‐kb phosphorylation were maximal between 10 nM and 100 nM. The peptide's effects were rapid and significant; occurring within minutes of treatment and the maximal effects on NF‐kb phosphorylation was observed by 10 minutes.ConclusionThese findings provide insight into the molecular nature of the actions of Ang III and offer possible mechanism by which Ang III physiological actions occur in VSMCs.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

TGF\u03b21 reinforces arterial aging in the vascular smooth muscle cell through a long-range regulation of the cytoskeletal stiffness

Here we report exquisitely distinct material properties of primary vascular smooth muscle (VSM) cells isolated from the thoracic aorta of adult (8 months) vs. aged (30 months) F344XBN rats. Individual VSM cells derived from the aged animals showed a tense internal network of the actin cytoskeleton (CSK), exhibiting increased stiffness (elastic) and frictional (loss) moduli than those derived from the adult animals over a wide frequency range of the imposed oscillatory deformation. This discrete mechanical response was long-lived in culture and persistent across a physiological range of matrix rigidity. Strikingly, the pro-fibrotic transforming growth factor β1 (TGFβ1) emerged as a specific modifier of age-associated VSM stiffening in vitro. TGFβ1 reinforced the mechanical phenotype of arterial aging in VSM cells on multiple time and length scales through clustering of mechanosensitive α5β1 and αvβ3 integrins. Taken together, these studies identify a novel nodal point for the long-range regulation of VSM stiffness and serve as a proof-of-concept that the broad-based inhibition of TGFβ1 expression, or TGFβ1 signal transduction in VSM, may be a useful therapeutic approach to mitigate the pathologic progression of central arterial wall stiffening associated with aging.

Novel high-strength, low-alloys Zn-Mg (< 0.1 wt% Mg) and their arterial biodegradation

It is still an open challenge to find a biodegradable metallic material exhibiting sufficient mechanical properties and degradation behavior to serve as an arterial stent. In this study, Zn-Mg alloys of 0.002 (Zn-002Mg), 0.005 (Zn-005Mg) and 0.08wt% Mg (Zn-08Mg) content were cast, extruded and drawn to 0.25mm diameter, and evaluated as potential biodegradable stent materials. Structural analysis confirmed formation of Mg2Zn11 intermetallic in all three alloys with the average grain size decreasing with increasing Mg content. Tensile testing, fractography analysis and micro hardness measurements showed the best integration of strength, ductility and hardness for the Zn-08Mg alloy. Yield strength, tensile strength, and elongation to failure values of >200–300MPa, >300–400MPa, and >30% respectively, were recorded for Zn-08Mg. This metal appears to be the first formulated biodegradable material that satisfies benchmark values desirable for endovascular stenting. Unfortunately, the alloy reveals signs of age hardening and strain rate sensitivity, which need to be addressed before using this metal for stenting. The explants of Zn-08Mg alloy residing in the abdominal aorta of adult male Sprague-Dawley rats for 1.5, 3, 4.5, 6 and 11months demonstrated similar, yet slightly elevated inflammation and neointimal activation for the alloy relative to what was recently reported for pure zinc.

Postnatal overnutrition affects metabolic and vascular function reflected by physiological and histological changes in the aorta of adult Wistar rats

ABSTRACTRigorous nutritional care during early life leads to healthy adulthood. Cardiovascular and metabolic disorders, the most prevalent clinical challenges worldwide, are epidemiologically linked to poor nutritional habits throughout life. We aimed to understand whether postnatal overnutrition (PO) initiated during lactation affects metabolic markers and vascular function later in life. To test this hypothetical effect, we studied a PO Wistar rat model based on adjusting litter size at the third day of age to three pups and eight for the control group (C). Systemic parameters such as body weight and food intake were significantly increased in adult rats, measured up to 36 weeks. Moreover, fat mass, triglycerides, insulin and systolic blood pressure were all significantly increased in the PO group. Furthermore, we assessed whether these alterations would affect morphological and functional parameters in isolated vessels. Consistent with systemic alterations of the vasculature, contraction of thoracic aortic rings, determined by dose-response curves to norepinephrine (NE), was significantly reduced in PO rats. Histological stains revealed that the relative area of collagen was higher and the elastic fiber density was lower in the distal rings of PO rats. Altogether, our results highlight the critical importance of having a healthy neonatal nutrition to prevent harmful metabolic and vascular alterations during adulthood.

Cilostazol enhances atorvastatin-induced vasodilation of female rat aorta during aging

Statins have cholesterol-independent effects including an increased vascular nitric oxide activity and are commonly used by patients with cardiovascular disease. Such patients frequently have cardiovascular diseases, which may be treated with cilostazol, a platelet aggregation inhibitor. This study was designed to investigate whether combined use of cilostazol would increase the inhibitory effect of statin on vascular smooth muscle and how maturation would affect these responses. Female Wistar rats, aged 3-4 months (young) and 14-15 months (adult), were sacrificed by cervical dislocation and the thoracic aorta was dissected and cut into 3- to 4-mm-long rings. The rings were mounted under a resting tension of 1g in a 20-ml organ bath filled with Krebs-Henseleit solution. Rings were precontracted with phenylephrine (10-6M), and the presence of endothelium was confirmed with acetylcholine (10-6M). Then, the concentration-response curves were obtained for atorvastatin alone (10-10 to 3 × 10-4M; control) and in the presence of cilostazol (10-6M) in young and adult rat aortas. This experimental protocol was also carried out in aorta rings, which had been pretreated with NG-nitro-l-arginine methyl ester (l-NAME, 10-4M). Atorvastatin induced concentration-dependent relaxations in young and adult rat thoracic aorta rings precontracted with phenylephrine. The pIC50 value of atorvastatin was significantly decreased in adult rat aortas. In addition, pretreatment of aortas with cilostazol enhanced the potency of atorvastatin in both young and adult aortas. Incubation with l-NAME did not completely eliminate the relaxations to atorvastatin in the presence of cilostazol. These results suggest that combined application of cilostazol with atorvastatin was significantly more potent than atorvastatin alone. Combined drug therapy may be efficacious in delaying the occurrence of cardiovascular events.

Vascular scaffolds with enhanced antioxidant activity inhibit graft calcification.

There is a need for off-the-shelf, small-diameter vascular grafts that are safe and exhibit high long-term patency. Decellularized tissues can potentially be used as vascular grafts; however, thrombogenic and unpredictable remodeling properties such as intimal hyperplasia and calcification are concerns that hinder their clinical use. The objective of this study was to investigate the long-term function and remodeling of extracellular matrix (ECM)-based vascular grafts composited with antioxidant poly(1, 8-octamethylene-citrate-co-cysteine) (POCC) with or without immobilized heparin. Rat aortas were decellularized to create the following vascular grafts: 1) ECM hybridized with POCC (Poly-ECM), 2) Poly-ECM subsequently functionalized with heparin (Poly-ECM-Hep), and 3) non-modified vascular ECM. Grafts were evaluated as interposition grafts in the abdominal aorta of adult rats at three months. All grafts displayed antioxidant activity, were patent, and exhibited minimal intramural cell infiltration with varying degrees of calcification. Areas of calcification co-localized with osteochondrogenic differentiation of vascular smooth muscle cells, lipid peroxidation, oxidized DNA damage, and cell apoptosis, suggesting an important role for oxidative stress in the calcification of grafts. The extent of calcification within grafts was inversely proportional to their antioxidant activity: Poly-ECM-Hep>ECM>Poly-ECM. The incorporation of antioxidants into vascular grafts may be a viable strategy to inhibit degenerative changes.

Angiogenic potency evaluation of cell therapy candidates by a novel application of the in vitro aortic ring assay

BackgroundDue to limitations of current angiogenesis assays, we aimed to develop a novel application of the rat aortic ring assay to assess the angiogenic potential of mesenchymal stromal cells (MSCs). First-trimester human umbilical cord-derived perivascular cells (FTM HUCPVCs) have multipotent characteristics and previously demonstrated angiogenic potential. We compared the effect of this young source of MSCs and adult bone marrow stromal cells (BMSCs) on ex vivo aortic endothelial network formation.MethodsThoracic segments of adult rat aortas were isolated, sectioned and embedded into Matrigel™. Fluorophore-labeled FTM HUCPVC lines and BMSCs (N = 3) were cocultured with developing endothelial networks (day 0). MSC integration, tube formation and endothelial network growth were monitored daily using phase-contrast and fluorescence microscopy. Quantification of endothelial networks was performed using ImageJ network analysis software on day 5 of coculture.ResultsFTM HUCPVCs from two umbilical cord samples migrated toward and integrated with developing aortic ring tubular networks while displaying elongated morphologies (day 1). In contrast, BMSCs did not show targeted migration and maintained spherical morphologies with limited physical interactions. Within 1 week of coculture, FTM HUCPVC lines contributed to significantly greater radial network growth and network loop formation when compared to BMSCs and untreated networks.ConclusionsWe have developed a novel potency assay to assess the angiogenic potential of cell therapy candidates. Favorable properties of FTM HUCPVCs over BMSCs that we observed with this assay and which merit further study include chemotaxis, affinity for developing vasculature, and physical supportive interactions contributing to the development of endothelial networks.

Chronic Treatment with Minoxidil Induces Elastic Fiber Neosynthesis and Functional Improvement in the Aorta of Aged Mice.

Normal arterial aging processes involve vascular cell dysfunction associated with wall stiffening, the latter being due to progressive elastin and elastic fiber degradation, and elastin and collagen cross-linking by advanced glycation end products (AGEs). These processes progressively lead to cardiovascular dysfunction during aging. Elastin is only synthesized during late gestation and childhood, and further degradation occurring throughout adulthood cannot be physiologically compensated by replacement of altered material. However, the ATP-dependent K+ channel opener minoxidil has been shown to stimulate elastin expression in vitro and in vivo in the aorta of young adult rats. Therefore, we have studied the effect of a 10-week chronic oral treatment with minoxidil (120 mg/L in drinking water) on the aortic structure and function in aged 24-month-old mice. Minoxidil treatment increased tropoelastin, fibulin-5, and lysyl-oxidase messenger RNA levels, reinduced a moderate expression of elastin, and lowered the levels of AGE-related molecules. This was accompanied by the formation of newly synthesized elastic fibers, which had diverse orientations in the wall. A decrease in the glycation capacity of aortic elastin was also produced by minoxidil treatment. The ascending aorta also underwent a minoxidil-induced increase in diameter and decrease in wall thickness, which partly reversed the age-associated thickening and returned the wall thickness value and strain-stress relation closer to those of younger adult animals. In conclusion, our results suggest that minoxidil presents an interesting potential for arterial remodeling in an antiaging perspective, even when treating already aged animals.

Suppressive effect of epigallocatechin-3-O-gallate on endoglin molecular regulation in myocardial fibrosis in vitro and in vivo.

Epigallocatechin‐3‐O‐gallate (EGCG), derived from green tea, has been studied extensively because of its diverse physiological and pharmacological properties. This study evaluates the protective effect of EGCG on angiotensin II (Ang II)‐induced endoglin expression in vitro and in vivo. Cardiac fibroblasts (CFs) from the thoracic aorta of adult Wistar rats were cultured and induced with Ang II. Western blotting, Northern blotting, real‐time PCR and promoter activity assay were performed. Ang II increased endoglin expression significantly as compared with control cells. The specific extracellular signal‐regulated kinase inhibitor SP600125 (JNK inhibitor), EGCG (100 μM) and c‐Jun N‐terminal kinase (JNK) siRNA attenuated endoglin proteins following Ang II induction. In addition, pre‐treated Ang II‐induced endoglin with EGCG diminished the binding activity of AP‐1 by electrophoretic mobility shift assay. Moreover, the luciferase assay results revealed that EGCG suppressed the endoglin promoter activity in Ang II‐induced CFs by AP‐1 binding. Finally, EGCG and the JNK inhibitor (SP600125) were found to have attenuated endoglin expression significantly in Ang II‐induced CFs, as determined through confocal microscopy. Following in vivo acute myocardial infarction (AMI)‐related myocardial fibrosis study, as well as immunohistochemical and confocal analyses, after treatment with endoglin siRNA and EGCG (50 mg/kg), the area of myocardial fibrosis reduced by 53.4% and 64.5% and attenuated the left ventricular end‐diastolic and systolic dimensions, and friction shortening in hemodynamic monitor. In conclusion, epigallocatechin‐3‐O‐gallate (EGCG) attenuated the endoglin expression and myocardial fibrosis by anti‐inflammatory effect in vitro and in vivo, the novel suppressive effect was mediated through JNK/AP‐1 pathway.

Aqueous extract of garlic (Allium sativum) administration alleviates high salt diet-induced changes in the aorta of adult Wistar rats: a morphological and morphometric study

Objectives: This study was designed to determine the morphometric and histological changes of the wall of the thoracic aorta in high salt-fed adult Wistar rats and the possible ameliorative effects of aqueous extract of garlic (Allium sativum). Methods: Twenty-five healthy female Wistar rats weighing 130–180 g were randomly assigned into five groups of five rats each (Groups A, B, C, D and E). Rats in Group A were fed with standard laboratory pellets, while Groups B, C, D and E were fed on the high-salt diet for five weeks. Thereafter, daily administration of 50 mg/kg, 100 mg/kg and 150 mg/kg of the garlic extract were giving orally to Groups C, D and E, respectively for 3 weeks while rats in Groups A and B were administered distilled water. The thoracic part of descending aorta at the level of (T6–T7) was excised for histological studies. Paraffin sections were stained with haematoxylin and eosin, Masson’s trichrome and Verhoeff-Van Gieson stains. One-way ANOVA was used to analyze data, followed by Student-Newman-Keuls (SNK) test for multiple comparisons. Results: High salt diet causes significant histomorphological changes on aorta of rats as evidenced by increase in tunica intima, media and adventitia of the aortic wall and decrease in luminal diameter; these findings were reversed by aqueous garlic extract administration. Conclusion: High salt diet increased the thickness of aortic wall and decreased luminal diameter which were significantly reversed by oral administration of garlic extract. Keywords: aorta; garlic; heart; high salt-fed

The effect of omega- 3 polyunsaturated fatty acids on endothelial tight junction occludin expression in rat aorta during lipopolysaccharide-induced inflammation.

Occludin is essential for proper assembly of tight junctions (TJs) which regulate paracellular endothelial permeability. Omega-3 polyunsaturated fatty acids (Ω-3 PUFA) protect endothelial barrier function against injury. We examined anti-inflammatory effect of Ω-3 PUFA intake (30 mg/kg/day for 10 days) on expression and location of occludin in the aorta of adult Wistar rats after a single dose of bacterial lipopolysaccharide (LPS, Escherichia coli, 1 mg/kg). The ultrastructure of TJs after LPS administration was also investigated. We measured plasma levels of C-reactive protein (CRP), Malondialdehyde (MDA) and CD68 expression and determined the total activity of NO synthase (NOS) in the aortic tissue. LPS induced a significant decrease of occludin expression accompanied by structural alterations of TJs. Levels of CRP, MDA, CD68 and NOS activity were elevated after LPS injection compared to controls indicating presence of moderate inflammation. Ω-3 PUFA supplementation did not affect occludin expression in treated inflammatory group. However they reduced CRP and MDA concentration and CD68 expression, but conversely, they increased NOS activity compared to inflammatory group. Our results indicate that a single dose of LPS could have a long-term impact on occludin expression and thus contribute to endothelial barrier dysfunction. 10-day administration of Ω-3 PUFA had partial anti-inflammatory effects on health of rats without any effect on occludin expression.

Effect of Angiotensin III on ERK1/2 and p38 mitogen activated protein (MAP) kinases in Wistar rat VSMCs

Objective: We investigated whether angiotensin (Ang) III induces ERK1/2 and p38 mitogen activated protein (MAP) kinases protein phosphorylation in isolated rat vascular smooth muscle cells (VSMCs). Background The molecular mechanisms by which Ang III induces various biological effects have not been fully investigated. Most studies have shown that MAP kinases mediate Ang II apoptosis and growth promoting effects in VSMCs.Moreover, Ang II induces vascular remodeling in these cells leading to increases in blood pressure. MAP kinases regulate or induce two crucial actions in VSMCs, proliferation and migration, which are associated with atherosclerosis and restenosis. Methods: Primary cultures of VSMCs were isolated from the thoracic aorta of adult Wistar rats by the explant technique. VSMCs were treated with Ang III ranging in concentration from 0.1 nM to 1000 nM for 10 minutes or with 100 nM Ang III for 1 minute to 30 minutes. Western blotting technique was used to determine whether Ang III induces ERK1/2 and p38 MAP kinases protein phosphorylation. Results: Concentration studies showed that Ang III caused a dose-dependent increase in ERK1/2 and p38 MAP kinases protein phosphorylation. The effects of Ang III on both MAP kinases phosphorylation were maximal between 10 nM and 100 nM concentrations. The peptide effects were rapid and significant, occurring within minutes of treatment and the maximal effects on MAP kinases phosphorylation was observed by 10 min. Conclusion These findings provide insight into the molecular nature of the actions of Ang III and offer possible mechanism by which Ang III physiological and possibly pathological actions occur in VSMCs.

Proteomic analysis identifies cytoskeleton-interacting proteins as major downstream targets of altered folate status in the aorta of adult rat.

Mild folate deficiency and subsequently elevated plasma level of homocysteine are associated with an increased risk for vascular diseases in adults. Conversely, high intakes of folic acid (FA) may have beneficial effects on vascular function, presumably in part through homocysteine lowering. However, these effects have not yet been translated in terms of prevention or treatment of vascular pathologies. Besides, the complex biologic perturbation induced by variations of the folate supply is still not fully deciphered. We thus carried out a proteomic analysis of the aorta of adult rats after a dietary FA depletion or supplementation. Nine month-old rats were fed a FA-depleted, FA-supplemented or control diet for 8 weeks. Total proteins from adventitia-free aortas were separated by 2DE and differentially expressed proteins were identified by MS. FA depletion or supplementation resulted in significantly changed abundance of 29 spots (p < 0.05), of which 20 proteins were identified. Bioinformatic analysis revealed that most of these proteins are involved in cytoskeleton-related processes important to cell function/maintenance, assembly/organization, and movement. Our proteomic study supports that expression of proteins essential to vascular structure and, presumably, function is modulated by high intake as well as deprivation of FA.

ACUTE KIDNEY INJURY DECREASED ENDOGENOUS HYDROGEN SULFIDE PRODUCTION AND INCREASED CYTOKINE EXPRESSION: IMPACT ON CARDIOVASCULAR SYSTEM

BACKGROUND: In some pathologic circumstances (e.g., septicemia) nitric oxide (NO) synthesis is higher and it is implicated in lowering of the blood pressure that usually is less responsive to conventional therapy with adrenaline and vasopressin. Thus, new specific therapeutic approaches using high affinity NO scavengers are of great relevance. Accordingly, some new ruthenium compounds with this putative property were synthesized. The aim of this work was to evaluate the NO scavenging activity of those compounds. METHODS: Aorta rings obtained from the thoracic aorta of adult male Wistar rats were suspended under 60% of maximal tension in an organ bath, containing 15 mL of Krebs-Henseleit solution (36.5 0.1oC, pH 7.2-7.4, gassed with 95% O2:5% CO2). After 60 min stabilization period, maximum contraction of aortic rings was obtained in response to noradrenaline. After that, acetylcholine was added in order to obtain maximal relaxation. Cumulative concentration-response curves were obtained to the compounds: trans-[Ru(NH3)4(SO4)(4-picoline)](BF4) (Ru-pic); trans-[Ru(NH3)4 (SO4) (nicotinamida)](BF4) (Ru-ina); trans-[Ru(NH3)4(SO4) (isonicotina mide)] (BF4) (Ru-isn); [Ru(NH3)5Cl]Cl2 (Ru-Cl); [Ru(edta)Cl] (RuEDTA); cis-[Ru(NH3)4oxalato](TFMS)3 (Ru-cis-Ox); cis[Ru(NH3)4(H2O)2 (TFMS)3 (Ru-cis-aquo) and trans [Ru(NH3)5(H2O)(TFMS)3 (Ru-trans-aquo). The same procedure was performed in the presence of L-NAME, an inhibitor of nitric oxide synthase. Control rings were not exposed to any ruthenium compound. RESULTS: The mean sem of the tension developed by the tissues following exposition to noradrenaline was 1.94 0.17 gf. Acetylcholine reduced the developed tension to 0.17 0.04 gf. In the presence of the all Ru-compounds, the developed tensions (gf) were: 1.68 0.19 (Ru-pic; n1⁄45); 1.43 0.15 (Ru-isn; n1⁄45); 1.47 0.16 (Ru-ina; n1⁄45); 1.74 0.13 (Ru-EDTA; n1⁄45); 2.93 0.24 (Ru-Cl; n1⁄45); 2.85 0.07 (Ru-cis-Ox; n1⁄45); 3.08 0.15 (Ru-cis-aquo; n1⁄45); 3.12 0.12 (Ru-trans-aquo; n1⁄45); [p<0.05 compared to control, Student t test]. All the analyzed compounds were able to cancel the effect of acetylcholine and had similar potencies (pD2; mean sem): 5.60 0.18 (Ru-pic); 5.34 0.25 (Ru-isn); 5.40 0.27 (Ru-ina); 5.48 0.23 (Ru-Cl); 6.45 0.39 (Ru-EDTA); 5.19 0.30 (Ru-cis-Ox); 5.59 0.24 (Ru-cis-aquo); 5.03 0.37 (Ru-trans-aquo). None of the effects of acetylcholine or compounds were observed when they were tested in the presence of L-NAME. CONCLUSION: The data suggested that all compounds were able to scavenge NO in rat aortic rings and to restore the vascular tone.

Effect of glimepiride on the aorta of adult albino rats after induction of diabetes mellitus

Effect of glimepiride on the aorta of adult albino rats after induction of diabetes mellitus

Nestin downregulation in rat vascular smooth muscle cells represents an early marker of vascular disease in experimental type I diabetes.

BackgroundNestin was reported to directly contribute to cell proliferation and the intermediate filament protein was detected in vascular smooth muscle cells. In experimental type I diabetes, nestin downregulation in the heart was identified as an incipient pathophysiological event. The following study tested the hypothesis that dysregulation of nestin expression in vascular smooth muscle cells represented an early event of vascular disease in experimental type I diabetes.Methods/ResultsIn the carotid artery and aorta of adult male Sprague-Dawley rats, a subpopulation of vascular smooth muscle cells co-expressed nestin and was actively involved in the cell cycle as reflected by the co-staining of nuclear phosphohistone-3. The infection of aortic vascular smooth muscle cells with a lentivirus containing a shRNAmir directed against nestin significantly reduced protein expression and concomitantly attenuated basal DNA synthesis. Two weeks following injection of adult male Sprague-Dawley rats with streptozotocin, the endothelial response of aortic rings to acetylcholine, vascular morphology and the total density of vascular smooth muscle cells in the vasculature of type I diabetic rats were similar to normal rats. By contrast, nestin protein levels and the density of nestin(+)/phosphohistone-3(+)-vascular smooth muscle cells were significantly reduced in type I diabetic rats. The in vivo observations were recapitulated in vitro as exposure of vascular smooth muscle cells to 30 mM D-glucose inhibited DNA synthesis and concomitantly reduced nestin protein expression.ConclusionsHyperglycaemia-mediated nestin downregulation and the concomitant reduction of cycling vascular smooth muscle cells represent early markers of vascular disease in experimental type I diabetes.Electronic supplementary materialThe online version of this article (doi:10.1186/s12933-014-0119-6) contains supplementary material, which is available to authorized users.