Aerobic Exercise During Advance Stage of Uncontrolled Arterial Hypertension.

Aim: To evaluate the influence of physical training on myocardial function, oxidative stress, energy metabolism, and MAPKs and NF-κB signaling pathways in spontaneously hypertensive rats (SHR), at advanced stage of arterial hypertension, which precedes heart failure development.

Methods: We studied four experimental groups: normotensive Wistar rats (W, = 27), trained W (W-EX, = 31), SHR ( = 27), and exercised SHR (SHR-EX, = 32). At 13 months old, the exercise groups underwent treadmill exercise 5 days a week for 4 months.

PDIA1 acts as master organizer of NOX1/NOX4 balance and phenotype response in vascular smooth muscle.

Changes in vascular smooth muscle cell (VSMC) phenotype underlie disease pathophysiology and are strongly regulated by NOX NADPH oxidases, with NOX1 favoring synthetic proliferative phenotype and NOX4 supporting differentiation. Growth factor-triggered NOX1 expression/activity strictly depends on the chaperone oxidoreductase protein disulfide isomerase-A1 (PDIA1). Intracellular PDIA1 is required for VSMC migration and cytoskeleton organization, while extracellular PDIA1 fine-tunes cytoskeletal mechanoadaptation and vascular remodeling.

Conserved Gene Microsynteny Unveils Functional Interaction Between Protein Disulfide Isomerase and Rho Guanine-Dissociation Inhibitor Families.

Protein disulfide isomerases (PDIs) support endoplasmic reticulum redox protein folding and cell-surface thiol-redox control of thrombosis and vascular remodeling. The family prototype PDIA1 regulates NADPH oxidase signaling and cytoskeleton organization, however the related underlying mechanisms are unclear. Here we show that genes encoding human PDIA1 and its two paralogs PDIA8 and PDIA2 are each flanked by genes encoding Rho guanine-dissociation inhibitors (GDI), known regulators of RhoGTPases/cytoskeleton.

Induction of Oxidants Distinguishes Susceptibility of Prostate Carcinoma Cell Lines to p53 Gene Transfer Mediated by an Improved Adenoviral Vector.

Previously, the authors developed an adenoviral vector, Ad-PG, where transgene expression is regulated by a p53-responsive promoter. When used to transfer the p53 cDNA, a positive feedback mechanism is established. In the present study, a critical comparison is performed between Ad-PGp53 and AdRGD-PGp53, where the RGD motif was incorporated in the adenoviral fiber protein.

Measurement of Superoxide Production and NADPH Oxidase Activity by HPLC Analysis of Dihydroethidium Oxidation.

The fluorogenic probe dihydroethidium (DHE) is widely used for detecting intracellular superoxide. DHE oxidation by superoxide generates specifically the compound 2-hydroxyethidium (2-EOH), so that 2-EOH detection confers specificity to superoxide assessment among many other reactive oxygen species. However, DHE oxidation in biological systems leads to formation of other fluorescent products, particularly ethidium, usually formed at higher quantities than 2-EOH.

Modulation of MAPK and NF-954;B Signaling Pathways by Antioxidant Therapy in Skeletal Muscle of Heart Failure Rats.

Background/aims: Although increased oxidative stress plays a role in heart failure (HF)-induced skeletal myopathy, signaling pathways involved in muscle changes and the role of antioxidant agents have been poorly addressed. We evaluated the effects of N-acetylcysteine (NAC) on intracellular signaling pathways potentially modulated by oxidative stress in soleus muscle from HF rats.

Methods And Results: Four months after surgery, rats were assigned to Sham, myocardial infarction (MI)-C (without treatment), and MI-NAC (treated with N-acetylcysteine) groups.

Amino acids trigger down-regulation of superoxide via TORC pathway in the midgut of Rhodnius prolixus.

Sensing incoming nutrients is an important and critical event for intestinal cells to sustain life of the whole organism. The TORC is a major protein complex involved in monitoring the nutritional status and is activated by elevated amino acid concentrations. An important feature of haematophagy is that huge amounts of blood are ingested in a single meal, which results in the release of large quantities of amino acids, together with the haemoglobin prosthetic group, haem, which decomposes hydroperoxides and propagates oxygen-derived free radicals.

Beneficial Effects of Physical Exercise on Functional Capacity and Skeletal Muscle Oxidative Stress in Rats with Aortic Stenosis-Induced Heart Failure.

Objective. We evaluated the influence of exercise on functional capacity, cardiac remodeling, and skeletal muscle oxidative stress, MAPK, and NF-κB pathway in rats with aortic stenosis- (AS-) induced heart failure (HF). Methods and Results.

Influence of N- acetylcysteine on oxidative stress in slow-twitch soleus muscle of heart failure rats.

Background: Chronic heart failure is characterized by decreased exercise capacity with early exacerbation of fatigue and dyspnea. Intrinsic skeletal muscle abnormalities can play a role in exercise intolerance. Causal or contributing factors responsible for muscle alterations have not been completely defined.

An interaction of renin-angiotensin and kallikrein-kinin systems contributes to vascular hypertrophy in angiotensin II-induced hypertension: in vivo and in vitro studies.

The kallikrein-kinin and renin-angiotensin systems interact at multiple levels. In the present study, we tested the hypothesis that the B1 kinin receptor (B1R) contributes to vascular hypertrophy in angiotensin II (ANG II)-induced hypertension, through a mechanism involving reactive oxygen species (ROS) generation and extracellular signal-regulated kinase (ERK1/2) activation. Male Wistar rats were infused with vehicle (control rats), 400 ng/Kg/min ANG II (ANG II rats) or 400 ng/Kg/min ANG II plus B1 receptor antagonist, 350 ng/Kg/min des-Arg(9)-Leu(8)-bradykinin (ANGII+DAL rats), via osmotic mini-pumps (14 days) or received ANG II plus losartan (10 mg/Kg, 14 days, gavage - ANG II+LOS rats).

Methods of measuring protein disulfide isomerase activity: a critical overview.

Protein disulfide isomerase is an essential redox chaperone from the endoplasmic reticulum (ER) and is responsible for correct disulfide bond formation in nascent proteins. PDI is also found in other cellular locations in the cell, particularly the cell surface. Overall, PDI contributes to ER and global cell redox homeostasis and signaling.

Time-dependent effects of training on cardiovascular control in spontaneously hypertensive rats: role for brain oxidative stress and inflammation and baroreflex sensitivity.

Baroreflex dysfunction, oxidative stress and inflammation, important hallmarks of hypertension, are attenuated by exercise training. In this study, we investigated the relationships and time-course changes of cardiovascular parameters, pro-inflammatory cytokines and pro-oxidant profiles within the hypothalamic paraventricular nucleus of the spontaneously hypertensive rats (SHR). Basal values and variability of arterial pressure and heart rate and baroreflex sensitivity were measured in trained (T, low-intensity treadmill training) and sedentary (S) SHR at weeks 0, 1, 2, 4 and 8.

Nitroglycerin drives endothelial nitric oxide synthase activation via the phosphatidylinositol 3-kinase/protein kinase B pathway.

Nitroglycerin (GTN) has been clinically used to treat angina pectoris and acute heart episodes for over 100 years. The effects of GTN have long been recognized and active research has contributed to the unraveling of numerous metabolic routes capable of converting GTN to the potent vasoactive messenger nitric oxide. Recently, the mechanism by which minute doses of GTN elicit robust pharmacological responses was revisited and eNOS activation was implicated as an important route mediating vasodilation induced by low GTN doses (1-50nM).

Antioxidant activity of uruguayan propolis. In vitro and cellular assays.

The antioxidant capacity of propolis from the southern region of Uruguay was evaluated using in vitro as well as cellular assays. Free radical scavenging capacity was assessed by ORAC, obtaining values significantly higher than those of other natural products (8000 μmol Trolox equiv/g propolis). ORAC values correlated well with total polyphenol content (determined by Folin-Ciocalteu method) and UV absorption.

Tobacco smoke induces ventricular remodeling associated with an increase in NADPH oxidase activity.

Background: Recent studies have assessed the direct effects of smoking on cardiac remodeling and function. However, the mechanisms of these alterations remain unknown. The aim of this study was to investigate de role of cardiac NADPH oxidase and antioxidant enzyme system on ventricular remodeling induced by tobacco smoke.

Protein disulfide isomerase overexpression in vascular smooth muscle cells induces spontaneous preemptive NADPH oxidase activation and Nox1 mRNA expression: effects of nitrosothiol exposure.

Mechanisms regulating NADPH oxidase remain open and include the redox chaperone protein disulfide isomerase (PDI). Here, we further investigated PDI effects on vascular NADPH oxidase. VSMC transfected with wild-type PDI (wt-PDI) or PDI mutated in all four redox cysteines (mut-PDI) enhanced (2.

Constitutive nitric oxide synthase activation is a significant route for nitroglycerin-mediated vasodilation.

The physiological effects of nitroglycerin as a potent vasodilator have long been documented. However, the molecular mechanisms by which nitroglycerin exerts its biological functions are still a matter of intense debate. Enzymatic pathways converting nitroglycerin to vasoactive compounds have been identified, but none of them seems to fully account for the reported clinical observations.

Assessment of superoxide production and NADPH oxidase activity by HPLC analysis of dihydroethidium oxidation products.

Assessment of low-level superoxide in nonphagocytic cells is crucial for assessing redox-dependent signaling pathways and the role of enzymes such as the NADPH oxidase complex. However, most superoxide probes present inherent limitations. Particularly, assessment of dihydroethidium (DHE) fluorescence is limited regarding a lack of possible quantification and simultaneous detection of its two main products: 2-hydroxyethidium, more specific for superoxide, and ethidium, which reflects H2O2-dependent pathways involving metal proteins.

Novel role of protein disulfide isomerase in the regulation of NADPH oxidase activity: pathophysiological implications in vascular diseases.

Vascular cell NADPH oxidase complexes are key sources of signaling reactive oxygen species (ROS) and contribute to disease pathophysiology. However, mechanisms that fine-tune oxidase-mediated ROS generation are incompletely understood. Besides known regulatory subunits, upstream mediators and scaffold platforms reportedly control and localize ROS generation.

Angiotensin II chronic infusion induces B1 receptor expression in aorta of rats.

We investigated whether angiotensin II infusion modulates in vivo the kinin B1 receptor expression and the mechanisms involved in this process. We also evaluated the role of the B1 receptor activation in aorta. Wistar rats received 400 ng/kg per minute of angiotensin II or saline (control rats) infusion during 14 days through an osmotic minipump.

Analysis of DHE-derived oxidation products by HPLC in the assessment of superoxide production and NADPH oxidase activity in vascular systems.

Dihydroethidium (DHE) is a widely used sensitive superoxide (O2(*-)) probe. However, DHE oxidation yields at least two fluorescent products, 2-hydroxyethidium (EOH), known to be more specific for O2(*-), and the less-specific product ethidium. We validated HPLC methods to allow quantification of DHE products in usual vascular experimental situations.

Improvement of paclitaxel therapeutic index by derivatization and association to a cholesterol-rich microemulsion: in vitro and in vivo studies.

A cholesterol-rich microemulsion or nanoparticle termed LDE concentrates in cancer tissues after injection into the bloodstream. Here the cytotoxicity, pharmacokinetics, toxicity to animals and therapeutic action of a paclitaxel lipophilic derivative associated to LDE is compared with those of the commercial paclitaxel. Results show that LDE-paclitaxel oleate is stable.

Tempol diverts peroxynitrite/carbon dioxide reactivity toward albumin and cells from protein-tyrosine nitration to protein-cysteine nitrosation.

Tempol has been shown to protect experimental animals from injuries associated with excessive nitric oxide production. In parallel, tempol decreased the levels of protein-3-nitrotyrosine in the injured tissues, suggesting that it interacted with nitric oxide-derived oxidants such as nitrogen dioxide and peroxynitrite. Relevantly, a few recent studies have shown that tempol catalytically diverts peroxynitrite/carbon dioxide reactivity toward phenol from nitration to nitrosation.

Use of a cholesterol-rich microemulsion that binds to low-density lipoprotein receptors as vehicle for etoposide.

A cholesterol-rich microemulsion (LDE) that binds to low-density lipoprotein (LDL) receptors is selectively taken up by malignant cells that overexpress those receptors and may be used as vehicle for antineoplastic agents. This study aimed to develop the association of etoposide with LDE. It was firstly observed that etoposide poorly associates with the microemulsion, therefore the experiments were performed with a lipophilic fatty acid derivative of the drug.