Search

The present study aimed to investigate the effects of mood stabilizers, specifically lithium (Li) and valproate (VPA), on mitochondrial superoxide, lipid peroxidation, and proteins involved in cell death signaling pathways in the brains of rats subjected to the ouabain-induced animal model of mania. Wistar rats received Li, VPA, or saline twice a day for 13 days. On the 7th day of treatment, the animals received a single intracerebroventricular injection of ouabain or aCSF. After the ICV injection, the treatment with mood stabilizers continued for 6 additional days. The locomotor activity of rats was measured using the open-field test. In addition, we analyzed oxidative stress parameters, specifically levels of phosphorylated p53 (pp53), BAX and Bcl-2 in the brain of rats by immunoblot. Li and VPA reversed ouabain-related hyperactivity. Ouabain decreased Bcl-2 levels and increased the oxidative stress parameters BAX and pp53 in the brains of rats. Li and VPA improved these ouabain-induced cellular dysfunctions; however, the effects of the mood stabilizers were dependent on the protein and brain region analyzed. These findings suggest that the Na(+)/K(+)-ATPase can be an important link between oxidative damage and the consequent reduction of neuronal and glial density, which are both observed in BD, and that Li and VPA exert protective effects against ouabain-induced activation of the apoptosis pathway., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

The exact mechanisms of the relationship between obesity and cardiovascular events are not yet fully understood; however, oxidative stress may be involved. Thus, the aim of the present study was to evaluate the effects of resveratrol and fish oil on catecholamine-induced mortality in obese rats. To begin with, rats were divided into five groups: (1) lean, (2) obese, (3) obese supplemented with resveratrol, (4) obese supplemented with fish oil and (5) obese supplemented with resveratrol and fish oil (n 18 rats per group), for 2 months. After supplementation, the groups were subdivided as with (n 10) and without (n 8) cardiovascular catecholaminergic stress after isoproterenol (60 mg/kg) injection. At 24 h later, the survival rate was analysed. The obese group showed lower survival rates (10 %) when compared with the lean group (70 %). On the other hand, resveratrol (50 %) and fish oil (40 %) increased the survival rate of obese rats (χ(2) test, P= 0·019). Biochemical analyses of the myocardium and aorta revealed that obese rats had higher levels of superoxide and oxidative damage to lipids and protein. This was associated with reduced superoxide dismutase and glutathione peroxidase activity in both the myocardium and aorta. The supplementation increased antioxidant enzyme activities and reduced oxidative damage. We also evaluated the nuclear factor-erythroid 2 p45-related factor 2 (Nrf2)/Kelch-like ECH-associated protein 1 antioxidant pathway. Nrf2 protein levels that were reduced in obese rats were increased by the antioxidant treatment. Taken together, these results showed that resveratrol and fish oil reduce catecholamine-induced mortality in obese rats, partly through the reduction of oxidative stress.

Background: Acute exercise increases reactive oxygen species (ROS) levels, including hydrogen peroxide (H2O2). H2O2 promotes endothelial nitric oxide synthase (eNOS) activation and phosphorylation in endothelial cells. With this in mind, the present study was designed to evaluate ex vivo eNOS phosphorylation in rat aortas incubated with H2O2 and to test this hypothesis in vivo in the aortas of rats submitted to acute exercise., Methods: For ex vivo studies, six groups of aortic tissue were formed: control, H2O2, N-acetylcysteine (NAC), LY294002, compound C, and LY294002 plus compound C. While incubation with H2O2 increased Akt, AMPK and eNOS phosphorylation, pre-incubation with NAC strongly reduced the phosphorylation of these enzymes. For in vivo studies, male Wistar rats were divided into four groups: control, cont+NAC, exercise, and exer+NAC. After a 3h swimming session, animals were decapitated and aortas were excised for biochemical and immunoblotting analysis., Results: Acute exercise increased superoxide levels and dichlorofluorescein (DCF) concentrations, and this increase was related to phosphorylation of Akt, AMPK and eNOS. On the other hand, use of NAC reduced superoxide levels and DCF concentration. Reduced superoxide levels and DCF in the exer+NAC group were associated with decreased Akt, AMPK and eNOS phosphorylation. These results appear to be connected with vascular function because VASP phosphorylation increased in acute exercise and decreased in exer+NAC., Conclusion: Our results indicate that ROS induced by acute exercise play the important role of activating eNOS, a process apparently mediated by Akt and AMPK., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

Purpose: This study evaluates the effects of the gold nanoparticle in endotoxin-induced uveitis in rats., Methods: Adult male Wistar rats were divided into five groups: saline + saline, lipopolysaccharide (LPS) + saline, LPS + prednisolone, LPS + gold salt (GS) and LPS + gold nanoparticle (GNP). Two hours after LPS administration, prednisolone acetate 1%, GS, and GNP were topically applied to both eyes of rats and repeated every 6 hours for 24 hours. After 24 hours, rats were anesthetized and aqueous humor was sampled and the irides were removed. Aqueous humor TNF-α, myeloperoxidase activity were determined. Irides oxidative damage and content of toll-like receptor 4 (TLR4) and nuclear factor-κB (NF-κB) were determined., Results: The administration of LPS-induced eye inflammatory response characterized by an increase in aqueous humor TNF-α, myeloperoxidase, and by irides oxidative damage. All these parameters were decreased by the administration of GNP. Since the inflammatory response secondary to LPS administration depends, in part, to the activation of the TLR4-NF-κB pathway we demonstrated here that a potential mechanism to explain the GNP effects was the decrease on TLR4 content and NF-κB activation., Conclusions: These findings suggest that topical GNP decreases intraocular inflammation and oxidative damage by interfering in the TLR4-NF-κB pathway.

Lithium (Li) is the main mood stabilizer and acts on multiple biochemical targets, leading to neuronal plasticity. Several clinical studies have shown that tamoxifen (TMX) - a protein kinase C (PKC) inhibitor - has been effective in treating acute mania. The present study aims to evaluate the effects of TMX on biochemical targets of Li, such as glycogen synthase kinase-3β (GSK-3β), PKC, PKA, CREB, BDNF and NGF, in the brain of rats subjected to an animal model of mania induced by d-amphetamine (d-AMPH). Wistar rats were treated with d-AMPH (2mg/kg, once a day) or saline (Sal; NaCl 0.9%, w/v), Li (47.5 mg/kg, intraperitoneally (i.p.), twice a day) or TMX (1 mg/kg i.p., twice a day) or Sal in protocols of reversion and prevention treatment. Locomotor behavior was assessed using the open-field task, and protein levels were measured by immunoblot. Li and TMX reversed and prevented d-AMPH-induced hyperactivity. Western blot showed that d-AMPH significantly increased GSK-3 and PKC levels, and decreased pGSK-3, PKA, NGF, BDNF and CREB levels in the structures analyzed. Li and TMX were able to prevent and reverse these changes induced by d-AMPH in most structures evaluated. The present study demonstrated that the PKC inhibitor modulates the alterations in the behavior, neurotrophic and apoptosis pathway induced by d-AMPH, reinforcing the need for more studies of PKC as a possible target for treatment of bipolar disorder.

The literature has associated hepatic insulin action with NAFLD. In this sense, treatments to revert steatosis and improve hepatic insulin action become important. Our group has demonstrated that inhibition of Sterol Regulatory Element Binding Proteins-1c (SREBP-1c) reverses hepatic steatosis. However, insulin signals after NAFLD reversion require better investigation. Thus, in this study, we investigated if the reversal of NAFLD by SREBP-1c inhibitor results in improvement in the hepatic insulin signal in obesity mice. After installation/achievement of diet-induced obesity and insulin resistance, Swiss mice were divided into 3 groups: i) Lean, ii) D-IHS, diet-induced hepatic steatosis [no treatment with antisense oligonucleotide (ASO)], and iii) RD-IHS, reversion of diet-induced hepatic steatosis (treated with ASO). The mice were treated with ASO SREBP-1c as previously described by our group. After ASO treatment, one set of animals was anesthetized and used for in vivo test, and another mice set was anesthetized and used for histology and Western blot analysis. Reversion of diet-induced hepatic steatosis did not change blood glucose, glucose decay constant (k(ITT)), body weight, or serum insulin levels. In addition, results showed that the protocol did not improve insulin pathway signaling, as confirmed by the absence of changes in IR, IRS1, Akt and Foxo1 phosphorylation in hepatic tissue. In parallel, no alterations were observed in proinflammatory molecules. Thus, our results suggest that the inhibition of SREBP-1c reverts steatosis, but without improving insulin hepatic resistance., (© Georg Thieme Verlag KG Stuttgart · New York.)

Aim: The dysregulation of regulatory element-binding protein-1c (SREBP-1c) is associated with hepatic steatosis. However, effects of exercise on SREBP-1c protein level in liver have not been investigated. Thus, in this study we investigated if reversion of the hepatic steatosis-induced by exercise training is related with levels of SREBP-1c., Main Methods: Mice were divided into two groups: control lean mice (CT), fed on standard rodent chow, and obese mice (HF), fed on a high-fat diet for 2months. After this period obese mice were divided in two groups: obese mice and obese mice submitted to exercise (HF+EXE). The HF+EXE group performed a running program of 50min per day, 5days per week, for 8weeks. Forty-eight hours after the last exercise session, biochemical, immunoblotting, histology and immunohistochemistry analyses were performed., Key Findings: Livers of HF mice showed increased SREBP-1c, FAS (Fatty Acid Synthase), SCD1 (Stearoyl-CoA Desaturase1) and CPT1 (Carnitine Palmitoyl Transferase1) protein levels (3.4, 5.0, 2.6 and 2.9 times, respectively), though ACC (Acetyl-CoA Carboxilase) phosphorylation dropped 4.2 times. In livers of HF+EXE, levels of SREBP-1c, FAS, SCDI and CPTI decreased 2.1, 1.9, 1.8, and 2.7 times, respectively), while ACC phosphorylation increased 3.0 times. Lower SREBP-1c protein levels after exercise were confirmed also by immunohistochemistry. Total liver lipids content was higher in HF (2.2 times) when compared to CT, and exercise training reduced it significantly (1.7 times)., Significance: Our study allows concluding that the reduction in SREBP-1c protein levels is associated with steatosis reversion induced by exercise training., (Crown Copyright © 2012. Published by Elsevier Inc. All rights reserved.)

Background: Contrast-induced nephropathy (CIN) is associated with a combination of hypoxic and toxic renal tubular damage, renal endothelial dysfunction and altered intra-renal microcirculation. Recently, sodium butyrate (SB) has been focused on since it possesses anti-inflammatory activities. Thus, based on the lack of information on the effects of SB in acute kidney injury (AKI), we investigated the possible effects of SB after CIN in rats., Methods: Wistar rats were divided into three groups: (1 sham) control, (2 MI) AKI treated with contrast medium and (3 MI + SB) AKI plus SB. Six days after contrast administration, blood and kidney were removed for the determination of creatinine, interleukin (IL)-6 levels, oxidative damage parameters and histologic analyses. Nuclear factor kappa B (NF-κB), pIκBα and vasodilator-stimulated phosphoprotein (VASP) protein content were determined by immunoblotting., Results: After 6 days, the levels of creatinine increased significantly in the MI group, and this was attenuated using SB. SB treatment was associated with a decrease on the levels of lipid peroxidation, but not the protein oxidation, and IL-6 levels, as well as tubular damage. These effects are probably mediated, in part, by a decrease on the activation of NF-κB in the kidney, but not alteration in pVASP content., Conclusions: The current experiment suggests that NF-κB induced an inflammatory response after CIN and SB could inhibit NF-κB expression protecting against CIN in rats.

Studies have shown an exacerbated increase in proinflammatory markers during and after muscle injury. In this way, interventions that reduce inflammatory activation appear to be of great interest in muscle injury therapy. Thus, the preset study evaluated the effect of low-intensity pulsed ultrasound (LIPUS) and dimethylsulfoxide (DMSO) on the proinflammatory molecules in an animal model of traumatic muscle injury. Forty-eight 3-month old male Wistar rats were divided into six groups (n = 8/group): sham; muscle injury without treatment; muscle injury and gel-saline (0.9%); muscle injury and gel-DMSO (15 mg/kg); muscle injury and LIPUS plus gel-saline; and muscle injury and LIPUS plus gel-DMSO. Two, 12, 24 and 48 h after trauma, four groups received one of the treatments described. One hour after, Western blot was performed to quantify proinflammatory protein levels. We observed greater protein levels of TNFα (3.9 times), IL-1β (3.6 times), JNK phosphorylation (4.2 times) and NFκB (3.8 times) in muscle injury group. However, the combined LIPUS with DMSO resulted in significantly lower levels of TNFα (2.2 times), IL-1β (2.1 times), JNK phosphorylation (2.4 times), and NFκB (2.1 times). The results demonstrate that LIPUS associated with DMSO gel can attenuate TNFα, IL-1β, NFκB protein levels and JNK phosphorylation in traumatic muscle injury., (Copyright © 2012 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.)

Recently, several studies have emerged suggesting a role of the intracellular survival pathways in the treatment of mood disorders. In addition, the beneficial effects of using a combination of antipsychotics and antidepressants have been shown. With this in mind, we evaluated the effects of the acute administration of fluoxetine (FLX), olanzapine (OLZ) and the combination of fluoxetine/olanzapine on the brain-derived-neurotrophic factor (BDNF), cAMP response element-binding (CREB), Protein Kinase B (PKB, Akt), B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated death promoter (BAD) in the rat brain. Adult Wistar rats received an acute injection of OLZ (3 or 6 mg/kg) and/or FLX (12.5 or 25 mg/kg), and were evaluated for Akt, BDNF, CREB, Bcl-2 and BAD protein levels in the prefrontal cortex, hippocampus and striatum. Our results showed that treatment with FLX and OLZ alone or in combination increased the Akt, CREB, BDNF, Bcl-2 and BAD levels in the prefrontal cortex, hippocampus and striatum. However, the combination of FLX and OLZ at high doses was associated with a greater increase in the levels of Akt in the prefrontal cortex, and did not have an effect on the levels of BAD in any of the brain areas that we evaluated. Finally, these findings further support the hypothesis that treatment with FLX and OLZ alone or in combination exert neuroprotective effects, and that intracellular survival pathways could be involved in the therapeutic effects of combining antipsychotic and antidepressant drugs in mood disorders., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Objective: The present study investigates the level of Sterol-regulatory element-binding proteins (SREBP-1c) and related proteins in obese mice (DIO) treated with SREBP-1c antisense oligonucleotide (ASO) to observe a reversal of steatosis., Materials and Methods: Swiss mice were fed on chow containing 61 kJ% saturated fat for 8 weeks to develop obesity. After this period, one group of animals was used to assess the molecular effects of SREBP-1c antisense oligonucleotide treatment by immunoblot analysis in a dose-response curve (0; 1.0; 2.0; 3.0; 4.0 nmol/day). After the dose (3.0 nmol/day) was determined, another group was treated for 14 days. After a period of 24 h following the last injection mice were killed and plasma and hepatic tissue were obtained to evaluate plasma triglycerides and total liver fat. Western blot was performed to evaluate SREBP-1c, FAS, SCD-1, PPARγ and CPT1 expression and AMPK[Thr172] and ACC[Ser79] phosphorylation. Livers were stained using the hematoxylin and eosin method for histological analysis., Results: Body weight, epididymal fat and glucose levels were not affected by one daily dose of ASO. However, total plasma triglycerides and total liver fat were significantly reduced. Also, this treatment inhibited SREBP-1c and reduced protein levels of a series of proteins involved in lipogenesis, including ACC, FAS and SCD-1. Moreover, mice treated with ASO presented a significant reduction in macroscopic and microscopic features of hepatic steatosis., Conclusion: Our results demonstrate that the inhibition of SREBP-1c decreased the expression of lipogenic enzymes, reducing the accumulation of triglycerides and, finally, reversing hepatic steatosis in mice.

Obesity-induced endoplasmatic reticulum (ER) stress has been demonstrated to underlie the induction of obesity-induced JNK and NF-κB activation inflammatory responses, and generation of peripheral insulin resistance. On the other hand, exercise has been used as a crucial tool in obese and diabetic patients, and may reduce inflammatory pathway stimulation. However, the ability of exercise training to reverse endoplasmatic reticulum stress in adipose and hepatic tissue in obesity has not been investigated in the literature. Here, we demonstrate that exercise training ameliorates ER stress and insulin resistance in DIO-induced rats. Rats were fed with standard rodent chow (3,948 kcal kg(-1)) or high-fat diet (5,358 kcal kg(-1)) for 2 months. After that rats were submitted to swimming training (1 h per day, 5 days for week with 5% overload of the body weight for 8 weeks). Samples from epididymal fat and liver were obtained and western blot analysis was performed. Our results showed that swimming protocol reduces pro-inflammatory molecules (JNK, IκB and NF-κB) in adipose and hepatic tissues. In addition, exercise leads to reduction in ER stress, by reducing PERK and eIF2α phosphorylation in these tissues. In parallel, an increase in insulin pathway signaling was observed, as confirmed by increases in IR, IRSs and Akt phosphorylation following exercise training in DIO rats. Thus, results suggest that exercise can reduce ER stress, improving insulin resistance in adipose and hepatic tissue.

A growing body of evidence has pointed to the N-methyl-d-aspartate (NMDA) receptor antagonists as a potential therapeutic target for the treatment of major depression. The present study investigated the possibility of synergistic interactions between antidepressant imipramine with the uncompetitive NMDA receptor antagonist ketamine. Wistar rats were acutely treated with ketamine (5 and 10mg/kg) and imipramine (10 and 20mg/kg) and then subjected to forced swimming tests. The cAMP response element bindig (CREB) and brain-derived neurotrophic factor (BDNF) protein levels and protein kinase C (PKC) and protein kinase A (PKA) phosphorylation were assessed in the prefrontal cortex, hippocampus and amygdala by imunoblot. Imipramine at the dose of 10mg/kg and ketamine at the dose of 5mg/kg did not have effect on the immobility time; however, the effect of imipramine (10 and 20mg/kg) was enhanced by both doses of ketamine. Ketamine and imipramine alone or in combination at all doses tested did not modify locomotor activity. Combined treatment with ketamine and imipramine produced stronger increases of CREB and BDNF protein levels in the prefrontal cortex, hippocampus and amygdala, and PKA phosphorylation in the hippocampus and amygdala and PKC phosphorylation in prefrontal cortex. The results described indicate that co-administration of antidepressant imipramine with ketamine may induce a more pronounced antidepressant activity than treatment with each antidepressant alone. This finding may be of particular importance in the case of drug-resistant patients and could suggest a method of obtaining significant antidepressant actions whilst limiting side effects., (Copyright © 2011 Elsevier B.V. All rights reserved.)