Macrophage migration inhibitory factor in the nucleus of solitary tract decreases blood pressure in SHRs

Aims The macrophage migration inhibitory factor (MIF) is an intracellular inhibitor of the central nervous system actions of angiotensin II on blood pressure. Considering that angiotensin II actions at the nucleus of the solitary tract are important for the maintenance of hypertension in spontaneously hypertensive rats (SHRs), we tested if increased MIF expression in the nucleus of the solitary tract of SHR alters the baseline high blood pressure in these rats.Methods and resultsEight-week-old SHRs or normotensive rats were microinjected with the vector AAV2-CBA-MIF into the nucleus of the solitary tract, resulting in MIF expression predominantly in neurons. Rats also underwent recordings of the mean arterial blood pressure (MAP) and heart rate (via telemetry devices implanted in the abdominal aorta), cardiac- and baroreflex function. Injections of AAV2-CBA-MIF into the nucleus of the solitary tract of SHRs produced significant decreases in the MAP, ranging from 10 to 20 mmHg, compared with age-matched SHRs that had received identical microinjections of the control vector AAV2-CBA-eGFP. This lowered MAP in SHRs was maintained through the end of the experiment at 31 days, and was associated with an improvement in baroreflex function to values observed in normotensive rats. In contrast to SHRs, similar increased MIF expression in the nucleus of the solitary tract of normotensive rats produced no changes in baseline MAP and baroreflex function.ConclusionThese results indicate that an increased expression of MIF within the nucleus of the solitary tract neurons of SHRs lowers blood pressure and restores baroreflex function. © 2012 Published on behalf of the European Society of Cardiology. All rights reserved.

Infliximab prevents increased systolic blood pressure and upregulates the AKT/eNOS pathway in the aorta of spontaneously hypertensive rats

High systolic blood pressure caused by endothelial dysfunction is a comorbidity of metabolic syndrome that is mediated by local inflammatory signals. Insulin-induced vasorelaxation due to endothelial nitric oxide synthase (eNOS) activation is highly dependent on the activation of the upstream insulin-stimulated serine/threonine kinase (AKT) and is severely impaired in obese, hypertensive rodents and humans. Neutralisation of circulating tumor necrosis factor-α (TNFα) with infliximab improves glucose homeostasis, but the consequences of this pharmacological strategy on systolic blood pressure and eNOS activation are unknown. To address this issue, we assessed the temporal changes in the systolic pressure of spontaneously hypertensive rats (SHR) treated with infliximab. We also assessed the activation of critical proteins that mediate insulin activity and TNFα-mediated insulin resistance in the aorta and cardiac left ventricle. Our data demonstrate that infliximab prevents the upregulation of both systolic pressure and left ventricle hypertrophy in SHR. These effects paralleled an increase in AKT/eNOS phosphorylation and a reduction in the phosphorylation of inhibitor of nuclear factor-κB (Iκβ) and c-Jun N-terminal kinase (JNK) in the aorta. Overall, our study revealed the cardiovascular benefits of infliximab in SHR. In addition, the present findings further suggested that the reduction of systolic pressure and left ventricle hypertrophy by infliximab are secondary effects to the reduction of endothelial inflammation and the recovery of AKT/eNOS pathway activation. © 2012 Elsevier B.V.

Apocynin: Chemical and biophysical properties of a NADPH oxidase inhibitor

Apocynin is the most employed inhibitor of NADPH oxidase (NOX), a multienzymatic complex capable of catalyzing the one-electron reduction of molecular oxygen to the superoxide anion. Despite controversies about its selectivity, apocynin has been used as one of the most promising drugs in experimental models of inflammatory and neurodegenerative diseases. Here, we aimed to study the chemical and biophysical properties of apocynin. The oxidation potential was determined by cyclic voltammetry (Epa = 0.76V), the hydrophobicity index was calculated (logP = 0.83) and the molar absorption coefficient was determined (ε275nm = 1.1 × 104 M-1 cm-1). Apocynin was a weak free radical scavenger (as measured using the DPPH, peroxyl radical and nitric oxide assays) when compared to protocatechuic acid, used here as a reference antioxidant. On the other hand, apocynin was more effective than protocatechuic acid as scavenger of the non-radical species hypochlorous acid. Apocynin reacted promptly with the non-radical reactive species H2O2 only in the presence of peroxidase. This finding is relevant, since it represents a new pathway for depleting H2O2 in cellular experimental models, besides the direct inhibition of NADPH oxidase. This could be relevant for its application as an inhibitor of NOX4, since this isoform produces H 2O2 and not superoxide anion. The binding parameters calculated by fluorescence quenching showed that apocynin binds to human serum albumin (HSA) with a binding affinity of 2.19 × 104 M -1. The association did not alter the secondary and tertiary structure of HSA, as verified by synchronous fluorescence and circular dichroism. The displacement of fluorescent probes suggested that apocynin binds to site I and site II of HSA. Considering the current biomedical applications of this phytochemical, the dissemination of these chemical and biophysical properties can be very helpful for scientists and physicians interested in the use of apocynin.

Low level laser therapy increases angiogenesis in a model of ischemic skin flap in rats mediated by VEGF, HIF-1α and MMP-2

It is known that low level laser therapy is able to improve skin flap viability by increasing angiogenesis. However, the mechanism for new blood vessel formation is not completely understood. Here, we investigated the effects of 660 nm and 780 nm lasers at fluences of 30 and 40 J/cm2 on three important mediators activated during angiogenesis. Sixty male Wistar rats were used and randomly divided into five groups with twelve animals each. Groups were distributed as follows: skin flap surgery non-irradiated group as a control; skin flap surgery irradiated with 660 nm laser at a fluence of 30 or 40 J/cm2 and skin flap surgery irradiated with 780 nm laser at a fluence of 30 or 40 J/cm2. The random skin flap was performed measuring 10 × 4 cm, with a plastic sheet interposed between the flap and the donor site. Laser irradiation was performed on 24 points covering the flap and surrounding skin immediately after the surgery and for 7 consecutive days thereafter. Tissues were collected, and the number of vessels, angiogenesis markers (vascular endothelial growth factor, VEGF and hypoxia inducible factor, HIF-1α) and a tissue remodeling marker (matrix metalloproteinase, MMP-2) were analyzed. LLLT increased an angiogenesis, HIF-1α and VEGF expression and decrease MMP-2 activity. These phenomena were dependent on the fluences, and wavelengths used. In this study we showed that LLLT may improve the healing of skin flaps by enhancing the amount of new vessels formed in the tissue. Both 660 nm and 780 nm lasers were able to modulate VEGF secretion, MMP-2 activity and HIF-1α expression in a dose dependent manner. © 2013 Published by Elsevier B.V.

Subcutaneous tissue reaction and cytotoxicity of polyvinylidene fluoride and polyvinylidene fluoride-trifluoroethylene blends associated with natural polymers

Cytotoxicity and subcutaneous tissue reaction of innovative blends composed by polyvinylidene fluoride and polyvinylidene fluoride-trifluoroethylene associated with natural polymers (natural rubber and native starch) forming membranes were evaluated, aiming its applications associated with bone regeneration. Cytotoxicity was evaluated in mouse fibroblasts culture cells (NIH3T3) using trypan blue staining. Tissue response was in vivo evaluated by subcutaneous implantation of materials in rats, taking into account the presence of necrosis and connective tissue capsule around implanted materials after 7, 14, 21, 28, 35, 60, and 100 days of surgery. The pattern of inflammation was evaluated by histomorphometry of the inflammatory cells. Chemical and morphological changes of implanted materials after 60 and 100 days were evaluated by Fourier transform infrared (FTIR) absorption spectroscopy and scanning electron microscopy (SEM) images. Cytotoxicity tests indicated a good tolerance of the cells to the biomaterial. The in vivo tissue response of all studied materials showed normal inflammatory pattern, characterized by a reduction of polymorphonuclear leukocytes and an increase in mononuclear leukocytes over the time (p < 0.05 Kruskal-Wallis). On day 60, microscopic analysis showed regression of the chronic inflammatory process around all materials. FTIR showed no changes in chemical composition of materials due to implantation, whereas SEM demonstrated the delivery of starch in the medium. Therefore, the results of the tests performed in vitro and in vivo show that the innovative blends can further be used as biomaterials. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 101B: 1284-1293, 2013. Copyright © 2013 Wiley Periodicals, Inc.

The effect of dimethyl sulfoxide (DMSO) on dentin bonding and nanoleakage of etch-and-rinse adhesives

Objective The objective was to examine the effect of a solvent dimethyl sulfoxide (DMSO) on resin-dentin bond durability, as well as potential functional mechanisms behind the effect. Methods Microtensile bond strength (μTBS) was evaluated in extracted human teeth in two separate experiments. Dentin specimens were acid-etched and assigned to pre-treatment with 0.5 mM (0.004%) DMSO as additional primer for 30 s and to controls with water pre-treatment. Two-step etch-and-rinse adhesive (Scotchbond 1XT, 3M ESPE) was applied and resin composite build-ups were created. Specimens were immediately tested for μTBS or stored in artificial saliva for 6 and 12 months prior to testing. Additional immediate and 6-month specimens were examined for interfacial nanoleakage analysis under SEM. Matrix metalloproteinase (MMP) inhibition by DMSO was examined with gelatin zymography. Demineralized dentin disks were incubated in 100% DMSO to observe the optical clearing effect. Results The use of 0.5 mM DMSO had no effect on immediate bond strength or nanoleakage. In controls, μTBS decreased significantly after storage, but increased significantly in DMSO-treated group. The control group had significantly lower μTBS than DMSO-group after 6 and 12 months. DMSO also eliminated the increase in nanoleakage seen in controls. 5% and higher DMSO concentrations significantly inhibited the gelatinases. DMSO induced optical clearing effect demonstrating collagen dissociation. Significance DMSO as a solvent may be useful in improving the preservation of long-term dentin-adhesive bond strength. The effect may relate to dentinal enzyme inhibition or improved wetting of collagen by adhesives. The collagen dissociation required much higher DMSO concentrations than the 0.5 mM DMSO used for bonding. © 2013 Academy of Dental Materials.

Alterações morfológicas, apoptose e expressão de metaloproteinases no tecido laminar de equinos submetidos à obstrução intestinal experimental: efeitos da hidrocortisona

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A dehydrorotenoid produced by callus tissue culture and wild plant roots of Boerhaavia coccinea

“Um desidro-rotenóide produzido por cultura de calos e por raízes de plantas silvestres de Boerhaavia coccinea”. Cultura de calos foram estabelecidos de folhas e galhos finos de plântula de B. coccinea produzida in vitro e analisada para isofl avonóide. A quantificação do 6,9,11-triidroxi-6a,12a-desidro-rotenóide isolado das raízes de B. coccinea P Miller, coletada em seu habitat natural, e do mesmo rotenóide produzido na cultura de células estão descritos neste artigo. A análise rotineira em CLAE mostrou que a cultura de calos produziu o mesmo isoflavonóide encontrado nas raízes da planta do campo. A quantidade do metabólito secundário produzido in vitro foi de 955.35

Efeitos da combinação do fator de crescimento de fibroblastos básico e fator de transformação de crescimento beta na proliferação, expressão de genes para colágeno tipos I e III, metaloproteases-1 e -2 e TIMPs 1,2 e 3, e na modulação da síntese destes próprios fatores de crescimento pelas células do ligamento periodontal de humanos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influência da atividade das mataloproteinases 2 e 9 na diminuiçao o colágeno tipo I miocárdico em ratos obesos

Pós-graduação em Fisiopatologia em Clínica Médica - FMB

Wettability of chlorhexidine treated non-carious and caries-affected dentine

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The effect of a minor constituent of essential oil from Citrus aurantium: The role of beta-myrcene in preventing peptic ulcer disease

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Obesity Preserves Myocardial Function During Blockade of the Glycolytic Pathway

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The Th17 pathway in the peripheral lung microenvironment interacts with expression of collagen V in the late state of experimental pulmonary fibrosis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Identification of Corynebacterium spp. isolated from bovine intramammary infections by matrix-assisted laser desorption ionization-time of flight mass spectrometry

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)