Intrauterine Undernourishment Alters TH1/TH2 Cytokine Balance and Attenuates Lung Allergic Inflammation in Wistar Rats

IL-4 produced by Th2 cells can block cytokine production by Th1 cells, and Th1 IFN-gamma is known to counterregulate Th2 immune response, inhibiting allergic eosinophilia. As intrauterine undernutrition can attenuate lung inflammation, we investigated the influence of intrauterine undernourishment on the Th1/Th2 cytokine balance and allergic lung inflammation. Intrauterine undernourished offspring were obtained from dams fed 50% of the nourished diet of their counterparts and were immunized at 9 weeks of age. We evaluated the cell counts and cytokine protein expression in the bronchoalveolar lavage, mucus production and collagen deposition, and cytokine gene expression and transcription factors in lung tissue 21 days after ovalbumin immunization. Intrauterine undernourishment significantly reduced inflammatory cell airway infiltration, mucus secretion and collagen deposition, in rats immunized and challenged. Intrauterine undernourished rats also exhibited an altered cytokine expression profile, including higher TNF-alpha and IL-1 beta expression and lower IL-6 expression than well-nourished rats following immunization and challenge. Furthermore, the intrauterine undernourished group showed reduced ratios of the IL-4/IFN-gamma and the transcription factors GATA-3/T-Bet after immunization and challenge. We suggest that the attenuated allergic lung inflammation observed in intrauterine undernourished rats is related to an altered Th1/Th2 cytokine balance resulting from a reduced GATA-3/T-bet ratio. Copyright (C) 2012 S. Karger AG, BaselConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundo de Auxilio aos Docentes e Alunos (FADA-UNIFESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Federal de São Paulo, Inst Ciencias Ambientais Quim & Farmaceut, BR-09972270 São Paulo, BrazilUniv São Paulo, Inst Ciencias Biomed, Dept Imunol, Lab Imunol Transplantes, BR-05508 São Paulo, BrazilUniversidade Federal de São Paulo, Div Nefrol, Lab Imunol Clin & Expt, BR-09972270 São Paulo, BrazilUniv São Paulo, Inst Ciencias Biomed, Dept Farmacol, BR-05508 São Paulo, BrazilUniversidade Federal de São Paulo, Inst Ciencias Ambientais Quim & Farmaceut, BR-09972270 São Paulo, BrazilUniversidade Federal de São Paulo, Div Nefrol, Lab Imunol Clin & Expt, BR-09972270 São Paulo, BrazilFAPESP: 07/07139-3FAPESP: 09/09849-3FAPESP: 09/52119-6FAPESP: 10/01404-0FAPESP: 12/02270-2Web of Scienc

Upregulation of ERK1/2-eNOS via AT2 Receptors Decreases the Contractile Response to Angiotensin II in Resistance Mesenteric Arteries from Obese Rats

It has been clearly established that mitogen-activated protein kinases (MAPKS) are important mediators of angiotensin II (Ang II) signaling via AT1 receptors in the vasculature. However, evidence for a role of these kinases in changes of Ang II-induced vasoconstriction in obesity is still lacking. Here we sought to determine whether vascular MAPKs are differentially activated by Ang II in obese animals. the role of AT2 receptors was also evaluated. Male monosodium glutamate-induced obese (obese) and non-obese Wistar rats (control) were used. the circulating concentrations of Ang I and Ang II, determined by HPLC, were increased in obese rats. Ang II-induced isometric contraction was decreased in endothelium-intact resistance mesenteric arteries from obese compared with control rats and exhibited a retarded AT1 receptor antagonist response. Blocking of AT2 receptors and inhibition of either endothelial nitric oxide synthase (eNOS) or extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) restored Ang II-induced contraction in obese rats. Western blot analysis revealed increased protein expression of AT2 receptors in arteries from obese rats. Basal and Ang II-induced ERK1/2 phosphorylation was also increased in obese rats. Blockade of either AT1 or AT2 receptors corrected the increased ERK1/2 phosphorylation in arteries from obese rats to levels observed in control preparations. Phosphorylation of eNOS was increased in obese rats. Incubation with the ERK1/2 inhibitor before Ang II stimulation did not affect eNOS phosphorylation in control rats; however, it corrected the increased phosphorylation of eNOS in obese rats. These results clearly demonstrate that enhanced AT2 receptor and ERK1/2-induced, NO-mediated vasodilation reduces Ang II-induced contraction in an endothelium-dependent manner in obese rats.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Univ São Paulo, Inst Biomed Sci, Dept Pharmacol, São Paulo, BrazilUniv Fed Goias, Div Cardiovasc Physiol, Dept Biol Sci, Jatai, BrazilUniversidade Federal de São Paulo, Div Nephrol, Dept Med, Escola Paulista Med, São Paulo, BrazilUniversidade Federal de São Paulo, Div Nephrol, Dept Med, Escola Paulista Med, São Paulo, BrazilFAPESP: 2007/58311-0FAPESP: 2008/51622-3FAPESP: 2010/03642-5Web of Scienc

STIM1/Orai1 contributes to sex differences in vascular responses to calcium in spontaneously hypertensive rats. Clin. Sci. (Lond

Sex differences in Ca 2 + -dependent signalling and homoeostasis in the vasculature of hypertensive rats are well characterized. However, sex-related differences in SOCE (store-operated Ca 2 + entry) have been minimally investigated. We hypothesized that vascular protection in females, compared with males, reflects decreased Ca 2 + mobilization due to diminished activation of Orai1/STIM1 (stromal interaction molecule 1). In addition, we investigated whether ovariectomy in females affects the activation of the Orai1/STIM1 pathway. Endothelium-denuded aortic rings from male and female SHRSP (stroke-prone spontaneously hypertensive rats) and WKY (Wistar-Kyoto) rats and from OVX (ovariectomized) or sham female SHRSP and WKY rats were used to functionally evaluate Ca 2 + influx-induced contractions. Compared with females, aorta from male SHRSP displayed: (i) increased contraction during the Ca 2 + -loading period; (ii) similar transient contraction during Ca 2 + release from the intracellular stores; (iii) increased activation of STIM1 and Orai1, as shown by the blockade of STIM1 and Orai1 with neutralizing antibodies, which reversed the sex differences in contraction during the Ca 2 + -loading period; and (iv) increased expression of STIM1 and Orai1. Additionally, we found that aortas from OVX-SHRSP showed increased contraction during the Ca 2 + -loading period and increased Orai1 expression, but no changes in the SR (sarcoplasmic reticulum)-buffering capacity or STIM1 expression. These findings suggest that augmented activation of STIM1/Orai1 in aortas from male SHRSP represents a mechanism that contributes to sex-related impaired control of intracellular Ca 2 + levels. Furthermore, female sex hormones may negatively modulate the STIM/Orai1 pathway, contributing to vascular protection observed in female rats

Influence of age on the development of immunological lung response in intrauterine undernourishment

Objective: We investigated the effect of intrauterine undernourishment on some features of asthma using a model of allergic lung inflammation in rats. The effects of age at which the rats were challenged (5 and 9 wk) were also evaluated. Methods: Intrauterine undernourished offspring were obtained from dams that were fed 50% of the nourished diet of counterparts and were immunized at 5 and 9 wk of age. They were tested for immunoglobulin E anti-ova titers (by passive cutaneous anaphylaxis), cell count in the bronchoal-veolar fluid, leukotriene concentration, airway reactivity, mucus production, and blood corticosterone and leptin concentrations 21 d, after immunologic challenge. Results: Intrauterine undernourishment significantly reduced the antigen-specific immunoglobulin E production, inflammatory cell infiltration into airways, mucus secretion, and production of leukotrienes B-4/C-4 in the lungs in both age groups compared with respective nourished rats. The increased reactivity to methacholine that follows antigen challenge was not affected by intrauterine undernourishment. Corticosterone levels increased with age in the undernourished rats` offspring, but not in the nourished rats` offspring. Undernourished offspring already presented high levels of corticosterone before inflammatory stimulus and were not modified by antigen challenge. Leptin levels increased with challenge in the nourished rats but not in the undernourished rats and could not be related to corticosterone levels in the. undernourished rats. Conclusion: Intrauterine undernourishment has a striking and age-dependent effect on the off spring, reducing lung allergic inflammation. (C) 2008 Elsevier Inc. All rights reserved

Matrix metalloproteinases cleave the β2-adrenergic receptor in spontaneously hypertensive rats

We recently observed the enhanced serine and matrix metalloproteinase (MMP) activity in the spontaneously hypertensive rat (SHR) compared with its normotensive Wistar-Kyoto (WKY) rat and the cleavage of membrane receptors in the SHR by MMPs. We demonstrate in vivo that MMP-7 and MMP-9 injection leads to a vasoconstrictor response in microvessels of rats that is blocked by a specific MMP inhibitor (GM-6001, 1 μM). Multiple pathways may be responsible. Since the β2-adrenergic receptor (β2-AR) is susceptible to the action of endogenous MMPs, we hypothesize that MMPs in the plasma of SHRs are able to cleave the extracellular domain of the β2-AR. SHR arterioles respond in an attenuated fashion to β2-AR agonists and antagonists. Aorta and heart muscle of control Wistar rats were exposed for 24 h (37°C) to fresh plasma of male Wistar and WKY rats and SHRs with and without doxycycline (30 μM) and EDTA (10 mM) to reduce MMP activity. The density of extracellular and intracellular domains of β2-AR was determined by immunohistochemistry. The density of the extracellular domain of β2-AR is reduced in aortic endothelial cells and cardiac microvessels of SHRs compared with that of WKY or Wistar rats. Treatment of the aorta and the heart of control Wistar rats with plasma from SHRs, but not from WKY rats, reduced the number of extracellular domains, but not intracellular domains, of β2-AR in aortic endothelial cells and cardiac microvessels. MMP inhibitors (EDTA and doxycycline) prevented the cleavage of the extracellular domain. Thus MMPs may contribute to the reduced density of the extracellular domain of β2-AR in blood vessels and to the increased arteriolar tone of SHRs compared with normotensive rats

Hydralazine reduces leukocyte migration through different mechanisms in spontaneously hypertensive and normotensive rats

In addition to reducing blood pressure, hydralazine can reduce the production of inflammatory cytokines and reduce the expression of leukocyte adhesion molecules. Differences in leukocyte behavior and leukocyte adhesion molecule expression in spontaneously hypertensive rats (SHR) compared to normotensive rats have been reported. However, whether hydralazine can reduce leukocyte migration in vivo in hypertension and in normotension remains unknown. To address this question, male SHR and Wistar rats were treated for 15 days with hydralazine at a dose of similar to 3.5 mg/kg or similar to 14 mg/kg in their drinking water. The numbers of rollers and adherent and migrated cells were determined by direct vital microscopy, and blood pressure was assessed by tail plethysmography. In addition, following treatment with the higher dose, immunohistochemistry was used to measure the expression of intercellular adhesion molecule-1 (ICAM-1), P-selectin, and platelet-endothelial cell adhesion molecule-1 (PECAM-1) in endothelial cells, while flow cytometry was used to evaluate the expression of leukocyte CD18 and L-selectin. Hydralazine reduced leukocyte adherence and migration in SHR either at the higher, that reduced blood pressure levels, or lower dose, which did not reduce it. Reduced ICAM-1 expression might be involved in the reduced migration observed in SHR. In Wistar rats, only at the higher dose hydralazine reduced blood pressure levels and leukocyte migration. Reduced P-selectin expression might be involved. We therefore conclude that hydralazine reduces leukocyte migration by different mechanisms in SHR and Wistar rats, specifically by reducing ICAM-1 expression in the former and P-selectin expression in the latter. (c) 2008 Elsevier B.V. All rights reserved