Search results for "down-regulation"
showing 10 items of 310 documents
Cholesterol levels and risk of hemorrhagic transformation after acute ischemic stroke.
2011
<i>Background:</i> The association between cholesterol levels and hemorrhagic transformation (HT) is still controversial. Studies investigating this issue are influenced by treatments as some are characterized by a higher risk of HT. The aim of our study was to evaluate, in a hospital-based series of patients not treated with thrombolysis, the relationship between cholesterol levels and HT. <i>Methods:</i> We retrospectively collected information about total cholesterol (TC) and low-density lipoprotein cholesterol (LDLC) levels at admission in a consecutive series of 240 patients with anterior ischemic stroke (IS). The TC and LDLC levels were arranged in 3 groups acc…
17β-Estradiol Reduces Nitric Oxide Production in the Guinea Pig Cochlea
2013
Intense noise exposure and the application of ototoxic substances result in increased levels of reactive oxygen species (ROS) and reactive nitrogen species (RNS), such as nitric oxide (NO). In order to reduce the free NO concentration in the inner ear under pathological conditions, the use of natural cytoprotective substances such as 17β-estradiol is a promising therapeutic concept. In male guinea pigs the organ of Corti and the lateral wall were isolated from the cochlea and afterwards incubated for 6 h in cell-culture medium. 17β-Estradiol was adjusted in 2 concentrations to organ cultures of the right ears (12 animals per concentration). The left ears were used as controls. The NO produc…
Impaired Vitamin D Signaling in Endothelial Cell Leads to an Enhanced Leukocyte-Endothelium Interplay: Implications for Atherosclerosis Development
2015
Endothelial cell activation leading to leukocyte recruitment and adhesion plays an essential role in the initiation and progression of atherosclerosis. Vitamin D has cardioprotective actions, while its deficiency is a risk factor for the progression of cardiovascular damage. Our aim was to assess the role of basal levels of vitamin D receptor (VDR) on the early leukocyte recruitment and related endothelial cell-adhesion-molecule expression, as essential prerequisites for the onset of atherosclerosis. Knockdown of VDR in endothelial cells (shVDR) led to endothelial cell activation, characterized by upregulation of VCAM-1, ICAM-1 and IL-6, decreased peripheral blood mononuclear cell (PBMC) ro…
Mechanisms underlying the diabetes-induced hyporeactivity of the rabbit carotid artery to atrial natriuretic peptide
2010
Abstract Atrial natriuretic peptide (ANP) plays an important role in the pathophysiology of the vascular complications in diabetes. The working hypothesis was that diabetes might modify the vascular actions of ANP in isolated rabbit carotid arteries and the mechanisms involved in these actions. ANP (10 −12 –10 −7 M) induced a relaxation of precontracted carotid arteries, which was lower in diabetic than in control rabbits. In arteries from both groups of animals, endothelium removal increased the ANP-induced relaxation. Isatin inhibited the relaxation to ANP both in arteries with and without endothelium. Carotid arteries from diabetic rabbits showed a decreased natriuretic peptide receptor…
Administration of keratinocyte growth factor down-regulates the pulmonary capacity of acetylcholine production.
2007
Abstract Keratinocyte growth factor protects the lung against various injurious stimuli. The protective mechanisms, however, are not yet fully understood. The aim of this study is to determine the influence of keratinocyte growth factor on the pulmonary capacity to synthesize acetylcholine, a potent regulator of pulmonary functions which is potentially involved in lung damage. Rats were treated twice (days 1 and 2) intratracheally with keratinocyte growth factor and analyzed at day 4. The mRNA expression of choline acetyltransferase – the acetylcholine synthesizing enzyme – was analyzed by real-time RT-PCR in the lung and in isolated alveolar epithelial type II cells. Choline acetyltransfer…
Lasting downregulation of the lipid peroxidation enzymes in the prefrontal cortex of mice susceptible to stress-induced anhedonia
2015
International audience; Antioxidant enzymes and lipid peroxidation in the brain are involved in neuropsychiatric pathologies, including depression. 14- or 28-day chronic stress model induced a depressive syndrome defined by lowered reward sensitivity in C57BL/6J mice and changed gene expression of peroxidation enzymes as shown in microarray assays. We studied how susceptibility or resilience to anhedonia is related to lipid peroxidation in the prefrontal cortex (PFC). With 14-day stress, a comparison of the activities of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPX) and accumulation of malondialdehyde (MDA) revealed a decrease of the first two measures in suscepti…
Down-regulation of the expression of endothelial NO synthase is likely to contribute to glucocorticoid-mediated hypertension.
1999
Hypertension is a side effect of systemically administered glucocorticoids, but the underlying molecular mechanism remains poorly understood. Ingestion of dexamethasone by rats telemetrically instrumented increased blood pressure progressively over 7 days. Plasma concentrations of Na + and K + and urinary Na + and K + excretion remained constant, excluding a mineralocorticoid-mediated mechanism. Plasma NO 2 − /NO 3 − (the oxidation products of NO) decreased to 40%, and the expression of endothelial NO synthase (NOS III) was found down-regulated in the aorta and several other tissues of glucocorticoid-treated rats. The vasodilator response of resistance arterioles was tested by intravital m…
Transient oligemia is associated with long-term changes in binding densities of cortical inhibitory GABAA receptors in the rat brain
2009
Recently, we could demonstrate in rats that a short transient oligemic period of only 20-minute duration, induced by systemic hypotension, resulted in a transient decline of spatial memory capacities without any histological damage over a subsequent period of 6 months. In our present study, we checked for more subtle alterations within the highly vulnerable hippocampal CA1 subfield using quantification of neuronal cell density and semi-quantitative analysis of the ischemia-sensitive protein MAP2. Since hippocampal excitatory and inhibitory neurotransmitter receptors are crucially involved in spatial memory processes, quantitative in vitro receptor autoradiography was performed using [(3)H]M…
The impact of ovarian stimulation on the expression of candidate reprogramming genes in mouse preimplantation embryos.
2012
Ovarian stimulation with gonadotrophins is an integral part of assisted reproductive technologies in human subfertility/infertility treatment. Recent findings have associated ovarian stimulation with the increased incidence of imprinting disorders in humans as well as defects in genome-wide methylation reprogramming and, in particular, imprinting in mice. Here, we present the first study that determined the impact of ovarian stimulation on the expression of developmentally important reprogramming genes <i>(Apex1, Lig1, Lig3, Mbd2, Mbd3, Mbd4, </i>and<i> Polb)</i> in single early mouse morula embryos (16-cell stage). Using absolute quantification of mRNA by quantitati…
Expanded CTG repeats trigger miRNA alterations in Drosophila that are conserved in myotonic dystrophy type 1 patients
2013
Myotonic dystrophy type 1 (DM1) is caused by the expansion of CTG repeats in the 3' untranslated region of the DMPK gene. Several missplicing events and transcriptional alterations have been described in DM1 patients. A large number of these defects have been reproduced in animal models expressing CTG repeats alone. Recent studies have also reported miRNA dysregulation in DM1 patients. In this work, a Drosophila model was used to investigate miRNA transcriptome alterations in the muscle, specifically triggered by CTG expansions. Twenty miRNAs were differentially expressed in CTG-expressing flies. Of these, 19 were down-regulated, whereas 1 was up-regulated. This trend was confirmed for thos…