Search results for "Gene expression."
showing 10 items of 4076 documents
Atrial natriuretic peptide secretion during development of the rat supraoptic nucleus
2009
Since a relationship between atrial natriuretic peptide and oxytocin was recently demonstrated in the heart (Gutkowska et al., 1997), the aim of this study was to determine whether a relationship between the two peptides is present also in the rat hypothalamus. For this purpose, we measured ANP-ontogeny in the rat hypothalamus immunohistochemically and compared it with oxytocin-ontogeny which we previously studied. The results showed that the ANP-peptide and mRNA-ANP start at the 18th day of the fetal life. Our earlier data for oxytocin in the rat hypothalamus showed that only mRNA-oxytocin appeared the 18th day of foetal life (Farina Lipari et al., 2001); thus, at the 18th day of foetal li…
The LDL receptor in the retina: the missing link in aging, the new target in dietary prevention
2012
National audience; Purpose: The discovery of the LDL receptor (LDLR) in 1985 by Brown and Goldstein was awarded by a Nobel Prize. The LDLR has initially been identified for its role in mediating the endocytosis of LDL particles in the vascular endothelium. The deposition of lipids, including cholesterol and cholesteryl esters in Bruch’s Membrane in the one hand, and in the vessel intima in the other hand, is one of the common features of age related macular degeneration (AMD) and cardiovascular disease (CVD). Dietary habits with high intakes of omega 3 long chain fatty acids (LCFA) have been associated with AMD prevention. Similar effects have been demonstrated in CVD prevention. The mechan…
Fructose diet induced short-term impairment of cone sensitivity and gene expression in rat retina
2012
National audience; Abstract: Purpose A high fructose diet has been widely used to trigger insulin resistance in rodent; insulin resistance is one of the major risk factor for the development of type 2 diabetes. Thirty to 40% of diabetic patients develop diabetic retinopathy. In this study, we aimed to evaluate the short-term effect, at 1, 3, 5, 8 days, of a 60% fructose diet, on photoreceptor sensitivity and gene expression in the retina of Brown Norway rats. Methods: Flicker electroretinograms (8Hz) were recorded under anesthesia, from both eyes simultaneously in order to study sensitivity of photoreceptors. Then, rats were euthanized and enucleated. Retinae and posterior poles were collec…
The genomics of the human endometrium
2012
AbstractThe endometrium is a complex tissue that lines the inside of the endometrial cavity. The gene expression of the different endometrial cell types is regulated by ovarian steroids and paracrine-secreted molecules from neighbouring cells. Due to this regulation, the endometrium goes through cyclic modifications which can be divided simply into the proliferative phase, the secretory phase and the menstrual phase. Successful embryo implantation depends on three factors: embryo quality, the endometrium's state of receptivity, and a synchronised dialogue between the maternal tissue and the blastocyst. There is a need to characterise the endometrium's state of receptivity in order to preven…
α-secretase mediated conversion of the amyloid precursor protein derived membrane stub C99 to C83 limits Aβ generation
2009
The Swedish mutation within the amyloid precursor protein (APP) causes early-onset Alzheimer's disease due to increased cleavage of APP by BACE1. While beta-secretase shedding of Swedish APP (APPswe) largely results from an activity localized in the late secretory pathway, cleavage of wild-type APP occurs mainly in endocytic compartments. However, we show that liberation of Abeta from APPswe is still dependent on functional internalization from the cell surface. Inspite the unchanged overall beta-secretase cleaved soluble APP released from APP(swe) secretion, mutations of the APPswe internalization motif strongly reduced C99 levels and substantially decreased Abeta secretion. We point out t…
Wood-derived estrogens: studies in vitro with breast cancer cell lines and in vivo in trout.
1996
The wood-derived compound, beta-sitosterol (purity > 90%), was shown to be estrogenic in fish. It induced the expression of the vitellogenin gene in the liver of juvenile and methyltestosterone-treated rainbow trout. Structural similarities to beta-sitosterol notwithstanding, cholesterol, citrostadienol, beta-sitostanol, and 5-androstene-3 beta,17 beta-diol, an estrogenic member of the androstenic steroid group, were inactive. An abietic acid mixture (37% abietic acid, 6% dehydroabietic acid, and a remainder of unknown compounds) showed slight hormonal activity in feed, but it was completely inactive when given intraperitoneally in implants. The estrogenic component of the abietic acid prep…
From structural biochemistry to expression profiling: Neuroprotective activities of estrogen
2005
Abstract Estrogens are neuromodulatory and neuroprotective hormones. Chemically, estrogens are steroid compounds and unfold most of their activities through the activation of nuclear receptors that bind to specific target genes and control their transcription. Two subtypes of estrogen receptors are known (estrogen receptor α and estrogen receptor β) and they are expressed throughout the body including the CNS and in particular the brain. We employed large scale DNA-chip-analysis to display the gene expression pattern differentially regulated by both estrogen receptor subtypes in human neuronal cells. We identified different gene families regulated by estrogen receptors that complement the k…
Inducibility of the avidin gene by progesterone is suppressed during estrogen-induced cytodifferentiation.
1992
Abstract We have studied epithelial differentiation of the chick oviduct as induced by diethylstilbestrol (DES) and 17β-estradiol (E 2 ). The proportion of goblet cells in the oviduct was slightly higher after E 2 than after DES treatment. Also avidin induction by progesterone was stronger following DES than E 2 priming. In the estrogen pretreated oviduct epithelium, avidin expression was induced by progesterone in the surface epithelial cells, protodifferentiated gland cells and tubular gland cells, but not in goblet cells. During prolonged estrogen treatment, however, the inducibility of avidin by progesterone ceased in tubular gland cells but not in surface epithelial cells. The estrogen…
Constitutive androstane receptor activation stimulates faecal bile acid excretion and reverse cholesterol transport in mice.
2010
The constitutive androstane receptor (CAR) is a nuclear receptor expressed in the liver and involved in xenobiotic metabolism. The aim of this study was to assess whether pharmacological CAR activation could affect neutral sterol and bile acid elimination under conditions of cholesterol overload.Wild type, Car-/-, ApoE-/-, and low-density lipoprotein receptor (Ldlr)-/- mice fed a western-type diet were treated with the CAR agonist TCPOBOP.CAR activation was associated with a decrease in faecal cholesterol output related to the repression of the Abcg5/g8 cholesterol transporters. In contrast, TCPOBOP treatment induced a marked increase (up to three fold, p0.01) in the elimination of faecal b…
Effect of Soluble Interleukin-6 Receptor on Interleukin-6 Synthesis in Human Skin Fibroblasts
1996
Abstract In this study the ability of soluble interleukin-6 receptor (sIL-6R) to stimulate interleukin-6 (IL-6) synthesis in human fibroblasts is described. It was found that sIL-6R, in combination with endogenous or exogenous IL-6, markedly upregulated IL-6 synthesis. These data suggest that increased IL-6 production after stimulation by either interleukin-1 or tumor necrosis factor-α would result in complex formation with sIL-6R, rapid uptake, and further synthesis of this cytokine. Furthermore, it would explain the decrease in sIL-6R plasma levels observed in patients suffering from sepsis.