Céline Haby

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LRH-1 is an orphan nuclear receptor predominantly expressed in tissues of endodermal origin, where it controls development and cholesterol homeostasis. We show here that LRH-1 induces cell proliferation through the concomitant induction of cyclin D1 and E1, an effect that is potentiated by its interaction with beta-catenin. Whereas beta-catenin coactivates(More)
Dopamine D2 receptor gene expression was examined in rat striatum after chronic treatment with N-methyl-D-aspartate (NMDA) receptor antagonists (ketamine at 15 mg/kg/day or MK-801 at 0.1, 0.2 and 0.4 mg/kg/day per os, for 50 days). The long-isoform mRNA, as well as the total D2 mRNA expression were induced. No change was noticed in striatal dopamine release(More)
Liver receptor homolog 1 (LRH-1) is an orphan nuclear receptor that synergizes with beta-catenin/T cell factor 4 signaling to stimulate intestinal crypt cell renewal. We evaluated here the impact of haploinsufficiency of LRH-1 on intestinal tumorigenesis by using two independent mouse models of human colon tumorigenesis. Haploinsufficiency of LRH-1 blunts(More)
Overexpression of the adipocyte differentiation and determination factor-1 (ADD-1) or sterol regulatory element binding protein-1 (SREBP-1) induces the expression of numerous genes involved in lipid metabolism, including lipoprotein lipase (LPL). Therefore, we investigated whether LPL gene expression is controlled by changes in cellular cholesterol(More)
The biological activity of many proteins, including voltage-sensitive ion channels, is controlled by their state of phosphorylation. Ca2+ influx through voltage-activated L-type Ca2+ channels serves as the major stimulatory signal in insulin-secreting cells. We have now investigated the extent to which Ca2+ handling in clonal insulin-secreting RiNm5F cells(More)
Stimulation of several second messenger pathways induces the expression of immediate early genes such as c-fos, c-jun, junB, and junD, but little is known about their induction via the stimulation of the cyclic GMP pathway. Here we looked at the expression of early genes in pheochromocytoma PC12 cells after activation of cytosolic guanylate cyclase by(More)
Acute injection of haloperidol, a dopamine D2 receptor antagonist, is known to increase immediate early gene expression of the fos and jun families in rodent striatal neurons. A set of gene induction, including c-fos, jun B and TIS8/egr-1, was found when haloperidol was added to PC12 cells in culture. Electrophoretic mobility-shift assays show that(More)
The serine/threonine protein phosphatase inhibitor okadaic acid (OA) was found to enhance mRNA transcripts of c-fos and of the jun family of proto-oncogenes including c-jun, jun B and jun D in cultured pheochromocytoma PC12 cells. This expression remained elevated for more than 8 hr. An increase in the binding of the transcription factor activator protein 1(More)
By injecting 6-hydroxydopamine into the pars compacta of the substantia nigra, we produced a hemiparkinsonian rat model in which there is almost complete destruction of the dopaminergic nigrostriatal pathway but sparing of the dopaminergic mesolimbic system. The lesion has been characterized by several criteria: a rotational behavior in response to(More)