Search results for "Intracellular signaling"
showing 10 items of 144 documents
NOTCH, a new signaling pathway implicated in holoprosencephaly.
2011
International audience; Genetics of Holoprosencephaly (HPE), a congenital malformation of the developing human forebrain, is due to multiple genetic defects. Most genes that have been implicated in HPE belong to the sonic hedgehog signaling pathway. Here we describe a new candidate gene isolated from array comparative genomic hybridization redundant 6qter deletions, DELTA Like 1 (DLL1), which is a ligand of NOTCH. We show that DLL1 is co-expressed in the developing chick forebrain with Fgf8. By treating chick embryos with a pharmacological inhibitor, we demonstrate that DLL1 interacts with FGF signaling pathway. Moreover, a mutation analysis of DLL1 in HPE patients revealed a three-nucleoti…
Involvement of cyclin-dependent kinase-5 in the kainic acid-mediated degeneration of glutamatergic synapses in the rat hippocampus.
2011
Increased levels of glutamate causing excitotoxic damage accompany neurological disorders such as ischemia/stroke, epilepsy and some neurodegenerative diseases. Cyclin-dependent kinase-5 (Cdk5) is important for synaptic plasticity and is deregulated in neurodegenerative diseases. However, the mechanisms by which kainic acid (KA)-induced excitotoxic damage involves Cdk5 in neuronal injury are not fully understood. In this work, we have thus studied involvement of Cdk5 in the KA-mediated degeneration of glutamatergic synapses in the rat hippocampus. KA induced degeneration of mossy fiber synapses and decreased glutamate receptor (GluR)6/7 and post-synaptic density protein 95 (PSD95) levels in…
Translational read-through of the RP2 Arg120stop mutation in patient iPSC-derived retinal pigment epithelium cells.
2014
Mutations in the RP2 gene lead to a severe form of X-linked retinitis pigmentosa. RP2 patients frequently present with nonsense mutations and no treatments are currently available to restore RP2 function. In this study, we reprogrammed fibroblasts from an RP2 patient carrying the nonsense mutation c.519C>T (p.R120X) into induced pluripotent stem cells (iPSC), and differentiated these cells into retinal pigment epithelial cells (RPE) to study the mechanisms of disease and test potential therapies. RP2 protein was undetectable in the RP2 R120X patient cells, suggesting a disease mechanism caused by complete lack of RP2 protein. The RP2 patient fibroblasts and iPSC-derived RPE cells showed phe…
Does parental expressed emotion moderate genetic effects in ADHD? An exploration using a genome wide association scan.
2008
Contains fulltext : 70497.pdf (Publisher’s version ) (Closed access) Studies of gene x environment (G x E) interaction in ADHD have previously focused on known risk genes for ADHD and environmentally mediated biological risk. Here we use G x E analysis in the context of a genome-wide association scan to identify novel genes whose effects on ADHD symptoms and comorbid conduct disorder are moderated by high maternal expressed emotion (EE). SNPs (600,000) were genotyped in 958 ADHD proband-parent trios. After applying data cleaning procedures we examined 429,981 autosomal SNPs in 909 family trios. ADHD symptom severity and comorbid conduct disorder was measured using the Parental Account of Ch…
DJ-1 mutations and parkinsonism-dementia-amyotrophic lateral sclerosis complex.
2005
Mutations in DJ-1 gene have been recently shown to cause autosomal recessive early-onset Parkinson’s disease (EOPD) in a large Dutch family and in a small consanguineous Italian family.1 Subsequent to this initial finding, several additional DJ-1 mutations were identified in subjects with EOPD.2–6 We describe a family from southern Italy with three brothers affected by a complex disorder characterized by early-onset parkinsonism-dementia-amyotrophic lateral sclerosis (EOPD-D-ALS). The analysis of the DJ-1 gene showed a novel homozygous mutation (E163K) in exon 7 and a novel homozygous mutation (g.168_185dup) in the promoter region of this gene in living affected subjects
PED is overexpressed and mediates TRAIL resistance in human non-small cell lung cancer
2008
PED (phosphoprotein enriched in diabetes) is a death-effector domain (DED) family member with a broad anti-apoptotic action. PED inhibits the assembly of the death-inducing signalling complex (DISC) of death receptors following stimulation. Recently, we reported that the expression of PED is increased in breast cancer cells and determines the refractoriness of these cells to anticancer therapy. In the present study, we focused on the role of PED in non-small cell lung cancer (NSCLC), a tumour frequently characterized by evasion of apoptosis and drug resistance. Immunohistochemical analysis of a tissue microarray, containing 160 lung cancer samples, indicated that PED was strongly expressed …
TRIB1 constitutes a molecular link between regulation of sleep and lipid metabolism in humans.
2012
Epidemiological studies show association between sleep duration and lipid metabolism. In addition, inactivation of circadian genes induces insulin resistance and hyperlipidemia. We hypothesized that sleep length and lipid metabolism are partially controlled by the same genes. We studied the association of total sleep time (TST) with 60 genetic variants that had previously been associated with lipids. The analyses were performed in a Finnish population-based sample (N = 6334) and replicated in 2189 twins. Finally, RNA expression from mononuclear leucocytes was measured in 10 healthy volunteers before and after sleep restriction. The genetic analysis identified two variants near TRIB1 gene th…
Photoperiodic regulation of cold tolerance and expression levels of regucalcin gene in Drosophila montana
2011
Temperature-induced plasticity of cold tolerance has been reported in many insect species, but cold tolerance can also be affected by changes in day (or night) length. In the present study we elucidate the direct and indirect effects of photoperiod on the cold tolerance of females of two Drosophila montana strains--one which possesses a robust photoperiodic diapause and another which does not. In the diapause-strain the time needed for recovery from chill coma showed a positive correlation with day length, but diapause itself played only a minor role in photoperiodic acclimation. The strain that was not able to enter to diapause as a response to day length also lacked photoperiodic cold acc…
A new evolutionary paradigm for the Parkinson disease gene DJ-1.
2006
The DJ-1 gene is extensively studied because of its involvement in familial Parkinson disease. DJ-1 belongs to a complex superfamily of genes that includes both prokaryotic and eukaryotic representatives. We determine that many prokaryotic groups, such as proteobacteria, cyanobacteria, spirochaetes, firmicutes, or fusobacteria, have genes, often incorrectly called "Thij," that are very close relatives of DJ-1, to the point that they cannot be clearly separated from the eukaryotic DJ-1 genes by phylogenetic analyses of their sequences. In addition, and contrary to a previous study that suggested that DJ-1 genes were animal specific, we show that DJ-1 genes are found in at least 5 of the 6 ma…
Sizzled Is Unique among Secreted Frizzled-related Proteins for Its Ability to Specifically Inhibit Bone Morphogenetic Protein-1 (BMP-1)/Tolloid-like …
2012
BMP-1/tolloid-like proteinases (BTPs) are major enzymes involved in extracellular matrix assembly and activation of bioactive molecules, both growth factors and anti-angiogenic molecules. Although the control of BTP activity by several enhancing molecules is well established, the possibility that regulation also occurs through endogenous inhibitors is still debated. Secreted frizzled-related proteins (sFRPs) have been studied as possible candidates, with highly contradictory results, after the demonstration that sizzled, a sFRP found in Xenopus and zebrafish, was a potent inhibitor of Xenopus and zebrafish tolloid-like proteases. In this study, we demonstrate that mammalian sFRP-1, -2, and …