A PrP(C)-caveolin-Lyn complex negatively controls neuronal GSK3β and serotonin 1B receptor.

The cellular prion protein, PrP(C), is a glycosylphosphatidylinositol-anchored protein, abundant in lipid rafts and highly expressed in the brain. While PrP(C) is much studied for its involvement under its abnormal PrP(Sc) isoform in Transmissible Spongiform Encephalopathies, its physiological role remains unclear. Here, we report that GSK3β, a multifunctional kinase whose inhibition is neuroprotective, is a downstream target of PrP(C) signalling in serotonergic neuronal cells.

Pathogenic prions deviate PrP(C) signaling in neuronal cells and impair A-beta clearance.

The subversion of the normal function exerted by the cellular prion protein (PrP(C)) in neurons by pathogenic prions is assumed to have a central role in the pathogenesis of transmissible spongiform encephalopathies. Using two murine models of prion infection, the 1C11 neuronal cell line and neurospheres, we document that prion infection is associated with the constitutive activation of signaling targets normally coupled with PrP(C), including the Fyn kinase, the mitogen-associated protein kinases ERK1/2 and the CREB transcription factor. PrP(C)-dependent signaling overactivation in infected cells is associated with the recruitment of p38 and JNK stress-associated kinases.

Malaria transmission in Libreville: results of a one year survey.

Background: In Gabon, vector transmission has been poorly studied. Since the implementation of the Roll Back malaria recommendations, clinical studies have shown a decline in the burden of malaria in Libreville, the capital city of Gabon. To better understand the transmission dynamic in Libreville, an entomological survey was conducted in five districts of the city.

Understanding the neurospecificity of Prion protein signaling.

The cellular prion protein PrP(C) is the normal counterpart of the scrapie prion protein PrP(Sc), the main component of the infectious agent of transmissible spongiform encephalopathies (TSEs). It is a ubiquitous cell-surface glycoprotein, abundantly expressed in neurons, which constitute the targets of TSE pathogenesis. The presence of PrP(C) at the surface of neurons is an absolute requirement for the development of prion diseases and corruption of PrP(C) function(s) within an infectious context emerges as a proximal cause for PrP(Sc)-induced neurodegeneration.

The cellular prion protein interacts with the tissue non-specific alkaline phosphatase in membrane microdomains of bioaminergic neuronal cells.

Background: The cellular prion protein, PrP(C), is GPI anchored and abundant in lipid rafts. The absolute requirement of PrP(C) in neurodegeneration associated to prion diseases is well established. However, the function of this ubiquitous protein is still puzzling.

Cellular prion protein coupling to TACE-dependent TNF-alpha shedding controls neurotransmitter catabolism in neuronal cells.

Despite considerable efforts to unravel the role of cellular prion protein (PrP(C)) in neuronal functions, the mechanisms by which PrP(C) takes part in the homeostasis of a defined neuronal phenotype remain poorly characterized. By taking advantage of a neuroectodermal cell line (1C11) endowed with the capacity to differentiate into serotonergic (1C11(5-HT)) or noradrenergic (1C11(NE)) neurons, we assessed the contribution of PrP(C) to bioaminergic cell functions. We established that in 1C11-derived neuronal cells antibody-mediated PrP(C) ligation triggered tumor necrosis factor (TNF)-alpha release, through recruitment of the metalloproteinase TNF-alpha converting enzyme (TACE).

CREB-dependent gene regulation by prion protein: impact on MMP-9 and beta-dystroglycan.

Corruption of the normal function of the cellular prion protein (PrP(C)) by the scrapie isoform (PrP(Sc)) emerges as a critical causal event in Transmissible Spongiform Encaphalopathies (TSE) pathogenesis. However, PrP(C) physiological role remains unclear. By exploiting the properties of the 1C11 neuroectodermal cell line, able to convert into 1C11(5-HT) serotonergic or 1C11(NE) noradrenergic neuronal cells, we assigned a signaling function to PrP(C).

Prions impair bioaminergic functions through serotonin- or catecholamine-derived neurotoxins in neuronal cells.

The conversion of the cellular prion protein, PrP(C), to an abnormal isoform, PrP(Sc), is a central event leading to neurodegeneration in prion diseases. Deciphering the molecular and cellular changes imparted by PrP(Sc) accumulation remains an arduous task due to the small number of cell lines supporting prion replication. Here we introduce the 1C11 cell line as a new in vitro model to investigate prion pathogenesis.

Overstimulation of PrPC signaling pathways by prion peptide 106-126 causes oxidative injury of bioaminergic neuronal cells.

Transmissible spongiform encephalopathies, also called prion diseases, are characterized by neuronal loss linked to the accumulation of PrP(Sc), a pathologic variant of the cellular prion protein (PrP(C)). Although the molecular and cellular bases of PrP(Sc)-induced neuropathogenesis are not yet fully understood, increasing evidence supports the view that PrP(Sc) accumulation interferes with PrP(C) normal function(s) in neurons. In the present work, we exploit the properties of PrP-(106-126), a synthetic peptide encompassing residues 106-126 of PrP, to investigate into the mechanisms sustaining prion-associated neuronal damage.

Optical imaging of luminescence for in vivo quantification of gene electrotransfer in mouse muscle and knee.

Background: Optical imaging is an attractive non-invasive way to evaluate the expression of a transferred DNA, mainly thanks to its lower cost and ease of realization. In this study optical imaging was evaluated for monitoring and quantification of the mouse knee joint and tibial cranial muscle electrotransfer of a luciferase encoding plasmid. Optical imaging was applied to study the kinetics of luciferase expression in both tissues.