Shaw M

References (5)

Title : Differential phosphoprotein signaling in the cortex in mouse models of Gulf War Illness using corticosterone and acetylcholinesterase inhibitors - Penatzer_2021_Heliyon_7_e07552
Author(s) : Penatzer JA , Miller JV , Prince N , Shaw M , Lynch C , Newman M , Hobbs GR , Boyd JW
Ref : Heliyon , 7 :e07552 , 2021
Abstract : AIMS: Veterans from the 1990-91 Gulf War were exposed to acetylcholinesterase inhibitors (AChEIs), and, following service, an estimated one-third began suffering from a medically unexplained, multi-symptom illness termed Gulf War Illness (GWI). Previous research has developed validated rodent models that include exposure to exogenous corticosterone (CORT) and AChEIs to simulate high stress and chemical exposures encountered in theater. This combination of exposures in mice resulted in a marked increase in neuroinflammation, which is a common symptom of veterans suffering from GWI. To further elucidate the mechanisms associated with these mouse models of GWI, an investigation into intracellular responses in the cortex were performed to characterize the early cellular signaling changes associated with this exposure-initiated neuroinflammation. MAIN METHODS: Adult male C57BL/6J mice were exposed to CORT in the drinking water (200 microg/mL) for 7 days followed by a single intraperitoneal injection of diisopropyl fluorophosphate (DFP; 4.0 mg/kg) or chlorpyrifos oxon (CPO; 8.0 mg/kg), on day 8 and euthanized 0.5, 2, and 24 h post-injection. Eleven post-translationally modified protein targets were measured using a multiplexed ELISA. KEY FINDINGS: Phosphoprotein responses were found to be exposure specific following AChEI insult, with and without CORT. Specifically, CORT + CPO exposure was found to sequentially activate several phosphoproteins involved in mitogen activated protein kinase signaling (p-MEK1/2, p-ERK1/2, and p-JNK). DFP alone similarly increased proteins in this pathway (p-RPS6, and p-JNK), but the addition of CORT ameliorated these affects. SIGNIFICANCE: The results of this study provide insight into differentially activated pathways depending on AChEI in these GWI models.
ESTHER : Penatzer_2021_Heliyon_7_e07552
PubMedSearch : Penatzer_2021_Heliyon_7_e07552
PubMedID: 34307952

Title : Novel mutations in NLGN3 causing autism spectrum disorder and cognitive impairment - Quartier_2019_Hum.Mutat_40_2021
Author(s) : Quartier A , Courraud J , Thi Ha T , McGillivray G , Isidor B , Rose K , Drouot N , Savidan MA , Feger C , Jagline H , Chelly J , Shaw M , Laumonnier F , Gecz J , Mandel JL , Piton A
Ref : Hum Mutat , 40 :2021 , 2019
Abstract : The X-linked NLGN3 gene, encoding a postsynaptic cell adhesion molecule, was involved in a nonsyndromic monogenic form of autism spectrum disorder (ASD) by the description of one unique missense variant, p.Arg451Cys (Jamain et al. 2003). We investigated here the pathogenicity of additional missense variants identified in two multiplex families with intellectual disability (ID) and ASD: c.1789C>T, p.Arg597Trp, previously reported by our group (Redin et al. 2014) and present in three affected cousins and c.1540C>T, p.Pro514Ser, identified in two affected brothers. Overexpression experiments in HEK293 and HeLa cell lines revealed that both variants affect the level of the mature NLGN3 protein, its localization at the plasma membrane and its presence as a cleaved form in the extracellular environment, even more drastically than what was reported for the initial p.Arg451Cys mutation. The variants also induced an unfolded protein response, probably due to the retention of immature NLGN3 proteins in the endoplasmic reticulum. In comparison, the c.1894A>G, p.Ala632Thr and c.1022T>C, p.Val341Ala variants, present in males from the general population, have no effect. Our report of two missense variants affecting the normal localization of NLGN3 in a total of five affected individuals reinforces the involvement of the NLGN3 gene in a neurodevelopmental disorder characterized by ID and ASD.
ESTHER : Quartier_2019_Hum.Mutat_40_2021
PubMedSearch : Quartier_2019_Hum.Mutat_40_2021
PubMedID: 31184401
Gene_locus related to this paper: human-NLGN3

Title : Structural elements regulating amyloidogenesis: a cholinesterase model system - Jean_2008_PLoS.One_3_e1834
Author(s) : Jean L , Lee CF , Shaw M , Vaux DJ
Ref : PLoS ONE , 3 :e1834 , 2008
Abstract : Polymerization into amyloid fibrils is a crucial step in the pathogenesis of neurodegenerative syndromes. Amyloid assembly is governed by properties of the sequence backbone and specific side-chain interactions, since fibrils from unrelated sequences possess similar structures and morphologies. Therefore, characterization of the structural determinants driving amyloid aggregation is of fundamental importance. We investigated the forces involved in the amyloid assembly of a model peptide derived from the oligomerization domain of acetylcholinesterase (AChE), AChE(586-599), through the effect of single point mutations on beta-sheet propensity, conformation, fibrilization, surfactant activity, oligomerization and fibril morphology. AChE(586-599) was chosen due to its fibrilization tractability and AChE involvement in Alzheimer's disease. The results revealed how specific regions and residues can control AChE(586-599) assembly. Hydrophobic and/or aromatic residues were crucial for maintaining a high beta-strand propensity, for the conformational transition to beta-sheet, and for the first stage of aggregation. We also demonstrated that positively charged side-chains might be involved in electrostatic interactions, which could control the transition to beta-sheet, the oligomerization and assembly stability. Further interactions were also found to participate in the assembly. We showed that some residues were important for AChE(586-599) surfactant activity and that amyloid assembly might preferentially occur at an air-water interface. Consistently with the experimental observations and assembly models for other amyloid systems, we propose a model for AChE(586-599) assembly in which a steric-zipper formed through specific interactions (hydrophobic, electrostatic, cation-pi, SH-aromatic, metal chelation and polar-polar) would maintain the beta-sheets together. We also propose that the stacking between the strands in the beta-sheets along the fiber axis could be stabilized through pi-pi interactions and metal chelation. The dissection of the specific molecular recognition driving AChE(586-599) amyloid assembly has provided further knowledge on such poorly understood and complicated process, which could be applied to protein folding and the targeting of amyloid diseases.
ESTHER : Jean_2008_PLoS.One_3_e1834
PubMedSearch : Jean_2008_PLoS.One_3_e1834
PubMedID: 18350169

Title : Heterologous amyloid seeding: revisiting the role of acetylcholinesterase in Alzheimer's disease - Jean_2007_PLoS.One_2_e652
Author(s) : Jean L , Thomas B , Tahiri-Alaoui A , Shaw M , Vaux DJ
Ref : PLoS ONE , 2 :e652 , 2007
Abstract : Neurodegenerative diseases associated with abnormal protein folding and ordered aggregation require an initial trigger which may be infectious, inherited, post-inflammatory or idiopathic. Proteolytic cleavage to generate vulnerable precursors, such as amyloid-beta peptide (Abeta) production via beta and gamma secretases in Alzheimer's Disease (AD), is one such trigger, but the proteolytic removal of these fragments is also aetiologically important. The levels of Abeta in the central nervous system are regulated by several catabolic proteases, including insulysin (IDE) and neprilysin (NEP). The known association of human acetylcholinesterase (hAChE) with pathological aggregates in AD together with its ability to increase Abeta fibrilization prompted us to search for proteolytic triggers that could enhance this process. The hAChE C-terminal domain (T40, AChE(575-614)) is an exposed amphiphilic alpha-helix involved in enzyme oligomerisation, but it also contains a conformational switch region (CSR) with high propensity for conversion to non-native (hidden) beta-strand, a property associated with amyloidogenicity. A synthetic peptide (AChE(586-599)) encompassing the CSR region shares homology with Abeta and forms beta-sheet amyloid fibrils. We investigated the influence of IDE and NEP proteolysis on the formation and degradation of relevant hAChE beta-sheet species. By combining reverse-phase HPLC and mass spectrometry, we established that the enzyme digestion profiles on T40 versus AChE(586-599), or versus Abeta, differed. Moreover, IDE digestion of T40 triggered the conformational switch from alpha- to beta-structures, resulting in surfactant CSR species that self-assembled into amyloid fibril precursors (oligomers). Crucially, these CSR species significantly increased Abeta fibril formation both by seeding the energetically unfavorable formation of amyloid nuclei and by enhancing the rate of amyloid elongation. Hence, these results may offer an explanation for observations that implicate hAChE in the extent of Abeta deposition in the brain. Furthermore, this process of heterologous amyloid seeding by a proteolytic fragment from another protein may represent a previously underestimated pathological trigger, implying that the abundance of the major amyloidogenic species (Abeta in AD, for example) may not be the only important factor in neurodegeneration.
ESTHER : Jean_2007_PLoS.One_2_e652
PubMedSearch : Jean_2007_PLoS.One_2_e652
PubMedID: 17653279

Title : Changes in plasma levels of reproductive hormones during first sexual maturation in European male sea bass (Dicentrarchus labrax L.) under artificial day lengths -
Author(s) : Rodriguez L , Begtashi I , Zanuy S , Shaw M , Carrillo M
Ref : Aquaculture , 202 :235 , 2001