10 documents found, page 1 of 1
Extracellular vesicles improve GABAergic transmission in Huntington's disease i...
Beatriz, Margarida; Rodrigues, Ricardo J.; Vilaça, Rita; Egas, Conceição; Pinheiro, Paulo S.; Daley, George Q.; Schlaeger, Thorsten M.; Raimundo, NunoBackground: Extracellular vesicles (EVs) carry bioactive molecules associated with various biological processes, including miRNAs. In both Huntington’s disease (HD) models and human samples, altered expression of miRNAs involved in synapse regulation was reported. Recently, the use of EV cargo to reverse phenotypic alterations in disease models with synaptopathy as the end result of the pathophysiological casca...
Transient incubation of cultured hippocampal neurons in the absence of magnesiu...
Mele, Miranda; Vieira, Ricardo; Correia, Bárbara; Luca, Pasqualino De; Duarte, Filipe V.; Pinheiro, Paulo S.; Duarte, Carlos B.Cell culture models are important tools to study epileptogenesis mechanisms. The aim of this work was to characterize the spontaneous and synchronized rhythmic activity developed by cultured hippocampal neurons after transient incubation in zero Mg2+ to model Status Epilepticus. Cultured hippocampal neurons were transiently incubated with a Mg2+-free solution and the activity of neuronal networks was evaluated ...
Synaptotagmin-7 places dense-core vesicles at the cell membrane to promote Munc...
Tawfik, Bassam; Martins, Joana S; Houy, Sébastien; Imig, Cordelia; Pinheiro, Paulo S.; Wojcik, Sonja M; Brose, Nils; Cooper, Benjamin HSynaptotagmins confer calcium-dependence to the exocytosis of secretory vesicles, but how coexpressed synaptotagmins interact remains unclear. We find that synaptotagmin-1 and synaptotagmin-7 when present alone act as standalone fast and slow Ca2+-sensors for vesicle fusion in mouse chromaffin cells. When present together, synaptotagmin-1 and synaptotagmin-7 are found in largely non-overlapping clusters on dens...
Unraveling the Nanoscopic Organization and Function of Central Mammalian Presyn...
Carvalhais, Lia G.; Martinho, Vera C.; Ferreiro, Elisabete; Pinheiro, Paulo S.The complex, nanoscopic scale of neuronal function, taking place at dendritic spines, axon terminals, and other minuscule structures, cannot be adequately resolved using standard, diffraction-limited imaging techniques. The last couple of decades saw a rapid evolution of imaging methods that overcome the diffraction limit imposed by Abbe's principle. These techniques, including structured illumination microscop...
Endophilin-A coordinates priming and fusion of neurosecretory vesicles via inte...
Gowrisankaran, Sindhuja; Houy, Sébastien; Del Castillo, Johanna G Peña; Steubler, Vicky; Gelker, Monika; Kroll, Jana; Pinheiro, Paulo S.Endophilins-A are conserved endocytic adaptors with membrane curvature-sensing and -inducing properties. We show here that, independently of their role in endocytosis, endophilin-A1 and endophilin-A2 regulate exocytosis of neurosecretory vesicles. The number and distribution of neurosecretory vesicles were not changed in chromaffin cells lacking endophilin-A, yet fast capacitance and amperometry measurements re...
Poster: Breast cancer screening in Madeira 1999-2018: Comparison between partic...
Fraga, Cláudia; Serrão, Patrícia; Camacho, Carolina; Camacho, José; Veira, Joaquim; Armas, Mónica; Ferreira, Nuno; Callahan, Karen E.Female breast cancer (BC) is the most frequently diagnosed cancer in most countries and the leading cause of cancer death among women worldwide. Since 1999, a population-based bi-annual BC screening mammography programme for women aged 45-69 has been in place in Madeira, with participation reported at 57% of all eligible females of the archipelago population (255,000). While all women receive an appointment let...
Doc2B acts as a calcium sensor for vesicle priming requiring synaptotagmin-1, M...
Houy, Sébastien; Groffen, Alexander J; Ziomkiewicz, Iwona; Verhage, Matthijs; Pinheiro, Paulo S.; Sørensen, Jakob BalslevDoc2B is a cytosolic protein with binding sites for Munc13 and Tctex-1 (dynein light chain), and two C2-domains that bind to phospholipids, Ca2+ and SNAREs. Whether Doc2B functions as a calcium sensor akin to synaptotagmins, or in other calcium-independent or calcium-dependent capacities is debated. We here show by mutation and overexpression that Doc2B plays distinct roles in two sequential priming steps in mo...
The RNA-Binding Protein hnRNP K Mediates the Effect of BDNF on Dendritic mRNA M...
Leal, Graciano; Comprido, Diogo; Luca, Pasqualino De; Morais, Eduardo Manuel Firmo; Rodrigues, Luís; Mele, Miranda; Santos, Ana R.; Costa, Rui O.Brain-derived neurotrophic factor (BDNF) is an important mediator of long-term synaptic potentiation (LTP) in the hippocampus. The local effects of BDNF depend on the activation of translation activity, which requires the delivery of transcripts to the synapse. In this work, we found that neuronal activity regulates the dendritic localization of the RNA-binding protein heterogeneous nuclear ribonucleoprotein K ...
Up-regulation of neuropeptide Y levels and modulation of glutamate release thro...
Silva, Ana P.; Xapelli, Sara; Pinheiro, Paulo S.; Ferreira, Raquel; Lourenço, Joana; Cristóvão, Armando; Grouzmann, Eric; Cavadas, CláudiaKainate-induced epilepsy has been shown to be associated with increased levels of neuropeptide Y (NPY) in the rat hippocampus. However, there is no information on how increased levels of this peptide might modulate excitation in kainate-induced epilepsy. In this work, we investigated the modulation of glutamate release by NPY receptors in hippocampal synaptosomes isolated from epileptic rats. In the acute phase...
Activation of neuropeptide Y receptors is neuroprotective against excitotoxicit...
Silva, Ana P.; Pinheiro, Paulo S.; Carvalho, Arsélio P.; Carvalho, Caetana M.; Jakobsen, Birthe; Zimmer, Jens; Malva, João O.Glutamate and NPY have been implicated in hippocampal neuropathology in temporal lobe epilepsy. Thus, we investigated the involvement of NPY receptors in mediating neuroprotection against excitotoxic insults in organotypic cultures of rat hippocampal slices. Exposure of hippocampal slice cultures to 2 μM AMPA (α-amino-3-hydroxy-5-methyl-isoxazole-4- propionate) induced neuronal degeneration, monitored by propid...