IBCN   20355
INSTITUTO DE BIOLOGIA CELULAR Y NEUROCIENCIA "PROFESOR EDUARDO DE ROBERTIS"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Purified meningeal cells induce astroglial scar?like structures in vitro
Autor/es:
RAJA SEKHAR MANNAVA ; VERONICA MURTA; ALEJANDRO VILLAREAL; ALBERTO JAVIER RAMOS
Lugar:
Buenos Aires
Reunión:
Congreso; International Congress of Translational Medicine; 2014
Institución organizadora:
International Milstein-Kohler Program in Biomedical Sciences
Resumen:
Reactive gliosis is a generic response to brain injury mediated by astrocytes and microglia. Following reactive gliosis, areas of brain injury may become surrounded by a dense astroglial layer known as glial scar. Even though glial scar can limit the area of brain damage, it is also a major impediment for neuronal reconnection and a serious obstacle for functional recovery. Thus, the study of the mechanisms of assembly/deassembly of glial scar is necessary to identify potential pharmacological targets for therapeutic interventions. Primary astroglial cultures, mixed glial or meningeal cell cultures were obtained from Wistar rat pups (3 days old). On 24 well plates, confluent astroglial cultures were co-cultured with meningeal cells (7000-15000-30000 cells per well). Meningeal cells essentially contained meningeal macrophages, dendritic cells and few fibroblasts. Glio-meningeal co-cultures were followed by time-lapse microscopy for 3 days. After that time, co-cultures were fixed with paraformaldehyde and subjected to immunocytochemistry with glial and macrophage markers. Confluent glial cultures that received meningeal cells showed several cell-free holes in each well. With longer incubation time, holes jointed to form large surfaces without cells but preserving the rounded morphology. Pure astrocytes cultures exhibit larger holes compared with mixed glia cultures. A detailed study on the border of cell-free holes showed that a thick layer of astrocytes formed a barrier separating the cell-free area and the confluent glia. Beyond the barrier, the astroglial monolayer showed stellated reactive astrocytes. Immunocytochemistry showed that astrocytes forming the barrier were highly expressing GFAP, S100B and toll-like receptor 4 (TLR), resembling glial scar forming astrocytes in vivo. In the center of each hole, isolated tomato lectin and TLR positive cells were detected. We conclude that meningeal cells have the ability of inducing in vitro scar like structures in the confluent astrocytic monolayer, probably by secretion of soluble mediators or extracellular matrix components that repel astrocytes. Astrocytes receiving these factors migrate away until forming a compact barrier structure that resembles glial scar observed in vivo after focal brain damage.