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.