Neurotrophins induce migration of reactive astrocytes

ANDREA BEATRÍZ CRAGNOLINI; GONZALO MONTENEGRO; DANIEL MASCÒ

Congreso; XXVIII Congreso anual de la Sociedad Argentina de Investigación en Neurociencias; 2013

Astrocytes respond to all forms of CNS insults through a process referred to as reactive astrogliosis. Reactive astrocytes are characterized by an increase in proliferation, size, migration to the injured zone and release of a plethora of chemical mediators that includes neurotrophins, such as NGF and BDNF. We have previously demonstrated that a brain injury induces the expression of the neurotrophin receptor p75 on hippocampal astrocytes and mediates the antiproliferative effect of NGF. The goal of this study was to investigate whether neurotrophins and their receptors influence the migration of reactive astrocytes from different brain areas. We used an in vitro scratch-wound assay made on confluent cultures of cortical, hippocampal and striatal astrocytes obtained from neonatal rats. We observed that a scratch lesion increased levels of p75 NTR, but not TrkB, in astrocytes from the three brain areas. When scratched astrocytes were treated with NGF or BDNF we found that striatal astrocytes responded to both neurotrophins by increasing the migration toward the injured area. This effect was blocked by an antibody against p75NTR indicating that this receptor mediates the effect of both neurotrophins on migration. Astrocytes from hippocampus or cortex also increased the migration in response to NGF but not to BDNF. These results are consistent with the idea that neurotrophin may serve to modulate different aspects of gliosis after injury.