A New In Vitro Model Of Glial Scar Induced By Oxygen-Glucose Deprivation

It has been demonstrated that cerebral ischemia induces astrocyte reactivity, and subsequent glial scar formation inhibits axonal regeneration during the recovery phase. Investigating the mechanism of glial scar formation will facilitate the development of strategies to improve axonal regeneration. However, an in vitro model of ischemia-induced glial scar has not yet been systematically established. In the present study, we developed an in vitro model of the ischemia-induced glial scar by oxygen-glucose deprivation (OGD). After OGD for 6 h, astrocytes showed a remarkable proliferation following 24 h reperfusion, evaluated by MTT assay and BrdU immunocytochemistry. Meanwhile, the expressions of glial fibrillary acidic protein and neurocan (hallmarks of the glial scar) were significantly increased. However, phosphacan, another scar-associated protein was reduced at 24 h reperfusion after OGD and recovered to control levels following 72 h reperfusion. In further experiments, neurons were co-cultured with astrocytes exposed to OGD and the expression ofβ-tubulin3 was analyzed to assess neurite growth, which was notably inhibited when the co-culture was performed at 48 h reperfusion of astrocytes. Notably, similar to in vivo studies, the processes of neurons were elongated when the co-culture was performed immediately after OGD. The present model showed the main aspects of the ischemia-induced glial scar, which reflected the acute and chronic phases, and it may be used to explore mechanisms underlying scar formation and treatments to improve axonal regeneration after cerebral ischemia.