Bcl-2 enhances neurogenesis and inhibits apoptosis of newborn neurons in adult rat brain following a transient middle cerebral artery occlusion

To determine whether Bel-2 could influence adult neurogenesis and prevent apoptosis of newborn neurons, we injected Bel-2 expressing plasmid into the lateral ventricle of rat brain immediately following a 30-min occlusion of the middle cerebral artery (MCAO). We found that Bel-2 increased neural progenitor cells (BrdU(+)-DCX+) in the ipsilateral striatum, newborn immature neurons (BrdU(+)-Tuj-1(+)) and newborn mature neurons (BrdU(+)-MAP-2(+)) in the ipsilateral striatum and frontal cortex at 1 to 4 weeks following MCAO. Bcl-2 overexpression promoted development of newborn neurons into GABAergic and cholinergic neurons in the ipsilateral striatum. Moreover, Bcl-2 significantly decreased the apoptosis of newborn neurons, determined by double staining of Tuj-1 and activated caspase-3 (Tuj-1(+)-Casp(+)). These results indicate that overexpression of Bcl-2 in adult rat brain enhances neurogenesis and survival of newborn neurons. Increasing neurogenesis and preventing the death of newborn neuron may be a strategy to aid in the repair of adult brain after stroke. (c) 2006 Elsevier Inc. All rights reserved.