TAT-Bcl-XL improves survival of neuronal precursor cells in the lesioned striatum after focal cerebral ischemia

Cerebral ischemia activates endogenous neurogenesis in the subventricular zone (SVZ) and the dentate gyrus. Consecutively, SVZ-derived neural precursors migrate towards ischemic lesions. However, functional relevance of activated neurogenesis is limited by poor survival of new-born precursors. We therefore employed the HI-virus-derived fusion protein TAT-Bcl-X-L to study the effects of acute anti-apoptotic treatment on endogenous neurogenesis and functional outcome after transient cerebral ischemia in mice. TAT-Bcl-XL treatment led to significantly reduced acute ischemic cell death (128 +/- 23 vs. 305 +/- 65 TUNEL+ cells/mm(2) in controls) and infarct volumes resulting in less motor deficits and improved spatial learning. It significantly increased survival of doublecortin (Dcx)-positive neuronal precursors (389 +/- 96 vs. 213 +/- 97 Dcx(+) cells in controls) but did not enhance overall post-ischemic cell proliferation or lesion-specific neuronal differentiation 28 days after ischemia. Our data demonstrate that post-stroke TAT-Bcl-X-L-treatment results in acute neuroprotection, improved functional outcome, and enhanced survival of lesion-specific neuronal precursor cells after cerebral ischemia in mice. (C) 2008 Elsevier Inc. All rights reserved.