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

Abstract

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.