Nestin enhancer requirements for expression in normal and injured adult CNS

The nestin gene is expressed in many CNS stem/progenitor cells, both in the embryo and the adult, and nestin is used commonly as a marker for these cells. In this report we analyze nestin enhancer requirements in the adult CNS, using transgenic mice carrying reporter genes linked to three different nestin enhancer constructs: the genomic rat nestin gene and 5 kb of upstream nestin sequence (NesP lacZ /3), 636 bp of the rat nestin second intron (E/nestin:EGFP), and a corresponding 714 bp region from the human second intron (Nes714tk/ lacZ ). NesP lacZ /3 and E/nestin:EGFP mice showed reporter gene expression in stem cell‐containing regions of brain and spinal cord during normal conditions. NesP lacZ /3 and E/nestin:EGFP mice showed increased expression in spinal cord after injury and NesP lacZ /3 mice displayed elevated expression in the periventricular area of the brain after injury, which was not the case for the E/nestin:EGFP mice. In contrast, no expression in adult CNS in vivo was seen in the Nes714tk/ lacZ mice carrying the human enhancer, neither during normal conditions nor after injury. The Nes714 tk/ lacZ mice, however, expressed the reporter gene in reactive astrocytes and CNS stem cells cultured ex vivo. Collectively, this suggests a species difference for the nestin enhancer function in adult CNS and that elements outside the second intron enhancer are required for the full injury response in vivo. © 2002 Wiley‐Liss, Inc.