An 8.5-kb segment of the PMP22 promoter responds to loss of axon signals during Wallerian degeneration, but does not respond to specific axonal signals during nerve regeneration.
Altered expression of the PMP22 gene causes Charcot-Marie-Tooth disease type 1A (CMT1A) and hereditary neuropathy with liability to pressure palsies (HNPP). We have examined the promoter activity of 8.5 kb upstream of the first coding exon of the rat peripheral myelin protein-22 (rPmp22) gene in transgenic mice. We found that the -8.5 kb rPmp22/chloramphenicol acetyl transferase (CAT)/beta-galactosidase (lacZ) construct directs reporter gene expression in a weakly developmental and tissue-specific pattern, consistent with the expression pattern of the endogenous Pmp22 gene. The -8.5 kb rPmp22/CAT/lacZ transgene responds to loss of axonal signals during Wallerian degeneration but unlike the endogenous Pmp22 gene, the transgene fails to respond to axonal signals during nerve regeneration after a sciatic nerve crush injury. In conclusion, the function of the -8.5 kb rPmp22/CAT/lacZ transgene suggests that there are separable regulatory elements in the rPmp22 gene that respond differently to axonal signals received by Schwann cells during nerve development, and during remyelination.
Orfali
Wayel
W
Department of Pathology, Baylor College of Medicine, Houston, Texas 77030, USA.
Nicholson
Robert N
RN
Guiot
Marie-Christine
MC
Peterson
Alan C
AC
Snipes
G Jackson
GJ
D000818:Animals; D001369:Axons / Q000378:metabolism*; D015139:Blotting, Southern; D015870:Gene Expression; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D051379:Mice; D008822:Mice, Transgenic; D009185:Myelin Proteins / Q000235:genetics* / Q000378:metabolism*; D009409:Nerve Crush; D009416:Nerve Regeneration / Q000502:physiology*; D011401:Promoter Regions, Genetic; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012583:Schwann Cells / Q000378:metabolism; D012584:Sciatic Nerve / Q000254:growth & development / Q000378:metabolism; D014855:Wallerian Degeneration / Q000378:metabolism*
D009185:Myelin Proteins; C489546:Pmp22 protein, rat