In:
The Journal of Neuroscience, Society for Neuroscience, Vol. 27, No. 18 ( 2007-05-02), p. 4947-4956
Abstract:
We generated mice with doxycycline control of a human neurofilament light (NF-L) transgene in the context of the absence (tTA;hNF-L;NF-L −/− ) or presence (tTA;hNF-L;NF-L +/− ) of endogenous mouse NF-L proteins. Doxycycline treatment caused the rapid disappearance of human NF-L (hNF-L) mRNA in tTA;hNF-L mice, but the hNF-L proteins remained with a half-life of 3 weeks in the brain. In the sciatic nerve, the disappearance of hNF-L proteins after doxycycline treatment occurred in synchrony along the sciatic nerve, suggesting a proteolysis of NF proteins along the entire axon. The presence of permanent NF network in tTA;hNF-L;NF-L +/− mice further stabilized and extended longevity of hNF-L proteins by several months. Surprisingly, after cessation of doxycycline treatment, there was no evidence of leading front of newly synthesized hNF-L proteins migrating into sciatic nerve axons devoid of NF structures. The hNF-L proteins detected at weekly intervals reappeared and accumulated in synchrony at similar rate along nerve segments, a phenomenon consistent with a fast hNF-L transport into axons. We estimated the hNF-L transport rate to be of ∼10 mm/d in axons devoid of NF structures based on the use of an adenovirus encoding tet-responsive transcriptional activator to transactivate the hNF-L transgene in hypoglossal motor neurons. These results provide in vivo evidence that the stationary NF network in axons is a key determinant of half-life and transport rate of NF proteins.
Type of Medium:
Online Resource
ISSN:
0270-6474
,
1529-2401
DOI:
10.1523/JNEUROSCI.5299-06.2007
Language:
English
Publisher:
Society for Neuroscience
Publication Date:
2007
detail.hit.zdb_id:
1475274-8
SSG:
12
