Electrical stimulation and testosterone differentially enhance expression of regeneration-associated genes. Journal Article

Authors: Sharma, N; Marzo, S. J.; Jones, K. J.; Foecking, E. M.
Article Title: Electrical stimulation and testosterone differentially enhance expression of regeneration-associated genes.
Abstract: As functional recovery following peripheral nerve injury is dependent upon successful repair and regeneration, treatments that enhance different regenerative events may be advantageous. Using a rat facial nerve crush axotomy model, our lab has previously investigated the effects of a combinatorial treatment strategy, consisting of electrical stimulation (ES) of the proximal nerve stump and testosterone propionate (TP) administration. Results indicated that the two treatments differentially enhance facial nerve regenerative properties, whereby ES reduced the delay before sprout formation, TP accelerated the overall regeneration rate, and the combinatorial treatment had additive effects. To delineate the molecular mechanisms underlying such treatments, the present study investigated the effects of ES and TP on expression of specific regeneration-associated genes. Following a right facial nerve crush at the stylomastoid foramen, gonadectomized adult male rats were administered only ES, only TP, a combination of both, or left untreated. Real time RT-PCR analysis was used to assess fold changes in mRNA levels in the facial motor nucleus at 0 h, 6 h, 1 d, 2 d, 7 d, and 21 d post-axotomy. The candidate genes analyzed included two tubulin isoforms (alpha(1)-tubulin and beta(II)-tubulin), 43-kiloDalton growth-associated protein (GAP-43), brain derived neurotrophic factor (BDNF), pituitary adenylate cyclase-activating peptide (PACAP), and neuritin (candidate plasticity-related gene 15). The two treatments have differential effects on gene expression, with ES leading to early but transient upregulation and TP producing late but steady increases in mRNA levels. In comparison to individual treatments, the combinatorial treatment strategy has the most enhanced effects on the transcriptional program activated following injury. Copyright 2009 Elsevier Inc. All rights reserved.
Journal Title: Experimental neurology
Volume: 223
Issue: 1
ISSN: 1090-2430
Publisher: Unknown  
Journal Place: United States
Date Published: 2010
Start Page: 183
End Page: 191
Language: English
Notes: ID: 6297; Record Owner: From MEDLINE, a database of the U.S. National Library of Medicine.; Status: MEDLINE; Publishing Model: Journal available in: Print-Electronic Citation processed from: Internet; NLM Journal Code: eqf, 0370712; CAS Registry/EC Number/Name of Substance: 0 (Androgens). 0 (Brain-Derived Neurotrophic Factor). 0 (GAP-43 Protein). 0 (Pituitary Adenylate Cyclase-Activating Polypeptide). 0 (Protein Isoforms). 0 (RNA, Messenger). 0 (Tubulin). 57-85-2 (Testosterone Propionate).; Electronic Date of Publication: 20090507; Entry Date: 20100416
LUC Authors
  1. Sam Joseph Marzo
    16 Marzo
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