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TrkB expression at the neuromuscular junction is reduced during aging
Author(s) -
Personius Kirkwood E.,
Parker Sara D.
Publication year - 2013
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.23616
Subject(s) - tropomyosin receptor kinase b , neuromuscular junction , medicine , acetylcholine receptor , biology , endocrinology , receptor , neuroscience , neurotrophic factors
: Full‐length tyrosine kinase B (TrkB.FL) and truncated TrkB (TrkB.t1) receptors are colocalized with acetylcholine receptors (AChRs) at the neuromuscular junction. We have recently shown that reduced TrkB expression leads to age‐related alterations in AChR structure, neurotransmission failure, and muscle weakness. Methods : We investigated whether TrkB expression is reduced in the soleus muscle during aging. Results : TrkB protein expression was decreased in senescent (24‐month‐old) compared with 3–12‐month‐old mice. Loss of TrkB expression was concurrent with age‐related changes in AChR morphology. Changes in mRNA levels did not correlate with protein expression, because TrkB.FL copy number was increased in the senescent soleus. No change was seen in TrkB.t1 levels. Conclusions : The results suggest that reduced TrkB expression during aging may result from reduced TrkB.FL mRNA translation or increased TrkB protein turnover. Thus, maintaining adequate TrkB signaling is a potential therapeutic tool to improve muscle function during senescence. Muscle Nerve 47: 532–538, 2013