Premium
Calcitonin gene‐related peptide regulation of glial cell‐line derived neurotrophic factor in differentiated rat myotubes
Author(s) -
Rosa Elyse,
Cha Jieun,
Bain James R.,
Fahnestock Margaret
Publication year - 2015
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/jnr.23512
Subject(s) - glial cell line derived neurotrophic factor , calcitonin gene related peptide , neurotrophic factors , gdnf family of ligands , myogenesis , medicine , endocrinology , downregulation and upregulation , neurotrophin , neuromuscular junction , microbiology and biotechnology , biology , myocyte , chemistry , neuropeptide , neuroscience , receptor , biochemistry , gene
Glial cell‐line derived neurotrophic factor (GDNF) is the most potent trophic factor for motoneuron survival and neuromuscular junction formation. GDNF is upregulated in injured or denervated skeletal muscle and returns to normal levels following reinnervation. However, the mechanism by which GDNF is regulated in denervated muscle is not well understood. The nerve‐derived neurotransmitter calcitonin gene‐related peptide (CGRP) is upregulated following neuromuscular injury and is subsequently released from motoneurons at the neuromuscular junction. CGRP also promotes nerve regeneration, but the mechanism is not well understood. The current study investigates whether this increase in CGRP regulates GDNF, thus playing a key role in promoting regeneration of injured nerves. This study demonstrates that CGRP increases GDNF secretion without affecting its transcription or translation. Rat L6 myoblasts were differentiated into myotubes and subsequently treated with CGRP. GDNF mRNA expression levels were quantified by quantitative real‐time reverse transcription‐polymerase chain reaction, and secreted GDNF was quantified in the conditioned medium by ELISA. CGRP treatment increased secreted GDNF protein without altering GDNF mRNA levels. The translational inhibitor cycloheximide did not affect CGRP‐induced GDNF secreted protein levels, whereas the secretional inhibitor brefeldin A blocked the CGRP‐induced increase in GDNF. This study highlights the importance of injury‐induced upregulation of CGRP by exposing its ability to increase GDNF levels and demonstrates a secretional mechanism for regulation of this key regeneration‐promoting neurotrophic factor. © 2014 Wiley Periodicals, Inc.