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Interactions between β ‐neuregulin and neurotrophins in motor neuron apoptosis
Author(s) -
Ricart Karina,
J. Pearson Richard,
Viera Liliana,
Cassina Patricia,
Kamaid Andrés,
Carroll Steven L.,
Estévez Alvaro G.
Publication year - 2006
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.2006.03739.x
Subject(s) - neuregulin , motor neuron , neurotrophin , low affinity nerve growth factor receptor , neurotrophic factors , glial cell line derived neurotrophic factor , neuroscience , nerve growth factor , biology , neuregulin 1 , brain derived neurotrophic factor , tropomyosin receptor kinase b , ciliary neurotrophic factor , neurotrophin 3 , microbiology and biotechnology , receptor , signal transduction , biochemistry , spinal cord
Neuregulins play a major role in the formation and stabilization of neuromuscular junctions, and are produced by both motor neurons and muscle. Although the effects and mechanism of neuregulins on skeletal muscle (e.g. regulation of acetylcholine receptor expression) have been studied extensively, the effects of neuregulins on motor neurons remain unknown. We report that neuregulin‐1β (NRGβ1) inhibited apoptosis of rat motor neurons for up to 7 days in culture by a phosphatidylinositol 3 kinase‐dependent pathway and synergistically enhanced motor neuron survival promoted by glial‐derived neurotrophic factor (GDNF). However, binding of neurotrophins, including brain‐derived neurotrophic factor (BDNF) and nerve growth factor (NGF), to the p75 neurotrophin receptor (p75 NTR ) abolished the neuregulin anti‐apoptotic effect on motor neurons. Inhibitors of the c‐Jun N‐terminal kinase (JNK) mitogen‐activated protein kinase prevented motor neuron death caused by co‐incubation of NRGβ1 and BDNF or NGF, as well as by trophic factor deprivation. Motor neuron apoptosis resulting from both trophic factor deprivation and exposure to NRGβ1 plus neurotrophins required the induction of neuronal nitric oxide synthase and peroxynitrite formation. Because motor neurons express both p75 NTR and neuregulin erbB receptors during the period of embryonic programmed cell death, motor neuron survival may be the result of complex interactions between trophic and death factors, which may be the same molecules acting in different combinations.