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Skeletal muscle cell activation by low‐energy laser irradiation: A role for the MAPK/ERK pathway
Author(s) -
Shefer Gavriela,
Oron Uri,
Irintchev Andrey,
Wernig Anton,
Halevy Orna
Publication year - 2001
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/1097-4652(2001)9999:9999<::aid-jcp1053>3.0.co;2-9
Subject(s) - mapk/erk pathway , phosphorylation , p38 mitogen activated protein kinases , microbiology and biotechnology , protein kinase a , kinase , hepatocyte growth factor , biology , skeletal muscle , chemistry , receptor , endocrinology , biochemistry
Low‐energy laser irradiation (LELI) has been shown to promote skeletal muscle regeneration in vivo and to activate skeletal muscle satellite cells, enhance their proliferation and inhibit differentiation in vitro. In the present study, LELI, as well as the addition of serum to serum‐starved myoblasts, restored their proliferation, whereas myogenic differentiation remained low. LELI induced mitogen‐activated protein kinase/extracellular signal‐regulated protein kinase (MAPK/ERK) phosphorylation with no effect on its expression in serum‐starved myoblasts. Moreover, a specific MAPK kinase inhibitor (PD098059) inhibited the LELI‐ and 10% serummediated ERK1/2 activation. However, LELI did not affect Jun N‐terminal kinase (JNK) or p38 MAPK phosphorylation or protein expression. Whereas a 3‐sec irradiation induced ERK1/2 phosphorylation, a 12‐sec irradiation reduced it, again with no effect on JNK or p38. Moreover, LELI had distinct effects on receptor phosphorylation: it caused phosphorylation of the hepatocyte growth factor (HGF) receptor, previously shown to activate the MAPK/ERK pathway, whereas no effect was observed on tumor suppressor necrosis α (TNF‐α) receptor which activates the p38 and JNK pathways. Therefore, by specifically activating MAPK/ERK, but not JNK and p38 MAPK enzymes, probably by specific receptor phosphorylation, LELI induces the activation and proliferation of quiescent satellite cells and delays their differentiation. © 2001 Wiley‐Liss, Inc.