miR-487b, miR-3963 and miR-6412 delay myogenic differentiation in mouse myoblast-derived C2C12 cells.
BACKGROUND
Skeletal muscle differentiation is a multistep, complex pathway in which several important signaling molecules are involved. Recently, microRNAs (miRNAs), endogenous non-coding small RNAs that regulate mRNAs, have been proposed to be involved in skeletal muscle differentiation. In this study, we identified skeletal muscle differentiation-associated miRNAs by comparing miRNA expression profiles between C2C12 cells and Wnt4 over-expressing C2C12 cells (W4-08), which can spontaneously differentiate into myotubes.


RESULTS
We identified miR-206, miR-133a, and miR-133b as up-regulated miRNAs and miR-487b, miR-3963 and miR-6412 as down-regulated miRNAs in differentiating cells. We focused on the down-regulated miRNAs because their functions were largely unknown. Transfection of mimics of these miRNAs into C2C12 cells resulted in significantly reduced expression of myogenic differentiation markers, including troponin T and myosin heavy chain fast type and slow type, but did not affect the expression of the myogenic transcription factors, MyoD and myogenin.


CONCLUSIONS
These miRNAs were characterized as new myogenic differentiation-associated miRNAs which may delay late myogenic differentiation or maturation.
Department of Molecular and Developmental Biology, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama, 701-0192, Japan. katase@med.kawasaki-m.ac.jp.
Naoki
N
Katase
Department of Molecular and Developmental Biology, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama, 701-0192, Japan. terarin@med.kawasaki-m.ac.jp.
Kumiko
K
Terada
Department of Molecular and Developmental Biology, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama, 701-0192, Japan. takahe0302@med.kawasaki-m.ac.
Takahiro
T
Suzuki
Department of Molecular and Developmental Biology, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama, 701-0192, Japan. jpshin@med.kawasaki-m.ac.jp.
Shin-ichiro
S
Nishimatsu
Department of Molecular and Developmental Biology, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama, 701-0192, Japan. nohno@bcc.kawasaki-m.ac.jp.
Tsutomu
T
Nohno
D000818:Animals; D002454:Cell Differentiation; D002460:Cell Line; D015536:Down-Regulation; D051379:Mice; D035683:MicroRNAs / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D017570:MyoD Protein / Q000378:metabolism; D032446:Myoblasts / Q000166:cytology / Q000378:metabolism; D018008:Myogenin / Q000378:metabolism; D018995:Myosin Heavy Chains / Q000378:metabolism; D016376:Oligonucleotides, Antisense / Q000378:metabolism; D014162:Transfection; D020107:Troponin T / Q000378:metabolism; D015854:Up-Regulation; D060528:Wnt4 Protein / Q000235:genetics / Q000378:metabolism
D035683:MicroRNAs; D017570:MyoD Protein; D018008:Myogenin; D016376:Oligonucleotides, Antisense; D020107:Troponin T; D060528:Wnt4 Protein; D018995:Myosin Heavy Chains