TY - JOUR
T1 - Reactive oxygen species upregulate expression of muscle atrophy-associated ubiquitin ligase Cbl-b in rat L6 skeletal muscle cells
AU - Uchida, Takayuki
AU - Sakashita, Yoshihiro
AU - Kitahata, Kanako
AU - Yamashita, Yui
AU - Tomida, Chisato
AU - Kimori, Yuki
AU - Komatsu, Akio
AU - Hirasaka, Katsuya
AU - Ohno, Ayako
AU - Nakao, Reiko
AU - Higashitani, Atsushi
AU - Higashibata, Akira
AU - Ishioka, Noriaki
AU - Shimazu, Toru
AU - Kobayashi, Takeshi
AU - Okumura, Yuushi
AU - Choi, Inho
AU - Oarada, Motoko
AU - Mills, Edward M.
AU - Teshima-Kondo, Shigetada
AU - Takeda, Shin’ichi
AU - Tanaka, Eiji
AU - Tanaka, Keiji
AU - Sokabe, Masahiro
AU - Nikawa, Takeshi
N1 - Funding Information:
This study was supported primarily by the International Space Experiment Announcement for Space Utilization promoted by the Japan Aerospace Exploration Agency and the Japan Space Forum. In addition, it was partially supported by grants-in-aid for Scientific Research from the Ministry of Education, Culture, Sports, Science, and Technology of Japan (15H04960 and 16H01645) (to T. Nikawa) and by the Japanese Council for Science, Technology, and Innovation Program (14533567) “Technologies for Creating Next-Generation Agriculture, Forestry and Fisheries” (funding agency: Bio-Oriented Technology Research Advancement Institution) (to T. Nikawa).
Publisher Copyright:
© 2018 American Physiological Society. All rights reserved.
PY - 2018/6
Y1 - 2018/6
N2 - Unloading-mediated muscle atrophy is associated with increased reactive oxygen species (ROS) production. We previously demonstrated that elevated ubiquitin ligase casitas B-lineage lymphoma-b (Cbl-b) resulted in the loss of muscle volume (Nakao R, Hirasaka K, Goto J, Ishidoh K, Yamada C, Ohno A, Okumura Y, Nonaka I, Yasutomo K, Baldwin KM, Kominami E, Higashibata A, Nagano K, Tanaka K, Yasui N, Mills EM, Takeda S, Nikawa T. Mol Cell Biol 29: 4798–4811, 2009). However, the pathological role of ROS production associated with unloading-mediated muscle atrophy still remains unknown. Here, we showed that the ROS-mediated signal transduction caused by microgravity or its simulation contributes to Cbl-b expression. In L6 myotubes, the assessment of redox status revealed that oxidized glutathione was increased under microgravity conditions, and simulated microgravity caused a burst of ROS, implicating ROS as a critical upstream mediator linking to downstream atrophic signaling. ROS generation activated the ERK1/2 early-growth response protein (Egr)1/2-Cbl-b signaling pathway, an established contributing pathway to muscle volume loss. Interestingly, antioxidant treatments such as N-acetyl-cysteine and TEMPOL, but not catalase, blocked the clinorotation-mediated activation of ERK1/2. The increased ROS induced transcrip-tional activity of Egr1 and/or Egr2 to stimulate Cbl-b expression through the ERK1/2 pathway in L6 myoblasts, since treatment with Egr1/2 siRNA and an ERK1/2 inhibitor significantly suppressed clinorotation-induced Cbl-b and Egr expression, respectively. Promoter and gel mobility shift assays revealed that Cbl-b was upregulated via an Egr consensus oxidative responsive element at-110 to-60 bp of the Cbl-b promoter. Together, this indicates that under microgravity conditions, elevated ROS may be a crucial mechano-transducer in skeletal muscle cells, regulating muscle mass through Cbl-b expression activated by the ERK-Egr signaling pathway.
AB - Unloading-mediated muscle atrophy is associated with increased reactive oxygen species (ROS) production. We previously demonstrated that elevated ubiquitin ligase casitas B-lineage lymphoma-b (Cbl-b) resulted in the loss of muscle volume (Nakao R, Hirasaka K, Goto J, Ishidoh K, Yamada C, Ohno A, Okumura Y, Nonaka I, Yasutomo K, Baldwin KM, Kominami E, Higashibata A, Nagano K, Tanaka K, Yasui N, Mills EM, Takeda S, Nikawa T. Mol Cell Biol 29: 4798–4811, 2009). However, the pathological role of ROS production associated with unloading-mediated muscle atrophy still remains unknown. Here, we showed that the ROS-mediated signal transduction caused by microgravity or its simulation contributes to Cbl-b expression. In L6 myotubes, the assessment of redox status revealed that oxidized glutathione was increased under microgravity conditions, and simulated microgravity caused a burst of ROS, implicating ROS as a critical upstream mediator linking to downstream atrophic signaling. ROS generation activated the ERK1/2 early-growth response protein (Egr)1/2-Cbl-b signaling pathway, an established contributing pathway to muscle volume loss. Interestingly, antioxidant treatments such as N-acetyl-cysteine and TEMPOL, but not catalase, blocked the clinorotation-mediated activation of ERK1/2. The increased ROS induced transcrip-tional activity of Egr1 and/or Egr2 to stimulate Cbl-b expression through the ERK1/2 pathway in L6 myoblasts, since treatment with Egr1/2 siRNA and an ERK1/2 inhibitor significantly suppressed clinorotation-induced Cbl-b and Egr expression, respectively. Promoter and gel mobility shift assays revealed that Cbl-b was upregulated via an Egr consensus oxidative responsive element at-110 to-60 bp of the Cbl-b promoter. Together, this indicates that under microgravity conditions, elevated ROS may be a crucial mechano-transducer in skeletal muscle cells, regulating muscle mass through Cbl-b expression activated by the ERK-Egr signaling pathway.
KW - Egr
KW - ROS
KW - Rat L6 cells
KW - Ubiquitin ligase Cbl-b
KW - Unloading-mediated muscle atrophy
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U2 - 10.1152/ajpcell.00184.2017
DO - 10.1152/ajpcell.00184.2017
M3 - Article
C2 - 29513566
AN - SCOPUS:85048170146
SN - 0363-6143
VL - 314
SP - C721-C731
JO - American Journal of Physiology - Cell Physiology
JF - American Journal of Physiology - Cell Physiology
IS - 6
ER -