Transcription activation of myostatin by trichostatin A in differentiated C2C12 myocytes via ASK1-MKK3/4/6-JNK and p38 mitogen-activated protein kinase pathways.
Myostatin is a negative regulator of skeletal muscle mass. The pathways employed in modulating myostatin gene expression are scarcely known. We aimed to determine the signaling pathway of myostatin induction by a histone deacetylase (HDAC) inhibitor-trichostatin A (TSA) in differentiated C(2)C(12) myocytes. TSA increased myostatin mRNA expression up to 40-fold after treatment for 24 h, and induced myostatin promoter activity up to 3.8-fold. Pretreatment with actinomycin D reduced the TSA-induced myostatin mRNA by 93%, suggesting TSA-induced myostatin expression mainly at the transcriptional level. Pretreatment with p38 MAPK (SB203580) and JNK (SP600125) inhibitors, but not ERK (PD98059) inhibitor, blocked TSA-induced myostatin expression, respectively, by 72% and 43%. Knockdown of p38 MAPK by RNAi inhibited the TSA-induced myostatin expression by 77% in C(2)C(12) myoblasts. The protein levels of phosphorylated p38 MAPK, JNK, but not ERK, increased with TSA treatment in differentiated C(2)C(12) cells. Direct activation of p38 MAPK and JNK by anisomycin in the absence of TSA increased myostatin mRNA by fourfold. The phosphorylated form of the kinase MKK3/4/6 and ASK1, upstream cascades of p38 MAPK and JNK, also increased with TSA treatment. We concluded that the induction of myostatin by TSA treatment in differentiated C(2)C(12) cells is in part through ASK1-MKK3/6-p38 MAPK and ASK1-MKK4-JNK signaling pathways. Activation of p38 MAPK and JNK axis is necessary, but not sufficient for TSA-induced myostatin expression.
Han
Der-Sheng
DS
Department of Physical Medicine and Rehabilitation, National Taiwan University Hospital BeiHu Branch, Taipei, Taiwan.
Huang
Hsiang-Po
HP
Wang
Tyng-Guey
TG
Hung
Meng-Yu
MY
Ke
Jia-Yu
JY
Chang
Kuei-Ting
KT
Chang
Hsin-Yu
HY
Ho
Yu-Ping
YP
Hsieh
Wei-Yuan
WY
Yang
Wei-Shiung
WS
D000818:Animals; D000935:Antifungal Agents; D002478:Cells, Cultured; D006877:Hydroxamic Acids / Q000494:pharmacology*; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D048371:MAP Kinase Kinase 3 / Q000378:metabolism; D048669:MAP Kinase Kinase 6 / Q000378:metabolism; D048848:MAP Kinase Kinase Kinase 5 / Q000378:metabolism; D020930:MAP Kinase Kinase Kinases / Q000378:metabolism; D051379:Mice; D032342:Muscle Cells / Q000378:metabolism*; D055435:Myostatin / Q000187:drug effects / Q000235:genetics*; D010766:Phosphorylation; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D015398:Signal Transduction; D015533:Transcriptional Activation / Q000187:drug effects*
D000935:Antifungal Agents; D006877:Hydroxamic Acids; D055435:Myostatin; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; C012589:trichostatin A; D048031:JNK Mitogen-Activated Protein Kinases; D048848:MAP Kinase Kinase Kinase 5; D020930:MAP Kinase Kinase Kinases; C482859:Map3k5 protein, mouse; C489843:Map3k8 protein, mouse; D048371:MAP Kinase Kinase 3; D048669:MAP Kinase Kinase 6; C482531:Map2k3 protein, mouse; C482567:Map2k6 protein, mouse