PMID- 26371871
OWN - NLM
STAT- MEDLINE
DCOM- 20160617
LR  - 20220408
IS  - 1607-8888 (Electronic)
IS  - 1025-3890 (Linking)
VI  - 18
IP  - 6
DP  - 2015
TI  - Glucocorticoids retard skeletal muscle development and myoblast protein synthesis 
      through a mechanistic target of rapamycin (mTOR)-signaling pathway in broilers 
      (Gallus gallus domesticus).
PG  - 686-98
LID - 10.3109/10253890.2015.1083551 [doi]
AB  - Glucocorticoids exert a well-known catabolic protein action on skeletal muscle. 
      The mechanistic target of rapamycin (mTOR) signaling pathway acts as a central 
      regulator of protein metabolism. Whether glucocorticoids regulate protein 
      synthesis through the mTOR pathway in skeletal muscle of chickens remains 
      unknown. This study was performed to characterize the effect of glucocorticoids 
      on the mTOR pathway in skeletal muscle development in chickens, and on protein 
      synthesis in cultured embryonic myoblasts. Male 29-d-old chickens were given a 
      dexamethasone injection (2 mg/kg) twice per day for 4 d (n = 16). Chicken 
      embryonic myoblasts were exposed to dexamethasone for 24 h (100 micromol/L, n = 4 
      cultures). The interaction between dexamethasone and leucine was also 
      investigated. ANOVA and Duncan's multiple test were used to analyze the effects 
      of the dexamethasone and leucine treatments. The results showed that 
      dexamethasone decreased body weight gain, body weight, and feed efficiency. 
      Protein synthesis was inhibited by in vitro dexamethasone exposure. 
      Phosphorylation of mTOR and ribosomal protein S6 protein kinase (p70S6K) were 
      inhibited by dexamethasone, suggesting the mTOR pathway may be involved in 
      dexamethasone-regulated muscle protein synthesis. Phosphorylation of 
      AMP-activated protein kinase (AMPK) was not altered in vitro but was reduced in 
      vivo by dexamethasone. These results imply that the mTOR and AMPK pathways are 
      both involved in retarding muscle development and protein synthesis by 
      glucocorticoids, but the mTOR pathway is a critical point linking glucocorticoid 
      and protein synthesis. Leucine, at least partially, inhibited the effects of 
      dexamethasone on protein synthesis via the mTOR pathway.
FAU - Wang, Xiaojuan
AU  - Wang X
AD  - a Department of Animal Science , Shandong Agricultural University , Taian , 
      Shandong , PR China.
FAU - Jia, Qing
AU  - Jia Q
AD  - a Department of Animal Science , Shandong Agricultural University , Taian , 
      Shandong , PR China.
FAU - Xiao, Jingjing
AU  - Xiao J
AD  - a Department of Animal Science , Shandong Agricultural University , Taian , 
      Shandong , PR China.
FAU - Jiao, Hongchao
AU  - Jiao H
AD  - a Department of Animal Science , Shandong Agricultural University , Taian , 
      Shandong , PR China.
FAU - Lin, Hai
AU  - Lin H
AD  - a Department of Animal Science , Shandong Agricultural University , Taian , 
      Shandong , PR China.
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20150915
PL  - England
TA  - Stress
JT  - Stress (Amsterdam, Netherlands)
JID - 9617529
RN  - 0 (Glucocorticoids)
RN  - 7S5I7G3JQL (Dexamethasone)
RN  - EC 2.7.11.1 (Protein Serine-Threonine Kinases)
RN  - EC 2.7.11.1 (TOR Serine-Threonine Kinases)
RN  - EC 2.7.11.31 (AMP-Activated Protein Kinases)
RN  - W36ZG6FT64 (Sirolimus)
SB  - IM
MH  - AMP-Activated Protein Kinases/metabolism
MH  - Animals
MH  - Chickens
MH  - Dexamethasone/*pharmacology
MH  - Glucocorticoids/*pharmacology
MH  - Male
MH  - Muscle Development/*drug effects
MH  - Muscle, Skeletal/drug effects/metabolism
MH  - Myoblasts/*drug effects/metabolism
MH  - Phosphorylation/drug effects
MH  - Protein Serine-Threonine Kinases/metabolism
MH  - Signal Transduction/*drug effects
MH  - Sirolimus
MH  - TOR Serine-Threonine Kinases/*metabolism
OTO - NOTNLM
OT  - Chickens
OT  - dexamethasone
OT  - leucine
OT  - muscle development
OT  - protein metabolism
OT  - signal pathway
EDAT- 2015/09/16 06:00
MHDA- 2016/06/18 06:00
CRDT- 2015/09/16 06:00
PHST- 2015/09/16 06:00 [entrez]
PHST- 2015/09/16 06:00 [pubmed]
PHST- 2016/06/18 06:00 [medline]
AID - 10.3109/10253890.2015.1083551 [doi]
PST - ppublish
SO  - Stress. 2015;18(6):686-98. doi: 10.3109/10253890.2015.1083551. Epub 2015 Sep 15.