PMID- 31081172
OWN - NLM
STAT- MEDLINE
DCOM- 20200817
LR  - 20211204
IS  - 1097-4644 (Electronic)
IS  - 0730-2312 (Linking)
VI  - 120
IP  - 9
DP  - 2019 Sep
TI  - Phosphorylated mTORC1 represses autophagic-related mRNA translation in neurons 
      exposed to ischemia-reperfusion injury.
PG  - 15915-15923
LID - 10.1002/jcb.28865 [doi]
AB  - OBJECTIVES: The sequential reactivation of mechanistic target of rapamycin (mTOR) 
      inhibited autophagic flux in neurons exposed to oxygen-glucose 
      deprivation/reperfusion (OGD/R), which was characterized by reduction of 
      autophagosome formation and restriction of autolysosome degradation. However, its 
      detailed molecular mechanism was still unknown. In this study, we further explore 
      the existing form of mTOR and its suppression on the transcriptional levels of 
      related mRNA from neurons exposed to ischemia-reperfusion injury. METHODS: The 
      OGD/R or middle cerebral artery occlusion/reperfusion (MCAO/R)-treated neurons 
      was used to simulate ischemia/reperfusion injury . Autophagy flux was monitored 
      by means of microtubule-associated protein 1 light chain 3 (LC3) and p62. The 
      reactivation of mTOR was determined by phosphorylation of ribosomal protein S6 
      kinase 1 (S6K1). Then the inhibitors of mTOR were used to confirm its existence 
      form. Finally, the mRNA transcription levels were analyzed to observe the 
      negative regulation of mTOR. RESULTS: The sequential phosphorylation of mTOR 
      contributed to the neuronal autophagy flux blocking. mTOR was re-phosphorylated 
      and existed as mTOR complex 1 (mTORC1), which was supported by phosphorylation of 
      S6K1 at Thr 389 in neurons. In addition, the phosphorylation of S6K1 was 
      decreased roughly by applying mTORC1 inhibitors, rapamycin and torin 1. However, 
      the administration of mTORC1/2 inhibitor PP242 could recover the phosphorylation 
      of S6K1, which suggested that mTORC2 was involved in the regulation of mTORC1 
      activity. In paralleling with reactivation of mTORC1, related mRNA transcription 
      was repressed in neurons under ischemia-reperfusion exposure in vivo and in 
      vitro. The mRNA expression levels of LC3, Stx17, Vamp8, Snap29, Lamp2a, and 
      Lamp2b were decreased in neurons after reperfusion, comparing with 
      ischemia-treated neurons. CONCLUSIONS: The reactivated mTORC1 could suppress the 
      transcription levels of related mRNA, such as LC3, Stx17, Vamp8, Snap29, Lamp2a, 
      and Lamp2b. The research will expand the horizons that mTOR would negatively 
      regulate autophagy at transcription and post-translation levels in neurons 
      suffering ischemia-reperfusion injury.
CI  - (c) 2019 Wiley Periodicals, Inc.
FAU - Hua, Rongrong
AU  - Hua R
AUID- ORCID: 0000-0001-5102-115X
AD  - Department of Neurology, Aviation General Hospital, China Medical University, 
      Beijing, People's Republic of China.
FAU - Wei, Haiping
AU  - Wei H
AD  - Department of Neurology, Second Hospital of Lanzhou University, Lanzhou, People's 
      Republic of China.
FAU - Liu, Chunyan
AU  - Liu C
AD  - Department of Neurology, Aviation General Hospital, China Medical University, 
      Beijing, People's Republic of China.
FAU - Shi, Zhe
AU  - Shi Z
AD  - Department of Neurology, Aviation General Hospital, China Medical University, 
      Beijing, People's Republic of China.
FAU - Xing, Yan
AU  - Xing Y
AD  - Department of Neurology, Aviation General Hospital, China Medical University, 
      Beijing, People's Republic of China.
LA  - eng
PT  - Journal Article
DEP - 20190512
PL  - United States
TA  - J Cell Biochem
JT  - Journal of cellular biochemistry
JID - 8205768
RN  - 0 (Autophagy-Related Proteins)
RN  - EC 2.7.1.1 (mTOR protein, mouse)
RN  - EC 2.7.11.1 (Mechanistic Target of Rapamycin Complex 1)
RN  - EC 2.7.11.1 (Mechanistic Target of Rapamycin Complex 2)
RN  - EC 2.7.11.1 (Ribosomal Protein S6 Kinases, 90-kDa)
RN  - EC 2.7.11.1 (Rps6ka1 protein, mouse)
RN  - EC 2.7.11.1 (TOR Serine-Threonine Kinases)
RN  - W36ZG6FT64 (Sirolimus)
SB  - IM
MH  - Animals
MH  - Autophagy
MH  - Autophagy-Related Proteins/*genetics
MH  - Cells, Cultured
MH  - Disease Models, Animal
MH  - Feedback, Physiological
MH  - Gene Expression Regulation
MH  - Mechanistic Target of Rapamycin Complex 1/*metabolism
MH  - Mechanistic Target of Rapamycin Complex 2/metabolism
MH  - Mice
MH  - Neurons/chemistry/*cytology
MH  - Phosphorylation
MH  - Reperfusion Injury/genetics/*metabolism
MH  - Ribosomal Protein S6 Kinases, 90-kDa/metabolism
MH  - Signal Transduction
MH  - Sirolimus/pharmacology
MH  - TOR Serine-Threonine Kinases/genetics/metabolism
OTO - NOTNLM
OT  - autophagy
OT  - ischemia
OT  - mTOR
OT  - reperfusion
EDAT- 2019/05/14 06:00
MHDA- 2020/08/18 06:00
CRDT- 2019/05/14 06:00
PHST- 2018/12/16 00:00 [received]
PHST- 2019/02/14 00:00 [revised]
PHST- 2019/02/21 00:00 [accepted]
PHST- 2019/05/14 06:00 [pubmed]
PHST- 2020/08/18 06:00 [medline]
PHST- 2019/05/14 06:00 [entrez]
AID - 10.1002/jcb.28865 [doi]
PST - ppublish
SO  - J Cell Biochem. 2019 Sep;120(9):15915-15923. doi: 10.1002/jcb.28865. Epub 2019 
      May 12.