Acetylcholine promotes ROS detoxification against hypoxia/reoxygenation-induced oxidative stress through FoxO3a/PGC-1α dependent superoxide dismutase.
OBJECTIVE
Acetylcholine (ACh) is known to modulate the cardiac redox environment and thereby suppress reactive oxygen species (ROS) generation during oxidative stress. However, there is little information about its regulation on ROS clearance. Here we investigate the beneficial effects of ACh on superoxide dismutase (SOD) as key ROS-detoxifying enzyme system in cultured rat cardiomyoblasts.


METHODS
H9c2 cells were subjected to hypoxia/reoxygenation (H/R) to mimic oxidative stress. Western blot was used to detect the expression of SOD and related signaling molecules. Specific protein knockdown was performed with siRNA transfection.


RESULTS
ACh treatment on the beginning of reoxygenation decreased ROS and apoptosis. ACh increased ATP synthesis and mitochondrial DNA. Furthermore, ACh significantly reversed H/R-induced reduction in protein expressions and activities of SOD. ACh stimulated peroxisome proliferator activated receptor γ co-activator 1α (PGC-1α) and decreased forkhead box subfamily O3a (FoxO3a) phosphorylation. Atropine (muscarinic receptor antagonist) abolished the cytoprotection afforded by ACh. PGC-1α siRNA blocked ACh-induced invigorating effects on SOD2, whereas it did not alter SOD1 and FoxO3a phosphorylation. FoxOSa siRNA drastically decreased the expressions of SOD2 and PGC-1α, while it did not affect SOD1.


CONCLUSIONS
ACh activates SOD2 within mitochondria through FoxO3a/PGC-1α pathway and up-regulates SOD1 in the cytoplasm, thus protecting against oxidative injury induced by H/R. Our findings provide new insights into mechanisms underlying the cardioprotection of ACh on ROS detoxifying.
Department of Pharmacology, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, P.R. China.
Lei
L
Sun
Wei-Jin
WJ
Zang
Hao
H
Wang
Mei
M
Zhao
Xiao-Jiang
XJ
Yu
Xi
X
He
Yi
Y
Miao
Jun
J
Zhou
D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002460:Cell Line; D019610:Cytoprotection / Q000187:drug effects; D000071316:Forkhead Box Protein O3; D051858:Forkhead Transcription Factors / Q000378:metabolism*; D000860:Hypoxia / Q000378:metabolism*; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D032386:Myoblasts, Cardiac / Q000187:drug effects / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects*; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D010766:Phosphorylation / Q000187:drug effects; D020011:Protective Agents / Q000494:pharmacology; D034741:RNA, Small Interfering / Q000235:genetics; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D013482:Superoxide Dismutase / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*
C499515:FOXO3 protein, rat; D000071316:Forkhead Box Protein O3; D051858:Forkhead Transcription Factors; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; C501429:Ppargc1a protein, rat; D020011:Protective Agents; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species; D014157:Transcription Factors; D013482:Superoxide Dismutase; D000109:Acetylcholine