Extracellular signal-regulated kinases are not involved in activity-dependent survival or apoptosis in cerebellar granule neurons.
Cerebellar granule neurons (CGNs) depend on potassium depolarization for survival and undergo apoptosis when deprived of depolarizing concentration of potassium. Extracellular signal-regulated kinases (ERK1/2) are thought to be activated in response to potassium depolarization and responsible for the activity-dependent survival in CGNs, but one recent study has revealed that ERK1/2 is activated by potassium deprivation and is required for apoptosis of CGNs. In this study we showed that ERK1/2 was inactivated, rather than activated, by potassium deprivation, indicating a lack of ERK1/2 involvement in potassium deprivation-induced apoptosis. Furthermore, suppression of potassium depolarization-induced activation of ERK1/2 with chemical inhibitor U0126 or PD98059 had no influence on the pro-survival effect of potassium depolarisation. Thus, ERK1/2 was not required for potassium depolarization-dependent survival of CGNs. Taken together, our findings suggest that ERK1/2 is not involved in activity-dependent survival or apoptosis of CGNs.
Song
Bin
B
Department of Pharmacology, Zhongshan Medical College, Sun Yat-Sen University, Guangzhou, China.
Ma
Chi
C
Gong
Shoufang
S
Yuan
Zhongmin
Z
Li
Dan
D
Liu
Wei
W
Li
Wenming
W
Chen
Ruzhu
R
Zhu
Xiaonan
X
Zeng
Jinsheng
J
Han
Yifan
Y
Li
Mingtao
M
D000818:Animals; D000831:Animals, Newborn; D017209:Apoptosis; D002470:Cell Survival; D002531:Cerebellum / Q000166:cytology*; D004789:Enzyme Activation; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism / Q000502:physiology*; D020930:MAP Kinase Kinase Kinases / Q000378:metabolism; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D009474:Neurons / Q000201:enzymology / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley
D048049:Extracellular Signal-Regulated MAP Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020930:MAP Kinase Kinase Kinases