Cytosolic prion protein induces apoptosis in human neuronal cell SH-SY5Y via mitochondrial disruption pathway.
Different neurodegenerative disorders like prion disease, is caused by protein misfolding conformers. Reverse-transfected cytosolic prion protein (PrP) and PrP expressed in the cytosol have been shown to be neurotoxic. To investigate the possible mechanism of neurotoxicity due to accumulation of PrP in cytosol, a PrP mutant lacking the signal and GPI (CytoPrP) was introduced into the SH-SY5Y cell. MTT and trypan blue assays indicated that the viability of cells expressing CytoPrP was remarkably reduced after treatment of MG-132. Obvious apoptosis phenomena were detected in the cells accumulated with CytoPrP, including loss of mitochondrial transmembrane potential, increase of caspase-3 activity, more annexin V/PI-double positive-stained cells and reduced Bcl-2 level. Moreover, DNA fragmentation and TUNEL assays also revealed clear evidences of late apoptosis in the cells accumulated CytoPrP. These data suggest that the accumulation of CytoPrP in cytoplasm may trigger cell apoptosis, in which mitochondrial relative apoptosis pathway seems to play critical role.
Wang
Xin
X
State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Ying-Xin Rd 100, Beijing 100052, China.
Dong
Chen-Fang
CF
Shi
Qi
Q
Shi
Song
S
Wang
Gui-Rong
GR
Lei
Yan-Jun
YJ
Xu
Kun
K
An
Run
R
Chen
Jian-Ming
JM
Jiang
Hui-Ying
HY
Tian
Chan
C
Gao
Chen
C
Zhao
Yu-Jun
YJ
Han
Jun
J
Dong
Xiao-Ping
XP
D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D002460:Cell Line; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D003600:Cytosol / Q000378:metabolism; D006801:Humans; D007976:Leupeptins / Q000494:pharmacology; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D009474:Neurons / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D011328:Prions / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D014162:Transfection
D015853:Cysteine Proteinase Inhibitors; D007976:Leupeptins; D011328:Prions; D019253:Proto-Oncogene Proteins c-bcl-2; C072553:benzyloxycarbonylleucyl-leucyl-leucine aldehyde