Nerve growth factor attenuates 2-deoxy-d-glucose-triggered endoplasmic reticulum stress-mediated apoptosis via enhanced expression of GRP78.
The glucose analog 2-deoxy-d-glucose (2DG) depletes cells of glucose. Inhibition of glycosylation caused by glucose depletion induces endoplasmic reticulum (ER) stress with subsequent apoptosis. Glucose-regulated protein 78 (GRP78) is a molecular chaperone that acts within the ER. During ER stress, GRP78 expression is induced as part of the unfolded protein response (UPR). We found that nerve growth factor (NGF) prevented 2DG-triggered ER stress-mediated apoptosis, but not the induction of GRP78 expression, in PC12 cells. Surprisingly, GRP78 expression was further up-regulated when NGF was added to 2DG-treated PC12 cells. When a specific inhibitor of phosphatidylinositol 3-kinase (PI3-K), LY294002, was added to 2DG plus NGF-treated cells, both the effects of NGF on 2DG-induced apoptosis and GRP78 expression were significantly diminished. In addition, versipelostatin (VST), a specific inhibitor of GRP78 expression, and small interfering RNA (siRNA) against GRP78 mRNA also decreased both the effects of NGF on 2DG-induced apoptosis and GRP78 expression. RT-PCR and Western blot analyses revealed that enhanced production of nuclear p50 ATF6, but not spliced XBP1, mainly contributed to the NGF-induced enhancement of GRP78 expression in 2DG-treated cells. These results suggest that the NGF-activated PI3-K/Akt signaling pathway plays a protective role against ER stress-mediated apoptosis via enhanced expression of GRP78 in PC12 cells.
Kishi
Soichiro
S
Laboratory of Neurobiology, Department of Life Science and Biotechnology, Faculty of Chemistry, Materials and Bioengineering, and Strategic Research Base, Kansai University, 3-3-35 Yamatecho, Suita, Osaka 564-8680, Japan. shimoke@kansai-u.ac.jp
Shimoke
Koji
K
Nakatani
Yosuke
Y
Shimada
Takafumi
T
Okumura
Nobuaki
N
Nagai
Katsuya
K
Shin-Ya
Kazuo
K
Ikeuchi
Toshihiko
T
D000704:Analysis of Variance; D000818:Animals; D000963:Antimetabolites / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D003847:Deoxyglucose / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004721:Endoplasmic Reticulum / Q000187:drug effects*; D000091342:Endoplasmic Reticulum Chaperone BiP; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D020287:In Situ Nick-End Labeling / Q000379:methods; D020932:Nerve Growth Factor / Q000494:pharmacology*; D016716:PC12 Cells / Q000648:ultrastructure; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D000071701:Regulatory Factor X Transcription Factors; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014162:Transfection / Q000379:methods; D015854:Up-Regulation / Q000187:drug effects; D000071717:X-Box Binding Protein 1
D000963:Antimetabolites; D004268:DNA-Binding Proteins; D000091342:Endoplasmic Reticulum Chaperone BiP; D004791:Enzyme Inhibitors; D006360:Heat-Shock Proteins; D012333:RNA, Messenger; D000071701:Regulatory Factor X Transcription Factors; D014157:Transcription Factors; D000071717:X-Box Binding Protein 1; C000605545:Xbp1 protein, rat; D020932:Nerve Growth Factor; D003847:Deoxyglucose