Role of GSK-3beta activity in motor neuronal cell death induced by G93A or A4V mutant hSOD1 gene.
Point mutations such as G93A and A4V in the human Cu/Zn-superoxide dismutase gene (hSOD1) cause familial amyotrophic lateral sclerosis (fALS). In spite of several theories to explain the pathogenic mechanisms, the mechanism remains largely unclear. Increased activity of glycogen synthase kinase-3 (GSK-3) has recently been emphasized as an important pathogenic mechanism of neurodegenerative diseases, including Alzheimer's disease and ALS. To investigate the effects of G93A or A4V mutations on the phosphatidylinositol-3-kinase (PI3-K)/Akt and GSK-3 pathway as well as the caspase-3 pathway, VSC4.1 motoneuron cells were transfected with G93A- or A4V-mutant types of hSOD1 (G93A and A4V cells, respectively) and, 24 h after neuronal differentiation, their viability and intracellular signals, including PI3-K/Akt, GSK-3, heat shock transcription factor-1 (HSTF-1), cytochrome c, caspase-3 and poly(ADP-ribose) polymerase (PARP), were compared with those of wild type (wild cells). Furthermore, to elucidate the role of the GSK-3beta-mediated cell death mechanism, alterations of viability and intracellular signals in those mutant motoneurons were investigated after treating the cells with GSK-3beta inhibitor. Compared with wild cells, viability was greatly reduced in the G93A and A4V cells. However, the treatment of G93A and A4V cells with GSK-3beta inhibitor increased their viability by activating HSTF-1 and by reducing cytochrome c release, caspase-3 activation and PARP cleavage. However, the treatment did not affect the expression of PI3-K/Akt and GSK-3beta. These results suggest that the G93A or A4V mutations inhibit PI3-K/Akt and activate GSK-3beta and caspase-3, thus becoming vulnerable to oxidative stress, and that the GSK-3beta-mediated cell death mechanism is important in G93A and A4V cell death.
Koh
Seong-Ho
SH
Department of Neurology, Institute of Biomedical Science, College of Medicine, Hanyang University, #17 Haengdang-dong, Seongdong-gu, Seoul, 133-791, Korea. kimsh1@hanyang.ac.kr
Lee
Young-Bae
YB
Kim
Kyung S
KS
Kim
Hyun-Jung
HJ
Kim
Manho
M
Lee
Young Joo
YJ
Kim
Juhan
J
Lee
Kwang Woo
KW
Kim
Seung Hyun
SH
D000409:Alanine / Q000235:genetics; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western / Q000379:methods; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects / Q000235:genetics; D002454:Cell Differentiation; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D024161:Collagen Type XI / Q000378:metabolism; D045304:Cytochromes c / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D038362:Glycogen Synthase Kinase 3 / Q000037:antagonists & inhibitors / Q000502:physiology*; D000071679:Glycogen Synthase Kinase 3 beta; D006360:Heat-Shock Proteins / Q000378:metabolism; D006801:Humans; D006822:Hybrid Cells; D007211:Indoles / Q000378:metabolism; D009046:Motor Neurons / Q000187:drug effects / Q000502:physiology*; D016296:Mutagenesis / Q000502:physiology; D009447:Neuroblastoma; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D017354:Point Mutation / Q000235:genetics*; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D013482:Superoxide Dismutase / Q000235:genetics* / Q000502:physiology; D013778:Tetrazolium Salts; D013844:Thiazoles; D013997:Time Factors; D014162:Transfection / Q000379:methods; D014343:Trypan Blue; D014633:Valine / Q000235:genetics
D000409:Alanine; D053148:Caspase 3; D020169:Caspases; D024161:Collagen Type XI; D045304:Cytochromes c; D004791:Enzyme Inhibitors; D038362:Glycogen Synthase Kinase 3; D000071679:Glycogen Synthase Kinase 3 beta; D006360:Heat-Shock Proteins; D007211:Indoles; D019869:Phosphatidylinositol 3-Kinases; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D051057:Proto-Oncogene Proteins c-akt; D013482:Superoxide Dismutase; D013778:Tetrazolium Salts; D013844:Thiazoles; D014343:Trypan Blue; D014633:Valine; C499319:COL11A2 protein, human; C007293:DAPI; C109415:SOD1 G93A protein; C499320:PARP1 protein, human; C494918:AKT1 protein, human; C000605506:GSK3B protein, human; C505407:CASP3 protein, human; C022616:thiazolyl blue