Calcium-influx increases SOD1 aggregates via nitric oxide in cultured motor neurons.
Familial amyotrophic lateral sclerosis (fALS) is caused by mutations in Cu/Zn-superoxide dismutase (SOD1), and SOD1 aggregation and calcium toxicity are involved in neuronal death. However, the effect of altered calcium homeostasis on the SOD1 aggregation is unknown. To investigate whether calcium triggers mutant SOD1 aggregation in vitro, human mutant SOD1 (G93A) was transfected into motor neuronal cell line (VSC 4.1 cells). These cells were then treated with calcium ionophore A23187 or agents that induce intracellular calcium release like cyclic ADP ribose, ryanodine or thapsigargin. A23187 was found to increase mutant SOD1 aggregation and neuronal nitric oxide synthase (nNOS) expression. Moreover, the NOS inhibitor (L-NAME) and a NO-dependent cyclic GMP cascade inhibitor (ODQ) reduced SOD1 aggregation, whereas an exogenous NO donor (GSNO) increased mutant SOD1 aggregation, which was also prevented by NOS or cGMP cascade inhibitor. Our data demonstrate that calcium-influx increases SOD1 aggregation by upregulating NO in cultured motor neuronal cells.
Kim
Hyun Jung
HJ
School of Chemical and Biological Engineering, Institute of Chemical Processes, Seoul National University, Seoul 151-741, Korea.
Im
Wooseok
W
Kim
Seungchan
S
Kim
Sung Hun
SH
Sung
Jung Jun
JJ
Kim
Manho
M
Lee
Kwang Woo
KW
D000690:Amyotrophic Lateral Sclerosis / Q000235:genetics / Q000378:metabolism; D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002154:Calpain / Q000378:metabolism; D053148:Caspase 3 / Q000378:metabolism; D002460:Cell Line; D006801:Humans; D007476:Ionophores / Q000494:pharmacology; D009046:Motor Neurons / Q000378:metabolism*; D046912:Multiprotein Complexes; D009154:Mutation; D009569:Nitric Oxide / Q000378:metabolism*; D051381:Rats; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013482:Superoxide Dismutase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000072105:Superoxide Dismutase-1; D014162:Transfection
D007476:Ionophores; D046912:Multiprotein Complexes; D011994:Recombinant Proteins; C000606290:SOD1 protein, human; D009569:Nitric Oxide; D000001:Calcimycin; C000606292:Sod1 protein, rat; D013482:Superoxide Dismutase; D000072105:Superoxide Dismutase-1; D002154:Calpain; C505410:Casp3 protein, rat; D053148:Caspase 3; D002118:Calcium