High susceptibility of cortical neural progenitor cells to trimethyltin toxicity: involvement of both caspases and calpain in cell death.
Neural progenitor cells play an essential role in both the developing embryonic nervous system and in the adult brain, where the capacity for self-renewal would be important for normal brain functions. In the present study, we used embryonic cortical neural progenitor cells to investigate the effects of trimethyltin chloride (TMT) on the survival of neural progenitor cells. In cultures of cortical neural progenitor cells, the formation of round neurospheres was observed in the presence of epidermal growth factor and basic fibroblast growth factor within 9 days in vitro. The neurospheres were then harvested for subsequent replating and culturing for assessment of cell viability in either the presence or absence of TMT at the concentration of 5microM. Lasting exposure to TMT produced not only nuclear condensation in the cells in a time-dependent manner over a period of 6-24h, but also the release of lactate dehydrogenase into the culture medium. Immunoblot and immunocytochemical analyses revealed that TMT had the ability to activate both caspase-3 and calpain, as well as to cause nuclear translocation of deoxyribonuclease II, which is located within cytoplasm in intact cells. Additionally, treatment with a calpain inhibitor [trans-epoxysuccinyl-l-leucylamido-(4-guanidino) butane] and a caspase inhibitor [Z-Val-Ala-Asp(OMe)-CH2F] produced a significant reduction in damaged cells induced by TMT. Taken together, our data indicate that neural progenitor cells are highly susceptible to TMT in undergoing cell death via the activation of 2 parallel pathways, ones involving calpain and the other, caspase-3.
Yoneyama
Masanori
M
Department of Pharmacology, Faculty of Pharmaceutical Sciences, Setsunan University, Hirakata, Osaka 573-0101, Japan.
Seko
Keiichi
K
Kawada
Koichi
K
Sugiyama
Chie
C
Ogita
Kiyokazu
K
D021581:Active Transport, Cell Nucleus / Q000187:drug effects / Q000502:physiology; D000818:Animals; D002154:Calpain / Q000032:analysis / Q000187:drug effects / Q000378:metabolism*; D053148:Caspase 3 / Q000032:analysis / Q000187:drug effects / Q000378:metabolism*; D016923:Cell Death / Q000187:drug effects / Q000502:physiology; D002467:Cell Nucleus / Q000187:drug effects / Q000473:pathology; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000187:drug effects* / Q000196:embryology / Q000503:physiopathology; D004249:DNA Damage / Q000187:drug effects / Q000502:physiology; D004706:Endodeoxyribonucleases / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007150:Immunohistochemistry; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D051379:Mice; D009410:Nerve Degeneration / Q000139:chemically induced* / Q000473:pathology / Q000503:physiopathology; D009473:Neuronal Plasticity / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000187:drug effects* / Q000473:pathology; D013234:Stem Cells / Q000187:drug effects* / Q000473:pathology; D014298:Trimethyltin Compounds / Q000633:toxicity*
D004791:Enzyme Inhibitors; D014298:Trimethyltin Compounds; C046488:trimethyltin; D007770:L-Lactate Dehydrogenase; D004706:Endodeoxyribonucleases; C019329:deoxyribonuclease II; D002154:Calpain; C505409:Casp3 protein, mouse; D053148:Caspase 3