title: Caspases-2, -3, and -7 are involved in thapsigargin-induced apoptosis of SH-SY5Y neuroblastoma cells.
abstract: Caspase-2 has been reported to play a role in the cell death observed under a number of different conditions; however, it is unclear whether caspase-2 plays a role in cell death triggered by endoplasmic reticulum (ER) stress. The purpose of this study was to determine whether caspase-2 is involved in SH-SY5Y neuroblastoma cell death caused by thapsigargin-induced ER stress. Thapsigargin treatment (1 microM, 16 hr) stimulated the proteolytic processing of caspases-2, -3, and -7, suggesting that these caspases are activated by ER stress. The role of these caspases in thapsigargin-induced cell death was examined by using cell-permeable caspase inhibitors. In the absence of pretreatment with caspase inhibitors, thapsigargin (0.1 microM, 20 hr) reduced the number of viable cells to 53.9% +/- 3.3% of starting-time control. Pretreatment for 90 min with either the pan-caspase inhibitor Z-VAD-FMK or the caspase-2-selective inhibitor Z-VDVAD-FMK inhibited thapsigargin-stimulated cell death, resulting in the number of viable cells being 115.6% +/- 5.3% (P < 0.001) and 69.3% +/- 2.9% (P < 0.01), respectively, of starting-time control. Neither the caspase-3- and -7-selective inhibitor Z-DEVD-FMK nor the caspase-9-selective inhibitor Z-LEHD-FMK significantly affected thapsigargin-stimulated cell death. An anticaspase-12-reactive protein was also identified in SH-SY5Y cells, but thapsigargin had no effect on proteolysis of this protein. These data demonstrate that caspases-2, -3, and -7 are involved in ER stress-mediated death of SH-SY5Y cells.
authors.affiliation: Department of Molecular Sciences and the Neuroscience Institute, College of Medicine, University of Tennessee Health Science Center, University of Tennessee, Memphis, Tennessee 38163, USA. mdahmer@utmem.edu
authors.forename: Mary K
authors.initials: MK
authors.lastname: Dahmer
mesh_terms: D000704:Analysis of Variance; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western / Q000379:methods; D053143:Caspase 2; D053148:Caspase 3; D053179:Caspase 7; D061945:Caspase Inhibitors; D020169:Caspases / Q000378:metabolism*; D045744:Cell Line, Tumor; D004347:Drug Interactions; D004791:Enzyme Inhibitors / Q000633:toxicity*; D006801:Humans; D009447:Neuroblastoma; D019284:Thapsigargin / Q000633:toxicity*
chemical_list: D061945:Caspase Inhibitors; D004791:Enzyme Inhibitors; D019284:Thapsigargin; C505407:CASP3 protein, human; C505520:CASP7 protein, human; D053143:Caspase 2; D053148:Caspase 3; D053179:Caspase 7; D020169:Caspases