|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | |||||
Journal of Cell Science, Vol 113, Issue 17 2941-2953, Copyright © 2000 by Company of Biologists
JOURNAL ARTICLES |
VL Johnson, SC Ko, TH Holmstrom, JE Eriksson and SC Chow
Centre for Mechanisms of Human Toxicity, University of Leicester, Hodgkin Building, Lancaster Road, Leicester LE1 9HN, UK.
Nuclear morphological changes during apoptosis are very distinct and effector caspases have been implicated to play a central role in these processes. To investigate this in greater detail we examined the effect of blocking caspase activity and its activation on the nuclear morphological change in Jurkat T cells undergoing apoptosis after staurosporine treatment. In the presence of caspase inhibitors, like benzyloxycarbonyl-Val-Ala-Asp fluoro-methylketone (z-VAD-FMK), N-acetyl Tyr-Val-Ala-Asp chloromethylketone (Ac-YVAD-CMK) and benzyloxy-carbonyl-Asp-Glu-Val-Asp (OMe) fluoromethylketone (z-DEVD-FMK), staurosporine-treated Jurkat cells displayed a nuclear morphological change distinct from that of normal and apoptotic cells. This nuclear morphological change is an early event, characterised by convoluted nuclei with cavitations, and clumps of chromatin abutting to inner regions of the nuclear envelope between the nuclear pores. Both the nuclear envelope and endoplasmic reticulum were grossly dilated. This pre-apoptotic nuclear change precedes the externalisation of phosphatidylserine, chromatin condensation and DNA laddering, and can be dissociated from the formation of high molecular weight DNA fragments and cell shrinkage. Although cytochrome c efflux from the mitochondria and the processing of caspase-3 were observed in Jurkat cells with pre-apoptotic nuclear morphology, caspase-2, -6, -7 and -8 were not activated. In the presence of z-DEVD-FMK or Ac-YVAD-CMK, caspase-3 was processed to both the p17 and p20 fragments in staurosporine-treated cells, but only to p20 fragment in the presence of z-VAD-FMK. However, the caspase-3 substrate, poly(ADP ribose) polymerase was not cleaved in the presence of z-VAD-FMK, despite >70% of the cells have pre-apoptotic nuclei. In addition, caspase-3 null MCF-7 cells also undergo pre-apoptotic nuclear change when treated with staurosporine in the presence of caspase inhibitors, indicating that caspase-3 is not required for the early nuclear morphological change in cells undergoing apoptosis. Although cell death in staurosporine-treated Jurkat cells was markedly delayed, they eventually die without discernible downstream apoptotic features. Other apoptotic stimuli like etoposide and the heavy metal chelator, N,N,N',N'-tetrakis (2-pyridylmethyl) ethylenediamine also induced this nuclear morphological change in Jurkat cells in the presence of z-VAD-FMK. In summary, the effector caspases are not involved in early nuclear morphological change, which precedes the conventional hallmark morphological changes associated with chemical-induced apoptosis.
This article has been cited by other articles:
![]() |
J.-H. Yang, M.-Y. Wu, C.-D. Chen, M.-J. Chen, Y.-S. Yang, and H.-N. Ho Altered apoptosis and proliferation in endometrial stromal cells of women with adenomyosis Hum. Reprod., April 1, 2007; 22(4): 945 - 952. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. P. Lawrence, A. Kadioglu, A.-L. Yang, W. R. Coward, and S. C. Chow The Cathepsin B Inhibitor, z-FA-FMK, Inhibits Human T Cell Proliferation In Vitro and Modulates Host Response to Pneumococcal Infection In Vivo J. Immunol., September 15, 2006; 177(6): 3827 - 3836. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. Taimen and M. Kallajoki NuMA and nuclear lamins behave differently in Fas-mediated apoptosis J. Cell Sci., February 1, 2003; 116(3): 571 - 583. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Cha, E. K. Lee, and P. Shapiro Identification of a C-terminal Region That Regulates Mitogen-activated Protein Kinase Kinase-1 Cytoplasmic Localization and ERK Activation J. Biol. Chem., December 14, 2001; 276(51): 48494 - 48501. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. H. Wyllie and P. Golstein More than one way to go PNAS, January 2, 2001; 98(1): 11 - 13. [Full Text] [PDF] |
||||