1. Swelling rather than shrinkage precedes apoptosis in serum-deprived vascular smooth muscle cells.
- Author
-
Platonova A, Koltsova SV, Hamet P, Grygorczyk R, and Orlov SN
- Subjects
- Animals, Caspase 3 metabolism, Cells, Cultured, Chromatin metabolism, Colforsin pharmacology, Culture Media, Serum-Free, DNA Cleavage, Myocytes, Smooth Muscle drug effects, Osmotic Pressure, Ouabain pharmacology, Rats, Single-Cell Analysis, Staurosporine pharmacology, Time-Lapse Imaging, Apoptosis drug effects, Cell Size, Muscle, Smooth, Vascular cytology, Myocytes, Smooth Muscle physiology
- Abstract
Contrasting cell volume behaviours (swelling vs. shrinkage) are considered as criteria to distinguish necrosis from apoptosis. In this study, we employed a time-lapse, dual-image surface reconstruction technique to assess the volume of single vascular smooth muscle cells transfected with E1A-adenoviral protein (E1A-VSMC) and undergoing rapid apoptosis in the absence of growth factors or in the presence of staurosporine. After 30- to 60-min lag-phase, serum-deprived E1A-VSMC volume was increased by ~40%, which preceded maximal increments of caspase-3 activity and chromatin cleavage. Swollen cells underwent rapid apoptotic collapse, documented by plasma membrane budding, and terminated in 10-15 min by the formation of numerous apoptotic bodies. Suppression of apoptosis by inhibition of Na(+),K(+)-ATPase and activation of cAMP signalling with ouabain and forskolin, respectively, completely abolished the swelling of serum-deprived E1A-VSMC. In contrast to serum deprivation, apoptotic collapse of staurosporine-treated E1A-VSMC preceded attenuation of their volume by ~30%. Neither transient hyposmotic swelling nor isosmtotic shrinkage triggered apoptosis. Our results show that cell shrinkage can not be considered as ubiquitous hallmark of apoptosis. The involvement of stimulus-specific cell volume perturbations in initiation and progression of apoptosis in vascular smooth muscle cells should be examined further.
- Published
- 2012
- Full Text
- View/download PDF