Analysis of nuclear apoptotic process in a cell-free system

We report an analysis of the apoptotic process of mouse liver nuclei induce d in a cell-free carrot cytosol system by cytochrome c. Typical characteris tics of apoptosis were observed. such as chromatin condensation. marginatio n, apoptotic bodies and DNA ladders. Furthermore, transmission and scanning electron microscope analysis of the apoptotic nuclei detected chromatin-fr ee nuclear vesicles before apoptotic bodies appeared at a comparatively lat e phase. When AC-YVAD-CHO, an inhibitor of caspase 6, was introduced into t he system, these vesicles and apoptotic bodies disappeared completely withi n our study sections. We confirmed the results using whole-mount electron m icroscopy, and found that although the nuclear lamina was destroyed early, the nuclear matrix largely remained intact during the course of apoptosis. The nuclear matrix played an important role in maintaining the integrity of apoptotic cells and connecting the apoptotic bodies and apoptotic nucleus.