Ana Maria Cuervo and J. Fred Dice

Department of Physiology Tufts University School of Medicine, Boston, USA

Received 12/5/97 Accepted 12/9/97

TABLE OF CONTENTS

1. Abstract

2. Introduction: what happens to senescent cells?

3. Model systems for the study of aging

4. Intracellular proteolytic systems and aging

4.1. Cytosolic proteolytic systems: Proteasomes and calpains

4.1.1. Ubiquitin-proteasome system
4.1.2. Calpains
4.2. Lysosomal proteolytic pathways
4.2.1. Fusion of lysosomes with vesicular compartments
4.2.2. Macroautophagy and microautophagy
4.2.3. Direct transport of cytosolic proteins through the lysosomal membrane

5. Tissue-specific changes in proteolytic systems with aging

5.1. Central nervous system
5.2. Liver and cultured fibroblasts
5.3. Skeletal muscle
5.4. Eye lens

6. Conclusions and perspectives

7. Acknowledgments

8. References

9. Entire manuscript