“What’s Eating You?” Quantifying Proteolytic Activity in Health and Disease with Novel Assays and Computational Models

Abstract

Cathepsins are enzymes with the most powerful human collagenase and elastase activity that are upregulated at sites of normal tissue remodeling and during tissue-destructive disease progression. We study them in the context of tissue remodeling in cancer progression and cardiovascular diseases such as sickle cell disease and atherosclerosis. They are synthesized as stable inactive precursors requiring activation by propeptide cleavage, and detection of mature cathepsins and quantification of specific activity have proven difficult due to instability of the mature, active enzyme extracellularly, diminishing appreciation for their involvement in a large number of diseases. During this seminar, we will discuss our studies of this family of powerful proteases in diseases with particular attention to cancer and sickle cell disease. First, we will discuss the important development of a reliable, sensitive method of zymography to detect the activity of mature cathepsins K, L, S, and V and integrating that assay with the development of a computational kinetic model to predict cathepsin-mediated tissue remodeling by cells during advancing disease. Secondly, we will discuss our applications of these technologies and potential use as both diagnostic and prognostic indicators of human breast, lung, and cervical cancer as well as newly identified mechanisms of cathepsin activity in complications of stroke in children with sickle cell disease.