INCREASED PROTEOLYTIC ACTIVITY IN LYMPHOCYTES FROM PATIENTS WITH EARLY-ONSET ALZHEIMERS-DISEASE

The levels of calpains (m-calpain and mu-calpain) in peripheral blood lymphocytes from patients with Alzheimer's disease were determined via Western blotting. The Ca-dependent proteolytic activity and the calpa statin activity were estimated using incubation with exogenous substra te. Evidence was obtained for an increased Ca-depenGent proteolytic ac tivity in lymphocytes from patients with early onset Alzheimer's disea se. There was also an increased level of membrane-bound mu-calpain in this group of patients. The observed changes may be caused by a genera l dysregulation of Ca homeostasis in peripheral cells of early onset A lzheimer