Sensitization of stefin B-deficient thymocytes towards staurosporin-induced apoptosis is independent of cysteine cathepsins

Academic Article

Abstract

  • Stefin B (cystatin B) is an inhibitor of lysosomal cysteine cathepsins and does not inhibit cathepsin D, E (aspartic) or cathepsin G (serine) proteinases. In this study, we have investigated apoptosis triggered by camptothecin, staurosporin (STS), and anti-CD95 monoclonal antibody in the thymocytes from the stefin B-deficient mice and wild-type mice. We have observed increased sensibility to STS-induced apoptosis in the thymocytes of stefin B-deficient mice. Pretreatment of cells with pan-caspase inhibitor z-Val-Ala-Asp(OMe)- fluoromethylketone completely inhibited phosphatidylserine externalization and caspase activation, while treatment with inhibitor of calpains- and papain-like cathepsins (2S,3S)-trans-epoxysuccinyl-leucylamido-3-methyl-butane ethyl ester did not prevent caspase activation nor phosphatidylserine exposure. We conclude that sensitization to apoptosis induced by STS in thymocytes of stefin B-deficient and wild-type mice is not dependent on cathepsin inhibition by stefin B. © 2005 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.
  • Published In

  • FEBS Letters  Journal
  • Digital Object Identifier (doi)

    Pubmed Id

  • 18320011
  • Author List

  • Kopitar-Jerala N; Schweiger A; Myers RM; Turk V; Turk B
  • Start Page

  • 2149
  • End Page

  • 2155
  • Volume

  • 579
  • Issue

  • 10