Extracellular catalase activity protects cysteine cathepsins from inactivation by hydrogen peroxide.
The resistance of secreted cysteine cathepsins to peroxide inactivation was evaluated using as model THP-1 cells. Differentiated cells released mostly cathepsin B, but also cathepsins H, K, and L, with a maximum of endopeptidase activity at day 6. Addition of non-cytotoxic concentrations of H(2)O(2) did not affect mRNA expression levels and activity of cathepsins, while the catalase activity remained also unchanged, consistently with RT-PCR analysis. Conversely inhibition of extracellular catalase led to a striking inactivation of secreted cysteine cathepsins by H(2)O(2). This report suggests that catalase may participate in the protection of extracellular cysteine proteases against peroxidation.
Hervé-Grépinet
Virginie
V
INSERM U 618, Protéases et Vectorisation Pulmonaires, Equipe Protéases et Pathologies Pulmonaires, Tours F-37000, France.
Veillard
Florian
F
Godat
Emmanuel
E
Heuzé-Vourc'h
Nathalie
N
Lecaille
Fabien
F
Lalmanach
Gilles
G
D001483:Base Sequence; D002374:Catalase / Q000378:metabolism*; D002403:Cathepsins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D017931:DNA Primers; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction
D017931:DNA Primers; D012333:RNA, Messenger; D006861:Hydrogen Peroxide; D002374:Catalase; D002403:Cathepsins