The ATM kinase inhibitor KU-55933 provides neuroprotection against hydrogen peroxide-induced cell damage via a γH2AX/p-p53/caspase-3-independent mechanism: Inhibition of calpain and cathepsin D.
The role of the kinase ataxia-telangiectasia mutated (ATM), a well-known protein engaged in DNA damage repair, in the regulation of neuronal responses to oxidative stress remains unexplored. Thus, the neuroprotective efficacy of KU-55933, a potent inhibitor of ATM, against cell damage evoked by oxidative stress (hydrogen peroxide, H2O2) has been studied in human neuroblastoma SH-SY5Y cells and compared with the efficacy of this agent in models of doxorubicin (Dox)- and staurosporine (St)-evoked cell death. KU-55933 inhibited the cell death induced by H2O2or Dox but not by St in undifferentiated (UN-) and retinoic acid-differentiated (RA)-SH-SY5Y cells, with a more pronounced effect in the latter cell phenotype. Furthermore, this ATM inhibitor attenuated the Dox- but not H2O2-induced caspase-3 activity in both UN- and RA-SH-SY5Y cells. Although KU-55933 inhibited the H2O2- and Dox-induced activation of ATM, it attenuated the toxin-induced phosphorylation of the proteins H2AX and p53 only in the latter model of cell damage. Moreover, the ATM inhibitor prevented the H2O2-evoked increases in calpain and cathepsin D activity and attenuated cell damage to a similar degree as inhibitors of calpain (MDL28170) and cathepsin D (pepstatin A). Finally, we confirmed the neuroprotective potential of KU-55933 against the H2O2- and Dox-evoked cell damage in primary mouse cerebellar granule cells and in the mouse hippocampal HT-22 cell line. Altogether, our results extend the neuroprotective portfolio of KU-55933 to a model of oxidative stress, with this effect not involving inhibition of the γH2AX/p-p53/caspase-3 pathway and instead associated with the attenuation of calpain and cathepsin D activity.
Institute of Pharmacology, Polish Academy of Sciences, Department of Experimental Neuroendocrinology, Smętna Street 12, 31-343 Kraków, Poland.
Jakub
J
Chwastek
Institute of Pharmacology, Polish Academy of Sciences, Department of Experimental Neuroendocrinology, Smętna Street 12, 31-343 Kraków, Poland. Electronic address: jantas@if-pan.krakow.pl.
Danuta
D
Jantas
Institute of Pharmacology, Polish Academy of Sciences, Department of Experimental Neuroendocrinology, Smętna Street 12, 31-343 Kraków, Poland.
Władysław
W
Lasoń
D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D064007:Ataxia Telangiectasia Mutated Proteins / Q000037:antagonists & inhibitors*; D002154:Calpain / Q000037:antagonists & inhibitors*; D053148:Caspase 3 / Q000378:metabolism; D002402:Cathepsin D / Q000037:antagonists & inhibitors*; D016923:Cell Death / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D045744:Cell Line, Tumor; D004305:Dose-Response Relationship, Drug; D004317:Doxorubicin / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D006657:Histones / Q000378:metabolism; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D051379:Mice; D009025:Morpholines / Q000494:pharmacology*; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D018696:Neuroprotective Agents / Q000494:pharmacology*; D010750:Phosphoproteins / Q000378:metabolism; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D011753:Pyrones / Q000494:pharmacology*; D051381:Rats; D019311:Staurosporine / Q000494:pharmacology; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
C495818:2-morpholin-4-yl-6-thianthren-1-yl-pyran-4-one; C468783:H2AX protein, human; D006657:Histones; D009025:Morpholines; D018696:Neuroprotective Agents; D010750:Phosphoproteins; D047428:Protein Kinase Inhibitors; D011753:Pyrones; D016159:Tumor Suppressor Protein p53; D004317:Doxorubicin; D006861:Hydrogen Peroxide; D064007:Ataxia Telangiectasia Mutated Proteins; D002154:Calpain; D053148:Caspase 3; D002402:Cathepsin D; D019311:Staurosporine
Cerebellar granule cells; Doxorubicin; MDL28170; Pepstatin A; SH-SY5Y cells; Staurosporine