Bcl-2 sustains hormetic response by inducing Nrf-2 nuclear translocation in L929 mouse fibroblasts.
Hormesis is the process whereby exposure to a low dose of a chemical agent induces an adaptive effect on the cell or organism. This response evokes the expression of cytoprotective and antioxidant proteins, allowing pro-oxidants to emerge as important hormetic agents. The antiapoptotic protein Bcl-2 is known to protect cells against death induced by oxidants; it has been suggested that Bcl-2 might also modulate steady-state reactive oxygen species levels. The aim of this work was to find out if Bcl-2 might play a role during the hormetic response and in Nrf-2 activation. We have established a model to study the oxidative conditioning hormesis response (OCH) by conditioning the cell line L929 with 50muM H(2)O(2) for 9h. This condition did not induce oxidative damage nor oxidative imbalance, and OCH cells maintained a 70-80% survival rate after severe H(2)O(2) treatment compared to nonconditioned cells. When cells were pretreated with the Bcl-2 inhibitor HA14-1 or were silenced with Bcl-2-siRNA, both the hormetic effect and the Nrf-2 nuclear translocation previously observed were abrogated. Our results suggest a sequence of causal events related to increase in Bcl-2 expression, induction of Nrf-2 activation, and sustained expression of cytoprotective proteins such as GST and gammaGCS.
Luna-López
Armando
A
Departamento de Ciencias de la Salud, División de Ciencias Biológicas y de la Salud, Universidad Autónoma Metropolitana Iztapalapa, CP 09340 México, DF, México.
Triana-Martínez
Francisco
F
López-Diazguerrero
Norma E
NE
Ventura-Gallegos
José L
JL
Gutiérrez-Ruiz
María C
MC
Damián-Matsumura
Pablo
P
Zentella
Alejandro
A
Gómez-Quiroz
Luis E
LE
Königsberg
Mina
M
D021581:Active Transport, Cell Nucleus / Q000187:drug effects / Q000235:genetics; D000818:Animals; D001578:Benzopyrans / Q000494:pharmacology; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism*; D019610:Cytoprotection / Q000187:drug effects / Q000235:genetics; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D006861:Hydrogen Peroxide / Q000494:pharmacology; D051379:Mice; D051267:NF-E2-Related Factor 2 / Q000235:genetics / Q000378:metabolism*; D009570:Nitriles / Q000494:pharmacology; D018384:Oxidative Stress; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000235:genetics; D015533:Transcriptional Activation / Q000187:drug effects / Q000235:genetics
D001578:Benzopyrans; D051267:NF-E2-Related Factor 2; D009570:Nitriles; D019253:Proto-Oncogene Proteins c-bcl-2; D034741:RNA, Small Interfering; C456800:ethyl 2-amino-6-bromo-4-(1-cyano-2-ethoxy-2-oxoethyl)-4H-chromene-3-carboxylate; D006861:Hydrogen Peroxide