Nrf2-dependent protection from LPS induced inflammatory response and mortality by CDDO-Imidazolide

RK Thimmulappa, C Scollick, K Traore, M Yates… - Biochemical and …, 2006 - Elsevier
RK Thimmulappa, C Scollick, K Traore, M Yates, MA Trush, KT Liby, MB Sporn…
Biochemical and biophysical research communications, 2006Elsevier
Sepsis induced lethality is characterized by amplified host innate immune response. Nrf2, a
bZIP transcription factor, regulates a battery of cellular antioxidative genes and maintains
cellular redox homeostasis. This study demonstrates that increasing Nrf2 activity by a potent
small molecule activator, CDDO-Im (1-[2-cyano-3-, 12-dioxooleana-1, 9 (11)-dien-28-oyl]
imidazole), protects from deregulation of lipopolysaccharide (LPS) induced innate immune
response. In response to LPS stimuli, nrf2-deficient (nrf2−/−) peritoneal neutrophils showed …
Sepsis induced lethality is characterized by amplified host innate immune response. Nrf2, a bZIP transcription factor, regulates a battery of cellular antioxidative genes and maintains cellular redox homeostasis. This study demonstrates that increasing Nrf2 activity by a potent small molecule activator, CDDO-Im (1-[2-cyano-3-,12-dioxooleana-1,9(11)-dien-28-oyl]imidazole), protects from deregulation of lipopolysaccharide (LPS) induced innate immune response. In response to LPS stimuli, nrf2-deficient (nrf2 −/−) peritoneal neutrophils showed increased NADPH oxidase-dependent ROS generation, proinflammatory cytokines (Tnf-α and Il-6) and chemokines (Mip2 and Mcp-1) relative to wild-type (nrf2 +/+) cells. Pretreatment of peritoneal neutrophils with CDDO-Im induced antioxidative genes (Ho-1, Gclc, Gclm, and Nqo1) and attenuated LPS induced ROS generation as well as expression of proinflammatory cytokines exclusively in nrf2 +/+ neutrophils but not in nrf2 −/− cells. In corroboration with in vitro studies, pretreatment with CDDO-Im induced Nrf2-dependent antioxidative genes, attenuated LPS induced proinflammatory cytokine expression, and decreased mortality specifically in the nrf2 +/+ mice. In conclusion, the results suggest that Nrf2 is associated with oxidative regulation of LPS induced innate immune response in neutrophils. Activation of Nrf2-dependent compensatory antioxidative pathways by CDDO-Im protects from LPS induced inflammatory response and mortality.
Elsevier