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CREB Protein Mediates Alcohol‐Induced Circadian Disruption and Intestinal Permeability
Author(s) -
Davis Booker T,
Voigt Robin M.,
Shaikh Maliha,
Forsyth Christopher B.,
Keshavarzian Ali
Publication year - 2017
Publication title -
alcoholism: clinical and experimental research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.267
H-Index - 153
eISSN - 1530-0277
pISSN - 0145-6008
DOI - 10.1111/acer.13513
Subject(s) - oxidative stress , endocrinology , medicine , circadian rhythm , alcohol , western blot , intestinal permeability , gene knockdown , per2 , chemistry , circadian clock , biology , biochemistry , clock , apoptosis , gene
Background Alcoholic liver disease ( ALD ) is commonly associated with intestinal permeability. An unanswered question is why only a subset of heavy alcohol drinkers develop endotoxemia. Recent studies suggest that circadian disruption is the susceptibility factor for alcohol‐induced gut leakiness to endotoxins. The circadian protein PER 2 is increased after exposure to alcohol and si RNA knockdown of PER 2 in vitro blocks alcohol‐induced intestinal barrier dysfunction. We have shown that blocking CYP 2E1 (i.e., important for alcohol metabolism) with si RNA inhibits the alcohol‐induced increase in PER 2 and suggesting that oxidative stress may mediate alcohol‐induced increase in PER 2 in intestinal epithelial cells. The aim of this study was to elucidate whether a mechanism incited by alcohol‐derived oxidative stress mediates the transcriptional induction of PER 2 and subsequent intestinal hyperpermeability. Methods Caco‐2 cells were exposed to 0.2% alcohol with or without pretreatment with modulators of oxidative stress or PKA activity. Permeability of the Caco‐2 monolayer was assessed by transepithelial electrical resistance. Protein expression was measured by Western blot and mRNA with real‐time polymerase chain reaction. Wild‐type C57 BL /6J mice were fed with alcohol diet (29% of total calories, 4.5% v/v) for 8 weeks. Western blot was used to analyze PER 2 expression in mouse proximal colon tissue. Results Alcohol increased oxidative stress, caused Caco‐2 cell monolayer dysfunction, and increased levels of the circadian clock proteins PER2 and CLOCK. These effects were mitigated by pretreatment of Caco‐2 cells with an antioxidant scavenger. Alcohol‐derived oxidative stress activated cAMP response element‐binding (CREB) via the PKA pathway and increased PER 2 mRNA and protein. Inhibiting CREB prevented the increase in PER 2 and Caco‐2 cell monolayer hyperpermeability. Conclusions Taken together, these data suggest that strategies to reduce alcohol‐induced oxidative stress may alleviate alcohol‐mediated circadian disruption and intestinal leakiness, critical drivers of ALD .