CREB Protein Mediates Alcohol‐Induced Circadian Disruption and Intestinal Permeability

Abstract

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 PER2 is increased after exposure to alcohol and siRNA knockdown of PER2 in vitro blocks alcohol-induced intestinal barrier dysfunction. We have shown that blocking CYP2E1 (i.e., important for alcohol metabolism) with siRNA inhibits the alcohol-induced increase in PER2 and suggesting that oxidative stress may mediate alcohol-induced increase in PER 2 in intestinal epithelial cells. The Aim of the current study was to elucidate whether a mechanism incited by alcohol-derived oxidative stress mediates the transcriptional induction of PER2 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 C57BL/6J mice (WT) mice were fed with alcohol diet (29% of total calories, 4.5% v/v) for 8 weeks. Western Blot was used to analyze PER2 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 pre-treatment of Caco-2 cells with an anti-oxidant scavenger. Alcohol-derived oxidative stress activated CREB via the PKA pathway and increased PER2 mRNA and protein. Inhibiting CREB prevented the increase in PER2 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.

Colorectal Cancer and Alcohol Consumption—Populations to Molecules

“…Ethanol, through multiple mechanisms, is also able to increase the permeability of the intestinal barrier (often referred to as “leaky gut”) that allows further LPS penetration and exposure [ 62 , 118 ]. Oxidative stress from the CYP2E1 metabolism of ethanol could increase intestinal permeability [ 119 , 120 ]. We have shown that, in a Caco-2 cell model, increased oxidative stress leads to increased CREB phosphorylation [ 119 ].…”

“…Oxidative stress from the CYP2E1 metabolism of ethanol could increase intestinal permeability [ 119 , 120 ]. We have shown that, in a Caco-2 cell model, increased oxidative stress leads to increased CREB phosphorylation [ 119 ]. This CREB phosphorylation increases hyperpermeability, most likely, through increased ROS production, which can directly affect the barrier’s integrity [ 5 ].…”

“…There are other mechanisms that can contribute to ethanol’s increase in intestinal inflammation in cases of CRC [ 117 , 119 , 120 , 127 , 128 , 129 ]. Our group showed that chronic alcohol consumption accelerates polyposis in mice; the enhanced polyposis and submucosal invasion in our model was associated with an increased mast cell infiltration in the submucosa [ 13 ].…”

Intestinal permeability and bacterial translocation in patients with liver disease, focusing on alcoholic aetiology: methods of assessment and therapeutic intervention

“… 35 A study on Caco-2 cells showed that alcohol exposure increased oxidative stress and caused monolayer dysfunction, as measured by reduced transepithelial resistance as well as an increase in the levels of circadian clock proteins PER2 and CLOCK. 36 These effects were not seen when the monolayers were pre-treated with an antioxidant scavenger.…”

Cancer Stem Cells: «Emergency Service» for Tumors Under Generalized Cellular Stress

“…Однако существуют и достаточно убедительные прямые доказательства индукции стволовости в ответ на оксидативный стресс [77][78][79]. Мы нашли доказательства активирующего действия оксидативного стресса для 34 генов из нашего списка: Abca1 [80], Acpp [81], Aldh1a1 [82], Alox15 [83], Arg2 [84], Blnk [46], Ccr3 [85], Cd200 [86], Cd55 [87], Col3a1 [88], Comp [89], Cp [90], Eef1a2 [91], Fgfr1 [92], Gas6 [93], Gstm3 [94], Igf1 [95], Igf2 [96], Il10 [97], Lyve1 [95], Mmp2 [98], Nfatc2 [99], Pde4d [100], Pdk4 [101], Per2 [102], Pon1 [103], Prg4 [104], Rragd [105], Selp [106], Serpinb1a [107], Serpinb2 [108,109], Slc2a4 [110], Tal1 [111], Wnt5a [112].…”