Alcohol-induced in vivo intestinal effects

were mimicked by ACR in LDE225 in vivo intestinal Caco2 cells; specifically, ACR down-regulated tight junction proteins, resulting in disruption of TEER (transepithelial electrical resistance) and FD-4 permeability. These intestinal effects correlated with hepatic steatosis, activation of JNK, ER stress, and hepatocyte apoptosis. Hepatic cells exposed in vitro to ACR and alcohol exposure exhibited similar effects, with ER stress, mitochon-drial disruption and cell death by Cellomics analysis. Notably, the cytotoxic effects of ACR and alcohol were attenuated by acrolein scavengers. Conclusions: Our study demonstrates that acrolein is an important mediator of the hepatic and intestinal effects of alcohol consumption, and may play a critical pathogenic role in ALD. Further, our

data suggest a therapeutic potential for acrolein scavengers in ALD. Disclosures: Shirish Barve – Speaking and Teaching: Abbott Craig J. McClain – Consulting: Vertex, Gilead, Baxter, Celgene, Nestle, Danisco, Abbott, Genentech; Grant/Research PLX4032 in vitro Support: Ocera, Merck, Glaxo SmithKline; Speaking and Teaching: Roche The following people have nothing to disclose: Wei-Yang Chen, Jingwen Zhang, Swati Joshi-Barve Background: Cellular senescence is a programmed reaction to stress that limits the proliferation of damaged cells and leads to a stable arrest of the cell-cycle. Accumulation of senescent hepatocytes may contribute to loss of functional hepatic mass and lead to liver decompensation and fibrosis. The current study aims to characterize the functional role of cellular senescence

during alcohol-induced hepatitis. Methods: Senescence related gene expression was assessed using a Cellular Senescence PCR Array and/or real-time PCR analysis in ethanol- and LPS-treated normal human hepatocytes (N-Hep) and cholan-giocytes (HiBEC), as well as in liver specimens from alcohol or control fed mice. Cellular senescence and viability MCE were measured by SA-p-gal Activity and MTS assay. The upstream modulators of senescence were defined in ethanol/LPS treated hepatocytes and cholangiocytes in vitro, and in TLR-4 knockout mice in vivo. Results: We identified that 5 weeks of ethanol feeding significantly increased the total liver histopathology score and hepatocellular senescence by PCR array and SA-p-gal assay. The up-regulation of hepatic senescence initiators, PAI-1 and EGR1, were further verified by real-time PCR assay. Treatment of N-Heps and HiBECs with ethanol (86 mM) and LPS (20 ng/ml) for 72 hr significantly increased PAI-1 and EGR1 expression, along with the enhanced SA-p-gal activity and reduced cellular viability detected by MTS assay. Silencing of PAI-1 decreased ethanol and LPS-induced senescence in both N-Heps and HiBECs, whereas inhibition of EGR1 only reduced the senescence and increased viability in N-Hep cells.