8A). We also determined that HIF1dPA overexpression resulted in increased HIF-1α mRNA (Fig. 8B), and this was associated with increased triglyceride levels compared with control cells (Fig. 8C). Furthermore, we found that either MCP-1 treatment or HIF1dPA plasmid treatment resulted in increased lipid accumulation in Huh7 cells (Fig. 8E). To establish a further mechanistic insight into the role of HIF1 in hepatocyte lipid accumulation,

we sought to determine whether we could block lipid accumulation in MCP-1 treated cells by silencing HIF-1α. When Huh7 cells were treated with HIF-1α siRNA, we found that expression of HIF-1α mRNA was significantly Decitabine nmr suppressed at 24 and 36 hours (Supporting Fig. 3). Next, Huh7 cells that had been pretreated with HIF-1α siRNA were challenged with MCP-1 stimulation. We found increased

triglyceride in scrambled siRNA control but not in HIF-1α–siRNA pretreated cells after the MCP-1 challenge (Fig. 8E). Using Oil Red O staining we also confirmed that HIF-1α siRNA pretreatment could prevent MCP-1 treatment–induced lipid accumulation (Fig. 8F). These results suggest a link between alcohol-induced increases in HIF-1, MCP-1, and lipid accumulation in hepatocytes. In this study, we provide evidence for an effect of HIF-1α INK-128 on hepatic lipid accumulation in ALD. Although the relationship between alcohol and hypoxia in the liver has been described, our novel observations ascribe a specific pathophysiological role to the dysregulation of a hypoxia-responsive transcription factor in ALD. We 上海皓元医药股份有限公司 found that chronic alcohol feeding results in increased HIF-1α levels and activation in the liver. We further demonstrated that constitutive activation of HIF-1α in hepatocytes accelerates lipid accumulation with chronic ethanol feeding, and report that HIF1dPA mice have higher steatosis on histology evaluation and increased hepatic triglyceride levels compared with control mice. We report for the first time that alcohol-induced lipid accumulation can be prevented in mice with

hepatocyte-specific deletion of HIF-1α. Using an in vitro system, we found that inhibition of HIF-1α prevents lipid accumulation. We also demonstrated that the protective effect of HIF-1α deletion may be independent of PPARα, and may depend upon regulation of other genes involved in lipid homeostasis, including the adipocyte differentiation related protein. Our data further suggested that the up-regulation of MCP-1 observed in LPS-injected, ethanol-fed mice may be an upstream mediator of HIF-1α expression, as MCP-1 treatment resulted in increased HIF-1α expression in vitro. Finally we present data to show that inhibition of HIF-1α prevents lipid accumulation in vitro in response to MCP-1 treatment. Our novel observations link alcohol-induced induction of HIF-1α and alcohol-induced steatosis in a mechanistic way.