Hepatic Steatosis is a critical stage in the pathology of alcoholic liver disease. It has been suggested that not only does the severity of steatosis predict the severity of later stages of ALD but that preventing steatosis caused by ethanol could also prevent the later stages of ALD (i.e., fibrosis and cirrhosis). In a previous study done by our laboratory, it was shown that metformin, an insulin sensitizing drug, blocks steatosis caused by ethanol, suggesting that insulin resistance could play a causal role in ethanol-induced steatosis. Protein kinase c-epsilon (PKCe) has been shown to cause hepatic insulin resistance as well non-alcoholic fatty liver disease, therefore we hypothesize that PKCe has a causal role in ALD by causing hepatic insulin resistance. This hypothesis will be tested via the following Specific Aims. 1). To test the hypothesis that PKCe has a causal role in ethanol-induced steatosis. In the Preliminary Studies, it was shown that acute ethanol exposure leads to an increase in PKCe activity before the onset of ethanol-induced steatosis. Next, we determined that PKCe-/- mice are partially protected against steatosis due to ethanol. The goal of this aim is to build on these Preliminary Studies. 2). To determine the mechanism by which ethanol is increasing diacylglycerol (DAG) synthesis. One of the prominent activators of PKCe is DAG. De novo DAG formation can be increased by alcohol via an increase in flux of long chain fatty-acyl CoAs and/or glyceraldehyde-3-phosphate into the triacylglycerol pathway. However, the relative contributions of these potential pathways are unclear. Therefore, the goal of this aim is to determine the relative contribution of these 2 potential pathways of DAG formation under these conditions. 3). To test the hypothesis that PKCe and Gdc1 inhibition will prevent liver damage owing to chronic exposure. We expect the results of Specific Aims 1 and 2 to determine that PKCe plays a causal role in ethanol-induced steatosis. However, the role of this enzyme in chronic ethanol exposure is not yet known. Therefore, the goal of this aim is to determine the effect of genetic inhibition of PKCe and Gdc1 on liver damage caused by chronic ethanol exposure. ALD is one of the leading causes of death in the world, affecting millions of people per year. From the years 1985 to 1992, it is estimated that over $148 billion was spent to treat people with this disease. However, due to poor understanding of the biochemical mechanisms responsible for ALD, there is no FDA approved therapy to treat the disease. Therefore, the goal of this work is to provide better understanding of the mechanisms responsible for ALD, in hopes of identifying a therapeutic target to not only prevent but also reverse the progression of the disease.
|Kaiser, J Phillip; Guo, Luping; Beier, Juliane I et al. (2014) PKCÎµ contributes to chronic ethanol-induced steatosis in mice but not inflammation and necrosis. Alcohol Clin Exp Res 38:801-9|
|Beier, Juliane I; Kaiser, J Phillip; Guo, Luping et al. (2011) Plasminogen activator inhibitor-1 deficient mice are protected from angiotensin II-induced fibrosis. Arch Biochem Biophys 510:19-26|
|von Montfort, Claudia; Beier, Juliane I; Kaiser, J Phillip et al. (2010) PAI-1 plays a protective role in CCl4-induced hepatic fibrosis in mice: role of hepatocyte division. Am J Physiol Gastrointest Liver Physiol 298:G657-66|
|Kaiser, J Phillip; Beier, Juliane I; Zhang, Jun et al. (2009) PKCepsilon plays a causal role in acute ethanol-induced steatosis. Arch Biochem Biophys 482:104-11|