Different gene expression associated with non-alcoholic fatty liver disease progression
Non-alcoholic fatty liver disease (NAFLD) is the accumulation of fat in the liver in people who have no alcohol consumption. It is important to study because if it goes undiagnosed, NAFLD may progress into more serious liver damage (i.e. liver cirrhosis or hepatocellular carcinoma). Previous research determined that AQP1, MGMT, FGFR2, and RBP5 are 4 commonly hypomethylated genes in NAFLD patients and that fructose affects the way lipids metabolize and change the gene expression of liver tissue. This project took HepG2 cells, a hepatocyte cell line, and analyzed the different levels of gene expression in palmitate vs. combined palmitate and fructose treatment using q-PCR analysis. Results showed that gene expression decreased for AQP1, FGFR2, and RBP5 after palmitate treatment but MGMT showed no significant difference. The combined treatment group showed increased expression for some genes and decreased expression for others. Most importantly, it had a noticeable difference in expression compared to the palmitate treatment group. The overall conclusions are as follows: lipid treated hepatocytes show decreased gene expression for AQP1, FGFR2, and RBP5 compared to untreated hepatocytes, MGMT expression is not regulated by palmitate in HepG2 cells, and fructose modulates the effects of palmitate treatment in HepG2 cells. The results from this experiment do not correlate with the methylation data previously mentioned. We propose that this discrepancy might be due to the fact that the methylation data was due to cells other than hepatocytes. In order to further understand these genes and their role in NAFLD progression, it would be useful to repeat this experiment with primary cells or other liver cells such as hepatic stellate cells (HSCs).