Session 2J: The Effect of XBP-1 Splice on Transcription of SHP in the Liver
Session Number
Session 2J: 1st Presentation
Advisor(s)
Dr. Richard Green, Northwestern University
Location
Room A123
Start Date
26-4-2018 10:35 AM
End Date
26-4-2018 11:20 AM
Abstract
Bile acid are synthesized by the liver and act as detergent for lipid absorption. X-box binding protein-1 spliced (XBP1s) is a protective molecule expressed when the liver is under ER stress due to cholestasis or proliferation, which can cause excess unfolded or misfolded proteins. The ER stress activates the unfolded protein response (UPR). The short-heterodimer partner (SHP) plays an active role in various hepatic metabolic pathways, and is a factor in lipid metabolism, prompting the exploration of a connection to the UPR. We hypothesize that transfection of XBP1 into HepG2 cells will increase transcription of the -2Kb SHP promotrer, measurable via a luciferase- β-galactosidase reporter assay. Replacing the SHP coding region with a bioluminescent luciferase gene attached 3’prime to the SHP promoter can measure SHP transcription via luminescence. Preliminary testing shows that transfection of XBP1 has a positive effect on SHP transcription. Therefore, we propose to perform five-prime deletional analysis of the SHP-promoter reporter construct by transfecting the construct into HepG2 cells. This will allow us to isolate cis-acting DNA target sequences of the SHP promoter that respond to Xbp1s. Understanding these target sequences will allow us to analyze transcription factors affecting SHP, explaining the connection between UPR and lipid metabolism.
Session 2J: The Effect of XBP-1 Splice on Transcription of SHP in the Liver
Room A123
Bile acid are synthesized by the liver and act as detergent for lipid absorption. X-box binding protein-1 spliced (XBP1s) is a protective molecule expressed when the liver is under ER stress due to cholestasis or proliferation, which can cause excess unfolded or misfolded proteins. The ER stress activates the unfolded protein response (UPR). The short-heterodimer partner (SHP) plays an active role in various hepatic metabolic pathways, and is a factor in lipid metabolism, prompting the exploration of a connection to the UPR. We hypothesize that transfection of XBP1 into HepG2 cells will increase transcription of the -2Kb SHP promotrer, measurable via a luciferase- β-galactosidase reporter assay. Replacing the SHP coding region with a bioluminescent luciferase gene attached 3’prime to the SHP promoter can measure SHP transcription via luminescence. Preliminary testing shows that transfection of XBP1 has a positive effect on SHP transcription. Therefore, we propose to perform five-prime deletional analysis of the SHP-promoter reporter construct by transfecting the construct into HepG2 cells. This will allow us to isolate cis-acting DNA target sequences of the SHP promoter that respond to Xbp1s. Understanding these target sequences will allow us to analyze transcription factors affecting SHP, explaining the connection between UPR and lipid metabolism.