The body's immediate reaction to serious trauma, denoted the Acute Phase Response (APR), coordinates a wide variety of inflammatory signals, and produces a common response, in the massive induction of protective proteins by the liver. While the APR is designed for survival, severe or prolonged activation with its interruption of normal homeostatic functions, likely contributes to organ failure and death in some critically ill patients. Evidence suggests that the APR's repression of steady-state liver function is a byproduct of its mode of induction. Further evidence suggests that this is a highly regulated process, which shares pathways important to early cell type development, and with some signals associated with the proliferative response. Evidence is presented that injury induced regulation of differentiated genes may be mediated through phosphorylation of liver-specific transcription factors, particularly HNF-4. Better understanding of the mechanisms regulating this process would have therapeutic importance in advantageous support of the acute phase response.
The first aim will dissect where on HNF-4 phosphorylation occurs. This will be done by phosphopeptide mapping. We will also identify the kinases and thus the signal transduction pathways that are involved in initiating the APR. This will generate original materials, in the form of altered HNF-4 molecules, to test the importance of this phosphorylation to the APR.
The second aim i s to trace the effect of this phosphorylation on the biochemical activities of HNF-4, its DNA binding and site selection, and changes in its interactions and activities in the cell. This will be carried out using diagnostic chromatin immunoprecipitation.
The third Aim will use DNA microarrays, to produce a picture of the genes regulated by HNF-4 before and after injury. An in vitro model of acute phase induction will also be used to allow direct manipulation of HNF-4 and to measure its effects on acute phase transcriptional events. These studies will elucidate the mechanisms of HNF-4 functions and test, the importance of HNF-4's modifications. It will establish what transcriptional events are common to the early phase of the APR, when normal liver function is modified, and the liver prepares for subsequent massive modulation of protein production.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK064945-02
Application #
6930357
Study Section
Surgery, Anesthesiology and Trauma Study Section (SAT)
Program Officer
Doo, Edward
Project Start
2004-08-01
Project End
2009-06-30
Budget Start
2005-07-01
Budget End
2006-06-30
Support Year
2
Fiscal Year
2005
Total Cost
$358,530
Indirect Cost
Name
Boston University
Department
Surgery
Type
Schools of Medicine
DUNS #
604483045
City
Boston
State
MA
Country
United States
Zip Code
02118
Wang, Zhongyan; Burke, Peter A (2013) The role of microRNAs in hepatocyte nuclear factor-4alpha expression and transactivation. Biochim Biophys Acta 1829:436-42
Bauzá, Graciela; Miller, Glenn; Kaseje, Neema et al. (2012) Injury-induced changes in liver specific transcription factors HNF-1? and HNF-4?. J Surg Res 175:298-304
Wang, Zhongyan; Salih, Erdjan; Burke, Peter A (2011) Quantitative analysis of cytokine-induced hepatocyte nuclear factor-4? phosphorylation by mass spectrometry. Biochemistry 50:5292-300
Bauza, Graciela; Miller, Glenn; Kaseje, Neema et al. (2011) The effects of injury magnitude on the kinetics of the acute phase response. J Trauma 70:948-53
Wang, Zhongyan; Burke, Peter A (2010) Hepatocyte nuclear factor-4* interacts with other hepatocyte nuclear factors in regulating transthyretin gene expression. FEBS J 277:4066-75
Wang, Zhongyan; Burke, Peter A (2008) Modulation of hepatocyte nuclear factor-4alpha function by the peroxisome-proliferator-activated receptor-gamma co-activator-1alpha in the acute-phase response. Biochem J 415:289-96
Wang, Zhongyan; Burke, Peter A (2007) Effects of hepatocyte nuclear factor-4alpha on the regulation of the hepatic acute phase response. J Mol Biol 371:323-35