Investigation of the mechanisms involved in the control of liver specific gene expression and hepatocyte differentiation.
The objective of the project is to study the regulatory proteins and genes which control the synthesis of some representative liver-specific proteins. Focus on the liver isdictated by the fact that this organ is the site of synthesis of many proteins that are crucial in the normal functioning of the organism as well as in diverse pathological states.
The project involved the study of the regulatory proteins and genes which control the synthesis of some representative liver-specific proteins such as albumin, apolipoproteins, clotting factors, acute phase proteins that are produced in response to inflammation, etc. While each of these proteins is essential for normal function, pathological states may result from the production of not only enough protein, but in some cases from too much. This explains why an understanding of the gene controlling processes is essential.
The basic knowledge that will emerge from this biotechnology project has numerous industrial and pharmaceutical applications;
Specific regulatory genes and target genes can be introduced into hepatocytes in order to generate a uniquely tailored type of hepatocyte which produces large quantities of a liver specific protein of pharmaceutical importance such as factor IX, VIII or XII;
Drugs can also be designed based on the precise knowledge of the three dimensional interaction of the regulatory proteins with its recognition site on the deoxyribonucleic acid (DNA), the interaction of the different regulatory factors (protein-protein interaction), and the interaction of a regulatory protein with an activating hormone. Such drugs may selectively promote or inhibit the attachment of a factor to its target gene and, thus may increase or decrease the transcription of the gene;
Improved hepatocyte cultures can also be used for toxicology tests that are currently performed using livers of animals. Such cultures can be generated by introducing the required regulatory genes or by changing the culture medium or the extracellular matrix to which cells attach and grow;
Some of the regulatory proteins may play a role in liver differentiation and regeneration. Drugs which modify the action of these proteins may be used to control liver regeneration.
ABSTRACT: The mechanisms which control the
expression of several liver-specific genes (alphal-AT, HP,
RBP, ALB, aPOAI) are the subject of intensive studies by us
and by others. Some of the regulatory genes which control
liver specific expression have been cloned (LF-B1, NF-1) and others (LF-Al, LF-A2, LF-B2) are the topic of ongoing research by the group in Heidelberg. The specific aims of the proposed research are: 1) To isolate and characterize several genes
involved in the transcriptional regulation of liver-specific proteins. 2) To study the mechanism of transcriptional
regulation and the functions of the regulatory genes by
reverse genetics (site directed mutagenesis and in-vitro transcription, homologous recombination, anti-sense RNA, ectopic and unregulated expression in transgenic animals). 3) To
identify and characterize the promoter elements and transacting factors involved in the transcriptional control of the regulatory genes in an attempt to define putative regulatory cascades in gene regulation. 4) To study the role of extracellular signals (matrix components and growth factors) in the regulation of liver-specific genes in advanced tissue culture systems employing different extracellular matrices employing different extracellular matrices.
Funding SchemeCSC - Cost-sharing contracts
OX1 3RE Oxford
91943 Les Ulis