This proposal seeks to further study a fundamental problem of surgical biology, that is, liver regeneration using innovative techniques for the study of the mechanisms involved. The stated hypotheses of this proposal include: 1) recombinant adenoviruses are the most efficient and broadly-applicable liver-directed gene transfer vectors; 2) DNA binding proteins, especially NK-(B and STAT-3 have assumed an important role in liver regeneration and are likely to also be important in adenoviral gene expression in liver; 3) the prolonged gene expression seen in regenerating liver is not due to an impaired immune response; 4) gene transfer can be used to introduce biologically important genes, specifically keratinocyte growth factor and hepatocyte growth factor, into hepatocytes in vitro, and normal liver in vivo, allowing the elucidation of mechanisms responsible for liver proliferation; and 5) gene transfer can be used to study the physiology and pathophysiology of regeneration and glucose metabolism in the liver.
The Specific Aims of this proposal include: 1) to analyze the patterns of vector efficiency, gene expression and host immune response in normal, regenerating, and carbon tetrachloride-treated mouse liver using recombinant adenoviruses containing marker genes; 2) to study the expression of nuclear binding proteins in isolated mouse hepatocytes, normal liver, liver transduced with recombinant adenovirus, and regenerating liver; 3) to study the role of the anti-apoptosis factors Bcl-2, and Bcl-XL, in the prolonged recombinant adenovirus-mediated gene transfer seen in regenerating liver; 4) to analyze the ability of hepatocytes marked with the (-galactosidase transgene to engraft in mouse liver in the presence or absence of recombinant adenoviruses expressing keratinocyte growth factor and/or hepatocyte growth factor; and 5) to study the effects of liver-directed recombinant adenovirus mediated overexpression of glucokinase on glucose homeostasis and hepatic regeneration in mice made diabetic by streptozotocin after sham or 70% hepatectomy.
