Reciprocal gene expression of rat fibroglycan and β-actin during the course of regeneration after D-galactosamine liver injury

Fibroglycan (FG) is a major heparan sulfate proteoglycan (HSPG) in the rat liver that is mainly distributed on the surface of the hepatocytes. HSPG may play some important roles in the regeneration of liver by interacting with various growth factors such as bFGF and HB-EGF. However, little is known about the function of FG. We reported that after injury caused by D-galactosamine, regeneration started on the following day and peaked on day 2. To clarify the function of FG in liver regeneration, we investigated the gene expression of FG during regeneration after D-galactosamine injury. Materials and Methods: Rats were given D-galactosamine on day 0. Liver RNA was collected from day 0 to day 7. The gene expression of FG and β-actin (as a representative cytoskeleton) was examined by Northern and/or Slot blotting. Results: FG gene expression was markedly decreased on day 2, but totally recovered on day 3. In contrast, β-actin gene expression was markedly increased on day 2 and returned to the normal level on day 3. Expression of the FG and β-actin genes was reciprocal. Conclusion: FG expression is transiently suppressed when cytoskeleton gene expression is enhanced at the early phase of liver regeneration.