Gene therapy for renal anemia in mice with polycystic kidney using an adenovirus vector encoding the human erythropoietin gene

Background Recombinant human erythropoietin (rHuEPO) is primarily used for patients with anemia associated with endstage renal disease. We evaluated the efficacy of EPO gene therapy using adenovirus vector for chronic renal failure mice expressing severe renal anemia. Methods. Recombinant HuEPO gene transfer to mesothelial cells was performed in vitro and in vivo. Recombinant replication-deficient adenoviruses containing rHuEPO cDNA (AdCMVEPO), E. coli lacZ gene (AdCMVlacZ), or an nonexogenous gene (AdNull as control vector) driven by the cytomegalovirus promotor/enhancer were constructed. The oligosaccharides associated with the rHuEPO from AdCMVEPO-treated mesothelial cells were analyzed. For in vivo study, the DBA/2FG-pcy mouse, a model for human autosomal recessive polycystic kidney disease resulting in chronic renal failure with progressive anemia, was used. Results. The sialylated oligosaccharides associated with the rHuEPO produced in AdCMVEPO-treated mesothelial cells occupied 78 +/- 0.7% of the total oligosaccharide pool. A single intraperitoneal administration of AdCMVEPO induced rHuEPO synthesis in the peritoneal cells and a marked increase in erythrocyte production. The maximal increase in hematocrit (43 +/- 4%) was observed on day 28, and it remained elevated for 40 days. Conclusion. These results indicate that intraperitoneal administration of AdCMVEPO improves renal anemia in mice with chronic renal failure and that the mesothelial cell is an appropriate target cell for gene transfer.