Targeting Hepcidin with Antisense Oligonucletides Improves Anemia Endpoints in Mice

Anemia is one of the more common blood disorders and is associated with a number of diseases, including chronic kidney disease, chronic inflammation, and certain types of cancer. Under these conditions iron is essential as it is required for erythroid progenitor cell proliferation and red cell function. Hepcidin is a liver-derived growth factor that regulates iron absorption in the GI tract and iron absorption and release in tissues. Furthermore, hepcidin overexpression has been strongly linked mechanistically as a mediator of decreased iron availability and anemia. We have utilized an antisense approach to investigate the role of hepcidin in animal models of anemia and as a potential therapeutic approach for the treatment of this disorder in humans. Second-generation 2′-O-methoxyethyl chimeric antisense oligonucleotides (ASOs) were screened in isolated primary mouse hepatocytes, followed by in vivo screening in mice, for the ability to reduce hepcidin mRNA levels. ASO treatment resulted in a reduction of hepcidin mRNA in liver which was associated with a significant increase in serum iron levels. The best hepcidin ASO was then tested in a mouse model of turpentine induced hypoferremia and anemia to determine the role of hepcidin in regulating serum iron and anemia endpoints. Mice were treated (I.P. twice/weekly) with hepcidin or control ASO for two weeks at varying doses prior to a single subcutaneous injection of turpentine. Turpentine treatment 16 hours post-injection produced a significant reduction in serum iron levels and at two weeks resulted in reduced RBC numbers, hematocrit and hemoglobin levels. Treatment with the hepcidin ASO resulted in a dose dependent improvement in all of these endpoints while the control oligonucleotide had no effect. Studies are in progress to further characterize the pharmacological activity of hepcidin ASO in additional models of anemia and results from these on-going studies will also be presented.