Bone marrow transplantation into hemochromatotic mice decreases hepatic and duodenal iron overload.

Human hereditary hemochromatosis is a disorder of iron homeostasis characterized by increased absorption of iron and its deposition in parenchymal organs. The maintenance of iron homeostasis is regulated by molecules involved in the absorption, transport, storage and redox of iron. The potential of hematopoietic stem cell therapy for liver diseases has been studied in some experimental animal models. Our objective was to evaluate the effect of bone marrow transplantation from wild type mice on the status of iron overload in Hfe knockout hemochromatotic mice (Hfe(-/-)). The transplanted cells were detected in the liver (11% of the total cells) and characterized as hepatocytes and myofibroblasts. They were also detected in the duodenum and characterized as myofibroblasts. The iron content in the Hfe(-/-) mice descended 2.9-fold in the liver and 2.4-fold in the duodenum 6 months after transplantation. Non-significant changes of relative mRNA abundance of genes of iron metabolism were observed in the liver and duodenum of Hfe(-/-) transplanted mice. At 6 months after transplantation the proportion of Hfe mRNA in Hfe(-/-) mice reached 3.8% of the levels in wild type mice in the liver and 1.6% in the duodenum. In conclusion, adult stem cells from bone marrow transplant were able to differentiate into hepatocytes and myofibroblasts in hemochromatotic mice. Bone marrow transplantation assisted in reducing the iron overload in this murine model of hemochromatosis. These findings might contribute to the knowledge of pathways involved in the regulatory system of iron homeostasis.

Bone marrow-derived cells promote liver regeneration in mice with erythropoietic protoporphyria.

BACKGROUND: Bone marrow transplantation can reverse hepatic protoporphyrin accumulation and prevent the hepatobiliary complications characteristic of erythropoietic protoporphyria. The aim of this study was to assess the recruitment capacity of bone marrow cells in the damaged liver and their possible contribution to the improved or recovered hepatic function in a murine model of erythropoietic protoporphyria (EPP). METHODS: Lethally irradiated female EPP mice were transplanted with bone marrow cells from healthy male mice and were monitored during 12 or 36 weeks. Two groups of animals killed 12 weeks after transplant were also treated with granulocyte colony-stimulating factor. RESULTS: Cell transplantation decreased porphyrin contents in erythrocytes and liver. Improved hepatic structure and function and reduced hepatic fibrosis were observed, especially 36 weeks after transplant. Bone marrow-derived cells (22%-35%) were identified in the liver of recipient mice by means of fluorescence in situ hybridization (chrY-FISH) or green fluorescent protein staining and were characterized by immunofluorescence staining. The livers of recipients contained 20% to 30% myofibroblasts (alpha-smooth muscle actin-positive cells), 40% CK19-positive cells, and 10% to 28% hepatocytes (albumin-positive cells) derived from the donor bone marrow. CONCLUSIONS: Bone marrow-derived cells play a significant role in restoring and regenerating hepatic tissue in EPP mice. Hepatic repair was associated with fibrogenesis, enhanced by granulocyte colony-stimulating factor treatment, and almost normal liver structure and function was observed in the long term (36 weeks posttransplant).