Heart Ferroportin Protein Content Is Regulated by Heart Iron Concentration and Systemic Hepcidin Expression.

The purpose of the study was to investigate the expression of ferroportin protein following treatments that affect systemic hepcidin. Administration of erythropoietin to C57BL/6J mice decreased systemic hepcidin expression; it also increased heart ferroportin protein content, determined by immunoblot in the membrane fraction, to approximately 200% of control values. This increase in heart ferroportin protein is very probably caused by a decrease in systemic hepcidin expression, in accordance with the classical regulation of ferroportin by hepcidin.

Effect of Erythropoietin on the Expression of Murine Transferrin Receptor 2.

Erythropoietin (EPO) downregulates hepcidin expression to increase the availability of iron; the downregulation of hepcidin is mediated by erythroferrone (ERFE) secreted by erythroblasts. Erythroblasts also express transferrin receptor 2 (TFR2); however, the possible role of TFR2 in hepcidin downregulation is unclear. The purpose of the study was to correlate liver expression of hepcidin with the expression of ERFE and TFR2 in murine bone marrow and spleen at 4, 16, 24, 48, 72 and 96 h following administration of a single dose of EPO.

Matriptase-2 and Hemojuvelin in Hepcidin Regulation: In Vivo Immunoblot Studies in Mice.

Matriptase-2, a serine protease expressed in hepatocytes, is a negative regulator of hepcidin expression. The purpose of the study was to investigate the interaction of matriptase-2 with hemojuvelin protein in vivo. Mice lacking the matriptase-2 proteolytic activity ( mice) display decreased content of hemojuvelin protein.

Effect of erythropoietin administration on proteins participating in iron homeostasis in Tmprss6-mutated mask mice.

Tmprss6-mutated mask mice display iron deficiency anemia and high expression of hepcidin. The aim of the study was to determine the effect of erythropoietin administration on proteins participating in the control of iron homeostasis in the liver and spleen in C57BL/6 and mask mice. Administration of erythropoietin for four days at 50 IU/mouse/day increased hemoglobin and hematocrit in C57BL/6 mice, no such increase was seen in mask mice.

Erythropoietin administration increases splenic erythroferrone protein content and liver TMPRSS6 protein content in rats.

Erythroferrone (ERFE) and TMPRSS6 are important proteins in the regulation of iron metabolism. The objective of the study was to examine splenic ERFE and liver TMPRSS6 synthesis in rats treated with a combination of iron and erythropoietin (EPO). EPO was administered to female Wistar rats at 600U/day for four days, iron-pretreated rats received 150mg of iron before EPO treatment.

Effect of Erythropoietin, Iron Deficiency and Iron Overload on Liver Matriptase-2 (TMPRSS6) Protein Content in Mice and Rats.

Matriptase-2 (TMPRSS6) is an important negative regulator of hepcidin expression; however, the effects of iron overload or accelerated erythropoiesis on liver TMPRSS6 protein content in vivo are largely unknown. We determined TMPRSS6 protein content in plasma membrane-enriched fractions of liver homogenates by immunoblotting, using a commercial antibody raised against the catalytic domain of TMPRSS6. Plasma membrane-enriched fractions were obtained by centrifugation at 3000 g and washing.