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

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. Content of ERFE and TMPRSS6 proteins was determined by commercial antibodies. Iron pretreatment prevented the EPO-induced decrease in hepcidin expression. Content of phosphorylated SMAD 1,5,8 proteins was decreased in the liver by both EPO and iron plus EPO treatment. Fam132b expression in the spleen was increased both by EPO and iron plus EPO treatments; these treatments also significantly induced splenic Fam132a expression. ERFE protein content in the spleen was increased both by EPO and iron plus EPO to a similar extent. EPO administration increased TMPRSS6 content in the plasma membrane-enriched fraction of liver homogenate; in iron-pretreated rats, this increase was abolished. The results confirm that iron pretreatment prevents the EPO-induced decrease in liver Hamp expression. This effect probably occurs despite high circulating ERFE levels, since EPO-induced ERFE protein synthesis is not influenced by iron pretreatment.