title: Effect of Erythropoietin, Iron Deficiency and Iron Overload on Liver Matriptase-2 (TMPRSS6) Protein Content in Mice and Rats.
abstract: 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. TMPRSS6 was detected in the 3000 g fraction as a 120 kDa full-length protein in both mice and rats. Feeding of iron-deficient diet as well as erythropoietin treatment increased TMPRSS6 protein content in rats and mice by a posttranscriptional mechanism; the increase in TMPRSS6 protein by erythropoietin was also observed in Bmp6-mutant mice. Administration of high doses of iron to mice (200, 350 and 700 mg/kg) decreased TMPRSS6 protein content. Hemojuvelin was detected in the plasma membrane-enriched fractions of control animals as a full length protein of approximately 52 kDa; in iron deficient animals, the full length protein was partially cleaved at the N-terminus, resulting in an additional weak band of approximately 47 kDa. In livers from hemojuvelin-mutant mice, TMPRSS6 protein content was strongly decreased, suggesting that intact hemojuvelin is necessary for stable TMPRSS6 expression in the membrane. Overall, the results demonstrate posttranscriptional regulation of liver TMPRSS6 protein by iron status and erythropoietin administration, and provide support for the interaction of TMPRSS6 and hemojuvelin proteins in vivo.
authors: Institute of Pathophysiology, Charles University in Prague, First Faculty of Medicine, Prague, Czech Republic.
authors: Jana
authors: J
authors: Frýdlová
authors: Institute of Pathophysiology, Charles University in Prague, First Faculty of Medicine, Prague, Czech Republic.
authors: Petr
authors: P
authors: Přikryl
authors: Institute of Biotechnology, Laboratory of Tumour Resistance, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
authors: Jaroslav
authors: J
authors: Truksa
authors: Department of Pathology, Kidney Group, University Medical Center Utrecht, Utrecht, the Netherlands.
authors: Lucas L
authors: LL
authors: Falke
authors: Division of Medical Genetics, Department of Medicine, University of California San Diego, La Jolla, California, United States of America.
authors: Xin
authors: X
authors: Du
authors: Institute of Pathophysiology, Charles University in Prague, First Faculty of Medicine, Prague, Czech Republic.
authors: Iuliia
authors: I
authors: Gurieva
authors: Institute of Pathophysiology, Charles University in Prague, First Faculty of Medicine, Prague, Czech Republic.
authors: Martin
authors: M
authors: Vokurka
authors: Institute of Pathophysiology, Charles University in Prague, First Faculty of Medicine, Prague, Czech Republic.
authors: Jan
authors: J
authors: Krijt
mesh_terms: D018798:Anemia, Iron-Deficiency / Q000378:metabolism; D000818:Animals; D055418:Bone Morphogenetic Protein 6 / Q000235:genetics; D004195:Disease Models, Animal; D004921:Erythropoietin / Q000378:metabolism* / Q000494:pharmacology; D005260:Female; D058851:GPI-Linked Proteins; D000071020:Hemochromatosis Protein; D007501:Iron / Q000378:metabolism*; D000090463:Iron Deficiencies; D019190:Iron Overload / Q000378:metabolism*; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D009154:Mutation; D051381:Rats; D012697:Serine Endopeptidases / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism
chemical_list: D055418:Bone Morphogenetic Protein 6; D058851:GPI-Linked Proteins; C504414:HJV protein, mouse; D000071020:Hemochromatosis Protein; D008565:Membrane Proteins; D004921:Erythropoietin; D007501:Iron; D012697:Serine Endopeptidases; C467801:matriptase 2; D000254:Sodium-Potassium-Exchanging ATPase