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 (mask mice) display decreased content of hemojuvelin protein. Vice versa, the absence of hemojuvelin results in decreased liver content of matriptase-2, indicating that the two proteins interact. To further characterize the role of matriptase-2, we investigated iron metabolism in mask mice fed experimental diets. Administration of iron-enriched diet increased liver iron stores as well as hepcidin expression. Treatment of iron-overloaded mask mice with erythropoietin increased hemoglobin and hematocrit, indicating that the response to erythropoietin is intact in mask mice. Feeding of an iron-deficient diet to mask mice significantly increased spleen weight as well as the splenic content of erythroferrone and transferrin receptor proteins, indicating stress erythropoiesis. Liver hepcidin expression was decreased; expression of Id1 was not changed. Overall, the results suggest a complex interaction between matriptase-2 and hemojuvelin, and demonstrate that hepcidin can to some extent be regulated even in the absence of matriptase-2 proteolytic activity.

• MeSH
• dietní železo farmakologie   MeSH
• erythropoetin farmakologie   MeSH
• GPI-vázané proteiny biosyntéza   nedostatek   genetika   fyziologie   MeSH
• hepcidiny biosyntéza   genetika   MeSH
• inhibitor diferenciace 1 biosyntéza   genetika   MeSH
• játra metabolismus   MeSH
• kostní morfogenetický protein 6 biosyntéza   genetika   MeSH
• membránové proteiny nedostatek   genetika   fyziologie   MeSH
• myši inbrední C57BL MeSH
• myši knockoutované MeSH
• myši MeSH
• orgánová specificita MeSH
• přetížení železem metabolismus   MeSH
• promotorové oblasti (genetika) genetika   MeSH
• protein hemochromatózy biosyntéza   nedostatek   genetika   fyziologie   MeSH
• proteinové domény MeSH
• regulace genové exprese účinky léků   MeSH
• rekombinantní proteiny metabolismus   MeSH
• serinové endopeptidasy nedostatek   genetika   fyziologie   MeSH
• slezina metabolismus   MeSH
• železo nedostatek   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

AIMS: Endoglin is a transmembrane glycoprotein, that plays an important role in regulating endothelium. Proteolytic cleavage of membrane endoglin releases soluble endoglin (sEng), whose increased plasma levels have been detected in diseases related to the cardiovascular system. It was proposed that sEng might damage vascular endothelium, but detailed information about the potential mechanisms involved is not available. Thus, we hypothesized that sEng contributes to endothelial dysfunction, leading to a pro-inflammatory phenotype by a possible modulation of the TGF-β and/or inflammatory pathways. MAIN METHODS: Human umbilical vein endothelial cells (HUVECs) and Human embryonic kidney cell line (HEK293T) were treated with different sEng concentration and time in order to reveal possible effect on biomarkers of inflammation and TGF-β signaling. IL6 and NFκB reporter luciferase assays, quantitative real-time PCR analysis, Western blot analysis and immunofluorescence flow cytometry were used. KEY FINDINGS: sEng treatment results in activation of NF-κB/IL-6 expression, increased expression of membrane endoglin and reduced expression of Id-1. On the other hand, no significant effects on other markers of endothelial dysfunction and inflammation, including eNOS, peNOS(S1177), VCAM-1, COX-1, COX-2 and ICAM-1 were detected. SIGNIFICANCE: As a conclusion, sEng treatment resulted in an activation of NF-κB, IL-6, suggesting activation of pro-inflammatory phenotype in endothelial cells. The precise mechanism of this activation and its consequence remains to be elucidated. A combined treatment of sEng with other cardiovascular risk factors will be necessary in order to reveal whether sEng is not only a biomarker of cardiovascular diseases, but also a protagonist of endothelial dysfunction.

• MeSH
• endoglin biosyntéza   MeSH
• endoteliální buňky pupečníkové žíly (lidské) metabolismus   MeSH
• HEK293 buňky MeSH
• inhibitor diferenciace 1 biosyntéza   MeSH
• interleukin-6 biosyntéza   MeSH
• lidé MeSH
• NF-kappa B biosyntéza   MeSH
• regulace genové exprese * MeSH
• rozpustnost MeSH
• signální transdukce * MeSH
• zánět chemicky indukované   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Matriptase-2, a membrane protein encoded by the Tmprss6 gene, is a negative regulator of hepcidin expression. Although matriptase-2 has been proposed to cleave membrane hemojuvelin, we have recently found decreased hemojuvelin protein levels in Tmprss6 -/- mice. The purpose of this study was to confirm this observation by determining hemojuvelin protein levels in another strain of mice with disrupted Tmprss6 gene, and to determine the effect of matriptase-2 deficiency on the expression of other membrane proteins participating in the bone morphogenetic protein signal transduction. Mask mice, which lack the proteolytic domain of matriptase-2, displayed decreased liver hemojuvelin protein content, while Id1 mRNA level, an indicator of hemojuvelin-dependent signal transduction, was increased. Protein levels of bone morphogenetic protein receptors Alk3 and Acvr2a were unchanged, and transferrin receptor 2 and neogenin protein levels were slightly decreased. The results confirm that the loss of matriptase-2 increases bone morphogenetic protein-dependent signaling, while paradoxically decreasing liver hemojuvelin protein content. The regulation of transferrin receptor 2 protein levels by transferrin saturation was not affected in mask mice. How the loss of matriptase-2 proteolytic activity leads to decreased hemojuvelin protein levels is at present unclear.

• MeSH
• aktivinové receptory typu II metabolismus   MeSH
• down regulace MeSH
• inhibitor diferenciace 1 genetika   metabolismus   MeSH
• injekce intraperitoneální MeSH
• játra účinky léků   metabolismus   MeSH
• membránové proteiny nedostatek   genetika   metabolismus   MeSH
• messenger RNA metabolismus   MeSH
• myši inbrední C57BL MeSH
• myši knockoutované MeSH
• myši MeSH
• receptory morfogenetických kostních proteinů typu I metabolismus   MeSH
• receptory transferinu metabolismus   MeSH
• serinové endopeptidasy nedostatek   genetika   MeSH
• železo-dextranový komplex aplikace a dávkování   MeSH
• železo nedostatek   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH