Cell surface serine protease matriptase-2 suppresses fetuin-A/AHSG-mediated induction of hepcidin

2015 ◽  
Vol 396 (1) ◽  
pp. 81-93 ◽  
Author(s):  
Marit Stirnberg ◽  
Eva Maurer ◽  
Katharina Arenz ◽  
Anne Babler ◽  
Willi Jahnen-Dechent ◽  
...  
Keyword(s):  
Serine Protease ◽  
Iron Homeostasis ◽  
Mrna Levels ◽  
Fetuin A ◽  
Hepcidin Expression ◽  
Morphogenetic Protein ◽  
Protease Substrate ◽  
Transmembrane Serine Protease ◽  
Chain Form

Abstract Matriptase-2 is a type II transmembrane serine protease controlling the expression of hepcidin, the key regulator of iron homeostasis. By cleaving hemojuvelin, matriptase-2 suppresses bone morphogenetic protein/sons of mothers against decapentaplegic signaling. So far, the only known putative substrates of matriptase-2 are hemojuvelin and matriptase-2 itself. In this study, fetuin-A (α2-Heremans-Schmid glycoprotein) was identified in vitro as a substrate of matriptase-2. The protease–substrate interaction was validated by isolating matriptase-2 via the affinity to fetuin-A. Fetuin-A is a liver-derived plasma protein with multiple functions, which is proteolytically processed to yield a disulfide-linked two-chain form. In co-transfected cells, a matriptase-2-dependent conversion of unprocessed fetuin-A into a two-chain form was detected. Conversely, downregulation of endogenously expressed matriptase-2 stabilized fetuin-A. Arg and Lys residues located within the 40 residue spanning connecting peptide of fetuin-A were identified as cleavage sites for matriptase-2. Analysis of hepcidin expression revealed an inductive effect of fetuin-A, which was abolished by matriptase-2. Fetuin-A deficiency in mice resulted in decreased hepcidin mRNA levels. These findings implicate a role of fetuin-A in iron homeostasis and provide new insights into the mechanism of how matriptase-2 might modulate hepcidin expression.

scholarly journals Neogenin inhibits HJV secretion and regulates BMP-induced hepcidin expression and iron homeostasis

Blood ◽  
2010 ◽  
Vol 115 (15) ◽  
pp. 3136-3145 ◽  
Author(s):  
Dae-Hoon Lee ◽  
Li-Juan Zhou ◽  
Zheng Zhou ◽  
Jian-Xin Xie ◽  
Ji-Ung Jung ◽  
...  
Keyword(s):  
Iron Homeostasis ◽  
Critical Role ◽  
Bmp Signaling ◽  
Deleted In Colorectal Cancer ◽  
Hepcidin Expression ◽  
Morphogenetic Protein ◽  
Guidance Molecules ◽  
A Cell ◽  
Low Levels

Abstract Neogenin, a deleted in colorectal cancer (DCC) family member, has been identified as a receptor for the neuronal axon guidance cues netrins and repulsive guidance molecules repulsive guidance molecules (RGM). RGMc, also called hemojuvelin (HJV), is essential for iron homeostasis. Here we provide evidence that neogenin plays a critical role in iron homeostasis by regulation of HJV secretion and bone morphogenetic protein (BMP) signaling. Livers of neogenin mutant mice exhibit iron overload, low levels of hepcidin, and reduced BMP signaling. Mutant hepatocytes in vitro show impaired BMP2 induction of Smad1/5/8 phosphorylation and hepcidin expression. Neogenin is expressed in liver cells in a reciprocal pattern to that of hepcidin, suggesting that neogenin functions in a cell nonautonomous manner. Further studies demonstrate that neogenin may stabilize HJV, a glycosylphosphatidylinositol-anchored protein that interacts with neogenin and suppresses its secretion. Taken together, our results lead the hypothesis that neogenin regulates iron homeostasis via inhibiting secretion of HJV, an inhibitor of BMP signaling, to enhance BMP signaling and hepcidin expression. These results reveal a novel mechanism underlying neogenin regulation of HJV-BMP signaling.

scholarly journals Phenotypic Analysis of Mice Lacking the Tmprss2-Encoded Protease

2006 ◽  
Vol 26 (3) ◽  
pp. 965-975 ◽  
Author(s):  
Tom S. Kim ◽  
Cynthia Heinlein ◽  
Robert C. Hackman ◽  
Peter S. Nelson
Keyword(s):  
Serine Protease ◽  
Serine Proteases ◽  
Biological Activities ◽  
Type Ii ◽  
Phenotypic Analysis ◽  
Normal Prostate ◽  
Prostate Hyperplasia ◽  
Transmembrane Serine Protease

ABSTRACT Tmprss2 encodes an androgen-regulated type II transmembrane serine protease (TTSP) expressed highly in normal prostate epithelium and has been implicated in prostate carcinogenesis. Although in vitro studies suggest protease-activated receptor 2 may be a substrate for TMPRSS2, the in vivo biological activities of TMPRSS2 remain unknown. We generated Tmprss2 −/− mice by disrupting the serine protease domain through homologous recombination. Compared to wild-type littermates, Tmprss2 −/− mice developed normally, survived to adulthood with no differences in protein levels of prostatic secretions, and exhibited no discernible abnormalities in organ histology or function. Loss of TMPRSS2 serine protease activity did not influence fertility, reduce survival, result in prostate hyperplasia or carcinoma, or alter prostatic luminal epithelial cell regrowth following castration and androgen replacement. Lack of an observable phenotype in Tmprss2 −/− mice was not due to transcriptional compensation by closely related Tmprss2 homologs. We conclude that the lack of a discernible phenotype in Tmprss2 −/− mice suggests functional redundancy involving one or more of the type II transmembrane serine protease family members or other serine proteases. Alternatively, TMPRSS2 may contribute a specialized but nonvital function that is apparent only in the context of stress, disease, or other systemic perturbation.

Transmembrane prolyl 4-hydroxylase is a fourth prolyl 4-hydroxylase regulating EPO production and erythropoiesis

Blood ◽  
2012 ◽  
Vol 120 (16) ◽  
pp. 3336-3344 ◽  
Author(s):  
Anu Laitala ◽  
Ellinoora Aro ◽  
Gail Walkinshaw ◽  
Joni M. Mäki ◽  
Maarit Rossi ◽  
...  
Keyword(s):  
Cultured Cells ◽  
Mrna Level ◽  
Hypoxia Inducible Factor ◽  
Mrna Levels ◽  
Wild Type ◽  
Α Subunit ◽  
Hepcidin Expression ◽  
In The Wild ◽  
Hepcidin Mrna

AbstractAn endoplasmic reticulum transmembrane prolyl 4-hydroxylase (P4H-TM) is able to hydroxylate the α subunit of the hypoxia-inducible factor (HIF) in vitro and in cultured cells, but nothing is known about its roles in mammalian erythropoiesis. We studied such roles here by administering a HIF-P4H inhibitor, FG-4497, to P4h-tm−/− mice. This caused larger increases in serum Epo concentration and kidney but not liver Hif-1α and Hif-2α protein and Epo mRNA levels than in wild-type mice, while the liver Hepcidin mRNA level was lower in the P4h-tm−/− mice than in the wild-type. Similar, but not identical, differences were also seen between FG-4497–treated Hif-p4h-2 hypomorphic (Hif-p4h-2gt/gt) and Hif-p4h-3−/− mice versus wild-type mice. FG-4497 administration increased hemoglobin and hematocrit values similarly in the P4h-tm−/− and wild-type mice, but caused higher increases in both values in the Hif-p4h-2gt/gt mice and in hematocrit value in the Hif-p4h-3−/− mice than in the wild-type. Hif-p4h-2gt/gt/P4h-tm−/− double gene-modified mice nevertheless had increased hemoglobin and hematocrit values without any FG-4497 administration, although no such abnormalities were seen in the Hif-p4h-2gt/gt or P4h-tm−/− mice. Our data thus indicate that P4H-TM plays a role in the regulation of EPO production, hepcidin expression, and erythropoiesis.

scholarly journals Inhibition of bone morphogenetic protein signaling attenuates anemia associated with inflammation

Blood ◽  
2011 ◽  
Vol 117 (18) ◽  
pp. 4915-4923 ◽  
Author(s):  
Andrea U. Steinbicker ◽  
Chetana Sachidanandan ◽  
Ashley J. Vonner ◽  
Rushdia Z. Yusuf ◽  
Donna Y. Deng ◽  
...  
Keyword(s):  
Bone Morphogenetic Protein ◽  
Iron Homeostasis ◽  
Iron Bioavailability ◽  
Bmp Signaling ◽  
Neoplastic Disease ◽  
Type I ◽  
Hepcidin Expression ◽  
Hepatic Expression ◽  
Morphogenetic Protein ◽  
Anemia Of Inflammation

Abstract Anemia of inflammation develops in settings of chronic inflammatory, infectious, or neoplastic disease. In this highly prevalent form of anemia, inflammatory cytokines, including IL-6, stimulate hepatic expression of hepcidin, which negatively regulates iron bioavailability by inactivating ferroportin. Hepcidin is transcriptionally regulated by IL-6 and bone morphogenetic protein (BMP) signaling. We hypothesized that inhibiting BMP signaling can reduce hepcidin expression and ameliorate hypoferremia and anemia associated with inflammation. In human hepatoma cells, IL-6–induced hepcidin expression, an effect that was inhibited by treatment with a BMP type I receptor inhibitor, LDN-193189, or BMP ligand antagonists noggin and ALK3-Fc. In zebrafish, the induction of hepcidin expression by transgenic expression of IL-6 was also reduced by LDN-193189. In mice, treatment with IL-6 or turpentine increased hepcidin expression and reduced serum iron, effects that were inhibited by LDN-193189 or ALK3-Fc. Chronic turpentine treatment led to microcytic anemia, which was prevented by concurrent administration of LDN-193189 or attenuated when LDN-193189 was administered after anemia was established. Our studies support the concept that BMP and IL-6 act together to regulate iron homeostasis and suggest that inhibition of BMP signaling may be an effective strategy for the treatment of anemia of inflammation.

scholarly journals Dopamine Is a Siderophore-Like Iron Chelator That PromotesSalmonella entericaSerovar Typhimurium Virulence in Mice

mBio ◽  
2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Stefanie Dichtl ◽  
Egon Demetz ◽  
David Haschka ◽  
Piotr Tymoszuk ◽  
Verena Petzer ◽  
...  
Keyword(s):  
Bacterial Growth ◽  
Iron Uptake ◽  
Iron Homeostasis ◽  
Iron Acquisition ◽  
Lipocalin 2 ◽  
Intracellular Iron ◽  
Content Type ◽  
Hepcidin Expression

ABSTRACTWe have recently shown that the catecholamine dopamine regulates cellular iron homeostasis in macrophages. As iron is an essential nutrient for microbes, and intracellular iron availability affects the growth of intracellular bacteria, we studied whether dopamine administration impacts the course ofSalmonellainfections. Dopamine was found to promote the growth ofSalmonellaboth in culture and within bone marrow-derived macrophages, which was dependent on increased bacterial iron acquisition. Dopamine administration to mice infected withSalmonella entericaserovar Typhimurium resulted in significantly increased bacterial burdens in liver and spleen, as well as reduced survival. The promotion of bacterial growth by dopamine was independent of the siderophore-binding host peptide lipocalin-2. Rather, dopamine enhancement of iron uptake requires both the histidine sensor kinase QseC and bacterial iron transporters, in particular SitABCD, and may also involve the increased expression of bacterial iron uptake genes. Deletion or pharmacological blockade of QseC reduced but did not abolish the growth-promoting effects of dopamine. Dopamine also modulated systemic iron homeostasis by increasing hepcidin expression and depleting macrophages of the iron exporter ferroportin, which enhanced intracellular bacterial growth.Salmonellalacking all central iron uptake pathways failed to benefit from dopamine treatment. These observations are potentially relevant to critically ill patients, in whom the pharmacological administration of catecholamines to improve circulatory performance may exacerbate the course of infection with siderophilic bacteria.IMPORTANCEHere we show that dopamine increases bacterial iron incorporation and promotesSalmonellaTyphimurium growth bothin vitroandin vivo. These observations suggest the potential hazards of pharmacological catecholamine administration in patients with bacterial sepsis but also suggest that the inhibition of bacterial iron acquisition might provide a useful approach to antimicrobial therapy.

scholarly journals 3-Amidinophenylalanine-derived matriptase inhibitors can modulate hepcidin production in vitro

2019 ◽  
Vol 393 (3) ◽  
pp. 511-520
Author(s):  
Erzsébet Pászti-Gere ◽  
Gergely Szombath ◽  
Michael Gütschow ◽  
Torsten Steinmetzer ◽  
András Székács
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Cell Cultures ◽  
Iron Homeostasis ◽  
Binding Mode ◽  
Type Ii ◽  
Transmembrane Serine Protease ◽  
Vitro Data ◽  
In Vitro Data

Abstract Matriptase-2 (MT-2) is a type II transmembrane serine protease and predominantly attached to the surface of hepatocytes. MT-2 decreases the production of hepcidin, a key regulator of iron homeostasis. In this study, the effects of four 3-amidinophenylalanine-derived combined matriptase-1/matriptase-2 (MT-1/2) inhibitors (MI-432, MI-441, MI-460, and MI-461) on hepcidin production were investigated in hepatocyte mono- and hepatocyte-Kupffer cell co-cultures. In MI-461-treated cell cultures, the extracellular hydrogen peroxide contents and the interleukin-6 and -8 (IL-6 and IL-8) levels were determined and compared to controls. Hepcidin overproduction was observed in hepatocytes upon treatment with MI-432, MI-441 and MI-461 at 50 μM. In contrast, extracellular hydrogen peroxide levels were not elevated significantly after matriptase inhibition with MI-461. Furthermore, MI-461 did not induce increases in IL-6 and IL-8 levels in these hepatic models. A model of the binding mode of inhibitor MI-461 in complex with MT-2 revealed numerous polar contacts contributing to the nanomolar potency of this compound. Based on the in vitro data on hepcidin regulation, treatment with MI-461 might be valuable in pathological states of iron metabolism without causing excessive oxidative stress.

Sensing Iron: Reciprocal Regulation of Hepcidin mRNA by Soluble and Cell-Associated Hemojuvelin.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 512-512
Author(s):  
Lan Lin ◽  
Y. Paul Goldberg ◽  
Tomas Ganz
Keyword(s):  
Iron Homeostasis ◽  
Genomic Sequence ◽  
Hepatoma Cell ◽  
Hepatoma Cell Line ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Human Hepatoma Cell ◽  
Hepcidin Expression ◽  
Juvenile Hemochromatosis ◽  
Hepcidin Mrna

Abstract Human genetic studies identified HJV (also called HFE2) as the major cause for juvenile hemochromatosis (JH). Patients with HJV hemochromatosis have low urinary levels of hepcidin, the principal iron-regulatory hormone secreted by the liver. We attempted to establish the specific roles of HJV in iron metabolism, especially its relationship with hepcidin. Translation of the genomic sequence indicated a C-terminal GPI anchor for the protein product of HJV, hemojuvelin. This suggested that hemojuvelin may have either a soluble or a cell-associated form. In human hepatoma cell line Hep3B, knockdown of cellular HJV by siRNA decreased hepcidin expression, independently of the IL-6 pathway. Intriguingly, the addition of recombinant soluble hemojuvelin (rs-hemojuvelin) also suppressed hepcidin expression in primary human hepatocytes, in a log-linear dose-dependent manner, suggesting competition between soluble and cell-associated forms of hemojuvelin. Soluble hemojuvelin was found in human sera at concentrations similar to those required to suppress hepcidin mRNA in vitro. In cells engineered to express hemojuvelin, soluble hemojuvelin release was progressively inhibited by increasing iron or holotransferrin concentrations. Our study suggests that soluble and cell-associated hemojuvelin reciprocally regulate hepcidin mRNA levels, and that hemojuvelin may serve as a molecular messenger for iron homeostasis. Even in hepatocytes stimulated with IL-6, we observed strong suppression of hepcidin mRNA by rs-hemojuvelin. If rs-hemojuvelin or its active fragments also suppress hepcidin production in vivo, they could be used to alleviate anemia of inflammation.

Inhibition of Hamp1 Expression by TMPRSS6, GDF15, PIAS4 and SMAD6 Utilize Several Target Sites in the Hamp1 Promoter

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3838-3838
Author(s):  
Jaroslav Truksa ◽  
Pauline Lee ◽  
Ernest Beutler
Keyword(s):  
Transcription Factors ◽  
Bone Morphogenetic Proteins ◽  
Iron Homeostasis ◽  
Negative Regulator ◽  
Luciferase Reporter ◽  
Reporter Expression ◽  
Hepcidin Expression ◽  
Double Deletion ◽  
Bmp Pathway ◽  
Transmembrane Serine Protease

Abstract Hepcidin, the key regulator of iron homeostasis, is up-regulated by iron excess, bone morphogenetic proteins (BMPs) and inflammatory cytokines and down-regulated by hypoxia and anemia. Known positive regulators at the level of transcription factors include SMAD1/4, STAT3 and CEBPα. In this study, we focused on negative regulators of hepcidin regulation: Matriptase II/TMPRSS6 (Transmembrane serine protease 6, a recently identified negative regulator in which disruption leads to anemia in mice as well in humans); Protein inhibitor of activated STATs no. 4 (PIAS4); Growth and differentiation factor 15 (GDF15, a potential erythroid negative regulator); and SMAD6 (Mothers against decapentaplegic homolog 6, an inhibitory SMAD blocking the SMAD/BMP pathway). All tested inhibitors significantly decreased expression of the luciferase reporter under the control of 2.5 Kb murine Hamp1 promoter with GDF15 and PIAS4 Hamp1 specific since none of the inhibitors were able to reduce expression of the luciferase reporter under the control of the murine Hamp2 promoter. Inhibition of the luciferase reporter under the control of the 2.5 Kb murine Hamp1 promoter by SMAD6, unlike TMPRSS6, PIAS4 and GDF15, did not require liver specific transcription factors since the inhibition could also be observed in transfected HEK293T cells. GDF15, PIAS4, TMPRSS6 and SMAD6 all reduced basal level expression of the luciferase reporter under the control of the 2.5 Kb murine Hamp1 promoter as well as the total level of reporter expression induced by IL-6 and BMP-4. Nevertheless, GDF15 did not affect responsiveness (fold induction) to IL-6 and BMP-4. PIAS4 and TMPRSS6 inhibited responsiveness to IL-6 but had little effect on responsiveness to BMP-4. In contrast, SMAD6 did not affect responsiveness to IL-6 but reduced responsiveness to BMP-4. Deletion of the −140 bp −260 bp region of the murine Hamp1 or double deletion of the BMP-RE1 and BMP-RE2 motifs severely reduced the ability of all inhibitors to reduce reporter expression. Deletion of the STAT site abrogated PIAS4 inhibition while deletion of either BMP-RE1 or BMP-RE2 motifs alone partially reduced inhibition by TMPRSS6 and SMAD6. We conclude that there are several independent pathways that inhibit hepcidin expression.

scholarly journals Skeletal muscle hemojuvelin is dispensable for systemic iron homeostasis

Blood ◽  
2011 ◽  
Vol 117 (23) ◽  
pp. 6319-6325 ◽  
Author(s):  
Wenjie Chen ◽  
Franklin W. Huang ◽  
Tomasa Barrientos de Renshaw ◽  
Nancy C. Andrews
Keyword(s):  
Skeletal Muscle ◽  
Iron Homeostasis ◽  
Iron Absorption ◽  
Conditional Knockout ◽  
Dietary Iron ◽  
Iron Release ◽  
Hepcidin Expression ◽  
Morphogenetic Protein ◽  
Smad Signaling Pathway ◽  
Very High

Abstract Hepcidin, a hormone produced mainly by the liver, has been shown to inhibit both intestinal iron absorption and iron release from macrophages. Hemojuvelin, a glycophosphatidyl inositol–linked membrane protein, acts as a bone morphogenetic protein coreceptor to activate hepcidin expression through a SMAD signaling pathway in hepatocytes. In the present study, we show in mice that loss of hemojuvelin specifically in the liver leads to decreased liver hepcidin production and increased tissue and serum iron levels. Although it does not have any known function outside of the liver, hemojuvelin is expressed at very high levels in cardiac and skeletal muscle. To explore possible roles for hemojuvelin in skeletal muscle, we analyzed conditional knockout mice that lack muscle hemojuvelin. The mutant animals had no apparent phenotypic abnormalities. We found that systemic iron homeostasis and liver hepcidin expression were not affected by loss of hemojuvelin in skeletal muscle regardless of dietary iron content. We conclude that, in spite of its expression pattern, hemojuvelin is primarily important in the liver.

scholarly journals Expression of Bone Morphogenetic Protein Receptor (BMPR) during Perinatal Ovary Development and Primordial Follicle Formation in the Hamster: Possible Regulation by FSH

Endocrinology ◽  
2008 ◽  
Vol 150 (4) ◽  
pp. 1886-1896 ◽  
Author(s):  
Cheng Wang ◽  
Shyamal K. Roy
Keyword(s):  
Bone Morphogenetic Protein ◽  
Somatic Cells ◽  
Primordial Follicle ◽  
Ovary Development ◽  
Mrna Levels ◽  
Primordial Follicles ◽  
Bone Morphogenetic Protein Receptor ◽  
Protein Receptor ◽  
Morphogenetic Protein

To understand whether bone morphogenetic protein plays any role in the formation of primordial follicles in the hamster, we examined the temporal and spatial expression of bone morphogenetic protein receptor (BMPR) mRNA and protein in embryonic (E) 13 through postnatal day (P) 15 ovarian cells and a possible regulation by FSH during the formation of primordial follicles on P8. BMPRIA and BMPRII mRNA levels were significantly higher than that of BMPR1B throughout ovary development. BMPRIA and BMPRII mRNA levels increased significantly on E14 and declined by P5 through P6. Whereas BMPRII mRNA increased again by P7, BMPRIA mRNA levels increased through P8 concurrent with primordial follicle formation. In contrast, BMPRIB mRNA levels increased greater than 10-fold on P7-9, with a further 3-fold increase by P10. BMPR proteins were low in the somatic cells and oocytes on E13 but increased progressively during postnatal development. BMPR expression in somatic cells increased markedly on P8. Whereas BMPRII expression declined by P10 and remained steady thereafter, BMPRIA protein expression fluctuated until P15 when it became low and steady. Overall, BMPRIB immunoreactivity also declined by P10 and then remained low in the interstitial cells through P15. FSH antiserum treatment on E12 significantly attenuated receptor mRNA and protein levels by P8, but equine chorionic gonadotropin replacement on P1 reversed the inhibition. Furthermore, FSH in vitro up-regulated BMPR levels in P4 ovaries. This unique pattern of BMPR expression in the oocytes and somatic cells during perinatal ovary development suggests that BMP may play a regulatory role in primordial follicle formation. Furthermore, FSH may regulate BMP action by modulating the expression of its receptors.

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