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Xiao X, Xu Y, Moschetta GA, Yu Y, Fisher AL, Alfaro-Magallanes VM, McMillen S, Phillips S, Wang CY, Christian J, Babitt JL. BMP5 contributes to hepcidin regulation and systemic iron homeostasis in mice. Blood 2023; 142:1312-1322. [PMID: 37478395 PMCID: PMC10613724 DOI: 10.1182/blood.2022019195] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 06/14/2023] [Accepted: 06/22/2023] [Indexed: 07/23/2023] Open
Abstract
Hepcidin is the master regulator of systemic iron homeostasis. The bone morphogenetic protein (BMP) signaling pathway is a critical regulator of hepcidin expression in response to iron and erythropoietic drive. Although endothelial-derived BMP6 and BMP2 ligands have key functional roles as endogenous hepcidin regulators, both iron and erythropoietic drives still regulate hepcidin in mice lacking either or both ligands. Here, we used mice with an inactivating Bmp5 mutation (Bmp5se), either alone or together with a global or endothelial Bmp6 knockout, to investigate the functional role of BMP5 in hepcidin and systemic iron homeostasis regulation. We showed that Bmp5se-mutant mice exhibit hepcidin deficiency at age 10 days, blunted hepcidin induction in response to oral iron gavage, and mild liver iron loading when fed on a low- or high-iron diet. Loss of 1 or 2 functional Bmp5 alleles also leads to increased iron loading in Bmp6-heterozygous mice and more profound hemochromatosis in global or endothelial Bmp6-knockout mice. Moreover, double Bmp5- and Bmp6-mutant mice fail to induce hepcidin in response to long-term dietary iron loading. Finally, erythroferrone binds directly to BMP5 and inhibits BMP5 induction of hepcidin in vitro. Although erythropoietin suppresses hepcidin in Bmp5se-mutant mice, it fails to suppress hepcidin in double Bmp5- and Bmp6-mutant males. Together, these data demonstrate that BMP5 plays a functional role in hepcidin and iron homeostasis regulation, particularly under conditions in which BMP6 is limited.
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Affiliation(s)
- Xia Xiao
- Nephrology Division and Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Yang Xu
- Nephrology Division and Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Gillian A. Moschetta
- Nephrology Division and Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Yang Yu
- Nephrology Division and Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Allison L. Fisher
- Nephrology Division and Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Víctor M. Alfaro-Magallanes
- Nephrology Division and Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA
- LFE Research Group, Department of Health and Human Performance, Faculty of Physical Activity and Sport Sciences, Universidad Politécnica de Madrid, Madrid, Spain
| | - Shasta McMillen
- Nephrology Division and Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Sydney Phillips
- Nephrology Division and Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Chia-Yu Wang
- Nephrology Division and Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Jan Christian
- Division of Hematology and Hematologic Malignancies, Department of Neurobiology and Internal Medicine, University of Utah, Salt Lake City, UT
| | - Jodie L. Babitt
- Nephrology Division and Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA
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2
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Abdullah A, Herdenberg C, Hedman H. Ligand-specific regulation of transforming growth factor beta superfamily factors by leucine-rich repeats and immunoglobulin-like domains proteins. PLoS One 2023; 18:e0289726. [PMID: 37603563 PMCID: PMC10441800 DOI: 10.1371/journal.pone.0289726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 07/25/2023] [Indexed: 08/23/2023] Open
Abstract
Leucine-rich repeats and immunoglobulin-like domains (LRIG) are transmembrane proteins shown to promote bone morphogenetic protein (BMP) signaling in Caenorhabditis elegans, Drosophila melanogaster, and mammals. BMPs comprise a subfamily of the transforming growth factor beta (TGFβ) superfamily, or TGFβ family, of ligands. In mammals, LRIG1 and LRIG3 promote BMP4 signaling. BMP6 signaling, but not BMP9 signaling, is also regulated by LRIG proteins, although the specific contributions of LRIG1, LRIG2, and LRIG3 have not been investigated, nor is it known whether other mammalian TGFβ family members are regulated by LRIG proteins. To address these questions, we took advantage of Lrig-null mouse embryonic fibroblasts (MEFs) with doxycycline-inducible LRIG1, LRIG2, and LRIG3 alleles, which were stimulated with ligands representing all the major TGFβ family subgroups. By analyzing the signal mediators pSmad1/5 and pSmad3, as well as the induction of Id1 expression, we showed that LRIG1 promoted BMP2, BMP4, and BMP6 signaling and suppressed GDF7 signaling; LRIG2 promoted BMP2 and BMP4 signaling; and LRIG3 promoted BMP2, BMP4, BMP6, and GDF7 signaling. BMP9 and BMP10 signaling was not regulated by individual LRIG proteins, however, it was enhanced in Lrig-null cells. LRIG proteins did not regulate TGFβ1-induced pSmad1/5 signaling, or GDF11- or TGFβ1-induced pSmad3 signaling. Taken together, our results show that some, but not all, TGFβ family ligands are regulated by LRIG proteins and that the three LRIG proteins display differential regulatory effects. LRIG proteins thereby provide regulatory means for the cell to further diversify the signaling outcomes generated by a limited number of TGFβ family ligands and receptors.
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Affiliation(s)
- Ahmad Abdullah
- Department of Radiation Sciences, Oncology, Umeå University, Umeå, Sweden
| | - Carl Herdenberg
- Department of Radiation Sciences, Oncology, Umeå University, Umeå, Sweden
| | - Håkan Hedman
- Department of Radiation Sciences, Oncology, Umeå University, Umeå, Sweden
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Chow SYA, Nakayama K, Osaki T, Sugiyama M, Yamada M, Takeuchi H, Ikeuchi Y. Human sensory neurons modulate melanocytes through secretion of RGMB. Cell Rep 2022; 40:111366. [PMID: 36130522 DOI: 10.1016/j.celrep.2022.111366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 05/24/2022] [Accepted: 08/25/2022] [Indexed: 11/03/2022] Open
Abstract
Melanocytes are surrounded by diverse cells, including sensory neurons in our skin, but their interaction and functional importance have been poorly investigated. In this study, we find that melanocytes and nociceptive neurons contact more in human skin color patch tissue than control. Co-culture with human iPSC-derived sensory neurons significantly induces morphogenesis and pigmentation of human melanocytes. To reveal melanocyte-stimulating factors secreted from neurons, we perform proteomic analyses and identify RGMB in the sensory neuron-conditioned medium. RGMB protein induces morphogenesis and melanin production of melanocytes, demonstrating that RGMB is a melanocyte-stimulating factor released from sensory neurons. Transcriptome analysis suggests that the melanosome transport machinery can be controlled by RGMB, leading us to identify the vesicle production response of melanocytes upon RGMB treatment. This study discovers a role of sensory neurons in modulating multiple aspects of human melanocytes through secretion of a key factor: RGMB.
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Affiliation(s)
- Siu Yu A Chow
- Institute of Industrial Science, The University of Tokyo, Tokyo, Japan; Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo, Tokyo, Japan
| | - Kazuki Nakayama
- Frontier Research Center, POLA Chemical Industries, Inc., Kanagawa, Japan
| | - Tatsuya Osaki
- Institute of Industrial Science, The University of Tokyo, Tokyo, Japan; Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo, Tokyo, Japan
| | - Maki Sugiyama
- Frontier Research Center, POLA Chemical Industries, Inc., Kanagawa, Japan
| | - Maiko Yamada
- Frontier Research Center, POLA Chemical Industries, Inc., Kanagawa, Japan
| | - Hirotaka Takeuchi
- Frontier Research Center, POLA Chemical Industries, Inc., Kanagawa, Japan
| | - Yoshiho Ikeuchi
- Institute of Industrial Science, The University of Tokyo, Tokyo, Japan; Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo, Tokyo, Japan; Institute for AI and Beyond, The University of Tokyo, Tokyo, Japan.
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4
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Zhang L, Tang S, Ma Y, Liu J, Monnier P, Li H, Zhang R, Yu G, Zhang M, Li Y, Feng J, Qin X. RGMa Participates in the Blood-Brain Barrier Dysfunction Through BMP/BMPR/YAP Signaling in Multiple Sclerosis. Front Immunol 2022; 13:861486. [PMID: 35664003 PMCID: PMC9159795 DOI: 10.3389/fimmu.2022.861486] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 04/15/2022] [Indexed: 11/25/2022] Open
Abstract
The infiltration of inflammatory cells into the central nervous system (CNS) through the dysfunctional blood–brain barrier (BBB) was critical in the early stages of MS. However, the mechanisms underlying BBB dysfunction remain unknown. Repulsive guidance molecule-a (RGMa) is involved in the pathogenesis of multiple sclerosis (MS), but its role needs to be further explored. This study aimed to evaluate whether RMGa regulates BBB permeability in endothelial cells and MS, and if so, what mechanism may be involved. We created an experimental autoimmune encephalomyelitis (EAE) model in C57BL/6 mice and a human brain microvascular endothelial cell (HBMEC) culture. The permeability of the BBB is measured in response to various interventions. Our results showed that RGMa is expressed in the endothelial cells in HBMECs and EAE mice. RGMa and its signaling counterpart, bone morphogenetic protein 2 (BMP2)/bone morphogenetic protein receptor type II (BMPRII), were gradually increased as the disease progressed. Moreover, as EAE progressed and the BBB was disrupted, the downstream effector, yes-associated protein (YAP), as well as the tight junctional proteins zonula occludens 1 (ZO-1) and claudin-5, decreased significantly. The permeability assay revealed that lentivirus-induced RGMa overexpression in HBMECs caused a significant breakdown of the BBB, whereas RGMa knockdown significantly strengthens the integrity of the BBB. Furthermore, specifically activating BMPR II or inhibiting YAP based on RGMa knockdown results in a significant decrease of ZO-1 and claudin-5 in vitro. On the contrary, inhibition of BMPR II or activation of YAP after upregulating RGMa prevents the downregulation of ZO-1 and claudin-5 in HBMECs. In addition, serum-soluble RGMa (sRGMa) levels were significantly higher in MS patients, particularly in MS patients with Gd+ lesions, indicating that the BBB has been disrupted. In conclusion, this study shows that RGMa causes BBB dysfunction in endothelial cells via BMP2/BMPR II/YAP, resulting in BBB integrity disruption in MS and that it could be a novel therapeutic target for BBB permeability in MS.
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Affiliation(s)
- Lei Zhang
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Shi Tang
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Yue Ma
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Junhang Liu
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Philippe Monnier
- Donald K. Johnson Eye Institute, Krembil Research Institute, University Health Network, Toronto, ON, Canada.,Department of Ophthalmology and Vision Science, Faculty of Medicine, University of Toronto, Toronto, ON, Canada.,Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Hang Li
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Rongrong Zhang
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Gang Yu
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Mengjie Zhang
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Yongmei Li
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Jinzhou Feng
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Xinyue Qin
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
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Fisher AL, Babitt JL. Coordination of iron homeostasis by bone morphogenetic proteins: Current understanding and unanswered questions. Dev Dyn 2022; 251:26-46. [PMID: 33993583 PMCID: PMC8594283 DOI: 10.1002/dvdy.372] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 04/15/2021] [Accepted: 05/07/2021] [Indexed: 01/19/2023] Open
Abstract
Iron homeostasis is tightly regulated to balance the iron requirement for erythropoiesis and other vital cellular functions, while preventing cellular injury from iron excess. The liver hormone hepcidin is the master regulator of systemic iron balance by controlling the degradation and function of the sole known mammalian iron exporter ferroportin. Liver hepcidin expression is coordinately regulated by several signals that indicate the need for more or less iron, including plasma and tissue iron levels, inflammation, and erythropoietic drive. Most of these signals regulate hepcidin expression by modulating the activity of the bone morphogenetic protein (BMP)-SMAD pathway, which controls hepcidin transcription. Genetic disorders of iron overload and iron deficiency have identified several hepatocyte membrane proteins that play a critical role in mediating the BMP-SMAD and hepcidin regulatory response to iron. However, the precise molecular mechanisms by which serum and tissue iron levels are sensed to regulate BMP ligand production and promote the physical and/or functional interaction of these proteins to modulate SMAD signaling and hepcidin expression remain uncertain. This critical commentary will focus on the current understanding and key unanswered questions regarding how the liver senses iron levels to regulate BMP-SMAD signaling and thereby hepcidin expression to control systemic iron homeostasis.
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Affiliation(s)
| | - Jodie L Babitt
- Corresponding author: Jodie L Babitt, Division of Nephrology, Program in Membrane Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA. Mailing address: 185 Cambridge St., CPZN-8208, Boston, MA 02114. Telephone: +1 (617) 643-3181.
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6
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Pawlak JB, Blobe GC. TGF-β superfamily co-receptors in cancer. Dev Dyn 2022; 251:137-163. [PMID: 33797167 PMCID: PMC8484463 DOI: 10.1002/dvdy.338] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 03/17/2021] [Accepted: 03/22/2021] [Indexed: 01/03/2023] Open
Abstract
Transforming growth factor-β (TGF-β) superfamily signaling via their cognate receptors is frequently modified by TGF-β superfamily co-receptors. Signaling through SMAD-mediated pathways may be enhanced or depressed depending on the specific co-receptor and cell context. This dynamic effect on signaling is further modified by the release of many of the co-receptors from the membrane to generate soluble forms that are often antagonistic to the membrane-bound receptors. The co-receptors discussed here include TβRIII (betaglycan), endoglin, BAMBI, CD109, SCUBE proteins, neuropilins, Cripto-1, MuSK, and RGMs. Dysregulation of these co-receptors can lead to altered TGF-β superfamily signaling that contributes to the pathophysiology of many cancers through regulation of growth, metastatic potential, and the tumor microenvironment. Here we describe the role of several TGF-β superfamily co-receptors on TGF-β superfamily signaling and the impact on cellular and physiological functions with a particular focus on cancer, including a discussion on recent pharmacological advances and potential clinical applications targeting these co-receptors.
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Affiliation(s)
| | - Gerard C. Blobe
- Department of Medicine, Duke University Medical Center,Department of Pharmacology and Cancer Biology, Duke University Medical Center,Corresponding author: Gerard Blobe, B354 LSRC, Box 91004 DUMC, Durham, NC 27708, , 919-668-1352
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7
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Phan TL, Kim HJ, Lee SJ, Choi MC, Kim SH. Elevated RGMA Expression Predicts Poor Prognosis in Patients with Glioblastoma. Onco Targets Ther 2021; 14:4867-4878. [PMID: 34588781 PMCID: PMC8473061 DOI: 10.2147/ott.s317285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 09/10/2021] [Indexed: 11/23/2022] Open
Abstract
Background Glioblastoma (GBM) is the most aggressive type of human brain tumor with a poor prognosis and a low survival rate. Secreted proteins from tumors are recently considered as important modulators to promote tumorigenesis by communicating with microenvironments. Repulsive guidance molecule A (RGMA) was initially characterized as an axon guidance molecule after secretion in the brain during embryogenesis but has not been studied in GBM. In this study, we investigated secreted gene expression patterns and the correlation between RGMA expression and prognosis in GBM using in silico analysis. Methods RGMA mRNA levels in normal human astrocyte (NHA), human glioma cells, and GBM patient-derived glioma stem cells (GSCs) were assessed by qRT‐PCR. Patient survival analysis was performed with the Kaplan–Meier curve and univariate and multivariate analyses using publicly available datasets. The predictive roles of RGMA in progressive malignancy were evaluated using Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Gene Set Enrichment Analysis (GSEA). Results RGMA mRNA expression was elevated in glioma cells and GSCs compared with NHA and correlated with unfavorable prognosis in glioma patients. Thus, RGMA could serve as an independent predictive factor for GBM. Furthermore, the increased levels of RGMA expression and its putative receptor, neogenin (NEO1), were associated with poor patient survival rates in GBM. Conclusion We identified RGMA as an independent prognostic biomarker for progressive malignancy in glioblastoma and address the possibilities to develop novel therapeutic strategies against glioblastoma.
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Affiliation(s)
- Thi Le Phan
- Department of Animal Science, College of Agriculture and Life Sciences, Chonnam National University, Gwangju, 61186, Republic of Korea
| | - Hyun-Jin Kim
- Department of Animal Science, College of Agriculture and Life Sciences, Chonnam National University, Gwangju, 61186, Republic of Korea
| | - Suk Jun Lee
- Department of Biomedical Laboratory Science, College of Health & Medical Sciences, Cheongju University, Chungbuk, 28503, Republic of Korea
| | - Moon-Chang Choi
- Department of Biomedical Science, Chosun University, Gwangju, 61452, Republic of Korea
| | - Sung-Hak Kim
- Department of Animal Science, College of Agriculture and Life Sciences, Chonnam National University, Gwangju, 61186, Republic of Korea
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8
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Colucci S, Marques O, Altamura S. 20 years of Hepcidin: How far we have come. Semin Hematol 2021; 58:132-144. [PMID: 34389105 DOI: 10.1053/j.seminhematol.2021.05.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 05/12/2021] [Accepted: 05/31/2021] [Indexed: 12/20/2022]
Abstract
Twenty years ago the discovery of hepcidin deeply changed our understanding of the regulation of systemic iron homeostasis. It is now clear that hepcidin orchestrates systemic iron levels by controlling the amount of iron exported into the bloodstream through ferroportin. Hepcidin expression is increased in situations where systemic iron levels should be reduced, such as in iron overload and infection. Conversely, hepcidin is repressed during iron deficiency, hypoxia or expanded erythropoiesis, to increase systemic iron availability and sustain erythropoiesis. In this review, we will focus on molecular mechanisms of hepcidin regulation and on the pathological consequences of their disruption.
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Affiliation(s)
- Silvia Colucci
- Department of Pediatric Hematology, Oncology and Immunology - University of Heidelberg, Heidelberg, Germany.; Molecular Medicine Partnership Unit, EMBL and University of Heidelberg, Heidelberg, Germany
| | - Oriana Marques
- Department of Pediatric Hematology, Oncology and Immunology - University of Heidelberg, Heidelberg, Germany.; Molecular Medicine Partnership Unit, EMBL and University of Heidelberg, Heidelberg, Germany
| | - Sandro Altamura
- Department of Pediatric Hematology, Oncology and Immunology - University of Heidelberg, Heidelberg, Germany.; Molecular Medicine Partnership Unit, EMBL and University of Heidelberg, Heidelberg, Germany..
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Robinson RA, Griffiths SC, van de Haar LL, Malinauskas T, van Battum EY, Zelina P, Schwab RA, Karia D, Malinauskaite L, Brignani S, van den Munkhof MH, Düdükcü Ö, De Ruiter AA, Van den Heuvel DMA, Bishop B, Elegheert J, Aricescu AR, Pasterkamp RJ, Siebold C. Simultaneous binding of Guidance Cues NET1 and RGM blocks extracellular NEO1 signaling. Cell 2021; 184:2103-2120.e31. [PMID: 33740419 PMCID: PMC8063088 DOI: 10.1016/j.cell.2021.02.045] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 01/15/2021] [Accepted: 02/22/2021] [Indexed: 12/13/2022]
Abstract
During cell migration or differentiation, cell surface receptors are simultaneously exposed to different ligands. However, it is often unclear how these extracellular signals are integrated. Neogenin (NEO1) acts as an attractive guidance receptor when the Netrin-1 (NET1) ligand binds, but it mediates repulsion via repulsive guidance molecule (RGM) ligands. Here, we show that signal integration occurs through the formation of a ternary NEO1-NET1-RGM complex, which triggers reciprocal silencing of downstream signaling. Our NEO1-NET1-RGM structures reveal a "trimer-of-trimers" super-assembly, which exists in the cell membrane. Super-assembly formation results in inhibition of RGMA-NEO1-mediated growth cone collapse and RGMA- or NET1-NEO1-mediated neuron migration, by preventing formation of signaling-compatible RGM-NEO1 complexes and NET1-induced NEO1 ectodomain clustering. These results illustrate how simultaneous binding of ligands with opposing functions, to a single receptor, does not lead to competition for binding, but to formation of a super-complex that diminishes their functional outputs.
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Affiliation(s)
- Ross A Robinson
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Samuel C Griffiths
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Lieke L van de Haar
- Department of Translational Neuroscience, UMC Utrecht Brain Center, University Medical Center, Utrecht University, Universiteitsweg 100, 3584 CG Utrecht, the Netherlands
| | - Tomas Malinauskas
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Eljo Y van Battum
- Department of Translational Neuroscience, UMC Utrecht Brain Center, University Medical Center, Utrecht University, Universiteitsweg 100, 3584 CG Utrecht, the Netherlands
| | - Pavol Zelina
- Department of Translational Neuroscience, UMC Utrecht Brain Center, University Medical Center, Utrecht University, Universiteitsweg 100, 3584 CG Utrecht, the Netherlands
| | - Rebekka A Schwab
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Dimple Karia
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Lina Malinauskaite
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Sara Brignani
- Department of Translational Neuroscience, UMC Utrecht Brain Center, University Medical Center, Utrecht University, Universiteitsweg 100, 3584 CG Utrecht, the Netherlands
| | - Marleen H van den Munkhof
- Department of Translational Neuroscience, UMC Utrecht Brain Center, University Medical Center, Utrecht University, Universiteitsweg 100, 3584 CG Utrecht, the Netherlands
| | - Özge Düdükcü
- Department of Translational Neuroscience, UMC Utrecht Brain Center, University Medical Center, Utrecht University, Universiteitsweg 100, 3584 CG Utrecht, the Netherlands
| | - Anna A De Ruiter
- Department of Translational Neuroscience, UMC Utrecht Brain Center, University Medical Center, Utrecht University, Universiteitsweg 100, 3584 CG Utrecht, the Netherlands
| | - Dianne M A Van den Heuvel
- Department of Translational Neuroscience, UMC Utrecht Brain Center, University Medical Center, Utrecht University, Universiteitsweg 100, 3584 CG Utrecht, the Netherlands
| | - Benjamin Bishop
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Jonathan Elegheert
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - A Radu Aricescu
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK; MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - R Jeroen Pasterkamp
- Department of Translational Neuroscience, UMC Utrecht Brain Center, University Medical Center, Utrecht University, Universiteitsweg 100, 3584 CG Utrecht, the Netherlands.
| | - Christian Siebold
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK.
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Xiao X, Alfaro-Magallanes VM, Babitt JL. Bone morphogenic proteins in iron homeostasis. Bone 2020; 138:115495. [PMID: 32585319 PMCID: PMC7453787 DOI: 10.1016/j.bone.2020.115495] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 06/12/2020] [Accepted: 06/15/2020] [Indexed: 02/07/2023]
Abstract
The bone morphogenetic protein (BMP)-SMAD signaling pathway plays a central role in regulating hepcidin, which is the master hormone governing systemic iron homeostasis. Hepcidin is produced by the liver and acts on the iron exporter ferroportin to control iron absorption from the diet and iron release from body stores, thereby providing adequate iron for red blood cell production, while limiting the toxic effects of excess iron. BMP6 and BMP2 ligands produced by liver endothelial cells bind to BMP receptors and the coreceptor hemojuvelin (HJV) on hepatocytes to activate SMAD1/5/8 signaling, which directly upregulates hepcidin transcription. Most major signals that influence hepcidin production, including iron, erythropoietic drive, and inflammation, intersect with the BMP-SMAD pathway to regulate hepcidin transcription. Mutation or inactivation of BMP ligands, BMP receptors, HJV, SMADs or other proteins that modulate the BMP-SMAD pathway result in hepcidin dysregulation, leading to iron-related disorders, such as hemochromatosis and iron refractory iron deficiency anemia. Pharmacologic modulators of the BMP-SMAD pathway have shown efficacy in pre-clinical models to regulate hepcidin expression and treat iron-related disorders. This review will discuss recent insights into the role of the BMP-SMAD pathway in regulating hepcidin to control systemic iron homeostasis.
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Affiliation(s)
- Xia Xiao
- Division of Nephrology, Program in Membrane Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Víctor M Alfaro-Magallanes
- Division of Nephrology, Program in Membrane Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA; LFE Research Group, Department of Health and Human Performance, Faculty of Physical Activity and Sport Sciences, Universidad Politécnica de Madrid (UPM), Madrid, Spain
| | - Jodie L Babitt
- Division of Nephrology, Program in Membrane Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
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11
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Malinauskas T, Peer TV, Bishop B, Mueller TD, Siebold C. Repulsive guidance molecules lock growth differentiation factor 5 in an inhibitory complex. Proc Natl Acad Sci U S A 2020; 117:15620-15631. [PMID: 32576689 PMCID: PMC7354924 DOI: 10.1073/pnas.2000561117] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Repulsive guidance molecules (RGMs) are cell surface proteins that regulate the development and homeostasis of many tissues and organs, including the nervous, skeletal, and immune systems. They control fundamental biological processes, such as migration and differentiation by direct interaction with the Neogenin (NEO1) receptor and function as coreceptors for the bone morphogenetic protein (BMP)/growth differentiation factor (GDF) family. We determined crystal structures of all three human RGM family members in complex with GDF5, as well as the ternary NEO1-RGMB-GDF5 assembly. Surprisingly, we show that all three RGMs inhibit GDF5 signaling, which is in stark contrast to RGM-mediated enhancement of signaling observed for other BMPs, like BMP2. Despite their opposite effect on GDF5 signaling, RGMs occupy the BMP type 1 receptor binding site similar to the observed interactions in RGM-BMP2 complexes. In the NEO1-RGMB-GDF5 complex, RGMB physically bridges NEO1 and GDF5, suggesting cross-talk between the GDF5 and NEO1 signaling pathways. Our crystal structures, combined with structure-guided mutagenesis of RGMs and BMP ligands, binding studies, and cellular assays suggest that RGMs inhibit GDF5 signaling by competing with GDF5 type 1 receptors. While our crystal structure analysis and in vitro binding data initially pointed towards a simple competition mechanism between RGMs and type 1 receptors as a possible basis for RGM-mediated GDF5 inhibition, further experiments utilizing BMP2-mimicking GDF5 variants clearly indicate a more complex mechanism that explains how RGMs can act as a functionality-changing switch for two structurally and biochemically similar signaling molecules.
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Affiliation(s)
- Tomas Malinauskas
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, OX3 7BN Oxford, United Kingdom;
| | - Tina V Peer
- Department of Molecular Plant Physiology and Biophysics, Julius-von-Sachs Institute, University of Würzburg, 97082 Würzburg, Germany
| | - Benjamin Bishop
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, OX3 7BN Oxford, United Kingdom
| | - Thomas D Mueller
- Department of Molecular Plant Physiology and Biophysics, Julius-von-Sachs Institute, University of Würzburg, 97082 Würzburg, Germany
| | - Christian Siebold
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, OX3 7BN Oxford, United Kingdom;
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12
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Ren T, Zheng B, Huang Y, Wang S, Bao X, Liu K, Guo W. Osteosarcoma cell intrinsic PD-L2 signals promote invasion and metastasis via the RhoA-ROCK-LIMK2 and autophagy pathways. Cell Death Dis 2019; 10:261. [PMID: 30886151 PMCID: PMC6423010 DOI: 10.1038/s41419-019-1497-1] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2018] [Revised: 01/29/2019] [Accepted: 03/04/2019] [Indexed: 12/15/2022]
Abstract
Known as co-stimulatory molecule, programmed death ligand-2 (PD-L2) contributes to T-cell exhaustion by interaction with programmed death-1 (PD-1) receptor, but its tumor cell-intrinsic signal effects have been little investigated. PD-L2 expression was detected by immunohistochemistry in 18 pairs of primary osteosarcoma tissues and matching lung metastasis tissues. We also investigated the effects of PD-L2 knockdown on osteosarcoma both in vitro and in vivo. In our study, PD-L2 expression was elevated in lung metastases compared with primary osteosarcoma according to an immunohistochemistry assay. Wound-healing and transwell assays revealed that PD-L2 knockdown leaded to inhibition of migration and invasion of human osteosarcoma cells in vitro. Mechanistically, we demonstrated that PD-L2 knockdown attenuated migration and invasion by inactivating RhoA-ROCK-LIMK2 signaling, suppressing epithelial–mesenchymal transition (EMT), and inhibiting autophagy by decreasing beclin-1 expression. In support of these observations, beclin-1 knockdown also inhibited activation of the RhoA-ROCK-LIMK2 pathway, leading to autophagy inhibition-induced blockade of migration and invasion. Depletion of PD-L2 in KHOS cells markedly weakens pulmonary metastatic potential in vivo by orthotopic transplantation of nude mice. Our study reveals a pro-metastatic functional mechanism for PD-L2 in osteosarcoma. Furthermore, we demonstrate a regulatory role for PD-L2 on autophagy, as well as a relationship between autophagy and metastasis in osteosarcoma, which may represent a potential therapeutic target for osteosarcoma.
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Affiliation(s)
- Tingting Ren
- Musculoskeletal Tumor Center, Peking University People's Hospital, Beijing, People's Republic of China.,Beijing Key Laboratory of Musculoskeletal Tumor, Beijing, People's Republic of China
| | - Bingxin Zheng
- Musculoskeletal Tumor Center, Peking University People's Hospital, Beijing, People's Republic of China.,Beijing Key Laboratory of Musculoskeletal Tumor, Beijing, People's Republic of China.,Department of Orthopedic Surgery, The Affiliated Hospital of Qingdao University, Qingdao, People's Republic of China
| | - Yi Huang
- Musculoskeletal Tumor Center, Peking University People's Hospital, Beijing, People's Republic of China.,Beijing Key Laboratory of Musculoskeletal Tumor, Beijing, People's Republic of China
| | - Shidong Wang
- Musculoskeletal Tumor Center, Peking University People's Hospital, Beijing, People's Republic of China.,Beijing Key Laboratory of Musculoskeletal Tumor, Beijing, People's Republic of China
| | - Xing Bao
- Musculoskeletal Tumor Center, Peking University People's Hospital, Beijing, People's Republic of China.,Beijing Key Laboratory of Musculoskeletal Tumor, Beijing, People's Republic of China
| | - Kuisheng Liu
- Musculoskeletal Tumor Center, Peking University People's Hospital, Beijing, People's Republic of China.,Beijing Key Laboratory of Musculoskeletal Tumor, Beijing, People's Republic of China
| | - Wei Guo
- Musculoskeletal Tumor Center, Peking University People's Hospital, Beijing, People's Republic of China. .,Beijing Key Laboratory of Musculoskeletal Tumor, Beijing, People's Republic of China.
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13
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Abstract
Hepcidin, the main regulator of iron metabolism, is synthesized and released by hepatocytes in response to increased body iron concentration and inflammation. Deregulation of hepcidin expression is a common feature of genetic and acquired iron disorders: in Hereditary Hemochromatosis (HH) and iron-loading anemias low hepcidin causes iron overload, while in Iron Refractory Iron Deficiency Anemia (IRIDA) and anemia of inflammation (AI), high hepcidin levels induce iron-restricted erythropoiesis. Hepcidin expression in the liver is mainly controlled by the BMP-SMAD pathway, activated in a paracrine manner by BMP2 and BMP6 produced by liver sinusoidal endothelial cells. The BMP type I receptors ALK2 and ALK3 are responsible for iron-dependent hepcidin upregulation and basal hepcidin expression, respectively. Characterization of animal models with genetic inactivation of the key components of the pathway has suggested the existence of two BMP/SMAD pathway branches: the first ALK3 and HH proteins dependent, responsive to BMP2 for basal hepcidin activation, and the second ALK2 dependent, activated by BMP6 in response to increased tissue iron. The erythroid inhibitor of hepcidin Erythroferrone also impacts on the liver BMP-SMAD pathway although its effect is blunted by pathway hyper-activation. The liver BMP-SMAD pathway is required also in inflammation to cooperate with JAK2/STAT3 signaling for full hepcidin activation. Pharmacologic targeting of BMP-SMAD pathway components or regulators may improve the outcome of both genetic and acquired disorders of iron overload and deficiency by increasing or inhibiting hepcidin expression.
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14
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Eddowes LA, Al-Hourani K, Ramamurthy N, Frankish J, Baddock HT, Sandor C, Ryan JD, Fusco DN, Arezes J, Giannoulatou E, Boninsegna S, Chevaliez S, Owens BMJ, Sun CC, Fabris P, Giordani MT, Martines D, Vukicevic S, Crowe J, Lin HY, Rehwinkel J, McHugh PJ, Binder M, Babitt JL, Chung RT, Lawless MW, Armitage AE, Webber C, Klenerman P, Drakesmith H. Antiviral activity of bone morphogenetic proteins and activins. Nat Microbiol 2018; 4:339-351. [PMID: 30510168 DOI: 10.1038/s41564-018-0301-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 10/22/2018] [Indexed: 12/19/2022]
Abstract
Understanding the control of viral infections is of broad importance. Chronic hepatitis C virus (HCV) infection causes decreased expression of the iron hormone hepcidin, which is regulated by hepatic bone morphogenetic protein (BMP)/SMAD signalling. We found that HCV infection and the BMP/SMAD pathway are mutually antagonistic. HCV blunted induction of hepcidin expression by BMP6, probably via tumour necrosis factor (TNF)-mediated downregulation of the BMP co-receptor haemojuvelin. In HCV-infected patients, disruption of the BMP6/hepcidin axis and genetic variation associated with the BMP/SMAD pathway predicted the outcome of infection, suggesting that BMP/SMAD activity influences antiviral immunity. Correspondingly, BMP6 regulated a gene repertoire reminiscent of type I interferon (IFN) signalling, including upregulating interferon regulatory factors (IRFs) and downregulating an inhibitor of IFN signalling, USP18. Moreover, in BMP-stimulated cells, SMAD1 occupied loci across the genome, similar to those bound by IRF1 in IFN-stimulated cells. Functionally, BMP6 enhanced the transcriptional and antiviral response to IFN, but BMP6 and related activin proteins also potently blocked HCV replication independently of IFN. Furthermore, BMP6 and activin A suppressed growth of HBV in cell culture, and activin A inhibited Zika virus replication alone and in combination with IFN. The data establish an unappreciated important role for BMPs and activins in cellular antiviral immunity, which acts independently of, and modulates, IFN.
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Affiliation(s)
- Lucy A Eddowes
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Kinda Al-Hourani
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Narayan Ramamurthy
- Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, UK
| | - Jamie Frankish
- Research Group "Dynamics of Early Viral Infection and the Innate Antiviral Response", Division Virus-Associated Carcinogenesis (F170), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Hannah T Baddock
- Department of Oncology, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Cynthia Sandor
- Dementia Research Institute, Cardiff University, Cardiff, UK
| | - John D Ryan
- Centre for Liver Disease, Mater Misericordiae University Hospital, Dublin, Ireland.,Translational Gastroenterology Unit, Experimental Medicine Division, Nuffield Department of Medicine, John Radcliffe Hospital, Headington, Oxford, UK
| | - Dahlene N Fusco
- Liver Center, Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - João Arezes
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Eleni Giannoulatou
- Computational Biology Research Group, Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Sara Boninsegna
- Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, UK.,Department of Surgical Gastroenterological Science, University of Padua, Padova, Italy
| | - Stephane Chevaliez
- Liver Center, Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Benjamin M J Owens
- Translational Gastroenterology Unit, Experimental Medicine Division, Nuffield Department of Medicine, John Radcliffe Hospital, Headington, Oxford, UK
| | - Chia Chi Sun
- Program in Anemia Signaling Research, Nephrology Division, Program in Membrane Biology, and Center for Systems Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Paolo Fabris
- Department of Infectious Diseases and Tropical Medicine, San Bortolo Hospital, Vicenza, Italy
| | - Maria Teresa Giordani
- Department of Infectious Diseases and Tropical Medicine, San Bortolo Hospital, Vicenza, Italy
| | - Diego Martines
- Department of Surgical Gastroenterological Science, University of Padua, Padova, Italy
| | - Slobodan Vukicevic
- Center for Translational and Clinical Research, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - John Crowe
- Centre for Liver Disease, Mater Misericordiae University Hospital, Dublin, Ireland
| | - Herbert Y Lin
- Program in Anemia Signaling Research, Nephrology Division, Program in Membrane Biology, and Center for Systems Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Jan Rehwinkel
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Peter J McHugh
- Department of Oncology, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Marco Binder
- Research Group "Dynamics of Early Viral Infection and the Innate Antiviral Response", Division Virus-Associated Carcinogenesis (F170), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Jodie L Babitt
- Program in Anemia Signaling Research, Nephrology Division, Program in Membrane Biology, and Center for Systems Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Raymond T Chung
- Liver Center, Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Matthew W Lawless
- Experimental Medicine, UCD School of Medicine and Medical Science, Mater Misericordiae University Hospital, Dublin, Ireland
| | - Andrew E Armitage
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Caleb Webber
- Dementia Research Institute, Cardiff University, Cardiff, UK.,Department of Physiology, Anatomy & Genetics, Oxford University, Oxford, UK
| | - Paul Klenerman
- Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, UK.,Translational Gastroenterology Unit, Experimental Medicine Division, Nuffield Department of Medicine, John Radcliffe Hospital, Headington, Oxford, UK.,NIHR Biomedical Research Centre, John Radcliffe Hospital, Oxford, UK
| | - Hal Drakesmith
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK. .,Haematology Theme Oxford Biomedical Research Centre, Oxford, UK.
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15
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Abstract
The liver orchestrates systemic iron balance by producing and secreting hepcidin. Known as the iron hormone, hepcidin induces degradation of the iron exporter ferroportin to control iron entry into the bloodstream from dietary sources, iron recycling macrophages, and body stores. Under physiologic conditions, hepcidin production is reduced by iron deficiency and erythropoietic drive to increase the iron supply when needed to support red blood cell production and other essential functions. Conversely, hepcidin production is induced by iron loading and inflammation to prevent the toxicity of iron excess and limit its availability to pathogens. The inability to appropriately regulate hepcidin production in response to these physiologic cues underlies genetic disorders of iron overload and deficiency, including hereditary hemochromatosis and iron-refractory iron deficiency anemia. Moreover, excess hepcidin suppression in the setting of ineffective erythropoiesis contributes to iron-loading anemias such as β-thalassemia, whereas excess hepcidin induction contributes to iron-restricted erythropoiesis and anemia in chronic inflammatory diseases. These diseases have provided key insights into understanding the mechanisms by which the liver senses plasma and tissue iron levels, the iron demand of erythrocyte precursors, and the presence of potential pathogens and, importantly, how these various signals are integrated to appropriately regulate hepcidin production. This review will focus on recent insights into how the liver senses body iron levels and coordinates this with other signals to regulate hepcidin production and systemic iron homeostasis.
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16
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Heterologous Secretory Expression and Characterization of Dimerized Bone Morphogenetic Protein 2 in Bacillus subtilis. BIOMED RESEARCH INTERNATIONAL 2018; 2017:9350537. [PMID: 29333457 PMCID: PMC5733156 DOI: 10.1155/2017/9350537] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 10/12/2017] [Accepted: 10/30/2017] [Indexed: 11/21/2022]
Abstract
Recombinant human Bone Morphogenetic Protein 2 (rhBMP2) has important applications in the spine fusion and ortho/maxillofacial surgeries. Here we first report the secretory expression of biological active dimerized rhBMP2 from Bacillus subtilis system. The mature domain of BMP2 gene was amplified from pTz57R/BMP2 plasmid. By using pHT43 expression vector two constructs, pHT43-BMP2-M (single BMP2 gene) and pHT43-BMP2-D (two BMP2 genes coupled with a linker to produce a dimer), were designed. After primary cloning (DH5α strain) and sequence analysis, constructs were transformed into Bacillus subtilis for secretory expression. Expression conditions like media (2xYT) and temperature (30°C) were optimized. Maximum 35% and 25% secretory expression of monomer (~13 kDa) and dimer (~25 kDa), respectively, were observed on SDS-PAGE in SCK6 strain. The expression and dimeric nature of rhBMP2 were confirmed by western blot and native PAGE analysis. For rhBMP2 purification, 200 ml culture supernatant was freeze dried to 10 ml and dialyzed (Tris-Cl, pH 8.5) and Fast Protein Liquid Chromatography (6 ml, Resource Q column) was performed. The rhBMP2 monomer and dimer were eluted at 0.9 M and 0.6 M NaCl, respectively. The alkaline phosphatase assay of rhBMP2 (0, 50, 100, 200, and 400 ng/ml) was analyzed on C2C12 cells and maximum 200 ng/ml activity was observed in dose dependent manner.
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17
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Nickel J, Ten Dijke P, Mueller TD. TGF-β family co-receptor function and signaling. Acta Biochim Biophys Sin (Shanghai) 2018; 50:12-36. [PMID: 29293886 DOI: 10.1093/abbs/gmx126] [Citation(s) in RCA: 128] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 11/08/2017] [Indexed: 01/04/2023] Open
Abstract
Transforming growth factor-β (TGF-β) family members, which include TGF-βs, activins and bone morphogenetic proteins, are pleiotropic cytokines that elicit cell type-specific effects in a highly context-dependent manner in many different tissues. These secreted protein ligands signal via single-transmembrane Type I and Type II serine/threonine kinase receptors and intracellular SMAD transcription factors. Deregulation in signaling has been implicated in a broad array of diseases, and implicate the need for intricate fine tuning in cellular signaling responses. One important emerging mechanism by which TGF-β family receptor signaling intensity, duration, specificity and diversity are regulated and/or mediated is through cell surface co-receptors. Here, we provide an overview of the co-receptors that have been identified for TGF-β family members. While some appear to be specific to TGF-β family members, others are shared with other pathways and provide possible ways for signal integration. This review focuses on novel functions of TGF-β family co-receptors, which continue to be discovered.
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Affiliation(s)
- Joachim Nickel
- Universitätsklinikum Würzburg, Lehrstuhl für Tissue Engineering und Regenerative Medizin und Fraunhofer Institut für Silicatforschung (ISC), Translationszentrum "Regenerative Therapien", Röntgenring 11, D-97070 Würzburg, Germany
| | - Peter Ten Dijke
- Department of Molecular and Cell Biology and Cancer Genomics Centre Netherlands, Leiden University Medical Center, Einthovenweg 20, 2300 RC Leiden, The Netherlands
| | - Thomas D Mueller
- Lehrstuhl für molekulare Pflanzenphysiologie und Biophysik, Julius-von-Sachs Institut für Biowissenschaften, Universität Würzburg, Julius-von-Sachs-Platz 2, D-97082 Würzburg, Germany
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18
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Canali S, Wang CY, Zumbrennen-Bullough KB, Bayer A, Babitt JL. Bone morphogenetic protein 2 controls iron homeostasis in mice independent of Bmp6. Am J Hematol 2017; 92:1204-1213. [PMID: 28815688 DOI: 10.1002/ajh.24888] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 08/08/2017] [Accepted: 08/14/2017] [Indexed: 12/24/2022]
Abstract
Hepcidin is a key iron regulatory hormone that controls expression of the iron exporter ferroportin to increase the iron supply when needed to support erythropoiesis and other essential functions, but to prevent the toxicity of iron excess. The bone morphogenetic protein (BMP)-SMAD signaling pathway, through the ligand BMP6 and the co-receptor hemojuvelin, is a central regulator of hepcidin transcription in the liver in response to iron. Here, we show that dietary iron loading has a residual ability to induce Smad signaling and hepcidin expression in Bmp6-/- mice, effects that are blocked by a neutralizing BMP2/4 antibody. Moreover, BMP2/4 antibody inhibits hepcidin expression and induces iron loading in wildtype mice, whereas a BMP4 antibody has no effect. Bmp2 mRNA is predominantly expressed in endothelial cells of the liver, where its baseline expression is higher, but its induction by iron is less robust than Bmp6. Mice with a conditional ablation of Bmp2 in endothelial cells exhibit hepcidin deficiency, serum iron overload, and tissue iron loading in liver, pancreas and heart, with reduced spleen iron. Together, these data demonstrate that in addition to BMP6, endothelial cell BMP2 has a non-redundant role in hepcidin regulation by iron.
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Affiliation(s)
- Susanna Canali
- Program in Anemia Signaling Research, Division of Nephrology, Program in Membrane Biology, Center for Systems Biology; Massachusetts General Hospital, Harvard Medical School; Boston Massachusetts
| | - Chia-Yu Wang
- Program in Anemia Signaling Research, Division of Nephrology, Program in Membrane Biology, Center for Systems Biology; Massachusetts General Hospital, Harvard Medical School; Boston Massachusetts
| | - Kimberly B. Zumbrennen-Bullough
- Program in Anemia Signaling Research, Division of Nephrology, Program in Membrane Biology, Center for Systems Biology; Massachusetts General Hospital, Harvard Medical School; Boston Massachusetts
| | - Abraham Bayer
- Program in Anemia Signaling Research, Division of Nephrology, Program in Membrane Biology, Center for Systems Biology; Massachusetts General Hospital, Harvard Medical School; Boston Massachusetts
| | - Jodie L. Babitt
- Program in Anemia Signaling Research, Division of Nephrology, Program in Membrane Biology, Center for Systems Biology; Massachusetts General Hospital, Harvard Medical School; Boston Massachusetts
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19
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Breitkopf-Heinlein K, Meyer C, König C, Gaitantzi H, Addante A, Thomas M, Wiercinska E, Cai C, Li Q, Wan F, Hellerbrand C, Valous NA, Hahnel M, Ehlting C, Bode JG, Müller-Bohl S, Klingmüller U, Altenöder J, Ilkavets I, Goumans MJ, Hawinkels LJAC, Lee SJ, Wieland M, Mogler C, Ebert MP, Herrera B, Augustin H, Sánchez A, Dooley S, Ten Dijke P. BMP-9 interferes with liver regeneration and promotes liver fibrosis. Gut 2017; 66:939-954. [PMID: 28336518 DOI: 10.1136/gutjnl-2016-313314] [Citation(s) in RCA: 101] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 02/22/2017] [Accepted: 03/02/2017] [Indexed: 12/12/2022]
Abstract
OBJECTIVE Bone morphogenetic protein (BMP)-9, a member of the transforming growth factor-β family of cytokines, is constitutively produced in the liver. Systemic levels act on many organs and tissues including bone and endothelium, but little is known about its hepatic functions in health and disease. DESIGN Levels of BMP-9 and its receptors were analysed in primary liver cells. Direct effects of BMP-9 on hepatic stellate cells (HSCs) and hepatocytes were studied in vitro, and the role of BMP-9 was examined in acute and chronic liver injury models in mice. RESULTS Quiescent and activated HSCs were identified as major BMP-9 producing liver cell type. BMP-9 stimulation of cultured hepatocytes inhibited proliferation, epithelial to mesenchymal transition and preserved expression of important metabolic enzymes such as cytochrome P450. Acute liver injury caused by partial hepatectomy or single injections of carbon tetrachloride (CCl4) or lipopolysaccharide (LPS) into mice resulted in transient downregulation of hepatic BMP-9 mRNA expression. Correspondingly, LPS stimulation led to downregulation of BMP-9 expression in cultured HSCs. Application of BMP-9 after partial hepatectomy significantly enhanced liver damage and disturbed the proliferative response. Chronic liver damage in BMP-9-deficient mice or in mice adenovirally overexpressing the selective BMP-9 antagonist activin-like kinase 1-Fc resulted in reduced deposition of collagen and subsequent fibrosis. CONCLUSIONS Constitutive expression of low levels of BMP-9 stabilises hepatocyte function in the healthy liver. Upon HSC activation, endogenous BMP-9 levels increase in vitro and in vivo and high levels of BMP-9 cause enhanced damage upon acute or chronic injury.
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Affiliation(s)
| | - Christoph Meyer
- Department of Medicine II, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Courtney König
- Division of Vascular Oncology and Metastasis, German Cancer Research Center Heidelberg (DKFZ-ZMBH Alliance), Heidelberg, Germany
| | - Haristi Gaitantzi
- Department of Medicine II, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Annalisa Addante
- Department of Biochemistry and Molecular Biology II, Faculty of Pharmacy, Complutense University of Madrid, San Carlos Clinical Hospital Health Research Institute (IdISSC), Madrid, Spain
| | - Maria Thomas
- Dr. Margarete Fischer-Bosch Institute of Clinical Pharmacology and University of Tuebingen, Stuttgart, Germany
| | - Eliza Wiercinska
- German Red Cross Blood Service Baden-Württemberg-Hessen and Institute for Transfusion Medicine and Immunohaematology, Goethe University, Frankfurt, Germany
| | - Chen Cai
- Department of Medicine II, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Qi Li
- Department of Medicine II, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.,Department of Gastroenterology and Hepatology, Beijing You'an Hospital, Affiliated with Capital Medical University, Beijing, China
| | - Fengqi Wan
- Department of Medicine II, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Claus Hellerbrand
- Department of Internal Medicine I, University Hospital Regensburg, Regensburg, Germany
| | - Nektarios A Valous
- Applied Tumor Immunity Clinical Cooperation Unit, National Center for Tumor Diseases, German Cancer Research Center, Heidelberg, Germany
| | - Maximilian Hahnel
- University Hospital of the Heinrich-Heine University, Duesseldorf, Germany
| | - Christian Ehlting
- University Hospital of the Heinrich-Heine University, Duesseldorf, Germany
| | - Johannes G Bode
- University Hospital of the Heinrich-Heine University, Duesseldorf, Germany
| | - Stephanie Müller-Bohl
- Division Systems Biology of Signal Transduction, DKFZ-ZMBH Alliance, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Ursula Klingmüller
- Division Systems Biology of Signal Transduction, DKFZ-ZMBH Alliance, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Jutta Altenöder
- Department of Medicine II, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Iryna Ilkavets
- Department of Medicine II, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Marie-José Goumans
- Department of Molecular Cell Biology and Centre for Cancer Genomics, Leiden University Medical Center, Leiden, The Netherlands
| | - Lukas J A C Hawinkels
- Department of Molecular Cell Biology and Centre for Cancer Genomics, Leiden University Medical Center, Leiden, The Netherlands
| | - Se-Jin Lee
- Johns Hopkins University School of Medicine, Molecular Biology and Genetics, Baltimore, USA
| | - Matthias Wieland
- Division of Vascular Oncology and Metastasis, German Cancer Research Center Heidelberg (DKFZ-ZMBH Alliance), Heidelberg, Germany
| | - Carolin Mogler
- Institute of Pathology, Technical University of Munich, München, Germany
| | - Matthias P Ebert
- Department of Medicine II, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Blanca Herrera
- Department of Biochemistry and Molecular Biology II, Faculty of Pharmacy, Complutense University of Madrid, San Carlos Clinical Hospital Health Research Institute (IdISSC), Madrid, Spain
| | - Hellmut Augustin
- Division of Vascular Oncology and Metastasis, German Cancer Research Center Heidelberg (DKFZ-ZMBH Alliance), Heidelberg, Germany.,Department of Vascular Biology and Tumor Angiogenesis (CBTM), Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.,German Cancer Consortium, Heidelberg, Germany
| | - Aránzazu Sánchez
- Department of Biochemistry and Molecular Biology II, Faculty of Pharmacy, Complutense University of Madrid, San Carlos Clinical Hospital Health Research Institute (IdISSC), Madrid, Spain
| | - Steven Dooley
- Department of Medicine II, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Peter Ten Dijke
- Department of Molecular Cell Biology and Centre for Cancer Genomics, Leiden University Medical Center, Leiden, The Netherlands
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20
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Siebold C, Yamashita T, Monnier PP, Mueller BK, Pasterkamp RJ. RGMs: Structural Insights, Molecular Regulation, and Downstream Signaling. Trends Cell Biol 2017; 27:365-378. [PMID: 28007423 PMCID: PMC5404723 DOI: 10.1016/j.tcb.2016.11.009] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2016] [Revised: 11/27/2016] [Accepted: 11/28/2016] [Indexed: 12/20/2022]
Abstract
Although originally discovered as neuronal growth cone-collapsing factors, repulsive guidance molecules (RGMs) are now known as key players in many fundamental processes, such as cell migration, differentiation, iron homeostasis, and apoptosis, during the development and homeostasis of many tissues and organs, including the nervous, skeletal, and immune systems. Furthermore, three RGMs (RGMa, RGMb/DRAGON, and RGMc/hemojuvelin) have been linked to the pathogenesis of various disorders ranging from multiple sclerosis (MS) to cancer and juvenile hemochromatosis (JHH). While the molecular details of these (patho)biological effects and signaling modes have long remained unknown, recent studies unveil several exciting and novel aspects of RGM processing, ligand-receptor interactions, and downstream signaling. In this review, we highlight recent advances in the mechanisms-of-action and function of RGM proteins.
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Affiliation(s)
- Christian Siebold
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Toshihide Yamashita
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, 2-2, Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Philippe P Monnier
- Krembil Research Institute, 60 Leonard Street, M5T 2S8, Toronto, ONT, Canada
| | - Bernhard K Mueller
- Neuroscience Discovery Research, Abbvie, Knollstrasse 50, 67061 Ludwigshafen, Germany
| | - R Jeroen Pasterkamp
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center, Universiteitsweg 100, 3584 CG, Utrecht, The Netherlands.
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Abstract
Iron is required for many biological processes but is also toxic in excess; thus, body iron balance is maintained through sophisticated regulatory mechanisms. The lack of a regulated iron excretory mechanism means that body iron balance is controlled at the level of absorption from the diet. Iron absorption is regulated by the hepatic peptide hormone hepcidin. Hepcidin also controls iron release from cells that recycle or store iron, thus regulating plasma iron concentrations. Hepcidin exerts its effects through its receptor, the cellular iron exporter ferroportin. Important regulators of hepcidin, and therefore of systemic iron homeostasis, include plasma iron concentrations, body iron stores, infection and inflammation, and erythropoiesis. Disturbances in the regulation of hepcidin contribute to the pathogenesis of many iron disorders: hepcidin deficiency causes iron overload in hereditary hemochromatosis and nontransfused β-thalassemia, whereas overproduction of hepcidin is associated with iron-restricted anemias seen in patients with chronic kidney disease, chronic inflammatory diseases, some cancers, and inherited iron-refractory iron deficiency anemia. This review summarizes our current understanding of the molecular mechanisms and signaling pathways involved in the control of hepcidin synthesis in the liver, a principal determinant of plasma hepcidin concentrations.
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Affiliation(s)
- Veena Sangkhae
- Center for Iron Disorders, Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA
| | - Elizabeta Nemeth
- Center for Iron Disorders, Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA
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22
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Endothelial cells produce bone morphogenetic protein 6 required for iron homeostasis in mice. Blood 2016; 129:405-414. [PMID: 27864295 DOI: 10.1182/blood-2016-06-721571] [Citation(s) in RCA: 155] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 11/14/2016] [Indexed: 02/06/2023] Open
Abstract
Bone morphogenetic protein 6 (BMP6) signaling in hepatocytes is a central transcriptional regulator of the iron hormone hepcidin that controls systemic iron balance. How iron levels are sensed to regulate hepcidin production is not known, but local induction of liver BMP6 expression by iron is proposed to have a critical role. To identify the cellular source of BMP6 responsible for hepcidin and iron homeostasis regulation, we generated mice with tissue-specific ablation of Bmp6 in different liver cell populations and evaluated their iron phenotype. Efficiency and specificity of Cre-mediated recombination was assessed by using Cre-reporter mice, polymerase chain reaction of genomic DNA, and quantitation of Bmp6 messenger RNA expression from isolated liver cell populations. Localization of the BMP co-receptor hemojuvelin was visualized by immunofluorescence microscopy. Analysis of the Bmp6 conditional knockout mice revealed that liver endothelial cells (ECs) expressed Bmp6, whereas resident liver macrophages (Kupffer cells) and hepatocytes did not. Loss of Bmp6 in ECs recapitulated the hemochromatosis phenotype of global Bmp6 knockout mice, whereas hepatocyte and macrophage Bmp6 conditional knockout mice exhibited no iron phenotype. Hemojuvelin was localized on the hepatocyte sinusoidal membrane immediately adjacent to Bmp6-producing sinusoidal ECs. Together, these data demonstrate that ECs are the predominant source of BMP6 in the liver and support a model in which EC BMP6 has paracrine actions on hepatocyte hemojuvelin to regulate hepcidin transcription and maintain systemic iron homeostasis.
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Li N, Qiao M, Zhao Q, Zhang P, Song L, Li L, Cui C. Effects of maternal lead exposure on RGMa and RGMb expression in the hippocampus and cerebral cortex of mouse pups. Brain Res Bull 2016; 127:38-46. [DOI: 10.1016/j.brainresbull.2016.08.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2016] [Revised: 08/16/2016] [Accepted: 08/18/2016] [Indexed: 11/26/2022]
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Zhang H, Ma S, Feng Z, Wang D, Li C, Cao Y, Chen X, Liu A, Zhu Z, Zhang J, Zhang G, Chai Y, Wang L, Xie XQ. Cardiovascular Disease Chemogenomics Knowledgebase-guided Target Identification and Drug Synergy Mechanism Study of an Herbal Formula. Sci Rep 2016; 6:33963. [PMID: 27678063 PMCID: PMC5039409 DOI: 10.1038/srep33963] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 08/25/2016] [Indexed: 12/14/2022] Open
Abstract
Combination therapy is a popular treatment for various diseases in the clinic. Among the successful cases, Traditional Chinese Medicinal (TCM) formulae can achieve synergistic effects in therapeutics and antagonistic effects in toxicity. However, characterizing the underlying molecular synergisms for the combination of drugs remains a challenging task due to high experimental expenses and complication of multicomponent herbal medicines. To understand the rationale of combination therapy, we investigated Sini Decoction, a well-known TCM consisting of three herbs, as a model. We applied our established diseases-specific chemogenomics databases and our systems pharmacology approach TargetHunter to explore synergistic mechanisms of Sini Decoction in the treatment of cardiovascular diseases. (1) We constructed a cardiovascular diseases-specific chemogenomics database, including drugs, target proteins, chemicals, and associated pathways. (2) Using our implemented chemoinformatics tools, we mapped out the interaction networks between active ingredients of Sini Decoction and their targets. (3) We also in silico predicted and experimentally confirmed that the side effects can be alleviated by the combination of the components. Overall, our results demonstrated that our cardiovascular disease-specific database was successfully applied for systems pharmacology analysis of a complicated herbal formula in predicting molecular synergetic mechanisms, and led to better understanding of a combinational therapy.
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Affiliation(s)
- Hai Zhang
- College of pharmacy, Second Military Medical University; Department of Pharmacy, Third Affiliated Hospital of Second Military Medical University, Shanghai 200433, China
| | - Shifan Ma
- Department of Pharmaceutical Sciences and Computational Chemical Genomics Screening Center, School of Pharmacy; National Center of Excellence for Computational Drug Abuse Research; Drug Discovery Institute; Departments of Computational Biology and Structural Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Zhiwei Feng
- Department of Pharmaceutical Sciences and Computational Chemical Genomics Screening Center, School of Pharmacy; National Center of Excellence for Computational Drug Abuse Research; Drug Discovery Institute; Departments of Computational Biology and Structural Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Dongyao Wang
- College of pharmacy, Second Military Medical University; Department of Pharmacy, Third Affiliated Hospital of Second Military Medical University, Shanghai 200433, China
| | - Chengjian Li
- College of pharmacy, Second Military Medical University; Department of Pharmacy, Third Affiliated Hospital of Second Military Medical University, Shanghai 200433, China
| | - Yan Cao
- College of pharmacy, Second Military Medical University; Department of Pharmacy, Third Affiliated Hospital of Second Military Medical University, Shanghai 200433, China
| | - Xiaofei Chen
- College of pharmacy, Second Military Medical University; Department of Pharmacy, Third Affiliated Hospital of Second Military Medical University, Shanghai 200433, China
| | - Aijun Liu
- College of pharmacy, Second Military Medical University; Department of Pharmacy, Third Affiliated Hospital of Second Military Medical University, Shanghai 200433, China
| | - Zhenyu Zhu
- College of pharmacy, Second Military Medical University; Department of Pharmacy, Third Affiliated Hospital of Second Military Medical University, Shanghai 200433, China
| | - Junping Zhang
- College of pharmacy, Second Military Medical University; Department of Pharmacy, Third Affiliated Hospital of Second Military Medical University, Shanghai 200433, China
| | - Guoqing Zhang
- College of pharmacy, Second Military Medical University; Department of Pharmacy, Third Affiliated Hospital of Second Military Medical University, Shanghai 200433, China
| | - Yifeng Chai
- College of pharmacy, Second Military Medical University; Department of Pharmacy, Third Affiliated Hospital of Second Military Medical University, Shanghai 200433, China
| | - Lirong Wang
- Department of Pharmaceutical Sciences and Computational Chemical Genomics Screening Center, School of Pharmacy; National Center of Excellence for Computational Drug Abuse Research; Drug Discovery Institute; Departments of Computational Biology and Structural Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Xiang-Qun Xie
- Department of Pharmaceutical Sciences and Computational Chemical Genomics Screening Center, School of Pharmacy; National Center of Excellence for Computational Drug Abuse Research; Drug Discovery Institute; Departments of Computational Biology and Structural Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
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Ehnert S, Aspera-Werz RH, Freude T, Reumann MK, Ochs BG, Bahrs C, Schröter S, Wintermeyer E, Nussler AK, Pscherer S. Distinct Gene Expression Patterns Defining Human Osteoblasts' Response to BMP2 Treatment: Is the Therapeutic Success All a Matter of Timing? Eur Surg Res 2016; 57:197-210. [DOI: 10.1159/000447089] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 05/25/2016] [Indexed: 11/19/2022]
Abstract
Background: Bone morphogenetic proteins (BMPs) play a key role in bone formation. Local application of BMP2 (Dibotermin alfa) supports bone formation when applied to complex fractures. However, up to 33% of patients do not respond to this therapy. Purpose: Aiming to investigate whether inter-individual responses to BMP2 treatment can be predicted by gene expression patterns, we investigated the effect of BMP2 on primary human osteoblasts and THP-1 cell-derived osteoclasts from 110 donors. Methods: Osteoblasts were obtained by collagenase digestion of spongy bone tissues. Osteoclasts were differentiated from THP-1 cells using the conditioned media of the osteoblasts. Viability was determined by resazurin conversion. As functional characteristics AP and Trap5B activity were measured. Gene expression levels were determined by RT-PCR in 21 of the 110 evaluated donors and visualized by electrophoresis. Results: Based on our data, we could classify three response groups: (i) In 51.8% of all donors, BMP2 treatment induced osteoblast function. These donors strongly expressed the BMP2 inhibitor Noggin (NOG), the alternative BMP2 receptors repulsive guidance molecule B (RGMb) and activin receptor-like kinase 6 (Alk6), as well as the Wnt inhibitor sclerostin (SOST). (ii) In 17.3% of all donors, BMP2 treatment induced viability. In these donors, the initial high SOST expression significantly dropped with BMP2 treatment. (iii) 30.9% of all donors were not directly affected by BMP2 treatment. These donors expressed high levels of the pseudoreceptor BMP and activin membrane-bound inhibitor (BAMBI) and lacked SOST expression. In all donors, SOST expression correlated directly with receptor activator of NF-κB ligand (RANKL) expression, defining the cells' potential to stimulate osteoclastogenesis. Conclusions: Our data identified three donor groups profiting from BMP2 treatment either directly via stimulation of osteoblast function or viability and/or indirectly via inhibition of osteoclastogenesis, depending on their expression of BAMBI, SOST, NOG, and RANKL. On the basis of patients' respective expression profiles, the clinical application of BMP2 as well as its timing might be modified in order to better fit the patients' needs to promote bone formation or to inhibit bone resorption.
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26
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Canali S, Core AB, Zumbrennen-Bullough KB, Merkulova M, Wang CY, Schneyer AL, Pietrangelo A, Babitt JL. Activin B Induces Noncanonical SMAD1/5/8 Signaling via BMP Type I Receptors in Hepatocytes: Evidence for a Role in Hepcidin Induction by Inflammation in Male Mice. Endocrinology 2016; 157:1146-62. [PMID: 26735394 PMCID: PMC4769363 DOI: 10.1210/en.2015-1747] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Induction of the iron regulatory hormone hepcidin contributes to the anemia of inflammation. Bone morphogenetic protein 6 (BMP6) signaling is a central regulator of hepcidin expression in the liver. Recently, the TGF-β/BMP superfamily member activin B was implicated in hepcidin induction by inflammation via noncanonical SMAD1/5/8 signaling, but its mechanism of action and functional significance in vivo remain uncertain. Here, we show that low concentrations of activin B, but not activin A, stimulate prolonged SMAD1/5/8 signaling and hepcidin expression in liver cells to a similar degree as canonical SMAD2/3 signaling, and with similar or modestly reduced potency compared with BMP6. Activin B stimulates hepcidin via classical activin type II receptors ACVR2A and ACVR2B, noncanonical BMP type I receptors activin receptor-like kinase 2 and activin receptor-like kinase 3, and SMAD5. The coreceptor hemojuvelin binds to activin B and facilitates activin B-SMAD1/5/8 signaling. Activin B-SMAD1/5/8 signaling has some selectivity for hepatocyte-derived cells and is not enabled by hemojuvelin in other cell types. Liver activin B mRNA expression is up-regulated in multiple mouse models of inflammation associated with increased hepcidin and hypoferremia, including lipopolysaccharide, turpentine, and heat-killed Brucella abortus models. Finally, the activin inhibitor follistatin-315 blunts hepcidin induction by lipopolysaccharide or B. abortus in mice. Our data elucidate a novel mechanism for noncanonical SMAD activation and support a likely functional role for activin B in hepcidin stimulation during inflammation in vivo.
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Affiliation(s)
- Susanna Canali
- Program in Anemia Signaling Research (S.C., A.B.C., K.B.Z.-B., M.M., C.-Y.W., J.L.B.), Division of Nephrology, Program in Membrane Biology, Center for Systems Biology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114; Center for Hemochromatosis (S.C., A.P.), University Hospital of Modena and Reggio Emilia, Modena Italy 41124; and Department of Veterinary and Animal Science (A.S.), University of Massachusetts Amherst, Amherst, Massachusetts 01003
| | - Amanda B Core
- Program in Anemia Signaling Research (S.C., A.B.C., K.B.Z.-B., M.M., C.-Y.W., J.L.B.), Division of Nephrology, Program in Membrane Biology, Center for Systems Biology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114; Center for Hemochromatosis (S.C., A.P.), University Hospital of Modena and Reggio Emilia, Modena Italy 41124; and Department of Veterinary and Animal Science (A.S.), University of Massachusetts Amherst, Amherst, Massachusetts 01003
| | - Kimberly B Zumbrennen-Bullough
- Program in Anemia Signaling Research (S.C., A.B.C., K.B.Z.-B., M.M., C.-Y.W., J.L.B.), Division of Nephrology, Program in Membrane Biology, Center for Systems Biology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114; Center for Hemochromatosis (S.C., A.P.), University Hospital of Modena and Reggio Emilia, Modena Italy 41124; and Department of Veterinary and Animal Science (A.S.), University of Massachusetts Amherst, Amherst, Massachusetts 01003
| | - Maria Merkulova
- Program in Anemia Signaling Research (S.C., A.B.C., K.B.Z.-B., M.M., C.-Y.W., J.L.B.), Division of Nephrology, Program in Membrane Biology, Center for Systems Biology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114; Center for Hemochromatosis (S.C., A.P.), University Hospital of Modena and Reggio Emilia, Modena Italy 41124; and Department of Veterinary and Animal Science (A.S.), University of Massachusetts Amherst, Amherst, Massachusetts 01003
| | - Chia-Yu Wang
- Program in Anemia Signaling Research (S.C., A.B.C., K.B.Z.-B., M.M., C.-Y.W., J.L.B.), Division of Nephrology, Program in Membrane Biology, Center for Systems Biology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114; Center for Hemochromatosis (S.C., A.P.), University Hospital of Modena and Reggio Emilia, Modena Italy 41124; and Department of Veterinary and Animal Science (A.S.), University of Massachusetts Amherst, Amherst, Massachusetts 01003
| | - Alan L Schneyer
- Program in Anemia Signaling Research (S.C., A.B.C., K.B.Z.-B., M.M., C.-Y.W., J.L.B.), Division of Nephrology, Program in Membrane Biology, Center for Systems Biology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114; Center for Hemochromatosis (S.C., A.P.), University Hospital of Modena and Reggio Emilia, Modena Italy 41124; and Department of Veterinary and Animal Science (A.S.), University of Massachusetts Amherst, Amherst, Massachusetts 01003
| | - Antonello Pietrangelo
- Program in Anemia Signaling Research (S.C., A.B.C., K.B.Z.-B., M.M., C.-Y.W., J.L.B.), Division of Nephrology, Program in Membrane Biology, Center for Systems Biology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114; Center for Hemochromatosis (S.C., A.P.), University Hospital of Modena and Reggio Emilia, Modena Italy 41124; and Department of Veterinary and Animal Science (A.S.), University of Massachusetts Amherst, Amherst, Massachusetts 01003
| | - Jodie L Babitt
- Program in Anemia Signaling Research (S.C., A.B.C., K.B.Z.-B., M.M., C.-Y.W., J.L.B.), Division of Nephrology, Program in Membrane Biology, Center for Systems Biology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114; Center for Hemochromatosis (S.C., A.P.), University Hospital of Modena and Reggio Emilia, Modena Italy 41124; and Department of Veterinary and Animal Science (A.S.), University of Massachusetts Amherst, Amherst, Massachusetts 01003
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Shabareesh PRV, Kaur KJ. Structural and Functional Characterization of Hirudin P6 Derived Novel Bivalent Thrombin Inhibitors - Studying the Effect of Linker Length and Glycosylation on Their Function. Chem Biol Drug Des 2016; 88:129-41. [DOI: 10.1111/cbdd.12742] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Revised: 01/06/2016] [Accepted: 01/30/2016] [Indexed: 12/23/2022]
Affiliation(s)
- PRV Shabareesh
- National Institute of Immunology; Aruna Asaf Ali Marg New Delhi 110067 India
| | - Kanwal J. Kaur
- National Institute of Immunology; Aruna Asaf Ali Marg New Delhi 110067 India
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28
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Latour C, Besson-Fournier C, Meynard D, Silvestri L, Gourbeyre O, Aguilar-Martinez P, Schmidt PJ, Fleming MD, Roth MP, Coppin H. Differing impact of the deletion of hemochromatosis-associated molecules HFE and transferrin receptor-2 on the iron phenotype of mice lacking bone morphogenetic protein 6 or hemojuvelin. Hepatology 2016; 63:126-37. [PMID: 26406355 DOI: 10.1002/hep.28254] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 09/22/2015] [Indexed: 12/07/2022]
Abstract
UNLABELLED Hereditary hemochromatosis, which is characterized by inappropriately low levels of hepcidin, increased dietary iron uptake, and systemic iron accumulation, has been associated with mutations in the HFE, transferrin receptor-2 (TfR2), and hemojuvelin (HJV) genes. However, it is still not clear whether these molecules intersect in vivo with bone morphogenetic protein 6 (BMP6)/mothers against decapentaplegic (SMAD) homolog signaling, the main pathway up-regulating hepcidin expression in response to elevated hepatic iron. To answer this question, we produced double knockout mice for Bmp6 and β2-microglobulin (a surrogate for the loss of Hfe) and for Bmp6 and Tfr2, and we compared their phenotype (hepcidin expression, Bmp/Smad signaling, hepatic and extrahepatic tissue iron accumulation) with that of single Bmp6-deficient mice and that of mice deficient for Hjv, alone or in combination with Hfe or Tfr2. Whereas the phenotype of Hjv-deficient females was not affected by loss of Hfe or Tfr2, that of Bmp6-deficient females was considerably worsened, with decreased Smad5 phosphorylation, compared with single Bmp6-deficient mice, further repression of hepcidin gene expression, undetectable serum hepcidin, and massive iron accumulation not only in the liver but also in the pancreas, the heart, and the kidneys. CONCLUSION These results show that (1) BMP6 does not require HJV to transduce signal to hepcidin in response to intracellular iron, even if the loss of HJV partly reduces this signal, (2) another BMP ligand can replace BMP6 and significantly induce hepcidin expression in response to extracellular iron, and (3) BMP6 alone is as efficient at inducing hepcidin as the other BMPs in association with the HJV/HFE/TfR2 complex; they provide an explanation for the compensatory effect of BMP6 treatment on the molecular defect underlying Hfe hemochromatosis in mice.
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Affiliation(s)
- Chloé Latour
- Centre de Physiopathologie de Toulouse Purpan, Inserm U1043, CNRS U5282, Université de Toulouse III, Toulouse, France
| | - Céline Besson-Fournier
- Centre de Physiopathologie de Toulouse Purpan, Inserm U1043, CNRS U5282, Université de Toulouse III, Toulouse, France
| | - Delphine Meynard
- Centre de Physiopathologie de Toulouse Purpan, Inserm U1043, CNRS U5282, Université de Toulouse III, Toulouse, France
| | - Laura Silvestri
- San Raffaele Scientific Institute & Vita-Salute University, Milan, Italy
| | - Ophélie Gourbeyre
- Centre de Physiopathologie de Toulouse Purpan, Inserm U1043, CNRS U5282, Université de Toulouse III, Toulouse, France
| | - Patricia Aguilar-Martinez
- Centre de Physiopathologie de Toulouse Purpan, Inserm U1043, CNRS U5282, Université de Toulouse III, Toulouse, France.,Laboratory of Haematology, CHRU de Montpellier, Hôpital Saint Eloi, Montpellier, France
| | - Paul J Schmidt
- Department of Pathology, Boston Children's Hospital and Harvard Medical School, Boston, MA
| | - Mark D Fleming
- Department of Pathology, Boston Children's Hospital and Harvard Medical School, Boston, MA
| | - Marie-Paule Roth
- Centre de Physiopathologie de Toulouse Purpan, Inserm U1043, CNRS U5282, Université de Toulouse III, Toulouse, France
| | - Hélène Coppin
- Centre de Physiopathologie de Toulouse Purpan, Inserm U1043, CNRS U5282, Université de Toulouse III, Toulouse, France
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29
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Martins AF, Xavier Neto J, Azambuja A, Sereno ML, Figueira A, Campos-Junior PH, Rosário MF, Toledo CBB, Silva GAB, Kitten GT, Coutinho LL, Dietrich S, Jorge EC. Repulsive Guidance Molecules a, b and c Are Skeletal Muscle Proteins, and Repulsive Guidance Molecule a Promotes Cellular Hypertrophy and Is Necessary for Myotube Fusion. Cells Tissues Organs 2015; 200:326-38. [PMID: 26397945 DOI: 10.1159/000433491] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/21/2015] [Indexed: 11/19/2022] Open
Abstract
Repulsive guidance molecules (RGMs) compose a family of glycosylphosphatidylinositol (GPI)-anchored axon guidance molecules and perform several functions during neural development. New evidence has suggested possible new roles for these axon guidance molecules during skeletal muscle development, which has not been investigated thus far. In the present study, we show that RGMa, RGMb and RGMc are all induced during skeletal muscle differentiation in vitro. Immunolocalization performed on adult skeletal muscle cells revealed that RGMa, RGMb and RGMc are sarcolemmal proteins. Additionally, RGMa was found to be a sarcoplasmic protein with a surprisingly striated pattern. RGMa colocalization with known sarcoplasmic proteins suggested that this axon guidance molecule is a skeletal muscle sarcoplasmic protein. Western blot analysis revealed two RGMa fragments of 60 and 33 kDa, respectively, in adult skeletal muscle samples. RGMa phenotypes in skeletal muscle cells (C2C12 and primary myoblasts) were also investigated. RGMa overexpression produced hypertrophic cells, whereas RGMa knockdown resulted in the opposite phenotype. RGMa knockdown also blocked myotube formation in both skeletal muscle cell types. Our results are the first to show an axon guidance molecule as a skeletal muscle sarcoplasmic protein and to include RGMa in a system that regulates skeletal muscle cell size and differentiation.
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Affiliation(s)
- Aline Fagundes Martins
- Departamento de Morfologia, Instituto de Cix00EA;ncias Biolx00F3;gicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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Healey EG, Bishop B, Elegheert J, Bell CH, Padilla-Parra S, Siebold C. Repulsive guidance molecule is a structural bridge between neogenin and bone morphogenetic protein. Nat Struct Mol Biol 2015; 22:458-65. [PMID: 25938661 PMCID: PMC4456160 DOI: 10.1038/nsmb.3016] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 03/31/2015] [Indexed: 02/07/2023]
Abstract
Repulsive guidance molecules (RGMs) control crucial processes including cell motility, adhesion, immune-cell regulation and systemic iron metabolism. RGMs signal via the neogenin (NEO1) and the bone morphogenetic protein (BMP) pathways. Here, we report crystal structures of the N-terminal domains of all human RGM family members in complex with the BMP ligand BMP2, revealing a new protein fold and a conserved BMP-binding mode. Our structural and functional data suggest a pH-linked mechanism for RGM-activated BMP signaling and offer a rationale for RGM mutations causing juvenile hemochromatosis. We also determined the crystal structure of the ternary BMP2-RGM-NEO1 complex, which, along with solution scattering and live-cell super-resolution fluorescence microscopy, indicates BMP-induced clustering of the RGM-NEO1 complex. Our results show how RGM acts as the central hub that links BMP and NEO1 and physically connects these fundamental signaling pathways.
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Affiliation(s)
- Eleanor G Healey
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Benjamin Bishop
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Jonathan Elegheert
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Christian H Bell
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Sergi Padilla-Parra
- 1] Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK. [2] Cellular Imaging Core, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Christian Siebold
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
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Dowell KG, Simons AK, Bai H, Kell B, Wang ZZ, Yun K, Hibbs MA. Novel insights into embryonic stem cell self-renewal revealed through comparative human and mouse systems biology networks. Stem Cells 2014; 32:1161-72. [PMID: 24307629 DOI: 10.1002/stem.1612] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Accepted: 10/11/2013] [Indexed: 12/25/2022]
Abstract
Embryonic stem cells (ESCs), characterized by their ability to both self-renew and differentiate into multiple cell lineages, are a powerful model for biomedical research and developmental biology. Human and mouse ESCs share many features, yet have distinctive aspects, including fundamental differences in the signaling pathways and cell cycle controls that support self-renewal. Here, we explore the molecular basis of human ESC self-renewal using Bayesian network machine learning to integrate cell-type-specific, high-throughput data for gene function discovery. We integrated high-throughput ESC data from 83 human studies (~1.8 million data points collected under 1,100 conditions) and 62 mouse studies (~2.4 million data points collected under 1,085 conditions) into separate human and mouse predictive networks focused on ESC self-renewal to analyze shared and distinct functional relationships among protein-coding gene orthologs. Computational evaluations show that these networks are highly accurate, literature validation confirms their biological relevance, and reverse transcriptase polymerase chain reaction (RT-PCR) validation supports our predictions. Our results reflect the importance of key regulatory genes known to be strongly associated with self-renewal and pluripotency in both species (e.g., POU5F1, SOX2, and NANOG), identify metabolic differences between species (e.g., threonine metabolism), clarify differences between human and mouse ESC developmental signaling pathways (e.g., leukemia inhibitory factor (LIF)-activated JAK/STAT in mouse; NODAL/ACTIVIN-A-activated fibroblast growth factor in human), and reveal many novel genes and pathways predicted to be functionally associated with self-renewal in each species. These interactive networks are available online at www.StemSight.org for stem cell researchers to develop new hypotheses, discover potential mechanisms involving sparsely annotated genes, and prioritize genes of interest for experimental validation.
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Affiliation(s)
- Karen G Dowell
- The Jackson Laboratory, Bar Harbor, Maine, USA; Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, Maine, USA
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Pauk M, Grgurevic L, Brkljacic J, Kufner V, Bordukalo-Niksic T, Grabusic K, Razdorov G, Rogic D, Zuvic M, Oppermann H, Babitt JL, Lin HY, Volarevic S, Vukicevic S. Exogenous BMP7 corrects plasma iron overload and bone loss in Bmp6-/- mice. INTERNATIONAL ORTHOPAEDICS 2014; 39:161-72. [PMID: 25300398 DOI: 10.1007/s00264-014-2550-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 09/22/2014] [Indexed: 02/07/2023]
Abstract
PURPOSE Iron overload accelerates bone loss in mice lacking the bone morphogenetic protein 6 (Bmp6) gene, which is the key endogenous regulator of hepcidin, iron homeostasis gene. We investigated involvement of other BMPs in preventing haemochromatosis and subsequent osteopenia in Bmp6-/- mice. METHODS Iron-treated wild-type (WT) and Bmp6-/- mice were analysed for hepcidin messenger RNA (mRNA) and tissue and blood BMP levels by quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR), immunohistochemistry, Western blot, enzyme-linked immunosorbent assay (ELISA) and proximity extension assay. BMPs labeled with technetium-99m were used in pharmacokinetic studies. RESULTS In WT mice, 4 h following iron challenge, liver Bmp6 and hepcidin expression were increased, while expression of other Bmps was not affected. In parallel, we provided the first evidence that BMP6 circulates in WT mice and that iron increased the BMP6 serum level and the specific liver uptake of (99m)Tc-BMP6. In Bmp6-/- mice, iron challenge led to blunted activation of liver Smad signaling and hepcidin expression with a delay of 24 h, associated with increased Bmp5 and Bmp7 expression and increased Bmp2, 4, 5 and 9 expression in the duodenum. Liver Bmp7 expression and increased circulating BMP9 eventually contributed to the late hepcidin response. This was further supported by exogenous BMP7 therapy resulting in an effective hepcidin expression followed by a rapid normalisation of plasma iron values and restored osteopenia in Bmp6-/- mice. CONCLUSION In Bmp6-/- mice, iron activated endogenous compensatory mechanisms of other BMPs that were not sufficient for preventing hemochromatosis and bone loss. Administration of exogenous BMP7 was effective in correcting the plasma iron level and bone loss, indicating that BMP6 is an essential but not exclusive in vivo regulator of iron homeostasis.
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Affiliation(s)
- Martina Pauk
- Center for Translational and Clinical Research, University of Zagreb School of Medicine, Salata 11, 10000, Zagreb, Croatia,
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BMP type II receptors have redundant roles in the regulation of hepatic hepcidin gene expression and iron metabolism. Blood 2014; 124:2116-23. [PMID: 25075125 DOI: 10.1182/blood-2014-04-572644] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Expression of hepcidin, the hepatic hormone controlling iron homeostasis, is regulated by bone morphogenetic protein (BMP) signaling. We sought to identify which BMP type II receptor expressed in hepatocytes, ActR2a or BMPR2, is responsible for regulating hepcidin gene expression. We studied Bmpr2 heterozygous mice (Bmpr2(+/-)), mice with hepatocyte-specific deficiency of BMPR2, mice with global deficiency of ActR2a, and mice in which hepatocytes lacked both BMPR2 and ActR2a. Hepatic hepcidin messenger RNA (mRNA) levels, serum hepcidin and iron levels, and tissue iron levels did not differ in wild-type mice, Bmpr2(+/-) mice, and mice in which either BMPR2 or ActR2a was deficient. Deficiency of both BMP type II receptors markedly reduced hepatic hepcidin gene expression and serum hepcidin levels leading to severe iron overload. Iron injection increased hepatic hepcidin mRNA levels in mice deficient in either BMPR2 or ActR2a, but not in mice deficient in both BMP type II receptors. In addition, in mouse and human primary hepatocytes, deficiency of both BMPR2 and ActR2a profoundly decreased basal and BMP6-induced hepcidin gene expression. These results suggest that BMP type II receptors, BMPR2 and ActR2a, have redundant roles in the regulation of hepatic hepcidin gene expression and iron metabolism.
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Abstract
Hepcidin, the liver-produced peptide hormone, is a principal regulator of iron homeostasis. Abnormal hepcidin production has emerged as a causative factor in several common iron disorders. Hepcidin insufficiency results in iron overload in hereditary hemochromatosis and iron-loading anemias, whereas hepcidin excess causes or contributes to the development of iron-restricted anemias in inflammatory diseases, infections, some cancers and chronic kidney disease. Not surprisingly, hepcidin and related pathways have become the target for the development of novel therapeutics for iron disorders. In this review, we will summarize the strategies and development programs that have been devised for agonizing or antagonizing hepcidin and its receptor ferroportin.
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Core AB, Canali S, Babitt JL. Hemojuvelin and bone morphogenetic protein (BMP) signaling in iron homeostasis. Front Pharmacol 2014; 5:104. [PMID: 24860505 PMCID: PMC4026703 DOI: 10.3389/fphar.2014.00104] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 04/21/2014] [Indexed: 12/13/2022] Open
Abstract
Mutations in hemojuvelin (HJV) are the most common cause of the juvenile-onset form of the iron overload disorder hereditary hemochromatosis. The discovery that HJV functions as a co-receptor for the bone morphogenetic protein (BMP) family of signaling molecules helped to identify this signaling pathway as a central regulator of the key iron hormone hepcidin in the control of systemic iron homeostasis. This review highlights recent work uncovering the mechanism of action of HJV and the BMP-SMAD signaling pathway in regulating hepcidin expression in the liver, as well as additional studies investigating possible extra-hepatic functions of HJV. This review also explores the interaction between HJV, the BMP-SMAD signaling pathway and other regulators of hepcidin expression in systemic iron balance.
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Affiliation(s)
- Amanda B Core
- Division of Nephrology, Program in Membrane Biology, Center for Systems Biology, Massachusetts General Hospital, Harvard Medical School, Program in Anemia Signaling Research Boston, MA, USA
| | - Susanna Canali
- Division of Nephrology, Program in Membrane Biology, Center for Systems Biology, Massachusetts General Hospital, Harvard Medical School, Program in Anemia Signaling Research Boston, MA, USA
| | - Jodie L Babitt
- Division of Nephrology, Program in Membrane Biology, Center for Systems Biology, Massachusetts General Hospital, Harvard Medical School, Program in Anemia Signaling Research Boston, MA, USA
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Xiao Y, Yu S, Zhu B, Bedoret D, Bu X, Francisco LM, Hua P, Duke-Cohan JS, Umetsu DT, Sharpe AH, DeKruyff RH, Freeman GJ. RGMb is a novel binding partner for PD-L2 and its engagement with PD-L2 promotes respiratory tolerance. ACTA ACUST UNITED AC 2014; 211:943-59. [PMID: 24752301 PMCID: PMC4010901 DOI: 10.1084/jem.20130790] [Citation(s) in RCA: 243] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Interaction between the inhibitory molecule PD-L2 on dendritic cells and repulsive guidance molecule b (RGMb) on lung macrophages is required to establish respiratory tolerance. We report that programmed death ligand 2 (PD-L2), a known ligand of PD-1, also binds to repulsive guidance molecule b (RGMb), which was originally identified in the nervous system as a co-receptor for bone morphogenetic proteins (BMPs). PD-L2 and BMP-2/4 bind to distinct sites on RGMb. Normal resting lung interstitial macrophages and alveolar epithelial cells express high levels of RGMb mRNA, whereas lung dendritic cells express PD-L2. Blockade of the RGMb–PD-L2 interaction markedly impaired the development of respiratory tolerance by interfering with the initial T cell expansion required for respiratory tolerance. Experiments with PD-L2–deficient mice showed that PD-L2 expression on non–T cells was critical for respiratory tolerance, but expression on T cells was not required. Because PD-L2 binds to both PD-1, which inhibits antitumor immunity, and to RGMb, which regulates respiratory immunity, targeting the PD-L2 pathway has therapeutic potential for asthma, cancer, and other immune-mediated disorders. Understanding this pathway may provide insights into how to optimally modulate the PD-1 pathway in cancer immunotherapy while minimizing adverse events.
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Affiliation(s)
- Yanping Xiao
- Department of Medical Oncology, Dana-Farber Cancer Institute; 2 Division of Immunology and Department of Pediatrics, Boston Children's Hospital; 3 Department of Microbiology and Immunobiology and 4 Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115
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Xiao Y, Yu S, Zhu B, Bedoret D, Bu X, Francisco LM, Hua P, Duke-Cohan JS, Umetsu DT, Sharpe AH, DeKruyff RH, Freeman GJ. RGMb is a novel binding partner for PD-L2 and its engagement with PD-L2 promotes respiratory tolerance. Mol Immunol 2014; 48:1292-300. [PMID: 24752301 DOI: 10.1016/j.molimm.2010.12.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2010] [Revised: 11/17/2010] [Accepted: 12/08/2010] [Indexed: 12/30/2022]
Abstract
We report that programmed death ligand 2 (PD-L2), a known ligand of PD-1, also binds to repulsive guidance molecule b (RGMb), which was originally identified in the nervous system as a co-receptor for bone morphogenetic proteins (BMPs). PD-L2 and BMP-2/4 bind to distinct sites on RGMb. Normal resting lung interstitial macrophages and alveolar epithelial cells express high levels of RGMb mRNA, whereas lung dendritic cells express PD-L2. Blockade of the RGMb-PD-L2 interaction markedly impaired the development of respiratory tolerance by interfering with the initial T cell expansion required for respiratory tolerance. Experiments with PD-L2-deficient mice showed that PD-L2 expression on non-T cells was critical for respiratory tolerance, but expression on T cells was not required. Because PD-L2 binds to both PD-1, which inhibits antitumor immunity, and to RGMb, which regulates respiratory immunity, targeting the PD-L2 pathway has therapeutic potential for asthma, cancer, and other immune-mediated disorders. Understanding this pathway may provide insights into how to optimally modulate the PD-1 pathway in cancer immunotherapy while minimizing adverse events.
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Affiliation(s)
- Yanping Xiao
- Department of Medical Oncology, Dana-Farber Cancer Institute; 2 Division of Immunology and Department of Pediatrics, Boston Children's Hospital; 3 Department of Microbiology and Immunobiology and 4 Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115
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Potential roles of bone morphogenetic protein (BMP)-9 in human liver diseases. Int J Mol Sci 2014; 15:5199-220. [PMID: 24670474 PMCID: PMC4013558 DOI: 10.3390/ijms15045199] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Revised: 03/07/2014] [Accepted: 03/17/2014] [Indexed: 01/01/2023] Open
Abstract
Bone morphogenetic proteins (BMP-2 to BMP-15) belong to the Transforming Growth Factor (TGF)-β superfamily and, besides their well-documented roles during embryogenesis and bone formation, some of them have recently been described to be involved in the pathogenesis of different organs, including the liver. The role of BMPs in liver damage responses including hepatocellular carcinoma (HCC) development has only begun to be addressed and strong evidence supports the concept of a pro-tumorigenic role of BMP signaling in HCC cells. BMP-9 (also termed Growth and Differentiation Factor (GDF)-2) represents the most recently discovered member of the BMP family. We have previously demonstrated that in HCC patient samples BMP-9 expression was positively associated with the tumor seize (“T stage”) and that it enhanced cell migration and induced epithelial to mesenchymal transition (EMT) in HCC cells in vitro. In another study we recently found that BMP-9 promotes growth in HCC cells, but not in non-transformed hepatocytes. Published as well as unpublished results obtained with primary hepatocytes support the concept of a dual function of BMP-9 in the liver: while in primary, non-malignant cells BMP-9 stabilizes the epithelial phenotype and inhibits proliferation, in HCC cells it induces cell growth and the acquisition of a migratory phenotype. In this review article we summarize current knowledge about BMPs in liver diseases, with special focus on the role of BMP-9 in HCC development and progression, that may provide new clues for a better understanding of the contribution of BMP-signaling to chronic liver diseases.
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Kwon SJ, Lee GT, Lee JH, Iwakura Y, Kim WJ, Kim IY. Mechanism of pro-tumorigenic effect of BMP-6: neovascularization involving tumor-associated macrophages and IL-1a. Prostate 2014; 74:121-33. [PMID: 24185914 DOI: 10.1002/pros.22734] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Accepted: 09/05/2013] [Indexed: 12/13/2022]
Abstract
INTRODUCTION. Overexpression of bone morphogenetic protein-6 (BMP-6) has been reported in human prostate cancer tissues. Previously we have demonstrated that BMP-6 enhances prostate cancer growth in mice and not in tissue culture. Herein, we have investigated the mechanism of BMP-6’s pro-tumorigenic effect in prostate cancer. METHODS. Tramp C2 murine and LNCaP human prostate cancer cell lines were co-cultured with RAW 264.7 and THP-1 cells, respectively. IL-1a knockout mice were used to confirm the role of BMP-6/IL-1a loop in vivo. Lastly, conditional macrophage null mice cd11b-DTR was used. RESULTS. The results demonstrated that BMP-6 induced the expression of IL-1a in macrophages via a cross-talk between NF-kB1 p50 and Smad1. When endothelial cells were treated with conditioned media harvested from macrophages incubated with BMP-6, tube formation was detected. In the presence of IL-1a neutralizing antibody, endothelial tube formation was blocked. In vivo, tumor growth and neovascularization decreased significantly when BMP-6 was expressed in IL-1a knockout and conditional macrophage-null mice. CONCLUSIONS. Prostate cancer-derived BMP-6 stimulates tumor-associated macrophages to produce IL-1a through a crosstalk between Smad1 and NF-kB1; IL-1a, in turn, promotes angiogenesis and prostate cancer growth.
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Abstract
The iron hormone hepcidin and its receptor and cellular iron exporter ferroportin control the major fluxes of iron into blood plasma: intestinal iron absorption, the delivery of recycled iron from macrophages, and the release of stored iron from hepatocytes. Because iron losses are comparatively very small, iron absorption and its regulation by hepcidin and ferroportin determine total body iron content. Hepcidin is in turn feedback-regulated by plasma iron concentration and iron stores, and negatively regulated by the activity of erythrocyte precursors, the dominant consumers of iron. Hepcidin and ferroportin also play a role in host defense and inflammation, and hepcidin synthesis is induced by inflammatory signals including interleukin-6 and activin B. This review summarizes and discusses recent progress in molecular characterization of systemic iron homeostasis and its disorders, and identifies areas for further investigation.
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Zumbrennen-Bullough K, Babitt JL. The iron cycle in chronic kidney disease (CKD): from genetics and experimental models to CKD patients. Nephrol Dial Transplant 2013; 29:263-73. [PMID: 24235084 DOI: 10.1093/ndt/gft443] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Iron is essential for most living organisms but iron excess can be toxic. Cellular and systemic iron balance is therefore tightly controlled. Iron homeostasis is dysregulated in chronic kidney disease (CKD) and contributes to the anemia that is prevalent in this patient population. Iron supplementation is one cornerstone of anemia management in CKD patients, but has not been rigorously studied in large prospective randomized controlled trials. This review highlights important advances from genetic studies and animal models that have provided key insights into the molecular mechanisms governing iron homeostasis and its disturbance in CKD, and summarizes how these findings may yield advances in the care of this patient population.
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Affiliation(s)
- Kimberly Zumbrennen-Bullough
- Program in Anemia Signaling Research, Division of Nephrology, Program in Membrane Biology, Center for Systems Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
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Abstract
Iron is a micronutrient essential for almost all organisms: bacteria, plants, and animals. It is a metal that exists in multiple redox states, including the divalent ferrous (Fe(2+)) and the trivalent ferric (Fe(3+)) species. The multiple oxidation states of iron make it excellent for electron transfer, allowing iron to be selected during evolution as a cofactor for many proteins involved in central cellular processes including oxygen transport, mitochondrial respiration, and DNA synthesis. However, the redox cycling of ferrous and ferric iron in the presence of H2O2, which is physiologically present in the cells, also leads to the production of free radicals (Fenton reaction) that can attack and damage lipids, proteins, DNA, and other cellular components. To meet the physiological needs of the body, but to prevent cellular damage by iron, the amount of iron in the body must be tightly regulated. Here we review how the liver is the central conductor of systemic iron balance and show that this central role is related to the secretion of a peptide hormone hepcidin by hepatocytes. We then review how the liver receives and integrates the many signals that report the body's iron needs to orchestrate hepcidin production and maintain systemic iron homeostasis.
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Calcitonin gene-related peptide stimulates BMP-2 expression and the differentiation of human osteoblast-like cells in vitro. Acta Pharmacol Sin 2013; 34:1467-74. [PMID: 23708553 DOI: 10.1038/aps.2013.41] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Accepted: 03/25/2013] [Indexed: 01/07/2023] Open
Abstract
AIM To investigate whether bone morphogenic protein-2 (BMP-2) expression was involved in calcitonin gene-related peptide (CGRP)-induced osteogenesis in human osteoblast-like cells in vitro. METHODS MG-63 osteogenic human osteosarcoma cells were treated with CGRP (10-8 mol/L) for 48 h. Cell cycle phases were determined using flow cytometry assay. The protein levels of BMP-2, ALP, Osteocalcin, ColIa1, CREB, and pCREB were measured with Western blotting, while the mRNA level of BMP-2 was measured with qR-T PCR. The expression of ALP in MG-63 cells was also studied using immunofluorescence staining. The level of cAMP was measured with ELISA assay. RESULTS CGRP treatment significantly stimulated proliferation of MG-63 cells, and increased the expression of BMP-2 and the osteogenic proteins ALP, Osteocalcin and ColIa1. Pretreatment with the BMP signaling inhibitor Noggin (100 ng/mL) did not affect CGRP-stimulated proliferation and BMP-2 expression, but abolished the CGRP-induced increases of the osteogenic proteins ALP, Osteocalcin and ColIa1. Furthermore, CGRP treatment markedly increased cAMP level in MG-63 cells, whereas pretreatment with the cAMP pathway inhibitor H89 (5 μmol/L) abolished the CGRP-induced increases of cAMP level and BMP-2 expression. CONCLUSION In MG-63 cells, the BMP pathway is involved in CGRP-induced osteogenic differentiation but not in proliferation, whereas the cAMP/pCREB pathway is involved in the expression of BMP-2.
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Tian C, Liu J. Repulsive guidance molecules (RGMs) and neogenin in bone morphogenetic protein (BMP) signaling. Mol Reprod Dev 2013; 80:700-17. [PMID: 23740870 DOI: 10.1002/mrd.22199] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Accepted: 05/28/2013] [Indexed: 02/06/2023]
Abstract
Bone morphogenetic proteins (BMPs) belong to the transforming growth factor-beta (TGFβ) superfamily. BMPs mediate a highly conserved signal transduction cascade through the type-I and type-II serine/threonine kinase receptors and intracellular Smad proteins, which regulate multiple developmental and homeostatic processes. Mutations in this pathway can cause various diseases in humans, such as skeletal disorders, cardiovascular diseases, and various cancers. Multiple levels of regulation, including extracellular regulation, help to ensure proper spatiotemporal control of BMP signaling in the right cellular context. The family of repulsive guidance molecules (RGMs) and the type-I transmembrane protein neogenin, a paralog of DCC (Deleted in Colorectal Cancer), have been implicated in modulating the BMP pathway. In this review, we discuss the properties and functions of RGM proteins and neogenin, focusing on their roles in the modulation of BMP signal transduction.
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Affiliation(s)
- Chenxi Tian
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York
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