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Sen Z, Weida W, Li Y, Zhaojun L, Nina X, Xiaoguang C. Nicousamide attenuates renal dysfunction and glomerular injury in remnant kidneys by inhibiting TGF-β1 internalisation and renin activity. Eur J Pharmacol 2018; 845:74-84. [PMID: 30586551 DOI: 10.1016/j.ejphar.2018.12.033] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 12/13/2018] [Accepted: 12/20/2018] [Indexed: 12/28/2022]
Abstract
Nicousamide has been shown to exert renal protective effects against diabetic nephropathy and has moved to a phase II clinical trial in China for diabetic nephropathy indication. To expand its clinical indications, 5/6-nephrectomised rats were used to mimic glomerular and vascular sclerosis and tubulointerstitial scarring, with subsequent progression towards end-stage renal disease. Adult Wistar rats underwent 5/6 nephrectomy to induce the development of chronic kidney disease, with a sham operation performed as a control. The nephrectomised animals were treated orally with either saline, nicousamide (7.5,15, or 45 mg/kg), benazepril (4 mg/kg), or losartan (10 mg/kg) daily for 20 weeks. At 8, 16, and 20 weeks of treatment, blood pressure was measured in each animal, and blood and urine samples were collected for biochemical analysis, while kidney remnants were collected for histological examination. Levels of fibronectin and transforming growth factor beta 1 (TGF-β1) were measured in kidneys by immunohistochemistry. Renin activity in the plasma was measured by an enzyme-linked immunosorbent assay. The results showed that nicousamide treatment significantly reduced systemic hypertension, proteinuria, and blood urea nitrogen (P < 0.05), effectively alleviated glomerular sclerosis scores and tubulointerstitial injuries in a dose-dependent manner (P < 0.01), and markedly decreased fibronectin and TGF-β1 levels in kidney tissues of the 5/6-nephrectomised animals. In vitro studies suggested that nicousamide could moderately inhibit the renin activity and strongly block the TGF-β1 internalisation into fibroblast cells. In summary, nicousamide may protect from renal failure through dual targeting, which involves a TGF-β1-dependent mechanism and inhibition of renin activity.
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Affiliation(s)
- Zhang Sen
- State Key Laboratory of Bioactive Substances and Function of Natural Medicine, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, PR China.
| | - Wang Weida
- State Key Laboratory of Bioactive Substances and Function of Natural Medicine, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, PR China
| | - Yan Li
- State Key Laboratory of Bioactive Substances and Function of Natural Medicine, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, PR China
| | - Li Zhaojun
- State Key Laboratory of Bioactive Substances and Function of Natural Medicine, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, PR China
| | - Xue Nina
- State Key Laboratory of Bioactive Substances and Function of Natural Medicine, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, PR China
| | - Chen Xiaoguang
- State Key Laboratory of Bioactive Substances and Function of Natural Medicine, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, PR China.
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The TGF-β co-receptor, CD109, promotes internalization and degradation of TGF-β receptors. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2011; 1813:742-53. [PMID: 21295082 DOI: 10.1016/j.bbamcr.2011.01.028] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2010] [Revised: 01/19/2011] [Accepted: 01/24/2011] [Indexed: 12/16/2022]
Abstract
Transforming growth factor-β (TGF-β) is implicated in numerous pathological disorders, including cancer and mediates a broad range of biological responses by signaling through the type I and II TGF-β receptors. Internalization of these receptors via the clathrin-coated pits pathway facilitates SMAD-mediated signaling, whereas internalization via the caveolae pathway is associated with receptor degradation. Thus, molecules that modulate receptor endocytosis are likely to play a critical role in regulating TGF-β action. We previously identified CD109, a GPI-anchored protein, as a TGF-β co-receptor and a negative regulator of TGF-β signaling. Here, we demonstrate that CD109 associates with caveolin-1, a major component of the caveolae. Moreover, CD109 increases binding of TGF-β to its receptors and enhances their internalization via the caveolae. In addition, CD109 promotes localization of the TGF-β receptors into the caveolar compartment in the presence of ligand and facilitates TGF-β-receptor degradation. Thus, CD109 regulates TGF-β receptor endocytosis and degradation to inhibit TGF-β signaling. This article is part of a Special Issue entitled: 11th European Symposium on Calcium.
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Wehner LE, Folz BJ, Argyriou L, Twelkemeyer S, Teske U, Geisthoff UW, Werner JA, Engel W, Nayernia K. Mutation analysis in hereditary haemorrhagic telangiectasia in Germany reveals 11 novel ENG and 12 novel ACVRL1/ALK1 mutations. Clin Genet 2006; 69:239-45. [PMID: 16542389 DOI: 10.1111/j.1399-0004.2006.00574.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Hereditary haemorrhagic telangiectasia (HHT) is an autosomal-dominant disease characterized by recurrent epistaxis, mucocutaneous telangiectasias and visceral arteriovenous malformations. Mutations in endoglin (ENG) and activin A receptor type II-like kinase 1 (ACVRL1 or ALK1) have been found in patients with HHT. We have screened a total of 51 unselected German index cases with the suspected diagnosis of HHT. We identified 30 different mutations in 32 cases (62.7%) by direct sequencing. Among these mutations, 11 of 13 ENG mutations and 12 of 17 ACVRL1 mutations were not previously reported in the literature. Two of the ACVRL1 mutations were each shared by two families. An analysis of the genotype-phenotype correlation is consistent with a more common frequency of pulmonary arteriovenous malformations in patients with ENG mutations than in patients with ACVRL1 mutations in our collective.
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Affiliation(s)
- L-E Wehner
- Institute of Human Genetics, Georg-August University, Göttingen, Germary
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Abstract
Activins and bone morphogenetic proteins (BMPs) elicit diverse biological responses by signaling through two pairs of structurally related types I and II receptors. Here, we summarize recent advances in understanding the mode of action of activins and BMPs, focusing on our elucidation of the crystal structure of BMP-7 in complex with the extracellular domain (ECD) of the activin type II receptor and our identification of a binding site for activin on the type I receptor ALK4. As a consequence of the broad range of activities of activins and BMPs, it is perhaps not surprising that additional mechanisms are continually being discovered through which a cell's responsiveness to these ligands is modulated. In this review, we describe novel ways in which the two extracellular cofactors, betaglycan and Cripto, regulate BMP and/or activin signal transduction.
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Affiliation(s)
- Craig A Harrison
- Clayton Foundation Laboratories for Peptide Biology, The Salk Institute, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
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Harrison CA, Gray PC, Koerber SC, Fischer W, Vale W. Identification of a functional binding site for activin on the type I receptor ALK4. J Biol Chem 2003; 278:21129-35. [PMID: 12665502 DOI: 10.1074/jbc.m302015200] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Activins, like other members of the transforming growth factor-beta (TGF-beta) superfamily, initiate signaling by assembling a complex of two types of transmembrane serine/threonine receptor kinases classified as type II (ActRII or ActRIIB) and type I (ALK4). A kinase-deleted version of ALK4 can form an inactive complex with activin and ActRII/IIB and thereby acts in a dominant negative manner to block activin signaling. Using the complex structure of bone morphogenetic protein-2 bound to its type I receptor (ALK3) as a guide, we introduced extracellular domain mutations in the context of the truncated ALK4 (ALK4-trunc) construct and assessed the ability of the mutants to inhibit activin function. We have identified five hydrophobic amino acid residues on the ALK4 extracellular domain (Leu40, Ile70, Val73, Leu75, and Pro77) that, when mutated to alanine, have substantial effects on ALK4-trunc dominant negative activity. In addition, eleven mutants partially affected activin binding to ALK4. Together, these residues likely constitute the binding surface for activin on ALK4. Cross-linking studies measuring binding of 125I-activin-A to the ALK4-trunc mutants in the presence of ActRII implicated the same residues. Our results indicate that there is only a partial overlap of the binding sites on ALK4 and ALK3 for activin-A and bone morphogenetic protein-2, respectively. In addition three of the residues required for activin binding to ALK4 are conserved on the type I TGF-beta receptor ALK5, suggesting the corresponding region on ALK5 may be important for TGF-beta binding.
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MESH Headings
- Activin Receptors, Type I/chemistry
- Activin Receptors, Type I/genetics
- Activin Receptors, Type I/metabolism
- Activins/metabolism
- Amino Acids/genetics
- Animals
- Binding Sites
- Bone Morphogenetic Protein Receptors, Type I
- Cells, Cultured
- Epithelial Cells/cytology
- Epithelial Cells/physiology
- Gene Expression
- Humans
- Kidney/cytology
- Lung/cytology
- Mink
- Molecular Sequence Data
- Mutagenesis
- Protein Serine-Threonine Kinases
- Protein Structure, Tertiary
- Proteins
- Receptor, Transforming Growth Factor-beta Type I
- Receptors, Growth Factor
- Receptors, Transforming Growth Factor beta/chemistry
- Receptors, Transforming Growth Factor beta/genetics
- Receptors, Transforming Growth Factor beta/metabolism
- Sequence Homology, Amino Acid
- Structure-Activity Relationship
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Affiliation(s)
- Craig A Harrison
- Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, La Jolla, California 92037, USA
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Abdalla SA, Cymerman U, Johnson RM, Deber CM, Letarte M. Disease-associated mutations in conserved residues of ALK-1 kinase domain. Eur J Hum Genet 2003; 11:279-87. [PMID: 12700602 DOI: 10.1038/sj.ejhg.5200919] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Activin receptor-like kinase-1 (ALK-1), the gene mutated in HHT type 2 (HHT2), is a serine/threonine kinase receptor type I of the TGF-beta superfamily, specifically expressed on endothelial cells. We established an HHT2 genotype in 16 families and report nine novel mutations. These include insertions and deletions of single base pairs in exons 3, 8 and 9, as well as nonsense mutations in exons 4 and 8 of ALK-1, which would lead to premature truncation and unstable mRNA or protein. Three novel missense mutations were identified in exons 7 and 8 of the kinase domain. Five previously reported substitutions were also observed in the families analyzed. Our results bring to 36, the number of mutations associated with HHT2, and are mostly found in exons 8 and 3 followed by exons 4 and 7. To ascertain the potential functional implications of the missense mutations in the ALK-1 kinase domain, we generated a model based on the three-dimensional structure of the homologous ALK-5 kinase domain. Our data reveal that the 11 missense mutations modify residues conserved among type I receptors and alter the polarity, charge, hydrophobicity and/or size of the substituted amino-acid and likely lead to misfolded and nonfunctional proteins.
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Affiliation(s)
- Salma A Abdalla
- Cancer and Blood Research program, The Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada M5G 1X8, USA.
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Krause CD, Mei E, Xie J, Jia Y, Bopp MA, Hochstrasser RM, Pestka S. Seeing the light: preassembly and ligand-induced changes of the interferon gamma receptor complex in cells. Mol Cell Proteomics 2002; 1:805-15. [PMID: 12438563 DOI: 10.1074/mcp.m200065-mcp200] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Our experiments were designed to test the hypothesis that the cell surface interferon gamma receptor chains are preassembled rather than associated by ligand and to assess the molecular changes on ligand binding. To accomplish this, we used fluorescence resonance energy transfer, a powerful spectroscopic technique that has been used to determine molecular interactions and distances between the donor and acceptor. However, current commercial instruments do not provide sufficient sensitivity or the full spectra to provide decisive results of interactions between proteins labeled with blue and green fluorescent proteins in living cells. In our experiments, we used the blue fluorescent protein and green fluorescent protein pair, attached a monochrometer and charge-coupled device camera to a modified confocal microscope, reduced background fluorescence with the use of two-photon excitation, and focused on regions of single cells to provide clear spectra of fluorescence resonance energy transfer. In contrast to the prevailing view, the results demonstrate that the receptor chains are preassociated and that the intracellular domains move apart on binding the ligand interferon gamma. Application of this technology should lead to new rapid methods for high throughput screening and delineation of the interactome of cells.
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Affiliation(s)
- Christopher D Krause
- Department of Molecular Genetics, Microbiology and Immunology, Robert Wood Johnson Medical School-University of Medicine and Dentistry of New Jersey, Piscataway 08854-5635, USA
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