1
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Wilk SS, Michalak K, Owczarek EP, Winiarczyk S, Zabielska-Koczywąs KA. Proteomic Analyses Reveal the Role of Alpha-2-Macroglobulin in Canine Osteosarcoma Cell Migration. Int J Mol Sci 2024; 25:3989. [PMID: 38612805 PMCID: PMC11011979 DOI: 10.3390/ijms25073989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 03/25/2024] [Accepted: 03/29/2024] [Indexed: 04/14/2024] Open
Abstract
Canine osteosarcoma (OSA) is an aggressive bone neoplasia with high metastatic potential. Metastasis is the main cause of death associated with OSA, and there is no current treatment available for metastatic disease. Proteomic analyses, including matrix-assisted laser desorption/ionisation-time of flight mass spectrometry (MALDI TOF/TOF MS), are widely used to select molecular targets and identify proteins that may play a key role in primary tumours and at various steps of the metastatic cascade. The main aim of this study was to identify proteins differently expressed in canine OSA cell lines with different malignancy phenotypes (OSCA-8 and OSCA-32) compared to canine osteoblasts (CnOb). The intermediate aim of the study was to compare canine OSA cell migration capacity and assess its correlation with the malignancy phenotypes of each cell line. Using MALDI-TOF/TOF MS analyses, we identified eight proteins that were significantly differentially expressed (p ≤ 0.05) in canine OSA cell lines compared to CnOb: cilia- and flagella-associated protein 298 (CFAP298), general transcription factor II-I (GTF2I), mirror-image polydactyly gene 1 protein (MIPOL1), alpha-2 macroglobulin (A2M), phosphoglycerate mutase 1 (PGAM1), ubiquitin (UB2L6), ectodysplasin-A receptor-associated adapter protein (EDARADD), and leucine-rich-repeat-containing protein 72 (LRRC72). Using the Simple Western technique, we confirmed high A2M expression in CnOb compared to OSCA-8 and OSCA-32 cell lines (with intermediate and low A2M expression, respectively). Then, we confirmed the role of A2M in cancer cell migration by demonstrating significantly inhibited OSA cell migration by treatment with A2M (both at 10 and 30 mM concentrations after 12 and 24 h) in a wound-healing assay. This study may be the first report indicating A2M's role in OSA cell metastasis; however, further in vitro and in vivo studies are needed to confirm its possible role as an anti-metastatic agent in this malignancy.
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Affiliation(s)
- Sylwia S. Wilk
- Department of Small Animal Diseases and Clinic, Institute of Veterinary Medicine, Warsaw University of Life Sciences, Nowoursynowska 159c, 02-787 Warsaw, Poland; (S.S.W.); (E.P.O.)
| | - Katarzyna Michalak
- Department of Epizootiology and Clinic of Infectious Diseases, University of Life Sciences, Głęboka 30, 20-612 Lublin, Poland; (K.M.); (S.W.)
| | - Ewelina P. Owczarek
- Department of Small Animal Diseases and Clinic, Institute of Veterinary Medicine, Warsaw University of Life Sciences, Nowoursynowska 159c, 02-787 Warsaw, Poland; (S.S.W.); (E.P.O.)
- Laboratory of RNA Biology, International Institute of Molecular and Cell Biology in Warsaw, 4 Ks. Trojdena, 02-109 Warsaw, Poland
| | - Stanisław Winiarczyk
- Department of Epizootiology and Clinic of Infectious Diseases, University of Life Sciences, Głęboka 30, 20-612 Lublin, Poland; (K.M.); (S.W.)
- National Veterinary Research Institute, Aleja Partyzantów 5, 24-100 Puławy, Poland
| | - Katarzyna A. Zabielska-Koczywąs
- Department of Small Animal Diseases and Clinic, Institute of Veterinary Medicine, Warsaw University of Life Sciences, Nowoursynowska 159c, 02-787 Warsaw, Poland; (S.S.W.); (E.P.O.)
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2
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Munshaw S, Redpath AN, Pike BT, Smart N. Thymosin β4 preserves vascular smooth muscle phenotype in atherosclerosis via regulation of low density lipoprotein related protein 1 (LRP1). Int Immunopharmacol 2023; 115:109702. [PMID: 37724952 PMCID: PMC10666903 DOI: 10.1016/j.intimp.2023.109702] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 12/29/2022] [Indexed: 01/21/2023]
Abstract
Atherosclerosis is a progressive, degenerative vascular disease and a leading cause of morbidity and mortality. In response to endothelial damage, platelet derived growth factor (PDGF)-BB induced phenotypic modulation of medial smooth muscle cells (VSMCs) promotes atherosclerotic lesion formation and destabilisation of the vessel wall. VSMC sensitivity to PDGF-BB is determined by endocytosis of Low density lipoprotein receptor related protein 1 (LRP1)-PDGFR β complexes to balance receptor recycling with lysosomal degradation. Consequently, LRP1 is implicated in various arterial diseases. Having identified Tβ4 as a regulator of LRP1-mediated endocytosis to protect against aortic aneurysm, we sought to determine whether Tβ4 may additionally function to protect against atherosclerosis, by regulating LRP1-mediated growth factor signalling. By single cell transcriptomic analysis, Tmsb4x, encoding Tβ4, strongly correlated with contractile gene expression and was significantly down-regulated in cells that adopted a modulated phenotype in atherosclerosis. We assessed susceptibility to atherosclerosis of global Tβ4 knockout mice using the ApoE-/- hypercholesterolaemia model. Inflammation, elastin integrity, VSMC phenotype and signalling were analysed in the aortic root and descending aorta. Tβ4KO; ApoE-/- mice develop larger atherosclerotic plaques than control mice, with medial layer degeneration characterised by accelerated VSMC phenotypic modulation. Defects in Tβ4KO; ApoE-/- mice phenocopied those in VSMC-specific LRP1 nulls and, moreover, were underpinned by hyperactivated LRP1-PDGFRβ signalling. We identify an atheroprotective role for endogenous Tβ4 in maintaining differentiated VSMC phenotype via LRP1-mediated PDGFRβ signalling.
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Affiliation(s)
- Sonali Munshaw
- Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy & Genetics, University of Oxford, Sherrington Building, South Parks Road, Oxford OX1 3PT, UK
| | - Andia N Redpath
- Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy & Genetics, University of Oxford, Sherrington Building, South Parks Road, Oxford OX1 3PT, UK; Institute of Developmental and Regenerative Medicine, University of Oxford, IMS-Tetsuya Nakamura Building, Old Road Campus, Oxford OX3 7TY, UK
| | - Benjamin T Pike
- Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy & Genetics, University of Oxford, Sherrington Building, South Parks Road, Oxford OX1 3PT, UK
| | - Nicola Smart
- Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy & Genetics, University of Oxford, Sherrington Building, South Parks Road, Oxford OX1 3PT, UK; Institute of Developmental and Regenerative Medicine, University of Oxford, IMS-Tetsuya Nakamura Building, Old Road Campus, Oxford OX3 7TY, UK.
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3
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Zhang JM, Au DT, Sawada H, Franklin MK, Moorleghen JJ, Howatt DA, Wang P, Aicher BO, Hampton B, Migliorini M, Ni F, Mullick AE, Wani MM, Ucuzian AA, Lu HS, Muratoglu SC, Daugherty A, Strickland DK. LRP1 protects against excessive superior mesenteric artery remodeling by modulating angiotensin II-mediated signaling. JCI Insight 2023; 8:e164751. [PMID: 36472907 PMCID: PMC9977308 DOI: 10.1172/jci.insight.164751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 11/30/2022] [Indexed: 12/12/2022] Open
Abstract
Vascular smooth muscle cells (vSMCs) exert a critical role in sensing and maintaining vascular integrity. These cells abundantly express the low-density lipoprotein receptor-related protein 1 (LRP1), a large endocytic signaling receptor that recognizes numerous ligands, including apolipoprotein E-rich lipoproteins, proteases, and protease-inhibitor complexes. We observed the spontaneous formation of aneurysms in the superior mesenteric artery (SMA) of both male and female mice in which LRP1 was genetically deleted in vSMCs (smLRP1-/- mice). Quantitative proteomics revealed elevated abundance of several proteins in smLRP1-/- mice that are known to be induced by angiotensin II-mediated (AngII-mediated) signaling, suggesting that this pathway was dysregulated. Administration of losartan, an AngII type I receptor antagonist, or an angiotensinogen antisense oligonucleotide to reduce plasma angiotensinogen concentrations restored the normal SMA phenotype in smLRP1-/- mice and prevented aneurysm formation. Additionally, using a vascular injury model, we noted excessive vascular remodeling and neointima formation in smLRP1-/- mice that was restored by losartan administration. Together, these findings reveal that LRP1 regulates vascular integrity and remodeling of the SMA by attenuating excessive AngII-mediated signaling.
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Affiliation(s)
- Jackie M Zhang
- Center for Vascular and Inflammatory Diseases and
- Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Dianaly T Au
- Center for Vascular and Inflammatory Diseases and
| | - Hisashi Sawada
- Saha Cardiovascular Research Center and Saha Aortic Center and
- Department of Physiology, University of Kentucky, Lexington, Kentucky, USA
| | | | | | | | - Pengjun Wang
- Saha Cardiovascular Research Center and Saha Aortic Center and
| | - Brittany O Aicher
- Center for Vascular and Inflammatory Diseases and
- Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | | | | | - Fenge Ni
- Center for Vascular and Inflammatory Diseases and
| | | | | | - Areck A Ucuzian
- Center for Vascular and Inflammatory Diseases and
- Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Vascular Services, Baltimore Veterans Affairs Medical Center, Baltimore, Maryland, USA
| | - Hong S Lu
- Saha Cardiovascular Research Center and Saha Aortic Center and
- Department of Physiology, University of Kentucky, Lexington, Kentucky, USA
| | | | - Alan Daugherty
- Saha Cardiovascular Research Center and Saha Aortic Center and
- Department of Physiology, University of Kentucky, Lexington, Kentucky, USA
| | - Dudley K Strickland
- Center for Vascular and Inflammatory Diseases and
- Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland, USA
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4
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Borges TJ, Murshid A, Theriault J, Calderwood SK. Molecular Chaperone Receptors: An Update. Methods Mol Biol 2023; 2693:193-208. [PMID: 37540436 DOI: 10.1007/978-1-0716-3342-7_15] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/05/2023]
Abstract
Extracellular heat shock proteins (HSP) play important roles in cell signaling and immunity. Many of these effects are mediated by surface receptors expressed on a wide range of cell types, including immune cells. We have investigated the nature of such proteins by cloning candidate receptors into cells (CHO-K1) with the rare property of being null for HSP binding. Using this approach, we have discovered that mammalian and eukaryotic Hsp70 binds avidly to at least three classes of receptor including: (1) c-type lectin receptors (CLR), (2) scavenger receptors (SR) and (3) lectins. However, the structural nature of the receptor-ligand interactions is not currently clear. Hsp70 can bind to LOX-1 (a member of both the CLR and SR), with the c-type lectin binding domain (CTLD), to the SR family members SREC-I and FEEL-1/CLEVER-1/STABILIN-1, which by contrast have arrays of EGF-like repeats in their extracellular domains as well. In this chapter, we will discuss: (1) methods for the discovery of HSP receptors, (2) approaches to the study of individual receptors in cells that contain multiple such receptors and (3) methods for investigating HSP receptor function in vivo.
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Affiliation(s)
- Thiago J Borges
- Center for Transplantation Sciences, Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Ayesha Murshid
- Molecular and Cellular Radiation Oncology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Jimmy Theriault
- Molecular and Cellular Radiation Oncology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Stuart K Calderwood
- Molecular and Cellular Radiation Oncology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
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5
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Chen J, Su Y, Pi S, Hu B, Mao L. The Dual Role of Low-Density Lipoprotein Receptor-Related Protein 1 in Atherosclerosis. Front Cardiovasc Med 2021; 8:682389. [PMID: 34124208 PMCID: PMC8192809 DOI: 10.3389/fcvm.2021.682389] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 05/05/2021] [Indexed: 12/26/2022] Open
Abstract
Low-density lipoprotein receptor–related protein-1 (LRP1) is a large endocytic and signaling receptor belonging to the LDL receptor (LDLR) gene family and that is widely expressed in several tissues. LRP1 comprises a large extracellular domain (ECD; 515 kDa, α chain) and a small intracellular domain (ICD; 85 kDa, β chain). The deletion of LRP1 leads to embryonic lethality in mice, revealing a crucial but yet undefined role in embryogenesis and development. LRP1 has been postulated to participate in numerous diverse physiological and pathological processes ranging from plasma lipoprotein homeostasis, atherosclerosis, tumor evolution, and fibrinolysis to neuronal regeneration and survival. Many studies using cultured cells and in vivo animal models have revealed the important roles of LRP1 in vascular remodeling, foam cell biology, inflammation and atherosclerosis. However, its role in atherosclerosis remains controversial. LRP1 not only participates in the removal of atherogenic lipoproteins and proatherogenic ligands in the liver but also mediates the uptake of aggregated LDL to promote the formation of macrophage- and vascular smooth muscle cell (VSMC)-derived foam cells, which causes a prothrombotic transformation of the vascular wall. The dual and opposing roles of LRP1 may also represent an interesting target for atherosclerosis therapeutics. This review highlights the influence of LRP1 during atherosclerosis development, focusing on its dual role in vascular cells and immune cells.
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Affiliation(s)
- Jiefang Chen
- Department of Neurology, Tongji Medical College, Union Hospital, Huazhong University of Science and Technology, Wuhan, China
| | - Ying Su
- Department of Neurology, Tongji Medical College, Union Hospital, Huazhong University of Science and Technology, Wuhan, China
| | - Shulan Pi
- Department of Neurology, Tongji Medical College, Union Hospital, Huazhong University of Science and Technology, Wuhan, China
| | - Bo Hu
- Department of Neurology, Tongji Medical College, Union Hospital, Huazhong University of Science and Technology, Wuhan, China
| | - Ling Mao
- Department of Neurology, Tongji Medical College, Union Hospital, Huazhong University of Science and Technology, Wuhan, China
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6
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Munshaw S, Bruche S, Redpath AN, Jones A, Patel J, Dubé KN, Lee R, Hester SS, Davies R, Neal G, Handa A, Sattler M, Fischer R, Channon KM, Smart N. Thymosin β4 protects against aortic aneurysm via endocytic regulation of growth factor signaling. J Clin Invest 2021; 131:127884. [PMID: 33784254 PMCID: PMC8121525 DOI: 10.1172/jci127884] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 03/23/2021] [Indexed: 01/06/2023] Open
Abstract
Vascular stability and tone are maintained by contractile smooth muscle cells (VSMCs). However, injury-induced growth factors stimulate a contractile-synthetic phenotypic modulation which increases susceptibility to abdominal aortic aneurysm (AAA). As a regulator of embryonic VSMC differentiation, we hypothesized that Thymosin β4 (Tβ4) may function to maintain healthy vasculature throughout postnatal life. This was supported by the identification of an interaction with low density lipoprotein receptor related protein 1 (LRP1), an endocytic regulator of platelet-derived growth factor BB (PDGF-BB) signaling and VSMC proliferation. LRP1 variants have been implicated by genome-wide association studies with risk of AAA and other arterial diseases. Tβ4-null mice displayed aortic VSMC and elastin defects that phenocopy those of LRP1 mutants, and their compromised vascular integrity predisposed them to Angiotensin II-induced aneurysm formation. Aneurysmal vessels were characterized by enhanced VSMC phenotypic modulation and augmented PDGFR-β signaling. In vitro, enhanced sensitivity to PDGF-BB upon loss of Tβ4 was associated with dysregulated endocytosis, with increased recycling and reduced lysosomal targeting of LRP1-PDGFR-β. Accordingly, the exacerbated aneurysmal phenotype in Tβ4-null mice was rescued upon treatment with the PDGFR-β antagonist Imatinib. Our study identifies Tβ4 as a key regulator of LRP1 for maintaining vascular health, and provides insights into the mechanisms of growth factor-controlled VSMC phenotypic modulation underlying aortic disease progression.
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MESH Headings
- Angiotensin II/adverse effects
- Angiotensin II/pharmacology
- Animals
- Aortic Aneurysm, Abdominal/chemically induced
- Aortic Aneurysm, Abdominal/genetics
- Aortic Aneurysm, Abdominal/metabolism
- Aortic Aneurysm, Abdominal/prevention & control
- Becaplermin/genetics
- Becaplermin/metabolism
- Low Density Lipoprotein Receptor-Related Protein-1/genetics
- Low Density Lipoprotein Receptor-Related Protein-1/metabolism
- Male
- Mice
- Mice, Knockout
- Muscle, Smooth, Vascular/metabolism
- Myocytes, Smooth Muscle/metabolism
- Receptor, Platelet-Derived Growth Factor beta/genetics
- Receptor, Platelet-Derived Growth Factor beta/metabolism
- Signal Transduction/drug effects
- Signal Transduction/genetics
- Thymosin/genetics
- Thymosin/metabolism
- Thymosin/pharmacology
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Affiliation(s)
- Sonali Munshaw
- Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy & Genetics, University of Oxford, Sherrington Building, Oxford, United Kingdom
| | - Susann Bruche
- Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy & Genetics, University of Oxford, Sherrington Building, Oxford, United Kingdom
| | - Andia N. Redpath
- Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy & Genetics, University of Oxford, Sherrington Building, Oxford, United Kingdom
| | - Alisha Jones
- Institute of Structural Biology, Helmholtz Zentrum München, Neuherberg, Munich, Germany
- Biomolecular NMR and Center for Integrated Protein Science Munich at Chemistry Department, Technical University of Munich, Garching, Munich, Germany
| | - Jyoti Patel
- BHF Centre of Research Excellence, Division of Cardiovascular Medicine, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
| | | | - Regent Lee
- Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom
| | - Svenja S. Hester
- Nuffield Department of Medicine, Target Discovery Institute, University of Oxford, Oxford, United Kingdom
| | - Rachel Davies
- Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy & Genetics, University of Oxford, Sherrington Building, Oxford, United Kingdom
| | - Giles Neal
- Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy & Genetics, University of Oxford, Sherrington Building, Oxford, United Kingdom
| | - Ashok Handa
- Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom
| | - Michael Sattler
- Institute of Structural Biology, Helmholtz Zentrum München, Neuherberg, Munich, Germany
- Biomolecular NMR and Center for Integrated Protein Science Munich at Chemistry Department, Technical University of Munich, Garching, Munich, Germany
| | - Roman Fischer
- Nuffield Department of Medicine, Target Discovery Institute, University of Oxford, Oxford, United Kingdom
| | - Keith M. Channon
- BHF Centre of Research Excellence, Division of Cardiovascular Medicine, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
| | - Nicola Smart
- Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy & Genetics, University of Oxford, Sherrington Building, Oxford, United Kingdom
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7
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Mineo C. Lipoprotein receptor signalling in atherosclerosis. Cardiovasc Res 2021; 116:1254-1274. [PMID: 31834409 DOI: 10.1093/cvr/cvz338] [Citation(s) in RCA: 85] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 11/01/2019] [Accepted: 12/10/2019] [Indexed: 12/11/2022] Open
Abstract
The founding member of the lipoprotein receptor family, low-density lipoprotein receptor (LDLR) plays a major role in the atherogenesis through the receptor-mediated endocytosis of LDL particles and regulation of cholesterol homeostasis. Since the discovery of the LDLR, many other structurally and functionally related receptors have been identified, which include low-density lipoprotein receptor-related protein (LRP)1, LRP5, LRP6, very low-density lipoprotein receptor, and apolipoprotein E receptor 2. The scavenger receptor family members, on the other hand, constitute a family of pattern recognition proteins that are structurally diverse and recognize a wide array of ligands, including oxidized LDL. Among these are cluster of differentiation 36, scavenger receptor class B type I and lectin-like oxidized low-density lipoprotein receptor-1. In addition to the initially assigned role as a mediator of the uptake of macromolecules into the cell, a large number of studies in cultured cells and in in vivo animal models have revealed that these lipoprotein receptors participate in signal transduction to modulate cellular functions. This review highlights the signalling pathways by which these receptors influence the process of atherosclerosis development, focusing on their roles in the vascular cells, such as macrophages, endothelial cells, smooth muscle cells, and platelets. Human genetics of the receptors is also discussed to further provide the relevance to cardiovascular disease risks in humans. Further knowledge of the vascular biology of the lipoprotein receptors and their ligands will potentially enhance our ability to harness the mechanism to develop novel prophylactic and therapeutic strategies against cardiovascular diseases.
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Affiliation(s)
- Chieko Mineo
- Department of Pediatrics and Cell Biology, Center for Pulmonary and Vascular Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9063, USA
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8
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Arai AL, Migliorini M, Au DT, Hahn-Dantona E, Peeney D, Stetler-Stevenson WG, Muratoglu SC, Strickland DK. High-Affinity Binding of LDL Receptor-Related Protein 1 to Matrix Metalloprotease 1 Requires Protease:Inhibitor Complex Formation. Biochemistry 2020; 59:2922-2933. [PMID: 32702237 DOI: 10.1021/acs.biochem.0c00442] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Matrix metalloprotease (MMP) activation contributes to the degradation of the extracellular matrix (ECM), resulting in a multitude of pathologies. Low-density lipoprotein receptor-related protein 1 (LRP1) is a multifaceted endocytic and signaling receptor that is responsible for internalization and lysosomal degradation of diverse proteases, protease inhibitors, and lipoproteins along with numerous other proteins. In this study, we identified MMP-1 as a novel LRP1 ligand. Binding studies employing surface plasmon resonance revealed that both proMMP-1 and active MMP-1 bind to purified LRP1 with equilibrium dissociation constants (KD) of 19 and 25 nM, respectively. We observed that human aortic smooth muscle cells readily internalize and degrade 125I-labeled proMMP-1 in an LRP1-mediated process. Our binding data also revealed that all tissue inhibitors of metalloproteases (TIMPs) bind to LRP1 with KD values ranging from 23 to 33 nM. Interestingly, the MMP-1/TIMP-1 complex bound to LRP1 with an affinity (KD = 0.6 nM) that was 30-fold higher than that of either component alone, revealing that LRP1 prefers the protease:inhibitor complex as a ligand. Of note, modification of lysine residues on either proMMP-1 or TIMP-1 ablated the ability of the MMP-1/TIMP-1 complex to bind to LRP1. LRP1's preferential binding to enzyme:inhibitor complexes was further supported by the higher binding affinity for proMMP-9/TIMP-1 complexes than for either of these two components alone. LRP1 has four clusters of ligand-binding repeats, and MMP-1, TIMP-1, and MMP-1/TIMP-1 complexes bound to cluster III most avidly. Our results reveal an important role for LRP1 in controlling ECM homeostasis by regulating MMP-1 and MMP-9 levels.
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Affiliation(s)
| | | | | | | | - David Peeney
- Extracellular Matrix Pathology Section, Laboratory of Pathology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - William G Stetler-Stevenson
- Extracellular Matrix Pathology Section, Laboratory of Pathology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, United States
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9
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Campion O, Al Khalifa T, Langlois B, Thevenard-Devy J, Salesse S, Savary K, Schneider C, Etique N, Dedieu S, Devy J. Contribution of the Low-Density Lipoprotein Receptor Family to Breast Cancer Progression. Front Oncol 2020; 10:882. [PMID: 32850302 PMCID: PMC7406569 DOI: 10.3389/fonc.2020.00882] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 05/05/2020] [Indexed: 12/18/2022] Open
Abstract
The low-density lipoprotein receptor (LDLR) family comprises 14 single-transmembrane receptors sharing structural homology and common repeats. These receptors specifically recognize and internalize various extracellular ligands either alone or complexed with membrane-spanning co-receptors that are then sorted for lysosomal degradation or cell-surface recovery. As multifunctional endocytic receptors, some LDLR members from the core family were first considered as potential tumor suppressors due to their clearance activity against extracellular matrix-degrading enzymes. LDLRs are also involved in pleiotropic functions including growth factor signaling, matricellular proteins, and cell matrix adhesion turnover and chemoattraction, thereby affecting both tumor cells and their surrounding microenvironment. Therefore, their roles could appear controversial and dependent on the malignancy state. In this review, recent advances highlighting the contribution of LDLR members to breast cancer progression are discussed with focus on (1) specific expression patterns of these receptors in primary cancers or distant metastasis and (2) emerging mechanisms and signaling pathways. In addition, potential diagnosis and therapeutic options are proposed.
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Affiliation(s)
- Océane Campion
- Université de Reims Champagne-Ardenne (URCA), Reims, France.,CNRS UMR 7369, Matrice Extracellulaire et Dynamique Cellulaire, MEDyC, Reims, France
| | - Tesnim Al Khalifa
- Université de Reims Champagne-Ardenne (URCA), Reims, France.,CNRS UMR 7369, Matrice Extracellulaire et Dynamique Cellulaire, MEDyC, Reims, France
| | - Benoit Langlois
- Université de Reims Champagne-Ardenne (URCA), Reims, France.,CNRS UMR 7369, Matrice Extracellulaire et Dynamique Cellulaire, MEDyC, Reims, France
| | - Jessica Thevenard-Devy
- Université de Reims Champagne-Ardenne (URCA), Reims, France.,CNRS UMR 7369, Matrice Extracellulaire et Dynamique Cellulaire, MEDyC, Reims, France
| | - Stéphanie Salesse
- Université de Reims Champagne-Ardenne (URCA), Reims, France.,CNRS UMR 7369, Matrice Extracellulaire et Dynamique Cellulaire, MEDyC, Reims, France
| | - Katia Savary
- Université de Reims Champagne-Ardenne (URCA), Reims, France.,CNRS UMR 7369, Matrice Extracellulaire et Dynamique Cellulaire, MEDyC, Reims, France
| | - Christophe Schneider
- Université de Reims Champagne-Ardenne (URCA), Reims, France.,CNRS UMR 7369, Matrice Extracellulaire et Dynamique Cellulaire, MEDyC, Reims, France
| | - Nicolas Etique
- Université de Reims Champagne-Ardenne (URCA), Reims, France.,CNRS UMR 7369, Matrice Extracellulaire et Dynamique Cellulaire, MEDyC, Reims, France
| | - Stéphane Dedieu
- Université de Reims Champagne-Ardenne (URCA), Reims, France.,CNRS UMR 7369, Matrice Extracellulaire et Dynamique Cellulaire, MEDyC, Reims, France
| | - Jérôme Devy
- Université de Reims Champagne-Ardenne (URCA), Reims, France.,CNRS UMR 7369, Matrice Extracellulaire et Dynamique Cellulaire, MEDyC, Reims, France
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10
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Au DT, Arai AL, Fondrie WE, Muratoglu SC, Strickland DK. Role of the LDL Receptor-Related Protein 1 in Regulating Protease Activity and Signaling Pathways in the Vasculature. Curr Drug Targets 2019; 19:1276-1288. [PMID: 29749311 DOI: 10.2174/1389450119666180511162048] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 04/24/2018] [Accepted: 04/24/2018] [Indexed: 12/22/2022]
Abstract
Aortic aneurysms represent a significant clinical problem as they largely go undetected until a rupture occurs. Currently, an understanding of mechanisms leading to aneurysm formation is limited. Numerous studies clearly indicate that vascular smooth muscle cells play a major role in the development and response of the vasculature to hemodynamic changes and defects in these responses can lead to aneurysm formation. The LDL receptor-related protein 1 (LRP1) is major smooth muscle cell receptor that has the capacity to mediate the endocytosis of numerous ligands and to initiate and regulate signaling pathways. Genetic evidence in humans and mouse models reveal a critical role for LRP1 in maintaining the integrity of the vasculature. Understanding the mechanisms by which this is accomplished represents an important area of research, and likely involves LRP1's ability to regulate levels of proteases known to degrade the extracellular matrix as well as its ability to modulate signaling events.
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Affiliation(s)
- Dianaly T Au
- Center for Vascular and Inflammatory Diseases, Biopark I, R213, 800 W. Baltimore Street, Baltimore, Maryland 21201, MD, United States
| | - Allison L Arai
- Center for Vascular and Inflammatory Diseases, Biopark I, R213, 800 W. Baltimore Street, Baltimore, Maryland 21201, MD, United States
| | - William E Fondrie
- Center for Vascular and Inflammatory Diseases, Biopark I, R213, 800 W. Baltimore Street, Baltimore, Maryland 21201, MD, United States
| | - Selen C Muratoglu
- Center for Vascular and Inflammatory Diseases, Biopark I, R213, 800 W. Baltimore Street, Baltimore, Maryland 21201, MD, United States.,Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, MD, United States
| | - Dudley K Strickland
- Center for Vascular and Inflammatory Diseases, Biopark I, R213, 800 W. Baltimore Street, Baltimore, Maryland 21201, MD, United States.,Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, MD, United States.,Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland 21201, MD, United States
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11
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Design, synthesis, and biological evaluation of radioiodinated benzo[d]imidazole-quinoline derivatives for platelet-derived growth factor receptor β (PDGFRβ) imaging. Bioorg Med Chem 2019; 27:383-393. [DOI: 10.1016/j.bmc.2018.12.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 12/07/2018] [Accepted: 12/10/2018] [Indexed: 12/17/2022]
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12
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Au DT, Migliorini M, Strickland DK, Muratoglu SC. Macrophage LRP1 Promotes Diet-Induced Hepatic Inflammation and Metabolic Dysfunction by Modulating Wnt Signaling. Mediators Inflamm 2018; 2018:7902841. [PMID: 30524198 PMCID: PMC6247401 DOI: 10.1155/2018/7902841] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 08/22/2018] [Accepted: 09/03/2018] [Indexed: 12/20/2022] Open
Abstract
Hepatic inflammation is associated with the development of insulin resistance, which can perpetuate the disease state and may increase the risk of metabolic syndrome and diabetes. Despite recent advances, mechanisms linking hepatic inflammation and insulin resistance are still unclear. The low-density lipoprotein receptor-related protein 1 (LRP1) is a large endocytic and signaling receptor that is highly expressed in macrophages, adipocytes, hepatocytes, and vascular smooth muscle cells. To investigate the potential role of macrophage LRP1 in hepatic inflammation and insulin resistance, we conducted experiments using macrophage-specific LRP1-deficient mice (macLRP1-/- ) generated on a low-density lipoprotein receptor knockout (LDLR-/- ) background and fed a Western diet. LDLR-/-; macLRP1-/- mice gained less body weight and had improved glucose tolerance compared to LDLR-/- mice. Livers from LDLR-/-; macLRP1-/- mice displayed lower levels of gene expression for several inflammatory cytokines, including Ccl3, Ccl4, Ccl8, Ccr1, Ccr2, Cxcl9, and Tnf, and reduced phosphorylation of GSK3α and p38 MAPK proteins. Furthermore, LRP1-deficient peritoneal macrophages displayed altered cholesterol metabolism. Finally, circulating levels of sFRP-5, a potent anti-inflammatory adipokine that functions as a decoy receptor for Wnt5a, were elevated in LDLR-/-; macLRP1-/- mice. Surface plasmon resonance experiments revealed that sFRP-5 is a novel high affinity ligand for LRP1, revealing that LRP1 regulates levels of this inhibitor of Wnt5a-mediated signaling. Collectively, our results suggest that LRP1 expression in macrophages promotes hepatic inflammation and the development of glucose intolerance and insulin resistance by modulating Wnt signaling.
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Affiliation(s)
- Dianaly T. Au
- Center for Vascular and Inflammatory Diseases, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Mary Migliorini
- Center for Vascular and Inflammatory Diseases, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Dudley K. Strickland
- Center for Vascular and Inflammatory Diseases, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Selen C. Muratoglu
- Center for Vascular and Inflammatory Diseases, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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13
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Gong X, Guo X, Huang R, Liao H, Zhang Q, Yan J, Luo L, Zhang Q, Qiu A, Sun Y, Liang X. Expression of ILK in renal stroma is essential for multiple aspects of renal development. Am J Physiol Renal Physiol 2018; 315:F374-F385. [PMID: 29638158 DOI: 10.1152/ajprenal.00509.2017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Kidney development involves reciprocal and inductive interactions between the ureteric bud (UB) and surrounding metanephric mesenchyme. Signals from renal stromal lineages are essential for differentiation and patterning of renal epithelial and mesenchymal cell types and renal vasculogenesis; however, underlying mechanisms remain not fully understood. Integrin-linked kinase (ILK), a key component of integrin signaling pathway, plays an important role in kidney development. However, the role of ILK in renal stroma remains unknown. Here, we ablated ILK in renal stromal lineages using a platelet-derived growth factor receptor B ( Pdgfrb) -Cre mouse line, and the resulting Ilk mutant mice presented postnatal growth retardation and died within 3 wk of age with severe renal developmental defects. Pdgfrb-Cre;Ilk mutant kidneys exhibited a significant decrease in UB branching and disrupted collecting duct formation. From E16.5 onward, renal interstitium was disorganized, forming medullary interstitial pseudocysts. Pdgfrb-Cre;Ilk mutants exhibited renal vasculature mispatterning and impaired glomerular vascular differentiation. Impaired glial cell-derived neurotrophic factor/Ret and bone morphogenetic protein 7 signaling pathways were observed in Pdgfrb-Cre;Ilk mutant kidneys. Furthermore, phosphoproteomic and Western blot analyses revealed a significant dysregulation of a number of key signaling pathways required for kidney morphogenesis, including PI3K/AKT and MAPK/ERK in Pdgfrb-Cre;Ilk mutants. Our results revealed a critical requirement for ILK in renal-stromal and vascular development, as well as a noncell autonomous role of ILK in UB branching morphogenesis.
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Affiliation(s)
- Xiaohui Gong
- Key Laboratory of Arrhythmia, Ministry of Education, East Hospital, School of Medicine, Tongji University , Shanghai , China
| | - Xiaoxia Guo
- Key Laboratory of Arrhythmia, Ministry of Education, East Hospital, School of Medicine, Tongji University , Shanghai , China
| | - Ru Huang
- Key Laboratory of Arrhythmia, Ministry of Education, East Hospital, School of Medicine, Tongji University , Shanghai , China
| | - Huimin Liao
- Key Laboratory of Arrhythmia, Ministry of Education, East Hospital, School of Medicine, Tongji University , Shanghai , China
| | - Qingquan Zhang
- Key Laboratory of Arrhythmia, Ministry of Education, East Hospital, School of Medicine, Tongji University , Shanghai , China
| | - Jie Yan
- Key Laboratory of Arrhythmia, Ministry of Education, East Hospital, School of Medicine, Tongji University , Shanghai , China
| | - Lina Luo
- Key Laboratory of Arrhythmia, Ministry of Education, East Hospital, School of Medicine, Tongji University , Shanghai , China
| | - Qitong Zhang
- Key Laboratory of Arrhythmia, Ministry of Education, East Hospital, School of Medicine, Tongji University , Shanghai , China
| | - Andong Qiu
- School of Life Sciences and Technology, Tongji University , Shanghai , China
| | - Yunfu Sun
- Key Laboratory of Arrhythmia, Ministry of Education, East Hospital, School of Medicine, Tongji University , Shanghai , China
| | - Xingqun Liang
- Key Laboratory of Arrhythmia, Ministry of Education, East Hospital, School of Medicine, Tongji University , Shanghai , China
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14
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Iyer VV, Priya PY, Kangeyavelu J. Effects of increased accumulation of doxorubicin due to emodin on efflux transporter and LRP1 expression in lung adenocarcinoma and colorectal carcinoma cells. Mol Cell Biochem 2018; 449:91-104. [PMID: 29644529 DOI: 10.1007/s11010-018-3346-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Accepted: 04/05/2018] [Indexed: 11/28/2022]
Abstract
Treatment with doxorubicin (dox) and emodin, separately and together, under normoxic and hypoxia-like conditions induced by CoCl2, led to greater intracellular compound accumulation over 10 h post-addition in the presence of CoCl2 in lung adenocarcinoma (A549) and colorectal carcinoma (HCT-15) cell lines. Confocal microscopy revealed that emodin, by itself, showed high cytosolic distribution in both cell lines, at 40 min post-addition but had entered the nuclei by 2 h, while dox entered the nuclei by 40 min. Both compounds modulated the expression of the efflux transporters (PgP, ABCG2, or MRP1-4) and the endocytic receptor, low-density lipoprotein receptor-related protein 1 (LRP1), to different extents under the study conditions. Efflux transporter upregulation was linked to lower intracellular compound levels due to greater efflux. Increased dox accumulation was accompanied by unaltered expression or upregulation of LRP1 in A549 cells. In both cell lines, increased accumulation of dox and emodin was observed whenever LRP1 and the efflux transporters known to transport dox and emodin were all up- or downregulated concomitantly. Increased growth inhibition was linked to co-treatment with dox and emodin and with increased ligand accumulation. The results presented in this study raise the hypothesis that higher production of LRP1 protein may be associated with higher endocytosis of upregulated transporter proteins at the cell surface, and hence, increased dox and emodin accumulation and growth inhibition. If so, elevation of LRP1 expression may be a useful target for interventions to promote the efficacy of these and other anticancer drugs.
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Affiliation(s)
- Vidhya V Iyer
- School of Biosciences and Technology, Vellore Institute of Technology, Vellore, Tamil Nadu, 632 014, India.
- Department of Chemical Engineering, Indian Institute of Technology Bombay Powai, Mumbai, Maharashtra, 400076, India.
| | - P Yoga Priya
- School of Biosciences and Technology, Vellore Institute of Technology, Vellore, Tamil Nadu, 632 014, India
- , Madurai, India
| | - Jeipreeti Kangeyavelu
- School of Biosciences and Technology, Vellore Institute of Technology, Vellore, Tamil Nadu, 632 014, India
- , Chennai, India
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15
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Abstract
Extracellular heat shock proteins (HSP) play important roles in cell signaling and immunity. Many of these effects are mediated by surface receptors expressed on a wide range of cell types. We have investigated the nature of such proteins by cloning candidate receptors into cells (CHO-K1) with the rare property of being null for HSP binding. Using this approach we have discovered that Hsp70 binds avidly to at least two classes of receptors including: (1) c-type lectin receptors (CLR) and (2) scavenger receptors (SR). However, the structural nature of the receptor-ligand interactions is not clear at this time. Hsp70 can bind to LOX-1 (a member of both the CLR and SR), with the c-type lectin binding domain (CTLD) as well as the SR family members SREC-I and FEEL-1/CLEVER-1/STABILIN-1, which by contrast have arrays of EGF-like repeats in their extracellular domains. In this chapter we will discuss: (1) methods for discovery of HSP receptors, (2) approaches to the study of individual receptors in cells that contain multiple such receptors, and (3) methods for investigating HSP receptor function in vivo.
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16
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Platelet-derived growth factor-C and -D in the cardiovascular system and diseases. Mol Aspects Med 2017; 62:12-21. [PMID: 28965749 DOI: 10.1016/j.mam.2017.09.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 09/26/2017] [Indexed: 12/31/2022]
Abstract
The cardiovascular system is among the first organs formed during development and is pivotal for the formation and function of the rest of the organs and tissues. Therefore, the function and homeostasis of the cardiovascular system are finely regulated by many important molecules. Extensive studies have shown that platelet-derived growth factors (PDGFs) and their receptors are critical regulators of the cardiovascular system. Even though PDGF-C and PDGF-D are relatively new members of the PDGF family, their critical roles in the cardiovascular system as angiogenic and survival factors have been amply demonstrated. Understanding the functions of PDGF-C and PDGF-D and the signaling pathways involved may provide novel insights into both basic biomedical research and new therapeutic possibilities for the treatment of cardiovascular diseases.
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17
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Auderset L, Cullen CL, Young KM. Low Density Lipoprotein-Receptor Related Protein 1 Is Differentially Expressed by Neuronal and Glial Populations in the Developing and Mature Mouse Central Nervous System. PLoS One 2016; 11:e0155878. [PMID: 27280679 PMCID: PMC4900551 DOI: 10.1371/journal.pone.0155878] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 05/05/2016] [Indexed: 11/19/2022] Open
Abstract
The low density lipoprotein-receptor related protein 1 (LRP1) is a large endocytic cell surface receptor that is known to interact with a variety of ligands, intracellular adaptor proteins and other cell surface receptors to regulate cellular behaviours ranging from proliferation to cell fate specification, migration, axon guidance, and lipid metabolism. A number of studies have demonstrated that LRP1 is expressed in the brain, yet it is unclear which central nervous system cell types express LRP1 during development and in adulthood. Herein we undertake a detailed study of LRP1 expression within the mouse brain and spinal cord, examining a number of developmental stages ranging from embryonic day 13.5 to postnatal day 60. We report that LRP1 expression in the brain peaks during postnatal development. On a cellular level, LRP1 is expressed by radial glia, neuroblasts, microglia, oligodendrocyte progenitor cells (OPCs), astrocytes and neurons, with the exception of parvalbumin+ interneurons in the cortex. Most cell populations exhibit stable expression of LRP1 throughout development; however, the proportion of OPCs that express LRP1 increases significantly from ~69% at E15.5 to ~99% in adulthood. We also report that LRP1 expression is rapidly lost as OPCs differentiate, and is absent from all oligodendrocytes, including newborn oligodendrocytes. While LRP1 function has been primarily examined in mature neurons, these expression data suggest it plays a more critical role in glial cell regulation-where expression levels are much higher.
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Affiliation(s)
- Loic Auderset
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, 7000, Australia
| | - Carlie L. Cullen
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, 7000, Australia
| | - Kaylene M. Young
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, 7000, Australia
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18
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Jiang Q, Lu W, Yang K, Hadadi C, Fu X, Chen Y, Yun X, Zhang J, Li M, Xu L, Tang H, Yuan JXJ, Wang J, Sun D. Sodium tanshinone IIA sulfonate inhibits hypoxia-induced enhancement of SOCE in pulmonary arterial smooth muscle cells via the PKG-PPAR-γ signaling axis. Am J Physiol Cell Physiol 2016; 311:C136-49. [PMID: 27194472 PMCID: PMC4967135 DOI: 10.1152/ajpcell.00252.2015] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 05/02/2016] [Indexed: 11/22/2022]
Abstract
Our laboratory previously showed that sodium tanshinone IIA sulfonate (STS) inhibited store-operated Ca(2+) entry (SOCE) through store-operated Ca(2+) channels (SOCC) via downregulating the expression of transient receptor potential canonical proteins (TRPC), which contribute to the formation of SOCC (Wang J, Jiang Q, Wan L, Yang K, Zhang Y, Chen Y, Wang E, Lai N, Zhao L, Jiang H, Sun Y, Zhong N, Ran P, Lu W. Am J Respir Cell Mol Biol 48: 125-134, 2013). The detailed molecular mechanisms by which STS inhibits SOCE and downregulates TRPC, however, remain largely unknown. We have previously shown that, under hypoxic conditions, inhibition of protein kinase G (PKG) and peroxisome proliferator-activated receptor-γ (PPAR-γ) signaling axis results in the upregulation of TRPC (Wang J, Yang K, Xu L, Zhang Y, Lai N, Jiang H, Zhang Y, Zhong N, Ran P, Lu W. Am J Respir Cell Mol Biol 49: 231-240, 2013). This suggests that strategies targeting the restoration of this signaling pathway may be an effective treatment strategy for pulmonary hypertension. In this study, our results demonstrated that STS treatment can effectively prevent the hypoxia-mediated inhibition of the PKG-PPAR-γ signaling axis in rat distal pulmonary arterial smooth muscle cells (PASMCs) and distal pulmonary arteries. These effects of STS treatment were blocked by pharmacological inhibition or specific small interfering RNA knockdown of either PKG or PPAR-γ. Moreover, targeted PPAR-γ agonist markedly enhanced the beneficial effects of STS. These results comprehensively suggest that STS treatment can prevent hypoxia-mediated increases in intracellular calcium homeostasis and cell proliferation, by targeting and restoring the hypoxia-inhibited PKG-PPAR-γ signaling pathway in PASMCs.
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Affiliation(s)
- Qian Jiang
- State Key Laboratory of Respiratory Diseases, Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Wenju Lu
- State Key Laboratory of Respiratory Diseases, Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Kai Yang
- State Key Laboratory of Respiratory Diseases, Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Cyrus Hadadi
- Department of Cardiology, Geisinger Medical Center, Danville, Pennsylvania
| | - Xin Fu
- State Key Laboratory of Respiratory Diseases, Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Yuqin Chen
- State Key Laboratory of Respiratory Diseases, Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Xin Yun
- State Key Laboratory of Respiratory Diseases, Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Jie Zhang
- State Key Laboratory of Respiratory Diseases, Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Meichan Li
- State Key Laboratory of Respiratory Diseases, Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Lei Xu
- Department of Respiratory Diseases, The Affiliated Hospital of Inner Mongolia Medical University Hohhot, Inner Mongolia, China; and
| | - Haiyang Tang
- Division of Translational and Regenerative Medicine, Department of Medicine, The University of Arizona, Tucson, Arizona
| | - Jason X-J Yuan
- Division of Translational and Regenerative Medicine, Department of Medicine, The University of Arizona, Tucson, Arizona
| | - Jian Wang
- State Key Laboratory of Respiratory Diseases, Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China; Division of Translational and Regenerative Medicine, Department of Medicine, The University of Arizona, Tucson, Arizona; Division of Pulmonary Medicine, The People's Hospital of Inner Mongolia, Hohhot, Inner Mongolia, China;
| | - Dejun Sun
- Division of Pulmonary Medicine, The People's Hospital of Inner Mongolia, Hohhot, Inner Mongolia, China
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19
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Belotti D, Capelli C, Resovi A, Introna M, Taraboletti G. Thrombospondin-1 promotes mesenchymal stromal cell functions via TGFβ and in cooperation with PDGF. Matrix Biol 2016; 55:106-116. [PMID: 26992552 DOI: 10.1016/j.matbio.2016.03.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 03/04/2016] [Accepted: 03/07/2016] [Indexed: 10/22/2022]
Abstract
Mesenchymal stromal cells (MSC) are characterized by unique tropism for wounded tissues, high differentiating capacity, ability to induce tissue repair, and anti-inflammatory and immunoregulatory activities. This has generated interest in their therapeutic use in severe human conditions as well as in regenerative medicine and tissue engineering. Identification of factors involved in the regulation of MSC proliferation, migration and differentiation could provide insights into the pathophysiological regulation of MSC and be exploited to optimize clinical grade expansion protocols for therapeutic use. Here we identify thrombospondin-1 (TSP-1) as a major regulator of MSC. TSP-1 induced MSC proliferation. This effect was mediated by TSP-1-induced activation of endogenous TGFβ, as shown by the inhibitory effects of anti-TGFβ antibodies and by the lack of activity of TSP-2 - that does not activate TGFβ. Moreover, TSP-1 strongly potentiated the proliferative and migratory activity of PDGF on MSC. TSP-1 directly bound to PDGF, through a site located within the TSP-1 type III repeats, and protected the growth factor from degradation by MSC-derived proteases, hence increasing its stability and bioavailability. The studies presented here identify a more comprehensive picture of the pleiotropic effect of TSP-1 on MSC behavior, setting the basis for further studies aimed at investigating the possible use of PDGF and TSP-1 in the in vitro expansion of MSC for therapeutic applications.
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Affiliation(s)
- Dorina Belotti
- Tumor Angiogenesis Unit, Department of Oncology, IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Bergamo, Italy
| | - Chiara Capelli
- USS Centro di Terapia Cellulare "G. Lanzani", USC Haematology, ASST Ospedale Papa Giovanni XXIII, Bergamo, Italy
| | - Andrea Resovi
- Tumor Angiogenesis Unit, Department of Oncology, IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Bergamo, Italy
| | - Martino Introna
- USS Centro di Terapia Cellulare "G. Lanzani", USC Haematology, ASST Ospedale Papa Giovanni XXIII, Bergamo, Italy
| | - Giulia Taraboletti
- Tumor Angiogenesis Unit, Department of Oncology, IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Bergamo, Italy.
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20
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Low Density Lipoprotein Receptor Related Proteins as Regulators of Neural Stem and Progenitor Cell Function. Stem Cells Int 2016; 2016:2108495. [PMID: 26949399 PMCID: PMC4754494 DOI: 10.1155/2016/2108495] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 11/24/2015] [Accepted: 01/06/2016] [Indexed: 12/20/2022] Open
Abstract
The central nervous system (CNS) is a highly organised structure. Many signalling systems work in concert to ensure that neural stem cells are appropriately directed to generate progenitor cells, which in turn mature into functional cell types including projection neurons, interneurons, astrocytes, and oligodendrocytes. Herein we explore the role of the low density lipoprotein (LDL) receptor family, in particular family members LRP1 and LRP2, in regulating the behaviour of neural stem and progenitor cells during development and adulthood. The ability of LRP1 and LRP2 to bind a diverse and extensive range of ligands, regulate ligand endocytosis, recruit nonreceptor tyrosine kinases for direct signal transduction and signal in conjunction with other receptors, enables them to modulate many crucial neural cell functions.
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21
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Van Gool B, Dedieu S, Emonard H, Roebroek AJM. The Matricellular Receptor LRP1 Forms an Interface for Signaling and Endocytosis in Modulation of the Extracellular Tumor Environment. Front Pharmacol 2015; 6:271. [PMID: 26617523 PMCID: PMC4639618 DOI: 10.3389/fphar.2015.00271] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 10/29/2015] [Indexed: 12/19/2022] Open
Abstract
The membrane protein low-density lipoprotein receptor related-protein 1 (LRP1) has been attributed a role in cancer. However, its presumably often indirect involvement is far from understood. LRP1 has both endocytic and signaling activities. As a matricellular receptor it is involved in regulation, mostly by clearing, of various extracellular matrix degrading enzymes including matrix metalloproteinases, serine proteases, protease inhibitor complexes, and the endoglycosidase heparanase. Furthermore, by binding extracellular ligands including growth factors and subsequent intracellular interaction with scaffolding and adaptor proteins it is involved in regulation of various signaling cascades. LRP1 expression levels are often downregulated in cancer and some studies consider low LRP1 levels a poor prognostic factor. On the contrary, upregulation in brain cancers has been noted and clinical trials explore the use of LRP1 as cargo receptor to deliver cytotoxic agents. This mini-review focuses on LRP1's role in tumor growth and metastasis especially by modulation of the extracellular tumor environment. In relation to this role its diagnostic, prognostic and therapeutic potential will be discussed.
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Affiliation(s)
- Bart Van Gool
- Laboratory for Experimental Mouse Genetics, Department of Human Genetics , KU Leuven, Leuven, Belgium
| | - Stéphane Dedieu
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7369 Matrice Extracellulaire et Dynamique Cellulaire, Université de Reims Champagne-Ardenne, Unité de Formation et de Recherche Sciences Exactes et Naturelles , Reims, France
| | - Hervé Emonard
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7369 Matrice Extracellulaire et Dynamique Cellulaire, Université de Reims Champagne-Ardenne, Unité de Formation et de Recherche Sciences Exactes et Naturelles , Reims, France
| | - Anton J M Roebroek
- Laboratory for Experimental Mouse Genetics, Department of Human Genetics , KU Leuven, Leuven, Belgium
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22
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Kang LI, Isse K, Koral K, Bowen WC, Muratoglu S, Strickland DK, Michalopoulos GK, Mars WM. Tissue-type plasminogen activator suppresses activated stellate cells through low-density lipoprotein receptor-related protein 1. J Transl Med 2015; 95:1117-29. [PMID: 26237273 PMCID: PMC4586397 DOI: 10.1038/labinvest.2015.94] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Revised: 05/28/2015] [Accepted: 06/20/2015] [Indexed: 12/21/2022] Open
Abstract
Hepatic stellate cell (HSC) activation and trans-differentiation into myofibroblast (MFB)-like cells is key for fibrogenesis after liver injury and a potential therapeutic target. Recent studies demonstrated that low-density lipoprotein receptor-related protein 1 (LRP1)-dependent signaling by tissue-type plasminogen activator (t-PA) is a pro-fibrotic regulator of the MFB phenotype in kidney. This study investigated whether LRP1 signaling by t-PA is also relevant to HSC activation following injury. Primary and immortalized rat HSCs were treated with t-PA and assayed by western blot, MTT, and TUNEL. In vitro results were then verified using an in vivo, acute carbon tetrachloride (CCl4) injury model that examined the phenotype and recovery kinetics of MFBs from wild-type animals vs mice with a global (t-PA) or HSC-targeted (LRP1) deletion. In vitro, in contrast to kidney MFBs, exogenous, proteolytically inactive t-PA suppressed, rather than induced, activation markers in HSCs following phosphorylation of LRP1. This process was mediated by LRP1 as inhibition of t-PA binding to LRP1 blocked the effects of t-PA. In vivo, following acute injury, phosphorylation of LRP1 on activated HSCs occurred immediately prior to their disappearance. Mice lacking t-PA or LRP1 retained higher densities of activated HSCs for a longer time period compared with control mice after injury cessation. Hence, t-PA, an FDA-approved drug, contributes to the suppression of activated HSCs following injury repair via signaling through LRP1. This renders t-PA a potential target for exploitation in treating patients with fibrosis.
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Affiliation(s)
- Liang-I Kang
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Kumiko Isse
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Kelly Koral
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - William C Bowen
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Selen Muratoglu
- Center for Vascular and Inflammatory Diseases, University of Maryland School of Medicine, Baltimore, MD, USA,Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Dudley K Strickland
- Center for Vascular and Inflammatory Diseases, University of Maryland School of Medicine, Baltimore, MD, USA,Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, USA,Department of Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | - George K Michalopoulos
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Wendy M Mars
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA,Department of Pathology, University of Pittsburgh School of Medicine, S407 Biomedical Science Tower, 200 Lothrop Street, Pittsburgh, PA 15261, USA. E-mail:
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Lillis AP, Muratoglu SC, Au DT, Migliorini M, Lee MJ, Fried SK, Mikhailenko I, Strickland DK. LDL Receptor-Related Protein-1 (LRP1) Regulates Cholesterol Accumulation in Macrophages. PLoS One 2015; 10:e0128903. [PMID: 26061292 PMCID: PMC4463855 DOI: 10.1371/journal.pone.0128903] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Accepted: 05/03/2015] [Indexed: 11/18/2022] Open
Abstract
Within the circulation, cholesterol is transported by lipoprotein particles and is taken up by cells when these particles associate with cellular receptors. In macrophages, excessive lipoprotein particle uptake leads to foam cell formation, which is an early event in the development of atherosclerosis. Currently, mechanisms responsible for foam cell formation are incompletely understood. To date, several macrophage receptors have been identified that contribute to the uptake of modified forms of lipoproteins leading to foam cell formation, but the in vivo contribution of the LDL receptor-related protein 1 (LRP1) to this process is not known [corrected]. To investigate the role of LRP1 in cholesterol accumulation in macrophages, we generated mice with a selective deletion of LRP1 in macrophages on an LDL receptor (LDLR)-deficient background (macLRP1-/-). After feeding mice a high fat diet for 11 weeks, peritoneal macrophages isolated from Lrp+/+ mice contained significantly higher levels of total cholesterol than those from macLRP1-/- mice. Further analysis revealed that this was due to increased levels of cholesterol esters. Interestingly, macLRP1-/- mice displayed elevated plasma cholesterol and triglyceride levels resulting from accumulation of large, triglyceride-rich lipoprotein particles in the circulation. This increase did not result from an increase in hepatic VLDL biosynthesis, but rather results from a defect in catabolism of triglyceride-rich lipoprotein particles in macLRP1-/- mice. These studies reveal an important in vivo contribution of macrophage LRP1 to cholesterol homeostasis.
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Affiliation(s)
- Anna P. Lillis
- Center for Vascular and Inflammatory Diseases, University of Maryland School of Medicine, Baltimore, MD 21201, United States of America
- Department of Pathology, Duke University Medical Center, Durham, NC 27710, United States of America
| | - Selen Catania Muratoglu
- Center for Vascular and Inflammatory Diseases, University of Maryland School of Medicine, Baltimore, MD 21201, United States of America
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, United States of America
| | - Dianaly T. Au
- Center for Vascular and Inflammatory Diseases, University of Maryland School of Medicine, Baltimore, MD 21201, United States of America
| | - Mary Migliorini
- Center for Vascular and Inflammatory Diseases, University of Maryland School of Medicine, Baltimore, MD 21201, United States of America
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, United States of America
| | - Mi-Jeong Lee
- Department of Medicine, Section of Endocrinology, Diabetes and Nutrition, Boston University School of Medicine, Boston, MA 02118, United States of America
| | - Susan K. Fried
- Department of Medicine, Section of Endocrinology, Diabetes and Nutrition, Boston University School of Medicine, Boston, MA 02118, United States of America
| | - Irina Mikhailenko
- Center for Vascular and Inflammatory Diseases, University of Maryland School of Medicine, Baltimore, MD 21201, United States of America
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, United States of America
| | - Dudley K. Strickland
- Center for Vascular and Inflammatory Diseases, University of Maryland School of Medicine, Baltimore, MD 21201, United States of America
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, United States of America
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, United States of America
- * E-mail:
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24
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Cai Y, Nagel DJ, Zhou Q, Cygnar KD, Zhao H, Li F, Pi X, Knight PA, Yan C. Role of cAMP-phosphodiesterase 1C signaling in regulating growth factor receptor stability, vascular smooth muscle cell growth, migration, and neointimal hyperplasia. Circ Res 2015; 116:1120-32. [PMID: 25608528 DOI: 10.1161/circresaha.116.304408] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
RATIONALE Neointimal hyperplasia characterized by abnormal accumulation of vascular smooth muscle cells (SMCs) is a hallmark of occlusive disorders such as atherosclerosis, postangioplasty restenosis, vein graft stenosis, and allograft vasculopathy. Cyclic nucleotides are vital in SMC proliferation and migration, which are regulated by cyclic nucleotide phosphodiesterases (PDEs). OBJECTIVE Our goal is to understand the regulation and function of PDEs in SMC pathogenesis of vascular diseases. METHODS AND RESULTS We performed screening for genes differentially expressed in normal contractile versus proliferating synthetic SMCs. We observed that PDE1C expression was low in contractile SMCs but drastically elevated in synthetic SMCs in vitro and in various mouse vascular injury models in vivo. In addition, PDE1C was highly induced in neointimal SMCs of human coronary arteries. More importantly, injury-induced neointimal formation was significantly attenuated by PDE1C deficiency or PDE1 inhibition in vivo. PDE1 inhibition suppressed vascular remodeling of human saphenous vein explants ex vivo. In cultured SMCs, PDE1C deficiency or PDE1 inhibition attenuated SMC proliferation and migration. Mechanistic studies revealed that PDE1C plays a critical role in regulating the stability of growth factor receptors, such as PDGF receptor β (PDGFRβ) known to be important in pathological vascular remodeling. PDE1C interacts with low-density lipoprotein receptor-related protein-1 and PDGFRβ, thus regulating PDGFRβ endocytosis and lysosome-dependent degradation in an low-density lipoprotein receptor-related protein-1-dependent manner. A transmembrane adenylyl cyclase cAMP-dependent protein kinase cascade modulated by PDE1C is critical in regulating PDGFRβ degradation. CONCLUSIONS These findings demonstrated that PDE1C is an important regulator of SMC proliferation, migration, and neointimal hyperplasia, in part through modulating endosome/lysosome-dependent PDGFRβ protein degradation via low-density lipoprotein receptor-related protein-1.
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Affiliation(s)
- Yujun Cai
- From the Department of Medicine, Aab Cardiovascular Research Institute (Y.C., D.J.N., Q.Z., C.Y.), Department of Pathology and Laboratory Medicine (F.L.), and Department of Surgery (P.A.K.), School of Medicine and Dentistry, University of Rochester, NY; Department of Biology, Johns Hopkins University, Baltimore, MD (K.D.C., H.Z.); and Department of Medicine, Athero and Lipo Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX (X.P.)
| | - David J Nagel
- From the Department of Medicine, Aab Cardiovascular Research Institute (Y.C., D.J.N., Q.Z., C.Y.), Department of Pathology and Laboratory Medicine (F.L.), and Department of Surgery (P.A.K.), School of Medicine and Dentistry, University of Rochester, NY; Department of Biology, Johns Hopkins University, Baltimore, MD (K.D.C., H.Z.); and Department of Medicine, Athero and Lipo Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX (X.P.)
| | - Qian Zhou
- From the Department of Medicine, Aab Cardiovascular Research Institute (Y.C., D.J.N., Q.Z., C.Y.), Department of Pathology and Laboratory Medicine (F.L.), and Department of Surgery (P.A.K.), School of Medicine and Dentistry, University of Rochester, NY; Department of Biology, Johns Hopkins University, Baltimore, MD (K.D.C., H.Z.); and Department of Medicine, Athero and Lipo Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX (X.P.)
| | - Katherine D Cygnar
- From the Department of Medicine, Aab Cardiovascular Research Institute (Y.C., D.J.N., Q.Z., C.Y.), Department of Pathology and Laboratory Medicine (F.L.), and Department of Surgery (P.A.K.), School of Medicine and Dentistry, University of Rochester, NY; Department of Biology, Johns Hopkins University, Baltimore, MD (K.D.C., H.Z.); and Department of Medicine, Athero and Lipo Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX (X.P.)
| | - Haiqing Zhao
- From the Department of Medicine, Aab Cardiovascular Research Institute (Y.C., D.J.N., Q.Z., C.Y.), Department of Pathology and Laboratory Medicine (F.L.), and Department of Surgery (P.A.K.), School of Medicine and Dentistry, University of Rochester, NY; Department of Biology, Johns Hopkins University, Baltimore, MD (K.D.C., H.Z.); and Department of Medicine, Athero and Lipo Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX (X.P.)
| | - Faqian Li
- From the Department of Medicine, Aab Cardiovascular Research Institute (Y.C., D.J.N., Q.Z., C.Y.), Department of Pathology and Laboratory Medicine (F.L.), and Department of Surgery (P.A.K.), School of Medicine and Dentistry, University of Rochester, NY; Department of Biology, Johns Hopkins University, Baltimore, MD (K.D.C., H.Z.); and Department of Medicine, Athero and Lipo Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX (X.P.)
| | - Xinchun Pi
- From the Department of Medicine, Aab Cardiovascular Research Institute (Y.C., D.J.N., Q.Z., C.Y.), Department of Pathology and Laboratory Medicine (F.L.), and Department of Surgery (P.A.K.), School of Medicine and Dentistry, University of Rochester, NY; Department of Biology, Johns Hopkins University, Baltimore, MD (K.D.C., H.Z.); and Department of Medicine, Athero and Lipo Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX (X.P.)
| | - Peter A Knight
- From the Department of Medicine, Aab Cardiovascular Research Institute (Y.C., D.J.N., Q.Z., C.Y.), Department of Pathology and Laboratory Medicine (F.L.), and Department of Surgery (P.A.K.), School of Medicine and Dentistry, University of Rochester, NY; Department of Biology, Johns Hopkins University, Baltimore, MD (K.D.C., H.Z.); and Department of Medicine, Athero and Lipo Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX (X.P.)
| | - Chen Yan
- From the Department of Medicine, Aab Cardiovascular Research Institute (Y.C., D.J.N., Q.Z., C.Y.), Department of Pathology and Laboratory Medicine (F.L.), and Department of Surgery (P.A.K.), School of Medicine and Dentistry, University of Rochester, NY; Department of Biology, Johns Hopkins University, Baltimore, MD (K.D.C., H.Z.); and Department of Medicine, Athero and Lipo Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX (X.P.).
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25
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Tassi R, Baldazzi V, Lapini A, Carini M, Mazzanti R. Hyperlipidemia and hypothyroidism among metastatic renal cell carcinoma patients taking sunitinib malate. Related or unrelated adverse events? Clin Genitourin Cancer 2014; 13:e101-5. [PMID: 25450040 DOI: 10.1016/j.clgc.2014.08.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Revised: 08/11/2014] [Accepted: 08/25/2014] [Indexed: 11/30/2022]
Abstract
BACKGROUND In recent years, new-onset hypothyroidism was extensively reported in patients receiving sunitinib for malignancy. Effects of sunitinib on serum lipids are not described, however a hyperlipidemic state is commonly observed in hypothyroid patients. Here we report about the incidence and severity of hypercholesterolemia and hypertriglyceridemia in a cohort of patients receiving sunitinib for metastatic renal cell carcinoma. PATIENTS AND METHODS Thyroid function tests, serum triglycerides, and cholesterol were prospectively evaluated in 39 consecutive metastatic renal cell carcinoma patients, who were receiving sunitinib as a first-line treatment. Incidence of hyperlipidemia, thyroid function impairment, and their possible relationship were investigated. RESULTS Thyroid function tests, serum cholesterol, and triglycerides were assessed at baseline and before the beginning of each sunitinib cycle. During treatment, median triglyceride levels increased up to 271.3 mg/dL, and median cholesterol increased up to 234.7 mg/dL (+113% and +22%, respectively). A hyperlipidemic state developed in 27 patients (69.2%) within a mean time of 1.8 six-week cycles (range, 1-5 cycles) and persisted during treatment. Hypothyroidism was observed in 20 patients (51.2%) and usually developed within 2.3 cycles. Because hypothyroidism and hyperlipidemia developed at different time points of treatment and among different patients, our results failed to demonstrate a correlation between these adverse events. CONCLUSION New-onset hyperlipidemia was observed in an increased percentage of patients taking sunitinib. The mechanism of this side effect is still unclear. We recommend careful monitoring of serum lipid levels during sunitinib administration to recognize possible consequences, especially on cardiovascular health.
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Affiliation(s)
- Renato Tassi
- Second Medical Oncology Unit and First Urology Unit, Università degli Studi di Firenze, Department of Oncology, Azienda Ospedaliero Universitaria Careggi, Florence, Italy.
| | - Valentina Baldazzi
- Medical Oncology Unit, Department of Oncology, Ospedale Santa Maria Annunziata, Azienda Sanitaria di Firenze, Florence, Italy
| | - Alberto Lapini
- Second Medical Oncology Unit and First Urology Unit, Università degli Studi di Firenze, Department of Oncology, Azienda Ospedaliero Universitaria Careggi, Florence, Italy
| | - Marco Carini
- Second Medical Oncology Unit and First Urology Unit, Università degli Studi di Firenze, Department of Oncology, Azienda Ospedaliero Universitaria Careggi, Florence, Italy
| | - Roberto Mazzanti
- Second Medical Oncology Unit and First Urology Unit, Università degli Studi di Firenze, Department of Oncology, Azienda Ospedaliero Universitaria Careggi, Florence, Italy
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26
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Imatinib mesylate stimulates low-density lipoprotein receptor-related protein 1-mediated ERK phosphorylation in insulin-producing cells. Clin Sci (Lond) 2014; 128:17-28. [DOI: 10.1042/cs20130560] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The PDGF receptor and c-Abl inhibitor imatinib has previously been reported to counteract β-cell death and diabetes. Our findings show that imatinib might promote β-cell survival by enhancing basal LRP1 activity.
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27
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Strickland DK, Au DT, Cunfer P, Muratoglu SC. Low-density lipoprotein receptor-related protein-1: role in the regulation of vascular integrity. Arterioscler Thromb Vasc Biol 2014; 34:487-98. [PMID: 24504736 DOI: 10.1161/atvbaha.113.301924] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Low-density lipoprotein receptor-related protein-1 (LRP1) is a large endocytic and signaling receptor that is widely expressed. In the liver, LRP1 plays an important role in regulating the plasma levels of blood coagulation factor VIII (fVIII) by mediating its uptake and subsequent degradation. fVIII is a key plasma protein that is deficient in hemophilia A and circulates in complex with von Willebrand factor. Because von Willebrand factor blocks binding of fVIII to LRP1, questions remain on the molecular mechanisms by which LRP1 removes fVIII from the circulation. LRP1 also regulates cell surface levels of tissue factor, a component of the extrinsic blood coagulation pathway. This occurs when tissue factor pathway inhibitor bridges the fVII/tissue factor complex to LRP1, resulting in rapid LRP1-mediated internalization and downregulation of coagulant activity. In the vasculature LRP1 also plays protective role from the development of aneurysms. Mice in which the lrp1 gene is selectively deleted in vascular smooth muscle cells develop a phenotype similar to the progression of aneurysm formation in human patient, revealing that these mice are ideal for investigating molecular mechanisms associated with aneurysm formation. Studies suggest that LRP1 protects against elastin fiber fragmentation by reducing excess protease activity in the vessel wall. These proteases include high-temperature requirement factor A1, matrix metalloproteinase 2, matrix metalloproteinase-9, and membrane associated type 1-matrix metalloproteinase. In addition, LRP1 regulates matrix deposition, in part, by modulating levels of connective tissue growth factor. Defining pathways modulated by LRP1 that lead to aneurysm formation and defining its role in thrombosis may allow for more effective intervention in patients.
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Affiliation(s)
- Dudley K Strickland
- From the Center for Vascular and Inflammatory Disease (D.K.S., D.T.A., P.C., S.C.M.), Departments of Surgery (D.K.S.), and Physiology (S.C.M.), University of Maryland School of Medicine, Baltimore
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Heldin CH. Targeting the PDGF signaling pathway in tumor treatment. Cell Commun Signal 2013; 11:97. [PMID: 24359404 PMCID: PMC3878225 DOI: 10.1186/1478-811x-11-97] [Citation(s) in RCA: 343] [Impact Index Per Article: 31.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Accepted: 12/11/2013] [Indexed: 01/15/2023] Open
Abstract
Platelet-derived growth factor (PDGF) isoforms and PDGF receptors have important functions in the regulation of growth and survival of certain cell types during embryonal development and e.g. tissue repair in the adult. Overactivity of PDGF receptor signaling, by overexpression or mutational events, may drive tumor cell growth. In addition, pericytes of the vasculature and fibroblasts and myofibroblasts of the stroma of solid tumors express PDGF receptors, and PDGF stimulation of such cells promotes tumorigenesis. Inhibition of PDGF receptor signaling has proven to useful for the treatment of patients with certain rare tumors. Whether treatment with PDGF/PDGF receptor antagonists will be beneficial for more common malignancies is the subject for ongoing studies.
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Affiliation(s)
- Carl-Henrik Heldin
- Ludwig Institute for Cancer Research, Science for life laboratory, Uppsala University, Box 595SE-751 24 Uppsala, Sweden.
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29
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Tajsic T, Morrell NW. Smooth muscle cell hypertrophy, proliferation, migration and apoptosis in pulmonary hypertension. Compr Physiol 2013; 1:295-317. [PMID: 23737174 DOI: 10.1002/cphy.c100026] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Pulmonary hypertension is a multifactorial disease characterized by sustained elevation of pulmonary vascular resistance (PVR) and pulmonary arterial pressure (PAP). Central to the pathobiology of this disease is the process of vascular remodelling. This process involves structural and functional changes to the normal architecture of the walls of pulmonary arteries (PAs) that lead to increased muscularization of the muscular PAs, muscularization of the peripheral, previously nonmuscular, arteries of the respiratory acinus, formation of neointima, and formation of plexiform lesions. Underlying or contributing to the development of these lesions is hypertrophy, proliferation, migration, and resistance to apoptosis of medial cells and this article is concerned with the cellular and molecular mechanisms of these processes. In the first part of the article we focus on the concept of smooth muscle cell phenotype and the difficulties surrounding the identification and characterization of the cell/cells involved in the remodelling of the vessel media and we review the general mechanisms of cell hypertrophy, proliferation, migration and apoptosis. Then, in the larger part of the article, we review the factors identified thus far to be involved in PH intiation and/or progression and review and discuss their effects on pulmonary artery smooth muscle cells (PASMCs) the predominant cells in the tunica media of PAs.
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Affiliation(s)
- Tamara Tajsic
- Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, United Kingdom
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30
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Abstract
At least 468 individual genes have been manipulated by molecular methods to study their effects on the initiation, promotion, and progression of atherosclerosis. Most clinicians and many investigators, even in related disciplines, find many of these genes and the related pathways entirely foreign. Medical schools generally do not attempt to incorporate the relevant molecular biology into their curriculum. A number of key signaling pathways are highly relevant to atherogenesis and are presented to provide a context for the gene manipulations summarized herein. The pathways include the following: the insulin receptor (and other receptor tyrosine kinases); Ras and MAPK activation; TNF-α and related family members leading to activation of NF-κB; effects of reactive oxygen species (ROS) on signaling; endothelial adaptations to flow including G protein-coupled receptor (GPCR) and integrin-related signaling; activation of endothelial and other cells by modified lipoproteins; purinergic signaling; control of leukocyte adhesion to endothelium, migration, and further activation; foam cell formation; and macrophage and vascular smooth muscle cell signaling related to proliferation, efferocytosis, and apoptosis. This review is intended primarily as an introduction to these key signaling pathways. They have become the focus of modern atherosclerosis research and will undoubtedly provide a rich resource for future innovation toward intervention and prevention of the number one cause of death in the modern world.
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Affiliation(s)
- Paul N Hopkins
- Cardiovascular Genetics, Department of Internal Medicine, University of Utah, Salt Lake City, Utah, USA.
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31
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Gonias SL, Campana WM. LDL receptor-related protein-1: a regulator of inflammation in atherosclerosis, cancer, and injury to the nervous system. THE AMERICAN JOURNAL OF PATHOLOGY 2013; 184:18-27. [PMID: 24128688 DOI: 10.1016/j.ajpath.2013.08.029] [Citation(s) in RCA: 139] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Revised: 07/31/2013] [Accepted: 08/02/2013] [Indexed: 12/19/2022]
Abstract
Low-density lipoprotein receptor-related protein-1 (LRP1) is an endocytic receptor for numerous proteins that are both structurally and functionally diverse. In some cell types, LRP1-mediated endocytosis is coupled to activation of cell signaling. LRP1 also regulates the composition of the plasma membrane and may, thereby, indirectly regulate the activity of other cell-signaling receptors. Given the scope of LRP1 ligands and its multifunctional nature, it is not surprising that numerous biological activities have been attributed to this receptor. LRP1 gene deletion is embryonic-lethal in mice. However, elegant studies using Cre-LoxP recombination have helped elucidate the function of LRP1 in mature normal and pathological tissues. One major theme that has emerged is the role of LRP1 as a regulator of inflammation. In this review, we will describe evidence for LRP1 as a regulator of inflammation in atherosclerosis, cancer, and injury to the nervous system.
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Affiliation(s)
- Steven L Gonias
- Department of Pathology, University of California School of Medicine, La Jolla, California.
| | - W Marie Campana
- Department of Anesthesiology, University of California School of Medicine, La Jolla, California; Program in Neuroscience, University of California School of Medicine, La Jolla, California
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32
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Wang J, Yang K, Xu L, Zhang Y, Lai N, Jiang H, Zhang Y, Zhong N, Ran P, Lu W. Sildenafil inhibits hypoxia-induced transient receptor potential canonical protein expression in pulmonary arterial smooth muscle via cGMP-PKG-PPARγ axis. Am J Respir Cell Mol Biol 2013; 49:231-40. [PMID: 23526219 DOI: 10.1165/rcmb.2012-0185oc] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Transient receptor potential canonical (TRPC) proteins play important roles in chronically hypoxic pulmonary hypertension (CHPH). Previous results indicated that sildenafil inhibited TRPC1 and TRPC6 expression in rat distal pulmonary arteries (PAs). However, the underlying mechanisms remain unknown. We undertook this study to investigate the downstream signaling of sildenafil's regulation on TRPC1 and TRPC6 expression in pulmonary arterial smooth muscle cells (PASMCs). Hypoxia-exposed rats (10% O2 for 21 d) and rat distal PASMCs (4% O2 for 60 h) were taken as models to mimic CHPH. Real-time PCR, Western blotting, and Fura-2-based fluorescent microscopy were performed for mRNA, protein, and Ca(2+) measurements, respectively. The cellular cyclic guanosine monophosphate (cGMP) analogue 8-(4-chlorophenylthio)-guanosine 3',5'-cyclic monophosphate sodium salt (CPT-cGMP) (100 μM) inhibited TRPC1 and TRPC6 expression, store-operated Ca(2+) entry (SOCE), and the proliferation and migration of PASMCs exposed to prolonged hypoxia. The inhibition of CPT-cGMP on TRPC1 and TRPC6 expression in PASMCs was relieved by either the inhibition or knockdown of cGMP-dependent protein kinase (PKG) and peroxisome proliferator-activated receptor γ (PPARγ) expression. Under hypoxic conditions, CPT-cGMP increased PPARγ expression. This increase was abolished by the PKG antagonists Rp8 or KT5823. PPARγ agonist GW1929 significantly decreased TRPC1 and TRPC6 expression in PASMCs. Moreover, hypoxia exposure decreased, whereas sildenafil treatment increased, PKG and PPARγ expression in PASMCs ex vivo, and in rat distal PAs in vivo. The suppressive effects of sildenafil on TRPC1 and TRPC6 in rat distal PAs and on the hemodynamic parameters of CHPH were inhibited by treatment with the PPARγ antagonist T0070907. We conclude that sildenafil inhibits TRPC1 and TRPC6 expression in PASMCs via cGMP-PKG-PPARγ-dependent signaling during CHPH.
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Affiliation(s)
- Jian Wang
- State Key Laboratory of Respiratory Diseases, Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital, Guangzhou Medical University, Guangzhou, Guangdong, China
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Craig J, Mikhailenko I, Noyes N, Migliorini M, Strickland DK. The LDL receptor-related protein 1 (LRP1) regulates the PDGF signaling pathway by binding the protein phosphatase SHP-2 and modulating SHP-2- mediated PDGF signaling events. PLoS One 2013; 8:e70432. [PMID: 23922991 PMCID: PMC3724782 DOI: 10.1371/journal.pone.0070432] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Accepted: 06/18/2013] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND The PDGF signaling pathway plays a major role in several biological systems, including vascular remodeling that occurs following percutaneous transluminal coronary angioplasty. Recent studies have shown that the LDL receptor-related protein 1 (LRP1) is a physiological regulator of the PDGF signaling pathway. The underlying mechanistic details of how this regulation occurs have yet to be resolved. Activation of the PDGF receptor β (PDGFRβ) leads to tyrosine phosphorylation of the LRP1 cytoplasmic domain within endosomes and generates an LRP1 molecule with increased affinity for adaptor proteins such as SHP-2 that are involved in signaling pathways. SHP-2 is a protein tyrosine phosphatase that positively regulates the PDGFRβ pathway, and is required for PDGF-mediated chemotaxis. We investigated the possibility that LRP1 may regulate the PDGFRβ signaling pathway by binding SHP-2 and competing with the PDGFRβ for this molecule. METHODOLOGY/PRINCIPAL FINDINGS To quantify the interaction between SHP-2 and phosphorylated forms of the LRP1 intracellular domain, we utilized an ELISA with purified recombinant proteins. These studies revealed high affinity binding of SHP-2 to phosphorylated forms of both LRP1 intracellular domain and the PDGFRβ kinase domain. By employing the well characterized dynamin inhibitor, dynasore, we established that PDGF-induced SHP-2 phosphorylation primarily occurs within endosomal compartments, the same compartments in which LRP1 is tyrosine phosphorylated by activated PDGFRβ. Immunofluorescence studies revealed colocalization of LRP1 and phospho-SHP-2 following PDGF stimulation of fibroblasts. To define the contribution of LRP1 to SHP-2-mediated PDGF chemotaxis, we employed fibroblasts expressing LRP1 and deficient in LRP1 and a specific SHP-2 inhibitor, NSC-87877. Our results reveal that LRP1 modulates SHP-2-mediated PDGF-mediated chemotaxis. CONCLUSIONS/SIGNIFICANCE Our data demonstrate that phosphorylated forms of LRP1 and PDGFRβ compete for SHP-2 binding, and that expression of LRP1 attenuates SHP-2-mediated PDGF signaling events.
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Affiliation(s)
- Julie Craig
- Center for Vascular and Inflammatory Diseases and
| | - Irina Mikhailenko
- Center for Vascular and Inflammatory Diseases and
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | | | - Mary Migliorini
- Center for Vascular and Inflammatory Diseases and
- Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Dudley K. Strickland
- Center for Vascular and Inflammatory Diseases and
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
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Masaldan S, Iyer VV. Exploration of effects of emodin in selected cancer cell lines: enhanced growth inhibition by ascorbic acid and regulation of LRP1 and AR under hypoxia-like conditions. J Appl Toxicol 2012; 34:95-104. [PMID: 23212659 DOI: 10.1002/jat.2838] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2012] [Revised: 09/22/2012] [Accepted: 10/03/2012] [Indexed: 12/25/2022]
Abstract
This study explores the link between the antiproliferative activity of emodin through the generation of reactive oxygen species (ROS) in various cancer cell lines and the expression of the androgen receptor (AR) in the prostate cancer cell lines LNCaP (androgen-sensitive) and PC-3 (androgen-refractory), as well as the pro-metastatic low-density lipoprotein receptor-related protein 1 (LRP1) in the above prostate cancer cells and the nonprostate cell lines A549 (lung), HCT-15 (colon) and MG-63 (bone) under normoxic and hypoxia-like conditions. Among all cell lines, emodin showed most growth inhibition in LNCaP, followed by A549. The mechanism of cytotoxicity of emodin was postulated to be the widely reported ROS generation, based on the observations of poor in vitro radical-scavenging activity and increased growth inhibition of emodin by ascorbic acid (AA) pre-treatment owing to the additive effects of ROS generation by emodin and pro-oxidant effects of AA. Emodin downregulated AR in LNCaP under normoxic and hypoxia-like conditions (simulated by CoCl(2)) and LRP1 under normoxia. Emodin upregulated LRP1 in other cell lines, except HCT-15, under normoxic, and even more markedly under hypoxia-like conditions. The downregulation of AR in LNCaP and upregulation of LRP1 in all cell lines, except HCT-15, under hypoxia-like conditions along with growth inhibition by emodin, suggests that emodin may be a useful therapeutic option against androgen-sensitive prostate cancer and other such LRP1-expressing cancers to attempt the targeting of the elevated LRP1 levels to allow the uptake of emodin and/or any other accompanying therapeutic agents by LRP1.
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Affiliation(s)
- Shashank Masaldan
- Centre for Bio-Separation Technology, VIT University, Vellore, 632014, Tamil Nadu, India
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Welsh N. Does the small tyrosine kinase inhibitor Imatinib mesylate counteract diabetes by affecting pancreatic islet amyloidosis and fibrosis? Expert Opin Investig Drugs 2012; 21:1743-50. [PMID: 22998750 DOI: 10.1517/13543784.2012.724398] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
INTRODUCTION The small tyrosine kinase inhibitor Imatinib Mesylate (Gleevec) protects against diabetes, but it is not known how. AREAS COVERED It has been suggested that islet amyloid and fibrotic deposits promote beta-cell failure and death, leading to Type-2 diabetes. As Imatinib is known to possess anti-fibrotic/amyloid properties, in for example systemic sclerosis and mouse models for Alzheimer's disease, the present review will discuss the possibility that Imatinib acts, at least in part, by ameliorating islet hyalinization and its consequences in the pathogenesis of Type-2 diabetes. EXPERT OPINION A better understanding of how Imatinib counteracts Type-2 diabetes will possibly help to clarify the pathogenic role of islet amyloid and fibrosis, and hopefully lead to improved treatment of the disease.
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Affiliation(s)
- Nils Welsh
- Uppsala University, Department of Medical Cell Biology, Biomedicum, P.O. Box 571, S-751 23, Uppsala, Sweden.
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Muratoglu SC, Belgrave S, Lillis AP, Migliorini M, Robinson S, Smith E, Zhang L, Strickland DK. Macrophage LRP1 suppresses neo-intima formation during vascular remodeling by modulating the TGF-β signaling pathway. PLoS One 2011; 6:e28846. [PMID: 22174911 PMCID: PMC3235159 DOI: 10.1371/journal.pone.0028846] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2011] [Accepted: 11/16/2011] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Vascular remodeling in response to alterations in blood flow has been shown to modulate the formation of neo-intima. This process results from a proliferative response of vascular smooth muscle cells and is influenced by macrophages, which potentiate the development of the intima. The LDL receptor-related protein 1 (LRP1) is a large endocytic and signaling receptor that recognizes a number of ligands including apoE-containing lipoproteins, proteases and protease-inhibitor complexes. Macrophage LRP1 is known to influence the development of atherosclerosis, but its role in vascular remodeling has not been investigated. METHODOLOGY/PRINCIPAL FINDINGS To define the contribution of macrophage LRP1 to vascular remodeling, we generated macrophage specific LRP1-deficient mice (macLRP1-/-) on an LDL receptor (LDLr) knock-out background. Using a carotid ligation model, we detected a 2-fold increase in neointimal thickening and a 2-fold increase in the intima/media ratio in macLRP1-/- mice. Quantitative RT-PCR arrays of the remodeled vessel wall identified increases in mRNA levels of the TGF-β2 gene as well as the Pdgfa gene in macLRP1-/- mice which could account for the alterations in vascular remodeling. Immunohistochemistry analysis revealed increased activation of the TGF-β signaling pathway in macLRP1-/- mice. Further, we observed that LRP1 binds TGF-β2 and macrophages lacking LRP1 accumulate twice as much TGF-β2 in conditioned media. Finally, TNF-α modulation of the TGF-β2 gene in macrophages is attenuated when LRP1 is expressed. Together, the data reveal that LRP1 modulates both the expression and protein levels of TGF-β2 in macrophages. CONCLUSIONS/SIGNIFICANCE Our data demonstrate that macrophage LRP1 protects the vasculature by limiting remodeling events associated with flow. This appears to occur by the ability of macrophage LRP1 to reduce TGF-β2 protein levels and to attenuate expression of the TGF-β2 gene resulting in suppression of the TGF-β signaling pathway.
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Affiliation(s)
- Selen Catania Muratoglu
- Center for Vascular and Inflammatory Diseases, School of Medicine, University of Maryland, Baltimore, Maryland, United States of America
- Department of Surgery, School of Medicine, University of Maryland, Baltimore, Maryland, United States of America
| | - Shani Belgrave
- Center for Vascular and Inflammatory Diseases, School of Medicine, University of Maryland, Baltimore, Maryland, United States of America
- Department of Surgery, School of Medicine, University of Maryland, Baltimore, Maryland, United States of America
| | - Anna P. Lillis
- Center for Vascular and Inflammatory Diseases, School of Medicine, University of Maryland, Baltimore, Maryland, United States of America
- Department of Pathology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Mary Migliorini
- Center for Vascular and Inflammatory Diseases, School of Medicine, University of Maryland, Baltimore, Maryland, United States of America
- Department of Surgery, School of Medicine, University of Maryland, Baltimore, Maryland, United States of America
| | - Susan Robinson
- Center for Vascular and Inflammatory Diseases, School of Medicine, University of Maryland, Baltimore, Maryland, United States of America
- Department of Surgery, School of Medicine, University of Maryland, Baltimore, Maryland, United States of America
| | - Elizabeth Smith
- Center for Vascular and Inflammatory Diseases, School of Medicine, University of Maryland, Baltimore, Maryland, United States of America
| | - Li Zhang
- Center for Vascular and Inflammatory Diseases, School of Medicine, University of Maryland, Baltimore, Maryland, United States of America
- Department of Physiology, School of Medicine, University of Maryland, Baltimore, Maryland, United States of America
| | - Dudley K. Strickland
- Center for Vascular and Inflammatory Diseases, School of Medicine, University of Maryland, Baltimore, Maryland, United States of America
- Department of Physiology, School of Medicine, University of Maryland, Baltimore, Maryland, United States of America
- Department of Surgery, School of Medicine, University of Maryland, Baltimore, Maryland, United States of America
- * E-mail:
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The unfolded protein response is a major mechanism by which LRP1 regulates Schwann cell survival after injury. J Neurosci 2011; 31:13376-85. [PMID: 21940431 DOI: 10.1523/jneurosci.2850-11.2011] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
In peripheral nerve injury, Schwann cells (SCs) must survive to exert a continuing and essential role in successful nerve regeneration. Herein, we show that peripheral nerve injury is associated with activation of endoplasmic reticulum (ER) stress and the adaptive unfolded protein response (UPR). The UPR culminates in expression of C/EBP homology protein (CHOP), a proapoptotic transcription factor in SCs, unless counteracted by LDL receptor-related protein-1 (LRP1), which serves as a major activator of phosphatidylinositol 3-kinase (PI3K). Sciatic nerve crush injury in rats induced expression of the ER chaperone GRP78/BIP, reflecting an early, corrective phase of the UPR. However, when LRP1 signaling was inhibited with receptor-associated protein, PI3K activity was decreased and CHOP protein expression increased, particularly in myelinating SCs. In cultured SCs, the PKR-like ER kinase target eIF2α was phosphorylated and CHOP was induced by (1) inhibiting PI3K, (2) treating the cells with tumor necrosis factor-α (TNF-α), or (3) genetic silencing of LRP1. CHOP gene deletion in SCs decreased cell death in response to TNF-α. Furthermore, the effects of TNF-α on phosphorylated eIF2α, CHOP, and SC death were blocked by adding LRP1 ligands that augment LRP1-dependent cell signaling to PI3K. Collectively, our results support a model in which UPR-activated signaling pathways represent a major challenge to SC survival in nerve injury. LRP1 functions as a potent activator of PI3K in SCs and, by this mechanism, limits SC apoptosis resulting from increased CHOP expression in nerve injury.
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Cathepsin D is partly endocytosed by the LRP1 receptor and inhibits LRP1-regulated intramembrane proteolysis. Oncogene 2011; 31:3202-12. [PMID: 22081071 DOI: 10.1038/onc.2011.501] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The aspartic protease cathepsin-D (cath-D) is a marker of poor prognosis in breast cancer that is overexpressed and hypersecreted by human breast cancer cells. Secreted pro-cath-D binds to the extracellular domain of the β-chain of the LDL receptor-related protein-1 (LRP1) in fibroblasts. The LRP1 receptor has an 85-kDa transmembrane β-chain and a noncovalently attached 515-kDa extracellular α-chain. LRP1 acts by (1) internalizing many ligands via its α-chain, (2) activating signaling pathways by phosphorylating the LRP1β-chain tyrosine and (3) modulating gene transcription by regulated intramembrane proteolysis (RIP) of its β-chain. LRP1 RIP involves two cleavages: the first liberates the LRP1 ectodomain to give a membrane-associated form, LRP1β-CTF, and the second generates the LRP1β-intracellular domain, LRP1β-ICD, that modulates gene transcription. Here, we investigated the endocytosis of pro-cath-D by LRP1 and the effect of pro-cath-D/LRP1β interaction on LRP1β tyrosine phosphorylation and/or LRP1β RIP. Our results indicate that pro-cath-D was partially endocytosed by LRP1 in fibroblasts. However, pro-cath-D and ectopic cath-D did not stimulate phosphorylation of the LRP1β-chain tyrosine. Interestingly, ectopic cath-D and its catalytically inactive (D231N)cath-D, and pro-(D231N)cath-D all significantly inhibited LRP1 RIP by preventing LRP1β-CTF production. Thus, cath-D inhibits LRP1 RIP independently of its catalytic activity by blocking the first cleavage. As cath-D triggers fibroblast outgrowth by LRP1, we propose that cath-D modulates the growth of fibroblasts by inhibiting LRP1 RIP in the breast tumor microenvironment.
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LRAD3, a novel low-density lipoprotein receptor family member that modulates amyloid precursor protein trafficking. J Neurosci 2011; 31:10836-46. [PMID: 21795536 DOI: 10.1523/jneurosci.5065-10.2011] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
We have identified a novel low-density lipoprotein (LDL) receptor family member, termed LDL receptor class A domain containing 3 (LRAD3), which is expressed in neurons. The LRAD3 gene encodes an ∼50 kDa type I transmembrane receptor with an ectodomain containing three LDLa repeats, a transmembrane domain, and a cytoplasmic domain containing a conserved dileucine internalization motif and two polyproline motifs with potential to interact with WW-domain-containing proteins. Immunohistochemical analysis of mouse brain reveals LRAD3 expression in the cortex and hippocampus. In the mouse hippocampal-derived cell line HT22, LRAD3 partially colocalizes with amyloid precursor protein (APP) and interacts with APP as revealed by coimmunoprecipitation experiments. To identify the portion of APP that interacts with LRAD3, we used solid-phase binding assays that demonstrated that LRAD3 failed to bind to a soluble APP fragment (sAPPα) released after α-secretase cleavage. In contrast, C99, the β-secretase product that remains cell associated, coprecipitated with LRAD3, confirming that regions within this portion of APP are important for associating with LRAD3. The association of LRAD3 with APP increases the amyloidogenic pathway of APP processing, resulting in a decrease in sAPPα production and increased Aβ peptide production. Pulse-chase experiments confirm that LRAD3 expression significantly decreases the cellular half-life of mature APP. These results reveal that LRAD3 influences APP processing and raises the possibility that LRAD3 alters APP function in neurons, including its downstream signaling.
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Ranganathan S, Cao C, Catania J, Migliorini M, Zhang L, Strickland DK. Molecular basis for the interaction of low density lipoprotein receptor-related protein 1 (LRP1) with integrin alphaMbeta2: identification of binding sites within alphaMbeta2 for LRP1. J Biol Chem 2011; 286:30535-30541. [PMID: 21676865 DOI: 10.1074/jbc.m111.265413] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The LDL receptor-related protein 1 (LRP1) is a large endocytic receptor that controls macrophage migration in part by interacting with β(2) integrin receptors. However, the molecular mechanism underlying LRP1 integrin recognition is poorly understood. Here, we report that LRP1 specifically recognizes α(M)β(2) but not its homologous receptor α(L)β(2). The interaction between these two cellular receptors in macrophages is significantly enhanced upon α(M)β(2) activation by LPS and is mediated by multiple regions in both LRP1 and α(M)β(2). Specifically, we find that both the heavy and light chains of LRP1 are involved in α(M)β(2) binding. Within the heavy chain, the binding is mediated primarily via the second and fourth ligand binding repeats. For α(M)β(2), we find that the α(M)-I domain represents a major LRP1 recognition site. Indeed, substitution of the I domain of the α(L)β(2) receptor with that of α(M) confers the α(L)β(2) receptor with the ability to interact with LRP1. Furthermore, we show that residues (160)EQLKKSKTL(170) within the α(M)-I domain represent a major LRP1 recognition site. Given that perturbation of this specific sequence leads to altered adhesive activity of α(M)β(2), our finding suggests that binding of LRP1 to α(M)β(2) could alter integrin function. Indeed, we further demonstrate that the soluble form of LRP1 (sLRP1) inhibits α(M)β(2)-mediated adhesion of cells to fibrinogen. These studies suggest that sLRP1 may attenuate inflammation by modulating integrin function.
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Affiliation(s)
- Sripriya Ranganathan
- Center for Vascular and Inflammatory Diseases, University of Maryland School of Medicine, Baltimore, Maryland 21201; Surgery, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Chunzhang Cao
- Center for Vascular and Inflammatory Diseases, University of Maryland School of Medicine, Baltimore, Maryland 21201; the Departments of Physiology, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Jason Catania
- Center for Vascular and Inflammatory Diseases, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Molly Migliorini
- Center for Vascular and Inflammatory Diseases, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Li Zhang
- Center for Vascular and Inflammatory Diseases, University of Maryland School of Medicine, Baltimore, Maryland 21201; the Departments of Physiology, University of Maryland School of Medicine, Baltimore, Maryland 21201.
| | - Dudley K Strickland
- Center for Vascular and Inflammatory Diseases, University of Maryland School of Medicine, Baltimore, Maryland 21201; Surgery, University of Maryland School of Medicine, Baltimore, Maryland 21201; the Departments of Physiology, University of Maryland School of Medicine, Baltimore, Maryland 21201.
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Zheng W, Lennartsson J, Hendriks W, Heldin CH, Hellberg C. The LAR protein tyrosine phosphatase enables PDGF β-receptor activation through attenuation of the c-Abl kinase activity. Cell Signal 2011; 23:1050-6. [DOI: 10.1016/j.cellsig.2011.01.024] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2011] [Accepted: 01/28/2011] [Indexed: 12/24/2022]
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Geetha N, Mihaly J, Stockenhuber A, Blasi F, Uhrin P, Binder BR, Freissmuth M, Breuss JM. Signal integration and coincidence detection in the mitogen-activated protein kinase/extracellular signal-regulated kinase (ERK) cascade: concomitant activation of receptor tyrosine kinases and of LRP-1 leads to sustained ERK phosphorylation via down-regulation of dual specificity phosphatases (DUSP1 and -6). J Biol Chem 2011; 286:25663-74. [PMID: 21610072 PMCID: PMC3138245 DOI: 10.1074/jbc.m111.221903] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Diverse stimuli can feed into the MAPK/ERK cascade; this includes receptor tyrosine kinases, G protein-coupled receptors, integrins, and scavenger receptors (LDL receptor-related protein (LRP)). Here, we investigated the consequence of concomitant occupancy of the receptor tyrosine kinases (by EGF, basic FGF, VEGF, etc.) and of LRP family members (by LDL or lactoferrin). The simultaneous stimulation of a receptor tyrosine kinase by its cognate ligand and of LRP-1 (by lactoferrin or LDL) resulted in sustained activation of ERK, which was redirected to the cytoplasm. Accordingly, elevated levels of active cytosolic ERK were translated into accelerated adhesion to vitronectin. The sustained ERK response was seen in several cell types, but it was absent in cells deficient in LRP-1 (but not in cells lacking the LDL receptor). This response was also contingent on the presence of urokinase (uPA) and its receptor (uPAR), because it was absent in uPA−/− and uPAR−/− fibroblasts. Combined stimulation of the EGF receptor and of LRP-1 delayed nuclear accumulation of phosphorylated ERK. This shift in favor of cytosolic accumulation of phospho-ERK was accounted for by enhanced proteasomal degradation of dual specificity phosphatases DUSP1 and DUSP6, which precluded dephosphorylation of cytosolic ERK. These observations demonstrate that the ERK cascade can act as a coincidence detector to decode the simultaneous engagement of a receptor tyrosine kinase and of LRP-1 and as a signal integrator that encodes this information in a spatially and temporally distinct biological signal. In addition, the findings provide an explanation of why chronic elevation of LRP-1 ligands (e.g. PAI-1) can predispose to cancer.
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Affiliation(s)
- Nishamol Geetha
- Department of Vascular Biology and Thrombosis Research, Medical University of Vienna, Vienna 1090, Austria
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Targeting non-malignant disorders with tyrosine kinase inhibitors. Nat Rev Drug Discov 2011; 9:956-70. [PMID: 21119733 DOI: 10.1038/nrd3297] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Receptor and non-receptor tyrosine kinases are involved in multiple proliferative signalling pathways. Imatinib, one of the first tyrosine kinase inhibitors (TKIs) to be approved, revolutionized the treatment of chronic myelogenous leukaemia, and other TKIs with different spectra of kinase inhibition are used to treat renal cell carcinoma, non-small-cell lung cancer and colon cancer. Studies also support the potential use of TKIs as anti-proliferative agents in non-malignant disorders such as cardiac hypertrophy, and in benign-proliferative disorders including pulmonary hypertension, lung fibrosis, rheumatoid disorders, atherosclerosis, in-stent restenosis and glomerulonephritis. In this Review, we provide an overview of the most recent developments--both experimental as well as clinical--regarding the therapeutic potential of TKIs in non-malignant disorders.
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Murshid A, Theriault J, Gong J, Calderwood SK. Investigating receptors for extracellular heat shock proteins. Methods Mol Biol 2011; 787:289-302. [PMID: 21898244 DOI: 10.1007/978-1-61779-295-3_22] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Extracellular heat shock proteins (HSP) play important roles in cell signaling and immunity. Many of these effects are mediated by cell surface receptors expressed on a wide range of cell types. We have investigated the nature of such proteins by cloning candidate receptors into cells (CHO-K1) with the rare property of being null for HSP binding. Using this approach, we have discovered that Hsp70 binds to a least two classes of receptor: c-type lectin receptors (CLR) and scavenger receptors (SR). However, the nature of the receptor-ligand interactions is not yet clear. Hsp70 can bind to LOX-1 (a member of both the CLR and SR), with the c-type lectin binding domain (CTLD) as well as the SR family members SREC-I and FEEL-1/CLEVER-1/STABILIN-1, which by contrast have arrays of EGF-like repeats in their extracellular domains. In this chapter, we discuss (1) methods for determining HSP receptors, (2) approaches to study of individual receptors in cells that contain multiple such receptors, and (3) methods for investigating HSP receptor function in vivo.
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Affiliation(s)
- Ayesha Murshid
- Molecular and Cellular Radiation Oncology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
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Muratoglu SC, Mikhailenko I, Newton C, Migliorini M, Strickland DK. Low density lipoprotein receptor-related protein 1 (LRP1) forms a signaling complex with platelet-derived growth factor receptor-beta in endosomes and regulates activation of the MAPK pathway. J Biol Chem 2010; 285:14308-17. [PMID: 20220145 DOI: 10.1074/jbc.m109.046672] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
In addition to its endocytic function, the low density lipoprotein receptor-related protein 1 (LRP1) also contributes to cell signaling events. In the current study, the potential of LRP1 to modulate the platelet-derived growth factor (PDGF) signaling pathway was investigated. PDGF is a key regulator of cell migration and proliferation and mediates the tyrosine phosphorylation of LRP1 within its cytoplasmic domain. In WI-38 fibroblasts, PDGF-mediated LRP1 tyrosine phosphorylation occurred at 37 degrees C but not at 4 degrees C, where endocytosis is minimized. Furthermore, blockade of endocytosis with the dynamin inhibitor, dynasore, also prevented PDGF-mediated LRP1 tyrosine phosphorylation. Immunofluorescence studies revealed co-localization of LRP1 with the PDGF receptor after PDGF treatment within endosomal compartments, whereas surface biotinylation experiments confirmed that phosphorylated LRP1 primarily originates from intracellular compartments. Together, the data reveal the association of these two receptors in endosomal compartments where they form a signaling complex. To study the contribution of LRP1 to PDGF signaling, we used mouse embryonic fibroblasts genetically deficient in LRP1 and identified phenotypic changes in these cell lines in response to PDGF stimulation by performing phospho-site profiling. Of 38 phosphorylated proteins analyzed, 8 were significantly different in LRP1 deficient fibroblasts and were restored when LRP1 was expressed back in these cells. Importantly, the results revealed that LRP1 expression is necessary for PDGF-mediated activation of ERK. Overall, the studies reveal that LRP1 associates with the PDGF receptor in endosomal compartments and modulates its signaling properties affecting the MAPK and Akt/phosphatidylinositol 3-kinase pathways.
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Affiliation(s)
- Selen Catania Muratoglu
- Center for Vascular and Inflammatory Diseases, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
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Tolosano E, Fagoonee S, Morello N, Vinchi F, Fiorito V. Heme scavenging and the other facets of hemopexin. Antioxid Redox Signal 2010; 12:305-20. [PMID: 19650691 DOI: 10.1089/ars.2009.2787] [Citation(s) in RCA: 197] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Hemopexin is an acute-phase plasma glycoprotein, produced mainly by the liver and released into plasma, where it binds heme with high affinity. Other sites of hemopexin synthesis are the nervous system, skeletal muscle, retina, and kidney. The only known receptor for the heme-hemopexin complex is the scavenger receptor, LDL receptor-related protein (LRP)1, which is expressed in most cell types, thus indicating multiple sites of heme-hemopexin complex recovery. The better-characterized function of hemopexin is heme scavenging at the systemic level, consisting of the transport of heme to the liver, where it is catabolyzed or used for the synthesis of hemoproteins or exported to bile canaliculi. This is important both in physiologic heme management for heme-iron recycling and in pathologic conditions associated with intravascular hemolysis to prevent the prooxidant and proinflammatory effects of heme. Other than scavenging heme, the heme-hemopexin complex has been shown to be able to activate signaling pathways, thus promoting cell survival, and to modulate gene expression. In this review, the importance of heme scavenging by hemopexin, as well as the other emerging functions of this protein, are discussed.
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Affiliation(s)
- Emanuela Tolosano
- Molecular Biotechnology Center, University of Torino, Torino, Italy.
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Lindner I, Hemdan NYA, Buchold M, Huse K, Bigl M, Oerlecke I, Ricken A, Gaunitz F, Sack U, Naumann A, Hollborn M, Thal D, Gebhardt R, Birkenmeier G. Alpha2-macroglobulin inhibits the malignant properties of astrocytoma cells by impeding beta-catenin signaling. Cancer Res 2010; 70:277-87. [PMID: 20048078 DOI: 10.1158/0008-5472.can-09-1462] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Targets that could improve the treatment of brain tumors remain important to define. This study of a transformation-associated isoform of alpha2-macroglobulin (A2M*) and its interaction with the low-density lipoprotein receptor-related protein-1 (LRP1) suggests a new mechanism for abrogating the malignant potential of astrocytoma cells. LRP1 bound A2M* found to be associated with an inhibition of tumor cell proliferation, migration, invasion, spheroid formation, and anchorage-independent growth. Transcriptional studies implicated effects on the Wnt/beta-catenin signaling pathway. Notably, LRP1 antibodies could phenocopy the effects of A2M*. Our findings suggest a pathway of tumor suppression in astrocytoma that might be tractable to therapeutic exploitation.
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Affiliation(s)
- Inge Lindner
- Institute of Biochemistry, Department of Ophthalmology, University of Leipzig, Leipzig, Germany
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Rabinovitch M. PPARgamma and the pathobiology of pulmonary arterial hypertension. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2010; 661:447-58. [PMID: 20204748 DOI: 10.1007/978-1-60761-500-2_29] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Peroxisome proliferator-activated receptor gamma (PPARgamma) is a nuclear receptor that functions as a transcription factor to regulate adipogenesis and metabolism by binding to PPAR response elements (PPAREs) in the promoter region of various target genes. Activation of PPARgamma suppresses smooth muscle cell proliferation and migration. This chapter discusses the potential protective role of PPARgamma and its downstream signaling cascades in the development of pulmonary arterial hypertension. Furthermore, the chapter also provides an overview on the cellular and molecular mechanisms involved in PPARgamma-mediated inhibitory effect on pulmonary vascular remodeling, a major contributor to the elevated pulmonary vascular resistance in patients with pulmonary arterial hypertension.
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Affiliation(s)
- Marlene Rabinovitch
- The Wall Center for Pulmonary Vascular Diseases, Stanford University School of Medicine, Stanford, CA, USA.
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Potential utility of small tyrosine kinase inhibitors in the treatment of diabetes. Clin Sci (Lond) 2009; 118:241-7. [PMID: 19886867 DOI: 10.1042/cs20090348] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Altered tyrosine kinase signalling has been implicated in several diseases, paving the way for the development of small-molecule TKIs (tyrosine kinase inhibitors). TKIs such as imatinib, sunitinib and dasatinib are clinically used for treating chronic myeloid leukaemia, gastrointestinal stromal tumours and other malignancies. In addition to their use as anti-cancer agents, increasing evidence points towards an anti-diabetic effect of these TKIs. Imatinib and other TKIs counteract diabetes not only in non-obese diabetic mice, but also in streptozotocin diabetic mice, db/db mice, high-fat-treated rats and humans with T2D (Type 2 diabetes). Although the mechanisms of protection need to be investigated further, the effects of imatinib and other TKIs in human T2D and the rapidly growing findings from animal models of T1D (Type 1 diabetes) and T2D are encouraging and give hope to improved treatment of human diabetes. In the present article, we review the anti-diabetic effects of TKIs which appear to involve both protection against beta-cell death and improved insulin sensitivity. Considering the relatively mild side effects of TKIs, we hypothesize that TKIs could be used to treat new-onset T1D, prevent T1D in individuals at high risk of developing the disease, treat the late stages of T2D and improve the outcome of islet transplantation.
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Guttman M, Betts GN, Barnes H, Ghassemian M, van der Geer P, Komives EA. Interactions of the NPXY microdomains of the low density lipoprotein receptor-related protein 1. Proteomics 2009; 9:5016-28. [PMID: 19771558 PMCID: PMC2862490 DOI: 10.1002/pmic.200900457] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The low density lipoprotein receptor-related protein 1 (LRP1) mediates internalization of a large number of proteins and protein-lipid complexes and is widely implicated in Alzheimer's disease. The cytoplasmic domain of LRP1 (LRP1-CT) can be phosphorylated by activated protein-tyrosine kinases at two NPXY motifs in LRP1-CT; Tyr 4507 is readily phosphorylated and must be phosphorylated before phosphorylation of Tyr 4473 occurs. Pull-down experiments from brain lysate revealed numerous proteins binding to LRP1-CT, but the results were highly variable. To separate which proteins bind to each NPXY motif and their phosphorylation dependence, each NPXY motif microdomain was prepared in both phosphorylated and non-phosphorylated forms and used to probe rodent brain extracts for binding proteins. Proteins that bound specifically to the microdomains were identified by LC-MS/MS, and confirmed by Western blot. Recombinant proteins were then tested for binding to each NPXY motif. The NPXY(4507) (membrane distal) was found to interact with a large number of proteins, many of which only bound the tyrosine-phosphorylated form. This microdomain also bound a significant number of other proteins in the unphosphorylated state. Many of the interactions were later confirmed to be direct with recombinant proteins. The NPXY(4473) (membrane proximal) bound many fewer proteins and only to the phosphorylated form.
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Affiliation(s)
- Miklos Guttman
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Dr. La Jolla, CA 92093-0378
| | - Gina N. Betts
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Dr. La Jolla, CA 92093-0378
| | - Helen Barnes
- Department of Chemistry and Biochemistry, San Diego State University, 5500 Campanile Dr. San Diego CA 92182-1030
| | | | - Peter van der Geer
- Department of Chemistry and Biochemistry, San Diego State University, 5500 Campanile Dr. San Diego CA 92182-1030
| | - Elizabeth A. Komives
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Dr. La Jolla, CA 92093-0378
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