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Trost A, Bruckner D, Rivera FJ, Reitsamer HA. Pericytes in the Retina. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1122:1-26. [DOI: 10.1007/978-3-030-11093-2_1] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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52
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Sweeney MD, Zhao Z, Montagne A, Nelson AR, Zlokovic BV. Blood-Brain Barrier: From Physiology to Disease and Back. Physiol Rev 2019; 99:21-78. [PMID: 30280653 PMCID: PMC6335099 DOI: 10.1152/physrev.00050.2017] [Citation(s) in RCA: 1207] [Impact Index Per Article: 241.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 04/17/2018] [Accepted: 04/17/2018] [Indexed: 12/12/2022] Open
Abstract
The blood-brain barrier (BBB) prevents neurotoxic plasma components, blood cells, and pathogens from entering the brain. At the same time, the BBB regulates transport of molecules into and out of the central nervous system (CNS), which maintains tightly controlled chemical composition of the neuronal milieu that is required for proper neuronal functioning. In this review, we first examine molecular and cellular mechanisms underlying the establishment of the BBB. Then, we focus on BBB transport physiology, endothelial and pericyte transporters, and perivascular and paravascular transport. Next, we discuss rare human monogenic neurological disorders with the primary genetic defect in BBB-associated cells demonstrating the link between BBB breakdown and neurodegeneration. Then, we review the effects of genes underlying inheritance and/or increased susceptibility for Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease, and amyotrophic lateral sclerosis (ALS) on BBB in relation to other pathologies and neurological deficits. We next examine how BBB dysfunction relates to neurological deficits and other pathologies in the majority of sporadic AD, PD, and ALS cases, multiple sclerosis, other neurodegenerative disorders, and acute CNS disorders such as stroke, traumatic brain injury, spinal cord injury, and epilepsy. Lastly, we discuss BBB-based therapeutic opportunities. We conclude with lessons learned and future directions, with emphasis on technological advances to investigate the BBB functions in the living human brain, and at the molecular and cellular level, and address key unanswered questions.
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Affiliation(s)
- Melanie D Sweeney
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California , Los Angeles, California ; and Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California , Los Angeles, California
| | - Zhen Zhao
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California , Los Angeles, California ; and Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California , Los Angeles, California
| | - Axel Montagne
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California , Los Angeles, California ; and Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California , Los Angeles, California
| | - Amy R Nelson
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California , Los Angeles, California ; and Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California , Los Angeles, California
| | - Berislav V Zlokovic
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California , Los Angeles, California ; and Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California , Los Angeles, California
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53
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Walcott BP, Winkler EA, Rouleau GA, Lawton MT. Molecular, Cellular, and Genetic Determinants of Sporadic Brain Arteriovenous Malformations. Neurosurgery 2018; 63 Suppl 1:37-42. [PMID: 27399362 DOI: 10.1227/neu.0000000000001300] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Affiliation(s)
- Brian P Walcott
- Department of Neurological Surgery and.,Center for Cerebrovascular Research, University of California, San Francisco, San Francisco, California
| | - Ethan A Winkler
- Department of Neurological Surgery and.,Center for Cerebrovascular Research, University of California, San Francisco, San Francisco, California
| | - Guy A Rouleau
- Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada.,Montreal Neurological Institute, Montreal, Quebec, Canada
| | - Michael T Lawton
- Department of Neurological Surgery and.,Center for Cerebrovascular Research, University of California, San Francisco, San Francisco, California
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54
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Kolinko Y, Kralickova M, Tonar Z. The impact of pericytes on the brain and approaches for their morphological analysis. J Chem Neuroanat 2018; 91:35-45. [DOI: 10.1016/j.jchemneu.2018.04.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 04/10/2018] [Accepted: 04/15/2018] [Indexed: 12/15/2022]
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55
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Mihajlica N, Betsholtz C, Hammarlund-Udenaes M. Pharmacokinetics of pericyte involvement in small-molecular drug transport across the blood-brain barrier. Eur J Pharm Sci 2018; 122:77-84. [DOI: 10.1016/j.ejps.2018.06.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 06/05/2018] [Accepted: 06/18/2018] [Indexed: 12/17/2022]
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56
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Tang X, Eberhart JK, Cleves MA, Li J, Li M, MacLeod S, Nembhard WN, Hobbs CA. PDGFRA gene, maternal binge drinking and obstructive heart defects. Sci Rep 2018; 8:11083. [PMID: 30038270 PMCID: PMC6056529 DOI: 10.1038/s41598-018-29160-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 06/15/2018] [Indexed: 01/06/2023] Open
Abstract
Obstructive heart defects (OHDs) are a major health concern worldwide. The platelet-derived growth factor (PDGF) genes are known to have regulatory functions that are essential for proper heart development. In a zebrafish model, Pdgfra was further demonstrated to interact with ethanol during craniofacial development. In this article, we investigated interactions between variants in PDGF genes and periconceptional alcohol exposure on the risk of OHDs by applying log-linear models to 806 OHD case and 995 control families enrolled in the National Birth Defects Prevention Study. The interactions between four variants in PDGFA and maternal binge drinking reached a nominal significance level. The maternal T allele of rs869978 was estimated to increase OHD risk among women who binge drink, while infant genotypes of rs2291591, rs2228230, rs1547904, and rs869978 may reduce the risk. Although none of these associations remain statistically significant after multiple testing adjustment and the estimated maternal effect may be influenced by unknown confounding factors, such as maternal smoking, these findings are consistent with previous animal studies supporting potential interactions between the PDGFRA gene and maternal alcohol exposure. Replication studies with larger sample sizes are needed to further elucidate this potential interplay and its influence on OHD risks.
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Affiliation(s)
- Xinyu Tang
- Biostatistics Program, University of Arkansas for Medical Sciences, Arkansas Children's Research Institute, Little Rock, 72202, USA
| | - Johann K Eberhart
- Department of Molecular and Cell and Developmental Biology, Institute for Cellular and Molecular Biology and Institute for Neuroscience, University of Texas, Austin, 78712, USA
| | - Mario A Cleves
- Biostatistics Program, University of Arkansas for Medical Sciences, Arkansas Children's Research Institute, Little Rock, 72202, USA
| | - Jingyun Li
- Biostatistics Program, University of Arkansas for Medical Sciences, Arkansas Children's Research Institute, Little Rock, 72202, USA
| | - Ming Li
- Department of Epidemiology and Biostatistics, School of Public Health, Indiana University at Bloomington, Bloomington, 47405, USA
| | - Stewart MacLeod
- Division of Birth Defects Research, Department of Pediatrics, College of Medicine, University of Arkansas for Medical Sciences, Arkansas Children's Research Institute, Little Rock, 72202, USA
| | - Wendy N Nembhard
- Division of Birth Defects Research, Department of Pediatrics, College of Medicine, University of Arkansas for Medical Sciences, Arkansas Children's Research Institute, Little Rock, 72202, USA
| | - Charlotte A Hobbs
- Division of Birth Defects Research, Department of Pediatrics, College of Medicine, University of Arkansas for Medical Sciences, Arkansas Children's Research Institute, Little Rock, 72202, USA.
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57
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Zinkle A, Mohammadi M. A threshold model for receptor tyrosine kinase signaling specificity and cell fate determination. F1000Res 2018; 7:F1000 Faculty Rev-872. [PMID: 29983915 PMCID: PMC6013765 DOI: 10.12688/f1000research.14143.1] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/18/2018] [Indexed: 11/20/2022] Open
Abstract
Upon ligand engagement, the single-pass transmembrane receptor tyrosine kinases (RTKs) dimerize to transmit qualitatively and quantitatively different intracellular signals that alter the transcriptional landscape and thereby determine the cellular response. The molecular mechanisms underlying these fundamental events are not well understood. Considering recent insights into the structural biology of fibroblast growth factor signaling, we propose a threshold model for RTK signaling specificity in which quantitative differences in the strength/longevity of ligand-induced receptor dimers on the cell surface lead to quantitative differences in the phosphorylation of activation loop (A-loop) tyrosines as well as qualitative differences in the phosphorylation of tyrosines mediating substrate recruitment. In this model, quantitative differences on A-loop tyrosine phosphorylation result in gradations in kinase activation, leading to the generation of intracellular signals of varying amplitude/duration. In contrast, qualitative differences in the pattern of tyrosine phosphorylation on the receptor result in the recruitment/activation of distinct substrates/intracellular pathways. Commensurate with both the dynamics of the intracellular signal and the types of intracellular pathways activated, unique transcriptional signatures are established. Our model provides a framework for engineering clinically useful ligands that can tune receptor dimerization stability so as to bias the cellular transcriptome to achieve a desired cellular output.
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Affiliation(s)
- Allen Zinkle
- Department of Biochemistry & Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
| | - Moosa Mohammadi
- Department of Biochemistry & Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
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58
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Kisler K, Lazic D, Sweeney MD, Plunkett S, Khatib ME, Vinogradov SA, Boas DA, Sakadžić S, Zlokovic BV. In vivo imaging and analysis of cerebrovascular hemodynamic responses and tissue oxygenation in the mouse brain. Nat Protoc 2018; 13:1377-1402. [PMID: 29844521 PMCID: PMC6402338 DOI: 10.1038/nprot.2018.034] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cerebrovascular dysfunction has an important role in the pathogenesis of multiple brain disorders. Measurement of hemodynamic responses in vivo can be challenging, particularly as techniques are often not described in sufficient detail and vary between laboratories. We present a set of standardized in vivo protocols that describe high-resolution two-photon microscopy and intrinsic optical signal (IOS) imaging to evaluate capillary and arteriolar responses to a stimulus, regional hemodynamic responses, and oxygen delivery to the brain. The protocol also describes how to measure intrinsic NADH fluorescence to understand how blood O2 supply meets the metabolic demands of activated brain tissue, and to perform resting-state absolute oxygen partial pressure (pO2) measurements of brain tissue. These methods can detect cerebrovascular changes at far higher resolution than MRI techniques, although the optical nature of these techniques limits their achievable imaging depths. Each individual procedure requires 1-2 h to complete, with two to three procedures typically performed per animal at a time. These protocols are broadly applicable in studies of cerebrovascular function in healthy and diseased brain in any of the existing mouse models of neurological and vascular disorders. All these procedures can be accomplished by a competent graduate student or experienced technician, except the two-photon measurement of absolute pO2 level, which is better suited to a more experienced, postdoctoral-level researcher.
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Affiliation(s)
- Kassandra Kisler
- Department of Physiology and Neuroscience and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90089
| | - Divna Lazic
- Department of Physiology and Neuroscience and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90089
- Department of Neurobiology, Institute for Biological Research, University of Belgrade, Belgrade, Republic of Serbia
| | - Melanie D. Sweeney
- Department of Physiology and Neuroscience and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90089
| | - Shane Plunkett
- Departments of Biochemistry and Biophysics and of Chemistry, University of Pennsylvania, Philadelphia, PA 19104
| | - Mirna El Khatib
- Departments of Biochemistry and Biophysics and of Chemistry, University of Pennsylvania, Philadelphia, PA 19104
| | - Sergei A. Vinogradov
- Departments of Biochemistry and Biophysics and of Chemistry, University of Pennsylvania, Philadelphia, PA 19104
| | - David A. Boas
- Optics Division, MGH/HMS/MIT Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, 149 13th Street, Charlestown, MA 02129
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02215
| | - Sava Sakadžić
- Optics Division, MGH/HMS/MIT Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, 149 13th Street, Charlestown, MA 02129
| | - Berislav V. Zlokovic
- Department of Physiology and Neuroscience and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90089
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59
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Montagne A, Nikolakopoulou AM, Zhao Z, Sagare AP, Si G, Lazic D, Barnes SR, Daianu M, Ramanathan A, Go A, Lawson EJ, Wang Y, Mack WJ, Thompson PM, Schneider JA, Varkey J, Langen R, Mullins E, Jacobs RE, Zlokovic BV. Pericyte degeneration causes white matter dysfunction in the mouse central nervous system. Nat Med 2018; 24:326-337. [PMID: 29400711 PMCID: PMC5840035 DOI: 10.1038/nm.4482] [Citation(s) in RCA: 271] [Impact Index Per Article: 45.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 01/04/2018] [Indexed: 02/07/2023]
Abstract
Diffuse white-matter disease associated with small-vessel disease and dementia is prevalent in the elderly. The biological mechanisms, however, remain elusive. Using pericyte-deficient mice, magnetic resonance imaging, viral-based tract-tracing, and behavior and tissue analysis, we found that pericyte degeneration disrupted white-matter microcirculation, resulting in an accumulation of toxic blood-derived fibrin(ogen) deposits and blood-flow reductions, which triggered a loss of myelin, axons and oligodendrocytes. This disrupted brain circuits, leading to white-matter functional deficits before neuronal loss occurs. Fibrinogen and fibrin fibrils initiated autophagy-dependent cell death in oligodendrocyte and pericyte cultures, whereas pharmacological and genetic manipulations of systemic fibrinogen levels in pericyte-deficient, but not control mice, influenced the degree of white-matter fibrin(ogen) deposition, pericyte degeneration, vascular pathology and white-matter changes. Thus, our data indicate that pericytes control white-matter structure and function, which has implications for the pathogenesis and treatment of human white-matter disease associated with small-vessel disease.
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Affiliation(s)
- Axel Montagne
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
| | - Angeliki M. Nikolakopoulou
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
| | - Zhen Zhao
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
| | - Abhay P. Sagare
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
| | - Gabriel Si
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
| | - Divna Lazic
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
- Department of Neurobiology, Institute for Biological Research, University of Belgrade, Belgrade, Republic of Serbia
| | - Samuel R. Barnes
- Biological Imaging Center, Beckman Institute, California Institute of Technology, Pasadena, CA 91101, USA
| | - Madelaine Daianu
- Imaging Genetics Center, Mark & Mary Stevens Neuroimaging & Informatics Institute, University of Southern California, Marina del Rey, CA 90292, USA
| | - Anita Ramanathan
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
| | - Ariel Go
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
| | - Erica J. Lawson
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
| | - Yaoming Wang
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
| | - William J. Mack
- Department of Neurological Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
| | - Paul M. Thompson
- Imaging Genetics Center, Mark & Mary Stevens Neuroimaging & Informatics Institute, University of Southern California, Marina del Rey, CA 90292, USA
| | - Julie A. Schneider
- Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL 60612, USA
| | - Jobin Varkey
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
| | - Ralf Langen
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
| | - Eric Mullins
- Division of Hematology and Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH 45229-3039
| | - Russell E. Jacobs
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
- Biological Imaging Center, Beckman Institute, California Institute of Technology, Pasadena, CA 91101, USA
| | - Berislav V. Zlokovic
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
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60
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Duran CL, Howell DW, Dave JM, Smith RL, Torrie ME, Essner JJ, Bayless KJ. Molecular Regulation of Sprouting Angiogenesis. Compr Physiol 2017; 8:153-235. [PMID: 29357127 DOI: 10.1002/cphy.c160048] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The term angiogenesis arose in the 18th century. Several studies over the next 100 years laid the groundwork for initial studies performed by the Folkman laboratory, which were at first met with some opposition. Once overcome, the angiogenesis field has flourished due to studies on tumor angiogenesis and various developmental models that can be genetically manipulated, including mice and zebrafish. In addition, new discoveries have been aided by the ability to isolate primary endothelial cells, which has allowed dissection of various steps within angiogenesis. This review will summarize the molecular events that control angiogenesis downstream of biochemical factors such as growth factors, cytokines, chemokines, hypoxia-inducible factors (HIFs), and lipids. These and other stimuli have been linked to regulation of junctional molecules and cell surface receptors. In addition, the contribution of cytoskeletal elements and regulatory proteins has revealed an intricate role for mobilization of actin, microtubules, and intermediate filaments in response to cues that activate the endothelium. Activating stimuli also affect various focal adhesion proteins, scaffold proteins, intracellular kinases, and second messengers. Finally, metalloproteinases, which facilitate matrix degradation and the formation of new blood vessels, are discussed, along with our knowledge of crosstalk between the various subclasses of these molecules throughout the text. Compr Physiol 8:153-235, 2018.
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Affiliation(s)
- Camille L Duran
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, Texas, USA
| | - David W Howell
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, Texas, USA
| | - Jui M Dave
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, Texas, USA
| | - Rebecca L Smith
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, Texas, USA
| | - Melanie E Torrie
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa, USA
| | - Jeffrey J Essner
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa, USA
| | - Kayla J Bayless
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, Texas, USA
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61
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Eilken HM, Diéguez-Hurtado R, Schmidt I, Nakayama M, Jeong HW, Arf H, Adams S, Ferrara N, Adams RH. Pericytes regulate VEGF-induced endothelial sprouting through VEGFR1. Nat Commun 2017; 8:1574. [PMID: 29146905 PMCID: PMC5691060 DOI: 10.1038/s41467-017-01738-3] [Citation(s) in RCA: 162] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 10/11/2017] [Indexed: 01/19/2023] Open
Abstract
Pericytes adhere to the abluminal surface of endothelial tubules and are required for the formation of stable vascular networks. Defective endothelial cell-pericyte interactions are frequently observed in diseases characterized by compromised vascular integrity such as diabetic retinopathy. Many functional properties of pericytes and their exact role in the regulation of angiogenic blood vessel growth remain elusive. Here we show that pericytes promote endothelial sprouting in the postnatal retinal vasculature. Using genetic and pharmacological approaches, we show that the expression of vascular endothelial growth factor receptor 1 (VEGFR1) by pericytes spatially restricts VEGF signalling. Angiogenic defects caused by pericyte depletion are phenocopied by intraocular injection of VEGF-A or pericyte-specific inactivation of the murine gene encoding VEGFR1. Our findings establish that pericytes promote endothelial sprouting, which results in the loss of side branches and the enlargement of vessels when pericyte function is impaired or lost.
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Affiliation(s)
- Hanna M Eilken
- Max Planck Institute for Molecular Biomedicine, Department of Tissue Morphogenesis and University of Münster, Faculty of Medicine, D-48149, Münster, Germany.,Bayer AG, Aprather Weg 18a, 42113, Wuppertal, Germany
| | - Rodrigo Diéguez-Hurtado
- Max Planck Institute for Molecular Biomedicine, Department of Tissue Morphogenesis and University of Münster, Faculty of Medicine, D-48149, Münster, Germany
| | - Inga Schmidt
- Max Planck Institute for Molecular Biomedicine, Department of Tissue Morphogenesis and University of Münster, Faculty of Medicine, D-48149, Münster, Germany
| | - Masanori Nakayama
- Max Planck Institute for Molecular Biomedicine, Department of Tissue Morphogenesis and University of Münster, Faculty of Medicine, D-48149, Münster, Germany.,Max Planck Institute for Heart and Lung Research, Laboratory for Cell Polarity and Organogenesis, 61231, Bad Nauheim, Germany
| | - Hyun-Woo Jeong
- Max Planck Institute for Molecular Biomedicine, Department of Tissue Morphogenesis and University of Münster, Faculty of Medicine, D-48149, Münster, Germany
| | - Hendrik Arf
- Max Planck Institute for Molecular Biomedicine, Department of Tissue Morphogenesis and University of Münster, Faculty of Medicine, D-48149, Münster, Germany
| | - Susanne Adams
- Max Planck Institute for Molecular Biomedicine, Department of Tissue Morphogenesis and University of Münster, Faculty of Medicine, D-48149, Münster, Germany
| | - Napoleone Ferrara
- University of California San Diego Medical Center, 9500 Gilman Drive, La Jolla, CA, 92093, USA
| | - Ralf H Adams
- Max Planck Institute for Molecular Biomedicine, Department of Tissue Morphogenesis and University of Münster, Faculty of Medicine, D-48149, Münster, Germany.
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62
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He C, Medley SC, Kim J, Sun C, Kwon HR, Sakashita H, Pincu Y, Yao L, Eppard D, Dai B, Berry WL, Griffin TM, Olson LE. STAT1 modulates tissue wasting or overgrowth downstream from PDGFRβ. Genes Dev 2017; 31:1666-1678. [PMID: 28924035 PMCID: PMC5647937 DOI: 10.1101/gad.300384.117] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 08/21/2017] [Indexed: 12/17/2022]
Abstract
In this study, He et al. investigated how gain-of-function PDGFRβ mutations cause human disease, specifically whether PDGFRB mutations alone are responsible for genetic diseases characterized by musculoskeletal wasting or overgrowth. Using a genetic approach, their findings suggest a molecular mechanism by which STAT1 suppresses PDGFRβ-driven fibrosis and bone growth. Platelet-derived growth factor (PDGF) acts through two conserved receptor tyrosine kinases: PDGFRα and PDGFRβ. Gain-of-function mutations in human PDGFRB have been linked recently to genetic diseases characterized by connective tissue wasting (Penttinen syndrome) or overgrowth (Kosaki overgrowth syndrome), but it is unclear whether PDGFRB mutations alone are responsible. Mice with constitutive PDGFRβ signaling caused by a kinase domain mutation (D849V) develop lethal autoinflammation. Here we used a genetic approach to investigate the mechanism of autoinflammation in Pdgfrb+/D849V mice and test the hypothesis that signal transducer and activator of transcription 1 (STAT1) mediates this phenotype. We show that Pdgfrb+/D849V mice with Stat1 knockout (Stat1−/−Pdgfrb+/D849V) are rescued from autoinflammation and have improved life span compared with Stat1+/−Pdgfrb+/D849V mice. Furthermore, PDGFRβ–STAT1 signaling suppresses PDGFRβ itself. Thus, Stat1−/−Pdgfrb+/D849V fibroblasts exhibit increased PDGFRβ signaling, and mice develop progressive overgrowth, a distinct phenotype from the wasting seen in Stat1+/−Pdgfrb+/D849V mice. Deletion of interferon receptors (Ifnar1 or Ifngr1) does not rescue wasting in Pdgfrb+/D849V mice, indicating that interferons are not required for autoinflammation. These results provide functional evidence that elevated PDGFRβ signaling causes tissue wasting or overgrowth reminiscent of human genetic syndromes and that the STAT1 pathway is a crucial modulator of this phenotypic spectrum.
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Affiliation(s)
- Chaoyong He
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104, USA.,State Key Laboratory of Natural Medicines, Department of Pharmacology, China Pharmaceutical University, Nanjing 210009, China
| | - Shayna C Medley
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104, USA.,Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
| | - Jang Kim
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104, USA
| | - Chengyi Sun
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104, USA.,Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
| | - Hae Ryong Kwon
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104, USA
| | - Hiromi Sakashita
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104, USA
| | - Yair Pincu
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104, USA
| | - Longbiao Yao
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104, USA
| | - Danielle Eppard
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104, USA
| | - Bojie Dai
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
| | - William L Berry
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
| | - Timothy M Griffin
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104, USA
| | - Lorin E Olson
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104, USA.,Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
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63
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Shen EM, McCloskey KE. Development of Mural Cells: From In Vivo Understanding to In Vitro Recapitulation. Stem Cells Dev 2017; 26:1020-1041. [DOI: 10.1089/scd.2017.0020] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Affiliation(s)
- Edwin M. Shen
- Graduate Program in Biological Engineering and Small-scale Technologies
| | - Kara E. McCloskey
- Graduate Program in Biological Engineering and Small-scale Technologies
- School of Engineering, University of California, Merced, Merced, California
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64
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Sweeney MD, Ayyadurai S, Zlokovic BV. Pericytes of the neurovascular unit: key functions and signaling pathways. Nat Neurosci 2017; 19:771-83. [PMID: 27227366 DOI: 10.1038/nn.4288] [Citation(s) in RCA: 706] [Impact Index Per Article: 100.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 02/29/2016] [Indexed: 12/12/2022]
Abstract
Pericytes are vascular mural cells embedded in the basement membrane of blood microvessels. They extend their processes along capillaries, pre-capillary arterioles and post-capillary venules. CNS pericytes are uniquely positioned in the neurovascular unit between endothelial cells, astrocytes and neurons. They integrate, coordinate and process signals from their neighboring cells to generate diverse functional responses that are critical for CNS functions in health and disease, including regulation of the blood-brain barrier permeability, angiogenesis, clearance of toxic metabolites, capillary hemodynamic responses, neuroinflammation and stem cell activity. Here we examine the key signaling pathways between pericytes and their neighboring endothelial cells, astrocytes and neurons that control neurovascular functions. We also review the role of pericytes in CNS disorders including rare monogenic diseases and complex neurological disorders such as Alzheimer's disease and brain tumors. Finally, we discuss directions for future studies.
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Affiliation(s)
- Melanie D Sweeney
- Department of Physiology and Biophysics, Keck School of Medicine of the University of Southern California, Los Angeles, California, USA.,Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, Los Angeles, California, USA
| | - Shiva Ayyadurai
- Systems Biology Group, CytoSolve Research Division, Cambridge, Massachusetts, USA
| | - Berislav V Zlokovic
- Department of Physiology and Biophysics, Keck School of Medicine of the University of Southern California, Los Angeles, California, USA.,Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, Los Angeles, California, USA
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65
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Jiang Y, Berry DC, Jo A, Tang W, Arpke RW, Kyba M, Graff JM. A PPARγ transcriptional cascade directs adipose progenitor cell-niche interaction and niche expansion. Nat Commun 2017. [PMID: 28649987 PMCID: PMC5490270 DOI: 10.1038/ncomms15926] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Adipose progenitor cells (APCs) reside in a vascular niche, located within the perivascular compartment of adipose tissue blood vessels. Yet, the signals and mechanisms that govern adipose vascular niche formation and APC niche interaction are unknown. Here we show that the assembly and maintenance of the adipose vascular niche is controlled by PPARγ acting within APCs. PPARγ triggers a molecular hierarchy that induces vascular sprouting, APC vessel niche affinity and APC vessel occupancy. Mechanistically, PPARγ transcriptionally activates PDGFRβ and VEGF. APC expression and activation of PDGFRβ promotes the recruitment and retention of APCs to the niche. Pharmacologically, targeting PDGFRβ disrupts APC niche contact thus blocking adipose tissue expansion. Moreover, enhanced APC expression of VEGF stimulates endothelial cell proliferation and expands the adipose niche. Consequently, APC niche communication and retention are boosted by VEGF thereby impairing adipogenesis. Our data indicate that APCs direct adipose tissue niche expansion via a PPARγ-initiated PDGFRβ and VEGF transcriptional axis. Adipocyte progenitor cells (APCs) are found tethered to adipose tissue blood vessel walls and can differentiate into adipocytes. Here the authors show that PPARγ controls angiogenesis by stimulating APC–blood vessel interaction and retention via a transcriptional network that includes PDGFRβ and VEGF.
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Affiliation(s)
- Yuwei Jiang
- Division of Endocrinology, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.,Department of Developmental Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Daniel C Berry
- Division of Endocrinology, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.,Department of Developmental Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Ayoung Jo
- Department of Developmental Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Wei Tang
- Department of Developmental Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Robert W Arpke
- Lillehei Heart Institute, University of Minnesota, Minneapolis, Minnesota 55455, USA.,Department of Medicine, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Michael Kyba
- Lillehei Heart Institute, University of Minnesota, Minneapolis, Minnesota 55455, USA.,Department of Pediatrics, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Jonathan M Graff
- Division of Endocrinology, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.,Department of Developmental Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.,Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
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66
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Haddad-Tóvolli R, Dragano NRV, Ramalho AFS, Velloso LA. Development and Function of the Blood-Brain Barrier in the Context of Metabolic Control. Front Neurosci 2017; 11:224. [PMID: 28484368 PMCID: PMC5399017 DOI: 10.3389/fnins.2017.00224] [Citation(s) in RCA: 128] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 04/04/2017] [Indexed: 12/21/2022] Open
Abstract
Under physiological conditions, the brain consumes over 20% of the whole body energy supply. The blood-brain barrier (BBB) allows dynamic interactions between blood capillaries and the neuronal network in order to provide an adequate control of molecules that are transported in and out of the brain. Alterations in the BBB structure and function affecting brain accessibility to nutrients and exit of toxins are found in a number of diseases, which in turn may disturb brain function and nutrient signaling. In this review we explore the major advances obtained in the understanding of the BBB development and how its structure impacts on function. Furthermore, we focus on the particularities of the barrier permeability in the hypothalamus, its role in metabolic control and the potential impact of hypothalamic BBB abnormities in metabolic related diseases.
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Affiliation(s)
- Roberta Haddad-Tóvolli
- Laboratory of Cell Signaling and Obesity and Comorbidities Research Center, Faculty of Medical Sciences, University of CampinasCampinas, Brazil
| | | | | | - Licio A. Velloso
- Laboratory of Cell Signaling and Obesity and Comorbidities Research Center, Faculty of Medical Sciences, University of CampinasCampinas, Brazil
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67
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Nikolakopoulou AM, Zhao Z, Montagne A, Zlokovic BV. Regional early and progressive loss of brain pericytes but not vascular smooth muscle cells in adult mice with disrupted platelet-derived growth factor receptor-β signaling. PLoS One 2017; 12:e0176225. [PMID: 28441414 PMCID: PMC5404855 DOI: 10.1371/journal.pone.0176225] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 03/18/2017] [Indexed: 11/19/2022] Open
Abstract
Pericytes regulate key neurovascular functions of the brain. Studies in pericyte-deficient transgenic mice with aberrant signaling between endothelial-derived platelet-derived growth factor BB (PDGF-BB) and platelet-derived growth factor receptor β (PDGFRβ) in pericytes have contributed to better understanding of the role of pericytes in the brain. Here, we studied PdgfrβF7/F7 mice, which carry seven point mutations that disrupt PDGFRβ signaling causing loss of pericytes and vascular smooth muscle cells (VSMCs) in the developing brain. We asked whether these mice have a stable or progressive vascular phenotype after birth, and whether both pericyte and VSMCs populations are affected in the adult brain. We found an early and progressive region-dependent loss of brain pericytes, microvascular reductions and blood-brain barrier (BBB) breakdown, which were more pronounced in the cortex, hippocampus and striatum than in the thalamus, whereas VSMCs population remained unaffected at the time when pericyte loss was already established. For example, compared to age-matched controls, PdgfrβF7/F7 mice between 4-6 and 36-48 weeks of age developed a region-dependent loss in pericyte coverage (22-46, 24-44 and 4-31%) and cell numbers (36-49, 34-64 and 11-36%), reduction in capillary length (20-39, 13-46 and 1-30%), and an increase in extravascular fibrinogen-derived deposits (3.4-5.2, 2.8-4.1 and 0-3.6-fold) demonstrating BBB breakdown in the cortex, hippocampus and thalamus, respectively. Capillary reductions and BBB breakdown correlated with loss of pericyte coverage. Our data suggest that PdgfrβF7/F7 mice develop an aggressive and rapid vascular phenotype without appreciable early involvement of VSMCs, therefore providing a valuable model to study regional effects of pericyte loss on brain vascular and neuronal functions. This model could be a useful tool for future studies directed at understanding the role of pericytes in the pathogenesis of neurological disorders associated with pericyte loss such as vascular dementia, Alzheimer's disease, amyotrophic lateral sclerosis, stroke and human immunodeficiency virus-associated neurocognitive disorder.
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Affiliation(s)
- Angeliki Maria Nikolakopoulou
- Department of Physiology and Biophysics and Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Zhen Zhao
- Department of Physiology and Biophysics and Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Axel Montagne
- Department of Physiology and Biophysics and Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Berislav V. Zlokovic
- Department of Physiology and Biophysics and Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- * E-mail:
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68
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Fantauzzo KA, Soriano P. PDGFRβ regulates craniofacial development through homodimers and functional heterodimers with PDGFRα. Genes Dev 2016; 30:2443-2458. [PMID: 27856617 PMCID: PMC5131783 DOI: 10.1101/gad.288746.116] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 10/19/2016] [Indexed: 01/01/2023]
Abstract
Craniofacial development is a complex morphogenetic process, disruptions in which result in highly prevalent human birth defects. While platelet-derived growth factor (PDGF) receptor α (PDGFRα) has well-documented functions in this process, the role of PDGFRβ in murine craniofacial development is not well established. We demonstrate that PDGFRα and PDGFRβ are coexpressed in the craniofacial mesenchyme of mid-gestation mouse embryos and that ablation of Pdgfrb in the neural crest lineage results in increased nasal septum width, delayed palatal shelf development, and subepidermal blebbing. Furthermore, we show that the two receptors genetically interact in this lineage, as double-homozygous mutant embryos exhibit an overt facial clefting phenotype more severe than that observed in either single-mutant embryo. We reveal a physical interaction between PDGFRα and PDGFRβ in the craniofacial mesenchyme and demonstrate that the receptors form functional heterodimers with distinct signaling properties. Our studies thus uncover a novel mode of signaling for the PDGF family during vertebrate development.
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Affiliation(s)
- Katherine A Fantauzzo
- Department of Cell Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Philippe Soriano
- Department of Cell Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
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69
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Rogers EM, Spracklen AJ, Bilancia CG, Sumigray KD, Allred SC, Nowotarski SH, Schaefer KN, Ritchie BJ, Peifer M. Abelson kinase acts as a robust, multifunctional scaffold in regulating embryonic morphogenesis. Mol Biol Cell 2016; 27:2613-31. [PMID: 27385341 PMCID: PMC4985262 DOI: 10.1091/mbc.e16-05-0292] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 06/20/2016] [Indexed: 11/16/2022] Open
Abstract
The importance of Abl kinase activity, the F-actin–binding site, and scaffolding ability in Abl’s many cell biological roles during Drosophila morphogenesis is examined. Abl is a robust multidomain scaffold with different protein motifs and activities contributing differentially to diverse cellular behaviors. Abelson family kinases (Abls) are key regulators of cell behavior and the cytoskeleton during development and in leukemia. Abl’s SH3, SH2, and tyrosine kinase domains are joined via a linker to an F-actin–binding domain (FABD). Research on Abl’s roles in cell culture led to several hypotheses for its mechanism of action: 1) Abl phosphorylates other proteins, modulating their activity, 2) Abl directly regulates the cytoskeleton via its cytoskeletal interaction domains, and/or 3) Abl is a scaffold for a signaling complex. The importance of these roles during normal development remains untested. We tested these mechanistic hypotheses during Drosophila morphogenesis using a series of mutants to examine Abl’s many cell biological roles. Strikingly, Abl lacking the FABD fully rescued morphogenesis, cell shape change, actin regulation, and viability, whereas kinase-dead Abl, although reduced in function, retained substantial rescuing ability in some but not all Abl functions. We also tested the function of four conserved motifs in the linker region, revealing a key role for a conserved PXXP motif known to bind Crk and Abi. We propose that Abl acts as a robust multidomain scaffold with different protein motifs and activities contributing differentially to diverse cellular behaviors.
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Affiliation(s)
- Edward M Rogers
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Andrew J Spracklen
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Colleen G Bilancia
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Kaelyn D Sumigray
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - S Colby Allred
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Stephanie H Nowotarski
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Kristina N Schaefer
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Benjamin J Ritchie
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Mark Peifer
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
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70
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Abstract
The fibroblast growth factor (Fgf) family of ligands and receptor tyrosine kinases is required throughout embryonic and postnatal development and also regulates multiple homeostatic functions in the adult. Aberrant Fgf signaling causes many congenital disorders and underlies multiple forms of cancer. Understanding the mechanisms that govern Fgf signaling is therefore important to appreciate many aspects of Fgf biology and disease. Here we review the mechanisms of Fgf signaling by focusing on genetic strategies that enable in vivo analysis. These studies support an important role for Erk1/2 as a mediator of Fgf signaling in many biological processes but have also provided strong evidence for additional signaling pathways in transmitting Fgf signaling in vivo.
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Affiliation(s)
- J Richard Brewer
- Department of Developmental and Regenerative Biology, Tisch Cancer Institute, Icahn School of Medicine at Mt. Sinai, New York, New York 10029, USA
| | - Pierre Mazot
- Department of Developmental and Regenerative Biology, Tisch Cancer Institute, Icahn School of Medicine at Mt. Sinai, New York, New York 10029, USA
| | - Philippe Soriano
- Department of Developmental and Regenerative Biology, Tisch Cancer Institute, Icahn School of Medicine at Mt. Sinai, New York, New York 10029, USA
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71
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Zhao Z, Nelson AR, Betsholtz C, Zlokovic BV. Establishment and Dysfunction of the Blood-Brain Barrier. Cell 2016; 163:1064-1078. [PMID: 26590417 DOI: 10.1016/j.cell.2015.10.067] [Citation(s) in RCA: 1065] [Impact Index Per Article: 133.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Indexed: 12/11/2022]
Abstract
Structural and functional brain connectivity, synaptic activity, and information processing require highly coordinated signal transduction between different cell types within the neurovascular unit and intact blood-brain barrier (BBB) functions. Here, we examine the mechanisms regulating the formation and maintenance of the BBB and functions of BBB-associated cell types. Furthermore, we discuss the growing evidence associating BBB breakdown with the pathogenesis of inherited monogenic neurological disorders and complex multifactorial diseases, including Alzheimer's disease.
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Affiliation(s)
- Zhen Zhao
- Department of Physiology and Biophysics and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90089, USA
| | - Amy R Nelson
- Department of Physiology and Biophysics and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90089, USA
| | - Christer Betsholtz
- Department of Immunology, Genetics, and Pathology, Rudbeck Laboratory, 75185 Uppsala, Sweden
| | - Berislav V Zlokovic
- Department of Physiology and Biophysics and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90089, USA.
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72
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Trost A, Lange S, Schroedl F, Bruckner D, Motloch KA, Bogner B, Kaser-Eichberger A, Strohmaier C, Runge C, Aigner L, Rivera FJ, Reitsamer HA. Brain and Retinal Pericytes: Origin, Function and Role. Front Cell Neurosci 2016; 10:20. [PMID: 26869887 PMCID: PMC4740376 DOI: 10.3389/fncel.2016.00020] [Citation(s) in RCA: 158] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 01/18/2016] [Indexed: 12/13/2022] Open
Abstract
Pericytes are specialized mural cells located at the abluminal surface of capillary blood vessels, embedded within the basement membrane. In the vascular network these multifunctional cells fulfil diverse functions, which are indispensable for proper homoeostasis. They serve as microvascular stabilizers, are potential regulators of microvascular blood flow and have a central role in angiogenesis, as they for example regulate endothelial cell proliferation. Furthermore, pericytes, as part of the neurovascular unit, are a major component of the blood-retina/brain barrier. CNS pericytes are a heterogenic cell population derived from mesodermal and neuro-ectodermal germ layers acting as modulators of stromal and niche environmental properties. In addition, they display multipotent differentiation potential making them an intriguing target for regenerative therapies. Pericyte-deficiencies can be cause or consequence of many kinds of diseases. In diabetes, for instance, pericyte-loss is a severe pathological process in diabetic retinopathy (DR) with detrimental consequences for eye sight in millions of patients. In this review, we provide an overview of our current understanding of CNS pericyte origin and function, with a special focus on the retina in the healthy and diseased. Finally, we highlight the role of pericytes in de- and regenerative processes.
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Affiliation(s)
- Andrea Trost
- Research Program for Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, University Clinic of Ophthalmology and OptometrySalzburg, Austria; Molecular Regenerative Medicine, Paracelsus Medical UniversitySalzburg, Austria
| | - Simona Lange
- Molecular Regenerative Medicine, Paracelsus Medical UniversitySalzburg, Austria; Spinal Cord Injury and Tissue Regeneration Center Salzburg, Paracelsus Medical University SalzburgSalzburg, Austria
| | - Falk Schroedl
- Research Program for Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, University Clinic of Ophthalmology and OptometrySalzburg, Austria; Anatomy, Paracelsus Medical UniversitySalzburg, Austria
| | - Daniela Bruckner
- Research Program for Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, University Clinic of Ophthalmology and Optometry Salzburg, Austria
| | - Karolina A Motloch
- Research Program for Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, University Clinic of Ophthalmology and Optometry Salzburg, Austria
| | - Barbara Bogner
- Research Program for Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, University Clinic of Ophthalmology and Optometry Salzburg, Austria
| | - Alexandra Kaser-Eichberger
- Research Program for Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, University Clinic of Ophthalmology and Optometry Salzburg, Austria
| | - Clemens Strohmaier
- Research Program for Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, University Clinic of Ophthalmology and Optometry Salzburg, Austria
| | - Christian Runge
- Research Program for Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, University Clinic of Ophthalmology and Optometry Salzburg, Austria
| | - Ludwig Aigner
- Spinal Cord Injury and Tissue Regeneration Center Salzburg, Paracelsus Medical University SalzburgSalzburg, Austria; Anatomy, Paracelsus Medical UniversitySalzburg, Austria
| | - Francisco J Rivera
- Spinal Cord Injury and Tissue Regeneration Center Salzburg, Paracelsus Medical University SalzburgSalzburg, Austria; Anatomy, Paracelsus Medical UniversitySalzburg, Austria
| | - Herbert A Reitsamer
- Research Program for Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, University Clinic of Ophthalmology and OptometrySalzburg, Austria; Anatomy, Paracelsus Medical UniversitySalzburg, Austria
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73
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Tsai HH, Niu J, Munji R, Davalos D, Chang J, Zhang H, Tien AC, Kuo CJ, Chan JR, Daneman R, Fancy SPJ. Oligodendrocyte precursors migrate along vasculature in the developing nervous system. Science 2016; 351:379-84. [PMID: 26798014 PMCID: PMC5472053 DOI: 10.1126/science.aad3839] [Citation(s) in RCA: 289] [Impact Index Per Article: 36.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Oligodendrocytes myelinate axons in the central nervous system and develop from oligodendrocyte precursor cells (OPCs) that must first migrate extensively during brain and spinal cord development. We show that OPCs require the vasculature as a physical substrate for migration. We observed that OPCs of the embryonic mouse brain and spinal cord, as well as the human cortex, emerge from progenitor domains and associate with the abluminal endothelial surface of nearby blood vessels. Migrating OPCs crawl along and jump between vessels. OPC migration in vivo was disrupted in mice with defective vascular architecture but was normal in mice lacking pericytes. Thus, physical interactions with the vascular endothelium are required for OPC migration. We identify Wnt-Cxcr4 (chemokine receptor 4) signaling in regulation of OPC-endothelial interactions and propose that this signaling coordinates OPC migration with differentiation.
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Affiliation(s)
- Hui-Hsin Tsai
- Department of Pediatrics, University of California at San Francisco (UCSF), San Francisco, CA 94158, USA
| | - Jianqin Niu
- Department of Pediatrics, University of California at San Francisco (UCSF), San Francisco, CA 94158, USA
| | - Roeben Munji
- Departments of Pharmacology and Neuroscience, University of California at San Diego (UCSD), San Diego, CA 92093, USA
| | - Dimitrios Davalos
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195, USA
| | - Junlei Chang
- Division of Hematology, Department of Medicine, Stanford University, Stanford, CA 94305, USA
| | - Haijing Zhang
- Division of Hematology, Department of Medicine, Stanford University, Stanford, CA 94305, USA. Department of Urology, Cleveland Clinic Foundation, Cleveland, OH 44195, USA. Howard Hughes Medical Institute (HHMI), Chevy Chase, MD 20815, USA. Duke University School of Medicine, Durham, NC 27710, USA
| | - An-Chi Tien
- Department of Pediatrics, University of California at San Francisco (UCSF), San Francisco, CA 94158, USA
| | - Calvin J Kuo
- Division of Hematology, Department of Medicine, Stanford University, Stanford, CA 94305, USA
| | - Jonah R Chan
- Department of Neurology, UCSF, San Francisco, CA 94158, USA
| | - Richard Daneman
- Departments of Pharmacology and Neuroscience, University of California at San Diego (UCSD), San Diego, CA 92093, USA
| | - Stephen P J Fancy
- Department of Pediatrics, University of California at San Francisco (UCSF), San Francisco, CA 94158, USA. Department of Neurology, UCSF, San Francisco, CA 94158, USA. Division of Neonatology, UCSF, San Francisco, CA 94158, USA. Newborn Brain Research Institute, UCSF, San Francisco, CA 94158, USA.
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74
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Vasudevan HN, Soriano P. A Thousand and One Receptor Tyrosine Kinases: Wherein the Specificity? Curr Top Dev Biol 2016; 117:393-404. [PMID: 26969991 DOI: 10.1016/bs.ctdb.2015.10.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Over 20 years ago, a series of seminal studies in PC12 neurons provided a framework for how receptor tyrosine kinases generate many different outcomes despite activating a set of shared intracellular pathways. In this essay, we revisit the question of receptor tyrosine kinase specificity. We first examine the relationship between receptor phosphorylation and intracellular pathway activation. We then consider the mechanisms through which signaling dynamics encode distinct cellular outcomes and finally discuss how two different receptors drive divergent transcriptional responses within the same developmental context. Establishing the key parameters that dictate the response to growth factor stimulation is critical for determining how receptor tyrosine kinases orchestrate development, an essential prerequisite for understanding the pathological consequences when such signaling processes go awry.
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Affiliation(s)
- Harish N Vasudevan
- Department of Developmental and Regenerative Biology, The Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, USA
| | - Philippe Soriano
- Department of Developmental and Regenerative Biology, The Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, USA.
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75
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Abstract
In autoimmune neurologic disorders, the blood-brain barrier (BBB) plays a central role in immunopathogenesis, since this vascular interface is an entry path for cells and effector molecules of the peripheral immune system to reach the target organ, the central nervous system (CNS). The BBB's unique anatomic structure and the tightly regulated interplay of its cellular and acellular components allow for maintenance of brain homeostasis, regulation of influx and efflux, and protection from harm; these ensure an optimal environment for the neuronal network to function properly. In both health and disease, the BBB acts as mediator between the periphery and the CNS. For example, immune cell trafficking through the cerebral vasculature is essential to clear microbes or cell debris from neural tissues, while poorly regulated cellular transmigration can underlie or worsen CNS pathology. In this chapter, we focus on the specialized multicellular structure and function of the BBB/neurovascular unit and discuss how BBB breakdown can precede or be a consequence of neuroinflammation. We introduce the blood-cerebrospinal fluid barrier and include a brief aside about evolutionary aspects of barrier formation and refinements. Lastly, since restoration of barrier function is considered key to ameliorate neurologic disease, we speculate about new therapeutic avenues to repair a damaged BBB.
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Affiliation(s)
| | - Ajay Verma
- Biomarkers and Experimental Medicine, Biogen, Cambridge, MA, USA
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76
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Brewer JR, Molotkov A, Mazot P, Hoch RV, Soriano P. Fgfr1 regulates development through the combinatorial use of signaling proteins. Genes Dev 2015; 29:1863-74. [PMID: 26341559 PMCID: PMC4573858 DOI: 10.1101/gad.264994.115] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Brewer et al. engineered an allelic series of knock-in point mutations designed to disrupt Fgfr1 signaling functions individually and in combination. They found that, in addition to Frs2, Crk proteins and Plcγ also contribute to Erk1/2 activation. Disruption of all known signaling functions diminished Erk1/2 and Plcγ activation but did not recapitulate the peri-implantation Fgfr1-null phenotype. Fibroblast growth factor (Fgf) signaling governs multiple processes important in development and disease. Many lines of evidence have implicated Erk1/2 signaling induced through Frs2 as the predominant effector pathway downstream from Fgf receptors (Fgfrs), but these receptors can also signal through other mechanisms. To explore the functional significance of the full range of signaling downstream from Fgfrs in mice, we engineered an allelic series of knock-in point mutations designed to disrupt Fgfr1 signaling functions individually and in combination. Analysis of each mutant indicates that Frs2 binding to Fgfr1 has the most pleiotropic functions in development but also that the receptor uses multiple proteins additively in vivo. In addition to Frs2, Crk proteins and Plcγ also contribute to Erk1/2 activation, affecting axis elongation and craniofacial and limb development and providing a biochemical mechanism for additive signaling requirements. Disruption of all known signaling functions diminished Erk1/2 and Plcγ activation but did not recapitulate the peri-implantation Fgfr1-null phenotype. This suggests that Erk1/2-independent signaling pathways are functionally important for Fgf signaling in vivo.
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Affiliation(s)
- J Richard Brewer
- Department of Developmental and Regenerative Biology, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Andrei Molotkov
- Department of Developmental and Regenerative Biology, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Pierre Mazot
- Department of Developmental and Regenerative Biology, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Renée V Hoch
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA
| | - Philippe Soriano
- Department of Developmental and Regenerative Biology, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA; Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA
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Vanlandewijck M, Lebouvier T, Andaloussi Mäe M, Nahar K, Hornemann S, Kenkel D, Cunha SI, Lennartsson J, Boss A, Heldin CH, Keller A, Betsholtz C. Functional Characterization of Germline Mutations in PDGFB and PDGFRB in Primary Familial Brain Calcification. PLoS One 2015; 10:e0143407. [PMID: 26599395 PMCID: PMC4658112 DOI: 10.1371/journal.pone.0143407] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 09/25/2015] [Indexed: 12/17/2022] Open
Abstract
Primary Familial Brain Calcification (PFBC), a neurodegenerative disease characterized by progressive pericapillary calcifications, has recently been linked to heterozygous mutations in PDGFB and PDGFRB genes. Here, we functionally analyzed several of these mutations in vitro. All six analyzed PDGFB mutations led to complete loss of PDGF-B function either through abolished protein synthesis or through defective binding and/or stimulation of PDGF-Rβ. The three analyzed PDGFRB mutations had more diverse consequences. Whereas PDGF-Rβ autophosphorylation was almost totally abolished in the PDGFRB L658P mutation, the two sporadic PDGFRB mutations R987W and E1071V caused reductions in protein levels and specific changes in the intensity and kinetics of PLCγ activation, respectively. Since at least some of the PDGFB mutations were predicted to act through haploinsufficiency, we explored the consequences of reduced Pdgfb or Pdgfrb transcript and protein levels in mice. Heterozygous Pdgfb or Pdgfrb knockouts, as well as double Pdgfb+/-;Pdgfrb+/- mice did not develop brain calcification, nor did Pdgfrbredeye/redeye mice, which show a 90% reduction of PDGFRβ protein levels. In contrast, Pdgfbret/ret mice, which have altered tissue distribution of PDGF-B protein due to loss of a proteoglycan binding motif, developed brain calcifications. We also determined pericyte coverage in calcification-prone and non-calcification-prone brain regions in Pdgfbret/ret mice. Surprisingly and contrary to our hypothesis, we found that the calcification-prone brain regions in Pdgfbret/ret mice model had a higher pericyte coverage and a more intact blood-brain barrier (BBB) compared to non-calcification-prone brain regions. While our findings provide clear evidence that loss-of-function mutations in PDGFB or PDGFRB cause PFBC, they also demonstrate species differences in the threshold levels of PDGF-B/PDGF-Rβ signaling that protect against small-vessel calcification in the brain. They further implicate region-specific susceptibility factor(s) in PFBC pathogenesis that are distinct from pericyte and BBB deficiency.
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Affiliation(s)
- Michael Vanlandewijck
- Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Dag Hammarskjölds väg 20, Uppsala 75185, Sweden
- Integrated Cardio Metabolic Centre (ICMC), Karolinska Institute, Novum, SE-141 57 Huddinge, Stockholm, Sweden
| | - Thibaud Lebouvier
- Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Dag Hammarskjölds väg 20, Uppsala 75185, Sweden
| | - Maarja Andaloussi Mäe
- Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Dag Hammarskjölds väg 20, Uppsala 75185, Sweden
| | - Khayrun Nahar
- Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Dag Hammarskjölds väg 20, Uppsala 75185, Sweden
| | - Simone Hornemann
- Institute of Neuropathology, University Hospital Zürich, Zürich University, CH-8091 Zürich, Switzerland
| | - David Kenkel
- Institute of Diagnostic and Interventional Radiology, University Hospital Zürich, Zürich University, CH-8091 Zürich, Switzerland
| | - Sara I. Cunha
- Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Dag Hammarskjölds väg 20, Uppsala 75185, Sweden
- Ludwig Institute for Cancer Research, Science for Life Laboratory, Uppsala University, Box 595, SE-75124, Uppsala, Sweden
| | - Johan Lennartsson
- Ludwig Institute for Cancer Research, Science for Life Laboratory, Uppsala University, Box 595, SE-75124, Uppsala, Sweden
| | - Andreas Boss
- Institute of Diagnostic and Interventional Radiology, University Hospital Zürich, Zürich University, CH-8091 Zürich, Switzerland
| | - Carl-Henrik Heldin
- Ludwig Institute for Cancer Research, Science for Life Laboratory, Uppsala University, Box 595, SE-75124, Uppsala, Sweden
| | - Annika Keller
- Division of Neurosurgery, University Hospital Zürich, Zürich University, CH-8091 Zürich, Switzerland
| | - Christer Betsholtz
- Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Dag Hammarskjölds väg 20, Uppsala 75185, Sweden
- * E-mail:
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Alluri H, Wiggins-Dohlvik K, Davis ML, Huang JH, Tharakan B. Blood-brain barrier dysfunction following traumatic brain injury. Metab Brain Dis 2015; 30:1093-104. [PMID: 25624154 DOI: 10.1007/s11011-015-9651-7] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 01/13/2015] [Indexed: 01/24/2023]
Abstract
Traumatic brain injury is a serious cause of morbidity and mortality worldwide. After traumatic brain injury, the blood-brain barrier, the protective barrier between the brain and the intravascular compartment, becomes dysfunctional, leading to leakage of proteins, fluid, and transmigration of immune cells. As this leakage has profound clinical implications, including edema formation, elevated intracranial pressure and decreased perfusion pressure, much interest has been paid to better understanding the mechanisms responsible for these events. Various molecular pathways and numerous mediators have been found to be involved in the intricate process of regulating blood-brain barrier permeability following traumatic brain injury. This review provides an update to the existing knowledge about the various pathophysiological pathways and advancements in the field of blood-brain barrier dysfunction and hyperpermeability following traumatic brain injury, including the role of various tight junction proteins involved in blood-brain barrier integrity and regulation. We also address pitfalls of existing systems and propose strategies to improve the various debilitating functional deficits caused by this progressive epidemic.
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Affiliation(s)
- Himakarnika Alluri
- Department of Surgery, Baylor Scott & White Health & Texas A&M University Health Science Center, College of Medicine, 702 S.W. H.K. Dodgen Loop, Temple, TX, 76504, USA
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Sagare AP, Sweeney MD, Makshanoff J, Zlokovic BV. Shedding of soluble platelet-derived growth factor receptor-β from human brain pericytes. Neurosci Lett 2015; 607:97-101. [PMID: 26407747 DOI: 10.1016/j.neulet.2015.09.025] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 09/19/2015] [Accepted: 09/21/2015] [Indexed: 10/23/2022]
Abstract
Platelet-derived growth factor receptor-β (PDGFRβ) is expressed in the brain by vascular mural cells-brain capillary pericytes and arterial vascular smooth muscle cells (VSMCs). Recent evidence shows that blood-brain barrier (BBB) disruption and increased permeability, especially in the hippocampus, positively correlates with elevated levels of soluble PDGFRβ (sPDGFRβ) in cerebrospinal fluid (CSF) in patients with mild dementia. To determine which vascular cell type(s) contributes to increased sPDGFRβ in CSF, we compared PDGFRβ expression and sPDGFRβ shedding in response to injury in early passage primary cultures of human brain pericytes, brain arterial VSMCs, and brain endothelial cells. PDGFRβ protein was undetectable in endothelial cells, but was found both in pericytes and VSMCs. PDGFRβ relative protein abundance was by 4.2-fold (p<0.05) higher in pericytes compared to VSMCs. Hypoxia (1% O2) or amyloid-β peptide (25 μM) compared to normoxia (21% O2) both increased over 48 h shedding of sPDGFRβ and its levels in the culture medium from pericytes cultures, but not from VSMCs cultures, by 4.3-fold and 4.6-fold, respectively, compared to the basal sPDGFRβ levels in the medium (1.43±0.15 ng/ml). This was associated with the corresponding loss of cell-associated PDGFRβ from pericytes and no change in cellular levels of PDGFRβ in VSMCs. Thus, sPDGFRβ is a biomarker of pericyte injury, and elevated sPDGFRβ levels in biofluids in patients with dementia and/or other neurodegenerative disorders likely reflects pericyte injury, which supports the potential for sPDGFRβ to be developed and validated as a biomarker of brain pericyte injury and BBB dysfunction.
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Affiliation(s)
- Abhay P Sagare
- Department of Physiology and Biophysics, Center for Neurodegeneration and Regeneration, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Melanie D Sweeney
- Department of Physiology and Biophysics, Center for Neurodegeneration and Regeneration, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Jacob Makshanoff
- Department of Physiology and Biophysics, Center for Neurodegeneration and Regeneration, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Berislav V Zlokovic
- Department of Physiology and Biophysics, Center for Neurodegeneration and Regeneration, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
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Winkler EA, Sagare AP, Zlokovic BV. The pericyte: a forgotten cell type with important implications for Alzheimer's disease? Brain Pathol 2015; 24:371-86. [PMID: 24946075 DOI: 10.1111/bpa.12152] [Citation(s) in RCA: 192] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 05/13/2014] [Indexed: 12/13/2022] Open
Abstract
Pericytes are cells in the blood-brain barrier (BBB) that degenerate in Alzheimer's disease (AD), a neurodegenerative disorder characterized by early neurovascular dysfunction, elevation of amyloid β-peptide (Aβ), tau pathology and neuronal loss, leading to progressive cognitive decline and dementia. Pericytes are uniquely positioned within the neurovascular unit between endothelial cells of brain capillaries, astrocytes and neurons. Recent studies have shown that pericytes regulate key neurovascular functions including BBB formation and maintenance, vascular stability and angioarchitecture, regulation of capillary blood flow, and clearance of toxic cellular by-products necessary for normal functioning of the central nervous system (CNS). Here, we review the concept of the neurovascular unit and neurovascular functions of CNS pericytes. Next, we discuss vascular contributions to AD and review new roles of pericytes in the pathogenesis of AD such as vascular-mediated Aβ-independent neurodegeneration, regulation of Aβ clearance and contributions to tau pathology, neuronal loss and cognitive decline. We conclude that future studies should focus on molecular mechanisms and pathways underlying aberrant signal transduction between pericytes and its neighboring cells within the neurovascular unit, that is, endothelial cells, astrocytes and neurons, which could represent potential therapeutic targets to control pericyte degeneration in AD and the resulting secondary vascular and neuronal degeneration.
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Affiliation(s)
- Ethan A Winkler
- Zilkha Neurogenetic Institute, University of Southern California Keck School of Medicine, Los Angeles, CA; Department of Neurosurgery, University of California San Francisco, San Francisco, CA
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Betsholtz C, Keller A. PDGF, pericytes and the pathogenesis of idiopathic basal ganglia calcification (IBGC). Brain Pathol 2015; 24:387-95. [PMID: 24946076 DOI: 10.1111/bpa.12158] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 05/13/2014] [Indexed: 01/09/2023] Open
Abstract
Platelet-derived growth factors (PDGFs) are important mitogens for various types of mesenchymal cells, and as such, they exert critical functions during organogenesis in mammalian embryonic and early postnatal development. Increased or ectopic PDGF activity may also cause or contribute to diseases such as cancer and tissue fibrosis. Until recently, no loss-of-function (LOF) mutations in PDGF or PDGF receptor genes were reported as causally linked to a human disease. This changed in 2013 when reports appeared on presumed LOF mutations in the genes encoding PDGF-B and its receptor PDGF receptor-beta (PDGF-Rβ) in familial idiopathic basal ganglia calcification (IBGC), a brain disease characterized by anatomically localized calcifications in or near the blood microvessels. Here, we review PDGF-B and PDGF-Rβ biology with special reference to their functions in brain-blood vessel development, pericyte recruitment and the regulation of the blood-brain barrier. We also discuss various scenarios for IBGC pathogenesis suggested by observations in patients and genetically engineered animal models of the disease.
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Affiliation(s)
- Christer Betsholtz
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
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Hurtado R, Zewdu R, Mtui J, Liang C, Aho R, Kurylo C, Selleri L, Herzlinger D. Pbx1-dependent control of VMC differentiation kinetics underlies gross renal vascular patterning. Development 2015; 142:2653-64. [PMID: 26138478 DOI: 10.1242/dev.124776] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 06/09/2015] [Indexed: 12/29/2022]
Abstract
The architecture of an organ's vascular bed subserves its physiological function and metabolic demands. However, the mechanisms underlying gross vascular patterning remain elusive. Using intravital dye labeling and 3D imaging, we discovered that systems-level vascular patterning in the kidney is dependent on the kinetics of vascular mural cell (VMC) differentiation. Conditional ablation of the TALE transcription factor Pbx1 in renal VMC progenitors in the mouse led to the premature upregulation of PDGFRβ, a master initiator of VMC-blood vessel association. This precocious VMC differentiation resulted in nonproductive angiogenesis, abnormal renal arterial tree patterning and neonatal death consistent with kidney dysfunction. Notably, we establish that Pbx1 directly represses Pdgfrb, and demonstrate that decreased Pdgfrb dosage in conditional Pbx1 mutants substantially rescues vascular patterning defects and neonatal survival. These findings identify, for the first time, an in vivo transcriptional regulator of PDGFRβ, and reveal a previously unappreciated role for VMCs in systems-level vascular patterning.
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Affiliation(s)
- Romulo Hurtado
- Department of Physiology and Biophysics, Weill Cornell Medical College, New York, NY 10065, USA
| | - Rediet Zewdu
- Department of Cell and Developmental Biology, Weill Cornell Medical College, New York, NY 10065, USA
| | - James Mtui
- Department of Physiology and Biophysics, Weill Cornell Medical College, New York, NY 10065, USA
| | - Cindy Liang
- Department of Physiology and Biophysics, Weill Cornell Medical College, New York, NY 10065, USA
| | - Robert Aho
- Department of Cell and Developmental Biology, Weill Cornell Medical College, New York, NY 10065, USA
| | - Chad Kurylo
- Department of Physiology and Biophysics, Weill Cornell Medical College, New York, NY 10065, USA
| | - Licia Selleri
- Department of Cell and Developmental Biology, Weill Cornell Medical College, New York, NY 10065, USA
| | - Doris Herzlinger
- Department of Physiology and Biophysics, Weill Cornell Medical College, New York, NY 10065, USA
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Vasudevan HN, Mazot P, He F, Soriano P. Receptor tyrosine kinases modulate distinct transcriptional programs by differential usage of intracellular pathways. eLife 2015; 4. [PMID: 25951516 PMCID: PMC4450512 DOI: 10.7554/elife.07186] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 05/06/2015] [Indexed: 11/27/2022] Open
Abstract
Receptor tyrosine kinases (RTKs) signal through shared intracellular pathways yet mediate distinct outcomes across many cell types. To investigate the mechanisms underlying RTK specificity in craniofacial development, we performed RNA-seq to delineate the transcriptional response to platelet-derived growth factor (PDGF) and fibroblast growth factor (FGF) signaling in mouse embryonic palatal mesenchyme cells. While the early gene expression profile induced by both growth factors is qualitatively similar, the late response is divergent. Comparing the effect of MEK (Mitogen/Extracellular signal-regulated kinase) and PI3K (phosphoinositide-3-kinase) inhibition, we find the FGF response is MEK dependent, while the PDGF response is PI3K dependent. Furthermore, FGF promotes proliferation but PDGF favors differentiation. Finally, we demonstrate overlapping domains of PDGF-PI3K signaling and osteoblast differentiation in the palate and increased osteogenesis in FGF mutants, indicating this differentiation circuit is conserved in vivo. Our results identify distinct responses to PDGF and FGF and provide insight into the mechanisms encoding RTK specificity. DOI:http://dx.doi.org/10.7554/eLife.07186.001 Cells produce many different proteins that play a variety of important roles. For example, proteins called receptor tyrosine kinases can detect particular molecules and send signals to other parts of the cell to regulate the activity (or “expression”) of genes involved in cell division, movement, and other processes. Humans have 58 receptor tyrosine kinases, and defects in these proteins have been linked to diseases such as cancer and diabetes. However, many different receptors regulate the activities of shared sets of genes, so it is not clear how an individual receptor can specifically control the genes involved in a particular process. Two receptor tyrosine kinases called PDGFR and FGFR are crucial for the development of the face, palate, and head in humans and other animals. Vasudevan et al. used a technique called RNA-sequencing to find out which genes are regulated by these receptors in mouse palate cells. The experiments show that there is a common set of genes whose activities change quickly—within 1 hour—in response to the activation of either PDGFR or FGFR. However, several hours later, cells in which PDGFR is activated have different patterns of gene expression compared to those with active FGFR. Vasudevan et al. also found that FGFR promotes cell division, while PDGFR promotes the changing of palate cells into different types with more specialized roles. These different outcomes arise because PDGFR and FGFR use different signaling pathways that involve distinct proteins. For example, a protein called PI3K is critical for changes in gene expression in response to PDGFR but not FGFR. These results suggest that PGDRF and FGFR control different cellular processes in the palate by sending distinct signals into the cell. Understanding the receptor tyrosine kinases and the networks of genes they activate will help us to identify the signals that are important for other processes, such as the development of the face. DOI:http://dx.doi.org/10.7554/eLife.07186.002
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Affiliation(s)
- Harish N Vasudevan
- Department of Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, United States
| | - Pierre Mazot
- Department of Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, United States
| | - Fenglei He
- Department of Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, United States
| | - Philippe Soriano
- Department of Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, United States
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RasGAP Promotes Autophagy and Thereby Suppresses Platelet-Derived Growth Factor Receptor-Mediated Signaling Events, Cellular Responses, and Pathology. Mol Cell Biol 2015; 35:1673-85. [PMID: 25733681 DOI: 10.1128/mcb.01248-14] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 02/24/2015] [Indexed: 11/20/2022] Open
Abstract
Platelet-derived growth factors (PDGFs) and their receptors (PDGFRs) make profound contributions to both physiology and pathology. While it is widely believed that direct (PDGF-mediated) activation is the primary mode of activating PDGFRs, the discovery that they can also be activated indirectly begs the question of the relevance of the indirect mode of activating PDGFRs. In the context of a blinding eye disease, indirect activation of PDGFRα results in persistent signaling, which suppresses the level of p53 and thereby promotes viability of cells that drive pathogenesis. Under the same conditions, PDGFRβ fails to undergo indirect activation. In this paper, we report that RasGAP (GTPase-activating protein of Ras) prevented indirect activation of PDGFRβ. RasGAP, which associates with PDGFRβ but not PDGFRα, reduced the level of mitochondrion-derived reactive oxygen species, which are required for enduring activation of PDGFRs. Furthermore, preventing PDGFRβ from associating with RasGAP allowed it to signal enduringly and drive pathogenesis of a blinding eye disease. These results indicate a previously unappreciated role of RasGAP in antagonizing indirect activation of PDGFRβ, define the underlying mechanism, and raise the possibility that PDGFRβ-mediated diseases involve indirect activation of PDGFRβ.
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85
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Hill J, Rom S, Ramirez SH, Persidsky Y. Emerging roles of pericytes in the regulation of the neurovascular unit in health and disease. J Neuroimmune Pharmacol 2014; 9:591-605. [PMID: 25119834 PMCID: PMC4209199 DOI: 10.1007/s11481-014-9557-x] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Accepted: 07/10/2014] [Indexed: 12/14/2022]
Abstract
Pericytes of the central nervous system (CNS) are uniquely positioned within a multicellular structure termed the neurovascular unit (NVU) to provide crucial support to blood brain barrier (BBB) formation, maintenance, and stability. Numerous CNS diseases are associated with some aspect of BBB dysfunction. A dysfunction can manifest as one or multiple disruptions to any of the following barriers: physical, metabolic, immunological and transport barrier. A breach in the BBB can notably result in BBB hyper-permeability, endothelial activation and enhanced immune-endothelial interaction. How the BBB is regulated within this integrated unit remains largely unknown, especially as it relates to pericyte-endothelial interaction. We summarize the latest findings on pericyte origin, possible marker expression, and availability within different organ systems. We highlight pericyte-endothelial cell interactions, concentrating on extra- and intra- cellular signaling mechanisms linked to platelet derived growth factor-B, transforming growth factor -β, angiopoietins, Notch, and gap junctions. We discuss the role of pericytes in the NVU under inflammatory insult, focusing on how pericytes may indirectly affect leukocyte CNS infiltration, the direct role of pericyte-mediated basement membrane modifications, and immune responses. We review new findings of pericyte actions in CNS pathologies including Alzheimer's disease, stroke, multiple sclerosis, diabetic retinopathy, and HIV-1 infection. The uncovering of the regulatory role of pericytes on the BBB will provide key insight into how barrier integrity can be re-established during neuroinflammation.
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Affiliation(s)
- Jeremy Hill
- Department of Pathology and Laboratory Medicine, Temple University School of Medicine, Philadelphia PA
- Center for Substance Abuse Research, Temple University School of Medicine, Philadelphia PA
| | - Slava Rom
- Department of Pathology and Laboratory Medicine, Temple University School of Medicine, Philadelphia PA
- Center for Substance Abuse Research, Temple University School of Medicine, Philadelphia PA
| | - Servio H. Ramirez
- Department of Pathology and Laboratory Medicine, Temple University School of Medicine, Philadelphia PA
- Center for Substance Abuse Research, Temple University School of Medicine, Philadelphia PA
| | - Yuri Persidsky
- Department of Pathology and Laboratory Medicine, Temple University School of Medicine, Philadelphia PA
- Center for Substance Abuse Research, Temple University School of Medicine, Philadelphia PA
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Nakajima C, Haffner P, Goerke SM, Zurhove K, Adelmann G, Frotscher M, Herz J, Bock HH, May P. The lipoprotein receptor LRP1 modulates sphingosine-1-phosphate signaling and is essential for vascular development. Development 2014; 141:4513-25. [PMID: 25377550 DOI: 10.1242/dev.109124] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Low density lipoprotein receptor-related protein 1 (LRP1) is indispensable for embryonic development. Comparing different genetically engineered mouse models, we found that expression of Lrp1 is essential in the embryo proper. Loss of LRP1 leads to lethal vascular defects with lack of proper investment with mural cells of both large and small vessels. We further demonstrate that LRP1 modulates Gi-dependent sphingosine-1-phosphate (S1P) signaling and integrates S1P and PDGF-BB signaling pathways, which are both crucial for mural cell recruitment, via its intracellular domain. Loss of LRP1 leads to a lack of S1P-dependent inhibition of RAC1 and loss of constraint of PDGF-BB-induced cell migration. Our studies thus identify LRP1 as a novel player in angiogenesis and in the recruitment and maintenance of mural cells. Moreover, they reveal an unexpected link between lipoprotein receptor and sphingolipid signaling that, in addition to angiogenesis during embryonic development, is of potential importance for other targets of these pathways, such as tumor angiogenesis and inflammatory processes.
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Affiliation(s)
- Chikako Nakajima
- Department of Medicine II, University Hospital and University of Freiburg, 79106 Freiburg, Germany Centre for Neurosciences, University Hospital and University of Freiburg, 79104 Freiburg, Germany Institute of Physiological Chemistry and Focus Program Translational Neuroscience (Adult Neurogenesis and Cellular Reprogramming), University Medical Center, Johannes Gutenberg University Mainz, 55128 Mainz, Germany Department of Gastroenterology, Hepatology and Infectiology, University Hospital of Düsseldorf, 40225 Düsseldorf, Germany
| | - Philipp Haffner
- Centre for Neurosciences, University Hospital and University of Freiburg, 79104 Freiburg, Germany
| | - Sebastian M Goerke
- Centre for Neurosciences, University Hospital and University of Freiburg, 79104 Freiburg, Germany Department of Plastic and Hand Surgery, University Hospital and University of Freiburg, 79106 Freiburg, Germany
| | - Kai Zurhove
- Department of Medicine II, University Hospital and University of Freiburg, 79106 Freiburg, Germany Centre for Neurosciences, University Hospital and University of Freiburg, 79104 Freiburg, Germany
| | - Giselind Adelmann
- Institute of Anatomy and Cell Biology, University Hospital and University of Freiburg, 79104 Freiburg, Germany
| | - Michael Frotscher
- Institute for Structural Neurobiology, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Joachim Herz
- Centre for Neurosciences, University Hospital and University of Freiburg, 79104 Freiburg, Germany Department for Molecular Genetics, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390, USA
| | - Hans H Bock
- Department of Medicine II, University Hospital and University of Freiburg, 79106 Freiburg, Germany Centre for Neurosciences, University Hospital and University of Freiburg, 79104 Freiburg, Germany Department of Gastroenterology, Hepatology and Infectiology, University Hospital of Düsseldorf, 40225 Düsseldorf, Germany
| | - Petra May
- Department of Medicine II, University Hospital and University of Freiburg, 79106 Freiburg, Germany Centre for Neurosciences, University Hospital and University of Freiburg, 79104 Freiburg, Germany Department of Gastroenterology, Hepatology and Infectiology, University Hospital of Düsseldorf, 40225 Düsseldorf, Germany
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87
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Naylor AJ, McGettrick HM, Maynard WD, May P, Barone F, Croft AP, Egginton S, Buckley CD. A differential role for CD248 (Endosialin) in PDGF-mediated skeletal muscle angiogenesis. PLoS One 2014; 9:e107146. [PMID: 25243742 PMCID: PMC4171374 DOI: 10.1371/journal.pone.0107146] [Citation(s) in RCA: 25] [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: 03/17/2014] [Accepted: 08/12/2014] [Indexed: 11/18/2022] Open
Abstract
CD248 (Endosialin) is a type 1 membrane protein involved in developmental and pathological angiogenesis through its expression on pericytes and regulation of PDGFRβ signalling. Here we explore the function of CD248 in skeletal muscle angiogenesis. Two distinct forms of capillary growth (splitting and sprouting) can be induced separately by increasing microcirculatory shear stress (chronic vasodilator treatment) or by inducing functional overload (extirpation of a synergistic muscle). We show that CD248 is present on pericytes in muscle and that CD248-/- mice have a specific defect in capillary sprouting. In contrast, splitting angiogenesis is independent of CD248 expression. Endothelial cells respond to pro-sprouting angiogenic stimulus by up-regulating gene expression for HIF1α, angiopoietin 2 and its receptor TEK, PDGF-B and its receptor PDGFRβ; this response did not occur following a pro-splitting angiogenic stimulus. In wildtype mice, defective sprouting angiogenesis could be mimicked by blocking PDGFRβ signalling using the tyrosine kinase inhibitor Imatinib mesylate. We conclude that CD248 is required for PDGFRβ-dependant capillary sprouting but not splitting angiogenesis, and identify a new role for CD248 expressed on pericytes in the early stages of physiological angiogenesis during muscle remodelling.
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MESH Headings
- Adrenergic alpha-1 Receptor Antagonists/pharmacology
- Angiopoietin-2/genetics
- Angiopoietin-2/metabolism
- Animals
- Antigens, CD/genetics
- Antigens, CD/metabolism
- Benzamides/pharmacology
- Capillaries/drug effects
- Capillaries/metabolism
- Hypoxia-Inducible Factor 1, alpha Subunit/genetics
- Hypoxia-Inducible Factor 1, alpha Subunit/metabolism
- Imatinib Mesylate
- Mice
- Mice, Knockout
- Muscle, Skeletal/blood supply
- Muscle, Skeletal/drug effects
- Muscle, Skeletal/metabolism
- Neoplasm Proteins/genetics
- Neoplasm Proteins/metabolism
- Neovascularization, Physiologic/drug effects
- Neovascularization, Physiologic/genetics
- Pericytes/drug effects
- Pericytes/metabolism
- Piperazines/pharmacology
- Platelet-Derived Growth Factor/metabolism
- Prazosin/pharmacology
- Protein Kinase Inhibitors/pharmacology
- Pyrimidines/pharmacology
- Receptors, Platelet-Derived Growth Factor/genetics
- Receptors, Platelet-Derived Growth Factor/metabolism
- Signal Transduction/drug effects
- Signal Transduction/genetics
- Up-Regulation/drug effects
- Up-Regulation/genetics
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Affiliation(s)
- Amy J. Naylor
- Rheumatology Research Group, Centre for Translational Inflammation Research, University of Birmingham, Birmingham, West Midlands, United Kingdom
| | - Helen M. McGettrick
- Rheumatology Research Group, Centre for Translational Inflammation Research, University of Birmingham, Birmingham, West Midlands, United Kingdom
- Systems Science for Health, University of Birmingham, Birmingham, West Midlands, United Kingdom
| | - William D. Maynard
- Rheumatology Research Group, Centre for Translational Inflammation Research, University of Birmingham, Birmingham, West Midlands, United Kingdom
| | - Philippa May
- Rheumatology Research Group, Centre for Translational Inflammation Research, University of Birmingham, Birmingham, West Midlands, United Kingdom
| | - Francesca Barone
- Rheumatology Research Group, Centre for Translational Inflammation Research, University of Birmingham, Birmingham, West Midlands, United Kingdom
| | - Adam P. Croft
- Rheumatology Research Group, Centre for Translational Inflammation Research, University of Birmingham, Birmingham, West Midlands, United Kingdom
| | - Stuart Egginton
- Faculty of Biological Sciences, University of Leeds, Leeds, West Yorkshire, United Kingdom
| | - Christopher D. Buckley
- Rheumatology Research Group, Centre for Translational Inflammation Research, University of Birmingham, Birmingham, West Midlands, United Kingdom
- Systems Science for Health, University of Birmingham, Birmingham, West Midlands, United Kingdom
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88
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Sanchez-Contreras M, Baker MC, Finch NA, Nicholson A, Wojtas A, Wszolek ZK, Ross OA, Dickson DW, Rademakers R. Genetic screening and functional characterization of PDGFRB mutations associated with basal ganglia calcification of unknown etiology. Hum Mutat 2014; 35:964-71. [PMID: 24796542 DOI: 10.1002/humu.22582] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 04/22/2014] [Indexed: 01/30/2023]
Abstract
Three causal genes for idiopathic basal ganglia calcification (IBGC) have been identified. Most recently, mutations in PDGFRB, encoding a member of the platelet-derived growth factor receptor family type β, and PDGFB, encoding PDGF-B, the specific ligand of PDGFRβ, were found implicating the PDGF-B/PDGFRβ pathway in abnormal brain calcification. In this study, we aimed to identify and study mutations in PDGFRB and PDGFB in a series of 26 patients from the Mayo Clinic Florida Brain Bank with moderate to severe basal ganglia calcification (BCG) of unknown etiology. No mutations in PDGFB were found. However, we identified one mutation in PDGFRB, p.R695C located in the tyrosine kinase domain, in one BGC patient. We further studied the function of p.R695C mutant PDGFRβ and two previously reported mutants, p.L658P and p.R987W PDGFRβ in cell culture. We show that, in response to PDGF-BB stimulation, the p.L658P mutation completely suppresses PDGFRβ autophosphorylation, whereas the p.R695C mutation results in partial loss of autophosphorylation. For the p.R987W mutation, our data suggest a different mechanism involving reduced protein levels. These genetic and functional studies provide the first insight into the pathogenic mechanisms associated with PDGFRB mutations and provide further support for a pathogenic role of PDGFRB mutations in BGC.
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89
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Zhou L, Sohet F, Daneman R. Purification and culture of central nervous system pericytes. Cold Spring Harb Protoc 2014; 2014:581-3. [PMID: 24890216 DOI: 10.1101/pdb.top070888] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Pericytes are found on the abluminal surface of endothelial tubes. The function of these cells is still being elucidated, but they have been shown to be important for development and maintenance of the blood-brain barrier, regulation of angiogenesis and capillary blood flow, and regulation of the neural response to injury and disease. Previously used methods to isolate pericytes have relied on negative selection and prolonged culture of microvessel cells and may lead to populations of pericytes contaminated by other neural cell types. We have developed an immunopanning protocol to specifically purify pericytes from capillaries in the rodent optic nerve. This method relies on a combination of negative and positive selection criteria and allows prospective, acute isolation of pericytes. Use of this method will facilitate studies of pericyte cell biology and function and pericyte-endothelial cell interactions.
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Affiliation(s)
- Lu Zhou
- Department of Neurobiology, Stanford University School of Medicine, Stanford, California 94305-5125
| | - Fabien Sohet
- Department of Anatomy, UCSF, San Francisco, California 94143-0452
| | - Richard Daneman
- Department of Anatomy, UCSF, San Francisco, California 94143-0452
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90
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Circulating fibronectin controls tumor growth. Neoplasia 2014; 15:925-38. [PMID: 23908593 DOI: 10.1593/neo.13762] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Revised: 05/21/2013] [Accepted: 05/23/2013] [Indexed: 01/01/2023] Open
Abstract
Fibronectin is ubiquitously expressed in the extracellular matrix, and experimental evidence has shown that it modulates blood vessel formation. The relative contribution of local and circulating fibronectin to blood vessel formation in vivo remains unknown despite evidence for unexpected roles of circulating fibronectin in various diseases. Using transgenic mouse models, we established that circulating fibronectin facilitates the growth of bone metastases by enhancing blood vessel formation and maturation. This effect is more relevant than that of fibronectin produced by endothelial cells and pericytes, which only exert a small additive effect on vessel maturation. Circulating fibronectin enhances its local production in tumors through a positive feedback loop and increases the amount of vascular endothelial growth factor (VEGF) retained in the matrix. Both fibronectin and VEGF then cooperate to stimulate blood vessel formation. Fibronectin content in the tumor correlates with the number of blood vessels and tumor growth in the mouse models. Consistent with these results, examination of three separate arrays from patients with breast and prostate cancers revealed that a high staining intensity for fibronectin in tumors is associated with increased mortality. These results establish that circulating fibronectin modulates blood vessel formation and tumor growth by modifying the amount of and the response to VEGF. Furthermore, determination of the fibronectin content can serve as a prognostic biomarker for breast and prostate cancers and possibly other cancers.
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91
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Noël LA, Arts FA, Montano-Almendras CP, Cox L, Gielen O, Toffalini F, Marbehant CY, Cools J, Demoulin JB. The tyrosine phosphatase SHP2 is required for cell transformation by the receptor tyrosine kinase mutants FIP1L1-PDGFRα and PDGFRα D842V. Mol Oncol 2014; 8:728-40. [PMID: 24618081 DOI: 10.1016/j.molonc.2014.02.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Revised: 01/27/2014] [Accepted: 02/05/2014] [Indexed: 02/06/2023] Open
Abstract
Activated forms of the platelet derived growth factor receptor alpha (PDGFRα) have been described in various tumors, including FIP1L1-PDGFRα in patients with myeloproliferative diseases associated with hypereosinophilia and the PDGFRα(D842V) mutant in gastrointestinal stromal tumors and inflammatory fibroid polyps. To gain a better insight into the signal transduction mechanisms of PDGFRα oncogenes, we mutated twelve potentially phosphorylated tyrosine residues of FIP1L1-PDGFRα and identified three mutations that affected cell proliferation. In particular, mutation of tyrosine 720 in FIP1L1-PDGFRα or PDGFRα(D842V) inhibited cell growth and blocked ERK signaling in Ba/F3 cells. This mutation also decreased myeloproliferation in transplanted mice and the proliferation of human CD34(+) hematopoietic progenitors transduced with FIP1L1-PDGFRα. We showed that the non-receptor protein tyrosine phosphatase SHP2 bound directly to tyrosine 720 of FIP1L1-PDGFRα. SHP2 knock-down decreased proliferation of Ba/F3 cells transformed with FIP1L1-PDGFRα and PDGFRα(D842V) and affected ERK signaling, but not STAT5 phosphorylation. Remarkably, SHP2 was not essential for cell proliferation and ERK phosphorylation induced by the wild-type PDGF receptor in response to ligand stimulation, suggesting a shift in the function of SHP2 downstream of oncogenic receptors. In conclusion, our results indicate that SHP2 is required for cell transformation and ERK activation by mutant PDGF receptors.
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Affiliation(s)
- Laura A Noël
- de Duve Institute, Université catholique de Louvain, MEXP - UCL B1.74.05, Avenue Hippocrate 75, BE-1200 Brussels, Belgium.
| | - Florence A Arts
- de Duve Institute, Université catholique de Louvain, MEXP - UCL B1.74.05, Avenue Hippocrate 75, BE-1200 Brussels, Belgium.
| | - Carmen P Montano-Almendras
- de Duve Institute, Université catholique de Louvain, MEXP - UCL B1.74.05, Avenue Hippocrate 75, BE-1200 Brussels, Belgium.
| | - Luk Cox
- Center for The Biology of Disease, VIB, Herestraat 49, BE-3000 Leuven, Belgium; Center for Human Genetics, KU Leuven, Leuven, Belgium.
| | - Olga Gielen
- Center for The Biology of Disease, VIB, Herestraat 49, BE-3000 Leuven, Belgium; Center for Human Genetics, KU Leuven, Leuven, Belgium.
| | - Federica Toffalini
- de Duve Institute, Université catholique de Louvain, MEXP - UCL B1.74.05, Avenue Hippocrate 75, BE-1200 Brussels, Belgium.
| | - Catherine Y Marbehant
- de Duve Institute, Université catholique de Louvain, MEXP - UCL B1.74.05, Avenue Hippocrate 75, BE-1200 Brussels, Belgium.
| | - Jan Cools
- Center for The Biology of Disease, VIB, Herestraat 49, BE-3000 Leuven, Belgium; Center for Human Genetics, KU Leuven, Leuven, Belgium.
| | - Jean-Baptiste Demoulin
- de Duve Institute, Université catholique de Louvain, MEXP - UCL B1.74.05, Avenue Hippocrate 75, BE-1200 Brussels, Belgium.
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92
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Nakayama A, Nakayama M, Turner CJ, Höing S, Lepore JJ, Adams RH. Ephrin-B2 controls PDGFRβ internalization and signaling. Genes Dev 2014; 27:2576-89. [PMID: 24298057 PMCID: PMC3861671 DOI: 10.1101/gad.224089.113] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Ephrin-B2 is essential for supporting mural cells; namely, pericytes and vascular smooth muscle cells (VSMCs). Nakayama et al. find that ephrin-B2 controls platelet-derived growth factor receptor β (PDGFRβ) distribution in the VSMC plasma membrane, endocytosis, and signaling. VSMCs lacking ephrin-B2 exhibited a redistribution of PDGFRβ from caveolin-positive to clathrin-associated membrane fractions and enhanced PDGF-B-induced PDGFRβ internalization. Mice lacking ephrin-B2 in vascular smooth muscle developed vessel wall defects and aortic aneurysms. These results suggest that ephrin-B2 is an important regulator of PDGFRβ endocytosis in mural cells. B-class ephrins, ligands for EphB receptor tyrosine kinases, are critical regulators of growth and patterning processes in many organs and species. In the endothelium of the developing vasculature, ephrin-B2 controls endothelial sprouting and proliferation, which has been linked to vascular endothelial growth factor (VEGF) receptor endocytosis and signaling. Ephrin-B2 also has essential roles in supporting mural cells (namely, pericytes and vascular smooth muscle cells [VSMCs]), but the underlying mechanism is not understood. Here, we show that ephrin-B2 controls platelet-derived growth factor receptor β (PDGFRβ) distribution in the VSMC plasma membrane, endocytosis, and signaling in a fashion that is highly distinct from its role in the endothelium. Absence of ephrin-B2 in cultured VSMCs led to the redistribution of PDGFRβ from caveolin-positive to clathrin-associated membrane fractions, enhanced PDGF-B-induced PDGFRβ internalization, and augmented downstream mitogen-activated protein (MAP) kinase and c-Jun N-terminal kinase (JNK) activation but impaired Tiam1–Rac1 signaling and proliferation. Accordingly, mutant mice lacking ephrin-B2 expression in vascular smooth muscle developed vessel wall defects and aortic aneurysms, which were associated with impaired Tiam1 expression and excessive activation of MAP kinase and JNK. Our results establish that ephrin-B2 is an important regulator of PDGFRβ endocytosis and thereby acts as a molecular switch controlling the downstream signaling activity of this receptor in mural cells.
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Affiliation(s)
- Akiko Nakayama
- Department of Tissue Morphogenesis, Max-Planck-Institute for Molecular Biomedicine, D-48149 Münster, Germany
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93
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Obermeier B, Daneman R, Ransohoff RM. Development, maintenance and disruption of the blood-brain barrier. Nat Med 2013; 19:1584-96. [PMID: 24309662 DOI: 10.1038/nm.3407] [Citation(s) in RCA: 1580] [Impact Index Per Article: 143.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 10/22/2013] [Indexed: 01/01/2023]
Abstract
The interface between the blood circulation and the neural tissue features unique characteristics that are encompassed by the term 'blood-brain barrier' (BBB). The main functions of this barrier, namely maintenance of brain homeostasis, regulation of influx and efflux transport, and protection from harm, are determined by its specialized multicellular structure. Every constituent cell type makes an indispensable contribution to the BBB's integrity. But if one member of the BBB fails, and as a result the barrier breaks down, there can be dramatic consequences and neuroinflammation and neurodegeneration can occur. In this Review, we highlight recently gained mechanistic insights into the development and maintenance of the BBB. We then discuss how BBB disruption can cause or contribute to neurological disease. Finally, we examine how this knowledge can be used to explore new possibilities for BBB repair.
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Affiliation(s)
- Birgit Obermeier
- Neuroinflammation Research Center, Department of Neuroscience, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
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94
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Wang Y, Pan L, Moens CB, Appel B. Notch3 establishes brain vascular integrity by regulating pericyte number. Development 2013; 141:307-17. [PMID: 24306108 DOI: 10.1242/dev.096107] [Citation(s) in RCA: 154] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Brain pericytes are important regulators of brain vascular integrity, permeability and blood flow. Deficiencies of brain pericytes are associated with neonatal intracranial hemorrhage in human fetuses, as well as stroke and neurodegeneration in adults. Despite the important functions of brain pericytes, the mechanisms underlying their development are not well understood and little is known about how pericyte density is regulated across the brain. The Notch signaling pathway has been implicated in pericyte development, but its exact roles remain ill defined. Here, we report an investigation of the Notch3 receptor using zebrafish as a model system. We show that zebrafish brain pericytes express notch3 and that notch3 mutant zebrafish have a deficit of brain pericytes and impaired blood-brain barrier function. Conditional loss- and gain-of-function experiments provide evidence that Notch3 signaling positively regulates brain pericyte proliferation. These findings establish a new role for Notch signaling in brain vascular development whereby Notch3 signaling promotes expansion of the brain pericyte population.
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Affiliation(s)
- Yuying Wang
- Departments of Pediatrics and Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, CO 80045, USA
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95
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Jo DH, Kim JH, Heo JI, Kim JH, Cho CH. Interaction between pericytes and endothelial cells leads to formation of tight junction in hyaloid vessels. Mol Cells 2013; 36:465-71. [PMID: 24213675 PMCID: PMC3887934 DOI: 10.1007/s10059-013-0228-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Revised: 09/03/2013] [Accepted: 09/09/2013] [Indexed: 11/25/2022] Open
Abstract
The hyaloid vessel is a transient vascular network that nourishes the lens and the primary vitreous in the early developmental periods. In hyaloid vessels devoid of the support of astrocytes, we demonstrate that tight junction proteins, zonula occludens-1 and occludin, are regularly expressed at the junction of endothelial cells. To figure out the factor influencing the formation of tight junctions in hyaloid vessels, we further progress to investigate the interactions between endothelial cells and pericytes, two representative constituent cells in hyaloid vessels. Interestingly, endothelial cells interact with pericytes in the early postnatal periods and the interaction between two cell types provokes the up-regulation of transforming growth factor β1. Further in vitro experiments demonstrate that transforming growth factor β1 induces the activation of Smad2 and Smad3 and the formation of tight junction proteins. Taken together, in hyaloid vessels, pericytes seem to regulate the formation of tight junctions by the interaction with endothelial cells even without the support of astrocytes. Additionally, we suggest that the hyaloid vessel is a valuable system that can be utilized for the investigation of cell-cell interaction in the formation of tight junctions in developing vasculatures.
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Affiliation(s)
- Dong Hyun Jo
- Fight against Angiogenesis-Related Blindness (FARB) Laboratory, Clinical Research Institute, Seoul National University Hospital, Seoul 110-744, Korea
- Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul 110-744, Korea
| | - Jin Hyoung Kim
- Fight against Angiogenesis-Related Blindness (FARB) Laboratory, Clinical Research Institute, Seoul National University Hospital, Seoul 110-744, Korea
| | - Jong-Ik Heo
- Ischemic/Hypoxic Disease Institute, College of Medicine, Seoul National University, Seoul 110-744, Korea
- Department of Pharmacology, College of Medicine, Seoul National University, Seoul 110-744, Korea
| | - Jeong Hun Kim
- Fight against Angiogenesis-Related Blindness (FARB) Laboratory, Clinical Research Institute, Seoul National University Hospital, Seoul 110-744, Korea
- Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul 110-744, Korea
- Ischemic/Hypoxic Disease Institute, College of Medicine, Seoul National University, Seoul 110-744, Korea
- Department of Ophthalmology, College of Medicine, Seoul National University, Seoul 110-744, Korea
| | - Chung-Hyun Cho
- Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul 110-744, Korea
- Ischemic/Hypoxic Disease Institute, College of Medicine, Seoul National University, Seoul 110-744, Korea
- Department of Pharmacology, College of Medicine, Seoul National University, Seoul 110-744, Korea
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96
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Mutations in the gene encoding PDGF-B cause brain calcifications in humans and mice. Nat Genet 2013; 45:1077-82. [PMID: 23913003 DOI: 10.1038/ng.2723] [Citation(s) in RCA: 241] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Accepted: 07/12/2013] [Indexed: 12/12/2022]
Abstract
Calcifications in the basal ganglia are a common incidental finding and are sometimes inherited as an autosomal dominant trait (idiopathic basal ganglia calcification (IBGC)). Recently, mutations in the PDGFRB gene coding for the platelet-derived growth factor receptor β (PDGF-Rβ) were linked to IBGC. Here we identify six families of different ancestry with nonsense and missense mutations in the gene encoding PDGF-B, the main ligand for PDGF-Rβ. We also show that mice carrying hypomorphic Pdgfb alleles develop brain calcifications that show age-related expansion. The occurrence of these calcium depositions depends on the loss of endothelial PDGF-B and correlates with the degree of pericyte and blood-brain barrier deficiency. Thus, our data present a clear link between Pdgfb mutations and brain calcifications in mice, as well as between PDGFB mutations and IBGC in humans.
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97
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Iwayama T, Olson LE. Involvement of PDGF in fibrosis and scleroderma: recent insights from animal models and potential therapeutic opportunities. Curr Rheumatol Rep 2013; 15:304. [PMID: 23307576 DOI: 10.1007/s11926-012-0304-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Fibrosis is the principal characteristic of the autoimmune disease known as scleroderma or systemic sclerosis (SSc). Studies published within the last three years suggest central involvement of platelet-derived growth factors (PDGFs) in SSc-associated fibrosis. PDGFs may also be involved in SSc-associated autoimmunity and vasculopathy. The PDGF signaling pathway is well understood and PDGF receptors are expressed on collagen-secreting fibroblasts and on mesenchymal stem and/or progenitor cells that may affect SSc in profound and unexpected ways. Although much work remains before we fully understand how PDGFs are involved in SSc, there is much interest in using PDGF inhibitors as a therapeutic approach to SSc.
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Affiliation(s)
- Tomoaki Iwayama
- Immunobiology and Cancer Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA.
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98
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Jadeja S, Mort RL, Keighren M, Hart AW, Joynson R, Wells S, Potter PK, Jackson IJ. A CNS-specific hypomorphic Pdgfr-beta mutant model of diabetic retinopathy. Invest Ophthalmol Vis Sci 2013; 54:3569-78. [PMID: 23633653 PMCID: PMC4025949 DOI: 10.1167/iovs.12-11125] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
PURPOSE A mouse mutant identified during a recessive N-ethyl-N-nitrosourea (ENU) mutagenesis screen exhibited ocular hemorrhaging resulting in a blood-filled orbit, and hence was named "redeye." We aimed to identify the causal mutation in redeye, and evaluate it as a model for diabetic retinopathy (DR). METHODS The causative gene mutation in redeye was identified by haplotype mapping followed by exome sequencing. Glucose tolerance tests, detailed histologic and immunofluorescence analyses, and vascular permeability assays were performed to determine the affect of redeye on glucose metabolism, pericyte recruitment, and the development of the retinal vasculature and blood-retinal barrier (BRB). RESULTS A mutation was identified in the Pdgfrb gene at position +2 of intron 6. We show that this change causes partial loss of normal splicing resulting in a frameshift and premature termination, and, therefore, a substantial reduction in normal Pdgfrb transcript. The animals exhibit defective pericyte recruitment restricted to the central nervous system (CNS) causing basement membrane and vascular patterning defects, impaired vascular permeability, and aberrant BRB development, resulting in vascular leakage and retinal ganglion cell apoptosis. Despite exhibiting classic features of diabetic retinopathy, redeye glucose tolerance is normal. CONCLUSIONS The Pdgfrb(redeye/redeye) mice exhibit all of the features of nonproliferative DR, including retinal neurodegeneration. In addition, the perinatal onset of the CNS-specific vascular phenotype negates the need to age animals or manage diabetic complications in other organs. Therefore, they are a more useful model for diseases involving pericyte deficiencies, such as DR, than those currently being used.
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Affiliation(s)
- Shalini Jadeja
- MRC Human Genetics Unit, MRC Institute of Genetics & Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Richard L. Mort
- MRC Human Genetics Unit, MRC Institute of Genetics & Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Margaret Keighren
- MRC Human Genetics Unit, MRC Institute of Genetics & Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Alan W. Hart
- MRC Human Genetics Unit, MRC Institute of Genetics & Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | | | | | | | - Ian J. Jackson
- MRC Human Genetics Unit, MRC Institute of Genetics & Molecular Medicine, University of Edinburgh, Edinburgh, UK
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99
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Sohet F, Daneman R. Genetic mouse models to study blood-brain barrier development and function. Fluids Barriers CNS 2013; 10:3. [PMID: 23305182 PMCID: PMC3675378 DOI: 10.1186/2045-8118-10-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2012] [Accepted: 11/20/2012] [Indexed: 12/21/2022] Open
Abstract
The blood–brain barrier (BBB) is a complex physiological structure formed by the blood vessels of the central nervous system (CNS) that tightly regulates the movement of substances between the blood and the neural tissue. Recently, the generation and analysis of different genetic mouse models has allowed for greater understanding of BBB development, how the barrier is regulated during health, and its response to disease. Here we discuss: 1) Genetic mouse models that have been used to study the BBB, 2) Available mouse genetic tools that can aid in the study of the BBB, and 3) Potential tools that if generated could greatly aid in our understanding of the BBB.
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Affiliation(s)
- Fabien Sohet
- UCSF Department of Anatomy, 513 Parnassus Ave HSW1301, San Francisco, 94117, California, USA.
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100
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Sagare AP, Bell RD, Zhao Z, Ma Q, Winkler EA, Ramanathan A, Zlokovic BV. Pericyte loss influences Alzheimer-like neurodegeneration in mice. Nat Commun 2013; 4:2932. [PMID: 24336108 PMCID: PMC3945879 DOI: 10.1038/ncomms3932] [Citation(s) in RCA: 483] [Impact Index Per Article: 43.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Accepted: 11/13/2013] [Indexed: 12/19/2022] Open
Abstract
Pericytes are cells in the blood-brain barrier that degenerate in Alzheimer's disease (AD), a neurological disorder associated with neurovascular dysfunction, abnormal elevation of amyloid β-peptide (Aβ), tau pathology and neuronal loss. Whether pericyte degeneration can influence AD-like neurodegeneration and contribute to disease pathogenesis remains, however, unknown. Here we show that in mice overexpressing Aβ-precursor protein, pericyte loss elevates brain Aβ40 and Aβ42 levels and accelerates amyloid angiopathy and cerebral β-amyloidosis by diminishing clearance of soluble Aβ40 and Aβ42 from brain interstitial fluid prior to Aβ deposition. We further show that pericyte deficiency leads to the development of tau pathology and an early neuronal loss that is normally absent in Aβ-precursor protein transgenic mice, resulting in cognitive decline. Our data suggest that pericytes control multiple steps of AD-like neurodegeneration pathogenic cascade in Aβ-precursor protein-overexpressing mice. Therefore, pericytes may represent a novel therapeutic target to modify disease progression in AD.
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Affiliation(s)
- Abhay P. Sagare
- Department of Physiology and Biophysics, Keck School of Medicine, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, California 90033, USA
- These authors contributed equally to this work
| | - Robert D. Bell
- Center of Neurodegenerative and Vascular Brain Disorders, University of Rochester Medical Center, Rochester, New York 14642, USA
- These authors contributed equally to this work
| | - Zhen Zhao
- Department of Physiology and Biophysics, Keck School of Medicine, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, California 90033, USA
- These authors contributed equally to this work
| | - Qingyi Ma
- Department of Physiology and Biophysics, Keck School of Medicine, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, California 90033, USA
| | - Ethan A. Winkler
- Center of Neurodegenerative and Vascular Brain Disorders, University of Rochester Medical Center, Rochester, New York 14642, USA
| | - Anita Ramanathan
- Department of Physiology and Biophysics, Keck School of Medicine, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, California 90033, USA
| | - Berislav V. Zlokovic
- Department of Physiology and Biophysics, Keck School of Medicine, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, California 90033, USA
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