title: Perlecan heparan sulfate deficiency impairs pulmonary vascular development and attenuates hypoxic pulmonary hypertension.
abstract: OBJECTIVE
  Excessive vascular cell proliferation is an important component of pulmonary hypertension (PH). Perlecan is the major heparan sulfate (HS) proteoglycan in the vascular extracellular matrix. It binds growth factors, including FGF2, and either restricts or promotes cell proliferation. In this study, we have explored the effects of perlecan HS deficiency on pulmonary vascular development and in hypoxia-induced PH.
  
  
  RESULTS
  In normoxia, Hspg2(Δ3/Δ3) mice, deficient in perlecan HS, had reduced pericytes and muscularization of intra-acinar vessels. Pulmonary angiography revealed a peripheral perfusion defect. Despite these abnormalities, right ventricular systolic pressure (RVSP) and myocardial mass remained normal. After 4 weeks of hypoxia, increases in the proportion of muscularized vessels, RVSP, and right ventricular hypertrophy were significantly less in Hspg2(Δ3/Δ3) compared with wild type. The early phase of hypoxia induced a significantly lower increase in fibroblast growth factor receptor-1 (FGFR1) protein level and receptor phosphorylation, and reduced pulmonary artery smooth muscle cell (PASMC) proliferation in Hspg2(Δ3/Δ3). At 4 weeks, FGF2 mRNA and protein were also significantly reduced in Hspg2(Δ3/Δ3) lungs. Ligand and carbohydrate engagement assay showed that perlecan HS is required for HS-FGF2-FGFR1 ternary complex formation. In vitro, proliferation assays showed that PASMC proliferation is reduced by selective FGFR1 inhibition. PASMC adhesion to fibronectin was higher in Hspg2(Δ3/Δ3) compared with wild type.
  
  
  CONCLUSIONS
  Perlecan HS chains are important for normal vascular arborization and recruitment of pericytes to pulmonary vessels. Perlecan HS deficiency also attenuates hypoxia-induced PH, where the underlying mechanisms involve impaired FGF2/FGFR1 interaction, inhibition of PASMC growth, and altered cell-matrix interactions.
authors.affiliation: Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden ya-ting.chang@ki.se.
authors.forename: Ya-Ting
authors.initials: YT
authors.lastname: Chang
authors.affiliation: Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Chi-Nan
authors.initials: CN
authors.lastname: Tseng
authors.affiliation: Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Philip
authors.initials: P
authors.lastname: Tannenberg
authors.affiliation: Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Linnéa
authors.initials: L
authors.lastname: Eriksson
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Stanford University, Stanford, CA, USA Stanford Cardiovascular Institute, Stanford University, Stanford, CA, USA.
authors.forename: Ke
authors.initials: K
authors.lastname: Yuan
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Stanford University, Stanford, CA, USA Stanford Cardiovascular Institute, Stanford University, Stanford, CA, USA.
authors.forename: Vinicio A
authors.initials: VA
authors.lastname: de Jesus Perez
authors.affiliation: Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Johan
authors.initials: J
authors.lastname: Lundberg
authors.affiliation: Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Mariette
authors.initials: M
authors.lastname: Lengquist
authors.affiliation: Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Ileana Ruxandra
authors.initials: IR
authors.lastname: Botusan
authors.affiliation: Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Sergiu-Bogdan
authors.initials: SB
authors.lastname: Catrina
authors.affiliation: Department of Cardiothoracic Surgery, Uppsala University, Uppsala, Sweden.
authors.forename: Phan-Kiet
authors.initials: PK
authors.lastname: Tran
authors.affiliation: Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Ulf
authors.initials: U
authors.lastname: Hedin
authors.affiliation: Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden Department of Experimental Medical Science, Lund University, Lund, Sweden.
authors.forename: Karin
authors.initials: K
authors.lastname: Tran-Lundmark
mesh_terms: D000818:Animals; D002448:Cell Adhesion; D049109:Cell Proliferation; D002478:Cells, Cultured; D005260:Female; D016222:Fibroblast Growth Factor 2 / Q000032:analysis; D019812:Heparan Sulfate Proteoglycans / Q000032:analysis / Q000172:deficiency / Q000378:metabolism*; D006976:Hypertension, Pulmonary / Q000209:etiology* / Q000517:prevention & control; D000860:Hypoxia / Q000150:complications*; D051379:Mice; D009131:Muscle, Smooth, Vascular / Q000166:cytology; D032389:Myocytes, Smooth Muscle / Q000502:physiology; D010766:Phosphorylation; D011651:Pulmonary Artery / Q000000981:diagnostic imaging / Q000502:physiology*; D011859:Radiography; D051496:Receptor, Fibroblast Growth Factor, Type 1 / Q000378:metabolism
chemical_list: D019812:Heparan Sulfate Proteoglycans; D016222:Fibroblast Growth Factor 2; C071927:perlecan; C496349:Fgfr1 protein, mouse; D051496:Receptor, Fibroblast Growth Factor, Type 1
keywords: FGF2; Heparan sulfate; Hypoxia; Perlecan; Pulmonary hypertension