title: Granulocyte colony-stimulating factor improves cerebrovascular reserve capacity by enhancing collateral growth in the circle of Willis.
abstract: OBJECTIVE
  Restoration of cerebrovascular reserve capacity (CVRC) depends on the recruitment and positive outward remodeling of preexistent collaterals (arteriogenesis). With this study, we provide functional evidence that granulocyte colony-stimulating factor (G-CSF) augments therapeutic arteriogenesis in two animal models of cerebral hypoperfusion. We identified an effective dosing regimen that improved CVRC and stimulated collateral growth, thereby improving the outcome after experimentally induced stroke.
  
  
  METHODS
  We used two established animal models of (a) cerebral hypoperfusion (mouse, common carotid artery ligation) and (b) cerebral arteriogenesis (rat, 3-vessel occlusion). Following therapeutic dose determination, both models received either G-CSF, 40 μg/kg every other day, or vehicle for 1 week. Collateral vessel diameters were measured following latex angiography. Cerebrovascular reserve capacities were assessed after acetazolamide stimulation. Mice with left common carotid artery occlusion (CCAO) were additionally subjected to middle cerebral artery occlusion, and stroke volumes were assessed after triphenyltetrazolium chloride staining. Given the vital role of monocytes in arteriogenesis, we assessed (a) the influence of G-CSF on monocyte migration in vitro and (b) monocyte counts in the adventitial tissues of the growing collaterals in vivo.
  
  
  RESULTS
  CVRC was impaired in both animal models 1 week after induction of hypoperfusion. While G-CSF, 40 μg/kg every other day, significantly augmented cerebral arteriogenesis in the rat model, 50 or 150 μg/kg every day did not show any noticeable therapeutic impact. G-CSF restored CVRC in mice (5 ± 2 to 12 ± 6%) and rats (3 ± 4 to 19 ± 12%). Vessel diameters changed accordingly: in rats, the diameters of posterior cerebral arteries (ipsilateral: 209 ± 7-271 ± 57 μm; contralateral: 208 ± 11-252 ± 28 μm) and in mice the diameter of anterior cerebral arteries (185 ± 15-222 ± 12 μm) significantly increased in the G-CSF groups compared to controls. Stroke volume in mice (10 ± 2%) was diminished following CCAO (7 ± 4%) and G-CSF treatment (4 ± 2%). G-CSF significantly increased monocyte migration in vitro and perivascular monocyte numbers in vivo.
  
  
  CONCLUSIONS
  G-CSF augments cerebral collateral artery growth, increases CVRC and protects from experimentally induced ischemic stroke. When comparing three different dosing regimens, a relatively low dosage of G-CSF was most effective, indicating that the common side effects of this cytokine might be significantly reduced or possibly even avoided in this indication.
authors.affiliation: Department of Internal Medicine, Cardiology and Angiology, Richard Thoma Laboratories for Arteriogenesis, Center for Cardiovascular Research and Experimental and Clinical Research Center, [corrected] Charité-Universitätsmedizin Berlin, Berlin, Germany. andre.duelsner@charite.de
authors.forename: André
authors.initials: A
authors.lastname: Duelsner
authors.forename: Nora
authors.initials: N
authors.lastname: Gatzke
authors.forename: Johanna
authors.initials: J
authors.lastname: Glaser
authors.forename: Philipp
authors.initials: P
authors.lastname: Hillmeister
authors.forename: Meijing
authors.initials: M
authors.lastname: Li
authors.forename: Eun-Ji
authors.initials: EJ
authors.lastname: Lee
authors.forename: Kerstin
authors.initials: K
authors.lastname: Lehmann
authors.forename: Daniel
authors.initials: D
authors.lastname: Urban
authors.forename: Heike
authors.initials: H
authors.lastname: Meyborg
authors.forename: Philipp
authors.initials: P
authors.lastname: Stawowy
authors.forename: Andreas
authors.initials: A
authors.lastname: Busjahn
authors.forename: Stephanie
authors.initials: S
authors.lastname: Nagorka
authors.forename: Anja Bondke
authors.initials: AB
authors.lastname: Persson
authors.forename: Rico
authors.initials: R
authors.lastname: Laage
authors.forename: Armin
authors.initials: A
authors.lastname: Schneider
authors.forename: Ivo R
authors.initials: IR
authors.lastname: Buschmann
mesh_terms: D000818:Animals; D001157:Arterial Occlusive Diseases / Q000473:pathology; D016893:Carotid Stenosis / Q000473:pathology; D002465:Cell Movement / Q000187:drug effects; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D002561:Cerebrovascular Disorders / Q000188:drug therapy* / Q000473:pathology; D002941:Circle of Willis / Q000187:drug effects / Q000254:growth & development*; D003097:Collateral Circulation / Q000187:drug effects*; D003627:Data Interpretation, Statistical; D016179:Granulocyte Colony-Stimulating Factor / Q000627:therapeutic use*; D006439:Hemodynamics / Q000187:drug effects; D020244:Infarction, Middle Cerebral Artery / Q000473:pathology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009000:Monocytes / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000627:therapeutic use; D020127:Recovery of Function
chemical_list: D011994:Recombinant Proteins; D016179:Granulocyte Colony-Stimulating Factor