title: Characterization and functions of vascular adventitial fibroblast subpopulations.
abstract: BACKGROUND
  Adventitial fibroblasts have been shown to play an important role in vascular remodeling and contribute to neointimal formation in vascular diseases. However, little is known about adventitial fibroblast subpopulations. This study explored the process of isolating rat thoracic aorta adventitial fibroblast subpopulations and characterized their properties following stimulation with angiotensin II (ANG II), a critical factor involved in cardiovascular diseases such as hypertension.
  
  
  METHODS
  Adventitial fibroblasts were isolated and cultured from rat aorta. Fibroblast subpopulations were individually expanded using cloning ring techniques. Cells were treated with ANG II (10 nM, 100 nM and 1 μM) for 0.5, 1, 1.5, 3, 6, 12, or 24 h, and ANG II-induced proliferation and migration were measured by MTT assay and Transwell. Cells were treated with ANG II (100 nM) in the presence or absence of ANG II receptor antagonists (100 μM), losartan (for AT1) and PD-123319 (for AT2). PreproET-1 mRNA and ET-1 were determined by RT-PCR and ELISA, respectively. Collagen type I was detected by western blotting.
  
  
  RESULTS
  Two major fibroblast subpopulations were found in the adventitia, epithelioid-like cells and spindle-like cells; Although ANG II promotes the growth of both subpopulations, epithelioid-like cell proliferation shows dose-dependency on ANG II from 10 nM to 1 μM, while proliferation of spindle-like cells reaches a peak value following 100 nM ANG II stimulation; ANG II stimulation enhanced epithelioid-like but not spindle-like cell migration; ANG II dose-dependently increased the expression of preproET-1 and collagen type I, and enhanced ET-1 secretion in epithelioid-like but not spindle-like cells, effects abolished by the AT1 receptor antagonist, but not with AT2 receptor antagonist.
  
  
  CONCLUSIONS
  Adventitial fibroblasts are heterogeneous and epithelioid-like subpopulations with high sensitivity to ANG II stimulation may be implicated in the pathophysiological mechanisms of vascular remodeling, reparative processes and cardiovascular diseases.
authors.affiliation: Center of Bioreactor and Protein Drug Research and Development of Hebei Universities, Hebei Chemical and Pharmaceutical College, Shijiazhuang, Hebei, China.
authors.forename: Sheng Jun
authors.initials: SJ
authors.lastname: An
authors.forename: Pei
authors.initials: P
authors.lastname: Liu
authors.forename: Tie Mei
authors.initials: TM
authors.lastname: Shao
authors.forename: Zhi Jun
authors.initials: ZJ
authors.lastname: Wang
authors.forename: Hai Gang
authors.initials: HG
authors.lastname: Lu
authors.forename: Zhan
authors.initials: Z
authors.lastname: Jiao
authors.forename: Xue
authors.initials: X
authors.lastname: Li
authors.forename: Jun Qiu
authors.initials: JQ
authors.lastname: Fu
mesh_terms: D063194:Adventitia / Q000166:cytology / Q000187:drug effects*; D000804:Angiotensin II / Q000008:administration & dosage; D057912:Angiotensin II Type 2 Receptor Blockers / Q000008:administration & dosage; D000818:Animals; D001013:Aorta, Thoracic / Q000166:cytology / Q000187:drug effects*; D019070:Cell Lineage / Q000187:drug effects / Q000235:genetics*; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D024042:Collagen Type I / Q000096:biosynthesis; D019332:Endothelin-1 / Q000096:biosynthesis; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects*; D007093:Imidazoles / Q000008:administration & dosage; D019808:Losartan / Q000008:administration & dosage; D008297:Male; D011725:Pyridines / Q000008:administration & dosage; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats
chemical_list: D057912:Angiotensin II Type 2 Receptor Blockers; D024042:Collagen Type I; D019332:Endothelin-1; D007093:Imidazoles; D011725:Pyridines; D012333:RNA, Messenger; D000804:Angiotensin II; C073402:PD 123319; D019808:Losartan