Hypoxic pulmonary artery fibroblasts trigger proliferation of vascular smooth muscle cells: role of hypoxia-inducible transcription factors.
Chronic lung hypoxia causes vascular remodeling with pulmonary artery smooth muscle cell (SMCPA) hyperplasia, resulting in pulmonary hypertension and cor pulmonale. We investigated SMCPA and pulmonary artery adventitial fibroblasts (FBPA) for their proliferative response to hypoxia. Strong SMCPA growth occurred under hypoxic conditions in SMCPA/FBPA co-cultures, but not in SMCPA monocultures. SMCPA growth was fully reproduced by transferring serum-free supernatant from hypoxic cultured FBPA to normoxic SMCPA. Hypoxia-inducible-transcription-factor subtypes (HIF-1alpha, HIF-2alpha, HIF-3alpha) and its dependent target genes, carrying the hypoxia-responsive-element as regulatory component, were strongly activated in both hypoxic FBPA and SMCPA. HIF-transcription-factor decoy technique, employed to FBPA during hypoxic culturing, blocked the mitogenic activity of FBPA conditioned medium on SMCPA. The data suggest that hypoxia-driven gene regulation in pulmonary artery fibroblasts results in a mitogenic stimulus on adjacent pulmonary artery smooth muscle cells, and HIF-transcription-decoy may offer a new therapeutic approach to suppress these events.
Department of Internal Medicine/Pulmonary and Critical Care Medicine, Justus-Liebig-University, D-35385 Giessen, Germany.
Frank
F
Rose
Friedrich
F
Grimminger
Jutta
J
Appel
Mathias
M
Heller
Volker
V
Pies
Norbert
N
Weissmann
Ludger
L
Fink
Sebastian
S
Schmidt
Stefanie
S
Krick
Gieri
G
Camenisch
Max
M
Gassmann
Werner
W
Seeger
Jörg
J
Hänze
D051792:Basic Helix-Loop-Helix Proteins; D002455:Cell Division; D015687:Cell Hypoxia / Q000502:physiology; D002478:Cells, Cultured; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism*; D015870:Gene Expression; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000378:metabolism*; D011651:Pulmonary Artery / Q000166:cytology / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015534:Trans-Activators / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics*; D000099162:Endothelial PAS Domain-Containing Protein 1
D051792:Basic Helix-Loop-Helix Proteins; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D012333:RNA, Messenger; D015534:Trans-Activators; D014157:Transcription Factors; D000099162:Endothelial PAS Domain-Containing Protein 1; C497442:HIF1A protein, human; C424683:Hif3a protein, rat