Endothelial progenitor cells in the pathogenesis of idiopathic pulmonary fibrosis: an evolving concept.
BACKGROUND
Idiopathic pulmonary fibrosis (IPF) has been associated with abnormal vascular remodeling. Bone marrow derived endothelial progenitor cells (EPCs) are considered to possess lung tissue repair and vascular remodeling properties.


OBJECTIVE
The study aimed to assess early EPCs levels and EPCs endogenous vascular endothelial growth factor (VEGF) expression in IPF. In order to examine alterations in the mobilization of EPCs from the bone marrow we measured plasma VEGF.


RESULTS
Twenty-three patients with IPF and fifteen healthy subjects were included. The number of early EPCs colonies was markedly reduced in IPF patients vs controls (6.00±6.49 vs 49.68±16.73, respectively, p<0.001). EPCs were further decreased in patients presenting systolic pulmonary arterial pressure (sPAP)≥35 mmHg. The number of colonies per well correlated negatively with P((A-a))O(2) (r =  -0.750, p<0.001). Additionally, VEGF mRNA levels were significantly increased in IPF patients. There were no differences observed in VEGF plasma levels in IPF patients when compared to controls.


CONCLUSIONS
The current data suggest that inadequate levels of early EPCs may potentially contribute to suppressed repair and recovery of the damaged pulmonary endothelium and thereby may drive the sequence of events in profibrogenic direction. Increased VEGFmRNA levels in the clinical context of IPF may represent a compensatory mechanism to overcome reduced EPCs levels.
Respiratory Medicine Department, School of Medicine, University of Thessaly, Larissa, Greece.
Foteini
F
Malli
Angela
A
Koutsokera
Efrosini
E
Paraskeva
Epaminondas
E
Zakynthinos
Maria
M
Papagianni
Dimosthenes
D
Makris
Irene
I
Tsilioni
Paschalis Adam
PA
Molyvdas
Konstantinos I
KI
Gourgoulianis
Zoe
Z
Daniil
D000368:Aged; D001854:Bone Marrow Cells / Q000473:pathology; D018929:Cell Culture Techniques; D042783:Endothelial Cells / Q000473:pathology*; D005786:Gene Expression Regulation; D006801:Humans; D054990:Idiopathic Pulmonary Fibrosis / Q000209:etiology* / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology; D008297:Male; D009389:Neovascularization, Pathologic; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012995:Solubility; D013234:Stem Cells / Q000473:pathology*; D042461:Vascular Endothelial Growth Factor A / Q000097:blood / Q000737:chemistry / Q000235:genetics
D012333:RNA, Messenger; D042461:Vascular Endothelial Growth Factor A