Hypoxia-induced irreversible up-regulation of type I collagen and transforming growth factor-beta1 in human peritoneal fibroblasts.
OBJECTIVE
To determine whether restoration of normoxia after a hypoxic insult returns the molecular expression of type I collagen and TGF-beta1 to baseline levels.


METHODS
Prospective experimental study.


METHODS
University medical center.


METHODS
Primary cultures of fibroblasts established from peritoneal tissues of five patients.


METHODS
Hypoxia treatment of the primary cultured fibroblasts.


METHODS
Cultured human peritoneal fibroblasts (HPF) were maintained under hypoxic conditions (2% oxygen) for 24 hours and then transferred into normal culture conditions (normoxia) for another 24 hours. Total cellular RNA from cells was collected and subjected to multiplex reverse transcription polymerase chain reaction to quantitate type I collagen and transforming growth factor (TGF)-beta1 mRNA levels in response to these treatments.


RESULTS
Hypoxia treatment resulted in 30% and 50% increases in type I collagen and TGF-beta1 expression, respectively. Restoration of normoxia after hypoxia treatment failed to restore type I collagen and TGF-beta1 expression to their baseline levels.


CONCLUSIONS
These data support the hypothesis that hypoxia induces irreversible molecular changes in peritoneal fibroblasts that produce a phenotype that increases extracellular matrix expression and thereby would promote adhesion development. Thus once a phenotype consistent with increased adhesion development is manifested, restoration of oxygen supply does not reverse the stimulation of HPF type I collagen and TGF-beta1 expression. This observation may in part explain the clinical observation that adhesion reformation is more difficult to prevent than de novo adhesion formation.
Saed
Ghassan M
GM
Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, and the C. S. Mott Center for Human Growth and Development, Wayne State University, Detroit, Michigan 48201 , USA. g.saed@wayne.edu
Diamond
Michael P
MP
D002478:Cells, Cultured; D024042:Collagen Type I / Q000235:genetics / Q000378:metabolism*; D005347:Fibroblasts / Q000378:metabolism*; D006801:Humans; D000860:Hypoxia / Q000378:metabolism* / Q000473:pathology; D010537:Peritoneum / Q000378:metabolism* / Q000473:pathology; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism*; D053773:Transforming Growth Factor beta1; D015854:Up-Regulation
D024042:Collagen Type I; D012333:RNA, Messenger; C508960:TGFB1 protein, human; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1