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Differential effects of oxygen on human dermal fibroblasts: acute versus chronic hypoxia
Author(s) -
Siddiqui Aamir,
Galiano Robert D.,
Connors David,
Gruskin Elliott,
Wu Liancun,
Mustoe Thomas A.
Publication year - 1996
Publication title -
wound repair and regeneration
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.847
H-Index - 109
eISSN - 1524-475X
pISSN - 1067-1927
DOI - 10.1046/j.1524-475x.1996.40207.x
Subject(s) - hypoxia (environmental) , oxygen , differential effects , medicine , chemistry , organic chemistry
The observation that many chronic wounds are ischemic has spurred a series of studies evaluating the response of cells exposed to hypoxia. To date, these studies have shown largely beneficial effects from hypoxia, such as increased cellular replication and procollagen synthesis. These findings are counter‐intuitive from a clinical standpoint because cellular growth and synthetic function are known to be retarded in chronic ischemic wounds. We have established an in vitro system in which human dermal fibroblasts grown chronically at 5 ± 3 mm Hg will proliferate at a rate three times slower than those fibroblasts grown under standard culture conditions (namely an oxygen partial pressure of 150 mm Hg). No phenotypic changes are noted in chronically hypoxic cells, and the growth‐retarding effects are reversible when the cells are returned to standard oxygen conditions. Competitive reverse transcription‐polymerase chain reaction showed that acute exposure to hypoxia (up to 1 week) results in a 6.3‐fold increase in the relative expression of transforming growth factor‐β1 messenger RNA, whereas chronic exposure to hypoxia leads to a 3.1‐fold decrease in this message. Collagen production measured at both the mRNA and protein level is also decreased in the setting of chronic hypoxia. We propose that this system may be the most appropriate setting for studying the role of oxygen on dermal fibroblasts in ischemic, nonhealing wounds.