Superoxide induces the adhesion phenotype role of hypoxia in the pathogenesis of the adhesion development

Abstract

ObjectiveExposure of normal peritoneal fibroblasts to hypoxia has been shown to induce irreversible molecular changes in peritoneal fibroblasts that produce a phenotype, which increases type I collagen and transforming growth factor beta 1 (TGF-b1) expression and thereby would promote adhesion development. This effect is hypothesized to be mediated by superoxide ions generated upon exposure to hypoxia. To determine the effect of xanthene oxidase (XO), a superoxide generating system, and superoxide dismutase (SOD), a superoxide scavenger, on the expression of the adhesion phenotype markers; TGF-b1 and type I collagen.DesignCell Culture Study.Materials and methodsFibroblasts from normal peritoneal and adhesion tissues were cultured with and without SOD (10 U/ml) or XO (14.4 U/ml), which generates superoxide at a rate of 1.4 μM per minute, for 24 hours. Real time RT/PCR was utilized to measure mRNA levels for TGF-b1 and type I collagen.ResultsAs expected, adhesion fibroblasts exhibited significantly higher basal mRNA levels for both TGF-b1 and type I collagen as compared to normal peritoneal fibroblasts. Treatment with XO resulted in a significant increase in both TGF-b1 and type I collagen in normal peritoneal and adhesion fibroblasts. In contrast, treatment with SOD resulted in a significant decrease in both TGF-b1 and type I collagen in normal peritoneal and adhesion fibroblasts.ConclusionsOur results clearly indicate that superoxide is a key player in the formation of the adhesion phenotype. Furthermore, reduction in superoxide levels was shown to significantly reduce the adhesion phenotype markers suggesting a possible mechanism for intervention in the development of the adhesion phenotype. ObjectiveExposure of normal peritoneal fibroblasts to hypoxia has been shown to induce irreversible molecular changes in peritoneal fibroblasts that produce a phenotype, which increases type I collagen and transforming growth factor beta 1 (TGF-b1) expression and thereby would promote adhesion development. This effect is hypothesized to be mediated by superoxide ions generated upon exposure to hypoxia. To determine the effect of xanthene oxidase (XO), a superoxide generating system, and superoxide dismutase (SOD), a superoxide scavenger, on the expression of the adhesion phenotype markers; TGF-b1 and type I collagen. Exposure of normal peritoneal fibroblasts to hypoxia has been shown to induce irreversible molecular changes in peritoneal fibroblasts that produce a phenotype, which increases type I collagen and transforming growth factor beta 1 (TGF-b1) expression and thereby would promote adhesion development. This effect is hypothesized to be mediated by superoxide ions generated upon exposure to hypoxia. To determine the effect of xanthene oxidase (XO), a superoxide generating system, and superoxide dismutase (SOD), a superoxide scavenger, on the expression of the adhesion phenotype markers; TGF-b1 and type I collagen. DesignCell Culture Study. Cell Culture Study. Materials and methodsFibroblasts from normal peritoneal and adhesion tissues were cultured with and without SOD (10 U/ml) or XO (14.4 U/ml), which generates superoxide at a rate of 1.4 μM per minute, for 24 hours. Real time RT/PCR was utilized to measure mRNA levels for TGF-b1 and type I collagen. Fibroblasts from normal peritoneal and adhesion tissues were cultured with and without SOD (10 U/ml) or XO (14.4 U/ml), which generates superoxide at a rate of 1.4 μM per minute, for 24 hours. Real time RT/PCR was utilized to measure mRNA levels for TGF-b1 and type I collagen. ResultsAs expected, adhesion fibroblasts exhibited significantly higher basal mRNA levels for both TGF-b1 and type I collagen as compared to normal peritoneal fibroblasts. Treatment with XO resulted in a significant increase in both TGF-b1 and type I collagen in normal peritoneal and adhesion fibroblasts. In contrast, treatment with SOD resulted in a significant decrease in both TGF-b1 and type I collagen in normal peritoneal and adhesion fibroblasts. As expected, adhesion fibroblasts exhibited significantly higher basal mRNA levels for both TGF-b1 and type I collagen as compared to normal peritoneal fibroblasts. Treatment with XO resulted in a significant increase in both TGF-b1 and type I collagen in normal peritoneal and adhesion fibroblasts. In contrast, treatment with SOD resulted in a significant decrease in both TGF-b1 and type I collagen in normal peritoneal and adhesion fibroblasts. ConclusionsOur results clearly indicate that superoxide is a key player in the formation of the adhesion phenotype. Furthermore, reduction in superoxide levels was shown to significantly reduce the adhesion phenotype markers suggesting a possible mechanism for intervention in the development of the adhesion phenotype. Our results clearly indicate that superoxide is a key player in the formation of the adhesion phenotype. Furthermore, reduction in superoxide levels was shown to significantly reduce the adhesion phenotype markers suggesting a possible mechanism for intervention in the development of the adhesion phenotype.