PCBs enhance collagen I expression from human peritoneal fibroblasts

Area of Science:

• Environmental toxicology
• Cell biology
• Fibrosis research

Background:

• Polychlorinated biphenyls (PCBs) are persistent environmental pollutants.
• PCBs are known to have various toxic effects.
• The role of PCBs in fibrotic disease pathogenesis is not well understood.

Purpose of the Study:

• To investigate the effect of four specific PCB congeners (PCB-77, PCB-105, PCB-153, and PCB-180) on the expression of adhesion markers in human fibroblasts.
• To determine if PCBs influence the expression of transforming growth factor beta1 (TGF-beta1), vascular endothelial growth factor (VEGF), and type I collagen.

Main Methods:

• Primary cultures of normal human peritoneal and adhesion fibroblasts were established.
• Fibroblasts were exposed to four PCB congeners (PCB-77, PCB-105, PCB-153, PCB-180) at 20 ppm for 24 hours.
• Real-time reverse transcriptase polymerase chain reaction (RT-PCR) was used to quantify mRNA levels of type I collagen, VEGF, and TGF-beta1.

Main Results:

• PCB exposure did not affect the mRNA levels of beta-actin or cell viability.
• Transforming growth factor beta1 (TGF-beta1) and vascular endothelial growth factor (VEGF) mRNA levels remained unchanged after PCB treatment.
• Type I collagen mRNA levels were significantly increased in both peritoneal and adhesion fibroblasts following exposure to all four PCB congeners.

Conclusions:

• The study demonstrates that specific PCB congeners can markedly increase type I collagen expression in human fibroblasts.
• This finding is the first to indicate the involvement of organochlorines in the pathogenesis of tissue fibrosis.
• PCB exposure may be an etiologic factor in human ailments characterized by fibrosis.