PCB-77 disturbs iron homeostasis through regulating hepcidin gene expression

Gene. 2013 Dec 10;532(1):146-51. doi: 10.1016/j.gene.2013.09.023. Epub 2013 Sep 19.

Abstract

PCBs are a family of persistent environmental toxicants with a wide spectrum of toxic features, such as immunotoxicity, hepatoxicity, endocrine disruption effects, and oncogenic effects. To date, little has been done to investigate the potential influence of PCB exposure on iron metabolism. Deregulated iron would lead to either iron deficiency or iron excess, coupled with various diseases such as anemia or hemochromatosis. Iron metabolism is strictly governed by the hepcidin-ferroportin axis, and hepcidin is the key regulator that is secreted by hepatocytes. Here, we found that PCB-77 could go through plasma membrane and accumulate in hepatocytes. PCB-77 was demonstrated to suppress hepcidin expression in HepG2 and L-02 hepatocytes. Moreover, hepatic hepcidin was observed to be inhibited in mice upon administration of PCB-77. Due to reduced hepcidin concentration, serum iron content was increased, with a significant reduction of splenic iron content. Together, we deciphered the molecular mechanism responsible for PCB-conducted disturbance on iron homeostasis, i.e. through misregulating hepatic hepcidin expression.

Keywords: 3,3′,4,4′-tetrachlorobiphenyl; 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; BMP; DMSO; ERE; GC–MS; Hepatocytes; Hepcidin; IL-6; Iron homeostasis; LDH; MTT; PCB-77; PCBs; bone morphogenetic protein; dimethylsulfoxide; estrogen response elements; gas chromatography–mass spectrometry; interleukin- 6; lactate dehydrogenase; polychlorinated biphenyls; qRT-PCR; quantitative real-time polymerase chain reaction.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Female
  • Gene Expression Regulation / drug effects
  • Hep G2 Cells / drug effects
  • Hepatocytes / drug effects
  • Hepcidins / genetics*
  • Homeostasis / drug effects*
  • Homeostasis / genetics
  • Humans
  • Iron / blood
  • Iron / metabolism*
  • Liver / drug effects
  • Liver / metabolism
  • Mice
  • Mice, Inbred BALB C
  • Polychlorinated Biphenyls / toxicity*
  • Spleen / drug effects
  • Spleen / metabolism

Substances

  • Hepcidins
  • Polychlorinated Biphenyls
  • Iron
  • 3,4,3',4'-tetrachlorobiphenyl