DMT1 gene expression and cadmium absorption in human absorptive enterocytes

Area of Science:

• Cell Biology
• Molecular Biology
• Toxicology

Background:

• Divalent Metal Transporter 1 (DMT1) is a key transporter for iron and other divalent metals.
• DMT1 is upregulated in iron deficiency and hereditary hemochromatosis, suggesting a role in dietary iron absorption.
• Previous studies indicate DMT1 can transport toxic metals like cadmium.

Purpose of the Study:

• To investigate the correlation between cadmium absorption and DMT1 gene expression in human absorptive enterocytes.
• To determine the effect of iron supplementation on cadmium uptake and transport.
• To elucidate the role of DMT1 in mediating cadmium absorption.

Main Methods:

• Utilized differentiated Caco-2 cell monolayers as a model for human absorptive enterocytes.
• Treated cells with iron-supplemented or control medium for 1, 3, or 7 days.
• Measured cadmium transport across cell monolayers and DMT1 gene expression at each time point.

Main Results:

• Iron treatment for 3 and 7 days significantly reduced cadmium uptake by approximately 50%.
• Cadmium transport across the basolateral membrane was reduced by 75% after 3 and 7 days of iron treatment.
• DMT1 gene expression was reduced by about 50% in iron-treated cells at 3 and 7 days, correlating with reduced cadmium uptake.

Conclusions:

• Cadmium uptake in human absorptive enterocytes is likely mediated by DMT1.
• Iron supplementation downregulates DMT1 expression, thereby reducing cadmium absorption.
• These findings highlight DMT1's role in the absorption of both essential and toxic divalent metals.