Regulation of Epidermal Ferritin Expression Influences Systemic Iron Homeostasis

Area of Science:

• Dermatology
• Iron Metabolism
• Molecular Biology

Background:

• Hepcidin, a liver hormone, regulates dietary iron absorption, influenced by iron levels and inflammation.
• Emerging evidence suggests the skin, specifically keratinocytes, plays a role in iron homeostasis.
• This includes epidermal iron uptake via transferrin receptors and local hepcidin production.

Purpose of the Study:

• To investigate keratinocyte responses to varying iron conditions.
• To explore the impact of iron on epidermal differentiation and associated gene expression.
• To elucidate the skin's role in systemic iron regulation and inflammation.

Main Methods:

• In vitro and in vivo characterization of keratinocyte iron storage.
• Analysis of epidermal differentiation and gene expression under different iron conditions.
• Studies in mice to correlate systemic iron with epidermal iron content.
• Investigation of iron metabolism during topical versus systemic inflammation.

Main Results:

• Keratinocytes demonstrate significant iron storage capacity both in vitro and in vivo.
• Iron influences epidermal differentiation and gene expression related to inflammation and barrier function.
• Systemic iron levels in mice directly correlate with epidermal iron content.
• Topical inflammation induces a localized iron-deficiency phenotype with reduced liver hepcidin.

Conclusions:

• Keratinocytes and epidermal iron storage are significant regulators of iron homeostasis.
• The cutaneous inflammatory state directly influences iron regulation.
• These findings highlight a novel role for the skin in maintaining systemic iron balance.