Ageing alters zinc, magnesium, and interleukin-8 levels in human dermal fibroblasts

Abstract

Background: Ageing is linked to a decline in cellular functions, weakening the skin's defence mechanisms. At advanced ages, deficiencies in micronutrients like zinc and magnesium are common. Zinc deficiency from inadequate intake or absorption can lead to skin issues such as delayed wound healing and eczema. Dysregulated zinc homeostasis can increase the risk of dermatitis and psoriasis.

Objectives: This study examined the relationship between zinc and magnesium levels and skin ageing and inflammation in human dermal fibroblasts from young and old donors.

Methods: Primary dermal fibroblasts from young (20-30 years) and older (62-75 years) donors were assessed. We evaluated oxidative stress, determined susceptibility to senescence, and analysed gene expression profiles while quantifying the secretion of the chemokine interleukin-8. Markers of zinc homeostasis were evaluated by assessing protein expression via western blotting, and both free zinc ions and total metal ion concentrations were quantified.

Results: Older fibroblasts showed increased oxidative stress and higher susceptibility to senescence. Interleukin-6 expression rose in aged cells, while interleukin-8 secretion declined significantly. Free zinc ion concentrations and zinc transporter 1 expression were elevated, along with total zinc and magnesium concentrations.

Conclusions: Reduced interleukin-8 secretion compromises immune regulation in ageing skin. Elevated free zinc ion levels and zinc transporter expression contribute to eventual cellular zinc loss, impairing inflammatory responses and weakening immunity. These findings highlight the critical role of zinc and magnesium micronutrient balance in maintaining skin health during ageing.

Keywords: Ageing; Cytokines; Dermal Fibroblasts; Immunity; Inflammation; Magnesium; Zinc.