Type XVII collagen coordinates proliferation in the interfollicular epidermis

Area of Science:

• Dermatology
• Molecular Biology
• Aging Research

Background:

• Type XVII collagen (COL17) is a transmembrane protein at the epidermal basement membrane.
• COL17 deficiency is linked to premature hair aging and junctional epidermolysis bullosa.

Purpose of the Study:

• To investigate the role of COL17 in regulating interfollicular epidermis (IFE) proliferation in neonatal and aged skin.
• To explore the mechanisms underlying COL17's function in skin homeostasis and aging.

Main Methods:

• Utilized neonatal and aged mouse models with COL17 deficiency or overexpression.
• Analyzed epidermal proliferation, Wnt signaling pathways, and protein kinase C activity.

Main Results:

• Loss of COL17 in neonatal mice caused transient IFE hypertrophy via aberrant Wnt signaling, which was reversible upon COL17 replenishment.
• Physical aging led to loss of membranous COL17 in basal cells, associated with inactive protein kinase C signaling and epidermal hyperproliferation.
• Overexpression of COL17 in aged mouse epidermis suppressed IFE hypertrophy.

Conclusions:

• COL17 plays a critical role in governing IFE proliferation in both neonatal and aged skin, through distinct mechanisms.
• COL17 function is crucial for maintaining skin homeostasis and preventing age-related epidermal changes.
• COL17 represents a potential therapeutic target for anti-aging strategies in the skin.