The effects of extracellular matrix degradation mediated by chronic inflammation in aged skin on the structure and function of eccrine sweat glands.

Aged eccrine sweat glands exhibit structural loosening compared to young tissues in both mice and humans.

• Comparative analysis was performed between skin tissues from young and aged mice and human subjects.
• Structural loosening of aged ESG was observed through histological examination.
• The study used both animal models and human skin tissue samples for comparative analysis.

Type I and type II collagen expression is significantly reduced in aged eccrine sweat gland tissues.

• A significant reduction in the expression of extracellular matrix (ECM) components—type I and type II collagen—was observed in aged skin.
• Type I and type II collagen were found to be distributed around ESGs, providing structural and functional support.
• Collagen reduction was observed in both aged mouse and human skin samples.

The inflammatory cytokine IL-1β and matrix metalloproteinase MMP-1 are significantly upregulated in aged skin tissues.

• A significant upregulation of IL-1β and MMP-1 was observed in aged tissues compared to young tissues.
• IL-1β and MMP-1 upregulation was found to modulate collagen degradation in aged skin.
• These findings suggest that ECM degradation may be regulated by an inflammatory microenvironment in aging.

Intradermal injection of IL-1β into mouse footpads established a chronic inflammation model that suppressed ESG function and reduced collagen surrounding ESGs.

• IL-1β was injected intradermally into the footpads of mice to create a chronic inflammation model.
• The model demonstrated suppressed ESG function following IL-1β injection.
• Structural loosening of ESG tissues was observed in the IL-1β-injected mice.
• A marked reduction of type I and type II collagen surrounding the ESGs was observed in this chronic inflammation model.

The IL-1β-MMP-1 inflammatory pathway activation in aging contributes to ESG dysfunction and structural disruption through collagen degradation.

• The study proposes that the IL-1β-MMP-1 axis mediates collagen degradation around eccrine sweat glands.
• ECM degradation driven by chronic inflammation was identified as an underlying mechanism for age-related impairment of ESG function.
• Both structural loosening and functional suppression of ESGs were linked to IL-1β-mediated MMP-1 upregulation and subsequent collagen loss.