Defective Wound-healing in Aging Gingival Tissue

Area of Science:

• Cellular Biology
• Aging Research
• Wound Healing Mechanisms

Background:

• Aging is associated with impaired wound healing, but the underlying cellular mechanisms in gingival tissues remain unclear.
• Understanding these mechanisms is crucial for developing interventions to improve healing in older populations.

Purpose of the Study:

• To investigate the cellular and molecular changes in gingival fibroblasts and wound healing associated with aging.
• To compare the function of young and aged human gingival fibroblasts in vitro.
• To evaluate the impact of aging on gingival wound repair in vivo.

Main Methods:

• Primary human gingival fibroblasts from young and aged donors were analyzed for proliferation, invasion, myofibroblastic differentiation, and collagen remodeling.
• Rat serum was used to stimulate fibroblast migration.
• Gingival wound healing was assessed in young and aged Sprague-Dawley rats.
• Statistical analysis included Mann-Whitney and Kruskal-Wallis tests.

Main Results:

• Aged fibroblasts exhibited significantly reduced proliferation, migration, Rac activation, and collagen remodeling compared to young fibroblasts.
• Serum from young rats enhanced cell migration more than serum from old rats.
• While both young and old fibroblasts increased alpha-smooth muscle actin (α-SMA) after TGF-β1 stimulation, only young fibroblasts effectively incorporated α-SMA into stress fibers.
• Old rats showed a significant delay in gingival wound healing after 7 days.

Conclusions:

• Cellular functions including migration, myofibroblastic differentiation, collagen remodeling, and proliferation are diminished in aged gingival fibroblasts.
• Impaired gingival wound healing in aging may result from intrinsic cellular defects and alterations in serum factors related to senescence.