Human Skin Keratinocytes on Sustained TGF-β Stimulation Reveal Partial EMT Features and Weaken Growth Arrest...

Area of Science:

• Cell Biology
• Wound Healing Research
• Molecular Mechanisms

Background:

• Defects in keratinocyte re-epithelialization impair wound closure.
• Unbalanced cytokine signaling, including Transforming Growth Factor-β (TGF-β), is implicated in wound healing impairment.
• Molecular events underlying chronic wound development are poorly understood due to limited human studies.

Purpose of the Study:

• To investigate the impact of sustained Transforming Growth Factor-β1 (TGF-β1) exposure on HaCaT cells, an in vitro model for epidermal studies.
• To elucidate molecular and functional changes in keratinocytes under long-term TGF-β1 stimulation.
• To explore potential mechanisms contributing to wound chronification.

Main Methods:

• Utilized the HaCaT cell line as an in vitro model for epidermal physiology.
• Applied long-term treatment with TGF-β1 to HaCaT cells.
• Analyzed cellular morphology, actin filament and E-Cadherin organization, gene expression, protein content, R-Smad levels, and cell-cycle progression.

Main Results:

• Long-term TGF-β1 treatment induced significant morphological changes in HaCaT cells, including a spindle-shaped phenotype and increased size.
• Observed alterations in actin filaments and E-Cadherin, but without consolidated epithelial-to-mesenchymal transition.
• Detected modified gene expression, altered protein content, decreased Smad3 levels, and initial cell-cycle arrest that weakened over time.

Conclusions:

• Sustained TGF-β1 exposure significantly impacts keratinocyte phenotype and cell-cycle regulation.
• The study provides a framework for understanding molecular events in chronic wound development.
• Further research using this model can elucidate mechanisms driving wound chronification.