Influence of human dermal fibroblasts on epidermalization

Area of Science:

• Dermal and epidermal biology
• Tissue engineering
• Cell biology

Background:

• Investigating the complex interactions between dermal and epidermal cells is crucial for understanding skin development and regeneration.
• Existing in vitro models often simplify the intricate extracellular matrix and cellular components of native skin.

Purpose of the Study:

• To investigate the impact of collagen matrix organization and the presence of dermal fibroblasts on epidermal growth in a simplified in vitro human skin model.
• To elucidate the specific mechanisms by which fibroblasts regulate epidermalization.

Main Methods:

• Reconstruction of a simplified living human skin model in vitro, comprising a dermal equivalent and an overlying epidermis.
• Culturing fibroblasts within a collagen matrix to assess matrix remodeling.
• Measuring epidermal growth in response to different conditions of the dermal equivalent (e.g., cell-free, dead fibroblasts, living fibroblasts, conditioned medium).

Main Results:

• Epidermal growth was significantly enhanced when the collagen matrix was reorganized by fibroblasts.
• The greatest epidermal growth occurred when living fibroblasts persisted within the collagen matrix.
• Epidermal growth also increased on cell-free collagen or matrices with dead fibroblasts when exposed to fibroblast-conditioned medium.

Conclusions:

• Fibroblasts play a dual role in regulating epidermalization: remodeling the extracellular matrix and secreting soluble factors that promote epidermal growth.
• These findings underscore the critical importance of fibroblasts in mediating dermo-epidermal interactions.
• The developed skin equivalent model offers a valuable tool for quantitatively studying these interactions.