Sheets of embryonic epidermis can be isolated and cultured with or without the basal lamina

In the current study, we determine the concentration of Dispase II, a neutral protease, and the incubation time necessary for isolation of embryonic avian epidermis. The epidermis can be isolated from the dermis consistently with or without the basal lamina. Because the action of Dispase II is selective and easily controlled, this study suggests that Dispase can serve as a powerful tool for studying epidermal-extracellular matrix interactions. In further experiments we study the response of sheets of epidermis isolated with and without its basal lamina to extracellular matrix. When the epidermis is isolated without the basal lamina, the basal surface blebs and the actin in the basal cytoplasm are disrupted. Epidermis isolated without the basal lamina and cultured on extracellular matrix reorganizes the basal actin mat and retracts the blebs. However, epidermis isolated without the basal lamina and cultured in the absence of extracellular matrix continues to have blebs and a disorganized actin cortical mat. In contrast, the control epidermis isolated with the basal lamina retains a flat basal surface and organized actin cortical mat after culturing either with or without extracellular matrix. The extracellular matrix has been shown by many investigators to play an important role in cytoskeletal organization, metabolism, and differentiation. How the extracellular matrix interacts and influences these functions has not been completely elucidated. The ability to isolate tissue consistently with and without its basal lamina using Dispase II will facilitate addressing these and other epithelial cell biology questions.