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Why do cells in the stratum corneum lose their nuclei?

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Learn how regenerative properties of the skin helps to protect the human body from the external environment — human skin Human skin, whose cells are generated continuously by the body, serves as a protective barrier between the inside of the human body and the environment.

The cells in the stratum corneum—the outermost layer of the epidermis—lose their nuclei and most other organelles as part of their final maturation process.1

As keratinocytes migrate from the deeper, living layers of the epidermis toward the skin surface, they undergo a transformation into dead, flattened cells known as corneocytes. During this transition, the cells become progressively packed with keratin, a structural protein, and lose their internal contents, including their nuclei and keratohyalin granules. This process allows the cells to form a thin, protective, and water-resistant barrier that shields underlying tissues from environmental damage, pathogens, and toxins. Once they reach the surface, these dead, keratin-filled cells are eventually shed through a process called desquamation.12