Keratinocytes make up the outermost layer of the skin, called the epidermis. These cells produce the protein keratin, which gives skin its strength and flexibility.
Melanocytes give skin its colour by producing melanin, which is a pigment. Melanocytes are located in the epidermis, but they can also extend into the dermis, which is the layer of skin beneath the epidermis.
Langerhans cells are immune cells located in the epidermis. They help to protect the skin from infection and disease.
Stem cells divide to produce new stem cells and also undergo a process called differentiation to become skin cells. The differentiation of skin stem cells is controlled by a number of factors, including growth factors and hormones.
Skin stem cells are essential for the maintenance of healthy skin. As stem cells age, they lose some of their ability to divide and differentiate, which can lead to skin ageing. Ageing skin also exhibits several qualitative and quantitative changes that include:
- Reduced cellularity due to stem cell exhaustion.
- Decreased proliferation and migration of stem cells and their derivatives.
- Abnormal differentiation.
Researchers are currently investigating ways to use stem cells to treat skin diseases and conditions, such as wounds, burns, and vitiligo.
