What are Hair Follicle Stem Cells？

Hair follicles are the basic units that produce hair. The hair we see is actually made up of dead cells, while the cells at the root continuously grow, pushing the dead cells upward, which gives the appearance of hair growth. This indicates that hair growth requires a constant supply of new cells. Hair follicle stem cells act as the “mother” cells for all the cells within the follicle, differentiating to produce new cells and maintaining the normal function of the hair follicle.

Functions of Hair Follicle Stem Cells

Hair follicle stem cells are located in a specific area of the follicle known as the “bulge region,” near the opening to the sebaceous gland. These stem cells have several key characteristics:

Self-Renewal Ability

Hair follicle stem cells can undergo infinite self-division, generating new stem cells to maintain their population.

Multipotent Differentiation

These stem cells can differentiate into various cell types, including keratinocytes (which form the outer layer of the skin), hair matrix cells (which form hair), and sebaceous gland cells (which produce sebum to supply the skin with necessary oils).

Wound Healing Capability

Hair follicle stem cells can rapidly respond to external stimuli (such as injury or inflammation) by proliferating and differentiating to repair damaged tissue. For example, when skin is injured, they can migrate to the epidermis and differentiate into epidermal cells to help heal the wound.

The Importance of Hair Follicle Stem Cells for Hair Growth

Normal hair growth relies on the continuous functioning of healthy hair follicles, with hair follicle stem cells serving as the most crucial hub in this “hair factory.” They control cell generation, nutrient supply, and even wound repair. One of the fundamental causes of hair loss crises is the inactivity of hair follicle stem cells, which affects the normal hair growth cycle and leads to hair loss.

Conversely, stimulating the activation of hair follicle stem cells and ensuring their proper function can improve hair loss issues and promote hair growth.