Keratin 15 Promotes a Progenitor Cell State in Basal Keratinocytes of Skin Epidermis

This study established a Krt24-CreERT2 mouse line targeting outer bulge hair follicle stem cells, finding these cells crucial for hair follicle development and repair, particularly following ionizing radiation exposure.

The researchers reported that stress-induced keratins in human skin are expressed at lower levels than those in healthy skin and are co-regulated with genes involved in differentiation, inflammation, and immunity, rather than replacing keratins of normal differentiation or indicating cell proliferation.

This study re-analyzed single-cell RNAseq data from human and mouse skin, confirming and refining insights into keratin gene regulation during keratinocyte differentiation in epithelial tissues.

In this study, researchers found that the KLHL24-ΔN28 protein variant disrupts hair follicle stem cells in a mouse model, leading to premature hair loss by degrading keratin 15.

Mammalian organs regenerate using stem cells and cell plasticity, but this ability declines with age.

This review evaluates existing research on Keratin 15 to assess its validity as a marker for epidermal stem cells, reporting no new results.

This review discusses how research on keratin biology has enhanced the understanding of epidermolysis bullosa simplex and indicates potential new therapeutic approaches, but it presents no new experimental results.

This review discusses the reuse of molecular mechanisms involved in embryonic skin development for maintaining adult epidermal homeostasis and reports no new results.

Lgr5 is a marker for active, long-lasting stem cells in mouse hair follicles.

Stem cells are in deep skin layers, while differentiating cells are in shallow layers.

The K15 promoter effectively targets stem cells in the hair follicle bulge.

CD34 is a marker for isolating stem-like cells in mouse hair follicles.

This study found that keratin 15 expression is downregulated in hyperproliferative conditions like psoriasis and hypertrophic scars, suggesting it is not compatible with keratinocyte activation.

This study found that K15 is variably expressed in sheep and mouse hair follicles, with specific patterns suggesting a role in the early stages of keratinocyte differentiation.

This study found that keratin 19 may be a marker for skin stem cells, helping to characterize these cells in different conditions and potentially explaining variations in healing rates between children and adults.

This study reported that K14 expression patterns and keratin filament organization in human skin's hair follicles differ from those in the epidermis, indicating distinct differentiation programs.