The abstract to the paper begins by stating: 'Androgenetic alopecia (AGA), also known as common baldness, is characterized by a marked decrease in hair follicle size, which could be related to the loss of hair follicle stem or progenitor cells.'
Androgenic alopecia (AGA) is also known as androgenetic alopecia or alopecia androgenetica. AGA is a common type of hair loss that occurs in human females and males, along with chimpanzees and orangutans. In human males is is commonly referred to as male pattern baldness.
They added, 'To test this hypothesis, we analyzed bald and non-bald scalp from AGA individuals for the presence of hair follicle stem and progenitor cells. Cells expressing cytokeratin15 (KRT15), CD200, CD34, and integrin, Î±6 (ITGA6) were quantitated via flow cytometry.'
Flow cytometry is a technique for examining microscopic particles, such as cells and chromosomes, by suspending them in a fluid while an electronic detection device measures their numbers.
The researchers added, "High levels of KRT15 expression correlated with stem cell properties of small cell size and quiescence. These KRT15hi stem cells were maintained in bald scalp samples.'
'However, CD200hiITGA6hi and CD34hi cell populations '” which both possessed a progenitor phenotype, in that they localized closely to the stem cell-rich bulge area but were larger and more proliferative than the KRT15hi stem cells '” were markedly diminished.'
Thus, persons with larger and more of these stem cells were likely not to be bald, while those with smaller and fewer numbers of these stem cells were more likely to be bald.
They concluded, 'In functional assays, analogous CD200hiItga6hi cells from murine hair follicles were multipotent and generated new hair follicles in skin reconstitution assays. These findings support the notion that a defect in conversion of hair follicle stem cells to progenitor cells plays a role in the pathogenesis of AGA.'
In other words, these stem cells have turned off, which may lead to baldness.
Further research will be conducted to learn more about this possible relationship between these stem cells and baldness.