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Androgenetic alopecia: new insights into the pathogenesis and mechanism of hair loss.

Sinclair R, Torkamani N, Jones L - F1000Res (2015)

Bottom Line: The hair follicle is a complete mini-organ that lends itself as a model for investigation of a variety of complex biological phenomena, including stem cell biology, organ regeneration and cloning.  The arrector pili muscle inserts into the hair follicle at the level of the bulge- the epithelial stem cell niche.  The arrector pili muscle has been previously thought to be merely a bystander and not to have an active role in hair disease.Computer generated 3D reconstructions of the arrector pili muscle have helped explain why women with androgenetic alopecia (AGA) experience diffuse hair loss rather than the patterned baldness seen in men.  Loss of attachment between the bulge stem cell population and the arrector pili muscle also explains why miniaturization is irreversible in AGA but not alopecia areata.A new model for the progression of AGA is presented.

View Article: PubMed Central - PubMed

Affiliation: Department of Medicine, University of Melbourne, Victoria, Australia ; Epworth Dermatology, Victoria, Australia ; Sinclair Dermatology, Victoria, Australia.

ABSTRACT
The hair follicle is a complete mini-organ that lends itself as a model for investigation of a variety of complex biological phenomena, including stem cell biology, organ regeneration and cloning.  The arrector pili muscle inserts into the hair follicle at the level of the bulge- the epithelial stem cell niche.  The arrector pili muscle has been previously thought to be merely a bystander and not to have an active role in hair disease. Computer generated 3D reconstructions of the arrector pili muscle have helped explain why women with androgenetic alopecia (AGA) experience diffuse hair loss rather than the patterned baldness seen in men.  Loss of attachment between the bulge stem cell population and the arrector pili muscle also explains why miniaturization is irreversible in AGA but not alopecia areata. A new model for the progression of AGA is presented.

No MeSH data available.


Related in: MedlinePlus

Reduction in dermal papilla cell numbers as an indirect result of changes to the dermal sheath.The sheath cells (solid cells) that surround the follicle are an integral part of the follicle dermis (a). If they are functionally lost (dotted cells indicated by arrows) from the follicle (b), then dermal papilla cells (outline only) move from the papilla to replace them (c). As a result, the papilla and the follicle become smaller. Reproduced with permission from John Wiley & Sons, Inc.12.
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f9: Reduction in dermal papilla cell numbers as an indirect result of changes to the dermal sheath.The sheath cells (solid cells) that surround the follicle are an integral part of the follicle dermis (a). If they are functionally lost (dotted cells indicated by arrows) from the follicle (b), then dermal papilla cells (outline only) move from the papilla to replace them (c). As a result, the papilla and the follicle become smaller. Reproduced with permission from John Wiley & Sons, Inc.12.

Mentions: Follicle cycling is associated with the movement of cells between the dermal papilla and dermal sheath12. It is thought that disruption of this process in AGA causes a loss of cells from the dermal sheath and then the dermal papilla that leads to hair follicle miniaturization (Figure 9). Cells from the dermal papilla and dermal sheath are capable of undergoing both smooth muscle and adipose differentiationin vitro. Cells from the follicle mesenchyme might also contribute to maintenance of the APM, and the muscle degeneration seen in AGA could be caused by the loss of a progenitor cell population that maintains both the APM and the dermal papilla.


Androgenetic alopecia: new insights into the pathogenesis and mechanism of hair loss.

Sinclair R, Torkamani N, Jones L - F1000Res (2015)

Reduction in dermal papilla cell numbers as an indirect result of changes to the dermal sheath.The sheath cells (solid cells) that surround the follicle are an integral part of the follicle dermis (a). If they are functionally lost (dotted cells indicated by arrows) from the follicle (b), then dermal papilla cells (outline only) move from the papilla to replace them (c). As a result, the papilla and the follicle become smaller. Reproduced with permission from John Wiley & Sons, Inc.12.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4544386&req=5

f9: Reduction in dermal papilla cell numbers as an indirect result of changes to the dermal sheath.The sheath cells (solid cells) that surround the follicle are an integral part of the follicle dermis (a). If they are functionally lost (dotted cells indicated by arrows) from the follicle (b), then dermal papilla cells (outline only) move from the papilla to replace them (c). As a result, the papilla and the follicle become smaller. Reproduced with permission from John Wiley & Sons, Inc.12.
Mentions: Follicle cycling is associated with the movement of cells between the dermal papilla and dermal sheath12. It is thought that disruption of this process in AGA causes a loss of cells from the dermal sheath and then the dermal papilla that leads to hair follicle miniaturization (Figure 9). Cells from the dermal papilla and dermal sheath are capable of undergoing both smooth muscle and adipose differentiationin vitro. Cells from the follicle mesenchyme might also contribute to maintenance of the APM, and the muscle degeneration seen in AGA could be caused by the loss of a progenitor cell population that maintains both the APM and the dermal papilla.

Bottom Line: The hair follicle is a complete mini-organ that lends itself as a model for investigation of a variety of complex biological phenomena, including stem cell biology, organ regeneration and cloning.  The arrector pili muscle inserts into the hair follicle at the level of the bulge- the epithelial stem cell niche.  The arrector pili muscle has been previously thought to be merely a bystander and not to have an active role in hair disease.Computer generated 3D reconstructions of the arrector pili muscle have helped explain why women with androgenetic alopecia (AGA) experience diffuse hair loss rather than the patterned baldness seen in men.  Loss of attachment between the bulge stem cell population and the arrector pili muscle also explains why miniaturization is irreversible in AGA but not alopecia areata.A new model for the progression of AGA is presented.

View Article: PubMed Central - PubMed

Affiliation: Department of Medicine, University of Melbourne, Victoria, Australia ; Epworth Dermatology, Victoria, Australia ; Sinclair Dermatology, Victoria, Australia.

ABSTRACT
The hair follicle is a complete mini-organ that lends itself as a model for investigation of a variety of complex biological phenomena, including stem cell biology, organ regeneration and cloning.  The arrector pili muscle inserts into the hair follicle at the level of the bulge- the epithelial stem cell niche.  The arrector pili muscle has been previously thought to be merely a bystander and not to have an active role in hair disease. Computer generated 3D reconstructions of the arrector pili muscle have helped explain why women with androgenetic alopecia (AGA) experience diffuse hair loss rather than the patterned baldness seen in men.  Loss of attachment between the bulge stem cell population and the arrector pili muscle also explains why miniaturization is irreversible in AGA but not alopecia areata. A new model for the progression of AGA is presented.

No MeSH data available.


Related in: MedlinePlus