Beta1 integrin-mediated adhesion signalling is essential for epidermal progenitor cell expansion.
PLoS One
; 4(5): e5488, 2009.
Article
em En
| MEDLINE
| ID: mdl-19424505
ABSTRACT
BACKGROUND:
There is a major discrepancy between the in vitro and in vivo results regarding the role of beta1 integrins in the maintenance of epidermal stem/progenitor cells. Studies of mice with skin-specific ablation of beta1 integrins suggested that epidermis can form and be maintained in their absence, while in vitro data have shown a fundamental role for these adhesion receptors in stem/progenitor cell expansion and differentiation. METHODOLOGY/PRINCIPALFINDINGS:
To elucidate this discrepancy we generated hypomorphic mice expressing reduced beta1 integrin levels on keratinocytes that developed similar, but less severe defects than mice with beta1-deficient keratinocytes. Surprisingly we found that upon aging these abnormalities attenuated due to a rapid expansion of cells, which escaped or compensated for the down-regulation of beta1 integrin expression. A similar phenomenon was observed in aged mice with a complete, skin-specific ablation of the beta1 integrin gene, where cells that escaped Cre-mediated recombination repopulated the mutant skin in a very short time period. The expansion of beta1 integrin expressing keratinocytes was even further accelerated in situations of increased keratinocyte proliferation such as wound healing. CONCLUSIONS/SIGNIFICANCE:
These data demonstrate that expression of beta1 integrins is critically important for the expansion of epidermal progenitor cells to maintain epidermal homeostasis.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Células-Tronco
/
Transdução de Sinais
/
Integrina beta1
/
Epiderme
/
Células Epidérmicas
Limite:
Animals
Idioma:
En
Ano de publicação:
2009
Tipo de documento:
Article