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Beta1 integrin-mediated adhesion signalling is essential for epidermal progenitor cell expansion
Aleksandra Piwko-Czuchra1, Heidi Koegel, Hannelore Meyer
1Max Planck Institute of Biochemistry, Department of Molecular Medicine, Martinsried, Germany.
Plos One
|May 9, 2009
Summary
Beta1 integrins are crucial for epidermal stem cell maintenance. Even when reduced, keratinocytes can compensate, especially during aging or wound healing, to maintain skin homeostasis.
Area of Science:
- Dermatology
- Cell Biology
- Integrin Biology
Background:
- Discrepancies exist between in vitro and in vivo studies on beta1 integrins' role in epidermal stem/progenitor cells.
- In vitro data highlight beta1 integrins' essential function in stem/progenitor cell expansion and differentiation.
- In vivo studies in mice suggest epidermis can form and be maintained without beta1 integrins.
Purpose of the Study:
- To resolve the discrepancy regarding beta1 integrins' function in epidermal homeostasis.
- To investigate the compensatory mechanisms in epidermal stem/progenitor cells when beta1 integrin levels are reduced.
Main Methods:
- Generated hypomorphic mice with reduced beta1 integrin levels in keratinocytes.
- Studied aged mice with complete skin-specific ablation of beta1 integrin.
- Analyzed keratinocyte proliferation during wound healing in mutant mice.
Main Results:
- Hypomorphic mice showed defects, but these attenuated with age due to compensatory cell expansion.
- Aged mice with complete beta1 ablation also showed rapid repopulation by beta1-expressing cells.
- Keratinocyte proliferation during wound healing accelerated the expansion of beta1 integrin-expressing cells.
Conclusions:
- Beta1 integrin expression is critical for epidermal progenitor cell expansion and maintaining skin homeostasis.
- Epidermal stem/progenitor cells exhibit compensatory mechanisms to overcome beta1 integrin downregulation.
- These findings underscore the vital role of beta1 integrins in skin regeneration and repair.
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