Caroline Hutter | PubMed Health

PubMed2002

Epidermal stem cells.

The clinical implications of understanding epidermal stem cell biology abound. Thousands of burns victims across the world have benefited from early research into the proliferation of epidermal keratinocytes in vitro. Advances now indicate there are a number of stem cell repositories within the epidermis, two of which, the interfollicular epidermis and the bulge region of the hair follicle, may supply each other when damaged. This review details the progress made in the identification and characterisation of stem cells within the epidermis and discusses the molecules involved in the epidermal stem cell's choice of fate. Finally, the skin, like bone marrow, could be a readily accessible source of stem cells for therapeutic intervention and evidence of skin stem cell plasticity is highlighted.

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PubMed2002

A crucial role of beta 1 integrins for keratinocyte migration in vitro and during cutaneous wound repair.

Integrins are ubiquitous transmembrane receptors that play crucial roles in cell-cell and cell-matrix interactions. In this study, we have determined the effects of the loss of beta 1 integrins in keratinocytes in vitro and during cutaneous wound repair. Flow cytometry of cultured beta 1-deficient keratinocytes confirmed the absence of beta 1 integrins and showed downregulation of alpha 6 beta 4 but not of alpha v integrins. beta 1-null keratinocytes were characterised by poor adhesion to various substrates, by a reduced proliferation rate and by a strongly impaired migratory capacity. In vivo, the loss of beta 1 integrins in keratinocytes caused a severe defect in wound healing. beta 1-null keratinocytes showed impaired migration and were more densely packed in the hyperproliferative epithelium. Surprisingly, their proliferation rate was not reduced in early wounds and even increased in late wounds. The failure in re-epithelialisation resulted in a prolonged inflammatory response, leading to dramatic alterations in the expression of important wound-regulated genes. Ultimately, beta 1-deficient epidermis did cover the wound bed, but the epithelial architecture was abnormal. These findings demonstrate a crucial role of beta 1 integrins in keratinocyte migration and wound re-epithelialisation. Movies available on-line

Animals↗