Tight junction regulates epidermal calcium ion gradient and differentiation
- Pola Chemical Industries Inc., 560 Kashio-cho, Totsuka-ku, Yokohama 244-0812 (Japan)
- Division of Fine Morphology, Core Research Facilities, The Jikei University School of Medicine, Minato-ku, Tokyo 105-8461 (Japan)
Research highlights: {yields} We disrupted epidermal tight junction barrier in reconstructed epidermis. {yields} It altered Ca{sup 2+} distribution and consequentially differentiation state as well. {yields} Tight junction should affect epidermal homeostasis by maintaining Ca{sup 2+} gradient. -- Abstract: It is well known that calcium ions (Ca{sup 2+}) induce keratinocyte differentiation. Ca{sup 2+} distributes to form a vertical gradient that peaks at the stratum granulosum. It is thought that the stratum corneum (SC) forms the Ca{sup 2+} gradient since it is considered the only permeability barrier in the skin. However, the epidermal tight junction (TJ) in the granulosum has recently been suggested to restrict molecular movement to assist the SC as a secondary barrier. The objective of this study was to clarify the contribution of the TJ to Ca{sup 2+} gradient and epidermal differentiation in reconstructed human epidermis. When the epidermal TJ barrier was disrupted by sodium caprate treatment, Ca{sup 2+} flux increased and the gradient changed in ion-capture cytochemistry images. Alterations of ultrastructures and proliferation/differentiation markers revealed that both hyperproliferation and precocious differentiation occurred regionally in the epidermis. These results suggest that the TJ plays a crucial role in maintaining epidermal homeostasis by controlling the Ca{sup 2+} gradient.
- OSTI ID:
- 22204848
- Journal Information:
- Biochemical and Biophysical Research Communications, Vol. 406, Issue 4; Other Information: Copyright (c) 2011 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0006-291X
- Country of Publication:
- United States
- Language:
- English
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