The osmolyte strategy of ageing skin

皮肤在整个身体和外部世界之间提供了一道屏障，防止失水。没有皮肤，作为陆地生物的生命是不可能的，因为水会不断地将皮肤留到外部环境中。虽然皮肤内调节水分流失的结构成分已有很好的特征，但调节表皮皮肤细胞内水分稳态的细胞机制-角质形成细胞-尚未完全被探索。皮肤细胞控制其稳态的一个机制是响应水分胁迫将有机渗透调节物质输送到细胞质中。除了保持水分外，渗透分子还具有其他功能，包括稳定蛋白质结构和抗氧化作用，这些都是整体细胞健康的基础。皮肤脱水在衰老过程中很常见，会导致干燥和炎症。我们的假设是，在衰老过程中，皮肤失去了合成或运输渗透调节物质的能力。对于其他较难获得的器官也是如此，因为调节细胞水分含量的能力对所有器官系统都是基本的。在这个项目中，我们将描述老年人和年轻人皮肤中渗透膜转运体的表达和分布，并研究特定渗透膜对老年人和年轻人培养的角质形成细胞中细胞体积控制、氧化还原平衡和蛋白质稳定性的影响。参考文献：El Chami等人(2011)实验皮肤病23(8)534-7

Skin provides a barrier between the entire body and the outside world that prevents uncontrolled water loss. Without skin, life as a terrestrial organism would be impossible because water would continually leave the skin to the outside environment. Although the structural components within skin regulating water loss are well characterised, the cellular mechanisms regulating water homeostasis within epidermal skin cells - keratinocytes - have yet to be fully explored.One mechanism by which skin cells control their homeostasis is the transport of organic osmolytes into the cytoplasm in response to water stress. Osmolytes also have other functions besides preservation of water including stabilisation of protein structure and antioxidant effects which are all fundamental to overall cellular health.Dehydration of the skin is common in ageing, leading to xerosis and inflammation. Our hypothesis is that during the process of ageing, the skin loses the ability to either synthesise or transport osmolytes. This may also be true for other less accessible organs as the ability to regulate cell water content is fundamental to all organ systems. In this project, we will characterise the expression and distribution of osmolyte transporters in aged versus young human skin and investigate the effects of specific osmolytes on cell volume control, redox balance and protein stability within keratinocytes cultured from aged and young individuals. This project may shed light on some of the mechanisms underlying one aspect of ageing, i.e. loss of hydration.Reference: El Chami et al (2011) Experimental Dermatology 23(8) 534-7