EPA attenuates ultraviolet radiation-induced downregulation of aquaporin-3 in human keratinocytes.

Eicosapentaenoic acid (EPA) is an omega-3 polyunsaturated fatty acid (ω-3 PUFA) that protects against photodamage and photocarcinogenesis in mammals. Aquaporin-3 (AQP3) is a water/glycerol transport protein that is found in basal layer keratinocytes. In this study, we have investigated the protective effect of EPA against ultraviolet B (UVB)-induced AQP3 downregulation in human keratinocytes.

Localization of the secretory granule marker protein chromogranin B in the nucleus. Potential role in transcription control.

Chromogranins A (CGA) and B (CGB) are two major Ca(2+) storage proteins of the secretory granules of neuroendocrine cells. Nevertheless, we found in the present study that CGB was also localized in the nucleus. In immunogold electron microscopy using bovine adrenal medullary chromaffin cells, it was found that the number of CGB-labeled gold particles localized per microm(2) of the nucleus was equivalent to 20% that of CGB-labeled gold particles localized per microm(2) of the secretory granules.