Molecular biological Research on mechanisms of refinoic acid for dermal wound healing and treatment of hyper pigmentation

结果提示，维甲酸对黑素细胞的黑素合成没有直接的抑制作用，也不影响黑素细胞、角质形成细胞和成纤维细胞之间的细胞间相互作用，如旁分泌黑素的作用。RA在漂白治疗中的作用似乎是其他特定的作用，如促进角质形成细胞的增殖和加速表皮周转。结果还显示，全反式维甲酸对HB-EGF mRNA的表达呈剂量依赖性升高，12h达高峰。这种升高在融合状态的角质形成细胞中比在亚融合状态的角质形成细胞中更显著，这表明分化的角质形成细胞比增殖的角质形成细胞更容易受到全反式维甲酸的刺激。Ral和Rol在10 0μM~1 mM时可上调HB-EGF，1~10μM时与ATRA相似。维甲酸上调HB-EGF的能力可能是开发和寻找具有最大益处和最小副作用的理想合成维甲酸的重要指标。

The results suggested that RA neither have direct inhibitory effects on melanogenesis of melanocytes, nor influence the cell-cell interactions between melanocytes, keratinocytes and fibroblasts, such as paracrine actions with regard to melanin productions. The role of RA in bleaching treatments appears to be other specific actions, such as promotion of keratinocytes proliferation and acceleration of epidermal turnover. The results also revealed that HB-EGF mRNA expression was elevated dose-dependently with atRA, most at 12 hours. This elevation was more prominent in keratinocytes of confluent state than those of subconfluent state, suggesting differentiated keratinocytes are more subject to be stimulated by atRA with regard to HB-EGF expression than proliferating keratinocytes. Ral and Rol was found to upregulate HB-EGF when used at 100 μM to 1mM, to a similar extent of atRA at 1 to 10 μM. The capacity of retinoids to upregulate HB-EGF may be an important index to develop and seek an ideal synthetic retinoid, which has maximum benefits and minimal side effects.