Liu K, Kasper M, Bierhaus A, Langer S, Peterson I, Müller M, Trott K R
Department of Radiation Biology, St. Bartholomew's Hospital, London, UK.
Histochem Cell Biol. 1997 Feb;107(2):159-67. doi: 10.1007/s004180050100.
The role of the CD44s adhesion molecule, its epithelial isoforms and its relationship to epidermal proteoglycans such as syndecan was studied in normal and irradiated mouse skin. In normal mouse skin, only 10% of basal cells are strongly CD44s-immunopositive, with a cytoplasmic expression pattern. Double-label experiments with the basal cell marker keratin 14 confirmed the epithelial nature of the strongly CD44s-positive cell type in the basal layer. Some spinous keratinocytes and the majority of the remaining basal cells exhibited a weak membranous staining pattern. In contrast, the epithelial isoform, CD44v10, was strongly present in all basal and suprabasal epithelial cells of the epidermis, with a membranous staining pattern. Syndecan was found in the granular layer of the normal epidermis only. After 1 week of daily irradiation, the entire basal cell layer of the epidermis expressed CD44s in the membrane, but with a varying degree of staining intensity. This reactivity spread to the upper spinous layer after 3 weeks of treatment. In hyperproliferative epidermis, there was no difference in the staining patterns between CD44s and CD44v10. The expression of syndecan switched from the granular layer to the basal and lower spinous layers after 2 weeks of daily irradiation. Immunoreactivity for syndecan was also strongly enhanced in the dermis of irradiated samples. The results suggest an important role for syndecan and CD44 in proliferative processes during radiation-induced accelerated repopulation.
在正常和受辐照的小鼠皮肤中，研究了CD44s黏附分子、其上皮异构体及其与诸如syndecan等表皮蛋白聚糖的关系。在正常小鼠皮肤中，仅10%的基底细胞呈强CD44s免疫阳性，呈细胞质表达模式。用基底细胞标志物角蛋白14进行的双重标记实验证实了基底层中强CD44s阳性细胞类型的上皮性质。一些棘层角质形成细胞和其余大部分基底细胞呈现弱膜染色模式。相比之下，上皮异构体CD44v10在表皮的所有基底和基底上层细胞中均大量存在，呈膜染色模式。Syndecan仅在正常表皮的颗粒层中发现。每日辐照1周后，表皮的整个基底细胞层在细胞膜上表达CD44s，但染色强度不同。治疗3周后，这种反应性扩散到上棘层。在增生性表皮中，CD44s和CD44v10的染色模式没有差异。每日辐照2周后，syndecan的表达从颗粒层转移到基底和下棘层。辐照样本的真皮中syndecan的免疫反应性也显著增强。结果表明syndecan和CD44在辐射诱导的加速再增殖过程中的增殖过程中起重要作用。
