Ponec M, Boonstra J
Department of Dermatology, University Hospital, Leiden, The Netherlands.
Dermatologica. 1987;175 Suppl 1:67-72. doi: 10.1159/000248862.
The relationship between keratinocyte differentiation capacity, lipid synthesis, plasma membrane composition and epidermal growth factor (EGF) binding has been studied in SCC-12F2 cells and normal keratinocytes. The differentiation capacity of the cells, i.e. ionophore-induced cornified envelope formation, was inhibited by various retinoids and stimulated by hydrocortisone. Retinoids that caused a significant reduction of cornified envelope formation, i.e. retinoic acid and 13-cis-retinoic acid, caused only minor changes in lipid synthesis and plasma membrane composition. Arotinoid ethyl sulfone, having a minor effect on cornified envelope formation, caused a drastic inhibition of cholesterol synthesis, resulting in changes in the plasma membrane composition. Hydrocortisone stimulated cornified envelope formation but had only minor effects on lipid synthesis and plasma membrane composition. Of all retinoids tested, only arotinoid ethyl sulfone caused a drastic increase of EGF binding, while hydrocortisone had no effect. The results presented in this study demonstrate that modulations in keratinocyte differentiation, as induced by retinoids or hydrocortisone, are not accompanied by comparable changes in EGF binding. It is concluded that EGF binding is most likely directly dependent upon the composition and properties of the plasma membrane. The effects of retinoids on EGF binding are thus caused by changes in the composition of the plasma membrane and not by modulation of capacity of cells to differentiate.
在SCC - 12F2细胞和正常角质形成细胞中，研究了角质形成细胞分化能力、脂质合成、质膜组成与表皮生长因子（EGF）结合之间的关系。细胞的分化能力，即离子载体诱导的角质包膜形成，受到各种维甲酸的抑制，并受到氢化可的松的刺激。导致角质包膜形成显著减少的维甲酸，即全反式维甲酸和13 - 顺式维甲酸，仅引起脂质合成和质膜组成的微小变化。对角质包膜形成影响较小的芳维甲酸乙酯砜，对胆固醇合成有强烈抑制作用，导致质膜组成发生变化。氢化可的松刺激角质包膜形成，但对脂质合成和质膜组成影响较小。在所有测试的维甲酸中，只有芳维甲酸乙酯砜使EGF结合显著增加，而氢化可的松则无影响。本研究结果表明，维甲酸或氢化可的松诱导的角质形成细胞分化调节，并未伴随EGF结合的相应变化。得出的结论是，EGF结合很可能直接取决于质膜的组成和性质。因此，维甲酸对EGF结合的影响是由质膜组成的变化引起的，而不是通过调节细胞的分化能力。
