Loertscher J A, Sadek C S, Allen-Hoffmann B L
Department of Pathology, University of Wisconsin Medical School, Madison, Wisconsin 53706, USA.
Toxicol Appl Pharmacol. 2001 Sep 1;175(2):114-20. doi: 10.1006/taap.2001.9201.
We have examined the effect of TCDD on the growth of normal human keratinocytes. TCDD is a ubiquitous environmental toxicant that causes a severe dermatopathology in humans, which is known as chloracne. The cell biological basis of this pathology remains unknown. We conducted growth experiments in preconfluent normal human keratinocytes with both low (0.05 mM) and standard (0.66 mM) extracellular calcium concentrations in the media. TCDD treatment reduced the number of adherent keratinocytes relative to controls in media containing 0.05 or 0.66 mM calcium. Based on these observations, we speculated that the decrease in the cell number of TCDD-treated cultures might be the result of increased apoptosis. Analysis of nucleosomal fragmentation, nuclear morphology, and caspase-3 activity in keratinocytes reveals no increase in the characteristics of apoptosis in response to TCDD treatment. We therefore conclude that TCDD impacts on keratinocyte homeostasis independent of apoptosis.
我们研究了2,3,7,8-四氯二苯并-对-二恶英（TCDD）对正常人角质形成细胞生长的影响。TCDD是一种普遍存在的环境毒物，可导致人类严重的皮肤病理学改变，即氯痤疮。这种病理学的细胞生物学基础尚不清楚。我们在培养基中分别含有低（0.05 mM）和标准（0.66 mM）细胞外钙浓度的未汇合正常人角质形成细胞中进行了生长实验。在含有0.05或0.66 mM钙的培养基中，与对照组相比，TCDD处理减少了贴壁角质形成细胞的数量。基于这些观察结果，我们推测TCDD处理的培养物中细胞数量的减少可能是细胞凋亡增加的结果。对角质形成细胞中的核小体片段化、核形态和半胱天冬酶-3活性的分析表明，TCDD处理后凋亡特征并未增加。因此，我们得出结论，TCDD对角质形成细胞内稳态的影响与细胞凋亡无关。
