Effects of extracellular calcium on the growth-differentiation switch in immortalized keratinocyte HaCaT cells compared with normal human keratinocytes
Effects of extracellular calcium on the growth-differentiation switch in immortalized keratinocyte HaCaT cells compared with normal human keratinocytes
复制标题
DOI：
10.1111/j.1600-0625.2008.00775.x
复制
发表时间：
2009-02-01
影响因子：
3.6
通讯作者：
Simon, Alain
中科院分区：
文献类型：
--
作者：
Micallef, Ludovic;Belaubre, Francoise;Simon, Alain
角质形成细胞的生长和分化开关受多种机制的密切调节，通常与增殖减少、细胞周期停滞在G 0/G1期和表皮分化标志物（如角蛋白1（K1）、角蛋白10（K10）和外皮蛋白）的表达相关。在体外，自发永生化的人角质形成细胞系HaCaT经常被用作研究角质形成细胞功能的模型。HaCaT细胞和正常人角质形成细胞（NHK）在一个较长的时间段的比较分化研究很少有报道。因此，我们研究了它们在13天内从增殖状态到分化状态的转变。由于培养条件涉及细胞反应的变化，将细胞培养在特定的培养基中角质形成细胞的生长和分化诱导细胞外钙浓度从0.09至1.2毫米。在NHK，除了钙诱导的形态变化和随之而来的增殖减少。对于HaCaT细胞，钙添加导致形态学变化，但以意想不到的方式，细胞比在低钙水平下培养时更具增殖性。HaCaT细胞过度增殖与细胞周期分析相关，显示S/G2-M期的积累。此外，RT-PCR和蛋白质印迹分析显示，与NHK相比，HaCaT细胞中分化标志物K1、K10和外皮蛋白的表达延迟。总之，即使钙诱导的分化与细胞增殖降低无关，HaCaT细胞仍具有分化特征。
The keratinocyte growth and differentiation switch, tightly regulated by several mechanisms, is generally associated with decreased proliferation, cell cycle arrest in G0/G1 phase and expression of epidermal differentiation markers, such as keratin 1 (K1), keratin 10 (K10) and involucrin. In vitro, the spontaneously immortalized human keratinocyte cell line HaCaT is often used as a model to study keratinocyte functions. Comparative differentiation studies between HaCaT cells and normal human keratinocytes (NHK) over an extended time-period have rarely been reported. Therefore, we studied their switch from a proliferating to a differentiated state over 13 days. As culture conditions involved changes in cellular responses, cells were cultured in a specific medium for keratinocyte growth and differentiation was induced by increasing extracellular calcium concentration from 0.09 to 1.2 mm. In NHK, addition of calcium-induced morphological changes and concomitant decreased proliferation. For HaCaT cells, calcium addition resulted in morphological changes, but in an unexpected manner, cells were more proliferative than when cultured at low calcium levels. HaCaT cell hyperproliferation correlated with cell cycle analysis, showing an accumulation in S/G2-M phases. Furthermore, RT-PCR and western blot analysis revealed a delay in the expression of the differentiation markers K1, K10 and involucrin in HaCaT cells compared with NHK. In conclusion, even though calcium-induced differentiation was not associated with a decreased cell proliferation, HaCaT cells conserved properties characteristic of differentiation.