Adverse neurodevelopmental effects of dexamethasone modeled in PC12 cells: Identifying the critical stages and concentration thresholds for the targeting of cell acquisition, differentiation and viability
Adverse neurodevelopmental effects of dexamethasone modeled in PC12 cells: Identifying the critical stages and concentration thresholds for the targeting of cell acquisition, differentiation and viability
复制标题
DOI：
10.1038/sj.npp.1300967
复制
发表时间：
2006-08-01
影响因子：
7.6
通讯作者：
Slotkin, Theodore A.
中科院分区：
文献类型：
--
作者：
Jameson, Ruth R.;Seidler, Frederic J.;Slotkin, Theodore A.
使用地塞米松（DEX）预防早产儿呼吸窘迫被怀疑会产生神经行为缺陷。我们使用PC 12细胞模型的DEX对神经元发育的不同阶段的影响，利用从24小时到11天的曝光和浓度从0.01到10 μ M，模拟亚治疗，治疗和高剂量方案。在未分化的细胞中，即使在最低浓度下，DEX也抑制DNA合成，并通过DNA含量评估细胞数量产生进行性缺陷，而细胞生长（通过总蛋白与DNA比率评估）和细胞活力（台盼蓝排除）得到促进。当细胞分化开始与神经生长因子，同时列入DEX仍然产生了一个渐进的赤字，细胞数量和促进细胞生长和活力，同时延缓神经炎预测的发展，监测膜/总蛋白的比例。同样，即使0.01 μ M DEX也有效。接下来，我们通过引入神经生长因子4天，然后共暴露于DEX来评估中期分化的效果。虽然对细胞数量、生长和神经突延伸的影响仍然可以检测到，但结果通常不太明显。DEX还将PC 12细胞的命运从胆碱能表型向肾上腺素能表型转移，在分化开始时达到最大效果。我们的研究结果表明，DEX直接破坏神经元细胞的复制，分化和表型，在低于早产儿治疗所需的浓度，提供了糖皮质激素的使用和神经发育后遗症之间的机制联系。
The use of dexamethasone (DEX) to prevent respiratory distress in preterm infants is suspected to produce neurobehavioral deficits. We used PC 12 cells to model the effects of DEX on different stages of neuronal development, utilizing exposures from 24 h up to I I days and concentrations from 0.01 to 10 mu M, simulating subtherapeutic, therapeutic, and high-dose regimens. In undifferentiated cells, even at the lowest concentration, DEX inhibited DNA synthesis and produced a progressive deficit in the number of cells as evaluated by DNA content, whereas cell growth (evaluated by the total protein to DNA ratio) and cell viability (Trypan blue exclusion) were promoted. When cell differentiation was initiated with nerve growth factor, the simultaneous inclusion of DEX still produced a progressive deficit in cell numbers and promoted cell growth and viability while retarding the development of neuritic projections as monitored by the membrane/total protein ratio. Again, even 0.01 mu M DEX was effective. We next assessed effects at mid-differentiation by introducing nerve growth factor for 4 days followed by coexposure to DEX. Although effects on cell number, growth, and neurite extension were still detectable, the outcomes were generally less notable. DEX also shifted the fate of PC 12 cells away from the cholinergic phenotype and toward the adrenergic phenotype, with the maximum effect achieved at the outset of differentiation. Our results indicate that DEX directly disrupts neuronal cell replication, differentiation, and phenotype at concentrations below those required for the therapy of preterm infants, providing a mechanistic link between glucocorticoid use and neurodevelopmental sequelae.