Sygnecka Katja, Heine Claudia, Scherf Nico, Fasold Mario, Binder Hans, Scheller Christian, Franke Heike
Translational Centre for Regenerative Medicine (TRM), University of Leipzig, Philipp-Rosenthal-Straße 55, 04103 Leipzig, Germany; Rudolf Boehm Institute of Pharmacology and Toxicology, University of Leipzig, Härtelstr. 16-18, 04107 Leipzig, Germany.
Institute for Medical Informatics and Biometry, Dresden University of Technology, Fetscherstraße 74, 01307 Dresden, Germany.
Int J Dev Neurosci. 2015 Feb;40:1-11. doi: 10.1016/j.ijdevneu.2014.10.005. Epub 2014 Nov 4.
Calcium ions (Ca(2+)) play important roles in neuroplasticity and the regeneration of nerves. Intracellular Ca(2+) concentrations are regulated by Ca(2+) channels, among them L-type voltage-gated Ca(2+) channels, which are inhibited by dihydropyridines like nimodipine. The purpose of this study was to investigate the effect of nimodipine on neurite growth during development and regeneration. As an appropriate model to study neurite growth, we chose organotypic brain slice co-cultures of the mesocortical dopaminergic projection system, consisting of the ventral tegmental area/substantia nigra and the prefrontal cortex from neonatal rat brains. Quantification of the density of the newly built neurites in the border region (region between the two cultivated slices) of the co-cultures revealed a growth promoting effect of nimodipine at concentrations of 0.1μM and 1μM that was even more pronounced than the effect of the growth factor NGF. This beneficial effect was absent when 10μM nimodipine were applied. Toxicological tests revealed that the application of nimodipine at this higher concentration slightly induced caspase 3 activation in the cortical part of the co-cultures, but did neither affect the amount of lactate dehydrogenase release or propidium iodide uptake nor the ratio of bax/bcl-2. Furthermore, the expression levels of different genes were quantified after nimodipine treatment. The expression of Ca(2+) binding proteins, immediate early genes, glial fibrillary acidic protein, and myelin components did not change significantly after treatment, indicating that the regulation of their expression is not primarily involved in the observed nimodipine mediated neurite growth. In summary, this study revealed for the first time a neurite growth promoting effect of nimodipine in the mesocortical dopaminergic projection system that is highly dependent on the applied concentrations.
钙离子（Ca(2+)）在神经可塑性和神经再生中发挥着重要作用。细胞内Ca(2+)浓度受Ca(2+)通道调节，其中L型电压门控Ca(2+)通道可被尼莫地平等二氢吡啶类药物抑制。本研究旨在探讨尼莫地平对发育和再生过程中神经突生长的影响。作为研究神经突生长的合适模型，我们选择了中脑皮质多巴胺能投射系统的器官型脑片共培养物，该系统由新生大鼠脑的腹侧被盖区/黑质和前额叶皮质组成。对共培养物边界区域（两个培养切片之间的区域）中新生成神经突的密度进行定量分析，结果显示，浓度为0.1μM和1μM的尼莫地平具有促进生长的作用，其效果甚至比生长因子NGF更显著。当应用10μM尼莫地平时，这种有益作用消失。毒理学测试表明，在较高浓度下应用尼莫地平会轻微诱导共培养物皮质部分的半胱天冬酶3激活，但既不影响乳酸脱氢酶释放量或碘化丙啶摄取量，也不影响bax/bcl-2比值。此外，在尼莫地平处理后对不同基因的表达水平进行了定量分析。处理后，Ca(2+)结合蛋白、即早基因、胶质纤维酸性蛋白和髓鞘成分的表达没有明显变化，这表明它们表达的调节并非主要参与观察到的尼莫地平介导的神经突生长。总之，本研究首次揭示了尼莫地平在中脑皮质多巴胺能投射系统中具有促进神经突生长的作用，且该作用高度依赖于所应用的浓度。
