Galway Neuroscience Centre, School of Natural Sciences, National University of Ireland, Galway, Ireland.
Centre for Microscopy and Imaging, National University of Ireland, Galway, Ireland.
Sci Rep. 2016 Nov 3;6:36410. doi: 10.1038/srep36410.
Aberrant iron deposition in the brain is associated with neurodegenerative disorders including Multiple Sclerosis, Alzheimer's disease and Parkinson's disease. To study the collective response to iron loading, we have used hippocampal organotypic slices as a platform to develop a novel ex vivo model of iron accumulation. We demonstrated differential uptake and toxicity of iron after 12 h exposure to 10 μM ferrous ammonium sulphate, ferric citrate or ferrocene. Having established the supremacy of ferrocene in this model, the cultures were then loaded with 0.1-100 μM ferrocene for 12 h. One μM ferrocene exposure produced the maximal 1.6-fold increase in iron compared with vehicle. This was accompanied by a 1.4-fold increase in ferritin transcripts and mild toxicity. Using dual-immunohistochemistry, we detected ferritin in oligodendrocytes, microglia, but rarely in astrocytes and never in neurons in iron-loaded slice cultures. Moreover, iron loading led to a 15% loss of olig2-positive cells and a 16% increase in number and greater activation of microglia compared with vehicle. However, there was no appreciable effect of iron loading on astrocytes. In what we believe is a significant advance on traditional mono- or dual-cultures, our novel ex vivo slice-culture model allows characterization of the collective response of brain cells to iron-loading.
脑内铁沉积异常与包括多发性硬化症、阿尔茨海默病和帕金森病在内的神经退行性疾病有关。为了研究对铁负荷的集体反应，我们使用海马器官型切片作为平台，开发了一种新的铁积累的体外模型。我们在 12 小时内用 10 μM 硫酸亚铁铵、柠檬酸铁或二茂铁暴露 12 小时后，证明了铁的不同摄取和毒性。在该模型中确立了二茂铁的优越性后，然后将培养物用 0.1-100 μM 二茂铁负载 12 小时。与载体相比，1 μM 二茂铁暴露导致铁增加了 1.6 倍。这伴随着铁蛋白转录物增加 1.4 倍和轻微的毒性。通过双重免疫组织化学，我们在铁负荷切片培养物中检测到少突胶质细胞、小胶质细胞中的铁蛋白，但在星形胶质细胞中很少，在神经元中从未检测到。此外，与载体相比，铁负荷导致少突胶质细胞阳性细胞减少 15%，小胶质细胞数量增加 16%，激活程度增加。然而，铁负荷对星形胶质细胞没有明显影响。在我们认为是传统的单核或双培养的重大进展中，我们的新型体外切片培养模型允许对脑细胞对铁负荷的集体反应进行特征描述。
