Formichi Patrizia, Radi Elena, Battisti Carla, Pasqui Annalaura, Pompella Gerarda, Lazzerini Pietro Enea, Laghi-Pasini Franco, Leonini Alessandra, Di Stefano Anna, Federico Antonio
Department of Neurological and Behavioural Sciences, University of Siena, Siena, Italy.
J Cell Physiol. 2007 Sep;212(3):737-43. doi: 10.1002/jcp.21070.
Globoid cell leukodystrophy or Krabbe disease (KD), is a hereditary disorder caused by galactosylceramidase deficiency. Progressive accumulation of psychosine is considered to be the critical pathogenetic mechanism of cell death in the Krabbe brain. Psychosine mechanism of action has not been fully elucidated. It seems to induce apoptosis in oligodendrocytes through a mitochondrial pathway and to up-regulate inflammatory cytokines production resulting in oligodendrocyte loss. Our aim was to evaluate the role of psychosine in apoptotic cell death and inflammatory response in a group of patients affected by KD using peripheral blood lymphocytes (PBLs) and peripheral blood mononuclear cells (PBMCs) as a cellular model. PBLs from KP and healthy controls were exposed to 20 microM psychosine and analysed by flow cytometry, agarose gel electrophoresis and fluorescence microscopy. Our results showed that psychosine induces apoptosis in PBLs through a mitochondrial pathway, but the apoptotic response was quite low especially KP. The role of psychosine in the up-regulation of cytokines (TNFalpha, IL8 and MCP1) has been evaluated by ELISA in PBMCs from KP and controls after stimulation with LPS and phytohemagglutinin. Both in basal condition and after LPS stimulation, cells from KP showed a significant increase in TNF-alpha production, reduced MCP1 levels and no modification in IL8. These results indicate that lymphomonocytes from KP had a basal proinflammatory pattern that was amplified by psychosine. In conclusion, the reduced apoptotic response and the atypical cytokine production observed in our experiments, suggest an involvement of inflammatory pattern in immune peripheral cells of KP.
球状细胞脑白质营养不良或克拉伯病（KD）是一种由半乳糖神经酰胺酶缺乏引起的遗传性疾病。半乳糖鞘氨醇的进行性积累被认为是克拉伯病脑部细胞死亡的关键发病机制。半乳糖鞘氨醇的作用机制尚未完全阐明。它似乎通过线粒体途径诱导少突胶质细胞凋亡，并上调炎性细胞因子的产生，导致少突胶质细胞丢失。我们的目的是使用外周血淋巴细胞（PBLs）和外周血单核细胞（PBMCs）作为细胞模型，评估半乳糖鞘氨醇在一组受KD影响患者的凋亡细胞死亡和炎症反应中的作用。将来自KD患者和健康对照的PBLs暴露于20微摩尔的半乳糖鞘氨醇，并通过流式细胞术、琼脂糖凝胶电泳和荧光显微镜进行分析。我们的结果表明，半乳糖鞘氨醇通过线粒体途径诱导PBLs凋亡，但凋亡反应相当低，尤其是KD患者。在用脂多糖（LPS）和植物血凝素刺激后，通过酶联免疫吸附测定（ELISA）评估了半乳糖鞘氨醇在KD患者和对照的PBMCs中细胞因子（肿瘤坏死因子α、白细胞介素8和单核细胞趋化蛋白1）上调中的作用。在基础状态和LPS刺激后，KD患者的细胞均显示肿瘤坏死因子-α产生显著增加，单核细胞趋化蛋白1水平降低，白细胞介素8无变化。这些结果表明，KD患者的淋巴细胞具有基础促炎模式，该模式被半乳糖鞘氨醇放大。总之，我们实验中观察到的凋亡反应降低和细胞因子产生异常，提示炎症模式参与了KD患者外周免疫细胞的活动。
