Systemic administration of low dosage of tetanus toxin decreases cell proliferation and neuroblast differentiation in the mouse hippocampal dentate gyrus
Systemic administration of low dosage of tetanus toxin decreases cell proliferation and neuroblast differentiation in the mouse hippocampal dentate gyrus
复制标题
全身给予低剂量破伤风毒素可降低小鼠海马齿状回细胞增殖和神经母细胞分化
作者：
B. Yan;I. Kim;J. Park;J. Ahn;Jeong;B. Chen;Jae‐Chul Lee;J. Choi;K. Yoo;Choong Hyun Lee;J. Cho;Jong‐Dai Kim;M. Won
在本研究中，我们研究了Tetaus毒素（泰特）对细胞增殖和神经母细胞分化的影响，使用特异性标记物：5-溴-2-脱氧尿苷（BrdU）作为细胞增殖的外源性标记物，Ki-67作为细胞增殖的内源性标记物，双皮质素（DCX）作为泰特处理后小鼠海马齿状回（DG）中神经母细胞的标记物。小鼠腹腔注射2.5和10 ng/kg泰特，并在治疗后15天处死。在两个TeT处理组中，使用神经元核（NeuN，神经元核标记物）和Fluoro-Jade B（F-J B，用于神经元变性定位的高亲和力荧光标记物），在DG的任何层中均未发生神经元死亡。此外，通过GFAP（星形胶质细胞的标志物）和Iba-1（小胶质细胞的标志物）免疫组织化学，在2.5和10 ng/kg TeT处理组中均未发现胶质细胞活化的显著变化。然而，在2.5 ng/kg TeT处理组中，BrdU、Ki-67和DCX免疫反应阳性细胞的平均数分别与对照组相比明显减少，并且在10 ng/kg TeT处理组中每种免疫反应阳性细胞的平均数减少更多。此外，DCX免疫反应阳性细胞的突起，其中投射到分子层，短于对照组。简而言之，我们目前的研究结果表明，低剂量（10 ng/kg）的泰特治疗明显降低细胞增殖和神经母细胞分化的小鼠海马DG没有明显的胶质细胞增生，以及任何损失的成年神经元。
In the present study, we investigated the effect of Tetaus toxin (TeT) on cell proliferation and neuroblast differentiation using specific markers: 5-bromo-2-deoxyuridine (BrdU) as an exogenous marker for cell proliferation, Ki-67 as an endogenous marker for cell proliferation and doublecortin (DCX) as a marker for neuroblasts in the mouse hippocampal dentate gyrus (DG) after TeT treatment. Mice were intraperitoneally administered 2.5 and 10 ng/kg TeT and sacrificed 15 days after the treatment. In both the TeT-treated groups, no neuronal death occurred in any layers of the DG using neuronal nuclei (NeuN, a neuron nuclei maker) and Fluoro-Jade B (F-J B, a high-affinity fluorescent marker for the localization of neuronal degeneration). In addition, no significant change in glial activation in both the 2.5 and 10 ng/kg TeT-treated-groups was found by GFAP (a marker for astrocytes) and Iba-1 (a marker for microglia) immunohistochemistry. However, in the 2.5 ng/kg TeT-treated-group, the mean number of BrdU, Ki-67 and DCX immunoreactive cells, respectively, were apparently decreased compared to the control group, and the mean number of each in the 10 ng/kg TeT-treated-group was much more decreased. In addition, processes of DCX-immunoreactive cells, which projected into the molecular layer, were short compared to those in the control group. In brief, our present results show that low dosage (10 ng/kg) TeT treatment apparently decreased cell proliferation and neuroblast differentiation in the mouse hippocampal DG without distinct gliosis as well as any loss of adult neurons.