急性炎症改变多发性硬化症小鼠模型成年海马神经发生。
Acute inflammation alters adult hippocampal neurogenesis in a multiple sclerosis mouse model.
机构信息
Laboratory of Anatomy, Histology and Embryology, Faculty of Veterinary Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece.
出版信息
J Neurosci Res. 2013 Jul;91(7):890-900. doi: 10.1002/jnr.23226. Epub 2013 Apr 22.
Neural precursor cells (NPCs) located in the subgranular zone (SGZ) of the dentate gyrus (DG) give rise to thousands of new cells every day, mainly hippocampal neurons, which are integrated into existing neuronal circuits. Aging and chronic degenerative disorders have been shown to impair hippocampal neurogenesis, but the consequence of inflammation is somewhat controversial. The present study demonstrates that the inflammatory environment prevailing in the brain of experimental autoimmune encephalomyelitis (EAE) mice enhances the proliferation of NPCs in SGZ of the dorsal DG and alters the proportion between radial glial cells and newborn neuroblasts. The injection protocol of the cell cycle marker bromodeoxyuridine and the immunohistochemical techniques that were employed revealed that the proliferation of NPCs is increased approximately twofold in the SGZ of the dorsal DG of EAE mice, at the acute phase of the disease. However, although EAE animals exhibited significant higher percentage of newborn radial-glia-like NPCs, the mean percentage of newborn neuroblasts rather was decreased, indicating that the robust NPCs proliferation is not followed by a proportional production of newborn neurons. Significant positive correlations were detected between the number of proliferating cells in the SGZ and the clinical score or degree of brain inflammation of diseased animals. Finally, enhanced neuroproliferation in the acute phase of EAE was not found to trigger compensatory apoptotic mechanisms. The possible causes of altered neurogenesis observed in this study emphasize the need to understand more precisely the mechanisms regulating adult neurogenesis under both normal and pathological conditions.
神经前体细胞(NPCs)位于齿状回(DG)的颗粒下区(SGZ),每天产生数千个新细胞,主要是海马神经元,这些神经元整合到现有的神经元回路中。衰老和慢性退行性疾病已被证明会损害海马神经发生,但炎症的后果有些争议。本研究表明,实验性自身免疫性脑脊髓炎(EAE)小鼠大脑中普遍存在的炎症环境增强了背侧 DG 的 SGZ 中 NPC 的增殖,并改变了放射状胶质细胞和新生神经母细胞之间的比例。细胞周期标记物溴脱氧尿苷的注射方案和所采用的免疫组织化学技术表明,在疾病的急性期,EAE 小鼠背侧 DG 的 SGZ 中 NPC 的增殖增加了大约两倍。然而,尽管 EAE 动物表现出明显更高比例的新生放射状胶质样 NPC,但新生神经元的平均比例反而降低,表明 NPC 的大量增殖并不伴随着新生神经元的比例产生。在 SGZ 中增殖细胞的数量与患病动物的临床评分或大脑炎症程度之间检测到显著的正相关。最后,EAE 急性期的增强神经发生并没有引发代偿性细胞凋亡机制。在这项研究中观察到的神经发生改变的可能原因强调了需要更精确地理解正常和病理条件下调节成年神经发生的机制。