Brégère Catherine, Fisch Urs, Sailer Martin H, Lieb Wolfgang S, Chicha Laurie, Goepfert Fabienne, Kremer Thomas, Guzman Raphael
Brain Ischemia and Regeneration, Department of Biomedicine and Department of Neurosurgery, University Hospital Basel, Basel, Switzerland.
Schulthess Clinic, Zürich, Switzerland.
Eur J Neurosci. 2017 Jul;46(2):1758-1767. doi: 10.1111/ejn.13612. Epub 2017 Jul 4.
Doublecortin (DCX) is a microtubule-associated protein widely used as an indicator of neurogenesis in immunohistochemical analyses of the postmortem adult brain. A recent study reported that DCX can be quantified in the cerebrospinal fluid (CSF) from healthy rats between postnatal day 0 (P0) and P30. However, it is currently unclear whether the concentration of DCX in the CSF (CSF-DCX) may represent a measure of endogenous neurogenesis. To address this question, this study examined the impact of a neonatal hypoxic-ischemic (HI) brain injury, known to induce neurogenesis, on CSF-DCX. HI was elicited at P7 in Sprague-Dawley rat neonates, and CSF was collected serially from the cisterna magna at P5 and P10, or at P10 and P15. A sandwich immunoassay was used to measure CSF-DCX. Brains from P10 neonates were analyzed immunohistochemically for neurogenesis and cell death markers. Mean CSF-DCX was significantly higher in HI- than in sham-exposed animals, at both P10 and P15. In the HI group at P10, CSF-DCX and stroke severity correlated positively. DCX immunoreactivity was increased in the ipsilateral neurogenic niches from the P10 HI brains in comparison with that of shams. The number of proliferative DCX-positive cells was higher in the ipsilateral hippocampal subgranular zone (SGZ) than in the HI contralateral or sham SGZ. Thus, neonatal HI brain injury disrupts the developmental time-course of DCX levels in the CSF. Our data suggest that the increased concentration of DCX in the CSF after neonatal HI is the result of both cellular injury and increased neurogenesis.
双皮质素（DCX）是一种微管相关蛋白，在成人死后大脑的免疫组织化学分析中被广泛用作神经发生的指标。最近一项研究报告称，在出生后第0天（P0）至P30的健康大鼠脑脊液（CSF）中可以对DCX进行定量。然而，目前尚不清楚脑脊液中DCX的浓度（CSF-DCX）是否可以代表内源性神经发生的一种度量。为了解决这个问题，本研究考察了已知可诱导神经发生的新生儿缺氧缺血（HI）性脑损伤对CSF-DCX的影响。在P7时对Sprague-Dawley新生大鼠诱发HI，并在P5和P10或P10和P15时从枕大池连续收集脑脊液。采用夹心免疫分析法测量CSF-DCX。对P10新生大鼠的大脑进行免疫组织化学分析，以检测神经发生和细胞死亡标志物。在P10和P15时，HI组的平均CSF-DCX均显著高于假手术组动物。在P10时的HI组中，CSF-DCX与中风严重程度呈正相关。与假手术组相比，P10 HI组大脑同侧神经发生龛中的DCX免疫反应性增加。同侧海马齿状回颗粒下区（SGZ）中增殖性DCX阳性细胞的数量高于HI对侧或假手术组的SGZ。因此，新生儿HI性脑损伤扰乱了脑脊液中DCX水平的发育时间进程。我们的数据表明，新生儿HI后脑脊液中DCX浓度升高是细胞损伤和神经发生增加共同作用的结果。
