Neuroglobin Protects The Brain From Traumatic Injury

Neuroglobin (Ngb) is the third kind of O₂-binding globins, expressed preferentially in nervous tissues. Naturally, it was speculated that Ngb maybe play a neuroprotected role in hypoxia injury. Up to the present day, many studies revealed that the expression of Ngb was increased after traumatic brain injury (TBI), and over expressing Ngb by transgenic techniques could reduce the volume of brain infarct dramatically. All these result support the standpoint that Ngb protect brain from ischemia or hypoxia damage. But, there is no any research report on roles of Ngb in TBI until to now.Our previous study showed that expression of Ngb after trauma was increased significantly and related to some apoptosis proteins. It suggests that Ngb may play a role of neuroprotection in brain trauma. Therefore, the aim of this study was to explore whether Ngb protects brain from trauma. Firstly, we use recombinant adenovirus vector containing GFP-tagged Ngb (Ad-GFP-Ngb) to transfer Ngb gene into rats brain. Secondly, TBI was to be implemented. At last, the changes of injured brain pathology were assessed.I . To establish Feeney's weight-dropping model of moderate traumatic brain injury and observe the changes of expression of Ngb after trauma. We found that the expression of Ngb increased significantly in the area surrounding the core of injury and in the CA1 of ipsilateral hippocampus after TBI, and then we focused attention on the two areas.II. The aim was to investigate the transfection efficacy of GFP-tagged adenovirus vector (Ad-GFP) in cerebral cortex and hippocampus of rats. Results showed that cortex could be transduced efficaciously by Ad-GFP, which was infused into corpus callosum and delivered by means of retrograde transport. CA1 of Hippocampus could be totally transduced through multipoint injections. In a word, the Ad-GFP can meet our needs in this study.III. Ad-GFP-Ngb was constructed, and it was proved that the adenovirus transduce in a high efficiency way and expressed correctly by means of PCR, Western Blot and immunocytochemistry techniques in vitro and in vivo.IV. Rats were stereotaxically injected with Ad-GFP-Ngb into cortex and hippocampus, five days later, they suffered moderate TBI. We found the volume of injured brain was decreased distinctly compared with control group, cell loss and apoptosis in CA1 was improved significantly.Conclusions: Over expression of Ngb reduces TBI damage, maybe we can speculate that Ngb play a neuroprotective role in TBI.