Doycheva Desislava M, Hadley Tiffany, Li Li, Applegate Richard L, Zhang John H, Tang Jiping
Department of Physiology & Pharmacology, Loma Linda University School of Medicine, Loma Linda, CA, USA.
Department of Anaesthesiology, Loma Linda University School of Medicine, Loma Linda, CA, USA.
Neurobiol Dis. 2014 Sep;69:192-9. doi: 10.1016/j.nbd.2014.05.024. Epub 2014 May 27.
Neonatal hypoxia ischemia (HI) is an injury that can lead to neurological impairments such as behavioral and learning disabilities. Granulocyte-colony stimulating factor (G-CSF) has been demonstrated to be neuroprotective in ischemic stroke however it has also been shown to induce neutrophilia, ultimately exacerbating neuronal injury. Our hypothesis is that coadministration of anti-neutrophil antibody (Ab) with G-CSF will decrease blood neutrophil counts thereby reducing infarct volume and improving neurological function post HI brain injury.
Rat pups were subjected to unilateral carotid artery ligation followed by 2.5h of hypoxia. Animals were randomly assigned to five groups: Sham (n=15), vehicle (HI, n=15), HI with G-CSF treatment (n=15), HI with G-CSF+Ab treatment (n=15), and HI with Ab treatment (n=15). Ab (325μg/kg) was administered intraperitoneally while G-CSF (50μg/kg) was administered subcutaneously 1h post HI followed by daily injections for 3 consecutive days. Animals were euthanized at 96h post HI for blood neutrophil counts and brain infarct volume measurements as well as at 5weeks for neurological function testing and brain weight measurements. Lung and spleen weights at both time points were further analyzed.
The G-CSF treatment group showed tendencies to reduce infarct volume and improve neurological function while significantly increasing neutrophil counts. On the other hand, the G-CSF+Ab group significantly reduced infarct volume, improved neurological function and decreased neutrophil counts. The Ab alone group showed reversal of the neuroprotective effects of the G-CSF+Ab group. No significant differences were found in peripheral organ weights between groups.
Our data suggest that coadministration of G-CSF with Ab not only prevented brain atrophy but also significantly improved neurological function by decreasing blood neutrophil counts. Hence the neuroprotective effects of G-CSF may be further enhanced if neutrophilia is avoided.
新生儿缺氧缺血（HI）是一种可导致行为和学习障碍等神经功能障碍的损伤。粒细胞集落刺激因子（G-CSF）已被证明在缺血性卒中中具有神经保护作用，但也已显示其可诱导中性粒细胞增多，最终加剧神经元损伤。我们的假设是，抗中性粒细胞抗体（Ab）与G-CSF联合给药将降低血液中性粒细胞计数，从而减少梗死体积并改善HI脑损伤后的神经功能。
将幼鼠进行单侧颈动脉结扎，随后缺氧2.5小时。动物被随机分为五组：假手术组（n = 15）、溶剂对照组（HI，n = 15）、HI + G-CSF治疗组（n = 15）、HI + G-CSF + Ab治疗组（n = 15）和HI + Ab治疗组（n = 15）。HI后1小时，腹腔注射Ab（325μg/kg），同时皮下注射G-CSF（50μg/kg），随后连续3天每日注射。HI后96小时处死动物，进行血液中性粒细胞计数和脑梗死体积测量，在5周时进行神经功能测试和脑重量测量。进一步分析两个时间点的肺和脾重量。
G-CSF治疗组显示出减少梗死体积和改善神经功能的趋势，同时中性粒细胞计数显著增加。另一方面，G-CSF + Ab组显著减少梗死体积，改善神经功能并降低中性粒细胞计数。单独使用Ab组显示出G-CSF + Ab组神经保护作用的逆转。各组之间外周器官重量未发现显著差异。
我们的数据表明，G-CSF与Ab联合给药不仅可预防脑萎缩，还可通过降低血液中性粒细胞计数显著改善神经功能。因此，如果避免中性粒细胞增多，G-CSF的神经保护作用可能会进一步增强。
