G-CSF ameliorates neuronal apoptosis via the mTOR/p70S6K pathway after hypoxia-ischemia brain damage in neonatal rats
10.3760/cma.j.issn.1671-8925.2018.05.004
- VernacularTitle:G-CSF通过上调mTOR/p70S6K信号通路抑制新生大鼠HIBD后神经细胞凋亡
- Author:
Lu CHEN
1
;
Siyun SHU
;
Zhengyan WU
;
Lin MA
;
Jiang DU
;
Sieh John DUMBUYA
;
Wei LUO
;
Fei LI
;
Bin WANG
Author Information
1. 510282广州,南方医科大学珠江医院儿科中心,广州市炎症与免疫性疾病重点实验室
- Keywords:
Hypoxia-ischemia brain damage;
Granulocyte-colony stimulating factor;
mTOR/p70S6K signaling pathway;
Apoptosis
- From:
Chinese Journal of Neuromedicine
2018;17(5):450-456
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the effects of granulocyte-colony stimulating factor (G-CSF) on neuronal apoptosis after hypoxia-ischemia brain damage (HIBD) and the possible role of the mTOR/p70S6K signaling pathway in neonatal rats.Methods Ninety seven-day-old Sprague-Dawley rats were assigned into 5 equal groups (n=18):sham group,HIBD group,G-CSF group,rapamycin group and ethanol group by random number table method.Pups were subjected to unilateral carotid artery ligation followed by 2hrs hypoxia or sham surgery.HIBD animals received normal saline,G-CSF (50 μg/kg),G-CSF combined with rapamycin (250 μg/kg) or ethanol (vehicle for rapamycin).Pups were euthanized 48hrs post-HIBD to quantify the percentage of brain infraction area.The pathomorphologic changes in the hippocampal CA 1 area and cortex were observed by Nissl staining.Neuronal cell death was determined using terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL).mTOR,activated mTOR (p-mTOR),p70S6K,activated p70S6K (p-p70S6K),Cleaved Caspase-3 (CC3),Bax,and Bcl-2 were quantified using Western blot analysis.Results G-CSF treatment resulted in significantly reduced percentage of brain infraction area (P＜0.05) and neuronal apoptosis in the hippocampal CA1 area and cortex (P＜0.05) after HIBD in neonatal rats.However,rapamycin administration reversed the neuroprotective effect of G-CSF.G-CSF administration ameliorated the pathomorphologic damage in the ipsilateral hemisphere.Compared with the HIBD group,the Nissl stained neurons significantly increased in the G-CSF group (P＜0.05).Furthermore,G-CSF increased the expression ofp-mTOR,p-p70S6K and Bcl-2 but decreased the expression levels of CC3 and Bax in the ipsilateral hemisphere,which were all significantly reversed by rapamycin (P＜0.05).Conclusion G-CSF may attenuate caspase activation and reduce neuronal apoptosis by up-regulating the activity of mTOR/p70S6K signaling pathway after experimental HIBD in rat pups.
