Effects of granulocyte colony-stimulating factor on brain nerve in chronic cerebral ischemic rats / 中华老年医学杂志

ABSTRACT

Objective To explore the effects of granulocyte colony stimulating factor (G-CSF)on chronic cerebral ischemia in rats,and its possible mechanism.Methods Chronic cerebral ischemia (2-VO) model was prepared and bilateral external jugular veins were isolated.A total of 30 rats were divided into 2 groups at random sham group (received no intervention,n=15) and operative group (received G-CSF or PBS through external jugular vein injection,n=15).At 6 weeks after operation,the rats in operative group were divided into G--CSF group (received G-CSF 10 mg/L,1 ml · kg-1 · d-1,1 times every 24 h for,3 times) and PBS control group (received PBS 10 mg/L,1 ml ·kg 1 · d-11,1 times every 24 h for 3 times).At 8 weeks after the operation,morris water maze was carried out to evaluate the learning and memory ability of the rats.The cell proliferation,threedimensional vascular distribution,ischemic neuronal apoptosis,cell morphological changes in ischemic area and the plasma VEGF levels were detected to explore the possible mechanisms.Results In morris water maze,escape latency at the 2rd to 5th day were significantly lower in G-CSF group than the PBS group (all P＜0.05).The swimming time spent in the first quadrant in G-CSF group was significantly longer than the PBS group (P＜0.05).There was a significant difference in the number of BrdU positive cells in the ischemical area between the G-CSF group and the control group [(27.7±4.76) vs.(10.4 ± 3.7),P =0.030).Three-dimensional quantitative measurements of vascular structure showed that the capillary diameters was smaller in the G-CSF group than in the PBS group [(2.90±0.20) μm vs.(3.45±0.26) μm,P=0.020] and the number of branch points in the boundary regions of ischemia had a significant difference in the G-CSF group compared with the control group [(207.82±10.73) /0.002 mm3 vs.(162.10±9.31) /0.002mm3,P=0.005].Threedimensional cerebral vessel surface area in the ipsilateral hemisphere was increased in the G-CSF group compared with the PBS group [(86498±2896) μm2/0.002 mm3vs.(73976±3826) μm2/0.002 mm3,P=0.003].The number of apoptotic cells in G-CSF group was decreased compared with the PBS group [(32.10±6.70) vs.(56.30±11.20),F=11.89,P=0.043].The electron microscope morphological observations showed inflammatory edema in intercellular gap was significantly reduced in the G-CSF group compared with the PBS group.The level of plasma VEGF was significantly increased in the G-CSF group compared with the PBS group [(58.81±6.61) ng/L vs.(20.81±4.35)ng/L,P=0.025].Conclusions G--CSF can improve the learning and memory ability in the chronic cerebral ischemic rats,and its possible mechanism might involve the nerve protection and the vascular regeneration associated with the VEGF.There is a great prospect for G-CSF in the therapy of chronic cerebral ischemic disease.