An Experimental Study Of RhG-CSF On Senescence Accelerated Mouse P10

Objective:To investigate the effects of recombinant human granulocyte colony stimulating factor (rhG-CSF) on the cognition disorders, the inhibition of the inflammatory response and the antiapoptosis of senescence accelerated mouse P10 (SAMP 10).Methods:1. Forty-eight SAMP10 were randomly divided into two groups: a control group and a rhG-CSF group. Mice in the rhG-CSF group were subjected to 100μg/(kg·d) rhG-CSF subcutaneously for 7 days, while mice in the control group were subjected to the same volume normal saline per day for 7days. Mouse were executed on the 7th,14th,28th,and 56th day after administration.2. Morris water maze test was done continuously for 5 days before administration and execution. And record the escaping latency and the percentage of swimming distance in the target quadrant of each mouse. The data was collected and analyzed by Morris water maze automatic image monitor and processing system.3. Executed the mouse by heart perfusion after Morris water maze test and make the Frontal lobe brain tissue into Paraffin slice. The expressions of TNF-α,iNOS and caspase-3 were detected by immunofluorescence. And the percentage, the area and the density of TNF-αpositive cells,iNOS positive cells and caspase-3 positive cells were respectively analysed by Image-pro Plus software.4. All the data were treated by SPSS 13.0 software, expressed as means±S.D.((x|-)±s) and analyzed by ONE-WAY ANOVA and two-sample t-test for independent samples, P<0.05 was taken as the statistical standard.Results:1. Cognitive Function Tests1.1 Place navigation: The escaping latency of control group increased obviously ; In the rhG-CSF group, there was no significant difference between each time point (P>0.05) ,while the escaping latency was shorter than the control group on the 14th day(P<0.05).1.2 Spatial probe test result: In the control group, the percentage of swimming distances in the target quadrant increased on the 28th, 56th day than before administration; In the rhG-CSF group, it was longer than the control group on the 14th and 28th day(P<0.05).2. The expression of TNF-α: Positive material is mainly distributed in the Frontal lobe brain cortex with the red fluorescent marker, located in the cytoplasm on each time point. Compared with the control group, the percentage, the area and the density of TNF-αpositive cells were significantly decline on the 14th, 28th, 56th day in the rhG-CSF group(P<0.05).3. The expression of iNOS: Positive material is mainly distributed in the Frontal lobe brain cortex with the red fluorescent marker, located in the cytoplasm on each time point. Compared with the control group, the percentage iNOS positive cells were significantly decline on the 14th, 28th, 56th day in the rhG-CSF group (P<0.05). The area of iNOS positive cells were decline on all the time points (P<0.05). Only on the 14th day, the density of iNOS positive cells had no significant difference compared with control group (P>0.05).4. The expression of Caspase-3: Positive material is mainly distributed in the Frontal lobe brain cortex with the red fluorescent marker, located in the cytoplasm on each time point. Compared with the control group, the percentage of Caspase-3 positive cells were significantly decline on the 14th, 28th day in the rhG-CSF group (P<0.05) and the area ,the density of Caspase-3 positive cells were declined on the 28th(P<0.05).Conclusion:1. rhG-CSF can improve the cognitive impairment of SAMP10, and delay the decline of its learning and memory ability.2. rhG-CSF can decrease the expression the positive cells of TNF-αand iNOS in the frontal cortex brain tissue of SAMP10 and significantly inhibit the inflammatory response of SAMP10.3. rhG-CSF can decrease the positive cells of caspase-3 in the frontal cortex brain tissue of SAMP10 and can inhibit the neuron apoptosis.