| Radiation is a high-energy ray widely existing in our surroundings.It can induce senescence,apoptosis,autophagy disorder,synaptic structure degeneration and other damages through oxidative stress,PI3 K/Akt signaling pathway and cell membrane transport,growth Differentiation,survival,migration,and synapse formation are closely related.Radiation can cause abnormalities in the PI3 K/Akt pathway,and at the same time induce damage to brain cells and reduce the effectiveness of synaptic plasticity,thereby accelerating or leading to the occurrence of neurological diseases.Astragaloside IV(AS-?)is one of the main active ingredients of Astragalus.It has various functions such as anti-oxidation,anti-apoptosis/aging,anti-inflammatory,and regeneration promotion.In this thesis,60Co? rays were used to treat mice to construct an in vivo model of radiation-induced brain damage;UVA was used to stimulate PC12 cells to establish an in vitro model of radiation-induced nerve cell damage.This model was used to explore the protective mechanism of AS-? based on PI3 K/Akt signaling pathway against radiation-induced brain cell damage.It aims to provide basic data for the application of natural pharmaceutical active ingredients in nerve cell damage caused by radiation.Result:1.In vivo test:(1)The results of Nissl staining showed that compared with the Control group,the number of neurons in the DMSO + R group decreased significantly(P <0.001),and the Nissl body was lighter;The number of neurons in the AS-? + R group increased significantly(P <0.01),and the Nissl body staining was clearer.(2)HE staining results showed that compared with the Control group,the number and average area of neurons in the DMSO + R group decreased significantly(P <0.01;P <0.01),the nucleus was mostly irregular circular and the nuclear membrane boundary was blurred;compared with DMSO Compared with the R group,the number and average area of neurons in the AS-? + R group increased significantly(P <0.01;P <0.05),the number of round nuclei increased,and the nuclear membrane boundary was relatively clear.(3)Western Blotting results showed that compared with the Control group,the protein expression levels of PI3 K,PSD95,p-Akt-Ser473,p-GSK3?-Ser9,and p-CREB-Ser133 in the DMSO + R group were significantly reduced(P <0.01;P <0.01;P <0.01;P <0.01;P <0.01),GPR34,Akt,CREB and GSK3? protein expression levels were not different(P> 0.05;P> 0.05;P> 0.05;P> 0.05);compared with DMSO + R group,AS-? + R group PI3 K,PSD95,p-Akt-Ser473,p-GSK3?-Ser9 and p-CREB-Ser133 protein expression levels increased significantly(P <0.05;P <0.001;P <0.05;P <0.01;P <0.01),GPR34,Akt,CREB and GSK3? protein expression levels were not different(P> 0.05;P> 0.05;P> 0.05;P> 0.05).(4)RT-qPCR results showed that: Compared with the Control group,the Log2 R levels of Arc and c-fos mRNA in the DMSO + R group showed a downward trend,and the FC values showed a downward trend;compared with the DMSO + R group,the Arc in the AS-? + R group Log2 R levels with c-fos mRNA increased significantly(P <0.01;P <0.05),and FC values increased significantly(P <0.01;P <0.05).2.In vitro test:(1)Light microscope showed: Compared with Control group,the number and average length of PC12 cells in DMSO + R group decreased significantly(P <0.01;P <0.001),and the number of short fusiform or round cells increased;Compared with the DMSO + R group,the number and average length of PC12 cells in the AS-? + R group increased significantly(P <0.01;P <0.01),and the number of long spindle cells increased.(2)Immunofluorescence showed that the number and average length of PC12 cells in the DMSO + R group decreased significantly(P <0.001;P <0.01),and the number of short fusiform or round cells increased compared with the Control group;compared with the DMSO + R group In comparison,the number and average length of PC12 cells in the AS-? + R group increased significantly(P <0.05;P <0.05),and the number of long spindle cells increased.(3)Western Blotting results showed that compared with the Control group,the protein expression levels of PI3 K,PSD95,p-Akt-Ser473,p-GSK3 ?-Ser9,and p-CREB-Ser133 in the DMSO + R group were significantly reduced(P <0.001;P <0.01;P <0.01;P <0.01;P <0.01),GPR34,Akt,CREB and GSK3? protein expression levels were not different(P> 0.05;P> 0.05;P> 0.05;P> 0.05);compared with DMSO + R group The protein levels of PI3 K,PSD95,p-Akt-Ser473,p-GSK3?-Ser9,and p-CREB-Ser133 in the AS-? + R group increased significantly(P <0.001;P <0.01;P <0.01;P <0.01,P <0.01),GPR34,Akt,CREB and GSK3? protein expression levels were not different(P> 0.05;P> 0.05;P> 0.05;P> 0.05).(4)In the PI3 K inhibition experiment,Western Blotting and immunofluorescence results showed that compared with the Control group,the PI3 K protein level in the DMSO + R group decreased significantly(P <0.05),and the number and average length of PC12 cells were significantly reduced(P <0.001;P <0.01);compared with DMSO + R group,PI3 K protein level in AS-? + R group increased significantly(P <0.01),the number and average length of PC12 cells increased significantly(P <0.05;P <0.01);and AS Compared with the IV-R group,the PI3 K protein level in the AS-? + R + I group decreased significantly(P <0.001),and the number and average length of PC12 cells decreased significantly(P <0.01;P <0.001).Conclusion:1.Radiation can inhibit the PI3 K/Akt signaling pathway to induce brain cell damage,which can be antagonized after AS-? pretreatment.2.AS-? can effectively antagonize the brain cell damage caused by radiation.2.AS-? plays a protective role in the brain damage caused by radiation through the activation of PI3 K/Akt signaling pathway,and its mechanism may be related to the reduction of GSK3? protein activity and increase CREB protein activity,increase PSD95 protein expression and Arc,c-fos gene Transcription level. |
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