Study On The Mechanism Of IL-15 In Exercise Intervention Of GLUT-4 Signaling Pathway In Skeletal Muscle Of Mice

Skeletal muscle is considered to be the largest organ in the human body,and its energy metabolism is complex.In recent years,a large number of experimental data show that skeletal muscle can express,synthesize and secrete a variety of biological signaling molecules,including regulatory peptides,cytokines and growth factors,etc.,and is an important endocrine organ.Interleukin-15(IL-15),which is secreted in large amounts in skeletal muscle,has been shown to have immune functions and plays a role in mitochondrial biogenesis,fat oxidation,myogenesis,and glucose uptake.IL-15 is highly expressed in skeletal muscle.Studies have shown that IL-15 can increase the expression of GLUT-4 on the cell surface by mediating the AMPK pathway in skeletal muscle,but whether exercise can activate IL-15 and interfere with the expression of GLUT-4 in skeletal muscle through IL-15,especially the signaling pathway,remains unclear.In this study,the effects of exercise intervention on GLUT-4 in skeletal muscle and its related pathways were studied through the establishment of endurance exercise mouse model,and the effects of IL-15 and its related pathways on GLUT-4 in skeletal muscle were further verified by the establishment of one-time exercise and/or injection of IL-15 intervention mouse model.1.Research methods1.1 Establishment of endurance exercise mouse modelSixteen male C57BL/6J mice(young mice 7 months old)were randomly divided into two groups: control group(C)and endurance training group(EN).The C group was fed normally,and the EN group received 12 weeks of platform endurance training.Endurance training: running on the platform: Firstly,2 days of adaptive running on the platform training is carried out to familiarize the animal with the running environment and training process,with an intensity of 5 meters per minute and a duration of 10 minutes.After that,moderate-intensity platform running training was carried out every morning with an intensity of 12 meters per minute for 60 minutes for 12 consecutive weeks.Wstern blot was used to detect the expression of IL-15/AMPK/AKT /AS160 /GLUT-4 protein in each group.The expression changes of P53 m RNA in each group of mice were detected by RT-PCR.1.2 Construction of one-time exercise and/or injection of IL-15 mouse modelThirty-two C57BL/6J male mice(young mice 7 months old)were randomly divided into four groups: quiet injection of PBS group(CP),quiet injection of IL-15group(CI),one-time exercise injection of PBS group(EAP),one-time exercise injection of IL-15 group(EAI).CP group was fed normally,while EAP group and EAI group were given one-time exercise of running platform(12m/min)for 60 minutes.Disposable exercise: running on the platform: Disposable exercise training was conducted one hour before sampling,with an intensity of 12 meters per minute and a duration of 60 minutes.Wstern blot was used to detect the expression of IL-15/AMPK/AKT /AS160 /GLUT-4 protein in each group.The expression changes of P53 m RNA in each group of mice were detected by RT-PCR.2.Results:2.1 Changes of protein expression level of IL-15 related signal pathway in endurance exercise mouse modelCompared with C group,the expression level of IL-15 in EN group was significantly higher(p < 0.01).P-AMPK/AMPK increased significantly(p < 0.01).P-AKT/AKT increased significantly(p<0.01).P-AS160/AS160 increased significantly(p<0.05),and the expression level of GLUT-4 increased significantly(p< 0.05).2.2 Changes of IL-15-related signal pathway protein expression level in mouse model of one-time exercise and/or injection of IL-15Compared with CP group,the expression level of IL-15 in EAI group was significantly higher(p< 0.01).The ratio of P-AMPK/AMPK increased significantly(p< 0.01).The ratio of P-AKT/AKT increased significantly(p < 0.01).The ratio of P-AS160/AS160 increased significantly(p < 0.01).The ratio of P-AKT/AKT in CI group increased(p < 0.05).The expression of GLUT-4 increased significantly(p<0.01).Compared with CI group,the expression level of IL-15 in EAI group increased(p < 0.05).The ratio of P-AMPK/AMPK increased(p < 0.05).The ratio of P-AKT/AKT increased(p < 0.01).The ratio of P-AS160/A160 increased(p < 0.05).The expression level of GLUT-4 increased(p <0.01).Compared with EAP group,the expression level of GLUT-4 in EAI group was higher(p <0.01).2.3 Detection of P53 m RNA expression by RT-PCRIn the endurance exercise mouse model,compared with the C group,the expression of P53 m RNA in the EN group was significantly decreased(p<0.01).Compared with CP group,the expression of P53 m RNA in EAI group was significantly decreased(p <0.01)in mice with one-time exercise and/or injection of IL-15.The expression of P53 m RNA in EAP group was decreased(p <0.01).Compared with CI group,P53 m RNA expression was decreased in EAI group(p <0.01).3.ConclusionIn the endurance exercise model,the exercise intervention increased the expression of IL-15,and at the same time the expression of GLUT-4 increased,suggesting that IL-15 may increase the expression of GLUT-4 through AMPK / AKT/ AS160 / signaling pathway.In a mouse model with one-time exercise and/or IL-15 injection,it was further verified that IL-15 may cause elevated GLUT-4 expression through the AMPK/AKT/AS160/ signaling pathway.