Effect Of Different Hypoxic Training Modes On Signaling Pathway Of Mitochondrial Energy Metabolism Regulated By P53 In Skeletal Muscle Of Rats

Objective: The hypoxia exercise can improve the ability of blood to transport ox ygen and the muscle cells to utilize oxygen,and to achieve the purpose of improving aerobic endurance.p53 is a transcription factor that regulates the signal pathway of cell energy metabolism.When cells are stimulated by external hypoxia environment and exercise training,p53 plays an important role in regulating cell energy metabolism by maintaining the level of oxidative stress and the effect of biological homeostasis.The r espiratory function of mitochondria was enhanced by inducing cytochrome Coxidase(SCO2)and glutaminase 2(GLS2).In recent years,there are many researches on the relationship between exercise and mitochondrial energy metabolism,p53 regulating cell energy metabolism and oxidative stress,and mainly focusing on p53 regulation of energy metabolism,aging and apoptosis,mitochondrial biosynthesis,etc.There are little research on p53 regulation of energy metabolism signaling pathway after hypoxia training.p53 may play an important role in regulating the signal pathway of cell energy metabolism under hypoxia,and the proper exercise may be an effective means to maintain the homeostasis of p53 signaling pathway,a series of adaptive changes to the organism and promote cell oxidase.About the cell oxidase,regulation protein,myofibrillar protein have been changed obviously,and metabolism level of the body cells was induced to produce a good adaptive change.In this study,p53 on skeletal muscle mitochondria aerobic metabolism,oxidative stress regulation as the theoretical basis,combined with artif icial simulation of high altitude environment and different hypoxia training programs.In order to investigate the effects of different hypoxia training modes on p53 gene ex pression and protein content and p53 signal transcription factor SCO2,in skeletal muscle of rats,p53 regulation of energy metabolism signaling pathway related gene expressi on and enzyme activity was taken as the research focus.Effects of GLS2 and mtco1 gene expression and mitochondrial enzyme activity or enzyme content in skeletal muscle on the effects of different hypoxic training modes on organism.The physiological m echanism of maintaining oxidative stress balance and enhancing respiratory capacity of mitochondria is studied.The effects of different modes of hypoxia training on the adaptive changes of mitochondrial energy metabolism signaling pathway regulated by p53 in skeletal muscle of rats are summarized and analyzed.It provides some theoretical reference for the effective hypoxia training mode in improving the body function and improving the sports performance.Methods: According to the simulated low-pressure and low-oxygen training meth od,combined with three ways of hypoxic training models,including high living-low trai ning,low living-high-training,high living-high training-low training,and making the training schedule of experimental rats.50 Wistar male rats with two month were selected,the weight of rat was 180±20g,the common dry feed was raised,drinking water was free,the temperature of the animal raising room was 23?~25?,and the humidity is 40%~60%.The altitude of Lanzhou city in normoxic environment is 1500 m,and the simulated altitude of low pressure and hypoxia is 3500 m.The experimental objects were randomly divided into 5 groups(n=10): the control group low living-low training group(NN),high living-high training group(HH),high living-low training group(HN),low li ving-high training group(NH),and high living-high training-low training group(HHN),ac cording to the schedule of normoxic and hypoxia training,all rats were trained for 5weeks.After 5 weeks of training,all rats been given one day to rest and taking material in the next day.All rats are injected intraperitoneally and anesthetized according to their body weight and pentobarbital sodium solution as the dosage of 0.3mL/100 g.The blood 3~5mL was taken from the heart for the determination of three indexes of blood and the extraction of serum.Separate quadriceps femoris into liquid nitrogen forse veral hours and then to remove-80 ? refrigerator to be tested.The mitochondria of skeletal muscle were separated by tissue homogenate,protease digestion and differential centrifugation.The concentration of mitochondrial protein and the activity and content of mitochondrial enzyme in skeletal muscle were determined by BCA kit(Thermo S cience,23225).The gene expression of p53,GLS2,SCO2 and mtco1 are detected by q-PCR,and the protein expression of skeletal muscle are detected by Westernblot.Results:(1)At the end of first week training,the weight of rats in each group decreased.After 2 weeks of training,the weight of rats in HHN group decreased compared with that of HH group.After 4 weeks of training,the weight of HHN and NN decreased compared with that of HH group.After 5 weeks of training,compared with NH,the weigh t of skeletal muscle in HH group increased,but there is no significant change in other groups.(2)After 5 weeks of training,the number of blood RBC in HH group and HN group were higher than that in NN group.Compared with HH group,the number of RBC in HHN group are decreased.Compared with NN group,the number of blood WBC in HHN group,HH group,HN group and NH group are increased,compared with HH group,the Hb content of HHN group are lower than that of NN group,and the Hb content of HH group is higher than that of NN group.(3)After 5 weeks of training,the levels of serum ROS in HHN group,HH group and HN group are lower than those in NN group,while the serum ROS content in NH group were higher than that in NH group,and the serum ROS content in HHN group,HH group and HN group are lower than that in HHN group,HH group and HN group.Compared with NN group,the activity of serum SOD in HHN group,HH group and HN group are lower than that in NH group,and the serum SOD activity in HH group and HN group are lower than that in NH group.(4)After 5 weeks of training,the ?-KGDHC activity of skeletal muscle in HHN group,HN group and NH group is higher than that in HHN group,HN group and NH group,the ?-KGDHC activity in HHN group are higher than that in HH group,and the ?-KGDHC activity in HH group is lower than that in NH group.The activity of?-KGDHC in HH group is lower than that in NN group.Compared with NN group,the activity of COX? in skeletal muscle in HHN group,HN group and NH group are higher than that in HH group,and the activity of COX? in HHN group is higher than that in HN group and NH group,while that in HH group are lower than that in H HN group.Compared with NN group,the total activity of mitochondrial ATP synthetasein HHN group,HH group,HN group and NH group are higher than that in NH grou p,and that in HHN group,HH group and HN group is higher than that in HHN group,HH group and HN group.Compared with HH group,the total activity of mitochondrial ATP synthetase in HHN group is lower than that in HN group,and the total activity of ATP synthetase in HH group are higher than that in HH group.(5)After 5 weeks of training,the content of GLS2 in the skeletal muscle of the HHN group and the NH group are higher than that of the NN group,and the conten t of GLS2 in the skeletal muscle of the HHN group and the NH group is higher than that of the HH group,and the content of GLS2 in the skeletal muscle of the HH group is lower than that of the HN group.(6)After 5 weeks of training,the expression of p53 gene in the skeletal muscle of the HHN group,the HH group,the HN group and the NH group increased,and the content of the p53 protein in the HHN group,the HN group and the NH group are lower;compared with the NH group,the expression of the p53 gene in the skeletal muscle of the HHN group are increased,and the HN group is lower;compared with the HN group,The expression of p53 gene in skeletal muscle of HHN and HH group were high;compared with the HH group,the expression of p53 gene in skeletal muscle of HHN group is higher and the content of p53 protein is lower.In comparison with th e NN group,the HN group and the NH group,the HHN group and the HH group rat,Compared with HH group,the expression of SCO2 gene in skeletal muscle of HHN group is higher than that of NN group,and the expression of SCO2 protein of HHN group,HH group,HN group and NH group are higher than that of NN group,the express ion of SCO2 gene was higher than that of HHN group,HH group,HN group and NH group.Compared with NH group,the expression of SCO2 protein in HH group,HN group and HHN group were higher than that in HH group,and the level of SCO2 protein expression in HHN group are decreased.Compared with NN group,HN group and NH group,the expression of GLS2 gene in skeletal muscle in HHN group and HH group are increased,while GLS2 protein expression in HHN group and NH group are lower than that in HH group.Compared with HH group,the level of GLS2 gene expression in skeletal muscle in HHN group were increased and the level of GLS2 protein expression were decreased.Compared with NN group,HH group,HN group and NH group,the expression of mtco1 gene in ske letal muscle of HHN group are higher than that of NN group,HN group and NH group.Compared with NN group,HN group and NH group,the expression of mtco1 gene in HH group was decreased,HN group and HHN group.Compared with HH group and NH group,the expression of mtco1 gene in skeletal muscle of HN group were increased.Conclusions:(1)After first week of hypoxia training,the weight of rats have showed a decreasing trend,which is the most obvious in HHN group.After 5 weeks of hypoxia training,the weight of rats did not significantly change,which indicated that hypoxia training have no effect on the changing of weight in rats.(2)After hypoxia training,the weight of skeletal muscle have changed in different degrees,and the weight of skeletal muscle in HH group were obviously increased.The exercise ability is not correlated with weight of skeletal muscle,but closely related to capillary hyperplasia and swelling of muscle organelle.(3)After hypoxia training,the quantity of RBC and WBC in blood and the conte nt of Hb in blood were increased,the ability of hemoglobin to transport oxygen and the ability of aerobic exercise are enhanced.(4)After hypoxia training,the activity of SOD and the content of ROS compleme nt each other,and the antioxidative ability and the level of oxidative stress of the body are improved as a whole.(5)After hypoxia training,the activity of ?-KGDHC and COX? and ATP synthet ase in skeletal muscle of rats are increased,and the content of GLS2 enzyme were in creased,which resulted in the increase of ATP production and the enhancement of aerobic exercise capacity.The effect of HHN group is best.(6)After hypoxia training,the levels of p53,SCO2,GLS2 and mtco1 mtRNA genes expression are increased,the expression of its protein changed in different degrees.These results suggest that hypoxia training stimulates p53 to increase the content of target protein in mitochondrial energy metabolism pathway,which plays an important role in improving mitochondrial aerobic respiratory function.