The Effects Of Exercise On The Genes-related Expression Of Energy Metabolism Signal Pathway Regulated By P53

Cellular energy metabolism abnormality and the steady-state disorder of internal and external environment are the important reasons leading to cancer and diabetes. As the body's largest sports and endocrine organs,the adaptation of genes-related expression of energy metabolism signal pathway to long-term exercise in skeletal muscle is considered to a very important factor for preventing the development of tumor, insulin resistance and type II diabetes.As a tumor suppressor,cell-cycle checkpoint,the regulator of energy metabolism,and the balancer of oxidative stress, P53 lies in the center of many Cellular signaling pathway,and is their regulator,balanc-er,and integrator.Therefore,P53 has a very important role in regulating cellular energy metabolism,keeping oxidative stress balance and the steady-state of organism.One of the strategies is to maintain the gene expression steady-state of P53 for preventing cancer and premature aging.exercise can promote the body's metabolism,delay cellular senescence,reduce chances of cancerous cells,therefore,appropriate exercise may continue the P53 signal steady-state by regulating the signaling pathway of energy metabolism.Purpose:Training program of endurance training and sprint interval training and an acute endurance training were founded in the study,Endurance training model is based on a long,low-intensity and Sprint interval training model is based on short-term, high-intensity.one of the purposes is to determine the gene expression to training program in physiological and pathological conditions,expected to reveal the molecular mechanism of skeletal muscle cell's adaption to training program, and to explore the cause of keeping the balance of energy metabolism and oxidative stress from the level of gene expression,and to provide some evidences that exercise can improve the physiological function of skeletal muscle and promote the improvement and recovery of DM.Methods:40 male Sprague-Dawley rats were distributed into four groups:sedentary(CON,n=10),an acute endurance training(AE,n=10),endurance training(ET,n=10),sprint interval training(SIT,n=10).Endurance training consisted of 30-60min of continuous threadmill exercise at a lower intensity(<16.7m/min)per day,6 days/wk.Sprint interval training consisted of 9-10 repeats of a 10s"all ouf"threadmill test(≥42m/min)with 30-60s recovery between repeats,6 days/wk. After 6 weeks of either sprint interval or endurance training,the rats of group CON,ET and SIT were decapitated 24h after the last threadmill test.Group AE were administered similarly to Group CON in the 1-6wk,After an acute endurance training of 60min of continuous threadmill exercise at a lower intensity(<16.7m/min),the rats of Group AE were decapitated too.Blood was collected from heart,blood glucose,insulin, adiponectin,triglyceride,total cholesterol,glycated serum protein and glycolated hemoglobin were detected.The content of lactate,GSH and GSSG in gastrocnemius homogenate were measured by spectrophotometric assays.Real-time PCR was used to determine the mRNA content of P53,SCO2,SCO1,COXⅡ,TIGAR,HKII,PGM2, PDK4,PFKm,CPT1-β,AMPKa2,GLUT4 in gastrocnemius.Western blot was used to determine the protein content of P53,TIGAR,SCO2,SCO1,COXⅡin gastrocnemius.Results:(1) In the normal physiological conditions,AE,ET and SIT did not affect the blood glucose homeostasis and insulin resistance index from the overall level,but significantly downregulated the levels of total cholesterol,triglyceride,and glycosylated serum protein,ET also significantly increased adiponectin secretion.In the pathological conditions of diabetes,ET showd the sound effect in increasing adiponectin and reducing blood glucose,glycosylated serum protein,insulin resistance index and total cholesterol.(2) In the normal physiological conditions,AE,ET and SIT have no significant impact in both gene transcription and protein expression of P53.However,it Shows a different result in the pathological conditions,P53 gene transcription and protein expression were all significantly reduced.(3) In the normal physiological conditions,AE significantly increased SCO2 gene transcription,but had no effect in its protein expression,and had no effect in gene expression of SCO1 and COXⅡ.ET obviously upregulated the gene expression of SCO2 and SCOl,but had no effect in COXⅡ,however,ET clearly increased the protein expression of SCO2 and COXII.SIT had no effect in SCO2 gene transcription,but very significantly increased the gene transcription of SCO1 and COXII,in addition,SIT obviously upregulated the protein expression of SCO2 and COXⅡ.All AE,ET and SIT clearly elevated the ratio of GSH/GSSGIn the pathological conditions,ET have no effect in gene expression of SCO2 and SCOl,and significantly reduced the COXII protein expression,but the ratio of GSH/GSSG clearly elevated.(4)In the normal physiological conditions,AE significantly increased the gene transcription of TIGAR,PGM2,but had no effect in TIGAR protein expression and the content of lactate and the gene transcription of HKII and PFKm.ET clearly upregulated TIGAR gene expression from both gene transcription and protein expression,but had no effect in the content of lactate and the gene transcription of PGM2,HKII and PFKm.SIT very significantly increased the gene transcription of PFKm and the content of lactate,but had no effects in TIGAR gene expression and the gene transcription of PGM2,HKII and PFKm.In the pathological conditions,ET significantly increased the gene transcription of HKII,PFKm,GLUT4 and AMPKa2,but had no effect in gene expression of TIGAR,gene transcription of PGM2 and the content of lactate.(5) In the normal physiological conditions,AE very significantly reduced the gene transcription of PDK4,and had no effect in CPT-1β.ET very significantly reduced the gene transcription of PDK4 but very significantly increased the leval of CPT-1β.SIT clearly upregulated the gene transcription of both PDK4 and CPT-1β.In the pathological conditions,ET obviously downregulated the leval of PDK4,but had no effect in CPT-1β.Conclusions:(1) In the normal physiological conditions,in terms of the blood indicators,Exercise did not affect the body's normal physiological steady-state from the overall leval,and has a certain effect in improving the glucose and lipid metabolism.In the pathological conditions,ET may be an effective way to improve the high blood sugar symptoms of diabetes.(2) In the normal physiological conditions,exercise has no obvious effect in P53, its important role might be to promote the functions of regulation, inspection, balance, integration of P53,all of these were to maintain the normal physiological function.In the pathological conditions,ET downregulated the gene expression of P53.Might be affected by DM,the body's normal steady-state couldn't be maintained by P53,the downregulation might be to promote cell survival and delay the cell's apoptosis and aging of GK rats.(3) In the normal physiological conditions,the improvement of mitochondrial aerobic respiration induced by ET and SIT might be a good adaption to long-term training,but AE did the opposite.SCO1 gene expression seemed insensitive to training programe,the significant upregulation of gene transcription level might be the short-term stress response of the last training.As to the rise of GSH/GSSG under three exercise modes,exercise might have improved the environment of the body's redox.In the pathological conditions,ET seemed have no effective influence in mitochondrial aerobic respiration,speculating from the comprehensive results,its important role might be to promote the cell's survival.Therefore,we could make a conclusion that the important function of P53 is riot to enhance exercise ability but to save all forces to promote cell survival under the pathological conditions.(4) In the normal physiological conditions,the significant upregulation of TIGAR gene expression induced by ET Will help the body's energy metabolism shift to the more cost-effective aerobic respiration pathway,and is a good adaptation to ET. Training hadn't cause the adverse effects to the uptaking of glucose,the effective control of blood glucose homeostasis will have an important significance in maintaining normal physiological function of the body.The P53 steady-state induced by training seems keep the steady-state of P53 target gene in the glycolytic pathway, ET has a role in promoting mitochondrial respiration but has little impact on the glycolytic pathway.Lactic acid generation and PFKm gene transcription shows obvious increase,To some extent,the energy production induced by SIT is mainly likely to anaerobic metabolism,and this is consistent with its energy metabolism characteristics.ET downregulated the GK rats' ability of oxidative stress,this may be an contribution to diabetic rat cells'survival.(5) In the pathological conditions,ET may be significantly contribute to the glucose uptake ability of skeletal muscle through AMPK-GLUT4 glucose transport mechanism that is the energy-sensitive pathway,and this is a effective way to improve the high blood sugar.But considered the obvious downregulation of P53 gene expression,GLUT4 and HKII seem to have lost the direct inhibition by P53,and developed towards glycolysis,P53 also can not suppress glycolysis pathway by TIGAR.Although these changes reduced the blood sugar,it still may be induce the malignant lesions,it shows that the body is not well adapted to the training.the transduction pathway may occur some changes under the pathological conditions,in this study,ET may not be entirely beneficial to DM rats,the important significance of exercise to diabetes may be lies in prevention rather than treatment.(6) In the normal physiological conditions,ET significantly diminished the phosphorylation of PDK4 on the PDC,strengthened the pyruvate oxidation of skeletal muscle.At the same time,CPT-1βexpression very significantly increased,also strengthened the capacity of fatty acid oxidation.All these shows that ET is an effective way to activate mitochondrial respiratory. SIT may strengthen the phosphorylation of PDK4 on the PDC,which main energy supply is likely to glycolysis,but simultaneously increased the CPT-1βexpression.All these shows that SIT might be an effective way to activate mitochondrial respiratory too.In the pathological conditions,ET obviously reduced the PDK4 leval of GK rats,it was beneficial to GK rat's aerobic respiration,and is also a molecular basis that exercise can improve symptoms of diabetes.however,the CPT-1βgene expression hasn't occurred the same good adaptation to ET as the same as in the normal physiological conditions.(7)A11 comprehensive results shows that different training programe has the different effect,long-term exercise enables the body to produce the better adaptation. Compared with ET and SIT,both has a similar adaptation,thus,SIT may be a more effective way of saving time.(8)When organism is in training,not every factor follows its own necessary energy generation way in energy metabolism pathway regulated by P53,Especially in the pathological conditions of DM,some changes of GK rats induced by ET show the obvious characteristics of anaerobic energy supply,exercise does affected the energy metabolism pathway,some may be beneficial to body's retrieval and healthy,but others may be adverse.The impact induced by exercise is very complex,we couldn't make the simple conclusion that exercise is beneficial or harmful to the body from a few aspects but should consider from the comprehensive aspects.After all,the improvement of function from the overall leval is our ultimate goal.