ABSTRACT
Objective To explore the effect of aerobic exercise on Wnt/β-Catenin pathway in the cerebral cortex and hippocampus of rats,so as to provide theoretical basis for conforming that aerobic exercise can improve the function of the nervous system.Methods Six-week-old Sprague-Dawley male rats were randomly assigned to a sedentary control group (CG) and an aerobic exercise group (EG).The rats in the EG group underwent an 8-week treadmill training and their cerebral cortex and hippocampus were isolated at 48h after the last exercise.The mRNA levels of Wnt,β-Catenin,LRP5,LRP6,Axin1,CK1 and GSK3β were analyzed using quantitative PCR,while the protein and phosphorylation levels were assayed using Western blotting.Results After 8 weeks of treadmill exercise,the average mRNA and protein levels of Wnt1 and Wnt3 in the EG group were significantly higher than those in the CG group.Although there were no significant differences in β-Catenin mRNA levels between EG and CG groups,the protein levels of β-Catenin in the EG group were significantly higher than those in the CG group.Meanwhile,the phosphorylation levels of β-Catenin Ser33/Ser37 and Thr41/Ser45 were significantly lower than those in the CG group.In the EG group,the mRNA and protein levels of LRP5 and LRP6 were significantly higher than those in the CG group,while those of Axin1 and CK1 were significantly lower than the CG group.Moreover,no significant differences were observed in the mRNA and protein levels of GSK3β between the two groups,but the phosphorylation levels of GSK3β Ser9 in the EG group were significantly higher than the CG group.Conclusion Aerobic exercises can increase the levels of Wnt and Wnt receptor,protein LRP5 and LRP6,decrease the levels of Axin1 and CK1,inhibit the activity of GSK3β,altogether lowering the pbosphorylation of β-Catenin to promote the stableness of β-Catenin.Therefore,the aerobic exercise can increase Wnt/β-Catenin pathway activity and activate the downstream gene transcription in the cerebral cortex and hippocampus of rats.
ABSTRACT
Objective To investigate the effects of aerobic exercise on tau phosphorylation and PI3K/ Akt pathway in the hippocampus of obese rats,and provide some theoretical basis for physical activity improving obesity-related neurological disorders.Methods Male Sprague-Dawley rats aged 3 weeks were randomly assigned to either a high-fat or a normal diet protocol for 12 weeks.Animals submitted to the high-fat diet were further divided into two groups:a sedentary group (HF-Sed) and an exercise group (HF-Ex).The rats fed the normal diet were also divided into a sedentary group (ND-Sed)and an exercise group (ND-Ex).The rats in the HF-Ex and ND-Ex groups underwent a treadmill training for 8 weeks.Then the hippocampus was isolated at 48h after the last exercise.The protein and phosphorylation levels of tau,glycogen synthase kinase 3β (GSK3β),phosphoinositide 3-kinase (PI3K) and Akt were assayed using Western blotting.Results After 12 weeks of feeding,55％ of rats in the high-fat diet group reached the conditions for the obesity model.After 8 weeks of treadmill exercises,in the HF-Sed group the phosphorylation level of tau was significanlty higher than that in the ND-Sed group,while in the HF-Ex group that was significantly lower than the HF-Sed group.Moreover,in the HF-Sed group the phosphorylation level of GSK3β Ser9 was significantly lower,and the phosphorylation level of GSK3β Tyr216 was significantly higher than the ND-Sed group,indicating the activity of GSK3β was significantly higher than the ND-Sed group.However,after 8 weeks of treadmill exercise,in the HF-Ex group the phosphorylation level of GSK3β Ser9 was signfiicantly higher,and the phosphorylation level of GSK3β Tyr216 was signficanlty lower than the HF-Sed group,indicating significantly lower activity of GSK3β than the HF-Sed group.Then,in the HF-Sed group the protein levels of PI3K p110 and p85 subunits,and the phosphorylation levels of Akt Thr308 and Ser473 were significantly lower than those in the ND-Sed group,indicating inhibited activity of the PI3K/Akt pathway.However,in the HF-Ex group the protein levels of PI3K p110 and p85 subunits and the phosphorylation levels of Akt Thr308 and Ser473 were significanlty higher than those in the HF-Sed group,showing the activity of PI3K/Akt pathway was enhanced.Conclusion Obesity induces tau hyperphosphorylation in the rats hippocampus and long-term aerobic exercises can reduce tau hyperphosphorylation by increasing PI3K/Akt pathway activity and inhibiting GSK3β activity.It has a positive effect on delaying the formation of neurofibrillary tangles and improving obesity-related neurological disorders.
ABSTRACT
Objective To investigate the effect of acute exhausted exercise in high temperature environment on the expression of myocardial HSP70 and plasma ANP level of in rats. Methods Forty eight male Sprague-Dawley rats was randomly and equally assigned to the following six groups:control group(C),exercise group(E),one-hour heat exposure group (H), heat exposure and exercise group (HE), exercise and 24 hours after exercise group(E'),heat exposure and 24 hours after exercise(HE'). Each group consisted of 8 rats. Rats in E,HE,E' and HE' ran on a treadmill until exhaustion, while rats in H and H' were exposed in a high temperature environment (33℃ ,50%RH) for one hour. Rats in C,E,HE and H were killed immediately after exercise or heat exposure. Rats in HE' and E' were killed 24 hours after exercise. Samples from myocardium and serum were collected for determining HSP70,ANP and CK-MB. Results(1) HSP70 levels in groups E and E' are significantly higher than that in group C(P<0.05 and P<0.01,respectively),and the level in group HE' is significantly higher than that in groups H and E'(P<0.01 );The HSP70 level in group H is significantly higher than that in group C. (2) The ANP and CK-MB levels in group E are Significantly higher than that in group C.and in group HE is higher than in group H (P<0.05);The HSP70 levels in group E' and HE' significantly decrease comparing to that in groups E and HE (P<0.01). Conclusions(1)Both heat exposure and exercise can induce the increased expression of myocardial HSP70 in rats and the peak expression is seen 24 hours after exercise. The increased expression of HSP70 may have protective effects on the heat-induced myocardial injury. (2) The increased ANP levels in plasma immediately after exhausted exercise improves the blood circulation in myocardium and hints the potential possibility of myocardial damage. However,the high temperature environment does not strengthen the increase of plasma ANP level that caused by exhaustive exercise.