| Objective:(1)To investigate the age-related changes of rat motor function and the possible beneficial effects of treadmill training.(2)To study the correlation between the motor function of rats with the myocardial infarction areas and the cardiac functions after the cell therapyfor myocardial infarction(MI).(3)To study protective effects of BDNF for cadiac microvascular endothelial cells(CMECs)death under hypoxic environment.(4)To analyze the difference of expression profile between young CMECs and old CMECs using Ingenuity Pathway Analysis software(IPA)to reveal the genes,signaling pathways and regulating networks which are related to aged related death of CMECs.Methods:(1)S.D.rats of 2-month-old,8-month-old and 26-month-old were used to investigate motor function parameters,included forelimb grip strength,endurance,rearing count and scurry speed.The four parameters were assessed again after two weeks of treadmill training,then the change of the parameters were analyzed.(2)S.D.rats of 3-month-old were applied to establish MI and transplanted into the bone marrow mesenchymal stem cells(BMSC)and the cardiac telocytes(CTS)after MI.The PBS injected group was set as control.After two weeks,the cardiac functions of these rats were analyzed by echocardiogram.The four motor function parameters and the treadmill tolerant time were analyzed in the parallel individual.Then the infarct size was also analyzed in the parallel individual.The correlation between the motor function parameters and treadmill tolerant time and their infarct size and cardiac function parameters were analyzed respectively.(3)The CMECs were cultured under hypoxic ischemia environment.The cell vitality was detected with cck-8,and the apoptosis of the CMECs under ischemia was detected by flow cytometry.(4)The differential genes between young CMECs and old CMECs was analyzed by IPA to reveal the genes,signaling pathways and regulating networks which are related to aged related death of CMECs.Results:(1)The forelimb grip strength of 26-month-old rats was significantly lower than 2-month-old and 8-month-old rats.The differences were statistical significance.While the forelimb grip strength of 2-month-old rats was higher than 8-month-old rats,however,the difference was not statistical significance.For the endurance,rearing count and scurry speed of 2-month-old rats were higher than 8-month-old and 26-month-old rats.The differences were statistical significance.In addition,the endurance,rearing count and scurry speed of 8-month-old were higher than 26-month-old rats.The differences were statistical significance.After two-week treadmill training,the forelimb grip strength of 8-month-old group and 26-month-old group were higher than non-trained parallels.The differences were statistical significance.The rearing count of 2-month-old group and 8-month-old group was higher than the non-trained parallels.The differences were statistical significance.There is no statistical significance for the endurance and scurry speed comparing between non-trained and trained group.The total score of the motor function for 2-month-old group and 8-month-old group after training was slightly higher than their non-trained situation respectively.However,the difference was not statistical significance.For the 26-month-old group,the total score of the motor function after trained situation was higher than non-trained parallels.The difference was statistical significance.(2)The infarction size of BMCS-and CTs-treated group is smaller than the PBS control group.The difference was statistical significance.The cardiac function of BMCS-and CTs-treated group was improved compared with PBS group.However,there is no difference in cardiac function between the BMSC treated group and the CTS treated group.There was a negative correlation between the forelimb grip strength and the infarction size.The higher forelimb grip strength was,while the smaller the infarction area was.There was also a negative correlation between the treadmill tolerant time and the infarction size.The longer the time of the treadmill exercise was,the smaller the infarction area was.There was a negative correlation between the treadmill tolerant time and the final systolic diameters and the shrinkage volume of left ventricle.There was a positive correlation between the time of the treadmill exercise and the ejection fraction(EF)and the fractional shortening(FS)of left ventricle.There was a positive correlation between the forelimb grip strength and the ejection fraction(EF)and the fractional shortening(FS)of left ventricle.(3)The cell vitality of CMECs of the BDNF treated group,the Nec-1 treat group,or the Z-VAD-FMK treat group was higher than the control group under hypoxic & ischemia environment.The difference was statistical significance(p<0.05).In normoxia situation,the cell apoptosis rate and the necrosis rate of the BDNF treat group is lower than the control.In hypoxic & ischemia environment,the protective effect of BDNF for CMECs was not attributed to inhibit apoptosis.(4)IPA analysis revealed that the regulating network using TNF,IFGB1,NFKBIA,CCL1,CXCL3,CXCL2 and NR3C1 as key regulating genes was as important regulating network for controlling of apoptosis,necrosis and survival.TNF,IL10 and IFGB1 were the key genes for regulating of CMEC death pathway,which were interacted with other upstream and downstream genes.TNF,MMP9 and NFKBIA were the key genes for regulating of CMEC apoptosis,which were interacted with other upstream and downstream genes.Conclusions:(1)The motor function parameters(forelimb grip strength,endurance,rearing count and scurry speed)experienced age-related decline in rats.Importantly,treadmill training was able to partially restore the age-related decrease of total score of the motor function.(2)The forelimb grip strength and the treadmill tolerant time were able to be considered as the indirect parameters to reflect level of MI and cadiac function in rats.(3)No matter in hypoxic ischemia environment or in normoxia environment,BDNF was able to promote the survival of CMECs.The protective effect of BDNF for CMECs was not attributed to inhibit apoptosis.(4)The network using TNF,IFGB1,NFKBIA,CCL1,CXCL3,CXCL2 and NR3C1 as key regulating genes might be the key regulating network for CMEC necrosis and apoptosis. |
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