| Objective: To establish the model of OSAS rats and interfere TGF-?1by specific inhibitor,observe the cognitive function of OSAS rats in 1W?2W?3W?4W and P144 groups and the pathological changes of neurons in CA1 and CA3 areas of hippocampus,study the protein localization and expression level of TGF-?1?Smad3and its active form p Smad3 in hippocampus of OSAS cognitive dysfunction rats,and clear the effect of TGF-?1/Smad3 signaling pathway on OSAS cognitive dysfunction and TGF-?1 regulation.Methods: 42 adult male Sprague-Dawley rats were randomly assigned seven groups,6 in the normal group,24 in the obstructive sleep apnea syndrome group,and at four time points: 1W?2W?3W?4W,6 in each group,6 in the 4W+TGF-?1 specific inhibitor disitertide group,6 in the 4W+dimethyl sulfoxide solution control group.The pathophysiological changes of OSAS was simulated by Chronic intermittent hypoxia.Rats in each group were assessed by Morris water maze after the OSAS model were successfully established.Nissl staining were used to observe Histopathological changes of hippocampal CA1 and CA3 areas in each group.Immunohistochemistry and protein imprinting Western Blot were used to locate and quantitatively detect TGF-?1?Smad3 and p Smad3 proteins in the hippocampal tissues of rats in each group.Results:1.During the model construction,all of the rats in OSAS?4W+P144?4W+DMSO group had symptoms such as irritability?deepening?increased frequency?head-up of breathing?daytime sleepiness?snoring and wakefulness.The blood pressure saturation of rat tail artery during hypoxia was(67.61±7.03)%,during reoxygenation period(95.44±2.71)%,the hypoxia-reoxygenation phase decreased by >4%,P<0.05,which was consistent with the OSAS model construction success criteria.2.MWM experiment results: Compared with the normal group,there was no significant changes both in the escape latency to look for concealed platform time in the pool and the number of crossing platforms in the space exploration(P>0.05),The difference was not statistically significant;while the time of CIH 2W?CIH 3W?CIH4W three time points rats looking for the concealed platform in the pool was prolonged(P<0.05),and positively correlated with intermittent hypoxia time(P<0.05),the difference was statistically significant;the number of crossing the platform was decreased(P<0.05),and negatively correlated with intermittent hypoxia time(P<0.05),the difference was statistically significant;Compared with 4W+DMSO group,the time of the concealed platform in the 4W+P144 group was reduced(P<0.05),the number of crossing platforms was increased(P<0.05),and the difference was statistically significant.3.NS experiment results: Large numbers of Nissl bodies in rat hippocampal CA1 and CA3 areas of the N group,the structure was complete,the cytoplasm was deeply stained,and the nucleus was liebetween.Compared with the N group,the OSAS group had a partial cell structure breakdown and a reduced number of Nissl bodies,The cytoplasm was mildly colored,the cells changed from multipolar to round,and the nuclear shifted.Eventually,the Nissl bodies disappeared.Compared with the DMSO group,the P144 group had more Nissl bodies,the cytoplasm was darker in color,and the structure was more complete.The damage was relatively small.4.IHC experiment results: TGF-?1?t Smad3 and p Smad3 were positively expressed in nerve cells.The stained cells were mainly brown.Among them,TGF-?1 was primarly distributed in the cell matrix,t Smad3 was distributed in the cell membrane,and p Smad3 was distributed in the cell membrane.nucleus and cytoplasm.5.WB experiment results: The expressions of TGF-?1?t Smad3 and p Smad3 were detected in the hippocampus of rats in each group.Compared with the N group,the expressions of TGF-?1and p Smad3 in the four time points of 1W,2W,3W and 4W were increasingly increased(P<0.05),the difference was saliently significant,while the expression of t Smad3 did not saliently change(P>0.05).Compared with4W+DMSO control group,the expression of TGF-?1 and p Smad3 protein in 4W+P144 group was decreased(P<0.05),and the difference was statistically significant,while t Smad3 had no significant change(P>0.05),but there was no significant difference.The more expression of TGF-? 1 protein in the hippocampus of OSAS rats,the longer it takes to find the hidden platform and the less number of times to cross the platform,ability of spatial learning and memory were worse,the positive correlation between escape latency and the expression of TGF-? 1 protein(P<0.05),and the negative correlation between the number of times to cross the platform and the expression of TGF-? 1 protein(P<0.05).Conclusion: TGF-? 1/Smad3 signal pathway is activated in cognitive impairment of OSAS rats,both TGF-?1 and p Smad3 expression are up-regulated.The spatial learning and memory ability of OSAS cognitive impairment rats were improved to some extent after specific inhibition of TGF-? 1. |
PDF Full Text Request