Mitophagy And Cognitive Impairment In Rats With Obstructive Sleep Apnea Syndrome

Objective:To investigate the correlation between mitophagy and cognitive impairment in rats with obstructive sleep apnea syndrome(OSAS).Methods:Thirty-six 3-month-old male SD rats were randomly divided into control group and experimental group(18 rats in each group).After OS AS model was established in the experimental group,they were divided into the 2-week experiment group,the 4-week experiment group,and the 6-week experiment group(6 rats each in each group)according to the length of continued feeding(2 weeks,4 weeks,and 6 weeks).The control group was fed under normal conditions and also divided into the 2-week control group,the 4-week control group,and the 6-week control group(6 rats in each group)according to the length of continued feeding(2 weeks,4 weeks,and 6 weeks).The Morris water maze test was used to detect rat cognition.HE and TUNEL was used to detect the changes in nerve cells in the CA1 region of the hippocampus.Western blot was used to detect the expression of LC3(LC3?/LC3?),p62,PINK1 and Parkin protein.And transmission electron microscopy was used to observe mitochondria.Results:1.OSAS model:The rats in the experimental group were lazy,poor alertness,eating less,irregular breathing rhythm occasionally after modeling.The oxyhemoglobin saturation of rats in the experimental group after model establishment was lower than that before model establishment,and the difference was statistically significant(p<0.05).The OSAS model was made successfully.2.Morris water maze test:(1)In the navigation experiment,the average latency of each group was gradually shortened after repeated training everyday.And on the same day of training,the average time of escape latency for rats in the experimental group was longer than that in the control group at the same point,and the rats in the experimental 4-week group was longer than that in the experimental 2-week group,and the rats in the experimental 6-week group was longer than that in the experimental 4-week group,the differences were statistically significant(p<0.05).It shows that the longer the feeding time,the longer the average time of escape latency.(2)In the space exploration test:the average number of passes for rats in the experimental group was less than that in the control group at the same point,and the rats in the experimental 4-week group was less than that in the experimental 2-week group,and the rats in the experimental 6-week group was less than that in the experimental 4-week group,the differences were statistically significant(p<0.05).The longer the feeding time,the less the average number of passes.3.HE staining showed that compared with the control group at the same point,the hippocampal neurons of rats in the experimental group showed disorder,broken and condensed nucleus,and so on.4.TUNEL staining showed that there were more apoptotic cells in the CA1 region of the hippocampus in the experimental group than in the control group at the same point,and the rats in the experimental 4-week group was more than that in the experimental 2-week group,and the rats in the experimental 6-week group was more than that in the experimental 4-week group,the differences were statistically significant(p<0.05).And the longer the feeding time,the more apoptotic cells.5.Western Blot results:The expression of LC3(LC3?/LC3?),PINK1 and Parkin protein in the CA1 region of the hippocampus in the experimental group was higher than that in the control group at the same point,and the expression of p62 was lower than that in the control group at the same point.And the rats in the experimental 4-week group was higher than that in the experimental 2-week group,and the rats in the experimental 6-week group was higher than that in the experimental 4-week group,the differences were statistically significant(p<0.05).With the extension of feeding time,the expression of LC3(LC3?/LC3?),PINK1 and Parkin protein increased,and the expression of p62 showed a trend of decreasing,and the differences were statistically significant(p<0.05).6.Transmission electron microscopy showed that the number of mitophagosomes in the experimental group was more than that in the control group at the same point,and the rats in the experimental 4-week group was more than that in the experimental 2-week group,and the rats in the experimental 6-week group was more than that in the experimental 4-week group,the differences were statistically significant(p<0.05).And the longer the feeding time,the more the number of mitophagosomes.Conclusion:1.Mitophagy can occur in hippocampal nerve cells of rats with obstructive sleep apnea syndrome.2.The degree of mitophagy in hippocampal neurons of rats with obstructive sleep apnea increased with the extension of feeding time.3.Rats with obstructive sleep apnea have cognitive impairment and are associated with apoptosis of hippocampal neurons.4.The cognitive impairment of rats with obstructive sleep apnea increased with the extension of feeding time.5.The degree of mitophagy in hippocampal neurons of rats with obstructive sleep apnea was directly proportional to the degree of cognitive impairment.6.The hippocampal neurons of rats with obstructive sleep apnea may have excessive mitophagy,which may aggravate the cognitive impairment of rats with obstructive sleep apnea.