Autophagy in hippocampal nerve cells from rats with sepsis-associated encephalopathy / 中南大学学报(医学版)

OBJECTIVE@#To show evidence of the autophagy in hippocampal nerve cells from rats with sepsis-associated encephalopathy (SAE) in vivo and to investigate the expression of microtubule-associated protein 1 light chain 3 (LC3). 
@*METHODS@#A rat model of sepsis was established by the cecal ligation and puncture (CLP). A total of 60 male Wistar rats (30 days old) were randomly divided into a sham group (n=10) and a CLP group (n=50). At 12 hours after CLP, the electroencephalogram (EEG) and somatosensory evoked potential (SEP) changes in rats were monitored and the neurobehavioral score was measured. According to the occurrence of SAE, the CLP group was further divided into an SAE(+) group and an SAE(-) group. Histopathological changes in hippocampus were observed by hematoxylin-eosin staining. An electron microscope was used to observe autophagosome formation and lysosome activation in the hippocampal nerve cells. Expressions of LC3-I and LC3-II protein were measured by Western blot. 
@*RESULTS@#Five of 50 rats in CLP group died in 12 hours after CLP. According to the low neurobehavioral score and abnormal EEG and SEP, 16 rats were diagnosed as SAE. The incidence of SAE was 35.56% (16/45). Compared with the sham group or the SAE(-) group, the frequency of α wave in SAE(+) group was significantly decreased at 12 hours after CLP, the δ wave increased, the P1 amplitude decreased, and the latency of SEP waves (P1 and N1) was prolonged (P<0.05). The morphology of hippocampal nerve cells was obvious in a status of edema. Pyramidal cells decreased significantly, even dissolved, and cell arrangement was in disorder in the SAE(+) group. But these cells were normal in the sham group and the SAE(-) group. The structure of hippocampal nerve cells was disordered, and the autophagy, granular matrix and square or rectangular crystals were found in the SAE(+) group. However, there was no autophagy both in the sham group and the SAE(-) group. LC3-II/LC3-I ratio in the hippocampal nerve cells was increased significantly at 12 hours after CLP in the SAE(+) group when compared with that in the sham or the SAE(-) group (P<0.05). 
@*CONCLUSION@#There is autophagy in hippocampal nerve cells from rats with SAE and the LC3-II/LC3-I ratio is increased significantly.

Expression of apoptotic protease cysteinyl aspartate specific proteinase-3 in cortex of rats with sepsis / 中华实用儿科临床杂志

Objective To investigate the expression of apoptotic protease cysteinyl aspartate specific proteinase (caspase-3) in cortex neurons of rats with sepsis.Methods Models of rats with sepsis were established by the cecal ligation and puncture (CLP).Totally 70 cases of 30-day-old male Wistar rats were randomly divided into CLP group (n =50) and control group (n =20).In CLP group,CLP was performed in the rats.Neurobehavioral score was measured in 5 rats at 6,12,24 and 48 h after CLP surgery,respectively.Then,they were killed and their brains were removed.The immunohistochemical staining and Western blot were used to detect the apoptotic protein caspase-3 expression in cortex of rats.Control group did not undergo CLP,and the other treatment was the same as CLP group.Results Neurobehavioral scores at 12,24 and 48 h after CLP surgery were significantly lower than that in the control group(t =3.651,3.773,7.155,all P ＜ 0.05),and the scores were gradually decreased,overall situation of rats was getting worse along with the time.Caspase-3 protein expressed only in trace amounts in rat cerebral cortex in the control group by immunofluorescence analysis,however,its expression was significantly increased at 12 h after CLP surgery.Western blot test showed that caspase-3 protein expression in rat cerebral cortex at 6,12 and 24 h after CLP surgery was significantly higher than those in control group (all P ＜ 0.05).Its expression began to increase at 6 h after CLP surgery,and reached the peak at 12 h,then decreased at 48 h.Conclusion The neurobehavioral scores decreases and the expression of apeptosis protease caspase-3 increases in cortex of rats with sepsis brain injury.