Objective To investigate the effect and mechanism of phosphorylated protein kinase R-like ER kinase(p-PERK) and C/EBP homologous protein(CHOP) after hypoxic-ischemic brain damage ( HIBD) . Methods Neonatal 7-day-old Sprague Dawley rats were divided into sham-operation control group and HIBD group( n=30 per group) . Each group was divided into 0 h,6 h and 24 h subgroup after operation ( n=10 per group) . The ratio of apoptosis of brain cell was measured by flow cytometer and the expression of p-PERK and CHOP were detected by Western blot. Results (1)Apoptosis cell appeared at 6 h in HIBD group,the ratio of cell apoptosis was(2. 17 ± 0. 19)%. The apoptosis cell obvious increased at 24 h,the ratio of cell apoptosis was(13. 42 ± 0. 83)%. There was a significant increase in the ratio of apoptosis after HIBD 6 h and 24 h, as compared with sham-operation control group [ ( 0. 57 ± 0. 06 )%( P <0. 01 ) ] . ( 2 ) The expression of both p-PERK and CHOP was very low in sham-operation control group. In the HIBD group,the expression of both p-PERK and CHOP began to increase at 6 h and increased furthermore at HIBD 24 h. The differences in the expression levels of p-PERK and CHOP in HIBD group among different time points were significant( P<0. 01 ) . ( 3 ) The expression of p-PERK positively correlated with the expression of CHOP (r=0. 997,P< 0. 05). Conclusion With the emerging of apoptosis after HIBD,the expression of both p-PERK and CHOP increases. The imbalance in the expression of PERK induces the apoptosis of brain cells in the HIBD of neonatal rats by regulation of CHOP expression.

Objective The discovery of microRNA (miRNA) in maternal serum has opened up new possibilities for non-invasive prenatal diagnosis.However,our understanding of these pregnancy-related miRNA in the serum of pregnant women with fetuses with neural tube defects (NTDs) is still limited.This article is to study the dysregulated expression of microRNA-423 (miR-423) in the serum of pregnant women with neural tube defect(NTD) fetuses and its potential role as a biomarker for non-invasive prenatal diagnosis of fetal NTD.Methods Thirty-three pregnant women whose fetuses were diagnosed as neural tube defects by ultrasound (22 cases of spina bifida and 11 cases of anencephaly)and 33 normal pregnant women were selected.Peripheral venous blood of each pregnant woman was obtained early in the morning,the serum was purified from blood by centrifugation,then total RNA was isolated from serum and the miR-423 levels were detected by real-time RT-PCR.The ROC curve was used for assessing the diagnostic accuracy of miR-423 for fetal NTD.Results We revealed miR-423 with signifcant down-regulation in expression in serum of pregnant women with NTD fetuses (0.96 ±0.14) compared as women with normal pregnancies(2.28 ±0.43) (P ＜0.05).We performed ROC analysis of data from the 33 case-control pairs.The expression of miR-423 could distinguish NTD cases from normal controls,with an AUC of 0.711 (95 ％ CI:0.566 ～ 0.856) (P ＜ 0.05).Moreover,the expression of miR423 decreased only in serum of pregnant women with anencephaly fetuses(0.58 ±0.08)by the analysis in different forms of NTD.Conclusion miR-423 is deregulated in the serum of pregnant women with NTD fetuses and highlight the clinical potential of miR-423 as biomarker for diagnosis and prognostication of fetal NTD.