CAJ | 학술논문

目的：研究蛋白激酶R样内质网激酶( protein kinase R-like ER kinase,PERK)的磷酸化及其下游的 C/EBP 同源蛋白( C/EBP homologous protein, CHOP )的表达在缺氧缺血性脑损伤( hypoxic-ischemic brain damage,HIBD)中的作用和机制。方法60只新生7日龄SD大鼠分为假手术组和HIBD组,每组各30只,每组又按照手术0 h,6 h和24 h分为3个亚组,每组10只。采用流式细胞仪检测脑细胞凋亡情况,并用 Western blot 方法测定脑组织中磷酸化的PERK 及 CHOP表达水平。结果(1) HIBD 6 h 出现典型的凋亡细胞峰,细胞凋亡率为(2．17±0．19)%。 HIBD 24 h 凋亡峰更为明显,细胞凋亡率达到(13．42±0．83)%,与假手术组(0．57±0．06)%相比,差异有统计学意义( P <0．01)。(2)假手术组与HIBD 0 h 大鼠脑组织中磷酸化的PERK和CHOP表达水平较低,在 HIBD 6 h后二者表达开始上升,24 h 上升更加明显,而假手术组各个时间点二者表达差异无统计学意义( P>0．05)。与假手术组比较,HIBD组各时间点二者的表达均明显上升,差异有统计学意义(P<0．01)。(3)缺氧缺血后各时间点磷酸化的PERK 的表达和 CHOP 的表达呈正相关(r=0．997,P<0．05)。结论脑缺氧缺血后,随着凋亡的出现,磷酸化的PERK 和 CHOP 表达水平升高,提示 PERK-CHOP通路的活化可能参与了新生大鼠 HIBD 神经细胞凋亡的发生。
목적：연구단백격매R양내질망격매( protein kinase R-like ER kinase,PERK)적린산화급기하유적 C/EBP 동원단백( C/EBP homologous protein, CHOP )적표체재결양결혈성뇌손상( hypoxic-ischemic brain damage,HIBD)중적작용화궤제。방법60지신생7일령SD대서분위가수술조화HIBD조,매조각30지,매조우안조수술0 h,6 h화24 h분위3개아조,매조10지。채용류식세포의검측뇌세포조망정황,병용 Western blot 방법측정뇌조직중린산화적PERK 급 CHOP표체수평。결과(1) HIBD 6 h 출현전형적조망세포봉,세포조망솔위(2．17±0．19)%。 HIBD 24 h 조망봉경위명현,세포조망솔체도(13．42±0．83)%,여가수술조(0．57±0．06)%상비,차이유통계학의의( P <0．01)。(2)가수술조여HIBD 0 h 대서뇌조직중린산화적PERK화CHOP표체수평교저,재 HIBD 6 h후이자표체개시상승,24 h 상승경가명현,이가수술조각개시간점이자표체차이무통계학의의( P>0．05)。여가수술조비교,HIBD조각시간점이자적표체균명현상승,차이유통계학의의(P<0．01)。(3)결양결혈후각시간점린산화적PERK 적표체화 CHOP 적표체정정상관(r=0．997,P<0．05)。결론뇌결양결혈후,수착조망적출현,린산화적PERK 화 CHOP 표체수평승고,제시 PERK-CHOP통로적활화가능삼여료신생대서 HIBD 신경세포조망적발생。
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.