CAJ | 학술논문

目的探讨p38丝裂原活化蛋白激酶(p38 MAPK)在全脑缺血再灌注损伤大鼠海马神经元DNA修复中的作用.方法清洁级雄性SD大鼠108只,采用四血管阻断法建立大鼠全脑缺血再灌注模型,随机分为3组(n=36):假手术组(S组)仅暴露双侧颈总动脉和椎动脉;缺血再灌注组(IR组)侧脑室注射1%DMSO溶液5μl,30 min后行全脑缺血再灌注;p38 MAPK抑制剂SB203580干预组(SB组)侧脑室注射SB203580溶液5 μl(溶于1%DMSO溶液),30 min后行全脑缺血再灌注.分别于再灌注2、6、12、24、48和72 h时各组处死6只大鼠,提取海马组织观察神经元病理学结果,计算神经元凋亡指数(AI),测定磷酸化的p38 MAPK蛋白及Ku70蛋白表达水平.结果与S组比较,IR组和SB组各时点AI升高,p-p38 MAPK蛋白表达上调,p-Ku70蛋白表达下调(P(0.05或0.01),病理损伤明显;与IR组比较,SB组各时点AI降低,p-p38 MAPK蛋白表达下调,p-Ku70蛋白表达上调(P<0.01),病理损伤程度减轻.结论 p38 MAPK可能通过下调DNA修复酶Ku70蛋白的表达,使海马神经元DNA修复功能受损,导致神经元凋亡,参与全脑缺血再灌注损伤.
목적 탐토p38사렬원활화단백격매(p38 MAPK)재전뇌결혈재관주손상대서해마신경원DNA수복중적작용.방법 청길급웅성SD대서108지,채용사혈관조단법건립대서전뇌결혈재관주모형,수궤분위3조(n=36):가수술조(S조)부폭로쌍측경총동맥화추동맥;결혈재관주조(IR조)측뇌실주사1%DMSO용액5μl,30 min후행전뇌결혈재관주;p38 MAPK억제제SB203580간예조(SB조)측뇌실주사SB203580용액5 μl(용우1%DMSO용액),30 min후행전뇌결혈재관주.분별우재관주2、6、12、24、48화72 h시각조처사6지대서,제취해마조직관찰신경원병이학결과,계산신경원조망지수(AI),측정린산화적p38 MAPK단백급Ku70단백표체수평.결과 여S조비교,IR조화SB조각시점AI승고,p-p38 MAPK단백표체상조,p-Ku70단백표체하조(P(0.05혹0.01),병리손상명현;여IR조비교,SB조각시점AI강저,p-p38 MAPK단백표체하조,p-Ku70단백표체상조(P<0.01),병리손상정도감경.결론 p38 MAPK가능통과하조DNA수복매Ku70단백적표체,사해마신경원DNA수복공능수손,도치신경원조망,삼여전뇌결혈재관주손상.
Objective To investigate the role of p38 mitogen-activated protein kinase (MAPK) in the DNA repair in hippocampus in a rat model of global cerebral ischemia-reperfnsion (I/R). Methods One hundred and eight male 55-65 day old SD rats weighing 280-320 g were divided into 3 groups ( n = 36 each) : group Ⅰ sham operation (S), group Ⅱ I/R and group Ⅲ SB203580 + I/R (SB). The animals were anesthetized with intraperitoneal 1% pentobarbital 40 mg/kg. Global cerebral ischemia-reperfnsiun was produced by 4 vessel method. Bilateral vertebral arteries were electrically cauterized and bilateral common carotid arteries were clamped for 5 min with atranmatic mini-clamp. In group Ⅲ 5 μl 0.1 nmol/μl p38 MAPK inhibitor, SB203580 (in 1% DMSO) was injected into the lateral ventricle of the brain 30 min before cerebral global I/R. Six animals were killed at 2, 6, 12, 24, 48 and 72 h of reperfusion respectively. The hippocampus was isolated for microscopic examination. Apeptosis index was calculated and p-p38 MAPK and DNA repair protein Ku70 protein expression was determined. Results AI was signifieanfly higher, p-p38 MAPK protein expression was up-regulated and p-Ku70 protein expression was down-regalated and there was severe histological damage in I/R and SB groups as compared with group S. Pretreatment with SB203580 attenuated the above-mentioned I/R induced cerebral changes. Conclusion p38 MAPK damages DNA repair function by down-regulating KuT0 protein expression during global cerebral I/R and induces neuronal apoptosis.