CAJ | 학술논문

目的观察组蛋白去乙酰化酶(histone deacetylase,HDAC)抑制剂丁酸钠(sodium butyrate,NaB)对七氟醚麻醉诱发新生大鼠远期认知功能障碍的影响. 方法 24只6日龄新生雄性Sprague-Dawley (SD)大鼠按随机数字表法分为3组(每组8只):O2+生理盐水组(O2+NS组)、七氟醚麻醉+生理盐水组(Sev+NS组)及七氟醚麻醉+NaB组(Sev+NaB组).Sev+NS组和Sev+NaB组分别在出生后6d～8d时,每天接受1次2h的3％七氟醚+100％O2麻醉;O2+NS组在相应日龄吸入相同时间100％O2.出生后第9天起至行为学测试结束前分别进行生理盐水(10 ml/kg)和NaB(1.2 g/kg)腹腔注射,连续32 d.第31天行旷场实验,第34～40天行水迷宫实验.行为学测试结束后1h,取海马,Western blot检测HDAC2、脑源性神经营养因子(brain-derived neurotrophic factor,BDNF)、突触后密度蛋白95 (postsynaptic density 95,PSD95)及微管相关蛋白2(microtubuleassociated protein 2,MAP2)含量;免疫荧光检测海马分区乙酰化-组蛋白H3赖氨酸9(histone H3 lysine 9,H3K9)和乙酰化-组蛋白H4赖氨酸12(histone H4 lysine 12,H4K12)荧光强度. 结果旷场实验中,各组探索路程、运动速度及中央格停留时间比较,差异无统计学意义(P＞0.05).与O2+NS组比较,Sev+NS组在水迷宫实验第36、37天的逃避潜伏期明显延长,目标象限停留时间[O2+NS组(30.2±2.8)s,Sev+NS组(16.8±2.9)s,Sev+NaB组(28.3±3.4)s]及穿越原平台次数[O2+NS组(5.4±0.8)次,Sev+NS组(2.5±0.8)次,Sev+NaB组(5.5±0.7)次)]明显减少(P＜0.05),HDAC2含量明显增加,CA1区乙酰化-H3K9和乙酰化-H4K12荧光强度及BDNF、PSD95和MAP2含量明显降低(P＜0.05);而注射NaB后可改善以上检测指标的异常(P＜0.05).结论 HDAC抑制剂NaB可改善七氟醚麻醉所致新生大鼠远期海马依赖性空间认知功能受损,其机制可能与增加海马内组蛋白乙酰化及突触可塑性有关.
목적 관찰조단백거을선화매(histone deacetylase,HDAC)억제제정산납(sodium butyrate,NaB)대칠불미마취유발신생대서원기인지공능장애적영향. 방법 24지6일령신생웅성Sprague-Dawley (SD)대서안수궤수자표법분위3조(매조8지):O2+생리염수조(O2+NS조)、칠불미마취+생리염수조(Sev+NS조)급칠불미마취+NaB조(Sev+NaB조).Sev+NS조화Sev+NaB조분별재출생후6d～8d시,매천접수1차2h적3％칠불미+100％O2마취;O2+NS조재상응일령흡입상동시간100％O2.출생후제9천기지행위학측시결속전분별진행생리염수(10 ml/kg)화NaB(1.2 g/kg)복강주사,련속32 d.제31천행광장실험,제34～40천행수미궁실험.행위학측시결속후1h,취해마,Western blot검측HDAC2、뇌원성신경영양인자(brain-derived neurotrophic factor,BDNF)、돌촉후밀도단백95 (postsynaptic density 95,PSD95)급미관상관단백2(microtubuleassociated protein 2,MAP2)함량;면역형광검측해마분구을선화-조단백H3뢰안산9(histone H3 lysine 9,H3K9)화을선화-조단백H4뢰안산12(histone H4 lysine 12,H4K12)형광강도. 결과 광장실험중,각조탐색로정、운동속도급중앙격정류시간비교,차이무통계학의의(P＞0.05).여O2+NS조비교,Sev+NS조재수미궁실험제36、37천적도피잠복기명현연장,목표상한정류시간[O2+NS조(30.2±2.8)s,Sev+NS조(16.8±2.9)s,Sev+NaB조(28.3±3.4)s]급천월원평태차수[O2+NS조(5.4±0.8)차,Sev+NS조(2.5±0.8)차,Sev+NaB조(5.5±0.7)차)]명현감소(P＜0.05),HDAC2함량명현증가,CA1구을선화-H3K9화을선화-H4K12형광강도급BDNF、PSD95화MAP2함량명현강저(P＜0.05);이주사NaB후가개선이상검측지표적이상(P＜0.05).결론 HDAC억제제NaB가개선칠불미마취소치신생대서원기해마의뢰성공간인지공능수손,기궤제가능여증가해마내조단백을선화급돌촉가소성유관.
Objective To observe the effects of histone deacetylase (HDAC) inhibitor sodium butyrate (NaB) on sevoflurane-induced long-term cognitive dysfunction in neonatal rats.Methods Twenty-four male Sprague-Dawley (SD) rats at postnatal day 6 were randomly divided into the following three groups (n=8) in accordance with a random number table:O2+normal saline group (O2+NS group),sevoflurane anesthesia+normal saline group(Sev+NS group) and sevoflurane anesthesia+sodium butyrate group (Sev+NaB group).Animals were subjected to 3％ sevoflurane plus 100％ O2 or 100％ O2 2 h daily for 3 consecutive days,respectively.Thereafter,animals in different groups were chronically given intraperitoneal injections of NS(10 ml/kg) or NaB (1.2 g/kg)for 32 d,respectively.Open field was performed at postnatal day 31,and the Morris Water Maze test was performed at postnatal day 34-40.The hippocampus was harvested 1 h after the behavioral test to measure the content of HDAC2,brain-derived neurotrophic factor (BDNF),postsynaptic density 95 (PSD95) and microtubule associated protein (MAP2).Immunofluorescence was used to confirm the fluorescence intensity of acetyl-histone H3 lysine 9(H3K9) and acetyl-histone H4 lysine 12(H4K12) in the hippocampus subfields.Results In the open field test,there was no significant difference in the total travel distance,speed,and the time spent in the center of the arena among the three groups(P＞0.05).In the Morris Water Maze test,the escape latency at postnatal day 36-37increased significantly,the time spent in the target quadrant [O2+NS group:(30.2±2.8) s,Sev+NS group:(16.8±2.9) s,Sev+NaBgroup:(28.3±3.4) s] and times across the original platform [O2+NS group:(5.4±0.8) times,Sev+NS group:(2.5±0.8) times,Sev+NaB group:(5.5±0.7) times] reduced significantly,the content of HDAC2 increased significantly,fluorescence intensity of acetyl-H3K9 and H4K12 in hippocampal CA1 region and the content of BDNF,PSD95 as well as MAP2 decreased significantly in the Sev+NS group compared with the O2+NS group (P＜0.05).However,NaB by intraperitoneal injection could reverse the above measurement indicators to normal levels (P＜0.05).Conclusions Histone deacetylase inhibitor NaB can alleviate sevoflurane anesthesia-induced hippocampus-dependent long-term cognitive dysfunction in neonatal rats,which is associated with the up-regulation of histone acetylation and synaptic plasticity in hippocampus.