CAJ | 학술논문

目的研究小鼠创伤性脑损伤(traumatic brain injury,TBI)后急性期、亚急性期及慢性期tau蛋白磷酸化水平动态变化规律. 方法采用可控皮质打击方法建立小鼠中度TBI模型,无特定病原体(specific pathogen free,SPF)级C57BL/6雄性小鼠40只按随机数字表法分为创伤组、假手术组,创伤组又分为3个亚组:24h、7d及1个月组,每组10只.采用免疫组化方法检测伤后24 h、7d、1个月脑组织tau蛋白磷酸化水平变化、胶质细胞增生程度、神经元丢失及淀粉样肽前体蛋白(amyloid precursor protein,APP)标记的轴突损伤. 结果创伤24 h、7d、1个月组对侧海马齿状回区tau蛋白Ser404位点磷酸化水平分别为4 451.021±471.731,5 339.826±794.071,1 906.036±369.808,均较假手术组368.630±231.038明显升高(t=23.316,18.033,9.979,P＜0.01).而其余Thr205、Ser262位点磷酸化水平未见明显改变.胶质纤维酸性蛋白(glial fibrous acid protein,GFAP)免疫组化染色结果显示,创伤24 h、7d组吸光度(A)值分别为30 495.233±6 174.094,86 427.920±11 896.771,均显著高于假手术组6 825.653±3 451.641(t=9.573,9.573,P＜0.01),而创伤1个月组9 511.471±5 431.077与假手术组比较差异无统计学意义(t=1.181,P＞0.05).APP免疫组化结果显示,假手术组、创伤24h、7d及1个月组A值分别为459.061±368.608,1 802.695 2491.938,2 762.852±636.524,2 333.118±511.731,创伤组均高于假手术组(t=5.684,7.960,7.697,P＜0.01).各时相点NeuN标记神经元计数结果显示,对侧齿状回区神经元在创伤24 h组与假手术组[(290.056±39.162)∶(314.019±42.397)]差异无统计学意义(t=-1.017,P＞0.05),创伤7d、1个月组分别为250.509±17.592,242.717±17.045,均少于假手术组(t=-3.112,-3.506,P＜0.01). 结论 TBI后tau蛋白Ser404位点磷酸化水平长期升高可能与TBI后慢性期认知功能障碍有关.
목적 연구소서창상성뇌손상(traumatic brain injury,TBI)후급성기、아급성기급만성기tau단백린산화수평동태변화규률. 방법 채용가공피질타격방법건립소서중도TBI모형,무특정병원체(specific pathogen free,SPF)급C57BL/6웅성소서40지안수궤수자표법분위창상조、가수술조,창상조우분위3개아조:24h、7d급1개월조,매조10지.채용면역조화방법검측상후24 h、7d、1개월뇌조직tau단백린산화수평변화、효질세포증생정도、신경원주실급정분양태전체단백(amyloid precursor protein,APP)표기적축돌손상. 결과 창상24 h、7d、1개월조대측해마치상회구tau단백Ser404위점린산화수평분별위4 451.021±471.731,5 339.826±794.071,1 906.036±369.808,균교가수술조368.630±231.038명현승고(t=23.316,18.033,9.979,P＜0.01).이기여Thr205、Ser262위점린산화수평미견명현개변.효질섬유산성단백(glial fibrous acid protein,GFAP)면역조화염색결과현시,창상24 h、7d조흡광도(A)치분별위30 495.233±6 174.094,86 427.920±11 896.771,균현저고우가수술조6 825.653±3 451.641(t=9.573,9.573,P＜0.01),이창상1개월조9 511.471±5 431.077여가수술조비교차이무통계학의의(t=1.181,P＞0.05).APP면역조화결과현시,가수술조、창상24h、7d급1개월조A치분별위459.061±368.608,1 802.695 2491.938,2 762.852±636.524,2 333.118±511.731,창상조균고우가수술조(t=5.684,7.960,7.697,P＜0.01).각시상점NeuN표기신경원계수결과현시,대측치상회구신경원재창상24 h조여가수술조[(290.056±39.162)∶(314.019±42.397)]차이무통계학의의(t=-1.017,P＞0.05),창상7d、1개월조분별위250.509±17.592,242.717±17.045,균소우가수술조(t=-3.112,-3.506,P＜0.01). 결론 TBI후tau단백Ser404위점린산화수평장기승고가능여TBI후만성기인지공능장애유관.
Objective To investigate the dynamic changes in phosphorylation levels of tau proteins in the acute,sub-acute and chronic stages after traumatic brain injury (TBI) in mice.Methods Mouse models with moderate TBI were developed using the controlled cortical impactor.Forty specific pathogen free (SPF) male C57BL/6 mice were allocated to TBI group and sham operation group according to the random number table.TBI group was subdivided at 24 hours,7 days,and 1 month.There were 10 mice per group.Levels of tau protein phosphorylation in the brain,gliosis,neuronal loss,and amyloid precursor protein (APP)-labeled axonal injury were detected by immunohistochemistry at 24 hours,7 days,and 1 month after TBI.Results Levels of tau protein phosphorylation in contralateral dentate gyrus at Ser404 site were 4 451.021 ±471.731,5 339.826 ± 794.071,and 1 906.036 ± 369.808 at 24 hours,7 days,and 1 month posttrauma,far higher than 368.630 ±231.038 in sham operation group (t =23.316,18.033,9.979 respectively,P ＜0.01).Whereas,there were no significant differences of tau protein phosphorylation at Ser262 and Thr205 between TBI and sham operation groups at all time points.Immunohistochemical staining for glial fibrous acid protein (GFAP) showed the absorbance value in TBI group was 30 495.233 ± 6 174.094 and 86 427.920 ± 11 896.771 at 24 hours and 7 days,far higher than 6 825.653-± 3 451.641 in sham operation group (t =9.573,9.573 respectively,P ＜ 0.01).Besides,the absorbance value in TBI group was 9 511.471 ± 5 431.077 at 1 month,with no statistical difference in contrast with sham operation group (t =1.181,P ＞ 0.05).Immunohistochemical staining for APP indicated the absorbance value in TBI group was 1 802.695 ± 491.938,2 762.852 ± 636.524,and 2 333.118 ± 511.731 at 24 hours,7 days,and 1 month,higher than 459.061-± 368.608 in sham operation group (t =5.684,7.960,7.697 respectively,P ＜ 0.01).Number of NeuN-labeled neurons in contralateral dentate g3rus revealed no statistical difference between TBI and sham operation groups at 24 hours [(290.056 ±39.162) vs(314.019 ±42.397),t =-1.017,P ＞0.05],but at 7 days and 1 month fewer neurons (250.509 ± 17.592,242.717 ± 17.045) were detected in TBI group than in sham operation group (t =-3.112,-3.506,P ＜ 0.01).Conclusion Persistance hyperphosphorylation of tau protein at Ser404 site may contribute to the cognitive dysfunction in the chronic stage after TBI.