基于DTI分析膜联三肽对脓毒症相关性脑病大鼠海马微结构的保护作用

Diffusion tensor imaging analysis of protective effect of membrane-linked tripeptide on rats with sepsis-associated encephalopathy

目的应用磁共振扩散张量成像技术(DTI)分析膜联三肽(ANXA1sp)对脓毒症相关性脑病(SAE)大鼠海马微结构的保护作用。方法60只健康雄性SD大鼠随机分为4组(n=15):未处理健康雄性大鼠组(Normal组)、大鼠腹腔注射与LPS等量的生理盐水组(Control组)、大鼠腹腔注射4 mg/kg的LPS组(SAE组)、SAE模型大鼠腹腔注射1 mg/kg ANXA1sp组(ANXA1sp组)。LPS腹腔注射24 h后检测大鼠炎症指标IL-6及TNF-α,行为学测试观察大鼠逃避潜伏期、穿越平台次数及中央区活动时间和行DTI扫描观察大鼠海马FA及MD值。结果与Normal组比较,SAE组IL-6及TNF-α表达水平明显升高(P<0.05),ANXA1sp组较SAE组的IL-6及TNF-α显著减少(P<0.05)。与Normal组比较,SAE组大鼠逃避潜伏期延长,穿越平台次数减少(P<0.05);与SAE组比较,ANXA1sp组逃避潜伏期缩短,穿越平台次数显著上升(P<0.05)。相较于Control组,SAE组大鼠海马的FA值降低,MD值升高(P<0.05);相较于SAE组,ANXA1sp组大鼠FA值升高,MD值降低(P<0.05)。SAE大鼠的海马FA值与逃避潜伏期呈负相关,与穿越平台次数呈正相关,MD值与逃避潜伏期呈正相关,与穿越平台次数呈负相关。结论ANXA1sp可减少SAE大鼠炎性介质产生,改善海马微结构损伤和认知功能。

Objective To investigate the protective effect of membrane-linked tripeptide(ANXA1sp)on hippocampal microstructure in sepsis-associated encephalopathy(SAE)ratsvia magnetic resonance diffusion tensor imaging(DTI).Methods Sixty healthy male SD rats were randomly divided into 4 groups(n=15):untreated healthy male rats group(Normal group);rats intraperitoneally injected with normal saline equal to LPS(Control group);rats receiving intraperitoneal injection of LPS at 4mg/kg(SAE group);SAE model rats intraperitoneally injected with 1mg/kg ANXA1sp(ANXA1sp group).Inflammatory indexes,such as IL-6 and TNF-α,were detected 24 h after LPS intraperitoneal injection.The latency of escape,the number of crossing platforms and the activity time in the central region were observed by behavioral test.The FA and MD values of hippocampus were observed by DTI scan.Results The levels of IL-6 and TNF-αin the SAE group were higher than those in the Normal group,while the levels of IL-6 and TNF-αin the ANXA1sp group were lower than those in the SAE group.Compared with the Normal group,the escape latency of the SAE group was prolonged and the number of crossing platforms was reduced.The escape latency of the ANXA1sp group was reduced and the number of crossing platforms was increased.Compared with the Control group,the FA value of the hippocampus in the SAE group was decreased and the MD value was increased.Compared with the SAE group,the FA value of the ANXA1sp group was increased and the MD value was reduced.The FA value of the hippocampus in the SAE rats was negatively correlated with the escape latency and positively correlated with the number of crossing platforms.The MD value was positively correlated with the escape latency and negatively correlated with the number of crossing platforms.Conclusion ANXA1sp could reduce the production of inflammatory mediators and improve hippocampal microstructural damage and cognitive function in SAE rats.