摘要
目的探讨褪黑素对脂多糖和缺血缺氧诱导的新生大鼠脑白质损伤的保护作用及机制。方法选择3日龄新生Sprague-Dawley(SD)大鼠72只,随机分为假手术组、模型组和褪黑素组各24只。假手术组仅游离右侧颈动脉、不进行结扎,不予低氧处理;模型组和褪黑素组采用脂多糖预处理+缺血缺氧法制作脑白质损伤动物模型。褪黑素组在注射脂多糖前1 h和之后每天腹腔注射褪黑素15 mg/kg,假手术组和模型组在相同时间点给予等体积含1%无水乙醇的生理盐水腹腔注射。实验第7天处死大鼠,取脑室周围白质,采用HE染色和TUNEL染色观察脑白质损伤和凋亡情况,IBA1免疫荧光染色观察小胶质细胞分布和形态,活性氧(reactive oxygen species,ROS)试剂盒检测ROS水平,实时荧光定量聚合酶链反应检测核苷酸结合寡聚化结构域样受体3(nucleotide-binding domain-like receptor protein 3,NLRP3)炎症小体、白细胞介素(interleukin,IL)-1β、IL-18、PTEN诱导假定激酶1、帕金森病蛋白的表达情况。结果与假手术组相比,模型组大鼠脑白质结构破坏、细胞变性坏死、细胞凋亡数量增加,脑白质NLRP3炎症小体及下游的IL-1β、IL-18等炎症因子表达增加;与模型组相比,褪黑素组脑白质损伤、细胞凋亡、小胶质细胞浸润情况减轻,炎症因子表达减少,脑白质线粒体自噬标志物PTEN诱导假定激酶1、帕金森病蛋白表达增加,ROS产生减少。结论褪黑素通过增强线粒体自噬减少ROS的产生,从而抑制NLRP3炎症小体过度激活,缓解内毒素和缺血缺氧导致的新生大鼠脑白质损伤。
Objective To study the protective effects and mechanisms of melatonin(MTn)on lipopolysaccharide(LPS)and hypoxic-ischemic(HI)induced white matter damage(WMD)in neonatal rats.Methods Seventy-two 3-day-old newborn Sprague-Dawley(SD)rats were randomly assigned into sham operation group(the sham group),model group(the HI group)and MTn intervention group(the HI+MTn group)(n=24 for each group).For the sham group,only dissection of the right common carotid artery was performed without ligation.Animal models of WMD were established using LPS pretreatment and HI method in both the HI group and HI+MTn group.The HI+MTn group received MTn intraperitoneal injection(15 mg/kg,1 h before LPS injection and then once daily).The HI group and the sham group received equal volume of normal saline containing 1%ethanol intraperitoneal injection.The rats were sacrificed on d7 of experiment and periventricular white matter(PVWM)was collected for hematoxylin-eosin(HE)and TUNEL staining to determine WMD and apoptosis.The distribution and morphology of microglial cells in the PVWM were studied using IBA1 immunofluorescence staining.Reactive oxygen species(ROS)kit was used to detect ROS.The expression of nucleotide-binding domain-like receptor protein 3(NLRP3)inflammasomes,interleukin(IL)-1β,IL-18 and mitochondrial autophagy markers(pink1 and parkin)were determined using real-time quantitative PCR.Results Compared with the sham group,the HI group showed WMD,cell degeneration and necrosis,increased cell apoptosis and increased expressions of NLRP3 inflammasomes and downstream inflammatory factors(IL-1βand IL-18)in PVWM.Compared with the HI group,the HI+MTn group showed reduced WMD,cell apoptosis,microglia infiltration and inflammatory factors expression.MTn increased pink1 and parkin expression and reduced ROS production in PVWM.Conclusions MTn reduces ROS production by enhancing mitochondrial autophagy and inhibits NLRP3 inflammasomes hyperactivation to alleviate endotoxin-and HI-induced WMD in neonatal rats.
作者
刘燕
高俊杰
孙梦雅
李婷
秦苗
Liu Yan;Gao Junjie;Sun Mengya;Li Ting;Qin Miao(Department of Neonatology,Affiliated Hospital of Qingdao University,Qingdao 266003,China;Department of Health Care,Qingdao Municipal Hospital,Qingdao 266071,China)
出处
《中华新生儿科杂志（中英文）》
CAS
CSCD
2023年第6期359-364,共6页
Chinese Journal of Neonatology
基金
山东省医药卫生科技发展计划项目(2016WS0267)。
