侧脑室注射miR-219激动剂对脂多糖所致新生大鼠少突胶质细胞成熟障碍的影响  

Intracerebroventricular injection of miR-219 agomir improves lipopolysaccharide-induced impairment of oligodendrocyte maturation in newborn rats

作　　者：廖芸茜 张攀[1] 谭宇亭[1] 刘兰[1] 杜敏[1] 徐颖[1] LIAO Yunxi;ZHANG Pan;TAN Yuting;LIU Lan;DU Min;XU Ying(Department of Anesthesiology, Key Laboratory of Child Development and Disorders of Ministry of Education, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Pediatrics, Children＇ s Hospital of Chongqing Medical University, Chongqing, 400014, China)

机构地区：[1]重庆医科大学附属儿童医院麻醉科,儿童发育疾病研究教育部重点实验室,儿童发育重大疾病国家国际科技合作基地,儿科学重庆市重点实验室,重庆400014

出　　处：《第三军医大学学报》2018年第8期693-698,共6页Journal of Third Military Medical University

基　　金：重庆市基础与前沿研究计划项目(CSTC2016jcyjA0334)

摘　　要：目的探讨侧脑室注射miR-219激动剂对脂多糖(lipopolysaccharide,LPS)所致新生大鼠少突胶质细胞成熟障碍的影响。方法将出生2 d的Sprague-Dawley(SD)大鼠60只随机分为4组,每组15只。对照组:腹腔注射等体积生理盐水,24 h后侧脑室注射2μL miRNA阴性对照。脂多糖组(LPS组):腹腔注射0.25 mg/kg LPS,24 h后侧脑室注射2μL miRNA阴性对照;miR-219激动剂组(miR-219组):腹腔注射等体积的生理盐水,24 h后侧脑室注射2μL miR-219激动剂;LPS加miR-219激动剂组(LPS+miR-219组):腹腔注射0.25 mg/kg LPS,24 h后侧脑室注射2μL miR-219激动剂。实时荧光定量PCR(RT-q PCR)检测脑组织中miR-219和髓鞘碱性蛋白(myelin basic protein,MBP)mRNA的表达,苏木精伊红(hematoxylin-eosin,HE)染色观察脑白质形态学改变,免疫组化观察成熟少突胶质细胞(oligodendrocyte,OL)的表达,免疫印迹法(Western blotting)检测脑组织内MBP和Sox6蛋白的表达。结果侧脑室注射miR-219激动剂后,miR-219组miR-219的表达增高(P<0.05);腹腔注射LPS后,LPS组脑白质区组织结构疏松,细胞核固缩,与对照组比较,成熟少突胶质细胞标志物MBP的表达显著下降,少突胶质细胞分化抑制因子Sox6表达明显增多(P<0.05);相较于LPS组,LPS+miR-219组MBP表达增多,Sox6表达显著降低(P<0.05),且与对照组无明显差异(P>0.05)。结论侧脑室注射miR-219激动剂可以改善LPS致新生鼠少突胶质细胞成熟障碍。Objective To investigate the effect of intracerebroventricular injection of miR-219 agomir on lipopolysaccharide（ LPS）-induced white matter injury in newborn rats. Methods Sixty 2-day-old Sprague-Dawley rats were randomly divided into 4 groups and subjected to intraperitoneal injections of normal saline or LPS（ 0. 25 mg/kg）,followed 24 h later by intracerebroventricular injection of the negative control miR agomir or miR-219 agomir. RT-q PCR was used to detect the expression of miR-219 and myelin basic protein（ MBP） mRNA in brain tissues. HE staining was used to observe the morphological changes of the white matter. Mature oligodendrocytes were identified using immunohistochemistry,and the expressions of MBP and Sox6 proteins in the brain tissue were detected using Western blotting. Results Intracerebroventricular injection of miR-219 agomir resulted in significantly increased expressions of miR-219 in the brain tissue of the rats（ P〈0. 05）. Intraperitoneal injection of LPS caused obvious white matter injuries highlighted by loosened tissue structure and nuclear condensation,and induced a significant decrease in the expression of MBP（ the marker of mature oligodendrocytes） along with a significant decrease in the expression of oligodendrocyte differentiation inhibitory factor Sox6（ P〈0. 05）. Compared with those in LPS ＋ control miR agomir group,the rats in LPS ＋ miR-219 group showed significantly increased MBP expression and decreased Sox6 expression in the brain tissue（ P〈0. 05）,and no significant differences were found in MBP or Sox6 expressions between the saline ＋ control miR agomir group and LPS ＋ miR-219 group（ P〉0. 05）. Conclusion Intracerebroventricular injection of miR-219 can improve LPS-induced impairment of oligodendrocyte maturation in newborn rats.

关 键 词：脑白质损伤 少突胶质细胞 miR-219 

分 类 号：R394.2[医药卫生—医学遗传学] R742[医药卫生—基础医学]