miR-141-3p inhibits the activation of astrocytes and the release of inflammatory cytokines in bacterial meningitis through down-regulating HMGB1
miR-141-3p inhibits the activation of astrocytes and the release of inflammatory cytokines in bacterial meningitis through down-regulating HMGB1
复制标题
DOI：
10.1016/j.brainres.2021.147611
复制
发表时间：
2021-08-31
期刊：
影响因子：
2.9
通讯作者：
Cheng, Xiuyong
中科院分区：
文献类型：
--
作者：
Fang, Xiao;Wang, Huaili;Cheng, Xiuyong
背景：细菌性脑膜炎是一种严重的中枢神经系统感染性疾病，好发于儿童和青少年。许多研究表明microRNAs（miRNAs）参与了BM。本研究旨在探讨miR-141- 3 p通过HMGB 1对BM中星形胶质细胞活化和炎症反应的影响。方法：将肺炎链球菌（SP）注入3周龄大鼠侧脑室建立BM模型。采用Loeffler评分法评价神经功能恢复情况。苏木精-伊红（H&E）染色观察脑组织病理改变。从BM或未感染SD大鼠的脑组织中分离原代星形胶质细胞。通过酶联免疫吸附试验（ELISA）测定脑组织和星形胶质细胞培养上清中TNF-α、IL-1 β和IL-6的水平。采用双荧光素酶报告基因检测miR-141- 3 p与HMGB 1的靶向性关系。采用实时荧光定量聚合酶链反应（qRT-PCR）和蛋白质印迹法检测miR-141- 3 p、HMGB 1和星形胶质细胞标志物胶质细胞酸性蛋白（GFAP）的表达。采用甲基化特异性PCR（MSP）分析检测miR-141启动子的甲基化状态。结果：BM组大鼠的Loeffler评分明显降低。BM大鼠脑组织蛛网膜下腔增宽，可见明显的炎性细胞。在BM大鼠和SP处理的星形胶质细胞中，miR-141- 3 p表达降低。此外，我们发现miR-141- 3 p的过表达导致星形胶质细胞中HMGB 1、GFAP和炎性细胞因子（TNF-α、IL-1 β和IL-6）的下调。此外，双荧光素酶报告基因检测结果证实miR-141- 3 p直接靶向HMGB 1。miR-141- 3 p的过表达抑制星形胶质细胞中GFAP、TNF-α、IL-1 β和IL-6的水平，这通过HMGB 1的上调而消除。MSP分析结果表明，miR-141启动子在脑组织和星形胶质细胞中高度甲基化。DNMT 1参与骨髓中miR-141启动子甲基化。结论：miR-141- 3 p在SP诱导的星形胶质细胞和BM大鼠模型中通过抑制HMGB 1影响炎症反应。
Background: Bacterial meningitis (BM) is a serious infectious disease of the central nervous system that often occurs in children and adolescents. Many studies have suggested that microRNAs (miRNAs) are involved in BM. This study aimed to address the effects of miR-141-3p on astrocyte activation and inflammatory response in BM through HMGB1. Methods: The 3-week-old rats were injected with Streptococcus pneumoniae (SP) into the lateral ventricle to establish a BM model. Loeffler scoring method was used to evaluate the recovery of neurological function. Brain pathological damage was observed by hematoxylin and eosin (H&E) staining. Primary astrocytes were isolated from brain tissues of BM or non-infected SD rats. The levels of TNF-alpha, IL-1 beta, and IL-6 in brain tissues and astrocyte culture supernatant were measured by enzyme-linked immunosorbent assay (ELISA). The targeting relationship between miR-141-3p and HMGB1 was tested using dual-luciferase reporter assay. The expression of miR-141-3p, HMGB1, and the astrocytic marker glial fibrillary acidic protein (GFAP) were detected by quantitative real-time polymerase chain reaction (qRT-PCR) or western blotting. Methylation-specific PCR (MSP) analysis was performed to measure the methylation status of miR-141 promoter. Results: The results showed that lower Loeffler scores were exhibited in rats with BM. The subarachnoid space of brain tissues of BM rats was widened, and obvious inflammatory cells were observed. miR-141-3p expression was reduced in BM rats and SP-treated astrocytes. Additionally, we found that overexpression of miR-141-3p led to the downregulation of HMGB1, GFAP, and inflammatory cytokines (TNF-alpha, IL-1 beta, and IL-6) in astrocytes. Furthermore, the results of dual-luciferase reporter assay confirmed that miR-141-3p directly targeted HMGB1. Overexpression of miR-141-3p inhibited the levels of GFAP, TNF-alpha, IL-1 beta, and IL-6 in astrocytes, which was eliminated by the up-regulation of HMGB1. The results of MSP analysis indicated that miR-141 promoter was highly methylated in brain tissues and astrocytes. DNMT1 was involved in the methylation of miR-141 promoter in BM. Conclusion: The present study verified that miR-141-3p affected inflammatory response by suppressing HMGB1 in SP-induced astrocytes and BM rat model.