Department of Traditional Chinese Medicine, Shanghai Sixth People's Hospital, Shanghai, China.
Department of Encephalopathy, Shanghai Municipal Hospital of Traditional Chinese Medicine, Shanghai, China.
Int J Neurosci. 2023 Jul;133(7):740-753. doi: 10.1080/00207454.2021.1972999. Epub 2023 Feb 2.
To investigate the regulation and related mechanisms of MALAT1 in cerebral ischemia- reperfusion (CI/R) injury.
72 mice were divided into sham group (n=24), MCAO group (n=24), MCAO+pcDNA-NC group (n=12) and MCAO+MALAT1 group (n=12). At 12 h, 24 h and 48 h after reperfusion, 6 mice were randomly selected from the sham group and the MCAO group to detect the expression of MALAT1, miR-142-3p and SIRT1 in brain tissue. All mice were scored for neurobehavioral after 48 h of reperfusion. After the completion of the scoring, 6 mice were randomly selected from each group and brain tissue was obtained for TTC analysis. The remaining mice of each group were kept on the Morris water maze test after 3 days of feeding. TTC staining and cerebral infarct volume determination. The infarct size of each brain slice was calculated using Image J image analysis software. OGD/R model PC12 cells were prepared according to simulating CI/R injury in vitro. MALAT1 was cloned into the pcDNA3.1 to construct a MALAT1 overexpression vector with the empty vector NC as a control. Plasmid or oligonuceotides were transfected into PC12 cells. The content of TNF-α, IL-1β, IL-6, the content of reactive oxygen species (ROS), malondialdehyde (MDA) in brain tissue was detected. The activity of superoxide dismutase (SOD), catalase (CAT) activity was measured.
MALAT1 was down-regulated in a time-dependent manner in CI/R-damaged mouse cerebral cortex and OGD/R-induced PC12 cells, accompanied by an increase in the expression of miR-142-3p and a decrease in sirtuin 1 (SIRT1) expression. Overexpression of MALAT1 inhibited OGD/R-induced cell necrosis and apoptosis and promoted cell proliferation. Overexpression of MALAT1 reduced the levels of TNF-α, IL-6, IL-1β, ROS and MDA and increased the activities of SOD and CAT in OGD/R-injured PC12 cells. MALAT1 negatively regulated the expression of miR-142-3p, and SIRT1 was a target gene of miR-142-3p. The expression of SIRT1 induced by MALAT1 overexpression was obviously abolished by the introduction of miR-142-3p mimic. MALAT1 overexpression can exert its role by regulating the miR-142-3p/SIRT1 axis. Besides, overexpression of MALAT1 improved cerebral infarction, neurological impairment and cognitive dysfunction in CI/R mice.
MALAT1 mediates SIRT1 expression by acting as a ceRNA of miR-142-3p to improve CI/R injury.
Abbreviations: CAT: catalase; CI/R: cerebral ischemia-reperfusion; IL-1β: interleukin-1β; IL-6: interleukin-6; lncRNA: long-chain non-coding RNA; MALAT1: metastasis-associated lung adenocarcinoma transcript1; MCAO: middle cerebral artery occlusion; MDA: malondialdehyde; OGD/R: oxygen-glucose deprivation and reoxygenation; ROS: reactive oxygen species; SIRT1: sirtuin 1; SOD: superoxide dismutase; TNF-α: tumour necrosis factor-alpha.
探讨 MALAT1 在脑缺血再灌注（CI/R）损伤中的调节作用及相关机制。
72 只小鼠随机分为假手术组（n=24）、MCAO 组（n=24）、MCAO+pcDNA-NC 组（n=12）和 MCAO+MALAT1 组（n=12）。再灌注 12 h、24 h 和 48 h 时，每组随机选取 6 只小鼠，检测脑组织 MALAT1、miR-142-3p 和 SIRT1 的表达。再灌注 48 h 后对所有小鼠进行神经行为学评分。评分完成后，每组随机选取 6 只小鼠，取脑组织进行 TTC 分析。其余小鼠在 3 天喂养后继续进行 Morris 水迷宫测试。TTC 染色和脑梗死体积测定。用 Image J 图像分析软件计算每个脑切片的梗死面积。根据体外模拟 CI/R 损伤，制备 OGD/R 模型 PC12 细胞。将 MALAT1 克隆到 pcDNA3.1 中，构建 MALAT1 过表达载体，空载体 NC 作为对照。转染质粒或寡核苷酸至 PC12 细胞。检测脑组织中 TNF-α、IL-1β、IL-6、活性氧（ROS）、丙二醛（MDA）的含量。测定超氧化物歧化酶（SOD）、过氧化氢酶（CAT）的活性。
CI/R 损伤小鼠大脑皮质和 OGD/R 诱导的 PC12 细胞中 MALAT1 呈时间依赖性下调，同时 miR-142-3p 表达上调，SIRT1 表达下调。MALAT1 的过表达抑制了 OGD/R 诱导的细胞坏死和凋亡，促进了细胞增殖。MALAT1 的过表达降低了 OGD/R 损伤 PC12 细胞中 TNF-α、IL-6、IL-1β、ROS 和 MDA 的水平，提高了 SOD 和 CAT 的活性。MALAT1 负调控 miR-142-3p 的表达，SIRT1 是 miR-142-3p 的靶基因。miR-142-3p 模拟物的引入明显消除了 MALAT1 过表达诱导的 SIRT1 表达。MALAT1 可以通过调节 miR-142-3p/SIRT1 轴发挥作用。此外，MALAT1 的过表达改善了 CI/R 小鼠的脑梗死、神经损伤和认知功能障碍。
MALAT1 通过作为 miR-142-3p 的 ceRNA 调节 SIRT1 表达，改善 CI/R 损伤。
