Department of Ophthalmology, China Medical University the Fourth People's Hospital of Shenyang, No.20 Huang He Street, Huang Gu District, Shenyang City, 110031, Liaoning Province, China.
BMC Neurosci. 2022 Nov 10;23(1):63. doi: 10.1186/s12868-022-00747-3.
Retinal ganglion cells (RGCs) are important retinal neurons that connect visual receptors to the brain, and lysine-specific demethylase 1 (LSD1) is implicated in the development of RGCs. This study expounded the mechanism of LSD1 in oxygen-glucose deprivation/reoxygenation (OGD/R)-induced pyroptosis of RGCs.
Mouse RGCs underwent OGD/R exposure, and then RGC viability was examined using the cell counting kit-8 method. The mRNA levels of Caspase 1, the protein levels of NOD-like receptor family pyrin domain-containing 3 (NLRP3), N-terminal fragment of gasdermin D (GSDMD-N), and cleaved-Caspase1, and the concentrations of interleukin (IL)-1β and IL-18 were respectively examined. Subsequently, LSD1 expression was intervened to explore the underlying effect of LSD1 on OGD/R-induced pyroptosis of RGCs. Afterwards, the enrichments of LSD1 and histone H3 lysine 4 methylation (H3K4me) 1/2 on the microRNA (miR)-21-5p promoter were determined using chromatin-immunoprecipitation assay. And the binding interaction between miR-21-5p and NLRP12 was detected using dual-luciferase and RNA pull-down assays. Finally, the effects of miR-21-5p/NLRP12 on LSD1-mediated pyroptosis of RGCs were verified through functional rescue experiments.
OGD/R treatment increased pyroptosis of RGCs and LSD1 expression. Silencing LSD1 declined levels of Caspase 1 mRNA, NLRP3, GSDMD-N, cleaved-Caspase1, IL-1β, and IL-18 and limited pyroptosis of OGD/R-treated RGCs. Mechanically, LSD1 suppressed miR-21-5p expression via demethylation of H3K4me2 on the miR-21-5p promoter to hamper the binding of miR-21-5p to NLRP12, and thereby increased NLRP12 expression. Silencing miR-21-5p or overexpressing NLRP12 facilitated OGD/R-induced pyroptosis of RGCs.
LSD1-mediated demethylation of H3K4me2 decreased miR-21-5p expression to increase NLRP12 expression, promoting pyroptosis of OGD/R-treated RGCs.
视网膜神经节细胞（RGCs）是连接视觉感受器和大脑的重要视网膜神经元，赖氨酸特异性去甲基酶 1（LSD1）参与了 RGCs 的发育。本研究阐述了 LSD1 在氧葡萄糖剥夺/再复氧（OGD/R）诱导的 RGCs 细胞焦亡中的作用机制。
用细胞计数试剂盒-8 法检测小鼠 RGCs 经历 OGD/R 暴露后的细胞活力。检测 Caspase 1mRNA 水平、NOD 样受体家族含 pyrin 结构域蛋白 3（NLRP3）、gasdermin D（GSDMD-N）的 N 端片段和裂解 Caspase1 的蛋白水平，以及白细胞介素（IL）-1β和 IL-18 的浓度。随后，通过 LSD1 表达干预，探讨 LSD1 对 OGD/R 诱导的 RGCs 细胞焦亡的潜在影响。随后，用染色质免疫沉淀试验测定 LSD1 和组蛋白 H3 赖氨酸 4 甲基化（H3K4me）1/2 在 miR-21-5p 启动子上的富集情况。用双荧光素酶和 RNA 下拉实验检测 miR-21-5p 与 NLRP12 之间的结合相互作用。最后，通过功能拯救实验验证 miR-21-5p/NLRP12 对 LSD1 介导的 RGCs 细胞焦亡的影响。
OGD/R 处理增加了 RGCs 的细胞焦亡和 LSD1 的表达。沉默 LSD1 降低了 Caspase 1mRNA、NLRP3、GSDMD-N、裂解 Caspase1、IL-1β和 IL-18 的水平，并限制了 OGD/R 处理的 RGCs 的细胞焦亡。机制上，LSD1 通过去甲基化 miR-21-5p 启动子上的 H3K4me2 抑制 miR-21-5p 的表达，从而阻止 miR-21-5p 与 NLRP12 结合，从而增加 NLRP12 的表达。沉默 miR-21-5p 或过表达 NLRP12 促进了 OGD/R 诱导的 RGCs 细胞焦亡。
LSD1 介导的 H3K4me2 去甲基化降低了 miR-21-5p 的表达，增加了 NLRP12 的表达，促进了 OGD/R 处理的 RGCs 的细胞焦亡。
