Li Lei, Zha Hao, Miao Wei, Li Chunyan, Wang Aimei, Qin Shiyuan, Gao Shuang, Sheng Lingli, Wang Ying
Department of Neurology, The Second Affiliated Hospital of Kunming Medical University, No. 374, Dianmian Avenue, Wuhua District, Kunming, 650032, Yunnan, China.
Department of Reproductive Medicine, The Second Affiliated Hospital of Kunming Medical University, Kunming, 650032, China.
Metab Brain Dis. 2025 May 13;40(5):201. doi: 10.1007/s11011-025-01613-x.
Long noncoding RNA (lncRNA) MEG3 has been considered as a novel target for alleviating the brain tissue damage during cerebral ischemia-reperfusion injury (CIRI). Numerous studies have reported that pyroptosis is involved in the pathogenesis of CIRI. This study focused on whether MEG3 modulates CIRI via pyroptosis and its underlying mechanism. The middle cerebral artery occlusion/reperfusion (MCAO/R) mouse model and the oxygen glucose deprivation/reoxygenation (OGD/R) cell model were established. si-MEG3 and miR-145-5p inhibitor were transfected to inhibit MEG3 and miR-145-5p, respectively. As a TLR4 inhibitor, Resatorvid inhibits the TLR4 signaling pathway. TTC and TUNEL staining were used for infarction volume and cell death detection. The differential expression of MGE3, miR-145-5p, TLR4, NLRP3, Caspase-1, IL-1β, and IL-18 was determined using real-time PCR and western blot. The interaction between MEG3 and miR-145-5p, as well as between miR-145-5p and TLR4 was confirmed by the dual-luciferase reporter assay. This study confirmed that the elevated expression of MEG3 during CIRI, and it contributes to pyroptosis by regulating miR-145-5p/TLR4 axis. The knockdown of MEG3 reduced the expression of TLR4, NLRP3, Caspase-1, IL-1β, and IL-18, thereby preventing pyroptosis. Inhibition of miR-145-5p reversed the effect of MEG3 knockdown and promoted pyroptosis. Resatorvid, the inhibitor of TLR4, counteracted the effect of miR-145-5p inhibitor and suppressed pyroptosis. Our findings reveal that MEG3 promotes pyroptosis via miR-145-5p/TLR4/NLRP3 axis and aggravates CIRI, suggesting a potential therapeutic target for ischemic stroke.
长链非编码RNA（lncRNA）MEG3被认为是减轻脑缺血再灌注损伤（CIRI）期间脑组织损伤的新靶点。大量研究报道，细胞焦亡参与了CIRI的发病机制。本研究聚焦于MEG3是否通过细胞焦亡调节CIRI及其潜在机制。建立了大脑中动脉闭塞/再灌注（MCAO/R）小鼠模型和氧糖剥夺/复氧（OGD/R）细胞模型。分别转染si-MEG3和miR-145-5p抑制剂以抑制MEG3和miR-145-5p。作为一种TLR4抑制剂，瑞斯托霉素抑制TLR4信号通路。采用TTC和TUNEL染色检测梗死体积和细胞死亡情况。使用实时PCR和蛋白质免疫印迹法测定MGE3、miR-145-5p、TLR4、NLRP3、半胱天冬酶-1、白细胞介素-1β和白细胞介素-18的差异表达。通过双荧光素酶报告基因测定法证实了MEG3与miR-145-5p之间以及miR-145-5p与TLR4之间的相互作用。本研究证实，CIRI期间MEG3表达升高，且通过调节miR-145-5p/TLR4轴促进细胞焦亡。敲低MEG3可降低TLR4、NLRP3、半胱天冬酶-1、白细胞介素-1β和白细胞介素-18的表达，从而预防细胞焦亡。抑制miR-145-5p可逆转MEG3敲低的作用并促进细胞焦亡。TLR4抑制剂瑞斯托霉素抵消了miR-145-5p抑制剂的作用并抑制了细胞焦亡。我们的研究结果表明，MEG3通过miR-145-5p/TLR4/NLRP3轴促进细胞焦亡并加重CIRI，提示其可能是缺血性脑卒中的潜在治疗靶点。
