Department of Neurosurgery, Liaocheng People's Hospital, Liaocheng City, Shandong Province 252000, China; Department of Neurosurgery, Qilu Hospital of Shandong University, Jinan City, Shandong Province 250063, China.
Department of Healthcare Neurology, Provincial Hospital Affiliated to Shandong First Medical University, Jinan City, Shandong Province 250021, China.
Int Immunopharmacol. 2024 Jan 25;127:111310. doi: 10.1016/j.intimp.2023.111310. Epub 2023 Dec 15.
Cerebral ischemia-reperfusion injury (CIRI) can cause neuronal apoptosis and lead to irreversible brain injury. Numerous lncRNAs have been reported to play important roles in CIRI, but it is unclear whether these lncRNAs can function through exosomes.
In this study, we utilized the middle cerebral artery occlusion/reperfusion (MCAO/R) animal model and the oxygen-glucose deprivation/ reoxygenation (OGD/R) cell model. RNA sequencing was performed to screen for differentially expressed lncRNAs in M2 microglia-derived exosomes (M2-Exos). RNA pull-down, RNA immunoprecipitation, co-immunoprecipitation and ubiquitination assays were used to explore the molecular mechanism of OIP5-AS1 in alleviating CIRI.
M2-Exos could alleviate nerve injury and pyroptosis after CIRI in vitro and in vivo. OIP5-AS1 was found to be significantly up-regulated in M2-Exos and down-regulated in OGD/R neurons, MCAO/R mice and ischemic stroke patients. In MCAO/R mice, OIP5-AS1 could reduce cerebral infarct size, cerebral edema and mNSS scores, and inhibit the expression levels of pyroptosis-related proteins in brain tissue. TXNIP was confirmed to be a reliable binding protein of OIP5-AS1. OIP5-AS1 overexpression significantly attenuated MCAO/R-induced upregulation of TXNIP at the protein level, but not at the mRNA level. OIP5-AS1 promoted the TXNIP degradation process and increased the ubiquitination of TXNIP. ITCH could bind to TXNIP. ITCH overexpression or knockdown did not alter the mRNA level of TXNIP, but negatively regulated TXNIP expression at the protein level. ITCH accelerated the degradation and ubiquitination of TXNIP, which could be attenuated by OIP5-AS1 knockdown. OIP5-AS1 could improve neuronal damage and inhibit neuronal pyroptosis through TXNIP.
M2-Exo-derived OIP5-AS1 can induce TXNIP ubiquitination and degradation by recruiting ITCH, negatively regulate TXNIP protein stability, inhibit neuronal pyroptosis, and attenuate CIRI.
脑缺血再灌注损伤（CIRI）可引起神经元凋亡，导致不可逆的脑损伤。大量的长链非编码 RNA（lncRNA）已被报道在 CIRI 中发挥重要作用，但这些 lncRNA 是否能通过外泌体发挥作用尚不清楚。
在本研究中，我们利用大脑中动脉闭塞/再灌注（MCAO/R）动物模型和氧葡萄糖剥夺/复氧（OGD/R）细胞模型，对 M2 小胶质细胞衍生的外泌体（M2-Exos）中的差异表达 lncRNA 进行 RNA 测序筛选。采用 RNA 下拉、RNA 免疫沉淀、共免疫沉淀和泛素化测定等方法探讨 OIP5-AS1 在缓解 CIRI 中的分子机制。
M2-Exos 可减轻体外和体内 CIRI 后的神经损伤和细胞焦亡。OIP5-AS1 在 M2-Exos 中显著上调，在 OGD/R 神经元、MCAO/R 小鼠和缺血性脑卒中患者中下调。在 MCAO/R 小鼠中，OIP5-AS1 可减小脑梗死面积、脑水肿和 mNSS 评分，并抑制脑组织中细胞焦亡相关蛋白的表达水平。TXNIP 被确认为 OIP5-AS1 的可靠结合蛋白。OIP5-AS1 过表达可显著降低 MCAO/R 诱导的 TXNIP 蛋白水平的上调，但对 TXNIP 的 mRNA 水平没有影响。OIP5-AS1 促进了 TXNIP 的降解过程，并增加了 TXNIP 的泛素化。ITCH 可以与 TXNIP 结合。ITCH 过表达或敲低不改变 TXNIP 的 mRNA 水平，但可在蛋白水平上负调控 TXNIP 的表达。ITCH 加速了 TXNIP 的降解和泛素化，这一过程可被 OIP5-AS1 敲低所抑制。OIP5-AS1 可通过 TXNIP 改善神经元损伤并抑制神经元细胞焦亡。
M2-Exo 衍生的 OIP5-AS1 可通过募集 ITCH 诱导 TXNIP 泛素化和降解，负调控 TXNIP 蛋白稳定性，抑制神经元细胞焦亡，从而减轻 CIRI。
