LncRNA XIST Exacerbates Oxygen-Glucose Deprivation/Reoxygenation-Induced Cerebral Injury Through the miR-25-3p/TRAF3 Axis.

Ischemic stroke causes lethal damage to the brain. Identifying key regulators of OGD/R-induced cerebral injury is important for developing novel therapies for ischemic stroke. HMC3 and SH-SY5Y cells were treated with OGD/R as an in vitro ischemic stroke model. Cell viability and apoptosis were determined via CCK-8 assay and flow cytometry. Inflammatory cytokines were examined by ELISA. Luciferase activity was measured for evaluating the interaction of XIST, miR-25-3p, and TRAF3. Bcl-2, Bax, Bad, cleaved-caspase 3, total caspase 3, and TRAF3 were detected via western blotting. HMC3 and SH-SY5Y cells showed increased XIST expression and decreased miR-25-3p expression following OGD/R. Importantly, silencing of XIST and overexpression of miR-25-3p reduced apoptosis and inflammatory response following OGD/R. Furthermore, XIST worked as a miR-25-3p sponge, and miR-25-3p targeted TRAF3 to suppress its expression. Moreover, the knockdown of TRAF3 ameliorated OGD/R-induced injury. Loss of XIST-mediated protective effects was reversed by overexpression of TRAF3. LncRNA XIST exacerbates OGD/R-induced cerebral damage via sponging miR-25-3p and enhancing TRAF3 expression.

OIP5-AS1 Inhibits Oxidative Stress and Inflammation in Ischemic Stroke Through miR-155-5p/IRF2BP2 Axis.

BACKGROUND: Ischemic stroke is a very dangerous disease with high incidence, fatality and disability rate in human beings. Massive evidence has indicated that oxidative stress and inflammation are intimately correlated with progression of ischemic stroke. Additionally, LncRNAs were reported to be involved in ischemic stroke. Here, we aim to explore the effects and molecular mechanism of lncRNA OIP5-AS1 on oxidative stress and inflammation in ischemic stroke. METHODS: HMC3 and SH-SY5Y cells were under the condition of oxygen-glucose deprivation/reoxygenation (OGD/R) treatment to establish cell models of ischemic stroke. Commercial kits were employed to detect the indicators of oxidative stress including ROS, MDA and SOD. The expression of OIP5-AS1, miR-155-5p and IRF2BP2 mRNA was determined using RT-qPCR. The protein levels of inflammatory factors including TNF-α, IL-1ß and IL-6 and IRF2BP2 were assessed by western blot and/or ELISA. Luciferase activity assay was employed to validate their correlations among OIP5-AS1, miR-155-5p and IRF2BP2. RESULTS: In OGD/R-induced HMC3 and SH-SY5Y cells, the expression of OIP5-AS1 and IRF2BP2 was reduced while miR-155-5p was elevated. OGD/R induction promoted oxidative stress and inflammatory response in HMC3 and SH-SY5Y cells, while OIP5-AS1 or IRF2BP2 sufficiency as well as miR-155-5p inhibitor attenuated OGD/R-induced these influences. In addition, IRF2BP2 knockdown abolished the suppressive impacts of OIP5-AS1 overexpression on oxidative stress and inflammatory response in OGD/R-induced HMC3 and SH-SY5Y cells. Mechanistically, OIP5-AS1 enhanced IRF2BP2 expression via sponging miR-155-5p. CONCLUSION: OIP5-AS1 suppressed oxidative stress and inflammatory response to alleviate cell injury caused by OGD/R induction in HMC3 and SH-SY5Y cells through regulating miR-155-5p/IRF2BP2 axis, which might offer novel targeted molecules for ischemic stroke therapy.

LncRNA LINC00689 Promotes the Tumorigenesis of Glioma via Mediation of miR-526b-3p/IGF2BP1 Axis.

Glioma ranks first among the aggressive brain tumors all over the world. LncRNA LINC00689 has been confirmed to play key roles in the progression of cancers, and LINC00689 was upregulated in glioma. However, the biological function of LINC00689 in glioma is unclear. qRT-PCR was applied to detect the expressions of LINC00689 and miR-526b-3p in glioma cells. Dual-luciferase report was performed to examine the relation among LINC00689, miR-526b-3p, and insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1). Then, the growth, migration, and invasion of glioma cells were detected by colony formation, flow cytometry, and transwell assay, respectively. The expressions of p21, cleaved caspase 3, and MAPK signaling-related proteins in glioma cells were tested by western blotting. Finally, xenograft mice model was established to detect the effect of LINC00689 on tumor growth of glioma in vivo. LINC00689 was upregulated in glioma cells, while miR-526b-3p was downregulated. In addition, LINC00689 bound to miR-526b-3p, and IGFBP1 was targeted by miR-526b-3p. Moreover, LINC00689 knockdown or upregulation of miR-526b-3p inhibited the proliferation of glioma cells and induced the apoptosis. Consistently, the migration and invasion of glioma cells were notably reduced by LINC00689 shRNA/miR-526-3p mimics. miR-526b-3p inhibitor or IGF2BP1 upregulation could reverse the effect of LINC00689 knockdown or miR-526b-3p mimics. Finally, knockdown of LINC00689 inhibited the tumor growth of glioma in vivo through regulating miR-526b-3p/IGF2BP1/MAPK axis. In conclusion, silencing of LINC00689 could inhibit the tumorigenesis of glioma via mediation of miR-526b-3p/IGF2BP1 axis. LINC00689 may serve as a new target for the treatment of glioma.

LncRNA H19 Aggravates Cerebral Ischemia/Reperfusion Injury by Functioning as a ceRNA for miR-19a-3p to Target PTEN.

Long non-coding RNAs (lncRNAs) play critical roles in regulating the progression of cerebral ischemia. LncRNA H19 was significantly up-regulated under ischemia-reperfusion (I/R) damage and implicatedin I/R injury progression, but the mechanisms remain unclear. Mice were subjected to middle cerebral artery occlusion (MCAO)/R (1 h/24 h) to build an I/R injury model and the infarct volume and neurological deficit were assessed. Human neuroblastoma cell line SH-SY5Y was used in oxygen-glucose deprivation and reperfusion (OGD/R, 3 h/24 h) injury model. Expression of genes were evaluated by qRT-PCR or western blotting. Flow cytometry and TUNEL were performed to examine apoptosis. Cell viability was determined with CCK8 assay. LDH, MDA, SOD levels were evaluated using commercial detection kits. Furthermore, dual luciferase reporter assay was conducted to confirm the binding between H19 and miR-19a-3p, as well miR-19a-3p and PTEN. The results showed that H19 was up-regulated whereas miR-19a-3p was down-regulated in I/R tissues and OGD/R induced cells. H19 aggravated I/R or OGD/R caused oxidative stress and apoptosis via PTEN/Akt signaling pathway. H19 regulated PI3K/AKTsignaling through acting as a ceRNA for miR-19a-3p to target PTEN. H19 knockdown and miR-19a-3p overexpression relieved I/R or OGD/R induced neuronal cell oxidative stress and apoptosis. H19/miR-19a-3p/PTEN axis could promote cerebral I/R injury via PI3K/AKT pathway. These demonstrated a mechanism how H19 participates in I/R injury, and provided us a potential target for I/R injury diagnosis and treatment.