MicroRNA-424 Protects Against Focal Cerebral Ischemia and Reperfusion Injury in Mice by Suppressing Oxidative Stress

Abstract

513I schemic stroke is one of the leading causes of death and disability in the world, resulting from the disruption of blood supply to the brain. Intervention requires the restoration of blood flow, which can lead to reperfusion injury. Oxidative stress is thought to be the primary event during this process 1 because reperfusion stimulates an overproduction of reactive oxygen species (ROS), such as hydrogen peroxide (H 2 O 2 ), which leads to the oxidation of proteins, lipids, and DNA and can induce cell proliferation, growth arrest, apoptosis, and necrosis.2 Meanwhile, the dysfunction of superoxide dismutase (SOD) and glutathione peroxidase can compromise endogenous antioxidant defense mechanisms and further exacerbate oxidative stress and ischemic/reperfusion (I/R) injury.3,4 Nuclear factor erythroid 2-related factor (Nrf)2 activates the transcription of antioxidant stress genes whose products act concertedly to remove ROS through sequential enzymatic reactions. 5 Studies have uncovered the potential for Nrf2-mediated transcription to protect from neurodegeneration resulting from mechanisms involving oxidative stress. For this reason, Nrf2 is considered a valuable therapeutic target for free radical damage in brain after ischemia and reperfusion.MicroRNAs (miRs) are small (≈22 nt), noncoding, singlestranded RNA molecules that regulate gene expression at the posttranscriptional level by inhibiting translation or by cleaving RNA transcripts in a sequence-specific manner.6 MiR-424 is a tumor marker that is involved in cancer cell proliferation, Background and Purpose-We previously showed that the microRNA miR-424 protects against permanent cerebral ischemic injury in mice by suppressing microglia activation. This study investigated the role of miR-424 in transient cerebral ischemia in mice with a focus on oxidative stress-induced neuronal injury. Methods-Transient cerebral ischemia was induced in C57/BL6 mice by middle cerebral artery occlusion for 1 hour followed by reperfusion (ischemia/reperfusion). The miR-424 level in the peri-infarct cortex was quantified. Mice were also administered miR-424 angomir by intracerebroventricular injection. Cerebral infarct volume, neuronal apoptosis, and levels of oxidative stress markers and antioxidants were evaluated. In an in vitro experiment, primary cortical neurons were exposed to H 2 O 2 and treated with miR-424 angomir, nuclear factor erythroid 2-related factor 2 siRNA, and superoxide dismutase (SOD) inhibitor; cell activity, lactate dehydrogenase release, malondialdehyde level, and manganese (Mn)SOD activity were then evaluated. Results-MiR-424 levels in the peri-infarct cortex increased at 1 and 4 hours then decreased 24 hours after reperfusion.Treatment with miR-424 decreased infarct volume and inhibited neuronal apoptosis after ischemia/reperfusion, reduced reactive oxygen species and malondialdehyde levels in the cortex, and increased the expression and activation of MnSOD as well as the expression of extracellular SOD and the redox-sensitive transcription fact...

MicroRNA-93 Downregulation Ameliorates Cerebral Ischemic Injury Through the Nrf2/HO-1 Defense Pathway

“…Oxidative stress is a core pathological component of brain ischemiareperfusion injury causing neuronal malfunction and cell death [32][33][34]. Several miRNAs have been reported to be involved in the cellular response to oxidative stress via the antioxidant defense system [22,24]. As expected, we found that treatment with miR-93 antagomir reduced ROS and MDA levels in the ischemic brain of I/R mice, and increased the SOD activity as well as the expression of HO-1 and Nrf2.…”

“…miR-93 antagomir (100 μm) or the control (100 μm) were mixed with Lipofectamine RNAiMAX Transfection Reagent (Invitrogen, Carlsbad, CA) and incubated at room temperature for 30 min; 7 μL of the mixture was injected into the right lateral ventricle and the needle was kept in the place for 10 min before the MCAO [22]. The injection position was at the point of 0.5 mm posterior to bregma, 1.0 mm lateral to bregma, and 3.5 mm below the skull surface.…”

Noncoding RNAs and Their Potential Therapeutic Applications in Tissue Engineering

“…Neural stem/progenitor cells Promote proliferation miR-25 [12]; miR-137 [13]; miR-184 [14]; miR-195 [15] Induce differentiation miR-9, siRNA-TLX [16]; let-7d [17]; miR-137 [13]; miR-184 [14]; miR-195 [15]; miR-34a [18]; lncRNA-BDNF-AS, siRNA-BDNF-AS [19] Mesenchymal stem cells Induce differentiation miR-9 [20]; miR-124 [21] Reduce differentiation miR-128 [22] Neuronal cells Inhibit cell death miR-223 [23]; miR-181c [24]; miR-592 [25]; miR-424 [26]; miR-23a-3p [27]; miR-23a/b, miR-27a/b, siRNA-Apaf-1 [28] Promote cell death miR-134 [29]; miR-200c [30]; miR-30a/b [31][32][33]; miR-124 [34]; miR-711 [35] Regulate degeneration and apoptosis miR-20a [36]; miR-29b [37]; miR-146a, siRNA-miR146a [38] Promote neurite outgrowth miR-7 [39]; miR-21 [40]; miR-222, siRNA-PTEN [41]; miR-8 [42]; miR-431 [43]; miR-145 [44]; lncRNA-uc.217 [45]; miR-138, siRNA-SIRT1 [46] Microglial cells Inhibit inflammation let-7c [47]; miR-124, siRNA-C/EBP-α [48] Promote pro-inflammation miR-155 [49] Inhibit activation let-7c-5p [50] Astrocytes P...…”

Actinidia chinensis Planch. Improves the Indices of Antioxidant and Anti‐Inflammation Status of Type 2 Diabetes Mellitus by Activating Keap1 and Nrf2 via the Upregulation of MicroRNA‐424

“…MiR-424 therapy prevents infarct volume and neuronal apoptosis, reduces the levels of reactive oxygen species (ROS) and malondialdehyde (MAD), and enhances the activities of the antioxidant enzyme SOD. All the results suggest that miR-424 has protective effects against oxidative stress [15]. On the other hand, the nuclear factor, erythroid-derived 2-like 2 (Nrf2), is a redox-sensitive transcription factor and related with inflammatory disease [16, 17].…”