MiRNA-424 Protects Against Permanent Focal Cerebral Ischemia Injury in Mice Involving Suppressing Microglia Activation

Abstract

MiR-424 is a member of the miR-16 family. The genomic organization of miR-424 and miR-503 suggested that they are part of the same transcriptional unit .2 Increasing evidence indicates the crucial role of miR-424 in regulation of cell differentiation. A study in human cord blood CD34+ cells showed that miR-424 is highly expressed during monocyte/ macrophage differentiation , 3 and miR-424 overexpression promotes the maturation of monoblastic cell . 4 Two transcriptional start sites for the pri-miR-424 have been identified at upstream of the pre-miRNA 5′end. The PU.1 factor was shown to interact with the miR-424 promoter and to be responsible for its activation . 3,5,6 In addition, miR-322/424 is induced during muscle differentiation through cdk2 inhibition . 7 MiR-424 expression in human bone marrow-derived mesenchymal stem cells was reported to be higher than in osteoblasts and chondrocytes.8 However, miR-424 was found to negatively regulate the adipogenic differentiation of human adipose tissue-derived mesenchymal stem cells, 9 suggestingBackground and Purpose-We observed that microRNA-424 (miR-424) significantly decreased in an miRNA profile of circulating lymphocytes of patients with ischemic stroke. The present study focused on the potential and mechanism of miR-424 in protecting ischemic brain injury in mice. Methods-Cerebral ischemia was induced by middle cerebral artery occlusion in C57/BL6 mice. Cerebral infarction volume, neuronal apoptosis, and microglia activation were determined by 2,3,5-triphenyltetrazolium chloride staining, immunofluorescence, and Western blot. BV2 microglial cell activity, cell cycle, mRNA, and protein levels of miR-424 targets were accessed by enzyme-linked immunosorbent assay, flow cytometry, real-time polymerase chain reaction, and Western blot, respectively. Results-MiR-424 levels were decreased in the plasma of patients with acute ischemic stroke, as well as in mouse plasma and ipsilateral brain tissue at 4, 8, and 24 hours after ischemia, likewise, in the cortex, hippocampus, and basal ganglia, respectively, after 8-hour ischemia. Interestingly, pre-and post-treatment with overexpression of miR-424 both decreased cerebral infarction size and brain edema after middle cerebral artery occlusion. Meanwhile, lentiviral overexpression of miR-424 inhibited neuronal apoptosis and microglia activation, including suppressing ionized calcium binding adaptor molecule-1 immunoreactivity and protein level, and reduced tumor necrosis factor-α production. In vitro study demonstrated that miR-424 mimics caused G1 phase cell-cycle arrest, inhibited BV2 microglia activity, and reduced the mRNA and protein levels of CDC25A, cyclin D1, and CDK6 in BV2 microglial cells, which were upregulated in brain of middle cerebral artery occlusion mice. Conclusions-MiR-424 overexpression lessened the ischemic brain injury through suppressing microglia activation by translational depression of key activators of G1/S transition, suggesting a novel miR-based intervention strategy for stroke. (Stroke. 2013;44...

Long Noncoding RNA H19 Promotes Neuroinflammation in Ischemic Stroke by Driving Histone Deacetylase 1–Dependent M1 Microglial Polarization

“…17 From mice subjected to MCAO, the blood (≈500 μL) and the ischemic hemisphere from mice were collected 24 hours after ischemia. Approximately 200 μL of plasma and brain homogenates (10%, wt/vol) were prepared with ice-cold phosphate-buffered solution.…”

The MicroRNA 424/503 Cluster Reduces CDC25A Expression during Cell Cycle Arrest Imposed by Transforming Growth Factor β in Mammary Epithelial Cells

“…Targeting of CDC25A by microRNA 424(322)/503 [miR-424(322)/503] has previously been found in endothelial (12), microglial (13), and muscle (14) cells. However, a role for the miR-424(322)/503 cluster in the regulation of CDC25A in mammary epithelial cells has not been previously described.…”

Advances in biomarker for stroke patients: from marker to regulator

“…Since many [71]. In stroke field, increased or decreased levels of several circulating microRNA were reported in isch emic stroke patients [72,73]. For example, microRNA424 lev el was decreased in acute stroke patients and in an animal model of stroke, and intracerebroventricular injection of len tiviral microRNA424 reduced ischemic brain injury [72].…”

“…In stroke field, increased or decreased levels of several circulating microRNA were reported in isch emic stroke patients [72,73]. For example, microRNA424 lev el was decreased in acute stroke patients and in an animal model of stroke, and intracerebroventricular injection of len tiviral microRNA424 reduced ischemic brain injury [72]. On the contrary, poststroke increase in microRNA200c contrib uted to ischemic brain injury by inhibiting reelin expression and inhibition of micro RNA200c resulted in an increase in cell survival [74].…”