Endothelium-Targeted Deletion of microRNA-15a/16-1 Promotes Poststroke Angiogenesis and Improves Long-Term Neurological Recovery

Abstract

Rationale: Angiogenesis promotes neurological recovery after stroke and is associated with longer survival of stroke patients. Cerebral angiogenesis is tightly controlled by certain microRNAs (miRs), such as the miR-15a/16-1 cluster, among others. However, the function of the miR-15a/16-1 cluster in endothelium on postischemic cerebral angiogenesis is not known. Objective: To investigate the functional significance and molecular mechanism of endothelial miR-15a/16-1 cluster on angiogenesis in the ischemic brain. Methods and Results: Endothelial cell-selective miR-15a/16-1 conditional knockout (EC-miR-15a/16-1 cKO) mice and wild-type littermate controls were subjected to 1 hour middle cerebral artery occlusion followed by 28-day reperfusion. Deletion of miR-15a/16-1 cluster in endothelium attenuates post-stroke brain infarction and atrophy and improves the long-term sensorimotor and cognitive recovery against ischemic stroke. Endothelium-targeted deletion of the miR-15a/16-1 cluster also enhances post-stroke angiogenesis by promoting vascular remodeling and stimulating the generation of newly formed functional vessels, and increases the ipsilateral cerebral blood flow. Endothelial cell-selective deletion of the miR-15a/16-1 cluster up-regulated the protein expression of pro-angiogenic factors VEGFA (vascular endothelial growth factor), FGF2 (fibroblast growth factor 2), and their receptors VEGFR2 (vascular endothelial growth factor receptor 2) and FGFR1 (fibroblast growth factor receptor 1) after ischemic stroke. Consistently, lentiviral knockdown of the miR-15a/16-1 cluster in primary mouse or human brain microvascular endothelial cell cultures enhanced in vitro angiogenesis and up-regulated pro-angiogenic proteins expression after oxygen-glucose deprivation, whereas lentiviral overexpression of the miR-15a/16-1 cluster suppressed in vitro angiogenesis and down-regulated pro-angiogenic proteins expression. Mechanistically, miR-15a/16-1 translationally represses pro-angiogenic factors VEGFA, FGF2, and their receptors VEGFR2 and FGFR1, respectively, by directly binding to the complementary sequences within 3′-untranslated regions of those messenger RNAs. Conclusions: Endothelial miR-15a/16-1 cluster is a negative regulator for postischemic cerebral angiogenesis and long-term neurological recovery. Inhibition of miR-15a/16-1 function in cerebrovascular endothelium may be a legitimate therapeutic approach for stroke recovery.

Coicis semen protects against focal cerebral ischemia-reperfusion injury by inhibiting oxidative stress and promoting angiogenesis via the TGFβ/ALK1/Smad1/5 signaling pathway

“…Occurring in the penumbra region as early as 12 h after stroke, angiogenesis was shown to last for more than 21 days following cerebral ischemia in rodent experiments [ 40 , 41 ]. Angiogenesis in the ischemic boundary region after ischemic stroke contributes to the reformation of neuropil networks and restoration of blood flow and neuronal metabolism in tissue at risk [ 42 ]. Consistent with previous studies [ 13 ], our findings also confirmed that the expression of CD31 (an angiogenesis marker) gradually increased throughout a prolonged recovery period (1-14 days after MCAO).…”

Dendritic cell‑derived exosomal miR‑494‑3p promotes angiogenesis following myocardial infarction

“…Regarding the mechanism through which DEXs promote angiogenesis post-MI, previous studies demonstrated that EXs secreted by cells contain a large number of miRNAs ( 21 , 26 ), some of which have been confirmed by several studies to be associated with angiogenesis ( 11 , 12 , 30 , 31 ). Therefore, the miRNAs in splenic DCs of MI model mice were screened using Affymetrix miRNA 4.0 microarrays, and the expression levels of miR-451a, miR-494-3p and miR-16a-5p, which are associated with angiogenesis, were found to be significantly increased compared with that in sham mice.…”

“…miRNAs are short, non-coding RNAs that regulate gene expression through translational repression or degradation of target mRNAs ( 9 ). Over the last decade, miRNAs have emerged as key regulators of several cellular processes, including angiogenesis, and certain miRNAs, such as miR-132, miR-126, miR-451a, miR-494-3p, miR-16a-5p and miR-23a-3p, have been shown to play key roles in the vasculature in both endothelial and perivascular cells ( 11 , 12 ). In addition, previous studies have demonstrated that EXs contain a large number of miRNAs, and EXs may deliver these miRNAs to their target cells ( 13 - 15 ).…”

The Effect of HRE-Regulated VEGF Expression and Transfection on Neural Stem Cells in Rats

“…Vascular endothelial growth factor, a specific mitogen of endothelial cells, can specifically promote the proliferation, migration and angiogenesis of vascular endothelial cells. It has a direct protective effect on the nervous system before the formation of new blood vessels, and can help prolong the life of cells, reduce neuronal damage, and promote neuronal repair and NSC proliferation (Wei et al, 2017;Li et al, 2019;Sun et al, 2020). We constructed a recombinant lentiviral vector, pGC-FU-VEGF165, carrying VEGF165 gene, and transfected the VEGF gene with the lentivirus into the neural stem cells of fetal rat brain.…”