Circular RNA DLGAP4 Ameliorates Ischemic Stroke Outcomes by Targeting miR-143 to Regulate Endothelial-Mesenchymal Transition Associated with Blood–Brain Barrier Integrity

Abstract

Circular RNAs (circRNAs) are highly expressed in the CNS and regulate physiological and pathophysiological processes. However, the potential role of circRNAs in stroke remains largely unknown. Here, we show that the circRNA DLGAP4 (circDLGAP4) functions as an endogenous microRNA-143 (miR-143) sponge to inhibit miR-143 activity, resulting in the inhibition of homologous to the E6-AP C-terminal domain E3 ubiquitin protein ligase 1 expression. circDLGAP4 levels were significantly decreased in the plasma of acute ischemic stroke patients (13 females and 13 males) and in a mouse stroke model. Upregulation of circDLGAP4 expression significantly attenuated neurological deficits and decreased infarct areas and blood-brain barrier damage in the transient middle cerebral artery occlusion mouse stroke model. Endothelial-mesenchymal transition contributes to blood-brain barrier disruption and circDLGAP4 overexpression significantly inhibited endothelial-mesenchymal transition by regulating tight junction protein and mesenchymal cell marker expression. Together, the results of our study are illustrative of the involvement of circDLGAP4 and its coupling mechanism in cerebral ischemia, providing translational evidence that circDLGAP4 serves as a novel therapeutic target for acute cerebrovascular protection.

Targeting MicroRNA-143 Leads to Inhibition of Glioblastoma Tumor Progression

“…Again, as the expression of miRNA-143 (as most miRNAs) is tissue- and time-dependent, its role in the intracellular glucose accumulation and the progression of GBM should be carefully interpreted [ 2 ]. Of note, recent reports indicate that the circular RNA, DLGAP4 (circDLGAP4) [ 56 ]; and the Mir-143 host gene (MIR143HG) [ 57 ] act as miRNA sponges that sequester miRNA-143, thus, reducing the ability of this miRNA to bind to its cognate targets.…”

<p>Restoration of UPK1A-AS1 Expression Suppresses Cell Proliferation, Migration, and Invasion in Esophageal Squamous Cell Carcinoma Cells Partially by Sponging microRNA-1248</p>

“…The RNA pull-down assay was conducted as described. 22,23 EC109 and KYSE30 cells were seeded and cultured for 24 h before transfection. Biotinylated miR-1248 (Bio-miR-1248) and miR-NC (Bio-miR-NC) were synthesized from Sangon Biotech, and transfected into EC109 and KYSE30 cells at a final concentration of 50 nM using LipofectamineTM 2000 (Invitrogen).…”

Circular RNAs as Therapeutic Agents and Targets

“…circDLGAP4 , a proposed miR-143 sponge, was less abundant in brain tissue in a rodent cerebral stroke model, and in blood plasma of human acute ischemic stroke patients ( Bai et al, 2018 ). The circRNAs has one seed-matched binding site for miR-143 .…”

“…Overexpression of native protective circRNAs has been achieved from RNAP II-driven constructs on standard DNA expression vectors in cell culture ( Hansen et al, 2013 ; Memczak et al, 2013 ; Ashwal-Fluss et al, 2014 ; Li et al, 2015 ; Du et al, 2016 ; Holdt et al, 2016 ; Legnini et al, 2017 ), and from lentiviral or adenoviral vectors in vivo ( Wang et al, 2017 ; Bai et al, 2018 ; Xia et al, 2018 ) ( Figure 1A , see also Table 1 ). These encode a mini-gene cassette with exon(s), endogenous splice donor and acceptor sites, and flanking intronic inverted repeats that support RNA backfolding ( Figure 1A ).…”