Cardioprotective Effect of circ_SMG6 Knockdown against Myocardial Ischemia/Reperfusion Injury Correlates with miR-138-5p-Mediated EGR1/TLR4/TRIF Inactivation

Figure 3

circ_SMG6 competitively binds to miR-138-5p and thus attenuates the binding of miR-138-5p to EGR1. (a) Binding sites between miR-138-5p and EGR1 in human (the top) and mice (the bottom) predicted by the RNA22 database. (b) Binding of miR-138-5p to EGR1 verified by dual-luciferase reporter assay in HEK-293 T cells. (c) Expression of miR-138-5p and EGR1 determined with qRT-PCR in HL-1 cells treated with miR-138-5p mimic/inhibitor. (d) A box plot of the mmu_circ_0000288 (circ_SMG6) expression in myocardial samples of I/R mice () and sham-operated mice () in circRNA sequencing. (e) Binding sites between miR-138-5p and circ_SMG6 in human and mice predicted by the RNA22 database. (f) Binding of miR-138-5p to circ_SMG6 verified by dual-luciferase reporter assay in HEK-293T cells. (g) Enrichment of circ_SMG6 determined by RIP assay in the cells treated with biotin-miR-138-5p. (h) Expression of miR-138-5p and circ_SMG6 determined by qRT-PCR in myocardial tissues of I/R and sham-operated mice. (i) Correlation of circ_SMG6 expression with the miR-138-5p expression and EGR1 expression analyzed by Pearson’s correlation coefficient in myocardial tissues of I/R mice. (j) Expression of circ_SMG6, miR-138-5p, and EGR1 determined with qRT-PCR in HL-1 cells treated with oe-circ_SMG6 or sh-EGR1 or their combination. vs. the sham-operated mice, HEK-293T cells transfected with NC mimic or HL-1 cells treated with biotin-NC or HL-1 cells treated with oe-NC + sh-NC; # vs. cells treated with oe-circ_SMG6 + sh-NC. Cell experiments were conducted three times independently. for mice following each treatment.

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