Fig. 7.

miR-146a-5p protected H9C2 cells from hypoxia injury by downregulating IRAK1 and inhibiting the nuclear translocation of the NF-κB p65 subunit. A The miR-146a-5p level of H9C2 cells was significantly reduced under H/SD conditions (n = 5). miR-146a-5p mimics significantly increased (B) or miR-146a-5p inhibitors significantly decreased (C) miR-146a-5p levels in H9C2 cells (n = 3). Representative images of the flow cytometry assay (D) and quantification (E) of apoptotic H9C2 cells transfected with miR-146a-5p mimics, inhibitors or the corresponding negative control (n = 5). F Luciferase activity assay of miR-146a-5p mimics-treated HEK293T cells, which overexpressed either IRAK1-wild-type or IRAK1-mutant. Under H/SD conditions, both the mRNA (G, n = 4) and protein levels of IRAK1 (H-I, n = 4) were obviously reduced. J The mRNA level of Irak1 in H9C2 cells transfected with miR-146a-5p mimics, inhibitors or NC (n = 4). Representative western blotting images (K) and quantification (L) of the relative level of IRAK1 (n = 4). Western blotting images (M or O) and quantification (N or P) of the relative level of IRAK1 in MSCs^TXL treatment in vivo or in vitro. Representative images (Q) and quantification (R) of the relative level of NF-κB p65 (n = 3). Representative images of flow cytometry (S) and quantification (T) of apoptotic H9C2 cells transfected with IRAK1 siRNA or its NC (n = 4). Representative western blotting images (U) and quantification (V) of nuclear NF-κB p65 levels in H9C2 cells transfected with IRAK1 siRNA or its NC (n = 3). All data are presented as the mean ± SD. Statistical analysis was performed with one-way ANOVA or student’s t test. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001