Figure 5. Exosomal miR-146a-5p decreases microglial pro-inflammatory activity by suppressing the IRAK1/TRAF6 signaling pathway in vitro. (A) Expression levels of the top ten hUMSC-Exosomal miRNAs, including MiR-146a-5p. (B) After post-OGD exposure to hUMSC-Exos, BV2 microglia exhibited significantly increased miR-146a-5p content. Data were normalized to levels of U6. (C) In vitro experimental scheme. (D) Expression of pro-inflammatory cytokines IL-6, TNF-α, and IL-1β, as well as signaling pathway IRAK1, TRAF6, and NFκB (p65) in microglia treated with wild-type versus miR-146a-5p knockdown hUMSC-Exos. (E) Determination of IL-6, TNF-α, and IL-1β mRNA levels via qRT-PCR. (F) Determination of supernatant IL-6, TNF-α, and IL-1β protein levels via ELISA. Data are expressed as mean ± SEM. (A–F) Each experiment is representative of n = 3 per group. Significant differences are indicated (*p < 0.05, **p < 0.01, ***p < 0,001).