Figure 6. Aging MSC-EVs were incapable of modulating macrophage polarization in vitro. (A–C) BMDMs (3 × 105 cells) were cultured with young or aging MSC-EVs (100 μg/ml) in a 24-well plate in the presence or absence of LPS (100 ng/ml). Cells were collected after 24 h and mRNA levels of pro-inflammatory cytokines IL-6, IL-1β, and TNF-α (A), M1 marker iNOS (B), and M2 markers TGF-β1 and Ym-1 (C) were analyzed via qRT-PCR. Data are presented as mean ± SEM, n = 6–8. *p < 0.05, **p < 0.01, *** p < 0.001.