Figure 5.

Decorin knockdown suppressed the therapeutic effects of MSCs by down-regulating macrophage polarization. Decorin-silenced MSCs were intratracheally injected in BPD rats. (a) Decorin siRNA-transfected MSCs were intratracheally injected on day 5. Daily survival rates during 14 d from birth are presented as Kaplan–Meier survival curves. (b) Lung tissues on P14 were analyzed by histological and morphogenic comparison with the control group (normal). The mean linear intercept (MLI) values were determined by the degree of alveolarization. (c) Lung tissue samples were sectioned and stained with H&E. Data are presented as mean ± SD for n = 11 (normal), 15 (BPD, BPD with MSC), or 14 (co-cultured with MSCs or scrambled siRNA-transfected MSCs (Con siR-MSC), Decorin siR-MSC) per group. ** p < 0.01, *p < 0.05. n/s, not significant; BPD, bronchopulmonary dysplasia. (d,d’–f,f’) Immunofluorescence analysis was performed with CD11b, CD163, and CD44 antibodies in lung tissues obtained from rats with hyperoxic lung injury. (g,g’) Transplanted MSCs were detected by hβ2MG (green) staining of rat lung tissues. Blue staining represents nuclei stained with Hoechst 33342. Red (CD11b) and green (CD163 and CD44) staining indicate positive cells. (h–j) The levels of cytokines IL-8, IL-6, and IL-10, were analyzed by ELISA on P14. Data are presented as mean ± SD, n = 5 per group. Scale bar = 40 μm. ** p < 0.01, * p < 0.05. n/s, not significant; MΦ, macrophage; L, LPS.