Soluble PTX3 of Human Umbilical Cord Blood-Derived Mesenchymal Stem Cells Attenuates Hyperoxic Lung Injury by Activating Macrophage Polarization in Neonatal Rat Model

Figure 5

Reduced therapeutic effect of UCB-MSCs by PTX3 knockdown in a rat hyperoxic lung injury model. Normal rats maintained in normoxia room air, whereas hyperoxic rats were raised in hyperoxic chambers (90% oxygen) from birth until P14 and then intratracheally injected with MSCs (naïve, control siRNA MSC, and PTX3 siRNA). Nine days after cell treatment, lung tissue and lung BALF were collected. (a) Survival rate for 14 days after birth. (b) Histologic and morphometric analysis of rat lung tissue. Representative microscopy photomicrographs of lung tissue with hematoxylin and eosin (H&E) staining. . Degree of alveolarization shown as the mean linear intercept (MLI, μm). Error bars represent the , per group; vs. normal. ⁺⁺ vs. BPD. ^ΔΔ vs. BPD+naïve MSC. ^◆◆ vs. BPD+Con siRNA MSC. (c, d) Representative immunofluorescence staining using macrophage markers (CD11b, CD163) in rat lung tissue. Expression of CD11b (c, red) and CD163 (d, green) was counted as positively stained cells. (e) Expression of Dectin-1 (green) in lung tissue was counted as positively stained cells. (f) Immunohistochemical detection of human β2MG (green) in lung tissue. (c–f) Nuclei stained with Hoechst 33342. . (g) Secretion levels of rat IL-6, rat IL-8, and rat IL-10 in the lung BALF. (c–g) Error bars represent the , per group; , vs. normal. ⁺, ⁺⁺ vs. BPD. ^Δ, ^ΔΔ vs. BPD+naïve MSC. ^◆, ^◆◆ vs. BPD+Con siRNA MSC. BPD: bronchopulmonary dysplasia; hyperoxic lung injury.

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