Melanoma cell adhesion molecule-positive mesenchymal stromal cells alleviate acute respiratory distress syndrome via nuclear factor kappa-B-mediated paracrine regulation

Figure 6 The nuclear factor kappa B inhibitor caffeic acid phenethyl ester reverses the improvement effect of CD146+ mesenchymal stromal cells on pulmonary endothelial barrier injury in acute respiratory distress syndrome. A: Permeability of HULEC-5a/HPAEpic-II-SV40 cells cocultured with CD146+ mesenchymal stromal cells (MSCs) and treated with caffeic acid phenethyl ester for 24 hours; B: The expression of tumor necrosis factor-α, interleukin-8, and interleukin-6 in HULEC-5a cells was measured via enzyme-linked immunosorbent assay; C: HULEC-5a cell apoptosis was assessed by Annexin V-FITC and propidium iodide double-staining, followed by flow cytometry analysis after treatment with CD146+ MSCs + caffeic acid phenethyl ester for 24 hours. Representative flow cytometry patterns from different groups are shown; D: Cell apoptosis was measured by Annexin V-APC and propidium iodide double staining and flow cytometric analysis. Representative flow cytometry patterns from different groups are shown. The percentages of apoptotic cells in the different groups were calculated according to the flow cytometric results; E: Protein levels of protein kinase A, phospho-protein kinase A, cyclic-AMP response element-binding protein, phospho-cyclic-AMP response element-binding protein; F: Western blot analysis of zonula occludens-1, VE-cadherin, and GAPDH protein expression in HULVE-a cells after lipopolysaccharide (LPS)-induced modeling (24 hours) and different treatments; G: The density of each individual band was compared to that of the corresponding control band and normalized to that of GAPDH by densitometry. Groups: Control, LPS, LPS + CD146+ MSC, and LPS + CD146+ MSC + caffeic acid phenethyl ester. The data are presented as the mean ± SD and were analyzed by two-sided Student’s t tests. n = 3. ^aP < 0.05, ^bP < 0.01, ^cP < 0.001, ^dP < 0.0001. LPS: Lipopolysaccharide; TNF: Tumor necrosis factor; IL: Interleukin; CAPE: Caffeic acid phenethyl ester; MSC: Mesenchymal stromal cell; PKA: Protein kinase A; CREB: Cyclic-AMP response element-binding protein; ZO-1: Zonula occludens-1.