Exosomes derived from microRNA-540-3p overexpressing mesenchymal stem cells promote immune tolerance via the CD74/nuclear factor-kappaB pathway in cardiac allograft

Figure 8 Exosome-derived miR-540-3p alleviates immune resistance after heterotopic heart transplantation. A: Histopathological observation of the heart after heterotopic heart transplantation using hematoxylin and eosin staining; B: Detection and calculation of the difference in ejection fraction before and after heterotopic heart transplantation; C: Detection and calculation of differences in the percentage of fractional shortening before and after heterotopic heart transplantation; D-G: Enzyme-linked immunosorbent assay-based quantitative analysis of cytokine production (interleukin-1β, interferon-γ, interleukin-10, transforming growth factor β1) in serum; H: Expression of microRNA-540-3p in extracted dendritic cells (DCs); I: Expression of microRNA-540-3p in extracted T cells; J-M: Flow cytometric analysis of the positive rate of cell surface markers in DCs (major histocompatibility complex II, CD80, CD86, and CD274); N-P: Flow cytometric analysis of the positive rate of T cells (CD4⁺ T, CD8⁺ T, and T regulatory cells); Q-S: Western blot analysis of the expression of CD74 and nuclear factor-kappaB (NF-κB) in extracted DCs; T-V: Western blot analysis of CD74 and NF-κB expression in the extracted T cells; W: Co-IP was used to detect the binding of CD74 and NF-κB in extracted DCs; X: Co-IP was used to detect the binding of CD74 and NF-κB in extracted T cells. ^aP < 0.05, ^bP < 0.01, ^cP < 0.001, ^dP < 0.0001. BMSC: Bone marrow mesenchymal stem cell; IDO: Indoleamine 2,3-dioxygenase; DC: Dendritic cell; LPS: Lipopolysaccharide; NF-κB: Nuclear factor-kappaB; MHC: Major histocompatibility complex; IL: Interleukin; TGF: Transforming growth factor; IFN: Interferon.