OBJECTIVES: To observe the role of miR-139-5p and Notch1 signaling pathway in regulation of homing of bone mesenchymal stem cells (BMSCs) of asthmatic rats. METHODS: Normal rat BMSCs were co-cultured with bronchial epithelial cells from normal or asthmatic rats, followed by transfection with miR-139-5p mimics or a negative control sequence. The changes in cell viability and cell cycle were analyzed, and the cellular expressions of CXCR4 and SDF-1 were detected using immunofluorescence staining. The changes of BMSC homing after the transfection were observed, and the expressions of Notch1, RBP-J, and Hes1 mRNAs and proteins and Th1/Th2 cytokines were detected with RT-qPCR, Western blotting or ELISA. RESULTS: The co-cultures of BMSCs and asthmatic bronchial epithelial cells showed significantly decreased expressions of miR-139-5p, IL-2 and IL-12 and increased expressions of CXCR4, SDF-1, IL-5, IL-9, Notch1, RBP-J, and Hes1. Transfection with miR-139-5p mimics significantly increased the expressions of miR-139-5p, IL-2, CXCR4 and SDF-1 and lowered the expression levels of IL-5, IL-9, Notch1, activated Notch1, and Hes1 in the co-cultured cells. Correlation analysis showed that BMSC homing was positively correlated with miR-139-5p and IL-12 and negatively correlated with IL-5 expression. The expression of CXCR4 was negatively correlated with activated Notch1, and SDF-1 was positively correlated with miR-139-5p but negatively correlated with Notch1 expression. CONCLUSIONS High expression of miR-139-5p promotes homing of BMSCs in asthma by targeting the Notch1 signaling pathway to regulate the expressions of Th1/Th2 cytokines, thereby alleviating airway inflammation.
Asthma/genetics* ; Animals ; Mesenchymal Stem Cells/cytology* ; MicroRNAs/metabolism* ; Rats ; Transcription Factor HES-1/genetics* ; Signal Transduction ; Receptor, Notch1/genetics* ; Immunoglobulin J Recombination Signal Sequence-Binding Protein/genetics* ; Receptors, CXCR4/genetics* ; Coculture Techniques ; Rats, Sprague-Dawley ; Chemokine CXCL12/genetics* ; Epithelial Cells/metabolism*

Development of alternatively activated (M2) macrophage phenotypes is a complex process that is coordinately regulated by a plethora of pathways and factors. Here, we report that RBP-J, a DNA-binding protein that integrates signals from multiple pathways including the Notch pathway, is critically involved in polarization of M2 macrophages. Mice deficient in RBP-J in the myeloid compartment exhibited impaired M2 phenotypes in vivo in a chitin-induced model of M2 polarization. Consistent with the in vivo findings, M2 polarization was partially compromised in vitro in Rbpj-deficient macrophages as demonstrated by reduced expression of a subset of M2 effector molecules including arginase 1. Functionally, myeloid Rbpj deficiency impaired M2 effector functions including recruitment of eosinophils and suppression of T cell proliferation. Collectively, we have identified RBP-J as an essential regulator of differentiation and function of alternatively activated macrophages.
Animals ; Cell Polarity ; drug effects ; genetics ; immunology ; Cell Proliferation ; drug effects ; genetics ; Chitin ; immunology ; pharmacology ; Eosinophils ; cytology ; immunology ; Gene Expression Regulation ; drug effects ; immunology ; Immunoglobulin J Recombination Signal Sequence-Binding Protein ; genetics ; immunology ; Macrophage Activation ; drug effects ; genetics ; Macrophages ; cytology ; immunology ; Mice ; Mice, Transgenic ; T-Lymphocytes ; cytology ; immunology