RESUMO
This study aimed to investigate whether bone marrow-derived mesenchymal stem cells (BM-MSCs) can inhibit function of dendritic cells (DCs) by secreting Galectin-1 (Gal-1). BM-MSCs have been shown to inhibit the maturation and function of DCs, further inhibiting the activation and proliferation of T cells. However, the detailed mechanism remains unknown. In this current study, MSCs and DCs derived from mouse bone marrow were cocultured using Transwell culture plates under different in vitro conditions. The results showed that as the ratio of MSC to DC of the coculture system increased and the coculture time of the two cells prolonged, the concentrations of Gal-1, interleukin- (IL-) 10, and IL-12 in the supernatants were increased and the protein expression of Gal-1 on and within DCs was also enhanced. The phosphorylation of extracellular signal-regulated kinase (ERK) pathway in DCs was boosted, whereas p38 mitogen-activated protein kinase (MAPK) pathway phosphorylation was weakened. Meanwhile, the expression of costimulatory molecules on the surface of DCs was decreased, and the proliferative effect of DCs on allogeneic T cells was also decreased. Therefore, this present study indicated that Gal-1 secreted from MSCs upregulated expression of Gal-1 and stimulated formation of tolerance immunophenotype on DCs, where the underlying mechanism was the regulation of the MAPK signaling pathway in DCs, thereby inhibiting the function of DCs.
Assuntos
Células da Medula Óssea/metabolismo , Células Dendríticas/metabolismo , Galectina 1/genética , Células-Tronco Mesenquimais/metabolismo , Animais , Proliferação de Células/genética , Galectina 1/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/genética , Interleucina-10/genética , Interleucina-12/genética , Sistema de Sinalização das MAP Quinases/genética , Camundongos , Linfócitos T/metabolismoRESUMO
OBJECTIVE: To observe the differentiation of bone mesenchymal stem cells (BMSCs) co-cultured with purified sinoatrial node cells (SNC) of neonate rats. METHODS: SNC from neonatal SD rat were cultured and purified with differential attachment method and labeled with BrdU. Rat BMSCs were isolated by a Percoll's gradient solution and cultured in DMEM. After 2 passages, these BMSCs were transfected with pEGFP-N1 by Lipofectamine and labeled with GFP. EGFP-BMSC were co-cultured with SNC in a rate of 1:5 for 1 week. EGFP-BMSC cultured in SNC culture medium served as controls. SNC marker hyperpolarization activated cyclic nucleotide gated cation channel 4 (HCN4) and connexin 45 (Cx45) expressions were determined by immunofluorescence staining. RESULT: Positive immunofluorescence staining against HCN4 and Cx45 were detected in EGFP-BMSC co-cultured with SNC but not in EGFP-BMSC cultured in SNC culture medium. CONCLUSION: Direct cell-to-cell contact between BMSCs and SNC cells may induce BMSCs differentiation into sinus node-like cells.
