[Effect of Human Adipose Mesenchymal Stem Cells on Phenotype Polarization of Mice Microglia via TLR3/TRIF Signal Pathway].

OBJECTIVE

To explore the effect and mechanism of human adipose-derived mesenchymal stem cells (hADMSCs) on phenotypic polarization of microglia.

METHODS

BV-2 microglia of C57/BL6 mice were co-cultured with hADMSCs+lipopolysaccharide (LPS), or cultured with LPS alone. Cell morphology was observed under an inverted microscope. The effect of hADMSCs on microglial proliferation was evaluated by CCK-8 assay. The impact of hADMSCs on microglia M1/M2 phenotype markers were detected using quantitative real-time PCR (RT-qPCR). The affect of hADMSCs on the proteins expression levels of Toll-like receptor 4 (TLR4)-TIR domain containing adaptor protein inducing interferon β (TRIF) signaling pathway in BV-2 microglia was detected by using Western blot analysis.

RESULTS

As compared with the LPS treatment, hADMSCs treatment had no obvious effect on microglia morphology, whereas showed significant inhibition on microglial proliferation activity (<0.05). Simultaneously, hADMSCs treatment reduced expression of microglia M1 phenotype markers (<0.05), and increased microglia M1 phenotype markers in gene levels (<0.05). At the same time, protein expression levels of TRIF, TLR4, phosphorylated interferon regulatory factor 3 (P-IRF3) and interferon regulatory factor 3 (IRF3) in BV-2 microglia were decreased after hADMSCs treatment.

CONCLUSION

hADMSCs can blockade the LPS-induced pro-inflammatory microglia M1 phenotype, whereas induces protective microglial M2 phenotype, which may be related to inhibition of the TLR4-TRIF signaling pathway.