Monocyte Chemoattractant Proteins Secreted by Mesenchymal Stem Cells Regulate Macrophage Polarization

• Main Authors: Yu-Han Hung, 洪于涵
• Other Authors: Thz-Ching Chang
• Format: Others
• Language: en_US
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/h4mh4f

碩士 === 中國醫藥大學 === 臨床醫學研究所碩士班 === 105 === Mesenchymal stem cells (MSCs) have great potential in cell therapy because of their stemness, tropic factor secretion and immune modulating characteristics. M1 macrophage shifting to M2 has been considered as an important event in immune modulation. However, the paracrine effect on macrophage polarization which induced by MSCs needs to be further elucidated. In this study, MSCs were treated by inflammatory cytokines IL-1β and/or TNF-α, and 24 hours later the conditioned media (MSC CM) were collected. They were used to treat THP-1 cells, a commonly used macrophage polarization model cells that require pre-activation by PMA, and the markers of M1 and M2 were examined after at least 72-hour exposure. Results from the cytokine arrays reveal that the expressions of monocyte chemoattractant protein 1 (MCP-1) and monocyte chemoattractant protein 2 (MCP-2) are remarkably increased by incubation with inflammatory cytokines in MSCs. We have confirmed that inflammatory cytokines induce MCP-1 secretion with a dose-dependent manner by ELISA, whereas the induction of MCP-2 is not statistically significant. Also, iNOS activity suggests that no M1 polarization in MSC CM-treated THP-1 cells. Other M1/M2 markers were then examined by Western blotting, immunofluorescence and qRT-PCR. Moreover, neutralization of MCP-1 in MSC CM was tested by Western blotting and qRT-PCR in order to confirm the impact on macrophage polarization. The results of THP-1 model in these experiments were not absolute, probably indicating the transient state of M1/M2 polarization. We found that in inflammatory microenvironment cytokine secretion pattern changes in MSCs would lead to M2 macrophage polarization. This study indicates another possible pathway of immune modulation by MSCs through regulating macrophage polarization.