Fig 1: Co‐culturing of macrophages/MEFs and BM‐MSCs. A, Schematic diagram of macrophages directly (left) or transwell (right) co‐cultured with murine embryonic fibroblasts (MEFs)/BM‐MSCs. In the direct co‐culturing system, macrophages were directly contacted with BM‐MSCs/MEFs. In the transwell system, macrophages were cultured in the lower compartment, while BM‐MSCs/MEFs were cultured in the upper compartment. Only soluble factors secreted by BM‐MSCs/MEFs could penetrate the membrane between upper and lower compartment and contacted with macrophages cultured in the lower compartment. Direct contacts between macrophages and BM‐MSCs/MEFs were prevented in the transwell system. B, ELISA was applied to evaluate the content of pro‐inflammation factors (IL‐6, IL‐1β) and anti‐inflammation factors IL‐10 in the supernatant of direct co‐culturing of macrophages with MEFs, transwell co‐culturing macrophages with MEFs, direct co‐culturing macrophages with BM‐MSCs, transwell co‐culturing macrophages with MSCs. IL‐6 were decreased in both direct MSC group and transwell BM‐MSCs group comparing with direct MEFs and transwell MEFs. IL‐1β was significantly decreased in both direct BM‐MSCs group and transwell BM‐MSCs group comparing with direct MEFs and transwell MEFs. On the contrary, IL‐10 was increased in both direct BM‐MSCs and transwell BM‐MSCs group (light grey column) comparing with direct MEFs and transwell MEFs. C, Real‐time PCR was performed to determine the expression of M2 macrophage markers (CD206, Arg1, Fizz1 and Ym1) expressions in direct co‐culturing of macrophages with MEFs, transwell co‐culturing macrophages with MEFs, direct co‐culturing macrophages with BM‐MSCs, transwell co‐culturing macrophages with BM‐MSCs. Expressions of CD206, Arg1, Fizz1 and Ym1 were all increased in both direct BM‐MSCs group and transwell BM‐MSCs group (light grey column) comparing with direct MEFs and transwell MEFs group. D, Western blotting was utilized to analyse CD206 and Arg1 protein expression in direct co‐culturing of macrophages with MEFs), transwell co‐culturing macrophages with MEFs (transwell MEFs), direct co‐culturing macrophages with BM‐MSCs (direct MSCs), transwell co‐culturing macrophages with BM‐MSCs (transwell MSCs). Relative protein levels of CD206 and Arg1 were both determined by normalized with β‐actin expression. CD206 expression and Arg1 expression were increased in both direct BM‐MSCs and transwell BM‐MSCs group comparing with direct MEFs and transwell MEF group