Effects of MSCs on the progression of atherosclerosis plaque in ApoE-knockout miceA

Background Immune inflammatory response is throughout the entire process of atherosclerosis （AS）. It was unclear whether the mechanism of mesenchymal stem cells （MSCs） transplantation for treatment of AS is involved with inflammation regulation in the plaque area. The aim of this study was to explore the effects of MSCs in the formation of atherosclerosis plaque in hypercholesterolemic apoliprotein （apo）E-/- mice. Methods ApoE-/- mice MSCs were isolated and identified. At 8 weeks of age, 30 male ApoE-/- mice were randomly divided into negative control group （Neg, n = 10）, positive control group （Pos, n = 10） and mesenchymal stem cells group （MSCs, n = 10）. MSCs were injected through caudal vein into the body of Pos and MSCs group. The plaque area of all subjects were compared, the percentage of CD4^＋CD25^＋Tregs in different tissues were analyzed by fluorescence activated cell sorter （FACS）, proliferation response of splenocytes to MSCs was detected and cytokines in the supernatant were determined by enzyme linked immunosorbent assay （ELISA）. Results Compared with controls, MSCs resulted in a significant decrease of latherosclerotic plaques size （P 〈 0.05）, and a significant increase of CD4^＋CD25^＋ regulatory T cells in spleen （P 〈 0.05）. Specific proliferation response of CD4^＋CD25^＋ regulatory T cells in splenocytes to MCSs was significantly suppressed, the superanant level of TGF-[3 and IL-10 in MSCs group were increased while IFN-γ/ decreased significantly. Conclusion MSCs play an important role in regulating the inflammatory response and significantly inhibit the formation of the atherosclerosis plaque in ApoE-/-mice.