RESUMO
Objective To investigate the regulation of mesenchymal stem cells (MSCs) on the expression of tumor necrosis factor-α-induced protein 8-like 2 (TNFAIP8L2, TIPE2) in the peripheral blood-derived macrophages of systemic lupus erythematosus (SLE) patients. Methods The expression of TIPE2 mRNA in peripheral blood mononuclear cells (PBMCs) and macrophages from SLE patients were detected by Quantitative polymerase chain reaction (qPCR). The TIPE2 protein levels in SLE PBMCs and peripheral blood-derived macrophages were detected by western blot, flow cytometry and immunofluorescence staining, respec-tively. Data were analyzed by t test and Spearman correlation analysis. Results The TIPE2 mRNA expres-sion in PBMCs of SLE patients was significantly lower than that of healthy controls [(0.41 ±0.14) vs (1.06±0.39), t=5.376, P<0.01], as well as the TIPE2 protein level [(0.40 ±0.21) vs (1.09 ±0.26), t=2.963, P<0.05]. The expression of TIPE2 mRNA in peripheral blood-derived macrophages from SLE patients was significantly decreased [(0.56±0.24) vs (1.07±0.38), t=5.203, P<0.01). Moreover, TIPE2 mRNA level of peripheral blood-derived macrophages was negatively correlated with systemic lupus erythematosus disease activity index (SLEDAI) score (r=-0.60, P<0.01), 24-hour urinary protein (r=-0.46, P<0.05) and erythrocyte sedimentation rate (r=-0.46, P<0.05) in SLE patients. The percentage of TIPE2+cells in peripheral blood-derived macrophages (TIPE2+/CD14+)％ from SLE patients was significantly lower than that in healthy controls [(51.4 ±18.5)％ vs (82.4 ±7.5)％, t=2.679, P<0.05]. After 24 hours co-cultured with MSCs, the TIPE2 mRNA expression in SLE per-ipheral blood-derived macrophages was significantly increased [(2.2 ±0.7) vs (1.0 ±0.3), t=3.729, P<0.05). Immunofluorescence results showed the same increase of TIPE2 protein in SLE peripheral blood-derived macrophages [(0.112 ±0.020) vs (0.074 ±0.016), t=3.268, P<0.05]. Conclusion The TIPE2 level in peripheral blood-derived macrophages of SLE patients are decreased. MSCs upregulate the TIPE2 expression in vitro, suggesting that TIPE2 can be a new target for MSCs in the treatment of SLE.