[Immunomodulatory mechanism of umbilical cord mesenchymal stem cells modified by miR-125b-5p in systemic lupus erythematosus].

OBJECTIVE

To investigate the mechanism of immunomodulatory effects of umbilical cord mesenchymal stem cells (UC-MSCs) modified by miR-125b-5p on systemic lupus erythematosus (SLE).

METHODS

The expression level of miR-125b-5p was detected by real-time fluorescence quantitative PCR in UC-MSCs and peripheral blood mononuclear cells (PBMCs) from SLE patients and health checkers. Annexin V-FITC/PI apoptosis detection kit was used to detect the effect of miR-125b-5p on apoptosis of UC-MSCs. MRL/lpr mice in each group were injected with UC-MSCs tail vein, and T-lymphocyte subsets in the spleen of the MRL/lpr mice were detected by flow cytometry after 5 weeks. The expression levels of interleukin (IL)-4 and IL-17A in serum of MRL/lpr mice were detected by ELISA. Hematoxylin-eosin staining was used to observe the pathological manifestations of the lungs and kidneys of the MRL/lpr mice.

RESULTS

miR-125b-5p was significantly down-regulated in PBMCs of SLE patients compared with healthy controls ( < 0.01). Compared with the UC-MSCs group, the expression of miR- 125b-5p in UC-MSCs modified by miR-125b-5p group was increased ( < 0.01). The survival rate of UC-MSCs was significantly increased by miR-125b-5p ( < 0.01). Compared with the untreated group of MRL/lpr mice, the expression level of IL-4 in serum was increased ( < 0.05); the expression level of IL-17A was decreased ( < 0.05); the proportion of Th17 cells in the spleen of MRL/lpr mice was decreased ( < 0.05); the inflammatory cells infiltration and micro-thrombosis of lungs and kidneys of MRL/lpr mice were significantly reduced in the UC-MSCs modified by miR-125b-5p treatment group.

CONCLUSION

UC-MSCs modified by miR-125b-5p have immunomodulatory effects on systemic lupus erythematosus.