Umbilical cord mesenchymal stem cell transplantation modulated Th17/Treg balance and delayed lupus progression in MRL/lpr mice / 中华风湿病学杂志

ABSTRACT

Objective To explore the preventive effect of early umbilical cord mesenchymal stem cells (UC-MSCs) transplantation on MRL/lpr mice and the underly mechanisms.Methods Fourteen 10-week-old MRL/lpr mice were labeled and numbered.They were randomly divided into 2 groups by using random number table and injected with 1 ×106 UC-MSCs or PBS via tail vein respectively.Proteinuria was measured with Bradford method every 4 weeks.All mice were sacrificed at the age of 28 weeks, with the level of serum antidsDNA antibody and IL-17 detected by enzyme linked immunosorbent assay (ELISA).Splenic Th17 cells, as well as regulatory T cells (Treg) were examined by flow cytometry.Data were analyzed with t test and Pearson's correlation test.Results The onset of proteinuria was delayed for 4 weeks in UC-MSC-treated group compared with that in the control group.At the age of 28 weeks, the 24 hour proteinuria [(1.78±0.17) mg vs (4.77±0.98)mg, t=2.99, P＜0.05] and the spleen weight [(0.149±0.009) g vs (0.273±0.052) g, t=2.33, P＜0.05] in UC-MSCtreated group were significantly lower than those in the control group.There was also a trend of the decline of serum anti-dsDNA antibody and IL-17 level after UC-MSCs transplantation.Compared with those in the control group, both the percentage and the absolute number of Th17 cells were significantly decreased in UC-MSC-treated group [(0.90±0.19)％ vs (2.81±0.50)％, t=3.54, P＜0.01 and (3.7±0.8)×105 vs (19.3±3.7)×105, t=4.12,P＜0.01].Meanwhile, the percentage of Treg elevated after UC-MSCs treatment.The ratio of Th17/Treg was significantly lower in UC-MSC-treated group than that in the control group (0.11±0.03 vs 0.50±0.09, t=4.23,P＜0.01).Both the ratio of Th17/Treg (r=0.73, P＜0.01;r=0.59, P＜0.05) and serum IL-17 level (r=0.78, P＜0.01;r=0.56, P＜0.05) was positively correlated with the level of 24 hour proteinuria and anti-dsDNA antibody respectively in MRL/lpr mice.Conclusion Early UC-MSCs transplantation helps to delay disease onset and ameliorate disease progression in MRL/lpr mice, which may act through the modulation of Th17/Treg balance.