Objective To investigate how human umbilical cord mesenchymal stem cells (MSCs) in vitro regulate the miRNA profile of activated peripheral blood CD4+T cells from patient with primary Sj?gren's syndrome (pSS). Methods Peripheral blood CD4+T cells from patient with pSS were sorted and divided into healthy naive group, pSS naive group, pSS activated group, MSC treatment group and MSC (pre-stimulated by IFN-γ) treatment group. CD4+ T cells were counted. MiRNA microarray technology was used to detect the expression profile of CD4+T cells, and the expression of miRNA125b and miRNA155 was verified by real time quantification-polymerase chain reaction (RT-PCR). Mean in groups were compared using ANOVA, and multiple comparisons were used with LSD method. Results Both MSCs and IFN-γ-MSCs could inhibit the proliferation of activated CD4+ T cells in a MSC-dependent manner, but there was no significant difference between two groups. Microarray analysis found that the differentially enriched miRNAs in pSS na?ve (vs healthy na?ve), pSS activation (vs pSS na?ve), MSC treatment (vs pSS activation) and pre-IFN-γ MSC treatment (vs pSS activation) were 42 miRNAs, 56 miRNAs, 21 miRNAs and 24 miRNAs, respectively. Furthermore, the expressions of miRNA125b and miRNA155 were verified by RT-PCR and found that miRNA125b relative level in 5 groups was 1.02 ±0.13, 0.80 ±0.11, 0.44 ±0.17, 0.76 ±0.17 and 0.81 ±0.15 (F=18.32, P<0.01), and miRNA155 was 1.5 ±0.8, 3.9 ±1.3, 8.4 ±2.6, 10.1 ±4.2 and 11.2 ±5.0 (F=26.65, P<0.01). Conclusion MSCs can regulate miRNA profile of activated CD4+ T cells in peripheral blood of patient with pSS, and partially reverse down-regulated miR-125b in activated CD4+T cells, which may play a regulatory role in inhibiting the activation of CD4+T cells by MSCs.

Objective To investigate the suppressive effect of prostaglandin E2 (PGE2),hepatocyte growth factor (HGF) and indoleamine 2,3-dioxygenase (IDO) whose secretion was promoted by human umbilical cord mesenchymal stem cells(MSCs) on the activated peripheral blood CD4+ T cells in primary Sj(o)gren syndrome (pSS) in vitro.Methods Primary cultured umbilical cord MSCs were identified by flow cytometry,and peripheral blood CD4+ T cells were sorted in pSS patients.CD4+ T cells were cultured with CD3,CD28 antibody for 72 h to be the activated(control group);the activated CD4+ T cells were co-cultured with MSCs for 72 h(MSCs group) or MSCs were pre-stimulated with interferon-γ (IFN-γ),then the activated CD4+ T cells were co-cultured with pre-stimulated MSCs for 72 h (pre-stimulated group).The suspension of CD4+ T cells were collected and counted.PGE2,HGF and IDO in the supernatants were detected by ELISA.Mean in groups were compared using ANOVA,and multiple comparisons were used with LSD method.Results The concentrations of PGE2 in the supernataut of the control group,MSCs group and pre-stimulated group were (111 ±4) pg/ml,(2 814±6) pg/ml and (2 716±8) pg/ml (F=167 292.12,P＜0.01) respectively.The concentrations of HGF in the above groups were (597±9) pg/ml,(383±9) pg/ml and (727±12) pg/ml(F=878.61,P＜0.01) respectively.The concentrations of IDO in the above groups were (143±4) pg/ml,(835±5) pg/ml and (588±3) pg/ml (F=21 104.41,P＜0.01) respectively.Compared with the control group,levels of PGE2 significantly increased in the MSCs group and the pre-stimulated group that CD4+ T cells were co-cultured with MSCs (t=509.88,P＜0.01 and t=491.48,P＜0.01),and levels of IDO also significantly increased (t=202.69,P＜0.01 and t=130.39,P＜0.01),while the activation and proliferation of CD4+T cells were inhibited (t=-16.20,P＜0.01 and t=-31.48,P＜0.01).Compared with MSCs group,levels of PGE2 and IDO significantly decreased in pre-stimulated group (t=-18.40,P＜0.01 and t=-72.30,P＜0.01),and levels of HGF significantly increased in pre-stimulated group(t=41.51,P＜0.01),while the activation and proliferation of CD4+ T cells were further inhibited (t=-15.28,P＜0.01).Conclusion MSCs can inhibit the activation and proliferation of CD4+ T cells in pSS in vitro.The suppressive effect of MSCs may be achieved by promoting secretion of cytokines such as PGE2,HGF and IDO.HGF plays a more important role in the suppressive effect of MSCs pre-stimulated with IFN-γ.Too much PGE2 or IDO propably results in negative feedback regulation of MSCs.