Benefits of bone marrow-derived mesenchymal stem cells primed with estradiol in alleviating collagen-induced arthritis

Abstract

Objectives: To investigate the effects of the oestradiol (ES) pulsed bone marrow-derived mesenchymal stem cells (BM-MSC) to treat adjuvant-induced arthritis in Wistar rats.

Materials and methods: BM-MSCs were pulsed with ES (0, 10,100, and 1000 nM) for 24 hr. RA was induced by collagen and Freund's Complete Adjuvant into the base of the tail of Wistar rats.

Results: The least effective concentration of ES that can promote potent anti-inflammatory properties in the MSC population is 100 nM. At this concentration, ES increases the inhibition of the polyclonal T lymphocyte proliferation, production of IDO, IL-10, Nitric oxide, and TGF-β, and expression of CXCR4 and CCR2 mRNA in the MSC population. Accordingly, the RA rats were treated with 2×106 MSCs or ES-pulsed MSCs (100 nM) on day 10 when all animals had developed signs of RA. ES-pulsed BM-MSCs reduced the severity of RA more profoundly than treatment with BM-MScs alone. The ability of ES-pulsed BM-MSCs to reduce symptoms and RA markers like CRP, RF, and nitric oxide was comparable to that of prednisolone. Prednisolone was more successful in reducing inflammatory cytokines than treatment with ES-pulsed BM-MSCs. ES-pulsed BM-MSCs were more successful in increasing anti-inflammatory cytokines than treatment with Prednisolone. The ability of ES-pulsed BM-MSCs to decrease the level of nitric oxide was comparable to that of prednisolone.

Conclusion: ES-pulsed BM-MSCs may be a helpful strategy in RA control.

Keywords: Estradiol; Inflammation; Mesenchymal stem cells; Rheumatoid arthritis; Wistar rat.

Figure 1

Immunophenotype evaluation of BM-MSCs. Flow cytometry analysis of BM-MSCs. BM-MSCs were negative for CD45 but positive for CD29 and CD90

Figure 2

Effect of estradiol treatment on the immunoregulatory potential of MSCs. A) Assessment of the potency of MSCs in inhibiting lymphocyte proliferation. B-E) Evaluation of immunoregulatory factors in the conditioned medium of MSCs. Values were reported as mean ±SD. Different letters indicate a significant difference between groups (P<0.05)

Figure 3

Effect of estradiol treatment on CXCR4 and CCR2 mRNA expression in MSCs. Results were presented as mean ±S.D. Different letters indicate a significant difference between groups (P<0.05)

Figure 4

Evaluation of clinical features in RA rats. A) Appearance of swelling of the limb. B) Mean of arthritis index. C) Alteration of average mean arthritis index and maximum arthritis index. The in vivo results showed that the treatment with ES-pulsed BM-MSCs or prednisolone (positive control) reduced the severity of RA more profoundly than treatment with BM-MScs alone. Data were reported as mean ±S.D. Different letters indicate a significant difference between groups (P<0.05)

Figure 5

Comparison of cytokine production in the supernatant of spleen cell culture. The weight of all animals was determined before euthanizing animals. Then, the spleens were isolated in the aseptic condition, and the spleen index was calculated for each rat. To determine the proliferation index, spleen cells were pulsed in the presence of collagen II (50 µg/ml) for 72 hr. Different letters indicate a significant difference between groups (P<0.05)

Figure 6

Evaluation of spleen index and splenic lymphocyte proliferative capacity. Spleen cells were pulsed in the presence of collagen II (50 µg/ml) for 72 hr. Then, the supernatant was collected and the production of cytokines was measured by the ELISA method. Findings were presented as mean ±SD. Different letters indicate a significant difference between groups (P<0.05)

Figure 7

Biochemical changes in the sera of RA rats. At the end of the survey, blood samples were isolated from the hearts of experimental rats under deep anesthesia. The serum samples were used to evaluate CRP, RF, nitric oxide, and myeloperoxidase. Data were reported as mean ±SD. Different letters indicate a significant difference between groups (P<0.05)