The effect of bone marrow stem cells on the treatment of experimental autoimmune myasthenia gravis rat

Abstract

Objective To investigate the effect of bone marrow stem cells (BMSCs) on the treatment of experimental autoimmune myasthenia gravis (EAMG) and the possible pathogenesis. Methods BMSCs were obtained from Lewis rat bone marrow selected by cell attachment, cultured and proliferated in vitro. The expression of surface molecules of CD34 and CD44 was analyzed by flow cytometry. The Lewis rats were divided randomly into group A and group B. The rats in group A were transplanted with the third passage BMSCs, and the rats in group B were injected with physiological saline. Seven days after injection, the rat model of EAMG was established by injecting mAb35 to rats in both groups. Clinical signs and symptoms were assessed with Lennon score. Western blotting method was used to determine the expression of acetylcholine receptor (AChR) protein. The CD4+CD25+ Treg cell ratio was analyzed by flow cytometry. Plasma TGF ⁃ β, IFN ⁃ γ and IL ⁃ 4 expressions were detected by ELISA. Results The clinical scores of rats treated with BMSCs were significantly lower than those untreated (t = 8.062, P = 0.000). In comparison with group B, the expression levels of AChR protein (t = 8.092, P = 0.000) and TGF⁃β (t = 9.859, P = 0.000) in group A were all higher, while IFN⁃γ (t = 9.040, P = 0.000) and IL⁃4 (t = 3.320, P = 0.004) were all lower in group A. Conclusion Transplantation with BMSCs can relieve the clinical syndrome of EAMG and reduce the lost of AChR by promoting the level of TGF⁃β, up regulating the expression of CD4+CD25+ Treg cell ratio, and suppressing IFN⁃γ and IL⁃4. DOI：10.3969/j.issn.1672⁃6731.2012.02.014