Protection of Nerve Injury with Exosome Extracted from Mesenchymal Stem Cell / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the protective effect of Exosomes from human adipose-derived mesenchymal stem cells (hAMSCs) in neural injury induced by glutamate and its possible mechanism.</p><p><b>METHODS</b>Characteristics of Exosomes from hAMSCs were identified by electron microscopy and Western blot analysis. Cytokines that might play a major role in the protective effect were tested by enzyme-linked immunosorbent assay (ELISA). The protective action of Exosome and its possible signaling pathway were researched by the in vitro neural injury induced by glutamate, including control group (without Glu), Glu group (dealing with Glu), Glu+Exo group (dealing with Glu +100 ng/ml Exo), Glu+Exo+Akt group (dealing with Glu+100 ng/ml Exo+10 μmol/L Akt), Glu+Exo+Erk group (dealing with 100 ng/ml Glu+100 ng/ml Exo+10 μmol/L Erk), and Glu+Exo+TrkB group (dealing with Glu+100 ng/ml Exo +10 μmol/L TrkB).</p><p><b>RESULTS</b>Exosomes from hAMSCs had similar sizes to those isolated from other kinds of cells, and expressed the characteristic proteins such as CD63, CD81, HSP70, and HSP90. Cytokines that had neurotrophic effects on Exosomes were mainly insulin-like growth factor and hepatocyte growth factor, with the concentration being 9336.49±258.63 and 58,645.50±16,014.62, respectively; brain derived neurotrophic factor, nerve growth factor,and vascular endothelial growth factor had lower levels, with the concentration being 1928.25±385.47, 1136.94±5.99, and 33.34±9.43, respectively. MTS assay showed that the PC12 cell survival rates were 0.842±0.047, 0.306±0.024, 0.566±0.026, 0.461±0.016, 0.497±0.003, and 0.515±0.034 in the control group, Glu group, Glu+Exo group, Glu+Exo+Akt group, Glu+Exo+Erk group, and Glu+Exo+TrkB group; obviously, it was significantly lower in Glu group than in control group (P=0.02), significantly higher in Glu+Exo group than in Glu group (P=0.01), and significantly lower in Glu+Exo+Akt group than in Glu+Exo group (P=0.01).</p><p><b>CONCLUSION</b>Exosomes secreted from hAMSCs have protective effect against neuron damage induced by glutamate, which may be mediated through activating the PI3/K-Akt signalling pathway.</p>

Application and curative effect of plasma exchange in myasthenia gravis patients with thymectomy / 中南大学学报(医学版)

OBJECTIVE@#To explore the application of plasma exchange in myasthenia gravis (MG) patients with thymectomy, and to evaluate its curative effects.@*METHODS@#The clinical data of 50 patients with thymectomy were analyzed retrospectively, and the patients were divided into Group A (23 cases, undergoing thymectomy and plasma exchange) and Group B (27 cases, undergoing thymectomy). The difference of serum concentration of AChRab was examined by ELISA, and the time of auxiliary breath, crisis of myasthenia and clinical evaluation in the 2 groups were compared.@*RESULTS@#Serum concentration of AChRab in Group A descended obviously after the plasma exchange. One day and one week after the operation, the AChRab concentration in Group A was obviously lower than that in Group B, but there was no difference one month after the operation. One week after the operation, the time of auxiliary breath,crisis of myasthenia and clinical evaluation in Group A were less than those in Group B.@*CONCLUSION@#Plasma exchange together with thymectomy can improve the temporary curative effects in patients with MG. It is safe and effective for MG.