骨髓增生异常综合征患者骨髓间充质干细胞的免疫抑制作用

Immuno-suppressive effects mediated by mesenchymal stem cells of myelodysplastic syndrome patients

目的本研究通过检测骨髓增生异常综合征-难治性贫血(MDS-RA)及难治性贫血伴原始细胞增多(MDS-RAEB)患者骨髓间充质干细胞(MSC)转化生长因子(TGF-β1)、肝细胞生长因子(HGF)的表达,探讨MSC的免疫抑制作用在MDS发病中的意义。方法分离、培养23例MDS患者(MDS-RA组14例,MDS-RAEB组9例)及对照组12例的骨髓间充质干细胞,比较3组MSC的形态,采用实时定量PCR的方法检测骨髓MSC内转化生长因子(TGF-β1)、肝细胞生长因子(HGF)mRNA的表达水平;采用酶联免疫吸附测定法(ELISA)检测骨髓MSC分泌的TGF-β1、HGF的浓度。结果 3组MSC的形态无明显差异,MDS-RA组和MDS-RAEB组MSC表达和分泌TGF-β1、HGF水平明显低于对照组(P均<0.05),MDS-RA组和MDS-RAEB组MSC表达和分泌TGF-β1、HGF无明显差异(P均>0.05)。结论 MDS-RA与MDS-RAEB表达TGF-β1、HGF mRNA的水平及分泌TGF-β1、HGF的浓度水平均较正常减低,导致MSC免疫抑制能力减低,可能与MDS免疫监视低下,出现异常单克隆造血相关。

Objective To investigate expression levels of transforming growth factor- β1 （TGF-131） and hepatocyte growth factor （HGF） in mesenchymal stem cells （MSC） of myelodysplastic syndrome-refractory anemia （MDS-RA） and myelodysplastic syndrome-refractory anemia with excess blasts （ MDS-RAEB ）, and to discuss the immuno-suppres- sive effects of MSC in the pathogenesis of MDS. Methods Bone marrow samples were collected from patients with MDS at diagnosis （n =23, 14 from MDS-RA, 9 from MDS-RAEB） and 12 controls. MSCs from bone marrow sam- pies were isolated, cultured and expanded. The morphology of MSCs of the three groups was compared. The transfor- ming growth factor- β1 and hepatocyte growth factor mRNA expression levels were detected by RT-PCR, the TGF- β1 and HGF concentrations of MSCs were tested by enzyme-linked immunosorbent assay （ELISA）. Results The cultured cells from the patients with MDS presented a typical fibroblast-like morphology, which had no significant change com- pared with that of the controls. TGF- β1 and HGF mRNA expression levels and the TGF- β1 and HGF concentration lev- els in the MSCs of MDS-RA and MDS-RAEB groups were significantly lower than those of the control group （P 〈 0.05 ）. TGF- β1 and HGF mRNA expression levels and TGF- β1 and HGF concentration levels in the MSCs had no sig- nificant difference between the MDS-RA andMDS-RAEB groups （P〉0.05）. Conclusions TGF- β1 andHGFmRNA expression levels and TGF- β1 and HGF concentration levels in the MSCs of MDS-RA and MDS-RAEB groups weresignificantly lower than those of the control group, resulting in the decreasing ability of MSC immune suppression. Its mechanism may be related to lower immune surveillance and abnormal monoclonal hematopoiesis.