Cloning, expression and characterization of gene encoding human stem cell growth factor-alpha and its synergetic effect with rhGM-CSF on proliferation of human umbilical cord mesenchymal stem cells
人干细胞生长因子-α基因的克隆、表达及其协同rhGM-CSF对人脐带间充质干细胞的增殖作用

To investigate the effect of hSCGF-alpha on human Umbilical Cord Mesenchymal Stem Cells (hUCMSCs), we obtained hSCGF-alpha using genetic engineering, hSCGF-alpha gene was amplified from hUCMSCs cDNA using two-step PCR and was inserted into pET-28a(+) plasmid vector. Induced by IPTG at 20 degrees Celsius for 24 h, the fusion protein expressed in E. coli BL21 (DE3) was mainly existing in soluble form. The recombinant hSCGF-a was purified using NI-NTA affinity chromatography and the purity was up to 90%. The colony forming test revealed that combined use hSCGF-alpha and rmGM-CSF (recombinant murine GM-colony stimulating factor, rmGM-CSF) had granulocyte/macrophage (GM) promoting effects on murine bone marrow GM progenitor. In addition, the results indicated that hSCGF-alpha and rhGM-CSF had stimulatory effect on hUCMSCs and their synergetic effect was the strongest.