Transient expression and biological activity identification of human pigment epithelium-derived factor in mammary cell line SP2/0 / 中华围产医学杂志

ABSTRACT

Objective To construct eukaryotic expression plasmid pIRESneo3-pigment epithelium-derived factor (PEDF) and detect its transient expression in SP2/0 cells. Methods Specific primers were designed based on the mature peptide sequence of human PEDF cDNA in the GenBank. Human PEDF gene was cloned into the eukaryotic expression vector pIRESneo3. The PEDF DNA was transfected into SP2/0 with LipofectamineTM 2000. The recombinant human PEDF protein expressed in SP2/0 cell culture supernatant was identified by Western blot and enzyme-linked immunosorbent assay. The biological activity of the recombinant human PEDF was measured by 3-(4,5-dimethylthiazol-z-y1)-2,5-diphenytetrazolium bromide(MTT) method. Results PCR amplification, restriction enzyme digestion and DNA sequencing confirmed that the mature peptide sequence of human PEDF cDNA was successfully cloned into the eukaryotic expression vector pIRESneo3. And the plasmid was transfected into SP2/0 cells, which could secret PEDF. Western blot analysis showed that there was only one obvious band at the position of relative molecular weight of 50 000, and it is equivalent to the expected value. Enzyme-linked immunosorbent assay suggested that the content of PEDF began to rise after transfection, and peaked at 36 h [(0.92±0.04) μg/ml]. The proliferation of human umbilical vein endothelial cell line was significantly inhibited by supernatant after transfection of 36 h (P<0.05). Conclusions The eukaryotic expression plasmid pIRESneo3-PEDF had been successfully constructed and active human PEDF was transiently secreted, which made a foundation for further study of stable expression and purification of PEDF. This protein could be a potential medication for preventing and managing retinopathy of prematurity.