Objective  To study the expression and secretion of alternative complement pathway regulator complement factor H (CFH) in spontaneously produced or induced human embryonic stem cell-derived retinal pigment epithelium (hESC-RPE).

  Methods  RPE cells were acquired by spontaneous differentiation from hESC (sdRPE), a source of hESC-RPE, according to the method used in clinical trials. RPE cells were also acquired under the induction of growth factors and small molecules for 14 d (iRPE). Acquired cells were kept culturing for 3 month for maturation. All differentiated cells（P3）were cultivated for 4-5 weeks prior to characterization with qRT-PCR and immunofluorescence. Secretion levels of CFH were investigated by ELISA. ARPE-19 cell line was served as control.

  Results  Both sdRPE and iRPE showed high similarity in cell morphology and the pattern of specific gene expression with human RPE. The relative CFH mRNA expression levels of both sdRPE and iRPE were significantly higher than that of ARPE-19 (P<0.05). The CFH secretion levels of sdRPE in the 24 h-, 48 h- and 72 h-culture medium were higher than those of iRPE (P=0.000 2); and this CFH secretion levels of both sdRPE and iRPE were higher than that of the ARPE-19 cell line (P<0.000 1).

  Conclusion  Both sdRPE and iRPE derived by different differentiation methods expressed and secreted CFH, suggesting that hESC-RPE may have certain ability to regulate the alternative complement pathway.