Figure 8. The neural-specific markers were upregulated in human amniotic fluid (HAF)–treated retinal pigment epithelium (RPE) cultures. Bar graphs showing the relative gene expression value of the NESTIN, protein kinase C isomer α (PKCα), cellular retinoic acid-binding protein I (CRABPI), CRABPII, pigment epithelium-derived factor (PEDF), and vascular endothelial growth factor (VEGF) genes in RPE cultures treated with 10%, 20%, or 30% (v/v) HAF with respect to 10% (v/v) fetal bovine serum (FBS). The total RNA was isolated, and the relative gene expression for each of the specific markers was analyzed with real-time PCR. The increased expression of NESTIN and PKCα in cells treated with 30% HAF (v/v) was significant (2- and 20-fold,respectively). For CRABPI, the same level of expression (approximately 22-fold) was found in cells treated with either 10% or 30% HAF (v/v). For the CRABPII, PEDF, and VEGF genes, the levels of mRNA expression were enhanced in cells treated with 10% HAF (v/v; 7.5-, 5.5- and 2.7-fold, respectively), though it decreased with increasing concentrations of HAF. The experiment was repeated twice, with each repetition executed in duplicate.