title: Amniotic fluid promotes the appearance of neural retinal progenitors and neurons in human RPE cell cultures.
abstract: OBJECTIVE
  Retinal pigment epithelial (RPE) cells are capable of differentiating into retinal neurons when induced by the appropriate growth factors. Amniotic fluid contains a variety of growth factors that are crucial for the development of a fetus. In this study, the effects of human amniotic fluid (HAF) on primary RPE cell cultures were evaluated.
  
  
  METHODS
  RPE cells were isolated from the globes of postnatal human cadavers. The isolated cells were plated and grown in DMEM/F12 with 10% fetal bovine serum. To confirm the RPE identity of the cultured cells, they were immunocytochemically examined for the presence of the RPE cell-specific marker RPE65. RPE cultures obtained from passages 2-7 were treated with HAF and examined morphologically for 1 month. To determine whether retinal neurons or progenitors developed in the treated cultures, specific markers for bipolar (protein kinase C isomer α, PKCα), amacrine (cellular retinoic acid-binding protein I, CRABPI), and neural progenitor (NESTIN) cells were sought, and the amount of mRNA was quantified using real-time PCR.
  
  
  RESULTS
  Treating RPE cells with HAF led to a significant decrease in the number of RPE65-positive cells, while PKCα- and CRABPI-positive cells were detected in the cultures. Compared with the fetal bovine serum-treated cultures, the levels of mRNAs quantitatively increased by 2-, 20- and 22-fold for NESTIN, PKCα, and CRABPI, respectively. The RPE cultures treated with HAF established spheres containing both pigmented and nonpigmented cells, which expressed neural progenitor markers such as NESTIN.
  
  
  CONCLUSIONS
  This study showed that HAF can induce RPE cells to transdifferentiate into retinal neurons and progenitor cells, and that it provides a potential source for cell-based therapies to treat retinal diseases.
authors.affiliation: National Institute of Genetic Engineering and Biotechnology, Tehran, Iran.
authors.forename: Maliheh
authors.initials: M
authors.lastname: Davari
authors.forename: Zahra-Soheila
authors.initials: ZS
authors.lastname: Soheili
authors.forename: Hamid
authors.initials: H
authors.lastname: Ahmadieh
authors.forename: Fateme
authors.initials: F
authors.lastname: Sanie-Jahromi
authors.forename: Shima
authors.initials: S
authors.lastname: Ghaderi
authors.forename: Mozhgan Rezaei
authors.initials: MR
authors.lastname: Kanavi
authors.forename: Shahram
authors.initials: S
authors.lastname: Samiei
authors.forename: Hassan
authors.initials: H
authors.lastname: Akrami
authors.forename: Massoud
authors.initials: M
authors.lastname: Haghighi
authors.forename: Fahimeh
authors.initials: F
authors.lastname: Javidi-Azad
mesh_terms: D000653:Amniotic Fluid / Q000166:cytology*; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002417:Cattle; D049109:Cell Proliferation; D048430:Cell Shape; D002478:Cells, Cultured; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D058953:Neural Stem Cells / Q000166:cytology* / Q000378:metabolism; D055351:Retinal Neurons / Q000166:cytology* / Q000378:metabolism; D055213:Retinal Pigment Epithelium / Q000166:cytology*; D018874:Spheroids, Cellular / Q000166:cytology; D015854:Up-Regulation
chemical_list: D015415:Biomarkers