An experimental study on intracerebroventricular transplantation of human amniotic epithelial cells in a rat model of Parkinson's disease

Objectives: Human amniotic epithelial (HAE) cells are formed from amnioblasts, separated from the epiblast at about the eighth day after fertilization. In the present study, we attempt to investigate the effects of intracerebroventricular transplantation of HAE cells on Parkinson's disease (PD) rats. Methods: A PD rat model was induced by 6-OHDA injections. Then the rats were transplanted intracerebroventricularly with HAE cells. Apomorphin-induced turns were used to assess the neurobehavioral deficit in rats. Immunofluorescence cytochemistry was used to track the survival of HAE cells. Tyrosinehydroxylase (TH) immunohistochemistry was used to determine the density of TH-positive cells in rat substantia nigra and the differentiation of HAE cells. High performance liquid chromatography (HPLC) was used to measure the levels of dopamine (DA) and its metabolites 3, 4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in rat striatum. HVA levels in the cerebrospinal fluid of rats were also determined by HPLC. Results: The results showed that transplanted HAE cells can survive for at least 10 weeks and differentiate into TH-positive cells in PD rats. The grafts significantly ameliorated apomorphine-induced turns in PD rats. TH immunohistochemistry showed that HAE cells attenuated the loss of TH-positive cells in rat substantia nigra. In addition, HAE cells prevented the fall of DA and its metabolites DOPAC and HVA in PD rats. Increased HVA levels in the cerebrospinal fluid of PD rats were also observed. Conclusion: These results demonstrate that HAE cells have beneficial effect on 6-OHDA-induced PD rats, which may be due to the neurotrophic factors secrete by HAE cells.