Human Amniotic Fluid‐Derived Stem Cells: A Novel Source of Dopaminergic Neurons?

Abstract

The aim of our study is to investigate whether human amniotic fluid derived stem cells (hAFSC) can be used for regenerative applications in neurodegenerative diseases like Parkinson's disease (PD).To yield dopaminergic cells, hAFSC were cultured in a 2 stage culture media systems that include growth factors to mimic the normal midbrain dopaminergic development. At different time points during differentiation differentiated cells were analyzed using RT‐PCR and immunostaining. At the end of differentiation the amount of cellular dopamine quantified and a whole‐cell voltage clamp recording was performed.The hAFSC at end of the expansion phase expressed nestin and Nurr1 and their expression was enhanced by exposure to hypoxic culture condition. At the end of terminal differentiation, cells look bipolar and pyramidal and showed expression of Girk2. After recording the inward currents, barium was added to the bath to block the Girk‐specific inward current. A reduction in the amplitude of the currents evoked by the same hyperpolarizing voltage step protocol in the presence of barium indicated the presence of Girk‐mediated potassium channel. Terminally differentiated cells secreted dopamine in a dose response manner, yielding approximately 2nM/100,000 cells.In this study we showed that hAFSC can be successfully differentiated into dopamine secreting neuron‐like cells that express neuronal genes.