Astrocytes derived from fetal neural progenitor cells as a novel source for therapeutic adenosine delivery

Purpose: Intracerebral delivery of anti-epileptic compounds represents a novel strategy for the treatment of refractory epilepsy. Adenosine is a possible candidate for local delivery based on its proven anti-epileptic effects. Neural stem cells constitute an ideal cell source for intracerebral transplantation and long-term drug delivery. In order to develop a cell-based system for the long-term delivery of adenosine, we isolated neural progenitor cells from adenosine kinase deficient mice (Adk(-/-)) and compared their differentiation potential and adenosine release properties with corresponding wild-type cells.
Methods: Fetal neural progenitor cells were isolated from the brains of Adk(-/-) and C57BL/6 mice fetuses and expanded in vitro. Before and after neural differentiation, supernatants were collected and assayed for adenosine release using liquid chromatography-tandem mass spectrometry (LC-MS/MS).
Results: Adk(-/-) cells secreted significantly more adenosine compared to wild-type cells at any time point of differentiation. Undifferentiated Adk(-/-) cells secreted 137 +/- 5 ng adenosine per 10(5) cells during 24 h in culture, compared to 11 +/- 1 ng released from corresponding wild-type cells. Adenosine release was maintained after differentiation as differentiated Adk(-/-) cells continued to release significantly more adenosine per 24 h (47 +/- 1 ng per 10(5) cells) compared to wild-type cells (3 +/- 0.2 ng per 10(5) cells).
Conclusions: Fetal neural progenitor cells isolated from Adk(-/-) mice - but not those from C57BL/6 mice release amounts of adenosine considered to be of therapeutic relevance.