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

Abstract 

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±5ng adenosine per 10⁵ cells during 24h in culture, compared to 11±1ng released from corresponding wild-type cells. Adenosine release was maintained after differentiation as differentiated Adk^−/− cells continued to release significantly more adenosine per 24h (47±1ng per 10⁵ cells) compared to wild-type cells (3±0.2ng per 10⁵ 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.

Keywords: Adenosine, Adenosine kinase, Neural stem cell, Neural progenitor cell, Epilepsy, Local delivery, LC–MS/MS