Battersby Alysia, Jones Robert D, Lilley Kathryn S, McFarlane Ramsay J, Braig Henk R, Allen Nicholas D, Wakeman Jane A
North West Cancer Research Fund Institute, University of Wales Bangor, Deiniol Road, Bangor, Gwynedd LL57 2UW, UK.
Biochim Biophys Acta. 2007 Feb;1773(2):147-56. doi: 10.1016/j.bbamcr.2006.08.030. Epub 2006 Aug 26.
Murine embryonic stem (ES) cells can be committed to neural differentiation with high efficiency in culture through the use of feeder- and serum-free media. This system is proving to be an excellent model to study processes involved in ES cell commitment to neural cell fate. We used this approach to generate neurogenic embryoid bodies (NEBs) in a serum-free culture system to perform proteomic analysis of soluble fractions and identify early changes in protein expression as ES cells differentiate. Ten candidate proteins were altered significantly in expression levels. One of the most significant alterations was for the small heat shock protein Hsp25. Three species of Hsp25 are detected in ES cells, and this expression pattern changes during the first 24 h of differentiation until expression is decreased to levels that are barely detectable at 4 days following differentiation. We used immunofluorescence studies to confirm that following ES cell differentiation, expression of Hsp25 becomes excluded from neural precursors as well as other differentiating cells, making it a potentially useful marker of early ES cell differentiation.
