Tyrosine kinases are required for IFN-gamma-induced growth of human embryonic forebrain astrocytes

THE cytokine IFN-gamma was shown to regulate growth and differentiation of human embryonic forebrain astrocytes. This work investigated a signalling p athway used by IFN-gamma during the process of growth regulation of human f etal astrocytes obtained from first trimester embryos. IFN-gamma induced si gnificantly higher cell survival compared to that of unexposed cultures, an d this survival could be suppressed by incubation with the tyrosine protein kinase (TPK) specific inhibitor tyrphostin A47 at the non-toxic concentrat ion of 10(-6) M. The signal transducer and activator of transcription (STAT )-1 was translocated into the nucleus upon IFN-gamma stimulation, which was also blocked by incubation with A47. Our data demonstrate that TPKs are ac tively involved in growth regulation of the developing brain astrocytes ind uced by IFN-gamma. (C) 1998 Lippincott Williams & Wilkins.