Expression of pyruvate kinase in astrocytes induced to differentiate in vitro

✍ Scribed by Dr. J. L. Ngo; K. H. Ibsen

• Book ID: 102909491
• Publisher: John Wiley and Sons
• Year: 1989
• Tongue: English
• Weight: 751 KB
• Volume: 23
• Category: Article
• ISSN: 0360-4012
• DOI: 10.1002/jnr.490230109

✦ Synopsis

Astrocytes maintained in a chemically defined media undergo differentiation and a parallel increase in pyruvate kinase specific activity. These changes are accompanied by a shift in the isoelectrofocusing pattern, but not by expression of pyruvate kinase Mq, the characteristic adult rat brain isozyme. Thus, this chemically defined media lacks a substance required to induce pyruvate kinase M synthesis and this function can be uncoupled from other aspects of cellular differentiation. The uncoupling of pyruvate kinase maturation from cellular differentiation and the observation of only a single, 2.3 kilobase, pyruvate kinase mRNA molecule at different stages of the postnatal development of rat brain support the concept that the Kto M-isoform transformation is a posttranscriptional event.

The effect of the individual components of this chemically defined medium on pyruvate kinase specific activity was studied by eliminating one component at a time. The increase in activity was found to be completely dependent upon fibroblastic growth factor and prostaglandin Fzor and was partially dependent on the simultaneous presence of insulin.