title: Growth conditions differentially affect the constitutive expression of primary response genes in cultured cerebellar granule cells.
abstract: Cultured cerebellar granule cells underwent apoptotic degeneration when grown in medium containing 10 instead of 25 mM K+. Knowing that apoptosis is associated with changes in the expression of primary response genes, we have measured c-fos, zif/268, and c-jun mRNA levels during maturation of cultured granule cells grown in 10 or 25 mM K+. The constitutive expression of c-fos and zif/268 was differentially regulated by extracellular K+ concentration at 5 days of maturation in vitro (DIV), when cells grown under suboptimal conditions (i.e. in 10 mM K+) are committed to degenerate. At this stage, c-fos mRNA levels were detectable only in cultures grown in 25 mM K+, whereas zif/268 mRNA levels were dramatically elevated in cultures grown in 10 mM K+. This provides one of the few conditions in which c-fos and zif/268 are differentially regulated in nerve cells. Substantial changes in c-jun, or beta-actin mRNA levels were detectable only at 7 DIV, when the percentage of apoptotic cells had already reached a plateau in cultures grown in 10 mM K+. We speculate that changes in the expression of zif/268 are important in the gene program associated with the induction of apoptosis by trophic deprivation in cultured neurons.
authors.affiliation: Institute of Pharmacology, School of Medicine, University of Catania, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Copani
authors.forename: V
authors.initials: V
authors.lastname: Bruno
authors.forename: P
authors.initials: P
authors.lastname: Dell'Albani
authors.forename: G
authors.initials: G
authors.lastname: Battaglia
authors.forename: V
authors.initials: V
authors.lastname: Barresi
authors.forename: A
authors.initials: A
authors.lastname: Caruso
authors.forename: F
authors.initials: F
authors.lastname: Nicoletti
authors.forename: D F
authors.initials: DF
authors.lastname: Condorelli
mesh_terms: D000818:Animals; D002455:Cell Division / Q000235:genetics; D002478:Cells, Cultured; D002531:Cerebellum / Q000166:cytology / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D017781:Genes, Immediate-Early; D016762:Genes, fos; D051381:Rats