Protein kinase C activation and down-regulation in relation to phorbol ester-induced differentiation of SH-SY5Y human neuroblastoma cells

✍ Scribed by Jari E. Heikkilä; Göran Åkerlind; Karl E. O. Åkerman

• Publisher: John Wiley and Sons
• Year: 1989
• Tongue: English
• Weight: 933 KB
• Volume: 140
• Category: Article
• ISSN: 0021-9541
• DOI: 10.1002/jcp.1041400326

✦ Synopsis

The role of protein kinase C activation in changes in muscarinic receptor functions and in the appearance of biochemical properties characteristic of neuronal cells was studied in SH-SY5Y human neuroblastoma cells induced to differentiate with the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPAj. A decrease in muscarinic receptor sensitivity with respect to agonist induced Ca2 + mobilization and receptor number parallelled the increase in membrane-associated protein kinase C (PK-C) activity. These changes occurred during the first 6 h of culture, and they were associated with rounding-up of cells. A subsequent decrease in particulate PK-C activity was followed by an increase in noradrenaline content, the appearance of an electrically excitable membrane, and an increase in the level of neuron-specific enolase. These changes were accompanied by a pronounced neurite outgrowth. 1 -(5-lsoquinolinesulphonyl)-2-methylpiperazine (H-7), an inhibitor of PK-C and cyclic nucleotide-dependent protein kinases, enhanced the morphological differentiation induced by TPA, whereas N-(2-guanidinoethylj-5-isoquinolinesulphonamide (HA-1 004), which primarily inhibits cyclic nucleotide-dependent protein kinases, had no effect on the TPAinduced phenotypic differentiation. H-7 inhibited the decrease in muscarinic receptor sensitivity and receptor number, but had no effect on the appearance of the electrically excitable membrane or on the increase in the neuron-specific enolase level. Both H-7 and HA-1004 inhibited the TPA-induced increase in noradrenaline content.