Signaling effects of α-thrombin and SFLLRN in rat glioma C6 cells

Effects of thrombin on brain cells, including change of neurite outgrowth and astrocyte shape, are described, but the molecular mechanisms are unclear. We investigated the effects of human α-thrombin and a six amino acid thrombin receptor activating peptide (TRAP-6, SFLLRN) on [Ca²⁺]₁, phosphoinositide hydrolysis, and protein kinase C in rat glioma C₆ cells. Stimulation of C₆ cells with both α-thrombin and TRAP-6 resulted in [Ca²⁺]₁ mobilization, [³H]Inositol phosphate response, and enhanced immunoreactivity of the protein kinase C (PKC) isoenzymes α, β, γ, δ, and ϵ. Results suggest that α-thrombin and TRAP-6 activate at least partially the same intracellular signaling pathways in rat glioma C₆ cells, which is evidence for involvement of “tethered ligand” receptor in thrombin induced signaling in glioma C₆ cells. © 1996 Wiley-Liss, Inc.