Figure 1.

(A) Hyperosmotic glucose, TNFα, or HGF treatments activate JNK1. (B) Hyperosmotic glucose, TNFα, or HGF treatments activate p70^{S6 kinase}. (C) Hyperosmotic glucose, TNFα, or HGF treatments inhibit GSK3. (D) Modulation of p42^{MAP kinase} activity after hyperosmotic glucose, TNFα, or HGF treatments. Hepatocytes were cultured as described in MATERIALS AND METHODS. After 4 h, cells were treated for the indicated times with either media control, 50 mM glucose (closed circles), 1 ng/μl TNFα (open triangles), or 1 ng/μl HGF (closed squares) at 37°C, after which time media were aspirated and the cells frozen. Hepatocytes were lysed and subjected to immunoprecipitation followed by immune complex kinase assays for the indicated protein kinase. Activities shown are expressed as cpm incorporated into substrate versus media control treatment (5000 cpm/pmol) and are the means of triplicates from a representative of four experiments. Media control treatment did not alter the basal activities of protein kinases versus no treatment.