Figure 7.
Western blot analysis of tau kinases during alterations of glucose metabolism. 1, Proteins from mouse brain extracts (hippocampus plus neocortex) were separated by SDS-PAGE and identified with the following antibodies: a, GSK-3β pY216; b, GSK-3β Ser9; c, phospho-SAPK/JNK (T183/Y185, active form); d, phospho-p44/42 MAPK (T202/Y204, active form); e, cdk5; f, p35. Each lane shows an immunoblot extract from one representative mouse of four analyzed. Total GSK-3β, JNK, and MAPK were also analyzed and quantified (data not shown). A, Immunoblots from starved condition. Lane 1, Samples from fed control mice; lane 2, samples from mice starved for 3 d; lane 3, samples from mice starved for 3 d but given access to a 30% glucose solution. C, Insulin condition. Lane 1, Saline-injected control mice; lane 2, insulin-injected mice; lane 3, mice injected with a mixture of insulin and glucose. E, DG condition. Lane 1, Saline-injected control mice; lane 2, DG-injected mice; lane 3, glucose-injected mice. B, D, F, The intensities of the bands in A, C, and E were quantified and normalized to the total kinase (except for cdk5 and p35). a, GSK-3β pY216/GSK-3β; b, GSK-3β Ser9/GSK-3β; c, phospho-JNK/JNK (open columns, p46; plain columns, p54); d, phospho-MAPK/MAPK (p42 and p44 were quantified together); e, cdk5; f, p35. Data are means ± SD (n = 4 for each condition). Asterisks indicate significant differences from controls, with *p < 0.05 and **p < 0.01. Each graph displays the immunoreactivity expressed as a percentage of the control lane 1 (100%). Numbers in the graphs indicate the percentage of the line with which they are aligned.