Integrin-mediated dendrite branch maintenance requires Abelson (Abl) family kinases - PubMed (original) (raw)

Arg is required for integrin-mediated neurite branching. Bar diagrams indicate mean branchpoint number (A, C, E) and total neurite arbor length (B, D, F). All values represent mean ± SE. A, B, Wild-type or arg_-/_- cortical neurons were plated on glass coverslips coated with polyornithine (ornithine) or polyornithine plus laminin-1 (laminin). Neurons were fixed at 24 h and traced with camera lucida software. Wild type on ornithine, n = 150 total neurons, five independent experiments; wild type on laminin, n = 136 neurons, five experiments; arg_-/_- on ornithine, n = 137 neurons, five experiments; arg_-/_- on laminin, n = 128 neurons, five experiments. C, D, Wild-type or arg_-/_- cortical neurons plated on ornithine or laminin in the presence of the Abl/Arg inhibitor STI571 (3.3 μ

) or the β1/β3 integrin inhibitor echistatin (1 μ

). Wild-type on ornithine plus echistatin, n = 61 neurons, three experiments; wild type on laminin plus echistatin, n = 59 neurons, three experiments, wild type on ornithine plus STI571, n = 61 neurons, three experiments; wild type on laminin plus STI571, n = 93 neurons, three experiments; arg_-/_- on ornithine plus echistatin, n = 20, one experiment; arg_-/_- on laminin plus echistatin, n = 59 neurons, three experiments; arg_-/_- on ornithine plus STI571, n = 57 neurons, three experiments; arg_-/_- on laminin plus STI571, n = 89 neurons, three experiments. For A-D, ANOVA between all plating conditions: branchpoints, p < 0.0001; length, p < 0.0001; post hoc Student-Newman-Keuls test for each condition versus wild type plated on ornithine, *p < 0.05. ANOVA between all plating conditions for each genotype: wild-type branchpoints, p < 0.0001; arg_-/_- branchpoints, p = 0.119; wild-type length, p < 0.0001; arg_-/_- length, p = 0.022. E, F, Wild type or arg_-/_- cortical neurons plated on Semaphorin7A (AP-Sema7A) or control protein (AP) substrates in the presence of STI571 (3.3 μ

) or echistatin (1 μ

). Wild type on AP, n = 70 neurons, four experiments; wild type on 20 n

Sema7A, n = 46 neurons, two experiments; wild type on 100 n

Sema7A, n = 72 neurons, three experiments; wild type on 100 n

Sema7A plus STI571, n = 27 neurons, one experiment; wild type on 100 n

Sema7A plus echistatin, n = 25 neurons, one experiment; arg_-/_- on AP, n = 74 neurons, three experiments; arg_-/_- on 20 n

Sema7A, n = 47 neurons, two experiments; arg_-/_- on 100 n

Sema7A, n = 72 neurons, three experiments; arg_-/_- on 100 n

Sema7A plus STI571, n = 25 neurons, one experiment; arg_-/_- on 100 n

Sema7A plus echistatin, n = 29 neurons, one experiment. For E and F, ANOVA between all plating conditions is as follows: branchpoints, p < 0.0001; length, p < 0.0001; post hoc Student-Newman-Keuls test for each condition versus wild type plated on 100 n

AP, *p < 0.05. ANOVA between all plating conditions for each genotype: wild-type branchpoints, p = 0.0004; arg_-/_- branchpoints, p = 0.015; wild-type length, p = 0.007; arg_-/_- length, p = 0.104. G, H, Wild type or arg_-/_- cortical neurons plated on ornithine (orni), laminin (lamin), or Netrin-1 (netrin) at the indicated concentrations. Neurons were fixed at 24 h. One experiment was performed for each condition. Wild-type neurons on ornithine, n = 20 neurons; wild type on laminin, n = 22 neurons; wild type on 5 μg/ml netrin, n = 25 neurons; wild type on 10 μg/ml netrin, n = 24 neurons; arg_-/_- neurons on ornithine, n = 24 neurons; arg_-/_- on laminin, n = 19 neurons; arg_-/_- on 5 μg/ml netrin, n = 24 neurons; arg_-/_- on 10 μg/ml netrin, n = 27 neurons. ANOVA between all plating conditions is as follows: branchpoints, p < 0.0001, length, p < 0.0001; post hoc Student-Newman-Keuls test for each condition versus wild type plated on ornithine, *p < 0.05. ANOVA between all plating conditions for each genotype: wild-type branchpoints, p = 0 < 0.0001; arg_-/_- branchpoints, p = 0.772; wild-type length, p < 0.0001; arg_-/_- length, p = 0.257.