Figure 4
From: IGFBPL1 Regulates Axon Growth through IGF-1-mediated Signaling Cascades
Function of IGF-1/IGF-1R signaling for IGFBPL1-mediated growth. (A) Co-IP of recombinant IGFBPL1 and IGF-1 proteins ex vivo. Anti-IGFBPL1 detected the presence of IGF-1 in the co-IP product and vice versa, anti-IGF-1 detected the presence of IGFBPL1 in the protein complex. (B) Co-IP detected IGFBPL1 (upper panel) and IGF-1 (lower panel) in protein complexes pulled down with primary antibodies against IGFBPL1 (middle) or IGF-1 (right). Left lane represents control co-IP result using a control rabbit IgG antibody. (C) Representative photomicrographs of cultured P0 RGCs treated with IGF-1 and/or IGFBPL1 in the absence or presence of NBI-31772 (NBI; 20 μM) or H1356 (40 μg/ml). Cells were immunolabeled with Tuj1. Scale bar: 20 μm. (D) Quantification of axon length in cultured RGCs (n = 5 cultures/group). Note that application of NBI-31772 or H1356 completely blocked either IGF-1- or IGFBPL1-induced axonal outgrowth. ***P < 0.001 as compared to the control (PBS) group by two-tailed student t-test. Error bars indicate standard error of mean (SEM).
