Figure 13.

PTN induced the oligodendrocyte differentiation of OL1 cells. A, B, OL1 cells were cultured with various combinations of TH and PTN for 10 d. Cells were analyzed by immunocytochemistry (A) and Western blotting (B) with anti-NG2 proteoglycan (OPCs; red) and anti-MBP (oligodendrocytes, OLs; green) antibodies. The percentage of OPCs and OLs in all cells (DAPI-positive nuclei, blue) are shown at the bottom in A. Scale bars, 100 μm. PhC, Phase contrast. Data are the mean ± SEM (n = 5). **p < 0.01, Student's t test. C, D, PTN-induced phosphorylation of p190 RhoGAP at Tyr-1105. OL1 cells were incubated for 30 min with or without PTN in the presence of TH. C, The overall tyrosine phosphorylation pattern and protein expression were analyzed with anti-phosphotyrosine PY20 and anti-p190 RhoGAP antibodies, respectively. D, Tyr-1105 phosphorylation of p190 RhoGAP. Extracts were immunoprecipitated with anti-p190 RhoGAP antibody-coated beads and binding proteins were analyzed by Western blotting with anti-pY1105 and anti-p190 RhoGAP antibodies. Tyr-1105 phosphorylation levels were determined by densitometric analyses. Data are the mean ± SEM (n = 7). **p < 0.01, Student's t test.