Supplementary Figure 9: PGD2 does not modulate AKT and MAPK pathways.

PGD2 does not activate AKT–1 and MAPK pathways. Rat primary Schwann were grown to confluence and then starved for 16 hours. Schwann cells were then treated with 2.5 ng/ml NRG1β1, 10 nM Cyclosporin A, 100 nM EtOH, 100 nM PGD2, 2.5 μM forskolin, 100 nM PGD2 together with 2.5 μM forskolin. Schwann cells lysates were tested by western blotting analyses for (a) AKT–1 phosphorylation (ser 473) and total AKT–1 levels and (b) p44/p42 phosphorylation and total p44/p42 levels. Shown images are representative of three different independent experiments. N = 3 different independent experiments. For uncropped pictures of western blots, see Supplementary Figure 10. c) Model of L–PGDS/GPR44 activity. NRG1 ICD, upon generation, translocates into the nucleus to specifically activate L–PGDS mRNA expression. L–PGDS protein is then released in the extracellular milieu where is enzymatically active. PGD2 binds to and activates glial Gpr44 resulting in dephosphorylation and nuclear translocation of Nfatc4 to promote myelination.