LPA and S1P effects of hES-NEP cell growth are mediated by Ptx sensitive G-proteins, EGF receptors, and ERK Map kinases. hES-NEP cells were pre-treated with 100 ng/mL Ptx, 2.5 μM AG1478, 10 μM U0126, 10 μM FR180204, 10 μM Y27632 or no treatment (NT) overnight and then treated with 100 nM LPA (A), 100 nM S1P (B) or vehicle. Cells were counted after treatment with inhibitors (time zero) and again after incubation with LPA or S1P. Results are reported as the number of new cells per well after LPA or S1P treatment; cell numbers at time zero have been subtracted. Data are representative of two independent experiments analyzed using an unpaired 2-tailed t-test. Comparisons were made between the LPA stimulated fold increase over basal growth in each condition. *: p < 0.05; **: p < 0.01.