Thrombin activation of PI3K/PDK1/Akt signaling promotes cyclin D1 upregulation and RPE cell proliferation

► Thrombin induces Akt activation through Ser 473 phosphorylation in RPE cells. ► Akt signaling requires PI3K and PLC activation in thrombin-stimulated RPE cells. ► Thrombin promotes cyclin D1 accumulation through Akt-dependent GSK-3β inhibition. ► Akt activation is required for thrombin-induced RPE cell proliferation.