title: Biphasic Effects of Ingenol 3,20-Dibenzoate on the Erythropoietin Receptor: Synergism at Low Doses and Antagonism at High Doses.
abstract: Although ingenol 3,20-dibenzoate (IDB) is known as a selective novel protein kinase C (PKC) agonist, its biologic actions and underlying mechanisms remain incompletely understood. In this study, we identified IDB as a proliferative agent for an erythropoietin (EPO)-dependent cell line, UT-7/EPO, through the screening of a natural compound library. To clarify the underlying mechanism of IDB's EPO-like activities, we thoroughly analyzed the mutual relation between EPO and IDB in terms of in vitro and in vivo activities, signaling molecules, and a cellular receptor. IDB substantially induced the proliferation of UT-7/EPO cells, but not as much as EPO. IDB also lessened the anemia induced by 5-fluorouracil in an in vivo mouse model. Interestingly, IDB showed a synergistic effect on EPO at low concentration, but an antagonistic effect at higher concentration. Physical interaction and activation of PKCs by IDB- and EPO-competitive binding of IDB to EPO receptor (EPOR) explain these synergistic and antagonistic activities, respectively. Importantly, we addressed IDB's mechanism of action by demonstrating the direct binding of IDB to PKCs, and by identifying EPOR as a novel molecular target of IDB. Based on these dual targeting properties, IDB holds promise as a new small molecule modulator of EPO-related pathologic conditions.
authors.affiliation: Laboratory of Pharmacoimmunology, Integrated Research Institute of Pharmaceutical Sciences, College of Pharmacy, Catholic University of Korea, Bucheon, Republic of Korea (J.-G.O., H.E.K., T.-H.H.); College of Pharmacy, Dongguk University-Seoul, Seoul, Republic of Korea (Y.-W.C.); Department of Biotechnology, Hoseo University, Baebang, Asan, Chungnam, Republic of Korea (S.-J.K.); and College of Pharmacy, Chungnam National University, Daejeon, Republic of Korea (J.M.C., S.K.K.).
authors.forename: Jin-Gyo
authors.initials: JG
authors.lastname: Oh
authors.affiliation: Laboratory of Pharmacoimmunology, Integrated Research Institute of Pharmaceutical Sciences, College of Pharmacy, Catholic University of Korea, Bucheon, Republic of Korea (J.-G.O., H.E.K., T.-H.H.); College of Pharmacy, Dongguk University-Seoul, Seoul, Republic of Korea (Y.-W.C.); Department of Biotechnology, Hoseo University, Baebang, Asan, Chungnam, Republic of Korea (S.-J.K.); and College of Pharmacy, Chungnam National University, Daejeon, Republic of Korea (J.M.C., S.K.K.).
authors.forename: Young-Won
authors.initials: YW
authors.lastname: Chin
authors.affiliation: Laboratory of Pharmacoimmunology, Integrated Research Institute of Pharmaceutical Sciences, College of Pharmacy, Catholic University of Korea, Bucheon, Republic of Korea (J.-G.O., H.E.K., T.-H.H.); College of Pharmacy, Dongguk University-Seoul, Seoul, Republic of Korea (Y.-W.C.); Department of Biotechnology, Hoseo University, Baebang, Asan, Chungnam, Republic of Korea (S.-J.K.); and College of Pharmacy, Chungnam National University, Daejeon, Republic of Korea (J.M.C., S.K.K.).
authors.forename: Sung-Jo
authors.initials: SJ
authors.lastname: Kim
authors.affiliation: Laboratory of Pharmacoimmunology, Integrated Research Institute of Pharmaceutical Sciences, College of Pharmacy, Catholic University of Korea, Bucheon, Republic of Korea (J.-G.O., H.E.K., T.-H.H.); College of Pharmacy, Dongguk University-Seoul, Seoul, Republic of Korea (Y.-W.C.); Department of Biotechnology, Hoseo University, Baebang, Asan, Chungnam, Republic of Korea (S.-J.K.); and College of Pharmacy, Chungnam National University, Daejeon, Republic of Korea (J.M.C., S.K.K.).
authors.forename: Jong Min
authors.initials: JM
authors.lastname: Choi
authors.affiliation: Laboratory of Pharmacoimmunology, Integrated Research Institute of Pharmaceutical Sciences, College of Pharmacy, Catholic University of Korea, Bucheon, Republic of Korea (J.-G.O., H.E.K., T.-H.H.); College of Pharmacy, Dongguk University-Seoul, Seoul, Republic of Korea (Y.-W.C.); Department of Biotechnology, Hoseo University, Baebang, Asan, Chungnam, Republic of Korea (S.-J.K.); and College of Pharmacy, Chungnam National University, Daejeon, Republic of Korea (J.M.C., S.K.K.).
authors.forename: Sang Kyum
authors.initials: SK
authors.lastname: Kim
authors.affiliation: Laboratory of Pharmacoimmunology, Integrated Research Institute of Pharmaceutical Sciences, College of Pharmacy, Catholic University of Korea, Bucheon, Republic of Korea (J.-G.O., H.E.K., T.-H.H.); College of Pharmacy, Dongguk University-Seoul, Seoul, Republic of Korea (Y.-W.C.); Department of Biotechnology, Hoseo University, Baebang, Asan, Chungnam, Republic of Korea (S.-J.K.); and College of Pharmacy, Chungnam National University, Daejeon, Republic of Korea (J.M.C., S.K.K.).
authors.forename: Hee Eun
authors.initials: HE
authors.lastname: Kang
authors.affiliation: Laboratory of Pharmacoimmunology, Integrated Research Institute of Pharmaceutical Sciences, College of Pharmacy, Catholic University of Korea, Bucheon, Republic of Korea (J.-G.O., H.E.K., T.-H.H.); College of Pharmacy, Dongguk University-Seoul, Seoul, Republic of Korea (Y.-W.C.); Department of Biotechnology, Hoseo University, Baebang, Asan, Chungnam, Republic of Korea (S.-J.K.); and College of Pharmacy, Chungnam National University, Daejeon, Republic of Korea (J.M.C., S.K.K.) thhur92@catholic.ac.kr.
authors.forename: Tae-Hwe
authors.initials: TH
authors.lastname: Heo
mesh_terms: D000740:Anemia / Q000139:chemically induced / Q000188:drug therapy*; D000818:Animals; D002460:Cell Line; D049109:Cell Proliferation; D004195:Disease Models, Animal; D004224:Diterpenes / Q000008:administration & dosage* / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004336:Drug Antagonism; D004357:Drug Synergism; D004921:Erythropoietin / Q000235:genetics*; D006801:Humans; D008810:Mice, Inbred C57BL; D009154:Mutation; D011493:Protein Kinase C / Q000378:metabolism; D017467:Receptors, Erythropoietin / Q000037:antagonists & inhibitors* / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D004224:Diterpenes; D017467:Receptors, Erythropoietin; D004921:Erythropoietin; C011875:ingenol dibenzoate; D011493:Protein Kinase C