title: Apamin inhibits hepatic fibrosis through suppression of transforming growth factor β1-induced hepatocyte epithelial-mesenchymal transition.
abstract: Apamin is an integral part of bee venom, as a peptide component. It has long been known as a highly selective block Ca(2+)-activated K(+) (SK) channels. However, the cellular mechanism and anti-fibrotic effect of apamin in TGF-β1-induced hepatocytes have not been explored. In the present study, we investigated the anti-fibrosis or anti-EMT mechanism by examining the effect of apamin on TGF-β1-induced hepatocytes. AML12 cells were seeded at ∼60% confluence in complete growth medium. Twenty-four hours later, the cells were changed to serum free medium containing the indicated concentrations of apamin. After 30 min, the cells were treated with 2 ng/ml of TGF-β1 and co-cultured for 48 h. Also, we investigated the effects of apamin on the CCl4-induced liver fibrosis animal model. Treatment of AML12 cells with 2 ng/ml of TGF-β1 resulted in loss of E-cadherin protein at the cell-cell junctions and concomitant increased expression of vimentin. In addition, phosphorylation levels of ERK1/2, Akt, Smad2/3 and Smad4 were increased by TGF-β1 stimulation. However, cells treated concurrently with TGF-β1 and apamin retained high levels of localized expression of E-cadherin and showed no increase in vimentin. Specifically, treatment with 2 μg/ml of apamin almost completely blocked the phosphorylation of ERK1/2, Akt, Smad2/3 and Smad4 in AML12 cells. In addition, apamin exhibited prevention of pathological changes in the CCl4-injected animal models. These results demonstrate the potential of apamin for the prevention of EMT progression induced by TGF-β1 in vitro and CCl4-injected in vivo.
authors.affiliation: Department of Pathology, College of Medicine, Catholic University of Daegu, Daegu, South Korea.
authors.forename: Woo-Ram
authors.initials: WR
authors.lastname: Lee
authors.affiliation: Department of Pathology, College of Medicine, Catholic University of Daegu, Daegu, South Korea.
authors.forename: Kyung-Hyun
authors.initials: KH
authors.lastname: Kim
authors.affiliation: Department of Pathology, College of Medicine, Catholic University of Daegu, Daegu, South Korea.
authors.forename: Hyun-Jin
authors.initials: HJ
authors.lastname: An
authors.affiliation: Department of Pathology, College of Medicine, Catholic University of Daegu, Daegu, South Korea.
authors.forename: Jung-Yeon
authors.initials: JY
authors.lastname: Kim
authors.affiliation: Department of Pathology, College of Medicine, Catholic University of Daegu, Daegu, South Korea.
authors.forename: Sun-Jae
authors.initials: SJ
authors.lastname: Lee
authors.affiliation: Department of Agricultural Biology, National Institute of Agricultural Science and Technology, Suwon, South Korea.
authors.forename: Sang-Mi
authors.initials: SM
authors.lastname: Han
authors.affiliation: School of Biomedical Sciences, Charles Sturt University, Bathurst, NSW 2795, Australia.
authors.forename: Sok Cheon
authors.initials: SC
authors.lastname: Pak
authors.affiliation: Department of Pathology, College of Medicine, Catholic University of Daegu, Daegu, South Korea. Electronic address: kkpark@cu.ac.kr.
authors.forename: Kwan-kyu
authors.initials: KK
authors.lastname: Park
mesh_terms: D000818:Animals; D001030:Apamin / Q000008:administration & dosage*; D002251:Carbon Tetrachloride; D002460:Cell Line; D058750:Epithelial-Mesenchymal Transition / Q000187:drug effects*; D022781:Hepatocytes / Q000378:metabolism*; D008103:Liver Cirrhosis / Q000139:chemically induced / Q000378:metabolism* / Q000473:pathology / Q000517:prevention & control*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D053773:Transforming Growth Factor beta1 / Q000494:pharmacology*; D016896:Treatment Outcome
chemical_list: D053773:Transforming Growth Factor beta1; D001030:Apamin; D002251:Carbon Tetrachloride
keywords: Apamin; CCl(4); EMT; Hepatocyte; Liver fibrosis; TGF-β1