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: Woo-Ram Lee, Kyung-Hyun Kim, Hyun-Jin An, Jung-Yeon Kim, Sun-Jae Lee, Sang-Mi Han, Sok Cheon Pak, Kwan-kyu Park
• Journal: Biochemical and biophysical research communications (Biochem Biophys Res Commun) Vol. 450 Issue 1 Pg. 195-201 (Jul 18 2014) ISSN: 1090-2104 [Electronic] United States
• PMID: 24878534 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2014 Elsevier Inc. All rights reserved.

Chemical References

• Transforming Growth Factor beta1
• Apamin
• Carbon Tetrachloride

Topics

• Animals
• Apamin (administration & dosage)
• Carbon Tetrachloride
• Cell Line
• Epithelial-Mesenchymal Transition (drug effects)
• Hepatocytes (metabolism)
• Liver Cirrhosis (chemically induced, metabolism, pathology, prevention & control)
• Male
• Mice
• Mice, Inbred C57BL
• Transforming Growth Factor beta1 (pharmacology)
• Treatment Outcome