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Jusakul A, Loilome W, Namwat N, Techasen A, Kuver R, Ioannou G, Savard C, Haigh WG, Yongvanit P. Anti-apoptotic phenotypes of cholestan-3β,5α,6β-triol-resistant human cholangiocytes: characteristics contributing to the genesis of cholangiocarcinoma. J Steroid Biochem Mol Biol 2013; 138:368-75. [PMID: 23959098 PMCID: PMC3825754 DOI: 10.1016/j.jsbmb.2013.08.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2013] [Revised: 07/29/2013] [Accepted: 08/06/2013] [Indexed: 12/30/2022]
Abstract
The oxysterols cholestan-3β,5α,6β-triol (Triol) and 3-keto-cholest-4-ene (3K4) are increased in Opisthorchis viverrini-associated hamster cholangiocarcinoma and induce DNA damage and apoptosis via a mitochondria-dependent mechanism in MMNK-1 human cholangiocytes. Based on these observations, we hypothesized that chronic exposure of cholangiocytes to these pathogenic oxysterols may allow a growth advantage to a subset of these cells through selection for resistance to apoptosis, thereby contributing to cholangiocarcinogenesis. To test this hypothesis, we cultured MMNK-1 cells long-term in the presence of Triol. Alteration in survival and apoptotic factors of Triol-exposed cells were examined. Cells cultured long-term in the presence of Triol were resistant to H2O2-induced apoptosis, and demonstrated an increase in the phosphorylation of p38-α, CREB, ERK1/2 and c-Jun. Elevations in the ratio of Bcl-2/Bax and in the protein levels of anti-apoptotic factors including cIAP2, clusterin, and survivin were detected. These results show that long-term exposure of MNNK-1 cells to low doses of Triol selects for kinase-signaling molecules which regulate resistance to apoptosis and thereby enhance cell survival. Clonal expansion of such apoptosis-resistant cells may contribute to the genesis of cholangiocarcinoma.
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Affiliation(s)
- Apinya Jusakul
- Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand
- Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand
- Department of Medicine, University of Washington School of Medicine and the Department of Veterans Affairs Medical Center, Seattle, WA, USA
| | - Watcharin Loilome
- Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand
- Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Nisana Namwat
- Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand
- Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Anchalee Techasen
- Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand
- Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand
- Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Rahul Kuver
- Department of Medicine, University of Washington School of Medicine and the Department of Veterans Affairs Medical Center, Seattle, WA, USA
| | - George Ioannou
- Department of Medicine, University of Washington School of Medicine and the Department of Veterans Affairs Medical Center, Seattle, WA, USA
| | - Christopher Savard
- Department of Medicine, University of Washington School of Medicine and the Department of Veterans Affairs Medical Center, Seattle, WA, USA
| | - W. Geoffrey Haigh
- Department of Medicine, University of Washington School of Medicine and the Department of Veterans Affairs Medical Center, Seattle, WA, USA
| | - Puangrat Yongvanit
- Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand
- Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand
- Corresponding author: Puangrat Yongvanit, Ph.D., Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand, Phone: +66(43)-348386, Fax: +66(43)-348386,
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Wakeman D, Guo J, Santos JA, Wandu WS, Schneider JE, McMellen ME, Leinicke JA, Erwin CR, Warner BW. p38 MAPK regulates Bax activity and apoptosis in enterocytes at baseline and after intestinal resection. Am J Physiol Gastrointest Liver Physiol 2012; 302:G997-1005. [PMID: 22383494 PMCID: PMC3362074 DOI: 10.1152/ajpgi.00485.2011] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Increased apoptosis in crypt enterocytes is a key feature of intestinal adaptation following massive small bowel resection (SBR). Expression of the proapoptotic factor Bax has been shown to be required for resection-induced apoptosis. It has also been demonstrated that p38-α MAPK (p38) is necessary for Bax activation and apoptosis in vitro. The present studies were designed to test the hypothesis that p38 is a key regulator of Bax activation during adaptation after SBR in vivo. Enterocyte expression of p38 was deleted by tamoxifen administration to activate villin-Cre in adult mice with a floxed Mapk14 (p38-α) gene. Proximal 50% SBR or sham operations were performed on wild-type (WT) and p38 intestinal knockout (p38-IKO) mice under isoflurane anesthesia. Mice were killed 3 or 7 days after operation, and adaptation was analyzed by measuring intestinal morphology, proliferation, and apoptosis. Bax activity was quantified by immunoprecipitation, followed by Western blotting. After SBR, p38-IKO mice had deeper crypts, longer villi, and accelerated proliferation compared with WT controls. Rates of crypt apoptosis were significantly lower in p38-IKO mice, both at baseline and after SBR. Levels of activated Bax were twofold higher in WT mice after SBR relative to sham. In contrast, activated Bax levels were reduced by 67% in mice after p38 MAPK deletion. Deleted p38 expression within the intestinal epithelium leads to enhanced adaptation and reduced levels of enterocyte apoptosis after massive intestinal resection. p38-regulated Bax activation appears to be an important mechanism underlying resection-induced apoptosis.
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Affiliation(s)
- Derek Wakeman
- Department of Surgery, Division of Pediatric Surgery, St. Louis Children's Hospital, Washington University School of Medicine, St. Louis, Missouri
| | - Jun Guo
- Department of Surgery, Division of Pediatric Surgery, St. Louis Children's Hospital, Washington University School of Medicine, St. Louis, Missouri
| | - Jethrina A. Santos
- Department of Surgery, Division of Pediatric Surgery, St. Louis Children's Hospital, Washington University School of Medicine, St. Louis, Missouri
| | - Wambui S. Wandu
- Department of Surgery, Division of Pediatric Surgery, St. Louis Children's Hospital, Washington University School of Medicine, St. Louis, Missouri
| | - John E. Schneider
- Department of Surgery, Division of Pediatric Surgery, St. Louis Children's Hospital, Washington University School of Medicine, St. Louis, Missouri
| | - Mark E. McMellen
- Department of Surgery, Division of Pediatric Surgery, St. Louis Children's Hospital, Washington University School of Medicine, St. Louis, Missouri
| | - Jennifer A. Leinicke
- Department of Surgery, Division of Pediatric Surgery, St. Louis Children's Hospital, Washington University School of Medicine, St. Louis, Missouri
| | - Christopher R. Erwin
- Department of Surgery, Division of Pediatric Surgery, St. Louis Children's Hospital, Washington University School of Medicine, St. Louis, Missouri
| | - Brad W. Warner
- Department of Surgery, Division of Pediatric Surgery, St. Louis Children's Hospital, Washington University School of Medicine, St. Louis, Missouri
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