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Ceulemans LJ, Canovai E, Verbeke L, Pirenne J, Farré R. The expanding role of the bile acid receptor farnesoid X in the intestine and its potential clinical implications. Acta Chir Belg 2016; 116:156-163. [PMID: 27684270 DOI: 10.1080/00015458.2016.1215953] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Knowledge about the role of farnesoid X receptor (FXR) in the intestine is rapidly expanding. In pre-clinical animal models of inflammatory bowel disease and bile duct ligation, FXR activation has proven to directly target the three pillars of intestinal homeostasis: intestinal permeability, inflammation and bacterial translocation. The protective role of FXR-ligands on this homeostasis has implications for many intestinal pathologies like inflammatory bowel disease, ischemia reperfusion injury, the metabolic syndrome, colon cancer and even diarrhea. In this review, we summarize the mechanisms by which FXR-activation exerts these protective effects and we discuss its potential clinical applications.
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102
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103
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Kong B, Zhu Y, Li G, Williams JA, Buckley K, Tawfik O, Luyendyk JP, Guo GL. Mice with hepatocyte-specific FXR deficiency are resistant to spontaneous but susceptible to cholic acid-induced hepatocarcinogenesis. Am J Physiol Gastrointest Liver Physiol 2016; 310:G295-302. [PMID: 26744468 PMCID: PMC4773826 DOI: 10.1152/ajpgi.00134.2015] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 12/12/2015] [Indexed: 01/31/2023]
Abstract
Farnesoid X receptor (FXR) belongs to the nuclear receptor superfamily with its endogenous ligands bile acids. Mice with whole body FXR deficiency develop liver tumors spontaneously, but the underlying mechanism is unclear. Moreover, it is unknown whether FXR deficiency in liver alone serves as a tumor initiator or promoter during liver carcinogenesis. This study aims to evaluate the effects of hepatocyte-specific FXR deficiency (FXR(hep-/-)) in liver tumor formation. The results showed that FXR(hep-/-) mice did not show spontaneous liver tumorigenesis with aging (up to 24 mo of age). Therefore FXR(hep-/-) mice were fed a bile acid (cholic acid)-containing diet alone or along with a liver tumor initiator, diethylnitrosamine (DEN). Thirty weeks later, no tumors were found in wild-type or FXR(hep-/-) mice without any treatment or with DEN only. However, with cholic acid, while only some wild-type mice developed tumors, all FXR(hep-/-) mice presented with severe liver injury and tumors. Interestingly, FXR(hep-/-) mouse livers increased basal expression of tumor suppressor p53 protein, apoptosis, and decreased basal cyclin D1 expression, which may prevent tumor development in FXR(hep-/-) mice. However, cholic acid feeding reversed these effects in FXR(hep-/-) mice, which is associated with an increased cyclin D1 and decreased cell cycle inhibitors. More in-depth analysis indicates that the increased in cell growth might result from disturbance of the MAPK and JAK/Stat3 signaling pathways. In conclusion, this study shows that hepatic FXR deficiency may only serve as a tumor initiator, and increased bile acids is required for tumor formation likely by promoting cell proliferation.
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Affiliation(s)
- Bo Kong
- 1Department of Pharmacology and Toxicology, School of Pharmacy, Rutgers University, Piscataway, New Jersey;
| | - Yan Zhu
- 2Department of General Surgery, Xuanwu Hospital, Capital Medical University, Beijing, China;
| | - Guodong Li
- 3Department of General Surgery, the Fourth Hospital of Harbin Medical University, Harbin; ,4Division of Biobank Research, Department of General Surgery, the Fourth Hospital of Harbin Medical University, Harbin;
| | - Jessica A. Williams
- 5Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas;
| | - Kyle Buckley
- 1Department of Pharmacology and Toxicology, School of Pharmacy, Rutgers University, Piscataway, New Jersey;
| | - Ossama Tawfik
- 6Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, Kansas; and
| | - James P. Luyendyk
- 7Pathobiology and Diagnostic Investigation, Michigan State University, East Lansing, Michigan
| | - Grace L. Guo
- 1Department of Pharmacology and Toxicology, School of Pharmacy, Rutgers University, Piscataway, New Jersey;
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104
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Activated FXR Inhibits Leptin Signaling and Counteracts Tumor-promoting Activities of Cancer-Associated Fibroblasts in Breast Malignancy. Sci Rep 2016; 6:21782. [PMID: 26899873 PMCID: PMC4761870 DOI: 10.1038/srep21782] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 02/01/2016] [Indexed: 12/21/2022] Open
Abstract
Cancer-associated fibroblasts (CAFs), the principal components of the tumor stroma, play a central role in cancer development and progression. As an important regulator of the crosstalk between breast cancer cells and CAFs, the cytokine leptin has been associated to breast carcinogenesis. The nuclear Farnesoid X Receptor-(FXR) seems to exert an oncosuppressive role in different tumors, including breast cancer. Herein, we demonstrated, for the first time, that the synthetic FXR agonist GW4064, inhibiting leptin signaling, affects the tumor-promoting activities of CAFs in breast malignancy. GW4064 inhibited growth, motility and invasiveness induced by leptin as well as by CAF-conditioned media in different breast cancer cell lines. These effects rely on the ability of activated FXR to increase the expression of the suppressor of the cytokine signaling 3 (SOCS3) leading to inhibition of leptin-activated signaling and downregulation of leptin-target genes. In vivo xenograft studies, using MCF-7 cells alone or co-injected with CAFs, showed that GW4064 administration markedly reduced tumor growth. Interestingly, GW4064-treated tumors exhibited decreased levels of leptin-regulated proteins along with a strong staining intensity for SOCS3. Thus, FXR ligands might represent an emerging potential anti-cancer therapy able to block the tumor supportive role of activated fibroblasts within the breast microenvironment.
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105
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Selmin OI, Fang C, Lyon AM, Doetschman TC, Thompson PA, Martinez JD, Smith JW, Lance PM, Romagnolo DF. Inactivation of Adenomatous Polyposis Coli Reduces Bile Acid/Farnesoid X Receptor Expression through Fxr gene CpG Methylation in Mouse Colon Tumors and Human Colon Cancer Cells. J Nutr 2016; 146:236-42. [PMID: 26609171 PMCID: PMC6636391 DOI: 10.3945/jn.115.216580] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 11/03/2015] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND The farnesoid X receptor (FXR) regulates bile acid (BA) metabolism and possesses tumor suppressor functions. FXR expression is reduced in colorectal tumors of subjects carrying inactivated adenomatous polyposis coli (APC). Identifying the mechanisms responsible for this reduction may offer new molecular targets for colon cancer prevention. OBJECTIVE We investigated how APC inactivation influences the regulation of FXR expression in colonic mucosal cells. We hypothesized that APC inactivation would epigenetically repress nuclear receptor subfamily 1, group H, member 4 (FXR gene name) expression through increased CpG methylation. METHODS Normal proximal colonic mucosa and normal-appearing adjacent colonic mucosa and colon tumors were collected from wild-type C57BL/6J and Apc-deficient (Apc(Min) (/+)) male mice, respectively. The expression of Fxr, ileal bile acid-binding protein (Ibabp), small heterodimer partner (Shp), and cyclooxygenase-2 (Cox-2) were determined by real-time polymerase chain reaction. In both normal and adjacent colonic mucosa and colon tumors, we measured CpG methylation of Fxr in bisulfonated genomic DNA. In vitro, we measured the impact of APC inactivation and deoxycholic acid (DCA) treatment on FXR expression in human colon cancer HCT-116 cells transfected with silencing RNA for APC and HT-29 cells carrying inactivated APC. RESULTS In Apc(Min) (/+) mice, constitutive CpG methylation of the Fxrα3/4 promoter was linked to reduced (60-90%) baseline Fxr, Ibabp, and Shp and increased Cox-2 expression in apparently normal adjacent mucosa and colon tumors. Apc knockdown in HCT-116 cells increased cellular myelocytomatosis (c-MYC) and lowered (∼50%) FXR expression, which was further reduced (∼80%) by DCA. In human HCT-116 but not HT-29 colon cancer cells, DCA induced FXR expression and lowered CpG methylation of FXR. CONCLUSIONS We conclude that the loss of APC function favors the silencing of FXR expression through CpG hypermethylation in mouse colonic mucosa and human colon cells, leading to reduced expression of downstream targets (SHP, IBABP) involved in BA homeostasis while increasing the expression of factors (COX-2, c-MYC) that contribute to inflammation and colon cancer.
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Affiliation(s)
- Ornella I Selmin
- Department of Nutritional Sciences, University of Arizona, Tucson, AZ,University of Arizona Cancer Center, University of Arizona, Tucson, AZ
| | - Changming Fang
- University of Arizona Cancer Center, University of Arizona, Tucson, AZ
| | - Adam M Lyon
- Department of Nutritional Sciences, University of Arizona, Tucson, AZ
| | - Tom C Doetschman
- University of Arizona Cancer Center, University of Arizona, Tucson, AZ
| | | | - Jesse D Martinez
- University of Arizona Cancer Center, University of Arizona, Tucson, AZ
| | - Jeffrey W Smith
- Sanford/Burnham Medical Research Institute, Cancer Center Division, La
Jolla, CA
| | - Peter M Lance
- University of Arizona Cancer Center, University of Arizona, Tucson, AZ
| | - Donato F Romagnolo
- Department of Nutritional Sciences and University of Arizona Cancer Center, University of Arizona, Tucson, AZ; and
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106
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Zhan L, Yang I, Kong B, Shen J, Gorczyca L, Memon N, Buckley BT, Guo GL. Dysregulation of bile acid homeostasis in parenteral nutrition mouse model. Am J Physiol Gastrointest Liver Physiol 2016; 310:G93-G102. [PMID: 26564717 PMCID: PMC4719060 DOI: 10.1152/ajpgi.00252.2015] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 11/07/2015] [Indexed: 01/31/2023]
Abstract
Long-term parenteral nutrition (PN) administration can lead to PN-associated liver diseases (PNALD). Although multiple risk factors have been identified for PNALD, to date, the roles of bile acids (BAs) and the pathways involved in BA homeostasis in the development and progression of PNALD are still unclear. We have established a mouse PN model with IV infusion of PN solution containing soybean oil-based lipid emulsion (SOLE). Our results showed that PN altered the expression of genes involved in a variety of liver functions at the mRNA levels. PN increased liver gene expression of Cyp7a1 and markedly decreased that of Cyp8b1, Cyp7b1, Bsep, and Shp. CYP7A1 and CYP8B1 are important for synthesizing the total amount of BAs and regulating the hydrophobicity of BAs, respectively. Consistently, both the levels and the percentages of primary BAs as well as total non-12α-OH BAs increased significantly in the serum of PN mice compared with saline controls, whereas liver BA profiles were largely similar. The expression of several key liver-X receptor-α (LXRα) target genes involved in lipid synthesis was also increased in PN mouse livers. Retinoid acid-related orphan receptor-α (RORα) has been shown to induce the expression of Cyp8b1 and Cyp7b1, as well as to suppress LXRα function. Western blot showed significantly reduced nuclear migration of RORα protein in PN mouse livers. This study shows that continuous PN infusion with SOLE in mice leads to dysregulation of BA homeostasis. Alterations of liver RORα signaling in PN mice may be one of the mechanisms implicated in the pathogenesis of PNALD.
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Affiliation(s)
- Le Zhan
- 1Department of Pharmacology and Toxicology, School of Pharmacy, Rutgers University, Piscataway, New Jersey;
| | - Ill Yang
- 2EOHSI/Chemical Analytical Core Laboratory, Rutgers University, Piscataway, New Jersey;
| | - Bo Kong
- 1Department of Pharmacology and Toxicology, School of Pharmacy, Rutgers University, Piscataway, New Jersey;
| | - Jianliang Shen
- 1Department of Pharmacology and Toxicology, School of Pharmacy, Rutgers University, Piscataway, New Jersey;
| | - Ludwik Gorczyca
- 1Department of Pharmacology and Toxicology, School of Pharmacy, Rutgers University, Piscataway, New Jersey;
| | - Naureen Memon
- 3Department of Pediatrics, Rutgers Robert Wood Johnson Medical School, New Brunswick, New Jersey
| | - Brian T. Buckley
- 2EOHSI/Chemical Analytical Core Laboratory, Rutgers University, Piscataway, New Jersey;
| | - Grace L. Guo
- 1Department of Pharmacology and Toxicology, School of Pharmacy, Rutgers University, Piscataway, New Jersey;
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107
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Zhou B, Feng B, Qin Z, Zhao Y, Chen Y, Shi Z, Gong Y, Zhang J, Yuan F, Mu J. Activation of farnesoid X receptor downregulates visfatin and attenuates diabetic nephropathy. Mol Cell Endocrinol 2016; 419:72-82. [PMID: 26450152 DOI: 10.1016/j.mce.2015.10.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2015] [Revised: 09/29/2015] [Accepted: 10/01/2015] [Indexed: 02/07/2023]
Abstract
Visfatin, a recently discovered adipocytokine, has been shown to have an important role in the pathogenesis of diabetic nephropathy (DN). The farnesoid X receptor (FXR), a ligand-activated nuclear receptor, plays a protective role in DN. The regulation between FXR and visfatin and their interaction in DN has not been well established. In this study, we reported that FXR agonist GW4064 reduced high glucose induced human mesangial cells (HMCs) inflammation, fibrosis and proliferation by downregulating visfatin expression, which can be blunted by exogenous visfatin treatment. Moreover, luciferase reporter assay showed FXR regulated visfatin transcription activity probably by binding to the -1607 bp and -1192 bp region of the visfatin promoter. In vivo study also showed that GW4064 ameliorated the progression of DN in db/db mice with a decreased visfatin expression. These findings suggest that FXR activation delayed the progression of diabetic nephropathy and this effect is through downregulating visfatin.
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Affiliation(s)
- Baoshang Zhou
- Department of Nephrology, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China
| | - Bing Feng
- Department of Nephrology, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China
| | - Zhexue Qin
- Department of Cardiology, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China
| | - Youguang Zhao
- Department of Urology, Chengdu Military General Hospital, Chengdu 610083, China
| | - Yu Chen
- Department of Nephrology, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China
| | - Zhengmin Shi
- Department of Nephrology, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China
| | - Yi Gong
- Department of Nephrology, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China
| | - Jing Zhang
- Department of Nephrology, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China
| | - Fahuan Yuan
- Department of Nephrology, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China.
| | - Jiao Mu
- Department of Nephrology, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China.
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108
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Zhang X, Osaka T, Tsuneda S. Bacterial metabolites directly modulate farnesoid X receptor activity. Nutr Metab (Lond) 2015; 12:48. [PMID: 26604978 PMCID: PMC4657204 DOI: 10.1186/s12986-015-0045-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 11/18/2015] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND The farnesoid X receptor (FXR), a ligand-activated transcription factor belonging to the adopted orphan receptor, plays an important role in maintaining health of the liver and intestine. In this study, we identified individual bacterial strains that directly modulated the activation of intestinal FXR. METHODS The FXR stimulatory potential of 38 bacterial strains was determined using a stable FXR reporter system derived from intestinal epithelial cells (IEC). The induction of FXR target genes by screened FXR stimulatory bacteria was determined by real-time PCR. In addition, a high fat diet (HFD)-induced obese mouse model was used to evaluate in vivo FXR stimulatory potential of bacterial metabolites screened in this study. RESULTS A luciferase assay with the FXR reporter cell line demonstrated that the FXR-stimulatory activity of most bacterial cell samples was less than 2-fold. The culture supernatants of Bacteroides dorei and Eubacterium limosum induced FXR activity and selectively regulated FXR target expression in the FXR reporter system. Treatment with B. dorei-derived metabolites strongly induced ileal bile acid binding protein (IBABP) (8.4-fold) and organic solute transporter (OST) α (3.1-fold) compared with E. limosum-derived metabolites. Furthermore, administration of B. dorei derived metabolites showed significant reduction in body weight gain, and both two bacterial metabolites reduced liver weight in obese mice compared to PBS-treated controls. Administration of each bacterial metabolites improved in serum levels of obesity-related metabolic biochemical markers such as ALT, AST, total cholesterol, and triglyceride. Furthermore, two bacterial metabolites enhanced the Fxr gene expression in the intestine and liver, and ileal Shp gene expression tended to be increased by treatment with the metabolites derived from B. dorei. CONCLUSIONS B. dorei and E. limosum secreted the bioactive substances that directly stimulate FXR in the intestinal epithelial cells. Administration of these bacterial FXR-stimulatory metabolites improves the obesity phenotype including body weight gain, liver damage, lipid metabolism in DIO mice.
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Affiliation(s)
- Xianqin Zhang
- Department of Life Science and Medical Bioscience, Waseda University, Tokyo, 162-8480 Japan
| | - Toshifumi Osaka
- Department of Life Science and Medical Bioscience, Waseda University, Tokyo, 162-8480 Japan.,Department of Microbiology and Immunology, Tokyo Women's Medical University, Tokyo, 162-8666 Japan
| | - Satoshi Tsuneda
- Department of Life Science and Medical Bioscience, Waseda University, Tokyo, 162-8480 Japan
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Baars A, Oosting A, Knol J, Garssen J, van Bergenhenegouwen J. The Gut Microbiota as a Therapeutic Target in IBD and Metabolic Disease: A Role for the Bile Acid Receptors FXR and TGR5. Microorganisms 2015; 3:641-66. [PMID: 27682110 PMCID: PMC5023267 DOI: 10.3390/microorganisms3040641] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 10/01/2015] [Indexed: 12/18/2022] Open
Abstract
The gut microbiota plays a crucial role in regulating many physiological systems of the host, including the metabolic and immune system. Disturbances in microbiota composition are increasingly correlated with disease; however, the underlying mechanisms are not well understood. Recent evidence suggests that changes in microbiota composition directly affect the metabolism of bile salts. Next to their role in digestion of dietary fats, bile salts function as signaling molecules for bile salt receptors such as Farnesoid X receptor (FXR) and G protein-coupled bile acid receptor (TGR5). Complementary to their role in metabolism, FXR and TGR5 are shown to play a role in intestinal homeostasis and immune regulation. This review presents an overview of evidence showing that changes in bile salt pool and composition due to changes in gut microbial composition contribute to the pathogenesis of inflammatory bowel disease and metabolic disease, possibly through altered activation of TGR5 and FXR. We further discuss how dietary interventions, such as pro- and synbiotics, may be used to treat metabolic disease and inflammatory bowel disease (IBD) through normalization of bile acid dysregulation directly or indirectly through normalization of the intestinal microbiota.
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Affiliation(s)
| | | | - Jan Knol
- Nutricia Research, 3584 CT, Utrecht, The Netherlands.
- Laboratory of Microbiology, Wageningen University, 6703 HB, Wageningen, The Netherlands.
| | - Johan Garssen
- Nutricia Research, 3584 CT, Utrecht, The Netherlands.
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, 3584 CG, Utrecht, The Netherlands.
| | - Jeroen van Bergenhenegouwen
- Nutricia Research, 3584 CT, Utrecht, The Netherlands.
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, 3584 CG, Utrecht, The Netherlands.
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Shaik FB, Panati K, Narasimha VR, Narala VR. Chenodeoxycholic acid attenuates ovalbumin-induced airway inflammation in murine model of asthma by inhibiting the T(H)2 cytokines. Biochem Biophys Res Commun 2015; 463:600-5. [PMID: 26067554 DOI: 10.1016/j.bbrc.2015.05.104] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 05/29/2015] [Indexed: 12/11/2022]
Abstract
Asthma is a complex highly prevalent airway disease that is a major public health problem for which current treatment options are inadequate. Recently, farnesoid X receptor (FXR) has been shown to exert anti-inflammatory actions in various disease conditions, but there have been no reported investigations of Chenodeoxycholic acid (CDCA), a natural FXR agonist, in allergic airway inflammation. To test the CDCA effectiveness in airway inflammation, ovalbumin (OVA)-induced acute murine asthma model was established. We found that lung tissue express FXR and CDCA administration reduced the severity of the murine allergic airway disease as assessed by pathological and molecular markers associated with the disease. CDCA treatment resulted in fewer infiltrations of cells into the airspace and peribronchial areas, and decreased goblet cell hyperplasia, mucus secretion and serum IgE levels which was increased in mice with OVA-induced allergic asthma. The CDCA treatment further blocked the secretion of TH2 cytokines (IL-4, IL-5 and IL-13) and proinflammatory cytokine TNF-α indicate that the FXR and its agonists may have potential for treating allergic asthma.
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Affiliation(s)
| | - Kalpana Panati
- Department of Biotechnology, Govt. College for Men, Kadapa, A.P., India
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Leo VI, Tan SH, Bergmann H, Cheah PY, Chew MH, Lim KH, Ruland J, Reilly PT. CARD9 Promotes Sex-Biased Colon Tumors in the APCmin Mouse Model. Cancer Immunol Res 2015; 3:721-6. [PMID: 25941350 DOI: 10.1158/2326-6066.cir-14-0148] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2014] [Accepted: 04/14/2015] [Indexed: 11/16/2022]
Abstract
Caspase recuitment domain-containing protein 9 (CARD9) functions in different inflammation pathways to elicit responses to microbial signals and is known to affect intestinal inflammation. Examining the APC(min) mouse model of intestinal tumorigenesis and using stringently controlled, sex- and age-matched pairs of CARD9-competent and CARD9-deficient mice, we have found that CARD9 has a restricted but strong effect on tumorigenesis in the large intestine. We have found that CARD9 reduces viability specifically in males and promotes tumorigenesis specifically in the large intestines of these male mice. To our knowledge, this is the first gene ablation in APC(min) mice that solely affects colon tumors in male subjects and, as such, may have significant clinical implications. Additional data suggest correlative disruption of plasma cytokine expression and immune infiltration of the tumors. We speculate that known sex-specific differences in human colorectal cancer may involve inflammation, particularly CARD9-dependent inflammation.
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Affiliation(s)
- Vonny I Leo
- Laboratory of Inflammation Biology, National Cancer Centre, Singapore, Singapore
| | - Sze Huey Tan
- Division of Clinical Trials and Epidemiological Sciences, National Cancer Centre, Singapore, Singapore
| | - Hanna Bergmann
- Institut für Klinische Chemie und Pathobiochemie, Klinikum rechts der Isar, Technische Universität München, Münich, Germany
| | - Peh Yean Cheah
- Department of Colorectal Surgery, Singapore General Hospital, Singapore, Singapore. Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore. Duke-NUS Graduate Medical School, National University of Singapore, Singapore, Singapore
| | - Min Hoe Chew
- Department of Colorectal Surgery, Singapore General Hospital, Singapore, Singapore
| | - Kiat Hon Lim
- Department of Pathology, Singapore General Hospital, Singapore, Singapore
| | - Jürgen Ruland
- Institut für Klinische Chemie und Pathobiochemie, Klinikum rechts der Isar, Technische Universität München, Münich, Germany
| | - Patrick T Reilly
- Laboratory of Inflammation Biology, National Cancer Centre, Singapore, Singapore.
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112
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Mazuy C, Helleboid A, Staels B, Lefebvre P. Nuclear bile acid signaling through the farnesoid X receptor. Cell Mol Life Sci 2015; 72:1631-50. [PMID: 25511198 PMCID: PMC11113650 DOI: 10.1007/s00018-014-1805-y] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Revised: 12/04/2014] [Accepted: 12/08/2014] [Indexed: 12/16/2022]
Abstract
Bile acids (BAs) are amphipathic molecules produced from cholesterol by the liver. Expelled from the gallbladder upon meal ingestion, BAs serve as fat solubilizers in the intestine. BAs are reabsorbed in the ileum and return via the portal vein to the liver where, together with nutrients, they provide signals to coordinate metabolic responses. BAs act on energy and metabolic homeostasis through the activation of membrane and nuclear receptors, among which the nuclear receptor farnesoid X receptor (FXR) is an important regulator of several metabolic pathways. Highly expressed in the liver and the small intestine, FXR contributes to BA effects on metabolism, inflammation and cell cycle control. The pharmacological modulation of its activity has emerged as a potential therapeutic strategy for liver and metabolic diseases. This review highlights recent advances regarding the mechanisms by which the BA sensor FXR contributes to global signaling effects of BAs, and how FXR activity may be regulated by nutrient-sensitive signaling pathways.
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Affiliation(s)
- Claire Mazuy
- European Genomic Institute for Diabetes (EGID), 59000 Lille, France
- INSERM UMR1011-Bâtiment J&K, 59000 Lille, France
- University Lille 2, 59000 Lille, France
- Institut Pasteur de Lille, 59019 Lille, France
| | - Audrey Helleboid
- European Genomic Institute for Diabetes (EGID), 59000 Lille, France
- INSERM UMR1011-Bâtiment J&K, 59000 Lille, France
- University Lille 2, 59000 Lille, France
- Institut Pasteur de Lille, 59019 Lille, France
| | - Bart Staels
- European Genomic Institute for Diabetes (EGID), 59000 Lille, France
- INSERM UMR1011-Bâtiment J&K, 59000 Lille, France
- University Lille 2, 59000 Lille, France
- Institut Pasteur de Lille, 59019 Lille, France
| | - Philippe Lefebvre
- European Genomic Institute for Diabetes (EGID), 59000 Lille, France
- INSERM UMR1011-Bâtiment J&K, 59000 Lille, France
- University Lille 2, 59000 Lille, France
- Institut Pasteur de Lille, 59019 Lille, France
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Roshan-Moniri M, Hsing M, Butler MS, Cherkasov A, Rennie PS. Orphan nuclear receptors as drug targets for the treatment of prostate and breast cancers. Cancer Treat Rev 2015; 40:1137-52. [PMID: 25455729 DOI: 10.1016/j.ctrv.2014.10.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Revised: 10/10/2014] [Accepted: 10/13/2014] [Indexed: 02/06/2023]
Abstract
Nuclear receptors (NRs), a family of 48 transcriptional factors, have been studied intensively for their roles in cancer development and progression. The presence of distinctive ligand binding sites capable of interacting with small molecules has made NRs attractive targets for developing cancer therapeutics. In particular, a number of drugs have been developed over the years to target human androgen- and estrogen receptors for the treatment of prostate cancer and breast cancer. In contrast, orphan nuclear receptors (ONRs), which in many cases lack known biological functions or ligands, are still largely under investigated. This review is a summary on ONRs that have been implicated in prostate and breast cancers, specifically retinoic acid-receptor-related orphan receptors (RORs), liver X receptors (LXRs), chicken ovalbumin upstream promoter transcription factors (COUP-TFs), estrogen related receptors (ERRs), nerve growth factor 1B-like receptors, and ‘‘dosage-sensitive sex reversal, adrenal hypoplasia critical region, on chromosome X, gene 1’’ (DAX1). Discovery and development of small molecules that can bind at various functional sites on these ONRs will help determine their biological functions. In addition, these molecules have the potential to act as prototypes for future drug development. Ultimately, the therapeutic value of targeting the ONRs may go well beyond prostate and breast cancers.
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Ding L, Yang L, Wang Z, Huang W. Bile acid nuclear receptor FXR and digestive system diseases. Acta Pharm Sin B 2015; 5:135-44. [PMID: 26579439 PMCID: PMC4629217 DOI: 10.1016/j.apsb.2015.01.004] [Citation(s) in RCA: 242] [Impact Index Per Article: 26.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 12/31/2014] [Accepted: 01/05/2015] [Indexed: 12/14/2022] Open
Abstract
Bile acids (BAs) are not only digestive surfactants but also important cell signaling molecules, which stimulate several signaling pathways to regulate some important biological processes. The bile-acid-activated nuclear receptor, farnesoid X receptor (FXR), plays a pivotal role in regulating bile acid, lipid and glucose homeostasis as well as in regulating the inflammatory responses, barrier function and prevention of bacterial translocation in the intestinal tract. As expected, FXR is involved in the pathophysiology of a wide range of diseases of gastrointestinal tract, including inflammatory bowel disease, colorectal cancer and type 2 diabetes. In this review, we discuss current knowledge of the roles of FXR in physiology of the digestive system and the related diseases. Better understanding of the roles of FXR in digestive system will accelerate the development of FXR ligands/modulators for the treatment of digestive system diseases.
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Key Words
- 6-ECDCA, 6α-ethyl-chenodeoxycholic acid
- AF2, activation domain
- ANGTPL3, angiopoietin-like protein 3
- AOM, azoxymethane
- AP-1, activator protein-1
- ASBT, apical sodium-dependent bile salt transporter
- Apo, apolipoprotein
- BAAT, bile acid-CoA amino acid N-acetyltransferase
- BACS, bile acid-CoA synthetase
- BAs, bile acids
- BMI, body mass index
- BSEP, bile salt export pump
- Bile acids
- CA, cholic acid
- CD, Crohn׳s disease
- CDCA, chenodeoxycholic acid
- CREB, cAMP regulatory element-binding protein
- CYP7A1, cholesterol 7α-hydroxylase
- Colorectal cancer
- DBD, DNA binding domain
- DCA, deoxycholic acid
- DSS, dextrane sodium sulfate
- ERK, extracellular signal-regulated kinase
- FABP6, fatty acid-binding protein subclass 6
- FFAs, free fatty acids
- FGF19, fibroblast growth factor 19
- FGFR4, fibroblast growth factor receptor 4
- FXR, farnesoid X receptor
- FXRE, farnesoid X receptor response element
- Farnesoid X receptor
- G6Pase, glucose-6-phosphatase
- GLP-1, glucagon-like peptide 1
- GLUT2, glucose transporter type 2
- GPBAR, G protein-coupled BA receptor
- GPCRs, G protein-coupled receptors
- GSK3, glycogen synthase kinase 3
- Gastrointestinal tract
- HDL-C, high density lipoprotein cholesterol
- HNF4α, hepatic nuclear factor 4α
- I-BABP, intestinal bile acid-binding protein
- IBD, inflammatory bowel disease
- IL-1, interleukin 1
- Inflammatory bowel disease
- KLF11, Krüppel-like factor 11
- KRAS, Kirsten rat sarcoma viral oncogene homolog
- LBD, ligand binding domain
- LCA, lithocholic acid
- LPL, lipoprotein lipase
- LRH-1, liver receptor homolog-1
- MCA, muricholicacid
- MRP2, multidrug resistance-associated protein 2
- NF-κB, nuclear factor-kappa B
- NOD, non-obese diabetic
- NRs, nuclear receptors
- OSTα, organic solute transporter alpha
- OSTβ, organic solute transporter beta
- PEPCK, phosphoenol pyruvate carboxykinase
- PGC-1α, peroxisome proliferators-activated receptor γ coactivator protein-1α
- SHP, small heterodimer partner
- SREBP-1c, sterol regulatory element-binding protein 1c
- STAT3, signal transducers and activators of transcription 3
- T2D, type 2 diabetes
- TLCA, taurolithocholic acid
- TNBS, trinitrobenzensulfonic acid
- TNFα, tumor necrosis factors α
- Type 2 diabetes
- UC, ulcerative colitis
- UDCA, ursodeoxycholic acid
- VSG, vertical sleeve gastrectomy
- db/db, diabetic mice
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Cheng Q, Inaba Y, Lu P, Xu M, He J, Zhao Y, Guo GL, Kuruba R, de la Vega R, Evans RW, Li S, Xie W. Chronic activation of FXR in transgenic mice caused perinatal toxicity and sensitized mice to cholesterol toxicity. Mol Endocrinol 2015; 29:571-82. [PMID: 25719402 DOI: 10.1210/me.2014-1337] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The nuclear receptor farnesoid X receptor (FXR) (nuclear receptor subfamily 1, group H, member 4, or NR1H4) is highly expressed in the liver and intestine. Previous reports have suggested beneficial functions of FXR in the homeostasis of bile acids, lipids, and glucose, as well as in promoting liver regeneration and inhibiting carcinogenesis. To investigate the effect of chronic FXR activation in vivo, we generated transgenic mice that conditionally and tissue specifically express the activated form of FXR in the liver and intestine. Unexpectedly, the transgenic mice showed several intriguing phenotypes, including partial neonatal lethality, growth retardation, and spontaneous liver toxicity. The transgenic mice also displayed heightened sensitivity to a high-cholesterol diet-induced hepatotoxicity but resistance to the gallstone formation. The phenotypes were transgene specific, because they were abolished upon treatment with doxycycline to silence the transgene expression. The perinatal toxicity, which can be rescued by a maternal vitamin supplement, may have resulted from vitamin deficiency due to low biliary bile acid output as a consequence of inhibition of bile acid formation. Our results also suggested that the fibroblast growth factor-inducible immediate-early response protein 14 (Fn14), a member of the proinflammatory TNF family, is a FXR-responsive gene. However, the contribution of Fn14 induction in the perinatal toxic phenotype of the transgenic mice remains to be defined. Because FXR is being explored as a therapeutic target, our results suggested that a chronic activation of this nuclear receptor may have an unintended side effect especially during the perinatal stage.
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Affiliation(s)
- Qiuqiong Cheng
- Center for Pharmacogenetics and Department of Pharmaceutical Sciences (Q.C., Y.I., P.L., M.X., J.H., Y.Z., R.K., S.L., W.X.), and Departments of Epidemiology (R.D.L.V., R.W.E.) and Pharmacology and Chemical Biology (W.X.), University of Pittsburgh, Pittsburgh, Pennsylvania 15261; and Department of Pharmacology and Toxicology (G.L.G.), Ernest Mario School of Pharmacy, Rutgers University, Piscataway, New Jersey 08854
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116
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Bile acid signaling through farnesoid X and TGR5 receptors in hepatobiliary and intestinal diseases. Hepatobiliary Pancreat Dis Int 2015; 14:18-33. [PMID: 25655287 DOI: 10.1016/s1499-3872(14)60307-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND The well-known functions of bile acids (BAs) are the emulsification and absorption of lipophilic xenobiotics. However, the emerging evidences in the past decade showed that BAs act as signaling molecules that not only autoregulate their own metabolism and enterohepatic recirculation, but also as important regulators of integrative metabolism by activating nuclear and membrane-bound G protein-coupled receptors. The present review was to get insight into the role of maintenance of BA homeostasis and BA signaling pathways in development and management of hepatobiliary and intestinal diseases. DATA SOURCES Detailed and comprehensive search of PubMed and Scopus databases was carried out for original and review articles. RESULTS Disturbances in BA homeostasis contribute to the development of several hepatobiliary and intestinal disorders, such as non-alcoholic fatty liver disease, liver cirrhosis, cholesterol gallstone disease, intestinal diseases and both hepatocellular and colorectal carcinoma. CONCLUSION Further efforts made in order to advance the understanding of sophisticated BA signaling network may be promising in developing novel therapeutic strategies related not only to hepatobiliary and gastrointestinal but also systemic diseases.
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117
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Yang F, Hu Y, Liu HX, Wan YJY. MiR-22-silenced cyclin A expression in colon and liver cancer cells is regulated by bile acid receptor. J Biol Chem 2015; 290:6507-15. [PMID: 25596928 DOI: 10.1074/jbc.m114.620369] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Because of the significant tumor-suppressive role of microRNA-22 (miR-22), the current study was designed to understand the regulation of miR-22 and to identify additional downstream miR-22 targets in liver and colon cells. The data showed that miR-22 was transcriptionally regulated by bile acid receptor farnesoid X receptor (FXR) through direct binding to an invert repeat 1 motif located at -1012 to -1025 bp upstream from miR-22. Among the studied primary and secondary bile acids, chenodeoxycholic acid, which has the highest binding affinity to FXR, induced miR-22 level in both Huh7 liver and HCT116 colon cells in a dose- and time-dependent manner. In addition, cyclin A2 (CCNA2) was identified as a miR-22 novel target in liver and colon cancer cells. The sequence of miR-22, which is conserved in mice, rats, humans, and other mammalians, aligns with the sequence of 3'-UTR of CCNA2. Chenodeoxycholic acid treatment and miR-22 mimics reduced CCNA2 protein and increased the number of G0/G1 Huh7 and HCT116 cells. In FXR KO mice, reduction of miR-22 was accompanied by elevated hepatic and ileal CCNA2 protein, as well as an increased number of hepatic and colonic Ki-67-positive cells. In humans, the expression levels of miR-22 and CCNA2 are inversely correlated in liver and colon cancers. Taken together, our data showed that bile acid-activated FXR stimulates miR-22-silenced CCNA2, a novel pathway for FXR to exert its protective effect in the gastrointestinal tract.
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Affiliation(s)
- Fan Yang
- From the Department of Pathology and Laboratory Medicine, the University of California at Davis Medical Center, Sacramento, California 95817 and the Institute of Chinese Material Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203 China
| | - Ying Hu
- From the Department of Pathology and Laboratory Medicine, the University of California at Davis Medical Center, Sacramento, California 95817 and
| | - Hui-Xin Liu
- From the Department of Pathology and Laboratory Medicine, the University of California at Davis Medical Center, Sacramento, California 95817 and
| | - Yu-Jui Yvonne Wan
- From the Department of Pathology and Laboratory Medicine, the University of California at Davis Medical Center, Sacramento, California 95817 and the Institute of Chinese Material Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203 China
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118
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FXR and liver carcinogenesis. Acta Pharmacol Sin 2015; 36:37-43. [PMID: 25500874 DOI: 10.1038/aps.2014.117] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 09/15/2014] [Indexed: 12/11/2022] Open
Abstract
Farnesoid X receptor (FXR) is a member of the nuclear receptor family and a ligand-modulated transcription factor. In the liver, FXR has been considered a multi-functional cell protector and a tumor suppressor. FXR can suppress liver carcinogenesis via different mechanisms: 1) FXR maintains the normal liver metabolism of bile acids, glucose and lipids; 2) FXR promotes liver regeneration and repair after injury; 3) FXR protects liver cells from death and enhances cell survival; 4) FXR suppresses hepatic inflammation, thereby preventing inflammatory damage; and 5) FXR can directly increase the expression of some tumor-suppressor genes and repress the transcription of several oncogenes. However, inflammation and epigenetic silencing are known to decrease FXR expression during tumorigenesis. The reactivation of FXR function in the liver may be a potential therapeutic approach for patients with liver cancer.
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119
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Joyce SA, Shanahan F, Hill C, Gahan CGM. Bacterial bile salt hydrolase in host metabolism: Potential for influencing gastrointestinal microbe-host crosstalk. Gut Microbes 2014; 5:669-74. [PMID: 25483337 PMCID: PMC4615832 DOI: 10.4161/19490976.2014.969986] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Controlled, reductionist approaches are required in order to obtain a more complete understanding of the functional capabilities of the gut microbiota. We recently identified microbial bile salt hydrolase (BSH) activity as a gut microbial activity that has the capacity to profoundly alter both local (gastrointestinal) and systemic (hepatic) host functions. Using both germ free and conventionally-raised mouse models we demonstrated that gastrointestinal expression of BSH results in local bile acid deconjugation with concomitant alterations in lipid and cholesterol metabolism, signaling functions and weight gain. Key mediators of cholesterol homeostasis (Abcg5/8), gut homeostasis (RegIIIγ) and circadian rhythm (Dbp) were influenced by elevated BSH in our study. In this addendum we discuss the implications of this work for the rational development of probiotics with the potential to modulate host weight gain.
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Affiliation(s)
- Susan A Joyce
- Alimentary Pharmabiotic Centre; University College Cork; Cork, Ireland,School of Medicine; University College Cork; Cork, Ireland
| | - Fergus Shanahan
- Alimentary Pharmabiotic Centre; University College Cork; Cork, Ireland
| | - Colin Hill
- Alimentary Pharmabiotic Centre; University College Cork; Cork, Ireland,School of Microbiology; University College Cork; Cork, Ireland
| | - Cormac GM Gahan
- Alimentary Pharmabiotic Centre; University College Cork; Cork, Ireland,School of Microbiology; University College Cork; Cork, Ireland,School of Pharmacy; University College Cork; Cork, Ireland,Correspondence to: Cormac GM Gahan;
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120
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Anomalies in network bridges involved in bile Acid metabolism predict outcomes of colorectal cancer patients. PLoS One 2014; 9:e107925. [PMID: 25259881 PMCID: PMC4178056 DOI: 10.1371/journal.pone.0107925] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 08/18/2014] [Indexed: 12/21/2022] Open
Abstract
Biomarkers prognostic for colorectal cancer (CRC) would be highly desirable in clinical practice. Proteins that regulate bile acid (BA) homeostasis, by linking metabolic sensors and metabolic enzymes, also called bridge proteins, may be reliable prognostic biomarkers for CRC. Based on a devised metric, "bridgeness," we identified bridge proteins involved in the regulation of BA homeostasis and identified their prognostic potentials. The expression patterns of these bridge proteins could distinguish between normal and diseased tissues, suggesting that these proteins are associated with CRC pathogenesis. Using a supervised classification system, we found that these bridge proteins were reproducibly prognostic, with high prognostic ability compared to other known markers.
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121
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Modica S, Cariello M, Morgano A, Gross I, Vegliante MC, Murzilli S, Salvatore L, Freund JN, Sabbà C, Moschetta A. Transcriptional regulation of the intestinal nuclear bile acid farnesoid X receptor (FXR) by the caudal-related homeobox 2 (CDX2). J Biol Chem 2014; 289:28421-32. [PMID: 25138215 DOI: 10.1074/jbc.m114.571513] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Farnesoid X receptor (FXR, NR1H4) is a bile acid-activated transcription factor that belongs to the nuclear receptor superfamily. It is highly expressed in the enterohepatic system, where it senses bile acid levels to consequently reduce their synthesis while inducing their detoxification. Bile acids are intestinal tumor promoters and their concentrations have to be tightly regulated. Indeed, reduced expression of FXR in the intestine increases colorectal cancer susceptibility in mice, whereas its activation can promote apoptosis in genetically modified cells. Notably, despite the broad knowledge of the FXR enterohepatic transcriptional activity, the molecular mechanisms regulating FXR expression in the intestine are still unknown. Herein, by combining both gain and loss of function approaches and FXR promoter activity studies, we identified caudal-related homeobox 2 (CDX2) transcription factor as a positive regulator of FXR expression in the enterocytes. Our results provide a putative novel tool for modulating FXR expression against bile acid-related colorectal cancer progression.
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Affiliation(s)
- Salvatore Modica
- From the Department of Interdisciplinary Medicine, "Aldo Moro," University of Bari, Bari 70124, Italy, the National Cancer Research Center, IRCCS Oncologico Giovanni Paolo II, 70124 Bari, Italy
| | - Marica Cariello
- the National Cancer Research Center, IRCCS Oncologico Giovanni Paolo II, 70124 Bari, Italy
| | - Annalisa Morgano
- the Laboratory of Lipid Metabolism and Cancer, Consorzio Mario Negri Sud, Santa Maria Imbaro (Chieti), 66030 Italy
| | - Isabelle Gross
- INSERM UMR S1113, 67200 Strasbourg, France, and the Université de Strasbourg, Fédération de Médecine Translationnelle, Strasbourg 67081, France
| | | | - Stefania Murzilli
- the Laboratory of Lipid Metabolism and Cancer, Consorzio Mario Negri Sud, Santa Maria Imbaro (Chieti), 66030 Italy
| | - Lorena Salvatore
- the Laboratory of Lipid Metabolism and Cancer, Consorzio Mario Negri Sud, Santa Maria Imbaro (Chieti), 66030 Italy
| | - Jean-Noel Freund
- INSERM UMR S1113, 67200 Strasbourg, France, and the Université de Strasbourg, Fédération de Médecine Translationnelle, Strasbourg 67081, France
| | - Carlo Sabbà
- From the Department of Interdisciplinary Medicine, "Aldo Moro," University of Bari, Bari 70124, Italy
| | - Antonio Moschetta
- From the Department of Interdisciplinary Medicine, "Aldo Moro," University of Bari, Bari 70124, Italy, the National Cancer Research Center, IRCCS Oncologico Giovanni Paolo II, 70124 Bari, Italy,
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122
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Gadaleta RM, Cariello M, Sabbà C, Moschetta A. Tissue-specific actions of FXR in metabolism and cancer. Biochim Biophys Acta Mol Cell Biol Lipids 2014; 1851:30-9. [PMID: 25139561 DOI: 10.1016/j.bbalip.2014.08.005] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 08/08/2014] [Accepted: 08/11/2014] [Indexed: 12/25/2022]
Abstract
The nuclear Farnesoid X Receptor (FXR) is a transcription factor critically involved in metabolic homeostasis in the gut-liver axis. FXR activity is mediated by hormonal and dietary signals and driven by bile acids (BAs), which are the natural FXR ligands. Given the great physiological importance in BA homeostasis, as well as in the regulation of glucose and lipid metabolism, FXR plays a pivotal role in the pathogenesis of a wide range of disease of the liver, biliary tract and intestine, including hepatic and colorectal cancer. In the last years several studies have shown the relative FXR tissue-specific importance, highlighting synergism and additive effects in the liver and intestine. Gain- and loss-of-FXR-function mouse models have been generated in order to identify the biological processes and the molecular FXR targets. Taking advantage of the knowledge on the structure-activity relationship of BAs for FXR, semi-synthetic and synthetic molecules have been generated to obtain more selective and powerful FXR activators than BAs. This article is part of a Special Issue entitled: Linking transcription to physiology in lipodomics.
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Affiliation(s)
- Raffaella Maria Gadaleta
- Division of Cancer, Imperial Centre for Translational and Experimental Medicine, Imperial College London, UK
| | - Marica Cariello
- National Cancer Research Center, IRCCS Istituto Oncologico "Giovanni Paolo II", Bari, Italy
| | - Carlo Sabbà
- Clinica Medica Frugoni, Department of Interdisciplinary Medicine, University of Bari, Italy
| | - Antonio Moschetta
- National Cancer Research Center, IRCCS Istituto Oncologico "Giovanni Paolo II", Bari, Italy; Clinica Medica Frugoni, Department of Interdisciplinary Medicine, University of Bari, Italy.
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123
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Synthesis and evaluation of 18F-labeled bile acid compound: A potential PET imaging agent for FXR-related diseases. Nucl Med Biol 2014; 41:495-500. [DOI: 10.1016/j.nucmedbio.2014.03.016] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Revised: 02/13/2014] [Accepted: 03/05/2014] [Indexed: 12/11/2022]
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124
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Bishehsari F, Mahdavinia M, Vacca M, Malekzadeh R, Mariani-Costantini R. Epidemiological transition of colorectal cancer in developing countries: Environmental factors, molecular pathways, and opportunities for prevention. World J Gastroenterol 2014; 20:6055-6072. [PMID: 24876728 PMCID: PMC4033445 DOI: 10.3748/wjg.v20.i20.6055] [Citation(s) in RCA: 174] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2013] [Revised: 01/14/2014] [Accepted: 04/16/2014] [Indexed: 02/06/2023] Open
Abstract
Colorectal cancer (CRC) is one of the leading causes of cancer and cancer-related mortality worldwide. The disease has been traditionally a major health problem in industrial countries, however the CRC rates are increasing in the developing countries that are undergoing economic growth. Several environmental risk factors, mainly changes in diet and life style, have been suggested to underlie the rise of CRC in these populations. Diet and lifestyle impinge on nuclear receptors, on the intestinal microbiota and on crucial molecular pathways that are implicated in intestinal carcinogenesis. In this respect, the epidemiological transition in several regions of the world offers a unique opportunity to better understand CRC carcinogenesis by studying the disease phenotypes and their environmental and molecular associations in different populations. The data from these studies may have important implications for the global prevention and treatment of CRC.
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125
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Ajouz H, Mukherji D, Shamseddine A. Secondary bile acids: an underrecognized cause of colon cancer. World J Surg Oncol 2014; 12:164. [PMID: 24884764 PMCID: PMC4041630 DOI: 10.1186/1477-7819-12-164] [Citation(s) in RCA: 247] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Accepted: 05/09/2014] [Indexed: 12/14/2022] Open
Abstract
Bile acids were first proposed as carcinogens in 1939. Since then, accumulated evidence has linked exposure of cells of the gastrointestinal tract to repeated high physiologic levels of bile acids as an important risk factor for gastrointestinal cancers. High exposure to bile acids may occur in a number of settings, but most importantly, is prevalent among individuals who have a high dietary fat intake. A rapid effect on cells of high bile acid exposure is the generation of reactive oxygen species and reactive nitrogen species, disruption of the cell membrane and mitochondria, induction of DNA damage, mutation and apoptosis, and development of reduced apoptosis capability upon chronic exposure. Here, we review the substantial evidence of the mechanism of secondary bile acids and their role in colon cancer.
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Affiliation(s)
- Hana Ajouz
- Department of Hematology/Oncology, American University of Beirut Medical Center, PO Box 11-0236, Riad El Solh, Beirut 1107 2020, Lebanon
| | - Deborah Mukherji
- Department of Hematology/Oncology, American University of Beirut Medical Center, PO Box 11-0236, Riad El Solh, Beirut 1107 2020, Lebanon
| | - Ali Shamseddine
- Department of Hematology/Oncology, American University of Beirut Medical Center, PO Box 11-0236, Riad El Solh, Beirut 1107 2020, Lebanon
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126
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Kong B, Huang J, Zhu Y, Li G, Williams J, Shen S, Aleksunes LM, Richardson JR, Apte U, Rudnick DA, Guo GL. Fibroblast growth factor 15 deficiency impairs liver regeneration in mice. Am J Physiol Gastrointest Liver Physiol 2014; 306:G893-902. [PMID: 24699334 PMCID: PMC4024724 DOI: 10.1152/ajpgi.00337.2013] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Fibroblast growth factor (FGF) 15 (human homolog, FGF19) is an endocrine FGF highly expressed in the small intestine of mice. Emerging evidence suggests that FGF15 is critical for regulating hepatic functions; however, the role of FGF15 in liver regeneration is unclear. This study assessed whether liver regeneration is altered in FGF15 knockout (KO) mice following 2/3 partial hepatectomy (PHx). The results showed that FGF15 KO mice had marked mortality, with the survival rate influenced by genetic background. Compared with wild-type mice, the KO mice displayed extensive liver necrosis and marked elevation of serum bile acids and bilirubin. Furthermore, hepatocyte proliferation was reduced in the KO mice because of impaired cell cycle progression. After PHx, the KO mice had weaker activation of signaling pathways that are important for liver regeneration, including signal transducer and activator of transcription 3, nuclear factor-κB, and mitogen-activated protein kinase. Examination of the KO mice at early time points after PHx revealed a reduced and/or delayed induction of immediate-early response genes, including growth-control transcription factors that are critical for liver regeneration. In conclusion, the results suggest that FGF15 deficiency severely impairs liver regeneration in mice after PHx. The underlying mechanism is likely the result of disrupted bile acid homeostasis and impaired priming of hepatocyte proliferation.
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Affiliation(s)
- Bo Kong
- 1Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, New Jersey;
| | - Jiansheng Huang
- 2Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri;
| | - Yan Zhu
- 3Department of General Surgery, Xuanwu Hospital, Capital Medical University, Beijing, Peoples Republic of China;
| | - Guodong Li
- 4Department of Surgical Oncology, Cancer Treatment Center, Fourth Affiliated Hospital of Harbin Medical University, Harbin, Peoples Republic of China;
| | - Jessica Williams
- 6Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas
| | - Steven Shen
- 6Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas
| | - Lauren M. Aleksunes
- 1Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, New Jersey;
| | - Jason R. Richardson
- 5Department of Environmental and Occupational Medicine, Rutgers Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, New Brunswick, New Jersey; and
| | - Udayan Apte
- 6Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas
| | - David A. Rudnick
- 2Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri;
| | - Grace L. Guo
- 1Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, New Jersey;
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127
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Mroz MS, Keating N, Ward JB, Sarker R, Amu S, Aviello G, Donowitz M, Fallon PG, Keely SJ. Farnesoid X receptor agonists attenuate colonic epithelial secretory function and prevent experimental diarrhoea in vivo. Gut 2014; 63:808-17. [PMID: 23916961 DOI: 10.1136/gutjnl-2013-305088] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
Abstract
OBJECTIVE Bile acids are important regulators of intestinal physiology, and the nuclear bile acid receptor, farnesoid X receptor (FXR), is emerging as a promising therapeutic target for several intestinal disorders. Here, we investigated a role for FXR in regulating intestinal fluid and electrolyte transport and the potential for FXR agonists in treating diarrhoeal diseases. DESIGN Electrogenic ion transport was measured as changes in short-circuit current across voltage-clamped T84 cell monolayers or mouse tissues in Ussing chambers. NHE3 activity was measured as BCECF fluorescence in Caco-2 cells. Protein expression was measured by immunoblotting and cell surface biotinylation. Antidiarrhoeal efficacy of GW4064 was assessed using two in vivo mouse models: the ovalbumin-induced diarrhoea model and cholera toxin (CTX)-induced intestinal fluid accumulation. RESULTS GW4064 (5 μmol/L; 24 h), a specific FXR agonist, induced nuclear translocation of the receptor in T84 cells and attenuated Cl(-) secretory responses to both Ca(2+) and cAMP-dependent agonists. GW4064 also prevented agonist-induced inhibition of NHE3 in Caco-2 cells. In mice, intraperitoneal administration of GW4064 (50 mg/mL) also inhibited Ca(2+) and cAMP-dependent secretory responses across ex vivo colonic tissues and prevented ovalbumin-induced diarrhoea and CTX-induced intestinal fluid accumulation in vivo. At the molecular level, FXR activation attenuated apical Cl(-) currents by inhibiting expression of cystic fibrosis transmembrane conductance regulator channels and inhibited basolateral Na(+)/K(+)-ATPase activity without altering expression of the protein. CONCLUSIONS These data reveal a novel antisecretory role for the FXR in colonic epithelial cells and suggest that FXR agonists have excellent potential for development as a new class of antidiarrheal drugs.
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Affiliation(s)
- Magdalena S Mroz
- Department of Molecular Medicine, RCSI Education and Research Centre, Beaumont Hospital, , Dublin, Ireland
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Ngo Sock ET, Farahnak Z, Lavoie JM. Exercise training decreases gene expression of endo- and xeno-sensors in rat small intestine. Appl Physiol Nutr Metab 2014; 39:1098-103. [PMID: 24933213 DOI: 10.1139/apnm-2013-0573] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The purpose of the study was to test the hypothesis that gene expression of members of the nuclear receptor (NR) superfamily known to act as endo- and xeno-sensors is reduced in the ileum of exercise-trained (Tr) rats. Healthy female rats were either treadmill-trained for 8 weeks, 5 times/week, or remained sedentary (Sed). Training resulted in a significant (p < 0.05) decrease in plasma free fatty acid (0.18 ± 0.01 to 0.15 ± 0.01 mmol/L) and glycerol (24.8 ± 0.8 to 18.7 ± 0.8 mg/L) concentrations. Gene expressions of NRs farnesoid X receptor (FXR; p < 0.05), liver X receptor (LXR; p < 0.05), pregnane X receptor (PXR; p < 0.01), and retinoid X receptor (RXR; p < 0.06) were reduced in the ileum of Tr compared with Sed animals. Tr was also associated with a reduction (p < 0.05) in gene expression of FXR downstream heterodimeric organite solute transporters α (OSTα) and β (OSTβ) involved in the transport of bile acids, LXR downstream genes heterodimeric ATP-binding cassette transporters (ABCG5/G8) involved in transport of absorbed cholesterol back to the lumen, and Niemann-Pick C1-like 1 (NPC1L1) involved in cholesterol absorption. These data indicate that exercise training lowers the expression of molecules involved in the defense system of the ileum against endobiotic and xenobiotic insults under normal conditions, thus, suggesting that regular exercise contributes to the intestinal maintenance of cholesterol and bile acid homeostasis.
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Affiliation(s)
- Emilienne Tudor Ngo Sock
- Department of Kinesiology, Université de Montréal, P.O. Box 6128, Station Centre-ville, Montréal, QC H3C 3J7, Canada
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Singh N, Yadav M, Singh AK, Kumar H, Dwivedi SKD, Mishra JS, Gurjar A, Manhas A, Chandra S, Yadav PN, Jagavelu K, Siddiqi MI, Trivedi AK, Chattopadhyay N, Sanyal S. Synthetic FXR agonist GW4064 is a modulator of multiple G protein-coupled receptors. Mol Endocrinol 2014; 28:659-73. [PMID: 24597548 DOI: 10.1210/me.2013-1353] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The synthetic nuclear bile acid receptor (farnesoid X receptor [FXR]) agonist GW4064 is extensively used as a specific pharmacological tool to illustrate FXR functions. We noticed that GW4064 activated empty luciferase reporters in FXR-deficient HEK-293T cells. We postulated that this activity of GW4064 might be routed through as yet unknown cellular targets and undertook an unbiased exploratory approach to identify these targets. Investigations revealed that GW4064 activated cAMP and nuclear factor for activated T-cell response elements (CRE and NFAT-RE, respectively) present on these empty reporters. Whereas GW4064-induced NFAT-RE activation involved rapid intracellular Ca(2+) accumulation and NFAT nuclear translocation, CRE activation involved soluble adenylyl cyclase-dependent cAMP accumulation and Ca(2+)-calcineurin-dependent nuclear translocation of transducers of regulated CRE-binding protein 2. Use of dominant negative heterotrimeric G-protein minigenes revealed that GW4064 caused activation of Gαi/o and Gq/11 G proteins. Sequential pharmacological inhibitor-based screening and radioligand-binding studies revealed that GW4064 interacted with multiple G protein-coupled receptors. Functional studies demonstrated that GW4064 robustly activated H1 and H4 and inhibited H2 histamine receptor signaling events. We also found that MCF-7 breast cancer cells, reported to undergo GW4064-induced apoptosis in an FXR-dependent manner, did not express FXR, and the GW4064-mediated apoptosis, also apparent in HEK-293T cells, could be blocked by selective histamine receptor regulators. Taken together, our results demonstrate identification of histamine receptors as alternate targets for GW4064, which not only necessitates cautious interpretation of the biological functions attributed to FXR using GW4064 as a pharmacological tool but also provides a basis for the rational designing of new pharmacophores for histamine receptor modulation.
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Affiliation(s)
- Nidhi Singh
- Division of Biochemistry (N.S., M.Y., A.K.S., H.K., J.S.M., A.G., S.S.), Division of Endocrinology and Center for Anabolic Skeletal Targets in Health and Illness (S.K.D.D., N.C.), Division of Pharmacology (A.M., P.N.Y., K.J.), and Division of Molecular and Structural Biology (S.C., M.I.S.), Council of Scientific and Industrial Research-Central Drug Research Institute, Lucknow 226031, Uttar Pradesh, India
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130
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Bailey AM, Zhan L, Maru D, Shureiqi I, Pickering CR, Kiriakova G, Izzo J, He N, Wei C, Baladandayuthapani V, Liang H, Kopetz S, Powis G, Guo GL. FXR silencing in human colon cancer by DNA methylation and KRAS signaling. Am J Physiol Gastrointest Liver Physiol 2014; 306:G48-58. [PMID: 24177031 PMCID: PMC3920083 DOI: 10.1152/ajpgi.00234.2013] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Farnesoid X receptor (FXR) is a bile acid nuclear receptor described through mouse knockout studies as a tumor suppressor for the development of colon adenocarcinomas. This study investigates the regulation of FXR in the development of human colon cancer. We used immunohistochemistry of FXR in normal tissue (n = 238), polyps (n = 32), and adenocarcinomas, staged I-IV (n = 43, 39, 68, and 9), of the colon; RT-quantitative PCR, reverse-phase protein array, and Western blot analysis in 15 colon cancer cell lines; NR1H4 promoter methylation and mRNA expression in colon cancer samples from The Cancer Genome Atlas; DNA methyltransferase inhibition; methyl-DNA immunoprecipitation (MeDIP); bisulfite sequencing; and V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) knockdown assessment to investigate FXR regulation in colon cancer development. Immunohistochemistry and quantitative RT-PCR revealed that expression and function of FXR was reduced in precancerous lesions and silenced in a majority of stage I-IV tumors. FXR expression negatively correlated with phosphatidylinositol-4, 5-bisphosphate 3 kinase signaling and the epithelial-to-mesenchymal transition. The NR1H4 promoter is methylated in ~12% colon cancer The Cancer Genome Atlas samples, and methylation patterns segregate with tumor subtypes. Inhibition of DNA methylation and KRAS silencing both increased FXR expression. FXR expression is decreased early in human colon cancer progression, and both DNA methylation and KRAS signaling may be contributing factors to FXR silencing. FXR potentially suppresses epithelial-to-mesenchymal transition and other oncogenic signaling cascades, and restoration of FXR activity, by blocking silencing mechanisms or increasing residual FXR activity, represents promising therapeutic options for the treatment of colon cancer.
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Affiliation(s)
- Ann M. Bailey
- 1Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, Texas; ,2Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas;
| | - Le Zhan
- 2Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas; ,10Department of Pharmacology and Toxicology, School of Pharmacy, Rutgers University, Piscataway, New Jersey
| | - Dipen Maru
- 3Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas;
| | - Imad Shureiqi
- 4Department of Gastrointestinal (GI) Medical Oncology, Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas;
| | - Curtis R. Pickering
- 5Department of Head and Neck Surgery, University of Texas MD Anderson Cancer Center, Houston, Texas;
| | - Galina Kiriakova
- 1Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, Texas;
| | - Julie Izzo
- 1Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, Texas;
| | - Nan He
- 6Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, Kansas;
| | - Caimiao Wei
- 7Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas;
| | | | - Han Liang
- 8Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas;
| | - Scott Kopetz
- 4Department of Gastrointestinal (GI) Medical Oncology, Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas;
| | - Garth Powis
- 1Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, Texas; ,9Sanford Burnham Medical Research Institute, Cancer Center, La Jolla, California; and
| | - Grace L. Guo
- 2Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas; ,10Department of Pharmacology and Toxicology, School of Pharmacy, Rutgers University, Piscataway, New Jersey
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131
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Li G, Zhu Y, Tawfik O, Kong B, Williams JA, Zhan L, Kassel KM, Luyendyk JP, Wang L, Guo GL. Mechanisms of STAT3 activation in the liver of FXR knockout mice. Am J Physiol Gastrointest Liver Physiol 2013; 305:G829-37. [PMID: 24091600 PMCID: PMC3882431 DOI: 10.1152/ajpgi.00155.2013] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Farnesoid X receptor (FXR, Nr1h4) is a ligand-activated transcription factor belonging to the nuclear receptor superfamily. FXR is essential in maintaining bile acid (BA) homeostasis, and FXR(-/-) mice develop cholestasis, inflammation, and spontaneous liver tumors. The signal transducer and activator of transcription 3 (STAT3) is well known to regulate liver growth, and STAT3 is feedback inhibited by its target gene, the suppressor of cytokine signaling 3 (SOCS3). Strong activation of STAT3 was detected in FXR(-/-) mouse livers. However, the mechanism of STAT3 activation with FXR deficiency remains elusive. Wild-type (WT) and FXR(-/-) mice were used to detect STAT3 pathway activation in the liver. In vivo BA feeding or deprivation was used to determine the role of BAs in STAT3 activation, and in vitro molecular approaches were used to determine the direct transcriptional regulation of SOCS3 by FXR. STAT3 was activated in FXR(-/-) but not WT mice. BA feeding increased, but deprivation by cholestyramine reduced, serum inflammatory markers and STAT3 activation. Furthermore, the Socs3 gene was determined as a direct FXR target gene. The elevated BAs and inflammation, along with reduced SOCS3, collectively contribute to the activation of the STAT3 signaling pathway in the liver of FXR(-/-) mice. This study suggests that the constitutive activation of STAT3 may be a mechanism of liver carcinogenesis in FXR(-/-) mice.
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Affiliation(s)
- Guodong Li
- Dept. of Pharmacology and Toxicology, School of Pharmacy, Rutgers Univ., Piscataway, NJ 08854.
| | - Yan Zhu
- 2Department of Pharmacology and Toxicology, School of Pharmacy, Rutgers University, Piscataway, New Jersey; ,4Department of General Surgery, Xuanwu Hospital, Capital Medical University, Beijing, China;
| | - Ossama Tawfik
- 5Department of Pathology and laboratory Medicine, University of Kansas Medical Center, Kansas City, Kansas;
| | - Bo Kong
- 2Department of Pharmacology and Toxicology, School of Pharmacy, Rutgers University, Piscataway, New Jersey;
| | - Jessica A. Williams
- 3Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas;
| | - Le Zhan
- 2Department of Pharmacology and Toxicology, School of Pharmacy, Rutgers University, Piscataway, New Jersey;
| | - Karen M. Kassel
- 3Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas;
| | - James P. Luyendyk
- 6Pathobiology and Diagnostic Inv., Michigan State University, East Lansing, Michigan; and
| | - Li Wang
- 7Department of Medicine, Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, Utah
| | - Grace L. Guo
- 2Department of Pharmacology and Toxicology, School of Pharmacy, Rutgers University, Piscataway, New Jersey; ,3Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas;
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132
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Madhavan S, Gusev Y, Natarajan TG, Song L, Bhuvaneshwar K, Gauba R, Pandey A, Haddad BR, Goerlitz D, Cheema AK, Juhl H, Kallakury B, Marshall JL, Byers SW, Weiner LM. Genome-wide multi-omics profiling of colorectal cancer identifies immune determinants strongly associated with relapse. Front Genet 2013; 4:236. [PMID: 24312117 PMCID: PMC3834519 DOI: 10.3389/fgene.2013.00236] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Accepted: 10/23/2013] [Indexed: 12/12/2022] Open
Abstract
The use and benefit of adjuvant chemotherapy to treat stage II colorectal cancer (CRC) patients is not well understood since the majority of these patients are cured by surgery alone. Identification of biological markers of relapse is a critical challenge to effectively target treatments to the ~20% of patients destined to relapse. We have integrated molecular profiling results of several "omics" data types to determine the most reliable prognostic biomarkers for relapse in CRC using data from 40 stage I and II CRC patients. We identified 31 multi-omics features that highly correlate with relapse. The data types were integrated using multi-step analytical approach with consecutive elimination of redundant molecular features. For each data type a systems biology analysis was performed to identify pathways biological processes and disease categories most affected in relapse. The biomarkers detected in tumors urine and blood of patients indicated a strong association with immune processes including aberrant regulation of T-cell and B-cell activation that could lead to overall differences in lymphocyte recruitment for tumor infiltration and markers indicating likelihood of future relapse. The immune response was the biologically most coherent signature that emerged from our analyses among several other biological processes and corroborates other studies showing a strong immune response in patients less likely to relapse.
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Affiliation(s)
- Subha Madhavan
- Department of Oncology, Innovation Center for Biomedical Informatics, Georgetown University Medical CenterWashington, DC, USA
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical CenterWashington DC, USA
| | - Yuriy Gusev
- Department of Oncology, Innovation Center for Biomedical Informatics, Georgetown University Medical CenterWashington, DC, USA
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical CenterWashington DC, USA
| | - Thanemozhi G. Natarajan
- Department of Oncology, Innovation Center for Biomedical Informatics, Georgetown University Medical CenterWashington, DC, USA
| | - Lei Song
- Department of Oncology, Innovation Center for Biomedical Informatics, Georgetown University Medical CenterWashington, DC, USA
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical CenterWashington DC, USA
| | - Krithika Bhuvaneshwar
- Department of Oncology, Innovation Center for Biomedical Informatics, Georgetown University Medical CenterWashington, DC, USA
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical CenterWashington DC, USA
| | - Robinder Gauba
- Department of Oncology, Innovation Center for Biomedical Informatics, Georgetown University Medical CenterWashington, DC, USA
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical CenterWashington DC, USA
| | - Abhishek Pandey
- Department of Oncology, Innovation Center for Biomedical Informatics, Georgetown University Medical CenterWashington, DC, USA
| | - Bassem R. Haddad
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical CenterWashington DC, USA
| | - David Goerlitz
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical CenterWashington DC, USA
| | - Amrita K. Cheema
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical CenterWashington DC, USA
| | | | - Bhaskar Kallakury
- Department of Pathology, Lombardi Comprehensive Cancer Center, Georgetown University Medical CenterWashington DC, USA
| | - John L. Marshall
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical CenterWashington DC, USA
| | - Stephen W. Byers
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical CenterWashington DC, USA
| | - Louis M. Weiner
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical CenterWashington DC, USA
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Abstract
Enterohepatic circulation is responsible for the capture of bile acids and other steroids produced or metabolized in the liver and secreted to the intestine, for reabsorption back into the circulation and transport back to the liver. Bile acids are secreted from the liver in the form of mixed micelles that also contain phosphatidylcholines and cholesterol that facilitate the uptake of fats and vitamins from the diet due to the surfactant properties of bile acids and lipids. Bile acids are synthesized in the liver from cholesterol by a cascade of enzymes that carry out oxidation and conjugation reactions, and transported to the bile duct and gall bladder where they are stored before being released into the intestine. Bile flow from the gall bladder to the small intestine is triggered by food intake in accordance with its role in lipid and vitamin absorption from the diet. Bile acids are further metabolized by gut bacteria and are transported back to the circulation. Metabolites produced in the liver are termed primary bile acids or primary conjugated bile salts, while the metabolites generated by bacterial are called secondary bile acids. About 95% of bile acids are reabsorbed in the proximal and distal ileum into the hepatic portal vein and then into the liver sinusoids, where they are efficiently transported into the liver with little remaining in circulation. Each bile acid is reabsorbed about 20 times on average before being eliminated. Enterohepatic circulation is under tight regulation by nuclear receptor signaling, notably by the farnesoid X receptor (FXR).
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Affiliation(s)
- Frank J Gonzalez
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA.
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134
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Li G, Kong B, Zhu Y, Zhan L, Williams JA, Tawfik O, Kassel KM, Luyendyk JP, Wang L, Guo GL. Small heterodimer partner overexpression partially protects against liver tumor development in farnesoid X receptor knockout mice. Toxicol Appl Pharmacol 2013; 272:299-305. [PMID: 23811326 DOI: 10.1016/j.taap.2013.06.016] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Revised: 06/10/2013] [Accepted: 06/17/2013] [Indexed: 02/07/2023]
Abstract
Farnesoid X receptor (FXR, Nr1h4) and small heterodimer partner (SHP, Nr0b2) are nuclear receptors that are critical to liver homeostasis. Induction of SHP serves as a major mechanism of FXR in suppressing gene expression. Both FXR(-/-) and SHP(-/-) mice develop spontaneous hepatocellular carcinoma (HCC). SHP is one of the most strongly induced genes by FXR in the liver and is a tumor suppressor, therefore, we hypothesized that deficiency of SHP contributes to HCC development in the livers of FXR(-/-) mice and therefore, increased SHP expression in FXR(-/-) mice reduces liver tumorigenesis. To test this hypothesis, we generated FXR(-/-) mice with overexpression of SHP in hepatocytes (FXR(-/-)/SHP(Tg)) and determined the contribution of SHP in HCC development in FXR(-/-) mice. Hepatocyte-specific SHP overexpression did not affect liver tumor incidence or size in FXR(-/-) mice. However, SHP overexpression led to a lower grade of dysplasia, reduced indicator cell proliferation and increased apoptosis. All tumor-bearing mice had increased serum bile acid levels and IL-6 levels, which was associated with activation of hepatic STAT3. In conclusion, SHP partially protects FXR(-/-) mice from HCC formation by reducing tumor malignancy. However, disrupted bile acid homeostasis by FXR deficiency leads to inflammation and injury, which ultimately results in uncontrolled cell proliferation and tumorigenesis in the liver.
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Affiliation(s)
- Guodong Li
- Department of Surgical Oncology, Cancer Treatment Center, The Fourth Affiliated Hospital of Harbin Medical University, Harbin, China
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135
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Bjursell M, Wedin M, Admyre T, Hermansson M, Böttcher G, Göransson M, Lindén D, Bamberg K, Oscarsson J, Bohlooly-Y M. Ageing Fxr deficient mice develop increased energy expenditure, improved glucose control and liver damage resembling NASH. PLoS One 2013; 8:e64721. [PMID: 23700488 PMCID: PMC3659114 DOI: 10.1371/journal.pone.0064721] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Accepted: 04/17/2013] [Indexed: 12/17/2022] Open
Abstract
Nuclear receptor subfamily 1, group H, member 4 (Nr1h4, FXR) is a bile acid activated nuclear receptor mainly expressed in the liver, intestine, kidney and adrenal glands. Upon activation, the primary function is to suppress cholesterol 7 alpha-hydroxylase (Cyp7a1), the rate-limiting enzyme in the classic or neutral bile acid synthesis pathway. In the present study, a novel Fxr deficient mouse line was created and studied with respect to metabolism and liver function in ageing mice fed chow diet. The Fxr deficient mice were similar to wild type mice in terms of body weight, body composition, energy intake and expenditure as well as behaviours at a young age. However, from 15 weeks of age and onwards, the Fxr deficient mice had almost no body weight increase up to 39 weeks of age mainly because of lower body fat mass. The lower body weight gain was associated with increased energy expenditure that was not compensated by increased food intake. Fasting levels of glucose and insulin were lower and glucose tolerance was improved in old and lean Fxr deficient mice. However, the Fxr deficient mice displayed significantly increased liver weight, steatosis, hepatocyte ballooning degeneration and lobular inflammation together with elevated plasma levels of ALT, bilirubin and bile acids, findings compatible with non-alcoholic steatohepatitis (NASH) and cholestasis. In conclusion, ageing Fxr deficient mice display late onset leanness associated with elevated energy expenditure and improved glucose control but develop severe NASH-like liver pathology.
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136
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Matsubara T, Li F, Gonzalez FJ. FXR signaling in the enterohepatic system. Mol Cell Endocrinol 2013; 368:17-29. [PMID: 22609541 PMCID: PMC3491147 DOI: 10.1016/j.mce.2012.05.004] [Citation(s) in RCA: 250] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Revised: 04/18/2012] [Accepted: 05/08/2012] [Indexed: 02/07/2023]
Abstract
Enterohepatic circulation serves to capture bile acids and other steroid metabolites produced in the liver and secreted to the intestine, for reabsorption back into the circulation and reuptake to the liver. This process is under tight regulation by nuclear receptor signaling. Bile acids, produced from cholesterol, can alter gene expression in the liver and small intestine via activating the nuclear receptors farnesoid X receptor (FXR; NR1H4), pregnane X receptor (PXR; NR1I2), vitamin D receptor (VDR; NR1I1), G protein coupled receptor TGR5, and other cell signaling pathways (JNK1/2, AKT and ERK1/2). Among these controls, FXR is known to be a major bile acid-responsive ligand-activated transcription factor and a crucial control element for maintaining bile acid homeostasis. FXR has a high affinity for several major endogenous bile acids, notably cholic acid, deoxycholic acid, chenodeoxycholic acid, and lithocholic acid. By responding to excess bile acids, FXR is a bridge between the liver and small intestine to control bile acid levels and regulate bile acid synthesis and enterohepatic flow. FXR is highly expressed in the liver and gut, relative to other tissues, and contributes to the maintenance of cholesterol/bile acid homeostasis by regulating a variety of metabolic enzymes and transporters. FXR activation also affects lipid and glucose metabolism, and can influence drug metabolism.
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Affiliation(s)
- Tsutomu Matsubara
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Fei Li
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Frank J. Gonzalez
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
- Correspondence: Frank J. Gonzalez, Laboratory of Metabolism, National Cancer Institute, Building 37, Room 3106, Bethesda, MD 20892, Tel: 301-496-9067, Fax: 301-496-8419,
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137
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Hepatocyte nuclear factor 4 alpha and farnesoid X receptor co-regulates gene transcription in mouse livers on a genome-wide scale. Pharm Res 2013; 30:2188-98. [PMID: 23462932 DOI: 10.1007/s11095-013-1006-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2012] [Accepted: 02/06/2013] [Indexed: 01/06/2023]
Abstract
PURPOSE Farnesoid X receptor (Fxr) is a ligand-activated nuclear receptor critical for liver function. Reports indicate that the functions of Fxr in the liver may overlap with those of hepatocyte nuclear factor 4α (Hnf4α), but studies of their precise genome-wide interaction to regulate gene transcription in the liver are lacking. Thus, we compared the genome-wide binding of Fxr and Hnf4α in the liver of mice and characterized their cooperative activity on binding to and activating target gene transcription. METHODS Genome-wide ChIP-Seq data of Fxr and Hnf4α in mouse liver were analyzed by MACS, BEDTools, and DAVID. Co-immunoprecipitation, ChIP-qPCR, and luciferase assays were done to test for protein-protein interaction and cooperative binding. RESULTS ChIP-seq analysis showed nearly 50% binding sites of Fxr and Hnf4α in mouse liver overlap and Hnf4α bound to shared target sites upstream and in close proximity to Fxr. Moreover, genes co-bound by Fxr and Hnf4α are enriched in complement and coagulation cascades and drug metabolism. A direct Fxr-Hnf4α protein interaction dependent on Fxr activity was detected and transcriptional assays suggest that Hnf4α can increase Fxr transcriptional activity. Conversely, binding assays showed Hnf4α can be either Fxr-dependent or -independent at different shared binding sites. CONCLUSION Our results showed that Fxr cooperates with Hnf4α in the liver to modulate gene transcription. This study provides the first evidence on a genome-wide scale of both cooperative and independent interactions between Fxr and Hnf4α in regulating gene transcription in the liver.
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138
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Farnesoid X receptor expression is decreased in colonic mucosa of patients with primary sclerosing cholangitis and colitis-associated neoplasia. Inflamm Bowel Dis 2013; 19:275-82. [PMID: 23348121 DOI: 10.1097/mib.0b013e318286ff2e] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND The expression and distribution of farnesoid X receptor (FXR) in colitis and colitis-associated neoplasia (CAN) is unknown. We investigated FXR expression in neoplastic and nonneoplastic tissue from ulcerative colitis (UC) patients, with or without primary sclerosing cholangitis (PSC), as well as the role of DNA methylation in FXR expression in colorectal cancer (CRC) cell lines. METHODS Samples from the right (RC) and left (LC) colon of patients with UC, with and without PSC, and with or without CAN, were stained by immunohistochemistry and scored semiquantitatively for nuclear FXR expression. FXR expression was analyzed by western blot and polymerase chain reaction (PCR) in nine different CRC cell lines before and after demethylation with 5-azacytidine. RESULTS In nondysplastic samples, FXR expression demonstrated a diminishing expression from proximal to distal colon (strong FXR expression: 39% RC samples vs. 14% LC samples; P = 0.007). With moderate-to-severe inflammation, FXR expression was almost always absent or weak in both UC and PSC-UC, regardless of location. With quiescent/mild inflammation, 56% of UC samples in the RC retained strong FXR expression versus 24% of PSC-UC samples (P= 0.017). FXR was absent in 72% of the neoplastic samples, with an inverse association with the grade of dysplasia. FXR expression was absent in all CRC cell lines, in some cases due to DNA methylation. CONCLUSIONS FXR expression is inversely correlated with neoplastic progression and severity of inflammation in UC. Patients with PSC-UC have diminished FXR expression in the proximal colon compared to UC patients. This finding could contribute to the higher risk of proximal neoplasia in PSC patients.
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139
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Dong J, Jin G, Wu C, Guo H, Zhou B, Lv J, Lu D, Shi Y, Shu Y, Xu L, Chu M, Wang C, Zhang R, Dai J, Jiang Y, Yu D, Ma H, Zhao X, Yin Z, Yang L, Li Z, Deng Q, Cao S, Qin Z, Gong J, Sun C, Wang J, Wu W, Zhou G, Chen H, Guan P, Chen Y, Liu X, Liu L, Xu P, Han B, Bai C, Zhao Y, Zhang H, Yan Y, Liu J, Amos CI, Chen F, Tan W, Jin L, Wu T, Hu Z, Lin D, Shen H. Genome-wide association study identifies a novel susceptibility locus at 12q23.1 for lung squamous cell carcinoma in han chinese. PLoS Genet 2013; 9:e1003190. [PMID: 23341777 PMCID: PMC3547794 DOI: 10.1371/journal.pgen.1003190] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Accepted: 11/01/2012] [Indexed: 12/20/2022] Open
Abstract
Adenocarcinoma (AC) and squamous cell carcinoma (SqCC) are two major histological subtypes of lung cancer. Genome-wide association studies (GWAS) have made considerable advances in the understanding of lung cancer susceptibility. Obvious heterogeneity has been observed between different histological subtypes of lung cancer, but genetic determinants in specific to lung SqCC have not been systematically investigated. Here, we performed the GWAS analysis specifically for lung SqCC in 833 SqCC cases and 3,094 controls followed by a two-stage replication in additional 2,223 lung SqCC cases and 6,409 controls from Chinese populations. We found that rs12296850 in SLC17A8-NR1H4 gene region at12q23.1 was significantly associated with risk of lung SqCC at genome-wide significance level [additive model: odds ratio (OR) = 0.78, 95% confidence interval (CI) = 0.72–0.84, P = 1.19×10−10]. Subjects carrying AG or GG genotype had a 26% (OR = 0.74, 95% CI = 0.67–0.81) or 32% (OR = 0.68, 95% CI = 0.56–0.83) decreased risk of lung SqCC, respectively, as compared with AA genotype. However, we did not observe significant association between rs12296850 and risk of lung AC in a total of 4,368 cases with lung AC and 9,486 controls (OR = 0.96, 95% CI = 0.90–1.02, P = 0.173). These results indicate that genetic variations on chromosome 12q23.1 may specifically contribute to lung SqCC susceptibility in Chinese population. Previous genome-wide association studies (GWAS) strongly suggested the importance of genetic susceptibility for lung cancer. However, the studies specific to different histological subtypes of lung cancer were limited. We performed the GWAS analysis specifically for lung squamous cell carcinoma (SqCC) with 570,009 autosomal SNPs in 833 SqCC cases and 3,094 controls and replicated in additional 2,223 lung SqCC cases and 6,409 controls from Chinese populations (822 SqCC cases and 2,243 controls for the first replication stage and 1,401 SqCC cases and 4,166 controls for the second replication stage). We found a novel association at rs12296850 (SLC17A8-NR1H4) on12q23.1. However, rs12296850 didn't show significant association with risk of lung adenocacinoma (AC) in 4,368 lung AC cases and 9,486 controls. These results indicate that genetic variations on chromosome 12q23.1 may specifically contribute to lung SqCC susceptibility in Chinese population.
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Affiliation(s)
- Jing Dong
- Department of Epidemiology and Biostatistics and Ministry of Education (MOE) Key Lab for Modern Toxicology, School of Public Health, Nanjing Medical University, Nanjing, China
- Section of Clinical Epidemiology, Jiangsu Key Laboratory of Cancer Biomarkers, Prevention, and Treatment, Cancer Center, Nanjing Medical University, Nanjing, China
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, China
| | - Guangfu Jin
- Department of Epidemiology and Biostatistics and Ministry of Education (MOE) Key Lab for Modern Toxicology, School of Public Health, Nanjing Medical University, Nanjing, China
- Section of Clinical Epidemiology, Jiangsu Key Laboratory of Cancer Biomarkers, Prevention, and Treatment, Cancer Center, Nanjing Medical University, Nanjing, China
| | - Chen Wu
- State Key Laboratory of Molecular Oncology and Department of Etiology and Carcinogenesis, Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Huan Guo
- Institute of Occupational Medicine and Ministry of Education Key Laboratory for Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Baosen Zhou
- Department of Epidemiology, School of Public Health, China Medical University, Shenyang, China
| | - Jiachun Lv
- The Institute for Chemical Carcinogenesis, State Key Laboratory of Respiratory Disease, Guangzhou Medical College, Guangzhou, China
| | - Daru Lu
- State Key Laboratory of Genetic Engineering, Center for Fudan–VARI Genetic Epidemiology and MOE Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, China
| | - Yongyong Shi
- Bio-X Center and Affiliated Changning Mental Health Center, Ministry of Education Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Shanghai JiaoTong University, Shanghai, China
| | - Yongqian Shu
- Department of Thoracic Surgery and Oncology, First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Lin Xu
- Department of Thoracic Surgery, Affiliated Cancer Hospital of Nanjing Medical University, Jiangsu Cancer Hospital, Nanjing, China
| | - Minjie Chu
- Department of Epidemiology and Biostatistics and Ministry of Education (MOE) Key Lab for Modern Toxicology, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Cheng Wang
- Department of Epidemiology and Biostatistics and Ministry of Education (MOE) Key Lab for Modern Toxicology, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Ruyang Zhang
- Department of Epidemiology and Biostatistics and Ministry of Education (MOE) Key Lab for Modern Toxicology, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Juncheng Dai
- Department of Epidemiology and Biostatistics and Ministry of Education (MOE) Key Lab for Modern Toxicology, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Yue Jiang
- Department of Epidemiology and Biostatistics and Ministry of Education (MOE) Key Lab for Modern Toxicology, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Dianke Yu
- State Key Laboratory of Molecular Oncology and Department of Etiology and Carcinogenesis, Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Hongxia Ma
- Department of Epidemiology and Biostatistics and Ministry of Education (MOE) Key Lab for Modern Toxicology, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Xueying Zhao
- State Key Laboratory of Genetic Engineering, Center for Fudan–VARI Genetic Epidemiology and MOE Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, China
| | - Zhihua Yin
- Department of Epidemiology, School of Public Health, China Medical University, Shenyang, China
| | - Lei Yang
- The Institute for Chemical Carcinogenesis, State Key Laboratory of Respiratory Disease, Guangzhou Medical College, Guangzhou, China
| | - Zhiqiang Li
- Bio-X Center and Affiliated Changning Mental Health Center, Ministry of Education Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Shanghai JiaoTong University, Shanghai, China
| | - Qifei Deng
- Institute of Occupational Medicine and Ministry of Education Key Laboratory for Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Songyu Cao
- Department of Epidemiology and Biostatistics and Ministry of Education (MOE) Key Lab for Modern Toxicology, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Zhenzhen Qin
- Department of Epidemiology and Biostatistics and Ministry of Education (MOE) Key Lab for Modern Toxicology, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Jianhang Gong
- Department of Epidemiology and Biostatistics and Ministry of Education (MOE) Key Lab for Modern Toxicology, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Chongqi Sun
- Department of Epidemiology and Biostatistics and Ministry of Education (MOE) Key Lab for Modern Toxicology, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Jiucun Wang
- State Key Laboratory of Genetic Engineering, Center for Fudan–VARI Genetic Epidemiology and MOE Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, China
| | - Wei Wu
- Department of Epidemiology, School of Public Health, China Medical University, Shenyang, China
| | - Guoquan Zhou
- Bio-X Center and Affiliated Changning Mental Health Center, Ministry of Education Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Shanghai JiaoTong University, Shanghai, China
| | - Hongyan Chen
- State Key Laboratory of Genetic Engineering, Center for Fudan–VARI Genetic Epidemiology and MOE Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, China
| | - Peng Guan
- Department of Epidemiology, School of Public Health, China Medical University, Shenyang, China
| | - Yijiang Chen
- Department of Thoracic Surgery and Oncology, First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Xiangyang Liu
- Department of Thoracic Surgery, Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Li Liu
- Cancer Center of Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Pin Xu
- Department of Oncology, Wuhan Iron and Steel Group/Corporation Staff-Worker Hospital, Wuhan, China
| | - Baohui Han
- Department of Respiratory Disease, Shanghai Chest Hospital, Shanghai Jiaotong University, Shanghai, China
| | - Chunxue Bai
- Department of Respiratory Disease, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yuxia Zhao
- Department of Radiation Oncology, First Affiliated Hospital of China Medical University, Shenyang, China
| | - Haibo Zhang
- Department of Radiotherapy, Shenyang Northern Hospital, Shenyang, China
| | - Ying Yan
- Department of Radiotherapy, Shenyang Northern Hospital, Shenyang, China
| | - Jibin Liu
- Department of Surgery, Nantong Cancer Hospital, Nantong, China
| | - Christopher I. Amos
- Department of Genetics, University of Texas M. D. Anderson Cancer Center, Houston, Texas, United States of America
| | - Feng Chen
- Department of Epidemiology and Biostatistics and Ministry of Education (MOE) Key Lab for Modern Toxicology, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Wen Tan
- State Key Laboratory of Molecular Oncology and Department of Etiology and Carcinogenesis, Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Li Jin
- State Key Laboratory of Genetic Engineering, Center for Fudan–VARI Genetic Epidemiology and MOE Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, China
| | - Tangchun Wu
- Institute of Occupational Medicine and Ministry of Education Key Laboratory for Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zhibin Hu
- Department of Epidemiology and Biostatistics and Ministry of Education (MOE) Key Lab for Modern Toxicology, School of Public Health, Nanjing Medical University, Nanjing, China
- Section of Clinical Epidemiology, Jiangsu Key Laboratory of Cancer Biomarkers, Prevention, and Treatment, Cancer Center, Nanjing Medical University, Nanjing, China
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, China
- * E-mail: (Z Hu); (D Lin); (H Shen)
| | - Dongxin Lin
- State Key Laboratory of Molecular Oncology and Department of Etiology and Carcinogenesis, Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- * E-mail: (Z Hu); (D Lin); (H Shen)
| | - Hongbing Shen
- Department of Epidemiology and Biostatistics and Ministry of Education (MOE) Key Lab for Modern Toxicology, School of Public Health, Nanjing Medical University, Nanjing, China
- Section of Clinical Epidemiology, Jiangsu Key Laboratory of Cancer Biomarkers, Prevention, and Treatment, Cancer Center, Nanjing Medical University, Nanjing, China
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, China
- * E-mail: (Z Hu); (D Lin); (H Shen)
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Abstract
Bile acids (BAs) are not only facilitators participating in the absorption of dietary lipids and soluble vitamins, but are also important signaling molecules exerting versatile biophysiological effects. Three major signaling pathways, including the MAPK pathways, the nuclear hormone receptor farnesoid X receptor a-mediated pathways and the G protein-coupled receptor TGR5/M-BAR-mediated pathways, have been identified to be the targets of BAs. BAs, the biologically many-sided and toxic molecules, regulate the homeostasis of themselves via these signaling pathways. BAs also affect diverse metabolic status including glucose metabolism, lipid metabolism, energy expenditure, immunity and others. BAs and their related signaling mechanisms are attractive therapeutic targets of various diseases such as metabolic syndrome.
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Affiliation(s)
- Kohkichi Morimoto
- a Division of Endocrinology, Metabolism and Nephrology, Department of Internal Medicine, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
| | - Hiroshi Itoh
- a Division of Endocrinology, Metabolism and Nephrology, Department of Internal Medicine, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
- b Graduate School of Media and Governance, Faculty of Environment and Information Studies, Keio University, 5322 Endo, Fujisawa, Kanagawa 252-0882, Japan.
| | - Mitsuhiro Watanabe
- a Division of Endocrinology, Metabolism and Nephrology, Department of Internal Medicine, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
- b Graduate School of Media and Governance, Faculty of Environment and Information Studies, Keio University, 5322 Endo, Fujisawa, Kanagawa 252-0882, Japan.
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141
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Barrasa JI, Olmo N, Lizarbe MA, Turnay J. Bile acids in the colon, from healthy to cytotoxic molecules. Toxicol In Vitro 2012; 27:964-77. [PMID: 23274766 DOI: 10.1016/j.tiv.2012.12.020] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Revised: 12/10/2012] [Accepted: 12/20/2012] [Indexed: 02/07/2023]
Abstract
Bile acids are natural detergents mainly involved in facilitating the absorption of dietary fat in the intestine. In addition to this absorptive function, bile acids are also essential in the maintenance of the intestinal epithelium homeostasis. To accomplish this regulatory function, bile acids may induce programmed cell death fostering the renewal of the epithelium. Here we first discuss on the different molecular pathways of cell death focusing on apoptosis in colon epithelial cells. Bile acids may induce apoptosis in colonocytes through different mechanisms. In contrast to hepatocytes, the extrinsic apoptotic pathway seems to have a low relevance regarding bile acid cytotoxicity in the colon. On the contrary, these molecules mainly trigger apoptosis through direct or indirect mitochondrial perturbations, where oxidative stress plays a key role. In addition, bile acids may also act as regulatory molecules involved in different cell signaling pathways in colon cells. On the other hand, there is increasing evidence that the continuous exposure to certain hydrophobic bile acids, due to a fat-rich diet or pathological conditions, may induce oxidative DNA damage that, in turn, may lead to colorectal carcinogenesis as a consequence of the appearance of cell populations resistant to bile acid-induced apoptosis. Finally, some bile acids, such as UDCA, or low concentrations of hydrophobic bile acids, can protect colon cells against apoptosis induced by high concentrations of cytotoxic bile acids, suggesting a dual behavior of these agents as pro-death or pro-survival molecules.
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Affiliation(s)
- Juan I Barrasa
- Department of Biochemistry and Molecular Biology I, Faculty of Chemistry, Complutense University, 28040 Madrid, Spain
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142
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Zhu Y, Li G, Dong Y, Zhou HH, Kong B, Aleksunes LM, Richardson JR, Li F, Guo GL. Modulation of farnesoid X receptor results in post-translational modification of poly (ADP-ribose) polymerase 1 in the liver. Toxicol Appl Pharmacol 2012. [PMID: 23178280 DOI: 10.1016/j.taap.2012.11.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The farnesoid X receptor (FXR) is a bile acid-activated transcription factor belonging to the nuclear receptor superfamily. FXR deficiency in mice results in cholestasis, metabolic disorders, and tumorigenesis in liver and intestine. FXR is known to contribute to pathogenesis by regulating gene transcription; however, changes in the post-transcriptional modification of proteins associated with FXR modulation have not been determined. In the current study, proteomic analysis of the livers of wild-type (WT) and FXR knockout (FXR-KO) mice treated with a FXR synthetic ligand or vehicle was performed. The results identified five proteins as novel FXR targets. Since FXR deficiency in mice leads to liver tumorigenesis, poly (ADP-ribose) polymerase family, member 1 (Parp1) that is important for DNA repair, was validated in the current study by quantitative real-time PCR, and 1- and 2-dimensional gel electrophoresis/western blot. The results showed that Parp1 mRNA levels were not altered by FXR genetic status or by agonist treatment. However, total Parp1 protein levels were increased in FXR-KO mice as early as 3 month old. Interestingly, total Parp1 protein levels were increased in WT mice in an age-dependent manner (from 3 to 18 months), but not in FXR-KO mice. Finally, activation of FXR in WT mice resulted in reduction of phosporylated Parp1 protein in the liver without affecting total Parp1 protein levels. In conclusion, this study reveals that FXR genetic status and agonist treatment affects basal levels and phosphorylation state of Parp1, respectively. These alterations, in turn, may be associated with the hepatobiliary alterations observed in FXR-KO mice and participate in FXR agonist-induced protection in the liver.
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Affiliation(s)
- Yan Zhu
- Department of General Surgery, Xuanwu Hospital, Capital Medical University, Beijing, PR China
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143
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Catalano S, Panza S, Malivindi R, Giordano C, Barone I, Bossi G, Lanzino M, Sirianni R, Mauro L, Sisci D, Bonofiglio D, Andò S. Inhibition of Leydig tumor growth by farnesoid X receptor activation: the in vitro and in vivo basis for a novel therapeutic strategy. Int J Cancer 2012; 132:2237-47. [PMID: 23124354 DOI: 10.1002/ijc.27915] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Accepted: 10/10/2012] [Indexed: 11/12/2022]
Abstract
Leydig cell tumors (LCTs) are the most common tumors of the gonadal stroma and represent about 3% of all testicular neoplasms. In most cases, LCTs are benign; however, if the tumor is malignant, no effective treatments are currently available. We have recently reported that farnesoid X receptor (FXR) is expressed in R2C Leydig tumor cells, and it reduces the estrogen-dependent cell proliferation by negatively regulating aromatase expression. Here, we demonstrated that treatment with GW4064, a specific FXR agonist, markedly reduced Leydig tumor growth in vivo by inhibiting proliferation and inducing apoptosis. Indeed, the tumors from GW4064-treated mice exhibited a decrease in the expression of the proliferation marker Ki-67 and aromatase along with an increase in the apoptotic nuclei. FXR activation induced an enhanced poly(ADP-ribose) polymerase cleavage, a marked DNA fragmentation and a strong increase in TUNEL-positive R2C cells also in vitro. Moreover, in both in vivo and in vitro models, FXR ligands upregulated mRNA and protein levels of p53 and of its downstream effector p21(WAF1/Cip1) . Functional experiments showed that FXR ligands upregulated p53 promoter activity and this occurred through an increased binding of FXR/nuclear factor-kB (NF-kB) complex to the NF-kB site located within p53 promoter region as revealed by electrophoretic mobility shift assay and chromatin immunoprecipitation analysis. Taken together, results from our study show, for the first time, that treatment with FXR ligands induces Leydig tumor regression in vivo, suggesting that activation of FXR may represent a promising therapeutic strategy for LCTs.
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Affiliation(s)
- Stefania Catalano
- Department of Pharmaco-Biology, University of Calabria, Arcavacata di Rende (CS), Italy.
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144
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Peng Z, Raufman JP, Xie G. Src-mediated cross-talk between farnesoid X and epidermal growth factor receptors inhibits human intestinal cell proliferation and tumorigenesis. PLoS One 2012; 7:e48461. [PMID: 23119029 PMCID: PMC3485230 DOI: 10.1371/journal.pone.0048461] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 09/26/2012] [Indexed: 12/11/2022] Open
Abstract
Besides its essential role in controlling bile acid and lipid metabolism, the farnesoid X receptor (FXR) protects against intestinal tumorigenesis by promoting apoptosis and inhibiting cell proliferation. However, the mechanisms underlying these anti-proliferative actions of FXR remain to be elucidated. In the present study, we examined the effects of FXR activation (FXR overexpression and treatment with an FXR agonist GW4064) and inactivation (treatment with FXR siRNA and an FXR antagonist guggulsterone) on colon cancer cell proliferation in vitro using human colon cancer cell lines (H508, SNU-C4 and HT-29) and in vivo using xenografts in nude mice. Blocking FXR activity with guggulsterone stimulated time- and dose-dependent EGFR (Tyr845) phosphorylation and ERK activation. In contrast, FXR overexpression and activation with GW4064 attenuated cell proliferation by down-regulating EGFR (Tyr845) phosphorylation and ERK activation. Treatment with guggulsterone and GW4064 also caused dose-dependent changes in Src (Tyr416) phosphorylation. In stably-transfected human colon cancer cells, overexpression of FXR reduced EGFR, ERK, Src phosphorylation and cell proliferation, and in nude mice attenuated the growth of human colon cancer xenografts (64% reduction in tumor volume; 47% reduction in tumor weight; both P<0.01). Moreover, guggulsterone-induced EGFR and ERK phosphorylation and cell proliferation were abolished by inhibiting activation of Src, EGFR and MEK. Collectively these data support the novel conclusion that in human colon cancer cells Src-mediated cross-talk between FXR and EGFR modulates ERK phosphorylation, thereby regulating intestinal cell proliferation and tumorigenesis.
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Affiliation(s)
- Zhongsheng Peng
- Division of Gastroenterology and Hepatology, VA Maryland Health Care System, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Jean-Pierre Raufman
- Division of Gastroenterology and Hepatology, VA Maryland Health Care System, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Guofeng Xie
- Division of Gastroenterology and Hepatology, VA Maryland Health Care System, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- * E-mail:
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145
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FXR controls the tumor suppressor NDRG2 and FXR agonists reduce liver tumor growth and metastasis in an orthotopic mouse xenograft model. PLoS One 2012; 7:e43044. [PMID: 23056173 PMCID: PMC3467263 DOI: 10.1371/journal.pone.0043044] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Accepted: 07/16/2012] [Indexed: 02/06/2023] Open
Abstract
The farnesoid X receptor (FXR) is expressed predominantly in tissues exposed to high levels of bile acids and controls bile acid and lipid homeostasis. FXR−/− mice develop hepatocellular carcinoma (HCC) and show an increased prevalence for intestinal malignancies, suggesting a role of FXR as a tumor suppressor in enterohepatic tissues. The N-myc downstream-regulated gene 2 (NDRG2) has been recognized as a tumor suppressor gene, which is downregulated in human hepatocellular carcinoma, colorectal carcinoma and many other malignancies. We show reduced NDRG2 mRNA in livers of FXR−/− mice compared to wild type mice and both, FXR and NDRG2 mRNAs, are reduced in human HCC compared to normal liver. Gene reporter assays and Chromatin Immunoprecipitation data support that FXR directly controls NDRG2 transcription via IR1-type element(s) identified in the first introns of the human, mouse and rat NDRG2 genes. NDRG2 mRNA was induced by non-steroidal FXR agonists in livers of mice and the magnitude of induction of NDRG2 mRNA in three different human hepatoma cell lines was increased when ectopically expressing human FXR. Growth and metastasis of SK-Hep-1 cells was strongly reduced by non-steroidal FXR agonists in an orthotopic liver xenograft tumor model. Ectopic expression of FXR in SK-Hep1 cells reduced tumor growth and metastasis potential of corresponding cells and increased the anti-tumor efficacy of FXR agonists, which may be partly mediated via increased NDRG2 expression. FXR agonists may show a potential in the prevention and/or treatment of human hepatocellular carcinoma, a devastating malignancy with increasing prevalence and limited therapeutic options.
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146
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Abstract
Colorectal cancer is the third and second most common cancer among men and women, respectively, in France. Interest in the chemoprevention of colorectal cancer has increased over the last two decades. Experimental data strongly suggest that ursodeoxycholic acid (UDCA) may have chemopreventative actions in colorectal cancer. UDCA is able to inhibit tumor development in azoxymethane and in dextran-related colitis models. In high-risk populations such as subjects with previous colorectal adenoma removal or inflammatory bowel disease, five out of 10 published studies suggested beneficial effects with UDCA on colonic carcinogenesis. In the azoxymethane model, UDCA inhibited tumor development by counteracting the tumor-promoting effects of secondary bile acids such as deoxycholic acid (DCA). The opposing effects of UDCA and DCA on lipid raft composition may be central to their effects on colonic tumorigenesis. Differential effects of DCA and UDCA on growth factor and inflammatory signals involved in colorectal carcinogenesis, such as epidermal growth factor receptor (EGFR) signaling and COX-2 expression, very likely mediate their opposing effects on colonic tumor promotion and tumor inhibition, respectively.
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Affiliation(s)
- Lawrence Serfaty
- Service d'Hépatologie, Hôpital Saint-Antoine, 184 Rue du Faubourg Saint-Antoine, 75571 Paris Cedex 12, France.
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147
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Tissue specific induction of p62/Sqstm1 by farnesoid X receptor. PLoS One 2012; 7:e43961. [PMID: 22952826 PMCID: PMC3428273 DOI: 10.1371/journal.pone.0043961] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Accepted: 07/30/2012] [Indexed: 12/22/2022] Open
Abstract
Background Farnesoid X Receptor (FXR) is a member of the nuclear receptor superfamily and is a ligand-activated transcription factor essential for maintaining liver and intestinal homeostasis. FXR is protective against carcinogenesis and inflammation in liver and intestine as demonstrated by the development of inflammation and tumors in the liver and intestine of FXR knock-out mice. However, mechanisms for the protective effects of FXR are not completely understood. This study reports a novel role of FXR in regulating expression of Sqstm1, which encodes for p62 protein. p62 plays an important role in maintaining cellular homeostasis through selective autophagy and activating signal transduction pathways, such as NF-κB to support cell survival and caspase-8 to initiate apoptosis. FXR regulation of Sqstm1 may serve as a protective mechanism. Methods and Results This study showed that FXR bound to the Sqstm1 gene in both mouse livers and ileums as determined by chromatin immunoprecipitation. In addition, FXR activation enhanced transcriptional activation of Sqstm1 in vitro. However, wild-type mice treated with GW4064, a synthetic FXR ligand, showed that FXR activation induced mRNA and protein expression of Sqstm1/p62 in ileum, but not in liver. Interestingly, FXR-transgenic mice showed induced mRNA expression of Sqstm1 in both liver and ileum compared to wild-type mice. Conclusions Our current study has identified a novel role of FXR in regulating the expression of p62, a key factor in protein degradation and cell signaling. Regulation of p62 by FXR indicates tissue-specific and gene-dosage effects. Furthermore, FXR-mediated induction of p62 may implicate a protective mechanism of FXR.
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148
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Hollman DAA, Milona A, van Erpecum KJ, van Mil SWC. Anti-inflammatory and metabolic actions of FXR: insights into molecular mechanisms. Biochim Biophys Acta Mol Cell Biol Lipids 2012; 1821:1443-52. [PMID: 22820415 DOI: 10.1016/j.bbalip.2012.07.004] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Revised: 06/29/2012] [Accepted: 07/05/2012] [Indexed: 01/03/2023]
Abstract
The farnesoid X receptor (FXR) is a ligand-activated transcription factor belonging to the nuclear receptor (NR) superfamily. FXR plays an important role in positively regulating genes (transactivation) involved in bile acid homeostasis, fat and glucose metabolism. Recently, it has become clear that an additional important role for FXR consists of downregulating genes involved in inflammation. Because of this broad spectrum of regulated genes, therapeutically targeting FXR with full agonists will likely result in adverse side effects, in line with what is described for other NRs. It may therefore be necessary to develop selective FXR modulators. However, the molecular mechanisms that distinguish between FXR-mediated transactivation and transrepression are currently unknown. For other NRs, post-translational modifications such as SUMOylation and phosphorylation have been reported to be unique to either transactivation or transrepression. Here, we review current knowledge on post-translational regulation of FXR with respect to transactivation and transrepression. Ultimately, increased understanding of the different mechanisms of transactivation and transrepression of nuclear receptors will aid in the development of NR drugs with fewer side effects.
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Affiliation(s)
- Danielle A A Hollman
- Department of Metabolic Diseases, UMC Utrecht and Netherlands Metabolomics Centre, The Netherlands
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Baptissart M, Vega A, Maqdasy S, Caira F, Baron S, Lobaccaro JMA, Volle DH. Bile acids: from digestion to cancers. Biochimie 2012; 95:504-17. [PMID: 22766017 DOI: 10.1016/j.biochi.2012.06.022] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Accepted: 06/21/2012] [Indexed: 02/07/2023]
Abstract
Bile acids (BAs) are cholesterol metabolites that have been extensively studied these last decades. BAs have been classified in two groups. Primary BAs are synthesized in liver, when secondary BAs are produced by intestinal bacteria. Recently, next to their ancestral roles in digestion and fat solubilization, BAs have been described as signaling molecules involved in many physiological functions, such as glucose and energy metabolisms. These signaling pathways involve the activation of the nuclear receptor FXRα or of the G-protein-coupled receptor TGR5. These two receptors have selective affinity to different types of BAs and show different expression patterns, leading to different described roles of BAs. It has been suggested for long that BAs could be molecules linked to tumor processes. Indeed, as many other molecules, regarding analyzed tissues, BAs could have either protective or pro-carcinogen activities. However, the molecular mechanisms responsible for these effects have not been characterized yet. It involves either chemical properties or their capacities to activate their specific receptors FXRα or TGR5. This review highlights and discusses the potential links between BAs and cancer diseases and the perspectives of using BAs as potential therapeutic targets in several pathologies.
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Affiliation(s)
- Marine Baptissart
- INSERM U 1103, Génétique Reproduction et Développement, Aubiere, France
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Ohno T, Shirakami Y, Shimizu M, Kubota M, Sakai H, Yasuda Y, Kochi T, Tsurumi H, Moriwaki H. Synergistic growth inhibition of human hepatocellular carcinoma cells by acyclic retinoid and GW4064, a farnesoid X receptor ligand. Cancer Lett 2012; 323:215-22. [PMID: 22579649 DOI: 10.1016/j.canlet.2012.04.015] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Revised: 03/29/2012] [Accepted: 04/20/2012] [Indexed: 01/03/2023]
Abstract
Abnormalities in the expression and function of retinoid X receptor (RXR), a master regulator of the nuclear receptor superfamily, are associated with the development of hepatocellular carcinoma (HCC). Dysfunction of farnesoid X receptor (FXR), one of the nuclear receptors that forms a heterodimer with RXR, also plays a role in liver carcinogenesis. In the present study, we examined the effects of acyclic retinoid (ACR), a synthetic retinoid targeting RXRα, plus GW4064, a ligand for FXR, on the growth of human HCC cells. We found that ACR and GW4064 preferentially inhibited the growth of HLE, HLF, and Huh7 human HCC cells in comparison with Hc normal hepatocytes. The combination of 1μM ACR plus 1μM GW4064 synergistically inhibited the growth of HLE cells by inducing apoptosis. The combined treatment with these agents acted cooperatively to induce cell cycle arrest in the G(0)/G(1) phase and inhibit the phosphorylation of RXRα, which is regarded as a critical factor for liver carcinogenesis, through inhibition of ERK and Stat3 phosphorylation. This combination also increased the expression levels of p21(CIP1) and SHP mRNA, while decreasing the levels of c-myc and cyclin D1 mRNA in HLE cells. In addition, a reporter assay indicated that the FXRE promoter activity was significantly increased by treatment with ACR plus GW4064. Our results suggest that ACR and GW4064 cooperatively inhibit RXRα phosphorylation, modulate the expression of FXR-regulated genes, thus resulting in the induction of apoptosis and the inhibition of growth in HCC cells. This combination might therefore be effective for the chemoprevention and chemotherapy of HCC.
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