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Rodrigues C, Ismael S, Castela I, Barreiros-Mota I, Almeida MJ, Santos GM, Calhau C, Rocha JC, Faria A, Araújo JR. Trimethylamine increases intestinal fatty acid absorption: in vitro studies in a Caco-2 cell culture system. J Nutr Sci 2023; 12:e108. [PMID: 37964979 PMCID: PMC10641700 DOI: 10.1017/jns.2023.91] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 09/11/2023] [Accepted: 10/06/2023] [Indexed: 11/16/2023] Open
Abstract
Although elevated blood levels of trimethylamine N-oxide (TMAO) have been associated with atherosclerosis development in humans, the role of its gut microbiota-derived precursor, TMA, in this process has not been yet deciphered. Taking this into account, and the fact that increased intestinal fatty acid absorption contributes to atherosclerosis onset and progression, this study aimed to evaluate the effect of TMA on fatty acid absorption in a cell line that mimics human enterocytes. Caco-2 cells were treated with TMA 250 μM for 24 h. Fatty acid absorption was assessed by measuring the apical-to-basolateral transport and the intracellular levels of BODIPY-C12, a fluorescently labelled fatty acid analogue. Gene expression of the main intestinal fatty acid transporters was evaluated by real-time quantitative reverse transcription PCR. Compared to control conditions, TMA increased, in a time-dependent manner and by 20-50 %, the apical-to-basolateral transport and intracellular levels of BODIPY-C12 fatty acid in Caco-2 cells. Fatty acid transport protein 4 (FATP4) and fatty acid translocase (FAT)/CD36 gene expression were not stimulated by TMA, suggesting that TMA-induced increase in fatty acid transport may be mediated by an increase in FAT/CD36 and/or FATP4 activity and/or fatty acid passive transport. This study demonstrated that TMA increases the intestinal absorption of fatty acids. Future studies are necessary to confirm if this may constitute a novel mechanism that partially explains the existing positive association between the consumption of a diet rich in TMA sources (e.g. red meat) and the increased risk of atherosclerotic diseases.
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Key Words
- Caco-2 cells
- EDTA, ethylenediaminetetraacetic acid
- Enterocytes
- F, forward
- FABP, fatty acid-binding protein
- FABPpm, plasma membrane fatty acid-binding protein
- FAT/CD36, fatty acid translocase
- FATP4, fatty acid transport protein 4
- FBS, foetal bovine serum
- FSA, fluorescein sulphonic acid
- Fatty acid absorption
- HPRT, hypoxanthine guanine phosphoribosyltransferase
- MTT, 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide
- PBS, phosphate-buffered saline
- R, reverse
- TG, triacylglycerol
- TMA, trimethylamine
- TMAO, trimethylamine N-oxide
- Trimethylamine
- qRT-PCR, real-time quantitative reverse transcription polymerase chain reaction
- sem, standard error of the mean
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Affiliation(s)
- Catarina Rodrigues
- Nutrition & Metabolism, CHRC, NOVA Medical School, Faculdade de Ciências Médicas, NMS, FCM, Universidade NOVA de Lisboa, Lisboa, Portugal
| | - Shámila Ismael
- Nutrition & Metabolism, CHRC, NOVA Medical School, Faculdade de Ciências Médicas, NMS, FCM, Universidade NOVA de Lisboa, Lisboa, Portugal
- Nutrition & Metabolism, CINTESIS@RISE, NOVA Medical School, Faculdade de Ciências Médicas, NMS, FCM, Universidade NOVA de Lisboa, Lisboa, Portugal
| | - Inês Castela
- Nutrition & Metabolism, CHRC, NOVA Medical School, Faculdade de Ciências Médicas, NMS, FCM, Universidade NOVA de Lisboa, Lisboa, Portugal
- Nutrition & Metabolism, CINTESIS@RISE, NOVA Medical School, Faculdade de Ciências Médicas, NMS, FCM, Universidade NOVA de Lisboa, Lisboa, Portugal
| | - Inês Barreiros-Mota
- Nutrition & Metabolism, CHRC, NOVA Medical School, Faculdade de Ciências Médicas, NMS, FCM, Universidade NOVA de Lisboa, Lisboa, Portugal
| | - Maria João Almeida
- Nutrition & Metabolism, CHRC, NOVA Medical School, Faculdade de Ciências Médicas, NMS, FCM, Universidade NOVA de Lisboa, Lisboa, Portugal
| | - Gilberto Maia Santos
- Nutrition & Metabolism, CHRC, NOVA Medical School, Faculdade de Ciências Médicas, NMS, FCM, Universidade NOVA de Lisboa, Lisboa, Portugal
| | - Conceição Calhau
- Nutrition & Metabolism, CINTESIS@RISE, NOVA Medical School, Faculdade de Ciências Médicas, NMS, FCM, Universidade NOVA de Lisboa, Lisboa, Portugal
- Unidade Universitária Lifestyle Medicine José de Mello Saúde by NOVA Medical School, Faculdade de Ciências Médicas, NMS, FCM, Universidade NOVA de Lisboa, Lisboa, Portugal
| | - Júlio César Rocha
- Nutrition & Metabolism, CINTESIS@RISE, NOVA Medical School, Faculdade de Ciências Médicas, NMS, FCM, Universidade NOVA de Lisboa, Lisboa, Portugal
- Reference Centre of Inherited Metabolic Diseases, Centro Hospitalar Universitário de Lisboa Central, Lisboa, Portugal
| | - Ana Faria
- Nutrition & Metabolism, CHRC, NOVA Medical School, Faculdade de Ciências Médicas, NMS, FCM, Universidade NOVA de Lisboa, Lisboa, Portugal
- Nutrition & Metabolism, CINTESIS@RISE, NOVA Medical School, Faculdade de Ciências Médicas, NMS, FCM, Universidade NOVA de Lisboa, Lisboa, Portugal
| | - João R. Araújo
- Nutrition & Metabolism, CINTESIS@RISE, NOVA Medical School, Faculdade de Ciências Médicas, NMS, FCM, Universidade NOVA de Lisboa, Lisboa, Portugal
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Organoid-derived intestinal epithelial cells are a suitable model for preclinical toxicology and pharmacokinetic studies. iScience 2022; 25:104542. [PMID: 35754737 PMCID: PMC9218437 DOI: 10.1016/j.isci.2022.104542] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 01/06/2022] [Accepted: 06/02/2022] [Indexed: 12/28/2022] Open
Abstract
Intestinal organoids are physiologically relevant tools used for cellular models. However, the suitability of organoids to examine biological functions over existing established cell lines lacks sufficient evidence. Cytochrome P450 3A4 (CYP3A4) induction by pregnane X receptor ligands, glucose uptake via sodium/glucose cotransporter 1, and microsomal triglyceride transfer protein-dependent ApoB-48 secretion, which are critical for human intestinal metabolism, were observed in organoid-derived two-dimensional cells but little in Caco-2 cells. CYP3A4 induction evaluation involved a simplified method of establishing organoids that constitutively expressed a reporter gene. Compound screening identified several anticancer drugs with selective activities toward Caco-2 cells, highlighting their characteristics as cancer cells. Another compound screening revealed a decline in N-(4-hydroxyphenyl)retinamide cytotoxicity upon rifampicin treatment in organoid-derived cells, under CYP3A4-induced conditions. This study shows that organoid-derived intestinal epithelial cells (IECs) possess similar physiological properties as intestinal epithelium and can serve as tools for enhancing the prediction of biological activity in humans. Comparison of mRNA expression between organoid-derived intestinal epithelial cells (IECs) and Caco-2 cells Evaluation of CYP3A4, SGLT1, and MTP protein function in organoid-derived IECs Identification of anti-cancer drugs as selective cytotoxicity against Caco-2 cells Reduction of N-(4-hydroxyphenyl)retinamide (4-HPR) cytotoxicity by rifampicin in organoid-derived IECs
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Gene Expression Changes Accompanying the Duodenal Adenoma-Carcinoma Sequence in Familial Adenomatous Polyposis. Clin Transl Gastroenterol 2020; 10:e00053. [PMID: 31211760 PMCID: PMC6613862 DOI: 10.14309/ctg.0000000000000053] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Duodenal cancer in familial adenomatous polyposis (FAP) arises from adenomas. Differentially expressed genes (DEGs) in the duodenal adenoma-carcinoma pathway have been identified in murine FAP models, but similar data in patients with FAP are limited. Identifying such changes may have significance in understanding duodenal polyposis therapies and identifying cancer biomarkers. We performed a genome-wide transcriptional analysis to describe the duodenal adenoma-carcinoma sequence and determine changes distinguishing patients with FAP with and without duodenal cancer.
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Hung CS, Wang YC, Guo JW, Yang RN, Lee CL, Shen MH, Huang CC, Huang CJ, Yang JY, Liu CY. Expression pattern of placenta specific 8 and keratin 20 in different types of gastrointestinal cancer. Mol Med Rep 2019; 21:659-666. [PMID: 31974611 PMCID: PMC6947936 DOI: 10.3892/mmr.2019.10871] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 11/06/2019] [Indexed: 12/14/2022] Open
Abstract
The aim of the present study was to investigate the expression of keratin 20 (KRT20) and placenta specific 8 (PLAC8) in gastrointestinal (GI) cancer with various differentiation phenotypes. The present study retrospectively investigated archived formalin-fixed paraffin-embedded tissue samples from 12 patients at different stages of GI cancer [four with gastric cancer, four with pancreatic cancer and four with colorectal cancer (CRC)]. The stages were pre-determined, according to differentiation phenotypes, by a pathologist of the Department of Pathology at Sijhih Cathay General Hospital. KRT20 and PLAC8 expression levels were assessed using immunohistochemistry. The CRC cell lines SW620 and Caco-2 were used to assess interactions between KRT20 and PLAC8 via reverse transcription-quantitative PCR. PLAC8 and KRT20 expression was observed consistently only in the well-differentiated CRC tissue samples. Low KRT20 expression levels were observed in the PLAC8 knockdown SW620 cells. In addition, there was a positive association between PLAC8 and KRT20 expression in the differentiated Caco-2 cells. According to the results of the present study, the differentiation status of GI cancer influenced KRT20 expression, particularly in CRC, which may explain why patients with well-differentiated CRC display better clinical outcomes. Therefore, the prognostic significance of KRT20 and PLAC8 may be particularly crucial for patients with CRC displaying a well-differentiated phenotype.
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Affiliation(s)
- Chih-Sheng Hung
- Department of Internal Medicine, Division of Gastroenterology, Cathay General Hospital, Taipei 10630, Taiwan, R.O.C
| | - Yen-Chieh Wang
- Department of Surgery, Division of Urology, Cathay General Hospital, Taipei 10630, Taiwan, R.O.C
| | - Jiun-Wen Guo
- Department of Medical Research, Cathay General Hospital, Taipei 10630, Taiwan, R.O.C
| | - Ruey-Neng Yang
- Department of Internal Medicine, Sijhih Cathay General Hospital, New Taipei 22174, Taiwan, R.O.C
| | - Chia-Long Lee
- Department of Internal Medicine, Division of Gastroenterology, Cathay General Hospital, Taipei 10630, Taiwan, R.O.C
| | - Ming-Hung Shen
- School of Medicine, College of Medicine, Fu Jen Catholic University, New Taipei 24205, Taiwan, R.O.C
| | - Chi-Cheng Huang
- Department of Surgery, Taipei‑Veterans General Hospital, Taipei 11217, Taiwan, R.O.C
| | - Chi-Jung Huang
- School of Medicine, College of Medicine, Fu Jen Catholic University, New Taipei 24205, Taiwan, R.O.C
| | - Jhih-Yun Yang
- Department of Mathematics, Taipei Wego Private Senior High School, Taipei 11254, Taiwan, R.O.C
| | - Chih-Yi Liu
- Department of Pathology, Sijhih Cathay General Hospital, New Taipei 22174, Taiwan, R.O.C
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Mogilenko DA, Shavva VS, Dizhe EB, Orlov SV. Characterization of Distal and Proximal Alternative Promoters of the Human ApoA-I Gene. Mol Biol 2019. [DOI: 10.1134/s0026893319030129] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Identification of serum proteome signature of irritable bowel syndrome: Potential utility of the tool for early diagnosis and patient's stratification. J Proteomics 2018; 188:167-172. [PMID: 28757466 DOI: 10.1016/j.jprot.2017.07.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 07/24/2017] [Accepted: 07/25/2017] [Indexed: 02/08/2023]
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Sané AT, Seidman E, Peretti N, Kleme ML, Delvin E, Deslandres C, Garofalo C, Spahis S, Levy E. Understanding Chylomicron Retention Disease Through Sar1b Gtpase Gene Disruption: Insight From Cell Culture. Arterioscler Thromb Vasc Biol 2017; 37:2243-2251. [PMID: 28982670 DOI: 10.1161/atvbaha.117.310121] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 09/21/2017] [Indexed: 01/28/2023]
Abstract
BACKGROUND Understanding the specific mechanisms of rare autosomal disorders has greatly expanded insights into the complex processes regulating intestinal fat transport. Sar1B GTPase is one of the critical proteins governing chylomicron secretion by the small intestine, and its mutations lead to chylomicron retention disease, despite the presence of Sar1A paralog. OBJECTIVE The central aim of this work is to examine the cause-effect relationship between Sar1B expression and chylomicron output and to determine whether Sar1B is obligatory for normal high-density lipoprotein biogenesis. APPROACH AND RESULTS The SAR1B gene was totally silenced in Caco-2/15 cells using the zinc finger nuclease technique. SAR1B deletion resulted in significantly decreased secretion of triglycerides (≈40%), apolipoprotein B-48 (≈57%), and chylomicron (≈34.5%). The absence of expected chylomicron production collapse may be because of the compensatory SAR1A elevation observed in our experiments. Therefore, a double knockout of SAR1A and SAR1B was engineered in Caco-2/15 cells, which led to almost complete inhibition of triglycerides, apolipoprotein B-48, and chylomicron output. Further experiments with labeled cholesterol revealed the downregulation of high-density lipoprotein biogenesis in cells deficient in SAR1B or with the double knockout of the 2 SAR1 paralogs. Similarly, there was a fall in the movement of labeled cholesterol from cells to basolateral medium containing apolipoprotein A-I, thereby limiting newly synthesized high-density lipoprotein in genetically modified cells. The decreased cholesterol efflux was associated with impaired expression of ABCA1 (ATP-binding cassette subfamily A member 1). CONCLUSIONS These findings demonstrate that the deletion of the 2 SAR1 isoforms is required to fully eliminate the secretion of chylomicron in vitro. They also underscore the limited high-density lipoprotein production by the intestinal cells in response to SAR1 knockout.
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Affiliation(s)
- Alain Théophile Sané
- From the CHU Sainte-Justine Research Centre (A.T.S., M.L.K., E.D., C.D., C.G., S.S., E.L.), Department of Nutrition (M.L.K., S.S., E.L.), and Department of Pediatrics (C.D.), Université de Montréal, Quebec, Canada; Division of Gastroenterology, Research Institute of the McGill University Health Center, Montreal, Quebec, Canada (E.S.); and Centre de recherche Rhône-Alpes en nutrition humaine, Hôpital Edouard-Herriot, Université de Lyon 1, France (N.P.)
| | - Ernest Seidman
- From the CHU Sainte-Justine Research Centre (A.T.S., M.L.K., E.D., C.D., C.G., S.S., E.L.), Department of Nutrition (M.L.K., S.S., E.L.), and Department of Pediatrics (C.D.), Université de Montréal, Quebec, Canada; Division of Gastroenterology, Research Institute of the McGill University Health Center, Montreal, Quebec, Canada (E.S.); and Centre de recherche Rhône-Alpes en nutrition humaine, Hôpital Edouard-Herriot, Université de Lyon 1, France (N.P.)
| | - Noel Peretti
- From the CHU Sainte-Justine Research Centre (A.T.S., M.L.K., E.D., C.D., C.G., S.S., E.L.), Department of Nutrition (M.L.K., S.S., E.L.), and Department of Pediatrics (C.D.), Université de Montréal, Quebec, Canada; Division of Gastroenterology, Research Institute of the McGill University Health Center, Montreal, Quebec, Canada (E.S.); and Centre de recherche Rhône-Alpes en nutrition humaine, Hôpital Edouard-Herriot, Université de Lyon 1, France (N.P.)
| | - Marie Laure Kleme
- From the CHU Sainte-Justine Research Centre (A.T.S., M.L.K., E.D., C.D., C.G., S.S., E.L.), Department of Nutrition (M.L.K., S.S., E.L.), and Department of Pediatrics (C.D.), Université de Montréal, Quebec, Canada; Division of Gastroenterology, Research Institute of the McGill University Health Center, Montreal, Quebec, Canada (E.S.); and Centre de recherche Rhône-Alpes en nutrition humaine, Hôpital Edouard-Herriot, Université de Lyon 1, France (N.P.)
| | - Edgard Delvin
- From the CHU Sainte-Justine Research Centre (A.T.S., M.L.K., E.D., C.D., C.G., S.S., E.L.), Department of Nutrition (M.L.K., S.S., E.L.), and Department of Pediatrics (C.D.), Université de Montréal, Quebec, Canada; Division of Gastroenterology, Research Institute of the McGill University Health Center, Montreal, Quebec, Canada (E.S.); and Centre de recherche Rhône-Alpes en nutrition humaine, Hôpital Edouard-Herriot, Université de Lyon 1, France (N.P.)
| | - Colette Deslandres
- From the CHU Sainte-Justine Research Centre (A.T.S., M.L.K., E.D., C.D., C.G., S.S., E.L.), Department of Nutrition (M.L.K., S.S., E.L.), and Department of Pediatrics (C.D.), Université de Montréal, Quebec, Canada; Division of Gastroenterology, Research Institute of the McGill University Health Center, Montreal, Quebec, Canada (E.S.); and Centre de recherche Rhône-Alpes en nutrition humaine, Hôpital Edouard-Herriot, Université de Lyon 1, France (N.P.)
| | - Carole Garofalo
- From the CHU Sainte-Justine Research Centre (A.T.S., M.L.K., E.D., C.D., C.G., S.S., E.L.), Department of Nutrition (M.L.K., S.S., E.L.), and Department of Pediatrics (C.D.), Université de Montréal, Quebec, Canada; Division of Gastroenterology, Research Institute of the McGill University Health Center, Montreal, Quebec, Canada (E.S.); and Centre de recherche Rhône-Alpes en nutrition humaine, Hôpital Edouard-Herriot, Université de Lyon 1, France (N.P.)
| | - Schohraya Spahis
- From the CHU Sainte-Justine Research Centre (A.T.S., M.L.K., E.D., C.D., C.G., S.S., E.L.), Department of Nutrition (M.L.K., S.S., E.L.), and Department of Pediatrics (C.D.), Université de Montréal, Quebec, Canada; Division of Gastroenterology, Research Institute of the McGill University Health Center, Montreal, Quebec, Canada (E.S.); and Centre de recherche Rhône-Alpes en nutrition humaine, Hôpital Edouard-Herriot, Université de Lyon 1, France (N.P.)
| | - Emile Levy
- From the CHU Sainte-Justine Research Centre (A.T.S., M.L.K., E.D., C.D., C.G., S.S., E.L.), Department of Nutrition (M.L.K., S.S., E.L.), and Department of Pediatrics (C.D.), Université de Montréal, Quebec, Canada; Division of Gastroenterology, Research Institute of the McGill University Health Center, Montreal, Quebec, Canada (E.S.); and Centre de recherche Rhône-Alpes en nutrition humaine, Hôpital Edouard-Herriot, Université de Lyon 1, France (N.P.).
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Kitahara T, Haraguchi N, Takahashi H, Nishimura J, Hata T, Takemasa I, Mizushima T, Yamamoto H, Doki Y, Mori M. Identification and Characterization of CD107a as a Marker of Low Reactive Oxygen Species in Chemoresistant Cells in Colorectal Cancer. Ann Surg Oncol 2016; 24:1110-1119. [PMID: 27834032 DOI: 10.1245/s10434-016-5671-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Indexed: 11/18/2022]
Abstract
BACKGROUND Reactive oxygen species (ROS) generated by chemoradiotherapy lead to cancer cell death. Although ROS regulation mechanisms play important roles in chemoradioresistance, few markers exist that indicated intracellular ROS status. This study aimed to identify novel cell surface markers that represented intracellular ROS status to characterize cells with low ROS (ROSlow) in colorectal cancer (CRC). METHODS We used ROS indicators and an antibody array with 242 cell surface antibodies to identify markers of ROSlow cells. After validation, we performed immunohistochemical analyses and chemosensitivity assays. We used small interfering RNA to assess the effect of silencing the identified markers. We tested cell differentiation assays with spheroid cell assays. RESULTS CD107a was identified as a common marker of ROSlow cells in several CRC cell lines and clinical specimens. CD107a+/ROSlow cells were enriched in HT29 and DLD1 cultures after treatments with oxaliplatin, 5-fluorouracil, and the irinotecan metabolite SN38. CD107a silencing improved chemosensitivity by increasing ROS production. Immunohistochemistry showed enhanced CD107a surface expression on cells that formed immature cell clusters and on cells located in the invasive fronts of cancer foci. CD107a expression was also enhanced on specimens from patients with poorly differentiated adenocarcinoma who had received neoadjuvant chemotherapy. Cell surface CD107a expression was enhanced on cells that formed colonospheres, but expression diminished during cell differentiation. CONCLUSIONS CD107a was identified as a novel marker of ROSlow cells in CRC. CD107a expression was closely related to chemoresistance and the immature cell phenotype. Anti-CD107a treatments represent a novel approach for targeting chemoresistant cells in CRC.
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Affiliation(s)
- Tomohiro Kitahara
- Department of Gastroenterological Surgery, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Naotsugu Haraguchi
- Department of Gastroenterological Surgery, Graduate School of Medicine, Osaka University, Osaka, Japan.
| | - Hidekazu Takahashi
- Department of Gastroenterological Surgery, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Junichi Nishimura
- Department of Gastroenterological Surgery, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Taishi Hata
- Department of Gastroenterological Surgery, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Ichiro Takemasa
- Department of Gastroenterological Surgery, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Tsunekazu Mizushima
- Department of Gastroenterological Surgery, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Hirofumi Yamamoto
- Department of Gastroenterological Surgery, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Yuichiro Doki
- Department of Gastroenterological Surgery, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Masaki Mori
- Department of Gastroenterological Surgery, Graduate School of Medicine, Osaka University, Osaka, Japan
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Farkas AE, Hilgarth RS, Capaldo CT, Gerner-Smidt C, Powell DR, Vertino PM, Koval M, Parkos CA, Nusrat A. HNF4α regulates claudin-7 protein expression during intestinal epithelial differentiation. THE AMERICAN JOURNAL OF PATHOLOGY 2016. [PMID: 26216285 DOI: 10.1016/j.ajpath.2015.04.023] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The intestinal epithelium is a dynamic barrier that maintains the distinct environments of intestinal tissue and lumen. Epithelial barrier function is defined principally by tight junctions, which, in turn, depend on the regulated expression of claudin family proteins. Claudins are expressed differentially during intestinal epithelial cell (IEC) differentiation. However, regulatory mechanisms governing claudin expression during epithelial differentiation are incompletely understood. We investigated the molecular mechanisms regulating claudin-7 during IEC differentiation. Claudin-7 expression is increased as epithelial cells differentiate along the intestinal crypt-luminal axis. By using model IECs we observed increased claudin-7 mRNA and nascent heteronuclear RNA levels during differentiation. A screen for potential regulators of the CLDN7 gene during IEC differentiation was performed using a transcription factor/DNA binding array, CLDN7 luciferase reporters, and in silico promoter analysis. We identified hepatocyte nuclear factor 4α as a regulatory factor that bound endogenous CLDN7 promoter in differentiating IECs and stimulated CLDN7 promoter activity. These findings support a role of hepatocyte nuclear factor 4α in controlling claudin-7 expression during IEC differentiation.
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Affiliation(s)
- Attila E Farkas
- Epithelial Pathobiology and Mucosal Inflammation Research Unit, Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia
| | - Roland S Hilgarth
- Epithelial Pathobiology and Mucosal Inflammation Research Unit, Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia
| | - Christopher T Capaldo
- Epithelial Pathobiology and Mucosal Inflammation Research Unit, Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia
| | - Christian Gerner-Smidt
- Epithelial Pathobiology and Mucosal Inflammation Research Unit, Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia
| | - Doris R Powell
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia
| | - Paula M Vertino
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia
| | - Michael Koval
- Department of Radiation Oncology and the Winship Cancer Institute, Emory University School of Medicine, Atlanta, Georgia
| | - Charles A Parkos
- Epithelial Pathobiology and Mucosal Inflammation Research Unit, Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia; Department of Pathology, University of Michigan, Ann Arbor, Michigan
| | - Asma Nusrat
- Epithelial Pathobiology and Mucosal Inflammation Research Unit, Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia; Department of Pathology, University of Michigan, Ann Arbor, Michigan.
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Fiordaliso F, Maggioni S, Balconi G, Schiarea S, Corbelli A, De Luigi A, Figliuzzi M, Antoniou X, Chiabrando C, Masson S, Cervo L, Latini R. Effects of dipeptidyl peptidase-4 (DPP-4) inhibition on angiogenesis and hypoxic injury in type 2 diabetes. Life Sci 2016; 154:87-95. [PMID: 27040669 DOI: 10.1016/j.lfs.2016.03.052] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Revised: 03/17/2016] [Accepted: 03/28/2016] [Indexed: 12/31/2022]
Abstract
AIMS We examined whether, in diabetic Ob/Ob mice, the dipeptidyl peptidase-4 (DPP-4) inhibitor (PKF275-055), an antihyperglycemic drug, that inhibits the biological inactivation of SDF-1 (stromal cell-derived factor-1), may increase endothelial progenitor cells (EPCs) mobilization and incorporation, which, in turn, may regenerate capillaries and reduce myocardial ischemia induced by strenuous exercise. MAIN METHODS Half of sixteen control and Ob/Ob mice and eight Ob/Ob mice treated with PKF275-055 for four weeks underwent a forced swim protocol. Oral glucose tolerance, circulating EPCs, capillary ultrastructure and density, hypoxic areas and SDF-1 localization in myocardium were measured. KEY FINDINGS Ob/Ob mice were glucose intolerant, had a significant low number of circulating EPCs and myocardial capillaries compared to lean controls. The DPP-4 inhibitor significantly improved their glucose tolerance, doubled the number of circulating EPCs, stimulated the formation of functional vessels and SDF-1 localization in the endothelium of myocardial capillaries and arterioles. Cardiac hypoxia after forced swim in Ob/Ob mice was significantly reduced when they were treated with the DPP-4 inhibitor. SIGNIFICANCE DPP-4 inhibition may re-establish an adequate capillary network in the myocardium of diabetic Ob/Ob mice by the mobilization and SDF-1-mediated incorporation of EPCs and, consequently, reducing the susceptibility to myocardial ischemic injury provoked by strenuous exercise.
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Affiliation(s)
- Fabio Fiordaliso
- Department of Cardiovascular Research, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", 20156 Milan, Italy.
| | - Serena Maggioni
- Department of Cardiovascular Research, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", 20156 Milan, Italy
| | - Giovanna Balconi
- Department of Cardiovascular Research, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", 20156 Milan, Italy
| | - Silvia Schiarea
- Department of Environmental Health Sciences, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", 20156 Milan, Italy
| | - Alessandro Corbelli
- Department of Cardiovascular Research, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", 20156 Milan, Italy
| | - Ada De Luigi
- Department of Molecular Biochemistry and Pharmacology, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", 20156 Milan, Italy
| | - Marina Figliuzzi
- Department of Biomedical Engineering, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", 24126 Bergamo, Italy
| | - Xenia Antoniou
- Department of Neuroscience, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", 20156 Milan, Italy
| | - Chiara Chiabrando
- Department of Environmental Health Sciences, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", 20156 Milan, Italy
| | - Serge Masson
- Department of Cardiovascular Research, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", 20156 Milan, Italy
| | - Luigi Cervo
- Department of Neuroscience, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", 20156 Milan, Italy
| | - Roberto Latini
- Department of Cardiovascular Research, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", 20156 Milan, Italy
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11
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Turano M, Angrisani A, Di Maio N, Furia M. Intron retention: a human DKC1 gene common splicing event. Biochem Cell Biol 2013; 91:506-12. [DOI: 10.1139/bcb-2013-0047] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Identification of alternatively spliced transcripts produced by a gene is a crucial step in deciphering the bulk of its biological roles and the overall processes that regulate its activity. By using a combination of bioinformatic and molecular approaches we identified, cloned, and characterized 3 novel alternative splice isoforms derived from human dyskeratosis congenita 1 (hDKC1), an essential human gene causative of the X-linked dyskeratosis congenita disease and involved in multiple functions related to cell growth, proliferation, and telomere maintenance. Expression of the new isoforms, all characterized by intron retention, was confirmed by RT-PCR in a panel of diverse cell lines and normal human tissues, and despite the presence of premature termination codons, was not down-regulated by the mechanism of nonsense-mediated decay. Accumulation of these transcripts fluctuated distinctly in the diverse tissues and during in vitro differentiation of Caco2 cells, suggesting that their ratio may contribute to the gene functional diversity across different cell types. Intriguingly, the structure of one isoform leads to exonize an intronically encoded small nucleolar RNA (snoRNA), highlighting an additional layer of complexity that can contribute to overall gene regulation.
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Affiliation(s)
- Mimmo Turano
- Dipartimento di Biologia, Complesso Universitario di Monte S. Angelo, Università di Napoli “Federico II”, via Cinthia, 80126 Napoli, Italia
| | - Alberto Angrisani
- Dipartimento di Biologia, Complesso Universitario di Monte S. Angelo, Università di Napoli “Federico II”, via Cinthia, 80126 Napoli, Italia
| | - Nunzia Di Maio
- Dipartimento di Biologia, Complesso Universitario di Monte S. Angelo, Università di Napoli “Federico II”, via Cinthia, 80126 Napoli, Italia
| | - Maria Furia
- Dipartimento di Biologia, Complesso Universitario di Monte S. Angelo, Università di Napoli “Federico II”, via Cinthia, 80126 Napoli, Italia
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12
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Disterer P, Al-Shawi R, Ellmerich S, Waddington SN, Owen JS, Simons JP, Khoo B. Exon skipping of hepatic APOB pre-mRNA with splice-switching oligonucleotides reduces LDL cholesterol in vivo. Mol Ther 2013; 21:602-9. [PMID: 23319054 DOI: 10.1038/mt.2012.264] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Familial hypercholesterolemia (FH) is a genetic disorder characterized by extremely high levels of plasma low-density lipoprotein (LDL), due to defective LDL receptor-apolipoprotein B (APOB) binding. Current therapies such as statins or LDL apheresis for homozygous FH are insufficiently efficacious at lowering LDL cholesterol or are expensive. Treatments that target APOB100, the structural protein of LDL particles, are potential therapies for FH. We have developed a series of APOB-directed splice-switching oligonucleotides (SSOs) that cause the expression of APOB87, a truncated isoform of APOB100. APOB87, like similarly truncated isoforms expressed in patients with a different condition, familial hypobetalipoproteinemia, lowers LDL cholesterol by inhibiting very low-density lipoprotein (VLDL) assembly and increasing LDL clearance. We demonstrate that these "APO-skip " SSOs induce high levels of exon skipping and expression of the APOB87 isoform, but do not substantially inhibit APOB48 expression in cell lines. A single injection of an optimized APO-skip SSO into mice transgenic for human APOB resulted in abundant exon skipping that persists for >6 days. Weekly treatments generated a sustained reduction in LDL cholesterol levels of 34-51% in these mice, superior to pravastatin in a head-to-head comparison. These results validate APO-skip SSOs as a candidate therapy for FH.
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Affiliation(s)
- Petra Disterer
- Institute for Liver and Digestive Health, UCL, London, UK
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13
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Ratcliffe DR, Iqbal J, Hussain MM, Cramer EB. Fibrillar collagen type I stimulation of apolipoprotein B secretion in Caco-2 cells is mediated by beta1 integrin. Biochim Biophys Acta Mol Cell Biol Lipids 2009; 1791:1144-54. [PMID: 19646550 DOI: 10.1016/j.bbalip.2009.07.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2009] [Revised: 06/29/2009] [Accepted: 07/21/2009] [Indexed: 11/19/2022]
Abstract
Caco-2 cells spontaneously differentiate into enterocyte-like cells and secrete apolipoprotein B (apoB) lipoproteins. We evaluated the effect of different extracellular matrix proteins on lipoprotein secretion by these cells. Caco-2 cells grown on human amnion connective tissue (HACT) secreted twice as much apoB as control cells on Transwells, but secreted similar amounts of apoA1. Cells cultured on fibrillar collagen type I secreted increased amounts of apoB similar to the cells cultured on HACT, but cells cultured on non-fibrillar collagen type I, type IV collagen or laminin-1 did not. The increased secretion was nullified by a function inhibiting anti-integrin beta1 monoclonal antibody. Therefore, interactions between type I collagen and beta1 integrins augment apoB secretion by Caco-2 cells. Cells on HACT formed a more uniform columnar epithelium with lipid droplets polarized to the basolateral membrane. We also studied the effect of extracellular matrix proteins on transepithelial resistance (TER) of differentiated Caco-2 cells. TER in cells cultured on HACT was similar to that on Transwells, but cells on laminin-1 and collagen IV exhibited higher TER. Thus, various extracellular matrix proteins regulate apoB secretion and TER differently. This new observation that extracellular matrix proteins can enhance apoB secretion in Caco-2 cells could be useful to explore the modulation of lipid transport by these proteins.
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Affiliation(s)
- Don R Ratcliffe
- Department of Anatomy, State University of New York Downstate Medical Center, Brooklyn, NY 11203, USA
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14
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Molecular characterization of lung dysplasia induced by c-Raf-1. PLoS One 2009; 4:e5637. [PMID: 19529782 PMCID: PMC2681412 DOI: 10.1371/journal.pone.0005637] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2009] [Accepted: 04/14/2009] [Indexed: 11/19/2022] Open
Abstract
Background Lung cancer is a multistage process with poor prognosis and high morbidity. Importantly, the genetics of dysplasia, a facultative cancer, at the edge of malignant transformation is unknown. Methodology/Principal Findings We employed laser microdissection to harvest c-Raf1- induced dysplastic as opposed to transgenic but otherwise morphologically unaltered epithelium and compared findings to non-transgenic lung. We then employed microarrays to search genome wide for gene regulatory networks. A total of 120 and 287 genes were significantly regulated, respectively. Dysplasia was exclusive associated with up-regulation of genes coding for cell growth and proliferation, cell-to-cell signalling and interaction, lipid metabolism, development, and cancer. Likewise, when dysplasia was compared with non-transgenic cells up-regulation of cancer associated genes, tight junction proteins, xenobiotic defence and developmental regulators was observed. Further, in a comparison of the data sets of dysplasia vs transgenic and dysplasia vs non-transgenic 114 genes were regulated in common. We additionally confirmed regulation of some genes by immunohistochemistry and therefore demonstrate good concordance between gene regulation and coded protein. Conclusion Our study identified transcriptional networks at successive stages of tumor-development, i.e. from histological unaltered but transgenic lungs to nuclear atypia. Our SP-C/c-raf transgenic mouse model revealed interesting and novel candidate genes and pathways that provide clues on the mechanism forcing respiratory epithelium into dysplasia and subsequently cancer, some of which might also be useful in the molecular imaging and flagging of early stages of disease.
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15
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Khair G, Monson JRT, Greenman J. Epithelial molecular markers in the peripheral blood of patients with colorectal cancer. Dis Colon Rectum 2007; 50:1188-203. [PMID: 17436048 DOI: 10.1007/s10350-006-0875-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Despite the modest improvements in patient survival from colorectal cancer in the last few decades, the overall five-year survival rate remains at 40 to 45 percent. Surgical resection is the mainstay of treatment for colorectal cancer; however, nearly one-half of all patients who undergo a potentially curative resection will relapse because of undetected micrometastasis. The fact that the overall survival rate remains poor strongly suggests that the dissemination of these cells occurs early in the disease process and emphasizes the need for finding feasible diagnostic methods with sufficient sensitivity and specificity. The most commonly used technique for the detection of nucleic acid material of disseminated tumor cells is the polymerase chain reaction. We critically review the literature on DNA and messenger ribonucleic acid molecular markers that have been used for the detection of circulating tumor cells in the peripheral blood of patients with colorectal cancer and other solid tumors as appropriate for comparison. The cytokeratins, particularly cytokeratin 19 and cytokeratin 20, are the most investigated prognostic markers, but even for these questions remain about their clinical value, and hence most recent studies are utilizing a combination of factors. There is an urgent need for standardized isolation and analysis techniques to be adopted thus allowing large-scale, appropriately controlled, multicenter trials to be undertaken on the most promising candidate markers.
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Affiliation(s)
- Ghaith Khair
- Cancer Division, Postgraduate Medical Institute, University of Hull, Kingston-upon-Hull, UK
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16
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Oriá RB, Patrick PD, Blackman JA, Lima AAM, Guerrant RL. Role of apolipoprotein E4 in protecting children against early childhood diarrhea outcomes and implications for later development. Med Hypotheses 2006; 68:1099-107. [PMID: 17098371 PMCID: PMC3993898 DOI: 10.1016/j.mehy.2006.09.036] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2006] [Accepted: 09/14/2006] [Indexed: 11/18/2022]
Abstract
Our group and others have reported a series of studies showing that heavy burdens of diarrheal diseases in the formative first two years of life in children in urban shantytowns have profound consequences of impaired physical and cognitive development lasting into later childhood and schooling. Based on these previous studies showing that apolipoprotein E4 (APOE4) is relatively common in favela children, we review recent data suggesting a protective role for the APOE4 allele in the cognitive and physical development of children with heavy burdens of diarrhea in early childhood. Despite being a marker for cognitive decline with Alzheimer's and cardiovascular diseases later in life, APOE4 appears to be important for cognitive development under the stress of heavy diarrhea. The reviewed findings provide a potential explanation for the survival advantage in evolution of the thrifty APOE4 allele and raise questions about its implications for human development under life-style changes and environmental challenges.
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Affiliation(s)
- Reinaldo B Oriá
- Center for Global Health, School of Medicine, University of Virginia, United States.
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17
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Oriá RB, Vieira CMG, Pinkerton RC, de Castro Costa CM, Lopes MB, Hussaini I, Shi W, Brito GAC, Lima AAM, Guerrant RL. Apolipoprotein E knockout mice have accentuated malnutrition with mucosal disruption and blunted insulin-like growth factor I responses to refeeding. Nutr Res 2006; 26:427-435. [PMID: 25210213 DOI: 10.1016/j.nutres.2006.06.020] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Apolipoprotein E (apoE) is synthesized mainly in the liver and in the brain and is critical for cholesterol metabolism and recovery from brain injury. However, although apoE mRNA increases at birth, during suckling, and after fasting in rat liver, little is known about its role in early postnatal development. Using an established postnatal malnutrition model and apoE knock-out (ko) mice, we examined the role of apoE in intestinal adaptation responses to early postnatal malnutrition. Wild-type and apoE-ko mice were separated from their lactating dams for defined periods each day (4 hours on day 1, 8 hours on day 2, and 12 hours thereafter). We found significant growth deficits, as measured by weight gain or tail length, in the apoE-ko mice submitted to a malnutrition challenge, as compared with malnourished wild type, especially during the second week of postnatal development (P < .05). In addition, apoE-ko animals failed to show growth catch-up after refeeding, compared with wild-type malnourished controls. Furthermore, we found shorter crypts and reduced villus height and area in the apoE-ko malnourished mice, compared with controls, after refeeding. Insulinlike growth factor 1 expression was also blunted in the ileum in apoE-ko mice after refeeding, compared with wild-type controls, which exhibited full insulinlike growth factor 1 expression along the intestinal crypts, villi, and in the muscular layer. Taken together, these findings suggest the importance of apoE in coping with a malnutrition challenge and during the intestinal adaptation after refeeding.
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Affiliation(s)
- Reinaldo B Oriá
- Center for Global Health, Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, VA 22908-1379, USA ; Department of Morphology, Federal University of Ceará, Fortaleza, CE 60430-270, Brazil ; Institute of Biomedicine and Clinical Research Unit-University Hospital, Federal University of Ceará, Fortaleza, CE 60430-270, Brazil
| | - Carlos Meton G Vieira
- Center for Global Health, Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, VA 22908-1379, USA
| | - Relana C Pinkerton
- Center for Global Health, Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, VA 22908-1379, USA
| | - Carlos M de Castro Costa
- Physiology and Pharmacology Department, Federal University of Ceará, Fortaleza, CE 60430-270, Brazil
| | - Maria Beatriz Lopes
- Pathology Department, University of Virginia, Charlottesville, VA 22908-1379, USA
| | - Isa Hussaini
- Pathology Department, University of Virginia, Charlottesville, VA 22908-1379, USA
| | - Weibin Shi
- Radiology Department, University of Virginia, Charlottesville, VA 22908-1379, USA
| | - Gerly A C Brito
- Department of Morphology, Federal University of Ceará, Fortaleza, CE 60430-270, Brazil
| | - Aldo A M Lima
- Center for Global Health, Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, VA 22908-1379, USA ; Institute of Biomedicine and Clinical Research Unit-University Hospital, Federal University of Ceará, Fortaleza, CE 60430-270, Brazil
| | - Richard L Guerrant
- Center for Global Health, Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, VA 22908-1379, USA ; Department of Morphology, Federal University of Ceará, Fortaleza, CE 60430-270, Brazil
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18
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19
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Novel N-substituted-2-cyanopyrrolidines as potent inhibitors of dipeptidyl peptidase IV in the treatment of non-insulin-dependent diabetes mellitus. Expert Opin Ther Pat 2005. [DOI: 10.1517/13543776.10.12.1937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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20
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Ripollés Piquer B, Nazih H, Neunlist M, Huvelin JM, Bard JM. Effect of LPS on basal and induced apo E secretion by 25-OH chol and 9cRA in differentiated CaCo-2. J Cell Biochem 2004; 91:786-95. [PMID: 14991770 DOI: 10.1002/jcb.10786] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The infection and inflammation process is associated with disturbances in lipid and lipoprotein metabolism. The apolipoprotein E (apo E) plays an important role in the lipoprotein metabolism and has been linked to inflammatory disease such as atherosclerosis and Alzheimer disease. An anti-inflammatory effect has also been suggested. The heterodimer nuclear receptor Liver-X-Receptor(alpha)/Retinoid-X-Receptor (LXR(alpha)/RXR) is considered to be a transcription factor for apo E. The aim of this study was to determine whether lipopolysaccharide (LPS) (principal component of the outer membrane Gram-negative bacteria) has an effect on apo E secretion by intestinal mucosa cells, using the Caco-2 cell line. Differentiated Caco-2 cells grown on filter inserts were incubated apically with LPS and/or 25-hydroxycholesterol (25-OH chol) and 9 cis retinoic acid (9cRA), ligands of LXR and RXR, respectively. The apical and basolateral media were separately collected. Apo E was detected by specific antibodies after protein separation by Two-dimensional nondenaturing gradient gel electrophoresis and apo E secreted in the cell culture media was measured by enzyme linked immunosorbent assay (ELISA). Apo E mRNA was analyzed by reverse transcription-polymerase chain reaction (RT-PCR). LXR(alpha) and RXR mass was analyzed by Western Blot. We demonstrate here that CaCo-2 cells secrete apo E, by either apical or basolateral sides, associated with a high-density like lipoprotein, with a stoke's diameter comprised between 7.10 and 8.16 nm. We show that only apical secretion is decreased by LPS in a dose and time dependent manner. This is associated with a decrease in apo E gene expression contrasting with an increase of Il-8, a chemokine factor. Moreover, we demonstrate that only basolateral apo E secretion by CaCo-2 is significantly increased by 25-OH chol and 9cRA while apical secretion remains unchanged. LPS does not decrease the 25-OH chol and 9cRA mediated apo E secretion in basolateral compartment, while apical secretion is diminished under these circumstances. Our results provide evidence for the polarized secretion of apo E by intestinal epithelium. They also demonstrate that apo E secretion by CaCo-2 cell line is decreased by LPS through an LXR(alpha)/RXR independent signaling pathway.
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Affiliation(s)
- B Ripollés Piquer
- Laboratoire de Biochimie Fondamentale et Appliquée, UFR de Pharmacie, Nantes, France
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21
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Takasaki K, Iwase M, Nakajima T, Ueno K, Nomoto Y, Nakanishi S, Higo K. K579, a slow-binding inhibitor of dipeptidyl peptidase IV, is a long-acting hypoglycemic agent. Eur J Pharmacol 2004; 486:335-42. [PMID: 14985056 DOI: 10.1016/j.ejphar.2003.12.029] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2003] [Revised: 12/11/2003] [Accepted: 12/19/2003] [Indexed: 11/23/2022]
Abstract
Dipeptidyl peptidase IV inhibitors are expected to be categorized in a new type of antidiabetic drugs. We had developed a long-acting dipeptidyl peptidase IV inhibitor, K579 [(S)-1-[4-methyl-1-(2-pyrimidinyl)-4-piperidylamino]acetyl-2-pyrrolidinecarbonitrile]. The aim of present study was to characterize the pharmacological profiles of K579. In normal rats, K579 suppressed the blood glucose elevation after an oral glucose tolerance test with the increment of plasma insulin and active forms of glucagon-like peptide-1 (GLP-1). During repetitive glucose loading using Zucker fatty rats, pretreatment with K579 attenuated the glucose excursion after the second glucose loading as well as the first glucose loading without inducing hypoglycemia. The kinetic study using cell extract revealed that K579 was a more potent and slower binding inhibitor than the existing dipeptidyl peptidase IV inhibitor (NVP-DPP728, 1-[[[2-[(5-cyanopyridin-2-yl)amino]ethyl]amino]acetyl]-2-cyano-(S)-pyrrolidine). These profiles of K579 might be advantageous over the existing dipeptidyl peptidase IV inhibitor with respect to less dosing frequency.
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Affiliation(s)
- Kotaro Takasaki
- Pharmaceutical Research Institute, Kyowa Hakko Kogyo Co, Ltd, 1188 Shimotogari, Nagaizumi-cho, Sunto-gun, Shizuoka-ken, 411-8731, Japan.
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22
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Villhauer EB, Brinkman JA, Naderi GB, Burkey BF, Dunning BE, Prasad K, Mangold BL, Russell ME, Hughes TE. 1-[[(3-hydroxy-1-adamantyl)amino]acetyl]-2-cyano-(S)-pyrrolidine: a potent, selective, and orally bioavailable dipeptidyl peptidase IV inhibitor with antihyperglycemic properties. J Med Chem 2003; 46:2774-89. [PMID: 12801240 DOI: 10.1021/jm030091l] [Citation(s) in RCA: 483] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Dipeptidyl peptidase IV (DPP-IV) inhibition has the potential to become a valuable therapy for type 2 diabetes. The synthesis and structure-activity relationship of a new DPP-IV inhibitor class, N-substituted-glycyl-2-cyanopyrrolidines, are described as well as the path that led from clinical development compound 1-[2-[5-cyanopyridin-2-yl)amino]ethylamino]acetyl-2-cyano-(S)-pyrrolidine (NVP-DPP728, 8c) to its follow-up, 1-[[(3-hydroxy-1-adamantyl) amino]acetyl]-2-cyano-(S)-pyrrolidine (NVP-LAF237, 12j). The pharmacological profile of 12j in obese Zucker fa/fa rats along with pharmacokinetic profile comparison of 8c and 12j in normal cynomolgus monkeys is discussed. The results suggest that 12j is a potent, stable, selective DPP-IV inhibitor possessing excellent oral bioavailability and potent antihyperglycemic activity with potential for once-a-day administration.
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Affiliation(s)
- Edwin B Villhauer
- Novartis Institute for Biomedical Research, One Health Plaza, East Hanover, New Jersey 07936, USA.
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23
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Tellgren A, Wood TJJ, Flores-Morales A, Torndal UB, Eriksson L, Norstedt G. Differentially expressed transcripts in neoplastic hepatic nodules and neonatal rat liver studied by cDNA microarray analysis. Int J Cancer 2003; 104:131-8. [PMID: 12569566 DOI: 10.1002/ijc.10946] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The molecular mechanisms underlying hepatocarcinogenesis remain unclear. Wistar rats treated with 2-AAF develop hepatocarcinoma in histologically well-characterised stages. In our study, cDNA microarrays were used to measure the expression of 3,000 genes during the progression of liver carcinogenesis in persistent neoplastic nodules. Because tumours frequently revert into a more poorly differentiated phenotype, we also studied the expression of the same set of transcripts in neonatal rat liver. Approximately 2,000 transcripts gave a detectable signal in experiments comparing gene expression in nodules and control tissue. Approximately 8% of these were identified as differentially expressed in liver nodules. The differentially expressed genes fell into several categories with putative or demonstrated roles in signal transduction, metabolism, detoxification, cell-structure and transport. Many of the differentially expressed genes in nodules were not previously known to be regulated during liver carcinogenesis. A universal transcript profile for gene expression in hepatic liver nodules and neonatal liver has been created.
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Affiliation(s)
- Asa Tellgren
- Department of Molecular Medicine, Karolinska Institute, Karolinska Hospital, Stockholm, Sweden
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24
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Ikeda I, Matsuoka R, Hamada T, Mitsui K, Imabayashi S, Uchino A, Sato M, Kuwano E, Itamura T, Yamada K, Tanaka K, Imaizumi K. Cholesterol esterase accelerates intestinal cholesterol absorption. BIOCHIMICA ET BIOPHYSICA ACTA 2002; 1571:34-44. [PMID: 12031288 DOI: 10.1016/s0304-4165(02)00204-0] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Mechanisms of acceleration of cholesterol absorption by cholesterol esterase were investigated in various experimental conditions. Lymphatic recovery of cholesterol intubated as a micellar solution containing phosphatidylcholine (PC) into the duodenum was enhanced by the co-administration of cholesterol esterase in rats drained of bile and pancreatic juice. However, no accelerated incorporation was observed when cholesterol was solubilized in PC-depleted micelles. Cholesterol esterase dose-dependently accelerated the incorporation of cholesterol into differentiated Caco-2 cells, only when cholesterol was solubilized in PC-containing micelles. The accelerated incorporation of cholesterol into Caco-2 cells by cholesterol esterase disappeared when the enzyme was preincubated with a suicide inhibitor of cholesterol esterase. Cholesterol esterase has an activity as phospholipase A(2). When 10% of PC in bile salt micelles was replaced by lysophosphatidylcholine (lysoPC), the incorporation of cholesterol into Caco-2 cells was significantly accelerated. Cholesterol esterase enhanced the incorporation of micellar cholesterol into brush border membranes prepared from the rat jejunum. The addition of cholesterol esterase to bile salt micelles accelerated the release of micellar cholesterol in a dose-dependent manner, only when the micelles contained PC. These observations strongly suggest that cholesterol esterase hydrolyzes PC in bile salt micelles and thereby, accelerating the release of cholesterol from bile salt micelles. This may be a major cause of the acceleration of cholesterol absorption by cholesterol esterase.
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Affiliation(s)
- Ikuo Ikeda
- Laboratory of Nutrition Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, Fukuoka, Japan.
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25
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Coppola GM, Zhang YL, Schuster HF, Russell ME, Hughes TE. 1-Aminomethylisoquinoline-4-carboxylates as novel dipeptidylpeptidase IV inhibitors. Bioorg Med Chem Lett 2000; 10:1555-8. [PMID: 10915049 DOI: 10.1016/s0960-894x(00)00286-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Structure-activity relationship within a series of 1-aminoalkylisoquinoline-4-carboxylates as inhibitors of DPP-IV is described. A primary aminomethyl group is required to maintain biological activity. Substitution of the isoquinoline at the 6- and 8-positions with methoxy groups increases potency to 53 times that of the lead compound SDZ 029-576.
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Affiliation(s)
- G M Coppola
- Metabolic and Cardiovascular Diseases Research, Novartis Institute for Biomedical Research, Summit, NJ 07901, USA.
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26
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Reddy S, Yang W, Taylor DG, Shen XQ, Oxender D, Kust G, Leff T. Mitogen-activated protein kinase regulates transcription of the ApoCIII gene. Involvement of the orphan nuclear receptor HNF4. J Biol Chem 1999; 274:33050-6. [PMID: 10551874 DOI: 10.1074/jbc.274.46.33050] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The transcriptional regulation of the apoCIII gene by hormonal and metabolic signals plays a significant role in determining plasma triglyceride levels. In the current work we demonstrate that the apoCIII gene is regulated by the mitogen-activated protein (MAP) kinase signaling pathway. In HepG2 cells, repression of MAP kinase activity by treatment with the mitogen-activated protein kinase/extracellular signal-regulated kinase kinase inhibitor PD98059 caused a 5-8-fold increase in apoCIII transcriptional activity. Activation of MAP kinase by phorbol ester treatment caused a 3-5-fold reduction in apoCIII transcription. The region of the apoCIII promoter responsible for this regulation was mapped in transiently transfected HepG2 cells to a 6-base pair element located at -740. The major protein binding to this site was identified as the nuclear hormone receptor HNF4. An increase in HNF4 mRNA and protein levels was observed in HepG2 cells after treatment with PD98059, indicating that the MAP kinase pathway regulates the expression of the HNF4 gene. These findings demonstrate that the apoCIII gene can be regulated by signals acting through the MAP kinase pathway and that this regulation is mediated, at least in part, by changes in the amount of HNF4.
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Affiliation(s)
- S Reddy
- Department of Cell Biology, Parke-Davis Research, Ann Arbor, Michigan 48105, USA
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27
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Nuñez MT, Tapia V. Transferrin stimulates iron absorption, exocytosis, and secretion in cultured intestinal cells. THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 276:C1085-90. [PMID: 10329956 DOI: 10.1152/ajpcell.1999.276.5.c1085] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The cellular mechanism by which basolateral transferrin (Tf) produces an increase in apical-to-basolateral Fe flux in Caco-2 cells was analyzed. After a pulse of 59Fe from the apical medium, three types of basolateral 59Fe efflux were found: a 59Fe efflux that was independent of the presence of Tf in the basolateral medium, a 59Fe efflux in which 59Fe left the cell bound to Tf, and a Tf-dependent 59Fe efflux in which 59Fe came off the cell not bound to Tf. Furthermore, addition of Tf to the basolateral medium doubled the exocytosis rate of Tf and increased the secretion of apolipoprotein A, a basolateral secretion marker. Both apotransferrin and Fe-containing Tf produced similar increases in 59Fe efflux, Tf exocytosis, and apolipoprotein A secretion. The Ca2+ channel inhibitor SKF-96365 inhibited both the Tf-mediated increase in transepithelial Fe transport and the secretion of apolipoprotein A. Thus the activation of transepithelial Fe transport by Tf seems to be mediated by Ca2+ entry into the cells.
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Affiliation(s)
- M T Nuñez
- Department of Biology, Faculty of Sciences, University of Chile, Santiago, Chile
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28
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Abstract
Synthesis and secretion of chylomicrons by the intestine is essential to transport dietary fats in the circulation and to deliver these fats to the appropriate peripheral tissues. The assembly of chylomicrons within the enterocyte and the subsequent secretion of these lipoprotein particles into the lymph is a complex, multi-step process that includes absorption of lipids by the enterocytes, cellular lipid (re)synthesis and translocation of cellular lipid pools, synthesis and post-translational modification of various apolipoproteins and, finally, the assembly of lipid and lipoprotein components into a chylomicron. The key process in chylomicron synthesis is the intracellular association of apolipoprotein (apo)B48, the structural protein of chylomicrons, with lipids.
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Affiliation(s)
- M M van Greevenbroek
- Laboratory for Molecular Metabolism and Endocrinology, Maastricht University, The Netherlands
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29
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Luchoomun J, Zhou Z, Bakillah A, Jamil H, Hussain MM. Assembly and secretion of VLDL in nondifferentiated Caco-2 cells stably transfected with human recombinant ApoB48 cDNA. Arterioscler Thromb Vasc Biol 1997; 17:2955-63. [PMID: 9409282 DOI: 10.1161/01.atv.17.11.2955] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Intestinal cells secrete apoB48-containing very low density lipoproteins (VLDLs) and chylomicrons for the transport of biliary and dietary lipids. The molecular mechanisms regulating the assembly of intestinal lipoproteins are not known due to a lack of reliable and specific cell culture models. Caco-2 (a human colon carcinoma) cells have been used to study intestinal lipid metabolism. These cells have been shown to secrete both apoB100- and apoB48-containing triglyceride (TG)-rich lipoproteins only after differentiation into enterocyte-like cells. To study lipoprotein assembly in nondifferentiated Caco-2 cells, we stably expressed human recombinant apoB48 cDNA under the control of a constitutive cytomegalovirus promoter. Pulse-chase analysis revealed that the majority (> 50%) of apoB48 synthesized was degraded intracellularly in the presence or absence of oleic acid. Transfected nondifferentiated cells secreted lipoproteins with flotation densities similar to those of plasma HDL or LDL when cultured in serum-free or serum-containing media, respectively. Incubation of cells with media containing serum and oleic acid resulted in the secretion of VLDL-like particles. Secretion of VLDL was inhibited (> 80%) by triacsin C due to > 60% inhibition of oleate-induced TG synthesis. However, inhibition of cholesteryl ester synthesis by 70% with an acyl coenzyme A:cholesterol acyltransferase inhibitor did not affect VLDL secretion. Efficient assembly of lipoproteins usually requires the microsomal TG transfer protein (MTP). The presence of MTP in transfected Caco-2 cells was investigated by measuring TG transfer activity in microsomal fractions. Microsomal fractions had 0.2% TG transfer activity per hour per microgram of protein, which corresponds to 30% to 60% of the MTP activity present in liver-derived cells. To determine whether MTP activity was required for lipoprotein assembly, transfected cells were incubated in the presence of the MTP inhibitor CP-10,447. This compound completely abolished the secretion of apoB. These data show that the transfected cell lines secrete lipoproteins of different densities under different culture conditions and that the assembly of larger VLDL particles requires active TG synthesis and MTP activity. Thus, in nondifferentiated Caco-2 cells, the amount of apoB secreted and not the MTP activity is the limiting factor for lipoprotein assembly.
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Affiliation(s)
- J Luchoomun
- Department of Pathology, Allegheny University of the Health Sciences, MCP Hahnemann School of Medicine, Philadelphia, Pa. 19129, USA
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30
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Le Beyec J, Delers F, Jourdant F, Schreider C, Chambaz J, Cardot P, Pinçon-Raymond M. A complete epithelial organization of Caco-2 cells induces I-FABP and potentializes apolipoprotein gene expression. Exp Cell Res 1997; 236:311-20. [PMID: 9344612 DOI: 10.1006/excr.1997.3734] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The culture of Caco-2 cells on plastic support impairs the expression of several genes involved in lipid metabolism. We describe culture conditions that permit the expression of the I-FABP gene and better expression of the apolipoprotein A-I, C-III, and A-IV genes. Basal lamina deposited on filters as well as the nature of nutrients on the apical side differentially modulated mRNA expression of I-FABP, APOBEC-1, and apolipoprotein genes. Growing cells on a filter led to functional polarization, illustrated by a secretion of apo B at the basal side, which induced the expression of the I-FABP, APOBEC-1, and apo A-IV genes and highly increased the expression of the apo C-III gene. Moreover, basal lamina deposited on the filter enhances the mRNA expression of apo A-I. Apo C-III and A-IV mRNA levels were decreased when cells were grown on a filter covered with basal lamina in the presence of a medium deprived of protein and lipid on the apical side, whereas these conditions had no effect on I-FABP, apo A-I, and APOBEC-1 mRNA levels. The addition of lipid micelles on the apical side had various effects, according to the genes. Caco-2 cells cultured under the conditions described here closely resembled enterocytes and represent a useful tool for studying the regulation of genes involved in lipid metabolism.
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Affiliation(s)
- J Le Beyec
- INSERM CJF 9508, CNRS URA 1283, Université Pierre et Marie Curie, Paris, France
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31
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Naganawa S, Ginsberg HN, Glickman RM, Ginsburg GS. Intestinal transcription and synthesis of apolipoprotein AI is regulated by five natural polymorphisms upstream of the apolipoprotein CIII gene. J Clin Invest 1997; 99:1958-65. [PMID: 9109440 PMCID: PMC508020 DOI: 10.1172/jci119363] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
To understand the factors contributing to the synthesis of human apolipoprotein AI (apoAI), relative apoAI synthesis was measured from endoscopic biopsy samples obtained from 18 healthy volunteers. The relative amount of apoAI synthesis was directly correlated with steady state intestinal apoAI mRNA levels and a 10-fold within-group variability was observed. Analysis of genomic DNA from the subjects revealed five polymorphic sites which defined two haplotypes in the intestinal enhancer region of the apoAI gene located upstream of the apolipoprotein CIII gene transcriptional start site (+ 1): (-641 C to A, -630 G to A, -625 T to deletion, -482 C to T, and -455 T to C). The population frequencies of the wild-type and mutant alleles were 0.53 and 0.44, respectively. Mean steady state apoAI mRNA levels and mean relative apoAI synthesis were 49 and 37% lower, respectively, in homozygotes for the mutant allele and 28 and 41% lower, respectively, in heterozygotes than in homozygotes for the wild-type allele (P < 0.05 for both). Site-directed mutants of apoAI gene promoter/reporter constructs containing the above mutations were transfected into Caco-2 cells and showed a 46% decrease in transcriptional activity compared with the wild type (P < 0.001); however, no significant differences were observed in HepG2 cells. Electrophoretic mobility shift assays showed that the mutated sequences from -655 to -610 bound Caco-2 cell nuclear protein(s) while the wild type did not. These results indicate that intestinal apoAI gene transcription and protein synthesis are genetically determined and are reduced in the presence of common mutations which induced binding of nuclear protein(s), possibly a transcriptional repressor.
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Affiliation(s)
- S Naganawa
- Department of Medicine, Beth Israel Hospital, Boston, Massachusetts 02215, USA
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32
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Tranchant T, Besson P, Hoinard C, Delarue J, Antoine JM, Couet C, Goré J. Mechanisms and kinetics of alpha-linolenic acid uptake in Caco-2 clone TC7. BIOCHIMICA ET BIOPHYSICA ACTA 1997; 1345:151-61. [PMID: 9106494 DOI: 10.1016/s0005-2760(96)00171-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The uptake kinetics of alpha-linolenic acid (18:3(n - 3)), an essential fatty acid, were investigated in the human intestinal cell line Caco-2. Four clones (PD10, PF11, PD7 and TC7) from the heterogeneous parental Caco-2 cells population were used. After a screening step using isolated cells, the TC7 clone was selected for the study of alpha-linolenic acid uptake. [1-(14)C]linolenic acid dissolved in 10 mM taurocholate was presented to the microvillus plasma membrane (apical side) of TC7 differentiated cells, grown on a semi-permeable polycarbonate membrane. The results show that the initial rate of uptake is not a linear function of the 18:3(n- 3) monomer concentration in the incubation medium. In the monomer concentration range studied (0.2 to 36 microM) apical uptake was saturable and followed Michaelis-Menten kinetics (V(max) = 15.4 +/- 0.6 nmol/mg protein per min, K(m) = 14.3 +/- 1.3 microM). In addition, it was temperature- and energy-dependent but was apparently unaffected by the sodium gradient and intracellular metabolic fate of 18:3(n - 3). Excess of unlabeled saturated or unsaturated long chain fatty acids (C16 to C22) led to a 27-68% reduction of [1-(14)C]linolenic acid uptake. Likewise basolateral uptake was saturable (V(max) = 4.9 +/- 0.7 nmol/mg protein per min, K(m) = 8.7 +/- 2.9 microM). These facts argue in favour of the existence in these human intestinal cells of a carrier-mediated transport system for alpha-linolenic acid and probably other long chain fatty acids as well.
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Affiliation(s)
- T Tranchant
- Laboratoire de Nutrition, Faculté de Médecine, Université de Tours, France
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33
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Ye H, Kelly TF, Samadani U, Lim L, Rubio S, Overdier DG, Roebuck KA, Costa RH. Hepatocyte nuclear factor 3/fork head homolog 11 is expressed in proliferating epithelial and mesenchymal cells of embryonic and adult tissues. Mol Cell Biol 1997; 17:1626-41. [PMID: 9032290 PMCID: PMC231888 DOI: 10.1128/mcb.17.3.1626] [Citation(s) in RCA: 297] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The hepatocyte nuclear factor 3alpha (HNF-3alpha) and 3beta proteins have homology in the winged helix/fork head DNA binding domain and regulate cell-specific transcription in hepatocytes and in respiratory and intestinal epithelia. In this study, we describe two novel isoforms of the winged helix transcription factor family, HNF-3/fork head homolog 11A (HFH-11A) and HFH-11B, isolated from the human colon carcinoma HT-29 cell line. We show that these isoforms arise via differential splicing and are expressed in a number of epithelial cell lines derived from tumors (HT-29, Caco-2, HepG2, HeLa, A549, and H441). We demonstrate that differentiation of Caco-2 cells toward the enterocyte lineage results in decreased HFH-11 expression and reciprocal increases in HNF-3alpha and HNF-3beta mRNA levels. In situ hybridization of 16 day postcoitus mouse embryos demonstrates that HFH-11 expression is found in the mesenchymal and epithelial cells of the liver, lung, intestine, renal cortex, and urinary tract. Although HFH-11 exhibits a wide cellular expression pattern in the embryo, its adult expression pattern is restricted to epithelial cells of Lieberkühn's crypts of the intestine, the spermatocytes and spermatids of the testis, and the thymus and colon. HFH-11 expression is absent in adult hepatocytes, but its expression is reactivated in proliferating hepatocytes at 4, 24, and 48 h after partial hepatectomy. Consistent with these findings, we demonstrate that HFH-11 mRNA levels are stimulated by intratracheal administration of keratinocyte growth factor in adult lung and its expression in an adult endothelial cell line is reactivated in response to oxidative stress. These experiments show that the HFH-11 transcription factor is expressed in embryonic mesenchymal and epithelial cells and its expression is reactivated in these adult cell types by proliferative signals or oxidative stress.
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Affiliation(s)
- H Ye
- Department of Biochemistry, University of Illinois at Chicago, 60612-7334, USA
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34
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Mehran M, Levy E, Bendayan M, Seidman E. Lipid, apolipoprotein, and lipoprotein synthesis and secretion during cellular differentiation in Caco-2 cells. In Vitro Cell Dev Biol Anim 1997; 33:118-28. [PMID: 9081219 DOI: 10.1007/s11626-997-0032-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Although Caco-2 cells are frequently employed for the study of enterocyte lipid metabolism, variable results have been reported regarding their ability to synthesize and secrete lipids and apolipoproteins. The major goal of this investigation is to examine the capacity of Caco-2 cells to elaborate and secrete lipids, lipoproteins, and apolipoproteins at different degrees of morphological and functional differentiation. Cells were cultured in medium with 5% fetal bovine serum (FBS), on permeable polycarbonate filters from 2 to 30 d in the presence of 14C-oleate or 35S-methionine. Cellular differentiation, as assessed by morphology (light and electron microscopy), transepithelial resistance, free fatty acid flux, and sucrase activity, progressed steadily up to 20 d of culture. Caco-2 cells esterified oleic acid mainly into phospholipids, triglycerides (TG), and smaller amounts of cholesterol esters. Lipid synthesis began as early as 2 d, and TG secretion was enhanced with increased duration of culture. However, very low efficiency of lipid export was observed at all levels of differentiation, reaching a maximum of only 6% of intracellular lipids. VLDL and LDL were the dominant lipoproteins secreted, with HDL comprising < 20% of the total. VLDL secretion increased, while LDL decreased, whereas the lipid composition of lipoproteins varied little with increasing duration of culture. Apoprotein B and A-I synthesis and secretion increased markedly from 11 to 20 d of culture. The ratio of apo B-100/B-48 decreased between 11 and 30 d, consistent with enhanced apo B editing of more mature enterocytes. Taken together, our data suggest that from 20 d of culture, Caco-2 cells are morphologically and functionally mature, capable of lipid esterification, and lipoprotein and apolipoprotein synthesis. However, despite their functional and morphological similarities to mature enterocytes, Caco-2 cells have a very limited lipid export capacity.
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Affiliation(s)
- M Mehran
- Hôpital Ste.-Justine, Department of Pediatrics, Faculty of Medicine, Université de Montréal, Quebec, Canada
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35
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Kardassis D, Tzameli I, Hadzopoulou-Cladaras M, Talianidis I, Zannis V. Distal apolipoprotein C-III regulatory elements F to J act as a general modular enhancer for proximal promoters that contain hormone response elements. Synergism between hepatic nuclear factor-4 molecules bound to the proximal promoter and distal enhancer sites. Arterioscler Thromb Vasc Biol 1997; 17:222-32. [PMID: 9012660 DOI: 10.1161/01.atv.17.1.222] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Transient transfection assays have shown that the distal apoC-III promoter segments that contain the regulatory elements F to J enhance the strength of the tandemly linked proximal apoA-I promoter 5- to 13-fold in hepatic (HepG2) cells. Activation in intestinal (CaCo-2) cells to levels comparable to those obtained in HepG2 cells requires a larger apoA-I promoter sequence that extends to nucleotide -1500 as well as the presence of hepatic nuclear factor-4 (HNF-4). The distal apoC-III regulatory elements can also enhance 4- to 8-fold the strength of the heterologous apoB promoter in HepG2 and CaCo-2 cells. Finally, these elements in the presence of HNF-4 enhance 14.5- to 18.5-fold the strength of the minimal adenovirus major late promoter linked to two copies of the hormone response element (HRE) AID of apoA-I in both HepG2 and CaCo-2 cells. In vitro mutagenesis of the promoter/enhancer cluster established that the enhancer activity is lost by a mutation in the HRE present in the 3' end of the regulatory element I (-736 to -714) and is reduced significantly by point mutations or deletions in one or more of the regulatory elements F to J of the apoC-III enhancer. The enhancer activity also requires the HREs of the proximal apoA-I promoter. The apoC-III enhancer can also restore the activity of the proximal apoA-I and apoB promoters that have been inactivated by mutations in CCAAT/enhancers binding protein binding sites, indicating that C/EBP may not participate in the synergistic activation of the promoter/enhancer cluster. The findings suggest that the regulatory elements F to J of the apoC-III promoter act as a general modular enhancer that can potentiate the strength of proximal promoters that contain HREs. Such potentiation in the HepG2 cells can be accounted for by synergistic interactions between HNF-4 or other nuclear hormone receptors bound to the proximal and distal HREs and SP1 or other factors bound to the apoC-III enhancer. Additional factors may be required for optimal activity in CaCo-2 cells as well as for the function of this region as an intestinal enhancer.
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Affiliation(s)
- D Kardassis
- Department of Medicine, University of Crete, Greece
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36
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Giannoni F, Field FJ, Davidson NO. An improved reverse transcription-polymerase chain reaction method to study apolipoprotein gene expression in Caco-2 cells. J Lipid Res 1994. [DOI: 10.1016/s0022-2275(20)41222-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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