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Lasocka-Koriat Z, Lewicka-Potocka Z, Kaleta-Duss A, Siekierzycka A, Kalinowski L, Lewicka E, Dąbrowska-Kugacka A. Differences in cardiac adaptation to exercise in male and female athletes assessed by noninvasive techniques: a state-of-the-art review. Am J Physiol Heart Circ Physiol 2024; 326:H1065-H1079. [PMID: 38391314 DOI: 10.1152/ajpheart.00756.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 02/20/2024] [Accepted: 02/20/2024] [Indexed: 02/24/2024]
Abstract
Athlete's heart is generally regarded as a physiological adaptation to regular training, with specific morphological and functional alterations in the cardiovascular system. Development of the noninvasive imaging techniques over the past several years enabled better assessment of cardiac remodeling in athletes, which may eventually mimic certain pathological conditions with the potential for sudden cardiac death, or disease progression. The current literature provides a compelling overview of the available methods that target the interrelation of prolonged exercise with cardiac structure and function. However, this data stems from scientific studies that included mostly male athletes. Despite the growing participation of females in competitive sport meetings, little is known about the long-term cardiac effects of repetitive training in this population. There are several factors-biochemical, physiological and psychological, that determine sex-dependent cardiac response. Herein, the aim of this review was to compare cardiac adaptation to endurance exercise in male and female athletes with the use of electrocardiographic, echocardiographic, and biochemical examination, to determine the sex-specific phenotypes, and to improve the healthcare providers' awareness of cardiac remodeling in athletes. Finally, we discuss the possible exercise-induced alternations that should arouse suspicion of pathology and be further evaluated.
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Affiliation(s)
- Zofia Lasocka-Koriat
- Department of Cardiology and Electrotherapy, Medical University of Gdańsk, Gdańsk, Poland
- First Department of Cardiology, Medical University of Gdańsk, Gdańsk, Poland
| | - Zuzanna Lewicka-Potocka
- Department of Cardiology and Electrotherapy, Medical University of Gdańsk, Gdańsk, Poland
- First Department of Cardiology, Medical University of Gdańsk, Gdańsk, Poland
| | - Anna Kaleta-Duss
- Institute for Radiology, Cantonal Hospital Aarau, Aarau, Switzerland
| | - Anna Siekierzycka
- Department of Medical Laboratory Diagnostics-Fahrenheit Biobank BBMRI.pl, Medical University of Gdańsk, Gdańsk, Poland
| | - Leszek Kalinowski
- Department of Medical Laboratory Diagnostics-Fahrenheit Biobank BBMRI.pl, Medical University of Gdańsk, Gdańsk, Poland
- BioTechMed Centre/Department of Mechanics of Materials and Structures, Gdańsk University of Technology, Gdańsk, Poland
| | - Ewa Lewicka
- Department of Cardiology and Electrotherapy, Medical University of Gdańsk, Gdańsk, Poland
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Diethyldithiocarbamate inhibits the activation of hepatic stellate cells via PPARα/FABP1 in mice with non-alcoholic steatohepatitis. Biochem Biophys Res Commun 2023; 641:192-199. [PMID: 36535078 DOI: 10.1016/j.bbrc.2022.12.039] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 12/09/2022] [Accepted: 12/12/2022] [Indexed: 12/15/2022]
Abstract
Activation of hepatic stellate cells (HSCs) is the main course of liver fibrosis which is positively correlated with adverse clinical outcomes in non-alcoholic steatohepatitis (NASH). Diethyldithiocarbamate (DDC) attenuates NASH related liver fibrosis in mice, but its underlying mechanisms remains unclear. In this study, the data showed that DDC inhibited the activation of HSCs in high fat choline-deficient, L-amino acid-defined (CDAA) diet induced NASH. Double Immunofluorescence analysis showed that the baseline expression of peroxisome proliferator-activated receptor α (PPARα) is high in HSCs in normal mouse liver and notably decreases in the NASH liver, indicating that PPARα might be associated with the activation of HSCs. While, DDC upregulated PPARα in HSCs in the NASH liver. Mixture of free fatty acid was used to induce steatosis of hepatocytes. Human HSCs (LX-2 cells) were activated after co-cultured with steatotic hepatocytes, and DDC inhibited the activation of LX-2 cells. Meanwhile, DDC upregulated PPARα and FABP1, and promoted the accumulation of LDs in LX-2 cells. PPARα small interfering RNA blocked these effect of DDC. These findings suggest that PPARα is associated with the activation of HSCs in the context of NASH. DDC improves NASH related fibrosis through inhibiting the activation of HSCs via PPARα/FABP1.
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Lackey AI, Chen T, Zhou YX, Bottasso Arias NM, Doran JM, Zacharisen SM, Gajda AM, Jonsson WO, Córsico B, Anthony TG, Joseph LB, Storch J. Mechanisms underlying reduced weight gain in intestinal fatty acid-binding protein (IFABP) null mice. Am J Physiol Gastrointest Liver Physiol 2020; 318:G518-G530. [PMID: 31905021 PMCID: PMC7099495 DOI: 10.1152/ajpgi.00120.2019] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 12/13/2019] [Accepted: 12/13/2019] [Indexed: 02/06/2023]
Abstract
Intestinal-fatty acid binding protein (IFABP; FABP2) is a 15-kDa intracellular protein abundantly present in the cytosol of the small intestinal (SI) enterocyte. High-fat (HF) feeding of IFABP-/- mice resulted in reduced weight gain and fat mass relative to wild-type (WT) mice. Here, we examined intestinal properties that may underlie the observed lean phenotype of high fat-fed IFABP-/- mice. No alterations in fecal lipid content were found, suggesting that the IFABP-/- mice are not malabsorbing dietary fat. However, the total excreted fecal mass, normalized to food intake, was increased for the IFABP-/- mice relative to WT mice. Moreover, intestinal transit time was more rapid in the IFABP-/- mice. IFABP-/- mice displayed a shortened average villus length, a thinner muscularis layer, reduced goblet cell density, and reduced Paneth cell abundance. The number of proliferating cells in the crypts of IFABP-/- mice did not differ from that of WT mice, suggesting that the blunt villi phenotype is not due to alterations in proliferation. IFABP-/- mice were observed to have altered expression of genes and proteins related to intestinal structure, while immunohistochemical analyses revealed increased staining for markers of inflammation. Taken together, these studies indicate that the ablation of IFABP, coupled with high-fat feeding, leads to changes in gut motility and morphology, which likely contribute to the relatively leaner phenotype occurring at the whole-body level. Thus, IFABP is likely involved in dietary lipid sensing and signaling, influencing intestinal motility, intestinal structure, and nutrient absorption, thereby impacting systemic energy metabolism.NEW & NOTEWORTHY Intestinal fatty acid binding protein (IFABP) is thought to be essential for the efficient uptake and trafficking of dietary fatty acids. In this study, we demonstrate that high-fat-fed IFABP-/- mice have an increased fecal output and are likely malabsorbing other nutrients in addition to lipid. Furthermore, we observe that the ablation of IFABP leads to marked alterations in intestinal morphology and secretory cell abundance.
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Affiliation(s)
- Atreju I Lackey
- Department of Nutritional Sciences, Rutgers University, New Brunswick, New Jersey
- Rutgers Center for Lipid Research, New Brunswick, New Jersey
| | - Tina Chen
- Department of Nutritional Sciences, Rutgers University, New Brunswick, New Jersey
| | - Yin X Zhou
- Department of Nutritional Sciences, Rutgers University, New Brunswick, New Jersey
| | - Natalia M Bottasso Arias
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), CCT CONICET, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Argentina
| | - Justine M Doran
- Department of Nutritional Sciences, Rutgers University, New Brunswick, New Jersey
| | - Sophia M Zacharisen
- Department of Nutritional Sciences, Rutgers University, New Brunswick, New Jersey
| | - Angela M Gajda
- Department of Nutritional Sciences, Rutgers University, New Brunswick, New Jersey
- Rutgers Center for Lipid Research, New Brunswick, New Jersey
| | - William O Jonsson
- Department of Nutritional Sciences, Rutgers University, New Brunswick, New Jersey
- Rutgers Center for Lipid Research, New Brunswick, New Jersey
| | - Betina Córsico
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), CCT CONICET, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Argentina
| | - Tracy G Anthony
- Department of Nutritional Sciences, Rutgers University, New Brunswick, New Jersey
- Rutgers Center for Lipid Research, New Brunswick, New Jersey
| | - Laurie B Joseph
- Rutgers Center for Lipid Research, New Brunswick, New Jersey
- Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Rutgers University, New Brunswick, New Jersey
| | - Judith Storch
- Department of Nutritional Sciences, Rutgers University, New Brunswick, New Jersey
- Rutgers Center for Lipid Research, New Brunswick, New Jersey
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4
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North MK, Dalle Zotte A, Hoffman LC. The effects of dietary quercetin supplementation and sex on the fatty acid profile of rabbit meat, dissectible fat and caecotrophes. Meat Sci 2019; 157:107888. [DOI: 10.1016/j.meatsci.2019.107888] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 05/31/2019] [Accepted: 07/10/2019] [Indexed: 12/13/2022]
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Sané A, Seidman E, Spahis S, Lamantia V, Garofalo C, Montoudis A, Marcil V, Levy E. New Insights In Intestinal Sar1B GTPase Regulation and Role in Cholesterol Homeostasis. J Cell Biochem 2016; 116:2270-82. [PMID: 25826777 DOI: 10.1002/jcb.25177] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 03/25/2015] [Indexed: 12/12/2022]
Abstract
Sar1B GTPase is a key component of Coat protein complex II (COPII)-coated vesicles that bud from the endoplasmic reticulum to export newly synthesized proteins. The aims of this study were to determine whether Sar1B responds to lipid regulation and to evaluate its role in cholesterol (CHOL) homeostasis. The influence of lipids on Sar1B protein expression was analyzed in Caco-2/15 cells by Western blot. Our results showed that the presence of CHOL (200 μM) and oleic acid (0.5 mM), bound to albumin, increases Sar1B protein expression. Similarly, supplementation of the medium with micelles composed of taurocholate with monooleylglycerol or oleic acid also stimulated Sar1B expression, but the addition of CHOL (200 μM) to micelle content did not modify its regulation. On the other hand, overexpression of Sar1B impacted on CHOL transport and metabolism in view of the reduced cellular CHOL content along with elevated secretion when incubated with oleic acid-containing micelles for 24 h, thereby disclosing induced CHOL transport. This was accompanied with higher secretion of free- and esterified-CHOL within chylomicrons, which was not the case when oleic acid was replaced with monooleylglycerol or when albumin-bound CHOL was given alone. The aforementioned cellular CHOL depletion was accompanied with a low phosphorylated/non phosphorylated HMG-CoA reductase ratio, indicating elevated enzymatic activity. Combination of Sar1B overexpression with micelle incubation led to reduction in intestinal CHOL transporters (NPC1L1, SR-BI) and metabolic regulators (PCSK9 and LDLR). The present work showed that Sar1B is regulated in a time- and concentration-dependent manner by dietary lipids, suggesting an adaptation to alimentary lipid flux. Our data also suggest that Sar1B overexpression contributes to regulation of CHOL transport and metabolism by facilitating rapid uptake and transport of CHOL.
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Affiliation(s)
- Alain Sané
- Research Centre, CHU-Sainte-Justine, Université de Montréal, Montreal, Quebec, Canada, H3T 1C5
| | - Ernest Seidman
- Research Institute, McGill University, Campus MGH, C10.148.6, Montreal, Quebec, Canada, H3G 1A4
| | - Schohraya Spahis
- Research Centre, CHU-Sainte-Justine, Université de Montréal, Montreal, Quebec, Canada, H3T 1C5.,Department of Nutrition, Université de Montréal, Montreal, Quebec, Canada, H3T 1A8
| | - Valérie Lamantia
- Research Centre, CHU-Sainte-Justine, Université de Montréal, Montreal, Quebec, Canada, H3T 1C5
| | - Carole Garofalo
- Research Centre, CHU-Sainte-Justine, Université de Montréal, Montreal, Quebec, Canada, H3T 1C5
| | - Alain Montoudis
- Research Centre, CHU-Sainte-Justine, Université de Montréal, Montreal, Quebec, Canada, H3T 1C5
| | - Valérie Marcil
- Research Centre, CHU-Sainte-Justine, Université de Montréal, Montreal, Quebec, Canada, H3T 1C5.,Research Institute, McGill University, Campus MGH, C10.148.6, Montreal, Quebec, Canada, H3G 1A4
| | - Emile Levy
- Research Centre, CHU-Sainte-Justine, Université de Montréal, Montreal, Quebec, Canada, H3T 1C5.,Department of Nutrition, Université de Montréal, Montreal, Quebec, Canada, H3T 1A8
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6
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Wang G, Bonkovsky HL, de Lemos A, Burczynski FJ. Recent insights into the biological functions of liver fatty acid binding protein 1. J Lipid Res 2015; 56:2238-47. [PMID: 26443794 DOI: 10.1194/jlr.r056705] [Citation(s) in RCA: 144] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Indexed: 12/18/2022] Open
Abstract
Over four decades have passed since liver fatty acid binding protein (FABP)1 was first isolated. There are few protein families for which most of the complete tertiary structures, binding properties, and tissue occurrences are described in such detail and yet new functions are being uncovered for this protein. FABP1 is known to be critical for fatty acid uptake and intracellular transport and also has an important role in regulating lipid metabolism and cellular signaling pathways. FABP1 is an important endogenous cytoprotectant, minimizing hepatocyte oxidative damage and interfering with ischemia-reperfusion and other hepatic injuries. The protein may be targeted for metabolic activation through the cross-talk among many transcriptional factors and their activating ligands. Deficiency or malfunction of FABP1 has been reported in several diseases. FABP1 also influences cell proliferation during liver regeneration and may be considered as a prognostic factor for hepatic surgery. FABP1 binds and modulates the action of many molecules such as fatty acids, heme, and other metalloporphyrins. The ability to bind heme is another cytoprotective property and one that deserves closer investigation. The role of FABP1 in substrate availability and in protection from oxidative stress suggests that FABP1 plays a pivotal role during intracellular bacterial/viral infections by reducing inflammation and the adverse effects of starvation (energy deficiency).
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Affiliation(s)
- GuQi Wang
- Jiangxi Normal University, Nanchang, Jiangxi, People's Republic of China Department of Biology, University of North Carolina at Charlotte, Charlotte, NC Carolinas HealthCare System, Charlotte, NC
| | - Herbert L Bonkovsky
- Department of Biology, University of North Carolina at Charlotte, Charlotte, NC Carolinas HealthCare System, Charlotte, NC Wake Forest Baptist Medical Center, Winston-Salem, NC
| | - Andrew de Lemos
- Carolinas HealthCare System, Charlotte, NC Wake Forest Baptist Medical Center, Winston-Salem, NC
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7
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Gajda AM, Storch J. Enterocyte fatty acid-binding proteins (FABPs): different functions of liver and intestinal FABPs in the intestine. Prostaglandins Leukot Essent Fatty Acids 2015; 93:9-16. [PMID: 25458898 PMCID: PMC4323920 DOI: 10.1016/j.plefa.2014.10.001] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Accepted: 10/03/2014] [Indexed: 02/07/2023]
Abstract
Fatty acid-binding proteins (FABP) are highly abundant cytosolic proteins that are expressed in most mammalian tissues. In the intestinal enterocyte, both liver- (LFABP; FABP1) and intestinal FABPs (IFABP; FABP2) are expressed. These proteins display high-affinity binding for long-chain fatty acids (FA) and other hydrophobic ligands; thus, they are believed to be involved with uptake and trafficking of lipids in the intestine. In vitro studies have identified differences in ligand-binding stoichiometry and specificity, and in mechanisms of FA transfer to membranes, and it has been hypothesized that LFABP and IFABP have different functions in the enterocyte. Studies directly comparing LFABP- and IFABP-null mice have revealed markedly different phenotypes, indicating that these proteins indeed have different functions in intestinal lipid metabolism and whole body energy homeostasis. In this review, we discuss the evolving knowledge of the functions of LFABP and IFABP in the intestinal enterocyte.
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Affiliation(s)
- Angela M Gajda
- Department of Nutritional Sciences and Rutgers Center for Lipid Research Rutgers University, New Brunswick, NJ 08901, USA
| | - Judith Storch
- Department of Nutritional Sciences and Rutgers Center for Lipid Research Rutgers University, New Brunswick, NJ 08901, USA.
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8
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Gajda AM, Zhou YX, Agellon LB, Fried SK, Kodukula S, Fortson W, Patel K, Storch J. Direct comparison of mice null for liver or intestinal fatty acid-binding proteins reveals highly divergent phenotypic responses to high fat feeding. J Biol Chem 2013; 288:30330-30344. [PMID: 23990461 DOI: 10.1074/jbc.m113.501676] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The enterocyte expresses two fatty acid-binding proteins (FABP), intestinal FABP (IFABP; FABP2) and liver FABP (LFABP; FABP1). LFABP is also expressed in liver. Despite ligand transport and binding differences, it has remained uncertain whether these intestinally coexpressed proteins, which both bind long chain fatty acids (FA), are functionally distinct. Here, we directly compared IFABP(-/-) and LFABP(-/-) mice fed high fat diets containing long chain saturated or unsaturated fatty acids, reasoning that providing an abundance of dietary lipid would reveal unique functional properties. The results showed that mucosal lipid metabolism was indeed differentially modified, with significant decreases in FA incorporation into triacylglycerol (TG) relative to phospholipid (PL) in IFABP(-/-) mice, whereas LFABP(-/-) mice had reduced monoacylglycerol incorporation in TG relative to PL, as well as reduced FA oxidation. Interestingly, striking differences were found in whole body energy homeostasis; LFABP(-/-) mice fed high fat diets became obese relative to WT, whereas IFABP(-/-) mice displayed an opposite, lean phenotype. Fuel utilization followed adiposity, with LFABP(-/-) mice preferentially utilizing lipids, and IFABP(-/-) mice preferentially metabolizing carbohydrate for energy production. Changes in body weight and fat may arise, in part, from altered food intake; mucosal levels of the endocannabinoids 2-arachidonoylglycerol and arachidonoylethanolamine were elevated in LFABP(-/-), perhaps contributing to increased energy intake. This direct comparison provides evidence that LFABP and IFABP have distinct roles in intestinal lipid metabolism; differential intracellular functions in intestine and in liver, for LFABP(-/-) mice, result in divergent downstream effects at the systemic level.
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Affiliation(s)
- Angela M Gajda
- From the Department of Nutritional Sciences and; the Rutgers Center for Lipid Research, Rutgers University, New Brunswick, New Jersey 08901
| | | | - Luis B Agellon
- the School of Dietetics and Human Nutrition, McGill University, Montréal, Québec H9X 3V9, Canada, and
| | - Susan K Fried
- the Department of Medicine, Boston University School of Medicine, Boston, Massachusetts 02118
| | | | | | | | - Judith Storch
- From the Department of Nutritional Sciences and; the Rutgers Center for Lipid Research, Rutgers University, New Brunswick, New Jersey 08901,.
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9
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Siddiqi S, Sheth A, Patel F, Barnes M, Mansbach CM. Intestinal caveolin-1 is important for dietary fatty acid absorption. BIOCHIMICA ET BIOPHYSICA ACTA 2013; 1831:1311-21. [PMID: 23665238 PMCID: PMC3751415 DOI: 10.1016/j.bbalip.2013.05.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Revised: 04/29/2013] [Accepted: 05/01/2013] [Indexed: 12/16/2022]
Abstract
How dietary fatty acids are absorbed into the enterocyte and transported to the ER is not established. We tested the possibility that caveolin-1 containing lipid rafts and endocytic vesicles were involved. Apical brush border membranes took up 15% of albumin bound (3)H-oleate whereas brush border membranes from caveolin-1 KO mice took up only 1%. In brush border membranes, the (3)H-oleate was in the detergent resistant fraction of an OptiPrep gradient. On OptiPrep gradients of intestinal cytosol, we also found the (3)H-oleate in the detergent resistant fraction, separate from OptiPrep gradients spiked with (3)H-oleate or (3)H-triacylglycerol. Caveolin-1 immuno-depletion of cytosol removed 91% of absorbed (3)H-oleate whereas immuno-depletion using IgG, or anti-caveolin-2 or -3 or anti-clathrin antibodies removed 20%. Electron microscopy showed the presence of caveolin-1 containing vesicles in WT mouse cytosol that were 4 fold increased by feeding intestinal sacs 1mM oleate. No vesicles were seen in caveolin-1 KO mouse cytosol. Caveolin-1 KO mice gained less weight on a 23% fat diet and had increased fat in their stool compared to WT mice. We conclude that dietary fatty acids are absorbed by caveolae in enterocyte brush border membranes, are endocytosed, and transported in cytosol in caveolin-1 containing endocytic vesicles.
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Affiliation(s)
- Shahzad Siddiqi
- Division of Gastroenterology, Department of Medicine, The University of Tennessee Health Science Center 38163
| | - Atur Sheth
- Division of Gastroenterology, Department of Medicine, The University of Tennessee Health Science Center 38163
| | - Feenalie Patel
- Division of Gastroenterology, Department of Medicine, The University of Tennessee Health Science Center 38163
| | - Matthew Barnes
- Division of Gastroenterology, Department of Medicine, The University of Tennessee Health Science Center 38163
| | - Charles M. Mansbach
- Division of Gastroenterology, Department of Medicine, The University of Tennessee Health Science Center 38163
- Veterans Affairs Medical Center, Memphis, TN 38104
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Venkatachalam AB, Sawler DL, Wright JM. Tissue-specific transcriptional modulation of fatty acid-binding protein genes, fabp2, fabp3 and fabp6, by fatty acids and the peroxisome proliferator, clofibrate, in zebrafish (Danio rerio). Gene 2013; 520:14-21. [PMID: 23466978 DOI: 10.1016/j.gene.2013.02.034] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Revised: 02/19/2013] [Accepted: 02/21/2013] [Indexed: 12/28/2022]
Abstract
All fabp genes, except fabp2, fabp3 and fabp6, exist as duplicates in the zebrafish genome owing to a whole genome duplication event ~230-400 million years ago. Transcription of some duplicated fabp genes is modulated by fatty acids (FAs) and/or clofibrate, a peroxisome proliferator-activated receptor (PPAR) agonist. We had also shown previously that the steady-state level of acyl-CoA oxidase 1 (acox1) mRNA, a marker of PPARα activation, was elevated in liver, intestine, heart and muscle of fish fed clofibrate demonstrating that zebrafish, unlike some fishes, is responsive to this drug. acox1 transcripts were not induced in the brain of fish fed clofibrate, which suggests this drug may not cross the blood brain barrier. Here, we investigated the effect of dietary FAs and clofibrate on the transcription of single copy fabp genes, fabp2, fabp3 and fabp6, in five tissues of inbred zebrafish. The steady-state level of fabp2 transcripts increased in intestine, while fabp3 mRNA increased in liver of fish fed diets differing in FA content. In fish fed clofibrate, fabp3 mRNA in intestine, and fabp6 mRNA in intestine and heart, were elevated. Based on these findings, modulation of fabp2, fabp3 and fabp6 transcription by FAs and/or clofibrate in zebrafish implicates control of these genes by PPAR interaction with peroxisome proliferator response elements (PPRE) most likely in fabp promoters. Moreover, transcriptional induction of these fabp genes by dietary FAs and/or clofibrate is over-ridden by a tissue-specific mechanism(s), e.g., transcriptional activator or repressor proteins.
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Venkatachalam AB, Lall SP, Denovan-Wright EM, Wright JM. Tissue-specific differential induction of duplicated fatty acid-binding protein genes by the peroxisome proliferator, clofibrate, in zebrafish (Danio rerio). BMC Evol Biol 2012; 12:112. [PMID: 22776158 PMCID: PMC3483278 DOI: 10.1186/1471-2148-12-112] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2012] [Accepted: 05/31/2012] [Indexed: 01/03/2023] Open
Abstract
Background Force, Lynch and Conery proposed the duplication-degeneration-complementation (DDC) model in which partitioning of ancestral functions (subfunctionalization) and acquisition of novel functions (neofunctionalization) were the two primary mechanisms for the retention of duplicated genes. The DDC model was tested by analyzing the transcriptional induction of the duplicated fatty acid-binding protein (fabp) genes by clofibrate in zebrafish. Clofibrate is a specific ligand of the peroxisome proliferator-activated receptor (PPAR); it activates PPAR which then binds to a peroxisome proliferator response element (PPRE) to induce the transcriptional initiation of genes primarily involved in lipid homeostasis. Zebrafish was chosen as our model organism as it has many duplicated genes owing to a whole genome duplication (WGD) event that occurred ~230-400 million years ago in the teleost fish lineage. We assayed the steady-state levels of fabp mRNA and heterogeneous nuclear RNA (hnRNA) transcripts in liver, intestine, muscle, brain and heart for four sets of duplicated fabp genes, fabp1a/fabp1b.1/fabp1b.2, fabp7a/fabp7b, fabp10a/fabp10b and fabp11a/fabp11b in zebrafish fed different concentrations of clofibrate. Result Electron microscopy showed an increase in the number of peroxisomes and mitochondria in liver and heart, respectively, in zebrafish fed clofibrate. Clofibrate also increased the steady-state level of acox1 mRNA and hnRNA transcripts in different tissues, a gene with a functional PPRE. These results demonstrate that zebrafish is responsive to clofibrate, unlike some other fishes. The levels of fabp mRNA and hnRNA transcripts for the four sets of duplicated fabp genes was determined by reverse transcription, quantitative polymerase chain reaction (RT-qPCR). The level of hnRNA coded by a gene is an indirect estimate of the rate of transcriptional initiation of that gene. Clofibrate increased the steady-state level of fabp mRNAs and hnRNAs for both the duplicated copies of fabp1a/fabp1b.1, and fabp7a/fabp7b, but in different tissues. Clofibrate also increased the steady-state level of fabp10a and fabp11a mRNAs and hnRNAs in liver, but not for fabp10b and fabp11b. Conclusion Some duplicated fabp genes have, most likely, retained PPREs, but induction by clofibrate is over-ridden by an, as yet, unknown tissue-specific mechanism(s). Regardless of the tissue-specific mechanism(s), transcriptional control of duplicated zebrafish fabp genes by clofibrate has markedly diverged since the WGD event.
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12
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Siddiqi S, Mansbach CM. Phosphorylation of Sar1b protein releases liver fatty acid-binding protein from multiprotein complex in intestinal cytosol enabling it to bind to endoplasmic reticulum (ER) and bud the pre-chylomicron transport vesicle. J Biol Chem 2012; 287:10178-10188. [PMID: 22303004 DOI: 10.1074/jbc.m111.327247] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Native cytosol requires ATP to initiate the budding of the pre-chylomicron transport vesicle from intestinal endoplasmic reticulum (ER). When FABP1 alone is used, no ATP is needed. Here, we test the hypothesis that in native cytosol FABP1 is present in a multiprotein complex that prevents FABP1 binding to the ER unless the complex is phosphorylated. We found on chromatography of native intestinal cytosol over a Sephacryl S-100 HR column that FABP1 (14 kDa) eluted in a volume suggesting a 75-kDa protein complex that contained four proteins on an anti-FABP1 antibody pulldown. The FABP1-containing column fractions were chromatographed over an anti-FABP1 antibody adsorption column. Proteins co-eluted from the column were identified as FABP1, Sar1b, Sec13, and small VCP/p97-interactive protein by immunoblot, LC-MS/MS, and MALDI-TOF. The four proteins of the complex had a total mass of 77 kDa and migrated on native PAGE at 75 kDa. When the complex was incubated with intestinal ER, there was no increase in FABP1-ER binding. However, when the complex member Sar1b was phosphorylated by PKCζ and ATP, the complex completely disassembled into its component proteins that migrated at their monomer molecular weight on native PAGE. FABP1, freed from the complex, was now able to bind to intestinal ER and generate the pre-chylomicron transport vesicle (PCTV). No increase in ER binding or PCTV generation was observed in the absence of PKCζ or ATP. We conclude that phosphorylation of Sar1b disrupts the FABP1-containing four-membered 75-kDa protein complex in cytosol enabling it to bind to the ER and generate PCTV.
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Affiliation(s)
- Shahzad Siddiqi
- Department of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee 38163 and
| | - Charles M Mansbach
- Department of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee 38163 and; Veterans Affairs Medical Center, Memphis, Tennessee 38104.
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13
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Atshaves B, Martin G, Hostetler H, McIntosh A, Kier A, Schroeder F. Liver fatty acid-binding protein and obesity. J Nutr Biochem 2010; 21:1015-32. [PMID: 20537520 PMCID: PMC2939181 DOI: 10.1016/j.jnutbio.2010.01.005] [Citation(s) in RCA: 159] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2009] [Revised: 01/11/2010] [Accepted: 01/12/2010] [Indexed: 12/17/2022]
Abstract
While low levels of unesterified long chain fatty acids (LCFAs) are normal metabolic intermediates of dietary and endogenous fat, LCFAs are also potent regulators of key receptors/enzymes and at high levels become toxic detergents within the cell. Elevated levels of LCFAs are associated with diabetes, obesity and metabolic syndrome. Consequently, mammals evolved fatty acid-binding proteins (FABPs) that bind/sequester these potentially toxic free fatty acids in the cytosol and present them for rapid removal in oxidative (mitochondria, peroxisomes) or storage (endoplasmic reticulum, lipid droplets) organelles. Mammals have a large (15-member) family of FABPs with multiple members occurring within a single cell type. The first described FABP, liver-FABP (L-FABP or FABP1), is expressed in very high levels (2-5% of cytosolic protein) in liver as well as in intestine and kidney. Since L-FABP facilitates uptake and metabolism of LCFAs in vitro and in cultured cells, it was expected that abnormal function or loss of L-FABP would reduce hepatic LCFA uptake/oxidation and thereby increase LCFAs available for oxidation in muscle and/or storage in adipose. This prediction was confirmed in vitro with isolated liver slices and cultured primary hepatocytes from L-FABP gene-ablated mice. Despite unaltered food consumption when fed a control diet ad libitum, the L-FABP null mice exhibited age- and sex-dependent weight gain and increased fat tissue mass. The obese phenotype was exacerbated in L-FABP null mice pair fed a high-fat diet. Taken together with other findings, these data suggest that L-FABP could have an important role in preventing age- or diet-induced obesity.
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Affiliation(s)
- B.P. Atshaves
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX 77843-4466
| | - G.G. Martin
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX 77843-4466
| | - H.A. Hostetler
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX 77843-4466
| | - A.L. McIntosh
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX 77843-4466
| | - A.B. Kier
- Department of Pathobiology, Texas A&M University, TVMC, College Station, TX 77843-4467
| | - F. Schroeder
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX 77843-4466
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Abstract
The absorption of dietary fat is of increasing concern given the rise of obesity not only in the United States but throughout the developed world. This review explores what happens to dietary fat within the enterocyte. Absorbed fatty acids and monoacylglycerols are required to be bound to intracellular proteins and/or to be rapidly converted to triacylglycerols to prevent cellular membrane disruption. The triacylglycerol produced at the level of the endoplasmic reticulum (ER) is either incorporated into prechylomicrons within the ER lumen or shunted to triacylglycerol storage pools. The prechylomicrons exit the ER in a specialized transport vesicle in the rate-limiting step in the intracellular transit of triacylglycerol across the enterocyte. The prechylomicrons are further processed in the Golgi and are transported to the basolateral membrane via a separate vesicular system for exocytosis into the intestinal lamina propria. Fatty acids and monoacylglycerols entering the enterocyte via the basolateral membrane are also incorporated into triacylglycerol, but the basolaterally entering lipid is much more likely to enter the triacylglycerol storage pool than the lipid entering via the apical membrane.
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Affiliation(s)
- Charles M Mansbach
- The University of Tennessee Health Science Center and the Veterans Administration Medical Center, Memphis, TN 38163, USA.
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15
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Siddiqi S, Saleem U, Abumrad NA, Davidson NO, Storch J, Siddiqi SA, Mansbach CM. A novel multiprotein complex is required to generate the prechylomicron transport vesicle from intestinal ER. J Lipid Res 2010; 51:1918-28. [PMID: 20237389 DOI: 10.1194/jlr.m005611] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Dietary lipid absorption is dependent on chylomicron production whose rate-limiting step across the intestinal absorptive cell is the exit of chylomicrons from the endoplasmic reticulum (ER) in its ER-to-Golgi transport vesicle, the prechylomicron transport vesicle (PCTV). This study addresses the composition of the budding complex for PCTV. Immunoprecipitation (IP) studies from rat intestinal ER solubilized in Triton X-100 suggested that vesicle-associated membrane protein 7 (VAMP7), apolipoprotein B48 (apoB48), liver fatty acid-binding protein (L-FABP), CD36, and the COPII proteins were associated on incubation of the ER with cytosol and ATP. This association was confirmed by chromatography of the solubilized ER over Sephacryl S400-HR in which these constituents cochromatographed with an apparent kDa of 630. No multiprotein complex was detected when the ER was chromatographed in the absence of PCTV budding activity (resting ER or PKCzeta depletion of ER and cytosol). Treatment of the ER with anti-apoB48 or anti-VAMP7 antibodies or using gene disrupted L-FABP or CD36 mice all significantly inhibited PCTV generation. A smaller complex (no COPII proteins) was formed when only rL-FABP was used to bud PCTV. The data support the conclusion that the PCTV budding complex in intestinal ER is composed of VAMP7, apoB48, CD36, and L-FABP, plus the COPII proteins.
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Affiliation(s)
- Shahzad Siddiqi
- Division of Gastroenterology, Department of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
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16
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Characterization of critical factors influencing gene expression of two types of fatty acid-binding proteins (L-FABP and Lb-FABP) in the liver of birds. Comp Biochem Physiol A Mol Integr Physiol 2009; 154:216-23. [DOI: 10.1016/j.cbpa.2009.06.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2009] [Revised: 06/10/2009] [Accepted: 06/11/2009] [Indexed: 11/18/2022]
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17
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Karanth S, Lall SP, Denovan-Wright EM, Wright JM. Differential transcriptional modulation of duplicated fatty acid-binding protein genes by dietary fatty acids in zebrafish (Danio rerio): evidence for subfunctionalization or neofunctionalization of duplicated genes. BMC Evol Biol 2009; 9:219. [PMID: 19725974 PMCID: PMC2754478 DOI: 10.1186/1471-2148-9-219] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2009] [Accepted: 09/02/2009] [Indexed: 12/25/2022] Open
Abstract
Background In the Duplication-Degeneration-Complementation (DDC) model, subfunctionalization and neofunctionalization have been proposed as important processes driving the retention of duplicated genes in the genome. These processes are thought to occur by gain or loss of regulatory elements in the promoters of duplicated genes. We tested the DDC model by determining the transcriptional induction of fatty acid-binding proteins (Fabps) genes by dietary fatty acids (FAs) in zebrafish. We chose zebrafish for this study for two reasons: extensive bioinformatics resources are available for zebrafish at zfin.org and zebrafish contains many duplicated genes owing to a whole genome duplication event that occurred early in the ray-finned fish lineage approximately 230-400 million years ago. Adult zebrafish were fed diets containing either fish oil (12% lipid, rich in highly unsaturated fatty acid), sunflower oil (12% lipid, rich in linoleic acid), linseed oil (12% lipid, rich in linolenic acid), or low fat (4% lipid, low fat diet) for 10 weeks. FA profiles and the steady-state levels of fabp mRNA and heterogeneous nuclear RNA in intestine, liver, muscle and brain of zebrafish were determined. Result FA profiles assayed by gas chromatography differed in the intestine, brain, muscle and liver depending on diet. The steady-state level of mRNA for three sets of duplicated genes, fabp1a/fabp1b.1/fabp1b.2, fabp7a/fabp7b, and fabp11a/fabp11b, was determined by reverse transcription, quantitative polymerase chain reaction (RT-qPCR). In brain, the steady-state level of fabp7b mRNAs was induced in fish fed the linoleic acid-rich diet; in intestine, the transcript level of fabp1b.1 and fabp7b were elevated in fish fed the linolenic acid-rich diet; in liver, the level of fabp7a mRNAs was elevated in fish fed the low fat diet; and in muscle, the level of fabp7a and fabp11a mRNAs were elevated in fish fed the linolenic acid-rich or the low fat diets. In all cases, induction of the steady-state level of fabp mRNAs by dietary FAs correlated with induced levels of hnRNA for a given fabp gene. As such, up-regulation of the steady-state level of fabp mRNAs by FAs occurred at the level of initiation of transcription. None of the sister duplicates of these fabp genes exhibited an increase in their steady-state transcript levels in a specific tissue following feeding zebrafish any of the four experimental diets. Conclusion Differential induction of only one of the sister pair of duplicated fabp genes by FAs provides evidence to support the DDC model for retention of duplicated genes in the zebrafish genome by either subfunctionalization or neofunctionalization.
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Affiliation(s)
- Santhosh Karanth
- Department of Biology, Dalhousie University, Halifax, Nova Scotia, B3H 4J1, Canada.
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18
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Yan J, Gong Y, She YM, Wang G, Roberts MS, Burczynski FJ. Molecular mechanism of recombinant liver fatty acid binding protein's antioxidant activity. J Lipid Res 2009; 50:2445-54. [PMID: 19474456 DOI: 10.1194/jlr.m900177-jlr200] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Hepatocytes expressing liver fatty acid binding protein (L-FABP) are known to be more resistant to oxidative stress than those devoid of this protein. The mechanism for the observed antioxidant activity is not known. We examined the antioxidant mechanism of a recombinant rat L-FABP in the presence of a hydrophilic (AAPH) or lipophilic (AMVN) free radical generator. Recombinant L-FABP amino acid sequence and its amino acid oxidative products following oxidation were identified by MALDI quadrupole time-of-flight MS after being digested by endoproteinase Glu-C. L-FABP was observed to have better antioxidative activity when free radicals were generated by the hydrophilic generator than by the lipophilic generator. Oxidative modification of L-FABP included up to five methionine oxidative peptide products with a total of approximately 80 Da mass shift compared with native L-FABP. Protection against lipid peroxidation of L-FABP after binding with palmitate or alpha-bromo-palmitate by the AAPH or AMVN free radical generators indicated that ligand binding can partially block antioxidant activity. We conclude that the mechanism of L-FABP's antioxidant activity is through inactivation of the free radicals by L-FABP's methionine and cysteine amino acids. Moreover, exposure of the L-FABP binding site further promotes its antioxidant activity. In this manner, L-FABP serves as a hepatocellular antioxidant.
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Affiliation(s)
- Jing Yan
- Faculty of Pharmacy, University of Manitoba, Winnipeg, Canada
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19
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O'Sullivan AJ. Does oestrogen allow women to store fat more efficiently? A biological advantage for fertility and gestation. Obes Rev 2009; 10:168-77. [PMID: 19021869 DOI: 10.1111/j.1467-789x.2008.00539.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
In normal healthy-weight humans, women have a higher percentage body fat than men, a difference that commences at puberty and continues throughout adult life, suggesting that the mechanism is related to sex steroids. The first half of pregnancy is also a stage of body fat gain in women. From an energy balance point, there is no explanation why women should be fatter than men, as the latter consume more calories proportionately. Moreover, women store fat in early pregnancy when caloric intake does not significantly change. The aim of this review is to focus on evidence supporting one mechanism that may account for these findings. That is, oestrogen reduces postprandial fatty acid oxidation leading to an increase in body fat which may account for the greater fat mass observed in women compared with men and the fat gain in early pregnancy. Therefore, female puberty and early pregnancy could be seen as states of efficient fat storage of energy in preparation for fertility, foetal development and lactation providing an obvious biological advantage. Further research into this mechanism of fat storage may provide further insights into the regulation of body fat.
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Affiliation(s)
- A J O'Sullivan
- Department of Medicine, St George Hospital, University of New South Wales, Sydney, Australia.
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20
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Levin LBA, Nachliel E, Gutman M, Tsfadia Y. Molecular dynamics study of the interaction between fatty acid binding proteins with palmitate mini-micelles. Mol Cell Biochem 2009; 326:29-33. [DOI: 10.1007/s11010-008-0010-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2007] [Accepted: 06/10/2008] [Indexed: 11/29/2022]
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21
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Siddiqi SA, Mansbach CM. PKC zeta-mediated phosphorylation controls budding of the pre-chylomicron transport vesicle. J Cell Sci 2008; 121:2327-38. [PMID: 18577579 DOI: 10.1242/jcs.022780] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Dietary triacylglycerols are absorbed by enterocytes and packaged in the endoplasmic reticulum (ER) in the intestinal specific lipoprotein, the chylomicron, for export into mesenteric lymph. Chylomicrons exit the ER in an ER-to-Golgi transport vesicle, the pre-chylomicron transport vesicle (PCTV), which is the rate-limiting step in the transit of chylomicrons across the cell. Here, we focus on potential mechanisms of control of the PCTV-budding step from the intestinal ER. We incubated intestinal ER with intestinal cytosol and ATP to cause PCTV budding. The budding reaction was inhibited by 60 nM of the PKC inhibitor Gö 6983, suggesting the importance of PKCzeta in the generation of PCTV. Immunodepletion of PKCzeta from the cytosol and the use of washed ER greatly inhibited the generation of PCTVs, but was restored following the addition of recombinant PKCzeta. Intestinal ER incubated with intestinal cytosol and [gamma-(32)P]ATP under conditions supporting the generation of PCTVs showed the phosphorylation of a 9-kDa band following autoradiography. The phosphorylation of this protein correlated with the generation of PCTVs but not the formation of protein vesicles and was inhibited by depletion of PKCzeta. Phosphorylation of the 9-kDa protein was restored following the addition of recombinant PKCzeta. The association of the 9-kDa protein with proteins that are important for PCTV budding was phosphorylation dependent. We conclude that PKCzeta activity is required for PCTV budding from intestinal ER, and is associated with phosphorylation of a 9-kDa protein that might regulate PCTV budding.
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Affiliation(s)
- Shadab A Siddiqi
- The Division of Gastroenterology, The University of Tennessee Health Science Center, Memphis, TN 38163, USA
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22
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Montoudis A, Seidman E, Boudreau F, Beaulieu JF, Menard D, Elchebly M, Mailhot G, Sane AT, Lambert M, Delvin E, Levy E. Intestinal fatty acid binding protein regulates mitochondrion beta-oxidation and cholesterol uptake. J Lipid Res 2008; 49:961-72. [PMID: 18235139 DOI: 10.1194/jlr.m700363-jlr200] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The role of intestinal fatty acid binding protein (I-FABP) in lipid metabolism remains elusive. To address this issue, normal human intestinal epithelial cells (HIEC-6) were transfected with cDNA to overexpress I-FABP and compared with cells treated with empty pQCXIP vector. I-FABP overexpression stimulated mitochondrial [U-14C]oleate oxidation to CO2 and acid-soluble metabolites via mechanisms including the upregulation of protein expression and the activity of carnitine palmitoyltransferase 1, a critical enzyme controlling the entry of fatty acid (FA) into mitochondria, and increased activity of 3-hydroxyacyl-CoA dehydrogenase, a mitochondrial beta-oxidation enzyme. On the other hand, the gene and protein expression of the key enzymes FA synthase and acetyl-coenzyme A carboxylase 2 was decreased, suggesting diminished lipogenesis. Furthermore, I-FABP overexpression caused a decline in [14C]free cholesterol (CHOL) incorporation. Accordingly, a significant lessening was observed in the gene expression of Niemann Pick C1-Like 1, a mediator of CHOL uptake, along with an increase in the transcripts and protein content of ABCA1 and ABCG5/ABCG8, acting as CHOL efflux pumps. Furthermore, I-FABP overexpression resulted in increased levels of mRNA, protein mass, and activity of HMG-CoA reductase, the rate-limiting step in CHOL synthesis. Scrutiny of the nuclear receptors revealed augmented peroxisome proliferator-activated receptor alpha,gamma and reduced liver X receptor-alpha in HIEC-6 overexpressing I-FABP. Finally, I-FABP overexpression did not influence acyl-coenzyme A oxidase 1, which catalyzes the first rate-limiting step in peroxisomal FA beta-oxidation. Overall, our data suggest that I-FABP may influence mitochondrial FA oxidation and CHOL transport by regulating gene expression and interaction with nuclear receptors.
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Affiliation(s)
- Alain Montoudis
- Department of Nutrition, Centre Hospitalier Universitaire Sainte-Justine, Université de Montréal, Montreal, Quebec, Canada
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23
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Alvite G, Canclini L, Corvo I, Esteves A. Two novel Mesocestoides vogae fatty acid binding proteins - functional and evolutionary implications. FEBS J 2007; 275:107-16. [DOI: 10.1111/j.1742-4658.2007.06179.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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24
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Agellon LB, Drozdowski L, Li L, Iordache C, Luong L, Clandinin MT, Uwiera RRE, Toth MJ, Thomson ABR. Loss of intestinal fatty acid binding protein increases the susceptibility of male mice to high fat diet-induced fatty liver. Biochim Biophys Acta Mol Cell Biol Lipids 2007; 1771:1283-8. [PMID: 17905650 DOI: 10.1016/j.bbalip.2007.08.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2007] [Revised: 08/07/2007] [Accepted: 08/08/2007] [Indexed: 01/20/2023]
Abstract
Mice lacking I-FABP (encoded by the Fabp2 gene) exhibit a gender dimorphic response to a high fat/cholesterol diet challenge characterized by hepatomegaly in male I-FABP-deficient mice. In this study, we determined if this gender-specific modification of liver mass in mice lacking I-FABP is attributable to the high fat content of the diet alone and whether hepatic Fabp1 gene (encodes L-FABP) expression contributes to this difference. Wild-type and Fabp2-/- mice of both genders were fed a diet enriched with either polyunsaturated or saturated fatty acids (PUFA or SFA, respectively) in the absence of cholesterol. Male Fabp2-/- mice, but not female Fabp2-/- mice, exhibited increased liver mass and hepatic triacylglycerol (TG) deposition as compared to corresponding wild-type mice. In wild-type mice that were fed the standard chow diet, there was no difference in the concentration of hepatic L-FABP protein between males and females although the loss of I-FABP did cause a slight reduction of hepatic L-FABP abundance in both genders. The hepatic L-FABP mRNA abundance in both male and female wild-type and Fabp2-/- mice was higher in the PUFA-fed group than in the SFA-fed group, and was correlated with L-FABP protein abundance. No correlation between hepatic L-FABP protein abundance and hepatic TG concentration was found. The results obtained demonstrate that loss of I-FABP renders male mice sensitive to high fat diet-induced fatty liver, and this effect is independent of hepatic L-FABP.
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Affiliation(s)
- Luis B Agellon
- Canadian Institutes of Health Research Molecular and Cell Biology of Lipids Research Group and Department of Biochemistry, University of Alberta, Edmonton, AB, Canada T6G 2S2.
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25
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Guilmeau S, Niot I, Laigneau JP, Devaud H, Petit V, Brousse N, Bouvier R, Ferkdadji L, Besmond C, Aggerbeck LP, Bado A, Samson-Bouma ME. Decreased expression of Intestinal I- and L-FABP levels in rare human genetic lipid malabsorption syndromes. Histochem Cell Biol 2007; 128:115-23. [PMID: 17605029 DOI: 10.1007/s00418-007-0302-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/31/2007] [Indexed: 11/26/2022]
Abstract
We investigated, for the first time, the expression of I- and L-FABP in two very rare hereditary lipid malabsorption syndromes as compared with normal subjects. Abetalipoproteinemia (ABL) and Anderson's disease (AD) are characterized by an inability to export alimentary lipids as chylomicrons that result in fat loading of enterocytes. Duodeno-jejunal biopsies were obtained from 14 fasted normal subjects, and from four patients with ABL and from six with AD. Intestinal FABP expression was investigated by immuno-histochemistry, western blot, ELISA and Northern blot analysis. In contrast to normal subjects, the cellular immunostaining for both FABPs was clearly decreased in patients, as the enterocytes became fat-laden. In patients with ABL, the intestinal contents of I- (60.7 +/- 13.38 ng/mg protein) and L-FABP (750.3 +/- 121.3 ng/mg protein) are significantly reduced (50 and 35%, P < 0.05, respectively) as compared to normal subjects (I-135.3 +/- 11.1 ng, L-1211 +/- 110 ng/mg protein). In AD, the patients also exhibited decreased expression (50%, P < 0.05; I-59 +/- 11.88 ng, L-618.2 +/- 104.6 ng/mg protein). Decreased FABP expression was not associated with decreased mRNA levels. The results suggest that enterocytes might regulate intracellular FABP content in response to intracellular fatty acids, which we speculate may act as lipid sensors to prevent their intracellular transport.
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Affiliation(s)
- S Guilmeau
- Institut National de la Santé et de la Recherche Médicale (INSERM), U773, Centre de Recherche Bichat Beaujon CRB3, Université Paris 7 Denis Diderot, site Bichat, BP 416, 75018, Paris, France
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26
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Belaguli NS, Zhang M, Rigi M, Aftab M, Berger DH. Cooperation between GATA4 and TGF-beta signaling regulates intestinal epithelial gene expression. Am J Physiol Gastrointest Liver Physiol 2007; 292:G1520-33. [PMID: 17290010 DOI: 10.1152/ajpgi.00236.2006] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Members of the transforming growth factor-beta (TGF-beta) family have been shown to play an important role in the regulation of gut epithelial gene expression. We have used the intestinal alkaline phosphatase (IAP) and intestinal fatty acid binding protein (IFABP) promoters to dissect the mechanisms by which TGF-beta1 signaling regulates gut epithelial gene expression. TGF-beta signaling alone was not sufficient for activation of IAP and IFABP promoters. However, TGF-beta signaling cooperated with the gut epithelial transcription factor GATA4 to synergistically activate IAP and IFABP promoters. Coexpression of GATA4 along with the TGF-beta1 signal transducing downstream effectors such as Smad2, 3, and 4 resulted in synergistic activation of both IAP and IFABP promoters. This synergistic activation was reduced by simultaneous expression of dominant-negative Smad4. -40 and -89 GATA binding sites in the IFABP promoter were required for the synergistic activation by Smad2, 3, and 4 and GATA4. GATA4 and Smad2, 3, and 4 physically associated with each other and this interaction was mediated through the MH2 domain of Smad2, 3, and 4 and the second zinc finger and the COOH-terminal basic domain of GATA4. The COOH-terminal activation domain and the Smad-interacting second zinc finger domain of GATA4 were required for the synergistic activation of the IFABP promoter. Naturally occurring oncogenic mutations within the GATA4-interacting MH2 domain of Smad2 reduced the coactivation of IFABP promoter by Smad2 and GATA4. Our results suggest that the TGF-beta signaling regulates gut epithelial gene expression by targeting GATA4.
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MESH Headings
- Activin Receptors, Type I/metabolism
- Alkaline Phosphatase
- Animals
- Antigens, Neoplasm/genetics
- Antigens, Neoplasm/metabolism
- Epithelial Cells/metabolism
- Epithelial Cells/pathology
- Fatty Acid-Binding Proteins/genetics
- Fatty Acid-Binding Proteins/metabolism
- GATA4 Transcription Factor/chemistry
- GATA4 Transcription Factor/genetics
- GATA4 Transcription Factor/metabolism
- GPI-Linked Proteins
- Gene Expression
- Genes, Reporter
- HCT116 Cells
- Haplorhini
- Humans
- Intestinal Mucosa/metabolism
- Intestinal Mucosa/pathology
- Luciferases
- Mutation
- Promoter Regions, Genetic
- Protein Binding
- Protein Serine-Threonine Kinases
- Protein Structure, Tertiary
- RNA Interference
- RNA, Small Interfering/genetics
- RNA, Small Interfering/metabolism
- Receptor, Transforming Growth Factor-beta Type I
- Receptors, Transforming Growth Factor beta/metabolism
- Signal Transduction/genetics
- Smad2 Protein/metabolism
- Smad3 Protein/metabolism
- Smad4 Protein/metabolism
- Transfection
- Transforming Growth Factor beta1/genetics
- Transforming Growth Factor beta1/metabolism
- Zinc Fingers
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Affiliation(s)
- Narasimhaswamy S Belaguli
- Michael E. DeBakey Dept. of Surgery, Michael E. DeBakey VA Medical Center, Baylor College of Medicine, 2002 Holcombe Blvd., Houston, Texas 77030, USA.
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Neeli I, Siddiqi SA, Siddiqi S, Mahan J, Lagakos WS, Binas B, Gheyi T, Storch J, Mansbach CM. Liver fatty acid-binding protein initiates budding of pre-chylomicron transport vesicles from intestinal endoplasmic reticulum. J Biol Chem 2007; 282:17974-17984. [PMID: 17449472 DOI: 10.1074/jbc.m610765200] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The rate-limiting step in the transit of absorbed dietary fat across the enterocyte is the generation of the pre-chylomicron transport vesicle (PCTV) from the endoplasmic reticulum (ER). This vesicle does not require coatomer-II (COPII) proteins for budding from the ER membrane and contains vesicle-associated membrane protein 7, found in intestinal ER, which is a unique intracellular location for this SNARE protein. We wished to identify the protein(s) responsible for budding this vesicle from ER membranes in the absence of the requirement for COPII proteins. We chromatographed rat intestinal cytosol on Sephacryl S-100 and found that PCTV budding activity appeared in the low molecular weight fractions. Additional chromatographic steps produced a single major and several minor bands on SDS-PAGE. By tandem mass spectroscopy, the bands contained both liver and intestinal fatty acid-binding proteins (L- and I-FABP) as well as four other proteins. Recombinant proteins for each of the six proteins identified were tested for PCTV budding activity; only L-FABP and I-FABP (23% the activity of L-FABP) were active. The vesicles generated by L-FABP were sealed, contained apolipoproteins B48 and AIV, were of the same size as PCTV on Sepharose CL-6B, and by electron microscopy, excluded calnexin and calreticulin but did not fuse with cis-Golgi nor did L-FABP generate COPII-dependent vesicles. Gene-disrupted L-FABP mouse cytosol had 60% the activity of wild type mouse cytosol. We conclude that L-FABP can select cargo for and bud PCTV from intestinal ER membranes.
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Affiliation(s)
- Indira Neeli
- Department of Molecular Sciences, University of Tennessee Health Science Center, Memphis, Tennessee 38163
| | - Shadab A Siddiqi
- Division of Gastroenterology, University of Tennessee Health Science Center, Memphis, Tennessee 38163
| | - Shahzad Siddiqi
- Division of Gastroenterology, University of Tennessee Health Science Center, Memphis, Tennessee 38163
| | - James Mahan
- Veterans Affairs Medical Center, Memphis, Tennessee 38104
| | - William S Lagakos
- Department of Nutritional Sciences, Rutgers University, New Brunswick, New Jersey 08901
| | - Bert Binas
- Department of Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas 77843
| | - Tarun Gheyi
- Department of Chemistry, University of Memphis, Memphis, Tennessee 38152
| | - Judith Storch
- Department of Nutritional Sciences, Rutgers University, New Brunswick, New Jersey 08901.
| | - Charles M Mansbach
- Division of Gastroenterology, University of Tennessee Health Science Center, Memphis, Tennessee 38163; Veterans Affairs Medical Center, Memphis, Tennessee 38104.
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28
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Bordewick U, Schulenberg H, Schäfer P, Spener F. Recognition of Fatty Acids by Hepatic Fatty Acid Binding Proteins. ACTA ACUST UNITED AC 2006. [DOI: 10.1002/lipi.19860881411] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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29
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Divine JK, Staloch LJ, Haveri H, Rowley CW, Heikinheimo M, Simon TC. Cooperative interactions among intestinal GATA factors in activating the rat liver fatty acid binding protein gene. Am J Physiol Gastrointest Liver Physiol 2006; 291:G297-306. [PMID: 16603485 DOI: 10.1152/ajpgi.00422.2003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
GATA-4, GATA-5, and GATA-6 are endodermal zinc-finger transcription factors that activate numerous enterocytic genes. GATA-4 and GATA-6 but not GATA-5 are present in adult murine small intestinal enterocytes, and we now report the simultaneous presence of all three GATA factors in murine small intestinal enterocytes before weaning age. An immunohistochemical survey detected enterocytic GATA-4 and GATA-6 at birth and 1 wk of age and GATA-5 at 1 wk but not birth. Interactions among GATA factors were explored utilizing a transgene constructed from the proximal promoter of the rat liver fatty acid binding protein gene (Fabp1). GATA-4 and GATA-5 but not GATA-6 activate the Fabp1 transgene through a cognate binding site at -128. A dose-response assay revealed a maximum in transgene activation by both factors, where additional factor did not further increase transgene activity. However, at saturated levels of GATA-4, additional transgene activation was achieved by adding GATA-5 expression construct, and vice versa. Similar cooperativity occurred with GATA-5 and GATA-6. Identical interactions were observed with a target transgene consisting of a single GATA site upstream of a minimal promoter. Furthermore, GATA-4 and GATA-5 or GATA-5 and GATA-6 bound to each other in solution. These results are consistent with tethering of one GATA factor to the Fabp1 promoter through interaction with a second GATA factor to produce increased target gene activation. Cooperative target gene activation was specific to an intestinal cell line and may represent a mechanism by which genes are activated in the small intestinal epithelium during the period before weaning.
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Affiliation(s)
- Joyce K Divine
- Division of Biology, Washington University School of Medicine, St. Louis, MO 63110, USA
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30
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Mazzanti R, Solazzo M, Fantappié O, Elfering S, Pantaleo P, Bechi P, Cianchi F, Ettl A, Giulivi C. Differential expression proteomics of human colon cancer. Am J Physiol Gastrointest Liver Physiol 2006; 290:G1329-38. [PMID: 16439467 DOI: 10.1152/ajpgi.00563.2005] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The focus of this study was to use differential protein expression to investigate operative pathways in early stages of human colon cancer. Colorectal cancer represents an ideal model system to study the development and progression of human tumors, and the proteomic approach avoids overlooking posttranslational modifications not detected by microarray analyses and the limited correlation between transcript and protein levels. Colon cancer samples, confined to the intestinal wall, were analyzed by expression proteomics and compared with matched samples from normal colon tissue. Samples were processed by two-dimensional gel electrophoresis, and spots differentially expressed and consistent across all patients were identified by matrix-assisted laser desorption ionization-time-of-flight mass spectrometry analyses and by Western blot analyses. After differentially expressed proteins and their metabolic pathways were analyzed, the following main conclusions were achieved for tumor tissue: 1) a shift from beta-oxidation, as the main source of energy, to anaerobic glycolysis was observed owed to the alteration of nuclear- versus mitochondrial-encoded proteins and other proteins related to fatty acid and carbohydrate metabolism; 2) lower capacity for Na(+) and K(+) cycling; and 3) operativity of the apoptosis pathway, especially the mitochondrial one. This study of the human colon cancer proteome represents a step toward a better understanding of the metabolomics of colon cancer at early stages confined to the intestinal wall.
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31
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Rowley CW, Staloch LJ, Divine JK, McCaul SP, Simon TC. Mechanisms of mutual functional interactions between HNF-4alpha and HNF-1alpha revealed by mutations that cause maturity onset diabetes of the young. Am J Physiol Gastrointest Liver Physiol 2006; 290:G466-75. [PMID: 16223942 DOI: 10.1152/ajpgi.00431.2005] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Hepatic nuclear factor (HNF)-4alpha and HNF-1alpha are key endodermal transcriptional regulators that physically and functionally interact. HNF-4alpha and HNF-1alpha cooperatively activate genes with binding sites for both factors, whereas suppressive interactions occur at regulatory sequences with a binding site for only one factor. The liver fatty acid binding protein gene (Fabp1) has binding sites for both factors, and chromatin precipitation assays were utilized to demonstrate that HNF-4alpha increased HNF-1alpha Fabp1 promoter occupancy during cooperative transcriptional activation. The HNF4 P2 promoter contains a HNF-1 but not HNF-4 binding site, and HNF-4alpha suppressed HNF-1alpha HNF4 P2 activation and decreased promoter HNF-1alpha occupancy. The apolipoprotein C III (APOC3) promoter contains a HNF-4 but not HNF-1 binding site, and HNF-1alpha suppressed HNF-4alpha APOC3 activation and decreased HNF-4alpha promoter occupancy. Maturity onset diabetes of the young (MODY) as well as defects in hepatic lipid metabolism result from mutations in either HNF-4alpha or HNF-1alpha. We found that MODY missense mutant R127W HNF-4alpha retained wild-type individual Fabp1 activation and bound to HNF-1alpha better than wild-type HNF-4alpha, yet did not cooperate with HNF-1alpha or increase HNF-1alpha Fabp1 promoter occupancy. The R127W mutant was also defective in both suppressing HNF-1alpha activation of HNF4 P2 and decreasing HNF-1alpha promoter occupancy. The HNF-1alpha R131Q MODY mutant also retained wild-type Fabp1 activation and bound to HNF-4alpha as well as the wild type but was defective in both suppressing HNF-4alpha APOC3 activation and decreasing HNF-4alpha promoter occupancy. These results suggest HNF-1alpha-HNF-4alpha functional interactions are accomplished by regulating factor promoter occupancy and that defective factor-factor interactions may contribute to the MODY phenotype.
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Affiliation(s)
- Christopher W Rowley
- Department of Pediatrics, Washington University School of Medicine, Campus Box 8208, St. Louis, MO 63110, USA
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32
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Staloch LJ, Divine JK, Witten JT, Simon TC. C/EBP and Cdx family factors regulate liver fatty acid binding protein transgene expression in the small intestinal epithelium. ACTA ACUST UNITED AC 2005; 1731:168-78. [PMID: 16321657 DOI: 10.1016/j.bbaexp.2005.08.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2005] [Revised: 08/09/2005] [Accepted: 08/25/2005] [Indexed: 11/23/2022]
Abstract
A transgene constructed from the rat liver fatty acid binding protein gene (Fabp1) promoter is active in all murine small intestinal crypt and villus epithelial cells. Coincident Cdx and C/EBP transcription factor binding sites were identified spanning Fabp1 nucleotides -90 to -78. CDX-1, CDX-2, C/EBPalpha, and C/EBPbeta activated the Fabp1 transgene in CaCo-2 cells, and mutagenizing the -78 site prevented activation by these factors. CDX but not C/EBP factors bound to the site in vitro, although C/EBP factors competed with CDX factors for transgene activation. The -78 site adjoins an HNF-1 site, and CDX and C/EBP family factors cooperated with HNF-1alpha but not HNF-1beta to activate the transgene. Furthermore, CDX-1, CDX-2, C/EBPalpha, and C/EBPbeta bound to HNF-1alpha and HNF-1beta. The transgene with a mutagenized -78 site was silenced in vivo specifically in small intestinal crypt epithelial cells but remained active in villus cells. These results demonstrate functional interactions between HNF-1, C/EBP, and CDX family factors and suggest that these interactions may contribute to differential transcriptional regulation in the small intestinal crypt and villus compartments.
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Affiliation(s)
- Lora J Staloch
- Department of Pediatrics, Washington University School of Medicine, Campus Box 8208, St. Louis, MO 63110, USA
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33
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Woudstra TD, Drozdowski LA, Wild GE, Clandinin MT, Agellon LB, Thomson ABR. The age-related decline in intestinal lipid uptake is associated with a reduced abundance of fatty acid-binding protein. Lipids 2005; 39:603-10. [PMID: 15588016 DOI: 10.1007/s11745-004-1272-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Aging is associated with changes in the absorptive capacity of the small intestine. We tested the hypotheses that (i) aging is associated with a decline in lipid absorption, and that (ii) this decreased lipid absorption is due to a decline in the abundance of mRNA and/or the enterocyte cytosolic intestinal FA-binding protein (I-FABP), the liver FA-binding protein (L-FABP), and the ileal lipid-binding protein (ILBP). In vitro uptake studies were performed on Fischer 344 rats at ages 1, 9, and 24 mon. Northern blotting (L-FABP, ILBP) and immunohistochemistry (I-FABP, ILBP) were performed. Aging was associated with decreased animal weights, but the surface area of the intestine was not significantly altered with age. The rates of ileal uptake of 16:0, 18:0, 18:1, and 18:2 were reduced by greater than 50% with aging when expressed on the basis of mucosal weight. This decline was not associated with reduced expression of mRNA for L-FABP or ILBP but was associated with a 50% decrease in the abundance of I-FABP and a 40% decrease in the abundance of ILBP. Thus, the decrease with aging in the ileal uptake of some FA when rates were expressed on the basis of mucosal weight was associated with a reduced abundance of I-FABP and ILBP.
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Affiliation(s)
- Trudy D Woudstra
- Nutrition and Metabolism Group, Division of Gastroenterology, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
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34
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Woudstra TD, Drozdowski LA, Wild GE, Clandinin MT, Agellon LB, Thomson ABR. An isocaloric PUFA diet enhances lipid uptake and weight gain in aging rats. Lipids 2005; 39:343-54. [PMID: 15357022 DOI: 10.1007/s11745-004-1238-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Aging is associated with a change in the morphology and absorptive capacity of the small intestine. In young rats, feeding a semisynthetic diet containing saturated FA (SFA) increases nutrient uptake, as compared with an isocaloric diet containing polyunsaturated FA (PUFA). We tested the hypotheses that (i) aging is associated with a decline in lipid absorption in the Fischer 344 rat; (ii) this decline can be corrected by manipulating the fat composition of the diet; and (iii) the age- and diet-associated variations in lipid uptake are associated with changes in the ileal lipid-binding protein (ILBP) or the intestinal or liver FA-binding proteins (I- or L-FABP, respectively) in the cytosol of the enterocyte. In rats fed SFA or PUFA, aging was associated with a decline in the in vitro uptake of stearic acid (18:0) when expressed on the basis of intestinal or mucosal weight. In contrast, age had no effect on lipid uptake when expressed on the basis of serosal surface area, whereas lipid uptake increased with age when expressed on the basis of mucosal surface area. The age-associated variations in lipid uptake were not associated with changes in protein abundance and/or expression of ILBP, I-FABP, or L-FABP. In 24-mon-old rats, when uptake of lipids was expressed on the basis of mucosal surface area, feeding PUFA enhanced lipid uptake and body weight gain as compared with rats fed SFA. Future studies must determine whether the enhanced lipid uptake and body weight gain observed in older animals fed PUFA have any therapeutic benefit.
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Affiliation(s)
- Trudy D Woudstra
- Nutrition and Metabolism Group, Division of Gastroenterology, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
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35
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Marín C, Pérez-Jiménez F, Gómez P, Delgado J, Paniagua JA, Lozano A, Cortés B, Jiménez-Gómez Y, Gómez MJ, López-Miranda J. The Ala54Thr polymorphism of the fatty acid–binding protein 2 gene is associated with a change in insulin sensitivity after a change in the type of dietary fat. Am J Clin Nutr 2005. [DOI: 10.1093/ajcn/82.1.196] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Affiliation(s)
- Carmen Marín
- From the Lipids and Atherosclerosis Research Unit, Department of Medicine, Hospital Universitario Reina Sofía, School of Medicine, University of Cordoba, Córdoba, Spain
| | - Francisco Pérez-Jiménez
- From the Lipids and Atherosclerosis Research Unit, Department of Medicine, Hospital Universitario Reina Sofía, School of Medicine, University of Cordoba, Córdoba, Spain
| | - Purificación Gómez
- From the Lipids and Atherosclerosis Research Unit, Department of Medicine, Hospital Universitario Reina Sofía, School of Medicine, University of Cordoba, Córdoba, Spain
| | - Javier Delgado
- From the Lipids and Atherosclerosis Research Unit, Department of Medicine, Hospital Universitario Reina Sofía, School of Medicine, University of Cordoba, Córdoba, Spain
| | - Juan Antonio Paniagua
- From the Lipids and Atherosclerosis Research Unit, Department of Medicine, Hospital Universitario Reina Sofía, School of Medicine, University of Cordoba, Córdoba, Spain
| | - Aquiles Lozano
- From the Lipids and Atherosclerosis Research Unit, Department of Medicine, Hospital Universitario Reina Sofía, School of Medicine, University of Cordoba, Córdoba, Spain
| | - Begoña Cortés
- From the Lipids and Atherosclerosis Research Unit, Department of Medicine, Hospital Universitario Reina Sofía, School of Medicine, University of Cordoba, Córdoba, Spain
| | - Yolanda Jiménez-Gómez
- From the Lipids and Atherosclerosis Research Unit, Department of Medicine, Hospital Universitario Reina Sofía, School of Medicine, University of Cordoba, Córdoba, Spain
| | - María José Gómez
- From the Lipids and Atherosclerosis Research Unit, Department of Medicine, Hospital Universitario Reina Sofía, School of Medicine, University of Cordoba, Córdoba, Spain
| | - José López-Miranda
- From the Lipids and Atherosclerosis Research Unit, Department of Medicine, Hospital Universitario Reina Sofía, School of Medicine, University of Cordoba, Córdoba, Spain
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36
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Her GM, Yeh YH, Wu JL. Functional conserved elements mediate intestinal-type fatty acid binding protein (I-FABP) expression in the gut epithelia of zebrafish larvae. Dev Dyn 2005; 230:734-42. [PMID: 15254907 DOI: 10.1002/dvdy.20081] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Intestinal-type fatty acid binding protein (I-FABP) plays an important role in the intracellular binding and trafficking of long chain fatty acids in the intestine. The aim of this study, therefore, was to elucidate the regulation and spatiotemporal expression of the I-FABP gene during zebrafish larval development. We performed in vivo reporter-gene analysis in zebrafish by using a transient and transgenic approach. Green fluorescent protein-reporter analyses revealed that the proximal 192-bp region of the I-FABP promoter is sufficient to direct intestine-specific expression during zebrafish larval development. Functional dissection of a 41-bp region within this 192-bp promoter revealed that one C/EBP and two GATA-like binding sites, along with a novel 15-bp element within it are required for I-FABP gene expression in vivo. In addition, the six consensus sites (CCACATCAGCATGAA) in the 15-bp element are critical for I-FABP gene regulation in the zebrafish gut epithelia. Comparison analyses of the orthologous 15-bp element from mammalian I-FABP genes suggests that these mammalian elements are functionally equivalent to the zebrafish 15 element. These results provide the first in vivo evidence that these binding sites (C/EBP and GATA) and the novel 15-bp element contribute to intestine-specific gene expression and that they are functionally conserved across vertebrate evolution.
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Affiliation(s)
- Guor Mour Her
- Laboratory of Marine Molecular Biology and Biotechnology, Institute of Zoology, Academia Sinica, Taipei, Taiwan, Republic of China.
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37
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Han X, Hinderliter PM, Snow TA, Jepson GW. Binding of perfluorooctanoic acid to rat liver-form and kidney-form alpha2u-globulins. Drug Chem Toxicol 2005; 27:341-60. [PMID: 15573471 DOI: 10.1081/dct-200039725] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Perfluorooctanoic acid (PFOA) is an organic fluorochemical and is reported to have a long half-life in human blood. Its urinary elimination in rats is markedly sex-dependent, and characterized by significantly longer plasma half-life of PFOA in male rats than in females. It has been postulated that male-specific PFOA binding protein(s) is responsible for the long half-life of PFOA in male rats. In this paper, two male rat specific proteins, liver- and kidney-form alpha2u-globulins (A2U(L) and A2U(K)), were purified from male rat urine and kidney, respectively. The binding of these two nroteins to PFOA was investigated using ligand blotting, electrospray ionization mass spectrometry and fluorescence competitive binding assay. The results revealed that both A2U(L) and A2U(K) were able to bind PFOA in vitro under physiological conditions, and that PFOA and a fluorescent-labeled fatty acid shared the same binding site on both A2U(L) and A2U(K). The binding affinities, however, are relatively weak. The estimated dissociation constants are in the 10(-3) M range, indicating that bindings of PFOA to either A2U(L) or A2U(K) cannot adequately explain the sex-dependent elimination of PFOA in rats, and it is unlikely that PFOA-A2U(K) binding would induce A2U nephropathy as seen with, for example, 1,4-dichlorobenzene.
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Affiliation(s)
- Xing Han
- DuPont Haskell Laboratory for Health and Environmental Sciences, Newark, Delaware 19714, USA.
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38
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Ko YH, Cheng CH, Shen TF, Ding ST. Cloning and expression of Tsaiya duck liver fatty acid binding protein. Poult Sci 2004; 83:1832-8. [PMID: 15554058 DOI: 10.1093/ps/83.11.1832] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Liver basic fatty acid (FA)-binding protein (Lb-FABP) cDNA was cloned from the livers of laying Tsaiya ducks and used to generate probes for quantification of the Lb-FABP mRNA in Tsaiya ducks. The full-length Lb-FABP cDNA of the Tsaiya duck was highly homologous with that of the mallard (99%), chicken (88%), and iguana (73%). The amino acid sequence was also highly homologous to Lb-FABP found in birds and reptiles, indicating a similar function of the Tsaiya duck Lb-FABP to those species. The calculated molecular weight for the cloned duck Lb-FABP was 14,043g/mol. The Lb-FABP was highly expressed in the liver of laying Tsaiya ducks and not detectable in heart, ovary, intestine, or adipose tissues. The expression of Tsaiya duck Lb-FABP in the skeletal muscle was also detected, and the sequence was confirmed. The greater expression of the hepatic Lb-FABP in the egg-laying Tsaiya ducks than the prelaying ducks paralleled the higher FA use by the laying ducks. These results suggest that hepatic Lb-FABP may be needed for egg production when FA metabolism is high for the ducks. Feeding laying Tsaiya ducks with diets enriched with 2% docosahexaenoic acid (DHA) oil for 2 wk significantly increased hepatic DHA content compared with in ducks fed a 2% butter basal diet. There was no effect of dietary DHA enrichment on the expression of Lb-FABP in the liver of Tsaiya ducks. The results suggest that even though the Lb-FABP may be involved in hepatic FA metabolism, the effect of individual FA on liver Lb-FABP in laying Tsaiya ducks needs to be further studied.
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Affiliation(s)
- Y H Ko
- Department of Animal Science, National Taiwan University, Taipei, Taiwan
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39
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Divine JK, Staloch LJ, Haveri H, Jacobsen CM, Wilson DB, Heikinheimo M, Simon TC. GATA-4, GATA-5, and GATA-6 activate the rat liver fatty acid binding protein gene in concert with HNF-1alpha. Am J Physiol Gastrointest Liver Physiol 2004; 287:G1086-99. [PMID: 14715527 DOI: 10.1152/ajpgi.00421.2003] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Transcriptional regulation by GATA-4, GATA-5, and GATA-6 in intestine and liver was explored using a transgene constructed from the proximal promoter of the rat liver fatty acid binding protein gene (Fabpl). An immunohistochemical survey detected GATA-4 and GATA-6 in enterocytes, GATA-6 in hepatocytes, and GATA-5 in neither cell type in adult animals. In cell transfection assays, GATA-4 or GATA-5 but not GATA-6 activated the Fabpl transgene solely through the most proximal of three GATA binding sites in the Fabpl promoter. However, all three factors activated transgenes constructed from each Fabpl site upstream of a minimal viral promoter. GATA factors interact with hepatic nuclear factor (HNF)-1alpha, and the proximal Fabpl GATA site adjoins an HNF-1 site. GATA-4, GATA-5, or GATA-6 bounded to HNF-1alpha in solution, and all cooperated with HNF-1alpha to activate the Fabpl transgene. Mutagenizing all Fabpl GATA sites abrogated transgene activation by GATA factors, but GATA-4 activated the mutagenized transgene in the presence of HNF-1alpha. These in vitro results suggested GATA/HNF-1alpha interactions function in Fabpl regulation, and in vivo relevance was determined with subsequent experiments. In mice, the Fabpl transgene was active in enterocytes and hepatocytes, a transgene with mutagenized HNF-1 site was silent, and a transgene with mutagenized GATA sites had identical expression as the native transgene. Mice mosaic for biallelic Gata4 inactivation lost intestinal but not hepatic Fabpl expression in Gata4-deficient cells but not wild-type cells. These results demonstrate GATA-4 is critical for intestinal gene expression in vivo and suggest a specific GATA-4/HNF-1alpha physical and functional interaction in Fabpl activation.
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Affiliation(s)
- Joyce K Divine
- Division of Biology and Biomedical Sciences, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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40
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Her GM, Yeh YH, Wu JL. 435-bp liver regulatory sequence in the liver fatty acid binding protein (L-FABP) gene is sufficient to modulate liver regional expression in transgenic zebrafish. Dev Dyn 2003; 227:347-56. [PMID: 12815620 DOI: 10.1002/dvdy.10324] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Liver fatty acid binding protein (L-FABP) is a small protein that is thought to play an important role in the intracellular binding and trafficking of long chain fatty acids in the liver. Expression of the gene encoding the zebrafish liver fatty acid binding protein is regulated by a 435-bp distal region (-1944 to -1510) of the L-FABP promoter. The 435-bp sequence is sufficient for gene activation in the liver primordia (or bud) and continues to be active in the adult liver when positioned adjacent to the SV40 basal promoter and linked directly to green fluorescent protein. The 435-bp sequence region has two distinct liver regulatory elements, A (-1944 to -1623) and B (-1622 to -1510), and contains multiple putative consensus binding sites. The element A sequence includes two consensus HFH and one HNF-1alpha site and the element B sequence includes one consensus HNF-3beta site. Deletion of an internal 435-bp fragment (-1944 to -1510) including the A and B elements totally ablated the liver-specific activity of the zebrafish L-FABP gene promoter. Deletion of either of the two elements reduces the liver activity. Mutation of the HNF-1alpha site or either of the two HFH sites in the A element or the HNF-3beta site in the B element significantly altered specificity in the liver primordia of transient expression embryos. The importance of the HNF-1alpha consensus binding site in the A element and the HNF-3beta consensus binding site in the B element within the 435-bp distal region of the L-FABP promoter region suggests that combinatorial interactions between multiple regulatory factors are responsible for the gene expression of L-FABP in the liver.
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Affiliation(s)
- Guor Mour Her
- Laboratory of Marine Molecular Biology and Biotechnology, Institute of Zoology, Academia Sinica, Taipei, Taiwan, Republic of China
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41
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Divine JK, McCaul SP, Simon TC. HNF-1alpha and endodermal transcription factors cooperatively activate Fabpl: MODY3 mutations abrogate cooperativity. Am J Physiol Gastrointest Liver Physiol 2003; 285:G62-72. [PMID: 12646418 DOI: 10.1152/ajpgi.00074.2003] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Hepatocyte nuclear factor (HNF)-1alpha plays a central role in intestinal and hepatic gene regulation and is required for hepatic expression of the liver fatty acid binding protein gene (Fabpl). An Fabpl transgene was directly activated through cognate sites by HNF-1alpha and HNF-1beta, as well as five other endodermal factors: CDX-1, C/EBPbeta, GATA-4, FoxA2, and HNF-4alpha. HNF-1alpha activated the Fabpl transgene by as much as 60-fold greater in the presence of the other five endodermal factors than in their absence, accounting for up to one-half the total transgene activation by the group of six factors. This degree of synergistic interaction suggests that multifactor cooperativity is a critical determinant of endodermal gene activation by HNF-1alpha. Mutations in HNF-1alpha that result in maturity onset diabetes of the young (MODY3) provide evidence for the in vivo significance of these synergistic interactions. An R131Q HNF-1alpha MODY3 mutant exhibits complete loss of synergistic activation in concert with the other endodermal transcription factors despite wild-type transactivation ability in their absence. Furthermore, whereas wild-type HNF-1alpha exhibited pairwise cooperative synergy with each of the other five factors, the R131Q mutant could synergize only with GATA-4 and C/EBPbeta. Selective loss of synergy with other endodermal transcription factors accompanied by retention of native transactivation ability in an HNF-1alpha MODY mutant suggests in vivo significance for cooperative synergy.
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Affiliation(s)
- Joyce K Divine
- Division of Biology and Biomedical Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA
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42
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Hung DY, Burczynski FJ, Chang P, Lewis A, Masci PP, Siebert GA, Anissimov YG, Roberts MS. Fatty acid binding protein is a major determinant of hepatic pharmacokinetics of palmitate and its metabolites. Am J Physiol Gastrointest Liver Physiol 2003; 284:G423-33. [PMID: 12444013 DOI: 10.1152/ajpgi.00328.2002] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Disposition kinetics of [(3)H]palmitate and its low-molecular-weight metabolites in perfused rat livers were studied using the multiple-indicator dilution technique, a selective assay for [(3)H]palmitate and its low-molecular-weight metabolites, and several physiologically based pharmacokinetic models. The level of liver fatty acid binding protein (L-FABP), other intrahepatic binding proteins (microsomal protein, albumin, and glutathione S-transferase) and the outflow profiles of [(3)H]palmitate and metabolites were measured in four experimental groups of rats: 1) males; 2) clofibrate-treated males; 3) females; and 4) pregnant females. A slow-diffusion/bound model was found to better describe the hepatic disposition of unchanged [(3)H]palmitate than other pharmacokinetic models. The L-FABP levels followed the order: pregnant female > clofibrate-treated male > female > male. Levels of other intrahepatic proteins did not differ significantly. The hepatic extraction ratio and mean transit time for unchanged palmitate, as well as the production of low-molecular-weight metabolites of palmitate and their retention in the liver, increased with increasing L-FABP levels. Palmitate metabolic clearance, permeability-surface area product, retention of palmitate by the liver, and cytoplasmic diffusion constant for unchanged [(3)H]palmitate also increased with increasing L-FABP levels. It is concluded that the variability in hepatic pharmacokinetics of unchanged [(3)H]palmitate and its low-molecular-weight metabolites in perfused rat livers is related to levels of L-FABP and not those of other intrahepatic proteins.
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Affiliation(s)
- Daniel Y Hung
- Department of Medicine, Princess Alexandra Hospital, University of Queensland, Woolloongabba, Queensland 4102, Australia
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43
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Esteves A, Portillo V, Ehrlich R. Genomic structure and expression of a gene coding for a new fatty acid binding protein from Echinococcus granulosus. BIOCHIMICA ET BIOPHYSICA ACTA 2003; 1631:26-34. [PMID: 12573446 DOI: 10.1016/s1388-1981(02)00321-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
This work describes a new gene coding for a fatty acid binding protein (FABP) in the parasite Echinococcus granulosus, named EgFABP2. The complete gene structure, including the promoter sequence, is reported. The genomic coding domain organisation of the previously reported E. granulosus FABP gene (EgFABP1) has been also determined. The corresponding polypeptide chains share 76% of identical residues and an overall 96% of similarity. The two EgFABPs present the highest amino acid homologies with the mammalian FABP subfamily containing heart-FABPs (H-FABPs). The coding sequences of both genes are interrupted by a single intron located in the position of the third intron reported for vertebrate FABP genes. Both genes are expressed in the protoscolex stage of the parasite. The promoter region of EgFABP2 presents several consensus putative cis-acting elements found in other members of the family, suggesting interesting possible mechanisms involved in the host-parasite adaptation.
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Affiliation(s)
- Adriana Esteves
- Sección Bioquímica, Facultad de Ciencias, Iguá 4225, 11400, Montevideo, Uruguay.
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Ding ST, Lilburn MS. The ontogeny of fatty acid-binding protein in turkey (Meleagridis gallopavo) intestine and yolk sac membrane during embryonic and early posthatch development. Poult Sci 2002; 81:1065-70. [PMID: 12162346 DOI: 10.1093/ps/81.7.1065] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Experiments were conducted to confirm the existence and ontogeny of fatty acid binding protein (FABP) in the intestine and yolk sac membrane of turkey poults (Meleagridis gallopavo) during embryonic and early posthatch development. Intestinal (I-) FABP was measured using an immunoblot procedure incorporating anti-chick liver (L-)FABP antisera. FABP activity in both tissues was also confirmed with a ligand-binding assay incorporating 14C-oleic acid. I-FABP did not cross-react with chick L-FABP antisera until hatch, embryonic day 28 (ED 28), after which there was a 39% increase in I-FABP concentration through the first 3 d posthatch (PD 3). FABP concentration calculated on a total intestinal basis (ng/intestine), however, increased 10-fold through PD 6. Specific activity [disintegrations per minute (dpm)/ mg cytosolic protein] was greatest at hatch and decreased slightly thereafter, whereas specific activity of FABP in the yolk sac membrane peaked between ED 16 and ED 19 and then declined. Total yolk sac activity (dpm/yolk sac membrane), however, plateaued at ED 22 before declining to low levels by PD 3, coincident with the period of maximal lipid transfer out of the yolk.
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Affiliation(s)
- S T Ding
- Department of Animal Science, National Taiwan University, Taipei, Republic of China
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45
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Ding ST, Bacon WL, Lilburn MS. The development of an immunoblotting assay for the quantification of liver fatty acid-binding protein during embryonic and early posthatch development of turkeys (Meleagridis gallopavo). Poult Sci 2002; 81:1057-64. [PMID: 12162345 DOI: 10.1093/ps/81.7.1057] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Turkey (Meleagridis gallopavo) liver cytosolic fatty acid binding protein (FABP) was purified and used as a standard for quantification. An immunoblotting procedure was developed to study the ontogeny of liver cytosolic FABP during embryonic and early posthatch development in turkey poults. Liver FABP activity was also determined indirectly through the use of gel filtration chromatography followed by a ligand-binding assay. The specific activity of liver FABP (ng/mg of cytosolic protein) increased with length of incubation, peaking initially at Day 22, declining between Days 22 and 25, and increasing again from hatch (Day 28) to 6 d posthatch. The specific activity of liver FABP increased 12-fold between Day 13 of incubation and 6 d posthatch compared with total activity, which increased from 946 to 1.01 x 10(6) ng/liver during the same period, a 1,067-fold increase. The results from both analytical procedures were similar, suggesting that the immunoblot method could be used to quantify liver FABP concentrations. The observed increases in FABP activity throughout the embryonic period and first days after hatching paralleled increases in liver lipid concentration. Therefore, liver FABP may be associated with hepatocyte fatty acid transport and metabolism during the latter stages of incubation and early posthatch period.
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Affiliation(s)
- S T Ding
- Department of Animal Science, National Taiwan University, Taipai, Republic of China
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Abstract
Malabsorption of carbohydrates, lipids, amino acids, minerals and vitamins has been described in the elderly. The ability of the intestine to adapt may be impaired in the elderly and this may lead to further malnutrition. Dietary manipulation may prove to be useful to enhance the needed intestinal absorption with ageing. There is an age-associated increase in the prevalence of dyslipidaemia as well as diabetes. These conditions may benefit from nutritional intervention targeted at reducing the absorption of some nutrients. With the continued characterization of the proteins involved in sterol and fatty acid absorption, therapeutic interventions to modify absorption may become available in the future.
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Affiliation(s)
- Trudy Woudstra
- Division of Gastroenterology, Department of Medicine, University of Alberta, Edmonton, Canada
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Gedde-Dahl A, Kulseth MA, Ranheim T, Drevon CA, Rustan AC. Reduced secretion of triacylglycerol in CaCo-2 cells transfected with intestinal fatty acid-binding protein. Lipids 2002; 37:61-8. [PMID: 11876264 DOI: 10.1007/s11745-002-0864-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The fatty acid-binding proteins are hypothesized to be involved in cellular fatty acid transport and trafficking. We established CaCo-2 cells stably transfected with intestinal fatty acid-binding protein (I-FABP) and examined how the expression of this protein may influence fatty acid metabolism. I-FABP expression was detectable in I-FABP-transfected cells, whereas parent CaCo-2 cells as well as mock-transfected cells failed to express detectable levels of I-FABP mRNA or protein at any stage of differentiation. For studies of lipid metabolism, cells were incubated with [14C]oleic acid in taurocholate micelles containing monoolein, and distribution of labeled fatty acid in cellular and secreted lipids was examined. In one transfected cell clone, expressing the highest level of I-FABP, labeled cellular triacylglycerol increased approximately twofold as compared to control cells. The level of intracellular triacylglycerol in two other I-FABP-transfected clones resembled that of control cells. However, secretion of triacylglycerol was markedly reduced in all the I-FABP-expressing cell lines. Our data suggest that increased expression of I-FABP leads to reduced triacylglycerol secretion in intestinal cells.
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Affiliation(s)
- Ane Gedde-Dahl
- Department of Pharmacology, School of Pharmacy, University of Oslo, Norway.
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Galluzzi JR, Cupples LA, Otvos JD, Wilson PW, Schaefer EJ, Ordovas JM. Association of the A/T54 polymorphism in the intestinal fatty acid binding protein with variations in plasma lipids in the Framingham Offspring Study. Atherosclerosis 2001; 159:417-24. [PMID: 11730822 DOI: 10.1016/s0021-9150(01)00517-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We investigated the potential role of the genetic variation at the intestinal fatty acid binding protein gene (FABP2) in influencing lipid levels in a representative sample of the Framingham Offspring Study participants (n=1930). In men, the T54 allele was associated with significantly higher LDL-cholesterol (3.47+/-0.83 vs. 3.36+/-0.83 mmol/l; P<0.047), and ApoB (1.04+/-0.23 vs. 1.01+/-0.24 g/l; P<0.020) after adjustment for familial relationship, age, BMI, smoking, alcohol intake and the use of beta-blockers compared with the A54 allele. This relationship with ApoB continued to be significant after adjustment for APOE genotype (P<0.034). In women, the T54 allele was associated with significantly higher total-cholesterol (5.32+/-1.01 vs. 5.17+/-0.98 mmol/l; P<0.049) and LDL-cholesterol (3.31+/-0.93 vs. 3.18+/-0.85 mmol/l; P<0.023) after adjustment for covariates and menopausal status, estrogen therapy and APOE genotype. In men, the T54 allele was associated with significantly higher levels of small VLDL and lower levels of large HDL. Moreover, there was no significant relationship between FABP2 alleles and lipoprotein diameter or the prevalence of coronary heart disease in both genders. Our data are consistent with the T54 IFABP increasing the flux of lipids through the enterocyte leading to an increase in chylomicron secretion.
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Affiliation(s)
- J R Galluzzi
- Lipid Metabolism Laboratory, Jean Mayer-USDA Human Nutrition Research Center on Aging at Tufts University, 711 Washington Street, Boston, MA 02111, USA.
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Galluzzi JR, Cupples LA, Meigs JB, Wilson PW, Schaefer EJ, Ordovas JM. Association of the Ala54-Thr polymorphism in the intestinal fatty acid-binding protein with 2-h postchallenge insulin levels in the Framingham Offspring Study. Diabetes Care 2001; 24:1161-6. [PMID: 11423496 DOI: 10.2337/diacare.24.7.1161] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE To investigate the association of variants of the intestinal fatty acid-binding protein gene (FABP2) with fasting and postchallenge glucose and insulin levels, HbA(1c), and prevalence of type 2 diabetes in a separate sample of men and women. RESEARCH DESIGN AND METHODS Subjects were participants in the Framingham Offspring Study, a long-term community-based prospective observational study of risk factors for cardiovascular disease. The study sample consisted of 762 men and 922 women. RESULTS In women, carriers of the Thr54 allele had significantly higher 2-h postchallenge insulin levels than noncarriers (104.4 +/- 73.0 vs. 93.4 +/- 61.5 microU/ml; P = 0.0139). This relationship remained significant after adjustment for familial relationship, age, BMI, triglycerides, APOE genotype, smoking, alcohol intake, the use of beta-blockers, menopausal status, and estrogen therapy. No such significant association was observed in men. In both men and women, there were no statistical associations between the FABP2 polymorphism and BMI, fasting glucose, fasting insulin, 2-h postchallenge glucose levels, HbA(1c), and prevalence of type 2 diabetes. CONCLUSIONS These results suggest that the FABP2 Thr54 allele may have a minor contribution to the insulin resistance syndrome in a white general population.
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Affiliation(s)
- J R Galluzzi
- Lipid Metabolism Laboratory, Jean Mayer-USDA Human Nutrition Research Center on Aging, Tufts University, Boston, Massachusetts 02111, USA.
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50
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Dubé N, Delvin E, Yotov W, Garofalo C, Bendayan M, Veerkamp JH, Levy E. Modulation of intestinal and liver fatty acid-binding proteins in Caco-2 cells by lipids, hormones and cytokines. J Cell Biochem 2001; 81:613-20. [PMID: 11329616 DOI: 10.1002/jcb.1090] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Intestinal and liver fatty acid binding proteins (I- and L-FABP) are thought to play a role in enterocyte fatty acid (FA) trafficking. Their modulation by cell differentiation and various potential effectors was investigated in the human Caco-2 cell line. With the acquisition of enterocytic features, Caco-2 cells seeded on plastic progressively increased L-FABP quantities, whereas I-FABP was not detectable even very late in the maturation process. On permeable filters that improved differentiation markers (sucrase, alkaline phosphatase, transepithelial resistance), Caco-2 cells furthered their L-FABP content and expressed I-FABP. Western blot analysis showed a significant increase in I- and L-FABP expression following an 8-hour incubation period with butyric acid, oleic acid, and phosphatidylcholine. However, in all cases, I-FABP levels were higher than L-FABP concentrations regardless of the lipid substrates added. Similarly, hydrocortisone and insulin enhanced the cellular content of I- and L-FABP whereas leptin triggered I-FABP expression only after an 8-hour incubation. Finally, tumor necrosis factor-alpha was more effective in increasing the cytosolic amount of I-FABP levels. In conclusion, our data demonstrate that I-FABP expression is limited to fully differentiated Caco-2 cells and can be more easily regulated than L-FABP by lipids, hormones, and cytokines.
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Affiliation(s)
- N Dubé
- Centre de Recherche, Hôpital Sainte-Justine and Department of Nutrition, Université de Montréal, Montréal, Quebec, Canada H3T 1C5
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