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Jabłońska B, Mrowiec S. The Role of Immunonutrition in Patients Undergoing Pancreaticoduodenectomy. Nutrients 2020; 12:E2547. [PMID: 32842475 PMCID: PMC7551458 DOI: 10.3390/nu12092547] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 08/18/2020] [Accepted: 08/20/2020] [Indexed: 12/11/2022] Open
Abstract
Pancreaticoduodenectomy (PD) is one of the most difficult and complex surgical procedures in abdominal surgery. Malnutrition and immune dysfunction in patients with pancreatic cancer (PC) may lead to a higher risk of postoperative infectious complications. Although immunonutrition (IN) is recommended for enhanced recovery after surgery (ERAS) in patients undergoing PD for 5-7 days perioperatively, its role in patients undergoing pancreatectomy is still unclear and controversial. It is known that the proper surgical technique is very important in order to reduce a risk of postoperative complications, such as a pancreatic fistula, and to improve disease-free survival in patients following PD. However, it has been proven that IN decreases the risk of infectious complications, and shortens hospital stays in patients undergoing PD. This is a result of the impact on altered inflammatory responses in patients with cancer. Both enteral and parenteral, as well as preoperative and postoperative IN, using various nutrients, such as glutamine, arginine, omega-3 fatty acids and nucleotides, is administered. The most frequently used preoperative oral supplementation is recommended. The aim of this paper is to present the indications and benefits of IN in patients undergoing PD.
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Affiliation(s)
- Beata Jabłońska
- Department of Digestive Tract Surgery, Medical University of Silesia, Medyków 14 St., 40-752 Katowice, Poland;
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2
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Dengler F. Activation of AMPK under Hypoxia: Many Roads Leading to Rome. Int J Mol Sci 2020; 21:ijms21072428. [PMID: 32244507 PMCID: PMC7177550 DOI: 10.3390/ijms21072428] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 03/26/2020] [Accepted: 03/30/2020] [Indexed: 12/13/2022] Open
Abstract
AMP-activated protein kinase (AMPK) is known as a pivotal cellular energy sensor, mediating the adaptation to low energy levels by deactivating anabolic processes and activating catabolic processes in order to restore the cellular ATP supply when the cellular AMP/ATP ratio is increased. Besides this well-known role, it has also been shown to exert protective effects under hypoxia. While an insufficient supply with oxygen might easily deplete cellular energy levels, i.e., ATP concentration, manifold other mechanisms have been suggested and are heavily disputed regarding the activation of AMPK under hypoxia independently from cellular AMP concentrations. However, an activation of AMPK preceding energy depletion could induce a timely adaptation reaction preventing more serious damage. A connection between AMPK and the master regulator of hypoxic adaptation via gene transcription, hypoxia-inducible factor (HIF), has also been taken into account, orchestrating their concerted protective action. This review will summarize the current knowledge on mechanisms of AMPK activation under hypoxia and its interrelationship with HIF.
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Affiliation(s)
- Franziska Dengler
- Institute of Veterinary Physiology, University of Leipzig, D-04103 Leipzig, Germany
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Dengler F, Gäbel G. The Fast Lane of Hypoxic Adaptation: Glucose Transport Is Modulated via A HIF-Hydroxylase-AMPK-Axis in Jejunum Epithelium. Int J Mol Sci 2019; 20:ijms20204993. [PMID: 31601024 PMCID: PMC6834319 DOI: 10.3390/ijms20204993] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 10/07/2019] [Accepted: 10/08/2019] [Indexed: 12/21/2022] Open
Abstract
The intestinal epithelium is able to adapt to varying blood flow and, thus, oxygen availability. Still, the adaptation fails under pathologic situations. A better understanding of the mechanisms underlying the epithelial adaptation to hypoxia could help to improve the therapeutic approach. We hypothesized that the short-term adaptation to hypoxia is mediated via AMP-activated protein kinase (AMPK) and that it is coupled to the long-term adaptation by a common regulation mechanism, the HIF-hydroxylase enzymes. Further, we hypothesized the transepithelial transport of glucose to be part of this short-term adaptation. We conducted Ussing chamber studies using isolated lagomorph jejunum epithelium and cell culture experiments with CaCo-2 cells. The epithelia and cells were incubated under 100% and 21% O2, respectively, with the panhydroxylase inhibitor dimethyloxalylglycine (DMOG) or under 1% O2. We showed an activation of AMPK under hypoxia and after incubation with DMOG by Western blot. This could be related to functional effects like an impairment of Na+-coupled glucose transport. Inhibitor studies revealed a recruitment of glucose transporter 1 under hypoxia, but not after incubation with DMOG. Summing up, we showed an influence of hydroxylase enzymes on AMPK activity and similarities between hypoxia and the effects of hydroxylase inhibition on functional changes.
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Affiliation(s)
- Franziska Dengler
- Institute of Veterinary Physiology, University of Leipzig, 04103 Leipzig, Germany.
| | - Gotthold Gäbel
- Institute of Veterinary Physiology, University of Leipzig, 04103 Leipzig, Germany.
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4
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Dengler F, Rackwitz R, Pfannkuche H, Gäbel G. Glucose transport across lagomorph jejunum epithelium is modulated by AMP-activated protein kinase under hypoxia. J Appl Physiol (1985) 2017; 123:1487-1500. [PMID: 28860168 DOI: 10.1152/japplphysiol.00436.2017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The gastrointestinal epithelium possesses adaptation mechanisms to cope with huge variations in blood flow and subsequently oxygenation. Since sufficient energy supply is crucial under hypoxic conditions, glucose uptake especially must be regulated by these adaptation mechanisms. Therefore, we investigated glucose transport under hypoxic conditions. Jejunal epithelia of rabbits were incubated in Ussing chambers under short-circuit current conditions. Hypoxia was simulated by gassing with 1% O2 instead of 100% O2. The activity of sodium-coupled glucose transporter-1 (SGLT-1) was assessed by measuring the increase of short circuit current ( Isc) after the addition of 2 mM glucose to the mucosal buffer solution. We observed decreased activity of SGLT-1 after hypoxia compared with control conditions. To investigate underlying mechanisms, epithelia were exposed to agonists and antagonists of AMP-activated protein kinase (AMPK) before assessment of SGLT-1-mediated transport and the pAMPK/AMPK protein ratio. Preincubation with the antagonist restored SGLT-1 activity under hypoxic conditions to the level of control conditions, indicating an involvement of AMPK in the downregulation of SGLT-1 activity under hypoxia, which was confirmed in Western blot analysis of pAMPK/AMPK. Transepithelial flux studies using radioactively labeled glucose, ortho-methyl-glucose, fructose, and mannitol revealed no changes after hypoxic incubation. Therefore, we could exclude a decreased transepithelial glucose transport rate and increased paracellular conductance under hypoxia. In conclusion, our study hints at a decreased activity of SGLT-1 under hypoxic conditions in an AMPK-dependent manner. However, transepithelial transport of glucose is maintained. Therefore, we suggest other transport mechanisms, especially glucose transporter 1 and/or 2 to substitute SGLT-1 under hypoxia. NEW & NOTEWORTHY To our knowledge, this is the first approach to simulate hypoxia and study its effects in the jejunal epithelium using the Ussing chamber technique. We were able show that AMPK plays a role in the downregulation of SGLT-1 and that there seems to be an upregulation of other glucose transport mechanisms in the apical membrane of lagomorph jejunum epithelium under hypoxia, securing the epithelial energy supply and thus integrity.
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Affiliation(s)
| | - Reiko Rackwitz
- Institute of Veterinary Physiology, University of Leipzig , Germany
| | - Helga Pfannkuche
- Institute of Veterinary Physiology, University of Leipzig , Germany
| | - Gotthold Gäbel
- Institute of Veterinary Physiology, University of Leipzig , Germany
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5
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Mundi MS, Shah M, Hurt RT. When Is It Appropriate to Use Glutamine in Critical Illness? Nutr Clin Pract 2016; 31:445-50. [PMID: 27246308 DOI: 10.1177/0884533616651318] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Glutamine is a nonessential amino acid, which under trauma or critical illness can become essential. A number of historic small single-center randomized controlled trials (RCTs) have demonstrated positive treatment effects on clinical outcomes with glutamine supplementation. Meta-analyses based on these trials demonstrated a significant reduction in hospital mortality, intensive care unit (ICU) length of stay (LOS), and hospital LOS with intravenous (IV) glutamine. Similar results were not noted in 2 large multicenter RCTs (REDOXS and MetaPlus) assessing the efficacy of glutamine supplementation in ventilated ICU patients. The REDOXS trial of 40 ICUs randomized 1223 ventilated ICU patients to glutamine (IV and enteral), antioxidants, both glutamine and antioxidants, or placebo. The main conclusions were a trend toward increased 28-day mortality and significant increased hospital and 6-month mortality in those who received glutamine. The MetaPlus trial of 14 ICUs, which randomized 301 ventilated ICU patients to glutamine-enriched enteral vs an isocaloric diet, noted increased 6-month mortality in the glutamine-supplemented group. Newer RCTs have focused on specific populations and have demonstrated benefits in burn and elective surgery patients with glutamine supplementation. Whether larger studies will confirm these findings is yet to be determined. Recent American Society for Parenteral and Enteral Nutrition guidelines recommend that IV and enteral glutamine should not be used in the critical care setting based on the moderate quality of evidence available. We agree with these recommendations and would encourage larger multicenter studies to evaluate the risks and benefits of glutamine in burn and elective surgery patients.
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Affiliation(s)
- Manpreet S Mundi
- Division of Endocrinology, Mayo Clinic, Rochester, Minnesota, USA
| | - Meera Shah
- Division of Endocrinology, Mayo Clinic, Rochester, Minnesota, USA
| | - Ryan T Hurt
- Division of Endocrinology, Mayo Clinic, Rochester, Minnesota, USA General Internal Medicine, Mayo Clinic, Rochester, Minnesota, USA Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, USA Division of Gastroenterology, Hepatology, Nutrition, University of Louisville School of Medicine, Louisville, Kentucky, USA
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6
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Wojtal KA, Cee A, Lang S, Götze O, Frühauf H, Geier A, Pastor-Anglada M, Torres-Torronteras J, Martí R, Fried M, Lutz TA, Maggiorini M, Gassmann M, Rogler G, Vavricka SR. Downregulation of duodenal SLC transporters and activation of proinflammatory signaling constitute the early response to high altitude in humans. Am J Physiol Gastrointest Liver Physiol 2014; 307:G673-88. [PMID: 24970780 DOI: 10.1152/ajpgi.00353.2013] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Solute carrier (SLC) transporters mediate the uptake of biologically active compounds in the intestine. Reduced oxygenation (hypoxia) is an important factor influencing intestinal homeostasis. The aim of this study was to investigate the pathophysiological consequences of hypoxia on the expression and function of SLCs in human intestine. Hypoxia was induced in human intestinal epithelial cells (IECs) in vitro (0.2; 1% O2 or CoCl2). For human in vivo studies, duodenal biopsies and serum samples were obtained from individuals (n = 16) acutely exposed to 4,554 meters above sea levels. Expression of relevant targets was analyzed by quantitative PCR, Western blotting, or immunofluorescence. Serum levels of inflammatory mediators and nucleosides were determined by ELISA and LC/MS-MS, respectively. In the duodenum of volunteers exposed to high altitude we observed decreased mRNA levels of apical sodium-dependent bile acid transporter (ASBT), concentrative nucleoside transporters 1/2 (CNT1/2), organic anion transporting polypeptide 2B1 (OATP2B1), organic cation transporter 2 (OCTN2), peptide transporter 1 (PEPT1), serotonin transporter (SERT), and higher levels of IFN-γ, IL-6, and IL-17A. Serum levels of IL-10, IFN-γ, matrix metalloproteinase-2 (MMP-2), and serotonin were elevated, whereas the levels of uridine decreased upon exposure to hypoxia. Hypoxic IECs showed reduced levels of equilibrative nucleoside transporter 2 (ENT2), OCTN2, and SERT mRNAs in vitro, which was confirmed on the protein level and was accompanied by activation of ERK1/2, increase of hypoxia-inducible factor (HIF) proteins, and production of IL-8 mRNA. Costimulation with IFN-γ and IL-6 during hypoxia further decreased the expression of SERT, ENT2, and CNT2 in vitro. Reduced oxygen supply affects the expression pattern of duodenal SLCs that is accompanied by changes in serum levels of proinflammatory cytokines and biologically active compounds demonstrating that intestinal transport is affected during systemic exposure to hypoxia in humans.
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Affiliation(s)
- Kacper A Wojtal
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, University Hospital Zurich, Zurich, Switzerland;
| | - Alexandra Cee
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Silvia Lang
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Oliver Götze
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, University Hospital Zurich, Zurich, Switzerland; Department of Gastroenterology and Hepatology, University Clinic Würzburg, Würzburg, Germany
| | - Heiko Frühauf
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, University Hospital Zurich, Zurich, Switzerland; Division of Gastroenterology and Hepatology, Hospital Triemli, Zurich, Switzerland
| | - Andreas Geier
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, University Hospital Zurich, Zurich, Switzerland; Department of Gastroenterology and Hepatology, University Clinic Würzburg, Würzburg, Germany
| | - Marçal Pastor-Anglada
- Pharmacology and Experimental Therapeutics, Department of Biochemistry and Molecular Biology, Institute of Biomedicine and Oncology Programme, National Biomedical Research Institute of Liver and Gastrointestinal Disease (CIBER EHD), University of Barcelona, Barcelona, Spain
| | - Javier Torres-Torronteras
- Neuromuscular and Mitochondrial Disorders Unit, and Biomedical Network Research Centre on Rare Diseases (CIBERER), Vall d'Hebron Institut de Recerca, Autonomous University of Barcelona, Barcelona, Spain
| | - Ramon Martí
- Neuromuscular and Mitochondrial Disorders Unit, and Biomedical Network Research Centre on Rare Diseases (CIBERER), Vall d'Hebron Institut de Recerca, Autonomous University of Barcelona, Barcelona, Spain
| | - Michael Fried
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Thomas A Lutz
- Institute of Veterinary Physiology, University of Zurich, Zurich, Switzerland; Institute of Laboratory Animal Science, University of Zurich, Zurich, Switzerland; Zurich Center for Integrative Human Physiology (ZIHP), Zurich, Switzerland
| | - Marco Maggiorini
- Intensive Care Unit, Department of Internal Medicine, University of Zurich, Zurich, Switzerland
| | - Max Gassmann
- Institute of Veterinary Physiology, University of Zurich, Zurich, Switzerland; Cayetano Heredia University (UPCH), Lima, Peru; and Zurich Center for Integrative Human Physiology (ZIHP), Zurich, Switzerland
| | - Gerhard Rogler
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, University Hospital Zurich, Zurich, Switzerland; Zurich Center for Integrative Human Physiology (ZIHP), Zurich, Switzerland
| | - Stephan R Vavricka
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, University Hospital Zurich, Zurich, Switzerland; Division of Gastroenterology and Hepatology, Hospital Triemli, Zurich, Switzerland; Zurich Center for Integrative Human Physiology (ZIHP), Zurich, Switzerland
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7
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Suh HN, Lee YJ, Kim MO, Ryu JM, Han HJ. Glucosamine-induced Sp1 O-GlcNAcylation ameliorates hypoxia-induced SGLT dysfunction in primary cultured renal proximal tubule cells. J Cell Physiol 2014; 229:1557-68. [PMID: 24591095 DOI: 10.1002/jcp.24599] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Accepted: 02/27/2014] [Indexed: 12/22/2022]
Abstract
The aim of this study is to determine whether GlcN could recover the endoplasmic reticulum (ER) stress-induced dysfunction of Na(+) /glucose cotransporter (SGLT) in renal proximal tubule cells (PTCs) under hypoxia. With the rabbit model, the renal ischemia induced tubulointerstitial abnormalities and decreased SGLTs expression in tubular brush-border, which were recovered by GlcN. Thus, the protective mechanism of GlcN against renal ischemia was being examined by using PTCs. Hypoxia decreased the level of protein O-GlcNAc and the expression of O-GlcNAc transferase (OGT) while increased O-GlcNAcase (OGA) and these were reversed by GlcN. Hypoxia also decreased the expression of SGLTs (SGLT1 and 2) and [(14) C]-α-methyl-D-glucopyranoside (α-MG) uptake which were recovered by GlcN and PUGNAc (OGA inhibitor). Hypoxia enhanced reactive oxygen species (ROS) and then ER stress proteins, glucose-regulated protein 78 (GRP78), and C/EBP-homologous protein (CHOP). However, the expression of GRP78 increased till 6 h and then decreased whereas CHOP increased gradually. Moreover, decreased GRP78 and increased CHOP were reversed by NAC (antioxidant) and GlcN. GlcN ameliorated hypoxia-induced decrease of O-GlcNAc modification of Sp1 but OGT or Sp1 siRNAs blocked the recovery effect of GlcN on SGLT expression and α-MG uptake. In addition, hypoxia-decreased GRP78 and HIF-1α expression was reversed by GlcN but OGT siRNA or Sp1 siRNA ameliorated the effect of GlcN. When PTCs were transfected with GRP78 siRNA or HIF-1α siRNA, SGLT expression and α-MG uptake was decreased. Taken together, these data suggest that GlcN-induced O-GlcNAc modified Sp1 with stimulating GRP78 and HIF-1α activity ameliorate hypoxia-induced SGLT dysfunction in renal PTCs. J. Cell. Physiol. 229: 1557-1568, 2014. © 2014 Wiley Periodicals, Inc.
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Affiliation(s)
- Han Na Suh
- Department of Veterinary Physiology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Republic of Korea
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8
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Ward JBJ, Keely SJ, Keely SJ. Oxygen in the regulation of intestinal epithelial transport. J Physiol 2014; 592:2473-89. [PMID: 24710059 DOI: 10.1113/jphysiol.2013.270249] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The transport of fluid, nutrients and electrolytes to and from the intestinal lumen is a primary function of epithelial cells. Normally, the intestine absorbs approximately 9 l of fluid and 1 kg of nutrients daily, driven by epithelial transport processes that consume large amounts of cellular energy and O2. The epithelium exists at the interface of the richly vascularised mucosa, and the anoxic luminal environment and this steep O2 gradient play a key role in determining the expression pattern of proteins involved in fluid, nutrient and electrolyte transport. However, the dynamic nature of the splanchnic circulation necessitates that the epithelium can evoke co-ordinated responses to fluctuations in O2 availability, which occur either as a part of the normal digestive process or as a consequence of several pathophysiological conditions. While it is known that hypoxia-responsive signals, such as reactive oxygen species, AMP-activated kinase, hypoxia-inducible factors, and prolyl hydroxylases are all important in regulating epithelial responses to altered O2 supply, our understanding of the molecular mechanisms involved is still limited. Here, we aim to review the current literature regarding the role that O2 plays in regulating intestinal transport processes and to highlight areas of research that still need to be addressed.
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Affiliation(s)
- Joseph B J Ward
- Department of Molecular Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Simon J Keely
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Newcastle NSW, Australia
| | - Stephen J Keely
- Department of Molecular Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland
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9
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Zapata-Morales JR, Galicia-Cruz OG, Franco M, Martinez Y Morales F. Hypoxia-inducible factor-1α (HIF-1α) protein diminishes sodium glucose transport 1 (SGLT1) and SGLT2 protein expression in renal epithelial tubular cells (LLC-PK1) under hypoxia. J Biol Chem 2013; 289:346-57. [PMID: 24196951 DOI: 10.1074/jbc.m113.526814] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In this work, we demonstrated the regulation of glucose transporters by hypoxia inducible factor-1α (HIF-1α) activation in renal epithelial cells. LLC-PK1 monolayers were incubated for 1, 3, 6, or 12 h with 0% or 5% O2 or 300 μm cobalt (CoCl2). We evaluated the effects of hypoxia on the mRNA and protein expression of HIF-1α and of the glucose transporters SGLT1, SGLT2, and GLUT1. The data showed an increase in HIF-1α mRNA and protein expression under the three evaluated conditions (p < 0.05 versus t = 0). An increase in GLUT1 mRNA (12 h) and protein expression (at 3, 6, and 12 h) was observed (p < 0.05 versus t = 0). SGLT1 and SGLT2 mRNA and protein expression decreased under the three evaluated conditions (p < 0.05 versus t = 0). In conclusion, our results suggest a clear decrease in the expression of the glucose transporters SGLT1 and SGLT2 under hypoxic conditions which implies a possible correlation with increased expression of HIF-1α.
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Affiliation(s)
- Juan R Zapata-Morales
- From the Department of Pharmacology, School of Medicine, University of San Luis Potosi, 78210 San Luis Potosi, Mexico and
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10
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Yang C, Albin DM, Wang Z, Stoll B, Lackeyram D, Swanson KC, Yin Y, Tappenden KA, Mine Y, Yada RY, Burrin DG, Fan MZ, Arrese M, Riquelme A. Apical Na+-D-glucose cotransporter 1 (SGLT1) activity and protein abundance are expressed along the jejunal crypt-villus axis in the neonatal pig. Am J Physiol Gastrointest Liver Physiol 2011; 300:G60-70. [PMID: 21030609 PMCID: PMC3025512 DOI: 10.1152/ajpgi.00208.2010] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Gut apical Na(+)-glucose cotransporter 1 (SGLT1) activity is high at the birth and during suckling, thus contributing substantially to neonatal glucose homeostasis. We hypothesize that neonates possess high SGLT1 maximal activity by expressing apical SGLT1 protein along the intestinal crypt-villus axis via unique control mechanisms. Kinetics of SGLT1 activity in apical membrane vesicles, prepared from epithelial cells sequentially isolated along the jejunal crypt-villus axis from neonatal piglets by the distended intestinal sac method, were measured. High levels of maximal SGLT1 uptake activity were shown to exist along the jejunal crypt-villus axis in the piglets. Real-time RT-PCR analyses showed that SGLT1 mRNA abundance was lower (P < 0.05) by 30-35% in crypt cells than in villus cells. There were no significant differences in SGLT1 protein abundances on the jejunal apical membrane among upper villus, middle villus, and crypt cells, consistent with the immunohistochemical staining pattern. Higher abundances (P < 0.05) of total eukaryotic initiation factor 4E (eIF4E) protein and eIE4E-binding protein 1 γ-isoform in contrast to a lower (P < 0.05) abundance of phosphorylated (Pi) eukaryotic elongation factor 2 (eEF2) protein and the eEF2-Pi to total eEF2 abundance ratio suggest higher global protein translational efficiency in the crypt cells than in the upper villus cells. In conclusion, neonates have high intestinal apical SGLT1 uptake activity by abundantly expressing SGLT1 protein in the epithelia and on the apical membrane along the entire crypt-villus axis in association with enhanced protein translational control mechanisms in the crypt cells.
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Affiliation(s)
- Chengbo Yang
- 1Center for Nutrition Modeling, Department of Animal and Poultry Science, University of Guelph, Guelph, Ontario, Canada;
| | - David M. Albin
- 2Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, Illinois;
| | - Zirong Wang
- 3College of Animal Science, Xinjiang Agricultural University, Urumqi, Xinjiang, China;
| | - Barbara Stoll
- 4Department of Agriculture/Agricultural Research Service, Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas;
| | - Dale Lackeyram
- 1Center for Nutrition Modeling, Department of Animal and Poultry Science, University of Guelph, Guelph, Ontario, Canada;
| | - Kendall C. Swanson
- 1Center for Nutrition Modeling, Department of Animal and Poultry Science, University of Guelph, Guelph, Ontario, Canada;
| | - Yulong Yin
- 5Institute of Subtropical Agriculture, the Chinese Academy of Sciences, Changsha, Hunan, China; and
| | - Kelly A. Tappenden
- 2Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, Illinois;
| | - Yoshinori Mine
- 6Department of Food Science, University of Guelph, Guelph, Ontario, Canada
| | - Rickey Y. Yada
- 6Department of Food Science, University of Guelph, Guelph, Ontario, Canada
| | - Douglas G. Burrin
- 4Department of Agriculture/Agricultural Research Service, Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas;
| | - Ming Z. Fan
- 1Center for Nutrition Modeling, Department of Animal and Poultry Science, University of Guelph, Guelph, Ontario, Canada;
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11
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Molecular mechanisms of pharmaconutrients. J Surg Res 2009; 161:288-94. [PMID: 20080249 DOI: 10.1016/j.jss.2009.06.024] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2009] [Revised: 06/04/2009] [Accepted: 06/16/2009] [Indexed: 01/27/2023]
Abstract
Nutritional supplementation has become the standard of care for management of critically ill patients. Traditionally, nutritional support in this patient population was intended to replete substrate deficiencies secondary to stress-induced catabolism. Recognition of the influence of certain nutrients on the immune and inflammatory response of the critically ill has led to the evolution of more sophisticated nutritional strategies and concepts. Administration of immune-enhancing formulas supplemented with a combination of glutamine, arginine, omega-3 fatty acids (omega-3 FA), and nucleotides have been shown in most studies to reduce infectious outcomes. More recently, the separation of nutritional support from the provision of key nutrients has led to a further appreciation of the immunomodulatory and anti-inflammatory benefits of isolated nutrients, such as glutamine and antioxidants. The purpose of this article is to review the molecular mechanisms that are unique to each class of frequently utilized nutrients. A better understanding of the specific molecular targets of immunonutrients will facilitate application of more refined nutritional therapies in critically ill patients.
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12
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Zheng W, Kuhlicke J, Jäckel K, Eltzschig HK, Singh A, Sjöblom M, Riederer B, Weinhold C, Seidler U, Colgan SP, Karhausen J. Hypoxia inducible factor-1 (HIF-1)-mediated repression of cystic fibrosis transmembrane conductance regulator (CFTR) in the intestinal epithelium. FASEB J 2008; 23:204-13. [PMID: 18779379 DOI: 10.1096/fj.08-110221] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Diarrhea is widespread in intestinal diseases involving ischemia and/or hypoxia. Since hypoxia alters stimulated Cl(-) and water flux, we investigated the influence of such a physiologically and pathophysiologically important signal on expression of the cystic fibrosis transmembrane conductance regulator (CFTR). Located on the apical membrane, this cAMP-activated Cl(-) channel determines salt and fluid transport across mucosal surfaces. Our studies revealed depression of CFTR mRNA, protein, and function in hypoxic epithelia. Chromatin immunoprecipitation identified a previously unappreciated binding site for the hypoxia inducible factor-1 (HIF-1), and promoter studies established its relevance by loss of repression following point mutation. Consequently, HIF-1 overexpressing cells exhibited significantly reduced transport capacity in colorimetric Cl(-) efflux studies, altered short circuit measurements, and changes in transepithelial fluid movement. Whole-body hypoxia in wild-type mice resulted in significantly reduced small intestinal fluid and HCO(3)(-) secretory responses to forskolin. Experiments performed in Cftr(-/-) and Nkcc1(-/-) mice underlined the role of altered CFTR expression for these functional changes, and work in conditional Hif1a mutant mice verified HIF-1-dependent CFTR regulation in vivo. In summary, our study clarifies CFTR regulation and introduces the concept of a HIF-1-orchestrated response designed to regulate ion and fluid movement across hypoxic intestinal epithelia.
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Affiliation(s)
- Wen Zheng
- Abteilung Gastroenterologie, Hepatologie und Endokrinologie, Medizinische Hochschule Hannover, Hannover,
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McQuiggan M, Kozar R, Sailors RM, Ahn C, McKinley B, Moore F. Enteral glutamine during active shock resuscitation is safe and enhances tolerance of enteral feeding. JPEN J Parenter Enteral Nutr 2008; 32:28-35. [PMID: 18165444 DOI: 10.1177/014860710803200128] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND Feeding the hemodynamically unstable patient is increasingly practiced, yet few data exist on its safety. Because enteral glutamine is protective to the gut in experimental models of shock and improves clinical outcomes, it may benefit trauma patients undergoing shock resuscitation and improve tolerance if administered early. This pilot study aimed to evaluate gastrointestinal tolerance and safety of enteral feeding with glutamine, beginning during shock resuscitation in severely injured patients. METHODS In a prospective randomized trial, 20 patients were randomly assigned to either an enteral glutamine group (n = 10) or a control group (n = 10). Patients with severe trauma meeting standardized shock resuscitation criteria received enteral glutamine 0.5 g/kg/d during the first 24 hours of resuscitation and 10 days thereafter. Immune-enhancing diet began on postinjury day 1, with a target of 25 kcal/kg/d. Control patients received isonitrogenous whey powder plus immune-enhancing diet. Tolerance (vomiting, nasogastric output, diarrhea, and distention) was assessed throughout the study. RESULTS Glutamine was well tolerated and no adverse events occurred. Treated patients had significantly fewer instances of high nasogastric output (5 vs 23; p = .010), abdominal distention (3 vs 12; p = .021), and total instances of intolerance (8 vs 42; p = .011). Intensive care unit (ICU) and hospital length of stay were comparable. Control patients required supplemental parenteral nutrition (PN) to meet goals at day 7. CONCLUSIONS Enteral glutamine administered during active shock resuscitation and through the early postinjury period is safe and enhances gastrointestinal tolerance. A large clinical trial is warranted to determine if enteral glutamine administered to the hemodynamically unstable patient can reduce infectious morbidity and mortality.
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Affiliation(s)
- Margaret McQuiggan
- Department of Surgery, University of Texas Medical School Houston, Houston, Texas, USA.
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Na+-dependent neutral amino acid transporter ASCT2 is downregulated in seriously traumatized human intestinal epithelial cells. J Pediatr Gastroenterol Nutr 2008; 46:71-9. [PMID: 18162837 DOI: 10.1097/01.mpg.0000304457.22670.6f] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
OBJECTIVE Serious trauma to the body often is associated with changes in protein metabolism in multiple organs and tissues. Clinically, the catabolic response results in a generalized negative nitrogen balance. Nutrition support has been an important component of the care of seriously traumatized patients. However, during states of severe trauma, enterocyte transport function remains unclear. This study aims to quantitate the Na+-dependent neutral amino acid transport and expression of its transporter in traumatically injured Caco-2 cell lines. MATERIALS AND METHODS Transport and transporter of Na+-dependent neutral amino acid in Caco-2 cell lines were characterized. Then the cell lines were cultured under hypoxic, nutrient-deprived, and ischemic conditions for 1, 2, 4, and 6 hours. After severe trauma was performed, we investigated the transport of Na+-dependent neutral amino acids and the expression of transporter protein and mRNA in apical membrane vesicles. RESULTS Among the neutral amino acid transporters, only ASCT2 mRNA was amplified successfully. Under nutrient-deprived and ischemic conditions, transport of L-alanine and L-glutamine decreased significantly compared with control (P < 0.01), whereas hypoxia had no significant effect. The changes were associated with a decrease in maximum transport velocity without an influence on transport affinity. Expression of relative transporter proteins and mRNA decreased significantly compared with control (P < 0.01). CONCLUSIONS Na+-dependent neutral amino acid transport and its key transporter are differently regulated during state of traumatic injury. It may be of use to provide some strategies targeting the special nutrient requirements and transport capabilities of seriously traumatized patients.
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Kraus TA, Brimnes J, Muong C, Liu JH, Moran TM, Tappenden KA, Boros P, Mayer L. Induction of mucosal tolerance in Peyer's patch-deficient, ligated small bowel loops. J Clin Invest 2005; 115:2234-43. [PMID: 16041410 PMCID: PMC1177996 DOI: 10.1172/jci19102] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2003] [Accepted: 05/24/2005] [Indexed: 11/17/2022] Open
Abstract
To explore the requirement for M cells and the Peyer's patch (PP) in induction of oral tolerance and address the potential in vivo role of intestinal epithelial cells as nonprofessional APCs, we have attempted to induce tolerance in mice with ligated small bowel loops without M cells and Peyer's patches. A 2-centimeter section of vascularized small bowel was spliced away from the gut without disruption of the mesenteric attachments. We introduced OVA directly into the lumen of the loop prior to footpad immunization. By excising segments of bowel that contain PPs in some mice and segments without patches in others, we could study the necessity of the M cell and the underlying patch versus epithelial cells in induction of mucosal tolerance. We show that OVA-specific T cell proliferation and serum antibody responses are reduced in mice that have previously been given OVA both in PP-containing loops and in loops without patches. Furthermore, both high- and low-dose tolerance could be induced in the absence of PPs. Low-dose tolerance is associated with bystander suppression and requires IL-10, which indicates active suppression and the induction of regulatory cells. These data suggest that there is a critical role for components of the mucosal immune system other than PPs in antigen sampling and induction of oral tolerance.
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Affiliation(s)
- Thomas A Kraus
- Immunobiology Center, Mount Sinai School of Medicine, New York, New York 10029, USA
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Pan M, Meng Q, Choudry HA, Karinch AM, Lin C, Souba WW. Stimulation of intestinal glutamine absorption in chronic metabolic acidosis. Surgery 2004; 136:127-34. [PMID: 15300171 DOI: 10.1016/j.surg.2004.04.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
BACKGROUND Amino acid glutamine plays a central role in inter-organ nitrogen transfer in acidosis, a compensatory mechanism that is essential in maintaining acidbase balance. Intestinal glutamine absorption is a key exogenous glutamine source in maintaining glutamine homeostasis. The purpose of this in vivo study was to investigate the regulation of intestinal glutamine absorption during chronic metabolic acidosis. METHODS Metabolic acidosis in adult male Sprague-Dawley rats was induced by adding 1.5% NH4Cl to drinking water. [3H]-L-glutamine transport activity across brush border membrane vesicles and glutamine transporter ATB0 messenger RNA levels by relative reverse transcriptase-polymerase chain reaction were measured in rat jejunum. Data were analyzed by t test (P < .05). RESULTS Acidosis occurred as early as 1 day and was partially compensated by 7 days. Glutamine transport in brush border membrane vesicles was increased after 2 days of acidosis. Chronic acidosis (7 days) resulted in an 8-fold increase of glutamine transport activity. The glutamine transport maximal capacity (Vmax) was stimulated 5-fold, while the transport affinity (Km) was not affected by acidosis. Relative reverse transcriptase-polymerase chain reaction showed a 2.5-fold increase of glutamine transporter ATB0 messenger RNA levels. CONCLUSIONS Chronic metabolic acidosis stimulates intestinal glutamine absorption via a mechanism that involves an increase of functional membrane glutamine transporter units.
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Affiliation(s)
- Ming Pan
- Department of Surgery, The Milton S. Hershey Medical Center, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
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