1
|
Fan Y, Xue H, Li Z, Huo M, Gao H, Guan X. Exploiting the Achilles' heel of cancer: disrupting glutamine metabolism for effective cancer treatment. Front Pharmacol 2024; 15:1345522. [PMID: 38510646 PMCID: PMC10952006 DOI: 10.3389/fphar.2024.1345522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 02/23/2024] [Indexed: 03/22/2024] Open
Abstract
Cancer cells have adapted to rapid tumor growth and evade immune attack by reprogramming their metabolic pathways. Glutamine is an important nitrogen resource for synthesizing amino acids and nucleotides and an important carbon source in the tricarboxylic acid (TCA) cycle and lipid biosynthesis pathway. In this review, we summarize the significant role of glutamine metabolism in tumor development and highlight the vulnerabilities of targeting glutamine metabolism for effective therapy. In particular, we review the reported drugs targeting glutaminase and glutamine uptake for efficient cancer treatment. Moreover, we discuss the current clinical test about targeting glutamine metabolism and the prospective direction of drug development.
Collapse
Affiliation(s)
- Yuxin Fan
- Department of Clinical Laboratory Diagnostics, School of Medical Technology, Beihua University, Jilin City, China
- Department of Basic Medicine, Medical School, Taizhou University, Taizhou, Zhejiang Province, China
| | - Han Xue
- Department of Clinical Laboratory Diagnostics, School of Medical Technology, Beihua University, Jilin City, China
- Department of Basic Medicine, Medical School, Taizhou University, Taizhou, Zhejiang Province, China
| | - Zhimin Li
- Department of Clinical Laboratory Diagnostics, School of Medical Technology, Beihua University, Jilin City, China
- Department of Basic Medicine, Medical School, Taizhou University, Taizhou, Zhejiang Province, China
| | - Mingge Huo
- Department of Clinical Laboratory Diagnostics, School of Medical Technology, Beihua University, Jilin City, China
- Department of Basic Medicine, Medical School, Taizhou University, Taizhou, Zhejiang Province, China
| | - Hongxia Gao
- Department of Clinical Laboratory Diagnostics, School of Medical Technology, Beihua University, Jilin City, China
| | - Xingang Guan
- Department of Basic Medicine, Medical School, Taizhou University, Taizhou, Zhejiang Province, China
| |
Collapse
|
2
|
Arvans D, Chang C, Alshaikh A, Tesar C, Babnigg G, Wolfgeher D, Kron S, Antonopoulos D, Bashir M, Cham C, Musch M, Chang E, Joachimiak A, Hassan H. Sel1-like proteins and peptides are the major Oxalobacter formigenes-derived factors stimulating oxalate transport by human intestinal epithelial cells. Am J Physiol Cell Physiol 2023; 325:C344-C361. [PMID: 37125773 PMCID: PMC10393326 DOI: 10.1152/ajpcell.00466.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 04/10/2023] [Accepted: 04/13/2023] [Indexed: 05/02/2023]
Abstract
Kidney stones (KSs) are very common, excruciating, and associated with tremendous healthcare cost, chronic kidney disease (CKD), and kidney failure (KF). Most KSs are composed of calcium oxalate and small increases in urinary oxalate concentration significantly enhance the stone risk. Oxalate also potentially contributes to CKD progression, kidney disease-associated cardiovascular diseases, and poor renal allograft survival. This emphasizes the urgent need for plasma and urinary oxalate lowering therapies, which can be achieved by enhancing enteric oxalate secretion. We previously identified Oxalobacter formigenes (O. formigenes)-derived factors secreted in its culture-conditioned medium (CM), which stimulate oxalate transport by human intestinal Caco2-BBE (C2) cells and reduce urinary oxalate excretion in hyperoxaluric mice by enhancing colonic oxalate secretion. Given their remarkable therapeutic potential, we now identified Sel1-like proteins as the major O. formigenes-derived secreted factors using mass spectrometry and functional assays. Crystal structures for six proteins were determined to confirm structures and better understand functions. OxBSel1-14-derived small peptides P8 and P9 were identified as the major factors, with P8 + 9 closely recapitulating the CM's effects, acting through the oxalate transporters SLC26A2 and SLC26A6 and PKA activation. Besides C2 cells, P8 + 9 also stimulate oxalate transport by human ileal and colonic organoids, confirming that they work in human tissues. In conclusion, P8 and P9 peptides are identified as the major O. formigenes-derived secreted factors and they have significant therapeutic potential for hyperoxalemia, hyperoxaluria, and related disorders, impacting the outcomes of patients suffering from KSs, enteric hyperoxaluria, primary hyperoxaluria, CKD, KF, and renal transplant recipients.NEW & NOTEWORTHY We previously identified Oxalobacter formigenes-derived secreted factors stimulating oxalate transport by human intestinal epithelial cells in vitro and reducing urinary oxalate excretion in hyperoxaluric mice by enhancing colonic oxalate secretion. We now identified Sel1-like proteins and small peptides as the major secreted factors and they have significant therapeutic potential for hyperoxalemia and hyperoxaluria, impacting the outcomes of patients suffering from kidney stones, primary and secondary hyperoxaluria, chronic kidney disease, kidney failure, and renal transplant recipients.
Collapse
Affiliation(s)
- Donna Arvans
- University of Chicago Pritzker School of Medicine, Chicago, Illinois, United States
| | - Changsoo Chang
- Structural Biology Center, X-ray Science Division, Argonne National Laboratory, Lemont, Illinois, United States
| | - Altayeb Alshaikh
- University of Chicago Pritzker School of Medicine, Chicago, Illinois, United States
| | - Christine Tesar
- Structural Biology Center, X-ray Science Division, Argonne National Laboratory, Lemont, Illinois, United States
| | - Gyorgy Babnigg
- Biosciences Division, Argonne National Laboratory, Lemont, Illinois, United States
| | - Don Wolfgeher
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, Illinois, United States
| | - Stephen Kron
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, Illinois, United States
| | | | - Mohamed Bashir
- University of Chicago Pritzker School of Medicine, Chicago, Illinois, United States
| | - Candace Cham
- University of Chicago Pritzker School of Medicine, Chicago, Illinois, United States
| | - Mark Musch
- University of Chicago Pritzker School of Medicine, Chicago, Illinois, United States
| | - Eugene Chang
- University of Chicago Pritzker School of Medicine, Chicago, Illinois, United States
| | - Andrzej Joachimiak
- Structural Biology Center, X-ray Science Division, Argonne National Laboratory, Lemont, Illinois, United States
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, Illinois, United States
| | - Hatim Hassan
- University of Chicago Pritzker School of Medicine, Chicago, Illinois, United States
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, United States
| |
Collapse
|
3
|
Chiarello E, Di Nunzio M, Picone G, Antonelli G, Capozzi F, Bordoni A. Insight on Glucose and Fructose Absorption and Relevance in the Enterocyte Milieu. Nutrients 2022; 14:nu14030517. [PMID: 35276876 PMCID: PMC8839622 DOI: 10.3390/nu14030517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 01/10/2022] [Accepted: 01/20/2022] [Indexed: 11/16/2022] Open
Abstract
Although epidemiological studies indicate a strong correlation between high sugar intake and metabolic diseases, the biological mechanisms underlying this link are still controversial. To further examine the modification and crosstalk occurring in enterocyte metabolism during sugar absorption, in this study we evaluate the diffusion and intestinal metabolism of glucose, fructose and sucrose, which were supplemented in equimolar concentration to Caco-2 cells grown on polyester membrane inserts. At different time points after supplementation, changes in metabolite concentration were evaluated in the apical and basolateral chambers by nuclear magnetic resonance (NMR) and gas-chromatography (GC). Sucrose was only minimally hydrolyzed by Caco-2 cells. Upon supplementation, we observed a faster uptake of fructose than glucose, the pentose sugar being also faster catabolized. Monosaccharide absorption was concomitant to the synthesis/transport of other metabolites, which occurred differently in glucose and fructose supplemented cells. Our results confirm the prominent role of intestinal cells in fructose metabolism and clearance after absorption, representing a further step forward in the understanding of the role of dietary sugars. Future research, including targeted analysis on specific transporters/enzymes and the use of labeled substrates, will be helpful to confirm the present results and their interpretation.
Collapse
Affiliation(s)
- Elena Chiarello
- Department of Agri-Food Sciences and Technologies (DISTAL), University of Bologna, Piazza Goidanich 60, 47521 Cesena, Italy; (E.C.); (G.P.); (G.A.); (F.C.)
| | - Mattia Di Nunzio
- Department of Food, Environmental and Nutritional Sciences (Defens), University of Milan, via Celoria 2, 20133 Milan, Italy;
| | - Gianfranco Picone
- Department of Agri-Food Sciences and Technologies (DISTAL), University of Bologna, Piazza Goidanich 60, 47521 Cesena, Italy; (E.C.); (G.P.); (G.A.); (F.C.)
| | - Giorgia Antonelli
- Department of Agri-Food Sciences and Technologies (DISTAL), University of Bologna, Piazza Goidanich 60, 47521 Cesena, Italy; (E.C.); (G.P.); (G.A.); (F.C.)
| | - Francesco Capozzi
- Department of Agri-Food Sciences and Technologies (DISTAL), University of Bologna, Piazza Goidanich 60, 47521 Cesena, Italy; (E.C.); (G.P.); (G.A.); (F.C.)
- Interdepartmental Centre for Industrial Agri-Food Research (CIRI), University of Bologna, Piazza Goidanich 60, 47521 Cesena, Italy
| | - Alessandra Bordoni
- Department of Agri-Food Sciences and Technologies (DISTAL), University of Bologna, Piazza Goidanich 60, 47521 Cesena, Italy; (E.C.); (G.P.); (G.A.); (F.C.)
- Interdepartmental Centre for Industrial Agri-Food Research (CIRI), University of Bologna, Piazza Goidanich 60, 47521 Cesena, Italy
- Correspondence: ; Tel.: +39-0547-338955
| |
Collapse
|
4
|
Teixeira E, Silva C, Martel F. The role of the glutamine transporter ASCT2 in antineoplastic therapy. Cancer Chemother Pharmacol 2021; 87:447-464. [PMID: 33464409 DOI: 10.1007/s00280-020-04218-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 12/14/2020] [Indexed: 12/12/2022]
Abstract
Cancer cells are metabolically reprogrammed to support their high rates of proliferation, continuous growth, survival, invasion, metastasis, and resistance to cancer treatments. Among changes in cancer cell bioenergetics, the role of glutamine metabolism has been receiving increasing attention. Increased glutaminolysis in cancer cells is associated with increased expression of membrane transporters that mediate the cellular uptake of glutamine. ASCT2 (Alanine, Serine, Cysteine Transporter 2) is a Na+-dependent transmembrane transporter overexpressed in cancer cells and considered to be the primary transporter for glutamine in these cells. The possibility of inhibiting ASCT2 for antineoplastic therapy is currently under investigation. In this article, we will present the pharmacological agents currently known to act on ASCT2, which have been attracting attention in antineoplastic therapy research. We will also address the impact of ASCT2 inhibition on the prognosis of some cancers. We conclude that ASCT2 inhibition and combination of ASCT2 inhibitors with other anti-tumor therapies may be a promising antineoplastic strategy. However, more research is needed in this area.
Collapse
Affiliation(s)
- Estefânia Teixeira
- Department of Biomedicine, Unit of Biochemistry, Faculty of Medicine, University of Porto, Al Prof. Hernâni Monteiro, 4200-319, Porto, Portugal
| | - Cláudia Silva
- Department of Biomedicine, Unit of Biochemistry, Faculty of Medicine, University of Porto, Al Prof. Hernâni Monteiro, 4200-319, Porto, Portugal
- Instituto de Investigação E Inovação Em Saúde (i3S), University of Porto, Porto, Portugal
| | - Fátima Martel
- Department of Biomedicine, Unit of Biochemistry, Faculty of Medicine, University of Porto, Al Prof. Hernâni Monteiro, 4200-319, Porto, Portugal.
- Instituto de Investigação E Inovação Em Saúde (i3S), University of Porto, Porto, Portugal.
| |
Collapse
|
5
|
Soták M, Casselbrant A, Rath E, Zietek T, Strömstedt M, Adingupu DD, Karlsson D, Fritsch Fredin M, Ergang P, Pácha J, Batorsky A, Alpers CE, Börgeson E, Hansen PBL, Ericsson A, Björnson Granqvist A, Wallenius V, Fändriks L, Unwin RJ. Intestinal sodium/glucose cotransporter 3 expression is epithelial and downregulated in obesity. Life Sci 2020; 267:118974. [PMID: 33385407 DOI: 10.1016/j.lfs.2020.118974] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 12/11/2020] [Accepted: 12/20/2020] [Indexed: 12/12/2022]
Abstract
AIM We aimed to determine whether the sodium/glucose cotransporter family member SGLT3, a proposed glucose sensor, is expressed in the intestine and/or kidney, and if its expression is altered in mouse models of obesity and in humans before and after weight-loss surgery. MAIN METHODS We used in-situ hybridization and quantitative PCR to determine whether the Sglt3 isoforms 3a and 3b were expressed in the intestine and kidney of C57, leptin-deficient ob/ob, and diabetic BTBR ob/ob mice. Western blotting and immunohistochemistry were also used to assess SGLT3 protein levels in jejunal biopsies from obese patients before and after weight-loss Roux-en-Y gastric bypass surgery (RYGB), and in lean healthy controls. KEY FINDINGS Sglt3a/3b mRNA was detected in the small intestine (duodenum, jejunum and ileum), but not in the large intestine or kidneys of mice. Both isoforms were detected in epithelial cells (confirmed using intestinal organoids). Expression of Sglt3a/3b mRNA in duodenum and jejunum was significantly lower in ob/ob and BTBR ob/ob mice than in normal-weight littermates. Jejunal SGLT3 protein levels in aged obese patients before RYGB were lower than in lean individuals, but substantially upregulated 6 months post-RYGB. SIGNIFICANCE Our study shows that Sglt3a/3b is expressed primarily in epithelial cells of the small intestine in mice. Furthermore, we observed an association between intestinal mRNA Sglt3a/3b expression and obesity in mice, and between jejunal SGLT3 protein levels and obesity in humans. Further studies are required to determine the possible role of SGLT3 in obesity.
Collapse
Affiliation(s)
- Matúš Soták
- Bioscience, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden; Department of Molecular and Clinical Medicine, Wallenberg Laboratory, Institute of Medicine, University of Gothenburg, Sweden; Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Sweden.
| | - Anna Casselbrant
- Department of Surgery, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Eva Rath
- Chair of Nutrition and Immunology, Technische Universität München, Freising, Germany
| | - Tamara Zietek
- Department of Nutritional Physiology, Technische Universität München, Freising, Germany
| | - Maria Strömstedt
- Bioscience, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Damilola D Adingupu
- Bioscience, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Daniel Karlsson
- Bioscience, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Maria Fritsch Fredin
- Bioscience, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Peter Ergang
- Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Jiří Pácha
- Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Anna Batorsky
- Department of Pathology, University of Washington School of Medicine, Seattle, USA
| | - Charles E Alpers
- Department of Pathology, University of Washington School of Medicine, Seattle, USA
| | - Emma Börgeson
- Department of Molecular and Clinical Medicine, Wallenberg Laboratory, Institute of Medicine, University of Gothenburg, Sweden; Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Sweden; Department of Clinical Physiology, Sahlgrenska University Hospital, Sweden
| | - Pernille B L Hansen
- Bioscience, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden; Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Sweden
| | - Anette Ericsson
- Bioscience, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Anna Björnson Granqvist
- Bioscience, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Ville Wallenius
- Department of Surgery, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Lars Fändriks
- Department of Surgery, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Robert J Unwin
- Bioscience, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden; Department of Renal Medicine, Division of Medicine, University College London, UK
| |
Collapse
|
6
|
Selle P, Liu SY. The Relevance of Starch and Protein Digestive Dynamics in Poultry. J APPL POULTRY RES 2019. [DOI: 10.3382/japr/pfy026] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
7
|
Idrizaj E, Garella R, Squecco R, Baccari MC. Adipocytes-released Peptides Involved in the Control of Gastrointestinal Motility. Curr Protein Pept Sci 2019; 20:614-629. [PMID: 30663565 DOI: 10.2174/1389203720666190121115356] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 01/07/2019] [Accepted: 01/09/2019] [Indexed: 12/18/2022]
Abstract
The present review focuses on adipocytes-released peptides known to be involved in the control of gastrointestinal motility, acting both centrally and peripherally. Thus, four peptides have been taken into account: leptin, adiponectin, nesfatin-1, and apelin. The discussion of the related physiological or pathophysiological roles, based on the most recent findings, is intended to underlie the close interactions among adipose tissue, central nervous system, and gastrointestinal tract. The better understanding of this complex network, as gastrointestinal motor responses represent peripheral signals involved in the regulation of food intake through the gut-brain axis, may also furnish a cue for the development of either novel therapeutic approaches in the treatment of obesity and eating disorders or potential diagnostic tools.
Collapse
Affiliation(s)
- Eglantina Idrizaj
- Department of Experimental and Clinical Medicine, Section of Physiological Sciences, University of Florence, Florence, Italy
| | - Rachele Garella
- Department of Experimental and Clinical Medicine, Section of Physiological Sciences, University of Florence, Florence, Italy
| | - Roberta Squecco
- Department of Experimental and Clinical Medicine, Section of Physiological Sciences, University of Florence, Florence, Italy
| | - Maria Caterina Baccari
- Department of Experimental and Clinical Medicine, Section of Physiological Sciences, University of Florence, Florence, Italy
| |
Collapse
|
8
|
Xylobiose Prevents High-Fat Diet Induced Mice Obesity by Suppressing Mesenteric Fat Deposition and Metabolic Dysregulation. Molecules 2018; 23:molecules23030705. [PMID: 29558403 PMCID: PMC6017709 DOI: 10.3390/molecules23030705] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 03/09/2018] [Accepted: 03/16/2018] [Indexed: 12/13/2022] Open
Abstract
Obesity is a public concern and is responsible for various metabolic diseases. Xylobiose (XB), an alternative sweetener, is a major component of xylo-oligosaccharide. The purpose of this study was to investigate the effects of XB on obesity and its associated metabolic changes in related organs. For these studies, mice received a 60% high-fat diet supplemented with 15% d-xylose, 10% XB, or 15% XB as part of the total sucrose content of the diet for ten weeks. Body weight, fat and liver weights, fasting blood glucose, and blood lipids levels were significantly reduced with XB supplementation. Levels of leptin and adipokine were also improved and lipogenic and adipogenic genes in mesenteric fat and liver were down-regulated with XB supplementation. Furthermore, pro-inflammatory cytokines, fatty acid uptake, lipolysis, and β-oxidation-related gene expression levels in mesenteric fat were down-regulated with XB supplementation. Thus, XB exhibited therapeutic potential for treating obesity which involved suppression of fat deposition and obesity-related metabolic disorders.
Collapse
|
9
|
Torres-Villarreal D, Camacho A, Milagro FI, Ortiz-Lopez R, de la Garza AL. Quercetin-3-O-glucoside Improves Glucose Tolerance in Rats and Decreases Intestinal Sugar Uptake in Caco-2 Cells. Nat Prod Commun 2017. [DOI: 10.1177/1934578x1701201112] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Flavonoid-rich foods intake has been associated with lower risk of non-communicable chronic diseases. Quercetin is the most abundant flavonoid in nature (fruits, vegetables, leaves and grains) as well as the most consumed flavonol. This study aims to investigate the potential effects of its conjugated form quercetin-3- O-glucoside (or isoquercetin) on glucose metabolism in rats and Caco-2 cells. To analyse the effect of quercetin-3- O-glucoside on postprandial hyperglycemia, an oral glucose tolerance test (OGTT) was conducted in Wistar rats. Additionally, Caco-2 cells were used to determine the effect of quercetin-3- O-glucoside (30 to 60 μM) on mRNA expression of genes involved in glucose uptake by RT-PCR. Thereby, in vivo studies demonstrated that quercetin-3- O-glucoside decreased blood glucose levels evaluated by OGTT in rats. Furthermore, in the presence of Na+, quercetin-3- O-glucoside inhibited methylglucoside (MG) uptake in enterocytes and both sodium dependent glucose transporter-1 (SGLT1)- and glucose transporter-2 (GLUT2)-mediated glucose uptake were downregulated in Caco-2 cells incubated with quercetin-3- O-glucoside. In summary, our results show that quercetin-3- O-glucoside improves postprandial glycemic control in rats and reduces sugar uptake in Caco-2 cells, possible by decreasing the expression of glucose transporters (SGLT1 and GLUT2) according to the results obtained through RT-PCR.
Collapse
Affiliation(s)
- Denys Torres-Villarreal
- Universidad Autonoma de Nuevo Leon, Facultad de Salud Pública y Nutrición, Monterrey, Nuevo León, México
| | - Alberto Camacho
- Universidad Autonoma de Nuevo Leon, Facultad de Medicina, Monterrey, Nuevo León, México
- Universidad Autonoma de Nuevo Leon, Unidad de Neurociencias, Centro de Investigación y Desarrollo en Ciencias de la Salud, Monterrey, Nuevo León, México
| | - Fermín I. Milagro
- Department of Nutrition, Food Science and Physiology, Centre for Nutrition Research, University of Navarra, Pamplona, Spain
| | - Rocío Ortiz-Lopez
- Escuela de Medicina, Tecnológico de Monterrey, Monterrey, Nuevo León, México
| | - Ana Laura de la Garza
- Universidad Autonoma de Nuevo Leon, Facultad de Salud Pública y Nutrición, Monterrey, Nuevo León, México
- Universidad Autonoma de Nuevo Leon, Unidad de Nutrición, Centro de Investigación y Desarrollo en Ciencias de la Salud, Monterrey, Nuevo León, México
| |
Collapse
|
10
|
Nutrient Transporter Expression in the Jejunum in Relation to Body Mass Index in Patients Undergoing Bariatric Surgery. Nutrients 2016; 8:nu8110683. [PMID: 27801863 PMCID: PMC5133071 DOI: 10.3390/nu8110683] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Revised: 10/11/2016] [Accepted: 10/26/2016] [Indexed: 12/20/2022] Open
Abstract
Nutrient tranters (NT) facilitate nutrient absorption and contribute to the regulation of circulating nutrients. In this cross-sectional study, we determined the associations between the level of obesity; mRNA abundance for NTs; and serum concentrations of amino acids, short-chain fatty acids, and glucose in patients with morbid obesity undergoing a Roux-en-Y gastric bypass. Proximal jejunal samples were obtained at the time of surgery from 42 patients (90% female, age = 42.6 ± 11.9 years, pre-operative body mass index (BMI) = 55.5 ± 11.3 kg/m²) undergoing a Roux-en-Y gastric bypass. RNA was extracted from the jejunal mucosa and quantitative real-time-PCR was performed for the NTs studied. BMI negatively correlated with jejunal mRNA abundance of the amino acid NTs TauT (r = -0.625, p < 0.0001), ASCT2 (r = -0.320, p = 0.039), LAT1 (r = -0.304, p = 0.05). BMI positively correlated with jejunal mRNA abundance of the lactate/short-chain fatty acid NT SMCT1 (r = 0.543, p = 0.0002). Serum concentrations of the short-chain fatty acids, butyric, valeric, and isocaproic acid correlated positively with BMI (n = 30) (r = 0.45, r = 0.44, r = 0.36, p ≤ 0.05; respectively). Lower jejunal mRNA abundance for the amino acid NTs TauT, ASCT2, and LAT1 could protect against further obesity-related elevations in circulating amino acids. The positive correlation between BMI and the jejunal mRNA abundance of the high-affinity short-chain fatty acid/monocarboxylate transporter SMCT1 is intriguing and requires further investigation.
Collapse
|
11
|
Mößeler A, Herrmann J, Burmester M, Breves G, Kamphues J. Changes in small intestinal morphometry and electrogenic nutrient transport in young pigs with pancreatic exocrine insufficiency. J Anim Sci 2016. [DOI: 10.2527/jas.2015-9724] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
12
|
López-Yoldi M, Castilla-Madrigal R, Lostao MP, Barber A, Prieto J, Martínez JA, Bustos M, Moreno-Aliaga MJ. Cardiotrophin-1 decreases intestinal sugar uptake in mice and in Caco-2 cells. Acta Physiol (Oxf) 2016; 217:217-26. [PMID: 26972986 DOI: 10.1111/apha.12674] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Revised: 10/12/2015] [Accepted: 03/04/2016] [Indexed: 12/15/2022]
Abstract
AIM Cardiotrophin-1 (CT-1) is a member of the IL-6 family of cytokines with a key role in glucose and lipid metabolism. In the current investigation, we examined the in vivo and in vitro effects of CT-1 treatment on intestinal sugar absorption in different experimental models. METHODS rCT-1 effects on α-Methyl-D-glucoside uptake were assessed in everted intestinal rings from wild-type and CT-1(-/-) mice and in Caco-2 cells. rCT-1 actions on SGLT-1 expression in brush border membrane vesicles and the identification of the potential signalling pathways involved were determined by Western blot. RESULTS In vivo administration (0.2 mg kg(-1) ) of rCT-1 caused a significant decrease on α-Methyl-D-glucoside uptake in everted intestinal rings from wild-type and CT-1(-/-) mice after short-term and long-term treatments. Similarly, in vitro treatment (1-50 ng mL(-1) ) with rCT-1 reduced α-Methyl-D-glucoside uptake in everted intestinal rings. In Caco-2 cells, rCT-1 treatment (20 ng mL(-1) , 1 and 24 h) lowered apical uptake of α-Methyl-D-glucoside in parallel with a decrease on SGLT-1 protein expression. rCT-1 promoted the phosphorylation of STAT-3 after 5 and 15 min treatment, but inhibited the activation by phosphorylation of AMPK after 30 and 60 min. Interestingly, pre-treatment with the JAK/STAT inhibitor (AG490) and with the AMPK activator (AICAR) reversed the inhibitory effects of rCT-1 on α-Methyl-D-glucoside uptake. AICAR also prevented the inhibition of SGLT-1 observed in rCT-1-treated cells. CONCLUSIONS CT-1 inhibits intestinal sugar absorption by the reduction of SGLT-1 levels through the AMPK pathway, which could also contribute to explain the hypoglycaemic and anti-obesity properties of CT-1.
Collapse
Affiliation(s)
- M. López-Yoldi
- Department of Nutrition, Food Science and Physiology; University of Navarra; Pamplona Navarra Spain
- Centre for Nutrition Research; University of Navarra; Pamplona Navarra Spain
| | - R. Castilla-Madrigal
- Department of Nutrition, Food Science and Physiology; University of Navarra; Pamplona Navarra Spain
- Centre for Nutrition Research; University of Navarra; Pamplona Navarra Spain
| | - M. P. Lostao
- Department of Nutrition, Food Science and Physiology; University of Navarra; Pamplona Navarra Spain
- Centre for Nutrition Research; University of Navarra; Pamplona Navarra Spain
- IdiSNA; Navarra Institute for Health Research; Pamplona Spain
| | - A. Barber
- Department of Nutrition, Food Science and Physiology; University of Navarra; Pamplona Navarra Spain
| | - J. Prieto
- Department of Gene Therapy and Hepatology; CIMA; University of Navarra; Pamplona Navarra Spain
- CIBERehd; Institute of Health Carlos III; Madrid Spain
| | - J. A. Martínez
- Department of Nutrition, Food Science and Physiology; University of Navarra; Pamplona Navarra Spain
- Centre for Nutrition Research; University of Navarra; Pamplona Navarra Spain
- IdiSNA; Navarra Institute for Health Research; Pamplona Spain
- CIBERobn; Physiopathology of Obesity and Nutrition; Institute of Health Carlos III; Madrid Spain
| | - M. Bustos
- Department of Gene Therapy and Hepatology; CIMA; University of Navarra; Pamplona Navarra Spain
| | - M. J. Moreno-Aliaga
- Department of Nutrition, Food Science and Physiology; University of Navarra; Pamplona Navarra Spain
- Centre for Nutrition Research; University of Navarra; Pamplona Navarra Spain
- IdiSNA; Navarra Institute for Health Research; Pamplona Spain
- CIBERobn; Physiopathology of Obesity and Nutrition; Institute of Health Carlos III; Madrid Spain
| |
Collapse
|
13
|
Fanjul C, Barrenetxe J, Lostao MP, Ducroc R. Modulation of intestinal L-glutamate transport by luminal leptin. J Physiol Biochem 2015; 71:311-7. [DOI: 10.1007/s13105-015-0414-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 04/21/2015] [Indexed: 12/18/2022]
|
14
|
Fanjul C, Barrenetxe J, De Pablo-Maiso L, Lostao MP. In vivo regulation of intestinal absorption of amino acids by leptin. J Endocrinol 2015; 224:17-23. [PMID: 25349247 DOI: 10.1530/joe-14-0453] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Leptin is secreted by the gastric mucosa and is able to reach the intestinal lumen and bind to its receptors located in the apical membranes of enterocytes. We have previously demonstrated that apical leptin inhibits uptake of amino acids in rat intestine in vitro and in Caco-2 cells. The aim of the present work was to investigate the effect of leptin on absorption of amino acids using in vivo techniques, which generate situations closer to physiological conditions. In vivo intestinal absorption of amino acids in rats was measured by isolating a jejunal loop and using the single-pass perfusion system. Disappearance of glutamine (Gln), proline (Pro), and β-alanine (β-Ala) from the perfusate, in the absence or presence of leptin, was measured using a radioactivity method. Luminal leptin (25 nM) inhibited the absorption of 2 mM Pro, 5 mM β-Ala, and 5 mM Gln by approximately 45% after 5-15 min; the effect remained constant until the end of the experiment (80 min) and was rapidly and completely reversed when leptin was removed from the perfusion medium. Moreover, leptin was able to regulate the absorption of galactose and Gln in the same animal, indicating a direct action of the hormone on the specific transporters implicated in the uptake of each nutrient. The results of the present work indicate that luminal leptin decreases absorption of amino acids in vivo in a short-term manner and in a reversible way. These results, together with our previous findings, make it evident that leptin can be considered as a hormone which provides the intestine with a control mechanism to handle absorption of nutrients.
Collapse
Affiliation(s)
- Carmen Fanjul
- Department of NutritionFood Science and Physiology, University of Navarra, 31008 Pamplona, Spain
| | - Jaione Barrenetxe
- Department of NutritionFood Science and Physiology, University of Navarra, 31008 Pamplona, Spain
| | - Lorena De Pablo-Maiso
- Department of NutritionFood Science and Physiology, University of Navarra, 31008 Pamplona, Spain
| | - María Pilar Lostao
- Department of NutritionFood Science and Physiology, University of Navarra, 31008 Pamplona, Spain
| |
Collapse
|
15
|
Sáinz N, Barrenetxe J, Moreno-Aliaga MJ, Martínez JA. Leptin resistance and diet-induced obesity: central and peripheral actions of leptin. Metabolism 2015; 64:35-46. [PMID: 25497342 DOI: 10.1016/j.metabol.2014.10.015] [Citation(s) in RCA: 290] [Impact Index Per Article: 32.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 10/15/2014] [Accepted: 10/20/2014] [Indexed: 12/15/2022]
Abstract
Obesity is a chronic disease that represents one of the most serious global health burdens associated to an excess of body fat resulting from an imbalance between energy intake and expenditure, which is regulated by environmental and genetic interactions. The adipose-derived hormone leptin acts via a specific receptor in the brain to regulate energy balance and body weight, although this protein can also elicit a myriad of actions in peripheral tissues. Obese individuals, rather than be leptin deficient, have in most cases, high levels of circulating leptin. The failure of these high levels to control body weight suggests the presence of a resistance process to the hormone that could be partly responsible of disturbances on body weight regulation. Furthermore, leptin resistance can impair physiological peripheral functions of leptin such as lipid and carbohydrate metabolism and nutrient intestinal utilization. The present document summarizes those findings regarding leptin resistance development and the role of this hormone in the development and maintenance of an obese state. Thus, we focused on the effect of the impaired leptin action on adipose tissue, liver, skeletal muscle and intestinal function and the accompanying relationships with diet-induced obesity. The involvement of some inflammatory mediators implicated in the development of obesity and their roles in leptin resistance development are also discussed.
Collapse
Affiliation(s)
- Neira Sáinz
- Department of Nutrition, Food Sciences and Physiology, University of Navarra, C/Irunlarrea 1, 31008 Pamplona, Spain
| | - Jaione Barrenetxe
- Department of Nutrition, Food Sciences and Physiology, University of Navarra, C/Irunlarrea 1, 31008 Pamplona, Spain
| | - María J Moreno-Aliaga
- Department of Nutrition, Food Sciences and Physiology, University of Navarra, C/Irunlarrea 1, 31008 Pamplona, Spain; CIBER Fisiopatología de la Obesidad y la Nutrición (CIBERobn), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - José Alfredo Martínez
- Department of Nutrition, Food Sciences and Physiology, University of Navarra, C/Irunlarrea 1, 31008 Pamplona, Spain; CIBER Fisiopatología de la Obesidad y la Nutrición (CIBERobn), Instituto de Salud Carlos III, 28029 Madrid, Spain.
| |
Collapse
|
16
|
de la Garza AL, Etxeberria U, Lostao MP, San Román B, Barrenetxe J, Martínez JA, Milagro FI. Helichrysum and grapefruit extracts inhibit carbohydrate digestion and absorption, improving postprandial glucose levels and hyperinsulinemia in rats. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2013; 61:12012-12019. [PMID: 24261475 DOI: 10.1021/jf4021569] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Several plant extracts rich in flavonoids have been reported to improve hyperglycemia by inhibiting digestive enzyme activities and SGLT1-mediated glucose uptake. In this study, helichrysum ( Helichrysum italicum ) and grapefruit ( Citrus × paradisi ) extracts inhibited in vitro enzyme activities. The helichrysum extract showed higher inhibitory activity of α-glucosidase (IC50 = 0.19 mg/mL) than α-amylase (IC50 = 0.83 mg/mL), whereas the grapefruit extract presented similar α-amylase and α-glucosidase inhibitory activities (IC50 = 0.42 mg/mL and IC50 = 0.41 mg/mL, respectively). Both extracts reduced maltose digestion in noneverted intestinal sacs (57% with helichrysum and 46% with grapefruit). Likewise, both extracts inhibited SGLT1-mediated methylglucoside uptake in Caco-2 cells in the presence of Na(+) (56% of inhibition with helichrysum and 54% with grapefruit). In vivo studies demonstrated that helichrysum decreased blood glucose levels after an oral maltose tolerance test (OMTT), and both extracts reduced postprandial glucose levels after the oral starch tolerance test (OSTT). Finally, both extracts improved hyperinsulinemia (31% with helichrysum and 50% with grapefruit) and HOMA index (47% with helichrysum and 54% with grapefruit) in a dietary model of insulin resistance in rats. In summary, helichrysum and grapefruit extracts improve postprandial glycemic control in rats, possibly by inhibiting α-glucosidase and α-amylase enzyme activities and decreasing SGLT1-mediated glucose uptake.
Collapse
Affiliation(s)
- Ana Laura de la Garza
- Department of Nutrition, Food Science and Physiology, University of Navarra , Pamplona, Spain
| | | | | | | | | | | | | |
Collapse
|
17
|
El-Zein O, Kreydiyyeh SI. Leptin inhibits glucose intestinal absorption via PKC, p38MAPK, PI3K and MEK/ERK. PLoS One 2013; 8:e83360. [PMID: 24340098 PMCID: PMC3858357 DOI: 10.1371/journal.pone.0083360] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 11/11/2013] [Indexed: 11/25/2022] Open
Abstract
The role of leptin in controlling food intake and body weight is well recognized, but whether this is achieved by modulating nutrient absorption is still a controversial issue. The aim of this work was to investigate the direct effect of luminal leptin on glucose intestinal absorption and elucidate for the first time its signaling pathway. Fully differentiated Caco-2 cells grown on transwell filters were used for glucose transport studies. Leptin caused a significant reduction in glucose absorption. Individual and simultaneous inhibition of ERK, p38MAPK, PI3K or PKC abrogated completely the inhibitory effect of leptin. Activating PKC, lead to a stimulatory effect that appeared only when ERK, p38MAPK, or PI3K was inactive. Moreover, leptin increased the phosphorylation of ERK, Akt and p38MAPK. This increase changed into a decrease when p38MAPK and PKC were inactivated individually. Inhibiting ERK maintained the leptin-induced up-regulation of p-Akt and p-p38MAPK while inhibiting PI3K reduced the level of p-ERK and p-Akt but maintained the increase in p-p38MAPK. These results suggest that leptin reduces glucose absorption by activating PKC. Although the latter modulates glucose absorption via a stimulatory and an inhibitory pathway, only the latter is involved in leptin’s action. Active PKC leads to a sequential activation of p38MAPK, PI3K and ERK which exerts an inhibitory effect on glucose absorption. The results reveal a modulatory role of leptin in nutrient absorption in addition to its known satiety inducing effect.
Collapse
Affiliation(s)
- Ola El-Zein
- Department of Biology, American University of Beirut, Beirut, Lebanon
| | | |
Collapse
|
18
|
Barrenetxe J, Sánchez O, Barber A, Gascón S, Rodríguez-Yoldi MJ, Lostao MP. TNFα regulates sugar transporters in the human intestinal epithelial cell line Caco-2. Cytokine 2013; 64:181-7. [PMID: 23910014 DOI: 10.1016/j.cyto.2013.07.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Revised: 06/10/2013] [Accepted: 07/02/2013] [Indexed: 01/25/2023]
Abstract
PURPOSE During intestinal inflammation TNFα levels are increased and as a consequence malabsorption of nutrients may occur. We have previously demonstrated that TNFα inhibits galactose, fructose and leucine intestinal absorption in animal models. In continuation with our work, the purpose of the present study was to investigate in the human intestinal epithelial cell line Caco-2, the effect of TNFα on sugar transport and to identify the intracellular mechanisms involved. METHODS Caco-2 cells were grown on culture plates and pre-incubated during different periods with various TNFα concentrations before measuring the apical uptake of galactose, α-methyl-glucoside (MG) or fructose for 15 min. To elucidate the signaling pathway implicated, cells were pre-incubated for 30min with the PKA inhibitor H-89 or the PKC inhibitor chelerythrine, before measuring the sugar uptake. The expression in the apical membrane of the transporters implicated in the sugars uptake process (SGLT1 and GLUT5) was determined by Western blot. RESULTS TNFα inhibited 0.1mM MG uptake after pre-incubation of the cells for 6-48h with the cytokine and in the absence of cytokine pre-incubation. In contrast, 5mM fructose uptake was stimulated by TNFα only after long pre-incubation times (24 and 48 h). These effects were mediated by the binding of the cytokine to its specific receptor TNFR1, present in the apical membrane of the Caco-2 cells. Analysis of the expression of the MG and fructose transporters at the brush border membrane of the cells, after 24h pre-incubation with the cytokine, revealed decrease on the amount of SGLT1 and increase on the amount of GLUT5 proteins. Short-term inhibition of MG transport by TNFα was not modified by H-89 but was blocked by chelerythrine. CONCLUSIONS SGLT1 and GLUT5 expression in the plasma membrane is regulated by TNFα in the human epithelial cell line Caco-2 cells, leading to alteration on sugars transport, suggesting that TNFα could be considered as a physiological local regulator of nutrients absorption in response to an intestinal inflammatory status.
Collapse
Affiliation(s)
- Jaione Barrenetxe
- Department of Nutrition, Food Science and Physiology, University of Navarra, Pamplona 31008, Spain.
| | | | | | | | | | | |
Collapse
|
19
|
Basal leptin regulates amino acid uptake in polarized Caco-2 cells. J Physiol Biochem 2013; 69:507-12. [DOI: 10.1007/s13105-013-0239-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2012] [Accepted: 01/13/2013] [Indexed: 12/31/2022]
|
20
|
Affiliation(s)
- P. B. Persson and
- Institute of Vegetative Physiology; Charité-Universitaetsmedizin Berlin; Berlin; Germany
| | - A. Bondke Persson
- Institute of Vegetative Physiology; Charité-Universitaetsmedizin Berlin; Berlin; Germany
| |
Collapse
|
21
|
Abstract
PURPOSE OF REVIEW We consider recent advances in epithelial amino acid transport physiology and our understanding of the functioning of amino acid transporters as sensors, as well as carriers, of tissue nutrient supplies. RECENT FINDINGS Gut hormones (e.g. leptin) may regulate intestinal amino acid transporter activity by a variety of mechanisms, although the overall functional significance of such regulation is not yet fully understood. Important functional interactions between amino acid transporters and nutrient-signalling pathways which regulate metabolism [e.g. the mammalian target of rapamycin (mTOR)C1 pathway which promotes cell growth] have been revealed in recent studies. Amino acid transporters on endosomal (e.g. lysosomal) membranes may be of unexpected significance as intracellular nutrient sensors. It is also now evident that certain amino acid transporters may have dual receptor-transporter functions and act as 'transceptors' to sense amino acid availability upstream of signal pathways. SUMMARY Increased knowledge on the timescale of the amino acid sensor-signal-effector process(es) should help in the optimization of protein-feeding regimes to gain maximum anabolic effect. New opportunities for nutritional therapy include targeting of amino acid transceptors to promote protein-anabolic signals and mechanisms up-regulating amino acid transporter expression to improve absorptive capacity for nutrients.
Collapse
Affiliation(s)
- Nadège Poncet
- Division of Cell Signalling & Immunology, College of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, UK
| | | |
Collapse
|
22
|
Fuente-Martín E, García-Cáceres C, Granado M, de Ceballos ML, Sánchez-Garrido MÁ, Sarman B, Liu ZW, Dietrich MO, Tena-Sempere M, Argente-Arizón P, Díaz F, Argente J, Horvath TL, Chowen JA. Leptin regulates glutamate and glucose transporters in hypothalamic astrocytes. J Clin Invest 2012; 122:3900-13. [PMID: 23064363 DOI: 10.1172/jci64102] [Citation(s) in RCA: 155] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Accepted: 08/27/2012] [Indexed: 01/08/2023] Open
Abstract
Glial cells perform critical functions that alter the metabolism and activity of neurons, and there is increasing interest in their role in appetite and energy balance. Leptin, a key regulator of appetite and metabolism, has previously been reported to influence glial structural proteins and morphology. Here, we demonstrate that metabolic status and leptin also modify astrocyte-specific glutamate and glucose transporters, indicating that metabolic signals influence synaptic efficacy and glucose uptake and, ultimately, neuronal function. We found that basal and glucose-stimulated electrical activity of hypothalamic proopiomelanocortin (POMC) neurons in mice were altered in the offspring of mothers fed a high-fat diet. In adulthood, increased body weight and fasting also altered the expression of glucose and glutamate transporters. These results demonstrate that whole-organism metabolism alters hypothalamic glial cell activity and suggest that these cells play an important role in the pathology of obesity.
Collapse
Affiliation(s)
- Esther Fuente-Martín
- Hospital Infantil Universitario Niño Jesús, Department of Endocrinology, Instituto de Investigación La Princesa, Madrid, Spain
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Joffin N, Niang F, Forest C, Jaubert AM. Is there NO help for leptin? Biochimie 2012; 94:2104-10. [PMID: 22750650 DOI: 10.1016/j.biochi.2012.06.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2012] [Accepted: 06/15/2012] [Indexed: 01/14/2023]
Abstract
Since the initial identification of leptin as the product of the ob gene in 1994, the signaling pathways by which this hormone alters cell physiology have been the subject of extensive investigations. The fact that leptin can induce nitric oxide (NO) production was first demonstrated in studies of the pituitary gland and pancreatic islets. A large number of additional studies further showed that this adipokine stimulates NO synthesis in multiple tissues. This review article discusses the role of leptin in NO production and its pathophysiological consequences. The role of this gaseous messenger in cell physiology depends on the cell type, the concentration of NO and the duration of exposure. It can be either a potent oxidant or a protector of cell integrity against the formation of reactive oxygen species. Leptin plays two opposing roles on arterial pressure. It exerts a hypertensive effect due to sympathetic activation and a vasorelaxant effect due to NO production. This adipokine acts via NO to produce pro-inflammatory factors in cartilage pathology, potentially contributing to an increased risk for osteoarthritis. Another well-documented role of leptin-induced NO, acting either directly or via the hypothalamus, concerns lipid metabolism in muscle and adipose tissue. In adipocytes, the direct and rapid action of leptin is to activate the nitric oxide synthase III, which favors lipolysis. In contrast, in the long-term, leptin reduces lipolysis. However, both in the short-term and in the long-term, glyceroneogenesis and its key enzyme, the cytosolic phosphoenolpyruvatecarboxykinase (PEPCK-C), are down-regulated by the adipokine, thus favoring fatty acid release. Hence, leptin-induced NO production plays a crucial role in fatty acid metabolism in adipose tissue. The resulting effects are to prevent lipid storage and to improve energy expenditure, with possible improvements of the obese state and its associated diseases.
Collapse
Affiliation(s)
- Nolwenn Joffin
- Institut National de la Santé et de la Recherche Médicale UMR-S 747, Université Paris Descartes, Pharmacologie Toxicologie et Signalisation Cellulaire, 45 rue des Saints Pères, 75006 Paris, France
| | | | | | | |
Collapse
|