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Arthur S, Singh S, Sundaram U. Correction: Cyclooxygenase pathway mediates the inhibition of Na-glutamine co-transporter B0AT1 in rabbit villus cells during chronic intestinal inflammation. PLoS One 2023; 18:e0294387. [PMID: 37943850 PMCID: PMC10635497 DOI: 10.1371/journal.pone.0294387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2023] Open
Abstract
[This corrects the article DOI: 10.1371/journal.pone.0203552.].
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Taurino G, Chiu M, Bianchi MG, Griffini E, Bussolati O. The SLC38A5/SNAT5 amino acid transporter: from pathophysiology to pro-cancer roles in the tumor microenvironment. Am J Physiol Cell Physiol 2023; 325:C550-C562. [PMID: 37458433 DOI: 10.1152/ajpcell.00169.2023] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 07/11/2023] [Accepted: 07/11/2023] [Indexed: 08/09/2023]
Abstract
SLC38A5/SNAT5 is a system N transporter that can mediate net inward or outward transmembrane fluxes of neutral amino acids coupled with Na+ (symport) and H+ (antiport). Its preferential substrates are not only amino acids with side chains containing amide (glutamine and asparagine) or imidazole (histidine) groups, but also serine, glycine, and alanine are transported by the carrier. Expressed in the pancreas, intestinal tract, brain, liver, bone marrow, and placenta, it is regulated at mRNA and protein levels by mTORC1 and WNT/β-catenin pathways, and it is sensitive to pH, nutritional stress, inflammation, and hypoxia. SNAT5 expression has been found to be altered in pathological conditions such as chronic inflammatory diseases, gestational complications, chronic metabolic acidosis, and malnutrition. Growing experimental evidence shows that SNAT5 is overexpressed in several types of cancer cells. Moreover, recently published results indicate that SNAT5 expression in stromal cells can support the metabolic exchanges occurring in the tumor microenvironment of asparagine-auxotroph tumors. We review the functional role of the SNAT5 transporter in pathophysiology and propose that, due to its peculiar operational and regulatory features, SNAT5 may play important pro-cancer roles when expressed either in neoplastic or in stromal cells of glutamine-auxotroph tumors.NEW & NOTEWORTHY The transporter SLC38A5/SNAT5 provides net influx or efflux of glutamine, asparagine, and serine. These amino acids are of particular metabolic relevance in several conditions. Changes in transporter expression or activity have been described in selected types of human cancers, where SNAT5 can mediate amino acid exchanges between tumor and stromal cells, thus providing a potential therapeutic target. This is the first review that recapitulates the characteristics and roles of the transporter in physiology and pathology.
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Affiliation(s)
- Giuseppe Taurino
- Laboratory of General Pathology, Department of Medicine and Surgery, University of Parma, Parma, Italy
- MRH-Microbiome Research Hub, University of Parma, Parma, Italy
| | - Martina Chiu
- Laboratory of General Pathology, Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - Massimiliano G Bianchi
- Laboratory of General Pathology, Department of Medicine and Surgery, University of Parma, Parma, Italy
- MRH-Microbiome Research Hub, University of Parma, Parma, Italy
| | - Erika Griffini
- Laboratory of General Pathology, Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - Ovidio Bussolati
- Laboratory of General Pathology, Department of Medicine and Surgery, University of Parma, Parma, Italy
- MRH-Microbiome Research Hub, University of Parma, Parma, Italy
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Ju K, Kil M, Ri S, Kim T, Kim J, Shi W, Zhang L, Yan M, Zhang J, Liu G. Impacts of dietary supplementation of bamboo vinegar and charcoal powder on growth performance, intestinal morphology, and gut microflora of large-scale loach Paramisgurnus dabryanus. JOURNAL OF OCEANOLOGY AND LIMNOLOGY 2023; 41:1-10. [PMID: 36848297 PMCID: PMC9942046 DOI: 10.1007/s00343-022-1412-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 03/30/2022] [Indexed: 06/18/2023]
Abstract
Although accumulating data demonstrate that dietary supplementation of bamboo vinegar and charcoal powder (BVC) can significantly strengthen the immunity and boost the growth of domestic animals, its application potency still awaits verification in commercial fish species such as the large-scale loach Paramisgurnus dabryanus. The impacts of 90-day dietary supplementation of 1% and 2% BVC on survival and growth performance of the loach, and on the intestinal morphological characteristics and gut microflora were analyzed. Our data show that the large-scale loach supplied with BVC at the experimental doses had significant higher survival rates and better growth performance (indicated by greater weight gain (1.13-1.14 times), higher specific growth rate (1.04 times), and lower feed conversion ratio (0.88-0.89 times)) compared to that of the control (P<0.05). Histological examination revealed significant longer villus (3.22-5.54 times), deeper crypt (1.77-1.87 times), and thicker muscle (1.59-3.17 times) in the intestines of large-scale loach fed with BVC (P<0.05). Furthermore, we found that the gut microflora consisted of significantly fewer proportions of potential pathogenic bacterial species (Aeromonas veronii and Escherichia coli), but significantly greater proportions of beneficial microbes (Lactococus raffinolactis and Faecalibacterium prausnitzii). Therefore, dietary intake of BVC can promote intestinal tract development and optimize gut microflora, by which the survival and growth of large-scale loach may be improved.
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Affiliation(s)
- Kwangjin Ju
- College of Animal Sciences, Zhejiang University, Hangzhou, 310058 China
- College of Aquaculture, Wonsan Fisheries University, Wonsan, 999093 Democratic People’s Republic of Korea
| | - Myongsuk Kil
- College of Aquaculture, Wonsan Fisheries University, Wonsan, 999093 Democratic People’s Republic of Korea
| | - Sanghyok Ri
- College of Animal Sciences, Zhejiang University, Hangzhou, 310058 China
- College of Life Science, Kim Hyong Jik University of Education, Pyongyang, 99903 Democratic People’s Republic of Korea
| | - Tongchol Kim
- College of Animal Sciences, Zhejiang University, Hangzhou, 310058 China
- College of Life Science, Kim Hyong Jik University of Education, Pyongyang, 99903 Democratic People’s Republic of Korea
| | - Juhyok Kim
- College of Aquaculture, Wonsan Fisheries University, Wonsan, 999093 Democratic People’s Republic of Korea
| | - Wei Shi
- College of Animal Sciences, Zhejiang University, Hangzhou, 310058 China
| | - Lining Zhang
- Zhejiang Mariculture Research Institute, Wenzhou, 325005 China
| | - Maocang Yan
- Zhejiang Mariculture Research Institute, Wenzhou, 325005 China
| | - Jiongming Zhang
- Zhejiang Mariculture Research Institute, Wenzhou, 325005 China
| | - Guangxu Liu
- College of Animal Sciences, Zhejiang University, Hangzhou, 310058 China
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Wang Z, Yemanyi F, Blomfield AK, Bora K, Huang S, Liu CH, Britton WR, Cho SS, Tomita Y, Fu Z, Ma JX, Li WH, Chen J. Amino acid transporter SLC38A5 regulates developmental and pathological retinal angiogenesis. eLife 2022; 11:e73105. [PMID: 36454214 PMCID: PMC9714971 DOI: 10.7554/elife.73105] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 11/17/2022] [Indexed: 12/03/2022] Open
Abstract
Amino acid (AA) metabolism in vascular endothelium is important for sprouting angiogenesis. SLC38A5 (solute carrier family 38 member 5), an AA transporter, shuttles neutral AAs across cell membrane, including glutamine, which may serve as metabolic fuel for proliferating endothelial cells (ECs) to promote angiogenesis. Here, we found that Slc38a5 is highly enriched in normal retinal vascular endothelium, and more specifically, in pathological sprouting neovessels. Slc38a5 is suppressed in retinal blood vessels from Lrp5-/- and Ndpy/- mice, both genetic models of defective retinal vascular development with Wnt signaling mutations. Additionally, Slc38a5 transcription is regulated by Wnt/β-catenin signaling. Genetic deficiency of Slc38a5 in mice substantially delays retinal vascular development and suppresses pathological neovascularization in oxygen-induced retinopathy modeling ischemic proliferative retinopathies. Inhibition of SLC38A5 in human retinal vascular ECs impairs EC proliferation and angiogenic function, suppresses glutamine uptake, and dampens vascular endothelial growth factor receptor 2. Together these findings suggest that SLC38A5 is a new metabolic regulator of retinal angiogenesis by controlling AA nutrient uptake and homeostasis in ECs.
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Affiliation(s)
- Zhongxiao Wang
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical SchoolBostonUnited States
| | - Felix Yemanyi
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical SchoolBostonUnited States
| | - Alexandra K Blomfield
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical SchoolBostonUnited States
| | - Kiran Bora
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical SchoolBostonUnited States
| | - Shuo Huang
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical SchoolBostonUnited States
| | - Chi-Hsiu Liu
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical SchoolBostonUnited States
| | - William R Britton
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical SchoolBostonUnited States
| | - Steve S Cho
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical SchoolBostonUnited States
| | - Yohei Tomita
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical SchoolBostonUnited States
| | - Zhongjie Fu
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical SchoolBostonUnited States
| | - Jian-xing Ma
- Department of Biochemistry, Wake Forest University School of MedicineWinston-SalemUnited States
| | - Wen-hong Li
- Departments of Cell Biology and of Biochemistry, University of Texas Southwestern Medical CenterDallasUnited States
| | - Jing Chen
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical SchoolBostonUnited States
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Ma L, Yu J, Zhang H, Zhao B, Zhang J, Yang D, Luo F, Wang B, Jin B, Liu J. Effects of Immune Cells on Intestinal Stem Cells: Prospects for Therapeutic Targets. Stem Cell Rev Rep 2022; 18:2296-2314. [DOI: 10.1007/s12015-022-10347-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/27/2022] [Indexed: 11/29/2022]
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Nepal N, Arthur S, Butts MR, Singh S, Palaniappan B, Sundaram U. Molecular Mechanism of Stimulation of Na-K-ATPase by Leukotriene D4 in Intestinal Epithelial Cells. Int J Mol Sci 2021; 22:ijms22147569. [PMID: 34299188 PMCID: PMC8303499 DOI: 10.3390/ijms22147569] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 07/02/2021] [Accepted: 07/07/2021] [Indexed: 12/03/2022] Open
Abstract
Na-K-ATPase provides a favorable transcellular Na gradient required for the functioning of Na-dependent nutrient transporters in intestinal epithelial cells. The primary metabolite for enterocytes is glutamine, which is absorbed via Na-glutamine co-transporter (SN2; SLC38A5) in intestinal crypt cells. SN2 activity is stimulated during chronic intestinal inflammation, at least in part, secondarily to the stimulation of Na-K-ATPase activity. Leukotriene D4 (LTD4) is known to be elevated in the mucosa during chronic enteritis, but the way in which it may regulate Na-K-ATPase is not known. In an in vitro model of rat intestinal epithelial cells (IEC-18), Na-K-ATPase activity was significantly stimulated by LTD4. As LTD4 mediates its action via Ca-dependent protein kinase C (PKC), Ca levels were measured and were found to be increased. Phorbol 12-myristate 13-acetate (PMA), an activator of PKC, also mediated stimulation of Na-K-ATPase like LTD4, while BAPTA-AM (Ca chelator) and calphostin-C (Cal-C; PKC inhibitor) prevented the stimulation of Na-K-ATPase activity. LTD4 caused a significant increase in mRNA and plasma membrane protein expression of Na-K-ATPase α1 and β1 subunits, which was prevented by calphostin-C. These data demonstrate that LTD4 stimulates Na-K-ATPase in intestinal crypt cells secondarily to the transcriptional increase of Na-K-ATPase α1 and β1 subunits, mediated via the Ca-activated PKC pathway.
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Rahman MM, Afroz S, Arthur S, Sundaram U. Mast Cell Mediated Regulation of Small Intestinal Chloride Malabsorption in SAMP1/YitFc Mouse Model of Spontaneous Chronic Ileitis. Cells 2021; 10:cells10030697. [PMID: 33801010 PMCID: PMC8004028 DOI: 10.3390/cells10030697] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 03/13/2021] [Accepted: 03/18/2021] [Indexed: 12/19/2022] Open
Abstract
In Inflammatory Bowel Disease (IBD), malabsorption of electrolytes (NaCl) results in diarrhea. Inhibition of coupled NaCl absorption, mediated by the dual operation of Na:H and Cl:HCO3 exchangers on the brush border membrane (BBM) of the intestinal villus cells has been reported in IBD. In the SAMP1/YitFcs (SAMP1) mice model of spontaneous ileitis, representing Crohn’s disease, DRA (Downregulated in Adenoma) mediated Cl:HCO3 exchange was shown to be inhibited secondary to diminished affinity of the exchanger for Cl. However, NHE3 mediated Na:H exchange remained unaffected. Mast cells and their secreted mediators are known to be increased in the IBD mucosa and can affect intestinal electrolyte absorption. However, how mast cell mediators may regulate Cl:HCO3 exchange in SAMP1 mice is unknown. Therefore, the aim of this study was to determine the effect of mast cell mediators on the downregulation of DRA in SAMP1 mice. Mast cell numbers and their degranulation marker enzyme (β-hexosaminidase) levels were significantly increased in SAMP1 mice compared to control AKR mice. However, treatment of SAMP1 mice with a mast cell stabilizer, ketotifen, restored the β-hexosaminidase enzyme levels to normal in the intestine, demonstrating stabilization of mast cells by ketotifen. Moreover, downregulation of Cl:HCO3 exchange activity was restored in ketotifen treated SAMP1 mice. Kinetic studies showed that ketotifen restored the altered affinity of Cl:HCO3 exchange in SAMP1 mice villus cells thus reinstating its activity to normal. Further, RT-qPCR, Western blot and immunofluorescence studies showed that the expression levels of DRA mRNA and BBM protein, respectively remained unaltered in all experimental conditions, supporting the kinetic data. Thus, inhibition of Cl:HCO3 exchange resulting in chloride malabsorption leading to diarrhea in IBD is likely mediated by mast cell mediators.
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Sniegowski T, Korac K, Bhutia YD, Ganapathy V. SLC6A14 and SLC38A5 Drive the Glutaminolysis and Serine-Glycine-One-Carbon Pathways in Cancer. Pharmaceuticals (Basel) 2021; 14:ph14030216. [PMID: 33806675 PMCID: PMC8000594 DOI: 10.3390/ph14030216] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 02/24/2021] [Accepted: 02/25/2021] [Indexed: 02/06/2023] Open
Abstract
The glutaminolysis and serine–glycine–one-carbon pathways represent metabolic reactions that are reprogramed and upregulated in cancer; these pathways are involved in supporting the growth and proliferation of cancer cells. Glutaminolysis participates in the production of lactate, an oncometabolite, and also in anabolic reactions leading to the synthesis of fatty acids and cholesterol. The serine–glycine–one-carbon pathway is involved in the synthesis of purines and pyrimidines and the control of the epigenetic signature (DNA methylation, histone methylation) in cancer cells. Methionine is obligatory for most of the methyl-transfer reactions in the form of S-adenosylmethionine; here, too, the serine–glycine–one-carbon pathway is necessary for the resynthesis of methionine following the methyl-transfer reaction. Glutamine, serine, glycine, and methionine are obligatory to fuel these metabolic pathways. The first three amino acids can be synthesized endogenously to some extent, but the need for these amino acids in cancer cells is so high that they also have to be acquired from extracellular sources. Methionine is an essential amino acid, thus making it necessary for cancer cells to acquire this amino acid solely from the extracellular milieu. Cancer cells upregulate specific amino acid transporters to meet this increased demand for these four amino acids. SLC6A14 and SLC38A5 are the two transporters that are upregulated in a variety of cancers to mediate the influx of glutamine, serine, glycine, and methionine into cancer cells. SLC6A14 is a Na+/Cl− -coupled transporter for multiple amino acids, including these four amino acids. In contrast, SLC38A5 is a Na+-coupled transporter with rather restricted specificity towards glutamine, serine, glycine, and methionine. Both transporters exhibit unique functional features that are ideal for the rapid proliferation of cancer cells. As such, these two amino acid transporters play a critical role in promoting the survival and growth of cancer cells and hence represent novel, hitherto largely unexplored, targets for cancer therapy.
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Butts M, Singh S, Haynes J, Arthur S, Sundaram U. Moderate Alcohol Consumption Uniquely Regulates Sodium-Dependent Glucose Co-Transport in Rat Intestinal Epithelial Cells In Vitro and In Vivo. J Nutr 2020; 150:747-755. [PMID: 31769840 PMCID: PMC7138678 DOI: 10.1093/jn/nxz277] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 07/31/2019] [Accepted: 10/15/2019] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Chronic alcohol use often leads to malnutrition. However, how the intestinal absorption of nutrients such as glucose may be affected during moderate ethanol use has not been investigated. Glucose is absorbed via sodium (Na)-dependent glucose co-transport (SGLT1; SLC5A1) along the brush border membrane (BBM) of intestinal absorptive villus cells. OBJECTIVE The aim of this study was to investigate how moderate alcohol consumption affects the absorption of glucose via SGLT1. METHODS Intestinal epithelial cells (IEC-18; rat) were exposed to 8.64 mM ethanol over 1, 3, 6, and 12 h. Rats (16-wk-old, male, Sprague-Dawley) were administered 2 g/kg ethanol over 1, 3, and 6 h. Na-dependent 3H-O-methyl-d-glucose uptake was measured to assess SGLT1 activity. Na-K-ATPase activity was measured as a function of inorganic phosphate release. Protein expression was analyzed by Western blot analysis and immunohistochemical staining. RESULTS Ethanol significantly decreased Na-dependent glucose absorption in enterocytes in vitro (ethanol treatment: 48.4% of controls at 1 h; P < 0.01) and in vivo (ethanol treatment: 60.0% of controls at 1 h; P < 0.01). Na-K-ATPase activity was significantly inhibited in vitro (ethanol treatment: 36.9% of controls at 1 h; P < 0.01) and in vivo (ethanol treatment: 42.1% of controls at 1 h; P < 0.01). Kinetic studies showed that the mechanism of inhibition of Na-glucose co-transport was secondary to a decrease in the affinity (1/Km) of the co-transporter for glucose both in vitro and in vivo. Western blots and immunohistochemistry further demonstrated unaltered amounts of SGLT1 after ethanol treatment. CONCLUSIONS Moderate ethanol significantly decreases glucose absorption in IEC-18 cells and in villus cells of Sprague-Dawley rats. The inhibition of SGLT1 is secondary to an altered Na gradient at the cellular level and secondary to diminished affinity of the co-transporter for glucose at the protein level in the BBM. These observations may, at least in part, explain 1 possible mechanism of the onset of malnutrition associated with alcohol consumption.
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Affiliation(s)
- Molly Butts
- Department of Clinical and Translational Sciences, Marshall University, Huntington, WV, USA
| | - Soudamani Singh
- Department of Clinical and Translational Sciences, Marshall University, Huntington, WV, USA
| | - Jennifer Haynes
- Department of Clinical and Translational Sciences, Marshall University, Huntington, WV, USA
| | - Subha Arthur
- Department of Clinical and Translational Sciences, Marshall University, Huntington, WV, USA
| | - Uma Sundaram
- Department of Clinical and Translational Sciences, Marshall University, Huntington, WV, USA,Address correspondence to US (e-mail: )
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Singh S, Arthur S, Sundaram U. Mechanisms of Regulation of Transporters of Amino Acid Absorption in Inflammatory Bowel Diseases. Compr Physiol 2020; 10:673-686. [PMID: 32163200 DOI: 10.1002/cphy.c190016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Intestinal absorption of dietary amino acids/peptides is essential for protein homeostasis, which in turn is crucial for maintaining health as well as restoration of health from significant diseases. Dietary amino acids/peptides are absorbed by unique transporter processes present in the brush border membrane of absorptive villus cells, which line the entire length of the intestine. To date, the only nutrient absorptive system described in the secretory crypt cells in the mammalian intestine is the one that absorbs the amino acid glutamine. Majority of the amino acid transporters are sodium dependent and therefore require basolateral membrane Na-K-ATPase to maintain an efficient transcellular Na gradient for their activity. These transport processes are tightly regulated by various cellular and molecular mechanisms that facilitate their optimal activity during normal physiological processes. Malabsorption of amino acids, recently described in pathophysiological states such as in inflammatory bowel disease (IBD), is undoubtedly responsible for the debilitating symptoms of IBD such as malnutrition, weight loss and ultimately a failure to thrive. Also recently, in vivo models of IBD and in vitro studies have demonstrated that specific immune-inflammatory mediators/pathways regulate specific amino acid transporters. This provides possibilities to derive novel nutrition and immune-based treatment options for conditions such as IBD. © 2020 American Physiological Society. Compr Physiol 10:673-686, 2020.
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Affiliation(s)
- Soudamani Singh
- Department of Clinical and Translational Sciences and Appalachian Clinical and Translational Science Institute, Joan C. Edwards School of Medicine, Marshall University, Huntington, West Virginia, USA
| | - Subha Arthur
- Department of Clinical and Translational Sciences and Appalachian Clinical and Translational Science Institute, Joan C. Edwards School of Medicine, Marshall University, Huntington, West Virginia, USA
| | - Uma Sundaram
- Department of Clinical and Translational Sciences and Appalachian Clinical and Translational Science Institute, Joan C. Edwards School of Medicine, Marshall University, Huntington, West Virginia, USA
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Moderate Alcohol Consumption Inhibits Sodium-Dependent Glutamine Co-Transport in Rat Intestinal Epithelial Cells in Vitro and Ex Vivo. Nutrients 2019; 11:nu11102516. [PMID: 31635319 PMCID: PMC6835445 DOI: 10.3390/nu11102516] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 10/13/2019] [Accepted: 10/15/2019] [Indexed: 12/16/2022] Open
Abstract
Malnutrition is present in chronic alcoholics. However, how moderate alcohol consumption affects the absorption of nutrients like glutamine has not been investigated. Glutamine, an amino acid, is vital to gastrointestinal health. Glutamine is absorbed via sodium-dependent glutamine co-transport (B0AT1; SLC6A19) along the brush border membrane of absorptive villus cells. Rat intestinal epithelial cells (IEC-18) and sixteen-week-old Sprague Dawley rats were administered the equivalent of a 0.04% blood alcohol content of ethanol (8.64 mM; 2 g/kg) to investigate the effect of moderate alcohol on sodium-glutamine co-transport. Sodium-dependent 3H-glutamine uptakes were performed to measure B0AT1 activity. Inorganic phosphate was measured as a function of Na-K-ATPase activity. Protein expression was analyzed by immunohistochemical and Western blot analysis. Ethanol significantly inhibited sodium-dependent glutamine absorption and Na-K-ATPase activity in enterocytes in vitro and ex vivo. Kinetic studies suggested that the mechanism of inhibition was due to decreased maximal rate of uptake (Vmax) of the B0AT1 co-transporter, corresponding to decreased B0AT1 protein expression and secondary to an inhibited sodium-gradient at the cellular level in vitro and ex vivo. In all, moderate ethanol significantly inhibited glutamine absorption at the level of decreased B0AT1 expression at the brush border membrane and a reduced sodium gradient, which may contribute to malnutrition present in chronic alcoholics.
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Nepal N, Arthur S, Sundaram U. Unique Regulation of Na-K-ATPase during Growth and Maturation of Intestinal Epithelial Cells. Cells 2019; 8:cells8060593. [PMID: 31208048 PMCID: PMC6628168 DOI: 10.3390/cells8060593] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Revised: 06/09/2019] [Accepted: 06/13/2019] [Indexed: 12/25/2022] Open
Abstract
Na-K-ATPase on the basolateral membrane provides the favorable transcellular Na gradient for the proper functioning of Na-dependent nutrient co-transporters on the brush border membrane (BBM) of enterocytes. As cells mature from crypts to villus, Na-K-ATPase activity doubles, to accommodate for the increased BBM Na-dependent nutrient absorption. However, the mechanism of increased Na-K-ATPase activity during the maturation of enterocytes is not known. Therefore, this study aimed to determine the mechanisms involved in the functional transition of Na-K-ATPase during the maturation of crypts to villus cells. Na-K-ATPase activity gradually increased as IEC-18 cells matured in vitro from day 0 (crypts) through day 4 (villus) of post-confluence. mRNA abundance and Western blot studies showed no change in the levels of Na-K-ATPase subunits α1 and β1 from 0 to 4 days post-confluent cells. However, Na-K-ATPase α1 phosphorylation levels on serine and tyrosine, but not threonine, residues gradually increased. These data indicate that as enterocytes mature from crypt-like to villus-like in culture, the functional activity of Na-K-ATPase increases secondary to altered affinity of the α1 subunit to extracellular K+, in order to accommodate the functional preference of the intestinal cell type. This altered affinity is likely due to increased phosphorylation of the α1 subunit, specifically at serine and tyrosine residues.
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Affiliation(s)
- Niraj Nepal
- Department of Clinical and Translational Sciences and Appalachian Clinical and Translational Science Institute, Joan C. Edwards School of Medicine, Marshall University, 1600 Medical Center Drive, Huntington, WV 25701, USA.
| | - Subha Arthur
- Department of Clinical and Translational Sciences and Appalachian Clinical and Translational Science Institute, Joan C. Edwards School of Medicine, Marshall University, 1600 Medical Center Drive, Huntington, WV 25701, USA.
| | - Uma Sundaram
- Department of Clinical and Translational Sciences and Appalachian Clinical and Translational Science Institute, Joan C. Edwards School of Medicine, Marshall University, 1600 Medical Center Drive, Huntington, WV 25701, USA.
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Yuan W, Hou S, Jia H, Qiu Z, Liu T, Chen X, Li H, Sun Y, Liang L, Sui X, Zhao X, Zhao Z. Ketotifen fumarate attenuates feline gingivitis related with gingival microenvironment modulation. Int Immunopharmacol 2018; 65:159-173. [PMID: 30316074 DOI: 10.1016/j.intimp.2018.10.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 10/02/2018] [Accepted: 10/04/2018] [Indexed: 11/17/2022]
Abstract
Gingivitis is evidenced by inflammation of the free gingiva, and still reversible. If left untreated, it may then progress to periodontitis. In the present study, the therapeutical effect of ketotifen fumarate on gingivitis was explored. Domestic cats with varying degrees of gingivitis naturally were enrolled in this study. Subgroups of animals were treated twice daily for one week with or without ketotifen fumarate (5 mg/kg). Effects of ketotifen fumarate were measured on gingival index, cells accumulation, mediators release, receptor-ligand interaction, oxidative stress, MAPK and NF-κB pathways, epithelial barrier and apoptosis. Ketotifen fumarate attenuated the initiation and progression of gingivitis, inhibited the infiltrations of mast cells, B lymphocytes, T lymphocytes, macrophages, neutrophils and eosinophils as well as the release of IgE, β-hexosaminidase, tryptase, chymase, TNF-α, IL-4, and IL-13, influenced endothelial cells, fibroblasts and epithelial cells proliferation and apoptosis, and induced Th2 cells polarization, where ketotifen fumarate also might affect their interactions. Ketotifen fumarate reduced the oxidative stress, and inhibited NF-κB and p38 MAPK related with mast cells and macrophages accumulation. Ketotifen fumarate improved the aberrant expression of ZO-1 and inhibits the following apoptosis. On the other hand, these cells and mediators augmented functional attributes of them involving SCF/c-Kit, α4β7/VCAM-1 and IL-8/IL-8RB interactions, thus creating a positive feedback loop to perpetuate gingivitis, where an inflammation microenvironment was modeled. Our results showed a previously unexplored therapeutic potential of ketotifen fumarate for gingivitis and further suggest that, in addition to biofilms, targeting inflammation microenvironment could be new strategy for the treatment of gingivitis/periodontitis.
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Affiliation(s)
- Weifeng Yuan
- Beijing Institute of Animal Husbandry and Veterinary Medicine, Chinese Academy of Agricultural Sciences, Beijing 100193, People's Republic of China
| | - Shaohua Hou
- Beijing Institute of Animal Husbandry and Veterinary Medicine, Chinese Academy of Agricultural Sciences, Beijing 100193, People's Republic of China
| | - Hong Jia
- Beijing Institute of Animal Husbandry and Veterinary Medicine, Chinese Academy of Agricultural Sciences, Beijing 100193, People's Republic of China
| | - Zhizhao Qiu
- Meilianzhonghe Animal Hospital, Beijing 100077, People's Republic of China
| | - Tao Liu
- College of Animal Husbandry and Veterinary Medicine, Xinyang Agriculture and Forestry University, Xinyang 464001, People's Republic of China
| | - Xinsheng Chen
- Animal Hospital, Shanghai Wild Animal Park, Shanghai 200120, People's Republic of China
| | - Hongjun Li
- Luoyang Animal Husbandry Station, Luoyang 471002, People's Republic of China
| | - Yanchen Sun
- Yichongtang Animal Hospital, Zhengzhou 450016, People's Republic of China
| | - Lin Liang
- Beijing Institute of Animal Husbandry and Veterinary Medicine, Chinese Academy of Agricultural Sciences, Beijing 100193, People's Republic of China
| | - Xiukun Sui
- Beijing Institute of Animal Husbandry and Veterinary Medicine, Chinese Academy of Agricultural Sciences, Beijing 100193, People's Republic of China
| | - Xinghui Zhao
- Beijing Institute of Animal Husbandry and Veterinary Medicine, Chinese Academy of Agricultural Sciences, Beijing 100193, People's Republic of China.
| | - Zhanzhong Zhao
- Beijing Institute of Animal Husbandry and Veterinary Medicine, Chinese Academy of Agricultural Sciences, Beijing 100193, People's Republic of China.
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14
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Kandasamy P, Gyimesi G, Kanai Y, Hediger MA. Amino acid transporters revisited: New views in health and disease. Trends Biochem Sci 2018; 43:752-789. [PMID: 30177408 DOI: 10.1016/j.tibs.2018.05.003] [Citation(s) in RCA: 250] [Impact Index Per Article: 41.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Revised: 05/23/2018] [Accepted: 05/25/2018] [Indexed: 02/09/2023]
Abstract
Amino acid transporters (AATs) are membrane-bound transport proteins that mediate transfer of amino acids into and out of cells or cellular organelles. AATs have diverse functional roles ranging from neurotransmission to acid-base balance, intracellular energy metabolism, and anabolic and catabolic reactions. In cancer cells and diabetes, dysregulation of AATs leads to metabolic reprogramming, which changes intracellular amino acid levels, contributing to the pathogenesis of cancer, obesity and diabetes. Indeed, the neutral amino acid transporters (NATs) SLC7A5/LAT1 and SLC1A5/ASCT2 are likely involved in several human malignancies. However, a clinical therapy that directly targets AATs has not yet been developed. The purpose of this review is to highlight the structural and functional diversity of AATs, their diverse physiological roles in different tissues and organs, their wide-ranging implications in human diseases and the emerging strategies and tools that will be necessary to target AATs therapeutically.
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Affiliation(s)
- Palanivel Kandasamy
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bühlstrasse 28, CH-3012 Bern, Switzerland
| | - Gergely Gyimesi
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bühlstrasse 28, CH-3012 Bern, Switzerland
| | - Yoshikatsu Kanai
- Division of Bio-system Pharmacology, Graduate School of Medicine, Osaka University, Osaka, Japan.
| | - Matthias A Hediger
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bühlstrasse 28, CH-3012 Bern, Switzerland.
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15
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Shi Y, Wang ZE, Wu W, Wu D, Wang C, Peng X. Glutamine protects intestinal mucosa and promotes its transport after burn injury in rats. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2018; 11:1825-1835. [PMID: 31938290 PMCID: PMC6958174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 02/10/2018] [Indexed: 06/10/2023]
Abstract
Glutamine is an important energy source for intestinal epithelial cells (IEC); however, it is still controversial whether glutaminecan be fully utilized under pathological conditions. In this study, we investigated the changes in glutamine transport after burns and assessed the effects of exogenous glutamine administration. Finally, the potential underlying mechanisms were explored. Experimental rats were randomly divided into three groups: control group (C); burn group (B); burn+glutamine group (B+G). Rats in groups B+G and B received intragastric administration of isodose glutamine or alanine, respectively. At days 1, 3 and 5 after burns, the structure of intestinal mucosa and brush-border membrane vesicles (BBMV) were observed. The glutamine transport capacity of IEC and BBMV was detected. The synthesis of glutamine transporter ASCT2 and B0AT1 was determined. Moreover, the intestinal mucosal blood flow (IMBF), diamine oxidase activity, and the glutamine and ATP content were measured. The results showed that burn injury caused structural damage to IECs and BBMV, and significantly impaired the ability for glutamine transportation. Moreover, the mRNA and protein expressions of ASCT2 and B0AT1 as well as the glutamine and ATP content were markedly decreased. Compared with group B, most of these indicators in group B+G showed significant improvement, and approached normal levels. We conclude that glutamine administration can relieve intestinal damage, improve IMBF, promote energy synthesis and alleviate endoplasmic reticulum stress after burn injury. Finally, the synthesis and modification of ASCT2 and B0AT1 are promoted, which ultimately enhances intestinal glutamine transport.
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Affiliation(s)
- Yan Shi
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Burns of PLA, Southwest Hospital, Third Military Medical UniversityChongqing 400038, PR China
| | - Zi-En Wang
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Burns of PLA, Southwest Hospital, Third Military Medical UniversityChongqing 400038, PR China
- Department of Burns, Union Hospital, Fujian Medical UniversityFuzhou 350001, PR China
| | - Wei Wu
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Burns of PLA, Southwest Hospital, Third Military Medical UniversityChongqing 400038, PR China
| | - Dan Wu
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Burns of PLA, Southwest Hospital, Third Military Medical UniversityChongqing 400038, PR China
| | - Chao Wang
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Burns of PLA, Southwest Hospital, Third Military Medical UniversityChongqing 400038, PR China
| | - Xi Peng
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Burns of PLA, Southwest Hospital, Third Military Medical UniversityChongqing 400038, PR China
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16
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Singh S, Arthur S, Sundaram U. Unique regulation of Na-glutamine cotransporter SN2/SNAT5 in rabbit intestinal crypt cells during chronic enteritis. J Cell Mol Med 2017; 22:1443-1451. [PMID: 29271063 PMCID: PMC5824387 DOI: 10.1111/jcmm.13257] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 04/26/2017] [Indexed: 12/12/2022] Open
Abstract
The only Na‐nutrient cotransporter described in mammalian small intestinal crypt cells is SN2/SNAT5, which facilitates glutamine uptake. In a rabbit model of chronic intestinal inflammation, SN2 stimulation is secondary to an increase in affinity of the cotransporter for glutamine. However, the immune regulation of SN2 in the crypt cells during chronic intestinal inflammation is unknown. We sought to determine the mechanism of regulation of Na‐nutrient cotransporter SN2 by arachidonic acid metabolites in crypt cells. The small intestines of New Zealand white male rabbits were inflamed via inoculation with Eimeria magna oocytes. After 2‐week incubation, control and inflamed rabbits were subjected to intramuscular injections of arachidonyl trifluoromethyl ketone (ATK), piroxicam and MK886 for 48 hrs. After injections, the rabbits were euthanized and crypt cells from small intestines were harvested and used. Results: Treatment of rabbits with ATK prevented the release of AA and reversed stimulation of SN2. Inhibition of cyclooxygenase (COX) with piroxicam did not affect stimulation of SN2. However, inhibition of lipoxygenase (LOX) with MK886, thus reducing leukotriene formation during chronic enteritis, reversed the stimulation of SN2. Kinetic studies showed that the mechanism of restoration of SN2 by ATK or MK886 was secondary to the restoration of the affinity of the cotransporter for glutamine. For all treatment conditions, Western blot analysis revealed no change in SN2 protein levels. COX inhibition proved ineffective at reversing the stimulation of SN2. Thus, this study provides evidence that SN2 stimulation in crypt cells is mediated by the leukotriene pathway during chronic intestinal inflammation.
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Affiliation(s)
- Soudamani Singh
- Department of Clinical and Translational Sciences, Appalachian Clinical and Translational Science Institute, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV, USA
| | - Subha Arthur
- Department of Clinical and Translational Sciences, Appalachian Clinical and Translational Science Institute, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV, USA
| | - Uma Sundaram
- Department of Clinical and Translational Sciences, Appalachian Clinical and Translational Science Institute, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV, USA
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17
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Hejazi MM, Bacha AO, Kaleemuddin M, Al-Abassi FA, Al-Alsieni AI, Kazmi I, Anwar F. Alteration of serum immunoglobins, C-reactive protein, vitamin D, and electrolyte by atenolol and amlodipine in stress-induced hypertensive rats. Mol Cell Biochem 2017; 445:99-103. [PMID: 29248973 DOI: 10.1007/s11010-017-3255-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 12/10/2017] [Indexed: 02/07/2023]
Abstract
The present study is designed for the assessment of various pathological changes like immunoglobins, C-reactive protein, vitamin D, sodium, potassium, calcium in stress-induced hypertensive rats. Albino Wistar rats of sex male were grouped into six. Each group consists of six animals. Groups were Group I (normal control), Group II (disease control), Group III (amlodipine control), Group IV (atenolol control), Group V (amlodipine treatment), and Group VI (atenolol treatment). Group II, V, and VI animals exposed to regular stress by placing them in cages individually and giving foot electric shocks (1 mA, 50 ms duration with 0.5-1 min of intervals regulated randomly by a computer) along with forced swimming (30 min) in order to induce hypertension in rats. This stress was given two times daily (morning and evening) for regular 15 days. Induction of hypertension was confirmed by measuring the tail arterial pressure of blood and angiotensin II. For next 1 month, Group III and V animals are treated with amlodipine with 1 mg/kg, s.c. dose while Group IV and VI animals were given 10 mg/kg, s.c. the dose of atenolol once daily. At the end of the experimental work, blood collected, rats sacrificed, and serum separated. Serum sodium, potassium, immunoglobins, C-reactive protein, vitamin D, and calcium were measured by semi-auto-analyzer. Stress-induced hypertension in rats produced altered serum sodium, potassium, immunoglobins, C-reactive protein, vitamin D, and calcium level which is restored by atenolol. Administration of amlodipine in animals without hypertension shows alteration in the level of immunoglobins, calcium, vitamin D, and electrolytes.
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Affiliation(s)
- Moayad Mustafa Hejazi
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Ala Osman Bacha
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Mohammed Kaleemuddin
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Fahad A Al-Abassi
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Abdulbasit I Al-Alsieni
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Imran Kazmi
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia. .,Glocal School of Pharmacy, Glocal University, Sahranpur, Uttar Pradesh, 247121, India.
| | - Firoz Anwar
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia.
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