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Ratsma DMA, Muller M, Koedam M, van Leeuwen JPTM, Zillikens MC, van der Eerden BCJ. Organic phosphate but not inorganic phosphate regulates Fgf23 expression through MAPK and TGF-ꞵ signaling. iScience 2024; 27:109625. [PMID: 38883842 PMCID: PMC11178987 DOI: 10.1016/j.isci.2024.109625] [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: 09/27/2023] [Revised: 01/12/2024] [Accepted: 03/26/2024] [Indexed: 06/18/2024] Open
Abstract
One of the main regulators of phosphate homeostasis is fibroblast growth factor 23 (FGF23), secreted by osteocytes. The effects of organic versus inorganic dietary phosphate on this homeostasis are unclear. This study used MC3T3-E1 FGF23-producing cells to examine the transcriptomic responses to these phosphates. Most importantly, the expression and secretion of FGF23 were only increased in response to organic phosphate. Gene ontology terms related to a response to environmental change were only enriched in cells treated with organic phosphate while cells treated with inorganic phosphate were enriched for terms associated with regulation of cellular phosphate metabolism. Inhibition of MAPK signaling diminished the response of Fgf23 to organic phosphate, suggesting it activates FGF23. TGF-β signaling inhibition increased Fgf23 expression after the addition of organic phosphate, while the negative TGF-β regulator Skil decreased this response. In summary, the observed differential response of FGF23-producing to phosphate types may have consequences for phosphate homeostasis.
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Affiliation(s)
- Danielle M A Ratsma
- Laboratory for Calcium and Bone Metabolism and Erasmus MC Bone Centre, Department of Internal Medicine, Erasmus MC, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Max Muller
- Laboratory for Calcium and Bone Metabolism and Erasmus MC Bone Centre, Department of Internal Medicine, Erasmus MC, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Marijke Koedam
- Laboratory for Calcium and Bone Metabolism and Erasmus MC Bone Centre, Department of Internal Medicine, Erasmus MC, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Johannes P T M van Leeuwen
- Laboratory for Calcium and Bone Metabolism and Erasmus MC Bone Centre, Department of Internal Medicine, Erasmus MC, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - M Carola Zillikens
- Laboratory for Calcium and Bone Metabolism and Erasmus MC Bone Centre, Department of Internal Medicine, Erasmus MC, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Bram C J van der Eerden
- Laboratory for Calcium and Bone Metabolism and Erasmus MC Bone Centre, Department of Internal Medicine, Erasmus MC, Erasmus University Medical Center, Rotterdam, the Netherlands
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2
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Shanti A, Al Adem K, Stefanini C, Lee S. Hydrogen phosphate selectively induces MDA MB 231 triple negative breast cancer cell death in vitro. Sci Rep 2022; 12:5333. [PMID: 35351930 PMCID: PMC8964734 DOI: 10.1038/s41598-022-09299-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 02/28/2022] [Indexed: 12/03/2022] Open
Abstract
Phosphate ions are the most abundant anions inside the cells, and they are increasingly gaining attention as key modulators of cellular function and gene expression. However, little is known about the effect of inorganic phosphate ions on cancer cells, particularly breast cancer cells. Here, we investigated the toxicity of different phosphate compounds to triple-negative human breast cancer cells, particularly, MDA-MB-231, and compared it to that of human monocytes, THP-1. We found that, unlike dihydrogen phosphate (H2PO4−), hydrogen phosphate (HPO42−) at 20 mM or lower concentrations induced breast cancer cell death more than immune cell death, mainly via apoptosis. We correlate this effect to the fact that phosphate in the form of HPO42− raises pH levels to alkaline levels which are not optimum for transport of phosphate into cancer cells. The results in this study highlight the importance of further exploring hydrogen phosphate (HPO42−) as a potential therapeutic for the treatment of breast cancer.
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Affiliation(s)
- Aya Shanti
- Department of Biomedical Engineering, Healthcare Engineering Innovation Center, Khalifa University of Science and Technology, 127788, Abu Dhabi, United Arab Emirates
| | - Kenana Al Adem
- Department of Biomedical Engineering, Healthcare Engineering Innovation Center, Khalifa University of Science and Technology, 127788, Abu Dhabi, United Arab Emirates
| | - Cesare Stefanini
- Department of Biomedical Engineering, Healthcare Engineering Innovation Center, Khalifa University of Science and Technology, 127788, Abu Dhabi, United Arab Emirates
| | - Sungmun Lee
- Department of Biomedical Engineering, Healthcare Engineering Innovation Center, Khalifa University of Science and Technology, 127788, Abu Dhabi, United Arab Emirates. .,Khalifa University's Center for Biotechnology, Khalifa University of Science and Technology, 127788, Abu Dhabi, United Arab Emirates.
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Hu MC, Moe OW. Phosphate and Cellular Senescence. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1362:55-72. [PMID: 35288873 PMCID: PMC10513121 DOI: 10.1007/978-3-030-91623-7_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Cellular senescence is one type of permeant arrest of cell growth and one of increasingly recognized contributor to aging and age-associated disease. High phosphate and low Klotho individually and synergistically lead to age-related degeneration in multiple organs. Substantial evidence supports the causality of high phosphate in cellular senescence, and potential contribution to human aging, cancer, cardiovascular, kidney, neurodegenerative, and musculoskeletal diseases. Phosphate can induce cellular senescence both by direct phosphotoxicity, and indirectly through downregulation of Klotho and upregulation of plasminogen activator inhibitor-1. Restriction of dietary phosphate intake and blockage of intestinal absorption of phosphate help suppress cellular senescence. Supplementation of Klotho protein, cellular senescence inhibitor, and removal of senescent cells with senolytic agents are potential novel strategies to attenuate phosphate-induced cellular senescence, retard aging, and ameliorate age-associated, and phosphate-induced disorders.
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Affiliation(s)
- Ming Chang Hu
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX, USA.
- Departments of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA.
| | - Orson W Moe
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Departments of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Departments of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
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Phosphate Dysregulation and Neurocognitive Sequelae. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1362:151-160. [DOI: 10.1007/978-3-030-91623-7_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Worrall E, Were V, Matope A, Gama E, Olewe J, Mwambi D, Desai M, Kariuki S, Buff AM, Niessen LW. Coverage outcomes (effects), costs, cost-effectiveness, and equity of two combinations of long-lasting insecticidal net (LLIN) distribution channels in Kenya: a two-arm study under operational conditions. BMC Public Health 2020; 20:1870. [PMID: 33287766 PMCID: PMC7720381 DOI: 10.1186/s12889-020-09846-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 11/05/2020] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Malaria-endemic countries distribute long-lasting insecticidal nets (LLINs) through combined channels with ambitious, universal coverage (UC) targets. Kenya has used eight channels with variable results. To inform national decision-makers, this two-arm study compares coverage (effects), costs, cost-effectiveness, and equity of two combinations of LLIN distribution channels in Kenya. METHODS Two combinations of five delivery channels were compared as 'intervention' and 'control' arms. The intervention arm comprised four channels: community health volunteer (CHV), antenatal and child health clinics (ANCC), social marketing (SM) and commercial outlets (CO). The control arm consisted of the intervention arm channels except mass campaign (MC) replaced CHV. Primary analysis used random sample household survey data, service-provider costs, and voucher or LLIN distribution data to compare between-arm effects, costs, cost-effectiveness, and equity. Secondary analyses compared costs and equity by channel. RESULTS The multiple distribution channels used in both arms of the study achieved high LLIN ownership and use. The intervention arm had significantly lower reported LLIN use the night before the survey (84·8% [95% CI 83·0-86·4%] versus 89·2% [95% CI 87·8-90·5%], p < 0·0001), higher unit costs ($10·56 versus $7·17), was less cost-effective ($86·44, 95% range $75·77-$102·77 versus $69·20, 95% range $63·66-$77·23) and more inequitable (Concentration index [C.Ind] = 0·076 [95% CI 0·057 to 0·095 versus C.Ind = 0.049 [95% CI 0·030 to 0·067]) than the control arm. Unit cost per LLIN distributed was lowest for MC ($3·10) followed by CHV ($10·81) with both channels being moderately inequitable in favour of least-poor households. CONCLUSION In line with best practices, the multiple distribution channel model achieved high LLIN ownership and use in this Kenyan study setting. The control-arm combination, which included MC, was the most cost-effective way to increase UC at household level. Mass campaigns, combined with continuous distribution channels, are an effective and cost-effective way to achieve UC in Kenya. The findings are relevant to other countries and donors seeking to optimise LLIN distribution. TRIAL REGISTRATION The assignment of the intervention was not at the discretion of the investigators; therefore, this study did not require registration.
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Affiliation(s)
- Eve Worrall
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK
| | - Vincent Were
- Centre for Applied Health Research and Delivery (CAHRD), Liverpool School of Tropical Medicine, Liverpool, UK
- Kenya Medical Research Institute and Centre for Global Health Research, Kisumu, Kenya
| | - Agnes Matope
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK
| | - Elvis Gama
- Directorate of Quality Management and Digital Health, Ministry of Health and Population, Lilongwe, Malawi
| | - Joseph Olewe
- Kenya Medical Research Institute and Centre for Global Health Research, Kisumu, Kenya
| | - Dennis Mwambi
- Population Services Kenya (PS Kenya), Nairobi, Kenya
- Population Reference Bureau, Nairobi, Kenya
| | - Meghna Desai
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, U.S. Centers for Disease Control and Prevention, Atlanta, GA USA
| | - Simon Kariuki
- Kenya Medical Research Institute and Centre for Global Health Research, Kisumu, Kenya
| | - Ann M. Buff
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, U.S. Centers for Disease Control and Prevention, Atlanta, GA USA
- U.S. President’s Malaria Initiative, Nairobi, Kenya
| | - Louis W. Niessen
- Centre for Applied Health Research and Delivery (CAHRD), Liverpool School of Tropical Medicine, Liverpool, UK
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He P, Mann-Collura O, Fling J, Edara N, Hetz R, Razzaque MS. High phosphate actively induces cytotoxicity by rewiring pro-survival and pro-apoptotic signaling networks in HEK293 and HeLa cells. FASEB J 2020; 35:e20997. [PMID: 32892444 DOI: 10.1096/fj.202000799rr] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 08/12/2020] [Accepted: 08/19/2020] [Indexed: 02/06/2023]
Abstract
Inorganic phosphate (Pi) is an essential nutrient for human health. Due to the changes in our dietary pattern, dietary Pi overload engenders systemic phosphotoxicity, including excessive Pi-related vascular calcification and chronic tissue injury. The molecular mechanisms of the seemingly distinct phenotypes remain elusive. In this study, we investigated Pi-mediated cellular response in HEK293 and HeLa cells. We found that abnormally high Pi directly mediates diverse cellular toxicity in a dose-dependent manner. Up to 10 mM extracellular Pi promotes cell proliferation by activating AKT signaling cascades and augmenting cell cycle progression. By introducing additional Pi, higher than the concentration of 40 mM, we observed significant cell damage caused by the interwoven Pi-related biological processes. Elevated Pi activates mitogen-activated protein kinase (MAPK) signaling, encompassing extracellular signal-regulated kinase 1/2 (ERK1/2), p38 and Jun amino-terminal kinase (JNK), which consequently potentiates Pi triggered lethal epithelial-mesenchymal transition (EMT). Synergistically, high Pi-caused endoplasmic reticulum (ER) stress also contributes to apparent apoptosis. To counteract, Pi-activated AKT signaling promotes cell survival by activating the mammalian target of rapamycin (mTOR) signaling and blocking ER stress. Pharmacologically or genetically abrogating Pi transport, the impact of high Pi-induced cytotoxicity could be reduced. Taken together, abnormally high extracellular Pi results in a broad spectrum of toxicity by rewiring complicated signaling networks that control cell growth, cell death, and homeostasis.
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Affiliation(s)
- Ping He
- Department of Biochemistry, Lake Erie College of Osteopathic Medicine, Erie, PA, USA
| | - Olivia Mann-Collura
- Department of Biochemistry, Lake Erie College of Osteopathic Medicine, Erie, PA, USA
| | - Jacob Fling
- Department of Biochemistry, Lake Erie College of Osteopathic Medicine, Erie, PA, USA
| | - Naga Edara
- Department of Biochemistry, Lake Erie College of Osteopathic Medicine, Erie, PA, USA
| | - Rebecca Hetz
- Department of Biochemistry, Lake Erie College of Osteopathic Medicine, Erie, PA, USA
| | - Mohammed S Razzaque
- Department of Pathology, Lake Erie College of Osteopathic Medicine, Erie, PA, USA
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Mizuno M, Mitchell JH, Crawford S, Huang CL, Maalouf N, Hu MC, Moe OW, Smith SA, Vongpatanasin W. High dietary phosphate intake induces hypertension and augments exercise pressor reflex function in rats. Am J Physiol Regul Integr Comp Physiol 2016; 311:R39-48. [PMID: 27170660 PMCID: PMC4967233 DOI: 10.1152/ajpregu.00124.2016] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 05/06/2016] [Indexed: 01/14/2023]
Abstract
An increasing number of studies have linked high dietary phosphate (Pi) intake to hypertension. It is well established that the rise in sympathetic nerve activity (SNA) and blood pressure (BP) during physical exertion is exaggerated in many forms of hypertension, which are primarily mediated by an overactive skeletal muscle exercise pressor reflex (EPR). However, it remains unknown whether high dietary Pi intake potentiates the EPR-mediated SNA and BP response to exercise. Accordingly, we measured renal SNA (RSNA) and mean BP (MBP) in normotensive Sprague-Dawley rats fed a normal Pi diet (0.6%, n = 13) or high Pi diet (1.2%, n = 13) for 3 mo. As previously reported, we found that resting BP was significantly increased by 1.2% Pi diet in both conscious and anesthetized animals. Activation of the EPR by electrically induced hindlimb contraction triggered greater increases in ΔRSNA and ΔMBP in the 1.2% compared with 0.6% Pi group (126 ± 25 vs. 42 ± 9%; 44 ± 5 vs. 14 ± 2 mmHg, respectively, P < 0.01). Activation of the muscle mechanoreflex, a component of the EPR, by passively stretching hindlimb muscle also evoked greater increases in ΔRSNA and ΔMBP in the 1.2% compared with 0.6% Pi group (109 ± 27 vs. 24 ± 7%, 38 ± 7 vs. 8 ± 2 mmHg, respectively, P < 0.01). A similar response was produced by hindlimb intra-arterial capsaicin administration to stimulate the metaboreflex arm of the EPR. Thus, our data demonstrate a novel action of dietary Pi loading in augmenting EPR function through overactivation of both the muscle mechanoreflex and metaboreflex.
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Affiliation(s)
- Masaki Mizuno
- Department of Health Care Sciences, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas; Cardiology Division, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Jere H Mitchell
- Cardiology Division, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Scott Crawford
- Department of Health Care Sciences, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Chou-Long Huang
- Nephrology Division, University of Texas Southwestern Medical Center, Dallas, Texas; Charles and Jane Pak Center of Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Naim Maalouf
- Mineral Metabolism Division, University of Texas Southwestern Medical Center, Dallas, Texas; and Charles and Jane Pak Center of Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Ming-Chang Hu
- Mineral Metabolism Division, University of Texas Southwestern Medical Center, Dallas, Texas; and Charles and Jane Pak Center of Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Orson W Moe
- Nephrology Division, University of Texas Southwestern Medical Center, Dallas, Texas; Charles and Jane Pak Center of Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Scott A Smith
- Department of Health Care Sciences, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas; Cardiology Division, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Wanpen Vongpatanasin
- Cardiology Division, University of Texas Southwestern Medical Center, Dallas, Texas; Hypertension Section, University of Texas Southwestern Medical Center, Dallas, Texas; Charles and Jane Pak Center of Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas
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Oster M, Just F, Büsing K, Wolf P, Polley C, Vollmar B, Muráni E, Ponsuksili S, Wimmers K. Toward improved phosphorus efficiency in monogastrics-interplay of serum, minerals, bone, and immune system after divergent dietary phosphorus supply in swine. Am J Physiol Regul Integr Comp Physiol 2016; 310:R917-25. [PMID: 26962023 PMCID: PMC4896080 DOI: 10.1152/ajpregu.00215.2015] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 03/07/2016] [Indexed: 12/20/2022]
Abstract
Phosphorus (P) is of vital importance for many aspects of metabolism, including bone mineralization, blood buffering, and energy utilization. In order to identify molecular routes affecting intrinsic P utilization, we address processes covering P intake, uptake, metabolism, and excretion. In particular, the interrelation of bone tissue and immune features is of interest to approximate P intake to animal's physiology and health status. German Landrace piglets received different levels of digestible phosphorus: recommended, higher, or lower amounts. At multiple time points, relevant serum parameters were analyzed and radiologic studies on bone characteristics were performed. Peripheral blood mononuclear cells were collected to assess differential gene expression. Dietary differences were reflected by serum phosphorus, calcium, parathyroid hormone, and vitamin D. Bone reorganization was persistently affected as shown by microstructural parameters, cathepsin K levels, and transcripts associated with bone formation. Moreover, blood expression patterns revealed a link to immune response, highlighting bidirectional loops comprising bone formation and immune features, where the receptor-activator of NF-κB ligand/receptor-activator of NF-κB kinase system may play a prominent role. The modulated P supplementation provoked considerable organismal plasticity. Genes found to be differentially expressed due to variable P supply are involved in pathways relevant to P utilization and are potential candidate genes for improved P efficiency.
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Affiliation(s)
- Michael Oster
- Leibniz Institute for Farm Animal Biology, Institute for Genome Biology, Dummerstorf, Germany
| | - Franziska Just
- Leibniz Institute for Farm Animal Biology, Institute for Genome Biology, Dummerstorf, Germany
| | - Kirsten Büsing
- University of Rostock, Nutrition Physiology and Animal Nutrition, Rostock, Germany; and
| | - Petra Wolf
- University of Rostock, Nutrition Physiology and Animal Nutrition, Rostock, Germany; and
| | - Christian Polley
- University of Rostock, Institute for Experimental Surgery, Rostock, Germany
| | - Brigitte Vollmar
- University of Rostock, Institute for Experimental Surgery, Rostock, Germany
| | - Eduard Muráni
- Leibniz Institute for Farm Animal Biology, Institute for Genome Biology, Dummerstorf, Germany
| | - Siriluck Ponsuksili
- Leibniz Institute for Farm Animal Biology, Institute for Genome Biology, Dummerstorf, Germany
| | - Klaus Wimmers
- Leibniz Institute for Farm Animal Biology, Institute for Genome Biology, Dummerstorf, Germany;
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Rahabi-Layachi H, Ourouda R, Boullier A, Massy ZA, Amant C. Distinct Effects of Inorganic Phosphate on Cell Cycle and Apoptosis in Human Vascular Smooth Muscle Cells. J Cell Physiol 2015; 230:347-55. [PMID: 24976589 DOI: 10.1002/jcp.24715] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Accepted: 06/23/2014] [Indexed: 12/14/2022]
Abstract
Inorganic phosphate (Pi) is an essential nutrient to all living organisms. Nevertheless, hyperphosphatemia is now recognized as a risk factor for cardiovascular events and mortality in chronic kidney disease (CKD) patients. To our knowledge, the mechanisms by which elevated Pi alters smooth muscle cell proliferation have been poorly addressed. Therefore, in this study, we investigated the effects of Pi on cell cycle regulation and apoptosis in human aortic smooth muscle cells (HAoSMC). HAoSMC were treated with physiologic (1 mM) or high (2 and 3 mM) Pi concentrations. We showed that Pi not only decreased significantly cell viability (P < 0.001) but also induced apoptosis of HAoSMC. Moreover, Pi treatment blocked G1/S cell cycle progression by increasing cell number in G0/G1 phase up to 82.4 ± 3.4% for 3 mM vs 76.2 ± 3.1% for control (P < 0.01) while decreasing cell number in S phase. Accordingly, this was associated with a decrease protein expression of cyclin E and its associated CDK (CDK2), and phosphorylated retinoblastoma protein. Moreover, we observed an increase of protein expression of cell cycle inhibitors p15, p21, and p27. Interestingly, we also found that induction of cell cycle arrest was partially dependent on phosphate uptake. Our results demonstrated that Pi reduced HAoSMC proliferation by inducing apoptosis and cell cycle arrest. Indeed, we showed for the first time that Pi affected HAoSMC cell cycle by blocking G1/S progression. These findings would be useful for a better understanding of molecular mechanisms involved in vascular complications observed in CKD patients.
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Affiliation(s)
| | - Roger Ourouda
- HERVI EA3801, Université de Picardie Jules Verne, UFR de Médecine, Amiens, France
| | - Agnes Boullier
- Inserm U1088, Université de Picardie Jules Verne, Amiens, France
- Centre de Biologie Humaine, CHU Amiens, Amiens, France
- Laboratoire de Biochimie, CHU Amiens, Amiens, France
| | - Ziad A Massy
- Inserm U1088, Université de Picardie Jules Verne, Amiens, France
- Nephrology Division CHU Ambroise Paré, Avenue Charles de Gaulle, Boulogne-Billancourt, France
| | - Carole Amant
- HERVI EA3801, Université de Picardie Jules Verne, UFR de Médecine, Amiens, France
- Centre de Biologie Humaine, CHU Amiens, Amiens, France
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Wang T, Zhai L, Guo Y, Pei H, Zhang M. Picroside II has a neuroprotective effect by inhibiting ERK1/2 activation after cerebral ischemic injury in rats. Clin Exp Pharmacol Physiol 2015; 42:930-939. [PMID: 26175147 DOI: 10.1111/1440-1681.12445] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 06/01/2015] [Accepted: 06/19/2015] [Indexed: 12/11/2022]
Abstract
In the study, the neuroprotective effect and underlying mechanism of picroside II were explored, and its involvement in the ERK1/2 signal pathway after cerebral ischemia injury in rats. A monofilament thread was inserted to generate middle cerebral artery occlusion (MCAO) in 100 Wistar rats that were administered an intraperitoneal injection of picroside II (20 mg/kg). The neurobehavioural function of rats was evaluated using a modified neurological severity score (mNSS) test. The cerebral infarct volume (CIV) was measured using tetrazolium chloride (TTC) staining. The morphology and ultra-structure of the nerve cells in the cortex were observed using hematoxylin and eosin (HE) staining and transmission electron microscopy (TEM), respectively. The apoptotic cells were counted using the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. The expression of extracellular signal-regulated kinase 1/2 (pERK1/2) in the cortex was determined using immunohistochemistry and Western blot analysis. Neurological dysfunction was observed in all rats with MCAO. In both the model and lipopolysaccharide (LPS) groups, the CIV increased, the neuronal damage in the cortex was more severe, and the number of apoptotic cells and the pERK1/2 expression significantly increased compared with the control group (P < 0.05). In treatment and U0126 groups, the neurological function was improved, the CIV decreased, the neuronal damage in the cortex was attenuated, and the number of apoptotic cells and the pERK1/2 expression significantly decreased compared with the model group (P < 0.05). No significant differences in these indices were observed between model and LPS groups or treatment and U0126 groups (P > 0.05). The results suggest that activation of ERK1/2 in cerebral ischaemia induces neuronal apoptosis and picroside II may reduce neuronal apoptosis to confer protection against cerebral ischemic injury by inhibiting ERK1/2 activation.
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Affiliation(s)
- Tingting Wang
- Institute of Cerebrovascular Diseases, Affiliated Hospital of Qingdao University, Qingdao, China.,Taishan Scholars Construction Project Excellent Innovative Team of Shandong Province, Qingdao, China
| | - Li Zhai
- Institute of Cerebrovascular Diseases, Affiliated Hospital of Qingdao University, Qingdao, China.,Taishan Scholars Construction Project Excellent Innovative Team of Shandong Province, Qingdao, China
| | - Yunliang Guo
- Institute of Cerebrovascular Diseases, Affiliated Hospital of Qingdao University, Qingdao, China.,Taishan Scholars Construction Project Excellent Innovative Team of Shandong Province, Qingdao, China
| | - Haitao Pei
- Institute of Cerebrovascular Diseases, Affiliated Hospital of Qingdao University, Qingdao, China.,Taishan Scholars Construction Project Excellent Innovative Team of Shandong Province, Qingdao, China
| | - Meizeng Zhang
- Institute of Cerebrovascular Diseases, Affiliated Hospital of Qingdao University, Qingdao, China.,Taishan Scholars Construction Project Excellent Innovative Team of Shandong Province, Qingdao, China
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Lee S, Kim JE, Hong SH, Lee AY, Park EJ, Seo HW, Chae C, Doble P, Bishop D, Cho MH. High Inorganic Phosphate Intake Promotes Tumorigenesis at Early Stages in a Mouse Model of Lung Cancer. PLoS One 2015; 10:e0135582. [PMID: 26285136 PMCID: PMC4540575 DOI: 10.1371/journal.pone.0135582] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2014] [Accepted: 07/24/2015] [Indexed: 01/07/2023] Open
Abstract
Inorganic phosphate (Pi) is required by all living organisms for the development of organs such as bone, muscle, brain, and lungs, regulating the expression of several critical genes as well as signal transduction. However, little is known about the effects of prolonged dietary Pi consumption on lung cancer progression. This study investigated the effects of a high-phosphate diet (HPD) in a mouse model of adenocarcinoma. K-rasLA1 mice were fed a normal diet (0.3% Pi) or an HPD (1% Pi) for 1, 2, or 4 months. Mice were then sacrificed and subjected to inductively coupled plasma mass/optical emission spectrometry and laser ablation inductively coupled plasma mass-spectrometry analyses, western blot analysis, histopathological, immunohistochemical, and immunocytochemical analyses to evaluate tumor formation and progression (including cell proliferation, angiogenesis, and apoptosis), changes in ion levels and metabolism, autophagy, epithelial-to-mesenchymal transition, and protein translation in the lungs. An HPD accelerated tumorigenesis, as evidenced by increased adenoma and adenocarcinoma rates as well as tumor size. However, after 4 months of the HPD, cell proliferation was arrested, and marked increases in liver and lung ion levels and in energy production via the tricarboxylic acid cycle in the liver were observed, which were accompanied by increased autophagy and decreased angiogenesis and apoptosis. These results indicate that an HPD initially promotes but later inhibits lung cancer progression because of metabolic adaptation leading to tumor cell quiescence. Moreover, the results suggest that carefully regulated Pi consumption are effective in lung cancer prevention.
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Affiliation(s)
- Somin Lee
- Laboratory of Toxicology, BK21 PLUSProgram for Creative Veterinary Science Research, Research Institute for Veterinary Science and College of Veterinary Medicine, Seoul National University, Seoul, 151–742, Korea
- Graduate Group of Tumor Biology, Seoul National University, Seoul, 151–742, Korea
| | - Ji-Eun Kim
- Laboratory of Toxicology, BK21 PLUSProgram for Creative Veterinary Science Research, Research Institute for Veterinary Science and College of Veterinary Medicine, Seoul National University, Seoul, 151–742, Korea
| | - Seong-Ho Hong
- Laboratory of Toxicology, BK21 PLUSProgram for Creative Veterinary Science Research, Research Institute for Veterinary Science and College of Veterinary Medicine, Seoul National University, Seoul, 151–742, Korea
| | - Ah-Young Lee
- Laboratory of Toxicology, BK21 PLUSProgram for Creative Veterinary Science Research, Research Institute for Veterinary Science and College of Veterinary Medicine, Seoul National University, Seoul, 151–742, Korea
| | - Eun-Jung Park
- Department of Molecular Science and Technology, Ajou University, Suwon, 443–749, Korea
| | - Hwi Won Seo
- Laboratory of Pathology, College of Veterinary Medicine, Seoul National University, Seoul, 151–742, Korea
| | - Chanhee Chae
- Laboratory of Pathology, College of Veterinary Medicine, Seoul National University, Seoul, 151–742, Korea
| | - Philip Doble
- Elemental Bio-imaging Facility, Department of Chemistry and Forensic Science, University of Technology, Sydney, Australia
| | - David Bishop
- Elemental Bio-imaging Facility, Department of Chemistry and Forensic Science, University of Technology, Sydney, Australia
| | - Myung-Haing Cho
- Laboratory of Toxicology, BK21 PLUSProgram for Creative Veterinary Science Research, Research Institute for Veterinary Science and College of Veterinary Medicine, Seoul National University, Seoul, 151–742, Korea
- Graduate School of Convergence Science and Technology, Seoul National University, Suwon, 443–270, Korea
- Graduate Group of Tumor Biology, Seoul National University, Seoul, 151–742, Korea
- Advanced Institute of Convergence Technology, Seoul National University, Suwon, 443–270, Korea
- * E-mail:
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Picroside II Inhibits the MEK-ERK1/2-COX2 Signal Pathway to Prevent Cerebral Ischemic Injury in Rats. J Mol Neurosci 2015; 57:335-51. [PMID: 26240040 DOI: 10.1007/s12031-015-0623-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 07/14/2015] [Indexed: 10/23/2022]
Abstract
The objective of this study is to explore the neuroprotective effect and mechanism of picroside II on ERK1/2-COX2 signal transduction pathway after cerebral ischemic injury in rats. Focal cerebral ischemic models were established by inserting monofilament threads into the middle cerebral artery in 200 Wistar rats. Twenty four rats were randomly selected into control group, while the other rats were randomly divided into six groups: model group, picroside group, lipopolysaccharide (LPS) with picroside group, U0126 with picroside group, LPS group, and U0126 group with each group containing three subgroups with ischemia at 6, 12, and 24 h. Neurobehavioral function in the rats was evaluated by modified neurological severity score points (mNSS) test; structure of neurons was observed using hematoxylin-eosin (HE) staining; apoptotic cells were counted using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay; expressions of phosphorylated mitogen/extracellular signal-regulated kinase kinas1/2 (pMEK1/2), phosphorylated extracellular signal-regulated protein kinase1/2 (pERK1/2), and cyclooxygenase (COX2) in the cortex were determined using immunohistochemistry (IHC) and Western blot (WB); and real-time PCR was used to determine the level of COX2 mRNA. The neurological behavioral malfunction appeared in all rats with middle cerebral artery occlusion (MCAO). In the model group, neuron damage was extensive, while the neurobehavioral function score, apoptotic cell index, expression of pMEK1/2, pERK1/2, and COX2 and the level of COX2 mRNA increased significantly when compared to the control group. The peak COX2 mRNA level was in ischemia 12 h, prior to the peak in COX2 protein expression. In the picroside and U0126 groups, the neurological behavioral function was improved, and the number of apoptotic cells and the expression of pMEK1/2, pERK1/2, and COX2 decreased significantly when compared to the model group. In the LPS with picroside group, at ischemia 6 h neuron damage was extensive, and pMEK1/2, pERK1/2, and COX2 expression were much higher than in the model group. But at ischemia 12 and 24 h, the expression of pMEK1/2, pERK1/2, and COX2 decreased slightly, and the neurobehavioral function also improved slightly. In LPS group, neuron damage was extensive, pMEK1/2, pERK1/2, and COX2 expression was still at a high level, and COX2 mRNA peak arrived at ischemic 12 h. Picroside II downregulates COX2 expression after MCAO by inhibiting MEK-ERK1/2 in rats to protect neurons from apoptosis and inflammation.
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Picroside II Inhibits Neuronal Apoptosis and Improves the Morphology and Structure of Brain Tissue following Cerebral Ischemic Injury in Rats. PLoS One 2015; 10:e0124099. [PMID: 25927985 PMCID: PMC4415915 DOI: 10.1371/journal.pone.0124099] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Accepted: 02/26/2015] [Indexed: 12/29/2022] Open
Abstract
This paper aimed to explore the protective effects of picroside II against the neuronal apoptosis and changes in morphology and structure that follow cerebral ischemic injury in rats. A focal cerebral ischemic model was established by inserting a monofilament thread to achieve middle cerebral artery occlusion (MCAO) in 60 Wistar rats, and intraperitoneal injections of picroside II (20 mg/kg) were administered. The neurobehavioral functions were evaluated with the modified neurological severity score (mNSS) test. The cerebral infarct volumes were measured with tetrazolium chloride (TTC) staining. The morphology and ultrastructure of the cortical brain tissues were observed with hematoxylin-eosin staining and transmission electron microscopy, respectively. The apoptotic cells were counted with terminal deoxynucleotidyl transferase dUTP nick-end labeling and flow cytometry, and pERK1/2 expression was determined by immunohistochemical assay and Western blot. The results indicated that neurological behavioral malfunctions and cerebral infarcts were present in the MCAO rats. In the model group, the damage to the structures of the neurons and the blood brain barrier (BBB) in the cortex was more severe, and the numbers of apoptotic cells, the early apoptotic ratio (EAR) and pERK1/2 expression were significantly increased in this group compared to the control group (P<0.05). In the treatment group, the neurological behavioral function and the morphology and ultrastructure of the neurons and the BBB were improved including the number of Mi increased and relative area of condensed chromosome and basement (BM) thickness descreased, and the cerebral infarct volume, the number of apoptotic cells, the EAR and pERK1/2 expression were significantly decreased compared to the model group (P<0.05). These results suggest that picroside II reduced apoptosis and improved the morphology and ultrastructure of the neurons and the BBB and that these effects resulted in the recovery of the neurobehavioral function of rats with cerebral ischemia.
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Hong SH, Park SJ, Lee S, Kim S, Cho MH. Biological effects of inorganic phosphate: potential signal of toxicity. J Toxicol Sci 2015; 40:55-69. [DOI: 10.2131/jts.40.55] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Seong-Ho Hong
- Laboratory of Toxicology, BK21 PLUS Program for Creative Veterinary Science Research, Research Institute for Veterinary Science and College of Veterinary Medicine, Seoul National University, Korea
| | - Sung-Jin Park
- Laboratory of Toxicology, BK21 PLUS Program for Creative Veterinary Science Research, Research Institute for Veterinary Science and College of Veterinary Medicine, Seoul National University, Korea
| | - Somin Lee
- Graduate Group of Tumor Biology, Seoul National University, Korea
- Laboratory of Toxicology, BK21 PLUS Program for Creative Veterinary Science Research, Research Institute for Veterinary Science and College of Veterinary Medicine, Seoul National University, Korea
| | - Sanghwa Kim
- Graduate Group of Tumor Biology, Seoul National University, Korea
- Laboratory of Toxicology, BK21 PLUS Program for Creative Veterinary Science Research, Research Institute for Veterinary Science and College of Veterinary Medicine, Seoul National University, Korea
| | - Myung-Haing Cho
- Advanced Institute of Convergence Technology, Seoul National University, Korea
- Graduate Group of Tumor Biology, Seoul National University, Korea
- Graduate School of Convergence Science and Technology, Seoul National University, Korea
- Laboratory of Toxicology, BK21 PLUS Program for Creative Veterinary Science Research, Research Institute for Veterinary Science and College of Veterinary Medicine, Seoul National University, Korea
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15
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Wulaningsih W, Van Hemelrijck M, Michaelsson K, Kanarek N, Nelson WG, Ix JH, Platz EA, Rohrmann S. Association of serum inorganic phosphate with sex steroid hormones and vitamin D in a nationally representative sample of men. Andrology 2014; 2:967-76. [PMID: 25270590 PMCID: PMC4324600 DOI: 10.1111/andr.285] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Revised: 08/31/2014] [Accepted: 09/01/2014] [Indexed: 12/14/2022]
Abstract
Defects in bone regulatory pathways have been linked to chronic diseases including cardiovascular disease and cancer. In men, a link between bone metabolism and gonadal hormones has been suggested. However, to date, there is lack of evidence on the association between serum inorganic phosphate (Pi) and sex steroid hormones. The objective of this study was to investigate the association between Pi, sex steroid hormones and a known Pi metabolic regulator, vitamin D, in men in the National Health and Nutrition Examination Survey III (NHANES III). From NHANES III, we selected 1412 men aged 20+ who participated in the morning session of Phase I (1988-1991) with serum measurements of Pi, sex hormones, and vitamin D. Multivariable linear regression was used to calculate crude and geometric mean Pi by total and estimated free testosterone and estradiol, sex hormone-binding globulin, androstanediol glucuronide (AAG), and vitamin D. Similar analyses were performed while stratifying by race/ethnicity and vitamin D levels. We found a lack of statistically significant difference in geometric means of Pi across quintiles of concentrations of sex hormones, indicating a tight regulation of Pi. However, Pi levels were inversely associated with calculated free testosterone in non-Hispanic black men, with geometric mean levels of Pi of 1.16 and 1.02 ng/mL for those in the lowest and highest quintiles of free testosterone, respectively (p-trend < 0.05). A similar but weaker pattern was seen between total testosterone and Pi. An inverse association was also seen between AAG and Pi in men with vitamin D concentration below the median (<24.2 ng/mL). No associations were observed among men with vitamin D levels at or above the median. Our findings suggest a weak link among sex hormones, vitamin D, and Pi in men. The observed effects of race/ethnicity and vitamin D indicate a complex association involving various regulators of Pi homeostasis.
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Affiliation(s)
- W Wulaningsih
- Cancer Epidemiology Unit, Division of Cancer Studies, King's College London, School of Medicine, London, UK
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Camalier CE, Yi M, Yu LR, Hood BL, Conrads KA, Lee YJ, Lin Y, Garneys LM, Bouloux GF, Young MR, Veenstra TD, Stephens RM, Colburn NH, Conrads TP, Beck GR. An integrated understanding of the physiological response to elevated extracellular phosphate. J Cell Physiol 2013; 228:1536-50. [PMID: 23280476 DOI: 10.1002/jcp.24312] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Accepted: 12/11/2012] [Indexed: 12/14/2022]
Abstract
Recent studies have suggested that changes in serum phosphate levels influence pathological states associated with aging such as cancer, bone metabolism, and cardiovascular function, even in individuals with normal renal function. The causes are only beginning to be elucidated but are likely a combination of endocrine, paracrine, autocrine, and cell autonomous effects. We have used an integrated quantitative biology approach, combining transcriptomics and proteomics to define a multi-phase, extracellular phosphate-induced, signaling network in pre-osteoblasts as well as primary human and mouse mesenchymal stromal cells. We identified a rapid mitogenic response stimulated by elevated phosphate that results in the induction of immediate early genes including c-fos. The mechanism of activation requires FGF receptor signaling followed by stimulation of N-Ras and activation of AP-1 and serum response elements. A distinct long-term response also requires FGF receptor signaling and results in N-Ras activation and expression of genes and secretion of proteins involved in matrix regulation, calcification, and angiogenesis. The late response is synergistically enhanced by addition of FGF23 peptide. The intermediate phase results in increased oxidative phosphorylation and ATP production and is necessary for the late response providing a functional link between the phases. Collectively, the results define elevated phosphate, as a mitogen and define specific mechanisms by which phosphate stimulates proliferation and matrix regulation. Our approach provides a comprehensive understanding of the cellular response to elevated extracellular phosphate, functionally connecting temporally coordinated signaling, transcriptional, and metabolic events with changes in long-term cell behavior.
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Affiliation(s)
- Corinne E Camalier
- Division of Endocrinology, Department of Medicine, Emory University, Atlanta, Georgia 30322, USA
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Hong SH, Minai-Tehrani A, Chang SH, Jiang HL, Lee S, Lee AY, Seo HW, Chae C, Beck GR, Cho MH. Knockdown of the sodium-dependent phosphate co-transporter 2b (NPT2b) suppresses lung tumorigenesis. PLoS One 2013; 8:e77121. [PMID: 24194864 PMCID: PMC3806752 DOI: 10.1371/journal.pone.0077121] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Accepted: 08/30/2013] [Indexed: 12/20/2022] Open
Abstract
The sodium-dependent phosphate co-transporter 2b (NPT2b) plays an important role in maintaining phosphate homeostasis. In previous studies, we have shown that high dietary inorganic phosphate (Pi) consumption in mice stimulated lung tumorigenesis and increased NPT2b expression. NPT2b has also been found to be highly expressed in human lung cancer tissues. The association of high expression of NPT2b in the lung with poor prognosis in oncogenic lung diseases prompted us to test whether knockdown of NPT2b may regulate lung cancer growth. To address this issue, aerosols that contained small interfering RNA (siRNA) directed against NPT2b (siNPT2b) were delivered into the lungs of K-ras (LA1) mice, which constitute a murine model reflecting human lung cancer. Our results clearly showed that repeated aerosol delivery of siNPT2b successfully suppressed lung cancer growth and decreased cancer cell proliferation and angiogenesis, while facilitating apoptosis. These results strongly suggest that NPT2b plays a role lung tumorigenesis and represents a novel target for lung cancer therapy.
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Affiliation(s)
- Seong-Ho Hong
- Laboratory of Toxicology, College of Veterinary Medicine, Seoul National University, Seoul, Korea
| | - Arash Minai-Tehrani
- Laboratory of Toxicology, College of Veterinary Medicine, Seoul National University, Seoul, Korea
| | - Seung-Hee Chang
- Laboratory of Toxicology, College of Veterinary Medicine, Seoul National University, Seoul, Korea
| | - Hu-Lin Jiang
- School of Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Somin Lee
- Laboratory of Toxicology, College of Veterinary Medicine, Seoul National University, Seoul, Korea
- Graduate Group of Tumor Biology, Seoul National University, Seoul, Korea
| | - Ah-Young Lee
- Laboratory of Toxicology, College of Veterinary Medicine, Seoul National University, Seoul, Korea
| | - Hwi Won Seo
- Laboratrory of Pathology, College of Veterinary Medicine, Seoul National University, Seoul, Korea
| | - Chanhee Chae
- Laboratrory of Pathology, College of Veterinary Medicine, Seoul National University, Seoul, Korea
| | - George R. Beck
- Division of Endocrinology, Metabolism and Lipids, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Myung-Haing Cho
- Laboratory of Toxicology, College of Veterinary Medicine, Seoul National University, Seoul, Korea
- Graduate School of Convergence Science and Technology, Seoul National University, Suwon, Korea
- Graduate Group of Tumor Biology, Seoul National University, Seoul, Korea
- Advanced Institute of Convergence Technology, Seoul National University, Suwon, Korea
- * E-mail:
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Wulaningsih W, Michaelsson K, Garmo H, Hammar N, Jungner I, Walldius G, Holmberg L, Van Hemelrijck M. Inorganic phosphate and the risk of cancer in the Swedish AMORIS study. BMC Cancer 2013; 13:257. [PMID: 23706176 PMCID: PMC3664604 DOI: 10.1186/1471-2407-13-257] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Accepted: 05/21/2013] [Indexed: 01/08/2023] Open
Abstract
Background Both dietary and serum levels of inorganic phosphate (Pi) have been linked to development of cancer in experimental studies. This is the first population-based study investigating the relation between serum Pi and risk of cancer in humans. Methods From the Swedish Apolipoprotein Mortality Risk (AMORIS) study, we selected all participants (> 20 years old) with baseline measurements of serum Pi, calcium, alkaline phosphatase, glucose, and creatinine (n = 397,292). Multivariable Cox proportional hazards regression analyses were used to assess serum Pi in relation to overall cancer risk. Similar analyses were performed for specific cancer sites. Results We found a higher overall cancer risk with increasing Pi levels in men ( HR: 1.02 (95% CI: 1.00-1.04) for every SD increase in Pi), and a negative association in women (HR: 0.97 (95% CI: 0.96-0.99) for every SD increase in Pi). Further analyses for specific cancer sites showed a positive link between Pi quartiles and the risk of cancer of the pancreas, lung, thyroid gland and bone in men, and cancer of the oesophagus, lung, and nonmelanoma skin cancer in women. Conversely, the risks for developing breast and endometrial cancer as well as other endocrine cancer in both men and women were lower in those with higher Pi levels. Conclusions Abnormal Pi levels are related to development of cancer. Furthermore, the in verse association between Pi levels and risk of breast, endometrial and other endocrine cancers may indicate the role of hormonal factors in the relation between Pi metabolism and cancer.
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Affiliation(s)
- Wahyu Wulaningsih
- King's College London, School of Medicine, Division of Cancer Studies, Cancer Epidemiology Unit, London, UK
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Spina A, Sapio L, Esposito A, Di Maiolo F, Sorvillo L, Naviglio S. Inorganic Phosphate as a Novel Signaling Molecule with Antiproliferative Action in MDA-MB-231 Breast Cancer Cells. Biores Open Access 2013; 2:47-54. [PMID: 23515235 PMCID: PMC3569927 DOI: 10.1089/biores.2012.0266] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Inorganic phosphate (Pi) is an essential nutrient for living organisms. It plays a key role in diverse physiological functions, including osteoblast differentiation and skeletal mineralization. Relevantly, Pi is emerging as an important signaling molecule capable of modulating multiple cellular functions by altering signal transduction pathways, gene expression, and protein abundance in many cell types. To our knowledge, the consequences of elevated Pi on behavior of breast cancer cells have been poorly addressed. In this study we investigate the effects of Pi on proliferation of MDA-MB-231 breast cancer cells. We report that Pi inhibits proliferation of MDA-MB-231 cells by slowing cell cycle progression, without apoptosis occurrence. We found that Pi causes cells to accumulate in G1 phase in a time-dependent manner. Accordingly, G1 accumulation was associated with a decrease of cyclin A and cyclin E and an increase of cell cycle inhibitors p21 and p27 protein levels, respectively. Moreover, the Pi-induced antiproliferative effect was dynamically accompanied by profound changes in ERK1/2 and STAT3 protein and phosphorylation levels in response to Pi. Altogether, our data represent the first evidence of Pi acting as a novel signaling molecule in MDA-MB-231 breast cancer cells, capable of eliciting a strong antiproliferative action and suggest that targeting Pi levels at local sites might represent the rationale for developing novel strategies for therapeutic intervention in triple-negative breast cancer.
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Affiliation(s)
- Annamaria Spina
- Department of Biochemistry and Biophysics, Medical School, Second University of Naples , Naples, Italy
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Khoshniat S, Bourgine A, Julien M, Weiss P, Guicheux J, Beck L. The emergence of phosphate as a specific signaling molecule in bone and other cell types in mammals. Cell Mol Life Sci 2011; 68:205-18. [PMID: 20848155 PMCID: PMC11114507 DOI: 10.1007/s00018-010-0527-z] [Citation(s) in RCA: 116] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2010] [Revised: 08/02/2010] [Accepted: 08/31/2010] [Indexed: 02/07/2023]
Abstract
Although considerable advances in our understanding of the mechanisms of phosphate homeostasis and skeleton mineralization have recently been made, little is known about the initial events involving the detection of changes in the phosphate serum concentrations and the subsequent downstream regulation cascade. Recent data has strengthened a long-established hypothesis that a phosphate-sensing mechanism may be present in various organs. Such a phosphate sensor would detect changes in serum or local phosphate concentration and would inform the body, the local environment, or the individual cell. This suggests that phosphate in itself could represent a signal regulating multiple factors necessary for diverse biological processes such as bone or vascular calcification. This review summarizes findings supporting the possibility that phosphate represents a signaling molecule, particularly in bone and cartilage, but also in other tissues. The involvement of various signaling pathways (ERK1/2), transcription factors (Fra-1, Runx2) and phosphate transporters (PiT1, PiT2) is discussed.
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Affiliation(s)
- Solmaz Khoshniat
- Group STEP (Skeletal Tissue Engineering and Physiopathology), Centre for Osteoarticular and Dental Tissue Engineering (LIOAD), INSERM, U791, 44042 Nantes, France
- UFR Odontologie, Pres UNAM, 44042 Nantes, France
| | - Annabelle Bourgine
- Group STEP (Skeletal Tissue Engineering and Physiopathology), Centre for Osteoarticular and Dental Tissue Engineering (LIOAD), INSERM, U791, 44042 Nantes, France
- UFR Odontologie, Pres UNAM, 44042 Nantes, France
| | - Marion Julien
- Group STEP (Skeletal Tissue Engineering and Physiopathology), Centre for Osteoarticular and Dental Tissue Engineering (LIOAD), INSERM, U791, 44042 Nantes, France
- UFR Odontologie, Pres UNAM, 44042 Nantes, France
| | - Pierre Weiss
- Group STEP (Skeletal Tissue Engineering and Physiopathology), Centre for Osteoarticular and Dental Tissue Engineering (LIOAD), INSERM, U791, 44042 Nantes, France
- UFR Odontologie, Pres UNAM, 44042 Nantes, France
| | - Jérôme Guicheux
- Group STEP (Skeletal Tissue Engineering and Physiopathology), Centre for Osteoarticular and Dental Tissue Engineering (LIOAD), INSERM, U791, 44042 Nantes, France
- UFR Odontologie, Pres UNAM, 44042 Nantes, France
| | - Laurent Beck
- Growth and Signalling Research Center, INSERM, U845, 75015 Paris, France
- Faculté de Médecine, Centre de Recherche, INSERM U845, Université Paris Descartes, 156 Rue de Vaugirard, 75015 Paris, France
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Xu CX, Jin H, Lim HT, Ha YC, Chae CH, An GH, Lee KH, Cho MH. Low dietary inorganic phosphate stimulates lung tumorigenesis through altering protein translation and cell cycle in K-ras(LA1) mice. Nutr Cancer 2010; 62:525-32. [PMID: 20432174 DOI: 10.1080/01635580903532432] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Recent surveys indicate that Pi intake has increased steadily as Pi-containing foods have increased. Our previous study demonstrated that high dietary Pi strongly stimulated lung tumorigeneis. In order to answer the issue whether low Pi may be chemopreventive, we examined the effects of low Pi on lung cancer. Eighteen 5-wk-old male K-ras(LA1) lung cancer model mice were randomly allocated to 2 groups. One group was fed a normal diet (0.5% Pi) and other group was fed low Pi (0.1% Pi) diet for 4 wk. Lung cancer development was evaluated by histopathological examination, Western blot, kinase assay, and immunohistochemistry. Low Pi increased the expression of sodium-dependent phosphate co-transporter 2b, and activated Akt signal with decreased PTEN expression in the lungs of K-ras(LA1) mice. Low Pi increased the Akt/mTOR-mediated protein translation through upregulating the phosphorylation of p70S6K and 4E-BP1. In addition, low Pi stimulated cell cycling as evidenced by altered cell cycle regulators such as cyclin D1 and D3. Finally, low Pi increased lung tumorigenesis in K-ras(LA1) mice compared to the normal diet group. Our results clearly demonstrated that low Pi also promoted lung tumorigenesis, thus suggesting that an appropriate intake of dietary Pi may be critical for lung cancer prevention as well as treatment.
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Jin H, Xu CX, Lim HT, Park SJ, Shin JY, Chung YS, Park SC, Chang SH, Youn HJ, Lee KH, Lee YS, Ha YC, Chae CH, Beck GR, Cho MH. High dietary inorganic phosphate increases lung tumorigenesis and alters Akt signaling. Am J Respir Crit Care Med 2009; 179:59-68. [PMID: 18849498 PMCID: PMC2615662 DOI: 10.1164/rccm.200802-306oc] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2008] [Accepted: 10/09/2008] [Indexed: 02/07/2023] Open
Abstract
RATIONALE Phosphate (Pi) is an essential nutrient to living organisms. Recent surveys indicate that the intake of Pi has increased steadily. Our previous studies have indicated that elevated Pi activates the Akt signaling pathway. An increased knowledge of the response of lung cancer tissue to high dietary Pi may provide an important link between diet and lung tumorigenesis. OBJECTIVES The current study was performed to elucidate the potential effects of high dietary Pi on lung cancer development. METHODS Experiments were performed on 5-week-old male K-ras(LA1) lung cancer model mice and 6-week-old male urethane-induced lung cancer model mice. Mice were fed a diet containing 0.5% Pi (normal Pi) and 1.0% Pi (high Pi) for 4 weeks. At the end of the experiment, all mice were killed. Lung cancer development was evaluated by diverse methods. MEASUREMENT AND MAIN RESULTS A diet high in Pi increased lung tumor progression and growth compared with normal diet. High dietary Pi increased the sodium-dependent inorganic phosphate transporter-2b protein levels in the lungs. High dietary consumption of Pi stimulated pulmonary Akt activity while suppressing the protein levels of tumor suppressor phosphatase and tensin homolog deleted on chromosome 10 as well as Akt binding partner carboxyl-terminal modulator protein, resulting in facilitated cap-dependent protein translation. In addition, high dietary Pi significantly stimulated cell proliferation in the lungs of K-ras(LA1) mice. CONCLUSIONS Our results showed that high dietary Pi promoted tumorigenesis and altered Akt signaling, thus suggesting that careful regulation of dietary Pi may be critical for lung cancer prevention as well as treatment.
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Affiliation(s)
- Hua Jin
- Laboratory of Toxicology, College of Veterinary Medicine, Seoul National University, Seoul, Korea
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Xu CX, Jin H, Lim HT, Kim JE, Shin JY, Lee ES, Chung YS, Lee YS, Beck G, Lee KH, Cho MH. High dietary inorganic phosphate enhances cap-dependent protein translation, cell-cycle progression, and angiogenesis in the livers of young mice. Am J Physiol Gastrointest Liver Physiol 2008; 295:G654-63. [PMID: 18703640 PMCID: PMC2575911 DOI: 10.1152/ajpgi.90213.2008] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Inorganic phosphate (P(i)) plays a key role in diverse physiological functions. Recent studies have indicated that P(i) affects Akt signaling through the sodium-dependent phosphate cotransporter. Akt signaling, in turn, plays an important role in liver development; however, the effects of high dietary P(i) on the liver have not been investigated. Here, we examined the effects of high dietary phosphate on the liver in developing mice. We found that high dietary P(i) increased liver mass through enhancing Akt-related cap-dependent protein translation, cell cycle progression, and angiogenesis. Thus careful regulation of P(i) consumption may be important in maintaining normal development of the liver.
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Affiliation(s)
- Cheng-Xiong Xu
- Laboratory of Toxicology, College of Veterinary Medicine, Nano Systems Institute-National Core Research Center, Department of Food and Nutrition, College of Human Ecology, Seoul National University, Seoul, Korea; Division of Endocrinology, Metabolism, and Lipids, Emory University School of Medicine, Atlanta, Georgia; Laboratory of Radiation Molecular Oncology, Korea Institute of Radiological & Medical Sciences, Seoul, Korea; Center for Developmental Pharmacology and Toxicology, Seattle Children's Hospital Research Institute, Seattle, Washington; and National Institute of Toxicological Research, Korea Food and Drug Administration, Seoul, Korea
| | - Hua Jin
- Laboratory of Toxicology, College of Veterinary Medicine, Nano Systems Institute-National Core Research Center, Department of Food and Nutrition, College of Human Ecology, Seoul National University, Seoul, Korea; Division of Endocrinology, Metabolism, and Lipids, Emory University School of Medicine, Atlanta, Georgia; Laboratory of Radiation Molecular Oncology, Korea Institute of Radiological & Medical Sciences, Seoul, Korea; Center for Developmental Pharmacology and Toxicology, Seattle Children's Hospital Research Institute, Seattle, Washington; and National Institute of Toxicological Research, Korea Food and Drug Administration, Seoul, Korea
| | - Hwang-Tae Lim
- Laboratory of Toxicology, College of Veterinary Medicine, Nano Systems Institute-National Core Research Center, Department of Food and Nutrition, College of Human Ecology, Seoul National University, Seoul, Korea; Division of Endocrinology, Metabolism, and Lipids, Emory University School of Medicine, Atlanta, Georgia; Laboratory of Radiation Molecular Oncology, Korea Institute of Radiological & Medical Sciences, Seoul, Korea; Center for Developmental Pharmacology and Toxicology, Seattle Children's Hospital Research Institute, Seattle, Washington; and National Institute of Toxicological Research, Korea Food and Drug Administration, Seoul, Korea
| | - Ji-Eun Kim
- Laboratory of Toxicology, College of Veterinary Medicine, Nano Systems Institute-National Core Research Center, Department of Food and Nutrition, College of Human Ecology, Seoul National University, Seoul, Korea; Division of Endocrinology, Metabolism, and Lipids, Emory University School of Medicine, Atlanta, Georgia; Laboratory of Radiation Molecular Oncology, Korea Institute of Radiological & Medical Sciences, Seoul, Korea; Center for Developmental Pharmacology and Toxicology, Seattle Children's Hospital Research Institute, Seattle, Washington; and National Institute of Toxicological Research, Korea Food and Drug Administration, Seoul, Korea
| | - Ji-Young Shin
- Laboratory of Toxicology, College of Veterinary Medicine, Nano Systems Institute-National Core Research Center, Department of Food and Nutrition, College of Human Ecology, Seoul National University, Seoul, Korea; Division of Endocrinology, Metabolism, and Lipids, Emory University School of Medicine, Atlanta, Georgia; Laboratory of Radiation Molecular Oncology, Korea Institute of Radiological & Medical Sciences, Seoul, Korea; Center for Developmental Pharmacology and Toxicology, Seattle Children's Hospital Research Institute, Seattle, Washington; and National Institute of Toxicological Research, Korea Food and Drug Administration, Seoul, Korea
| | - Eun-Sun Lee
- Laboratory of Toxicology, College of Veterinary Medicine, Nano Systems Institute-National Core Research Center, Department of Food and Nutrition, College of Human Ecology, Seoul National University, Seoul, Korea; Division of Endocrinology, Metabolism, and Lipids, Emory University School of Medicine, Atlanta, Georgia; Laboratory of Radiation Molecular Oncology, Korea Institute of Radiological & Medical Sciences, Seoul, Korea; Center for Developmental Pharmacology and Toxicology, Seattle Children's Hospital Research Institute, Seattle, Washington; and National Institute of Toxicological Research, Korea Food and Drug Administration, Seoul, Korea
| | - Youn-Sun Chung
- Laboratory of Toxicology, College of Veterinary Medicine, Nano Systems Institute-National Core Research Center, Department of Food and Nutrition, College of Human Ecology, Seoul National University, Seoul, Korea; Division of Endocrinology, Metabolism, and Lipids, Emory University School of Medicine, Atlanta, Georgia; Laboratory of Radiation Molecular Oncology, Korea Institute of Radiological & Medical Sciences, Seoul, Korea; Center for Developmental Pharmacology and Toxicology, Seattle Children's Hospital Research Institute, Seattle, Washington; and National Institute of Toxicological Research, Korea Food and Drug Administration, Seoul, Korea
| | - Yeon-Sook Lee
- Laboratory of Toxicology, College of Veterinary Medicine, Nano Systems Institute-National Core Research Center, Department of Food and Nutrition, College of Human Ecology, Seoul National University, Seoul, Korea; Division of Endocrinology, Metabolism, and Lipids, Emory University School of Medicine, Atlanta, Georgia; Laboratory of Radiation Molecular Oncology, Korea Institute of Radiological & Medical Sciences, Seoul, Korea; Center for Developmental Pharmacology and Toxicology, Seattle Children's Hospital Research Institute, Seattle, Washington; and National Institute of Toxicological Research, Korea Food and Drug Administration, Seoul, Korea
| | - George Beck
- Laboratory of Toxicology, College of Veterinary Medicine, Nano Systems Institute-National Core Research Center, Department of Food and Nutrition, College of Human Ecology, Seoul National University, Seoul, Korea; Division of Endocrinology, Metabolism, and Lipids, Emory University School of Medicine, Atlanta, Georgia; Laboratory of Radiation Molecular Oncology, Korea Institute of Radiological & Medical Sciences, Seoul, Korea; Center for Developmental Pharmacology and Toxicology, Seattle Children's Hospital Research Institute, Seattle, Washington; and National Institute of Toxicological Research, Korea Food and Drug Administration, Seoul, Korea
| | - Kee Ho Lee
- Laboratory of Toxicology, College of Veterinary Medicine, Nano Systems Institute-National Core Research Center, Department of Food and Nutrition, College of Human Ecology, Seoul National University, Seoul, Korea; Division of Endocrinology, Metabolism, and Lipids, Emory University School of Medicine, Atlanta, Georgia; Laboratory of Radiation Molecular Oncology, Korea Institute of Radiological & Medical Sciences, Seoul, Korea; Center for Developmental Pharmacology and Toxicology, Seattle Children's Hospital Research Institute, Seattle, Washington; and National Institute of Toxicological Research, Korea Food and Drug Administration, Seoul, Korea
| | - Myung-Haing Cho
- Laboratory of Toxicology, College of Veterinary Medicine, Nano Systems Institute-National Core Research Center, Department of Food and Nutrition, College of Human Ecology, Seoul National University, Seoul, Korea; Division of Endocrinology, Metabolism, and Lipids, Emory University School of Medicine, Atlanta, Georgia; Laboratory of Radiation Molecular Oncology, Korea Institute of Radiological & Medical Sciences, Seoul, Korea; Center for Developmental Pharmacology and Toxicology, Seattle Children's Hospital Research Institute, Seattle, Washington; and National Institute of Toxicological Research, Korea Food and Drug Administration, Seoul, Korea
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24
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Jin H, Chang SH, Xu CX, Shin JY, Chung YS, Park SJ, Lee YS, An GH, Lee KH, Cho MH. High dietary inorganic phosphate affects lung through altering protein translation, cell cycle, and angiogenesis in developing mice. Toxicol Sci 2007; 100:215-23. [PMID: 17698515 DOI: 10.1093/toxsci/kfm202] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Inorganic phosphate (Pi) plays a key role in diverse physiological functions. Several studies indicate that Pi may affect lung cell development through Na/Pi cotransporter (NPT). Several NPT subtypes have been identified in mammalian lung, and considerable progress has been made in our understanding of their function and regulation. Therefore, current study was performed to elucidate the potential effects of high dietary Pi on lungs of developing mice. Our results clearly demonstrate that high dietary Pi may affect the lung of developing mice through Akt-related cap-dependent protein translation, cell cycle regulation, and angiogenesis. Our results support the hypothesis that Pi works as a critical signal molecule for normal lung growth and suggest that careful restriction of Pi consumption may be important in maintaining a normal development.
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Affiliation(s)
- Hua Jin
- Laboratory of Toxicology, College of Veterinary Medicine, Seoul National University, Seoul 151-742, Korea
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25
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Jin H, Hwang SK, Kwon JT, Lee YS, An GH, Lee KH, Prats AC, Morello D, Beck GR, Cho MH. Low dietary inorganic phosphate affects the brain by controlling apoptosis, cell cycle and protein translation. J Nutr Biochem 2007; 19:16-25. [PMID: 17509857 DOI: 10.1016/j.jnutbio.2006.12.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2006] [Revised: 12/14/2006] [Accepted: 12/20/2006] [Indexed: 01/01/2023]
Abstract
Inorganic phosphate (Pi) plays a key role in diverse physiologic functions. In a previous study, we showed that high dietary Pi perturbs brain growth through Akt/ERK signaling in developing mice. However, no study has investigated the response of the brain to low dietary Pi. In this study, we addressed this question by studying the effects of low dietary Pi on the cerebrum of developing mice. Two-week-old weaned mice were fed with a low phosphate diet for 4 weeks. At the end of the study, their cerebrum was dissected and signals important for protein translation, apoptosis and cell cycle were examined. The low phosphate diet did not cause physiologically significant changes; it increased the protein expression of phosphatase and tensin homolog deleted on chromosome 10 but decreased Akt activity. In addition, expression of eukaryotic translation initiation factor binding protein coupled with increased complex formation of eukaryotic translation initiation factor 4E/eukaryotic translation initiation factor binding protein 1 was induced in the cerebrum by low phosphate, leading to reduced cap-dependent protein translation. Finally, low phosphate facilitated apoptosis and suppressed signals important for the cell cycle in the cerebrum of dual-luciferase reporter mice. In summary, our results showed that a low phosphate diet affects the brain by controlling protein translation, apoptosis and cell cycle in developing mice. Our results support the hypothesis that Pi works as a stimulus capable of increasing or decreasing several pivotal genes for normal development and suggest that regulation of Pi consumption is important in maintaining a healthy life.
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Affiliation(s)
- Hua Jin
- Laboratory of Toxicology, College of Veterinary Medicine and BK21 Program for Veterinary Science, Seoul National University, Seoul 151-742, South Korea
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26
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Jepson MA, Davis MJ, Horton AA, Walker DG. Histochemical and biochemical observations on the cytotoxicity of paracetamol and its effects on glycogen metabolism in rat liver. Toxicology 1988; 54:926-34. [PMID: 3424388 DOI: 10.1002/mc.22153] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Revised: 01/20/2014] [Accepted: 03/06/2014] [Indexed: 12/14/2022]
Abstract
The effects of paracetamol overdose on glycogen metabolism in rat liver have been investigated and related to its cytotoxicity. Paracetamol was administered to male rats by gavaging after a 24-h fast and refeeding was not permitted. An early (9-12-h) increase in histochemically demonstrable glycogen phosphorylase alpha activity in perivenous hepatocytes preceded major loss of membrane integrity as assessed by serum glutamate-pyruvate transaminase (SGPT) activity and uptake of trypan blue during perfusion. These changes occurred only after a decrease in the concentration of reduced glutathione, which is generally observed about 4 h after paracetamol treatment. The activation of glycogen phosphorylase in perivenous hepatocytes occurred concurrently with an increase in glycogen content of periportal hepatocytes, indicating a clear heterogeneity in the response of the two-cell populations to the hepatotoxin. The use of trypan blue perfusion together with histochemical techniques allowed changes in glycogen content and phosphorylase alpha activity of individual hepatocytes to be assessed with reference to the extent of membrane damage evident. The relevance of the results to possible mechanisms of hepatotoxicity is discussed.
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Affiliation(s)
- M A Jepson
- Department of Biochemistry, University of Birmingham, U.K
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