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Imamori M, Hosooka T, Imi Y, Hosokawa Y, Yamaguchi K, Itoh Y, Ogawa W. Thrombospondin-1 promotes liver fibrosis by enhancing TGF-β action in hepatic stellate cells. Biochem Biophys Res Commun 2024; 693:149369. [PMID: 38091840 DOI: 10.1016/j.bbrc.2023.149369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2023] [Revised: 11/27/2023] [Accepted: 12/05/2023] [Indexed: 01/10/2024]
Abstract
Insulin resistance in adipose tissue is thought to be a key contributor to the pathogenesis of various metabolic disorders including metabolic dysfunction-associated steatotic liver disease/metabolic dysfunction-associated steatohepatitis (MASLD/MASH), but the mechanism underlying this contribution to MASLD/MASH has remained unknown. We previously showed that dysregulation of the PDK1-FoxO1 signaling axis in adipocytes plays a role in the development of MASLD/MASH by analysis of adipocyte-specific PDK1 knockout (A-PDK1KO) and adipocyte-specific PDK1/FoxO1 double-knockout (A-PDK1/FoxO1DKO) mice. We here focused on the role of the extracellular matrix protein thrombospondin-1 (TSP-1) as a secreted factor whose expression in adipose tissue is increased in A-PDK1KO mice and normalized in A-PDK1/FoxO1DKO mice. Genetic ablation of TSP-1 markedly ameliorated liver fibrosis in A-PDK1KO mice fed a high-fat diet. With regard to the potential mechanism of this effect, TSP-1 augmented the expression of fibrosis-related genes induced by TGF-β in LX-2 human hepatic stellate cells. We also showed that TSP-1 expression and secretion were negatively regulated by insulin signaling via the PDK1-FoxO1 axis in cultured adipocytes. Our results thus indicate that TSP-1 plays a key role in the pathogenesis of liver fibrosis in MASH. Regulation of TSP-1 expression by PDK1-FoxO1 axis in adipocytes may provide a basis for targeted therapy of hepatic fibrosis in individuals with MASH.
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Affiliation(s)
- Makoto Imamori
- Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Hyogo, 650-0017, Japan
| | - Tetsuya Hosooka
- Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Hyogo, 650-0017, Japan; Laboratory of Nutritional Physiology, Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, Suruga-ku, Shizuoka, 422-8526, Japan.
| | - Yukiko Imi
- Laboratory of Nutritional Physiology, Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, Suruga-ku, Shizuoka, 422-8526, Japan
| | - Yusei Hosokawa
- Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Hyogo, 650-0017, Japan
| | - Kanji Yamaguchi
- Division of Molecular Gastroenterology and Hepatology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kamigyo-ku, Kyoto, 602-8566, Japan
| | - Yoshito Itoh
- Division of Molecular Gastroenterology and Hepatology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kamigyo-ku, Kyoto, 602-8566, Japan
| | - Wataru Ogawa
- Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Hyogo, 650-0017, Japan
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Kasahara N, Imi Y, Amano R, Shinohara M, Okada K, Hosokawa Y, Imamori M, Tomimoto C, Kunisawa J, Kishino S, Ogawa J, Ogawa W, Hosooka T. A gut microbial metabolite of linoleic acid ameliorates liver fibrosis by inhibiting TGF-β signaling in hepatic stellate cells. Sci Rep 2023; 13:18983. [PMID: 37923895 PMCID: PMC10624680 DOI: 10.1038/s41598-023-46404-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Accepted: 10/31/2023] [Indexed: 11/06/2023] Open
Abstract
The antidiabetic drug pioglitazone ameliorates insulin resistance by activating the transcription factor PPARγ. In addition to its blood glucose-lowering action, pioglitazone exerts pleiotropic effects including amelioration of nonalcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH). The mechanism by which pioglitazone achieves this latter effect has remained unclear, however. We here show that pioglitazone administration increases the amount of linoleic acid (LA) metabolites in adipose tissue of KK-Ay mice. These metabolites are produced by lactic acid bacteria in the gut, and pioglitazone also increased the fraction of Lactobacillus in the gut microbiota. Administration of the LA metabolite HYA (10-hydroxy-cis-12-octadecenoic acid) to C57BL/6 J mice fed a high-fat diet improved liver histology including steatosis, inflammatory cell infiltration, and fibrosis. Gene ontology analysis of RNA-sequencing data for the liver revealed that the top category for genes downregulated by HYA treatment was related to extracellular matrix, and the expression of individual genes related to fibrosis was confirmed to be attenuated by HYA treatment. Mechanistically, HYA suppressed TGF-β-induced Smad3 phosphorylation and fibrosis-related gene expression in human hepatic stellate cells (LX-2). Our results implicate LA metabolites in the mechanism by which pioglitazone ameliorates liver fibrosis, and they suggest that HYA is a potential therapeutic for NAFLD/NASH.
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Affiliation(s)
- Nanaho Kasahara
- Laboratory of Nutritional Physiology, Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, 52-1 Yada, Suruga-Ku, Shizuoka, 422-8526, Japan
| | - Yukiko Imi
- Laboratory of Nutritional Physiology, Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, 52-1 Yada, Suruga-Ku, Shizuoka, 422-8526, Japan
| | - Reina Amano
- Laboratory of Nutritional Physiology, Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, 52-1 Yada, Suruga-Ku, Shizuoka, 422-8526, Japan
| | - Masakazu Shinohara
- Division of Molecular Epidemiology, Department of Future Medicine Sciences, Kobe University Graduate School of Medicine, Kobe, Hyogo, 650-0017, Japan
- The Integrated Center for Mass Spectrometry, Kobe University Graduate School of Medicine, Kobe, Hyogo, 650-0017, Japan
| | - Kumiko Okada
- Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Hyogo, 650-0017, Japan
| | - Yusei Hosokawa
- Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Hyogo, 650-0017, Japan
| | - Makoto Imamori
- Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Hyogo, 650-0017, Japan
| | | | - Jun Kunisawa
- Laboratory of Vaccine Materials and Laboratory of Gut Environmental System, Microbial Research Center for Health and Medicine, National Institutes of Biomedical Innovation, Health, and Nutrition (NIBIOHN), Osaka, 567-0085, Japan
| | - Shigenobu Kishino
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-Ku, Kyoto, 606-8502, Japan
| | - Jun Ogawa
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-Ku, Kyoto, 606-8502, Japan
| | - Wataru Ogawa
- Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Hyogo, 650-0017, Japan
| | - Tetsuya Hosooka
- Laboratory of Nutritional Physiology, Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, 52-1 Yada, Suruga-Ku, Shizuoka, 422-8526, Japan.
- Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Hyogo, 650-0017, Japan.
- Laboratory of Vaccine Materials and Laboratory of Gut Environmental System, Microbial Research Center for Health and Medicine, National Institutes of Biomedical Innovation, Health, and Nutrition (NIBIOHN), Osaka, 567-0085, Japan.
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Imi Y, Amano R, Kasahara N, Obana Y, Hosooka T. Nicotinamide mononucleotide induces lipolysis by regulating ATGL expression via the SIRT1-AMPK axis in adipocytes. Biochem Biophys Rep 2023; 34:101476. [PMID: 37144119 PMCID: PMC10151261 DOI: 10.1016/j.bbrep.2023.101476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 04/19/2023] [Accepted: 04/21/2023] [Indexed: 05/06/2023] Open
Abstract
Nicotinamide adenine dinucleotide (NAD+) -dependent protein deacetylase SIRT1 plays an important role in the regulation of metabolism. Although the administration of nicotinamide mononucleotide (NMN), a key NAD+ intermediate, has been shown to ameliorate metabolic disorders, such as insulin resistance and glucose intolerance, the direct effect of NMN on the regulation of lipid metabolism in adipocytes remains unclear. We here investigated the effect of NMN on lipid storage in 3T3-L1 differentiated adipocytes. Oil-red O staining showed that NMN treatment reduced lipid accumulation in these cells. NMN was found to enhance lipolysis in adipocytes since the concentration of glycerol in the media was increased by NMN treatment. Western blotting and real-time RT-PCR analysis revealed that adipose triglyceride lipase (ATGL) expression at both protein and mRNA level was increased with NMN treatment in 3T3-L1 adipocytes. Whereas NMN increased SIRT1 expression and AMPK activation, an AMPK inhibitor compound C restored the NMN-dependent upregulation of ATGL expression in these cells, suggesting that NMN upregulates ATGL expression through the SIRT1-AMPK axis. NMN administration significantly decreased subcutaneous fat mass in mice on a high-fat diet. We also found that adipocyte size in subcutaneous fat was decreased with NMN treatment. Consistent with the alteration of fat mass and adipocyte size, the ATGL expression in subcutaneous fat was slightly, albeit significantly, increased with NMN treatment. These results indicate that NMN suppresses subcutaneous fat mass in diet-induced obese mice, potentially in part via the upregulation of ATGL. Unexpectedly, the reduction in fat mass as well as ATGL upregulation with NMN treatment were not observed in epididymal fat, implying that the effects of NMN are site-specific in adipose tissue. Thus, these findings provide important insights into the mechanism of NMN/NAD+ in the regulation of metabolism.
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Abstract
Adipose tissue regulates systemic energy metabolism through adipokine production as well as energy storage and energy supply to other organs in response to changes in energy status. Adipose tissue dysfunction is therefore thought to be a key contributor to the pathogenesis of a variety of metabolic disorders including nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH). Given that insulin plays a central role in the regulation of many aspects of adipocyte function, insulin resistance in adipose tissue is implicated in the pathogenesis of metabolic disorders as a cause of adipose tissue dysfunction. The concept of metabolic dysfunction-associated fatty liver disease (MAFLD) has recently been proposed for liver disease associated with metabolic disorders in both obese and nonobese individuals, with insulin resistance in adipose tissue likely being an important factor in its pathogenesis. This review outlines the relation between insulin resistance in adipose tissue and metabolic disorders, with a focus on the physiological relevance and mechanism of action of 3'-phosphoinositide-dependent kinase 1 (PDK1), a key kinase in insulin signaling, and its downstream transcription factor FoxO1 in adipocytes.
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Affiliation(s)
- Yukiko Imi
- Laboratory of Nutritional Physiology, School of Food and Nutritional Sciences/Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, 52-1 Yada, Suruga-Ku, Shizuoka, 422-8526 Japan
| | - Wataru Ogawa
- Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-Cho, Chuo-Ku, Kobe, 650-0017 Japan
| | - Tetsuya Hosooka
- Laboratory of Nutritional Physiology, School of Food and Nutritional Sciences/Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, 52-1 Yada, Suruga-Ku, Shizuoka, 422-8526 Japan
- Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-Cho, Chuo-Ku, Kobe, 650-0017 Japan
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Yoshioka Y, Imi Y, Kawabata K, Shibata K, Terao J, Miyoshi N. Theophylline Prevents Dexamethasone-Induced Atrophy in C2C12 Myotubes. J Nutr Sci Vitaminol (Tokyo) 2023; 69:284-291. [PMID: 37648515 DOI: 10.3177/jnsv.69.284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
Abstract
Skeletal muscle mass is maintained by a balance between the synthesis and degradation of muscle proteins, the collapse of which causes muscle wasting. The prevention of muscle wasting improves the quality of life and extends a healthy life. The methyl xanthine theophylline showed strong preventive activity against dexamethasone-induced muscle atrophy, as determined using the expression level of myosin heavy chain in C2C12 myotubes. Mechanistically, theophylline inhibited the expression of ubiquitin ligases MuRF1 and Cbl-b, but not that of atrogin-1. Furthermore, theophylline inhibits glucocorticoid receptor translocation to the nucleus. A pull-down assay using a theophylline probe revealed that theophylline and dexamethasone competitively interacted with the glucocorticoid receptor, suggesting an antagonistic activity of theophylline on glucocorticoid receptors. Additionally, theophylline inhibited the dexamethasone-induced phosphorylation of p38 and FoxO3a in C2C12 myotubes. These findings suggest that theophylline is an effective food ingredient in the prevention of glucocorticoid-induced skeletal muscle atrophy.
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Affiliation(s)
- Yasukiyo Yoshioka
- Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka
| | - Yukiko Imi
- Faculty of Clinical Nutrition and Dietetics, Konan Women's University
| | - Kyuichi Kawabata
- Faculty of Clinical Nutrition and Dietetics, Konan Women's University
| | - Katsumi Shibata
- Faculty of Clinical Nutrition and Dietetics, Konan Women's University
| | - Junji Terao
- Faculty of Clinical Nutrition and Dietetics, Konan Women's University
| | - Noriyuki Miyoshi
- Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka
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Imi Y, Shibata K. Nutritional Factors That Affect the Formation of 5-Aminolevulinic Acid, a Key Intermediate of Heme Biosynthesis. J Nutr Sci Vitaminol (Tokyo) 2021; 67:339-350. [PMID: 34719620 DOI: 10.3177/jnsv.67.339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
5-Aminolevulinic acid (ALA) is a key intermediate of heme biosynthesis, which is an essential component of the respiratory chain. Therefore, nutrients that affect ALA biosynthesis eventually affect ATP production, which is the basis of mitochondrial function. Although the effects of various non-nutrient components that affect ALA after biosynthesis have been reported, there are few reports on the effects of dietary amino acids/protein on ALA formation and the effects of dietary vitamins that are involved in amino acid metabolism. In mitochondria, ALA is synthesized from succinyl-CoA and glycine by the pyridoxal phosphate-dependent enzyme ALA synthase [EC 2.3.1.37]. In this study, the effects of dietary amino acids/protein and vitamins on the amount of ALA synthesized were investigated using mice, rats, and cultured cells. Amounts of ALA in plasma and urine, and porphyrins in plasma increased with increasing protein intake. Vitamin B1 insufficiency did not affect ALA synthesis. Vitamin B6 insufficiency increased the amount of ALA synthesized, while niacin deficiency markedly reduced ALA synthesis. Thus, for heme synthesis, an essential biological substance for life, the amounts of amino acids, as well as the pathways metabolizing amino acids to glycine and succinyl-CoA are very important. Specifically, it is important that niacin is associated with the formation of glycine and succinyl-CoA from amino acids.
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Affiliation(s)
- Yukiko Imi
- Department of Clinical Nutrition and Dietetics, Faculty of Clinical Nutrition and Dietetics, Konan Women's University
| | - Katsumi Shibata
- Department of Clinical Nutrition and Dietetics, Faculty of Clinical Nutrition and Dietetics, Konan Women's University.,Department of Nutrition, School of Human Cultures, The University of Shiga Prefecture
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Fukuda-Tatano S, Yamamoto H, Nakahashi O, Yoshikawa R, Hayashi M, Kishimoto M, Imi Y, Yamanaka-Okumura H, Ohnishi K, Masuda M, Taketani Y. Regulation of α-Klotho Expression by Dietary Phosphate During Growth Periods. Calcif Tissue Int 2019; 104:667-678. [PMID: 30671592 DOI: 10.1007/s00223-019-00525-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 01/14/2019] [Indexed: 02/06/2023]
Abstract
Inorganic phosphate (Pi) is an essential nutrient for maintaining various biological functions, particularly during growth periods. Excess intake of dietary Pi increases the secretion of fibroblast growth factor 23 (FGF23) and parathyroid hormone to maintain plasma Pi levels. FGF23 is a potent phosphaturic factor that binds to the α-klotho/FGFR complex in the kidney to promote excretion of Pi into the urine. In addition, excess intake of dietary Pi decreases renal α-klotho expression. Down-regulation or lack of α-klotho induces a premature aging-like phenotype, resulting from hyperphosphatemia, and leading to conditions such as ectopic calcification and osteoporosis. However, it remains unclear what effects dietary Pi has on α-klotho expression at different life stages, especially during growth periods. To investigate this, we used C57BL/6J mice in two life stages during growing period. Weaned (3 weeks old) and periadolescent (7 weeks old) were randomly divided into seven experimental groups and fed with 0.02, 0.3, 0.6, 0.9, 1.2, 1.5, or 1.8% Pi diets for 7 days. As a result, elevated plasma Pi and FGF23 levels and decreased renal α-klotho expression were observed in weaned mice fed with a high Pi diet. In addition, a high Pi diet clearly induced renal calcification in the weaned mice. However, in the periadolescent group, renal calcification was not observed, even in the 1.8% Pi diet group. The present study indicates that a high Pi diet in weaned mice has much greater adverse effects on renal α-klotho expression and pathogenesis of renal calcification compared with periadolescent mice.
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Affiliation(s)
- Shiori Fukuda-Tatano
- Department of Clinical Nutrition and Food Management, Institute of Biomedical Sciences, University of Tokushima Graduate School, 3-18-15 Kuramoto-cho, Tokushima, 770-8503, Japan
- Department of Health and Nutrition, Faculty of Nursing and Nutrition, The University of Shimane, 151 Nishihayashigi, Izumo, Shimane, 693-8550, Japan
| | - Hironori Yamamoto
- Department of Clinical Nutrition and Food Management, Institute of Biomedical Sciences, University of Tokushima Graduate School, 3-18-15 Kuramoto-cho, Tokushima, 770-8503, Japan
- Department of Health and Nutrition, Faculty of Human Life, Jin-ai University, Ohde-cho 3-1-1, Echizen, Fukui, 915-8586, Japan
- Department of Nephrology, Faculty of Medical Sciences, University of Fukui, Fukui, 910-1193, Japan
| | - Otoki Nakahashi
- Department of Clinical Nutrition and Food Management, Institute of Biomedical Sciences, University of Tokushima Graduate School, 3-18-15 Kuramoto-cho, Tokushima, 770-8503, Japan
- Division of Functional Food Chemistry, Institute for Health Science, Tokushima Bunri University, 180 Nishihamahoji, Yamashiro-cho, Tokushima, Tokushima, 770-8514, Japan
| | - Ryouhei Yoshikawa
- Department of Clinical Nutrition and Food Management, Institute of Biomedical Sciences, University of Tokushima Graduate School, 3-18-15 Kuramoto-cho, Tokushima, 770-8503, Japan
| | - Mayu Hayashi
- Department of Clinical Nutrition and Food Management, Institute of Biomedical Sciences, University of Tokushima Graduate School, 3-18-15 Kuramoto-cho, Tokushima, 770-8503, Japan
| | - Maki Kishimoto
- Department of Clinical Nutrition and Food Management, Institute of Biomedical Sciences, University of Tokushima Graduate School, 3-18-15 Kuramoto-cho, Tokushima, 770-8503, Japan
| | - Yukiko Imi
- Department of Clinical Nutrition and Dietetics, Konan Women's University, Kobe, 658-0001, Japan
| | - Hisami Yamanaka-Okumura
- Department of Clinical Nutrition and Food Management, Institute of Biomedical Sciences, University of Tokushima Graduate School, 3-18-15 Kuramoto-cho, Tokushima, 770-8503, Japan
| | - Kohta Ohnishi
- Department of Clinical Nutrition and Food Management, Institute of Biomedical Sciences, University of Tokushima Graduate School, 3-18-15 Kuramoto-cho, Tokushima, 770-8503, Japan
| | - Masashi Masuda
- Department of Clinical Nutrition and Food Management, Institute of Biomedical Sciences, University of Tokushima Graduate School, 3-18-15 Kuramoto-cho, Tokushima, 770-8503, Japan
| | - Yutaka Taketani
- Department of Clinical Nutrition and Food Management, Institute of Biomedical Sciences, University of Tokushima Graduate School, 3-18-15 Kuramoto-cho, Tokushima, 770-8503, Japan.
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Imi Y, Yabiki N, Abuduli M, Masuda M, Yamanaka-Okumura H, Taketani Y. High phosphate diet suppresses lipogenesis in white adipose tissue. J Clin Biochem Nutr 2018. [PMID: 30487667 DOI: 10.3164/jcbn.17.141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Excessive phosphate intake has been positively associated with renal and vascular dysfunction, conversely negatively associated with body fat accumulation. We investigated the effect of a high-phosphate diet on the expression of lipid metabolic genes in white adipose tissue and liver. Male 8-week-old Sprague-Dawley rats were fed a control diet containing 0.6% phosphate or a high-phosphate diet containing 1.5% phosphate for 4 weeks. In comparison to the control group, the HP group showed a significantly lower body fat mass and fasting plasma insulin level alongside decreased lipogenic and increased lipolytic gene expression in visceral fat. Additionally, the expression of genes involved in hepatic lipogenesis, hepatic glycogenesis, and triglyceride accumulation decreased in the high-phosphate group. Exogenous phosphate, parathyroid hormone, and fibroblast growth factor 23 did not directly affect the expression of lipolytic or lipogenic genes in 3T3-L1 adipocytes and HepG2 hepatocytes. Thus, the high-phosphate diet suppressed the activity of white adipose tissue by increasing lipolytic gene expression and decreasing lipogenic gene expression. These effects could have been caused by the lowered fasting plasma insulin level that occurred in response to the high-phosphate diet, but were not directly caused by the increases in plasma phosphate or phosphaturic hormones.
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Affiliation(s)
- Yukiko Imi
- Department of Clinical Nutrition and Food Management, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15 Kuramoto-cho, Tokushima 770-8503, Japan
| | - Norie Yabiki
- Department of Clinical Nutrition and Food Management, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15 Kuramoto-cho, Tokushima 770-8503, Japan
| | - Maerjianghan Abuduli
- Department of Clinical Nutrition and Food Management, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15 Kuramoto-cho, Tokushima 770-8503, Japan
| | - Masashi Masuda
- Department of Clinical Nutrition and Food Management, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15 Kuramoto-cho, Tokushima 770-8503, Japan
| | - Hisami Yamanaka-Okumura
- Department of Clinical Nutrition and Food Management, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15 Kuramoto-cho, Tokushima 770-8503, Japan
| | - Yutaka Taketani
- Department of Clinical Nutrition and Food Management, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15 Kuramoto-cho, Tokushima 770-8503, Japan
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Imi Y, Yabiki N, Abuduli M, Masuda M, Yamanaka-Okumura H, Taketani Y. High phosphate diet suppresses lipogenesis in white adipose tissue. J Clin Biochem Nutr 2018; 63:181-191. [PMID: 30487667 PMCID: PMC6252294 DOI: 10.3164/jcbn.17-141] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Accepted: 01/31/2018] [Indexed: 02/06/2023] Open
Abstract
Excessive phosphate intake has been positively associated with renal and vascular dysfunction, conversely negatively associated with body fat accumulation. We investigated the effect of a high-phosphate diet on the expression of lipid metabolic genes in white adipose tissue and liver. Male 8-week-old Sprague-Dawley rats were fed a control diet containing 0.6% phosphate or a high-phosphate diet containing 1.5% phosphate for 4 weeks. In comparison to the control group, the HP group showed a significantly lower body fat mass and fasting plasma insulin level alongside decreased lipogenic and increased lipolytic gene expression in visceral fat. Additionally, the expression of genes involved in hepatic lipogenesis, hepatic glycogenesis, and triglyceride accumulation decreased in the high-phosphate group. Exogenous phosphate, parathyroid hormone, and fibroblast growth factor 23 did not directly affect the expression of lipolytic or lipogenic genes in 3T3-L1 adipocytes and HepG2 hepatocytes. Thus, the high-phosphate diet suppressed the activity of white adipose tissue by increasing lipolytic gene expression and decreasing lipogenic gene expression. These effects could have been caused by the lowered fasting plasma insulin level that occurred in response to the high-phosphate diet, but were not directly caused by the increases in plasma phosphate or phosphaturic hormones.
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Affiliation(s)
- Yukiko Imi
- Department of Clinical Nutrition and Food Management, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15 Kuramoto-cho, Tokushima 770-8503, Japan
| | - Norie Yabiki
- Department of Clinical Nutrition and Food Management, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15 Kuramoto-cho, Tokushima 770-8503, Japan
| | - Maerjianghan Abuduli
- Department of Clinical Nutrition and Food Management, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15 Kuramoto-cho, Tokushima 770-8503, Japan
| | - Masashi Masuda
- Department of Clinical Nutrition and Food Management, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15 Kuramoto-cho, Tokushima 770-8503, Japan
| | - Hisami Yamanaka-Okumura
- Department of Clinical Nutrition and Food Management, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15 Kuramoto-cho, Tokushima 770-8503, Japan
| | - Yutaka Taketani
- Department of Clinical Nutrition and Food Management, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15 Kuramoto-cho, Tokushima 770-8503, Japan
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Sugihara K, Masuda M, Nakao M, Abuduli M, Imi Y, Oda N, Okahisa T, Yamamoto H, Takeda E, Taketani Y. Dietary phosphate exacerbates intestinal inflammation in experimental colitis. J Clin Biochem Nutr 2017; 61:91-99. [PMID: 28955125 PMCID: PMC5612814 DOI: 10.3164/jcbn.16-117] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 12/26/2016] [Indexed: 12/31/2022] Open
Abstract
The recent widespread consumption of Western diets and food additives worldwide is associated with excessive inorganic phosphate intake. However, researchers have known little about the impact of dietary phosphate intake on the development of inflammatory bowel disease to date. In this study, we investigated the effects of dietary phosphate on intestinal inflammation in experimental colitis. Sprague-Dawley rats were fed different phosphate diets (0.5%, 1.0% and 1.5% phosphate) with or without dextran sulfate sodium. For in vitro study, the effects of phosphate on proinflammatory cytokine induction and reactive oxygen species production in RAW264.7 macrophage were examined. Dietary phosphate exacerbated intestinal inflammation in experimental colitis in a dose-dependent manner, as assessed by the clinical disease activity score, colon length, and histology. Furthermore, the high phosphate diet increased myeloperoxidase activity and proinflammatory cytokine mRNA expression through the activation of nuclear factor κB in the inflamed colon. In addition, high phosphate loading in RAW264.7 cells directly enhanced reactive oxygen species production and proinflammatory cytokine gene expression. Our results demonstrated that the high phosphate diet exacerbated intestinal inflammation in experimental colitis. These findings have important therapeutic implications for inflammatory bowel disease patients.
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Affiliation(s)
- Kohei Sugihara
- Departments of Clinical Nutrition and Food Management, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima 770-8503, Japan
| | - Masashi Masuda
- Departments of Clinical Nutrition and Food Management, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima 770-8503, Japan
| | - Mari Nakao
- Departments of Clinical Nutrition and Food Management, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima 770-8503, Japan
| | - Maerjianghan Abuduli
- Departments of Clinical Nutrition and Food Management, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima 770-8503, Japan
| | - Yukiko Imi
- Departments of Clinical Nutrition and Food Management, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima 770-8503, Japan
| | - Naoko Oda
- Departments of Clinical Nutrition and Food Management, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima 770-8503, Japan
| | - Toshiya Okahisa
- Department of Gastroenterology and Oncology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima 770-8503, Japan
| | - Hironori Yamamoto
- Department of Health and Nutrition, Faculty of Human Life, Jin-ai University, Fukui 915-8586, Japan
| | - Eiji Takeda
- Departments of Clinical Nutrition and Food Management, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima 770-8503, Japan
| | - Yutaka Taketani
- Departments of Clinical Nutrition and Food Management, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima 770-8503, Japan
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Taketani Y, Imi Y, Abuduli M. [Bone and Nutrition. A novel function of phosphorus]. Clin Calcium 2015; 25:1015-1021. [PMID: 26119314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Phosphorus is an essential nutrient for bone formation by forming hydroxyapatite with calcium. Simultaneously, phosphorus is also a component of high energy bond of ATP, nucleic acids, and phospholipids. Recent studies have demonstrated that excess or lack of dietary phosphorus intake may cause vascular dysfunction, cardiac hypertrophy, and impaired glucose tolerance. Here, we introduce recent findings about the effects of high or low dietary phosphorus intake on several organs except for bone.
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Affiliation(s)
- Yutaka Taketani
- Department of Clinical Nutrition, Institute of Biomedical Sciences, Tokushima University Graduate School, Japan
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