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Zhao X, Sakamoto S, Wei J, Pae S, Saito S, Sazuka T, Imamura Y, Anzai N, Ichikawa T. Contribution of the L-Type Amino Acid Transporter Family in the Diagnosis and Treatment of Prostate Cancer. Int J Mol Sci 2023; 24:ijms24076178. [PMID: 37047148 PMCID: PMC10094571 DOI: 10.3390/ijms24076178] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 03/20/2023] [Accepted: 03/22/2023] [Indexed: 04/14/2023] Open
Abstract
The L-type amino acid transporter (LAT) family contains four members, LAT1~4, which are important amino acid transporters. They mainly transport specific amino acids through cell membranes, provide nutrients to cells, and are involved in a variety of metabolic pathways. They regulate the mTOR signaling pathway which has been found to be strongly linked to cancer in recent years. However, in the field of prostate cancer (PCa), the LAT family is still in the nascent stage of research, and the importance of LATs in the diagnosis and treatment of prostate cancer is still unknown. Therefore, this article aims to report the role of LATs in prostate cancer and their clinical significance and application. LATs promote the progression of prostate cancer by increasing amino acid uptake, activating the mammalian target of rapamycin (mTOR) pathway and downstream signals, mediating castration-resistance, promoting tumor angiogenesis, and enhancing chemotherapy resistance. The importance of LATs as diagnostic and therapeutic targets for prostate cancer was emphasized and the latest research results were introduced. In addition, we introduced selective LAT1 inhibitors, including JPH203 and OKY034, which showed excellent inhibitory effects on the proliferation of various tumor cells. This is the future direction of amino acid transporter targeting therapy drugs.
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Affiliation(s)
- Xue Zhao
- Department of Urology, Chiba University Graduate School of Medicine, Chiba 260-8670, Japan
| | - Shinichi Sakamoto
- Department of Urology, Chiba University Graduate School of Medicine, Chiba 260-8670, Japan
| | - Jiaxing Wei
- Department of Urology, Chiba University Graduate School of Medicine, Chiba 260-8670, Japan
| | - Sangjon Pae
- Department of Urology, Chiba University Graduate School of Medicine, Chiba 260-8670, Japan
- Department of Pharmacology, Chiba University Graduate School of Medicine, Chiba 260-8670, Japan
| | - Shinpei Saito
- Department of Urology, Chiba University Graduate School of Medicine, Chiba 260-8670, Japan
- Department of Pharmacology, Chiba University Graduate School of Medicine, Chiba 260-8670, Japan
| | - Tomokazu Sazuka
- Department of Urology, Chiba University Graduate School of Medicine, Chiba 260-8670, Japan
| | - Yusuke Imamura
- Department of Urology, Chiba University Graduate School of Medicine, Chiba 260-8670, Japan
| | - Naohiko Anzai
- Department of Pharmacology, Chiba University Graduate School of Medicine, Chiba 260-8670, Japan
| | - Tomohiko Ichikawa
- Department of Urology, Chiba University Graduate School of Medicine, Chiba 260-8670, Japan
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2
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Zha D, Wu X. Nutrient sensing, signaling transduction, and autophagy in podocyte injury: implications for kidney disease. J Nephrol 2023; 36:17-29. [PMID: 35704261 DOI: 10.1007/s40620-022-01365-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 03/05/2022] [Indexed: 02/07/2023]
Abstract
Podocytes are terminally differentiated epithelial cells of the renal glomerular tuft and these highly specialized cells are essential for the integrity of the slit diaphragm. The biological function of podocytes is primarily based on a complex ramified structure that requires sufficient nutrients and a large supply of energy in support of their unique structure and function in the glomeruli. Of note, the dysregulation of nutrient signaling and energy metabolic pathways in podocytes has been associated with a range of kidney diseases i.e., diabetic nephropathy. Therefore, nutrient-related and energy metabolic signaling pathways are critical to maintaining podocyte homeostasis and the pathogenesis of podocyte injury. Recently, a growing body of evidence has indicated that nutrient starvation induces autophagy, which suggests crosstalk between nutritional signaling with the modulation of autophagy for podocytes to adapt to nutrient deprivation. In this review, the current knowledge and advancement in the understanding of nutrient sensing, signaling, and autophagy in the podocyte biology, injury, and pathogenesis of kidney diseases is summarized. Based on the existing findings, the implications and perspective to target these signaling pathways and autophagy in podocytes during the development of novel preventive and therapeutic strategies in patients with podocyte injury-associated kidney diseases are discussed.
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Affiliation(s)
- Dongqing Zha
- Division of Nephrology, Zhongnan Hospital of Wuhan University, 169 Donghu Road, Wuhan, 430070, Hubei, China
| | - Xiaoyan Wu
- Division of Nephrology, Zhongnan Hospital of Wuhan University, 169 Donghu Road, Wuhan, 430070, Hubei, China.
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Hada I, Shimizu A, Takematsu H, Nishibori Y, Kimura T, Fukutomi T, Kudo A, Ito-Nitta N, Kiuchi Z, Patrakka J, Mikami N, Leclerc S, Akimoto Y, Hirayama Y, Mori S, Takano T, Yan K. A Novel Mouse Model of Idiopathic Nephrotic Syndrome Induced by Immunization with the Podocyte Protein Crb2. J Am Soc Nephrol 2022; 33:2008-2025. [PMID: 35985815 PMCID: PMC9678040 DOI: 10.1681/asn.2022010070] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Accepted: 07/25/2022] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND The cause of podocyte injury in idiopathic nephrotic syndrome (INS) remains unknown. Although recent evidence points to the role of B cells and autoimmunity, the lack of animal models mediated by autoimmunity limits further research. We aimed to establish a mouse model mimicking human INS by immunizing mice with Crb2, a transmembrane protein expressed at the podocyte foot process. METHODS C3H/HeN mice were immunized with the recombinant extracellular domain of mouse Crb2. Serum anti-Crb2 antibody, urine protein-to-creatinine ratio, and kidney histology were studied. For signaling studies, a Crb2-expressing mouse podocyte line was incubated with anti-Crb2 antibody. RESULTS Serum anti-Crb2 autoantibodies and significant proteinuria were detected 4 weeks after the first immunization. The proteinuria reached nephrotic range at 9-13 weeks and persisted up to 29 weeks. Initial kidney histology resembled minimal change disease in humans, and immunofluorescence staining showed delicate punctate IgG staining in the glomerulus, which colocalized with Crb2 at the podocyte foot process. A subset of mice developed features resembling FSGS after 18 weeks. In glomeruli of immunized mice and in Crb2-expressing podocytes incubated with anti-Crb2 antibody, phosphorylation of ezrin, which connects Crb2 to the cytoskeleton, increased, accompanied by altered Crb2 localization and actin distribution. CONCLUSION The results highlight the causative role of anti-Crb2 autoantibody in podocyte injury in mice. Crb2 immunization could be a useful model to study the immunologic pathogenesis of human INS, and may support the role of autoimmunity against podocyte proteins in INS.
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Affiliation(s)
- Ichiro Hada
- Department of Pediatrics, Kyorin University School of Medicine, Tokyo, Japan
| | - Akira Shimizu
- Department of Analytic Human Pathology, Nippon Medical School, Tokyo, Japan
| | - Hiromu Takematsu
- Department of Molecular Cell Biology, Faculty of Medical Technology, Graduate School of Health Sciences, Fujita Health University, Toyoake, Japan
| | - Yukino Nishibori
- Department of Pediatrics, Kyorin University School of Medicine, Tokyo, Japan
| | - Toru Kimura
- Department of Pharmacology and Toxicology, Kyorin University School of Medicine, Tokyo, Japan
| | - Toshiyuki Fukutomi
- Department of Pharmacology and Toxicology, Kyorin University School of Medicine, Tokyo, Japan
| | - Akihiko Kudo
- Department of Microscopic Anatomy, Kyorin University School of Medicine, Tokyo, Japan
| | - Noriko Ito-Nitta
- Department of Pediatrics, Kyorin University School of Medicine, Tokyo, Japan
| | - Zentaro Kiuchi
- Department of Pediatrics, Kyorin University School of Medicine, Tokyo, Japan
| | - Jaakko Patrakka
- KI/AZ Integrated Cardio Metabolic Center, Department of Laboratory Medicine, Karolinska Institutet at Karolinska University Hospital, Stockholm, Sweden
| | - Naoaki Mikami
- Department of Pediatrics, Kyorin University School of Medicine, Tokyo, Japan
| | - Simon Leclerc
- Department of Medicine, Division of Nephrology, Research Institute of the McGill University Health Centre, Montreal, Canada
| | - Yoshihiro Akimoto
- Department of Microscopic Anatomy, Kyorin University School of Medicine, Tokyo, Japan
| | - Yoshiaki Hirayama
- Vaccine & Reagent, R&D Department, Denka Co., Ltd, Gosen-City, Japan
| | - Satoka Mori
- Denka Innovation Center, Denka Co., Ltd, Machida, Japan
| | - Tomoko Takano
- Department of Medicine, Division of Nephrology, Research Institute of the McGill University Health Centre, Montreal, Canada
| | - Kunimasa Yan
- Department of Pediatrics, Kyorin University School of Medicine, Tokyo, Japan
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USP40 deubiquitinates HINT1 and stabilizes p53 in podocyte damage. Biochem Biophys Res Commun 2022; 614:198-206. [DOI: 10.1016/j.bbrc.2022.05.043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 05/12/2022] [Indexed: 11/21/2022]
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Wu X, Chen J, Liu C, Wang X, Zhou H, Mai K, He G. Slc38a9 Deficiency Induces Apoptosis and Metabolic Dysregulation and Leads to Premature Death in Zebrafish. Int J Mol Sci 2022; 23:ijms23084200. [PMID: 35457018 PMCID: PMC9025135 DOI: 10.3390/ijms23084200] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 04/04/2022] [Accepted: 04/05/2022] [Indexed: 02/05/2023] Open
Abstract
Eukaryotic cells control nutritional homeostasis and determine cell metabolic fate through a series of nutrient transporters and metabolic regulation pathways. Lysosomal localized amino acid transporter member 9 of the solute carrier family 38 (SLC38A9) regulates essential amino acids’ efflux from lysosomes in an arginine-regulated fashion. To better understand the physiological role of SLC38A9, we first described the spatiotemporal expression pattern of the slc38a9 gene in zebrafish. A quarter of slc38a9−/− mutant embryos developed pericardial edema and died prematurely, while the remaining mutants were viable and grew normally. By profiling the transcriptome of the abnormally developed embryos using RNA-seq, we identified increased apoptosis, dysregulated amino acid metabolism, and glycolysis/gluconeogenesis disorders that occurred in slc38a9−/− mutant fish. slc38a9 deficiency increased whole-body free amino acid and lactate levels but reduced glucose and pyruvate levels. The change of glycolysis-related metabolites in viable slc38a9−/− mutant fish was ameliorated. Moreover, loss of slc38a9 resulted in a significant reduction in hypoxia-inducible gene expression and hypoxia-inducible factor 1-alpha (Hif1α) protein levels. These results improved our understanding of the physiological functions of SLC38A9 and revealed its indispensable role in embryonic development, metabolic regulation, and stress adaption.
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Affiliation(s)
- Xiya Wu
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China; (X.W.); (J.C.); (X.W.); (H.Z.); (K.M.); (G.H.)
- Key Laboratory of Aquaculture Nutrition and Feeds, Ministry of Agriculture, Ocean University of China, Qingdao 266003, China
| | - Jianyang Chen
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China; (X.W.); (J.C.); (X.W.); (H.Z.); (K.M.); (G.H.)
- Key Laboratory of Aquaculture Nutrition and Feeds, Ministry of Agriculture, Ocean University of China, Qingdao 266003, China
| | - Chengdong Liu
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China; (X.W.); (J.C.); (X.W.); (H.Z.); (K.M.); (G.H.)
- Key Laboratory of Aquaculture Nutrition and Feeds, Ministry of Agriculture, Ocean University of China, Qingdao 266003, China
- Correspondence:
| | - Xuan Wang
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China; (X.W.); (J.C.); (X.W.); (H.Z.); (K.M.); (G.H.)
- Key Laboratory of Aquaculture Nutrition and Feeds, Ministry of Agriculture, Ocean University of China, Qingdao 266003, China
| | - Huihui Zhou
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China; (X.W.); (J.C.); (X.W.); (H.Z.); (K.M.); (G.H.)
- Key Laboratory of Aquaculture Nutrition and Feeds, Ministry of Agriculture, Ocean University of China, Qingdao 266003, China
| | - Kangsen Mai
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China; (X.W.); (J.C.); (X.W.); (H.Z.); (K.M.); (G.H.)
- Key Laboratory of Aquaculture Nutrition and Feeds, Ministry of Agriculture, Ocean University of China, Qingdao 266003, China
| | - Gen He
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China; (X.W.); (J.C.); (X.W.); (H.Z.); (K.M.); (G.H.)
- Key Laboratory of Aquaculture Nutrition and Feeds, Ministry of Agriculture, Ocean University of China, Qingdao 266003, China
- Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266003, China
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6
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A novel podocyte protein, R3h domain containing-like, inhibits TGF-β-induced p38 MAPK and regulates the structure of podocytes and glomerular basement membrane. J Mol Med (Berl) 2021; 99:859-876. [PMID: 33620517 DOI: 10.1007/s00109-021-02050-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 01/14/2021] [Accepted: 02/10/2021] [Indexed: 12/14/2022]
Abstract
Not only in kidney glomerular physiological function but also glomerular pathology especially in diabetic condition, glomerular podocytes play pivotal roles. Therefore, it is important to increase our knowledge about the genes and proteins expressed in podocytes. Recently, we have identified a novel podocyte-expressed gene, R3h domain containing-like (R3hdml) and analyzed its function in vivo as well as in vitro. Transforming growth factor-β (TGF-β) signaling regulated the expression of R3hdml. And R3hdml inhibited p38 mitogen-activated protein kinase phosphorylation, which was induced by TGF-β, leading to the amelioration of podocyte apoptosis. Furthermore, a lack of R3hdml in mice significantly worsened glomerular function in streptozotocin (STZ)-induced diabetes, while overexpression of R3hdml ameliorated albuminuria in STZ-induced diabetes. Our results surmise that the functional analyses of R3hdml may lead to the development of novel therapeutic strategies for diabetic nephropathy in the future. KEY MESSAGES: • A novel podocyte expressed protein R3h domain containing-like was identified. • R3HDML inhibits podocyte apoptosis by inhibiting TGF-β-mediated p38 MAPK signaling. • Overexpression of R3HDML ameliorates albuminuria in STZ-induced diabetes mice. • R3HDML may prove to be a novel therapeutic strategy for diabetic nephropathy.
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7
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Abstract
Human kidney tissue can now be generated via the directed differentiation of human pluripotent stem cells. This advance is anticipated to facilitate the modeling of human kidney diseases, provide platforms for nephrotoxicity screening, enable cellular therapy, and potentially generate tissue for renal replacement. All such applications will rely upon the accuracy and reliability of the model and the capacity for stem cell-derived kidney tissue to recapitulate both normal and diseased states. In this review, we discuss the models available, how well they recapitulate the human kidney, and how far we are from application of these cells for use in cellular therapies.
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Affiliation(s)
- Melissa H Little
- Murdoch Children's Research Institute, Parkville, Victoria 3052, Australia; .,Department of Paediatrics, University of Melbourne, Victoria 3010, Australia.,Department of Anatomy and Neuroscience, University of Melbourne, Victoria 3010, Australia
| | - Lorna J Hale
- Murdoch Children's Research Institute, Parkville, Victoria 3052, Australia;
| | - Sara E Howden
- Murdoch Children's Research Institute, Parkville, Victoria 3052, Australia; .,Department of Paediatrics, University of Melbourne, Victoria 3010, Australia
| | - Santhosh V Kumar
- Murdoch Children's Research Institute, Parkville, Victoria 3052, Australia; .,Department of Paediatrics, University of Melbourne, Victoria 3010, Australia
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8
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Akimoto Y, Yan K, Miura Y, Tsumoto H, Toda T, Fukutomi T, Sugahara D, Kudo A, Arai T, Chiba Y, Kaname S, Hart GW, Endo T, Kawakami H. O-GlcNAcylation and phosphorylation of β-actin Ser 199 in diabetic nephropathy. Am J Physiol Renal Physiol 2019; 317:F1359-F1374. [PMID: 31566433 PMCID: PMC6879942 DOI: 10.1152/ajprenal.00566.2018] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 08/28/2019] [Accepted: 09/08/2019] [Indexed: 12/18/2022] Open
Abstract
The function of actin is regulated by various posttranslational modifications. We have previously shown that in the kidneys of nonobese type 2 diabetes model Goto-Kakizaki rats, increased O-GlcNAcylation of β-actin protein is observed. It has also been reported that both O-GlcNAcylation and phosphorylation occur on Ser199 of β-actin. However, their roles are not known. To elucidate their roles in diabetic nephropathy, we examined the rat kidney for changes in O-GlcNAcylation of Ser199 (gS199)-actin and in the phosphorylation of Ser199 (pS199)-actin. Both gS199- and pS199-actin molecules had an apparent molecular weight of 40 kDa and were localized as nonfilamentous actin in both the cytoplasm and nucleus. Compared with the normal kidney, the immunostaining intensity of gS199-actin increased in podocytes of the glomeruli and in proximal tubules of the diabetic kidney, whereas that of pS199-actin did not change in podocytes but decreased in proximal tubules. We confirmed that the same results could be observed in the glomeruli of the human diabetic kidney. In podocytes of glomeruli cultured in the presence of the O-GlcNAcase inhibitor Thiamet G, increased O-GlcNAcylation was accompanied by a concomitant decrease in the amount of filamentous actin and in morphological changes. Our present results demonstrate that dysregulation of O-GlcNAcylation and phosphorylation of Ser199 occurred in diabetes, which may contribute partially to the causes of the morphological changes in the glomeruli and tubules. gS199- and pS199-actin will thus be useful for the pathological evaluation of diabetic nephropathy.
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Affiliation(s)
- Yoshihiro Akimoto
- Department of Anatomy, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Kunimasa Yan
- Department of Pediatrics, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Yuri Miura
- Research Team for Mechanism of Aging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan
| | - Hiroki Tsumoto
- Research Team for Mechanism of Aging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan
| | - Tosifusa Toda
- Research Team for Mechanism of Aging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan
| | - Toshiyuki Fukutomi
- Department of Pharmacology and Toxicology, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Daisuke Sugahara
- Department of Anatomy, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Akihiko Kudo
- Department of Anatomy, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Tomio Arai
- Department of Pathology, Tokyo Metropolitan Geriatric Hospital, Itabashi, Tokyo, Japan
| | - Yuko Chiba
- Department of Diabetes, Metabolism and Endocrinology, Tokyo Metropolitan Geriatric Hospital, Itabashi, Tokyo, Japan
| | - Shinya Kaname
- Department of Nephrology and Rheumatology, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Gerald W Hart
- Center for Complex Carbohydrates, University of Georgia, Athens, Georgia
| | - Tamao Endo
- Research Team for Mechanism of Aging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan
| | - Hayato Kawakami
- Department of Anatomy, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
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9
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Sakamoto K, Furuichi Y, Yamamoto M, Takahashi M, Akimoto Y, Ishikawa T, Shimizu T, Fujimoto M, Takada-Watanabe A, Hayashi A, Mita Y, Manabe Y, Fujii NL, Ishibashi R, Maezawa Y, Betsholtz C, Yokote K, Takemoto M. R3hdml regulates satellite cell proliferation and differentiation. EMBO Rep 2019; 20:e47957. [PMID: 31524320 DOI: 10.15252/embr.201947957] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 08/06/2019] [Accepted: 08/16/2019] [Indexed: 12/29/2022] Open
Abstract
In this study, we identified a previously uncharacterized skeletal satellite cell-secreted protein, R3h domain containing-like (R3hdml). Expression of R3hdml increases during skeletal muscle development and differentiation in mice. Body weight and skeletal muscle mass of R3hdml knockout (KO) mice are lower compared to control mice. Expression levels of cell cycle-related markers, phosphorylation of Akt, and expression of insulin-like growth factor within the skeletal muscle are reduced in R3hdml KO mice compared to control mice. Expression of R3hdml increases during muscle regeneration in response to cardiotoxin (CTX)-induced muscle injury. Recovery of handgrip strength after CTX injection was significantly impaired in R3hdml KO mice, which is rescued by R3hdml. Our results indicate that R3hdml is required for skeletal muscle development, regeneration, and, in particular, satellite cell proliferation and differentiation.
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Affiliation(s)
- Kenichi Sakamoto
- Department of Endocrinology, Hematology, and Gerontology, Chiba University Graduate School of Medicine, Chiba, Japan
| | - Yasuro Furuichi
- Department of Health Promotion Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, Hachioji, Tokyo, Japan
| | - Masashi Yamamoto
- Department of Endocrinology, Hematology, and Gerontology, Chiba University Graduate School of Medicine, Chiba, Japan
| | - Megumi Takahashi
- Department of Health Promotion Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, Hachioji, Tokyo, Japan
| | - Yoshihiro Akimoto
- Department of Anatomy, Kyorin University School of Medicine, Tokyo, Japan
| | - Takahiro Ishikawa
- Department of Endocrinology, Hematology, and Gerontology, Chiba University Graduate School of Medicine, Chiba, Japan.,Division of Diabetes, Metabolism and Endocrinology, Chiba University Hospital, Chiba, Japan
| | - Takahiko Shimizu
- Department of Endocrinology, Hematology, and Gerontology, Chiba University Graduate School of Medicine, Chiba, Japan.,Aging Stress Response Research Project Team, National Center for Geriatrics and Gerontology, Obu, Aichi, Japan
| | - Masanori Fujimoto
- Department of Endocrinology, Hematology, and Gerontology, Chiba University Graduate School of Medicine, Chiba, Japan
| | - Aki Takada-Watanabe
- Department of Endocrinology, Hematology, and Gerontology, Chiba University Graduate School of Medicine, Chiba, Japan
| | - Aiko Hayashi
- Department of Endocrinology, Hematology, and Gerontology, Chiba University Graduate School of Medicine, Chiba, Japan
| | - Yoshitaka Mita
- Department of Health Promotion Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, Hachioji, Tokyo, Japan
| | - Yasuko Manabe
- Department of Health Promotion Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, Hachioji, Tokyo, Japan
| | - Nobuharu L Fujii
- Department of Health Promotion Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, Hachioji, Tokyo, Japan
| | - Ryoichi Ishibashi
- Department of Endocrinology, Hematology, and Gerontology, Chiba University Graduate School of Medicine, Chiba, Japan
| | - Yoshiro Maezawa
- Department of Endocrinology, Hematology, and Gerontology, Chiba University Graduate School of Medicine, Chiba, Japan.,Division of Diabetes, Metabolism and Endocrinology, Chiba University Hospital, Chiba, Japan
| | - Christer Betsholtz
- Department of Immunology, Genetics and Pathology, Cancer and Vascular Biology, Uppsala Universitet, Uppsala, Sweden.,Integrated Cardio Metabolic Center (ICMC), Karolinska Institutet, Novum, Huddinge, Sweden
| | - Koutaro Yokote
- Department of Endocrinology, Hematology, and Gerontology, Chiba University Graduate School of Medicine, Chiba, Japan.,Division of Diabetes, Metabolism and Endocrinology, Chiba University Hospital, Chiba, Japan
| | - Minoru Takemoto
- Department of Endocrinology, Hematology, and Gerontology, Chiba University Graduate School of Medicine, Chiba, Japan.,Department of Diabetes, Metabolism and Endocrinology, School of Medicine, International University of Health and Welfare, Narita, Chiba, Japan
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10
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Zhang BK, Moran AM, Bailey CG, Rasko JEJ, Holst J, Wang Q. EGF-activated PI3K/Akt signalling coordinates leucine uptake by regulating LAT3 expression in prostate cancer. Cell Commun Signal 2019; 17:83. [PMID: 31345230 PMCID: PMC6659227 DOI: 10.1186/s12964-019-0400-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 07/16/2019] [Indexed: 02/06/2023] Open
Abstract
Background Growth factors, such as EGF, activate the PI3K/Akt/mTORC1 signalling pathway, which regulates a distinct program of protein synthesis leading to cell growth. This pathway relies on mTORC1 sensing sufficient levels of intracellular amino acids, such as leucine, which are required for mTORC1 activation. However, it is currently unknown whether there is a direct link between these external growth signals and intracellular amino acid levels. In primary prostate cancer cells, intracellular leucine levels are regulated by L-type amino acid transporter 3 (LAT3/SLC43A1), and we therefore investigated whether LAT3 is regulated by growth factor signalling. Methods To investigate how PI3K/Akt signalling regulates leucine transport, prostate cancer cells were treated with different PI3K/Akt inhibitors, or stable knock down of LAT3 by shRNA, followed by analysis of leucine uptake, western blotting, immunofluorescent staining and proximity ligation assay. Results Inhibition of PI3K/Akt signalling significantly reduced leucine transport in LNCaP and PC-3 human prostate cancer cell lines, while growth factor addition significantly increased leucine uptake. These effects appeared to be mediated by LAT3 transport, as LAT3 knockdown blocked leucine uptake, and was not rescued by growth factor activation or further inhibited by signalling pathway inhibition. We further demonstrated that EGF significantly increased LAT3 protein levels when Akt was phosphorylated, and that Akt and LAT3 co-localised on the plasma membrane in EGF-activated LNCaP cells. These effects were likely due to stabilisation of LAT3 protein levels on the plasma membrane, with EGF treatment preventing ubiquitin-mediated LAT3 degradation. Conclusion Growth factor-activated PI3K/Akt signalling pathway regulates leucine transport through LAT3 in prostate cancer cell lines. These data support a direct link between growth factor and amino acid uptake, providing a mechanism by which the cells rapidly coordinate amino acid uptake for cell growth. Electronic supplementary material The online version of this article (10.1186/s12964-019-0400-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Blake K Zhang
- Centenary Institute, University of Sydney, Camperdown, Australia.,Sydney Medical School, University of Sydney, Camperdown, Australia
| | - Anne M Moran
- Centenary Institute, University of Sydney, Camperdown, Australia.,Sydney Medical School, University of Sydney, Camperdown, Australia
| | - Charles G Bailey
- Sydney Medical School, University of Sydney, Camperdown, Australia.,Gene & Stem Cell Therapy Program Centenary Institute, University of Sydney, Camperdown, Australia
| | - John E J Rasko
- Sydney Medical School, University of Sydney, Camperdown, Australia.,Gene & Stem Cell Therapy Program Centenary Institute, University of Sydney, Camperdown, Australia.,Cell and Molecular Therapies, Royal Prince Alfred Hospital, Camperdown, Australia
| | - Jeff Holst
- Translational Cancer Metabolism Laboratory, Lowy Cancer Research Centre, School of Medical Sciences and Prince of Wales Clinical School, University of New South Wales, Sydney, Australia. .,Origins of Cancer Program Centenary Institute, University of Sydney, Camperdown, Australia.
| | - Qian Wang
- Sydney Medical School, University of Sydney, Camperdown, Australia. .,Translational Cancer Metabolism Laboratory, Lowy Cancer Research Centre, School of Medical Sciences and Prince of Wales Clinical School, University of New South Wales, Sydney, Australia.
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11
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Bonvini A, Coqueiro AY, Tirapegui J, Calder PC, Rogero MM. Immunomodulatory role of branched-chain amino acids. Nutr Rev 2018; 76:840-856. [DOI: 10.1093/nutrit/nuy037] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Affiliation(s)
- Andrea Bonvini
- Department of Food and Experimental Nutrition, Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Audrey Y Coqueiro
- Department of Food and Experimental Nutrition, Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Julio Tirapegui
- Department of Food and Experimental Nutrition, Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Philip C Calder
- Human Development and Health Academic Unit, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
- NIHR Southampton Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust and University of Southampton, Southampton, United Kingdom
| | - Marcelo M Rogero
- Department of Nutrition, Faculty of Public Health, University of São Paulo, São Paulo, Brazil
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12
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Association of crumbs homolog-2 with mTORC1 in developing podocyte. PLoS One 2018; 13:e0202400. [PMID: 30125302 PMCID: PMC6101391 DOI: 10.1371/journal.pone.0202400] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 08/02/2018] [Indexed: 02/06/2023] Open
Abstract
The evidence that gene mutations in the polarity determinant Crumbs homologs-2 (CRB2) cause congenital nephrotic syndrome suggests the functional importance of this gene product in podocyte development. Because another isoform, CRB3, was reported to repress the mechanistic/mammalian target of the rapamycin complex 1 (mTORC1) pathway, we examined the role of CRB2 function in developing podocytes in relation to mTORC1. In HEK-293 and MDCK cells constitutively expressing CRB2, we found that the protein localized to the apicolateral side of the cell plasma membrane and that this plasma membrane assembly required N-glycosylation. Confocal microscopy of the neonate mouse kidney revealed that both the tyrosine-phosphorylated form and non-phosphorylated form of CRB2 commence at the S-shaped body stage at the apicolateral side of podocyte precursor cells and move to foot processes in a capillary tuft pattern. The pattern of phosphorylated mTOR in developing podocytes was similar to that of CRB2 tyrosine phosphorylation. Additionally, the lack of a tyrosine phosphorylation site on CRB2 led to the reduced sensitivity of mTORC1 activation in response to energy starvation. CRB2 may play an important role in the mechanistic pathway of developing podocytes through tyrosine phosphorylation by associating with mTORC1 activation.
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13
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Ito Y, Katayama K, Nishibori Y, Akimoto Y, Kudo A, Kurayama R, Hada I, Takahashi S, Kimura T, Fukutomi T, Katada T, Suehiro J, Beltcheva O, Tryggvason K, Yan K. Wolf-Hirschhorn syndrome candidate 1-like 1 epigenetically regulates nephrin gene expression. Am J Physiol Renal Physiol 2017; 312:F1184-F1199. [PMID: 28228401 DOI: 10.1152/ajprenal.00305.2016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 02/09/2017] [Accepted: 02/21/2017] [Indexed: 01/13/2023] Open
Abstract
Altered expression of nephrin underlies the pathophysiology of proteinuria in both congenital and acquired nephrotic syndrome. However, the epigenetic mechanisms of nephrin gene regulation remain elusive. Here, we show that Wolf-Hirschhorn syndrome candidate 1-like 1 long form (WHSC1L1-L) is a novel epigenetic modifier of nephrin gene regulation. WHSC1L1-L was associated with histone H3K4 and H3K36 in human embryonic kidney cells. WHSC1L1-L gene was expressed in the podocytes, and functional protein product was detected in these cells. WHSC1L1-L was found to bind nephrin but not other podocyte-specific gene promoters, leading to its inhibition/suppression, abrogating the stimulatory effect of WT1 and NF-κB. Gene knockdown of WHSC1L1-L in primary cultured podocytes accelerated the transcription of nephrin but not CD2AP. An in vivo zebrafish study involving the injection of Whsc1l1 mRNA into embryos demonstrated an apparent reduction of nephrin mRNA but not podocin and CD2AP mRNA. Immunohistochemistry showed that both WHSC1L1-L and nephrin emerged at the S-shaped body stage in glomeruli. Immunofluorescence and confocal microscopy displayed WHSC1L1 to colocalize with trimethylated H3K4 in the glomerular podocytes. Chromatin immunoprecipitation assay revealed the reduction of the association of trimethylated H3K4 at the nephrin promoter regions. Finally, nephrin mRNA was upregulated in the glomerulus at the early proteinuric stage of mouse nephrosis, which was associated with the reduction of WHSC1L1. In conclusion, our results demonstrate that WHSC1L1-L acts as a histone methyltransferase in podocytes and regulates nephrin gene expression, which may in turn contribute to the integrity of the slit diaphragm of the glomerular filtration barrier.
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Affiliation(s)
- Yugo Ito
- Department of Pediatrics, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Kan Katayama
- Department of Medical Biochemistry and Biophysics, Division of Matrix Biology, Karolinska Institute, Stockholm, Sweden
| | - Yukino Nishibori
- Department of Pediatrics, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Yoshihiro Akimoto
- Department of Anatomy, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Akihiko Kudo
- Department of Anatomy, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Ryota Kurayama
- Department of Pediatrics, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Ichiro Hada
- Department of Pediatrics, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Shohei Takahashi
- Department of Pediatrics, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Toru Kimura
- Department of Pharmacology and Toxicology, Kyorin University School of Medicine, Mitaka, Tokyo, Japan; and
| | - Toshiyuki Fukutomi
- Department of Pharmacology and Toxicology, Kyorin University School of Medicine, Mitaka, Tokyo, Japan; and
| | - Tomohisa Katada
- Department of Pharmacology and Toxicology, Kyorin University School of Medicine, Mitaka, Tokyo, Japan; and
| | - Junichi Suehiro
- Department of Pharmacology and Toxicology, Kyorin University School of Medicine, Mitaka, Tokyo, Japan; and
| | - Olga Beltcheva
- Molecular Medicine Center and Department of Medical Chemistry and Biochemistry, Medical University of Sofia, Sofia, Bulgaria
| | - Karl Tryggvason
- Department of Medical Biochemistry and Biophysics, Division of Matrix Biology, Karolinska Institute, Stockholm, Sweden
| | - Kunimasa Yan
- Department of Pediatrics, Kyorin University School of Medicine, Mitaka, Tokyo, Japan;
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14
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Takagi H, Nishibori Y, Katayama K, Katada T, Takahashi S, Kiuchi Z, Takahashi SI, Kamei H, Kawakami H, Akimoto Y, Kudo A, Asanuma K, Takematsu H, Yan K. USP40 gene knockdown disrupts glomerular permeability in zebrafish. Am J Physiol Renal Physiol 2017; 312:F702-F715. [DOI: 10.1152/ajprenal.00197.2016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 01/23/2017] [Accepted: 01/24/2017] [Indexed: 11/22/2022] Open
Abstract
Unbiased transcriptome profiling and functional genomics approaches have identified ubiquitin-specific protease 40 (USP40) as a highly specific glomerular transcript. This gene product remains uncharacterized, and its biological function is completely unknown. Here, we showed that mouse and rat glomeruli exhibit specific expression of the USP40 protein, which migrated at 150 kDa and was exclusively localized in the podocyte cytoplasm of the adult kidney. Double-labeling immunofluorescence staining and confocal microscopy analysis of fetal and neonate kidney samples revealed that USP40 was also expressed in the vasculature, including in glomerular endothelial cells at the premature stage. USP40 in cultured glomerular endothelial cells and podocytes was specifically localized to the intermediate filament protein nestin. In glomerular endothelial cells, immunoprecipitation confirmed actual protein-protein binding of USP40 with nestin, and USP40-small-interfering RNA transfection revealed significant reduction of nestin. In a rat model of minimal-change nephrotic syndrome, USP40 expression was apparently reduced, which was also associated with the reduction of nestin. Zebrafish morphants lacking Usp40 exhibited disorganized glomeruli with the reduction of the cell junction in the endothelium and foot process effacement in the podocytes. Permeability studies in these zebrafish morphants demonstrated a disruption of the selective glomerular permeability filter. These data indicate that USP40/Usp40 is a novel protein that might play a crucial role in glomerulogenesis and the glomerular integrity after birth through the modulation of intermediate filament protein homeostasis.
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Affiliation(s)
- Hisashi Takagi
- Department of Pediatrics, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Yukino Nishibori
- Department of Pediatrics, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Kan Katayama
- Division of Matrix Biology, Department of Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden
| | - Tomohisa Katada
- Department of Pharmacology and Toxicology, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Shohei Takahashi
- Department of Pediatrics, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Zentaro Kiuchi
- Department of Pediatrics, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Shin-Ichiro Takahashi
- Laboratory of Cell Regulation, Department of Animal Sciences, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Hiroyasu Kamei
- Laboratory of Cell Regulation, Department of Animal Sciences, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Hayato Kawakami
- Department of Anatomy, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Yoshihiro Akimoto
- Department of Anatomy, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Akihiko Kudo
- Department of Anatomy, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Katsuhiko Asanuma
- Medical Innovation Center, TMK Project, Kyoto University Graduate School of Medicine, Kyoto, Japan; and
| | - Hiromu Takematsu
- Laboratory of Biochemistry, Human Health Science, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Kunimasa Yan
- Department of Pediatrics, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
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15
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Hayashi K, Anzai N. Novel therapeutic approaches targeting L-type amino acid transporters for cancer treatment. World J Gastrointest Oncol 2017; 9:21-29. [PMID: 28144396 PMCID: PMC5241523 DOI: 10.4251/wjgo.v9.i1.21] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 10/08/2016] [Accepted: 11/02/2016] [Indexed: 02/05/2023] Open
Abstract
L-type amino acid transporters (LATs) mainly assist the uptake of neutral amino acids into cells. Four LATs (LAT1, LAT2, LAT3 and LAT4) have so far been identified. LAT1 (SLC7A5) has been attracting much attention in the field of cancer research since it is commonly up-regulated in various cancers. Basic research has made it increasingly clear that LAT1 plays a predominant role in malignancy. The functional significance of LAT1 in cancer and the potential therapeutic application of the features of LAT1 to cancer management are described in this review.
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16
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Gutiérrez ML, Corchete L, Teodosio C, Sarasquete ME, del Mar Abad M, Iglesias M, Esteban C, Sayagues JM, Orfao A, Muñoz-Bellvis L. Identification and characterization of the gene expression profiles for protein coding and non-coding RNAs of pancreatic ductal adenocarcinomas. Oncotarget 2016; 6:19070-86. [PMID: 26053098 PMCID: PMC4662476 DOI: 10.18632/oncotarget.4233] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 05/13/2015] [Indexed: 12/13/2022] Open
Abstract
Significant advances have been achieved in recent years in the identification of the genetic and the molecular alterations of pancreatic ductal adenocarcinoma (PDAC). Despite this, at present the understanding of the precise mechanisms involved in the development and malignant transformation of PDAC remain relatively limited. Here, we evaluated for the first time, the molecular heterogeneity of PDAC tumors, through simultaneous assessment of the gene expression profile (GEP) for both coding and non-coding genes of tumor samples from 27 consecutive PDAC patients. Overall, we identified a common GEP for all PDAC tumors, characterized by an increased expression of genes involved in PDAC cell proliferation, local invasion and metastatic capacity, together with a significant alteration of the early steps of the cellular immune response. At the same time, we confirm and extend on previous observations about the genetic complexity of PDAC tumors as revealed by the demonstration of two clearly distinct and unique GEPs (e.g. epithelial-like vs. mesenchymal-like) reflecting the alteration of different signaling pathways involved in the oncogenesis and progression of these tumors. Our results also highlight the potential role of the immune system microenvironment in these tumors, with potential diagnostic and therapeutic implications.
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Affiliation(s)
- María Laura Gutiérrez
- Cytometry Service-NUCLEUS, Department of Medicine, Cancer Research Center (IBMCC-CSIC/USAL) and IBSAL (University of Salamanca), Salamanca, Spain
| | - Luis Corchete
- Cancer Research Center and Service of Hematology (University Hospital of Salamanca), Salamanca, Spain
| | - Cristina Teodosio
- Cytometry Service-NUCLEUS, Department of Medicine, Cancer Research Center (IBMCC-CSIC/USAL) and IBSAL (University of Salamanca), Salamanca, Spain
| | - María Eugenia Sarasquete
- Cancer Research Center and Service of Hematology (University Hospital of Salamanca), Salamanca, Spain
| | - María del Mar Abad
- Department of Pathology (University Hospital of Salamanca), Salamanca, Spain
| | - Manuel Iglesias
- Service of General and Gastrointestinal Surgery and IBSAL (University Hospital of Salamanca), Salamanca, Spain
| | - Carmen Esteban
- Service of General and Gastrointestinal Surgery and IBSAL (University Hospital of Salamanca), Salamanca, Spain
| | - José María Sayagues
- Cytometry Service-NUCLEUS, Department of Medicine, Cancer Research Center (IBMCC-CSIC/USAL) and IBSAL (University of Salamanca), Salamanca, Spain
| | - Alberto Orfao
- Cytometry Service-NUCLEUS, Department of Medicine, Cancer Research Center (IBMCC-CSIC/USAL) and IBSAL (University of Salamanca), Salamanca, Spain
| | - Luis Muñoz-Bellvis
- Service of General and Gastrointestinal Surgery and IBSAL (University Hospital of Salamanca), Salamanca, Spain
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17
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Zevenbergen C, Meima ME, Lima de Souza EC, Peeters RP, Kinne A, Krause G, Visser WE, Visser TJ. Transport of Iodothyronines by Human L-Type Amino Acid Transporters. Endocrinology 2015; 156:4345-55. [PMID: 26305885 DOI: 10.1210/en.2015-1140] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Thyroid hormone (TH) transporters facilitate cellular TH influx and efflux, which is paramount for normal physiology. The L-type amino acid transporters LAT1 and LAT2 are known to facilitate TH transport. However, the role of LAT3, LAT4, and LAT5 is still unclear. Therefore, the aim of this study was to further characterize TH transport by LAT1 and LAT2 and to explore possible TH transport by LAT3, LAT4, and LAT5. FLAG-LAT1-5 constructs were transiently expressed in COS1 cells. LAT1 and LAT2 were cotransfected with the CD98 heavy chain. Cellular transport was measured using 10 nM (125)I-labeled T4, T3, rT3, 3,3'-T2, and 10 μM [(125)I]3'-iodotyrosine (MIT) as substrates. Intracellular metabolism of these substrates was determined in cells cotransfected with either of the LATs with type 1 or type 3 deiodinase. LAT1 facilitated cellular uptake of all substrates and LAT2 showed a net uptake of T3, 3,3'-T2, and MIT. Expression of LAT3 or LAT4 did not affect transport of T4 and T3 but resulted in the decreased cellular accumulation of 3,3'-T2 and MIT. LAT5 did not facilitate the transport of any substrate. Cotransfection with LAT3 or LAT4 strongly diminished the cellular accumulation of 3,3'-T2 and MIT by LAT1 and LAT2. These data were confirmed by metabolism studies. LAT1 and LAT2 show distinct preferences for the uptake of the different iodocompounds, whereas LAT3 and LAT4 specifically facilitate the 3,3'-T2 and MIT efflux. Together our findings suggest that different sets of transporters with specific influx or efflux capacities may cooperate to regulate the cellular thyroid state.
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Affiliation(s)
- Chantal Zevenbergen
- Department of Internal Medicine and Rotterdam Thyroid Center (C.Z., M.E.M., E.C.L.d.S., R.P.P., W.E.V., T.J.V.), Erasmus University Medical Center, 3015 CN, Rotterdam, The Netherlands; and Department of Nuclear Magnetic Resonance-Supported Structural Biology (A.K., G.K.), Leibniz-Institut für Molekulare Pharmakologie, 13125 Berlin, Germany
| | - Marcel E Meima
- Department of Internal Medicine and Rotterdam Thyroid Center (C.Z., M.E.M., E.C.L.d.S., R.P.P., W.E.V., T.J.V.), Erasmus University Medical Center, 3015 CN, Rotterdam, The Netherlands; and Department of Nuclear Magnetic Resonance-Supported Structural Biology (A.K., G.K.), Leibniz-Institut für Molekulare Pharmakologie, 13125 Berlin, Germany
| | - Elaine C Lima de Souza
- Department of Internal Medicine and Rotterdam Thyroid Center (C.Z., M.E.M., E.C.L.d.S., R.P.P., W.E.V., T.J.V.), Erasmus University Medical Center, 3015 CN, Rotterdam, The Netherlands; and Department of Nuclear Magnetic Resonance-Supported Structural Biology (A.K., G.K.), Leibniz-Institut für Molekulare Pharmakologie, 13125 Berlin, Germany
| | - Robin P Peeters
- Department of Internal Medicine and Rotterdam Thyroid Center (C.Z., M.E.M., E.C.L.d.S., R.P.P., W.E.V., T.J.V.), Erasmus University Medical Center, 3015 CN, Rotterdam, The Netherlands; and Department of Nuclear Magnetic Resonance-Supported Structural Biology (A.K., G.K.), Leibniz-Institut für Molekulare Pharmakologie, 13125 Berlin, Germany
| | - Anita Kinne
- Department of Internal Medicine and Rotterdam Thyroid Center (C.Z., M.E.M., E.C.L.d.S., R.P.P., W.E.V., T.J.V.), Erasmus University Medical Center, 3015 CN, Rotterdam, The Netherlands; and Department of Nuclear Magnetic Resonance-Supported Structural Biology (A.K., G.K.), Leibniz-Institut für Molekulare Pharmakologie, 13125 Berlin, Germany
| | - Gerd Krause
- Department of Internal Medicine and Rotterdam Thyroid Center (C.Z., M.E.M., E.C.L.d.S., R.P.P., W.E.V., T.J.V.), Erasmus University Medical Center, 3015 CN, Rotterdam, The Netherlands; and Department of Nuclear Magnetic Resonance-Supported Structural Biology (A.K., G.K.), Leibniz-Institut für Molekulare Pharmakologie, 13125 Berlin, Germany
| | - W Edward Visser
- Department of Internal Medicine and Rotterdam Thyroid Center (C.Z., M.E.M., E.C.L.d.S., R.P.P., W.E.V., T.J.V.), Erasmus University Medical Center, 3015 CN, Rotterdam, The Netherlands; and Department of Nuclear Magnetic Resonance-Supported Structural Biology (A.K., G.K.), Leibniz-Institut für Molekulare Pharmakologie, 13125 Berlin, Germany
| | - Theo J Visser
- Department of Internal Medicine and Rotterdam Thyroid Center (C.Z., M.E.M., E.C.L.d.S., R.P.P., W.E.V., T.J.V.), Erasmus University Medical Center, 3015 CN, Rotterdam, The Netherlands; and Department of Nuclear Magnetic Resonance-Supported Structural Biology (A.K., G.K.), Leibniz-Institut für Molekulare Pharmakologie, 13125 Berlin, Germany
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18
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Chung J, Bauer DE, Ghamari A, Nizzi CP, Deck KM, Kingsley PD, Yien YY, Huston NC, Chen C, Schultz IJ, Dalton AJ, Wittig JG, Palis J, Orkin SH, Lodish HF, Eisenstein RS, Cantor AB, Paw BH. The mTORC1/4E-BP pathway coordinates hemoglobin production with L-leucine availability. Sci Signal 2015; 8:ra34. [PMID: 25872869 PMCID: PMC4402725 DOI: 10.1126/scisignal.aaa5903] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
In multicellular organisms, the mechanisms by which diverse cell types acquire distinct amino acids and how cellular function adapts to their availability are fundamental questions in biology. We found that increased neutral essential amino acid (NEAA) uptake was a critical component of erythropoiesis. As red blood cells matured, expression of the amino acid transporter gene Lat3 increased, which increased NEAA import. Inadequate NEAA uptake by pharmacologic inhibition or RNAi-mediated knockdown of LAT3 triggered a specific reduction in hemoglobin production in zebrafish embryos and murine erythroid cells through the mTORC1 (mammalian target of rapamycin complex 1)/4E-BP (eukaryotic translation initiation factor 4E-binding protein) pathway. CRISPR-mediated deletion of members of the 4E-BP family in murine erythroid cells rendered them resistant to mTORC1 and LAT3 inhibition and restored hemoglobin production. These results identify a developmental role for LAT3 in red blood cells and demonstrate that mTORC1 serves as a homeostatic sensor that couples hemoglobin production at the translational level to sufficient uptake of NEAAs, particularly L-leucine.
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MESH Headings
- Adaptor Proteins, Signal Transducing
- Amino Acid Transport Systems, Basic/genetics
- Amino Acid Transport Systems, Basic/metabolism
- Animals
- Animals, Genetically Modified
- CRISPR-Cas Systems
- Carrier Proteins/genetics
- Carrier Proteins/metabolism
- Cell Cycle Proteins
- Cell Line, Tumor
- Cells, Cultured
- Embryo, Mammalian/blood supply
- Embryo, Mammalian/embryology
- Embryo, Mammalian/metabolism
- Embryo, Nonmammalian/embryology
- Embryo, Nonmammalian/metabolism
- Erythroid Cells/metabolism
- Erythropoiesis/genetics
- Eukaryotic Initiation Factors/genetics
- Eukaryotic Initiation Factors/metabolism
- Gene Expression Regulation, Developmental
- HEK293 Cells
- Hemoglobins/genetics
- Hemoglobins/metabolism
- Humans
- Immunoblotting
- Leucine/metabolism
- Mechanistic Target of Rapamycin Complex 1
- Mice
- Microscopy, Confocal
- Multiprotein Complexes/genetics
- Multiprotein Complexes/metabolism
- Phosphoproteins/genetics
- Phosphoproteins/metabolism
- RNA Interference
- Reverse Transcriptase Polymerase Chain Reaction
- Signal Transduction/genetics
- TOR Serine-Threonine Kinases/genetics
- TOR Serine-Threonine Kinases/metabolism
- Zebrafish
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Affiliation(s)
- Jacky Chung
- Division of Hematology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Daniel E Bauer
- Division of Hematology-Oncology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA. Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Alireza Ghamari
- Division of Hematology-Oncology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA. Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Christopher P Nizzi
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Kathryn M Deck
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Paul D Kingsley
- Department of Pediatrics, Center for Pediatric Biomedical Research, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Yvette Y Yien
- Division of Hematology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Nicholas C Huston
- Division of Hematology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Caiyong Chen
- Division of Hematology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Iman J Schultz
- Division of Hematology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Arthur J Dalton
- Division of Hematology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Johannes G Wittig
- Division of Hematology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - James Palis
- Department of Pediatrics, Center for Pediatric Biomedical Research, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Stuart H Orkin
- Division of Hematology-Oncology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA. Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Harvey F Lodish
- Whitehead Institute for Biomedical Research, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Richard S Eisenstein
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Alan B Cantor
- Division of Hematology-Oncology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA. Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Barry H Paw
- Division of Hematology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA. Division of Hematology-Oncology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA. Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA.
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19
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Wang Q, Holst J. L-type amino acid transport and cancer: targeting the mTORC1 pathway to inhibit neoplasia. Am J Cancer Res 2015; 5:1281-1294. [PMID: 26101697 PMCID: PMC4473310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 03/12/2015] [Indexed: 06/04/2023] Open
Abstract
The L-type amino acid transporter (LAT) family are Na(+)-independent transporters, which deliver neutral amino acids into cells. The four LATs, LAT1 (SLC7A5), LAT2 (SLC7A8), LAT3 (SLC43A1) and LAT4 (SLC43A2), are responsible for the majority of cellular leucine uptake. They show increased expression in many cancers, and are critical for control of protein translation and cell growth through the mTORC1 pathway. The increased transporter expression observed in cancers is regulated by transcriptional pathways such as hormone receptors, c-myc and nutrient starvation responses. We review the expression and function of the LAT family in cancer, as well as the recent development of specific inhibitors targeting LAT1 or LAT3. These LAT family inhibitors may be useful adjuvant therapeutics in multiple cancers.
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Affiliation(s)
- Qian Wang
- Origins of Cancer Program, Centenary InstituteCamperdown, Australia
- Sydney Medical School, University of SydneyAustralia
| | - Jeff Holst
- Origins of Cancer Program, Centenary InstituteCamperdown, Australia
- Sydney Medical School, University of SydneyAustralia
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20
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Kroeger PT, Wingert RA. Using zebrafish to study podocyte genesis during kidney development and regeneration. Genesis 2014; 52:771-92. [PMID: 24920186 DOI: 10.1002/dvg.22798] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 06/08/2014] [Accepted: 06/09/2014] [Indexed: 12/21/2022]
Abstract
During development, vertebrates form a progression of up to three different kidneys that are comprised of functional units termed nephrons. Nephron composition is highly conserved across species, and an increasing appreciation of the similarities between zebrafish and mammalian nephron cell types has positioned the zebrafish as a relevant genetic system for nephrogenesis studies. A key component of the nephron blood filter is a specialized epithelial cell known as the podocyte. Podocyte research is of the utmost importance as a vast majority of renal diseases initiate with the dysfunction or loss of podocytes, resulting in a condition known as proteinuria that causes nephron degeneration and eventually leads to kidney failure. Understanding how podocytes develop during organogenesis may elucidate new ways to promote nephron health by stimulating podocyte replacement in kidney disease patients. In this review, we discuss how the zebrafish model can be used to study kidney development, and how zebrafish research has provided new insights into podocyte lineage specification and differentiation. Further, we discuss the recent discovery of podocyte regeneration in adult zebrafish, and explore how continued basic research using zebrafish can provide important knowledge about podocyte genesis in embryonic and adult environments. genesis 52:771-792, 2014. © 2014 Wiley Periodicals, Inc.
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Affiliation(s)
- Paul T Kroeger
- Department of Biological Sciences and Center for Zebrafish Research, University of Notre Dame, Notre Dame, Indiana, 46556
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21
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Rinschen MM, Wu X, König T, Pisitkun T, Hagmann H, Pahmeyer C, Lamkemeyer T, Kohli P, Schnell N, Schermer B, Dryer S, Brooks BR, Beltrao P, Krueger M, Brinkkoetter PT, Benzing T. Phosphoproteomic analysis reveals regulatory mechanisms at the kidney filtration barrier. J Am Soc Nephrol 2014; 25:1509-22. [PMID: 24511133 DOI: 10.1681/asn.2013070760] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Diseases of the kidney filtration barrier are a leading cause of ESRD. Most disorders affect the podocytes, polarized cells with a limited capacity for self-renewal that require tightly controlled signaling to maintain their integrity, viability, and function. Here, we provide an atlas of in vivo phosphorylated, glomerulus-expressed proteins, including podocyte-specific gene products, identified in an unbiased tandem mass spectrometry-based approach. We discovered 2449 phosphorylated proteins corresponding to 4079 identified high-confidence phosphorylated residues and performed a systematic bioinformatics analysis of this dataset. We discovered 146 phosphorylation sites on proteins abundantly expressed in podocytes. The prohibitin homology domain of the slit diaphragm protein podocin contained one such site, threonine 234 (T234), located within a phosphorylation motif that is mutated in human genetic forms of proteinuria. The T234 site resides at the interface of podocin dimers. Free energy calculation through molecular dynamic simulations revealed a role for T234 in regulating podocin dimerization. We show that phosphorylation critically regulates formation of high molecular weight complexes and that this may represent a general principle for the assembly of proteins containing prohibitin homology domains.
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Affiliation(s)
- Markus M Rinschen
- Department of Internal Medicine II, Center for Molecular Medicine, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, Systems Biology of Ageing Cologne
| | - Xiongwu Wu
- Laboratory of Computational Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland
| | - Tim König
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases,Institute for Genetics, University of Cologne, Cologne, Germany
| | - Trairak Pisitkun
- Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Henning Hagmann
- Department of Internal Medicine II, Center for Molecular Medicine
| | | | - Tobias Lamkemeyer
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases
| | - Priyanka Kohli
- Department of Internal Medicine II, Center for Molecular Medicine, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases
| | - Nicole Schnell
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases
| | - Bernhard Schermer
- Department of Internal Medicine II, Center for Molecular Medicine, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, Systems Biology of Ageing Cologne
| | - Stuart Dryer
- Department of Biology and Biochemistry, University of Houston, Houston, Texas; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases
| | - Bernard R Brooks
- Laboratory of Computational Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland
| | - Pedro Beltrao
- European Molecular Biology Laboratory-European Bioinformatics Institute, Hinxton, Cambridge, United Kingdom; and
| | - Marcus Krueger
- Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | | | - Thomas Benzing
- Department of Internal Medicine II, Center for Molecular Medicine, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, Systems Biology of Ageing Cologne,
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Miceli R, Kroeger P, Wingert R. Molecular Mechanisms of Podocyte Development Revealed by Zebrafish Kidney Research. ACTA ACUST UNITED AC 2014; 3. [PMID: 25485314 PMCID: PMC4254692 DOI: 10.4172/2168-9296.1000138] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Elucidating the gene regulatory networks that control kidney development can provide information about the origins of renal birth defects and kidney disease, as well as insights relevant to the design of clinical interventions for these conditions. The kidney is composed of functional units termed nephrons. Renal malfunction often arises from damage to cells known as podocytes, which are highly specialized epithelial cells that comprise the blood filter, or glomerulus, located on each nephron. Podocytes interact with the vasculature to create an elaborate sieve that collects circulatory fluid, and this filtrate enters the nephron where it is modified to produce urine and balance water homeostasis. Podocytes are an essential cellular component of the glomerular filtration barrier, helping to protect nephrons from the entry of large proteins and circulatory cells. Podocyte loss has catastrophic consequences for renal function and overall health, as podocyte destruction leads to nephron damage and pathological conditions like chronic kidney disease. Despite their importance, there is still a rather limited understanding about the molecular pathways that control podocyte formation. In recent years, however, studies of podocyte development using the zebrafish embryonic kidney, or pronephros, have been an expanding area of nephrology research. Zebrafish form an anatomically simple pronephros comprised of two nephrons that share a single blood filter, and podocyte progenitors can be easily visualized throughout the process of glomerular development. The zebrafish is an especially useful system for studying the mechanisms that are essential for formation of nephron cell types like podocytes due to the high genetic conservation between vertebrate species, including humans. In this review, we discuss how research using the zebrafish has provided new insights into the molecular regulation of the podocyte lineage during kidney ontogeny, complementing contemporary research in other animal models.
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Affiliation(s)
- R Miceli
- Department of Biological Sciences and Center for Zebrafish Research, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Pt Kroeger
- Department of Biological Sciences, University of Notre, Dame, 100 Galvin Life Sciences, Notre Dame, USA
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Increased expression of system large amino acid transporter (LAT)-1 mRNA is associated with invasive potential and unfavorable prognosis of human clear cell renal cell carcinoma. BMC Cancer 2013; 13:509. [PMID: 24168110 PMCID: PMC3832879 DOI: 10.1186/1471-2407-13-509] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Accepted: 10/28/2013] [Indexed: 12/22/2022] Open
Abstract
Background The system L amino acid transporter (LAT) has an important role in the transport of various amino acids, and there have been reports about the relation of this system to cancer. Although LATs are highly expressed in the kidneys, little is known about their influence on human renal cancer. Methods To clarify the role of LATs in human clear cell renal cell carcinoma (RCC), we investigated the expression of mRNAs for LAT1, LAT2, LAT3, LAT4, and 4F2hc in clear cell RCC tissues. The mRNAs of these five genes were analyzed by the real-time reverse transcription polymerase chain reaction in matched sets of tumor and non-tumor tissues obtained at operation from 82 Japanese patients with clear cell RCC. We also measured phosphorylated S6 ribosomal protein (Ser-235/236) proteins levels in 18 paired tumor and non-tumor tissues of the patients by Western blotting. Results Expression of LAT1 mRNA was significantly increased in tumor tissue compared with non-tumor tissue, while expression of LAT2 and LAT3 mRNAs was reduced. There was no difference in the expression of LAT4 and 4F2hc mRNAs between tumor and non-tumor tissues. Increased expression of LAT1 mRNA was associated with less differentiated tumors, local invasion, microscopic vascular invasion, and metastasis. Kaplan-Meier survival analysis showed that a higher serum LAT1 mRNA level was associated with a shorter overall survival time. Phosphorylated S6 ribosomal protein levels were associated with metastatic potential. LAT1 mRNA levels positively correlated with phosphorylated S6 ribosomal protein proteins levels in primary tumors. Conclusions These findings suggest that LAT1 mRNA is related to the invasive and progressive potential of clear cell RCC.
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Imasawa T, Rossignol R. Podocyte energy metabolism and glomerular diseases. Int J Biochem Cell Biol 2013; 45:2109-18. [PMID: 23806869 DOI: 10.1016/j.biocel.2013.06.013] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Revised: 06/10/2013] [Accepted: 06/14/2013] [Indexed: 11/16/2022]
Abstract
Mitochondria are crucial organelles that produce and deliver adenosine triphosphate (ATP), by which all cellular processes are driven. Although the mechanisms that control mitochondrial biogenesis, function and dynamics are complex process and vary among different cell types, recent studies provided many new discoveries in this field. Podocyte injury is a crucial step in the development of a large number of glomerular diseases. Glomerular podocytes are unique cells with complex foot processes that cover the outer layer of the glomerular basement membrane, and are the principle cells composing filtration barriers of glomerular capillaries. Little is known on the modalities and the regulation of podocyte's energetics as well as the type of energy substrate primarily used for their activity, recent studies revealed that dysfunction of energy transduction in podocytes may underlie the podocyte injury associated with numerous glomerular diseases. We herein review and discuss the importance of a fine regulation of energy metabolism in podocytes for maintaining their cellular structure and related kidney function. In the future, understanding these mechanisms will open up new areas of treatment for glomerular diseases.
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Bodoy S, Fotiadis D, Stoeger C, Kanai Y, Palacín M. The small SLC43 family: facilitator system l amino acid transporters and the orphan EEG1. Mol Aspects Med 2012; 34:638-45. [PMID: 23268354 DOI: 10.1016/j.mam.2012.12.006] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Accepted: 12/04/2012] [Indexed: 11/26/2022]
Abstract
The SLC43 family is composed of only three genes coding for the plasma membrane facilitator system l amino acid transporters LAT3 (SLC43A1; TC 2.A.1.44.1) and LAT4 (SLC43A2; TC 2.A.1.44.2), and the orphan protein EEG1 (SLC43A3; TC 2.A.1.44.3). Besides the known mechanism of transport of LAT3 and LAT4, their physiological roles still remain quite obscure. Morphants suggested a role of LAT3 in renal podocyte development in zebrafish. Expression in liver and skeletal muscle, and up-regulation by starvation suggest a role of LAT3 in the flux of branched-chain amino acids (BCAAs) from liver and skeletal muscle to the bloodstream. Finally, LAT3 is up-regulated in androgen-dependent cancers, suggesting a role in mTORC1 signaling in this type of tumors. In addition, LAT4 might contribute to the transfer of BCAAs from mother to fetus. Unfortunately, the EEG1 mouse model (EEG1(Y221∗)) described here has not yet offered a clue to the physiological role of this orphan protein.
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Affiliation(s)
- Susanna Bodoy
- Institute for Research in Biomedicine (IRB Barcelona), Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Barcelona, and Centro de Investigación Biomedica en Red de Enfermedades Raras, E-08028 Barcelona, Spain
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Gerlach GF, Wingert RA. Kidney organogenesis in the zebrafish: insights into vertebrate nephrogenesis and regeneration. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2012; 2:559-85. [PMID: 24014448 DOI: 10.1002/wdev.92] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Vertebrates form a progressive series of up to three kidney organs during development-the pronephros, mesonephros, and metanephros. Each kidney derives from the intermediate mesoderm and is comprised of conserved excretory units called nephrons. The zebrafish is a powerful model for vertebrate developmental genetics, and recent studies have illustrated that zebrafish and mammals share numerous similarities in nephron composition and physiology. The zebrafish embryo forms an architecturally simple pronephros that has two nephrons, and these eventually become a scaffold onto which a mesonephros of several hundred nephrons is constructed during larval stages. In adult zebrafish, the mesonephros exhibits ongoing nephrogenesis, generating new nephrons from a local pool of renal progenitors during periods of growth or following kidney injury. The characteristics of the zebrafish pronephros and mesonephros make them genetically tractable kidney systems in which to study the functions of renal genes and address outstanding questions about the mechanisms of nephrogenesis. Here, we provide an overview of the formation and composition of these zebrafish kidney organs, and discuss how various zebrafish mutants, gene knockdowns, and transgenic models have created frameworks in which to further delineate nephrogenesis pathways.
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Affiliation(s)
- Gary F Gerlach
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
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27
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Yan K, Ito N, Nakajo A, Kurayama R, Fukuhara D, Nishibori Y, Kudo A, Akimoto Y, Takenaka H. The struggle for energy in podocytes leads to nephrotic syndrome. Cell Cycle 2012; 11:1504-11. [PMID: 22433955 DOI: 10.4161/cc.19825] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Podocytes are terminally differentiated post-mitotic cells similar to neurons, and their damage leads to nephrotic syndrome, which is characterized by massive proteinuria associated with generalized edema. A recent functional genetic approach has identified the pathological relevance of several mutated proteins in glomerular podocytes to the mechanism of proteinuria in hereditary nephrotic syndrome. In contrast, the pathophysiology of acquired primary nephrotic syndrome, including minimal change disease, is still largely unknown. We recently demonstrated the possible linkage of an energy-consuming process in glomerular podocytes to the mechanism of proteinuria. Puromycin aminonucleoside nephrosis, a rat model of minimal change disease, revealed the activation of the unfolded protein response (UPR) in glomerular podocytes to be a cause of proteinuria. The pretreatment of puromycin aminonucleoside rat podocytes and cultured podocytes with the mammalian target of rapamycin (mTOR) inhibitor everolimus further revealed that mTOR complex 1 consumed energy, which was followed by UPR activation. In this paper, we will review nutritional transporters to summarize the energy uptake process in podocytes and review the involvement of the UPR in the pathogenesis of glomerular diseases. We will also present additional data that reveal how mTOR complex 1 acts upstream of the UPR. Finally, we will discuss the potential significance of targeting the energy metabolism of podocytes to develop new therapeutic interventions for acquired nephrotic syndrome.
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Affiliation(s)
- Kunimasa Yan
- Department of Pediatrics, Kyorin University School of Medicine, Mitaka, Tokyo, Japan.
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mTORC1 activation triggers the unfolded protein response in podocytes and leads to nephrotic syndrome. J Transl Med 2011; 91:1584-95. [PMID: 21876538 DOI: 10.1038/labinvest.2011.135] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Although podocyte damage is known to be responsible for the development of minimal-change disease (MCD), the underlying mechanism remains to be elucidated. Previously, using a rat MCD model, we showed that endoplasmic reticulum (ER) stress in the podocytes was associated with the heavy proteinuric state and another group reported that a mammalian target of rapamycin complex 1 (mTORC1) inhibitor protected against proteinuria. In this study, which utilized a rat MCD model, a combination of immunohistochemistry, dual immunofluorescence and confocal microscopy, western blot analysis, and quantitative real-time RT-PCR revealed co-activation of the unfolded protein response (UPR), which was induced by ER stress, and mTORC1 in glomerular podocytes before the onset of proteinuria and downregulation of nephrin at the post-translational level at the onset of proteinuria. Podocyte culture experiments revealed that mTORC1 activation preceded the UPR that was associated with a marked decrease in the energy charge. The mTORC1 inhibitor everolimus completely inhibited proteinuria through a reduction in both mTORC1 and UPR activity and preserved nephrin expression in the glomerular podocytes. In conclusion, mTORC1 activation may perturb the regulatory system of energy metabolism primarily by promoting energy consumption and inducing the UPR, which underlie proteinuria in MCD.
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Role of amino acid transporter LAT2 in the activation of mTORC1 pathway and the pathogenesis of crescentic glomerulonephritis. J Transl Med 2011; 91:992-1006. [PMID: 21403644 DOI: 10.1038/labinvest.2011.43] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Molecular mechanisms and signaling pathways leading to cellular proliferation and lesion formation in the crescentic glomerulonephritis (CGN) remain elusive. In the present study we have explored a potential role of the mammalian target of rapamycin complex 1 (mTORC1) signaling pathway and amino acid transporter (LAT) in the pathogenesis of CGN. Immunohistochemistry and western blot analysis of glomeruli isolated from a rat model of CGN revealed that activation of mTORC1 preceded crescent formation in glomerular parietal epithelial cells (PECs) and podocytes. Daily treatment of rats with the mTOR inhibitor everolimus just after induction of CGN was not beneficial and instead led to increased cellular necrosis of PECs. However, daily treatment starting 7 days after the onset of CGN was beneficial and maintained intact glomeruli. Out of three forms of L-type neutral amino acid transporters (LAT1-LAT3) studied here, only LAT2 was found to be upregulated in the PECs and podocytes in advance of the crescent formation as well as in the crescent lesion itself. Cell culture study revealed that plasma membrane expression of LAT2 markedly stimulated mTORC1 signaling pathway, which was significantly abrogated by coexistence of LAT inhibitor. Finally, LAT inhibitor significantly abrogated development of crescent formation of CGN on day 7. Our data suggest that LAT2 may have a pivotal role in the pathogenesis of CGN by activating the mTORC1 pathway in the glomerular epithelial cells.
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Zebrafish: a model system for the study of vertebrate renal development, function, and pathophysiology. Curr Opin Nephrol Hypertens 2011; 20:416-24. [DOI: 10.1097/mnh.0b013e3283477797] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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