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Li J, Xia Y, Kong S, Yang K, Chen H, Zhang Y, Liu D, Chen L, Sun X. Single-cell RNA-seq reveals actinic keratosis-specific keratinocyte subgroups and their crosstalk with secretory-papillary fibroblasts. J Eur Acad Dermatol Venereol 2023; 37:2273-2283. [PMID: 37357444 DOI: 10.1111/jdv.19289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 06/09/2023] [Indexed: 06/27/2023]
Abstract
BACKGROUND AND AIM Actinic keratosis (AK) represents an intraepidermal malignant neoplasm with the proliferation of atypical keratinocytes. AK lesions are regarded as early in situ squamous cell carcinomas (SCCs) having the potential to progress into invasive SCC (iSCC) and metastasize, causing death. This study aimed to investigate the heterogeneity of keratinocytes and how this heterogeneity promoted AK development and progression. METHODS We employed single-cell RNA sequencing (scRNA-seq) to examine the heterogeneity of keratinocytes and dermal fibroblast clusters in AKs and adjacent normal skins. Cell clustering, pseudotime trajectory construction, gene ontology enrichment analysis, transcription factor network analysis, and cell-cell communication were used to investigate the heterogeneity of keratinocytes in AK. The cellular identity and function were verified by immunohistochemical and immunofluorescence staining. RESULTS Using scRNA-seq, we revealed 13 keratinocyte subgroups (clusters 0-12) in AK tissues and characterized 2 AK-specific clusters. Cluster 9 displayed high levels of IL1R2 and WFDC2, and cluster 11 showed high levels of FADS2 and FASN. The percentages of cells in these two clusters significantly increased in AK compared with normal tissues. The existence and spatial localization of AK-specific IL1R2+WFDC2+ cluster were verified by immunohistochemical and immunofluorescence staining. Functional studies indicated that the genes identified in the IL1R2+WFDC2+ cluster were crucial for epithelial cell proliferation, migration, and angiogenesis. Further immunofluorescent staining revealed the interactions between AK-specific keratinocytes and secretory-papillary fibroblasts mainly through ANGPTL4-ITGA5 signalling pathway rarely seen in normal tissues. CONCLUSION The findings of this study might help better understand AK pathogenesis.
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Affiliation(s)
- Jun Li
- Department of Dermatology, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology (HUST), Wuhan, China
| | - Ying Xia
- Department of Dermatology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology (HUST), Wuhan, China
| | - Shumin Kong
- Department of Dermatology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology (HUST), Wuhan, China
| | - Kun Yang
- Department of Dermatology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology (HUST), Wuhan, China
| | - Hui Chen
- Department of Dermatology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology (HUST), Wuhan, China
| | - Yong Zhang
- Department of Dermatology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology (HUST), Wuhan, China
| | - Dongxian Liu
- Department of Dermatology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology (HUST), Wuhan, China
| | - Lan Chen
- Department of Dermatology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology (HUST), Wuhan, China
| | - Xiaoyan Sun
- Department of Dermatology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology (HUST), Wuhan, China
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Armour SL, Stanley JE, Cantley J, Dean ED, Knudsen JG. Metabolic regulation of glucagon secretion. J Endocrinol 2023; 259:e230081. [PMID: 37523232 PMCID: PMC10681275 DOI: 10.1530/joe-23-0081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 07/31/2023] [Indexed: 08/01/2023]
Abstract
Since the discovery of glucagon 100 years ago, the hormone and the pancreatic islet alpha cells that produce it have remained enigmatic relative to insulin-producing beta cells. Canonically, alpha cells have been described in the context of glucagon's role in glucose metabolism in liver, with glucose as the primary nutrient signal regulating alpha cell function. However, current data reveal a more holistic model of metabolic signalling, involving glucagon-regulated metabolism of multiple nutrients by the liver and other tissues, including amino acids and lipids, providing reciprocal feedback to regulate glucagon secretion and even alpha cell mass. Here we describe how various nutrients are sensed, transported and metabolised in alpha cells, providing an integrative model for the metabolic regulation of glucagon secretion and action. Importantly, we discuss where these nutrient-sensing pathways intersect to regulate alpha cell function and highlight key areas for future research.
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Affiliation(s)
- Sarah L Armour
- Section for cell biology and physiology, Department of Biology, University of Copenhagen, DK
| | - Jade E. Stanley
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, USA
| | - James Cantley
- Division of Cellular and systems medicine, School of Medicine, University of Dundee, UK
| | - E. Danielle Dean
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, USA
- Division of Diabetes, Endocrinology, & Metabolism, Vanderbilt University Medical Center school of medicine, USA
| | - Jakob G Knudsen
- Section for cell biology and physiology, Department of Biology, University of Copenhagen, DK
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Abstract
The islets of Langerhans are highly organized structures that have species-specific, three-dimensional tissue architecture. Islet architecture is critical for proper hormone secretion in response to nutritional stimuli. Islet architecture is disrupted in all types of diabetes mellitus and in cadaveric islets for transplantation during isolation, culture, and perfusion, limiting patient outcomes. Moreover, recapitulating native islet architecture remains a key challenge for in vitro generation of islets from stem cells. In this review, we discuss work that has led to the current understanding of determinants of pancreatic islet architecture, and how this architecture is maintained or disrupted during tissue remodeling in response to normal and pathological metabolic changes. We further discuss both empirical and modeling data that highlight the importance of islet architecture for islet function.
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Affiliation(s)
- Melissa T. Adams
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI, USA
| | - Barak Blum
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI, USA
- CONTACT Barak Blum Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI53705, USA
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Insights into the Role of Glucagon Receptor Signaling in Metabolic Regulation from Pharmacological Inhibition and Tissue-Specific Knockout Models. Biomedicines 2022; 10:biomedicines10081907. [PMID: 36009454 PMCID: PMC9405517 DOI: 10.3390/biomedicines10081907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 08/01/2022] [Accepted: 08/03/2022] [Indexed: 11/16/2022] Open
Abstract
While glucagon has long been recognized as the primary counter hormone to insulin’s actions, it has recently gained recognition as a metabolic regulator with its effects extending beyond control of glycemia. Recently developed models of tissue-specific glucagon receptor knockouts have advanced our understanding of this hormone, providing novel insight into the role it plays within organs as well as its systemic effects. Studies where the pharmacological blockade of the glucagon receptor has been employed have proved similarly valuable in the study of organ-specific and systemic roles of glucagon signaling. Studies carried out employing these tools demonstrate that glucagon indeed plays a role in regulating glycemia, but also in amino acid and lipid metabolism, systemic endocrine, and paracrine function, and in the response to cardiovascular injury. Here, we briefly review recent progress in our understanding of glucagon’s role made through inhibition of glucagon receptor signaling utilizing glucagon receptor antagonists and tissue specific genetic knockout models.
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Adipocyte-Specific ACKR3 Regulates Lipid Levels in Adipose Tissue. Biomedicines 2021; 9:biomedicines9040394. [PMID: 33917642 PMCID: PMC8067615 DOI: 10.3390/biomedicines9040394] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 03/30/2021] [Accepted: 03/31/2021] [Indexed: 01/06/2023] Open
Abstract
Dysfunctional adipose tissue (AT) may contribute to the pathology of several metabolic diseases through altered lipid metabolism, insulin resistance, and inflammation. Atypical chemokine receptor 3 (ACKR3) expression was shown to increase in AT during obesity, and its ubiquitous elimination caused hyperlipidemia in mice. Although these findings point towards a role of ACKR3 in the regulation of lipid levels, the role of adipocyte-specific ACKR3 has not yet been studied exclusively in this context. In this study, we established adipocyte- and hepatocyte-specific knockouts of Ackr3 in ApoE-deficient mice in order to determine its impact on lipid levels under hyperlipidemic conditions. We show for the first time that adipocyte-specific deletion of Ackr3 results in reduced AT triglyceride and cholesterol content in ApoE-deficient mice, which coincides with increased peroxisome proliferator-activated receptor-γ (PPAR-γ) and increased Angptl4 expression. The role of adipocyte ACKR3 in lipid handling seems to be tissue-specific as hepatocyte ACKR3 deficiency did not demonstrate comparable effects. In summary, adipocyte-specific ACKR3 seems to regulate AT lipid levels in hyperlipidemic Apoe−/− mice, which may therefore be a significant determinant of AT health. Further studies are needed to explore the potential systemic or metabolic effects that adipocyte ACKR3 might have in associated disease models.
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Abstract
Glucagon and its partner insulin are dually linked in both their secretion from islet cells and their action in the liver. Glucagon signaling increases hepatic glucose output, and hyperglucagonemia is partly responsible for the hyperglycemia in diabetes, making glucagon an attractive target for therapeutic intervention. Interrupting glucagon signaling lowers blood glucose but also results in hyperglucagonemia and α-cell hyperplasia. Investigation of the mechanism for α-cell proliferation led to the description of a conserved liver-α-cell axis where glucagon is a critical regulator of amino acid homeostasis. In return, amino acids regulate α-cell function and proliferation. New evidence suggests that dysfunction of the axis in humans may result in the hyperglucagonemia observed in diabetes. This discussion outlines important but often overlooked roles for glucagon that extend beyond glycemia and supports a new role for α-cells as amino acid sensors.
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Affiliation(s)
- E Danielle Dean
- Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Vanderbilt University Medical Center, and Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN
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7
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Hartig SM, Cox AR. Paracrine signaling in islet function and survival. J Mol Med (Berl) 2020; 98:451-467. [PMID: 32067063 DOI: 10.1007/s00109-020-01887-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 02/05/2020] [Accepted: 02/11/2020] [Indexed: 02/06/2023]
Abstract
The pancreatic islet is a dense cellular network comprised of several cell types with endocrine function vital in the control of glucose homeostasis, metabolism, and feeding behavior. Within the islet, endocrine hormones also form an intricate paracrine network with supportive cells (endothelial, neuronal, immune) and secondary signaling molecules regulating cellular function and survival. Modulation of these signals has potential consequences for diabetes development, progression, and therapeutic intervention. Beta cell loss, reduced endogenous insulin secretion, and dysregulated glucagon secretion are hallmark features of both type 1 and 2 diabetes that not only impact systemic regulation of glucose, but also contribute to the function and survival of cells within the islet. Advancing research and technology have revealed new islet biology (cellular identity and transcriptomes) and identified previously unrecognized paracrine signals and mechanisms (somatostatin and ghrelin paracrine actions), while shifting prior views of intraislet communication. This review will summarize the paracrine signals regulating islet endocrine function and survival, the disruption and dysfunction that occur in diabetes, and potential therapeutic targets to preserve beta cell mass and function.
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Affiliation(s)
- Sean M Hartig
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Baylor College of Medicine, Houston, TX, 77030, USA
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Aaron R Cox
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Baylor College of Medicine, Houston, TX, 77030, USA.
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8
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Jiang HC, Chen XR, Sun HF, Nie YW. Tumor promoting effects of glucagon receptor: a promising biomarker of papillary thyroid carcinoma via regulating EMT and P38/ERK pathways. Hum Cell 2019; 33:175-184. [PMID: 31782107 DOI: 10.1007/s13577-019-00284-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 09/14/2019] [Indexed: 02/07/2023]
Abstract
Glucagon is a crucial hormone involved in the maintenance of glucose homeostasis. Large efforts to define the role of glucagon receptor (GCGR) have been continuously made in recent years, but it is still incomplete about its function and mechanism. We performed this study to verify its potential impacts on papillary thyroid carcinoma (PTC) progression. Correlation between GCGR expression and PTC was elaborated using The Cancer Genome Atlas (TCGA) database. The Kaplan-Meier method was used to analyze the connection between GCGR expression and prognosis of PTC patients. GCGR expression was measured by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot analysis; simultaneously, cell viability was elucidated using cell proliferation and colony formation assays following siRNAs strategy. Transwell analyses were conducted to measure the invasion and migration of PTC cells. Flow cytometry analysis was conducted to examine apoptotic ability. The cAMP ELISA kit was employed to measure the cAMP level in PTC cells. Our data determined that the expression level of GCGR was increased in PTC tissues and cells in contrast to normal tissues and Nthy-ori 3-1, respectively. Up-regulated GCGR expression was linked with the lower survival rate in patients with PTC. Functional analysis in vitro suggested that GCGR knockdown attenuated PTC cell proliferation, colony formation, invasion, and migration whilst intensified apoptosis. Down-regulated GCGR was able to increase cAMP level. Furthermore, reduction of GCGR could result in the inactivation of epithelial-mesenchymal transition (EMT) and P38/ERK pathways. In conclusion, the findings of this study disclosed that GCGR promoted PTC cell behaviors by mediating the EMT and P38/ERK pathways, serving as a potential diagnostic and prognostic biomarker as well as therapeutic target for PTC.
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Affiliation(s)
- Hong-Chun Jiang
- Eye 3 Division of Red Flag Hospital of Mudanjiang Medical University, Mudanjiang, 157000, Heilongjiang, People's Republic of China
| | - Xiang-Ru Chen
- Color Doppler Ultrasound Room, The Second Affiliated Hospital of Mudanjiang Medical University, Mudanjiang, 157000, Heilongjiang, People's Republic of China
| | - Hai-Feng Sun
- Department of Endocrinology, The Second Affiliated Hospital of Mudanjiang Medical University, Mudanjiang, 157000, Heilongjiang, People's Republic of China
| | - Yuan-Wen Nie
- Hepatobiliary Surgery, The Second Affiliated Hospital of Mudanjiang Medical University, Mudanjiang, 157000, Heilongjiang, People's Republic of China.
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9
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Lam CJ, Rankin MM, King KB, Wang MC, Shook BC, Kushner JA. Glucagon Receptor Antagonist-Stimulated α-Cell Proliferation Is Severely Restricted With Advanced Age. Diabetes 2019; 68:963-974. [PMID: 30833466 PMCID: PMC6477910 DOI: 10.2337/db18-1293] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 02/18/2019] [Indexed: 01/26/2023]
Abstract
Glucagon-containing α-cells potently regulate glucose homeostasis, but the developmental biology of α-cells in adults remains poorly understood. Although glucagon receptor antagonists (GRAs) have great potential as antidiabetic therapies, murine and human studies have raised concerns that GRAs might cause uncontrolled α-cell growth. Surprisingly, previous rodent GRA studies were only performed in young mice, implying that the potential impact of GRAs to drive α-cell expansion in adult patients is unclear. We assessed adaptive α-cell turnover and adaptive proliferation, administering a novel GRA (JNJ-46207382) to both young and aged mice. Basal α-cell proliferation rapidly declined soon after birth and continued to drop to very low levels in aged mice. GRA drove a 2.4-fold increase in α-cell proliferation in young mice. In contrast, GRA-induced α-cell proliferation was severely reduced in aged mice, although still present at 3.2-fold the very low basal rate of aged controls. To interrogate the lineage of GRA-induced α-cells, we sequentially administered thymidine analogs and quantified their incorporation into α-cells. Similar to previous studies of β-cells, α-cells only divided once in both basal and stimulated conditions. Lack of contribution from highly proliferative "transit-amplifying" cells supports a model whereby α-cells expand by self-renewal and not via specialized progenitors.
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Affiliation(s)
- Carol J Lam
- McNair Medical Institute, Pediatric Diabetes and Endocrinology, Baylor College of Medicine, Houston, TX
- Division of Endocrinology and Diabetes, Children's Hospital of Philadelphia, University of Pennsylvania School of Medicine, Philadelphia, PA
| | - Matthew M Rankin
- Division of Endocrinology and Diabetes, Children's Hospital of Philadelphia, University of Pennsylvania School of Medicine, Philadelphia, PA
- Janssen Research and Development, Johnson & Johnson, Springhouse, PA
| | - Kourtney B King
- Division of Endocrinology and Diabetes, Children's Hospital of Philadelphia, University of Pennsylvania School of Medicine, Philadelphia, PA
| | - Melinda C Wang
- McNair Medical Institute, Pediatric Diabetes and Endocrinology, Baylor College of Medicine, Houston, TX
| | - Brian C Shook
- Janssen Research and Development, Johnson & Johnson, Springhouse, PA
| | - Jake A Kushner
- McNair Medical Institute, Pediatric Diabetes and Endocrinology, Baylor College of Medicine, Houston, TX
- Division of Endocrinology and Diabetes, Children's Hospital of Philadelphia, University of Pennsylvania School of Medicine, Philadelphia, PA
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10
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Rivero-Gutierrez B, Haller A, Holland J, Yates E, Khrisna R, Habegger K, Dimarchi R, D'Alessio D, Perez-Tilve D. Deletion of the glucagon receptor gene before and after experimental diabetes reveals differential protection from hyperglycemia. Mol Metab 2018; 17:28-38. [PMID: 30170980 PMCID: PMC6197675 DOI: 10.1016/j.molmet.2018.07.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 07/26/2018] [Accepted: 07/31/2018] [Indexed: 12/16/2022] Open
Abstract
OBJECTIVE Mice with congenital loss of the glucagon receptor gene (Gcgr-/- mice) remain normoglycemic in insulinopenic conditions, suggesting that unopposed glucagon action is the driving force for hyperglycemia in Type-1 Diabetes Mellitus (T1DM). However, chronic loss of GCGR results in a neomorphic phenotype that includes hormonal signals with hypoglycemic activity. We combined temporally-controlled GCGR deletion with pharmacological treatments to dissect the direct contribution of GCGR signaling to glucose control in a common mouse model of T1DM. METHODS We induced experimental T1DM by injecting the beta-cell cytotoxin streptozotocin (STZ) in mice with congenital or temporally-controlled Gcgr loss-of-function using tamoxifen (TMX). RESULTS Disruption of Gcgr expression, using either an inducible approach in adult mice or animals with congenital knockout, abolished the response to a long-acting Gcgr agonist. Mice with either developmental Gcgr disruption or inducible deletion several weeks before STZ treatment maintained normoglycemia. However, mice with inducible knockout of the Gcgr one week after the onset of STZ diabetes had only partial correction of hyperglycemia, an effect that was reversed by GLP-1 receptor blockade. Mice with Gcgr deletion for either 2 or 6 weeks had similar patterns of gene expression, although the changes were generally larger with longer GCGR knockout. CONCLUSIONS These findings demonstrate that the effects of glucagon to mitigate diabetic hyperglycemia are not through acute signaling but require compensations that take weeks to develop.
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Affiliation(s)
- Belen Rivero-Gutierrez
- Department of Internal Medicine, University of Cincinnati, 2180 E. Galbraith Rd, Cincinnati, OH, USA
| | - April Haller
- Department of Internal Medicine, University of Cincinnati, 2180 E. Galbraith Rd, Cincinnati, OH, USA
| | - Jenna Holland
- Department of Internal Medicine, University of Cincinnati, 2180 E. Galbraith Rd, Cincinnati, OH, USA
| | - Emily Yates
- Department of Internal Medicine, University of Cincinnati, 2180 E. Galbraith Rd, Cincinnati, OH, USA
| | - Radha Khrisna
- Department of Medicine, Duke University School of Medicine, NC, USA
| | - Kirk Habegger
- Comprehensive Diabetes Center and Department of Medicine - Endocrinology, Diabetes & and Metabolism, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Richard Dimarchi
- Novo Nordisk Research Center Indianapolis, Indianapolis, IN, USA; Department of Chemistry, Indiana University, Bloomington, IN, USA
| | - David D'Alessio
- Department of Medicine, Duke University School of Medicine, NC, USA
| | - Diego Perez-Tilve
- Department of Internal Medicine, University of Cincinnati, 2180 E. Galbraith Rd, Cincinnati, OH, USA.
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Weigert C, Hoene M, Plomgaard P. Hepatokines-a novel group of exercise factors. Pflugers Arch 2018; 471:383-396. [PMID: 30338347 DOI: 10.1007/s00424-018-2216-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 09/28/2018] [Accepted: 10/03/2018] [Indexed: 01/24/2023]
Abstract
Regular physical activity not only improves the exercise capacity of the skeletal muscle performing the contractions, but it is beneficial for the whole body. An extensive search for "exercise factors" mediating these beneficial effects has been going on for decades. Particularly skeletal muscle tissue has been investigated as a source of circulating exercise factors, and several myokines have been identified. However, exercise also has an impact on other tissues. The liver is interposed between energy storing and energy utilising tissues and is highly active during exercise, maintaining energy homeostasis. Recently, a novel group of exercise factors-termed hepatokines-has emerged. These proteins (fibroblast growth factor 21, follistatin, angiopoietin-like protein 4, heat shock protein 72, insulin-like growth factor binding protein 1) are released from the liver and increased in the bloodstream during or in the recovery after an exercise bout. In this narrative review, we evaluate this new group of exercise factors focusing on the regulation and potential function in exercise metabolism and adaptations. These hepatokines may convey some of the beneficial whole-body effects of exercise that could ameliorate metabolic diseases, such as obesity or type 2 diabetes.
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Affiliation(s)
- Cora Weigert
- Division of Endocrinology, Diabetology, Angiology, Nephrology, Pathobiochemistry and Clinical Chemistry, Department of Internal Medicine IV, University of Tuebingen, Otfried-Mueller Str. 10, 72076, Tuebingen, Germany. .,Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich, University of Tuebingen, Tuebingen, Germany. .,German Center for Diabetes Research (DZD), Tuebingen, Germany.
| | - Miriam Hoene
- Division of Endocrinology, Diabetology, Angiology, Nephrology, Pathobiochemistry and Clinical Chemistry, Department of Internal Medicine IV, University of Tuebingen, Otfried-Mueller Str. 10, 72076, Tuebingen, Germany
| | - Peter Plomgaard
- The Centre of Inflammation and Metabolism, and the Centre for Physical Activity Research, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark. .,Department of Clinical Biochemistry, Rigshospitalet, Rigshospitalet, Blegdamsvej 9, DK-2100, Copenhagen, Denmark. .,Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark.
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12
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He PP, Jiang T, OuYang XP, Liang YQ, Zou JQ, Wang Y, Shen QQ, Liao L, Zheng XL. Lipoprotein lipase: Biosynthesis, regulatory factors, and its role in atherosclerosis and other diseases. Clin Chim Acta 2018; 480:126-137. [DOI: 10.1016/j.cca.2018.02.006] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 02/06/2018] [Accepted: 02/07/2018] [Indexed: 01/20/2023]
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13
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Hayashi Y, Seino Y. Regulation of amino acid metabolism and α-cell proliferation by glucagon. J Diabetes Investig 2018; 9:464-472. [PMID: 29314731 PMCID: PMC5934249 DOI: 10.1111/jdi.12797] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 12/21/2017] [Indexed: 12/25/2022] Open
Abstract
Both glucagon and glucagon-like peptide-1 (GLP-1) are produced from proglucagon through proteolytic cleavage. Blocking glucagon action increases the circulating levels of glucagon and GLP-1, reduces the blood glucose level, and induces the proliferation of islet α-cells. Glucagon blockade also suppresses hepatic amino acid catabolism and increases the serum amino acid level. In animal models defective in both glucagon and GLP-1, the blood glucose level is not reduced, indicating that GLP-1 is required for glucagon blockade to reduce the blood glucose level. In contrast, hyperplasia of α-cells and hyperaminoacidemia are observed in such animal models, indicating that GLP-1 is not required for the regulation of α-cell proliferation or amino acid metabolism. These findings suggest that the regulation of amino acid metabolism is a more important specific physiological role of glucagon than the regulation of glucose metabolism. Although the effects of glucagon deficiency on glucose metabolism are compensated by the suppression of insulin secretion, the effects on amino acid metabolism are not. Recently, data showing a feedback regulatory mechanism between the liver and islet α-cells, which is mediated by glucagon and amino acids, are accumulating. However, a number of questions on the mechanism of this regulation remain to be addressed. The profile of glucagon as a regulator of amino acid metabolism must be carefully considered for glucagon blockade to be applied therapeutically in the treatment of patients with diabetes.
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Affiliation(s)
- Yoshitaka Hayashi
- Division of Stress Adaptation and ProtectionResearch Institute of Environmental MedicineNagoyaJapan
| | - Yusuke Seino
- Department of Endocrinology and DiabetesNagoya University Graduate School of MedicineNagoya UniversityNagoyaJapan
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Hoffmann C, Weigert C. Skeletal Muscle as an Endocrine Organ: The Role of Myokines in Exercise Adaptations. Cold Spring Harb Perspect Med 2017; 7:cshperspect.a029793. [PMID: 28389517 DOI: 10.1101/cshperspect.a029793] [Citation(s) in RCA: 181] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Exercise stimulates the release of proteins with autocrine, paracrine, or endocrine functions produced in skeletal muscle, termed myokines. Based on the current state of knowledge, the major physiological function of myokines is to protect the functionality and to enhance the exercise capacity of skeletal muscle. Myokines control adaptive processes in skeletal muscle by acting as paracrine regulators of fuel oxidation, hypertrophy, angiogenesis, inflammatory processes, and regulation of the extracellular matrix. Endocrine functions attributed to myokines are involved in body weight regulation, low-grade inflammation, insulin sensitivity, suppression of tumor growth, and improvement of cognitive function. Muscle-derived regulatory RNAs and metabolites, as well as the design of modified myokines, are promising novel directions for treatment of chronic diseases.
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Affiliation(s)
- Christoph Hoffmann
- Division of Pathobiochemistry and Clinical Chemistry, Department of Internal Medicine IV, University Hospital Tübingen, 72076 Tübingen, Germany
| | - Cora Weigert
- Division of Pathobiochemistry and Clinical Chemistry, Department of Internal Medicine IV, University Hospital Tübingen, 72076 Tübingen, Germany.,Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Zentrum München at the University of Tübingen, 72076 Tübingen, Germany.,German Center for Diabetes Research (DZD), 85764 München-Neuherberg, Germany
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15
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Liu L, Zhuang X, Jiang M, Guan F, Fu Q, Lin J. ANGPTL4 mediates the protective role of PPARγ activators in the pathogenesis of preeclampsia. Cell Death Dis 2017; 8:e3054. [PMID: 28933788 PMCID: PMC5636970 DOI: 10.1038/cddis.2017.419] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2017] [Revised: 07/06/2017] [Accepted: 07/18/2017] [Indexed: 11/18/2022]
Abstract
Peroxisome proliferator-activated receptor γ (PPARγ) has been shown to be a therapeutic target for preeclampsia (PE). Angiopoietin-like protein 4 (ANGPTL4) is a multifunctional secretory protein involved in regulating lipid metabolism and angiogenesis in various tissues. However, the expression of PPARγ and ANGPTL4 and their interaction in PE remain elusive. Here we showed that PPARγ agonist rosiglitazone upregulated the expression and secretion of ANGPTL4 in a dose-dependent manner in HTR8/SVneo cells, human umbilical vein endothelial cells (HUVECs) and placental explants. More importantly, we confirmed that the PPARγ/retinoid X receptor α heterodimer specifically binds to the ANGPTL4 promoter region and enhances its transcriptional activity. In addition, the levels of ANGPTL4 and PPARγ activators in the serum and their expression in placental tissues were significantly reduced in preeclamptic patients compared with normal pregnant subjects. Furthermore, functional studies demonstrated that ANGPTL4 mediates the facilitative effects of the PPARγ agonist on the survival, proliferation, migration and invasion of HTR8/SVneo cells, placental explants outgrowth and angiogenesis in HUVECs. Taken together, our results suggest that ANGPTL4 is a potential target gene for PPARγ and mediates the protective role of PPARγ activators in the pathogenesis of PE.
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Affiliation(s)
- Lei Liu
- Department of Obstetrics and Gynecology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Gynecologic Oncology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Xu Zhuang
- Department of Obstetrics and Gynecology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Meng Jiang
- Department of Obstetrics and Gynecology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Fei Guan
- Department of Obstetrics and Gynecology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Qin Fu
- Department of Obstetrics and Gynecology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Jianhua Lin
- Department of Obstetrics and Gynecology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Gynecologic Oncology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
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16
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Ingerslev B, Hansen JS, Hoffmann C, Clemmesen JO, Secher NH, Scheler M, Hrabĕ de Angelis M, Häring HU, Pedersen BK, Weigert C, Plomgaard P. Angiopoietin-like protein 4 is an exercise-induced hepatokine in humans, regulated by glucagon and cAMP. Mol Metab 2017; 6:1286-1295. [PMID: 29031727 PMCID: PMC5641605 DOI: 10.1016/j.molmet.2017.06.018] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 05/30/2017] [Accepted: 06/01/2017] [Indexed: 12/03/2022] Open
Abstract
Objective Angiopoietin-like protein-4 (ANGPTL4) is a circulating protein that is highly expressed in liver and implicated in regulation of plasma triglyceride levels. Systemic ANGPTL4 increases during prolonged fasting and is suggested to be secreted from skeletal muscle following exercise. Methods We investigated the origin of exercise-induced ANGPTL4 in humans by measuring the arterial-to-venous difference over the leg and the hepato-splanchnic bed during an acute bout of exercise. Furthermore, the impact of the glucagon-to-insulin ratio on plasma ANGPTL4 was studied in healthy individuals. The regulation of ANGPTL4 was investigated in both hepatic and muscle cells. Results The hepato-splanchnic bed, but not the leg, contributed to exercise-induced plasma ANGPTL4. Further studies using hormone infusions revealed that the glucagon-to-insulin ratio is an important regulator of plasma ANGPTL4 as elevated glucagon in the absence of elevated insulin increased plasma ANGPTL4 in resting subjects, whereas infusion of somatostatin during exercise blunted the increase of both glucagon and ANGPTL4. Moreover, activation of the cAMP/PKA signaling cascade let to an increase in ANGPTL4 mRNA levels in hepatic cells, which was prevented by inhibition of PKA. In humans, muscle ANGPTL4 mRNA increased during fasting, with only a marginal further induction by exercise. In human muscle cells, no inhibitory effect of AMPK activation could be demonstrated on ANGPTL4 expression. Conclusions The data suggest that exercise-induced ANGPTL4 is secreted from the liver and driven by a glucagon-cAMP-PKA pathway in humans. These findings link the liver, insulin/glucagon, and lipid metabolism together, which could implicate a role of ANGPTL4 in metabolic diseases. Release of Angiopoietin-like Protein 4 from the hepato-splanchnic bed is induced by exercise. It is regulated by the glucagon-to-insulin ratio in vivo in humans. In vitro in hepatocytes Angiopoietin-like Protein 4 is stimulated by cAMP. Angiopoietin-like Protein 4 is not released from the exercising nor resting leg.
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Affiliation(s)
- Bodil Ingerslev
- The Centre of Inflammation and Metabolism, The Centre for Physical Activity Research, Rigshospitalet, Copenhagen University Hospital, Denmark
| | - Jakob S Hansen
- The Centre of Inflammation and Metabolism, The Centre for Physical Activity Research, Rigshospitalet, Copenhagen University Hospital, Denmark; Department of Clinical Biochemistry, Rigshospitalet, Copenhagen University Hospital, Denmark
| | - Christoph Hoffmann
- Division of Endocrinology, Diabetology, Angiology, Nephrology, Pathobiochemistry and Clinical Chemistry, Department of Internal Medicine IV, University of Tuebingen, Germany
| | - Jens O Clemmesen
- Department of Hepatology, Rigshospitalet, Copenhagen University Hospital, Denmark
| | - Niels H Secher
- Department of Anaesthesiology, The Copenhagen Muscle Research Centre, Rigshospitalet, Copenhagen University Hospital, Denmark
| | - Mika Scheler
- Institute of Experimental Genetics, Helmholtz Center Munich, German Research Center for Enviromental Health Neuherberg, Germany; German Center for Diabetes Research (DZD), Germany
| | - Martin Hrabĕ de Angelis
- Institute of Experimental Genetics, Helmholtz Center Munich, German Research Center for Enviromental Health Neuherberg, Germany; German Center for Diabetes Research (DZD), Germany; Center of Life and Food Sciences Weihenstephan, Technical University Munich, Freising-Weihenstephan, Germany
| | - Hans U Häring
- Division of Endocrinology, Diabetology, Angiology, Nephrology, Pathobiochemistry and Clinical Chemistry, Department of Internal Medicine IV, University of Tuebingen, Germany; German Center for Diabetes Research (DZD), Germany; Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the University of Tuebingen, Tuebingen, Germany
| | - Bente K Pedersen
- The Centre of Inflammation and Metabolism, The Centre for Physical Activity Research, Rigshospitalet, Copenhagen University Hospital, Denmark
| | - Cora Weigert
- Division of Endocrinology, Diabetology, Angiology, Nephrology, Pathobiochemistry and Clinical Chemistry, Department of Internal Medicine IV, University of Tuebingen, Germany; German Center for Diabetes Research (DZD), Germany; Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the University of Tuebingen, Tuebingen, Germany
| | - Peter Plomgaard
- The Centre of Inflammation and Metabolism, The Centre for Physical Activity Research, Rigshospitalet, Copenhagen University Hospital, Denmark; Department of Clinical Biochemistry, Rigshospitalet, Copenhagen University Hospital, Denmark.
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17
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Yang LY, Yu CG, Wang XH, Yuan SS, Zhang LJ, Lang JN, Zhao D, Feng YM. Angiopoietin-Like Protein 4 Is a High-Density Lipoprotein (HDL) Component for HDL Metabolism and Function in Nondiabetic Participants and Type-2 Diabetic Patients. J Am Heart Assoc 2017. [PMID: 28645936 PMCID: PMC5669195 DOI: 10.1161/jaha.117.005973] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Background ANGPTL4 (angiopoietin‐like protein 4) is a LPL (lipoprotein lipase) inhibitor and is present in high‐density lipoprotein (HDL). However, it is not defined whether ANGPTL4 in HDLs could affect HDL metabolism and function in type 2 diabetes mellitus (T2DM). Methods and Results ANGPTL4 levels in the circulation and HDLs were quantified in nondiabetic participants (n=201, 68.7% females) and T2DM patients (n=185, 66.5% females). HDLs were isolated from nondiabetic controls and T2DM patients to assess cholesterol efflux or subjected to endothelial lipase (EL)‐overexpressed HEK293 cells for EL hydrolysis in vitro. The association between ANGPTL4 in HDLs and HDL components and function was analyzed in nondiabetic participants or diabetic patients, respectively. Plasma or HDLs of ANGPTL4+/+ and ANGPTL4−/− mice was subjected for cholesterol efflux or EL hydrolysis, respectively. ANGPTL4 levels in the plasma and HDLs were 1.7‐ and 2.0‐fold higher in T2DM patients than nondiabetic controls, respectively (P<0.0001). Multivariable analysis demonstrated that per 1 doubling increase of ANGPTL4 levels in HDLs, the changes amounted to +0.27% cholesterol efflux (P=0.03), +0.06 μg/mL apolipoprotein A‐I (P=0.09) and −9.41 μg/L serum amyloid A (P=0.02) in nondiabetic controls. In T2DM patients, the corresponding estimates were −0.06% cholesterol efflux (P=0.10), −0.06 μg/mL apolipoprotein A‐I (P=0.38), and +3.64 μg/L serum amyloid A (P=0.72). HDLs isolated from ANGPTL4−/− mice showed accelerated hydrolysis by EL and reduced cholesterol efflux compared with ANGPTL4+/+ littermates. Conclusions Physically, ANGPTL4 in HDLs protected HDLs from hydrolysis. Resulting from increased circulating ANGPTL4 levels in T2DM, ANGPTL4 levels in HDLs were elevated but with compromised inhibitory effect on EL, leading to increased HDL hydrolysis and dysfunction.
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Affiliation(s)
- Long-Yan Yang
- Beijing Key Laboratory of Diabetes Prevention and Research, Department of Endocrinology, Lu He Hospital, Capital Medical University, Beijing, China
| | - Cai-Guo Yu
- Beijing Key Laboratory of Diabetes Prevention and Research, Department of Endocrinology, Lu He Hospital, Capital Medical University, Beijing, China
| | - Xu-Hong Wang
- Beijing Key Laboratory of Diabetes Prevention and Research, Department of Endocrinology, Lu He Hospital, Capital Medical University, Beijing, China
| | - Sha-Sha Yuan
- Beijing Key Laboratory of Diabetes Prevention and Research, Department of Endocrinology, Lu He Hospital, Capital Medical University, Beijing, China
| | - Li-Jie Zhang
- Beijing Key Laboratory of Diabetes Prevention and Research, Department of Endocrinology, Lu He Hospital, Capital Medical University, Beijing, China
| | - Jia-Nan Lang
- Beijing Key Laboratory of Diabetes Prevention and Research, Department of Endocrinology, Lu He Hospital, Capital Medical University, Beijing, China
| | - Dong Zhao
- Beijing Key Laboratory of Diabetes Prevention and Research, Department of Endocrinology, Lu He Hospital, Capital Medical University, Beijing, China
| | - Ying-Mei Feng
- Beijing Key Laboratory of Diabetes Prevention and Research, Department of Endocrinology, Lu He Hospital, Capital Medical University, Beijing, China
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18
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Kim J, Okamoto H, Huang Z, Anguiano G, Chen S, Liu Q, Cavino K, Xin Y, Na E, Hamid R, Lee J, Zambrowicz B, Unger R, Murphy AJ, Xu Y, Yancopoulos GD, Li WH, Gromada J. Amino Acid Transporter Slc38a5 Controls Glucagon Receptor Inhibition-Induced Pancreatic α Cell Hyperplasia in Mice. Cell Metab 2017; 25:1348-1361.e8. [PMID: 28591637 PMCID: PMC8206958 DOI: 10.1016/j.cmet.2017.05.006] [Citation(s) in RCA: 134] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 03/09/2017] [Accepted: 05/21/2017] [Indexed: 12/22/2022]
Abstract
Glucagon supports glucose homeostasis by stimulating hepatic gluconeogenesis, in part by promoting the uptake and conversion of amino acids into gluconeogenic precursors. Genetic disruption or pharmacologic inhibition of glucagon signaling results in elevated plasma amino acids and compensatory glucagon hypersecretion involving expansion of pancreatic α cell mass. Recent findings indicate that hyperaminoacidemia triggers pancreatic α cell proliferation via an mTOR-dependent pathway. We confirm and extend these findings by demonstrating that glucagon pathway blockade selectively increases expression of the sodium-coupled neutral amino acid transporter Slc38a5 in a subset of highly proliferative α cells and that Slc38a5 controls the pancreatic response to glucagon pathway blockade; most notably, mice deficient in Slc38a5 exhibit markedly decreased α cell hyperplasia to glucagon pathway blockade-induced hyperaminoacidemia. These results show that Slc38a5 is a key component of the feedback circuit between glucagon receptor signaling in the liver and amino-acid-dependent regulation of pancreatic α cell mass in mice.
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Affiliation(s)
- Jinrang Kim
- Regeneron Pharmaceuticals, Inc., Tarrytown, NY 10591, USA
| | - Haruka Okamoto
- Regeneron Pharmaceuticals, Inc., Tarrytown, NY 10591, USA
| | - ZhiJiang Huang
- Departments of Cell Biology and of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75235, USA
| | - Guillermo Anguiano
- Departments of Cell Biology and of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75235, USA
| | - Shiuhwei Chen
- Departments of Cell Biology and of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75235, USA
| | - Qing Liu
- Departments of Cell Biology and of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75235, USA
| | - Katie Cavino
- Regeneron Pharmaceuticals, Inc., Tarrytown, NY 10591, USA
| | - Yurong Xin
- Regeneron Pharmaceuticals, Inc., Tarrytown, NY 10591, USA
| | - Erqian Na
- Regeneron Pharmaceuticals, Inc., Tarrytown, NY 10591, USA
| | - Rachid Hamid
- Regeneron Pharmaceuticals, Inc., Tarrytown, NY 10591, USA
| | - Joseph Lee
- Regeneron Pharmaceuticals, Inc., Tarrytown, NY 10591, USA
| | | | - Roger Unger
- Touchstone Center for Diabetes Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75235, USA
| | | | - Yan Xu
- Departments of Cell Biology and of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75235, USA
| | | | - Wen-Hong Li
- Departments of Cell Biology and of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75235, USA.
| | - Jesper Gromada
- Regeneron Pharmaceuticals, Inc., Tarrytown, NY 10591, USA.
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Dean ED, Li M, Prasad N, Wisniewski SN, Von Deylen A, Spaeth J, Maddison L, Botros A, Sedgeman LR, Bozadjieva N, Ilkayeva O, Coldren A, Poffenberger G, Shostak A, Semich MC, Aamodt KI, Phillips N, Yan H, Bernal-Mizrachi E, Corbin JD, Vickers KC, Levy SE, Dai C, Newgard C, Gu W, Stein R, Chen W, Powers AC. Interrupted Glucagon Signaling Reveals Hepatic α Cell Axis and Role for L-Glutamine in α Cell Proliferation. Cell Metab 2017; 25:1362-1373.e5. [PMID: 28591638 PMCID: PMC5572896 DOI: 10.1016/j.cmet.2017.05.011] [Citation(s) in RCA: 147] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Revised: 03/15/2017] [Accepted: 05/23/2017] [Indexed: 02/06/2023]
Abstract
Decreasing glucagon action lowers the blood glucose and may be useful therapeutically for diabetes. However, interrupted glucagon signaling leads to α cell proliferation. To identify postulated hepatic-derived circulating factor(s) responsible for α cell proliferation, we used transcriptomics/proteomics/metabolomics in three models of interrupted glucagon signaling and found that proliferation of mouse, zebrafish, and human α cells was mTOR and FoxP transcription factor dependent. Changes in hepatic amino acid (AA) catabolism gene expression predicted the observed increase in circulating AAs. Mimicking these AA levels stimulated α cell proliferation in a newly developed in vitro assay with L-glutamine being a critical AA. α cell expression of the AA transporter Slc38a5 was markedly increased in mice with interrupted glucagon signaling and played a role in α cell proliferation. These results indicate a hepatic α islet cell axis where glucagon regulates serum AA availability and AAs, especially L-glutamine, regulate α cell proliferation and mass via mTOR-dependent nutrient sensing.
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Affiliation(s)
- E Danielle Dean
- Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Mingyu Li
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN 37232, USA; School of Pharmaceutical Sciences, Xiamen University, Xiamen 361005, China
| | - Nripesh Prasad
- HudsonAlpha Institute for Biotechnology, Huntsville, AL 35806, USA
| | - Scott N Wisniewski
- Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Alison Von Deylen
- Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Jason Spaeth
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Lisette Maddison
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Anthony Botros
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Leslie R Sedgeman
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Nadejda Bozadjieva
- Division of Metabolism, Endocrinology, and Diabetes, University of Michigan Health System, Ann Arbor, MI 48103, USA
| | - Olga Ilkayeva
- Sarah W. Stedman Nutrition and Metabolism Center, Duke University, Durham, NC 27701, USA
| | - Anastasia Coldren
- Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Greg Poffenberger
- Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Alena Shostak
- Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Michael C Semich
- Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Kristie I Aamodt
- Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Neil Phillips
- Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Hai Yan
- REMD Biotherapeutics, Camarillo, CA 93012, USA
| | - Ernesto Bernal-Mizrachi
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Miami, Miami, FL 33146, USA
| | - Jackie D Corbin
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Kasey C Vickers
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Division of Cardiovascular Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Shawn E Levy
- HudsonAlpha Institute for Biotechnology, Huntsville, AL 35806, USA
| | - Chunhua Dai
- Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Christopher Newgard
- Sarah W. Stedman Nutrition and Metabolism Center, Duke University, Durham, NC 27701, USA
| | - Wei Gu
- Amgen, Thousand Oaks, CA 91320, USA
| | - Roland Stein
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Wenbiao Chen
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Alvin C Powers
- Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN 37232, USA; VA Tennessee Valley Healthcare, Nashville, TN 37212, USA.
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21
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Kim HK, Kwon O, Park KH, Lee KJ, Youn BS, Kim SW, Kim MS. Angiopoietin-like peptide 4 regulates insulin secretion and islet morphology. Biochem Biophys Res Commun 2017; 485:113-118. [PMID: 28188788 DOI: 10.1016/j.bbrc.2017.02.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 02/06/2017] [Indexed: 11/29/2022]
Abstract
Insulin secretion from pancreatic islet β-cells is primarily regulated by the blood glucose level, and also modulated by a number of biological factors produced inside the islets or released from remote organs. Previous studies have shown that angiopoietin-like protein 4 (Angptl4) controls glucose and lipid metabolism through its actions in the liver, adipose tissue, and skeletal muscles. In this present study, we investigated the possible role of Angptl4 in the regulation of insulin secretion from pancreatic islets. Angptl4 was found to be highly expressed in the α-cells but not β-cells of rodent islets. Moreover, treatment of rodent islets with Angptl4 peptide potentiated glucose-stimulated insulin secretion through a protein kinase A-dependent mechanism. Consistently, Angptl4 knockout mice showed impaired glucose tolerance. In the cultured islets from Angptl4 knockout mice, glucose-stimulated insulin secretion was significantly lower than in islets from wild type mice. Angptl4 peptide replacement partially reversed this reduction. Moreover, Angptl4 knockout mice had dysmorphic islets with abnormally distributed α-cells. In contrast, the β-cell mass and distribution were not significantly altered in these knockout mice. Our current data collectively suggest that Angptl4 may play a critical role in the regulation of insulin secretion and islet morphogenesis.
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Affiliation(s)
- Hyun-Kyong Kim
- Asan Institute for Life Sciences, University of Ulsan College of Medicine, Seoul 05505, South Korea
| | - Obin Kwon
- Asan Institute for Life Sciences, University of Ulsan College of Medicine, Seoul 05505, South Korea; Division of Endocrinology and Metabolism, University of Ulsan College of Medicine, Seoul 05505, South Korea
| | - Kyeong-Han Park
- Department of Anatomy, Kangwon National University School of Medicine, Chuncheon-si, Gangwon-do 24341, South Korea
| | - Kyung Jin Lee
- Department of Pharmacology, University of Ulsan College of Medicine, Seoul 05505, South Korea
| | | | - Seung-Whan Kim
- Department of Pharmacology, University of Ulsan College of Medicine, Seoul 05505, South Korea
| | - Min-Seon Kim
- Asan Institute for Life Sciences, University of Ulsan College of Medicine, Seoul 05505, South Korea; Division of Endocrinology and Metabolism, University of Ulsan College of Medicine, Seoul 05505, South Korea.
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22
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Holst JJ, Wewer Albrechtsen NJ, Pedersen J, Knop FK. Glucagon and Amino Acids Are Linked in a Mutual Feedback Cycle: The Liver-α-Cell Axis. Diabetes 2017; 66:235-240. [PMID: 28108603 DOI: 10.2337/db16-0994] [Citation(s) in RCA: 130] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 10/31/2016] [Indexed: 11/13/2022]
Abstract
Glucagon is usually viewed as an important counterregulatory hormone in glucose metabolism, with actions opposing those of insulin. Evidence exists that shows glucagon is important for minute-to-minute regulation of postprandial hepatic glucose production, although conditions of glucagon excess or deficiency do not cause changes compatible with this view. In patients with glucagon-producing tumors (glucagonomas), the most conspicuous signs are skin lesions (necrolytic migratory erythema), while in subjects with inactivating mutations of the glucagon receptor, pancreatic swelling may be the first sign; neither condition is necessarily associated with disturbed glucose metabolism. In glucagonoma patients, amino acid turnover and ureagenesis are greatly accelerated, and low plasma amino acid levels are probably at least partly responsible for the necrolytic migratory erythema, which resolves after amino acid administration. In patients with receptor mutations (and in knockout mice), pancreatic swelling is due to α-cell hyperplasia with gross hypersecretion of glucagon, which according to recent groundbreaking research may result from elevated amino acid levels. Additionally, solid evidence indicates that ureagenesis, and thereby amino acid levels, is critically controlled by glucagon. Together, this constitutes a complete endocrine system; feedback regulation involving amino acids regulates α-cell function and secretion, while glucagon, in turn, regulates amino acid turnover.
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Affiliation(s)
- Jens J Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Nicolai J Wewer Albrechtsen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jens Pedersen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Filip K Knop
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Center for Diabetes Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark
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Asghar ZA, Cusumano A, Yan Z, Remedi MS, Moley KH. Reduced islet function contributes to impaired glucose homeostasis in fructose-fed mice. Am J Physiol Endocrinol Metab 2017; 312:E109-E116. [PMID: 28028036 PMCID: PMC5336566 DOI: 10.1152/ajpendo.00279.2016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 12/19/2016] [Accepted: 12/19/2016] [Indexed: 01/09/2023]
Abstract
Increased sugar consumption, particularly fructose, in the form of sweetened beverages and sweeteners in our diet adversely affects metabolic health. Because these effects are associated with features of the metabolic syndrome in humans, the direct effect of fructose on pancreatic islet function is unknown. Therefore, we examined the islet phenotype of mice fed excess fructose. Fructose-fed mice exhibited fasting hyperglycemia and glucose intolerance but not hyperinsulinemia, dyslipidemia, or hyperuricemia. Islet function was impaired, with decreased glucose-stimulated insulin secretion and increased glucagon secretion and high fructose consumption leading to α-cell proliferation and upregulation of the fructose transporter GLUT5, which was localized only in α-cells. Our studies demonstrate that excess fructose consumption contributes to hyperglycemia by affecting both β- and α-cells of islets in mice.
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Affiliation(s)
- Zeenat A Asghar
- Department of Obstetrics and Gynecology, Washington University in St. Louis School of Medicine, St. Louis, Missouri; and
| | - Andrew Cusumano
- Department of Obstetrics and Gynecology, Washington University in St. Louis School of Medicine, St. Louis, Missouri; and
| | - Zihan Yan
- Department of Medicine, Washington University in St. Louis School of Medicine, St. Louis, Missouri
| | - Maria S Remedi
- Department of Medicine, Washington University in St. Louis School of Medicine, St. Louis, Missouri
| | - Kelle H Moley
- Department of Obstetrics and Gynecology, Washington University in St. Louis School of Medicine, St. Louis, Missouri; and
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Angptl4 does not control hyperglucagonemia or α-cell hyperplasia following glucagon receptor inhibition. Proc Natl Acad Sci U S A 2017; 114:2747-2752. [PMID: 28143927 DOI: 10.1073/pnas.1620989114] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Genetic disruption or pharmacologic inhibition of glucagon signaling effectively lowers blood glucose but results in compensatory glucagon hypersecretion involving expansion of pancreatic α-cell mass. Ben-Zvi et al. recently reported that angiopoietin-like protein 4 (Angptl4) links glucagon receptor inhibition to hyperglucagonemia and α-cell proliferation [Ben-Zvi et al. (2015) Proc Natl Acad Sci USA 112:15498-15503]. Angptl4 is a secreted protein and inhibitor of lipoprotein lipase-mediated plasma triglyceride clearance. We report that Angptl4-/- mice treated with an anti-glucagon receptor monoclonal antibody undergo elevation of plasma glucagon levels and α-cell expansion similar to wild-type mice. Overexpression of Angptl4 in liver of mice caused a 8.6-fold elevation in plasma triglyceride levels, but did not alter plasma glucagon levels or α-cell mass. Furthermore, administration of glucagon receptor-blocking antibody to healthy individuals increased plasma glucagon and amino acid levels, but did not change circulating Angptl4 concentration. These data show that Angptl4 does not link glucagon receptor inhibition to compensatory hyperglucagonemia or expansion of α-cell mass, and that it cannot be given to induce such secretion and growth. The reduction of plasma triglyceride levels in Angptl4-/- mice and increase following Angptl4 overexpression suggest that changes in plasma triglyceride metabolism do not regulate α-cells in the pancreas. Our findings corroborate recent data showing that increased plasma amino acids and their transport into α-cells link glucagon receptor blockage to α-cell hyperplasia.
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Abstract
Lipoprotein lipase (LPL) is a rate-limiting enzyme for hydrolysing circulating triglycerides (TG) into free fatty acids that are taken up by peripheral tissues. Postprandial LPL activity rises in white adipose tissue (WAT), but declines in the heart and skeletal muscle, thereby directing circulating TG to WAT for storage; the reverse is true during fasting. However, the mechanism for the tissue-specific regulation of LPL activity during the fed–fast cycle has been elusive. Recent identification of lipasin/angiopoietin-like 8 (Angptl8), a feeding-induced hepatokine, together with Angptl3 and Angptl4, provides intriguing, yet puzzling, insights, because all the three Angptl members are LPL inhibitors, and the deficiency (overexpression) of any one causes hypotriglyceridaemia (hypertriglyceridaemia). Then, why does nature need all of the three? Our recent data that Angptl8 negatively regulates LPL activity specifically in cardiac and skeletal muscles suggest an Angptl3-4-8 model: feeding induces Angptl8, activating the Angptl8–Angptl3 pathway, which inhibits LPL in cardiac and skeletal muscles, thereby making circulating TG available for uptake by WAT, in which LPL activity is elevated owing to diminished Angptl4; the reverse is true during fasting, which suppresses Angptl8 but induces Angptl4, thereby directing TG to muscles. The model suggests a general framework for how TG trafficking is regulated.
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Affiliation(s)
- Ren Zhang
- Center for Molecular Medicine and Genetics, School of Medicine, Wayne State University, 540 East Canfield Street, Detroit, MI 48201, USA
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The downregulation of ANGPTL4 inhibits the migration and proliferation of tongue squamous cell carcinoma. Arch Oral Biol 2016; 71:144-149. [PMID: 27505034 DOI: 10.1016/j.archoralbio.2016.07.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 07/24/2016] [Accepted: 07/27/2016] [Indexed: 12/27/2022]
Abstract
OBJECTIVE Tongue squamous cell carcinoma (TSCC) is the most common malignant cancer in the oral cavity, with a high rate of metastasis to the neck lymphoid node. Angiopoietin-like protein 4 (ANGPTL4) and microvessel density (MVD) may be novel indicators for tumor metastasis. The aim of the present study was to investigate the expression and function of ANGPTL4 in TSCC and the relationship between ANGPTL4 and MVD. METHODS The expression levels of ANGPTL4 and MVD (CD34) were analyzed in 65 TSCC specimens and the adjacent non-cancerous tissues using immunohistochemistry (IHC). siRNA was delivered into TSCCA cells to downregulate ANGPTL4 expression. Subsequently, validation with real-time RT-PCR and western blot analyses was performed to analyze ANGPTL4 expression levels. In addition, a proliferation assay, migration and invasion assays were carried out. RESULTS ANGPTL4 expression was associated with tumor stage, lymph node metastasis and MVD expression. Cox regression analysis showed that high levels of ANGPTL4 expression were closely associated with poor survival time. In vitro analyses using qRT-PCR and western blot confirmed that ANGPTL4 was successfully inhibited in TSCCA cells. Suppressing ANGPTL4 resulted in the inhibition of cell proliferation and migration, but neither invasion nor cisplatin resistance was significantly affected. CONCLUSION High expression levels of ANGPTL4 are associated with the T stage, lymphatic metastasis, angiogenesis and poor overall survival in TSCC patients. The downregulation of ANGPTL4 inhibits the migration and proliferation of cells in TSCC. Taken together, ANGPTL4 may serve as a novel biomarker and therapeutic target for TSCC.
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Rhyu J, Yu R. Mahvash disease: an autosomal recessive hereditary pancreatic neuroendocrine tumor syndrome. INTERNATIONAL JOURNAL OF ENDOCRINE ONCOLOGY 2016. [DOI: 10.2217/ije-2016-0005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Affiliation(s)
- Jane Rhyu
- Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, USA
- Division of Endocrinology, Cedars-Sinai Medical Center, Los Angeles, CA, USA; current address Department of Medicine, UCLA David Geffen School of Medicine, Los Angeles, CA, USA,
| | - Run Yu
- Division of Endocrinology, Cedars-Sinai Medical Center, Los Angeles, CA, USA; current address Department of Medicine, UCLA David Geffen School of Medicine, Los Angeles, CA, USA,
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