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Huang P, Zhu Y, Qin J. Research advances in understanding crosstalk between organs and pancreatic β-cell dysfunction. Diabetes Obes Metab 2024. [PMID: 39044309 DOI: 10.1111/dom.15787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2024] [Revised: 06/25/2024] [Accepted: 06/26/2024] [Indexed: 07/25/2024]
Abstract
Obesity has increased dramatically worldwide. Being overweight or obese can lead to various conditions, including dyslipidaemia, hypertension, glucose intolerance and metabolic syndrome (MetS), which may further lead to type 2 diabetes mellitus (T2DM). Previous studies have identified a link between β-cell dysfunction and the severity of MetS, with multiple organs and tissues affected. Identifying the associations between pancreatic β-cell dysfunction and organs is critical. Research has focused on the interaction between the liver, gut and pancreatic β-cells. However, the mechanisms and related core targets are still not perfectly elucidated. The aims of this review were to summarize the mechanisms of β-cell dysfunction and to explore the potential pathogenic pathways and targets that connect the liver, gut, adipose tissue, muscle, and brain to pancreatic β-cell dysfunction.
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Affiliation(s)
- Peng Huang
- Department of Traditional Chinese Medicine, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
| | - Yunling Zhu
- Department of Traditional Chinese Medicine, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
| | - Jian Qin
- Department of Traditional Chinese Medicine, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
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2
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Chernysheva МB, Ruchko ЕS, Karimova МV, Vorotelyak ЕA, Vasiliev АV. Development, regeneration, and physiological expansion of functional β-cells: Cellular sources and regulators. Front Cell Dev Biol 2024; 12:1424278. [PMID: 39045459 PMCID: PMC11263198 DOI: 10.3389/fcell.2024.1424278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2024] [Accepted: 06/18/2024] [Indexed: 07/25/2024] Open
Abstract
Pancreatic regeneration is a complex process observed in both normal and pathological conditions. The aim of this review is to provide a comprehensive understanding of the emergence of a functionally active population of insulin-secreting β-cells in the adult pancreas. The renewal of β-cells is governed by a multifaceted interaction between cellular sources of genetic and epigenetic factors. Understanding the development and heterogeneity of β-cell populations is crucial for functional β-cell regeneration. The functional mass of pancreatic β-cells increases in situations such as pregnancy and obesity. However, the specific markers of mature β-cell populations and postnatal pancreatic progenitors capable of increasing self-reproduction in these conditions remain to be elucidated. The capacity to regenerate the β-cell population through various pathways, including the proliferation of pre-existing β-cells, β-cell neogenesis, differentiation of β-cells from a population of progenitor cells, and transdifferentiation of non-β-cells into β-cells, reveals crucial molecular mechanisms for identifying cellular sources and inducers of functional cell renewal. This provides an opportunity to identify specific cellular sources and mechanisms of regeneration, which could have clinical applications in treating various pathologies, including in vitro cell-based technologies, and deepen our understanding of regeneration in different physiological conditions.
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Affiliation(s)
- М. B. Chernysheva
- Cell Biology Laboratory, Koltzov Institute of Developmental Biology, Moscow, Russia
| | - Е. S. Ruchko
- Cell Biology Laboratory, Koltzov Institute of Developmental Biology, Moscow, Russia
| | - М. V. Karimova
- Cell Biology Laboratory, Koltzov Institute of Developmental Biology, Moscow, Russia
- Department of Biology and Biotechnologies Charles Darwin, The Sapienza University of Rome, Rome, Italy
| | - Е. A. Vorotelyak
- Cell Biology Laboratory, Koltzov Institute of Developmental Biology, Moscow, Russia
| | - А. V. Vasiliev
- Cell Biology Laboratory, Koltzov Institute of Developmental Biology, Moscow, Russia
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3
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De la Cruz-Color L, Dominguez-Rosales JA, Maldonado-González M, Ruíz-Madrigal B, Sánchez Muñoz MP, Zaragoza-Guerra VA, Espinoza-Padilla VH, Ruelas-Cinco EDC, Ramírez-Meza SM, Torres Baranda JR, González-Gutiérrez MDR, Hernandez Nazara ZH. Evidence That Peripheral Leptin Resistance in Omental Adipose Tissue and Liver Correlates with MASLD in Humans. Int J Mol Sci 2024; 25:6420. [PMID: 38928125 PMCID: PMC11203746 DOI: 10.3390/ijms25126420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2024] [Revised: 06/04/2024] [Accepted: 06/06/2024] [Indexed: 06/28/2024] Open
Abstract
Leptin regulates lipid metabolism, maximizing insulin sensitivity; however, peripheral leptin resistance is not fully understood, and its contribution to metabolic dysfunction-associated steatotic liver disease (MASLD) is unclear. This study evaluated the contribution of the leptin axis to MASLD in humans. Forty-three participants, mostly female (86.04%), who underwent cholecystectomy were biopsied. Of the participants, 24 were healthy controls, 8 had MASLD, and 11 had metabolic dysfunction-associated steatohepatitis (MASH). Clinical and biochemical data and the gene expression of leptin, leptin receptor (LEPR), suppressor of cytokine signaling 3 (SOCS3), sterol regulatory element-binding transcription factor 1 (SREBF1), stearoyl-CoA desaturase-1 (SCD1), and patatin-like phospholipase domain-containing protein 2 (PNPLA2), were determined from liver and adipose tissue. Higher serum leptin and LEPR levels in the omental adipose tissue (OAT) and liver with MASH were found. In the liver, LEPR was positively correlated with leptin expression in adipose tissue, and SOCS3 was correlated with SREBF1-SCD1. In OAT, SOCS3 was correlated with insulin resistance and transaminase enzymes (p < 0.05 for all. In conclusion, we evidenced the correlation between the peripheral leptin resistance axis in OAT-liver crosstalk and the complications of MASLD in humans.
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Affiliation(s)
- Lucia De la Cruz-Color
- Centro de Investigación en Biotecnología Microbiana y Alimentaria, División de Desarrollo Biotecnológico, Centro Universitario de la Ciénega, Universidad de Guadalajara, Ocotlán 47820, C.P., Mexico;
- Instituto de Investigación en Enfermedades Crónicas Degenerativas, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara 44340, C.P., Mexico (V.H.E.-P.)
| | - Jose Alfredo Dominguez-Rosales
- Instituto de Investigación en Enfermedades Crónicas Degenerativas, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara 44340, C.P., Mexico (V.H.E.-P.)
| | - Montserrat Maldonado-González
- Laboratorio de Investigación en Microbiología, Departamento de Microbiología y Patología, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara 44340, C.P., Mexico; (M.M.-G.); (B.R.-M.); (J.R.T.B.)
| | - Bertha Ruíz-Madrigal
- Laboratorio de Investigación en Microbiología, Departamento de Microbiología y Patología, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara 44340, C.P., Mexico; (M.M.-G.); (B.R.-M.); (J.R.T.B.)
| | - Martha P. Sánchez Muñoz
- Nuevo Hospital Civil de Guadalajara Dr. Juan I. Menchaca, Unidad de Cirugía Bariátrica y Metabólica, Guadalajara 44340, C.P., Mexico;
| | - Vianney Alejandrina Zaragoza-Guerra
- Instituto Tecnológico y de Estudios Superiores de Monterrey, Campus Guadalajara, Escuela de Medicina y Ciencias de la Salud, Zapopan 45201, C.P., Mexico; (V.A.Z.-G.); (M.d.R.G.-G.)
| | - Victor H. Espinoza-Padilla
- Instituto de Investigación en Enfermedades Crónicas Degenerativas, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara 44340, C.P., Mexico (V.H.E.-P.)
| | | | - Sandra M. Ramírez-Meza
- Coordinación de la Licenciatura en Nutrición, División de Estudios de la Salud Centro Universitario de los Valles, Universidad de Guadalajara, Ameca Km. 45.5, Ameca 46600, C.P., Mexico;
| | - José R. Torres Baranda
- Laboratorio de Investigación en Microbiología, Departamento de Microbiología y Patología, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara 44340, C.P., Mexico; (M.M.-G.); (B.R.-M.); (J.R.T.B.)
| | - María del R. González-Gutiérrez
- Instituto Tecnológico y de Estudios Superiores de Monterrey, Campus Guadalajara, Escuela de Medicina y Ciencias de la Salud, Zapopan 45201, C.P., Mexico; (V.A.Z.-G.); (M.d.R.G.-G.)
| | - Zamira Helena Hernandez Nazara
- Instituto de Investigación en Enfermedades Crónicas Degenerativas, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara 44340, C.P., Mexico (V.H.E.-P.)
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Portillo Siqueiros EY, Santellano-Estrada E, Flores Villalobos MÁ, Roacho Soto MG, Martínez Flórez S. [Effects of zinc and resveratrol as modulators of leptin response in adults with obesity]. NUTR HOSP 2024. [PMID: 38896121 DOI: 10.20960/nh.05177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/21/2024] Open
Abstract
INTRODUCTION fat tissue is an organ with endocrine function, where the hormone leptin (LEP) is identified. This peptide regulates appetite, the immune system, vascular functions and insulin sensitivity. Zinc (Zn) and resveratrol (RES) have potential effects on adipose tissue. OBJECTIVE to know if the combined administration of Zn and RES has any effect on blood leptin quantification in obese people. METHODS longitudinal experimental study, controlled clinical trial design, randomized, double blind. Randomized formation of four groups: T1 (Zn 50 mg), T2 (control), T3 (RES 500 mg), T4 (Zn 50 mg and RES 500 mg) with a supplementation period of 60 days. Blood samples were taken and glucose (GLU), leptin (LEP) and lipids (HDL, LDL, TGL) were quantified before and after exposure to the study elements. RESULTS age 34 (± 7) years. In T-tests, significance in GLU (p = 0.04) and LEP (p = 0.055). By exposure groups: GLU at T1 (p = 0.03) and T2 (p = 0.031); at LEP at T4 (p = 0.024). Lipids by groups: HDL at T3 (p = 0.039) and T4 (p = 0.014). ANOVA, HDL (p = 0.06). Pearson, HDL (p = 0.07) and LDL (p = 0.09). CONCLUSION zinc and resveratrol showed promise as agents in modulating leptin and glucose signaling, confirming that they work in a proportional manner and provide benefits for cardiac health, but more exposure time is needed to see if they impact energy balance homeostasis.
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Tricò D, Chiriacò M, Nouws J, Vash-Margita A, Kursawe R, Tarabra E, Galderisi A, Natali A, Giannini C, Hellerstein M, Ferrannini E, Caprio S. Alterations in Adipose Tissue Distribution, Cell Morphology, and Function Mark Primary Insulin Hypersecretion in Youth With Obesity. Diabetes 2024; 73:941-952. [PMID: 37870826 PMCID: PMC11109779 DOI: 10.2337/db23-0450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 10/16/2023] [Indexed: 10/24/2023]
Abstract
Excessive insulin secretion independent of insulin resistance, defined as primary hypersecretion, is associated with obesity and an unfavorable metabolic phenotype. We examined the characteristics of adipose tissue of youth with primary insulin hypersecretion and the longitudinal metabolic alterations influenced by the complex adipo-insular interplay. In a multiethnic cohort of adolescents with obesity but without diabetes, primary insulin hypersecretors had enhanced model-derived β-cell glucose sensitivity and rate sensitivity but worse glucose tolerance, despite similar demographics, adiposity, and insulin resistance measured by both oral glucose tolerance test and euglycemic-hyperinsulinemic clamp. Hypersecretors had greater intrahepatic and visceral fat depots at abdominal MRI, hypertrophic abdominal subcutaneous adipocytes, higher free fatty acid and leptin serum levels per fat mass, and faster in vivo lipid turnover assessed by a long-term 2H2O labeling protocol. At 2-year follow-up, hypersecretors had greater fat accrual and a threefold higher risk for abnormal glucose tolerance, while individuals with hypertrophic adipocytes or higher leptin levels showed enhanced β-cell glucose sensitivity. Primary insulin hypersecretion is associated with marked alterations in adipose tissue distribution, cellularity, and lipid dynamics, independent of whole-body adiposity and insulin resistance. Pathogenetic insight into the metabolic crosstalk between β-cell and adipocyte may help to identify individuals at risk for chronic hyperinsulinemia, body weight gain, and glucose intolerance. ARTICLE HIGHLIGHTS
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Affiliation(s)
- Domenico Tricò
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
- Laboratory of Metabolism, Nutrition, and Atherosclerosis, University of Pisa, Pisa, Italy
| | - Martina Chiriacò
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
- Laboratory of Metabolism, Nutrition, and Atherosclerosis, University of Pisa, Pisa, Italy
| | - Jessica Nouws
- Department of Pediatrics, Yale School of Medicine, New Haven, CT
| | - Alla Vash-Margita
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale School of Medicine, New Haven, CT
| | - Romy Kursawe
- The Jackson Laboratory for Genomic Medicine, Farmington, CT
| | | | | | - Andrea Natali
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
- Laboratory of Metabolism, Nutrition, and Atherosclerosis, University of Pisa, Pisa, Italy
| | - Cosimo Giannini
- Department of Pediatrics, University of Chieti “G. d’Annunzio,” Chieti, Italy
| | - Marc Hellerstein
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, Berkeley, CA
| | - Ele Ferrannini
- Institute of Clinical Physiology, National Research Council, Pisa, Italy
| | - Sonia Caprio
- Department of Pediatrics, Yale School of Medicine, New Haven, CT
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Becattini B, Molinaro A, Henricsson M, Borén J, Solinas G. Adipocyte PI3K links adipostasis with baseline insulin secretion at fasting through an adipoincretin effect. Cell Rep 2024; 43:114132. [PMID: 38656871 DOI: 10.1016/j.celrep.2024.114132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 03/06/2024] [Accepted: 04/04/2024] [Indexed: 04/26/2024] Open
Abstract
Insulin-PI3K signaling controls insulin secretion. Understanding this feedback mechanism is crucial for comprehending how insulin functions. However, the role of adipocyte insulin-PI3K signaling in controlling insulin secretion in vivo remains unclear. Using adipocyte-specific PI3Kα knockout mice (PI3KαAdQ) and a panel of isoform-selective PI3K inhibitors, we show that PI3Kα and PI3Kβ activities are functionally redundant in adipocyte insulin signaling. PI3Kβ-selective inhibitors have no effect on adipocyte AKT phosphorylation in control mice but blunt it in adipocytes of PI3KαAdQ mice, demonstrating adipocyte-selective pharmacological PI3K inhibition in the latter. Acute adipocyte-selective PI3K inhibition increases serum free fatty acid (FFA) and potently induces insulin secretion. We name this phenomenon the adipoincretin effect. The adipoincretin effect operates in fasted mice with increasing FFA and decreasing glycemia, indicating that it is not primarily a control system for blood glucose. This feedback control system defines the rates of adipose tissue lipolysis and chiefly controls basal insulin secretion during fasting.
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Affiliation(s)
- Barbara Becattini
- Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Angela Molinaro
- Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Marcus Henricsson
- Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Jan Borén
- Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Giovanni Solinas
- Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden.
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Algañarás M, Román CL, Gagliardino JJ, Maiztegui B, Flores LE. Structural modifications of INGAP-PP present in HTD4010 peptide potentiate its effect on rat islet gene expression and insulin secretion. Peptides 2024; 173:171148. [PMID: 38215942 DOI: 10.1016/j.peptides.2024.171148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 12/28/2023] [Accepted: 01/02/2024] [Indexed: 01/14/2024]
Abstract
Type 2 diabetes (T2D) is characterized by peripheral insulin resistance and altered insulin secretion due to a progressive loss of β-cell mass and function. Today, most antidiabetic agents are designed to resolve impaired insulin secretion and/or insulin resistance, and only GLP-1-based formulations contribute to stopping the decline in β-cell mass. HTD4010, a peptide carrying two modifications of the amino acid sequence of INGAP-PP (N-terminus acetylation and substitution of Asn13 by Ala) showed greater plasma stability and could be a good candidate for proposal as a drug that could improve β cell mass and function lost in T2D. In the present study, we showed that HTD4010 included in the culture media of normal rat islets at a dose 100 times lower than that used for INGAP-PP was able to modulate, in the same way as the original peptide, both insulin secretion in response to glucose and the expression of key genes related to insular function, insulin and leptin intracellular pathways, neogenesis, apoptosis, and inflammatory response. Our results confirm the positive effect of HTD4010 on β-cell function and gene expression of factors involved in the maintenance of β-cell mass. Although new assays in animal models of prediabetes and T2D must be performed to be conclusive, our results are very encouraging, and they suggest that the use of HTD4010 at a dose 100 times lower than that of INGAP-PP could minimize its side effects in a future clinical trial.
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Affiliation(s)
- Macarena Algañarás
- CENEXA. Centro de Endocrinología Experimental y Aplicada (UNLP-CONICET, CeAs CICPBA), Facultad de Ciencias Médicas UNLP, La Plata, Argentina
| | - Carolina L Román
- CENEXA. Centro de Endocrinología Experimental y Aplicada (UNLP-CONICET, CeAs CICPBA), Facultad de Ciencias Médicas UNLP, La Plata, Argentina
| | - Juan J Gagliardino
- CENEXA. Centro de Endocrinología Experimental y Aplicada (UNLP-CONICET, CeAs CICPBA), Facultad de Ciencias Médicas UNLP, La Plata, Argentina
| | - Bárbara Maiztegui
- CENEXA. Centro de Endocrinología Experimental y Aplicada (UNLP-CONICET, CeAs CICPBA), Facultad de Ciencias Médicas UNLP, La Plata, Argentina
| | - Luis E Flores
- CENEXA. Centro de Endocrinología Experimental y Aplicada (UNLP-CONICET, CeAs CICPBA), Facultad de Ciencias Médicas UNLP, La Plata, Argentina.
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Zhang J, Katada K, Mosleh E, Yuhas A, Peng G, Golson ML. The leptin receptor has no role in delta-cell control of beta-cell function in the mouse. Front Endocrinol (Lausanne) 2023; 14:1257671. [PMID: 37850099 PMCID: PMC10577419 DOI: 10.3389/fendo.2023.1257671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 09/05/2023] [Indexed: 10/19/2023] Open
Abstract
Introduction Leptin inhibits insulin secretion from isolated islets from multiple species, but the cell type that mediates this process remains elusive. Several mouse models have been used to explore this question. Ablation of the leptin receptor (Lepr) throughout the pancreatic epithelium results in altered glucose homeostasis and ex vivo insulin secretion and Ca2+ dynamics. However, Lepr removal from neither alpha nor beta cells mimics this result. Moreover, scRNAseq data has revealed an enrichment of LEPR in human islet delta cells. Methods We confirmed LEPR upregulation in human delta cells by performing RNAseq on fixed, sorted beta and delta cells. We then used a mouse model to test whether delta cells mediate the diminished glucose-stimulated insulin secretion in response to leptin. Results Ablation of Lepr within mouse delta cells did not change glucose homeostasis or insulin secretion, whether mice were fed a chow or high-fat diet. We further show, using a publicly available scRNAseq dataset, that islet cells expressing Lepr lie within endothelial cell clusters. Conclusions In mice, leptin does not influence beta-cell function through delta cells.
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Affiliation(s)
- Jia Zhang
- Department of Genetics, University of Pennsylvania, Philadephia, PA, United States
| | - Kay Katada
- School of Medicine, University of Pennsylvania, Philadephia, PA, United States
| | - Elham Mosleh
- Department of Genetics, University of Pennsylvania, Philadephia, PA, United States
- School of Medicine, University of Pennsylvania, Philadephia, PA, United States
| | - Andrew Yuhas
- Department of Genetics, University of Pennsylvania, Philadephia, PA, United States
- School of Medicine, University of Pennsylvania, Philadephia, PA, United States
| | - Guihong Peng
- Department of Medicine, Divison of Endocrinology, Diabetes, and Metabolism, Johns Hopkins University, Baltimore, MD, United States
| | - Maria L. Golson
- Department of Genetics, University of Pennsylvania, Philadephia, PA, United States
- School of Medicine, University of Pennsylvania, Philadephia, PA, United States
- Department of Medicine, Divison of Endocrinology, Diabetes, and Metabolism, Johns Hopkins University, Baltimore, MD, United States
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Kim J, Oh CM, Kim H. The Interplay of Adipokines and Pancreatic Beta Cells in Metabolic Regulation and Diabetes. Biomedicines 2023; 11:2589. [PMID: 37761031 PMCID: PMC10526203 DOI: 10.3390/biomedicines11092589] [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: 08/30/2023] [Revised: 09/19/2023] [Accepted: 09/20/2023] [Indexed: 09/29/2023] Open
Abstract
The interplay between adipokines and pancreatic beta cells, often referred to as the adipo-insular axis, plays a crucial role in regulating metabolic homeostasis. Adipokines are signaling molecules secreted by adipocytes that have profound effects on several physiological processes. Adipokines such as adiponectin, leptin, resistin, and visfatin influence the function of pancreatic beta cells. The reciprocal communication between adipocytes and beta cells is remarkable. Insulin secreted by beta cells affects adipose tissue metabolism, influencing lipid storage and lipolysis. Conversely, adipokines released from adipocytes can influence beta cell function and survival. Chronic obesity and insulin resistance can lead to the release of excess fatty acids and inflammatory molecules from the adipose tissue, contributing to beta cell dysfunction and apoptosis, which are key factors in developing type 2 diabetes. Understanding the complex interplay of the adipo-insular axis provides insights into the mechanisms underlying metabolic regulation and pathogenesis of metabolic disorders. By elucidating the molecular mediators involved in this interaction, new therapeutic targets and strategies may emerge to reduce the risk and progression of diseases, such as type 2 diabetes and its associated complications. This review summarizes the interactions between adipokines and pancreatic beta cells, and their roles in the pathogenesis of diabetes and metabolic diseases.
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Affiliation(s)
- Joon Kim
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea;
| | - Chang-Myung Oh
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea;
| | - Hyeongseok Kim
- Department of Biochemistry, College of Medicine, Chungnam National University, Daejeon 35105, Republic of Korea
- Department of Medical Science, College of Medicine, Chungnam National University, Daejeon 35105, Republic of Korea
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10
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Lavoie O, Michael NJ, Caron A. A critical update on the leptin-melanocortin system. J Neurochem 2023; 165:467-486. [PMID: 36648204 DOI: 10.1111/jnc.15765] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 11/25/2022] [Accepted: 01/09/2023] [Indexed: 01/18/2023]
Abstract
The discovery of leptin in 1994 was an "eureka moment" in the field of neurometabolism that provided new opportunities to better understand the central control of energy balance and glucose metabolism. Rapidly, a prevalent model in the field emerged that pro-opiomelanocortin (POMC) neurons were key in promoting leptin's anorexigenic effects and that the arcuate nucleus of the hypothalamus (ARC) was a key region for the regulation of energy homeostasis. While this model inspired many important discoveries, a growing body of literature indicates that this model is now outdated. In this review, we re-evaluate the hypothalamic leptin-melanocortin model in light of recent advances that directly tackle previous assumptions, with a particular focus on the ARC. We discuss how segregated and heterogeneous these neurons are, and examine how the development of modern approaches allowing spatiotemporal, intersectional, and chemogenetic manipulations of melanocortin neurons has allowed a better definition of the complexity of the leptin-melanocortin system. We review the importance of leptin in regulating glucose homeostasis, but not food intake, through direct actions on ARC POMC neurons. We further highlight how non-POMC, GABAergic neurons mediate leptin's direct effects on energy balance and influence POMC neurons.
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Affiliation(s)
- Olivier Lavoie
- Faculty of Pharmacy, Université Laval, Quebec City, Quebec, Canada.,Quebec Heart and Lung Institute, Quebec City, Quebec, Canada
| | - Natalie Jane Michael
- Faculty of Pharmacy, Université Laval, Quebec City, Quebec, Canada.,Quebec Heart and Lung Institute, Quebec City, Quebec, Canada
| | - Alexandre Caron
- Faculty of Pharmacy, Université Laval, Quebec City, Quebec, Canada.,Quebec Heart and Lung Institute, Quebec City, Quebec, Canada.,Montreal Diabetes Research Center, Montreal, Quebec, Canada
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Xu S, Ye B, Li J, Dou Y, Yu Y, Feng Y, Wang L, Wan DCC, Rong X. Astragalus mongholicus powder, a traditional Chinese medicine formula ameliorate type 2 diabetes by regulating adipoinsular axis in diabetic mice. Front Pharmacol 2022; 13:973927. [PMID: 36046814 PMCID: PMC9420938 DOI: 10.3389/fphar.2022.973927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 07/20/2022] [Indexed: 11/13/2022] Open
Abstract
The global morbidity of obesity and type 2 diabetes mellitus (T2DM) has dramatically increased. Insulin resistance is the most important pathogenesis and therapeutic target of T2DM. The traditional Chinese medicine formula Astragalus mongholicus powder (APF), consists of Astragalus mongholicus Bunge [Fabaceae], Pueraria montana (Lour.) Merr. [Fabaceae], and Morus alba L. [Moraceae] has a long history to be used to treat diabetes in ancient China. This work aims to investigate the effects of APF on diabetic mice and its underlying mechanism. Diabetic mice were induced by High-fat-diet (HFD) and streptozotocin (STZ). The body weight of mice and their plasma levels of glucose, insulin, leptin and lipids were examined. Reverse transcription-polymerase chain reaction, histology, and Western blot analysis were performed to validate the effects of APF on diabetic mice and investigate the underlying mechanism. APF reduced hyperglycemia, hyperinsulinemia, and hyerleptinemia and attenuate the progression of obesity and non-alcoholic fatty liver disease (NAFLD). However, these effects disappeared in leptin deficient ob/ob diabetic mice and STZ-induced insulin deficient type 1 diabetic mice. Destruction of either these hormones would abolish the therapeutic effects of APF. In addition, APF inhibited the protein expression of PTP1B suppressing insulin–leptin sensitivity, the gluconeogenic gene PEPCK, and the adipogenic gene FAS. Therefore, insulin–leptin sensitivity was normalized, and the gluconeogenic and adipogenic genes were suppressed. In conclusion, APF attenuated obesity, NAFLD, and T2DM by regulating the balance of adipoinsular axis in STZ + HFD induced T2DM mice.
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Affiliation(s)
- Siyuan Xu
- Key Laboratory of Glucolipid Metabolic Disorder, Guangdong TCM Key Laboratory for Metabolic Diseases, Guangdong Metabolic Diseases Research Center of Integrated Chinese and Western Medicine, Ministry of Education of China, Institute of Chinese Medicine, Guangdong Pharmaceutical University, Guangzhou, China
| | - Bixian Ye
- Department of Nursing, Medical College of Jiaying University, Meizhou, China
| | - Jinlei Li
- School of Chinese Meteria Medica, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Yonghui Dou
- School of Chinese Meteria Medica, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Yuying Yu
- Key Laboratory of Glucolipid Metabolic Disorder, Guangdong TCM Key Laboratory for Metabolic Diseases, Guangdong Metabolic Diseases Research Center of Integrated Chinese and Western Medicine, Ministry of Education of China, Institute of Chinese Medicine, Guangdong Pharmaceutical University, Guangzhou, China
| | - Yifan Feng
- Key Laboratory of Glucolipid Metabolic Disorder, Guangdong TCM Key Laboratory for Metabolic Diseases, Guangdong Metabolic Diseases Research Center of Integrated Chinese and Western Medicine, Ministry of Education of China, Institute of Chinese Medicine, Guangdong Pharmaceutical University, Guangzhou, China
| | - Lexun Wang
- Key Laboratory of Glucolipid Metabolic Disorder, Guangdong TCM Key Laboratory for Metabolic Diseases, Guangdong Metabolic Diseases Research Center of Integrated Chinese and Western Medicine, Ministry of Education of China, Institute of Chinese Medicine, Guangdong Pharmaceutical University, Guangzhou, China
| | - David Chi-Cheong Wan
- School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Xianglu Rong
- Key Laboratory of Glucolipid Metabolic Disorder, Guangdong TCM Key Laboratory for Metabolic Diseases, Guangdong Metabolic Diseases Research Center of Integrated Chinese and Western Medicine, Ministry of Education of China, Institute of Chinese Medicine, Guangdong Pharmaceutical University, Guangzhou, China
- *Correspondence: Xianglu Rong,
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12
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Reiterer M, Gilani A, Lo JC. Pancreatic Islets as a Target of Adipokines. Compr Physiol 2022; 12:4039-4065. [PMID: 35950650 DOI: 10.1002/cphy.c210044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Rising rates of obesity are intricately tied to the type 2 diabetes epidemic. The adipose tissues can play a central role in protection against or triggering metabolic diseases through the secretion of adipokines. Many adipokines may improve peripheral insulin sensitivity through a variety of mechanisms, thereby indirectly reducing the strain on beta cells and thus improving their viability and functionality. Such effects will not be the focus of this article. Rather, we will focus on adipocyte-secreted molecules that have a direct effect on pancreatic islets. By their nature, adipokines represent potential druggable targets that can reach the islets and improve beta-cell function or preserve beta cells in the face of metabolic stress. © 2022 American Physiological Society. Compr Physiol 12:1-27, 2022.
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Affiliation(s)
- Moritz Reiterer
- Division of Cardiology, Department of Medicine, Weill Center for Metabolic Health, Cardiovascular Research Institute, Weill Cornell Medicine, New York, New York, USA
| | - Ankit Gilani
- Division of Cardiology, Department of Medicine, Weill Center for Metabolic Health, Cardiovascular Research Institute, Weill Cornell Medicine, New York, New York, USA
| | - James C Lo
- Division of Cardiology, Department of Medicine, Weill Center for Metabolic Health, Cardiovascular Research Institute, Weill Cornell Medicine, New York, New York, USA
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13
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Trends in insulin resistance: insights into mechanisms and therapeutic strategy. Signal Transduct Target Ther 2022; 7:216. [PMID: 35794109 PMCID: PMC9259665 DOI: 10.1038/s41392-022-01073-0] [Citation(s) in RCA: 155] [Impact Index Per Article: 77.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 06/15/2022] [Accepted: 06/20/2022] [Indexed: 02/06/2023] Open
Abstract
The centenary of insulin discovery represents an important opportunity to transform diabetes from a fatal diagnosis into a medically manageable chronic condition. Insulin is a key peptide hormone and mediates the systemic glucose metabolism in different tissues. Insulin resistance (IR) is a disordered biological response for insulin stimulation through the disruption of different molecular pathways in target tissues. Acquired conditions and genetic factors have been implicated in IR. Recent genetic and biochemical studies suggest that the dysregulated metabolic mediators released by adipose tissue including adipokines, cytokines, chemokines, excess lipids and toxic lipid metabolites promote IR in other tissues. IR is associated with several groups of abnormal syndromes that include obesity, diabetes, metabolic dysfunction-associated fatty liver disease (MAFLD), cardiovascular disease, polycystic ovary syndrome (PCOS), and other abnormalities. Although no medication is specifically approved to treat IR, we summarized the lifestyle changes and pharmacological medications that have been used as efficient intervention to improve insulin sensitivity. Ultimately, the systematic discussion of complex mechanism will help to identify potential new targets and treat the closely associated metabolic syndrome of IR.
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14
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Grasso P. Harnessing the Power of Leptin: The Biochemical Link Connecting Obesity, Diabetes, and Cognitive Decline. Front Aging Neurosci 2022; 14:861350. [PMID: 35527735 PMCID: PMC9072663 DOI: 10.3389/fnagi.2022.861350] [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: 01/24/2022] [Accepted: 03/21/2022] [Indexed: 12/02/2022] Open
Abstract
In this review, the current understanding of leptin’s role in energy balance, glycemic regulation, and cognitive function is examined, and its involvement in maintaining the homeostatic “harmony” of these physiologies is explored. The effects of exercise on circulating leptin levels are summarized, and the results of clinical application of leptin to metabolic disease and neurologic dysfunction are reviewed. Finally, pre-clinical evidence is presented which suggests that synthetic peptide leptin mimetics may be useful in resolving not only the leptin resistance associated with common obesity and other elements of metabolic syndrome, but also the peripheral insulin resistance characterizing type 2 diabetes mellitus, and the central insulin resistance associated with certain neurologic deficits in humans.
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Affiliation(s)
- Patricia Grasso
- Department of Medicine, Albany Medical College, Albany, NY, United States
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY, United States
- *Correspondence: Patricia Grasso,
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15
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Zhang Y, Wang H, Tu W, Abbas Raza SH, Cao J, Huang J, Wu H, Fan C, Wang S, Zhao Y, Tan Y. Comparative Transcriptome Analysis Provides Insight into Spatio-Temporal Expression Characteristics and Genetic Regulatory Network in Postnatal Developing Subcutaneous and Visceral Fat of Bama Pig. Front Genet 2022; 13:844833. [PMID: 35432468 PMCID: PMC9008487 DOI: 10.3389/fgene.2022.844833] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Accepted: 03/04/2022] [Indexed: 12/23/2022] Open
Abstract
The depot differences between Subcutaneous Fat (SAF) and Visceral Fat (VAF) are critical for human well-being and disease processes in regard to energy metabolism and endocrine function. Miniature pigs (Sus scrofa) are ideal biomedical models for human energy metabolism and obesity due to the similarity of their lipid metabolism with that of humans. However, the regulation of differences in fat deposition and development remains unclear. In this study, the development of SAF and VAF was characterized and compared in Bama pig during postnatal development (infancy, puberty and adulthood), using RNA sequencing techniques (RNA-Seq). The transcriptome of SAF and VAF was profiled and isolated from 1-, 3- and 6 months-old pigs and identified 23,636 expressed genes, of which 1,165 genes were differentially expressed between the depots and/or developmental stages. Upregulated genes in SAF showed significant function and pathway enrichment in the central nervous system development, lipid metabolism, oxidation-reduction process and cell adhesion, whereas genes involved in the immune system, actin cytoskeleton organization, male gonad development and the hippo signaling pathway were preferentially expressed in VAF. Miner analysis of short time-series expression demonstrated that differentiation in gene expression patterns between the two depots corresponded to their distinct responses in sexual development, hormone signaling pathways, lipid metabolism and the hippo signaling pathway. Transcriptome analysis of SAF and VAF suggested that the depot differences in adipose tissue are not only related to lipid metabolism and endocrine function, but are closely associated with sexual development and organ size regulation.
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Affiliation(s)
- Yingying Zhang
- Institute of Animal Husbandry and Veterinary Science, Shanghai Academy of Agricultural Sciences, Shanghai, China
- Shanghai Engineering Research Center of Breeding Pig, Shanghai, China
- *Correspondence: Yingying Zhang, ; Yongsong Tan,
| | - Hongyang Wang
- Institute of Animal Husbandry and Veterinary Science, Shanghai Academy of Agricultural Sciences, Shanghai, China
- Shanghai Engineering Research Center of Breeding Pig, Shanghai, China
| | - Weilong Tu
- Institute of Animal Husbandry and Veterinary Science, Shanghai Academy of Agricultural Sciences, Shanghai, China
- Shanghai Engineering Research Center of Breeding Pig, Shanghai, China
| | | | - Jianguo Cao
- Institute of Animal Husbandry and Veterinary Science, Shanghai Academy of Agricultural Sciences, Shanghai, China
- Shanghai Engineering Research Center of Breeding Pig, Shanghai, China
| | - Ji Huang
- Institute of Animal Husbandry and Veterinary Science, Shanghai Academy of Agricultural Sciences, Shanghai, China
- Shanghai Engineering Research Center of Breeding Pig, Shanghai, China
| | - Huali Wu
- Institute of Animal Husbandry and Veterinary Science, Shanghai Academy of Agricultural Sciences, Shanghai, China
- Shanghai Engineering Research Center of Breeding Pig, Shanghai, China
| | - Chun Fan
- Shanghai Laboratory Animal Research Center, Shanghai, China
| | | | - Ying Zhao
- Shanghai Laboratory Animal Research Center, Shanghai, China
| | - Yongsong Tan
- Institute of Animal Husbandry and Veterinary Science, Shanghai Academy of Agricultural Sciences, Shanghai, China
- Shanghai Engineering Research Center of Breeding Pig, Shanghai, China
- *Correspondence: Yingying Zhang, ; Yongsong Tan,
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16
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Shroff T, Aina K, Maass C, Cipriano M, Lambrecht J, Tacke F, Mosig A, Loskill P. Studying metabolism with multi-organ chips: new tools for disease modelling, pharmacokinetics and pharmacodynamics. Open Biol 2022; 12:210333. [PMID: 35232251 PMCID: PMC8889168 DOI: 10.1098/rsob.210333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Non-clinical models to study metabolism including animal models and cell assays are often limited in terms of species translatability and predictability of human biology. This field urgently requires a push towards more physiologically accurate recapitulations of drug interactions and disease progression in the body. Organ-on-chip systems, specifically multi-organ chips (MOCs), are an emerging technology that is well suited to providing a species-specific platform to study the various types of metabolism (glucose, lipid, protein and drug) by recreating organ-level function. This review provides a resource for scientists aiming to study human metabolism by providing an overview of MOCs recapitulating aspects of metabolism, by addressing the technical aspects of MOC development and by providing guidelines for correlation with in silico models. The current state and challenges are presented for two application areas: (i) disease modelling and (ii) pharmacokinetics/pharmacodynamics. Additionally, the guidelines to integrate the MOC data into in silico models could strengthen the predictive power of the technology. Finally, the translational aspects of metabolizing MOCs are addressed, including adoption for personalized medicine and prospects for the clinic. Predictive MOCs could enable a significantly reduced dependence on animal models and open doors towards economical non-clinical testing and understanding of disease mechanisms.
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Affiliation(s)
- Tanvi Shroff
- NMI Natural and Medical Sciences Institute at the University of Tübingen, Reutlingen, Germany,Department for Microphysiological Systems, Institute for Biomedical Engineering, Faculty of Medicine, Eberhard Karls University Tübingen, Österbergstraße 3, 72074 Tübingen, Germany
| | - Kehinde Aina
- Institute of Biochemistry II, Center for Sepsis Control and Care, Jena University Hospital, Jena, Germany
| | | | - Madalena Cipriano
- Department for Microphysiological Systems, Institute for Biomedical Engineering, Faculty of Medicine, Eberhard Karls University Tübingen, Österbergstraße 3, 72074 Tübingen, Germany
| | - Joeri Lambrecht
- Department of Hepatology and Gastroenterology, Charité University Medicine Berlin, Campus Virchow Klinikum and Campus Charité Mitte, Berlin, Germany
| | - Frank Tacke
- Department of Hepatology and Gastroenterology, Charité University Medicine Berlin, Campus Virchow Klinikum and Campus Charité Mitte, Berlin, Germany
| | - Alexander Mosig
- Institute of Biochemistry II, Center for Sepsis Control and Care, Jena University Hospital, Jena, Germany
| | - Peter Loskill
- NMI Natural and Medical Sciences Institute at the University of Tübingen, Reutlingen, Germany,Department for Microphysiological Systems, Institute for Biomedical Engineering, Faculty of Medicine, Eberhard Karls University Tübingen, Österbergstraße 3, 72074 Tübingen, Germany,3R-Center for In vitro Models and Alternatives to Animal Testing, Eberhard Karls University Tübingen, Tübingen, Germany
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17
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The role of leptin and low testosterone in obesity. Int J Impot Res 2022; 34:704-713. [DOI: 10.1038/s41443-022-00534-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Accepted: 01/21/2022] [Indexed: 12/29/2022]
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18
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Nguyen NN, Singh RG, Petrov MS. Association between Intrapancreatic Fat Deposition and the Leptin/Ghrelin Ratio in the Fasted and Postprandial States. ANNALS OF NUTRITION AND METABOLISM 2021; 78:14-20. [PMID: 34710871 DOI: 10.1159/000520068] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 10/02/2021] [Indexed: 11/19/2022]
Abstract
BACKGROUND The clinical relevance of excess intrapancreatic fat deposition (IPFD) is increasingly appreciated. Leptin and ghrelin are key players in the regulation of food intake, energy balance, and body fat mass. The aim was to investigate the associations of the leptin/ghrelin ratio and its components with IPFD. METHODS All participants underwent magnetic resonance imaging on a 3T scanner to quantify IPFD. Both fasting and postprandial blood samples were analyzed for leptin and acylated ghrelin. Linear regression analysis was conducted, accounting for visceral/subcutaneous fat volume ratio, glycated hemoglobin, and other covariates. RESULTS A total of 94 participants (32 women) with a median age of 56 (interquartile range 44-66) years were studied. Their median IPFD was 9.6% (interquartile range 8.8-10.4%). In the fasted state, the leptin/ghrelin ratio (β = 0.354; 95% confidence interval 0.044-0.663; p = 0.025, in the most adjusted model) and leptin (β = 0.040; 95% confidence interval 1.003-1.078; p = 0.035, in the most adjusted model) were significantly associated with IPFD. Ghrelin in the fasted state was not significantly associated with IPFD. In the postprandial state, the leptin/ghrelin ratio, leptin, and ghrelin were not significantly associated with IPFD. CONCLUSION Fasting circulating levels of leptin are directly associated with IPFD. Purposely designed mechanistic studies are warranted to determine how high leptin may contribute to excess IPFD.
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Affiliation(s)
- Ngoc N Nguyen
- School of Medicine, University of Auckland, Auckland, New Zealand
| | - Ruma G Singh
- School of Medicine, University of Auckland, Auckland, New Zealand
| | - Maxim S Petrov
- School of Medicine, University of Auckland, Auckland, New Zealand
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19
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Fujikawa T. Central regulation of glucose metabolism in an insulin-dependent and -independent manner. J Neuroendocrinol 2021; 33:e12941. [PMID: 33599044 DOI: 10.1111/jne.12941] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 01/12/2021] [Accepted: 01/13/2021] [Indexed: 12/17/2022]
Abstract
The central nervous system (CNS) contributes significantly to glucose homeostasis. The available evidence indicates that insulin directly acts on the CNS, in particular the hypothalamus, to regulate hepatic glucose production, thereby controlling whole-body glucose metabolism. Additionally, insulin also acts on the brain to regulate food intake and fat metabolism, which may indirectly regulate glucose metabolism. Studies conducted over the last decade have found that the CNS can regulate glucose metabolism in an insulin-independent manner. Enhancement of central leptin signalling reverses hyperglycaemia in insulin-deficient rodents. Here, I review the mechanisms by which central insulin and leptin actions regulate glucose metabolism. Although clinical studies have shown that insulin treatment is currently indispensable for managing diabetes, unravelling the neuronal mechanisms underlying the central regulation of glucose metabolism will pave the way for the design of novel therapeutic drugs for diabetes.
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Affiliation(s)
- Teppei Fujikawa
- Center for Hypothalamic Research, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA
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20
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Pereira S, Cline DL, Glavas MM, Covey SD, Kieffer TJ. Tissue-Specific Effects of Leptin on Glucose and Lipid Metabolism. Endocr Rev 2021; 42:1-28. [PMID: 33150398 PMCID: PMC7846142 DOI: 10.1210/endrev/bnaa027] [Citation(s) in RCA: 62] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Indexed: 12/18/2022]
Abstract
The discovery of leptin was intrinsically associated with its ability to regulate body weight. However, the effects of leptin are more far-reaching and include profound glucose-lowering and anti-lipogenic effects, independent of leptin's regulation of body weight. Regulation of glucose metabolism by leptin is mediated both centrally and via peripheral tissues and is influenced by the activation status of insulin signaling pathways. Ectopic fat accumulation is diminished by both central and peripheral leptin, an effect that is beneficial in obesity-associated disorders. The magnitude of leptin action depends upon the tissue, sex, and context being examined. Peripheral tissues that are of particular relevance include the endocrine pancreas, liver, skeletal muscle, adipose tissues, immune cells, and the cardiovascular system. As a result of its potent metabolic activity, leptin is used to control hyperglycemia in patients with lipodystrophy and is being explored as an adjunct to insulin in patients with type 1 diabetes. To fully understand the role of leptin in physiology and to maximize its therapeutic potential, the mechanisms of leptin action in these tissues needs to be further explored.
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Affiliation(s)
- Sandra Pereira
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, Canada
| | - Daemon L Cline
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, Canada
| | - Maria M Glavas
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, Canada
| | - Scott D Covey
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, Canada
| | - Timothy J Kieffer
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, Canada.,Department of Surgery, University of British Columbia, Vancouver, Canada.,School of Biomedical Engineering, University of British Columbia, Vancouver, Canada
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21
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Cochrane VA, Wu Y, Yang Z, ElSheikh A, Dunford J, Kievit P, Fortin DA, Shyng SL. Leptin modulates pancreatic β-cell membrane potential through Src kinase-mediated phosphorylation of NMDA receptors. J Biol Chem 2020; 295:17281-17297. [PMID: 33037073 PMCID: PMC7863909 DOI: 10.1074/jbc.ra120.015489] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 10/08/2020] [Indexed: 12/23/2022] Open
Abstract
The adipocyte-derived hormone leptin increases trafficking of KATP and Kv2.1 channels to the pancreatic β-cell surface, resulting in membrane hyperpolarization and suppression of insulin secretion. We have previously shown that this effect of leptin is mediated by the NMDA subtype of glutamate receptors (NMDARs). It does so by potentiating NMDAR activity, thus enhancing Ca2+ influx and the ensuing downstream signaling events that drive channel trafficking to the cell surface. However, the molecular mechanism by which leptin potentiates NMDARs in β-cells remains unknown. Here, we report that leptin augments NMDAR function via Src kinase-mediated phosphorylation of the GluN2A subunit. Leptin-induced membrane hyperpolarization diminished upon pharmacological inhibition of GluN2A but not GluN2B, indicating involvement of GluN2A-containing NMDARs. GluN2A harbors tyrosine residues that, when phosphorylated by Src family kinases, potentiate NMDAR activity. We found that leptin increases phosphorylation of Tyr-418 in Src, an indicator of kinase activation. Pharmacological inhibition of Src or overexpression of a kinase-dead Src mutant prevented the effect of leptin, whereas a Src kinase activator peptide mimicked it. Using mutant GluN2A overexpression, we show that Tyr-1292 and Tyr-1387 but not Tyr-1325 are responsible for the effect of leptin. Importantly, β-cells from db/db mice, a type 2 diabetes mouse model lacking functional leptin receptors, or from obese diabetic human donors failed to respond to leptin but hyperpolarized in response to NMDA. Our study reveals a signaling pathway wherein leptin modulates NMDARs via Src to regulate β-cell excitability and suggests NMDARs as a potential target to overcome leptin resistance.
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Affiliation(s)
- Veronica A Cochrane
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, Oregon, USA
| | - Yi Wu
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, Oregon, USA
| | - Zhongying Yang
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, Oregon, USA
| | - Assmaa ElSheikh
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, Oregon, USA; Department of Medical Biochemistry, Tanta University, Tanta, Egypt
| | - Jeremy Dunford
- Department of Integrated Physiology and Neuroscience, College of Arts and Sciences, Washington State University, Vancouver, Washington, USA
| | - Paul Kievit
- Division of Cardiometabolic Health, Oregon National Primate Research Center, Beaverton, Oregon, USA
| | - Dale A Fortin
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, Oregon, USA; Department of Integrated Physiology and Neuroscience, College of Arts and Sciences, Washington State University, Vancouver, Washington, USA.
| | - Show-Ling Shyng
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, Oregon, USA.
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22
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Miranda MA, Carson C, St. Pierre CL, Macias‐Velasco JF, Hughes JW, Kunzmann M, Schmidt H, Wayhart JP, Lawson HA. Spontaneous restoration of functional β-cell mass in obese SM/J mice. Physiol Rep 2020; 8:e14573. [PMID: 33113267 PMCID: PMC7592878 DOI: 10.14814/phy2.14573] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 08/08/2020] [Indexed: 12/23/2022] Open
Abstract
Maintenance of functional β-cell mass is critical to preventing diabetes, but the physiological mechanisms that cause β-cell populations to thrive or fail in the context of obesity are unknown. High fat-fed SM/J mice spontaneously transition from hyperglycemic-obese to normoglycemic-obese with age, providing a unique opportunity to study β-cell adaptation. Here, we characterize insulin homeostasis, islet morphology, and β-cell function during SM/J's diabetic remission. As they resolve hyperglycemia, obese SM/J mice dramatically increase circulating and pancreatic insulin levels while improving insulin sensitivity. Immunostaining of pancreatic sections reveals that obese SM/J mice selectively increase β-cell mass but not α-cell mass. Obese SM/J mice do not show elevated β-cell mitotic index, but rather elevated α-cell mitotic index. Functional assessment of isolated islets reveals that obese SM/J mice increase glucose-stimulated insulin secretion, decrease basal insulin secretion, and increase islet insulin content. These results establish that β-cell mass expansion and improved β-cell function underlie the resolution of hyperglycemia, indicating that obese SM/J mice are a valuable tool for exploring how functional β-cell mass can be recovered in the context of obesity.
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Affiliation(s)
- Mario A. Miranda
- Department of GeneticsWashington University School of MedicineSaint LouisMOUSA
| | - Caryn Carson
- Department of GeneticsWashington University School of MedicineSaint LouisMOUSA
| | | | | | - Jing W. Hughes
- Department of MedicineWashington University School of MedicineSaint LouisMOUSA
| | - Marcus Kunzmann
- Department of GeneticsWashington University School of MedicineSaint LouisMOUSA
| | - Heather Schmidt
- Department of GeneticsWashington University School of MedicineSaint LouisMOUSA
| | - Jessica P. Wayhart
- Department of GeneticsWashington University School of MedicineSaint LouisMOUSA
| | - Heather A. Lawson
- Department of GeneticsWashington University School of MedicineSaint LouisMOUSA
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23
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Singha A, Palavicini JP, Pan M, Farmer S, Sandoval D, Han X, Fujikawa T. Leptin Receptors in RIP-Cre 25Mgn Neurons Mediate Anti-dyslipidemia Effects of Leptin in Insulin-Deficient Mice. Front Endocrinol (Lausanne) 2020; 11:588447. [PMID: 33071988 PMCID: PMC7538546 DOI: 10.3389/fendo.2020.588447] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 08/25/2020] [Indexed: 12/13/2022] Open
Abstract
Leptin is a potent endocrine hormone produced by adipose tissue and regulates a broad range of whole-body metabolism such as glucose and lipid metabolism, even without insulin. Central leptin signaling can lower hyperglycemia in insulin-deficient rodents via multiple mechanisms, including improvements of dyslipidemia. However, the specific neurons that regulate anti-dyslipidemia effects of leptin remain unidentified. Here we report that leptin receptors (LEPRs) in neurons expressing Cre recombinase driven by a short fragment of a promoter region of Ins2 gene (RIP-Cre25Mgn neurons) are required for central leptin signaling to reverse dyslipidemia, thereby hyperglycemia in insulin-deficient mice. Ablation of LEPRs in RIP-Cre25Mgn neurons completely blocks glucose-lowering effects of leptin in insulin-deficient mice. Further investigations reveal that insulin-deficient mice lacking LEPRs in RIP-Cre25Mgn neurons (RIP-CreΔLEPR mice) exhibit greater lipid levels in blood and liver compared to wild-type controls, and that leptin injection into the brain does not suppress dyslipidemia in insulin-deficient RIP-CreΔLEPR mice. Leptin administration into the brain combined with acipimox, which lowers blood lipids by suppressing triglyceride lipase activity, can restore normal glycemia in insulin-deficient RIP-CreΔLEPR mice, suggesting that excess circulating lipids are a driving-force of hyperglycemia in these mice. Collectively, our data demonstrate that LEPRs in RIP-Cre25Mgn neurons significantly contribute to glucose-lowering effects of leptin in an insulin-independent manner by improving dyslipidemia.
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Affiliation(s)
- Ashish Singha
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, San Antonio, TX, United States
| | - Juan Pablo Palavicini
- Barshop Institute for Longevity and Aging Studies, University of Texas Health San Antonio, San Antonio, TX, United States
| | - Meixia Pan
- Barshop Institute for Longevity and Aging Studies, University of Texas Health San Antonio, San Antonio, TX, United States
| | - Scotlynn Farmer
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, San Antonio, TX, United States
| | - Darleen Sandoval
- Department of Surgery, University of Michigan, Ann Arbor, MI, United States
| | - Xianlin Han
- Barshop Institute for Longevity and Aging Studies, University of Texas Health San Antonio, San Antonio, TX, United States
| | - Teppei Fujikawa
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, San Antonio, TX, United States
- Center for Biomedical Neuroscience, University of Texas Health San Antonio, San Antonio, TX, United States
- Division of Hypothalamic Research Center, Internal Medicine, UT Southwestern Medical Center at Dallas, Dallas, TX, United States
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24
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Le B, Cheng X, Qu S. Cooperative effects of galanin and leptin on alleviation of insulin resistance in adipose tissue of diabetic rats. J Cell Mol Med 2020; 24:6773-6780. [PMID: 32395890 PMCID: PMC7299679 DOI: 10.1111/jcmm.15328] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Revised: 02/29/2020] [Accepted: 03/31/2020] [Indexed: 12/13/2022] Open
Abstract
It was reported that either orexigenic neuropeptide galanin or anorexigenic hormone leptin caught benefit insulin sensitivity through increasing the translocation of glucose transporter 4 (GLUT4) in patients with diabetes. To date, it is unknown whether galanin can potentiate the effect of leptin on alleviation of insulin resistance. Therefore, in the current study we sought to assess the combined effect of central leptin and galanin on insulin resistance in the adipose tissues of type 2 diabetic rats. Galanin and leptin were injected into the intracerebroventricle of the diabetic rats, respectively, or cooperatively once a day for 2 weeks. Then, several indexes of insulin resistance were examined. The results showed that glucose infusion rates in the hyperinsulinaemic-euglycaemic clamp test, plasma adiponectin content and GLUT4 translocation, as well as Akt phosphorylation in fat cells, were higher, not GLUT4 protein and GLUT4 mRNA expression, but HOMA index was lower in the galanin + leptin group than either one of them. Furthermore, treatment with MK-2206, an Akt inhibitor, blocked the combined effects of galanin + leptin on alleviation of insulin resistance. These results suggest that galanin can improve the leptin-induced mitigative effects on insulin resistance in the fat cells, and those provided new insights into the potential tactics for prevention and remedy of insulin resistance.
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Affiliation(s)
- Bu Le
- Department of EndocrinologyShanghai 10th People HospitalTongji University School of MedicineShanghaiChina
| | - Xiaoyun Cheng
- Department of EndocrinologyShanghai 10th People HospitalTongji University School of MedicineShanghaiChina
| | - Shen Qu
- Department of EndocrinologyShanghai 10th People HospitalTongji University School of MedicineShanghaiChina
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Adipokines as key players in β cell function and failure. Clin Sci (Lond) 2020; 133:2317-2327. [PMID: 31769478 DOI: 10.1042/cs20190523] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 11/11/2019] [Accepted: 11/13/2019] [Indexed: 12/13/2022]
Abstract
The growing prevalence of obesity and its related metabolic diseases, mainly Type 2 diabetes (T2D), has increased the interest in adipose tissue (AT) and its role as a principal metabolic orchestrator. Two decades of research have now shown that ATs act as an endocrine organ, secreting soluble factors termed adipocytokines or adipokines. These adipokines play crucial roles in whole-body metabolism with different mechanisms of action largely dependent on the tissue or cell type they are acting on. The pancreatic β cell, a key regulator of glucose metabolism due to its ability to produce and secrete insulin, has been identified as a target for several adipokines. This review will focus on how adipokines affect pancreatic β cell function and their impact on pancreatic β cell survival in disease contexts such as diabetes. Initially, the "classic" adipokines will be discussed, followed by novel secreted adipocyte-specific factors that show therapeutic promise in regulating the adipose-pancreatic β cell axis.
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Commentary on Camell et al., Aging Induces Nlrp3 Inflammasome Dependent Adipose B Cell Expansion to Impair Metabolic Homeostasis. ACTA ACUST UNITED AC 2020; 2. [PMID: 32292596 PMCID: PMC7156147 DOI: 10.20900/immunometab20200011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The burden of aging and obesity is urging extended investigation into the molecular mechanisms that underlie chronic adipose tissue inflammation. B cell-targeted therapies are emerging as novel tools to modulate the immune system and thereby mitigate aging and obesity-related metabolic complications.
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Al-Suhaimi EA, Al-Jafary MA. Endocrine roles of vitamin K-dependent- osteocalcin in the relation between bone metabolism and metabolic disorders. Rev Endocr Metab Disord 2020; 21:117-125. [PMID: 31761961 DOI: 10.1007/s11154-019-09517-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Obesity and diabetes are important metabolic diseases and a major public health problem among the world, they have serious health and economic complications. Overweight and obesity are increased risk for deficiency of vitamin particularly shortage of fat soluble-vitamins. Studies reported that vitamin K supplementation reduces oxidative stress and metabolic risk biomarkers for diabetes, as well as reduces progression of insulin resistance. Vitamin K-dependent-protein osteocalcin (bone derived hormone) plays crucial roles in energy metabolism. There is a clear association between circulating vitamin k and dependent-osteocalcin concentrations with obesity and risk of Type 2 diabetes. Osteocalcin through molecular mechanisms improves insulin resistance, lipid and glucose profile, and mediate vitamin K positive effects. Insulin also signals osteocalcin to regulate bone mineralization. Normal carboxylation of vitamin K-dependent proteins/ hormones is a key step in preventing apoptosis and calcification of vascular endothelial cells. A missing relationship between bone, glucose and fat metabolism could clarify and manage many metabolic mechanisms. This review focuses on the physiological relationship between vitamin K-dependent-osteocalcin, metabolic and cardiovascular diseases through some molecular proteins and hormones including adipokines. A better understanding of the mechanism of action of osteocalcin modulated by vitamin K could help in implementing therapeutic drugs to cure metabolic diseases.
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Affiliation(s)
- Ebtesam Abdullah Al-Suhaimi
- Department of Biology, College of Science, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia.
- Institute for Research and Medical Consultations (IRMC), Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia.
| | - Meneerah Abdulrahman Al-Jafary
- Department of Biology, College of Science, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
- Institute for Research and Medical Consultations (IRMC), Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
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Teixeira PDS, Couto GC, Furigo IC, List EO, Kopchick JJ, Donato J. Central growth hormone action regulates metabolism during pregnancy. Am J Physiol Endocrinol Metab 2019; 317:E925-E940. [PMID: 31479305 PMCID: PMC7132326 DOI: 10.1152/ajpendo.00229.2019] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The maternal organism undergoes numerous metabolic adaptations to become prepared for the demands associated with the coming offspring. These metabolic adaptations involve changes induced by several hormones that act at multiple levels, ultimately influencing energy and glucose homeostasis during pregnancy and lactation. Previous studies have shown that central growth hormone (GH) action modulates glucose and energy homeostasis. However, whether central GH action regulates metabolism during pregnancy and lactation is still unknown. In the present study, we generated mice carrying ablation of GH receptor (GHR) in agouti-related protein (AgRP)-expressing neurons, in leptin receptor (LepR)-expressing cells or in the entire brain to investigate the role played by central GH action during pregnancy and lactation. AgRP-specific GHR ablation led to minor metabolic changes during pregnancy and lactation. However, while brain-specific GHR ablation reduced food intake and body adiposity during gestation, LepR GHR knockout (KO) mice exhibited increased leptin responsiveness in the ventromedial nucleus of the hypothalamus during late pregnancy, although their offspring showed reduced growth rate. Additionally, both Brain GHR KO and LepR GHR KO mice had lower glucose tolerance and glucose-stimulated insulin secretion during pregnancy, despite presenting increased insulin sensitivity, compared with control pregnant animals. Our findings revealed that during pregnancy central GH action regulates food intake, fat retention, as well as the sensitivity to insulin and leptin in a cell-specific manner. Together, the results suggest that GH acts in concert with other "gestational hormones" to prepare the maternal organism for the metabolic demands of the offspring.
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Affiliation(s)
- Pryscila D S Teixeira
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Gisele C Couto
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Isadora C Furigo
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Edward O List
- Edison Biotechnology Institute and Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio
| | - John J Kopchick
- Edison Biotechnology Institute and Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio
| | - Jose Donato
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
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Singh RG, Nguyen NN, Cervantes A, Alarcon Ramos GC, Cho J, Petrov MS. Associations between intra-pancreatic fat deposition and circulating levels of cytokines. Cytokine 2019; 120:107-114. [DOI: 10.1016/j.cyto.2019.04.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 03/29/2019] [Accepted: 04/18/2019] [Indexed: 12/12/2022]
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30
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Powe CE, Huston Presley LP, Locascio JJ, Catalano PM. Augmented insulin secretory response in early pregnancy. Diabetologia 2019; 62:1445-1452. [PMID: 31177313 PMCID: PMC6786902 DOI: 10.1007/s00125-019-4881-6] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 03/18/2019] [Indexed: 01/15/2023]
Abstract
AIMS/HYPOTHESIS This study aimed to examine changes in the insulin secretory response in early pregnancy, while accounting for changes in insulin sensitivity. METHODS This is a secondary analysis of a previously conducted longitudinal physiological study. In 34 women, insulin secretory response (by IVGTT) and insulin sensitivity (by euglycaemic clamp) were assessed prior to pregnancy, in early pregnancy (12-14 weeks gestation) and in late pregnancy (34-36 weeks gestation). Using mixed-effects models, we compared insulin secretory response and sensitivity in early pregnancy to the same variables prior to pregnancy and in late pregnancy, with adjustment for age, obesity status and gestational diabetes mellitus (GDM). We examined changes in insulin secretory response after adjustment for insulin sensitivity using both multivariate modelling and the disposition index (DI). We explored the relationship between insulin secretory response and circulating hormones. RESULTS The insulin secretory response increased from prior to pregnancy to early pregnancy (unadjusted mean [SD] first-phase insulin response 465.1 [268.5] to 720 [358.2], p < 0.0001) and from early pregnancy to late pregnancy (to 924 [494.6], p = 0.01). Insulin sensitivity increased from prior to pregnancy to early pregnancy (insulin sensitivity index 0.10 [0.04] to 0.12 [0.05], p = 0.001) and decreased in late pregnancy (to 0.06 [0.03], p < 0.0001). Accounting for changes in insulin sensitivity, using either multivariate modelling or the DI, did not attenuate the early-pregnancy augmentation of insulin secretory response. Leptin was positively associated with insulin secretory response, independent of insulin sensitivity and adiposity (p = 0.004). Adjustment for leptin attenuated the observed augmentation of insulin secretory response in early pregnancy (adjusted mean change 121.5, p = 0.13). CONCLUSIONS/INTERPRETATION The insulin secretory response increases markedly in early pregnancy, prior to and independent of changes in insulin sensitivity. Circulating hormones may mediate this metabolic adaptation. Identifying mediators of this physiological effect could have therapeutic implications for treating hyperglycaemia during and outside of pregnancy.
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Affiliation(s)
- Camille E Powe
- Diabetes Unit, Endocrine Division, Massachusetts General Hospital, 50 Staniford Street, Suite 301, Boston, MA, 02114, USA.
- Harvard Medical School, Boston, MA, USA.
| | - Larraine P Huston Presley
- Department of Reproductive Biology, Case Western Reserve University, MetroHealth Medical Center, Cleveland, OH, USA
| | - Joseph J Locascio
- Alzheimer's Disease Research Center, Neurology Dept, Massachusetts General Hospital, Boston, MA, USA
| | - Patrick M Catalano
- Mother Infant Research Institute, Department of Obstetrics and Gynecology, Tufts University School of Medicine, Boston, MA, USA
- Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA, USA
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31
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Leptin-induced Trafficking of K ATP Channels: A Mechanism to Regulate Pancreatic β-cell Excitability and Insulin Secretion. Int J Mol Sci 2019; 20:ijms20112660. [PMID: 31151172 PMCID: PMC6600549 DOI: 10.3390/ijms20112660] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Revised: 05/25/2019] [Accepted: 05/27/2019] [Indexed: 11/17/2022] Open
Abstract
The adipocyte hormone leptin was first recognized for its actions in the central nervous system to regulate energy homeostasis but has since been shown to have direct actions on peripheral tissues. In pancreatic β-cells leptin suppresses insulin secretion by increasing KATP channel conductance, which causes membrane hyperpolarization and renders β-cells electrically silent. However, the mechanism by which leptin increases KATP channel conductance had remained unresolved for many years following the initial observation. Recent studies have revealed that leptin increases surface abundance of KATP channels by promoting channel trafficking to the β-cell membrane. Thus, KATP channel trafficking regulation has emerged as a mechanism by which leptin increases KATP channel conductance to regulate β-cell electrical activity and insulin secretion. This review will discuss the leptin signaling pathway that underlies KATP channel trafficking regulation in β-cells.
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32
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Douros JD, Niu J, Sdao S, Gregg T, Fisher-Wellman K, Bharadwaj M, Molina A, Arumugam R, Martin M, Petretto E, Merrins MJ, Herman MA, Tong J, Campbell J, D’Alessio D. Sleeve gastrectomy rapidly enhances islet function independently of body weight. JCI Insight 2019; 4:126688. [PMID: 30777938 PMCID: PMC6483064 DOI: 10.1172/jci.insight.126688] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 02/11/2019] [Indexed: 12/14/2022] Open
Abstract
Bariatric surgeries including vertical sleeve gastrectomy (VSG) ameliorate obesity and diabetes. Weight loss and accompanying increases to insulin sensitivity contribute to improved glycemia after surgery; however, studies in humans also suggest weight-independent actions of bariatric procedures to lower blood glucose, possibly by improving insulin secretion. To evaluate this hypothesis, we compared VSG-operated mice with pair-fed, sham-surgical controls (PF-Sham) 2 weeks after surgery. This paradigm yielded similar postoperative body weight and insulin sensitivity between VSG and calorically restricted PF-Sham animals. However, VSG improved glucose tolerance and markedly enhanced insulin secretion during oral nutrient and i.p. glucose challenges compared with controls. Islets from VSG mice displayed a unique transcriptional signature enriched for genes involved in Ca2+ signaling and insulin secretion pathways. This finding suggests that bariatric surgery leads to intrinsic changes within the islet that alter function. Indeed, islets isolated from VSG mice had increased glucose-stimulated insulin secretion and a left-shifted glucose sensitivity curve compared with islets from PF-Sham mice. Isolated islets from VSG animals showed corresponding increases in the pulse duration of glucose-stimulated Ca2+ oscillations. Together, these findings demonstrate a weight-independent improvement in glycemic control following VSG, which is, in part, driven by improved insulin secretion and associated with substantial changes in islet gene expression. These results support a model in which β cells play a key role in the adaptation to bariatric surgery and the improved glucose tolerance that is typical of these procedures.
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Affiliation(s)
- Jonathan D. Douros
- Division of Endocrinology, Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, USA
| | - Jingjing Niu
- Division of Endocrinology, Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, USA
| | - Sophia Sdao
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Trillian Gregg
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Kelsey Fisher-Wellman
- Division of Endocrinology, Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, USA
| | - Manish Bharadwaj
- Center for Diabetes Research, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Anthony Molina
- Center for Diabetes Research, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Ramamani Arumugam
- Division of Endocrinology, Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, USA
| | - MacKenzie Martin
- Division of Endocrinology, Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, USA
| | - Enrico Petretto
- Centre for Computational Biology, Duke-NUS Medical School, Singapore
| | - Matthew J. Merrins
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Mark A. Herman
- Division of Endocrinology, Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, USA
| | - Jenny Tong
- Division of Endocrinology, Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, USA
| | - Jonathan Campbell
- Division of Endocrinology, Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, USA
| | - David D’Alessio
- Division of Endocrinology, Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, USA
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Waldman M, Cohen K, Yadin D, Nudelman V, Gorfil D, Laniado-Schwartzman M, Kornwoski R, Aravot D, Abraham NG, Arad M, Hochhauser E. Regulation of diabetic cardiomyopathy by caloric restriction is mediated by intracellular signaling pathways involving 'SIRT1 and PGC-1α'. Cardiovasc Diabetol 2018; 17:111. [PMID: 30071860 PMCID: PMC6090985 DOI: 10.1186/s12933-018-0754-4] [Citation(s) in RCA: 124] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 07/26/2018] [Indexed: 12/25/2022] Open
Abstract
Background Metabolic disorders such as obesity, insulin resistance and type 2 diabetes mellitus (DM2) are all linked to diabetic cardiomyopathy that lead to heart failure. Cardiomyopathy is initially characterized by cardiomyocyte hypertrophy, followed by mitochondrial dysfunction and fibrosis, both of which are aggravated by angiotensin. Caloric restriction (CR) is cardioprotective in animal models of heart disease through its catabolic activity and activation of the expression of adaptive genes. We hypothesized that in the diabetic heart; this effect involves antioxidant defenses and is mediated by SIRT1 and the transcriptional coactivator PGC-1α (Peroxisome proliferator-activated receptor-γ coactivator). Methods Obese Leptin resistant (db/db) mice characterized by DM2 were treated with angiotensin II (AT) for 4 weeks to enhance the development of cardiomyopathy. Mice were concomitantly either on a CR diet or fed ad libitum. Cardiomyocytes were exposed to high levels of glucose and were treated with EX-527 (SIRT1 inhibitor). Cardiac structure and function, gene and protein expression and oxidative stress parameters were analyzed. Results AT treated db/db mice developed cardiomyopathy manifested by elevated levels of serum glucose, cholesterol and cardiac hypertrophy. Leukocyte infiltration, fibrosis and an increase in an inflammatory marker (TNFα) and natriuretic peptides (ANP, BNP) gene expression were also observed. Oxidative stress was manifested by low SOD and PGC-1α levels and an increase in ROS and MDA. DM2 resulted in ERK1/2 activation. CR attenuated all these deleterious perturbations and prevented the development of cardiomyopathy. ERK1/2 phosphorylation was reduced in CR mice (p = 0.008). Concomitantly CR prevented the reduction in SIRT activity and PGC-1α (p < 0.04). Inhibition of SIRT1 activity in cardiomyocytes led to a marked reduction in both SIRT1 and PGC-1α. ROS levels were significantly (p < 0.03) increased by glucose and SIRT1 inhibition. Conclusion In the current study we present evidence of the cardioprotective effects of CR operating through SIRT1 and PGC-1 α, thereby decreasing oxidative stress, fibrosis and inflammation. Our results suggest that increasing SIRT1 and PGC-1α levels offer new therapeutic approaches for the protection of the diabetic heart.
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Affiliation(s)
- Maayan Waldman
- Cardiac Research Laboratory, Felsenstein Medical Research Institute Petah-Tikva, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.,Leviev Heart Center, Sheba Medical Center, Tel Hashomer and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Keren Cohen
- Cardiac Research Laboratory, Felsenstein Medical Research Institute Petah-Tikva, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.,Leviev Heart Center, Sheba Medical Center, Tel Hashomer and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Dor Yadin
- Cardiac Research Laboratory, Felsenstein Medical Research Institute Petah-Tikva, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.,Leviev Heart Center, Sheba Medical Center, Tel Hashomer and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Vadim Nudelman
- Cardiac Research Laboratory, Felsenstein Medical Research Institute Petah-Tikva, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Dan Gorfil
- Cardiac Research Laboratory, Felsenstein Medical Research Institute Petah-Tikva, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | | | - Ran Kornwoski
- Cardiac Research Laboratory, Felsenstein Medical Research Institute Petah-Tikva, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Dan Aravot
- Cardiac Research Laboratory, Felsenstein Medical Research Institute Petah-Tikva, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Nader G Abraham
- Department of Pharmacology, New York Medical College, Valhalla, NY, 10595, USA
| | - Michael Arad
- Leviev Heart Center, Sheba Medical Center, Tel Hashomer and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Edith Hochhauser
- Cardiac Research Laboratory, Felsenstein Medical Research Institute Petah-Tikva, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel. .,Felsenstein Research Center, Rabin Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Jabotinsky St, 49100, Petach Tikva, Israel.
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Wang B, Li A, Li X, Ho PW, Wu D, Wang X, Liu Z, Wu KK, Yau SS, Xu A, Cheng KK. Activation of hypothalamic RIP-Cre neurons promotes beiging of WAT via sympathetic nervous system. EMBO Rep 2018; 19:embr.201744977. [PMID: 29467283 DOI: 10.15252/embr.201744977] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 01/23/2018] [Accepted: 01/25/2018] [Indexed: 01/11/2023] Open
Abstract
Activation of brown adipose tissue (BAT) and beige fat by cold increases energy expenditure. Although their activation is known to be differentially regulated in part by hypothalamus, the underlying neural pathways and populations remain poorly characterized. Here, we show that activation of rat-insulin-promoter-Cre (RIP-Cre) neurons in ventromedial hypothalamus (VMH) preferentially promotes recruitment of beige fat via a selective control of sympathetic nervous system (SNS) outflow to subcutaneous white adipose tissue (sWAT), but has no effect on BAT Genetic ablation of APPL2 in RIP-Cre neurons diminishes beiging in sWAT without affecting BAT, leading to cold intolerance and obesity in mice. Such defects are reversed by activation of RIP-Cre neurons, inactivation of VMH AMPK, or treatment with a β3-adrenergic receptor agonist. Hypothalamic APPL2 enhances neuronal activation in VMH RIP-Cre neurons and raphe pallidus, thereby eliciting SNS outflow to sWAT and subsequent beiging. These data suggest that beige fat can be selectively activated by VMH RIP-Cre neurons, in which the APPL2-AMPK signaling axis is crucial for this defending mechanism to cold and obesity.
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Affiliation(s)
- Baile Wang
- State Key Laboratory of Pharmaceutical Biotechnology, The University of Hong Kong, Hong Kong, China.,Department of Medicine, The University of Hong Kong, Hong Kong, China
| | - Ang Li
- Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Joint International Research Laboratory of CNS Regeneration Ministry of Education, Guangdong Medical Key Laboratory of Brain Function and Diseases, Jinan University, Guangzhou, China
| | - Xiaomu Li
- Department of Endocrinology and Metabolism, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Philip Wl Ho
- Department of Medicine, The University of Hong Kong, Hong Kong, China
| | - Donghai Wu
- Key Laboratory of Regenerative Biology and Guangdong Provincial, Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Xiaoqi Wang
- Department of Surgery, The University of Hong Kong, Hong Kong, China
| | - Zhuohao Liu
- State Key Laboratory of Pharmaceutical Biotechnology, The University of Hong Kong, Hong Kong, China.,Department of Medicine, The University of Hong Kong, Hong Kong, China
| | - Kelvin Kl Wu
- Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hong Kong, China
| | - Sonata Sy Yau
- Department of Rehabilitation Science, The Hong Kong Polytechnic University, Hong Kong, China
| | - Aimin Xu
- State Key Laboratory of Pharmaceutical Biotechnology, The University of Hong Kong, Hong Kong, China .,Department of Medicine, The University of Hong Kong, Hong Kong, China.,Department of Pharmacology & Pharmacy, The University of Hong Kong, Hong Kong, China
| | - Kenneth Ky Cheng
- Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hong Kong, China
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35
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Burchfield JG, Kebede MA, Meoli CC, Stöckli J, Whitworth PT, Wright AL, Hoffman NJ, Minard AY, Ma X, Krycer JR, Nelson ME, Tan SX, Yau B, Thomas KC, Wee NKY, Khor EC, Enriquez RF, Vissel B, Biden TJ, Baldock PA, Hoehn KL, Cantley J, Cooney GJ, James DE, Fazakerley DJ. High dietary fat and sucrose results in an extensive and time-dependent deterioration in health of multiple physiological systems in mice. J Biol Chem 2018; 293:5731-5745. [PMID: 29440390 DOI: 10.1074/jbc.ra117.000808] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 02/12/2018] [Indexed: 01/17/2023] Open
Abstract
Obesity is associated with metabolic dysfunction, including insulin resistance and hyperinsulinemia, and with disorders such as cardiovascular disease, osteoporosis, and neurodegeneration. Typically, these pathologies are examined in discrete model systems and with limited temporal resolution, and whether these disorders co-occur is therefore unclear. To address this question, here we examined multiple physiological systems in male C57BL/6J mice following prolonged exposure to a high-fat/high-sucrose diet (HFHSD). HFHSD-fed mice rapidly exhibited metabolic alterations, including obesity, hyperleptinemia, physical inactivity, glucose intolerance, peripheral insulin resistance, fasting hyperglycemia, ectopic lipid deposition, and bone deterioration. Prolonged exposure to HFHSD resulted in morbid obesity, ectopic triglyceride deposition in liver and muscle, extensive bone loss, sarcopenia, hyperinsulinemia, and impaired short-term memory. Although many of these defects are typically associated with aging, HFHSD did not alter telomere length in white blood cells, indicating that this diet did not generally promote all aspects of aging. Strikingly, glucose homeostasis was highly dynamic. Glucose intolerance was evident in HFHSD-fed mice after 1 week and was maintained for 24 weeks. Beyond 24 weeks, however, glucose tolerance improved in HFHSD-fed mice, and by 60 weeks, it was indistinguishable from that of chow-fed mice. This improvement coincided with adaptive β-cell hyperplasia and hyperinsulinemia, without changes in insulin sensitivity in muscle or adipose tissue. Assessment of insulin secretion in isolated islets revealed that leptin, which inhibited insulin secretion in the chow-fed mice, potentiated glucose-stimulated insulin secretion in the HFHSD-fed mice after 60 weeks. Overall, the excessive calorie intake was accompanied by deteriorating function of numerous physiological systems.
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Affiliation(s)
- James G Burchfield
- From the Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales 2006, Australia.,Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
| | - Melkam A Kebede
- From the Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales 2006, Australia
| | - Christopher C Meoli
- From the Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales 2006, Australia.,Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
| | - Jacqueline Stöckli
- From the Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales 2006, Australia.,Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
| | - P Tess Whitworth
- Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
| | - Amanda L Wright
- Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
| | - Nolan J Hoffman
- From the Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales 2006, Australia.,Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
| | - Annabel Y Minard
- From the Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales 2006, Australia.,Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
| | - Xiuquan Ma
- Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
| | - James R Krycer
- From the Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales 2006, Australia.,Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
| | - Marin E Nelson
- From the Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales 2006, Australia
| | - Shi-Xiong Tan
- Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
| | - Belinda Yau
- From the Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales 2006, Australia
| | - Kristen C Thomas
- From the Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales 2006, Australia.,Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
| | - Natalie K Y Wee
- Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
| | - Ee-Cheng Khor
- Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
| | - Ronaldo F Enriquez
- Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
| | - Bryce Vissel
- Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
| | - Trevor J Biden
- Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
| | - Paul A Baldock
- Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
| | - Kyle L Hoehn
- Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
| | - James Cantley
- Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
| | - Gregory J Cooney
- From the Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales 2006, Australia.,Charles Perkins Centre, Sydney Medical School, University of Sydney, Camperdown, New South Wales 2006, Australia
| | - David E James
- From the Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales 2006, Australia, .,Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and.,Charles Perkins Centre, Sydney Medical School, University of Sydney, Camperdown, New South Wales 2006, Australia
| | - Daniel J Fazakerley
- From the Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales 2006, Australia.,Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
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Auclair N, Melbouci L, St-Pierre D, Levy E. Gastrointestinal factors regulating lipid droplet formation in the intestine. Exp Cell Res 2018; 363:1-14. [PMID: 29305172 DOI: 10.1016/j.yexcr.2017.12.031] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 12/28/2017] [Accepted: 12/29/2017] [Indexed: 12/22/2022]
Abstract
Cytoplasmic lipid droplets (CLD) are considered as neutral lipid reservoirs, which protect cells from lipotoxicity. It became clear that these fascinating dynamic organelles play a role not only in energy storage and metabolism, but also in cellular lipid and protein handling, inter-organelle communication, and signaling among diverse functions. Their dysregulation is associated with multiple disorders, including obesity, liver steatosis and cardiovascular diseases. The central aim of this review is to highlight the link between intra-enterocyte CLD dynamics and the formation of chylomicrons, the main intestinal dietary lipid vehicle, after overviewing the morphology, molecular composition, biogenesis and functions of CLD.
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Affiliation(s)
- N Auclair
- Research Centre, CHU Sainte-Justine and Department of Montreal, Quebec, Canada H3T 1C5; Nutrition, Université de Montréal, Montreal, Quebec, Canada H3T 1C5
| | - L Melbouci
- Research Centre, CHU Sainte-Justine and Department of Montreal, Quebec, Canada H3T 1C5; Department of Sciences and Physical Activities, UQAM, Quebec, Canada H2X 1Y4
| | - D St-Pierre
- Research Centre, CHU Sainte-Justine and Department of Montreal, Quebec, Canada H3T 1C5; Department of Sciences and Physical Activities, UQAM, Quebec, Canada H2X 1Y4
| | - E Levy
- Research Centre, CHU Sainte-Justine and Department of Montreal, Quebec, Canada H3T 1C5; Nutrition, Université de Montréal, Montreal, Quebec, Canada H3T 1C5; Institute of Nutrition and Functional Foods (INAF), Université Laval, Quebec, Quebec, Canada G1V 0A6.
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Abstract
Leptin is an adipocyte-derived hormone, which contributes to the homeostatic regulation of energy balance and metabolism through humoral and neural pathways. Leptin acts on the neurons in certain brain areas such as the hypothalamus, hippocampus, and brain stem to regulate food intake, thermogenesis, energy expenditure, and homeostasis of glucose/lipid metabolism. The pathologically increased circulating leptin is a biomarker of leptin resistance, which is common in obese individuals. Leptin resistance is defined by a reduced sensitivity or a failure in response of the brain to leptin, showing a decrease in the ability of leptin to suppress appetite or enhance energy expenditure, which causes an increased food intake and finally leads to overweight, obesity, cardiovascular diseases, and other metabolic disorders. Leptin resistance is a challenge for clinical treatment or drug discovery of obesity. Until recently, emerging evidence has been showing novel mechanisms of the leptin resistance. Here, we summarized the advances and controversy of leptin resistance and associated diseases, for better understanding the physiology and pathophysiology of leptin as well as the new strategies for treating obesity and metabolic disorders.
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Ladyman SR, MacLeod MA, Khant Aung Z, Knowles P, Phillipps HR, Brown RSE, Grattan DR. Prolactin receptors in Rip-cre cells, but not in AgRP neurones, are involved in energy homeostasis. J Neuroendocrinol 2017; 29. [PMID: 28378505 DOI: 10.1111/jne.12474] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Revised: 03/26/2017] [Accepted: 03/30/2017] [Indexed: 12/12/2022]
Abstract
Among its many functions, prolactin has been implicated in energy homeostasis, particularly during pregnancy and lactation. The arcuate nucleus is a key site in the regulation of energy balance. The present study aimed to examine whether arcuate nucleus neuronal populations involved in energy homeostasis are prolactin responsive and whether they can mediate the effects of prolactin on energy homeostasis. To determine whether Agrp neurones or Rip-Cre neurones are prolactin responsive, transgenic mice expressing the reporter td-tomato in Agrp neurones (td-tomato/Agrp-Cre) or Rip-Cre neurones (td-tomato/Rip-Cre) were treated with prolactin and perfused 45 minutes later. Brains were processed for double-labelled immunohistochemistry for pSTAT5, a marker of prolactin-induced intracellular signalling, and td-tomato. In addition, Agrp-Cre mice and Rip-Cre mice were crossed with mice in which the prolactin receptor gene (Prlr) was flanked with LoxP sites (Prlrlox/lox mice). The Prlrlox/lox construct was designed such that Cre-mediated recombination resulted in deletion of the Prlr and expression of green fluorescent protein (GFP) in its place. In td-tomato/Rip-Cre mice, prolactin-induced pSTAT5 was co-localised with td-tomato, indicating that there is a subpopulation of Rip-Cre neurones in the arcuate nucleus that respond to prolactin. Furthermore, mice with a specific deletion of Prlr in Rip-Cre neurones had lower body weights, increased oxygen consumption, increased running wheel activity and numerous cells in the arcuate nucleus had positive GFP staining indicating deletion of Prlr from Rip-Cre neurones. By contrast, no co-localisation of td-tomato and pSTAT5 was observed in td-tomato/Agrp-Cre mice after prolactin treatment. Moreover, Prlrlox/lox /Agrp-Cre mice had no positive GFP staining in the arcuate nucleus and did not differ in body weight compared to littermate controls. Overall, these results indicate that Rip-Cre neurones in the arcuate nucleus are responsive to prolactin and may play a role in the orexigenic effects of prolactin, whereas prolactin does not directly affect Agrp neurones.
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Affiliation(s)
- S R Ladyman
- Department of Anatomy, Centre for Neuroendocrinology, University of Otago, Dunedin, New Zealand
| | - M A MacLeod
- Department of Anatomy, Centre for Neuroendocrinology, University of Otago, Dunedin, New Zealand
| | - Z Khant Aung
- Department of Anatomy, Centre for Neuroendocrinology, University of Otago, Dunedin, New Zealand
| | - P Knowles
- Department of Anatomy, Centre for Neuroendocrinology, University of Otago, Dunedin, New Zealand
| | - H R Phillipps
- Department of Anatomy, Centre for Neuroendocrinology, University of Otago, Dunedin, New Zealand
| | - R S E Brown
- Department of Anatomy, Centre for Neuroendocrinology, University of Otago, Dunedin, New Zealand
| | - D R Grattan
- Department of Anatomy, Centre for Neuroendocrinology, University of Otago, Dunedin, New Zealand
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Mondal P, Prasad A, Girdhar K. Interventions to improve β-cell mass and function. ANNALES D'ENDOCRINOLOGIE 2017; 78:469-477. [PMID: 28870707 DOI: 10.1016/j.ando.2016.11.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 10/18/2016] [Accepted: 11/09/2016] [Indexed: 01/09/2023]
Abstract
Diabetes mellitus (T2DM) has become an epidemiologically important disease worldwide and is also becoming a great matter of concern due to the effects associated with it like: high morbidity, elevated health care cost and shortened life span. T2DM is a chronic metabolic disease characterized by insulin resistance as well as β-cell dysfunction. It is widely accepted that in the face of insulin resistance, euglycemia can be maintained by increase in pancreatic β-cell mass and insulin secretion. This compensation is largely due to enhanced secretion of insulin by the β-cell mass, which is present initially, and thereby subsequent increases in β-cell mass provide additional insulin secretion. However, the mechanism by which β-cell anatomical plasticity and functional plasticity for insulin secretion is coordinated and executed in different physiological and pathophysiological states is complex and has been poorly understood. As the incidence of T2DM continues to increase at an alarming rate, it is becoming imperative to shift the research focus towards the β-cell physiology where identification of novel pathways that influence the β-cell proliferation and/or contribute to increase insulin secretion has the potential to lead to new therapies for preventing or delaying onset of disease.
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Affiliation(s)
- Prosenjit Mondal
- School of Basic Sciences, BioX, Indian Institute of Technology, Mandi, HP 175005, India.
| | - Amit Prasad
- School of Basic Sciences, BioX, Indian Institute of Technology, Mandi, HP 175005, India
| | - Khyati Girdhar
- School of Basic Sciences, BioX, Indian Institute of Technology, Mandi, HP 175005, India
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40
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Impact of risperidone on leptin and insulin in children and adolescents with autistic spectrum disorders. Clin Biochem 2017; 50:678-685. [DOI: 10.1016/j.clinbiochem.2017.02.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2016] [Revised: 01/12/2017] [Accepted: 02/02/2017] [Indexed: 01/09/2023]
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Tajima K, Shirakawa J, Togashi Y, Yamazaki S, Okuyama T, Kyohara M, Konishi H, Terauchi Y. Metabolic recovery of lipodystrophy, liver steatosis, and pancreatic β cell proliferation after the withdrawal of OSI-906. Sci Rep 2017. [PMID: 28646158 PMCID: PMC5482874 DOI: 10.1038/s41598-017-04304-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Growth factor signaling via insulin receptor (IR) and IGF-1 receptor (IGF1R) plays several important roles in the pathogenesis of metabolic syndrome and diabetes. OSI-906 (linsitinib), an anti-tumor drug, is an orally bioavailable dual inhibitor of IR and IGF1R. To investigate the recovery from metabolic changes induced by the acute inhibition of IR and IGF1R in adult mice, mice were treated with OSI-906 or a vehicle for 7 days and the results were analyzed on the last day of injection (Day 7) or after 7 or 21 days of withdrawal (Day 14 or Day 28). On day 7, the visceral white fat mass was significantly reduced in mice treated with OSI-906 accompanied by a reduced expression of leptin and an increased expression of the lipolysis-related genes Lpl and Atgl. Interestingly, the lipoatrophy and the observed changes in gene expression were completely reversed on day 14. Similarly, liver steatosis and β cell proliferation were transiently observed on day 7 but had disappeared by day 14. Taken together, these results suggest that this model for the acute inhibition of systemic IR/IGF1R signaling may be useful for investigating the recovery from metabolic disorders induced by impaired growth factor signaling.
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Affiliation(s)
- Kazuki Tajima
- Department of Endocrinology and Metabolism, Graduate School of Medicine, Yokohama-City University, Yokohama, Japan, 236-0004, Japan
| | - Jun Shirakawa
- Department of Endocrinology and Metabolism, Graduate School of Medicine, Yokohama-City University, Yokohama, Japan, 236-0004, Japan.
| | - Yu Togashi
- Department of Endocrinology and Metabolism, Graduate School of Medicine, Yokohama-City University, Yokohama, Japan, 236-0004, Japan
| | - Shunsuke Yamazaki
- Department of Endocrinology and Metabolism, Graduate School of Medicine, Yokohama-City University, Yokohama, Japan, 236-0004, Japan
| | - Tomoko Okuyama
- Department of Endocrinology and Metabolism, Graduate School of Medicine, Yokohama-City University, Yokohama, Japan, 236-0004, Japan
| | - Mayu Kyohara
- Department of Endocrinology and Metabolism, Graduate School of Medicine, Yokohama-City University, Yokohama, Japan, 236-0004, Japan
| | - Hiromi Konishi
- Department of Endocrinology and Metabolism, Graduate School of Medicine, Yokohama-City University, Yokohama, Japan, 236-0004, Japan
| | - Yasuo Terauchi
- Department of Endocrinology and Metabolism, Graduate School of Medicine, Yokohama-City University, Yokohama, Japan, 236-0004, Japan.
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42
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D'souza AM, Neumann UH, Glavas MM, Kieffer TJ. The glucoregulatory actions of leptin. Mol Metab 2017; 6:1052-1065. [PMID: 28951828 PMCID: PMC5605734 DOI: 10.1016/j.molmet.2017.04.011] [Citation(s) in RCA: 122] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 04/18/2017] [Accepted: 04/24/2017] [Indexed: 12/28/2022] Open
Abstract
Background The hormone leptin is an important regulator of metabolic homeostasis, able to inhibit food intake and increase energy expenditure. Leptin can also independently lower blood glucose levels, particularly in hyperglycemic models of leptin or insulin deficiency. Despite significant efforts and relevance to diabetes, the mechanisms by which leptin acts to regulate blood glucose levels are not fully understood. Scope of review Here we assess literature relevant to the glucose lowering effects of leptin. Leptin receptors are widely expressed in multiple cell types, and we describe both peripheral and central effects of leptin that may be involved in lowering blood glucose. In addition, we summarize the potential clinical application of leptin in regulating glucose homeostasis. Major conclusions Leptin exerts a plethora of metabolic effects on various tissues including suppressing production of glucagon and corticosterone, increasing glucose uptake, and inhibiting hepatic glucose output. A more in-depth understanding of the mechanisms of the glucose-lowering actions of leptin may reveal new strategies to treat metabolic disorders.
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Affiliation(s)
- Anna M D'souza
- Department of Cellular and Physiological Sciences, University of British Columbia, 2350 Health Sciences Mall, Vancouver, British Columbia V6T 1Z3, Canada
| | - Ursula H Neumann
- Department of Cellular and Physiological Sciences, University of British Columbia, 2350 Health Sciences Mall, Vancouver, British Columbia V6T 1Z3, Canada
| | - Maria M Glavas
- Department of Cellular and Physiological Sciences, University of British Columbia, 2350 Health Sciences Mall, Vancouver, British Columbia V6T 1Z3, Canada
| | - Timothy J Kieffer
- Department of Cellular and Physiological Sciences, University of British Columbia, 2350 Health Sciences Mall, Vancouver, British Columbia V6T 1Z3, Canada.,Department of Surgery, University of British Columbia, 2350 Health Sciences Mall, Vancouver, British Columbia V6T 1Z3, Canada
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43
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Morioka T, Emoto M, Yamazaki Y, Kurajoh M, Motoyama K, Mori K, Fukumoto S, Shioi A, Shoji T, Inaba M. Plasma soluble leptin receptor levels are associated with pancreatic β-cell dysfunction in patients with type 2 diabetes. J Diabetes Investig 2017; 9:55-62. [PMID: 28294581 PMCID: PMC5754521 DOI: 10.1111/jdi.12657] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 02/06/2017] [Accepted: 03/08/2017] [Indexed: 12/20/2022] Open
Abstract
Aims/Introduction A soluble form of the leptin receptor (soluble Ob‐R) in the circulation regulates leptin's bioactivity, and is inversely associated with body adiposity and circulating leptin levels. However, no study has examined the clinical impact of soluble Ob‐R on glucose metabolism in diabetes. The present study aimed to investigate the association of plasma soluble Ob‐R levels with insulin resistance and pancreatic β‐cell function in patients with type 2 diabetes. Materials and Methods A total of 289 Japanese patients with type 2 diabetes were included in the present study. Fasting plasma soluble Ob‐R levels and plasma leptin levels were measured by enzyme‐linked immunosorbent assay. Insulin resistance and pancreatic β‐cell function were estimated by homeostasis model assessment of insulin resistance, homeostasis model assessment of β‐cell function and fasting C‐peptide index. Results The median plasma soluble Ob‐R level and plasma leptin level were 3.4 ng/mL and 23.6 ng/mL, respectively. Plasma soluble Ob‐R levels were negatively correlated with homeostasis model assessment of insulin resistance, homeostasis model assessment of β‐cell function and the C‐peptide index, whereas plasma leptin levels were positively correlated with each index in univariate analyses. Multivariate analyses including plasma soluble Ob‐R levels, plasma leptin levels and use of sulfonylureas, along with age, sex, body mass index and other covariates, showed that soluble Ob‐R levels were independently and negatively associated with homeostasis model assessment of β‐cell function and the C‐peptide index, but not significantly associated with homeostasis model assessment of insulin resistance. Conclusions Plasma soluble Ob‐R levels are independently associated with pancreatic β‐cell function, but not with insulin resistance, in patients with type 2 diabetes. The present study implicates the role of soluble Ob‐R in pancreatic β‐cell dysfunction in type 2 diabetes.
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Affiliation(s)
- Tomoaki Morioka
- Departments of Metabolism, Endocrinology and Molecular Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Masanori Emoto
- Departments of Metabolism, Endocrinology and Molecular Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Yuko Yamazaki
- Departments of Metabolism, Endocrinology and Molecular Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Masafumi Kurajoh
- Departments of Metabolism, Endocrinology and Molecular Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Koka Motoyama
- Departments of Metabolism, Endocrinology and Molecular Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Katsuhito Mori
- Departments of Metabolism, Endocrinology and Molecular Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Shinya Fukumoto
- Premier Preventive Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Atsushi Shioi
- Vascular Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Tetsuo Shoji
- Vascular Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Masaaki Inaba
- Departments of Metabolism, Endocrinology and Molecular Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan
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44
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Restoration of Lepr in β cells of Lepr null mice does not prevent hyperinsulinemia and hyperglycemia. Mol Metab 2017; 6:585-593. [PMID: 28580288 PMCID: PMC5444109 DOI: 10.1016/j.molmet.2017.04.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 04/02/2017] [Accepted: 04/04/2017] [Indexed: 11/22/2022] Open
Abstract
Objective The adipose-derived hormone leptin plays an important role in regulating body weight and glucose homeostasis. Leptin receptors are expressed in the central nervous system as well as peripheral tissues involved in regulating glucose homeostasis, including insulin-producing β cells of the pancreas. Previous studies assessing the role of leptin receptors in β cells used Cre-loxP to disrupt the leptin receptor gene (Lepr) in β cells, but variable results were obtained. Furthermore, recombination of Lepr was observed in the hypothalamus or exocrine pancreas, in addition to the β cells, and Lepr in non-β cells may have compensated for the loss of Lepr in β cells, thus making it difficult to assess the direct effects of Lepr in β cells. To determine the significance of Lepr exclusively in β cells, we chose to selectively restore Lepr in β cells of Lepr null mice (LeprloxTB/loxTB). Materials and methods We used a mouse model in which endogenous expression of Lepr was disrupted by a loxP-flanked transcription blocker (LeprloxTB/loxTB), but was restored by Cre recombinase knocked into the Ins1 gene, which is specifically expressed in β cells (Ins1Cre). We bred LeprloxTB/loxTB and Ins1Cre mice to generate LeprloxTB/loxTB and LeprloxTB/loxTBIns1Cre mice, as well as Leprwt/wt and Leprwt/wtIns1Cre littermate mice. Male and female mice were weighed weekly between 6 and 11 weeks of age and fasting blood glucose was measured during this time. Oral glucose was administered to mice aged 7–12 weeks to assess glucose tolerance and insulin secretion. Relative β and α cell area and islet size were also assessed by immunostaining and analysis of pancreas sections of 12–14 week old mice. Results Male and female LeprloxTB/loxTB mice, lacking whole-body expression of Lepr, had a phenotype similar to db/db mice characterized by obesity, hyperinsulinemia, glucose intolerance, and impaired glucose stimulated insulin secretion. Despite restoring Lepr in β cells of LeprloxTB/loxTB mice, fasting insulin levels, blood glucose levels and body weight were comparable between LeprloxTB/loxTBIns1Cre mice and LeprloxTB/loxTB littermates. Furthermore, glucose tolerance and insulin secretion in male and female LeprloxTB/loxTBIns1Cre mice were similar to that observed in LeprloxTB/loxTB mice. Analysis of pancreatic insulin positive area revealed that restoration of Lepr in β cells of LeprloxTB/loxTB mice did not prevent hyperplasia of insulin positive cells nor did it rescue Glut-2 expression. Conclusion Collectively, these data suggest that direct action of leptin on β cells is insufficient to restore normal insulin secretion and glucose tolerance in mice without leptin receptor signaling elsewhere. Restoration of Lepr in β cells of Lepr null mice does not prevent hyperinsulinemia. Leptin receptors in β cells do not inhibit islet hyperplasia. Hyperglycemia and glucose intolerance persist despite restoration of Lepr in β cells of Lepr null mice.
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45
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Tanabe K, Amo-Shiinoki K, Hatanaka M, Tanizawa Y. Interorgan Crosstalk Contributing to β-Cell Dysfunction. J Diabetes Res 2017; 2017:3605178. [PMID: 28168202 PMCID: PMC5266810 DOI: 10.1155/2017/3605178] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 11/23/2016] [Accepted: 12/21/2016] [Indexed: 01/08/2023] Open
Abstract
Type 2 diabetes mellitus (T2DM) results from pancreatic β-cell failure in the setting of insulin resistance. In the early stages of this disease, pancreatic β-cells meet increased insulin demand by both enhancing insulin-secretory capacity and increasing β-cell mass. As the disease progresses, β-cells fail to maintain these compensatory responses. This involves both extrinsic signals and mediators intrinsic to β-cells, which adversely affect β-cells by impairing insulin secretion, decreasing proliferative capacities, and ultimately causing apoptosis. In recent years, it has increasingly been recognized that changes in circulating levels of various factors from other organs play roles in β-cell dysfunction and cellular loss. In this review, we discuss current knowledge of interorgan communications underlying β-cell failure during the progression of T2DM.
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Affiliation(s)
- Katsuya Tanabe
- Division of Endocrinology, Metabolism, Hematological Science and Therapeutics, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan
- *Katsuya Tanabe:
| | - Kikuko Amo-Shiinoki
- Division of Endocrinology, Metabolism, Hematological Science and Therapeutics, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan
| | - Masayuki Hatanaka
- Division of Endocrinology, Metabolism, Hematological Science and Therapeutics, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan
| | - Yukio Tanizawa
- Division of Endocrinology, Metabolism, Hematological Science and Therapeutics, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan
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Liang T, Qin T, Xie L, Dolai S, Zhu D, Prentice KJ, Wheeler M, Kang Y, Osborne L, Gaisano HY. New Roles of Syntaxin-1A in Insulin Granule Exocytosis and Replenishment. J Biol Chem 2016; 292:2203-2216. [PMID: 28031464 DOI: 10.1074/jbc.m116.769885] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2016] [Indexed: 01/14/2023] Open
Abstract
In type-2 diabetes (T2D), severely reduced islet syntaxin-1A (Syn-1A) levels contribute to insulin secretory deficiency. We generated β-cell-specific Syn-1A-KO (Syn-1A-βKO) mice to mimic β-cell Syn-1A deficiency in T2D. Glucose tolerance tests showed that Syn-1A-βKO mice exhibited blood glucose elevation corresponding to reduced blood insulin levels. Perifusion of Syn-1A-βKO islets showed impaired first- and second-phase glucose-stimulated insulin secretion (GSIS) resulting from reduction in readily releasable pool and granule pool refilling. To unequivocally determine the β-cell exocytotic defects caused by Syn-1A deletion, EM and total internal reflection fluorescence microscopy showed that Syn-1A-KO β-cells had a severe reduction in the number of secretory granules (SGs) docked onto the plasma membrane (PM) at rest and reduced SG recruitment to the PM after glucose stimulation, the latter indicating defects in replenishment of releasable pools required to sustain second-phase GSIS. Whereas reduced predocked SG fusion accounted for reduced first-phase GSIS, selective reduction of exocytosis of short-dock (but not no-dock) newcomer SGs accounted for the reduced second-phase GSIS. These Syn-1A actions on newcomer SGs were partly mediated by Syn-1A interactions with newcomer SG VAMP8.
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Affiliation(s)
- Tao Liang
- From the Departments of Medicine.,Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Tairan Qin
- From the Departments of Medicine.,Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Li Xie
- From the Departments of Medicine.,Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Subhankar Dolai
- From the Departments of Medicine.,Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Dan Zhu
- From the Departments of Medicine.,Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Kacey J Prentice
- Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Michael Wheeler
- Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Youhou Kang
- From the Departments of Medicine.,Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Lucy Osborne
- From the Departments of Medicine.,Molecular Genetics, and
| | - Herbert Y Gaisano
- From the Departments of Medicine, .,Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
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Chen Y, Tian L, Wan S, Xie Y, Chen X, Ji X, Zhao Q, Wang C, Zhang K, Hock JM, Tian H, Yu X. MicroRNA-17-92 cluster regulates pancreatic beta-cell proliferation and adaptation. Mol Cell Endocrinol 2016; 437:213-223. [PMID: 27568466 DOI: 10.1016/j.mce.2016.08.037] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 08/22/2016] [Accepted: 08/23/2016] [Indexed: 10/21/2022]
Abstract
MiR-17-92 cluster contributes to the regulation of mammalian development, aging and tumorigenesis. The functional roles of miR-17-92 in pancreatic beta-cells are largely unknown. In this study, we found that conditional deletion of miR-17-92 in mouse pancreatic beta-cells (miR-17-92βKO) significantly reduces glucose tolerance and the first phase of insulin secretion, despite normal ad libitum fed and fasting glucose levels. Proliferation is down-regulated in pancreatic beta-cells after deleting miR-17-92. MiR-17-92βKO mice show higher phosphatase and tensin homologue (PTEN) and lower phosphorylated AKT in islets. Under high fat diet challenge for 16 weeks, miR-17-92βKO mice lose compensation and exhibit higher glucose levels, and lower insulin secretion. Collectively, these data suggest that miR-17-92 is a critical contributor to molecular mechanisms regulating glucose-stimulated insulin secretion and pancreatic beta-cell adaptation under metabolic stress.
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Affiliation(s)
- Yaxi Chen
- Laboratory of Endocrinology and Metabolism, Department of Endocrinology, National Key Laboratory of Biotherapy/Collaborative Innovation Center of Biotherapy and Cancer Center, West China Hospital, Sichuan University, 610041, PR China
| | - Li Tian
- Laboratory of Endocrinology and Metabolism, Department of Endocrinology, National Key Laboratory of Biotherapy/Collaborative Innovation Center of Biotherapy and Cancer Center, West China Hospital, Sichuan University, 610041, PR China
| | - Shan Wan
- Laboratory of Endocrinology and Metabolism, Department of Endocrinology, National Key Laboratory of Biotherapy/Collaborative Innovation Center of Biotherapy and Cancer Center, West China Hospital, Sichuan University, 610041, PR China
| | - Ying Xie
- Laboratory of Endocrinology and Metabolism, Department of Endocrinology, National Key Laboratory of Biotherapy/Collaborative Innovation Center of Biotherapy and Cancer Center, West China Hospital, Sichuan University, 610041, PR China
| | - Xiang Chen
- Laboratory of Endocrinology and Metabolism, Department of Endocrinology, National Key Laboratory of Biotherapy/Collaborative Innovation Center of Biotherapy and Cancer Center, West China Hospital, Sichuan University, 610041, PR China
| | - Xiao Ji
- Laboratory of Endocrinology and Metabolism, Department of Endocrinology, National Key Laboratory of Biotherapy/Collaborative Innovation Center of Biotherapy and Cancer Center, West China Hospital, Sichuan University, 610041, PR China
| | - Qian Zhao
- Laboratory of Endocrinology and Metabolism, Department of Endocrinology, National Key Laboratory of Biotherapy/Collaborative Innovation Center of Biotherapy and Cancer Center, West China Hospital, Sichuan University, 610041, PR China
| | - Chunyu Wang
- Laboratory of Endocrinology and Metabolism, Department of Endocrinology, National Key Laboratory of Biotherapy/Collaborative Innovation Center of Biotherapy and Cancer Center, West China Hospital, Sichuan University, 610041, PR China
| | - Kun Zhang
- Laboratory of Endocrinology and Metabolism, Department of Endocrinology, National Key Laboratory of Biotherapy/Collaborative Innovation Center of Biotherapy and Cancer Center, West China Hospital, Sichuan University, 610041, PR China
| | - Janet M Hock
- The Polis Center, Indiana University-Purdue University Indianapolis, 1200 Waterway Blvd # 100, Indianapolis, IN 46202, USA
| | - Haoming Tian
- Laboratory of Endocrinology and Metabolism, Department of Endocrinology, National Key Laboratory of Biotherapy/Collaborative Innovation Center of Biotherapy and Cancer Center, West China Hospital, Sichuan University, 610041, PR China
| | - Xijie Yu
- Laboratory of Endocrinology and Metabolism, Department of Endocrinology, National Key Laboratory of Biotherapy/Collaborative Innovation Center of Biotherapy and Cancer Center, West China Hospital, Sichuan University, 610041, PR China.
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D'souza AM, Johnson JD, Clee SM, Kieffer TJ. Suppressing hyperinsulinemia prevents obesity but causes rapid onset of diabetes in leptin-deficient Lepob/ob mice. Mol Metab 2016; 5:1103-1112. [PMID: 27818936 PMCID: PMC5081422 DOI: 10.1016/j.molmet.2016.09.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Revised: 09/11/2016] [Accepted: 09/14/2016] [Indexed: 12/27/2022] Open
Abstract
Objective Hyperinsulinemia is commonly associated with obesity. Mice deficient in the adipose-derived hormone leptin (Lepob/ob) develop hyperinsulinemia prior to onset of obesity and glucose intolerance. Whether the excess of circulating insulin is a major contributor to obesity and impaired glucose homeostasis in Lepob/ob mice is unclear. It has been reported previously that diet-induced obesity in mice can be prevented by reducing insulin gene dosage. In the present study, we examined the effects of genetic insulin reduction in Lepob/ob mice on circulating insulin, body composition, and glucose homeostasis. Methods Leptin expressing (Lepwt/wt) mice lacking 3 insulin alleles were crossed with Lepob/ob mice to generate Lepob/ob and Lepwt/wt littermates lacking 1 (Ins1+/+;Ins2+/−), 2 (Ins1+/+;Ins2−/−) or 3 (Ins1+/−;Ins2−/−) insulin alleles. Animals were assessed for body weight gain, body composition, glucose homeostasis, and islet morphology. Results We found that in young Lepob/ob mice, loss of 2 or 3 insulin alleles reduced plasma insulin levels by 75–95% and attenuated body weight gain by 50–90% compared to Ins1+/+;Ins2+/−;Lepob/ob mice. This corresponded with ∼30% and ∼50% reduced total body fat in Ins1+/+;Ins2−/−;Lepob/ob and Ins1+/−;Ins2−/−;Lepob/ob mice, respectively. Loss of 2 or 3 insulin alleles in young Lepob/ob mice resulted in onset of fasting hyperglycemia by 4 weeks of age, exacerbated glucose intolerance, and abnormal islet morphology. In contrast, loss of 1,2 or 3 insulin alleles in Lepwt/wt mice did not significantly alter plasma insulin levels, body weight, fat mass, fasting glycemia, or glucose tolerance. Conclusion Taken together, our findings indicate that hyperinsulinemia is required for excess adiposity in Lepob/ob mice and sufficient insulin production is necessary to maintain euglycemia in the absence of leptin. Loss of 2 or 3 insulin alleles results in a dose dependent decrease of circulating insulin levels and body fat in Lepob/ob mice. Loss of 2 or 3 insulin alleles produced a greater reduction in body weight in male as compared to female Lepob/ob mice. Attenuation of hyperinsulinemia accelerates onset of hyperglycemia in Lepob/ob mice.
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Affiliation(s)
- Anna M D'souza
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada.
| | - James D Johnson
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada.
| | - Susanne M Clee
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada.
| | - Timothy J Kieffer
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada; Department of Surgery, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada.
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Denroche HC, Glavas MM, Tudurí E, Karunakaran S, Quong WL, Philippe M, Britton HM, Clee SM, Kieffer TJ. Disrupted Leptin Signaling in the Lateral Hypothalamus and Ventral Premammillary Nucleus Alters Insulin and Glucagon Secretion and Protects Against Diet-Induced Obesity. Endocrinology 2016; 157:2671-85. [PMID: 27183315 DOI: 10.1210/en.2015-1998] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Leptin signaling in the central nervous system, and particularly the arcuate hypothalamic nucleus, is important for regulating energy and glucose homeostasis. However, the roles of extra-arcuate leptin responsive neurons are less defined. In the current study, we generated mice with widespread inactivation of the long leptin receptor isoform in the central nervous system via Synapsin promoter-driven Cre (Lepr(flox/flox) Syn-cre mice). Within the hypothalamus, leptin signaling was disrupted in the lateral hypothalamic area (LHA) and ventral premammillary nucleus (PMV) but remained intact in the arcuate hypothalamic nucleus and ventromedial hypothalamic nucleus, dorsomedial hypothalamic nucleus, and nucleus of the tractus solitarius. To investigate the role of LHA/PMV neuronal leptin signaling, we examined glucose and energy homeostasis in Lepr(flox/flox) Syn-cre mice and Lepr(flox/flox) littermates under basal and diet-induced obese conditions and tested the role of LHA/PMV neurons in leptin-mediated glucose lowering in streptozotocin-induced diabetes. Lepr(flox/flox) Syn-cre mice did not have altered body weight or blood glucose levels but were hyperinsulinemic and had enhanced glucagon secretion in response to experimental hypoglycemia. Surprisingly, when placed on a high-fat diet, Lepr(flox/flox) Syn-cre mice were protected from weight gain, glucose intolerance, and diet-induced hyperinsulinemia. Peripheral leptin administration lowered blood glucose in streptozotocin-induced diabetic Lepr(flox/flox) Syn-cre mice as effectively as in Lepr(flox/flox) littermate controls. Collectively these findings suggest that leptin signaling in LHA/PMV neurons is not critical for regulating glucose levels but has an indispensable role in the regulation of insulin and glucagon levels and, may promote the development of diet-induced hyperinsulinemia and weight gain.
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Affiliation(s)
- Heather C Denroche
- Laboratory of Molecular and Cellular Medicine (H.C.D., M.M.G., E.T., W.L.Q., M.P., H.M.B., T.J.K.) and Laboratory of the Genetics of Obesity and Diabetes (S.K., S.M.C.), Department of Cellular and Physiological Sciences, Life Sciences Institute, and Department of Surgery (T.J.K.), University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
| | - Maria M Glavas
- Laboratory of Molecular and Cellular Medicine (H.C.D., M.M.G., E.T., W.L.Q., M.P., H.M.B., T.J.K.) and Laboratory of the Genetics of Obesity and Diabetes (S.K., S.M.C.), Department of Cellular and Physiological Sciences, Life Sciences Institute, and Department of Surgery (T.J.K.), University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
| | - Eva Tudurí
- Laboratory of Molecular and Cellular Medicine (H.C.D., M.M.G., E.T., W.L.Q., M.P., H.M.B., T.J.K.) and Laboratory of the Genetics of Obesity and Diabetes (S.K., S.M.C.), Department of Cellular and Physiological Sciences, Life Sciences Institute, and Department of Surgery (T.J.K.), University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
| | - Subashini Karunakaran
- Laboratory of Molecular and Cellular Medicine (H.C.D., M.M.G., E.T., W.L.Q., M.P., H.M.B., T.J.K.) and Laboratory of the Genetics of Obesity and Diabetes (S.K., S.M.C.), Department of Cellular and Physiological Sciences, Life Sciences Institute, and Department of Surgery (T.J.K.), University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
| | - Whitney L Quong
- Laboratory of Molecular and Cellular Medicine (H.C.D., M.M.G., E.T., W.L.Q., M.P., H.M.B., T.J.K.) and Laboratory of the Genetics of Obesity and Diabetes (S.K., S.M.C.), Department of Cellular and Physiological Sciences, Life Sciences Institute, and Department of Surgery (T.J.K.), University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
| | - Marion Philippe
- Laboratory of Molecular and Cellular Medicine (H.C.D., M.M.G., E.T., W.L.Q., M.P., H.M.B., T.J.K.) and Laboratory of the Genetics of Obesity and Diabetes (S.K., S.M.C.), Department of Cellular and Physiological Sciences, Life Sciences Institute, and Department of Surgery (T.J.K.), University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
| | - Heidi M Britton
- Laboratory of Molecular and Cellular Medicine (H.C.D., M.M.G., E.T., W.L.Q., M.P., H.M.B., T.J.K.) and Laboratory of the Genetics of Obesity and Diabetes (S.K., S.M.C.), Department of Cellular and Physiological Sciences, Life Sciences Institute, and Department of Surgery (T.J.K.), University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
| | - Susanne M Clee
- Laboratory of Molecular and Cellular Medicine (H.C.D., M.M.G., E.T., W.L.Q., M.P., H.M.B., T.J.K.) and Laboratory of the Genetics of Obesity and Diabetes (S.K., S.M.C.), Department of Cellular and Physiological Sciences, Life Sciences Institute, and Department of Surgery (T.J.K.), University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
| | - Timothy J Kieffer
- Laboratory of Molecular and Cellular Medicine (H.C.D., M.M.G., E.T., W.L.Q., M.P., H.M.B., T.J.K.) and Laboratory of the Genetics of Obesity and Diabetes (S.K., S.M.C.), Department of Cellular and Physiological Sciences, Life Sciences Institute, and Department of Surgery (T.J.K.), University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
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Stern JH, Rutkowski JM, Scherer PE. Adiponectin, Leptin, and Fatty Acids in the Maintenance of Metabolic Homeostasis through Adipose Tissue Crosstalk. Cell Metab 2016; 23:770-84. [PMID: 27166942 PMCID: PMC4864949 DOI: 10.1016/j.cmet.2016.04.011] [Citation(s) in RCA: 675] [Impact Index Per Article: 84.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Metabolism research has made tremendous progress over the last several decades in establishing the adipocyte as a central rheostat in the regulation of systemic nutrient and energy homeostasis. Operating at multiple levels of control, the adipocyte communicates with organ systems to adjust gene expression, glucoregulatory hormone exocytosis, enzymatic reactions, and nutrient flux to equilibrate the metabolic demands of a positive or negative energy balance. The identification of these mechanisms has great potential to identify novel targets for the treatment of diabetes and related metabolic disorders. Herein, we review the central role of the adipocyte in the maintenance of metabolic homeostasis, highlighting three critical mediators: adiponectin, leptin, and fatty acids.
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Affiliation(s)
- Jennifer H Stern
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Joseph M Rutkowski
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Philipp E Scherer
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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