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Ataş M, Bereketoglu C. The toxicity assessment of phosmet on development, reproduction, and gene expression in Daphnia magna. PeerJ 2024; 12:e17034. [PMID: 38436013 PMCID: PMC10908259 DOI: 10.7717/peerj.17034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 02/08/2024] [Indexed: 03/05/2024] Open
Abstract
The use of pesticides to control pests, weeds, and diseases or to regulate plant growth is indispensable in agricultural production. However, the excessive use of these chemicals has led to significant concern about their potential negative impacts on health and the environment. Phosmet is one such pesticide that is commonly used on plants and animals against cold moth, aphids, mites, suckers, and fruit flies. Here, we investigated the effects of phosmet on a model organism, Daphnia magna using acute and chronic toxicity endpoints such as lethality, mobility, genotoxicity, reproduction, and gene expression. We performed survival experiments in six-well plates at seven different concentrations (0.01, 0.1, 1, 10, 25, 50, 100 μM) as well as the control in three replicates. We observed statistically significant mortality rates at 25 µM and above upon 24 h of exposure, and at 1 µM and above following 48 h of exposure. Genotoxicity analysis, reproduction assay and qPCR analysis were carried out at concentrations of 0.01 and 0.1 μM phosmet as these concentrations did not show any lethality. Comet assay showed that exposure to phosmet resulted in significant DNA damage in the cells. Interestingly, 0.1 μM phosmet produced more offspring per adult compared to the control group indicating a hormetic response. Gene expression profiles demonstrated several genes involved in different physiological pathways, including oxidative stress, detoxification, immune system, hypoxia and iron homeostasis. Taken together, our results indicate that phosmet has negative effects on Daphnia magna in a dose- and time-dependent manner and could also induce lethal and physiological toxicities to other aquatic organisms.
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Affiliation(s)
- Mustafa Ataş
- Managing Chemical, Biological, Radioactive, Nuclear Risks, Iskenderun Technical University, Hatay, Turkey
| | - Ceyhun Bereketoglu
- Department of Bioengineering, Marmara University, Istanbul, Turkey
- Department of Biomedical Engineering, Iskenderun Technical University, Hatay, Turkey
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2
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Abstract
Metabolic diseases, including obesity, diabetes mellitus and cardiovascular disease, are a major threat to health in the modern world, but efforts to understand the underlying mechanisms and develop rational treatments are limited by the lack of appropriate human model systems. Notably, advances in stem cell and organoid technology allow the generation of cellular models that replicate the histological, molecular and physiological properties of human organs. Combined with marked improvements in gene editing tools, human stem cells and organoids provide unprecedented systems for studying mechanisms of metabolic diseases. Here, we review progress made over the past decade in the generation and use of stem cell-derived metabolic cell types and organoids in metabolic disease research, especially obesity and liver diseases. In particular, we discuss the limitations of animal models and the advantages of stem cells and organoids, including their application to metabolic diseases. We also discuss mechanisms of drug action, understanding the efficacy and toxicity of existing therapies, screening for new treatments and pursuing personalized therapies. We highlight the potential of combining stem cell-derived organoids with gene editing and functional genomics to revolutionize the approach to finding treatments for metabolic diseases.
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Affiliation(s)
- Wenxiang Hu
- Department of Basic Research, Guangzhou Laboratory, Guangdong, China.
- Institute for Diabetes, Obesity, and Metabolism, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
| | - Mitchell A Lazar
- Institute for Diabetes, Obesity, and Metabolism, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
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3
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Di(isononyl) cyclohexane-1,2-dicarboxylate (DINCH) alters transcriptional profiles, lipid metabolism and behavior in zebrafish larvae. Heliyon 2021; 7:e07951. [PMID: 34553086 PMCID: PMC8441171 DOI: 10.1016/j.heliyon.2021.e07951] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 08/22/2021] [Accepted: 09/03/2021] [Indexed: 01/11/2023] Open
Abstract
Plasticizers are commonly used in different consumer goods and personal care products to provide flexibility, durability and elasticity to polymers. Due to their reported toxicity, the use of several plasticizers, including phthalates has been regulated and/or banned from the market. Di(isononyl) cyclohexane-1,2-dicarboxylate (DINCH) is an alternative plasticizer that was introduced to replace toxic plasticizers. Increasing global demand and lack of toxicity data and safety assessment of DINCH have raised the concern to human and animal health. Hence, in the present study, we investigated the adverse effects of DINCH (at concentrations ranging from 0.01 to 10 μM) in early developmental stages of zebrafish using different endpoints such as hatching rate, developmental abnormalities, lipid content, behavior analysis and gene expression. We found that DINCH caused hatching delay in a dose-dependent manner and altered the expression of genes involved in stress response. Lipid staining using Oil Red O stain showed a slight lipid accumulation around the yolk, brain, eye and neck with increasing concentration. Genes associated with lipid transport such as fatty acid synthesis, β-oxidation, elongation, lipid transport were significantly altered by DINCH. Genes involved in cholesterol biosynthesis and homeostasis were also affected by DINCH indicating possible developmental neurotoxicity. Behavioral analysis of larvae demonstrated a distinct locomotor activity upon exposure to DINCH. The present data shows that DINCH could induce physiological and metabolic toxicity to aquatic organisms. Hence, further analyses and environmental monitoring of DINCH should be conducted to determine its safety and toxicity levels.
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4
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Salazar J, Chávez-Castillo M, Rojas J, Ortega A, Nava M, Pérez J, Rojas M, Espinoza C, Chacin M, Herazo Y, Angarita L, Rojas DM, D'Marco L, Bermudez V. Is "Leptin Resistance" Another Key Resistance to Manage Type 2 Diabetes? Curr Diabetes Rev 2020; 16:733-749. [PMID: 31886750 DOI: 10.2174/1573399816666191230111838] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 11/08/2019] [Accepted: 12/12/2019] [Indexed: 02/06/2023]
Abstract
Although novel pharmacological options for the treatment of type 2 diabetes mellitus (DM2) have been observed to modulate the functionality of several key organs in glucose homeostasis, successful regulation of insulin resistance (IR), body weight management, and pharmacological treatment of obesity remain notable problems in endocrinology. Leptin may be a pivotal player in this scenario, as an adipokine which centrally regulates appetite and energy balance. In obesity, excessive caloric intake promotes a low-grade inflammatory response, which leads to dysregulations in lipid storage and adipokine secretion. In turn, these entail alterations in leptin sensitivity, leptin transport across the blood-brain barrier and defects in post-receptor signaling. Furthermore, hypothalamic inflammation and endoplasmic reticulum stress may increase the expression of molecules which may disrupt leptin signaling. Abundant evidence has linked obesity and leptin resistance, which may precede or occur simultaneously to IR and DM2. Thus, leptin sensitivity may be a potential early therapeutic target that demands further preclinical and clinical research. Modulators of insulin sensitivity have been tested in animal models and small clinical trials with promising results, especially in combination with agents such as amylin and GLP-1 analogs, in particular, due to their central activity in the hypothalamus.
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Affiliation(s)
- Juan Salazar
- Endocrine and Metabolic Diseases Research Center, School of Medicine, The University of Zulia, Maracaibo, Venezuela
| | - Mervin Chávez-Castillo
- Endocrine and Metabolic Diseases Research Center, School of Medicine, The University of Zulia, Maracaibo, Venezuela
| | - Joselyn Rojas
- Division of Pulmonary and Critical Care Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States
| | - Angel Ortega
- Endocrine and Metabolic Diseases Research Center, School of Medicine, The University of Zulia, Maracaibo, Venezuela
| | - Manuel Nava
- Endocrine and Metabolic Diseases Research Center, School of Medicine, The University of Zulia, Maracaibo, Venezuela
| | - José Pérez
- Endocrine and Metabolic Diseases Research Center, School of Medicine, The University of Zulia, Maracaibo, Venezuela
| | - Milagros Rojas
- Endocrine and Metabolic Diseases Research Center, School of Medicine, The University of Zulia, Maracaibo, Venezuela
| | | | - Maricarmen Chacin
- Universidad Simon Bolivar, Facultad de Ciencias de la Salud, Barranquilla, Colombia
| | - Yaneth Herazo
- Universidad Simon Bolivar, Facultad de Ciencias de la Salud, Barranquilla, Colombia
| | - Lissé Angarita
- Escuela de Nutricion y Dietetica, Facultad de Medicina, Universidad Andres Bello, Sede Concepcion, Chile
| | - Diana Marcela Rojas
- Escuela de Nutricion y Dietética, Facultad de Medicina, Universidad Andres Bello, Santiago, Chile
| | - Luis D'Marco
- Hospital Clinico de Valencia, INCLIVA, Servicio de Nefrologia, Valencia, Spain
| | - Valmore Bermudez
- Universidad Simon Bolivar, Facultad de Ciencias de la Salud, Barranquilla, Colombia
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5
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Bai B, Yang W, Fu Y, Foon HL, Tay WT, Yang K, Luo C, Gunaratne J, Lee P, Zile MR, Xu A, Chin CW, Lam CS, Han W, Wang Y. Seipin Knockout Mice Develop Heart Failure With Preserved Ejection Fraction. JACC Basic Transl Sci 2019; 4:924-937. [PMID: 31909301 PMCID: PMC6939002 DOI: 10.1016/j.jacbts.2019.07.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 07/15/2019] [Accepted: 07/16/2019] [Indexed: 01/08/2023]
Abstract
The lean diabetic patients with heart failure with preserved ejection fraction (HFpEF) in Asia suffer from adverse clinical outcomes and poor life quality. The suitable animal models are urgently needed for mechanistic study and therapeutic innovations. Our study reports that lipodystrophic mice with seipin depletion are lean, diabetic, and recapitulate major manifestations of clinical HFpEF, thereby clarifying that lean diabetes per se may produce HFpEF characteristics. We further demonstrate that increased cardiac titin phosphorylation and reactive interstitial fibrosis associated with neutrophil extracellular traps lead to left ventricular stiffness and suggest that both pathways may be potential therapeutic targets in Asian HFpEF patients.
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Key Words
- Ctrl, control (mice)
- EDPVR, end-diastolic pressure–volume relationship
- HFpEF, heart failure with preserved ejection fraction
- IQR, interquartile range
- LA, left atrial
- LV, left ventricular
- NET, neutrophil extracellular trap
- PEVK, proline, glutamate, valine, and lysine
- SKO, seipin knockout
- fibrosis
- heart failure with preserved ejection fraction
- neutrophil
- seipin
- titin
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Affiliation(s)
- Bo Bai
- Singapore Bioimaging Consortium, Agency for Science, Technology and Research, Singapore
- State Key Laboratory of Pharmaceutical Biotechnology and Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong, China
| | - Wulin Yang
- Anhui Province Key Laboratory of Medical Physics and Technology, Center of Medical Physics and Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China
- Hefei Cancer Hospital, Chinese Academy of Sciences, Hefei, China
| | - Yanyun Fu
- Singapore Bioimaging Consortium, Agency for Science, Technology and Research, Singapore
| | - Hannah Lee Foon
- Translational Biomedical Proteomics, Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore
| | - Wan Ting Tay
- National Heart Centre Singapore and Duke-National University of Singapore, Singapore
| | - Kangmin Yang
- State Key Laboratory of Pharmaceutical Biotechnology and Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong, China
| | - Cuiting Luo
- State Key Laboratory of Pharmaceutical Biotechnology and Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong, China
| | - Jayantha Gunaratne
- Translational Biomedical Proteomics, Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore
| | - Philip Lee
- Singapore Bioimaging Consortium, Agency for Science, Technology and Research, Singapore
| | - Michael R. Zile
- Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
- Ralph H. Johnson Department of Veterans Affairs Medical Center, Charleston, South Carolina
| | - Aimin Xu
- State Key Laboratory of Pharmaceutical Biotechnology and Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong, China
- Department of Medicine, The University of Hong Kong, Hong Kong, China
| | - Calvin W.L. Chin
- National Heart Centre Singapore and Duke-National University of Singapore, Singapore
| | - Carolyn S.P. Lam
- National Heart Centre Singapore and Duke-National University of Singapore, Singapore
| | - Weiping Han
- Singapore Bioimaging Consortium, Agency for Science, Technology and Research, Singapore
| | - Yu Wang
- State Key Laboratory of Pharmaceutical Biotechnology and Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong, China
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6
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Abstract
PURPOSE OF REVIEW Obesity is a major risk factor for type 2 diabetes. Although adipose tissue allows storage of excess calories in periods of overnutrition, in obesity, adipose tissue metabolism becomes dysregulated and can promote metabolic diseases. This review discusses recent advances in understandings how adipocyte metabolism impacts metabolic homeostasis. RECENT FINDINGS The ability of adipocytes to synthesize lipids from glucose is a marker of metabolic fitness, e.g., low de novo lipogenesis (DNL) in adipocytes correlates with insulin resistance in obesity. Adipocyte DNL may promote synthesis of special "insulin sensitizing" signaling lipids that act hormonally. However, each metabolic intermediate in the DNL pathway (i.e., citrate, acetyl-CoA, malonyl-CoA, and palmitate) also has second messenger functions. Mounting evidence suggests these signaling functions may also be important for maintaining healthy adipocytes. While adipocyte DNL contributes to lipid storage, lipid precursors may have additional second messenger functions critical for maintaining adipocyte health, and thus systemic metabolic homeostasis.
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Affiliation(s)
- Wen-Yu Hsiao
- Program in Molecular Medicine, University of Massachusetts Medical School, 373 Plantation Street, Worcester, MA, 01605, USA
| | - David A Guertin
- Program in Molecular Medicine, University of Massachusetts Medical School, 373 Plantation Street, Worcester, MA, 01605, USA.
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7
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Keeley T, Kirov A, Koh WY, Demambro V, Bergquist I, Cotter J, Caradonna P, Siviski ME, Best B, Henderson T, Rosen CJ, Liaw L, Prudovsky I, Small DJ. Resistance to visceral obesity is associated with increased locomotion in mice expressing an endothelial cell-specific fibroblast growth factor 1 transgene. Physiol Rep 2019; 7:e14034. [PMID: 30972920 PMCID: PMC6458108 DOI: 10.14814/phy2.14034] [Citation(s) in RCA: 4] [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: 12/11/2018] [Revised: 02/19/2019] [Accepted: 02/20/2019] [Indexed: 12/13/2022] Open
Abstract
Overdevelopment of visceral adipose is positively correlated with the etiology of obesity-associated pathologies including cardiovascular disease and insulin resistance. However, identification of genetic, molecular, and physiological factors regulating adipose development and function in response to nutritional stress is incomplete. Fibroblast Growth Factor 1 (FGF1) is a cytokine expressed and released by both adipocytes and endothelial cells under hypoxia, thermal, and oxidative stress. Expression of Fibroblast Growth Factor 1 (FGF1) in adipose is required for normal depot development and remodeling. Loss of FGF1 leads to deleterious changes in adipose morphology, metabolism, and insulin resistance. Conversely, diabetic and obese mice injected with recombinant FGF1 display improvements in insulin sensitivity and a reduction in adiposity. We report in this novel, in vivo study that transgenic mice expressing an endothelial-specific FGF1 transgene (FGF1-Tek) are resistant to high-fat diet-induced abdominal adipose accretion and are more glucose-tolerant than wild-type control animals. Metabolic chamber analyses indicate that suppression of the development of visceral adiposity and insulin resistance was not associated with alterations in appetite or resting metabolic rate in the FGF1-Tek strain. Instead, FGF1-Tek mice display increased locomotor activity that likely promotes the utilization of dietary fatty acids before they can accumulate in adipose and liver. This study provides insight into the impact that genetic differences dictating the production of FGF1 has on the risk for developing obesity-related metabolic disease in response to nutritional stress.
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Affiliation(s)
- Tyler Keeley
- Department of Chemistry and PhysicsCollege of Arts and SciencesUniversity of New EnglandBiddefordMaine
| | - Aleksandr Kirov
- Center for Molecular MedicineMaine Medical Center Research InstituteScarboroughMaine
| | - Woon Yuen Koh
- Department of Mathematical SciencesCollege of Arts and SciencesUniversity of New EnglandBiddefordMaine
| | - Victoria Demambro
- Center for Molecular MedicineMaine Medical Center Research InstituteScarboroughMaine
| | - Ivy Bergquist
- Center for Excellence in NeuroscienceCollege of MedicineUniversity of New EnglandBiddefordMaine
| | - Jessica Cotter
- Department of Chemistry and PhysicsCollege of Arts and SciencesUniversity of New EnglandBiddefordMaine
| | - Peter Caradonna
- Department of Chemistry and PhysicsCollege of Arts and SciencesUniversity of New EnglandBiddefordMaine
| | - Matthew E. Siviski
- Center for Molecular MedicineMaine Medical Center Research InstituteScarboroughMaine
| | - Bradley Best
- Department of Chemistry and PhysicsCollege of Arts and SciencesUniversity of New EnglandBiddefordMaine
| | - Terry Henderson
- Center for Molecular MedicineMaine Medical Center Research InstituteScarboroughMaine
| | - Clifford J. Rosen
- Center for Molecular MedicineMaine Medical Center Research InstituteScarboroughMaine
| | - Lucy Liaw
- Center for Molecular MedicineMaine Medical Center Research InstituteScarboroughMaine
| | - Igor Prudovsky
- Center for Molecular MedicineMaine Medical Center Research InstituteScarboroughMaine
| | - Deena J. Small
- Department of Chemistry and PhysicsCollege of Arts and SciencesUniversity of New EnglandBiddefordMaine
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8
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Abstract
The zebrafish model facilitates the study of lipid metabolism and transport during development. Here, we outline methods to introduce traceable fluorescent or radiolabeled fatty acids into zebrafish embryos and larvae at various developmental stages. Labeled fatty acids can be injected into the large yolk cell prior to the development of digestive organs when the larvae is entirely dependent on the yolk for its nutrition (lecithotrophic state). Once zebrafish are able to consume exogenous food, labeled fatty acids can be incorporated into their food. Our group and others have demonstrated that the transport and processing of these injected or ingested fatty acid analogs can be followed through microscopy and/or biochemical analysis. These techniques can be easily combined with targeted antisense approaches, transgenics, or drug treatments (see Note 1 ), allowing studies of lipid cell biology and metabolism that are exceedingly difficult or impossible in mammals.
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Affiliation(s)
- Erin M Zeituni
- Department of Embryology, Carnegie Institution for Science, 3520 San Martin Drive, Baltimore, MD, USA
| | - Steven A Farber
- Department of Embryology, Carnegie Institution for Science, 3520 San Martin Drive, Baltimore, MD, USA.
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9
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Minakuchi H, Wakino S, Hosoya K, Sueyasu K, Hasegawa K, Shinozuka K, Yoshifuji A, Futatsugi K, Komatsu M, Kanda T, Tokuyama H, Hayashi K, Itoh H. The role of adipose tissue asymmetric dimethylarginine/dimethylarginine dimethylaminohydrolase pathway in adipose tissue phenotype and metabolic abnormalities in subtotally nephrectomized rats. Nephrol Dial Transplant 2015; 31:413-23. [DOI: 10.1093/ndt/gfv367] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 09/09/2015] [Indexed: 01/12/2023] Open
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10
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CHEN KAN, WANG CHANGQIAN, FAN YUQI, XIE YUSHUI, YIN ZHAOFANG, XU ZUOJUN, ZHANG HUILI, CAO JIATIAN, HAN ZHIHUA, WANG YUE, SONG DONGQIANG. Optimizing methods for the study of intravascular lipid metabolism in zebrafish. Mol Med Rep 2014; 11:1871-6. [DOI: 10.3892/mmr.2014.2895] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Accepted: 09/18/2014] [Indexed: 11/06/2022] Open
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11
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Corvera S, Gealekman O. Adipose tissue angiogenesis: impact on obesity and type-2 diabetes. Biochim Biophys Acta Mol Basis Dis 2013; 1842:463-72. [PMID: 23770388 DOI: 10.1016/j.bbadis.2013.06.003] [Citation(s) in RCA: 138] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Revised: 05/24/2013] [Accepted: 06/01/2013] [Indexed: 12/17/2022]
Abstract
The growth and function of tissues are critically dependent on their vascularization. Adipose tissue is capable of expanding many-fold during adulthood, therefore requiring the formation of new vasculature to supply growing and proliferating adipocytes. The expansion of the vasculature in adipose tissue occurs through angiogenesis, where new blood vessels develop from those pre-existing within the tissue. Inappropriate angiogenesis may underlie adipose tissue dysfunction in obesity, which in turn increases type-2 diabetes risk. In addition, genetic and developmental factors involved in vascular patterning may define the size and expandability of diverse adipose tissue depots, which are also associated with type-2 diabetes risk. Moreover, the adipose tissue vasculature appears to be the niche for pre-adipocyte precursors, and factors that affect angiogenesis may directly impact the generation of new adipocytes. Here we review recent advances on the basic mechanisms of angiogenesis, and on the role of angiogenesis in adipose tissue development and obesity. A substantial amount of data points to a deficit in adipose tissue angiogenesis as a contributing factor to insulin resistance and metabolic disease in obesity. These emerging findings support the concept of the adipose tissue vasculature as a source of new targets for metabolic disease therapies. This article is part of a Special Issue entitled: Modulation of Adipose Tissue in Health and Disease.
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Affiliation(s)
- Silvia Corvera
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, USA.
| | - Olga Gealekman
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, USA
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12
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Harcourt BE, Penfold SA, Forbes JM. Coming full circle in diabetes mellitus: from complications to initiation. Nat Rev Endocrinol 2013; 9:113-23. [PMID: 23296171 DOI: 10.1038/nrendo.2012.236] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Glycaemic control, reduction of blood pressure using agents that block the renin-angiotensin system and control of dyslipidaemia are the major strategies used in the clinical management of patients with diabetes mellitus. Each of these approaches interrupts a number of pathological pathways, which directly contributes to the vascular complications of diabetes mellitus, including renal disease, blindness, neuropathy and cardiovascular disease. However, research published over the past few years has indicated that many of the pathological pathways important in the development of the vascular complications of diabetes mellitus are equally relevant to the initiation of diabetes mellitus itself. These pathways include insulin signalling, generation of cellular energy, post-translational modifications and redox imbalances. This Review will examine how the development of diabetes mellitus has come full circle from initiation to complications and suggests that the development of diabetes mellitus and the progression to chronic complications both require the same mechanistic triggers.
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Affiliation(s)
- Brooke E Harcourt
- Glycation and Diabetes Complications, Mater Medical Research Institute, Raymond Terrace, South Brisbane, QLD, Australia
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13
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He Z, Zhu HH, Bauler TJ, Wang J, Ciaraldi T, Alderson N, Li S, Raquil MA, Ji K, Wang S, Shao J, Henry RR, King PD, Feng GS. Nonreceptor tyrosine phosphatase Shp2 promotes adipogenesis through inhibition of p38 MAP kinase. Proc Natl Acad Sci U S A 2013; 110:E79-88. [PMID: 23236157 PMCID: PMC3538237 DOI: 10.1073/pnas.1213000110] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The molecular mechanism underlying adipogenesis and the physiological functions of adipose tissue are not fully understood. We describe here a unique mouse model of severe lipodystrophy. Ablation of Ptpn11/Shp2 in adipocytes, mediated by aP2-Cre, led to premature death, lack of white fat, low blood pressure, compensatory erythrocytosis, and hepatic steatosis in Shp2(fat-/-) mice. Fat transplantation partially rescued the lifespan and blood pressure in Shp2(fat-/-) mice, and administration of leptin also restored partially the blood pressure of mutant animals with endogenous leptin deficiency. Consistently, homozygous deletion of Shp2 inhibited adipocyte differentiation from embryonic stem (ES) cells. Biochemical analyses suggest a Shp2-TAO2-p38-p300-PPARγ pathway in adipogenesis, in which Shp2 suppresses p38 activation, leading to stabilization of p300 and enhanced PPARγ expression. Inhibition of p38 restored adipocyte differentiation from Shp2(-/-) ES cells, and p38 signaling is also suppressed in obese patients and obese animals. These results illustrate an essential role of adipose tissue in mammalian survival and physiology and also suggest a common signaling mechanism involved in adipogenesis and obesity development.
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Affiliation(s)
- Zhao He
- Department of Pathology and Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0864
| | - Helen H. Zhu
- Department of Pathology and Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0864
| | - Timothy J. Bauler
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI 48109-5620; and
| | - Jing Wang
- Department of Pathology and Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0864
| | - Theodore Ciaraldi
- Veteran’s Administration San Diego Healthcare System and Department of Medicine, and
| | - Nazilla Alderson
- Department of Pathology and Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0864
| | - Shuangwei Li
- Department of Pathology and Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0864
| | - Marie-Astrid Raquil
- Department of Pathology and Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0864
| | - Kaihong Ji
- Department of Pathology and Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0864
| | - Shufen Wang
- Department of Pathology and Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0864
| | - Jianhua Shao
- Department of Pediatrics, University of California at San Diego, La Jolla,CA 92093
| | - Robert R. Henry
- Veteran’s Administration San Diego Healthcare System and Department of Medicine, and
| | - Philip D. King
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI 48109-5620; and
| | - Gen-Sheng Feng
- Department of Pathology and Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0864
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14
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Abstract
Diabetes is a major worldwide problem. Despite some progress in the development of new antidiabetic agents, the ability to maintain tight glycemic control in order to prevent renal, retinal, and neuropathic complications of diabetes without adverse complications still remains a challenge. Recent evidence suggests, however, that in addition to playing a key role in the regulation of energy homeostasis, the adiposity hormone leptin also plays an important role in the control of glucose metabolism via its actions in the brain. This review examines the role of leptin action in the central nervous system and the mechanisms whereby leptin mediates its effects to regulate glucose metabolism. These findings suggest that defects or dysfunction in leptin signaling may contribute to the etiology of diabetes and raise the possibility that either leptin or downstream targets of leptin may have therapeutic potential for the treatment of diabetes.
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Affiliation(s)
- Thomas H. Meek
- Diabetes and Obesity Center of Excellence, Department of Medicine, University of Washington, Seattle, WA, USA
| | - Gregory J. Morton
- Diabetes and Obesity Center of Excellence, Department of Medicine, University of Washington, Seattle, WA, USA
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15
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Lehr S, Hartwig S, Sell H. Adipokines: a treasure trove for the discovery of biomarkers for metabolic disorders. Proteomics Clin Appl 2011; 6:91-101. [PMID: 22213627 DOI: 10.1002/prca.201100052] [Citation(s) in RCA: 223] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Revised: 09/12/2011] [Accepted: 09/13/2011] [Indexed: 01/04/2023]
Abstract
Adipose tissue is a major endocrine organ, releasing signaling and mediator proteins, termed adipokines, via which adipose tissue communicates with other organs. Expansion of adipose tissue in obesity alters adipokine secretion which may contribute to the development of metabolic diseases. Consequently, this correlation has emphasized the importance to further characterize the adipocyte secretion profile, and several attempts have been made to characterize the complex nature of the adipose tissue secretome by utilizing diverse proteomic profiling approaches. Although the entirety of human adipokines is still incompletely characterized, to date more than 600 potentially secretory proteins were identified providing a rich source to identify putative novel biomarkers associated with metabolic diseases.
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Affiliation(s)
- Stefan Lehr
- Institute of Clinical Biochemistry and Pathobiochemistry, German Diabetes Center, Duesseldorf, Germany.
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16
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Anderson JL, Carten JD, Farber SA. Zebrafish lipid metabolism: from mediating early patterning to the metabolism of dietary fat and cholesterol. Methods Cell Biol 2011; 101:111-41. [PMID: 21550441 DOI: 10.1016/b978-0-12-387036-0.00005-0] [Citation(s) in RCA: 130] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Lipids serve essential functions in cells as signaling molecules, membrane components, and sources of energy. Defects in lipid metabolism are implicated in a number of pandemic human diseases, including diabetes, obesity, and hypercholesterolemia. Many aspects of how fatty acids and cholesterol are absorbed and processed by intestinal cells remain unclear and present a hurdle to developing approaches for disease prevention and treatment. Numerous studies have shown that the zebrafish is an excellent model for vertebrate lipid metabolism. In this chapter, we review studies that employ zebrafish to better understand lipid signaling and metabolism.
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Affiliation(s)
- Jennifer L Anderson
- Carnegie Institution for Science, Department of Embryology, Baltimore, Maryland, USA
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17
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Cho KW, Lee OH, Banz WJ, Moustaid-Moussa N, Shay NF, Kim YC. Daidzein and the daidzein metabolite, equol, enhance adipocyte differentiation and PPARγ transcriptional activity. J Nutr Biochem 2010; 21:841-7. [DOI: 10.1016/j.jnutbio.2009.06.012] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2008] [Revised: 03/20/2009] [Accepted: 06/23/2009] [Indexed: 10/20/2022]
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18
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Zhang Y. Utility of transplantation in studying adipocyte biogenesis and function. Mol Cell Endocrinol 2010; 318:15-23. [PMID: 19733623 PMCID: PMC2826534 DOI: 10.1016/j.mce.2009.08.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2009] [Revised: 08/27/2009] [Accepted: 08/30/2009] [Indexed: 10/20/2022]
Abstract
Adipose tissue plays important roles in the regulation of energy homeostasis and metabolism. Two features distinguish adipose tissue from other organs--the ability to greatly expand its mass, via increases in cell size and/or number, and the wide anatomical distribution. While adipose tissue function is greatly affected by adipocyte size and anatomic location, regulations of adipocyte size, number, and body fat distribution are poorly understood. Transplantation of either mature adipose tissue or adipocyte progenitor cells has been used in studying adipocyte function and biogenesis. In this review, we will attempt to summarize methodological considerations for transplantation, including selections of donor material, transplantation site and the length of transplantation study, as well as effects of these factors and vascularization and innervation on the function of transplants. Specific studies are also reviewed to illustrate the utility of adipose tissue transplants in studying adipose tissue function and biogenesis. The focus is on studies in three areas: (1) use of transplants in demonstrating adipose tissue function, such as effects of adipose tissue transplants on metabolism and energy homeostasis of the recipient animals and depot-specific differences in adipose tissue function; (2) use of transplantation to dissect direct or cell-autonomous from indirect or non-cell-autonomous effects of leptin signaling and sex on adipocyte size; (3) use of transplantation in the identification of adipocyte progenitor cells and lineage analysis. Finally, future applications of transplantation in studying depot-specific adipocyte biogenesis, and genetic and hormonal effects of sex and age on adipocyte biogenesis and function are discussed.
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Affiliation(s)
- Yiying Zhang
- Division of Molecular Genetics, Department of Pediatrics, Columbia University, New York, NY 10032, USA.
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19
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Carten JD, Farber SA. A new model system swims into focus: using the zebrafish to visualize intestinal metabolism in vivo. ACTA ACUST UNITED AC 2009; 4:501-515. [PMID: 20174460 DOI: 10.2217/clp.09.40] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Many fundamental questions remain regarding the cellular and molecular mechanisms of digestive lipid metabolism. One major impediment to answering important questions in the field has been the lack of a tractable and sufficiently complex model system. Until recently, most studies of lipid metabolism have been performed in vitro or in mice, yet each approach possesses certain limitations. The zebrafish (Danio rerio) offers an excellent model system in which to study lipid metabolism in vivo, owing to its small size, genetic tractability and optical clarity. Fluorescent lipid dyes and optical reporters of lipid-modifying enzymes are now being used in live zebrafish to generate visible readouts of digestive physiology. Here we review recent advances in visualizing intestinal lipid metabolism in live larval zebrafish.
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20
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Ukropec J, Ukropcova B, Kurdiova T, Gasperikova D, Klimes I. Adipose tissue and skeletal muscle plasticity modulates metabolic health. Arch Physiol Biochem 2008; 114:357-68. [PMID: 19016045 DOI: 10.1080/13813450802535812] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Obesity, accumulation of adipose tissue, develops when energy intake exceeds energy expenditure. Adipose tissue is essential for buffering the differences between energy intake and expenditure by accumulating lipids while skeletal muscle is the energy burning machine. Here we adopted the concept that (i) adipose tissue ability to regulate the storage capacity for lipids as well as (ii) dynamic regulation of muscle and adipose tissue secretory and metabolic activity is important for maintaining the metabolic health. This might be at least in part related to tissue plasticity, a phenomenon enabling dynamic modulation of the tissue phenotype in different physiological and pathophysiological situations. Recent advances in our understanding of the complex endocrine function of adipose tissue in regulating lipid metabolism, adipogenesis, angiogenesis, extracellular matrix remodelling, inflammation and oxidative stress prompted us to review the role of tissue plasticity--dynamic changes in adipose tissue and skeletal muscle metabolic and endocrine phenotype--in determining the difference between metabolic health and disease.
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Affiliation(s)
- Jozef Ukropec
- Institute of Experimental Endocrinology, Slovak Academy of Sciences, Bratislava, Slovak Republic.
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21
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Sell H, Dietze-Schroeder D, Eckel J. The adipocyte-myocyte axis in insulin resistance. Trends Endocrinol Metab 2006; 17:416-22. [PMID: 17084639 DOI: 10.1016/j.tem.2006.10.010] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2006] [Revised: 10/13/2006] [Accepted: 10/24/2006] [Indexed: 12/16/2022]
Abstract
Insulin resistance in skeletal muscle is linked to an elevated adipose tissue mass, as is found in obesity, but can also be observed in lipodystrophy, in which adipose tissue is greatly reduced. Adipose tissue releases endocrine and metabolic mediators and is actively involved in crosstalk with skeletal muscle, a process that precedes and underlies the development of insulin resistance in muscles. Adipokines including tumor necrosis factor alpha, interleukin-6, leptin and adiponectin influence insulin signaling in skeletal muscle. Free fatty acids, their metabolites and ectopic fat in muscle also contribute to insulin resistance. Recent research indicates inflammation, endoplasmic reticulum stress and oxidative stress could be underlying mechanisms at the center of the development of insulin resistance. Insights into the role of macrophages in adipose tissue add to the complicated interplay between adipose tissue and skeletal muscle.
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Affiliation(s)
- Henrike Sell
- Institute of Clinical Biochemistry and Pathobiochemistry, German Diabetes Center, Düsseldorf, Germany
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22
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Ho SY, Lorent K, Pack M, Farber SA. Zebrafish fat-free is required for intestinal lipid absorption and Golgi apparatus structure. Cell Metab 2006; 3:289-300. [PMID: 16581006 PMCID: PMC2247414 DOI: 10.1016/j.cmet.2006.03.001] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2005] [Revised: 12/15/2005] [Accepted: 03/01/2006] [Indexed: 01/25/2023]
Abstract
The zebrafish fat-free (ffr) mutation was identified in a physiological screen for genes that regulate lipid metabolism. ffr mutant larvae are morphologically indistinguishable from wild-type sibling larvae, but their absorption of fluorescent lipids is severely impaired. Through positional cloning, we have identified a causative mutation in a highly conserved and ubiquitously expressed gene within the ffr locus. The Ffr protein contains a Dor-1 like domain typical of oligomeric Golgi complex (COG) gene, cog8. Golgi complex ultrastructure is disrupted in the ffr digestive tract. Consistent with a possible role in COG-mediated Golgi function, wild-type Ffr-GFP and COG8-mRFP fusion proteins partially colocalize in zebrafish blastomeres. Enterocyte retention of an endosomal lipid marker in ffr larvae support the idea that altered vesicle trafficking contributes to the ffr mutant defect. These data indicate that ffr is required for both Golgi structure and vesicular trafficking, and ultimately lipid transport.
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Affiliation(s)
- Shiu-Ying Ho
- Department of Microbiology and Immunology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
- Department of Biochemistry and Molecular Biology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Kristin Lorent
- Department of Medicine, and Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Michael Pack
- Department of Medicine, and Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104
- *Correspondence: (M.P.); (S.A.F.)
| | - Steven A. Farber
- Department of Microbiology and Immunology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
- Department of Embryology, Carnegie Institution of Washington, Baltimore, Maryland 21218
- *Correspondence: (M.P.); (S.A.F.)
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23
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Klöting N, Blüher M, Klöting I. The polygenetically inherited metabolic syndrome of WOKW rats is associated with insulin resistance and altered gene expression in adipose tissue. Diabetes Metab Res Rev 2006; 22:146-54. [PMID: 16041833 DOI: 10.1002/dmrr.582] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND Wistar Ottawa Karlsburg W (RT1u) rats (WOKW) develop a complete metabolic syndrome closely resembling the human disease. The aim of this study was to characterize the phenotype of adipose tissue in WOKW rats with regard to adipocyte metabolism, insulin resistance, and gene expression and thus to define the phenotype more precisely. METHODS Glucose metabolism, insulin sensitivity, and gene expression of key adipocyte genes, including adiponectin, interleukin 6 (Il6), 11 beta-hydroxysteroid dehydrogenase (11beta Hsd), peroxisome proliferator-activated receptor gamma (Ppar gamma), forkhead box O1 (Foxo1), glucose transporter 4 (Glut4), CCAAT/enhancer binding protein (C/ebp alpha), and fatty acid synthase (Fasn) were characterized in adipocytes from epididymal and subcutaneous fat depots of 28-week-old male WOKW rats and Dark Agouti (DA) controls. RESULTS WOKW rats display decreased insulin-stimulated glucose uptake and decreased insulin sensitivity during lipogenesis and lipolysis in isolated adipocytes. The severe insulin resistance predominantly in epididymal adipose tissue of WOKW rats is associated with a 10-fold decrease in adipocyte adiponectin gene expression, decreased Ppar gamma, but increased Foxo1 gene expression compared to DA rats. CONCLUSIONS Insulin resistance in adipose tissue is associated with altered adipocyte gene expression in WOKW rats, additionally completing the picture of the metabolic syndrome in this animal model. This fact not only qualifies the WOKW rat for further detailed analysis of genetic determinants of metabolic syndrome but also highlights its suitability for pharmacological research.
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Affiliation(s)
- Nora Klöting
- Department of Laboratory Animal Science, Medical Faculty, University of Greifswald, Karlsburg, Germany
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24
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Abstract
Recent evidence suggests a key role for the brain in the control of both body fat content and glucose metabolism. Neuronal systems that regulate energy intake, energy expenditure, and endogenous glucose production sense and respond to input from hormonal and nutrient-related signals that convey information regarding both body energy stores and current energy availability. In response to this input, adaptive changes occur that promote energy homeostasis and the maintenance of blood glucose levels in the normal range. Defects in this control system are implicated in the link between obesity and type 2 diabetes.
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Affiliation(s)
- Michael W Schwartz
- Division of Metabolism, Endocrinology and Nutrition, University of Washington, Seattle, WA 98110, USA.
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25
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Blüher M, Patti ME, Gesta S, Kahn BB, Kahn CR. Intrinsic heterogeneity in adipose tissue of fat-specific insulin receptor knock-out mice is associated with differences in patterns of gene expression. J Biol Chem 2004; 279:31891-901. [PMID: 15131119 DOI: 10.1074/jbc.m404569200] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mice with a fat-specific insulin receptor knock-out (FIRKO) have reduced adipose tissue mass, are protected against obesity, and have an extended life span. White adipose tissue of FIRKO mice is also characterized by a polarization into two major populations of adipocytes, one small (<50 microm) and one large (>100 microm), which differ with regard to basal triglyceride synthesis and lipolysis, as well as in the expression of fatty acid synthase, sterol regulatory element-binding protein 1c, and CCAAT/enhancer-binding protein alpha (C/EBP-alpha). Gene expression analysis using RNA isolated from large and small adipocytes of FIRKO and control (IR lox/lox) mice was performed on oligonucleotide microarrays. Of the 12,488 genes/expressed sequence tags represented, 111 genes were expressed differentially in the four populations of adipocytes at the p < 0.001 level. These alterations exhibited 10 defined patterns and occurred in response to two distinct regulatory effects. 63 genes were identified as changed in expression depending primarily upon adipocyte size, including C/EBP-alpha, C/EBP-delta, superoxide dismutase 3, and the platelet-derived growth factor receptor. 48 genes were regulated primarily by impairment of insulin signaling, including transforming growth factor beta, interferon gamma, insulin-like growth factor I receptor, activating transcription factor 3, aldehyde dehydrogenase 2, and protein kinase Cdelta. These data suggest an intrinsic heterogeneity of adipocytes with differences in gene expression related to adipocyte size and insulin signaling.
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Affiliation(s)
- Matthias Blüher
- Joslin Diabetes Center and Department of Medicine, Harvard Medical School, Boston, Massachusetts 02215, USA
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Abstract
Forward genetics is an unbiased methodology to discover new genes or functions of genes. At the present, the zebrafish is one of the few vertebrate systems where large-scale forward genetic studies are practical. Fluorescent lipid labeling of zebrafish larvae derived from families created from ENU-mutagenized fish enabled us to perform a large scale in vivo screen to identify mutants with perturbed lipid processing. With the aid of the zebrafish genome project, positional cloning of mutated genes with abnormal lipid metabolism can be accelerated. MO- and gripNA-based transient gene silencing is feasible in zebrafish embryos and provides a reverse genetic screening strategy to search for important lipid regulators. The advantages of using zebrafish as a vertebrate model to study lipid metabolism include its rapid external development and its optical clarity that enables the monitoring of biological processes. Large scale, high-throughput drug screening in vivo, especially for drugs that inhibit lipid absorption, can be easily achieved in this model. These zebrafish-based assays are important tools to understand aspects of lipid biology with significant clinical implications.
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Affiliation(s)
- Shiu-Ying Ho
- Department of Microbiology and Immunology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
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27
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Blüher M, Michael MD, Peroni OD, Ueki K, Carter N, Kahn BB, Kahn CR. Adipose tissue selective insulin receptor knockout protects against obesity and obesity-related glucose intolerance. Dev Cell 2002; 3:25-38. [PMID: 12110165 DOI: 10.1016/s1534-5807(02)00199-5] [Citation(s) in RCA: 625] [Impact Index Per Article: 28.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Insulin signaling in adipose tissue plays an important role in lipid storage and regulation of glucose homeostasis. Using the Cre-loxP system, we created mice with fat-specific disruption of the insulin receptor gene (FIRKO mice). These mice have low fat mass, loss of the normal relationship between plasma leptin and body weight, and are protected against age-related and hypothalamic lesion-induced obesity, and obesity-related glucose intolerance. FIRKO mice also exhibit polarization of adipocytes into populations of large and small cells, which differ in expression of fatty acid synthase, C/EBP alpha, and SREBP-1. Thus, insulin signaling in adipocytes is critical for development of obesity and its associated metabolic abnormalities, and abrogation of insulin signaling in fat unmasks a heterogeneity in adipocyte response in terms of gene expression and triglyceride storage.
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Affiliation(s)
- Matthias Blüher
- Joslin Diabetes Center and Department of Medicine, Harvard Medical School, Boston, MA 02215, USA
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28
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García-Viejo MA, Ruíz M, Martínez E. Strategies for treating HIV-related lipodystrophy. Expert Opin Investig Drugs 2001; 10:1443-56. [PMID: 11772261 DOI: 10.1517/13543784.10.8.1443] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
HIV-related lipodystrophy has emerged as one of the most prevalent problems for patients with HIV, since this infection can now be seen as a chronic disease. Despite its growing importance, crucial issues such as aetiopathogenesis, diagnosis, prevention and therapy remain largely unknown and unexplored. Current evidence suggests that aetiology is multifactorial. HIV infection, antiretroviral therapy and patient-related factors probably all contribute to the development of lipodystrophy. The lack of a formal definition and the nature of wasting syndromes that affect HIV-infected patients can hinder the diagnosis and treatment of lipodystrophy. Body fat changes have a major negative impact on the quality of life of patients. Metabolic abnormalities are also well known cardiovascular risk factors that can increase the morbidity and mortality due to cardiovascular disorders in a relatively young population. As yet, we do not know whether lipodystrophy is preventable or reversible. Several therapeutic approaches have been tested with limited success, however potential complications must be considered. These therapeutic approaches include general health measures (diet, exercise and discontinuation of smoking), switching antiretrovirals (from protease inhibitors to non-nucleoside reverse transcriptase inhibitors or abacavir, or from stavudine to other nucleoside reverse transcriptase inhibitors) and use of drugs with metabolic effects (metformin, thiazolidinediones, recombinant growth hormone and anabolic steroids). A judicious use of available data, and opting for an individualised approach seems the best option for management of this problem at present.
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Affiliation(s)
- M A García-Viejo
- Infectious Diseases Unit, Clinical Institute of Infectious Diseases and Immunology, IDIBAPS-Hospital Clinic University, C/Villarroel, 170, E-08036-Barcelona, Spain
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