1
|
Wojciechowicz T, Szczepankiewicz D, Strowski MZ, Nowak KW, Skrzypski M. Neuropeptide B promotes differentiation of rodent white preadipocytes into mature adipocytes. Mol Cell Endocrinol 2023; 562:111850. [PMID: 36623583 DOI: 10.1016/j.mce.2023.111850] [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: 09/07/2022] [Revised: 11/25/2022] [Accepted: 01/04/2023] [Indexed: 01/09/2023]
Abstract
Neuropeptide B (NPB) modulates energy homeostasis and metabolism through activation of NPBWR1 and NPBWR2 in humans and NPBWR1 in rodents. Recently, we reported that NPB promotes adipogenesis in rat brown preadipocytes. In the present study, we evaluated the effects of NPB on proliferation and differentiation into mature adipocytes of white rat preadipocytes and 3T3-L1 cells. We found the expression of NPBWR1 and NPB on mRNA and protein level in rat white preadipocytes and 3T3-L1 cells. NPB increased expression of mRNA and protein production of adipogenic genes (PPARγ, C/EBPβ, CEBPα and FABP4) in rat preadipocytes and 3T3-L1 cells during the differentiation process. Furthermore, NPB stimulated lipid accumulation in rat preadipocytes and 3T3-L1 cells. In addition, we found that NPB promotes phosphorylation of p38 kinase in rat preadipocytes and 3T3-L1 cells. NPB failed to stimulate expression of proadipogenic genes in the presence of p38 inhibitor. NPB failed to modulate viability and proliferation of rat preadipocytes and 3T3-L1 cells. Taken together, we report that NPB promotes differentiation of rodent preadipocytes via p38-dependent mechanism. NPB does not modulate viability and proliferation of rat preadipocytes and 3T3-L1 cells.
Collapse
Affiliation(s)
- T Wojciechowicz
- Department of Animal Physiology, Biochemistry and Biostructure, Poznan University of Life Sciences, 60-637, Poznań, Poland.
| | - D Szczepankiewicz
- Department of Animal Physiology, Biochemistry and Biostructure, Poznan University of Life Sciences, 60-637, Poznań, Poland
| | - M Z Strowski
- Department of Hepatology and Gastroenterology, Charité-University Medicine Berlin, 13353, Berlin, Germany; Medical Clinic III, 15236, Frankfurt (Oder), Germany
| | - K W Nowak
- Department of Animal Physiology, Biochemistry and Biostructure, Poznan University of Life Sciences, 60-637, Poznań, Poland
| | - M Skrzypski
- Department of Animal Physiology, Biochemistry and Biostructure, Poznan University of Life Sciences, 60-637, Poznań, Poland
| |
Collapse
|
2
|
Mizusawa N, Harada N, Iwata T, Ohigashi I, Itakura M, Yoshimoto K. Identification of protease serine S1 family member 53 as a mitochondrial protein in murine islet beta cells. Islets 2022; 14:1-13. [PMID: 34636707 PMCID: PMC8812782 DOI: 10.1080/19382014.2021.1982325] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The aim of this study was to identify genes that are specifically expressed in pancreatic islet β-cells (hereafter referred to as β-cells). Large-scale complementary DNA-sequencing analysis was performed for 3,429 expressed sequence tags derived from murine MIN6 β-cells, through homology comparisons using the GenBank database. Three individual ESTs were found to code for protease serine S1 family member 53 (Prss53). Prss53 mRNA is processed into both a short and long form, which encode 482 and 552 amino acids, respectively. Transient overexpression of myc-tagged Prss53 in COS-7 cells showed that Prss53 was strongly associated with the luminal surfaces of organellar membranes and that it underwent signal peptide cleavage and N-glycosylation. Immunoelectron microscopy and western blotting revealed that Prss53 localized to mitochondria in MIN6 cells. Short hairpin RNA-mediated Prss53 knockdown resulted in Ppargc1a downregulation and Ucp2 and Glut2 upregulation. JC-1 staining revealed that the mitochondria were depolarized in Prss53-knockdown MIN6 cells; however, no change was observed in glucose-stimulated insulin secretion. Our results suggest that mitochondrial Prss53 expression plays an important role in maintaining the health of β-cells.
Collapse
Affiliation(s)
- Noriko Mizusawa
- Department of Medical Pharmacology, Institute of Biomedical Sciences, Tokushima University, Tokushima, Japan
- CONTACT Noriko Mizusawa Department of Oral Bioscience, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-Kuramoto-cho, Tokushima City770-8504, Japan
| | - Nagakatsu Harada
- Department of Health and Nutrition, Faculty of Nursing and Nutrition, The University of Shimane, Shimane, Japan
| | - Takeo Iwata
- Department of Functional Morphology, Faculty of Pharmaceutical Sciences, Niigata University of Pharmacy and Applied Life Sciences, Niigata, Japan
| | - Izumi Ohigashi
- Division of Experimental Immunology, Institute of Advanced Medical Sciences, Tokushima University, Tokushima, Japan
| | - Mitsuo Itakura
- Division of Genetic Information, Institute for Genome Research, Tokushima University, Tokushima, Japan
| | - Katsuhiko Yoshimoto
- Department of Medical Pharmacology, Institute of Biomedical Sciences, Tokushima University, Tokushima, Japan
| |
Collapse
|
3
|
Kodde A, Engels E, Oosting A, van Limpt K, van der Beek EM, Keijer J. Maturation of White Adipose Tissue Function in C57BL/6j Mice From Weaning to Young Adulthood. Front Physiol 2019; 10:836. [PMID: 31354508 PMCID: PMC6629938 DOI: 10.3389/fphys.2019.00836] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 06/17/2019] [Indexed: 01/13/2023] Open
Abstract
White adipose tissue (WAT) distribution and WAT mitochondrial function contribute to total body metabolic health throughout life. Nutritional interventions starting in the postweaning period may impact later life WAT health and function. We therefore assessed changes in mitochondrial density and function markers in WAT depots of young mice. Inguinal (ING), epididymal (EPI) and retroperitoneal (RP) WAT of 21, 42 and 98 days old C57BL/6j mice was collected. Mitochondrial density [citrate synthase (CS), mtDNA] and function [subunits of oxidative phosphorylation complexes (OXPHOS)] markers were analyzed, together with gene expression of browning markers (Ucp1, Cidea). mRNA of ING WAT of 21 and 98 old mice was sequenced to further investigate functional changes of the mitochondria and alterations in cell populations. CS levels decreased significantly over time in all depots. ING showed most pronounced changes, including significantly decreased levels of OXPHOS complex I, II, and III subunits and gene expression of Ucp1 (PN21-42 and PN42-98) and Cidea (PN42-98). White adipocyte markers were higher at PN98 in ING WAT. Analyses of RNA sequence data showed that the mitochondrial functional profile changed over time from “growth-supporting” mitochondria focused on ATP production (and dissipation), to more steady-state mitochondria with more diverse functions and higher biosynthesis. Mitochondrial density and energy metabolism markers declined in all three depots over time after weaning. This was most pronounced in ING WAT and associated with reduced browning markers, increased whitening and an altered metabolism. In particular the PN21-42 period may provide a time window to study mitochondrial adaptation and effects of nutritional exposures relevant for later life metabolic health.
Collapse
Affiliation(s)
| | | | | | | | - Eline M van der Beek
- Danone Nutricia Research, Utrecht, Netherlands.,Department of Pediatrics, University Medical Center Groningen - University of Groningen, Groningen, Netherlands
| | - Jaap Keijer
- Human and Animal Physiology, Wageningen University, Wageningen, Netherlands
| |
Collapse
|
4
|
El-Shehawi AM, Elseehy MM. Gene Expression Profiling during Life Cycle of Potato (Solanum tuberosum) Tubers by Microarray. CYTOL GENET+ 2019. [DOI: 10.3103/s009545271901002x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
5
|
Jastroch M, Oelkrug R, Keipert S. Insights into brown adipose tissue evolution and function from non-model organisms. ACTA ACUST UNITED AC 2018. [PMID: 29514888 DOI: 10.1242/jeb.169425] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Brown adipose tissue (BAT) enables adaptive thermoregulation through heat production that is catalyzed by mitochondrial uncoupling protein 1 (UCP1). BAT is frequently studied in rodent model organisms, and recently in adult humans to treat metabolic diseases. However, complementary studies of many non-model species, which have diversified to many more ecological niches, may significantly broaden our understanding of BAT regulation and its physiological roles. This Review highlights the research on non-model organisms, which was instrumental to the discovery of BAT function, and the unique evolutionary history of BAT/UCP1 in mammalian thermogenesis. The comparative biology of BAT provides a powerful integrative approach that could identify conserved and specialized functional changes in BAT and UCP1 by considering species diversity, ecology and evolution, and by fusing multiple scientific disciplines such as physiology and biochemistry. Thus, resolving the complete picture of BAT biology may fail if comparative studies of non-model organisms are neglected.
Collapse
Affiliation(s)
- Martin Jastroch
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center at Helmholtz Zentrum München, D-85764 Neuherberg, Germany .,German Center for Diabetes Research (DZD), D-85764 Neuherberg, Germany.,Department of Animal Physiology, Faculty of Biology, Philipps University of Marburg, D-35032 Marburg, Germany
| | - Rebecca Oelkrug
- Department of Molecular Endocrinology, Center of Brain, Behavior and Metabolism (CBBM), University of Lübeck, D-23562 Lübeck, Germany
| | - Susanne Keipert
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center at Helmholtz Zentrum München, D-85764 Neuherberg, Germany.,German Center for Diabetes Research (DZD), D-85764 Neuherberg, Germany
| |
Collapse
|
6
|
Lombardi G, Sanchis-Gomar F, Perego S, Sansoni V, Banfi G. Implications of exercise-induced adipo-myokines in bone metabolism. Endocrine 2016; 54:284-305. [PMID: 26718191 DOI: 10.1007/s12020-015-0834-0] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 12/14/2015] [Indexed: 12/12/2022]
Abstract
Physical inactivity has been recognized, by the World Health Organization as the fourth cause of death (5.5 % worldwide). On the contrary, physical activity (PA) has been associated with improved quality of life and decreased risk of several diseases (i.e., stroke, hypertension, myocardial infarction, obesity, malignancies). Bone turnover is profoundly affected from PA both directly (load degree is the key determinant for BMD) and indirectly through the activation of several endocrine axes. Several molecules, secreted by muscle (myokines) and adipose tissues (adipokines) in response to exercise, are involved in the fine regulation of bone metabolism in response to the energy availability. Furthermore, bone regulates energy metabolism by communicating its energetic needs thanks to osteocalcin which acts on pancreatic β-cells and adipocytes. The beneficial effects of exercise on bone metabolism depends on the intermittent exposure to myokines (i.e., irisin, IL-6, LIF, IGF-I) which, instead, act as inflammatory/pro-resorptive mediators when chronically elevated; on the other hand, the reduction in the circulating levels of adipokines (i.e., leptin, visfatin, adiponectin, resistin) sustains these effects as well as improves the whole-body metabolic status. The aim of this review is to highlight the newest findings about the exercise-dependent regulation of these molecules and their role in the fine regulation of bone metabolism.
Collapse
Affiliation(s)
- Giovanni Lombardi
- Laboratory of Experimental Biochemistry & Molecular Biology, I.R.C.C.S. Istituto Ortopedico Galeazzi, Via Riccardo Galeazzi 4, 20161, Milan, Italy.
| | | | - Silvia Perego
- Laboratory of Experimental Biochemistry & Molecular Biology, I.R.C.C.S. Istituto Ortopedico Galeazzi, Via Riccardo Galeazzi 4, 20161, Milan, Italy
| | - Veronica Sansoni
- Laboratory of Experimental Biochemistry & Molecular Biology, I.R.C.C.S. Istituto Ortopedico Galeazzi, Via Riccardo Galeazzi 4, 20161, Milan, Italy
| | - Giuseppe Banfi
- Laboratory of Experimental Biochemistry & Molecular Biology, I.R.C.C.S. Istituto Ortopedico Galeazzi, Via Riccardo Galeazzi 4, 20161, Milan, Italy
- Vita-Salute San Raffaele University, Milan, Italy
| |
Collapse
|
7
|
Gu N, You L, Shi C, Yang L, Pang L, Cui X, Ji C, Zheng W, Guo X. Expression of miR-199a-3p in human adipocytes is regulated by free fatty acids and adipokines. Mol Med Rep 2016; 14:1180-6. [PMID: 27279151 PMCID: PMC4940088 DOI: 10.3892/mmr.2016.5379] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 05/17/2016] [Indexed: 01/14/2023] Open
Abstract
Obesity is associated with a notable risk for disease, including risk of cardiovascular disorders, type 2 diabetes mellitus (T2DM) and hypertension. Adipose tissue modulates the metabolism by releasing free fatty acids (FFAs) and adipokines, including leptin, resistin, tumor necrosis factor-α (TNF-α) and interleukin 6 (IL-6). Altered secretion patterns of FFAs and adipokines have been demonstrated to result in obesity-associated insulin resistance (IR) and inflammatory responses. MicroRNA-199a-3p (miR)-199a-3p expression is significantly induced in differentiated human adipose-derived mesenchymal stem cells and indicates the association with T2DM. However, the association between miR-199a-3p levels in adipocytes and obesity-associated IR, as well as inflammatory responses remains to be elucidated. The present study observed an elevation of miR-199a-3p expression level in mature human adipocytes (visceral) compared with pre-adipocytes. In addition, miR-199a-3p expression was higher in visceral adipose deposits from obese subjects. FFA, TNF-α, IL-6 and leptin significantly induced miR-199a-3p expression in mature human adipocytes, while resistin had the opposite effect. miR-199a-3p may represent a factor in the modulation of obesity-associated IR and inflammatory responses.
Collapse
Affiliation(s)
- Nan Gu
- Nanjing Maternity and Child Health Care Institute, Nanjing Maternity and Child Health Care Hospital Affiliated With Nanjing Medical University, Nanjing, Jiangsu 210004, P.R. China
| | - Lianghui You
- Nanjing Maternity and Child Health Care Institute, Nanjing Maternity and Child Health Care Hospital Affiliated With Nanjing Medical University, Nanjing, Jiangsu 210004, P.R. China
| | - Chunmei Shi
- Nanjing Maternity and Child Health Care Institute, Nanjing Maternity and Child Health Care Hospital Affiliated With Nanjing Medical University, Nanjing, Jiangsu 210004, P.R. China
| | - Lei Yang
- Nanjing Maternity and Child Health Care Institute, Nanjing Maternity and Child Health Care Hospital Affiliated With Nanjing Medical University, Nanjing, Jiangsu 210004, P.R. China
| | - Lingxia Pang
- Nanjing Maternity and Child Health Care Institute, Nanjing Maternity and Child Health Care Hospital Affiliated With Nanjing Medical University, Nanjing, Jiangsu 210004, P.R. China
| | - Xianwei Cui
- Nanjing Maternity and Child Health Care Institute, Nanjing Maternity and Child Health Care Hospital Affiliated With Nanjing Medical University, Nanjing, Jiangsu 210004, P.R. China
| | - Chenbo Ji
- Nanjing Maternity and Child Health Care Institute, Nanjing Maternity and Child Health Care Hospital Affiliated With Nanjing Medical University, Nanjing, Jiangsu 210004, P.R. China
| | - Wen Zheng
- Maternity and Child Health Hospital of Yancheng, Yancheng, Jiangsu 224002, P.R. China
| | - Xirong Guo
- Nanjing Maternity and Child Health Care Institute, Nanjing Maternity and Child Health Care Hospital Affiliated With Nanjing Medical University, Nanjing, Jiangsu 210004, P.R. China
| |
Collapse
|
8
|
García-Ortega LF, Martínez O. How Many Genes Are Expressed in a Transcriptome? Estimation and Results for RNA-Seq. PLoS One 2015; 10:e0130262. [PMID: 26107654 PMCID: PMC4479379 DOI: 10.1371/journal.pone.0130262] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 05/19/2015] [Indexed: 01/02/2023] Open
Abstract
RNA-seq experiments estimate the number of genes expressed in a transcriptome as well as their relative frequencies. However, an undetermined number of genes can remain undetected due to their low expression relative to the sample size (sequence depth). Estimation of the true number of genes expressed in a transcriptome is essential in order to determine which genes are exclusively expressed in specific tissues or under particular conditions. A reliable estimate of the true number of expressed genes is also required to accurately measure transcriptome changes and to predict the sequencing depth needed to increase the proportion of detected genes. This problem is analogous to ecological sampling problems such as estimating the number of species at a given site. Here we present a non-parametric estimator for the number of undetected genes as well as for the extra sample size needed to detect a given proportion of the undetected genes. Our estimators are superior to ones already published by having smaller standard errors and biases. We applied our method to a set of 32 publicly available RNA-seq experiments, including the evaluation of 311 individually sequenced libraries. We found that in the majority of the cases more than one thousand genes are undetected, and that on average approximately 6% of the expressed genes per accession remain undetected. This figure increases to approximately 10% if individual sequencing libraries are analyzed. Our method is also applicable to metagenomic experiments. Using our method, the number of undetected genes as well as the sample size needed to detect them can be calculated, leading to more accurate and complete gene expression studies.
Collapse
Affiliation(s)
- Luis Fernando García-Ortega
- Laboratorio Nacional de Genómica para la Biodiversidad (Langebio), Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (Cinvestav-IPN), Irapuato, Guanajuato, México
| | - Octavio Martínez
- Laboratorio Nacional de Genómica para la Biodiversidad (Langebio), Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (Cinvestav-IPN), Irapuato, Guanajuato, México
| |
Collapse
|
9
|
Gender-dependent gene expressions in brown adipose tissue of lean and obese rats fed a high fat diet. BIOTECHNOL BIOPROC E 2012. [DOI: 10.1007/s12257-012-0332-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
10
|
Van Schothorst EM, Franssen-van Hal N, Schaap MM, Pennings J, Hoebee B, Keijer J. Adipose Gene Expression Patterns of Weight Gain Suggest Counteracting Steroid Hormone Synthesis. ACTA ACUST UNITED AC 2012; 13:1031-41. [PMID: 15976146 DOI: 10.1038/oby.2005.121] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
OBJECTIVE To identify early molecular changes in weight gain, using analysis of gene expression changes in adipose tissue of mice fed well-defined humanized (Western) high-fat and low-fat (control) diets during a short (3- to 5-week) time interval. RESEARCH METHODS AND PROCEDURES An adipose-enriched cDNA microarray was constructed and used for the expression analyses of visceral adipose tissues of wildtype young adult C57BL/6J male mice on different diets. RESULTS Mice on a high-fat diet had significantly higher body weight (at most, 9.6% greater) and adipose tissue weights compared with mice on a control diet. Gene expression analyses revealed 31 transcripts significantly differentially expressed in visceral adipose tissue between the diet groups. Most of these genes were expressed more on the high-fat diet. They mainly encode proteins involved in cellular structure (e.g., myosin, procollagen, vimentin) and lipid metabolism (e.g., leptin, lipoprotein lipase, carbonic anhydrase 3). This increase in gene expression was accompanied by a decrease in oxidative phosphorylation and carbohydrate metabolism (ATP citrate lyase). Importantly, genes belonging to steroid hormone biosynthesis (3beta-hydroxysteroid dehydrogenase-1, cholesterol side-chain cleavage cytochrome P450, and steroid-11beta-hydroxylase) were all expressed less in mice on a high-fat diet. DISCUSSION A short time period of 3 to 5 weeks of high-fat feeding altered gene expression patterns in visceral adipose tissue in male mice. Gene expression changes indicate initiation of adipose tissue enlargement and the down-regulation of adipose steroid hormone biosynthesis. The latter suggests a mechanism by which initial progression toward weight gain is counteracted.
Collapse
Affiliation(s)
- Evert M Van Schothorst
- Laboratory of Toxicology, Pathology, and Genetics, National Institute of Public Health and the Environment (RIVM), PO Box 1, 3720 BA Bilthoven, The Netherlands.
| | | | | | | | | | | |
Collapse
|
11
|
van Dijk JP, Cankar K, Hendriksen PJM, Beenen HG, Zhu M, Scheffer S, Shepherd LVT, Stewart D, Davies HV, Leifert C, Wilkockson SJ, Gruden K, Kok EJ. The identification and interpretation of differences in the transcriptomes of organically and conventionally grown potato tubers. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2012; 60:2090-2101. [PMID: 22300527 DOI: 10.1021/jf204696w] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
In the European integrated research project SAFEFOODS, one of the aims was to further establish the potential of transcriptomics for the assessment of differences between plant varieties grown under different environmental conditions. Making use of the knowledge of cellular processes and interactions is one of the ways to obtain a better understanding of the differences found with transcriptomics. For the present study the potato genotype Santé was grown under both organic and conventional fertilizer, and each combined with either organic or conventional crop protection, giving four different treatments. Samples were derived from the European project QualityLowInputFood (QLIF). Microarray data were analyzed using different statistical tools (multivariate, principal components analysis (PCA); univariate, analysis of variance (ANOVA)) and with pathway analysis (hypergeometric distribution (HGD) and gene set enrichment analysis (GSEA)). Several biological processes were implicated as a result of the different treatments of the plants. Most obvious were the lipoxygenase pathway, with higher expression in organic fertilizer and lower expression in organic crop protection; the starch synthase pathway, with higher expression in both organic crop protection and fertilizer; and the biotic stress pathway, with higher expression in organic fertilizer. This study confirmed that gene expression profiling in combination with pathway analysis can identify and characterize differences between plants grown under different environmental conditions.
Collapse
Affiliation(s)
- Jeroen P van Dijk
- RIKILT-Institute of Food Safety (Wageningen UR), Wageningen, The Netherlands.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Klingenspor M, Herzig S, Pfeifer A. Brown fat develops a brite future. Obes Facts 2012; 5:890-6. [PMID: 23296106 DOI: 10.1159/000346337] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Accepted: 12/10/2012] [Indexed: 01/02/2023] Open
|
13
|
Cypess AM, Zhang H, Schulz TJ, Huang TL, Espinoza DO, Kristiansen K, Unterman TG, Tseng YH. Insulin/IGF-I regulation of necdin and brown adipocyte differentiation via CREB- and FoxO1-associated pathways. Endocrinology 2011; 152:3680-9. [PMID: 21862615 PMCID: PMC3176640 DOI: 10.1210/en.2011-1229] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Brown adipose tissue plays an important role in obesity, insulin resistance, and diabetes. We have previously shown that the transition from brown preadipocytes to mature adipocytes is mediated in part by insulin receptor substrate (IRS)-1 and the cell cycle regulator protein necdin. In this study, we used pharmacological inhibitors and adenoviral dominant negative constructs to demonstrate that this transition involves IRS-1 activation of Ras and ERK1/2, resulting in phosphorylation of cAMP response element-binding protein (CREB) and suppression of necdin expression. This signaling did not include an elevation of intracellular calcium. A constitutively active form of CREB expressed in IRS-1 knockout cells decreased necdin promoter activity, necdin mRNA, and necdin protein levels, leading to a partial restoration of differentiation. By contrast, forkhead box protein (Fox)O1, which is regulated by the phosphoinositide 3 kinase-Akt pathway, increased necdin promoter activity. Based on reporter gene assays using truncations of the necdin promoter and chromatin immunoprecipitation studies, we demonstrated that CREB and FoxO1 are recruited to the necdin promoter, likely interacting with specific consensus sequences in the proximal region. Based on these results, we propose that insulin/IGF-I act through IRS-1 phosphorylation to stimulate differentiation of brown preadipocytes via two complementary pathways: 1) the Ras-ERK1/2 pathway to activate CREB and 2) the phosphoinositide 3 kinase-Akt pathway to deactivate FoxO1. These two pathways combine to decrease necdin levels and permit the clonal expansion and coordinated gene expression necessary to complete brown adipocyte differentiation.
Collapse
Affiliation(s)
- Aaron M Cypess
- Research Division, Joslin Diabetes Center, Department of Medicine, Harvard Medical School, Boston, Massachusetts 02215, USA.
| | | | | | | | | | | | | | | |
Collapse
|
14
|
Abstract
The gut microbiota has been implicated in host nutrient absorption and energy homeostasis. We studied the influence of different diets on body composition in germ-free (GF) and conventional (CV) mice. GF and CV male adult C3H mice were fed ad libitum a semi-synthetic low-fat diet (LFD; carbohydrate-protein-fat ratio: 41:42:17; 19.8 kJ/g), a high-fat diet (HFD; 41:16:43; 21.4 kJ/g) or a commercial Western diet (WD; 41:19:41; 21.5 kJ/g). There was no difference in body weight gain between GF and CV mice on the LFD. On the HFD, GF mice gained more body weight and body fat than CV mice, and had lower energy expenditure. GF mice on the WD gained significantly less body fat than GF mice on the HFD. GF mice on both HFD and WD showed increased intestinal mRNA expression of fasting-induced adipose factor/angiopoietin-like protein 4 (Fiaf/Angptl4), but they showed no major changes in circulating Fiaf/Angptl4 compared with CV mice. The faecal microbiota composition of the CV mice differed between diets: the proportion of Firmicutes increased on both HFD and WD at the expense of the Bacteroidetes. This increase in the Firmicutes was mainly due to the proliferation of one family within this phylum: the Erysipelotrichaceae. We conclude that the absence of gut microbiota does not provide a general protection from diet-induced obesity, that intestinal production of Fiaf/Angptl4 does not play a causal role in gut microbiota-mediated effects on fat storage and that diet composition affects gut microbial composition to larger extent than previously thought.
Collapse
|
15
|
Barros E, Lezar S, Anttonen MJ, van Dijk JP, Röhlig RM, Kok EJ, Engel KH. Comparison of two GM maize varieties with a near-isogenic non-GM variety using transcriptomics, proteomics and metabolomics. PLANT BIOTECHNOLOGY JOURNAL 2010; 8:436-51. [PMID: 20132517 DOI: 10.1111/j.1467-7652.2009.00487.x] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The aim of this study was to evaluate the use of four nontargeted analytical methodologies in the detection of unintended effects that could be derived during genetic manipulation of crops. Three profiling technologies were used to compare the transcriptome, proteome and metabolome of two transgenic maize lines with the respective control line. By comparing the profiles of the two transgenic lines grown in the same location over three growing seasons, we could determine the extent of environmental variation, while the comparison with the control maize line allowed the investigation of effects caused by a difference in genotype. The effect of growing conditions as an additional environmental effect was also evaluated by comparing the Bt-maize line with the control line from plants grown in three different locations in one growing season. The environment was shown to play an important effect in the protein, gene expression and metabolite levels of the maize samples tested where 5 proteins, 65 genes and 15 metabolites were found to be differentially expressed. A distinct separation between the three growing seasons was also found for all the samples grown in one location. Together, these environmental factors caused more variation in the different transcript/protein/metabolite profiles than the different genotypes.
Collapse
Affiliation(s)
- Eugenia Barros
- Council for Scientific and Industrial Research (CSIR), Biosciences, Brummeria, Pretoria, South Africa.
| | | | | | | | | | | | | |
Collapse
|
16
|
Sziderics AH, Oufir M, Trognitz F, Kopecky D, Matusíková I, Hausman JF, Wilhelm E. Organ-specific defence strategies of pepper (Capsicum annuum L.) during early phase of water deficit. PLANT CELL REPORTS 2010; 29:295-305. [PMID: 20087595 DOI: 10.1007/s00299-010-0822-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2009] [Revised: 01/07/2010] [Accepted: 01/08/2010] [Indexed: 05/23/2023]
Abstract
Drought is one of the major factors that limits crop production and reduces yield. To understand the early response of plants under nearly natural conditions, pepper plants (Capsicum annuum L.) were grown in a greenhouse and stressed by withholding water for 1 week. Plants adapted to the decreasing water content of the soil by adjustment of their osmotic potential in root tissue. As a consequence of drought, strong accumulation of raffinose, glucose, galactinol and proline was detected in the roots. In contrast, in leaves the levels of fructose, sucrose and also galactinol increased. Due to the water deficit cadaverine, putrescine, spermidine and spermine accumulated in leaves, whereas the concentration of polyamines was reduced in roots. To study the molecular basis of these responses, a combined approach of suppression subtractive hybridisation and microarray technique was performed on the same material. A total of 109 unique ESTs were detected as responsive to drought, while additional 286 ESTs were selected from the bulk of rare transcripts on the array. The metabolic profiles of stressed pepper plants are discussed with respect to the transcriptomic changes detected, while attention is given to the differences between defence strategies of roots and leaves.
Collapse
Affiliation(s)
- Astrid Heide Sziderics
- Department of Health and Environment/Bioresources, PICME, AIT Austrian Institute of Technology GmbH, 2444, Seibersdorf, Austria
| | | | | | | | | | | | | |
Collapse
|
17
|
Boeuf S, Börger M, Hennig T, Winter A, Kasten P, Richter W. Enhanced ITM2A expression inhibits chondrogenic differentiation of mesenchymal stem cells. Differentiation 2009; 78:108-15. [PMID: 19541402 DOI: 10.1016/j.diff.2009.05.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2008] [Revised: 05/08/2009] [Accepted: 05/20/2009] [Indexed: 01/22/2023]
Abstract
Mesenchymal stem cells (MSC) from bone marrow or adipose tissue (ASC) are broadly discussed as a cell population able to support cartilage regeneration and thus represent interesting candidates for cell-based tissue engineering in cartilage. ASC could represent an easily accessible and therefore particularly suitable source of cells. Their chondrogenic differentiation potential is, however, lower than that of MSC. The aim of this work was to characterise ASC in comparison to MSC in order to identify genes which may be involved in mechanisms causing the altered chondrogenic potential of ASC. Representational difference analysis was used to identify genes with higher expression in undifferentiated ASC than in MSC. Expression levels of identified genes were confirmed by real-time RT-PCR. Integral membrane protein 2A (ITM2A) was higher expressed in expanded ASC than in MSC in a donor-independent manner. During early chondrogenic differentiation in spheroid cultures ITM2A levels remained low in MSC and a transient down-regulation occurred in ASC correlating with successful chondrogenesis. Persisting ITM2A levels were found in non-differentiating ASC. Consistent with this finding, forced expression of ITM2A in the mouse mesenchymal stem cell line C3H10T1/2 prevented chondrogenic induction. In conclusion, ITM2A may in early stages of differentiation be associated with an inhibition of the initiation of chondrogenesis and elevated expression of ITM2A in ASC may therefore be linked to the poorer chondrogenic differentiation potential of these cells.
Collapse
Affiliation(s)
- Stephane Boeuf
- Division of Experimental Orthopaedics, Orthopaedic University Hospital of Heidelberg, Germany
| | | | | | | | | | | |
Collapse
|
18
|
Pattrick M, Luckett J, Yue L, Stover C. Dual role of complement in adipose tissue. Mol Immunol 2009; 46:755-60. [DOI: 10.1016/j.molimm.2008.09.013] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2008] [Accepted: 09/08/2008] [Indexed: 02/07/2023]
|
19
|
van Beek EA, Bakker AH, Kruyt PM, Vink C, Saris WH, Franssen-van Hal NLW, Keijer J. Comparative expression analysis of isolated human adipocytes and the human adipose cell lines LiSa-2 and PAZ6. Int J Obes (Lond) 2008; 32:912-21. [PMID: 18283285 DOI: 10.1038/ijo.2008.10] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
OBJECTIVE To obtain insight in the extent to which the human cell lines LiSa-2 and PAZ6 resemble isolated primary human adipocytes. DESIGN A combination of cDNA subtraction (representative difference analysis; RDA) and cDNA microarray analysis was used to select adipose specific genes to compare isolated (pre-)adipocytes with (un)differentiated LiSa-2 and PAZ6 cells. MEASUREMENTS RDA was performed on adipose tissue against lung tissue. A total of 1400 isolated genes were sequenced and cDNA microarray technology was used for further adipose related gene selection. 30 genes that were found to be enriched in adipose tissue were used to compare isolated human adipocytes and LiSa-2 and PAZ6 cells in the differentiated and undifferentiated states. RESULTS RDA and microarray analysis resulted in the identification of adipose enriched genes, but not in adipose specific genes. Of the 30 most differentially expressed genes, as expected, most were related to lipid metabolism. The second category consisted of methyltransferases, DNMT1, DNMT3a, RNMT and SHMT2, of which the expression was differentiation dependent and higher in differentiated adipocytes. Using the 30 adipose expressed genes, it was found that isolated adipocytes on one hand, and PAZ6 and LiSa-2 adipocytes on the other, differ primarily in lipid metabolism. Furthermore, LiSa-2 cells seem to be more similar to isolated adipocytes than PAZ6 cells. CONCLUSION The LiSa-2 cell line is a good model for differentiated adipocytes, although one should keep in mind that the lipid metabolism in these cells deviates from the in vivo situation Furthermore, our results imply that methylation may have an important function in terminal adipocyte differentiation.
Collapse
Affiliation(s)
- E A van Beek
- RIKILT-Institute of Food Safety, Wageningen UR, Wageningen, The Netherlands
| | | | | | | | | | | | | |
Collapse
|
20
|
Katterle Y, Keipert S, Hof J, Klaus S. Dissociation of obesity and insulin resistance in transgenic mice with skeletal muscle expression of uncoupling protein 1. Physiol Genomics 2008; 32:352-9. [DOI: 10.1152/physiolgenomics.00194.2007] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
We evaluated the effect of skeletal muscle mitochondrial uncoupling on energy and glucose metabolism under different diets. For 3 mo, transgenic HSA-mUCP1 mice with ectopic expression of uncoupling protein 1 in skeletal muscle and wild-type littermates were fed semisynthetic diets with varying macronutrient ratios (energy % carbohydrate-protein-fat): HCLF (41:42:17), HCHF (41:16:43); LCHF (11:45:44). Body composition, energy metabolism, and insulin resistance were assessed by NMR, indirect calorimetry, and insulin tolerance test, respectively. Gene expression in different organs was determined by real-time PCR. In wild type, both high-fat diets led to an increase in body weight and fat. HSA-mUCP1 mice considerably increased body fat on HCHF but stayed lean on the other diets. Irrespective of differences in body fat content, HSA-mUCP1 mice showed higher insulin sensitivity and decreased plasma insulin and liver triglycerides. Respiratory quotient and gene expression indicated overall increased carbohydrate oxidation of HSA-mUCP1 but a preferential channeling of fatty acids into muscle rather than liver with high-fat diets. Evidence for increased lipogenesis in white fat of HSA-mUCP1 mice suggests increased energy dissipating substrate cycling. Retinol binding protein 4 expression in white fat was increased in HSA-mUCP1 mice despite increased insulin sensitivity, excluding a causal role in the development of insulin resistance. We conclude that skeletal muscle mitochondrial uncoupling does not protect from the development of obesity in all circumstances. Rather it can lead to a “healthy” obese phenotype by preserving insulin sensitivity and a high metabolic flexibility, thus protecting from the development of obesity associated disturbances of glucose homeostasis.
Collapse
Affiliation(s)
- Yvonne Katterle
- German Institute of Human Nutrition in Potsdam-Rehbruecke, Group of Energy Metabolism, Nuthetal, Germany
| | - Susanne Keipert
- German Institute of Human Nutrition in Potsdam-Rehbruecke, Group of Energy Metabolism, Nuthetal, Germany
| | - Jana Hof
- German Institute of Human Nutrition in Potsdam-Rehbruecke, Group of Energy Metabolism, Nuthetal, Germany
| | - Susanne Klaus
- German Institute of Human Nutrition in Potsdam-Rehbruecke, Group of Energy Metabolism, Nuthetal, Germany
| |
Collapse
|
21
|
Imprinted Genes, Postnatal Adaptations and Enduring Effects on Energy Homeostasis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2008; 626:41-61. [DOI: 10.1007/978-0-387-77576-0_4] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
|
22
|
Deponti D, François S, Baesso S, Sciorati C, Innocenzi A, Broccoli V, Muscatelli F, Meneveri R, Clementi E, Cossu G, Brunelli S. Necdin mediates skeletal muscle regeneration by promoting myoblast survival and differentiation. ACTA ACUST UNITED AC 2007; 179:305-19. [PMID: 17954612 PMCID: PMC2064766 DOI: 10.1083/jcb.200701027] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Regeneration of muscle fibers that are lost during pathological muscle degeneration or after injuries is sustained by the production of new myofibers. An important cell type involved in muscle regeneration is the satellite cell. Necdin is a protein expressed in satellite cell–derived myogenic precursors during perinatal growth. However, its function in myogenesis is not known. We compare transgenic mice that overexpress necdin in skeletal muscle with both wild-type and necdin null mice. After muscle injury the necdin null mice show a considerable defect in muscle healing, whereas mice that overexpress necdin show a substantial increase in myofiber regeneration. We also find that in muscle, necdin increases myogenin expression, accelerates differentiation, and counteracts myoblast apoptosis. Collectively, these data clarify the function and mechanism of necdin in skeletal muscle and show the importance of necdin in muscle regeneration.
Collapse
Affiliation(s)
- Daniela Deponti
- Department of Histology and Medical Embryology, University of Roma-La Sapienza, 00161 Rome, Italy
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Gallardo N, Bonzón-Kulichenko E, Fernández-Agulló T, Moltó E, Gómez-Alonso S, Blanco P, Carrascosa JM, Ros M, Andrés A. Tissue-specific effects of central leptin on the expression of genes involved in lipid metabolism in liver and white adipose tissue. Endocrinology 2007; 148:5604-10. [PMID: 17823267 DOI: 10.1210/en.2007-0933] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Leptin reduces adiposity and exerts antisteatotic effects on nonadipose tissues. However, the mechanisms underlying leptin effects on lipid metabolism in liver and white adipose tissue have not been fully clarified. Here, we have studied the effects of central leptin administration on key enzymes and transcription factors involved in lipid metabolism in liver and epididymal adipose tissue. Intracerebroventricular leptin infusion for 7 d did not change leptin plasma levels but decreased triacylglyceride content in liver, epididymal adipose tissue, and plasma. In both tissues this treatment markedly decreased the expression of key enzymes of the de novo fatty acid (FA) synthesis such as acetyl-coenzyme A-carboxylase, FA synthase, and stearoyl-coenzyme A desaturase-1, in parallel with a reduction in mRNA expression of sterol regulatory element binding protein-1c in liver and carbohydrate regulatory element binding protein in adipose tissue. In addition, leptin also decreased phosphoenol-pyruvate carboxykinase-C expression in adipose tissue, an enzyme involved in glyceroneogenesis in this tissue. Central leptin administration down-regulates delta-6-desaturase expression in liver and adipose tissue, in parallel with the decrease of the expression of sterol regulatory element binding protein-1c in liver and peroxisome proliferator activated receptor alpha in adipose tissue. Finally, leptin treatment, by regulating adipose triglyceride lipase/hormone sensitive lipase/diacylglycerol transferase 1 expression, also established a new partitioning in the FA-triacylglyceride cycling in adipose tissue, increasing lipolysis and probably the FA efflux from this tissue, and favoring in parallel the FA uptake and oxidation in the liver. These results suggest that leptin, acting at central level, exerts tissue-specific effects in limiting fat tissue mass and lipid accumulation in nonadipose tissues, preventing the development of obesity and type 2 diabetes.
Collapse
Affiliation(s)
- Nilda Gallardo
- Area de Bioquímica, Facultad de Químicas, Regional Centre for Biomedical Research, Avenida Camilo José Cela 10, Universidad de Castilla-La Mancha, Ciudad Real, Spain
| | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Sakamoto H, Suzuki M, Abe T, Hosoyama T, Himeno E, Tanaka S, Greally JM, Hattori N, Yagi S, Shiota K. Cell type-specific methylation profiles occurring disproportionately in CpG-less regions that delineate developmental similarity. Genes Cells 2007; 12:1123-32. [PMID: 17903172 DOI: 10.1111/j.1365-2443.2007.01120.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Our previous studies using restriction landmark genomic scanning (RLGS) defined tissue- or cell-specific DNA methylation profiles. It remains to be determined whether the DNA sequence compositions in the genomic contexts of the NotI loci tested by RLGS influence their tendency to change with differentiation. We carried out 3834 methylation measurements consisting of 213 NotI loci in the mouse genome in 18 different tissues and cell types, using quantitative real-time PCR based on a Virtual image rlgs database. Loci were categorized as CpG islands or other, and as unique or repetitive sequences, each category being associated with a variety of methylation categories. Strikingly, the tissue-dependently and differentially methylated regions (T-DMRs) were disproportionately distributed in the non-CpG island loci. These loci were located not only in 5'-upstream regions of genes but also in intronic and non-genic regions. Hierarchical clustering of the methylation profiles could be used to define developmental similarity and cellular phenotypes. The results show that distinctive tissue- and cell type-specific methylation profiles by RLGS occur mostly at NotI sites located at non-CpG island sequences, which delineate developmental similarity of different cell types. The finding indicates the power of NotI methylation profiles in evaluating the relatedness of different cell types.
Collapse
Affiliation(s)
- Hideki Sakamoto
- Cellular Biochemistry, Animal Resource Sciences/Veterinary Medical Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Abstract
The development of obesity not only depends on the balance between food intake and caloric utilization but also on the balance between white adipose tissue, which is the primary site of energy storage, and brown adipose tissue, which is specialized for energy expenditure. In addition, some sites of white fat storage in the body are more closely linked than others to the metabolic complications of obesity, such as diabetes. In this Review, we consider how the developmental origins of fat contribute to its physiological, cellular, and molecular heterogeneity and explore how these factors may play a role in the growing epidemic of obesity.
Collapse
Affiliation(s)
- Stephane Gesta
- Joslin Diabetes Center, Harvard Medical School, Boston, MA 02215, USA
| | | | | |
Collapse
|
26
|
Aksu S, Koczan D, Renne U, Thiesen HJ, Brockmann GA. Differentially expressed genes in adipose tissues of high body weight-selected (obese) and unselected (lean) mouse lines. J Appl Genet 2007; 48:133-43. [PMID: 17495347 DOI: 10.1007/bf03194671] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Recently, quantitative trait loci (QTLs) for body weight and obesity have been mapped in an intercross population between the high body weight-selected mouse line DU6i and the inbred line DBA/2. Most QTLs were highly significant, but had small effects only. Under the hypothesis that small-effect QTLs might result from changes in gene activity, our strategy to identify candidate genes for the observed effects was directed towards the identification of differentially expressed genes. Therefore, here we compare the transcription profile of about 11 000 genes in epididymal fat tissues of males of two high body weight-selected (DU6 and DU6i) and two unselected mouse lines (DUKs and DBA/2). For the hybridisation of GeneChips, we used pooled samples of 20 individual mice. By pair-wise comparisons between selected and unselected mouse lines, a set of 77 genes was identified representing genes whose level of expression differed between obese and lean mouse strains. According to the functional classification of genes, 69 differentially expressed genes were involved in regulatory and metabolic pathways, cell division, cell stability, or immune response, and thus might have an effect on body weight and fat accumulation. 14 out of these genes, occur in QTL regions for body weight or abdominal fat weight. Further analyses are necessary to discriminate between genes directly causing QTL effects and indirectly regulated differentially expressed genes.
Collapse
Affiliation(s)
- Soner Aksu
- Institute for Animal Sciences, Humboldt-Universität zu Berlin, Invalidenstrasse 42, 10115 Berlin, Germany
| | | | | | | | | |
Collapse
|
27
|
Timmons JA, Wennmalm K, Larsson O, Walden TB, Lassmann T, Petrovic N, Hamilton DL, Gimeno RE, Wahlestedt C, Baar K, Nedergaard J, Cannon B. Myogenic gene expression signature establishes that brown and white adipocytes originate from distinct cell lineages. Proc Natl Acad Sci U S A 2007; 104:4401-6. [PMID: 17360536 PMCID: PMC1810328 DOI: 10.1073/pnas.0610615104] [Citation(s) in RCA: 532] [Impact Index Per Article: 31.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Attainment of a brown adipocyte cell phenotype in white adipocytes, with their abundant mitochondria and increased energy expenditure potential, is a legitimate strategy for combating obesity. The unique transcriptional regulators of the primary brown adipocyte phenotype are unknown, limiting our ability to promote brown adipogenesis over white. In the present work, we used microarray analysis strategies to study primary preadipocytes, and we made the striking discovery that brown preadipocytes demonstrate a myogenic transcriptional signature, whereas both brown and white primary preadipocytes demonstrate signatures distinct from those found in immortalized adipogenic models. We found a plausible SIRT1-related transcriptional signature during brown adipocyte differentiation that may contribute to silencing the myogenic signature. In contrast to brown preadipocytes or skeletal muscle cells, white preadipocytes express Tcf21, a transcription factor that has been shown to suppress myogenesis and nuclear receptor activity. In addition, we identified a number of developmental genes that are differentially expressed between brown and white preadipocytes and that have recently been implicated in human obesity. The interlinkage between the myocyte and the brown preadipocyte confirms the distinct origin for brown versus white adipose tissue and also represents a plausible explanation as to why brown adipocytes ultimately specialize in lipid catabolism rather than storage, much like oxidative skeletal muscle tissue.
Collapse
Affiliation(s)
- James A. Timmons
- *Wenner–Gren Institute, Arrhenius Laboratories, Stockholm University, SE-106 91 Stockholm, Sweden
- School of Life Sciences, Heriot–Watt University, Edinburgh EH14 4AS, Scotland
- Center for Genomics and Bioinformatics, Berzelius Väg 35, Karolinska Institutet, SE-171 77 Stockholm, Sweden
- To whom correspondence may be addressed at:
School of Life Sciences, John Muir Building, Heriot–Watt University, Edinburgh EH14 4AS, Scotland. E-mail:
| | - Kristian Wennmalm
- Center for Genomics and Bioinformatics, Berzelius Väg 35, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Ola Larsson
- Center for Genomics and Bioinformatics, Berzelius Väg 35, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Tomas B. Walden
- *Wenner–Gren Institute, Arrhenius Laboratories, Stockholm University, SE-106 91 Stockholm, Sweden
- School of Life Sciences, Heriot–Watt University, Edinburgh EH14 4AS, Scotland
| | - Timo Lassmann
- Center for Genomics and Bioinformatics, Berzelius Väg 35, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Natasa Petrovic
- *Wenner–Gren Institute, Arrhenius Laboratories, Stockholm University, SE-106 91 Stockholm, Sweden
- Center for Genomics and Bioinformatics, Berzelius Väg 35, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - D. Lee Hamilton
- Division of Molecular Physiology, University of Dundee, Dundee DD1 5EH, Scotland; and
| | - Ruth E. Gimeno
- Millennium Pharmaceuticals, Inc., 40 Landsdowne Street, Cambridge, MA 02139
| | - Claes Wahlestedt
- Center for Genomics and Bioinformatics, Berzelius Väg 35, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Keith Baar
- Division of Molecular Physiology, University of Dundee, Dundee DD1 5EH, Scotland; and
| | - Jan Nedergaard
- *Wenner–Gren Institute, Arrhenius Laboratories, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Barbara Cannon
- *Wenner–Gren Institute, Arrhenius Laboratories, Stockholm University, SE-106 91 Stockholm, Sweden
- School of Life Sciences, Heriot–Watt University, Edinburgh EH14 4AS, Scotland
- To whom correspondence may be addressed at:
Wenner–Gren Institute, Arrhenius Laboratories, Stockholm University, SE-106 91 Stockholm, Sweden. E-mail:
| |
Collapse
|
28
|
Kok EJ, Franssen-van Hal NLW, Winnubst LNW, Kramer EHM, Dijksma WTP, Kuiper HA, Keijer J. Assessment of representational difference analysis (RDA) to construct informative cDNA microarrays for gene expression analysis of species with limited transcriptome information, using red and green tomatoes as a model. JOURNAL OF PLANT PHYSIOLOGY 2007; 164:337-49. [PMID: 16630671 DOI: 10.1016/j.jplph.2006.02.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2005] [Accepted: 02/03/2006] [Indexed: 05/08/2023]
Abstract
Microarray technology makes it feasible to analyse the expression of thousands of different gene elements in a single experiment. Most informative are 'whole genome' arrays, where all gene expression products of a single species or variety are represented. Such arrays are now available for a limited number of model species. However, for other, less well-documented species other routes are still necessary to obtain informative arrays. This includes the use of cDNA libraries. To enhance the amount of information that can be obtained from cDNA libraries, redundancy needs to be minimised, and the number of cDNAs relevant for the conditions of interest needs to be increased. Here, we used representational difference analysis (RDA), a mRNA subtraction procedure, as a tool to enhance the efficiency of cDNA libraries to be used to generate microarrays. Tomato was chosen as a model system for a less well-documented species. cDNA libraries for two distinct physiological conditions of tomato fruits, red and green, were made. The libraries were characterized by sequencing and hybridisation analysis. The RDA procedure was shown to be effective in selecting for genes of relevance for the physiological conditions under investigation, and against constitutively expressed genes. At the same time, redundancy was reduced, but complete normalisation was not obtained, and subsequent sequence analysis will be required to obtain non-redundant arrays. Further, known and putative ripening-related cDNAs were identified in hybridisation experiments on the basis of RNA populations as isolated from the green and red stage of ripening.
Collapse
Affiliation(s)
- Esther J Kok
- RIKILT Institute for Food Safety, Bornsesteeg 45, 6700 AE Wageningen, The Netherlands.
| | | | | | | | | | | | | |
Collapse
|
29
|
van Beek EA, Bakker AH, Kruyt PM, Hofker MH, Saris WH, Keijer J. Intra- and interindividual variation in gene expression in human adipose tissue. Pflugers Arch 2007; 453:851-61. [PMID: 17061120 DOI: 10.1007/s00424-006-0164-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2006] [Revised: 08/07/2006] [Accepted: 08/28/2006] [Indexed: 10/24/2022]
Abstract
Adipose tissue is a highly plastic tissue with an important endocrine and metabolic function. To understand its role in human health and disease, it is necessary to understand the extent of variation and the specific differences within and between different depots and subjects. We employed cDNA microarray analysis to investigate this in human subjects ranging from lean to mildly obese. We observe (1) high similarity between different samples of one adipose depot, (2) only small differences between the subcutaneous and visceral adipose tissue depot and (3) larger differences in gene expression between different individuals (per depot). The major variation within adipose depots can be attributed to differences in the non-adipocyte component of adipose tissue. Using only non-obese subjects, we identified genes that were consistently differentially expressed between subcutaneous and omental adipose tissue, despite the variation in gene expression between these subjects. Using quantitative real time polymerase chain reaction (PCR), fatty acid binding protein 4 (FABP4), vimentin (Vim), four and a half LIMs domains (FHL1), CD36 (all higher in subcutaneous adipose tissue) and Matrix Gla protein (MGP; lower in subcutaneous adipose tissue) were confirmed to be significantly differentially expressed between depots.
Collapse
Affiliation(s)
- Esther A van Beek
- Bioactives group, RIKILT- Institute of Food Safety, Wageningen, Wageningen, The Netherlands
| | | | | | | | | | | |
Collapse
|
30
|
Zhang Y, Bossé Y, Marceau P, Biron S, Lebel S, Richard D, Vohl MC, Tchernof A. Gene expression variability in subcutaneous and omental adipose tissue of obese men. Gene Expr 2007; 14:35-46. [PMID: 17933217 PMCID: PMC6042019 DOI: 10.3727/000000007783991772] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
We investigated interindividual variability in gene expression in abdominal subcutaneous (SC) and omental (OM) adipose tissue of 10 massively obese men. Affymetrix human U133A microarrays were used to measure gene expression levels. A total of 6811 probesets generated significant signal in both depots in all samples. Interindividual variability in gene expression was rather low, with more than 90% of transcripts showing a coefficient of variation (CV) lower than 23.6% and 21.7% in OM and SC adipose tissues, respectively. The distributions of CV were similar between the two fat depots. A set of highly variable genes was identified for both tissues on the basis of a high CV and elevated gene expression level. Among the set of highly regulated genes, 18 transcripts were involved in lipid metabolism and 28 transcripts were involved in cell death for SC and OM samples, respectively. In conclusion, gene expression interindividual variability was rather low and globally similar between fat compartments, and the adipose tissue transcriptome appeared as relatively stable, although specific pathways were found to be highly variable in SC and OM depots.
Collapse
Affiliation(s)
- Yonghua Zhang
- *Molecular Endocrinology and Oncology Research Center, Laval University Medical Research Center, Québec, Canada
| | - Yohan Bossé
- †McGill University and Genome Quebec Innovation Center, Montreal, Canada
| | - Picard Marceau
- §Department of Surgery, Laval University, Québec, Canada
| | - Simon Biron
- §Department of Surgery, Laval University, Québec, Canada
| | - Stephan Lebel
- §Department of Surgery, Laval University, Québec, Canada
| | - Denis Richard
- ¶Cardiology Institute, Lava Hospital, Québec, Canada
| | - Marie-Claude Vohl
- *Molecular Endocrinology and Oncology Research Center, Laval University Medical Research Center, Québec, Canada
- ‡Department of Food Science and Nutrition, Laval University, Québec, Canada
| | - André Tchernof
- *Molecular Endocrinology and Oncology Research Center, Laval University Medical Research Center, Québec, Canada
- ‡Department of Food Science and Nutrition, Laval University, Québec, Canada
| |
Collapse
|
31
|
Do MS, Jeong HS, Choi BH, Hunter L, Langley S, Pazmany L, Trayhurn P. Inflammatory gene expression patterns revealed by DNA microarray analysis in TNF-alpha-treated SGBS human adipocytes. Yonsei Med J 2006; 47:729-36. [PMID: 17066518 PMCID: PMC2687760 DOI: 10.3349/ymj.2006.47.5.729] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
We report here the use of human inflammation arrays to study the inflammatory gene expression profile of TNF-alpha- treated human SGBS adipocytes. Human preadipocytes (SGBS) were induced to differentiate in primary culture, and adipocyte differentiation was confirmed, using Oil Red O staining. We treated the differentiated adipocytes with TNF-alpha, and RNA from differentiated adipocytes with or without TNF-alpha treatment was hybridized to MWG human inflammation arrays to compare expression profiles. Eleven genes were up- or down-regulated in TNF-alpha-treated adipocytes. As revealed by array analysis, among 6 up-regulated genes, only eotaxin-1, monocyte chemoattractant protein-1 (MCP-1), and vascular cell adhesion molecule 1 isoform a precursor (VCAM1) were confirmed by real-time polymerase chain reaction (PCR). Similarly, among 5 down-regulated genes, only IL-1 family member 5 (IL1F5), a disintegrin and metalloprotease with thrombospondin motifs-1 preproprotein (ADAMTS1), fibronectin 1 isoform 1 preprotein (FN1), and matrix metalloproteinase 15 preprotein (MMP15) were confirmed by real-time PCR. There was a substantial increase (50-fold) in eotaxin-1 in response to TNF-alpha. Taken together, we have identified several inflammatory molecules expressed in SGBS adipocytes and discovered molecular factors explaining the relationship between obesity and atherosclerosis, focusing on inflammatory cytokines expressed in the TNF-alpha-treated SGBS cells. Further investigation into the role of these up- or down-regulated cytokine genes during the pathological processes leading to the development of atherosclerosis is warranted.
Collapse
Affiliation(s)
- Myoung-Sool Do
- School of Life and Food Sciences, Handong Global University Pohang, Korea.
| | | | | | | | | | | | | |
Collapse
|
32
|
Petzke KJ, Riese C, Klaus S. Short-term, increasing dietary protein and fat moderately affect energy expenditure, substrate oxidation and uncoupling protein gene expression in rats. J Nutr Biochem 2006; 18:400-7. [PMID: 16979329 DOI: 10.1016/j.jnutbio.2006.07.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2006] [Revised: 07/07/2006] [Accepted: 07/19/2006] [Indexed: 11/15/2022]
Abstract
Macronutrient composition of diets can influence body-weight development and energy balance. We studied the short-term effects of high-protein (HP) and/or high-fat (HF) diets on energy expenditure (EE) and uncoupling protein (UCP1-3) gene expression. Adult male rats were fed ad libitum with diets containing different protein-fat ratios: adequate protein-normal fat (AP-NF): 20% casein, 5% fat; adequate protein-high fat (AP-HF): 20% casein, 17% fat; high protein-normal fat (HP-NF): 60% casein, 5% fat; high protein-high fat (HP-HF): 60% casein, 17% fat. Wheat starch was used for adjustment of energy content. After 4 days, overnight EE and oxygen consumption, as measured by indirect calorimetry, were higher and body-weight gain was lower in rats fed with HP diets as compared with rats fed diets with adequate protein content (P<.05). Exchanging carbohydrates by protein increased fat oxidation in HF diet fed groups. The UCP1 mRNA expression in brown adipose tissue was not significantly different in HP diet fed groups as compared with AP diet fed groups. Expression of different homologues of UCPs positively correlated with nighttime oxygen consumption and EE. Moreover, dietary protein and fat distinctly influenced liver UCP2 and skeletal muscle UCP3 mRNA expressions. These findings demonstrated that a 4-day ad libitum high dietary protein exposure influences energy balance in rats. A function of UCPs in energy balance and dissipating food energy was suggested. Future experiments are focused on the regulation of UCP gene expression by dietary protein, which could be important for body-weight management.
Collapse
Affiliation(s)
- Klaus J Petzke
- Groups of Stable Isotopes and of Energy Metabolism, German Institute of Human Nutrition in Potsdam-Rehbrücke (DIfE), D-14558 Nuthetal, Germany.
| | | | | |
Collapse
|
33
|
Hansen JB, Kristiansen K. Regulatory circuits controlling white versus brown adipocyte differentiation. Biochem J 2006; 398:153-68. [PMID: 16898874 PMCID: PMC1550312 DOI: 10.1042/bj20060402] [Citation(s) in RCA: 136] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Adipose tissue is a major endocrine organ that exerts a profound influence on whole-body homoeostasis. Two types of adipose tissue exist in mammals: WAT (white adipose tissue) and BAT (brown adipose tissue). WAT stores energy and is the largest energy reserve in mammals, whereas BAT, expressing UCP1 (uncoupling protein 1), can dissipate energy through adaptive thermogenesis. In rodents, ample evidence supports BAT as an organ counteracting obesity, whereas less is known about the presence and significance of BAT in humans. Despite the different functions of white and brown adipocytes, knowledge of factors differentially influencing the formation of white and brown fat cells is sparse. Here we summarize recent progress in the molecular understanding of white versus brown adipocyte differentiation, including novel insights into transcriptional and signal transduction pathways. Since expression of UCP1 is the hallmark of BAT and a key factor determining energy expenditure, we also review conditions associated with enhanced energy expenditure and UCP1 expression in WAT that may provide information on processes involved in brown adipocyte differentiation.
Collapse
Affiliation(s)
- Jacob B Hansen
- Department of Medical Biochemistry and Genetics, the Panum Institute, University of Copenhagen, DK-2200 Copenhagen N, Denmark.
| | | |
Collapse
|
34
|
Rosso R, Lucioni M. Normal and neoplastic cells of brown adipose tissue express the adhesion molecule CD31. Arch Pathol Lab Med 2006; 130:480-2. [PMID: 16594742 DOI: 10.5858/2006-130-480-nancob] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
CONTEXT CD31 (platelet-endothelial cell adhesion molecule-1; PECAM-1), an adhesion molecule involved in the process of angiogenesis, is used as a marker of normal and neoplastic vascularization. During the assessment of angiogenesis and vascular invasion in a thymic carcinoid tumor, we observed unexpected immunostaining for CD31 in perithymic brown fat nests. OBJECTIVE To determine whether CD31 is expressed by normal and neoplastic cells of brown fat, a tissue whose thermogenetic activity depends heavily on high perfusion. DESIGN Formalin-fixed, paraffin-embedded archival tissues were immunostained by the labeled avidin-biotin method using antibodies against CD31 (clones JC70A and 1A10) after retrieval of heat-induced epitopes. Archival tissues included perithymic, periadrenal, axillary, and neck adipose tissue in which were embedded nests of brown fat (n = 15), hibernoma (n = 3), lipoma (n = 6), well-differentiated liposarcoma (n = 4), and myxoid liposarcoma (n = 4). RESULTS Invariably, multivacuolated and univacuolated adipocytes of normal brown fat and hibernomas were intensely positive for the CD31 antigen. The immunostaining "decorated" cell membranes and the membranes of intracytoplasmic vacuoles. No expression of CD31 was found in normal adipocytes of white fat, in neoplastic cells of lipomas, or in multivacuolated lipoblasts of well-differentiated and myxoid liposarcomas. CONCLUSIONS The spectrum of cell types that express CD31 is expanded to include normal and neoplastic brown fat cells. We speculate that the expression of CD31 may play a role in the development and maintenance of the vascular network characterizing this specialized adipose tissue. Moreover, CD31 may inhibit the Bax-mediated apoptosis of brown fat cells. For practical purposes, CD31 may be used as an immunohistochemical marker for distinguishing between white and brown fat and for diagnosing hibernoma in paraffin sections.
Collapse
Affiliation(s)
- Renato Rosso
- From the Department of Pathology, University of Pavia, IRCCS San Matteo Hospital, Pavia, Italy.
| | | |
Collapse
|
35
|
Goldfine AB, Crunkhorn S, Costello M, Gami H, Landaker EJ, Niinobe M, Yoshikawa K, Lo D, Warren A, Jimenez-Chillaron J, Patti ME. Necdin and E2F4 are modulated by rosiglitazone therapy in diabetic human adipose and muscle tissue. Diabetes 2006; 55:640-50. [PMID: 16505226 DOI: 10.2337/diabetes.55.03.06.db05-1015] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
To identify novel pathways mediating molecular mechanisms of thiazolidinediones (TZDs) in humans, we assessed gene expression in adipose and muscle tissue from six subjects with type 2 diabetes before and after 8 weeks of treatment with rosiglitazone. mRNA was analyzed using Total Gene Expression Analysis (TOGA), an automated restriction-based cDNA display method with quantitative analysis of PCR products. The expression of cell cycle regulatory transcription factors E2F4 and the MAGE protein necdin were similarly altered in all subjects after rosiglitazone treatment. E2F4 expression was decreased by 10-fold in muscle and 2.5-fold in adipose tissue; necdin was identified in adipose tissue only and increased 1.8-fold after TZD treatment. To determine whether changes were related to an effect of the drug or adipogenesis, we evaluated the impact of rosiglitazone and differentiation independently in 3T3-L1 adipocytes. While treatment of differentiated adipocytes with rosiglitazone did not alter E2F4 or necdin, expression of both genes was significantly altered during differentiation. Differentiation was associated with increased cytosolic localization of E2F4. Moreover, necdin overexpression potently inhibited adipocyte differentiation and cell cycle progression. These data suggest that changes in necdin and E2F4 expression after rosiglitazone exposure in humans are associated with altered adipocyte differentiation and may contribute to improved insulin sensitivity in humans treated with TZDs.
Collapse
Affiliation(s)
- Allison B Goldfine
- Research Division, Joslin Diabetes Center, One Joslin Place, Boston, MA 02215, USA.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Scimè A, Grenier G, Huh MS, Gillespie MA, Bevilacqua L, Harper ME, Rudnicki MA. Rb and p107 regulate preadipocyte differentiation into white versus brown fat through repression of PGC-1alpha. Cell Metab 2005; 2:283-95. [PMID: 16271529 DOI: 10.1016/j.cmet.2005.10.002] [Citation(s) in RCA: 160] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2005] [Revised: 06/28/2005] [Accepted: 10/11/2005] [Indexed: 10/25/2022]
Abstract
The Rb family, Rb, p107, and p130, play important roles in cell cycle control and cellular differentiation, and Rb has been suggested to regulate adipocyte differentiation. We report here that mice lacking p107 displayed a uniform replacement of white adipose tissue (WAT) with brown adipose tissue (BAT). Mutant WAT depots contained mutilocular adipocytes that expressed elevated levels of PGC-1alpha and UCP-1 typical of BAT. WAT from p107-/- mice contained markedly elevated numbers of adipogenic precursors that displayed downregulated expression of pRb. Consistent with the hypothesis that pRb is required for adult adipocyte differentiation, Cre-mediated deletion of Rb in adult primary preadipocytes blocked their differentiation into white adipocytes. Importantly, pRb was observed to bind the PGC-1alpha promoter and repress transcription. Therefore, p107 and pRb regulate PGC-1alpha expression to control the switch between white and brown adipocyte differentiation from a common pool of presumptive adult progenitors in fat tissue.
Collapse
Affiliation(s)
- Anthony Scimè
- Molecular Medicine Program, Ottawa Health Research Institute, 501 Smyth Road, Ottawa, Ontario K1H 8L6, Canada
| | | | | | | | | | | | | |
Collapse
|
37
|
|
38
|
Tseng YH, Butte AJ, Kokkotou E, Yechoor VK, Taniguchi CM, Kriauciunas KM, Cypess AM, Niinobe M, Yoshikawa K, Patti ME, Kahn CR. Prediction of preadipocyte differentiation by gene expression reveals role of insulin receptor substrates and necdin. Nat Cell Biol 2005; 7:601-11. [PMID: 15895078 DOI: 10.1038/ncb1259] [Citation(s) in RCA: 182] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2005] [Accepted: 04/28/2005] [Indexed: 12/15/2022]
Abstract
The insulin/IGF-1 (insulin-like growth factor 1) signalling pathway promotes adipocyte differentiation via complex signalling networks. Here, using microarray analysis of brown preadipocytes that are derived from wild-type and insulin receptor substrate (Irs) knockout animals that exhibit progressively impaired differentiation, we define 374 genes/expressed-sequence tags whose expression in preadipocytes correlates with the ultimate ability of the cells to differentiate. Many of these genes, including preadipocyte factor-1 (Pref-1) and multiple members of the Wnt signalling pathway, are related to early adipogenic events. Necdin is also markedly increased in Irs knockout cells that cannot differentiate, and knockdown of necdin restores brown adipogenesis with downregulation of Pref-1 and Wnt10a expression. Insulin receptor substrate proteins regulate a necdin-E2F4 interaction that represses peroxisome-proliferator-activated receptor gamma (PPARgamma) transcription via a cyclic AMP response element binding protein (CREB)-dependent pathway. Together these define a key signalling network that is involved in brown preadipocyte determination.
Collapse
Affiliation(s)
- Yu-Hua Tseng
- Research Division, Joslin Diabetes Center, Children's Hospital, Harvard Medical School, Boston, MA 02215, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Klaus S, Rudolph B, Dohrmann C, Wehr R. Expression of uncoupling protein 1 in skeletal muscle decreases muscle energy efficiency and affects thermoregulation and substrate oxidation. Physiol Genomics 2005; 21:193-200. [PMID: 15687481 DOI: 10.1152/physiolgenomics.00299.2004] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Skeletal muscle uncoupling by ectopic expression of mitochondrial uncoupling protein 1 (UCP1) has been shown to result in a lean phenotype in mice characterized by increased energy expenditure (EE), resistance to diet-induced obesity, and improved glucose tolerance. Here, we investigated in detail the effect of ectopic UCP1 expression in skeletal muscle on thermoregulation and energy homeostasis in HSA-mUCP1 transgenic mice. Thermoneutrality was determined to be ∼30°C for both wild-type (WT) and transgenic mice. EE, body temperature (Tb), activity, and respiratory quotient (RQ) were then measured over 24 h at ambient temperatures (Ta) of 30, 22, and 5°C. HSA-mUCP1 transgenic mice showed increased activity-related EE and heat loss but similar basal metabolic rate compared with WT. Tbat resting periods was progressively decreased with declining Tain HSA-mUCP1 transgenic mice but not in WT. Compared with WT littermates, the transgenic HSA-mUCP1 mice displayed increased RQ levels during night time, indicative of increased overall glucose oxidation, and failed to decrease their RQ levels with declining Ta. Thus increased EE caused by skeletal muscle uncoupling is clearly due to a decreased muscle energy efficiency during activity combined with increased glucose oxidation and a compromised thermoregulation associated with increased overall heat loss. At Tas below thermoneutrality, this puts increasing energy demands on the animals, whereas at thermoneutrality most differences in energy metabolism are not apparent any more.
Collapse
Affiliation(s)
- Susanne Klaus
- German Institute of Human Nutrition Potsdam-Rehbruecke, Group of Energy Metabolism, Nuthetal, Germany.
| | | | | | | |
Collapse
|
40
|
Klaus S, Pültz S, Thöne-Reineke C, Wolfram S. Epigallocatechin gallate attenuates diet-induced obesity in mice by decreasing energy absorption and increasing fat oxidation. Int J Obes (Lond) 2005; 29:615-23. [PMID: 15738931 DOI: 10.1038/sj.ijo.0802926] [Citation(s) in RCA: 292] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE To examine the antiobesity effect of epigallocatechin gallate (EGCG), a green tea bioactive polyphenol in a mouse model of diet-induced obesity. METHODS Obesity was induced in male New Zealand black mice by feeding of a high-fat diet. EGCG purified from green tea (TEAVIGO) was supplemented in the diet (0.5 and 1%). Body composition (quantitative magnetic resonance), food intake, and food digestibility were recorded over a 4-week period. Animals were killed and mRNA levels of uncoupling proteins (UCP1-3), leptin, malic enzyme (ME), stearoyl-CoA desaturase-1 (SCD1), glucokinase (GK), and pyruvate kinase (PK) were analysed in different tissues. Also investigated were acute effects of orally administered EGCG (500 mg/kg) on body temperature, activity (transponders), and energy expenditure (indirect calorimetry). RESULTS Dietary supplementation of EGCG resulted in a dose-dependent attenuation of body fat accumulation. Food intake was not affected but faeces energy content was slightly increased by EGCG, indicating a reduced food digestibility and thus reduced long-term energy absorption. Leptin and SCD1 gene expression in white fat was reduced but SCD1 and UCP1 expression in brown fat was not changed. In liver, gene expression of SCD1, ME, and GK was reduced and that of UCP2 increased. Acute oral administration of EGCG over 3 days had no effect on body temperature, activity, and energy expenditure, whereas respiratory quotient during night (activity phase) was decreased, supportive of a decreased lipogenesis and increased fat oxidation. CONCLUSIONS Dietary EGCG attenuated diet-induced body fat accretion in mice. EGCG apparently promoted fat oxidation, but its fat-reducing effect could be entirely explained by its effect in reducing diet digestibility.
Collapse
Affiliation(s)
- S Klaus
- Group of Energy Metabolism, German Institute of Human Nutrition in Potsdam, Nuthetal, Germany.
| | | | | | | |
Collapse
|
41
|
Celis JE, Moreira JMA, Cabezón T, Gromov P, Friis E, Rank F, Gromova I. Identification of extracellular and intracellular signaling components of the mammary adipose tissue and its interstitial fluid in high risk breast cancer patients: toward dissecting the molecular circuitry of epithelial-adipocyte stromal cell interactions. Mol Cell Proteomics 2005; 4:492-522. [PMID: 15695426 DOI: 10.1074/mcp.m500030-mcp200] [Citation(s) in RCA: 184] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
It has become clear that growth and progression of breast tumor cells not only depend on their malignant potential but also on factors present in the tumor microenvironment. Of the cell types that constitute the mammary stroma, the adipocytes are perhaps the least well studied despite the fact that they represent one of the most prominent cell types surrounding the breast tumor cells. There is compelling evidence demonstrating a role for the mammary fat pad in mammary gland development, and some studies have revealed the ability of fat tissue to augment the growth and ability to metastasize of mammary carcinoma cells. Very little is known, however, about which factors adipocytes produce that may orchestrate these actions and how this may come about. In an effort to shed some light on these questions, we present here a detailed proteomic analysis, using two-dimensional gel-based technology, mass spectrometry, immunoblotting, and antibody arrays, of adipose cells and interstitial fluid of fresh fat tissue samples collected from sites topologically distant from the tumors of high risk breast cancer patients that underwent mastectomy and that were not treated prior to surgery. A total of 359 unique proteins were identified, including numerous signaling molecules, hormones, cytokines, and growth factors, involved in a variety of biological processes such as signal transduction and cell communication; energy metabolism; protein metabolism; cell growth and/or maintenance; immune response; transport; regulation of nucleobase, nucleoside, and nucleic acid metabolism; and apoptosis. Apart from providing a comprehensive overview of the mammary fat proteome and its interstitial fluid, the results offer some insight as to the role of adipocytes in the breast tumor microenvironment and provide a first glance of their molecular cellular circuitry. In addition, the results open new possibilities to the study of obesity, which has a strong association with type 2 diabetes, hypertension, and coronary heart disease.
Collapse
Affiliation(s)
- Julio E Celis
- Department of Proteomics in Cancer, Institute of Cancer Biology, Copenhagen University Hospital, DK-2100 Copenhagen, Denmark.
| | | | | | | | | | | | | |
Collapse
|
42
|
Petzke KJ, Friedrich M, Metges CC, Klaus S. Long–term dietary high protein intake up–regulates tissue specific gene expression of uncoupling proteins 1 and 2 in rats. Eur J Nutr 2004; 44:414-21. [PMID: 15602629 DOI: 10.1007/s00394-004-0545-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2004] [Accepted: 11/04/2004] [Indexed: 10/26/2022]
Abstract
BACKGROUND The consequences of chronic high protein (HP) diets are discussed controversially and are not well understood. Rats adapted to HP exposure show an increased amino acid and fat oxidation and lower feed energy efficiency. We hypothesized that the dietary protein level can affect gene expression of uncoupling protein (UCP) homologues which is suggested to be involved in thermogenesis, substrate oxidation, and energy expenditure. AIM OF THE STUDY To assess the mRNA expression of UCP homologues in various tissues of rats fed HP diets and to relate UCP gene expression to various parameters of substrate and energy metabolism. To obtain further indications for the possible involvement of UCP in reducing feed energy efficiency under conditions of HP exposure. METHODS Adult rats were adapted to casein based diets containing either 13.8% (adequate, AP), 25.7% (medium, MP), or 51.3 % (high, HP) crude protein. Rats were fed for 8 wk and killed in the postabsorptive state. Energy expenditure and mRNA expression were measured using indirect calorimetry and Northern blot analysis, respectively. Pearson correlation coefficients were calculated to determine relationships between UCP mRNA expression and metabolic parameters. RESULTS Hepatic UCP2 mRNA expression was increased by MP and HP diets compared to AP diet. In skeletal muscle UCP2 mRNA expression was lowest under MP conditions. UCP1 mRNA expression in brown adipose tissue (BAT) was significantly increased by HP exposure. The values were inversely associated with feed energy efficiency and positively with energy expenditure and oxygen consumption in the dark period. Skeletal muscle UCP2 and -3 mRNA expression strongly correlated with the plasma free fatty acid concentration, whereas BAT UCP1 and hepatic UCP2 gene expression did not. CONCLUSIONS Our results indicate that hepatic UCP2 and BAT UCP1 mRNA expression is related to the level of dietary protein intake. This suggests a role of UCPs in substrate oxidation and in thermogenesis under conditions of HP exposure.
Collapse
Affiliation(s)
- Klaus J Petzke
- German Institute of Human Nutrition, Potsdam-Rehbrücke (DIfE), 14558 Nuthetal, Germany.
| | | | | | | |
Collapse
|
43
|
Abstract
The kinship theory of genomic imprinting proposes that parent-specific gene expression evolves at a locus because a gene's level of expression in one individual has fitness effects on other individuals who have different probabilities of carrying the maternal and paternal alleles of the individual in which the gene is expressed. Therefore, natural selection favors different levels of expression depending on an allele's sex-of-origin in the previous generation. This review considers the strength of evidence in support of this hypothesis for imprinted genes in four "clusters," associated with the imprinted loci Igf2, Igf2r, callipyge, and Gnas. The clusters associated with Igf2 and Igf2r both contain paternally expressed transcripts that act as enhancers of prenatal growth and maternally expressed transcripts that act as inhibitors of prenatal growth. This is consistent with predictions of the kinship theory. However, the clusters also contain imprinted genes whose phenotypes as yet remain unexplained by the theory. The principal effects of imprinted genes in the callipyge and Gnas clusters appear to involve lipid and energy metabolism. The kinship theory predicts that maternally expressed transcripts will favor higher levels of nonshivering thermogenesis (NST) in brown adipose tissue (BAT) of animals that huddle for warmth as offspring. The phenotypes of reciprocal heterozygotes for Gnas knockouts provide provisional support for this hypothesis, as does some evidence from other imprinted genes (albeit more tentatively). The diverse effects of imprinted genes on the development of white adipose tissue (WAT) have so far defied a unifying hypothesis in terms of the kinship theory.
Collapse
Affiliation(s)
- David Haig
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
| |
Collapse
|
44
|
Mercke P, Kappers IF, Verstappen FWA, Vorst O, Dicke M, Bouwmeester HJ. Combined transcript and metabolite analysis reveals genes involved in spider mite induced volatile formation in cucumber plants. PLANT PHYSIOLOGY 2004; 135:2012-24. [PMID: 15310834 PMCID: PMC520772 DOI: 10.1104/pp.104.048116] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2004] [Revised: 06/25/2004] [Accepted: 06/27/2004] [Indexed: 05/17/2023]
Abstract
Many plants have an indirect defense against herbivores by emitting volatiles that attract carnivorous enemies of the herbivores. In cucumber (Cucumis sativus) the production of carnivore attractants can be induced by herbivory or jasmonic acid spraying. From the leaves of cucumber plants with and without spider mite infestation, two subtractive cDNA libraries were made that were enriched in cDNA fragments up- or down-regulated by spider mite infestation. A total of 713 randomly selected clones from these libraries were used to make a cDNA microarray. Subsequently, cucumber plants were sprayed with jasmonic acid, mechanically damaged, infested with spider mites, or left untreated (control). Leaf samples were taken at a range of different time points, and induced volatile compounds and mRNA (from the same leaves) were collected. cDNAs prepared from the mRNA were hybridized to the clones on the microarray. The resulting gene expression profiles were analyzed in combination with volatile production data in order to gain insight in the possible involvement of the studied genes in the synthesis of those volatiles. The clones on the microarray and the induced cucumber volatiles could be grouped into a number of clusters in which specific biosynthetic genes clustered with the product of that pathway. For example, lipoxygenase cDNA clones clustered with the volatile (Z)-3-hexenyl acetate and the volatile sesquiterpene (E,E)- alpha-farnesene clustered with an up-regulated sesquiterpene synthase fragment. This fragment was used to screen a cDNA library which resulted in the cloning of the cucumber (E,E)-alpha-farnesene and (E)-beta-caryophyllene synthases. The use of combined global gene expression analysis and metabolite analysis for the discovery of genes involved in specific biosynthetic processes is discussed.
Collapse
Affiliation(s)
- Per Mercke
- Plant Research International, 6700 AA Wageningen, The Netherlands
| | | | | | | | | | | |
Collapse
|
45
|
Yoo H, Stephanopoulos G, Kelleher JK. Quantifying carbon sources for de novo lipogenesis in wild-type and IRS-1 knockout brown adipocytes. J Lipid Res 2004; 45:1324-32. [PMID: 15102881 DOI: 10.1194/jlr.m400031-jlr200] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Studies were conducted to evaluate the flux of various carbon sources to lipogenesis during brown adipocyte differentiation. (13)C labeling and isotopomer spectral analysis quantified the contribution of metabolites to de novo lipogenesis in wild-type (WT) and insulin receptor substrate-1 knockout (KO) brown adipocytes. Both glucose (Glc) and glutamine (Gln) provided substantial fractions of the lipogenic acetyl CoA for both WT and KO cells in standard media, together contributing 60%. Adding acetoacetate (AcAc; 10 mM) to the medium resulted in a large flux of AcAc to lipid, representing 70% of the lipogenic acetyl CoA and decreasing the contribution of Glc plus Gln to 30%. For WT cells, the fractional synthesis of new fatty acids during 4 days of differentiation was 80% of the total. Similarly, 80% of the lipidic glycerol was derived from Glc in the medium; Gln was not a precursor for glycerol. When Gln was removed from the medium, the contribution of Glc to fatty acid synthesis doubled, replacing most of the contribution of Gln and maintaining total lipogenesis. Conversely, removal of Glc dramatically decreased lipogenesis. These results indicate that Glc's distinct role in lipid synthesis during differentiation cannot be replaced by other carbon sources, consistent with the role of Glc supplying NADPH and/or glycerol for triglyceride synthesis.
Collapse
Affiliation(s)
- Hyuntae Yoo
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | | | | |
Collapse
|
46
|
Unami A, Shinohara Y, Kajimoto K, Baba Y. Comparison of gene expression profiles between white and brown adipose tissues of rat by microarray analysis. Biochem Pharmacol 2004; 67:555-64. [PMID: 15037207 DOI: 10.1016/j.bcp.2003.09.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2003] [Accepted: 09/04/2003] [Indexed: 11/29/2022]
Abstract
To characterize the energy metabolism in brown adipose tissue (BAT), the differences in gene expression profiles between BAT and white adipose tissue (WAT) were analyzed using a high-density cDNA microarray. RNAs isolated from two adipose tissues were hybridized to an Agilent rat cDNA Microarray that contained about 14,500 cDNA probe sets. The expression levels of 499 cDNA/ESTs were found to be at least 5-fold higher or lower in BAT than in WAT. Consistent with our previous findings, high expression levels of genes encoding uncoupling protein 1, muscle-type carnitine palmitoyltransferase and some other proteins involved in energy metabolism in BAT were found. Most of the genes encoding mitochondrial proteins, such as subunits of ATP synthase, cytochrome c oxidase, and NADH dehydrogenase, were highly expressed, reflecting possible differences in the cellular content of mitochondria between BAT and WAT. However, the expression levels of several genes encoding mitochondrial protein, such as liver mitochondrial aldehyde dehydrogenase and dicarboxylate carrier, were remarkably lower in BAT. These results may give important clues to understand the unique energy metabolism in BAT.
Collapse
Affiliation(s)
- Akira Unami
- Faculty of Pharmaceutical Sciences, The University of Tokushima, Japan.
| | | | | | | |
Collapse
|
47
|
Urs S, Smith C, Campbell B, Saxton AM, Taylor J, Zhang B, Snoddy J, Jones Voy B, Moustaid-Moussa N. Gene expression profiling in human preadipocytes and adipocytes by microarray analysis. J Nutr 2004; 134:762-70. [PMID: 15051823 DOI: 10.1093/jn/134.4.762] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Uncontrolled expansion of adipose tissue leads to obesity, a public health epidemic affecting >30% of adult Americans. Adipose mass increases in part through the recruitment and differentiation of an existing pool of preadipocytes (PA) into adipocytes (AD). Most studies investigating adipogenesis used primarily murine cell lines; much less is known about the relevant processes that occur in humans. Therefore, characterization of genes associated with adipocyte development is key to understanding the pathogenesis of obesity and developing treatments for this disorder. To address this issue, we performed large-scale analyses of human adipose gene expression using microarray technology. Differential gene expression between PA and AD was analyzed in 6 female patients using human cDNA microarray slides and data analyzed using the Stanford Microarray Database. Statistical analysis for the gene expression was performed using the SAS mixed models. Compared with PA, several genes involved in lipid metabolism were overexpressed in AD, including fatty acid binding protein, adipose differentiation-related protein, lipoprotein lipase, perilipin, and adipose most abundant transcript 1. Novel genes expressed in adipocytes included E2F5 transcriptional factor and SMARC (SWI/SNF-related, matrix associated, actin-dependent regulator of chromatin). PA predominantly expressed genes encoding extracellular matrix components such as fibronectin, matrix metalloprotein, and novel proteins such as lysyl oxidase. Despite the high differential expression of some of these genes, many did not differ significantly likely due to high variability and limited statistical power. A comprehensive list of differential gene expression is presented according to cellular function. In conclusion, these studies offer an overview of the gene expression profiles in PA and AD and identify new genes with potentially important functions in adipose tissue development and obesity that merit further investigation.
Collapse
Affiliation(s)
- Sumithra Urs
- Department of Nutrition,The University of Tennessee, Knoxville, TN 37996-1920, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
48
|
Abstract
The function of brown adipose tissue is to transfer energy from food into heat; physiologically, both the heat produced and the resulting decrease in metabolic efficiency can be of significance. Both the acute activity of the tissue, i.e., the heat production, and the recruitment process in the tissue (that results in a higher thermogenic capacity) are under the control of norepinephrine released from sympathetic nerves. In thermoregulatory thermogenesis, brown adipose tissue is essential for classical nonshivering thermogenesis (this phenomenon does not exist in the absence of functional brown adipose tissue), as well as for the cold acclimation-recruited norepinephrine-induced thermogenesis. Heat production from brown adipose tissue is activated whenever the organism is in need of extra heat, e.g., postnatally, during entry into a febrile state, and during arousal from hibernation, and the rate of thermogenesis is centrally controlled via a pathway initiated in the hypothalamus. Feeding as such also results in activation of brown adipose tissue; a series of diets, apparently all characterized by being low in protein, result in a leptin-dependent recruitment of the tissue; this metaboloregulatory thermogenesis is also under hypothalamic control. When the tissue is active, high amounts of lipids and glucose are combusted in the tissue. The development of brown adipose tissue with its characteristic protein, uncoupling protein-1 (UCP1), was probably determinative for the evolutionary success of mammals, as its thermogenesis enhances neonatal survival and allows for active life even in cold surroundings.
Collapse
Affiliation(s)
- Barbara Cannon
- The Wenner-Gren Institute, The Arrhenius Laboratories F3, Stockholm University, Stockholm, Sweden
| | | |
Collapse
|
49
|
Affiliation(s)
- Susanne Klaus
- German Institute of Human Nutrition in Potsdam, Bergholz-Rehbrücke, Germany.
| | | |
Collapse
|
50
|
Metges CC, Lehmann L, Boeuf S, Petzke KJ, Müller A, Rickert R, Franke W, Steinhart H, Nürnberg G, Klaus S. cis-9,trans-11 and trans-10,cis-12 CLA affect lipid metabolism differently in primary white and brown adipocytes of djungarian hamsters. Lipids 2003; 38:1133-42. [PMID: 14733358 DOI: 10.1007/s11745-003-1171-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We explored whether CLA isomers and other C18 FA affect (i) lipid content and FA concentrations in total adipocyte lipids, (ii) FA synthesis from glucose in TAG and phospholipids of primary brown (BAT) and white adipocytes (WAT), and (iii) mRNA expression of uncoupling protein 1 (UCP1) in primary brown adipocytes of Djungarian hamsters (Phodopus sungorus). c9,t11-CLA, oleic, linoleic, and alpha-linolenic acid increased whereas t10,c12-CLA decreased lipid accumulation in both adipocyte types. t10,c12-CLA treatment affected FA composition mainly in BAT cells. CLA incorporation into lipids, in particular c9,t11-CLA, was higher in BAT. In both cell types, t10,c12-CLA treatment reduced the incorporation of glucose 13C carbon into FA of TAG and phospholipids, whereas c9,t11-CLA, linoleic, and alpha-linolenic acid either did not influence or dose-dependently increased glucose carbon incorporation into FA. UCP1 mRNA expression was inhibited by t10,c12-CLA but increased by c9,t11-CLA, linoleic, and alpha-linolenic acid. It is concluded that c9,t11-CLA and t10,c12-CLA have distinctly different effects on lipid metabolism in primary adipocytes. The effects of c9,t11-CLA are similar to those of other unsaturated C18 FA. The opposite effects of c9,t11-CLA and t10,c12-CLA are evident in both WAT and BAT cultures; however, brown adipocytes seem to be more susceptible to CLA treatment.
Collapse
Affiliation(s)
- Cornelia C Metges
- German Institute of Human Nutrition, 14558 Bergholz-Rehbrücke, Germany.
| | | | | | | | | | | | | | | | | | | |
Collapse
|