1
|
Perez-Leighton C, Kerr B, Scherer PE, Baudrand R, Cortés V. The interplay between leptin, glucocorticoids, and GLP1 regulates food intake and feeding behaviour. Biol Rev Camb Philos Soc 2024; 99:653-674. [PMID: 38072002 DOI: 10.1111/brv.13039] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 11/21/2023] [Accepted: 12/01/2023] [Indexed: 05/09/2024]
Abstract
Nutritional, endocrine, and neurological signals converge in multiple brain centres to control feeding behaviour and food intake as part of the allostatic regulation of energy balance. Among the several neuroendocrine systems involved, the leptin, glucocorticoid, and glucagon-like peptide 1 (GLP1) systems have been extensively researched. Leptin is at the top hierarchical level since its complete absence is sufficient to trigger severe hyperphagia. Glucocorticoids are key regulators of the energy balance adaptation to stress and their sustained excess leads to excessive adiposity and metabolic perturbations. GLP1 participates in metabolic adaptation to food intake, regulating insulin secretion and satiety by parallel central and peripheral signalling systems. Herein, we review the brain and peripheral targets of these three hormone systems that integrate to regulate food intake, feeding behaviour, and metabolic homeostasis. We examine the functional relationships between leptin, glucocorticoids, and GLP1 at the central and peripheral levels, including the cross-regulation of their circulating levels and their cooperative or antagonistic actions at different brain centres. The pathophysiological roles of these neuroendocrine systems in dysregulated intake are explored in the two extremes of body adiposity - obesity and lipodystrophy - and eating behaviour disorders.
Collapse
Affiliation(s)
- Claudio Perez-Leighton
- Departmento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Av. Libertador Bernardo O'Higgins 340, Santiago, 830024, Chile
| | - Bredford Kerr
- Centro de Biología Celular y Biomedicina-CEBICEM, Facultad de Medicina y Ciencia, Universidad San Sebastián, Carmen Sylva 2444, Providencia, Santiago, Chile
| | - Philipp E Scherer
- Touchstone Diabetes Center, The University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390, USA
| | - René Baudrand
- Departmento de Endocrinología, Facultad de Medicina, Pontificia Universidad Católica de Chile, Av. Libertador Bernardo O'Higgins 340, Santiago, 830024, Chile
- Centro Translacional de Endocrinología (CETREN), Facultad de Medicina, Pontificia Universidad Católica de Chile, Av. Libertador Bernardo O'Higgins 340, Santiago, 830024, Chile
| | - Víctor Cortés
- Departmento de Nutrición, Diabetes y Metabolismo, Facultad de Medicina, Pontificia Universidad Católica de Chile, Av. Libertador Bernardo O'Higgins 340, Santiago, 830024, Chile
| |
Collapse
|
2
|
Kalusche W, Case C, Taylor E. Leptin antagonism attenuates hypertension and renal injury in an experimental model of autoimmune disease. Clin Sci (Lond) 2023; 137:1771-1785. [PMID: 38031726 PMCID: PMC10721433 DOI: 10.1042/cs20230924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 11/25/2023] [Accepted: 11/29/2023] [Indexed: 12/01/2023]
Abstract
Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder that is characterized by B- and T-lymphocyte dysfunction and altered cytokine production, including elevated levels of the adipocytokine leptin. Leptin has various immunomodulatory properties, including promoting the expansion of proinflammatory T lymphocytes and the proliferation and survival of B cells. In the present study, we hypothesized that leptin antagonism would improve B- and T-cell dysfunction and attenuate hypertension in an experimental model of SLE, the NZBWF1 mouse. To test this hypothesis, 28-week-old female control and SLE mice were administered 5 mg/kg of murine leptin superantagonist (LA) or vehicle via ip injection every other day for four weeks. Analysis of peripheral blood immune cell populations showed no changes in total CD45R+ B and CD3+ T cell percentages after treatment with LA. However, SLE mice treated with LA had an improved CD4/CD8 ratio and decreased CD3+CD4-CD8- double negative (DN) T cells. Blood pressure was higher in SLE than in control, and treatment with LA decreased blood pressure in SLE mice. Treatment with LA also delayed the onset of albuminuria and decreased glomerulosclerosis in SLE mice. Renal immune cell infiltration was significantly higher in SLE mice as compared with control, but LA treatment was associated with decreased levels of renal CD4+ T cells. In conclusion, these data suggest that leptin plays a pathogenic role in the development of hypertension in SLE, in part, by promoting the expansion of inflammatory DN T cells and the infiltration of T cells into the kidneys.
Collapse
Affiliation(s)
- William J. Kalusche
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS 39216, U.S.A
| | - Clinton T. Case
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS 39216, U.S.A
| | - Erin B. Taylor
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS 39216, U.S.A
| |
Collapse
|
3
|
Laget J, Cortijo I, Boukhaled JH, Muyor K, Duranton F, Jover B, Raynaud F, Lajoix AD, Argilés À, Gayrard N. Cafeteria Diet-Induced Obesity Worsens Experimental CKD. Nutrients 2023; 15:3331. [PMID: 37571269 PMCID: PMC10421241 DOI: 10.3390/nu15153331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 07/20/2023] [Accepted: 07/21/2023] [Indexed: 08/13/2023] Open
Abstract
Obesity is a significant risk factor for chronic kidney disease (CKD). This study aimed to evaluate the impact of obesity on the development of kidney fibrosis in a model of cafeteria diet rats undergoing 5/6th nephrectomy (SNx). Collagen 1, 3, and 4 expression, adipocyte size, macrophage number, and the expression of 30 adipokines were determined. Collagen 1 expression in kidney tissue was increased in Standard-SNx and Cafeteria-SNx (7.1 ± 0.6% and 8.9 ± 0.9 tissue area, respectively). Renal expression of collagen 3 and 4 was significantly increased (p < 0.05) in Cafeteria-SNx (8.6 ± 1.5 and 10.9 ± 1.9% tissue area, respectively) compared to Cafeteria (5.2 ± 0.5 and 6.3 ± 0.6% tissue area, respectively). Adipocyte size in eWAT was significantly increased by the cafeteria diet. In Cafeteria-SNx, we observed a significant increase in macrophage number in the kidney (p = 0.01) and a consistent tendency in eWAT. The adipokine level was higher in the Cafeteria groups. Interleukin 11, dipeptidyl peptidase 4, and serpin 1 were increased in Cafeteria-SNx. In the kidney, collagen 3 and 4 expressions and the number of macrophages were increased in Cafeteria-SNx, suggesting an exacerbation by preexisting obesity of CKD-induced renal inflammation and fibrosis. IL11, DPP4, and serpin 1 can act directly on fibrosis and participate in the observed worsening CKD.
Collapse
Affiliation(s)
- Jonas Laget
- RD-Néphrologie, 34090 Montpellier, France; (J.L.); (I.C.); (J.H.B.); (K.M.); (F.D.); (B.J.); (À.A.)
| | - Irene Cortijo
- RD-Néphrologie, 34090 Montpellier, France; (J.L.); (I.C.); (J.H.B.); (K.M.); (F.D.); (B.J.); (À.A.)
| | - Juliana H. Boukhaled
- RD-Néphrologie, 34090 Montpellier, France; (J.L.); (I.C.); (J.H.B.); (K.M.); (F.D.); (B.J.); (À.A.)
| | - Karen Muyor
- RD-Néphrologie, 34090 Montpellier, France; (J.L.); (I.C.); (J.H.B.); (K.M.); (F.D.); (B.J.); (À.A.)
| | - Flore Duranton
- RD-Néphrologie, 34090 Montpellier, France; (J.L.); (I.C.); (J.H.B.); (K.M.); (F.D.); (B.J.); (À.A.)
| | - Bernard Jover
- RD-Néphrologie, 34090 Montpellier, France; (J.L.); (I.C.); (J.H.B.); (K.M.); (F.D.); (B.J.); (À.A.)
| | - Fabrice Raynaud
- PhyMedExp, INSERM, CNRS, Université de Montpellier, 34090 Montpellier, France;
| | - Anne-Dominique Lajoix
- Biocommunication in Cardio-Metabolism (BC2M), University of Montpellier, 34090 Montpellier, France;
| | - Àngel Argilés
- RD-Néphrologie, 34090 Montpellier, France; (J.L.); (I.C.); (J.H.B.); (K.M.); (F.D.); (B.J.); (À.A.)
| | - Nathalie Gayrard
- RD-Néphrologie, 34090 Montpellier, France; (J.L.); (I.C.); (J.H.B.); (K.M.); (F.D.); (B.J.); (À.A.)
| |
Collapse
|
4
|
Herzl E, Schmitt EE, Shearrer G, Keith JF. The Effects of a Western Diet vs. a High-Fiber Unprocessed Diet on Health Outcomes in Mice Offspring. Nutrients 2023; 15:2858. [PMID: 37447184 DOI: 10.3390/nu15132858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 06/16/2023] [Accepted: 06/21/2023] [Indexed: 07/15/2023] Open
Abstract
Diet influences critical periods of growth, including gestation and early development. We hypothesized that a maternal/early life diet reflecting unprocessed dietary components would positively affect offspring metabolic and anthropometric parameters. Using 9 C57BL-6 dams, we simulated exposure to a Western diet, a high-fiber unprocessed diet (HFUD), or a control diet. The dams consumed their respective diets (Western [n = 3], HFUD [n = 3], and control [n = 3]) through 3 weeks of pregnancy and 3 weeks of weaning; their offspring consumed the diet of their mother for 4.5 weeks post weaning. Measurements included dual X-ray absorptiometry (DEXA) scans, feed consumption, body weight, blood glucose, and insulin and glycated hemoglobin (HbA1c) in the offspring. Statistical analyses included one-way ANOVA with Tukey's post hoc analysis. The offspring DEXA measures at 5 and 7.5 weeks post parturition revealed higher lean body mass development in the HFUD and control diet offspring compared to the Western diet offspring. An analysis indicated that blood glucose (p = 0.001) and HbA1c concentrations (p = 0.002) were lower among the HFUD offspring compared to the Western and control offspring. The results demonstrate that diet during gestation and early life consistent with traditional diet patterns may influence hyperglycemia and adiposity in offspring.
Collapse
Affiliation(s)
- Elizabeth Herzl
- Department of Family & Consumer Sciences, University of Wyoming, Laramie, WY 82071, USA
| | - Emily E Schmitt
- Division of Kinesiology & Health, University of Wyoming, Laramie, WY 82071, USA
- WWAMI Medical Education, University of Wyoming, Laramie, WY 82071, USA
| | - Grace Shearrer
- Department of Family & Consumer Sciences, University of Wyoming, Laramie, WY 82071, USA
- WWAMI Medical Education, University of Wyoming, Laramie, WY 82071, USA
| | - Jill F Keith
- Department of Family & Consumer Sciences, University of Wyoming, Laramie, WY 82071, USA
| |
Collapse
|
5
|
Fryklund C, Neuhaus M, Morén B, Borreguero-Muñoz A, Lundmark R, Stenkula KG. Expansion of the Inguinal Adipose Tissue Depot Correlates With Systemic Insulin Resistance in C57BL/6J Mice. Front Cell Dev Biol 2022; 10:942374. [PMID: 36158197 PMCID: PMC9489915 DOI: 10.3389/fcell.2022.942374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 06/21/2022] [Indexed: 11/13/2022] Open
Abstract
To accommodate surplus energy, the adipose tissue expands by increasing adipocyte size (hypertrophy) and number (hyperplasia). The presence of hypertrophic adipocytes is a key characteristic of adipose tissue dysfunction. High-fat diet (HFD) fed C57BL/6J mice are a commonly used model to study obesity and obesity-related complications. In the present study, we have characterized adipose plasticity, at both the cellular and tissue level, by examining the temporal development of systemic insulin resistance and adiposity in response to HFD-feeding for 4, 8, and 12 weeks (4w, 8w, and 12w). Within the same time frame, we examined systemic metabolic flexibility and adipose plasticity when switching from HFD- to chow-diet during the last 2 weeks of diet intervention (referred to as the reverse (REV) group: 4wREV (2w HFD+2w chow), 8wREV (6w HFD+2w chow), 12wREV (10w HFD+2w chow)). In response to HFD-feeding over time, the 12w group had impaired systemic insulin sensitivity compared to both the 4w and 8w groups, accompanied by an increase in hypertrophic inguinal adipocytes and liver triglycerides. After reversing from HFD- to chow-feeding, most parameters were completely restored to chow control levels for 4wREV and 8wREV groups. In contrast, the 12wREV group had a significantly increased number of hypertrophic adipocytes, liver triglycerides accumulation, and impaired systemic insulin sensitivity compared to chow-fed mice. Further, image analysis at the single-cell level revealed a cell-size dependent organization of actin filaments for all feeding conditions. Indeed, the impaired adipocyte size plasticity in the 12wREV group was accompanied by increased actin filamentation and reduced insulin-stimulated glucose uptake compared with chow-fed mice. In summary, these results demonstrate that the C57BL/6J HFD-feeding model has a large capacity to restore adipocyte cell size and systemic insulin sensitivity, and that a metabolic tipping point occurs between 8 and 12w of HFD-feeding where this plasticity deteriorates. We believe these findings provide substantial understanding of C57BL/6J mice as an obesity model, and that an increased pool of hypertrophic ING adipocytes could contribute to aggravated insulin resistance.
Collapse
Affiliation(s)
- Claes Fryklund
- Department of Experimental Medical Science, Lund University, Lund, Sweden
- *Correspondence: Claes Fryklund,
| | - Mathis Neuhaus
- Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Björn Morén
- Department of Experimental Medical Science, Lund University, Lund, Sweden
- Integrative Medical Biology, Umeå University, Umeå, Sweden
| | | | | | - Karin G. Stenkula
- Department of Experimental Medical Science, Lund University, Lund, Sweden
| |
Collapse
|
6
|
Sodhi RK, Singh R, Bansal Y, Bishnoi M, Parhar I, Kuhad A, Soga T. Intersections in Neuropsychiatric and Metabolic Disorders: Possible Role of TRPA1 Channels. Front Endocrinol (Lausanne) 2021; 12:771575. [PMID: 34912298 PMCID: PMC8666658 DOI: 10.3389/fendo.2021.771575] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 11/04/2021] [Indexed: 11/25/2022] Open
Abstract
Neuropsychiatric disorders (NPDs) are a huge burden to the patient, their family, and society. NPDs have been greatly associated with cardio-metabolic comorbidities such as obesity, type-2 diabetes mellitus, dysglycaemia, insulin resistance, dyslipidemia, atherosclerosis, and other cardiovascular disorders. Antipsychotics, which are frontline drugs in the treatment of schizophrenia and off-label use in other NPDs, also add to this burden by causing severe metabolic perturbations. Despite decades of research, the mechanism deciphering the link between neuropsychiatric and metabolic disorders is still unclear. In recent years, transient receptor potential Ankyrin 1 (TRPA1) channel has emerged as a potential therapeutic target for modulators. TRPA1 agonists/antagonists have shown efficacy in both neuropsychiatric disorders and appetite regulation and thus provide a crucial link between both. TRPA1 channels are activated by compounds such as cinnamaldehyde, allyl isothiocyanate, allicin and methyl syringate, which are present naturally in food items such as cinnamon, wasabi, mustard, garlic, etc. As these are present in many daily food items, it could also improve patient compliance and reduce the patients' monetary burden. In this review, we have tried to present evidence of the possible involvement of TRPA1 channels in neuropsychiatric and metabolic disorders and a possible hint towards using TRPA1 modulators to target appetite, lipid metabolism, glucose and insulin homeostasis and inflammation associated with NPDs.
Collapse
Affiliation(s)
- Rupinder Kaur Sodhi
- Pharmacology Research Laboratory, University Institute of Pharmaceutical Sciences, University Grants Commission, Center of Advanced Studies (UGC-CAS), Panjab University, Chandigarh, India
| | - Raghunath Singh
- Schizophrenia Division, Centre for Addiction and Mental Health (CAMH), Toronto, ON, Canada
| | - Yashika Bansal
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health (CAMH), Toronto, ON, Canada
| | - Mahendra Bishnoi
- TR(i)P for Health Laboratory, Centre of Excellence in Functional Foods, Department of Food and Nutritional Biotechnology, National Agri-Food Biotechnology Institute (NABI), Punjab, India
| | - Ishwar Parhar
- Brain Research Institute Monash Sunway (BRIMS), Jeffrey Cheah School of Medicine and Health Science, Monash University Malaysia, Bandar Sunway, Malaysia
| | - Anurag Kuhad
- Pharmacology Research Laboratory, University Institute of Pharmaceutical Sciences, University Grants Commission, Center of Advanced Studies (UGC-CAS), Panjab University, Chandigarh, India
- *Correspondence: Anurag Kuhad, ; Tomoko Soga,
| | - Tomoko Soga
- Brain Research Institute Monash Sunway (BRIMS), Jeffrey Cheah School of Medicine and Health Science, Monash University Malaysia, Bandar Sunway, Malaysia
- *Correspondence: Anurag Kuhad, ; Tomoko Soga,
| |
Collapse
|
7
|
Guerra-Cantera S, Frago LM, Collado-Pérez R, Canelles S, Ros P, Freire-Regatillo A, Jiménez-Hernaiz M, Barrios V, Argente J, Chowen JA. Sex Differences in Metabolic Recuperation After Weight Loss in High Fat Diet-Induced Obese Mice. Front Endocrinol (Lausanne) 2021; 12:796661. [PMID: 34975768 PMCID: PMC8716724 DOI: 10.3389/fendo.2021.796661] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Accepted: 11/16/2021] [Indexed: 01/10/2023] Open
Abstract
Dietary intervention is a common tactic employed to curtail the current obesity epidemic. Changes in nutritional status alter metabolic hormones such as insulin or leptin, as well as the insulin-like growth factor (IGF) system, but little is known about restoration of these parameters after weight loss in obese subjects and if this differs between the sexes, especially regarding the IGF system. Here male and female mice received a high fat diet (HFD) or chow for 8 weeks, then half of the HFD mice were changed to chow (HFDCH) for 4 weeks. Both sexes gained weight (p < 0.001) and increased their energy intake (p < 0.001) and basal glycemia (p < 0.5) on the HFD, with these parameters normalizing after switching to chow but at different rates in males and females. In both sexes HFD decreased hypothalamic NPY and AgRP (p < 0.001) and increased POMC (p < 0.001) mRNA levels, with all normalizing in HFDCH mice, whereas the HFD-induced decrease in ObR did not normalize (p < 0.05). All HFD mice had abnormal glucose tolerance tests (p < 0.001), with males clearly more affected, that normalized when returned to chow. HFD increased insulin levels and HOMA index (p < 0.01) in both sexes, but only HFDCH males normalized this parameter. Returning to chow normalized the HFD-induced increase in circulating leptin (p < 0.001), total IGF1 (p < 0.001), IGF2 (p < 0.001, only in females) and IGFBP3 (p < 0.001), whereas free IGF1 levels remained elevated (p < 0.01). In males IGFBP2 decreased with HFD and normalized with chow (p < 0.001), with no changes in females. Although returning to a healthy diet improved of most metabolic parameters analyzed, fIGF1 levels remained elevated and hypothalamic ObR decreased in both sexes. Moreover, there was sex differences in both the response to HFD and the switch to chow including circulating levels of IGF2 and IGFBP2, factors previously reported to be involved in glucose metabolism. Indeed, glucose metabolism was also differentially modified in males and females, suggesting that these observations could be related.
Collapse
Affiliation(s)
- Santiago Guerra-Cantera
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Madrid, Spain
- Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
| | - Laura M. Frago
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Madrid, Spain
- Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
| | - Roberto Collado-Pérez
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Madrid, Spain
- Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, Spain
| | - Sandra Canelles
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Madrid, Spain
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
| | - Purificación Ros
- Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, Spain
- Department of Pediatrics, Hospital Universitario Puerta de Hierro-Majadahonda, Madrid, Spain
| | - Alejandra Freire-Regatillo
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Madrid, Spain
- Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
| | - María Jiménez-Hernaiz
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Madrid, Spain
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
| | - Vicente Barrios
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Madrid, Spain
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
| | - Jesús Argente
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Madrid, Spain
- Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
- IMDEA Food Institute, CEI UAM + CSIC, Madrid, Spain
- *Correspondence: Julie A. Chowen, ; Jesús Argente,
| | - Julie A. Chowen
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Madrid, Spain
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
- IMDEA Food Institute, CEI UAM + CSIC, Madrid, Spain
- *Correspondence: Julie A. Chowen, ; Jesús Argente,
| |
Collapse
|
8
|
Kořínková L, Pražienková V, Černá L, Karnošová A, Železná B, Kuneš J, Maletínská L. Pathophysiology of NAFLD and NASH in Experimental Models: The Role of Food Intake Regulating Peptides. Front Endocrinol (Lausanne) 2020; 11:597583. [PMID: 33324348 PMCID: PMC7726422 DOI: 10.3389/fendo.2020.597583] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 10/28/2020] [Indexed: 12/12/2022] Open
Abstract
Obesity, diabetes, insulin resistance, sedentary lifestyle, and Western diet are the key factors underlying non-alcoholic fatty liver disease (NAFLD), one of the most common liver diseases in developed countries. In many cases, NAFLD further progresses to non-alcoholic steatohepatitis (NASH), fibrosis, cirrhosis, and to hepatocellular carcinoma. The hepatic lipotoxicity and non-liver factors, such as adipose tissue inflammation and gastrointestinal imbalances were linked to evolution of NAFLD. Nowadays, the degree of adipose tissue inflammation was shown to directly correlate with the severity of NAFLD. Consumption of higher caloric intake is increasingly emerging as a fuel of metabolic inflammation not only in obesity-related disorders but also NAFLD. However, multiple causes of NAFLD are the reason why the mechanisms of NAFLD progression to NASH are still not well understood. In this review, we explore the role of food intake regulating peptides in NAFLD and NASH mouse models. Leptin, an anorexigenic peptide, is involved in hepatic metabolism, and has an effect on NAFLD experimental models. Glucagon-like peptide-1 (GLP-1), another anorexigenic peptide, and GLP-1 receptor agonists (GLP-1R), represent potential therapeutic agents to prevent NAFLD progression to NASH. On the other hand, the deletion of ghrelin, an orexigenic peptide, prevents age-associated hepatic steatosis in mice. Because of the increasing incidence of NAFLD and NASH worldwide, the selection of appropriate animal models is important to clarify aspects of pathogenesis and progression in this field.
Collapse
Affiliation(s)
- L. Kořínková
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czechia
| | - V. Pražienková
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czechia
| | - L. Černá
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czechia
| | - A. Karnošová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czechia
| | - B. Železná
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czechia
| | - J. Kuneš
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czechia
- Institute of Physiology, Czech Academy of Sciences, Prague, Czechia
| | - Lenka Maletínská
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czechia
| |
Collapse
|
9
|
Braga SP, Delanogare E, Machado AE, Prediger RD, Moreira ELG. Switching from high-fat feeding (HFD) to regular diet improves metabolic and behavioral impairments in middle-aged female mice. Behav Brain Res 2020; 398:112969. [PMID: 33075395 DOI: 10.1016/j.bbr.2020.112969] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Revised: 09/18/2020] [Accepted: 10/10/2020] [Indexed: 12/30/2022]
Abstract
Obesity represents a risk factor for metabolic syndrome and cardiovascular and psychiatric disorders. Excessive caloric intake, particularly in dietary fats, is an environmental factor that contributes to obesity development. Thus, the observation that switching from long-standing dietary obesity to standard diet (SD) can ameliorate the high-fat diet-induced metabolic, memory, and emotionality-related impairments are particularly important. Herein we investigated whether switching from the high-fat diet (HFD) to SD could improve the metabolic and behavioral impairments observed in middle-aged females C57Bl/6 mice. During twelve weeks, the animals received a high-fat diet (61 % fat) or SD diet. After 12-weeks, the HFD group's diet was switched to SD for an additional four weeks. It was observed a progressive deleterious effect of HFD in metabolic and behavioral parameters in mice. After four weeks of HFD-feeding, the animals showed glucose intolerance and increased locomotor activity. A subsequent increase in the body mass gain, hyperglycemia, and depressive-like behavior was observed after eight weeks, and memory impairments after twelve weeks. After replacing the HFD to SD, it was observed an improvement of metabolic (loss of body mass, normal plasma glucose levels, and glucose tolerance) and behavioral (absence of memory and emotional alterations) parameters. These results demonstrate the temporal development of metabolic and behavioral impairments following HFD in middle-age female mice and provide new evidence that these alterations can be improved by switching back the diet to SD.
Collapse
Affiliation(s)
- Sara Pereira Braga
- Programa Multicêntrico de Pós-Graduação em Ciências Fisiológicas, Universidade Federal de Santa Catarina, 88040-900, Florianópolis, SC, Brazil
| | - Eslen Delanogare
- Programa de Pós-Graduação em Neurociências, Universidade Federal de Santa Catarina, 88040-900, Florianópolis, SC, Brazil
| | - Adriano Emanuel Machado
- Programa de Pós-Graduação em Neurociências, Universidade Federal de Santa Catarina, 88040-900, Florianópolis, SC, Brazil
| | - Rui Daniel Prediger
- Programa de Pós-Graduação em Neurociências, Universidade Federal de Santa Catarina, 88040-900, Florianópolis, SC, Brazil; Departamento de Farmacologia, Universidade Federal de Santa Catarina, 88040-900, Florianópolis, SC, Brazil
| | - Eduardo Luiz Gasnhar Moreira
- Programa Multicêntrico de Pós-Graduação em Ciências Fisiológicas, Universidade Federal de Santa Catarina, 88040-900, Florianópolis, SC, Brazil; Programa de Pós-Graduação em Neurociências, Universidade Federal de Santa Catarina, 88040-900, Florianópolis, SC, Brazil; Departamento de Ciências Fisiológicas, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, 88040-900, Florianópolis, SC, Brazil.
| |
Collapse
|
10
|
Dietary 23-hydroxy ursolic acid protects against diet-induced weight gain and hyperglycemia by protecting monocytes and macrophages against nutrient stress-triggered reprogramming and dysfunction and preventing adipose tissue inflammation. J Nutr Biochem 2020; 86:108483. [PMID: 32860922 DOI: 10.1016/j.jnutbio.2020.108483] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 08/11/2020] [Accepted: 08/13/2020] [Indexed: 12/11/2022]
Abstract
The aim of this study was to determine whether the atheroprotective phytochemical 23-hydroxy ursolic acid protects against diet-induced obesity and hyperglycemia by preventing nutrient stress-induced monocyte reprogramming. After a two week run-in period on a defined, phytochemical-free low-fat maintenance diet, 12-week old female C57BL/6J mice were either kept on the maintenance diet for additional 13 weeks or switched to either a high-calorie diet, a high-calorie diet supplemented with either 0.05% 23-hydroxy ursolic acid or a high-calorie diet supplemented with 0.2% 23-hydroxy ursolic acid. Dietary supplementation with 23-hydroxy ursolic acid reduced weight gain and adipose tissue mass, prevented hyperglycemia, hyperleptinemia and adipose tissue inflammation, and preserved glucose tolerance. 23-Hydroxy ursolic acid also preserved blood monocyte mitogen-activated protein kinase phosphatase-1 activity, a biomarker of monocyte health, and reduced macrophage content in the adipose tissue. Targeted gene profiling by qRT-PCR using custom-designed TaqMan® Array Cards revealed that dietary 23-hydroxy ursolic acid converts macrophages into a transcriptionally hyperactive phenotype with enhanced antioxidant defenses and anti-inflammatory potential. In conclusion, our findings show that dietary 23-hydroxy ursolic acid exerts both anti-obesogenic effects through multiple mechanisms. These include improving glucose tolerance, preventing hyperleptinemia, maintaining blood monocyte function, reducing recruitment of monocyte-derived macrophages into adipose tissues during nutrient stress, and converting these macrophages into an anti-inflammatory, potentially inflammation-resolving phenotype, all contributing to reduced adipose tissue inflammation. Our data suggest that 23-hydroxy ursolic acid may serve as an oral therapeutic and dietary supplement suited for patients at risk for obesity, impaired glucose tolerance and cardiovascular disease.
Collapse
|
11
|
Bracht JR, Vieira‐Potter VJ, De Souza Santos R, Öz OK, Palmer BF, Clegg DJ. The role of estrogens in the adipose tissue milieu. Ann N Y Acad Sci 2019; 1461:127-143. [DOI: 10.1111/nyas.14281] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 10/24/2019] [Accepted: 11/04/2019] [Indexed: 12/12/2022]
Affiliation(s)
| | | | | | - Orhan K. Öz
- Department of RadiologyUniversity of Texas Southwestern Medical Center Dallas Texas
| | - Biff F. Palmer
- Department of MedicineUniversity of Texas Southwestern Medical Center Dallas Texas
| | - Deborah J. Clegg
- College of Nursing and Health ProfessionsDrexel University Philadelphia Pennsylvania
| |
Collapse
|
12
|
Pence S, Zhu Q, Binne E, Liu M, Shi H, Lo CC. Reduced Diet-induced Thermogenesis in Apolipoprotein A-IV Deficient Mice. Int J Mol Sci 2019; 20:E3176. [PMID: 31261740 PMCID: PMC6651278 DOI: 10.3390/ijms20133176] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 06/21/2019] [Accepted: 06/25/2019] [Indexed: 12/14/2022] Open
Abstract
In the presence of dietary lipids, both apolipoprotein A-IV (ApoA-IV) production and brown adipose tissue (BAT) thermogenesis are increased. The effect of dietary lipid-induced AproA-IV on BAT thermogenesis and energy expenditure remains unknown. In the present study, we hypothesized that ApoA-IV knockout (ApoA-IV-KO) mice exhibited decreased BAT thermogenesis to affect energy homeostasis. To test this hypothesis, BAT thermogenesis in wildtype (WT) and ApoA-IV-KO mice fed either a standard low-fat chow diet or a high-fat diet (HFD) was investigated. When fed a chow diet, energy expenditure and food intake were comparable between WT and ApoA-IV-KO mice. After 1 week of HFD consumption, ApoA-IV-KO mice had comparable energy intake but produced lower energy expenditure relative to their WT controls in the dark phase. After an acute feeding of dietary lipids or 1-week HFD feeding, ApoA-IV-KO mice produced lower levels of uncoupling protein 1 (UCP1) and exhibited reduced expression of thermogenic genes in the BAT compared with WT controls. In response to cold exposure, however, ApoA-IV-KO mice had comparable energy expenditure and BAT temperature relative to WT mice. Thus, ApoA-IV-KO mice exhibited reduced diet-induced BAT thermogenesis and energy expenditure.
Collapse
Affiliation(s)
- Sydney Pence
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Diabetes Institute and Honor Tutorial College, Ohio University, Athens, OH 45701, USA
| | - Qi Zhu
- Department of Biology, Miami University, Oxford, OH 45056, USA
| | - Erin Binne
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Diabetes Institute and Honor Tutorial College, Ohio University, Athens, OH 45701, USA
| | - Min Liu
- Department of Pathology and Laboratory Medicine, Metabolic Diseases Institute, University of Cincinnati, Cincinnati, OH 45215, USA
| | - Haifei Shi
- Department of Biology, Miami University, Oxford, OH 45056, USA
| | - Chunmin C Lo
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Diabetes Institute and Honor Tutorial College, Ohio University, Athens, OH 45701, USA.
| |
Collapse
|
13
|
Zhu Q, Glazier BJ, Hinkel BC, Cao J, Liu L, Liang C, Shi H. Neuroendocrine Regulation of Energy Metabolism Involving Different Types of Adipose Tissues. Int J Mol Sci 2019; 20:E2707. [PMID: 31159462 PMCID: PMC6600468 DOI: 10.3390/ijms20112707] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 05/24/2019] [Accepted: 05/29/2019] [Indexed: 12/17/2022] Open
Abstract
Despite tremendous research efforts to identify regulatory factors that control energy metabolism, the prevalence of obesity has been continuously rising, with nearly 40% of US adults being obese. Interactions between secretory factors from adipose tissues and the nervous system innervating adipose tissues play key roles in maintaining energy metabolism and promoting survival in response to metabolic challenges. It is currently accepted that there are three types of adipose tissues, white (WAT), brown (BAT), and beige (BeAT), all of which play essential roles in maintaining energy homeostasis. WAT mainly stores energy under positive energy balance, while it releases fuels under negative energy balance. Thermogenic BAT and BeAT dissipate energy as heat under cold exposure to maintain body temperature. Adipose tissues require neural and endocrine communication with the brain. A number of WAT adipokines and BAT batokines interact with the neural circuits extending from the brain to cooperatively regulate whole-body lipid metabolism and energy homeostasis. We review neuroanatomical, histological, genetic, and pharmacological studies in neuroendocrine regulation of adipose function, including lipid storage and mobilization of WAT, non-shivering thermogenesis of BAT, and browning of BeAT. Recent whole-tissue imaging and transcriptome analysis of differential gene expression in WAT and BAT yield promising findings to better understand the interaction between secretory factors and neural circuits, which represents a novel opportunity to tackle obesity.
Collapse
Affiliation(s)
- Qi Zhu
- Program of Physiology and Neuroscience, Department of Biology, Miami University, Oxford, OH 45056, USA.
| | - Bradley J Glazier
- Program of Physiology and Neuroscience, Department of Biology, Miami University, Oxford, OH 45056, USA.
| | - Benjamin C Hinkel
- Program of Physiology and Neuroscience, Department of Biology, Miami University, Oxford, OH 45056, USA.
| | - Jingyi Cao
- Program of Physiology and Neuroscience, Department of Biology, Miami University, Oxford, OH 45056, USA.
| | - Lin Liu
- Program of Bioinformatics, Department of Biology, Miami University, Oxford, OH 45056, USA.
| | - Chun Liang
- Program of Bioinformatics, Department of Biology, Miami University, Oxford, OH 45056, USA.
| | - Haifei Shi
- Program of Physiology and Neuroscience, Department of Biology, Miami University, Oxford, OH 45056, USA.
| |
Collapse
|
14
|
Kim MJ, Namkung J, Chang JS, Kim SJ, Park KS, Kong ID. Leptin regulates the expression of angiopoietin-like 6. Biochem Biophys Res Commun 2018; 502:397-402. [PMID: 29852166 DOI: 10.1016/j.bbrc.2018.05.180] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2018] [Accepted: 05/26/2018] [Indexed: 09/30/2022]
Abstract
Angiopoietin-like 6 (ANGPTL6) is a hepatokine that antagonizes obesity and insulin resistance by increasing energy expenditure. Despite its beneficial effects on metabolism, human studies have shown a paradoxical increase in ANGPTL6 level in the serum of patients with metabolic diseases, which has been interpreted as a compensatory upregulation. However, the regulatory mechanism of ANGPTL6 remains unclear. Since upregulation of ANGPTL6 is induced on metabolic stress, we investigated the hepatic expression of ANGPTL6 by leptin, a representative adipokine of obesity. Mice on a high-fat diet showed increased serum leptin levels and hepatic Angptl6 expression, which were attenuated by exercise training. A single leptin injection also induced hepatic ANGPTL6 expression and increased serum ANGPTL6 levels. In an in vitro model using primary hepatocytes, leptin treatment significantly upregulated ANGPTL6 expression at the mRNA and protein levels, as well as the amount of secreted ANGPTL6 protein in conditioned media. Similarly, exercise training on human participants also showed diminished serum levels of leptin and ANGPTL6. Altogether, these results strongly indicated that hepatic ANGPTL6 expression was determined by leptin.
Collapse
Affiliation(s)
- Min-Jeong Kim
- Institute of Medical Research, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, South Korea; Department of Physiology, Yonsei University Wonju College of Medicine, Wonju, South Korea
| | - Jun Namkung
- Department of Biochemistry, Yonsei University Wonju College of Medicine, Wonju, South Korea; Mitohormesis Research Center, Yonsei University Wonju College of Medicine, Wonju, South Korea
| | - Jae Seung Chang
- Mitohormesis Research Center, Yonsei University Wonju College of Medicine, Wonju, South Korea; Institute of Lifestyle Medicine, Yonsei University Wonju College of Medicine, Wonju, South Korea
| | - Soo-Jin Kim
- Department of Physiology, Yonsei University Wonju College of Medicine, Wonju, South Korea; Mitohormesis Research Center, Yonsei University Wonju College of Medicine, Wonju, South Korea
| | - Kyu-Sang Park
- Department of Physiology, Yonsei University Wonju College of Medicine, Wonju, South Korea; Mitohormesis Research Center, Yonsei University Wonju College of Medicine, Wonju, South Korea; Institute of Lifestyle Medicine, Yonsei University Wonju College of Medicine, Wonju, South Korea
| | - In Deok Kong
- Department of Physiology, Yonsei University Wonju College of Medicine, Wonju, South Korea; Institute of Lifestyle Medicine, Yonsei University Wonju College of Medicine, Wonju, South Korea.
| |
Collapse
|
15
|
Cao J, Zhu Q, Liu L, Glazier BJ, Hinkel BC, Liang C, Shi H. Global Transcriptome Analysis of Brown Adipose Tissue of Diet-Induced Obese Mice. Int J Mol Sci 2018; 19:ijms19041095. [PMID: 29642370 PMCID: PMC5979511 DOI: 10.3390/ijms19041095] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 03/17/2018] [Accepted: 03/24/2018] [Indexed: 12/16/2022] Open
Abstract
Consumption of a high-fat diet (HFD) promotes the development of obesity, a disease resulting from an imbalance between energy intake and energy expenditure. Brown adipose tissue (BAT) has thermogenic capacity that burns calories to produce heat, and it is a potential target for the treatment and prevention of obesity. There is limited information regarding the impact of HFD on the BAT transcriptome. We hypothesized that HFD-induced obesity would lead to transcriptional regulation of BAT genes. RNA sequencing was used to generate global transcriptome profiles from BAT of lean mice fed with a low-fat diet (LFD) and obese mice fed with a HFD. Gene Ontology (GO) analysis identified increased expression of genes involved in biological processes (BP) related to immune responses, which enhanced molecular function (MF) in chemokine activity; decreased expression of genes involved in BP related to ion transport and muscle structure development, which reduced MF in channel and transporter activity and structural binding. Kyoto Encyclopedia of Genes and Genomes (KEGG) functional pathway analysis indicated that pathways associated with innate immunity were enhanced by HFD, while pathways associated with muscle contraction and calcium signaling were suppressed by HFD. Collectively, these results suggest that diet-induced obesity changes transcriptomic signatures of BAT, leading to dysfunction involving inflammation, calcium signaling, ion transport, and cell structural development.
Collapse
Affiliation(s)
- Jingyi Cao
- Program of Physiology and Neuroscience, Department of Biology, Miami University, Oxford, OH 45056, USA.
| | - Qi Zhu
- Program of Physiology and Neuroscience, Department of Biology, Miami University, Oxford, OH 45056, USA.
| | - Lin Liu
- Program of Bioinformatics, Department of Biology, Miami University, Oxford, OH 45056, USA.
| | - Bradley J Glazier
- Program of Physiology and Neuroscience, Department of Biology, Miami University, Oxford, OH 45056, USA.
| | - Benjamin C Hinkel
- Program of Physiology and Neuroscience, Department of Biology, Miami University, Oxford, OH 45056, USA.
| | - Chun Liang
- Program of Bioinformatics, Department of Biology, Miami University, Oxford, OH 45056, USA.
| | - Haifei Shi
- Program of Physiology and Neuroscience, Department of Biology, Miami University, Oxford, OH 45056, USA.
| |
Collapse
|
16
|
Yamazaki T, Okawa S, Takahashi M. The effects on weight loss and gene expression in adipose and hepatic tissues of very-low carbohydrate and low-fat isoenergetic diets in diet-induced obese mice. Nutr Metab (Lond) 2016; 13:78. [PMID: 27826354 PMCID: PMC5100287 DOI: 10.1186/s12986-016-0139-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 10/24/2016] [Indexed: 12/23/2022] Open
Abstract
Background Obesity is caused by excessive fat or carbohydrate intake. The improvement of obesity is an important issue, especially in Western societies. Both low-carbohydrate diet (LCD) and low-fat diet (LFD) are used to achieve weight loss in humans. To clarify the mechanisms underlying LCD-induced weight loss, especially in early stage, we compared the gene expression in liver, white adipose tissue (WAT) and brown adipose tissue (BAT) of a very-low carbohydrate diet (VLCD)- and LFD-fed diet-induced obese (DIO) mice. Methods DIO male ddY mice were divided into high-fat diet (HFD), and isoenergetic VLCD and LFD groups. Pair-feeding was performed in the VLCD and LFD groups. Three weeks later, the body, liver, WAT and BAT were weighed and the serum and hepatic lipids, the mRNA expression levels in each tissue, and energy metabolism were analyzed. Results The caloric intake of the VLCD-fed mice was initially reduced but was subsequently restored. The total energy intake was similar in the VLCD- and LFD-fed mice. There was a similar decrease in the BW of the VLCD- and LFD-fed mice. The VLCD-fed mice had elevated levels of serum fibroblast growth factor 21 (FGF21) and ketone bodies, which are known to increase energy expenditure. The browning of WAT was observed to a greater extent in the VLCD-fed mice. Moreover, in the VLCD-fed mice, BAT activation was observed, the weight of the BAT was decreased, and the expression of G-protein-coupled receptor 120, type 2 iodothyronine deiodinase, and FGF21 in BAT was extremely increased. Although the energy expenditure of the VLCD- and LFD-fed mice did not differ, that of the VLCD-fed mice was sometimes higher during the dark cycle. Hepatic TG accumulation was reduced in LFD-fed mice due to their decreased fatty acid uptake but not in the VLCD-fed mice. The pro-inflammatory macrophage ratio was increased in the WAT of VLCD-fed mice. Conclusions After 3 weeks, the isoenergetic VLCD- and LFD-fed DIO mice showed similar weight loss. The VLCD-fed mice increased serum concentration of FGF21 and ketone bodies, and marker mRNA levels of browning in WAT, activation in BAT and hepatic lipogenesis.
Collapse
Affiliation(s)
- Tomomi Yamazaki
- Department of Nutritional Science, National Institute of Health and Nutrition, National Institutes of Biomedical Innovation, Health and Nutrition, 1-23-1 Toyama, Shinjuku-ku, Tokyo, 162-8636 Japan
| | - Sumire Okawa
- Department of Nutritional Science, National Institute of Health and Nutrition, National Institutes of Biomedical Innovation, Health and Nutrition, 1-23-1 Toyama, Shinjuku-ku, Tokyo, 162-8636 Japan
| | - Mayumi Takahashi
- Department of Life Science, Osaka Women's Junior College, 3-8-1 Kasugaoka, Fujiidera City, Osaka 583-8558 Japan
| |
Collapse
|
17
|
Bardoxolone Methyl Prevents Mesenteric Fat Deposition and Inflammation in High-Fat Diet Mice. ScientificWorldJournal 2015; 2015:549352. [PMID: 26618193 PMCID: PMC4651788 DOI: 10.1155/2015/549352] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 10/18/2015] [Indexed: 12/15/2022] Open
Abstract
Mesenteric fat belongs to visceral fat. An increased deposition of mesenteric fat contributes to obesity associated complications such as type 2 diabetes and cardiovascular diseases. We have investigated the therapeutic effects of bardoxolone methyl (BARD) on mesenteric adipose tissue of mice fed a high-fat diet (HFD). Male C57BL/6J mice were administered oral BARD during HFD feeding (HFD/BARD), only fed a high-fat diet (HFD), or fed low-fat diet (LFD) for 21 weeks. Histology and immunohistochemistry were used to analyse mesenteric morphology and macrophages, while Western blot was used to assess the expression of inflammatory, oxidative stress, and energy expenditure proteins. Supplementation of drinking water with BARD prevented mesenteric fat deposition, as determined by a reduction in large adipocytes. BARD prevented inflammation as there were fewer inflammatory macrophages and reduced proinflammatory cytokines (interleukin-1 beta and tumour necrosis factor alpha). BARD reduced the activation of extracellular signal-regulated kinase (ERK) and Akt, suggesting an antioxidative stress effect. BARD upregulates energy expenditure proteins, judged by the increased activity of tyrosine hydroxylase (TH) and AMP-activated protein kinase (AMPK) and increased peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), and uncoupling protein 2 (UCP2) proteins. Overall, BARD induces preventive effect in HFD mice through regulation of mesenteric adipose tissue.
Collapse
|
18
|
Abstract
Tackling increasing rates of obesity is likely to be a defining feature of health care over the next several decades. Adult obesity is a persistent and treatment-resistant problem. Consequently, an emerging theme in the literature is to commence prevention efforts earlier in the developmental time course. This view is based primarily on epidemiological data demonstrating a link between traits manifesting early during development and increased obesity risk in adulthood. Physical activity is a perennial factor in discussions of obesity prevention. However, the optimal timing and type of physical activity interventions to commence remains unclear. Critical developmental windows of plasticity may afford time-limited opportunities to shape body composition across the life course; however, physical activity has not been explicitly considered in these discussions. Although animal models suggest that physical activity commenced earlier in development has differential effects on obesity onset compared to physical activity commenced in adulthood, human research is lacking. In this conceptual review, we consider physical activity during critical developmental periods as a way to mitigate obesity risk later in life.
Collapse
Affiliation(s)
- S J Street
- Mater Health Services South Brisbane, Brisbane, Queensland, Australia.,Mater Research, Centre for Nutrition and Exercise, South Brisbane, Queensland, Australia
| | - J C K Wells
- Childhood Nutrition Research Centre, University College London Institute of Child Health, London, England
| | - A P Hills
- Mater Health Services South Brisbane, Brisbane, Queensland, Australia.,Mater Research, Centre for Nutrition and Exercise, South Brisbane, Queensland, Australia.,Griffith Health Institute, Griffith University, Gold Coast, Queensland, Australia
| |
Collapse
|
19
|
Dinh CHL, Szabo A, Camer D, Yu Y, Wang H, Huang XF. Bardoxolone methyl prevents fat deposition and inflammation in the visceral fat of mice fed a high-fat diet. Chem Biol Interact 2015; 229:1-8. [PMID: 25637688 DOI: 10.1016/j.cbi.2015.01.025] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Revised: 01/07/2015] [Accepted: 01/20/2015] [Indexed: 12/14/2022]
Abstract
Key features of diet-induced obesity are visceral fat deposition, macrophage infiltration and inflammation that can lead to metabolic disorders. This study examined the effects of bardoxolone methyl (BARD) in preventing obesity and inflammation in the visceral fat of mice fed high-fat diet. Male C57BL/6J mice were fed a high-fat diet (HFD), a low-fat diet (LFD, i.e., lab chow diet) or a high-fat diet supplemented with BARD (HFD/BARD) for 21weeks. BARD at a dosage of 10mg/kg body weight was administered orally in drinking water. Histology, immunohistochemistry and Western blot were used for the analysis of epididymal adipose tissue. Morphological results demonstrated that HFD fed mice treated with BARD had smaller adipocytes and fewer macrophages present in epididymal adipose tissue than the HFD group. Furthermore, BARD administration reduced the inflammatory profile in this tissue by increasing the expression of nuclear factor of kappa-light-polypeptide gene enhancer in B-cells inhibitor, alpha (IκB-α) protein and decreasing the protein expression of tumour necrosis factor alpha (TNF-α). BARD also prevented oxidative stress reflected by a reduction in stress activated proteins, including signal transducer and activator of transcription 3 (STAT3), protein kinase B (Akt), extracellular-signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK). BARD administration activated the sympathetic nervous system in epididymal adipose tissue assessed by the increased synthesis of tyrosine hydroxylase (TH) and uncoupling protein 2 (UCP2). The expression of inflammatory and sympathetic nervous system proteins in BARD mice fed a HFD was equivalent to that of the LFD control mice, indicating the anti-inflammatory and anti-obesity properties of this drug. In conclusion, the oral administration of BARD in HFD mice prevented fat deposition, inflammation and oxidative stress, and improved sympathetic activity in visceral fat. This study suggests a potential therapeutic role of BARD in preventing the development of obesity.
Collapse
Affiliation(s)
- Chi H L Dinh
- Centre for Translational Neuroscience, School of Medicine, University of Wollongong and Illawarra Health and Medical Research Institute, NSW 2522, Australia
| | - Alexander Szabo
- Centre for Translational Neuroscience, School of Medicine, University of Wollongong and Illawarra Health and Medical Research Institute, NSW 2522, Australia; ANSTO LifeSciences, Australian Nuclear Science and Technology Organisation, NSW 2234, Australia
| | - Danielle Camer
- Centre for Translational Neuroscience, School of Medicine, University of Wollongong and Illawarra Health and Medical Research Institute, NSW 2522, Australia
| | - Yinghua Yu
- Centre for Translational Neuroscience, School of Medicine, University of Wollongong and Illawarra Health and Medical Research Institute, NSW 2522, Australia
| | - Hongqin Wang
- Centre for Translational Neuroscience, School of Medicine, University of Wollongong and Illawarra Health and Medical Research Institute, NSW 2522, Australia
| | - Xu-Feng Huang
- Centre for Translational Neuroscience, School of Medicine, University of Wollongong and Illawarra Health and Medical Research Institute, NSW 2522, Australia.
| |
Collapse
|
20
|
Mice fed fish oil diet and upregulation of brown adipose tissue thermogenic markers. Eur J Nutr 2015; 55:159-69. [PMID: 25612928 DOI: 10.1007/s00394-015-0834-0] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Accepted: 01/08/2015] [Indexed: 12/31/2022]
Abstract
PURPOSE Fish oil (FO) elicits diverse beneficial effects. Reduction in or prevention of body mass (BM) gain in animal models may be associated with modulation of brown adipose tissue (BAT). We aimed to evaluate the effects of different high-fat diets with FO on BAT metabolism and thermogenic markers. METHODS C57BL/6 male mice (3-month-old) were fed different diets during 8 weeks: standard-chow diet (SC 10% fat), high-fat lard diet (HF-L 50% fat), high-fat lard plus FO diet (HF-L+FO 50% fat), and high-fat FO diet (HF-FO 50% fat). We evaluated BM and performed an oral glucose tolerance test. At euthanasia, plasma was collected for leptin, and triacylglycerol measurement and interscapular BAT was dissected and stored for molecular analyses. RESULTS HF-L group showed elevated BM; glucose intolerance associated with diminished TC10 and GLUT4 expressions; hypertriglyceridemia associated with increased CD36 and diminished CPT1 expression; elevated expression of pro-inflammatory cytokines; and reduced PPAR expression. Furthermore, these animals showed hyperleptinemia with increased expression of thermogenic markers (beta3-AR, PGC1alpha, and UCP1). Conversely, HF-L+FO and HF-FO groups showed reduced BM gain with regularization of glucose tolerance and triglyceridemia, GLUT4, TC10, CD36, CPT1, and cytokines expressions. Both groups exhibited elevated PPAR and thermogenic markers expression in a dose-dependent way. CONCLUSIONS FO improves metabolic profile and upregulates thermogenic markers, suggesting an elevated thermogenesis that leads to reduced BM gain.
Collapse
|
21
|
Berkseth KE, Guyenet SJ, Melhorn SJ, Lee D, Thaler JP, Schur EA, Schwartz MW. Hypothalamic gliosis associated with high-fat diet feeding is reversible in mice: a combined immunohistochemical and magnetic resonance imaging study. Endocrinology 2014; 155:2858-67. [PMID: 24914942 PMCID: PMC4098007 DOI: 10.1210/en.2014-1121] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Gliosis, the activation of astrocyte and microglial cell populations, is a hallmark of central nervous system injury and is detectable using either immunohistochemistry or in vivo magnetic resonance imaging (MRI). Obesity in rodents and humans is associated with gliosis of the arcuate nucleus, a key hypothalamic region for the regulation of energy homeostasis and adiposity, but whether this response is permanent or reversible is unknown. Here we combine terminal immunohistochemistry analysis with serial, noninvasive MRI to characterize the progression and reversibility of hypothalamic gliosis in high-fat diet (HFD)-fed mice. The effects of HFD feeding for 16 weeks to increase body weight and adiposity relative to chow were nearly normalized after the return to chow feeding for an additional 4 weeks in the diet-reversal group. Mice maintained on the HFD for the full 20-week study period experienced continued weight gain associated with the expected increases of astrocyte and microglial activation in the arcuate nucleus, but these changes were not observed in the diet-reversal group. The proopiomelanocortin neuron number did not differ between groups. Although MRI demonstrated a positive correlation between body weight, adiposity, and the gliosis-associated T2 signal in the mediobasal hypothalamus, it did not detect the reversal of gliosis among the HFD-fed mice after the return to chow diet. We conclude that hypothalamic gliosis associated with 16-week HFD feeding is largely reversible in rodents, consistent with the reversal of the HFD-induced obesity phenotype, and extend published evidence regarding the utility of MRI as a tool for studying obesity-associated hypothalamic gliosis in vivo.
Collapse
Affiliation(s)
- Kathryn E Berkseth
- Diabetes and Obesity Center of Excellence (K.E.B., S.J.G., J.P.T., M.W.S.) and Departments of Medicine (E.A.S., S.J.M.) and Radiology (D.L.), University of Washington, Seattle, Washington 98109
| | | | | | | | | | | | | |
Collapse
|
22
|
Bake T, Murphy M, Morgan DGA, Mercer JG. Large, binge-type meals of high fat diet change feeding behaviour and entrain food anticipatory activity in mice. Appetite 2014; 77:60-71. [PMID: 24631639 PMCID: PMC4152876 DOI: 10.1016/j.appet.2014.02.020] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 02/26/2014] [Accepted: 02/28/2014] [Indexed: 11/06/2022]
Abstract
Male C57BL/6 mice fed ad libitum on control diet but allowed access to a palatable high fat diet (HFD) for 2 h a day during the mid-dark phase rapidly adapt their feeding behaviour and can consume nearly 80% of their daily caloric intake during this 2 h-scheduled feed. We assessed food intake microstructure and meal pattern, and locomotor activity and rearing as markers of food anticipatory activity (FAA). Schedule fed mice reduced their caloric intake from control diet during the first hours of the dark phase but not during the 3-h period immediately preceding the scheduled feed. Large meal/binge-like eating behaviour during the 2-h scheduled feed was characterised by increases in both meal number and meal size. Rearing was increased during the 2-h period running up to scheduled feeding while locomotor activity started to increase 1 h before, indicating that schedule-fed mice display FAA. Meal number and physical activity changes were sustained when HFD was withheld during the anticipated scheduled feeding period, and mice immediately binged when HFD was represented after a week of this "withdrawal" period. These findings provide important context to our previous studies suggesting that energy balance systems in the hypothalamus are not responsible for driving these large, binge-type meals. Evidence of FAA in HFD dark phase schedule-fed mice implicates anticipatory processes in binge eating that do not involve immediately preceding hypophagia or regulatory homeostatic signalling.
Collapse
Affiliation(s)
- T Bake
- University of Aberdeen, Rowett Institute of Nutrition and Health, Ingestive Behaviour Group, Bucksburn, Aberdeen, UK
| | - M Murphy
- University of Aberdeen, Rowett Institute of Nutrition and Health, Ingestive Behaviour Group, Bucksburn, Aberdeen, UK
| | - D G A Morgan
- AstraZeneca, Mereside, Alderley Park, Macclesfield, UK
| | - J G Mercer
- University of Aberdeen, Rowett Institute of Nutrition and Health, Ingestive Behaviour Group, Bucksburn, Aberdeen, UK.
| |
Collapse
|
23
|
Vauthier V, Swartz TD, Chen P, Roujeau C, Pagnon M, Mallet J, Sarkis C, Jockers R, Dam J. Endospanin 1 silencing in the hypothalamic arcuate nucleus contributes to sustained weight loss of high fat diet obese mice. Gene Ther 2014; 21:638-44. [PMID: 24784449 DOI: 10.1038/gt.2014.36] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Revised: 02/19/2014] [Accepted: 03/21/2014] [Indexed: 12/21/2022]
Abstract
Leptin targets specific receptors (OB-R) expressed in the hypothalamus to regulate energy balance. Leptin decreases food intake in normal weight individuals, but this effect is blunted in obese subjects who are characterized by a state of leptin resistance. The prevention of leptin resistance is one of the major goals of obesity research. Recently, we identified endospanin 1 as a negative regulator of OB-R, which by interacting with OB-R retains the receptor inside the cell. We show here that in obese mice endospanin 1 is upregulated in the hypothalamic arcuate nucleus (ARC), the major brain structure involved in body weight regulation, suggesting that endospanin 1 is implicated in obesity development and/or the installation of leptin resistance. In contrast, silencing of endospanin 1 with lentiviral vectors in the ARC of obese mice fully restores leptin responsiveness when combined with a switch to ad libitum fed chow diet. The recovery of central leptin sensitivity is accompanied by sustained body weight loss and amelioration of blood lipid parameters and steatosis. Collectively, our results define endospanin 1 as a novel therapeutic target against obesity.
Collapse
Affiliation(s)
- V Vauthier
- 1] Inserm, U1016, Institut Cochin, Paris, France [2] CNRS UMR 8104, Paris, France [3] University Paris Descartes, Sorbonne Paris Cite, Paris, France
| | - T D Swartz
- 1] Inserm, U1016, Institut Cochin, Paris, France [2] CNRS UMR 8104, Paris, France [3] University Paris Descartes, Sorbonne Paris Cite, Paris, France
| | - P Chen
- 1] Inserm, U1016, Institut Cochin, Paris, France [2] CNRS UMR 8104, Paris, France [3] University Paris Descartes, Sorbonne Paris Cite, Paris, France
| | - C Roujeau
- 1] Inserm, U1016, Institut Cochin, Paris, France [2] CNRS UMR 8104, Paris, France [3] University Paris Descartes, Sorbonne Paris Cite, Paris, France
| | - M Pagnon
- 1] Inserm, U1016, Institut Cochin, Paris, France [2] CNRS UMR 8104, Paris, France [3] University Paris Descartes, Sorbonne Paris Cite, Paris, France
| | - J Mallet
- UMR 7091, University Paris Pierre et Marie Curie (UPMC), CNRS, NewVectys, Paris, France
| | - C Sarkis
- UMR 7091, University Paris Pierre et Marie Curie (UPMC), CNRS, NewVectys, Paris, France
| | - R Jockers
- 1] Inserm, U1016, Institut Cochin, Paris, France [2] CNRS UMR 8104, Paris, France [3] University Paris Descartes, Sorbonne Paris Cite, Paris, France
| | - J Dam
- 1] Inserm, U1016, Institut Cochin, Paris, France [2] CNRS UMR 8104, Paris, France [3] University Paris Descartes, Sorbonne Paris Cite, Paris, France
| |
Collapse
|
24
|
Ochner CN, Barrios DM, Lee CD, Pi-Sunyer FX. Biological mechanisms that promote weight regain following weight loss in obese humans. Physiol Behav 2013; 120:106-13. [PMID: 23911805 DOI: 10.1016/j.physbeh.2013.07.009] [Citation(s) in RCA: 119] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2012] [Revised: 04/05/2013] [Accepted: 07/23/2013] [Indexed: 01/25/2023]
Abstract
Weight loss dieting remains the treatment of choice for the vast majority of obese individuals, despite the limited long-term success of behavioral weight loss interventions. The reasons for the near universal unsustainability of behavioral weight loss in [formerly] obese individuals have not been fully elucidated, relegating researchers to making educated guesses about how to improve obesity treatment, as opposed to developing interventions targeting the causes of weight regain. This article discusses research on several factors that may contribute to weight regain following weight loss achieved through behavioral interventions, including adipose cellularity, endocrine function, energy metabolism, neural responsivity, and addiction-like neural mechanisms. All of these mechanisms are engaged prior to weight loss, suggesting that these so called "anti-starvation" mechanisms are activated via reductions in energy intake, rather than depletion of energy stores. Evidence suggests that these mechanisms are not necessarily part of a homeostatic feedback system designed to regulate body weight, or even anti-starvation mechanisms per se. Although they may have evolved to prevent starvation, they appear to be more accurately described as anti-weight loss mechanisms, engaged with caloric restriction irrespective of the adequacy of energy stores. It is hypothesized that these factors may combine to create a biological disposition that fosters the maintenance of an elevated body weight and works to restore the highest sustained body weight, thus precluding the long-term success of behavioral weight loss. It may be necessary to develop interventions that attenuate these biological mechanisms in order to achieve long-term weight reduction in obese individuals.
Collapse
Affiliation(s)
- Christopher N Ochner
- New York Obesity Nutrition Research Center, St. Luke's Roosevelt Hospital, Columbia University College of Physicians and Surgeons, New York, NY, USA; Mount Sinai Adolescent Health Center, Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| | | | | | | |
Collapse
|
25
|
Leptin resistance is a secondary consequence of the obesity in ciliopathy mutant mice. Proc Natl Acad Sci U S A 2013; 110:7796-801. [PMID: 23599282 DOI: 10.1073/pnas.1210192110] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Although primary cilia are well established as important sensory and signaling structures, their function in most tissues remains unknown. Obesity is a feature associated with some syndromes of cilia dysfunction, such as Bardet-Biedl syndrome (BBS) and Alström syndrome, as well as in several cilia mutant mouse models. Recent data indicate that obesity in BBS mutant mice is due to defects in leptin receptor trafficking and leptin resistance. Furthermore, induction of cilia loss in leptin-responsive proopiomelanocortin neurons results in obesity, implicating cilia on hypothalamic neurons in regulating feeding behavior. Here, we directly test the importance of the cilium as a mediator of the leptin response. In contrast to the current dogma, a longitudinal study of conditional Ift88 cilia mutant mice under different states of adiposity indicates that leptin resistance is present only when mutants are obese. Our studies show that caloric restriction leads to an altered anticipatory feeding behavior that temporarily abrogates the anorectic actions of leptin despite normalized circulating leptin levels. Interestingly, preobese Bbs4 mutant mice responded to the anorectic effects of leptin and did not display other phenotypes associated with defective leptin signaling. Furthermore, thermoregulation and activity measurements in cilia mutant mice are inconsistent with phenotypes previously observed in leptin deficient ob/ob mice. Collectively, these data indicate that cilia are not directly involved in leptin responses and that a defect in the leptin signaling axis is not the initiating event leading to hyperphagia and obesity associated with cilia dysfunction.
Collapse
|
26
|
YANG JUNPENG, REN JIANMIN, SONG JUN, LIU FUQIANG, WU CHUANLONG, WANG XUPING, GONG LEI, LI WENJUAN, XIAO FANG, YAN FEI, HOU XINGUO, CHEN LI. Glucagon-like peptide 1 regulates adipogenesis in 3T3-L1 preadipocytes. Int J Mol Med 2013; 31:1429-35. [DOI: 10.3892/ijmm.2013.1350] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Accepted: 03/18/2013] [Indexed: 11/06/2022] Open
|
27
|
Yang Y, Smith DL, Hu HH, Zhai G, Nagy TR. Chemical-shift water-fat MRI of white adipose depots: inability to resolve cell size differences. INTERNATIONAL JOURNAL OF BODY COMPOSITION RESEARCH 2013; 11:9-16. [PMID: 23667321 PMCID: PMC3649013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
PURPOSE Adipocyte cell size varies among individuals and importantly, is inversely correlated with insulin sensitivity, and modifiable by weight loss or pharmaceutical agents. However, there are no non-invasive, in vivo methods for adipocyte cell size determination. Here we apply Chemical-Shift Water-Fat MRI to in vivo measures of subcutaneous (inguinal) and visceral (gonadal) white adipose tissue (WAT) to determine whether the fat-signal fraction (FF) is a sensitive indicator of adipocyte cell size. MATERIALS AND METHODS C57BL/6J male mice (8 weeks old) were singly housed and fed a low-fat diet, high-fat diet or very high-fat diet (n = 16 or 15/group) for 8 weeks. Food intake, body weight and composition were measured; CS-MRI was performed on a 9.4 Tesla Bruker magnet with respiratory gating and anesthesia. Histology was acquired for gonadal WAT; both gonadal and inguinal WAT were fixed with osmium tetroxide and then measured through Image J for cell size. RESULTS Mice fed with higher fat content diets gained significantly more body weight, fat and lean mass while maintaining higher energy intakes over the 8 weeks. There was no significant difference in fat fraction for either gonadal (P = 0.1295) or inguinal (P = 0.4704) WAT among the three groups, despite significantly larger adipocytes (P <0.0001) in mice on high fat diets. CONCLUSION Although diet-induced obesity significantly increased the amount of fat mass, as well as mean and overall white adipocyte cell size, the CS-MRI measured fat fraction between groups were not significantly different. These results do not support the utility of CS-MRI measured FF for in vivo determination of adipocyte cell size.
Collapse
Affiliation(s)
- Yongbin Yang
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Daniel L. Smith
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL, USA
- Nutrition Obesity Research Center, University of Alabama at Birmingham, Birmingham, AL, USA
- Diabetes Research Training Center, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Houchun H. Hu
- Department of Radiology, Children’s Hospital Los Angeles, University of Southern California, Los Angeles, CA, USA
| | - Guihua Zhai
- Department of Radiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Tim R. Nagy
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL, USA
- Nutrition Obesity Research Center, University of Alabama at Birmingham, Birmingham, AL, USA
- Diabetes Research Training Center, University of Alabama at Birmingham, Birmingham, AL, USA
| |
Collapse
|
28
|
Kim DH, Gutierrez-Aguilar R, Kim HJ, Woods SC, Seeley RJ. Increased adipose tissue hypoxia and capacity for angiogenesis and inflammation in young diet-sensitive C57 mice compared with diet-resistant FVB mice. Int J Obes (Lond) 2012; 37:853-60. [PMID: 22964790 PMCID: PMC3525796 DOI: 10.1038/ijo.2012.141] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Objective High-fat diets result in increased body weight. However, this is not uniform and determining the factors that make some animals or individual more susceptible to this diet-induced weight gain is a critical research question. The expansion of white adipose tissue (WAT) associated with weight gain requires high rates of angiogenesis to support the expanding tissue mass. We hypothesized that diet-induced obese (DIO) mice have a greater capacity for WAT angiogenesis and remodeling than diet-resistant (DR) mice at a young age, prior to age or diet-induced obesity. Design We measured body weight and body composition by NMR. We compared the expression of genes related to lipid metabolism, angiogenesis and inflammation by RT-qPCR and PCR arrays. WAT morphology and distribution of adipocyte size were analyzed. The level of hypoxia and vascular density was assessed by immunohistochemistry in WAT of young mice. Results C57Bl/6 mice were DIO and FVB/N mice DR after 8 weeks on a low fat diet or high fat diet (HFD). However, C57Bl/6 mice had lower body weight, lower adiposity, smaller adipocytes and decreased leptin and lipogenic genes expression in AT than FVB/N mice at 9 weeks of age on a chow diet. Despite having smaller adipocytes, the level of hypoxia and the expression of pro-angiogenesis genes were higher in WAT of young C57Bl/6 mice than young FVB/N mice. In addition, expression of genes related to macrophages and their recruitment, and to proinflammatory cytokines, was significantly higher in WAT of young C57Bl/6 mice than young FVB/N mice. Conclusion These data suggest that the potential for WAT remodeling in early period of growth is higher in C57Bl/6 mice as compared to FVB/N mice and we hypothesize that it may contribute to the increased susceptibility to DIO of C57Bl/6 mice.
Collapse
Affiliation(s)
- D-H Kim
- Department of Pharmacology, Korea University College of Medicine, Seoul, Republic of Korea
| | | | | | | | | |
Collapse
|
29
|
Singh P, Somers VK, Romero-Corral A, Sert-Kuniyoshi FH, Pusalavidyasagar S, Davison DE, Jensen MD. Effects of weight gain and weight loss on regional fat distribution. Am J Clin Nutr 2012; 96:229-33. [PMID: 22760561 PMCID: PMC3396439 DOI: 10.3945/ajcn.111.033829] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Normal-weight adults gain lower-body fat via adipocyte hyperplasia and upper-body subcutaneous (UBSQ) fat via adipocyte hypertrophy. OBJECTIVES We investigated whether regional fat loss mirrors fat gain and whether the loss of lower-body fat is attributed to decreased adipocyte number or size. DESIGN We assessed UBSQ, lower-body, and visceral fat gains and losses in response to overfeeding and underfeeding in 23 normal-weight adults (15 men) by using dual-energy X-ray absorptiometry and abdominal computed tomography scans. Participants gained ∼5% of weight in 8 wk and lost ∼80% of gained fat in 8 wk. We measured abdominal subcutaneous and femoral adipocyte sizes and numbers after weight gain and loss. RESULTS Volunteers gained 3.1 ± 2.1 (mean ± SD) kg body fat with overfeeding and lost 2.4 ± 1.7 kg body fat with underfeeding. Although UBSQ and visceral fat gains were completely reversed after 8 wk of underfeeding, lower-body fat had not yet returned to baseline values. Abdominal and femoral adipocyte sizes, but not numbers, decreased with weight loss. Decreases in abdominal adipocyte size and UBSQ fat mass were correlated (ρ = 0.76, P = 0.001), as were decreases in femoral adipocyte size and lower-body fat (ρ = 0.49, P = 0.05). CONCLUSIONS UBSQ and visceral fat increase and decrease proportionately with a short-term weight gain and loss, whereas a gain of lower-body fat does not relate to the loss of lower-body fat. The loss of lower-body fat is attributed to a reduced fat cell size, but not number, which may result in long-term increases in fat cell numbers.
Collapse
Affiliation(s)
- Prachi Singh
- Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN, USA
| | | | | | | | | | | | | |
Collapse
|
30
|
Benz V, Bloch M, Wardat S, Böhm C, Maurer L, Mahmoodzadeh S, Wiedmer P, Spranger J, Foryst-Ludwig A, Kintscher U. Sexual dimorphic regulation of body weight dynamics and adipose tissue lipolysis. PLoS One 2012; 7:e37794. [PMID: 22662224 PMCID: PMC3360591 DOI: 10.1371/journal.pone.0037794] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2011] [Accepted: 04/28/2012] [Indexed: 01/01/2023] Open
Abstract
Background Successful reduction of body weight (BW) is often followed by recidivism to obesity. BW-changes including BW-loss and -regain is associated with marked alterations in energy expenditure (EE) and adipose tissue (AT) metabolism. Since these processes are sex-specifically controlled, we investigated sexual dimorphisms in metabolic processes during BW-dynamics (gain-loss-regain). Research Design Obesity was induced in C57BL/6J male (m) and female (f) mice by 15 weeks high-fat diet (HFD) feeding. Subsequently BW was reduced (-20%) by caloric restriction (CR) followed by adaptive feeding, and a regain-phase. Measurement of EE, body composition, blood/organ sampling were performed after each feeding period. Lipolysis was analyzed ex-vivo in gonadal AT. Results Male mice exhibited accelerated BW-gain compared to females (relative BW-gain m:140.5±3.2%; f:103.7±6.5%; p<0.001). In consonance, lean mass-specific EE was significantly higher in females compared to males during BW-gain. Under CR female mice reached their target-BW significantly faster than male mice (m:12.2 days; f:7.6 days; p<0.001) accompanied by a sustained sex-difference in EE. In addition, female mice predominantly downsized gonadal AT whereas the relation between gonadal and total body fat was not altered in males. Accordingly, only females exhibited an increased rate of forskolin-stimulated lipolysis in AT associated with significantly higher glycerol concentrations, lower RER-values, and increased AT expression of adipose triglyceride lipase (ATGL) and hormone sensitive lipase (HSL). Analysis of AT lipolysis in estrogen receptor alpha (ERα)–deficient mice revealed a reduced lipolytic rate in the absence of ERα exclusively in females. Finally, re-feeding caused BW-regain faster in males than in females. Conclusion The present study shows sex-specific dynamics during BW-gain-loss-regain. Female mice responded to CR with an increase in lipolytic activity, and augmented lipid-oxidation leading to more efficient weight loss. These processes likely involve ERα-dependent signaling in AT and sexual dimorphic regulation of genes involved in lipid metabolism.
Collapse
Affiliation(s)
- Verena Benz
- Center for Cardiovascular Research, Institute of Pharmacology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Mandy Bloch
- Center for Cardiovascular Research, Institute of Pharmacology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Sami Wardat
- Center for Cardiovascular Research, Institute of Pharmacology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Christian Böhm
- Center for Cardiovascular Research, Institute of Pharmacology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Lukas Maurer
- Department of Endocrinology, Diabetes, and Nutrition, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Shokoufeh Mahmoodzadeh
- Center for Cardiovascular Research, Institute of Gender in Medicine, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Petra Wiedmer
- Genetics of Metabolic and Reproductive Disorders, Max-Delbrueck-Center for Molecular Medicine, Berlin, Germany
| | - Joachim Spranger
- Department of Endocrinology, Diabetes, and Nutrition, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Anna Foryst-Ludwig
- Center for Cardiovascular Research, Institute of Pharmacology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Ulrich Kintscher
- Center for Cardiovascular Research, Institute of Pharmacology, Charité-Universitätsmedizin Berlin, Berlin, Germany
- * E-mail:
| |
Collapse
|
31
|
Guyenet SJ, Schwartz MW. Clinical review: Regulation of food intake, energy balance, and body fat mass: implications for the pathogenesis and treatment of obesity. J Clin Endocrinol Metab 2012; 97:745-55. [PMID: 22238401 PMCID: PMC3319208 DOI: 10.1210/jc.2011-2525] [Citation(s) in RCA: 185] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2011] [Accepted: 12/08/2011] [Indexed: 12/22/2022]
Abstract
CONTEXT Obesity has emerged as one of the leading medical challenges of the 21st century. The resistance of this disorder to effective, long-term treatment can be traced to the fact that body fat stores are subject to homeostatic regulation in obese individuals, just as in lean individuals. Because the growing obesity epidemic is linked to a substantial increase in daily energy intake, a key priority is to delineate how mechanisms governing food intake and body fat content are altered in an obesogenic environment. EVIDENCE ACQUISITION We considered all relevant published research and cited references that represented the highest quality evidence available. Where space permitted, primary references were cited. EVIDENCE SYNTHESIS The increase of energy intake that has fueled the U.S. obesity epidemic is linked to greater availability of highly rewarding/palatable and energy-dense food. Obesity occurs in genetically susceptible individuals and involves the biological defense of an elevated body fat mass, which may result in part from interactions between brain reward and homeostatic circuits. Inflammatory signaling, accumulation of lipid metabolites, or other mechanisms that impair hypothalamic neurons may also contribute to the development of obesity and offer a plausible mechanism to explain the biological defense of elevated body fat mass. CONCLUSIONS Despite steady research progress, mechanisms underlying the resistance to fat loss once obesity is established remain incompletely understood. Breakthroughs in this area may be required for the development of effective new obesity prevention and treatment strategies.
Collapse
Affiliation(s)
- Stephan J Guyenet
- Diabetes and Obesity Center of Excellence, Department of Medicine, University of Washington School of Medicine, South Lake Union, 815 Mercer Street, N334, Box 358055, Seattle, Washington 98109, USA
| | | |
Collapse
|
32
|
De Angel RE, Conti CJ, Wheatley KE, Brenner AJ, Otto G, deGraffenried LA, Hursting SD. The enhancing effects of obesity on mammary tumor growth and Akt/mTOR pathway activation persist after weight loss and are reversed by RAD001. Mol Carcinog 2012; 52:446-58. [DOI: 10.1002/mc.21878] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Accepted: 01/03/2012] [Indexed: 11/11/2022]
|
33
|
Leptin action in the dorsomedial hypothalamus increases sympathetic tone to brown adipose tissue in spite of systemic leptin resistance. J Neurosci 2011; 31:12189-97. [PMID: 21865462 DOI: 10.1523/jneurosci.2336-11.2011] [Citation(s) in RCA: 231] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Leptin regulates body weight in mice by decreasing appetite and increasing sympathetic nerve activity (SNA), which increases energy expenditure in interscapular brown adipose tissue (iBAT). Diet-induced obese mice (DIO) are resistant to the anorectic actions of leptin. We evaluated whether leptin still stimulated sympathetic outflow in DIO mice. We measured iBAT temperature as a marker of SNA. We found that obese hyperleptinemic mice have higher iBAT temperature than mice on regular diet. Conversely, obese leptin-deficient ob/ob mice have lower iBAT temperature. Additionally, leptin increased SNA in obese (DIO and ob/ob) and control mice, despite DIO mice being resistant to anorectic action of leptin. We demonstrated that neurons in the dorsomedial hypothalamus (DMH) of DIO mice mediate the thermogenic responses to hyperleptinemia in obese mammals because blockade of leptin receptors in the DMH prevented the thermogenic effects of leptin. Peripheral Melotan II (MTII) injection increased iBAT temperature, but it was blunted by blockade of DMH melanocortin receptors (MC4Rs) by injecting agouti-related peptide (AgRP) directly into the DMH, suggesting a physiological role of the DMH on temperature regulation in animals with normal body weight. Nevertheless, obese mice without a functional melanocortin system (MC4R KO mice) have an increased sympathetic outflow to iBAT compared with their littermates, suggesting that higher leptin levels drive sympathoexcitation to iBAT by a melanocortin-independent pathway. Because the sympathetic nervous system contributes in regulating blood pressure, heart rate, and hepatic glucose production, selective leptin resistance may be a crucial mechanism linking adiposity and metabolic syndrome.
Collapse
|
34
|
Ravussin Y, Gutman R, Diano S, Shanabrough M, Borok E, Sarman B, Lehmann A, LeDuc CA, Rosenbaum M, Horvath TL, Leibel RL. Effects of chronic weight perturbation on energy homeostasis and brain structure in mice. Am J Physiol Regul Integr Comp Physiol 2011; 300:R1352-62. [PMID: 21411766 DOI: 10.1152/ajpregu.00429.2010] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Maintenance of reduced body weight in lean and obese human subjects results in the persistent decrease in energy expenditure below what can be accounted for by changes in body mass and composition. Genetic and developmental factors may determine a central nervous system (CNS)-mediated minimum threshold of somatic energy stores below which behavioral and metabolic compensations for weight loss are invoked. A critical question is whether this threshold can be altered by environmental influences and by what mechanisms such alterations might be achieved. We examined the bioenergetic, behavioral, and CNS structural responses to weight reduction of diet-induced obese (DIO) and never-obese (CON) C57BL/6J male mice. We found that weight-reduced (WR) DIO-WR and CON-WR animals showed reductions in energy expenditure, adjusted for body mass and composition, comparable (-10-15%) to those seen in human subjects. The proportion of excitatory synapses on arcuate nucleus proopiomelanocortin neurons was decreased by ∼50% in both DIO-WR and CON-WR mice. These data suggest that prolonged maintenance of an elevated body weight (fat) alters energy homeostatic systems to defend a higher level of body fat. The synaptic changes could provide a neural substrate for the disproportionate decline in energy expenditure in weight-reduced individuals. This response to chronic weight elevation may also occur in humans. The mouse model described here could help to identify the molecular/cellular mechanisms underlying both the defense mechanisms against sustained weight loss and the upward resetting of those mechanisms following sustained weight gain.
Collapse
Affiliation(s)
- Y Ravussin
- 1Department of Pediatrics, Division of Molecular Genetics, Columbia University, College of Physicians and Surgeons, New York, New York 10032, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Jornayvaz FR, Jurczak MJ, Lee HY, Birkenfeld AL, Frederick DW, Zhang D, Zhang XM, Samuel VT, Shulman GI. A high-fat, ketogenic diet causes hepatic insulin resistance in mice, despite increasing energy expenditure and preventing weight gain. Am J Physiol Endocrinol Metab 2010; 299:E808-15. [PMID: 20807839 PMCID: PMC2980360 DOI: 10.1152/ajpendo.00361.2010] [Citation(s) in RCA: 159] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Low-carbohydrate, high-fat ketogenic diets (KD) have been suggested to be more effective in promoting weight loss than conventional caloric restriction, whereas their effect on hepatic glucose and lipid metabolism and the mechanisms by which they may promote weight loss remain controversial. The aim of this study was to explore the role of KD on liver and muscle insulin sensitivity, hepatic lipid metabolism, energy expenditure, and food intake. Using hyperinsulinemic-euglycemic clamps, we studied insulin action in mice fed a KD or regular chow (RC). Body composition was assessed by ¹H magnetic resonance spectroscopy. Despite being 15% lighter (P < 0.001) than RC-fed mice because of a 17% increase in energy expenditure (P < 0.001), KD-fed mice manifested severe hepatic insulin resistance, as reflected by decreased suppression (0% vs. 100% in RC-fed mice, P < 0.01) of endogenous glucose production during the clamp. Hepatic insulin resistance could be attributed to a 350% increase in hepatic diacylglycerol content (P < 0.001), resulting in increased activation of PKCε (P < 0.05) and decreased insulin receptor substrate-2 tyrosine phosphorylation (P < 0.01). Food intake was 56% (P < 0.001) lower in KD-fed mice, despite similar caloric intake, and could partly be attributed to a more than threefold increase (P < 0.05) in plasma N-acylphosphatidylethanolamine concentrations. In conclusion, despite preventing weight gain in mice, KD induces hepatic insulin resistance secondary to increased hepatic diacylglycerol content. Given the key role of nonalcoholic fatty liver disease in the development of type 2 diabetes and the widespread use of KD for the treatment of obesity, these results may have potentially important clinical implications.
Collapse
Affiliation(s)
- François R Jornayvaz
- Depts. of Internal Medicine, Yale Univ. School of Medicine, New Haven, CT 06536, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Abstract
Epidemiological studies have shown a positive relationship between dietary fat intake and obesity. Since rats and mice show a similar relationship, they are considered an appropriate model for studying dietary obesity. The present paper describes the history of using high-fat diets to induce obesity in animals, aims to clarify the consequences of changing the amount and type of dietary fats on weight gain, body composition and adipose tissue cellularity, and explores the contribution of genetics and sex, as well as the biochemical basis and the roles of hormones such as leptin, insulin and ghrelin in animal models of dietary obesity. The major factors that contribute to dietary obesity - hyperphagia, energy density and post-ingestive effects of the dietary fat - are discussed. Other factors that affect dietary obesity including feeding rhythmicity, social factors and stress are highlighted. Finally, we comment on the reversibility of high-fat diet-induced obesity.
Collapse
|
37
|
Hur YN, Hong GH, Choi SH, Shin KH, Chun BG. High fat diet altered the mechanism of energy homeostasis induced by nicotine and withdrawal in C57BL/6 mice. Mol Cells 2010; 30:219-26. [PMID: 20803089 DOI: 10.1007/s10059-010-0110-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2010] [Revised: 05/01/2010] [Accepted: 06/04/2010] [Indexed: 12/30/2022] Open
Abstract
Nicotine treatment has known to produce an inverse relationship between body weight and food intake in rodents. Present study determined the effect of repeated treatment with nicotine and withdrawal in control and obese mice, on: (1) body weight, caloric intake and energy expenditure; (2) hypothalamic neuropeptides mRNA expression; and (3) serum leptin. 21-week-old C57BL/6 mice (n = 65) received nicotine (3.0 mg/kg/day; 2 weeks) and saline (1 ml/kg/day; 2 weeks) subcutaneously. Animals were given either a normal-fat (10% kcal from fat, NF) or a high-fat diet (45% kcal from fat, HF) from the 12th week to 25th week. While, nicotine treatment for 14 days induced an increase in hypothalamic agouti-related protein, cocaine- and amphetamine- regulated transcript, pro-opiomelanocortin mRNA expressions, nicotine also produced a reducing effect in body weight gain and leptin concentration in NF mice. High-fat diet induced obese mice showed a blunted hypothalamic and leptin response to nicotine. Remarkable weight loss in obese mice was mediated not just by decreasing caloric intake, but also by increasing total energy expenditure (EE). During nicotine withdrawal period, weight gain occurred in NF and HF groups, which was ascribed to a decrease in EE rather than changes in caloric intake. Hypothalamic AgRP might play a role for maintaining energy balance under the nicotine-induced negative energy status.
Collapse
Affiliation(s)
- Young-Na Hur
- Department of Pharmacology, Korea University College of Medicine, Seoul, 136-705, Korea
| | | | | | | | | |
Collapse
|
38
|
Gloy VL, Lutz TA, Langhans W, Geary N, Hillebrand JJ. Basal plasma levels of insulin, leptin, ghrelin, and amylin do not signal adiposity in rats recovering from forced overweight. Endocrinology 2010; 151:4280-8. [PMID: 20668029 DOI: 10.1210/en.2010-0439] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
This study examined how adiposity signals are related to adiposity during recovery from forced overweight (OW). Rats were rendered OW by chronic intragastric overfeeding (OW). Overfeeding was stopped when OW rats reached 126-129% of saline-infused normal-weight (NW) rats. Adipose tissue (AT) mass was estimated by computed tomography, and blood was drawn from chronic atrial cannulas throughout. Basal levels (i.e. after 2-3 h fasts late in the diurnal phase) of the hypothesized adiposity signals insulin, leptin, ghrelin, and amylin were assayed. OW rats gained approximately 130 g more body weight (BW) and approximately 100 g more AT mass during overfeeding. Plasma levels of insulin and leptin increased, whereas those of ghrelin decreased, linearly with AT mass; amylin did not change reliably. During recovery, OW rats' BW and AT mass decreased but were still elevated vs. NW rats after 39 d. OW rats' insulin returned to NW levels on d 1 of recovery and decreased below NW levels thereafter. Leptin was no longer elevated after d 8 of recovery. Ghrelin and amylin did not change reliably during recovery. Although AT mass decreased in OW rats during each intermeasurement interval between d 0 and d 23 of recovery, insulin and leptin did so during only the first interval (d 0-5). Insulin and leptin levels were exponentially related to AT mass during recovery. These data indicate that basal insulin, leptin, ghrelin, and amylin do not encode AT mass in rats dynamically regulating BW and adiposity during recovery from OW.
Collapse
Affiliation(s)
- Viktoria L Gloy
- Physiology and Behavior Laboratory, Institute of Food, Nutrition, and Health, ETH Zurich, Schorenstrasse 16, 8603 Schwerzenbach, Switzerland
| | | | | | | | | |
Collapse
|
39
|
PI3K signaling in the ventromedial hypothalamic nucleus is required for normal energy homeostasis. Cell Metab 2010; 12:88-95. [PMID: 20620998 PMCID: PMC2919367 DOI: 10.1016/j.cmet.2010.05.002] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2009] [Revised: 12/20/2009] [Accepted: 05/03/2010] [Indexed: 11/20/2022]
Abstract
Phosphatidyl inositol 3-kinase (PI3K) signaling in the hypothalamus has been implicated in the regulation of energy homeostasis, but the critical brain sites where this intracellular signal integrates various metabolic cues to regulate food intake and energy expenditure are unknown. Here, we show that mice with reduced PI3K activity in the ventromedial hypothalamic nucleus (VMH) are more sensitive to high-fat diet-induced obesity due to reduced energy expenditure. In addition, inhibition of PI3K in the VMH impaired the ability to alter energy expenditure in response to acute high-fat diet feeding and food deprivation. Furthermore, the acute anorexigenic effects induced by exogenous leptin were blunted in the mutant mice. Collectively, our results indicate that PI3K activity in VMH neurons plays a physiologically relevant role in the regulation of energy expenditure.
Collapse
|
40
|
Influence of dietary macronutrient composition on adiposity and cellularity of different fat depots in Wistar rats. J Physiol Biochem 2009; 65:387-95. [DOI: 10.1007/bf03185934] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2009] [Indexed: 02/05/2023]
|