1
|
Smith DL, Yang Y, Mestre LM, Henschel B, Parker E, Dickinson S, Patki A, Allison DB, Nagy TR. Impact of sustained calorie restriction and weight cycling on body composition in high-fat diet-fed male and female C57BL/6J mice. Obesity (Silver Spring) 2024; 32:959-968. [PMID: 38600047 PMCID: PMC11145641 DOI: 10.1002/oby.24015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 01/18/2024] [Accepted: 01/31/2024] [Indexed: 04/12/2024]
Abstract
OBJECTIVE The objective of this study was to investigate body composition changes with weight cycling (WC) among adult C57BL/6J mice with diet-induced obesity. METHODS A total of 555 single-housed mice were fed a high-fat diet ad libitum (AL) from 8 to 43 weeks of age. The 200 heaviest mice of each sex were randomized to the following four groups: ever obese (EO, continued AL feeding); obese weight loser (OWL, calorie-restricted); obese weight loser moderate (OWLM, body weight halfway between EO and OWL); and WC (diet restricted to OWL followed by AL refeeding cycles). Body weight and composition data were collected. Linear regression was used to calculate residuals between predicted and observed fat mass. Linear mixed models were used to compare diet groups. RESULTS Although weight loss and regain resulted in changes in body weight and composition, fat mass, body weight, and relative body fat were not significantly greater for the WC group compared with the EO group. During long-term calorie restriction, males (but not females) in the OWLM group remained relatively fatter than the EO group. CONCLUSIONS WC did not increase body weight or relative fat mass for middle-aged, high-fat diet-fed adult mice. However, long-term moderate calorie restriction resulted in lower body weight but greater "relative" fat in male mice.
Collapse
Affiliation(s)
- Daniel L. Smith
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL 35294 USA
- Nutrition Obesity Research Center, University of Alabama at Birmingham, Birmingham, AL 35294 USA
- Diabetes Research Center, University of Alabama at Birmingham, Birmingham, AL 35294 USA
- Nathan Shock Center of Excellence in the Basic Biology of Aging, University of Alabama at Birmingham, Birmingham, AL 35294 USA
| | - Yongbin Yang
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL 35294 USA
- Nutrition Obesity Research Center, University of Alabama at Birmingham, Birmingham, AL 35294 USA
| | - Luis M. Mestre
- Department of Epidemiology and Biostatistics, School of Public Health-Bloomington, Indiana University, Bloomington IN, USA
| | - Beate Henschel
- Department of Epidemiology and Biostatistics, School of Public Health-Bloomington, Indiana University, Bloomington IN, USA
| | - Erik Parker
- Department of Epidemiology and Biostatistics, School of Public Health-Bloomington, Indiana University, Bloomington IN, USA
| | - Stephanie Dickinson
- Department of Epidemiology and Biostatistics, School of Public Health-Bloomington, Indiana University, Bloomington IN, USA
| | - Amit Patki
- Department of Biostatistics, University of Alabama at Birmingham, Birmingham, AL 35294 USA
| | - David B. Allison
- Nathan Shock Center of Excellence in the Basic Biology of Aging, University of Alabama at Birmingham, Birmingham, AL 35294 USA
- Department of Epidemiology and Biostatistics, School of Public Health-Bloomington, Indiana University, Bloomington IN, USA
| | - Tim R. Nagy
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL 35294 USA
- Nutrition Obesity Research Center, University of Alabama at Birmingham, Birmingham, AL 35294 USA
- Diabetes Research Center, University of Alabama at Birmingham, Birmingham, AL 35294 USA
- Nathan Shock Center of Excellence in the Basic Biology of Aging, University of Alabama at Birmingham, Birmingham, AL 35294 USA
| |
Collapse
|
2
|
Johnson JD. On the causal relationships between hyperinsulinaemia, insulin resistance, obesity and dysglycaemia in type 2 diabetes. Diabetologia 2021; 64:2138-2146. [PMID: 34296322 DOI: 10.1007/s00125-021-05505-4] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 04/23/2021] [Indexed: 12/19/2022]
Abstract
Hundreds of millions of people are affected by hyperinsulinaemia, insulin resistance, obesity and the dysglycaemia that mark a common progression from metabolic health to type 2 diabetes. Although the relative contribution of these features and the order in which they appear may differ between individuals, the common clustering and seemingly progressive nature of type 2 diabetes aetiology has guided research and clinical practice in this area for decades. At the same time, lively debate around the causal relationships between these features has continued, as new data from human trials and highly controlled animal studies are presented. This 'For debate' article was prompted by the review in Diabetologia by Esser, Utzschneider and Kahn ( https://doi.org/10.1007/s00125-020-05245-x ), with the purpose of reviewing established and emerging data that provide insight into the relative contributions of hyperinsulinaemia and impaired glucose-stimulated insulin secretion in progressive stages between health, obesity and diabetes. It is concluded that these beta cell defects are not mutually exclusive and that they are both important, but at different stages.
Collapse
Affiliation(s)
- James D Johnson
- Diabetes Research Group, Life Sciences Institute, Department of Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, BC, Canada.
- Institute for Personalized Therapeutic Nutrition, Vancouver, BC, Canada.
| |
Collapse
|
3
|
Zhang AM, Wellberg EA, Kopp JL, Johnson JD. Hyperinsulinemia in Obesity, Inflammation, and Cancer. Diabetes Metab J 2021; 45:285-311. [PMID: 33775061 PMCID: PMC8164941 DOI: 10.4093/dmj.2020.0250] [Citation(s) in RCA: 79] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 12/23/2020] [Indexed: 12/13/2022] Open
Abstract
The relative insufficiency of insulin secretion and/or insulin action causes diabetes. However, obesity and type 2 diabetes mellitus can be associated with an absolute increase in circulating insulin, a state known as hyperinsulinemia. Studies are beginning to elucidate the cause-effect relationships between hyperinsulinemia and numerous consequences of metabolic dysfunctions. Here, we review recent evidence demonstrating that hyperinsulinemia may play a role in inflammation, aging and development of cancers. In this review, we will focus on the consequences and mechanisms of excess insulin production and action, placing recent findings that have challenged dogma in the context of the existing body of literature. Where relevant, we elaborate on the role of specific signal transduction components in the actions of insulin and consequences of chronic hyperinsulinemia. By discussing the involvement of hyperinsulinemia in various metabolic and other chronic diseases, we may identify more effective therapeutics or lifestyle interventions for preventing or treating obesity, diabetes and cancer. We also seek to identify pertinent questions that are ripe for future investigation.
Collapse
Affiliation(s)
- Anni M.Y. Zhang
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Elizabeth A. Wellberg
- Department of Pathology, University of Oklahoma Health Sciences Center, Stephenson Cancer Center, Harold Hamm Diabetes Center, Oklahoma City, OK, USA
| | - Janel L. Kopp
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - James D. Johnson
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
- Corresponding author: James D. Johnson https://orcid.org/0000-0002-7523-9433 Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, 2329 W Mall Vancouver, BC V6T 1Z4, Vancouver, BC, Canada E-mail:
| |
Collapse
|
4
|
Diwekar-Joshi M, Watve M. Driver versus navigator causation in biology: the case of insulin and fasting glucose. PeerJ 2020; 8:e10396. [PMID: 33365205 PMCID: PMC7735078 DOI: 10.7717/peerj.10396] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 10/29/2020] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND In biomedicine, inferring causal relation from experimental intervention or perturbation is believed to be a more reliable approach than inferring causation from cross-sectional correlation. However, we point out here that even in interventional inference there are logical traps. In homeostatic systems, causality in a steady state can be qualitatively different from that in a perturbed state. On a broader scale there is a need to differentiate driver causality from navigator causality. A driver is essential for reaching a destination but may not have any role in deciding the destination. A navigator on the other hand has a role in deciding the destination and the path but may not be able to drive the system to the destination. The failure to differentiate between types of causalities is likely to have resulted into many misinterpretations in physiology and biomedicine. METHODS We illustrate this by critically re-examining a specific case of the causal role of insulin in glucose homeostasis using five different approaches (1) Systematic review of tissue specific insulin receptor knock-outs, (2) Systematic review of insulin suppression and insulin enhancement experiments, (3) Differentiating steady state and post-meal state glucose levels in streptozotocin treated rats in primary experiments, (4) Mathematical and theoretical considerations and (5) Glucose-insulin relationship in human epidemiological data. RESULTS All the approaches converge on the inference that although insulin action hastens the return to a steady state after a glucose load, there is no evidence that insulin action determines the steady state level of glucose. Insulin, unlike the popular belief in medicine, appears to be a driver but not a navigator for steady state glucose level. It is quite likely therefore that the current line of clinical action in the field of type 2 diabetes has limited success largely because it is based on a misinterpretation of glucose-insulin relationship. The insulin-glucose example suggests that we may have to carefully re-examine causal inferences from perturbation experiments and set up revised norms for experimental design for causal inference.
Collapse
Affiliation(s)
- Manawa Diwekar-Joshi
- Biology, Indian Institute of Science Education and Research, Pune, Maharashtra, India
| | - Milind Watve
- Deenanath Mangeshkar Hospital and Research Centre, Pune, Maharashtra, India
| |
Collapse
|
5
|
Botezelli JD, Overby P, Lindo L, Wang S, Haïda O, Lim GE, Templeman NM, Pauli JR, Johnson JD. Adipose depot-specific upregulation of Ucp1 or mitochondrial oxidative complex proteins are early consequences of genetic insulin reduction in mice. Am J Physiol Endocrinol Metab 2020; 319:E529-E539. [PMID: 32715748 DOI: 10.1152/ajpendo.00128.2020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Hyperinsulinemia plays a causal role in adipose tissue expansion. Mice with reduced insulin have increased energy expenditure, but the mechanisms remained unclear. Here we investigated the effects of genetically reducing insulin production on uncoupling and oxidative mitochondrial proteins in liver, skeletal muscle, white adipose tissue (WAT), and brown adipose tissue (BAT). Male Ins1+/+ or Ins1+/- littermates were fed either a low-fat diet (LFD) or a high-fat diet (HFD) for 4 wk, starting at 8 wk of age. Replicating our previous observations, HFD increased fasting hyperinsulinemia, and Ins1+/- mice had significantly lower circulating insulin compared with Ins1+/+ littermates. Fasting glucose and body weight were not different between genotypes. We did not observe robust significant differences in liver or skeletal muscle. In mesenteric WAT, Ins1+/- mice had reduced Ndufb8 and Sdhb, while Ucp1 was increased in the context of HFD. HFD alone had a dramatic inhibitory effect on Pparg abundance. In inguinal WAT, Ins1+/- mice exhibited significant increases in oxidative complex proteins, independent of diet, without affecting Ucp1, Pparg, or Prdm16:Pparg association. In BAT, lowered insulin increased Sdhb protein levels that had been reduced by HFD. Ucp1 protein, Prdm16:Pparg association, and Sirt3 abundance were all increased in the absence of diet-induced hyperinsulinemia. Our data show that reducing insulin upregulates oxidative proteins in inguinal WAT without affecting Ucp1, whereas in mesenteric WAT and BAT, reducing insulin upregulates Ucp1 in the context of HFD. Preventing hyperinsulinemia has early depot-specific effects on adipose tissue metabolism and helps explain the increased energy expenditure previously reported in Ins1+/- mice.
Collapse
Affiliation(s)
- Jose Diego Botezelli
- Department of Cellular Physiological Sciences, Diabetes Research group, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
- Laboratory of Molecular Biology of Exercise (LaBMEx), Faculty of Applied Sciences, University of Campinas, Limeira, São Paulo, Brazil
| | - Peter Overby
- Department of Cellular Physiological Sciences, Diabetes Research group, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Lorenzo Lindo
- Department of Cellular Physiological Sciences, Diabetes Research group, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Su Wang
- Department of Cellular Physiological Sciences, Diabetes Research group, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Obélia Haïda
- Department of Cellular Physiological Sciences, Diabetes Research group, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Gareth E Lim
- Cardiometabolic axis, Centre de recherche du Centre hospitalier de l'Université de Montréal, Université of Montréal, Montréal, Quebec, Canada
| | | | - Jose Rodrigo Pauli
- Laboratory of Molecular Biology of Exercise (LaBMEx), Faculty of Applied Sciences, University of Campinas, Limeira, São Paulo, Brazil
| | - James D Johnson
- Department of Cellular Physiological Sciences, Diabetes Research group, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| |
Collapse
|
6
|
Intermittent Fasting Enhanced the Cognitive Function in Older Adults with Mild Cognitive Impairment by Inducing Biochemical and Metabolic changes: A 3-Year Progressive Study. Nutrients 2020; 12:nu12092644. [PMID: 32872655 PMCID: PMC7551340 DOI: 10.3390/nu12092644] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 08/27/2020] [Accepted: 08/28/2020] [Indexed: 12/15/2022] Open
Abstract
Intermittent fasting (IF) refers to various dietary regimens that cycle between a period of non-fasting and a period of total fasting. This study aimed to determine the effects of IF on cognitive function among elderly individuals who practice IF who have mild cognitive impairment (MCI). A total of 99 elderly subjects with MCI of Malay ethnicity without any terminal illness were recruited from a larger cohort study, LRGS TUA. The subjects were divided into three groups, comprising those who were regularly practicing IF (r-IF), irregularly practicing IF (i-IF), and non-fasters (n-IF). Upon 36 months of follow-up, more MCI subjects in the r-IF group reverted to successful aging with no cognitive impairment and diseases (24.3%) compared to those in i-IF (14.2%) and n-IF groups (3.7%). The r-IF group’s subjects exhibited significant increment in superoxide dismutase (SOD) activity and reduction in body weight, levels of insulin, fasting blood glucose, malondialdehyde (MDA), C-reactive protein (CRP), and DNA damage. Moreover, metabolomics analysis showed that IF may modulate cognitive function via various metabolite pathways, including the synthesis and degradation of ketone bodies, butanoate metabolism, pyruvate metabolism, and glycolysis and gluconeogenesis pathways. Overall, the MCI-afflicted older adults who practiced IF regularly had better cognitive scores and reverted to better cognitive function at 36 months follow-up.
Collapse
|
7
|
Amino acid-based compound activates atypical PKC and leptin receptor pathways to improve glycemia and anxiety like behavior in diabetic mice. Biomaterials 2020; 239:119839. [PMID: 32065973 DOI: 10.1016/j.biomaterials.2020.119839] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 01/29/2020] [Accepted: 02/01/2020] [Indexed: 12/28/2022]
Abstract
Differences in glucose uptake in peripheral and neural tissues account for the reduced efficacy of insulin in nervous tissues. Herein, we report the design of short peptides, referred as amino acid compounds (AAC) with and without a modified side chain moiety. At nanomolar concentrations, a candidate therapeutic molecule, AAC2, containing a 7-(diethylamino) coumarin-3-carboxamide side-chain improved glucose control in human peripheral adipocytes and the endothelial brain barrier cells by activation of insulin-insensitive glucose transporter 1 (GLUT1). AAC2 interacted specifically with the leptin receptor (LepR) and activated atypical protein kinase C zeta (PKCς) to increase glucose uptake. The effects induced by AAC2 were absent in leptin receptor-deficient predipocytes and in Leprdb mice. In contrast, AAC2 established glycemic control altering food intake in leptin-deficient Lepob mice. Therefore, AAC2 activated the LepR and acted in a cytokine-like manner distinct from leptin. In a monogenic Ins2Akita mouse model for the phenotypes associated with type 1 diabetes, AAC2 rescued systemic glucose uptake in these mice without an increase in insulin levels and adiposity, as seen in insulin-treated Ins2Akita mice. In contrast to insulin, AAC2 treatment increased brain mass and reduced anxiety-related behavior in Ins2Akita mice. Our data suggests that the unique mechanism of action for AAC2, activating LepR/PKCς/GLUT1 axis, offers an effective strategy to broaden glycemic control for the prevention of diabetic complications of the nervous system and, possibly, other insulin insensitive or resistant tissues.
Collapse
|
8
|
Green CL, Mitchell SE, Derous D, Wang Y, Chen L, Han JDJ, Promislow DEL, Lusseau D, Douglas A, Speakman JR. The Effects of Graded Levels of Calorie Restriction: XIV. Global Metabolomics Screen Reveals Brown Adipose Tissue Changes in Amino Acids, Catecholamines, and Antioxidants After Short-Term Restriction in C57BL/6 Mice. J Gerontol A Biol Sci Med Sci 2020; 75:218-229. [PMID: 31220223 PMCID: PMC7530471 DOI: 10.1093/gerona/glz023] [Citation(s) in RCA: 10] [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: 07/25/2018] [Indexed: 12/15/2022] Open
Abstract
Animals undergoing calorie restriction (CR) often lower their body temperature to conserve energy. Brown adipose tissue (BAT) is stimulated through norepinephrine when rapid heat production is needed, as it is highly metabolically active due to the uncoupling of the electron transport chain from ATP synthesis. To better understand how BAT metabolism changes with CR, we used metabolomics to identify 883 metabolites that were significantly differentially expressed in the BAT of C57BL/6 mice, fed graded CR (10%, 20%, 30%, and 40% CR relative to their individual baseline intake), compared with mice fed ad libitum (AL) for 12 hours a day. Pathway analysis revealed that graded CR had an impact on the TCA cycle and fatty acid degradation. In addition, an increase in nucleic acids and catecholamine pathways was seen with graded CR in the BAT metabolome. We saw increases in antioxidants with CR, suggesting a beneficial effect of mitochondrial uncoupling. Importantly, the instigator of BAT activation, norepinephrine, was increased with CR, whereas its precursors l-tyrosine and dopamine were decreased, indicating a shift of metabolites through the activation pathway. Several of these key changes were correlated with food anticipatory activity and body temperature, indicating BAT activation may be driven by responses to hunger.
Collapse
Affiliation(s)
- Cara L Green
- School of Biological Sciences, Institute of Biological and Environmental Sciences, University of Aberdeen, Scotland, UK
| | - Sharon E Mitchell
- School of Biological Sciences, Institute of Biological and Environmental Sciences, University of Aberdeen, Scotland, UK
| | - Davina Derous
- School of Biological Sciences, Institute of Biological and Environmental Sciences, University of Aberdeen, Scotland, UK
| | - Yingchun Wang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, China
| | - Luonan Chen
- Key Laboratory of Systems Biology, Innovation Center for Cell Signaling Network, Institute of Biochemistry and Cell Biology, China
| | - Jing-Dong J Han
- Chinese Academy of Sciences Key Laboratory of Computational Biology, Chinese Academy of Sciences-Max Planck Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, China
| | - Daniel E L Promislow
- Department of Pathology and Department of Biology, University of Washington at Seattle
| | - David Lusseau
- School of Biological Sciences, Institute of Biological and Environmental Sciences, University of Aberdeen, Scotland, UK
| | - Alex Douglas
- School of Biological Sciences, Institute of Biological and Environmental Sciences, University of Aberdeen, Scotland, UK
| | - John R Speakman
- School of Biological Sciences, Institute of Biological and Environmental Sciences, University of Aberdeen, Scotland, UK
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, China
| |
Collapse
|
9
|
Abstract
Starvation arouses evolved protective mechanisms including binge eating and increased metabolic efficiency and fat storage. When aroused by dieting, the experiences of out-of-control eating, increased appetite, and increased fat storage arouse greater fears of obesity, spurring renewed attempts to restrict intake severely. The resulting positive feedback cycle escalates into bulimia for many, and anorexia in a few.
Collapse
|
10
|
Templeman NM, Flibotte S, Chik JHL, Sinha S, Lim GE, Foster LJ, Nislow C, Johnson JD. Reduced Circulating Insulin Enhances Insulin Sensitivity in Old Mice and Extends Lifespan. Cell Rep 2018; 20:451-463. [PMID: 28700945 DOI: 10.1016/j.celrep.2017.06.048] [Citation(s) in RCA: 96] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Revised: 05/01/2017] [Accepted: 06/19/2017] [Indexed: 12/20/2022] Open
Abstract
The causal relationships between insulin levels, insulin resistance, and longevity are not fully elucidated. Genetic downregulation of insulin/insulin-like growth factor 1 (Igf1) signaling components can extend invertebrate and mammalian lifespan, but insulin resistance, a natural form of decreased insulin signaling, is associated with greater risk of age-related disease in mammals. We compared Ins2+/- mice to Ins2+/+ littermate controls, on a genetically stable Ins1 null background. Proteomic and transcriptomic analyses of livers from 25-week-old mice suggested potential for healthier aging and altered insulin sensitivity in Ins2+/- mice. Halving Ins2 lowered circulating insulin by 25%-34% in aged female mice, without altering Igf1 or circulating Igf1. Remarkably, decreased insulin led to lower fasting glucose and improved insulin sensitivity in aged mice. Moreover, lowered insulin caused significant lifespan extension, observed across two diverse diets. Our study indicates that elevated insulin contributes to age-dependent insulin resistance and that limiting basal insulin levels can extend lifespan.
Collapse
Affiliation(s)
- Nicole M Templeman
- Department of Cellular and Physiological Sciences, Diabetes Research Group, Life Sciences Institute, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Stephane Flibotte
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Jenny H L Chik
- Department of Biochemistry and Molecular Biology, Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Sunita Sinha
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Gareth E Lim
- Department of Cellular and Physiological Sciences, Diabetes Research Group, Life Sciences Institute, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Leonard J Foster
- Department of Biochemistry and Molecular Biology, Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Corey Nislow
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - James D Johnson
- Department of Cellular and Physiological Sciences, Diabetes Research Group, Life Sciences Institute, University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
| |
Collapse
|
11
|
Dommerholt MB, Dionne DA, Hutchinson DF, Kruit JK, Johnson JD. Metabolic effects of short-term caloric restriction in mice with reduced insulin gene dosage. J Endocrinol 2018; 237:59-71. [PMID: 29439088 DOI: 10.1530/joe-17-0505] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 02/08/2018] [Indexed: 11/08/2022]
Abstract
Caloric restriction (CR) is the only environmental intervention with robust evidence that it extends lifespan and delays the symptoms of aging, but its mechanisms are incompletely understood. Based on the prolonged longevity of knockout models, it was hypothesized that the insulin-IGF pathway could be a target for developing a CR mimic. This study aimed to test whether CR has additive effects on glucose homeostasis and beta-cell function in mice with reduced insulin gene dosage. To study models with a range of basal insulin levels, wild-type C57BL/6J and mice on an Ins2-/- background, were put on 8 weeks of 40% CR at various ages. Both male and female mice rapidly lost weight due to a reduced WAT mass. Glucose tolerance was improved and fasting glucose levels were reduced by CR in both wild type and 45- and 70-week-old Ins2-/- mice. The effects of CR and reduced insulin on glucose tolerance were non-additive in 20-week-old mice. Interestingly, mice on CR generally exhibited an inability to further depress blood glucose after insulin injection, pointing to possible alterations in insulin sensitivity. In conclusion, our results demonstrate that CR can cause weight loss in the context of reduced insulin production, but that CR-improved glucose homeostasis does not occur near the 'insulin floor' in young mice. Collectively, these data shed further light on the relationships between CR, insulin and glucose homeostasis.
Collapse
Affiliation(s)
- Marleen B Dommerholt
- Department of Cellular and Physiological SciencesUniversity of British Columbia, Vancouver, Canada
- Department of PediatricsUniversity Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Derek A Dionne
- Department of Cellular and Physiological SciencesUniversity of British Columbia, Vancouver, Canada
| | - Daria F Hutchinson
- Department of Cellular and Physiological SciencesUniversity of British Columbia, Vancouver, Canada
| | - Janine K Kruit
- Department of PediatricsUniversity Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - James D Johnson
- Department of Cellular and Physiological SciencesUniversity of British Columbia, Vancouver, Canada
| |
Collapse
|
12
|
Morita I, Tanimoto K, Akiyama N, Naya N, Fujieda K, Iwasaki T, Yukioka H. Chronic hyperinsulinemia contributes to insulin resistance under dietary restriction in association with altered lipid metabolism in Zucker diabetic fatty rats. Am J Physiol Endocrinol Metab 2017; 312:E264-E272. [PMID: 28143857 DOI: 10.1152/ajpendo.00342.2016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 01/06/2017] [Accepted: 01/23/2017] [Indexed: 12/14/2022]
Abstract
Hyperinsulinemia is widely thought to be a compensatory response to insulin resistance, whereas its potentially causal role in the progression of insulin resistance remains to be established. Here, we aimed to examine whether hyperinsulinemia could affect the progression of insulin resistance in Zucker fatty diabetic (ZDF) rats. Male ZDF rats at 8 wk of age were fed a diet ad libitum (AL) or dietary restriction (DR) of either 15 or 30% from AL feeding over 6 wk. Insulin sensitivity was determined by hyperinsulinemic euglycemic clamp. ZDF rats in the AL group progressively developed hyperglycemia and hyperinsulinemia by 10 wk of age, and then plasma insulin rapidly declined to nearly normal levels by 12 wk of age. Compared with AL group, DR groups showed delayed onset of hyperglycemia and persistent hyperinsulinemia, leading to weight gain and raised plasma triglycerides and free fatty acids by 14 wk of age. Notably, insulin sensitivity was significantly reduced in the DR group rather than the AL group and inversely correlated with plasma levels of insulin and triglyceride but not glucose. Moreover, enhanced lipid deposition and upregulation of genes involved in lipogenesis were detected in liver, skeletal muscle, and adipose tissues of the DR group rather than the AL group. Alternatively, continuous hyperinsulinemia induced by insulin pellet implantation produced a decrease in insulin sensitivity in ZDF rats. These results suggest that chronic hyperinsulinemia may lead to the progression of insulin resistance under DR conditions in association with altered lipid metabolism in peripheral tissues in ZDF rats.
Collapse
Affiliation(s)
- Ippei Morita
- Drug Discovery and Disease Research Laboratory, Shionogi and Company, Ltd., Osaka, Japan
| | - Keiichi Tanimoto
- Drug Discovery and Disease Research Laboratory, Shionogi and Company, Ltd., Osaka, Japan
| | - Nobuteru Akiyama
- Drug Discovery and Disease Research Laboratory, Shionogi and Company, Ltd., Osaka, Japan
| | - Noriyuki Naya
- Drug Discovery and Disease Research Laboratory, Shionogi and Company, Ltd., Osaka, Japan
| | - Kumiko Fujieda
- Drug Discovery and Disease Research Laboratory, Shionogi and Company, Ltd., Osaka, Japan
| | - Takanori Iwasaki
- Drug Discovery and Disease Research Laboratory, Shionogi and Company, Ltd., Osaka, Japan
| | - Hideo Yukioka
- Drug Discovery and Disease Research Laboratory, Shionogi and Company, Ltd., Osaka, Japan
| |
Collapse
|
13
|
Templeman NM, Skovsø S, Page MM, Lim GE, Johnson JD. A causal role for hyperinsulinemia in obesity. J Endocrinol 2017; 232:R173-R183. [PMID: 28052999 DOI: 10.1530/joe-16-0449] [Citation(s) in RCA: 106] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 01/03/2017] [Indexed: 12/13/2022]
Abstract
Insulin modulates the biochemical pathways controlling lipid uptake, lipolysis and lipogenesis at multiple levels. Elevated insulin levels are associated with obesity, and conversely, dietary and pharmacological manipulations that reduce insulin have occasionally been reported to cause weight loss. However, the causal role of insulin hypersecretion in the development of mammalian obesity remained controversial in the absence of direct loss-of-function experiments. Here, we discuss theoretical considerations around the causal role of excess insulin for obesity, as well as recent studies employing mice that are genetically incapable of the rapid and sustained hyperinsulinemia that normally accompanies a high-fat diet. We also discuss new evidence demonstrating that modest reductions in circulating insulin prevent weight gain, with sustained effects that can persist after insulin levels normalize. Importantly, evidence from long-term studies reveals that a modest reduction in circulating insulin is not associated with impaired glucose homeostasis, meaning that body weight and lipid homeostasis are actually more sensitive to small changes in circulating insulin than glucose homeostasis in these models. Collectively, the evidence from new studies on genetic loss-of-function models forces a re-evaluation of current paradigms related to obesity, insulin resistance and diabetes. The potential for translation of these findings to humans is briefly discussed.
Collapse
Affiliation(s)
- Nicole M Templeman
- Department of Cellular and Physiological SciencesDiabetes Research Group, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Søs Skovsø
- Department of Cellular and Physiological SciencesDiabetes Research Group, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Melissa M Page
- Department of Cellular and Physiological SciencesDiabetes Research Group, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Gareth E Lim
- Department of Cellular and Physiological SciencesDiabetes Research Group, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - James D Johnson
- Department of Cellular and Physiological SciencesDiabetes Research Group, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
- Institute for Personalized Therapeutic NutritionVancouver, British Columbia, Canada
| |
Collapse
|
14
|
Short-term moderate diet restriction in adulthood can reverse oxidative, cardiovascular and metabolic alterations induced by postnatal overfeeding in mice. Sci Rep 2016; 6:30817. [PMID: 27465434 PMCID: PMC4964358 DOI: 10.1038/srep30817] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 07/11/2016] [Indexed: 01/21/2023] Open
Abstract
We aimed to determine whether moderate diet restriction could restore cardiac, oxidative and metabolic alterations induced by postnatal overfeeding (PNOF). Litters of C57BL/6 male mice were either maintained at 9 (normal litter, NL), or reduced to 3 (small litter, SL) in order to induce PNOF. At 6 months, half of the NL and SL mice were subjected to 20% calorie-restriction (CR: NLCR, SLCR) for one month, while the other half continued to eat ad libitum (AL: NLAL, SLAL). Six-month old SL mice presented overweight, fat accumulation, hyperleptinemia, glucose intolerance, insulin resistance, increased cardiac ROS production and decreased left ventricular ejection fraction (LVEF). After CR, SL mice body weight was normalized; however, their fat mass and leptinemia were not decreased, glucose metabolism was improved and LVEF was increased. In SL mice, CR increased the cardiac mitochondrial respiratory rate and decreased cardiac ROS production. Hearts from SLCR mice showed better recovery and smaller postischemic infarct size. Intriguingly, no difference was observed between NLAL and NLCR mice for most of the parameters investigated. Short-term moderate CR not only normalized body weight in SL mice but also improved metabolic programming and reversed oxidative and cardiac dysfunction induced by PNOF.
Collapse
|