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Batdorf HM, Lawes LDL, Cassagne GA, Fontenot MS, Harvey IC, Richardson JT, Burk DH, Dupuy SD, Karlstad MD, Salbaum JM, Staszkiewicz J, Beyl R, Ghosh S, Burke SJ, Collier JJ. Accelerated onset of diabetes in non-obese diabetic mice fed a refined high-fat diet. Diabetes Obes Metab 2024. [PMID: 38433703 DOI: 10.1111/dom.15522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 02/09/2024] [Accepted: 02/11/2024] [Indexed: 03/05/2024]
Abstract
AIM Type 1 diabetes results from autoimmune events influenced by environmental variables, including changes in diet. This study investigated how feeding refined versus unrefined (aka 'chow') diets affects the onset and progression of hyperglycaemia in non-obese diabetic (NOD) mice. METHODS Female NOD mice were fed either unrefined diets or matched refined low- and high-fat diets. The onset of hyperglycaemia, glucose tolerance, food intake, energy expenditure, circulating insulin, liver gene expression and microbiome changes were measured for each dietary group. RESULTS NOD mice consuming unrefined (chow) diets developed hyperglycaemia at similar frequencies. By contrast, mice consuming the defined high-fat diet had an accelerated onset of hyperglycaemia compared to the matched low-fat diet. There was no change in food intake, energy expenditure, or physical activity within each respective dietary group. Microbiome changes were driven by diet type, with chow diets clustering similarly, while refined low- and high-fat bacterial diversity also grouped closely. In the defined dietary cohort, liver gene expression changes in high-fat-fed mice were consistent with a greater frequency of hyperglycaemia and impaired glucose tolerance. CONCLUSION Glucose intolerance is associated with an enhanced frequency of hyperglycaemia in female NOD mice fed a defined high-fat diet. Using an appropriate matched control diet is an essential experimental variable when studying changes in microbiome composition and diet as a modifier of disease risk.
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Affiliation(s)
- Heidi M Batdorf
- Pennington Biomedical Research Center, Baton Rouge, Louisiana, USA
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, USA
| | | | | | - Molly S Fontenot
- Pennington Biomedical Research Center, Baton Rouge, Louisiana, USA
| | | | | | - David H Burk
- Pennington Biomedical Research Center, Baton Rouge, Louisiana, USA
| | - Samuel D Dupuy
- Department of Surgery, University of Tennessee Health Science Center, Graduate School of Medicine, Knoxville, Tennessee, USA
| | - Michael D Karlstad
- Department of Surgery, University of Tennessee Health Science Center, Graduate School of Medicine, Knoxville, Tennessee, USA
| | | | | | - Robbie Beyl
- Pennington Biomedical Research Center, Baton Rouge, Louisiana, USA
| | - Sujoy Ghosh
- Pennington Biomedical Research Center, Baton Rouge, Louisiana, USA
| | - Susan J Burke
- Pennington Biomedical Research Center, Baton Rouge, Louisiana, USA
| | - J Jason Collier
- Pennington Biomedical Research Center, Baton Rouge, Louisiana, USA
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, USA
- Present address: Louisiana State University School of Medicine, New Orleans, LA, USA
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Batdorf HM, Lawes LDL, Richardson JT, Burk DH, Dupuy SD, Karlstad MD, Noland RC, Burke SJ, Collier JJ. NOD mice have distinct metabolic and immunologic profiles when compared with genetically similar MHC-matched ICR mice. Am J Physiol Endocrinol Metab 2023; 325:E336-E345. [PMID: 37610410 PMCID: PMC10642984 DOI: 10.1152/ajpendo.00033.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 08/18/2023] [Accepted: 08/18/2023] [Indexed: 08/24/2023]
Abstract
Nonobese diabetic (NOD) mice are the most commonly used rodent model to study mechanisms relevant to the autoimmunity and immunology of type 1 diabetes. Although many different strains of mice have been used as controls for studies comparing nondiabetic lines to the NOD strain, we hypothesized that the parental strain that gave rise to the NOD line might be one of the best options. Therefore, we compared female ICR and NOD mice, which are matched at key major histocompatibility complex (MHC) loci, to understand their metabolic and immunologic similarities and differences. Several novel observations emerged: 1) NOD mice have greater circulating proinsulin when compared with ICR mice. 2) NOD mice display CD3+ and IBA1+ cell infiltration into and near pancreatic islets before hyperglycemia. 3) NOD mice show increased expression of the Il1b and Cxcl11 genes in islets when compared with islets from age-matched ICR mice. 4) NOD mice have a greater abundance of STAT1 and ICAM-1 protein in islets when compared with ICR mice. These data show that ICR mice, which are genetically similar to NOD mice, do not retain the same immunologic outcomes. Thus, ICR mice are an excellent choice as a genetically similar and MHC-matched control for NOD mice in studies designed to understand mechanisms relevant to autoimmune-mediated diabetes onset as well as novel therapeutic interventions.NEW & NOTEWORTHY Nonobese diabetic (NOD) mice have more proinsulin in circulation and STAT1 protein in islets compared with the major histocompatibility complex (MHC)-matched ICR line. NOD mice also display greater expression of cytokines and chemokines in pancreatic islets consistent with immune cell infiltration before hyperglycemia when compared with age-matched ICR mice. Thus, ICR mice represent an excellent control for autoimmunity and inflammation studies using the NOD line of mice.
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Affiliation(s)
- Heidi M Batdorf
- Laboratory of Islet Biology and Inflammation, Pennington Biomedical Research Center, Baton Rouge, Louisiana, United States
| | - Luz de Luna Lawes
- Laboratory of Islet Biology and Inflammation, Pennington Biomedical Research Center, Baton Rouge, Louisiana, United States
| | - Jeremy T Richardson
- Laboratory of Islet Biology and Inflammation, Pennington Biomedical Research Center, Baton Rouge, Louisiana, United States
| | - David H Burk
- Cell Biology and Bioimaging Core Facility, Pennington Biomedical Research Center, Baton Rouge, Louisiana, United States
| | - Samuel D Dupuy
- Department of Surgery, Graduate School of Medicine, University of Tennessee Health Science Center, Knoxville, Tennessee, United States
| | - Michael D Karlstad
- Department of Surgery, Graduate School of Medicine, University of Tennessee Health Science Center, Knoxville, Tennessee, United States
| | - Robert C Noland
- Skeletal Muscle Metabolism Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana, United States
| | - Susan J Burke
- Laboratory of Immunogenetics, Pennington Biomedical Research Center, Baton Rouge, Louisiana, United States
| | - J Jason Collier
- Laboratory of Islet Biology and Inflammation, Pennington Biomedical Research Center, Baton Rouge, Louisiana, United States
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Linden MA, Burke SJ, Pirzadah HA, Huang TY, Batdorf HM, Mohammed WK, Jones KA, Ghosh S, Campagna SR, Collier JJ, Noland RC. Pharmacological inhibition of lipolysis prevents adverse metabolic outcomes during glucocorticoid administration. Mol Metab 2023; 74:101751. [PMID: 37295745 PMCID: PMC10300254 DOI: 10.1016/j.molmet.2023.101751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 06/01/2023] [Accepted: 06/06/2023] [Indexed: 06/12/2023] Open
Abstract
OBJECTIVE Glucocorticoids are one of the most commonly prescribed classes of anti-inflammatory drugs; however, chronic treatment promotes iatrogenic (drug-induced) diabetes. As part of their physiological role, glucocorticoids stimulate lipolysis to spare glucose. We hypothesized that persistent stimulation of lipolysis during glucocorticoid therapy plays a causative role in the development of iatrogenic diabetes. METHODS Male C57BL/6J mice were given 100 μg/mL corticosterone (Cort) in the drinking water for two weeks and were fed either normal chow (TekLad 8640) or the same diet supplemented with an adipose triglyceride lipase inhibitor (Atglistatin - 2 g/kg diet) to inhibit the first step of lipolysis. RESULTS Herein, we report for the first time that glucocorticoid administration promotes a unique state of substrate excess and energetic overload in skeletal muscle that primarily results from the rampant mobilization of endogenous fuels. Inhibiting lipolysis protected mice from Cort-induced gains in fat mass, excess ectopic lipid accrual, hyperinsulinemia, and hyperglycemia. The role lipolysis plays in Cort-mediated pathology appears to differ between tissues. Within skeletal muscle, Cort-induced lipolysis facilitated diversion of glucose-derived carbons toward the pentose phosphate and hexosamine biosynthesis pathways but contributed to <3% of the Cort-induced genomic adaptations. In contrast, Cort stimulation of lipolysis accounted for ∼35% of the genomic changes in the liver but had minimal impact on hepatic metabolites reported. CONCLUSIONS These data support the idea that activation of lipolysis plays a causal role in the progression toward iatrogenic diabetes during glucocorticoid therapy with differential impact on skeletal muscle and liver.
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Affiliation(s)
- Melissa A Linden
- Skeletal Muscle Metabolism Laboratory, Pennington Biomedical Research Center, Baton Rouge, LA, 70808, USA; Department of Exercise and Health Sciences, University of Massachusetts-Boston, Boston, MA, 02125, USA.
| | - Susan J Burke
- Laboratory of Immunogenetics, Pennington Biomedical Research Center, Baton Rouge, LA, 70808, USA.
| | - Humza A Pirzadah
- Skeletal Muscle Metabolism Laboratory, Pennington Biomedical Research Center, Baton Rouge, LA, 70808, USA.
| | - Tai-Yu Huang
- Skeletal Muscle Metabolism Laboratory, Pennington Biomedical Research Center, Baton Rouge, LA, 70808, USA.
| | - Heidi M Batdorf
- Laboratory of Islet Biology and Inflammation, Pennington Biomedical Research Center, Baton Rouge, LA, 70808, USA.
| | - Walid K Mohammed
- Skeletal Muscle Metabolism Laboratory, Pennington Biomedical Research Center, Baton Rouge, LA, 70808, USA.
| | - Katarina A Jones
- Biological and Small Molecule Mass Spectrometry Core, University of Tennessee, Knoxville, TN, 37916, USA.
| | - Sujoy Ghosh
- Laboratory of Computational Biology, Pennington Biomedical Research Center, Baton Rouge, LA, 70808, USA; Program in Cardiovascular and Metabolic Disorders and Center for Computational Biology, Duke-National University of Singapore Medical School, Singapore, 169857, Singapore.
| | - Shawn R Campagna
- Biological and Small Molecule Mass Spectrometry Core, University of Tennessee, Knoxville, TN, 37916, USA.
| | - J Jason Collier
- Laboratory of Islet Biology and Inflammation, Pennington Biomedical Research Center, Baton Rouge, LA, 70808, USA.
| | - Robert C Noland
- Skeletal Muscle Metabolism Laboratory, Pennington Biomedical Research Center, Baton Rouge, LA, 70808, USA.
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Martin TM, Burke SJ, Batdorf HM, Burk DH, Ghosh S, Dupuy SD, Karlstad MD, Collier JJ. ICAM-1 Abundance Is Increased in Pancreatic Islets of Hyperglycemic Female NOD Mice and Is Rapidly Upregulated by NF-κB in Pancreatic β-Cells. J Immunol 2022; 209:569-581. [PMID: 35851539 PMCID: PMC9845432 DOI: 10.4049/jimmunol.2200065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 05/24/2022] [Indexed: 01/04/2023]
Abstract
Type 1 diabetes (T1D) is classified as an autoimmune disease where pancreatic β-cells are specifically targeted by cells of the immune system. The molecular mechanisms underlying this process are not completely understood. Herein, we identified that the Icam1 gene and ICAM-1 protein were selectively elevated in female NOD mice relative to male mice, fitting with the sexual dimorphism of diabetes onset in this key mouse model of T1D. In addition, ICAM-1 abundance was greater in hyperglycemic female NOD mice than in age-matched normoglycemic female NOD mice. Moreover, we discovered that the Icam1 gene was rapidly upregulated in response to IL-1β in mouse, rat, and human islets and in 832/13 rat insulinoma cells. This early temporal genetic regulation requires key components of the NF-κB pathway and was associated with rapid recruitment of the p65 transcriptional subunit of NF-κB to corresponding κB elements within the Icam1 gene promoter. In addition, RNA polymerase II recruitment to the Icam1 gene promoter in response to IL-1β was consistent with p65 occupancy at κB elements, histone chemical modifications, and increased mRNA abundance. Thus, we conclude that β-cells undergo rapid genetic reprogramming by IL-1β to enhance expression of the Icam1 gene and that elevations in ICAM-1 are associated with hyperglycemia in NOD mice. These findings are highly relevant to, and highlight the importance of, pancreatic β-cell communication with the immune system. Collectively, these observations reveal a portion of the complex molecular events associated with onset and progression of T1D.
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Affiliation(s)
- Thomas M. Martin
- Laboratory of Islet Biology and Inflammation, Pennington Biomedical Research Center Baton Rouge LA 70808 USA
| | - Susan J. Burke
- Laboratory of Immunogenetics, Pennington Biomedical Research Center Baton Rouge LA 70808 USA
| | - Heidi M. Batdorf
- Laboratory of Islet Biology and Inflammation, Pennington Biomedical Research Center Baton Rouge LA 70808 USA
| | - David H. Burk
- Cell Biology and Bioimaging Core, Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA
| | - Sujoy Ghosh
- Laboratory of Computational Biology, Pennington Biomedical Research Center, Baton Rouge, LA, United States
- Centre for Computational Biology and Program in Cardiovascular and Metabolic Disorders, Duke NUS Medical School, Singapore
| | - Samuel D. Dupuy
- Department of Surgery, University of Tennessee Health Science Center, Knoxville, TN, 37920, USA
| | - Michael D. Karlstad
- Department of Surgery, University of Tennessee Health Science Center, Knoxville, TN, 37920, USA
| | - J. Jason Collier
- Laboratory of Islet Biology and Inflammation, Pennington Biomedical Research Center Baton Rouge LA 70808 USA
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Smoak P, Burke SJ, Martin TM, Batdorf HM, Floyd ZE, Collier JJ. Artemisia dracunculus L. Ethanolic Extract and an Isolated Component, DMC2, Ameliorate Inflammatory Signaling in Pancreatic β-Cells via Inhibition of p38 MAPK. Biomolecules 2022; 12:biom12050708. [PMID: 35625635 PMCID: PMC9139089 DOI: 10.3390/biom12050708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 05/09/2022] [Accepted: 05/13/2022] [Indexed: 02/01/2023] Open
Abstract
Non-resolving pancreatic islet inflammation is widely viewed as a contributor to decreases in β-cell mass and function that occur in both Type 1 and Type 2 diabetes. Therefore, strategies aimed at reducing or eliminating pathological inflammation would be useful to protect islet β-cells. Herein, we described the use of 2′,4′-dihydroxy-4-methoxydihydrochalcone (DMC2), a bioactive molecule isolated from an ethanolic extract of Artemisia dracunculus L., as a novel anti-inflammatory agent. The ethanolic extract, termed PMI 5011, reduced IL-1β-mediated NF-κB activity. DMC2 retained this ability, indicating this compound as the likely source of anti-inflammatory activity within the overall PMI 5011 extract. We further examined NF-κB activity using promoter-luciferase reporter constructs, Western blots, mRNA abundance, and protein secretion. Specifically, we found that PMI 5011 and DMC2 each reduced the ability of IL-1β to promote increases in the expression of the Ccl2 and Ccl20 genes. These genes encode proteins that promote immune cell recruitment and are secreted by β-cells in response to IL-1β. Phosphorylation of IκBα and the p65 subunit of NF-κB were not reduced by either PMI 5011 or DMC2; however, phosphorylation of p38 MAPK was blunted in the presence of DMC2. Finally, we observed that while PMI 5011 impaired glucose-stimulated insulin secretion, insulin output was preserved in the presence of DMC2. In conclusion, PMI 5011 and DMC2 reduced inflammation, but only DMC2 did so with the preservation of glucose-stimulated insulin secretion.
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Affiliation(s)
- Peter Smoak
- Laboratory of Islet Biology and Inflammation, Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA; (P.S.); (T.M.M.); (H.M.B.)
| | - Susan J. Burke
- Laboratory of Immunogenetics, Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA;
| | - Thomas M. Martin
- Laboratory of Islet Biology and Inflammation, Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA; (P.S.); (T.M.M.); (H.M.B.)
| | - Heidi M. Batdorf
- Laboratory of Islet Biology and Inflammation, Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA; (P.S.); (T.M.M.); (H.M.B.)
| | - Z. Elizabeth Floyd
- Laboratory of Ubitquitin Biology, Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA;
| | - J. Jason Collier
- Laboratory of Islet Biology and Inflammation, Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA; (P.S.); (T.M.M.); (H.M.B.)
- Correspondence:
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6
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Huang TY, Linden MA, Fuller SE, Goldsmith FR, Simon J, Batdorf HM, Scott MC, Essajee NM, Brown JM, Noland RC. Combined effects of a ketogenic diet and exercise training alter mitochondrial and peroxisomal substrate oxidative capacity in skeletal muscle. Am J Physiol Endocrinol Metab 2021; 320:E1053-E1067. [PMID: 33843280 PMCID: PMC8285595 DOI: 10.1152/ajpendo.00410.2020] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Ketogenic diets (KDs) are reported to improve body weight, fat mass, and exercise performance in humans. Unfortunately, most rodent studies have used a low-protein KD, which does not recapitulate diets used by humans. Since skeletal muscle plays a critical role in responding to macronutrient perturbations induced by diet and exercise, the purpose of this study was to test if a normal-protein KD (NPKD) impacts shifts in skeletal muscle substrate oxidative capacity in response to exercise training (ExTr). A high fat, carbohydrate-deficient NPKD (16.1% protein, 83.9% fat, 0% carbohydrate) was given to C57BL/6J male mice for 6 wk, whereas controls (Con) received a low-fat diet with similar protein (15.9% protein, 11.9% fat, 72.2% carbohydrate). After 3 wk on the diet, mice began treadmill training 5 days/wk, 60 min/day for 3 wks. The NPKD increased body weight and fat mass, whereas ExTr negated a continued rise in adiposity. ExTr increased intramuscular glycogen, whereas the NPKD increased intramuscular triglycerides. Neither the NPKD nor ExTr alone altered mitochondrial content; however, in combination, the NPKD-ExTr group showed increases in PGC-1α and markers of mitochondrial fission/fusion. Pyruvate oxidative capacity was unchanged by either intervention, whereas ExTr increased leucine oxidation in NPKD-fed mice. Lipid metabolism pathways had the most notable changes as the NPKD and ExTr interventions both enhanced mitochondrial and peroxisomal lipid oxidation and many adaptations were additive or synergistic. Overall, these results suggest that a combination of a NPKD and ExTr induces additive and/or synergistic adaptations in skeletal muscle oxidative capacity.NEW & NOTEWORTHY A ketogenic diet with normal protein content (NPKD) increases body weight and fat mass, increases intramuscular triglyceride storage, and upregulates pathways related to protein metabolism. In combination with exercise training, a NPKD induces additive and/or synergistic activation of AMPK, PGC-1α, mitochondrial fission/fusion genes, mitochondrial fatty acid oxidation, and peroxisomal adaptations in skeletal muscle. Collectively, results from this study provide mechanistic insight into adaptations in skeletal muscle relevant to keto-adaptation.
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Affiliation(s)
- Tai-Yu Huang
- Skeletal Muscle Metabolism Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Melissa A Linden
- Skeletal Muscle Metabolism Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Scott E Fuller
- Skeletal Muscle Metabolism Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Felicia R Goldsmith
- Skeletal Muscle Metabolism Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Jacob Simon
- Skeletal Muscle Metabolism Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Heidi M Batdorf
- Skeletal Muscle Metabolism Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Matthew C Scott
- Skeletal Muscle Metabolism Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Nabil M Essajee
- Skeletal Muscle Metabolism Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - John M Brown
- Skeletal Muscle Metabolism Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Robert C Noland
- Skeletal Muscle Metabolism Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana
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Collier JJ, Batdorf HM, Martin TM, Rohli KE, Burk DH, Lu D, Cooley CR, Karlstad MD, Jackson JW, Sparer TE, Zhang J, Mynatt RL, Burke SJ. Pancreatic, but not myeloid-cell, expression of interleukin-1alpha is required for maintenance of insulin secretion and whole body glucose homeostasis. Mol Metab 2021; 44:101140. [PMID: 33285301 PMCID: PMC7772372 DOI: 10.1016/j.molmet.2020.101140] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 11/03/2020] [Accepted: 12/02/2020] [Indexed: 02/07/2023] Open
Abstract
OBJECTIVE The expression of the interleukin-1 receptor type I (IL-1R) is enriched in pancreatic islet β-cells, signifying that ligands activating this pathway are important for the health and function of the insulin-secreting cell. Using isolated mouse, rat, and human islets, we identified the cytokine IL-1α as a highly inducible gene in response to IL-1R activation. In addition, IL-1α is elevated in mouse and rat models of obesity and Type 2 diabetes. Since less is known about the biology of IL-1α relative to IL-1β in pancreatic tissue, our objective was to investigate the contribution of IL-1α to pancreatic β-cell function and overall glucose homeostasis in vivo. METHODS We generated a novel mouse line with conditional IL-1α alleles and subsequently produced mice with either pancreatic- or myeloid lineage-specific deletion of IL-1α. RESULTS Using this in vivo approach, we discovered that pancreatic (IL-1αPdx1-/-), but not myeloid-cell, expression of IL-1α (IL-1αLysM-/-) was required for the maintenance of whole body glucose homeostasis in both male and female mice. Moreover, pancreatic deletion of IL-1α led to impaired glucose tolerance with no change in insulin sensitivity. This observation was consistent with our finding that glucose-stimulated insulin secretion was reduced in islets isolated from IL-1αPdx1-/- mice. Alternatively, IL-1αLysM-/- mice (male and female) did not have any detectable changes in glucose tolerance, respiratory quotient, physical activity, or food intake when compared with littermate controls. CONCLUSIONS Taken together, we conclude that there is an important physiological role for pancreatic IL-1α to promote glucose homeostasis by supporting glucose-stimulated insulin secretion and islet β-cell mass in vivo.
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Affiliation(s)
- J Jason Collier
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA, 70808, USA; Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, 70803, USA
| | - Heidi M Batdorf
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA, 70808, USA
| | - Thomas M Martin
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA, 70808, USA; Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, 70803, USA
| | - Kristen E Rohli
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA, 70808, USA
| | - David H Burk
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA, 70808, USA
| | - Danhong Lu
- Sarah W. Stedman Nutrition and Metabolism Center, Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC, 27704, USA
| | - Chris R Cooley
- Department of Surgery, University of Tennessee Health Science Center, Knoxville, TN, 37920, USA
| | - Michael D Karlstad
- Department of Surgery, University of Tennessee Health Science Center, Knoxville, TN, 37920, USA
| | - Joseph W Jackson
- Department of Microbiology, University of Tennessee, Knoxville, TN, 37996, USA
| | - Tim E Sparer
- Department of Microbiology, University of Tennessee, Knoxville, TN, 37996, USA
| | - Jingying Zhang
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA, 70808, USA
| | - Randall L Mynatt
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA, 70808, USA
| | - Susan J Burke
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA, 70808, USA.
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8
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Collier JJ, Batdorf HM, Mendoza TM, Burk DH, Martin TM, Zhang J, Mynatt RL, Burke SJ. Hepatic IKKε expression is dispensable for high-fat feeding-induced increases in liver lipid content and alterations in glucose tolerance. Am J Physiol Endocrinol Metab 2020; 318:E11-E21. [PMID: 31661298 PMCID: PMC6985790 DOI: 10.1152/ajpendo.00309.2019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
There are endocrine and immunological changes that occur during onset and progression of the overweight and obese states. The inhibitor of nuclear factor-κB kinase-ε (IKKε) was originally described as an inducible protein kinase; whole body gene deletion or systemic pharmaceutical targeting of this kinase improved insulin sensitivity and glucose tolerance in mice. To investigate the primary sites of action associated with IKKε during weight gain, we describe the first mouse line with conditional elimination of IKKε in the liver (IKKεAlb-/-). IKKεAlb-/- mice and littermate controls gain weight, show similar changes in body composition, and do not display any improvements in insulin sensitivity or whole body glucose tolerance. These studies were conducted using breeder chow diets and matched low- vs. high-fat diets. While glycogen accumulation in the liver is reduced in IKKεAlb-/- mice, lipid storage in liver is similar in IKKεAlb-/- mice and littermate controls. Our results using IKKεAlb-/- mice suggest that the primary action of this kinase to impact insulin sensitivity during weight gain lies predominantly within extrahepatic tissues.
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Affiliation(s)
- J Jason Collier
- Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Heidi M Batdorf
- Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Tamra M Mendoza
- Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - David H Burk
- Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Thomas M Martin
- Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Jingying Zhang
- Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | | | - Susan J Burke
- Pennington Biomedical Research Center, Baton Rouge, Louisiana
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9
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Burke SJ, Batdorf HM, Huang TY, Jackson JW, Jones KA, Martin TM, Rohli KE, Karlstad MD, Sparer TE, Burk DH, Campagna SR, Noland RC, Soto PL, Collier JJ. One week of continuous corticosterone exposure impairs hepatic metabolic flexibility, promotes islet β-cell proliferation, and reduces physical activity in male C57BL/6 J mice. J Steroid Biochem Mol Biol 2019; 195:105468. [PMID: 31536768 PMCID: PMC6939671 DOI: 10.1016/j.jsbmb.2019.105468] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2019] [Revised: 08/28/2019] [Accepted: 09/05/2019] [Indexed: 10/26/2022]
Abstract
Clinical glucocorticoid use, and diseases that produce elevated circulating glucocorticoids, promote drastic changes in body composition and reduction in whole body insulin sensitivity. Because steroid-induced diabetes is the most common form of drug-induced hyperglycemia, we investigated mechanisms underlying the recognized phenotypes associated with glucocorticoid excess. Male C57BL/6 J mice were exposed to either 100ug/mL corticosterone (cort) or vehicle in their drinking water. Body composition measurements revealed an increase in fat mass with drastically reduced lean mass during the first week (i.e., seven days) of cort exposure. Relative to the vehicle control group, mice receiving cort had a significant reduction in insulin sensitivity (measured by insulin tolerance test) five days after drug intervention. The increase in insulin resistance significantly correlated with an increase in the number of Ki-67 positive β-cells. Moreover, the ability to switch between fuel sources in liver tissue homogenate substrate oxidation assays revealed reduced metabolic flexibility. Furthermore, metabolomics analyses revealed a decrease in liver glycolytic metabolites, suggesting reduced glucose utilization, a finding consistent with onset of systemic insulin resistance. Physical activity was reduced, while respiratory quotient was increased, in mice receiving corticosterone. The majority of metabolic changes were reversed upon cessation of the drug regimen. Collectively, we conclude that changes in body composition and tissue level substrate metabolism are key components influencing the reductions in whole body insulin sensitivity observed during glucocorticoid administration.
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Affiliation(s)
- Susan J Burke
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA 70808, United States
| | - Heidi M Batdorf
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA 70808, United States
| | - Tai-Yu Huang
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA 70808, United States
| | - Joseph W Jackson
- Department of Microbiology, University of Tennessee, Knoxville, TN 37996, United States
| | - Katarina A Jones
- Department of Chemistry, University of Tennessee, Knoxville, TN 37996, United States
| | - Thomas M Martin
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA 70808, United States; Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, United States
| | - Kristen E Rohli
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA 70808, United States; Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, United States
| | - Michael D Karlstad
- Department of Surgery, University of Tennessee Health Science Center, Knoxville, TN 37920, United States
| | - Tim E Sparer
- Department of Microbiology, University of Tennessee, Knoxville, TN 37996, United States
| | - David H Burk
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA 70808, United States
| | - Shawn R Campagna
- Department of Chemistry, University of Tennessee, Knoxville, TN 37996, United States
| | - Robert C Noland
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA 70808, United States
| | - Paul L Soto
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA 70808, United States; Department of Psychology, Louisiana State University, Baton Rouge, LA 70803, United States
| | - J Jason Collier
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA 70808, United States; Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, United States.
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Fuller SE, Huang TY, Simon J, Batdorf HM, Essajee NM, Scott MC, Waskom CM, Brown JM, Burke SJ, Collier JJ, Noland RC. Low-intensity exercise induces acute shifts in liver and skeletal muscle substrate metabolism but not chronic adaptations in tissue oxidative capacity. J Appl Physiol (1985) 2019; 127:143-156. [PMID: 31095457 PMCID: PMC6692746 DOI: 10.1152/japplphysiol.00820.2018] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 04/23/2019] [Accepted: 05/08/2019] [Indexed: 02/08/2023] Open
Abstract
Adaptations in hepatic and skeletal muscle substrate metabolism following acute and chronic (6 wk; 5 days/wk; 1 h/day) low-intensity treadmill exercise were tested in healthy male C57BL/6J mice. Low-intensity exercise maximizes lipid utilization; therefore, we hypothesized pathways involved in lipid metabolism would be most robustly affected. Acute exercise nearly depleted liver glycogen immediately postexercise (0 h), whereas hepatic triglyceride (TAG) stores increased in the early stages after exercise (0-3 h). Also, hepatic peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) gene expression and fat oxidation (mitochondrial and peroxisomal) increased immediately postexercise (0 h), whereas carbohydrate and amino acid oxidation in liver peaked 24-48 h later. Alternatively, skeletal muscle exhibited a less robust response to acute exercise as stored substrates (glycogen and TAG) remained unchanged, induction of PGC-1α gene expression was delayed (up at 3 h), and mitochondrial substrate oxidation pathways (carbohydrate, amino acid, and lipid) were largely unaltered. Peroxisomal lipid oxidation exhibited the most dynamic changes in skeletal muscle substrate metabolism after acute exercise; however, this response was also delayed (peaked 3-24 h postexercise), and expression of peroxisomal genes remained unaffected. Interestingly, 6 wk of training at a similar intensity limited weight gain, increased muscle glycogen, and reduced TAG accrual in liver and muscle; however, substrate oxidation pathways remained unaltered in both tissues. Collectively, these results suggest changes in substrate metabolism induced by an acute low-intensity exercise bout in healthy mice are more rapid and robust in liver than in skeletal muscle; however, training at a similar intensity for 6 wk is insufficient to induce remodeling of substrate metabolism pathways in either tissue. NEW & NOTEWORTHY Effects of low-intensity exercise on substrate metabolism pathways were tested in liver and skeletal muscle of healthy mice. This is the first study to describe exercise-induced adaptations in peroxisomal lipid metabolism and also reports comprehensive adaptations in mitochondrial substrate metabolism pathways (carbohydrate, lipid, and amino acid). Acute low-intensity exercise induced shifts in mitochondrial and peroxisomal metabolism in both tissues, but training at this intensity did not induce adaptive remodeling of metabolic pathways in healthy mice.
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Affiliation(s)
- Scott E Fuller
- Skeletal Muscle Metabolism Laboratory, Pennington Biomedical Research Center , Baton Rouge, Louisiana
- School of Kinesiology, University of Louisiana at Lafayette , Lafayette, Louisiana
| | - Tai-Yu Huang
- Skeletal Muscle Metabolism Laboratory, Pennington Biomedical Research Center , Baton Rouge, Louisiana
| | - Jacob Simon
- Skeletal Muscle Metabolism Laboratory, Pennington Biomedical Research Center , Baton Rouge, Louisiana
| | - Heidi M Batdorf
- Skeletal Muscle Metabolism Laboratory, Pennington Biomedical Research Center , Baton Rouge, Louisiana
- Laboratory of Immunogenetics, Pennington Biomedical Research Center , Baton Rouge, Louisiana
- Laboratory of Islet Biology and Inflammation, Pennington Biomedical Research Center , Baton Rouge, Louisiana
| | - Nabil M Essajee
- Skeletal Muscle Metabolism Laboratory, Pennington Biomedical Research Center , Baton Rouge, Louisiana
| | - Matthew C Scott
- Skeletal Muscle Metabolism Laboratory, Pennington Biomedical Research Center , Baton Rouge, Louisiana
| | - Callie M Waskom
- Skeletal Muscle Metabolism Laboratory, Pennington Biomedical Research Center , Baton Rouge, Louisiana
| | - John M Brown
- Skeletal Muscle Metabolism Laboratory, Pennington Biomedical Research Center , Baton Rouge, Louisiana
| | - Susan J Burke
- Laboratory of Immunogenetics, Pennington Biomedical Research Center , Baton Rouge, Louisiana
| | - J Jason Collier
- Laboratory of Islet Biology and Inflammation, Pennington Biomedical Research Center , Baton Rouge, Louisiana
| | - Robert C Noland
- Skeletal Muscle Metabolism Laboratory, Pennington Biomedical Research Center , Baton Rouge, Louisiana
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Burke SJ, Batdorf HM, Martin TM, Burk DH, Noland RC, Cooley CR, Karlstad MD, Johnson WD, Collier JJ. Liquid Sucrose Consumption Promotes Obesity and Impairs Glucose Tolerance Without Altering Circulating Insulin Levels. Obesity (Silver Spring) 2018; 26:1188-1196. [PMID: 29901267 PMCID: PMC6014929 DOI: 10.1002/oby.22217] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2018] [Revised: 04/26/2018] [Accepted: 04/28/2018] [Indexed: 12/13/2022]
Abstract
OBJECTIVE Multiple factors contribute to the rising rates of obesity and to difficulties in weight reduction that exist in the worldwide population. Caloric intake via sugar-sweetened beverages may be influential. This study tested the hypothesis that liquid sucrose intake promotes obesity by increasing serum insulin levels and tissue lipid accumulation. METHODS C57BL/6J mice were given 30% sucrose in liquid form. Changes in weight gain, body composition, energy expenditure (EE), and tissue lipid content were measured. RESULTS Mice drinking sucrose gained more total body mass (TBM), had greater fat mass, and displayed impaired glucose tolerance relative to control mice. These metabolic changes occurred without alterations in circulating insulin levels and despite increases in whole body EE. Lipid accrued in liver, but not skeletal muscle, of sucrose-consuming mice. Oxygen consumption (VO2 ) correlated with fat-free mass and moderately with TBM, but not with fat mass. ANCOVA for treatment effects on EE, with TBM, VO2 , lean body mass, and fat-free mass taken as potential covariates for EE, revealed VO2 as the most significant correlation. CONCLUSIONS Weight gain induced by intake of liquid sucrose in mice is associated with lipid accrual in liver, but not skeletal muscle, and occurs without an increase in circulating insulin.
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Affiliation(s)
| | | | | | - David H. Burk
- Pennington Biomedical Research Center, Baton Rouge, LA
| | | | - Christopher R. Cooley
- Department of Surgery, Graduate School of Medicine, University of Tennessee Health Science Center, Knoxville, TN
| | - Michael D. Karlstad
- Department of Surgery, Graduate School of Medicine, University of Tennessee Health Science Center, Knoxville, TN
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12
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Burke SJ, Batdorf HM, Burk DH, Martin TM, Mendoza T, Stadler K, Alami W, Karlstad MD, Robson MJ, Blakely RD, Mynatt RL, Collier JJ. Pancreatic deletion of the interleukin-1 receptor disrupts whole body glucose homeostasis and promotes islet β-cell de-differentiation. Mol Metab 2018; 14:95-107. [PMID: 29914854 PMCID: PMC6034063 DOI: 10.1016/j.molmet.2018.06.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2018] [Revised: 05/30/2018] [Accepted: 06/02/2018] [Indexed: 02/06/2023] Open
Abstract
Objective Pancreatic tissue, and islets in particular, are enriched in expression of the interleukin-1 receptor type I (IL-1R). Because of this enrichment, islet β-cells are exquisitely sensitive to the IL-1R ligands IL-1α and IL-1β, suggesting that signaling through this pathway regulates health and function of islet β-cells. Methods Herein, we report a targeted deletion of IL-1R in pancreatic tissue (IL-1RPdx1−/−) in C57BL/6J mice and in db/db mice on the C57 genetic background. Islet morphology, β-cell transcription factor abundance, and expression of the de-differentiation marker Aldh1a3 were analyzed by immunofluorescent staining. Glucose and insulin tolerance tests were used to examine metabolic status of these genetic manipulations. Glucose-stimulated insulin secretion was evaluated in vivo and in isolated islets ex vivo by perifusion. Results Pancreatic deletion of IL-1R leads to impaired glucose tolerance, a phenotype that is exacerbated by age. Crossing the IL-1RPdx1−/− with db/db mice worsened glucose tolerance without altering body weight. There were no detectable alterations in insulin tolerance between IL-1RPdx1−/− mice and littermate controls. However, glucose-stimulated insulin secretion was reduced in islets isolated from IL-1RPdx1−/− relative to control islets. Insulin output in vivo after a glucose challenge was also markedly reduced in IL-1RPdx1−/− mice when compared with littermate controls. Pancreatic islets from IL-1RPdx1−/− mice displayed elevations in Aldh1a3, a marker of de-differentiation, and reduction in nuclear abundance of the β-cell transcription factor MafA. Nkx6.1 abundance was unaltered. Conclusions There is an important physiological role for pancreatic IL-1R to promote glucose homeostasis by suppressing expression of Aldh1a3, sustaining MafA abundance, and supporting glucose-stimulated insulin secretion in vivo. Pancreatic deletion of IL-1R impairs glucose tolerance in young and old male mice. Pancreatic deletion of IL-1R worsens glucose tolerance in obese db/db mice. Deletion of IL-1R triggers expression of the de-differentiation marker Aldh1a3. IL-1 signaling in pancreatic tissue influences islet health and function.
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Affiliation(s)
- Susan J Burke
- Pennington Biomedical Research Center, Baton Rouge, LA, 70808, USA
| | - Heidi M Batdorf
- Pennington Biomedical Research Center, Baton Rouge, LA, 70808, USA
| | - David H Burk
- Pennington Biomedical Research Center, Baton Rouge, LA, 70808, USA
| | - Thomas M Martin
- Pennington Biomedical Research Center, Baton Rouge, LA, 70808, USA
| | - Tamra Mendoza
- Pennington Biomedical Research Center, Baton Rouge, LA, 70808, USA
| | | | - Wateen Alami
- Department of Surgery, University of Tennessee Health Science Center, Knoxville, TN, 37920, USA
| | - Michael D Karlstad
- Department of Surgery, University of Tennessee Health Science Center, Knoxville, TN, 37920, USA
| | - Matthew J Robson
- Division of Pharmaceutical Sciences, James L. Winkle College of Pharmacy, University of Cincinnati, Cincinnati, OH, 45267, USA
| | - Randy D Blakely
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Jupiter FL, 33458, USA
| | - Randall L Mynatt
- Pennington Biomedical Research Center, Baton Rouge, LA, 70808, USA
| | - J Jason Collier
- Pennington Biomedical Research Center, Baton Rouge, LA, 70808, USA.
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13
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Burke SJ, Batdorf HM, Martin TM, Burk DH, Noland RC, Johnson WD, Cooley CR, Karlstad MD, Collier JJ. Liquid Sucrose Consumption Promotes Liver Lipid Accumulation, Fat Mass, and Glucose Intolerance without Altering Circulating Insulin Levels. FASEB J 2018. [DOI: 10.1096/fasebj.2018.32.1_supplement.41.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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14
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Burke SJ, Batdorf HM, Burk DH, Noland RC, Eder AE, Boulos MS, Karlstad MD, Collier JJ. db/ db Mice Exhibit Features of Human Type 2 Diabetes That Are Not Present in Weight-Matched C57BL/6J Mice Fed a Western Diet. J Diabetes Res 2017; 2017:8503754. [PMID: 29038790 PMCID: PMC5606106 DOI: 10.1155/2017/8503754] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 07/24/2017] [Accepted: 07/25/2017] [Indexed: 12/19/2022] Open
Abstract
To understand features of human obesity and type 2 diabetes mellitus (T2D) that can be recapitulated in the mouse, we compared C57BL/6J mice fed a Western-style diet (WD) to weight-matched genetically obese leptin receptor-deficient mice (db/db). All mice were monitored for changes in body composition, glycemia, and total body mass. To objectively compare diet-induced and genetic models of obesity, tissue analyses were conducted using mice with similar body mass. We found that adipose tissue inflammation was present in both models of obesity. In addition, distinct alterations in metabolic flexibility were evident between WD-fed mice and db/db mice. Circulating insulin levels are elevated in each model of obesity, while glucagon was increased only in the db/db mice. Although both WD-fed and db/db mice exhibited adaptive increases in islet size, the db/db mice also displayed augmented islet expression of the dedifferentiation marker Aldh1a3 and reduced nuclear presence of the transcription factor Nkx6.1. Based on the collective results put forth herein, we conclude that db/db mice capture key features of human T2D that do not occur in WD-fed C57BL/6J mice of comparable body mass.
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Affiliation(s)
- Susan J. Burke
- Laboratory of Immunogenetics, Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA
| | - Heidi M. Batdorf
- Laboratory of Islet Biology and Inflammation, Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA
- Skeletal Muscle Metabolism Laboratory, Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA
| | - David H. Burk
- Cell Biology and Bioimaging Core Facility, Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA
| | - Robert C. Noland
- Skeletal Muscle Metabolism Laboratory, Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA
| | - Adrianna E. Eder
- Department of Surgery, Graduate School of Medicine, University of Tennessee Health Science Center, Knoxville, TN 37920, USA
| | - Matthew S. Boulos
- Department of Surgery, Graduate School of Medicine, University of Tennessee Health Science Center, Knoxville, TN 37920, USA
| | - Michael D. Karlstad
- Department of Surgery, Graduate School of Medicine, University of Tennessee Health Science Center, Knoxville, TN 37920, USA
| | - J. Jason Collier
- Laboratory of Islet Biology and Inflammation, Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA
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