51
|
Hong Y, Lin Y, Si Q, Yang L, Dong W, Gu X. Ginsenoside Rb2 Alleviates Obesity by Activation of Brown Fat and Induction of Browning of White Fat. Front Endocrinol (Lausanne) 2019; 10:153. [PMID: 30930854 PMCID: PMC6428988 DOI: 10.3389/fendo.2019.00153] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 02/21/2019] [Indexed: 12/18/2022] Open
Abstract
Ginsenoside Rb2 (Rb2), the most abundant saponin contained in Panax ginseng, has been used to treat variety of metabolic diseases. However, its effects in obesity and potential mechanisms are not well-understood. In the present study, we investigated metabolic performance with a Rb2 supplement in diet-induced obese (DIO) mice, focusing on the effects and mechanisms of Rb2 on brown and beige fat functions. Our results demonstrated that Rb2 effectively reduced body weight, improved insulin sensitivity, as well as induced energy expenditure in DIO mice. Histological and gene analysis revealed that Rb2 induced activation of brown fat and browning of white fat by reducing lipid droplets, stimulating uncoupling protein 1 (UCP1) staining, and increasing expression of thermogenic and mitochondrial genes, which could be recapitulated in 3T3-L1, C3H10T1/2, and primary adipocytes. In addition, Rb2 induced phosphorylation of AMP-activated protein kinase (AMPK) both in vitro and in vivo. These effects were shown to be dependent on AMPK since its inhibitor blocked Rb2 from inducing expressions of Pgc1α and Ucp1. Overall, the present study revealed that Rb2 activated brown fat and induced browning of white fat, which increased energy expenditure and thermogenesis, and consequently ameliorated obesity and metabolic disorders. These suggest that Rb2 holds promise in treating obesity.
Collapse
Affiliation(s)
- Yilian Hong
- Department of Endocrine and Metabolic Diseases, First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Yi Lin
- Department of Endocrine and Metabolic Diseases, First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Qiya Si
- Department of Endocrine and Metabolic Diseases, First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Lijuan Yang
- Department of Endocrine and Metabolic Diseases, First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Weisong Dong
- Department of Pathology, First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Xuejiang Gu
- Department of Endocrine and Metabolic Diseases, First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
- *Correspondence: Xuejiang Gu
| |
Collapse
|
52
|
Hang W, He B, Chen J, Xia L, Wen B, Liang T, Wang X, Zhang Q, Wu Y, Chen Q, Chen J. Berberine Ameliorates High Glucose-Induced Cardiomyocyte Injury via AMPK Signaling Activation to Stimulate Mitochondrial Biogenesis and Restore Autophagic Flux. Front Pharmacol 2018; 9:1121. [PMID: 30337876 PMCID: PMC6178920 DOI: 10.3389/fphar.2018.01121] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 09/13/2018] [Indexed: 12/29/2022] Open
Abstract
Background: Type II diabetes (T2D)-induced cardiomyocyte hypertrophy is closely linked to the impairment of mitochondrial function. Berberine has been shown to be a promising effect for hypoglycemia in T2D models. High glucose-induced cardiomyocyte hypertrophy in vitro has been reported. The present study investigated the protective effect and the underlying mechanism of berberine on high glucose-induced H9C2 cell line. Methods: High glucose-induced H9C2 cell line was used to mimic the hyperglycemia resulting in cardiomyocyte hypertrophy. Berberine was used to rescue in this model and explore the mechanism in it. Confocal microscopy, immunofluorescence, RT-PCR, and western blot analysis were performed to evaluate the protective effects of berberine in high glucose-induced H9C2 cell line. Results: Berberine dramatically alleviated hypertrophy of H9C2 cell line and significantly ameliorated mitochondrial function by rectifying the imbalance of fusion and fission in mitochondrial dynamics. Furthermore, berberine further promoted mitogenesis and cleared the damaged mitochondria via mitophagy. In addition, berberine also restored autophagic flux in high glucose-induced cardiomyocyte injury via AMPK signaling pathway activation. Conclusion: Berberine ameliorates high glucose-induced cardiomyocyte injury via AMPK signaling pathway activation to stimulate mitochondrial biogenesis and restore autophagicflux in H9C2 cell line.
Collapse
Affiliation(s)
- Weijian Hang
- Department of Biochemistry and Molecular Biology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan, China
| | - Benhong He
- Department of Cardiovascular Medicine, Lichuan People's Hospital, Lichuan, China
| | - Jiehui Chen
- Department of Biochemistry and Molecular Biology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Liangtao Xia
- Department of Biochemistry and Molecular Biology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Bing Wen
- Department of Biochemistry and Molecular Biology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Tao Liang
- Department of Biochemistry and Molecular Biology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xu Wang
- Department of Biochemistry and Molecular Biology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Qianying Zhang
- Department of Biochemistry and Molecular Biology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yue Wu
- Department of Biochemistry and Molecular Biology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Qingjie Chen
- Department of Biochemistry and Molecular Biology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,New Products of TCM Senile Diseases Co-Innovation Center of Hubei, School of Basic Medicine, Hubei University of Chinese Medicine, Wuhan, China
| | - Juan Chen
- Department of Biochemistry and Molecular Biology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Institute for Brain Research, Huazhong University of Science and Technology, Wuhan, China.,Key Laboratory of Neurological Disease of National Education Ministry, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| |
Collapse
|
53
|
Booth A, Magnuson A, Fouts J, Wei Y, Wang D, Pagliassotti M, Foster M. Subcutaneous adipose tissue accumulation protects systemic glucose tolerance and muscle metabolism. Adipocyte 2018; 7:261-272. [PMID: 30230416 PMCID: PMC6768251 DOI: 10.1080/21623945.2018.1525252] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The protective effects of lower body subcutaneous adiposity are linked to the depot functioning as a "metabolic sink" receiving and sequestering excess lipid. This postulate, however, is based on indirect evidence. Mechanisms that mediate this protection are unknown. Here we directly examined this with progressive subcutaneous adipose tissue removal. Ad libitum chow fed mice underwent sham surgery, unilateral or bilateral removal of inguinal adipose tissue or bilateral removal of both inguinal and dorsal adipose tissue. Subsequently mice were separated into 5 week chow or 5 or 13 week HFD groups (N = 10 per group). Primary outcome measures included adipocyte distribution, muscle and liver triglycerides, glucose tolerance, circulating adipocytokines and muscle insulin sensitivity. Subcutaneous adipose tissue removal caused lipid accumulation in femoral muscle proximal to excision, however, lipid accumulation was not proportionally inverse to adipose tissue quantity excised. Accumulative adipose removal was associated with an incremental reduction in systemic glucose tolerance in 13 week HFD mice. Although insulin-stimulated pAkt/Akt did not progressively decrease among surgery groups following 13 weeks of HFD, there was a suppressed pAkt/Akt response in the non-insulin stimulated (saline-injected) 13 week HFD mice. Hence, increases in lower body subcutaneous adipose removal resulted in incremental decreases in the effectiveness of basal insulin sensitivity of femoral muscle. The current data supports that the subcutaneous depot protects systemic glucose homeostasis while also protecting proximal muscle from metabolic dysregulation and lipid accumulation. Removal of the "metabolic sink" likely leads to glucose intolerance because of decreased storage space for glucose and/or lipids.
Collapse
Affiliation(s)
- A.D. Booth
- Department of Food Science and Human Nutrition, Colorado State University, Fort Collins, CO, USA
| | - A.M. Magnuson
- Department of Food Science and Human Nutrition, Colorado State University, Fort Collins, CO, USA
| | - J. Fouts
- Department of Food Science and Human Nutrition, Colorado State University, Fort Collins, CO, USA
| | - Y. Wei
- Department of Food Science and Human Nutrition, Colorado State University, Fort Collins, CO, USA
| | - D. Wang
- Department of Food Science and Human Nutrition, Colorado State University, Fort Collins, CO, USA
| | - M.J. Pagliassotti
- Department of Food Science and Human Nutrition, Colorado State University, Fort Collins, CO, USA
| | - M.T. Foster
- Department of Food Science and Human Nutrition, Colorado State University, Fort Collins, CO, USA
| |
Collapse
|
54
|
Foretz M, Even PC, Viollet B. AMPK Activation Reduces Hepatic Lipid Content by Increasing Fat Oxidation In Vivo. Int J Mol Sci 2018; 19:ijms19092826. [PMID: 30235785 PMCID: PMC6164956 DOI: 10.3390/ijms19092826] [Citation(s) in RCA: 89] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 09/13/2018] [Accepted: 09/15/2018] [Indexed: 02/08/2023] Open
Abstract
The energy sensor AMP-activated protein kinase (AMPK) is a key player in the control of energy metabolism. AMPK regulates hepatic lipid metabolism through the phosphorylation of its well-recognized downstream target acetyl CoA carboxylase (ACC). Although AMPK activation is proposed to lower hepatic triglyceride (TG) content via the inhibition of ACC to cause inhibition of de novo lipogenesis and stimulation of fatty acid oxidation (FAO), its contribution to the inhibition of FAO in vivo has been recently questioned. We generated a mouse model of AMPK activation specifically in the liver, achieved by expression of a constitutively active AMPK using adenoviral delivery. Indirect calorimetry studies revealed that liver-specific AMPK activation is sufficient to induce a reduction in the respiratory exchange ratio and an increase in FAO rates in vivo. This led to a more rapid metabolic switch from carbohydrate to lipid oxidation during the transition from fed to fasting. Finally, mice with chronic AMPK activation in the liver display high fat oxidation capacity evidenced by increased [C14]-palmitate oxidation and ketone body production leading to reduced hepatic TG content and body adiposity. Our findings suggest a role for hepatic AMPK in the remodeling of lipid metabolism between the liver and adipose tissue.
Collapse
Affiliation(s)
- Marc Foretz
- INSERM, U1016, Institut Cochin, Département d'Endocrinologie Métabolisme et Diabète, 24, rue du Faubourg Saint Jacques, 75014 Paris, France.
- CNRS, UMR8104, 75014 Paris, France.
- Université Paris Descartes, Sorbonne Paris Cité, 75014 Paris, France.
| | - Patrick C Even
- UMR PNCA, AgroParisTech, INRA, Université Paris-Saclay, 75005 Paris, France.
| | - Benoit Viollet
- INSERM, U1016, Institut Cochin, Département d'Endocrinologie Métabolisme et Diabète, 24, rue du Faubourg Saint Jacques, 75014 Paris, France.
- CNRS, UMR8104, 75014 Paris, France.
- Université Paris Descartes, Sorbonne Paris Cité, 75014 Paris, France.
| |
Collapse
|
55
|
|
56
|
Lee MS, Han HJ, Han SY, Kim IY, Chae S, Lee CS, Kim SE, Yoon SG, Park JW, Kim JH, Shin S, Jeong M, Ko A, Lee HY, Oh KJ, Lee YH, Bae KH, Koo SH, Kim JW, Seong JK, Hwang D, Song J. Loss of the E3 ubiquitin ligase MKRN1 represses diet-induced metabolic syndrome through AMPK activation. Nat Commun 2018; 9:3404. [PMID: 30143610 PMCID: PMC6109074 DOI: 10.1038/s41467-018-05721-4] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 07/19/2018] [Indexed: 01/05/2023] Open
Abstract
AMP-activated protein kinase (AMPK) plays a key role in controlling energy metabolism in response to physiological and nutritional status. Although AMPK activation has been proposed as a promising molecular target for treating obesity and its related comorbidities, the use of pharmacological AMPK activators has been met with contradictory therapeutic challenges. Here we show a regulatory mechanism for AMPK through its ubiquitination and degradation by the E3 ubiquitin ligase makorin ring finger protein 1 (MKRN1). MKRN1 depletion promotes glucose consumption and suppresses lipid accumulation due to AMPK stabilisation and activation. Accordingly, MKRN1-null mice show chronic AMPK activation in both liver and adipose tissue, resulting in significant suppression of diet-induced metabolic syndrome. We demonstrate also its therapeutic effect by administering shRNA targeting MKRN1 into obese mice that reverses non-alcoholic fatty liver disease. We suggest that ubiquitin-dependent AMPK degradation represents a target therapeutic strategy for metabolic disorders. AMPK activation has been suggested as treatment for obesity and its complications. Here the authors show that the ubiquitin ligase MKRN1 binds to AMPK and mediates its ubiquitination and degradation. Loss of MKRN1 leads to AMPK activation, increased glucose consumption and decreased lipid accumulation.
Collapse
Affiliation(s)
- Min-Sik Lee
- Harvard Medical School, Boston Children's Hospital, 3 Blackfan Circle CLS-16060.2, Boston, MA, 02115, USA
| | - Hyun-Ji Han
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul, 03722, Republic of Korea
| | - Su Yeon Han
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul, 03722, Republic of Korea
| | - Il Young Kim
- Laboratory of Developmental Biology and Genomics, Research Institute for Veterinary Science and BK21 Program for Creative Veterinary Science and Research, College of Veterinary Medicine, Seoul National University, Seoul, 08826, Republic of Korea.,Korea Mouse Phenotyping Center (KMPC), Seoul National University, Seoul, 08826, Republic of Korea
| | - Sehyun Chae
- Center for Plant Aging Research, Institute for Basic Science, and Department of New Biology, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, Republic of Korea
| | - Choong-Sil Lee
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul, 03722, Republic of Korea
| | - Sung Eun Kim
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul, 03722, Republic of Korea
| | - Seul Gi Yoon
- Korea Mouse Phenotyping Center (KMPC), Seoul National University, Seoul, 08826, Republic of Korea
| | - Jun-Won Park
- Korea Mouse Phenotyping Center (KMPC), Seoul National University, Seoul, 08826, Republic of Korea
| | - Jung-Hoon Kim
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul, 03722, Republic of Korea
| | - Soyeon Shin
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul, 03722, Republic of Korea
| | - Manhyung Jeong
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul, 03722, Republic of Korea
| | - Aram Ko
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul, 03722, Republic of Korea
| | - Ho-Young Lee
- Department of Nuclear Medicine, Seoul National University Bundang Hospital, Seongnam, 13620, Republic of Korea
| | - Kyoung-Jin Oh
- Metabolic Regulation Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, 34141, Republic of Korea
| | - Yun-Hee Lee
- College of Pharmacy, Yonsei Institute of Pharmaceutical Sciences, Yonsei University, Incheon, 21983, Republic of Korea
| | - Kwang-Hee Bae
- Metabolic Regulation Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, 34141, Republic of Korea
| | - Seung-Hoi Koo
- Division of Life Sciences, College of Life Sciences & Biotechnology, Korea University, Seoul, 02841, Republic of Korea
| | - Jea-Woo Kim
- Department of Biochemistry and Molecular Biology, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, 03722, Republic of Korea
| | - Je Kyung Seong
- Laboratory of Developmental Biology and Genomics, Research Institute for Veterinary Science and BK21 Program for Creative Veterinary Science and Research, College of Veterinary Medicine, Seoul National University, Seoul, 08826, Republic of Korea.,Korea Mouse Phenotyping Center (KMPC), Seoul National University, Seoul, 08826, Republic of Korea
| | - Daehee Hwang
- Center for Plant Aging Research, Institute for Basic Science, and Department of New Biology, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, Republic of Korea
| | - Jaewhan Song
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul, 03722, Republic of Korea.
| |
Collapse
|
57
|
Parra-Vargas M, Sandoval-Rodriguez A, Rodriguez-Echevarria R, Dominguez-Rosales JA, Santos-Garcia A, Armendariz-Borunda J. Delphinidin Ameliorates Hepatic Triglyceride Accumulation in Human HepG2 Cells, but Not in Diet-Induced Obese Mice. Nutrients 2018; 10:E1060. [PMID: 30103390 PMCID: PMC6115893 DOI: 10.3390/nu10081060] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 08/06/2018] [Accepted: 08/08/2018] [Indexed: 02/06/2023] Open
Abstract
Anthocyanin consumption is linked to benefits in obesity-related metabolic alterations and non-alcoholic fatty liver disease (NAFLD), though the functional role of delphinidin (Dp) is yet to be established. Therefore, this study examined the effects of Dp on metabolic alterations associated with NAFLD, and molecular mechanisms in HepG2 cells and diet-induced obese mice. Cells incubated with palmitate to induce lipid accumulation, concomitantly treated with Dp, reduced triglyceride accumulation by ~53%, and downregulated gene expression of CPT1A, SREBF1, and FASN without modifying AMP-activated protein kinase (AMPK) levels. C57BL/6Nhsd mice were fed a standard diet (control) or a high-fat/high-carbohydrate diet (HFHC) for 16 weeks. Mice in the HFHC group were subdivided and treated with Dp (HFHC-Dp, 15 mg/kg body weight/day) or a vehicle for four weeks. Dp did not affect body weight, energy intake, hyperglycemia, insulin resistance, or histological abnormalities elicited by the HFHC diet. Furthermore, the messenger RNA (mRNA) expressions of Acaca, and Fasn in hepatic or epididymal adipose tissue, and the hepatic sirtuin 1 (SIRT1)/liver kinase B1 (LKB1)/AMPK and proliferator-activated receptor alpha (PPARα) signaling axis did not significantly change due to the HFHC diet or Dp. In summary, Dp effectively reduced triglyceride accumulation in vitro through the modulation of lipid metabolic gene expression. However, a dose of Dp administrated in mice simulating the total daily anthocyanin intake in humans had no effect on either metabolic alterations or histological abnormalities associated with HFHC diets.
Collapse
Affiliation(s)
- Marcela Parra-Vargas
- Institute for Molecular Biology in Medicine and Gene Therapy, Department of Molecular Biology and Genomics, CUCS, University of Guadalajara, Guadalajara 44340, Jalisco, Mexico.
| | - Ana Sandoval-Rodriguez
- Institute for Molecular Biology in Medicine and Gene Therapy, Department of Molecular Biology and Genomics, CUCS, University of Guadalajara, Guadalajara 44340, Jalisco, Mexico.
| | - Roberto Rodriguez-Echevarria
- Institute for Molecular Biology in Medicine and Gene Therapy, Department of Molecular Biology and Genomics, CUCS, University of Guadalajara, Guadalajara 44340, Jalisco, Mexico.
| | - Jose Alfredo Dominguez-Rosales
- Chronic-Degenerative Diseases Institute, Department of Molecular Biology and Genomics, CUCS, University of Guadalajara, Guadalajara 44340, Jalisco, Mexico.
| | - Arturo Santos-Garcia
- Tecnologico de Monterrey, Campus Guadalajara, Guadalajara 45138, Jalisco, Mexico.
| | - Juan Armendariz-Borunda
- Institute for Molecular Biology in Medicine and Gene Therapy, Department of Molecular Biology and Genomics, CUCS, University of Guadalajara, Guadalajara 44340, Jalisco, Mexico.
- Tecnologico de Monterrey, Campus Guadalajara, Guadalajara 45138, Jalisco, Mexico.
| |
Collapse
|
58
|
Regulation of Metabolic Disease-Associated Inflammation by Nutrient Sensors. Mediators Inflamm 2018; 2018:8261432. [PMID: 30116154 PMCID: PMC6079375 DOI: 10.1155/2018/8261432] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 05/21/2018] [Accepted: 06/14/2018] [Indexed: 12/15/2022] Open
Abstract
Visceral obesity is frequently associated with the development of type 2 diabetes (T2D), a highly prevalent chronic disease that features insulin resistance and pancreatic β-cell dysfunction as important hallmarks. Recent evidence indicates that the chronic, low-grade inflammation commonly associated with visceral obesity plays a major role connecting the excessive visceral fat deposition with the development of insulin resistance and pancreatic β-cell dysfunction. Herein, we review the mechanisms by which nutrients modulate obesity-associated inflammation.
Collapse
|
59
|
Bussey CT, Thaung HPA, Hughes G, Bahn A, Lamberts RR. Cardiac β-adrenergic responsiveness of obese Zucker rats: The role of AMPK. Exp Physiol 2018; 103:1067-1075. [PMID: 29873129 DOI: 10.1113/ep087054] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 05/30/2018] [Indexed: 01/30/2023]
Abstract
NEW FINDINGS What is the central question of the study? Is the reduced signalling of AMP-activated protein kinase (AMPK), a key regulator of energy homeostasis in the heart, responsible for the reduced β-adrenergic responsiveness of the heart in obesity? What is the main finding and its importance? Inhibition of AMPK in isolated hearts prevented the reduced cardiac β-adrenergic responsiveness of obese rats, which was accompanied by reduced phosphorylation of AMPK, a proxy of AMPK activity. This suggests a direct functional link between β-adrenergic responsiveness and AMPK signalling in the heart, and it suggests that AMPK might be an important target to restore the β-adrenergic responsiveness in the heart in obesity. ABSTRACT The obesity epidemic impacts heavily on cardiovascular health, in part owing to changes in cardiac metabolism. AMP-activated protein kinase (AMPK) is a key regulator of energy homeostasis in the heart and is regulated by β-adrenoceptors (β-ARs) in normal conditions. In obesity, chronic sympathetic overactivation leads to impaired cardiac β-AR responsiveness, although it is unclear whether AMPK signalling, downstream of β-ARs, contributes to this dysfunction. Therefore, we aimed to determine whether reduced AMPK signalling is responsible for the reduced β-AR responsiveness in obesity. In isolated hearts of lean and obese Zucker rats, we tested β-AR responsiveness to the β1 -AR agonist isoprenaline (ISO, 1 × 10-10 to 5 × 10-8 m) in the absence and presence of the AMPK inhibitor, compound C (CC, 10 μm). The β1 -AR expression and AMPK phosphorylation were assessed by Western blot. β-Adrenergic responsiveness was reduced in the hearts of obese rats (logEC50 of ISO-developed pressure dose-response curves: lean -8.53 ± 0.13 × 10x m versus obese -8.35 ± 0.10 × 10x m ; P < 0.05 lean versus obese, n = 6 per group). This difference was not apparent after AMPK inhibition (logEC50 of ISO-developed pressure curves: lean CC -8.19 ± 0.12 × 10x m versus obese CC 8.17 ± 0.13 × 10x m, P < 0.05, n = 6 per group). β1 -Adrenergic receptor expression and AMPK phosphorylation were reduced in hearts of obese rats (AMPK at Thr172 : lean 1.73 ± 0.17 a.u. versus lean CC 0.81 ± 0.13 a.u., and obese 1.18 ± 0.09 a.u. versus obese CC 0.81 ± 0.16 a.u., P < 0.05, n = 6 per group). Thus, a direct functional link between β-adrenergic responsiveness and AMPK signalling in the heart exists, and AMPK might be an important target to restore the reduced cardiac β-adrenergic responsiveness in obesity.
Collapse
Affiliation(s)
- Carol T Bussey
- Department of Physiology - HeartOtago, Otago School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - H P Aye Thaung
- Department of Physiology - HeartOtago, Otago School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Gillian Hughes
- Department of Physiology - HeartOtago, Otago School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Andrew Bahn
- Department of Physiology - HeartOtago, Otago School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Regis R Lamberts
- Department of Physiology - HeartOtago, Otago School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| |
Collapse
|
60
|
Seo YJ, Kim KJ, Choi J, Koh EJ, Lee BY. Spirulina maxima Extract Reduces Obesity through Suppression of Adipogenesis and Activation of Browning in 3T3-L1 Cells and High-Fat Diet-Induced Obese Mice. Nutrients 2018; 10:nu10060712. [PMID: 29865208 PMCID: PMC6024816 DOI: 10.3390/nu10060712] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 05/30/2018] [Accepted: 05/31/2018] [Indexed: 02/08/2023] Open
Abstract
Obesity predisposes animals towards the metabolic syndrome and diseases such as type 2 diabetes, atherosclerosis, and cardiovascular disease. Spirulina maxima is a microalga with anti-oxidant, anti-cancer, and neuroprotective activities, but the anti-obesity effect of Spirulina maxima 70% ethanol extract (SM70EE) has not yet been fully established. We investigated the effect of SM70EE on adipogenesis, lipogenesis, and browning using in vitro and in vivo obesity models. SM70EE treatment reduced lipid droplet accumulation by the oil red O staining method and downregulated the adipogenic proteins C/EBPα, PPARγ, and aP2, and the lipogenic proteins SREBP1, ACC, FAS, LPAATβ, Lipin1, and DGAT1 by western blot analysis. In addition, the index components of SM70EE, chlorophyll a, and C-phycocyanin, reduced adipogenesis and lipogenesis protein levels in 3T3-L1 and C3H10T1/2 cells. High-fat diet (HFD)-fed mice administered with SM70EE demonstrated smaller adipose depots and lower blood lipid concentrations than control HFD-fed mice. The lower body mass gain in treated SM70EE-administrated mice was associated with lower protein expression of adipogenesis factors and higher expression of AMPKα-induced adipose browning proteins PRDM16, PGC1α, and UCP1. SM70EE administration ameliorates obesity, likely by reducing adipogenesis and activating the thermogenic program, in 3T3-L1 cells and HFD-induced obese mice.
Collapse
MESH Headings
- 3T3-L1 Cells
- Adipocytes, Brown/drug effects
- Adipocytes, Brown/metabolism
- Adipocytes, Brown/pathology
- Adipocytes, White/drug effects
- Adipocytes, White/metabolism
- Adipocytes, White/pathology
- Adipogenesis/drug effects
- Adiposity/drug effects
- Animals
- Anti-Obesity Agents/isolation & purification
- Anti-Obesity Agents/pharmacology
- Diet, High-Fat
- Disease Models, Animal
- Dose-Response Relationship, Drug
- Energy Metabolism/drug effects
- Lipid Droplets/drug effects
- Lipid Droplets/metabolism
- Lipid Droplets/pathology
- Lipids/blood
- Lipogenesis/drug effects
- Male
- Mice
- Mice, Inbred ICR
- Obesity/blood
- Obesity/pathology
- Obesity/physiopathology
- Obesity/prevention & control
- Spirulina/chemistry
- Thermogenesis/drug effects
- Time Factors
- Weight Gain/drug effects
Collapse
Affiliation(s)
- Young-Jin Seo
- Department of Food Science and Biotechnology, College of Life Science, CHA University, Seongnam, Kyeonggi 463-400, Korea.
| | - Kui-Jin Kim
- Department of Food Science and Biotechnology, College of Life Science, CHA University, Seongnam, Kyeonggi 463-400, Korea.
| | - Jia Choi
- Department of Food Science and Biotechnology, College of Life Science, CHA University, Seongnam, Kyeonggi 463-400, Korea.
| | - Eun-Jeong Koh
- Department of Food Science and Biotechnology, College of Life Science, CHA University, Seongnam, Kyeonggi 463-400, Korea.
| | - Boo-Yong Lee
- Department of Food Science and Biotechnology, College of Life Science, CHA University, Seongnam, Kyeonggi 463-400, Korea.
| |
Collapse
|
61
|
Molusky MM, Hsieh J, Lee SX, Ramakrishnan R, Tascau L, Haeusler RA, Accili D, Tall AR. Metformin and AMP Kinase Activation Increase Expression of the Sterol Transporters ABCG5/8 (ATP-Binding Cassette Transporter G5/G8) With Potential Antiatherogenic Consequences. Arterioscler Thromb Vasc Biol 2018; 38:1493-1503. [PMID: 29853564 PMCID: PMC6039406 DOI: 10.1161/atvbaha.118.311212] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 05/16/2018] [Indexed: 11/16/2022]
Abstract
OBJECTIVE The mechanisms underlying the cardiovascular benefit of the anti-diabetic drug metformin are poorly understood. Recent studies have suggested metformin may upregulate macrophage reverse cholesterol transport. The final steps of reverse cholesterol transport are mediated by the sterol transporters, ABCG5 (ATP-binding cassette transporter G5) and ABCG8 (ATP-binding cassette transporter G8), which facilitate hepato-biliary transport of cholesterol. This study was undertaken to assess the possibility that metformin induces Abcg5 and Abcg8 expression in liver and to elucidate the underlying mechanisms. APPROACH AND RESULTS Metformin-treated mouse or human primary hepatocytes showed increased expression of Abcg5/8 and the bile salt export pump, Bsep. Administration of metformin to Western-type diet-fed mice showed significant upregulation of Abcg5/8 and Bsep. This resulted in increased initial clearance of 3H-cholesteryl ester HDL (high-density lipoprotein) from plasma. However, fecal 3H-cholesterol output was only marginally increased, possibly reflecting increased hepatic Ldlr (low-density lipoprotein receptor) expression, which would increase nonradiolabeled cholesterol uptake. Abcg5/8 undergo strong circadian variation. Available chromatin immunoprecipitation-Seq data suggested multiple binding sites for Period 2, a transcriptional repressor, within the Abcg5/8 locus. Addition of AMPK (5' adenosine monophosphate-activated protein kinase) agonists decreased Period 2 occupancy, suggesting derepression of Abcg5/8. Inhibition of ATP citrate lyase, which generates acetyl-CoA from citrate, also decreased Period 2 occupancy, with concomitant upregulation of Abcg5/8. This suggests a mechanistic link between feeding-induced acetyl-CoA production and decreased cholesterol excretion via Period 2, resulting in inhibition of Abcg5/8 expression. CONCLUSIONS Our findings provide partial support for the concept that metformin may provide cardiovascular benefit via increased reverse cholesterol transport but also indicate increased Ldlr expression as a potential additional mechanism. AMPK activation or ATP citrate lyase inhibition may mediate antiatherogenic effects through increased ABCG5/8 expression.
Collapse
Affiliation(s)
- Matthew M Molusky
- From the Division of Molecular Medicine, Department of Medicine (M.M.M, J.H., L.T., A.R.T.)
| | - Joanne Hsieh
- From the Division of Molecular Medicine, Department of Medicine (M.M.M, J.H., L.T., A.R.T.)
| | - Samuel X Lee
- Naomi Berrie Diabetes Center, College of Physicians and Surgeons (S.X.L., R.A.H.)
| | | | - Liana Tascau
- From the Division of Molecular Medicine, Department of Medicine (M.M.M, J.H., L.T., A.R.T.)
| | - Rebecca A Haeusler
- Naomi Berrie Diabetes Center, College of Physicians and Surgeons (S.X.L., R.A.H.).,Department of Pathology and Cell Biology (R.A.H.)
| | - Domenico Accili
- Department of Medicine and Naomi Berrie Diabetes Center (D.A.), Columbia University, New York
| | - Alan R Tall
- From the Division of Molecular Medicine, Department of Medicine (M.M.M, J.H., L.T., A.R.T.)
| |
Collapse
|
62
|
Jie X, Li X, Song JQ, Wang D, Wang JH. Anti-inflammatory and autonomic effects of electroacupuncture in a rat model of diet-induced obesity. Acupunct Med 2018; 36:103-109. [PMID: 29487062 DOI: 10.1136/acupmed-2016-011223] [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] [Accepted: 08/20/2017] [Indexed: 02/03/2023]
Abstract
OBJECTIVE To study the effect of electroacupuncture (EA) on the cholinergic anti-inflammatory pathway (CAP) by measurement of vagal activity in rats with high-fat diet (HFD)-induced obesity. METHODS Diet-induced obesity (DIO) was induced in 30 rats by feeding them a HFD for 12 weeks. A further 10 rats fed normal food comprised the lean diet (LD) control group. DIO rats were further subdivided into three groups that received a HFD only (HFD group, n=10), a HFD plus electroacupuncture (HFD+EA group, n=10) or a HFD plus minimal acupuncture (HFD+MA group, n=10). EA and MA treatments were continued for 8 weeks. Heart rate variability (HRV) was used to measure the function of the autonomic nervous system before and after treatment. ELISA was used to determine acetylcholine (ACh) and tumour necrosis factor (TNF)-α levels in the serum. Real-time PCR was used to assess the mRNA expression of α7-subtype nicotinic acetylcholine cholinergic receptors (α7nAChRs) and TNF-α in the mesenteric white adipose tissues (MWAT). RESULTS EA but not MA significantly reduced rats' bodyweight. No difference was found in the low frequency (LF), high frequency (HF) and the balance between LF and HF (LF/HF) components of HRV before treatment. After the EA intervention, HF was elevated and LF/HF was reduced in the HFD+EA group comparedwith the HFD group. TNF-α in the serum and MWAT were increased in the HFD group, but were reduced in the HFD+EA group. Furthermore, EA promoted expression of α7nAChRs and ACh in the MWAT. There was no difference between the HFD and HFD+MA groups for any indices. CONCLUSIONS EA enhanced vagal activity, promoted ACh release and activated α7nAChRs in the MWAT, leading to inhibition of proinflammatory cytokine production.
Collapse
Affiliation(s)
- Xiaoyan Jie
- Department of Neurosurgical Intensive Care Unit, Nanyang Second General Hospital, Nanyang, Henan, China
| | - Xu Li
- Department of Medicine, Nanyang Second General Hospital, Nanyang, Henan, China
| | - Jian-Qing Song
- Department of Neurosurgical Intensive Care Unit, Nanyang Second General Hospital, Nanyang, Henan, China
| | - Dan Wang
- Department of Neurosurgical Intensive Care Unit, Nanyang Second General Hospital, Nanyang, Henan, China
| | - Jian-Hua Wang
- Department of Neurosurgical Intensive Care Unit, Nanyang Second General Hospital, Nanyang, Henan, China
| |
Collapse
|
63
|
Galic S, Loh K, Murray-Segal L, Steinberg GR, Andrews ZB, Kemp BE. AMPK signaling to acetyl-CoA carboxylase is required for fasting- and cold-induced appetite but not thermogenesis. eLife 2018; 7:32656. [PMID: 29433631 PMCID: PMC5811211 DOI: 10.7554/elife.32656] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 01/26/2018] [Indexed: 12/27/2022] Open
Abstract
AMP-activated protein kinase (AMPK) is a known regulator of whole-body energy homeostasis, but the downstream AMPK substrates mediating these effects are not entirely clear. AMPK inhibits fatty acid synthesis and promotes fatty acid oxidation by phosphorylation of acetyl-CoA carboxylase (ACC) 1 at Ser79 and ACC2 at Ser212. Using mice with Ser79Ala/Ser212Ala knock-in mutations (ACC DKI) we find that inhibition of ACC phosphorylation leads to reduced appetite in response to fasting or cold exposure. At sub-thermoneutral temperatures, ACC DKI mice maintain normal energy expenditure and thermogenesis, but fail to increase appetite and lose weight. We demonstrate that the ACC DKI phenotype can be mimicked in wild type mice using a ghrelin receptor antagonist and that ACC DKI mice have impaired orexigenic responses to ghrelin, indicating ACC DKI mice have a ghrelin signaling defect. These data suggest that therapeutic strategies aimed at inhibiting ACC phosphorylation may suppress appetite following metabolic stress.
Collapse
Affiliation(s)
- Sandra Galic
- Department of Medicine, University of Melbourne, Fitzroy, Australia.,St. Vincent's Institute of Medical Research, Melbourne, Australia
| | - Kim Loh
- Department of Medicine, University of Melbourne, Fitzroy, Australia.,St. Vincent's Institute of Medical Research, Melbourne, Australia
| | - Lisa Murray-Segal
- Department of Medicine, University of Melbourne, Fitzroy, Australia.,St. Vincent's Institute of Medical Research, Melbourne, Australia
| | - Gregory R Steinberg
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, Hamilton, Canada.,Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Canada
| | - Zane B Andrews
- Biomedicine Discovery Institute, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Australia.,Department of Physiology, Monash University, Clayton, Australia.,Monash Biomedicine Discovery Institute, Monash University, Clayton, Australia
| | - Bruce E Kemp
- Department of Medicine, University of Melbourne, Fitzroy, Australia.,St. Vincent's Institute of Medical Research, Melbourne, Australia.,Mary MacKillop Institute for Health Research, Australian Catholic University, Fitzroy, Australia
| |
Collapse
|
64
|
Mentoor I, Engelbrecht AM, van Jaarsveld PJ, Nell T. Chemoresistance: Intricate Interplay Between Breast Tumor Cells and Adipocytes in the Tumor Microenvironment. Front Endocrinol (Lausanne) 2018; 9:758. [PMID: 30619088 PMCID: PMC6297254 DOI: 10.3389/fendo.2018.00758] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 11/29/2018] [Indexed: 12/24/2022] Open
Abstract
Excess adipose tissue is a hallmark of an overweight and/or obese state as well as a primary risk factor for breast cancer development and progression. In an overweight/obese state adipose tissue becomes dysfunctional due to rapid hypertrophy, hyperplasia, and immune cell infiltration which is associated with sustained low-grade inflammation originating from dysfunctional adipokine synthesis. Evidence also supports the role of excess adipose tissue (overweight/obesity) as a casual factor for the development of chemotherapeutic drug resistance. Obesity-mediated effects/modifications may contribute to chemotherapeutic drug resistance by altering drug pharmacokinetics, inducing chronic inflammation, as well as altering tumor-associated adipocyte adipokine secretion. Adipocytes in the breast tumor microenvironment enhance breast tumor cell survival and decrease the efficacy of chemotherapeutic agents, resulting in chemotherapeutic resistance. A well-know chemotherapeutic agent, doxorubicin, has shown to negatively impact adipose tissue homeostasis, affecting adipose tissue/adipocyte functionality and storage. Here, it is implied that doxorubicin disrupts adipose tissue homeostasis affecting the functionality of adipose tissue/adipocytes. Although evidence on the effects of doxorubicin on adipose tissue/adipocytes under obesogenic conditions are lacking, this narrative review explores the potential role of obesity in breast cancer progression and treatment resistance with inflammation as an underlying mechanism.
Collapse
Affiliation(s)
- Ilze Mentoor
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, South Africa
| | - Anna-Mart Engelbrecht
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, South Africa
| | - Paul J. van Jaarsveld
- Non-Communicable Diseases Research Unit, South African Medical Research Council, Cape Town, South Africa
- Division of Medical Physiology, Faculty of Medicine and Health Sciences, Stellenbosch University, Stellenbosch, South Africa
| | - Theo Nell
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, South Africa
- *Correspondence: Theo Nell
| |
Collapse
|
65
|
Wong TY, Tan YQ, Lin SM, Leung LK. Apigenin and luteolin display differential hypocholesterolemic mechanisms in mice fed a high-fat diet. Biomed Pharmacother 2017; 96:1000-1007. [DOI: 10.1016/j.biopha.2017.11.131] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 11/16/2017] [Accepted: 11/27/2017] [Indexed: 12/21/2022] Open
|
66
|
Park YM, Padilla J, Kanaley JA, Zidon TM, Welly RJ, Britton SL, Koch LG, Thyfault JP, Booth FW, Vieira-Potter VJ. Voluntary Running Attenuates Metabolic Dysfunction in Ovariectomized Low-Fit Rats. Med Sci Sports Exerc 2017; 49:254-264. [PMID: 27669449 DOI: 10.1249/mss.0000000000001101] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
INTRODUCTION Ovariectomy and high-fat diet (HFD) worsen obesity and metabolic dysfunction associated with low aerobic fitness. Exercise training mitigates metabolic abnormalities induced by low aerobic fitness, but whether the protective effect is maintained after ovariectomy and HFD is unknown. PURPOSE This study determined whether, after ovariectomy and HFD, exercise training improves metabolic function in rats bred for low intrinsic aerobic capacity. METHODS Female rats selectively bred for low (LCR) and high (HCR) intrinsic aerobic capacity (n = 30) were ovariectomized, fed HFD, and randomized to either a sedentary (SED) or voluntary wheel running (EX) group. Resting energy expenditure, glucose tolerance, and spontaneous physical activity were determined midway through the experiment, whereas body weight, wheel running volume, and food intake were assessed throughout the study. Body composition, circulating metabolic markers, and skeletal muscle gene and protein expression were measured at sacrifice. RESULTS EX reduced body weight and adiposity in LCR rats (-10% and -50%, respectively; P < 0.05) and, unexpectedly, increased these variables in HCR rats (+7% and +37%, respectively; P < 0.05) compared with their respective SED controls, likely because of dietary overcompensation. Wheel running volume was approximately fivefold greater in HCR than LCR rats, yet EX enhanced insulin sensitivity equally in LCR and HCR rats (P < 0.05). This EX-mediated improvement in metabolic function was associated with thee gene upregulation of skeletal muscle interleukin-6 and interleukin-10. EX also increased resting energy expenditure, skeletal muscle mitochondrial content (oxidative phosphorylation complexes and citrate synthase activity), and adenosine monophosphate-activated protein kinase activation similarly in both lines (all P <0.05). CONCLUSION Despite a fivefold difference in running volume between rat lines, EX similarly improved systemic insulin sensitivity, resting energy expenditure, and skeletal muscle mitochondrial content and adenosine monophosphate-activated protein kinase activation in ovariectomized LCR and HCR rats fed HFD compared with their respective SED controls.
Collapse
Affiliation(s)
- Young-Min Park
- 1Nutrition and Exercise Physiology, University of Missouri, Columbia, MO; 2Child Health, University of Missouri, Columbia, MO; 3Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO; 4Department of Anesthesiology, University of Michigan Medical School, Ann Arbor, MI; 5Department of Molecular Integrative Physiology, University of Kansas Medical Center, Kansas City, KS; and 6Biomedical Sciences, University of Missouri, Columbia, MO
| | | | | | | | | | | | | | | | | | | |
Collapse
|
67
|
Kasper P, Vohlen C, Dinger K, Mohr J, Hucklenbruch-Rother E, Janoschek R, Köth J, Matthes J, Appel S, Dötsch J, Alejandre Alcazar MA. Renal Metabolic Programming Is Linked to the Dynamic Regulation of a Leptin-Klf15 Axis and Akt/AMPKα Signaling in Male Offspring of Obese Dams. Endocrinology 2017; 158:3399-3415. [PMID: 28938412 DOI: 10.1210/en.2017-00489] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 07/24/2017] [Indexed: 12/27/2022]
Abstract
Childhood obesity is associated with renal diseases. Maternal obesity is a risk factor linked to increased adipocytokines and metabolic disorders in the offspring. Therefore, we studied the impact of maternal obesity on renal-intrinsic insulin and adipocytokine signaling and on renal function and structure. To induce maternal obesity, female mice were fed a high-fat diet (HFD) or a standard diet (SD; control group) prior to mating, during gestation, and throughout lactation. A third group of dams was fed HFD only during lactation (HFD-Lac). After weaning at postnatal day (P)21, offspring of all groups received SD. Clinically, HFD offspring were overweight and insulin resistant at P21. Although no metabolic changes were detected at P70, renal sodium excretion was reduced by 40%, and renal matrix deposition increased in the HFD group. Mechanistically, two stages were differentiated. In the early stage (P21), compared with the control group, HFD showed threefold increased white adipose tissue, impaired glucose tolerance, hyperleptinemia, and hyperinsulinemia. Renal leptin/Stat3-signaling was activated. In contrast, the Akt/ AMPKα cascade and Krüppel-like factor 15 expression were decreased. In the late stage (P70), although no metabolic differences were detected in HFD when compared with the control group, leptin/Stat3-signaling was reduced, and Akt/AMPKα was activated in the kidneys. This effect was linked to an increase of proliferative (cyclinD1/D2) and profibrotic (ctgf/collagen IIIα1) markers, similar to leptin-deficient mice. HFD-Lac mice exhibited metabolic changes at P21 similar to HFD, but no other persistent changes. This study shows a link between maternal obesity and metabolic programming of renal structure and function and intrinsic-renal Stat3/Akt/AMPKα signaling in the offspring.
Collapse
Affiliation(s)
- Philipp Kasper
- Translational Experimental Pediatrics, University Hospital for Pediatrics and Adolescent Medicine, Faculty of Medicine, University of Cologne, 50937 Cologne, Germany
| | - Christina Vohlen
- Translational Experimental Pediatrics, University Hospital for Pediatrics and Adolescent Medicine, Faculty of Medicine, University of Cologne, 50937 Cologne, Germany
- Metabolism and Perinatal Programming, University Hospital for Pediatrics and Adolescent Medicine, Faculty of Medicine, University of Cologne, 50937 Cologne, Germany
| | - Katharina Dinger
- Translational Experimental Pediatrics, University Hospital for Pediatrics and Adolescent Medicine, Faculty of Medicine, University of Cologne, 50937 Cologne, Germany
| | - Jasmine Mohr
- Translational Experimental Pediatrics, University Hospital for Pediatrics and Adolescent Medicine, Faculty of Medicine, University of Cologne, 50937 Cologne, Germany
| | - Eva Hucklenbruch-Rother
- Metabolism and Perinatal Programming, University Hospital for Pediatrics and Adolescent Medicine, Faculty of Medicine, University of Cologne, 50937 Cologne, Germany
| | - Ruth Janoschek
- Metabolism and Perinatal Programming, University Hospital for Pediatrics and Adolescent Medicine, Faculty of Medicine, University of Cologne, 50937 Cologne, Germany
| | - Jessica Köth
- Department of Pharmacology, Faculty of Medicine, University of Cologne, 50937 Cologne, Germany
| | - Jan Matthes
- Department of Pharmacology, Faculty of Medicine, University of Cologne, 50937 Cologne, Germany
| | - Sarah Appel
- University Hospital for Pediatrics and Adolescent Medicine, Faculty of Medicine, University of Cologne, 50937 Cologne, Germany
| | - Jörg Dötsch
- University Hospital for Pediatrics and Adolescent Medicine, Faculty of Medicine, University of Cologne, 50937 Cologne, Germany
| | - Miguel A Alejandre Alcazar
- Translational Experimental Pediatrics, University Hospital for Pediatrics and Adolescent Medicine, Faculty of Medicine, University of Cologne, 50937 Cologne, Germany
- University Hospital for Pediatrics and Adolescent Medicine, Faculty of Medicine, University of Cologne, 50937 Cologne, Germany
| |
Collapse
|
68
|
Park YM, Kanaley JA, Zidon TM, Welly RJ, Scroggins RJ, Britton SL, Koch LG, Thyfault JP, Booth FW, Padilla J, Vieira-Potter VJ. Ovariectomized Highly Fit Rats Are Protected against Diet-Induced Insulin Resistance. Med Sci Sports Exerc 2017; 48:1259-69. [PMID: 26885638 DOI: 10.1249/mss.0000000000000898] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
INTRODUCTION In the absence of exercise training, rats selectively bred for high intrinsic aerobic capacity (high-capacity running (HCR)) are protected against ovariectomy (OVX)-induced insulin resistance (IR) and obesity compared with those bred for low intrinsic aerobic capacity (low-capacity running (LCR)). PURPOSE This study determined whether OVX HCR rats remain protected with exposure to high-fat diet (HFD) compared with OVX LCR rats. METHODS Female HCR and LCR rats (n = 36; age, 27-33 wk) underwent OVX and were randomized to a standard chow diet (NC, 5% kcal fat) or HFD (45% kcal fat) ad libitum for 11 wk. Total energy expenditure, resting energy expenditure, spontaneous physical activity (SPA), and glucose tolerance were assessed midway, whereas fasting circulating metabolic markers, body composition, adipose tissue distribution, and skeletal muscle adenosine monophosphate-activated protein kinase (AMPK), and mitochondrial markers were assessed at sacrifice. RESULTS Both HCR and LCR rats experienced HFD-induced increases in total and visceral adiposity after OVX. Despite similar gains in adiposity, HCR rats were protected from HFD-induced IR and reduced total energy expenditure observed in LCR rats (P < 0.05). This metabolic protection was likely attributed to a compensatory increase in SPA and associated preservation of skeletal muscle AMPK activity in HCR; however, HFD significantly reduced SPA and AMPK activity in LCR (P < 0.05). In both lines, HFD reduced citrate synthase activity, gene expression of markers of mitochondrial biogenesis (tFAM, NRF1, and PGC-1α), and protein levels of mitochondrial oxidative phosphorylation complexes I, II, IV, and V in skeletal muscle (all P < 0.05). CONCLUSION After OVX, HCR and LCR rats differentially respond to HFD such that HCR increase while LCR decrease SPA. This "physical activity compensation" likely confers protection from HFD-induced IR and reduced energy expenditure in HCR rats.
Collapse
Affiliation(s)
- Young-Min Park
- 1Nutrition and Exercise Physiology, University of Missouri, Columbia, MO; 2Department of Anesthesiology, University of Michigan Medical School, Ann Arbor, MI; 3Department of Molecular Integrative Physiology, University of Kansas Medical Center, Kansas City, KS; 4Biomedical Sciences, University of Missouri, Columbia, MO; 5Child Health, University of Missouri, Columbia, MO; 6Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
69
|
Abstract
The AMP-activated protein kinase (AMPK) is a central regulator of multiple metabolic pathways and may have therapeutic importance for treating obesity, insulin resistance, type 2 diabetes (T2D), non-alcoholic fatty liver disease (NAFLD), and cardiovascular disease (CVD). Given the ubiquitous expression of AMPK, it has been a challenge to evaluate which tissue types may be most beneficially poised for mediating the positive metabolic effects of AMPK-centered treatments. In this review we evaluate the metabolic phenotypes of transgenic mouse models in which AMPK expression and function have been manipulated, and the impact this has on controlling lipid metabolism, glucose homeostasis, and inflammation. This information may be useful for guiding the development of AMPK-targeted therapeutics to treat chronic metabolic diseases.
Collapse
Affiliation(s)
- Emily A Day
- Department of Medicine, McMaster University, 1280 Main Street West, Hamilton, ON, Canada
| | - Rebecca J Ford
- Department of Medicine, McMaster University, 1280 Main Street West, Hamilton, ON, Canada
| | - Gregory R Steinberg
- Department of Medicine, McMaster University, 1280 Main Street West, Hamilton, ON, Canada; Department of Biochemistry and Biomedical Sciences, McMaster University, 1280 Main Street West, Hamilton, ON, Canada.
| |
Collapse
|
70
|
Tse MCL, Herlea-Pana O, Brobst D, Yang X, Wood J, Hu X, Liu Z, Lee CW, Zaw AM, Chow BKC, Ye K, Chan CB. Tumor Necrosis Factor-α Promotes Phosphoinositide 3-Kinase Enhancer A and AMP-Activated Protein Kinase Interaction to Suppress Lipid Oxidation in Skeletal Muscle. Diabetes 2017; 66:1858-1870. [PMID: 28404596 PMCID: PMC5482076 DOI: 10.2337/db16-0270] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 03/29/2017] [Indexed: 12/12/2022]
Abstract
Tumor necrosis factor-α (TNF-α) is an inflammatory cytokine that plays a central role in obesity-induced insulin resistance. It also controls cellular lipid metabolism, but the underlining mechanism is poorly understood. We report in this study that phosphoinositide 3-kinase enhancer A (PIKE-A) is a novel effector of TNF-α to facilitate its metabolic modulation in the skeletal muscle. Depletion of PIKE-A in C2C12 myotubes diminished the inhibitory activities of TNF-α on mitochondrial respiration and lipid oxidation, whereas PIKE-A overexpression exacerbated these cellular responses. We also found that TNF-α promoted the interaction between PIKE-A and AMP-activated protein kinase (AMPK) to suppress its kinase activity in vitro and in vivo. As a result, animals with PIKE ablation in the skeletal muscle per se display an upregulation of AMPK phosphorylation and a higher preference to use lipid as the energy production substrate under high-fat diet feeding, which mitigates the development of diet-induced hyperlipidemia, ectopic lipid accumulation, and muscle insulin resistance. Hence, our data reveal PIKE-A as a new signaling factor that is important for TNF-α-initiated metabolic changes in skeletal muscle.
Collapse
Affiliation(s)
- Margaret Chui Ling Tse
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong SAR, People's Republic of China
| | - Oana Herlea-Pana
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK
| | - Daniel Brobst
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK
| | - Xiuying Yang
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK
- Drug Screening Center, Institute of Materia Medica, Beijing, People's Republic of China
| | - John Wood
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK
| | - Xiang Hu
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK
| | - Zhixue Liu
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK
| | - Chi Wai Lee
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong SAR, People's Republic of China
| | - Aung Moe Zaw
- School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, People's Republic of China
| | - Billy K C Chow
- School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, People's Republic of China
| | - Keqiang Ye
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA
| | - Chi Bun Chan
- School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, People's Republic of China
| |
Collapse
|
71
|
Patel MS, Miranda-Nieves D, Chen J, Haller CA, Chaikof EL. Targeting P-selectin glycoprotein ligand-1/P-selectin interactions as a novel therapy for metabolic syndrome. Transl Res 2017; 183:1-13. [PMID: 28034759 PMCID: PMC5393932 DOI: 10.1016/j.trsl.2016.11.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2016] [Accepted: 11/13/2016] [Indexed: 12/22/2022]
Abstract
Obesity-induced insulin resistance and metabolic syndrome continue to pose an important public health challenge worldwide as they significantly increase the risk of type 2 diabetes and atherosclerotic cardiovascular disease. Advances in the pathophysiologic understanding of this process has identified that chronic inflammation plays a pivotal role. In this regard, given that both animal models and human studies have demonstrated that the interaction of P-selectin glycoprotein ligand-1 (PSGL-1) with P-selectin is not only critical for normal immune response but also is upregulated in the setting of metabolic syndrome, PSGL-1/P-selectin interactions provide a novel target for preventing and treating resultant disease. Current approaches of interfering with PSGL-1/P-selectin interactions include targeted antibodies, recombinant immunoglobulins that competitively bind P-selectin, and synthetic molecular therapies. Experimental models as well as clinical trials assessing the role of these modalities in a variety of diseases have continued to contribute to the understanding of PSGL-1/P-selectin interactions and have demonstrated the difficulty in creating clinically relevant therapeutics. Most recently, however, computational simulations have further enhanced our understanding of the structural features of PSGL-1 and related glycomimetics, which are responsible for high-affinity selectin interactions. Leveraging these insights for the design of next generation agents has thus led to development of a promising synthetic method for generating PSGL-1 glycosulfopeptide mimetics for the treatment of metabolic syndrome.
Collapse
Affiliation(s)
- Madhukar S Patel
- Department of Surgery, Massachusetts General Hospital, Boston, Mass; Department of Surgery, Beth Israel Deaconess Medical Center, Boston, Mass; Harvard Medical School, Boston, Mass
| | - David Miranda-Nieves
- Department of Surgery, Beth Israel Deaconess Medical Center, Boston, Mass; Harvard Medical School, Boston, Mass; Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, Mass
| | - Jiaxuan Chen
- Department of Surgery, Beth Israel Deaconess Medical Center, Boston, Mass; Harvard Medical School, Boston, Mass
| | - Carolyn A Haller
- Department of Surgery, Beth Israel Deaconess Medical Center, Boston, Mass; Harvard Medical School, Boston, Mass
| | - Elliot L Chaikof
- Department of Surgery, Beth Israel Deaconess Medical Center, Boston, Mass; Harvard Medical School, Boston, Mass.
| |
Collapse
|
72
|
Kuczkowski A, Brinkkoetter PT. Metabolism and homeostasis in the kidney: metabolic regulation through insulin signaling in the kidney. Cell Tissue Res 2017; 369:199-210. [DOI: 10.1007/s00441-017-2619-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 03/22/2017] [Indexed: 02/07/2023]
|
73
|
Mauro C, Smith J, Cucchi D, Coe D, Fu H, Bonacina F, Baragetti A, Cermenati G, Caruso D, Mitro N, Catapano AL, Ammirati E, Longhi MP, Okkenhaug K, Norata GD, Marelli-Berg FM. Obesity-Induced Metabolic Stress Leads to Biased Effector Memory CD4 + T Cell Differentiation via PI3K p110δ-Akt-Mediated Signals. Cell Metab 2017; 25:593-609. [PMID: 28190771 PMCID: PMC5355363 DOI: 10.1016/j.cmet.2017.01.008] [Citation(s) in RCA: 107] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 09/29/2016] [Accepted: 01/11/2017] [Indexed: 01/25/2023]
Abstract
Low-grade systemic inflammation associated to obesity leads to cardiovascular complications, caused partly by infiltration of adipose and vascular tissue by effector T cells. The signals leading to T cell differentiation and tissue infiltration during obesity are poorly understood. We tested whether saturated fatty acid-induced metabolic stress affects differentiation and trafficking patterns of CD4+ T cells. Memory CD4+ T cells primed in high-fat diet-fed donors preferentially migrated to non-lymphoid, inflammatory sites, independent of the metabolic status of the hosts. This was due to biased CD4+ T cell differentiation into CD44hi-CCR7lo-CD62Llo-CXCR3+-LFA1+ effector memory-like T cells upon priming in high-fat diet-fed animals. Similar phenotype was observed in obese subjects in a cohort of free-living people. This developmental bias was independent of any crosstalk between CD4+ T cells and dendritic cells and was mediated via direct exposure of CD4+ T cells to palmitate, leading to increased activation of a PI3K p110δ-Akt-dependent pathway upon priming.
Collapse
Affiliation(s)
- Claudio Mauro
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, EC1M 6BQ, UK.
| | - Joanne Smith
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, EC1M 6BQ, UK
| | - Danilo Cucchi
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, EC1M 6BQ, UK; Istituto Pasteur, Fondazione Cenci Bolognetti, Rome 00161, Italy
| | - David Coe
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, EC1M 6BQ, UK
| | - Hongmei Fu
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, EC1M 6BQ, UK
| | - Fabrizia Bonacina
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan 9-20133, Italy
| | - Andrea Baragetti
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan 9-20133, Italy
| | - Gaia Cermenati
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan 9-20133, Italy
| | - Donatella Caruso
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan 9-20133, Italy
| | - Nico Mitro
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan 9-20133, Italy
| | - Alberico L Catapano
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan 9-20133, Italy; IRCCS Multimedica, Milan 2-242091, Italy
| | - Enrico Ammirati
- De Gasperis Cardio Center, Niguarda Ca' Granda Hospital, Milan 3-20162, Italy
| | - Maria P Longhi
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, EC1M 6BQ, UK
| | - Klaus Okkenhaug
- Laboratory of Lymphocyte Signalling and Development, Babraham Institute, Cambridge, CB22 3AT, UK
| | - Giuseppe D Norata
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan 9-20133, Italy; School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Perth, WA 6102, Australia
| | - Federica M Marelli-Berg
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, EC1M 6BQ, UK.
| |
Collapse
|
74
|
Szkudelski T, Szkudelska K. Effects of AMPK activation on lipolysis in primary rat adipocytes: studies at different glucose concentrations. Arch Physiol Biochem 2017; 123:43-49. [PMID: 27656952 DOI: 10.1080/13813455.2016.1227853] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Adipose tissue plays a key role in energy homeostasis. Adenosine monophosphate (AMP)-activated protein kinase (AMPK) is an important intracellular energy sensor. Effects of activation of AMPK by aminomidazole-4-carboxamide ribonucleotide (AICAR) on lipolysis in the rat adipocytes were determined in the presence of 3 or 12 mM glucose. Response to epinephrine or dibutyryl-cAMP was higher in the presence of 12 mM glucose. AICAR decreased lipolysis, also when glucose was replaced by alanine or succinate and without decrease in cAMP levels. AICAR attenuated epinephrine-induced decrease in adenosine triphosphate (ATP) levels, reduced glucose uptake and lactate release. These results indicate that short-term activation of AMPK by AICAR in the rat adipocytes inhibits lipolysis, due to changes in the final, followed by protein kinase A (PKA), steps of the lipolytic cascade and improves intracellular energy status. Similar effects of AICAR were observed in the presence of 3 and 12 mM glucose, which indicates that the AMPK system is operative at high glucose concentrations.
Collapse
Affiliation(s)
- Tomasz Szkudelski
- a Department of Animal Physiology and Biochemistry , Poznan University of Life Sciences , Poznan , Poland
| | - Katarzyna Szkudelska
- a Department of Animal Physiology and Biochemistry , Poznan University of Life Sciences , Poznan , Poland
| |
Collapse
|
75
|
Tang A, Li C, Zou N, Zhang Q, Liu M, Zhang X. Angiotensin-(1-7) improves non-alcoholic steatohepatitis through an adiponectin-independent mechanism. Hepatol Res 2017; 47:116-122. [PMID: 26992300 DOI: 10.1111/hepr.12707] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 02/15/2016] [Accepted: 03/11/2016] [Indexed: 01/12/2023]
Abstract
AIM Recent evidence suggests that angiotensin-(1-7) [Ang-(1-7)] could improve non-alcoholic steatohepatitis (NASH) through an adiponectin-dependent mechanism. This study aimed to investigate whether and how Ang-(1-7) influences NASH without adiponectin. METHODS Adiponectin knockout mice were fed with a high fat diet (HFD) or normal chow for 6 months, and were subsequently infused with Ang-(1-7) or saline for 2 weeks. RESULTS We found that HFD-fed mice showed obesity, hyperlipidemia, NASH, and significantly increased levels of serum Ang-(1-7). Chronic infusion of Ang-(1-7) could reduce body weight, absolute and relative liver weight, and serum levels of total cholesterol, triglyceride, and low-density lipoprotein cholesterol in HFD-fed mice. In addition, Ang-(1-7) treatment could attenuate hepatocellular inflammation, steatosis, and ballooning with activation of the hepatic AMP-activated protein kinase signaling pathway in HFD-fed knockout mice. CONCLUSIONS These results showed the protective role of Ang-(1-7) in the development of NASH through an adiponectin-independent mechanism, which may be partially attributed to the activation of hepatic AMP-activated protein kinase pathway.
Collapse
Affiliation(s)
- Ailian Tang
- Department of Gastroenterology and Hepatology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Can Li
- Department of Gastroenterology and Hepatology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Nan Zou
- Department of Gastroenterology and Hepatology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Qian Zhang
- Department of Gastroenterology and Hepatology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Meiling Liu
- Department of Gastroenterology and Hepatology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Xia Zhang
- Department of Gastroenterology and Hepatology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| |
Collapse
|
76
|
Reynés B, Palou M, Palou A. Gene expression modulation of lipid and central energetic metabolism related genes by high-fat diet intake in the main homeostatic tissues. Food Funct 2017; 8:629-650. [DOI: 10.1039/c6fo01473a] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
HF diet feeding affects the energy balance by transcriptional metabolic adaptations, based in direct gene expression modulation, perinatal programing and transcriptional factor regulation, which could be affected by the animal model, gender or period of dietary treatment.
Collapse
Affiliation(s)
- Bàrbara Reynés
- Laboratory of Molecular Biology
- Nutrition and Biotechnology
- Universitat de les Illes Balears and CIBER de Fisiopatología de la Obesidad y Nutrición (CIBERobn)
- Palma de Mallorca
- Spain
| | - Mariona Palou
- Alimentómica SL (Spin off no. 001 from UIB)
- Palma Mallorca
- Spain
| | - Andreu Palou
- Laboratory of Molecular Biology
- Nutrition and Biotechnology
- Universitat de les Illes Balears and CIBER de Fisiopatología de la Obesidad y Nutrición (CIBERobn)
- Palma de Mallorca
- Spain
| |
Collapse
|
77
|
Szeto HH, Liu S, Soong Y, Alam N, Prusky GT, Seshan SV. Protection of mitochondria prevents high-fat diet–induced glomerulopathy and proximal tubular injury. Kidney Int 2016; 90:997-1011. [DOI: 10.1016/j.kint.2016.06.013] [Citation(s) in RCA: 163] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 05/31/2016] [Accepted: 06/02/2016] [Indexed: 12/19/2022]
|
78
|
Xiong X, Li Q, Cui W, Gao ZH, Liu JL. Deteriorated high-fat diet-induced diabetes caused by pancreatic β-cell-specific overexpression of Reg3β gene in mice. Endocrine 2016; 54:360-370. [PMID: 27259509 DOI: 10.1007/s12020-016-0998-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Accepted: 05/23/2016] [Indexed: 12/18/2022]
Abstract
Reg family proteins have long been implicated in islet β-cell proliferation, survival, and regeneration. In our previous study, we reported that Reg3β overexpression did not increase islet growth but prevented streptozotocin-induced islet damage by inducing specific genes. In order to explore its role in type 2 diabetes (T2D), we established high-fat diet (HFD)-induced obesity and diabetes in RIP-I/Reg3β mice. Glucose and insulin tolerance tests, immunofluorescence for insulin, eIF2α, and GLUT2 in islets, Western blots on phosphorylated AMPKα and hepatic histology were performed. Both RIP-I/Reg3β and wild-type mice gained weight rapidly and became hyperglycemic after 10 weeks on the HFD. However, the transgenic mice exhibited more significant acceleration in blood glucose levels, further deterioration of glucose intolerance and insulin resistance, and a lower intensity of insulin staining. Immunofluorescence revealed similar magnitude of islet compensation to a wild-type HFD. The normal GLUT2 distribution in the transgenic β-cells was disrupted and the staining was obviously diminished on the cell membrane. HFD feeding also caused a further decrease in the level of AMPKα phosphorylation in the transgenic islets. Our results suggest that unlike its protective effect against T1D, overexpressed Reg3β was unable to protect the β-cells against HFD-induced damage.
Collapse
Affiliation(s)
- Xiaoquan Xiong
- Fraser Laboratories for Diabetes Research, Department of Medicine, RI-McGill University Health Centre, Room E02.7220, 1001 Décarie Blvd, Montreal, QC, H4A 3J1, Canada
| | - Qing Li
- Fraser Laboratories for Diabetes Research, Department of Medicine, RI-McGill University Health Centre, Room E02.7220, 1001 Décarie Blvd, Montreal, QC, H4A 3J1, Canada
| | - Wei Cui
- Department of Endocrinology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Zu-Hua Gao
- Department of Pathology, RI-McGill University Health Centre, Room E04.1820, 1001 Decarie Boulevard, Montreal, QC, H4A 3J1, Canada.
| | - Jun-Li Liu
- Fraser Laboratories for Diabetes Research, Department of Medicine, RI-McGill University Health Centre, Room E02.7220, 1001 Décarie Blvd, Montreal, QC, H4A 3J1, Canada.
- Montreal Diabetes Research Centre, Montreal, Canada.
| |
Collapse
|
79
|
Zhao Z, Barcus M, Kim J, Lum KL, Mills C, Lei XG. High Dietary Selenium Intake Alters Lipid Metabolism and Protein Synthesis in Liver and Muscle of Pigs. J Nutr 2016; 146:1625-33. [PMID: 27466604 PMCID: PMC4997278 DOI: 10.3945/jn.116.229955] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 06/08/2016] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Prolonged high intakes of dietary selenium have been shown to induce gestational diabetes in rats and hyperinsulinemia in pigs. OBJECTIVE Two experiments were conducted to explore metabolic and molecular mechanisms for the diabetogenic potential of high dietary selenium intakes in pigs. METHODS In Expt. 1, 16 Yorkshire-Landrace-Hampshire crossbred pigs (3 wk old, body weight = 7.5 ± 0.81 kg, 50% males and 50% females) were fed a corn-soybean meal basal diet supplemented with 0.3 or 1.0 mg Se/kg (as selenium-enriched yeast for 6 wk). In Expt. 2, 12 pigs of the same crossbreed (6 wk old, body weight = 16.0 ± 1.8 kg) were fed a similar basal diet supplemented with 0.3 or 3.0 mg Se/kg for 11 wk. Biochemical and gene and protein expression profiles of lipid and protein metabolism and selenoproteins in plasma, liver, muscle, and adipose tissues were analyzed. RESULTS In Expt. 1, the 1-mg-Se/kg diet did not affect body weight or plasma concentrations of glucose and nonesterified fatty acids. In Expt. 2, the 3-mg-Se/kg diet, compared with the 0.3-mg-Se/kg diet, increased (P < 0.05) concentrations of plasma insulin (0.2 compared with 0.4 ng/mL), liver and adipose lipids (41% to 2.4-fold), and liver and muscle protein (10-14%). In liver, the 3-mg-Se/kg diet upregulated (P < 0.05) the expression, activity, or both of key factors related to gluconeogenesis [phosphoenolpyruvate carboxykinase (PEPCK); 13%], lipogenesis [sterol regulatory element binding protein 1 (SREBP1), acetyl-coenzyme A carboxylase (ACC), and fatty acid synthase (FASN); 46-90%], protein synthesis [insulin receptor (INSR), P70 ribosomal protein S6 kinase (P70), and phosphorylated ribosomal protein S6 (P-S6); 88-105%], energy metabolism [AMP-activated protein kinase (AMPK); up to 2.8-fold], and selenoprotein glutathione peroxidase 3 (GPX3; 1.4-fold) and suppressed (P < 0.05) mRNA levels of lipolysis gene cytochrome P450, family 7, subfamily A, polypeptide 1 (CYP7A1; 88%) and selenoprotein gene selenoprotein W1 (SEPW1; 46%). In muscle, the 3-mg-Se/kg diet exerted no effect on the lipid profiles but enhanced (P < 0.05) expression of P-S6 and mammalian target of rapamycin (mTOR; 42-176%; protein synthesis); selenoprotein P (SELP; 40-fold); and tumor suppressor protein 53 (P53) and peroxisome proliferator-activated receptor γ (PPARG; 52-58%; lipogenesis) and suppressed (P < 0.05) expression of INSR (59%; insulin signaling); selenoprotein S (SELS); deiodinases, iodothyronine, type I (DIO1); and thioredoxin reductase 1 (TXNRD1; 50%; selenoproteins); and ACC1 and FASN (35-51%; lipogenesis). CONCLUSION Our research showed novel roles, to our best knowledge, and mechanisms of high selenium intakes in regulating the metabolism of protein, along with that of lipid, in a tissue-specific fashion in pigs.
Collapse
Affiliation(s)
| | | | | | | | | | - Xin Gen Lei
- Department of Animal Science, Cornell University, Ithaca, NY
| |
Collapse
|
80
|
Mottillo EP, Desjardins EM, Crane JD, Smith BK, Green AE, Ducommun S, Henriksen TI, Rebalka IA, Razi A, Sakamoto K, Scheele C, Kemp BE, Hawke TJ, Ortega J, Granneman JG, Steinberg GR. Lack of Adipocyte AMPK Exacerbates Insulin Resistance and Hepatic Steatosis through Brown and Beige Adipose Tissue Function. Cell Metab 2016; 24:118-29. [PMID: 27411013 PMCID: PMC5239668 DOI: 10.1016/j.cmet.2016.06.006] [Citation(s) in RCA: 240] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 04/20/2016] [Accepted: 06/10/2016] [Indexed: 12/22/2022]
Abstract
Brown (BAT) and white (WAT) adipose tissues play distinct roles in maintaining whole-body energy homeostasis, and their dysfunction can contribute to non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes. The AMP-activated protein kinase (AMPK) is a cellular energy sensor, but its role in regulating BAT and WAT metabolism is unclear. We generated an inducible model for deletion of the two AMPK β subunits in adipocytes (iβ1β2AKO) and found that iβ1β2AKO mice were cold intolerant and resistant to β-adrenergic activation of BAT and beiging of WAT. BAT from iβ1β2AKO mice had impairments in mitochondrial structure, function, and markers of mitophagy. In response to a high-fat diet, iβ1β2AKO mice more rapidly developed liver steatosis as well as glucose and insulin intolerance. Thus, AMPK in adipocytes is vital for maintaining mitochondrial integrity, responding to pharmacological agents and thermal stress, and protecting against nutrient-overload-induced NAFLD and insulin resistance.
Collapse
Affiliation(s)
- Emilio P Mottillo
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, 1280 Main St. W., Hamilton, Ontario L8N 3Z5, Canada
| | - Eric M Desjardins
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, 1280 Main St. W., Hamilton, Ontario L8N 3Z5, Canada
| | - Justin D Crane
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, 1280 Main St. W., Hamilton, Ontario L8N 3Z5, Canada
| | - Brennan K Smith
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, 1280 Main St. W., Hamilton, Ontario L8N 3Z5, Canada
| | - Alex E Green
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, 1280 Main St. W., Hamilton, Ontario L8N 3Z5, Canada
| | - Serge Ducommun
- Nestlé Institute of Health Sciences SA, EPFL Innovation Park, Lausanne, Switzerland
| | - Tora I Henriksen
- The Centre of Inflammation and Metabolism and the Centre for Physical Activity Research, Department of Infectious Diseases, Rigshospitalet, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Irena A Rebalka
- Department of Pathology and Molecular Medicine, McMaster University, 1280 Main St. W., Hamilton, Ontario L8N 3Z5, Canada
| | - Aida Razi
- Department of Biochemistry and Biomedical Sciences, McMaster University, 1280 Main St. W., Hamilton, Ontario L8N 3Z5, Canada
| | - Kei Sakamoto
- Nestlé Institute of Health Sciences SA, EPFL Innovation Park, Lausanne, Switzerland
| | - Camilla Scheele
- The Centre of Inflammation and Metabolism and the Centre for Physical Activity Research, Department of Infectious Diseases, Rigshospitalet, University of Copenhagen, 2100 Copenhagen, Denmark; Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, 2200 Copenhagen N, Denmark
| | - Bruce E Kemp
- St Vincent's Institute and Department of Medicine, University of Melbourne, Fitzroy, Victoria 3065, Australia; Mary MacKillop Institute for Health Research Australian Catholic University, Victoria Parade, Fitzroy, Victoria 3065, Australia
| | - Thomas J Hawke
- Department of Pathology and Molecular Medicine, McMaster University, 1280 Main St. W., Hamilton, Ontario L8N 3Z5, Canada
| | - Joaquin Ortega
- Department of Biochemistry and Biomedical Sciences, McMaster University, 1280 Main St. W., Hamilton, Ontario L8N 3Z5, Canada
| | - James G Granneman
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit 48201, MI, USA
| | - Gregory R Steinberg
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, 1280 Main St. W., Hamilton, Ontario L8N 3Z5, Canada; Department of Biochemistry and Biomedical Sciences, McMaster University, 1280 Main St. W., Hamilton, Ontario L8N 3Z5, Canada.
| |
Collapse
|
81
|
Kim SM, Neuendorff N, Chapkin RS, Earnest DJ. Role of Inflammatory Signaling in the Differential Effects of Saturated and Poly-unsaturated Fatty Acids on Peripheral Circadian Clocks. EBioMedicine 2016; 7:100-11. [PMID: 27322464 PMCID: PMC4913702 DOI: 10.1016/j.ebiom.2016.03.037] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Revised: 03/23/2016] [Accepted: 03/23/2016] [Indexed: 12/12/2022] Open
Abstract
Inflammatory signaling may play a role in high-fat diet (HFD)-related circadian clock disturbances that contribute to systemic metabolic dysregulation. Therefore, palmitate, the prevalent proinflammatory saturated fatty acid (SFA) in HFD and the anti-inflammatory, poly-unsaturated fatty acid (PUFA), docosahexaenoic acid (DHA), were analyzed for effects on circadian timekeeping and inflammatory responses in peripheral clocks. Prolonged palmitate, but not DHA, exposure increased the period of fibroblast Bmal1-dLuc rhythms. Acute palmitate treatment produced phase shifts of the Bmal1-dLuc rhythm that were larger in amplitude as compared to DHA. These phase-shifting effects were time-dependent and contemporaneous with rhythmic changes in palmitate-induced inflammatory responses. Fibroblast and differentiated adipocyte clocks exhibited cell-specific differences in the time-dependent nature of palmitate-induced shifts and inflammation. DHA and other inhibitors of inflammatory signaling (AICAR, cardamonin) repressed palmitate-induced proinflammatory responses and phase shifts of the fibroblast clock, suggesting that SFA-mediated inflammatory signaling may feed back to modulate circadian timekeeping in peripheral clocks. The saturated fatty acid (SFA) palmitate differentially modulates the circadian timekeeping mechanism in peripheral clocks; Palmitate induces time-dependent phase shifts that coincide with its rhythmic induction of inflammatory signaling; Time-dependent nature of the palmitate-induced phase shifts and inflammatory signaling is cell specific; Inhibitors of inflammatory signaling repress the proinflammatory and phase shifting effects of palmitate; Inflammatory signaling plays a role in the mechanism by which palmitate alters circadian timekeeping in peripheral clocks.
Circadian or 24-hour clocks throughout the body mediate the local temporal coordination of tissue- or cell-specific processes necessary for normal inflammatory responses and metabolic homeostasis. Dysregulation of peripheral clocks and their timekeeping function contribute to obesity-related metabolic disorders (e.g., type 2 diabetes). Our data unveil a novel mechanism by which mutual interactions between peripheral clocks and inflammatory signaling pathways dysregulate circadian timekeeping, and exacerbate proinflammatory responses to saturated fatty acids. These studies will guide the development of chronotherapeutic drug and/or dietary omega-3 fatty acid treatments for managing and preventing metabolic disorders and other inflammation-related pathologies (e.g., cardiovascular disease, stroke, arthritis).
Collapse
Affiliation(s)
- Sam-Moon Kim
- Department of Biology, Texas A&M University, College Station, TX 77843-3258, USA; Center for Biological Clocks Research, Texas A&M University, College Station, TX 77843-3258, USA
| | - Nichole Neuendorff
- Department of Neuroscience and Experimental Therapeutics, Texas A&M Health Science Center, College of Medicine, Bryan, TX 77807-3260, USA
| | - Robert S Chapkin
- Program in Integrative Nutrition & Complex Diseases, Center for Translational Environmental Health Research, Texas A&M University, College Station, TX 77843-2253, USA; Department of Nutrition & Food Science, Texas A&M University, College Station, TX 77843-2253, USA; Department of Microbial Pathogenesis and Immunology, Texas A&M University System Health Science Center, College Station, TX 77807-3260, USA.
| | - David J Earnest
- Department of Biology, Texas A&M University, College Station, TX 77843-3258, USA; Center for Biological Clocks Research, Texas A&M University, College Station, TX 77843-3258, USA; Department of Neuroscience and Experimental Therapeutics, Texas A&M Health Science Center, College of Medicine, Bryan, TX 77807-3260, USA.
| |
Collapse
|
82
|
Fu X, Zhu M, Zhang S, Foretz M, Viollet B, Du M. Obesity Impairs Skeletal Muscle Regeneration Through Inhibition of AMPK. Diabetes 2016; 65:188-200. [PMID: 26384382 PMCID: PMC4686944 DOI: 10.2337/db15-0647] [Citation(s) in RCA: 108] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 09/10/2015] [Indexed: 12/18/2022]
Abstract
Obesity is increasing rapidly worldwide and is accompanied by many complications, including impaired muscle regeneration. The obese condition is known to inhibit AMPK activity in multiple tissues. We hypothesized that the loss of AMPK activity is a major reason for hampered muscle regeneration in obese subjects. We found that obesity inhibits AMPK activity in regenerating muscle, which was associated with impeded satellite cell activation and impaired muscle regeneration. To test the mediatory role of AMPKα1, we knocked out AMPKα1 and found that both proliferation and differentiation of satellite cells are reduced after injury and that muscle regeneration is severely impeded, reminiscent of hampered muscle regeneration seen in obese subjects. Transplanted satellite cells with AMPKα1 deficiency had severely impaired myogenic capacity in regenerating muscle fibers. We also found that attenuated muscle regeneration in obese mice is rescued by AICAR, a drug that specifically activates AMPK, but AICAR treatment failed to improve muscle regeneration in obese mice with satellite cell-specific AMPKα1 knockout, demonstrating the importance of AMPKα1 in satellite cell activation and muscle regeneration. In summary, AMPKα1 is a key mediator linking obesity and impaired muscle regeneration, providing a convenient drug target to facilitate muscle regeneration in obese populations.
Collapse
Affiliation(s)
- Xing Fu
- Washington Center for Muscle Biology, Department of Animal Sciences and Department of Pharmaceutical Sciences, Washington State University, Pullman, WA
| | - Meijun Zhu
- School of Food Science, Washington State University, Pullman, WA
| | - Shuming Zhang
- School of Food Science, Washington State University, Pullman, WA
| | - Marc Foretz
- INSERM U1016, Institut Cochin, Paris, France Université Paris Descartes, Sorbonne Paris Cité, Paris, France CNRS UMR 8104, Paris, France
| | - Benoit Viollet
- INSERM U1016, Institut Cochin, Paris, France Université Paris Descartes, Sorbonne Paris Cité, Paris, France CNRS UMR 8104, Paris, France
| | - Min Du
- Washington Center for Muscle Biology, Department of Animal Sciences and Department of Pharmaceutical Sciences, Washington State University, Pullman, WA
| |
Collapse
|
83
|
Slámová K, Papoušek F, Janovská P, Kopecký J, Kolář F. Adverse effects of AMP-activated protein kinase alpha2-subunit deletion and high-fat diet on heart function and ischemic tolerance in aged female mice. Physiol Res 2015; 65:33-42. [PMID: 26596312 DOI: 10.33549/physiolres.932979] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
AMP-activated protein kinase (AMPK) plays a role in metabolic regulation under stress conditions, and inadequate AMPK signaling may be also involved in aging process. The aim was to find out whether AMPK alpha2-subunit deletion affects heart function and ischemic tolerance of adult and aged mice. AMPK alpha2(-/-) (KO) and wild type (WT) female mice were compared at the age of 6 and 18 months. KO mice exhibited subtle myocardial AMPK alpha2-subunit protein level, but no difference in AMPK alpha1-subunit was detected between the strains. Both alpha1- and alpha2-subunits of AMPK and their phosphorylation decreased with advanced age. Left ventricular fractional shortening was lower in KO than in WT mice of both age groups and this difference was maintained after high-fat feeding. Infarct size induced by global ischemia/reperfusion of isolated hearts was similar in both strains at 6 months of age. Aged WT but not KO mice exhibited improved ischemic tolerance compared with the younger group. High-fat feeding for 6 months during aging abolished the infarct size-reduction in WT without affecting KO animals; nevertheless, the extent of injury remained larger in KO mice. The results demonstrate that adverse effects of AMPK alpha2-subunit deletion and high-fat feeding on heart function and myocardial ischemic tolerance in aged female mice are not additive.
Collapse
Affiliation(s)
- K Slámová
- Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic.
| | | | | | | | | |
Collapse
|
84
|
Punicalagin, an active component in pomegranate, ameliorates cardiac mitochondrial impairment in obese rats via AMPK activation. Sci Rep 2015; 5:14014. [PMID: 26369619 PMCID: PMC4642696 DOI: 10.1038/srep14014] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 07/30/2015] [Indexed: 01/17/2023] Open
Abstract
Obesity is associated with an increasing prevalence of cardiovascular diseases and metabolic syndrome. It is of paramount importance to reduce obesity-associated cardiac dysfunction and impaired energy metabolism. In this study, the activation of the AMP-activated protein kinase (AMPK) pathway by punicalagin (PU), a major ellagitannin in pomegranate was investigated in the heart of a rat obesity model. In male SD rats, eight-week administration of 150 mg/kg pomegranate extract (PE) containing 40% punicalagin sufficiently prevented high-fat diet (HFD)-induced obesity associated accumulation of cardiac triglyceride and cholesterol as well as myocardial damage. Concomitantly, the AMPK pathway was activated, which may account for prevention of mitochondrial loss via upregulating mitochondrial biogenesis and amelioration of oxidative stress via enhancing phase II enzymes in the hearts of HFD rats. Together with the normalized expression of uncoupling proteins and mitochondrial dynamic regulators, PE significantly prevented HFD-induced cardiac ATP loss. Through in vitro cultures, we showed that punicalagin was the predominant component that activated AMPK by quickly decreasing the cellular ATP/ADP ratio specifically in cardiomyocytes. Our findings demonstrated that punicalagin, the major active component in PE, could modulate mitochondria and phase II enzymes through AMPK pathway to prevent HFD-induced cardiac metabolic disorders.
Collapse
|
85
|
Shiwa M, Yoneda M, Okubo H, Ohno H, Kobuke K, Monzen Y, Kishimoto R, Nakatsu Y, Asano T, Kohno N. Distinct Time Course of the Decrease in Hepatic AMP-Activated Protein Kinase and Akt Phosphorylation in Mice Fed a High Fat Diet. PLoS One 2015; 10:e0135554. [PMID: 26266809 PMCID: PMC4534138 DOI: 10.1371/journal.pone.0135554] [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: 04/14/2015] [Accepted: 07/23/2015] [Indexed: 12/25/2022] Open
Abstract
AMP-activated protein kinase (AMPK) plays an important role in insulin resistance, which is characterized by the impairment of the insulin-Akt signaling pathway. However, the time course of the decrease in AMPK and Akt phosphorylation in the liver during the development of obesity and insulin resistance caused by feeding a high fat diet (HFD) remains controversial. Moreover, it is unclear whether the impairment of AMPK and Akt signaling pathways is reversible when changing from a HFD to a standard diet (SD). Male ddY mice were fed the SD or HFD for 3 to 28 days, or fed the HFD for 14 days, followed by the SD for 14 days. We examined the time course of the expression and phosphorylation levels of AMPK and Akt in the liver by immunoblotting. After 3 days of feeding on the HFD, mice gained body weight, resulting in an increased oil red O staining, indicative of hepatic lipid accumulation, and significantly decreased AMPK phosphorylation, in comparison with mice fed the SD. After 14 days on the HFD, systemic insulin resistance occurred and Akt phosphorylation significantly decreased. Subsequently, a change from the HFD to SD for 3 days, after 14 days on the HFD, ameliorated the impairment of AMPK and Akt phosphorylation and systemic insulin resistance. Our findings indicate that AMPK phosphorylation decreases early upon feeding a HFD and emphasizes the importance of prompt lifestyle modification for decreasing the risk of developing diabetes.
Collapse
Affiliation(s)
- Mami Shiwa
- Department of Molecular and Internal Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Masayasu Yoneda
- Department of Molecular and Internal Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Hirofumi Okubo
- Department of Molecular and Internal Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Haruya Ohno
- Department of Molecular and Internal Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Kazuhiro Kobuke
- Department of Molecular and Internal Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Yuko Monzen
- Department of Molecular and Internal Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Rui Kishimoto
- Department of Molecular and Internal Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Yusuke Nakatsu
- Department of Biomedical Chemistry, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Tomoichiro Asano
- Department of Biomedical Chemistry, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Nobuoki Kohno
- Department of Molecular and Internal Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| |
Collapse
|
86
|
Khan S, Jena G. The role of butyrate, a histone deacetylase inhibitor in diabetes mellitus: experimental evidence for therapeutic intervention. Epigenomics 2015; 7:669-80. [DOI: 10.2217/epi.15.20] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The contribution of epigenetic mechanisms in diabetes mellitus (DM), β-cell reprogramming and its complications is an emerging concept. Recent evidence suggests that there is a link between DM and histone deacetylases (HDACs), because HDAC inhibitors promote β-cell differentiation, proliferation, function and improve insulin resistance. Moreover, gut microbes and diet-derived products can alter the host epigenome. Furthermore, butyrate and butyrate-producing microbes are decreased in DM. Butyrate is a short-chain fatty acid produced from the fermentation of dietary fibers by microbiota and has been proven as an HDAC inhibitor. The present review provides a pragmatic interpretation of chromatin-dependent and independent complex signaling/mechanisms of butyrate for the treatment of Type 1 and Type 2 DM, with an emphasis on the promising strategies for its drugability and therapeutic implication.
Collapse
Affiliation(s)
- Sabbir Khan
- Facility for Risk Assessment & Intervention Studies, Department of Pharmacology & Toxicology, National Institute of Pharmaceutical Education & Research, Sector-67, S.A.S. Nagar, Punjab 60 062, India
| | - Gopabandhu Jena
- Facility for Risk Assessment & Intervention Studies, Department of Pharmacology & Toxicology, National Institute of Pharmaceutical Education & Research, Sector-67, S.A.S. Nagar, Punjab 60 062, India
| |
Collapse
|
87
|
Vasamsetti SB, Karnewar S, Kanugula AK, Thatipalli AR, Kumar JM, Kotamraju S. Metformin inhibits monocyte-to-macrophage differentiation via AMPK-mediated inhibition of STAT3 activation: potential role in atherosclerosis. Diabetes 2015; 64:2028-41. [PMID: 25552600 DOI: 10.2337/db14-1225] [Citation(s) in RCA: 292] [Impact Index Per Article: 32.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Accepted: 12/20/2014] [Indexed: 12/12/2022]
Abstract
Monocyte-to-macrophage differentiation is a critical event that accentuates atherosclerosis by promoting an inflammatory environment within the vessel wall. In this study, we investigated the molecular mechanisms responsible for monocyte-to-macrophage differentiation and, subsequently, the effect of metformin in regressing angiotensin II (Ang-II)-mediated atheromatous plaque formation in ApoE(-/-) mice. AMPK activity was dose and time dependently downregulated during phorbol myristate acetate (PMA)-induced monocyte-to-macrophage differentiation, which was accompanied by an upregulation of proinflammatory cytokine production. Of note, AMPK activators metformin and AICAR significantly attenuated PMA-induced monocyte-to-macrophage differentiation and proinflammatory cytokine production. However, inhibition of AMPK activity alone by compound C was ineffective in promoting monocyte-to-macrophage differentiation in the absence of PMA. On the other hand, inhibition of c-Jun N-terminal kinase activity inhibited PMA-induced inflammation but not differentiation, suggesting that inflammation and differentiation are independent events. In contrast, inhibition of STAT3 activity inhibited both inflammation and monocyte-to-macrophage differentiation. By decreasing STAT3 phosphorylation, metformin and AICAR through increased AMPK activation caused inhibition of monocyte-to-macrophage differentiation. Metformin attenuated Ang-II-induced atheromatous plaque formation and aortic aneurysm in ApoE(-/-) mice partly by reducing monocyte infiltration. We conclude that the AMPK-STAT3 axis plays a pivotal role in regulating monocyte-to-macrophage differentiation and that by decreasing STAT3 phosphorylation through increased AMPK activity, AMPK activators inhibit monocyte-to-macrophage differentiation.
Collapse
Affiliation(s)
- Sathish Babu Vasamsetti
- Centre for Chemical Biology, Council of Scientific and Industrial Research (CSIR)-Indian Institute of Chemical Technology, Hyderabad, India
| | - Santosh Karnewar
- Centre for Chemical Biology, Council of Scientific and Industrial Research (CSIR)-Indian Institute of Chemical Technology, Hyderabad, India
| | - Anantha Koteswararao Kanugula
- Centre for Chemical Biology, Council of Scientific and Industrial Research (CSIR)-Indian Institute of Chemical Technology, Hyderabad, India
| | | | | | - Srigiridhar Kotamraju
- Centre for Chemical Biology, Council of Scientific and Industrial Research (CSIR)-Indian Institute of Chemical Technology, Hyderabad, India
| |
Collapse
|
88
|
Marineli RDS, Moura CS, Moraes ÉA, Lenquiste SA, Lollo PCB, Morato PN, Amaya-Farfan J, Maróstica MR. Chia (Salvia hispanica L.) enhances HSP, PGC-1α expressions and improves glucose tolerance in diet-induced obese rats. Nutrition 2014; 31:740-8. [PMID: 25837222 DOI: 10.1016/j.nut.2014.11.009] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 10/02/2014] [Accepted: 11/17/2014] [Indexed: 01/14/2023]
Abstract
OBJECTIVE The aim of this study was to investigate the effects of chia seed and chia oil on heat shock protein (HSP) and related parameters in diet-induced obese rats. METHODS Animals were divided in six groups: control, high-fat and high-fructose diet (HFF), and HFF with chia seed or chia oil in short (6-wk) and long (12-wk) treatments. Plasma indicators of glucose tolerance and liver damage, skeletal muscle expression of antioxidant enzymes, and proteins controlling oxidative energy metabolism were determined. The limit of significance was set at P < 0.05. RESULTS The HFF diet induced glucose intolerance, insulin resistance, oxidative stress, and altered parameters related to obesity complications. The consumption of chia seed or chia oil did not reduce body weight gain or abdominal fat accumulation. However, chia seed and chia oil in both treatments improved glucose and insulin tolerance. Chia oil in both treatments induced expression of HSP70 and HSP25 in skeletal muscle. Short treatment with chia seed increased expression of HSP70, but not HSP25. Chia oil in both treatments restored superoxide dismutase and glutathione peroxidase expression. Extended treatment with chia seed and short treatment with chia oil restored peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) expression. CONCLUSION Chia oil restored the antioxidant system and induced the expression of a higher number of proteins than chia seed. The present study demonstrated new properties and molecular mechanisms associated with the beneficial effects of chia seed and chia oil consumption in diet-induced obese rats.
Collapse
Affiliation(s)
- Rafaela da Silva Marineli
- Food and Nutrition Department, Faculty of Food Engineering, University of Campinas, Campinas, São Paulo, Brazil
| | - Carolina Soares Moura
- Food and Nutrition Department, Faculty of Food Engineering, University of Campinas, Campinas, São Paulo, Brazil
| | - Érica Aguiar Moraes
- Food and Nutrition Department, Faculty of Food Engineering, University of Campinas, Campinas, São Paulo, Brazil
| | - Sabrina Alves Lenquiste
- Food and Nutrition Department, Faculty of Food Engineering, University of Campinas, Campinas, São Paulo, Brazil
| | | | - Priscila Neder Morato
- Food and Nutrition Department, Faculty of Food Engineering, University of Campinas, Campinas, São Paulo, Brazil
| | - Jaime Amaya-Farfan
- Food and Nutrition Department, Faculty of Food Engineering, University of Campinas, Campinas, São Paulo, Brazil
| | - Mário Roberto Maróstica
- Food and Nutrition Department, Faculty of Food Engineering, University of Campinas, Campinas, São Paulo, Brazil.
| |
Collapse
|
89
|
Hematopoietic tissue factor-protease-activated receptor 2 signaling promotes hepatic inflammation and contributes to pathways of gluconeogenesis and steatosis in obese mice. THE AMERICAN JOURNAL OF PATHOLOGY 2014; 185:524-35. [PMID: 25476527 DOI: 10.1016/j.ajpath.2014.10.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Revised: 10/08/2014] [Accepted: 10/14/2014] [Indexed: 12/19/2022]
Abstract
Failure to inhibit hepatic gluconeogenesis is a major mechanism contributing to fasting hyperglycemia in type 2 diabetes and, along with steatosis, is the hallmark of hepatic insulin resistance. Obesity is associated with chronic inflammation in multiple tissues, and hepatic inflammation is mechanistically linked to both steatosis and hepatic insulin resistance. Here, we delineate a role for coagulation signaling via tissue factor (TF) and proteinase-activated receptor 2 (PAR2) in obesity-mediated hepatic inflammation, steatosis, and gluconeogenesis. In diet-induced obese mice, TF tail signaling independent of PAR2 drives CD11b(+)CD11c(+) hepatic macrophage recruitment, and TF-PAR2 signaling contributes to the accumulation of hepatic CD8(+) T cells. Transcripts of key pathways of gluconeogenesis, lipogenesis, and inflammatory cytokines were reduced in high-fat diet-fed mice that lack the cytoplasmic domain of TF (F3) (TF(ΔCT)) or that are deficient in PAR2 (F2rl1), as well as by pharmacological inhibition of TF-PAR2 signaling in diet-induced obese mice. These gluconeogenic, lipogenic, and inflammatory pathway transcripts were similarly reduced in response to genetic ablation or pharmacological inhibition of TF-PAR2 signaling in hematopoietic cells and were mechanistically associated with activation of AMP-activated protein kinase (AMPK). These findings indicate that hematopoietic TF-PAR2 signaling plays a pivotal role in the hepatic inflammatory responses, steatosis, and hepatic insulin resistance that lead to systemic insulin resistance and type 2 diabetes in obesity.
Collapse
|
90
|
Wan Z, Durrer C, Mah D, Simtchouk S, Robinson E, Little JP. Reduction of AMPK activity and altered MAPKs signalling in peripheral blood mononuclear cells in response to acute glucose ingestion following a short-term high fat diet in young healthy men. Metabolism 2014; 63:1209-16. [PMID: 25037151 DOI: 10.1016/j.metabol.2014.06.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 06/04/2014] [Accepted: 06/09/2014] [Indexed: 11/19/2022]
Abstract
BACKGROUND Peripheral blood mononuclear cells (PBMCs) are known to respond to systematic changes in nutrient availability. The impact of a short-term high fat diet (HFD), with and without acute glucose ingestion, on the energy-sensing enzyme 5' AMP-activated protein kinase (AMPK) as well as mitochondrial oxidative phosphorylation (OXPHOS) proteins in PBMCs is currently unknown. METHODS Nine healthy, lean young males participated in a 7 day HFD intervention, designed to induce transient glucose intolerance. The phosphorylation status and total protein content of AMPK and inflammatory mitogen-activated protein kinases (MAPKs), and total OXPHOS protein in PBMCs, along with circulating cytokines, were assessed in the fasted state and following an oral glucose tolerance test (OGTT) before and after the HFD. RESULTS One week of HFD resulted in relative glucose intolerance. The HFD resulted in a reduction of AMPK phosphorylation under fasting basal conditions and following the OGTT (both P<0.05), while there were no differences in OXPHOS protein expression. Although the short-term HFD had no effect on basal phosphorylation of p38, JNK or ERK1/2, the activation of MAPKs signalling in response to glucose ingestion was attenuated post-HFD as compared to pre-HFD (P<0.05 for all). Circulating cytokines were not significantly affected by the HFD. CONCLUSIONS We conclude that impaired glucose tolerance in response to 7 day HFD resulted in decreased AMPK activity and impaired glucose-stimulated MAPK activation following glucose ingestion in vivo in PBMCs from young, lean subjects. Further studies are warranted to explore how dietary manipulations impact interplay between AMPK and inflammatory signalling, along with immune function, in PBMCs.
Collapse
Affiliation(s)
- Zhongxiao Wan
- School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, British Columbia, Canada
| | - Cody Durrer
- School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, British Columbia, Canada
| | - Dorrian Mah
- School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, British Columbia, Canada
| | - Svetlana Simtchouk
- School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, British Columbia, Canada
| | - Emily Robinson
- School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, British Columbia, Canada
| | - Jonathan P Little
- School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, British Columbia, Canada
| |
Collapse
|
91
|
Liang L, Shou XL, Zhao HK, Ren GQ, Wang JB, Wang XH, Ai WT, Maris JR, Hueckstaedt LK, Ma AQ, Zhang Y. Antioxidant catalase rescues against high fat diet-induced cardiac dysfunction via an IKKβ-AMPK-dependent regulation of autophagy. Biochim Biophys Acta Mol Basis Dis 2014; 1852:343-52. [PMID: 24993069 DOI: 10.1016/j.bbadis.2014.06.027] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2014] [Revised: 06/10/2014] [Accepted: 06/22/2014] [Indexed: 01/08/2023]
Abstract
Autophagy, a conservative degradation process for long-lived and damaged proteins, participates in a variety of biological processes including obesity. However, the precise mechanism of action behind obesity-induced changes in autophagy still remains elusive. This study was designed to examine the role of the antioxidant catalase in high fat diet-induced changes in cardiac geometry and function as well as the underlying mechanism of action involved with a focus on autophagy. Wild-type (WT) and transgenic mice with cardiac overexpression of catalase were fed low or high fat diet for 20 weeks prior to assessment of myocardial geometry and function. High fat diet intake triggered obesity, hyperinsulinemia, and hypertriglyceridemia, the effects of which were unaffected by catalase transgene. Myocardial geometry and function were compromised with fat diet intake as manifested by cardiac hypertrophy, enlarged left ventricular end systolic and diastolic diameters, fractional shortening, cardiomyocyte contractile capacity and intracellular Ca²⁺ mishandling, the effects of which were ameliorated by catalase. High fat diet intake promoted reactive oxygen species production and suppressed autophagy in the heart, the effects of which were attenuated by catalase. High fat diet intake dampened phosphorylation of inhibitor kappa B kinase β(IKKβ), AMP-activated protein kinase (AMPK) and tuberous sclerosis 2 (TSC2) while promoting phosphorylation of mTOR, the effects of which were ablated by catalase. In vitro study revealed that palmitic acid compromised cardiomyocyte autophagy and contractile function in a manner reminiscent of fat diet intake, the effect of which was significantly alleviated by inhibition of IKKβ, activation of AMPK and induction of autophagy. Taken together, our data revealed that the antioxidant catalase counteracts against high fat diet-induced cardiac geometric and functional anomalies possibly via an IKKβ-AMPK-dependent restoration of myocardial autophagy. This article is part of a Special Issue entitled: Autophagy and protein quality control in cardiometabolic diseases.
Collapse
Affiliation(s)
- Lei Liang
- Department of Cardiology, The People's Hospital of Shaanxi Province, Xi'an, China; Department of Cardiology, The First Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, China
| | - Xi-Ling Shou
- Department of Cardiology, The People's Hospital of Shaanxi Province, Xi'an, China; Department of Cardiology, The First Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, China
| | - Hai-Kang Zhao
- Department of Neurosurgery, The Second Affiliated Hospital, Xi'an Medical University, Xi'an, China
| | - Gu-Qun Ren
- Department of Cardiology, The Second Affiliated Hospital, Xi'an Medical University, Xi'an, China
| | - Jian-Bang Wang
- Department of Cardiology, The Second Affiliated Hospital, Xi'an Medical University, Xi'an, China
| | - Xi-Hui Wang
- Department of Cardiology, The Second Affiliated Hospital, Xi'an Medical University, Xi'an, China
| | - Wen-Ting Ai
- Department of Cardiology, The First Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, China
| | - Jackie R Maris
- Center for Cardiovascular Research and Alternative Medicine, University of Wyoming College of Health Sciences, Laramie, WY 82071, USA
| | - Lindsay K Hueckstaedt
- Center for Cardiovascular Research and Alternative Medicine, University of Wyoming College of Health Sciences, Laramie, WY 82071, USA
| | - Ai-Qun Ma
- Department of Cardiology, The First Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, China.
| | - Yingmei Zhang
- Center for Cardiovascular Research and Alternative Medicine, University of Wyoming College of Health Sciences, Laramie, WY 82071, USA.
| |
Collapse
|
92
|
Xu XJ, Valentine RJ, Ruderman NB. AMP-activated Protein Kinase (AMPK): Does This Master Regulator of Cellular Energy State Distinguish Insulin Sensitive from Insulin Resistant Obesity? Curr Obes Rep 2014; 3:248-55. [PMID: 24891985 PMCID: PMC4039173 DOI: 10.1007/s13679-014-0095-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Although a correlation exists between obesity and insulin resistance, roughly 25 % of obese individuals are insulin sensitive. AMP-activated protein kinase (AMPK) is a cellular energy sensor that among its many actions, integrates diverse physiological signals to restore energy balance. In addition, in many situations it also increases insulin sensitivity. In this context, AMPK activity is decreased in very obese individuals undergoing bariatric surgery who are insulin resistant compared to equally obese patients who are insulin sensitive. In this review, we will both explore what distinguishes these individuals, and evaluate the evidence that diminished AMPK is associated with insulin resistance and metabolic syndrome-associated disorders in other circumstances.
Collapse
|
93
|
Lan F, Misu H, Chikamoto K, Takayama H, Kikuchi A, Mohri K, Takata N, Hayashi H, Matsuzawa-Nagata N, Takeshita Y, Noda H, Matsumoto Y, Ota T, Nagano T, Nakagen M, Miyamoto KI, Takatsuki K, Seo T, Iwayama K, Tokuyama K, Matsugo S, Tang H, Saito Y, Yamagoe S, Kaneko S, Takamura T. LECT2 functions as a hepatokine that links obesity to skeletal muscle insulin resistance. Diabetes 2014; 63:1649-64. [PMID: 24478397 DOI: 10.2337/db13-0728] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Recent articles have reported an association between fatty liver disease and systemic insulin resistance in humans, but the causal relationship remains unclear. The liver may contribute to muscle insulin resistance by releasing secretory proteins called hepatokines. Here we demonstrate that leukocyte cell-derived chemotaxin 2 (LECT2), an energy-sensing hepatokine, is a link between obesity and skeletal muscle insulin resistance. Circulating LECT2 positively correlated with the severity of both obesity and insulin resistance in humans. LECT2 expression was negatively regulated by starvation-sensing kinase adenosine monophosphate-activated protein kinase in H4IIEC hepatocytes. Genetic deletion of LECT2 in mice increased insulin sensitivity in the skeletal muscle. Treatment with recombinant LECT2 protein impaired insulin signaling via phosphorylation of Jun NH2-terminal kinase in C2C12 myocytes. These results demonstrate the involvement of LECT2 in glucose metabolism and suggest that LECT2 may be a therapeutic target for obesity-associated insulin resistance.
Collapse
Affiliation(s)
- Fei Lan
- Department of Disease Control and Homeostasis, Kanazawa University Graduate School of Medical Sciences, Kanazawa, Ishikawa, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
94
|
Laflamme C, Bertheau-Mailhot G, Giambelluca MS, Cloutier N, Boilard E, Pouliot M. Evidence of impairment of normal inflammatory reaction by a high-fat diet. Genes Immun 2014; 15:224-32. [DOI: 10.1038/gene.2014.8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Revised: 01/14/2014] [Accepted: 01/21/2014] [Indexed: 01/18/2023]
|
95
|
Rajpal DK, Qu XA, Freudenberg JM, Kumar VD. Mining emerging biomedical literature for understanding disease associations in drug discovery. Methods Mol Biol 2014; 1159:171-206. [PMID: 24788268 DOI: 10.1007/978-1-4939-0709-0_11] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Systematically evaluating the exponentially growing body of scientific literature has become a critical task that every drug discovery organization must engage in in order to understand emerging trends for scientific investment and strategy development. Developing trends analysis uses the number of publications within a 3-year window to determine concepts derived from well-established disease and gene ontologies to aid in recognizing and predicting emerging areas of scientific discoveries relevant to that space. In this chapter, we describe such a method and use obesity and psoriasis as use-case examples by analyzing the frequency of disease-related MeSH terms in PubMed abstracts over time. We share how our system can be used to predict emerging trends at a relatively early stage and we analyze the literature-identified genes for genetic associations, druggability, and biological pathways to explore any potential biological connections between the two diseases that could be utilized for drug discovery.
Collapse
Affiliation(s)
- Deepak K Rajpal
- Computational Biology, GlaxoSmithKline R&D, Research Triangle Park, North Carolina, NC, USA
| | | | | | | |
Collapse
|
96
|
Gaccioli F, White V, Capobianco E, Powell TL, Jawerbaum A, Jansson T. Maternal overweight induced by a diet with high content of saturated fat activates placental mTOR and eIF2alpha signaling and increases fetal growth in rats. Biol Reprod 2013; 89:96. [PMID: 24006279 DOI: 10.1095/biolreprod.113.109702] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
The mammalian target of rapamycin (mTOR) and the eukaryotic initiation factor 2 (eIF2) signaling pathways control protein synthesis in response to nutrient availability. Moreover, mTOR is a positive regulator of placental nutrient transport and is involved in the regulation of fetal growth. We hypothesized that maternal overweight, induced by a diet with high saturated fat content, i) up-regulates placental mTOR activity and nutrient transport, resulting in fetal overgrowth; ii) inhibits phosphorylation of eIF2 at its alpha subunit (eIF2alpha); and iii) leads to placental inflammation. Albino Wistar female rats were fed a control or high-saturated-fat (HF) diet for 7 wk before mating and during pregnancy. At gestational day 21, the HF diet significantly increased maternal and fetal triglyceride, leptin, and insulin (but not glucose) levels and maternal and fetal weights, and placental weights trended to increase. Phosphorylated 4EBP1 (T37/46 and S65) was significantly higher, and phosphorylated rpS6 (S235/236) tended to increase, in the placentas of dams fed an HF diet, indicating an activation of mTOR complex 1 (mTORC1). Phosphorylation of AMPK and eIF2alpha was reduced in the HF diet group compared to the control. The expression and activity of placental nutrient transporters and lipoprotein lipase (LPL), as well as the activation of inflammatory pathways, were not altered by the maternal diet. We conclude that maternal overweight induced by an HF diet stimulates mTORC1 activity and decreases eIF2alpha phosphorylation in rat placentas. We speculate that these changes may up-regulate protein synthesis and contribute to placental and fetal overgrowth.
Collapse
Affiliation(s)
- Francesca Gaccioli
- Center for Pregnancy and Newborn Research, University of Texas Health Science Center, San Antonio, Texas
| | | | | | | | | | | |
Collapse
|
97
|
Abstract
In most humans, obesity is associated with a chronic low-grade inflammatory reaction occurring in several organ tissues, including the adipose tissue. Infiltration of bone marrow derived leukocytes (granulocytes, monocytes, lymphocytes) into expanding adipose depots appears to be an integral component of inflammation in obesity. Circulating leukocytes invade organ tissues mainly through post-capillary venules in the microcirculation. The endothelium of the post-capillary venules acts as a gatekeeper to leukocyte adhesion and extravasation by displacing on its luminal surface adhesion molecules that bind the adhesive receptors expressed on circulating leukocytes. Several studies investigating the impact of obesity on the microcirculation have demonstrated the occurrence of microvascular dysfunction in experimental animal model of obesity, as well as in obese humans. To date though, working hypotheses and study designs have favored the view that microvascular alterations are secondary to adipose tissue dysfunction. Indeed, a significant amount of data exists in the scientific literature to support the concept that microvascular dysfunction may precede and cause adipose tissue inflammation in obesity. Through review of key published data, this article prospectively presents the concept that in response to nutrients overload the vascular endothelium of the microcirculation acutely activates inflammatory pathways that initiate infiltration of leukocytes in visceral adipose tissue, well before weight gain and overt obesity. The anatomical and physiological heterogeneity of different microcirculations is also discussed toward the understanding of how obesity induces different inflammatory phenotypes in visceral and subcutaneous fat depots.
Collapse
Affiliation(s)
- Rosario Scalia
- Department of Physiology and Cardiovascular Research Center, Temple University, Philadelphia, PA 19140, USA.
| |
Collapse
|