51
|
Wu Y, Pan Q, Yan H, Zhang K, Guo X, Xu Z, Yang W, Qi Y, Guo CA, Hornsby C, Zhang L, Zhou A, Li L, Chen Y, Zhang W, Sun Y, Zheng H, Wondisford F, He L, Guo S. Novel Mechanism of Foxo1 Phosphorylation in Glucagon Signaling in Control of Glucose Homeostasis. Diabetes 2018; 67:2167-2182. [PMID: 30201683 PMCID: PMC6198346 DOI: 10.2337/db18-0674] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 08/21/2018] [Indexed: 12/19/2022]
Abstract
Dysregulation of hepatic glucose production (HGP) serves as a major underlying mechanism for the pathogenesis of type 2 diabetes. The pancreatic hormone glucagon increases and insulin suppresses HGP, controlling blood glucose homeostasis. The forkhead transcription factor Foxo1 promotes HGP through increasing expression of genes encoding the rate-limiting enzymes responsible for gluconeogenesis. We previously established that insulin suppresses Foxo1 by Akt-mediated phosphorylation of Foxo1 at Ser256 in human hepatocytes. In this study, we found a novel Foxo1 regulatory mechanism by glucagon, which promotes Foxo1 nuclear translocation and stability via cAMP- and protein kinase A-dependent phosphorylation of Foxo1 at Ser276 Replacing Foxo1-S276 with alanine (A) or aspartate (D) to block or mimic phosphorylation, respectively, markedly regulates Foxo1 stability and nuclear localization in human hepatocytes. To establish in vivo function of Foxo1-Ser276 phosphorylation in glucose metabolism, we generated Foxo1-S273A and Foxo1-S273D knock-in (KI) mice. The KI mice displayed impaired blood glucose homeostasis, as well as the basal and glucagon-mediated HGP in hepatocytes. Thus, Foxo1-Ser276 is a new target site identified in the control of Foxo1 bioactivity and associated metabolic diseases.
Collapse
Affiliation(s)
- Yuxin Wu
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX
| | - Quan Pan
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX
| | - Hui Yan
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX
| | - Kebin Zhang
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX
| | - Xiaoqin Guo
- Department of Endocrinology, Third Military Medical University, Chongqing, China
- Division of Endocrinology, Department of Medicine, Johns Hopkins University, Baltimore, MD
| | - Zihui Xu
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX
| | - Wanbao Yang
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX
| | - Yajuan Qi
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX
| | - Cathy A Guo
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX
| | - Caitlyn Hornsby
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX
| | - Lin Zhang
- Department of Chemistry, Cleveland State University, Cleveland, OH
| | - Aimin Zhou
- Department of Chemistry, Cleveland State University, Cleveland, OH
| | - Ling Li
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX
| | - Yunmei Chen
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX
| | - Weiping Zhang
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX
| | - Yuxiang Sun
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX
| | - Hongting Zheng
- Department of Endocrinology, Third Military Medical University, Chongqing, China
| | - Fred Wondisford
- Division of Endocrinology, Department of Medicine, Johns Hopkins University, Baltimore, MD
| | - Ling He
- Division of Endocrinology, Department of Medicine, Johns Hopkins University, Baltimore, MD
| | - Shaodong Guo
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX
| |
Collapse
|
52
|
Nuclear trapping of inactive FOXO1 by the Nrf2 activator diethyl maleate. Redox Biol 2018; 20:19-27. [PMID: 30261343 PMCID: PMC6156746 DOI: 10.1016/j.redox.2018.09.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 09/13/2018] [Indexed: 12/18/2022] Open
Abstract
Diethyl maleate (DEM), a thiol-reactive α,β-unsaturated carbonyl compound, depletes glutathione (GSH) in exposed cells and was previously shown by us to elicit a stress response in Caenorhabditis elegans that, at lower concentrations, results in enhanced stress resistance and longer lifespan. This hormetic response was mediated through both the Nrf2 ortholog, SKN-1, and the forkhead box O (FOXO) family transcription factor DAF-16. As FOXO signaling is evolutionarily conserved, we analyzed here the effects of DEM exposure on FOXO in cultured human cells (HepG2, HEK293). DEM elicited nuclear accumulation of GFP-coupled wild-type human FOXO1, as well as of a cysteine-deficient FOXO1 mutant. Despite the nuclear accumulation of FOXO1, neither FOXO1 DNA binding nor FOXO target gene expression were stimulated, suggesting that DEM causes nuclear accumulation but not activation of FOXO1. FOXO1 nuclear exclusion elicited by insulin or xenobiotics such as arsenite or copper ions was attenuated by DEM, suggesting that DEM interfered with nuclear export. In addition, insulin-induced FOXO1 phosphorylation at Thr-24, which is associated with FOXO1 nuclear exclusion, was attenuated upon exposure to DEM. Different from FOXO-dependent expression of genes, Nrf2 target gene mRNAs were elevated upon exposure to DEM. These data suggest that, different from C. elegans, DEM elicits opposing effects on the two stress-responsive transcription factors, Nrf2 and FOXO1, in cultured human cells. Diethyl maleate (DEM) causes FOXO1 nuclear accumulation in HepG2 or HEK293 cells. DEM also elicits nuclear accumulation of the FOXO-ortholog, DAF-16, in C. elegans. Nevertheless, DEM does not elicit expression of FOXO, but of Nrf2 target genes. Insulin-induced FOXO1 phosphorylation and nuclear exclusion are attenuated by DEM. Nuclear accumulation of FOXO1 is due to interference with nuclear export machinery.
Collapse
|
53
|
Huang X, Liu G, Guo J, Su Z. The PI3K/AKT pathway in obesity and type 2 diabetes. Int J Biol Sci 2018; 14:1483-1496. [PMID: 30263000 PMCID: PMC6158718 DOI: 10.7150/ijbs.27173] [Citation(s) in RCA: 830] [Impact Index Per Article: 138.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 07/10/2018] [Indexed: 02/06/2023] Open
Abstract
Obesity and type 2 diabetes mellitus are complicated metabolic diseases that affect multiple organs and are characterized by hyperglycaemia. Currently, stable and effective treatments for obesity and type 2 diabetes mellitus are not available. Therefore, the mechanisms leading to obesity and diabetes and more effective ways to treat obesity and diabetes should be identified. Based on accumulated evidences, the PI3K/AKT signalling pathway is required for normal metabolism due to its characteristics, and its imbalance leads to the development of obesity and type 2 diabetes mellitus. This review focuses on the role of PI3K/AKT signalling in the skeletal muscle, adipose tissue, liver, brain and pancreas, and discusses how this signalling pathway affects the development of the aforementioned diseases. We also summarize evidences for recently identified therapeutic targets of the PI3K/AKT pathway as treatments for obesity and type 2 diabetes mellitus. PI3K/AKT pathway damaged in various tissues of the body leads to obesity and type 2 diabetes as the result of insulin resistance, and in turn, insulin resistance exacerbates the PI3K/AKT pathway, forming a vicious circle.
Collapse
Affiliation(s)
- Xingjun Huang
- Guangdong Engineering Research Center of Natural Products and New Drugs, Guangdong Provincial University Engineering Technology Research Center of Natural Products and Drugs, Guangdong Pharmaceutical University, Guangzhou (510006), China.,Guangdong Metabolic Diseases Research Center of Integrated Chinese and Western Medicine, Guangdong Pharmaceutical University, Guangzhou (510006), China
| | - Guihua Liu
- Shenzhen Center for Disease Control and Prevention, 8 Longyuan Road, Nanshan District, Shenzhen (518055), China
| | - Jiao Guo
- Guangdong Metabolic Diseases Research Center of Integrated Chinese and Western Medicine, Guangdong Pharmaceutical University, Guangzhou (510006), China
| | - Zhengquan Su
- Guangdong Engineering Research Center of Natural Products and New Drugs, Guangdong Provincial University Engineering Technology Research Center of Natural Products and Drugs, Guangdong Pharmaceutical University, Guangzhou (510006), China.,Guangdong Metabolic Diseases Research Center of Integrated Chinese and Western Medicine, Guangdong Pharmaceutical University, Guangzhou (510006), China
| |
Collapse
|
54
|
Abstract
FOXO transcription factors are evolutionally conserved regulators of organismal life span downstream of insulin signaling. After integrating cellular signals from various stimuli such as growth factors, oxidative stress, and energy deprivation, FOXO factors induce expression of a specific set of genes that regulate various cellular processes to maintain homeostasis at a cellular or organismal level. In this review, we discuss roles of FOXO proteins in the maintenance of mitochondria, organelles critical for cellular quality control. FOXO factors protect mitochondria by activating mitochondrial antioxidant enzymes and they help remodel damaged mitochondria by inducing remodeling processes such as mitophagy. Furthermore, we also review the recently identified FOXO-dependent retrograde signaling from stressed mitochondria to the nucleus, which suggest that FOXO mediates the crosstalk between these two important organelles to maintain cell homeostasis. In addition, we introduce a mitohormetic role of gamitrinib-triphenylphosphonium (G-TPP), a mitochondrial heat shock protein (Hsp) inhibitor that can induce mild mitochondrial stress to protect cells from future insults in a FOXO-dependent manner.
Collapse
|
55
|
Yarushkin AA, Mazin ME, Yunusova AY, Korchagina KV, Pustylnyak YA, Prokopyeva EA, Pustylnyak VO. CAR-mediated repression of Cdkn1a(p21) is accompanied by the Akt activation. Biochem Biophys Res Commun 2018; 504:361-366. [PMID: 29890134 DOI: 10.1016/j.bbrc.2018.06.032] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 06/08/2018] [Indexed: 11/25/2022]
Abstract
It was shown that CAR participates in the regulation of many cell processes. Thus, the activation of CAR causes a proliferating effect in the liver, which provides grounds to consider CAR as a therapeutic target when having a partial resection of this organ. Even though a lot of work has been done on the function of CAR in regulating hepatocyte proliferation, very little has been done on its complex mediating mechanism. This study, therefore, showed that the liver growth resulting from CAR activation leads to the decline in the level of PTEN protein and subsequent Akt activation in mouse liver. The increase of Akt activation produced by CAR agonist was accompanied by a decrease in the level of Foxo1, which was correlated with decreased expression of Foxo1 target genes, including Cdkn1a(p21). Moreover, the study also demonstrated that there exists a negative regulatory impact of CAR on the relationship between Foxo1 and targeted Cdkn1a(p21) promoter. Therefore, the study results revealed an essential function of CAR-Akt-Foxo1 signalling pathway in controlling hepatocyte proliferation by repressing the cell cycle regulator Cdkn1a (p21).
Collapse
Affiliation(s)
- Andrei A Yarushkin
- Novosibirsk State University, Novosibirsk, Pirogova Street, 1, 630090, Russia; Federal Research Center of Fundamental and Translational Medicine, Novosibirsk, Timakova Street, 2/12, 630117, Russia
| | - Mark E Mazin
- Novosibirsk State University, Novosibirsk, Pirogova Street, 1, 630090, Russia
| | - Anastasia Y Yunusova
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 8 Lavrentjev Avenue, 630090, Russia
| | - Kseniya V Korchagina
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 8 Lavrentjev Avenue, 630090, Russia
| | - Yuliya A Pustylnyak
- Novosibirsk State University, Novosibirsk, Pirogova Street, 1, 630090, Russia
| | - Elena A Prokopyeva
- Novosibirsk State University, Novosibirsk, Pirogova Street, 1, 630090, Russia; Federal Research Center of Fundamental and Translational Medicine, Novosibirsk, Timakova Street, 2/12, 630117, Russia
| | - Vladimir O Pustylnyak
- Novosibirsk State University, Novosibirsk, Pirogova Street, 1, 630090, Russia; Federal Research Center of Fundamental and Translational Medicine, Novosibirsk, Timakova Street, 2/12, 630117, Russia.
| |
Collapse
|
56
|
Cross-talk among HMGA1 and FoxO1 in control of nuclear insulin signaling. Sci Rep 2018; 8:8540. [PMID: 29867121 PMCID: PMC5986867 DOI: 10.1038/s41598-018-26968-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 05/21/2018] [Indexed: 12/27/2022] Open
Abstract
As a mediator of insulin-regulated gene expression, the FoxO1 transcription factor represents a master regulator of liver glucose metabolism. We previously reported that the high-mobility group AT-hook 1 (HMGA1) protein, a molecular switch for the insulin receptor gene, functions also as a downstream target of the insulin receptor signaling pathway, representing a critical nuclear mediator of insulin function. Here, we investigated whether a functional relationship existed between FoxO1 and HMGA1, which might help explain insulin-mediated gene transcription in the liver. To this end, as a model study, we investigated the canonical FoxO1-HMGA1-responsive IGFBP1 gene, whose hepatic expression is regulated by insulin. By using a conventional GST-pull down assay combined with co-immunoprecipitation and Fluorescence Resonance Energy Transfer (FRET) analyses, we provide evidence of a physical interaction between FoxO1 and HMGA1. Further investigation with chromatin immunoprecipitation, confocal microscopy, and Fluorescence Recovery After Photobleaching (FRAP) technology indicated a functional significance of this interaction, in both basal and insulin-stimulated states, providing evidence that, by modulating FoxO1 transactivation, HMGA1 is essential for FoxO1-induced IGFBP1 gene expression, and thereby a critical modulator of insulin-mediated FoxO1 regulation in the liver. Collectively, our findings highlight a novel FoxO1/HMGA1-mediated mechanism by which insulin may regulate gene expression and metabolism.
Collapse
|
57
|
Varghese J, James J, Vaulont S, Mckie A, Jacob M. Increased intracellular iron in mouse primary hepatocytes in vitro causes activation of the Akt pathway but decreases its response to insulin. Biochim Biophys Acta Gen Subj 2018; 1862:1870-1882. [PMID: 29859963 DOI: 10.1016/j.bbagen.2018.05.022] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 05/17/2018] [Accepted: 05/28/2018] [Indexed: 02/06/2023]
Abstract
BACKGROUND An iron-overloaded state has been reported to be associated with insulin resistance. On the other hand, conditions such as classical hemochromatosis (where iron overload occurs primarily in the liver) have been reported to be associated with increased insulin sensitivity. The reasons for these contradictory findings are unclear. In this context, the effects of increased intracellular iron per se on insulin signaling in hepatocytes are not known. METHODS Mouse primary hepatocytes were loaded with iron in vitro by incubation with ferric ammonium citrate (FAC). Intracellular events related to insulin signaling, as well as changes in gene expression and hepatocyte glucose production (HGP), were studied in the presence and absence of insulin and/or forskolin (a glucagon mimetic). RESULTS In vitro iron-loading of hepatocytes resulted in phosphorylation-mediated activation of Akt and AMP-activated protein kinase. This was associated with decreased basal and forskolin-stimulated HGP. Iron attenuated forskolin-mediated induction of the key gluconeogenic enzyme, glucose-6-phosphatase. It also attenuated activation of the Akt pathway in response to insulin, which was associated with decreased protein levels of insulin receptor substrates 1 and 2, constituting insulin resistance. CONCLUSIONS Increased intracellular iron has dual effects on insulin sensitivity in hepatocytes. It increased basal activation of the Akt pathway, but decreased activation of this pathway in response to insulin. GENERAL SIGNIFICANCE These findings may help explain why both insulin resistance and increased sensitivity have been observed in iron-overloaded states. They are of relevance to a variety of disease conditions characterized by hepatic iron overload and increased risk of diabetes.
Collapse
Affiliation(s)
- Joe Varghese
- Department of Biochemistry, Christian Medical College, Vellore 632002, India(1).
| | - Jithu James
- Department of Biochemistry, Christian Medical College, Vellore 632002, India(1)
| | | | - Andrew Mckie
- Diabetes and Nutritional Sciences Division, School of Medicine, King's College, London, UK
| | - Molly Jacob
- Department of Biochemistry, Christian Medical College, Vellore 632002, India(1)
| |
Collapse
|
58
|
Drosophila melanogaster as a Model for Diabetes Type 2 Progression. BIOMED RESEARCH INTERNATIONAL 2018; 2018:1417528. [PMID: 29854726 PMCID: PMC5941822 DOI: 10.1155/2018/1417528] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 02/03/2018] [Accepted: 03/13/2018] [Indexed: 12/12/2022]
Abstract
Drosophila melanogaster has been used as a very versatile and potent model in the past few years for studies in metabolism and metabolic disorders, including diabetes types 1 and 2. Drosophila insulin signaling, despite having seven insulin-like peptides with partially redundant functions, is very similar to the human insulin pathway and has served to study many different aspects of diabetes and the diabetic state. Yet, very few studies have addressed the chronic nature of diabetes, key for understanding the full-blown disease, which most studies normally explore. One of the advantages of having Drosophila mutant viable combinations at different levels of the insulin pathway, with significantly reduced insulin pathway signaling, is that the abnormal metabolic state can be studied from the onset of the life cycle and followed throughout. In this review, we look at the chronic nature of impaired insulin signaling. We also compare these results to the results gleaned from vertebrate model studies.
Collapse
|
59
|
Tsitsipatis D, Gopal K, Steinbrenner H, Klotz LO. FOXO1 cysteine-612 mediates stimulatory effects of the coregulators CBP and PGC1α on FOXO1 basal transcriptional activity. Free Radic Biol Med 2018; 118:98-107. [PMID: 29496617 DOI: 10.1016/j.freeradbiomed.2018.02.034] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 02/17/2018] [Accepted: 02/24/2018] [Indexed: 11/15/2022]
Abstract
Hepatic production and release of metabolites, nutrients and micronutrient transporters is tightly regulated at the level of gene expression. In this regard, transcription factor FOXO1 modulates the expression of genes such as G6PC and SELENOP, encoding the catalytic subunit of glucose 6-phosphatase and the plasma selenium transporter selenoprotein P, respectively. Here, we analyzed the role of cysteine residues in FOXO1 in controlling its activity with respect to regulation of G6PC and SELENOP in HepG2 human hepatoma cells. None of the seven FOXO1 cysteines affected FOXO1 binding to DNA or its basal subcellular distribution. Whereas overexpression of wildtype FOXO1 caused a strong induction of both G6PC and SELENOP promoter activities and mRNA levels, the induction was lowered by approx. 50% if cysteine-deficient FOXO1 was overexpressed instead. Only the most C-terminal of the seven FOXO1 cysteines, Cys612, was required and sufficient to ensure full FOXO1 transactivation activity. Coexpression of FOXO1 coregulators, CBP or PGC1α, had a strong synergistic effect in stimulating G6PC promoter activity and expression, fully relying on the presence of FOXO1 Cys612. Similarly, a synergistic effect of FOXO1 and CBP was observed for SELENOP. In contrast, stimulation of SELENOP by PGC1α was independent of FOXO1-Cys612, due to the close proximity of a hepatocyte nuclear factor-4α binding site to the FOXO1 binding site within the SELENOP promoter, as demonstrated using mutant SELENOP promoter constructs. In summary, full basal FOXO1 transactivation activity relies on Cys612, which mediates synergistic effects of coregulators, CBP or PGC1α, on FOXO1 transcriptional activity. The extent of Cys612 contribution depends on the promoter context of FOXO1 target genes.
Collapse
Affiliation(s)
- Dimitrios Tsitsipatis
- Institute of Nutrition, Department of Nutrigenomics, Friedrich-Schiller-Universität Jena, D-07743 Jena, Germany
| | - Keshav Gopal
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada
| | - Holger Steinbrenner
- Institute of Nutrition, Department of Nutrigenomics, Friedrich-Schiller-Universität Jena, D-07743 Jena, Germany
| | - Lars-Oliver Klotz
- Institute of Nutrition, Department of Nutrigenomics, Friedrich-Schiller-Universität Jena, D-07743 Jena, Germany; Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada.
| |
Collapse
|
60
|
Unterman TG. Regulation of Hepatic Glucose Metabolism by FoxO Proteins, an Integrated Approach. Curr Top Dev Biol 2018; 127:119-147. [DOI: 10.1016/bs.ctdb.2017.10.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
61
|
Cao J, Yu Y, Zhang Z, Chen X, Hu Z, Tong Q, Chang J, Feng XH, Lin X. SCP4 Promotes Gluconeogenesis Through FoxO1/3a Dephosphorylation. Diabetes 2018; 67:46-57. [PMID: 28851713 PMCID: PMC5741142 DOI: 10.2337/db17-0546] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 08/21/2017] [Indexed: 11/13/2022]
Abstract
FoxO1 and FoxO3a (collectively FoxO1/3a) proteins regulate a wide array of cellular processes, including hepatic gluconeogenesis. Phosphorylation of FoxO1/3a is a key event that determines its subcellular location and transcriptional activity. During glucose synthesis, the activity of FoxO1/3a is negatively regulated by Akt-mediated phosphorylation, which leads to the cytoplasmic retention of FoxO1/3a. However, the nuclear phosphatase that directly regulates FoxO1/3a remains to be identified. In this study, we discovered a nuclear phosphatase, SCP4/CTDSPL2 (SCP4), that dephosphorylated FoxO1/3a and promoted FoxO1/3a transcription activity. We found that SCP4 enhanced the transcription of FoxO1/3a target genes encoding PEPCK1 and G6PC, key enzymes in hepatic gluconeogenesis. Ectopic expression of SCP4 increased, while knockdown of SCP4 inhibited, glucose production. Moreover, we demonstrated that gene ablation of SCP4 led to hypoglycemia in neonatal mice. Consistent with the positive role of SCP4 in gluconeogenesis, expression of SCP4 was regulated under pathophysiological conditions. SCP4 expression was induced by glucose deprivation in vitro and in vivo and was elevated in obese mice caused by genetic (Avy) and dietary (high-fat) changes. Thus, our findings provided experimental evidence that SCP4 regulates hepatic gluconeogenesis and could serve as a potential target for the prevention and treatment of diet-induced glucose intolerance and type 2 diabetes.
Collapse
Affiliation(s)
- Jin Cao
- Department of Molecular & Cellular Biology, Baylor College of Medicine, Houston, TX
| | - Yi Yu
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang, China
- Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, TX
| | - Zhengmao Zhang
- Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, TX
| | - Xi Chen
- Department of Molecular & Cellular Biology, Baylor College of Medicine, Houston, TX
| | - Zhaoyong Hu
- Department of Medicine, Baylor College of Medicine, Houston, TX
| | - Qiang Tong
- Children's Nutrition Research Center, Baylor College of Medicine, Houston, TX
| | - Jiang Chang
- Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, TX
| | - Xin-Hua Feng
- Department of Molecular & Cellular Biology, Baylor College of Medicine, Houston, TX
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang, China
- Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, TX
| | - Xia Lin
- Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, TX
| |
Collapse
|
62
|
Hou T, Li Z, Zhao Y, Zhu WG. Mechanisms controlling the anti-neoplastic functions of FoxO proteins. Semin Cancer Biol 2017; 50:101-114. [PMID: 29155239 DOI: 10.1016/j.semcancer.2017.11.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 10/18/2017] [Accepted: 11/14/2017] [Indexed: 02/06/2023]
Abstract
The Forkhead box O (FoxO) proteins comprise a family of evolutionarily conserved transcription factors that predominantly function as tumor suppressors. These proteins assume diverse roles in the cellular anti-neoplastic response, including regulation of apoptosis and autophagy, cancer metabolism, cell-cycle arrest, oxidative stress and the DNA damage response. More recently, FoxO proteins have been implicated in cancer immunity and cancer stem-cell (CSC) homeostasis. Interestingly, in some sporadic sub-populations, FoxO protein function may also be manipulated by factors such as β-catenin whereby they instead can facilitate cancer progression via maintenance of CSC properties or promoting drug resistance or metastasis and invasion. This review highlights the essential biological functions of FoxOs and explores the areas that may be exploited in FoxO protein signaling pathways in the development of novel cancer therapeutic agents.
Collapse
Affiliation(s)
- Tianyun Hou
- Guangdong Key Laboratory of Genome Stability and Human Disease Prevention, Department of Biochemistry and Molecular Biology, School of Medicine, Shenzhen University, Shenzhen 518060, China; Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Zhiming Li
- Guangdong Key Laboratory of Genome Stability and Human Disease Prevention, Department of Biochemistry and Molecular Biology, School of Medicine, Shenzhen University, Shenzhen 518060, China; Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Ying Zhao
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Wei-Guo Zhu
- Guangdong Key Laboratory of Genome Stability and Human Disease Prevention, Department of Biochemistry and Molecular Biology, School of Medicine, Shenzhen University, Shenzhen 518060, China; Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China.
| |
Collapse
|
63
|
Identification of the principal transcriptional regulators for low-fat and high-fat meal responsive genes in small intestine. Nutr Metab (Lond) 2017; 14:66. [PMID: 29075307 PMCID: PMC5654052 DOI: 10.1186/s12986-017-0221-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 10/16/2017] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND High-fat (HF) diet is a well-known cause of obesity. To identify principle transcriptional regulators that could be therapeutic targets of obesity, we investigated transcriptomic modulation in the duodenal mucosa following low-fat (LF) and HF meal ingestion. METHODS Whereas one group of mice was sacrificed after fasting, the others were fed ad libitum with LF or HF meal, and sacrificed 30 min, 1 h and 3 h after the beginning of the meal. A transcriptome analysis of the duodenal mucosa of the 7 groups was conducted using both microarray and serial analysis of gene expression (SAGE) method followed by an Ingenuity Pathways Analysis (IPA). RESULTS SAGE and microarray showed that the modulation of a total of 896 transcripts in the duodenal mucosa after LF and/or HF meal, compared to the fasting condition. The IPA identified lipid metabolism, molecular transport, and small molecule biochemistry as top three molecular and cellular functions for the HF-responsive, HF-specific, HF-delay, and LF-HF different genes. Moreover, the top transcriptional regulator for the HF-responsive and HF-specific genes was peroxisome proliferator-activated receptor alpha (PPARα). On the other hand, the LF-responsive and LF-specific genes were related to carbohydrate metabolism, cellular function and maintenance, and cell death/cellular growth and proliferation, and the top transcriptional regulators were forkhead box protein O1 (FOXO1) and cAMP response element binding protein 1 (CREB1), respectively. CONCLUSIONS These results will help to understand the molecular mechanisms of intestinal response after LF and HF ingestions, and contribute to identify therapeutic targets for obesity and obesity-related diseases.
Collapse
|
64
|
Abstract
The liver is crucial for the maintenance of normal glucose homeostasis - it produces glucose during fasting and stores glucose postprandially. However, these hepatic processes are dysregulated in type 1 and type 2 diabetes mellitus, and this imbalance contributes to hyperglycaemia in the fasted and postprandial states. Net hepatic glucose production is the summation of glucose fluxes from gluconeogenesis, glycogenolysis, glycogen synthesis, glycolysis and other pathways. In this Review, we discuss the in vivo regulation of these hepatic glucose fluxes. In particular, we highlight the importance of indirect (extrahepatic) control of hepatic gluconeogenesis and direct (hepatic) control of hepatic glycogen metabolism. We also propose a mechanism for the progression of subclinical hepatic insulin resistance to overt fasting hyperglycaemia in type 2 diabetes mellitus. Insights into the control of hepatic gluconeogenesis by metformin and insulin and into the role of lipid-induced hepatic insulin resistance in modifying gluconeogenic and net hepatic glycogen synthetic flux are also discussed. Finally, we consider the therapeutic potential of strategies that target hepatosteatosis, hyperglucagonaemia and adipose lipolysis.
Collapse
Affiliation(s)
- Max C Petersen
- Department of Internal Medicine, Yale School of Medicine
- Department of Cellular &Molecular Physiology, Yale School of Medicine
| | | | - Gerald I Shulman
- Department of Internal Medicine, Yale School of Medicine
- Department of Cellular &Molecular Physiology, Yale School of Medicine
- Howard Hughes Medical Institute, Yale School of Medicine, New Haven, Connecticut 06520, USA
| |
Collapse
|
65
|
Wang T, Jiang H, Cao S, Chen Q, Cui M, Wang Z, Li D, Zhou J, Wang T, Qiu F, Kang N. Baicalin and its metabolites suppresses gluconeogenesis through activation of AMPK or AKT in insulin resistant HepG-2 cells. Eur J Med Chem 2017; 141:92-100. [PMID: 29028535 DOI: 10.1016/j.ejmech.2017.09.049] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Revised: 09/21/2017] [Accepted: 09/22/2017] [Indexed: 12/20/2022]
Abstract
Scutellaria baicalensis Georgi (S. baicalensis), as a traditional Chinese herbal medicine, is an important component of several famous Chinese medicinal formulas for treating patients with diabetes mellitus. Baicalin (BG), a main bioactive component of S. baicalensis, has been reported to have antidiabetic effects. However, pharmacokinetic studies have indicated that BG has poor oral bioavailability. Therefore, it is hard to explain the pharmacological effects of BG in vivo. Interestingly, several reports show that BG is extensively metabolized in rats and humans. Therefore, we speculate that the BG metabolites might be responsible for the pharmacological effects. In this study, BG and its three metabolites (M1-M3) were examined their effects on glucose consumption in insulin resistant HepG-2 cells with a commercial glucose assay kit. Real-time PCR and western blot assay were used to confirm genes and proteins of interest, respectively. The results demonstrate that BG and its metabolites (except for M3) enhanced the glucose consumption which might be associated with inhibiting the expression of the key gluconeogenic genes, including glucose-6-phosphatase (G6Pase), phosphoenolypyruvate carboxykinase (PEPCK) and glucose transporter 2 (GLUT2). Further study found that BG and M1 could suppress hepatic gluconeogenesis via activation of the AMPK pathway, while M2 could suppress hepatic gluconeogenesis via activation of the PI3K/AKT signaling pathway. Taken together, our findings suggest that both BG and its metabolites have antihyperglycemic activities, and might be the active forms of oral doses of BG in vivo.
Collapse
Affiliation(s)
- Tao Wang
- School of Integrative Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, People's Republic of China
| | - Hongmei Jiang
- School of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, People's Republic of China; Department of Natural Products Chemistry, School of Traditional Chinese Materia Medica, Shenyang Pharmaceutical University, Shenyang, 110016, People's Republic of China
| | - Shijie Cao
- Tianjin State Key Laboratory of Modern Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, People's Republic of China
| | - Qian Chen
- School of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, People's Republic of China; Tianjin State Key Laboratory of Modern Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, People's Republic of China
| | - Mingyuan Cui
- School of Integrative Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, People's Republic of China
| | - Zhijie Wang
- School of Integrative Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, People's Republic of China
| | - Dandan Li
- School of Integrative Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, People's Republic of China
| | - Jing Zhou
- School of Integrative Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, People's Republic of China
| | - Tao Wang
- Tianjin State Key Laboratory of Modern Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, People's Republic of China
| | - Feng Qiu
- School of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, People's Republic of China; Department of Natural Products Chemistry, School of Traditional Chinese Materia Medica, Shenyang Pharmaceutical University, Shenyang, 110016, People's Republic of China.
| | - Ning Kang
- School of Integrative Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, People's Republic of China.
| |
Collapse
|
66
|
Hatting M, Tavares CDJ, Sharabi K, Rines AK, Puigserver P. Insulin regulation of gluconeogenesis. Ann N Y Acad Sci 2017; 1411:21-35. [PMID: 28868790 DOI: 10.1111/nyas.13435] [Citation(s) in RCA: 301] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 06/16/2017] [Accepted: 06/26/2017] [Indexed: 12/11/2022]
Abstract
The coordinated regulation between cellular glucose uptake and endogenous glucose production is indispensable for the maintenance of constant blood glucose concentrations. The liver contributes significantly to this process by altering the levels of hepatic glucose release, through controlling the processes of de novo glucose production (gluconeogenesis) and glycogen breakdown (glycogenolysis). Various nutritional and hormonal stimuli signal to alter hepatic gluconeogenic flux, and suppression of this metabolic pathway during the postprandial state can, to a significant extent, be attributed to insulin. Here, we review some of the molecular mechanisms through which insulin modulates hepatic gluconeogenesis, thus controlling glucose production by the liver to ultimately maintain normoglycemia. Various signaling pathways governed by insulin converge at the level of transcriptional regulation of the key hepatic gluconeogenic genes PCK1 and G6PC, highlighting this as one of the focal mechanisms through which gluconeogenesis is modulated. In individuals with compromised insulin signaling, such as insulin resistance in type 2 diabetes, insulin fails to suppress hepatic gluconeogenesis, even in the fed state; hence, an insight into these insulin-moderated pathways is critical for therapeutic purposes.
Collapse
Affiliation(s)
- Maximilian Hatting
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts.,Department of Cell Biology, Harvard Medical School, Boston, Massachusetts
| | - Clint D J Tavares
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts.,Department of Cell Biology, Harvard Medical School, Boston, Massachusetts
| | - Kfir Sharabi
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts.,Department of Cell Biology, Harvard Medical School, Boston, Massachusetts
| | - Amy K Rines
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts.,Department of Cell Biology, Harvard Medical School, Boston, Massachusetts
| | - Pere Puigserver
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts.,Department of Cell Biology, Harvard Medical School, Boston, Massachusetts
| |
Collapse
|
67
|
Sasaki M, Sasako T, Kubota N, Sakurai Y, Takamoto I, Kubota T, Inagi R, Seki G, Goto M, Ueki K, Nangaku M, Jomori T, Kadowaki T. Dual Regulation of Gluconeogenesis by Insulin and Glucose in the Proximal Tubules of the Kidney. Diabetes 2017. [PMID: 28630133 DOI: 10.2337/db16-1602] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Growing attention has been focused on the roles of the proximal tubules (PTs) of the kidney in glucose metabolism, including the mechanism of regulation of gluconeogenesis. In this study, we found that PT-specific insulin receptor substrate 1/2 double-knockout mice, established by using the newly generated sodium-glucose cotransporter 2 (SGLT2)-Cre transgenic mice, exhibited impaired insulin signaling and upregulated gluconeogenic gene expression and renal gluconeogenesis, resulting in systemic insulin resistance. In contrast, in streptozotocin-treated mice, although insulin action was impaired in the PTs, the gluconeogenic gene expression was unexpectedly downregulated in the renal cortex, which was restored by administration of an SGLT1/2 inhibitor. In the HK-2 cells, the gluconeogenic gene expression was suppressed by insulin, accompanied by phosphorylation and inactivation of forkhead box transcription factor 1 (FoxO1). In contrast, glucose deacetylated peroxisome proliferator-activated receptor γ coactivator 1-α (PGC1α), a coactivator of FoxO1, via sirtuin 1, suppressing the gluconeogenic gene expression, which was reversed by inhibition of glucose reabsorption. These data suggest that both insulin signaling and glucose reabsorption suppress the gluconeogenic gene expression by inactivation of FoxO1 and PGC1α, respectively, providing insight into novel mechanisms underlying the regulation of gluconeogenesis in the PTs.
Collapse
Affiliation(s)
- Motohiro Sasaki
- Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
- Mie Research Laboratories, Sanwa Kagaku Kenkyusho Co., Ltd., Mie, Japan
| | - Takayoshi Sasako
- Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
- Translational Systems Biology and Medicine Initiative, The University of Tokyo, Tokyo, Japan
- Department of Molecular Diabetic Medicine, Diabetes Research Center, National Center for Global Health and Medicine, Tokyo, Japan
| | - Naoto Kubota
- Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
- Translational Systems Biology and Medicine Initiative, The University of Tokyo, Tokyo, Japan
- Department of Clinical Nutrition Therapy, The University of Tokyo Hospital, The University of Tokyo, Tokyo, Japan
- Clinical Nutrition Program, National Institute of Health and Nutrition, Tokyo, Japan
- Laboratory for Metabolic Homeostasis, RIKEN Center for Integrative Medical Sciences, Kanagawa, Japan
| | - Yoshitaka Sakurai
- Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Iseki Takamoto
- Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Tetsuya Kubota
- Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
- Clinical Nutrition Program, National Institute of Health and Nutrition, Tokyo, Japan
- Laboratory for Metabolic Homeostasis, RIKEN Center for Integrative Medical Sciences, Kanagawa, Japan
- Division of Cardiovascular Medicine, Toho University Ohashi Medical Center, Tokyo, Japan
| | - Reiko Inagi
- Department of Nephrology and Endocrinology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | | | - Moritaka Goto
- Mie Research Laboratories, Sanwa Kagaku Kenkyusho Co., Ltd., Mie, Japan
| | - Kohjiro Ueki
- Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
- Translational Systems Biology and Medicine Initiative, The University of Tokyo, Tokyo, Japan
- Department of Molecular Diabetic Medicine, Diabetes Research Center, National Center for Global Health and Medicine, Tokyo, Japan
| | - Masaomi Nangaku
- Department of Nephrology and Endocrinology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Takahito Jomori
- Mie Research Laboratories, Sanwa Kagaku Kenkyusho Co., Ltd., Mie, Japan
| | - Takashi Kadowaki
- Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
- Translational Systems Biology and Medicine Initiative, The University of Tokyo, Tokyo, Japan
| |
Collapse
|
68
|
Nagarajan S, Bedi U, Budida A, Hamdan FH, Mishra VK, Najafova Z, Xie W, Alawi M, Indenbirken D, Knapp S, Chiang CM, Grundhoff A, Kari V, Scheel CH, Wegwitz F, Johnsen SA. BRD4 promotes p63 and GRHL3 expression downstream of FOXO in mammary epithelial cells. Nucleic Acids Res 2017; 45:3130-3145. [PMID: 27980063 PMCID: PMC5389510 DOI: 10.1093/nar/gkw1276] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2016] [Accepted: 12/09/2016] [Indexed: 12/12/2022] Open
Abstract
Bromodomain-containing protein 4 (BRD4) is a member of the bromo- and extraterminal (BET) domain-containing family of epigenetic readers which is under intensive investigation as a target for anti-tumor therapy. BRD4 plays a central role in promoting the expression of select subsets of genes including many driven by oncogenic transcription factors and signaling pathways. However, the role of BRD4 and the effects of BET inhibitors in non-transformed cells remain mostly unclear. We demonstrate that BRD4 is required for the maintenance of a basal epithelial phenotype by regulating the expression of epithelial-specific genes including TP63 and Grainy Head-like transcription factor-3 (GRHL3) in non-transformed basal-like mammary epithelial cells. Moreover, BRD4 occupancy correlates with enhancer activity and enhancer RNA (eRNA) transcription. Motif analyses of cell context-specific BRD4-enriched regions predicted the involvement of FOXO transcription factors. Consistently, activation of FOXO1 function via inhibition of EGFR-AKT signaling promoted the expression of TP63 and GRHL3. Moreover, activation of Src kinase signaling and FOXO1 inhibition decreased the expression of FOXO/BRD4 target genes. Together, our findings support a function for BRD4 in promoting basal mammary cell epithelial differentiation, at least in part, by regulating FOXO factor function on enhancers to activate TP63 and GRHL3 expression.
Collapse
Affiliation(s)
- Sankari Nagarajan
- Department of General, Visceral and Pediatric Surgery, Göttingen Center for Molecular Biosciences, University Medical Center Göttingen, 37077 Göttingen, Germany
| | - Upasana Bedi
- Institute of Molecular Oncology, University Medical Center Göttingen, 37077 Göttingen, Germany.,Institute of Tumor Biology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Anusha Budida
- Department of General, Visceral and Pediatric Surgery, Göttingen Center for Molecular Biosciences, University Medical Center Göttingen, 37077 Göttingen, Germany
| | - Feda H Hamdan
- Department of General, Visceral and Pediatric Surgery, Göttingen Center for Molecular Biosciences, University Medical Center Göttingen, 37077 Göttingen, Germany
| | - Vivek Kumar Mishra
- Department of General, Visceral and Pediatric Surgery, Göttingen Center for Molecular Biosciences, University Medical Center Göttingen, 37077 Göttingen, Germany
| | - Zeynab Najafova
- Department of General, Visceral and Pediatric Surgery, Göttingen Center for Molecular Biosciences, University Medical Center Göttingen, 37077 Göttingen, Germany
| | - Wanhua Xie
- Department of General, Visceral and Pediatric Surgery, Göttingen Center for Molecular Biosciences, University Medical Center Göttingen, 37077 Göttingen, Germany
| | - Malik Alawi
- Bioinformatics Core, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany.,Heinrich-Pette-Institute, Leibniz Institute for Experimental Virology, 20251 Hamburg, Germany
| | - Daniela Indenbirken
- Heinrich-Pette-Institute, Leibniz Institute for Experimental Virology, 20251 Hamburg, Germany
| | - Stefan Knapp
- Structural Genomics Consortium, University of Oxford, Oxford OX3 7DQ, UK.,Target Discovery Institute, University of Oxford, Oxford OX3 7FZ, UK.,Institute for Pharmaceutical Chemistry, Goethe University Frankfurt 60323, Germany
| | - Cheng-Ming Chiang
- University of Texas Southwestern Medical Center, Simmons Comprehensive Cancer Center, Dallas, TX 75235, USA
| | - Adam Grundhoff
- Heinrich-Pette-Institute, Leibniz Institute for Experimental Virology, 20251 Hamburg, Germany
| | - Vijayalakshmi Kari
- Department of General, Visceral and Pediatric Surgery, Göttingen Center for Molecular Biosciences, University Medical Center Göttingen, 37077 Göttingen, Germany
| | - Christina H Scheel
- Institute of Stem Cell Research, Helmholtz Center for Health and Environmental Research Munich, 85764 Neuherberg, Germany
| | - Florian Wegwitz
- Department of General, Visceral and Pediatric Surgery, Göttingen Center for Molecular Biosciences, University Medical Center Göttingen, 37077 Göttingen, Germany
| | - Steven A Johnsen
- Department of General, Visceral and Pediatric Surgery, Göttingen Center for Molecular Biosciences, University Medical Center Göttingen, 37077 Göttingen, Germany
| |
Collapse
|
69
|
Link W, Fernandez-Marcos PJ. FOXO transcription factors at the interface of metabolism and cancer. Int J Cancer 2017. [PMID: 28631330 DOI: 10.1002/ijc.30840] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Diabetes refers to a group of metabolic diseases characterized by impaired insulin signalling and high blood glucose. A growing body of epidemiological evidence links diabetes to several types of cancer but the underlying molecular mechanisms are poorly understood. The signalling cascade connecting insulin and FOXO proteins provides a compelling example for a conserved pathway at the interface between insulin signalling and cancer. FOXOs are transcription factors that orchestrate programs of gene expression known to control a variety of processes in response to cellular stress. Genes regulated by this family of proteins are involved in the regulation of cellular energy production, oxidative stress resistance and cell viability and proliferation. Accordingly, FOXO factors have been shown to play an important role in the suppression of tumour growth and in the regulation of metabolic homeostasis. There is emerging evidence that deregulation of FOXO factors might account for the association between insulin resistance-related metabolic disorders and cancer.
Collapse
Affiliation(s)
- Wolfgang Link
- Centre for Biomedical Research (CBMR), University of Algarve, Campus of Gambelas, Building 8, room 2.22, Faro, 8005-139, Portugal.,Regenerative Medicine Program, Department of Biomedical Sciences and Medicine, University of Algarve, Campus de Gambelas, Faro, 8005-139, Portugal.,Algarve Biomedical Center (ABC), University of Algarve, Campus de Gambelas, Faro, 8005-139, Portugal
| | | |
Collapse
|
70
|
Yadav H, Devalaraja S, Chung ST, Rane SG. TGF-β1/Smad3 Pathway Targets PP2A-AMPK-FoxO1 Signaling to Regulate Hepatic Gluconeogenesis. J Biol Chem 2017; 292:3420-3432. [PMID: 28069811 DOI: 10.1074/jbc.m116.764910] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 01/04/2017] [Indexed: 12/21/2022] Open
Abstract
Maintenance of glucose homeostasis is essential for normal physiology. Deviation from normal glucose levels, in either direction, increases susceptibility to serious medical complications such as hypoglycemia and diabetes. Maintenance of glucose homeostasis is achieved via functional interactions among various organs: liver, skeletal muscle, adipose tissue, brain, and the endocrine pancreas. The liver is the primary site of endogenous glucose production, especially during states of prolonged fasting. However, enhanced gluconeogenesis is also a signature feature of type 2 diabetes (T2D). Thus, elucidating the signaling pathways that regulate hepatic gluconeogenesis would allow better insight into the process of normal endogenous glucose production as well as how this process is impaired in T2D. Here we demonstrate that the TGF-β1/Smad3 signaling pathway promotes hepatic gluconeogenesis, both upon prolonged fasting and during T2D. In contrast, genetic and pharmacological inhibition of TGF-β1/Smad3 signals suppressed endogenous glucose production. TGF-β1 and Smad3 signals achieved this effect via the targeting of key regulators of hepatic gluconeogenesis, protein phosphatase 2A (PP2A), AMP-activated protein kinase (AMPK), and FoxO1 proteins. Specifically, TGF-β1 signaling suppressed the LKB1-AMPK axis, thereby facilitating the nuclear translocation of FoxO1 and activation of key gluconeogenic genes, glucose-6-phosphatase and phosphoenolpyruvate carboxykinase. These findings underscore an important role of TGF-β1/Smad3 signaling in hepatic gluconeogenesis, both in normal physiology and in the pathophysiology of metabolic diseases such as diabetes, and are thus of significant medical relevance.
Collapse
Affiliation(s)
- Hariom Yadav
- Diabetes, Endocrinology, and Obesity Branch, NIDDK, National Institutes of Health, Bethesda, Maryland 20854
| | - Samir Devalaraja
- Diabetes, Endocrinology, and Obesity Branch, NIDDK, National Institutes of Health, Bethesda, Maryland 20854
| | - Stephanie T Chung
- Diabetes, Endocrinology, and Obesity Branch, NIDDK, National Institutes of Health, Bethesda, Maryland 20854
| | - Sushil G Rane
- Diabetes, Endocrinology, and Obesity Branch, NIDDK, National Institutes of Health, Bethesda, Maryland 20854.
| |
Collapse
|
71
|
Shavva VS, Bogomolova AM, Nikitin AA, Dizhe EB, Oleinikova GN, Lapikov IA, Tanyanskiy DA, Perevozchikov AP, Orlov SV. FOXO1 and LXRα downregulate the apolipoprotein A-I gene expression during hydrogen peroxide-induced oxidative stress in HepG2 cells. Cell Stress Chaperones 2017; 22:123-134. [PMID: 27896567 PMCID: PMC5225066 DOI: 10.1007/s12192-016-0749-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Revised: 11/14/2016] [Accepted: 11/15/2016] [Indexed: 12/17/2022] Open
Abstract
Reactive oxygen species damage various cell components including DNA, proteins, and lipids, and these impairments could be a reason for severe human diseases including atherosclerosis. Forkhead box O1 (FOXO1), an important metabolic transcription factor, upregulates antioxidant and proapoptotic genes during oxidative stress. Apolipoprotein A-I (ApoA-I) forms high density lipoprotein (HDL) particles that are responsible for cholesterol transfer from peripheral tissues to liver for removal in bile in vertebrates. The main sources for plasma ApoA-I in mammals are liver and jejunum. Hepatic apoA-I transcription depends on a multitude of metabolic transcription factors. We demonstrate that ApoA-I synthesis and secretion are decreased during H2O2-induced oxidative stress in human hepatoma cell line HepG2. Here, we first show that FOXO1 binds to site B of apoA-I hepatic enhancer and downregulates apoA-I gene activity in HepG2 cells. Moreover, FOXO1 and LXRα transcription factors participate in H2O2-triggered downregulation of apoA-I gene together with Src, JNK, p38, and AMPK kinase cascades. Mutations of sites B or C as well as the administration of siRNAs against FOXO1 or LXRα to HepG2 cells abolished the hydrogen peroxide-mediated suppression of apoA-I gene.
Collapse
Affiliation(s)
- Vladimir S Shavva
- Department of Biochemistry, Institute of Experimental Medicine, Russian Academy of Medical Sciences, Acad. Pavlov St., 12, St. Petersburg, 197376, Russia.
- Department of Embryology, St. Petersburg State University, St. Petersburg, Russia.
| | | | - Artemy A Nikitin
- Department of Biochemistry, Institute of Experimental Medicine, Russian Academy of Medical Sciences, Acad. Pavlov St., 12, St. Petersburg, 197376, Russia
- Department of Biochemistry, St. Petersburg State University, St. Petersburg, Russia
| | - Ella B Dizhe
- Department of Biochemistry, Institute of Experimental Medicine, Russian Academy of Medical Sciences, Acad. Pavlov St., 12, St. Petersburg, 197376, Russia
| | - Galina N Oleinikova
- Department of Biochemistry, Institute of Experimental Medicine, Russian Academy of Medical Sciences, Acad. Pavlov St., 12, St. Petersburg, 197376, Russia
| | - Ivan A Lapikov
- Department of Embryology, St. Petersburg State University, St. Petersburg, Russia
| | - Dmitry A Tanyanskiy
- Department of Biochemistry, Institute of Experimental Medicine, Russian Academy of Medical Sciences, Acad. Pavlov St., 12, St. Petersburg, 197376, Russia
- Department of Fundamental Medicine and Medical Technologies, St. Petersburg State University, St. Petersburg, Russia
| | - Andrej P Perevozchikov
- Department of Biochemistry, Institute of Experimental Medicine, Russian Academy of Medical Sciences, Acad. Pavlov St., 12, St. Petersburg, 197376, Russia
- Department of Embryology, St. Petersburg State University, St. Petersburg, Russia
| | - Sergey V Orlov
- Department of Biochemistry, Institute of Experimental Medicine, Russian Academy of Medical Sciences, Acad. Pavlov St., 12, St. Petersburg, 197376, Russia.
- Department of Embryology, St. Petersburg State University, St. Petersburg, Russia.
| |
Collapse
|
72
|
Valenti L, Bugianesi E, Pajvani U, Targher G. Nonalcoholic fatty liver disease: cause or consequence of type 2 diabetes? Liver Int 2016; 36:1563-1579. [PMID: 27276701 DOI: 10.1111/liv.13185] [Citation(s) in RCA: 111] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2016] [Accepted: 06/06/2016] [Indexed: 02/13/2023]
Abstract
Growing epidemiological evidence suggests that nonalcoholic fatty liver disease (NAFLD) is an early predictor of and determinant for the development of type 2 diabetes and other features of the metabolic syndrome. This finding may have important clinical implications for the diagnosis, prevention and treatment of type 2 diabetes and its chronic complications. However, given the complex and bi-directional relationships between NAFLD, insulin resistance and chronic hyperglycaemia, it is extremely difficult to distinguish whether NAFLD is a cause or a consequence of insulin resistance and type 2 diabetes. Indeed, at the molecular level, hepatic lipogenesis and hepatic glucose production depend on differentially regulated branches of the insulin signalling pathway. Furthermore, genetic studies suggest that excess hepatic fat is associated with progressive liver disease, but does not always increase the risk of incident type 2 diabetes. Here, we will briefly review the epidemiological, pathophysiological and molecular evidence linking NAFLD to the development of type 2 diabetes. We will also discuss some recent genetic and therapeutic advances that seem to challenge a causal role of NAFLD in the pathogenesis type 2 diabetes, and propose a working hypothesis to explain this apparent conundrum. In conclusion, progressive liver disease and type 2 diabetes are divergent though inter-related consequences of insulin resistance and the metabolic syndrome.
Collapse
Affiliation(s)
- Luca Valenti
- Internal Medicine and Metabolic Diseases, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milano, Italy. .,Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Milano, Italy.
| | - Elisabetta Bugianesi
- Division of Gastroenterology, Department of Medical Sciences, A.O.U. Città della Salute e della Scienza, Università di Torino, Torino, Italy
| | - Utpal Pajvani
- Division of Endocrinology, Columbia University, New York, NY, USA
| | - Giovanni Targher
- Section of Endocrinology, Diabetes and Metabolism, Department of Medicine, University and Azienda Ospedaliera Universitaria Integrata of Verona, Verona, Italy
| |
Collapse
|
73
|
Lee JY, Aravinthan A, Park YS, Hwang KY, Seong SI, Hwang K. Supplementation of a Fermented Soybean Extract Reduces Body Mass and Prevents Obesity in High Fat Diet-Induced C57BL/6J Obese Mice. Prev Nutr Food Sci 2016; 21:187-196. [PMID: 27752494 PMCID: PMC5063203 DOI: 10.3746/pnf.2016.21.3.187] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 08/12/2016] [Indexed: 01/22/2023] Open
Abstract
Obesity is a growing health problem that many countries face, mostly due to the consumption of a Westernized diet. In this present study we observed the effects of a soybean extract fermented by Bacillus subtilis MORI (BTD-1) containing 1-deoxynojirimycin against high fat diet-induced obesity. The results obtained from this study indicated that BTD-1 reduced body weight, regulated hepatic lipid content and adipose tissue, and also affected liver antioxidant enzymes and glucose metabolism. These results suggest that administration of BTD-1 affects obesity by inhibiting hyperglycemia and free radical-mediated stress; it also reduces lipid accumulation. Therefore, BTD-1 may be potentially useful for the prevention of obesity and its related secondary complications.
Collapse
Affiliation(s)
- Jae Yeon Lee
- R&D Center for Life Science, Biotopia Co., Ltd., Gangwon 24398, Korea
| | - Adithan Aravinthan
- Department of Physiology, College of Veterinary Medicine, Chonbuk National University, Jeonbuk 54596, Korea
| | - Young Shik Park
- R&D Center for Life Science, Biotopia Co., Ltd., Gangwon 24398, Korea
| | - Kyo Yeol Hwang
- R&D Center for Life Science, Biotopia Co., Ltd., Gangwon 24398, Korea
| | - Su-Il Seong
- R&D Center for Life Science, Biotopia Co., Ltd., Gangwon 24398, Korea
| | - Kwontack Hwang
- Department of Food and Nutrition, Nambu University, Gwangju 62271, Korea
| |
Collapse
|
74
|
Shavva VS, Bogomolova AM, Nikitin AA, Dizhe EB, Tanyanskiy DA, Efremov AM, Oleinikova GN, Perevozchikov AP, Orlov SV. Insulin-Mediated Downregulation of Apolipoprotein A-I Gene in Human Hepatoma Cell Line HepG2: The Role of Interaction Between FOXO1 and LXRβ Transcription Factors. J Cell Biochem 2016; 118:382-396. [PMID: 27404023 DOI: 10.1002/jcb.25651] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2016] [Accepted: 07/11/2016] [Indexed: 12/22/2022]
Abstract
Apolipoprotein A-I (ApoA-I) is a key component of high density lipoproteins which possess anti-atherosclerotic and anti-inflammatory properties. Insulin is a crucial mediator of the glucose and lipid metabolism that has been implicated in atherosclerotic and inflammatory processes. Important mediators of insulin signaling such as Liver X Receptors (LXRs) and Forkhead Box A2 (FOXA2) are known to regulate apoA-I expression in liver. Forkhead Box O1 (FOXO1) is a well-known target of insulin signaling and a key mediator of oxidative stress response. Low doses of insulin were shown to activate apoA-I expression in human hepatoma HepG2 cells. However, the detailed mechanisms for these processes are still unknown. We studied the possible involvement of FOXO1, FOXA2, LXRα, and LXRβ transcription factors in the insulin-mediated regulation of apoA-I expression. Treatment of HepG2 cells with high doses of insulin (48 h, 100 nM) suppresses apoA-I gene expression. siRNAs against FOXO1, FOXA2, LXRβ, or LXRα abrogated this effect. FOXO1 forms a complex with LXRβ and insulin treatment impairs FOXO1/LXRβ complex binding to hepatic enhancer and triggers its nuclear export. Insulin as well as LXR ligand TO901317 enhance the interaction between FOXA2, LXRα, and hepatic enhancer. These data suggest that high doses of insulin downregulate apoA-I gene expression in HepG2 cells through redistribution of FOXO1/LXRβ complex, FOXA2, and LXRα on hepatic enhancer of apoA-I gene. J. Cell. Biochem. 118: 382-396, 2017. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Vladimir S Shavva
- Department of Biochemistry, Institute of Experimental Medicine, Russian Academy of Medical Sciences, St. Petersburg, Russia.,Department of Embryology, St. Petersburg State University, St. Petersburg, Russia
| | | | - Artemy A Nikitin
- Department of Biochemistry, Institute of Experimental Medicine, Russian Academy of Medical Sciences, St. Petersburg, Russia.,Department of Biochemistry, St. Petersburg State University, St. Petersburg, Russia
| | - Ella B Dizhe
- Department of Biochemistry, Institute of Experimental Medicine, Russian Academy of Medical Sciences, St. Petersburg, Russia
| | - Dmitry A Tanyanskiy
- Department of Biochemistry, Institute of Experimental Medicine, Russian Academy of Medical Sciences, St. Petersburg, Russia.,Department of Fundamental Medicine and Medical Technologies, St. Petersburg State University, St. Petersburg, Russia
| | - Alexander M Efremov
- Department of Biochemistry, Institute of Experimental Medicine, Russian Academy of Medical Sciences, St. Petersburg, Russia.,Department of Embryology, St. Petersburg State University, St. Petersburg, Russia
| | - Galina N Oleinikova
- Department of Biochemistry, Institute of Experimental Medicine, Russian Academy of Medical Sciences, St. Petersburg, Russia
| | - Andrej P Perevozchikov
- Department of Biochemistry, Institute of Experimental Medicine, Russian Academy of Medical Sciences, St. Petersburg, Russia.,Department of Embryology, St. Petersburg State University, St. Petersburg, Russia
| | - Sergey V Orlov
- Department of Biochemistry, Institute of Experimental Medicine, Russian Academy of Medical Sciences, St. Petersburg, Russia.,Department of Embryology, St. Petersburg State University, St. Petersburg, Russia
| |
Collapse
|
75
|
Selenoproteins: Antioxidant selenoenzymes and beyond. Arch Biochem Biophys 2016; 595:113-9. [PMID: 27095226 DOI: 10.1016/j.abb.2015.06.024] [Citation(s) in RCA: 192] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 06/08/2015] [Indexed: 11/21/2022]
Abstract
Adequate intake of the essential trace element and micronutrient selenium is thought to be beneficial for maintaining human health. Selenium may modulate a broad spectrum of key biological processes, including the cellular response to oxidative stress, redox signalling, cellular differentiation, the immune response, and protein folding. Biochemical and cellular effects of selenium are achieved through activities of selenocysteine-containing selenoproteins. This small yet essential group comprises proteins encoded by 25 genes in humans, e.g. oxidoreductases such as glutathione peroxidases (GPx) and thioredoxin reductases (TrxR), as well as the iodothyronine deiodinases (DIO) and the plasma selenium transport protein, selenoprotein P (SePP1). Synthetic selenoorganic compounds, including the GPx mimetic ebselen, have also been applied in biological systems in vitro and in vivo; antioxidant and anti-inflammatory actions of ebselen and its history as a drug candidate are summarised here. Furthermore, we discuss several aspects of selenoprotein biochemistry, ranging from their well-known importance for cellular protection against oxidative damage to more recent data that link selenoprotein expression/activity to enterocyte and adipocyte differentiation and function and to (dys)regulation of insulin action and secretion.
Collapse
|
76
|
Röder PV, Wu B, Liu Y, Han W. Pancreatic regulation of glucose homeostasis. Exp Mol Med 2016; 48:e219. [PMID: 26964835 PMCID: PMC4892884 DOI: 10.1038/emm.2016.6] [Citation(s) in RCA: 454] [Impact Index Per Article: 56.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Revised: 12/03/2015] [Accepted: 12/06/2015] [Indexed: 12/11/2022] Open
Abstract
In order to ensure normal body function, the human body is dependent on a tight control of its blood glucose levels. This is accomplished by a highly sophisticated network of various hormones and neuropeptides released mainly from the brain, pancreas, liver, intestine as well as adipose and muscle tissue. Within this network, the pancreas represents a key player by secreting the blood sugar-lowering hormone insulin and its opponent glucagon. However, disturbances in the interplay of the hormones and peptides involved may lead to metabolic disorders such as type 2 diabetes mellitus (T2DM) whose prevalence, comorbidities and medical costs take on a dramatic scale. Therefore, it is of utmost importance to uncover and understand the mechanisms underlying the various interactions to improve existing anti-diabetic therapies and drugs on the one hand and to develop new therapeutic approaches on the other. This review summarizes the interplay of the pancreas with various other organs and tissues that maintain glucose homeostasis. Furthermore, anti-diabetic drugs and their impact on signaling pathways underlying the network will be discussed.
Collapse
Affiliation(s)
- Pia V Röder
- Metabolism in Human Diseases Unit, Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
- Metabolism in Human Diseases Unit, Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore 138673, Singapore. E-mail: or
| | - Bingbing Wu
- Laboratory of Metabolic Medicine, Singapore Bioimaging Consortium, A*STAR, Singapore, Singapore
| | - Yixian Liu
- Laboratory of Metabolic Medicine, Singapore Bioimaging Consortium, A*STAR, Singapore, Singapore
| | - Weiping Han
- Metabolism in Human Diseases Unit, Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
- Laboratory of Metabolic Medicine, Singapore Bioimaging Consortium, A*STAR, Singapore, Singapore
- Metabolism in Human Diseases Unit, Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore 138673, Singapore. E-mail: or
| |
Collapse
|
77
|
Forkhead box transcription factor 1: role in the pathogenesis of diabetic cardiomyopathy. Cardiovasc Diabetol 2016; 15:44. [PMID: 26956801 PMCID: PMC4784400 DOI: 10.1186/s12933-016-0361-1] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 03/02/2016] [Indexed: 12/17/2022] Open
Abstract
Diabetic cardiomyopathy (DCM) is a disorder of the heart muscle in people with diabetes that can occur independent of hypertension or vascular disease. The underlying mechanism of DCM is incompletely understood. Some transcription factors have been suggested to regulate the gene program intricate in the pathogenesis of diabetes prompted cardiac injury. Forkhead box transcription factor 1 is a pleiotropic transcription factor that plays a pivotal role in a variety of physiological processes. Altered FOXO1 expression and function have been associated with cardiovascular diseases, and the important role of FOXO1 in DCM has begun to attract attention. In this review, we focus on the FOXO1 pathway and its role in various processes that have been related to DCM, such as metabolism, oxidative stress, endothelial dysfunction, inflammation and apoptosis.
Collapse
|
78
|
Chen Q, Lu M, Monks BR, Birnbaum MJ. Insulin Is Required to Maintain Albumin Expression by Inhibiting Forkhead Box O1 Protein. J Biol Chem 2015; 291:2371-8. [PMID: 26668316 DOI: 10.1074/jbc.m115.677351] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Indexed: 01/07/2023] Open
Abstract
Diabetes is accompanied by dysregulation of glucose, lipid, and protein metabolism. In recent years, much effort has been spent on understanding how insulin regulates glucose and lipid metabolism, whereas the effect of insulin on protein metabolism has received less attention. In diabetes, hepatic production of serum albumin decreases, and it has been long established that insulin positively controls albumin gene expression. In this study, we used a genetic approach in mice to identify the mechanism by which insulin regulates albumin gene transcription. Albumin expression was decreased significantly in livers with insulin signaling disrupted by ablation of the insulin receptor or Akt. Concomitant deletion of Forkhead Box O1 (Foxo1) in these livers rescued the decreased albumin secretion. Furthermore, activation of Foxo1 in the liver is sufficient to suppress albumin expression. These results suggest that Foxo1 acts as a repressor of albumin expression.
Collapse
Affiliation(s)
- Qing Chen
- From the Institute for Diabetes, Obesity, and Metabolism, Department of Biochemistry and Biophysics, and Graduate Group of Biochemistry and Molecular Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104 and
| | - Mingjian Lu
- From the Institute for Diabetes, Obesity, and Metabolism
| | - Bobby R Monks
- From the Institute for Diabetes, Obesity, and Metabolism
| | - Morris J Birnbaum
- From the Institute for Diabetes, Obesity, and Metabolism, Department of Biochemistry and Biophysics, and Graduate Group of Biochemistry and Molecular Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104 and the Cardiovascular and Metabolic Disease Research Unit, Pfizer Inc., Cambridge, Massachusetts 02140
| |
Collapse
|
79
|
Zou Y, Gong N, Cui Y, Wang X, Cui A, Chen Q, Jiao T, Dong X, Yang H, Zhang S, Fang F, Chang Y. Forkhead Box P1 (FOXP1) Transcription Factor Regulates Hepatic Glucose Homeostasis. J Biol Chem 2015; 290:30607-15. [PMID: 26504089 DOI: 10.1074/jbc.m115.681627] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Indexed: 11/06/2022] Open
Abstract
Dysregulation of hepatic gluconeogenesis contributes to the pathogenesis of diabetes, yet the detailed molecular mechanisms remain to be fully elucidated. Here we show that FOXP1, a transcriptional repressor, plays a key role in the regulation of systemic glucose homeostasis. Hepatic expression levels of FOXP1 are decreased in diabetic mice. Modest hepatic overexpression of FOXP1 in mice inhibited the expression of gluconeogenic genes, such as peroxisome proliferators-activated receptor γ coactivator-1α (PGC-1α), phosphoenolpyruvate carboxykinase (PEPCK), and glucose-6-phosphatase (G6PC), leading to a decrease in hepatic glucose production and fasting blood glucose levels in normal mice and different mouse models of diabetes, including db/db diabetic and high-fat diet-induced obese mice. FOXP1 physically interacted with FOXO1 in vivo and competed with FOXO1 for binding to the insulin response element in the promoter region of gluconeogenic genes, thereby interfering expression of these genes. These results identify a previously unrecognized role for FOXP1 in the transcriptional control of hepatic glucose homeostasis.
Collapse
Affiliation(s)
- Yongkang Zou
- From the National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China and
| | - Ning Gong
- From the National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China and
| | - Ying Cui
- From the National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China and
| | - Xiaojuan Wang
- From the National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China and
| | - Anfang Cui
- From the National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China and
| | - Qi Chen
- From the National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China and
| | - Tao Jiao
- From the National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China and
| | - Xueyu Dong
- From the National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China and
| | - Hao Yang
- From the National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China and
| | - Shutian Zhang
- the Beijing Friendship Hospital Affiliated to the Capital Medical University, Beijing Key Laboratory for Precancerous Lesion of Digestive Diseases, Beijing Digestive Disease Center, Beijing, China
| | - Fude Fang
- From the National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China and
| | - Yongsheng Chang
- From the National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China and
| |
Collapse
|
80
|
Sin TK, Yung BY, Yip SP, Chan LW, Wong CS, Tam EW, Siu PM. SIRT1-dependent myoprotective effects of resveratrol on muscle injury induced by compression. Front Physiol 2015; 6:293. [PMID: 26557094 PMCID: PMC4617057 DOI: 10.3389/fphys.2015.00293] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 10/05/2015] [Indexed: 01/01/2023] Open
Abstract
Our current understanding on the molecular mechanisms by which sustained compression induces skeletal muscle injury is very limited. This study aimed to test the hypothesis that activation of SIRT1 by the natural antioxidant resveratrol could deactivate apoptotic and catabolic signaling in skeletal muscle exposed to moderate compression. Two cycles of 6-h constant pressure at 100 mmHg was applied to the tibialis region of right, but not left hindlimbs of Sprague Dawley rats pre-treated with DMSO (vehicle control) or resveratrol with/without sirtinol. Skeletal muscle tissues lying underneath and spatially corresponding to the compressed sites were collected for analyses. Resveratrol prevented the compression-induced manifestations of pathohistological damages including elevations of the number of interstitial nuclei and area of interstitial space and ameliorated oxidative damages measured as 4-hydroxy-2-nonenal (4HNE) and nitrotyrosine in skeletal muscle. In parallel, resveratrol augmented the expression level and activity of SIRT1 and phosphorylation levels of Foxo3a and Akt while suppressed the increases in protein abundances of p53, Bax, MAFbx, and ubiquitin, enzymatic activities of caspase 3 and 20S proteasome, and apoptotic DNA fragmentation in the compressed muscle. These favorable myoprotective effects of resveratrol were diminished upon pharmacological blockade of SIRT1 by using sirtinol. These novel data support the hypothesis that the anti-apoptotic and anti-catabolic effects of resveratrol on compression injury in skeletal muscle required the action of SIRT1.
Collapse
Affiliation(s)
- Thomas K Sin
- Department of Health Technology and Informatics, Faculty of Health and Social Sciences, The Hong Kong Polytechnic University Hong Kong, Hong Kong
| | - Benjamin Y Yung
- Department of Health Technology and Informatics, Faculty of Health and Social Sciences, The Hong Kong Polytechnic University Hong Kong, Hong Kong
| | - Shea P Yip
- Department of Health Technology and Informatics, Faculty of Health and Social Sciences, The Hong Kong Polytechnic University Hong Kong, Hong Kong
| | - Lawrence W Chan
- Department of Health Technology and Informatics, Faculty of Health and Social Sciences, The Hong Kong Polytechnic University Hong Kong, Hong Kong
| | - Cesar S Wong
- Department of Health Technology and Informatics, Faculty of Health and Social Sciences, The Hong Kong Polytechnic University Hong Kong, Hong Kong
| | - Eric W Tam
- Interdisciplinary Division of Biomedical Engineering, Faculty of Engineering, The Hong Kong Polytechnic University Hong Kong, Hong Kong
| | - Parco M Siu
- Department of Health Technology and Informatics, Faculty of Health and Social Sciences, The Hong Kong Polytechnic University Hong Kong, Hong Kong
| |
Collapse
|
81
|
Sadi G, Pektaş MB, Koca HB, Tosun M, Koca T. Resveratrol improves hepatic insulin signaling and reduces the inflammatory response in streptozotocin-induced diabetes. Gene 2015; 570:213-20. [DOI: 10.1016/j.gene.2015.06.019] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 05/23/2015] [Accepted: 06/06/2015] [Indexed: 11/15/2022]
|
82
|
Camer D, Yu Y, Szabo A, Dinh CHL, Wang H, Cheng L, Huang XF. Bardoxolone methyl prevents insulin resistance and the development of hepatic steatosis in mice fed a high-fat diet. Mol Cell Endocrinol 2015; 412:36-43. [PMID: 26001833 DOI: 10.1016/j.mce.2015.05.018] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Revised: 04/27/2015] [Accepted: 05/15/2015] [Indexed: 02/07/2023]
Abstract
High-fat (HF) diet-induced obesity is a major risk factor for the development of insulin resistance and hepatic steatosis. We examined the hypothesis that bardoxolone methyl (BM) would prevent the development of insulin resistance and hepatic steatosis in mice fed a HF diet. C57BL/6J male mice were fed a lab chow (LC), HF (40% fat), or HF diet supplemented with 10 mg/kg/day BM orally for 21 weeks. Glucose metabolism was assessed using a glucose tolerance test (GTT) and insulin sensitivity test (IST). Signalling molecules involved in insulin resistance, inflammation, and lipid metabolism were examined in liver tissue via western blotting and RT-PCR. BM prevented HF diet-induced insulin resistance and alterations in the protein levels of protein tyrosine phosphatase 1B (PTP1B), forkhead box protein O1 (FOXO1) and BDNF, and expression of the insulin receptor (IR), IRS-1 and glucose-6-phosphatase (G6Pase) genes. Furthermore, BM prevented fat accumulation in the liver and decreases in the β-oxidation gene, peroxisomal acyl-coenzyme A oxidase 1 (ACOX) in mice fed a HF diet. In the livers of HF fed mice, BM administration prevented HF diet-induced macrophage infiltration, inflammation as indicated by reduced IL-6 and signal transducer and activator of transcription 3 (STAT3) protein levels and TNFα mRNA expression, and increased nuclear factor-like 2 (Nrf2) mRNA expression and nuclear protein levels. These findings suggest that BM prevents HF diet induced insulin resistance and the development of hepatic steatosis in mice fed a chronic HF diet through modulation of molecules involved in insulin signalling, lipid metabolism and inflammation in the liver.
Collapse
Affiliation(s)
- Danielle Camer
- Centre for Translational Neuroscience, Faculty of Science, Medicine and Health and Illawarra Health and Medical Research Institute, University of Wollongong, NSW 2522, Australia
| | - Yinghua Yu
- Centre for Translational Neuroscience, Faculty of Science, Medicine and Health and Illawarra Health and Medical Research Institute, University of Wollongong, NSW 2522, Australia
| | - Alexander Szabo
- Centre for Translational Neuroscience, Faculty of Science, Medicine and Health and Illawarra Health and Medical Research Institute, University of Wollongong, NSW 2522, Australia; ANSTO LifeSciences, Australian Nuclear Science and Technology Organisation, NSW 2234, Australia
| | - Chi H L Dinh
- Centre for Translational Neuroscience, Faculty of Science, Medicine and Health and Illawarra Health and Medical Research Institute, University of Wollongong, NSW 2522, Australia
| | - Hongqin Wang
- Centre for Translational Neuroscience, Faculty of Science, Medicine and Health and Illawarra Health and Medical Research Institute, University of Wollongong, NSW 2522, Australia
| | - Licai Cheng
- Centre for Translational Neuroscience, Faculty of Science, Medicine and Health and Illawarra Health and Medical Research Institute, University of Wollongong, NSW 2522, Australia
| | - Xu-Feng Huang
- Centre for Translational Neuroscience, Faculty of Science, Medicine and Health and Illawarra Health and Medical Research Institute, University of Wollongong, NSW 2522, Australia.
| |
Collapse
|
83
|
Nachar A, Saleem A, Arnason JT, Haddad PS. Regulation of liver cell glucose homeostasis by dehydroabietic acid, abietic acid and squalene isolated from balsam fir (Abies balsamea (L.) Mill.) a plant of the Eastern James Bay Cree traditional pharmacopeia. PHYTOCHEMISTRY 2015; 117:373-379. [PMID: 26164238 DOI: 10.1016/j.phytochem.2015.07.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 06/29/2015] [Accepted: 07/01/2015] [Indexed: 06/04/2023]
Abstract
In our previous study, Abies balsamea (L.) Mill., a plant used in Cree traditional medicine, had a strong effect on the regulation of glucose homeostasis in liver cells. This study aimed to isolate and identify its active constituents using a bioassay-guided fractionation approach as well as to elucidate their mechanism(s) of action. The effect of the crude extract and its constituents was evaluated on the activity of Glucose-6-Phosphatase (G6Pase) and Glycogen Synthase (GS) and phosphorylation of three kinases, AMP-activated protein kinase (AMPK), Akt and Glycogen Synthase Kinase-3 (GSK-3). Three compounds, abietic acid, dehydroabietic acid and squalene, were isolated from the most active fraction in the bioassays (hexane). The compounds were able to decrease the activity of G6Pase and to stimulate GS. Their effect on G6Pase activity involved both Akt and AMPK phosphorylation with significant correlations between insulin-dependent and -independent pathways and the bioassay. In addition, the compounds were able to stimulate GS through GSK-3 phosphorylation with a significant correlation between the signaling pathway and the bioassay. Dehydroabietic acid stood out for its strongest effect in all the experiments close to that of the crude extract. These compounds may have potential applications in the treatment of type 2 diabetes and insulin resistance.
Collapse
Affiliation(s)
- Abir Nachar
- Natural Health Products and Metabolic Diseases Laboratory, Dept. of Pharmacology, Université de Montréal, Montreal, QC, Canada; Canadian Institutes of Health Research Team in Aboriginal Antidiabetic Medicines and Montreal Diabetes Research Center, Canada
| | - Ammar Saleem
- Canadian Institutes of Health Research Team in Aboriginal Antidiabetic Medicines and Montreal Diabetes Research Center, Canada; Laboratory for the Analysis of Natural and Synthetic Environmental Toxins, University of Ottawa, Ottawa, ON, Canada
| | - John T Arnason
- Canadian Institutes of Health Research Team in Aboriginal Antidiabetic Medicines and Montreal Diabetes Research Center, Canada; Laboratory for the Analysis of Natural and Synthetic Environmental Toxins, University of Ottawa, Ottawa, ON, Canada
| | - Pierre S Haddad
- Natural Health Products and Metabolic Diseases Laboratory, Dept. of Pharmacology, Université de Montréal, Montreal, QC, Canada; Canadian Institutes of Health Research Team in Aboriginal Antidiabetic Medicines and Montreal Diabetes Research Center, Canada.
| |
Collapse
|
84
|
Klotz LO, Sánchez-Ramos C, Prieto-Arroyo I, Urbánek P, Steinbrenner H, Monsalve M. Redox regulation of FoxO transcription factors. Redox Biol 2015; 6:51-72. [PMID: 26184557 PMCID: PMC4511623 DOI: 10.1016/j.redox.2015.06.019] [Citation(s) in RCA: 515] [Impact Index Per Article: 57.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Revised: 06/25/2015] [Accepted: 06/30/2015] [Indexed: 12/19/2022] Open
Abstract
Transcription factors of the forkhead box, class O (FoxO) family are important regulators of the cellular stress response and promote the cellular antioxidant defense. On one hand, FoxOs stimulate the transcription of genes coding for antioxidant proteins located in different subcellular compartments, such as in mitochondria (i.e. superoxide dismutase-2, peroxiredoxins 3 and 5) and peroxisomes (catalase), as well as for antioxidant proteins found extracellularly in plasma (e.g., selenoprotein P and ceruloplasmin). On the other hand, reactive oxygen species (ROS) as well as other stressful stimuli that elicit the formation of ROS, may modulate FoxO activity at multiple levels, including posttranslational modifications of FoxOs (such as phosphorylation and acetylation), interaction with coregulators, alterations in FoxO subcellular localization, protein synthesis and stability. Moreover, transcriptional and posttranscriptional control of the expression of genes coding for FoxOs is sensitive to ROS. Here, we review these aspects of FoxO biology focusing on redox regulation of FoxO signaling, and with emphasis on the interplay between ROS and FoxOs under various physiological and pathophysiological conditions. Of particular interest are the dual role played by FoxOs in cancer development and their key role in whole body nutrient homeostasis, modulating metabolic adaptations and/or disturbances in response to low vs. high nutrient intake. Examples discussed here include calorie restriction and starvation as well as adipogenesis, obesity and type 2 diabetes.
Collapse
Affiliation(s)
- Lars-Oliver Klotz
- Institute of Nutrition, Department of Nutrigenomics, Friedrich-Schiller-Universität Jena, Dornburger Straße 29, 07743 Jena, Germany.
| | - Cristina Sánchez-Ramos
- Instituto de Investigaciones Biomédicas "Alberto Sols" (CSIC-UAM), Arturo Duperier, 4, 28029 Madrid, Spain
| | - Ignacio Prieto-Arroyo
- Instituto de Investigaciones Biomédicas "Alberto Sols" (CSIC-UAM), Arturo Duperier, 4, 28029 Madrid, Spain
| | - Pavel Urbánek
- Institute of Nutrition, Department of Nutrigenomics, Friedrich-Schiller-Universität Jena, Dornburger Straße 29, 07743 Jena, Germany
| | - Holger Steinbrenner
- Institute of Nutrition, Department of Nutrigenomics, Friedrich-Schiller-Universität Jena, Dornburger Straße 29, 07743 Jena, Germany
| | - Maria Monsalve
- Instituto de Investigaciones Biomédicas "Alberto Sols" (CSIC-UAM), Arturo Duperier, 4, 28029 Madrid, Spain.
| |
Collapse
|
85
|
O-Sullivan I, Zhang W, Wasserman DH, Liew CW, Liu J, Paik J, DePinho RA, Stolz DB, Kahn CR, Schwartz MW, Unterman TG. FoxO1 integrates direct and indirect effects of insulin on hepatic glucose production and glucose utilization. Nat Commun 2015; 6:7079. [PMID: 25963540 PMCID: PMC4755301 DOI: 10.1038/ncomms8079] [Citation(s) in RCA: 149] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 04/01/2015] [Indexed: 12/18/2022] Open
Abstract
FoxO proteins are major targets of insulin action. To better define the role of FoxO1 in mediating insulin effects in the liver, we generated liver-specific insulin receptor knockout (LIRKO) and IR/FoxO1 double knockout (LIRFKO) mice. Here we show that LIRKO mice are severely insulin resistant based on glucose, insulin and C-peptide levels, and glucose and insulin tolerance tests, and genetic deletion of hepatic FoxO1 reverses these effects. (13)C-glucose and insulin clamp studies indicate that regulation of both hepatic glucose production (HGP) and glucose utilization is impaired in LIRKO mice, and these defects are also restored in LIRFKO mice corresponding to changes in gene expression. We conclude that (1) inhibition of FoxO1 is critical for both direct (hepatic) and indirect effects of insulin on HGP and utilization, and (2) extrahepatic effects of insulin are sufficient to maintain normal whole-body and hepatic glucose metabolism when liver FoxO1 activity is disrupted.
Collapse
Affiliation(s)
- InSug O-Sullivan
- Section of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Illinois at Chicago College of Medicine, Chicago, Illinois 60612, USA
| | - Wenwei Zhang
- Section of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Illinois at Chicago College of Medicine, Chicago, Illinois 60612, USA
| | - David H Wasserman
- Department of Molecular Physiology and Biophysics, Vanderbilt Medical School, Nashville, Tennesse 37232, USA
| | - Chong Wee Liew
- Department of Physiology and Biophysics, University of Illinois at Chicago College of Medicine, Chicago, Illinois 60612, USA
| | - Jonathan Liu
- Section of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Illinois at Chicago College of Medicine, Chicago, Illinois 60612, USA
| | - Jihye Paik
- Dana Farber Cancer Institute, Boston, Massachusetts 02215, USA
| | | | - Donna Beer Stolz
- Department of Cell Biology, Center for Biologic Imaging, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA
| | - C Ronald Kahn
- Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts 02215, USA
| | - Michael W Schwartz
- Diabetes and Obesity Center of Excellence, University of Washington, Seattle, Washington 98104, USA
| | - Terry G Unterman
- 1] Section of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Illinois at Chicago College of Medicine, Chicago, Illinois 60612, USA [2] Medical Service, Jesse Brown VA Medical Center, 820 South Damen Avenue, Chicago, Illinois 60612, USA, USA
| |
Collapse
|
86
|
Calabuig-Navarro V, Yamauchi J, Lee S, Zhang T, Liu YZ, Sadlek K, Coudriet GM, Piganelli JD, Jiang CL, Miller R, Lowe M, Harashima H, Dong HH. Forkhead Box O6 (FoxO6) Depletion Attenuates Hepatic Gluconeogenesis and Protects against Fat-induced Glucose Disorder in Mice. J Biol Chem 2015; 290:15581-15594. [PMID: 25944898 DOI: 10.1074/jbc.m115.650994] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Indexed: 12/22/2022] Open
Abstract
Excessive endogenous glucose production contributes to fasting hyperglycemia in diabetes. FoxO6 is a distinct member of the FoxO subfamily. To elucidate the role of FoxO6 in hepatic gluconeogenesis and assess its contribution to the pathogenesis of fasting hyperglycemia in diabetes, we generated FoxO6 knock-out (FoxO6-KO) mice followed by determining the effect of FoxO6 loss-of-function on hepatic gluconeogenesis under physiological and pathological conditions. FoxO6 depletion attenuated hepatic gluconeogenesis and lowered fasting glycemia in FoxO6-KO mice. FoxO6-deficient primary hepatocytes were associated with reduced capacities to produce glucose in response to glucagon. When fed a high fat diet, FoxO6-KO mice exhibited significantly enhanced glucose tolerance and reduced blood glucose levels accompanied by improved insulin sensitivity. These effects correlated with attenuated hepatic gluconeogenesis in FoxO6-KO mice. In contrast, wild-type littermates developed fat-induced glucose intolerance with a concomitant induction of fasting hyperinsulinemia and hyperglycemia. Furthermore, FoxO6-KO mice displayed significantly diminished macrophage infiltration into liver and adipose tissues, correlating with the reduction of macrophage expression of C-C chemokine receptor 2 (CCR2), a factor that is critical for regulating macrophage recruitment in peripheral tissues. Our data indicate that FoxO6 depletion protected against diet-induced glucose intolerance and insulin resistance by attenuating hepatic gluconeogenesis and curbing macrophage infiltration in liver and adipose tissues in mice.
Collapse
Affiliation(s)
- Virtu Calabuig-Navarro
- Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224
| | - Jun Yamauchi
- Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224; Laboratory for Molecular Design of Pharmaceutics, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Hokkaido 060-0812, Japan
| | - Sojin Lee
- Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224
| | - Ting Zhang
- Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224
| | - Yun-Zi Liu
- Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224; Laboratory of Stress Medicine, Faculty of Psychology and Mental Health, Second Military Medical University, 200433 Shanghai, China
| | - Kelsey Sadlek
- Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224
| | - Gina M Coudriet
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224
| | - Jon D Piganelli
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224
| | - Chun-Lei Jiang
- Laboratory of Stress Medicine, Faculty of Psychology and Mental Health, Second Military Medical University, 200433 Shanghai, China
| | - Rita Miller
- Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224
| | - Mark Lowe
- Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224
| | - Hideyoshi Harashima
- Laboratory for Molecular Design of Pharmaceutics, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Hokkaido 060-0812, Japan
| | - H Henry Dong
- Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224.
| |
Collapse
|
87
|
Mendler M, Schlotterer A, Ibrahim Y, Kukudov G, Fleming T, Bierhaus A, Riedinger C, Schwenger V, Herzig S, Hecker M, Tyedmers J, Nawroth PP, Morcos M. daf-16/FOXO and glod-4/glyoxalase-1 are required for the life-prolonging effect of human insulin under high glucose conditions in Caenorhabditis elegans. Diabetologia 2015; 58:393-401. [PMID: 25322843 DOI: 10.1007/s00125-014-3415-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Accepted: 09/19/2014] [Indexed: 10/24/2022]
Abstract
AIMS/HYPOTHESIS The aim of this study was to determine the protective effects of human insulin and its analogues, B28Asp human insulin (insulin aspart) and B29Lys(ε-tetradecanoyl),desB30 human insulin (insulin detemir), against glucose-induced lifespan reduction and neuronal damage in the model organism Caenorhabditis elegans and to elucidate the underlying mechanisms. METHODS Nematodes were cultivated under high glucose (HG) conditions comparable with the situation in diabetic patients and treated with human insulin and its analogues. Lifespan was assessed and neuronal damage was evaluated with regard to structural and functional impairment. Additionally, the activity of glyoxalase-1 and superoxide dismutase (SOD) and the formation of reactive oxygen species (ROS) and AGEs were determined. RESULTS Insulin and its analogues reversed the life-shortening effect of HG conditions and prevented the glucose-induced neuronal impairment. Insulin treatment under HG conditions was associated with reduced concentration of glucose, as well as a reduced formation of ROS and AGEs, and increased SOD activity. These effects were dependent on the Forkhead box O (FOXO) homologue abnormal dauer formation (DAF)-16. Furthermore, glyoxalase-1 activity, which was impaired under HG conditions, was restored by human insulin. This was essential for the insulin-induced lifespan extension under HG conditions, as no change in lifespan was observed following either suppression or overexpression of glyoxalase-1. CONCLUSIONS/INTERPRETATION Human insulin and its analogues prevent the reduction in lifespan and neuronal damage caused by HG conditions. The effect of human insulin is mediated by a daf-2/insulin receptor and daf-16/FOXO-dependent pathway and is mediated by upregulation of detoxifying mechanisms.
Collapse
Affiliation(s)
- Michael Mendler
- Department of Medicine 1 and Clinical Chemistry, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany,
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
88
|
Transcription factor TIP27 regulates glucose homeostasis and insulin sensitivity in a PI3-kinase/Akt-dependent manner in mice. Int J Obes (Lond) 2015; 39:949-58. [PMID: 25614086 DOI: 10.1038/ijo.2015.5] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Revised: 11/26/2014] [Accepted: 11/30/2014] [Indexed: 01/09/2023]
Abstract
BACKGROUND/OBJECTIVES Juxtaposed with another zinc-finger gene 1 (TIP27 or JAZF1) is a 27-kDa transcription factor, and genome-wide association studies have recently revealed TIP27 to be associated with type 2 diabetes. However, little is known about its role in the regulation of metabolism. In this study, we investigated the effects of TIP27 overexpression on glucose homeostasis and insulin signaling in high-fat diet (HFD)-fed TIP27 transgenic (TIP27-Tg) mice and db/db mice. METHODS We assessed the effects of TIP27 overexpression in both TIP27-Tg mice and db/db mice on glucose metabolism and changes in insulin sensitivity during glucose (GTT) and insulin (ITT) tolerance tests. A hyperinsulinemic-euglycemic clamp was performed on TIP27-Tg mice. Real-time quantitative PCR and western blotting were used to assess mRNA and protein expressions. RESULTS TIP27 overexpression in TIP27-Tg mice and in db/db mice led to reduced total cholesterol and fasting plasma insulin levels, and enhanced glucose tolerance and insulin sensitivity during GTT and ITT. Hyperinsulinemic-euglycemic clamp experiments demonstrated that HFD-fed TIP27-Tg mice had lower hepatic glucose production and higher insulin sensitivity compared with nontransgenic littermates. In addition, the hepatic expressions of phosphoenolpyruate carboxykinase (PEPCK), glucose-6-phosphatase (G6Pase) mRNAs and proteins were significantly decreased, whereas the phosphorylation of insulin receptor, insulin receptor substrate-1, adenosine monophosphate-activated protein kinase and Akt kinase (Akt) in the liver was significantly increased in HFD-fed TIP27-Tg mice compared with nontransgenic littermates. Adenovirus-mediated TIP27 overexpression in db/db mice also decreased the expression of gluconeogenic genes and increased the phosphorylation of insulin signaling molecules in the liver compared with controls. Finally, LY294002, a phosphatidylinositol 3-kinase (PI3-kinase) inhibitor, abolished the suppressive effect of TIP27 overexpression on PEPCK and G6Pase expression. CONCLUSIONS TIP27 has an important role in glucose homeostasis through the regulation of hepatic glucose metabolism and insulin sensitivity. Furthermore, this regulation requires activation of PI3-kinase.
Collapse
|
89
|
Blaabjerg L, Christensen GL, Matsumoto M, van der Meulen T, Huising MO, Billestrup N, Vale WW. CRFR1 activation protects against cytokine-induced β-cell death. J Mol Endocrinol 2014; 53:417-27. [PMID: 25324488 PMCID: PMC4518718 DOI: 10.1530/jme-14-0056] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
During the development of diabetes β-cells are exposed to elevated concentrations of proinflammatory cytokines, TNFα and IL1β, which in vitro induce β-cell death. The class B G-protein-coupled receptors (GPCRs): corticotropin-releasing factor receptor 1 (CRFR1) and CRFR2 are expressed in pancreatic islets. As downstream signaling by other class B GPCRs can protect against cytokine-induced β-cell apoptosis, we evaluated the protective potential of CRFR activation in β-cells in a pro-inflammatory setting. CRFR1/CRFR2 ligands activated AKT and CRFR1 signaling and reduced apoptosis in human islets. In rat and mouse insulin-secreting cell lines (INS-1 and MIN6), CRFR1 agonists upregulated insulin receptor substrate 2 (IRS2) expression, increased AKT activation, counteracted the cytokine-mediated decrease in BAD phosphorylation, and inhibited apoptosis. The anti-apoptotic signaling was dependent on prolonged exposure to corticotropin-releasing factor family peptides and followed PKA-mediated IRS2 upregulation. This indicates that CRFR signaling counteracts proinflammatory cytokine-mediated apoptotic pathways through upregulation of survival signaling in β-cells. Interestingly, CRFR signaling also counteracted basal apoptosis in both cultured INS-1 cells and intact human islets.
Collapse
Affiliation(s)
- Lykke Blaabjerg
- Clayton Foundation Laboratories for Peptide BiologySalk Institute, 10100 North Torrey Pines Road, La Jolla, California 92037, USACellular and Metabolic Research SectionDepartment of Biomedical Sciences, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen N, Denmark Clayton Foundation Laboratories for Peptide BiologySalk Institute, 10100 North Torrey Pines Road, La Jolla, California 92037, USACellular and Metabolic Research SectionDepartment of Biomedical Sciences, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen N, Denmark
| | - Gitte L Christensen
- Clayton Foundation Laboratories for Peptide BiologySalk Institute, 10100 North Torrey Pines Road, La Jolla, California 92037, USACellular and Metabolic Research SectionDepartment of Biomedical Sciences, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen N, Denmark
| | - Masahito Matsumoto
- Clayton Foundation Laboratories for Peptide BiologySalk Institute, 10100 North Torrey Pines Road, La Jolla, California 92037, USACellular and Metabolic Research SectionDepartment of Biomedical Sciences, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen N, Denmark
| | - Talitha van der Meulen
- Clayton Foundation Laboratories for Peptide BiologySalk Institute, 10100 North Torrey Pines Road, La Jolla, California 92037, USACellular and Metabolic Research SectionDepartment of Biomedical Sciences, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen N, Denmark
| | - Mark O Huising
- Clayton Foundation Laboratories for Peptide BiologySalk Institute, 10100 North Torrey Pines Road, La Jolla, California 92037, USACellular and Metabolic Research SectionDepartment of Biomedical Sciences, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen N, Denmark
| | - Nils Billestrup
- Clayton Foundation Laboratories for Peptide BiologySalk Institute, 10100 North Torrey Pines Road, La Jolla, California 92037, USACellular and Metabolic Research SectionDepartment of Biomedical Sciences, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen N, Denmark
| | - Wylie W Vale
- Clayton Foundation Laboratories for Peptide BiologySalk Institute, 10100 North Torrey Pines Road, La Jolla, California 92037, USACellular and Metabolic Research SectionDepartment of Biomedical Sciences, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen N, Denmark
| |
Collapse
|
90
|
Banerjee M, Robbins D, Chen T. Targeting xenobiotic receptors PXR and CAR in human diseases. Drug Discov Today 2014; 20:618-28. [PMID: 25463033 DOI: 10.1016/j.drudis.2014.11.011] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 10/28/2014] [Accepted: 11/17/2014] [Indexed: 12/20/2022]
Abstract
Nuclear receptors such as the pregnane X receptor (PXR) and constitutive androstane receptor (CAR) are xenobiotic receptors regulating not only drug metabolism and disposition but also various human diseases such as cancer, diabetes, inflammatory disease, metabolic disease and liver diseases, suggesting that PXR and CAR are promising targets for drug discovery. Consequently, there is an urgent need to discover and develop small molecules that target these PXR- and/or CAR-mediated human-disease-related pathways for relevant therapeutic applications. This review proposes approaches to target PXR and CAR, either individually or simultaneously, in the context of various human diseases, taking into consideration the structural differences between PXR and CAR.
Collapse
Affiliation(s)
- Monimoy Banerjee
- Department of Chemical Biology and Therapeutics, St Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Delira Robbins
- Department of Chemical Biology and Therapeutics, St Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Taosheng Chen
- Department of Chemical Biology and Therapeutics, St Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA.
| |
Collapse
|
91
|
Quiñones M, Al-Massadi O, Fernø J, Nogueiras R. Cross-talk between SIRT1 and endocrine factors: effects on energy homeostasis. Mol Cell Endocrinol 2014; 397:42-50. [PMID: 25109279 DOI: 10.1016/j.mce.2014.08.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2014] [Revised: 08/01/2014] [Accepted: 08/01/2014] [Indexed: 12/14/2022]
Abstract
The mammalian sirtuins (SIRT1-7) are a family of highly conserved nicotine adenine dinucleotide (NAD(+))-dependent deacetylases that act as cellular sensors to detect energy availability. SIRT1 is a multifaceted protein that is involved in a wide variety of cellular processes. SIRT1 is activated in response to caloric restriction, acting on multiple targets in a wide range of tissues. SIRT1 regulates the role of multiple hormones implicated in energy balance, including glucose and lipid metabolism. Here, we review the relevant role of SIRT1 as a mediator of endocrine function of several hormones to modulate energy balance. In addition, we analyze the potential of targeting SIRT1 for the treatment of obesity and type 2 diabetes mellitus.
Collapse
Affiliation(s)
- Mar Quiñones
- Department of Physiology, School of Medicine-CIMUS, Instituto de Investigacion Sanitaria (IDIS), CIBER Fisiopatologia de la Obesidad y Nutricion (CIBERobn), University of Santiago de Compostela, San Francisco s/n, Santiago de Compostela (A Coruña), 15782, and Avda. Barcelona 3, 15782, Santiago de Compostela, Spain.
| | - Omar Al-Massadi
- Department of Physiology, School of Medicine-CIMUS, Instituto de Investigacion Sanitaria (IDIS), CIBER Fisiopatologia de la Obesidad y Nutricion (CIBERobn), University of Santiago de Compostela, San Francisco s/n, Santiago de Compostela (A Coruña), 15782, and Avda. Barcelona 3, 15782, Santiago de Compostela, Spain
| | - Johan Fernø
- Department of Clinical Science, K. G. Jebsen Center for Diabetes Research, University of Bergen, Bergen, Norway
| | - Ruben Nogueiras
- Department of Physiology, School of Medicine-CIMUS, Instituto de Investigacion Sanitaria (IDIS), CIBER Fisiopatologia de la Obesidad y Nutricion (CIBERobn), University of Santiago de Compostela, San Francisco s/n, Santiago de Compostela (A Coruña), 15782, and Avda. Barcelona 3, 15782, Santiago de Compostela, Spain.
| |
Collapse
|
92
|
Traboulsi H, Davoli S, Catez P, Egly JM, Compe E. Dynamic partnership between TFIIH, PGC-1α and SIRT1 is impaired in trichothiodystrophy. PLoS Genet 2014; 10:e1004732. [PMID: 25340339 PMCID: PMC4207666 DOI: 10.1371/journal.pgen.1004732] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Accepted: 09/04/2014] [Indexed: 12/05/2022] Open
Abstract
The expression of protein-coding genes requires the selective role of many transcription factors, whose coordinated actions remain poorly understood. To further grasp the molecular mechanisms that govern transcription, we focused our attention on the general transcription factor TFIIH, which gives rise, once mutated, to Trichothiodystrophy (TTD), a rare autosomal premature-ageing disease causing inter alia, metabolic dysfunctions. Since this syndrome could be connected to transcriptional defects, we investigated the ability of a TTD mouse model to cope with food deprivation, knowing that energy homeostasis during fasting involves an accurate regulation of the gluconeogenic genes in the liver. Abnormal amounts of gluconeogenic enzymes were thus observed in TTD hepatic parenchyma, which was related to the dysregulation of the corresponding genes. Strikingly, such gene expression defects resulted from the inability of PGC1-α to fulfill its role of coactivator. Indeed, extensive molecular analyses unveiled that wild-type TFIIH cooperated in an ATP-dependent manner with PGC1-α as well as with the deacetylase SIRT1, thereby contributing to the PGC1-α deacetylation by SIRT1. Such dynamic partnership was, however, impaired when TFIIH was mutated, having as a consequence the disruption of PGC1-α recruitment to the promoter of target genes. Therefore, besides a better understanding of the etiology of TFIIH-related disease, our results shed light on the synergistic relationship that exist between different types of transcription factors, which is necessary to properly regulate the expression of protein coding genes. In eukaryotes, the expression of genes encoding proteins requires the action of hundreds of factors, together with the RNA polymerase II. While these factors are timely and selectively required for the expression of a given gene, little is known about their partnership upon gene expression. Our results reveal a cooperation between different types of transcription factors, namely the general transcription factor TFIIH, the cofactor PGC-1α and the deacetylase SIRT1. Such partnership is however impaired when TFIIH is mutated, as observed in Trichothiodystrophy patients that develop premature ageing. These results thus shed light on the coordinated action of factors during transcription and allow us to better understand molecular deficiencies observed in many human diseases.
Collapse
Affiliation(s)
- Hussein Traboulsi
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, Strasbourg, France
| | - Serena Davoli
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, Strasbourg, France
| | - Philippe Catez
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, Strasbourg, France
| | - Jean-Marc Egly
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, Strasbourg, France
- * E-mail: (JME); (EC)
| | - Emmanuel Compe
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, Strasbourg, France
- * E-mail: (JME); (EC)
| |
Collapse
|
93
|
Hamann I, Petroll K, Grimm L, Hartwig A, Klotz LO. Insulin-like modulation of Akt/FoxO signaling by copper ions is independent of insulin receptor. Arch Biochem Biophys 2014; 558:42-50. [PMID: 24933099 DOI: 10.1016/j.abb.2014.06.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 05/19/2014] [Accepted: 06/04/2014] [Indexed: 11/26/2022]
Abstract
Copper ions are known to induce insulin-like effects in various cell lines, stimulating the phosphoinositide 3'-kinase (PI3K)/Akt signaling cascade and leading to the phosphorylation of downstream targets, including FoxO transcription factors. The aim of this work was to study the role of insulin- and IGF1-receptors (IR and IGF1R) in insulin-like signaling induced by copper in HepG2 human hepatoma cells. Cells were exposed to Cu(II) at various concentrations for up to 60 min. While Akt and FoxO1a/FoxO3a were strongly phosphorylated in copper- and insulin-treated cells at all time points studied, only faint tyrosine phosphorylation of IR/IGF1R was detected in cells exposed to Cu(II) by either immunoprecipitation/immunoblot or by immunoblotting using phospho-specific antibodies, whereas insulin triggered strong phosphorylation at these sites. Pharmacological inhibition of IR/IGF1R modestly attenuated Cu-induced Akt and FoxO phosphorylation, whereas no attenuation of Cu-induced Akt activation was achieved by siRNA-mediated IR depletion. Cu(II)-induced FoxO1a nuclear exclusion was only slightly impaired by pharmacological inhibition of IR/IGF1R, whereas insulin-induced effects were blunted. In contrast, genistein, a broad-spectrum tyrosine kinase inhibitor, at concentrations not affecting IR/IGF1R, attenuated Cu(II)-induced Akt phosphorylation, pointing to the requirement of tyrosine kinases other than IR/IGF1R for Cu(II)-induced signaling.
Collapse
Affiliation(s)
- Ingrit Hamann
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada
| | - Kerstin Petroll
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada; Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Larson Grimm
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada
| | | | - Lars-Oliver Klotz
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada; Institute of Nutrition, Department of Nutrigenomics, Friedrich-Schiller Universität Jena, Germany.
| |
Collapse
|
94
|
Sanchez AMJ, Candau RB, Bernardi H. FoxO transcription factors: their roles in the maintenance of skeletal muscle homeostasis. Cell Mol Life Sci 2014; 71:1657-71. [PMID: 24232446 PMCID: PMC11113648 DOI: 10.1007/s00018-013-1513-z] [Citation(s) in RCA: 211] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 10/27/2013] [Accepted: 10/30/2013] [Indexed: 12/23/2022]
Abstract
Forkhead box class O family member proteins (FoxOs) are highly conserved transcription factors with important roles in cellular homeostasis. The four FoxO members in humans, FoxO1, FoxO3, FoxO4, and FoxO6, are all expressed in skeletal muscle, but the first three members are the most studied in muscle. In this review, we detail the multiple modes of FoxO regulation and discuss the central role of these proteins in the control of skeletal muscle plasticity. FoxO1 and FoxO3 are key factors of muscle energy homeostasis through the control of glycolytic and lipolytic flux, and mitochondrial metabolism. They are also key regulators of protein breakdown, as they modulate the activity of several actors in the ubiquitin–proteasome and autophagy–lysosomal proteolytic pathways, including mitochondrial autophagy, also called mitophagy. FoxO proteins have also been implicated in the regulation of the cell cycle, apoptosis, and muscle regeneration. Depending of their activation level, FoxO proteins can exhibit ambivalent functions. For example, a basal level of FoxO factors is necessary for cellular homeostasis and these proteins are required for adaptation to exercise. However, exacerbated activation may occur in the course of several diseases, resulting in metabolic disorders and atrophy. A better understanding of the precise functions of these transcriptions factors should thus lead to the development of new therapeutic approaches to prevent or limit the muscle wasting that prevails in numerous pathological states, such as immobilization, denervated conditions, neuromuscular disease, aging, AIDS, cancer, and diabetes.
Collapse
Affiliation(s)
- Anthony M. J. Sanchez
- INRA, UMR866 Dynamique Musculaire Et Métabolisme, Université Montpellier 1, 2 Place Viala, 34060 Montpellier, France
- Faculté des Sciences du Sport, Université Montpellier 1, 700 avenue du Pic Saint Loup, 34090 Montpellier, France
| | - Robin B. Candau
- INRA, UMR866 Dynamique Musculaire Et Métabolisme, Université Montpellier 1, 2 Place Viala, 34060 Montpellier, France
- Faculté des Sciences du Sport, Université Montpellier 1, 700 avenue du Pic Saint Loup, 34090 Montpellier, France
| | - Henri Bernardi
- INRA, UMR866 Dynamique Musculaire Et Métabolisme, Université Montpellier 1, 2 Place Viala, 34060 Montpellier, France
| |
Collapse
|
95
|
Kazantseva YA, Yarushkin AA, Pustylnyak VO. CAR-mediated repression of Foxo1 transcriptional activity regulates the cell cycle inhibitor p21 in mouse livers. Toxicology 2014; 321:73-9. [PMID: 24769335 DOI: 10.1016/j.tox.2014.04.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 04/14/2014] [Accepted: 04/15/2014] [Indexed: 01/29/2023]
Abstract
1,4-Bis[2-(3,5-dichloropyridyloxy)]benzene (TCPOBOP), an agonist of constitutive androstane receptor (CAR), is a well-known strong primary chemical mitogen for the mouse liver. Despite extensive investigation of the role of CAR in the regulation of cell proliferation, our knowledge of the intricate mediating mechanism is incomplete. In this study, we demonstrated that long-term CAR activation by TCPOBOP increased liver-to-body weight ratio and decreased tumour suppressor Foxo1 expression and transcriptional activity, which were correlated with reduced expression of genes regulated by Foxo1, including the cell-cycle inhibitor Cdkn1a(p21), and upregulation of the cell-cycle regulator Cyclin D1. Moreover, we demonstrated the negative regulatory effect of TCPOBOP-activated CAR on the association of Foxo1 with the target Foxo1 itself and Cdkn1a(p21) promoters. Thus, we identified CAR-mediated repression of cell cycle inhibitor p21, as mediated by repression of FOXO1 expression and transcriptional activity. CAR-FOXO1 cross-talk may provide new opportunities for understanding liver diseases and developing more effective therapeutic approaches to better drug treatments.
Collapse
Affiliation(s)
- Yuliya A Kazantseva
- Institute of Molecular Biology and Biophysics SB RAMS, Timakova str. 2, Novosibirsk 630117, Russia
| | - Andrei A Yarushkin
- Institute of Molecular Biology and Biophysics SB RAMS, Timakova str. 2, Novosibirsk 630117, Russia
| | - Vladimir O Pustylnyak
- Institute of Molecular Biology and Biophysics SB RAMS, Timakova str. 2, Novosibirsk 630117, Russia; Novosibirsk State University, Pirogova str. 2, Novosibirsk 630090, Russia.
| |
Collapse
|
96
|
Guo S. Insulin signaling, resistance, and the metabolic syndrome: insights from mouse models into disease mechanisms. J Endocrinol 2014; 220:T1-T23. [PMID: 24281010 PMCID: PMC4087161 DOI: 10.1530/joe-13-0327] [Citation(s) in RCA: 329] [Impact Index Per Article: 32.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Insulin resistance is a major underlying mechanism responsible for the 'metabolic syndrome', which is also known as insulin resistance syndrome. The incidence of the metabolic syndrome is increasing at an alarming rate, becoming a major public and clinical problem worldwide. The metabolic syndrome is represented by a group of interrelated disorders, including obesity, hyperglycemia, hyperlipidemia, and hypertension. It is also a significant risk factor for cardiovascular disease and increased morbidity and mortality. Animal studies have demonstrated that insulin and its signaling cascade normally control cell growth, metabolism, and survival through the activation of MAPKs and activation of phosphatidylinositide-3-kinase (PI3K), in which the activation of PI3K associated with insulin receptor substrate 1 (IRS1) and IRS2 and subsequent Akt→Foxo1 phosphorylation cascade has a central role in the control of nutrient homeostasis and organ survival. The inactivation of Akt and activation of Foxo1, through the suppression IRS1 and IRS2 in different organs following hyperinsulinemia, metabolic inflammation, and overnutrition, may act as the underlying mechanisms for the metabolic syndrome in humans. Targeting the IRS→Akt→Foxo1 signaling cascade will probably provide a strategy for therapeutic intervention in the treatment of type 2 diabetes and its complications. This review discusses the basis of insulin signaling, insulin resistance in different mouse models, and how a deficiency of insulin signaling components in different organs contributes to the features of the metabolic syndrome. Emphasis is placed on the role of IRS1, IRS2, and associated signaling pathways that are coupled to Akt and the forkhead/winged helix transcription factor Foxo1.
Collapse
Affiliation(s)
- Shaodong Guo
- Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, Scott & White, Central Texas Veterans Health Care System, 1901 South 1st Street, Bldg. 205, Temple, Texas 76504, USA
| |
Collapse
|
97
|
Zhao Y, Yu Y, Tian X, Yang X, Li X, Jiang F, Chen Y, Shi M. Association study to evaluate FoxO1 and FoxO3 gene in CHD in Han Chinese. PLoS One 2014; 9:e86252. [PMID: 24489705 PMCID: PMC3904908 DOI: 10.1371/journal.pone.0086252] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Accepted: 12/10/2013] [Indexed: 12/22/2022] Open
Abstract
Background Coronary heart disease (CHD) is one of the leading causes of mortality and morbidity in China. Genetic factors that predispose individuals to CHD are unclear. In the present study, we aimed to determine whether the variation of FoxOs, a novel genetic factor associated with longevity, was associated with CHD in Han Chinese populations. Methods 1271 CHD patients and 1287 age-and sex-matched controls from Beijing and Harbin were included. We selected four tagging single nucleotide polymorphisms (SNPs) of FoxO1 (rs2755209, rs2721072, rs4325427 and rs17592371) and two tagging SNPs of FoxO3 (rs768023 and rs1268165). And the genotypes of these SNPs were determined in both CHD patients and non-CHD controls. Results For population from Beijing, four SNPs of FoxO1 and two SNPs of FoxO3 were found not to be associated with CHD (p>0.05). And this was validated in the other population from Harbin (p>0.05). After combining the two geographically isolated case-control populations, the results showed that the six SNPs did not necessarily predispose to CHD in Han Chinese(p>0.05). In stratified analysis according to gender, the history of smoking, hypertension, diabetes mellitus, hyperlipidemia and the metabolic syndrome, we further explored that neither the variants of FoxO1 nor the variants of FoxO3 might be associated with CHD (p>0.05). Conclusion The variants of FoxO1 and FoxO3 may not increase the prevalence of CHD in Han Chinese population.
Collapse
Affiliation(s)
- Ying Zhao
- Department of Geriatrics, Jinan Military General Hospital, Jinan, China
| | - Yanbo Yu
- Department of Gastroenterology, Qilu Hospital of Shandong University, Jinan, China
| | - Xiaoli Tian
- Department of Human Population Genetics, Institute of Molecular Medicine, Peking University, Beijing, China
| | - Xi Yang
- Department of Human Population Genetics, Institute of Molecular Medicine, Peking University, Beijing, China
| | - Xueqi Li
- Department of Cardiology, the Fourth Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Feng Jiang
- Department of Cardiology, the Fourth Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Yundai Chen
- Department of Cardiology, Chinese PLA General Hospital, Beijing, China
- * E-mail: (YC); (MS)
| | - Maowei Shi
- Department of Geriatrics, Jinan Military General Hospital, Jinan, China
- * E-mail: (YC); (MS)
| |
Collapse
|
98
|
Souza Pauli LS, Ropelle ECC, de Souza CT, Cintra DE, da Silva ASR, de Almeida Rodrigues B, de Moura LP, Marinho R, de Oliveira V, Katashima CK, Pauli JR, Ropelle ER. Exercise training decreases mitogen-activated protein kinase phosphatase-3 expression and suppresses hepatic gluconeogenesis in obese mice. J Physiol 2014; 592:1325-40. [PMID: 24396063 DOI: 10.1113/jphysiol.2013.264002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Insulin plays an important role in the control of hepatic glucose production. Insulin resistant states are commonly associated with excessive hepatic glucose production, which contributes to both fasting hyperglycaemia and exaggerated postprandial hyperglycaemia. In this regard, increased activity of phosphatases may contribute to the dysregulation of gluconeogenesis. Mitogen-activated protein kinase phosphatase-3 (MKP-3) is a key protein involved in the control of gluconeogenesis. MKP-3-mediated dephosphorylation activates FoxO1 (a member of the forkhead family of transcription factors) and subsequently promotes its nuclear translocation and binding to the promoters of gluconeogenic genes such as phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase). In this study, we investigated the effects of exercise training on the expression of MKP-3 and its interaction with FoxO1 in the livers of obese animals. We found that exercised obese mice had a lower expression of MKP-3 and FoxO1/MKP-3 association in the liver. Further, the exercise training decreased FoxO1 phosphorylation and protein levels of Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) and gluconeogenic enzymes (PEPCK and G6Pase). These molecular results were accompanied by physiological changes, including increased insulin sensitivity and reduced hyperglycaemia, which were not caused by reductions in total body mass. Similar results were also observed with oligonucleotide antisense (ASO) treatment. However, our results showed that only exercise training could reduce an obesity-induced increase in HNF-4α protein levels while ASO treatment alone had no effect. These findings could explain, at least in part, why additive effects of exercise training treatment and ASO treatment were not observed. Finally, the suppressive effects of exercise training on MKP-3 protein levels appear to be related, at least in part, to the reduced phosphorylation of Extracellular signal-regulated kinases (ERK) in the livers of obese mice.
Collapse
|
99
|
Steinbrenner H. Interference of selenium and selenoproteins with the insulin-regulated carbohydrate and lipid metabolism. Free Radic Biol Med 2013; 65:1538-1547. [PMID: 23872396 DOI: 10.1016/j.freeradbiomed.2013.07.016] [Citation(s) in RCA: 112] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Revised: 07/08/2013] [Accepted: 07/09/2013] [Indexed: 01/26/2023]
Abstract
An assumed link between supranutritional intake of the micronutrient selenium (Se) and type 2 diabetes mellitus is discussed controversially. Se concentrations in the habitual diet and in dietary supplements are probably not sufficient to induce overt diabetes in healthy individuals. On the other hand, high plasma Se and selenoprotein P (Sepp1) levels have been found to be associated with biomarkers of an impaired carbohydrate and lipid homeostasis in humans. Moreover, abundant expression of antioxidant selenoproteins due to dietary Se oversupply resulted in hyperinsulinemia and decreased insulin sensitivity in animal models. This review discusses findings from animal and cell culture studies in search of molecular mechanisms underlying an interference of Se and selenproteins such as the Se transport and supply protein Sepp1 and the hydrogen peroxide-reducing selenoenzyme glutathione peroxidase 1 (GPx1) with insulin-controlled metabolic pathways. A probable rationale derives from the positive and negative regulation of both glucose-induced insulin secretion and insulin-induced signaling by hydrogen peroxide. Se status and GPx1 expression have been reported to affect the activity of insulin-antagonistic phosphatases that are regulated by hydrogen peroxide-mediated reversible oxidation of catalytic cysteine residues. GPx1 and/or Sepp1 inhibited phosphorylation (activation) of key mediators in energy metabolism such as protein kinase B (Akt) and AMP-activated protein kinase (AMPK) in liver and/or skeletal muscle. Conversely, a dys-regulated carbohydrate metabolism in diabetes might affect plasma Se and Sepp1 levels, as the hepatic biosynthesis of Sepp1 is suppressed by insulin and stimulated under hyperglycemic conditions.
Collapse
Affiliation(s)
- Holger Steinbrenner
- Institute for Biochemistry and Molecular Biology I, Heinrich-Heine-Universität, Düsseldorf, Germany.
| |
Collapse
|
100
|
Jiang Y, Zou L, Lu WQ, Zhang Y, Shen AG. Foxo3a expression is a prognostic marker in breast cancer. PLoS One 2013; 8:e70746. [PMID: 23967095 PMCID: PMC3742799 DOI: 10.1371/journal.pone.0070746] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Accepted: 06/24/2013] [Indexed: 01/14/2023] Open
Abstract
The forkhead box transcription factor Foxo3a has been implicated to play a critical role in various cancers by suppressing tumor growth. Recent studies have identified Foxo3a as a key regulator of Estrogen Receptor-α (ERα). In the present study, we examined the expression of Foxo3a, and investigated its clinical significance and correlation with ER and prognostic role in patients with breast cancer. Immunohistochemical analysis was performed on tumors from 70 breast cancer patients. Interpretable Foxo3a expression was analyzed along with major clinicopathologic variables, and a comparison was made with corresponding 5-year clinical follow-up data. Foxo3a protein expression correlated with ER positivity (P<0.001), histologic grade (1, 2) (P = 0.002), axillary lymph node negativity (P<0.001) and TNM stage (1, 2) (P<0.001). Moreover, the Kaplan-Meier survival curves of the study population showed that a high expression level of Foxo3a was significantly correlated with long-term survival (P<0.0001). In a multivariate analysis, Foxo3a expression was identified as a favorable independent prognostic factor in overall survival (P = 0.038). In conclusion, our results indicated that Foxo3a expression is a favorable prognostic marker in breast cancer. In addition, Foxo3a staining could potentially be used in patient stratification in conjunction with other prognostic markers.
Collapse
Affiliation(s)
- Ying Jiang
- Department of General Surgery, Zhongshan Hospital, Fudan University, Shanghai, P.R. China
- Department of General Surgery, Affiliated Hospital of Nantong University, Nantong, Jiangsu, P.R. China
- * E-mail: (YJ); (WQL)
| | - Lin Zou
- Department of Pathology, The First People's Hospital of Yancheng affiliated with Nantong University, Yancheng, Jiangsu, P.R. China
| | - Wei-Qi Lu
- Department of General Surgery, Zhongshan Hospital, Fudan University, Shanghai, P.R. China
- * E-mail: (YJ); (WQL)
| | - Yong Zhang
- Department of General Surgery, Zhongshan Hospital, Fudan University, Shanghai, P.R. China
| | - Ai-Guo Shen
- Department of Pathology, Nantong University, Nantong, P.R. China
| |
Collapse
|